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WO2021193723A1 - Interlayer sheet, interlayer sheet with release liner, and optical laminate - Google Patents

Interlayer sheet, interlayer sheet with release liner, and optical laminate Download PDF

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Publication number
WO2021193723A1
WO2021193723A1 PCT/JP2021/012260 JP2021012260W WO2021193723A1 WO 2021193723 A1 WO2021193723 A1 WO 2021193723A1 JP 2021012260 W JP2021012260 W JP 2021012260W WO 2021193723 A1 WO2021193723 A1 WO 2021193723A1
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WO
WIPO (PCT)
Prior art keywords
weight
monomer
less
sensitive adhesive
pressure
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Ceased
Application number
PCT/JP2021/012260
Other languages
French (fr)
Japanese (ja)
Inventor
普史 形見
賢一 片岡
智哉 西野
祐輔 山本
慎太郎 野依
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Nitto Denko Corp
Original Assignee
Nitto Denko Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Nitto Denko Corp filed Critical Nitto Denko Corp
Priority to CN202180024127.5A priority Critical patent/CN115362233B/en
Priority to KR1020227036305A priority patent/KR20220156055A/en
Publication of WO2021193723A1 publication Critical patent/WO2021193723A1/en
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

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    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
    • C09J7/00—Adhesives in the form of films or foils
    • C09J7/30—Adhesives in the form of films or foils characterised by the adhesive composition
    • C09J7/38—Pressure-sensitive adhesives [PSA]
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B27/00—Layered products comprising a layer of synthetic resin
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B27/00—Layered products comprising a layer of synthetic resin
    • B32B27/06—Layered products comprising a layer of synthetic resin as the main or only constituent of a layer, which is next to another layer of the same or of a different material
    • B32B27/08—Layered products comprising a layer of synthetic resin as the main or only constituent of a layer, which is next to another layer of the same or of a different material of synthetic resin
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B7/00—Layered products characterised by the relation between layers; Layered products characterised by the relative orientation of features between layers, or by the relative values of a measurable parameter between layers, i.e. products comprising layers having different physical, chemical or physicochemical properties; Layered products characterised by the interconnection of layers
    • B32B7/02—Physical, chemical or physicochemical properties
    • B32B7/022—Mechanical properties
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B7/00—Layered products characterised by the relation between layers; Layered products characterised by the relative orientation of features between layers, or by the relative values of a measurable parameter between layers, i.e. products comprising layers having different physical, chemical or physicochemical properties; Layered products characterised by the interconnection of layers
    • B32B7/02—Physical, chemical or physicochemical properties
    • B32B7/023—Optical properties
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B7/00—Layered products characterised by the relation between layers; Layered products characterised by the relative orientation of features between layers, or by the relative values of a measurable parameter between layers, i.e. products comprising layers having different physical, chemical or physicochemical properties; Layered products characterised by the interconnection of layers
    • B32B7/04—Interconnection of layers
    • B32B7/12—Interconnection of layers using interposed adhesives or interposed materials with bonding properties
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
    • C09J11/00—Features of adhesives not provided for in group C09J9/00, e.g. additives
    • C09J11/02—Non-macromolecular additives
    • C09J11/06—Non-macromolecular additives organic
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
    • C09J133/00—Adhesives based on homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by only one carboxyl radical, or of salts, anhydrides, esters, amides, imides, or nitriles thereof; Adhesives based on derivatives of such polymers
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
    • C09J201/00—Adhesives based on unspecified macromolecular compounds
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
    • C09J7/00—Adhesives in the form of films or foils
    • C09J7/10—Adhesives in the form of films or foils without carriers
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B5/00—Optical elements other than lenses
    • G02B5/30—Polarising elements
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B2367/00—Polyesters, e.g. PET, i.e. polyethylene terephthalate
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
    • C09J2301/00—Additional features of adhesives in the form of films or foils
    • C09J2301/30—Additional features of adhesives in the form of films or foils characterized by the chemical, physicochemical or physical properties of the adhesive or the carrier
    • C09J2301/312—Additional features of adhesives in the form of films or foils characterized by the chemical, physicochemical or physical properties of the adhesive or the carrier parameters being the characterizing feature

Definitions

  • the present invention has been created in view of the above circumstances, and provides an interlayer sheet that exhibits flexibility suitable for adhering to and following adjacent members, and has a high refractive index and high transparency.
  • Another object of the present invention for the purpose of the present invention is to provide an interlayer sheet with a release liner containing the above-mentioned interlayer sheet.
  • Another related object is to provide an optical laminate that includes the interlayer sheet as a component.
  • Interlayer sheet further comprises a viscoelastic layer V 2 which is laminated on the viscoelastic layer V 1.
  • the storage elastic modulus at 25 ° C. of the viscoelastic layer V 2 G 'V2 (hereinafter, "storage modulus G' may be referred to as V2 (25)".) Is the viscoelastic layer V 1 lower than the storage modulus G 'V1 at 25 ° C..
  • Such configuration interlayer sheet is due to the contribution of the viscoelastic layer V 2, it can be excellent in more flexible.
  • the refractive index n 2 of the viscoelastic layer V 2 is lower than the refractive index n 1 of the viscoelastic layer V 1. According to the interlayer sheet having such a configuration, by utilizing the refractive index difference of the viscoelastic layer V 1, V 2, it is possible to control the behavior of light transmitted through the interlayer sheet.
  • an interlayer sheet with a release liner including any of the interlayer sheets disclosed herein and a release liner covering at least one surface of the interlayer sheet.
  • the interlayer sheet disclosed herein is manufactured, stored, distributed, processed, etc. in the form of an interlayer sheet with a release liner whose at least one surface is protected by a release liner in this way, and before being laminated with an adjacent member. It can be preferably used in the mode of peeling off the release liner.
  • an optical laminate including any of the interlayer sheets disclosed herein and a resin film laminated on the interlayer sheet is provided.
  • the advantages of the interlayer sheet disclosed herein having high refractive index, high transparency and flexibility can be preferably exhibited.
  • Interlayer sheet disclosed herein, one or both surfaces an adhesive layer (for example, pressure-sensitive adhesive layer having a single layer structure made of viscoelastic layer V 1 of the non-releasable substrate (support substrate), or viscoelastic It may be in the form of an adhesive sheet with a base material having a laminated structure (adhesive layer having a laminated structure in which two or more adhesive layers including a layer V 1 and a viscoelastic layer V 2 are directly in contact with each other).
  • an adhesive layer for example, pressure-sensitive adhesive layer having a single layer structure made of viscoelastic layer V 1 of the non-releasable substrate (support substrate), or viscoelastic It may be in the form of an adhesive sheet with a base material having a laminated structure (adhesive layer having a laminated structure in which two or more adhesive layers including a layer V 1 and a viscoelastic layer V 2 are directly in contact with each other).
  • Adhesive layer 10 may be a single layer structure made of viscoelastic layer V 1 as shown in FIG. 1, 2 or more sub-sensitive adhesive layer having a different composition (e.g., viscoelastic layer constituting the adhesive surface 10A A laminated structure in which V 1 and two sub-adhesive layers of a viscoelastic layer V 2 arranged on the support base material 20 side are directly in contact with each other (that is, without being separated by a layer of a non-adhesive material). It may be.
  • the interlayer sheet disclosed herein may be in the form of a base material-less double-sided pressure-sensitive adhesive sheet composed of a pressure-sensitive adhesive layer.
  • the base material-less double-sided adhesive sheet 2 has a first surface (first adhesive surface) 10A and a second surface (second adhesive surface) 10B of the adhesive layer 10 before use.
  • At least the adhesive layer side may be a form protected by a release liner 31 or 32 having a releaseable surface (release surface).
  • the back surface of the release liner 31 (the surface opposite to the adhesive side) is the release surface, and the adhesive surface is wound or laminated so that the adhesive surface 10B abuts on the back surface of the release liner 31.
  • 10A and 10B may be in a protected form.
  • the refractive index of the pressure-sensitive adhesive can be measured by the method described in Examples described later.
  • the refractive index of the pressure-sensitive adhesive can be adjusted, for example, by the composition of the pressure-sensitive adhesive (for example, the composition of the monomer components constituting the base polymer, additives that can be used if necessary, etc.).
  • the difference between the refractive index n 1 of the first adhesive surface of the interlayer sheet and the refractive index n 2 of the second adhesive surface, that is, n 1- n 2, is, for example, greater than 0.00. It may be 0.01 or more, preferably 0.02 or more, 0.03 or more, 0.05 or more, 0.10 or more, 0.15 or more, and 0. It may be 20 or more, or 0.25 or more. The magnitude relationship between n 1 and n 2 may be reversed. The upper limit of n 1 to n 2 is not particularly limited.
  • the lower limit of the storage elastic modulus G'V1 (50) is not particularly limited.
  • the storage modulus G 'V1 (50) may be for example 10kPa or more may be at least 15 kPa, may be more than 20 kPa, more 23kPa It may be.
  • the viscoelastic layer (adhesive layer) V 1 has the following conditions: (A) storage modulus G 'V1 (25) is 350kPa or less (preferably less than 200 kPa, for example 180kPa or less); and (b) a storage modulus G' V1 (50) is less than 60 kPa (preferably less than 50 kPa, More preferably less than 40 kPa, eg less than 38 kPa); It is preferable to satisfy at least one of the above.
  • the storage elastic moduli G'V1 (25) and G'V1 (50) can be obtained by dynamic viscoelasticity measurement, and G'V1 (50) / G'V1 (25) can be calculated from the results.
  • the dynamic viscoelasticity measurement can be performed by a conventional method using a commercially available dynamic viscoelasticity measuring device, and can be performed under the following measurement conditions using, for example, ARES manufactured by TA Instruments or an equivalent product thereof. can.
  • As the sample for measurement a sample prepared to have a thickness of about 1.5 mm by laminating the pressure-sensitive adhesive layer to be evaluated as necessary is used. [Measurement condition] Deformation mode: Torsion measurement frequency: 1Hz Temperature rise rate: 5 ° C / min Shape: Parallel plate 7.9 mm ⁇
  • Interlayer sheet disclosed herein comprises a PSA layer V 1 having a high refractive index of above and, and haze value of the interlayer sheet is 1.0% or less.
  • a highly transparent interlayer sheet can be used for applications requiring high light transmission (for example, optical applications) in a configuration having or not having a base material, and an adherend can be satisfactorily visually recognized through the interlayer sheet. It can be preferably applied to applications where performance is required.
  • the haze value of the interlayer sheet may be 0.9% or less, 0.8% or less, 0.5% or less, or 0.3% or less.
  • the lower limit of the haze value of the interlayer sheet is not particularly limited, and a smaller haze value is preferable from the viewpoint of improving transparency.
  • the haze value of the interlayer sheet may be, for example, 0.05% or more, or 0.1% or more, in consideration of the refractive index and the adhesive property. It may be 0.2% or more, 0.3% or more, or 0.4% or more.
  • These haze values for the interlayer sheet are also the haze values of the pressure-sensitive adhesive sheet when the technique disclosed herein is carried out in the form of a base material-less pressure-sensitive adhesive sheet (typically, a pressure-sensitive adhesive sheet composed of an adhesive layer). It may be preferably applied.
  • the interlayer sheet disclosed herein is in the form of a double-sided pressure-sensitive adhesive sheet with a base material having a first pressure-sensitive adhesive layer and a second pressure-sensitive adhesive layer, at least the first pressure-sensitive adhesive layer (preferably the pressure-sensitive adhesive layer V 1 ). It is preferable that the water absorption rate of the above is limited to a predetermined value or less. From the viewpoint of obtaining a higher effect, it is more preferable that the water absorption rates of the first and second pressure-sensitive adhesive layers are all limited to a predetermined value or less.
  • the gel fraction of the viscoelastic layer V 1 was, it is appropriately set depending on the intended use and mode of use, etc., but is not limited to a specific range.
  • the gel fraction is, for example, about 99% or less, and about 97% or less is appropriate. From the viewpoint of facilitating a good balance between high refractive index and adhesive properties, in some preferred embodiments, the gel fraction is about 95% or less, more preferably about 92% or less (for example, about 90% or less). Can be.
  • the fact that the gel fraction is not too high appropriately follows the unevenness that may exist on the surface of the adherend (for example, the uneven structure provided for the purpose of improving the light extraction efficiency in the light emitting device), and satisfactorily follows.
  • the gel fraction may be approximately 88% or less, approximately 75% or less, or approximately 65% or less. Further, the gel fraction is, for example, about 10% or more, and about 20% or more, from the viewpoint of imparting appropriate cohesiveness to the pressure-sensitive adhesive and appropriately expressing the adhesive characteristics, and is about 20% or more. It may be 30% or more. From the viewpoint of deformation resistance of the viscoelastic layer V 1 (prevention of air bubbles due to pressure squeeze out and foreign matter biting, etc.), the gel fraction is preferably about 30% or more, more preferably about 40% or more. , About 45% or more, about 50% or more, about 65% or more, or about 75% or more.
  • tan ⁇ tangent loss
  • the pressure-sensitive adhesive tan ⁇ has a measurement temperature range of -60 ° C while sandwiching a disk-shaped pressure-sensitive adhesive sample with a thickness of about 2 mm and a diameter of 7.9 mm between parallel plates and applying shear strain at a frequency of 1 Hz using a viscoelasticity tester.
  • Tpeak peak temperature of tan ⁇ of the pressure-sensitive adhesive
  • Tpeak of the viscoelastic layer V 1 was, is advantageously at 45 ° C. or less, or 35 ° C. or less, preferably from 30 ° C. or less (e.g., 25 ° C. or less) may be at 20 ° C. or less , 15 ° C. or lower. Adhesives with a lower Tpeak tend to provide good initial adhesiveness and adhesion in the room temperature range. On the other hand, it is preferable that the Tpeak of the pressure-sensitive adhesive is not too low from the viewpoint of imparting appropriate cohesiveness to the pressure-sensitive adhesive, and it tends to be suitable for both high refractive index and high refractive index.
  • the Tpeak of the pressure-sensitive adhesive may be, for example, ⁇ 40 ° C. or higher, ⁇ 30 ° C. or higher, ⁇ 20 ° C. or higher, ⁇ 5 ° C. or higher, 5 ° C. or higher. However, it may be 15 ° C. or higher, and further may be 25 ° C. or higher.
  • a pressure-sensitive adhesive having a relatively high Tpeak can be preferably used in an embodiment in which one or both of the pressure-sensitive adhesive and the adherend are heated to a temperature slightly higher than room temperature, if necessary, when the pressure-sensitive adhesive is attached to the adherend.
  • the viscoelastic layer V 1) it is preferable to apply the viscoelastic layer V 1), more preferably it is applied to both the pressure-sensitive adhesive layer constituting the pressure-sensitive adhesive layer and the second adhesive surface constituting the first adhesive surface.
  • the Tpeak of the pressure-sensitive adhesive layer forming the first adhesive surface and the Tpeak of the pressure-sensitive adhesive layer forming the second adhesive surface may be the same or different.
  • the type of the pressure-sensitive adhesive constituting the pressure-sensitive adhesive layer V 1 is not particularly limited.
  • the pressure-sensitive adhesive may be an acrylic polymer, a rubber-based polymer (for example, natural rubber, synthetic rubber, a mixture thereof, etc.), a polyester-based polymer, a urethane-based polymer, a polyether polymer, or a silicone-based polymer that can be used in the field of pressure-sensitive adhesives.
  • One or more of various rubber-like polymers such as polyamide polymers and fluoropolymers are included as adhesive polymers (hereinafter, also referred to as "base polymers" in the sense of structural polymers forming adhesives).
  • an interlayer sheet in which the pressure-sensitive adhesive layer V 1 is composed of an acrylic pressure-sensitive adhesive that is, an interlayer sheet having an acrylic pressure-sensitive adhesive layer will be mainly described, but the pressure-sensitive adhesive layer V 1 in the interlayer sheet disclosed herein will be mainly described. Is not intended to be limited to the acrylic pressure-sensitive adhesive layer.
  • acrylic means acrylic and methacrylic, respectively. Therefore, the concept of the acrylic monomer here may include both a monomer having an acryloyl group (acrylic monomer) and a monomer having a methacryloyl group (methacryl monomer).
  • a pressure-sensitive adhesive composition containing substantially all of the monomer components for example, 95% by weight or more, preferably 99% by weight or more
  • a pressure-sensitive adhesive composition containing substantially all of the monomer components in the form of a polymer is preferable from the viewpoint of easily forming an interlayer sheet with less distortion and warpage.
  • a compound containing at least one aromatic ring and at least one ethylenically unsaturated group in one molecule is used.
  • the monomer (m1) one of the compounds may be used alone or in combination of two or more.
  • the aromatic ring of the compound used as the monomer (m1) is, for example, a benzene ring (which may be a benzene ring forming a part of a biphenyl structure or a fluorene structure); a naphthalene ring, an inden ring, an azulene ring, an anthracene ring, and a phenanthrene.
  • the number of carbon atoms contained in the substituent is preferably 1 to 4, more preferably 1 to 3, and may be, for example, 1 or 2.
  • the aromatic ring has one or more substituents that do not have a substituent on the ring-constituting atom or are selected from the group consisting of an alkyl group, an alkoxy group and a halogen atom (eg, a bromine atom). It can be an aromatic ring having.
  • the fact that the aromatic ring of the monomer (m1) has a substituent on its ring-constituting atom means that the aromatic ring has a substituent other than the substituent having an ethylenically unsaturated group.
  • the aromatic ring and the ethylenically unsaturated group may be directly bonded or may be bonded via a linking group.
  • the linking group is, for example, an alkylene group, an oxyalkylene group, a poly (oxyalkylene) group, a phenyl group, an alkylphenyl group, an alkoxyphenyl group, and a structure in which one or more hydrogen atoms are substituted with hydroxyl groups in these groups. It can be a group containing one or more structures selected from the group (eg, hydroxyalkylene group), oxy group (—O— group), thiooxy group (—S— group), and the like.
  • the aromatic ring and the ethylenically unsaturated group are directly bonded or bonded via a linking group selected from the group consisting of alkylene groups, oxyalkylene groups and poly (oxyalkylene) groups.
  • An aromatic ring-containing monomer having a structure having a structure can be preferably adopted.
  • the number of carbon atoms in the alkylene group and the oxyalkylene group is preferably 1 to 4, more preferably 1 to 3, and may be, for example, 1 or 2.
  • the number of repetitions of the oxyalkylene unit in the poly (oxyalkylene) group can be, for example, 2 to 3.
  • the content of the monomer (m1) in the monomer component constituting the acrylic polymer (A) is not particularly limited, and the desired refractive index and adhesive properties (for example, peel strength, flexibility, etc.) and / or optical properties (for example, all) are not particularly limited. It can be set so as to realize a pressure-sensitive adhesive layer that has both light transmittance, haze value, etc.).
  • the content of the monomer (m1) in the monomer component may be, for example, 30% by weight or more, preferably 50% by weight or more, 60% by weight or more, or 70% by weight or more. good.
  • the content of the monomer (m1) may be 93% by weight or less, 90% by weight or less, 80% by weight or less, or 75% by weight or less. In some embodiments where more adhesive and / or optical properties are emphasized, the content of the monomer (m1) in the monomer component may be 70% by weight or less, 60% by weight or less, or 45% by weight or less. good.
  • a monomer having a structure in which two or more non-condensed aromatic rings are chemically bonded directly that is, without interposing other atoms
  • a monomer having a condensed aromatic ring structure a monomer having a fluorene structure, and a monomer having a dinaphthothiophene structure.
  • the monomer containing a plurality of aromatic rings may be used alone or in combination of two or more.
  • Examples of the monomer having a dibenzothiophene structure include (meth) acryloyl group-containing dibenzothiophene, vinyl group-containing dibenzothiophene, and the like.
  • a monomer having a dibenzothiophene structure is included in the concept of a monomer having a condensed aromatic ring structure because it has a structure in which a thiophene ring and two benzene rings are condensed. Neither the dinaphthothiophene structure nor the dibenzothiophene structure corresponds to a structure in which two or more uncondensed aromatic rings are directly chemically bonded.
  • the technique disclosed herein can also be carried out in an embodiment in which the content of the monomer containing a plurality of aromatic rings in the monomer (m1) is less than 5% by weight. It is not necessary to use a monomer containing a plurality of aromatic rings.
  • the content of the aromatic ring plurality-containing monomer in the above-mentioned monomer component may be 70% by weight or less, 50% by weight or less, and 25% by weight or less in consideration of adhesive properties and / or optical properties. However, it may be 15% by weight or less, or 5% by weight or less.
  • the technique disclosed herein can also be carried out in an embodiment in which the content of the monomer containing a plurality of aromatic rings in the above-mentioned monomer component is less than 3% by weight.
  • the high refractive index monomer may be used alone or in combination of two or more.
  • the refractive index of the monomer is measured using an Abbe refractive index meter under the conditions of a measurement wavelength of 589 nm and a measurement temperature of 25 ° C.
  • As the Abbe refractive index meter a model "DR-M4" manufactured by ATAGO or an equivalent product thereof can be used. If the manufacturer or the like provides a nominal value of the refractive index at 25 ° C., the nominal value can be adopted.
  • the content of the high refractive index monomer in the monomer component constituting the acrylic polymer is not particularly limited, and the desired refractive index and adhesive properties (for example, peel strength, flexibility, etc.) and / or optical properties (for example, total light transmittance) are not particularly limited. , Haze value, etc.) can be set so as to realize a pressure-sensitive adhesive layer.
  • the content of the high refractive index monomer in the monomer component may be, for example, 3% by weight or more, 10% by weight or more, or 25% by weight or more.
  • the content of the high refractive index monomer in the above-mentioned monomer component may be, for example, more than 35% by weight, and more than 50% by weight. It may be more than 70% by weight, 75% by weight or more, 85% by weight or more, 90% by weight or more, or 95% by weight or more.
  • the content of the high refractive index monomer in the above-mentioned monomer component can be 100% by weight, but it is advantageous to make it less than 100% by weight from the viewpoint of achieving a good balance between the high refractive index and the adhesive property and / or the optical property.
  • the Tg of the monomer L may be, for example, ⁇ 70 ° C. or higher, ⁇ 55 ° C. or higher, or ⁇ 45 ° C. or higher.
  • the monomer L one type can be used alone or two or more types can be used in combination.
  • the content of the monomer L in the monomer (m1) may be less than 100% by weight from the viewpoint of achieving both flexibility suitable as a pressure-sensitive adhesive and high refractive index in a well-balanced manner. , 98% by weight or less, 90% by weight or less, 80% by weight or less, 70% by weight or less, 50% by weight or less, 25% by weight or less, or 10% by weight or less.
  • the technique disclosed herein can also be carried out in an embodiment in which the content of the monomer L in the monomer (m1) is less than 5% by weight. It is not necessary to use the monomer L.
  • the glass transition temperature Tg m1 based on the composition of the monomer (m1) is a Tg obtained by the Fox formula described later based on the composition of only the monomer (m1) among the monomer components constituting the acrylic polymer.
  • the glass transition temperature Tg m1 is a homopolymer of each aromatic ring-containing monomer used as the monomer (m1) by applying the Fox formula described later for only the monomer (m1) among the monomer components constituting the acrylic polymer. It can be calculated from the glass transition temperature and the weight fraction of each aromatic ring-containing monomer in the total amount of the monomers (m1).
  • the Tg of the homopolymer of the monomer and the glass transition temperature Tg m1 are the same.
  • the monomer L and the monomer H in combination, for example, in a configuration in which the content of the aromatic ring-containing monomer (m1) in the monomer component is relatively large, the high refractive index and flexibility of the pressure-sensitive adhesive are compatible at a higher level. Can be made to.
  • the usage amount ratio of the monomer L and the monomer H can be set so as to preferably exhibit such an effect, and is not particularly limited. For example, it is preferable to set the usage amount ratio of the monomer L and the monomer H so as to satisfy any of the above-mentioned glass transition temperatures Tg m1.
  • Limiting the amount of a compound containing a structure in which two or more non-condensed aromatic rings are directly chemically bonded in this way is a viewpoint of realizing a pressure-sensitive adhesive having a good balance of flexibility, tackiness and high refractive index. Can be advantageous from.
  • Examples of the ethylenically unsaturated group contained in the monomer (m2) include a (meth) acryloyl group, a vinyl group, a (meth) allyl group and the like.
  • a (meth) acryloyl group is preferable from the viewpoint of polymerization reactivity, and an acryloyl group is more preferable from the viewpoint of flexibility and adhesiveness.
  • a compound (that is, a monofunctional monomer) in which the number of ethylenically unsaturated groups contained in one molecule is 1 is preferably used as the monomer (m2).
  • the content of the monomer (m2) is, for example, 30% by weight or less or 25% by weight or less, and the content of the monomer (m1) is relatively increased to achieve high refraction. From the viewpoint of facilitating rate, it is preferably 20% by weight or less, more preferably 15% by weight or less, less than 12% by weight, less than 10% by weight, or less than 7% by weight. ..
  • the content of the carboxy group-containing monomer in the monomer component is not particularly limited, and is, for example, 0.01% by weight or more (preferably 0.1% by weight or more, more preferably 0.1% by weight or more). Can be 0.3% by weight or more).
  • the content of the carboxy group-containing monomer may be 1% by weight or more, 2% by weight or more, or 4% by weight or more.
  • the upper limit of the content of the carboxy group-containing monomer in the monomer component is set so that the total with the amount of other monomers used does not exceed 100% by weight, and it is appropriate to set it to, for example, 30% by weight or less or 25% by weight or less.
  • the total content of the monomer (m1) and the monomer (m2) in the monomer component constituting the acrylic polymer may be, for example, 31% by weight or more, preferably 51% by weight or more, or 61% by weight or more. , 71% by weight or more.
  • the total content of the monomer (m1) and the monomer (m2) in the monomer component constituting the acrylic polymer is, for example, 76% by weight from the viewpoint of facilitating the effect of these monomers. It may be more than 81% by weight, preferably 86% by weight or more, 91% by weight or more, 96% by weight or more, 99% by weight or more, substantially 100% by weight. But it may be.
  • the monomer component constituting the acrylic polymer may contain a monomer other than the above-mentioned monomer (m1) and the above-mentioned monomer (m2), if necessary.
  • An example of such an optional component is an alkyl (meth) acrylate (hereinafter, also referred to as “monomer (m3)”).
  • the monomer (m3) can be useful for adjusting the flexibility of the pressure-sensitive adhesive and improving the compatibility in the pressure-sensitive adhesive.
  • an alkyl (meth) acrylate having a linear or branched alkyl group having 1 to 20 carbon atoms (that is, C 1-20) at the ester terminal can be preferably used.
  • C 1-20 alkyl (meth) acrylate include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, isopropyl (meth) acrylate, and n- (meth) acrylate.
  • alkyl (meth) acrylates having a homopolymer Tg of ⁇ 20 ° C. or lower are preferably employed as at least a portion of the monomer (m3). Can be done.
  • Such low Tg alkyl (meth) acrylates can help improve the flexibility of the adhesive.
  • the lower limit of Tg of the alkyl (meth) acrylate is not particularly limited, and may be, for example, ⁇ 85 ° C. or higher, ⁇ 75 ° C. or higher, ⁇ 65 ° C. or higher, or ⁇ 60 ° C. or higher.
  • Specific examples of the low Tg alkyl (meth) acrylate include n-butyl acrylate (BA), 2-ethylhexyl acrylate (2EHA), and isononyl acrylate (iNA).
  • the content of the alkyl (meth) acrylate in the monomer component can be set so that the effect of use thereof is appropriately exhibited.
  • the content of the alkyl (meth) acrylate may be, for example, 1% by weight or more, 3% by weight or more, 5% by weight or more, or 8% by weight or more.
  • the content of the alkyl (meth) acrylate may be 15% by weight or more, 30% by weight or more, or 45% by weight or more.
  • the upper limit of the content of the monomer (m3) in the monomer component is set so that the total content with the content of other monomers does not exceed 100% by weight, and can be, for example, less than 50% by weight. In some embodiments, the content of the monomer (m3) can be, for example, less than 35% by weight.
  • the refractive index of alkyl (meth) acrylate is relatively low. Therefore, in order to increase the refractive index, the content of the monomer (m3) in the monomer component is limited, and the content of the monomer (m1) is relatively large. It is advantageous to do.
  • Examples of the above-mentioned other monomers include monomers having functional groups other than hydroxyl groups and carboxy groups (functional group-containing monomers).
  • other monomers that can improve the cohesive force and heat resistance of the pressure-sensitive adhesive include sulfonic acid group-containing monomers, phosphoric acid group-containing monomers, and cyano group-containing monomers.
  • an amide group-containing monomer for example, (meth).
  • amino group-containing monomer for example, aminoethyl (meth) acrylate, N, N-dimethylaminoethyl (meth) acrylate, etc.
  • monomer having a nitrogen atom-containing ring for example, , N-vinyl-2-pyrrolidone, N- (meth) acryloy
  • vinyl ester-based monomers such as vinyl acetate; non-aromatic ring-containing (meth) acrylates such as cyclohexyl (meth) acrylate and isobornyl (meth) acrylate; ethylene, Olefin-based monomers such as butadiene and isobutylene; Chlorine-containing monomers such as vinyl chloride; alkoxy group-containing monomers such as methoxyethyl (meth) acrylate, ethoxyethyl (meth) acrylate and ethoxyethoxyethyl (meth) acrylate; Vinyl ether such as methyl vinyl ether System monomers; and the like.
  • ethoxyethoxyethyl acrylate also known as ethyl carbitol acrylate, homopolymer Tg: ⁇ 67 ° C.
  • the amount used is not particularly limited, and can be appropriately set within a range in which the total amount of the monomer components does not exceed 100% by weight.
  • the content of the other monomer in the monomer component can be, for example, about 35% by weight or less, and is about 25, from the viewpoint of facilitating the effect of improving the refractive index by using the monomer (m1). It is appropriate to set it to about 20% by weight or less (for example, 0 to 25% by weight), and it may be about 20% by weight or less (for example, 0 to 20% by weight), about 10% by weight or less, or about 5% by weight or less. For example, it may be about 1% by weight or less.
  • the technique disclosed herein can be preferably carried out in a manner in which the monomer component is substantially free of the other monomers.
  • the monomer component constituting the acrylic polymer may have a composition in which the amount of the methacryloyl group-containing monomer used is suppressed to a predetermined value or less.
  • the amount of the methacryloyl group-containing monomer used in the monomer component may be, for example, less than 5% by weight, less than 3% by weight, less than 1% by weight, or less than 0.5% by weight. Limiting the amount of the methacryloyl group-containing monomer used in this way can be advantageous from the viewpoint of realizing a pressure-sensitive adhesive having both flexibility and adhesiveness and a high refractive index in a well-balanced manner.
  • the monomer component constituting the acrylic polymer may have a composition that does not contain a methacryloyl group-containing monomer (for example, a composition consisting of only an acryloyl group-containing monomer).
  • the monomer components constituting the base polymer of the viscoelastic layer V 1 e.g., acrylic polymers
  • the monomer components constituting the base polymer of the viscoelastic layer V 1 e.g., acrylic polymers
  • carboxy e.g., carboxy
  • the amount of the carboxy group-containing monomer used in the monomer component may be, for example, less than 1% by weight, preferably less than 0.5% by weight, more preferably less than 0.3% by weight, and 0.1. It may be less than% by weight or less than 0.05% by weight.
  • the monomer components constituting the base polymer of the viscoelastic layer V 1 was, has (other carboxyl group, a sulfonic acid group includes a phosphoric acid group.) Acidic functional groups It is preferable that the amount of the monomer used is limited. As the amount of the acidic functional group-containing monomer used in the monomer component of such an embodiment, the above-mentioned preferable amount of the carboxy group-containing monomer can be applied. Interlayer sheet disclosed herein may be preferably carried out in the manner described above monomer component does not contain an acidic group-containing monomer (i.e. aspect based polymer is an acid-free viscoelastic layer V 1).
  • the base polymer of the pressure-sensitive adhesive layer preferably has a glass transition temperature Tg T based on the composition of the monomer components constituting the polymer, which is approximately 20 ° C. or lower. , Approximately 10 ° C or lower, more preferably 0 ° C or lower, -10 ° C or lower, -20 ° C or lower, -25 ° C or lower, ⁇ 28 ° C or lower, ⁇ 28 ° C or lower, ⁇ It may be 30 ° C. or lower.
  • a low glass transition temperature Tg T can be advantageous from the viewpoint of improving the flexibility of the pressure-sensitive adhesive.
  • the glass transition temperature Tg T may be, for example, ⁇ 60 ° C. or higher, preferably ⁇ 50 ° C. or higher, and more preferably ⁇ 45 ° C. or higher, from the viewpoint of facilitating high refractive index of the pressure-sensitive adhesive. Yes, it may be above -40 ° C, above -35 ° C, above -25 ° C, above -15 ° C, or above -5 ° C. good.
  • the method for obtaining the base polymer of the pressure-sensitive adhesive layer is not particularly limited, and is a solution polymerization method or an emulsion polymerization method.
  • a known polymerization method such as a bulk polymerization method, a suspension polymerization method, and a photopolymerization method can be appropriately adopted.
  • the solution polymerization method may be preferably employed.
  • the polymerization temperature at the time of solution polymerization can be appropriately selected depending on the type of monomer and solvent used, the type of polymerization initiator, etc., and is, for example, about 20 ° C. to 170 ° C. (typically 40 ° C. to 140 ° C.). °C).
  • the desired refractive index can be achieved by using a smaller amount of the refractive index improver. This is preferable from the viewpoint of suppressing deterioration of adhesive properties and optical properties.
  • the upper limit of the refractive index of the refractive index improver is not particularly limited, but from the viewpoint of compatibility in the pressure-sensitive adhesive and the ease of compatibility between high refractive index and flexibility suitable as a pressure-sensitive adhesive, for example, 3.000 or less. It may be 2.500 or less, 2.000 or less, 1.950 or less, 1.900 or less, or 1.850 or less.
  • the molecular weight of the organic material used as an additive ( HRO ) is not particularly limited and can be selected according to the intended purpose.
  • the molecular weight of the additive (H RO ) can be selected, for example, from the range of 30,000 or less.
  • the additive ( HRO ) is preferably a polymer or non-polymer having a lower molecular weight than the base polymer.
  • the molecular weight of the additive (HRO ) is balanced from the viewpoint of achieving a good balance between the effect of increasing the refractive index and other properties (for example, flexibility suitable for an adhesive and optical properties such as haze).
  • the molecular weight of the additive (H RO) may be, for example, 130 or more, or 150 or more.
  • the compound having a fluorene structure examples include the above-mentioned monomer having a fluorene structure, an oligomer which is a homopolymer or a copolymer of such a monomer, and 9,9-bis (4-hydroxyphenyl) fluorene (Refraction rate: 1.68), 9,9-bis (4-aminophenyl) fluorene (refractive rate: 1.73), 9,9-bis (4-hydroxy-3-methylphenyl) fluorene (refractive rate: 1) .68), 9,9-bisphenylfluorene and its derivatives such as 9,9-bis [4- (2-hydroxyethoxy) phenyl] fluorene (refractive index: 1.65) can be mentioned.
  • heterocyclic also called containing organic compound.
  • thioepoxy compound a compound having a triazine ring, and the like.
  • the thioepoxy compound include bis (2,3-epithiopropyl) disulfide described in Japanese Patent No. 3712653 and a polymer thereof (refractive index 1.74).
  • the compound having a triazine ring include a compound having at least one triazine ring (for example, 3 to 40, preferably 5 to 20) in one molecule.
  • the molecular weight of the plasticizing material is preferably 130 or more, preferably 150 or more, and may be 170 or more, from the viewpoint of facilitating the exertion of a sufficient plasticizing effect. , 200 or more, 250 or more, 300 or more. In some embodiments, the molecular weight of the thermoplastic material may be 500 or greater, 1000 or greater, or 2000 or greater. It is preferable that the molecular weight of the thermoplastic material is not too low from the viewpoint of the heat resistance performance of the interlayer sheet and the suppression of contamination of the adherend.
  • thermoplastic material an organic material having a refractive index of about 1.50 or more (more preferably 1.53 or more) can be preferably used.
  • specific examples of compounds that can be options for plasticizing materials include diethylene glycol dibenzoate (refraction: 1.55), dipropylene glycol dibenzoate (refraction: 1.54), 3-phenoxytoluene (refraction: 1.57), 3-Ethylbiphenyl (refraction 1.59), 3-methoxybiphenyl (refraction 1.61), 4-methoxybiphenyl (refraction 1.57), polyethylene glycol dibenzoate, 3-phenoxybenzyl alcohol (refraction 1) .59), triphenyl phosphate (refraction rate 1.56), benzyl benzoate (refraction rate 1.57), 4- (tert-butyl) phenyldiphenyl phosphate (refraction rate 1.56), trimethylphenyl phosphate (refraction rate 1.56) 1.55), butylbenzylphthalate (refraction: 1.55), di
  • Leveling agent In some embodiments, (which may be a viscoelastic layer V 1 and / or viscoelastic layer V 2.) Adhesive layer on the pressure-sensitive adhesive composition used for forming a pressure-sensitive adhesive layer formed from the composition
  • a leveling agent can be contained as necessary for the purpose of improving the appearance (for example, improving the uniformity of thickness) and improving the coatability of the pressure-sensitive adhesive composition.
  • the leveling agent include an acrylic leveling agent, a fluorine-based leveling agent, a silicone-based leveling agent, and the like.
  • an appropriate leveling agent can be selected from commercially available leveling agents and used by a conventional method.
  • the functional group equivalent of the monomer S1 is the sum of the products of the functional group equivalents of each type of monomer and the weight fraction of the monomer. be able to.
  • the content of the monomer S1 in the monomer raw material B can be an appropriate value within a range in which the desired effect is exhibited by using the monomer S1, and is not limited to a specific range. In some embodiments, the content of the monomer S1 in the monomer raw material B may be, for example, 5-60% by weight, 10-50% by weight, or 15-40% by weight.
  • the monomer raw material B may contain, for example, one or more selected from methyl methacrylate (MMA), n-butyl methacrylate (BMA) and 2-ethylhexyl methacrylate (2EHMA) as the acrylic monomer.
  • MMA methyl methacrylate
  • BMA n-butyl methacrylate
  • EHMA 2-ethylhexyl methacrylate
  • acrylic monomer is a (meth) acrylic acid ester having an alicyclic hydrocarbon group.
  • cyclopentyl (meth) acrylate, cyclohexyl (meth) acrylate, isobornyl (meth) acrylate, dicyclopentanyl (meth) acrylate, 1-adamantyl (meth) acrylate and the like can be used. It is not necessary to use a (meth) acrylic acid ester having an alicyclic hydrocarbon group.
  • the Mw of the polymer (B) may be, for example, 5,000 or more, preferably 10,000 or more, and may be 15,000 or more.
  • the Mw of the polymer (B) may be, for example, 200,000 or less, preferably 100,000 or less, 50,000 or less, or 30,000 or less.
  • the polymer (B) can be produced, for example, by polymerizing the above-mentioned monomer by a known method such as a solution polymerization method, an emulsion polymerization method, a bulk polymerization method, a suspension polymerization method, or a photopolymerization method.
  • Chain transfer agents can be used as needed to adjust the molecular weight of the polymer (B). Examples of chain transfer agents used include compounds having a mercapto group such as t-dodecyl mercaptoethanol, mercaptoethanol, ⁇ -thioglycerol; thioglycolic acid esters such as thioglycolic acid and methyl thioglycolate; ⁇ -methylstyrene.
  • the amount of the chain transfer agent used is not particularly limited, and can be appropriately set so that the polymer (B) having a desired molecular weight can be obtained.
  • the amount of the chain transfer agent used per 100 parts by weight of the monomer may be, for example, 0.1 to 5 parts by weight, 0.2 to 3 parts by weight, or 0.5 to 2 parts by weight. good.
  • the amount of the polymer (B) used with respect to 100 parts by weight of the base polymer can be, for example, 0.001 part by weight or more, and 0.01 part by weight or more from the viewpoint of obtaining a higher use effect. It may be 0.03 part by weight or more.
  • the amount of the polymer (B) used may be, for example, 3 parts by weight or less, and it is appropriate to use 1 part by weight or less from the viewpoint of reducing the influence on the refractive index, and 0.5 parts by weight or less. However, it may be 0.1 parts by weight or less.
  • inorganic particles The technique disclosed herein can be preferably carried out in a manner in which inorganic particles as a refractive index improver are substantially not used. However, it is permissible to use inorganic particles as the refractive index improver as long as the application effect of the technique disclosed herein is not significantly impaired.
  • inorganic particles that can be used as a refractive index improver include titania (titanium oxide, TiO 2 ), zirconia ( zinc oxide, ZrO 2 ), aluminum oxide, zinc oxide, tin oxide, copper oxide, barium titanate, and oxidation.
  • examples thereof include inorganic particles composed of inorganic oxides (specifically, metal oxides) such as niobium (Nb 2 O 5 and the like).
  • the amount used is preferably less than 5 parts by weight and more preferably less than 1 part by weight with respect to 100 parts by weight of the base polymer.
  • the amount of the inorganic particles, by weight is preferably not more than 2 times the amount of the additive (H RO), 1 times or less or 0. More preferably, it is 5 times or less.
  • the PSA composition used to form the pressure-sensitive adhesive layer (which may be a viscoelastic layer V 1 and / or viscoelastic layer V 2.), Adjustment of the cohesive force of the pressure-sensitive adhesive
  • a cross-linking agent can be contained if necessary.
  • a cross-linking agent known in the field of adhesives such as an isocyanate-based cross-linking agent, an epoxy-based cross-linking agent, an aziridine-based cross-linking agent, an oxazoline-based cross-linking agent, a melamine-based resin, and a metal chelate-based cross-linking agent shall be used. Can be done.
  • an isocyanate-based cross-linking agent can be preferably used.
  • Another example of the cross-linking agent is a monomer having two or more ethylenically unsaturated groups in one molecule, that is, a polyfunctional monomer.
  • the cross-linking agent may be used alone or in combination of two or more.
  • a bifunctional or higher functional isocyanate compound can be used, for example, aliphatic polyisocyanates such as trimethylene diisocyanate, butylene diisocyanate, hexamethylene diisocyanate (HDI), and dimerate diisocyanate; cyclopentylene diisocyanate.
  • aliphatic polyisocyanates such as trimethylene diisocyanate, butylene diisocyanate, hexamethylene diisocyanate (HDI), and dimerate diisocyanate
  • HDI hexamethylene diisocyanate
  • dimerate diisocyanate dimerate diisocyanate
  • Aromatic isocyanates such as XDI); polyisocyanate modified products obtained by modifying the above isocyanate compounds with allophanate bonds, biuret bonds, isocyanurate bonds, uretdione bonds, urea bonds, carbodiimide bonds, uretonimine bonds, oxadiazine trione bonds, etc.
  • the isocyanate compound may be used alone or in combination of two or more.
  • a bifunctional isocyanate compound and a trifunctional or higher functional isocyanate compound may be used in combination.
  • epoxy-based cross-linking agent examples include bisphenol A, epichlorohydrin-type epoxy resin, ethylene glycidyl ether, polyethylene glycol diglycidyl ether, glycerin diglycidyl ether, glycerin triglycidyl ether, 1,6-hexanediol glycidyl ether, and trimethylol.
  • the amount used is not particularly limited, and is, for example, in the range of about 0.001 part by weight to 5.0 parts by weight with respect to 100 parts by weight of the base polymer. can do.
  • the amount of the cross-linking agent used with respect to 100 parts by weight of the base polymer is preferably 3.0 parts by weight or less, more preferably 2.0 parts by weight or less. It may be 1.0 part by weight or less, 0.5 part by weight or less, or 0.2 part by weight or less.
  • a cross-linking catalyst may be used to allow the cross-linking reaction to proceed more effectively.
  • the cross-linking catalyst include metal-based cross-linking catalysts such as tetra-n-butyl titanate, tetraisopropyl titanate, ferric nasem, butyl tin oxide, and dioctyl tin dilaurate. Of these, tin-based cross-linking catalysts such as dioctyl tin dilaurate are preferable.
  • the amount of the cross-linking catalyst used is not particularly limited.
  • the pressure-sensitive adhesive composition can contain a compound that causes keto-enol tautomerism as a cross-linking retarder. Thereby, the effect of extending the pot life of the pressure-sensitive adhesive composition can be realized.
  • a compound that causes keto-enol tautomerism can be preferably used in a pressure-sensitive adhesive composition containing an isocyanate-based cross-linking agent.
  • Various ⁇ -dicarbonyl compounds can be used as the compound that causes keto-enol telecommunication.
  • ⁇ -diketones acetylacetone, 2,4-hexanedione, etc.
  • acetoacetic esters methyl acetoacetate, ethyl acetoacetate, etc.
  • the compounds that cause keto-enol tautomerism can be used alone or in combination of two or more.
  • the amount of the compound that causes keto-enol telecommunication can be, for example, 0.1 parts by weight or more and 20 parts by weight or less, and 0.5 parts by weight or more and 10 parts by weight or less, based on 100 parts by weight of the base polymer. It may be 1 part by weight or more and 5 parts by weight or less.
  • PSA layer in the art disclosed herein, the may contain a tackifier.
  • the pressure-sensitive adhesive include rosin-based pressure-sensitive adhesive resin, terpen-based pressure-sensitive adhesive resin, phenol-based pressure-sensitive adhesive resin, hydrocarbon-based pressure-sensitive adhesive resin, ketone-based pressure-sensitive adhesive resin, polyamide-based pressure-sensitive adhesive resin, epoxy-based pressure-sensitive adhesive resin, and elastomer.
  • a known pressure-sensitive adhesive resin such as a system-based pressure-sensitive adhesive resin can be used. These can be used alone or in combination of two or more.
  • the peel strength of the interlayer sheet with respect to the glass plate is about 1.0 N / 25 mm or more (for example, 1.5 N / 25 mm or more). Is 2N / 25mm or more, more preferably 3N / 25mm or more, 4N / 25mm or more, 6N / 25mm or more, 8N / 25mm or more, 10N / 25mm or more, 12N / 25mm or more. ..
  • the upper limit of the peel strength is not particularly limited, and may be, for example, 30 N / 25 mm or less, 25 N / 25 mm or less, or 20 N / 25 mm or less.
  • the interlayer sheet in addition to the viscoelastic layer V 1 described above, the viscoelastic layer laminated on the viscoelastic layer V 1 (adhesive layer) V 2 may be further included.
  • the viscoelastic layer V 2 is 'is V2, the storage modulus G 25 ° C. of the viscoelastic layer V 1' storage modulus G 25 ° C. is preferably lower than the V1. That is, it is preferable that G'V2 (25) ⁇ G'V1 (25).
  • Such configuration interlayer sheet is due to the contribution of the viscoelastic layer V 2, it can be excellent in more flexible.
  • Storage modulus G 'V2 (25) is not particularly limited, may be in the range, for example, 1.0 kPa ⁇ 500 kPa. From the viewpoint of enhancing the effect of the following improvement for softening or deformation due to the viscoelastic layer V 2, in some embodiments, the storage modulus G 'V2 (25) is suitably not more than 400 kPa, 300 kPa It is preferably 200 kPa or less (for example, 180 kPa or less, or 150 kPa) or less, and may be 120 kPa or less, 90 kPa or less, or 70 kPa or less.
  • the refractive index n 2 of the V 2 are viscoelastic layer (adhesive layer) lower than the refractive index n 1 of V 1.
  • the refractive index n 2 of the pressure-sensitive adhesive layer V 2 if lower than the refractive index n 1 of the pressure-sensitive adhesive layer V 1 is not particularly limited, it may be, for example, in the range of about 1.35 to 1.55 ..
  • the refractive index n 2 of the viscoelastic layer V 2 is preferably 1.49 or less, more preferably 1.47 or less (for example, 1.46 or less, or 1.45 or less), 1.43 or less, 1.41 or less, and 1 It may be .40 or less.
  • the refractive index n 2 of the viscoelastic layer V 2 may be for example 1.36 or more, 1.38 It may be more than or equal to, 1.40 or more, or 1.42 or more.
  • the type of the pressure-sensitive adhesive constituting the viscoelastic layer V 2 is not particularly limited.
  • the pressure-sensitive adhesive constituting the viscoelastic layer V 2 is an acrylic polymer, a rubber-based polymer (for example, natural rubber, synthetic rubber, a mixture thereof, etc.), a polyester-based polymer, a urethane-based polymer, or a poly, which can be used in the field of pressure-sensitive adhesives. It may contain one or more of various rubber-like polymers such as an ether-based polymer, a silicone-based polymer, a polyamide-based polymer, and a fluorine-based polymer as a base polymer.
  • the acrylic polymer includes, for example, an alkyl (meth) acrylate and may further contain another monomer (copolymerizable monomer) copolymerizable with the alkyl (meth) acrylate. Polymers are preferred.
  • the content of the alkyl (meth) acrylate in the monomer raw material may be, for example, 10% by weight or more, 25% by weight or more, 35% by weight or more, or 45% by weight or more.
  • the acrylic polymer may be a polymer of a monomer component containing an alkyl (meth) acrylate as a main monomer and further containing the copolymerizable monomer as a submonomer.
  • the main monomer means a component that occupies more than 50% by weight of the monomer composition in the above-mentioned monomer raw material. More than 55% by weight or more than 60% by weight of the above monomer composition may be alkyl (meth) acrylate.
  • the copolymerizable monomer can be useful for introducing cross-linking points into the acrylic polymer and enhancing the cohesive force of the acrylic polymer.
  • Examples of the copolymerizable monomer include a carboxy group-containing monomer, a hydroxyl group-containing monomer, an acid anhydride group-containing monomer, an amide group-containing monomer, an amino group-containing monomer, a monomer having a nitrogen atom-containing ring, a sulfonic acid group-containing monomer, and phosphorus.
  • One or more functional group-containing monomers such as an acid group-containing monomer can be used.
  • copolymerizable monomers include vinyl ester-based monomers such as vinyl acetate, aromatic vinyl compounds such as styrene, non-aromatic ring-containing (meth) acrylates, and alkoxy group-containing monomers.
  • vinyl ester-based monomers such as vinyl acetate
  • aromatic vinyl compounds such as styrene
  • non-aromatic ring-containing (meth) acrylates and alkoxy group-containing monomers.
  • alkoxy group-containing monomers Specific examples, but like those described above as monomers that may be used as the base polymer of the viscoelastic layer V 1 is mentioned, but not limited to.
  • an acrylic polymer in which a carboxy group-containing monomer and / or a hydroxyl group-containing monomer is copolymerized is preferable as the copolymerizable monomer.
  • the carboxy group-containing monomer include acrylic acid and methacrylic acid.
  • the hydroxyl group-containing monomer include 2-hydroxyethy
  • a fluorine-containing monomer can be used as the copolymerizable monomer in order to lower the refractive index n 2 of the pressure-sensitive adhesive layer V 2.
  • the content of the fluorine-containing monomer in the monomer raw material may be, for example, 10% by weight or more, 25% by weight or more, or 35% by weight or more.
  • the content of the fluorine-containing monomer is preferably 40 wt% or more, more preferably 45 wt% or more, 55 wt%
  • the above is more preferable, and it may be 60% by weight or more, 75% by weight or more, 85% by weight or more, 90% by weight or more, or 95% by weight or more.
  • the upper limit of the content of the fluorine-containing monomer in the monomer raw material is not particularly limited, and may be 100% by weight. In some embodiments, from the viewpoint of cohesiveness, etc.
  • the content of the fluorine-containing monomer is suitably to be at 99.9 wt% or less, it is 99.5 or less Preferably, it may be 99% by weight or less, 97% by weight or less, or 92% by weight or less.
  • the fluorine-containing monomer may be used alone or in combination of two or more.
  • a fluorine-containing acrylic monomer can be preferably used as the fluorine-containing monomer.
  • the fluorine-containing acrylic monomer is not particularly limited as long as it is an acrylic monomer having at least one fluorine atom in the molecule.
  • a fluorine-containing (meth) acrylic acid ester can be preferably used.
  • Preferable examples of the fluorine-containing (meth) acrylic acid ester include those having a fluorinated hydrocarbon group at the ester terminal.
  • the fluorinated hydrocarbon group include a fluorinated aliphatic hydrocarbon group, a fluorinated alicyclic hydrocarbon group, and a fluorinated aromatic hydrocarbon group.
  • a fluorinated aliphatic hydrocarbon group is suitable.
  • the fluorinated aliphatic hydrocarbon group include a fluorinated alkyl group.
  • the aliphatic hydrocarbon moiety may be linear or branched.
  • the fluorine atom may be bonded to any carbon atom of the aliphatic hydrocarbon group moiety.
  • the number of fluorine atoms bonded to one carbon atom may be singular or plural.
  • the number of carbon atoms to which the fluorine atom is bonded is not particularly limited.
  • the number of carbon atoms at the hydrocarbon group site is not particularly limited.
  • a fluorinated aliphatic hydrocarbon group having, for example, about 1 to 18 (preferably 1 to 12) carbon atoms is preferable in consideration of compatibility with other copolymerizable monomers.
  • Specific examples of the fluoride aliphatic hydrocarbon group include methyl fluoride groups such as trifluoromethyl group, difluoromethyl group and monofluoromethyl group; pentafluoroethyl group, 1,1,2,2-tetrafluoroethyl group.
  • 1,2,2,2-tetrafluoroethyl group 1,1,2-trifluoroethyl group, 1,2,2-trifluoroethyl group, 2,2,2-trifluoroethyl group, 1,1 -Difluoroethyl group, 1,2-difluoroethyl group, 2,2-difluoroethyl group, 1-monofluoroethyl group, 2-monofluoroethyl group and other ethyl fluoride groups; and the like.
  • fluorinated alkyl group having 3 or more carbon atoms as in the case of the above-exemplified methyl fluorinated group and ethyl fluorinated group, one or more carbon atoms in any one or more of the carbon atoms in the alkyl group moiety may be used.
  • Various alkyl fluorinated groups to which the fluorine atom of the above is bonded can be exemplified.
  • Examples of the fluorinated alicyclic hydrocarbon group include a fluorinated cycloalkyl group. Similar to the above-mentioned fluorinated aliphatic hydrocarbon group, in the fluorinated alicyclic hydrocarbon group, the fluorine atom may be bonded to any carbon atom of the alicyclic hydrocarbon group into one carbon atom. The bonded fluorine atom may be singular or plural. Further, the number of carbon atoms to which the fluorine atom is bonded is not particularly limited.
  • the fluorinated alicyclic hydrocarbon group includes, for example, a cyclohexyl group having one fluorine atom such as a 2-fluorocyclohexyl group, a 3-fluorocyclohexyl group, and a 4-fluorocyclohexyl group; a 2,4-difluorocyclohexyl group, 2 , A cyclohexyl group having two fluorine atoms such as a 6-difluorocyclohexyl group; a cyclohexyl group having three fluorine atoms such as a 2,4,6-trifluorocyclohexyl group and the like are included.
  • a cyclohexyl group having one fluorine atom such as a 2-fluorocyclohexyl group, a 3-fluorocyclohexyl group, and a 4-fluorocyclohexyl group
  • the fluorinated hydrocarbon group may or may not have a substituent.
  • a substituent is not particularly limited, and examples thereof include a hydrocarbon group such as an alkyl group, an alkoxy group, a hydroxy group, a carboxy group, an amino group, a nitro group, a cyano group, and a halogen atom.
  • a hydrocarbon group such as an alkyl group, an alkoxy group, a hydroxy group, a carboxy group, an amino group, a nitro group, a cyano group, and a halogen atom.
  • one type may be used alone or two or more types may be used in combination.
  • Fluorine atom-containing (meth) acrylic acid ester [fluorinated (meth) acrylate] includes, for example, fluorine atom-containing (meth) acrylic acid alkyl ester [fluorinated alkyl (meth) acrylate] and fluorine atom-containing (meth) acrylic acid.
  • Cycloalkyl esters [fluorinated cycloalkyl (meth) acrylates], fluorine atom-containing (meth) acrylic acid aryl esters [fluorinated aryl (meth) acrylates] and the like are included.
  • fluorinated alkyl (meth) acrylate As the fluorine atom-containing (meth) acrylic acid ester, fluorinated alkyl (meth) acrylate (particularly, fluorinated alkyl acrylate) is suitable.
  • alkyl fluorinated (meth) acrylate examples include 2,2,2-trifluoroethyl acrylate (trade name "Viscoat 3F" manufactured by Osaka Organic Chemical Industry Co., Ltd.), 2,2,3,3-tetrafluoro.
  • Propyl acrylate (trade name "Viscoat 4F” manufactured by Osaka Organic Chemical Industry Co., Ltd.), 1H, 1H, 5H-octafluoropentyl acrylate (trade name “Viscoat 8F” manufactured by Osaka Organic Chemical Industry Co., Ltd.), 1H, 1H, 5H-octafluoropentyl methacrylate (trade name "Viscoat 8FM” manufactured by Osaka Organic Chemical Industry Co., Ltd.), 2- (Heptadecafluorononyl) ethyl acrylate (trade name "FA-108” manufactured by Kyoeisha Chemical Co., Ltd.) Etc.), 1H, 1H, 2H, 2H-tridecafluorooctyl acrylate (trade name "Viscoat 13F” manufactured by Osaka Organic Chemical Industry Co., Ltd.), and the like.
  • the number of carbon atoms of the fluorinated alkyl group in the fluorinated alkyl (meth) acrylate is preferably 3 or more, preferably 4 or more, from the viewpoint of the effect of lowering the refractive index, flexibility, and the like.
  • the above is more preferable, 6 or more or 7 or more is further preferable, and 8 or more is particularly preferable.
  • the number of carbon atoms of the fluorinated alkyl group is preferably 18 or less, preferably 14 or less, more preferably 12 or less, and may be 10 or less. It may be 9 or less.
  • the alkyl fluorinated group may have 7 or less carbon atoms or 5 or less carbon atoms.
  • the fluorine atom-containing (meth) acrylic acid ester is preferably a fluorinated alkyl (meth) acrylate in which fluorine is not bonded to the carbon at the 1-position of the alkyl group, for example, 1H, 1H, 2H. , 2H-Tridecafluorooctyl acrylate, a fluorinated alkyl (meth) acrylate in which fluorine is not bonded to either the 1-position carbon or the 2-position carbon of the alkyl group can be preferably adopted.
  • the content of the fluorine-containing acrylic monomer in the monomer raw material may be, for example, 10% by weight or more, 25% by weight or more, or 35% by weight or more.
  • the content of the fluorine-containing acrylic monomer is preferably 40 wt% or more, more preferably 45 wt% or more, It is more preferably 55% by weight or more, 60% by weight or more, 75% by weight or more, 85% by weight or more, 90% by weight or more, or 95% by weight or more.
  • the upper limit of the content of the fluorine-containing acrylic monomer in the monomer raw material is not particularly limited, and may be 100% by weight.
  • the content of the fluorine-containing acrylic monomer is suitably to be at 99.9 wt% or less, is 99.5 or less It is preferably 99% by weight or less, 97% by weight or less, and 92% by weight or less.
  • the fluorine-containing acrylic monomer may be used alone or in combination of two or more.
  • One or more functional group-containing monomers such as N-vinyl cyclic amides such as pyrrolidone), sulfonic acid group-containing monomers, and phosphoric acid group-containing monomers can be used.
  • Other examples of copolymerizable monomers include vinyl ester-based monomers such as vinyl acetate, aromatic vinyl compounds such as styrene, and non-aromatic ring-containing (meth) such as cycloalkyl (meth) acrylate and isobornyl (meth) acrylate. Acrylate, alkoxy group-containing monomer; and the like can be mentioned.
  • the content of the hydroxyl group-containing monomer in the monomer raw material is not particularly limited, and may be, for example, 0.01% by weight or more (preferably 0.1% by weight or more, more preferably 0.5% by weight or more). In some embodiments, the content of the hydroxyl group-containing monomer may be 0.7% by weight or more, 0.9% by weight or more, or 1.5% by weight or more of the monomer raw material. There may be.
  • the upper limit of the content of the hydroxyl group-containing monomer is not particularly limited, and may be, for example, 15% by weight or less or 10% by weight or less.
  • the content of the hydroxyl group-containing monomer in the monomer raw material is preferably less than 10% by weight, preferably less than 5% by weight, and 3% by weight. It may be less than%, less than 2.5% by weight, or less than 1.5% by weight.
  • the metallic material may be disposed in contact or in proximity to the viscoelastic layer V 2 (e.g., a metal wire or a metal film that may be present on an adherend Etc.), which is also advantageous from the viewpoint of suppressing corrosion.
  • the interlayer sheet disclosed herein can be preferably carried out in a manner in which the monomer raw material does not contain a carboxy group-containing monomer.
  • the monomer raw material for preparing the base polymer of the viscoelastic layer V 2 are acidic functional groups (including other carboxyl group, a sulfonic acid group, a phosphoric acid group or the like.) It is preferable that the content of the monomer having is limited. As the content of the acidic functional group-containing monomer in the monomer raw material of such an embodiment, the above-mentioned preferable content of the carboxy group-containing monomer can be applied. Interlayer sheet disclosed herein may be preferably carried out in the manner described above monomer raw material does not contain an acidic group-containing monomer (i.e. aspect based polymer is an acid-free viscoelastic layer V 2).
  • the base polymer of the pressure-sensitive adhesive layer V 2 can be prepared by appropriately adopting a known polymerization method like the base polymer of the pressure-sensitive adhesive layer V 1.
  • the weight average molecular weight of the base polymer (Mw) of not particularly limited, for example, may range approximately of 10 ⁇ 10 4 ⁇ 500 ⁇ 10 4, be in the range of about 20 ⁇ 10 4 ⁇ 200 ⁇ 10 4 good.
  • Mw of the base polymer of the pressure-sensitive adhesive layer V 2 is suitably not less 0.99 ⁇ 10 4 or less, 120 ⁇ 10 4 or less (e.g.
  • the amount of the isocyanate-based cross-linking agent used per 100 parts by weight of the base polymer may be, for example, 0.005 parts by weight or more. It may be 01 parts by weight or more, 0.05 parts by weight or more, or 0.08 parts by weight or more.
  • a viscoelastic material constituting each of the viscoelastic layer V 1, V 2, respectively, solvent type, active energy ray-curable, aqueous dispersion type pressure-sensitive adhesive in the form of a hot melt type or the like It can be a pressure-sensitive adhesive obtained by curing the agent composition by drying, cross-linking, polymerization, cooling, or the like, that is, a cured product of the pressure-sensitive adhesive composition.
  • the curing means for example, drying, cross-linking, polymerization, cooling, etc.
  • only one type may be applied, or two or more types may be applied simultaneously or in multiple stages.
  • either one or both of the viscoelastic layers V 1 and V 2 may be a post-curable pressure-sensitive adhesive layer, which is a non-post-curable pressure-sensitive adhesive layer.
  • the pressure-sensitive adhesive layer having post-curability refers to a pressure-sensitive adhesive layer that can be further cured by irradiation with heat or active energy rays (for example, ultraviolet rays).
  • the post-curable pressure-sensitive adhesive layer include a pressure-sensitive adhesive layer having an unreacted ethylenically unsaturated group in the side chain of the base polymer, and a pressure-sensitive adhesive layer containing an unreacted polyfunctional monomer.
  • the thickness of the viscoelastic layer V 1 is not particularly limited, and can be, for example, 3 ⁇ m or more, preferably 5 ⁇ m or more. According to the thickness 5 ⁇ m or more viscoelastic layers V 1, good adhesion properties can be easily obtained. Further, the viscoelastic layer V 1 of the such thickness tends to bond with good adhesion to the adherend by absorbing irregularities that may be present in the adherend surfaces. It is preferable that the thickness of the viscoelastic layer V 1 is 5 ⁇ m or more from the viewpoint of preventing coloring and color unevenness due to light interference.
  • the technique disclosed herein can be preferably carried out, for example, in an embodiment in which the thickness of the viscoelastic layer V 1 is in the range of 3 ⁇ m to 200 ⁇ m (more preferably 5 ⁇ m to 100 ⁇ m).
  • the thickness of the viscoelastic layer V 2 can be selected from the same range as the thickness of the viscoelastic layer V 1 exemplified above.
  • the thickness of the viscoelastic layer V 1 and the thickness of the viscoelastic layer V 2 may be about the same or different.
  • the thickness of the pressure-sensitive adhesive layer is the thickness of the interlayer sheet.
  • the interlayer sheet (adhesive sheet) according to some aspects may be in the form of a pressure-sensitive adhesive sheet with a base material having an pressure-sensitive adhesive layer on one side or both sides of the support base material.
  • the material of the supporting base material is not particularly limited, and can be appropriately selected depending on the purpose of use, the mode of use, and the like of the adhesive sheet.
  • Non-limiting examples of base materials that can be used include polyester films containing polyester as a main component such as polypropylene (PP) and ethylene-propylene copolymer, polyethylene terephthalate (PET), polybutylene terephthalate (PBT), and polyethylene na.
  • Polyester film containing polyester as the main component such as phthalate (PEN), plastic film such as polyvinyl chloride film containing polyvinyl chloride as the main component; foams such as polyurethane foam, polyethylene (PE) foam, and polychloroprene foam.
  • Foam sheet woven fabrics and non-woven fabrics made of various fibrous substances (natural fibers such as hemp and cotton, synthetic fibers such as polyester and vinylon, semi-synthetic fibers such as acetate, etc.) alone or in a blended manner; Papers such as Japanese paper, high-quality paper, kraft paper, and crepe paper; metal foils such as aluminum foil and copper foil; and the like can be mentioned.
  • a base material having a composite structure of these may be used. Examples of such a composite base material include a base material having a structure in which a metal foil and the plastic film are laminated, a plastic base material reinforced with an inorganic fiber such as glass cloth, and the like.
  • the film base material may be a porous base material such as a foam film or a non-woven fabric sheet, or may be a non-porous base material, and may be a porous layer and a non-porous layer. May be a base material having a laminated structure.
  • the film base material those containing an independently shape-maintainable (self-supporting or independent) resin film as a base film can be preferably used.
  • the "resin film” means a resin film (of voidless) having a non-porous structure and typically containing substantially no bubbles. Therefore, the resin film is a concept that is distinguished from foam films and non-woven fabrics.
  • the resin film one that can independently maintain its shape (self-supporting or independent) can be preferably used.
  • the resin film may have a single-layer structure or a multi-layer structure having two or more layers (for example, a three-layer structure).
  • Examples of the material constituting the resin film include a polyester-based resin containing a polyester as a main component, such as polyethylene terephthalate (PET), polybutylene terephthalate (PBT), and polyethylene naphthalate (PEN), polyethylene (PE), and polypropylene (PP).
  • PET polyethylene terephthalate
  • PBT polybutylene terephthalate
  • PEN polyethylene naphthalate
  • PE polyethylene
  • PP polypropylene
  • the resin film may be formed by using a resin material containing one kind of such a resin alone, or may be formed by using a resin material in which two or more kinds are blended. May be good.
  • the resin film may be unstretched or stretched (for example, uniaxially stretched or biaxially stretched).
  • a blended film or the like can be preferably used.
  • preferable resin films from the viewpoint of strength and dimensional stability include PET film, PEN film, PPS film and PEEK film. From the viewpoint of availability, PET film and PPS film are particularly preferable, and PET film is particularly preferable.
  • Known resin films include light stabilizers, antioxidants, antistatic agents, colorants (dyees, pigments, etc.), fillers, slip agents, antiblocking agents, etc., as long as the effects of the present invention are not significantly impaired.
  • Additives can be blended as needed.
  • the blending amount of the additive is not particularly limited, and can be appropriately set according to the use of the pressure-sensitive adhesive sheet and the like.
  • the manufacturing method of the resin film is not particularly limited.
  • conventionally known general resin film molding methods such as extrusion molding, inflation molding, T-die casting molding, and calendar roll molding can be appropriately adopted.
  • the transmittance meter As the transmittance meter, the product name "HAZEMETER HM-150" manufactured by Murakami Color Technology Research Institute or its equivalent is used.
  • a preferable example of the light-transmitting base material is a resin film having light-transmitting property.
  • the light-transmitting substrate may be an optical film.
  • the thickness of the base material is not particularly limited and can be selected according to the purpose and mode of use of the interlayer sheet.
  • the thickness of the base material may be, for example, 500 ⁇ m or less, preferably 300 ⁇ m or less from the viewpoint of handleability and processability of the interlayer sheet, 150 ⁇ m or less, 100 ⁇ m or less, 50 ⁇ m or less, and 25 ⁇ m. It may be less than or equal to 10 ⁇ m or less. As the thickness of the base material becomes smaller, the ability to follow the surface shape of the adherend tends to improve. Further, from the viewpoint of handleability, processability and the like, the thickness of the base material may be, for example, 2 ⁇ m or more, 10 ⁇ m or more, or 25 ⁇ m or more.
  • the thickness of the interlayer sheet may be, for example, 1000 ⁇ m or less, 350 ⁇ m or less, 200 ⁇ m or less, 120 ⁇ m or less. It may be 75 ⁇ m or less, or 50 ⁇ m or less. Further, the thickness of the interlayer sheet may be, for example, 10 ⁇ m or more, 25 ⁇ m or more, 80 ⁇ m or more, or 130 ⁇ m or more from the viewpoint of handleability and the like.
  • the thickness of the interlayer sheet means the thickness of the portion to be attached to the adherend. For example, in the interlayer sheet 1 having the configuration shown in FIG. 1, it refers to the thickness from the first surface (adhesive surface) 10A of the pressure-sensitive adhesive layer to the second surface 20B of the supporting base material, and does not include the thickness of the release liner 30. ..
  • the interlayer sheet (adhesive sheet) disclosed herein may take the form of an adhesive product in which the surface (adhesive surface) of the adhesive layer is brought into contact with the release surface of the release liner. Therefore, the present specification provides an interlayer sheet (adhesive product) with a release liner including any of the interlayer sheets disclosed herein and a release liner having a release surface that abuts on the adhesive surface of the interlayer sheet. NS.
  • the release liner is not particularly limited, and for example, a release liner having a release treatment layer on a release liner base material such as a resin film or paper (paper in which a resin such as polyethylene is laminated) or a fluorine-based release liner.
  • a release liner base material such as a resin film or paper (paper in which a resin such as polyethylene is laminated) or a fluorine-based release liner.
  • a release liner made of a resin film formed of a low adhesive material such as a polymer (polytetrafluoroethylene or the like) or a polyolefin resin (polyethylene, polypropylene, etc.) can be used.
  • the peeling treatment layer may be formed by surface-treating the peeling liner base material with a peeling treatment agent.
  • the stripping agent may be a known stripping agent such as a silicone-based stripping agent, a long-chain alkyl-based stripping agent, a fluorine-based stripping agent, or molybdenum sulfide (IV).
  • a release liner having a release treatment layer with a silicone-based release treatment agent can be preferably adopted.
  • the thickness and forming method of the peeling treatment layer are not particularly limited, and can be set so that appropriate peeling property is exhibited on the adhesive surface side surface of the peeling liner.
  • a release liner having a release treatment layer on a resin film (hereinafter, also referred to as a release film base material) as a release liner base material (hereinafter, peeling).
  • a release film base material a resin film
  • peeling a release liner base material
  • a film a release liner base material
  • Various plastic films can be used as the release film base material.
  • a plastic film is typically a non-porous sheet, a concept that distinguishes it from, for example, non-woven fabrics (ie, does not include non-woven fabrics).
  • polyester resins such as polyethylene terephthalate (PET), polybutylene terephthalate (PBT), and polyethylene naphthalate (PEN), polyethylene (PE), polypropylene (PP), and ethylene-propylene co-weight.
  • polyolefin resin such as ethylene-butene copolymer, cellulose resin such as triacetyl cellulose, acetate resin, polysulfone resin, polyether sulfone resin, polycarbonate resin, polyamide resin, polyimide resin, norbornene resin
  • Cyclic polyolefin resin such as resin, (meth) acrylic resin, polyvinyl chloride resin, polyvinylidene chloride resin, polystyrene resin, polyvinyl alcohol resin, ethylene-vinyl acetate copolymer resin, ethylene-vinyl alcohol co-weight Examples thereof include a coalesced resin, a polyarylate resin, and a polyphenylene sulfide resin.
  • a release film base material formed from any one or a mixture of two or more of these resins can be used.
  • a preferable release film base material includes a polyester-based resin film (for example, PET film) formed from a polyester-based resin.
  • the plastic film used as the above-mentioned release film base material may be any of a non-stretched film, a uniaxially stretched film, and a biaxially stretched film. Further, the plastic film may have a single-layer structure or a multi-layer structure including two or more sub-layers.
  • the plastic film is an adhesive sheet containing antioxidants, antioxidants, heat stabilizers, light stabilizers, ultraviolet absorbers, colorants such as pigments and dyes, lubricants, fillers, antioxidants, nucleating agents, etc.
  • a known additive that can be used for the release film base material of the above may be blended. In the multi-layered plastic film, each additive may be blended in all sublayers or only in some sublayers.
  • a release liner (hereinafter, also referred to as one release liner) arranged on one adhesive surface and the other.
  • the release liner (hereinafter, also referred to as the other release liner) arranged on the adhesive surface of the above may have the same material and composition, or may have a different material and composition. ..
  • the thickness of the release liner (preferably the release film) is not particularly limited, and may be, for example, about 10 ⁇ m to 500 ⁇ m. From the viewpoint of the strength and dimensional stability of the release liner, the thickness of the release liner is preferably 20 ⁇ m or more, preferably 30 ⁇ m or more, 35 ⁇ m or more, 40 ⁇ m or more, or 45 ⁇ m or more. good. Further, from the viewpoint of handleability of the release liner (for example, ease of winding), the thickness of the release liner is preferably 300 ⁇ m or less, preferably 250 ⁇ m or less, and may be 200 ⁇ m or less. It may be 150 ⁇ m or less, or 130 ⁇ m or less.
  • the thickness of the release liner is approximately 125 ⁇ m or less, may be approximately 115 ⁇ m or less, may be approximately 105 ⁇ m or less, may be approximately 90 ⁇ m or less, and may be approximately 70 ⁇ m or less.
  • the thicknesses of the release liners may be the same or different. In some aspects, from the viewpoint of peeling workability and the like, it is preferable that one peeling liner and the other peeling liner have different thicknesses, for example, the thicker peeling liner has a thinner thickness.
  • the thickness of the release liner is preferably about 1.1 times or more (for example, about 1.25 times or more. The upper limit is not particularly limited, but for example, 5 times or less).
  • the release liner (preferably the release film) is often limited in that the arithmetic mean roughness Ra of the surface on the adhesive surface side is limited to a predetermined value or less (for example, about 100 nm or less, further less than 50 nm). It is preferable from the viewpoint of realizing an adhesive surface having surface smoothness.
  • the arithmetic mean roughness Ra of the adhesive surface side surface of the release liner is, for example, preferably about 30 nm or less, more preferably about 25 nm or less, about 20 nm or less, and about 18 nm or less. It may be.
  • the arithmetic mean roughness Ra may be, for example, about 5 nm or more, about 10 nm or more, or about 15 nm or more. ..
  • both the adhesive surface side surfaces of both release liners satisfy any of the above-mentioned arithmetic mean roughness Ra. Is preferable.
  • the arithmetic mean roughness Ra of the adhesive surface side surfaces of both release liners may be about the same or different.
  • the release liner (preferably a release film) preferably has a maximum height Rz of the surface on the adhesive surface side of 700 nm or less from the viewpoint of realizing an adhesive surface having high surface smoothness.
  • the maximum height Rz of the adhesive surface side surface of the release liner is preferably about 600 nm or less, may be about 500 nm or less, may be about 400 nm or less, and may be about 300 nm or less.
  • the maximum height Rz may be, for example, about 50 nm or more, about 80 nm or more, or about 100 nm or more. It may be about 200 nm or more, and may be about 300 nm or more.
  • the adhesive surface side surfaces of both release liners satisfy any of the above-mentioned maximum heights Rz. Is preferable.
  • the maximum height Rz of the adhesive surface side surfaces of both release liners may be about the same or different.
  • the arithmetic mean roughness Ra and the maximum height Rz of the back surface (opposite surface of the adhesive layer side) of the release liner (preferably the release film) are not particularly limited.
  • the arithmetic mean roughness Ra on the back surface of the peeling liner may be, for example, more than 30 nm (for example, more than 35 nm, more preferably about 50 nm or more) from the viewpoint of productivity and the like.
  • the maximum height Rz of the back surface of the release liner may be, for example, more than 400 nm (for example, about 500 nm or more) or more than 800 nm (for example, 1000 nm or more) from the viewpoint of productivity and the like.
  • the arithmetic mean roughness Ra and the maximum height Rz of the peeled film surface can be adjusted by the selection of the film material, the molding method, the surface treatment such as the peeling treatment, and the like. For example, adjusting the smoothness of the layers constituting the peelable surface (anti-blocking layer, hard coat layer, oligomer prevention layer, etc.), reducing the amount of filler particles in the surface layer or the release film base material, or eliminating the use (particle-free). ), In addition, adjustment of stretching conditions and the like can be mentioned.
  • the arithmetic mean roughness Ra and the maximum height Rz of the surface of the release liner (preferably the release film) are measured using a non-contact type surface roughness measuring device.
  • a non-contact type surface roughness measuring device a light interference type surface roughness measuring device is used, and for example, a three-dimensional optical profiler (trade name "NewView7300", manufactured by ZYGO) or an equivalent product thereof can be used.
  • a glass plate sida lime glass plate manufactured by MATSUNAMI, thickness 1.3 mm
  • the surface shape can be measured using a three-dimensional optical profiler (trade name "NewView7300", manufactured by ZYGO).
  • the interlayer sheet disclosed herein can be used by being bonded to various adherends.
  • the constituent material (adhesion material) of the adherend is not particularly limited, but for example, copper, silver, gold, iron, tin, palladium, aluminum, nickel, titanium, chromium, indium, and zinc. Etc., or metal materials such as alloys containing two or more of these, for example, polyimide-based resin, acrylic-based resin, polyether nitrile-based resin, polyether sulfone-based resin, polyester-based resin (PET-based resin, polyethylene naphthalate-based).
  • Polyvinyl chloride resins Polyphenylene sulfide resins, polyether ether ketone resins, polyamide resins (so-called aramid resins, etc.), polyarylate resins, fluorine resins, polycarbonate resins, diacetyl celluloses and triacetyls.
  • Various resin materials such as cellulose-based polymers such as cellulose, vinyl butyral polymers, liquid crystal polymers, and carbon materials such as graphene, alumina, zirconia, titania, SiO 2 , ITO (indium tin oxide), Metal oxides such as ATO (antimonated tin oxide) and their mixtures, nitrides such as aluminum nitride, silicon nitride, titanium nitride, gallium nitride, indium nitride and their composites, alkaline glass, non-alkali glass, quartz glass, hokei Examples thereof include inorganic materials such as acid glass and sapphire glass.
  • the interlayer sheet disclosed herein can be used by being attached to a member (for example, an optical member) whose surface is at least composed of the above materials.
  • the interlayer sheet disclosed here can be used in a bonding mode that does not require a treatment of heating to a temperature higher than a temperature range of about room temperature (for example, 20 ° C. to 35 ° C.) after being bonded to an adherend. Further, if it is permissible depending on the constituent material of the interlayer sheet (for example, the material of the base material) and the type of the adherend, after bonding to the adherend, at the time of bonding, and before bonding, The heat treatment may be performed at at least any timing. The heat treatment can be performed for the purpose of improving the adhesion of the pressure-sensitive adhesive to the adherend and promoting adhesion.
  • the member or material to which the interlayer sheet is attached or laminated may have light transmission.
  • the total light transmittance of the adherend may be, for example, more than 50%, and may be 70% or more.
  • the total light transmittance of the adherend is 80% or more, more preferably 90% or more, still more preferably 95% or more (for example, 95 to 100%).
  • the interlayer sheet disclosed herein can be preferably used in a mode of being attached or laminated on an adherend (for example, an optical member) having a total light transmittance of a predetermined value or more.
  • a viscoelastic layer e.g. viscoelastic layer V 1 which is arranged in contact with the adherend, may be viscoelastic layer V 2 is in a form having a viscoelastic layer V 2.
  • the refractive index of the viscoelastic layer typically the pressure-sensitive adhesive layer
  • the viscoelastic layer typically, the pressure-sensitive adhesive layer
  • the viscoelastic layer is incident on the pressure-sensitive adhesive layer from the adherend side at an angle equal to or less than the critical angle.
  • the light to be emitted can be refracted to the front side to increase the front brightness.
  • the refractive index of the adherend may be, for example, 1.55 or less, 1.50 or less, 1.48 or less, 1.45 or less, less than 1.45, or, for example, 1. It can be .10 or higher, 1.20 or higher, 1.30 or higher, or 1.35 or higher.
  • the adherend having a relatively high refractive index with respect to the pressure-sensitive adhesive layer the light incident on the adherend from the pressure-sensitive adhesive layer side can be refracted to the front side to increase the front luminance.
  • the refractive index of the adherend may be, for example, 1.60 or more, 1.65 or more or 1.70 or more, and for example, 3.00 or less, 2.50 or less or 2.00 or less. Can be.
  • the refractive index of the adherend may be about 1.55 to 1.80, about 1.55 to 1.75, or about 1.60 to 1.70.
  • the refractive index of the adherend can be measured in the same manner as the refractive index of the pressure-sensitive adhesive.
  • the adherend may have any of the refractive indexes described above and any of the total light transmittances described above.
  • the effects of the techniques disclosed herein are particularly preferred in aspects of attachment or stacking to such adherends.
  • An example of a preferable application is an optical application. More specifically, it is disclosed herein as, for example, an optical adhesive sheet used for bonding optical members (for bonding optical members), manufacturing products using the above optical members (optical products), and the like.
  • the interlayer sheet to be used can be preferably used.
  • the optical member is not particularly limited, and examples thereof include members made of glass, acrylic resin, polycarbonate, polyethylene terephthalate, a metal thin film, and the like (for example, sheet-shaped, film-shaped, and plate-shaped members).
  • the "optical member” in this specification also includes a member (design film, decorative film, surface protective film, etc.) that plays a role of decoration and protection while maintaining the visibility of the display device and the input device.
  • Viscoelastic layer (preferably the adhesive layer of the interlayer sheet disclosed herein. Including for example, pressure-sensitive adhesive layer having a single layer structure made of viscoelastic layer V 1, or a viscoelastic layer V 1 and viscoelastic layer V 2
  • the adhesive layer having a laminated structure in which two or more adhesive layers are directly in contact with each other) is, for example, an optical of a light guide film, a diffusion film, a fluorescent film, a toning film, a prism sheet, a lenticular film, a microlens array film, or the like. It can be preferably used for bonding films. In these applications, thinning and improvement of light extraction efficiency are required from the viewpoint of miniaturization and high performance of optical members.
  • the scattering component can be reduced and the light transmittance can be improved by appropriately adjusting the refractive index of the pressure-sensitive adhesive so that the difference in the refractive index from the toning pigment is small.
  • the diffraction of light can be controlled by appropriately adjusting the refractive index of the pressure-sensitive adhesive, which can contribute to the improvement of brightness and / or viewing angle.
  • the interlayer sheet disclosed herein is preferably used in a manner of being attached to an adherend having a high refractive index (which may be a layer or a member having a high refractive index), and is used to cause interfacial reflection with the adherend. It can be suppressed.
  • an adherend having a high refractive index which may be a layer or a member having a high refractive index
  • the adhesion at the interface with the adherend is high.
  • the thickness of the pressure-sensitive adhesive layer is high, and for example, the surface smoothness of the pressure-sensitive adhesive surface is high.
  • the thickness of the adherend with a high refractive index is relatively small (for example, when it is 5 ⁇ m or less, 4 ⁇ m or less, or 2 ⁇ m or less), from the viewpoint of suppressing coloring and color unevenness due to the interference of reflected light, at the interface. Suppressing reflexes is especially meaningful.
  • an interlayer sheet disclosed herein because it comprises a viscoelastic layer V 1 of the high refractive index, bonded to the light-emitting layer of an optical semiconductor such as (e.g., mainly the light emitting layer of the high refractive constituted by an inorganic material) It can be preferably used in the attached embodiment.
  • an optical semiconductor such as (e.g., mainly the light emitting layer of the high refractive constituted by an inorganic material)
  • Interlayer sheet used in such manner as the viscoelastic layer V 1, it is preferable to provide a pressure-sensitive adhesive layer having a high refractive index.
  • the interlayer sheet is preferably low in color. This can also be advantageous from the viewpoint of suppressing unintentional coloring caused by the interlayer sheet.
  • Viscoelastic layer V 1 disclosed herein have since suitable high refractive index, a high refractive index of the lens (e.g., lens or constituted by the high refractive index resin, the surface layer made of a high refractive index resin Even if it is placed in contact with the lens), the difference in refractive index from the lens can be reduced. This is advantageous from the viewpoint of reducing the thickness of the lens and the product provided with the lens, and can also contribute to the suppression of aberration and the improvement of the Abbe number.
  • the mode in which the optical members are bonded using the interlayer sheet disclosed herein is not particularly limited, and examples thereof include (1) a mode in which the optical members are bonded to each other via the interlayer sheet disclosed here, and (2).
  • the optical member may be attached to a member other than the optical member via the interlayer sheet disclosed here, or (3) the interlayer sheet disclosed here includes the optical member.
  • the interlayer sheet may be attached to an optical member or a member other than the optical member.
  • the interlayer sheet in the form including the optical member may be, for example, an interlayer sheet in which the support is an optical member (for example, an optical film).
  • the interlayer sheet in the form of including the optical member as the support can also be grasped as an adhesive type optical member (for example, an adhesive type optical film).
  • an adhesive type optical member for example, an adhesive type optical film
  • the interlayer sheet disclosed here is a type of adhesive sheet having a support and the functional film is used as the support, the interlayer sheet disclosed here is the functional film. It can also be grasped as a "adhesive type functional film" having an adhesive layer disclosed herein on at least one side.
  • an optical laminate including the interlayer sheet disclosed here and a member (for example, a resin film such as an optical film) to which the interlayer sheet is attached is provided. ..
  • the member to which the interlayer sheet is attached may have the refractive index of the adherend material described above.
  • the difference (refractive index difference) between the refractive index of the member layers constituting the adhesive surface of the interlayer sheet (e.g. viscoelastic layer V 1), the refractive index of the adhesive layer and the adherend mentioned above It can be a difference. Since the members constituting the laminated body have been described as the above-mentioned members, materials, and adherends, the overlapping description will not be repeated.
  • An adhesive sheet containing an adhesive layer It has an adhesive surface composed of the above adhesive layer and has an adhesive surface.
  • the pressure-sensitive adhesive layer is a pressure-sensitive adhesive sheet having a refractive index of more than 1.570, a total light transmittance of 86% or more, and a haze value of 3.0% or less.
  • the additive (H RO ) according to any one of the above [11] to [13], which comprises at least one compound selected from the group consisting of an aromatic ring-containing compound and a heterocyclic ring-containing compound.
  • Adhesive composition [15] The pressure-sensitive adhesive composition according to any one of [11] to [14] above, wherein the additive (H RO) contains a compound having two or more aromatic rings in one molecule.
  • the additive ( HRO ) is a compound having two or more aromatic rings in one molecule. (I) Containing a structure in which two non-condensed aromatic rings are directly chemically bonded, and (ii) Containing a structure in which two non-condensed aromatic rings are condensed.
  • the content of the aromatic ring-containing monomer (m1) is more than 70% by weight and less than 100% by weight.
  • An interlayer sheet used by arranging between layers of a laminated body in optical applications Refractive index n 1 comprises a viscoelastic layer V 1 is 1.570 or more, and the total light transmittance is 86% or more; Haze value is 1.0% or less; and The storage modulus G'at 25 ° C. is 30 kPa to 700 kPa; An interlayer sheet that meets the requirements.
  • the interlayer sheet according to the above [24] which has a thickness of 5 ⁇ m or more.
  • the acrylic polymer A1 has a Tg (that is, Tg T ) based on the composition of the monomer component at ⁇ 35 ° C. and a Tg (that is, Tg m1 ) based on the composition of the aromatic ring-containing monomer at ⁇ 35 ° C.
  • the solution (50%) of the acrylic polymer A1 is diluted to 30% with ethyl acetate, and an isocyanurate compound of hexamethylene diisocyanate (manufactured by Toso Co., Ltd., trade name) is added to 334 parts (nonvolatile content 100 parts) of this solution as a cross-linking agent.
  • oligomer B After adding 3.5 parts of ⁇ -thioglycerol and 67 parts of methyl ethyl ketone as the transfer agent, nitrogen gas was flowed and nitrogen substitution was carried out for about 1 hour with stirring. Then, the flask was heated to 70 ° C. and reacted for 12 hours to obtain an acrylic oligomer (oligomer B) having a weight average molecular weight (Mw) of 4000 and a refractive index of 1.63.
  • Mw weight average molecular weight
  • the solution (50%) of the acrylic polymer A2 is diluted to 30% with ethyl acetate, and 20 parts of the oligomer B prepared above is added to 334 parts (100 parts of non-volatile content) of this solution, and hexamethylene diisocyanate as a cross-linking agent.
  • a solution (33%) of the acrylic polymer A3 is diluted to 30% with ethyl acetate, and an isocyanurate compound of hexamethylene diisocyanate as a cross-linking agent (manufactured by Tosoh Corporation, trade name " 10 parts (0.1 part of non-volatile content) of a 1% ethyl acetate solution of "Coronate HX" (trifunctional isocyanate compound) was added and mixed by stirring to prepare an acrylic pressure-sensitive adhesive composition C3.
  • an isocyanurate compound of hexamethylene diisocyanate as a cross-linking agent
  • Example 1 The acrylic pressure-sensitive adhesive composition C1 prepared above is applied to the silicone-treated surface of polyethylene terephthalate (PET) film R1 (thickness 50 ⁇ m) having a silicone treatment on one side, and heated at 130 ° C. for 2 minutes. A pressure-sensitive adhesive layer having a thickness of 25 ⁇ m was formed. A silicone-treated surface of PET film R2 (thickness 38 ⁇ m) having been treated with silicone on one side was bonded to the surface of the pressure-sensitive adhesive layer. In this way, both sides to obtain a PET film (release liner) R1, the form of the pressure-sensitive adhesive layer protected by R2 (the pressure-sensitive adhesive layer V 1).
  • PET polyethylene terephthalate
  • the peeling liner R2 is relatively light peeling as compared with the peeling liner R1. Further, the acrylic pressure-sensitive adhesive composition C3 prepared above is applied to the silicone-treated surface of PET film R1 (thickness 50 ⁇ m) having a silicone treatment on one side, and heated at 130 ° C. for 2 minutes to increase the thickness. to form a pressure-sensitive adhesive layer V 2 of 10 [mu] m. A silicone-treated surface of PET film R2 (thickness 38 ⁇ m) having been treated with silicone on one side was bonded to the surface of the pressure-sensitive adhesive layer. In this way, both sides obtain PET film (release liner) R1, the form of the pressure-sensitive adhesive layer protected by R2 (pressure-sensitive adhesive layer V 2).
  • Example 2 The pressure-sensitive adhesive layer V 1 is the same as in Example 1 except that the types of pressure-sensitive adhesive compositions used to form the pressure-sensitive adhesive layers V 1 and V 2 and the thickness of each pressure-sensitive adhesive layer are changed as shown in Table 1. An interlayer sheet (base-less double-sided adhesive sheet) having a two-layer structure of / V 2 was obtained.
  • the obtained interlayer sheet was sufficiently acclimatized to an environment of 23 ° C. and 50% RH, and then used for the following measurements and evaluations.
  • Total light transmittance and haze value Using a test piece in which the interlayer sheets according to each example were bonded to non-alkali glass (thickness 0.8 to 1.0 mm, total light transmittance 92%, haze 0.4%), under a measurement environment of 23 ° C. , Haze meter (manufactured by Murakami Color Technology Laboratory, trade name "HAZEMETER HM-150") was used to measure the total light transmittance and haze of the above test piece. The value obtained by subtracting the total light transmittance and haze of the non-alkali glass from the measured value was taken as the total light transmittance and haze value of the interlayer sheet. The results are shown in Table 1.
  • interlayer sheet of Examples 1-4 the refractive index n 1 is 1.570 or more, the storage elastic modulus G 'V1 is (25) comprises the following adhesive layer V 1 700 kPa, and the It showed high transparency in the interlayer sheet.
  • These interlayer sheets exhibited practical peel strength suitable for bonding between layers of optical members.
  • the adhesive layer (adhesive layer V 2 ) of Example 5 having a low refractive index and the adhesive layer (adhesive layer V 1 ) of Examples 3 and 4 having a high refractive index were combined.
  • the interlayer sheets of Examples 1 and 2 having the pressure-sensitive adhesive layer having a laminated structure an effect of improving the front brightness by 10% or more was observed as compared with the case where the interlayer sheet was not used.
  • the pressure-sensitive adhesive layer of the interlayer sheet has a single-layer structure, the effect of improving the front luminance by the interlayer sheet alone was not observed.
  • the effect of improving the front luminance can be exhibited in the laminated body with the member.
  • the interlayer sheet of Example 5 on a member having a higher refractive index (for example, a resin film), the effect of improving the front luminance can be exhibited in the laminated body with the member.
  • ⁇ Preparation of acrylic pressure-sensitive adhesive composition C4> In a four-necked flask equipped with a stirring blade, a thermometer, a nitrogen gas introduction tube and a cooler, 79 parts of POB-A, 20 parts of n-butyl acrylate (BA), and 1 part of 4HBA as monomer components, polymerization started. 0.2 part of AIBN as an agent and 100 parts of toluene as a polymerization solvent were charged, nitrogen gas was introduced while gently stirring, and the polymerization reaction was carried out for 6 hours while keeping the liquid temperature in the flask at around 60 ° C. to carry out an acrylic polymer. A solution of A4 (50%) was prepared. The Mw of this acrylic polymer A4 was 520,000.
  • the solution (50%) of the acrylic polymer A4 is diluted to 30% with ethyl acetate, and 10 parts (nonvolatile content) of 1% ethyl acetate solution of coronate HX as a cross-linking agent is added to 334 parts (nonvolatile content 100 parts) of this solution. 0.1 part), 2 parts of acetylacetone as a cross-linking retardant, and 1 part (0.01 part of non-volatile content) of 1% ethyl acetate solution of Nasem ferric iron as a cross-linking catalyst are added and mixed by stirring to form an acrylic pressure-sensitive adhesive.
  • Object C4 was prepared.
  • P2HA in the composition of the above-mentioned monomer component is phenoxydiethylene glycol acrylate (manufactured by Kyoeisha Chemical Co., Ltd., trade name "light acrylate P2HA", refractive index: 1.510, homopolymer Tg: -35 ° C.). show.
  • the Mw of this acrylic polymer A6 was 1 million.
  • Acrylic pressure-sensitive adhesive composition C8 Acrylic pressure-sensitive adhesive in the same manner as the preparation of the acrylic pressure-sensitive adhesive composition C7, except that 10 parts of POB-A was changed to 10 parts of 3-phenoxybenzyl alcohol (manufactured by Tokyo Chemical Industry Co., Ltd., refractive index 1.59).
  • the agent composition C8 was prepared.
  • Example 6 ⁇ Preparation of interlayer sheet> (Examples 6 to 10) Except that the kind of the pressure-sensitive adhesive composition used for forming the pressure-sensitive adhesive layer V 1, V 2 and the thickness of each adhesive layer were as shown in Table 3 in the same manner as Example 1, the adhesive layer V 1 / to obtain an interlayer sheet having a two-layer structure of the adhesive layer V 2 (substrate-less double-sided pressure-sensitive adhesive sheet).
  • interlayer sheet Examples 6-10 the refractive index n 1 is 1.570 or more, the storage elastic modulus G 'V1 is (25) comprises the following adhesive layer V 1 700 kPa, and the It showed high transparency in the interlayer sheet. These interlayer sheets exhibited practical peel strength suitable for bonding between layers of optical members.

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Abstract

Provided is an interlayer sheet that is disposed between layers of a laminate for optical use. The interlayer sheet comprises a viscoelastic layer V1 that has a refractive index n1 of 1.570 or more, and that has a storage elastic modulus G'V1 of 30-700 kPa at 25°C. The interlayer sheet has a total light transmittance of 86% or more, and a haze value of 1.0% or less.

Description

層間シート、剥離ライナー付き層間シートおよび光学積層体Interlayer sheet, interlayer sheet with release liner and optical laminate

　本発明は、層間シート、剥離ライナー付き層間シートおよび光学積層体に関する。
　本出願は、２０２０年３月２４日に出願された日本国特許出願２０２０－０５２４０８号、２０２０年９月３０日に出願された日本国特許出願２０２０－１６６４２９号、および２０２１年３月２３日に出願された日本国特許出願２０２１－０４９０６３号に基づく優先権を主張しており、それらの出願の全内容は本明細書中に参照として組み入れられている。 The present invention relates to an interlayer sheet, an interlayer sheet with a release liner, and an optical laminate.
This application is filed on March 24, 2020, Japanese Patent Application No. 2020-052408, Japanese Patent Application No. 2020-166429, filed on September 30, 2020, and March 23, 2021. Priority is claimed under the Japanese patent application 2021-049063 filed, and the entire contents of those applications are incorporated herein by reference.

　一般に、粘着剤（感圧接着剤ともいう。以下同じ。）は、室温付近の温度域において柔らかい固体（粘弾性体）の状態を呈し、圧力により簡単に被着体に接着する性質を有する。このような性質を活かして、粘着剤は、家電製品から自動車、各種機械、電気機器、電子機器等の様々な産業分野において、接合や固定、保護等の目的で広く利用されている。粘着剤の用途の一例として、液晶表示装置や有機ＥＬ表示装置等のような表示装置において、偏光フィルム、位相差フィルム、カバーウィンドウ部材、その他種々の光透過性部材と、他の部材とを接合する用途が挙げられる。光学部材用の粘着剤に関する技術文献として特許文献１、２が挙げられる。 Generally, an adhesive (also referred to as a pressure-sensitive adhesive; the same applies hereinafter) exhibits a soft solid (viscous elastic body) state in a temperature range near room temperature, and has a property of easily adhering to an adherend by pressure. Taking advantage of these properties, adhesives are widely used for the purpose of joining, fixing, protecting, etc. in various industrial fields such as home appliances, automobiles, various machines, electric devices, and electronic devices. As an example of the use of the pressure-sensitive adhesive, in a display device such as a liquid crystal display device or an organic EL display device, a polarizing film, a retardation film, a cover window member, and various other light-transmitting members are joined to another member. Uses to be mentioned. Patent Documents 1 and 2 are listed as technical documents relating to adhesives for optical members.

日本国特許出願公開２０１４－１６９３８２号公報Japanese Patent Application Publication No. 2014-169382 日本国特許出願公開２０１７－１２８７３２号公報Japanese Patent Application Publication No. 2017-128732

　特許文献１、２は、モノマー単位として芳香環を複数有するモノマーを含有する（メタ）アクリル酸エステル重合体を主成分とする粘着剤組成物、および該粘着剤組成物を架橋してなる粘着剤を提案しているが、１．５７０以上の屈折率と柔軟性とを兼ね備えた具体的な粘着剤を開示してはいない。一方、高屈折率の無機材料からなる粒子（例えば、酸化ジルコニウム粒子や酸化チタン粒子等の無機粒子）を樹脂に配合して屈折率を高める技術も知られているが、無機粒子が配合された粘着剤は屈折率と粘着特性（例えば剥離強度、柔軟性等）とがトレードオフの関係にあるため、粘着剤の分野への適用は難しい。特に光学用途向けの粘着剤では、無機粒子の配合にあたっては光学特性（例えば全光線透過率、ヘイズ等）への影響にも配慮する必要がある。例えば、光学用途において積層体の層間に配置して用いられる層間シートの屈折率向上を検討するにあたっては、該層間シートに隣接する部材に対して適切な密着性や変形追従性を発揮し得る柔軟性および高い透明性とのバランスをとりつつ高屈折率化することが求められる。 Patent Documents 1 and 2 describe a pressure-sensitive adhesive composition containing a (meth) acrylic acid ester polymer containing a monomer having a plurality of aromatic rings as a monomer unit as a main component, and a pressure-sensitive adhesive obtained by cross-linking the pressure-sensitive adhesive composition. However, it does not disclose a specific adhesive having a refractive index of 1.570 or more and flexibility. On the other hand, there is also known a technique of blending particles made of an inorganic material having a high refractive index (for example, inorganic particles such as zirconium oxide particles and titanium oxide particles) into a resin to increase the refractive index, but inorganic particles are blended. Since the refractive index and the adhesive properties (for example, peel strength, flexibility, etc.) of the adhesive have a trade-off relationship, it is difficult to apply the adhesive to the field of the adhesive. In particular, in adhesives for optical applications, it is necessary to consider the influence on optical properties (for example, total light transmittance, haze, etc.) when blending inorganic particles. For example, in examining the improvement of the refractive index of an interlayer sheet used by arranging it between layers of a laminated body in an optical application, flexibility capable of exhibiting appropriate adhesion and deformation followability to a member adjacent to the interlayer sheet. It is required to increase the refractive index while balancing the properties and high transparency.

　本発明は、上記の状況に鑑みて創出されたものであり、隣接する部材への密着や追従に適した柔軟性を示し、かつ高屈折率および高透明性を兼ね備えた層間シートを提供することを目的とする、本発明の他の目的は、上記層間シートを含む剥離ライナー付き層間シートを提供することである。関連する他の目的は、上記層間シートを構成要素として含む光学積層体を提供することである。 The present invention has been created in view of the above circumstances, and provides an interlayer sheet that exhibits flexibility suitable for adhering to and following adjacent members, and has a high refractive index and high transparency. Another object of the present invention for the purpose of the present invention is to provide an interlayer sheet with a release liner containing the above-mentioned interlayer sheet. Another related object is to provide an optical laminate that includes the interlayer sheet as a component.

　この明細書によると、光学用途において積層体の層間に配置して用いられる層間シートが提供される。上記層間シートは、屈折率ｎ１が１．５７０以上である粘弾性層Ｖ１を含む。上記層間シートは、全光線透過率が８６％以上であり、ヘイズ値が１．０％以下であり、かつ２５℃における貯蔵弾性率Ｇ’ V1（以下、「貯蔵弾性率Ｇ’V1(25)」と表記することがある。）が３０ｋＰａ～７００ｋＰａである。上記層間シートは、高屈折率でありながら貯蔵弾性率Ｇ’ V1(25)が一定以下に抑制された粘弾性層Ｖ１を含み、かつ高透明であることから、光学用途向けの層間シートとして有用である。また、上記層間シートはあらかじめシート形状に成形されているので、所望の箇所に容易に配置することができる。 According to this specification, an interlayer sheet is provided which is arranged and used between layers of a laminated body in an optical application. The interlayer sheet has a refractive index n 1 includes a viscoelastic layer V 1 is 1.570 or more. The interlayer sheet is a total light transmittance of 86% or more, haze of 1.0% or less, and a storage modulus at 25 ℃ G 'V1 (hereinafter, "storage elastic modulus G' V1 (25) ”) Is 30 kPa to 700 kPa. The interlayer sheet, since high while the refractive index storage modulus G 'V1 (25) comprises a viscoelastic layer V 1 that is suppressed below a predetermined level, and a high transparency, as an interlayer sheet for optical applications It is useful. Further, since the interlayer sheet is preformed into a sheet shape, it can be easily arranged at a desired position.

　いくつかの態様では、上記粘弾性層の厚さは５μｍ以上である。このような厚さを有する粘弾性層は、隣接する部材表面に存在し得る凹凸を吸収することで該部材に密着性よく積層しやすいので好ましい。 In some embodiments, the thickness of the viscoelastic layer is 5 μm or more. A viscoelastic layer having such a thickness is preferable because it absorbs irregularities that may exist on the surface of an adjacent member and is easily laminated on the member with good adhesion.

　いくつかの態様に係る層間シートは、上記粘弾性層Ｖ１に積層された粘弾性層Ｖ２をさらに含む。ここで、上記粘弾性層Ｖ２の２５℃における貯蔵弾性率Ｇ’V2（以下、「貯蔵弾性率Ｇ’V2(25)」と表記することがある。）は、上記粘弾性層Ｖ１の２５℃における貯蔵弾性率Ｇ’V1より低い。このような構成の層間シートは、粘弾性層Ｖ２の寄与により、より柔軟性に優れたものとなり得る。 Interlayer sheet according to some embodiments, further comprises a viscoelastic layer V 2 which is laminated on the viscoelastic layer V 1. Here, the storage elastic modulus at 25 ° C. of the viscoelastic layer V 2 G 'V2 (hereinafter, "storage modulus G' may be referred to as V2 (25)".) Is the viscoelastic layer V 1 lower than the storage modulus G 'V1 at 25 ° C.. Such configuration interlayer sheet is due to the contribution of the viscoelastic layer V 2, it can be excellent in more flexible.

　いくつかの態様では、上記粘弾性層Ｖ２の屈折率ｎ２は、上記粘弾性層Ｖ１の屈折率ｎ１より低い。かかる構成を有する層間シートによると、粘弾性層Ｖ１，Ｖ２の屈折率差を利用して、該層間シートを透過する光の挙動を制御することができる。 In some embodiments, the refractive index n 2 of the viscoelastic layer V 2 is lower than the refractive index n 1 of the viscoelastic layer V 1. According to the interlayer sheet having such a configuration, by utilizing the refractive index difference of the viscoelastic layer V 1, V 2, it is possible to control the behavior of light transmitted through the interlayer sheet.

　また、この明細書によると、ここに開示されるいずれかの層間シートと、上記層間シートの少なくとも一方の表面を覆う剥離ライナーと、を含む剥離ライナー付き層間シートが提供される。ここに開示される層間シートは、このように少なくとも一方の表面が剥離ライナーで保護された剥離ライナー付き層間シートの形態で製造、保管、流通、加工等を行い、隣接する部材との積層前に上記剥離ライナーを剥がす態様で好ましく用いられ得る。 Further, according to this specification, an interlayer sheet with a release liner including any of the interlayer sheets disclosed herein and a release liner covering at least one surface of the interlayer sheet is provided. The interlayer sheet disclosed herein is manufactured, stored, distributed, processed, etc. in the form of an interlayer sheet with a release liner whose at least one surface is protected by a release liner in this way, and before being laminated with an adjacent member. It can be preferably used in the mode of peeling off the release liner.

　また、この明細書によると、ここに開示されるいずれかの層間シートと、上記層間シートに積層された樹脂フィルムと、を含む光学積層体が提供される。かかる光学積層体において、ここに開示される層間シートが高屈折率および高透明性と柔軟性とを兼ね備えることによる利点が好ましく発揮され得る。 Further, according to this specification, an optical laminate including any of the interlayer sheets disclosed herein and a resin film laminated on the interlayer sheet is provided. In such an optical laminate, the advantages of the interlayer sheet disclosed herein having high refractive index, high transparency and flexibility can be preferably exhibited.

　なお、本明細書に記載された各要素を適宜組み合わせたものも、本件特許出願によって特許による保護を求める発明の範囲に含まれ得る。 It should be noted that an appropriate combination of the elements described in the present specification may be included in the scope of the invention for which protection by the patent is sought by the present patent application.

一実施形態に係る層間シートの構成を模式的に示す断面図である。It is sectional drawing which shows typically the structure of the interlayer sheet which concerns on one Embodiment. 他の一実施形態に係る層間シートの構成を模式的に示す断面図である。It is sectional drawing which shows typically the structure of the interlayer sheet which concerns on another embodiment. 一実施形態に係る層間シートを含む光学積層体を模式的に示す断面図である。It is sectional drawing which shows typically the optical laminated body including the interlayer sheet which concerns on one Embodiment.

　以下、本発明の好適な実施形態を説明する。本明細書において特に言及している事項以外の事柄であって本発明の実施に必要な事柄は、本明細書に記載された発明の実施についての教示と出願時の技術常識とに基づいて当業者に理解され得る。本発明は、本明細書に開示されている内容と当該分野における技術常識とに基づいて実施することができる。
　なお、以下の図面において、同じ作用を奏する部材・部位には同じ符号を付して説明することがあり、重複する説明は省略または簡略化することがある。また、図面に記載の実施形態は、本発明を明瞭に説明するために模式化されており、実際に提供される製品のサイズや縮尺を必ずしも正確に表したものではない。 Hereinafter, preferred embodiments of the present invention will be described. Matters other than those specifically mentioned in the present specification and necessary for the practice of the present invention are based on the teachings regarding the practice of the invention described in the present specification and the common general knowledge at the time of filing. Can be understood by those skilled in the art. The present invention can be carried out based on the contents disclosed in the present specification and common general technical knowledge in the art.
In the following drawings, members / parts having the same function may be described with the same reference numerals, and duplicate description may be omitted or simplified. Further, the embodiments described in the drawings are modeled for clearly explaining the present invention, and do not necessarily accurately represent the size and scale of the actually provided product.

　この明細書において、自発光素子とは、流れる電流値によって発光輝度を制御することが可能な発光素子を意味する。自発光素子は、単一体で構成されていてもよく、集合体で構成されていてもよい。自発光素子の具体例には、発光ダイオード（ＬＥＤ）および有機ＥＬが含まれるが、これらに限定されない。この明細書において発光装置に言及する場合、該発光装置は、このような自発光素子を構成要素として含み得る。上記発光装置の例には、照明として利用される光源モジュール装置（例えば、面状発光体モジュール）や、画素を形成した表示装置が含まれるが、これらに限定されない。 In this specification, the self-luminous element means a light emitting element capable of controlling the emission brightness by the flowing current value. The self-luminous element may be composed of a single body or an aggregate. Specific examples of the self-luminous element include, but are not limited to, a light emitting diode (LED) and an organic EL. When referring to a light emitting device in the present specification, the light emitting device may include such a self-luminous element as a component. Examples of the light emitting device include, but are not limited to, a light source module device used as lighting (for example, a planar light emitting body module) and a display device having pixels formed therein.

　この明細書により、光学用途において積層体の層間に配置して用いられる層間シートが提供される。上記層間シートは、少なくとも粘弾性層Ｖ１を含む。上記層間シートは、上記粘弾性層Ｖ１に積層された粘弾性層Ｖ２をさらに含んでいてもよい。粘弾性層Ｖ１、Ｖ２の一方または両方は、典型的には、粘着剤により構成された粘着剤層である。かかる態様の層間シートは、粘着剤層を有する粘着シートとして把握され得る。以下、層間シートを粘着シートと、粘弾性層を粘着剤層と、粘弾性材料を粘着剤と、粘弾性層の表面を粘着面と、それぞれ言い換えることがある。また、ここに開示される層間シートの粘弾性層が積層される部材を、該層間シート（粘着シート）の被着体ということがある。いくつかの態様において、上記層間シートは、粘着剤層Ｖ１により構成された粘着面を有することが好ましい。 This specification provides an interlayer sheet that is arranged and used between layers of a laminate in optical applications. The interlayer sheet includes at least a viscoelastic layer V 1. The interlayer sheet may further include a viscoelastic layer V 2 which is laminated on the viscoelastic layer V 1. One or both of the viscoelastic layers V 1 and V 2 is typically a pressure-sensitive adhesive layer composed of a pressure-sensitive adhesive. The interlayer sheet of such an embodiment can be grasped as a pressure-sensitive adhesive sheet having a pressure-sensitive adhesive layer. Hereinafter, the interlayer sheet may be paraphrased as an adhesive sheet, the viscoelastic layer as an adhesive layer, the viscoelastic material as an adhesive, and the surface of the viscoelastic layer as an adhesive surface. Further, the member on which the viscoelastic layers of the interlayer sheets disclosed herein are laminated may be referred to as an adherend of the interlayer sheet (adhesive sheet). In some embodiments, the interlayer sheet preferably has an adhesive surface configured by an adhesive layer V 1.

＜層間シートの構成例＞
　ここに開示される層間シートは、非剥離性の基材（支持基材）の片面または両面に粘着剤層（例えば、粘弾性層Ｖ１からなる単層構造の粘着剤層、または、粘弾性層Ｖ１および粘弾性層Ｖ２を含む二以上の粘着剤層が直接接して積層した積層構造の粘着剤層）を有する形態の基材付き粘着シートの形態であってもよく、上記粘着剤層が剥離ライナーに保持された形態等の基材レスの粘着シート（すなわち、非剥離性の基材を有しない粘着シート。典型的には粘着剤層からなる粘着シート）の形態であってもよい。ここでいう粘着シートの概念には、粘着テープ、粘着ラベル、粘着フィルム等と称されるものが包含され得る。ここに開示される粘着シートは、ロール状であってもよく、枚葉状であってもよい。あるいは、さらに種々の形状に加工された形態の粘着シートであってもよい。 <Structure example of interlayer sheet>
Interlayer sheet disclosed herein, one or both surfaces an adhesive layer (for example, pressure-sensitive adhesive layer having a single layer structure made of viscoelastic layer V 1 of the non-releasable substrate (support substrate), or viscoelastic It may be in the form of an adhesive sheet with a base material having a laminated structure (adhesive layer having a laminated structure in which two or more adhesive layers including a layer V 1 and a viscoelastic layer V 2 are directly in contact with each other). Even in the form of a base material-less pressure-sensitive adhesive sheet (that is, a pressure-sensitive adhesive sheet having no non-peeling base material, typically a pressure-sensitive adhesive sheet composed of a pressure-sensitive adhesive layer) such that the layer is held by a release liner. good. The concept of the pressure-sensitive adhesive sheet as used herein may include what is called an pressure-sensitive adhesive tape, a pressure-sensitive adhesive label, a pressure-sensitive adhesive film, or the like. The pressure-sensitive adhesive sheet disclosed herein may be in the form of a roll or in the form of a single leaf. Alternatively, it may be an adhesive sheet in a form further processed into various shapes.

　ここに開示される層間シートの一構成例を図１に示す。この層間シート（粘着シート）１は、第１の表面１０Ａが被着体への貼付面（粘着面）となっている粘着剤層１０と、粘着剤層１０の第２の表面１０Ｂに積層された支持基材２０と、を含む片面接着性の粘着シート（片面粘着シート）として構成されている。粘着剤層１０の第２の表面１０Ｂは、支持基材２０の第１面（非剥離性の表面）２０Ａに接合している。支持基材２０としては、例えばポリエステルフィルム等のプラスチックフィルムが用いられ得る。支持基材２０は、例えば偏光板等の光学フィルムであってもよい。使用前（被着体への貼付け前）の粘着シート１は、例えば図１に示すように、粘着面１０Ａが、少なくとも該粘着剤層側が剥離性表面（剥離面）となっている剥離ライナー３０で保護された、剥離ライナー付き粘着シート５０の形態であり得る。あるいは、支持基材２０の第２面２０Ｂ（第１面２０Ａとは反対側の表面であり、背面ともいう。）が剥離面となっており、この第２面２０Ｂに粘着面１０Ａが当接するように巻回または積層されることで粘着面１０Ａが保護された形態であってもよい。粘着剤層１０は、図１に示すように粘弾性層Ｖ１からなる単層構造であってもよく、組成の異なる２以上のサブ粘着剤層（例えば、粘着面１０Ａを構成する粘弾性層Ｖ１と、支持基材２０側に配置された粘弾性層Ｖ２との２つのサブ粘着剤層）が直接接して（すなわち、非粘着性材料の層によって隔てられることなく）積層した積層構造であってもよい。 An example of the configuration of the interlayer sheet disclosed here is shown in FIG. The interlayer sheet (adhesive sheet) 1 is laminated on the pressure-sensitive adhesive layer 10 in which the first surface 10A is the surface to be attached to the adherend (adhesive surface) and the second surface 10B of the pressure-sensitive adhesive layer 10. It is configured as a single-sided adhesive adhesive sheet (single-sided adhesive sheet) containing the support base material 20 and the support base material 20. The second surface 10B of the pressure-sensitive adhesive layer 10 is bonded to the first surface (non-peelable surface) 20A of the support base material 20. As the support base material 20, for example, a plastic film such as a polyester film can be used. The support base material 20 may be, for example, an optical film such as a polarizing plate. The pressure-sensitive adhesive sheet 1 before use (before sticking to the adherend) has a peel-off liner 30 in which the pressure-sensitive adhesive surface 10A has at least a peelable surface (peeling surface) on the pressure-sensitive adhesive layer side, as shown in FIG. 1, for example. It may be in the form of an adhesive sheet 50 with a release liner protected by. Alternatively, the second surface 20B of the support base material 20 (the surface opposite to the first surface 20A and also referred to as the back surface) is a peeling surface, and the adhesive surface 10A abuts on the second surface 20B. The adhesive surface 10A may be protected by being wound or laminated as described above. Adhesive layer 10 may be a single layer structure made of viscoelastic layer V 1 as shown in FIG. 1, 2 or more sub-sensitive adhesive layer having a different composition (e.g., viscoelastic layer constituting the adhesive surface 10A A laminated structure in which V 1 and two sub-adhesive layers of a viscoelastic layer V 2 arranged on the support base material 20 side are directly in contact with each other (that is, without being separated by a layer of a non-adhesive material). It may be.

　ここに開示される層間シートは、粘着剤層からなる基材レス両面粘着シートの形態であってもよい。図２に示すように、基材レス両面粘着シート２は、使用前においては、粘着剤層１０の第１の表面（第１粘着面）１０Ａおよび第２の表面（第２粘着面）１０Ｂが、少なくとも該粘着剤層側が剥離性表面（剥離面）となっている剥離ライナー３１，３２で保護された形態であり得る。あるいは、剥離ライナー３１の背面（粘着剤側とは反対側の表面）が剥離面となっており、剥離ライナー３１の背面に粘着面１０Ｂが当接するように巻回または積層されることで粘着面１０Ａ，１０Ｂが保護された形態であってもよい。このような基材レス両面粘着シートは、例えば、第１粘着面および第２粘着面のうち少なくとも一方の粘着面に基材（好ましくは光透過性基材であり、例えば光学フィルム等の光学部材であり得る。）を接合して使用され得る。
　図２に示す基材レス両面粘着シート２を構成する粘着剤層１０は、組成の異なる２つのサブ粘着剤層が直接接して積層した積層構造を有する。粘着剤層１０は、具体的には、第１粘弾性層（第１粘着剤層、粘弾性層Ｖ１）１１と、第２粘弾性層（第２粘着剤層、粘弾性層Ｖ２）１２と、からなる積層構造（二層構造）である。あるいは、ここに開示される層間シートは、単層構造の粘着剤層（粘弾性層Ｖ１）からなる基材レス両面粘着シートの形態であってもよい。このような積層構造または単層構造の基材レス両面粘着シートの形態の層間シートは、例えば第１粘着面および第２粘着面にそれぞれ光学部材が積層された光学積層体の構成要素として用いられ得る。 The interlayer sheet disclosed herein may be in the form of a base material-less double-sided pressure-sensitive adhesive sheet composed of a pressure-sensitive adhesive layer. As shown in FIG. 2, the base material-less double-sided adhesive sheet 2 has a first surface (first adhesive surface) 10A and a second surface (second adhesive surface) 10B of the adhesive layer 10 before use. , At least the adhesive layer side may be a form protected by a release liner 31 or 32 having a releaseable surface (release surface). Alternatively, the back surface of the release liner 31 (the surface opposite to the adhesive side) is the release surface, and the adhesive surface is wound or laminated so that the adhesive surface 10B abuts on the back surface of the release liner 31. 10A and 10B may be in a protected form. Such a base material-less double-sided pressure-sensitive adhesive sheet is, for example, a base material (preferably a light-transmitting base material, and is an optical member such as an optical film) on at least one of the first pressure-sensitive adhesive surface and the second pressure-sensitive adhesive surface. Can be used by joining.
The pressure-sensitive adhesive layer 10 constituting the base-less double-sided pressure-sensitive adhesive sheet 2 shown in FIG. 2 has a laminated structure in which two sub- pressure-sensitive adhesive layers having different compositions are directly in contact with each other and laminated. Specifically, the pressure-sensitive adhesive layer 10 includes a first viscoelastic layer (first pressure-sensitive adhesive layer, viscoelastic layer V 1 ) 11 and a second viscoelastic layer (second pressure-sensitive adhesive layer, viscoelastic layer V 2 ). It is a laminated structure (two-layer structure) composed of 12 and. Alternatively, the interlayer sheet disclosed herein, the pressure-sensitive adhesive layer having a single layer structure or may be in the form of a substrate-less double-sided pressure-sensitive adhesive sheet consisting of (viscoelastic layer V 1). The interlayer sheet in the form of a base material-less double-sided adhesive sheet having such a laminated structure or a single-layer structure is used, for example, as a component of an optical laminated body in which optical members are laminated on the first adhesive surface and the second adhesive surface, respectively. obtain.

　ここに開示される層間シートは、少なくとも一方の表面に光学部材が接合された光学積層体の構成要素であり得る。例えば、図１に示す層間シート１は、図３に示すように、粘着剤層１０の第１の表面１０Ａに光学部材７０が積層された光学積層体１００の構成要素であり得る。上記光学部材は、例えば、ガラス板、樹脂フィルム、金属板等であり得る。層間シート１は、光学部材７０と、図示しない第２光学部材との間に配置されることで光学積層体の構成要素となっていてもよい。また、図１に示す層間シート１において、支持基材２０が光学フィルム等の光学部材である場合、該層間シート１は、粘着剤層１０の第２の表面１０Ｂに光学部材が積層された光学積層体として把握され得る。 The interlayer sheet disclosed here can be a component of an optical laminate in which an optical member is bonded to at least one surface. For example, the interlayer sheet 1 shown in FIG. 1 can be a component of the optical laminate 100 in which the optical member 70 is laminated on the first surface 10A of the pressure-sensitive adhesive layer 10, as shown in FIG. The optical member may be, for example, a glass plate, a resin film, a metal plate, or the like. The interlayer sheet 1 may be a component of an optical laminate by being arranged between the optical member 70 and a second optical member (not shown). Further, in the interlayer sheet 1 shown in FIG. 1, when the supporting base material 20 is an optical member such as an optical film, the interlayer sheet 1 is an optical structure in which the optical member is laminated on the second surface 10B of the pressure-sensitive adhesive layer 10. It can be grasped as a laminated body.

　また、ここに開示される層間シートは、特に図示しないが、非剥離性の第１面および第２面を有する支持基材を備え、上記第１面に第１粘着剤層が固定的に積層され、上記第２面に第２粘着剤層が固定的に積層された、基材付きの両面接着性粘着シート（基材付き両面粘着シート）の形態であってもよい。このような基材付き両面粘着シートの構成例として、図１に示す片面粘着シート１において、支持基材２０の第２面２０Ｂが非剥離性の表面であって該第２面２０Ｂ上に第２粘着剤層が設けられ、上記第２粘着剤層の第２の表面が支持基材２０の第２面２０Ｂに接合し、上記第２粘着剤層の第１の表面（第２の表面とは反対側の表面）が基材付き両面粘着シートの第２粘着面となっている形態が挙げられる。第２粘着剤層を構成する粘着剤の組成は、第１粘着剤層を構成する粘着剤の組成と同様であってもよく、異なっていてもよい。このような基材付き両面粘着シートの形態の層間シートは、例えば第１粘着面および第２粘着面にそれぞれ光学部材が積層された光学積層体の構成要素として用いられ得る。使用前の基材付き両面粘着シートは、上述した基材レス両面粘着シートと同様に、第１粘着面および第２粘着面が剥離ライナーによって保護された形態であり得る。 Further, although not particularly shown, the interlayer sheet disclosed here includes a support base material having a non-peelable first surface and a second surface, and a first pressure-sensitive adhesive layer is fixedly laminated on the first surface. It may be in the form of a double-sided adhesive pressure-sensitive adhesive sheet with a base material (double-sided pressure-sensitive adhesive sheet with a base material) in which a second pressure-sensitive adhesive layer is fixedly laminated on the second surface. As a configuration example of such a double-sided pressure-sensitive adhesive sheet with a base material, in the single-sided pressure-sensitive adhesive sheet 1 shown in FIG. The two pressure-sensitive adhesive layers are provided, and the second surface of the second pressure-sensitive adhesive layer is bonded to the second surface 20B of the support base material 20, and the first surface (with the second surface) of the second pressure-sensitive adhesive layer is bonded. The surface on the opposite side) is the second adhesive surface of the double-sided adhesive sheet with a base material. The composition of the pressure-sensitive adhesive constituting the second pressure-sensitive adhesive layer may be the same as or different from the composition of the pressure-sensitive adhesive constituting the first pressure-sensitive adhesive layer. Such an interlayer sheet in the form of a double-sided pressure-sensitive adhesive sheet with a base material can be used, for example, as a component of an optical laminate in which optical members are laminated on the first pressure-sensitive adhesive surface and the second pressure-sensitive adhesive surface, respectively. The double-sided pressure-sensitive adhesive sheet with a base material before use may be in a form in which the first pressure-sensitive adhesive surface and the second pressure-sensitive adhesive surface are protected by a release liner, similarly to the above-mentioned base material-less double-sided pressure-sensitive adhesive sheet.

＜層間シートの特性＞
　（屈折率）
　ここに開示される層間シートは、屈折率ｎ１が１．５７０以上である粘弾性層（粘着剤層）Ｖ１を有する。このような粘弾性層Ｖ１は、例えば、屈折率が１．５７０以上の粘着剤（粘弾性材料）によって該粘弾性層の少なくとも一方の表面（粘着面）を構成することにより実現することができる。ここに開示される技術によると、屈折率が１．５７０以上である粘着剤層Ｖ１、該粘着剤層Ｖ１を形成することのできる粘着剤組成物、および上記粘着剤層Ｖ１を含む層間シートが提供され得る。 <Characteristics of interlayer sheet>
(Refractive index)
The interlayer sheet disclosed herein has a viscoelastic layer (adhesive layer) V 1 having a refractive index n 1 of 1.570 or more. Such a viscoelastic layer V 1 can be realized, for example, by forming at least one surface (adhesive surface) of the viscoelastic layer with an adhesive (viscoelastic material) having a refractive index of 1.570 or more. can. Including According to the art disclosed herein, the pressure-sensitive adhesive layer V 1 a refractive index of 1.570 or more, the pressure-sensitive adhesive composition capable of forming a PSA layer V 1, and the pressure-sensitive adhesive layer V 1 Interlayer sheets may be provided.

　なお、本明細書において粘着剤（粘弾性材料）の屈折率とは、該粘着剤の表面（粘着面）の屈折率をいう。粘着剤の屈折率は、市販の屈折率測定装置（アッベ屈折率計）を用いて、測定波長５８９ｎｍ、測定温度２５℃の条件で測定することができる。アッベ屈折率計としては、例えばＡＴＡＧＯ社製の型式「ＤＲ－Ｍ４」またはその相当品が用いられる。測定サンプルとしては、評価対象の粘着剤からなる粘着剤層を用いることができる。粘着剤の屈折率は、具体的には、後述の実施例に記載の方法で測定することができる。粘着剤の屈折率は、例えば、該粘着剤の組成（例えば、ベースポリマーを構成するモノマー成分の組成、必要に応じて用いられ得る添加剤等）によって調節することができる。 In the present specification, the refractive index of the pressure-sensitive adhesive (viscoelastic material) means the refractive index of the surface (adhesive surface) of the pressure-sensitive adhesive. The refractive index of the pressure-sensitive adhesive can be measured using a commercially available refractive index measuring device (Abbe refractive index meter) under the conditions of a measurement wavelength of 589 nm and a measurement temperature of 25 ° C. As the Abbe refractive index meter, for example, a model "DR-M4" manufactured by ATAGO or an equivalent product thereof is used. As the measurement sample, a pressure-sensitive adhesive layer made of the pressure-sensitive adhesive to be evaluated can be used. Specifically, the refractive index of the pressure-sensitive adhesive can be measured by the method described in Examples described later. The refractive index of the pressure-sensitive adhesive can be adjusted, for example, by the composition of the pressure-sensitive adhesive (for example, the composition of the monomer components constituting the base polymer, additives that can be used if necessary, etc.).

　いくつかの態様において、粘着剤層Ｖ１の屈折率は、１．５７０超であることが有利であり、好ましくは１．５８０以上であり、より好ましくは１．５８５以上であり、さらに好ましくは１．５９０以上（例えば１．５９５以上）であり得る。かかる屈折率を有する粘着剤層Ｖ１によると、該粘着剤層Ｖ１とこれに隣接する層（層間シートに含まれる他の粘弾性層（例えば粘着剤層Ｖ２）でもよく、粘着剤層Ｖ１が積層される被着体でもよい。）との相対的な屈折率の関係を利用して、粘着剤層Ｖ１を透過する光の挙動を効果的に制御することができる。ここに開示される技術のいくつかの態様において、粘着剤層Ｖ１の屈折率は、例えば１．６００以上または１．６００超、１．６０５以上または１．６０５超、あるいは１．６１０以上または１．６１０超であり得る。粘着剤層Ｖ１の屈折率の好ましい上限は、隣接する層の屈折率等に応じて異なり得るので特定の範囲に限定されない。いくつかの態様において、粘着特性や透明性とのバランスを考慮して、粘着剤層Ｖ１の屈折率は、例えば１．７００以下であってよく、１．６７０以下でもよく、１．６５０以下でもよい。 In some embodiments, the refractive index of the adhesive layer V 1 was, is advantageously a 1.570 greater, preferably 1.580 or more, more preferably 1.585 or more, more preferably It can be 1.590 or higher (eg, 1.595 or higher). A PSA layer V 1 having such refractive index, other viscoelastic layer in the layer (interlayer sheet adjacent thereto with the pressure-sensitive adhesive layer V 1 (e.g., pressure-sensitive adhesive layer V 2) Even better, the pressure-sensitive adhesive layer The behavior of the light transmitted through the pressure-sensitive adhesive layer V 1 can be effectively controlled by utilizing the relationship of the refractive index with the adherend on which V 1 is laminated. In some embodiments of the technology disclosed herein, the refractive index of the adhesive layer V 1 was, for example, 1.600 or more or 1.600 greater than 1.605 or more or 1.605 greater, or 1.610 or more, or It can be greater than 1.610. The preferable upper limit of the refractive index of the pressure-sensitive adhesive layer V 1 is not limited to a specific range because it may differ depending on the refractive index of the adjacent layer and the like. In some embodiments, the refractive index of the pressure-sensitive adhesive layer V 1 may be, for example, 1.700 or less, 1.670 or less, or 1.650 or less in consideration of the balance with the adhesive properties and transparency. But it may be.

　ここに開示される層間シートが、一方の面が第１粘着面となっており、他方の面が第２粘着面となっている両面粘着シート（基材レス両面粘着シートおよび基材付き両面粘着シートの両方を包含する。特に断りのない限り以下同じ。）の形態であって、上記第１粘着面が粘着剤層Ｖ１により構成されている場合、該粘着剤層は、少なくも第１粘着面が上述したいずれかの屈折率を満たすことが好ましい。第２粘着面の屈折率は特に制限されない。 The interlayer sheet disclosed herein is a double-sided adhesive sheet having one surface as a first adhesive surface and the other surface as a second adhesive surface (base-less double-sided adhesive sheet and double-sided adhesive with a base material). encompasses both sheets. in particular in the form of the same.) the following unless otherwise stated, the case where the first adhesive surface is formed by a pressure-sensitive adhesive layer V 1, the pressure-sensitive adhesive layer, at least first It is preferable that the adhesive surface satisfies any of the above-mentioned refractive coefficients. The refractive index of the second adhesive surface is not particularly limited.

　いくつかの態様において、第２粘着面の屈折率ｎ２は、第１粘着面の屈折率ｎ１と概ね同程度であり得る。より具体的には、両粘着面の屈折率の差の絶対値、すなわち｜ｎ１－ｎ２｜は、例えば０．０５未満、または０．０３未満、または０．０１未満であり得る。｜ｎ１－ｎ２｜の下限は、０．００でもよく、０．００より大でもよい。両粘着面の屈折率の相対関係は、ｎ１＞ｎ２でもよく、ｎ１＜ｎ２でもよく、ｎ１＝ｎ２でもよい。 In some embodiments, the refractive index n 2 of the second adhesive surface can be approximately comparable to the refractive index n 1 of the first adhesive surface. More specifically, the absolute value of the difference in refractive index between the two adhesive surfaces, that is, | n 1- n 2 |, can be, for example, less than 0.05, less than 0.03, or less than 0.01. The lower limit of | n 1 − n 2 | may be 0.00 or greater than 0.00. The relative relationship between the refractive indexes of both adhesive surfaces may be n 1 > n 2 , n 1 <n 2 , or n 1 = n 2 .

　他のいくつかの態様において、層間シートの第１粘着面の屈折率ｎ１と第２粘着面の屈折率ｎ２との差、すなわちｎ１－ｎ２は、例えば０．００より大であってよく、０．０１以上でもよく、０．０２以上であることが好ましく、０．０３以上でもよく、０．０５以上でもよく、０．１０以上でもよく、０．１５以上でもよく、０．２０以上でもよく、０．２５以上でもよい。ｎ１とｎ２との大小関係は逆でもよい。ｎ１－ｎ２の上限は特に制限されない。いくつかの態様において、粘着特性や透明性をバランスよく両立しやすくする観点等から、ｎ１－ｎ２は、例えば０．３０以下であってよく、０．２６以下でもよく、０．２１以下でもよく、０．１８以下でもよく、０．１６以下でもよい。第１粘着面と第２粘着面とで屈折率が異なる層間シートは、例えば、基材付き両面粘着シートにおいて非剥離性の支持基材に互いに屈折率の異なる第１、第２粘着剤層を積層することや、基材レス両面粘着シートを２以上のサブ粘着剤層の積層構造とし、該積層構造において第１粘着面を構成する粘着剤の屈折率と第２粘着面を構成する粘着剤の屈折率とを互いに異ならせることによって実現し得る。 In some other embodiments, the difference between the refractive index n 1 of the first adhesive surface of the interlayer sheet and the refractive index n 2 of the second adhesive surface, that is, n 1- n 2, is, for example, greater than 0.00. It may be 0.01 or more, preferably 0.02 or more, 0.03 or more, 0.05 or more, 0.10 or more, 0.15 or more, and 0. It may be 20 or more, or 0.25 or more. The magnitude relationship between n 1 and n 2 may be reversed. The upper limit of n 1 to n 2 is not particularly limited. In some embodiments, n 1 to n 2 may be, for example, 0.30 or less, 0.26 or less, 0.21 or less, from the viewpoint of making it easy to balance the adhesive properties and transparency in a well-balanced manner. It may be 0.18 or less, or 0.16 or less. The interlayer sheets having different refractive indices on the first adhesive surface and the second adhesive surface include, for example, first and second adhesive layers having different refractive indices from each other on a non-peelable supporting base material in a double-sided adhesive sheet with a base material. Lamination or a base-less double-sided adhesive sheet having a laminated structure of two or more sub-adhesive layers, and the refractive index of the adhesive constituting the first adhesive surface and the adhesive constituting the second adhesive surface in the laminated structure. It can be realized by making the refractive elements of the above different from each other.

　いくつかの態様において、第１粘着面の屈折率ｎ１と第２粘着面の屈折率ｎ２との比（ｎ１／ｎ２）は、例えば１．００より大であってよく、凡そ１．０１以上でもよく、凡そ１．０２以上であることが適当であり、凡そ１．０３以上でもよい。いくつかの態様において、比（ｎ１／ｎ２）は、凡そ１．０５以上であることが有利であり、凡そ１．０７以上であることが好ましく、凡そ１．１０以上であることがより好ましく、凡そ１．１１以上であってもよい。比（ｎ１／ｎ２）の上限は特に制限されない。いくつかの態様において、粘着特性や透明性等の観点から、比（ｎ１／ｎ２）は、例えば凡そ１．２０以下であってよく、凡そ１．１８以下でもよく、凡そ１．１６以下でもよく、凡そ１．１４以下でもよく、凡そ１．１２以下でもよい。 In some embodiments, the ratio of the refractive index n 1 of the first adhesive surface to the refractive index n 2 of the second adhesive surface (n 1 / n 2 ) may be, for example, greater than 1.00, approximately 1 It may be 0.01 or more, it is appropriate that it is about 1.02 or more, and it may be about 1.03 or more. In some embodiments, the ratio (n 1 / n 2 ) is preferably approximately 1.05 or greater, preferably approximately 1.07 or greater, and more preferably approximately 1.10 or greater. Preferably, it may be approximately 1.11 or more. The upper limit of the ratio (n 1 / n 2 ) is not particularly limited. In some embodiments, the ratio (n 1 / n 2 ) may be, for example, approximately 1.20 or less, may be approximately 1.18 or less, and may be approximately 1.16 or less from the viewpoint of adhesive properties, transparency, and the like. However, it may be about 1.14 or less, and may be about 1.12 or less.

　（貯蔵弾性率Ｇ’）
　ここに開示される層間シート（粘着シート）において、粘弾性層（粘着剤層）Ｖ１の２５℃における貯蔵弾性率Ｇ’（貯蔵弾性率Ｇ’V1(25)）は、使用目的や使用態様等に応じて適切に設定され、特定の範囲に限定されない。貯蔵弾性率Ｇ’V１(25)は、例えば凡そ３０ｋＰａ～７００ｋＰａの範囲であり得る。いくつかの態様において、被着体への貼付け容易性等の観点から、貯蔵弾性率Ｇ’V1(25)は、凡そ６００ｋＰａ以下であることが有利であり、５００ｋＰａ以下であることが好ましく、４００ｋＰａ以下（例えば３５０ｋＰａ以下）であることがより好ましい。いくつかの態様において、室温域（例えば２５℃）における粘着剤層Ｖ１の柔軟性を高めて被着体に密着させやすくする観点から、貯蔵弾性率Ｇ’V1(25)は、凡そ３３０ｋＰａ以下であることが有利であり、３００ｋＰａ以下であることが好ましい。室温域での貼付け性や柔軟性がより重視されるいくつかの態様において、貯蔵弾性率Ｇ’V1(25)は、例えば２７０ｋＰａ未満または２５０ｋＰａ未満であってよく、２００ｋＰａ未満であることが有利であり、１８０ｋＰａ未満であることが好ましく、１６０ｋＰａ未満（例えば１４０ｋＰａ未満）であることがより好ましい。いくつかの態様において、貯蔵弾性率Ｇ’V1(25)は、１００ｋＰａ未満であってもよく、９０ｋＰａ未満であってもよい。貯蔵弾性率Ｇ’V1(25)の下限は特に制限されないが、加工性や取扱い性等の観点から、例えば３０ｋＰａ以上であってよく、５０ｋＰａ以上でもよく、７０ｋＰａ以上でもよい。いくつかの態様において、高屈折率化を考慮して、貯蔵弾性率Ｇ’V1(25)は、１００ｋＰａ以上でもよく、１５０ｋＰａ以上でもよく、２００ｋＰａ以上でもよく、２５０ｋＰａ以上でもよく、３００ｋＰａ以上でもよい。 (Storage modulus G')
In the interlayer sheet (adhesive sheet) disclosed herein, the viscoelastic layer storage modulus G 25 ° C. of (pressure-sensitive adhesive layer) V 1 '(storage modulus G' V1 (25)), the intended use and mode of use It is set appropriately according to the above, and is not limited to a specific range. Storage modulus G 'V1 (25) may range for example approximately 30 kPa ~ 700 kPa. In some embodiments, from the viewpoint of joining easiness to an adherend, the storage modulus G 'V1 (25) is advantageously not more about 600kPa or less, preferably less 500 kPa, 400 kPa It is more preferably less than or equal to (for example, 350 kPa or less). In some embodiments, from the viewpoint of easily brought into close contact to increase the flexibility of the adhesive layer V 1 at room temperature range (e.g., 25 ° C.) to an adherend, the storage modulus G 'V1 (25) is approximately 330kPa below Is advantageous, and is preferably 300 kPa or less. In some embodiments the sticking resistance and flexibility at room temperature range is more important, the storage modulus G 'V1 (25), for example may be less than 270kPa or less than 250 kPa, advantageously less than 200kPa Yes, it is preferably less than 180 kPa, and more preferably less than 160 kPa (for example, less than 140 kPa). In some embodiments, the storage modulus G 'V1 (25) may be less than 100 kPa, may be less than 90 kPa. The lower limit of the storage elastic modulus G'V1 (25) is not particularly limited, but may be, for example, 30 kPa or more, 50 kPa or more, or 70 kPa or more from the viewpoint of workability and handleability. In some embodiments, the storage elastic modulus G'V1 (25) may be 100 kPa or higher, 150 kPa or higher, 200 kPa or higher, 250 kPa or higher, or 300 kPa or higher, in consideration of increasing the refractive index. ..

　ここに開示される粘着シートにおいて、粘弾性層（粘着剤層）Ｖ１の５０℃における貯蔵弾性率Ｇ’（貯蔵弾性率Ｇ’V1(50)）は、特に限定されず、例えば１００ｋＰａ未満であり得る。いくつかの態様において、貯蔵弾性率Ｇ’V1(50)は、６０ｋＰａ未満であることが適当であり、４０ｋＰａ未満であることが好ましく、３８ｋＰａ未満（例えば３６ｋＰａ未満）であることがより好ましい。このように貯蔵弾性率Ｇ’V1(50)が制限された粘着剤層Ｖ１は、必要に応じて適度な加熱を行うことにより被着体への密着性を容易に高めることができ、これにより被着体への接着性を向上させ得る。貯蔵弾性率Ｇ’V1(50)の下限は特に制限されない。いくつかの態様において、粘着剤層Ｖ１の耐熱特性等の観点から、貯蔵弾性率Ｇ’V1(50)は、例えば１０ｋＰａ以上であってよく、１５ｋＰａ以上でもよく、２０ｋＰａ以上でもよく、２３ｋＰａ以上でもよい。 In the PSA sheet disclosed herein, the viscoelastic layer storage modulus G 50 ° C. of (pressure-sensitive adhesive layer) V 1 '(storage modulus G' V1 (50)) is not particularly limited, for example, less than 100kPa could be. In some embodiments, the storage modulus G 'V1 (50) is suitably less than 60 kPa, preferably less than 40 kPa, more preferably less than 38KPa (e.g. less than 36 kPa). Thus the storage modulus G 'V1 (50) pressure-sensitive adhesive layer V 1 which is limited can be easily enhanced adhesion to an adherend by performing appropriate heating if necessary, this Therefore, the adhesiveness to the adherend can be improved. The lower limit of the storage elastic modulus G'V1 (50) is not particularly limited. In some embodiments, from the viewpoint of heat resistance of the adhesive layer V 1, the storage modulus G 'V1 (50) may be for example 10kPa or more may be at least 15 kPa, may be more than 20 kPa, more 23kPa It may be.

　ここに開示される層間シートのいくつかの態様において、粘弾性層（粘着剤層）Ｖ１は、以下の条件：
　（ａ）貯蔵弾性率Ｇ’V1(25)が３５０ｋＰａ以下（好ましくは２００ｋＰａ未満、例えば１８０ｋＰａ以下）である；および
　（ｂ）貯蔵弾性率Ｇ’V1(50)が６０ｋＰａ未満（好ましくは５０ｋＰａ未満、より好ましくは４０ｋＰａ未満、例えば３８ｋＰａ未満）である；
の少なくとも一方を満たすことが好ましい。少なくとも上記条件（ａ）を満たす粘着剤層Ｖ１は、室温域（例えば２５℃）における被着体への密着性や柔軟性の観点から好ましい。少なくとも上記条件（ｂ）を満たす粘着剤層Ｖ１を有する層間シートは、室温より少し高い程度の温度に加熱することで被着体への密着性（接着性）を容易に向上させ得るので好ましい。上記条件（ａ）を満たさずかつ上記（ｂ）を満たす粘着剤層Ｖ１を有する層間シートは、室温域での貼付けの初期にはリワーク性（貼直し性）がよく、室温より少し高い程度への温度への加熱により被着体からの剥離強度を効果的に上昇させることのできる、熱活性化タイプの層間シートとして利用され得る。上記熱活性化は、被着体への貼付けに際して層間シートを室温より少し高い程度の温度に加熱することにより行ってもよい。上記室温より少し高い程度の温度とは、例えば６０℃程度またはそれ以下であり、好ましくは５５℃程度またはそれ以下（例えば、５０℃程度またはそれ以下）である。 In some aspects of the interlayer sheet disclosed herein, the viscoelastic layer (adhesive layer) V 1 has the following conditions:
(A) storage modulus G 'V1 (25) is 350kPa or less (preferably less than 200 kPa, for example 180kPa or less); and (b) a storage modulus G' V1 (50) is less than 60 kPa (preferably less than 50 kPa, More preferably less than 40 kPa, eg less than 38 kPa);
It is preferable to satisfy at least one of the above. At least the adhesive layer V 1 that satisfies the above condition (a) is preferable from the viewpoint of adhesion and flexibility to an adherend at room temperature range (e.g., 25 ° C.). Preferred since at least the interlayer sheet having an adhesive layer V 1 that satisfies the above condition (b) may adhesion to adherends (adhesiveness) is easily improved by heating to a temperature at slightly above room temperature .. Interlayer sheet having an adhesive layer V 1 satisfying and the (b) not satisfy the above conditions (a), the reworkability the initial joining at room temperature range (pasted re resistance) C., the degree slightly higher than room temperature It can be used as a heat-activated type interlayer sheet capable of effectively increasing the peel strength from the adherend by heating to the temperature of. The thermal activation may be performed by heating the interlayer sheet to a temperature slightly higher than room temperature at the time of attachment to the adherend. The temperature slightly higher than the room temperature is, for example, about 60 ° C. or lower, preferably about 55 ° C. or lower (for example, about 50 ° C. or lower).

　ここに開示される層間シートのいくつかの態様において、貯蔵弾性率Ｇ’V1(25)［ｋＰａ］に対する貯蔵弾性率Ｇ’ V1(50)［ｋＰａ］の比、すなわち貯蔵弾性率比Ｇ’V1(50)／Ｇ’V1(25)は、例えば７０％以下であり、４０％以下でもよく、３０％以下でもよく、２０％以下でもよい。Ｇ’V1(50)／Ｇ’V1(25)が小さい粘着剤層Ｖ１を有する層間シートは、上記熱活性化タイプの層間シートとしての使用に適している。Ｇ’V1(50)／Ｇ’V1(25)の下限は特に制限されない。Ｇ’V1(50)／Ｇ’V1(25)は、例えば５％以上であり、層間シートの耐熱特性の観点から１０％以上であることが好ましく、１２％以上でもよく、１５％以上でもよい。 In some embodiments of the interlayer sheet disclosed herein, the ratio of V1 (50) [kPa] 'the storage modulus G for V1 (25) [kPa]' storage modulus G, i.e. storage modulus ratio G 'V1 (50) / G'V1 (25) is, for example, 70% or less, 40% or less, 30% or less, or 20% or less. Interlayer sheet having a G 'V1 (50) / G ' V1 (25) is less adhesive layer V 1 it was suitable for use as an interlayer sheet of the heat activated type. The lower limit of G'V1 (50) / G'V1 (25) is not particularly limited. G'V1 (50) / G'V1 (25) is, for example, 5% or more, preferably 10% or more from the viewpoint of heat resistance characteristics of the interlayer sheet, and may be 12% or more, or 15% or more. ..

　貯蔵弾性率Ｇ’V1(25)およびＧ’V1(50)は、動的粘弾性測定により求めることができ、その結果からＧ’V1(50)／Ｇ’V1(25)を算出することができる。動的粘弾性測定は、市販の動的粘弾性測定装置を用いて常法により行うことができ、例えばTA Instruments社製のＡＲＥＳまたはその相当品を使用して、以下の測定条件で行うことができる。測定用のサンプルとしては、評価対象の粘着剤層を必要に応じて積層する等して厚さ約１．５ｍｍに調製したものを用いる。
　　［測定条件］
　変形モード：ねじり
　測定周波数：１Ｈｚ
　昇温速度：５℃／分
　形状：パラレルプレート　７．９ｍｍφ The storage elastic moduli G'V1 (25) and G'V1 (50) can be obtained by dynamic viscoelasticity measurement, and G'V1 (50) / G'V1 (25) can be calculated from the results. can. The dynamic viscoelasticity measurement can be performed by a conventional method using a commercially available dynamic viscoelasticity measuring device, and can be performed under the following measurement conditions using, for example, ARES manufactured by TA Instruments or an equivalent product thereof. can. As the sample for measurement, a sample prepared to have a thickness of about 1.5 mm by laminating the pressure-sensitive adhesive layer to be evaluated as necessary is used.
[Measurement condition]
Deformation mode: Torsion measurement frequency: 1Hz
Temperature rise rate: 5 ° C / min Shape: Parallel plate 7.9 mmφ

　粘弾性層（粘着剤層）Ｖ１の貯蔵弾性率Ｇ’V1(25)、Ｇ’V1(50)および貯蔵弾性率比は、該粘着剤層Ｖ１のベースポリマーを構成するモノマー成分の組成の選択（例えば、モノマー（ｍ１）の種類および含有量の選択）、架橋剤の使用有無および使用量の選択、後述する屈折率向上剤や可塑化材料の使用有無、種類および使用量の選択）等により調節し得る。例えば、モノマー（ｍ１）として、該モノマー（ｍ１）の主成分である第１のモノマーに加えて、該第１のモノマーとは化学構造の異なる第２のモノマーを比較的少量、上記第１のモノマーと組み合わせて使用することにより、モノマー（ｍ１）として第１のモノマーを単独で用いる場合に加えてＧ’V1(50)を小さくし、Ｇ’V1(50)／Ｇ’V1(25)を低下させ得る。 Viscoelastic layer storage modulus G (pressure-sensitive adhesive layer) V 1 'V1 (25) , G' V1 (50) and storage modulus ratio, the composition of the monomer components constituting the base polymer of the pressure-sensitive adhesive layer V 1 (For example, selection of the type and content of the monomer (m1)), selection of the presence / absence and amount of the cross-linking agent used, selection of the use / absence of the refractive modulus improver and the thermoplastic material described later, selection of the type and the amount used) It can be adjusted by such as. For example, as the monomer (m1), in addition to the first monomer which is the main component of the monomer (m1), a relatively small amount of a second monomer having a chemical structure different from that of the first monomer is used in the first monomer. By using it in combination with a monomer, G'V1 (50) is reduced and G'V1 (50) / G'V1 (25) is reduced in addition to the case where the first monomer is used alone as the monomer (m1). Can be reduced.

　ここに開示される粘着シートが、第１粘着面および第２粘着面を有する両面粘着シート（例えば、基材の第１面に粘着剤層Ｖ１により構成された第１粘着剤層を有し、該基材の第２面に粘着剤層Ｖ２により構成された第２粘着剤層を有する基材付き両面粘着シート、第１粘着面を構成する粘着剤層Ｖ１と第２粘着面を構成する粘着剤層Ｖ２とが非粘着性の基材を介することなく積層した積層構造の基材レス両面粘着シート、粘着剤層Ｖ１の一方の面が第１粘着面となっており、該粘着剤層Ｖ１の他方の面が第２粘着面となっている単層構造の基材レス両面粘着シート等。他の同様の記載においても同様。）の形態である場合、上述した貯蔵弾性率Ｇ’V1(25)、Ｇ’V1(50)および貯蔵弾性率比は、少なくとも第１粘着面を構成する粘着剤層に適用され、好ましくは第１粘着面を構成する粘着剤層および第２粘着面を構成する粘着剤層の両方に適用される。第１粘着面を構成する粘着剤層の貯蔵弾性率Ｇ’と第２粘着面を構成する粘着剤層の貯蔵弾性率Ｇ’とは、同程度であってもよく、異なっていてもよい。 PSA sheet disclosed herein is, double-sided pressure-sensitive adhesive sheet having a first adhesive surface and a second adhesive surface (e.g., having a first pressure-sensitive adhesive layer constituted of a pressure-sensitive adhesive layer V 1 on the first surface of the substrate , the second pressure-sensitive adhesive layer with a substrate double-sided pressure-sensitive adhesive sheet having constituted by the pressure-sensitive adhesive layer V 2 on the second surface of the substrate, and an adhesive layer V 1 constituting the first adhesive surface of the second adhesive surface A base material-less double-sided pressure-sensitive adhesive sheet having a laminated structure in which the constituent pressure-sensitive adhesive layer V 2 is laminated without a non-stick-based base material, and one surface of the pressure-sensitive adhesive layer V 1 is the first pressure-sensitive adhesive surface. when the other surface of the pressure-sensitive adhesive layer V 1 is in the form of a well.) also in the substrate-less double-sided pressure-sensitive adhesive sheet or the like. other similar description of the single-layer structure in which a second adhesive surface, storage described above The elastic ratios G'V1 (25), G'V1 (50) and the storage elastic ratio are applied to at least the pressure-sensitive adhesive layer constituting the first pressure-sensitive adhesive surface, and preferably the pressure-sensitive adhesive layer constituting the first pressure-sensitive adhesive surface and the pressure-sensitive adhesive layer. It is applied to both of the pressure-sensitive adhesive layers constituting the second pressure-sensitive adhesive surface. The storage elastic modulus G'of the pressure-sensitive adhesive layer constituting the first adhesive surface and the storage elastic modulus G'of the pressure-sensitive adhesive layer forming the second adhesive surface may be about the same or different.

　（全光線透過率）
　ここに開示される層間シートは、上記の高屈折率を有する粘着剤層Ｖ１を含み、かつ該層間シートの全光線透過率が８６％以上である。このように透明性の高い層間シートは、基材を有する構成または有しない構成において、高い光透過性が求められる用途（例えば光学用途）や、該粘着シートを通して被着体を良好に視認し得る性能が求められる用途に好ましく適用され得る。いくつかの態様において、層間シートの全光線透過率は、８８％以上であることが好ましく、９０％以上（例えば９０．０％超）であることがより好ましく、９０．５％以上でもよく、９３％以上でもよく、９５％以上でもよい。全光線透過率の上限は、理論的には、１００％から空気界面で生じる反射による光損失（フレネルロス）を除いた値となり、実用上、凡そ９８％以下であってよく、凡そ９６％以下でもよく、凡そ９５％以下でもよい。いくつかの態様では、屈折率や粘着特性を考慮して、層間シートの全光線透過率は、凡そ９４％以下でもよく、凡そ９３％以下でもよく、凡そ９２％以下でもよい。全光線透過率は、ＪＩＳ　Ｋ　７１３６：２０００に準拠して、市販の透過率計を使用して測定される。透過率計としては、村上色彩技術研究所製の商品名「ＨＡＺＥＭＥＴＥＲ　ＨＭ－１５０」またはその相当品が用いられる。より具体的には、例えば後述の実施例に従って層間シートの全光線透過率を測定することができる。層間シートの全光線透過率は、例えば、該層間シートに含まれる粘弾性層の組成や厚さ、基材を含む構成における該基材の種類や厚さ、等の選択によって調節することができる。 (Total light transmittance)
Interlayer sheet disclosed herein comprises a PSA layer V 1 having a high refractive index of above and total light transmittance of the interlayer sheet is 86% or more. Such a highly transparent interlayer sheet can be used for applications requiring high light transmission (for example, optical applications) in a configuration having or not having a base material, and an adherend can be satisfactorily visually recognized through the adhesive sheet. It can be preferably applied to applications where performance is required. In some embodiments, the total light transmittance of the interlayer sheet is preferably 88% or more, more preferably 90% or more (for example, more than 90.0%), and may be 90.5% or more. It may be 93% or more, or 95% or more. Theoretically, the upper limit of the total light transmittance is a value obtained by subtracting the light loss (Frenel loss) due to reflection generated at the air interface from 100%, and practically, it may be about 98% or less, or even about 96% or less. Well, it may be about 95% or less. In some embodiments, the total light transmittance of the interlayer sheet may be about 94% or less, about 93% or less, or about 92% or less in consideration of the refractive index and the adhesive property. Total light transmittance is measured using a commercially available transmittance meter in accordance with JIS K 7136: 2000. As the transmittance meter, the trade name "HAZEMETER HM-150" manufactured by Murakami Color Technology Research Institute or its equivalent is used. More specifically, for example, the total light transmittance of the interlayer sheet can be measured according to the examples described later. The total light transmittance of the interlayer sheet can be adjusted by selecting, for example, the composition and thickness of the viscoelastic layer contained in the interlayer sheet, the type and thickness of the base material in the configuration including the base material, and the like. ..

　ここに開示される層間シートが、第１粘着剤層および第２粘着剤層が支持基材に固定的に積層された基材付き両面粘着シートの形態であって、第１粘着剤層が粘着剤層Ｖ１により構成された層である場合、少なくとも該第１粘着剤層が上述したいずれかの全光線透過率を満たせばよく、第２粘着剤層の全光線透過率は特に特に制限されない。粘着シートの厚み方向に光が通り抜ける使用態様では、第２粘着剤層の全光線透過率が、上述した第１粘着剤層の全光線透過率のいずれかを満たすことが好ましい。両粘着剤層の全光線透過率の相対関係は、第１粘着剤層＞第２粘着剤層でもよく、第１粘着剤層＜第２粘着剤層でもよく、第１粘着剤層＝第２粘着剤層でもよい。 The interlayer sheet disclosed herein is in the form of a double-sided pressure-sensitive adhesive sheet with a base material in which a first pressure-sensitive adhesive layer and a second pressure-sensitive adhesive layer are fixedly laminated on a support base material, and the first pressure-sensitive adhesive layer adheres. when a layer constituted by adhesive layer V 1, may satisfy one of the total light transmittance of at least the first pressure-sensitive adhesive layer described above, the total light transmittance of the second pressure-sensitive adhesive layer is not particularly limited particularly .. In the usage mode in which light passes through in the thickness direction of the pressure-sensitive adhesive sheet, it is preferable that the total light transmittance of the second pressure-sensitive adhesive layer satisfies any of the total light transmittance of the first pressure-sensitive adhesive layer described above. The relative relationship between the total light transmittances of both pressure-sensitive adhesive layers may be the first pressure-sensitive adhesive layer> the second pressure-sensitive adhesive layer, the first pressure-sensitive adhesive layer <the second pressure-sensitive adhesive layer, and the first pressure-sensitive adhesive layer = the second. It may be an adhesive layer.

　（ヘイズ値）
　ここに開示される層間シートは、上記の高屈折率を有する粘着剤層Ｖ１を含み、かつ、かつ該層間シートのヘイズ値が１．０％以下である。このように透明性の高い層間シートは、基材を有する構成または有しない構成において、高い光透過性が求められる用途（例えば光学用途）や、該層間シートを通して被着体を良好に視認し得る性能が求められる用途に好ましく適用され得る。いくつかの態様において、層間シートのヘイズ値は、０．９％以下でもよく、０．８％以下でもよく、０．５％以下でもよく、０．３％以下でもよい。層間シートのヘイズ値の下限は特に制限されず、透明性向上の観点からはヘイズ値は小さいほど好ましい。一方、いくつかの態様では、屈折率や粘着特性を考慮して、層間シートのヘイズ値は、例えば０．０５％以上であってよく、０．１％以上でもよく．０．２％以上でもよく、０．３％以上でもよく、０．４％以上でもよい。層間シートに関するこれらのヘイズ値は、ここに開示される技術を基材レス粘着シート（典型的には、粘着剤層からなる粘着シート）の形態で実施する場合における該粘着シートのヘイズ値にも好ましく適用され得る。 (Haze value)
Interlayer sheet disclosed herein comprises a PSA layer V 1 having a high refractive index of above and, and haze value of the interlayer sheet is 1.0% or less. Such a highly transparent interlayer sheet can be used for applications requiring high light transmission (for example, optical applications) in a configuration having or not having a base material, and an adherend can be satisfactorily visually recognized through the interlayer sheet. It can be preferably applied to applications where performance is required. In some embodiments, the haze value of the interlayer sheet may be 0.9% or less, 0.8% or less, 0.5% or less, or 0.3% or less. The lower limit of the haze value of the interlayer sheet is not particularly limited, and a smaller haze value is preferable from the viewpoint of improving transparency. On the other hand, in some embodiments, the haze value of the interlayer sheet may be, for example, 0.05% or more, or 0.1% or more, in consideration of the refractive index and the adhesive property. It may be 0.2% or more, 0.3% or more, or 0.4% or more. These haze values for the interlayer sheet are also the haze values of the pressure-sensitive adhesive sheet when the technique disclosed herein is carried out in the form of a base material-less pressure-sensitive adhesive sheet (typically, a pressure-sensitive adhesive sheet composed of an adhesive layer). It may be preferably applied.

　ここで「ヘイズ値」とは、測定対象に可視光を照射したときの、全透過光に対する拡散透過光の割合をいう。くもり価ともいう。ヘイズ値は、以下の式で表すことができる。
　　　Ｔｈ（％）＝Ｔｄ／Ｔｔ×１００
　上記式において、Ｔｈはヘイズ値（％）であり、Ｔｄは散乱光透過率、Ｔｔは全光透過率である。ヘイズ値の測定は、後述の実施例に記載の方法に従って行うことができる。ヘイズ値は、例えば、測定対象の組成や厚さ等の選択によって調節することができる。 Here, the "haze value" refers to the ratio of diffuse transmitted light to total transmitted light when the measurement target is irradiated with visible light. Also called cloudy value. The haze value can be expressed by the following formula.
Th (%) = Td / Tt × 100
In the above formula, Th is a haze value (%), Td is a scattered light transmittance, and Tt is a total light transmittance. The haze value can be measured according to the method described in Examples described later. The haze value can be adjusted, for example, by selecting the composition and thickness of the measurement target.

　ここに開示される層間シートが、第１粘着剤層および第２粘着剤層が支持基材に固定的に積層された基材付き両面粘着シートの形態である場合、該層間シートは、全体として上述したいずれかのヘイズ値を満たせばよく、第１粘着剤層および第２粘着剤層の各々のヘイズ値は特に特に制限されない。両粘着剤層のヘイズ値の相対関係は、第１粘着剤層＞第２粘着剤層でもよく、第１粘着剤層＜第２粘着剤層でもよく、第１粘着剤層＝第２粘着剤層でもよい。すなわち、第１粘着剤層のヘイズ値と、第２粘着剤層のヘイズ値とは、同程度であってもよく、異なっていてもよい。ここに開示される層間シートが複数のサブ粘着剤層（例えば、粘着剤層Ｖ１および粘着剤層Ｖ２）が直接積層した粘着剤層を含む場合における各サブ粘着剤層のヘイズ値についても同様である。 When the interlayer sheet disclosed herein is in the form of a double-sided pressure-sensitive adhesive sheet with a base material in which a first pressure-sensitive adhesive layer and a second pressure-sensitive adhesive layer are fixedly laminated on a support base material, the interlayer sheet as a whole Any of the above-mentioned haze values may be satisfied, and the haze values of the first pressure-sensitive adhesive layer and the second pressure-sensitive adhesive layer are not particularly limited. The relative relationship between the haze values of both adhesive layers may be 1st adhesive layer> 2nd adhesive layer, 1st adhesive layer <2nd adhesive layer, and 1st adhesive layer = 2nd adhesive. It may be a layer. That is, the haze value of the first pressure-sensitive adhesive layer and the haze value of the second pressure-sensitive adhesive layer may be about the same or different. The haze value of each sub-adhesive layer when the interlayer sheet disclosed herein includes an adhesive layer in which a plurality of sub-adhesive layers (for example, the adhesive layer V 1 and the adhesive layer V 2) are directly laminated is also obtained. The same is true.

　（粘着面の表面平滑性）
　ここに開示される層間シートのいくつかの態様において、該層間シートの粘着面（例えば、粘着剤層Ｖ１により構成された粘着面）は、高い表面平滑性を有することが好ましい。 (Surface smoothness of adhesive surface)
In some embodiments of the interlayer sheet disclosed herein, the adhesive surface of the interlayer sheet (e.g., adhesive surface configured by an adhesive layer V 1) preferably has a high surface smoothness.

　例えば、上記粘着面は、その算術平均粗さＲａが所定値以下に制限されていることが好ましい。算術平均粗さＲａが低くなるように設計された粘着面を備える構成は、光学的均質性の観点から好ましい。算術平均粗さＲａを制限することにより、例えば上記粘着面を通じて光が取り出される使用態様（発光装置において自発光素子よりも視点側に配置される層間シート等）において、粘着剤層の表面状態に起因する輝度ムラの発生を抑制する効果を発揮することができる。粘着面の算術平均粗さＲａが低いことは、光学歪の抑制にも有利であり、光学歪の抑制もまた光学的均質性の向上に寄与する。ここに開示される層間粘着シートが第１粘着面および第２粘着面を有する両面粘着シートの形態である場合には、少なくとも第１粘着面の算術平均粗さＲａが所定値以下に制限されていることが好ましく、両粘着面の算術平均粗さＲａがいずれも所定値以下に制限されていることがより好ましい。両面粘着シートの各粘着面が高い表面平滑性を有することで、光学的均質性に優れた接着を好ましく実現し得る。 For example, it is preferable that the arithmetic average roughness Ra of the adhesive surface is limited to a predetermined value or less. A configuration having an adhesive surface designed to have a low arithmetic mean roughness Ra is preferable from the viewpoint of optical homogeneity. By limiting the arithmetic mean roughness Ra, for example, in a usage mode in which light is extracted through the adhesive surface (such as an interlayer sheet arranged on the viewpoint side of the self-luminous element in a light emitting device), the surface state of the adhesive layer can be changed. It is possible to exert the effect of suppressing the occurrence of brightness unevenness caused by it. The low arithmetic mean roughness Ra of the adhesive surface is also advantageous for suppressing optical strain, and the suppression of optical strain also contributes to the improvement of optical homogeneity. When the interlayer adhesive sheet disclosed herein is in the form of a double-sided adhesive sheet having a first adhesive surface and a second adhesive surface, at least the arithmetic mean roughness Ra of the first adhesive surface is limited to a predetermined value or less. It is more preferable that the arithmetic average roughness Ra of both adhesive surfaces is limited to a predetermined value or less. Since each adhesive surface of the double-sided adhesive sheet has high surface smoothness, it is possible to preferably realize adhesion having excellent optical homogeneity.

　いくつかの態様において、粘着面の算術平均粗さＲａは、好ましくは凡そ７０ｎｍ以下であり、より好ましくは凡そ６５ｎｍ以下であり、さらに好ましくは凡そ５５ｎｍ以下であり、５０ｎｍ未満であってもよく、４５ｎｍ未満でもよく、４０ｎｍ未満でもよい。生産効率等の観点から、いくつかの態様において、粘着面の算術平均粗さＲａは、例えば凡そ１０ｎｍ以上であってよく、凡そ２０ｎｍ以上でもよく、凡そ３０ｎｍ以上（例えば凡そ４０ｎｍ以上）でもよい。第１粘着面および第２粘着面を有する態様の層間シートにおいて、第１粘着面の算術平均粗さＲａと第２粘着面の算術平均粗さＲａとは、同程度であってもよく、異なっていてもよい。 In some embodiments, the arithmetic mean roughness Ra of the adhesive surface is preferably about 70 nm or less, more preferably about 65 nm or less, still more preferably about 55 nm or less, and may be less than 50 nm. It may be less than 45 nm or less than 40 nm. From the viewpoint of production efficiency and the like, in some embodiments, the arithmetic mean roughness Ra of the adhesive surface may be, for example, about 10 nm or more, about 20 nm or more, or about 30 nm or more (for example, about 40 nm or more). In the interlayer sheet having the first adhesive surface and the second adhesive surface, the arithmetic average roughness Ra of the first adhesive surface and the arithmetic average roughness Ra of the second adhesive surface may be the same or different. May be.

　また、例えば、上記粘着面は、最大高さＲｚが所定値以下に制限されていることが好ましい。最大高さＲｚが低くなるよう設計された粘着面を備える構成は、光学的均質性の観点から好ましい。最大高さＲｚを制限することにより、例えば上述のように上記粘着面を通じて光が取り出される使用態様において、粘着剤層の表面状態に起因する輝度ムラの発生を抑制する効果を発揮することができる。粘着面の最大高さＲｚが低いことは、光学歪の抑制にも有利である。ここに開示される層間シートが第１粘着面および第２粘着面を有する両面粘着シートの形態である場合は、少なくとも第１粘着面の最大高さＲｚが所定値以下に制限されていることが好ましく、両粘着面の最大高さＲｚがいずれも所定値以下に制限されていることがより好ましい。両面粘着シートの各粘着面が高い表面平滑性を有することで、光学的均質性に優れた接着を好ましく実現し得る。 Further, for example, it is preferable that the maximum height Rz of the adhesive surface is limited to a predetermined value or less. A configuration having an adhesive surface designed to have a low maximum height Rz is preferable from the viewpoint of optical homogeneity. By limiting the maximum height Rz, for example, in the usage mode in which light is extracted through the adhesive surface as described above, it is possible to exert the effect of suppressing the occurrence of luminance unevenness due to the surface state of the adhesive layer. .. The low maximum height Rz of the adhesive surface is also advantageous for suppressing optical distortion. When the interlayer sheet disclosed here is in the form of a double-sided adhesive sheet having a first adhesive surface and a second adhesive surface, at least the maximum height Rz of the first adhesive surface is limited to a predetermined value or less. It is preferable that the maximum height Rz of both adhesive surfaces is limited to a predetermined value or less. Since each adhesive surface of the double-sided adhesive sheet has high surface smoothness, it is possible to preferably realize adhesion having excellent optical homogeneity.

　いくつかの態様において、粘着面の最大高さＲｚは、好ましくは凡そ６００ｎｍ以下であり、より好ましくは凡そ５００ｎｍ以下であり、さらに好ましくは凡そ４５０ｎｍ以下であり、特に好ましくは凡そ４００ｎｍ以下であり、３５０ｎｍ未満であってもよく、３００ｎｍ未満でもよく、２５０ｎｍ未満でもよい。生産効率等の観点から、いくつかの態様において、粘着面の最大高さＲｚは、例えば凡そ１０ｎｍ以上であってよく、凡そ５０ｎｍ以上でもよく、凡そ１００ｎｍ以上でもよく、凡そ２００ｎｍ以上でもよい。第１粘着面および第２粘着面を有する態様の層間シートにおいて、第１粘着面の最大高さＲｚと第２粘着面の最大高さＲｚとは、同程度であってもよく、異なっていてもよい。 In some embodiments, the maximum height Rz of the adhesive surface is preferably about 600 nm or less, more preferably about 500 nm or less, still more preferably about 450 nm or less, and particularly preferably about 400 nm or less. It may be less than 350 nm, less than 300 nm, or less than 250 nm. From the viewpoint of production efficiency and the like, in some embodiments, the maximum height Rz of the adhesive surface may be, for example, about 10 nm or more, about 50 nm or more, about 100 nm or more, or about 200 nm or more. In the interlayer sheet having the first adhesive surface and the second adhesive surface, the maximum height Rz of the first adhesive surface and the maximum height Rz of the second adhesive surface may be the same or different. May be good.

　粘着面の算術平均粗さＲａおよび最大高さＲｚは、非接触式の表面粗さ測定装置を用いて測定される。非接触式の表面粗さ測定装置としては、光干渉方式の表面粗さ測定装置が用いられ、例えば３次元光学プロファイラー（商品名「ＮｅｗＶｉｅｗ７３００」、ＺＹＧＯ社製）またはその相当品を使用することができる。具体的には、例えば以下の測定方法により、または該測定方法による場合と同等もしくは対応する結果が得られるように測定操作や測定条件を設定して、算術平均粗さＲａおよび最大高さＲｚを測定することができる。 The arithmetic mean roughness Ra and the maximum height Rz of the adhesive surface are measured using a non-contact type surface roughness measuring device. As the non-contact type surface roughness measuring device, a light interference type surface roughness measuring device is used, and for example, a three-dimensional optical profiler (trade name "NewView7300", manufactured by ZYGO) or an equivalent product thereof can be used. can. Specifically, for example, the arithmetic mean roughness Ra and the maximum height Rz are set by the following measurement method, or by setting the measurement operation and measurement conditions so that the same or corresponding results as those obtained by the measurement method can be obtained. Can be measured.

　すなわち、２３℃、５０％ＲＨの環境下において、３次元光学プロファイラー（商品名「ＮｅｗＶｉｅｗ７３００」、ＺＹＧＯ社製）を用いて、測定用サンプルの表面形状を以下の条件で測定する。測定したデータから算術表面粗さＲａを、ＪＩＳ　Ｂ　０６０１－２００１に準じて算出する。最大高さＲｚは、上記測定により得られたデータ（粗さ曲線）について、該粗さ曲線の平均線から上側に最も高い山の高さＲｐと、上記平均線から下側に最も深い谷の深さＲｖとの和として求める。測定は５回行い（すなわちＮ＝５）、それらの平均値を使用する。
　上記測定用サンプルは、例えば、測定対象の粘着剤層または該粘着剤層を含む層間シートを長さ１５０ｍｍ、幅５０ｍｍ程度のサイズにカットして調製することができる。粘着面が剥離ライナーで保護されている場合は、該剥離ライナーを静かに（例えば、引張速度３００ｍｍ／分、剥離角度１８０°の条件で）剥がして粘着面を露出させる。粘着面を露出させてから３０分間程度静置した後に測定を行うことが望ましい。
　　［測定条件］
　　測定面積：５．６２ｍｍ×４．２２ｍｍ
　　（対物レンズ：２．５倍、内部レンズ：０．５倍）
　　解析モード：
　　　Ｒｅｍｏｖｅ：　Ｃｙｌｉｎｄｅｒ
　　　Ｄａｔａ　Ｆｉｌｌ：　ＯＮ（Ｍａｘ：２５）
　　　Ｒｅｍｏｖｅ　Ｓｐｉｋｅｓ：　ＯＮ　（ｘＲＭＳ：１）
　　　Ｆｉｌｔｅｒ：　ＯＦＦ That is, in an environment of 23 ° C. and 50% RH, the surface shape of the measurement sample is measured under the following conditions using a three-dimensional optical profiler (trade name “NewView7300”, manufactured by ZYGO). Arithmetic surface roughness Ra is calculated from the measured data according to JIS B 0601-2001. The maximum height Rz is the height Rp of the highest mountain above the average line of the roughness curve and the deepest valley below the average line of the data (roughness curve) obtained by the above measurement. Obtained as the sum of the depth Rv. The measurement is performed 5 times (ie N = 5) and the average value thereof is used.
The measurement sample can be prepared, for example, by cutting the pressure-sensitive adhesive layer to be measured or the interlayer sheet containing the pressure-sensitive adhesive layer into a size of about 150 mm in length and 50 mm in width. When the adhesive surface is protected by a release liner, the release liner is gently peeled off (for example, under the conditions of a tensile speed of 300 mm / min and a release angle of 180 °) to expose the adhesive surface. It is desirable to perform the measurement after allowing the adhesive surface to stand for about 30 minutes after exposing it.
[Measurement condition]
Measurement area: 5.62 mm x 4.22 mm
(Objective lens: 2.5x, internal lens: 0.5x)
Analysis mode:
Remove: Cylinder
Data Fill: ON (Max: 25)
Remove Spirits: ON (xRMS: 1)
Filter: OFF

　粘着面の算術平均粗さＲａおよび最大高さＲｚは、粘着剤層の形成に用いる粘着剤組成物の組成や性状（粘度、レベリング性等）、粘着面を保護する剥離ライナーの表面（剥離面）の性状等によって調節され得る。 The arithmetic mean roughness Ra and maximum height Rz of the adhesive surface are the composition and properties (viscosity, leveling property, etc.) of the adhesive composition used to form the adhesive layer, and the surface of the release liner that protects the adhesive surface (release surface). ) Can be adjusted according to the properties.

　（吸水率）
　いくつかの態様において、粘着剤層Ｖ１は、吸水率が所定値以下に制限されていることが好ましい。粘着剤層Ｖ１の吸水率を制限することにより、該粘着剤層Ｖ１中の水分量の変動（例えば、環境中の湿気等の水分の吸収および放出）による粘弾性層Ｖ１の寸法変化は抑制される傾向にある。これにより、粘着剤層Ｖ１とこれに隣接する層（粘着剤層Ｖ２、支持基材、剥離ライナー、被着体等であり得る。）との寸法変化の不一致に起因する層間シートまたは該層間シートを含む光学積層体の反りを抑制することができる。粘着剤層Ｖ１中の水分量の変動を抑制し得ることは、粘着剤層Ｖ１の平坦性、透明性、屈折率等を一定に維持する観点からも好ましい。また、吸水率の低い粘着剤層Ｖ１を有する層間シートは、水分を吸蔵しにくいため、例えば有機ＥＬ素子のように水分を嫌う要素を含む部材または製品に用いられる層間シートとして好適である。 (Water absorption rate)
In some embodiments, the adhesive layer V 1 was, it is preferable that the water absorption is limited to a predetermined value or less. By limiting the water absorption of the adhesive layer V 1, the variation of the moisture content of the pressure-sensitive adhesive layer V of 1 (e.g., absorption of water such as moisture in the environment and release) the dimensional change of the viscoelastic layer V 1 by Tends to be suppressed. As a result, the interlayer sheet or the interlayer sheet due to the discrepancy in the dimensional change between the pressure-sensitive adhesive layer V 1 and the layer adjacent thereto (which may be the pressure-sensitive adhesive layer V 2, the supporting base material, the release liner, the adherend, etc.). Warpage of the optical laminate including the interlayer sheet can be suppressed. It is preferable that the fluctuation of the water content in the pressure-sensitive adhesive layer V 1 can be suppressed from the viewpoint of maintaining the flatness, transparency, refractive index and the like of the pressure-sensitive adhesive layer V 1 constant. Further, an interlayer sheet having a low pressure-sensitive adhesive layer V 1 of water absorption, since it is difficult to absorb moisture, is suitable as an interlayer sheet used in the member or product includes elements dislike moisture, for example, as an organic EL element.

　いくつかの態様において、粘着剤層Ｖ１の吸水率は、凡そ１．０％以下であることが適当であり、０．７％以下であることが好ましく、０．５％以下（例えば０．５％未満）であることがより好ましく、０．４％以下でもよく、０．３％以下でもよく、０．２％以下でもよい。粘着剤層Ｖ１の吸水率の下限は特に制限されないが、粘着特性との両立等の実用上の観点から、例えば０．０１％以上であってよく、０．０５％以上でもよく、０．１％以上でもよく、０．１５％以上でもよく、０．２５％以上でもよい。ここに開示される層間シートが第１粘着剤層と第２粘着剤層とを有する基材付き両面粘着シートの形態である場合は、少なくとも第１粘着剤層（好ましくは粘着剤層Ｖ１）の吸水率が所定値以下に制限されていることが好ましい。より高い効果を得る観点から、第１、第２粘着剤層の吸水率がいずれも所定値以下に制限されていることがより好ましい。 In some embodiments, the water absorption of the adhesive layer V 1 was, is suitably not more than about 1.0%, preferably at most 0.7%, 0.5% or less (e.g., 0. It is more preferably less than 5%), and may be 0.4% or less, 0.3% or less, or 0.2% or less. The lower limit of the water absorption rate of the pressure-sensitive adhesive layer V 1 is not particularly limited, but from a practical point of view such as compatibility with the pressure-sensitive adhesive properties, for example, it may be 0.01% or more, 0.05% or more, and 0. It may be 1% or more, 0.15% or more, or 0.25% or more. When the interlayer sheet disclosed herein is in the form of a double-sided pressure-sensitive adhesive sheet with a base material having a first pressure-sensitive adhesive layer and a second pressure-sensitive adhesive layer, at least the first pressure-sensitive adhesive layer (preferably the pressure-sensitive adhesive layer V 1 ). It is preferable that the water absorption rate of the above is limited to a predetermined value or less. From the viewpoint of obtaining a higher effect, it is more preferable that the water absorption rates of the first and second pressure-sensitive adhesive layers are all limited to a predetermined value or less.

　なお、粘着剤層の吸水率（水分率ともいう。）は、以下の方法により測定される。
　　[水分率の測定]
　評価対象の粘着剤層を、その一方の面および他方の面上に配置された２枚の剥離ライナーとともに４ｃｍ×５ｃｍ（面積：２０ｃｍ２）のサイズに切り出し、一方の面上の剥離ライナーを除去して、あらかじめ秤量しておいたアルミニウム箔に貼り合わせる。次いで、粘着剤層の他方の面上の剥離ライナーを除去し、温度６０℃、相対湿度９０％の恒温恒湿槽に投入し、７２時間後に取り出す。粘着剤層とアルミニウム箔とが積層された試験片を秤量した後、加熱気化装置（三菱化学アナリテック　ＶＡ－２００型）を備える水分計（三菱化学アナリテック　ＣＡ－２００型）を用い、カールフィッシャー電量滴定法により、以下の条件で水分率を測定する。 
　　陽極液：アクアミクロンＡＫＸ（三菱化学製）
　　陰極液：アクアミクロンＣＸＵ（三菱化学製）
　　加熱気化温度：１５０℃ The water absorption rate (also referred to as water content) of the pressure-sensitive adhesive layer is measured by the following method.
[Measurement of moisture content]
The pressure-sensitive adhesive layer to be evaluated is cut into a size of 4 cm × 5 cm (area: 20 cm 2 ) together with two release liners arranged on one surface and the other surface, and the release liner on one surface is removed. Then, it is attached to the aluminum foil that has been weighed in advance. Next, the release liner on the other surface of the pressure-sensitive adhesive layer is removed, placed in a constant temperature and humidity chamber having a temperature of 60 ° C. and a relative humidity of 90%, and taken out after 72 hours. After weighing the test piece in which the pressure-sensitive adhesive layer and the aluminum foil are laminated, use a moisture meter (Mitsubishi Chemical Analytech CA-200 type) equipped with a heating vaporizer (Mitsubishi Chemical Analytech VA-200 type) to curl fisher. The water content is measured under the following conditions by the coulometric titration method.
Anode solution: Aquamicron AKX (manufactured by Mitsubishi Chemical Corporation)
Cathode solution: Aquamicron CXU (manufactured by Mitsubishi Chemical Corporation)
Heating vaporization temperature: 150 ° C

　（ゲル分率）
　粘弾性層Ｖ１のゲル分率は、使用目的や使用態様等に応じて適切に設定され、特定の範囲に限定されるものではない。上記ゲル分率は、例えば凡そ９９％以下であり、凡そ９７％以下が適当である。高屈折率と粘着特性とを好適に両立しやすくする観点から、いくつかの好ましい態様では、上記ゲル分率は凡そ９５％以下であり、より好ましくは凡そ９２％以下（例えば凡そ９０％以下）であり得る。ゲル分率が高すぎないことは、被着体表面に存在し得る凹凸（例えば、発光装置において光取出し効率の向上等を目的として設けられた凹凸構造）に対して適切に追従し、良好に密着する観点からも好ましい。いくつかの態様において、ゲル分率は、凡そ８８％以下であってもよく、凡そ７５％以下でもよく、凡そ６５％以下でもよい。また、上記ゲル分率は、粘着剤に適度な凝集性を付与し、粘着特性を適切に発現する観点から、例えば凡そ１０％以上であり、凡そ２０％以上とすることが適当であり、凡そ３０％以上であってもよい。粘弾性層Ｖ１の耐変形性（圧力によるはみ出しや異物のかみ込みによる気泡の防止等）の観点から、上記ゲル分率は、好ましくは凡そ３０％以上、より好ましくは凡そ４０％以上であり、凡そ４５％以上であってもよく、凡そ５０％以上でもよく、凡そ６５％以上でもよく、凡そ７５％以上でもよい。層間シート（典型的には、基材レス粘着シートの形態の層間シート）のゲル分率も上記で例示した範囲とすることが好ましい。ゲル分率は、ベースポリマーの分子量や分子構造、濃度、架橋度等により調節することができる。ゲル分率は下記の方法で測定される。 (Gel fraction)
The gel fraction of the viscoelastic layer V 1 was, it is appropriately set depending on the intended use and mode of use, etc., but is not limited to a specific range. The gel fraction is, for example, about 99% or less, and about 97% or less is appropriate. From the viewpoint of facilitating a good balance between high refractive index and adhesive properties, in some preferred embodiments, the gel fraction is about 95% or less, more preferably about 92% or less (for example, about 90% or less). Can be. The fact that the gel fraction is not too high appropriately follows the unevenness that may exist on the surface of the adherend (for example, the uneven structure provided for the purpose of improving the light extraction efficiency in the light emitting device), and satisfactorily follows. It is also preferable from the viewpoint of close contact. In some embodiments, the gel fraction may be approximately 88% or less, approximately 75% or less, or approximately 65% or less. Further, the gel fraction is, for example, about 10% or more, and about 20% or more, from the viewpoint of imparting appropriate cohesiveness to the pressure-sensitive adhesive and appropriately expressing the adhesive characteristics, and is about 20% or more. It may be 30% or more. From the viewpoint of deformation resistance of the viscoelastic layer V 1 (prevention of air bubbles due to pressure squeeze out and foreign matter biting, etc.), the gel fraction is preferably about 30% or more, more preferably about 40% or more. , About 45% or more, about 50% or more, about 65% or more, or about 75% or more. The gel fraction of the interlayer sheet (typically, the interlayer sheet in the form of a substrate-less adhesive sheet) is also preferably in the range exemplified above. The gel fraction can be adjusted by adjusting the molecular weight, molecular structure, concentration, degree of cross-linking, etc. of the base polymer. The gel fraction is measured by the following method.

　　［ゲル分率の測定］
　所定量のサンプル（重量Ｗg1）を平均孔径０．２μｍの多孔質ポリテトラフルオロエチレン膜（重量Ｗg2）で巾着状に包み、口をタコ糸（重量Ｗg3）で縛る。上記多孔質ポリテトラフルオロエチレン（ＰＴＦＥ）膜としては、日東電工社から入手可能な商品名「ニトフロン（登録商標）ＮＴＦ１１２２」（平均孔径０．２μｍ、気孔率７５％、厚さ８５μｍ）またはその相当品を使用する。
　この包みを十分量の酢酸エチルに浸し、室温（典型的には２３℃）で７日間保持して粘着剤中のゾル分のみを上記膜外に溶出させた後、上記包みを取り出して外表面に付着している酢酸エチルを拭き取り、該包みを１３０℃で２時間乾燥させ、該包みの重量（Ｗg4）を測定する。ゲル分率は、各値を以下の式に代入することにより求められる。
　　　　ゲル分率（％）＝［（Ｗg4－Ｗg2－Ｗg3）／Ｗg1］×１００ [Measurement of gel fraction]
A predetermined amount of sample (weight Wg 1 ) is wrapped in a porous polytetrafluoroethylene membrane (weight Wg 2 ) having an average pore size of 0.2 μm in a purse-like shape, and the mouth is tied with octopus thread (weight Wg 3 ). As the porous polytetrafluoroethylene (PTFE) film, the trade name "Nitoflon (registered trademark) NTF1122" (average pore diameter 0.2 μm, porosity 75%, thickness 85 μm) available from Nitto Denko Co., Ltd. or its equivalent Use the item.
After immersing this package in a sufficient amount of ethyl acetate and holding it at room temperature (typically 23 ° C.) for 7 days to elute only the sol component in the adhesive to the outside of the film, the package is taken out and the outer surface is removed. The ethyl acetate adhering to the package is wiped off, the package is dried at 130 ° C. for 2 hours, and the weight of the package (Wg 4 ) is measured. The gel fraction can be obtained by substituting each value into the following equation.
Gel fraction (%) = [(Wg 4- Wg 2- Wg 3 ) / Wg 1 ] x 100

　ここに開示される層間シートが第１粘着面と第２粘着面を有する両面粘着シートの形態であって、第１粘着面が粘着剤層Ｖ１により構成され、第２粘着面が粘着剤層Ｖ２により構成されている場合、第１粘着面を構成する粘弾性層Ｖ１のゲル分率と、第２粘着面を構成する粘弾性層Ｖ２のゲル分率とは、同程度であってもよく、異なっていてもよい。いくつかの態様において、粘弾性層Ｖ２のゲル分率を粘弾性層Ｖ１のゲル分率より低くすることができる。かかる構成によると、相対的に低ゲル分率である粘弾性層Ｖ２の寄与により、層間シートの柔軟性を高めやすい。このことによって、粘弾性層Ｖ１の高屈折率化と層間シートの柔軟性とを好適に両立する層間シートが提供され得る。 In the form of a double-sided pressure-sensitive adhesive sheet having an interlayer sheet disclosed herein is the first adhesive surface and a second adhesive surface, a first adhesive surface is constituted by the pressure-sensitive adhesive layer V 1, the second adhesive surface adhesive layer When composed of V 2 , the gel fraction of the viscoelastic layer V 1 constituting the first adhesive surface and the gel fraction of the viscoelastic layer V 2 constituting the second adhesive surface are about the same. It may be different. In some embodiments, the gel fraction of the viscoelastic layer V 2 can be lower than the gel fraction of the viscoelastic layer V 1. According to such a configuration, due to the contribution of the relatively viscoelastic layer V 2 is a low gel fraction, likely increase the flexibility of the interlayer sheet. This allows the interlayer sheet to suitably achieve both flexibility of increasing index of refraction and the interlayer sheet of the viscoelastic layer V 1 is may be provided.

　ここに開示される技術のいくつかの態様において、粘弾性層Ｖ１を構成する粘着剤のｔａｎδのピーク温度は、凡そ－５０℃以上であることが好ましく、また、凡そ５０℃以下であることが好ましい。ここで、粘着剤のｔａｎδ（損失正接）とは、該粘着剤の貯蔵弾性率Ｇ’に対する損失弾性率Ｇ”の比をいう。すなわち、ｔａｎδ＝Ｇ”／Ｇ’である。粘着剤のｔａｎδは、厚さ約２ｍｍ、直径７．９ｍｍの円盤状の粘着剤サンプルをパラレルプレートで挟み込み、粘弾性試験装置を用いて周波数１Ｈｚのせん断歪みを与えながら、測定温度範囲－６０℃～６０℃、昇温速度５℃／分の条件で、せん断モードにより該粘着剤の温度分散試験を行い、その際の貯蔵弾性率Ｇ’（Ｐａ）および損失弾性率Ｇ”（Ｐａ）から次式：ｔａｎδ＝Ｇ”／Ｇ’；により求められる。上記温度範囲におけるｔａｎδの推移から、粘着剤のｔａｎδのピーク温度（以下、Ｔpeakと表記することがある。）が求められる。粘弾性試験装置としては、TA Instruments社製のＡＲＥＳまたはその相当品を用いることができる。 In some embodiments of the technology disclosed herein to a peak temperature of tanδ of adhesive constituting the viscoelastic layer V 1 was, is preferably about -50 ° C. or more, or less about 50 ° C. Is preferable. Here, the tan δ (tangent loss) of the pressure-sensitive adhesive means the ratio of the loss elastic modulus G'to the storage elastic modulus G'of the pressure-sensitive adhesive, that is, tan δ = G'/ G'. The pressure-sensitive adhesive tan δ has a measurement temperature range of -60 ° C while sandwiching a disk-shaped pressure-sensitive adhesive sample with a thickness of about 2 mm and a diameter of 7.9 mm between parallel plates and applying shear strain at a frequency of 1 Hz using a viscoelasticity tester. A temperature dispersion test of the pressure-sensitive adhesive was carried out in a shear mode under the conditions of ~ 60 ° C. and a heating rate of 5 ° C./min. It is calculated by the formula: tan δ = G "/ G';. From the transition of tan δ in the above temperature range, the peak temperature of tan δ of the pressure-sensitive adhesive (hereinafter, may be referred to as Tpeak) can be obtained. As the viscoelasticity test apparatus, ARES manufactured by TA Instruments or an equivalent product thereof can be used.

　いくつかの態様において、粘弾性層Ｖ１のＴpeakは、４５℃以下または３５℃以下であることが有利であり、３０℃以下（例えば２５℃以下）であることが好ましく、２０℃以下でもよく、１５℃以下でもよい。よりＴpeakの低い粘着剤によると、室温域において良好な初期接着性や密着性が得られやすくなる傾向にある。一方、粘着剤のＴpeakが低すぎないことは、粘着剤に適度な凝集性を付与する観点から好ましく、高屈折率化との両立にも適する傾向にある。かかる観点から、いくつかの態様において、粘着剤のＴpeakは、例えば－４０℃以上であってよく、－３０℃以上でもよく、－２０℃以上でもよく、－５℃以上でもよく、５℃以上でもよく、１５℃以上でもよく、さらには２５℃以上でもよい。Ｔpeakが比較的高い粘着剤は、被着体への貼付けに際し、必要に応じて粘着剤と被着体の一方または両方を室温より少し高い程度の温度に加熱する態様で好ましく用いられ得る。粘着剤のＴpeakは、該粘着剤の組成の選択（例えば、ベースポリマーを構成するモノマー成分の組成、屈折率向上剤や可塑化材料の使用有無、種類および使用量の選択）等により調節し得る。
　ここに開示される層間シートが第１粘着面および第２粘着面を有する両面粘着シートの形態である場合、上述した粘着剤のＴpeakは、少なくとも第１粘着面を構成する粘着剤層（好ましくは粘弾性層Ｖ１）に適用されることが好ましく、より好ましくは第１粘着面を構成する粘着剤層および第２粘着面を構成する粘着剤層の両方に適用される。第１粘着面を構成する粘着剤層のＴpeakと第２粘着面を構成する粘着剤層のＴpeakとは、同程度であってもよく、異なっていてもよい。 In some embodiments, Tpeak of the viscoelastic layer V 1 was, is advantageously at 45 ° C. or less, or 35 ° C. or less, preferably from 30 ° C. or less (e.g., 25 ° C. or less) may be at 20 ° C. or less , 15 ° C. or lower. Adhesives with a lower Tpeak tend to provide good initial adhesiveness and adhesion in the room temperature range. On the other hand, it is preferable that the Tpeak of the pressure-sensitive adhesive is not too low from the viewpoint of imparting appropriate cohesiveness to the pressure-sensitive adhesive, and it tends to be suitable for both high refractive index and high refractive index. From this point of view, in some embodiments, the Tpeak of the pressure-sensitive adhesive may be, for example, −40 ° C. or higher, −30 ° C. or higher, −20 ° C. or higher, −5 ° C. or higher, 5 ° C. or higher. However, it may be 15 ° C. or higher, and further may be 25 ° C. or higher. A pressure-sensitive adhesive having a relatively high Tpeak can be preferably used in an embodiment in which one or both of the pressure-sensitive adhesive and the adherend are heated to a temperature slightly higher than room temperature, if necessary, when the pressure-sensitive adhesive is attached to the adherend. The Tpeak of the pressure-sensitive adhesive can be adjusted by selecting the composition of the pressure-sensitive adhesive (for example, the composition of the monomer components constituting the base polymer, the presence or absence of a refractive index improver or a thermoplastic material, the type and the amount used), and the like. ..
When the interlayer sheet disclosed herein is in the form of a double-sided pressure-sensitive adhesive sheet having a first pressure-sensitive adhesive surface and a second pressure-sensitive adhesive surface, the Tpeak of the above-mentioned pressure-sensitive adhesive is a pressure-sensitive adhesive layer (preferably) constituting at least the first pressure-sensitive adhesive surface. it is preferable to apply the viscoelastic layer V 1), more preferably it is applied to both the pressure-sensitive adhesive layer constituting the pressure-sensitive adhesive layer and the second adhesive surface constituting the first adhesive surface. The Tpeak of the pressure-sensitive adhesive layer forming the first adhesive surface and the Tpeak of the pressure-sensitive adhesive layer forming the second adhesive surface may be the same or different.

＜粘弾性層Ｖ１＞
　（ベースポリマー）
　ここに開示される技術において、粘着剤層Ｖ１を構成する粘着剤の種類は特に限定されない。上記粘着剤は、粘着剤の分野において用いられ得るアクリル系ポリマー、ゴム系ポリマー（例えば天然ゴム、合成ゴム、これらの混合物等）、ポリエステル系ポリマー、ウレタン系ポリマー、ポリエーテル系ポリマー、シリコーン系ポリマー、ポリアミド系ポリマー、フッ素系ポリマー等の各種ゴム状ポリマーの１種または２種以上を粘着性ポリマー（粘着剤を形づくる構造ポリマーという意味で、以下「ベースポリマー」ともいう。）として含むものであり得る。粘着性能やコスト等の観点から、アクリル系ポリマーまたはゴム系ポリマーをベースポリマーとして含む粘着剤を好ましく採用し得る。なかでもアクリル系ポリマーをベースポリマーとする粘着剤（アクリル系粘着剤）が好ましい。ここに開示される技術は、アクリル系粘着剤を用いる態様で好ましく実施される。 <Viscoelastic layer V 1 >
(Base polymer)
In the technique disclosed herein, the type of the pressure-sensitive adhesive constituting the pressure-sensitive adhesive layer V 1 is not particularly limited. The pressure-sensitive adhesive may be an acrylic polymer, a rubber-based polymer (for example, natural rubber, synthetic rubber, a mixture thereof, etc.), a polyester-based polymer, a urethane-based polymer, a polyether polymer, or a silicone-based polymer that can be used in the field of pressure-sensitive adhesives. , One or more of various rubber-like polymers such as polyamide polymers and fluoropolymers are included as adhesive polymers (hereinafter, also referred to as "base polymers" in the sense of structural polymers forming adhesives). obtain. From the viewpoint of adhesive performance, cost, and the like, a pressure-sensitive adhesive containing an acrylic polymer or a rubber-based polymer as a base polymer can be preferably adopted. Of these, a pressure-sensitive adhesive (acrylic pressure-sensitive adhesive) using an acrylic polymer as a base polymer is preferable. The technique disclosed herein is preferably carried out in an embodiment using an acrylic pressure-sensitive adhesive.

　以下、粘着剤層Ｖ１がアクリル系粘着剤により構成されている層間シート、すなわちアクリル系粘着剤層を有する層間シートについて主に説明するが、ここに開示される層間シートにおける粘着剤層Ｖ１をアクリル系粘着剤層に限定する意図ではない。 Hereinafter, an interlayer sheet in which the pressure-sensitive adhesive layer V 1 is composed of an acrylic pressure-sensitive adhesive, that is, an interlayer sheet having an acrylic pressure-sensitive adhesive layer will be mainly described, but the pressure-sensitive adhesive layer V 1 in the interlayer sheet disclosed herein will be mainly described. Is not intended to be limited to the acrylic pressure-sensitive adhesive layer.

　なお、この明細書において、粘着剤の「ベースポリマー」とは、該粘着剤に含まれるゴム状ポリマーの主成分をいい、このこと以外、何ら限定的に解釈されるものではない。上記ゴム状ポリマーとは、室温付近の温度域においてゴム弾性を示すポリマーをいう。また、この明細書において「主成分」とは、特記しない場合、５０重量％を超えて含まれる成分を指す。
　また、この明細書において「アクリル系ポリマー」とは、該ポリマーを構成するモノマー単位として、１分子中に少なくとも１つの（メタ）アクリロイル基を有するモノマーに由来するモノマー単位を含む重合物をいう。以下、１分子中に少なくとも１つの（メタ）アクリロイル基を有するモノマーを「アクリル系モノマー」ともいう。したがって、この明細書におけるアクリル系ポリマーは、アクリル系モノマーに由来するモノマー単位を含むポリマーとして定義される。アクリル系ポリマーの典型例として、該アクリル系ポリマーの合成に用いられる全モノマーのうちアクリル系モノマーの割合が５０重量％超（好ましくは７０重量％超、例えば９０重量％超）であるポリマーが挙げられる。
　また、この明細書において「（メタ）アクリロイル」とは、アクリロイルおよびメタクリロイルを包括的に指す意味である。同様に、「（メタ）アクリレート」とはアクリレートおよびメタクリレートを、「（メタ）アクリル」とはアクリルおよびメタクリルを、それぞれ包括的に指す意味である。したがって、ここでいうアクリル系モノマーの概念には、アクリロイル基を有するモノマー（アクリル系モノマー）とメタクリロイル基を有するモノマー（メタクリル系モノマー）との両方が包含され得る。 In this specification, the "base polymer" of the pressure-sensitive adhesive refers to the main component of the rubber-like polymer contained in the pressure-sensitive adhesive, and is not interpreted in any limitation other than this. The rubber-like polymer refers to a polymer that exhibits rubber elasticity in a temperature range near room temperature. Further, in this specification, the “main component” refers to a component contained in an amount of more than 50% by weight unless otherwise specified.
Further, in the present specification, the "acrylic polymer" refers to a polymer containing a monomer unit derived from a monomer having at least one (meth) acryloyl group in one molecule as a monomer unit constituting the polymer. Hereinafter, a monomer having at least one (meth) acryloyl group in one molecule is also referred to as an “acrylic monomer”. Therefore, the acrylic polymer in this specification is defined as a polymer containing a monomer unit derived from an acrylic monomer. A typical example of the acrylic polymer is a polymer in which the proportion of the acrylic monomer in the total monomers used in the synthesis of the acrylic polymer is more than 50% by weight (preferably more than 70% by weight, for example, more than 90% by weight). Be done.
Further, in this specification, "(meth) acryloyl" means a comprehensive reference to acryloyl and methacryloyl. Similarly, "(meth) acrylate" means acrylate and methacrylate, and "(meth) acrylic" means acrylic and methacrylic, respectively. Therefore, the concept of the acrylic monomer here may include both a monomer having an acryloyl group (acrylic monomer) and a monomer having a methacryloyl group (methacryl monomer).

　（アクリル系ポリマー（Ａ））
　ここに開示される層間シートは、屈折率が１．５７０以上であり、２５℃における貯蔵弾性率Ｇ’Ｖ１が３０ｋＰａ～７００ｋＰａであり、全光線透過率が８６％以上であり、かつヘイズ値が１．０％以下であるアクリル系粘着剤層を含む態様で好ましく実施し得る。上記アクリル系粘着剤層のベースポリマーであるアクリル系ポリマーとしては、該アクリル系ポリマーを構成するモノマー成分として芳香環含有モノマー（ｍ１）を含むものが好ましい。すなわち、芳香環含有モノマー（ｍ１）をモノマー単位として含むアクリル系ポリマーが好ましい。以下、かかるアクリル系ポリマーを「アクリル系ポリマー（Ａ）」ともいう。ここで、本明細書において「アクリル系ポリマーを構成するモノマー成分」とは、あらかじめ形成された重合物（オリゴマーであり得る。）の形態で粘着剤組成物に含まれるか、未重合のモノマーの形態で粘着剤組成物に含まれるかを問わず、該粘着剤組成物から形成される粘着剤中においてアクリル系ポリマーの繰返し単位を構成するモノマーを意味する。すなわち、アクリル系ポリマーを構成するモノマー成分は、重合物、未重合物、部分重合物のいずれの形態で上記粘着剤組成物に含まれていてもよい。粘着剤組成物の調製容易性等の観点から、いくつかの態様において、モノマー成分の実質的に全部（例えば９５重量％以上、好ましくは９９重量％以上）を重合物の形態で含む粘着剤組成物が好ましい。モノマー成分の実質的に全部を重合物の形態で含む粘着剤組成物は、歪みや反りの少ない層間シートを形成しやすいという観点からも好ましい。 (Acrylic polymer (A))
Interlayer sheet disclosed herein, the refractive index is at 1.570 or more, the storage modulus G 'V1 is 30 kPa ~ 700 kPa at 25 ° C., a total light transmittance is not less than 86%, and haze value of It can be preferably carried out in an embodiment including an acrylic pressure-sensitive adhesive layer of 1.0% or less. As the acrylic polymer that is the base polymer of the acrylic pressure-sensitive adhesive layer, those containing an aromatic ring-containing monomer (m1) as a monomer component constituting the acrylic polymer are preferable. That is, an acrylic polymer containing an aromatic ring-containing monomer (m1) as a monomer unit is preferable. Hereinafter, such an acrylic polymer is also referred to as an "acrylic polymer (A)". Here, in the present specification, the "monomer component constituting the acrylic polymer" is a monomer contained in the pressure-sensitive adhesive composition in the form of a preformed polymer (which may be an oligomer) or a non-polymerized monomer. Regardless of whether it is contained in the pressure-sensitive adhesive composition in its form, it means a monomer constituting a repeating unit of an acrylic polymer in a pressure-sensitive adhesive formed from the pressure-sensitive adhesive composition. That is, the monomer component constituting the acrylic polymer may be contained in the pressure-sensitive adhesive composition in any form of a polymer, a non-polymer, or a partial polymer. From the viewpoint of ease of preparation of the pressure-sensitive adhesive composition, in some embodiments, a pressure-sensitive adhesive composition containing substantially all of the monomer components (for example, 95% by weight or more, preferably 99% by weight or more) in the form of a polymer. The thing is preferable. A pressure-sensitive adhesive composition containing substantially all of the monomer components in the form of a polymer is preferable from the viewpoint of easily forming an interlayer sheet with less distortion and warpage.

　（モノマー（ｍ１））
　モノマー（ｍ１）としては、１分子中に少なくとも１つの芳香環と少なくとも１つのエチレン性不飽和基とを含む化合物が用いられる。モノマー（ｍ１）としては、かかる化合物の１種を単独でまたは２種以上を組み合わせて用いることができる。 (Monomer (m1))
As the monomer (m1), a compound containing at least one aromatic ring and at least one ethylenically unsaturated group in one molecule is used. As the monomer (m1), one of the compounds may be used alone or in combination of two or more.

　上記エチレン性不飽和基の例としては、（メタ）アクリロイル基、ビニル基、（メタ）アリル基等が挙げられる。重合反応性の観点から（メタ）アクリロイル基が好ましく、柔軟性や粘着性の観点からアクリロイル基がより好ましい。粘着剤の柔軟性低下を抑制する観点から、モノマー（ｍ１）としては、１分子中に含まれるエチレン性不飽和基の数が１である化合物（すなわち、単官能モノマー）が好ましく用いられる。 Examples of the ethylenically unsaturated group include (meth) acryloyl group, vinyl group, (meth) allyl group and the like. A (meth) acryloyl group is preferable from the viewpoint of polymerization reactivity, and an acryloyl group is more preferable from the viewpoint of flexibility and adhesiveness. From the viewpoint of suppressing a decrease in the flexibility of the pressure-sensitive adhesive, a compound (that is, a monofunctional monomer) in which the number of ethylenically unsaturated groups contained in one molecule is 1 is preferably used as the monomer (m1).

　モノマー（ｍ１）として用いられる化合物１分子に含まれる芳香環の数は、１でもよく、２以上でもよい。モノマー（ｍ１）に含まれる芳香環の数の上限は特に制限されず、例えば１６以下であり得る。いくつかの態様において、アクリル系ポリマー（Ａ）の調製容易性や粘着剤の透明性の観点から、上記芳香環の数は、例えば１２以下であってよく、８以下であることが好ましく、６以下であることがより好ましく、５以下でもよく、４以下でもよく、３以下でもよく、２以下でもよい。 The number of aromatic rings contained in one molecule of the compound used as the monomer (m1) may be 1 or 2 or more. The upper limit of the number of aromatic rings contained in the monomer (m1) is not particularly limited, and may be 16 or less, for example. In some embodiments, the number of aromatic rings may be, for example, 12 or less, preferably 8 or less, from the viewpoint of ease of preparation of the acrylic polymer (A) and transparency of the pressure-sensitive adhesive. More preferably, it may be 5 or less, 4 or less, 3 or less, or 2 or less.

　モノマー（ｍ１）として用いられる化合物の有する芳香環は、例えばベンゼン環（ビフェニル構造やフルオレン構造の一部を構成するベンゼン環であり得る。）；ナフタレン環、インデン環、アズレン環、アントラセン環、フェナントレン環の縮合環；等の炭素環であってもよく、例えばピリジン環、ピリミジン環、ピリダジン環、ピラジン環、トリアジン環、ピロール環、ピラゾール環、イミダゾール環、トリアゾール環、オキサゾール環、イソオキサゾール環、チアゾール環、チオフェン環；等の複素環であってもよい。上記複素環において環構成原子として含まれるヘテロ原子は、例えば窒素、硫黄および酸素からなる群から選択される１または２以上であり得る。いくつかの態様において、上記複素環を構成するヘテロ原子は、窒素および硫黄の一方または両方であり得る。モノマー（ｍ１）は、例えばジナフトチオフェン構造のように、１または２以上の炭素環と１または２以上の複素環とが縮合した構造を有していてもよい。 The aromatic ring of the compound used as the monomer (m1) is, for example, a benzene ring (which may be a benzene ring forming a part of a biphenyl structure or a fluorene structure); a naphthalene ring, an inden ring, an azulene ring, an anthracene ring, and a phenanthrene. It may be a carbon ring such as a fused ring of a ring; for example, a pyridine ring, a pyrimidine ring, a pyridazine ring, a pyrazine ring, a triazine ring, a pyrrole ring, a pyrazole ring, an imidazole ring, a triazole ring, an oxazole ring, an isooxazole ring, and the like. It may be a heterocycle such as a thiazole ring or a thiophene ring. The heteroatom contained as a ring-constituting atom in the heterocycle may be one or more selected from the group consisting of, for example, nitrogen, sulfur and oxygen. In some embodiments, the heteroatom constituting the heterocycle can be one or both of nitrogen and sulfur. The monomer (m1) may have a structure in which one or more carbon rings and one or more heterocycles are condensed, for example, a dinaphthothiophene structure.

　上記芳香環（好ましくは炭素環）は、環構成原子上に１または２以上の置換基を有していてもよく、置換基を有していなくてもよい。置換基を有する場合、該置換基としては、アルキル基、アルコキシ基、アリールオキシ基、水酸基、ハロゲン原子（フッ素原子、塩素原子、臭素原子等）、ヒドロキシアルキル基、ヒドロキシアルキルオキシ基、グリシジルオキシ基等が例示されるが、これらに限定されない。炭素原子を含む置換基において、該置換基に含まれる炭素原子の数は、好ましくは１～４であり、より好ましくは１～３であり、例えば１または２であり得る。いくつかの態様において、上記芳香環は、環構成原子上に置換基を有しないか、アルキル基、アルコキシ基およびハロゲン原子（例えば臭素原子）からなる群から選択される１または２以上の置換基を有する芳香環であり得る。なお、モノマー（ｍ１）の有する芳香環がその環構成原子上に置換基を有するとは、該芳香環が、エチレン性不飽和基を有する置換基以外の置換基を有することをいう。 The aromatic ring (preferably a carbon ring) may have one or more substituents on the ring-constituting atom, and may not have a substituent. When it has a substituent, the substituent includes an alkyl group, an alkoxy group, an aryloxy group, a hydroxyl group, a halogen atom (fluorine atom, chlorine atom, bromine atom, etc.), a hydroxyalkyl group, a hydroxyalkyloxy group, and a glycidyloxy group. Etc., but are not limited thereto. In the substituent containing a carbon atom, the number of carbon atoms contained in the substituent is preferably 1 to 4, more preferably 1 to 3, and may be, for example, 1 or 2. In some embodiments, the aromatic ring has one or more substituents that do not have a substituent on the ring-constituting atom or are selected from the group consisting of an alkyl group, an alkoxy group and a halogen atom (eg, a bromine atom). It can be an aromatic ring having. The fact that the aromatic ring of the monomer (m1) has a substituent on its ring-constituting atom means that the aromatic ring has a substituent other than the substituent having an ethylenically unsaturated group.

　芳香環とエチレン性不飽和基とは、直接結合していてもよく、リンキング基を介して結合していてもよい。上記リンキング基は、例えば、アルキレン基、オキシアルキレン基、ポリ（オキシアルキレン）基、フェニル基、アルキルフェニル基、アルコキシフェニル基、これらの基において１または２以上の水素原子が水酸基で置換された構造の基（例えば、ヒドロキシアルキレン基）、オキシ基（－Ｏ－基）、チオオキシ基（－Ｓ－基）、等から選択される１または２以上の構造を含む基であり得る。いくつかの態様において、芳香環とエチレン性不飽和基とが、直接結合しているか、またはアルキレン基、オキシアルキレン基およびポリ（オキシアルキレン）基からなる群から選択されるリンキング基を介して結合している構造の芳香環含有モノマーを好ましく採用し得る。上記アルキレン基および上記オキシアルキレン基における炭素原子数は、好ましくは１～４であり、より好ましくは１～３であり、例えば１または２であり得る。上記ポリ（オキシアルキレン）基におけるオキシアルキレン単位の繰り返し数は、例えば２～３であり得る。 The aromatic ring and the ethylenically unsaturated group may be directly bonded or may be bonded via a linking group. The linking group is, for example, an alkylene group, an oxyalkylene group, a poly (oxyalkylene) group, a phenyl group, an alkylphenyl group, an alkoxyphenyl group, and a structure in which one or more hydrogen atoms are substituted with hydroxyl groups in these groups. It can be a group containing one or more structures selected from the group (eg, hydroxyalkylene group), oxy group (—O— group), thiooxy group (—S— group), and the like. In some embodiments, the aromatic ring and the ethylenically unsaturated group are directly bonded or bonded via a linking group selected from the group consisting of alkylene groups, oxyalkylene groups and poly (oxyalkylene) groups. An aromatic ring-containing monomer having a structure having a structure can be preferably adopted. The number of carbon atoms in the alkylene group and the oxyalkylene group is preferably 1 to 4, more preferably 1 to 3, and may be, for example, 1 or 2. The number of repetitions of the oxyalkylene unit in the poly (oxyalkylene) group can be, for example, 2 to 3.

　モノマー（ｍ１）として好ましく採用し得る化合物の例として、芳香環含有（メタ）アクリレートおよび芳香環含有ビニル化合物が挙げられる。芳香環含有（メタ）アクリレートおよび芳香環含有ビニル化合物は、それぞれ、１種を単独でまたは２種以上を組み合わせて用いることができる。１種または２種以上の芳香環含有（メタ）アクリレートと、１種または２種以上の芳香環含有ビニル化合物とを組み合わせて用いてもよい。 Examples of compounds that can be preferably used as the monomer (m1) include aromatic ring-containing (meth) acrylates and aromatic ring-containing vinyl compounds. The aromatic ring-containing (meth) acrylate and the aromatic ring-containing vinyl compound can be used individually by 1 type or in combination of 2 or more types, respectively. One or more aromatic ring-containing (meth) acrylates may be used in combination with one or more aromatic ring-containing vinyl compounds.

　アクリル系ポリマー（Ａ）を構成するモノマー成分におけるモノマー（ｍ１）の含有量は、特に制限されず、所望の屈折率と粘着特性（例えば剥離強度、柔軟性等）および／または光学特性（例えば全光線透過性、ヘイズ値等）とを両立する粘着剤層を実現し得るように設定することができる。いくつかの態様において、上記モノマー成分におけるモノマー（ｍ１）の含有量は、例えば３０重量％以上であってよく、好ましくは５０重量％以上であり、６０重量％以上でもよく、７０重量％以上でもよい。より高い屈折率を得やすくする観点から、いくつかの好ましい態様において、上記モノマー（ｍ１）の含有量は、例えば７０重量％超であってよく、７５重量％以上でもよく、８０重量％以上でもよく、８５重量％以上でもよく、９０重量％以上でもよく、９５重量％以上でもよい。上記モノマー成分におけるモノマー（ｍ１）の含有量の上限は１００重量％である。高屈折率と粘着特性および／または光学特性とをバランスよく両立する観点から、上記モノマー（ｍ１）の含有量は、１００重量％未満とすることが有利であり、例えば凡そ９９重量％以下であることが好ましく、９８重量％以下であることがより好ましく、９７重量％以下でもよく、９６重量％以下でもよい。いくつかの態様において、上記モノマー（ｍ１）の含有量は、９３重量％以下でもよく、９０重量％以下でもよく、８０重量％以下でもよく、７５重量％以下でもよい。より粘着特性および／または光学特性を重視するいくつかの態様において、上記モノマー成分における上記モノマー（ｍ１）の含有量は、７０重量％以下でもよく、６０重量％以下でもよく、４５重量％以下でもよい。 The content of the monomer (m1) in the monomer component constituting the acrylic polymer (A) is not particularly limited, and the desired refractive index and adhesive properties (for example, peel strength, flexibility, etc.) and / or optical properties (for example, all) are not particularly limited. It can be set so as to realize a pressure-sensitive adhesive layer that has both light transmittance, haze value, etc.). In some embodiments, the content of the monomer (m1) in the monomer component may be, for example, 30% by weight or more, preferably 50% by weight or more, 60% by weight or more, or 70% by weight or more. good. From the viewpoint of facilitating the acquisition of a higher refractive index, in some preferred embodiments, the content of the monomer (m1) may be, for example, more than 70% by weight, 75% by weight or more, or 80% by weight or more. It may be 85% by weight or more, 90% by weight or more, or 95% by weight or more. The upper limit of the content of the monomer (m1) in the above-mentioned monomer component is 100% by weight. From the viewpoint of achieving both high refractive index and adhesive properties and / or optical properties in a well-balanced manner, it is advantageous that the content of the monomer (m1) is less than 100% by weight, for example, about 99% by weight or less. It is preferably 98% by weight or less, 97% by weight or less, and 96% by weight or less. In some embodiments, the content of the monomer (m1) may be 93% by weight or less, 90% by weight or less, 80% by weight or less, or 75% by weight or less. In some embodiments where more adhesive and / or optical properties are emphasized, the content of the monomer (m1) in the monomer component may be 70% by weight or less, 60% by weight or less, or 45% by weight or less. good.

　ここに開示される技術のいくつかの態様において、モノマー（ｍ１）としては、高い高屈折率化効果が得られやすいことから、１分子中に２以上の芳香環（好ましくは炭素環）を有するモノマーを好ましく採用し得る。１分子内に２以上の芳香環を有するモノマー（以下、「芳香環複数含有モノマー」ともいう。）の例としては、２以上の非縮合芳香環がリンキング基を介して結合した構造を有するモノマー、２以上の非縮合芳香環が直接（すなわち、他の原子を介さずに）化学結合した構造を有するモノマー、縮合芳香環構造を有するモノマー、フルオレン構造を有するモノマー、ジナフトチオフェン構造を有するモノマー、ジベンゾチオフェン構造を有するモノマー、等が挙げられる。芳香環複数含有モノマーは、１種を単独でまたは２種以上を組み合わせて用いることができる。 In some aspects of the technique disclosed herein, the monomer (m1) has two or more aromatic rings (preferably carbon rings) in one molecule because a high refractive index increasing effect can be easily obtained. Monomers can be preferably used. As an example of a monomer having two or more aromatic rings in one molecule (hereinafter, also referred to as “monomer containing a plurality of aromatic rings”), a monomer having a structure in which two or more non-condensed aromatic rings are bonded via a linking group. A monomer having a structure in which two or more non-condensed aromatic rings are chemically bonded directly (that is, without interposing other atoms), a monomer having a condensed aromatic ring structure, a monomer having a fluorene structure, and a monomer having a dinaphthothiophene structure. , Monomers having a dibenzothiophene structure, and the like. The monomer containing a plurality of aromatic rings may be used alone or in combination of two or more.

　上記リンキング基は、例えばオキシ基（－Ｏ－）、チオオキシ基（－Ｓ－）、オキシアルキレン基（例えば－Ｏ－（ＣＨ２）ｎ－基、ここでｎは１～３、好ましくは１）、チオオキシアルキレン基（例えば－Ｓ－（ＣＨ２）ｎ－基、ここでｎは１～３、好ましくは１）、直鎖アルキレン基（すなわち－（ＣＨ２）ｎ－基、ここでｎは１～６、好ましくは１～３）、上記オキシアルキレン基、上記チオオキシアルキレン基および上記直鎖アルキレン基におけるアルキレン基が部分ハロゲン化または完全ハロゲン化された基、等であり得る。粘着剤の柔軟性等の観点から、上記リンキング基の好適例として、オキシ基、チオオキシ基、オキシアルキレン基および直鎖アルキレン基が挙げられる。２以上の非縮合芳香環がリンキング基を介して結合した構造を有するモノマーの具体例としては、フェノキシベンジル（メタ）アクリレート（例えば、ｍ－フェノキシベンジル（メタ）アクリレート）、チオフェノキシベンジル（メタ）アクリレート、ベンジルベンジル（メタ）アクリレート、等が挙げられる。 The linking group is, for example, an oxy group (-O-), a thiooxy group (-S-), an oxyalkylene group (for example, -O- (CH 2 ) n- group, where n is 1 to 3, preferably 1). , Thiooxyalkylene groups (eg-S- (CH 2 ) n -groups, where n is 1-3, preferably 1), linear alkylene groups (ie-(CH 2 ) n -groups, where n is 1 to 6, preferably 1 to 3), the oxyalkylene group, the thiooxyalkylene group, and the group in which the alkylene group in the linear alkylene group is partially halogenated or completely halogenated, and the like can be used. From the viewpoint of the flexibility of the pressure-sensitive adhesive, preferred examples of the linking group include an oxy group, a thiooxy group, an oxyalkylene group and a linear alkylene group. Specific examples of the monomer having a structure in which two or more non-condensed aromatic rings are bonded via a linking group include phenoxybenzyl (meth) acrylate (for example, m-phenoxybenzyl (meth) acrylate) and thiophenoxybenzyl (meth). Examples thereof include acrylate, benzylbenzyl (meth) acrylate, and the like.

　上記２以上の非縮合芳香環が直接化学結合した構造を有するモノマーは、例えばビフェニル構造含有（メタ）アクリレート、トリフェニル構造含有（メタ）アクリレート、ビニル基含有ビフェニル等であり得る。具体例としては、ｏ－フェニルフェノール（メタ）アクリレート、ビフェニルメチル（メタ）アクリレート等が挙げられる。 The monomer having a structure in which the above two or more non-condensed aromatic rings are directly chemically bonded may be, for example, a biphenyl structure-containing (meth) acrylate, a triphenyl structure-containing (meth) acrylate, a vinyl group-containing biphenyl, or the like. Specific examples include o-phenylphenol (meth) acrylate and biphenylmethyl (meth) acrylate.

　上記縮合芳香環構造を有するモノマーの例としては、ナフタレン環含有（メタ）アクリレート、アントラセン環含有（メタ）アクリレート、ビニル基含有ナフタレン、ビニル基含有アントラセン、等が挙げられる。具体例としては、１－ナフチルメチル（メタ）アクリレート（別名：１－ナフタレンメチル（メタ）アクリレート）、ヒドロキシエチル化β－ナフトールアクリレート、２－ナフトエチル（メタ）アクリレート、２－ナフトキシエチルアクリレート、２－（４－メトキシ－１－ナフトキシ）エチル（メタ）アクリレート、等が挙げられる。 Examples of the monomer having a condensed aromatic ring structure include naphthalene ring-containing (meth) acrylate, anthracene ring-containing (meth) acrylate, vinyl group-containing naphthalene, and vinyl group-containing anthracene. Specific examples include 1-naphthylmethyl (meth) acrylate (also known as 1-naphthalenemethyl (meth) acrylate), hydroxyethylated β-naphthol acrylate, 2-naphthoethyl (meth) acrylate, 2-naphthoxyethyl acrylate, 2 -(4-Methoxy-1-naphthoxy) ethyl (meth) acrylate, etc. may be mentioned.

　上記フルオレン構造を有するモノマーの具体例としては、９，９－ビス（４－ヒドロキシフェニル）フルオレン（メタ）アクリレート、９，９－ビス［４－（２－ヒドロキシエトキシ）フェニル］フルオレン（メタ）アクリレート等が挙げられる。なお、フルオレン構造を有するモノマーは、２つのベンゼン環が直接化学結合した構造部分を含むため、上記２以上の非縮合芳香環が直接化学結合した構造を有するモノマーの概念に包含される。 Specific examples of the monomer having a fluorene structure include 9,9-bis (4-hydroxyphenyl) fluorene (meth) acrylate and 9,9-bis [4- (2-hydroxyethoxy) phenyl] fluorene (meth) acrylate. And so on. Since the monomer having a fluorene structure contains a structural portion in which two benzene rings are directly chemically bonded, it is included in the concept of a monomer having a structure in which two or more non-condensed aromatic rings are directly chemically bonded.

　上記ジナフトチオフェン構造を有するモノマーとしては、（メタ）アクリロイル基含有ジナフトチオフェン、ビニル基含有ジナフトチオフェン、（メタ）アリル基含有ジナフトチオフェン、等が挙げられる。具体例としては、（メタ）アクリロイルオキシメチルジナフトチオフェン（例えば、ジナフトチオフェン環の５位または６位にＣＨ２ＣＨ（Ｒ１）Ｃ（Ｏ）ＯＣＨ２－が結合した構造の化合物。ここで、Ｒ１は水素原子またはメチル基である。）、（メタ）アクリロイルオキシエチルジナフトチオフェン（例えば、ジナフトチオフェン環の５位または６位に、ＣＨ２ＣＨ（Ｒ１）Ｃ（Ｏ）ＯＣＨ（ＣＨ３）－またはＣＨ２ＣＨ（Ｒ１）Ｃ（Ｏ）ＯＣＨ２ＣＨ２－が結合した構造の化合物。ここで、Ｒ１は水素原子またはメチル基である。）、ビニルジナフトチオフェン（例えば、ナフトチオフェン環の５位または６位にビニル基が結合した構造の化合物）、（メタ）アリルオキシジナフトチオフェン、等が挙げられる。なお、ジナフトチオフェン構造を有するモノマーは、ナフタレン構造を含むことにより、またチオフェン環と２つのナフタレン構造とが縮合した構造を有することによっても、上記縮合芳香環構造を有するモノマーの概念に包含される。 Examples of the monomer having a dinaphthophene structure include (meth) acryloyl group-containing dinaphthophene, vinyl group-containing dinaphthophene, and (meth) allyl group-containing dinaphthothiophene. As a specific example, a compound having a structure in which CH 2 CH (R 1 ) C (O) OCH 2- is bound to the 5- or 6-position of the (meth) acryloyloxymethyldinaphthophene ring (for example, the dinaphthophene ring). R 1 is a hydrogen atom or a methyl group), (meth) acryloyloxyethyl dinaphthophene (eg, CH 2 CH (R 1 ) C (O) at the 5th or 6th position of the dinaphthophene ring. A compound having a structure in which OCH (CH 3 ) -or CH 2 CH (R 1 ) C (O) OCH 2 CH 2 -are bound. Here, R 1 is a hydrogen atom or a methyl group), vinyl dinaphthophene. (For example, a compound having a structure in which a vinyl group is bonded to the 5- or 6-position of the naphthophene ring), (meth) allyloxydinaphthophene, and the like. The monomer having a dinaphthophene structure is included in the concept of a monomer having a condensed aromatic ring structure because it contains a naphthalene structure and also has a structure in which a thiophene ring and two naphthalene structures are condensed. NS.

　上記ジベンゾチオフェン構造を有するモノマーとしては、（メタ）アクリロイル基含有ジベンゾチオフェン、ビニル基含有ジベンゾチオフェン、等が挙げられる。なお、ジベンゾチオフェン構造を有するモノマーは、チオフェン環と２つのベンゼン環とが縮合した構造を有することから、上記縮合芳香環構造を有するモノマーの概念に包含される。
　なお、ジナフトチオフェン構造およびジベンゾチオフェン構造は、いずれも、２以上の非縮合芳香環が直接化学結合した構造には該当しない。 Examples of the monomer having a dibenzothiophene structure include (meth) acryloyl group-containing dibenzothiophene, vinyl group-containing dibenzothiophene, and the like. A monomer having a dibenzothiophene structure is included in the concept of a monomer having a condensed aromatic ring structure because it has a structure in which a thiophene ring and two benzene rings are condensed.
Neither the dinaphthothiophene structure nor the dibenzothiophene structure corresponds to a structure in which two or more uncondensed aromatic rings are directly chemically bonded.

　ここに開示される技術におけるモノマー（ｍ１）として、１分子中に１つの芳香環（好ましくは炭素環）を有するモノマーを使用してもよい。１分子中に１つの芳香環を有するモノマーは、例えば、粘着剤の柔軟性の向上や粘着特性の調整、透明性の向上等に役立ち得る。いくつかの態様において、１分子中に１つの芳香環を有するモノマーは、粘着剤の屈折率向上の観点から、芳香環複数含有モノマーと組み合わせて用いることが好ましい。 As the monomer (m1) in the technique disclosed herein, a monomer having one aromatic ring (preferably a carbon ring) in one molecule may be used. A monomer having one aromatic ring in one molecule can be useful for improving the flexibility of the pressure-sensitive adhesive, adjusting the pressure-sensitive adhesive properties, improving the transparency, and the like. In some embodiments, the monomer having one aromatic ring in one molecule is preferably used in combination with a monomer containing a plurality of aromatic rings from the viewpoint of improving the refractive index of the pressure-sensitive adhesive.

　１分子中に１つの芳香環を有するモノマーの例としては、べンジル（メタ）アクリレート、メトキシベンジル（メタ）アクリレート、フェニル（メタ）アクリレート、エトキシ化フェノール（メタ）アクリレート、フェノキシプロピル（メタ）アクリレート、フェノキシブチル（メタ）アクリレート、クレジル（メタ）アクリレート、２－ヒドロキシ－３－フェノキシプロピル（メタ）アクリレート、クロロベンジル（メタ）アクリレート等の、炭素芳香環含有（メタ）アクリレート；２－（４，６－ジブロモ－２－ｓ－ブチルフェノキシ）エチル（メタ）アクリレート、２－（４，６－ジブロモ－２－イソプロピルフェノキシ）エチル（メタ）アクリレート、６－（４，６－ジブロモ－２－ｓ－ブチルフェノキシ）ヘキシル（メタ）アクリレート、６－（４，６－ジブロモ－２－イソプロピルフェノキシ）ヘキシル（メタ）アクリレート、２，６－ジブロモ－４－ノニルフェニルアクリレート、２，６－ジブロモ－４－ドデシルフェニルアクリレート等の、臭素置換芳香環含有（メタ）アクリレート；スチレン、α－メチルスチレン、ビニルトルエン、ｔｅｒｔ－ブチルスチレン等の、炭素芳香環含有ビニル化合物；Ｎ－ビニルピリジン、Ｎ－ビニルピリミジン、Ｎ－ビニルピラジン、Ｎ－ビニルピロール、Ｎ－ビニルイミダゾール、Ｎ－ビニルオキサゾール等の、複素芳香環上にビニル置換基を有する化合物；等が挙げられる。 Examples of monomers having one aromatic ring in one molecule include benzyl (meth) acrylate, methoxybenzyl (meth) acrylate, phenyl (meth) acrylate, ethoxylated phenol (meth) acrylate, and phenoxypropyl (meth) acrylate. , Phenoxybutyl (meth) acrylate, cresyl (meth) acrylate, 2-hydroxy-3-phenoxypropyl (meth) acrylate, chlorobenzyl (meth) acrylate, and other carbon aromatic ring-containing (meth) acrylates; 2- (4, 6-Dibromo-2-s-butylphenoxy) ethyl (meth) acrylate, 2- (4,6-dibromo-2-isopropylphenoxy) ethyl (meth) acrylate, 6- (4,6-dibromo-2-s-) Butylphenoxy) hexyl (meth) acrylate, 6- (4,6-dibromo-2-isopropylphenoxy) hexyl (meth) acrylate, 2,6-dibromo-4-nonylphenyl acrylate, 2,6-dibromo-4-dodecyl Bromine-substituted aromatic ring-containing (meth) acrylates such as phenyl acrylates; carbon aromatic ring-containing vinyl compounds such as styrene, α-methylstyrene, vinyltoluene and tert-butylstyrene; N-vinylpyridine, N-vinylpyrimidine, N. -Compounds having a vinyl substituent on the heteroaromatic ring such as vinylpyrazine, N-vinylpyrrole, N-vinylimidazole, N-vinyloxazole; and the like can be mentioned.

　モノマー（ｍ１）としては、上述のような各種芳香環含有モノマーにおけるエチレン性不飽和基と芳香環との間にオキシエチレン鎖を介在させた構造のモノマーを使用してもよい。このようにエチレン性不飽和基と芳香環との間にオキシエチレン鎖を介在させたモノマーは、元のモノマーのエトキシ化物として把握され得る。上記オキシエチレン鎖におけるオキシエチレン単位（－ＣＨ２ＣＨ２Ｏ－）の繰返し数は、典型的には１～４、好ましくは１～３、より好ましくは１～２であり、例えば１である。エトキシ化された芳香環含有モノマーの具体例としては、エトキシ化ｏ－フェニルフェノール（メタ）アクリレート、エトキシ化ノニルフェノール（メタ）アクリレート、エトキシ化クレゾール（メタ）アクリレート、フェノキシエチル（メタ）アクリレート、フェノキシジエチレングリコールジ（メタ）アクリレート等が挙げられる。 As the monomer (m1), a monomer having a structure in which an oxyethylene chain is interposed between an ethylenically unsaturated group and an aromatic ring in various aromatic ring-containing monomers as described above may be used. A monomer having an oxyethylene chain interposed between an ethylenically unsaturated group and an aromatic ring in this way can be grasped as an ethoxylated product of the original monomer. The number of repetitions of the oxyethylene unit (-CH 2 CH 2 O-) in the oxyethylene chain is typically 1 to 4, preferably 1 to 3, more preferably 1 to 2, and is, for example, 1. Specific examples of the ethoxylated aromatic ring-containing monomer include ethoxylated o-phenylphenol (meth) acrylate, ethoxylated nonylphenol (meth) acrylate, ethoxylated cresol (meth) acrylate, phenoxyethyl (meth) acrylate, and phenoxydiethylene glycol. Di (meth) acrylate and the like can be mentioned.

　モノマー（ｍ１）における芳香環複数含有モノマーの含有量は、特に制限されず、例えば５重量％以上であってよく、２５重量％以上でもよく、４０重量％以上でもよい。いくつかの態様において、より高い屈折率を有する粘着剤を実現しやすくする観点から、モノマー（ｍ１）における芳香環複数含有モノマーの含有量は、例えば５０重量％以上であってよく、７０重量％以上であることが好ましく、８５重量％以上でもよく、９０重量％以上でもよく、９５重量％以上でもよい。モノマー（ｍ１）の実質的に１００重量％が芳香環複数含有モノマーであってもよい。すなわち、モノマー（ｍ１）として１種または２種以上の芳香環複数含有モノマーのみを使用してもよい。また、いくつかの態様において、例えば高屈折率と粘着特性および／または光学特性とのバランスを考慮して、モノマー（ｍ１）における芳香環複数含有モノマーの含有量は、１００重量％未満であってもよく、９８重量％以下でもよく、９０重量％以下でもよく、８０重量％以下でもよく、６５重量％以下でもよい。いくつかの態様において、粘着特性および／または光学特性を考慮して、モノマー（ｍ１）における芳香環複数含有モノマーの含有量は、７０重量％以下でもよく、５０重量％以下でもよく、２５重量％以下でもよく、１０重量％以下でもよい。ここに開示される技術は、モノマー（ｍ１）における芳香環複数含有モノマーの含有量が５重量％未満である態様でも実施し得る。芳香環複数含有モノマーを使用しなくてもよい。 The content of the monomer containing a plurality of aromatic rings in the monomer (m1) is not particularly limited, and may be, for example, 5% by weight or more, 25% by weight or more, or 40% by weight or more. In some embodiments, the content of the aromatic ring plurality-containing monomer in the monomer (m1) may be, for example, 50% by weight or more, 70% by weight, from the viewpoint of facilitating the realization of a pressure-sensitive adhesive having a higher refractive index. The above is preferable, and it may be 85% by weight or more, 90% by weight or more, or 95% by weight or more. Substantially 100% by weight of the monomer (m1) may be a monomer containing a plurality of aromatic rings. That is, only one type or two or more types of aromatic ring-containing plurality-containing monomers may be used as the monomer (m1). Further, in some embodiments, the content of the aromatic ring plurality-containing monomer in the monomer (m1) is less than 100% by weight, for example, in consideration of the balance between the high refractive index and the adhesive property and / or the optical property. It may be 98% by weight or less, 90% by weight or less, 80% by weight or less, or 65% by weight or less. In some embodiments, the content of the aromatic ring multiple-containing monomer in the monomer (m1) may be 70% by weight or less, 50% by weight or less, or 25% by weight in consideration of adhesive properties and / or optical properties. It may be less than or equal to 10% by weight or less. The technique disclosed herein can also be carried out in an embodiment in which the content of the monomer containing a plurality of aromatic rings in the monomer (m1) is less than 5% by weight. It is not necessary to use a monomer containing a plurality of aromatic rings.

　アクリル系ポリマーを構成するモノマー成分における芳香環複数含有モノマーの含有量は、特に制限されず、所望の屈折率と粘着特性（例えば剥離強度、柔軟性等）および／または光学特性（例えば全光線透過性、ヘイズ値等）とを両立する粘着剤層を実現し得るように設定することができる。上記モノマー成分における芳香環複数含有モノマーの含有量は、例えば３重量％以上であってよく、１０重量％以上でもよく、２５重量％以上でもよい。いくつかの態様において、より高い屈折率を有する粘着剤を実現しやすくする観点から、上記モノマー成分における芳香環複数含有モノマーの含有量は、例えば３５重量％超であってよく、５０重量％超であることが好ましく、７０重量％超でもよく、７５重量％以上でもよく、８５重量％以上でもよく、９０重量％以上でもよく、９５重量％以上でもよい。上記モノマー成分における芳香環複数含有モノマーの含有量は、１００重量％であり得るが、高屈折率と粘着特性および／または光学特性とをバランスよく両立する観点から、１００重量％未満とすることが有利であり、凡そ９９重量％以下とすることが好ましく、９８重量％以下とすることがより好ましく、９６重量％以下でもよく、９３重量％以下でもよく、９０重量％以下でもよく、８５重量％以下でもよく、８０重量％以下でもよく、７５重量％以下でもよい。いくつかの態様において、粘着特性および／または光学特性を考慮して、上記モノマー成分における芳香環複数含有モノマーの含有量は、７０重量％以下でもよく、５０重量％以下でもよく、２５重量％以下でもよく、１５重量％以下でもよく、５重量％以下でもよい。ここに開示される技術は、上記モノマー成分における芳香環複数含有モノマーの含有量が３重量％未満である態様でも実施し得る。 The content of the aromatic ring-containing monomer in the monomer component constituting the acrylic polymer is not particularly limited, and the desired refractive index and adhesive properties (for example, peel strength, flexibility, etc.) and / or optical properties (for example, total light transmission) are not particularly limited. It can be set so as to realize a pressure-sensitive adhesive layer that is compatible with (property, haze value, etc.). The content of the monomer containing a plurality of aromatic rings in the above-mentioned monomer component may be, for example, 3% by weight or more, 10% by weight or more, or 25% by weight or more. In some embodiments, the content of the aromatic ring plurality-containing monomer in the above-mentioned monomer component may be, for example, more than 35% by weight, more than 50% by weight, from the viewpoint of facilitating the realization of a pressure-sensitive adhesive having a higher refractive index. It may be more than 70% by weight, 75% by weight or more, 85% by weight or more, 90% by weight or more, or 95% by weight or more. The content of the monomer containing a plurality of aromatic rings in the above-mentioned monomer component may be 100% by weight, but may be less than 100% by weight from the viewpoint of achieving both high refractive index and adhesive properties and / or optical properties in a well-balanced manner. It is advantageous, preferably about 99% by weight or less, more preferably 98% by weight or less, 96% by weight or less, 93% by weight or less, 90% by weight or less, 85% by weight. It may be less than or equal to 80% by weight, and may be 75% by weight or less. In some embodiments, the content of the aromatic ring plurality-containing monomer in the above-mentioned monomer component may be 70% by weight or less, 50% by weight or less, and 25% by weight or less in consideration of adhesive properties and / or optical properties. However, it may be 15% by weight or less, or 5% by weight or less. The technique disclosed herein can also be carried out in an embodiment in which the content of the monomer containing a plurality of aromatic rings in the above-mentioned monomer component is less than 3% by weight.

　ここに開示される技術のいくつかの態様において、モノマー（ｍ１）の少なくとも一部として、高屈折率モノマーを好ましく採用し得る。ここで「高屈折率モノマー」とは、その屈折率が、例えば凡そ１．５１０以上、好ましくは凡そ１．５３０以上、より好ましくは凡そ１．５５０以上であるモノマーのことを指す。高屈折率モノマーの屈折率の上限は特に制限されないが、粘着剤組成物の調製容易性や、粘着剤として適した柔軟性との両立容易性の観点から、例えば３．０００以下であり、２．５００以下でもよく、２．０００以下でもよく、１．９００以下でもよく、１．８００以下でもよく、１．７００以下でもよい。高屈折率モノマーは、１種を単独でまたは２種以上を組み合わせて用いることができる。
　なお、モノマーの屈折率は、アッベ屈折率計を用いて、測定波長５８９ｎｍ、測定温度２５℃の条件で測定される。アッベ屈折率計としては、ＡＴＡＧＯ社製の型式「ＤＲ－Ｍ４」またはその相当品を用いることができる。メーカー等から２５℃における屈折率の公称値が提供されている場合は、その公称値を採用することができる。 In some aspects of the techniques disclosed herein, a high refractive index monomer may be preferably employed as at least a portion of the monomer (m1). Here, the "high refractive index monomer" refers to a monomer having a refractive index of, for example, about 1.510 or more, preferably about 1.530 or more, and more preferably about 1.550 or more. The upper limit of the refractive index of the high-refractive index monomer is not particularly limited, but is, for example, 3.000 or less from the viewpoint of ease of preparation of the pressure-sensitive adhesive composition and ease of compatibility with flexibility suitable as a pressure-sensitive adhesive. It may be .500 or less, 2.000 or less, 1.900 or less, 1.800 or less, or 1.700 or less. The high refractive index monomer may be used alone or in combination of two or more.
The refractive index of the monomer is measured using an Abbe refractive index meter under the conditions of a measurement wavelength of 589 nm and a measurement temperature of 25 ° C. As the Abbe refractive index meter, a model "DR-M4" manufactured by ATAGO or an equivalent product thereof can be used. If the manufacturer or the like provides a nominal value of the refractive index at 25 ° C., the nominal value can be adopted.

　上記高屈折率モノマーとしては、ここに開示される芳香環含有モノマー（ｍ１）の概念に包含される化合物（例えば、上記で例示した化合物および化合物群）のなかから、該当する屈折率を有するものを適宜採用することができる。具体例としては、ｍ－フェノキシベンジルアクリレート（屈折率：１．５６６、ホモポリマーのＴｇ：－３５℃）、１－ナフチルメチルアクリレート（屈折率：１．５９５、ホモポリマーのＴｇ：３１℃）、エトキシ化ｏ－フェニルフェノールアクリレート（オキシエチレン単位の繰返し数：１、屈折率：１．５７８）、ベンジルアクリレート（屈折率（nD20）：１．５１９、ホモポリマーのＴｇ：６℃）、フェノキシエチルアクリレート（屈折率（nD20）：１．５１７、ホモポリマーのＴｇ：２℃）、フェノキシジエチレングリコールアクリレート（屈折率：１．５１０、ホモポリマーのＴｇ：－３５℃）、６－アクリロイルオキシメチルジナフトチオフェン（６ＭＤＮＴＡ、屈折率：１．７５）、６－メタアクリロイルオキシメチルジナフトチオフェン（６ＭＤＮＴＭＡ、屈折率：１．７２６）、５－アクリロイルオキシエチルジナフトチオフェン（５ＥＤＮＴＡ、屈折率：１．７８６）、６－アクリロイルオキシエチルジナフトチオフェン（６ＥＤＮＴＡ、屈折率：１．７２２）、６－ビニルジナフトチオフェン（６ＶＤＮＴ、屈折率：１．８０２）、５－ビニルジナフトチオフェン（略号：５ＶＤＮＴ、屈折率：１．７９３）、等が挙げられるが、これらに限定されない。 The high-refractive index monomer has a refractive index among the compounds included in the concept of the aromatic ring-containing monomer (m1) disclosed herein (for example, the compounds and compound groups exemplified above). Can be adopted as appropriate. Specific examples include m-phenoxybenzyl acrylate (refraction: 1.566, homopolymer Tg: −35 ° C.), 1-naphthylmethyl acrylate (refraction: 1.595, homopolymer Tg: 31 ° C.), O-phenylphenol acrylate ethoxylated (number of repetitions of oxyethylene unit: 1, refraction: 1.578), benzyl acrylate (refraction (nD20): 1.519, homopolymer Tg: 6 ° C), phenoxyethyl acrylate (Refraction (nD20): 1.517, homopolymer Tg: 2 ° C.), phenoxydiethylene glycol acrylate (refraction: 1.510, homopolymer Tg: -35 ° C.), 6-acryloyloxymethyldinaphthophen ( 6MDNTA, Refraction: 1.75), 6-Metaacryloyloxymethyldinaphthophen (6MDNTMA, Refraction: 1.726), 5-Acryloyloxyethyldinaphthophen (5EDNTA, Refraction: 1.786), 6 -Acryloyloxyethyl dinaphthophene (6EDNTA, refraction: 1.722), 6-vinyldinaphthophene (6VDNT, refraction: 1.802), 5-vinyldinaphthophen (abbreviation: 5VDNT, refraction: 1) .793), etc., but are not limited to these.

　モノマー（ｍ１）における高屈折率モノマー（すなわち、屈折率が凡そ１．５１０以上、好ましくは凡そ１．５３０以上、より好ましくは凡そ１．５５０以上である芳香環含有モノマー）の含有量は、特に制限されず、例えば５重量％以上であってよく、２５重量％以上でもよく、３５重量％以上でもよく、４０重量％以上でもよい。いくつかの態様において、より高い屈折率を得やすくする観点から、モノマー（ｍ１）における高屈折率モノマーの含有量は、例えば５０重量％以上であってよく、７０重量％以上であることが好ましく、８５重量％以上でもよく、９０重量％以上でもよく、９５重量％以上でもよい。モノマー（ｍ１）の実質的に１００重量％が高屈折率モノマーであってもよい。また、いくつかの態様において、例えば高屈折率と粘着特性および／または光学特性とをバランスよく両立する観点から、モノマー（ｍ１）における高屈折率モノマーの含有量は、１００重量％未満であってもよく、９８重量％以下でもよく、９０重量％以下でもよく、８０重量％以下でもよく、６５重量％以下でもよい。いくつかの態様において、粘着特性および／または光学特性を考慮して、モノマー（ｍ１）における高屈折率モノマーの含有量は、７０重量％以下でもよく、５０重量％以下でもよく、２５重量％以下でもよく、１５重量％以下でもよく、１０重量％以下でもよい。ここに開示される技術は、モノマー成分（ｍ１）における高屈折率モノマーの含有量が５重量％未満である態様でも実施し得る。高屈折率モノマーを使用しなくてもよい。 The content of the high refractive index monomer (that is, the aromatic ring-containing monomer having a refractive index of about 1.510 or more, preferably about 1.530 or more, more preferably about 1.550 or more) in the monomer (m1) is particularly high. It is not limited, and may be, for example, 5% by weight or more, 25% by weight or more, 35% by weight or more, or 40% by weight or more. In some embodiments, the content of the high refractive index monomer in the monomer (m1) may be, for example, 50% by weight or more, preferably 70% by weight or more, from the viewpoint of facilitating the acquisition of a higher refractive index. , 85% by weight or more, 90% by weight or more, 95% by weight or more. Substantially 100% by weight of the monomer (m1) may be a high refractive index monomer. Further, in some embodiments, the content of the high refractive index monomer in the monomer (m1) is less than 100% by weight, for example, from the viewpoint of achieving both high refractive index and adhesive properties and / or optical properties in a well-balanced manner. It may be 98% by weight or less, 90% by weight or less, 80% by weight or less, or 65% by weight or less. In some embodiments, the content of the high refractive index monomer in the monomer (m1) may be 70% by weight or less, 50% by weight or less, and 25% by weight or less in consideration of adhesive properties and / or optical properties. However, it may be 15% by weight or less, or 10% by weight or less. The technique disclosed herein can also be carried out in an embodiment in which the content of the high refractive index monomer in the monomer component (m1) is less than 5% by weight. It is not necessary to use a high refractive index monomer.

　アクリル系ポリマーを構成するモノマー成分における高屈折率モノマーの含有量は、特に制限されず、所望の屈折率と粘着特性（例えば剥離強度、柔軟性等）および／または光学特性（例えば全光線透過性、ヘイズ値等）とを両立する粘着剤層を実現し得るように設定することができる。上記モノマー成分における高屈折率モノマーの含有量は、例えば３重量％以上であってよく、１０重量％以上でもよく、２５重量％以上でもよい。いくつかの態様において、より高い屈折率を有する粘着剤を実現しやすくする観点から、上記モノマー成分における高屈折率モノマーの含有量は、例えば３５重量％超であってよく、５０重量％超であることが好ましく、７０重量％超でもよく、７５重量％以上でもよく、８５重量％以上でもよく、９０重量％以上でもよく、９５重量％以上でもよい。上記モノマー成分における高屈折率モノマーの含有量は、１００重量％であり得るが、高屈折率と粘着特性および／または光学特性とをバランスよく両立する観点から、１００重量％未満とすることが有利であり、９９重量％以下とすることが好ましく、９８重量％以下とすることがより好ましく、９６重量％以下でもよく、９３重量％以下でもよく、９０重量％以下でもよく、８５重量％以下でもよく、８０重量％以下でもよく、７５重量％以下でもよい。いくつかの態様において、粘着特性および／または光学特性を考慮して、上記モノマー成分における高屈折率モノマーの含有量は、７０重量％以下でもよく、５０重量％以下でもよく、２５重量％以下でもよく、１５重量％以下でもよく、５重量％以下でもよい。ここに開示される技術は、上記モノマー成分における高屈折率モノマーの含有量が３重量％未満である態様でも実施し得る。 The content of the high refractive index monomer in the monomer component constituting the acrylic polymer is not particularly limited, and the desired refractive index and adhesive properties (for example, peel strength, flexibility, etc.) and / or optical properties (for example, total light transmittance) are not particularly limited. , Haze value, etc.) can be set so as to realize a pressure-sensitive adhesive layer. The content of the high refractive index monomer in the monomer component may be, for example, 3% by weight or more, 10% by weight or more, or 25% by weight or more. In some embodiments, from the viewpoint of facilitating the realization of a pressure-sensitive adhesive having a higher refractive index, the content of the high refractive index monomer in the above-mentioned monomer component may be, for example, more than 35% by weight, and more than 50% by weight. It may be more than 70% by weight, 75% by weight or more, 85% by weight or more, 90% by weight or more, or 95% by weight or more. The content of the high refractive index monomer in the above-mentioned monomer component can be 100% by weight, but it is advantageous to make it less than 100% by weight from the viewpoint of achieving a good balance between the high refractive index and the adhesive property and / or the optical property. It is preferably 99% by weight or less, more preferably 98% by weight or less, 96% by weight or less, 93% by weight or less, 90% by weight or less, and 85% by weight or less. It may be 80% by weight or less, or 75% by weight or less. In some embodiments, the content of the high refractive index monomer in the monomer component may be 70% by weight or less, 50% by weight or less, or 25% by weight or less in consideration of adhesive properties and / or optical properties. It may be 15% by weight or less, or 5% by weight or less. The technique disclosed herein can also be carried out in an embodiment in which the content of the high refractive index monomer in the monomer component is less than 3% by weight.

　ここに開示される技術のいくつかの好ましい態様では、モノマー（ｍ１）の少なくとも一部として、ホモポリマーのＴｇが１０℃以下（好ましくは５℃以下または０℃以下、より好ましくは－１０℃以下、さらに好ましくは－２０℃以下、例えば－２５℃以下）である芳香環含有モノマー（以下、「モノマーＬ」と表記することがある。）を採用する。モノマー成分における芳香環含有モノマー（ｍ１）（特に、上述した芳香環複数含有モノマーおよび高屈折率モノマーの一方または両方に該当する芳香環含有モノマー（ｍ１））の含有量を多くすると、粘着剤の貯蔵弾性率Ｇ’は概して上昇する傾向にあるところ、該モノマー（ｍ１）の一部または全部としてモノマーＬを採用することにより、貯蔵弾性率Ｇ’の上昇を抑制することができる。これにより、粘着剤として適した柔軟性をよりよく維持しつつ、屈折率を向上させることができる。モノマーＬのＴｇの下限は特に制限されない。屈折率向上効果とのバランスを考慮して、いくつかの態様において、モノマーＬのＴｇは、例えば－７０℃以上であってよく、－５５℃以上でもよく、－４５℃以上でもよい。モノマーＬは、１種を単独でまたは２種以上を組み合わせて用いることができる。 In some preferred embodiments of the techniques disclosed herein, the Tg of the homopolymer as at least a portion of the monomer (m1) is 10 ° C. or lower (preferably 5 ° C. or lower or 0 ° C. or lower, more preferably −10 ° C. or lower). , More preferably −20 ° C. or lower, for example −25 ° C. or lower), an aromatic ring-containing monomer (hereinafter, may be referred to as “monomer L”) is adopted. Increasing the content of the aromatic ring-containing monomer (m1) in the monomer component (particularly, the aromatic ring-containing monomer (m1) corresponding to one or both of the above-mentioned aromatic ring plural-containing monomer and high refractive index monomer) increases the content of the pressure-sensitive adhesive. Where the storage elasticity G'geners generally tends to increase, the increase in the storage elasticity G'can be suppressed by adopting the monomer L as a part or all of the monomer (m1). This makes it possible to improve the refractive index while better maintaining the flexibility suitable as a pressure-sensitive adhesive. The lower limit of Tg of the monomer L is not particularly limited. In consideration of the balance with the effect of improving the refractive index, in some embodiments, the Tg of the monomer L may be, for example, −70 ° C. or higher, −55 ° C. or higher, or −45 ° C. or higher. As the monomer L, one type can be used alone or two or more types can be used in combination.

　モノマーＬとしては、ここに開示される芳香環含有モノマー（ｍ１）の概念に包含される化合物（例えば、上記で例示した化合物および化合物群）のなかから、該当するＴｇを有するものを適宜採用することができる。モノマーＬとして使用し得る芳香環含有モノマーの一好適例として、ｍ－フェノキシベンジルアクリレート（ホモポリマーのＴｇ：－３５℃）が挙げられる。他の一好適例として、フェノキシジエチレングリコールアクリレート（ホモポリマーのＴｇ：－３５℃）が挙げられる。 As the monomer L, among the compounds included in the concept of the aromatic ring-containing monomer (m1) disclosed herein (for example, the compounds and compound groups exemplified above), those having the corresponding Tg are appropriately adopted. be able to. As a preferable example of the aromatic ring-containing monomer that can be used as the monomer L, m-phenoxybenzyl acrylate (Tg of homopolymer: −35 ° C.) can be mentioned. Another preferred example is phenoxydiethylene glycol acrylate (homopolymer Tg: −35 ° C.).

　モノマー（ｍ１）におけるモノマーＬの含有量は、特に制限されず、例えば５重量％以上であってよく、２５重量％以上でもよく、４０重量％以上でもよい。いくつかの態様において、高屈折率と柔軟性とをより高レベルで両立する粘着剤を得やすくする観点から、モノマー（ｍ１）におけるモノマーＬの含有量は、例えば５０重量％以上であってよく、６０重量％以上でもよく、７０重量％以上でもよく、７５重量％以上でもよく、８５重量％以上でもよく、９０重量％以上でもよく、９５重量％以上でもよい。モノマー（Ａ１）の実質的に１００重量％がモノマーＬであってもよい。また、いくつかの態様において、例えば粘着剤として適した柔軟性と高屈折率とをバランスよく両立する観点から、モノマー（ｍ１）におけるモノマーＬの含有量は、１００重量％未満であってもよく、９８重量％以下でもよく、９０重量％以下でもよく、８０重量％以下でもよく、７０重量％以下でもよく、５０重量％以下でもよく、２５重量％以下でもよく、１０重量％以下でもよい。ここに開示される技術は、モノマー（ｍ１）におけるモノマーＬの含有量が５重量％未満である態様でも実施し得る。モノマーＬを使用しなくてもよい。 The content of the monomer L in the monomer (m1) is not particularly limited, and may be, for example, 5% by weight or more, 25% by weight or more, or 40% by weight or more. In some embodiments, the content of the monomer L in the monomer (m1) may be, for example, 50% by weight or more, from the viewpoint of facilitating the acquisition of a pressure-sensitive adhesive having both high refractive index and flexibility at a higher level. , 60% by weight or more, 70% by weight or more, 75% by weight or more, 85% by weight or more, 90% by weight or more, 95% by weight or more. Substantially 100% by weight of the monomer (A1) may be the monomer L. Further, in some embodiments, the content of the monomer L in the monomer (m1) may be less than 100% by weight from the viewpoint of achieving both flexibility suitable as a pressure-sensitive adhesive and high refractive index in a well-balanced manner. , 98% by weight or less, 90% by weight or less, 80% by weight or less, 70% by weight or less, 50% by weight or less, 25% by weight or less, or 10% by weight or less. The technique disclosed herein can also be carried out in an embodiment in which the content of the monomer L in the monomer (m1) is less than 5% by weight. It is not necessary to use the monomer L.

　アクリル系ポリマーを構成するモノマー成分におけるモノマーＬの含有量は、例えば３重量％以上であってよく、１０重量％以上でもよく、２５重量％以上でもよい。いくつかの態様において、高屈折率と柔軟性とをより高レベルで両立する粘着剤を得やすくする観点から、モノマー成分におけるモノマーＬの含有量は、例えば３５重量％超であってよく、５０重量％超であることが好ましく、７０重量％超でもよく、７５重量％以上でもよく、８５重量％以上でもよく、９０重量％以上でもよく、９５重量％以上でもよい。上記モノマー成分におけるモノマーＬの含有量は、１００重量％であり得るが、高屈折率と粘着特性および／または光学特性とのバランスを考慮して、１００重量％未満とすることが有利であり、凡そ９９重量％以下であることが好ましく、９８重量％以下であることがより好ましく、９６重量％以下でもよく、９５重量％以下でもよく、９３重量％以下でもよく、９０重量％以下でもよく、８５重量％以下でもよく、８０重量％以下でもよく、７５重量％以下でもよい。いくつかの態様において、上記モノマー成分におけるモノマーＬの含有量は、７０重量％以下でもよく、５０重量％以下でもよく、２５重量％以下でもよく、１５重量％以下でもよく、５重量％以下でもよい。ここに開示される技術は、上記モノマー成分におけるモノマーＬの含有量が３重量％未満である態様でも実施し得る。 The content of the monomer L in the monomer component constituting the acrylic polymer may be, for example, 3% by weight or more, 10% by weight or more, or 25% by weight or more. In some embodiments, the content of the monomer L in the monomer component may be, for example,> 35% by weight, 50 It is preferably more than 70% by weight, more than 70% by weight, more than 75% by weight, more than 85% by weight, more than 90% by weight, and more than 95% by weight. The content of the monomer L in the above-mentioned monomer component can be 100% by weight, but it is advantageous that the content is less than 100% by weight in consideration of the balance between the high refractive index and the adhesive property and / or the optical property. It is preferably about 99% by weight or less, more preferably 98% by weight or less, 96% by weight or less, 95% by weight or less, 93% by weight or less, 90% by weight or less. It may be 85% by weight or less, 80% by weight or less, or 75% by weight or less. In some embodiments, the content of the monomer L in the monomer component may be 70% by weight or less, 50% by weight or less, 25% by weight or less, 15% by weight or less, or 5% by weight or less. good. The technique disclosed herein can also be carried out in an embodiment in which the content of the monomer L in the monomer component is less than 3% by weight.

　いくつかの態様において、モノマー（ｍ１）の組成に基づくガラス転移温度Ｔｇｍ１は、粘着剤の柔軟性の観点から、凡そ２０℃以下であることが有利であり、好ましくは１０℃以下（例えば５℃以下）、より好ましくは０℃以下であり、さらに好ましくは－１０℃以下であり、－２０℃以下でもよく、－２５℃以下でもよい。ガラス転移温度Ｔｇｍ１の下限は特に制限されない。屈折率向上効果とのバランスを考慮して、いくつかの態様において、ガラス転移温度Ｔｇｍ１は、例えば－７０℃以上であってよく、－５５℃以上でもよく、－４５℃以上でもよい。ここに開示される技術は、ガラス転移温度Ｔｇｍ１が例えば－４０℃以上、－３５℃以上、－３３℃以上、－３０℃以上、または－２５℃以上である態様でも好適に実施され得る。 In some embodiments, the glass transition temperature Tg m1 based on the composition of the monomer (m1) is preferably about 20 ° C. or lower, preferably 10 ° C. or lower (eg 5) from the viewpoint of adhesive flexibility. (° C. or lower), more preferably 0 ° C. or lower, still more preferably −10 ° C. or lower, −20 ° C. or lower, or −25 ° C. or lower. The lower limit of the glass transition temperature Tg m1 is not particularly limited. In consideration of the balance with the effect of improving the refractive index, the glass transition temperature Tg m1 may be, for example, −70 ° C. or higher, −55 ° C. or higher, or −45 ° C. or higher in some embodiments. The technique disclosed herein can also be preferably carried out in an embodiment in which the glass transition temperature Tg m1 is, for example, −40 ° C. or higher, −35 ° C. or higher, −33 ° C. or higher, −30 ° C. or higher, or −25 ° C. or higher.

　ここで、モノマー（ｍ１）の組成に基づくガラス転移温度Ｔｇｍ１とは、アクリル系ポリマーを構成するモノマー成分のうちモノマー（ｍ１）のみの組成に基づいて、後述するＦｏｘの式により求められるＴｇをいう。ガラス転移温度Ｔｇｍ１は、アクリル系ポリマーを構成するモノマー成分のうちモノマー（ｍ１）のみを対象として後述するＦｏｘの式を適用し、モノマー（ｍ１）として用いられる各芳香環含有モノマーのホモポリマーのガラス転移温度と、モノマー（ｍ１）の合計量に占める各芳香環含有モノマーの重量分率とから算出することができる。モノマー（ｍ１）として１種類のモノマーのみを使用する態様では、該モノマーのホモポリマーのＴｇとガラス転移温度Ｔｇｍ１とは一致する。 Here, the glass transition temperature Tg m1 based on the composition of the monomer (m1) is a Tg obtained by the Fox formula described later based on the composition of only the monomer (m1) among the monomer components constituting the acrylic polymer. say. The glass transition temperature Tg m1 is a homopolymer of each aromatic ring-containing monomer used as the monomer (m1) by applying the Fox formula described later for only the monomer (m1) among the monomer components constituting the acrylic polymer. It can be calculated from the glass transition temperature and the weight fraction of each aromatic ring-containing monomer in the total amount of the monomers (m1). In the embodiment in which only one kind of monomer is used as the monomer (m1), the Tg of the homopolymer of the monomer and the glass transition temperature Tg m1 are the same.

　いくつかの態様において、芳香環含有モノマー（ｍ１）としては、モノマーＬ（すなわち、ホモポリマーのＴｇが１０℃以下、好ましくは５℃以下または０℃以下、より好ましくは－１０℃以下、さらに好ましくは－２０℃以下、例えば－２５℃以下である芳香環含有モノマー）と、Ｔｇが１０℃よりも高いモノマーＨとを組み合わせて用いることができる。モノマーＨのＴｇは、例えば１０℃超であってよく、１５℃超であってもよく、２０℃超であってもよい。モノマーＬとモノマーＨとを組み合わせて用いることにより、例えばモノマー成分における芳香環含有モノマー（ｍ１）の含有量が比較的多い構成において、粘着剤の高屈折率と柔軟性とをより高レベルで両立させることができる。モノマーＬとモノマーＨとの使用量比は、かかる効果が好適に発現するように設定することができ、特に限定されない。例えば、上述したいずれかのガラス転移温度Ｔｇｍ１を満たすようにモノマーＬとモノマーＨとの使用量比を設定することが好ましい。 In some embodiments, the aromatic ring-containing monomer (m1) includes monomer L (ie, homopolymer Tg of 10 ° C. or lower, preferably 5 ° C. or lower or 0 ° C. or lower, more preferably −10 ° C. or lower, even more preferably. (Aromatic ring-containing monomer having a temperature of −20 ° C. or lower, for example, −25 ° C. or lower) and a monomer H having a Tg higher than 10 ° C. can be used in combination. The Tg of the monomer H may be, for example, more than 10 ° C., more than 15 ° C., or more than 20 ° C. By using the monomer L and the monomer H in combination, for example, in a configuration in which the content of the aromatic ring-containing monomer (m1) in the monomer component is relatively large, the high refractive index and flexibility of the pressure-sensitive adhesive are compatible at a higher level. Can be made to. The usage amount ratio of the monomer L and the monomer H can be set so as to preferably exhibit such an effect, and is not particularly limited. For example, it is preferable to set the usage amount ratio of the monomer L and the monomer H so as to satisfy any of the above-mentioned glass transition temperatures Tg m1.

　いくつかの態様において、芳香環含有モノマー（ｍ１）は、２以上の非縮合芳香環が直接化学結合した構造（例えばビフェニル構造）を含まない化合物から好ましく選択され得る。例えば、２以上の非縮合芳香環が直接化学結合した構造を含む化合物の含有量が５重量％未満（より好ましくは３重量％未満であり、０重量％でもよい。）である組成のモノマー成分により構成されたアクリル系ポリマーが好ましい。このように２以上の非縮合芳香環が直接化学結合した構造を含む化合物の使用量を制限することは、柔軟性や粘着性と高屈折率とをバランスよく両立させた粘着剤を実現する観点から有利となり得る。 In some embodiments, the aromatic ring-containing monomer (m1) can be preferably selected from compounds that do not contain a structure in which two or more uncondensed aromatic rings are directly chemically bonded (eg, a biphenyl structure). For example, a monomer component having a composition in which the content of the compound containing a structure in which two or more non-condensed aromatic rings are directly chemically bonded is less than 5% by weight (more preferably less than 3% by weight and may be 0% by weight). The acrylic polymer composed of is preferable. Limiting the amount of a compound containing a structure in which two or more non-condensed aromatic rings are directly chemically bonded in this way is a viewpoint of realizing a pressure-sensitive adhesive having a good balance of flexibility, tackiness and high refractive index. Can be advantageous from.

　（モノマー（ｍ２））
　ここに開示される技術のいくつかの態様において、アクリル系ポリマーを構成するモノマー成分は、上記モノマー（ｍ１）に加えて、モノマー（ｍ２）をさらに含有し得る。上記モノマー（ｍ２）は、水酸基を有するモノマー（水酸基含有モノマー）およびカルボキシ基を有するモノマー（カルボキシ基含有モノマー）の少なくとも一方に該当するモノマーである。上記水酸基含有モノマーは、１分子内に少なくとも１つの水酸基と少なくとも１つのエチレン性不飽和基とを有する化合物である。上記カルボキシ基含有モノマーは、１分子内に少なくとも１つのカルボキシ基と少なくとも１つのエチレン性不飽和基とを含む化合物である。モノマー（ｍ２）は、アクリル系ポリマーに架橋点を導入したり、粘着剤に適度な凝集性を付与したりするために役立ち得る。モノマー（ｍ２）は、１種を単独でまたは２種以上を組み合わせて用いることができる。モノマー（ｍ２）は、典型的には芳香環を含有しないモノマーである。 (Monomer (m2))
In some aspects of the techniques disclosed herein, the monomer component constituting the acrylic polymer may further contain a monomer (m2) in addition to the above-mentioned monomer (m1). The monomer (m2) is a monomer corresponding to at least one of a monomer having a hydroxyl group (hydroxyl group-containing monomer) and a monomer having a carboxy group (carboxy group-containing monomer). The hydroxyl group-containing monomer is a compound having at least one hydroxyl group and at least one ethylenically unsaturated group in one molecule. The carboxy group-containing monomer is a compound containing at least one carboxy group and at least one ethylenically unsaturated group in one molecule. The monomer (m2) can be useful for introducing cross-linking points into the acrylic polymer and imparting appropriate cohesiveness to the pressure-sensitive adhesive. The monomer (m2) may be used alone or in combination of two or more. The monomer (m2) is typically a monomer that does not contain an aromatic ring.

　モノマー（ｍ２）の有するエチレン性不飽和基の例としては、（メタ）アクリロイル基、ビニル基、（メタ）アリル基等が挙げられる。重合反応性の観点から（メタ）アクリロイル基が好ましく、柔軟性や粘着性の観点からアクリロイル基がより好ましい。粘着剤の柔軟性低下を抑制する観点から、モノマー（ｍ２）としては、１分子中に含まれるエチレン性不飽和基の数が１である化合物（すなわち、単官能モノマー）が好ましく用いられる。 Examples of the ethylenically unsaturated group contained in the monomer (m2) include a (meth) acryloyl group, a vinyl group, a (meth) allyl group and the like. A (meth) acryloyl group is preferable from the viewpoint of polymerization reactivity, and an acryloyl group is more preferable from the viewpoint of flexibility and adhesiveness. From the viewpoint of suppressing a decrease in the flexibility of the pressure-sensitive adhesive, a compound (that is, a monofunctional monomer) in which the number of ethylenically unsaturated groups contained in one molecule is 1 is preferably used as the monomer (m2).

　水酸基含有モノマーの例としては、（メタ）アクリル酸２－ヒドロキシエチル、（メタ）アクリル酸２－ヒドロキシプロピル、（メタ）アクリル酸４－ヒドロキシブチル、（メタ）アクリル酸６－ヒドロキシヘキシル、（メタ）アクリル酸８－ヒドロキシオクチル、（メタ）アクリル酸１０－ヒドロキシデシル、（メタ）アクリル酸１２－ヒドロキシラウリル、（４－ヒドロキシメチルシクロへキシル）メチル（メタ）アクリレート等の（メタ）アクリル酸ヒドロキシアルキルが挙げられるが、これらに限定されない。好ましく使用し得る水酸基含有モノマーの例として、アクリル酸４－ヒドロキシブチル（Ｔｇ：－４０℃）およびアクリル酸２－ヒドロキシエチル（Ｔｇ：－１５℃）が挙げられる。室温域における柔軟性向上の観点から、よりＴｇの低いアクリル酸４－ヒドロキシブチルがより好ましい。好ましい一態様では、モノマー（ｍ２）の５０重量％以上（例えば５０重量％超、７０重量％超または８５重量％超）がアクリル酸４－ヒドロキシブチルであり得る。水酸基含有モノマーは、１種を単独でまたは２種以上を組み合わせて用いることができる。 Examples of hydroxyl group-containing monomers include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 6-hydroxyhexyl (meth) acrylate, and (meth). ) Hydroxy (meth) acrylate such as 8-hydroxyoctyl acrylate, 10-hydroxydecyl (meth) acrylate, 12-hydroxylauryl (meth) acrylate, (4-hydroxymethylcyclohexyl) methyl (meth) acrylate Alkyl includes, but is not limited to. Examples of hydroxyl group-containing monomers that can be preferably used include 4-hydroxybutyl acrylate (Tg: −40 ° C.) and 2-hydroxyethyl acrylate (Tg: −15 ° C.). From the viewpoint of improving flexibility in the room temperature range, 4-hydroxybutyl acrylate having a lower Tg is more preferable. In a preferred embodiment, more than 50% by weight (eg, more than 50% by weight, more than 70% by weight or more than 85% by weight) of the monomer (m2) can be 4-hydroxybutyl acrylate. The hydroxyl group-containing monomer may be used alone or in combination of two or more.

　モノマー（ｍ２）として水酸基含有モノマーを使用するいくつかの態様において、上記水酸基含有モノマーは、メタクリロイル基を有しない化合物から選択される１種または２種以上であり得る。メタクリロイル基を有しない水酸基含有モノマーの好適例として、上述した各種のアクリル酸ヒドロキシアルキルが挙げられる。例えば、モノマー（ｍ２）として使用する水酸基含有モノマーのうち５０重量％超、７０重量％超または８５重量％超がアクリル酸ヒドロキシアルキルであることが好ましい。アクリル酸ヒドロキシアルキルの使用により、架橋点の提供や適度な凝集性の付与に役立つヒドロキシ基をアクリル系ポリマーに導入することができ、かつ対応するメタクリル酸ヒドロキシアルキルのみを使用する場合に比べて室温域における柔軟性や粘着性の良い粘着剤が得られやすい。 In some embodiments where a hydroxyl group-containing monomer is used as the monomer (m2), the hydroxyl group-containing monomer may be one or more selected from compounds having no methacryloyl group. Preferable examples of the hydroxyl group-containing monomer having no methacryloyl group include the above-mentioned various hydroxyalkyl acrylates. For example, it is preferable that more than 50% by weight, more than 70% by weight, or more than 85% by weight of the hydroxyl group-containing monomers used as the monomer (m2) is hydroxyalkyl acrylate. By using hydroxyalkyl acrylate, hydroxy groups that help provide cross-linking points and impart appropriate cohesiveness can be introduced into the acrylic polymer, and the room temperature is higher than when only the corresponding hydroxyalkyl methacrylate is used. It is easy to obtain an adhesive with good flexibility and adhesiveness in the region.

　カルボキシ基含有モノマーの例としては、（メタ）アクリル酸、（メタ）アクリル酸カルボキシエチル、（メタ）アクリル酸カルボキシペンチル等のアクリル系モノマーのほか、イタコン酸、マレイン酸、フマル酸、クロトン酸、イソクロトン酸等が挙げられるが、これらに限定されない。好ましく使用し得るカルボキシ基含有モノマーの例として、アクリル酸、メタクリル酸が挙げられる。カルボキシ基含有モノマーは、１種を単独でまたは２種以上を組み合わせて用いることができる。水酸基含有モノマーとカルボキシ基含有モノマーとを併用してもよい。 Examples of carboxy group-containing monomers include acrylic monomers such as (meth) acrylic acid, carboxyethyl (meth) acrylate, and carboxypentyl (meth) acrylate, as well as itaconic acid, maleic acid, fumaric acid, and crotonic acid. Examples thereof include, but are not limited to, isocrotonic acid. Examples of carboxy group-containing monomers that can be preferably used include acrylic acid and methacrylic acid. The carboxy group-containing monomer may be used alone or in combination of two or more. A hydroxyl group-containing monomer and a carboxy group-containing monomer may be used in combination.

　アクリル系ポリマーを構成するモノマー成分におけるモノマー（ｍ２）の含有量は、特に制限されず、目的に応じて設定し得る。いくつかの態様において、上記モノマー（ｍ２）の含有量は、例えば０．０１重量％以上、０．１重量％以上または０．５重量％以上であり得る。より高い使用効果を得る観点から、いくつかの態様において、上記モノマー（Ａ２）の含有量は、１重量％以上とすることが好ましく、２重量％以上としてもよく、４重量％以上としてもよい。モノマー成分におけるモノマー（ｍ２）の含有量の上限は、他のモノマーの含有量との合計が１００重量％を超えないように設定される。いくつかの態様において、上記モノマー（ｍ２）の含有量は、例えば３０重量％以下または２５重量％以下とすることが適当であり、モノマー（ｍ１）の含有量を相対的に多くして高屈折率化を容易とする観点から、２０重量％以下とすることが好ましく、１５重量％以下とすることがより好ましく、１２重量％未満でもよく、１０重量％未満でもよく、７重量％未満でもよい。 The content of the monomer (m2) in the monomer component constituting the acrylic polymer is not particularly limited and can be set according to the purpose. In some embodiments, the content of the monomer (m2) can be, for example, 0.01% by weight or more, 0.1% by weight or more, or 0.5% by weight or more. From the viewpoint of obtaining a higher effect of use, in some embodiments, the content of the monomer (A2) is preferably 1% by weight or more, preferably 2% by weight or more, or 4% by weight or more. .. The upper limit of the content of the monomer (m2) in the monomer component is set so that the total content with the content of other monomers does not exceed 100% by weight. In some embodiments, it is appropriate that the content of the monomer (m2) is, for example, 30% by weight or less or 25% by weight or less, and the content of the monomer (m1) is relatively increased to achieve high refraction. From the viewpoint of facilitating rate, it is preferably 20% by weight or less, more preferably 15% by weight or less, less than 12% by weight, less than 10% by weight, or less than 7% by weight. ..

　モノマー（ｍ２）として水酸基含有モノマーを用いる態様において、モノマー成分における水酸基含有モノマーの含有量は、特に制限されず、例えば０．０１重量％以上（好ましくは０．１重量％以上、より好ましくは０．５重量％以上）であり得る。いくつかの態様において、上記水酸基含有モノマーの含有量は、上記モノマー成分の１重量％以上とすることが好ましく、２重量％以上としてもよく、４重量％以上としてもよい。モノマー成分における水酸基含有モノマーの含有量の上限は、他のモノマーの含有量との合計が１００重量％を超えないように設定され、例えば３０重量％以下または２５重量％以下とすることが適当であり、モノマー（ｍ１）の含有量を相対的に多くして高屈折率化を容易とする観点から２０重量％以下とすることが好ましく、１５重量％以下とすることがより好ましく、１２重量％未満でもよく、１０重量％未満でもよく、７重量％未満でもよい。 In the embodiment in which the hydroxyl group-containing monomer is used as the monomer (m2), the content of the hydroxyl group-containing monomer in the monomer component is not particularly limited, and is, for example, 0.01% by weight or more (preferably 0.1% by weight or more, more preferably 0). It can be 5.5% by weight or more). In some embodiments, the content of the hydroxyl group-containing monomer is preferably 1% by weight or more, preferably 2% by weight or more, or 4% by weight or more of the monomer component. The upper limit of the content of the hydroxyl group-containing monomer in the monomer component is set so that the total content with the content of other monomers does not exceed 100% by weight, and it is appropriate to set it to, for example, 30% by weight or less or 25% by weight or less. From the viewpoint of facilitating high refractive index by relatively increasing the content of the monomer (m1), it is preferably 20% by weight or less, more preferably 15% by weight or less, and 12% by weight. It may be less than 10% by weight, less than 7% by weight, or less than 7% by weight.

　モノマー（ｍ２）としてカルボキシ基含有モノマーを用いる態様において、モノマー成分におけるカルボキシ基含有モノマーの含有量は、特に制限されず、例えば０．０１重量％以上（好ましくは０．１重量％以上、より好ましくは０．３重量％以上）であり得る。いくつかの態様において、上記カルボキシ基含有モノマーの含有量は、１重量％以上としてもよく、２重量％以上としてもよく、４重量％以上としてもよい。モノマー成分におけるカルボキシ基含有モノマーの含有量の上限は、他のモノマーの使用量との合計が１００重量％を超えないように設定され、例えば３０重量％以下または２５重量％以下とすることが適当であり、モノマー（ｍ１）の含有量を相対的に多くして高屈折率化を容易とする観点から、２０重量％以下とすることが好ましく、１５重量％以下とすることがより好ましく、１２重量％未満でもよく、１０重量％未満でもよい。いくつかの態様において、粘着剤の柔軟性向上の観点から、上記カルボキシ基含有モノマーの含有量は、７重量％未満とすることが有利であり、５重量％未満とすることが好ましく、３重量％未満としてもよく、１重量％未満としてもよく、０．５重量％未満としてもよい。ここに開示される技術は、例えば、モノマー（ｍ２）として水酸基含有モノマーのみを用いる態様、すなわちカルボキシ基含有モノマーを使用しない態様で好ましく実施され得る。 In the embodiment in which the carboxy group-containing monomer is used as the monomer (m2), the content of the carboxy group-containing monomer in the monomer component is not particularly limited, and is, for example, 0.01% by weight or more (preferably 0.1% by weight or more, more preferably 0.1% by weight or more). Can be 0.3% by weight or more). In some embodiments, the content of the carboxy group-containing monomer may be 1% by weight or more, 2% by weight or more, or 4% by weight or more. The upper limit of the content of the carboxy group-containing monomer in the monomer component is set so that the total with the amount of other monomers used does not exceed 100% by weight, and it is appropriate to set it to, for example, 30% by weight or less or 25% by weight or less. From the viewpoint of facilitating a high refractive index by relatively increasing the content of the monomer (m1), the content is preferably 20% by weight or less, more preferably 15% by weight or less, and 12 It may be less than 10% by weight, or less than 10% by weight. In some embodiments, from the viewpoint of improving the flexibility of the pressure-sensitive adhesive, the content of the carboxy group-containing monomer is preferably less than 7% by weight, preferably less than 5% by weight, and 3% by weight. It may be less than%, less than 1% by weight, or less than 0.5% by weight. The technique disclosed herein can be preferably carried out, for example, in a mode in which only a hydroxyl group-containing monomer is used as the monomer (m2), that is, a mode in which a carboxy group-containing monomer is not used.

　アクリル系ポリマーを構成するモノマー成分におけるモノマー（ｍ１）とモノマー（ｍ２）との合計含有量は、例えば３１重量％以上であってよく、好ましくは５１重量％以上であり、６１重量％以上でもよく、７１重量％以上でもよい。いくつかの態様において、アクリル系ポリマーを構成するモノマー成分におけるモノマー（ｍ１）とモノマー（ｍ２）との合計含有量は、これらのモノマーの効果を好適に発揮しやすくする観点から、例えば７６重量％以上であってよく、８１重量％以上であることが好ましく、８６重量％以上でもよく、９１重量％以上でもよく、９６重量％以上でもよく、９９重量％以上でもよく、実質的に１００重量％でもよい。 The total content of the monomer (m1) and the monomer (m2) in the monomer component constituting the acrylic polymer may be, for example, 31% by weight or more, preferably 51% by weight or more, or 61% by weight or more. , 71% by weight or more. In some embodiments, the total content of the monomer (m1) and the monomer (m2) in the monomer component constituting the acrylic polymer is, for example, 76% by weight from the viewpoint of facilitating the effect of these monomers. It may be more than 81% by weight, preferably 86% by weight or more, 91% by weight or more, 96% by weight or more, 99% by weight or more, substantially 100% by weight. But it may be.

　（モノマーｍ３）
　アクリル系ポリマーを構成するモノマー成分は、必要に応じて、上記モノマー（ｍ１）および上記モノマー（ｍ２）以外のモノマーを含んでいてもよい。そのような任意成分の一例として、アルキル（メタ）アクリレート（以下、「モノマー（ｍ３）」ともいう。）が挙げられる。モノマー（ｍ３）は、粘着剤の柔軟性の調整や、粘着剤内における相溶性の改善に役立ち得る。 (Monomer m3)
The monomer component constituting the acrylic polymer may contain a monomer other than the above-mentioned monomer (m1) and the above-mentioned monomer (m2), if necessary. An example of such an optional component is an alkyl (meth) acrylate (hereinafter, also referred to as “monomer (m3)”). The monomer (m3) can be useful for adjusting the flexibility of the pressure-sensitive adhesive and improving the compatibility in the pressure-sensitive adhesive.

　モノマー（ｍ３）としては、炭素原子数１～２０の（すなわち、Ｃ１－２０の）直鎖または分岐鎖状のアルキル基をエステル末端に有するアルキル（メタ）アクリレートが好ましく用いられ得る。Ｃ１－２０アルキル（メタ）アクリレートの具体例としては、（メタ）アクリル酸メチル、（メタ）アクリル酸エチル、（メタ）アクリル酸プロピル、（メタ）アクリル酸イソプロピル、（メタ）アクリル酸ｎ－ブチル、（メタ）アクリル酸イソブチル、（メタ）アクリル酸ｓ－ブチル、（メタ）アクリル酸ｔ－ブチル、（メタ）アクリル酸ペンチル、（メタ）アクリル酸イソペンチル、（メタ）アクリル酸ヘキシル、（メタ）アクリル酸ヘプチル、（メタ）アクリル酸オクチル、（メタ）アクリル酸２－エチルヘキシル、（メタ）アクリル酸イソオクチル、（メタ）アクリル酸ノニル、（メタ）アクリル酸イソノニル、（メタ）アクリル酸デシル、（メタ）アクリル酸イソデシル、（メタ）アクリル酸ウンデシル、（メタ）アクリル酸ドデシル、（メタ）アクリル酸トリデシル、（メタ）アクリル酸テトラデシル、（メタ）アクリル酸ペンタデシル、（メタ）アクリル酸ヘキサデシル、（メタ）アクリル酸ヘプタデシル、（メタ）アクリル酸ステアリル、（メタ）アクリル酸イソステアリル、（メタ）アクリル酸ノナデシル、（メタ）アクリル酸エイコシル等が挙げられるが、これらに限定されない。 As the monomer (m3), an alkyl (meth) acrylate having a linear or branched alkyl group having 1 to 20 carbon atoms (that is, C 1-20) at the ester terminal can be preferably used. Specific examples of C 1-20 alkyl (meth) acrylate include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, isopropyl (meth) acrylate, and n- (meth) acrylate. Butyl, isobutyl (meth) acrylate, s-butyl (meth) acrylate, t-butyl (meth) acrylate, pentyl (meth) acrylate, isopentyl (meth) acrylate, hexyl (meth) acrylate, (meth) ) Heptyl acrylate, octyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, isooctyl (meth) acrylate, nonyl (meth) acrylate, isononyl (meth) acrylate, decyl (meth) acrylate, (meth) Isodecyl acrylate, undecyl (meth) acrylate, dodecyl (meth) acrylate, tridecyl (meth) acrylate, tetradecyl (meth) acrylate, pentadecyl (meth) acrylate, hexadecyl (meth) acrylate, (meth) ) Heptadecyl acrylate, stearyl (meth) acrylate, isostearyl (meth) acrylate, nonadecil (meth) acrylate, eikosyl (meth) acrylate and the like, but are not limited thereto.

　いくつかの態様において、モノマー（ｍ３）の少なくとも一部として、ホモポリマーのＴｇが－２０℃以下（より好ましくは－４０℃以下、例えば－５０℃以下）であるアルキル（メタ）アクリレートを好ましく採用し得る。このような低Ｔｇのアルキル（メタ）アクリレートは、粘着剤の柔軟性の向上に役立ち得る。上記アルキル（メタ）アクリレートのＴｇの下限は特に制限されず、例えば－８５℃以上であってよく、－７５℃以上でもよく、－６５℃以上でもよく、－６０℃以上でもよい。上記低Ｔｇアルキル（メタ）アクリレートの具体例としては、アクリル酸ｎ－ブチル（ＢＡ）、アクリル酸２－エチルヘキシル（２ＥＨＡ）、アクリル酸イソノニル（ｉＮＡ）等が挙げられる。 In some embodiments, alkyl (meth) acrylates having a homopolymer Tg of −20 ° C. or lower (more preferably −40 ° C. or lower, eg, −50 ° C. or lower) are preferably employed as at least a portion of the monomer (m3). Can be done. Such low Tg alkyl (meth) acrylates can help improve the flexibility of the adhesive. The lower limit of Tg of the alkyl (meth) acrylate is not particularly limited, and may be, for example, −85 ° C. or higher, −75 ° C. or higher, −65 ° C. or higher, or −60 ° C. or higher. Specific examples of the low Tg alkyl (meth) acrylate include n-butyl acrylate (BA), 2-ethylhexyl acrylate (2EHA), and isononyl acrylate (iNA).

　モノマー（ｍ３）を使用するいくつかの態様において、柔軟性や粘着性等の観点から、上記モノマー（ｍ３）の少なくとも一部はアルキルアクリレートであることが好ましい。例えば、モノマー（ｍ３）のうち５０重量％以上（より好ましくは７５重量％以上、さらに好ましくは９０重量％以上）がアルキルアクリレートであることが好ましい。モノマー（ｍ３）として１種または２種以上のアルキルアクリレートのみを使用し、アルキルメタクリレートを使用しない態様であってもよい。 In some embodiments where the monomer (m3) is used, it is preferable that at least a part of the monomer (m3) is an alkyl acrylate from the viewpoint of flexibility, adhesiveness and the like. For example, it is preferable that 50% by weight or more (more preferably 75% by weight or more, still more preferably 90% by weight or more) of the monomer (m3) is an alkyl acrylate. It may be an embodiment in which only one kind or two or more kinds of alkyl acrylates are used as the monomer (m3) and no alkyl methacrylate is used.

　モノマー成分がアルキル（メタ）アクリレートを含む態様において、モノマー成分におけるアルキル（メタ）アクリレートの含有量は、その使用効果が適切に発揮されるように設定することができる。いくつかの態様において、上記アルキル（メタ）アクリレートの含有量は、例えば１重量％以上であってよく、３重量％以上でもよく、５重量％以上でもよく、８重量％以上でもよい。いくつかの態様において、上記アルキル（メタ）アクリレートの含有量は、１５重量％以上でもよく、３０重量％以上でもよく、４５重量％以上でもよい。モノマー成分におけるモノマー（ｍ３）の含有量の上限は、他のモノマーの含有量との合計が１００重量％を超えないように設定され、例えば５０重量％未満であり得る。いくつかの態様において、上記モノマー（ｍ３）の含有量は、例えば３５重量％未満であり得る。一般にアルキル（メタ）アクリレートの屈折率は比較的低いため、高屈折率化のためには、モノマー成分におけるモノマー（ｍ３）の含有量を制限し、モノマー（ｍ１）の含有量を相対的に多くすることが有利である。かかる観点から、モノマー（ｍ３）の含有量は、モノマー成分の２４重量％以下であることが有利であり、２３重量％未満であることが好ましく、２０重量％未満であることがより好ましく、１７重量％未満でもよく、１２重量％未満でもよく、７重量％未満でもよく、３重量％未満でもよく、１重量％未満でもよい。モノマー（ｍ３）を実質的に使用しなくてもよい。 In the embodiment in which the monomer component contains an alkyl (meth) acrylate, the content of the alkyl (meth) acrylate in the monomer component can be set so that the effect of use thereof is appropriately exhibited. In some embodiments, the content of the alkyl (meth) acrylate may be, for example, 1% by weight or more, 3% by weight or more, 5% by weight or more, or 8% by weight or more. In some embodiments, the content of the alkyl (meth) acrylate may be 15% by weight or more, 30% by weight or more, or 45% by weight or more. The upper limit of the content of the monomer (m3) in the monomer component is set so that the total content with the content of other monomers does not exceed 100% by weight, and can be, for example, less than 50% by weight. In some embodiments, the content of the monomer (m3) can be, for example, less than 35% by weight. In general, the refractive index of alkyl (meth) acrylate is relatively low. Therefore, in order to increase the refractive index, the content of the monomer (m3) in the monomer component is limited, and the content of the monomer (m1) is relatively large. It is advantageous to do. From this point of view, the content of the monomer (m3) is preferably 24% by weight or less, preferably less than 23% by weight, more preferably less than 20% by weight, 17% by weight of the monomer component. It may be less than% by weight, less than 12% by weight, less than 7% by weight, less than 3% by weight, or less than 1% by weight. It is not necessary to use the monomer (m3) substantially.

　（その他のモノマー）
　アクリル系ポリマーを構成するモノマー成分は、必要に応じて、上記モノマー（ｍ１）、（ｍ２）、（ｍ３）以外のモノマー（以下、「その他モノマー」という。）を含んでいてもよい。上記その他モノマーは、例えば、アクリル系ポリマーのＴｇ調整、粘着性能の調整、粘着剤層内における相溶性の改善等の目的で使用することができる。上記その他モノマーは、１種を単独でまたは２種以上を組み合わせて用いることができる。 (Other monomers)
The monomer component constituting the acrylic polymer may contain a monomer other than the above-mentioned monomers (m1), (m2), and (m3) (hereinafter, referred to as "other monomer"), if necessary. The above-mentioned other monomers can be used, for example, for the purpose of adjusting Tg of an acrylic polymer, adjusting the adhesive performance, improving the compatibility in the pressure-sensitive adhesive layer, and the like. The above-mentioned other monomers may be used alone or in combination of two or more.

　上記その他モノマーの例として、水酸基およびカルボキシ基以外の官能基を有するモノマー（官能基含有モノマー）が挙げられる。例えば、粘着剤の凝集力や耐熱性を向上させ得るその他モノマーとして、スルホン酸基含有モノマー、リン酸基含有モノマー、シアノ基含有モノマー等が挙げられる。また、アクリル系ポリマーに架橋基点となり得る官能基を導入することができ、あるいは剥離強度の向上や粘着剤層内における相溶性の改善に寄与し得るモノマーとして、アミド基含有モノマー（例えば、（メタ）アクリルアミド、Ｎ－メチロール（メタ）アクリルアミド等）、アミノ基含有モノマー（例えば、アミノエチル（メタ）アクリレート、Ｎ，Ｎ－ジメチルアミノエチル（メタ）アクリレート等）、窒素原子含有環を有するモノマー（例えば、Ｎ－ビニル－２－ピロリドン、Ｎ－（メタ）アクリロイルモルホリン等）、イミド基含有モノマー、エポキシ基含有モノマー、ケト基含有モノマー、イソシアネート基含有モノマー、アルコキシシリル基含有モノマー等が挙げられる。なお、窒素原子含有環を有するモノマーのなかには、例えばＮ－ビニル－２－ピロリドンのように、アミド基含有モノマーにも該当するものがある。上記窒素原子含有環を有するモノマーとアミノ基含有モノマーとの関係についても同様である。 Examples of the above-mentioned other monomers include monomers having functional groups other than hydroxyl groups and carboxy groups (functional group-containing monomers). For example, other monomers that can improve the cohesive force and heat resistance of the pressure-sensitive adhesive include sulfonic acid group-containing monomers, phosphoric acid group-containing monomers, and cyano group-containing monomers. Further, as a monomer capable of introducing a functional group that can serve as a cross-linking base point into the acrylic polymer, or contributing to improvement of peel strength and compatibility in the pressure-sensitive adhesive layer, an amide group-containing monomer (for example, (meth). ) Acrylamide, N-methylol (meth) acrylamide, etc.), amino group-containing monomer (for example, aminoethyl (meth) acrylate, N, N-dimethylaminoethyl (meth) acrylate, etc.), monomer having a nitrogen atom-containing ring (for example, , N-vinyl-2-pyrrolidone, N- (meth) acryloylmorpholine, etc.), imide group-containing monomer, epoxy group-containing monomer, keto group-containing monomer, isocyanate group-containing monomer, alkoxysilyl group-containing monomer, and the like. In addition, among the monomers having a nitrogen atom-containing ring, there is also a monomer corresponding to an amide group-containing monomer such as N-vinyl-2-pyrrolidone. The same applies to the relationship between the monomer having a nitrogen atom-containing ring and the amino group-containing monomer.

　上記官能基含有モノマー以外で使用し得るその他モノマーとしては、酢酸ビニル等のビニルエステル系モノマー；シクロヘキシル（メタ）アクリレート、イソボルニル（メタ）アクリレート等の非芳香族性環含有（メタ）アクリレート；エチレン、ブタジエン、イソブチレン等のオレフィン系モノマー；塩化ビニル等の塩素含有モノマー；メトキシエチル（メタ）アクリレート、エトキシエチル（メタ）アクリレート、エトキシエトキシエチル（メタ）アクリレート等のアルコキシ基含有モノマー；メチルビニルエーテル等のビニルエーテル系モノマー；等が挙げられる。粘着剤の柔軟性向上等の目的で使用し得るその他モノマーの一好適例として、エトキシエトキシエチルアクリレート（別名：エチルカルビトールアクリレート、ホモポリマーのＴｇ：－６７℃）が挙げられる。 Other monomers that can be used other than the above functional group-containing monomers include vinyl ester-based monomers such as vinyl acetate; non-aromatic ring-containing (meth) acrylates such as cyclohexyl (meth) acrylate and isobornyl (meth) acrylate; ethylene, Olefin-based monomers such as butadiene and isobutylene; Chlorine-containing monomers such as vinyl chloride; alkoxy group-containing monomers such as methoxyethyl (meth) acrylate, ethoxyethyl (meth) acrylate and ethoxyethoxyethyl (meth) acrylate; Vinyl ether such as methyl vinyl ether System monomers; and the like. As one preferable example of other monomers that can be used for the purpose of improving the flexibility of the pressure-sensitive adhesive, ethoxyethoxyethyl acrylate (also known as ethyl carbitol acrylate, homopolymer Tg: −67 ° C.) can be mentioned.

　上記その他モノマーを使用する場合、その使用量は特に制限されず、モノマー成分の合計量が１００重量％を超えない範囲で適宜設定し得る。いくつかの態様において、モノマー（ｍ１）の使用による屈折率向上効果を発揮しやすくする観点から、モノマー成分における上記その他モノマーの含有量は、例えば凡そ３５重量％以下とすることができ、凡そ２５重量％以下（例えば０～２５重量％）とすることが適当であり、凡そ２０重量％以下（例えば０～２０重量％）でもよく、凡そ１０重量％以下でもよく、凡そ５重量％以下でもよく、例えば凡そ１重量％以下でもよい。ここに開示される技術は、モノマー成分が上記その他のモノマーを実質的に含まない態様で好ましく実施され得る。 When the above-mentioned other monomers are used, the amount used is not particularly limited, and can be appropriately set within a range in which the total amount of the monomer components does not exceed 100% by weight. In some embodiments, the content of the other monomer in the monomer component can be, for example, about 35% by weight or less, and is about 25, from the viewpoint of facilitating the effect of improving the refractive index by using the monomer (m1). It is appropriate to set it to about 20% by weight or less (for example, 0 to 25% by weight), and it may be about 20% by weight or less (for example, 0 to 20% by weight), about 10% by weight or less, or about 5% by weight or less. For example, it may be about 1% by weight or less. The technique disclosed herein can be preferably carried out in a manner in which the monomer component is substantially free of the other monomers.

　いくつかの態様において、アクリル系ポリマーを構成するモノマー成分は、メタクリロイル基含有モノマーの使用量が所定以下に抑えられた組成であり得る。モノマー成分におけるメタクリロイル基含有モノマーの使用量は、例えば５重量％未満であってよく、３重量％未満でもよく、１重量％未満でもよく、０．５重量％未満でもよい。このようにメタクリロイル基含有モノマーの使用量を制限することは、柔軟性や粘着性と高屈折率とをバランスよく両立させた粘着剤を実現する観点から有利となり得る。アクリル系ポリマーを構成するモノマー成分は、メタクリロイル基含有モノマーを含まない組成（例えば、アクリロイル基含有モノマーのみからなる組成）であってもよい。 In some embodiments, the monomer component constituting the acrylic polymer may have a composition in which the amount of the methacryloyl group-containing monomer used is suppressed to a predetermined value or less. The amount of the methacryloyl group-containing monomer used in the monomer component may be, for example, less than 5% by weight, less than 3% by weight, less than 1% by weight, or less than 0.5% by weight. Limiting the amount of the methacryloyl group-containing monomer used in this way can be advantageous from the viewpoint of realizing a pressure-sensitive adhesive having both flexibility and adhesiveness and a high refractive index in a well-balanced manner. The monomer component constituting the acrylic polymer may have a composition that does not contain a methacryloyl group-containing monomer (for example, a composition consisting of only an acryloyl group-containing monomer).

　いくつかの態様において、粘弾性層Ｖ１のベースポリマー（例えば、アクリル系ポリマー）を構成するモノマー成分は、該粘弾性層Ｖ１の着色または変色（例えば黄変）を抑制する観点から、カルボキシ基含有モノマーの使用量が制限されていることが好ましい。モノマー成分におけるカルボキシ基含有モノマーの使用量は、例えば１重量％未満であってよく、０．５重量％未満であることが好ましく、０．３重量％未満であることがより好ましく、０．１重量％未満でもよく、０．０５重量％未満でもよい。このようにカルボキシ基含有モノマーの使用量が制限されていることは、粘弾性層Ｖ１に接触または近接して配置され得る金属材料（例えば、被着体上に存在し得る金属配線や金属膜等）の腐食を抑制する観点からも有利である。ここに開示される層間シートは、上記モノマー成分がカルボキシ基含有モノマーを含有しない態様で好ましく実施され得る。
　同様の理由から、いくつかの態様において、粘弾性層Ｖ１のベースポリマーを構成するモノマー成分は、酸性官能基（カルボキシ基の他、スルホン酸基、リン酸基等を包含する。）を有するモノマーの使用量が制限されていることが好ましい。かかる態様のモノマー成分における酸性官能基含有モノマーの使用量としては、上述したカルボキシ基含有モノマーの好ましい使用量を適用することができる。ここに開示される層間シートは、上記モノマー成分が酸性基含有モノマーを含有しない態様（すなわち粘弾性層Ｖ１のベースポリマーが酸フリーである態様）で好ましく実施され得る。 In some embodiments, the monomer components constituting the base polymer of the viscoelastic layer V 1 (e.g., acrylic polymers), from the viewpoint of suppressing coloration or discoloration of the viscoelastic layer V 1 (e.g., yellowing), carboxy It is preferable that the amount of the group-containing monomer used is limited. The amount of the carboxy group-containing monomer used in the monomer component may be, for example, less than 1% by weight, preferably less than 0.5% by weight, more preferably less than 0.3% by weight, and 0.1. It may be less than% by weight or less than 0.05% by weight. Thus the amount of carboxyl group-containing monomer is restricted, the metallic material may be disposed in contact or in proximity to the viscoelastic layer V 1 (e.g., a metal wire or a metal film that may be present on an adherend Etc.), which is also advantageous from the viewpoint of suppressing corrosion. The interlayer sheet disclosed herein can be preferably carried out in a manner in which the above-mentioned monomer component does not contain a carboxy group-containing monomer.
For the same reasons, in some embodiments, the monomer components constituting the base polymer of the viscoelastic layer V 1 was, has (other carboxyl group, a sulfonic acid group includes a phosphoric acid group.) Acidic functional groups It is preferable that the amount of the monomer used is limited. As the amount of the acidic functional group-containing monomer used in the monomer component of such an embodiment, the above-mentioned preferable amount of the carboxy group-containing monomer can be applied. Interlayer sheet disclosed herein may be preferably carried out in the manner described above monomer component does not contain an acidic group-containing monomer (i.e. aspect based polymer is an acid-free viscoelastic layer V 1).

　（ベースポリマーのガラス転移温度ＴｇＴ）
　いくつかの態様において、粘着剤層のベースポリマー（例えば、アクリル系ポリマー）は、該ポリマーを構成するモノマー成分の組成に基づくガラス転移温度ＴｇＴが、凡そ２０℃以下であることが適当であり、凡そ１０℃以下であることが好ましく、０℃以下であることがより好ましく、－１０℃以下でもよく、－２０℃以下でもよく、－２５℃以下でもよく、－２８℃以下でもよく、－３０℃以下でもよい。ガラス転移温度ＴｇＴが低いことは、粘着剤の柔軟性向上の観点から有利となり得る。また、ガラス転移温度ＴｇＴは、例えば－６０℃以上であってよく、粘着剤の高屈折率化を容易とする観点から、好ましくは－５０℃以上であり、より好ましくは－４５℃超であり、－４０℃超であってもよく、－３５℃超であってもよく、－２５℃超であってもよく、－１５℃以上であってもよく、－５℃以上であってもよい。 (Glass transition temperature of base polymer Tg T )
In some embodiments, the base polymer of the pressure-sensitive adhesive layer (eg, an acrylic polymer) preferably has a glass transition temperature Tg T based on the composition of the monomer components constituting the polymer, which is approximately 20 ° C. or lower. , Approximately 10 ° C or lower, more preferably 0 ° C or lower, -10 ° C or lower, -20 ° C or lower, -25 ° C or lower, −28 ° C or lower, −28 ° C or lower, − It may be 30 ° C. or lower. A low glass transition temperature Tg T can be advantageous from the viewpoint of improving the flexibility of the pressure-sensitive adhesive. The glass transition temperature Tg T may be, for example, −60 ° C. or higher, preferably −50 ° C. or higher, and more preferably −45 ° C. or higher, from the viewpoint of facilitating high refractive index of the pressure-sensitive adhesive. Yes, it may be above -40 ° C, above -35 ° C, above -25 ° C, above -15 ° C, or above -5 ° C. good.

　ここで、ポリマーのガラス転移温度ＴｇＴとは、特記しない場合、該ポリマーを構成するモノマー成分の組成に基づいて、Ｆｏｘの式により求められるガラス転移温度をいう。Ｆｏｘの式とは、以下に示すように、共重合体のＴｇと、該共重合体を構成するモノマーのそれぞれを単独重合したホモポリマーのガラス転移温度Ｔｇｉとの関係式である。
　　　１／Ｔｇ＝Σ（Ｗｉ／Ｔｇｉ）
　上記Ｆｏｘの式において、Ｔｇは共重合体のガラス転移温度（単位：Ｋ）、Ｗｉは該共重合体におけるモノマーｉの重量分率（重量基準の共重合割合）、Ｔｇｉはモノマーｉのホモポリマーのガラス転移温度（単位：Ｋ）を表す。
　Ｔｇの算出に使用するホモポリマーのガラス転移温度としては、「Polymer Handbook」（第３版、John Wiley & Sons, Inc., 1989年）等の公知資料に記載の値を用いるものとする。上記Polymer Handbookに複数種類の値が記載されているモノマーについては、最も高い値を採用する。公知資料にホモポリマーのＴｇが記載されていない場合は、日本国特許出願公開２００７－５１２７１号公報に記載の測定方法により得られる値を用いるものとする。 Here, the glass transition temperature Tg T of the polymer means the glass transition temperature obtained by the Fox formula based on the composition of the monomer components constituting the polymer, unless otherwise specified. As shown below, the Fox formula is a relational expression between the Tg of the copolymer and the glass transition temperature Tgi of the homopolymer in which each of the monomers constituting the copolymer is homopolymerized.
1 / Tg = Σ (Wi / Tgi)
In the Fox formula, Tg is the glass transition temperature (unit: K) of the copolymer, Wi is the weight fraction of the monomer i in the copolymer (copolymerization ratio based on the weight), and Tgi is the homopolymer of the monomer i. Represents the glass transition temperature (unit: K) of.
As the glass transition temperature of the homopolymer used for calculating Tg, the values described in publicly known materials such as "Polymer Handbook" (3rd edition, John Wiley & Sons, Inc., 1989) shall be used. For the monomers whose multiple types of values are described in the Polymer Handbook, the highest value is adopted. When the Tg of the homopolymer is not described in the publicly known material, the value obtained by the measuring method described in Japanese Patent Application Publication No. 2007-51271 shall be used.

　（ベースポリマーの調製方法）
　ここに開示される技術において、粘着剤層のベースポリマー（例えば、上述のようなモノマー成分により構成されたアクリル系ポリマー（Ａ））を得る方法は特に限定されず、溶液重合法、エマルション重合法、バルク重合法、懸濁重合法、光重合法等の公知の重合方法を適宜採用することができる。いくつかの態様において、溶液重合法を好ましく採用し得る。溶液重合を行う際の重合温度は、使用するモノマーおよび溶媒の種類、重合開始剤の種類等に応じて適宜選択することができ、例えば２０℃～１７０℃程度（典型的には４０℃～１４０℃程度）とすることができる。 (Preparation method of base polymer)
In the technique disclosed herein, the method for obtaining the base polymer of the pressure-sensitive adhesive layer (for example, the acrylic polymer (A) composed of the above-mentioned monomer components) is not particularly limited, and is a solution polymerization method or an emulsion polymerization method. , A known polymerization method such as a bulk polymerization method, a suspension polymerization method, and a photopolymerization method can be appropriately adopted. In some embodiments, the solution polymerization method may be preferably employed. The polymerization temperature at the time of solution polymerization can be appropriately selected depending on the type of monomer and solvent used, the type of polymerization initiator, etc., and is, for example, about 20 ° C. to 170 ° C. (typically 40 ° C. to 140 ° C.). ℃).

　溶液重合に用いる溶媒（重合溶媒）は、従来公知の有機溶媒から適宜選択することができる。例えば、トルエン等の芳香族化合物類（典型的には芳香族炭化水素類）；酢酸エチル等の酢酸エステル類；ヘキサンやシクロヘキサン等の脂肪族または脂環式炭化水素類；１，２－ジクロロエタン等のハロゲン化アルカン類；イソプロピルアルコール等の低級アルコール類（例えば、炭素原子数１～４の一価アルコール類）；ｔｅｒｔ－ブチルメチルエーテル等のエーテル類；メチルエチルケトン等のケトン類；等から選択されるいずれか１種の溶媒、または２種以上の混合溶媒を用いることができる。 The solvent (polymerization solvent) used for solution polymerization can be appropriately selected from conventionally known organic solvents. For example, aromatic compounds such as toluene (typically aromatic hydrocarbons); acetate esters such as ethyl acetate; aliphatic or alicyclic hydrocarbons such as hexane and cyclohexane; 1,2-dichloroethane and the like. Alkanes halogenated; lower alcohols such as isopropyl alcohol (for example, monohydric alcohols having 1 to 4 carbon atoms); ethers such as tert-butyl methyl ether; ketones such as methyl ethyl ketone; etc. Any one kind of solvent or two or more kinds of mixed solvents can be used.

　重合に用いる開始剤は、重合方法の種類に応じて、従来公知の重合開始剤から適宜選択することができる。例えば、２，２’－アゾビスイソブチロニトリル（ＡＩＢＮ）等のアゾ系重合開始剤の１種または２種以上を好ましく使用し得る。重合開始剤の他の例としては、過硫酸カリウム等の過硫酸塩；ベンゾイルパーオキサイド、過酸化水素等の過酸化物系開始剤；フェニル置換エタン等の置換エタン系開始剤；芳香族カルボニル化合物；等が挙げられる。重合開始剤のさらに他の例として、過酸化物と還元剤との組み合わせによるレドックス系開始剤が挙げられる。重合開始剤は、１種を単独でまたは２種以上を組み合わせて使用することができる。重合開始剤の使用量は、通常の使用量であればよく、例えば、モノマー成分１００重量部に対して凡そ０．００５～１重量部程度（典型的には凡そ０．０１～１重量部程度）の範囲から選択することができる。 The initiator used for polymerization can be appropriately selected from conventionally known polymerization initiators according to the type of polymerization method. For example, one or more azo-based polymerization initiators such as 2,2'-azobisisobutyronitrile (AIBN) can be preferably used. Other examples of polymerization initiators include persulfates such as potassium persulfate; peroxide-based initiators such as benzoyl peroxide and hydrogen peroxide; substituted ethane-based initiators such as phenyl-substituted ethane; aromatic carbonyl compounds. ; Etc. can be mentioned. Yet another example of the polymerization initiator is a redox-based initiator that is a combination of a peroxide and a reducing agent. The polymerization initiator may be used alone or in combination of two or more. The amount of the polymerization initiator used may be a normal amount, for example, about 0.005 to 1 part by weight (typically about 0.01 to 1 part by weight) with respect to 100 parts by weight of the monomer component. ) Can be selected.

　上記重合には、必要に応じて、従来公知の各種の連鎖移動剤を使用することができる。例えば、ｎ－ドデシルメルカプタン、ｔ－ドデシルメルカプタン、チオグリコール酸、α－チオグリセロール等のメルカプタン類を用いることができる。あるいは、硫黄原子を含まない連鎖移動剤（非硫黄系連鎖移動剤）を用いてもよい。非硫黄系連鎖移動剤の例としては、Ｎ，Ｎ－ジメチルアニリン、Ｎ，Ｎ－ジエチルアニリン等のアニリン類；α－ピネン、ターピノーレン等のテルペノイド類；α－メチルスチレン、α－メチルスチレンダイマー等のスチレン類；等が挙げられる。連鎖移動剤は、１種を単独でまたは２種以上を組み合わせて用いることができる。連鎖移動剤を使用する場合における使用量は、モノマー原料１００重量部に対して、例えば凡そ０．０１～１重量部程度とすることができる。 Various conventionally known chain transfer agents can be used for the above polymerization, if necessary. For example, mercaptans such as n-dodecyl mercaptan, t-dodecyl mercaptan, thioglycolic acid, and α-thioglycerol can be used. Alternatively, a chain transfer agent containing no sulfur atom (non-sulfur chain transfer agent) may be used. Examples of non-sulfur chain transfer agents include anilines such as N, N-dimethylaniline and N, N-diethylaniline; terpenoids such as α-pinene and turpinolene; α-methylstyrene, α-methylstyrene dimer and the like. Styrenes; etc. The chain transfer agent may be used alone or in combination of two or more. When the chain transfer agent is used, the amount used can be, for example, about 0.01 to 1 part by weight with respect to 100 parts by weight of the monomer raw material.

　ベースポリマーの重量平均分子量（Ｍｗ）は、特に限定されず、例えば凡そ１０×１０４～５００×１０４の範囲であり得る。粘着性能の観点から、ベースポリマーのＭｗは、凡そ２０×１０４～４００×１０４（より好ましくは凡そ３０×１０４～１５０×１０４、例えば凡そ５０×１０４～１３０×１０４）の範囲にあることが好ましい。 The weight average molecular weight (Mw) of the base polymer is not particularly limited, and may be in the range of , for example, approximately 10 × 10 4 to 500 × 10 4. From the viewpoint of adhesive performance, the Mw of the base polymer is about 20 × 10 4 to 400 × 10 4 (more preferably about 30 × 10 4 to 150 × 10 4 , for example, about 50 × 10 4 to 130 × 10 4 ). It is preferably in the range.

　ここで、ポリマーのＭｗは、ゲルパーミエーションクロマトグラフィー（ＧＰＣ）によりポリスチレン換算して求めることができる。具体的には、ＧＰＣ測定装置として商品名「ＨＬＣ－８２２０ＧＰＣ」（東ソー社製）を用いて、下記の条件で測定して求めることができる。
　　［ＧＰＣの測定条件］
　サンプル濃度：０．２重量％（テトラヒドロフラン溶液）
　サンプル注入量：１０μＬ
　溶離液：テトラヒドロフラン（ＴＨＦ）
　流量（流速）：０．６ｍＬ／分
　カラム温度（測定温度）：４０℃
　カラム：
　　サンプルカラム：商品名「ＴＳＫｇｕａｒｄｃｏｌｕｍｎ　ＳｕｐｅｒＨＺ－Ｈ」１本＋商品名「ＴＳＫｇｅｌ　ＳｕｐｅｒＨＺＭ－Ｈ」２本」（東ソー社製）
　　リファレンスカラム：商品名「ＴＳＫｇｅｌ　ＳｕｐｅｒＨ－ＲＣ」１本（東ソー社製）
　検出器：示差屈折計（ＲＩ）
　標準試料：ポリスチレン Here, the Mw of the polymer can be determined by gel permeation chromatography (GPC) in terms of polystyrene. Specifically, it can be obtained by measuring under the following conditions using the trade name "HLC-8220 GPC" (manufactured by Tosoh Corporation) as the GPC measuring device.
[GPC measurement conditions]
Sample concentration: 0.2% by weight (tetrahydrofuran solution)
Sample injection volume: 10 μL
Eluent: tetrahydrofuran (THF)
Flow rate (flow velocity): 0.6 mL / min Column temperature (measurement temperature): 40 ° C
column:
Sample column: 1 product name "TSKguardcolum SuperHZ-H" + 2 product name "TSKgel SuperHZM-H" (manufactured by Tosoh Corporation)
Reference column: 1 product name "TSKgel SuperH-RC" (manufactured by Tosoh Corporation)
Detector: Differential Refractometer (RI)
Standard sample: polystyrene

　（屈折率向上剤）
　ここに開示される技術のいくつかの態様において、粘着剤層Ｖ１（例えば、アクリル系粘着剤層）には、ベースポリマーに加えて、必要に応じて屈折率向上剤を含有させ得る。ここで、本明細書において屈折率向上剤とは、その使用により粘着剤層の屈折率を高めることのできる材料をいう。屈折率向上剤としては、該屈折率向上剤を含む粘着剤層の屈折率よりも高屈折率の材料が好ましく用いられ得る。また、屈折率向上剤としては、該屈折率向上剤を含む粘着剤層のベースポリマー（例えば、アクリル系ポリマー（Ａ））よりも高屈折率の材料が好ましく用いられ得る。屈折率向上剤の適切な使用により、より高い屈折率と、実用的な粘着性能とを好適に両立し得る。いくつかの態様において、屈折率向上剤は有機材料であることが好ましい。屈折率向上剤として用いられる有機材料は、重合体であってもよく、非重合体であってもよい。また、重合性官能基を有していてもよく、有していなくてもよい。屈折率向上剤は、１種を単独でまたは２種以上を組み合わせて用いることができる。 (Refractive index improver)
In some embodiments of the technology disclosed herein, the pressure-sensitive adhesive layer V 1 (e.g., acrylic pressure-sensitive adhesive layer), in addition to the base polymer may contain a refractive index enhancing agent, if necessary. Here, the refractive index improving agent in the present specification means a material capable of increasing the refractive index of the pressure-sensitive adhesive layer by its use. As the refractive index improver, a material having a refractive index higher than that of the pressure-sensitive adhesive layer containing the refractive index improver can be preferably used. Further, as the refractive index improving agent, a material having a higher refractive index than the base polymer (for example, the acrylic polymer (A)) of the pressure-sensitive adhesive layer containing the refractive index improving agent can be preferably used. With proper use of the refractive index improver, a higher refractive index and practical adhesive performance can be suitably compatible. In some embodiments, the refractive index improver is preferably an organic material. The organic material used as the refractive index improver may be a polymer or a non-polymer. Further, it may or may not have a polymerizable functional group. The refractive index improver may be used alone or in combination of two or more.

　屈折率向上剤（例えば、後述する添加剤（ＨＲＯ））の屈折率は、ベースポリマーの屈折率との相対関係で適当な範囲に設定し得るので、特定の範囲に限定されない。屈折率向上剤の屈折率は、例えば１．５５超、１．５６超または１．５７超であって、かつベースポリマーの屈折率より高い範囲から選択し得る。粘着剤の高屈折率化の観点から、いくつかの態様において、屈折率向上剤の屈折率は、１．５８以上であることが有利であり、１．６０以上であることが好ましく、１．６３以上であることがより好ましく、１．６５以上でもよく、１．７０以上でもよく、１．７５以上でもよい。より屈折率の高い屈折率向上剤によると、より少量の屈折率向上剤の使用によっても目的の屈折率を達成し得る。このことは粘着特性や光学特性の低下抑制の観点から好ましい。屈折率向上剤の屈折率の上限は特に制限されないが、粘着剤内における相溶性や、高屈折率化と粘着剤として適した柔軟性との両立容易性等の観点から、例えば３．０００以下であり、２．５００以下でもよく、２．０００以下でもよく、１．９５０以下でもよく、１．９００以下でもよく、１．８５０以下でもよい。 The refractive index of the refractive index improver (for example, the additive (H RO ) described later) can be set in an appropriate range in relation to the refractive index of the base polymer, and is not limited to a specific range. The refractive index of the refractive index improver can be selected from, for example, more than 1.55, more than 1.56 or more than 1.57, and higher than the refractive index of the base polymer. From the viewpoint of increasing the refractive index of the pressure-sensitive adhesive, in some embodiments, the refractive index of the refractive index improver is preferably 1.58 or more, preferably 1.60 or more. It is more preferably 63 or more, 1.65 or more, 1.70 or more, or 1.75 or more. According to the refractive index improver having a higher refractive index, the desired refractive index can be achieved by using a smaller amount of the refractive index improver. This is preferable from the viewpoint of suppressing deterioration of adhesive properties and optical properties. The upper limit of the refractive index of the refractive index improver is not particularly limited, but from the viewpoint of compatibility in the pressure-sensitive adhesive and the ease of compatibility between high refractive index and flexibility suitable as a pressure-sensitive adhesive, for example, 3.000 or less. It may be 2.500 or less, 2.000 or less, 1.950 or less, 1.900 or less, or 1.850 or less.

　いくつかの態様において、屈折率向上剤（例えば、後述する添加剤（ＨＲＯ））の屈折率ｎｂとベースポリマーの屈折率ｎａとの差、すなわちｎｂ－ｎａ（以下、「ΔｎＡ」ともいう。）は、０より大きくなるように設定される。いくつかの態様において、ΔｎＡは、例えば０．０２以上であり、０．０５以上でもよく、０．０７以上でもよく、０．１０以上でもよく、０．１５以上でもよく、０．２０以上または０．２５以上でもよい。ΔｎＡがより大きくなるようにベースポリマーおよび屈折率向上剤を選択することにより、屈折率向上剤の使用による屈折率向上効果は高くなる傾向にある。また、粘着剤層内における相溶性や、粘着剤層の透明性等の観点から、いくつかの態様において、ΔｎＡは、例えば０．７０以下であってよく、０．６０以下でもよく、０．５０以下でもよく、０．４０以下または０．３５以下でもよい。 In some embodiments, the refractive index improvers (e.g., later-described additives (H RO)) difference between the refractive index n a of the refractive index n b and the base polymer, i.e. n b -n a (hereinafter, "Δn A ”) is set to be greater than 0. In some embodiments, Δn A is, for example, 0.02 or greater, 0.05 or greater, 0.07 or higher, 0.10 or higher, 0.15 or higher, 0.20 or higher. Alternatively, it may be 0.25 or more. By selecting the base polymer and the refractive index improver so that Δn A becomes larger, the effect of improving the refractive index by using the refractive index improver tends to be higher. Further, from the viewpoint of compatibility in the pressure-sensitive adhesive layer, transparency of the pressure-sensitive adhesive layer, and the like, Δn A may be, for example, 0.70 or less, 0.60 or less, or 0 in some embodiments. It may be .50 or less, 0.40 or less, or 0.35 or less.

　いくつかの態様において、屈折率向上剤（例えば、後述する添加剤（ＨＲＯ））の屈折率ｎｂと、該屈折率向上剤を含む粘着剤層の屈折率ｎＴとの差、すなわちｎｂ－ｎＴ（以下、「ΔｎＢ」ともいう。）は、０より大きくなるように設定される。いくつかの態様において、ΔｎＢは、例えば０．０２以上であり、０．０５以上でもよく、０．０７以上でもよく、０．１０以上でもよく、０．１５以上でもよく、０．２０以上または０．２５以上でもよい。ΔｎＢがより大きくなるように粘着剤層の組成および屈折率向上剤を選択することにより、屈折率向上剤の使用による屈折率向上効果は高くなる傾向にある。また、粘着剤層内における相溶性や、粘着剤層の透明性等の観点から、いくつかの態様において、ΔｎＢは、例えば０．７０以下であってよく、０．６０以下でもよく、０．５０以下でもよく、０．４０以下または０．３５以下でもよい。 In some embodiments, the difference between the refractive index n b of the refractive index improver (eg, additive (H RO ) described below) and the refractive index n T of the pressure-sensitive adhesive layer containing the refractive index improver, i.e. n b n T (hereinafter, also referred to as “Δn B ”) is set to be larger than 0. In some embodiments, Δn B is, for example, 0.02 or greater, 0.05 or greater, 0.07 or higher, 0.10 or higher, 0.15 or higher, 0.20 or higher. Alternatively, it may be 0.25 or more. By selecting the composition of the pressure-sensitive adhesive layer and the refractive index improver so that Δn B becomes larger, the effect of improving the refractive index by using the refractive index improver tends to be higher. Further, from the viewpoint of compatibility in the pressure-sensitive adhesive layer, transparency of the pressure-sensitive adhesive layer, and the like, Δn B may be, for example, 0.70 or less, 0.60 or less, or 0 in some embodiments. It may be .50 or less, 0.40 or less, or 0.35 or less.

　ベースポリマー１００重量部に対する屈折率向上剤の使用量（複数種の屈折率向上剤を用いる場合は、それらの合計量）は、特に限定されず、目的に応じて設定することができる。粘着剤の高屈折率化の観点から、ベースポリマー１００重量部に対する屈折率向上剤の使用量は、例えば１重量部以上とすることができ、３重量部以上とすることが有利であり、５重量部以上とすることが好ましく、７重量部以上でもよく、１０重量部以上でもよく、１５重量部以上でもよく、２０重量部以上でもよい。また、いくつかの態様において、ベースポリマー１００重量部に対する屈折率向上剤の使用量は、例えば８０重量部以下とすることができ、粘着剤の高屈折率化と粘着特性や光学特性の低下抑制とをバランスよく両立する観点から、６０重量部以下とすることが有利であり、４５重量部以下とすることが好ましい。より粘着特性や光学特性を重視するいくつかの態様において、ベースポリマー１００重量部に対する屈折率向上剤の使用量は、例えば３０重量部以下であってよく、２０重量部以下でもよく、１５重量部以下でもよく、１０重量部以下でもよく、５重量部以下でもよく、３重量部以下でもよい。ここに開示される技術は、粘着剤層におけるベースポリマー１００重量部に対する屈折率向上剤の使用量が１重量部未満であるか、または屈折率向上剤を実質的に使用しない態様でも好ましく実施することができる。ここで、実質的に使用しないとは、少なくとも意図的には使用しないことをいう。 The amount of the refractive index improver used with respect to 100 parts by weight of the base polymer (when a plurality of types of refractive index improvers are used, the total amount thereof) is not particularly limited and can be set according to the purpose. From the viewpoint of increasing the refractive index of the pressure-sensitive adhesive, the amount of the refractive index improver used with respect to 100 parts by weight of the base polymer can be, for example, 1 part by weight or more, and it is advantageous to use 3 parts by weight or more. It is preferably 7 parts by weight or more, 10 parts by weight or more, 15 parts by weight or more, or 20 parts by weight or more. Further, in some embodiments, the amount of the refractive index improver used with respect to 100 parts by weight of the base polymer can be, for example, 80 parts by weight or less, so that the refractive index of the pressure-sensitive adhesive is increased and the deterioration of the pressure-sensitive adhesive properties and the optical properties is suppressed. From the viewpoint of achieving a good balance between the above and the like, it is advantageous to use 60 parts by weight or less, and preferably 45 parts by weight or less. In some embodiments where more adhesive properties and optical properties are emphasized, the amount of the refractive index improver used with respect to 100 parts by weight of the base polymer may be, for example, 30 parts by weight or less, 20 parts by weight or less, or 15 parts by weight. It may be 10 parts by weight or less, 5 parts by weight or less, or 3 parts by weight or less. The technique disclosed herein is preferably carried out even in an embodiment in which the amount of the refractive index improver used in 100 parts by weight of the base polymer in the pressure-sensitive adhesive layer is less than 1 part by weight, or the refractive index improver is substantially not used. be able to. Here, "not practically used" means that it is not used at least intentionally.

　（添加剤（ＨＲＯ））
　いくつかの態様において、屈折率向上剤としては、ベースポリマーよりも高屈折率の有機材料を好ましく採用し得る。以下、このような有機材料を「添加剤（ＨＲＯ）」と表記することがある。ここで、上記「ＨＲＯ」は、高屈折率（High Refractive index）の有機材料（Organic material）であることを表す。ベースポリマー（例えばアクリル系ポリマー、好ましくはアクリル系ポリマー（Ａ））と添加剤（ＨＲＯ）とを組み合わせて用いることにより、屈折率と粘着特性（剥離強度、柔軟性等）および／または光学特性（全光線透過率、ヘイズ値等）とをより好適に両立する粘着剤を実現し得る。添加剤（ＨＲＯ）として用いられる有機材料は、重合体であってもよく、非重合体であってもよい。また、重合性官能基を有していてもよく、有していなくてもよい。添加剤（ＨＲＯ）は、１種を単独でまたは２種以上を組み合わせて用いることができる。 (Additive (H RO ))
In some embodiments, the refractive index improver may preferably be an organic material having a higher refractive index than the base polymer. Hereinafter, such an organic material may be referred to as "additive (HRO)". Here, the above-mentioned "H RO " represents an organic material having a high refractive index. By using a base polymer (for example, an acrylic polymer, preferably an acrylic polymer (A)) in combination with an additive (HRO ), the refractive index and adhesive properties (peeling strength, flexibility, etc.) and / or optical properties can be used. It is possible to realize an adhesive that more preferably balances (total light transmittance, haze value, etc.). The organic material used as an additive ( HRO ) may be a polymer or a non-polymer. Further, it may or may not have a polymerizable functional group. The additive (H RO ) may be used alone or in combination of two or more.

　添加剤（ＨＲＯ）の屈折率は、モノマーの屈折率と同様に、アッベ屈折率計を用いて、測定波長５８９ｎｍ、測定温度２５℃の条件で測定される。メーカー等から２５℃における屈折率の公称値が提供されている場合は、その公称値を採用することができる。 The refractive index of the additive (H RO ) is measured using an Abbe refractive index meter under the conditions of a measurement wavelength of 589 nm and a measurement temperature of 25 ° C., similarly to the refractive index of the monomer. If the manufacturer or the like provides a nominal value of the refractive index at 25 ° C., the nominal value can be adopted.

　添加剤（ＨＲＯ）として使用する有機材料の分子量は、特に限定されず、目的に応じて選択し得る。添加剤（ＨＲＯ）の分子量は、例えば３００００以下の範囲から選択し得る。また、添加剤（ＨＲＯ）は、ベースポリマーより低分子量の重合体または非重合体であることが好ましい。高屈折率化の効果と他の特性（例えば、粘着剤に適した柔軟性、ヘイズ等の光学特性）とをバランスよく両立する観点から、いくつかの態様において、添加剤（ＨＲＯ）の分子量は、凡そ１００００未満であることが適当であり、５０００未満であることが好ましく、３０００未満（例えば１０００未満）であることがより好ましく、８００未満でもよく、６００未満でもよく、５００未満でもよく、４００未満でもよい。添加剤（ＨＲＯ）の分子量が大きすぎないことは、粘着剤層内における相溶性向上の観点から有利となり得る。また、添加剤（ＨＲＯ）の分子量は、例えば１３０以上であってよく、１５０以上でもよい。いくつかの態様において、添加剤（ＨＲＯ）の分子量は、該添加剤（ＨＲＯ）の高屈折率化の観点から、１７０以上であることが好ましく、２００以上であることがより好ましく、２３０以上でもよく、２５０以上でもよく、２７０以上でもよく、５００以上でもよく、１０００以上でもよく、２０００以上でもよい。いくつかの態様において、分子量が１０００～１００００程度（例えば１０００以上５０００未満）の重合体を、添加剤（ＨＲＯ）として用いることができる。
　添加剤（ＨＲＯ）の分子量としては、非重合体または低重合度（例えば２～５量体程度）の重合体については、化学構造に基づいて算出される分子量、もしくはマトリックス支援レーザー脱離イオン化飛行時間型質量分析法（MALDI-TOF-MS）を用いた測定値を用いることができる。添加剤（ＨＲＯ）がより重合度の高い重合体である場合は、適切な条件で行われるＧＰＣに基づく重量平均分子量（Ｍｗ）を用いることができる。メーカー等から分子量の公称値が提供されている場合は、その公称値を採用することができる。 The molecular weight of the organic material used as an additive ( HRO ) is not particularly limited and can be selected according to the intended purpose. The molecular weight of the additive (H RO ) can be selected, for example, from the range of 30,000 or less. Further, the additive ( HRO ) is preferably a polymer or non-polymer having a lower molecular weight than the base polymer. In some embodiments, the molecular weight of the additive (HRO ) is balanced from the viewpoint of achieving a good balance between the effect of increasing the refractive index and other properties (for example, flexibility suitable for an adhesive and optical properties such as haze). Is more than about 10,000, preferably less than 5,000, more preferably less than 3,000 (eg, less than 1,000), less than 800, less than 600, less than 500, and more. It may be less than 400. It may be advantageous from the viewpoint of improving the compatibility in the pressure-sensitive adhesive layer that the molecular weight of the additive (H RO) is not too large. The molecular weight of the additive ( HRO ) may be, for example, 130 or more, or 150 or more. In some embodiments, the molecular weight of the additive (H RO), from the viewpoint of increasing the refractive index of the additive (H RO), preferably at least 170, more preferably 200 or more, 230 It may be 250 or more, 270 or more, 500 or more, 1000 or more, 2000 or more. In some embodiments, a polymer having a molecular weight of about 1000-10000 (eg, 1000 or more and less than 5000) can be used as the additive (HRO).
As for the molecular weight of the additive (HRO ), for a non-polymer or a polymer having a low degree of polymerization (for example, about 2 to 5 mer), the molecular weight is calculated based on the chemical structure, or matrix-assisted laser desorption / ionization. Measurements using time-of-flight mass spectrometry (MALDI-TOF-MS) can be used. When the additive (H RO ) is a polymer having a higher degree of polymerization, a weight average molecular weight (Mw) based on GPC performed under appropriate conditions can be used. If a manufacturer or the like provides a nominal value of molecular weight, that nominal value can be adopted.

　添加剤（ＨＲＯ）の選択肢となり得る有機材料の例には、芳香環を有する有機化合物、複素環（芳香環でもよく、非芳香族性の複素環でもよい。）を有する有機化合物、等が含まれるが、これらに限定されない。 Examples of organic materials that can be an additive ( HRO ) option include organic compounds having an aromatic ring, organic compounds having a heterocycle (which may be an aromatic ring or a non-aromatic heterocycle), and the like. Included, but not limited to.

　添加剤（ＨＲＯ）として用いられる上記芳香環を有する有機化合物（以下、「芳香環含有化合物」ともいう。）の有する芳香環は、モノマー（ｍ１）として用いられる化合物の有する芳香環と同様のものから選択され得る。 The aromatic ring of the organic compound having an aromatic ring used as an additive ( HRO ) (hereinafter, also referred to as “aromatic ring-containing compound”) is the same as that of the aromatic ring of the compound used as the monomer (m1). Can be selected from.

　上記芳香環は、環構成原子上に１または２以上の置換基を有していてもよく、置換基を有していなくてもよい。置換基を有する場合、該置換基としては、アルキル基、アルコキシ基、アリールオキシ基、水酸基、ハロゲン原子（フッ素原子、塩素原子、臭素原子等）、ヒドロキシアルキル基、ヒドロキシアルキルオキシ基、グリシジルオキシ基等が例示されるが、これらに限定されない。炭素原子を含む置換基において、該置換基に含まれる炭素原子の数は、例えば１～１０であり、有利には１～６であり、好ましくは１～４であり、より好ましくは１～３であり、例えば１または２であり得る。いくつかの態様において、上記芳香環は、環構成原子上に置換基を有しないか、アルキル基、アルコキシ基およびハロゲン原子（例えば臭素原子）からなる群から選択される１または２以上の置換基を有する芳香環であり得る。 The aromatic ring may have one or more substituents on the ring-constituting atom, and may not have a substituent. When it has a substituent, the substituent includes an alkyl group, an alkoxy group, an aryloxy group, a hydroxyl group, a halogen atom (fluorine atom, chlorine atom, bromine atom, etc.), a hydroxyalkyl group, a hydroxyalkyloxy group, and a glycidyloxy group. Etc., but are not limited thereto. Among the substituents containing carbon atoms, the number of carbon atoms contained in the substituent is, for example, 1 to 10, preferably 1 to 6, preferably 1 to 4, and more preferably 1 to 3. And can be, for example, 1 or 2. In some embodiments, the aromatic ring has one or more substituents that do not have a substituent on the ring-constituting atom or are selected from the group consisting of an alkyl group, an alkoxy group and a halogen atom (eg, a bromine atom). It can be an aromatic ring having.

　添加剤（ＨＲＯ）として用いられ得る芳香環含有化合物の例としては、例えば：モノマー（ｍ１）として用いられ得る化合物；モノマー（ｍ１）として用いられ得る化合物をモノマー単位として含むオリゴマー；モノマー（ｍ１）として用いられ得る化合物から、エチレン性不飽和基を有する基（環構成原子に結合した置換基であり得る。）または該基のうちエチレン性不飽和基を構成する部分を除き、水素原子またはエチレン性不飽和基を有しない基（例えば、水酸基、アミノ基、ハロゲン原子、アルキル基、アルコキシ基、ヒドロキシアルキル基、ヒドロキシアルキルオキシ基、グリシジルオキシ基等）に置き換えた構造の化合物；等が挙げられるが、これらに限定されない。添加剤（ＨＲＯ）として用いられ得る芳香環含有化合物の非限定的な具体例には、ベンジルアクリレート、ｍ－フェノキシベンジルアクリレート、２－（ｏ－フェニルフェノキシ）エチルアクリレート、フェノキシエチルアクリレート、フェノキシジエチレングリコールアクリレート、フェノキシポリエチレングリコールアクリレート、２－ヒドロキシ－３－フェノキシプロピルアクリレート、上述したフルオレン構造を有するモノマー、ジナフトチオフェン構造を有するモノマー、ジベンゾチオフェン構造を有するモノマー等の芳香環含有モノマー；３－フェノキシベンジルアルコール、ジナフトチオフェンおよびその誘導体（例えば、ジナフトチオフェン環に、ヒドロキシ基、メタノール基、ジエタノール基、グリシジル基等から選択される１種または２種以上の置換基が、１または２以上結合した構造の化合物）等の、エチレン性不飽和基を有しない芳香環含有化合物；等が含まれ得る。また、芳香環含有化合物は、このような芳香環含有モノマーをモノマー単位として含むオリゴマー（好ましくは分子量が凡そ５０００以下、より好ましくは凡そ１０００以下のオリゴマー。例えば２～５量体程度の低重合物）であり得る。上記オリゴマーは、例えば：芳香環含有モノマーの単独重合体；１種または２種以上の芳香環含有モノマーの共重合体；１種または２種以上の芳香環含有モノマーと他のモノマーとの共重合体；等であり得る。上記他のモノマーとしては、芳香環を有しないモノマーの１種または２種以上が用いられ得る。 Examples of the aromatic ring-containing compound which can be used as additives (H RO), for example: compounds may be used as the monomer (m1); oligomers containing a compound that may be used as the monomer (m1) as a monomer unit; monomer (m1 ), Except for a group having an ethylenically unsaturated group (which may be a substituent bonded to a ring-constituting atom) or a portion of the group constituting an ethylenically unsaturated group, a hydrogen atom or Compounds having a structure replaced with a group having no ethylenically unsaturated group (for example, a hydroxyl group, an amino group, a halogen atom, an alkyl group, an alkoxy group, a hydroxyalkyl group, a hydroxyalkyloxy group, a glycidyloxy group, etc.); However, it is not limited to these. Non-limiting examples of aromatic ring-containing compounds that can be used as additives ( HRO ) include benzyl acrylate, m-phenoxybenzyl acrylate, 2- (o-phenylphenoxy) ethyl acrylate, phenoxyethyl acrylate, phenoxydiethylene glycol. Aromatic ring-containing compounds such as acrylates, phenoxypolyethylene glycol acrylates, 2-hydroxy-3-phenoxypropyl acrylates, the above-mentioned monomers having a fluorene structure, monomers having a dinaphthophene structure, and monomers having a dibenzothiophene structure; 3-phenoxybenzyl Alcohol, dinaphthophene and derivatives thereof (for example, one or two or more substituents selected from a hydroxy group, a methanol group, a diethanol group, a glycidyl group and the like are bonded to the dinaphthophene ring. Aromatic ring-containing compounds that do not have ethylenically unsaturated groups, such as structural compounds); etc. may be included. The aromatic ring-containing compound is an oligomer containing such an aromatic ring-containing monomer as a monomer unit (preferably an oligomer having a molecular weight of about 5000 or less, more preferably about 1000 or less. For example, a low polymer of about 2 to pentameric. ) Can be. The oligomer is, for example: a homopolymer of an aromatic ring-containing monomer; a copolymer of one or more aromatic ring-containing monomers; a copolymer of one or two or more aromatic ring-containing monomers and another monomer. Coalescence; etc. As the other monomer, one kind or two or more kinds of monomers having no aromatic ring may be used.

　いくつかの態様において、添加剤（ＨＲＯ）としては、高い高屈折率化効果が得られやすいことから、１分子中に２以上の芳香環を有する有機化合物（以下、「芳香環複数含有化合物」ともいう。）を好ましく採用し得る。芳香環複数含有化合物は、エチレン性不飽和基等の重合性官能基を有していてもよく、有していなくてもよい。また、芳香環複数含有化合物は、重合体であってもよく、非重合体であってもよい。また、上記重合体は、芳香環複数含有モノマーをモノマー単位として含むオリゴマー（好ましくは分子量が凡そ５０００以下、より好ましくは凡そ１０００以下のオリゴマー。例えば２～５量体程度の低重合物）であり得る。上記オリゴマーは、例えば：芳香環複数含有モノマーの単独重合体；１種または２種以上の芳香環複数含有モノマーの共重合体；１種または２種以上の芳香環複数含有モノマーと他のモノマーとの共重合体；等であり得る。上記他のモノマーは、芳香環複数含有モノマーに該当しない芳香環含有モノマーでもよく、芳香環を有しないモノマーでもよく、これらの組合せであってもよい。 In some embodiments, the additive ( HRO ) is an organic compound having two or more aromatic rings in one molecule because a high refractive index increasing effect can be easily obtained (hereinafter, “a compound containing a plurality of aromatic rings”). ”) Can be preferably adopted. The compound containing a plurality of aromatic rings may or may not have a polymerizable functional group such as an ethylenically unsaturated group. Further, the compound containing a plurality of aromatic rings may be a polymer or a non-polymer. The polymer is an oligomer containing a monomer containing a plurality of aromatic rings as a monomer unit (preferably an oligomer having a molecular weight of about 5000 or less, more preferably about 1000 or less, for example, a low polymer of about 2 to pentamer). obtain. The above oligomers include, for example: a homopolymer of a plurality of aromatic ring-containing monomers; a copolymer of one or more kinds of multiple aromatic ring-containing monomers; and one or more kinds of multiple aromatic ring-containing monomers and other monomers. Copolymer; etc. The other monomer may be an aromatic ring-containing monomer that does not correspond to a monomer containing a plurality of aromatic rings, a monomer having no aromatic ring, or a combination thereof.

　芳香環複数含有化合物の非限定的な例としては、２以上の非縮合芳香環がリンキング基を介して結合した構造を有する化合物、２以上の非縮合芳香環が直接（すなわち、他の原子を介さずに）化学結合した構造を有する化合物、縮合芳香環構造を有する化合物、フルオレン構造を有する化合物、ジナフトチオフェン構造を有する化合物、ジベンゾチオフェン構造を有する化合物、等が挙げられる。芳香環複数含有化合物は、１種を単独でまたは２種以上を組み合せて用いることができる。 A non-limiting example of a compound containing a plurality of aromatic rings is a compound having a structure in which two or more non-condensed aromatic rings are bonded via a linking group, and two or more non-condensed aromatic rings directly (that is, other atoms). Examples thereof include a compound having a chemically bonded structure (without intervening), a compound having a condensed aromatic ring structure, a compound having a fluorene structure, a compound having a dinaphthophene structure, a compound having a dibenzothiophene structure, and the like. The compound containing a plurality of aromatic rings may be used alone or in combination of two or more.

　上記フルオレン構造を有する化合物の具体例としては、上述したフルオレン構造を有するモノマーや、かかるモノマーの単独重合体または共重合体であるオリゴマーのほか、９，９－ビス（４－ヒドロキシフェニル）フルオレン（屈折率：１．６８）、９，９－ビス（４－アミノフェニル）フルオレン（屈折率：１．７３）、９，９－ビス（４－ヒドロキシ－３－メチルフェニル）フルオレン（屈折率：１．６８）、９，９－ビス［４－（２－ヒドロキシエトキシ）フェニル］フルオレン（屈折率：１．６５）等の、９，９－ビスフェニルフルオレンおよびその誘導体が挙げられる。 Specific examples of the compound having a fluorene structure include the above-mentioned monomer having a fluorene structure, an oligomer which is a homopolymer or a copolymer of such a monomer, and 9,9-bis (4-hydroxyphenyl) fluorene ( Refraction rate: 1.68), 9,9-bis (4-aminophenyl) fluorene (refractive rate: 1.73), 9,9-bis (4-hydroxy-3-methylphenyl) fluorene (refractive rate: 1) .68), 9,9-bisphenylfluorene and its derivatives such as 9,9-bis [4- (2-hydroxyethoxy) phenyl] fluorene (refractive index: 1.65) can be mentioned.

　上記ジナフトチオフェン構造を有する化合物の具体例としては、上述したジナフトチオフェン構造を有するモノマーや、かかるモノマーの単独重合体または共重合体であるオリゴマーのほか、ジナフトチオフェン（屈折率：１．８０８）；６－ヒドロキシメチルジナフトチオフェン（屈折率：１．７６６）等のヒドロキシアルキルジナフトチオフェン；２，１２－ジヒドロキシジナフトチオフェン（屈折率：１．７５０）等のジヒドロキシジナフトチオフェン；２，１２－ジヒドロキエチルオキシジナフトチオフェン（屈折率：１．６７７）等のジヒドロキシアルキルオキシジナフトチオフェン；２，１２－ジグリシジルオキシジナフトチオフェン（屈折率１．７２３）等のジグリシジルオキシジナフトチオフェン；２，１２－ジアリルオキシジナフトチオフェン（略号：２，１２－ＤＡＯＤＮＴ、屈折率１．７２９）等の、エチレン性不飽和基を２以上有するジナフトチオフェン；等の、ジナフトチオフェンおよびその誘導体が挙げられる。 Specific examples of the compound having a dinaphthophene structure include the above-mentioned monomer having a dinaphthophene structure, an oligomer which is a homopolymer or a copolymer of such a monomer, and dinaphthophene (refractive index: 1. 808); hydroxyalkyl dinaphthophenes such as 6-hydroxymethyldinaphthophene (refractive index: 1.766); dihydroxydinaphthophenes such as 2,12-dihydroxydinaphthophene (refractive index: 1.750); 2 , 12-Dihydrochiethyloxydinaphthophene (refractive index: 1.677) and other dihydroxyalkyloxydinaphthophenes; Naftthiophene; dinaphthophene having two or more ethylenically unsaturated groups such as 2,12-dialyloxydinaphthophene (abbreviation: 2,12-DAODNT, refractive index 1.729); The derivative is mentioned.

　上記ジベンゾチオフェン構造を有する化合物の具体例としては、上述したジベンゾチオフェン構造を有するモノマーや、かかるモノマーの単独重合体または共重合体であるオリゴマーのほか、ジベンゾチオフェン（屈折率：１.６０７）、４－ジメチルジベンゾチオフェン（屈折率：１.６１７）、４，６－ジメチルジベンゾチオフェン（屈折率：１.６１７）、等が挙げられる。 Specific examples of the compound having the above-mentioned dibenzothiophene structure include the above-mentioned monomer having the dibenzothiophene structure, an oligomer which is a homopolymer or a copolymer of the above-mentioned monomer, and dibenzothiophene (refractive rate: 1.607). Examples thereof include 4-dimethyldibenzothiophene (refractive rate: 1.617), 4,6-dimethyldibenzothiophene (refractive rate: 1.617), and the like.

　添加剤（ＨＲＯ）の選択肢となり得る、複素環を有する有機化合物（以下、複素環含有有機化合物ともいう。）の例としては、チオエポキシ化合物、トリアジン環を有する化合物、等が挙げられる。チオエポキシ化合物の例としては、日本国特許第３７１２６５３号公報に記載のビス（２，３－エピチオプロピル）ジスルフィドおよびその重合物（屈折率１．７４）が挙げられる。トリアジン環を有する化合物の例としては、１分子内にトリアジン環を少なくとも１つ（例えば３～４０個、好ましくは５～２０個））有する化合物が挙げられる。なお、トリアジン環は芳香族性を有するため、トリアジン環を有する化合物は上記芳香環含有化合物の概念にも包含され、また、トリアジン環を複数有する化合物は上記芳香環複数含有化合物の概念にも包含される。 It can be the choice of the additives (H RO), an organic compound having a heterocyclic ring (hereinafter, heterocyclic also called containing organic compound.) Examples of thioepoxy compound, a compound having a triazine ring, and the like. Examples of the thioepoxy compound include bis (2,3-epithiopropyl) disulfide described in Japanese Patent No. 3712653 and a polymer thereof (refractive index 1.74). Examples of the compound having a triazine ring include a compound having at least one triazine ring (for example, 3 to 40, preferably 5 to 20) in one molecule. Since the triazine ring has aromaticity, the compound having a triazine ring is also included in the concept of the above-mentioned aromatic ring-containing compound, and the compound having a plurality of triazine rings is also included in the concept of the above-mentioned compound containing a plurality of aromatic rings. Will be done.

　いくつかの態様において、添加剤（ＨＲＯ）としては、エチレン性不飽和基を有しない化合物を好ましく採用し得る。これにより、熱や光による粘着剤組成物の変質（ゲル化の進行や粘度上昇によるレベリング性の低下）を抑制し、保存安定性を高めることができる。エチレン性不飽和基を有しない添加剤（ＨＲＯ）を採用することは、該添加剤（ＨＲＯ）を含む粘着剤層を有する粘着シートや、該粘着シートを含む積層体等において、エチレン性不飽和基の反応に起因する寸法変化や変形（反り、波打ち等）、光学歪の発生等を抑制する観点からも好ましい。 In some embodiments, the additive ( HRO ) may preferably be a compound that does not have an ethylenically unsaturated group. As a result, deterioration of the pressure-sensitive adhesive composition due to heat or light (decrease in leveling property due to progress of gelation or increase in viscosity) can be suppressed, and storage stability can be improved. Adopting an additive (H RO ) that does not have an ethylenically unsaturated group means that the pressure-sensitive adhesive sheet having the pressure-sensitive adhesive layer containing the additive (H RO ), the laminate containing the pressure-sensitive adhesive sheet, and the like are ethylenic. It is also preferable from the viewpoint of suppressing dimensional changes and deformations (warping, waviness, etc.) and occurrence of optical strain caused by the reaction of unsaturated groups.

　添加剤（ＨＲＯ）としてオリゴマーを使用する態様において、該オリゴマーは、対応するモノマー成分を公知の方法で重合させることにより得ることができる。上記オリゴマーをラジカル重合により製造する場合には、上記モノマー成分に、ラジカル重合に用いられる重合開始剤、連鎖移動剤、乳化剤等を適宜添加して 、重合を行うことができる。上記ラジカル重合に用いられる重合開始剤、連鎖移動剤、乳 化剤等は、特に限定されず、適宜選択して使用することができる。なお、オリゴマーの重量平均分子量は、重合開始剤、連鎖移動剤の使用量、反応条件により制御可能であり、これらの種類に応じて適宜その使用量が調整される。
　上記連鎖移動剤としては、例えば、ラウリルメルカプタン、グリシジルメルカプタン、メルカプト酢酸、２－メルカプトエタノール、α－チオグリセロール、チオグリコール酸、チオグルコール酸２－エチルヘキシル、２，３－ジメルカプト－１－プロパノール等が挙げられる。連鎖移動剤は、１種を単独で使用してもよく、２種以上を混合して使用してもよい。連鎖移動剤の使用量は、オリゴマーの合成に用いられるモノマー成分の組成や連鎖移動剤の種類等に応じて、所望の重量平均分子量のオリゴマーが得られるように設定することができる。いくつかの態様において、オリゴマーの合成に用いられるモノマーの全量１００重量部に対する連鎖移動剤の使用量は、凡そ１５重量部以下とすることが適当であり、１０重量部以下でもよく、５重量部程度以下でもよい。オリゴマーの合成に用いられるモノマーの全量１００重量部に対する連鎖移動剤の使用量の下限は特に制限されないが、例えば０．０１重量部以上であってよく、０．１重量部以上でもよく、０．５重量部以上でもよく、１重量部以上でもよい。 In an embodiment in which an oligomer is used as an additive ( HRO ), the oligomer can be obtained by polymerizing the corresponding monomer component in a known manner. When the above-mentioned oligomer is produced by radical polymerization, polymerization can be carried out by appropriately adding a polymerization initiator, a chain transfer agent, an emulsifier and the like used for radical polymerization to the above-mentioned monomer component. The polymerization initiator, chain transfer agent, emulsifying agent and the like used in the above radical polymerization are not particularly limited and can be appropriately selected and used. The weight average molecular weight of the oligomer can be controlled by the amount of the polymerization initiator and the chain transfer agent used, and the reaction conditions, and the amount used is appropriately adjusted according to these types.
Examples of the chain transfer agent include lauryl mercaptan, glycidyl mercaptan, mercaptoacetic acid, 2-mercaptoethanol, α-thioglycerol, thioglycolic acid, 2-ethylhexyl thioglycolate, 2,3-dimercapto-1-propanol and the like. Be done. The chain transfer agent may be used alone or in combination of two or more. The amount of the chain transfer agent used can be set so that an oligomer having a desired weight average molecular weight can be obtained according to the composition of the monomer component used for the synthesis of the oligomer, the type of the chain transfer agent, and the like. In some embodiments, the amount of the chain transfer agent used with respect to 100 parts by weight of the total amount of the monomers used in the synthesis of the oligomer is preferably about 15 parts by weight or less, and may be 10 parts by weight or less, and 5 parts by weight. It may be less than or equal to the degree. The lower limit of the amount of the chain transfer agent used with respect to 100 parts by weight of the total amount of the monomers used for the synthesis of the oligomer is not particularly limited, but may be, for example, 0.01 parts by weight or more, 0.1 parts by weight or more, and 0. It may be 5 parts by weight or more, or 1 part by weight or more.

　屈折率向上剤として添加剤（ＨＲＯ）を使用する態様において、ベースポリマー１００重量部に対する添加剤（ＨＲＯ）の使用量（複数種の化合物を用いる場合は、それらの合計量）は、特に限定されず、目的に応じて設定することができる。粘着剤の高屈折率化の観点から、ベースポリマー１００重量部に対する添加剤（ＨＲＯ）の使用量は、例えば１重量部以上とすることができ、３重量部以上とすることが有利であり、５重量部以上とすることが好ましく、７重量部以上でもよく、１０重量部以上でもよく、１５重量部以上でもよく、２０重量部以上でもよい。いくつかの態様において、ベースポリマー１００重量部に対する添加剤（ＨＲＯ）の使用量は、例えば８０重量部以下とすることができ、粘着剤の高屈折率化と粘着特性や光学特性の低下抑制とをバランスよく両立する観点から、６０重量部以下とすることが有利であり、４５重量部以下とすることが好ましい。より粘着特性や光学特性を重視するいくつかの態様において、ベースポリマー１００重量部に対する添加剤（ＨＲＯ）の使用量は、例えば３０重量部以下であってよく、２０重量部以下でもよく、１５重量部以下でもよく、１０重量部以下でもよい。 In embodiments using an additive (H RO) as a refractive index enhancing agent, the amount of additive to 100 parts by weight of the base polymer (H RO) (in the case of using a plurality of compounds, their total amount), particularly It is not limited and can be set according to the purpose. From the viewpoint of increasing the refractive index of the pressure-sensitive adhesive, the amount of the additive ( HRO ) used with respect to 100 parts by weight of the base polymer can be, for example, 1 part by weight or more, and it is advantageous to use 3 parts by weight or more. It is preferably 5 parts by weight or more, 7 parts by weight or more, 10 parts by weight or more, 15 parts by weight or more, or 20 parts by weight or more. In some embodiments, the amount of the additive (HRO ) used with respect to 100 parts by weight of the base polymer can be, for example, 80 parts by weight or less, so that the refractive index of the pressure-sensitive adhesive is increased and the deterioration of the pressure-sensitive adhesive properties and the optical properties is suppressed. From the viewpoint of achieving a good balance between the above and the like, it is advantageous to use 60 parts by weight or less, and preferably 45 parts by weight or less. In some embodiments where more adhesive properties and optical properties are emphasized, the amount of the additive (HRO ) used per 100 parts by weight of the base polymer may be, for example, 30 parts by weight or less, 20 parts by weight or less, and 15 parts by weight. It may be 10 parts by weight or less.

　（可塑化材料）
　ここに開示される層間シートのいくつかの態様において、粘着剤層Ｖ１は、上述のようなベースポリマー（例えば、アクリル系ポリマー（Ａ））に加えて、該ベースポリマーより低分子量の可塑化材料を含み得る。可塑化材料の使用により、粘着剤層Ｖ１の柔軟性を高め、被着体に対する密着性や、層間シート全体としての柔軟性や変形に対する追従性を向上させ得る。可塑化材料としては、粘着剤層内における相溶性や透明性の観点から、有機材料を好ましく採用し得る。可塑化材料は、上述した屈折率向上剤（例えば、上記添加剤（ＨＲＯ））としても用いられ得る材料であってもよい。 (Therplastic material)
In some embodiments of the interlayer sheet disclosed herein, the pressure-sensitive adhesive layer V 1 was a base polymer as described above (e.g., the acrylic polymer (A)) in addition to the plasticizing low molecular weight than the base polymer May include material. The use of plasticized material, increase the flexibility of the adhesive layer V 1, and the adhesion to the adherend, can improve followability to the flexibility or deformation of the entire interlayer sheet. As the plasticizing material, an organic material can be preferably adopted from the viewpoint of compatibility and transparency in the pressure-sensitive adhesive layer. The thermoplastic material may be a material that can also be used as the above-mentioned refractive index improver (for example, the above-mentioned additive ( HRO)).

　可塑化材料の分子量は、ベースポリマーより低ければよく、特に限定されない。いくつかの態様において、可塑化材料の分子量は、可塑化効果を発現しやすくする観点から、３００００以下でもよく、２５０００以下でもよく、１００００未満でもよく、５０００未満であることが好ましく、３０００未満（例えば１０００未満）であることがより好ましく、８００未満でもよく、６００未満でもよく、５００未満でもよく、４００未満でもよい。可塑化材料の分子量が大きすぎないことは、粘着剤層内における相溶性向上等の観点から有利となり得る。また、いくつかの態様において、可塑化材料の分子量は、十分な可塑化効果を発揮しやすくする観点から、１３０以上であることが適当であり、１５０以上であることが好ましく、１７０以上でもよく、２００以上でもよく、２５０以上でもよく、３００以上でもよい。いくつかの態様において、可塑化材料の分子量は、５００以上であってもよく、１０００以上であってもよく、２０００以上であってもよい。可塑化材料の分子量が低すぎないことは、層間シートの耐熱性能や被着体の汚染抑制の観点からも好ましい。 The molecular weight of the plasticizing material may be lower than that of the base polymer, and is not particularly limited. In some embodiments, the molecular weight of the plasticizing material may be 30,000 or less, 25,000 or less, less than 10,000, preferably less than 5,000, and less than 3,000 (preferably less than 3,000, from the viewpoint of facilitating the development of the plasticizing effect. For example, less than 1000) is more preferable, and it may be less than 800, less than 600, less than 500, or less than 400. The fact that the molecular weight of the plasticized material is not too large can be advantageous from the viewpoint of improving compatibility in the pressure-sensitive adhesive layer. Further, in some embodiments, the molecular weight of the plasticizing material is preferably 130 or more, preferably 150 or more, and may be 170 or more, from the viewpoint of facilitating the exertion of a sufficient plasticizing effect. , 200 or more, 250 or more, 300 or more. In some embodiments, the molecular weight of the thermoplastic material may be 500 or greater, 1000 or greater, or 2000 or greater. It is preferable that the molecular weight of the thermoplastic material is not too low from the viewpoint of the heat resistance performance of the interlayer sheet and the suppression of contamination of the adherend.

　可塑化材料の選択肢となり得る化合物の非限定的な例には、モノマー（ｍ１）として用いられ得る化合物（例えば、ベンジル基、フェノキシ基、ナフチル基等の芳香環を有する（メタ）アクリレート、フルオレン構造を有するモノマー、ジナフトチオフェン構造を有するモノマー、ジベンゾチオフェン構造を有するモノマー等）；モノマー（ｍ１）として用いられ得る化合物をモノマー単位として含むオリゴマー；モノマー（ｍ１）として用いられ得る化合物から、エチレン性不飽和基を有する部分を除き、水素原子またはエチレン性不飽和基を有しない基に置き換えた構造の化合物（例えば、３－フェノキシベンジルアルコール）；等が含まれる。モノマー（ｍ１）として用いられ得る化合物をモノマー単位として含むオリゴマーには、柔軟性向上の観点から、例えばｎ－ブチルアクリレートや２－エチルヘキシルアクリレート等の低Ｔｇモノマーが共重合されていてもよい。可塑化材料として、公知の可塑剤（例えば、フタル酸エステル系、テレフタル酸エステル系、アジピン酸エステル系、アジピン酸系ポリエステル、安息香酸グリコールエステル等）の１種または２種以上を利用してもよい。 Non-limiting examples of compounds that can be options for plasticizing materials include compounds that can be used as monomers (m1) (eg, (meth) acrylates having aromatic rings such as benzyl group, phenoxy group, naphthyl group, fluorene structure. Monomer having, dinaphthophene structure, monomer having dibenzothiophene structure, etc.); Monomer containing a compound that can be used as a monomer (m1) as a monomer unit; Ethylene property from a compound that can be used as a monomer (m1) A compound having a structure in which a hydrogen atom or a group having no ethylenically unsaturated group is replaced except for a portion having an unsaturated group (for example, 3-phenoxybenzyl alcohol); and the like are included. From the viewpoint of improving flexibility, a low Tg monomer such as n-butyl acrylate or 2-ethylhexyl acrylate may be copolymerized with the oligomer containing a compound that can be used as the monomer (m1) as a monomer unit. As the plasticizing material, one or more known plasticizers (for example, phthalate ester, terephthalic acid ester, adipate ester, adipate polyester, benzoic acid glycol ester, etc.) may be used. good.

　いくつかの態様において、可塑化材料としては、屈折率が凡そ１．５０以上（より好ましくは１．５３以上）の有機材料が好ましく用いられ得る。可塑化材料の選択肢となり得る化合物の具体例には、ジエチレングリコールジベンゾエート（屈折率１．５５）、ジプロピレングリコールジベンゾエート（屈折率１．５４）、３－フェノキシトルエン（屈折率１．５７）、３－エチルビフェニル（屈折率１．５９）、３－メトキシビフェニル（屈折率１．６１）、４－メトキシビフェニル（屈折率１．５７）、ポリエチレングリコールジベンゾエート、３－フェノキシベンジルアルコール（屈折率１．５９）、トリフェニルホスフェート（屈折率１．５６）、安息香酸ベンジル（屈折率１．５７）、４－（ｔｅｒｔ－ブチル）フェニルジフェニルホスフェート（屈折率１．５６）、トリメチルフェニルホスフェート（屈折率１．５５）、ブチルベンジルフタレート（屈折率１．５４）、ロジンメチルエステル（屈折率１．５３）、アルキルベンジルフタレート（屈折率１．５３）、ブチル（フェニルスルホニル）アミン（屈折率１．５３）、トリメチルトリメリテート（屈折率１．５２）、ベンジルフタレート（屈折率１．５２）、２－エチルヘキシルジフェニルホスフェート（屈折率１．５１）、亜りん酸トリス（２，４－ジ－ｔｅｒｔ－ブチルフェニル）、等が含まれるが、これらに限定されない。屈折率および相溶性の観点から、例えばジエチレングリコールジベンゾエートを好ましく採用し得る。可塑化材料の屈折率の上限は、特に制限されず、例えば３．００以下であり得る。いくつかの態様において、粘着剤組成物の調製容易性や、粘着剤内における相溶性等の観点から、可塑化材料の屈折率は、２．５０以下であることが適当であり、２．００以下であることが有利であり、１．９０以下でもよく、１．８０以下でもよく、１．７０以下でもよい。
　なお、可塑化材料の屈折率は、モノマーの屈折率と同様に、アッベ屈折率計を用いて、測定波長５８９ｎｍ、測定温度２５℃の条件で測定される。メーカー等から２５℃における屈折率の公称値が提供されている場合は、その公称値を採用することができる。 In some embodiments, as the thermoplastic material, an organic material having a refractive index of about 1.50 or more (more preferably 1.53 or more) can be preferably used. Specific examples of compounds that can be options for plasticizing materials include diethylene glycol dibenzoate (refraction: 1.55), dipropylene glycol dibenzoate (refraction: 1.54), 3-phenoxytoluene (refraction: 1.57), 3-Ethylbiphenyl (refraction 1.59), 3-methoxybiphenyl (refraction 1.61), 4-methoxybiphenyl (refraction 1.57), polyethylene glycol dibenzoate, 3-phenoxybenzyl alcohol (refraction 1) .59), triphenyl phosphate (refraction rate 1.56), benzyl benzoate (refraction rate 1.57), 4- (tert-butyl) phenyldiphenyl phosphate (refraction rate 1.56), trimethylphenyl phosphate (refraction rate 1.56) 1.55), butylbenzylphthalate (refraction 1.54), rosinmethyl ester (refraction 1.53), alkylbenzylphthalate (refraction 1.53), butyl (phenylsulfonyl) amine (refraction 1.53) ), Trimethyltrimeritate (refraction: 1.52), benzylphthalate (refraction: 1.52), 2-ethylhexyldiphenyl phosphate (refraction: 1.51), tris phosphite (2,4-di-tert-) Butylphenyl), etc., but not limited to these. From the viewpoint of refractive index and compatibility, for example, diethylene glycol dibenzoate can be preferably adopted. The upper limit of the refractive index of the plasticized material is not particularly limited and may be, for example, 3.00 or less. In some embodiments, the refractive index of the thermoplastic material is preferably 2.50 or less, 2.00, from the viewpoint of ease of preparation of the pressure-sensitive adhesive composition, compatibility in the pressure-sensitive adhesive, and the like. It is advantageous that it is 1.90 or less, 1.80 or less, or 1.70 or less.
The refractive index of the plasticized material is measured using an Abbe refractive index meter under the conditions of a measurement wavelength of 589 nm and a measurement temperature of 25 ° C., similarly to the refractive index of the monomer. If the manufacturer or the like provides a nominal value of the refractive index at 25 ° C., the nominal value can be adopted.

　可塑化材料を使用する態様において、ベースポリマー１００重量部に対する可塑化材料の使用量は、特に限定されず、目的に応じて設定することができる。可塑化効果を高める観点から、ベースポリマー１００重量部に対する可塑化材料の使用量は、例えば０．１重量部以上であってよく、０．５重量部以上であってもよく、より高い可塑化効果を得る観点から１重量部以上とすることが好ましく、３重量部以上とすることがより好ましく、５重量部以上でもよく、７重量部以上でもよく、１０重量部以上でもよく、１５重量部以上でもよく、２０重量部以上でもよい。また、粘着剤の高屈折率化と透明性および可塑化効果とをバランスよく両立する観点から、ベースポリマー１００重量部に対する可塑化材料の使用量は、凡そ１００重量部以下とすることが適当であり、８０重量部以下とすることが好ましく、６０重量部以下とすることがより好ましく、４５重量部以下でもよく、３５重量部以下でもよく、２５重量部以下でもよい。より粘着特性や光学特性を重視するいくつかの態様において、ベースポリマー１００重量部に対する可塑化材料の使用量は、１５重量部以下でもよく、１０重量部以下でもよく、５重量部以下でもよい。 In the embodiment in which the plasticized material is used, the amount of the plasticized material used with respect to 100 parts by weight of the base polymer is not particularly limited and can be set according to the purpose. From the viewpoint of enhancing the plasticizing effect, the amount of the plasticizing material used with respect to 100 parts by weight of the base polymer may be, for example, 0.1 part by weight or more, 0.5 parts by weight or more, and higher plasticization. From the viewpoint of obtaining the effect, it is preferably 1 part by weight or more, more preferably 3 parts by weight or more, 5 parts by weight or more, 7 parts by weight or more, 10 parts by weight or more, and 15 parts by weight. It may be more than 20 parts by weight. Further, from the viewpoint of achieving a good balance between high refractive index of the pressure-sensitive adhesive, transparency and plasticizing effect, it is appropriate that the amount of the plasticizing material used with respect to 100 parts by weight of the base polymer is about 100 parts by weight or less. It is preferably 80 parts by weight or less, more preferably 60 parts by weight or less, 45 parts by weight or less, 35 parts by weight or less, or 25 parts by weight or less. In some embodiments where more adhesive properties and optical properties are emphasized, the amount of the thermoplastic material used with respect to 100 parts by weight of the base polymer may be 15 parts by weight or less, 10 parts by weight or less, or 5 parts by weight or less.

　（レベリング剤）
　いくつかの態様において、粘着剤層（粘弾性層Ｖ１および／または粘弾性層Ｖ２であり得る。）の形成に用いられる粘着剤組成物には、該組成物から形成される粘着剤層の外観向上（例えば、厚みの均一性の向上）や上記粘着剤組成物の塗工性向上等の目的で、必要に応じてレベリング剤を含有させることができる。レベリング剤の非限定的な例としては、アクリル系レベリング剤、フッ素系レベリング剤、シリコーン系レベリング剤などが挙げられる。レベリング剤は、例えば、市販のレベリング剤から適切なものを選択し、常法により用いることができる。 (Leveling agent)
In some embodiments, (which may be a viscoelastic layer V 1 and / or viscoelastic layer V 2.) Adhesive layer on the pressure-sensitive adhesive composition used for forming a pressure-sensitive adhesive layer formed from the composition A leveling agent can be contained as necessary for the purpose of improving the appearance (for example, improving the uniformity of thickness) and improving the coatability of the pressure-sensitive adhesive composition. Non-limiting examples of the leveling agent include an acrylic leveling agent, a fluorine-based leveling agent, a silicone-based leveling agent, and the like. As the leveling agent, for example, an appropriate leveling agent can be selected from commercially available leveling agents and used by a conventional method.

　いくつかの態様において、上記レベリング剤として、ポリオルガノシロキサン骨格を有するモノマー（以下、「モノマーＳ１」ともいう。）とアクリル系モノマーとを含むモノマー原料（以下、「モノマー原料Ｂ」ともいう。）の重合物であるポリマー（以下、「ポリマー（Ｂ）」ともいう。）を好ましく用いることができる。ポリマー（Ｂ）は、モノマーＳ１とアクリル系モノマーとの共重合体ということができる。ポリマー（Ｂ）は、一種を単独でまたは二種以上を組み合わせて使用することができる。 In some embodiments, as the leveling agent, a monomer raw material containing a monomer having a polyorganosiloxane skeleton (hereinafter, also referred to as “monomer S1”) and an acrylic monomer (hereinafter, also referred to as “monomer raw material B”). A polymer (hereinafter, also referred to as “polymer (B)”) which is a polymer of the above can be preferably used. The polymer (B) can be said to be a copolymer of the monomer S1 and the acrylic monomer. The polymer (B) can be used alone or in combination of two or more.

　モノマーＳ１としては、特に限定されず、ポリオルガノシロキサン骨格を含有する任意のモノマーを用いることができる。モノマーＳ１としては、片末端に重合性反応基を有する構造のものを好ましく用いることができる。なかでも、片末端に重合性反応基を有し、かつ、他の末端にベースポリマー（該レベリング剤が配合される粘着剤組成物のベースポリマーを指す。例えばアクリル系ポリマー）と架橋反応を生じる官能基を有しない構造のモノマーＳ１を好ましく採用し得る。市販品としては、例えば、信越化学工業社製の片末端反応性シリコーンオイル（例えば、Ｘ－２２－１７４ＡＳＸ、Ｘ－２２－２４２６、Ｘ－２２－２４７５、ＫＦ－２０１２等の品番）が挙げられる。モノマーＳ１は、一種を単独でまたは二種以上を組み合わせて使用することができる。 The monomer S1 is not particularly limited, and any monomer containing a polyorganosiloxane skeleton can be used. As the monomer S1, a monomer having a structure having a polymerizable reactive group at one end can be preferably used. Among them, it has a polymerizable reactive group at one end and causes a cross-linking reaction with a base polymer (refers to a base polymer of a pressure-sensitive adhesive composition containing the leveling agent, for example, an acrylic polymer) at the other end. A monomer S1 having a structure having no functional group can be preferably adopted. Examples of commercially available products include one-ended reactive silicone oils manufactured by Shin-Etsu Chemical Co., Ltd. (for example, product numbers of X-22-174ASX, X-22-2426, X-22-2475, KF-2012, etc.). .. Monomer S1 can be used alone or in combination of two or more.

　モノマーＳ１の官能基当量は、例えば１００ｇ／ｍｏｌ～３００００ｇ／ｍｏｌ程度であり得る。いくつかの好ましい態様では、上記官能基当量は、例えば５００ｇ／ｍｏｌ以上であり、８００ｇ／ｍｏｌ以上でもよく、１５００ｇ／ｍｏｌ以上でもよく、２０００ｇ／ｍｏｌ以上でもよい。また、上記官能基当量は、例えば２００００ｇ／ｍｏｌ以下であってよく、１００００ｇ／ｍｏｌ未満でもよく、７０００ｇ／ｍｏｌ以下でもよく、５５００ｇ／ｍｏｌ以下でもよい。モノマーＳ１の官能基当量が上記範囲内であると、良好なレベリング効果が発揮されやすい。
　なお、モノマーＳ１として官能基当量が異なる二種類以上のモノマーを用いる場合、モノマーＳ１の官能基当量とは、各種類のモノマーの官能基当量と該モノマーの重量分率との積の総和を用いることができる。 The functional group equivalent of the monomer S1 can be, for example, about 100 g / mol to 30,000 g / mol. In some preferred embodiments, the functional group equivalent may be, for example, 500 g / mol or more, 800 g / mol or more, 1500 g / mol or more, or 2000 g / mol or more. The functional group equivalent may be, for example, 20000 g / mol or less, less than 10000 g / mol, 7000 g / mol or less, or 5500 g / mol or less. When the functional group equivalent of the monomer S1 is within the above range, a good leveling effect is likely to be exhibited.
When two or more types of monomers having different functional group equivalents are used as the monomer S1, the functional group equivalent of the monomer S1 is the sum of the products of the functional group equivalents of each type of monomer and the weight fraction of the monomer. be able to.

　ここで、「官能基当量」とは、官能基１個当たりに結合している主骨格（例えばポリジメチルシロキサン）の重量を意味する。標記単位ｇ／ｍｏｌに関しては、官能基１ｍｏｌと換算している。モノマーＳ１の官能基当量は、例えば、核磁気共鳴（ＮＭＲ）に基づく１Ｈ－ＮＭＲ（プロトンＮＭＲ）のスペクトル強度から算出することができる。１Ｈ－ＮＭＲのスペクトル強度に基づくモノマーＳ１の官能基当量（ｇ／ｍｏｌ）の算出は、１Ｈ－ＮＭＲスペクトル解析に係る一般的な構造解析手法に基づいて、必要であれば日本国特許第５９５１１５３号公報の記載を参照して行うことができる。モノマーＳ１の官能基当量において、上記官能基とは、重合性官能基（例えば、（メタ）アクリロイル基、ビニル基、アリル基等のエチレン性不飽和基）を意味する。 Here, the "functional group equivalent" means the weight of the main skeleton (for example, polydimethylsiloxane) bonded to each functional group. The title unit g / mol is converted to 1 mol of functional group. The functional group equivalent of the monomer S1 can be calculated, for example, from the spectral intensity of 1 H-NMR (proton NMR) based on nuclear magnetic resonance (NMR). 1 The calculation of the functional group equivalent (g / mol) of the monomer S1 based on the spectral intensity of 1 H-NMR is based on the general structural analysis method related to 1 1 H-NMR spectrum analysis, and if necessary, the Japanese Patent No. 1 This can be done with reference to the description in Publication No. 5591153. In terms of the functional group equivalent of the monomer S1, the functional group means a polymerizable functional group (for example, an ethylenically unsaturated group such as a (meth) acryloyl group, a vinyl group or an allyl group).

　モノマー原料ＢにおけるモノマーＳ１の含有量は、該モノマーＳ１を用いて所望の効果が発揮される範囲で適切な値を採用することができ、特定の範囲に限定されない。いくつかの態様において、モノマー原料ＢにおけるモノマーＳ１の含有量は、例えば５～６０重量％であってよく、１０～５０重量％でもよく、１５～４０重量％でもよい。 The content of the monomer S1 in the monomer raw material B can be an appropriate value within a range in which the desired effect is exhibited by using the monomer S1, and is not limited to a specific range. In some embodiments, the content of the monomer S1 in the monomer raw material B may be, for example, 5-60% by weight, 10-50% by weight, or 15-40% by weight.

　モノマー原料Ｂは、モノマーＳ１に加えて、モノマーＳ１と共重合可能なアクリル系モノマーを含む。これにより、粘着剤層内におけるポリマー（Ｂ）の相溶性を改善し得る。モノマー原料Ｂに使用し得るアクリル系モノマーとしては、例えば、アクリル酸アルキルエステルが挙げられる。ここでいう「アルキル」は、鎖状（直鎖状、分岐鎖状を包含する。）のアルキル（基）をいい、後述の脂環式炭化水素基を含まない。いくつかの態様において、モノマー原料Ｂは、（メタ）アクリル酸Ｃ４－１２アルキルエステル（好ましくは（メタ）アクリル酸Ｃ４－１０アルキルエステル、例えば（メタ）アクリル酸Ｃ６－１０アルキルエステル）の少なくとも一種を含有し得る。他のいくつかの態様において、モノマー原料Ｂは、メタクリル酸Ｃ１－１８アルキルエステル（好ましくはメタクリル酸Ｃ１－１４アルキルエステル、例えばメタクリル酸Ｃ１－１０アルキルエステル）の少なくとも一種を含有し得る。モノマー原料Ｂは、アクリル系モノマーとして、例えば、メタクリル酸メチル（ＭＭＡ）、メタクリル酸ｎ－ブチル（ＢＭＡ）およびメタクリル酸２－エチルヘキシル（２ＥＨＭＡ）から選択される一種または二種以上を含み得る。 The monomer raw material B contains an acrylic monomer copolymerizable with the monomer S1 in addition to the monomer S1. Thereby, the compatibility of the polymer (B) in the pressure-sensitive adhesive layer can be improved. Examples of the acrylic monomer that can be used for the monomer raw material B include acrylic acid alkyl esters. The term "alkyl" as used herein refers to a chain-like (including linear and branched-chain) alkyl (groups), and does not include the alicyclic hydrocarbon group described later. In some embodiments, the monomer raw material B is a (meth) acrylic acid C 4-12 alkyl ester (preferably a (meth) acrylic acid C 4-10 alkyl ester, eg, a (meth) acrylic acid C 6-10 alkyl ester). Can contain at least one of. In some other embodiments, the monomer raw material B may contain at least one of a methacrylic acid C 1-18 alkyl ester (preferably a methacrylic acid C 1-14 alkyl ester, such as a methacrylic acid C 1-10 alkyl ester). .. The monomer raw material B may contain, for example, one or more selected from methyl methacrylate (MMA), n-butyl methacrylate (BMA) and 2-ethylhexyl methacrylate (2EHMA) as the acrylic monomer.

　上記アクリル系モノマーの他の例として、脂環式炭化水素基を有する（メタ）アクリル酸エステルが挙げられる。例えば、シクロペンチル（メタ）アクリレート、シクロヘキシル（メタ）アクリレート、イソボルニル（メタ）アクリレート、ジシクロペンタニル（メタ）アクリレート、１－アダマンチル（メタ）アクリレート等を用いることができる。脂環式炭化水素基を有する（メタ）アクリル酸エステルを使用しなくてもよい。 Another example of the above acrylic monomer is a (meth) acrylic acid ester having an alicyclic hydrocarbon group. For example, cyclopentyl (meth) acrylate, cyclohexyl (meth) acrylate, isobornyl (meth) acrylate, dicyclopentanyl (meth) acrylate, 1-adamantyl (meth) acrylate and the like can be used. It is not necessary to use a (meth) acrylic acid ester having an alicyclic hydrocarbon group.

　モノマー原料Ｂにおける上記（メタ）アクリル酸アルキルエステルおよび上記脂環式炭化水素基を有する（メタ）アクリル酸エステルの含有量は、例えば１０重量％以上９５重量％以下であってよく、２０重量％以上９５重量％以下であってもよく、３０重量％以上９０重量％以下であってもよく、４０重量％以上９０重量％以下であってもよく、５０重量％以上８５重量％以下であってもよい。 The content of the (meth) acrylic acid alkyl ester and the (meth) acrylic acid ester having an alicyclic hydrocarbon group in the monomer raw material B may be, for example, 10% by weight or more and 95% by weight or less, and 20% by weight. It may be 95% by weight or less, 30% by weight or more and 90% by weight or less, 40% by weight or more and 90% by weight or less, and 50% by weight or more and 85% by weight or less. May be good.

　モノマーＳ１とともにモノマー原料Ｂに含まれ得るモノマーの他の例として、アクリル系ポリマーに用いられ得るモノマーとして上記で例示したカルボキシ基含有モノマー、酸無水物基含有モノマー、水酸基含有モノマー、エポキシ基含有モノマー、シアノ基含有モノマー、イソシアネート基含有モノマー、アミド基含有モノマー、窒素原子含有環を有するモノマー、（メタ）アクリル酸アミノアルキル類、ビニルエステル類、ビニルエーテル類、オレフィン類、芳香族炭化水素基を有する（メタ）アクリル酸エステル、ハロゲン原子含有（メタ）アクリレート等が挙げられる。 As another example of the monomer that can be contained in the monomer raw material B together with the monomer S1, the carboxy group-containing monomer, the acid anhydride group-containing monomer, the hydroxyl group-containing monomer, and the epoxy group-containing monomer exemplified above as the monomers that can be used for the acrylic polymer. , Cyano group-containing monomer, isocyanate group-containing monomer, amide group-containing monomer, monomer having nitrogen atom-containing ring, aminoalkyl (meth) acrylate, vinyl esters, vinyl ethers, olefins, aromatic hydrocarbon group Examples thereof include (meth) acrylic acid ester and halogen atom-containing (meth) acrylate.

　ポリマー（Ｂ）のＭｗは、例えば５，０００以上であってよく、１０，０００以上であることが好ましく、１５，０００以上でもよい。また、ポリマー（Ｂ）のＭｗは、例えば２００，０００以下であってよく、１００，０００以下であることが好ましく、５０，０００以下でもよく、３０，０００以下でもよい。ポリマー（Ｂ）のＭｗを適当な範囲に設定することにより、好適な相溶性およびレベリング性が発揮され得る。 The Mw of the polymer (B) may be, for example, 5,000 or more, preferably 10,000 or more, and may be 15,000 or more. The Mw of the polymer (B) may be, for example, 200,000 or less, preferably 100,000 or less, 50,000 or less, or 30,000 or less. By setting the Mw of the polymer (B) in an appropriate range, suitable compatibility and leveling properties can be exhibited.

　ポリマー（Ｂ）は、例えば、上述したモノマーを、溶液重合法、エマルション重合法、バルク重合法、懸濁重合法、光重合法等の公知の手法により重合させることで作製することができる。
　ポリマー（Ｂ）の分子量を調整するために、必要に応じて連鎖移動剤を用いることができる。使用する連鎖移動剤の例としては、ｔ－ドデシルメルカプタン、メルカプトエタノール、α－チオグリセロール等のメルカプト基を有する化合物；チオグリコール酸、チオグリコール酸メチル等のチオグリコール酸エステル類；α－メチルスチレンダイマー；等が挙げられる。連鎖移動剤の使用量は特に制限されず、所望の分子量を有するポリマー（Ｂ）が得られるように適宜設定し得る。いくつかの態様において、モノマー１００重量部に対する連鎖移動剤の使用量は、例えば０．１～５重量部であってよく、０．２～３重量部でもよく、０．５～２重量部でもよい。 The polymer (B) can be produced, for example, by polymerizing the above-mentioned monomer by a known method such as a solution polymerization method, an emulsion polymerization method, a bulk polymerization method, a suspension polymerization method, or a photopolymerization method.
Chain transfer agents can be used as needed to adjust the molecular weight of the polymer (B). Examples of chain transfer agents used include compounds having a mercapto group such as t-dodecyl mercaptoethanol, mercaptoethanol, α-thioglycerol; thioglycolic acid esters such as thioglycolic acid and methyl thioglycolate; α-methylstyrene. Dimer; etc. The amount of the chain transfer agent used is not particularly limited, and can be appropriately set so that the polymer (B) having a desired molecular weight can be obtained. In some embodiments, the amount of the chain transfer agent used per 100 parts by weight of the monomer may be, for example, 0.1 to 5 parts by weight, 0.2 to 3 parts by weight, or 0.5 to 2 parts by weight. good.

　ベースポリマー（例えば、アクリル系ポリマー）１００重量部に対するポリマー（Ｂ）の使用量は、例えば０．００１重量部以上とすることができ、より高い使用効果を得る観点から０．０１重量部以上としてもよく、０．０３重量部以上としてもよい。また、上記ポリマー（Ｂ）の使用量は、例えば３重量部以下であってよく、屈折率への影響を軽減する観点から１重量部以下とすることが適当であり、０．５重量部以下でもよく、０．１重量部以下でもよい。 The amount of the polymer (B) used with respect to 100 parts by weight of the base polymer (for example, acrylic polymer) can be, for example, 0.001 part by weight or more, and 0.01 part by weight or more from the viewpoint of obtaining a higher use effect. It may be 0.03 part by weight or more. The amount of the polymer (B) used may be, for example, 3 parts by weight or less, and it is appropriate to use 1 part by weight or less from the viewpoint of reducing the influence on the refractive index, and 0.5 parts by weight or less. However, it may be 0.1 parts by weight or less.

　（無機粒子）
　ここに開示される技術は、屈折率向上剤としての無機粒子を実質的に使用しない態様で好ましく実施することができる。もっとも、ここに開示される技術の適用効果を大きく損なわない限度で、屈折率向上剤として無機粒子を使用することは許容され得る。屈折率向上剤として使用し得る無機粒子の例としては、チタニア（酸化チタン、ＴｉＯ２）、ジルコニア（酸化ジルコニウム、ＺｒＯ２）、酸化アルミニウム、酸化亜鉛、酸化スズ、酸化銅、チタン酸バリウム、酸化ニオブ（Ｎｂ２Ｏ５等）等の無機酸化物（具体的には金属酸化物）により構成された無機粒子が挙げられる。上記無機粒子の平均粒径（レーザ散乱・回折法に基づく５０％体積平均粒子径をいう。）は、例えば１０ｎｍ～１００ｎｍ程度の範囲から選択し得る。なお、無機粒子の屈折率は、当該無機粒子を構成する材料の単層膜（屈折率測定が可能な膜厚とする。）につき、市販の分光エリプソメーターを用いて、測定波長５８９ｎｍ、測定温度２３℃の条件で測定される。分光エリプソメーターとしては、例えば製品名「ＥＣ－４００」（ＪＡ．Ｗｏｏｌａｍ社製）またはその相当品が用いられる。屈折率向上剤として無機粒子を使用する場合における使用量は、ベースポリマー１００重量部に対して５重量部未満とすることが好ましく、１重量部未満とすることがより好ましい。添加剤（ＨＲＯ）を使用する態様では、上記無機粒子の使用量は、重量基準で、上記添加剤（ＨＲＯ）の使用量の２倍以下とすることが好ましく、１倍以下または０．５倍以下とすることがより好ましい。 (Inorganic particles)
The technique disclosed herein can be preferably carried out in a manner in which inorganic particles as a refractive index improver are substantially not used. However, it is permissible to use inorganic particles as the refractive index improver as long as the application effect of the technique disclosed herein is not significantly impaired. Examples of inorganic particles that can be used as a refractive index improver include titania (titanium oxide, TiO 2 ), zirconia ( zinc oxide, ZrO 2 ), aluminum oxide, zinc oxide, tin oxide, copper oxide, barium titanate, and oxidation. Examples thereof include inorganic particles composed of inorganic oxides (specifically, metal oxides) such as niobium (Nb 2 O 5 and the like). The average particle size of the inorganic particles (referring to the 50% volume average particle size based on the laser scattering / diffraction method) can be selected from the range of, for example, about 10 nm to 100 nm. The refractive index of the inorganic particles is determined by using a commercially available spectroscopic ellipsometer for a single-layer film (a film thickness capable of measuring the refractive index) of the material constituting the inorganic particles, with a measurement wavelength of 589 nm and a measurement temperature. It is measured under the condition of 23 ° C. As the spectroscopic ellipsometer, for example, the product name "EC-400" (manufactured by JA.Woolam) or an equivalent product thereof is used. When the inorganic particles are used as the refractive index improver, the amount used is preferably less than 5 parts by weight and more preferably less than 1 part by weight with respect to 100 parts by weight of the base polymer. In embodiments using additives (H RO), the amount of the inorganic particles, by weight, is preferably not more than 2 times the amount of the additive (H RO), 1 times or less or 0. More preferably, it is 5 times or less.

　（架橋剤）
　ここに開示される技術において、粘着剤層（粘弾性層Ｖ１および／または粘弾性層Ｖ２であり得る。）の形成に使用する粘着剤組成物には、粘着剤の凝集力の調整等の目的で、必要に応じて架橋剤を含有させることができる。架橋剤としては、イソシアネート系架橋剤、エポキシ系架橋剤、アジリジン系架橋剤、オキサゾリン系架橋剤、メラミン系樹脂、金属キレート系架橋剤等の、粘着剤の分野において公知の架橋剤を使用することができる。なかでもイソシアネート系架橋剤を好ましく採用し得る。架橋剤の他の例として、１分子内に２以上のエチレン性不飽和基を有するモノマー、すなわち多官能性モノマーが挙げられる。架橋剤は、１種を単独でまたは２種以上を組み合わせて用いることができる。 (Crosslinking agent)
In the art disclosed herein, the PSA composition used to form the pressure-sensitive adhesive layer (which may be a viscoelastic layer V 1 and / or viscoelastic layer V 2.), Adjustment of the cohesive force of the pressure-sensitive adhesive For the purpose of, a cross-linking agent can be contained if necessary. As the cross-linking agent, a cross-linking agent known in the field of adhesives such as an isocyanate-based cross-linking agent, an epoxy-based cross-linking agent, an aziridine-based cross-linking agent, an oxazoline-based cross-linking agent, a melamine-based resin, and a metal chelate-based cross-linking agent shall be used. Can be done. Of these, an isocyanate-based cross-linking agent can be preferably used. Another example of the cross-linking agent is a monomer having two or more ethylenically unsaturated groups in one molecule, that is, a polyfunctional monomer. The cross-linking agent may be used alone or in combination of two or more.

　イソシアネート系架橋剤としては、２官能以上のイソシアネート化合物を用いることができ、例えば、トリメチレンジイソシアネート、ブチレンジイソシアネート、ヘキサメチレンジイソシアネート（ＨＤＩ）、ダイマー酸ジイソシアネートなどの脂肪族ポリイソシアネート類；シクロペンチレンジイソシアネート、シクロヘキシレンジイソシアネート、イソホロンジイソシアネート（ＩＰＤＩ）、１，３－ビス（イソシアナトメチル）シクロヘキサンなどの脂環族イソシアネート類；２，４－トリレンジイソシアネート、４，４’－ジフェニルメタンジイソシアネート、キシリレンジイソシアネート（ＸＤＩ）などの芳香族イソシアネート類；上記イソシアネート化合物をアロファネート結合、ビウレット結合、イソシアヌレート結合、ウレトジオン結合、ウレア結合、カルボジイミド結合、ウレトンイミン結合、オキサジアジントリオン結合などにより変性したポリイソシネート変性体；などが挙げられる。市販品の例としては、商品名タケネート３００Ｓ、タケネート５００、タケネート６００、タケネートＤ１６５Ｎ、タケネートＤ１７８Ｎ（以上、武田薬品工業社製）、スミジュールＴ８０、スミジュールＬ、デスモジュールＮ３４００（以上、住化バイエルウレタン社製）、ミリオネートＭＲ、ミリオネートＭＴ、コロネートＬ、コロネートＨＬ、コロネートＨＸ（以上、東ソー社製）などが挙げられる。イソシアネート化合物は、１種を単独でまたは２種以上を組み合わせて用いることができる。２官能のイソシアネート化合物と３官能以上のイソシアネート化合物を併用してもよい。 As the isocyanate-based cross-linking agent, a bifunctional or higher functional isocyanate compound can be used, for example, aliphatic polyisocyanates such as trimethylene diisocyanate, butylene diisocyanate, hexamethylene diisocyanate (HDI), and dimerate diisocyanate; cyclopentylene diisocyanate. , Cyclohexylene diisocyanate, isophorone diisocyanate (IPDI), alicyclic isocyanates such as 1,3-bis (isocyanatomethyl) cyclohexane; 2,4-tolylene diisocyanate, 4,4'-diphenylmethane diisocyanate, xylylene diisocyanate (xylylene diisocyanate) Aromatic isocyanates such as XDI); polyisocyanate modified products obtained by modifying the above isocyanate compounds with allophanate bonds, biuret bonds, isocyanurate bonds, uretdione bonds, urea bonds, carbodiimide bonds, uretonimine bonds, oxadiazine trione bonds, etc. Can be mentioned. Examples of commercially available products include trade names Takenate 300S, Takenate 500, Takenate 600, Takenate D165N, Takeda D178N (above, manufactured by Takeda Pharmaceutical Company Limited), Sumijuru T80, Sumijuru L, Death Module N3400 (above, Sumika Bayer). (Made by Urethane), Millionate MR, Millionate MT, Coronate L, Coronate HL, Coronate HX (all manufactured by Tosoh) and the like. The isocyanate compound may be used alone or in combination of two or more. A bifunctional isocyanate compound and a trifunctional or higher functional isocyanate compound may be used in combination.

　エポキシ系架橋剤としては、例えば、ビスフェノールＡ、エピクロルヒドリン型のエポキシ系樹脂、エチレングリシジルエーテル、ポリエチレングリコールジグリシジルエーテル、グリセリンジグリシジルエーテル、グリセリントリグリシジルエーテル、１，６－ヘキサンジオールグリシジルエーテル、トリメチロールプロパントリグリシジルエーテル、ジグリシジルアニリン、ジアミングリシジルアミン、Ｎ，Ｎ，Ｎ’，Ｎ’－テトラグリシジル－ｍ－キシリレンジアミンおよび１，３－ビス（Ｎ，Ｎ－ジグリシジルアミノメチル）シクロヘキサン等を挙げることができる。これらは１種を単独でまたは２種以上を組み合わせて用いることができる。 Examples of the epoxy-based cross-linking agent include bisphenol A, epichlorohydrin-type epoxy resin, ethylene glycidyl ether, polyethylene glycol diglycidyl ether, glycerin diglycidyl ether, glycerin triglycidyl ether, 1,6-hexanediol glycidyl ether, and trimethylol. Propanetriglycidyl ether, diglycidyl aniline, diglycidylamine, N, N, N', N'-tetraglycidyl-m-xylylenediamine, 1,3-bis (N, N-diglycidylaminomethyl) cyclohexane, etc. Can be mentioned. These can be used alone or in combination of two or more.

　多官能性モノマーとしては、例えば、エチレングリコールジ（メタ）アクリレート、プロピレングリコールジ（メタ）アクリレート、ポリエチレングリコールジ（メタ）アクリレート、ポリプロピレングリコールジ（メタ）アクリレート、ネオペンチルグリコールジ（メタ）アクリレート、ペンタエリスリトールジ（メタ）アクリレート、ペンタエリスリトールトリ（メタ）アクリレート、ジペンタエリスリトールヘキサ（メタ）アクリレート、エチレングリコールジ（メタ）アクリレート、１，６－ヘキサンジオールジ（メタ）アクリレート、１，１２－ドデカンジオールジ（メタ）アクリレート、トリメチロールプロパントリ（メタ）アクリレート、テトラメチロールメタントリ（メタ）アクリレート、アリル（メタ）アクリレート、ビニル（メタ）アクリレート、ジビニルベンゼン、ビスフェノキシエタノールフルオレンジ（メタ）アクリレート、ビスフェノールＡジ（メタ）アクリレート、エポキシアクリレート、ポリエステルアクリレート、ウレタンアクリレート、ブチルジオール（メタ）アクリレート、ヘキシルジオールジ（メタ）アクリレート等が挙げられる。多官能性モノマーは、１種を単独でまたは２種以上を組み合わせて用いることができる。 Examples of the polyfunctional monomer include ethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate, and the like. Pentaerythritol di (meth) acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol hexa (meth) acrylate, ethylene glycol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, 1,12-dodecane Didioldi (meth) acrylate, trimethylolpropantri (meth) acrylate, tetramethylolmethanetri (meth) acrylate, allyl (meth) acrylate, vinyl (meth) acrylate, divinylbenzene, bisphenoxyethanol full orange (meth) acrylate, bisphenol Examples thereof include A-di (meth) acrylate, epoxy acrylate, polyester acrylate, urethane acrylate, butyldiol (meth) acrylate, and hexyldiol di (meth) acrylate. The polyfunctional monomer may be used alone or in combination of two or more.

　架橋剤（多官能性モノマーであり得る。）を用いる場合における使用量は、特に限定されず、例えば、ベースポリマー１００重量部に対して０．００１重量部～５．０重量部程度の範囲とすることができる。粘着剤の柔軟性向上の観点から、いくつかの態様において、ベースポリマー１００重量部に対する架橋剤の使用量は、好ましくは３．０重量部以下、より好ましくは２．０重量部以下であり、１．０重量部以下でもよく、０．５重量部以下でもよく、０．２重量部以下でもよい。また、架橋剤の使用効果を適切に発揮する観点から、いくつかの態様において、ベースポリマー１００重量部に対する架橋剤の使用量は、例えば０．００５重量部以上であってよく、０．０１重量部以上であってもよく、０．０５重量部以上でもよく、０．０８重量部以上でもよい。 When a cross-linking agent (which may be a polyfunctional monomer) is used, the amount used is not particularly limited, and is, for example, in the range of about 0.001 part by weight to 5.0 parts by weight with respect to 100 parts by weight of the base polymer. can do. From the viewpoint of improving the flexibility of the pressure-sensitive adhesive, in some embodiments, the amount of the cross-linking agent used with respect to 100 parts by weight of the base polymer is preferably 3.0 parts by weight or less, more preferably 2.0 parts by weight or less. It may be 1.0 part by weight or less, 0.5 part by weight or less, or 0.2 part by weight or less. Further, from the viewpoint of appropriately exerting the effect of using the cross-linking agent, in some embodiments, the amount of the cross-linking agent used with respect to 100 parts by weight of the base polymer may be, for example, 0.005 parts by weight or more, and 0.01 weight by weight. It may be parts or more, 0.05 parts by weight or more, or 0.08 parts by weight or more.

　架橋反応をより効果的に進行させるために、架橋触媒を用いてもよい。架橋触媒の例としては、テトラ－ｎ－ブチルチタネート、テトライソプロピルチタネート、ナーセム第二鉄、ブチルスズオキシド、ジオクチルスズジラウレート等の金属系架橋触媒等が挙げられる。なかでも、ジオクチルスズジラウレート等のスズ系架橋触媒が好ましい。架橋触媒の使用量は特に制限されない。ベースポリマー１００重量部に対する架橋触媒の使用量は、架橋反応速度の速さと粘着剤組成物のポットライフの長さとのバランスを考慮して、例えば凡そ０．０００１重量部以上１重量部以下の範囲とすることができ、０．００１重量部以上０．５重量部以下の範囲とすることが好ましい。 A cross-linking catalyst may be used to allow the cross-linking reaction to proceed more effectively. Examples of the cross-linking catalyst include metal-based cross-linking catalysts such as tetra-n-butyl titanate, tetraisopropyl titanate, ferric nasem, butyl tin oxide, and dioctyl tin dilaurate. Of these, tin-based cross-linking catalysts such as dioctyl tin dilaurate are preferable. The amount of the cross-linking catalyst used is not particularly limited. The amount of the cross-linking catalyst used with respect to 100 parts by weight of the base polymer is, for example, in the range of about 0.0001 parts by weight or more and 1 part by weight or less in consideration of the balance between the speed of the cross-linking reaction rate and the length of the pot life of the pressure-sensitive adhesive composition. The range is preferably 0.001 part by weight or more and 0.5 part by weight or less.

　粘着剤組成物には、架橋遅延剤として、ケト－エノール互変異性を生じる化合物を含有させることができる。これにより、粘着剤組成物のポットライフを延長する効果が実現され得る。例えば、イソシアネート系架橋剤を含む粘着剤組成物において、ケト－エノール互変異性を生じる化合物を好ましく利用し得る。ケト－エノール互変異性を生じる化合物としては、各種のβ－ジカルボニル化合物を用いることができる。例えば、β－ジケトン類（アセチルアセトン、２，４－ヘキサンジオン等）やアセト酢酸エステル類（アセト酢酸メチル、アセト酢酸エチル等）を好ましく採用し得る。ケト－エノール互変異性を生じる化合物は、１種を単独でまたは２種以上を組み合わせて用いることができる。ケト－エノール互変異性を生じる化合物の使用量は、ベースポリマー１００重量部に対して、例えば０．１重量部以上２０重量部以下とすることができ、０．５重量部以上１０重量部以下としてもよく、１重量部以上５重量部以下としてもよい。 The pressure-sensitive adhesive composition can contain a compound that causes keto-enol tautomerism as a cross-linking retarder. Thereby, the effect of extending the pot life of the pressure-sensitive adhesive composition can be realized. For example, in a pressure-sensitive adhesive composition containing an isocyanate-based cross-linking agent, a compound that causes keto-enol tautomerism can be preferably used. Various β-dicarbonyl compounds can be used as the compound that causes keto-enol telecommunication. For example, β-diketones (acetylacetone, 2,4-hexanedione, etc.) and acetoacetic esters (methyl acetoacetate, ethyl acetoacetate, etc.) can be preferably adopted. The compounds that cause keto-enol tautomerism can be used alone or in combination of two or more. The amount of the compound that causes keto-enol telecommunication can be, for example, 0.1 parts by weight or more and 20 parts by weight or less, and 0.5 parts by weight or more and 10 parts by weight or less, based on 100 parts by weight of the base polymer. It may be 1 part by weight or more and 5 parts by weight or less.

　（粘着付与剤）
　ここに開示される技術における粘着剤層（粘弾性層Ｖ１および／または粘弾性層Ｖ２であり得る。）には、粘着付与剤を含有させてもよい。粘着付与剤としては、ロジン系粘着付与樹脂、テルペン系粘着付与樹脂、フェノール系粘着付与樹脂、炭化水素系粘着付与樹脂、ケトン系粘着付与樹脂、ポリアミド系粘着付与樹脂、エポキシ系粘着付与樹脂、エラストマー系粘着付与樹脂等の公知の粘着付与樹脂を用いることができる。これらは、１種を単独でまたは２種以上を組み合わせて用いることができる。粘着付与樹脂の使用量は特に限定されず、目的や用途に応じて適切な粘着性能が発揮されるように設定することができる。いくつかの態様において、屈折率や透明性の観点から、粘着付与剤の使用量は、粘着剤層のベースポリマー１００重量部に対して３０重量部以下とすることが適当であり、１０重量部以下とすることが好ましく、５重量部以下とすることがより好ましい。ここに開示される技術は、粘着付与剤を使用しない態様で好ましく実施され得る。 (Adhesive)
(Which may be a viscoelastic layer V 1 and / or viscoelastic layer V 2.) PSA layer in the art disclosed herein, the may contain a tackifier. Examples of the pressure-sensitive adhesive include rosin-based pressure-sensitive adhesive resin, terpen-based pressure-sensitive adhesive resin, phenol-based pressure-sensitive adhesive resin, hydrocarbon-based pressure-sensitive adhesive resin, ketone-based pressure-sensitive adhesive resin, polyamide-based pressure-sensitive adhesive resin, epoxy-based pressure-sensitive adhesive resin, and elastomer. A known pressure-sensitive adhesive resin such as a system-based pressure-sensitive adhesive resin can be used. These can be used alone or in combination of two or more. The amount of the tackifying resin used is not particularly limited, and can be set so as to exhibit appropriate adhesive performance according to the purpose and application. In some embodiments, from the viewpoint of refractive index and transparency, it is appropriate that the amount of the tackifier used is 30 parts by weight or less with respect to 100 parts by weight of the base polymer of the pressure-sensitive adhesive layer, and 10 parts by weight. It is preferably less than or equal to, and more preferably less than or equal to 5 parts by weight. The techniques disclosed herein can be preferably performed in a manner that does not use a tackifier.

　（その他の添加剤）
　ここに開示される技術において、粘着剤層（粘弾性層Ｖ１および／または粘弾性層Ｖ２であり得る。）の形成に使用する粘着剤組成物は、本発明の効果が著しく妨げられない範囲で、可塑剤、軟化剤、着色剤、帯電防止剤、老化防止剤、紫外線吸収剤、酸化防止剤、光安定剤、防腐剤等の、粘着剤組成物に使用され得る公知の添加剤を、必要に応じて含んでいてもよい。このような各種添加剤については、従来公知のものを常法により使用することができ、特に本発明を特徴づけるものではないので、詳細な説明は省略する。 (Other additives)
In the art disclosed herein, the PSA composition used to form the pressure-sensitive adhesive layer (which may be a viscoelastic layer V 1 and / or viscoelastic layer V 2.), The effect of the present invention is not hindered significantly To the extent, known additives that can be used in pressure-sensitive adhesive compositions, such as plasticizers, softeners, colorants, antistatic agents, anti-aging agents, UV absorbers, antioxidants, light stabilizers, preservatives, etc. , May be included as needed. As for such various additives, conventionally known ones can be used by a conventional method and do not particularly characterize the present invention, and thus detailed description thereof will be omitted.

　（剥離強度）
　ここに開示される層間シートのいくつかの態様において、該層間シートのガラス板に対する剥離強度は、凡そ１．０Ｎ／２５ｍｍ以上（例えば１．５Ｎ／２５ｍｍ以上）であることが適当であり、好ましくは２Ｎ／２５ｍｍ以上、より好ましくは３Ｎ／２５ｍｍ以上であり、４Ｎ／２５ｍｍ以上でもよく、６Ｎ／２５ｍｍ以上でもよく、８Ｎ／２５ｍｍ以上でもよく、１０Ｎ／２５ｍｍ以上でもよく、１２Ｎ／２５ｍｍ以上でもよい。剥離強度の上限は特に制限されず、例えば３０Ｎ／２５ｍｍ以下、２５Ｎ／２５ｍｍ以下または２０Ｎ／２５ｍｍ以下であり得る。 (Peeling strength)
In some aspects of the interlayer sheet disclosed herein, it is appropriate and preferable that the peel strength of the interlayer sheet with respect to the glass plate is about 1.0 N / 25 mm or more (for example, 1.5 N / 25 mm or more). Is 2N / 25mm or more, more preferably 3N / 25mm or more, 4N / 25mm or more, 6N / 25mm or more, 8N / 25mm or more, 10N / 25mm or more, 12N / 25mm or more. .. The upper limit of the peel strength is not particularly limited, and may be, for example, 30 N / 25 mm or less, 25 N / 25 mm or less, or 20 N / 25 mm or less.

　ここで、上記剥離強度は、被着体としてのアルカリガラス板に圧着して２３℃、５０％ＲＨの環境で３０分間放置し、次いで加圧脱泡装置（オートクレーブ）に投入して温度５０℃、圧力０．５ＭＰａの条件で３０分間のオートクレーブ処理を行い、さらに２３℃、５０％ＲＨの雰囲気下で２４時間放置した後に、剥離角度１８０度、引張速度３００ｍｍ／分の条件で１８０°引きはがし粘着力を測定することにより把握される。測定にあたっては、必要に応じて、測定対象の層間シートに適切な裏打ち材（例えば、厚さ２５μｍ程度～５０μｍ程度のポリエチレンテレフタレート（ＰＥＴ）フィルム）を貼り付けて補強することができる。剥離強度は、より具体的には、後述する実施例に記載の方法に準じて測定することができる。
　ここに開示される層間シートが第１粘着面および第２粘着面を有する両面粘着シートの形態である場合、いくつかの態様において、上述した剥離強度は、好ましくは少なくとも第１粘着面に適用され、より好ましくは第１粘着面および第２粘着面の両方に適用される。第１粘着面のガラス板に対する剥離強度と、第２粘着面のガラスに対する剥離強度とは、同程度であってもよく、異なっていてもよい。 Here, the peel strength is such that the peel strength is pressure-bonded to an alkaline glass plate as an adherend, left to stand in an environment of 23 ° C. and 50% RH for 30 minutes, and then put into a pressure defoaming device (autoclave) to have a temperature of 50 ° C. After autoclaving for 30 minutes under the condition of pressure of 0.5 MPa and further leaving for 24 hours in the atmosphere of 23 ° C. and 50% RH, peeling off by 180 ° under the condition of peeling angle of 180 degrees and tensile speed of 300 mm / min. It is grasped by measuring the adhesive strength. In the measurement, if necessary, an appropriate backing material (for example, a polyethylene terephthalate (PET) film having a thickness of about 25 μm to about 50 μm) can be attached to the interlayer sheet to be measured to reinforce it. More specifically, the peel strength can be measured according to the method described in Examples described later.
When the interlayer sheet disclosed herein is in the form of a double-sided adhesive sheet having a first adhesive surface and a second adhesive surface, in some embodiments, the above-mentioned peel strength is preferably applied to at least the first adhesive surface. , More preferably applied to both the first adhesive surface and the second adhesive surface. The peel strength of the first adhesive surface to the glass plate and the peel strength of the second adhesive surface to the glass may be the same or different.

＜粘弾性層Ｖ２＞
　ここに開示される層間シートのいくつかの好ましい態様において、該層間シートは、上述した粘弾性層Ｖ１に加えて、該粘弾性層Ｖ１に積層された粘弾性層（粘着剤層）Ｖ２をさらに含み得る。上記粘弾性層Ｖ２は、２５℃における貯蔵弾性率Ｇ’Ｖ２が、上記粘弾性層Ｖ１の２５℃における貯蔵弾性率Ｇ’Ｖ１より低いことが好ましい。すなわち、Ｇ’V2(25)＜Ｇ’V1(25)であることが好ましい。このような構成の層間シートは、粘弾性層Ｖ２の寄与により、より柔軟性に優れたものとなり得る。貯蔵弾性率Ｇ’V2(25)を貯蔵弾性率Ｇ’V1(25)よりも低くすることにより、層間シートにおいて、粘弾性層Ｖ１による高屈折率と、粘弾性層Ｖ2による柔軟性とを好ましく両立させることができる。粘弾性層Ｖ１に粘弾性層Ｖ２を積層することにより、密着性や柔軟性が付与されることで段差追従性や曲面等への追従性が改善され、多様なデバイスデザインの用途にも好ましく適用可能な層間シートが実現され得る。 <Viscoelastic layer V 2 >
In some preferred embodiments of the interlayer sheet disclosed herein, the interlayer sheet, in addition to the viscoelastic layer V 1 described above, the viscoelastic layer laminated on the viscoelastic layer V 1 (adhesive layer) V 2 may be further included. The viscoelastic layer V 2 is 'is V2, the storage modulus G 25 ° C. of the viscoelastic layer V 1' storage modulus G 25 ° C. is preferably lower than the V1. That is, it is preferable that G'V2 (25) <G'V1 (25). Such configuration interlayer sheet is due to the contribution of the viscoelastic layer V 2, it can be excellent in more flexible. By lower than the storage modulus G 'V2 (25) a storage modulus G' V1 (25), in an interlayer sheet, and a high refractive index due to the viscoelastic layer V 1, and the flexibility of the viscoelastic layer V 2 Can be preferably compatible with each other. By laminating the viscoelastic layer V 2 on the viscoelastic layer V 1 , adhesion and flexibility are imparted, and step followability and followability to curved surfaces are improved, making it suitable for various device design applications. Preferably applicable interlayer sheets can be realized.

　貯蔵弾性率Ｇ’V2(25)は、特に制限されず、例えば１．０ｋＰａ～５００ｋＰａの範囲であり得る。粘弾性層Ｖ２による柔軟性付与や変形に対する追従性向上の効果を高める観点から、いくつかの態様において、貯蔵弾性率Ｇ’V2(25)は、４００ｋＰａ以下であることが適当であり、３００ｋＰａ以下であることが好ましく、２００ｋＰａ以下（例えば１８０ｋＰａ以下、または１５０ｋＰａ）以下であることがより好ましく、１２０ｋＰａ以下でもよく、９０ｋＰａ以下でもよく、７０ｋＰａ以下でもよい。また、粘弾性層Ｖ２に適度な凝集性を付与する観点から、いくつかの態様において、貯蔵弾性率Ｇ’V2(25)は、５．０ｋＰａ以上であることが適当であり、１０ｋＰａ以上であることが好ましく、１５ｋＰａ以上でもよく、２５ｋＰａ以上でもよく、３５ｋＰａ以上でもよく、６０ｋＰａ以上でもよく、８０ｋＰａ以上でもよい。より高い凝集力や粘着特性を実現しやすくする観点から、いくつかの態様において、貯蔵弾性率Ｇ’V2(25)は、９５ｋＰａ以上でもよく、１１０ｋＰａ以上でもよく、１４０ｋＰａ以上でもよい。 Storage modulus G 'V2 (25) is not particularly limited, may be in the range, for example, 1.0 kPa ~ 500 kPa. From the viewpoint of enhancing the effect of the following improvement for softening or deformation due to the viscoelastic layer V 2, in some embodiments, the storage modulus G 'V2 (25) is suitably not more than 400 kPa, 300 kPa It is preferably 200 kPa or less (for example, 180 kPa or less, or 150 kPa) or less, and may be 120 kPa or less, 90 kPa or less, or 70 kPa or less. From the viewpoint of imparting an appropriate cohesiveness to the viscoelastic layer V 2, in some embodiments, the storage modulus G 'V2 (25) is suitably not less than 5.0 kPa, at 10kPa or more It may be 15 kPa or more, 25 kPa or more, 35 kPa or more, 60 kPa or more, or 80 kPa or more. From the viewpoint of easily realizing a higher cohesive force and adhesive properties, in some embodiments, the storage modulus G 'V2 (25) may be a more 95 kPa may at least 110 kPa, or at least 140 kPa.

　いくつかの態様では、粘弾性層（粘着剤層）Ｖ２の屈折率ｎ２は、粘弾性層（粘着剤層）Ｖ１の屈折率ｎ１より低い。かかる構成を有する層間シートによると、粘弾性層Ｖ１，Ｖ２の屈折率差を利用して、該層間シートを透過する光の挙動を制御することができる。かかる態様において、粘着剤層Ｖ２の屈折率ｎ２は、粘着剤層Ｖ１の屈折率ｎ１よりも低ければ特に制限されず、例えば１．３５～１．５５程度の範囲内であり得る。いくつかの態様において、粘弾性層Ｖ１の屈折率ｎ１との屈折率差を大きくして後述する正面輝度向上効果を高めやすくする観点から、粘弾性層Ｖ２の屈折率ｎ２は、例えば１．４９以下であることが好ましく、１．４７以下（例えば１．４６以下、または１．４５以下）であることがより好ましく、１．４３以下でもよく、１．４１以下でもよく、１．４０以下でもよい。また、材料の入手容易性や粘着特性との両立容易性の観点から、いくつかの態様において、粘弾性層Ｖ２の屈折率ｎ２は、例えば１．３６以上であってよく、１．３８以上であってもよく、１．４０以上であってもよく、１．４２以上であってもよい。 In some embodiments, the viscoelastic layer (adhesive layer) The refractive index n 2 of the V 2 are viscoelastic layer (adhesive layer) lower than the refractive index n 1 of V 1. According to the interlayer sheet having such a configuration, by utilizing the refractive index difference of the viscoelastic layer V 1, V 2, it is possible to control the behavior of light transmitted through the interlayer sheet. In such embodiments, the refractive index n 2 of the pressure-sensitive adhesive layer V 2, if lower than the refractive index n 1 of the pressure-sensitive adhesive layer V 1 is not particularly limited, it may be, for example, in the range of about 1.35 to 1.55 .. In some embodiments, from the viewpoint of easily increasing the front brightness enhancement effect to be described later by increasing the difference in refractive index between the refractive index n 1 of the viscoelastic layer V 1, the refractive index n 2 of the viscoelastic layer V 2 is For example, it is preferably 1.49 or less, more preferably 1.47 or less (for example, 1.46 or less, or 1.45 or less), 1.43 or less, 1.41 or less, and 1 It may be .40 or less. From the viewpoint of compatibility easily with the easy availability and adhesive properties of the material, in some embodiments, the refractive index n 2 of the viscoelastic layer V 2 may be for example 1.36 or more, 1.38 It may be more than or equal to, 1.40 or more, or 1.42 or more.

　粘弾性層Ｖ２を構成する粘着剤の種類は特に限定されない。粘弾性層Ｖ２を構成する粘着剤は、粘着剤の分野において用いられ得るアクリル系ポリマー、ゴム系ポリマー（例えば天然ゴム、合成ゴム、これらの混合物等）、ポリエステル系ポリマー、ウレタン系ポリマー、ポリエーテル系ポリマー、シリコーン系ポリマー、ポリアミド系ポリマー、フッ素系ポリマー等の各種ゴム状ポリマーの１種または２種以上をベースポリマーとして含むものであり得る。粘着性能やコスト等の観点から、アクリル系ポリマーまたはゴム系ポリマーをベースポリマーとして含む粘着剤を好ましく採用し得る。なかでもアクリル系ポリマーをベースポリマーとする粘着剤（アクリル系粘着剤）が好ましい。粘弾性層Ｖ１がアクリル系粘着剤層である態様では、粘弾性層Ｖ１と粘弾性層Ｖ２との密着性の観点から、粘弾性層Ｖ２がアクリル系粘着剤層である構成を好ましく採用し得る。 The type of the pressure-sensitive adhesive constituting the viscoelastic layer V 2 is not particularly limited. The pressure-sensitive adhesive constituting the viscoelastic layer V 2 is an acrylic polymer, a rubber-based polymer (for example, natural rubber, synthetic rubber, a mixture thereof, etc.), a polyester-based polymer, a urethane-based polymer, or a poly, which can be used in the field of pressure-sensitive adhesives. It may contain one or more of various rubber-like polymers such as an ether-based polymer, a silicone-based polymer, a polyamide-based polymer, and a fluorine-based polymer as a base polymer. From the viewpoint of adhesive performance, cost, and the like, a pressure-sensitive adhesive containing an acrylic polymer or a rubber-based polymer as a base polymer can be preferably adopted. Of these, a pressure-sensitive adhesive (acrylic pressure-sensitive adhesive) using an acrylic polymer as a base polymer is preferable. In embodiments viscoelastic layer V 1 is an acrylic pressure-sensitive adhesive layer, from the viewpoint of adhesion between the viscoelastic layer V 1 and the viscoelastic layer V 2, the configuration viscoelastic layer V 2 is an acrylic pressure-sensitive adhesive layer It can be preferably adopted.

　いくつかの態様において、上記アクリル系ポリマーとしては、例えば、アルキル（メタ）アクリレートを含み、該アルキル（メタ）アクリレートと共重合性を有する他のモノマー（共重合性モノマー）をさらに含み得るモノマー原料の重合物が好ましい。モノマー原料における上記アルキル（メタ）アクリレートの含有量は、例えば１０重量％以上であってよく、２５重量％以上でもよく、３５重量％以上でもよく、４５重量％以上でもよい。上記アクリル系ポリマーは、アルキル（メタ）アクリレートを主モノマーとして含み、上記共重合性モノマーを副モノマーとしてさらに含み得るモノマー成分の重合物であってもよい。ここで主モノマーとは、上記モノマー原料におけるモノマー組成の５０重量％超を占める成分をいう。上記モノマー組成の５５重量％超または６０重量％超がアルキル（メタ）アクリレートであってもよい。 In some embodiments, the acrylic polymer includes, for example, an alkyl (meth) acrylate and may further contain another monomer (copolymerizable monomer) copolymerizable with the alkyl (meth) acrylate. Polymers are preferred. The content of the alkyl (meth) acrylate in the monomer raw material may be, for example, 10% by weight or more, 25% by weight or more, 35% by weight or more, or 45% by weight or more. The acrylic polymer may be a polymer of a monomer component containing an alkyl (meth) acrylate as a main monomer and further containing the copolymerizable monomer as a submonomer. Here, the main monomer means a component that occupies more than 50% by weight of the monomer composition in the above-mentioned monomer raw material. More than 55% by weight or more than 60% by weight of the above monomer composition may be alkyl (meth) acrylate.

　アルキル（メタ）アクリレートとしては、例えば下記式（１）で表される化合物を好ましく使用することができる。
　ＣＨ２＝Ｃ（Ｒ１）ＣＯＯＲ２　　　　　（１）
　ここで、上記式（１）中のＲ１は水素原子またはメチル基である。また、Ｒ２は炭素原子数１～２０の鎖状アルキル基（以下、このような炭素原子数の範囲を「Ｃ１－２０」と表すことがある。）である。粘着剤の貯蔵弾性率等の観点から、Ｒ２がＣ１－１２（例えばＣ２－１０、典型的にはＣ４－８）の鎖状アルキル基であるアルキル（メタ）アクリレートが好ましい。上記Ｒ２がＣ１－２０の鎖状アルキル基であるアルキル（メタ）アクリレートは、１種を単独でまたは２種以上を組み合わせて用いることができる。好ましいアルキル（メタ）アクリレートとして、ｎ－ブチルアクリレートおよび２－エチルヘキシルアクリレートが挙げられる。 As the alkyl (meth) acrylate, for example, a compound represented by the following formula (1) can be preferably used.
CH 2 = C (R 1 ) COOR 2 (1)
Here, R 1 in the above formula (1) is a hydrogen atom or a methyl group. Further, R 2 is a chain alkyl group having 1 to 20 carbon atoms (hereinafter, such a range of carbon atoms may be referred to as “C 1-20”). From the viewpoint of the storage elastic modulus of the pressure-sensitive adhesive, alkyl (meth) acrylate in which R 2 is a chain alkyl group of C 1-12 (for example, C 2-10 , typically C 4-8) is preferable. The alkyl (meth) acrylate in which R 2 is a chain alkyl group of C 1-20 may be used alone or in combination of two or more. Preferred alkyl (meth) acrylates include n-butyl acrylate and 2-ethylhexyl acrylate.

　上記共重合性モノマーは、アクリル系ポリマーに架橋点を導入したり、アクリル系ポリマーの凝集力を高めたりするために役立ち得る。上記共重合性モノマーとしては、例えばカルボキシ基含有モノマー、水酸基含有モノマー、酸無水物基含有モノマー、アミド基含有モノマー、アミノ基含有モノマー、窒素原子含有環を有するモノマー、スルホン酸基含有モノマー、リン酸基含有モノマー等の官能基含有モノマーの１種または２種以上を使用することができる。共重合性モノマーの他の例として、酢酸ビニル等のビニルエステル系モノマー、スチレン等の芳香族ビニル化合物、非芳香族性環含有（メタ）アクリレート、アルコキシ基含有モノマー、等が挙げられる。具体例としては、粘弾性層Ｖ１のベースポリマーとして用いられ得るモノマーとして上述したもの等が挙げられるが、それらに限定されない。例えば、凝集力向上の観点から、上記共重合性モノマーとしてカルボキシ基含有モノマーおよび／または水酸基含有モノマーが共重合されたアクリル系ポリマーが好ましい。カルボキシ基含有モノマーの好適例としては、アクリル酸、メタクリル酸が挙げられる。水酸基含有モノマーの好適例としては、２－ヒドロキシエチルアクリレートや４－ヒドロキシブチルアクリレートが挙げられる。 The copolymerizable monomer can be useful for introducing cross-linking points into the acrylic polymer and enhancing the cohesive force of the acrylic polymer. Examples of the copolymerizable monomer include a carboxy group-containing monomer, a hydroxyl group-containing monomer, an acid anhydride group-containing monomer, an amide group-containing monomer, an amino group-containing monomer, a monomer having a nitrogen atom-containing ring, a sulfonic acid group-containing monomer, and phosphorus. One or more functional group-containing monomers such as an acid group-containing monomer can be used. Other examples of copolymerizable monomers include vinyl ester-based monomers such as vinyl acetate, aromatic vinyl compounds such as styrene, non-aromatic ring-containing (meth) acrylates, and alkoxy group-containing monomers. Specific examples, but like those described above as monomers that may be used as the base polymer of the viscoelastic layer V 1 is mentioned, but not limited to. For example, from the viewpoint of improving the cohesive force, an acrylic polymer in which a carboxy group-containing monomer and / or a hydroxyl group-containing monomer is copolymerized is preferable as the copolymerizable monomer. Preferable examples of the carboxy group-containing monomer include acrylic acid and methacrylic acid. Preferable examples of the hydroxyl group-containing monomer include 2-hydroxyethyl acrylate and 4-hydroxybutyl acrylate.

　いくつかの態様において、粘着剤層Ｖ２の屈折率ｎ２を低くするために、上記共重合性モノマーとしてフッ素含有モノマーを用いることができる。モノマー原料におけるフッ素含有モノマーの含有量は、例えば１０重量％以上であってよく、２５重量％以上でもよく、３５重量％以上でもよい。より屈折率の粘弾性層Ｖ２を実現しやすくする観点から、上記フッ素含有モノマーの含有量は、４０重量％以上であることが好ましく、４５重量％以上であることがより好ましく、５５重量％以上であることがさらに好ましく、６０重量％以上でもよく、７５重量％以上でもよく、８５重量％以上でもよく、９０重量％以上でもよく、９５重量％以上でもよい。モノマー原料におけるフッ素含有モノマーの含有量の上限は特に限定されず、１００重量％であってもよい。いくつかの態様において、粘弾性層Ｖ２の凝集性等の観点から、上記フッ素含有モノマーの含有量は、９９．９重量％以下であることが適当であり、９９．５以下であることが好ましく、９９重量％以下でもよく、９７重量％以下でもよく、９２重量％以下でもよい。フッ素含有モノマーは、１種を単独でまたは２種以上を組み合わせて用いることができる。 In some embodiments, a fluorine-containing monomer can be used as the copolymerizable monomer in order to lower the refractive index n 2 of the pressure-sensitive adhesive layer V 2. The content of the fluorine-containing monomer in the monomer raw material may be, for example, 10% by weight or more, 25% by weight or more, or 35% by weight or more. From the viewpoint of more easily achieve a viscoelastic layer V 2 of the refractive index, the content of the fluorine-containing monomer is preferably 40 wt% or more, more preferably 45 wt% or more, 55 wt% The above is more preferable, and it may be 60% by weight or more, 75% by weight or more, 85% by weight or more, 90% by weight or more, or 95% by weight or more. The upper limit of the content of the fluorine-containing monomer in the monomer raw material is not particularly limited, and may be 100% by weight. In some embodiments, from the viewpoint of cohesiveness, etc. viscoelastic layer V 2, the content of the fluorine-containing monomer is suitably to be at 99.9 wt% or less, it is 99.5 or less Preferably, it may be 99% by weight or less, 97% by weight or less, or 92% by weight or less. The fluorine-containing monomer may be used alone or in combination of two or more.

　フッ素含有モノマーとしては、フッ素含有アクリル系モノマーを好適に用いることができる。フッ素含有アクリル系モノマーとしては、分子内に少なくとも１つのフッ素原子を有しているアクリル系モノマーであれば特に制限されない。例えば、フッ素含有（メタ）アクリル酸エステルを好適に用いることができる。フッ素含有（メタ）アクリル酸エステルの好適例として、エステル末端にフッ素化炭化水素基を有するものが挙げられる。フッ素化炭化水素基としては、例えば、フッ素化脂肪族炭化水素基、フッ素化脂環式炭化水素基、フッ素化芳香族炭化水素基などが挙げられる。フッ素化炭化水素基としては、フッ素化脂肪族炭化水素基が好適である。フッ素化脂肪族炭化水素基としては、フッ素化アルキル基などが挙げられる。フッ素化脂肪族炭化水素基において、脂肪族炭化水素部位は、直鎖状であってもよく、分岐鎖状であってもよい。また、フッ素化脂肪族炭化水素基において、フッ素原子は、脂肪族炭化水素基部位のいずれの炭素原子に結合していてもよい。１つの炭素原子に結合しているフッ素原子は、単数であってもよく、複数であってもよい。フッ素原子が結合している炭素原子の数は特に制限されない。 As the fluorine-containing monomer, a fluorine-containing acrylic monomer can be preferably used. The fluorine-containing acrylic monomer is not particularly limited as long as it is an acrylic monomer having at least one fluorine atom in the molecule. For example, a fluorine-containing (meth) acrylic acid ester can be preferably used. Preferable examples of the fluorine-containing (meth) acrylic acid ester include those having a fluorinated hydrocarbon group at the ester terminal. Examples of the fluorinated hydrocarbon group include a fluorinated aliphatic hydrocarbon group, a fluorinated alicyclic hydrocarbon group, and a fluorinated aromatic hydrocarbon group. As the fluorinated hydrocarbon group, a fluorinated aliphatic hydrocarbon group is suitable. Examples of the fluorinated aliphatic hydrocarbon group include a fluorinated alkyl group. In the fluorinated aliphatic hydrocarbon group, the aliphatic hydrocarbon moiety may be linear or branched. Further, in the fluorinated aliphatic hydrocarbon group, the fluorine atom may be bonded to any carbon atom of the aliphatic hydrocarbon group moiety. The number of fluorine atoms bonded to one carbon atom may be singular or plural. The number of carbon atoms to which the fluorine atom is bonded is not particularly limited.

　フッ素化脂肪族炭化水素基（なかでも、フッ素化アルキル基）において、炭化水素基部位の炭素原子数は特に制限されない。いくつかの態様では、他の共重合性モノマーとの相溶性を考慮して、炭素原子数が例えば１～１８（好ましくは１～１２）程度のフッ素化脂肪族炭化水素基が好ましい。フッ化脂肪族炭化水素基の具体例としては、トリフルオロメチル基、ジフルオロメチル基、モノフルオロメチル基などのフッ化メチル基；ペンタフルオロエチル基、１，１，２，２－テトラフルオロエチル基、１，２，２，２－テトラフルオロエチル基、１，１，２－トリフルオロエチル基、１，２，２－トリフルオロエチル基、２，２，２－トリフルオロエチル基、１，１－ジフルオロエチル基、１，２－ジフルオロエチル基、２，２－ジフルオロエチル基、１－モノフルオロエチル基、２－モノフルオロエチル基などのフッ化エチル基；などが挙げられる。炭素原子数が３以上のフッ素化アルキル基としては、上記例示のフッ素化メチル基やフッ素化エチル基と同様に、アルキル基部位の炭素原子のうちいずれか１つ以上の炭素原子に単数または複数のフッ素原子が結合している種々のフッ素化アルキル基を例示することができる。 In the fluorinated aliphatic hydrocarbon group (among others, the fluorinated alkyl group), the number of carbon atoms at the hydrocarbon group site is not particularly limited. In some embodiments, a fluorinated aliphatic hydrocarbon group having, for example, about 1 to 18 (preferably 1 to 12) carbon atoms is preferable in consideration of compatibility with other copolymerizable monomers. Specific examples of the fluoride aliphatic hydrocarbon group include methyl fluoride groups such as trifluoromethyl group, difluoromethyl group and monofluoromethyl group; pentafluoroethyl group, 1,1,2,2-tetrafluoroethyl group. , 1,2,2,2-tetrafluoroethyl group, 1,1,2-trifluoroethyl group, 1,2,2-trifluoroethyl group, 2,2,2-trifluoroethyl group, 1,1 -Difluoroethyl group, 1,2-difluoroethyl group, 2,2-difluoroethyl group, 1-monofluoroethyl group, 2-monofluoroethyl group and other ethyl fluoride groups; and the like. As the fluorinated alkyl group having 3 or more carbon atoms, as in the case of the above-exemplified methyl fluorinated group and ethyl fluorinated group, one or more carbon atoms in any one or more of the carbon atoms in the alkyl group moiety may be used. Various alkyl fluorinated groups to which the fluorine atom of the above is bonded can be exemplified.

　フッ素化脂環式炭化水素基としては、フッ素化シクロアルキル基などが挙げられる。上記フッ素化脂肪族炭化水素基と同様に、フッ素化脂環式炭化水素基において、フッ素原子は、脂環式炭化水素基のいずれの炭素原子に結合していてもよく、１つの炭素原子に結合しているフッ素原子は単数および複数のいずれであってもよい。さらに、フッ素原子が結合している炭素原子の数は特に制限されない。フッ素化脂環式炭化水素基には、例えば、２－フルオロシクロヘキシル基、３－フルオロシクロヘキシル基、４－フルオロシクロヘキシル基などのフッ素原子を１つ有するシクロヘキシル基；２，４－ジフルオロシクロヘキシル基、２，６－ジフルオロシクロヘキシル基などのフッ素原子を２つ有するシクロヘキシル基；２，４，６－トリフルオロシクロヘキシル基などのフッ素原子を３つ有するシクロヘキシル基等が含まれる。 Examples of the fluorinated alicyclic hydrocarbon group include a fluorinated cycloalkyl group. Similar to the above-mentioned fluorinated aliphatic hydrocarbon group, in the fluorinated alicyclic hydrocarbon group, the fluorine atom may be bonded to any carbon atom of the alicyclic hydrocarbon group into one carbon atom. The bonded fluorine atom may be singular or plural. Further, the number of carbon atoms to which the fluorine atom is bonded is not particularly limited. The fluorinated alicyclic hydrocarbon group includes, for example, a cyclohexyl group having one fluorine atom such as a 2-fluorocyclohexyl group, a 3-fluorocyclohexyl group, and a 4-fluorocyclohexyl group; a 2,4-difluorocyclohexyl group, 2 , A cyclohexyl group having two fluorine atoms such as a 6-difluorocyclohexyl group; a cyclohexyl group having three fluorine atoms such as a 2,4,6-trifluorocyclohexyl group and the like are included.

　フッ素化炭化水素基は、置換基を有していなくてもよく、有していてもよい。このような置換基としては、特に制限されず、例えば、アルキル基等の炭化水素基、アルコキシ基、ヒドロキシ基、カルボキシ基、アミノ基、ニトロ基、シアノ基、ハロゲン原子などが挙げられる。置換基は、１種を単独でまたは２種以上を組み合わせて用いることができる。 The fluorinated hydrocarbon group may or may not have a substituent. Such a substituent is not particularly limited, and examples thereof include a hydrocarbon group such as an alkyl group, an alkoxy group, a hydroxy group, a carboxy group, an amino group, a nitro group, a cyano group, and a halogen atom. As the substituent, one type may be used alone or two or more types may be used in combination.

　フッ素原子含有（メタ）アクリル酸エステル［フッ素化（メタ）アクリレート］には、例えば、フッ素原子含有（メタ）アクリル酸アルキルエステル［フッ素化アルキル（メタ）アクリレート］、フッ素原子含有（メタ）アクリル酸シクロアルキルエステル［フッ素化シクロアルキル（メタ）アクリレート］、フッ素原子含有（メタ）アクリル酸アリールエステル［フッ素化アリール（メタ）アクリレート］などが含まれる。 Fluorine atom-containing (meth) acrylic acid ester [fluorinated (meth) acrylate] includes, for example, fluorine atom-containing (meth) acrylic acid alkyl ester [fluorinated alkyl (meth) acrylate] and fluorine atom-containing (meth) acrylic acid. Cycloalkyl esters [fluorinated cycloalkyl (meth) acrylates], fluorine atom-containing (meth) acrylic acid aryl esters [fluorinated aryl (meth) acrylates] and the like are included.

　フッ素原子含有（メタ）アクリル酸エステルとしては、フッ素化アルキル（メタ）アクリレート（特に、フッ素化アルキルアクリレート）が好適である。フッ素化アルキル（メタ）アクリレートとしては、例えば、２，２，２－トリフルオロエチルアクリレート（大阪有機化学工業株式会社製の商品名「ビスコート３Ｆ」など）、２，２，３，３－テトラフルオロプロピルアクリレート（大阪有機化学工業株式会社製の商品名「ビスコート４Ｆ」など）、１Ｈ，１Ｈ，５Ｈ－オクタフルオロペンチルアクリレート（大阪有機化学工業株式会社製の商品名「ビスコート８Ｆ」など）、１Ｈ，１Ｈ，５Ｈ－オクタフルオロペンチルメタクリレート（大阪有機化学工業株式会社製の商品名「ビスコート８ＦＭ」など）、２－（ヘプタデカフルオロノニル）エチルアクリレート（共栄社化学株式会社製の商品名「ＦＡ－１０８」など）、１Ｈ，１Ｈ，２Ｈ，２Ｈ－トリデカフルオロオクチルアクリレート（大阪有機化学工業株式会社製の商品名「ビスコート１３Ｆ」など）、などが挙げられる。 As the fluorine atom-containing (meth) acrylic acid ester, fluorinated alkyl (meth) acrylate (particularly, fluorinated alkyl acrylate) is suitable. Examples of the alkyl fluorinated (meth) acrylate include 2,2,2-trifluoroethyl acrylate (trade name "Viscoat 3F" manufactured by Osaka Organic Chemical Industry Co., Ltd.), 2,2,3,3-tetrafluoro. Propyl acrylate (trade name "Viscoat 4F" manufactured by Osaka Organic Chemical Industry Co., Ltd.), 1H, 1H, 5H-octafluoropentyl acrylate (trade name "Viscoat 8F" manufactured by Osaka Organic Chemical Industry Co., Ltd.), 1H, 1H, 5H-octafluoropentyl methacrylate (trade name "Viscoat 8FM" manufactured by Osaka Organic Chemical Industry Co., Ltd.), 2- (Heptadecafluorononyl) ethyl acrylate (trade name "FA-108" manufactured by Kyoeisha Chemical Co., Ltd.) Etc.), 1H, 1H, 2H, 2H-tridecafluorooctyl acrylate (trade name "Viscoat 13F" manufactured by Osaka Organic Chemical Industry Co., Ltd.), and the like.

　フッ素化アルキル（メタ）アクリレートにおけるフッ素化アルキル基の炭素原子数は、低屈折率化効果や柔軟性等の観点から、３以上であることが有利であり、４以上であることが好ましく、５以上であることがより好ましく、６以上または７以上であることがさらに好ましく、８以上であることが特に好ましい。上記フッ素化アルキル基の炭素原子数は、粘着性能等の観点から、１８以下であることが有利であり、１４以下であることが好ましく、１２以下であることがより好ましく、１０以下でもよく、９以下でもよい。いくつかの態様において、上記フッ素化アルキル基の炭素原子数は、７以下でもよく、５以下でもよい。また、いくつかの態様において、フッ素原子含有（メタ）アクリル酸エステルとしては、アルキル基の１位の炭素にフッ素が結合していないフッ素化アルキル（メタ）アクリレートが好ましく、例えば１Ｈ，１Ｈ，２Ｈ，２Ｈ－トリデカフルオロオクチルアクリレートのように、アルキル基の１位の炭素および２位の炭素のいずれにもフッ素が結合していないフッ素化アルキル（メタ）アクリレートを好ましく採用し得る。 The number of carbon atoms of the fluorinated alkyl group in the fluorinated alkyl (meth) acrylate is preferably 3 or more, preferably 4 or more, from the viewpoint of the effect of lowering the refractive index, flexibility, and the like. The above is more preferable, 6 or more or 7 or more is further preferable, and 8 or more is particularly preferable. From the viewpoint of adhesive performance and the like, the number of carbon atoms of the fluorinated alkyl group is preferably 18 or less, preferably 14 or less, more preferably 12 or less, and may be 10 or less. It may be 9 or less. In some embodiments, the alkyl fluorinated group may have 7 or less carbon atoms or 5 or less carbon atoms. In some embodiments, the fluorine atom-containing (meth) acrylic acid ester is preferably a fluorinated alkyl (meth) acrylate in which fluorine is not bonded to the carbon at the 1-position of the alkyl group, for example, 1H, 1H, 2H. , 2H-Tridecafluorooctyl acrylate, a fluorinated alkyl (meth) acrylate in which fluorine is not bonded to either the 1-position carbon or the 2-position carbon of the alkyl group can be preferably adopted.

　ここに開示される層間シートのいくつかの態様では、粘弾性層Ｖ２がアクリル系粘着剤層であり、該粘着剤のベースポリマーであるアクリル系ポリマーは、上述のようなフッ素含有アクリル系モノマー（例えば、フッ素化アルキル（メタ）アクリレート）を少なくとも含み、該フッ素含有アクリル系モノマーと共重合性を有する他のモノマー（共重合性モノマー）をさらに含んでもよいモノマー原料の重合物であり得る。このモノマー原料は、アルキル（メタ）アクリレートを含んでもよく、含まなくてもよい。上記モノマー原料におけるフッ素含有アクリル系モノマーの含有量は、例えば１０重量％以上であってよく、２５重量％以上でもよく、３５重量％以上でもよい。より低屈折率の粘弾性層Ｖ２を実現しやすくする観点から、上記フッ素含有アクリル系モノマーの含有量は、４０重量％以上であることが好ましく、４５重量％以上であることがより好ましく、５５重量％以上であることがさらに好ましく、６０重量％以上でもよく、７５重量％以上でもよく、８５重量％以上でもよく、９０重量％以上でもよく、９５重量％以上でもよい。モノマー原料におけるフッ素含有アクリル系モノマーの含有量の上限は特に限定されず、１００重量％であってもよい。いくつかの態様において、粘弾性層Ｖ２の凝集性等の観点から、上記フッ素含有アクリル系モノマーの含有量は、９９．９重量％以下であることが適当であり、９９．５以下であることが好ましく、９９重量％以下でもよく、９７重量％以下でもよく、９２重量％以下でもよい。フッ素含有アクリル系モノマーは、１種を単独でまたは２種以上を組み合わせて用いることができる。 In some embodiments of the interlayer sheet disclosed herein, the viscoelastic layer V 2 is an acrylic pressure-sensitive adhesive layer, the acrylic polymer as a base polymer of the pressure-sensitive adhesive is a fluorine-containing acrylic monomer as described above It may be a polymer of a monomer raw material containing at least (for example, an alkyl fluorinated (meth) acrylate) and may further contain another monomer (copolymerizable monomer) having copolymerizability with the fluorine-containing acrylic monomer. This monomer raw material may or may not contain an alkyl (meth) acrylate. The content of the fluorine-containing acrylic monomer in the monomer raw material may be, for example, 10% by weight or more, 25% by weight or more, or 35% by weight or more. From the viewpoint of more easily achieve a viscoelastic layer V 2 of a low refractive index, the content of the fluorine-containing acrylic monomer is preferably 40 wt% or more, more preferably 45 wt% or more, It is more preferably 55% by weight or more, 60% by weight or more, 75% by weight or more, 85% by weight or more, 90% by weight or more, or 95% by weight or more. The upper limit of the content of the fluorine-containing acrylic monomer in the monomer raw material is not particularly limited, and may be 100% by weight. In some embodiments, from the viewpoint of cohesiveness, etc. viscoelastic layer V 2, the content of the fluorine-containing acrylic monomer is suitably to be at 99.9 wt% or less, is 99.5 or less It is preferably 99% by weight or less, 97% by weight or less, and 92% by weight or less. The fluorine-containing acrylic monomer may be used alone or in combination of two or more.

　粘弾性層Ｖ２のベースポリマーを調製するためのモノマー原料は、フッ素含有アクリル系モノマー（例えば、フッ素化アルキル（メタ）アクリレート）に加えて、さらに共重合性モノマーを含む組成であり得る。上記共重合性モノマーとしては、例えばカルボキシ基含有モノマー、水酸基含有モノマー、酸無水物基含有モノマー、アミド基含有モノマー、アミノ基含有モノマー、窒素原子含有環を有するモノマー（例えば、Ｎ－ビニル－２－ピロリドン等のＮ－ビニル環状アミド）、スルホン酸基含有モノマー、リン酸基含有モノマー等の官能基含有モノマーの１種または２種以上を使用することができる。共重合性モノマーの他の例として、酢酸ビニル等のビニルエステル系モノマー、スチレン等の芳香族ビニル化合物、シクロアルキル（メタ）アクリレートやイソボルニル（メタ）アクリレート等の非芳香族性環含有（メタ）アクリレート、アルコキシ基含有モノマー；等が挙げられる。具体例としては、粘弾性層Ｖ１のベースポリマーとして用いられ得るモノマーとして上述したもの等が挙げられるが、それらに限定されない。例えば、凝集力向上の観点から、上記共重合性モノマーとしてカルボキシ基含有モノマーおよび／または水酸基含有モノマーが共重合されたアクリル系ポリマーが好ましい。 The monomer raw material for preparing the base polymer of the viscoelastic layer V 2 may have a composition further containing a copolymerizable monomer in addition to a fluorine-containing acrylic monomer (for example, fluorinated alkyl (meth) acrylate). Examples of the copolymerizable monomer include a carboxy group-containing monomer, a hydroxyl group-containing monomer, an acid anhydride group-containing monomer, an amide group-containing monomer, an amino group-containing monomer, and a monomer having a nitrogen atom-containing ring (for example, N-vinyl-2). -One or more functional group-containing monomers such as N-vinyl cyclic amides such as pyrrolidone), sulfonic acid group-containing monomers, and phosphoric acid group-containing monomers can be used. Other examples of copolymerizable monomers include vinyl ester-based monomers such as vinyl acetate, aromatic vinyl compounds such as styrene, and non-aromatic ring-containing (meth) such as cycloalkyl (meth) acrylate and isobornyl (meth) acrylate. Acrylate, alkoxy group-containing monomer; and the like can be mentioned. Specific examples, but like those described above as monomers that may be used as the base polymer of the viscoelastic layer V 1 is mentioned, but not limited to. For example, from the viewpoint of improving the cohesive force, an acrylic polymer in which a carboxy group-containing monomer and / or a hydroxyl group-containing monomer is copolymerized is preferable as the copolymerizable monomer.

　いくつかの好ましい態様において、粘弾性層Ｖ２のベースポリマーを調製するためのモノマー原料は、フッ素含有モノマー（例えば、フッ素化アルキル（メタ）アクリレート等のフッ素含有アクリル系モノマー）を含み、さらに水酸基含有モノマーを含む組成であり得る。水酸基含有モノマーは、凝集力の向上や架橋点の導入等に役立ち得る。水酸基含有モノマーの好適例としては、２－ヒドロキシエチルアクリレートや４－ヒドロキシブチルアクリレート等の（メタ）アクリル酸ヒドロキシアルキルが挙げられる。室温域における柔軟性向上の観点から、４－ヒドロキシブチルアクリレートがより好ましく用いられ得る。モノマー原料における水酸基含有モノマーの含有量は、特に制限されず、例えば０．０１重量％以上（好ましくは０．１重量％以上、より好ましくは０．５重量％以上）であり得る。いくつかの態様において、上記水酸基含有モノマーの含有量は、上記モノマー原料の０．７重量％以上であってもよく、０．９重量％以上であってもよく、１．５重量％以上であってもよい。水酸基含有モノマーの含有量の上限は特に限定されず、例えば１５重量％以下または１０重量％以下であり得る。いくつかの態様において、低屈折率化の観点から、上記モノマー原料における水酸基含有モノマーの含有量は、１０重量％未満であることが適当であり、５重量％未満とすることが好ましく、３重量％未満でもよく、２．５重量％未満でもよく、１．５重量％未満でもよい。 In some preferred embodiments, the monomer raw material for preparing the base polymer of the viscoelastic layer V 2 comprises a fluorine-containing monomer (e.g., a fluorinated alkyl (meth) fluorine-containing acrylic monomers such as acrylates), further hydroxyl It may have a composition containing a containing monomer. The hydroxyl group-containing monomer can be useful for improving the cohesive force and introducing cross-linking points. Preferable examples of the hydroxyl group-containing monomer include hydroxyalkyl (meth) acrylates such as 2-hydroxyethyl acrylate and 4-hydroxybutyl acrylate. From the viewpoint of improving flexibility in the room temperature range, 4-hydroxybutyl acrylate can be more preferably used. The content of the hydroxyl group-containing monomer in the monomer raw material is not particularly limited, and may be, for example, 0.01% by weight or more (preferably 0.1% by weight or more, more preferably 0.5% by weight or more). In some embodiments, the content of the hydroxyl group-containing monomer may be 0.7% by weight or more, 0.9% by weight or more, or 1.5% by weight or more of the monomer raw material. There may be. The upper limit of the content of the hydroxyl group-containing monomer is not particularly limited, and may be, for example, 15% by weight or less or 10% by weight or less. In some embodiments, from the viewpoint of lowering the refractive index, the content of the hydroxyl group-containing monomer in the monomer raw material is preferably less than 10% by weight, preferably less than 5% by weight, and 3% by weight. It may be less than%, less than 2.5% by weight, or less than 1.5% by weight.

　いくつかの態様において、粘弾性層Ｖ２のベースポリマーを調製するためのモノマー原料は、粘弾性層Ｖ２の着色または変色（例えば黄変）を抑制する観点から、カルボキシ基含有モノマーの含有量が制限されていることが好ましい。上記モノマー原料におけるカルボキシ基含有モノマーの含有量は、例えば１重量％未満であってよく、０．５重量％未満であることが好ましく、０．３重量％未満であることがより好ましく、０．１重量％未満（例えば０．０５重量％未満）であることがさらに好ましい。このようにカルボキシ基含有モノマーの含有量が制限されていることは、粘弾性層Ｖ２に接触または近接して配置され得る金属材料（例えば、被着体上に存在し得る金属配線や金属膜等）の腐食を抑制する観点からも有利である。ここに開示される層間シートは、上記モノマー原料がカルボキシ基含有モノマーを含有しない態様で好ましく実施され得る。
　同様の理由から、いくつかの態様において、粘弾性層Ｖ２のベースポリマーを調製するためのモノマー原料は、酸性官能基（カルボキシ基の他、スルホン酸基、リン酸基等を包含する。）を有するモノマーの含有量が制限されていることが好ましい。かかる態様のモノマー原料における酸性官能基含有モノマーの含有量としては、上述したカルボキシ基含有モノマーの好ましい含有量を適用することができる。ここに開示される層間シートは、上記モノマー原料が酸性基含有モノマーを含有しない態様（すなわち粘弾性層Ｖ２のベースポリマーが酸フリーである態様）で好ましく実施され得る。 In some embodiments, the monomer raw material for preparing the base polymer of the viscoelastic layer V 2, from the viewpoint of suppressing coloration or discoloration of the viscoelastic layer V 2 (e.g., yellowing), content of carboxyl group-containing monomer Is preferably restricted. The content of the carboxy group-containing monomer in the monomer raw material may be, for example, less than 1% by weight, preferably less than 0.5% by weight, more preferably less than 0.3% by weight, and 0. It is more preferably less than 1% by weight (for example, less than 0.05% by weight). Thus the content of the carboxyl group-containing monomer is restricted, the metallic material may be disposed in contact or in proximity to the viscoelastic layer V 2 (e.g., a metal wire or a metal film that may be present on an adherend Etc.), which is also advantageous from the viewpoint of suppressing corrosion. The interlayer sheet disclosed herein can be preferably carried out in a manner in which the monomer raw material does not contain a carboxy group-containing monomer.
For the same reasons, in some embodiments, the monomer raw material for preparing the base polymer of the viscoelastic layer V 2 are acidic functional groups (including other carboxyl group, a sulfonic acid group, a phosphoric acid group or the like.) It is preferable that the content of the monomer having is limited. As the content of the acidic functional group-containing monomer in the monomer raw material of such an embodiment, the above-mentioned preferable content of the carboxy group-containing monomer can be applied. Interlayer sheet disclosed herein may be preferably carried out in the manner described above monomer raw material does not contain an acidic group-containing monomer (i.e. aspect based polymer is an acid-free viscoelastic layer V 2).

　粘着剤層Ｖ２のベースポリマーは、粘着剤層Ｖ１のベースポリマーと同様、公知の重合方式を適宜採用して調製することができる。ベースポリマーの重量平均分子量（Ｍｗ）は、特に限定されず、例えば凡そ１０×１０４～５００×１０４の範囲であってよく、凡そ２０×１０４～２００×１０４の範囲であってもよい。いくつかの態様において、粘着剤層Ｖ１との密着性等の観点から、粘着剤層Ｖ２のベースポリマーのＭｗは、１５０×１０４以下であることが適当であり、１２０×１０４以下（例えば９５×１０４以下）であることが好ましく、７５×１０４以下でもよく、６８×１０４以下でもよく、６０×１０４以下でもよい。また、いくつかの態様において、粘着剤層Ｖ２の凝集性等の観点から、ベースポリマーのＭｗは、例えば３０×１０４以上であってよく、４０×１０４以上でもよく、５０×１０４以上でもよい。Ｍｗを調製するために、必要に応じて、従来公知の連鎖移動剤を使用することができる。 The base polymer of the pressure-sensitive adhesive layer V 2 can be prepared by appropriately adopting a known polymerization method like the base polymer of the pressure-sensitive adhesive layer V 1. The weight average molecular weight of the base polymer (Mw) of not particularly limited, for example, may range approximately of 10 × 10 4 ~ 500 × 10 4, be in the range of about 20 × 10 4 ~ 200 × 10 4 good. In some embodiments, from the viewpoint of adhesion with the adhesive layer V 1, Mw of the base polymer of the pressure-sensitive adhesive layer V 2 is suitably not less 0.99 × 10 4 or less, 120 × 10 4 or less (e.g. 95 × 10 4 or less) is preferably, it may be a 75 × 10 4 or less, may be a 68 × 10 4 or less, may be 60 × 10 4 or less. Further, in some embodiments, the Mw of the base polymer may be, for example, 30 × 10 4 or more, 40 × 10 4 or more, or 50 × 10 4 from the viewpoint of cohesiveness of the pressure-sensitive adhesive layer V 2. The above may be sufficient. Conventionally known chain transfer agents can be used to prepare Mw, if desired.

　特に限定するものではないが、接着性の観点から、粘着剤層Ｖ２のベースポリマー（例えばアクリル系ポリマー）のＴｇは、凡そ０℃以下であることが有利であり、好ましくは凡そ－５℃以下（例えば凡そ－１５℃以下、あるいは－２５℃以下）である。また、粘着剤層の凝集力の観点から、粘着剤層Ｖ２のベースポリマーのＴｇは、凡そ－７５℃以上であり、好ましくは凡そ－７０℃以上（例えば－５０℃以上、さらには－３０℃以上）である。ベースポリマーのＴｇは、モノマー組成（すなわち、該ポリマーの合成に使用するモノマーの種類や使用量比）を適宜変えることにより調整することができる。 Although not particularly limited, from the viewpoint of adhesiveness, Tg of the base polymer of the pressure-sensitive adhesive layer V 2 (e.g. acrylic polymer), is advantageously at about 0 ℃ less, preferably about -5 ° C. The following (for example, about −15 ° C. or lower, or −25 ° C. or lower). From the viewpoint of cohesive force of the adhesive layer, Tg of the base polymer of the pressure-sensitive adhesive layer V 2 is the approximately -75 ° C. or higher, preferably about -70 ° C. or higher (e.g., -50 ° C. or higher, more -30 ℃ or higher). The Tg of the base polymer can be adjusted by appropriately changing the monomer composition (that is, the type and amount ratio of the monomers used in the synthesis of the polymer).

　粘着剤層Ｖ２には、必要に応じて公知の架橋剤が用いられ得る。また、粘着剤層Ｖ２には、必要に応じて粘着付与剤その他の添加剤を含有させることができる。架橋剤や粘着付与剤は、粘着剤層Ｖ１に使用し得るものと同様のものから適宜選択し、適切な量を用いることができる。 A known cross-linking agent may be used for the pressure-sensitive adhesive layer V 2, if necessary. Further, the pressure-sensitive adhesive layer V 2 can contain a pressure-sensitive adhesive and other additives, if necessary. The cross-linking agent and the tackifier can be appropriately selected from the same ones that can be used for the pressure-sensitive adhesive layer V 1, and an appropriate amount can be used.

　粘着剤層Ｖ２の形成に使用する粘着剤組成物が架橋剤を含む態様において、上記架橋剤としては、例えばイソシアネート系架橋剤を好ましく採用し得る。いくつかの態様において、上記粘着剤組成物のベースポリマー１００重量部に対するイソシアネート系架橋剤の使用量は、粘着剤層Ｖ１との密着性等の観点から、例えば０．５重量部未満であってよく、０．３重量部未満でもよく、０．２重量部未満でもよく、０．１５重量部未満でもよい。また、架橋剤の使用効果を適切に発揮する観点から、いくつかの態様において、ベースポリマー１００重量部に対するイソシアネート系架橋剤の使用量は、例えば０．００５重量部以上であってよく、０．０１重量部以上であってもよく、０．０５重量部以上でもよく、０．０８重量部以上でもよい。 In an embodiment in which the pressure-sensitive adhesive composition used for forming the pressure-sensitive adhesive layer V 2 contains a cross-linking agent, for example, an isocyanate-based cross-linking agent can be preferably adopted as the cross-linking agent. In some embodiments, the amount of the isocyanate crosslinking agent relative to 100 parts by weight of the base polymer of the pressure-sensitive adhesive composition, from the viewpoint of adhesion with the adhesive layer V 1, for example, there is less than 0.5 part by weight It may be less than 0.3 parts by weight, less than 0.2 parts by weight, or less than 0.15 parts by weight. Further, from the viewpoint of appropriately exerting the effect of using the cross-linking agent, in some embodiments, the amount of the isocyanate-based cross-linking agent used per 100 parts by weight of the base polymer may be, for example, 0.005 parts by weight or more. It may be 01 parts by weight or more, 0.05 parts by weight or more, or 0.08 parts by weight or more.

＜粘着剤層の作製＞
　ここに開示される層間シートにおいて、粘弾性層Ｖ１，Ｖ２の各々を構成する粘弾性材料は、それぞれ、溶剤型、活性エネルギー線硬化型、水分散型、ホットメルト型等の形態の粘着剤組成物を、乾燥、架橋、重合、冷却等により硬化させてなる粘着剤、すなわち上記粘着剤組成物の硬化物であり得る。粘着剤組成物の硬化手段（例えば乾燥、架橋、重合、冷却等）は、１種のみを適用してもよく、２種以上を同時に、または多段階にわたって適用してもよい。溶剤型粘着剤組成物では、典型的には該組成物を乾燥（好ましくは、さらに架橋）させて粘着剤を形成することができる。活性エネルギー線硬化型粘着剤組成物では、典型的には活性エネルギー線を照射して重合反応および／または架橋反応を進行させることにより粘着剤が形成される。活性エネルギー線硬化型粘着剤組成物で乾燥させる必要がある場合は、乾燥後に活性エネルギー線を照射するとよい。 <Preparation of adhesive layer>
In the interlayer sheet disclosed herein, a viscoelastic material constituting each of the viscoelastic layer V 1, V 2, respectively, solvent type, active energy ray-curable, aqueous dispersion type pressure-sensitive adhesive in the form of a hot melt type or the like It can be a pressure-sensitive adhesive obtained by curing the agent composition by drying, cross-linking, polymerization, cooling, or the like, that is, a cured product of the pressure-sensitive adhesive composition. As the curing means (for example, drying, cross-linking, polymerization, cooling, etc.) of the pressure-sensitive adhesive composition, only one type may be applied, or two or more types may be applied simultaneously or in multiple stages. In solvent-based pressure-sensitive adhesive compositions, the composition can typically be dried (preferably further crosslinked) to form a pressure-sensitive adhesive. In the active energy ray-curable pressure-sensitive adhesive composition, a pressure-sensitive adhesive is typically formed by irradiating with active energy rays to proceed with a polymerization reaction and / or a cross-linking reaction. When it is necessary to dry with the active energy ray-curable pressure-sensitive adhesive composition, it is advisable to irradiate the active energy ray after drying.

　ここに開示される層間シートの粘弾性層Ｖ１，Ｖ２は、粘着剤組成物を適当な表面に付与（例えば塗布）した後、該組成物を硬化させることにより形成され得る。粘着剤組成物の塗布は、例えば、グラビアロールコーター、リバースロールコーター、キスロールコーター、ディップロールコーター、バーコーター、ナイフコーター、スプレーコーター等の慣用のコーターを用いて実施することができる。 The viscoelastic layers V 1 and V 2 of the interlayer sheet disclosed herein can be formed by applying (for example, applying) a pressure-sensitive adhesive composition to an appropriate surface and then curing the composition. The application of the pressure-sensitive adhesive composition can be carried out using a conventional coater such as a gravure roll coater, a reverse roll coater, a kiss roll coater, a dip roll coater, a bar coater, a knife coater, or a spray coater.

　ここに開示される層間シートにおいて、粘弾性層Ｖ１，Ｖ２のいずれか一方または両方は、後硬化性を有する粘着剤層であってもよく、後硬化性を有しない粘着剤層であってもよい。ここで、後硬化性を有する粘着剤層とは、熱または活性エネルギー線（例えば紫外線）の照射によってさらに硬化させることが可能な粘着剤層をいう。後硬化性を有する粘着剤層の例として、ベースポリマーの側鎖に未反応のエチレン性不飽和基を有する粘着剤層や、未反応の多官能性モノマーを含む粘着剤層が挙げられる。いくつかの態様において、粘着剤層は後硬化性を有しないことが好ましい。後硬化性を有しない粘着剤層は、後硬化反応に伴う寸法変化を生じない（すなわち、寸法安定性がよい）ので、粘着シートまたは該粘着シートが貼り付けられた被着体の反りを抑制しやすい。後硬化による寸法変化（例えば硬化収縮）が生じないことは、粘着剤層の光学歪を抑制する観点からも有利となり得る。 In the interlayer sheet disclosed herein, either one or both of the viscoelastic layers V 1 and V 2 may be a post-curable pressure-sensitive adhesive layer, which is a non-post-curable pressure-sensitive adhesive layer. You may. Here, the pressure-sensitive adhesive layer having post-curability refers to a pressure-sensitive adhesive layer that can be further cured by irradiation with heat or active energy rays (for example, ultraviolet rays). Examples of the post-curable pressure-sensitive adhesive layer include a pressure-sensitive adhesive layer having an unreacted ethylenically unsaturated group in the side chain of the base polymer, and a pressure-sensitive adhesive layer containing an unreacted polyfunctional monomer. In some embodiments, the pressure-sensitive adhesive layer preferably does not have post-curing properties. Since the pressure-sensitive adhesive layer having no post-curing property does not cause a dimensional change due to the post-curing reaction (that is, has good dimensional stability), it suppresses the warp of the pressure-sensitive adhesive sheet or the adherend to which the pressure-sensitive adhesive sheet is attached. It's easy to do. The fact that dimensional changes (for example, curing shrinkage) due to post-curing do not occur can be advantageous from the viewpoint of suppressing optical distortion of the pressure-sensitive adhesive layer.

　粘弾性層Ｖ１の厚さは特に限定されず、例えば３μｍ以上とすることができ、５μｍ以上であることが好ましい。厚さ５μｍ以上の粘弾性層Ｖ１によると、良好な粘着特性が得られやすい。また、かかる厚さの粘弾性層Ｖ１は、被着体表面に存在し得る凹凸を吸収して該被着体に密着性よく接合させやすい。粘弾性層Ｖ１の厚さが５μｍ以上であることは、光干渉による色付きや色むらを防止する観点からも好ましい。いくつかの態様において、粘弾性層Ｖ１の厚さは、１０μｍ以上であってもよく、２０μｍ以上でもよく、３０μｍ以上でもよく、５０μｍ以上でもよく、７０μｍ以上または８５μｍ以上でもよい。また、いくつかの態様において、粘弾性層Ｖ１の厚さは、例えば３００μｍ以下であってよく、２５０μｍ以下でもよく、２００μｍ以下でもよく、１５０μｍ以下でもよく、１２０μｍ以下でもよい。粘弾性層Ｖ１の厚さが大きすぎないことは、層間シートの薄型化等の観点から有利となり得る。ここに開示される技術は、例えば、粘弾性層Ｖ１の厚さが３μｍ～２００μｍ（より好ましくは５μｍ～１００μｍ）の範囲となる態様で好ましく実施され得る。粘弾性層Ｖ１および粘弾性層Ｖ２を有する層間シートの場合、粘弾性層Ｖ２の厚さは、上記で例示した粘弾性層Ｖ１の厚さと同様の範囲から選択され得る。粘弾性層Ｖ１のと粘弾性層Ｖ２の厚さとは、同程度であってもよく、異なっていてもよい。粘着剤層からなる基材レス両面粘着シートの形態の層間シートでは、該粘着剤層の厚さが層間シートの厚さとなる。 The thickness of the viscoelastic layer V 1 is not particularly limited, and can be, for example, 3 μm or more, preferably 5 μm or more. According to the thickness 5μm or more viscoelastic layers V 1, good adhesion properties can be easily obtained. Further, the viscoelastic layer V 1 of the such thickness tends to bond with good adhesion to the adherend by absorbing irregularities that may be present in the adherend surfaces. It is preferable that the thickness of the viscoelastic layer V 1 is 5 μm or more from the viewpoint of preventing coloring and color unevenness due to light interference. In some embodiments, the thickness of the viscoelastic layer V 1 may be 10 μm or greater, 20 μm or greater, 30 μm or greater, 50 μm or greater, 70 μm or greater, or 85 μm or greater. Further, in some embodiments, the thickness of the viscoelastic layer V 1 was, may be for example 300μm or less, may be 250μm or less, it may be 200μm or less, may be 150μm or less, may be 120μm or less. The fact that the thickness of the viscoelastic layer V 1 is not too large can be advantageous from the viewpoint of reducing the thickness of the interlayer sheet. The technique disclosed herein can be preferably carried out, for example, in an embodiment in which the thickness of the viscoelastic layer V 1 is in the range of 3 μm to 200 μm (more preferably 5 μm to 100 μm). In the case of an interlayer sheet having a viscoelastic layer V 1 and a viscoelastic layer V 2 , the thickness of the viscoelastic layer V 2 can be selected from the same range as the thickness of the viscoelastic layer V 1 exemplified above. The thickness of the viscoelastic layer V 1 and the thickness of the viscoelastic layer V 2 may be about the same or different. In the interlayer sheet in the form of a base material-less double-sided pressure-sensitive adhesive sheet composed of a pressure-sensitive adhesive layer, the thickness of the pressure-sensitive adhesive layer is the thickness of the interlayer sheet.

　粘着剤層Ｖ１と粘着剤層Ｖ２とが積層された構成の粘着剤層は、例えば、剥離性表面（例えば、剥離ライナーの剥離面）上に粘着剤層Ｖ１、Ｖ２をそれぞれ形成し、それらの粘着面同士を貼り合わせる方法や、粘着剤層Ｖ２を形成するための粘着剤組成物を粘着剤層Ｖ１の上に塗布して硬化させる方法、逆に粘着剤層Ｖ１を形成するための粘着剤組成物を粘着剤層Ｖ２の上に塗布して硬化させる方法、等を採用することができるが、これらに限定されない。あらかじめ形成した粘着剤層Ｖ１、Ｖ２の粘着面同士を貼り合わせる場合、必要に応じて、両粘着剤層の密着を促進する処理を行ってもよい。例えば、オートクレーブ処理、ロールプレス処理等を行うことができるが、これらに限定されない。 The pressure-sensitive adhesive layer having the structure in which the pressure-sensitive adhesive layer V 1 and the pressure-sensitive adhesive layer V 2 are laminated forms, for example, the pressure-sensitive adhesive layers V 1 and V 2 on a peelable surface (for example, the peeling surface of a peeling liner), respectively. Then, a method of adhering the adhesive surfaces to each other, a method of applying an adhesive composition for forming the adhesive layer V 2 on the adhesive layer V 1 and curing the adhesive layer V 1, and conversely, a method of applying the adhesive composition to the adhesive layer V 1 and curing the adhesive layer V 1. the method of curing the pressure-sensitive adhesive composition for forming by coating on the adhesive layer V 2 a, can be adopted, and the like. When the pressure-sensitive adhesive surfaces of the pressure-sensitive adhesive layers V 1 and V 2 formed in advance are bonded to each other, a treatment for promoting the adhesion between the pressure-sensitive adhesive layers may be performed, if necessary. For example, an autoclave process, a roll press process, and the like can be performed, but the present invention is not limited thereto.

＜支持基材＞
　いくつかの態様に係る層間シート（粘着シート）は、支持基材の片面または両面に粘着剤層を備える基材付き粘着シートの形態であり得る。支持基材の材質は特に限定されず、粘着シートの使用目的や使用態様等に応じて適宜選択することができる。使用し得る基材の非限定的な例として、ポリプロピレン（ＰＰ）やエチレン－プロピレン共重合体等のポリオレフィンを主成分とするポリオレフィンフィルム、ポリエチレンテレフタレート（ＰＥＴ）、ポリブチレンテレフタレート（ＰＢＴ）、ポリエチレンナフタレート（ＰＥＮ）等のポリエステルを主成分とするポリエステルフィルム、ポリ塩化ビニルを主成分とするポリ塩化ビニルフィルム等のプラスチックフィルム；ポリウレタンフォーム、ポリエチレン（ＰＥ）フォーム、ポリクロロプレンフォーム等の発泡体からなる発泡体シート；各種の繊維状物質（麻、綿等の天然繊維、ポリエステル、ビニロン等の合成繊維、アセテート等の半合成繊維、等であり得る。）の単独または混紡等による織布および不織布；和紙、上質紙、クラフト紙、クレープ紙等の紙類；アルミニウム箔、銅箔等の金属箔；等が挙げられる。これらを複合した構成の基材であってもよい。このような複合基材の例として、例えば、金属箔と上記プラスチックフィルムとが積層した構造の基材、ガラスクロス等の無機繊維で強化されたプラスチック基材等が挙げられる。 <Supporting base material>
The interlayer sheet (adhesive sheet) according to some aspects may be in the form of a pressure-sensitive adhesive sheet with a base material having an pressure-sensitive adhesive layer on one side or both sides of the support base material. The material of the supporting base material is not particularly limited, and can be appropriately selected depending on the purpose of use, the mode of use, and the like of the adhesive sheet. Non-limiting examples of base materials that can be used include polyester films containing polyester as a main component such as polypropylene (PP) and ethylene-propylene copolymer, polyethylene terephthalate (PET), polybutylene terephthalate (PBT), and polyethylene na. Polyester film containing polyester as the main component such as phthalate (PEN), plastic film such as polyvinyl chloride film containing polyvinyl chloride as the main component; foams such as polyurethane foam, polyethylene (PE) foam, and polychloroprene foam. Foam sheet; woven fabrics and non-woven fabrics made of various fibrous substances (natural fibers such as hemp and cotton, synthetic fibers such as polyester and vinylon, semi-synthetic fibers such as acetate, etc.) alone or in a blended manner; Papers such as Japanese paper, high-quality paper, kraft paper, and crepe paper; metal foils such as aluminum foil and copper foil; and the like can be mentioned. A base material having a composite structure of these may be used. Examples of such a composite base material include a base material having a structure in which a metal foil and the plastic film are laminated, a plastic base material reinforced with an inorganic fiber such as glass cloth, and the like.

　いくつかの態様において、各種のフィルム基材を好ましく用いることができる。上記フィルム基材は、発泡体フィルムや不織布シート等のように多孔質の基材であってもよく、非多孔質の基材であってもよく、多孔質の層と非多孔質の層とが積層した構造の基材であってもよい。いくつかの態様において、上記フィルム基材としては、独立して形状維持可能な（自立型の、あるいは非依存性の）樹脂フィルムをベースフィルムとして含むものを好ましく用いることができる。ここで「樹脂フィルム」とは、非多孔質の構造であって、典型的には実質的に気泡を含まない（ボイドレスの）樹脂フィルムを意味する。したがって、上記樹脂フィルムは、発泡体フィルムや不織布とは区別される概念である。上記樹脂フィルムとしては、独立して形状維持可能な（自立型の、あるいは非依存性の）ものが好ましく用いられ得る。上記樹脂フィルムは、単層構造であってもよく、２層以上の多層構造（例えば、３層構造）であってもよい。 In some embodiments, various film substrates can be preferably used. The film base material may be a porous base material such as a foam film or a non-woven fabric sheet, or may be a non-porous base material, and may be a porous layer and a non-porous layer. May be a base material having a laminated structure. In some embodiments, as the film base material, those containing an independently shape-maintainable (self-supporting or independent) resin film as a base film can be preferably used. Here, the "resin film" means a resin film (of voidless) having a non-porous structure and typically containing substantially no bubbles. Therefore, the resin film is a concept that is distinguished from foam films and non-woven fabrics. As the resin film, one that can independently maintain its shape (self-supporting or independent) can be preferably used. The resin film may have a single-layer structure or a multi-layer structure having two or more layers (for example, a three-layer structure).

　樹脂フィルムを構成する材料としては、例えば、ポリエチレンテレフタレート（ＰＥＴ）、ポリブチレンテレフタレート（ＰＢＴ）、ポリエチレンナフタレート（ＰＥＮ）等のポリエステルを主成分とするポリエステル系樹脂、ポリエチレン（ＰＥ）、ポリプロピレン（ＰＰ）、エチレン－プロピレン共重合体、エチレン－ブテン共重合体等のポリオレフィンを主成分とするポリオレフィン系樹脂、トリアセチルセルロース等のセルロース樹脂、アセテート系樹脂、ポリスルホン系樹脂、ポリエーテルスルホン系樹脂、ポリカーボネート系樹脂、ナイロン６、ナイロン６６、部分芳香族ポリアミド等のポリアミド（ＰＡ）系樹脂、ポリイミド（ＰＩ）系樹脂、透明ポリイミド樹脂、ポリアミドイミド（ＰＡＩ）、ポリエーテルエーテルケトン（ＰＥＥＫ）、ポリエーテルスルホン（ＰＥＳ）、ノルボルネン系樹脂等の環状ポリオレフィン樹脂、（メタ）アクリル系樹脂、ポリ塩化ビニル系樹脂、ポリ塩化ビニリデン系樹脂、ポリスチレン系樹脂、ポリビニルアルコール系樹脂、エチレン－酢酸ビニル共重合体樹脂、エチレン－ビニルアルコール共重合体樹脂、ポリアリレート系樹脂、ポリフェニレンサルファイド（ＰＰＳ）系樹脂、ポリウレタン（ＰＵ）、エチレン－酢酸ビニル共重合体（ＥＶＡ）、ポリテトラフルオロエチレン（ＰＴＦＥ）やフッ素化ポリイミド等のフッ素系樹脂、等が挙げられる。 Examples of the material constituting the resin film include a polyester-based resin containing a polyester as a main component, such as polyethylene terephthalate (PET), polybutylene terephthalate (PBT), and polyethylene naphthalate (PEN), polyethylene (PE), and polypropylene (PP). ), Polyimide-propylene copolymer, polyolefin-based resin such as ethylene-butene copolymer, cellulose resin such as triacetyl cellulose, acetate resin, polysulfone resin, polyethersulfone resin, polycarbonate Polyaceous resins, nylon 6, nylon 66, polyamide (PA) resins such as partially aromatic polyamide, polyimide (PI) resins, transparent polyimide resins, polyamideimide (PAI), polyether ether ketone (PEEK), polyether sulfone (PES), cyclic polyolefin resin such as norbornene resin, (meth) acrylic resin, polyvinyl chloride resin, polyvinylidene chloride resin, polystyrene resin, polyvinyl alcohol resin, ethylene-vinyl acetate copolymer resin, Ethylene-vinyl alcohol copolymer resin, polyallylate resin, polyphenylene sulfide (PPS) resin, polyurethane (PU), ethylene-vinyl acetate copolymer (EVA), polytetrafluoroethylene (PTFE), fluorinated polyimide, etc. Fluororesin, etc.

　上記樹脂フィルムは、このような樹脂の１種を単独で含む樹脂材料を用いて形成されたものであってもよく、２種以上がブレンドされた樹脂材料を用いて形成されたものであってもよい。上記樹脂フィルムは、無延伸であってもよく、延伸（例えば一軸延伸または二軸延伸）されたものであってもよい。例えば、ＰＥＴフィルム、ＰＢＴフィルム、ＰＥＮフィルム、無延伸ポリプロピレン（ＣＰＰ）フィルム、二軸延伸ポリプロピレン（ＯＰＰ）フィルム、低密度ポリエチレン（ＬＤＰＥ）フィルム、直鎖状低密度ポリエチレン（ＬＬＤＰＥ）フィルム、ＰＰ／ＰＥブレンドフィルム等が好ましく用いられ得る。強度や寸法安定性の観点から好ましい樹脂フィルムの例として、ＰＥＴフィルム、ＰＥＮフィルム、ＰＰＳフィルムおよびＰＥＥＫフィルムが挙げられる。入手容易性等の観点からＰＥＴフィルムおよびＰＰＳフィルムが特に好ましく、なかでもＰＥＴフィルムが好ましい。 The resin film may be formed by using a resin material containing one kind of such a resin alone, or may be formed by using a resin material in which two or more kinds are blended. May be good. The resin film may be unstretched or stretched (for example, uniaxially stretched or biaxially stretched). For example, PET film, PBT film, PEN film, unstretched polypropylene (CPP) film, biaxially stretched polypropylene (OPP) film, low density polyethylene (LDPE) film, linear low density polyethylene (LLDPE) film, PP / PE. A blended film or the like can be preferably used. Examples of preferable resin films from the viewpoint of strength and dimensional stability include PET film, PEN film, PPS film and PEEK film. From the viewpoint of availability, PET film and PPS film are particularly preferable, and PET film is particularly preferable.

　樹脂フィルムには、本発明の効果が著しく妨げられない範囲で、光安定剤、酸化防止剤、帯電防止剤、着色剤（染料、顔料等）、充填材、スリップ剤、アンチブロッキング剤等の公知の添加剤を、必要に応じて配合することができる。添加剤の配合量は特に限定されず、粘着シートの用途等に応じて適宜設定することができる。 Known resin films include light stabilizers, antioxidants, antistatic agents, colorants (dyees, pigments, etc.), fillers, slip agents, antiblocking agents, etc., as long as the effects of the present invention are not significantly impaired. Additives can be blended as needed. The blending amount of the additive is not particularly limited, and can be appropriately set according to the use of the pressure-sensitive adhesive sheet and the like.

　樹脂フィルムの製造方法は特に限定されない。例えば、押出成形、インフレーション成形、Ｔダイキャスト成形、カレンダーロール成形等の、従来公知の一般的な樹脂フィルム成形方法を適宜採用することができる。 The manufacturing method of the resin film is not particularly limited. For example, conventionally known general resin film molding methods such as extrusion molding, inflation molding, T-die casting molding, and calendar roll molding can be appropriately adopted.

　上記基材は、このようなベースフィルムから実質的に構成されたものであり得る。あるいは、上記基材は、上記ベースフィルムの他に、補助的な層を含むものであってもよい。上記補助的な層の例としては、光学特性調整層（例えば着色層、反射防止層）、基材に所望の外観を付与するための印刷層やラミネート層、帯電防止層、下塗り層、剥離層等の表面処理層が挙げられる。 The base material may be substantially composed of such a base film. Alternatively, the base material may include an auxiliary layer in addition to the base film. Examples of the auxiliary layer include an optical property adjusting layer (for example, a coloring layer and an antireflection layer), a printing layer or a laminating layer for imparting a desired appearance to a base material, an antistatic layer, an undercoat layer, and a peeling layer. Such as a surface treatment layer.

　いくつかの態様において、支持基材としては、光透過性を有する基材（以下、光透過性基材ともいう。）を好ましく採用し得る。これにより、光透過性を有する基材付き粘着シートを構成することが可能となる。光透過性基材の全光線透過率は、例えば５０％超であってよく、７０％以上であってもよい。いくつかの好ましい態様では、支持基材の全光線透過率は８０％以上であり、より好ましくは９０％以上であり、９５％以上（例えば９５～１００％）であってもよい。上記全光線透過率は、ＪＩＳ　Ｋ　７１３６：２０００に準拠して、市販の透過率計を使用して測定される。透過率計としては、村上色彩技術研究所製の商品名「ＨＡＺＥＭＥＴＥＲ　ＨＭ－１５０」またはその相当品が用いられる。上記光透過性基材の好適例として、光透過性を有する樹脂フィルムが挙げられる。上記光透過性基材は、光学フィルムであってもよい。 In some embodiments, a light-transmitting base material (hereinafter, also referred to as a light-transmitting base material) can be preferably adopted as the supporting base material. This makes it possible to construct an adhesive sheet with a base material having light transmission. The total light transmittance of the light-transmitting substrate may be, for example, more than 50%, and may be 70% or more. In some preferred embodiments, the total light transmittance of the supporting substrate is 80% or more, more preferably 90% or more, and may be 95% or more (for example, 95 to 100%). The total light transmittance is measured using a commercially available transmittance meter in accordance with JIS K 7136: 2000. As the transmittance meter, the product name "HAZEMETER HM-150" manufactured by Murakami Color Technology Research Institute or its equivalent is used. A preferable example of the light-transmitting base material is a resin film having light-transmitting property. The light-transmitting substrate may be an optical film.

　基材の厚さは、特に限定されず、層間シートの使用目的や使用態様等に応じて選択し得る。基材の厚さは、例えば５００μｍ以下であってよく、層間シートの取扱い性や加工性の観点から３００μｍ以下であることが好ましく、１５０μｍ以下でもよく、１００μｍ以下でもよく、５０μｍ以下でもよく、２５μｍ以下でもよく、１０μｍ以下でもよい。基材の厚さが小さくなると、被着体の表面形状への追従性が向上する傾向にある。また、取扱い性や加工性等の観点から、基材の厚さは、例えば２μｍ以上であってよく、１０μｍ以上でもよく、２５μｍ以上でもよい。 The thickness of the base material is not particularly limited and can be selected according to the purpose and mode of use of the interlayer sheet. The thickness of the base material may be, for example, 500 μm or less, preferably 300 μm or less from the viewpoint of handleability and processability of the interlayer sheet, 150 μm or less, 100 μm or less, 50 μm or less, and 25 μm. It may be less than or equal to 10 μm or less. As the thickness of the base material becomes smaller, the ability to follow the surface shape of the adherend tends to improve. Further, from the viewpoint of handleability, processability and the like, the thickness of the base material may be, for example, 2 μm or more, 10 μm or more, or 25 μm or more.

　基材のうち粘着剤層（粘弾性層）が積層される側の面には、必要に応じて、コロナ放電処理、プラズマ処理、紫外線照射処理、酸処理、アルカリ処理、下塗り剤（プライマー）の塗布による下塗り層の形成等の、従来公知の表面処理が施されていてもよい。このような表面処理は、粘着剤層の基材への投錨性を向上させるための処理であり得る。下塗り層の形成に用いるプライマーの組成は特に限定されず、公知のものから適宜選択することができる。下塗り層の厚さは特に制限されないが、通常、０．０１μｍ～１μｍ程度が適当であり、０．１μｍ～１μｍ程度が好ましい。必要に応じて基材に施され得る他の処理として、帯電防止層形成処理、着色層形成処理、印刷処理等が挙げられる。これらの処理は、単独でまたは組み合わせて適用することができる。 If necessary, corona discharge treatment, plasma treatment, ultraviolet irradiation treatment, acid treatment, alkali treatment, and undercoating agent (primer) may be applied to the surface of the base material on the side on which the pressure-sensitive adhesive layer (viscoelastic layer) is laminated. Conventionally known surface treatments such as formation of an undercoat layer by coating may be applied. Such a surface treatment may be a treatment for improving the anchoring property of the pressure-sensitive adhesive layer on the base material. The composition of the primer used for forming the undercoat layer is not particularly limited, and can be appropriately selected from known ones. The thickness of the undercoat layer is not particularly limited, but is usually about 0.01 μm to 1 μm, preferably about 0.1 μm to 1 μm. Other treatments that can be applied to the substrate as needed include antistatic layer forming treatments, colored layer forming treatments, printing treatments and the like. These treatments can be applied alone or in combination.

　ここに開示される層間シートが基材付き粘着シートの形態である場合、該層間シートの厚さは、例えば１０００μｍ以下であってよく、３５０μｍ以下でもよく、２００μｍ以下でもよく、１２０μｍ以下でもよく、７５μｍ以下でもよく、５０μｍ以下でもよい。また、層間シートの厚さは、取扱い性等の観点から、例えば１０μｍ以上であってよく、２５μｍ以上でもよく、８０μｍ以上でもよく、１３０μｍ以上でもよい。
　なお、層間シートの厚さとは、被着体に貼り付けられる部分の厚さをいう。例えば図１に示す構成の層間シート１では、粘着剤層の第１の表面（粘着面）１０Ａから支持基材の第２面２０Ｂまでの厚さを指し、剥離ライナー３０の厚さは含まない。 When the interlayer sheet disclosed herein is in the form of an adhesive sheet with a base material, the thickness of the interlayer sheet may be, for example, 1000 μm or less, 350 μm or less, 200 μm or less, 120 μm or less. It may be 75 μm or less, or 50 μm or less. Further, the thickness of the interlayer sheet may be, for example, 10 μm or more, 25 μm or more, 80 μm or more, or 130 μm or more from the viewpoint of handleability and the like.
The thickness of the interlayer sheet means the thickness of the portion to be attached to the adherend. For example, in the interlayer sheet 1 having the configuration shown in FIG. 1, it refers to the thickness from the first surface (adhesive surface) 10A of the pressure-sensitive adhesive layer to the second surface 20B of the supporting base material, and does not include the thickness of the release liner 30. ..

＜剥離ライナー付き層間シート＞
　ここに開示される層間シート（粘着シート）は、粘着剤層の表面（粘着面）を剥離ライナーの剥離面に当接させた粘着製品の形態をとり得る。したがって、この明細書により、ここに開示されるいずれかの層間シートと、該層間シートの粘着面に当接する剥離面を有する剥離ライナーと、を含む剥離ライナー付き層間シート（粘着製品）が提供される。 <Interlayer sheet with release liner>
The interlayer sheet (adhesive sheet) disclosed herein may take the form of an adhesive product in which the surface (adhesive surface) of the adhesive layer is brought into contact with the release surface of the release liner. Therefore, the present specification provides an interlayer sheet (adhesive product) with a release liner including any of the interlayer sheets disclosed herein and a release liner having a release surface that abuts on the adhesive surface of the interlayer sheet. NS.

　剥離ライナーとしては、特に限定されず、例えば、樹脂フィルムや紙（ポリエチレン等の樹脂がラミネートされた紙であり得る。）等の剥離ライナー基材上に剥離処理層を有する剥離ライナーや、フッ素系ポリマー（ポリテトラフルオロエチレン等）やポリオレフィン系樹脂（ポリエチレン、ポリプロピレン等）のような低接着性材料により形成された樹脂フィルムからなる剥離ライナー等を用いることができる。上記剥離処理層は、剥離ライナー基材を剥離処理剤により表面処理して形成されたものであり得る。剥離処理剤は、シリコーン系剥離処理剤、長鎖アルキル系剥離処理剤、フッ素系剥離処理剤、硫化モリブデン（ＩＶ）等の公知の剥離処理剤であり得る。いくつかの態様において、シリコーン系剥離処理剤による剥離処理層を有する剥離ライナーを好ましく採用し得る。剥離処理層の厚さや形成方法は特に限定されず、剥離ライナーの粘着面側表面において適切な剥離性が発揮されるように設定することができる。 The release liner is not particularly limited, and for example, a release liner having a release treatment layer on a release liner base material such as a resin film or paper (paper in which a resin such as polyethylene is laminated) or a fluorine-based release liner. A release liner made of a resin film formed of a low adhesive material such as a polymer (polytetrafluoroethylene or the like) or a polyolefin resin (polyethylene, polypropylene, etc.) can be used. The peeling treatment layer may be formed by surface-treating the peeling liner base material with a peeling treatment agent. The stripping agent may be a known stripping agent such as a silicone-based stripping agent, a long-chain alkyl-based stripping agent, a fluorine-based stripping agent, or molybdenum sulfide (IV). In some embodiments, a release liner having a release treatment layer with a silicone-based release treatment agent can be preferably adopted. The thickness and forming method of the peeling treatment layer are not particularly limited, and can be set so that appropriate peeling property is exhibited on the adhesive surface side surface of the peeling liner.

　いくつかの態様において、粘着面の平滑性等の観点から、剥離ライナー基材としての樹脂フィルム（以下、剥離フィルム基材ともいう。）上に剥離処理層を有する構成の剥離ライナー（以下、剥離フィルムともいう。）を好ましく採用し得る。剥離フィルム基材としては、各種のプラスチックフィルムを用いることができる。この明細書においてプラスチックフィルムとは、典型的には非多孔質のシートであって、例えば不織布とは区別される（すなわち、不織布を含まない）概念である。 In some embodiments, from the viewpoint of smoothness of the adhesive surface and the like, a release liner having a release treatment layer on a resin film (hereinafter, also referred to as a release film base material) as a release liner base material (hereinafter, peeling). (Also referred to as a film) can be preferably adopted. Various plastic films can be used as the release film base material. As used herein, a plastic film is typically a non-porous sheet, a concept that distinguishes it from, for example, non-woven fabrics (ie, does not include non-woven fabrics).

　上記プラスチックフィルムの材料としては、例えば、ポリエチレンテレフタレート（ＰＥＴ）、ポリブチレンテレフタレート（ＰＢＴ）、ポリエチレンナフタレート（ＰＥＮ）等のポリエステル系樹脂、ポリエチレン（ＰＥ）、ポリプロピレン（ＰＰ）、エチレン－プロピレン共重合体、エチレン－ブテン共重合体等のポリオレフィン系樹脂、トリアセチルセルロース等のセルロース樹脂、アセテート系樹脂、ポリスルホン系樹脂、ポリエーテルスルホン系樹脂、ポリカーボネート系樹脂、ポリアミド系樹脂、ポリイミド系樹脂、ノルボルネン系樹脂等の環状ポリオレフィン樹脂、（メタ）アクリル系樹脂、ポリ塩化ビニル系樹脂、ポリ塩化ビニリデン系樹脂、ポリスチレン系樹脂、ポリビニルアルコール系樹脂、エチレン－酢酸ビニル共重合体樹脂、エチレン－ビニルアルコール共重合体樹脂、ポリアリレート系樹脂、ポリフェニレンサルファイド系樹脂等が挙げられる。これらの樹脂のいずれか１種または２種以上の混合物から形成された剥離フィルム基材を用いることができる。なかでも好ましい剥離フィルム基材として、ポリエステル系樹脂から形成されたポリエステル系樹脂フィルム（例えばＰＥＴフィルム）が挙げられる。 Examples of the material of the plastic film include polyester resins such as polyethylene terephthalate (PET), polybutylene terephthalate (PBT), and polyethylene naphthalate (PEN), polyethylene (PE), polypropylene (PP), and ethylene-propylene co-weight. Combined, polyolefin resin such as ethylene-butene copolymer, cellulose resin such as triacetyl cellulose, acetate resin, polysulfone resin, polyether sulfone resin, polycarbonate resin, polyamide resin, polyimide resin, norbornene resin Cyclic polyolefin resin such as resin, (meth) acrylic resin, polyvinyl chloride resin, polyvinylidene chloride resin, polystyrene resin, polyvinyl alcohol resin, ethylene-vinyl acetate copolymer resin, ethylene-vinyl alcohol co-weight Examples thereof include a coalesced resin, a polyarylate resin, and a polyphenylene sulfide resin. A release film base material formed from any one or a mixture of two or more of these resins can be used. Among them, a preferable release film base material includes a polyester-based resin film (for example, PET film) formed from a polyester-based resin.

　上述した剥離フィルム基材として用いられるプラスチックフィルムは、無延伸フィルム、一軸延伸フィルム、二軸延伸フィルムのいずれであってもよい。また、上記プラスチックフィルムは、単層構造であってもよく、２層以上のサブ層を含む多層構造であってもよい。上記プラスチックフィルムには、酸化防止剤、老化防止剤、耐熱安定剤、光安定剤、紫外線吸収剤、顔料や染料等の着色剤、滑剤、充填剤、帯電防止剤、核剤等の、粘着シートの剥離フィルム基材に用いられ得る公知の添加剤が配合されていてもよい。多層構造のプラスチックフィルムにおいて、各添加剤は、すべてのサブ層に配合されていてもよく、一部のサブ層にのみ配合されていてもよい。 The plastic film used as the above-mentioned release film base material may be any of a non-stretched film, a uniaxially stretched film, and a biaxially stretched film. Further, the plastic film may have a single-layer structure or a multi-layer structure including two or more sub-layers. The plastic film is an adhesive sheet containing antioxidants, antioxidants, heat stabilizers, light stabilizers, ultraviolet absorbers, colorants such as pigments and dyes, lubricants, fillers, antioxidants, nucleating agents, etc. A known additive that can be used for the release film base material of the above may be blended. In the multi-layered plastic film, each additive may be blended in all sublayers or only in some sublayers.

　いくつかの好ましい態様では、上記剥離フィルム基材（典型的にはプラスチックフィルム）として、その剥離面側の層において無機粒子等の粒子（例えば顔料や滑剤、充填剤等であり得る。）の含有量が制限されているか、あるいはそのような粒子を実質的に含まないものが好ましく用いられ得る。ここで実質的に含まないとは、当該層中の粒子（例えば無機粒子）の量が１重量％未満であることをいい、好ましくは０．１重量％未満（例えば０～０．０１重量％）であることをいう。そのような剥離フィルム基材を備える剥離フィルムは、剥離面の算術平均粗さＲａや最大高さＲｚが低いものとなりやすい。上記剥離フィルム基材（典型的にはプラスチックフィルム）が多層構造を有する場合には、剥離面側の層中の粒子含有量は、当該剥離面側層以外の層中の粒子含有量の１／１０以下（例えば１／５０以下）であり得る。 In some preferred embodiments, the release film substrate (typically a plastic film) contains particles such as inorganic particles (eg, pigments, lubricants, fillers, etc.) in the layer on the release surface side thereof. Those with a limited amount or substantially free of such particles may be preferably used. Here, substantially not contained means that the amount of particles (for example, inorganic particles) in the layer is less than 1% by weight, preferably less than 0.1% by weight (for example, 0 to 0.01% by weight). ). A release film provided with such a release film base material tends to have a low arithmetic mean roughness Ra and maximum height Rz of the release surface. When the release film base material (typically a plastic film) has a multilayer structure, the particle content in the layer on the release surface side is 1 / of the particle content in the layers other than the release surface side layer. It can be 10 or less (for example, 1/50 or less).

　第１粘着面および第２粘着面上にそれぞれ剥離ライナーを有する形態の剥離ライナー付き層間シートにおいて、一方の粘着面上に配置される剥離ライナー（以下、一方の剥離ライナーともいう。）と、他方の粘着面上に配置される剥離ライナー（以下、他方の剥離ライナーともいう。）とは、同種の材料および構成を有するものであってもよく、異なる材料、構成を有するものであってもよい。 In an interlayer sheet with a release liner having a release liner on each of the first adhesive surface and the second adhesive surface, a release liner (hereinafter, also referred to as one release liner) arranged on one adhesive surface and the other. The release liner (hereinafter, also referred to as the other release liner) arranged on the adhesive surface of the above may have the same material and composition, or may have a different material and composition. ..

　剥離ライナー（好ましくは剥離フィルム）の厚さは特に限定されず、例えば１０μｍ～５００μｍ程度であり得る。剥離ライナーの強度や寸法安定性の観点から、剥離ライナーの厚さは、２０μｍ以上であることが適当であり、３０μｍ以上であることが好ましく、３５μｍ以上でもよく、４０μｍ以上でもよく、４５μｍ以上でもよい。また、剥離ライナーの取扱い性（例えば、巻回しやすさ）等の観点から、剥離ライナーの厚さは、３００μｍ以下であることが適当であり、２５０μｍ以下であることが好ましく、２００μｍ以下でもよく、１５０μｍ以下でもよく、１３０μｍ以下でもよい。いくつかの好ましい態様では、剥離ライナーの厚さは凡そ１２５μｍ以下であり、凡そ１１５μｍ以下であってもよく、凡そ１０５μｍ以下でもよく、凡そ９０μｍ以下でもよく、凡そ７０μｍ以下でもよい。剥離ライナーの厚さを所定値以下とすることで、ロール状にした際の巻き跡がつきづらくなり、粘着シートからの除去がスムーズとなり、剥離ライナー除去後の粘着面において高い表面平滑性が得られやすい。 The thickness of the release liner (preferably the release film) is not particularly limited, and may be, for example, about 10 μm to 500 μm. From the viewpoint of the strength and dimensional stability of the release liner, the thickness of the release liner is preferably 20 μm or more, preferably 30 μm or more, 35 μm or more, 40 μm or more, or 45 μm or more. good. Further, from the viewpoint of handleability of the release liner (for example, ease of winding), the thickness of the release liner is preferably 300 μm or less, preferably 250 μm or less, and may be 200 μm or less. It may be 150 μm or less, or 130 μm or less. In some preferred embodiments, the thickness of the release liner is approximately 125 μm or less, may be approximately 115 μm or less, may be approximately 105 μm or less, may be approximately 90 μm or less, and may be approximately 70 μm or less. By setting the thickness of the release liner to a predetermined value or less, it becomes difficult to make winding marks when the product is rolled, the removal from the adhesive sheet becomes smooth, and high surface smoothness is obtained on the adhesive surface after the release liner is removed. Easy to get rid of.

　一方の剥離ライナーおよび他方の剥離ライナーを備える態様の剥離ライナー付き層間シートにおいて、それらの剥離ライナーの厚さは、同じであってもよく、異なっていてもよい。いくつかの態様では、剥離作業性等の観点から、一方の剥離ライナーと他方の剥離ライナーとが異なる厚さを有することが好ましく、例えば、より厚い方の剥離ライナーの厚さが、より薄い方の剥離ライナーの厚さの凡そ１．１倍以上（例えば凡そ１．２５倍以上。上限は特に制限されないが、例えば５倍以下）であることが好ましい。 In the interlayer sheet with a release liner in the embodiment including one release liner and the other release liner, the thicknesses of the release liners may be the same or different. In some aspects, from the viewpoint of peeling workability and the like, it is preferable that one peeling liner and the other peeling liner have different thicknesses, for example, the thicker peeling liner has a thinner thickness. The thickness of the release liner is preferably about 1.1 times or more (for example, about 1.25 times or more. The upper limit is not particularly limited, but for example, 5 times or less).

　（粘着面側表面の算術平均粗さＲａ）
　いくつかの態様において、剥離ライナー（好ましくは剥離フィルム）は、粘着面側表面の算術平均粗さＲａが所定値以下（例えば凡そ１００ｎｍ以下、さらには５０ｎｍ未満）に制限されていることが、高い表面平滑性を有する粘着面を実現する観点から好ましい。いくつかの態様では、剥離ライナーの粘着面側表面の算術平均粗さＲａは、例えば凡そ３０ｎｍ以下であることが好ましく、凡そ２５ｎｍ以下であることがより好ましく、凡そ２０ｎｍ以下でもよく、凡そ１８ｎｍ以下でもよい。また、剥離ライナーの製造容易性や取扱い性等の観点から、いくつかの態様において、上記算術平均粗さＲａは、例えば凡そ５ｎｍ以上であってよく、凡そ１０ｎｍ以上でもよく、凡そ１５ｎｍ以上でもよい。第１粘着面および第２粘着面上にそれぞれ剥離ライナーが配置された形態の剥離ライナー付き層間シートでは、両剥離ライナーの粘着面側表面がいずれも上述したいずれかの算術平均粗さＲａを満たすことが好ましい。両剥離ライナーの粘着面側表面の算術平均粗さＲａは、同程度であってもよく、異なっていてもよい。 (Arithmetic Mean Roughness Ra on the surface on the adhesive surface side)
In some embodiments, the release liner (preferably the release film) is often limited in that the arithmetic mean roughness Ra of the surface on the adhesive surface side is limited to a predetermined value or less (for example, about 100 nm or less, further less than 50 nm). It is preferable from the viewpoint of realizing an adhesive surface having surface smoothness. In some embodiments, the arithmetic mean roughness Ra of the adhesive surface side surface of the release liner is, for example, preferably about 30 nm or less, more preferably about 25 nm or less, about 20 nm or less, and about 18 nm or less. It may be. Further, from the viewpoint of ease of manufacture and handleability of the release liner, in some embodiments, the arithmetic mean roughness Ra may be, for example, about 5 nm or more, about 10 nm or more, or about 15 nm or more. .. In the interlayer sheet with a release liner in which the release liner is arranged on the first adhesive surface and the second adhesive surface, both the adhesive surface side surfaces of both release liners satisfy any of the above-mentioned arithmetic mean roughness Ra. Is preferable. The arithmetic mean roughness Ra of the adhesive surface side surfaces of both release liners may be about the same or different.

　（粘着面側表面の最大高さＲｚ）
　いくつかの態様において、剥離ライナー（好ましくは剥離フィルム）は、粘着面側表面の最大高さＲｚが７００ｎｍ以下であることが、高い表面平滑性を有する粘着面を実現する観点から好ましい。いくつかの態様では、剥離ライナーの粘着面側表面の最大高さＲｚは、好ましくは凡そ６００ｎｍ以下であり、凡そ５００ｎｍ以下でもよく、凡そ４００ｎｍ以下でもよく、凡そ３００ｎｍ以下でもよい。また、剥離ライナーの製造容易性や取扱い性等の観点から、いくつかの態様において、上記最大高さＲｚは、例えば凡そ５０ｎｍ以上であってよく、凡そ８０ｎｍ以上でもよく、凡そ１００ｎｍ以上でもよく、凡そ２００ｎｍ以上でもよく、凡そ３００ｎｍ以上でもよい。第１粘着面および第２粘着面上にそれぞれ剥離ライナーが配置された形態の剥離ライナー付き層間シートでは、両剥離ライナーの粘着面側表面がいずれも上述したいずれかの最大高さＲｚを満たすことが好ましい。両剥離ライナーの粘着面側表面の最大高さＲｚは、同程度であってもよく、異なっていてもよい。 (Maximum height Rz of the surface on the adhesive surface side)
In some embodiments, the release liner (preferably a release film) preferably has a maximum height Rz of the surface on the adhesive surface side of 700 nm or less from the viewpoint of realizing an adhesive surface having high surface smoothness. In some embodiments, the maximum height Rz of the adhesive surface side surface of the release liner is preferably about 600 nm or less, may be about 500 nm or less, may be about 400 nm or less, and may be about 300 nm or less. Further, from the viewpoint of ease of manufacture and handleability of the release liner, in some embodiments, the maximum height Rz may be, for example, about 50 nm or more, about 80 nm or more, or about 100 nm or more. It may be about 200 nm or more, and may be about 300 nm or more. In the interlayer sheet with a release liner in which the release liner is arranged on the first adhesive surface and the second adhesive surface, the adhesive surface side surfaces of both release liners satisfy any of the above-mentioned maximum heights Rz. Is preferable. The maximum height Rz of the adhesive surface side surfaces of both release liners may be about the same or different.

　（背面の表面性状）
　剥離ライナー（好ましくは剥離フィルム）の背面（粘着剤層側の反対面）の算術平均粗さＲａや最大高さＲｚは特に限定されない。剥離ライナーの背面の算術平均粗さＲａは、生産性等の観点から、例えば３０ｎｍ超（例えば３５ｎｍ超、さらには凡そ５０ｎｍ以上）であってもよい。剥離ライナーの背面の最大高さＲｚは、生産性等の観点から、例えば４００ｎｍ超（例えば凡そ５００ｎｍ以上）であってもよく、８００ｎｍ超（例えば１０００ｎｍ以上）でもよい。 (Surface texture on the back)
The arithmetic mean roughness Ra and the maximum height Rz of the back surface (opposite surface of the adhesive layer side) of the release liner (preferably the release film) are not particularly limited. The arithmetic mean roughness Ra on the back surface of the peeling liner may be, for example, more than 30 nm (for example, more than 35 nm, more preferably about 50 nm or more) from the viewpoint of productivity and the like. The maximum height Rz of the back surface of the release liner may be, for example, more than 400 nm (for example, about 500 nm or more) or more than 800 nm (for example, 1000 nm or more) from the viewpoint of productivity and the like.

　剥離フィルム表面の算術平均粗さＲａおよび最大高さＲｚは、フィルム材料の選択や成形方法、剥離処理等の表面処理等によって調節され得る。例えば、剥離性表面を構成する層（アンチブロッキング層、ハードコート層、オリゴマー防止層等）の平滑性の調節、当該表面層や剥離フィルム基材中のフィラー粒子の減量や不使用（無粒子化）、その他、延伸条件の調整等が挙げられる。 The arithmetic mean roughness Ra and the maximum height Rz of the peeled film surface can be adjusted by the selection of the film material, the molding method, the surface treatment such as the peeling treatment, and the like. For example, adjusting the smoothness of the layers constituting the peelable surface (anti-blocking layer, hard coat layer, oligomer prevention layer, etc.), reducing the amount of filler particles in the surface layer or the release film base material, or eliminating the use (particle-free). ), In addition, adjustment of stretching conditions and the like can be mentioned.

　剥離ライナー（好ましくは剥離フィルム）表面の算術平均粗さＲａおよび最大高さＲｚは、非接触式の表面粗さ測定装置を用いて測定される。非接触式の表面粗さ測定装置としては、光干渉方式の表面粗さ測定装置が用いられ、例えば３次元光学プロファイラー（商品名「ＮｅｗＶｉｅｗ７３００」、ＺＹＧＯ社製）またはその相当品を使用することができる。例えば、剥離ライナーの測定面とは反対側の面に、ガラス板（ＭＡＴＳＵＮＡＭＩ社製のソーダライムガラス板、厚さ１．３ｍｍ）を粘着剤で貼り合わせて固定し、２３℃、５０％ＲＨの環境下において、３次元光学プロファイラー（商品名「ＮｅｗＶｉｅｗ７３００」、ＺＹＧＯ社製）を用いて表面形状を測定することができる。 The arithmetic mean roughness Ra and the maximum height Rz of the surface of the release liner (preferably the release film) are measured using a non-contact type surface roughness measuring device. As the non-contact type surface roughness measuring device, a light interference type surface roughness measuring device is used, and for example, a three-dimensional optical profiler (trade name "NewView7300", manufactured by ZYGO) or an equivalent product thereof can be used. can. For example, a glass plate (soda lime glass plate manufactured by MATSUNAMI, thickness 1.3 mm) is attached and fixed with an adhesive on the surface opposite to the measurement surface of the release liner, and fixed at 23 ° C. and 50% RH. In an environment, the surface shape can be measured using a three-dimensional optical profiler (trade name "NewView7300", manufactured by ZYGO).

＜用途＞
　ここに開示される層間シートは、各種の被着体に貼り合わせて用いられ得る。上記被着体の構成材料（被着体材料）としては、特に限定されるものではないが、例えば、銅、銀、金、鉄、錫、パラジウム、アルミニウム、ニッケル、チタン、クロム、インジウム、亜鉛等、またはこれらの２種以上を含む合金等の金属材料や、例えばポリイミド系樹脂、アクリル系樹脂、ポリエーテルニトリル系樹脂、ポリエーテルスルホン系樹脂、ポリエステル系樹脂（ＰＥＴ系樹脂、ポリエチレンナフタレート系樹脂等）、ポリ塩化ビニル系樹脂、ポリフェニレンサルファイド系樹脂、ポリエーテルエーテルケトン系樹脂、ポリアミド系樹脂（いわゆるアラミド樹脂等）、ポリアリレート系樹脂、フッ素系樹脂、ポリカーボネート系樹脂、ジアセチルセルロースやトリアセチルセルロース等のセルロース系ポリマー、ビニルブチラール系ポリマー、液晶ポリマー、グラフェン等のカーボン材料等の各種樹脂材料（典型的にはプラスチック材）、アルミナ、ジルコニア、チタニア、ＳｉＯ２、ＩＴＯ（酸化インジウムスズ）、ＡＴＯ（アンチモンドープ酸化スズ）等の金属酸化物及びその混合物、窒化アルミニウム、窒化ケイ素、窒化チタン、窒化ガリウム、窒化インジウム等の窒化物及びその複合物、アルカリガラス、無アルカリガラス、石英ガラス、ホウケイ酸ガラス、サファイアガラス等の無機材料等が挙げられる。ここに開示される層間シートは、少なくとも表面が上記材料から構成された部材（例えば光学部材）に貼り付けられて用いられ得る。 <Use>
The interlayer sheet disclosed herein can be used by being bonded to various adherends. The constituent material (adhesion material) of the adherend is not particularly limited, but for example, copper, silver, gold, iron, tin, palladium, aluminum, nickel, titanium, chromium, indium, and zinc. Etc., or metal materials such as alloys containing two or more of these, for example, polyimide-based resin, acrylic-based resin, polyether nitrile-based resin, polyether sulfone-based resin, polyester-based resin (PET-based resin, polyethylene naphthalate-based). Resins, etc.), Polyvinyl chloride resins, polyphenylene sulfide resins, polyether ether ketone resins, polyamide resins (so-called aramid resins, etc.), polyarylate resins, fluorine resins, polycarbonate resins, diacetyl celluloses and triacetyls. Various resin materials (typically plastic materials) such as cellulose-based polymers such as cellulose, vinyl butyral polymers, liquid crystal polymers, and carbon materials such as graphene, alumina, zirconia, titania, SiO 2 , ITO (indium tin oxide), Metal oxides such as ATO (antimonated tin oxide) and their mixtures, nitrides such as aluminum nitride, silicon nitride, titanium nitride, gallium nitride, indium nitride and their composites, alkaline glass, non-alkali glass, quartz glass, hokei Examples thereof include inorganic materials such as acid glass and sapphire glass. The interlayer sheet disclosed herein can be used by being attached to a member (for example, an optical member) whose surface is at least composed of the above materials.

　ここに開示される層間シートは、被着体に貼り合わせた後、室温程度の温度域（例えば２０℃～３５℃）よりも高い温度に加熱する処理を必要としない貼付け態様で用いられ得る。また、層間シートの構成材料（例えば基材の材質）や被着体の種類に応じて許容される場合には、被着体への貼り合わせ後、貼り合わせの時点、および貼り合わせ前の、少なくともいずれかのタイミングで加熱処理を行ってもよい。加熱処理は、粘着剤の被着体への密着性向上や接着促進等の目的で行うことができる。加熱処理温度は、層間シートの構成材料や被着体の種類に応じて許容される範囲で、被着体の表面状態等を考慮して、所望の効果が得られるように適宜設定することができ、例えば１００℃程度またはそれ以下であってよく、８０℃以下でもよく、６０℃以下でもよく、５０℃以下でもよい。 The interlayer sheet disclosed here can be used in a bonding mode that does not require a treatment of heating to a temperature higher than a temperature range of about room temperature (for example, 20 ° C. to 35 ° C.) after being bonded to an adherend. Further, if it is permissible depending on the constituent material of the interlayer sheet (for example, the material of the base material) and the type of the adherend, after bonding to the adherend, at the time of bonding, and before bonding, The heat treatment may be performed at at least any timing. The heat treatment can be performed for the purpose of improving the adhesion of the pressure-sensitive adhesive to the adherend and promoting adhesion. The heat treatment temperature may be appropriately set within an allowable range according to the constituent materials of the interlayer sheet and the type of the adherend so as to obtain the desired effect in consideration of the surface condition of the adherend and the like. It can be, for example, about 100 ° C. or lower, 80 ° C. or lower, 60 ° C. or lower, or 50 ° C. or lower.

　層間シートの貼り付け対象または積層対象である部材や材料（両面粘着シートの形態の層間シートにおいては、少なくとも一方の被着体）は、光透過性を有するものであり得る。このような被着体では、ここに開示される層間シートが高透明性であることの利点が得られやすい。上記被着体の全光線透過率は、例えば５０％超であってよく、７０％以上でもよい。いくつかの好ましい態様では、上記被着体の全光線透過率は８０％以上であり、より好ましくは９０％以上であり、さらに好ましくは９５％以上（例えば９５～１００％）である。ここに開示される層間シートは、全光線透過率が所定値以上の被着体（例えば光学部材）に貼り付けまたは積層する態様で好ましく用いられ得る。上記全光線透過率は、ＪＩＳ　Ｋ　７１３６：２０００に準拠して、市販の透過率計を使用して測定される。透過率計としては、村上色彩技術研究所製の商品名「ＨＡＺＥＭＥＴＥＲ　ＨＭ－１５０」またはその相当品が用いられる。 The member or material to which the interlayer sheet is attached or laminated (at least one adherend in the interlayer sheet in the form of a double-sided adhesive sheet) may have light transmission. In such an adherend, it is easy to obtain the advantage that the interlayer sheet disclosed herein is highly transparent. The total light transmittance of the adherend may be, for example, more than 50%, and may be 70% or more. In some preferred embodiments, the total light transmittance of the adherend is 80% or more, more preferably 90% or more, still more preferably 95% or more (for example, 95 to 100%). The interlayer sheet disclosed herein can be preferably used in a mode of being attached or laminated on an adherend (for example, an optical member) having a total light transmittance of a predetermined value or more. The total light transmittance is measured using a commercially available transmittance meter in accordance with JIS K 7136: 2000. As the transmittance meter, the product name "HAZEMETER HM-150" manufactured by Murakami Color Technology Research Institute or its equivalent is used.

　被着体の屈折率と、該被着体に当接して配置される粘弾性層（例えば粘弾性層Ｖ１であり、粘弾性層Ｖ２を有する形態では該粘弾性層Ｖ２でもよい。）の屈折率とは、同程度であってもよく、異なっていてもよい。例えば、被着体の屈折率に対して粘弾性層（典型的には粘着剤層）の屈折率を相対的に高くすることにより、被着体側から粘着剤層に臨界角以下の角度で入射する光を正面側に屈折させ、正面輝度を高めることができる。この場合、被着体の屈折率は、例えば１．５５以下、１．５０以下、１．４８以下、１．４５以下であってよく、１．４５未満であってもよく、また、例えば１．１０以上、１．２０以上、１．３０以上または１．３５以上であり得る。また、粘着剤層に対して相対的に高屈折率の被着体によると、粘着剤層側から被着体に入射する光を正面側に屈折させ、正面輝度を高めることができる。この場合、被着体の屈折率は、例えば１．６０以上、１．６５以上または１．７０以上であってよく、また、例えば３．００以下であり、２．５０以下または２．００以下であり得る。一方、粘着剤層と被着体との屈折率差を小さくすることにより、界面での光反射を抑制することができる。この場合、被着体の屈折率は、１．５５～１．８０程度であってよく、１．５５～１．７５程度でもよく、１．６０～１．７０程度でもよい。被着体の屈折率は、粘着剤の屈折率と同様の方法で測定され得る。 And the refractive index of the adherend, a viscoelastic layer (e.g. viscoelastic layer V 1 which is arranged in contact with the adherend, may be viscoelastic layer V 2 is in a form having a viscoelastic layer V 2. ) May be about the same or different. For example, by making the refractive index of the viscoelastic layer (typically the pressure-sensitive adhesive layer) relatively high with respect to the refractive index of the adherend, the viscoelastic layer (typically, the pressure-sensitive adhesive layer) is incident on the pressure-sensitive adhesive layer from the adherend side at an angle equal to or less than the critical angle. The light to be emitted can be refracted to the front side to increase the front brightness. In this case, the refractive index of the adherend may be, for example, 1.55 or less, 1.50 or less, 1.48 or less, 1.45 or less, less than 1.45, or, for example, 1. It can be .10 or higher, 1.20 or higher, 1.30 or higher, or 1.35 or higher. Further, according to the adherend having a relatively high refractive index with respect to the pressure-sensitive adhesive layer, the light incident on the adherend from the pressure-sensitive adhesive layer side can be refracted to the front side to increase the front luminance. In this case, the refractive index of the adherend may be, for example, 1.60 or more, 1.65 or more or 1.70 or more, and for example, 3.00 or less, 2.50 or less or 2.00 or less. Can be. On the other hand, by reducing the difference in refractive index between the pressure-sensitive adhesive layer and the adherend, light reflection at the interface can be suppressed. In this case, the refractive index of the adherend may be about 1.55 to 1.80, about 1.55 to 1.75, or about 1.60 to 1.70. The refractive index of the adherend can be measured in the same manner as the refractive index of the pressure-sensitive adhesive.

　いくつかの好ましい態様では、上記被着体は、上述したいずれかの屈折率を有し、かつ上述したいずれかの全光線透過率を有するものであり得る。このような被着体に貼り付けられるかまたは積層される態様において、ここに開示される技術による効果は特に好ましく発揮される。 In some preferred embodiments, the adherend may have any of the refractive indexes described above and any of the total light transmittances described above. The effects of the techniques disclosed herein are particularly preferred in aspects of attachment or stacking to such adherends.

　好ましい用途の一例として、光学用途が挙げられる。より具体的には、例えば、光学部材を貼り合わせる用途（光学部材貼り合わせ用）や上記光学部材が用いられた製品（光学製品）の製造用途等に用いられる光学用粘着シートとして、ここに開示される層間シートを好ましく用いることができる。 An example of a preferable application is an optical application. More specifically, it is disclosed herein as, for example, an optical adhesive sheet used for bonding optical members (for bonding optical members), manufacturing products using the above optical members (optical products), and the like. The interlayer sheet to be used can be preferably used.

　上記光学部材とは、光学的特性（例えば、偏光性、光屈折性、光散乱性、光反射性、光透過性、光吸収性、光回折性、旋光性、視認性等）を有する部材をいう。上記光学部材としては、光学的特性を有する部材であれば特に限定されないが、例えば、表示装置（画像表示装置）、入力装置等の機器（光学機器）を構成する部材またはこれらの機器に用いられる部材が挙げられ、例えば、偏光板、波長板、位相差板、光学補償フィルム、輝度向上フィルム、導光板、反射フィルム、反射防止フィルム、ハードコート（ＨＣ）フィルム、衝撃吸収フィルム、防汚フィルム、フォトクロミックフィルム、調光フィルム、透明導電フィルム（ＩＴＯフィルム）、意匠フィルム、装飾フィルム、表面保護板、プリズム、レンズ、カラーフィルター、透明基板や、さらにはこれらが積層されている部材（これらを総称して「機能性フィルム」と称する場合がある。）等が挙げられる。なお、上記の「板」および「フィルム」は、それぞれ板状、フィルム状、シート状等の形態を含むものとし、例えば、「偏光フィルム」は、「偏光板」や「偏光シート」等を含み、「導光板」は、「導光フィルム」や「導光シート」等を含むものとする。また、上記「偏光板」は、円偏光板を含むものとする。 The optical member is a member having optical characteristics (for example, polarization, light refraction, light scattering, light reflection, light transmission, light absorption, light diffractivity, light turning property, visibility, etc.). say. The optical member is not particularly limited as long as it has optical characteristics, but is used, for example, as a member constituting a device (optical device) such as a display device (image display device) or an input device, or a member thereof. Examples include polarizing plates, wavelength plates, retardation plates, optical compensation films, brightness improving films, light guide plates, reflective films, antireflection films, hard coat (HC) films, shock absorbing films, antifouling films, and the like. Photochromic film, dimming film, transparent conductive film (ITO film), design film, decorative film, surface protection plate, prism, lens, color filter, transparent substrate, and members in which these are laminated (collectively referred to as these). (Sometimes referred to as a "functional film") and the like. The above-mentioned "plate" and "film" are assumed to include a plate-like, a film-like, a sheet-like form, respectively, and for example, a "polarizing film" includes a "polarizing plate", a "polarizing sheet", and the like. The "light guide plate" shall include a "light guide film", a "light guide sheet" and the like. Further, the above-mentioned "polarizing plate" includes a circular polarizing plate.

　上記表示装置としては、例えば、液晶表示装置、有機ＥＬ（エレクトロルミネッセンス）表示装置、マイクロＬＥＤ（μＬＥＤ）、ミニＬＥＤ（ｍｉｎｉＬＥＤ）、ＰＤＰ（プラズマディスプレイパネル）、電子ペーパーなどが挙げられる。また、上記入力装置としては、タッチパネルなどが挙げられる。 Examples of the display device include a liquid crystal display device, an organic EL (electroluminescence) display device, a micro LED (μLED), a mini LED (miniLED), a PDP (plasma display panel), and electronic paper. Further, examples of the input device include a touch panel and the like.

　上記光学部材としては、特に限定されないが、例えば、ガラス、アクリル樹脂、ポリカーボネート、ポリエチレンテレフタレート、金属薄膜等からなる部材（例えば、シート状やフィルム状、板状の部材）等が挙げられる。なお、この明細書における「光学部材」には、表示装置や入力装置の視認性を保ちながら加飾や保護の役割を担う部材（意匠フィルム、装飾フィルムや表面保護フィルム等）も含むものとする。 The optical member is not particularly limited, and examples thereof include members made of glass, acrylic resin, polycarbonate, polyethylene terephthalate, a metal thin film, and the like (for example, sheet-shaped, film-shaped, and plate-shaped members). The "optical member" in this specification also includes a member (design film, decorative film, surface protective film, etc.) that plays a role of decoration and protection while maintaining the visibility of the display device and the input device.

　ここに開示される層間シートは、例えば、光の透過、反射、拡散、導波、集光、回折等の１または２以上の機能を有するフィルムや蛍光フィルム等の光学フィルムと、他の光学部材（他の光学フィルムであり得る。）との間に配置される態様で用いることができ、好ましくは上記光学フィルムと上記他の光学部材とを接合するために用いられ得る。なかでも、光の導波、集光、回折の少なくとも１つの機能を有する光学フィルムの接合においては、接合層のバルク全体が高屈折率であることが望ましく、ここに開示される技術の好ましい適用対象となり得る。例えば、上記接合層として粘弾性層（粘着剤層）Ｖ１を好ましく利用し得る。 The interlayer sheet disclosed herein includes, for example, an optical film such as a film or a fluorescent film having one or more functions such as light transmission, reflection, diffusion, waveguide, condensing, and diffraction, and other optical members. (It may be another optical film.) It can be used in a manner of being arranged between the optical film and the other optical member, and is preferably used for joining the optical film and the other optical member. In particular, in the bonding of optical films having at least one function of light waveguide, light collection, and diffraction, it is desirable that the entire bulk of the bonding layer has a high refractive index, and the techniques disclosed herein are preferably applied. Can be a target. For example, the viscoelastic layer (adhesive layer) V 1 can be preferably used as the bonding layer.

　ここに開示される層間シートの粘弾性層（好ましくは粘着剤層。例えば、粘弾性層Ｖ１からなる単層構造の粘着剤層、または、粘弾性層Ｖ１および粘弾性層Ｖ２を含む二以上の粘着剤層が直接接して積層した積層構造の粘着剤層）は、例えば、導光フィルム、拡散フィルム、蛍光フィルム、調色フィルム、プリズムシート、レンチキュラーフィルム、マイクロレンズアレイフィルム等の光学フィルムの接合に好ましく用いられ得る。これらの用途では、光学部材の小型化の傾向や高性能化の観点から、薄型化や光取出し効率の向上が求められている。かかる要請に応え得る粘弾性層（例えば粘着剤層）として、ここに開示される層間シートの粘弾性層は好ましく利用され得る。より詳しくは、例えば導光フィルムや拡散フィルムの接合では、接合層としての粘着剤層の屈折率を調整（例えば高屈折率化）することによって薄型化に寄与し得る。蛍光フィルムの接合では、蛍光発光体と粘着剤との屈折率差を適切に調整することにより、光取出し効率（発光効率としても把握され得る。）を向上させることができる。調色フィルムの接合では、調色用顔料との屈折率差が小さくなるように粘着剤の屈折率を適切に調整することで散乱成分を低減し、光透過性の向上に貢献し得る。プリズムシート、レンチキュラーフィルム、マイクロレンズアレイフィルム等の接合においては、粘着剤の屈折率を適切に調整することにより、光の回折を制御し、輝度および／または視野角の向上に貢献し得る。 Viscoelastic layer (preferably the adhesive layer of the interlayer sheet disclosed herein. Including for example, pressure-sensitive adhesive layer having a single layer structure made of viscoelastic layer V 1, or a viscoelastic layer V 1 and viscoelastic layer V 2 The adhesive layer having a laminated structure in which two or more adhesive layers are directly in contact with each other) is, for example, an optical of a light guide film, a diffusion film, a fluorescent film, a toning film, a prism sheet, a lenticular film, a microlens array film, or the like. It can be preferably used for bonding films. In these applications, thinning and improvement of light extraction efficiency are required from the viewpoint of miniaturization and high performance of optical members. As a viscoelastic layer (for example, an adhesive layer) capable of meeting such a demand, the viscoelastic layer of the interlayer sheet disclosed herein can be preferably used. More specifically, for example, in joining a light guide film or a diffusion film, it is possible to contribute to thinning by adjusting the refractive index of the pressure-sensitive adhesive layer as the bonding layer (for example, increasing the refractive index). In the bonding of the fluorescent film, the light extraction efficiency (which can also be grasped as the luminous efficiency) can be improved by appropriately adjusting the difference in the refractive index between the fluorescent light emitter and the pressure-sensitive adhesive. In the bonding of the toning film, the scattering component can be reduced and the light transmittance can be improved by appropriately adjusting the refractive index of the pressure-sensitive adhesive so that the difference in the refractive index from the toning pigment is small. In joining prism sheets, lenticular films, microlens array films, etc., the diffraction of light can be controlled by appropriately adjusting the refractive index of the pressure-sensitive adhesive, which can contribute to the improvement of brightness and / or viewing angle.

　ここに開示される層間シートは、高屈折率の被着体（高屈折率の層や部材等であり得る。）に貼り付けられる態様で好ましく用いられて、上記被着体との界面反射を抑制することができる。かかる態様で用いられる層間シートは、上述のように高屈折率の被着体と該被着体に貼り付けられる粘着剤層（典型的には粘弾性層Ｖ１）との屈折率差が小さく、かつ被着体との界面における密着性が高いことが好ましい。また、外観の均質性を高める観点から、粘着剤層の厚みの均一性が高いことが好ましく、例えば粘着面の表面平滑性が高いことが好ましい。高屈折率の被着体の厚みが比較的小さい場合（例えば５μｍ以下、４μｍ以下、または２μｍ以下である場合）には、反射光の干渉による色付きや色むらを抑制する観点から、界面での反射を抑えることが特に有意義である。このような使用態様の一例として、偏光子と第１位相差層と第２位相差層とをこの順に備える位相差層付き偏光板において、上記偏光子と上記第１位相差層との接合および／または上記第１位相差層と上記第２位相差層との接合に用いられる態様が挙げられる。 The interlayer sheet disclosed herein is preferably used in a manner of being attached to an adherend having a high refractive index (which may be a layer or a member having a high refractive index), and is used to cause interfacial reflection with the adherend. It can be suppressed. Interlayer sheet used in such embodiments, the small difference in refractive index between the high refractive index of the adherend and the adherend to be pasted adhesive layer (typically viscoelastic layer V 1) as described above Moreover, it is preferable that the adhesion at the interface with the adherend is high. Further, from the viewpoint of enhancing the homogeneity of the appearance, it is preferable that the thickness of the pressure-sensitive adhesive layer is high, and for example, the surface smoothness of the pressure-sensitive adhesive surface is high. When the thickness of the adherend with a high refractive index is relatively small (for example, when it is 5 μm or less, 4 μm or less, or 2 μm or less), from the viewpoint of suppressing coloring and color unevenness due to the interference of reflected light, at the interface. Suppressing reflexes is especially meaningful. As an example of such a usage mode, in a polarizing plate with a retardation layer including a polarizing element, a first retardation layer, and a second retardation layer in this order, bonding of the polarizer and the first retardation layer and / Or an embodiment used for joining the first retardation layer and the second retardation layer can be mentioned.

　また、ここに開示される層間シートは、高屈折率の粘弾性層Ｖ１を備えることから、光半導体等の発光層（例えば、主に無機材料により構成された高屈折の発光層）に貼り付けられる態様で好ましく用いられ得る。発光層と粘弾性層Ｖ１との屈折率差を小さくすることにより、それらの界面における反射を抑制し、光取出し効率を向上させ得る。かかる態様で用いられる層間シートは、粘弾性層Ｖ１として、高屈折率の粘着剤層を備えることが好ましい。また、水分による自発光素子の劣化を未然に防ぐ観点から、粘弾性層Ｖ１の吸水率は低いことが好ましい。輝度向上の観点から、層間シートは低着色であることが好ましい。このことは、層間シートに起因する非意図的な着色を抑制する観点からも有利となり得る。 Further, an interlayer sheet disclosed herein, because it comprises a viscoelastic layer V 1 of the high refractive index, bonded to the light-emitting layer of an optical semiconductor such as (e.g., mainly the light emitting layer of the high refractive constituted by an inorganic material) It can be preferably used in the attached embodiment. By reducing the difference in refractive index between the light emitting layer and the viscoelastic layer V 1 , reflection at their interface can be suppressed and the light extraction efficiency can be improved. Interlayer sheet used in such manner, as the viscoelastic layer V 1, it is preferable to provide a pressure-sensitive adhesive layer having a high refractive index. Also, the prevent viewpoint of deterioration of the self-emission elements due to moisture, the water absorption of the viscoelastic layer V 1 was low it is preferable. From the viewpoint of improving the brightness, the interlayer sheet is preferably low in color. This can also be advantageous from the viewpoint of suppressing unintentional coloring caused by the interlayer sheet.

　ここに開示される層間シートの粘弾性層Ｖ１は、カメラや発光装置等の構成部材として用いられるマイクロレンズその他のレンズ部材（例えば、マイクロレンズアレイフィルムを構成するマイクロレンズや、カメラ用マイクロレンズ等のレンズ部材）において、レンズ面を覆うコーティング層、上記レンズ面に対向する部材（例えば、レンズ面に対応する表面形状を有する部材）との接合層、上記レンズ面と上記部材との間に充填される充填層、等として好ましく用いられ得る。ここに開示される粘弾性層Ｖ１は、高屈折率化に適することから、高屈折率のレンズ（例えば、高屈折率樹脂により構成されたレンズや、高屈折率樹脂製の表面層を有するレンズ）に当接して配置されても該レンズとの屈折率差を低減することができる。このことは、上記レンズおよび該レンズを備えた製品の薄型化の観点から有利であり、収差の抑制やアッベ数の向上にも貢献し得る。ここに開示される技術において、粘弾性層Ｖ１を構成する粘弾性材料は、例えば適切な透明部材の凹部または空隙に充填された形態で、それ自体をレンズ樹脂として利用することも可能である。 Viscoelastic layer V 1 of the interlayer sheet disclosed herein, a camera and a microlens is used as a constituent member of the light emitting device or the like other lens member (for example, a microlens constituting a microlens array film, microlens camera Etc.), a coating layer covering the lens surface, a bonding layer with a member facing the lens surface (for example, a member having a surface shape corresponding to the lens surface), and between the lens surface and the member. It can be preferably used as a packed bed to be filled. Viscoelastic layer V 1 disclosed herein have since suitable high refractive index, a high refractive index of the lens (e.g., lens or constituted by the high refractive index resin, the surface layer made of a high refractive index resin Even if it is placed in contact with the lens), the difference in refractive index from the lens can be reduced. This is advantageous from the viewpoint of reducing the thickness of the lens and the product provided with the lens, and can also contribute to the suppression of aberration and the improvement of the Abbe number. In the art disclosed herein, the viscoelastic material constituting the viscoelastic layer V 1, for example in the form filled in a recess or void suitable transparent member, it is also possible to use itself as a lens resin ..

　ここに開示される層間シートを用いて光学部材を貼り合わせる態様としては、特に限定されないが、例えば、（１）ここに開示される層間シートを介して光学部材同士を貼り合わせる態様や、（２）ここに開示される層間シートを介して光学部材を光学部材以外の部材に貼り合わせる態様であってもよいし、（３）ここに開示される層間シートが光学部材を含む形態であって該層間シートを光学部材または光学部材以外の部材に貼り合わせる態様であってもよい。なお、上記（３）の態様において、光学部材を含む形態の層間シートは、例えば、支持体が光学部材（例えば、光学フィルム）である層間シートであり得る。このように支持体として光学部材を含む形態の層間シートは、粘着型光学部材（例えば、粘着型光学フィルム）としても把握され得る。また、ここに開示される層間シートが支持体を有するタイプの粘着シートであって、上記支持体として上記機能性フィルムを用いた場合には、ここに開示される層間シートは、機能性フィルムの少なくとも片面側にここに開示される粘着剤層を有する「粘着型機能性フィルム」としても把握され得る。 The mode in which the optical members are bonded using the interlayer sheet disclosed herein is not particularly limited, and examples thereof include (1) a mode in which the optical members are bonded to each other via the interlayer sheet disclosed here, and (2). ) The optical member may be attached to a member other than the optical member via the interlayer sheet disclosed here, or (3) the interlayer sheet disclosed here includes the optical member. The interlayer sheet may be attached to an optical member or a member other than the optical member. In the aspect of (3) above, the interlayer sheet in the form including the optical member may be, for example, an interlayer sheet in which the support is an optical member (for example, an optical film). As described above, the interlayer sheet in the form of including the optical member as the support can also be grasped as an adhesive type optical member (for example, an adhesive type optical film). Further, when the interlayer sheet disclosed here is a type of adhesive sheet having a support and the functional film is used as the support, the interlayer sheet disclosed here is the functional film. It can also be grasped as a "adhesive type functional film" having an adhesive layer disclosed herein on at least one side.

　上記より、ここに開示される技術によると、ここに開示される層間シートと、該層間シートが貼り付けられた部材（例えば、光学フィルム等の樹脂フィルム）とを備える光学積層体が提供される。層間シートが貼り付けられる部材は、上述した被着体材料の屈折率を有するものであり得る。また、層間シートの粘着面を構成する層（例えば粘弾性層Ｖ１）の屈折率と部材の屈折率との差（屈折率差）は、上述した被着体と粘着剤層との屈折率差であり得る。積層体を構成する部材については、上述の部材、材料、被着体として説明したとおりであるので、重複する説明は繰り返さない。 From the above, according to the technique disclosed herein, an optical laminate including the interlayer sheet disclosed here and a member (for example, a resin film such as an optical film) to which the interlayer sheet is attached is provided. .. The member to which the interlayer sheet is attached may have the refractive index of the adherend material described above. The difference (refractive index difference) between the refractive index of the member layers constituting the adhesive surface of the interlayer sheet (e.g. viscoelastic layer V 1), the refractive index of the adhesive layer and the adherend mentioned above It can be a difference. Since the members constituting the laminated body have been described as the above-mentioned members, materials, and adherends, the overlapping description will not be repeated.

　以上の説明および以下の実施例から理解されるように、この明細書により開示される事項には以下のものが含まれる。
　〔１〕　粘着剤層を含む粘着シートであって、
　上記粘着剤層により構成された粘着面を有し、
　上記粘着剤層は、屈折率が１．５７０超であり、全光線透過率が８６％以上であり、かつヘイズ値が３．０％以下である、粘着シート。
　〔２〕　上記粘着剤層は、厚さが５μｍ以上である、上記〔１〕に記載の粘着シート。
　〔３〕　ガラス板に対する剥離強度（粘着力）が３Ｎ／２５ｍｍ以上である、上記〔１〕また〔２〕に記載の粘着シート。
　〔４〕　上記粘着面は、算術平均粗さＲａが１００ｎｍ以下である、上記〔１〕～〔３〕のいずれかに記載の粘着シート。
　〔５〕　上記粘着剤層は、吸水率が１．０％以下である、上記〔１〕～〔４〕のいずれかに記載の粘着シート。
　〔６〕　上記粘着剤層と光透過性基材とを含む積層体として構成されている、上記〔１〕～〔５〕のいずれかに記載の粘着シート。
　〔７〕　上記光透過性基材は樹脂フィルムである、上記〔６〕に記載の粘着シート。
　〔８〕　上記粘着剤層からなる両面接着性粘着シートである、上記〔１〕～〔５〕のいずれかに記載の粘着シート。
　〔９〕　上記〔１〕～〔８〕のいずれかに記載の粘着シートと、
　上記粘着シートの粘着面上に配置された剥離ライナーと、
を含む、剥離ライナー付き粘着シート。
　〔１０〕　上記〔１〕～〔８〕のいずれかに記載の粘着シートの粘着剤層を形成するために用いられる、粘着剤組成物。 As will be understood from the above description and the following examples, the matters disclosed by this specification include the following.
[1] An adhesive sheet containing an adhesive layer.
It has an adhesive surface composed of the above adhesive layer and has an adhesive surface.
The pressure-sensitive adhesive layer is a pressure-sensitive adhesive sheet having a refractive index of more than 1.570, a total light transmittance of 86% or more, and a haze value of 3.0% or less.
[2] The pressure-sensitive adhesive sheet according to [1] above, wherein the pressure-sensitive adhesive layer has a thickness of 5 μm or more.
[3] The adhesive sheet according to the above [1] and [2], wherein the peel strength (adhesive strength) with respect to the glass plate is 3N / 25 mm or more.
[4] The adhesive sheet according to any one of [1] to [3] above, wherein the adhesive surface has an arithmetic mean roughness Ra of 100 nm or less.
[5] The pressure-sensitive adhesive sheet according to any one of [1] to [4] above, wherein the pressure-sensitive adhesive layer has a water absorption rate of 1.0% or less.
[6] The pressure-sensitive adhesive sheet according to any one of [1] to [5] above, which is configured as a laminate containing the pressure-sensitive adhesive layer and a light-transmitting base material.
[7] The pressure-sensitive adhesive sheet according to [6] above, wherein the light-transmitting base material is a resin film.
[8] The pressure-sensitive adhesive sheet according to any one of [1] to [5] above, which is a double-sided adhesive pressure-sensitive adhesive sheet composed of the pressure-sensitive adhesive layer.
[9] The adhesive sheet according to any one of the above [1] to [8] and
With the release liner placed on the adhesive surface of the adhesive sheet,
Adhesive sheet with release liner, including.
[10] The pressure-sensitive adhesive composition used for forming the pressure-sensitive adhesive layer of the pressure-sensitive adhesive sheet according to any one of the above [1] to [8].

　〔１１〕　芳香環含有モノマー（ｍ１）をモノマー単位として含むアクリル系ポリマー（Ａ）と、
　上記アクリル系ポリマー（Ａ）よりも高屈折率の有機材料である添加剤（ＨＲＯ）と、
を含む、粘着剤組成物。
　〔１２〕　上記添加剤（ＨＲＯ）の屈折率は１．６０以上である、上記〔１１〕に記載の粘着剤組成物。
　〔１３〕　上記アクリル系ポリマー（Ａ）１００重量部に対する上記添加剤（ＨＲＯ）の含有量は、０重量部を超えて６０重量部以下である、上記〔１１〕または〔１２〕に記載の粘着剤組成物。
　〔１４〕　上記添加剤（ＨＲＯ）は、芳香環含有化合物および複素環含有化合物からなる群から選択される少なくとも１種の化合物を含む、上記〔１１〕～〔１３〕のいずれかに記載の粘着剤組成物。
　〔１５〕　上記添加剤（ＨＲＯ）は、１分子内に２以上の芳香環を有する化合物を含む、上記〔１１〕～〔１４〕のいずれかに記載の粘着剤組成物。
　〔１６〕　上記添加剤（ＨＲＯ）は、上記１分子内に２以上の芳香環を有する化合物として、
　（ｉ）２つの非縮合芳香環が直接化学結合した構造を含む、および
　（ｉｉ）２つの芳香環が縮合した構造を含む、
の少なくとも一方を満たす化合物を含む、上記〔１５〕に記載の粘着剤組成物。
　〔１７〕　上記アクリル系ポリマー（Ａ）を構成するモノマー成分において、上記芳香環含有モノマー（ｍ１）の含有量は５０重量％以上である、上記〔１１〕～〔１６〕のいずれかに記載の粘着剤組成物。
　〔１８〕　上記アクリル系ポリマー（Ａ）を構成するモノマー成分において、上記芳香環含有モノマー（ｍ１）の含有量は７０重量％を超えて１００重量％未満であり、
　上記芳香環含有モノマー（ｍ１）のうち５０重量％以上は、ホモポリマーのガラス転移温度が１０℃以下のモノマーである、上記〔１１〕～〔１７〕のいずれかに記載の粘着剤組成物。
　〔１９〕　上記アクリル系ポリマー（Ａ）を構成するモノマー成分は、水酸基およびカルボキシ基の少なくとも一方を有するモノマー（ｍ２）をさらに含有する、上記〔１１〕～〔１８〕のいずれかに記載の粘着剤組成物。
　〔２０〕　上記〔１〕～〔８〕のいずれかに記載の粘着シートの粘着剤層を形成するために用いられる、上記〔１１〕～〔１８〕のいずれかに記載の粘着剤組成物。
　〔２１〕　上記〔１１〕～〔２０〕のいずれかに記載の粘着剤組成物から形成された粘着剤であって、屈折率が１．５７０より高い、粘着剤。
　〔２２〕　上記〔１１〕～〔２０〕のいずれかに記載の粘着剤組成物から形成された粘着剤により構成された粘着剤層を含む、粘着シート。
　〔２３〕　上記粘着剤層のヘイズ値が１．０％以下である、上記〔２２〕に記載の粘着シート。 [11] An acrylic polymer (A) containing an aromatic ring-containing monomer (m1) as a monomer unit, and
An additive (HRO ), which is an organic material having a higher refractive index than the above-mentioned acrylic polymer (A),
A pressure-sensitive adhesive composition.
[12] The pressure-sensitive adhesive composition according to the above [11], wherein the additive (H RO) has a refractive index of 1.60 or more.
[13] The above-mentioned [11] or [12], wherein the content of the additive (HRO ) with respect to 100 parts by weight of the acrylic polymer (A) is more than 0 parts by weight and 60 parts by weight or less. Adhesive composition.
[14] The additive (H RO ) according to any one of the above [11] to [13], which comprises at least one compound selected from the group consisting of an aromatic ring-containing compound and a heterocyclic ring-containing compound. Adhesive composition.
[15] The pressure-sensitive adhesive composition according to any one of [11] to [14] above, wherein the additive (H RO) contains a compound having two or more aromatic rings in one molecule.
[16] The additive ( HRO ) is a compound having two or more aromatic rings in one molecule.
(I) Containing a structure in which two non-condensed aromatic rings are directly chemically bonded, and (ii) Containing a structure in which two non-condensed aromatic rings are condensed.
The pressure-sensitive adhesive composition according to the above [15], which comprises a compound satisfying at least one of the above.
[17] The above-mentioned [11] to [16], wherein the content of the aromatic ring-containing monomer (m1) in the monomer component constituting the acrylic polymer (A) is 50% by weight or more. Adhesive composition.
[18] In the monomer component constituting the acrylic polymer (A), the content of the aromatic ring-containing monomer (m1) is more than 70% by weight and less than 100% by weight.
The pressure-sensitive adhesive composition according to any one of [11] to [17] above, wherein 50% by weight or more of the aromatic ring-containing monomer (m1) is a monomer having a homopolymer glass transition temperature of 10 ° C. or less.
[19] The adhesive according to any one of [11] to [18] above, wherein the monomer component constituting the acrylic polymer (A) further contains a monomer (m2) having at least one of a hydroxyl group and a carboxy group. Agent composition.
[20] The pressure-sensitive adhesive composition according to any one of [11] to [18] above, which is used for forming the pressure-sensitive adhesive layer of the pressure-sensitive adhesive sheet according to any one of [1] to [8] above.
[21] A pressure-sensitive adhesive formed from the pressure-sensitive adhesive composition according to any one of [11] to [20] above, which has a refractive index higher than 1.570.
[22] A pressure-sensitive adhesive sheet containing a pressure-sensitive adhesive layer composed of a pressure-sensitive adhesive formed from the pressure-sensitive adhesive composition according to any one of [11] to [20] above.
[23] The pressure-sensitive adhesive sheet according to [22] above, wherein the haze value of the pressure-sensitive adhesive layer is 1.0% or less.

　〔２４〕　光学用途において積層体の層間に配置して用いられる層間シートであって、
　屈折率ｎ１が１．５７０以上である粘弾性層Ｖ１を含み、かつ
　全光線透過率が８６％以上である；
　ヘイズ値が１．０％以下である；および、
　２５℃における貯蔵弾性率Ｇ’が３０ｋＰａ～７００ｋＰａである；
を満たす、層間シート。
　〔２５〕　厚さが５μｍ以上である、上記〔２４〕に記載の層間シート。
　〔２６〕　上記粘弾性層Ｖ１は、主ポリマーと、上記主ポリマーより分子量の低い可塑化材料とを含む、上記〔２４〕または〔２５〕に記載の層間シート。
　〔２７〕　上記可塑化材料の重量平均分子量は３００００以下である、上記〔２６〕に記載の層間シート。
　〔２８〕　上記粘弾性層Ｖ１に積層された粘弾性層Ｖ２をさらに含み、
　上記粘弾性層Ｖ２の２５℃における貯蔵弾性率Ｇ’Ｖ２は、上記粘弾性層Ｖ１の２５℃における貯蔵弾性率Ｇ’Ｖ１より低い、上記〔２４〕～〔２７〕のいずれかに記載の層間シート。
　〔２９〕　上記粘弾性層Ｖ２の屈折率ｎ２は、上記粘弾性層Ｖ１の屈折率ｎ１より低い、上記〔２８〕に記載の層間シート。
　〔３０〕　上記粘弾性層Ｖ１は、上記〔１１〕～〔１８〕のいずれかに記載の粘着剤組成物から形成された層である、上記〔２４〕～〔２９〕のいずれかに記載の層間シート。
　〔３１〕　上記粘弾性層Ｖ１は、上記〔１〕～〔５〕のいずれかに記載の粘着シートにおける粘着剤層である、上記〔２４〕～〔２９〕のいずれかに記載の層間シート。
　〔３２〕　上記〔２４〕～〔３１〕のいずれか一項に記載の層間シートと、
　上記層間シートに積層された樹脂フィルムと、
を含む、光学積層体。
　〔３３〕　上記〔２４〕～〔３１〕のいずれか一項に記載の層間シートと、
　上記層間シートの少なくとも一方の表面を覆う剥離ライナーと、
を含む、剥離ライナー付き層間シート。 [24] An interlayer sheet used by arranging between layers of a laminated body in optical applications.
Refractive index n 1 comprises a viscoelastic layer V 1 is 1.570 or more, and the total light transmittance is 86% or more;
Haze value is 1.0% or less; and
The storage modulus G'at 25 ° C. is 30 kPa to 700 kPa;
An interlayer sheet that meets the requirements.
[25] The interlayer sheet according to the above [24], which has a thickness of 5 μm or more.
[26] The interlayer sheet according to the above [24] or [25], wherein the viscoelastic layer V 1 contains a main polymer and a thermoplastic material having a molecular weight lower than that of the main polymer.
[27] The interlayer sheet according to the above [26], wherein the weight average molecular weight of the plasticized material is 30,000 or less.
[28] The viscoelastic layer V 2 laminated on the viscoelastic layer V 1 is further included.
'Is V2, the storage modulus G 25 ° C. of the viscoelastic layer V 1' storage modulus G 25 ° C. of the viscoelastic layer V 2 lower than V1, according to any one of [24] - [27] Layered sheet.
[29] the refractive index n 2 of the viscoelastic layer V 2 is lower than the refractive index n 1 of the viscoelastic layer V 1, interlayer sheet according to [28].
[30] the viscoelastic layer V 1 was a layer formed from the pressure-sensitive adhesive composition according to any one of [11] - [18], according to any one of [24] - [29] Layered sheet.
[31] The interlayer sheet according to any one of [24] to [29], wherein the viscoelastic layer V 1 is an adhesive layer in the adhesive sheet according to any one of the above [1] to [5]. ..
[32] The interlayer sheet according to any one of the above [24] to [31] and the interlayer sheet.
The resin film laminated on the interlayer sheet and
Including an optical laminate.
[33] The interlayer sheet according to any one of the above [24] to [31] and the interlayer sheet.
A release liner that covers at least one surface of the interlayer sheet,
Interlayer sheet with release liner, including.

　以下、本発明に関するいくつかの実施例を説明するが、本発明をかかる具体例に示すものに限定することを意図したものではない。なお、以下の説明において、使用量や含有量を表す「部」および「％」は、特に断りがない限り重量基準である。 Hereinafter, some examples of the present invention will be described, but the present invention is not intended to be limited to those shown in such specific examples. In the following description, "parts" and "%" representing the amount used and the content are based on weight unless otherwise specified.

＜アクリル系粘着剤組成物Ｃ１の調製＞
　攪拌羽根、温度計、窒素ガス導入管および冷却器を備えた四つ口フラスコに、モノマー成分としてｍ－フェノキシベンジルアクリレート（共栄社化学株式会社製、商品名「ライトアクリレートＰＯＢ－Ａ」、屈折率：１．５６６、ホモポリマーのＴｇ：－３５℃。以下、「ＰＯＢ－Ａ」と略記する。）９５部および４－ヒドロキシブチルアクリレート（４ＨＢＡ）５部、重合開始剤として２、２’－アゾビスイソブチロニトリル（ＡＩＢＮ）０．２部、および重合溶媒としてトルエン１００部を仕込み、緩やかに攪拌しながら窒素ガスを導入し、フラスコ内の液温を６０℃ 付近に保って６時間重合反応を行い、アクリル系ポリマーＡ１の溶液（５０％）を調製した。このアクリル系ポリマーＡ１の重合平均分子量（Ｍｗ）は５０万であった。上記アクリル系ポリマーＡ１は、上記モノマー成分の組成に基づくＴｇ（すなわちＴｇＴ）が－３５℃であり、芳香環含有モノマーの組成に基づくＴｇ（すなわちＴｇｍ１）が－３５℃である。
　上記アクリル系ポリマーＡ１の溶液（５０％）を酢酸エチルで３０％に希釈し、この溶液３３４部（不揮発分１００部）に、架橋剤としてヘキサメチレンジイソシアネートのイソシアヌレート体（東ソー社製、商品名「コロネートＨＸ」、３官能イソシアネート化合物）の１％酢酸エチル溶液を１０部（不揮発分０．１部）、架橋遅延剤としてアセチルアセトンを２部、架橋触媒としてナーセム第二鉄の１％ 酢酸エチル溶液を１部（不揮発分０．０１部）加えて攪拌混合し、アクリル系粘着剤組成物Ｃ１を調製した。 <Preparation of Acrylic Adhesive Composition C1>
In a four-necked flask equipped with a stirring blade, a thermometer, a nitrogen gas introduction tube and a cooler, m-phenoxybenzyl acrylate (manufactured by Kyoeisha Chemical Co., Ltd., trade name "light acrylate POB-A", refractive index: 1.566, homopolymer Tg: -35 ° C., hereinafter abbreviated as "POB-A") 95 parts and 5 parts of 4-hydroxybutyl acrylate (4HBA), 2,2'-azobis as a polymerization initiator. Add 0.2 parts of isobutyronitrile (AIBN) and 100 parts of toluene as a polymerization solvent, introduce nitrogen gas with gentle stirring, keep the liquid temperature in the flask at around 60 ° C, and carry out the polymerization reaction for 6 hours. A solution (50%) of the acrylic polymer A1 was prepared. The polymerization average molecular weight (Mw) of this acrylic polymer A1 was 500,000. The acrylic polymer A1 has a Tg (that is, Tg T ) based on the composition of the monomer component at −35 ° C. and a Tg (that is, Tg m1 ) based on the composition of the aromatic ring-containing monomer at −35 ° C.
The solution (50%) of the acrylic polymer A1 is diluted to 30% with ethyl acetate, and an isocyanurate compound of hexamethylene diisocyanate (manufactured by Toso Co., Ltd., trade name) is added to 334 parts (nonvolatile content 100 parts) of this solution as a cross-linking agent. 10 parts of 1% ethyl acetate solution of "Coronate HX" (trifunctional isocyanate compound) (0.1 part of non-volatile content), 2 parts of acetylacetone as a cross-linking retardant, 1% ethyl acetate solution of Nasem ferric iron as a cross-linking catalyst 1 part (nonvolatile content 0.01 part) was added and mixed by stirring to prepare an acrylic pressure-sensitive adhesive composition C1.

＜アクリル系粘着剤組成物Ｃ２の調製＞
　攪拌羽根、温度計、窒素ガス導入管および冷却器を備えた四つ口フラスコに、モノマー成分としてＰＯＢ－Ａを７２部、１－ナフチルメチルアクリレート（共栄社化学株式会社製、商品名「ライトアクリレートＮＭＴ－Ａ」、屈折率：１．５９５、ホモポリマーのＴｇ：３１℃。以下、「ＮＭＴ－Ａ」と略記する。）を２３部および４ＨＢＡを５部、重合開始剤としてＡＩＢＮを０．２部、および重合溶媒としてトルエン１００部を仕込み、緩やかに攪拌しながら窒素ガスを導入し、フラスコ内の液温を６０℃ 付近に保って６時間重合反応を行い、アクリル系ポリマーＡ２の溶液（５０％）を調製した。このアクリル系ポリマーＡ２の重合平均分子量（Ｍｗ）は５０万であった。
　温度計、攪拌機、還流冷却管および窒素ガス導入管を備えたセパラブルフラスコに、モノマー成分としてＰＯＢ－Ａを２０部、ＮＭＴ－Ａを８０部、重合開始剤としてＡＩＢＮを０．２部、連鎖移動剤としてα－チオグリセロールを３．５部、およびメチルエチルケトン６７部を投入した後、窒素ガスを流し、攪拌しながら約１時間窒素置換を行った。その後、フラスコを７０℃に加熱し、１２時間反応させて、重量平均分子量（Ｍｗ）４０００、屈折率１．６３のアクリル系オリゴマー（オリゴマーＢ）を得た。
　上記アクリル系ポリマーＡ２の溶液（５０％）を酢酸エチルで３０％に希釈し、この溶液３３４部（不揮発分１００部）に、上記で調製したオリゴマーＢを２０部、架橋剤としてヘキサメチレンジイソシアネートのイソシアヌレート体（東ソー社製、商品名「コロネートＨＸ」、３官能イソシアネート化合物）の１％酢酸エチル溶液を１０部（不揮発分０．１部）、架橋遅延剤としてアセチルアセトンを２部、架橋触媒としてナーセム第二鉄の１％ 酢酸エチル溶液を１部（不揮発分０．０１部）加えて攪拌混合し、アクリル系粘着剤組成物Ｃ２を調製した。 <Preparation of acrylic pressure-sensitive adhesive composition C2>
72 parts of POB-A as a monomer component in a four-necked flask equipped with a stirring blade, a thermometer, a nitrogen gas introduction tube and a cooler, 1-naphthylmethyl acrylate (manufactured by Kyoeisha Chemical Co., Ltd., trade name "Light Acrylate NMT" -A ", refractive index: 1.595, homopolymer Tg: 31 ° C., hereinafter abbreviated as" NMT-A "), 23 parts and 5 parts of 4HBA, 0.2 part of AIBN as a polymerization initiator. , And 100 parts of toluene as a polymerization solvent, nitrogen gas was introduced while gently stirring, and the polymerization reaction was carried out for 6 hours while keeping the liquid temperature in the flask at around 60 ° C., and a solution of acrylic polymer A2 (50%). ) Was prepared. The polymerization average molecular weight (Mw) of this acrylic polymer A2 was 500,000.
In a separable flask equipped with a thermometer, agitator, a reflux condenser and a nitrogen gas introduction tube, 20 parts of POB-A as a monomer component, 80 parts of NMT-A, 0.2 parts of AIBN as a polymerization initiator, and a chain. After adding 3.5 parts of α-thioglycerol and 67 parts of methyl ethyl ketone as the transfer agent, nitrogen gas was flowed and nitrogen substitution was carried out for about 1 hour with stirring. Then, the flask was heated to 70 ° C. and reacted for 12 hours to obtain an acrylic oligomer (oligomer B) having a weight average molecular weight (Mw) of 4000 and a refractive index of 1.63.
The solution (50%) of the acrylic polymer A2 is diluted to 30% with ethyl acetate, and 20 parts of the oligomer B prepared above is added to 334 parts (100 parts of non-volatile content) of this solution, and hexamethylene diisocyanate as a cross-linking agent. 10 parts (0.1 part of non-volatile content) of 1% ethyl acetate solution of isocyanurate (manufactured by Toso Co., Ltd., trade name "Coronate HX", trifunctional isocyanate compound), 2 parts of acetylacetone as a cross-linking retarder, as a cross-linking catalyst 1 part (0.01 part of non-volatile content) of a 1% ethyl acetate solution of Nasem ferric iron was added and mixed by stirring to prepare an acrylic pressure-sensitive adhesive composition C2.

＜アクリル系粘着剤組成物Ｃ３の調製＞
　攪拌羽根、温度計、窒素ガス導入管および冷却器を備えた四つ口フラスコに、モノマー成分として２－エチルヘキシルアクリレート６５部、１Ｈ，１Ｈ，５Ｈ－オクタフルオロペンチルアクリレート（大阪有機化学工業株式会社製、商品名：ビスコート８Ｆ）３０部、Ｎ－ビニル－２－ピロリドン（ＮＶＰ，日本触媒製）３部および４ＨＢＡ２部、重合開始剤としてＡＩＢＮ０．２部、および重合溶媒として酢酸エチル２００部を仕込み、緩やかに攪拌しながら窒素ガスを導入し、フラスコ内の液温を６０℃ 付近に保って９時間重合反応を行い、アクリル系ポリマーＡ３の溶液（３３％）を調製した。上記アクリル系ポリマーＡ３の重合平均分子量（Ｍｗ）は５５万であった。
　上記アクリル系ポリマーＡ３の溶液（３３％）を酢酸エチルで３０％ に希釈し、不揮発分（固形分）１００部に対し、架橋剤としてヘキサメチレンジイソシアネートのイソシアヌレート体（東ソー社製、商品名「コロネートＨＸ」、３官能イソシアネート化合物）の１％酢酸エチル溶液を１０部（不揮発分０．１部）加えて攪拌混合し、アクリル系粘着剤組成物Ｃ３を調製した。 <Preparation of acrylic pressure-sensitive adhesive composition C3>
65 parts of 2-ethylhexyl acrylate as a monomer component, 1H, 1H, 5H-octafluoropentyl acrylate (manufactured by Osaka Organic Chemical Industry Co., Ltd.) in a four-necked flask equipped with a stirring blade, a thermometer, a nitrogen gas introduction tube and a cooler. , Trade name: Viscoat 8F) 30 parts, N-vinyl-2-pyrrolidone (NVP, manufactured by Nippon Catalyst) 3 parts and 4HBA 2 parts, AIBN 0.2 parts as a polymerization initiator, and ethyl acetate 200 parts as a polymerization solvent. Nitrogen gas was introduced with gentle stirring, and the polymerization reaction was carried out for 9 hours while keeping the liquid temperature in the flask at around 60 ° C. to prepare a solution (33%) of the acrylic polymer A3. The polymerization average molecular weight (Mw) of the acrylic polymer A3 was 550,000.
A solution (33%) of the acrylic polymer A3 is diluted to 30% with ethyl acetate, and an isocyanurate compound of hexamethylene diisocyanate as a cross-linking agent (manufactured by Tosoh Corporation, trade name " 10 parts (0.1 part of non-volatile content) of a 1% ethyl acetate solution of "Coronate HX" (trifunctional isocyanate compound) was added and mixed by stirring to prepare an acrylic pressure-sensitive adhesive composition C3.

＜層間シートの作製＞
　（例１）
　上記で調製したアクリル系粘着剤組成物Ｃ１を、片面にシリコーン処理が施されたポリエチレンテレフタレート（ＰＥＴ）フィルムＲ１（厚さ５０μｍ）のシリコーン処理面に塗布し、１３０℃で２分間加熱して、厚さ２５μｍの粘着剤層を形成した。上記粘着剤層の表面に、片面にシリコーン処理が施されたＰＥＴフィルムＲ２（厚さ３８μｍ）のシリコーン処理面を貼り合わせた。このようにして、両面がＰＥＴフィルム（剥離ライナー）Ｒ１，Ｒ２によって保護された形態の粘着剤層（粘着剤層Ｖ１）を得た。なお、剥離ライナーＲ２は、剥離ライナーＲ１に比べて、相対的に軽剥離である。
　また、上記で調製したアクリル系粘着剤組成物Ｃ３を、片面にシリコーン処理が施されたＰＥＴフィルムＲ１（厚さ５０μｍ）のシリコーン処理面に塗布し、１３０℃で２分間加熱して、厚さ１０μｍの粘着剤層Ｖ２を形成した。上記粘着剤層の表面に、片面にシリコーン処理が施されたＰＥＴフィルムＲ２（厚さ３８μｍ） のシリコーン処理面を貼り合わせた。このようにして、両面がＰＥＴフィルム（剥離ライナー）Ｒ１，Ｒ２によって保護された形態の粘着剤層（粘着剤層Ｖ２）を得た。
　粘着剤層Ｖ１，Ｖ２から剥離ライナーＲ２を剥がして粘着面同士を貼り合わせ、ハンドローラーで圧着した。この積層体に対し、５０℃、０．６０ＭＰａの条件で３０分間オートクレーブ処理を実施したのち、５０℃の環境で４８時間エージングを行った。このようにして、粘着剤層Ｖ１／Ｖ２の二層構造からなる層間シート（基材レス両面粘着シート）を得た。この層間シートの表面は、２枚の剥離ライナーＲ１により保護されている、 <Preparation of interlayer sheet>
(Example 1)
The acrylic pressure-sensitive adhesive composition C1 prepared above is applied to the silicone-treated surface of polyethylene terephthalate (PET) film R1 (thickness 50 μm) having a silicone treatment on one side, and heated at 130 ° C. for 2 minutes. A pressure-sensitive adhesive layer having a thickness of 25 μm was formed. A silicone-treated surface of PET film R2 (thickness 38 μm) having been treated with silicone on one side was bonded to the surface of the pressure-sensitive adhesive layer. In this way, both sides to obtain a PET film (release liner) R1, the form of the pressure-sensitive adhesive layer protected by R2 (the pressure-sensitive adhesive layer V 1). The peeling liner R2 is relatively light peeling as compared with the peeling liner R1.
Further, the acrylic pressure-sensitive adhesive composition C3 prepared above is applied to the silicone-treated surface of PET film R1 (thickness 50 μm) having a silicone treatment on one side, and heated at 130 ° C. for 2 minutes to increase the thickness. to form a pressure-sensitive adhesive layer V 2 of 10 [mu] m. A silicone-treated surface of PET film R2 (thickness 38 μm) having been treated with silicone on one side was bonded to the surface of the pressure-sensitive adhesive layer. In this way, both sides obtain PET film (release liner) R1, the form of the pressure-sensitive adhesive layer protected by R2 (pressure-sensitive adhesive layer V 2).
From the adhesive layer V 1, V 2 and removing the release liner R2 bonded to the adhesive faces, and pressed with a hand roller. The laminate was autoclaved for 30 minutes under the conditions of 50 ° C. and 0.60 MPa, and then aged for 48 hours in an environment of 50 ° C. In this way, an interlayer sheet (base-less double-sided adhesive sheet) having a two-layer structure of the adhesive layer V 1 / V 2 was obtained. The surface of this interlayer sheet is protected by two release liners R1.

　（例２）
　粘着剤層Ｖ１，Ｖ２の形成に使用する粘着剤組成物の種類および各粘着剤層の厚さを表１に示すように変更した他は例１と同様にして、粘着剤層Ｖ１／Ｖ２の二層構造からなる層間シート（基材レス両面粘着シート）を得た。 (Example 2)
The pressure-sensitive adhesive layer V 1 is the same as in Example 1 except that the types of pressure-sensitive adhesive compositions used to form the pressure-sensitive adhesive layers V 1 and V 2 and the thickness of each pressure-sensitive adhesive layer are changed as shown in Table 1. An interlayer sheet (base-less double-sided adhesive sheet) having a two-layer structure of / V 2 was obtained.

　（例３～５）
　例１と同様にして、アクリル系粘着剤組成物Ｃ１～Ｃ３の各々からなり、表１に示す厚みを有する単層構造の粘着剤層を作製し、例３～５に係る層間シートとした。 (Examples 3 to 5)
In the same manner as in Example 1, a single-layered pressure-sensitive adhesive layer composed of each of the acrylic pressure-sensitive adhesive compositions C1 to C3 and having the thickness shown in Table 1 was prepared, and used as an interlayer sheet according to Examples 3 to 5.

　得られた層間シートは、２３℃、５０％ＲＨの環境に十分馴染ませた後に、以下の測定および評価に使用した。 The obtained interlayer sheet was sufficiently acclimatized to an environment of 23 ° C. and 50% RH, and then used for the following measurements and evaluations.

＜測定および評価（１）＞
　（屈折率）
　各粘着剤層について、測定波長５８９ｎｍ、測定温度２５℃の条件で、アッベ屈折率計（ＡＴＡＧＯ社製、型式「ＤＲ－Ｍ４」）を使用して屈折率を測定した。結果を表１に示す。 <Measurement and evaluation (1)>
(Refractive index)
The refractive index of each pressure-sensitive adhesive layer was measured using an Abbe refractive index meter (manufactured by ATAGO, model "DR-M4") under the conditions of a measurement wavelength of 589 nm and a measurement temperature of 25 ° C. The results are shown in Table 1.

　（貯蔵弾性率Ｇ’）
　各例に係る粘着剤層を積層して厚み約１．５ｍｍとしたものを測定用サンプルとした。TA Instruments社製のＡＲＥＳを用いて、以下の条件により動的粘弾性測定を行った。測定結果から、２５℃における貯蔵弾性率Ｇ’を読み取った。結果を表１に示す。
　［測定条件］
　変形モード：ねじり
　測定周波数：１Ｈｚ
　昇温速度：５℃／分
　形状：パラレルプレート　７．９ｍｍφ (Storage modulus G')
A sample for which the pressure-sensitive adhesive layers according to each example were laminated to have a thickness of about 1.5 mm was used as a measurement sample. Dynamic viscoelasticity measurements were performed using ARES manufactured by TA Instruments under the following conditions. From the measurement results, the storage elastic modulus G'at 25 ° C. was read. The results are shown in Table 1.
[Measurement condition]
Deformation mode: Torsion measurement frequency: 1Hz
Temperature rise rate: 5 ° C / min Shape: Parallel plate 7.9 mmφ

　（全光線透過率およびヘイズ値）
　各例に係る層間シートを無アルカリガラス（厚さ０．８～１．０ｍｍ、全光線透過率９２％、ヘイズ０．４％）に貼り合わせた試験片を用い、２３℃の測定環境下において、ヘイズメータ（村上色彩技術研究所製、商品名「ＨＡＺＥＭＥＴＥＲ　ＨＭ－１５０」）を用いて、上記試験片の全光線透過率およびヘイズを測定した。測定値から上記無アルカリガラスの全光線透過率およびヘイズを差し引いた値を、層間シートの全光線透過率およびヘイズ値とした。結果を表１に示す。 (Total light transmittance and haze value)
Using a test piece in which the interlayer sheets according to each example were bonded to non-alkali glass (thickness 0.8 to 1.0 mm, total light transmittance 92%, haze 0.4%), under a measurement environment of 23 ° C. , Haze meter (manufactured by Murakami Color Technology Laboratory, trade name "HAZEMETER HM-150") was used to measure the total light transmittance and haze of the above test piece. The value obtained by subtracting the total light transmittance and haze of the non-alkali glass from the measured value was taken as the total light transmittance and haze value of the interlayer sheet. The results are shown in Table 1.

　（対ガラス板剥離強度）
　２３℃、５０％ＲＨの測定環境下において、各例に係る層間シートの一方の面（例１、２では、粘着剤組成物Ｃ３から形成された粘着剤層の表面）から剥離ライナーを剥離し、厚み５０μｍのＰＥＴフィルムを貼り合わせて裏打ちした後、幅２５ｍｍ、長さ１００ｍｍのサイズにカットしたものを試験片とした。試験片から他方の面の剥離ライナーを剥離し、被着体としてのアルカリガラス板（松浪硝子工業社製、厚さ１．３５ｍｍ、青板縁磨品）の表面に、２ｋｇのローラを１往復させて圧着した。これを同環境下に３０分間放置し、次いで加圧脱泡装置（オートクレーブ）に投入して温度５０℃、圧力０．５ＭＰａの条件で３０分間のオートクレーブ処理を行い、さらに２３℃、５０％ＲＨの雰囲気下で２４時間放置した後に、万能引張圧縮試験機を使用して、ＪＩＳ　Ｚ　０２３７：２０００に準じて、引張速度３００ｍｍ／分、剥離角度１８０度の条件で、剥離強度（粘着力）［Ｎ／２５ｍｍ］を測定した。万能引張圧縮試験機としては、ミネベア社製の「引張圧縮試験機、ＴＧ－１ｋＮ」を使用した。 (Peeling strength against glass plate)
The release liner was peeled off from one surface of the interlayer sheet according to each example (in Examples 1 and 2, the surface of the pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition C3) under a measurement environment of 23 ° C. and 50% RH. A PET film having a thickness of 50 μm was laminated and lined, and then cut into a size of 25 mm in width and 100 mm in length as a test piece. The peeling liner on the other side is peeled off from the test piece, and a 2 kg roller is reciprocated once on the surface of the alkaline glass plate (Matsunami Glass Ind., 1.35 mm thick, blue plate edge polished product) as an adherend. And crimped. This was left in the same environment for 30 minutes, then put into a pressure defoaming device (autoclave), autoclaved at a temperature of 50 ° C. and a pressure of 0.5 MPa for 30 minutes, and further at 23 ° C. and 50% RH. After leaving it for 24 hours in the atmosphere of, using a universal tensile compression tester, the peel strength (adhesive strength) [adhesive strength) under the conditions of a tensile speed of 300 mm / min and a peeling angle of 180 degrees according to JIS Z 0237: 2000. N / 25 mm] was measured. As the universal tensile compression tester, a "tensile compression tester, TG-1kN" manufactured by Minebea Co., Ltd. was used.

Figure JPOXMLDOC01-appb-T000001
Figure JPOXMLDOC01-appb-T000001

　表１に示されるように、例１～４の層間シートは、屈折率ｎ１が１．５７０以上、貯蔵弾性率Ｇ’V1(25)が７００ｋＰａ以下の粘着剤層Ｖ１を含み、かつ該層間シートにおいて高い透明性を示した。これらの層間シートは、光学部材の層間の接合に適した実用的な剥離強度を示した。 As shown in Table 1, interlayer sheet of Examples 1-4, the refractive index n 1 is 1.570 or more, the storage elastic modulus G 'V1 is (25) comprises the following adhesive layer V 1 700 kPa, and the It showed high transparency in the interlayer sheet. These interlayer sheets exhibited practical peel strength suitable for bonding between layers of optical members.

＜正面輝度向上効果の評価＞
　白色ＬＥＤ発光光源上に、各例に係る層間シートを貼りつけ、暗室環境下で３０分以上光源を点灯させて安定化させた後、分光放射計 ＳＲ－ＵＬ１Ｒ（株式会社トプコンテクノハウス製）を用いて、層間シートを貼り付けた部分における正面輝度を測定した。３回測定した輝度の平均値を使用し、層間シートを貼り付けていない光源の輝度に対して１０％以上の輝度向上効果があったものをＧ（Good）、輝度向上が１０％未満のものをＰ（Poor）と評価した。 <Evaluation of front brightness improvement effect>
After pasting the interlayer sheet according to each example on the white LED light source and stabilizing the light source by turning it on for 30 minutes or more in a dark room environment, the spectroradiometer SR-UL1R (manufactured by Topcon Techno House Co., Ltd.) is installed. The front luminance was measured at the portion where the interlayer sheet was attached. Using the average value of the brightness measured three times, G (Good) has a brightness improvement effect of 10% or more with respect to the brightness of the light source to which the interlayer sheet is not attached, and the brightness improvement is less than 10%. Was evaluated as P (Poor).

Figure JPOXMLDOC01-appb-T000002
Figure JPOXMLDOC01-appb-T000002

　表２に示されるように、低屈折率の例５の粘着剤層（粘着剤層Ｖ２）と、高屈折率の例３、４の粘着剤層（粘着剤層Ｖ１）とを組み合わせた積層構造の粘着剤層を有する例１、２の層間シートによると、該層間シートを用いない場合に対して１０％以上の正面輝度向上効果が認められた。層間シートの粘着剤層が単層構造である例３～５の層間シートでは、該層間シート単独による正面輝度向上効果は認められなかった。なお、例３、４の層間シートは、より低屈折率の部材（例えば樹脂フィルム）に積層することにより、該部材との積層体において正面輝度向上の効果を発揮し得る。また、例５の層間シートは、より高屈折率の部材（例えば樹脂フィルム）に積層することにより、該部材との積層体において正面輝度向上の効果を発揮し得る。 As shown in Table 2, the adhesive layer (adhesive layer V 2 ) of Example 5 having a low refractive index and the adhesive layer (adhesive layer V 1 ) of Examples 3 and 4 having a high refractive index were combined. According to the interlayer sheets of Examples 1 and 2 having the pressure-sensitive adhesive layer having a laminated structure, an effect of improving the front brightness by 10% or more was observed as compared with the case where the interlayer sheet was not used. In the interlayer sheets of Examples 3 to 5 in which the pressure-sensitive adhesive layer of the interlayer sheet has a single-layer structure, the effect of improving the front luminance by the interlayer sheet alone was not observed. By laminating the interlayer sheets of Examples 3 and 4 on a member having a lower refractive index (for example, a resin film), the effect of improving the front luminance can be exhibited in the laminated body with the member. Further, by laminating the interlayer sheet of Example 5 on a member having a higher refractive index (for example, a resin film), the effect of improving the front luminance can be exhibited in the laminated body with the member.

＜アクリル系粘着剤組成物Ｃ４の調製＞
　攪拌羽根、温度計、窒素ガス導入管および冷却器を備えた四つ口フラスコに、モノマー成分としてＰＯＢ－Ａを７９部、ｎ－ブチルアクリレート（ＢＡ）を２０部、４ＨＢＡを１部、重合開始剤としてＡＩＢＮ０．２部、および重合溶媒としてトルエン１００部を仕込み、緩やかに攪拌しながら窒素ガスを導入し、フラスコ内の液温を６０℃ 付近に保って６時間重合反応を行い、アクリル系ポリマーＡ４の溶液（５０％）を調製した。このアクリル系ポリマーＡ４のＭｗは５２万であった。
　上記アクリル系ポリマーＡ４の溶液（５０％）を酢酸エチルで３０％に希釈し、この溶液３３４部（不揮発分１００部）に、架橋剤としてコロネートＨＸの１％酢酸エチル溶液を１０部（不揮発分０．１部）、架橋遅延剤としてアセチルアセトンを２部、架橋触媒としてナーセム第二鉄の１％ 酢酸エチル溶液を１部（不揮発分０．０１部）加えて攪拌混合し、アクリル系粘着剤組成物Ｃ４を調製した。 <Preparation of acrylic pressure-sensitive adhesive composition C4>
In a four-necked flask equipped with a stirring blade, a thermometer, a nitrogen gas introduction tube and a cooler, 79 parts of POB-A, 20 parts of n-butyl acrylate (BA), and 1 part of 4HBA as monomer components, polymerization started. 0.2 part of AIBN as an agent and 100 parts of toluene as a polymerization solvent were charged, nitrogen gas was introduced while gently stirring, and the polymerization reaction was carried out for 6 hours while keeping the liquid temperature in the flask at around 60 ° C. to carry out an acrylic polymer. A solution of A4 (50%) was prepared. The Mw of this acrylic polymer A4 was 520,000.
The solution (50%) of the acrylic polymer A4 is diluted to 30% with ethyl acetate, and 10 parts (nonvolatile content) of 1% ethyl acetate solution of coronate HX as a cross-linking agent is added to 334 parts (nonvolatile content 100 parts) of this solution. 0.1 part), 2 parts of acetylacetone as a cross-linking retardant, and 1 part (0.01 part of non-volatile content) of 1% ethyl acetate solution of Nasem ferric iron as a cross-linking catalyst are added and mixed by stirring to form an acrylic pressure-sensitive adhesive. Object C4 was prepared.

＜アクリル系粘着剤組成物Ｃ５の調製＞
　モノマー成分の組成（重量比）を、ＰＯＢ－Ａ／エチルカルビトールアクリレート（ＣＢＡ）／４ＨＢＡ＝７９／２０／１に変更した他は、アクリル系ポリマーＡ４の溶液の調製と同様にして、アクリル系ポリマーＡ５の溶液（５０％）を調製した。このアクリル系ポリマーＡ５のＭｗは４６万であった。アクリル系ポリマーＡ４の溶液に代えてアクリル系ポリマーＡ５の溶液を用いた他はアクリル系粘着剤組成物Ｃ４の調製と同様にして、アクリル系粘着剤組成物Ｃ５を調製した。 <Preparation of Acrylic Adhesive Composition C5>
The composition (weight ratio) of the monomer component was changed to POB-A / ethylcarbitol acrylate (CBA) / 4HBA = 79/20/1, but the acrylic polymer was prepared in the same manner as the solution of the acrylic polymer A4. A solution of polymer A5 (50%) was prepared. The Mw of this acrylic polymer A5 was 460,000. The acrylic pressure-sensitive adhesive composition C5 was prepared in the same manner as the preparation of the acrylic pressure-sensitive adhesive composition C4 except that the solution of the acrylic polymer A5 was used instead of the solution of the acrylic polymer A4.

＜アクリル系粘着剤組成物Ｃ６の調製＞
　モノマー成分の組成（重量比）を、Ｐ２Ｈ－Ａ／４ＨＢＡ＝９９／１に変更した他は、アクリル系ポリマーＡ４の溶液の調製と同様にして、アクリル系ポリマーＡ６の溶液（５０％）を調製した。上記モノマー成分の組成における「Ｐ２Ｈ－Ａ」は、フェノキシジエチレングリコールアクリレート（共栄社化学株式会社製、商品名「ライトアクリレートＰ２Ｈ－Ａ」、屈折率：１．５１０、ホモポリマーのＴｇ：－３５℃）を表す。このアクリル系ポリマーＡ６のＭｗは１００万であった。
　アクリル系ポリマーＡ６の溶液（５０％）を酢酸エチルで３０％に希釈し、この溶液３３４部（不揮発分１００部）に、添加剤（ＨＲＯ）として６－エチルアクリレート－ジナフト［２，１－ｂ：１’，２’－ｄ］チオフェン（スガイ化学工業株式会社製の６－アクリロイルオキシエチルジナフトチオフェン、略号：６ＥＤＮＴＡ、屈折率：１．７２２）を２０部、架橋剤としてコロネートＨＸの１％酢酸エチル溶液を１０部（不揮発分０．１部）、架橋遅延剤としてアセチルアセトンを２部、架橋触媒としてナーセム第二鉄の１％ 酢酸エチル溶液を１部（不揮発分０．０１部）加えて攪拌混合し、アクリル系粘着剤組成物Ｃ６を調製した。 <Preparation of acrylic pressure-sensitive adhesive composition C6>
A solution of the acrylic polymer A6 (50%) was prepared in the same manner as the preparation of the solution of the acrylic polymer A4, except that the composition (weight ratio) of the monomer component was changed to P2H-A / 4HBA = 99/1. bottom. "P2HA" in the composition of the above-mentioned monomer component is phenoxydiethylene glycol acrylate (manufactured by Kyoeisha Chemical Co., Ltd., trade name "light acrylate P2HA", refractive index: 1.510, homopolymer Tg: -35 ° C.). show. The Mw of this acrylic polymer A6 was 1 million.
The solution of the acrylic polymer A6 (50%) was diluted to 30% with ethyl acetate, to the solution 334 parts (nonvolatile content 100 parts), the additive (H RO) as 6-ethyl acrylate - dinaphtho [2,1 b: 1', 2'-d] 20 parts of thiophene (6-acryloyloxyethyl dinaphthophene manufactured by Sugai Chemical Industry Co., Ltd., abbreviation: 6EDNTA, refractive index: 1.722), 1 of coronate HX as a cross-linking agent Add 10 parts of% ethyl acetate solution (0.1 part of non-volatile content), 2 parts of acetylacetone as a cross-linking retardant, and 1 part of 1% ethyl acetate solution of Nasem ferric iron as a cross-linking catalyst (0.01 parts of non-volatile content). The mixture was stirred and mixed to prepare an acrylic pressure-sensitive adhesive composition C6.

＜アクリル系粘着剤組成物Ｃ７の調製＞
　アクリル系ポリマーＡ１の溶液（５０％）を酢酸エチルで３０％に希釈し、この溶液３３４部（不揮発分１００部）に、添加剤（可塑化材料）としてＰＯＢ－Ａを１０部、架橋剤としてコロネートＨＸの１％酢酸エチル溶液を１０部（不揮発分０．１部）、架橋遅延剤としてアセチルアセトンを２部、架橋触媒としてナーセム第二鉄の１％ 酢酸エチル溶液を１部（不揮発分０．０１部）加えて攪拌混合し、アクリル系粘着剤組成物Ｃ７を調製した。 <Preparation of Acrylic Adhesive Composition C7>
A solution of acrylic polymer A1 (50%) was diluted to 30% with ethyl acetate, and in 334 parts (100 parts of non-volatile content) of this solution, 10 parts of POB-A as an additive (plasticizing material) and 10 parts of POB-A as a cross-linking agent were used. 10 parts of 1% ethyl acetate solution of coronate HX (0.1 part of non-volatile content), 2 parts of acetylacetone as a cross-linking retardant, 1 part of 1% ethyl acetate solution of Nasem ferric iron as a cross-linking catalyst (non-volatile content 0. 01 part) Add and stir and mix to prepare an acrylic pressure-sensitive adhesive composition C7.

＜アクリル系粘着剤組成物Ｃ８の調製＞
　ＰＯＢ－Ａ１０部を、３－フェノキシベンジルアルコール（東京化成工業株式会社製、屈折率１．５９）１０部に変更した他は、アクリル系粘着剤組成物Ｃ７の調製と同様にして、アクリル系粘着剤組成物Ｃ８を調製した。 <Preparation of acrylic pressure-sensitive adhesive composition C8>
Acrylic pressure-sensitive adhesive in the same manner as the preparation of the acrylic pressure-sensitive adhesive composition C7, except that 10 parts of POB-A was changed to 10 parts of 3-phenoxybenzyl alcohol (manufactured by Tokyo Chemical Industry Co., Ltd., refractive index 1.59). The agent composition C8 was prepared.

＜アクリル系粘着剤組成物Ｃ９の調製＞
　モノマー成分の組成（重量比）を、２ＥＨＡ／ビスコート１３Ｆ／４ＨＢＡ＝４９／５０／１に変更した他は、アクリル系ポリマーＡ３の溶液の調製と同様にして、アクリル系ポリマーＡ９の溶液（５０％）を調製した。上記モノマー成分の組成における「ビスコート１３Ｆ」は、１Ｈ，１Ｈ，２Ｈ，２Ｈ－トリデカフルオロオクチルアクリレート（大阪有機化学工業株式会社製、商品名「ビスコート１３Ｆ」）を表す。このアクリル系ポリマーＡ９のＭｗは５５万であった。アクリル系ポリマーＡ３の溶液に代えてアクリル系ポリマーＡ９の溶液を用いた他はアクリル系粘着剤組成物Ｃ３の調製と同様にして、アクリル系粘着剤組成物Ｃ９を調製した。 <Preparation of acrylic pressure-sensitive adhesive composition C9>
A solution of the acrylic polymer A9 (50%) in the same manner as the preparation of the solution of the acrylic polymer A3, except that the composition (weight ratio) of the monomer component was changed to 2EHA / viscoat 13F / 4HBA = 49/50/1. ) Was prepared. "Viscoat 13F" in the composition of the above-mentioned monomer component represents 1H, 1H, 2H, 2H-tridecafluorooctyl acrylate (manufactured by Osaka Organic Chemical Industry Co., Ltd., trade name "Viscoat 13F"). The Mw of this acrylic polymer A9 was 550,000. An acrylic pressure-sensitive adhesive composition C9 was prepared in the same manner as in the preparation of the acrylic pressure-sensitive adhesive composition C3, except that the solution of the acrylic polymer A9 was used instead of the solution of the acrylic polymer A3.

＜層間シートの作製＞
　（例６～１０）
　粘着剤層Ｖ１，Ｖ２の形成に使用する粘着剤組成物の種類および各粘着剤層の厚さを表３に示すとおりとした他は例１と同様にして、粘着剤層Ｖ１／粘着剤層Ｖ２の二層構造からなる層間シート（基材レス両面粘着シート）を得た。 <Preparation of interlayer sheet>
(Examples 6 to 10)
Except that the kind of the pressure-sensitive adhesive composition used for forming the pressure-sensitive adhesive layer V 1, V 2 and the thickness of each adhesive layer were as shown in Table 3 in the same manner as Example 1, the adhesive layer V 1 / to obtain an interlayer sheet having a two-layer structure of the adhesive layer V 2 (substrate-less double-sided pressure-sensitive adhesive sheet).

　例６～１０により得られた層間シートを２３℃、５０％ＲＨの環境に十分馴染ませた後、上述した「測定および評価（１）」と同様にして、各項目の測定および評価を行った。結果を表３に示す。 After the interlayer sheets obtained in Examples 6 to 10 were sufficiently acclimatized to an environment of 23 ° C. and 50% RH, each item was measured and evaluated in the same manner as in "Measurement and evaluation (1)" described above. .. The results are shown in Table 3.

Figure JPOXMLDOC01-appb-T000003
Figure JPOXMLDOC01-appb-T000003

　表３に示されるように、例６～１０の層間シートは、屈折率ｎ１が１．５７０以上、貯蔵弾性率Ｇ’V1(25)が７００ｋＰａ以下の粘着剤層Ｖ１を含み、かつ該層間シートにおいて高い透明性を示した。これらの層間シートは、光学部材の層間の接合に適した実用的な剥離強度を示した。 As shown in Table 3, interlayer sheet Examples 6-10, the refractive index n 1 is 1.570 or more, the storage elastic modulus G 'V1 is (25) comprises the following adhesive layer V 1 700 kPa, and the It showed high transparency in the interlayer sheet. These interlayer sheets exhibited practical peel strength suitable for bonding between layers of optical members.

　以上、本発明の具体例を詳細に説明したが、これらは例示にすぎず、請求の範囲を限定するものではない。請求の範囲に記載の技術には、以上に例示した具体例を様々に変形、変更したものが含まれる。 Although specific examples of the present invention have been described in detail above, these are merely examples and do not limit the scope of claims. The techniques described in the claims include various modifications and modifications of the specific examples illustrated above.

　　１，２　　層間シート（粘着シート）
　１０　　粘弾性層（ 粘着剤層、粘弾性層Ｖ１）
　１０Ａ　第１の表面（粘着面）
　１０Ｂ　第２の表面
　１１　　第１粘弾性層（第１粘着剤層、粘弾性層Ｖ１）
　１２　　第２粘弾性層（第２粘着剤層、粘弾性層Ｖ２）
　２０　　支持基材
　２０Ａ　第１面
　２０Ｂ　第２面（背面）
　３０，３１，３２　　剥離ライナー
　５０　　剥離ライナー付き粘着シート（剥離ライナー付き層間シート）
　７０　　光学部材
１００　　光学積層体 1,2 interlayer sheet (adhesive sheet)
10 Viscoelastic layer (adhesive layer, viscoelastic layer V 1 )
10A 1st surface (adhesive surface)
10B Second surface 11 First viscoelastic layer (first adhesive layer, viscoelastic layer V 1 )
12 Second viscoelastic layer (second adhesive layer, viscoelastic layer V 2 )
20 Support base material 20A 1st surface 20B 2nd surface (back surface)
30, 31, 32 Peeling liner 50 Adhesive sheet with peeling liner (interlayer sheet with peeling liner)
70 Optical member 100 Optical laminate

Claims (6)

　光学用途において積層体の層間に配置して用いられる層間シートであって、
　屈折率ｎ１が１．５７０以上であり、かつ２５℃における貯蔵弾性率Ｇ’V1が３０ｋＰａ～７００ｋＰａである粘弾性層Ｖ１を含み、
　全光線透過率が８６％以上であり、かつヘイズ値が１．０％以下である、層間シート。 An interlayer sheet used by arranging between layers of a laminated body in optical applications.
Refractive index n 1 is at 1.570 or more, and storage modulus G 'V1 at 25 ° C. comprises a viscoelastic layer V 1 is 30 kPa ~ 700 kPa,
An interlayer sheet having a total light transmittance of 86% or more and a haze value of 1.0% or less. 　厚さが５μｍ以上である、請求項１に記載の層間シート。 The interlayer sheet according to claim 1, which has a thickness of 5 μm or more. 　前記粘弾性層Ｖ１に積層された粘弾性層Ｖ２をさらに含み、
　前記粘弾性層Ｖ２の２５℃における貯蔵弾性率Ｇ’V2は、前記粘弾性層Ｖ１の２５℃における貯蔵弾性率Ｇ’V1より低い、請求項１または２に記載の層間シート。 Further comprising a viscoelastic layer V 2 laminated on the viscoelastic layer V 1,
The 'is V2, the storage modulus G 25 ° C. of the viscoelastic layer V 1' storage modulus G 25 ° C. of the viscoelastic layer V 2 lower than V1, the interlayer sheet according to claim 1 or 2. 　前記粘弾性層Ｖ２の屈折率ｎ２は、前記粘弾性層Ｖ１の屈折率ｎ１より低い、請求項３に記載の層間シート。 The refractive index n 2 of the viscoelastic layer V 2 is lower than the refractive index n 1 of the viscoelastic layer V 1, interlayer sheet according to claim 3. 　請求項１～４のいずれか一項に記載の層間シートと、
　前記層間シートの少なくとも一方の表面を覆う剥離ライナーと、
を含む、剥離ライナー付き層間シート。 The interlayer sheet according to any one of claims 1 to 4 and the interlayer sheet.
With a release liner covering at least one surface of the interlayer sheet,
Interlayer sheet with release liner, including. 　請求項１～４のいずれか一項に記載の層間シートと、
　前記層間シートに積層された樹脂フィルムと、
を含む、光学積層体。

  The interlayer sheet according to any one of claims 1 to 4 and the interlayer sheet.
The resin film laminated on the interlayer sheet and
Including an optical laminate.
PCT/JP2021/012260 2020-03-24 2021-03-24 Interlayer sheet, interlayer sheet with release liner, and optical laminate Ceased WO2021193723A1 (en)

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