TWI798285B - Adhesive sheet - Google Patents

Abstract

An adhesive sheet 1 is provided, which is an adhesive sheet 1 including a base material 11 and an adhesive layer 12 laminated on one side of the base material 11. The arithmetic mean roughness (Ra ) is less than 25 nm, and the adhesive layer 12 is composed of the first polydimethylsiloxane containing at least 2 alkenyl groups in one molecule and the second polydimethylsiloxane containing at least two hydrosilyl groups in one molecule It consists of an addition reaction polysiloxane resin obtained from alkane, a polysiloxane adhesive containing a platinum catalyst, and a polysiloxane adhesive composition containing a silane coupling agent. The above-mentioned adhesive sheet 1 has good removability and also has excellent adhesion to high-smooth substrates.

Description

Adhesive sheet

The present invention relates to an adhesive sheet suitable for use as a protective sheet for protecting a device.

In the past, for devices such as optical components and electronic components, in order to prevent surface scratches during processing, assembly, inspection, etc., an adhesive sheet composed of a base material and an adhesive layer was attached to the surface of the device as a Protective sheet. This protective sheet is peeled off from the device when the protection is no longer required.

In recent years, as optical members, the use of liquid crystal devices has been actively developed to the use of organic light emitting diode (OLED) devices. Furthermore, research on a flexible OLED device (hereinafter sometimes referred to as a "flexible OLED device") has been actively conducted. This flexible OLED device is different from liquid crystal devices and general OLED devices in that it is flexible, so when a conventional protective sheet is used, there is a problem that it is difficult to peel off from the flexible OLED device. Furthermore, during the inspection process of the OLED device, it may be exposed to high temperature conditions, so the protective sheet needs to have heat resistance. In this case, a silicone-based adhesive is preferable as the adhesive for forming the adhesive layer.

Patent Document 1 and Patent Document 2 disclose silicone-based adhesives or examples of their use. Patent Document 1 discloses a room-temperature-curable polysiloxane-based adhesive that reacts with moisture in the air and hardens. In particular, in the examples of Patent Document 1, a composition containing a predetermined polyorganosiloxane (polyorganosiloxane) and a partial hydrolyzate of an organosilicon compound is poured into a mold and heated at 23°C and 50%RH. Cured for 7 days, thereby forming a sheet made of polysiloxane adhesive.

Furthermore, Patent Document 2 discloses a surface protection film comprising a base material and an adhesive layer formed of a polysiloxane-based adhesive laminated on one side of the base material, wherein An antistatic layer is provided on the adhesive layer side of the base material. [Prior art literature] [Patent Document]

[Patent Document 1] Japanese Patent Laid-Open No. 2007-321122 [Patent Document 2] Japanese Patent Laid-Open No. 2013-107998

[Problems to be Solved by the Invention]

The silicone-based adhesive disclosed in the aforementioned Patent Document 1 is intended to be used for sealing, laminating, and coating, and cannot exhibit sufficient removability for an adherend. Therefore, an adhesive sheet including an adhesive layer composed of the polysiloxane adhesive is not suitable for use as a protective sheet of a device.

Furthermore, the luminescence detection of the OLED device is inspected more strictly than the luminescence detection of the liquid crystal device, so the protective sheet needs to have high transparency. However, in the examples of Patent Document 2, since a base material with a relatively high surface roughness is used, the surface protection film included in the base material has a relatively low surface smoothness of the base material. For the aforementioned reasons, this surface protection film cannot sufficiently obtain high transparency required for light emission detection of an OLED device.

Furthermore, since the traditional polysiloxane-based adhesive has low adhesion to the substrate, the adhesive layer made of the polysiloxane-based adhesive is prone to peeling off from the substrate. In particular, the higher the smoothness of the surface of the substrate on which the adhesive layer is provided, the lower the adhesiveness of the adhesive layer to the substrate, and the above-mentioned peeling is more likely to occur.

The present invention was made in view of the above circumstances, and an object of the present invention is to provide an adhesive sheet having good removability and excellent adhesion to a substrate having high smoothness. [Means used to solve the problem]

In order to achieve the above object, firstly, the present invention provides an adhesive sheet, which is an adhesive sheet comprising a substrate and an adhesive layer laminated on one surface of the substrate, wherein the substrate is laminated with the adhesive The arithmetic average roughness (Ra) of the surface of the adhesive layer is 25nm or less, and the aforementioned adhesive layer is composed of the first polydimethylsiloxane containing at least 2 alkenyl groups in one molecule and at least two hydrogenated polydimethylsiloxanes in one molecule. It consists of an addition-reactive polysiloxane resin obtained from a silane-based second polydimethylsiloxane, a polysiloxane adhesive containing a platinum catalyst, and a polysiloxane-based adhesive composition containing a silane coupling agent. (Invention 1).

According to the adhesive sheet of the above invention (Invention 1), since the adhesive layer is composed of the silicone adhesive containing the above-mentioned addition reaction type silicone resin, good removability can be obtained. Furthermore, this adhesive sheet can also have excellent adhesion to substrates with high smoothness because the adhesive layer is composed of a silicone adhesive containing a silane coupling agent.

In the above invention (Invention 1), the content of the silane coupling agent is preferably not less than 0.001 parts by mass and not more than 3.0 parts by mass relative to 100 parts by mass of the addition reaction type silicone resin (Invention 2).

In the above inventions (Inventions 1 and 2), it is preferable that the silicone adhesive contains a silicone resin (Invention 3).

In the above inventions (Inventions 1 to 3), the content of the silicone resin is preferably 1 part by mass or more and 40 parts by mass or less with respect to 100 parts by mass of the addition reaction type silicone resin (Invention 4) .

In the above inventions (Inventions 1 to 4), the haze value of the base material is preferably 3.5% or less (Invention 5).

In the above inventions (Inventions 1 to 5), it is preferable to use it as a protective sheet for protecting a device (Invention 6).

In the above invention (Invention 6), the aforementioned device is preferably a flexible device (Invention 7). [Invention effect]

The adhesive sheet according to the present invention has good removability and excellent adhesion to substrates with high smoothness.

Hereinafter, embodiments of the present invention will be described. [adhesive sheet] As shown in FIG. 1, according to the adhesive sheet 1 of this embodiment, the base material 11, the adhesive layer 12 laminated on the surface of one side (the lower side in FIG. 1) of the base material 11, and the adhesive layer 12 are laminated. The release sheet 13 is formed on the surface opposite to the substrate 11 (the lower side in FIG. 1 ). This release sheet 13 is used to protect the adhesive layer 12 before the adhesive sheet 1 is used, and is peeled and removed when the adhesive sheet 1 is used. According to the adhesive sheet 1 of this embodiment, the release sheet 13 may be omitted.

1. Parts and materials (1) Substrate In the substrate 11 of the present embodiment, the arithmetic average roughness (Ra) of the surface on which the adhesive layer is laminated is 25 nm or less. Accordingly, the adhesive sheet 1 according to the present embodiment has high transparency, and is suitable as a protective sheet for a device that performs light emission detection (such as a liquid crystal device or an OLED device). From this point of view, the arithmetic mean roughness (Ra) is preferably not more than 15 nm, particularly preferably not more than 9 nm, and more preferably not more than 4.5 nm. In addition, the lower limit of the above-mentioned arithmetic average roughness (Ra) is not particularly limited, but is preferably at least 0.1 nm, particularly preferably at least 0.5 nm, and more preferably at least 1.0 nm. The details of the measurement method of the above-mentioned arithmetic mean roughness (Ra) are described in the test examples described later.

In the substrate 11 of this embodiment, the root mean square height (Rq) of the surface on which the adhesive layer is laminated is preferably 45 nm or less, more preferably 20 nm or less, particularly preferably 10 nm or less, and 6 nm or less. better. By making this root mean square height (Rq) exist in the said range, the transparency of the adhesive sheet 1 according to this embodiment becomes higher. The lower limit of the root-mean-square height (Rq) is not particularly limited, but is preferably at least 0.5 nm, particularly preferably at least 1.0 nm, and more preferably at least 2.0 nm. The details of the measurement method of the above-mentioned root mean square height (Rq) are described in the test examples described later.

In the substrate 11 of this embodiment, the maximum height (Rz) of the surface on which the adhesive layer is laminated is preferably 400 nm or less, more preferably 300 nm or less, particularly preferably 200 nm or less, and more preferably 130 nm or less. . By making this maximum height (Rz) exist in the said range, the transparency of the adhesive sheet 1 according to this embodiment becomes higher. The lower limit of the maximum height (Rz) is not particularly limited, but is preferably at least 10 nm, particularly preferably at least 20 nm, and more preferably at least 30 nm. The details of the measurement method of the above-mentioned maximum height (Rz) are described in the test example described later.

In the base material 11 of this embodiment, the maximum cross-sectional height (Rt) of the surface on which the adhesive layer is laminated is preferably 500 nm or less, particularly preferably 400 nm or less, and more preferably 300 nm or less. By making this maximum cross-sectional height (Rt) exist in the said range, the transparency of the adhesive sheet 1 according to this embodiment becomes higher. The lower limit of the above-mentioned maximum cross-sectional height (Rt) is not particularly limited, but is preferably at least 10 nm, particularly preferably at least 30 nm, and more preferably at least 50 nm. The details of the method of measuring the above-mentioned maximum section height (Rt) are described in Test Examples described later.

The total light transmittance of the substrate 11 in this embodiment is preferably 80% or higher, particularly preferably 85% or higher, and more preferably 88% or higher. By making the total light transmittance 80% or more, the transparency of the adhesive sheet 1 according to this embodiment becomes higher. The upper limit of the total light transmittance is not particularly limited, but is preferably 100% or less, particularly preferably 98% or less, and more preferably 93% or less. In addition, the total light transmittance of the substrate 11 is measured according to JIS K7361-1:1997 and ASTM D 1003, and the detailed measurement method is as described in the test example described later.

The substrate 11 of this embodiment preferably has a haze value of 3.5% or less, more preferably 2.5% or less, particularly preferably 2.0% or less, and more preferably 1.3% or less. By setting the haze value to 3.5% or less, the transparency of the adhesive sheet 1 according to the present embodiment becomes higher, and for example, light emission detection of an OLED device can be performed without any problem. The lower limit of the haze value is not particularly limited, but is preferably at least 0.1%, particularly preferably at least 0.2%, and more preferably at least 0.3%. In addition, the haze value of the substrate 11 is measured according to JIS K7136:2000 and ASTM D 1003, and the detailed measurement method is as described in the test examples described later.

The substrate 11 is not particularly limited as long as the above-mentioned arithmetic mean roughness (Ra) can be realized and the adhesive layer 12 can be laminated at the same time. When the adhesive sheet 1 according to the present embodiment is used as a protective sheet of a device, it is preferable that the substrate 11 is translucent to light of a wavelength used for luminescence detection of the device. Furthermore, as the base material 11 , it is preferable to use a base material having heat resistance to high temperatures (for example, 90 to 150° C.) applied when inspecting a device to be protected.

As a specific example of the substrate 11, polyesters such as polyethylene terephthalate, polyethylene naphthalate, and polybutylene terephthalate can be used. Cellulose such as diacetyl cellulose, triacetyl cellulose, acetyl cellulose butyrate, polyimide, polyether imide Plastic film made of resins such as polyether imide, polycarbonate, polymethylpentene, polyphenylene sulfide, liquid crystal polymer, etc. ) is preferred. The above-mentioned plastic film may be a film composed of a single layer, or a film obtained by laminating multiple layers of the same type or different types. Among the above, polyester film or cellulose film is preferable from the viewpoint of transparency and cost, and polyester film is preferable from the viewpoint of heat resistance, and polyethylene terephthalate is preferable. Diester films are especially preferred.

In addition, the above-mentioned plastic film may also contain additives such as antistatic agent, heat resistance enhancer, ultraviolet absorber, etc., and it is better not to contain filler when high transparency is required.

The base material 11 of the present embodiment may include desired functional layers on one surface or both surfaces as long as the above-mentioned arithmetic average roughness (Ra) can be realized. As this functional layer, an antistatic layer, a hard coat layer, an antireflection layer, an antiglare layer, a lubricant layer, a color correction layer etc. are mentioned, for example. Among the above, it is preferable that the base material 11 includes an antistatic layer. By making the base material 11 include an antistatic layer, the adhesive sheet 1 of the present embodiment has desired antistatic properties. Thereby, it is possible to suppress peeling static electricity when the release sheet 13 is peeled from the adhesive sheet 1 or when the adhesive sheet 1 is peeled from the adherend, and it is possible to effectively suppress debris or dust from adhering to the adhesive sheet 1 or being adhered. thing.

The above-mentioned antistatic layer is preferably a film layer composed of, for example, a composition for an antistatic layer containing a conductive polymer and a binder resin. Conventionally known materials can be used for the conductive polymer and the bonding resin.

Under the situation that one side surface or both sides surfaces of base material 11 comprise antistatic layer, the thickness of antistatic layer (in the case of both sides surface, refers to the thickness of the antistatic layer on one side thereof), from easy From the viewpoint of exhibiting good antistatic properties, it is preferably at least 10 nm, particularly preferably at least 20 nm, and more preferably at least 30 nm. Furthermore, the aforementioned thickness is preferably not more than 200 nm, particularly preferably not more than 150 nm, and more preferably not more than 100 nm, from the viewpoint of the strength and cost of the substrate 11 .

Furthermore, when the base material 11 has antistatic properties, its surface resistivity is preferably 1×10 ¹⁰ Ω/sq or less, particularly preferably 1×10 ⁹ Ω/sq or less, and 1×10 ⁸ Ω/sq or less. Ω/sq or less is more preferable. When the surface resistivity is 1×10 ¹⁰ Ω/sq or less, it is easy to suppress the peeling electrostatic voltage of the adhesive sheet 1 to 0.2 kV or less, and it is possible to easily prevent debris from adhering due to electrostatic effects or causing defects in the electrical properties of the device. Influence. In addition, the lower limit of the surface resistivity is not particularly limited, but it is preferably about 1×10 ⁵ Ω/sq or more. In addition, the detail of the measurement method of the said surface resistivity and the said peeling electrostatic voltage is as described in the test example mentioned later.

Furthermore, as long as the base material 11 can achieve the above-mentioned arithmetic average roughness (Ra), it can also be surface treated by oxidation or roughening, or treated with a surface treatment agent (primer) according to requirements, so as to improve and adhere. The purpose of the adhesion of the agent layer 12. Examples of the oxidation method include corona discharge treatment, plasma discharge treatment, chromium oxidation treatment (wet method), flame treatment, hot air treatment, ozone, and ultraviolet irradiation treatment. In addition, as a roughening method, a sand blast method, a thermal spray method, etc. are mentioned. These surface treatment methods can be appropriately selected according to the type of base material.

The thickness of the substrate 11 is preferably at least 10 μm, particularly preferably at least 25 μm, and more preferably at least 38 μm. Furthermore, the thickness of the substrate 11 is preferably not more than 200 μm, particularly preferably not more than 175 μm, and more preferably not more than 150 μm. By setting the thickness of the base material 11 within the above-mentioned range, the transparency, heat resistance, and processability of sticking/peeling of the adhesive sheet 1 according to the present embodiment become more excellent.

(2) Adhesive layer The adhesive layer 12 is composed of a first polydimethylsiloxane (polydimethylsiloxane) containing at least 2 alkenyl groups in one molecule and a second polydimethylsiloxane (polydimethylsiloxane) containing at least two hydrosilyl groups in one molecule It consists of an addition reaction polysiloxane resin obtained from oxane, a polysiloxane adhesive containing a platinum catalyst, and a polysiloxane adhesive composition containing a silane coupling agent.

According to the adhesive sheet 1 of this embodiment, since the adhesive layer 12 is composed of the silicone adhesive containing the above-mentioned addition reaction type silicone resin, it is possible to achieve good removability on the adherend. . Furthermore, since the adhesive layer 12 is composed of a polysiloxane-based adhesive composition containing a silane coupling agent, excellent adhesion to the substrate 11 can be achieved. In particular, even when the arithmetic average roughness (Ra) of the surface of the substrate 11 on which the adhesive layer is laminated is within the aforementioned range, excellent adhesion to the substrate 11 and the adhesive layer 12 can be ensured. sex. Therefore, the adhesive sheet 1 according to the present embodiment is suitable as a protective sheet for devices, and is particularly suitable as a protective sheet requiring high transparency, such as a protective sheet for OLED devices.

(2-1) Silicone adhesive The silicone adhesive is sufficient as long as it contains the above-mentioned addition reaction type silicone resin and a platinum catalyst, and is capable of adhering and peeling the adhesive sheet 1 according to this embodiment to the adherend, and there is no special restrictions. According to the adhesive sheet 1 of this embodiment, when it is used as a protective sheet to protect an adherend that is exposed to high temperature (for example, 90 to 150°C) during inspection or use, the silicone adhesive is used even in such a case. Adhesive materials that can also exhibit stable adhesion at high temperatures are preferred. In particular, when the adherend is a flexible device such as a flexible OLED device, in order to easily peel the adhesive sheet 1 according to the present embodiment from the flexible device, a slight adhesiveness excellent in removability is selected. Silicone adhesive is preferred. In addition, silicone adhesives exhibit stable adhesion even at high temperatures and are superior in heat resistance compared to acrylic adhesives.

The addition reaction polysiloxane resin of this embodiment is composed of a first polydimethylsiloxane containing at least two alkenyl groups in one molecule and a second polydimethylsiloxane containing at least two hydrosilyl groups in one molecule. Methyl siloxane obtained.

Examples of the alkenyl group contained in the first polydimethylsiloxane include vinyl, allyl, propenyl, butenyl, pentenyl, hexenyl, heptenyl, and octenyl. etc., among which vinyl is particularly preferred.

The content of alkenyl groups in the first polydimethylsiloxane (the ratio of the number of alkenyl groups relative to the number of methyl groups bonded to silicon atoms) is preferably 0.005 mol% or more, and 0.01 mol% More than % is especially good. Furthermore, the content is preferably not more than 0.1 mol%, and is particularly preferably not more than 0.05 mol%. The first polydimethylsiloxane preferably has an alkenyl group at both ends of the molecular chain, and may have an alkenyl group on a side chain. By making 1 molecule of the first polydimethylsiloxane contain at least 2 alkenyl groups, and the content of alkenyl groups is within the above range, a crosslinked structure with high crosslink density can be formed, and can be removed Excellent adhesive layer.

The degree of polymerization (the number of siloxane bonds) of the first polydimethylsiloxane is preferably at least 200, and particularly preferably at least 500. Furthermore, the degree of polymerization is preferably 5,000 or less, and particularly preferably 3,000 or less.

The content of the hydrosilyl groups in the second polydimethylsiloxane is preferably 2 or more in 1 molecule, and particularly preferably 4 or more. Furthermore, the content is preferably 300 or less, and particularly preferably 200 or less, per molecule.

The degree of polymerization of the second polydimethylsiloxane is preferably at least 50, and particularly preferably at least 100. The degree of polymerization is preferably 2,000 or less, and particularly preferably 1,500 or less.

Furthermore, the compounding ratio of the 2nd polydimethylsiloxane is preferably 0.01 mass part or more with respect to 100 mass parts of 1st polydimethylsiloxane, and especially preferably 0.1 mass part or more. Furthermore, the blending ratio is preferably 20 parts by mass or less, and particularly preferably 10 parts by mass or less.

As described above, by making the content of each functional group and the compounding ratio of the first polydimethylsiloxane and the second polydimethylsiloxane within the above range, the first polydimethylsiloxane It has a good addition reaction with the second polydimethylsiloxane, and it is easy to obtain an addition reaction polysiloxane resin.

In addition, the first polydimethylsiloxane preferably does not contain a hydrosilyl group, and the second polydimethylsiloxane preferably does not contain an alkenyl group.

The weight average molecular weight of the first polydimethylsiloxane is preferably at least 20,000, and particularly preferably at least 300,000. The weight average molecular weight is preferably not more than 1.3 million, and particularly preferably not more than 1.2 million. Furthermore, the weight average molecular weight of the second polydimethylsiloxane is preferably at least 300, and particularly preferably at least 500. Furthermore, the weight average molecular weight is preferably 1400 or less, and is particularly preferably 1200 or less. In addition, in this specification, a weight average molecular weight is a standard polystyrene conversion value measured by the gel permeation chromatography (GPC) method.

The platinum catalyst is not particularly limited as long as it can harden the addition reaction type silicone resin (addition reaction between the first polydimethylsiloxane and the second polydimethylsiloxane). Preferred examples of platinum catalysts include platinum group metals such as particulate platinum, particulate platinum adsorbed on a carbon powder carrier, chloroplatinic acid, alcohol-modified chloroplatinic acid, olefin complexes of chloroplatinic acid, palladium, and rhodium. Compounds are preferred.

The compounding amount of the catalyst of the above-mentioned addition reaction type polysiloxane resin is preferably 0.01 mass part or more, and particularly preferably 0.05 mass part or more, with respect to 100 mass parts of the catalyst of the above-mentioned addition reaction type silicone resin. Furthermore, the compounding amount is preferably not more than 3 parts by mass, and particularly preferably not more than 2 parts by mass.

The polysiloxane adhesive preferably further contains polysiloxane resin. When the silicone adhesive contains a silicone resin, the obtained adhesive layer 12 becomes more excellent in adhesiveness to a base material. Thereby, even if a highly smooth substrate is used, excellent substrate adhesion can be exhibited. As the polysiloxane resin, for example, the M unit which is a monofunctional siloxane unit [(CH ₃ ) ₃ SiO _1/2 ] and the Q unit which is a tetrafunctional siloxane unit [SiO _4/2 ] are used. The formed MQ resin is preferred. In this case, the molar ratio of M unit/Q unit is preferably not less than 0.6 and not more than 1.7.

In the case where the silicone adhesive contains a silicone resin, the blending amount of the silicone resin relative to 100 parts by mass of the addition reaction type silicone resin is preferably 1 part by mass or more, and 3 parts by mass The above is particularly preferred, and more preferably 5 parts by mass or more. Furthermore, the above-mentioned blending amount is preferably not more than 40 parts by mass, particularly preferably not more than 30 parts by mass, and more preferably not more than 20 parts by mass. By making the compounding quantity of the silicone resin into the said range, the adhesiveness of a base material and the removability as an adhesive sheet can be compatible to a higher degree.

(2-2) Silane coupling agent The silane coupling agent is preferably an organosilicon compound containing at least one alkoxy group bonded to a silicon atom in the molecule and at least one functional group reactive with organic compounds.

Examples of the above-mentioned functional groups reactive with organic compounds include glycidyl groups, amine groups, vinyl groups, isocyanate groups, mercapto groups, (meth)acryl groups, styryl groups, ureido groups, etc. at least one of them. Among the above, from the viewpoint of easy realization of excellent adhesion between the adhesive layer 12 and the substrate 11, the silane coupling agent preferably has at least one of a glycidyl group and an amine group, and preferably has Amine groups are particularly preferred. Furthermore, from the viewpoint of improving the reactivity of the above-mentioned functional groups and at the same time improving the compatibility with other components in the polysiloxane-based adhesive composition, the above-mentioned functional groups and the silicon bonded to the alkoxy group Preferably, a hydrocarbon chain represented by the general formula C _n H _2n (n represents a positive integer) is inserted between the atoms as a spacer. In this case, the value of n in the above general formula C _n H _2n is preferably 1 or more, and particularly preferably 2 or more. In addition, the value of n is preferably 10 or less, and particularly preferably 8 or less.

Examples of silane coupling agents having a glycidyl group include 3-glycidylpropyltrimethoxysilane, 3-glycidylpropylmethyldiethoxysilane, 2-(3,4-cyclo Oxycyclohexyl)ethyltrimethoxysilane, 3-glycidylpropylmethyldimethoxysilane, 3-glycidylpropyltriethoxysilane, 8-glycidylpropyltrimethoxysilane wait. Among the above, 3-glycidylpropyltrimethoxysilane, 3-glycidylpropylmethylsilane, and Preferably, it is at least one kind of 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, and 8-glycidylpropyltrimethoxysilane.

Furthermore, the silane coupling agent having a glycidyl group may be an oligomer containing the above materials as constituent monomers. In this case, the epoxy equivalent of the oligomer is preferably at least 100 g/mol, and particularly preferably at least 150 g/mol. Furthermore, the epoxy equivalent is preferably not more than 1000 g/mol, and is particularly preferably not more than 900 g/mol. Furthermore, the alkoxy group content of the oligomer is preferably at least 20% by mass, and particularly preferably at least 30% by mass. Furthermore, the content of the alkoxy group is preferably not more than 80% by mass, and particularly preferably not more than 70% by mass. By using such an oligomer, it is easy to achieve excellent adhesion between the adhesive layer 12 and the base material 11 .

Examples of silane coupling agents having amino groups include 3-aminopropyltrimethoxysilane, N-2-(aminoethyl)-3-aminopropyltrimethoxysilane, N-2 -(aminoethyl)-8-octyltrimethoxysilane, N-2-(aminoethyl)-3-aminopropylmethyldimethoxysilane, 3-aminopropyltrimethoxysilane Oxysilane, 3-triethoxysilyl-N-(1,3-dimethyl-butylene)propylamine, N-phenyl-3-aminopropyltrimethoxysilane, N-(ethylene benzyl)-2-aminoethyl-3-aminopropyltrimethoxysilane hydrochloride, etc. Among the above, 3-aminopropyltrimethoxysilane, N-2-(aminoethyl At least one of )-3-aminopropyltrimethoxy and N-2-(aminoethyl)-8-aminooctyltrimethoxysilane is preferable.

In addition, the above-mentioned silane coupling agents may be used alone or in combination of two or more.

In the silicone-based adhesive composition, the content of the silane coupling agent is preferably at least 0.001 parts by mass, particularly preferably at least 0.005 parts by mass, relative to 100 parts by mass of the addition-reactive silicone resin, and More preferably, it is 0.01 mass part or more. Furthermore, the content of the silane coupling agent is preferably not more than 3.0 parts by mass, more preferably not more than 2.0 parts by mass, and most preferably not more than 1.0 parts by mass, relative to 100 parts by mass of the addition-reactive polysiloxane resin. And it is more preferably 0.5 parts by mass or less. By making content of a silane coupling agent 0.001 mass part or more, it becomes easy to realize the outstanding adhesiveness between the adhesive agent layer 12 and the base material 11. Furthermore, by making the content of the silane coupling agent 3.0 parts by mass or less, the adhesive force between the adhesive sheet 1 and the adherend according to the present embodiment can be suppressed from becoming too high, and the adhesive sheet 1 can ensure good removability. .

(2-3) Other ingredients The silicone-based adhesive composition of this embodiment may contain various additives such as antistatic agents, dispersants, crosslinking agents, reaction inhibitors, diffusion fillers, pigments, dyes, and ultraviolet absorbers in addition to the above-mentioned components. .

(2-4) The thickness of the adhesive layer The thickness of the adhesive layer 12 is preferably at least 5 μm, particularly preferably at least 10 μm, and more preferably at least 15 μm. Furthermore, the thickness of the adhesive layer 12 is preferably less than 100 μm, particularly preferably less than 75 μm, and more preferably less than 50 μm. By setting the thickness of the adhesive layer 12 within the above-mentioned range, the adhesive sheet 1 according to the present embodiment becomes easy to exhibit appropriate adhesive force to an adherend. As a result, unintentional peeling of the adhesive sheet 1 from the adherend can be effectively suppressed, and at the same time it becomes easy to achieve good removability of the adhesive sheet 1 .

(3) Peeling sheet The release sheet 13 is not particularly limited as long as it does not adversely affect the adhesive layer 12. For example, polyethylene film, polypropylene film, polybutene film, polybutadiene film, polymethylpentene film, Film, polyvinyl chloride film, vinyl chloride copolymer film, polyethylene terephthalate film, polyethylene naphthalate film, polybutylene terephthalate film, polyurethane film, ethylene-vinyl acetate Film, ionomer resin film, ethylene-(meth)acrylic acid copolymer film, ethylene-(meth)acrylate copolymer film, polystyrene film, polycarbonate film, polyimide film, fluororesin film wait. Furthermore, crosslinked films of the above materials may also be used. Furthermore, laminated films of the above materials can also be used. Among the above, a polyethylene terephthalate film having excellent handling properties is preferable.

A release treatment may be applied to the surface of the release sheet 13 that is in contact with the adhesive layer 12 . Examples of the release agent used in the release treatment include fluorine-based, alkyd-based, silicone-based, unsaturated polyester-based, polyolefin-based, and wax-based release agents.

The release sheet 13 may also be provided with an antistatic layer on one surface or both surfaces thereof. In addition, the above-mentioned release treatment and the antistatic layer may be performed on the surface of the same side of the release sheet 13, and in this case, after the antistatic layer is provided, the release treatment is performed on the antistatic layer. This antistatic layer may be a known antistatic layer, for example, can be formed of the same antistatic layer composition as that used to form the antistatic layer on the substrate 11 . Furthermore, the thickness of the antistatic layer of the release sheet 13 is not particularly limited, and may have the same thickness as the antistatic layer on the base material 11 .

Furthermore, the release sheet 13 is also preferably provided with antistatic properties through the above-mentioned method. Thereby, it becomes easy to reduce the peeling static electricity voltage of the adhesive sheet 1, and suppress the static electricity of the adhesive sheet 1 to the minimum after peeling the peeling sheet 13. From this point of view, the surface resistivity of the release sheet 13 on the side in contact with the adhesive layer is preferably not more than 1×10 ¹² Ω/sq, particularly preferably not more than 1×10 ¹¹ Ω/sq. , and more preferably not more than 1×10 ¹⁰ Ω/sq. In addition, the lower limit of the above-mentioned surface resistivity is not particularly limited, but it is preferably not less than about 1×10 ⁷ Ω/sq. In addition, the detail of the measurement method of the said surface resistivity and the said peeling electrostatic voltage is as described in the test example mentioned later.

There is no particular limitation on the thickness of the peeling sheet 13 , but it is usually preferably at least 15 μm, and particularly preferably at least 25 μm. Furthermore, the thickness is generally preferably less than 100 μm, and particularly preferably less than 75 μm.

2. Physical properties of the adhesive sheet (1) Total light transmittance The adhesive sheet 1 of this embodiment preferably has a total light transmittance (total light transmittance of a laminate obtained by peeling and removing the release sheet 13 when the adhesive sheet 1 includes the release sheet 13) of 80% or more. More than 85% is particularly preferable, and more than 90% is more preferable. By making the above-mentioned total light transmittance 80% or more, the adhesive sheet 1 according to this embodiment becomes easy to achieve excellent transparency, and is very suitable as a protective sheet requiring high transparency, such as a protective sheet for OLED devices. The upper limit of the above-mentioned total light transmittance is not particularly limited, and is preferably less than 100%, particularly preferably less than 98%, and more preferably less than 94%. In addition, the above-mentioned total light transmittance is measured according to JIS K7361-1:1997 and ASTM D 1003, and the detailed measurement method is as described in the test examples described later.

(2) Haze (Haze) value The adhesive sheet 1 of this embodiment preferably has a haze value (in the case where the adhesive sheet 1 includes the release sheet 13, the haze value of the laminate obtained by peeling and removing the release sheet 13) of 4% or less, preferably 3%. % or less is preferable, 2% or less is especially preferable, and 1.5% or less is more preferable. By making the above-mentioned haze value 4% or less, the adhesive sheet 1 according to this embodiment can achieve excellent transparency, and becomes very suitable as a protective sheet requiring high transparency, such as a protective sheet for OLED devices. The lower limit of the haze value is not particularly limited, but is preferably at least 0.1%, particularly preferably at least 0.2%, and more preferably at least 0.3%. In addition, the above-mentioned haze value is measured according to JIS K7136:2000 and ASTM D 1003, and the detailed measurement method thereof is described in the test examples described later.

(3) Adhesion According to the adhesive sheet 1 of this embodiment, after the surface of the adhesive layer 12 on the opposite side to the substrate 11 (hereinafter sometimes referred to as "adhesive surface") is attached to soda-lime glass (soda-lime glass), the The adhesive force measured when peeling the adhesive sheet from the above-mentioned soda-lime glass at a peeling speed of m/min is preferably 10 mN/25mm or higher, particularly preferably 20 mN/25 mm or higher, and more preferably 25 mN/25 mm or higher. By making this adhesive force 10 mN/25mm or more, it can suppress that the adhesive sheet 1 peels unexpectedly from an adherend. Furthermore, the above-mentioned adhesive force is preferably less than 300mN/25mm, more preferably less than 200mN/25mm, particularly preferably less than 100mN/25mm, and more preferably less than 50mN/25mm. By making this adhesive force 300 mN/25mm or less, the adhesive sheet 1 becomes easy to realize the outstanding removability.

Furthermore, according to the adhesive sheet 1 of the present embodiment, after the adhesive surface is attached to the soda lime glass, the adhesive force measured when the adhesive sheet is peeled off from the above soda lime glass at a peeling speed of 2.0 m/min, More than 20mN/25mm is preferable, more than 30mN/25mm is especially preferable, and more preferably 40mN/25mm or more. Furthermore, the above-mentioned adhesive force is preferably less than 400mN/25mm, more preferably less than 300mN/25mm, particularly preferably less than 200mN/25mm, and more preferably less than 100mN/25mm. In the case of using the adhesive sheet 1 according to the embodiment of the present application as such a protective sheet, since the adhesive force at the time of peeling at a peeling speed of 2.0 m/min is within the above-mentioned range, it becomes easy to achieve particularly excellent removal. sex.

In addition, the said adhesive force is measured based on JIS Z0237:2009, and the detailed measurement method is as described in the test example mentioned later.

According to the adhesive sheet 1 of this embodiment, the difference between the adhesive force measured when peeled at a peeling speed of 0.3 m/min and the adhesive force measured when peeled at a peeling speed of 2.0 m/min is small better. Specifically, the absolute value of the difference between the adhesive force when the peeling speed is 2.0m/min and the adhesive force when the peeling speed is 0.3m/min is preferably 200mN/25mm or less, and 100mN/25mm or less. Good, and less than 50mN/25mm is better. Since the difference in the adhesive force is within such a range, the adhesive sheet 1 is easy to be firmly fixed on the adherend during use and easy to peel off after use. In addition, the lower limit of the above-mentioned absolute value is not particularly limited, for example, it is preferably 1 mN/25 mm or more, particularly preferably 10 mN/25 mm or more.

(4) Peeling force According to the adhesive sheet 1 of the present embodiment, after the adhesive surface is attached to the polyethylene terephthalate film, the adhesive sheet is peeled off from the polyethylene terephthalate film at a peeling speed of 0.3 m/min. The peel force measured during peeling is preferably below 100mN/25mm, particularly preferably below 70mN/25mm, and more preferably below 50mN/25mm. By making this peeling force 100 mN/25mm or less, it becomes possible to peel the adhesive sheet 1 from an adherend more easily, and it becomes easy to realize excellent removability. Furthermore, the above-mentioned peeling force is preferably at least 5 mN/25 mm, particularly preferably at least 10 mN/25 mm, and more preferably at least 15 mN/25 mm. When this peeling force is 5 mN/25 mm or more, it is possible to make tunneling difficult to occur.

Furthermore, according to the adhesive sheet 1 of the present embodiment, after the adhesive surface is attached to the polyethylene terephthalate film, the adhesive sheet is peeled from the polyethylene terephthalate film at a peeling speed of 2.0 m/min. The peeling force measured when the diester film is peeled is preferably not more than 200 mN/25 mm, particularly preferably not more than 150 mN/25 mm, and more preferably not more than 100 mN/25 mm. Furthermore, the above-mentioned peeling force is preferably at least 10 mN/25 mm, particularly preferably at least 20 mN/25 mm, and more preferably at least 30 mN/25 mm. When this peeling force is 10 mN/25 mm or more, it is possible to make tunneling less likely to occur. Since the peeling force at the time of peeling at a peeling speed of 2.0 m/min is below the above-mentioned upper limit, when the adhesive sheet 1 according to the embodiment of the present application is peeled from the adherend, it needs to be peeled quickly without requiring a large amount of force. In the case of a peelable protective sheet (for example, a protective sheet for flexible devices), particularly excellent removability becomes easy to achieve.

In addition, the peeling force mentioned above was measured based on JIS Z0237:2009, and the detailed measurement method is as described in the test example mentioned later.

Furthermore, when the adhesive sheet 1 is used for an adherend that is particularly susceptible to static electricity, or in an environment where dust or the like is present, the adhesive sheet 1 is preferably one that can suppress peeling static electricity. From this point of view, the peeling electrostatic voltage of the adhesive sheet 1 is preferably 0.2 kV or less, and particularly preferably 0.1 kV or less. In addition, the details of the measurement method of the said peeling electrostatic voltage are as described in the test example mentioned later.

3. Manufacturing method of adhesive sheet The method of manufacturing the adhesive sheet 1 according to this embodiment is not particularly limited. For example, after coating a coating solution containing the above-mentioned polysiloxane-based adhesive composition and a diluent as required on the surface of one side of the substrate 11, the obtained coating film is dried and thermally cured to form Adhesive layer 12, whereby the adhesive sheet 1 can be manufactured.

The above-mentioned diluent is not particularly limited, and various diluents can be used. For example, hydrocarbon compounds such as toluene, hexane, and heptane, acetone, ethyl acetate, methyl ethyl ketone, methyl isobutyl ketone, and mixtures thereof can also be used.

Coating of the above-mentioned coating solution of the polysiloxane-based adhesive composition can be carried out by a commonly used method, for example, a bar coating method, a knife coating method, a roll coating method, or a roll coating method can be used. ) method, blade coating method, die coating method, gravure coating method. After applying the above coating solution, it is preferable to heat and dry the coating film.

As conditions for the above-mentioned thermosetting, the heating temperature is preferably 80° C. to 180° C., and the heating time is preferably 10 seconds to 150 seconds.

After the adhesive layer 12 is formed as described above, the release sheet 13 can be bonded to the adhesive layer 12 to obtain the adhesive sheet 1 .

In addition, in the above manufacturing method, the adhesive layer 12 is formed on the base material 11 , but the adhesive layer 12 may be formed on the release sheet 13 , and then the base material 11 may be attached to the adhesive layer 12 .

4. Application of adhesive sheet The use of the adhesive sheet 1 according to this embodiment is not particularly limited, and it is suitable as a protective sheet for preventing scratches on the surface of the device during processing, assembly, inspection, etc. of the device. Furthermore, the adhesive sheet 1 according to this embodiment is also suitable as a protective sheet for end-users (end-users) to attach to displays of electronic devices such as smartphones (smartphones).

According to the adhesive sheet 1 of this embodiment, the adhesive layer is made of a silicone adhesive, and good removability can be realized. Therefore, when the protective adhesive sheet 1 is peeled off from the device, peeling occurs at the interface between the substrate 11 and the adhesive layer 12 , and it is possible to suppress a part of the adhesive layer 12 from remaining on the device. Furthermore, when the adhesive sheet 1 is peeled off from the device, damage or damage to the device can be suppressed.

When using the adhesive sheet 1 as a protective sheet of a device, examples of the device include optical members, electronic members, and the like. In particular, according to the adhesive sheet 1 of this embodiment, the device to be protected is preferably a flexible device. Furthermore, according to the adhesive sheet 1 of the present embodiment, as the device to be protected, a device requiring light emission detection or high temperature conditions in a state where the adhesive sheet 1 is attached is preferable. Therefore, the device protected by the adhesive sheet 1 according to the present embodiment is preferably an OLED device, and is particularly preferably a flexible OLED device.

According to the adhesive sheet 1 of this embodiment, since the arithmetic average roughness (Ra) of the surface on which the adhesive layer 12 is laminated|stacked in the base material 11 falls within the said range, the adhesive sheet 1 as a whole has excellent transparency. Therefore, it is possible to satisfactorily perform light emission detection and the like of the device in a state where the adhesive sheet 1 is attached. In particular, adverse effects on luminescence detection can be well suppressed even for devices that perform luminescence detection at a stricter degree than usual (such as OLED devices).

Furthermore, as described above, according to the adhesive sheet 1 of this embodiment, the surface of the substrate 11 on which the adhesive layer 12 is laminated has the above-mentioned arithmetic mean roughness (Ra) and becomes a surface with high smoothness. However, since the adhesive layer 12 is formed of the silicone-based adhesive composition containing a silane coupling agent, it becomes excellent in adhesiveness at the interface between the substrate 11 and the adhesive layer 12 . Therefore, according to the adhesive sheet 1 of the present embodiment, unintentional peeling at the interface between the base material 11 and the adhesive layer 12 can be suppressed, and when the adhesive sheet 1 is peeled from the adherend, it can be suppressed that only the adhesive The phenomenon that layer 12 remains on the adherend. Furthermore, even when the adhesive sheet 1 of this embodiment is wound into a roll, the occurrence of tunnels that cause peeling at the interface between the base material 11 and the adhesive layer 12 can be suppressed.

[Flexible device with protective sheet] According to the flexible device with a protective sheet of this embodiment, the adhesive sheet 1 according to this embodiment is attached to at least one surface of the flexible device as a protective sheet. Examples of the flexible device of this embodiment include flexible optical members, electronic members, and the like, and a flexible OLED device is particularly preferred.

The embodiments described above are described for easy understanding of the present invention, and are not described for limiting the present invention. Therefore, each element disclosed in the above-mentioned embodiments also covers all design changes and equivalents belonging to the technical scope of the present invention.

For example, another layer (such as an antistatic layer) may be inserted between the substrate 11 and the adhesive layer 12 in the adhesive sheet 1, or other layers may be deposited on the surface of the substrate 11 opposite to the adhesive layer 12. layers (such as antistatic layers). [Example]

Hereinafter, the present invention will be described more specifically through examples and the like, but the scope of the present invention is not limited to these examples and the like.

[Example 1] 1. Preparation of Coating Solution of Silicone Adhesive Composition 100 parts by mass of an addition-reactive silicone resin (manufactured by Shin-Etsu Chemical Co., Ltd., product name "KS-847H") as the main component of the silicone adhesive, 2 parts by mass of a platinum catalyst (Dow Corning Toray (Dow Corning Toray, product name "SRX 212 CATALYST"), 0.25 parts by mass of 3-glycidylpropyltrimethoxysilane (3-glycidoxypropyltrimethoxysilane) as a silane coupling agent, and 15 parts by mass of poly Silicone resin (manufactured by Dow Corning Toray, product name "SD-4584") was mixed and diluted with methyl ethyl ketone to use it as a coating solution of the polysiloxane-based adhesive composition.

2. Fabrication of Adhesive Sheets The coating solution of the silicone-based adhesive composition obtained in the above steps was coated on the surface of one side of the substrate A shown in Table 1 by the knife coating method, and then performed at 130° C. for 2 minutes. heat treatment to form an adhesive layer with a thickness of 25 μm. Next, a polyethylene terephthalate (PET) film (manufactured by Toray Corporation, product name "Lumirror T60", no release agent layer, thickness: 50 μm) as a release sheet was attached to the above adhesive layer , to obtain adhesive sheets.

[Examples 2-14, Comparative Examples 1-5] An adhesive sheet was produced in the same manner as in Example 1 except that the type and amount of the silane coupling agent, the type of base material, and the type of release sheet were changed as shown in Table 2. Moreover, when using the base material C or the base material E which exists the easily-adhesive layer only in the surface of one side, an adhesive agent layer is formed in the surface which exists the easily-adhesive layer.

In addition, regarding the substrates A to E used and the two reference substrates (product names "T100F38" and "T100J"), the types of coating layers included in each substrate, and the following descriptions Table 1 shows the various physical properties measured in the test examples.

In addition, details such as the abbreviations described in Table 2 are as follows. [Release sheet] Lumirror T-60: Polyethylene terephthalate film (manufactured by Toray Corporation, product name "Lumirror T60", no release agent layer, thickness: 50 μm) PET25T-100 (WJ): Polyethylene terephthalate film Ethylene terephthalate film (manufactured by Mitsubishi Plastics Corporation, product name "PET25T-100 (WJ)", thickness: 25 μm, surface resistivity measured according to the test example described later: 2.4×10 ⁹ Ω /sq)

[Test Example 1] (Measurement of Surface Roughness of Substrate) For the substrates shown in Table 1, various surface roughnesses were measured. Specifically, for the surface of the substrate on the side having the above-mentioned layer in which the easy-adhesive layer or the antistatic layer exists, and for the surface on the side of the substrate in which the easily-adhesive layer and the antistatic layer do not exist, according to JIS B601: In 2001, using a light interference microscope (manufactured by Veeco, the product name is "Surface Shape Measuring Device WYKO NT110") to measure the arithmetic average surface roughness (Ra; the unit is nm), the root mean square height (Rq; the unit is nm ), the maximum height (Rz; the unit is nm), and the maximum section height (Rt; the unit is nm). At this time, the measurement conditions PSI and the magnification were set to 50 times, and the average value at 5 measurement points was taken as the value of the surface roughness. The results are shown in Table 1.

[Test Example 2] (Measurement of Surface Resistivity of Substrate, etc.) The surface resistivity (Ω/sq) was measured for the base materials shown in Table 1 and the release sheet of the above-mentioned product name "PET25T-100 (WJ)". Specifically, for the surface of the base material having the above-mentioned layer with the easy adhesion layer or the antistatic layer, and for the surface of the base material without the easy adhesion layer and the antistatic layer, at 23°C, In an environment with a relative humidity of 50%, use a resistivity measuring device (manufactured by Mitsubishi Chemical Analyzer Corporation, product name "Hiresta UP MCP-HT450") to measure the applied resistance to the substrate and release sheet according to JIS K6911:2006. Surface resistivity (Ω/sq) after a voltage of 100V for 10 seconds. The measurement results for the base material are shown in Table 1. In addition, the measurement result about the peeling sheet is as above-mentioned.

[Test Example 3] (Measurement of total light transmittance and haze value of substrate) For the substrates shown in Table 1, the total light transmittance (%) was measured according to JIS K 7361-1:1997 and ASTM D 1003 using a haze meter (manufactured by Nippon Denshoku Kogyo Co., Ltd., NDH7000), and at the same time according to JIS K7136: 2000 and ASTM D 1003, measured haze value (%). The above results are shown in Table 1.

[Test Example 4] (Evaluation of Substrate Adhesion) After the adhesive sheets produced in Examples and Comparative Examples were left to stand for one day under the conditions of 23° C. and 50% RH, the release sheet was peeled off. Next, cross marks (50 mm×50 mm) were engraved on the exposed adhesive layer using a cutter knife. After that, the adhesive layer at the notch was rubbed with the pulp of a finger to confirm the degree of detachment of the adhesive layer, and the substrate adhesion was evaluated according to the following criteria. The results are shown in Table 3. ◯: The adhesive layer did not detach from the substrate, and good adhesion could be maintained. Δ: A part of the adhesive layer was detached from the substrate, but a certain degree of adhesiveness was maintained. X: The entire adhesive layer is detached from the base material, indicating that the adhesiveness is insufficient.

Furthermore, the adhesive sheets produced in Examples and Comparative Examples were left to stand for 7 days at 85°C and 85%RH, and the adhesive sheets produced in Examples and Comparative Examples were placed at 60°C and 90%RH. Under the condition of 7 days, each substrate adhesion was also evaluated in the same manner as above. The above results are also shown in Table 3.

[Test Example 5] (Measurement of total light transmittance and haze value of adhesive sheet) The release sheet was peeled off from the adhesive sheet produced in Examples and Comparative Examples, and the total light transmittance was measured according to JIS K 7361-1:1997 and ASTM D 1003 using a haze meter (manufactured by Nippon Denshoku Industries, Ltd., NDH7000) rate (%), and at the same time according to JIS K7136: 2000 and ASTM D 1003, measure the haze value (%). The above results are shown in Table 3.

In addition, two types of adhesive sheets were produced in the same manner as in Example 1 using instruments with product names "T100F38" and "T100J" as substrates, and their haze values (%) were measured. As a result, either more than 4%.

[Test Example 6] (Measurement of Adhesive Force) The adhesive sheets produced in the examples and comparative examples were cut into lengths of 100 mm and widths of 25 mm. Next, the peeling sheet was peeled off from the above-mentioned adhesive sheet, and the exposed surface of the exposed adhesive layer was pressed against the soda-lime glass at 0.5 MPa and 50° C. for 20 minutes, and then attached to the soda-lime glass. Thereafter, a sample for adhesive force measurement was obtained by standing in a standard environment (23° C., 50% RH) for 24 hours.

For the above-mentioned samples for adhesion measurement, according to JIS Z0237:2009, use a tensile tester (manufactured by Orientech, product name "TENSILON UTM-4-100") under a standard environment (23°C, 50%RH) , measure the force when the adhesive sheet is peeled from the soda lime glass at a peeling angle of 180° and a peeling speed of 0.3 m/min, and set it as the adhesive force (mN/25mm). The results are shown in Table 3.

Furthermore, for the sample for measurement of adhesion obtained in the same manner as above, a tensile tester (manufactured by Orientech Corporation, product named "TENSILON UTM-4-100"), measured the force when peeling the adhesive sheet from the soda lime glass at a peeling angle of 180° and a peeling speed of 2.0m/min, and set it as the adhesive force (mN/25mm ). The results are shown in Table 3.

[Test Example 7] (Measurement of Peeling Force) The adhesive sheets produced in Examples and Comparative Examples were cut into lengths of 100 mm and widths of 25 mm. Then, by fixing the surface of the base material side of this adhesive sheet on a stainless steel (stainless steel) plate, a sample for peeling force measurement was obtained.

For the above-mentioned peel force measurement sample, a tensile tester (manufactured by Orientech, product name "TENSILON UTM-4-100") was used under a standard environment (23°C, 50%RH) according to JIS Z0237:2009. , the force when the peeling sheet was peeled from the adhesive sheet at a peeling angle of 180° and a peeling speed of 0.3 m/min was measured, and this was defined as the peeling force (mN/25mm). The results are shown in Table 3.

Furthermore, for the sample for peel force measurement obtained in the same manner as above, a tensile tester (manufactured by Orientech Corporation, product named "TENSILON UTM-4-100"), measured the force when the release sheet is peeled from the adhesive sheet at a peel angle of 180° and a peel speed of 2.0m/min, and set it as the peel force (mN/25mm) . The results are also shown in Table 3.

[Test Example 8] (Tunnel Evaluation) The adhesive sheets manufactured in Examples and Comparative Examples were wound on a cylindrical plastic tube with a diameter of 7.62 cm to obtain an adhesive sheet roll. At this time, the adhesive sheet was wound until the surface of the base material side of the adhesive sheet was located inside and the diameter of the obtained adhesive sheet roll became 50 cm.

The adhesive sheet roll obtained as described above was left to stand under the conditions of 23° C. and 65% RH for one week without the adhesive sheet touching the ground. After that, the state at the interface between the adhesive layer and the release sheet was confirmed, and the tunnel was evaluated according to the following criteria. The results are shown in Table 3. ◯: Peeling did not occur at the interface between the adhesive layer and the release sheet. x: Peeling occurred at the interface between the adhesive layer and the peeling sheet.

[Test Example 9] (Evaluation of peeling static electricity) The adhesive sheet manufactured in the Example and the comparative example was cut into 25 mm*100 mm, and it was used as a sample. Under the environment of 23 ℃ and 50%RH, the peeling sheet is peeled off from the sample at a peeling speed of 2.0m/min by hand, and 5 seconds after peeling off, use an electrostatic measuring device (manufactured by Simco Corporation of Japan, product name "FMX-003"), the electrostatic potential (peeling electrostatic voltage; V) at a position 2.0 cm from the exposed surface of the adhesive layer was measured. From the measurement results, the peel electrostatic voltage on the surface of the adhesive layer was evaluated according to the following criteria. The results are shown in Table 3. ◯: The peeling electrostatic voltage is 0.1 kV or less. Δ: The peeling electrostatic voltage exceeds 0.1 kV and is 0.2 kV or less. ×: The peeling electrostatic voltage exceeds 0.2 kV.

[Table 1]

[table 3]

It can be clearly seen from Table 3 that the adhesive sheet produced in the examples has good removability and the adhesive layer also has excellent adhesion to the substrate. [industrial availability]

The adhesive sheet according to the present invention is suitable as a protective sheet used in the process of processing, assembling, inspecting and the like of a flexible OLED device.

1‧‧‧adhesive sheet 11‧‧‧Substrate 12‧‧‧adhesive layer 13‧‧‧Peeling sheet

[ Fig. 1 ] is a cross-sectional view of an adhesive sheet according to an embodiment of the present invention.

1‧‧‧adhesive sheet

11‧‧‧Substrate

12‧‧‧adhesive layer

13‧‧‧Peeling sheet

Claims (7)

An adhesive sheet comprising a base material and an adhesive layer laminated on one surface of the base material, characterized in that the arithmetic mean roughness (Ra ) is less than 25 nm, and the aforementioned adhesive layer is composed of the first polydimethylsiloxane containing at least 2 alkenyl groups in one molecule and the second polydimethylsiloxane containing at least two hydrosilyl groups in one molecule It is composed of an addition reaction polysiloxane resin obtained from an alkane, a polysiloxane adhesive containing a platinum catalyst, and a polysiloxane adhesive composition containing a silane coupling agent. The adhesive layer and the substrate are After the surface on the opposite side is attached to the soda-lime glass, the adhesive force measured when the aforementioned adhesive sheet is peeled from the above-mentioned soda-lime glass at a peeling speed of 0.3m/min is 10mN/25mm or more and 300mN/25mm or less. After the surface of the adhesive layer on the opposite side to the aforementioned substrate is attached to the soda-lime glass, the adhesive force measured when the aforementioned adhesive sheet is peeled from the above-mentioned soda-lime glass at a peeling speed of 2.0m/min is 20mN/ Above 25mm, below 400mN/25mm. The adhesive sheet described in claim 1, wherein the content of the silane coupling agent is not less than 0.001 parts by mass and not more than 3.0 parts by mass relative to 100 parts by mass of the aforementioned addition-reactive polysiloxane resin. The adhesive sheet as described in claim 1 of the patent application, wherein the silicone adhesive contains silicone resin. The adhesive sheet described in claim 3, wherein the content of the silicone resin is not less than 1 part by mass and not more than 40 parts by mass relative to 100 parts by mass of the aforementioned addition-reactive silicone resin. The adhesive sheet described in claim 1 of the patent application, wherein the haze value of the aforementioned substrate is 3.5% or less. The adhesive sheet described in claim 1 of the patent application is used as a protective sheet for protecting a device. The adhesive sheet as described in claim 6 of the patent application, wherein the aforementioned device is a flexible device.

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