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WO2025028263A1 - Stratifié optique - Google Patents

Stratifié optique Download PDF

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Publication number
WO2025028263A1
WO2025028263A1 PCT/JP2024/025633 JP2024025633W WO2025028263A1 WO 2025028263 A1 WO2025028263 A1 WO 2025028263A1 JP 2024025633 W JP2024025633 W JP 2024025633W WO 2025028263 A1 WO2025028263 A1 WO 2025028263A1
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WO
WIPO (PCT)
Prior art keywords
film
layer
polarizer
group
retardation
Prior art date
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Pending
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PCT/JP2024/025633
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English (en)
Japanese (ja)
Inventor
亨 神野
健次 松野
幸司 住田
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Sumitomo Chemical Co Ltd
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Sumitomo Chemical Co Ltd
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Publication date
Priority claimed from JP2024016970A external-priority patent/JP2025022695A/ja
Application filed by Sumitomo Chemical Co Ltd filed Critical Sumitomo Chemical Co Ltd
Publication of WO2025028263A1 publication Critical patent/WO2025028263A1/fr
Pending legal-status Critical Current
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    • 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
    • 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
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B5/00—Optical elements other than lenses
    • G02B5/30—Polarising elements
    • H—ELECTRICITY
    • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
    • H10K50/00—Organic light-emitting devices
    • H10K50/80—Constructional details
    • H10K50/86—Arrangements for improving contrast, e.g. preventing reflection of ambient light
    • H—ELECTRICITY
    • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
    • H10K59/00—Integrated devices, or assemblies of multiple devices, comprising at least one organic light-emitting element covered by group H10K50/00
    • H10K59/10—OLED displays

Definitions

  • the present invention relates to an optical laminate.
  • Patent Document 1 discloses an optical laminate including a structure for protecting the polarizer. Specifically, the optical laminate disclosed in Patent Document 1 has a polarizer protective film for protecting the polarizer laminated on a polarizer.
  • an optical laminate having the above-described structure for protecting a polarizer causes the edge of the polarizer to swell in a high-temperature environment.
  • an optical laminate that can suppress the occurrence of this phenomenon.
  • the present invention includes the following inventions.
  • An optical laminate including an optical film including a pressure-sensitive adhesive layer, a polarizer in which a dichroic dye is adsorbed and oriented on a polyvinyl alcohol-based resin film, a first attachment layer, a retardation plate, and a second attachment layer in this order, the pressure-sensitive adhesive layer side of the optical film is in direct contact with the polarizer, The polarizer and the first attachment layer are in direct contact with each other,
  • An optical laminate, wherein a layer constituted by the first bonding layer, the retardation plate, and the second bonding layer has an absorbance of 0.1 or more for light having a wavelength of 340 nm.
  • the luminosity-corrected single transmittance of the polarizer is 41% or more, The optical laminate according to [Invention 1] or [Invention 2], wherein the polarizer has a luminosity-corrected polarization degree of 99.5% or more.
  • [Invention 5] The optical laminate according to any one of [Invention 1] to [Invention 4], wherein the retardation plate is a ⁇ /4 retardation plate exhibiting reverse wavelength dispersion.
  • the optical laminate of the present invention can prevent the ends of the polarizer from swelling up.
  • FIG. 1 is a cross-sectional view showing the layer structure of one embodiment of an optical laminate.
  • FIG. 2 is a cross-sectional view showing the layer structure of another example of the optical laminate.
  • FIG. 3 is an explanatory diagram for explaining the microscopic Raman spectroscopic analysis of the polarizing plate according to the present embodiment.
  • FIG. 4 is a schematic diagram illustrating an evaluation sample for performing an end swelling test.
  • FIG. 5 is a graph showing an example of the measurement results in the edge swelling test.
  • FIG. 1 is a schematic cross-sectional view illustrating a layer configuration of an optical laminate 1 of the present embodiment.
  • FIG. 2 shows an optical stack 2 comprising an image display element 40 .
  • the optical laminate 1 includes an optical film 109 including a pressure-sensitive adhesive layer, a polarizer 101, a first bonding layer 30a, a retardation plate 20, and a second bonding layer 30b in this order.
  • a surface protection film for protecting the surface of the polarizer 101 is provided as an optical film having a pressure-sensitive adhesive layer.
  • the surface protection film is an optical film in which a pressure-sensitive adhesive layer is formed on the surface of a resin film for a surface protection film.
  • the optical film on which the pressure-sensitive adhesive layer is formed corresponds to the optical film including the pressure-sensitive adhesive layer.
  • the surface protection film may be a self-adhesive optical film. In this case, the self-adhesive optical film corresponds to the optical film including the pressure-sensitive adhesive layer.
  • the surface protection film is configured so that it can be peeled off together with the adhesive layer from the polarizer 101.
  • the optical laminate 1 is used in a state where the surface protection film is removed together with the adhesive layer.
  • the surface protection film is configured so that the resin film for the surface protection film can be peeled off while the adhesive layer remains attached to the polarizer 101.
  • the optical laminate 1 is used in a state in which the resin film for the surface protection film is removed and the adhesive layer is laminated on the polarizer 101.
  • the adhesive layer laminated on the polarizer 101 after the resin film for the surface protection film is removed is used to bond the optical laminate 1 to a component disposed on the opposite side of the polarizer 101 from the retardation film 20.
  • the adhesive layer is different from a protective layer that may be laminated on the polarizer for the purpose of protecting the polarizer.
  • An example of the component disposed on the opposite side of the polarizer 101 from the retardation film 20 is a front plate.
  • the optical film 109 including the pressure-sensitive adhesive layer is in direct contact with the polarizer 101 via the pressure-sensitive adhesive layer. Furthermore, in the optical laminate 1, the surface of the polarizer 101 opposite to the surface in direct contact with the optical film 109 via the pressure-sensitive adhesive layer is in direct contact with the first bonding layer 30a. That is, the optical laminate 1 does not include a protective film (hereinafter sometimes referred to as a "polarizer protective film") or a protective layer that protects the polarizer 101.
  • the polarizer protective film is used in the optical laminate in a state where it is laminated on the polarizer, and is different from the optical film 109 including the adhesive layer that peels off during use.
  • the protective layer is also used in the optical laminate in a state where it is laminated on the polarizer.
  • the protective layer is different from the adhesive layer that remains laminated on the polarizer 101 after the resin film for the surface protective film is removed from the surface protective film.
  • the polarizer protective film and the protective layer are different from the optical film 109 including the adhesive layer that peels off during use.
  • thermoplastic resin film is used as the polarizer protective film.
  • the polarizer protective film is laminated to the polarizer, for example, by the self-adhesiveness of the protective film.
  • the polarizer protective film is laminated, for example, via an adhesive layer or a pressure-sensitive adhesive layer.
  • a polymer with a high crosslinking density is used as the protective layer.
  • Another example of a protective layer is a water-soluble polymer with high hydrophilic interaction.
  • the protective layer is laminated to the polarizer without an adhesive layer or pressure-sensitive adhesive layer.
  • the optical laminate 1 may have one or more other layers between the first bonding layer 30a, the retardation film 20, and the second bonding layer 30b.
  • the other layers that the optical laminate 1 may have are other than the polarizer protective film and the protective layer.
  • the retardation plate 20 includes, for example, a first liquid crystal cured layer 201, a third bonding layer 30c, and a second liquid crystal cured layer 202, in that order from the polarizer 101 side.
  • the retardation plate 20 is preferably a ⁇ /4 retardation plate exhibiting reverse wavelength dispersion, which will be described later.
  • the optical laminate 2 includes a polarizer 101, a first bonding layer 30a, a retardation plate 20, and a second bonding layer 30b on the viewing side of the image display element 40.
  • the polarizer 101, the first bonding layer 30a, the retardation plate 20, the second bonding layer 30b, and the image display element 40 are arranged in this order.
  • the layers laminated on the viewing side of the image display element 40 can be the same as those in the optical laminate 1.
  • the optical laminate 2 including the image display element 40 may further include an optical film 109 including an adhesive layer that is in direct contact with the polarizer 101, as in the optical laminate 1 shown in FIG. 1.
  • the thickness from the surface of the polarizer 101 on the optical film 109 side including the adhesive layer to the surface of the second bonding layer 30b opposite the retardation plate 20 is, for example, 20 ⁇ m or more and 50 ⁇ m or less.
  • the upper limit of the above range is preferably 48 ⁇ m, more preferably 40 ⁇ m.
  • the lower limit of the above range is preferably 25 ⁇ m, more preferably 28 ⁇ m.
  • the thickness of the optical laminate can be reduced by not providing a protective film or protective layer that protects the polarizer 101.
  • the thickness of the optical laminate can be reduced by using an optically anisotropic layer described later as a layer that exhibits retardation, compared to the case of using a retardation film.
  • the phenomenon in which the ends of a polarizer swell in a high-temperature environment is thought to be caused by the difference between the shrinkage rate of the polarizer and the shrinkage rate of the protective film. Specifically, the ends swell because the shrinkage of the polarizer is greater than the shrinkage of the protective film. For example, if a protective film is placed on the surface of the polarizer opposite the viewing side of the optical laminate, warping toward the polarizer is likely to occur, making the ends more likely to swell.
  • the optical laminate of this embodiment does not include a protective film or protective layer to protect the polarizer 101 (hereinafter, sometimes referred to as a "bare film"), and therefore the bulging of the end of the polarizer 101 can be suppressed.
  • the optical laminate 1 of this embodiment is formed by stacking the polarizer 101, the first bonding layer 30a, and the retardation plate 20 in this order. Furthermore, in the optical laminate 1 of this embodiment, the polarizer 101 and the first bonding layer 30a are in direct contact with each other. This makes it easier for the first bonding layer 30a to follow the shrinkage of the polarizer 101. This makes it possible to suppress the bulging of the end of the polarizer 101.
  • the inventors have also confirmed that in an optical laminate bonded to an image display element, the longer the distance from the image display element to the polarizer, the more likely the end bulges are to occur.
  • the thickness of the optical laminate can be reduced as described above, thereby shortening the distance from the image display element to the polarizer. This makes it possible to further suppress end bulges.
  • the layer formed by the first bonding layer 30a, the retardation film 20, and the second bonding layer 30b has an absorbance for light with a wavelength of 340 nm of, for example, 0.1 or more and 5 or less.
  • the upper limit of the absorbance is preferably 4.5, more preferably 3.5, even more preferably 3.0, and particularly preferably 2.5.
  • the lower limit of the absorbance is preferably 0.5, more preferably 1.0, and even more preferably 2.0.
  • the absorbance measured including the other layers is within the above range.
  • a known optical laminate contains an ultraviolet absorber and a light stabilizer in a protective film or layer that protects the polarizer. That is, the protective film or layer is used to impart weather resistance to the optical laminate.
  • the optical laminate of this embodiment does not have a protective film or layer that protects the polarizer 101, but the layer composed of the first bonding layer 30a, the retardation plate 20, and the second bonding layer 30b has an absorbance of 0.1 or more for light with a wavelength of 340 nm. This makes it difficult for the luminosity-corrected polarization degree Py in the optical laminate to decrease over time, so the optical laminate of this embodiment has excellent weather resistance even though it is a bare film.
  • the optical laminate of this embodiment is able to suppress degradation due to ultraviolet light, even though it is a bare film. This makes it possible to suppress a decrease in the luminosity-corrected polarization degree Py that can occur due to degradation due to ultraviolet light.
  • the optical laminate of this embodiment which does not have a protective film or layer to protect the polarizer 101, if the absorbance is 5 or more, degradation due to heat becomes noticeable in a weather resistance test.
  • the optical laminate of this embodiment is a bare film, but can suppress degradation due to heat. Therefore, it is possible to suppress an increase in the luminous efficacy-corrected single transmittance Ty and a decrease in the luminous efficacy-corrected polarization degree Py that can occur due to degradation due to heat.
  • the optical laminate 1 it is preferable that at least one of the first bonding layer 30a, the retardation film 20, and the second bonding layer 30b has ultraviolet absorbing properties.
  • the first bonding layer 30a has ultraviolet absorbing properties.
  • the decrease in the visibility-corrected polarization degree Py in the optical laminate is likely to be suppressed.
  • the layer disposed between the polarizer 101 and the retardation film 20 can absorb ultraviolet rays, thereby suppressing deterioration of the retardation film 20.
  • the polarizer 101 is an optical film (linear polarizer) that has the property of transmitting linearly polarized light having a vibration plane perpendicular to the absorption axis when unpolarized light is incident on the polarizer 101.
  • the polarizer 101 is a polyvinyl alcohol-based resin film (hereinafter also referred to as a "PVA-based film”) in which a dichroic dye is adsorbed and oriented.
  • the polyvinyl alcohol resin (hereinafter also referred to as "PVA resin”) that constitutes the PVA film can be produced by saponifying a polyvinyl acetate resin.
  • the polyvinyl acetate resin can also be a copolymer of vinyl acetate and other monomers that can be copolymerized with vinyl acetate.
  • examples of other monomers that can be copolymerized with vinyl acetate include unsaturated carboxylic acids, olefins, vinyl ethers, unsaturated sulfonic acids, and (meth)acrylamides having an ammonium group.
  • (meth)acrylic means that it can be either acrylic or methacrylic.
  • the "(meth)" in (meth)acrylate, etc. has the same meaning.
  • the degree of saponification of PVA-based resins is usually about 85 to 100 mol%, and preferably 98 mol% or more.
  • the PVA-based resins may be modified; for example, polyvinyl formal or polyvinyl acetal modified with aldehydes may be used.
  • the average degree of polymerization of PVA-based resins is usually about 1000 to 10,000, and preferably about 1500 to 5,000.
  • the average degree of polymerization of PVA-based resins can be determined in accordance with JIS K 6726 (1994). If the average degree of polymerization is less than 1000, it is difficult to obtain favorable polarizing performance, and if it exceeds 10,000, the film processability may be poor.
  • the polarizer 101 is usually manufactured through a process of uniaxially stretching a PVA-based film, a process of dyeing the PVA-based film with a dichroic dye to adsorb the dichroic dye, a process of treating the PVA-based film with the adsorbed dichroic dye with an aqueous boric acid solution to crosslink the film, and a process of washing the film with water after the crosslinking process with the aqueous boric acid solution (hereinafter referred to as boric acid treatment).
  • Uniaxial stretching of PVA-based films can be performed before, simultaneously with, or after dyeing with a dichroic dye. If uniaxial stretching is performed after dyeing, it may be performed before or during the boric acid treatment. Of course, uniaxial stretching can be performed in multiple stages as shown here. For uniaxial stretching, a method of uniaxial stretching in the film transport direction between rolls with different peripheral speeds, a method of uniaxial stretching in the film transport direction using a heated roll, or a method of stretching in the width direction using a tenter can be used. Moreover, uniaxial stretching can be performed by dry stretching in the air, or by wet stretching in which the PVA-based film is stretched in a swollen state using a solvent such as water. The stretching ratio is usually about 3 to 8 times.
  • the dyeing of a PVA-based film with a dichroic dye can be carried out, for example, by immersing the PVA-based film in an aqueous solution containing the dichroic dye.
  • the dichroic dye that can be used include iodine and dichroic organic dyes. It is preferable to immerse the PVA-based film in water to cause it to swell before the dyeing process.
  • iodine When iodine is used as the dichroic dye, a method is usually used in which the PVA-based film is immersed in an aqueous solution containing iodine and potassium iodide to dye it.
  • the iodine content in this aqueous solution is usually about 0.01 to 1 part by mass per 100 parts by mass of water
  • the potassium iodide content is usually about 0.5 to 20 parts by mass per 100 parts by mass of water.
  • the temperature of the aqueous solution used for dyeing is usually about 20 to 40°C.
  • the immersion time in this aqueous solution (dyeing time) is usually about 20 to 1,800 seconds.
  • a method is usually adopted in which the PVA-based film is immersed in an aqueous solution containing a water-soluble dichroic organic dye for dyeing.
  • the content of the dichroic organic dye in this aqueous solution is usually about 0.0001 to 10 parts by mass, and preferably 0.001 to 1 part by mass, per 100 parts by mass of water.
  • This aqueous dye solution may contain an inorganic salt such as sodium sulfate as a dyeing assistant.
  • the temperature of the aqueous dichroic organic dye solution used for dyeing is usually about 20 to 80°C.
  • the immersion time in this aqueous solution (dyeing time) is usually about 10 to 1,800 seconds.
  • the boric acid treatment after dyeing with a dichroic dye can be carried out by immersing the dyed PVA-based film in a boric acid-containing aqueous solution.
  • the content of boric acid in the boric acid-containing aqueous solution is usually about 2 to 15 parts by mass, preferably 5 to 12 parts by mass, per 100 parts by mass of water.
  • this boric acid-containing aqueous solution contains potassium iodide.
  • the content of potassium iodide in the boric acid-containing aqueous solution is usually about 0.1 to 15 parts by mass, preferably 5 to 12 parts by mass, per 100 parts by mass of water.
  • the immersion time in the boric acid-containing aqueous solution is usually about 60 to 1,200 seconds, preferably 150 to 600 seconds, and more preferably 200 to 400 seconds.
  • the temperature of the boric acid-containing aqueous solution is usually 50°C or higher, preferably 50 to 85°C, and more preferably 60 to 80°C.
  • the PVA-based film after the boric acid treatment is usually washed with water.
  • the washing can be carried out, for example, by immersing the boric acid-treated PVA-based film in water.
  • the temperature of the water used in the washing is usually about 5 to 40°C.
  • the immersion time is usually about 1 to 120 seconds.
  • the polarizer 101 is obtained by drying.
  • the drying can be performed using a hot air dryer or a far infrared heater.
  • the temperature of the drying is usually about 30 to 100°C, and preferably 50 to 80°C.
  • the time of the drying is usually about 60 to 600 seconds, and preferably 120 to 600 seconds.
  • the moisture content in the polarizer 101 is reduced to a practical level by the drying.
  • the moisture content is usually about 5 to 20 mass% with respect to the total mass of the polarizer 101, and preferably 8 to 15 mass%. If the moisture content is 5 mass% or more, the polarizer 101 has sufficient flexibility, and therefore damage or breakage after drying can be suppressed. If the moisture content is 20 mass% or less, the polarizer 101 has sufficient thermal stability.
  • the polarizer 101 in which the dichroic dye is adsorbed and oriented in the PVA-based film can be manufactured.
  • the polarizer 101 has a boron content of preferably 0.5% by mass or more, more preferably 1.5% by mass or more, even more preferably 2.5% by mass or more, and may be 3.5% by mass or more.
  • the boron content of the polarizer 101 is in the above numerical range, polyvinyl alcohol molecular chains tend to be crosslinked with boric acid, that is, the polarizer 101 tends to have a high degree of crosslinking.
  • the weather resistance of the polarizer 101 can be improved.
  • the optical laminate 1 can be easily used in a state where the surface protective film as the optical film 109 including the pressure-sensitive adhesive layer is removed.
  • the boron content of the polarizer 101 is preferably 5.5% by mass or less, more preferably 5.0% by mass or less, and even more preferably 4.5% by mass or less. When the boron content is 4.5% by mass or less, the shrinkage of the polarizer 101 caused by heating can be suppressed.
  • the "boric acid crosslinking index" of the polarizer 101 used in this embodiment is preferably high from the viewpoint of durability.
  • the boric acid crosslinking index is preferably 0.5 or more, more preferably 0.8 or more, even more preferably 1.0 or more, and even more preferably 1.2 or more.
  • the "boric acid crosslinking index” means an index that indicates the extent to which polyvinyl alcohol molecular chains are crosslinked with boric acid in a polarizer made of a polyvinyl alcohol resin film or the like.
  • the boric acid crosslinking index can be adjusted by changing the manufacturing conditions of the polarizer, such as the content of boric acid in the boric acid-containing aqueous solution, the temperature of the boric acid-containing aqueous solution, and the temperature of the drying process.
  • the boric acid crosslinking index of the polarizer 101 can be determined by performing microscopic Raman spectroscopy.
  • a laser Raman spectrophotometer product name: "NRS-5100", manufactured by JASCO Corporation
  • the Raman scattered light intensities at these wavenumbers are divided (Raman scattered light intensity at wavenumber 780 cm -1 / Raman scattered light intensity at wavenumber 850 cm -1 ) to calculate the boric acid crosslinking index.
  • FIG. 3 is an explanatory diagram for explaining the microscopic Raman spectroscopy analysis of the polarizing plate according to the present embodiment.
  • the laser light is incident on the end face of the polarizer 101 so that the traveling direction of the laser light X and the absorption axis direction of the polarizer 101 are perpendicular to each other.
  • the laser light X is polarized in the thickness direction of the polarizer 101.
  • the measurement position of the laser light is set to the center position in the thickness direction of the polarizer 101. It is preferable to perform cross-sectional processing of the polarizing plate using a microtome before the Raman spectroscopy measurement.
  • the Raman scattered light intensity at a wave number of 780 cm ⁇ 1 means the Raman scattered light intensity attributable to the bond between polyvinyl alcohol and boron
  • the Raman scattered light intensity at a wave number of 850 cm ⁇ 1 means the Raman scattered light intensity attributable to polyvinyl alcohol.
  • the various conditions used in the above-mentioned microscopic Raman spectroscopic analysis are as follows: Excitation wavelength: 532 nm Grating: 600 l/mm Slit width: 100 x 1000 ⁇ m Aperture: ⁇ 40 ⁇ m Objective lens: 100x Objective lens: 100x
  • the luminosity-corrected polarization degree Py of the polarizer 101 is usually 95% or more, preferably 97% or more, more preferably 98% or more, even more preferably 98.7% or more, even more preferably 99.0% or more, particularly preferably 99.4% or more, and may be 99.9% or more.
  • the luminosity-corrected polarization degree Py of the polarizer may be 99.99% or less.
  • the luminosity-corrected polarization degree Py can be calculated by performing luminosity correction on the obtained polarization degree using a spectrophotometer with an integrating sphere ("V7100" manufactured by JASCO Corporation) with a 2-degree visual field (C light source) of "JIS Z 8701".
  • Increasing the luminosity-corrected polarization degree Py of the polarizer 101 is advantageous in terms of improving the function of the circular polarizer as an antireflection film and the durability of the circular polarizer. If the luminosity-corrected polarization degree Py of the polarizer 101 is less than 95%, it may not function as an antireflection film.
  • the luminosity-corrected polarization degree Py can be measured by the method described below.
  • Increasing the luminosity-corrected polarization degree Py of the polarizer is advantageous in terms of improving the function of the optical laminate as an anti-reflection film and the durability of the optical laminate. If the luminosity-corrected polarization degree Py of the polarizer is less than 95%, it may not function as an anti-reflection film.
  • the thickness of the polarizer is 15 ⁇ m or less, preferably 13 ⁇ m or less, and more preferably 10 ⁇ m or less. If the thickness of the polarizer is within this range, it is advantageous for making the optical laminate thinner, and the amount of change in phase difference can be more effectively suppressed.
  • the thickness of the polarizer is usually 2 ⁇ m or more, preferably 3 ⁇ m or more, and may be, for example, 5 ⁇ m or more.
  • the luminosity-corrected single transmittance Ty of the polarizer 101 is typically 40% or more, preferably 41% or more, and more preferably 42% or more.
  • the luminosity-corrected single transmittance Ty of the polarizer 101 is typically 50% or less, and may be 48% or less, 46% or less, 44% or less, or 43% or less. If the luminosity-corrected single transmittance Ty is excessively high, the luminosity-corrected polarization degree Py may become too low, and the circular polarizer may not be able to function as an anti-reflection film.
  • the luminosity-corrected single transmittance Ty can be measured by the method described below.
  • the retardation plate 20 includes a layer that exhibits retardation.
  • the layer that exhibits retardation may be a retardation film formed by stretching a thermoplastic resin film or the like, or may be an optically anisotropic layer (hereinafter also referred to as a "retardation film") made of an oriented polymer of a polymerizable liquid crystal compound.
  • the thickness of the retardation plate 20 is, for example, 1 ⁇ m or more and 10 ⁇ m or less.
  • the upper limit of the above range is preferably 8 ⁇ m, and more preferably 6 ⁇ m.
  • (3-1) Retardation Film A composition containing a polymerizable liquid crystal compound (hereinafter also referred to as a "composition for forming a retardation film") is applied onto a transparent substrate to form an optically anisotropic layer made of an aligned polymer of the polymerizable liquid crystal compound, which is preferable in terms of enabling a thin film to be formed and allowing arbitrary design of wavelength dispersion characteristics.
  • the composition for forming a retardation film may further include a solvent, a photopolymerization initiator, a photosensitizer, a polymerization inhibitor, a leveling agent, an adhesion improver, and the like.
  • the retardation film is usually formed by applying a retardation film-forming composition onto an alignment film formed on a substrate, and polymerizing the polymerizable liquid crystal compound contained in the retardation film-forming composition.
  • the retardation film is usually a film in which the polymerizable liquid crystal compound is cured in an oriented state, and in order to generate a retardation in the viewing plane, the film must be a cured film in which the polymerizable group is polymerized while the polymerizable liquid crystal compound is oriented horizontally relative to the substrate surface.
  • the polymerizable liquid crystal compound is a rod-shaped liquid crystal, a positive A plate is sufficient
  • the polymerizable liquid crystal compound is a disc-shaped liquid crystal, a negative A plate is sufficient.
  • the retardation film may contain two or more layers of different optical anisotropy. To achieve high anti-reflection function, it is sufficient to have a ⁇ /4 plate function (i.e., a ⁇ /2 phase difference function) in the entire visible light range. Specifically, a reverse wavelength dispersion ⁇ /4 layer is preferable, or it is preferable to combine two or more types of retardation films with different orientations. For example, it may be a combination of a retardation film having a ⁇ /2 plate function (i.e., a ⁇ phase difference function) and a retardation film having a ⁇ /4 plate function (i.e., a ⁇ /2 phase difference function).
  • each optical anisotropy layer may have a tilt orientation or may form a cholesteric orientation state.
  • the retardation plate 20 When the retardation plate 20 is formed by bonding two or more retardation films having different orientations, they can be bonded via a third bonding layer 30c.
  • the ⁇ /4 function over the entire visible light range preferably satisfies the optical characteristics shown in the following formula (1), where Re( ⁇ ) is an in-plane retardation value for light with a wavelength of ⁇ nm, and more preferably satisfies the optical characteristics shown in the following formulas (1), (2), and (3).
  • Re(550) represents an in-plane phase difference value (in-plane retardation) for light having a wavelength of 550 nm.
  • Re(450)/Re(550) ⁇ 1.0 (2) 1.00 ⁇ Re(650)/Re(550) (3)
  • Re(450) represents an in-plane retardation value for light having a wavelength of 450 nm
  • Re(550) represents an in-plane retardation value for light having a wavelength of 550 nm
  • Re(650) represents an in-plane retardation value for light having a wavelength of 650 nm.
  • the value of "Re(450)/Re(550)” is preferably 0.7 or more and 1.0 or less, more preferably 0.80 or more and 0.95 or less, even more preferably 0.80 or more and 0.92 or less, and particularly preferably 0.82 or more and 0.88 or less.
  • the value of "Re(450)/Re(550)” can be arbitrarily adjusted by adjusting the mixing ratio of the polymerizable liquid crystal compound, the lamination angle of the multiple retardation films, and the retardation value.
  • the in-plane retardation value of the retardation film can be adjusted by the thickness of the retardation film. Since the in-plane retardation value is determined by the following formula (4), the desired in-plane retardation value (Re( ⁇ )) can be obtained by adjusting ⁇ n( ⁇ ) and the thickness d.
  • the thickness of the retardation film is preferably 0.5 ⁇ m to 5 ⁇ m, and more preferably 1 ⁇ m to 3 ⁇ m.
  • the thickness of the retardation film can be measured by an interference film thickness meter, a laser microscope, or a stylus film thickness meter. ⁇ n( ⁇ ) depends on the molecular structure of the polymerizable liquid crystal compound described later.
  • Re( ⁇ ) d ⁇ n( ⁇ ) (4)
  • Re( ⁇ ) represents an in-plane retardation value at a wavelength of ⁇ nm
  • d represents a thickness
  • ⁇ n( ⁇ ) represents a birefringence at a wavelength of ⁇ nm.
  • the positive C plate is not particularly limited as long as it has anisotropy in the thickness direction, but if it does not have tilt alignment or cholesteric alignment, it has the optical characteristic expressed by formula (5).
  • the in-plane retardation value Re(550) of the positive C plate at a wavelength of 550 nm is usually in the range of 0 to 10 nm, preferably in the range of 0 to 5 nm.
  • the retardation value Rth(550) in the thickness direction at a wavelength of 550 nm is usually in the range of -170 nm or more and -10 nm or less, preferably in the range of -150 nm or more and -20 nm or less, more preferably in the range of -100 nm or more and -40 nm or less. If the retardation value in the thickness direction is in this range, the anti-reflection properties from oblique directions can be further improved.
  • the polymerizable liquid crystal compound contained in the retardation film forming composition means a liquid crystal compound having a polymerizable group, particularly a photopolymerizable group, and as the polymerizable liquid crystal compound, a conventionally known polymerizable liquid crystal compound can be used.
  • the photopolymerizable group refers to a group that can be involved in a polymerization reaction by a reactive species generated from a photopolymerization initiator, such as an active radical or an acid.
  • Examples of the photopolymerizable group include vinyl groups, vinyloxy groups, 1-chlorovinyl groups, isopropenyl groups, 4-vinylphenyl groups, acryloyloxy groups, methacryloyloxy groups, oxiranyl groups, and oxetanyl groups. Among them, acryloyloxy groups, methacryloyloxy groups, vinyloxy groups, oxiranyl groups, and oxetanyl groups are preferred, and acryloyloxy groups are more preferred.
  • the liquid crystal property may be thermotropic or lyotropic, but thermotropic liquid crystals are preferred because of the ability to precisely control the film thickness.
  • the phase order structure in the thermotropic liquid crystal may be nematic or smectic liquid crystal.
  • the polymerizable liquid crystal compounds may be rod-shaped or discotic. They may be used alone or in combination of two or more.
  • liquid crystals having a T-shaped or H-shaped mesogenic structure that also has birefringence in the direction perpendicular to the molecular long axis direction are preferred, and from the viewpoint of obtaining stronger dispersion, T-shaped liquid crystals are more preferred, and specific examples of the T-shaped liquid crystal structure include compounds represented by the following formula (I):
  • Ar represents a divalent aromatic group which may have a substituent.
  • the divalent aromatic group preferably contains at least one of a nitrogen atom, an oxygen atom, and a sulfur atom.
  • the divalent group Ar contains two or more aromatic groups, the two or more aromatic groups may be bonded to each other via a divalent bonding group such as a single bond, -CO-O-, or -O-.
  • G 1 and G 2 each independently represent a divalent aromatic group or a divalent alicyclic hydrocarbon group.
  • a hydrogen atom contained in the divalent aromatic group or divalent alicyclic hydrocarbon group may be substituted with a halogen atom, an alkyl group having 1 to 4 carbon atoms, a fluoroalkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, a cyano group, or a nitro group, and a carbon atom constituting the divalent aromatic group or the divalent alicyclic hydrocarbon group may be substituted with an oxygen atom, a sulfur atom, or a nitrogen atom.
  • L 1 , L 2 , B 1 and B 2 each independently represent a single bond or a divalent linking group.
  • k and l each independently represent an integer of 0 to 3, and satisfy the relationship 1 ⁇ k+l, where, when 2 ⁇ k+l, B 1 and B 2 , and G 1 and G 2 may be the same or different from each other.
  • E1 and E2 each independently represent an alkanediyl group having 1 to 17 carbon atoms, in which a hydrogen atom contained in the alkanediyl group may be substituted with a halogen atom, and -CH2- contained in the alkanediyl group may be substituted with -O-, -S- or -COO-, and when there are a plurality of -O-, -S- or -COO-, they are not adjacent to each other.
  • P1 and P2 each independently represent a polymerizable group or a hydrogen atom, and at least one of them is a polymerizable group.
  • G 1 and G 2 are each independently preferably a 1,4-phenylenediyl group which may be substituted with at least one substituent selected from the group consisting of a halogen atom and an alkyl group having 1 to 4 carbon atoms, or a 1,4-cyclohexanediyl group which may be substituted with at least one substituent selected from the group consisting of a halogen atom and an alkyl group having 1 to 4 carbon atoms, more preferably a 1,4-phenylenediyl group substituted with a methyl group, an unsubstituted 1,4-phenylenediyl group, or an unsubstituted 1,4-trans-cyclohexanediyl group, particularly preferably an unsubstituted 1,4-phenylenediyl group or an unsubstituted 1,4-trans-cyclohexanediyl group.
  • At least one of the multiple G 1s and G 2s is a divalent alicyclic hydrocarbon group, and it is even more preferred that at least one of the G 1s and G 2s bonded to L 1 or L 2 is a divalent alicyclic hydrocarbon group.
  • L 1 and L 2 are each independently preferably a single bond, an alkylene group having 1 to 4 carbon atoms, -O-, -S-, -R a1 OR a2 -, -R a3 COOR a4 -, -R a5 OCOR a6 -, R a7 OC ⁇ OOR a8 -, -N ⁇ N-, -CR c ⁇ CR d -, or -C ⁇ C-, where R a1 to R a8 are each independently a single bond or an alkylene group having 1 to 4 carbon atoms, and R c and R d are an alkyl group having 1 to 4 carbon atoms or a hydrogen atom.
  • L 1 and L 2 are each independently more preferably a single bond, -OR a2-1 -, -CH 2 -, -CH 2 CH 2 -, -COOR a4-1 -, or OCOR a6-1 -.
  • R a2-1 , R a4-1 , and R a6-1 each independently represent a single bond, -CH 2 -, or -CH 2 CH 2 -.
  • L 1 and L 2 are each independently more preferably a single bond, -O-, -CH 2 CH 2 -, -COO-, -COOCH 2 CH 2 -, or OCO-.
  • B 1 and B 2 are each independently preferably a single bond, an alkylene group having 1 to 4 carbon atoms, -O-, -S-, -R a9 OR a10 -, -R a11 COOR a12 -, -R a13 OCOR a14 -, or R a15 OC ⁇ OOR a16 -.
  • R a9 to R a16 are each independently a single bond, or an alkylene group having 1 to 4 carbon atoms.
  • B 1 and B 2 are each independently more preferably a single bond, -OR a10-1 -, -CH 2 -, -CH 2 CH 2 -, -COOR a12-1 -, or OCOR a14-1 -.
  • R a10-1 , R a12-1 and R a14-1 each independently represent a single bond, -CH 2 - or -CH 2 CH 2 -.
  • B 1 and B 2 each independently represent more preferably a single bond, -O-, -CH 2 CH 2 -, -COO-, -COOCH 2 CH 2 -, -OCO- or OCOCH 2 CH 2 -.
  • E 1 and E 2 each independently preferably represent an alkanediyl group having 1 to 17 carbon atoms, and more preferably an alkanediyl group having 4 to 12 carbon atoms.
  • Examples of the polymerizable group represented by P1 or P2 include an epoxy group, a vinyl group, a vinyloxy group, a 1-chlorovinyl group, an isopropenyl group, a 4-vinylphenyl group, an acryloyloxy group, a methacryloyloxy group, an oxiranyl group, and an oxetanyl group.
  • an acryloyloxy group a methacryloyloxy group, a vinyloxy group, an oxiranyl group, and an oxetanyl group are preferred, and an acryloyloxy group is more preferred.
  • Ar preferably has at least one selected from an aromatic hydrocarbon ring which may have a substituent, an aromatic heterocycle which may have a substituent, and an electron-withdrawing group.
  • aromatic hydrocarbon ring examples include a benzene ring, a naphthalene ring, and an anthracene ring, and a benzene ring and a naphthalene ring are preferred.
  • Examples of the aromatic heterocycle include a furan ring, a benzofuran ring, a pyrrole ring, an indole ring, a thiophene ring, a benzothiophene ring, a pyridine ring, a pyrazine ring, a pyrimidine ring, a triazole ring, a triazine ring, a pyrroline ring, an imidazole ring, a pyrazole ring, a thiazole ring, a benzothiazole ring, a thienothiazole ring, an oxazole ring, a benzoxazole ring, and a phenanthroline ring.
  • Ar has a thiazole ring, a benzothiazole ring, or a benzofuran ring, and it is even more preferred that Ar has a benzothiazole group.
  • Ar when Ar contains a nitrogen atom, it is preferred that the nitrogen atom has ⁇ electrons.
  • the total number N ⁇ of ⁇ electrons contained in the divalent aromatic group represented by Ar is preferably 8 or more, more preferably 10 or more, even more preferably 14 or more, and particularly preferably 16 or more. Also, it is preferably 30 or less, more preferably 26 or less, and even more preferably 24 or less.
  • the aromatic group represented by Ar is preferably, for example, the following group:
  • the mark * represents a linking portion
  • Z 0 , Z 1 and Z 2 each independently represent a hydrogen atom, a halogen atom, an alkyl group having 1 to 12 carbon atoms, a cyano group, a nitro group, an alkylsulfinyl group having 1 to 12 carbon atoms, an alkylsulfonyl group having 1 to 12 carbon atoms, a carboxyl group, a fluoroalkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, an alkylthio group having 1 to 12 carbon atoms, an N-alkylamino group having 1 to 12 carbon atoms, an N,N-dialkylamino group having 2 to 12 carbon atoms, an N-alkylsulfamoyl group having 1 to 12 carbon atoms, or an N,N-dialkylsulfamoyl group having 2 to
  • Q 1 , Q 2 and Q 3 each independently represent -CR 2' R 3' -, -S-, -NH-, -NR 2' -, -CO- or O-, and R 2' and R 3' each independently represent a hydrogen atom or an alkyl group having 1 to 4 carbon atoms.
  • J 1 and J 2 each independently represent a carbon atom or a nitrogen atom.
  • Y 1 , Y 2 and Y 3 each independently represent an aromatic hydrocarbon group or an aromatic heterocyclic group which may be substituted.
  • W 1 and W 2 each independently represent a hydrogen atom, a cyano group, a methyl group, or a halogen atom; m represents an integer of 0 to 6.
  • the aromatic hydrocarbon group in Y 1 , Y 2 and Y 3 include aromatic hydrocarbon groups having 6 to 20 carbon atoms, such as a phenyl group, a naphthyl group, an anthryl group, a phenanthryl group and a biphenyl group, of which a phenyl group and a naphthyl group are preferred, and a phenyl group is more preferred.
  • aromatic heterocyclic group examples include aromatic heterocyclic groups having 4 to 20 carbon atoms and containing at least one heteroatom, such as a nitrogen atom, an oxygen atom or a sulfur atom, such as a furyl group, a pyrrolyl group, a thienyl group, a pyridinyl group, a thiazolyl group and a benzothiazolyl group, of which a furyl group, a thienyl group, a pyridinyl group, a thiazolyl group and a benzothiazolyl group are preferred.
  • Y1 , Y2 and Y3 may each independently be an optionally substituted polycyclic aromatic hydrocarbon group or polycyclic aromatic heterocyclic group.
  • the polycyclic aromatic hydrocarbon group refers to a condensed polycyclic aromatic hydrocarbon group or a group derived from an aromatic ring assembly.
  • the polycyclic aromatic heterocyclic group refers to a condensed polycyclic aromatic heterocyclic group or a group derived from an aromatic ring assembly.
  • Z 0 , Z 1 and Z 2 are each preferably independently a hydrogen atom, a halogen atom, an alkyl group having 1 to 12 carbon atoms, a cyano group, a nitro group, or an alkoxy group having 1 to 12 carbon atoms
  • Z 0 is more preferably a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, or a cyano group
  • Z 1 and Z 2 are more preferably a hydrogen atom, a fluorine atom, a chlorine atom, a methyl group, or a cyano group.
  • Q 1 , Q 2 and Q 3 are preferably -NH-, -S-, -NR 2' - or -O-, and R 2' is preferably a hydrogen atom.
  • R 2' is preferably a hydrogen atom.
  • -S-, -O- and -NH- are particularly preferred.
  • the formulae (Ar-1) to (Ar-23) the formulae (Ar-6) and (Ar-7) are preferred from the viewpoint of molecular stability.
  • Y 1 may form an aromatic heterocyclic group together with the nitrogen atom to which it is bonded and Z 0.
  • the aromatic heterocyclic group include those described above as aromatic heterocyclic rings that Ar may have, such as a pyrrole ring, an imidazole ring, a pyrroline ring, a pyridine ring, a pyrazine ring, a pyrimidine ring, an indole ring, a quinoline ring, an isoquinoline ring, a purine ring, and a pyrrolidine ring.
  • This aromatic heterocyclic group may have a substituent.
  • Y 1 may be, together with the nitrogen atom to which it is bonded and Z 0 , the aforementioned polycyclic aromatic hydrocarbon group or polycyclic aromatic heterocyclic group which may be substituted.
  • examples include a benzofuran ring, a benzothiazole ring, and a benzoxazole ring.
  • the maximum absorption wavelength of the polymerizable liquid crystal compound can be measured using a UV-visible spectrophotometer in a solvent.
  • the solvent is a solvent that can dissolve the polymerizable liquid crystal compound, such as chloroform.
  • R 40 represents the following formulae (W-1) to (W-5).]
  • X 40 and Z 40 each independently represent an alkanediyl group having 1 to 12 carbon atoms, and a hydrogen atom contained in the alkanediyl group may be substituted with an alkoxy group having 1 to 5 carbon atoms, and a hydrogen atom contained in the alkoxy group may be substituted with a halogen atom.
  • -CH 2 - constituting the alkanediyl group may be replaced with -O- or -CO-.
  • m2 represents an integer.
  • Examples of the rod-shaped polymerizable liquid crystal compound include compounds represented by formula (II), formula (III), formula (IV), formula (V), formula (VI) or formula (VII).
  • A11-B11-E11-B12-A11-B13-A12-B14-A13-B15-A14-B16-E12-B17-P12 (II) P11-B11-E11-B12-A11-B13-A12-B14-A13-B15-A14-F11 (III) P11-B11-E11-B12-A11-B13-A12-B14-A13-B15-E12-B17-P12 (IV) P11-B11-E11-B12-A11-B13-A12-B14-A13-F11 (V) P11-B11-E11-B12-A11-B13-A12-B14-E12-B17-P12 (VI) P11-B11-E11-B12-A11-B13-A12-F11 (VII) [In formulas (II) to (VII), A11 to A14 each independently represent a divalent alicyclic hydrocarbon group or
  • a hydrogen atom contained in the divalent alicyclic hydrocarbon group and the divalent aromatic hydrocarbon group may be substituted with a halogen atom, an alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, a cyano group, or a nitro group, and a hydrogen atom contained in the alkyl group having 1 to 6 carbon atoms and the alkoxy group having 1 to 6 carbon atoms may be substituted with a fluorine atom.
  • B11 and B17 each independently represent -O-, -S-, -CO-O-, -O-CO-, -O-CO-O-, -CO-NR 16 -, -NR 16 -CO-, -CO-, -CS-, or a single bond
  • R 16 represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms.
  • E11 and E12 each independently represent an alkanediyl group having 1 to 12 carbon atoms, a hydrogen atom contained in the alkanediyl group may be substituted with an alkoxy group having 1 to 5 carbon atoms, and a hydrogen atom contained in the alkoxy group may be substituted with a halogen atom. Furthermore, --CH 2 -- constituting the alkanediyl group may be replaced by --O-- or --CO--.
  • F11 represents a hydrogen atom, an alkyl group having 1 to 13 carbon atoms, an alkoxy group having 1 to 13 carbon atoms, a cyano group, a nitro group, a trifluoromethyl group, a dimethylamino group, a hydroxy group, a methylol group, a formyl group, a sulfo group (—SO 3 H), a carboxy group, an alkoxycarbonyl group having 1 to 10 carbon atoms, or a halogen atom, and —CH 2 — constituting the alkyl group and the alkoxy group may be replaced by —O—.
  • P11 and P12 each independently represent a polymerizable group.
  • the content of the polymerizable liquid crystal compound in the retardation film-forming composition is, for example, 70 to 99.5 parts by mass, preferably 80 to 99 parts by mass, more preferably 85 to 98 parts by mass, and even more preferably 90 to 95 parts by mass, based on 100 parts by mass of the solid content of the retardation film-forming composition. If the content of the polymerizable liquid crystal compound is within the above range, it is advantageous from the viewpoint of the alignment of the obtained retardation film.
  • the solid content of the polymerizable liquid crystal composition means all components excluding volatile components such as organic solvents from the polymerizable liquid crystal composition.
  • the retardation film forming composition contains a polymerizable liquid crystal compound.
  • the retardation film forming composition may further contain reactive additives such as a solvent, a leveling agent, a polymerization initiator, a photosensitizer, a polymerization inhibitor, a crosslinking agent, and an adhesion agent, and it is preferable that the composition contains a solvent and a leveling agent from the viewpoint of processability.
  • the composition for forming the retardation film may contain a solvent. Since polymerizable liquid crystal compounds generally have high viscosity, dissolving the composition for forming the retardation film in a solvent often makes it easier to apply, and as a result, makes it easier to form the retardation film.
  • the solvent is preferably one that can completely dissolve the polymerizable liquid crystal compound, and is preferably a solvent that is inactive to the polymerization reaction of the polymerizable liquid crystal compound.
  • Solvents include alcohol solvents such as methanol, ethanol, ethylene glycol, isopropyl alcohol, propylene glycol, ethylene glycol methyl ether, ethylene glycol butyl ether, and propylene glycol monomethyl ether; ester solvents such as ethyl acetate, butyl acetate, ethylene glycol methyl ether acetate, ⁇ -butyrolactone or propylene glycol methyl ether acetate, and ethyl lactate; ketone solvents such as acetone, methyl ethyl ketone, cyclopentanone, cyclohexanone, 2-heptanone, and methyl isobutyl ketone; aliphatic hydrocarbon solvents such as pentane, hexane, and heptane; aromatic hydrocarbon solvents such as toluene and xylene, and nitrile solvents such as acetonitrile; ether solvents such as t
  • the composition for forming the retardation film may contain a leveling agent.
  • a leveling agent is an additive that adjusts the fluidity of the composition and functions to make the film obtained by applying the composition flatter.
  • leveling agents include organically modified silicone-based, polyacrylate-based, and perfluoroalkyl-based leveling agents. Among them, polyacrylate-based and perfluoroalkyl-based leveling agents are preferred for horizontal alignment, and organically modified silicone-based and perfluoroalkyl-based leveling agents are preferred for vertical alignment.
  • the photopolymerization initiator may be any known photopolymerization initiator, so long as it is a compound capable of initiating the polymerization reaction of the polymerizable liquid crystal compound. Specific examples include photopolymerization initiators capable of generating active radicals or acids under the action of light, and among these, photopolymerization initiators that generate radicals under the action of light are preferred. Photopolymerization initiators may be used alone or in combination of two or more types.
  • the composition for forming the retardation film may contain an antioxidant.
  • the antioxidant can control the degree of progress of the polymerization reaction of the polymerizable liquid crystal compound.
  • the film surface may be irradiated directly with polarized light, or the substrate side may be irradiated with polarized light and the polarized light may be transmitted through the film. It is particularly preferable that the polarized light is substantially parallel light.
  • the wavelength of the polarized light to be irradiated is preferably in a wavelength range in which the photoreactive group of the polymer or monomer having a photoreactive group can absorb light energy. Specifically, UV (ultraviolet light) with a wavelength of 250 to 400 nm is particularly preferable.
  • Examples of light sources used for the polarized light irradiation include xenon lamps, high-pressure mercury lamps, ultra-high-pressure mercury lamps, metal halide lamps, and ultraviolet lasers such as KrF and ArF, and high-pressure mercury lamps, ultra-high-pressure mercury lamps, and metal halide lamps are more preferable. These lamps are preferable because they have a high emission intensity of ultraviolet light with a wavelength of 313 nm.
  • Polarized light can be irradiated by passing the light from the light source through an appropriate polarizer.
  • a polarizing filter, a polarizing prism such as Glan-Thompson or Glan-Taylor, or a wire grid type polarizer can be used.
  • the first bonding layer 30a may have selective light absorption properties. That is, the first bonding layer 30a may contain a light absorbing agent.
  • the light absorbing agent is preferably an ultraviolet absorbing agent.
  • (4-2) Second Attachment Layer The second attachment layer 30b is a pressure-sensitive adhesive layer or an adhesive layer, and is preferably a pressure-sensitive adhesive layer. The second attachment layer 30b bonds the optical laminate 1 to, for example, an image display element 40 or the like.
  • the thickness of the second bonding layer 30b is, for example, 5 ⁇ m or more and 30 ⁇ m or less.
  • the upper limit of the above range is preferably 25 ⁇ m, and more preferably 20 ⁇ m.
  • the lower limit of the above range is preferably 10 ⁇ m.
  • the second bonding layer 30b may have selective light absorption properties. That is, the second bonding layer 30b may contain a light absorbing agent.
  • the light absorbing agent is preferably an ultraviolet absorbing agent.
  • (4-3) Third bonding layer The third bonding layer 30c is a pressure-sensitive adhesive layer or an adhesive layer, and is preferably an adhesive layer. More preferably, it is an adhesive layer obtained by curing an active energy ray curable adhesive, and even more preferably, it is an adhesive layer obtained by curing an ultraviolet ray curable adhesive.
  • the third bonding layer 30c is an adhesive layer, it is possible to suppress the occurrence of wrinkles in the liquid crystal cured layer when the circular polarizer is folded or folded.
  • the third bonding layer 30c bonds the first liquid crystal cured layer 201 and the second liquid crystal cured layer 202.
  • the thickness of the third bonding layer 30c is 0.5 ⁇ m or more, the adhesion to the first liquid crystal cured layer 201 and the second liquid crystal cured layer 202 can be improved. If the thickness of the third bonding layer 30c is 4.5 ⁇ m or less, it becomes easier to suppress the bulging of the end of the polarizer 101.
  • Acrylamide monomers include N-(methoxymethyl)acrylamide, N-(ethoxymethyl)acrylamide, N-(propoxymethyl)acrylamide, N-(butoxymethyl)acrylamide, and N-(2-methylpropoxymethyl)acrylamide.
  • the weight average molecular weight (hereinafter also simply referred to as "Mw") of the (meth)acrylic resin (1) is preferably 500,000 to 2,500,000. If the weight average molecular weight is 500,000 or more, the durability of the first adhesive layer in a high temperature and high humidity environment can be improved. If the weight average molecular weight is 2,500,000 or less, the operability when applying a coating liquid containing the adhesive composition is improved.
  • the molecular weight distribution (Mw/Mn) which is expressed as the ratio of the weight average molecular weight (Mw) to the number average molecular weight (hereinafter also simply referred to as "Mn”), is usually 2 to 10.
  • the "weight average molecular weight” and the "number average molecular weight” are polystyrene equivalent values measured by gel permeation chromatography (GPC).
  • the viscosity at 25°C is preferably 20 Pa ⁇ s or less, and more preferably 0.1 to 15 Pa ⁇ s. If the viscosity of the (meth)acrylic resin at 25°C is within the above range, it contributes to improved durability and reworkability of a polarizing plate including an adhesive layer formed from the resin.
  • the viscosity can be measured using a Brookfield viscometer.
  • the glass transition temperature (Tg) of the (meth)acrylic resin is, for example, -60 to 20°C, preferably -50 to 15°C, more preferably -45 to 10°C, and even more preferably -40 to 0°C.
  • the glass transition temperature can be measured by a differential scanning calorimeter (DSC).
  • the (meth)acrylic resin may contain two or more types of (meth)acrylic acid ester polymers.
  • Examples of such (meth)acrylic acid ester polymers include those that are mainly composed of structural units (Ia) derived from the (meth)acrylic acid ester and have a relatively low molecular weight, such as a (meth)acrylic acid ester polymer with a weight average molecular weight in the range of 50,000 to 300,000.
  • (Meth)acrylic resins can usually be produced by known polymerization methods such as solution polymerization, bulk polymerization, suspension polymerization, and emulsion polymerization. In producing (meth)acrylic resins, polymerization is usually carried out in the presence of a polymerization initiator. The amount of polymerization initiator used is usually 0.001 to 5 parts by mass per 100 parts by mass of the total of all monomers constituting the (meth)acrylic resin. (Meth)acrylic resins can also be produced by a method of polymerization using active energy rays such as ultraviolet rays.
  • the pressure-sensitive adhesive composition preferably contains a crosslinking agent.
  • the crosslinking agent include conventional crosslinking agents (e.g., isocyanate compounds, epoxy compounds, aziridine compounds, metal chelate compounds, peroxides, etc.), and in particular, from the viewpoints of the pot life of the pressure-sensitive adhesive composition, crosslinking speed, and durability of the polarizing plate, it is preferable to use an isocyanate compound.
  • the proportion of the crosslinking agent is, for example, 0.01 to 10 parts by mass, preferably 0.05 to 5 parts by mass, and more preferably 0.1 to 1 part by mass, per 100 parts by mass of the (meth)acrylic resin.
  • the silane compound may also contain an oligomer derived from the above silane compound.
  • the content of the silane compound in the pressure-sensitive adhesive composition is usually 0.01 to 10 parts by mass, and preferably 0.05 to 5 parts by mass, relative to 100 parts by mass of the (meth)acrylic resin.
  • the content of the silane compound is 0.01 part by mass or more, the adhesion between the pressure-sensitive adhesive layer and the adherend tends to be improved, and when the content is 10 parts by mass or less, bleeding out of the silane compound from the pressure-sensitive adhesive layer tends to be suppressed.
  • the pressure-sensitive adhesive composition may further include an antistatic agent.
  • the antistatic agent include known ones, and ionic antistatic agents are preferred.
  • the cationic component constituting the ionic antistatic agent include organic cations and inorganic cations.
  • the organic cation include pyridinium cation, imidazolium cation, ammonium cation, sulfonium cation, phosphonium cation, etc.
  • the inorganic cation include alkali metal cations such as lithium cation, potassium cation, sodium cation, and cesium cation, and alkaline earth metal cations such as magnesium cation and calcium cation.
  • an ionic antistatic agent that is solid at room temperature is preferred.
  • the content of the antistatic agent is, for example, 0.01 to 20 parts by mass, preferably 0.1 to 10 parts by mass, and more preferably 1 to 7 parts by mass, relative to 100 parts by mass of the (meth)acrylic resin.
  • the adhesive composition may contain one or more additives such as ultraviolet absorbers, solvents, crosslinking catalysts, tackifiers, and plasticizers. It is also useful to incorporate an ultraviolet-curable compound into the adhesive composition, form an adhesive layer, and then irradiate the adhesive with ultraviolet light to cure the compound, thereby forming a harder adhesive layer.
  • additives such as ultraviolet absorbers, solvents, crosslinking catalysts, tackifiers, and plasticizers. It is also useful to incorporate an ultraviolet-curable compound into the adhesive composition, form an adhesive layer, and then irradiate the adhesive with ultraviolet light to cure the compound, thereby forming a harder adhesive layer.
  • the adhesive layer can be formed, for example, by dissolving or dispersing the adhesive composition in a solvent to form a solvent-containing adhesive composition, which is then applied to the surface of the layer on which the adhesive layer is to be formed, and then drying.
  • the thickness of the pressure-sensitive adhesive layer is usually 0.1 to 30 ⁇ m, preferably 3 to 30 ⁇ m, and more preferably 5 to 25 ⁇ m.
  • Adhesive Layer The adhesive layer can be formed from an adhesive composition.
  • the adhesive composition examples include aqueous adhesive compositions and curable adhesive compositions that are cured by heating or by irradiation with active energy rays such as ultraviolet rays, visible light, electron beams, and X-rays.
  • active energy rays such as ultraviolet rays, visible light, electron beams, and X-rays.
  • the aqueous adhesive composition include those in which a polyvinyl alcohol resin or a urethane resin is dissolved in water as the main component, and those in which a polyvinyl alcohol resin or a urethane resin is dispersed in water as the main component.
  • the aqueous adhesive composition may further contain a curing component or a crosslinking agent such as a polyhydric aldehyde, a melamine compound, a zirconia compound, a zinc compound, a glyoxal compound, or a water-soluble epoxy resin.
  • a curing component or a crosslinking agent such as a polyhydric aldehyde, a melamine compound, a zirconia compound, a zinc compound, a glyoxal compound, or a water-soluble epoxy resin.
  • the curable adhesive composition is preferably an active energy ray-curable adhesive composition that contains a curable (polymerizable) compound as the main component and is cured by irradiation with active energy rays.
  • active energy ray-curable adhesive compositions include cationic polymerization adhesive compositions that contain a cationic polymerizable compound as the curable compound, radical polymerization adhesive compositions that contain a radical polymerizable compound as the curable compound, and hybrid adhesive compositions that contain both a cationic polymerizable compound and a radical polymerizable compound as the curable compound.
  • Cationically polymerizable compounds are compounds or oligomers that undergo a cationic polymerization reaction and harden when exposed to active energy rays such as ultraviolet light, visible light, electron beams, or X-rays, or when heated.
  • active energy rays such as ultraviolet light, visible light, electron beams, or X-rays, or when heated.
  • Specific examples include epoxy compounds, oxetane compounds, and vinyl compounds.
  • Epoxy compounds include alicyclic epoxy compounds (compounds having one or more epoxy groups bonded to an alicyclic ring in the molecule) such as 3',4'-epoxycyclohexylmethyl 3,4-epoxycyclohexanecarboxylate; aromatic epoxy compounds (compounds having an aromatic ring and an epoxy group in the molecule) such as diglycidyl ether of bisphenol A; and aliphatic epoxy compounds (compounds having at least one oxirane ring bonded to an aliphatic carbon atom in the molecule) such as 2-ethylhexyl glycidyl ether and 1,4-butanediol diglycidyl ether.
  • Oxetane compounds include compounds that have one or more oxetane rings in the molecule, such as 3-ethyl-3- ⁇ [(3-ethyloxetan-3-yl)methoxy]methyl ⁇ oxetane.
  • the cationic polymerization adhesive composition preferably contains a cationic polymerization initiator.
  • the cationic polymerization initiator may be a thermal cationic polymerization initiator or a photo-induced cationic polymerization initiator.
  • Examples of cationic polymerization initiators include aromatic diazonium salts such as benzenediazonium hexafluoroantimonate; aromatic iodonium salts such as diphenyliodonium tetrakis(pentafluorophenyl)borate; aromatic sulfonium salts such as triphenylsulfonium hexafluorophosphate; and iron-arene complexes such as xylene-cyclopentadienyl iron(II) hexafluoroantimonate.
  • the content of the cationic polymerization initiator is usually 0.1 to 10 parts by mass per 100 parts by mass of the cationic polymerizable compound. Two or more types of
  • cationic polymerization adhesive compositions include the cationic polymerization compositions described in JP 2016-126345 A, WO 2019/10315 A, and JP 2021-113969 A.
  • Radically polymerizable compounds are compounds or oligomers that undergo a radical polymerization reaction and harden when exposed to active energy rays such as ultraviolet light, visible light, electron beams, or X-rays, or when heated.
  • active energy rays such as ultraviolet light, visible light, electron beams, or X-rays
  • Specific examples of compounds that have ethylenically unsaturated bonds include (meth)acrylic compounds that have one or more (meth)acryloyl groups in the molecule, and vinyl compounds that have one or more vinyl groups in the molecule.
  • the light source used to polymerize and cure the active energy ray-curable adhesive composition is not particularly limited, but examples include low pressure mercury lamps, medium pressure mercury lamps, high pressure mercury lamps, ultra-high pressure mercury lamps, xenon lamps, halogen lamps, chemical lamps, black light lamps, microwave excited mercury lamps, and metal halide lamps.
  • the surface protection film may contain an antistatic agent.
  • the antistatic agent may be contained in the adhesive layer, for example.
  • an antistatic layer containing an antistatic agent may be provided on the surface of the resin film for surface protection film opposite to the surface on which the adhesive layer is laminated.
  • the antistatic agent may be an ionic compound, which is a compound having an inorganic or organic cation and an inorganic or organic anion. Two or more ionic compounds may be used.
  • the thickness of this adhesive layer is preferably 5 ⁇ m or more, more preferably 10 ⁇ m or more, and even more preferably 15 ⁇ m or more, and is preferably 30 ⁇ m or less, more preferably 25 ⁇ m or less, and even more preferably 20 ⁇ m or less.
  • the resin constituting the resin film for surface protection film may be, for example, a polyolefin resin such as a polyethylene resin or a polypropylene resin; a cyclic polyolefin resin; a polyester resin such as polyethylene terephthalate or polyethylene naphthalate; a polycarbonate resin; or a (meth)acrylic resin. Of these, a polyester resin such as polyethylene terephthalate is preferred.
  • the resin film for surface protection film may have a single layer structure, or may have a multilayer structure of two or more layers.
  • the resin film for surface protection film may be a film that has been subjected to a stretching process such as uniaxial stretching or biaxial stretching.
  • the image display device can be used as a mobile device such as a smartphone or tablet, a television, a digital photo frame, an electronic signboard, a measuring instrument or gauge, an office device, a medical device, a computing device, etc.
  • a mobile device such as a smartphone or tablet, a television, a digital photo frame, an electronic signboard, a measuring instrument or gauge, an office device, a medical device, a computing device, etc.
  • Excitation wavelength 532 nm Grating: 600 l/mm Slit width: 100 x 1000 ⁇ m Aperture: ⁇ 40 ⁇ m Objective lens: 100x Objective lens: 100x (3) Measurement of moisture permeability of peelable film The moisture permeability was measured based on JIS Z 0208. The temperature and humidity conditions were a temperature of 40° C. and a relative humidity of 90% RH.
  • the evaluation sample was then placed on an aluminum plate (reflector) so that ultraviolet light was irradiated from the polarizer side, and placed in a Sunshine Weather Meter (manufactured by Suga Test Instruments Co., Ltd.) for 240 hours under conditions of a black panel temperature of 63°C and a relative humidity of 50% to conduct a weather resistance test. After the test, the luminosity-corrected polarization degree Py of the evaluation sample was measured. The absolute value ⁇ Py of the difference between the luminosity-corrected polarization degree Py before and after the test was calculated.
  • FIG. 4 shows the evaluation sample.
  • a three-dimensional microscope “PL ⁇ 2300” manufactured by Sensofar was used, and the height of deformation was obtained in a width of 800 ⁇ m from the end face (A) of the short side center of the polarizing plate to the in-plane (A') toward the in-plane center direction in the confocal mode (see FIG. 4).
  • the magnification of the objective lens during the measurement was 20 times.
  • FIG. 5 An example of the result of measuring the height of deformation from the end face (A) of the polarizing plate toward the in-plane (A') is shown in FIG. 5.
  • a negative value of the deformation height means that the optical laminate bonded to the alkali-free glass is deformed toward the alkali-free glass side.
  • a positive value of the deformation height means that the optical laminate bonded to the alkali-free glass is deformed toward the opposite side to the alkali-free glass side.
  • ⁇ (Fair) The height difference of the end deformation is 5 ⁇ m or more and less than 7 ⁇ m.
  • ⁇ (unacceptable) The height difference of the end deformation is 7 ⁇ m or more.
  • (7) Measurement of absorbance of laminate A laminate was produced by laminating the first bonding layer 30a, the first liquid crystal cured layer 201, the third bonding layer 30c, the second liquid crystal cured layer 202, and the second bonding layer 30b. The laminate was bonded to glass via the second bonding layer 30b.
  • a cycloolefin polymer (COP) film ZF-14 manufactured by Zeon Corporation was bonded to the first liquid crystal cured layer 201 via the first bonding layer 30a. In this manner, a laminate for evaluation was produced.
  • COP cycloolefin polymer
  • the polarizer (1) had a thickness of 8 ⁇ m and a boron content of 3.2% by mass.
  • the boric acid crosslinking index was 0.8.
  • Polarizer (2) had a thickness of 8 ⁇ m and a boron content of 4.3% by mass.
  • the boric acid crosslinking index was 1.2.
  • Polarizer (3) was obtained in the same manner as polarizer (2) except that the stretching ratio was changed to 4.1 times, the temperature of boric acid aqueous solution 1 was changed to 64° C., and the temperature of boric acid aqueous solution 2 was changed to 67° C.
  • the polarizer (3) had a thickness of 8 ⁇ m and a boron content of 4.3% by mass.
  • the boric acid crosslinking index was 1.1.
  • peelable film A TD80UL Triacetyl cellulose film manufactured by Fujifilm Corporation. It had a thickness of 80 ⁇ m and a moisture permeability of 502 g/m2 ⁇ 24 hr.
  • Protective film B COP of 23 ⁇ m thickness. It does not have ultraviolet absorption.
  • Surface protective film C An acrylic adhesive layer of 15 ⁇ m thickness was formed on a polyester resin film of 38 ⁇ m thickness to prepare a surface protective film C having an adhesive layer of 53 ⁇ m thickness.
  • the release films A on both sides of the linear polarizing plate (2) were peeled off and removed, and the luminous efficiency-corrected single transmittance measured for the polarizer (2) alone was 42.4%, and the luminous efficiency-corrected polarization degree was 99.98%.
  • a protective film B was attached to one surface of the prepared polarizer (3) via a water-based adhesive, and a peelable film A was attached to the opposite surface of the protective film B via pure water using a roll laminator, and then the resulting film was dried at 80° C. for 3 minutes to obtain a linear polarizing plate (3).
  • the linear polarizing plate (3) was prepared by laminating the peelable film A, the polarizer (3), an adhesive layer, and the protective film B in this order.
  • Polymerizable liquid crystal compound (A1) A compound represented by the following formula:
  • Polymerizable liquid crystal compound (A2) A compound represented by the following formula:
  • Retardation Layer Forming Composition (Y1) A polymerizable liquid crystal compound Paliocolor LC242 (manufactured by BASF Japan), a leveling agent "BYK-361N" (manufactured by BYK-Chemie), and a photopolymerization initiator "Omnirad907" (manufactured by IGM Resin B.V.) were added. Furthermore, propylene glycol 1-monomethyl ether 2-acetate (PGME) was added, and the mixture was stirred at a temperature of 80°C for 1 hour to prepare a retardation layer forming composition (Y1).
  • PGME propylene glycol 1-monomethyl ether 2-acetate
  • Polymerizable liquid crystal compound LC242 Compound represented by the following formula
  • Ionic compound (B) A compound represented by the following formula:
  • the oriented polymer composition (1) was applied to a rectangular cut triacetyl cellulose film (TAC) (Konica Minolta, Inc., KC4UY), and after heating and drying, an oriented polymer film having a thickness of 100 nm was formed.
  • TAC triacetyl cellulose film
  • the surface of the obtained oriented polymer film was subjected to a rubbing treatment at an angle of 15° from the longitudinal direction of the TAC, and the retardation layer forming composition (Y1) was applied thereon by a bar coater.
  • the obtained coating film was dried at 100°C for 1 minute, and then cooled to room temperature to obtain a dried coating.
  • the dried film was irradiated with ultraviolet light at an exposure dose of 1000 mJ/cm 2 (based on 365 nm) under a nitrogen atmosphere using a high-pressure mercury lamp (Ushio Inc.'s "Uniquer VB-15201BY-A”) to form a retardation layer (X1) in which the polymerizable liquid crystal compound was cured in a state of being aligned horizontally relative to the substrate surface, and a retardation film (Z1) consisting of TAC/alignment film/retardation layer (X1) (horizontally aligned liquid crystal cured film) was obtained.
  • the thickness of the obtained retardation layer (X1) was measured with a laser microscope and found to be 1.0 ⁇ m.
  • the orientation angle was 15° with respect to the longitudinal direction of the TAC.
  • COP rectangular cut cycloolefin polymer
  • a corona treatment device A corona treatment device (AGF-B10; manufactured by Kasuga Electric Co., Ltd.), and then an oriented polymer composition (1) was applied thereto, followed by drying by heating to form an oriented polymer film having a thickness of 100 nm.
  • the surface of the obtained oriented polymer film was subjected to rubbing treatment at an angle of 75° from the longitudinal direction of the COP, and a retardation layer forming composition (Y2) was applied thereon using a bar coater.
  • the obtained coating film was dried at 120°C for 2 minutes, and then the dried coating film was irradiated with ultraviolet light at an exposure dose of 1000 mJ/cm 2 (based on 365 nm) at 80°C under a nitrogen atmosphere using a high-pressure mercury lamp ("Uniqure VB-15201BY-A" manufactured by Ushio Inc.), thereby forming a retardation layer (X2) in which the optical axis of the polymerizable liquid crystal compound was aligned horizontally relative to the substrate plane and cured, thereby obtaining a retardation film (Z2) consisting of COP/alignment film/retardation layer (X2).
  • the thickness of the obtained retardation layer (X2) was measured with a laser microscope and found to be 1.8 ⁇ m.
  • the orientation angle was 75° with respect to the longitudinal direction of the COP.
  • Neopentyl glycol diglycidyl ether (product name: EX-211L, manufactured by Nagase ChemteX Corporation) 30 parts by mass 3-ethyl-3 ⁇ [(3-ethyloxetan-3-yl)methoxy]methyl ⁇ oxetane (product name: OXT-221, manufactured by Toagosei Co., Ltd.) 13 parts by mass Bisphenol A type epoxy resin (product name: EP-4100E, manufactured by ADEKA Corporation, viscosity 13 Pa ⁇ s (temperature 25°C)) 45 parts by mass Aromatic-containing oxetane compound (product name: TCM-104, manufactured by TRONLY) 12 parts by mass [Photocationic polymerization initiator] CPI-100P, manufactured by San-Apro Co., Ltd., 50% propylene carbonate solution, 2.25 parts by mass (solid content) [Photosensitizing aid] ⁇ 1,4-diethoxynaphthalene 1 part
  • the corona-treated surfaces of these two retardation layers were bonded together using the active energy ray curable adhesive A prepared above so that the angle between the slow axes of these two retardation layers was 60°. Thereafter, the active energy ray curable adhesive A was cured by irradiating ultraviolet light from the 1/4 wavelength retardation layer side with an ultraviolet irradiation device [manufactured by Fusion UV Systems Co., Ltd.] at an integrated light amount of 400 mJ/cm 2 (UV-B) to form an adhesive layer. The lamination was performed using a laminator, and the active energy ray curable adhesive A was applied so that the thickness of the adhesive layer after curing was 2 ⁇ m.
  • a retardation plate A with a base layer was obtained in which the base layer, the alignment layer, the 1/2 wavelength retardation layer (first liquid crystal cured layer), the adhesive layer (third bonding layer), the 1/4 wavelength retardation layer (second liquid crystal cured layer), the alignment layer, and the base layer were laminated in this order.
  • the total thickness of the 1/2 wavelength retardation layer (first liquid crystal cured layer), the adhesive layer (third bonding layer), and the 1/4 wavelength retardation layer (second liquid crystal cured layer) was 4.8 ⁇ m.
  • Photo-alignable material Compound represented by the following formula
  • Polymerizable liquid crystal compound (A3) and polymerizable liquid crystal compound (A4) having the structures shown below were prepared.
  • Polymerizable liquid crystal compound (A3) was prepared in the same manner as described in JP-A-2019-003177.
  • Polymerizable liquid crystal compound (A4) was prepared in the same manner as described in JP-A-2009-173893.
  • Polymerizable liquid crystal compound (A3) A compound represented by the following formula:
  • Polymerizable liquid crystal compound (A4) Compound represented by the following formula
  • a solution was obtained by dissolving 1 mg of polymerizable liquid crystal compound (A3) in 10 mL of chloroform.
  • the obtained solution was placed in a measurement cell with an optical path length of 1 cm, and the measurement sample was placed in an ultraviolet-visible spectrophotometer (Shimadzu Corporation, UV-2450) to measure the absorption spectrum.
  • the wavelength at which the maximum absorbance was obtained was read from the obtained absorption spectrum, and the maximum absorption wavelength ⁇ max in the wavelength range of 300 to 400 nm was 356 nm.
  • the photo-alignment film-forming composition (X) was applied to a biaxially stretched polyethylene terephthalate (PET) film (Diafoil, manufactured by Mitsubishi Plastics, Inc.) as the substrate C using a bar coater.
  • PET polyethylene terephthalate
  • the resulting coating film was dried at 120°C for 2 minutes and then cooled to room temperature to form a dry film.
  • a UV irradiation device SPDOT CURE SP-9; manufactured by Ushio Inc.
  • the film thickness of the photo-alignment film D measured using an ellipsometer M-220 manufactured by JASCO Corporation was 100 nm.
  • the above-mentioned retardation layer forming composition (Y) was applied onto the obtained photo-aligned film D by a bar coater to form a coating film.
  • This coating film was heated and dried at 120 ° C. for 2 minutes, and then cooled to room temperature to obtain a dried film.
  • a high-pressure mercury lamp ("Uniquer VB-15201BY-A" manufactured by Ushio Electric Co., Ltd.) was used to irradiate the dried film with ultraviolet light at an exposure dose of 500 mJ / cm 2 (based on 365 nm) under a nitrogen atmosphere to form a retardation layer in which the polymerizable liquid crystal compound was aligned horizontally relative to the substrate surface, and a retardation film (Z) consisting of substrate C / photo-aligned film D / retardation layer (horizontally aligned liquid crystal cured film) was obtained.
  • the thickness of the retardation layer measured using a laser microscope LEXT OLS4100 manufactured by Olympus Corporation was 2.0 ⁇ m.
  • the liquid crystal side of the retardation film (Z) was corona-treated, and the film was attached to glass via a 25 ⁇ m pressure-sensitive adhesive manufactured by Lintec Corporation, and the PET film was peeled off and removed.
  • the in-plane retardation values were measured using a KOBRA-WR manufactured by Oji Scientific Instruments Co., Ltd.
  • the in-plane retardation values for light with wavelengths of 450 nm, 550 nm, and 650 nm were calculated using Cauchy's dispersion formula obtained from the measurement results of the in-plane retardation values for light with wavelengths of 448.2 nm, 498.6 nm, 548.4 nm, 587.3 nm, 628.7 nm, and 748.6 nm.
  • Re(450) represents an in-plane retardation value for light having a wavelength of 450 nm
  • Re(550) represents an in-plane retardation value for light having a wavelength of 550 nm
  • Re(650) represents an in-plane retardation value for light having a wavelength of 650 nm.
  • the retardation layer forming composition (1) was prepared by mixing a photopolymerizable nematic liquid crystal compound (RMM28B, manufactured by Merck) and a solvent so that the solid content was 1 to 1.5 g.
  • the solvent used was a mixed solvent of methyl ethyl ketone (MEK), methyl isobutyl ketone (MIBK), and cyclohexanone (CHN) in a mass ratio (MEK:MIBK:CHN) of 35:30:35.
  • a polyethylene terephthalate (PET) film having a thickness of 38 ⁇ m was prepared as a substrate layer.
  • a composition for forming a vertical alignment film was applied to one side of the substrate layer to a thickness of 3 ⁇ m, and the composition was irradiated with ultraviolet light of 200 mJ/cm 2 to prepare a vertical alignment film.
  • the retardation layer forming composition (1) was applied onto the vertical alignment film by die coating.
  • the coating amount was 4 to 5 g (wet).
  • the coating was dried at a drying temperature of 75° C. for 120 seconds. Thereafter, the coating was irradiated with ultraviolet (UV) rays to polymerize the polymerizable liquid crystal compound.
  • UV ultraviolet
  • a retardation film (1) was obtained in which a layer of the cured polymerizable liquid crystal compound (second liquid crystal cured layer B), a vertical alignment film, and a base layer were laminated in this order.
  • the second liquid crystal cured layer B was a positive C plate.
  • the total thickness of the second liquid crystal cured layer B and the alignment film was 4 ⁇ m.
  • the active energy ray curable adhesive B was cured by irradiating ultraviolet rays to obtain a retardation plate B with a substrate layer in which the substrate layer, the alignment layer, the first liquid crystal cured layer B, the adhesive layer (third lamination layer), the second liquid crystal cured layer B, the alignment layer, and the substrate layer were laminated in this order.
  • the thickness of the retardation laminate including the first liquid crystal cured layer B, the adhesive layer (third lamination layer), and the second liquid crystal cured layer B was 7 ⁇ m.
  • the retardation plate B with the substrate layer has ultraviolet absorbing properties.
  • Adhesive layer (1A) (1-1) Preparation of acrylic resin solution (1A) A mixed solution of 100 parts of ethyl acetate, 99.0 parts of butyl acrylate, 0.5 parts of 2-hydroxyethyl acrylate, and 0.5 parts of acrylic acid was charged into a reaction vessel equipped with a cooling tube, a nitrogen inlet tube, a thermometer, and a stirrer, and the air in the apparatus was replaced with nitrogen gas to make it oxygen-free, while raising the internal temperature to 55 ° C.
  • the obtained acrylic resin had a weight average molecular weight Mw of 1.7 million and a molecular weight distribution Mw/Mn of 3.9.
  • Mw and Mn were measured in terms of standard polystyrene using two "TSKgel GMH HR -H(S)" columns manufactured by Tosoh Corporation connected in series as columns in a GPC apparatus, tetrahydrofuran as an eluent, a sample concentration of 2 mg/mL, a sample introduction amount of 100 ⁇ L, a temperature of 40 ° C., and a flow rate of 1 mL/min.
  • A-DOG is a diacrylate of an acetal compound of hydroxypivalaldehyde and trimethylolpropane, and has the following structure:
  • the resulting acrylic resin had a weight average molecular weight (Mw) of 600,000 as calculated based on polystyrene by GPC, and a Mw/Mn of 7.0. This was designated as acrylic resin (A-1).
  • the glass transition temperature (Tg) measured by DSC was ⁇ 52.9° C.
  • the adhesive composition (1) prepared above was applied to the release-treated surface of a release-treated polyethylene terephthalate film (SP-PLR382050 manufactured by Lintec Corporation, hereinafter abbreviated as "separator") using an applicator so that the adhesive layer would have a thickness of 5 ⁇ m after drying, and then dried at 100° C. for 1 minute to prepare an adhesive layer.
  • the resulting adhesive layer was designated adhesive layer (1B) (hereinafter also referred to as light-selective absorbing adhesive 1).
  • adhesive layer (1B) hereinafter also referred to as light-selective absorbing adhesive 1).
  • the content of light-selective absorbing agent per unit area of light-selective absorbing adhesive 1 was 0.2 (g/m 2 ).
  • the light-selective absorbing pressure-sensitive adhesive layer of this example is formed from a pressure-sensitive adhesive composition containing at least a (meth)acrylic resin and a light-selective absorbing compound.
  • the pressure-sensitive adhesive composition preferably further contains a crosslinking agent.
  • the light selective absorption compound is not particularly limited as long as it is a compound that selectively absorbs light with a wavelength of 340 nm.
  • Examples of compounds that selectively absorb light with a wavelength of 340 nm include ultraviolet absorbers.
  • the ultraviolet absorbers are not particularly limited, but examples include organic ultraviolet absorbers such as oxybenzophenone-based ultraviolet absorbers, benzotriazole-based ultraviolet absorbers, salicylic acid ester-based ultraviolet absorbers, benzophenone-based ultraviolet absorbers, cyanoacrylate-based ultraviolet absorbers, and triazine-based ultraviolet absorbers.
  • examples include 5-chloro-2-(3,5-di-sec-butyl-2-hydroxylphenyl)-2H-benzotriazole, (2-2H-benzotriazol-2-yl)-6-(straight-chain and side-chain dodecyl)-4-methylphenol, 2-hydroxy-4-benzyloxybenzophenone, and 2,4-benzyloxybenzophenone.
  • organic ultraviolet absorbers may be used alone or in combination of two or more.
  • the ultraviolet absorber may be a commercially available product.
  • examples of triazine-based ultraviolet absorbers include “Kemisorb 102" manufactured by Chemipro Chemical Co., Ltd., “ADEKA STAB LA46” and “ADEKA STAB LAF70” manufactured by ADEKA Corporation, and "TINUVIN 109", "TINUVIN 171", “TINUVIN 234", “TINUVIN 326", “TINUVIN 327”, “TINUVIN 328", “TINUVIN 928", “TINUVIN 400", “TINUVIN 460", “TINUVIN 405", and “TINUVIN 477” manufactured by BASF Japan Ltd.
  • Benzotriazole-based UV absorbers include "ADEKA STAB LA31” and “ADEKA STAB LA36” manufactured by ADEKA CORPORATION, "Sumisorb 200", “Sumisorb 250", “Sumisorb 300", “Sumisorb 340”, and “Sumisorb 350” manufactured by Sumika Chemtex Co., Ltd., "Kemisorb 74", “Kemisorb 79", and “Kemisorb 279” manufactured by Chemipro Chemical Co., Ltd., and "TINUVIN 99-2", “TINUVIN 900", and “TINUVIN 928” manufactured by BASF.
  • the ultraviolet absorber may also be an inorganic ultraviolet absorber.
  • inorganic ultraviolet absorbers include titanium oxide, zinc oxide, indium oxide, tin oxide, talc, kaolin, calcium carbonate, titanium oxide-based composite oxides, zinc oxide-based composite oxides, ITO (tin-doped indium oxide), ATO (antimony-doped tin oxide), and the like.
  • titanium oxide-based composite oxides include zinc oxide doped with silica and alumina.
  • the weight average molecular weight (Mw) of the (meth)acrylic resin used to form the adhesive layer is the polystyrene equivalent weight average molecular weight measured using gel permeation chromatography (GPC) under the following conditions:
  • GPC measuring device HLC-8020 manufactured by Tosoh Corporation GPC column (passed in the following order): TSK guard column HXL-H manufactured by Tosoh Corporation TSK gel GMHXL (x2) TSK gel G2000HXL, measurement solvent: tetrahydrofuran, measurement temperature: 40°C [Adhesive layer (1C)]
  • An adhesive layer (1C) (hereinafter also referred to as light-selective absorbing adhesive 2) was prepared in the same manner as the adhesive layer (1B), except that the amount of the light-selective absorbing agent was 4.8 parts and the thickness of the adhesive layer after drying was 17 ⁇ m. As shown in Table 4, the content of the light-selective absorbing agent per unit area of the light-selective absorbing adhesive 2 was 0.9 (g/ m2 ).
  • Pressure-sensitive adhesive layer (1B) (hereinafter also referred to as light-selective absorbing pressure-sensitive adhesive 3) was prepared in the same manner as pressure-sensitive adhesive layer (1B), except that the amount of light-selective absorbing agent was 6.3 parts and the thickness of the pressure-sensitive adhesive layer after drying was 17 ⁇ m. As shown in Table 4, the content of light-selective absorbing agent per unit area of light-selective absorbing pressure-sensitive adhesive 3 was 1.2 (g/ m2 ).
  • Adhesive layer (2) (3-1) Preparation of acrylic resin solution (2) A mixed solution of 81.8 parts of ethyl acetate, 90.0 parts of butyl acrylate, 5.0 parts of methyl acrylate and 5.0 parts of acrylic acid was charged into a reaction vessel equipped with a cooling tube, a nitrogen introduction tube, a thermometer and a stirrer, and the air in the apparatus was replaced with nitrogen gas to make it oxygen-free, while raising the internal temperature to 55 ° C. Then, a solution of 0.15 parts of azobisisobutyronitrile (polymerization initiator) dissolved in 10 parts of ethyl acetate was added in its entirety.
  • azobisisobutyronitrile polymerization initiator
  • the resulting acrylic resin had a weight average molecular weight Mw of 1.6 million and a molecular weight distribution Mw/Mn of 4.5.
  • Mw and Mn were measured in terms of standard polystyrene using two "TSKgel GMH HR -H(S)" columns manufactured by Tosoh Corporation connected in series as columns in a GPC apparatus, tetrahydrofuran as an eluent, a sample concentration of 2 mg/mL, a sample introduction amount of 100 ⁇ L, a temperature of 40° C., and a flow rate of 1 mL/min.
  • Example 1 The substrate layer and the alignment layer on the 1/2 wavelength retardation layer side of the retardation plate A with the substrate layer prepared above were peeled off to expose the 1/2 wavelength retardation layer.
  • the bonding of the 1/2 wavelength retardation layer and the linear polarizing plate (1) was performed so that the angle between the slow axis of the 1/2 wavelength retardation layer and the transmission axis of the polarizer (1) was 15°.
  • the peelable film A on the other side was peeled off from the linear polarizing plate (1) to expose the polarizer (1).
  • the exposed polarizer (1) was bonded to the adhesive layer of the surface protective film C.
  • the alignment layer and the base layer on the 1 ⁇ 4 wavelength retardation layer side were peeled off to expose the 1 ⁇ 4 wavelength retardation layer, and the pressure-sensitive adhesive layer (2) was attached to the exposed 1 ⁇ 4 wavelength retardation layer to obtain an optical laminate (1).
  • Each attachment surface was subjected to a corona treatment.
  • Example 2 An optical laminate (2) was obtained in the same manner as in Example 1, except that the linear polarizing plate (1) was replaced with the linear polarizing plate (2).
  • Example 3 An optical laminate (3) was obtained in the same manner as in Example 1, except that the pressure-sensitive adhesive layer (1B) was used as the first attaching layer instead of the pressure-sensitive adhesive layer (1A).
  • Example 4 An optical laminate (4) was obtained in the same manner as in Example 2, except that the pressure-sensitive adhesive layer (1B) was used as the first bonding layer instead of the pressure-sensitive adhesive layer (1A).
  • Example 5 An optical laminate (5) was obtained in the same manner as in Example 1, except that the pressure-sensitive adhesive layer (1C) was used as the first attaching layer instead of the pressure-sensitive adhesive layer (1A).
  • Example 6 An optical laminate (6) was obtained in the same manner as in Example 2, except that the pressure-sensitive adhesive layer (1C) was used as the first bonding layer instead of the pressure-sensitive adhesive layer (1A).
  • Example 7 An optical laminate (7) was obtained in the same manner as in Example 2, except that the pressure-sensitive adhesive layer (1D) was used as the first attaching layer instead of the pressure-sensitive adhesive layer (1A).
  • Example 8 The substrate layer (substrate C) on the first liquid crystal cured layer B side of the substrate layer-attached retardation plate B prepared above was peeled off to expose the alignment layer (photo-alignment film D).
  • the exposed alignment layer (photo-alignment film D) and the polarizer (2) exposed by peeling off the peelable film A of the linear polarizing plate (2) were bonded together using the adhesive layer (1A) which is the first bonding layer.
  • the retardation plate B and the linear polarizing plate (2) were bonded together such that the angle between the slow axis of the first liquid crystal cured layer B and the transmission axis of the polarizer (2) was 45°.
  • the peelable film A on the other side was peeled off from the linear polarizing plate (2) to expose the polarizer (2).
  • the exposed polarizer (2) was bonded to the adhesive layer of the surface protective film C.
  • the substrate layer on the second liquid crystal cured layer B side was peeled off to expose the alignment layer (vertical alignment film), and the pressure-sensitive adhesive layer (2) was bonded to obtain an optical laminate (8).
  • Each bonding surface was subjected to a corona treatment.
  • Comparative Example 1 The substrate layer and the alignment layer on the 1/2 wavelength retardation layer side of the retardation plate A with the substrate layer prepared above were peeled off to expose the 1/2 wavelength retardation layer.
  • the peelable film A of the linear polarizing plate (3) was peeled off to expose the polarizer (3).
  • the exposed polarizer (3) was attached to the adhesive layer of the surface protective film C.
  • the alignment layer and the substrate layer on the 1/4 wavelength retardation layer side were peeled off to expose the 1/4 wavelength retardation layer, and the adhesive layer (2) which is the second attachment layer was attached to the exposed 1/4 wavelength retardation layer to obtain an optical laminate (9). Corona treatment was performed on each attachment surface.
  • the obtained optical laminate was subjected to the above-mentioned weather resistance test after peeling off the surface protective film C together with the pressure-sensitive adhesive layer of the surface protective film C.
  • the results are shown in Table 5.
  • the surface protective film C was peeled off together with the pressure-sensitive adhesive layer of the surface protective film C, and then the above-mentioned edge swelling test was carried out. The results are shown in Table 6.
  • Polarizer 20 Retardation plate
  • 201 First liquid crystal cured layer
  • 30a First bonding layer
  • 30b Second bonding layer
  • 40 Image display element 109: Optical film including pressure-sensitive adhesive layer

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  • Laminated Bodies (AREA)

Abstract

L'invention concerne un stratifié optique, dans lequel les extrémités d'un polariseur sont empêchées de s'accumuler. Un stratifié optique 1 comprend, dans l'ordre suivant : un film optique 109 comprenant une couche adhésive ; un polariseur 101 dans lequel un colorant dichroïque est adsorbé et orienté dans un film de résine à base d'alcool polyvinylique ; une première couche de liaison 30a ; une plaque de retard 20 ; et une seconde couche de liaison 30b. Dans le stratifié optique 1, le film optique 109 comprenant la couche adhésive et le polariseur 101 sont en contact direct l'un avec l'autre. Dans le stratifié optique 1, le polariseur 101 et la première couche de liaison 30a sont en contact direct l'un avec l'autre. Une couche composée de la première couche de liaison 30a, de la plaque de retard 20 et de la seconde couche de liaison 30b a une absorbance de 0,1 ou plus par rapport à la lumière ayant une longueur d'onde de 340 nm.
PCT/JP2024/025633 2023-08-01 2024-07-17 Stratifié optique Pending WO2025028263A1 (fr)

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JP2023-125416 2023-08-01
JP2023125416 2023-08-01
JP2024016970A JP2025022695A (ja) 2023-08-01 2024-02-07 光学積層体
JP2024-016970 2024-02-07

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WO2025028263A1 true WO2025028263A1 (fr) 2025-02-06

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Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2021131504A1 (fr) * 2019-12-23 2021-07-01 住友化学株式会社 Corps multicouche optique et dispositif d'affichage d'image
WO2021131505A1 (fr) * 2019-12-23 2021-07-01 住友化学株式会社 Stratifié optique et dispositif d'affichage d'image
WO2021131506A1 (fr) * 2019-12-23 2021-07-01 住友化学株式会社 Stratifié optique et dispositif d'affichage d'image
JP2022101448A (ja) * 2020-12-24 2022-07-06 住友化学株式会社 円偏光板、光学積層体及び画像表示装置

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2021131504A1 (fr) * 2019-12-23 2021-07-01 住友化学株式会社 Corps multicouche optique et dispositif d'affichage d'image
WO2021131505A1 (fr) * 2019-12-23 2021-07-01 住友化学株式会社 Stratifié optique et dispositif d'affichage d'image
WO2021131506A1 (fr) * 2019-12-23 2021-07-01 住友化学株式会社 Stratifié optique et dispositif d'affichage d'image
JP2022101448A (ja) * 2020-12-24 2022-07-06 住友化学株式会社 円偏光板、光学積層体及び画像表示装置

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