Optical laminate and image display device
The optical laminate with a low-boron polarizer and light-selective adhesive layer addresses edge discoloration in polarizing plates, ensuring durability and color stability under harsh conditions.
Patent Information
- Application Number
- JP2025139054
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2019-12-23
- Filing Date
- 2025-08-22
- Publication Date
- 2025-11-26
AI Technical Summary
Polarizing plates used in image display devices are prone to discoloration at the edges under high-temperature and high-humidity environments, particularly when a protective film is laminated on only one side, and existing methods to enhance durability through increased boron content lead to shrinkage issues.
An optical laminate comprising a polarizer with a boron content of 5.0 mass% or less, a light-selective absorbing pressure-sensitive adhesive layer with specific absorbance and thickness, and optionally a protective film, which includes a λ/4 retardation layer to suppress color fading.
The optical laminate effectively prevents color loss at the edges of the polarizer under high-temperature and high-humidity conditions, maintaining durability and performance.
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Figure 2025172806000001_ABST
Abstract
Description
[Technical Field]
[0001] The present invention relates to an optical laminate and a display device. [Background technology]
[0002] Polarizing plates, which are made by laminating a protective film on one or both sides of a polarizer, are optical components that are widely used in image display devices such as liquid crystal displays (LCDs) and organic electroluminescence (OLED) displays, including mobile televisions, and in recent years, various mobile devices such as mobile phones, smartphones, and tablet terminals. Polarizing plates are often used by being attached to image display elements (liquid crystal cells, organic EL display elements, etc.) via a pressure-sensitive adhesive layer (for example, JP 2010-229321 A (Patent Document 1)). For this reason, polarizing plates are sometimes distributed on the market in the form of pressure-sensitive adhesive layer-attached polarizing plates, in which a pressure-sensitive adhesive layer is previously provided on one surface of the polarizing plate.
[0003] Furthermore, mobile devices are often used in harsh environments of high temperature and humidity, and polarizers are therefore required to have high durability. JP 2013-105036 A (Patent Document 2) describes that by increasing the boric acid content in a polarizer and generating a large amount of boric acid crosslinking, the I3 complex is highly oriented and highly stable, thereby suppressing the occurrence of blue leak and providing a polarizer with excellent low-temperature, high-humidity durability. [Prior art documents] [Patent documents]
[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2010-229321 [Patent Document 2] Japanese Patent Application Laid-Open No. 2013-105036 Summary of the Invention [Problem to be solved by the invention]
[0005] Polarizing plates have a problem in that discoloration is likely to occur at the edges of the polarizer under high-temperature and high-humidity environments. This problem is particularly pronounced in configurations in which a protective film is laminated to only one side of the polarizer. Although a method for suppressing discoloration of polarizers by increasing the boron content in the polarizer is known, this method has the problem of making the polarizer prone to shrinkage due to heating.
[0006] An object of the present invention is to provide a novel optical laminate in which color loss at the edges of a polarizer under high temperature and high humidity conditions is suppressed. [Means for solving the problem]
[0007] The present invention provides the optical laminates exemplified below and image displays using the same. [1] An optical laminate having a polarizer and a light-selective absorbing pressure-sensitive adhesive layer laminated in contact with the polarizer, the polarizer has iodine adsorbed and aligned, and a boron content of 5.0 mass% or less; The optical laminate, wherein the light-selective absorbing pressure-sensitive adhesive layer is formed from a pressure-sensitive adhesive composition containing a light-selective absorbing agent, and has an absorbance at a wavelength of 410 nm of 0.1 or more and 1.6 or less. [2] The optical laminate according to [1], further comprising a protective film laminated on the side of the polarizer opposite to the side of the light-selective absorbing pressure-sensitive adhesive layer. [3] The light-selective absorbing pressure-sensitive adhesive layer has a content of the light-selective absorbing agent per unit area of 0.01 g / m 2 More than 5g / m 2 The optical laminate according to [1] or [2], which is as follows: [4] The pressure-sensitive adhesive composition contains 0 parts by mass of the light-selective absorber relative to 100 parts by mass of the total resin components. An optical laminate described in any one of [1] to [3], containing 0.1 part by mass or more and 10 parts by mass or less. [5] The optical laminate according to any one of [1] to [4], wherein the light-selective absorptive pressure-sensitive adhesive layer has a thickness of 0.1 μm or more and 150 μm or less. [6] The optical layered body according to any one of [1] to [5], wherein the selective light absorber is an organic selective light absorber having a molecular weight of 100 or more and 3,000 or less. [7] The optical laminate according to any one of [1] to [6], further comprising a λ / 4 retardation layer laminated on the side of the light-selective absorptive pressure-sensitive adhesive layer opposite to the polarizer. [8] The optical laminate according to any one of [1] to [7], which is an anti-reflection polarizing plate. [9] An image display device comprising an image display panel and the optical laminate according to [8] arranged in front of the image display panel.
[10] The image display device according to [9], wherein the image display panel is an organic EL display panel. [Effects of the Invention]
[0008] According to the present invention, it is possible to provide an optical laminate in which color loss at the edges of a polarizer is suppressed under high-temperature and high-humidity environments, and an image display device including the same. [Brief explanation of the drawings]
[0009] [Figure 1] 1 is a schematic cross-sectional view showing an example of an optical laminate of the present invention. [Figure 2] FIG. 2 is a schematic cross-sectional view showing another example of the optical laminate of the present invention. [Figure 3] FIG. 10 is a diagram showing an example of an image observed with an optical microscope. [Figure 4] FIG. 10 is a diagram showing an example of data obtained by converting an observed image into 256 grayscale levels. DETAILED DESCRIPTION OF THE INVENTION
[0010] Hereinafter, embodiments of the present invention will be described with reference to the drawings, but the present invention is not limited to the following embodiments. In all of the drawings, the scales of the components are appropriately adjusted to make them easier to understand, and the scales of the components shown in the drawings do not necessarily match the scales of the actual components.
[0011] <Optical laminate> The optical laminate of the present invention has a polarizer and a light-selective absorbing pressure-sensitive adhesive layer laminated in contact with the polarizer. An example of the layer structure of the optical laminate of the present invention is shown in Figures 1 and 2. Fig. 1 is a schematic cross-sectional view of an example of the optical laminate of the present invention. The optical laminate 100 shown in Fig. 1 has a protective film 11, a polarizer 10, and a light-selective absorptive pressure-sensitive adhesive layer 20 in this order.
[0012] Fig. 2 is a schematic cross-sectional view of an example of the optical laminate of the present invention. The optical laminate 200 shown in Fig. 2 has the optical laminate 100 shown in Fig. 1 and a retardation laminate 300 laminated on the side of the lightselective absorbent pressure-sensitive adhesive layer 20 of the optical laminate 100. The retardation laminate 300 has, in order from the side of the lightselective absorbent pressure-sensitive adhesive layer 20 of the optical laminate 100, a first retardation layer 30, an adhesive layer 33, a second retardation layer 31, and a second pressure-sensitive adhesive layer 32.
[0013] The thickness of the optical laminates 100 and 200 is not particularly limited as it varies depending on the function required of the optical laminate and the use of the optical laminate, but is, for example, 5 μm or more and 200 μm or less, or 10 μm or more and 150 μm or less, or 120 μm or less.
[0014] The light-selective absorbing pressure-sensitive adhesive layer contains a light-selective absorbing agent. Since at least the light-selective absorbing pressure-sensitive adhesive layer has light-selective absorbing properties, the optical laminate of the present invention has light-selective absorbing properties as a whole. Therefore, when the optical layered body of the present invention is used on an image display element, it has the function of protecting the image display element from ultraviolet rays.
[0015] The optical laminate of the present invention may be configured to include a layer having light-selective absorption performance in addition to the light-selective absorbing pressure-sensitive adhesive layer. Examples of such other layers include a protective film 11. In the present invention, the light-selective absorbing pressure-sensitive adhesive layer has light-selective absorption performance and contributes to the development of light-selective absorption performance in the entire optical laminate, thereby improving the degree of freedom in designing the light-selective absorption performance of the other layers. For example, the protective film 11 may need to be designed to be thicker in order to improve its light-selective absorption performance, but the high degree of freedom in designing the light-selective absorption performance makes it easier to make the protective film 11 thinner.
[0016] The present inventors have found that there is a correlation between the content of the light-selective absorber contained in the pressure-sensitive adhesive layer and the degree of color fading at the edge of the polarizer under high temperature and high humidity. Based on this finding, it is believed that under high temperature and high humidity, the light-selective absorber in the pressure-sensitive adhesive layer tends to migrate toward the polarizer, and this migration is one of the factors that cause color fading. After further intensive research, the present inventors have found that even when the pressure-sensitive adhesive layer contains a light-selective absorber, color fading at the edge of the polarizer under high temperature and high humidity can be suppressed by adjusting the absorbance of the pressure-sensitive adhesive layer, and have arrived at the present invention.
[0017] [Polarizer] A polarizer has the property of absorbing linearly polarized light with a vibration plane parallel to its absorption axis and transmitting linearly polarized light with a vibration plane perpendicular to the absorption axis (parallel to the transmission axis). The polarizer 10 in the optical laminate of the present invention has iodine adsorbed and oriented, and the boron content is 5.0% by mass or less. A boron content of 5.0% by mass or less, preferably 4.5% by mass or less, can suppress shrinkage caused by heating. The boron content is preferably 0.5% by mass or more, more preferably 1% by mass or more. The lower the boron content in the polarizer 10, the more likely discoloration occurs at the edges of the polarizer under high temperature and high humidity conditions. Boron in the polarizer 10 improves the degree of crosslinking of the polarizer 10 and contributes to stably retaining iodine in the polarizer 10. Therefore, a decrease in the boron content is thought to make it difficult to stably retain iodine, resulting in discoloration. In the present invention, even if the polarizer 10 has a boron content of 5.0 mass % or less, color fading under high temperature and high humidity conditions can be suppressed.
[0018] Examples of the polarizer 10 include a stretched film or stretched layer adsorbed with a dichroic dye having absorption anisotropy, a cured product of a polymerizable liquid crystal compound, and a cured liquid crystal layer containing a dichroic dye. The dichroic dye is a dye having different absorbance in the long axis direction and the short axis direction of the molecule, and iodine is preferably used as the dye.
[0019] A polarizer, which is a stretched film or stretched layer having a dye having absorption anisotropy adsorbed thereon, can usually be produced through the steps of uniaxially stretching a polyvinyl alcohol-based resin film, dyeing the polyvinyl alcohol-based resin film with a dichroic dye such as iodine to adsorb the dichroic dye, treating the polyvinyl alcohol-based resin film having the adsorbed dichroic dye with an aqueous boric acid solution, and washing the film with water after the treatment with the aqueous boric acid solution.
[0020] The thickness of the polarizer is usually 30 μm or less, preferably 15 μm or less, more preferably 13 μm or less, even more preferably 10 μm or less, and particularly preferably 8 μm or less. The thickness of the polarizer is usually 2 μm or more, preferably 3 μm or more, and may be, for example, 5 μm or more.
[0021] Polyvinyl alcohol resins are obtained by saponifying polyvinyl acetate resins. Examples of polyvinyl acetate resins include polyvinyl acetate, which is a homopolymer of vinyl acetate, and copolymers of vinyl acetate with other monomers copolymerizable with it. Examples of other monomers copolymerizable with vinyl acetate include unsaturated carboxylic acid compounds, olefin compounds, vinyl ether compounds, unsaturated sulfone compounds, and (meth)acrylamide compounds having an ammonium group.
[0022] The saponification degree of the polyvinyl alcohol resin is usually about 85 mol% or more and 100 mol% or less, preferably 98 mol% or more. The polyvinyl alcohol resin may be modified, and polyvinyl formal, polyvinyl acetal, etc. modified with aldehydes can also be used. The polymerization degree of the polyvinyl alcohol resin is usually 1,000 or more and 10,000 or less, preferably 1,500 or more and 5,000 or less.
[0023] A polarizer, which is a stretched layer having an absorption anisotropy dye adsorbed thereon, can typically be produced by the following steps: applying a coating solution containing the polyvinyl alcohol resin onto a substrate film; uniaxially stretching the resulting laminate film; dyeing the polyvinyl alcohol resin layer of the uniaxially stretched laminate film with a dichroic dye such as iodine to adsorb the dichroic dye to form a polarizer; treating the film with the adsorbed dichroic dye in a boric acid aqueous solution; and washing the film with water after the boric acid aqueous solution treatment. The substrate film used to form the polarizer may also be used as a protective film 11. If necessary, the substrate film may be peeled off from the polarizer. The material and thickness of the substrate film may be the same as those of the protective film 11 described below.
[0024] [Protection film] The protective film 11 can be a coating layer or film made of an optically transparent thermoplastic resin, such as a cyclic polyolefin resin; a cellulose acetate resin made of a resin such as triacetyl cellulose or diacetyl cellulose; a polyester resin made of a resin such as polyethylene terephthalate, polyethylene naphthalate, or polybutylene terephthalate; a polycarbonate resin; a (meth)acrylic resin; a polypropylene resin, or a mixture of one or more of these. The protective film 11 may contain a light-selective absorber, which will be described later. Note that the light-selective absorber contained in the protective film 11 is retained within the protective film 11 and is therefore unlikely to migrate to the polarizer.
[0025] A hard coat layer may be formed on the protective film 11. The hard coat layer may be formed on one side or both sides of the protective film 11. By providing a hard coat layer, the protective film 11 can be improved in hardness and scratch resistance. The hard coat layer may be a cured layer of, for example, an acrylic resin, a silicone resin, a polyester resin, a urethane resin, an amide resin, or an epoxy resin. The hard coat layer may contain an additive to improve strength. The additive is not limited, and examples include inorganic fine particles, organic fine particles, and mixtures thereof. The hard coat layer is, for example, a cured layer of an ultraviolet-curable resin. Examples of ultraviolet-curable resins include an acrylic resin, a silicone resin, a polyester resin, a urethane resin, an amide resin, and an epoxy resin.
[0026] The thickness of the protective film is usually 1 to 100 μm, but (from the viewpoint of strength, handling, etc.) it is preferably 5 to 80 μm, more preferably 8 to 60 μm, and even more preferably 12 to 45 μm.
[0027] The resin film serving as the protective film 11 is attached to the polarizer 10 via, for example, an adhesive layer. Examples of the adhesive that forms the adhesive layer include a water-based adhesive and an active energy ray-curable adhesive. The adhesive may be a water-based adhesive or a heat-curable adhesive, and it is preferable to use an aqueous adhesive or an active energy ray-curable adhesive. The two opposing surfaces to be bonded together via the adhesive layer may be previously subjected to corona treatment, plasma treatment, flame treatment, or the like, or may have a primer layer or the like.
[0028] [Photoselective absorption adhesive layer] The photoselective absorption pressure-sensitive adhesive layer 20 can be formed by applying a diluted solution of the pressure-sensitive adhesive composition dissolved or dispersed in an organic solvent onto a substrate and drying the diluted solution. A suitable substrate is a plastic film, and a specific example of such a substrate is a release film that has been subjected to a release treatment. An example of a release film is a film made of a resin such as polyethylene terephthalate, polybutylene terephthalate, polycarbonate, or polyarylate, with one side subjected to a release treatment such as silicone treatment.
[0029] The thickness of the photoselective absorbent pressure-sensitive adhesive layer is, for example, 0.1 μm or more and 150 μm or less. When laminated with an image display panel, it is usually 8 μm or more and 60 μm or less, and from the viewpoint of thinning, it is preferably 30 μm or less, further 25 μm or less, and particularly preferably 20 μm or less. When laminated with another optical film, for example, a λ / 4 retardation layer, it is usually 2 μm or more and 30 μm or less, preferably 25 μm or less, more preferably 20 μm or less, particularly preferably 18 μm or less, preferably 3 μm or more, and may be, for example, 10 μm or more, but from the viewpoint of further thinning, it is preferably 10 μm or less, particularly preferably 7 μm or less.
[0030] The light-selective absorbent pressure-sensitive adhesive layer preferably has an absorbance at a wavelength of 410 nm of 0.1 or more and 1.6 or less, more preferably 0.2 or more and 1.5 or less. When the light-selective absorbent pressure-sensitive adhesive layer 20 has such an absorbance, the optical laminate as a whole can exhibit the desired light-selective absorption performance while making it easier to configure the optical laminate as a whole thin.
[0031] The photoselective absorption pressure-sensitive adhesive layer is The absorbance at a wavelength of 390 nm is usually 5.0 or less, and may be 4.5 or less, The absorbance at a wavelength of 400 nm is usually 5.0 or less, and may be 4.5 or less, The absorbance at a wavelength of 420 nm is usually 1.00 or less, preferably 0.60 or less, more preferably 0.40 or less, and is 0.00 or more; The absorbance at a wavelength of 430 nm is usually less than 0.20, preferably 0.18 or less, more preferably 0.10 or less, particularly preferably 0.05 or less, and is 0.00 or more; The absorbance at a wavelength of 440 nm is usually less than 0.10, preferably 0.05 or less, and 0.00 or more. When the absorbance at each wavelength is within the above range, light in the ultraviolet region is sufficiently absorbed while light in the visible region can be transmitted as is.
[0032] The light-selective absorbing adhesive layer has a light-selective absorbing agent content of 0.01 g / m per unit area. 2 More than 5g / m 2 By setting the thickness within this range, color fading of the polarizer that occurs under high temperature and high humidity conditions can be suppressed.
[0033] [Adhesive composition] The pressure-sensitive adhesive composition preferably contains a resin and a photoselective absorber, and further contains a crosslinking agent. The resin is, for example, a resin whose main component is a (meth)acrylic, rubber, urethane, ester, silicone, or polyvinyl ether resin. Among these, a resin whose main component is a (meth)acrylic resin (A) is preferred.
[0034] (light selective absorber) The photoselective absorber selectively absorbs light of a specific wavelength, and has a wavelength of 360nm to 4 It is preferable to include a compound having at least one absorption maximum at 20 nm, and more preferable to include a compound having an absorption maximum between 380 nm and 410 nm.
[0035] Examples of light-selective absorbers containing a compound having an absorption maximum at a wavelength of around 350 nm (hereinafter, sometimes referred to as light-selective absorber (A)) include organic light-selective absorbers such as oxybenzophenone-based light-selective absorbers, benzotriazole-based light-selective absorbers, salicylic acid ester-based light-selective absorbers, benzophenone-based light-selective absorbers, cyanoacrylate-based light-selective absorbers, and triazine-based light-selective absorbers. More specific examples include 5-chloro-2-(3,5-di-sec-butyl-2-hydroxylphenyl)-2H-benzotriazole, (2-2H-benzotriazol-2-yl)-6-(linear and branched chain dodecyl)-4-methylphenol, 2-hydroxy-4-benzyloxybenzophenone, and 2,4-benzyloxybenzophenone. These organic light-selective absorbers may be used alone or in combination. The molecular weight of the organic light-selective absorber is preferably 100 to 3,000.
[0036] The light-selective absorber (A) may be a commercially available product. For example, triazine-based light-selective absorbers include "Kemisorb 102" manufactured by Chemipro Chemical Co., Ltd., "ADK STAB LA46" and "ADK 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. Examples of benzotriazole-based light-selective absorbers include "ADK STAB LA31" and "ADK STAB LA36" manufactured by ADEKA Corporation, and "SUMISORB" manufactured by Sumika Chemtex Co., Ltd. 200," "Sumisorb 250," "Sumisorb 300," "Sumisorb 340," and "Sumisorb 350," "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.
[0037] The light-selective absorber (A) may also be an inorganic light-selective absorber. Examples of inorganic light-selective 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), and ATO (antimony-doped tin oxide). Examples of titanium oxide-based composite oxides include zinc oxide doped with silica or alumina. These inorganic light-selective absorbers can be used alone or in combination of two or more. Furthermore, an organic light-selective absorber and an inorganic light-selective absorber may also be used in combination.
[0038] The light-selective absorber containing a compound having an absorption maximum at a wavelength of around 405 nm (hereinafter, sometimes referred to as light-selective absorber (B)) is preferably a compound satisfying the following formula (5), and more preferably a compound satisfying the following formula (6). ε(405)≧20 (5) (In equation (5), ε(405) represents the gram absorption coefficient of the compound at a wavelength of 405 nm. The unit of the gram absorption coefficient is L / (g cm).) ε(405) / ε(440)≧20 (6) [In formula (6), ε(405) represents the gram absorption coefficient of the compound at a wavelength of 405 nm, and ε(440) represents the gram absorption coefficient at a wavelength of 440 nm.] The gram absorbance coefficient is measured by the method described in the Examples.
[0039] The larger the value of ε(405), the easier it is for a compound to absorb light with a wavelength of 405 nm, and the more easily the compound can suppress the deterioration of the optical laminate and image display device due to ultraviolet light or short-wavelength visible light. If the ε(405) value is less than 20 L / (g·cm), the deterioration suppression function of retardation films and organic EL light-emitting devices due to ultraviolet light and short-wavelength visible light tends to be difficult to achieve unless the content of the photoselective absorber (B) in the pressure-sensitive adhesive composition is increased. The ε(405) value is preferably 20 L / (g·cm) or more, more preferably 30 L / (g·cm) or more, even more preferably 40 L / (g·cm) or more, and is usually 500 L / (g·cm) or less.
[0040] A compound with a larger value of ε(405) / ε(440) can absorb light around 405 nm without impairing the color expression of an image display device, and can suppress photodegradation of displays such as retardation films and organic EL elements. The value of ε(405) / ε(440) is preferably 20 or more, more preferably 40 or more, even more preferably 70 or more, and particularly preferably 80 or more.
[0041] The compound that selectively absorbs light with a wavelength of 405 nm is preferably a compound containing a merocyanine structure in the molecule. The molecular weight of the compound containing a merocyanine structure in the molecule is preferably 100 or more and 3000 or less. Examples of compounds containing a merocyanine structure in the molecule include compounds that contain a partial structure represented by -(NC=CC=C)- in the molecule, such as merocyanine compounds, cyanine compounds, indole compounds, and benzotriazole compounds. Merocyanine compounds, cyanine compounds, and benzotriazole compounds are preferred, and compounds represented by formula (I) are more preferred.
[0042] [ka] [In the formula, R 1 and R 5each independently represents a hydrogen atom, an alkyl group having 1 to 25 carbon atoms which may have a substituent, an aralkyl group having 7 to 15 carbon atoms which may have a substituent, an aryl group having 6 to 15 carbon atoms, or a heterocyclic group, and -CH2- contained in the alkyl group or aralkyl group is -NR 1A It may be substituted with -, -CO-, -SO2-, -O- or -S-. R 1A represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms. R 2 , R 3 and R 4 each independently represents a hydrogen atom, an alkyl group having 1 to 6 carbon atoms which may have a substituent, an aromatic hydrocarbon group which may have a substituent, or an aromatic heterocyclic group which may have a substituent, and -CH2- contained in the alkyl group is -NR 1 It may be substituted with -B-, -CO-, -SO2-, -O- or -S-. R1B represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms. R 6 and R 7 each independently represents a hydrogen atom, an alkyl group having 1 to 25 carbon atoms, or an electron-withdrawing group, or R 6 and R 7 may be linked to each other to form a ring structure. R 1 and R 2 may be linked together to form a ring structure, R 2 and R 3 may be linked together to form a ring structure, R 2 and R 4 may be linked together to form a ring structure, R 3 and R 6 may be linked to each other to form a ring structure.
[0043] R 1 and R 5 Examples of the alkyl group having 1 to 25 carbon atoms represented by the formula (I) include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, a 2-cyanopropyl group, an n-butyl group, a tert-butyl group, and Examples of the alkyl group include butyl, sec-butyl, n-pentyl, n-hexyl, 1-methylbutyl, 3-methylbutyl, n-octyl, n-decyl, and 2-hexyl-octyl groups. R 1 and R 5 Examples of the substituent that the alkyl group having 1 to 25 carbon atoms represented by the following formula (I) may have include groups described in group A below. Group A: a nitro group, a hydroxy group, a carboxy group, a sulfo group, a cyano group, an amino group, a halogen atom, an alkoxy group having 1 to 6 carbon atoms, an alkylsilyl group having 1 to 12 carbon atoms, an alkylcarbonyl group having 2 to 8 carbon atoms, *-R a1 -(OR a2 ) t1 -R a3 (R a1 and R a2 each independently represents an alkanediyl group having 1 to 6 carbon atoms, and R a3 represents an alkyl group having 1 to 6 carbon atoms, and t1 represents an integer of 1 to 3. Examples of the alkylsilyl group having 1 to 12 carbon atoms include monoalkylsilyl groups such as methylsilyl group, ethylsilyl group, and propylsilyl group; dialkylsilyl groups such as dimethylsilyl group, diethylsilyl group, and methylethylsilyl group; and trialkylsilyl groups such as trimethylsilyl group, triethylsilyl group, and tripropylsilyl group. Examples of the alkylcarbonyl group having 2 to 8 carbon atoms include a methylcarbonyl group and an ethylcarbonyl group. Examples of the halogen atom include a fluorine atom, a chlorine atom, and a bromine atom.
[0044] R 1 and R 5 Examples of the aralkyl group having 7 to 15 carbon atoms represented by the formula (I) include a benzyl group, a phenylethyl group, etc. Examples of the group in which -CH2- in the aralkyl group is replaced with -SO2- or -COO- include 2-phenylethyl acetate. R 1 and R 5Examples of the substituent that the aralkyl group having 7 to 15 carbon atoms represented by the following formula may have include the groups described in group A above. R 1 and R 5 Examples of the aryl group having 6 to 15 carbon atoms represented by the formula (I) include a phenyl group, a naphthyl group, and an anthracenyl group. R 1 and R 5 Examples of the substituent that the aryl group having 6 to 15 carbon atoms represented by the following formula may have include the groups described in group A above. R 1 and R 5 Examples of the heterocyclic group having 6 to 15 carbon atoms represented by the formula (I) include aromatic heterocyclic groups having 3 to 9 carbon atoms such as a pyridyl group, a pyrrolidyl group, a quinolyl group, a thiophene group, an imidazolyl group, an oxazolyl group, a pyrrole group, a thiazolyl group, and a furanyl group.
[0045] R 1A and R 1B Examples of the alkyl group having 1 to 6 carbon atoms represented by the formula (I) include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a tert-butyl group, a sec-butyl group, an n-pentyl group, and an n-hexyl group.
[0046] R 2 , R 3 and R 4 Examples of the alkyl group having 1 to 6 carbon atoms represented by the formula: 1B Examples include the same alkyl groups having 1 to 6 carbon atoms as those represented by the following formula: R 2 , R 3 and R 4 Examples of the substituent that the alkyl group having 1 to 6 carbon atoms represented by the following formula may have include the groups described in Group A above. R 2 , R 3 and R 4 Examples of the aromatic hydrocarbon group represented by the formula include aryl groups having 6 to 15 carbon atoms, such as a phenyl group, a naphthyl group, and an anthracenyl group; and aralkyl groups having 7 to 15 carbon atoms, such as a benzyl group and a phenylethyl group. R 2 , R 3and R 4 Examples of the substituent that the aromatic hydrocarbon group represented by the following formula may have include the groups described in Group A above. R 2 , R 3 and R 4 Examples of the aromatic heterocyclic ring represented by the formula (I) include aromatic heterocyclic groups having 3 to 9 carbon atoms, such as a pyridyl group, a pyrrolidyl group, a quinolyl group, a thiophene group, an imidazolyl group, an oxazolyl group, a pyrrole group, a thiazolyl group, and a furanyl group. R 2 , R 3 and R 4 Examples of the substituent that the aromatic heterocycle represented by the following formula (I) may have include the groups described in Group A above.
[0047] R 6 and R 7 As the alkyl group having 1 to 25 carbon atoms represented by the formula 1 and R 5 Examples include the same alkyl groups having 1 to 25 carbon atoms as those represented by the following formula: R 6 and R 7 Examples of the substituent that the alkyl group having 1 to 25 carbon atoms represented by the following formula may have include the groups described in group A above.
[0048] R 6 and R 7 As the alkyl group having 1 to 25 carbon atoms represented by the formula 1 and R 5 Examples include the same alkyl groups having 1 to 25 carbon atoms as those represented by the following formula: R 6 and R 7 Examples of the electron-withdrawing group represented by the formula (I-1) include a cyano group, a nitro group, a halogen atom, an alkyl group substituted with a halogen atom, and a group represented by the formula (I-1).
[0049] [ka] [In the formula, R 11represents a hydrogen atom or an alkyl group having 1 to 25 carbon atoms, and at least one methylene group contained in the alkyl group may be substituted with an oxygen atom. X 1 -CO-, -COO-, -OCO-, -CS-, -CSO-, -CSS-, -NR 12 It represents CO- or CONR13-. R 12 and R 13 each independently represents a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or a phenyl group.]
[0050] Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. Examples of the alkyl group substituted with a halogen atom include perfluoroalkyl groups such as a trifluoromethyl group, a perfluoroethyl group, a perfluoropropyl group, a perfluoroisopropyl group, a perfluorobutyl group, a perfluorosec-butyl group, a perfluorotert-butyl group, a perfluoropentyl group, and a perfluorohexyl group. The number of carbon atoms in the alkyl group substituted with a halogen atom is usually 1 to 25.
[0051] R 6 and R 7 may be linked together to form a ring structure, and R 6 and R 7 Examples of the ring structure formed by the above include a Meldrum's acid structure, a barbituric acid structure, and a dimedone structure. R 11 As the alkyl group having 1 to 25 carbon atoms represented by the formula 1 and R 5 The alkyl group may be the same as the alkyl group represented by the following formula:
[0052] R 2 and R3 bonded to each other to form a ring structure, R 2 and examples thereof include 4- to 14-membered nitrogen-containing heterocyclic rings. 2 and R 3The ring structure formed by linking together may be a monocyclic ring or a polycyclic ring, and specific examples thereof include a pyrrolidine ring, a pyrroline ring, an imidazolidine ring, an imidazoline ring, an oxazoline ring, a thiazoline ring, a piperidine ring, a morpholine ring, a piperazine ring, an indole ring, and an isoindole ring.
[0053] R 1 and R 2 The ring structure formed by bonding together is R 1 and R 2 is a nitrogen-containing ring structure containing a nitrogen atom to which R is bonded, and examples thereof include a 4- to 14-membered (preferably 4- to 8-membered) nitrogen-containing heterocycle. 1 and R 2 The ring structure formed by linking R may be a monocyclic ring or a polycyclic ring. 2 and R 3 The ring structure formed by linking these groups together is also included.
[0054] R 2 and R 4 The ring structure formed by bonding together includes a 4- to 14-membered nitrogen-containing ring structure. R is a 5- to 9-membered nitrogen-containing ring structure. 2 and R 4 The ring structure formed by bonding together may be a monocyclic ring or a polycyclic ring. These rings may have a substituent. Examples of such ring structures include the above-mentioned R 2 and R 3 Examples of the ring structure formed by the formula include the same as those exemplified above.
[0055] R 3 and R 6 The ring structure formed by linking these is R 3 -C=CC=CR 6 is a ring structure that forms the skeleton of the ring. For example, a phenyl group can be mentioned.
[0056] R 2 and R 3The compound represented by formula (I) in which R are linked to each other to form a ring structure includes a compound represented by formula (IA), 2 and R 4 Examples of the compound represented by formula (I) in which are linked to each other to form a ring structure include a compound represented by formula (IB).
[0057] [ka] [In formula (IA) and formula (IB), R 1 , R 3 , R 4 , R 5 , R 6 and R 7 have the same meanings as above. Ring W 1 and Ring W 2 each independently represents a nitrogen-containing ring.
[0058] Ring W 1 and Ring W 2 represents a nitrogen-containing ring containing a nitrogen atom as a constituent unit of the ring. Ring W 1 and Ring W 2 may each independently be a monocyclic ring or a polycyclic ring, and may contain a heteroatom other than nitrogen as a ring constituent unit. 1 and Ring W 2 are preferably each independently a 5- to 9-membered ring.
[0059] The compound represented by formula (IA) is preferably a compound represented by formula (IA-1). [ka] [In formula (IA-1), R 1 , R 4 , R 5 , R 6 and R 7 have the same meanings as above. A 1 is -CH2-, -O-, -S- or -NR 1 Represents D-. R 14 and R 15 each independently represents a hydrogen atom or an alkyl group having 1 to 12 carbon atoms. R 1D represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms.]
[0060] The compound represented by formula (IB) is preferably a compound represented by formula (IB-1) or a compound represented by formula (IB-2). [ka] [In formula (IB-1), R 1 , R 6 and R 7 have the same meanings as above. R 16 each independently represents a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, or an aryl group.]
[0061] [ka] [In formula (IB-2), R 3 , R 5 , R 6 and R 7 have the same meanings as above. R 30 represents a hydrogen atom, a cyano group, a nitro group, a halogen atom, a mercapto group, an amino group, an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, an acyl group having 2 to 13 carbon atoms, an acyloxy group having 2 to 13 carbon atoms, or an alkoxycarbonyl group having 2 to 13 carbon atoms. R 31 represents an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, a mercapto group, an alkylthio group having 1 to 12 carbon atoms, an amino group which may have a substituent, or a heterocyclic group.]
[0062] R 30Examples of the halogen atom represented by the formula (I) include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. R 30 R expressed as 30 Examples of the acyl group having 2 to 13 carbon atoms represented by the formula include an acetyl group, a propionyl group, and a butyryl group. R 30 Examples of the acyloxy group having 2 to 13 carbon atoms represented by the formula include a methylcarbonyloxy group, an ethylcarbonyloxy group, a propylcarbonyloxy group, and a butylcarbonyloxy group. R 30 Examples of the alkoxycarbonyl group having 2 to 13 carbon atoms represented by the formula include a methoxycarbonyl group, an ethoxycarbonyl group, a propoxycarbonyl group, and a butoxycarbonyl group. R 30 Examples of the aromatic hydrocarbon group having 6 to 18 carbon atoms represented by the formula (I) include aryl groups having 6 to 18 carbon atoms such as a phenyl group, a naphthyl group, and a biphenyl group; and aralkyl groups having 7 to 18 carbon atoms such as a benzyl group and a phenylethyl group. R 30 Examples of the alkyl group having 1 to 12 carbon atoms represented by the formula: 14 Examples include the same alkyl groups having 1 to 12 carbon atoms as those represented by the following formula: R 30 Examples of the alkyl group having 1 to 12 carbon atoms represented by the formula include a methoxy group, an ethoxy group, a propoxy group, a butoxy group, and a pentoxy group. R 30 is preferably an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, an amino group, or a mercapto group.
[0063] R 31 Examples of the alkyl group having 1 to 12 carbon atoms represented by the formula: 14 Examples include the same alkyl groups having 1 to 12 carbon atoms as those represented by the following formula: R 31 The alkoxy group having 1 to 12 carbon atoms represented by R 30 Examples of the alkoxy group include the same alkoxy groups having 1 to 12 carbon atoms as those represented by the following formula: R 31Examples of the alkylthio group having 1 to 12 carbon atoms represented by the formula (I) include a methylthio group, an ethylthio group, a propylthio group, a butylthio group, a pentylthio group, and a hexylthio group. R 31 Examples of the optionally substituted amino group represented by the formula (I) include an amino group; an amino group substituted with one alkyl group having 1 to 8 carbon atoms, such as an N-methylamino group or an N-ethylamino group; and an amino group substituted with two alkyl groups having 1 to 8 carbon atoms, such as an N,N-dimethylamino group, an N,N-diethylamino group or an N,N-methylethylamino group. R 31 Examples of the heterocyclic ring represented by the formula (I) include nitrogen-containing heterocyclic groups having 4 to 9 carbon atoms, such as a pyrrolidinyl group, a piperidinyl group, and a morpholinyl group.
[0064] R 3 and R 6 are linked together to form a ring structure, and R 2 and R 4 Examples of the compound represented by formula (I) in which are bonded to each other to form a ring structure include a compound represented by formula (IC). [ka] [In formula (IC), R 1 , R 6 and R 7 has the same meaning as above. R 21 , R 22 each independently represents a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, or a hydroxy group. X 2 and X 3 are each independently -CH2- or -N(R 25 )=. R 25 represents a hydrogen atom, an alkyl group having 1 to 25 carbon atoms, or an aromatic hydrocarbon group which may have a substituent.]
[0065] R 25 As the alkyl group having 1 to 25 carbon atoms represented by the formula 1Examples include the same alkyl groups having 1 to 25 carbon atoms as those represented by the following formula: R 25 Examples of the aromatic hydrocarbon group represented by R include aryl groups such as phenyl and naphthyl groups, aralkyl groups such as benzyl and phenylethyl groups, and biphenyl groups, and are preferably aromatic hydrocarbon groups having 6 to 20 carbon atoms. 25 Examples of the substituent that the aromatic hydrocarbon group represented by the following formula may have include a hydroxy group.
[0066] R 3 and R 6 are preferably each independently an electron-withdrawing group.
[0067] R 1 and R 2 are linked together to form a ring structure, and R 3 and R 6 Examples of the compound represented by formula (I) in which are bonded to each other to form a ring structure include a compound represented by formula (ID).
[0068] [ka] [In formula (ID), R 4 , R 5 , R 7 has the same meaning as above. R 25 , R 26 , R 27 and R 28 each independently represents a hydrogen atom, an alkyl group having 1 to 12 carbon atoms which may have a substituent, a hydroxy group, or an aralkyl group.]
[0069] R 25 , R 26 , R 27 and R 28 Examples of the alkyl group having 1 to 12 carbon atoms represented by the formula: 1A and R 1B The alkyl groups having 1 to 12 carbon atoms represented by R 25 , R 26 , R27 and R 28 Examples of the substituent that the alkyl group having 1 to 12 carbon atoms represented by the following formula may have include a hydroxy group. R 25 , R 26 , R 27 and R 28 Examples of the aralkyl group represented by the formula (I) include aralkyl groups having 7 to 15 carbon atoms such as a benzyl group and a phenylethyl group.
[0070] R 6 and R 7 Examples of compound (I) in which are linked to each other to form a ring structure include compounds represented by formula (IE).
[0071] [ka] [In formula (IE), R 1 , R 2 , R 3 , R 4 , R 5 have the same meaning as above. Ring W 3 represents a cyclic compound] Ring W 3 is a 5- to 9-membered ring, which may contain a heteroatom such as a nitrogen atom, an oxygen atom or a sulfur atom as a constituent unit of the ring.
[0072] The compound represented by formula (IE) is preferably a compound represented by formula (IE-1). [ka] [In formula (IE-1), R 1 , R 2 , R 3 and R 5 have the same meanings as above. R 17 , R 18 , R 19 , R qeach independently represents a hydrogen atom or an alkyl group, aralkyl group, or aryl group having 1 to 12 carbon atoms which may have a substituent, and a -CH2- group contained in the alkyl group or aralkyl group is -NR 1D -, -C(=O)-, -C(=S)-, -O-, or -S-; R 17 and R 18 may be linked together to form a ring structure, R 18 and R 19 may be linked together to form a ring structure, R 19 and R q may be linked to each other to form a ring structure. m, p, and q each independently represent an integer of 0 to 3.]
[0073] Examples of the compound represented by formula (I) include the following compounds. [ka]
[0074] [ka] TIFF2025172806000014.tif3170
[0075] [ka]
[0076] [ka]
[0077] [ka]
[0078] [ka]
[0079] [ka]
[0080] [ka]
[0081] [ka]
[0082] [ka]
[0083] The total content of the photoselective absorber is not limited as long as it is selected so that the absorbance of the adhesive layer at a wavelength of 410 nm is 0.1 or more and 1.6 or less. In the adhesive composition, the total content is, for example, 0.01 to 20 parts by mass, preferably 0.05 to 15 parts by mass, and more preferably 0.1 to 10 parts by mass, per 100 parts by mass of the total resin components. The mass ratio of the light-selective absorber (A) to the light-selective absorber (B) (light-selective absorber (A) / light-selective absorber (B)) is usually 0.05-20, and preferably 0.1-10.
[0084] ((Meth)acrylic resin (A)) The (meth)acrylic resin (A) is preferably a polymer containing, as the main component (preferably containing 50% by mass or more) a structural unit derived from a (meth)acrylic acid ester. The structural unit derived from a (meth)acrylic acid ester may contain one or more structural units derived from a monomer other than a (meth)acrylic acid ester (for example, a structural unit derived from a monomer having a polar functional group). In this specification, (meth)acrylic acid refers to acrylic acid or methacrylic acid. The term "(meth)acrylate" also has the same meaning.
[0085] Examples of the (meth)acrylic acid ester include (meth)acrylic acid esters represented by the following formula (X): [ka] [In formula (X), R 101 represents a hydrogen atom or a methyl group, and R 102 represents an alkyl group having 1 to 14 carbon atoms or an aralkyl group having 7 to 20 carbon atoms, and a hydrogen atom of the alkyl group or the aralkyl group may be substituted with an alkoxy group having 1 to 10 carbon atoms.]
[0086] In formula (X), R 102 is preferably an alkyl group having 1 to 14 carbon atoms, and more preferably an alkyl group having 1 to 8 carbon atoms.
[0087] The (meth)acrylic acid ester represented by formula (X) includes: linear alkyl esters of (meth)acrylic acid, such as methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, n-butyl (meth)acrylate, n-pentyl (meth)acrylate, n-hexyl (meth)acrylate, n-heptyl (meth)acrylate, n-octyl (meth)acrylate, n-nonyl (meth)acrylate, n-decyl (meth)acrylate, n-dodecyl (meth)acrylate, lauryl (meth)acrylate, and stearyl (meth)acrylate; branched alkyl esters of (meth)acrylic acid, such as i-propyl (meth)acrylate, i-butyl (meth)acrylate, t-butyl (meth)acrylate, i-pentyl (meth)acrylate, i-hexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, i-octyl (meth)acrylate, i-nonyl (meth)acrylate, i-stearyl (meth)acrylate, and i-amyl (meth)acrylate; alicyclic skeleton-containing alkyl esters of (meth)acrylic acid, such as cyclohexyl (meth)acrylate, isobornyl (meth)acrylate, adamantyl (meth)acrylate, dicyclopentanyl (meth)acrylate, cyclododecyl (meth)acrylate, methylcyclohexyl (meth)acrylate, trimethylcyclohexyl (meth)acrylate, tert-butylcyclohexyl (meth)acrylate, and cyclohexyl α-ethoxyacrylate; Aromatic ring skeleton-containing esters of (meth)acrylic acid such as phenyl (meth)acrylate; etc. Further examples include substituted alkyl (meth)acrylates in which a substituent has been introduced into the alkyl group of the alkyl (meth)acrylate. The substituent of the alkyl (meth)acrylate is a group that substitutes a hydrogen atom of the alkyl group, and specific examples thereof include a phenyl group, an alkoxy group, and a phenoxy group. Specific examples of alkyl (meth)acrylates in which a substituent has been introduced into the alkyl group of the alkyl (meth)acrylate include 2-methoxyethyl (meth)acrylate, ethoxymethyl (meth)acrylate, phenoxyethyl (meth)acrylate, 2-(2-phenoxyethoxy)ethyl (meth)acrylate, phenoxydiethylene glycol (meth)acrylate, and phenoxypoly(ethylene glycol) (meth)acrylate. can be.
[0088] These (meth)acrylic acid esters may be used alone or in combination of two or more different types.
[0089] The (meth)acrylic resin (A) preferably contains a structural unit derived from an acrylate alkyl ester (a1) whose homopolymer has a glass transition temperature (Tg) of less than 0°C, and a structural unit derived from an acrylate alkyl ester (a2) whose homopolymer has a Tg of 0°C or higher. The inclusion of a structural unit derived from an acrylate alkyl ester (a1) and a structural unit derived from an acrylate alkyl ester (a2) is advantageous in terms of improving the high-temperature durability of the pressure-sensitive adhesive layer. The Tg of the (meth)acrylic acid alkyl ester homopolymer can be, for example, a literature value such as that found in POLYMER HANDBOOK (Wiley-Interscience).
[0090] Specific examples of the alkyl acrylate (a1) include alkyl acrylates having an alkyl group carbon number of about 2 to 12, such as ethyl acrylate, n- and i-propyl acrylate, n- and i-butyl acrylate, n-pentyl acrylate, n- and i-hexyl acrylate, n-heptyl acrylate, n- and i-octyl acrylate, 2-ethylhexyl acrylate, n- and i-nonyl acrylate, n- and i-decyl acrylate, and n-dodecyl acrylate.
[0091] The acrylic acid alkyl ester (a1) may be used alone or in combination of two or more. Among them, n-butyl acrylate, n-octyl acrylate, 2-ethylhexyl acrylate, etc. are preferred from the viewpoints of followability and reworkability when the pressure-sensitive adhesive layer of the present invention is laminated on an optical laminate.
[0092] The alkyl acrylate (a2) is an alkyl acrylate other than the alkyl acrylate (a1). Specific examples of the alkyl acrylate (a2) include methyl acrylate, cyclohexyl acrylate, isobornyl acrylate, stearyl acrylate, t-butyl acrylate, etc.
[0093] The acrylic acid alkyl ester (a2) may be used alone or in combination of two or more. Among them, from the viewpoint of high temperature durability, the acrylic acid alkyl ester (a2) preferably contains methyl acrylate, cyclohexyl acrylate, isobornyl acrylate, etc., and more preferably contains methyl acrylate.
[0094] The structural units derived from the (meth)acrylic acid ester represented by formula (I) preferably account for 50% by mass or more, more preferably 60 to 95% by mass, and even more preferably 65 to 95% by mass or more of all structural units contained in the (meth)acrylic resin.
[0095] The structural unit derived from a monomer other than a (meth)acrylic acid ester is preferably a structural unit derived from a monomer having a polar functional group, more preferably a structural unit derived from a (meth)acrylic acid ester having a polar functional group. Examples of the polar functional group include a hydroxyl group, a carboxyl group, a substituted or unsubstituted amino group, and a heterocyclic group such as an epoxy group. Examples of the monomer having a polar functional group include: 1-Hydroxymethyl (meth)acrylate, 1-hydroxyethyl (meth)acrylate, 1-hydroxyheptyl (meth)acrylate, 1-hydroxybutyl (meth)acrylate, 1-hydroxypentyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 2-hydroxypentyl (meth)acrylate, 2-hydroxy (meth)acrylate Hexyl, 3-hydroxypropyl (meth)acrylate, 3-hydroxybutyl (meth)acrylate, 3-hydroxypentyl (meth)acrylate, 3-hydroxyhexyl (meth)acrylate, 3-hydroxyheptyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 4-hydroxypentyl (meth)acrylate, 4-hydroxyhexyl (meth)acrylate, 4-hydroxyheptyl (meth)acrylate, 4-hydroxyoctyl (meth)acrylate, 2-chloro-2-hydroxypropyl (meth)acrylate, (meth)acrylic acid 3-chloro-2-hydroxypropyl (meth)acrylate, 2-hydroxy-3-phenoxypropyl (meth)acrylate, 5-hydroxypentyl (meth)acrylate, 5-hydroxyhexyl (meth)acrylate, 5-hydroxyheptyl (meth)acrylate, 5-hydroxyoctyl (meth)acrylate, 5-hydroxynonyl (meth)acrylate, 6-hydroxyhexyl (meth)acrylate, 6-hydroxyheptyl (meth)acrylate, 6-hydroxyoctyl (meth)acrylate, 6-hydroxynonyl (meth)acrylate, 6-hydroxypropyl (meth)acrylate hydroxydecyl, 7-hydroxyheptyl (meth)acrylate, 7-hydroxyoctyl (meth)acrylate, 7-hydroxynonyl (meth)acrylate, 7-hydroxydecyl (meth)acrylate, 7-hydroxyundecyl (meth)acrylate, 8-hydroxyoctyl (meth)acrylate, 8-hydroxynonyl (meth)acrylate, 8-hydroxydecyl (meth)acrylate, 8-hydroxyundecyl (meth)acrylate, 8-hydroxydodecyl (meth)acrylate, 9-hydroxynonyl (meth)acrylate, 9-hydroxy(meth)acrylate acrylate, 10-hydroxydecyl (meth)acrylate, 10-hydroxyundecyl (meth)acrylate, 10-hydroxydodecyl (meth)acrylate, 10-hydroxytridecyl (meth)acrylate, 10-hydroxyundecyl (meth)acrylate, 10-hydroxydodecyl (meth)acrylate, 10-hydroxytridecyl acrylate, 10-hydroxytetradecyl (meth)acrylate, 11-hydroxyundecyl (meth)acrylate, 11-hydroxydodecyl (meth)acrylate, 11-hydroxytridecyl (meth)acrylate,Monomers having a hydroxy group, such as 11-hydroxytetradecyl (meth)acrylate, 11-hydroxypentadecyl (meth)acrylate, 12-hydroxydodecyl (meth)acrylate, 12-hydroxytridecyl (meth)acrylate, 12-hydroxytetradecyl (meth)acrylate, 13-hydroxypentadecyl (meth)acrylate, 13-hydroxytetradecyl (meth)acrylate, 13-hydroxypentadecyl (meth)acrylate, 14-hydroxytetradecyl (meth)acrylate, 14-hydroxypentadecyl (meth)acrylate, 15-hydroxypentadecyl (meth)acrylate, and 15-hydroxyheptadecyl (meth)acrylate; Monomers having a carboxyl group, such as (meth)acrylic acid, carboxyalkyl (meth)acrylates (for example, carboxyethyl (meth)acrylate, carboxypentyl (meth)acrylate), maleic acid, maleic anhydride, fumaric acid, and crotonic acid; Monomers having a heterocyclic group, such as acryloylmorpholine, vinylcaprolactam, N-vinyl-2-pyrrolidone, vinylpyridine, tetrahydrofurfuryl (meth)acrylate, caprolactone-modified tetrahydrofurfuryl acrylate, 3,4-epoxycyclohexylmethyl (meth)acrylate, glycidyl (meth)acrylate, and 2,5-dihydrofuran; Examples thereof include monomers having a substituted or unsubstituted amino group, such as aminoethyl (meth)acrylate, N,N-dimethylaminoethyl (meth)acrylate, and dimethylaminopropyl (meth)acrylate. Among these, from the viewpoint of the reactivity between the (meth)acrylic acid ester polymer and the crosslinking agent, a monomer having a hydroxy group or a monomer having a carboxyl group is preferred, and it is more preferred to include both a monomer having a hydroxy group and a monomer having a carboxyl group.
[0096] Monomers with hydroxy groups include 2-hydroxyethyl acrylate, acrylic acid 3-hydroxypropyl acrylate, 4-hydroxybutyl acrylate, 5-hydroxypentyl acrylate, and 6-hydroxyhexyl acrylate are preferred. In particular, good durability can be obtained by using 2-hydroxyethyl acrylate, 4-hydroxybutyl acrylate, and 5-hydroxypentyl acrylate. As the monomer having a carboxyl group, it is preferable to use acrylic acid.
[0097] From the viewpoint of preventing an increase in the peel strength of a separate film that can be laminated on the outer surface of the pressure-sensitive adhesive layer, it is preferable that the (meth)acrylic resin (A) is substantially free of structural units derived from monomers having an amino group, where "substantially free" means that the amount is 0.1 part by mass or less per 100 parts by mass of all structural units constituting the (meth)acrylic resin (a).
[0098] The content of the structural units derived from the monomer having a polar functional group is preferably 20 parts by mass or less, more preferably 0.5 parts by mass or more and 15 parts by mass or less, even more preferably 0.5 parts by mass or more and 10 parts by mass or less, and particularly preferably 1 part by mass or more and 7 parts by mass or less, relative to 100 parts by mass of all structural units of the (meth)acrylic resin (A).
[0099] The content of the structural units derived from the monomer having an aromatic group is preferably 20 parts by mass or less, more preferably 4 parts by mass or more and 20 parts by mass or less, and even more preferably 4 parts by mass or more and 16 parts by mass or less, relative to 100 parts by mass of all structural units of the (meth)acrylic resin (A).
[0100] Examples of structural units derived from monomers other than (meth)acrylic acid esters include structural units derived from styrene-based monomers, structural units derived from vinyl-based monomers, structural units derived from monomers having multiple (meth)acryloyl groups in the molecule, and structural units derived from (meth)acrylamide-based monomers.
[0101] Examples of styrene-based monomers include styrene; alkyl styrenes such as methylstyrene, dimethylstyrene, trimethylstyrene, ethylstyrene, diethylstyrene, triethylstyrene, propylstyrene, butylstyrene, hexylstyrene, heptylstyrene, and octylstyrene; halogenated styrenes such as fluorostyrene, chlorostyrene, bromostyrene, dibromostyrene, and iodostyrene; nitrostyrene; acetylstyrene; methoxystyrene; and divinylbenzene.
[0102] Examples of vinyl monomers include fatty acid vinyl esters such as vinyl acetate, vinyl propionate, vinyl butyrate, vinyl 2-ethylhexanoate, and vinyl laurate; vinyl halides such as vinyl chloride and vinyl bromide; vinylidene halides such as vinylidene chloride; nitrogen-containing heteroaromatic vinyls such as vinylpyridine, vinylpyrrolidone, and vinylcarbazole; conjugated dienes such as butadiene, isoprene, and chloroprene; and unsaturated nitriles such as acrylonitrile and methacrylonitrile.
[0103] Examples of monomers having multiple (meth)acryloyl groups in the molecule include monomers having two (meth)acryloyl groups in the molecule, such as 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,9-nonanediol di(meth)acrylate, ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, and tripropylene glycol di(meth)acrylate; and monomers having three (meth)acryloyl groups in the molecule, such as trimethylolpropane tri(meth)acrylate.
[0104] Examples of (meth)acrylamide monomers include N-methylol (meth)acrylamide, N-(2-hydroxyethyl) (meth)acrylamide, N-(3-hydroxypropyl) (meth)acrylamide, N-(4-hydroxybutyl) (meth)acrylamide, and N -(5-Hydroxypentyl)(meth)acrylamide, N-(6-hydroxyhexyl)(meth)acrylamide, N,N-dimethyl(meth)acrylamide, N,N-diethyl(meth)acrylamide, N-isopropyl(meth)acrylamide, N-(3-dimethylaminopropyl)(meth)acrylamide, N-(1,1-dimethyl-3-oxobutyl)(meth)acrylamide, N-[2-(2-oxo-1-imidazolidinyl)ethyl](meth)acrylamide, 2-acryloylamino-2-methyl-1-propanesulfonic acid, N-(methoxymethyl)acrylamide, N-(ethoxymethyl)(meth)acrylamide, N-(propoxymethyl)(meth)acrylamide, N-(1-methylethoxymethyl)(meth)acrylamide, N-(1-methyl N-(2-propoxymethyl)(meth)acrylamide, N-(2-methylpropoxymethyl)(meth)acrylamide, N-(butoxymethyl)(meth)acrylamide, N-(1,1-dimethylethoxymethyl)(meth)acrylamide, N-(2-methoxyethyl)(meth)acrylamide, N-(2-ethoxyethyl)(meth)acrylamide, N-(2-propoxyethyl)(meth)acrylamide, N-[2-(1-methylethoxy)ethyl](meth)acrylamide, N-[2-(1-methylpropoxy)ethyl](meth)acrylamide, N-[2-(2-methylpropoxy)ethyl](meth)acrylamide, N-(2-butoxyethyl)(meth)acrylamide, N-[2-(1,1-dimethylethoxy)ethyl](meth)acrylamide. Of these, N-(methoxymethyl)acrylamide, N-(ethoxymethyl)acrylamide, N-(propoxymethyl)acrylamide, N-(butoxymethyl)acrylamide and N-(2-methylpropoxymethyl)acrylamide are preferred.
[0105] The weight average molecular weight (Mw) of the (meth)acrylic resin (A) is preferably 500,000 to 2 The weight-average molecular weight is 500,000 or more. A weight-average molecular weight of 500,000 or more improves the durability of the pressure-sensitive adhesive layer in high-temperature environments, and facilitates the prevention of defects such as peeling between the adherend and the pressure-sensitive adhesive layer and cohesive failure of the pressure-sensitive adhesive layer. A weight-average molecular weight of 2,500,000 or less is advantageous in terms of coatability. From the viewpoint of achieving both the durability of the pressure-sensitive adhesive layer and the coatability of the pressure-sensitive adhesive composition, the weight-average molecular weight is preferably 600,000 to 1,800,000, more preferably 700,000 to 1,700,000, and particularly preferably 1,000,000 to 1,600,000. The molecular weight distribution (Mw / Mn), expressed as the ratio of the weight-average molecular weight (Mw) to the number-average molecular weight (Mn), is usually 2 to 10, preferably 3 to 8, and more preferably 3 to 6. The weight-average molecular weight can be analyzed by gel permeation chromatography and is expressed as a value converted into standard polystyrene.
[0106] When the (meth)acrylic acid resin (A) is dissolved in ethyl acetate to prepare a solution with a concentration of 20% by mass, the viscosity at 25°C is preferably 20 Pa·s or less, and more preferably 0.1 to 15 Pa·s. A viscosity in this range is advantageous from the viewpoint of coatability when the pressure-sensitive adhesive composition is applied to a substrate. The viscosity can be measured using a Brookfield viscometer.
[0107] The glass transition temperature (Tg) of the (meth)acrylic resin (A) may be, for example, -60 to 20°C, preferably -50 to 15°C, more preferably -45 to 10°C, and particularly -40 to 0°C. A Tg of not more than the upper limit is advantageous for improving the wettability of the pressure-sensitive adhesive layer to the adherend substrate, while a Tg of not less than the lower limit is advantageous for improving the durability of the pressure-sensitive adhesive layer. The glass transition temperature can be measured by a differential scanning calorimeter (DSC).
[0108] The (meth)acrylic resin (A) can be produced by known methods such as solution polymerization, bulk polymerization, suspension polymerization, and emulsion polymerization, with solution polymerization being particularly preferred. Examples of solution polymerization include mixing monomers and an organic solvent, adding a thermal polymerization initiator under a nitrogen atmosphere, and stirring for about 3 to 15 hours at a temperature of 40 to 90°C, preferably about 50 to 80°C. To control the reaction, the monomers and thermal polymerization initiator may be added continuously or intermittently during polymerization. A thermal initiator may be added. The monomer and the thermal initiator may be added in an organic solvent.
[0109] As the polymerization initiator, a thermal polymerization initiator or a photopolymerization initiator is used. Examples of the photopolymerization initiator include 4-(2-hydroxyethoxy)phenyl(2-hydroxy-2-propyl) ketone. Examples of the thermal polymerization initiator include azo compounds such as 2,2'-azobisisobutyronitrile, 2,2'-azobis(2-methylbutyronitrile), 1,1'-azobis(cyclohexane-1-carbonitrile), 2,2'-azobis(2,4-dimethylvaleronitrile), 2,2'-azobis(2,4-dimethyl-4-methoxyvaleronitrile), dimethyl-2,2'-azobis(2-methylpropionate), and 2,2'-azobis(2-hydroxymethylpropionitrile); lauryl Examples of suitable initiators include organic peroxides such as peroxide, t-butyl hydroperoxide, benzoyl peroxide, t-butyl peroxybenzoate, cumene hydroperoxide, diisopropyl peroxydicarbonate, dipropyl peroxydicarbonate, t-butyl peroxyneodecanoate, t-butyl peroxypivalate, and (3,5,5-trimethylhexanoyl) peroxide; and inorganic peroxides such as potassium persulfate, ammonium persulfate, and hydrogen peroxide. Redox initiators that combine a peroxide with a reducing agent can also be used.
[0110] The proportion of the polymerization initiator is about 0.001 to 5 parts by mass relative to 100 parts by mass of the total amount of the monomers constituting the (meth)acrylic resin (A). The (meth)acrylic resin may be polymerized using a polymerization method using active energy rays (such as ultraviolet rays).
[0111] Examples of organic solvents include aromatic hydrocarbons such as toluene and xylene; esters such as ethyl acetate and butyl acetate; aliphatic alcohols such as propyl alcohol and isopropyl alcohol; and ketones such as acetone, methyl ethyl ketone and methyl isobutyl ketone.
[0112] The content of the (meth)acrylic resin (A) is usually 60% by mass to 99.9% by mass, preferably 70% by mass to 99.5% by mass, and more preferably 80% by mass to 99% by mass, relative to 100% by mass of the pressure-sensitive adhesive composition.
[0113] The crosslinking agent (B) reacts with polar functional groups (e.g., hydroxyl groups, amino groups, carboxyl groups, heterocyclic groups, etc.) in the (meth)acrylic resin (A). The crosslinking agent (B) forms a crosslinked structure with the (meth)acrylic resin, etc., forming a crosslinked structure that is advantageous for durability and reworkability.
[0114] Examples of the crosslinking agent (B) include an isocyanate-based crosslinking agent, an epoxy-based crosslinking agent, an aziridine-based crosslinking agent, and a metal chelate-based crosslinking agent. In particular, from the viewpoints of the pot life of the pressure-sensitive adhesive composition, the durability of the pressure-sensitive adhesive layer, the crosslinking rate, etc., an isocyanate-based crosslinking agent is preferred.
[0115] The isocyanate compound is preferably a compound having at least two isocyanato groups (-NCO) in the molecule, and examples thereof include aliphatic isocyanate compounds (e.g., hexamethylene diisocyanate, etc.), alicyclic isocyanate compounds (e.g., isophorone diisocyanate, hydrogenated diphenylmethane diisocyanate, hydrogenated xylylene diisocyanate), and aromatic isocyanate compounds (e.g., tolylene diisocyanate, xylylene diisocyanate diphenylmethane diisocyanate, naphthalene diisocyanate, triphenylmethane triisocyanate, etc.). The crosslinking agent (B) may be an adduct of the isocyanate compound with a polyhydric alcohol compound (e.g., an adduct with glycerol, trimethylolpropane, etc.), an isocyanurate, a biuret compound, a polyether polyol, a polyester polyol, an acrylic polyol, a polybutadiene polyol, a polyisoprene polyol, etc., or a urethane obtained by addition reaction of the isocyanate compound with the polyhydric alcohol compound (e.g., an adduct with glycerol, trimethylolpropane, etc.). It may also be a derivative of a prepolymer-type isocyanate compound. The crosslinking agent (B) can be used alone or in combination of two or more. Representative examples of these include aromatic isocyanate compounds (e.g., tolylene diisocyanate, xylylene diisocyanate), aliphatic isocyanate compounds (e.g., hexamethylene diisocyanate), or their adducts with polyhydric alcohol compounds (e.g., glycerol, trimethylolpropane), or isocyanurates. When the crosslinking agent (B) is an aromatic isocyanate compound and / or an adduct of a polyhydric alcohol compound or an isocyanurate, this is advantageous for forming an optimal crosslink density (or crosslinked structure), and can improve the durability of the pressure-sensitive adhesive layer. In particular, when the crosslinking agent (B) is an adduct of a tolylene diisocyanate compound and / or an adduct of a polyhydric alcohol compound, it can improve durability, even when the pressure-sensitive adhesive layer is applied to a polarizing plate, for example.
[0116] The content of the crosslinking agent (B) is usually 0.01 to 15 parts by mass, preferably 0.05 to 10 parts by mass, and more preferably 0.1 to 5 parts by mass, based on 100 parts by mass of the (meth)acrylic resin (A).
[0117] The pressure-sensitive adhesive composition for forming the photoselective absorptive pressure-sensitive adhesive layer of the present invention may further contain a silane compound (D). Examples of the silane compound (D) include vinyltrimethoxysilane, vinyltriethoxysilane, vinyltris(2-methoxyethoxy)silane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropylethoxydimethylsilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-chloropropylmethyldimethoxysilane, 3-chloropropyltrimethoxysilane, 3-methacryloyloxypropyltrimethoxysilane, and 3-mercaptopropyltrimethoxysilane. The silane compound (D) may be a silicone oligomer. Specific examples of the silicone oligomer, expressed in the form of a combination of monomers, are as follows:
[0118] Mercaptopropyl group-containing oligomers such as 3-mercaptopropyltrimethoxysilane-tetramethoxysilane oligomer, 3-mercaptopropyltrimethoxysilane-tetraethoxysilane oligomer, 3-mercaptopropyltriethoxysilane-tetramethoxysilane oligomer, and 3-mercaptopropyltriethoxysilane-tetraethoxysilane oligomer; mercaptomethyl group-containing oligomers such as mercaptomethyltrimethoxysilane-tetramethoxysilane oligomer, mercaptomethyltrimethoxysilane-tetraethoxysilane oligomer, mercaptomethyltriethoxysilane-tetramethoxysilane oligomer, and mercaptomethyltriethoxysilane-tetraethoxysilane oligomer; 3-glycidoxypropyltrimethoxysilane-tetramethoxysilane copolymer, 3-glycidoxypropyltrimethoxysilane-tetraethoxysilane copolymer, and 3-glycidoxypropyltriethoxysilane- Copolymers containing 3-glycidoxypropyl groups such as tetramethoxysilane copolymer, 3-glycidoxypropyltriethoxysilane-tetraethoxysilane copolymer, 3-glycidoxypropylmethyldimethoxysilane-tetramethoxysilane copolymer, 3-glycidoxypropylmethyldimethoxysilane-tetraethoxysilane copolymer, 3-glycidoxypropylmethyldiethoxysilane-tetramethoxysilane copolymer, and 3-glycidoxypropylmethyldiethoxysilane-tetraethoxysilane copolymer; 3-methacryloyloxypropyltrimethoxysilane-tetramethoxysilane oligomer, 3-methacryloyloxypropyltrimethoxysilane-tetraethoxysilane oligomer, 3-methacryloyloxypropyltriethoxysilane-tetramethoxysilane oligomer, 3-methacryloyloxypropyltriethoxysilane-tetraethoxy ... methacryloyloxypropyl group-containing oligomers such as 3-acryloyloxypropyltrimethoxysilane-tetramethoxysilane oligomer, 3-methacryloyloxypropylmethyldimethoxysilane-tetraethoxysilane oligomer, 3-methacryloyloxypropylmethyldiethoxysilane-tetramethoxysilane oligomer, and 3-methacryloyloxypropylmethyldiethoxysilane-tetraethoxysilane oligomer; 3-acryloyloxypropyltrimethoxysilane-tetramethoxysilane oligomer, 3-acryloyloxypropyltrimethoxysilane-tetraethoxysilane oligomer, 3-acryloyloxypropyltriethoxysilane-tetramethoxysilane oligomer, 3-acryloyloxypropyltriethoxysilane-tetramethoxysilane oligomer, 3-acryloyloxypropyltriethoxysilane-tetraethoxysilane oligomer, 3-acryloyloxypropylmethyldimethoxysilane-tetramethoxysilane oligomer, and 3-acryloyloxypropylmethyldimethoxysilane-tetramethoxysilane oligomer. acryloyloxypropyl group-containing oligomers such as 3-acryloyloxypropylmethyldimethoxysilane-tetraethoxysilane oligomer, 3-acryloyloxypropylmethyldiethoxysilane-tetramethoxysilane oligomer, and 3-acryloyloxypropylmethyldiethoxysilane-tetraethoxysilane oligomer; vinyl group-containing oligomers such as vinyltrimethoxysilane-tetramethoxysilane oligomer, vinyltrimethoxysilane-tetraethoxysilane oligomer, vinyltriethoxysilane-tetramethoxysilane oligomer, vinyltriethoxysilane-tetraethoxysilane oligomer, vinylmethyldimethoxysilane-tetramethoxysilane oligomer, vinylmethyldimethoxysilane-tetraethoxysilane oligomer, vinylmethyldiethoxysilane-tetramethoxysilane oligomer, and vinylmethyldiethoxysilane-tetraethoxysilane oligomer;Amino group-containing copolymers such as 3-aminopropyltrimethoxysilane-tetramethoxysilane copolymer, 3-aminopropyltrimethoxysilane-tetraethoxysilane copolymer, 3-aminopropyltriethoxysilane-tetramethoxysilane copolymer, 3-aminopropyltriethoxysilane-tetraethoxysilane copolymer, 3-aminopropylmethyldimethoxysilane-tetramethoxysilane copolymer, 3-aminopropylmethyldimethoxysilane-tetraethoxysilane copolymer, 3-aminopropylmethyldiethoxysilane-tetramethoxysilane copolymer, 3-aminopropylmethyldiethoxysilane-tetraethoxysilane copolymer, and the like;
[0119] The silane compound (D) may be a silane compound represented by the following formula (d1): When the pressure-sensitive adhesive composition contains the silane compound represented by the following formula (d1), the adhesiveness to substrates, glass, transparent electrodes, etc. can be further improved, and therefore a pressure-sensitive adhesive layer with good durability that is less susceptible to peeling, foaming, etc. in high-temperature environments can be formed.
[0120] [ka] (In the formula, B represents an alkanediyl group having 1 to 20 carbon atoms or a divalent alicyclic hydrocarbon group having 3 to 20 carbon atoms, and —CH— constituting the alkanediyl group or the alicyclic hydrocarbon group may be substituted with —O— or —CO—; R d7 represents an alkyl group having 1 to 5 carbon atoms. , R d8 , R d9 , R d10 , R d11 and R d12 each independently represents an alkyl group having 1 to 5 carbon atoms or an alkoxy group having 1 to 5 carbon atoms.
[0121] In formula (d1), B represents an alkanediyl group having 1 to 20 carbon atoms, such as methylene, ethylene, trimethylene, tetramethylene, hexamethylene, heptamethylene, or octamethylene; a divalent alicyclic hydrocarbon group having 3 to 20 carbon atoms, such as a cyclobutylene group (e.g., 1,2-cyclobutylene), cyclopentylene group (e.g., 1,2-cyclopentylene), cyclohexylene group (e.g., 1,2-cyclohexylene), or cyclooctylene group (e.g., 1,2-cyclooctylene), or these alkanediyl groups and groups in which -CH2- constituting the alicyclic hydrocarbon group is replaced with -O- or -CO-. Preferably, B is an alkanediyl group having 1 to 10 carbon atoms. Rd7 represents an alkyl group having 1 to 5 carbon atoms, such as a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a s-butyl group, a t-butyl group, or a pentyl group, and R d8 , R d9 , R d10 , R d11 and R d12 are each independently the R 21 or an alkoxy group having 1 to 5 carbon atoms, such as a methoxy group, an ethoxy group, a propoxy group, an i-propoxy group, a butoxy group, an s-butoxy group, or a t-butoxy group. d8 , R d9 , R d10 , R d11 and R d12 are each independently an alkoxy group having 1 to 5 carbon atoms. These silane compounds (D) can be used alone or in combination of two or more.
[0122] Specific examples of the silane compound represented by the formula (d1) include bis(triC1) compounds such as (trimethoxysilyl)methane, 1,2-bis(trimethoxysilyl)ethane, 1,2-bis(triethoxysilyl)ethane, 1,3-bis(trimethoxysilyl)propane, 1,3-bis(triethoxysilyl)propane, 1,4-bis(trimethoxysilyl)butane, 1,4-bis(triethoxysilyl)butane, 1,5-bis(trimethoxysilyl)pentane, 1,5-bis(triethoxysilyl)pentane, 1,6-bis(trimethoxysilyl)hexane, 1,6-bis(triethoxysilyl)hexane, 1,6-bis(trippropoxysilyl)hexane, 1,8-bis(trimethoxysilyl)octane, 1,8-bis(triethoxysilyl)octane, and 1,8-bis(trippropoxysilyl)octane. bis(diC1-5 alkoxyC1-5 alkylsilyl)C1-10 alkanes such as bis(dimethoxymethylsilyl)methane, 1,2-bis(dimethoxymethylsilyl)ethane, 1,2-bis(dimethoxyethylsilyl)ethane, 1,4-bis(dimethoxymethylsilyl)butane, 1,4-bis(dimethoxyethylsilyl)butane, 1,6-bis(dimethoxymethylsilyl)hexane, 1,6-bis(dimethoxyethylsilyl)hexane, 1,8-bis(dimethoxymethylsilyl)octane, and 1,8-bis(dimethoxyethylsilyl)octane; and bis(monoC1-5 alkoxy-diC1-5 alkylsilyl)C1-10 alkanes such as 1,6-bis(methoxydimethylsilyl)hexane and 1,8-bis(methoxydimethylsilyl)octane. Of these, bis(triC1-3 alkoxysilyl)C1-10 alkanes such as 1,2-bis(trimethoxysilyl)ethane, 1,3-bis(trimethoxysilyl)propane, 1,4-bis(trimethoxysilyl)butane, 1,5-bis(trimethoxysilyl)pentane, 1,6-bis(trimethoxysilyl)hexane, and 1,8-bis(trimethoxysilyl)octane are preferred, and 1,6-bis(trimethoxysilyl)hexane and 1,8-bis(trimethoxysilyl)octane are particularly preferred.
[0123] The content of the silane compound (D) is usually 0.01 to 10 parts by mass, preferably 0.03 to 5 parts by mass, more preferably 0.05 to 2 parts by mass, and even more preferably 0.1 to 1 part by mass, relative to 100 parts by mass of the (meth)acrylic resin (A). An amount equal to or less than the upper limit is advantageous in suppressing bleed-out of the silane compound (A) from the pressure-sensitive adhesive layer, while an amount equal to or greater than the lower limit is advantageous in improving the adhesion (or bond) between the pressure-sensitive adhesive layer and a metal layer, glass substrate, or the like, and is advantageous in improving peel resistance, etc.
[0124] The pressure-sensitive adhesive composition may further contain an antistatic agent. Examples of antistatic agents include surfactants, siloxane compounds, conductive polymers, and ionic compounds, with ionic compounds being preferred. Examples of ionic compounds include conventional compounds. Examples of cationic components constituting the ionic compounds include organic cations and inorganic cations. Examples of organic cations include pyridinium cation, pyrrolidinium cation, piperidinium cation, imidazolium cation, ammonium cation, sulfonium cation, and phosphonium cation. Examples of inorganic cations 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. In particular, from the viewpoint of compatibility with (meth)acrylic resins, pyridinium cation, imidazolium cation, pyrrolidinium cation, lithium cation, and potassium cation are preferred. Examples of anionic components constituting the ionic compounds may be either inorganic or organic anions, but from the viewpoint of antistatic performance, an anionic component containing a fluorine atom is preferred. Examples of anion components containing fluorine atoms include hexafluorophosphate anion (PF6-), bis(trifluoromethanesulfonyl)imide anion [(CF3SO2)2N-], bis(fluorosulfonyl)imide anion [(FSO2)2N-], and tetra(pentafluorophenyl)borate anion [(CF6)4B-]. These ionic compounds can be used alone or in combination. Particularly preferred are bis(trifluoromethanesulfonyl)imide anion [(CF3SO2)2N-], bis(fluorosulfonyl)imide anion [(FSO2)2N-], and tetra(pentafluorophenyl)borate anion [(CF5)4B-]. In terms of the stability over time of the antistatic performance of the pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition, an ionic compound that is solid at room temperature is preferred.
[0125] 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 (A).
[0126] The pressure-sensitive adhesive composition may contain one or more additives such as a solvent, a crosslinking catalyst, a tackifier, a plasticizer, a softener, a pigment, a rust inhibitor, an inorganic filler, and light-scattering fine particles.
[0127] [Phase difference layer] The optical laminate of the present invention may further include a retardation layer laminated on the side of the light-selective absorbing pressure-sensitive adhesive layer opposite to the polarizer. The retardation layer may be one layer or two or more layers. The optical laminate 200 shown in FIG. 2 includes a first retardation layer 30 and a second retardation layer 31.
[0128] The retardation layer is an optical film exhibiting optical anisotropy. Examples of optical films exhibiting optical anisotropy include stretched films obtained by stretching polymer films made of polyvinyl alcohol, polycarbonate, polyester, polyarylate, polyimide, polyolefin, polycycloolefin, polystyrene, polysulfone, polyethersulfone, polyvinylidene fluoride / polymethyl methacrylate, acetyl cellulose, saponified ethylene-vinyl acetate copolymer, polyvinyl chloride, etc., by approximately 1.01 to 6 times. Among stretched films, polymer films obtained by uniaxially or biaxially stretching acetyl cellulose, polyester, polycarbonate film, or cycloolefin resin film are preferred. The retardation layer may also be a retardation layer made of a cured product of a polymerizable liquid crystal compound, which is formed by coating and orienting a polymerizable liquid crystal compound on a substrate to exhibit optical anisotropy.
[0129] In this specification, the retardation layer includes a retardation layer with zero retardation, and also includes films called uniaxial retardation films, low photoelasticity retardation films, wide viewing angle retardation films, and the like. A phase difference layer with zero retardation is one in which the front retardation Re and the thickness retardation The zero retardation film refers to an optically isotropic film in which the retardation Rth and the retardation Rth are both -15 to 15 nm. Examples of zero retardation films include resin films made of cellulose-based resins, polyolefin-based resins (such as linear polyolefin-based resins and polycycloolefin-based resins), or polyethylene terephthalate-based resins. Cellulose-based resins or polyolefin-based resins are preferred because they allow easy control of the retardation value and are readily available. Zero retardation films can also be used as protective films. Examples of zero retardation films include "Z-TAC" (trade name) sold by Fujifilm Corporation, "Zerotack (registered trademark)" sold by Konica Minolta Opto, Inc., and "ZF-14" (trade name) sold by Zeon Corporation.
[0130] In the optical laminate of the present invention, the retardation layer is preferably a retardation layer which is a cured product of a polymerizable liquid crystal compound. The retardation layer which is a cured product of a polymerizable liquid crystal compound includes first to fifth embodiments. First form: A retardation layer in which rod-like liquid crystal compounds are aligned horizontally to the supporting substrate Second form: Retardation layer in which rod-like liquid crystal compounds are aligned perpendicular to the substrate Third type: Retardation layer in which the direction of the rod-like liquid crystal molecules is helically oriented in the plane Fourth form: Retardation layer in which discotic liquid crystal compounds are tilted Fifth form: Biaxial retardation layer in which discotic liquid crystal compounds are aligned perpendicular to the substrate For example, the first, second and fifth embodiments are preferably used as optical films for organic electroluminescence displays, or retardation layers of these embodiments may be laminated and used.
[0131] When the retardation layer is a layer made of a polymer in an oriented state of a polymerizable liquid crystal compound (hereinafter, sometimes referred to as an "optically anisotropic layer"), the retardation layer preferably has reverse wavelength dispersion. Reverse wavelength dispersion is an optical property in which the in-plane retardation value of liquid crystal alignment at short wavelengths is smaller than the in-plane retardation value of liquid crystal alignment at long wavelengths, and preferably, the retardation film satisfies the following formulas (7) and (8). Here, Re(λ) represents the in-plane retardation value for light with a wavelength of λ nm. Re(450) / Re(550)≦1 (7) 1≦Re(630) / Re(550) (8) In the optical laminate of the present invention, when the retardation layer is in the first form and has reverse wavelength dispersion, coloration during black display on a display device is reduced, which is preferable, and in the formula (7), 0.82≦Re(450) / Re(550)≦0.93 is more preferable, and 120≦Re(550)≦150 is even more preferable.
[0132] Examples of the polymerizable liquid crystal compound used for forming the retardation layer include compounds having a polymerizable group among the compounds described in "3.8.6 Network (Completely Crosslinked)" and "6.5.1 Liquid Crystal Materials b. Polymerizable Nematic Liquid Crystal Materials" in Liquid Crystal Handbook (edited by Liquid Crystal Handbook Editorial Committee, published by Maruzen Co., Ltd. on October 30, 2000), as well as the polymerizable liquid crystal compounds described in JP 2010-31223 A, JP 2010-270108 A, JP 2011-6360 A, JP 2011-207765 A, JP 2011-162678 A, JP 2016-81035 A, WO 2017 / 043438 A and JP 2011-207765 A. A method for producing a retardation layer from a polymer in an oriented state of a polymerizable liquid crystal compound is, for example, Examples of such methods include the method described in JP-A-2010-31223.
[0133] The thickness of the retardation layer, which is a liquid crystal cured layer obtained by curing a polymerizable liquid crystal compound, is, for example, 0.1 μm to 10 μm, preferably 0.5 μm to 8 μm, and more preferably 1 μm to 6 μm.
[0134] Examples of retardation layers that exhibit optical anisotropy by coating and aligning a liquid crystal compound or that exhibit optical anisotropy by coating an inorganic layer compound include films called temperature-compensated retardation films, "NH film" (product name: film with obliquely aligned rod-shaped liquid crystals) sold by JX Nippon Oil & Energy Corporation, "WV film" (product name: film with obliquely aligned discotic liquid crystals) sold by Fujifilm Corporation, "VAC film" (product name: fully biaxially aligned film) sold by Sumitomo Chemical Co., Ltd., and "new VAC film" (product name: biaxially aligned film) sold by Sumitomo Chemical Co., Ltd. Examples include:
[0135] The retardation layer can be a λ / 4 retardation layer that imparts a retardation of ¼ wavelength to transmitted light, a λ / 2 retardation layer that imparts a retardation of ½ wavelength to transmitted light, a positive A plate, or a positive C plate. When the optical laminate 200 shown in Fig. 2 includes a first retardation layer 30 and a second retardation layer 31, examples of the combination of the first retardation layer 30 and the second retardation layer 31 include a combination of a λ / 2 retardation layer and a λ / 4 retardation layer, and a combination of a λ / 4 retardation layer and a positive C layer.
[0136] The optical laminate of the present invention may be configured as a circular polarizer having a λ / 4 retardation layer, and the circular polarizer can be used as an anti-reflection polarizer.
[0137] [Lamination layer] The optical laminate of the present invention can include a bonding layer for bonding two layers. Examples of the bonding layer include an adhesive layer and a pressure-sensitive adhesive layer (hereinafter also referred to as a "second pressure-sensitive adhesive layer"). The optical laminate 200 shown in Fig. 2 includes an adhesive layer 33 interposed between the first retardation layer 30 and the second retardation layer 31 to bond them together, and a second pressure-sensitive adhesive layer 32 laminated on the surface of the second retardation layer 31 opposite to the adhesive layer 33.
[0138] The adhesive layer may be a water-based adhesive, an active energy ray-curable adhesive, a thermosetting adhesive, etc. The thickness of the adhesive layer is, for example, 10 nm to 20 μm, preferably 100 nm to 10 μm, and more preferably 500 nm to 5 μm.
[0139] The second pressure-sensitive adhesive layer may be composed of a pressure-sensitive adhesive composition similar to the pressure-sensitive adhesive composition forming the above-mentioned photoselective absorption pressure-sensitive adhesive layer, or may be composed of a pressure-sensitive adhesive composition (hereinafter also referred to as "second pressure-sensitive adhesive composition") whose main component is a resin such as a (meth)acrylic, rubber, urethane, ester, silicone, or polyvinyl ether resin. The second pressure-sensitive adhesive composition is preferably a pressure-sensitive adhesive composition whose base polymer is a (meth)acrylic resin, which is excellent in transparency, weather resistance, heat resistance, etc. The second pressure-sensitive adhesive composition may be an active energy ray-curable or thermosetting type. The thickness of the second pressure-sensitive adhesive layer is, for example, 0.1 to 150 μm, typically 8 to 60 μm, and preferably 30 μm or less, and more preferably 20 μm or less, in terms of thinning.
[0140] <Method of manufacturing optical laminate> The optical laminates 100 and 200 can be produced by a method including a step of bonding the layers constituting the laminate 100 together via a bonding layer. When bonding the layers together via a bonding layer, it is preferable to perform a surface activation treatment such as a corona treatment on one or both of the bonding surfaces in order to improve adhesion.
[0141] <Optical laminate> The optical laminate of the present invention is planar and has an area of, for example, 30 mm × 30 mm to 180 mm × 90 mm. The optical laminate of the present invention may be rectangular, such as a rectangle or a square, or may have a so-called irregular shape, such as a shape having a notch formed by cutting out a part of a side constituting a rectangle, a semicircular shape, or a shape having a through-hole in the plane. When the outer shape of the optical laminate has straight sides, the absorption axis of the polarizer constituting the optical laminate may be parallel to the sides, or may be perpendicular to the sides, or may intersect obliquely, for example, at an angle of 45°. When the optical laminate has a retardation layer and this retardation layer has a slow axis in the plane, the slow axis may intersect with the absorption axis of the polarizer constituting the optical laminate at an angle of 45°, 15°, or 75°.
[0142] <Image display device> The optical laminates 100 and 200 are disposed on the front surface (viewing side) of an image display panel and can be used as components of an image display device. The optical laminate, which is a circular polarizer, can also be used as an anti-reflection polarizer that imparts anti-reflection function to an image display device. The image display device is not particularly limited, and examples thereof include organic electroluminescence (organic EL) display devices, inorganic electroluminescence (inorganic EL) display devices, liquid crystal display devices, electroluminescence display devices, and other image display devices. [Example]
[0143] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these. "%" and "parts" in the examples and comparative examples are "% by mass" and "parts by mass" unless otherwise specified.
[0144] [Preparation of single-sided protected polarizing plate] (Fabrication of polarizer) A polyvinyl alcohol film with a thickness of 20 μm, a degree of polymerization of 2400, and a degree of saponification of 99% or more was uniaxially stretched to a stretching ratio of 4.1 times on a heated roll, and while maintaining tension, it was immersed for 60 seconds at 28°C in a dye bath containing 0.05 parts by weight of iodine and 5 parts by weight of potassium iodide per 100 parts by weight of water.
[0145] The film was then immersed in boric acid aqueous solution 1, which contained 5.5 parts by weight of boric acid and 15 parts by weight of potassium iodide per 100 parts by weight of water, at 64°C for 110 seconds. The film was then immersed in boric acid aqueous solution 2, which contained 5.5 parts by weight of boric acid and 15 parts by weight of potassium iodide per 100 parts by weight of water, at 67°C for 30 seconds. The film was then washed with pure water at 10°C and dried to obtain a polarizer. The resulting polarizer had a thickness of 8 μm and a boron content of 4.3 wt%.
[0146] (Adjustment of water-based adhesive) A water-based adhesive was prepared by dissolving 3 parts by mass of carboxyl-modified polyvinyl alcohol (Kuraray Co., Ltd., product name "KL-318") in 100 parts by weight of water, and adding 1.5 parts by mass of a polyamide epoxy additive, which is a water-soluble epoxy resin (Taoka Chemical Co., Ltd., product name "Sumirez Resin (registered trademark) 650 (30)", an aqueous solution with a solids concentration of 30 wt%).
[0147] (Protective film A, protective film B and release film B) As the protective film A, a film (manufactured by Nippon Paper Industries Co., Ltd., product name "COP25ST-HC") was used, in which a hard coat layer having a thickness of 3 μm was formed on a stretched film made of a norbornene-based resin having a thickness of 25 μm. Protective film B was a 20 μm thick triacetyl cellulose film [Fujifilm The product used was a product manufactured by MURA Corporation under the trade name "ZRG20SL". A triacetyl cellulose film (manufactured by Fujifilm Corporation, "TD80UL") was used as release film B. The release film had a thickness of 80 μm and a moisture permeability of 502 g / m2·24 hr.
[0148] (Preparation of single-sided protective polarizing plate) The prepared polarizer was continuously transported, while Protective Film A was continuously unwound from its roll, and Release Film B was continuously unwound from its roll. An aqueous adhesive was injected between the polarizer and the corona-treated Protective Film A, and pure water was injected between the polarizer and Release Film B. The film was then passed through a lamination roll to obtain a laminated film consisting of Protective Film A / Aqueous Adhesive / Polarizer / Pure Water / Release Film B. The laminated film was transported and heated in a drying oven at 80°C for 300 seconds to dry the aqueous adhesive and volatilize and remove the pure water between the polarizer and Release Film B, yielding a single-sided protected polarizing plate with a release film. Release Film B was then peeled off from the single-sided protected polarizing plate with a release film to obtain a single-sided protected polarizing plate.
[0149] [Preparation of double-sided protected polarizing plate] A double-sided protected polarizing plate was obtained in the same manner as in the preparation of the above single-sided protected polarizing plate, except that protective film B was used instead of release film B to obtain a laminate film consisting of protective film A / water-based adhesive / polarizer / water-based adhesive / protective film B.
[0150] [Preparation of retardation laminate] (1st liquid crystal hardening layer) The first liquid crystal cured layer (first retardation layer) was a layer that provided a λ / 4 retardation and was composed of a layer of cured nematic liquid crystal compound, an alignment film, and a transparent substrate. The total thickness of the layer of cured nematic liquid crystal compound and the alignment layer was 2 μm.
[0151] (Preparation of second liquid crystal cured layer) As a composition for forming the alignment layer, 10.0 parts by mass of polyethylene glycol di(meth)acrylate (A-600, manufactured by Shin-Nakamura Chemical Co., Ltd.), 10.0 parts by mass of trimethylolpropane triacrylate (A-TMPT, manufactured by Shin-Nakamura Chemical Co., Ltd.), 10.0 parts by mass of 1,6-hexanediol di(meth)acrylate (A-HD-N, manufactured by Shin-Nakamura Chemical Co., Ltd.), and 1.50 parts by mass of Irgacure 907 (Irg-907, manufactured by BASF) as a photopolymerization initiator were dissolved in 70.0 parts by mass of methyl ethyl ketone solvent to prepare a coating liquid for forming the alignment layer.
[0152] A 20 μm thick long cyclic olefin resin (COP) film (manufactured by Zeon Corporation) was prepared as a substrate film, and the coating liquid for forming an alignment layer was applied to one side of the substrate film using a bar coater.
[0153] After the coating, the coating layer was heat treated at 80°C for 60 seconds, and then exposed to ultraviolet light (UVB) at 220 mJ / cm 2 The composition for forming the alignment layer was polymerized and cured by irradiation, forming an alignment layer having a thickness of 2.3 μm on the substrate film.
[0154] As a composition for forming the retardation layer, 20.0 parts by mass of a photopolymerizable nematic liquid crystal compound (RMM28B, manufactured by Merck) and 1.0 part by mass of Irgacure 907 (Irg-907, manufactured by BASF) as a photopolymerization initiator were dissolved in 80.0 parts by mass of propylene glycol monomethyl ether acetate solvent to prepare a coating liquid for forming the retardation layer.
[0155] The retardation layer forming coating liquid is applied onto the previously obtained alignment layer, and the coating layer is heated at 80°C for 60 seconds. After that, ultraviolet light (UVB) was applied at 220 mJ / cm 2 The retardation layer was polymerized and cured by irradiation to form a 0.7 μm thick retardation layer on the alignment layer. In this way, a 3 μm thick second liquid crystal cured layer (second retardation layer) consisting of the alignment layer and the retardation layer was obtained on the substrate film.
[0156] (Preparation of Retardation Laminate) The first liquid crystal layer and the second liquid crystal layer were bonded together with a UV-curable adhesive (1 μm thick) so that the liquid crystal layer surfaces (the surfaces opposite the substrate film) were the bonding surfaces. Next, the UV-curable adhesive was cured by irradiating it with UV light to produce a retardation laminate including two retardation layers, the first cured liquid crystal layer and the second cured liquid crystal layer. The thickness of the retardation laminate including the first cured liquid crystal layer, the UV-curable adhesive layer, and the second cured liquid crystal layer was 6 μm.
[0157] [Preparation of photoselective absorbing adhesive layer] (Preparation of acrylic resin (A-1)) A reaction vessel equipped with a condenser, nitrogen inlet, thermometer, and stirrer was charged with a mixture of 86.4 parts ethyl acetate, 61.9 parts butyl acrylate, and 1.9 parts 2-hydroxyethyl acrylate as the solvent. The air in the vessel was purged with nitrogen gas to remove oxygen, and the internal temperature was raised to 60°C. A solution of 0.4 parts azobisisobutyronitrile (polymerization initiator) in 10 parts ethyl acetate was then added in its entirety. The resulting mixture was held at 60°C for 1 hour, and then ethyl acetate was continuously added to the reaction vessel at a rate of 17.3 parts / hr while maintaining the internal temperature at 50-70°C. When the acrylic resin concentration reached 35%, the ethyl acetate addition was stopped. The reaction was maintained at this temperature for 12 hours. Finally, ethyl acetate was added to adjust the acrylic resin concentration to 20%, preparing an acrylic resin-ethyl acetate solution. The resulting acrylic resin had a weight-average molecular weight (Mw) of 600,000 (as measured by GPC) in terms of polystyrene, and an Mw / Mn ratio of 7.0. This was designated acrylic resin (A-1). The glass transition temperature measured by DSC was −52.9° C.
[0158] (Preparation of Pressure-Sensitive Adhesive Layer (1)) In an ethyl acetate solution of acrylic resin (A-1) (resin concentration: 20%), 0.5 parts of a crosslinker (Coronate L, solids content 75%: manufactured by Tosoh), 0.5 parts of a silane compound (KBM-403 manufactured by Shin-Etsu Chemical Co., Ltd.), and 5.4 parts of a compound represented by the following formula (aa2) (light-selective absorber) described as a light-selective absorbing compound (2) in Synthesis Example 2 described in paragraph
[0142] of JP 2019-007001 A were mixed, and 2-butanone was added to obtain a solids concentration of 14%, thereby obtaining a pressure-sensitive adhesive composition (1). The amount of the crosslinker (Coronate L) is expressed in parts by mass as the active ingredient. [ka]
[0159] The pressure-sensitive 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 thickness of the pressure-sensitive adhesive layer after drying would be 17 μm, and the applied film was dried at 100°C for 1 minute to prepare a pressure-sensitive adhesive layer. The resulting pressure-sensitive adhesive layer was designated pressure-sensitive adhesive layer (1). Table 1 shows the content of the light-selective absorber per unit area of the pressure-sensitive adhesive layer (1).
[0160] (Preparation of Pressure-Sensitive Adhesive Layer (2)) The adhesive layer (2) was prepared in the same manner as the adhesive layer (1), except that the amount of the light-selective absorber was 2.5 parts and the thickness of the adhesive layer after drying was 5 μm. Table 1 shows the content of the light-selective absorber per unit area of the adhesive layer (2).
[0161] (Preparation of Pressure-Sensitive Adhesive Layer (3)) The adhesive layer (3) was prepared in the same manner as the adhesive layer (1), except that the amount of the light-selective absorber was 3.7 parts and the thickness of the adhesive layer after drying was 5 μm. Table 1 shows the content of the light-selective absorber per unit area of the adhesive layer (3).
[0162] (Preparation of Pressure-Sensitive Adhesive Layer (4)) The pressure-sensitive adhesive layer (4) was produced in the same manner as the pressure-sensitive adhesive layer (1), except that the amount of the light-selective absorber was 2.5 parts and the thickness of the pressure-sensitive adhesive layer after drying was 17 μm. Table 1 shows the content of the light-selective absorber per unit area of the pressure-sensitive adhesive layer (4).
[0163] (Preparation of Pressure-Sensitive Adhesive Layer (5)) The adhesive layer (5) was produced in the same manner as the adhesive layer (1), except that the amount of the light-selective absorber was 3.7 parts so that the thickness of the adhesive layer after drying was 17 μm. Table 1 shows the content of the light-selective absorber per unit area of the adhesive layer (5).
[0164] (Preparation of Pressure-Sensitive Adhesive Layer (6)) The pressure-sensitive adhesive layer (6) was produced in the same manner as the pressure-sensitive adhesive layer (1), except that the amount of the light-selective absorber was 5.4 parts so that the thickness of the pressure-sensitive adhesive layer after drying was 17 μm. Table 1 shows the content of the light-selective absorber per unit area of the pressure-sensitive adhesive layer (6).
[0165] (Preparation of Pressure-Sensitive Adhesive Layer (7)) The adhesive layer (7) was produced in the same manner as the adhesive layer (1), except that the amount of the light-selective absorber was 2.9 parts so that the thickness of the adhesive layer after drying was 17 μm. Table 1 shows the content of the light-selective absorber per unit area of the adhesive layer (7).
[0166] [Preparation of second adhesive layer] An ethyl acetate solution of the acrylic resin (A-1) (resin concentration: 20%) was mixed with 0.5 parts of a crosslinker (Coronate L, solids content 75%: manufactured by Tosoh) and 0.5 parts of a silane compound (KBM-403 manufactured by Shin-Etsu Chemical Co., Ltd.), and 2-butanone was added to adjust the solids content to 14%, to obtain a pressure-sensitive adhesive composition. The amount of the crosslinker (Coronate L) is expressed in parts by mass as the active ingredient.
[0167] The adhesive composition was applied to the release-treated surface of the separator used to prepare the photoselectively absorbing adhesive layer using an applicator so that the thickness of the adhesive layer after drying would be 15 μm or 25 μm, and the adhesive composition was dried at 100°C for 1 minute to prepare a second adhesive layer.
[0168] [Preparation of optical laminate] (Reference example 1) A pressure-sensitive adhesive layer (1) was attached to the protective film B side of the prepared double-sided protected polarizing plate, and the separator was peeled off. The surface of the pressure-sensitive adhesive layer (1) from which the separator was peeled off was attached to the first liquid crystal cured layer side of the prepared retardation laminate, and the substrate film of the second liquid crystal cured layer was peeled off. A second pressure-sensitive adhesive layer with a separator having a thickness shown in Table 1 was attached to the surface from which the substrate film was peeled off.
[0169] Example 1 The pressure-sensitive adhesive layer (2) was attached to the polarizer side of the prepared single-sided protected polarizing plate, and the separator was peeled off. The surface of the pressure-sensitive adhesive layer (2) from which the separator had been peeled was attached to the first liquid crystal cured layer side of the prepared retardation laminate, and the base film of the second liquid crystal cured layer was peeled off. A second pressure-sensitive adhesive layer with a separator having a thickness shown in Table 1 was attached to the surface from which the base film had been peeled off. The optical laminate of Example 1 had a configuration as shown in FIG. 2.
[0170] (Examples 2 and 3, and Comparative Examples 1 and 2) The optical laminates of Examples 2 and 3 and Comparative Examples 1 and 2 were each produced by the same method as for the optical laminate of Example 1, using a pressure-sensitive adhesive layer shown in Table 1 instead of the pressure-sensitive adhesive layer (2) of Example 1, and using a separator-attached second pressure-sensitive adhesive layer having a thickness shown in Table 1. The optical laminates of Examples 2 and 3 and Comparative Examples 1 and 2 had a configuration as shown in FIG.
[0171] Example 4 A pressure-sensitive adhesive layer (4) was attached to the polarizer side of the produced single-sided polarizing plate, and the separator was peeled off to obtain an optical laminate of Example 4. The optical laminate of Example 4 had a structure as shown in FIG.
[0172] (Example 5 and Comparative Example 3) The optical laminates of Example 5 and Comparative Example 3 were each produced by the same method as for the optical laminate of Example 4, using a pressure-sensitive adhesive layer shown in Table 1 instead of the pressure-sensitive adhesive layer (4) of Example 4, and using a separator-attached second pressure-sensitive adhesive layer having the thickness shown in Table 1. The optical laminates of Example 5 and Comparative Example 3 had the configuration shown in FIG.
[0173] [Measurement of absorbance of adhesive layer] The pressure-sensitive adhesive layers (1) to (7) were each attached to glass, and the separator was peeled off. A cycloolefin polymer (COP) film (ZF-14, manufactured by Zeon Corporation) was then attached to the pressure-sensitive adhesive layer to prepare a laminate for pressure-sensitive adhesive layer evaluation. The laminate for pressure-sensitive adhesive layer evaluation was set in a UV-2450 spectrophotometer (manufactured by Shimadzu Corporation), and the absorbance was measured in a wavelength range of 300 to 800 nm in 1 nm steps using the double beam method. The absorbance at a wavelength of 410 nm of the prepared pressure-sensitive adhesive layer is shown in Table 1. The absorbance of both the glass and the COP film at a wavelength of 410 nm was zero.
[0174] [Measurement of weight average molecular weight (Mw)] The weight-average molecular weight (Mw) of the acrylic resin (A-1) was determined as the polystyrene-equivalent number-average molecular weight (Mn) by size exclusion chromatography (SEC) using tetrahydrofuran as the mobile phase. The (meth)acrylic polymer to be measured was dissolved in tetrahydrofuran at a concentration of approximately 0.05% by mass, and 10 μL was injected into the SEC. The mobile phase was run at a flow rate of 1.0 mL / min. A PLgel MIXED-B (manufactured by Polymer Laboratories) was used as the column. A UV-VIS detector (trade name: Agilent GPC) was used as the detector.
[0175] [Boron content measurement] 0.2 g of polarizer was dissolved in 200 g of 1.9 wt% mannitol aqueous solution. The resulting solution was titrated with 1 mol / L NaOH aqueous solution, and the boron content of the polarizer was calculated by comparing the amount of NaOH solution required for neutralization with the calibration curve.
[0176] [Moisture and heat resistance test and color fading observation] The separators of the optical laminates obtained in Reference Example 1, Examples 1 to 5, and Comparative Examples 1 to 3 were peeled off, and the laminates were attached to alkali-free glass plates, and then left to stand for 500 hours in an environment of a temperature of 65°C and a humidity of 90% RH. Thereafter, a polarizing plate was attached to the alkali-free glass surface opposite the optical laminates tested, in a crossed Nicol relationship, and the laminates were observed under an optical microscope, and the observed images were saved. Optical microscope A "VHX-500" manufactured by Keyence Corporation was used. Fig. 3 shows an example of an image observed with an optical microscope. In Fig. 3, when observing along the straight line indicated by the arrow (the straight line extending perpendicularly from the end 50) from the end 50 of the optical laminate inward, it can be seen that there are a decolorized region 51 and a region where decolorization has not occurred (non-decolorized region) 52.
[0177] [Measurement of color loss using image processing] The images observed under the microscope were converted to black and white in 256 gradations (0-255) using the image analysis software "ImageJ (free software)." The conversion to black and white in 256 gradations (0-255) was performed by averaging the RGB values. Figure 4 shows an example of the converted data. The midpoint (the middle of the decolorization gradation) between the decolorized region 51 and the non-decolorized region 52 in the gradation profile in the direction perpendicular to the edge 50 of the optical laminate (arrow in Figure 3) was defined as the decolorized edge of the optical laminate (Figure 4), and the distance (μm) from the edge 50 of the optical laminate to the decolorized edge was measured as the decolorization distance. The decolorization distance of the optical laminate is shown in Table 1. The smaller the decolorization distance, the narrower the decolorization range and the better the humidity and heat resistance.
[0178] [Table 1] [Explanation of symbols]
[0179] 10 polarizer, 11 protective film, 20 light-selective absorptive pressure-sensitive adhesive layer, 30 first retardation layer, 31 second retardation layer, 32 second pressure-sensitive adhesive layer, 33 adhesive layer, 50 edge of optical laminate, 51 color-bleached region, 52 non-color-bleached region, 100, 200 optical laminate, 300 retardation laminate.
Claims
1. An optical laminate having a polarizer and a light-selective absorbing pressure-sensitive adhesive layer laminated in contact with the polarizer, the polarizer has iodine adsorbed and oriented, and a boron content of 5.0 mass% or less; The optical laminate, wherein the photoselective absorbing pressure-sensitive adhesive layer is formed from a pressure-sensitive adhesive composition containing a photoselective absorber, and has an absorbance at a wavelength of 410 nm of 0.1 or more and 1.6 or less.
2. The optical laminate according to claim 1 , further comprising a protective film laminated on the polarizer on the side opposite to the light-selective absorbing pressure-sensitive adhesive layer side.
3. The light-selective absorbing pressure-sensitive adhesive layer has a content of the light-selective absorbing agent per unit area of 0.01 g / m 2 5g / m or more 2 The optical laminate according to claim 1 or 2, wherein:
4. The optical laminate according to any one of claims 1 to 3, wherein the pressure-sensitive adhesive composition contains 0.1 parts by mass or more and 10 parts by mass or less of the light selective absorber per 100 parts by mass of the total resin component.
5. 5. The optical laminate according to claim 1, wherein the light-selective absorptive pressure-sensitive adhesive layer has a thickness of 0.1 μm or more and 150 μm or less.
6. 6. The optical laminate according to claim 1, wherein the selective light absorber is an organic selective light absorber having a molecular weight of 100 or more and 3,000 or less.
7. The optical laminate according to any one of claims 1 to 6, further comprising a λ / 4 retardation layer laminated on the side of the light-selective absorptive pressure-sensitive adhesive layer opposite to the polarizer.
8. The optical laminate according to any one of claims 1 to 7, which is an anti-reflection polarizing plate.
9. An image display device comprising: an image display panel; and the optical laminate according to claim 8 arranged in front of the image display panel.
10. The image display device according to claim 9 , wherein the image display panel is an organic EL display panel.
Citation Information
Patent Citations
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