Adhesive composition

Abstract

To provide an adhesive layer that has a sufficient ultraviolet absorbing ability even when reduced in thickness, reduces the occurrence of bleedout, and reduces the absorption of visible light around at a wavelength of 420 nm, and an adhesive composition for forming the adhesive layer.SOLUTION: An adhesive composition contains a resin (A), a light selection absorption compound (B) that shows a maximum absorption at a wavelength of 360 nm or more and satisfies following formulae (1) and (2), and at least one selected from a monomer (C-1) that has a polymerizable group in the molecule and shows a maximum absorption at a wavelength of 300 nm or more and less than 360 nm and a resin (C-2) that shows a maximum absorption at a wavelength of 300 nm or more and less than 360 nm. ε(380)≥25 (1). ε(380) / ε(420)≥20 (2). [In the formulae (1) and (2), ε(380) denotes a gram extinction coefficient of the light selection absorption compound (B) at a wavelength of 380 nm and ε(420) denotes a gram extinction coefficient of the light selection absorption compound (B) at a wavelength of 420 nm. The unit of the gram extinction coefficient is L / (g cm)].SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a pressure-sensitive adhesive composition, a pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition, and an optical laminate in which the pressure-sensitive adhesive layer is laminated. [Background technology]

[0002] Display devices (FPD: Flat Panel Displays) such as organic electroluminescence displays (organic EL display devices) and liquid crystal display devices use a variety of components, including display elements such as organic EL elements and liquid crystal cells, and optical films such as polarizing plates. Among these components, the liquid crystal compounds used in organic EL elements and liquid crystal cells often have relatively poor weather resistance, making deterioration due to ultraviolet (UV) rays a common problem. To solve this problem, Patent Document 1 describes an ultraviolet absorbing (shielding) pressure-sensitive adhesive composition containing an acrylic resin and a triazine-based ultraviolet absorber, and also describes a 15 μm-thick pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2008-248131 Summary of the Invention [Problem to be solved by the invention]

[0004] In recent years, there has been a demand for organic electroluminescence (EL) display devices and liquid crystal display devices to be significantly thinner, and there has also been a demand for significantly thinner components used in these devices. Therefore, there is a demand for thinner ultraviolet-absorbing (shielding) pressure-sensitive adhesive layers themselves. However, simply thinning the ultraviolet-absorbing (shielding) pressure-sensitive adhesive layer (to less than 12 μm, for example) reduces the UV absorption performance of the pressure-sensitive adhesive layer. On the other hand, increasing the amount of UV absorber added in an attempt to thin the pressure-sensitive adhesive layer while maintaining UV absorption performance can cause problems such as bleed-out of the UV absorber and coloration due to absorption of visible light with wavelengths of 420 nm or more. [Means for solving the problem]

[0005] The present invention includes the following inventions. [1] Resin (A), A light-selective absorbing compound (B) that exhibits a maximum absorption at a wavelength of 360 nm or more and satisfies the following formulas (1) and (2): At least one selected from a monomer (C-1) having a polymerizable group in the molecule and exhibiting a maximum absorption at a wavelength of 300 nm or more and less than 360 nm and a resin (C-2) exhibiting a maximum absorption at a wavelength of 300 nm or more and less than 360 nm A pressure-sensitive adhesive composition comprising: ε(380)≧25 (1) ε(380) / ε(420)≧20 (2) [In formulas (1) and (2), ε(380) represents the gram absorption coefficient of the light-selective absorbing compound (B) at a wavelength of 380 nm, and ε(420) represents the gram absorption coefficient of the light-selective absorbing compound (B) at a wavelength of 420 nm. The unit of the gram absorption coefficient is L / (g cm)] [2] The pressure-sensitive adhesive composition according to [1], further comprising an initiator (D). [3] The pressure-sensitive adhesive composition according to [2], wherein the initiator (D) is a radical generator. [4] The pressure-sensitive adhesive composition according to [2] or [3], wherein the initiator (D) is a photoradical generator. [5] The pressure-sensitive adhesive composition according to any one of [2] to [4], wherein the initiator (D) is an oxime ester-based photoradical generator. [6] The pressure-sensitive adhesive composition according to any one of [1] to [5], further comprising a radically curable component (E). [7] The pressure-sensitive adhesive composition according to [6], wherein the radically curable component (E) contains a (meth)acrylate compound. [8] The pressure-sensitive adhesive composition according to [6] or [7], wherein the radically curable component (E) contains a polyfunctional (meth)acrylate compound. [9] The pressure-sensitive adhesive composition according to any one of [1] to [8], further comprising a crosslinking agent (F).

[10] The pressure-sensitive adhesive composition according to [9], wherein the crosslinking agent (F) is an isocyanate-based crosslinking agent.

[11] The pressure-sensitive adhesive composition according to any one of [1] to

[10] , wherein the resin (A) has a glass transition temperature of 40° C. or lower.

[12] The pressure-sensitive adhesive composition according to

[11] , wherein the resin (A) having a glass transition temperature of 40°C or lower is a (meth)acrylic resin.

[13] A pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition according to any one of [1] to

[12] .

[14] The pressure-sensitive adhesive layer according to

[13] , wherein the pressure-sensitive adhesive layer satisfies the following formula (3): A(380)≧0.6 (3) [In formula (3), A(380) represents absorbance at a wavelength of 380 nm.]

[15] The pressure-sensitive adhesive layer according to

[14] , further satisfying the following formula (4): A(380) / A(420)≧5 (4) [In formula (4), A(380) represents the absorbance at a wavelength of 380 nm, and A(420) represents the absorbance at a wavelength of 420 nm.]

[16] The pressure-sensitive adhesive layer according to any one of

[13] to

[15] , wherein the thickness of the pressure-sensitive adhesive layer is 10 μm or less.

[17] An optical film with a pressure-sensitive adhesive layer, comprising the pressure-sensitive adhesive layer according to any one of

[13] to

[16] and an optical film laminated on at least one surface of the pressure-sensitive adhesive layer.

[18] The optical film with a pressure-sensitive adhesive layer according to

[17] , wherein the optical film is a polarizing plate.

[19] An image display device comprising the pressure-sensitive adhesive layer-attached optical film according to

[17] or

[18] . [Effects of the Invention]

[0006] The present invention provides a pressure-sensitive adhesive layer that has sufficient ultraviolet absorption performance even when the film thickness is thin (for example, less than 12 μm), and that exhibits little bleed-out and little absorption of visible light with a wavelength of around 420 nm, and a pressure-sensitive adhesive composition for forming the pressure-sensitive adhesive layer. [Brief explanation of the drawings]

[0007] [Figure 1] An example of the layer structure of the laminate of the present invention in which a release film is provided on the pressure-sensitive adhesive layer is shown below. [Figure 2] An example of the layer structure of the pressure-sensitive adhesive layer-attached optical film of the present invention is shown below. [Figure 3] An example of the layer structure of the pressure-sensitive adhesive layer-attached optical film of the present invention is shown below. [Figure 4] An example of the layer structure of the optical laminate of the present invention is shown below. [Figure 5] An example of the layer structure of the optical laminate of the present invention is shown below. DETAILED DESCRIPTION OF THE INVENTION

[0008] <Adhesive composition> The pressure-sensitive adhesive composition of the present invention contains the following (Z-1) to (Z-3). (Z-1): Resin (A) (Z-2): A light-selective absorbing compound (B) that exhibits an absorption maximum at a wavelength of 360 nm or more and satisfies the following formulas (1) and (2) (hereinafter, may be referred to as light-selective absorbing compound (B)). (Z-3): At least one selected from a monomer (C-1) (hereinafter sometimes referred to as a light-selective absorbing compound (C-1)) having a polymerizable group in the molecule and exhibiting a maximum absorption in the wavelength range of 300 nm or more and less than 360 nm, and a resin (C-2) (hereinafter sometimes referred to as a light-selective absorbing resin (C-2)) exhibiting a maximum absorption in the wavelength range of 300 nm or more and less than 360 nm.

[0009] <Resin (A)> The resin (A) of the present invention is not particularly limited as long as it is a resin that can be used in a pressure-sensitive adhesive composition. The resin (A) preferably has a glass transition temperature (Tg) of 40°C or lower. The glass transition temperature (Tg) of the resin (A) is more preferably 20°C or lower, even more preferably 10°C or lower, and particularly preferably 0°C or lower. The glass transition temperature of the resin (A) is usually -80°C or higher, preferably -70°C or higher, more preferably -60°C or higher, even more preferably -55°C or higher, and particularly preferably -50°C or higher. A glass transition temperature of the resin (A) of 40°C or lower is advantageous in improving the adhesion of a pressure-sensitive adhesive layer formed from a pressure-sensitive adhesive composition containing the resin (A) to an adherend. A glass transition temperature of the resin (A) of -80°C or higher is advantageous in improving the durability of a pressure-sensitive adhesive layer formed from a pressure-sensitive adhesive composition containing the resin (A). The glass transition temperature can be measured by a differential scanning calorimeter (DSC). Furthermore, it is preferable that the resin (A) does not exhibit a maximum absorption in the wavelength range of 300 nm to 780 nm.

[0010] Examples of the resin (A) include (meth)acrylic resins, silicone resins, rubber resins, and urethane resins, with (meth)acrylic resins being preferred.

[0011] The (meth)acrylic resin is preferably a polymer containing structural units derived from (meth)acrylic acid esters as the main component (preferably containing 50% by mass or more). The structural units derived from (meth)acrylic acid esters may contain structural units derived from one or more monomers other than (meth)acrylic acid esters (for example, structural units derived from monomers having polar functional groups). In this specification, (meth)acrylic acid means either acrylic acid or methacrylic acid, and the "(meth)" in (meth)acrylate and the like has the same meaning.

[0012] Examples of the (meth)acrylic acid ester include (meth)acrylic acid esters represented by the following formula (a). [ka] [In formula (a), R 1A represents a hydrogen atom or a methyl group, and R 2A represents an alkyl group having 1 to 14 carbon atoms or an aromatic hydrocarbon group having 6 to 20 carbon atoms, and a hydrogen atom of the alkyl group or aromatic hydrocarbon group may be substituted with an alkoxy group having 1 to 10 carbon atoms.

[0013] In formula (a), R 2A is preferably an alkyl group having 1 to 14 carbon atoms, and more preferably an alkyl group having 1 to 8 carbon atoms.

[0014] The (meth)acrylic acid ester represented by formula (a) includes: (Meth)acrylates 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. Linear alkyl esters of acrylic acid; 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 and benzyl (meth)acrylate; etc. Examples of the substituted (meth)acrylic acid ester include 2-methoxyethyl (meth)acrylate, ethoxymethyl (meth)acrylate, phenoxyethyl (meth)acrylate, and 2-(2-phenoxyethoxy)ethyl (meth)acrylate. Examples of the (meth)acrylic acid ester include phenoxydiethylene glycol (meth)acrylate and phenoxypoly(ethylene glycol) (meth)acrylate.

[0015] These (meth)acrylic acid esters may be used alone or in combination of two or more different types.

[0016] The resin (A) of the present invention preferably contains structural units derived from (meth)acrylic acid alkyl ester (a1) of which the homopolymer has a glass transition temperature (Tg) of less than 0°C, and structural units derived from (meth)acrylic acid alkyl ester (a2) of which the homopolymer has a Tg of 0°C or higher, among (meth)acrylic acid alkyl esters. This is advantageous in terms of improving the high-temperature durability of the pressure-sensitive adhesive layer. For the Tg of the (meth)acrylic acid alkyl ester homopolymer, literature values such as those in POLYMER HANDBOOK (Wiley-Interscience) can be used.

[0017] Specific examples of the (meth)acrylic acid alkyl ester (a1) include (meth)acrylic acid alkyl esters in which the alkyl group has about 2 to 12 carbon atoms, 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.

[0018] The (meth)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 conformability and reworkability when laminated on an optical film.

[0019] The (meth)acrylic acid alkyl ester (a2) is a (meth)acrylic acid alkyl ester other than the (meth)acrylic acid alkyl ester (a1). Specific examples of the (meth)acrylic acid alkyl ester (a2) include methyl acrylate, cyclohexyl acrylate, isobornyl acrylate, stearyl acrylate, t-butyl acrylate, etc.

[0020] The (meth)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 (meth)acrylic acid alkyl ester (a2) preferably contains methyl acrylate, cyclohexyl acrylate, isobornyl acrylate, or the like, and more preferably contains methyl acrylate.

[0021] The structural units derived from the (meth)acrylic acid ester represented by formula (a) 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.

[0022] 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-hydroxyhexyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 3-hydroxybutyl (meth)acrylate, (meth)acrylate, p) 3-hydroxypentyl 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, 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-hydroxydecyl (meth)acrylate, 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-hydroxydecyl (meth)acrylate, 9-hydroxyundecyl (meth)acrylate, 9-hydroxydodecyl (meth)acrylate,9-Hydroxytridecyl (meth)acrylate, 10-hydroxydecyl (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, 11-hydroxytetradecyl (meth)acrylate, 11-hydroxypentadecyl (meth)acrylate, ) Monomers having a hydroxy group, such as 12-hydroxydodecyl 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 and a monomer having a carboxyl group are preferred, and it is more preferred to include both a monomer having a hydroxy group and a monomer having a carboxyl group.

[0023] Preferred examples of the hydroxyl group-containing monomer include 2-hydroxyethyl acrylate, 3-hydroxypropyl acrylate, 4-hydroxybutyl acrylate, 5-hydroxypentyl acrylate, and 6-hydroxyhexyl acrylate. In particular, good durability can be achieved 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.

[0024] 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 is substantially free of structural units derived from monomers having an amino group, where "substantially free" means that the amount of such structural units is 0.1 part by mass or less per 100 parts by mass of all structural units constituting the (meth)acrylic resin.

[0025] The content of the structural units derived from the monomers having polar functional groups 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.

[0026] Examples of structural units derived from monomers other than (meth)acrylic acid esters include structural units derived from monomers having an aromatic group. Examples of monomers having an aromatic group include (meth)acrylic acid esters having one (meth)acryloyl group and one or more aromatic rings (e.g., benzene ring, naphthalene ring, etc.) in the molecule, such as (meth)acrylic acid esters having a phenyl group, a phenoxyethyl group, or a benzyl group. The content of the structural units derived from the monomers having an aromatic group is preferably 20 parts by mass or less, more preferably 4 to 20 parts by mass, and even more preferably 4 to 16 parts by mass, relative to 100 parts by mass of all structural units of the (meth)acrylic resin.

[0027] 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.

[0028] 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.

[0029] 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.

[0030] 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.

[0031] 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, 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-methylpropoxymethyl)(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 Examples of such acrylamide include N-(2-methylethoxy)ethyl (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, and N-(2-(1,1-dimethylethoxy)ethyl) (meth)acrylamide. Among these, N-(methoxymethyl)acrylamide, N-(ethoxymethyl)acrylamide, N-(propoxymethyl)acrylamide, N-(butoxymethyl)acrylamide, and N-(2-methylpropoxymethyl)acrylamide are preferred.

[0032] The weight-average molecular weight (Mw) of the (meth)acrylic resin is preferably 500,000 to 2,500,000. 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.

[0033] When the (meth)acrylic acid resin 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.

[0034] (Meth)acrylic resins 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 the mixture for approximately 3 to 15 hours at a temperature of 40 to 90°C, preferably 50 to 80°C. To control the reaction, the monomers and the thermal polymerization initiator may be added continuously or intermittently during polymerization. The monomers and the thermal polymerization initiator may be added to the organic solvent. Examples of the organic solvent 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. Known thermal polymerization initiators can be used as the thermal polymerization initiator. Alternatively, a photopolymerization initiator may be used instead of the thermal polymerization initiator, and polymerization using ultraviolet light or the like may be performed.

[0035] The content of the resin (A) is usually 50% by mass to 99.9% by mass, preferably 60% by mass to 95% by mass, and more preferably 70% by mass to 90% by mass, based on 100% by mass of the solid content of the adhesive composition.

[0036] <Light-selective absorption compound (B)> The light-selective absorbing compound (B) exhibits an absorption maximum at a wavelength of 360 nm or more. The light-selective absorbing compound (B) preferably exhibits an absorption maximum between a wavelength of 360 nm or more and a wavelength of 420 nm or less, and more preferably between a wavelength of 370 nm or more and a wavelength of 410 nm or less. By exhibiting an absorption maximum at a wavelength of 360 nm or more, even a small amount added can efficiently absorb light having a wavelength of around 380 nm.

[0037] The selective light absorption compound (B) satisfies the following formulas (1) and (2). ε(380)≧ 25 (1) [In formula (1), ε(380) represents the gram absorption coefficient of the light-selective absorption compound (B) at a wavelength of 380 nm. The unit of the gram absorption coefficient is L / (g cm)]. ε(380) / ε(420)≧ 20 (2) [In formula (2), ε(380) represents the gram absorption coefficient of the light-selective absorbing compound (B) at a wavelength of 380 nm, and ε(420) represents the gram absorption coefficient of the light-selective absorbing compound (B) at a wavelength of 420 nm. The unit of gram extinction coefficient is L / (g·cm).

[0038] The ε(380) value is preferably 30 L / (g·cm) or more, more preferably 35 L / (g·cm) or more, even more preferably 50 L / (g·cm) or more, even more preferably 100 L / (g·cm) or more, and is usually 10,000 L / (g·cm) or less. Compounds with a higher ε(380) value are more likely to absorb light with a wavelength of 380 nm and more likely to exhibit UV degradation inhibition properties. The light-selective absorption compound (B) preferably has a value of ε(380) / ε(420) of 25 or more, more preferably 35 or more, even more preferably 50 or more, and particularly preferably 100 or more. A pressure-sensitive adhesive layer formed from a pressure-sensitive adhesive composition containing a compound having a large value of ε(380) / ε(420) absorbs ultraviolet light in the vicinity of 380 nm without impairing the color expression of a display device. In addition, photodegradation of a display device such as a laminated optical film (retardation film) or an organic EL element can be suppressed.

[0039] The selective light absorption compound (B) preferably does not contain a merocyanine structure in the molecule. In the present invention, the merocyanine structure refers to a partial structure represented by N-C=C=C. However, the merocyanine structure in the present invention does not include an aromatic fused ring (e.g., an indole ring, a benzotriazole ring, a benzimidazole ring, an isoindole ring, a quinoline ring, etc.) in which all of the partial structures represented by N-C=C=C are constituent elements of the ring. In other words, the light-selective absorption compound (B) may contain, in its molecule, an aromatic fused ring in which all of the partial structures represented by N-C=C=C are constituent elements of the ring.

[0040] As the light selective absorption compound (B), commercially available products may be used, such as FUV-002B (manufactured by Fujifilm Corporation).

[0041] The content of the light-selective absorption compound (B) is usually 0.01 to 50 parts by mass, preferably 0.1 to 20 parts by mass, more preferably 0.5 to 10 parts by mass, and particularly preferably 1.0 to 5 parts by mass, relative to 100 parts by mass of the resin (A).

[0042] <Light-selective absorption compound (C-1)> The selective light absorption compound (C-1) is a monomer that has a polymerizable group in the molecule and exhibits maximum absorption in the wavelength range of 300 nm or more and less than 360 nm. The light-selective absorption compound (C-1) preferably exhibits an absorption maximum at a wavelength of 320 nm or more and 355 nm or less, and more preferably exhibits an absorption maximum at a wavelength of 330 nm or more and 350 nm or less.

[0043] Examples of the polymerizable group contained in the light-selective absorbing compound (C-1) include cationic polymerizable groups such as an epoxy group, an oxetanyl group, an oxazolino group, an aziridino group, and a vinyl ether group; and radically polymerizable groups such as an ethylenically unsaturated group. The polymerizable group contained in the light-selective absorbing compound (C-1) is preferably a radically polymerizable group such as an ethylenically unsaturated group. Specific examples of the ethylenically unsaturated group include a vinyl group, an α-methylvinyl group, an acryloyl group, a methacryloyl group, an allyl group, a styryl group, a (meth)acrylamide group, a vinyl sulfone group, and a (meth)acryloyloxy group.

[0044] Examples of the light-selective absorption compound (C-1) include a compound having a polymerizable group and a benzotriazole skeleton in the molecule, a compound having a polymerizable group and a benzimidazole skeleton in the molecule, a compound having a polymerizable group and a triazine skeleton in the molecule, a compound having a polymerizable group and a benzophenone skeleton in the molecule, and a compound having a polymerizable group and a non-polymerizable cyanoacrylate skeleton in the molecule.

[0045] Examples of the light-selective absorption compound (C-1) include the compounds shown below. 2-[2-(2,4-dihydroxyphenyl)-2H-benzotriazol-5-yloxy]ethyl methacrylate, 2-[2-(4-ethoxy-2-hydroxyphenyl)-2H-benzotriazol-5-yloxy]ethyl methacrylate, 2-[2-(4-butoxy-2-hydroxyphenyl)-2H-benzotriazol-5-yloxy]ethyl methacrylate, 2-[2-(4-benzoyloxy-2-hydroxyphenyl)-2H-benzotriazol-5-yloxy]ethyl methacrylate, 4-[2-(2,4-dihydroxyphenyl)-2H-benzotriazol-5-yloxy]butyl methacrylate, 4-[2-(4-ethoxy-2-hydroxyphenyl)-2H-benzotriazol-5-yloxy]butyl methacrylate, 4-[2-(4-butoxy-2-hydroxyphenyl)-2H-benzotriazol-5-yloxy]butyl methacrylate, 4-[2-(2-hydroxy-4-octyloxyphenyl)-2H-benzotriazol-5-yloxy]butyl methacrylate, 4-[2-(4-benzoyloxy-2-hydroxyphenyl)-2H-benzotriazol-5-yloxy]butyl methacrylate, 2-[2-(2-hydroxy-4-octyloxyphenyl)-2H-benzotriazol-5-yloxy]ethyl methacrylate, 2-[2-(4-octyloxy-2-hydroxyphenyl)-2H-benzotriazol-5-yloxy]ethyl methacrylate, 2-[2-(4-methoxy-5-tert-butyl-2-hydroxyphenyl)-2H-benzotriazol-5-yloxy]ethyl methacrylate, 2-[2-(4-methoxy-3-tert-butyl-2-hydroxyphenyl)-2H-benzotriazol-5-yloxy]ethyl methacrylate, 2-2-(4-methoxy-3-methyl-2-hydroxyphenyl)-2H-benzotriazol-5-yloxy]ethyl methacrylate, 2-[2-hydroxy-5-(methacryloyloxyethyl)phenyl]-2H-benzotriazole, 2-[2-hydroxy-5-(methacryloyl)phenyl]-2H-benzotriazole, 2-[2-hydroxy-5-(methacryloyloxypropyl)phenyl]-5-chloro-2H-benzotriazole, 2-[2-hydroxy-5-(methacryloyloxypropyl)phenyl]-2H-benzotriazole, N-[3-benzotriazol-2-yl-2-hydroxy-5-(1,1,3,3-tetramethylbutyl)-benzoyl]-2-methylmethacrylamide,

[0046] 2-[2-(2,4-dihydroxyphenyl)-2H-benzotriazol-5-yloxy]ethyl acrylate, 2-[2-(4-ethoxy-2-hydroxyphenyl)-2H-benzotriazol-5-yloxy]ethyl acrylate, 2-[2-(4-butoxy-2-hydroxyphenyl)-2H-benzotriazol-5-yloxy]ethyl acrylate, 2-[2-(4-benzoyloxy-2-hydroxyphenyl)-2H-benzotriazol-5-yloxy]ethyl acrylate, 4-[2-(2,4-dihydroxyphenyl)-2H-benzotriazol-5-yloxy]butyl acrylate, 4-[2-(4-ethoxy-2-hydroxyphenyl)-2H-benzotriazol-5-yloxy]butyl acrylate, 4-[2-(4-butoxy-2-hydroxyphenyl)-2H-benzotriazol-5-yloxy]butyl acrylate, 4-[2-(2-hydroxy-4-octyloxyphenyl)-2H-benzotriazol-5-yloxy]butyl acrylate, 2-[2-(2-hydroxy-4-octyloxyphenyl)-2H-benzotriazol-5-yloxy]ethyl acrylate, 4-[2-(4-benzoyloxy-2-hydroxyphenyl)-2H-benzotriazol-5-yloxy]butyl acrylate, 2-[2-(4-octyloxy-2-hydroxyphenyl)-2H-benzotriazol-5-yloxy]ethyl acrylate, 2-[2-(4-methoxy-5-tert-butyl-2-hydroxyphenyl)-2H-benzotriazol-5-yloxy]ethyl acrylate, 2-[2-(4-methoxy-3-tert-butyl-2-hydroxyphenyl)-2H-benzotriazol-5-yloxy]ethyl acrylate, 2-[2-(4-methoxy-3-methyl-2-hydroxyphenyl)-2H-benzotriazol-5-yloxy]ethyl acrylate, 2-[2-hydroxy-5-(acryloyloxyethyl)phenyl]-2H-benzotriazole, 2-[2-hydroxy-5-(acryloyl)phenyl]-2H-benzotriazole, 2-[2-hydroxy-5-(methacryloyloxypropyl)phenyl]-5-chloro-2H-benzotriazole, 2-[2-hydroxy-5-(methacryloyloxypropyl)phenyl]-2H-benzotriazole, N-[3-benzotriazol-2-yl-2-hydroxy-5-(1,1,3,3-tetramethylbutyl)-benzoyl]-2-methylacrylamide, 2-hydroxy-4-acryloyloxybenzophenone, 2-hydroxy-4-methacryloyloxybenzophenone, 2-hydroxy-4-(2-acryloyloxy)ethoxybenzophenone, 2-hydroxy-4-(2-methacryloyloxy)ethoxybenzophenone, 2-hydroxy-4-(2-methyl-2-acryloyloxy)ethoxybenzophenone,

[0047] 2,4-diphenyl-6-[2-hydroxy-4-(2-methacryloyloxyethoxy)phenyl]-s-triazine, 2,4-diphenyl-6-[2-hydroxy-4-(2-acryloyloxyethoxy)phenyl]-s-triazine, 2,4-bis(2-methylphenyl)-6-[2-hydroxy-4-(3-methacryloyloxy-2-hydroxypropyloxy)phenyl]-s-triazine, 2,4-bis(2-methylphenyl)-6-[2-hydroxy-4-(3-acryloyloxy-2-hydroxypropyloxy)phenyl]-s-triazine, 2,4-bis(2-methoxyphenyl)-6-[2-hydroxy-4-(2-acryloyloxyethoxy)phenyl]-s-triazine, 2,4-bis(2-methoxyphenyl)-6-[2-hydroxy-4-(2-methacryloyloxyethoxy)phenyl]-s-triazine, 2,4-bis(2-ethylphenyl)-6-[2-hydroxy-4-(2-methacryloyloxyethoxy)phenyl]-s-triazine, 2,4-bis(2-ethylphenyl)-6-[2-hydroxy-4-(2-acryloyloxyethoxy)phenyl]-s-triazine, 2,4-bis(2-ethoxyphenyl)-6-[2-hydroxy-4-(2-methacryloyloxyethoxy)phenyl]-s-triazine, 2,4-bis(2-ethoxyphenyl)-6-[2-hydroxy-4-(2-acryloyloxyethoxy)phenyl]-s-triazine and the like.

[0048] The light selective absorption compound (C-1) may also be the compound shown below. [ka]

[0049] In addition, commercially available products may be used as the light-selective absorption compound (C-1), and specific examples include "RUVA-93" (Otsuka Chemical Co., Ltd.), "CHISORB 5687" (Double Bond Chemical Co.), and "Tinuvin R 796" (BASF).

[0050] The light-selective absorption compound (C-1) is preferably a compound having a polymerizable group and a benzotriazole skeleton in the molecule, a compound having a polymerizable group and a triazine skeleton in the molecule, or a compound having a polymerizable group and a benzophenone skeleton in the molecule.

[0051] <Light-selective absorption resin (C-2)> The light-selective absorption resin (C-2) is a resin that exhibits a maximum absorption at a wavelength of 300 nm or more and less than 360 nm. The light-selective absorption resin (C-2) preferably exhibits a maximum absorption at a wavelength of 320 nm or more and 355 nm or less, and more preferably exhibits a maximum absorption at a wavelength of 330 nm or more and 350 nm or less.

[0052] Examples of the light-selective absorbing resin (C-2) include resins containing a structural unit derived from the above-mentioned light-selective absorbing compound (C-1) (hereinafter, sometimes referred to as the structural unit (C-1)). The light-selective absorbing resin (C-2) may be a homopolymer or copolymer containing the structural unit (C-1). The light-selective absorbing resin (C-2) is preferably a copolymer containing the structural unit (C-1).

[0053] The light-selective absorption resin (C-2) preferably contains the structural unit (C-1) in an amount of 0.1 to 90 mass % relative to all structural units, more preferably 1 to 75 mass %, even more preferably 5 to 60 mass %, and particularly preferably 10 to 50 mass %. The structural units contained in the light-selective absorption resin (C-2) other than the structural unit (C-1) include structural units derived from the monomers forming the resin (A) described above.Specific examples include the structural unit derived from the (meth)acrylic acid ester represented by the formula (a) described above, the structural unit derived from the monomer having the polar functional group described above, the structural unit derived from the styrene-based monomer described above, the structural unit derived from the vinyl-based monomer described above, and the structural unit derived from the (meth)acrylamide-based monomer described above. The structural units contained in the light-selective absorption resin (C-2) other than the structural unit (C-1) are preferably structural units derived from a (meth)acrylic acid ester represented by the above formula (a), structural units derived from a monomer having a polar functional group, etc., and more preferably structural units derived from a (meth)acrylic acid ester represented by the above formula (a), a monomer having a hydroxy group, a structural unit derived from a (meth)acrylamide-based monomer, etc. In particular, structural units derived from normal butyl acrylate, methyl acrylate, 2-ethylhexyl acrylate, normal octyl acrylate, etc. are preferred.

[0054] The light-selective absorption resin (C-2) may be a commercially available product, or may be synthesized by a known method (for example, JP-A No. 2012-25811). Specific examples of the light-selective absorption resin (C-2) include resins described in JP 2012-25811 A. Commercially available light-selective absorption resin (C-2) include the Vanaresin UVR series (Shin-Nakamura Chemical Co., Ltd.).

[0055] The content of the light-selective absorbing compound (C-1) or the light-selective absorbing resin (C-2) is usually 0.1 to 70 parts by mass, preferably 1.0 to 50 parts by mass, more preferably 5.0 to 30 parts by mass, even more preferably 7.5 to 25 parts by mass, and particularly preferably 10 to 20 parts by mass, relative to 100 parts by mass of the resin (A). When both the light-selective absorption compound (C-1) and the light-selective absorption resin (C-2) are contained, the total amount thereof may be within the above range.

[0056] The content ratio (mass ratio) of the light-selective absorbing compound (B) to the light-selective absorbing compound (C-1) is usually light-selective absorbing compound (C-1) / light-selective absorbing compound (B) = 1 / 1 to 10 / 1, and preferably 2 / 1 to 5 / 1. The content ratio (mass ratio) of the light-selective absorbing compound (B) to the light-selective absorbing resin (C-2) is usually light-selective absorbing resin (C-2) / light-selective absorbing compound (B) = 1 / 1 to 10 / 1, and preferably 2 / 1 to 5 / 1. When both the light-selective absorbing compound (C-1) and the light-selective absorbing resin (C-2) are contained, the content ratio (mass ratio) of the total of the light-selective absorbing compound (C-1) and the light-selective absorbing resin (C-2) to the light-selective absorbing compound (B) is usually, [total of the light-selective absorbing compound (C-1) and the light-selective absorbing resin (C-2)] / [light-selective absorbing compound (B)]=1 / 1 to 10 / 1, and preferably 2 / 1 to 5 / 1.

[0057] The pressure-sensitive adhesive composition of the present invention may further contain an initiator (D), a radically curable component (E), and a crosslinking agent (F).

[0058] <Initiator (D)> The initiator (D) may be any compound that induces a polymerization reaction of the light-selective absorption compound (C-1) or the optionally contained radical-curable component (E). The initiator (D) may be either a compound that induces a polymerization reaction by absorbing thermal energy (thermal polymerization initiator) or a compound that induces a polymerization reaction by absorbing light energy (photopolymerization initiator). Here, the light is preferably active energy rays such as visible light, ultraviolet light, X-rays, or electron beams.

[0059] Examples of the thermal polymerization initiator include a compound that generates radicals upon heating or the like (thermal radical generator), a compound that generates an acid upon heating or the like (thermal acid generator), and a compound that generates a base upon heating or the like (thermal base generator). Examples of the photopolymerization initiator include a compound that generates radicals by absorbing light energy (photoradical generator), a compound that generates acid by absorbing light energy (photoacid generator), and a compound that generates a base by absorbing light energy (photobase generator).

[0060] The initiator (D) is preferably selected from those suitable for the polymerization reaction of the light-selective absorption compound (C-1) or the radical-curable component (E), and is preferably a radical generator, more preferably a photoradical generator. Examples of the radical generator include a thermal radical generator and a photoradical generator. The initiator (D) may contain two or more types, and a photoradical generator and a thermal radical generator may be used in combination.

[0061] Examples of the radical generator include alkylphenone compounds, benzoin compounds, benzophenone compounds, oxime ester compounds, and phosphine compounds. The radical generator is preferably a photoradical generator, and from the viewpoint of the reactivity of the polymerization reaction, it is more preferably an oxime ester-based photoradical generator. By using an oxime ester-based radical generator, the reaction rate of the light-selective absorption compound (C-1) and the radical curing component (E) can be increased even under curing conditions with low illuminance or light quantity.

[0062] Examples of the alkylphenone compound include an α-aminoalkylphenone compound, an α-hydroxyalkylphenone compound, and an α-alkoxyalkylphenone compound. Examples of the α-aminoalkylphenone compound include 2-methyl-2-morpholino-1-(4-methylsulfanylphenyl)propan-1-one, 2-dimethylamino-1-(4-morpholinophenyl)-2-benzylbutan-1-one, 2-dimethylamino-1-(4-morpholinophenyl)-2-(4-methylphenylmethyl)butan-1-one, and the like, and preferred examples include 2-methyl-2-morpholino-1-(4-methylsulfanylphenyl)propan-1-one, 2-dimethylamino-1-(4-morpholinophenyl)-2-benzylbutan-1-one, and the like. As the α-aminoalkylphenone compound, commercially available products such as Irgacure (registered trademark) 127, 184, 369, 369E, 379EG, 651, 907, 1173, and 2959 (all manufactured by BASF Japan Ltd.) and Seikuol (registered trademark) BEE (manufactured by Seiko Chemical Co., Ltd.) may be used.

[0063] Examples of the benzoin compound include benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, and benzoin isobutyl ether.

[0064] Examples of the benzophenone compound include benzophenone, methyl o-benzoylbenzoate, 4-phenylbenzophenone, 4-benzoyl-4'-methyldiphenyl sulfide, 3,3',4,4'-tetra(tert-butylperoxycarbonyl)benzophenone, 2,4,6-trimethylbenzophenone, etc. Commercially available benzophenone compounds may be used.

[0065] Examples of the oxime ester compound include N-benzoyloxy-1-(4-phenylsulfanylphenyl)butan-1-one-2-imine, N-benzoyloxy-1-(4-phenylsulfanylphenyl)octan-1-one-2-imine, N-acetoxy-1-[9-ethyl-6-(2-methylbenzoyl)-9H-carbazol-3-yl]ethan-1-imine, and N-acetoxy-1-[9-ethyl-6-{2-methyl-4-(3,3-dimethyl-2,4-dioxacyclopentanylmethyloxy)benzoyl}-9H-carbazol-3-yl]ethan-1-imine. As the oxime compound, commercially available products such as Irgacure OXE-01, OXE-02, and OXE-03 (all manufactured by BASF Japan Ltd.), N-1919, NCI-730, NCI-831, and NCI-930 (manufactured by ADEKA Corporation), and PBG3057 (manufactured by TRONLY Corporation) may be used.

[0066] Examples of the phosphine compound include acylphosphine oxides such as phenyl(2,4,6-trimethylbenzoyl)phosphine oxide and diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide. Examples of the phosphine compound include Irgacure (registered trademark) TPO and Irgacure 819 (manufactured by BASF Japan Ltd.).

[0067] Examples of the acid generator include onium salts such as aromatic iodonium salts and aromatic sulfonium salts; aromatic diazonium salts; and iron-arene complexes.

[0068] The aromatic iodonium salt is a compound having a diaryliodonium cation, and a typical example of the cation is a diphenyliodonium cation. The aromatic sulfonium salt is a compound having a triarylsulfonium cation, and a typical example of the cation is a triphenylsulfonium cation or a 4,4'-bis(diphenylsulfonio)diphenylsulfide cation. The aromatic diazonium salt is a compound having a diazonium cation, and a typical example of the cation is a benzenediazonium cation. The iron-arene complex is typically a cyclopentadienyliron(II) arene cation complex salt.

[0069] The cations shown above are paired with anions (negative ions) to form photocation generators. Examples of anions that form photocation generators include special phosphorus anions [(Rf) n PF 6-n ] - , hexafluorophosphate anion PF6 - , hexafluoroantimonate anion SbF6 - , pentafluorohydroxyantimonate anion SbF5(OH) - , hexafluoroarsenate anion AsF6 - , tetrafluoroborate anion BF4 - , tetrakis(pentafluorophenyl)borate anion B(C6F5)4 - Among them, from the viewpoint of the curability of the cationic polymerizable compound and the safety of the resulting adhesive layer, a special phosphorus-based anion [(Rf) n PF 6-n ] - , hexafluorophosphate anion PF6 - , tetrakis(pentafluorophenyl)borate anion B(C6F5)4 - , hexafluoroantimonate anion SbF6 - It is preferable that:

[0070] Examples of the photobase generator include carbamate compounds, α-aminoketone compounds, quaternary ammonium compounds, O-acyloxime compounds, and aminocyclopropenone compounds.

[0071] Examples of carbamate compounds include 1-(2-anthraquinonyl)ethyl 1-piperidinecarboxylate, 1-(2-anthraquinonyl)ethyl 1H-2-ethylimidazole-1-carboxylate, 9-anthrylmethyl 1-piperidinecarboxylate, 9-anthrylmethyl N,N-diethylcarbamate, 9-anthrylmethyl N-propylcarbamate, 9-anthrylmethyl N-cyclohexylcarbamate, 9-anthrylmethyl 1H-imidazole-1-carboxylate, 9-anthrylmethyl N,N-dioctylcarbamate, 9-anthrylmethyl 1-(4-hydroxypiperidine)carboxylate, 1-pyrenylmethyl 1-piperidinecarboxylate, bis[1-(2-anthraquinonyl)ethyl] 1,6-hexanediylbiscarbamate, and bis(9-anthrylmethyl) 1,6-hexanediylbiscarbamate. Known examples of α-aminoketone compounds include 1-phenyl-2-(4-morpholinobenzoyl)-2-dimethylaminobutane and 2-(4-methylthiobenzoyl)-2-morpholinopropane.

[0072] Examples of quaternary ammonium compounds that can be used as photobase generators include 1-(4-phenylthiophenacyl)-1-azonia-4-azabicyclo[2,2,2]octanetetraphenylborate, 5-(4-phenylthiophenacyl)-1-aza-5-azoniabicyclo[4,3,0]-5-nonenetetraphenylborate, and 8-(4-phenylthiophenacyl)-1-aza-8-azoniabicyclo[5,4,0]-7-undecenetetraphenylborate. Examples of aminocyclopropenone compounds that can be used as photobase generators include 2-diethylamino-3-phenylcyclopropenone, 2-diethylamino-3-(1-naphthyl)cyclopropenone, 2-pyrrolidinyl-3-phenylcyclopropenone, 2-imidazolyl-3-phenylcyclopropenone, and 2-isopropylamino-3-phenylcyclopropenone.

[0073] Examples of thermal base generators include carbamate derivatives such as 2-(4-biphenyl)-2-propyl carbamate and 1,1-dimethyl-2-cyanoethyl carbamate, urea derivatives such as urea and N,N,N'-trimethylurea, dihydropyridine derivatives such as 1,4-dihydronicotinamide, dicyandiamide, and salts of acids and bases such as organic salts and inorganic salts.

[0074] The content of the initiator (D) is usually 0.01 to 20 parts by mass, preferably 0.1 to 10 parts by mass, more preferably 0.5 to 5 parts by mass, and even more preferably 1 to 3 parts by mass, relative to 100 parts by mass of the resin (A).

[0075] <Radical curing component (E)> The radically curable component (E) may be a monomer or oligomer that is cured by a radical polymerization reaction. Examples of the radically curable component (E) include monofunctional or polyfunctional (meth)acrylate compounds, styrene compounds, vinyl compounds, and the like. The pressure-sensitive adhesive composition of the present invention may contain two or more types of radically curable components (E).

[0076] Examples of (meth)acrylate compounds include (meth)acrylate monomers having at least one (meth)acryloyloxy group in the molecule, (meth)acrylamide monomers, and (meth)acryl oligomers having at least two (meth)acryloyl groups in the molecule, and other (meth)acryl group-containing compounds. The (meth)acrylic oligomer is preferably a (meth)acrylate oligomer having at least two (meth)acryloyloxy groups in the molecule. The (meth)acrylic compounds may be used alone or in combination of two or more.

[0077] Examples of the (meth)acrylate monomer include a monofunctional (meth)acrylate monomer having one (meth)acryloyloxy group in the molecule, a bifunctional (meth)acrylate monomer having two (meth)acryloyloxy groups in the molecule, and a polyfunctional (meth)acrylate monomer having three or more (meth)acryloyloxy groups in the molecule.

[0078] Examples of monofunctional (meth)acrylate monomers include alkyl (meth)acrylates. In the case of alkyl (meth)acrylates, when the alkyl group has 3 or more carbon atoms, the alkyl group may be linear, branched, or cyclic. Examples of alkyl (meth)acrylates include methyl (meth)acrylate, ethyl (meth)acrylate, isopropyl (meth)acrylate, butyl (meth)acrylate, isobutyl (meth)acrylate, t-butyl (meth)acrylate, and 2-ethylhexyl (meth)acrylate. Examples of monofunctional (meth)acrylate monomers include aralkyl (meth)acrylates such as benzyl (meth)acrylate; (meth)acrylates of terpene alcohols such as isobornyl (meth)acrylate; (meth)acrylates having a tetrahydrofurfuryl structure such as tetrahydrofurfuryl (meth)acrylate; (meth)acrylates having a cycloalkyl group in the alkyl group moiety such as cyclohexyl (meth)acrylate, cyclohexylmethyl methacrylate, dicyclopentanyl acrylate, dicyclopentenyl (meth)acrylate, and 1,4-cyclohexanedimethanol monoacrylate; aminoalkyl (meth)acrylates such as N,N-dimethylaminoethyl (meth)acrylate; and (meth)acrylates having an ether bond in the alkyl group moiety such as 2-phenoxyethyl (meth)acrylate, dicyclopentenyloxyethyl (meth)acrylate, ethyl carbitol (meth)acrylate, and phenoxypolyethylene glycol (meth)acrylate.

[0079] Furthermore, examples of the monofunctional (meth)acrylate monomer include monofunctional (meth)acrylates having a hydroxyl group at the alkyl moiety and monofunctional (meth)acrylates having a carboxyl group at the alkyl moiety. Examples of the monofunctional (meth)acrylates having a hydroxyl group at the alkyl moiety include 2-hydroxyethyl (meth)acrylate, 2- or 3-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 2-hydroxy-3-phenoxypropyl (meth)acrylate, trimethylolpropane mono(meth)acrylate, and pentaerythritol mono(meth)acrylate. Examples of monofunctional (meth)acrylates having a carboxyl group in the alkyl moiety include 2-carboxyethyl (meth)acrylate, ω-carboxy-polycaprolactone (n=2) mono(meth)acrylate, 1-[2-(meth)acryloyloxyethyl]phthalic acid, 1-[2-(meth)acryloyloxyethyl]hexahydrophthalic acid, 1-[2-(meth)acryloyloxyethyl]succinic acid, 4-[2-(meth)acryloyloxyethyl]trimellitic acid, and N-(meth)acryloyloxy-N',N'-dicarboxymethyl-p-phenylenediamine.

[0080] The (meth)acrylamide monomer is preferably a (meth)acrylamide having a substituent at the N-position. A typical example of the N-position substituent is an alkyl group, but it may form a ring together with the nitrogen atom of the (meth)acrylamide, and this ring may have an oxygen atom as a ring member in addition to the carbon atom and the nitrogen atom of the (meth)acrylamide. Furthermore, a substituent such as an alkyl or oxo (=O) may be bonded to the carbon atom constituting the ring.

[0081] Examples of N-substituted (meth)acrylamides include N-alkyl(meth)acrylamides such as N-methyl(meth)acrylamide, N-ethyl(meth)acrylamide, N-isopropyl(meth)acrylamide, Nn-butyl(meth)acrylamide, Nt-butyl(meth)acrylamide, and N-hexyl(meth)acrylamide; and N,N-dialkyl(meth)acrylamides such as N,N-dimethyl(meth)acrylamide and N,N-diethyl(meth)acrylamide. The N-substituent may be an alkyl group having a hydroxyl group, examples of which include N-hydroxymethyl(meth)acrylamide, N-(2-hydroxyethyl)(meth)acrylamide, and N-(2-hydroxypropyl)(meth)acrylamide. Furthermore, specific examples of the N-substituted (meth)acrylamides forming the above-mentioned 5- or 6-membered ring include N-acryloylpyrrolidine, 3-acryloyl-2-oxazolidinone, 4-acryloylmorpholine, N-acryloylpiperidine, and N-methacryloylpiperidine.

[0082] As the bifunctional (meth)acrylate monomer, alkylene glycol di(meth)acrylates such as ethylene glycol di(meth)acrylate, 1,3-butanediol di(meth)acrylate, 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,9-nonanediol di(meth)acrylate, and neopentyl glycol di(meth)acrylate; polyoxyalkylene glycol di(meth)acrylates such as diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, dipropylene glycol di(meth)acrylate, tripropylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate, and polytetramethylene glycol di(meth)acrylate; di(meth)acrylates of halogen-substituted alkylene glycols such as tetrafluoroethylene glycol di(meth)acrylate; Di(meth)acrylates of aliphatic polyols such as trimethylolpropane di(meth)acrylate, ditrimethylolpropane di(meth)acrylate, and pentaerythritol di(meth)acrylate; hydrogenated dicyclopentadiene or tricyclodecane dialkanol di(meth)acrylates such as hydrogenated dicyclopentadienyl di(meth)acrylate and tricyclodecane dimethanol di(meth)acrylate; Di(meth)acrylates of dioxane glycol or dioxane dialkanol such as 1,3-dioxane-2,5-diyl di(meth)acrylate (also known as dioxane glycol di(meth)acrylate); Di(meth)acrylates of alkylene oxide adducts of bisphenol A or bisphenol F, such as bisphenol A ethylene oxide adduct diacrylate and bisphenol F ethylene oxide adduct diacrylate; Epoxy di(meth)acrylates of bisphenol A or bisphenol F, such as an acrylic acid adduct of bisphenol A diglycidyl ether and an acrylic acid adduct of bisphenol F diglycidyl ether; Silicone di(meth)acrylate; Hydroxypivalic acid neopentyl glycol ester di(meth)acrylate; 2,2-Bis[4-(meth)acryloyloxyethoxyethoxyphenyl]propane; 2,2-Bis[4-(meth)acryloyloxyethoxyethoxycyclohexyl]propane; Di(meth)acrylate of [2-(2-hydroxy-1,1-dimethylethyl)-5-ethyl-5-hydroxymethyl-1,3-dioxane]; tris(hydroxyethyl)isocyanurate di(meth)acrylate; and the like.

[0083] Examples of trifunctional or higher polyfunctional (meth)acrylate monomers include glycerin tri(meth)acrylate, alkoxylated glycerin tri(meth)acrylate, trimethylolpropane tri(meth)acrylate, ditrimethylolpropane tri(meth)acrylate, ditrimethylolpropane tetra(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol tetra(meth)acrylate, and dipentaerythritol penta(meth)acrylate. poly(meth)acrylates of trifunctional or higher aliphatic polyols such as dipentaerythritol hexa(meth)acrylate; poly(meth)acrylates of trifunctional or higher halogen-substituted polyols; tri(meth)acrylates of alkylene oxide adducts of glycerin; tri(meth)acrylates of alkylene oxide adducts of trimethylolpropane; 1,1,1-tris[(meth)acryloyloxyethoxyethoxy]propane; and tris(hydroxyethyl)isocyanurate tri(meth)acrylate. Commercially available products may also be used, such as A-DPH-12E, A-TMPT, and A-9300 (manufactured by Shin-Nakamura Chemical Co., Ltd.).

[0084] Examples of the (meth)acrylic oligomer include urethane (meth)acrylic oligomer, polyester (meth)acrylic oligomer, and epoxy (meth)acrylic oligomer.

[0085] The urethane (meth)acrylic oligomer is a compound having a urethane bond (-NHCOO-) and at least two (meth)acryloyl groups in the molecule. Specifically, it may be a urethane reaction product of a hydroxyl group-containing (meth)acrylic monomer having at least one (meth)acryloyl group and at least one hydroxyl group in the molecule with a polyisocyanate, or a urethane reaction product of a terminal isocyanato group-containing urethane compound obtained by reacting a polyol with a polyisocyanate with a (meth)acrylic monomer having at least one (meth)acryloyl group and at least one hydroxyl group in the molecule.

[0086] The hydroxyl group-containing (meth)acrylic monomer used in the urethanization reaction can be, for example, a hydroxyl group-containing (meth)acrylate monomer, specific examples of which include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 2-hydroxy-3-phenoxypropyl (meth)acrylate, glycerin di(meth)acrylate, trimethylolpropane di(meth)acrylate, pentaerythritol tri(meth)acrylate, and dipentaerythritol penta(meth)acrylate. Specific examples other than the hydroxyl group-containing (meth)acrylate monomer include N-hydroxyalkyl (meth)acrylamide monomers such as N-hydroxyethyl (meth)acrylamide and N-methylol (meth)acrylamide.

[0087] Examples of polyisocyanates that can be subjected to the urethanization reaction with the hydroxyl group-containing (meth)acrylic monomer include hexamethylene diisocyanate, lysine diisocyanate, isophorone diisocyanate, dicyclohexylmethane diisocyanate, tolylene diisocyanate, xylylene diisocyanate, diisocyanates obtained by hydrogenating aromatic isocyanates among these diisocyanates (e.g., hydrogenated tolylene diisocyanate, hydrogenated xylylene diisocyanate, etc.), di- or tri-isocyanates such as triphenylmethane triisocyanate and dibenzylbenzene triisocyanate, and polyisocyanates obtained by polymerizing the above diisocyanates.

[0088] Furthermore, the polyol used to produce a urethane compound containing a terminal isocyanato group by reaction with a polyisocyanate may be an aromatic, aliphatic, or alicyclic polyol, as well as a polyester polyol, a polyether polyol, etc. Examples of aliphatic and alicyclic polyols include 1,4-butanediol, 1,6-hexanediol, ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, neopentyl glycol, trimethylolethane, trimethylolpropane, ditrimethylolpropane, pentaerythritol, dipentaerythritol, dimethylolheptane, dimethylolpropionic acid, dimethylolbutanoic acid, glycerin, and hydrogenated bisphenol A.

[0089] The polyester polyol is obtained by a dehydration condensation reaction between the above-mentioned polyol and a polybasic carboxylic acid or an anhydride thereof. Examples of the polybasic carboxylic acid or anhydride thereof, when expressed by adding "(anhydride)" to the anhydride, include succinic acid (anhydride), adipic acid, maleic acid (anhydride), itaconic acid (anhydride), trimellitic acid (anhydride), pyromellitic acid (anhydride), phthalic acid (anhydride), isophthalic acid, terephthalic acid, and hexahydrophthalic acid (anhydride).

[0090] The polyether polyol may be a polyalkylene glycol, or a polyoxyalkylene-modified polyol obtained by reacting the above-mentioned polyol or dihydroxybenzene with an alkylene oxide.

[0091] The polyester (meth)acrylate oligomer means an oligomer having an ester bond and at least two (meth)acryloyloxy groups in the molecule. The polyester (meth)acrylate oligomer can be obtained, for example, by subjecting (meth)acrylic acid, a polybasic carboxylic acid or anhydride thereof, and a polyol to a dehydration condensation reaction. Examples of polybasic carboxylic acids or anhydrides thereof include succinic anhydride, adipic acid, maleic anhydride, itaconic anhydride, trimellitic anhydride, pyromellitic anhydride, hexahydrophthalic anhydride, phthalic acid, succinic acid, maleic acid, itaconic acid, trimellitic acid, pyromellitic acid, hexahydrophthalic acid, phthalic acid, isophthalic acid, and terephthalic acid. Examples of polyols include 1,4-butanediol, 1,6-hexanediol, ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, neopentyl glycol, trimethylolethane, trimethylolpropane, ditrimethylolpropane, pentaerythritol, dipentaerythritol, dimethylolheptane, dimethylolpropionic acid, dimethylolbutanoic acid, glycerin, and hydrogenated bisphenol A.

[0092] Epoxy (meth)acrylic oligomers can be obtained by the addition reaction of polyglycidyl ether and (meth)acrylic acid. The epoxy (meth)acrylic oligomer has at least two (meth)acryloyloxy groups in the molecule. Examples of polyglycidyl ethers include ethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, tripropylene glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, and bisphenol A diglycidyl ether.

[0093] Examples of styrene-based compounds 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.

[0094] 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.

[0095] The radically curable component (E) is preferably a (meth)acrylate compound, more preferably a polyfunctional (meth)acrylate compound, and the polyfunctional (meth)acrylate compound is preferably tri- or higher functional.

[0096] The content of the radically curable component (E) is usually 0.5 to 100 parts by mass, preferably 1 to 70 parts by mass, more preferably 3 to 50 parts by mass, even more preferably 5 to 30 parts by mass, and particularly preferably 7.5 to 20 parts by mass, relative to 100 parts by mass of the resin (A).

[0097] <Crosslinking agent (F)> Examples of the crosslinking agent (F) 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.

[0098] The isocyanate crosslinking agent is preferably a compound having at least two isocyanato groups (-NCO) in the molecule, and examples thereof include aliphatic isocyanate compounds (such as hexamethylene diisocyanate), alicyclic isocyanate compounds (such as isophorone diisocyanate, hydrogenated diphenylmethane diisocyanate, hydrogenated xylylene diisocyanate), and aromatic isocyanate compounds (such as tolylene diisocyanate, xylylene diisocyanate diphenylmethane diisocyanate, naphthalene diisocyanate, triphenylmethane triisocyanate, etc.). The crosslinking agent (F) may also be a derivative of an adduct of the isocyanate compound with a polyhydric alcohol compound (e.g., an adduct with glycerol, trimethylolpropane, etc.), an isocyanurate, a biuret-type compound, or a urethane prepolymer-type isocyanate compound obtained by addition reaction with a polyether polyol, polyester polyol, acrylic polyol, polybutadiene polyol, polyisoprene polyol, etc. The crosslinking agent (F) may 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 a polyhydric alcohol compound (e.g., glycerol, trimethylolpropane), or isocyanurates. When the crosslinking agent (F) is an aromatic isocyanate compound and / or an adduct thereof with a polyhydric alcohol compound or an isocyanurate, the durability of the pressure-sensitive adhesive layer can be improved, possibly because it is advantageous for forming an optimal crosslink density (or crosslinked structure). In particular, when the crosslinking agent (F) is a tolylene diisocyanate compound and / or an adduct thereof with a polyhydric alcohol compound, the durability can be improved even when the pressure-sensitive adhesive layer is applied to a polarizing plate, for example.

[0099] The content of the crosslinking agent (F) is usually 0.01 to 25 parts by mass, preferably 0.1 to 15 parts by mass, more preferably 0.15 to 7 parts by mass, even more preferably 0.2 to 5 parts by mass, and particularly preferably 0.25 to 2 parts by mass, relative to 100 parts by mass of the resin (A).

[0100] The pressure-sensitive adhesive composition of the present invention may further contain a silane compound (G). Examples of the silane compound (G) 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 (G) may be a silicone oligomer. Specific examples of silicone oligomers, expressed in the form of combinations of monomers, are as follows:

[0101] 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-glycidyloxysilane copolymers containing 3-glycidoxypropyl groups, such as 3-glycidoxypropyltrimethoxysilane-tetramethoxysilane copolymer, 3-glycidoxypropyltriethoxysilane-tetramethoxysilane copolymer, 3-glycidoxypropyltriethoxysilane-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-tetraethoxysilane oligomer, 3-Methacryloyloxypropylmethyldimethoxysilane-tetramethoxysilane oligomer, 3-Methacryloyloxypropylmethyldimethoxysilane-tetraethoxysilane oligomer Methacryloyloxypropyl group-containing oligomers such as methacryloyloxypropyl methyldiethoxysilane-tetramethoxysilane oligomer, 3-methacryloyloxypropyl methyldiethoxysilane-tetraethoxysilane oligomer; 3-acryloyloxypropyl trimethoxysilane-tetramethoxysilane oligomer, 3-acryloyloxypropyl trimethoxysilane-tetraethoxysilane oligomer, 3-acryloyloxypropyl triethoxysilane-tetramethoxysilane oligomer acryloyloxypropyl group-containing oligomers such as 3-acryloyloxypropyltriethoxysilane-tetraethoxysilane oligomer, 3-acryloyloxypropylmethyldimethoxysilane-tetramethoxysilane oligomer, 3-acryloyloxypropylmethyldimethoxysilane-tetraethoxysilane oligomer, 3-acryloyloxypropylmethyldiethoxysilane-tetramethoxysilane oligomer, and 3-acryloyloxypropylmethyldiethoxysilane-tetraethoxysilane oligomer; vinyltrimethoxysilane Vinyl group-containing oligomers such as silane-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;

[0102] The silane compound (G) may be a silane compound represented by the following formula (g1): [ka] [In the formula, A 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 replaced by —O— or —CO—; R 41 represents an alkyl group having 1 to 5 carbon atoms, and R 42 , R 43 , R 44 , R 45 and R 46 each independently represents an alkyl group having 1 to 5 carbon atoms or an alkoxy group having 1 to 5 carbon atoms.]

[0103] Examples of the alkanediyl group having 1 to 20 carbon atoms represented by A include methylene, 1,2-ethanediyl, 1,3-propanediyl, 1,4-butanediyl, 1,5-pentanediyl, 1,6-hexanediyl, 1,7-heptanediyl, 1,8-octanediyl, 1,9-nonanediyl, 1,10-decanediyl, 1,12-dodecanediyl, 1,14-tetradecanediyl, 1,16-hexadecanediyl, 1,18-octadecanediyl, and 1,20-icosanediyl. Examples of the divalent alicyclic hydrocarbon group having 3 to 20 carbon atoms include 1,3-cyclopentanediyl and 1,4-cyclohexanediyl. Examples of the alkanediyl group and the alicyclic hydrocarbon group in which -CH2- is replaced with -O- or -CO- include -CH2CH2-O-CH2CH2-, -CH2CH2-O-CH2CH2-O-CH2CH2-, -CH2CH2-O-CH2CH2-O-CH2CH2-O-CH2CH2-, -CH2CH2-CO-O-CH2CH2-, -CH2CH2-O-CH2CH2-CO-O-CH2CH2-, -CH2CH2CH2CH2-O-CH2CH2- and -CH2CH2CH2CH2-O-CH2CH2CH2-.

[0104] R 41 ~R 46 Examples of the alkyl group having 1 to 5 carbon atoms represented by the formula (I) include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a tert-butyl group, and a pentyl group. 42 ~R 46 Examples of the alkoxy group having 1 to 5 carbon atoms represented by the formula (I) include a methoxy group, an ethoxy group, a propoxy group, an isopropoxy group, a butoxy group, an isobutoxy group, a tert-butoxy group, and a pentyloxy group.

[0105] Examples of the silane compound represented by formula (g1) include bis(triC1-5 alkyl) 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.

[0106] The content of the silane compound (G) is usually 0.01 to 20 parts by mass, preferably 0.1 to 10 parts by mass, more preferably 0.15 to 7 parts by mass, even more preferably 0.2 to 5 parts by mass, and particularly preferably 0.25 to 2 parts by mass, relative to 100 parts by mass of the resin (A).

[0107] The pressure-sensitive adhesive composition may further contain one or more additives such as antistatic agents, solvents, crosslinking catalysts, tackifiers, plasticizers, softeners, pigments, rust inhibitors, inorganic fillers, and light-scattering fine particles.

[0108] The pressure-sensitive adhesive layer of the present invention can be formed, for example, by dissolving or dispersing the pressure-sensitive adhesive composition of the present invention in a solvent to prepare a solvent-containing pressure-sensitive adhesive composition, which is then applied to the surface of a substrate, dried, and then irradiated with active energy rays. The pressure-sensitive adhesive layer of the present invention can also be said to be a photocured product of the pressure-sensitive adhesive composition.

[0109] The substrate is preferably a plastic film, specifically a release film that has been subjected to a release treatment, such as a film made of a resin such as polyethylene terephthalate, polybutylene terephthalate, polycarbonate, or polyarylate, and one side of which has been subjected to a release treatment such as silicone treatment.

[0110] The conditions (drying temperature, drying time) for drying the coating film formed from the solvent-containing pressure-sensitive adhesive composition can be appropriately set depending on the composition and concentration, but are preferably 60 to 150° C. and 1 to 60 minutes. The irradiation of the coating film with active energy rays after drying is preferably ultraviolet irradiation. The illuminance of the ultraviolet light to be irradiated is 10 mW / cm. 2 ~3000mW / cm 2 It is preferable that the integrated light intensity of the ultraviolet rays is 10 mJ / cm. 2 ~5000mJ / cm 2 It is preferable that: The ultraviolet lamp for irradiating ultraviolet light may be a mercury lamp, a metal halide lamp, or an LED lamp.

[0111] The pressure-sensitive adhesive layer of the present invention is preferably a pressure-sensitive adhesive layer that satisfies the following formula (3), and more preferably a pressure-sensitive adhesive layer that satisfies formula (4). A(380)≧0.6 (3) [In formula (3), A(380) represents absorbance at a wavelength of 380 nm.] A(380) / A(420)≧5 (4) [In formula (4), A(380) represents the absorbance at a wavelength of 380 nm, and A(420) represents the absorbance at a wavelength of 420 nm.]

[0112] The larger the A(380) value, the higher the absorption at a wavelength of 380 nm. If the A(380) value is less than 0.6, the absorption at a wavelength of 380 nm is low, and components that are susceptible to deterioration by light near ultraviolet light (for example, display devices such as organic EL elements and liquid crystal retardation films) are likely to deteriorate. The A(380) value is preferably 0.75 or more, more preferably 0.85 or more, and particularly preferably 1.0 or more. There is no particular upper limit, but it is usually 10 or less. The value of A(380) / A(420) represents the magnitude of absorption at a wavelength of 380 nm relative to the magnitude of absorption at a wavelength of 420 nm, and a larger value indicates a specific absorption in the wavelength region near ultraviolet. The value of A(380) / A(420) is preferably 5 or more, more preferably 20 or more, even more preferably 50 or more, and particularly preferably 100 or more.

[0113] The thickness of the pressure-sensitive adhesive layer of the present invention is usually less than 200 μm, preferably 100 μm or less, more preferably 20 μm or less, even more preferably 12 μm or less or less than 12 μm, still more preferably 10 μm or less, particularly preferably 7 μm or less, and usually 0.1 μm or more, preferably 0.5 μm or more, more preferably 1 μm or more, and even more preferably 2 μm or more. According to the present invention, even a thin adhesive layer having a thickness of less than 12 μm can sufficiently absorb ultraviolet light, which is advantageous from the viewpoint of thinning of display devices.

[0114] The gel fraction of the pressure-sensitive adhesive layer of the present invention is usually 50 to 99.9% by mass, preferably 60 to 99% by mass, more preferably 70 to 95% by mass, and even more preferably 75 to 90% by mass.

[0115] <Optical film with adhesive layer> The pressure-sensitive adhesive composition of the present invention and a pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition can be used, for example, for laminating optical films. The present invention also includes an optical film with a pressure-sensitive adhesive layer, in which an optical film is laminated on at least one surface of the pressure-sensitive adhesive layer of the present invention. The optical film with a pressure-sensitive adhesive layer of the present invention can be formed by dissolving or dispersing the pressure-sensitive adhesive composition in a solvent to prepare a solvent-containing pressure-sensitive adhesive composition, then applying the solvent-containing pressure-sensitive adhesive composition to the surface of an optical film, drying the composition, and then irradiating the composition with active energy rays. Alternatively, the optical film can also be obtained by forming a pressure-sensitive adhesive layer on a release film in the same manner, and then laminating (transferring) the pressure-sensitive adhesive layer onto the surface of the optical film.

[0116] An optical film is a film having optical functions such as transmitting, reflecting, and absorbing light. The optical film may be a single-layer film or a multi-layer film. Examples of the optical film include a polarizing film, a retardation film, a brightness-enhancing film, an anti-glare film, an anti-reflection film, a diffusion film, and a light-collecting film. A polarizing film, a retardation film, or a laminate film thereof is preferred.

[0117] The light-condensing film is used for the purpose of controlling the light path, and can be a prism array sheet, a lens array sheet, a dot-attached sheet, or the like.

[0118] Brightness enhancement films are used to improve the brightness of liquid crystal displays that use polarizing plates. Specific examples include reflective polarization separation sheets designed to generate anisotropy in reflectance by laminating multiple thin films with different anisotropies in refractive index, and circular polarization separation sheets in which an oriented film of a cholesteric liquid crystal polymer or an oriented liquid crystal layer of the cholesteric liquid crystal polymer is supported on a substrate film.

[0119] A polarizing film is a film that 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).For example, a film in which a dichroic dye is adsorbed and oriented on a polyvinyl alcohol-based resin film can be used. Examples of dichroic dyes include iodine and dichroic organic dyes. The saponification degree of the polyvinyl alcohol resin is usually 85 mol% to 100 mol%, preferably 98 mol% or more. The polyvinyl alcohol resin may be modified, for example, polyvinyl formal or polyvinyl acetal modified with an aldehyde. The polymerization degree of the polyvinyl alcohol resin is usually 1,000 to 10,000, preferably 1,500 to 5,000.

[0120] Typically, a film made from a polyvinyl alcohol-based resin is used as the raw film for the polarizing film. The polyvinyl alcohol-based resin can be formed into a film by a known method. The thickness of the raw film is typically 1 to 150 μm, and considering ease of stretching, it is preferably 10 μm or more.

[0121] A polarizing film is produced, for example, by subjecting a raw film to uniaxial stretching, dyeing the film with a dichroic dye to allow the dichroic dye to be adsorbed, treating the film with an aqueous boric acid solution, washing the film with water, and finally drying. The thickness of the polarizing film is usually 1 to 30 μm, and from the viewpoint of reducing the thickness of the pressure-sensitive adhesive layer-attached optical film, it is preferably 20 μm or less, more preferably 15 μm or less, and particularly preferably 10 μm or less.

[0122] It is preferable that the polarizing film be a polarizing plate having a protective film provided on at least one surface thereof via an adhesive. As the adhesive, a known adhesive may be used, and it may be a water-based adhesive or an active energy ray curable adhesive.

[0123] Examples of aqueous adhesives include conventional aqueous adhesives (e.g., adhesives made from aqueous polyvinyl alcohol resin solutions, aqueous two-component urethane emulsion adhesives, crosslinkers such as aldehyde compounds, epoxy compounds, melamine compounds, methylol compounds, isocyanate compounds, amine compounds, and polyvalent metal salts). Of these, aqueous adhesives made from aqueous polyvinyl alcohol resin solutions are preferred. When using an aqueous adhesive, it is preferable to carry out a drying step to remove water contained in the aqueous adhesive after laminating the polarizing film and the protective film. After the drying step, a curing step may be carried out, in which the adhesive is cured at a temperature of, for example, about 20 to 45°C. The adhesive layer formed from the aqueous adhesive is usually 0.001 to 5 μm thick.

[0124] The active energy ray-curable adhesive refers to an adhesive that is cured by irradiation with active energy rays such as ultraviolet rays or electron beams. Examples of such adhesives include a curable composition containing a polymerizable compound and a photopolymerization initiator, a curable composition containing a photoreactive resin, and a curable composition containing a binder resin and a photoreactive crosslinking agent, and preferably an ultraviolet ray-curable adhesive.

[0125] Examples of methods for laminating a polarizing film and a protective film include methods in which at least one of the laminating surfaces is subjected to a surface activation treatment such as saponification treatment, corona treatment, plasma treatment, etc. When protective films are laminated to both surfaces of a polarizing film, the adhesives used to laminate these resin films may be the same or different types of adhesives.

[0126] The protective film is preferably a film formed from a light-transmitting thermoplastic resin. Specific examples include films made of polyolefin resins, cellulose resins, polyester resins, (meth)acrylic resins, or mixtures or copolymers thereof. When protective films are provided on both sides of the polarizing film, the protective films used may be films made of different thermoplastic resins or films made of the same thermoplastic resin. When a protective film is laminated on at least one surface of the polarizing film, the protective film is preferably a protective film made of a polyolefin resin or a cellulose resin. The use of these films can effectively suppress the shrinkage of the polarizing film in a high-temperature environment without impairing the optical properties of the polarizing film. The protective film may also be an oxygen-shielding layer.

[0127] A preferred configuration of the polarizing plate is a polarizing plate in which a protective film is laminated on at least one surface of a polarizing film via an adhesive layer. When a protective film is laminated on only one surface of a polarizing film, it is more preferably laminated on the viewing side. The protective film laminated on the viewing side is preferably a protective film made of a triacetyl cellulose-based resin or a cycloolefin-based resin. The protective film may be an unstretched film, or may be stretched in any direction to have a retardation. A surface treatment layer such as a hard coat layer or an anti-glare layer may be provided on the surface of the protective film laminated on the viewing side. When protective films are laminated on both sides of the polarizing film, the protective film on the panel side (opposite the viewing side) is preferably a protective film or a retardation film made of a triacetyl cellulose resin, a cycloolefin resin, or an acrylic resin. The retardation film may be a zero retardation film, which will be described later.

[0128] The retardation film is an optical film that exhibits optical anisotropy, and examples thereof 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. Furthermore, the retardation film may be a retardation film in which optical anisotropy is exhibited by coating and orienting a liquid crystalline compound on a substrate. In this specification, the retardation film includes a zero retardation film, and also includes films called uniaxial retardation films, low photoelasticity retardation films, wide viewing angle retardation films, and the like.

[0129] Zero retardation film means that the front retardation R e and retardation R th The zero retardation film refers to an optically isotropic film in which both the retardation and the thickness are -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, "Zero Tack (registered trademark)" sold by Konica Minolta Opto, Inc., and "ZF-14" (trade name) sold by Zeon Corporation.

[0130] In the optical film of the present invention, the retardation film is preferably a retardation film in which optical anisotropy is exhibited by coating and aligning a liquid crystalline compound.

[0131] The films in which optical anisotropy is exhibited by coating and orienting a liquid crystal compound include the following first to fifth embodiments. First form: Retardation film in which rod-like liquid crystal compounds are aligned horizontally to the supporting substrate Second form: Retardation film in which rod-like liquid crystal compounds are aligned perpendicular to the substrate Third form: Retardation film in which the direction of the rod-shaped liquid crystal compound changes in a helical orientation in the plane. Fourth form: Retardation film in which the discotic liquid crystal compound is tilted. Fifth form: Biaxial retardation film in which discotic liquid crystal compounds are aligned perpendicular to the substrate

[0132] For example, the first, second, and fifth types of retardation films are preferably used as optical films for organic electroluminescence displays. Alternatively, retardation films of these types may be laminated and used.

[0133] When the retardation film 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 film 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 film of the present invention, when the retardation film has the first type and 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.

[0134] When the retardation film is a film having an optically anisotropic layer, examples of the polymerizable liquid crystal compound include compounds having a polymerizable group among the compounds described in "3.8.6 Network (fully 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.

[0135] Examples of a method for producing a retardation film from a polymer in an aligned state of a polymerizable liquid crystal compound include the method described in JP-A-2010-31223.

[0136] In the second embodiment, the front retardation value Re(550) may be adjusted to a range of 0 to 10 nm, preferably 0 to 5 nm, and the thickness direction retardation value R th The retardation value R in the thickness direction, which means the refractive index anisotropy in the thickness direction, may be adjusted to a range of −10 to −300 nm, preferably −20 to −200 nm. th is the phase difference value R measured by tilting the in-plane fast axis by 50 degrees. 50 and the in-plane retardation value R0. That is, the retardation value R th is the in-plane retardation value R0, and the retardation value R measured at a 50-degree tilt with the fast axis as the tilt axis. 50 , the thickness d of the retardation film, and the average refractive index n0 of the retardation film, are calculated by the following equations (10) to (12):x , n y and n z and then substitute these into equation (9) to perform the calculation.

[0137] R th =[(n x +n y ) / 2-n z ]×d (9) R0=(n x -n y )×d (10) R 50 =(n x -n y ')×d / cos(φ) (11) (n x +n y +n z ) / 3=n0(12) where: φ=sin -1 [sin(40°) / n0] n y '=n y ×n z / 〔n y 2 ×sin 2 (φ)+n z 2 ×cos 2 (φ) 1 / 2

[0138] Examples of films that exhibit optical anisotropy by coating and aligning liquid crystal compounds or films that exhibit optical anisotropy by coating inorganic layer compounds 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.

[0139] The retardation film may be a multilayer film having two or more layers, such as a retardation film having a protective film laminated on one or both sides thereof, or a retardation film having two or more retardation films laminated together via a pressure-sensitive adhesive or adhesive.

[0140] 1 to 5 show examples of the layer structure of the laminate of the present invention in which a release film is provided on the pressure-sensitive adhesive layer, the pressure-sensitive adhesive layer-attached optical film of the present invention, and the optical laminate. The laminate 10 shown in FIG. 1, in which a release film is provided on the adhesive layer, has a release film (separate film) 2 attached to one surface of the adhesive layer formed from the adhesive composition of the present invention for temporary protection of that surface. The pressure-sensitive adhesive layer-attached optical film 10A shown in FIG. 2 is an optical film with a pressure-sensitive adhesive layer, including a protective film 3, an adhesive layer 4, a polarizing film 5, a pressure-sensitive adhesive layer 1 formed from the pressure-sensitive adhesive composition of the present invention, and a release film 2. The protective film 3, the adhesive layer 4, and the polarizing film 5 constitute a polarizing plate 100 (optical film 40). The protective film 3 may have a retardation. Furthermore, a hard coat layer or the like may be further laminated on the protective film 3. 3 is an optical film with a pressure-sensitive adhesive layer including a protective film 3, an adhesive layer 4, a polarizing film 5, an adhesive layer 7, a protective film 6, a pressure-sensitive adhesive layer 1 formed from the pressure-sensitive adhesive composition of the present invention, and a retardation film 8. The protective film 3, the adhesive layer 4, the polarizing film 5, the adhesive layer 7, and the protective film 6 constitute a polarizing plate 100 (optical film 40). The optical laminate 10C shown in FIG. 4 and the optical laminate 10D shown in FIG. 5 are optical laminates including a protective film 3, an adhesive layer 4, a polarizing film 5, a pressure-sensitive adhesive layer 1 formed from the pressure-sensitive adhesive composition of the present invention, a retardation film 110 (optical film 40), a pressure-sensitive adhesive layer 1a, and a light-emitting element 30 (liquid crystal cell, organic EL cell). The protective film 3, the adhesive layer 4, and the polarizing film 5 constitute a polarizing plate 100 (optical film 40). The pressure-sensitive adhesive layer 1a may be a pressure-sensitive adhesive layer formed from a known pressure-sensitive adhesive composition, or may be a pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition of the present invention. 4 and 5, when the retardation film is a multilayer film, an example of the configuration includes a retardation film 110 (optical film 40) in which a quarter-wave retardation layer 70 that imparts a quarter-wave retardation to transmitted light and a half-wave retardation layer 50 that imparts a half-wave retardation to transmitted light are laminated via an adhesive layer or a pressure-sensitive adhesive layer 60, as shown in Fig. 4. Another example of the configuration includes a retardation film 110 (optical film 40) in which a quarter-wave retardation layer 50a and a positive C layer 80 are laminated via an adhesive layer or a pressure-sensitive adhesive layer 60, as shown in Fig. 5.

[0141] The quarter-wave retardation layer 70 that imparts a quarter-wave retardation to light and the half-wave retardation layer 50 that imparts a half-wave retardation to transmitted light in Fig. 4 may be the optical film of the first embodiment or the optical film of the fifth embodiment. In the configuration of Fig. 4, it is more preferable that at least one of them is the fifth embodiment. In the configuration of FIG. 5, the quarter-wave retardation layer 50a is preferably the optical film of the first embodiment, and more preferably satisfies the formulas (7) and (8).

[0142] <Liquid crystal display device> The pressure-sensitive adhesive composition of the present invention and an optical film with a pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition can be used in display devices such as organic EL display devices and liquid crystal display devices as an optical laminate laminated on a display device such as an organic EL element or a liquid crystal cell. [Example]

[0143] The present invention will be described in more detail below with reference to examples and comparative examples, but the present invention is not limited to these examples. In the examples, % and parts representing the content or amount used are by mass unless otherwise specified.

[0144] <Measurement of maximum absorption wavelength and gram absorption coefficient ε> A 2-butanone solution (0.006 g / L) of "FUV002B" (Fujifilm Corporation) was placed in a 1 cm quartz cell, and the quartz cell was placed in a UV-2450 spectrophotometer (Shimadzu Corporation). The absorbance was measured in 1 nm steps over the wavelength range of 300 to 800 nm using the double beam method. The gram extinction coefficient for each wavelength was calculated from the obtained absorbance value, the concentration of "FUV002B" in the solution, and the optical path length of the quartz cell. ε(λ)=A(λ) / CL (where ε(λ) represents the gram absorption coefficient (L / (g cm)) of "FUV002B" at a wavelength of λ nm, A(λ) represents the absorbance at a wavelength of λ nm, C represents the concentration of "FUV002B" in the solution (g / L), and L represents the optical path length (cm) of the quartz cell.) The maximum absorption wavelength of "FUV002B" was 370 nm. The ε(380) of "FUV002B" was 108.9 L / (g·cm), the ε(420) was 0.2 L / (g·cm), and the ε(380) / ε(420) ratio was 544.5.

[0145] (Polymerization Example 1): Preparation of acrylic resin (A1) A reaction vessel equipped with a condenser, nitrogen inlet, thermometer, and stirrer was charged with a mixture of 81.8 parts ethyl acetate as solvent, 96 parts butyl acrylate, 3 parts 2-hydroxyethylmethyl acrylate, and 1 part acrylic acid. The air in the vessel was purged with nitrogen gas to remove oxygen, and the internal temperature was raised to 55°C. A solution of 0.14 parts azobisisobutyronitrile (polymerization initiator) in 10 parts ethyl acetate was then added in its entirety. After the initiator addition, the temperature was maintained at this level for 1 hour. Ethyl acetate was then added continuously to the reaction vessel at a rate of 17.3 parts / hour while maintaining the internal temperature at 54-56°C. When the acrylic resin concentration reached 35%, the ethyl acetate addition was stopped. The temperature was maintained 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 1.47 million as measured by GPC in terms of polystyrene, and an Mw / Mn ratio of 5.5. This is designated as acrylic resin (A1). The resulting acrylic resin (A1) did not exhibit a maximum absorption in the wavelength range of 300 nm to 780 nm.

[0146] Example 1: Preparation of adhesive composition (1) A solution of acrylic resin (A1) as resin (A) in ethyl acetate (resin concentration: 20%) with 100 parts solids was mixed with 0.3 parts of crosslinking agent (F) (manufactured by Tosoh Corporation: trade name "Coronate L", isocyanate-based compound, solids content 75%), 0.28 parts of silane compound (G) (manufactured by Shin-Etsu Chemical Co., Ltd.: trade name "KBM3066"), 10 parts of radical curing component (E) (manufactured by Shin-Nakamura Chemical Co., Ltd.: trade name "A-DPH-12E", hexafunctional (meth)acrylate-based compound), and initiator (D) (manufactured by Shin-Nakamura Chemical Co., Ltd.: trade name "A-DPH-12E", hexafunctional (meth)acrylate-based compound). 1.5 parts of a photo-radical generator (product name "NCI-730" manufactured by DEKA Corporation, an oxime ester compound), 2.5 parts of a light-selective absorbing compound (B) (product name "FUV002B" manufactured by Fujifilm Corporation), and 10 parts of a light-selective absorbing compound (C-1) (product name "RUVA-93" manufactured by Otsuka Chemical Co., Ltd., 2-[2'-hydroxy-5'-(methacryloyloxyethyl)phenyl]benzotriazole) were mixed, and ethyl acetate was added to a solids concentration of 14%, to obtain a pressure-sensitive adhesive composition (1). The amount of the crosslinker is expressed in parts by mass as the active ingredient.

[0147] Examples 2 to 5 and Comparative Examples 1 to 11 Pressure-sensitive adhesive compositions (2) to (16) were prepared in the same manner as in Example 1, except that the components and the amounts of the components were changed as shown in Table 1 or Table 2. The blending amount of the crosslinking agent is the number of parts by mass as the active ingredient, and the blending amount of the acrylic resin (A1) is the number of parts by mass of the solid content.

[0148] [Table 1]

[0149] The abbreviations in Table 1 are as follows: ε(380) and ε(420) for RUVA-93, SB107, SB707, and EU-1990 were measured in the same manner as described above. <Resin (A)> Acrylic resin (A1): Acrylic resin (A1) prepared in Polymerization Example 1 <Light-selective absorption compound (B)> FUV-002B: Fujifilm Corporation, product name: FUV002B, maximum absorption wavelength λmax = 370 nm, ε(380) = 108.9, ε(420) = 0.2, ε(380) / ε(420)=544.5 <Light-selective absorption compound (C-1)> RUVA-93: manufactured by Otsuka Chemical Co., Ltd., trade name: RUVA-93, ε(380)=1.5, ε(420)=0, has a polymerizable group and a benzotriazole skeleton in the molecule, and has a maximum absorption wavelength (λmax) of 337 nm. <Initiator (D)> NCI-730: ADEKA Corporation, product name: NCI-730, oxime ester photoradical generator PBG3057: TRONLY (Changzhou Strong Electronic New Materials Co., Ltd. (China)), product name: TR-PBG-3057, oxime ester photoradical generator <Radical curing component (E)> A-DPH-12E: Shin-Nakamura Chemical Co., Ltd., product name: A-DPH-12E, hexafunctional (meth)acrylate compound <Crosslinking agent (F)> Coronate L: manufactured by Tosoh Corporation, product name: Coronate L, isocyanate-based crosslinking agent <Silane Compound (G)> KBM3066: Shin-Etsu Chemical Co., Ltd., product name: KBM3066, silane coupling agent <UV absorber> SB107: Benzophenone-based UV absorber manufactured by Shipro Chemical Co., Ltd., trade name: SEESORB107, maximum absorption wavelength λmax = 350 nm, ε(380) = 22.4, ε(42 0)=1.6, ε(380) / ε(420)=14.0 SB707: Benzotriazole-based UV absorber manufactured by Shipro Chemical Co., Ltd., trade name: SEESORB707, maximum absorption wavelength λmax = 343 nm, ε(380) = 5.8, ε(4 20)=0. EU-1990: Manufactured by EUTEC, product name: EUSORB-1990, maximum absorption wavelength λmax=373nm, ε(380)=123.9, ε(420)=7.5, ε(380) / ε(420)=16.5

[0150] <Preparation of adhesive layer> Each of the pressure-sensitive adhesive compositions prepared above was applied to the release-treated surface of a release-treated polyethylene terephthalate separate film (trade name "PLR-382190" obtained from Lintec Corporation) using an applicator to a dry thickness of 5 μm, and then dried for 1 minute at 100°C. A pressure-sensitive adhesive layer (pressure-sensitive adhesive sheet) was then produced by irradiating the separate film with UV-A (wavelength 320-390 nm) using an ultraviolet irradiation device ("Electrodeless UV Lamp System H Bulb" manufactured by Fusion UV Systems) at an illuminance of 500 mW and an integrated light dose of 500 mJ.

[0151] <Measurement of absorbance of adhesive layer> Each of the resulting pressure-sensitive adhesive layers was applied to glass, and after peeling off the separate film, a cycloolefin polymer (COP) film (ZF-14, manufactured by Zeon Corporation) was applied to the pressure-sensitive adhesive layer to produce a laminate with a COP film / pressure-sensitive adhesive layer / glass structure. The resulting laminate was placed in a UV-2450 spectrophotometer (manufactured by Shimadzu Corporation) and its absorbance was measured in 1-nm steps over a wavelength range of 300 to 800 nm using the double-beam method. The absorbances A(300) at 300 nm, A(330) at 330 nm, A(350) at 350 nm, A(380) at 380 nm, and A(420) at 420 nm for the pressure-sensitive adhesive layer are shown in Table 2. The absorbance of the glass and the COP film at wavelengths of 300 nm, 330 nm, 350 nm, 380 nm and 420 nm were all 0. The results are shown in Table 3.

[0152] <Evaluation of bleeding resistance of adhesive layer> A separate film was further laminated on the surface of the obtained pressure-sensitive adhesive layer to obtain a pressure-sensitive adhesive layer with double-sided separate films. The obtained pressure-sensitive adhesive layer with double-sided separate films was stored in air at 23 to 25°C for one month. After storage, the pressure-sensitive adhesive layer with double-sided separate films was examined using a microscope to check for the presence or absence of crystalline precipitation of the compound within the surface. If no crystalline precipitation was observed, it was marked as "○", and if crystalline precipitation was observed, it was marked as "×". The evaluation results are shown in Table 2.

[0153] [Table 2]

[0154] The pressure-sensitive adhesive compositions of the examples exhibited absorbances of 0.6 or more at wavelengths of 300 nm, 330 nm, 350 nm, and 380 nm, demonstrating good ultraviolet absorber performance. Furthermore, the absorbance at a wavelength of 420 nm was less than 0.10 (more preferably less than 0.01), demonstrating high transmittance. Furthermore, the pressure-sensitive adhesive compositions of the present invention exhibited good bleeding resistance without crystal precipitation.

[0155] The pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition of the present invention exhibits high absorbance at wavelengths of around 300 nm to 380 nm, while transmitting light at a wavelength of 420 nm, thereby providing good ultraviolet absorption performance without impairing the color expression of a display device.In addition, the pressure-sensitive adhesive layer also has good bleeding resistance. The pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition of the present invention has sufficient ultraviolet absorbing performance and good bleeding resistance even when it is a thin layer having a thickness of less than 12 μm. [Industrial Applicability]

[0156] The pressure-sensitive adhesive composition of the present invention and an optical film with a pressure-sensitive adhesive layer comprising a pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition are suitably used in liquid crystal panels and liquid crystal displays. [Explanation of symbols]

[0157] 1. Pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition of the present invention 1a Adhesive layer 2 Release film 10 Laminate 10A, 10B Optical film with adhesive layer 10C, 10D Optical laminate 3, 6 Protective film 4, 7 Adhesive layer 5. Polarizing film 8. Retardation film 30 Light-emitting element 40 Optical Film 70, 50a 1 / 4 wavelength retardation layer 60 Adhesive layer or pressure sensitive adhesive layer 50 1 / 2 wavelength retardation layer 80 Positive C Layer 100 Polarizer 110 Phase contrast film.

Claims

1. Resin (A), A light-selective absorption compound (B) that exhibits a maximum absorption at a wavelength of 360 nm or more and satisfies the following formulas (1) and (2): At least one selected from a monomer (C-1) having a polymerizable group in the molecule and exhibiting a maximum absorption at a wavelength of 300 nm or more and less than 360 nm and a resin (C-2) exhibiting a maximum absorption at a wavelength of 300 nm or more and less than 360 nm A pressure-sensitive adhesive composition comprising: ε(380)≧25 (1) ε(380) / ε(420)≧20 (2) [In formulas (1) and (2), ε(380) represents the gram absorption coefficient of the light-selective absorbing compound (B) at a wavelength of 380 nm, and ε(420) represents the gram absorption coefficient of the light-selective absorbing compound (B) at a wavelength of 420 nm. The unit of the gram absorption coefficient is L / (g cm)]

2. The pressure-sensitive adhesive composition according to claim 1, further comprising an initiator (D).

3. The pressure-sensitive adhesive composition according to claim 2, wherein the initiator (D) is a radical generator.

4. The pressure-sensitive adhesive composition according to claim 2 or 3, wherein the initiator (D) is a photoradical generator.

5. The pressure-sensitive adhesive composition according to any one of claims 2 to 4, wherein the initiator (D) is an oxime ester-based photoradical generator.

6. The pressure-sensitive adhesive composition according to any one of claims 1 to 5, further comprising a radically curable component (E).

7. The pressure-sensitive adhesive composition according to claim 6 , wherein the radical-curable component (E) comprises a (meth)acrylate compound.

8. The pressure-sensitive adhesive composition according to claim 6 or 7, wherein the radical-curable component (E) comprises a polyfunctional (meth)acrylate compound.

9. The pressure-sensitive adhesive composition according to any one of claims 1 to 8, further comprising a crosslinking agent (F).

10. The pressure-sensitive adhesive composition according to claim 9, wherein the crosslinking agent (F) is an isocyanate-based crosslinking agent.

11. The pressure-sensitive adhesive composition according to any one of claims 1 to 10, wherein the resin (A) has a glass transition temperature of 40°C or lower.

12. The pressure-sensitive adhesive composition according to claim 11, wherein the resin (A) having a glass transition temperature of 40°C or lower is a (meth)acrylic resin.

13. A pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition according to any one of claims 1 to 12.

14. The pressure-sensitive adhesive layer according to claim 13 , which satisfies the following formula (3): A(380)≧0.6 (3) [In formula (3), A(380) represents absorbance at a wavelength of 380 nm.]

15. The pressure-sensitive adhesive layer according to claim 14 , further satisfying the following formula (4): A(380) / A(420)≧5 (4) [In formula (4), A(380) represents the absorbance at a wavelength of 380 nm, and A(420) represents the absorbance at a wavelength of 420 nm.]

16. The pressure-sensitive adhesive layer according to any one of claims 13 to 15, wherein the thickness of the pressure-sensitive adhesive layer is 10 µm or less.

17. An optical film with a pressure-sensitive adhesive layer, comprising the pressure-sensitive adhesive layer according to any one of claims 13 to 16 and an optical film layered on at least one surface of the pressure-sensitive adhesive layer.

18. The pressure-sensitive adhesive layer-attached optical film according to claim 17, wherein the optical film is a polarizing plate.

19. An image display device comprising the pressure-sensitive adhesive layer-attached optical film according to claim 17 or 18.

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