Resin and Adhesive Composition

Abstract

To provide a resin that can suppress photo-degradation of an organic EL light emitting element and a liquid crystal retardation film, an adhesive composition containing the resin, an adhesive layer formed from the adhesive composition, and an optical laminate in which the adhesive layers are laminated.SOLUTION: The present invention provides a resin (A) containing a structural unit having an indole structure. The resin (A) is a resin containing a structural unit having an indole structure in a side chain, preferably; and it has a glass transition temperature of 40°C or less, preferably. The resin (A) is a resin satisfying formula (1), preferably. ε(405)≥0.02 (1) [In formula (1), ε(405) is a gram extinction coefficient of the resin (A) at wavelength 405 nm. The gram extinction coefficient is expressed in a unit of L / (g cm)].SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to an optical laminate in which a resin, an adhesive composition containing the resin, and an adhesive layer formed from the adhesive composition are laminated.

Background Art

[0002] In display devices (FPD: flat panel display) such as organic electroluminescence displays (organic EL display devices) and liquid crystal display devices, various members such as display elements such as organic EL elements and liquid crystal cells, and optical films such as polarizing plates are used. Among these members, since organic EL light-emitting elements and liquid crystal compounds are organic substances, deterioration due to ultraviolet rays (UV) has been likely to be a problem. Furthermore, it has been clarified that liquid crystal-based retardation films and organic EL light-emitting elements formed by aligning and photocuring polymerizable liquid crystal compounds tend to deteriorate not only due to ultraviolet rays but also in short-wavelength visible light. In order to solve the above problems, it is known to provide a layer containing a compound that absorbs light of short-wavelength visible light. For example, Patent Document 1 describes a polarizing plate with an adhesive layer formed from an adhesive composition containing a copolymer composed of n-butyl acrylate, 2-hydroxyethyl acrylate, and N,N-dimethylacrylamide, and an indole-based ultraviolet absorber.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, when an adhesive layer containing the ultraviolet absorber described in Patent Document 1 is used as an optical laminate, it is possible to suppress deterioration caused by ultraviolet rays and short-wavelength visible light. However, it has been found that another problem occurs in that the optical properties are impaired due to the migration of the ultraviolet absorber to other layers. In particular, in a laminate with a liquid crystal retardation film, it has been found that the decrease in optical properties (change in retardation value) due to the migration of the ultraviolet absorber to other layers becomes significant.

Means for Solving the Problems

[0005] The present invention includes the following inventions. [1] A resin (A) containing a structural unit having an indole structure. [2] The resin according to [1], wherein the resin (A) has a glass transition temperature of 40°C or lower. [3] The resin according to [1] or [2], wherein the resin (A) satisfies the following formula (1). ε(405)≧ 0.02 (1) [In formula (1), ε(405) represents the gram extinction coefficient of the resin (A) at a wavelength of 405 nm. The unit of the gram extinction coefficient is L / (g·cm).] [4] The resin according to any one of [1] to [3], wherein the resin (A) satisfies the following formula (2). ε(405) / ε(440)≧ 5 (2) [In formula (2), ε(405) represents the gram extinction coefficient of the resin (A) at a wavelength of 405 nm, and ε(440) represents the gram extinction coefficient of the resin at a wavelength of 440 nm.] [5] The resin according to any one of [1] to [4], wherein the resin (A) is a resin containing a structural unit having an indole structure in the side chain. [6] The resin according to [5], wherein the structural unit having an indole structure in the side chain is a structural unit derived from a light-selective absorption compound having a polymerizable group and an indole structure. [7] The resin according to [6], wherein the light-selective absorption compound having a polymerizable group and an indole structure is a compound that satisfies the following formula (1-a). ε(405)≧ 5 (1-a) [In formula (1-a), ε(405) represents the gram extinction coefficient of a compound having a polymerizable group and an indole structure at a wavelength of 405 nm. The unit of the gram extinction coefficient is L / (g·cm).] [8] The resin according to [7], wherein the light-selective absorbing compound having a polymerizable group and an indole structure is a compound satisfying the following formula (2-a). ε(405) / ε(440) ≧ 10 (2-a) [In formula (2-a), ε(405) represents the gram extinction coefficient of a compound having a polymerizable group and an indole structure at a wavelength of 405 nm, and ε(440) represents the gram extinction coefficient of a compound having a polymerizable group and an indole structure at a wavelength of 440 nm.] [9] The resin according to [5], wherein the structural unit having an indole structure in the side chain is a structural unit derived from the compound represented by formula (I) or a structural unit derived from the compound represented by formula (II). TIFF0007715483000001.tif5395[In formula (I), R 1 , R 2 , R 3 , R 4 , R 5 and R 6 each independently represent a hydrogen atom, a heterocyclic group, a halogen atom, a nitro group, a cyano group, a hydroxy group, a carboxy group, an optionally substituted aliphatic hydrocarbon group having 1 to 25 carbon atoms or an optionally substituted aromatic hydrocarbon group having 6 to 18 carbon atoms, and -CH2- contained in the aliphatic hydrocarbon group or aromatic hydrocarbon group may be substituted with -NR 1A -, -SO2-, -CO-, -O-, -S- or -CF2-. R 1A represents a hydrogen atom, an alkyl group having 1 to 25 carbon atoms or an aromatic hydrocarbon group having 6 to 18 carbon atoms. E 1 represents an electron-withdrawing group. Z represents a linking group. A represents a polymerizable group. In formula (II), R 12 and R 17each independently represents a hydrogen atom, a heterocyclic group, a halogen atom, a nitro group, a cyano group, a hydroxy group, a carboxy group, an aliphatic hydrocarbon group having 1 to 25 carbon atoms which may have a substituent, or an aromatic hydrocarbon group having 6 to 18 carbon atoms which may have a substituent, and -CH2- contained in the aliphatic hydrocarbon group or aromatic hydrocarbon group may be substituted with -NR 11A -, -SO2-, -CO-, -O-, -S- or -CF2-. R 11 、R 13 、R 14 、R 15 and R 16 each independently represents a hydrogen atom, a heterocyclic group, a halogen atom, a nitro group, a cyano group, a hydroxy group, a carboxy group, a group containing a polymerizable group, an aliphatic hydrocarbon group having 1 to 25 carbon atoms which may have a substituent, or an aromatic hydrocarbon group having 6 to 18 carbon atoms which may have a substituent, and -CH2- contained in the aliphatic hydrocarbon group or aromatic hydrocarbon group may be substituted with -NR 12A -, -SO2-, -CO-, -O-, -S- or -CF2-. However, among R 11 、R 13 、R 14 、R 15 and R 16 at least one represents a group containing a polymerizable group. R 11A and R 12A each independently represents a sulfur atom, an alkyl group having 1 to 25 carbon atoms or an aromatic hydrocarbon group having 6 to 18 carbon atoms. E 11 represents an electron-withdrawing group.

[10] The resin according to [9], wherein R 2 is a phenyl group.

[11] The resin according to [9], wherein the compound represented by formula (I) is the compound represented by formula (III). TIFF000771548,300,002.tif4563[R 1 、R 3 、R 4 、R 5 、R 6 and E 1 represent the same meaning as described above. R 7 represents a hydrogen atom, a methyl group or a phenyl group. Z 1 represents an alkanediyl group having 1 to 12 carbon atoms, a divalent aromatic hydrocarbon group having 6 to 18 carbon atoms, -O-R 2A -*1, -S-R 2B -*1 or -NR 1D -R 2C -*1. Z 2 represents a single bond, *2-CO-O-, *2-O-CO-, *2-S(=O)2-, *2-O-SO2-, *2-CO-NR 1B -, *2-NR 1C -CO-, *2-R 2D O-P(=O)-OR 2E -, *2-NR 1E -CO-O-, *2-O-CO-NR 1F -, *2-(OR 2F ) s1 -, *2-CO-S-, *2-S-CO- or a perfluoroalkanediyl group having 1 to 4 carbon atoms. R 1B , R 1C、 R 1D R 1E and R 1F each independently represent a hydrogen atom or an alkyl group having 1 to 6 carbon atoms. R 2A , R 2B R 2C R 2D R 2E and R 2F each independently represent a divalent hydrocarbon group having 1 to 18 carbon atoms. *1 represents a bond to Z 2 . *2 represents a bond to Z 1 . The resin (A) according to any one of [1] to

[11] , further having at least one structural unit selected from the structural units described in the following Group A. Group A: Structural units derived from (meth)acrylate esters, structural units derived from styrene monomers, structural units derived from vinyl monomers, structural units derived from epoxy compounds, structural units represented by formula (a), structural units represented by formula (b), and structural units represented by formula (c) TIFF0007715483000003.tif35162[wherein, R a1 represents a divalent hydrocarbon group. R b1 and R b2 each independently represent a hydrogen atom or a hydrocarbon group. R c1 and R c2 each independently represent a divalent hydrocarbon group.]

[13] The resin according to

[12] , wherein the content of at least one structural unit selected from the structural units described in Group A is 50% by mass or more based on all the structural units of the resin (A).

[14] An adhesive composition containing the resin according to any one of [1] to

[13] .

[15] The adhesive composition according to

[14] , further containing a crosslinking agent (B).

[16] An adhesive layer formed from the adhesive composition according to

[14] or

[15] .

[17] The adhesive layer according to

[16] , which satisfies the following formula (3). A(405) ≧ 0.5 (3) [In formula (3), A(405) represents the absorbance at a wavelength of 405 nm.]

[18] The adhesive layer according to

[17] , which further satisfies the following formula (4). A(405) / A(440) ≧ 5 (4) [In formula (4), A(405) represents the absorbance at a wavelength of 405 nm, and A(440) represents the absorbance at a wavelength of 440 nm.]

[19] An optical laminate in which an optical film is laminated on at least one surface of the adhesive layer according to any one of

[16] to

[18] .

[20] The optical laminate according to

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

[21] An image display device including the optical laminate according to

[20] . A compound represented by formula (I) or formula (IV). TIFF0007715483000004.tif5297[In formula (I), R 1 , R 2 , R 3 , R 4 , R 5 and R 6 each independently represents a hydrogen atom, a heterocyclic group, a halogen atom, a nitro group, a cyano group, a hydroxy group, a carboxy group, an optionally substituted aliphatic hydrocarbon group having 1 to 25 carbon atoms or an optionally substituted aromatic hydrocarbon group having 6 to 18 carbon atoms, and -CH2- contained in the aliphatic hydrocarbon group or aromatic hydrocarbon group may be substituted with -NR 1A -, -SO2-, -CO-, -O-, -S- or -CF2-. R 1A represents a hydrogen atom, an alkyl group having 1 to 25 carbon atoms or an aromatic hydrocarbon group having 6 to 18 carbon atoms. E 1 represents an electron-withdrawing group. Z represents a linking group. A represents a polymerizable group. In formula (IV), R 12 and R 17 each independently represents a hydrogen atom, a heterocyclic group, a halogen atom, a nitro group, a cyano group, a hydroxy group, a carboxy group, an optionally substituted aliphatic hydrocarbon group having 1 to 25 carbon atoms or an optionally substituted aromatic hydrocarbon group having 6 to 18 carbon atoms, and -CH2- contained in the aliphatic hydrocarbon group or aromatic hydrocarbon group may be substituted with -NR 11A -, -SO2-, -CO-, -O-, -S- or -CF2-. R 11 , R 13 , R 14 , R 15 and R 16Each independently represents a hydrogen atom, a heterocyclic group, a halogen atom, a nitro group, a cyano group, a hydroxy group, a carboxy group, a group containing a polymerizable group, an optionally substituted aliphatic hydrocarbon group having 1 to 25 carbon atoms or an optionally substituted aromatic hydrocarbon group having 6 to 18 carbon atoms, and -CH2- contained in the aliphatic hydrocarbon group or aromatic hydrocarbon group may be substituted with -NR 12A -, -SO2-, -CO-, -O-, -S- or -CF2-. However, R 13 , R 14 , R 15 and R 16 Among them, at least one represents a group containing a polymerizable group. R 11A and R 12A Each independently represents a sulfur atom, an alkyl group having 1 to 25 carbon atoms or an aromatic hydrocarbon group having 6 to 18 carbon atoms. E 11 represents an electron-withdrawing group.]

[23] The compound according to

[22] , wherein R 2 is a phenyl group.

[24] The compound according to

[22] , wherein the compound represented by the formula (I) is the compound represented by the formula (III). TIFF0007715483000005.tif4563[R 1 , R 3 , R 4 , R 5 , R 6 and E 1 have the same meanings as described above. R 7 represents a hydrogen atom, a cyano group, a methyl group or a phenyl group. Z 1 represents an alkanediyl group having 1 to 12 carbon atoms, a divalent aromatic hydrocarbon group having 6 to 18 carbon atoms, -O-R 2A -*1, -S-R 2B -*1 or -NR 1D -R 2C -*1. Z 2 is a single bond, *2-CO-O-, *2-O-CO-, *2-S(=O)2-, *2-O-SO2-, *2-CO-NR 1B -, *2-NR1C -CO-, *2-R 2D O-P(=O)-OR 2E -*, *2-NR 1E -CO-O-, *2-O-CO-NR 1F -*, *2-(OR 2F ) s1 -*, *2-CO-S-, *2-S-CO- or a perfluoroalkanediyl group having 1 to 4 carbon atoms. R 1B , R 1C、 R 1D , R 1E and R 1F each independently represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms. R 2A , R 2B , R 2C , R 2D , R 2E and R 2F each independently represents a divalent hydrocarbon group having 1 to 18 carbon atoms. *1 represents a bond to Z 2 . *2 represents a bond to Z 1 .

[25] E 1 is the compound according to any one of

[22] to

[24] wherein 1 is a cyano group.

Advantages of the Invention

[0006] The present invention provides an adhesive layer capable of suppressing deterioration of an organic EL light-emitting element and a liquid crystal retardation film, and an adhesive composition for forming the adhesive layer. Further, a resin capable of forming an adhesive composition capable of favorably suppressing deterioration of an organic EL light-emitting element and a retardation film is provided.

Brief Description of the Drawings

[0007]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Embodiments for Carrying Out the Invention

[0008] <Adhesive Composition> The adhesive composition of the present invention contains a resin (A) containing a structural unit having an indole structure. The adhesive composition of the present invention may further contain a crosslinking agent (B), a silane compound (D), an antistatic agent, and the like.

[0009] <Resin (A)> The resin (A) of the present invention is a resin containing a structural unit having an indole structure, and preferably a resin containing a structural unit derived from an optical selective absorption compound having an indole structure.

[0010] The glass transition temperature (Tg) of the resin (A) is preferably 40 ° C or lower, more preferably 20 ° C or lower, still more preferably 10 ° C or lower, and particularly preferably 0 ° C or lower. Further, the glass transition temperature of the resin (A) is usually -80 ° C or higher, preferably -60 ° C or higher, and more preferably -50 ° C or higher. When the glass transition temperature of the resin (A) is 40 ° C or lower, it is advantageous for improving the adhesion of the adhesive layer formed from the adhesive composition containing the resin (A) to the adherend. Further, when the glass transition temperature of the resin (A) is -80 ° C or higher, it is advantageous for improving the durability of the adhesive layer formed from the adhesive composition containing the resin (A). The glass transition temperature can be measured by a differential scanning calorimeter (DSC).

[0011] The resin (A) is preferably a resin that satisfies the following formula (1). ε(405)≧ 0.02 (1) [In formula (1), ε(405) represents the gram extinction coefficient of the resin at a wavelength of 405 nm. The unit of the gram extinction coefficient is L / (g·cm).] Incidentally, the gram absorptivity coefficient of the resin (A) can be measured by the method described in the examples.

[0012] The larger the value of ε(405) in the resin (A), the easier it is to absorb light with a wavelength of 405 nm. The value of ε(405) is preferably 0.02 L / (g·cm) or more, more preferably 0.1 L / (g·cm) or more, even more preferably 0.2 L / (g·cm) or more, and usually 10 L / (g·cm) or less. When the pressure-sensitive adhesive composition containing the resin (A) is applied to a display device such as an organic EL display device or a liquid crystal display device, if ε(405) of the resin (A) is 0.02 L / (g·cm) or more, the absorption performance of visible light near 400 nm is good, so that deterioration due to visible light of a retardation film or an organic EL light-emitting element used in a display device such as an organic EL display device or a liquid crystal display device can be suppressed.

[0013] The resin (A) preferably satisfies the following formula (2). ε(405) / ε(440)≧ 5 (2) [In formula (2), ε(405) represents the gram absorptivity coefficient of the resin at a wavelength of 405 nm, and ε(440) represents the gram absorptivity coefficient of the resin at a wavelength of 440 nm.] The larger the value of ε(405) / ε(440) of the resin (A), the more selectively it can absorb light with a wavelength near 400 nm. The value of ε(405) / ε(440) is preferably 5 or more, more preferably 10 or more, and even more preferably 30 or more. When ε(405) / ε(440) of the resin (A) is 5 or more, when the pressure-sensitive adhesive composition containing the resin (A) is applied to a display device such as an organic EL display device or a liquid crystal display device, it is possible to absorb light near 400 nm and suppress light deterioration of the retardation film without hindering the color expression of the display device.

[0014] The resin (A) may contain a structural unit having an indole structure in the main chain or a structural unit having an indole structure in the side chain. The resin (A) preferably contains a structural unit having an indole structure in the side chain.

[0015] The structural unit having an indole structure in the side chain is not particularly limited, but is preferably a structural unit derived from a compound having a polymerizable group and an indole structure. The structural unit derived from a compound having a polymerizable group and an indole structure is preferably a structural unit derived from a photoselective absorption compound having a polymerizable group and an indole structure.

[0016] The photoselective absorption compound having a polymerizable group and an indole structure preferably satisfies the following formula (1-a), and more preferably satisfies formula (2-a). ε(405)≧ 5 (1-a) [In formula (1-a), ε(405) represents the gram extinction coefficient of the compound having a polymerizable group and an indole structure at a wavelength of 405 nm. The unit of the gram extinction coefficient is L / (g·cm).] ε(405) / ε(440)≧ 10 (2-a) [In formula (2-a), ε(405) represents the gram extinction coefficient of the compound having a polymerizable group and an indole structure at a wavelength of 405 nm, and ε(440) represents the gram extinction coefficient of the compound having a polymerizable group and an indole structure at a wavelength of 440 nm.]

[0017] For the compound having a polymerizable group and an indole structure, the value of ε(405) is preferably 5 L / (g·cm) or more, more preferably 10 L / (g·cm) or more, still more preferably 20 L / (g·cm) or more, even more preferably 30 L / (g·cm) or more, and usually 500 L / (g·cm) or less. The larger the value of ε(405) of the compound, the easier it is to absorb light at a wavelength of 405 nm, and the easier it is to exhibit a function of suppressing deterioration by ultraviolet rays or short-wavelength visible light. A compound having a coincidence group and an indole structure preferably has a value of ε(405) / ε(440) of 10 or more, more preferably 15 or more. The larger the value of ε(405) / ε(440), the more it can absorb light near 405 nm and suppress the light deterioration of display devices such as a retardation film and an organic EL element without inhibiting the color expression of the display device.

[0018] The structural unit having an indole structure in the side chain is preferably a structural unit derived from the compound represented by the formula (I) or a structural unit derived from the compound represented by the formula (II), and more preferably a structural unit derived from the compound represented by the formula (I). TIFF0007715483000006.tif5499[In the formula (I), R 1 、R 2 、R 3 、R 4 、R 5 and R 6 each independently represents a hydrogen atom, a heterocyclic group, a halogen atom, a nitro group, a cyano group, a hydroxy group, a carboxy group, an aliphatic hydrocarbon group having 1 to 25 carbon atoms which may have a substituent, or an aromatic hydrocarbon group having 6 to 18 carbon atoms which may have a substituent, and -CH2- contained in the aliphatic hydrocarbon group or aromatic hydrocarbon group may be substituted with -NR 1A -, -SO2-, -CO-, -O-, -S- or -CF2-. R 1A represents a hydrogen atom, an alkyl group having 1 to 25 carbon atoms or an aromatic hydrocarbon group having 6 to 18 carbon atoms. E 1 represents an electron-withdrawing group. Z represents a linking group. A represents a polymerizable group. In the formula (II), R 12 and R 17Each independently represents a hydrogen atom, a heterocyclic group, a halogen atom, a nitro group, a cyano group, a hydroxy group, a carboxy group, an aliphatic hydrocarbon group having 1 to 25 carbon atoms which may have a substituent, or an aromatic hydrocarbon group having 6 to 18 carbon atoms which may have a substituent, and -CH2- contained in the aliphatic hydrocarbon group or aromatic hydrocarbon group may be substituted with -NR 11A -, -SO2-, -CO-, -O-, -S- or -CF2-. R 11 、R 13 、R 14 、R 15 and R 16 Each independently represents a hydrogen atom, a heterocyclic group, a halogen atom, a nitro group, a cyano group, a hydroxy group, a carboxy group, a group containing a polymerizable group, an aliphatic hydrocarbon group having 1 to 25 carbon atoms which may have a substituent, or an aromatic hydrocarbon group having 6 to 18 carbon atoms which may have a substituent, and -CH2- contained in the aliphatic hydrocarbon group or aromatic hydrocarbon group may be substituted with -NR 12A -, -SO2-, -CO-, -O-, -S- or -CF2-. However, at least one of R 11 、R 13 、R 14 、R 15 and R 16 represents a group containing a polymerizable group. R 11A and R 12A Each independently represents an elemental atom, an alkyl group having 1 to 25 carbon atoms or an aromatic hydrocarbon group having 6 to 18 carbon atoms. E 11 represents an electron-withdrawing group.

[0019] E 1 and E 11 Examples of the electron-withdrawing group represented by include a cyano group, a nitro group, a halogen atom, an alkyl group substituted with a halogen atom, a group represented by formula (I-1), and the like. TIFF0007715483000007.tif1259[wherein, R 111represents a hydrogen atom or a hydrocarbon group having 1 to 25 carbon atoms, and at least one of the methylene groups contained in the alkyl group may be substituted with an oxygen atom. X 1 represents -CO-*3, -COO-*3, -CS-*3, -CSS-*3, -CSNR 112 -*3, -CONR 113 -*3, -CNR 114 -*3 or -SO2-*3. R 112 、R 113 and R 114 each independently represents a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or a phenyl group. *3 represents a bond with R 111 。 * represents a bond with a carbon atom.

[0020] Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. Examples of the alkyl group substituted with a halogen atom include halogenated alkyl groups such as a monofluoromethyl group, a monofluoroethyl group, a monochloromethyl group, a monochloroethyl group, a monobromomethyl group, a monobromoethyl group, a monoiodomethyl group, a monoiodoethyl group, a difluoromethyl group, a difluoroethyl group, a dichloromethyl group, a dichloroethyl group, a dibromomethyl group, a dibromoethyl group, a diiodomethyl group, a diiodoethyl group, a trifluoromethyl group, a trichloromethyl group, a tribromomethyl group, and a triiodomethyl group. The number of carbon atoms of the alkyl group substituted with a halogen atom is usually 1 to 25.

[0021] R 111Examples of the hydrocarbon group having 1 to 25 carbon atoms represented by the formula (I) include a linear hydrocarbon group having 1 to 25 carbon atoms, such as a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a tert-butyl group, a sec-butyl group, an n-pentyl group, an isopentyl group, an n-hexyl group, an isohexyl group, an n-octyl group, an isooctyl group, an n-nonyl group, an isononyl group, an n-decyl group, an isodecyl group, an n-dodecyl group, an isododecyl group, an undecyl group, a myristyl group, a cetyl group, and a stearyl group. or branched alkyl groups: cycloalkyl groups having 3 to 25 carbon atoms such as a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, or a cyclohexyl group; cycloalkylalkyl groups having 4 to 25 carbon atoms such as a cyclopropylmethyl group or a cyclohexylmethyl group; aryl groups having 6 to 25 carbon atoms such as a phenyl group, a naphthyl group, an anthracenyl group, or a biphenyl group; and aralkyl groups having 7 to 25 carbon atoms such as a benzyl group, a phenylethyl group, a naphthylmethyl group, or a phenyl group.

[0022] R 112 , R 113 and R 114 Examples of the alkyl group having 1 to 6 carbon atoms represented by the formula (I) include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a tert-butyl group, and a sec-butyl group.

[0023] The linking group represented by Z is not particularly limited as long as it is a divalent linking group.

[0024] The polymerizable group represented by A is not particularly limited. For example, it may be a cationically polymerizable group, an anionically polymerizable group, or a radically polymerizable group. More specific examples include alkynyl groups such as an ethynyl group; an epoxy group; an oxetanyl group; a vinyl ether group; an acrylonitrile group; a methacrylonitrile group; and ethylenically unsaturated groups such as a vinyl group, an α-methylvinyl group, an acryloyl group, a methacryloyl group, an allyl group, a styryl group, an acrylamide group, and a methacrylamide group.

[0025] R 1 ~R 6 , R 11 ~R17 Examples of the halogen atom represented by 17 include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. R 1 ~R 6 、R 11 ~R 17 Examples of the heterocyclic group represented by 17 include a group obtained by removing one hydrogen atom from a heterocycle. Specifically, aliphatic heterocyclic groups having 4 to 30 carbon atoms such as a pyrrolidine ring group, a pyrroline ring group, an imidazolidine ring group, an imidazoline ring group, an oxazoline ring group, a thiazoline ring group, a piperidine ring group, a morpholine ring group, a piperazine ring group, an indole ring group, an isoindole ring group, a quinoline ring group, a thiophene ring group, a pyrrole ring group, a thiazoline ring group, and a furan ring group, aromatic heterocyclic groups having 3 to 20 carbon atoms such as a pyridine ring group, a dioxane ring group, a morpholine ring group, a thiazine ring group, a triazole ring group, a tetrazole ring group, a dioxofuran ring group, a pyrazine ring group, a purine ring group, etc. may be mentioned. These heterocyclic groups may have a structure in which an unsaturated bond is hydrogenated, or may further have a structure in which a cyclic skeleton is condensed (for example, a benzimidazole ring or a benzimidazole ring), or a structure in which a hydrogen atom on the heterocycle is further substituted with a heterocyclic group, a halogen atom, a nitro group, a cyano group, a hydroxy group, a carboxy group, etc.

[0026] R 1 ~R 6 、R 11 ~R 17Examples of the aliphatic hydrocarbon group having 1 to 25 carbon atoms represented by include linear or branched alkyl groups having 1 to 25 carbon atoms such as methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, tert-butyl group, sec-butyl group, n-pentyl group, isopentyl group, n-hexyl group, isohexyl group, n-octyl group, isooctyl group, n-nonyl group, isononyl group, n-decyl group, isodecyl group, n-dodecyl group, isododecyl group, undecyl group, myristyl group, cetyl group, stearyl group; cycloalkyl groups having 3 to 25 carbon atoms such as cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group; cycloalkylalkyl groups having 4 to 25 carbon atoms such as cyclopropylmethyl group, cyclohexylmethyl group, etc. From the viewpoint of solubility, it is preferably a branched alkyl group having 3 to 25 carbon atoms such as 2-ethylhexyl group or 2-butyloctyl group. R 1 ~R 6 、R 11 ~R 17 Examples of the substituent that the aliphatic hydrocarbon group having 1 to 25 carbon atoms represented by may have include a heterocyclic group, a halogen atom, a nitro group, a cyano group, a hydroxy group, a carboxy group, an acetamido group, an amino group, an alkylamino group having 1 to 12 carbon atoms, etc. Examples of the heterocyclic group include the same ones as the heterocyclic group represented by R 1

[0027] R 1 ~R 6 、R 11 ~R 17 Examples of the aromatic hydrocarbon group having 6 to 18 carbon atoms represented by include aryl groups having 6 to 18 carbon atoms such as phenyl group, naphthyl group, anthracenyl group, biphenyl group, methylphenyl group; aralkyl groups having 7 to 18 carbon atoms such as benzyl group, phenylethyl group, naphthylmethyl group, phenoxy group, etc. R 1 ~R 6 、R 11 ~R 17Examples of the group in which -CH2- contained in the aromatic hydrocarbon group having 6 to 18 carbon atoms represented by is replaced with -SO2-, -CO-, -O-, -S- or -CF2- include aryl oxy groups such as a phenoxy group and a naphthyloxy group. From the viewpoint of wavelength selectivity, R 1 ~R 6 、R 11 ~R 17 The aromatic hydrocarbon group having 6 to 18 carbon atoms represented by is preferably an aralkyl group having 7 to 18 carbon atoms or an aryloxy group having 6 to 18 carbon atoms, and more preferably a benzyl group or an aryloxy group having 6 to 18 carbon atoms. R 1 ~R 6 、R 11 ~R 17 Examples of the substituent that the aromatic hydrocarbon group having 6 to 18 carbon atoms represented by may have include a heterocyclic group, a halogen atom, a nitro group, a cyano group, a hydroxy group, a carboxy group, an acetamido group, an amino group, an alkylamino group having 1 to 12 carbon atoms, and the like. Examples of the heterocyclic group include the same groups as the heterocyclic group represented by R 1 .

[0028] R 11 、R 13 、R 14 、R 15 And the group containing a polymerizable group represented by R 16 is not particularly limited as long as it has a polymerizable group at the terminal, and specifically, a group represented by the formula (I-2) can be mentioned. TIFF0007715483000008.tif964[In the formula (I-2), X 2 represents a polymerizable group. R 115 represents an alkanediyl group having 1 to 12 carbon atoms, and -CH2- contained in the alkanediyl group may be replaced with -O-, -CO-, -CS- or -NR 116 -. R 116 represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms. * represents a bond to a carbon atom or a nitrogen atom.]

[0029] X 2 Examples of the polymerizable group represented by [X] include the same groups as the polymerizable group represented by [A], and preferably ethylenically unsaturated groups such as vinyl group, α-methylvinyl group, acryloyl group, methacryloyl group, allyl group, styryl group, acrylamide group, and methacrylamide group. R 115 Examples of the alkanediyl group having 1 to 12 carbon atoms represented by [R] include methylene group, ethylene group, propane-1,3-diyl group, butane-1,4-diyl group, pentane-1,5-diyl group, hexane-1,6-diyl group, ethane-1,1-diyl group, propane-1,2-diyl group, butane-1,3-diyl group, 2-methylpropane-1,3-diyl group, 2-methylpropane-1,2-diyl group, pentane-1,4-diyl group, 2-methylbutane-1,4-diyl group, and the like. R 116 Examples of the alkyl group having 1 to 6 carbon atoms represented by [R] include the same groups as the alkyl group having 1 to 6 carbon atoms represented by [R]. 112

[0030] R 11 R 13 R 14 R 15 R 16 Among [R], [R], [R], [R], [R], and [R], at least one represents a group containing a polymerizable group. R 13 R 14 R 15 R 16 Preferably, at least one of [R], [R], [R], [R], and [R] is a group containing a polymerizable group, and more preferably, any one of [R], [R], [R], [R], or [R] is a group containing a polymerizable group. 13 R 14 R 15 R 16 or [R] is a group containing a polymerizable group.

[0031] R 2 is preferably an aromatic hydrocarbon group having 6 to 18 carbon atoms or a heterocyclic group, and more preferably an aromatic hydrocarbon group having 6 to 18 carbon atoms or an aromatic heterocyclic group having 3 to 20 carbon atoms. The polymerizable group represented by [A] is preferably an ethylenically unsaturated group. E 1 ​and E 11 is preferably a cyano group independently of each other.

[0032] The compound represented by formula (I) is preferably the compound represented by formula (III). TIFF0007715483000009.tif4563[R 1 , R 3 , R 4 , R 5 , R 6 and E 1 represent the same meaning as described above. R 7 represents a hydrogen atom, a cyano group, a methyl group or a phenyl group. Z 1 is an alkanediyl group having 1 to 12 carbon atoms, a divalent aromatic hydrocarbon group having 6 to 18 carbon atoms, -O-R 2A -*1, -S-R 2B -*1 or -NR 1D -R 2C -*1. Z 2 is a single bond, *2-CO-O-, *2-O-CO-, *2-S(=O)2-, *2-O-SO2-, *2-CO-NR 1B -, *2-NR 1C -CO-, *2-R 2D O-P(=O)-OR 2E -, *2-NR 1E -CO-O-, *2-O-CO-NR 1F -, *2-(OR 2F ) s1 -, *2-CO-S-, *2-S-CO- or a perfluoroalkanediyl group having 1 to 4 carbon atoms. R 1B , R 1C、 R 1D , R 1E and R 1F each independently represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms. R 2A , R 2B , R 2C , R 2D , R 2E and R 2FEach independently represents a divalent hydrocarbon group having 1 to 18 carbon atoms. *1 represents a bond with Z 2 *2 represents a bond with Z 1

[0033] Z 1 Examples of the alkanediyl group having 1 to 12 carbon atoms represented by are the same as those of the alkanediyl group having 1 to 12 carbon atoms represented by R 115 Z 1 Examples of the divalent aromatic hydrocarbon group having 6 to 18 carbon atoms represented by include a phenylene group, a naphthylene group, and the like.

[0034] R 1B R 1C、 R 1D R 1E R 1F Examples of the alkyl group having 1 to 6 carbon atoms represented by and R are the same as those of the alkyl group having 1 to 6 carbon atoms represented by R 112 R 2A R 2B R 2C R 2D R 2E R 2F Examples of the divalent hydrocarbon group having 1 to 18 carbon atoms represented by and R include alkanediyl groups having 1 to 18 carbon atoms such as a methylene group, an ethylene group, a propane-1,3-diyl group, a butane-1,4-diyl group, a pentane-1,5-diyl group, a hexane-1,6-diyl group, an ethane-1,1-diyl group, a propane-1,2-diyl group, a butane-1,3-diyl group, a 2-methylpropane-1,3-diyl group, a 2-methylpropane-1,2-diyl group, a pentane-1,4-diyl group, and a 2-methylbutane-1,4-diyl group; and divalent aromatic hydrocarbon groups having 6 to 18 carbon atoms such as a phenylene group and a naphthylene group.

[0035] Z 1 is -O-R 2A -*1 (more preferably R 2A ​​​is preferably an alkanediyl group having 1 to 8 carbon atoms, more preferably an alkanediyl group having 4 to 8 carbon atoms). Z 2 is *2-O-CO-, *2-O-SO2-, *2-NR 1C -CO- (more preferably R 1C is a hydrogen atom).

[0036] The compound represented by formula (II) is preferably the compound represented by formula (IV). TIFF0007715483000010.tif3550[R 11 、R 12 、R 13 、R 14 、R 15 、R 16 、R 17 and E 11 represent the same meaning as described above. However, among R 13 、R 14 、R 15 and R 16 at least one represents a group containing a polymerizable group.]

[0037] Examples of the compound represented by formula (I) include the compounds described below. TIFF0007715483000011.tif175163

[0038] TIFF0007715483000012.tif178161

[0039] TIFF0007715483000013.tif62156

[0040] TIFF0007715483000014.tif185165

[0041] TIFF0007715483000015.tif175163

[0042] TIFF0007715483000016.tif44170

[0043] TIFF0007715483000017.tif104150

[0044] TIFF0007715483000018.tif140131 TIFF0007715483000019.tif7889

[0045] Examples of the compound represented by formula (II) include the compounds shown below. TIFF0007715483000020.tif135158

[0046] TIFF0007715483000021.tif186167

[0047] TIFF0007715483000022.tif51160

[0048] TIFF0007715483000023.tif113162

[0049] TIFF0007715483000024.tif126148

[0050] TIFF0007715483000025.tif209137

[0051] TIFF0007715483000026.tif185150

[0052] The compound represented by formula (I) in which A is an ethylenically unsaturated group can be obtained, for example, by reacting a compound represented by formula (Ia) with a compound represented by formula (c1). TIFF0007715483000027.tif3965 [In formula (Ia), R 1 , R 2 , R 3 , R 4 , R 5 , R 6 and E 1 has the same meaning as above. Z in formula (c)3 represents a divalent linking group, A 1 represents an ethylenically polymerizable group.]

[0053] The amount of the compound represented by formula (c1) used is preferably 0.5 to 5 moles per mole of the compound represented by formula (Ia). The reaction between the compound represented by formula (Ia) and the compound represented by formula (c1) can be carried out using a known esterification reaction, but is preferably carried out in the presence of a base and a carbodiimide condensing agent. Examples of bases include triethylamine, diisopropylethylamine, pyridine, piperidine, pyrrolidine, proline, and N,N-dimethylaminopyridine. Examples of carbodiimide condensing agents include N,N-dicyclohexylcarbodiimide, N,N-diisopropylcarbodiimide, and 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride. The amount of the base used is preferably 0.001 to 0.5 mol per mol of the compound represented by formula (Ia). The amount of the carbodiimide condensing agent used is preferably 0.5 to 5 mol per mol of the compound represented by formula (Ia). The reaction between the compound represented by formula (Ia) and the compound represented by formula (c1) is preferably carried out in an organic solvent, such as toluene, acetonitrile, dichloromethane, or trichloromethane.

[0054] A polymerization inhibitor may be added to inhibit the reaction between ethylenically unsaturated groups contained in the compound represented by formula (c1). Examples of the polymerization inhibitor include 2,6-di-t-butyl-4-methylphenol (BHT) and 4-methoxyphenol.

[0055] The reaction between the compound represented by formula (Ia) and the compound represented by formula (c1) is carried out by mixing the compound represented by formula (Ia) and the compound represented by formula (c1). The reaction temperature of the compound represented by formula (Ia) and the compound represented by formula (c1) is preferably −20 to 120° C., and the reaction time is usually preferably 1 to 50 hours.

[0056] Examples of the compound represented by formula (Ia) include the compounds described below. TIFF0007715483000028.tif3029

[0057] Examples of the compound represented by formula (c1) include 4-hydroxybutyl acrylate, 2-hydroxyethyl acrylate, and the like.

[0058] The compound represented by formula (Ia) can be obtained by reacting the compound represented by formula (Ib) with the compound represented by formula (c2). TIFF0007715483000029.tif4077[wherein R 1 , R 2 , R 3 , R 4 , R 5 , R 6 and E 1 represent the same meanings as described above.]

[0059] The amount of the compound represented by formula (c2) used is preferably 0.5 to 5 moles per 1 mole of the compound represented by formula (Ib). The reaction between the compound represented by formula (Ib) and the compound represented by formula (c2) is preferably carried out in the presence of a base. Examples of the base include pyridine, pyrrolidine, piperidine, triethylamine, diisopropylethylamine, and the like. The amount of the base used is preferably 0.5 to 5 moles per 1 mole of the compound represented by formula (Ib). The reaction between the compound represented by formula (Ib) and the compound represented by formula (c2) is preferably carried out in an organic solvent. Examples of the organic solvent include acetonitrile, isopropanol, toluene, trichloromethane, dichloromethane, and the like. The reaction between the compound represented by formula (Ib) and the compound represented by (c2) is carried out by mixing the compound represented by formula (Ia) and the compound represented by (c1). The reaction temperature of the compound represented by the formula (Ia) and the compound represented by (c1) is preferably 0 to 120 °C, and the reaction time is usually preferably 1 to 50 hours.

[0060] The resin (A) may be a homopolymer of a structural unit having an indole structure, or may be a copolymer containing a structural unit having an indole structure and other structural units. The resin (A) is preferably a copolymer. Examples of the structural unit that the resin (A) may contain in addition to the structural unit having an indole structure include the structural units described in the following Group A. Group A: Structural units derived from (meth)acrylic acid esters, structural units derived from styrene monomers, structural units derived from vinyl monomers, structural units derived from epoxy compounds, structural units represented by the formula (a), structural units represented by the formula (b), and structural units represented by the formula (c) TIFF0007715483000030.tif34162[wherein, R a1 represents a divalent hydrocarbon group. R b1 and R b2 each independently represent a hydrogen atom or a hydrocarbon group. R c1 and R c2 each independently represent a divalent hydrocarbon group.]

[0061] Examples of the (meth)acrylic acid ester include linear alkyl esters of (meth)acrylic acid such as methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, n-butyl (meth)acrylate, n-pentyl (meth)acrylate, n-hexyl (meth)acrylate, n-heptyl (meth)acrylate, n-octyl (meth)acrylate, n-nonyl (meth)acrylate, n-decyl (meth)acrylate, n-dodecyl (meth)acrylate, lauryl (meth)acrylate, stearyl (meth)acrylate, etc.; (Meth)acrylic acid i-propyl, (meth)acrylic acid i-butyl, (meth)acrylic acid t-butyl, (meth)acrylic acid i-pentyl, (meth)acrylic acid i-hexyl, (meth)acrylic acid 2-ethylhexyl, (meth)acrylic acid i-octyl, (meth)acrylic acid i-nonyl, (meth)acrylic acid i-stearyl, (meth)acrylic acid i-amyl, and other branched alkyl esters of (meth)acrylic acid; (Meth)acrylic acid cyclohexyl, (meth)acrylic acid isobornyl, (meth)acrylic acid adamantyl, (meth)acrylic acid dicyclopentanyl, (meth)acrylic acid cyclododecyl, (meth)acrylic acid methylcyclohexyl, (meth)acrylic acid trimethylcyclohexyl, (meth)acrylic acid tert-butylcyclohexyl, α-ethoxyacrylic acid cyclohexyl, and other alicyclic skeleton-containing alkyl esters of (meth)acrylic acid; (Meth)acrylic acid phenyl and other aromatic ring skeleton-containing esters of (meth)acrylic acid; And the like can be mentioned.

[0062] Examples of the structural unit derived from the (meth)acrylic acid ester include substituted group-containing (meth)acrylic acid alkyl esters in which a substituent is introduced into the alkyl group in the (meth)acrylic acid alkyl ester. The substituent of the substituted group-containing (meth)acrylic acid alkyl ester is a group that substitutes the hydrogen atom of the alkyl group, and specific examples thereof include a phenyl group, an alkoxy group, and a phenoxy group. Specific examples of the substituted group-containing (meth)acrylic acid alkyl ester include (meth)acrylic acid 2-methoxyethyl, (meth)acrylic acid ethoxymethyl, (meth)acrylic acid phenoxyethyl, (meth)acrylic acid 2-(2-phenoxyethoxy)ethyl, (meth)acrylic acid phenoxydiethylene glycol, (meth)acrylic acid phenoxypoly(ethylene glycol), and the like.

[0063] These (meth)acrylic acid esters can be used alone, or a plurality of different ones can also be used.

[0064] The resin (A) of the present invention preferably contains a structural unit derived from a (meth)acrylic acid alkyl ester (a1) whose glass transition temperature Tg of the homopolymer is less than 0°C, and a structural unit derived from a (meth)acrylic acid alkyl ester (a2) whose Tg of the homopolymer is 0°C or higher. This is advantageous for enhancing the high-temperature durability of the pressure-sensitive adhesive layer. The Tg of the homopolymer of the (meth)acrylic acid alkyl ester can adopt literature values such as those in POLYMER HANDBOOK (Wiley-Interscience).

[0065] Specific examples of the (meth)acrylic acid alkyl ester (a1) include (meth)acrylic acid alkyl esters having about C2-C12 alkyl groups such as ethyl acrylate, n- and i-propyl acrylates, n- and i-butyl acrylates, n-pentyl acrylate, n- and i-hexyl acrylates, n-heptyl acrylate, n- and i-octyl acrylates, 2-ethylhexyl acrylate, n- and i-nonyl acrylates, n- and i-decyl acrylates, and n-dodecyl acrylate.

[0066] Only one kind of the (meth)acrylic acid alkyl ester (a1) may be used, or two or more kinds may be used in combination. Among them, n-butyl acrylate, n-octyl acrylate, 2-ethylhexyl acrylate, etc. are preferable from the viewpoints of followability and reworkability when laminated on an optical film.

[0067] 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.

[0068] (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, (meth)acrylic acid alkyl ester (a2) preferably contains methyl acrylate, cyclohexyl acrylate, isobornyl acrylate, etc., and more preferably contains methyl acrylate.

[0069] In addition, as the structural unit derived from (meth)acrylic acid ester, a structural unit derived from (meth)acrylic acid ester having a polar functional group is also included. Examples of the (meth)acrylic acid ester monomer having a polar functional group include (Meth)acrylic acid 1-hydroxymethyl, (meth)acrylic acid 1-hydroxyethyl, (meth)acrylic acid 1-hydroxyheptyl, (meth)acrylic acid 1-hydroxybutyl, (meth)acrylic acid 1-hydroxypentyl, (meth)acrylic acid 2-hydroxyethyl, (meth)acrylic acid 2-hydroxypropyl, (meth)acrylic acid 2-hydroxybutyl, (meth)acrylic acid 2-hydroxypentyl, (meth)acrylic acid 2-hydroxyhexyl, (meth)acrylic acid 3-hydroxypropyl, (meth)acrylic acid 3-hydroxybutyl, (meth)acrylic acid 3-hydroxypentyl, (meth)acrylic acid 3-hydroxyhexyl, (meth)acrylic acid 3-hydroxyheptyl, (meth)acrylic acid 4-hydroxybutyl, (meth)acrylic acid 4-hydroxypentyl, (meth)acrylic acid 4-hydroxyhexyl, (meth)acrylic acid 4-hydroxyheptyl, (meth)acrylic acid 4-hydroxyoctyl, (meth)acrylic acid 2-chloro-2-hydroxypropyl, (meth)acrylic acid 3-chloro-2-hydroxypropyl, (meth)acrylic acid 2-hydroxy-3-phenoxypropyl, (meth)acrylic acid 5-hydroxypentyl, (meth)acrylic acid 5-hydroxyhexyl, (meth)acrylic acid 5-hydroxyheptyl, (meth)acrylic acid 5-hydroxyoctyl, (meth)acrylic acid 5-hydroxynonyl, (meth)acrylic acid 6-hydroxyhexyl, (meth)acrylic acid 6-hydroxyheptyl, (meth)acrylic acid 6-hydroxyoctyl, (meth)acrylic acid 6-hydroxynonyl, (meth)acrylic acid 6-hydroxydecyl, (meth)acrylic acid 7-hydroxyheptyl, (meth)acrylic acid 7-hydroxyoctyl, (meth)acrylic acid 7-hydroxynonyl, (meth)acrylic acid 7-hydroxydecyl, (meth)acrylic acid 7-hydroxyundecyl, (meth)acrylic acid 8-hydroxyoctyl, (meth)acrylic acid 8-hydroxynonyl, (meth)acrylic acid 8-hydroxydecyl, (meth)acrylic acid 8-hydroxyundecyl, (meth)acrylic acid 8-hydroxy dodecyl, (meth)acrylic acid 9-hydroxynonyl, (meth)acrylic acid 9-hydroxydecyl, (meth)acrylic acid 9-hydroxyundecyl, (meth)acrylic acid 9-hydroxy dodecyl,(Meth)acrylic acid 9-hydroxytridecyl, (meth)acrylic acid 10-hydroxydecyl, (meth)acrylic acid 10-hydroxyundecyl, (meth)acrylic acid 10-hydroxydodecyl, acrylic acid 10-hydroxytridecyl, (meth)acrylic acid 10-hydroxytetradecyl, (meth)acrylic acid 11-hydroxyundecyl, (meth)acrylic acid 11-hydroxydodecyl, (meth)acrylic acid 11-hydroxytridecyl, (meth)acrylic acid 11-hydroxytetradecyl, (meth)acrylic acid 11-hydroxypentadecyl, (meth)acrylic acid 12-hydroxydodecyl, (meth)acrylic acid 12-hydroxytridecyl, (meth)acrylic acid 12-hydroxytetradecyl, (meth)acrylic acid 13-hydroxypentadecyl, (meth)acrylic acid 13-hydroxytetradecyl, (meth)acrylic acid 13-hydroxypentadecyl, (meth)acrylic acid 14-hydroxytetradecyl, (meth)acrylic acid 14-hydroxypentadecyl, (meth)acrylic acid 15-hydroxypentadecyl, (meth)acrylic acid 15-hydroxyheptadecyl and other alkyl (meth)acrylates having a hydroxy group are mentioned.

[0070] Styrene monomers include styrene; alkylstyrenes such as methylstyrene, dimethylstyrene, trimethylstyrene, ethylstyrene, diethylstyrene, triethylstyrene, propylstyrene, butylstyrene, hexylstyrene, heptylstyrene, octylstyrene; halogenated styrenes such as fluorostyrene, chlorostyrene, bromostyrene, dibromostyrene, iodostyrene; nitrostyrene; acetylstyrene; methoxystyrene; and divinylbenzene.

[0071] Examples of vinyl monomers include vinyl esters of fatty acids such as vinyl acetate, vinyl propionate, vinyl butyrate, vinyl 2-ethylhexanoate, vinyl laurate; vinyl halides such as vinyl chloride, vinyl bromide; vinylidene halides such as vinylidene chloride; nitrogen-containing heteroaromatic vinyls such as vinyl pyridine, vinyl pyrrolidone, vinyl carbazole; conjugated dienes such as butadiene, isoprene, chloroprene; and unsaturated nitriles such as acrylonitrile, methacrylonitrile.

[0072] An epoxy compound is a compound having an epoxy group in the molecule. The epoxy group may be an epoxy group bonded to an alicyclic ring such as an epoxycyclopentane structure or an epoxycyclohexane structure. Examples of epoxy compounds include 3,4-epoxycyclohexylmethyl 3,4-epoxycyclohexanecarboxylate, 3,4-epoxy-6-methylcyclohexylmethyl 3,4-epoxy-6-methylcyclohexanecarboxylate, ethylenebis(3,4-epoxycyclohexanecarboxylate), bis(3,4-epoxycyclohexylmethyl) adipate, bis(3,4-epoxy-6-methylcyclohexylmethyl) adipate, diethylene glycol bis(3,4-epoxycyclohexylmethyl ether), ethylene glycol bis(3,4-epoxycyclohexylmethyl ether), 2,3,14,15-diepoxy-7,11,18,21-tetraoxatrispiro[5.2.2.5.2.2]heneicosane, 3-(3,4-epoxycyclohexyl)-8,9-epoxy-1,5-dioxaspiro[5.5]undecane, 4-vinylcyclohexene dioxide, limonene dioxide, bis(2,3-epoxycyclopentyl) ether, dicyclopentadiene dioxide, 1,4-butanediol diglycidyl ether, 1,6-hexanediol diglycidyl ether, neopentyl glycol diglycidyl ether, trimethylolpropane triglycidyl ether, pentaerythritol tetraglycidyl ether, and the like.

[0073] The compound that leads to the structural unit represented by formula (a) can be synthesized, for example, by the reaction of a diisocyanate compound and a polyol. The compound that leads to the structural unit represented by formula (b) can be synthesized, for example, by reacting a silane halide or a silane having a hydroxy group. The compound that leads to the structural unit represented by formula (c) can be synthesized, for example, by the reaction of a polycarboxylic acid and a polyol.

[0074] The structural unit selected from the structural units described in Group A is preferably a structural unit derived from a (meth)acrylate ester. The structural unit derived from a (meth)acrylate ester is preferably a (meth)acrylate alkyl ester and a (meth)acrylate alkyl ester having a hydroxy group.

[0075] The resin (A) of the present invention may further contain another structural unit (which may be referred to as structural unit (aa)). Specifically, examples include a structural unit derived from a (meth)acrylamide-based monomer, a structural unit derived from a monomer having a carboxy group, a structural unit derived from a monomer having a heterocyclic group, a structural unit derived from a monomer having a substituted or unsubstituted amino group, and the like.

[0076] (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, N-(2-propoxyethyl)(meth)acrylamide, N-[2-(1-methylethoxy)ethyl](meth)acrylamide, N-[2-(1-methylpropoxy)ethyl](meth)acrylamide, N-[2-(2-methylpropoxy)ethyl](meth)acrylamide, N-(2-butoxyethyl)(meth)acrylamide, N-[2-(1,1-dimethylethoxy)ethyl](meth)acrylamide, etc. Among them, N-(methoxymethyl)acrylamide, N-(ethoxymethyl)acrylamide, N-(propoxymethyl)acrylamide, N-(butoxymethyl)acrylamide and N-(2-methylpropoxymethyl)acrylamide are preferred.

[0077] Examples of the monomer having a carboxy group include (meth)acrylic acid, carboxyalkyl (meth)acrylate (e.g., carboxyethyl (meth)acrylate, carboxypentyl (meth)acrylate), maleic acid, maleic anhydride, fumaric acid, crotonic acid, etc., and acrylic acid is preferable.

[0078] Examples of the monomer having a heterocyclic group include acryloylmorpholine, vinylcaprolactam, N-vinyl-2-pyrrolidone, vinylpyridine, tetrahydrofurfuryl (meth)acrylate, caprolactone-modified tetrahydrofurfuryl acrylate, 3,4-epoxycyclohexylmethyl (meth)acrylate, glycidyl (meth)acrylate, 2,5-dihydrofuran, etc.

[0079] Examples of the monomer having a substituted or unsubstituted amino group include aminoethyl (meth)acrylate, N,N-dimethylaminoethyl (meth)acrylate, dimethylaminopropyl (meth)acrylate, etc.

[0080] As the structural unit having an indole structure and the structural unit (aa) other than the structural unit selected from Group A, a monomer having a carboxy group is preferable.

[0081] The content of the structural unit having an indole structure is preferably 0.01 to 50 parts by mass, more preferably 0.1 to 20 parts by mass, and still more preferably 0.5 to 15 parts by mass with respect to 100 parts by mass of all the structural units contained in the resin (A). The content of at least one structural unit selected from the structural units described in Group A is preferably 50 parts by mass or more, more preferably 55 to 99.99 parts by mass, and still more preferably 60 to 85 parts by mass with respect to 100 parts by mass of all the structural units of the resin (A). When the resin (A) contains the structural unit (aa), it is preferably 20 parts by mass or less, more preferably 0.5 parts by mass or more and 15 parts by mass or less, still 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, based on 100 parts by mass of all the structural units of the resin (A).

[0082] When the resin (A) contains a structural unit derived from a (meth)acrylic acid alkyl ester having a hydroxy group, the content of the structural unit is preferably 20 parts by mass or less, more preferably 0.5 parts by mass or more and 15 parts by mass or less, still 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, based on 100 parts by mass of all the structural units of the resin (A). From the viewpoint of preventing the enhancement of the peel force of the separate film that can be laminated on the outer surface of the pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition, it is preferable that the monomer having an amino group is not substantially contained. Here, not substantially containing the monomer having an amino group means that the content of the structural unit derived from the monomer having an amino group is 0.1 part by mass or less in 100 parts by mass of all the constituent units constituting the resin (A).

[0083] From the viewpoint of the reactivity between the resin (A) and the crosslinking agent (B) described later, the resin (A) preferably contains a structural unit derived from a (meth)acrylic acid alkyl ester having a hydroxy group or a structural unit derived from a monomer having a carboxy group, and more preferably contains both a structural unit derived from a (meth)acrylic acid alkyl ester having a hydroxy group and a structural unit derived from a monomer having a carboxy group. As the (meth)acrylic acid alkyl ester having a hydroxy group, 2-hydroxyethyl acrylate, 3-hydroxypropyl acrylate, 4-hydroxybutyl acrylate, 5-hydroxypentyl acrylate, and 6-hydroxyhexyl acrylate are preferable. In particular, good durability can be obtained by using 2-hydroxyethyl acrylate, 4-hydroxybutyl acrylate, and 5-hydroxypentyl acrylate. As the monomer having a carboxy group, acrylic acid is preferably used.

[0084] The weight average molecular weight (Mw) of the resin (A) of the present invention is preferably from 300,000 to 2,500,000, more preferably from 500,000 to 2,000,000. When the weight average molecular weight is 300,000 or more, the durability of the pressure-sensitive adhesive layer in a high-temperature environment is improved, and defects such as peeling between the adherend and the pressure-sensitive adhesive layer and cohesive failure of the pressure-sensitive adhesive layer are easily suppressed. When the weight average molecular weight is 2,500,000 or less, it is advantageous from the viewpoint of coatability when processing the pressure-sensitive adhesive composition into, for example, a sheet form (coating on a substrate). 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 from 600,000 to 1,800,000, more preferably from 700,000 to 1,700,000, and still more preferably from 1,000,000 to 1,600,000. Further, the molecular weight distribution (Mw / Mn) represented by the ratio of the weight average molecular weight (Mw) to the number average molecular weight (Mn) is usually from 2 to 10, preferably from 3 to 8. The weight average molecular weight can be analyzed by gel permeation chromatography and is a value in terms of standard polystyrene.

[0085] When the resin (A) of the present invention is dissolved in ethyl acetate to form a solution having a concentration of 20% by mass, the viscosity at 25°C is preferably 20 Pa·s or less, more preferably from 0.1 to 15 Pa·s. When the viscosity is within this range, it is advantageous from the viewpoint of coatability when coating the pressure-sensitive adhesive composition on a substrate. The viscosity can be measured using a Brookfield viscometer.

[0086] The resin (A) of the present invention can be produced by known methods such as solution polymerization method, bulk polymerization method, suspension polymerization method, emulsion polymerization method, etc., and the solution polymerization method is particularly preferred. As the solution polymerization method, for example, a monomer having an indole structure, a monomer that introduces the structural unit described in Group A as needed, and an organic solvent are mixed, a thermal polymerization initiator is added under a nitrogen atmosphere, and the mixture is stirred at a temperature of 40 to 90°C, preferably about 50 to 80°C for about 3 to 15 hours. For reaction control, monomers and thermal polymerization initiators may be added continuously or intermittently during the polymerization. The monomers and thermal initiators may be in a state of being added to the organic solvent.

[0087] As the polymerization initiator, a thermal polymerization initiator, a photopolymerization initiator, etc. are used. Examples of the photopolymerization initiator include 4-(2-hydroxyethoxy)phenyl(2-hydroxy-2-propyl)ketone. Examples of the thermal polymerization initiator include azo compounds such as 2,2'-azobisisobutyronitrile, 2,2'-azobis(2-methylbutyronitrile), 1,1'-azobis(cyclohexane-1-carbonitrile), 2,2'-azobis(2,4-dimethylvaleronitrile), 2,2'-azobis(2,4-dimethyl-4-methoxyvaleronitrile), dimethyl-2,2'-azobis(2-methylpropionate), 2,2'-azobis(2-hydroxymethylpropionitrile); organic peroxides such as lauryl peroxide, t-butyl hydroperoxide, benzoyl peroxide, t-butyl peroxybenzoate, cumene hydroperoxide, diisopropyl peroxydicarbonate, dipropyl peroxydicarbonate, t-butyl peroxyneodecanoate, t-butyl peroxypivalate, (3,5,5-trimethylhexanoyl)peroxide; inorganic peroxides such as potassium persulfate, ammonium persulfate, hydrogen peroxide, etc. Further, a redox initiator using a peroxide and a reducing agent in combination can also be used.

[0088] The proportion of the polymerization initiator is about 0.001 to 5 parts by mass with respect to 100 parts by mass of the total amount of the monomers constituting the resin (A). The polymerization of the resin (A) may use a polymerization method by active energy rays (such as ultraviolet rays).

[0089] 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; ketones such as acetone, methyl ethyl ketone, and methyl isobutyl ketone.

[0090] The content of the resin (A) is usually 60% by mass to 99.99% by mass, preferably 70% by mass to 99.9% by mass, and more preferably 80% by mass to 99.7% by mass in 100% by mass of the solid content of the pressure-sensitive adhesive composition.

[0091] <Crosslinking agent (B)> The pressure-sensitive adhesive composition of the present invention can contain a crosslinking agent (B). Examples of the crosslinking agent (B) include isocyanate-based crosslinking agents, epoxy-based crosslinking agents, aziridine-based crosslinking agents, metal chelate-based crosslinking agents, etc. From the viewpoints of the pot life of the pressure-sensitive adhesive composition, the durability of the pressure-sensitive adhesive layer, the crosslinking speed, etc., it is preferably an isocyanate-based crosslinking agent.

[0092] As the isocyanate compound, a compound having at least two isocyanato groups (-NCO) in the molecule is preferable. For example, aliphatic isocyanate compounds (such as hexamethylene diisocyanate), alicyclic isocyanate compounds (such as isophorone diisocyanate, hydrogenated diphenylmethane diisocyanate, hydrogenated xylylene diisocyanate), aromatic isocyanate compounds (such as tolylene diisocyanate, xylylene diisocyanate, diphenylmethane diisocyanate, naphthalene diisocyanate, triphenylmethane triisocyanate, etc.) can be mentioned. Further, the crosslinking agent (B) may be an adduct (adduct) of the isocyanate compound with a polyhydric alcohol compound [for example, an adduct with glycerol, trimethylolpropane, etc.], an isocyanurate compound, a burette type compound, a polyether polyol, a polyester polyol, an acrylic polyol, a polybutadiene polyol, a polyurethane prepolymer type isocyanate compound obtained by addition reaction with a polyisoprene polyol, etc. The crosslinking agent (B) can be used alone or in combination of two or more. Among these, typically, aromatic isocyanate compounds (such as tolylene diisocyanate, xylylene diisocyanate), aliphatic isocyanate compounds (such as hexamethylene diisocyanate) or adducts thereof with polyhydric alcohol compounds (such as glycerol, trimethylolpropane), or isocyanurate forms can be mentioned. When the crosslinking agent (B) is an aromatic isocyanate compound and / or an adduct thereof with these polyhydric alcohol compounds, or an isocyanurate form, it is advantageous for forming an optimal crosslink density (or crosslink structure), and the durability of the adhesive layer can be improved. In particular, when it is an adduct of a tolylene diisocyanate compound and / or these polyhydric alcohol compounds, the durability can be improved even when the adhesive layer is applied to a polarizing plate, for example.

[0093] The content of the crosslinking agent (B) is usually 0.01 to 15 parts by mass, preferably 0.05 to 10 parts by mass, and more preferably 0.1 to 5 parts by mass with respect to 100 parts by mass of the resin (A).

[0094] The pressure-sensitive adhesive composition of the present invention may further contain a silane compound (D). Examples of the silane compound (D) include vinyltrimethoxysilane, vinyltriethoxysilane, vinyltris(2-methoxyethoxy)silane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropylethoxydimethylsilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-chloropropylmethyldimethoxysilane, 3-chloropropyltrimethoxysilane, 3-methacryloyloxypropyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, and the like. The silane compound (D) may be a silicone oligomer. Specific examples of the silicone oligomer are shown below in the form of combinations of monomers.

[0095] Mercaptopropyl group-containing oligomers such as 3-mercaptopropyltrimethoxysilane-tetramethoxysilane oligomer, 3-mercaptopropyltrimethoxysilane-tetraethoxysilane oligomer, 3-mercaptopropyltriethoxysilane-tetramethoxysilane oligomer, 3-mercaptopropyltriethoxysilane-tetraethoxysilane oligomer; Mercaptomethyl group-containing oligomers such as mercaptomethyltrimethoxysilane-tetramethoxysilane oligomer, mercaptomethyltrimethoxysilane-tetraethoxysilane oligomer, mercaptomethyltriethoxysilane-tetramethoxysilane oligomer, mercaptomethyltriethoxysilane-tetraethoxysilane oligomer; 3-Glycidoxypropyl group-containing copolymers such as 3-glycidoxypropyltrimethoxysilane-tetramethoxysilane copolymer, 3-glycidoxypropyltrimethoxysilane-tetraethoxysilane copolymer, 3-glycidoxypropyltriethoxysilane-tetramethoxysilane copolymer, 3-glycidoxypropyltriethoxysilane-tetraethoxysilane copolymer, 3-glycidoxypropylmethyldimethoxysilane-tetramethoxysilane copolymer, 3-glycidoxypropylmethyldimethoxysilane-tetraethoxysilane copolymer, 3-glycidoxypropylmethyldiethoxysilane-tetramethoxysilane copolymer, 3-glycidoxypropylmethyldiethoxysilane-tetraethoxysilane copolymer;Methacryloyloxypropyl group-containing oligomers such as 3-methacryloyloxypropyltrimethoxysilane-tetramethoxysilane oligomer, 3-methacryloyloxypropyltrimethoxysilane-tetraethoxysilane oligomer, 3-methacryloyloxypropyltriethoxysilane-tetramethoxysilane oligomer, 3-methacryloyloxypropyltriethoxysilane-tetraethoxysilane oligomer, 3-methacryloyloxypropylmethyldimethoxysilane-tetramethoxysilane oligomer, 3-methacryloyloxypropylmethyldimethoxysilane-tetraethoxysilane oligomer, 3-methacryloyloxypropylmethyldiethoxysilane-tetramethoxysilane oligomer, 3-methacryloyloxypropylmethyldiethoxysilane-tetraethoxysilane oligomer; acryloyloxypropyl group-containing oligomers such as 3-acryloyloxypropyltrimethoxysilane-tetramethoxysilane oligomer, 3-acryloyloxypropyltrimethoxysilane-tetraethoxysilane oligomer, 3-acryloyloxypropyltriethoxysilane-tetramethoxysilane oligomer, 3-acryloyloxypropyltriethoxysilane-tetraethoxysilane oligomer, 3-acryloyloxypropylmethyldimethoxysilane-tetramethoxysilane oligomer, 3-acryloyloxypropylmethyldimethoxysilane-tetraethoxysilane oligomer, 3-acryloyloxypropylmethyldiethoxysilane-tetramethoxysilane oligomer, 3-acryloyloxypropylmethyldiethoxysilane-tetraethoxysilane oligomer; vinyl group-containing oligomers such as vinyltrimethoxysilane-tetramethoxysilane oligomer, vinyltrimethoxysilane-tetraethoxysilane oligomer, vinyltriethoxysilane-tetramethoxysilane oligomer, vinyltriethoxysilane-tetraethoxysilane oligomer, vinylmethyldimethoxysilane-tetramethoxysilane oligomer, vinylmethyldimethoxysilane-tetraethoxysilane oligomer, vinylmethyldiethoxysilane-tetramethoxysilane oligomer, 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, etc.;

[0096] The silane compound (D) may be a silane compound represented by the following formula (d1). TIFF0007715483000031.tif2567(In the formula, A 1 represents an alkanediyl group having 1 to 20 carbon atoms or a divalent alicyclic hydrocarbon group having 3 to 20 carbon atoms, and -CH2- constituting the alkanediyl group and the alicyclic hydrocarbon group may be replaced by -O- or -CO-, R 41 represents an alkyl group having 1 to 5 carbon atoms, R 42 , R 43 , R 44 , R 45 and R 46 each independently represent an alkyl group having 1 to 5 carbon atoms or an alkoxy group having 1 to 5 carbon atoms.)

[0097] A 1Examples of the C1-C20 alkanediyl group represented by include a methylene group, 1,2-ethanediyl group, 1,3-propanediyl group, 1,4-butanediyl group, 1,5-pentanediyl group, 1,6-hexanediyl group, 1,7-heptanediyl group, 1,8-octanediyl group, 1,9-nonanediyl group, 1,10-decanediyl group, 1,12-dodecanediyl group, 1,14-tetradecanediyl group, 1,16-hexadecanediyl group, 1,18-octadecanediyl group, and 1,20-icosanediyl group. Examples of the divalent alicyclic hydrocarbon group having 3 to 20 carbon atoms include 1,3-cyclopentanediyl group and 1,4-cyclohexanediyl group. Examples of the group in which -CH2- constituting the alkanediyl group and the alicyclic hydrocarbon group is replaced by -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-CH2CH2CH2CH2-.

[0098] R 41 ~R 45 Examples of the C1-C5 alkyl group represented by include a methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, tert-butyl group, and pentyl group. R 42 ~R 45 Examples of the C1-C5 alkoxy group represented by include a methoxy group, ethoxy group, propoxy group, isopropoxy group, butoxy group, isobutoxy group, tert-butoxy group, and pentyloxy group.

[0099] Examples of the silane compound represented by formula (d1) include bis(triC1-5alkoxysilyl)C1-10alkanes 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(tripropoxysilyl)hexane, 1,8-bis(trimethoxysilyl)octane, 1,8-bis(triethoxysilyl)octane, 1,8-bis(tripropoxysilyl)octane; bis(diC1-5alkoxyC1-5alkylsilyl)C1-10alkanes 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, 1,8-bis(dimethoxyethylsilyl)octane; bis(monoC1-5alkoxy-diC1-5alkylsilyl)C1-10alkanes such as 1,6-bis(methoxydimethylsilyl)hexane, 1,8-bis(methoxydimethylsilyl)octane, and the like. Among these, bis(triC1-3alkoxysilyl)C1-10alkanes 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, 1,8-bis(trimethoxysilyl)octane are preferred, and particularly, 1,6-bis(trimethoxysilyl)hexane and 1,8-bis(trimethoxysilyl)octane are preferred.

[0100] The content of the silane compound (D) is usually 0.01 to 10 parts by mass, preferably 0.03 to 5 parts by mass, more preferably 0.05 to 2 parts by mass, and still more preferably 0.1 to 1 part by mass with respect to 100 parts by mass of the resin (A).

[0101] The pressure-sensitive adhesive composition may further contain an antistatic agent. Examples of the antistatic agent include surfactants, siloxane compounds, conductive polymers, ionic compounds, etc., and an ionic compound is preferable. Examples of the ionic compound include conventional ones. Examples of the cation component constituting the ionic compound include organic cations and inorganic cations. Examples of the organic cation include pyridinium cation, pyrrolidinium cation, piperidinium cation, imidazolium cation, ammonium cation, sulfonium cation, phosphonium cation, etc. Examples of the inorganic cation include alkali metal cations such as lithium cation, potassium cation, sodium cation, cesium cation, and alkaline earth metal cations such as magnesium cation, calcium cation, etc. Particularly, pyridinium cation, imidazolium cation, pyrrolidinium cation, lithium cation, and potassium cation are preferable from the viewpoint of compatibility with the (meth)acrylic resin. The anion component constituting the ionic compound may be either an inorganic anion or an organic anion, but an anion component containing a fluorine atom is preferable in terms of antistatic performance. Examples of the anion component containing a fluorine atom include hexafluorophosphate anion (PF6-), bis(trifluoromethanesulfonyl)imide anion [(CF3SO2)2N-], bis(fluorosulfonyl)imide anion [(FSO2)2N-], tetra(pentafluorophenyl)borate anion [(C6F5)4B-], etc. These ionic compounds can be used alone or in combination of two or more. Particularly, bis(trifluoromethanesulfonyl)imide anion [(CF3SO2)2N-], bis(fluorosulfonyl)imide anion [(FSO2)2N-], and tetra(pentafluorophenyl)borate anion [(C6F5)4B-] are preferable. In terms of the temporal stability of the antistatic performance of the pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition, an ionic compound that is solid at room temperature is preferable.

[0102] The content of the antistatic agent is, for example, 0.01 to 20 parts by mass, preferably 0.1 to 10 parts by mass, and more preferably 1 to 7 parts by mass with respect to 100 parts by mass of the resin (A).

[0103] The pressure-sensitive adhesive composition may contain one or more additives such as a solvent, a crosslinking catalyst, a tackifier, a plasticizer, a softening agent, a pigment, a rust inhibitor, an inorganic filler, and light-scattering fine particles.

[0104] <Pressure-sensitive adhesive layer> The pressure-sensitive adhesive layer of the present invention can be formed, for example, by dissolving or dispersing the pressure-sensitive adhesive composition in a solvent to obtain a solvent-containing pressure-sensitive adhesive composition, and then applying this to the surface of a substrate and drying it. As the substrate, a plastic film is preferable, and specifically, a release film subjected to a release treatment can be mentioned. Examples of the release film include those obtained by subjecting one surface of a film made of a resin such as polyethylene terephthalate, polybutylene terephthalate, polycarbonate, and polyarylate to a release treatment such as a silicone treatment.

[0105] The pressure-sensitive adhesive layer of the present invention preferably satisfies the following formula (3), and more preferably satisfies formula (4). A(405) ≧ 0.5 (3) [In formula (3), A(405) represents the absorbance at a wavelength of 405 nm.] A(405) / A(440) ≧ 5 (4) [In formula (4), A(405) represents the absorbance at a wavelength of 405 nm, and A(440) represents the absorbance at a wavelength of 440 nm.]

[0106] The larger the value of A(405), the higher the absorption at a wavelength of 405 nm. When the value of A(405) is less than 0.5, the absorption at a wavelength of 405 nm is low, and the organic EL light-emitting element and the liquid crystal retardation film are likely to deteriorate due to light near 400 nm. The value of A(405) is preferably 0.6 or more, more preferably 0.8 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(405) / A(440) represents the magnitude of absorption at a wavelength of 405 nm relative to the magnitude of absorption at a wavelength of 440 nm. The larger the value of A(405) / A(440), the more specific the absorption in the wavelength range near 405 nm. When the adhesive layer of the present invention is applied to a display device such as an organic EL display device or a liquid crystal display device, it can absorb light near 400 nm without inhibiting the color expression of the display device and suppress the light deterioration of the organic EL light-emitting element and the liquid crystal retardation film. The value of A(405) / A(440) is preferably 10 or more, more preferably 30 or more, and even more preferably 60 or more.

[0107] The thickness of the adhesive layer of the present invention is usually 0.1 to 100 μm, preferably 3 to 50 μm, and more preferably 4 to 25 μm.

[0108] <Optical laminate> The adhesive composition of the present invention and the adhesive layer formed from the adhesive composition can be used, for example, for laminating optical films. An optical laminate in which an optical film is laminated on at least one surface of the adhesive layer of the present invention is also included in the present invention. The optical laminate of the present invention can be formed by dissolving or dispersing the adhesive composition in a solvent to obtain a solvent-containing adhesive composition, then applying this to the surface of an optical film and drying it. It can also be obtained by forming an adhesive layer in the same manner on a release film and laminating (transferring) this adhesive layer onto the surface of an optical film.

[0109] The optical laminate including the adhesive layer of the present invention will be described with reference to the drawings. An example of the layer structure of the adhesive layer of the present invention and the optical laminate of the present invention is shown in FIGS. 1 to 5. The adhesive layer 1 shown in FIG. 1 is in a state where a release film 2 is attached to the adhesive layer surface 1 for temporary protection of the adhesive layer surface. The optical laminate 10A shown in FIG. 2 is an optical laminate including an optical film 40, the adhesive layer 1 of the present invention, and a release film 2. The optical laminate 10B shown in FIG. 3 is an optical laminate including a protective film 8, an adhesive layer 7, a polarizing film 9, an adhesive layer 7, a protective film 8, the adhesive layer 1 of the present invention, and a release film 2. The optical laminates 10C shown in FIG. 4 and the optical laminate 10D shown in FIG. 5 are optical laminates including a protective form 8, an adhesive layer 7, a polarizing film 9, an adhesive layer 7, a protective film 8, the adhesive layer 1 of the present invention, a retardation film 110, an adhesive layer 7a, and a light-emitting element 30 (liquid crystal cell, organic EL cell).

[0110] The optical film 40 is a film having optical functions such as transmitting, reflecting, and absorbing light rays. The optical film 40 may be a single-layer film or a multi-layer film. Examples of the optical film 40 include a polarizing film, a retardation film, a brightness enhancement film, an antiglare film, an antireflection film, a diffusion film, a light condensing film, a window film, etc., and it is preferably a polarizing film, a retardation film, a window film, or a laminated film thereof.

[0111] The light condensing film is used for the purpose of optical path control, etc., and can be a prism array sheet, a lens array sheet, a dot-attached sheet, etc.

[0112] The brightness enhancement film is used for the purpose of improving the brightness in a liquid crystal display device to which a polarizing plate is applied. Specifically, a reflective type polarization separation sheet designed to laminate a plurality of thin film films having different refractive index anisotropies so as to cause anisotropy in reflectance, a cholesteric liquid crystal polymer alignment film, or a circular polarization separation sheet in which its aligned liquid crystal layer is supported on a base film, etc. are mentioned.

[0113] A window film refers to the front panel in a flexible display device such as a flexible display, and is generally disposed on the outermost surface of the display device. Examples of the window film include a resin film made of, for example, a polyimide resin. The window film may be a hybrid film of an organic material and an inorganic material, such as a resin film containing polyimide and silica. Further, a hard coat layer for imparting surface hardness, antifouling property, and fingerprint resistance may be disposed on the surface of the window film. Examples of the window film include, for example, the film described in JP-A-2017-94488.

[0114] A polarizing film is a film having a property of absorbing linearly polarized light having a vibration plane parallel to its absorption axis and transmitting linearly polarized light having 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 the dichroic dye include iodine and dichroic organic dyes. The saponification degree of the polyvinyl alcohol-based resin is usually 85 mol% to 100 mol%, preferably 98 mol% or more. The polyvinyl alcohol-based resin may be modified, and examples thereof include polyvinyl formal and polyvinyl acetal modified with an aldehyde. The degree of polymerization of the polyvinyl alcohol-based resin is usually 1,000 to 10,000, preferably 1,500 to 5,000.

[0115] Usually, a film formed from a polyvinyl alcohol-based resin is used as the raw film of 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 usually 1 to  150 μm, and preferably 10 μm or more in consideration of ease of stretching.

[0116] The polarizing film is manufactured, for example, by subjecting a raw film to a process of uniaxial stretching, a process of dyeing the film with a dichroic dye and adsorbing the dichroic dye, a process of treating the film with an aqueous boric acid solution, and a process of washing the film with water, and finally drying it. The thickness of the polarizing film is usually 1 to 30 μm, and from the viewpoint of thinning the adhesive layer-attached optical laminate, it is preferably 20 μm or less, more preferably 15 μm or less, and particularly preferably 10 μm or less.

[0117] It is preferable that at least one surface of the polarizing film is a polarizing plate provided with a protective film via an adhesive. As the adhesive, a known adhesive may be used, which may be an aqueous adhesive or an active energy ray-curable adhesive.

[0118] Examples of the aqueous adhesive include conventional aqueous adhesives (for example, adhesives composed of aqueous solutions of polyvinyl alcohol-based resins, aqueous two-component urethane-based emulsion adhesives, crosslinking agents such as aldehyde compounds, epoxy compounds, melamine-based compounds, methylol compounds, isocyanate compounds, amine compounds, and polyvalent metal salts). Among these, an aqueous adhesive composed of an aqueous solution of a polyvinyl alcohol-based resin can be preferably used. When using an aqueous adhesive, after laminating the polarizing film and the protective film, it is preferable to carry out a drying process to remove the water contained in the aqueous adhesive. After the drying process, a curing process of curing, for example, at a temperature of about 20 to 45 °C may be provided. The adhesive layer formed from the aqueous adhesive is usually 0.001 to 5 μm.

[0119] The active energy ray-curable adhesive refers to an adhesive that cures by irradiating active energy rays such as ultraviolet rays and electron beams. Examples thereof include curable compositions containing a polymerizable compound and a photoinitiator, curable compositions containing a photoreactive resin, curable compositions containing a binder resin and a photoreactive crosslinking agent, etc., and preferably an ultraviolet ray-curable adhesive.

[0120] As a method of bonding a polarizing film and a protective film, methods such as subjecting at least one of their bonding surfaces to a surface activation treatment such as saponification treatment, corona treatment, plasma treatment, etc. can be mentioned. When protective films are bonded to both sides of the polarizing film, the adhesive for bonding these resin films may be the same type of adhesive or different types of adhesives.

[0121] The protective film is preferably a film formed from a thermoplastic resin having light transmittance. Specifically, films made of polyolefin resins; cellulose resins; polyester resins; (meth)acrylic resins; or mixtures, copolymers, etc. of these can be mentioned. 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 the 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. By using these films, it is possible to effectively suppress the shrinkage of the polarizing film in a high-temperature environment without impairing the optical properties of the polarizing film. Note that the protective film may also be an oxygen barrier layer.

[0122] A preferred configuration of the polarizing plate is a polarizing plate in which a protective film is laminated on at least one surface of the polarizing film via an adhesive layer. When the protective film is laminated only on one surface of the 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 resin or a cycloolefin resin. The protective film may be an unstretched film or may be stretched in an arbitrary direction and have a retardation. A surface treatment layer such as a hard coat layer or an antiglare layer may be provided on the surface of the protective film laminated on the viewing side. When the protective film is laminated on both sides of the polarizing film, the protective film on the panel side (the side opposite to the viewing side) is preferably a protective film or a retardation film made of a triacetyl cellulose-based resin, a cycloolefin-based resin, or an acrylic-based resin. The retardation film may be a zero retardation film described later.

[0123] A retardation film is an optical film exhibiting optical anisotropy. For example, it can be a stretched film obtained by stretching a polymer film 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. about 1.01 to 6 times. Among the stretched films, it is preferably a polymer film obtained by uniaxially or biaxially stretching an acetyl cellulose, polyester, polycarbonate film, or cycloolefin-based resin film. Also, the retardation film may be a retardation film in which a liquid crystalline compound is applied to a substrate and oriented to exhibit optical anisotropy. In this specification, the retardation film includes a zero retardation film and also includes films referred to as uniaxial retardation films, low photoelastic modulus retardation films, wide viewing angle retardation films, etc.

[0124] A zero retardation film refers to the front retardation R e and the retardation R in the thickness direction thBoth are in the range of -15 to 15 nm, referring to an optically isotropic film. Examples of the zero retardation film include resin films made of cellulose-based resins, polyolefin-based resins (such as chain polyolefin-based resins and polycycloolefin-based resins), or polyethylene terephthalate-based resins. Cellulose-based resins or polyolefin-based resins are preferred in that the retardation value can be easily controlled and they are easily available. The zero retardation film can also be used as a protective film. Examples of the zero retardation film include "Z-TAC" (trade name) sold by Fuji Film Co., Ltd., "Zero Tack (registered trademark)" sold by Konica Minolta Opto Co., Ltd., and "ZF-14" (trade name) sold by Nippon Zeon Co., Ltd.

[0125] In the optical film of the present invention, the retardation film is preferably a retardation film in which a liquid crystalline compound exhibits optical anisotropy by coating and alignment.

[0126] Examples of the film in which optical anisotropy is exhibited by coating and alignment of the liquid crystalline compound include the following first to fifth forms. First form: A retardation film in which rod-like liquid crystalline compounds are aligned in the horizontal direction with respect to the support substrate Second form: A retardation film in which rod-like liquid crystalline compounds are aligned in the vertical direction with respect to the support substrate Third form: A retardation film in which the alignment direction of rod-like liquid crystalline compounds changes spirally in the plane Fourth form: A retardation film in which disc-like liquid crystalline compounds are inclinedly aligned Fifth form: A biaxial retardation film in which disc-like liquid crystalline compounds are aligned in the vertical direction with respect to the support substrate

[0127] For example, as the optical film used in an organic electroluminescence display, the first form, the second form, and the fifth form are preferably used. Or retardation films of these forms may be laminated and used.

[0128] When the retardation film is a layer made of a polymer in the alignment 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 at a short wavelength is smaller than the in-plane retardation value at a long wavelength. Preferably, the retardation film satisfies the following formulas (7) and (8). Note that 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 is in the first form and has reverse wavelength dispersion, it is preferable because coloring during black display in a display device is reduced. More preferably, 0.82≦Re(450) / Re(550)≦0.93 in the formula (7). Further, 120≦Re(550)≦150 is preferable.

[0129] Examples of the polymerizable liquid crystal compound when the retardation film is a film having an optically anisotropic layer include compounds having a polymerizable group among the compounds described in "3.8.6 Network (fully crosslinked type)" and "6.5.1 Liquid crystal materials b. Polymerizable nematic liquid crystal materials" in the Liquid Crystal Handbook (edited by the Liquid Crystal Handbook Editorial Committee, published by Maruzen Co., Ltd. on October 30, 2000), and polymerizable liquid crystal compounds described in JP-A-2010-31223, JP-A-2010-270108, JP-A-2011-6360, JP-A-2011-207765, JP-A-2011-162678, JP-A-2016-81035, International Publication No. 2017 / 043438, and JP-T-2011-207765.

[0130] Examples of the method for producing a retardation film from a polymer in the alignment state of a polymerizable liquid crystal compound include the method described in JP-A-2010-31223.

[0131] In the case of the second form, the front retardation value Re(550) may be adjusted to the range of 0 to 10 nm, preferably 0 to 5 nm, and the retardation value R in the thickness directionth should be adjusted to the range of -10 to -300 nm, preferably -20 to -200 nm. The retardation value R in the thickness direction, which means the refractive index anisotropy in the thickness direction th is the retardation value R measured by tilting 50 degrees with the in-plane fast axis as the tilt axis 50 and the in-plane retardation value R0. That is, the retardation value R in the thickness direction th is the in-plane retardation value R0, the retardation value R measured by tilting 50 degrees 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. From the following formulas (10) to (12), n x , n y and n z are obtained, substituted into formula (9), and can be calculated

[0132] 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) Here 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

[0133] Examples of films that exhibit optical anisotropy through the coating and alignment of liquid crystalline compounds, or films that exhibit optical anisotropy through the coating of inorganic layered compounds, include films referred to as temperature-compensating retardation films, "NH films" (trade name; films with rod-like liquid crystals in a tilted alignment) sold by JX Nippon Oil & Energy Corporation, "WV films" (trade name; films with discotic liquid crystals in a tilted alignment) sold by Fujifilm Corporation, "VAC films" (trade name; completely biaxially oriented films) sold by Sumitomo Chemical Co., Ltd., and "new VAC films" (trade name; biaxially oriented films) sold by Sumitomo Chemical Co., Ltd.

[0134] The retardation film may be a multilayer film having two or more layers. For example, there are those in which a protective film is laminated on one or both sides of the retardation film, and those in which two or more retardation films are laminated via an adhesive or bonding agent.

[0135] When the retardation film is a multilayer film, examples of the configuration of the optical laminate including the optical film of the present invention include, as shown in FIG. 4, a retardation film 110 in which a quarter-wave retardation layer 50 that imparts a quarter-wavelength retardation to transmitted light and a half-wave retardation layer 70 that imparts a half-wavelength retardation to transmitted light are laminated via an adhesive layer or pressure-sensitive adhesive layer 60. Also, as shown in FIG. 5, there is a configuration including an optical film 40 in which a quarter-wave retardation layer 50a and a positive C layer 80 are laminated via an adhesive layer or pressure-sensitive adhesive layer 60.

[0136] The quarter-wave retardation layer 50 that imparts a quarter-wavelength retardation in FIG. 4 and the half-wave retardation layer 70 that imparts a half-wavelength retardation to transmitted light may be the optical film of the first form or the optical film of the fifth form. In the case of the configuration of FIG. 4, it is more preferable that at least one of them is in the fifth form.

[0137] In the case of the configuration of FIG. 5, the quarter-wave retardation layer 50a is preferably the optical film of the first form, and more preferably satisfies formulas (7) and (8). In FIGS. 4 and 5, the adhesive layer 7a is a layer formed from an adhesive composition. As the adhesive layer 7a, a known adhesive composition may be used, or the adhesive composition of the present invention may be used.

[0138] <Liquid crystal display device> The optical laminate including the resin of the present invention, the adhesive composition containing the resin, and the adhesive layer formed from the adhesive composition can be laminated on display elements such as organic EL elements and liquid crystal cells, and can be used for display devices (FPD: flat panel display) such as organic EL display devices and liquid crystal display devices.

Examples

[0139] Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples. In Examples, Comparative Examples, and Polymerization Examples, “%” and “parts” are “% by mass” and “parts by mass”, respectively, unless otherwise specified.

[0140] [Example 1]: Synthesis of a photoselective absorption compound having an indole structure and a polymerizable group After replacing the inside of a 1000 mL four-necked flask equipped with a Dimroth condenser and a thermometer with a nitrogen atmosphere, 100 parts of the compound represented by the formula (1) (1-methyl-2-phenyl-1H-indole-3-carboxaldehyde), 40 parts of cyanoacetic acid, 76 parts of piperidine, and 300 parts of acetonitrile were charged, and the mixture was kept at 80° C. for 4 hours while stirring. The precipitated crystals were separated by filtration from the obtained mixture and taken out. The obtained crystals were mixed with 500 parts of 5% sulfuric acid, and the mixture was kept at 80° C. for 1 hour while stirring. The obtained mixture was filtered to obtain a solid. The obtained solid was washed with 300 parts of water and dried to obtain 116 parts of the compound represented by the formula (2) (2-cyano-3-(1-methyl-2-phenyl-1H-indol-3-yl)-2-propenoic acid).

[0141] Identification of the compound represented by the formula (2) 11H-NMR (CDCl3) δ: 3.70 (s, 3H), 7.30 - 7.42 (dt, 2H), 7.50 - 7.55 (m, 2H), 7.60 - 7.64 (m, 3H), 7.68 (d, 1H), 7.93 (s, 1H), 8.26 (d, 1H)

[0142] After replacing the atmosphere inside a 100 mL four-necked flask equipped with a thermometer with a nitrogen atmosphere, 5 parts of the compound represented by formula (2), 2.3 parts of 4-hydroxybutyl acrylate, 0.4 part of N,N-dimethyl-4-aminopyridine, 0.2 part of 2,6-di-t-butyl-4-methylphenol, and 50 parts of trichloromethane were charged and cooled to 0 °C. To the resulting mixture, 2.2 parts of N,N'-diisopropylcarbodiimide was added dropwise while maintaining the temperature at 0 - 5 °C. After the addition, the resulting mixture was kept at 10 °C for 4 hours. The resulting mixture was filtered to obtain a filtrate. The obtained filtrate was concentrated to obtain an oil. To the obtained oil, 50 parts of toluene and 50 parts of water were mixed and separated to obtain a toluene layer. The obtained toluene layer was concentrated to obtain yellow crude crystals. The crude crystals were recrystallized from isopropyl alcohol to obtain 4.9 parts of the compound represented by formula (3) (2-cyano-3-(1-methyl-2-phenyl-1H-indol-3-yl)-2-propenoic acid 4-acryloyloxybutyl). The maximum absorption wavelength of the compound represented by formula (3) was 386 nm.

[0143] Identification of the compound represented by formula (3) 1 1H-NMR (CDCl3) δ: 1.75 - 1.80 (m, 4H), 3.70 (s, 3H), 4.15 - 4.20 (t, 2H), 4.23 - 4.27 (t, 2H), 5.78 - 5.82 (dd, 1H), 6.06 - 6.14 (dd, 1H), 6.36 - 6.41 (dd, 1H), 7.35 - 7.43 (m, 5H), 7.54 - 7.57 (m, 3H), 8.12 (s, 1H), 8.42 - 8.45 (m, 1H)

[0144] A methyl ethyl ketone solution (0.006 g / L) of the obtained compound represented by formula (3) was placed in a 1-cm quartz cell. The quartz cell was set in a spectrophotometer UV-2450 (manufactured by Shimadzu Corporation), and the absorbance was measured in the wavelength range of 300 to 800 nm at 1-nm steps by the double-beam method. From the obtained absorbance values, the concentration of the compound in the solution, and the optical path length of the quartz cell, the gram absorption coefficient for each wavelength was calculated. As a result, ε(405) = 34.9 L / (g·cm), ε(440) = 2.0 L / (g·cm), and ε(405) / ε(440) = 17.5. ε(λ)=A(λ) / CL [In the formula, ε(λ) represents the gram absorption coefficient L / (g·cm) of the compound represented by formula (3) at a wavelength of λ nm, A(λ) represents the absorbance at a wavelength of λ nm, C represents the concentration g / L, and L represents the optical path length cm of the quartz cell. ]

[0145] [Example 2]: Synthesis of a photoselective absorption compound having an indole structure and a polymerizable group Instead of 2.3 parts of 4-hydroxybutyl acrylate, 2 parts of 2-hydroxyethyl acrylate was used. Otherwise, in the same manner as in Example 1, 4.3 parts of the compound represented by formula (4) (2-cyano-3-(1-methyl-2-phenyl-1H-indol-3-yl)-2-propenoic acid 2-acryloyloxyethyl) was obtained. The maximum absorption wavelength of the compound represented by formula (4) was 388 nm. When the gram absorption coefficient was determined in the same manner as in Example 1, ε(405) = 45.4 L / (g·cm), ε(440) = 1.0 L / (g·cm), and ε(405) / ε(440) = 45.4.

[0146] Identification of the compound represented by formula (4) 1H-NMR(CDCl3)δ:3.70(s, 3H), 4.38-4.43(dt, 2H), 4.43-4.48(dt, 2H), 5.83-5.86(dd, 1H), 6.09-6. 17(dd, 1H), 6.4-6.45(dd, 1H) 7.35-7.45(m, 5H), 7.52-7.58(m, 3H), 8.12(s, 1H), 8.42-8.45(m, 1H)

[0147] [Example 3]: Synthesis of Resin (A-1) Containing a Structural Unit Having an Indole Structure A reaction vessel equipped with a condenser, nitrogen inlet, thermometer, and stirrer was charged with a mixed solution of 141 parts ethyl acetate as a solvent, 94 parts butyl acrylate, 3 parts 2-hydroxyethyl acrylate, and 3 parts of the compound represented by formula (3). The air in the vessel was purged with nitrogen gas to remove oxygen, and the internal temperature was raised to 60°C. A solution of 0.63 parts azobisisobutyronitrile (polymerization initiator) in 10 parts ethyl acetate was added to the resulting mixture. The resulting mixture was maintained at 60°C for 7 hours, and then a solution of 0.0012 parts 4-methoxyphenol (polymerization inhibitor) in 5 parts ethyl acetate was added to the resulting mixture. Ethyl acetate was added to the resulting mixture to adjust the concentration of the resin (A-1) having an indole structure to 20%, thereby preparing an ethyl acetate solution of the resin (A-1) having an indole structure. The resulting resin (A-1) had a weight-average molecular weight (Mw) of 740,000 as measured by GPC in terms of polystyrene, and an Mw / Mn ratio of 5.2. The glass transition temperature measured by DSC was -51°C.

[0148] <Gram absorption coefficient ε measurement> The methyl ethyl ketone solution (0.11 g / L) of the obtained resin (A-1) was placed in a 1-cm quartz cell. The quartz cell was set in a spectrophotometer UV-2450 (manufactured by Shimadzu Corporation), and the absorbance was measured in the wavelength range of 300 to 800 nm at 1-nm steps by the double-beam method. From the obtained absorbance values, the resin (A) concentration in the solution, and the optical path length of the quartz cell, the gram extinction coefficient for each wavelength was calculated. As a result, ε(405) = 0.442 L / (g·cm), ε(440) = 0.008 L / (g·cm), and ε(405) / ε(440) = 53.3 for the resin (A-1). ε(λ)=A(λ) / CL [In the formula, ε(λ) represents the gram extinction coefficient L / (g·cm) of the resin (A) at a wavelength of λ nm, A(λ) represents the absorbance at a wavelength of λ nm, C represents the concentration in g / L, and L represents the optical path length of the quartz cell in cm.]

[0149] [Example 4]: Synthesis of a resin (A-2) containing a structural unit having an indole structure A reaction vessel equipped with a cooling pipe, a nitrogen introduction pipe, a thermometer, and a stirrer was charged with a mixed solution of 141 parts of ethyl acetate, 94 parts of butyl acrylate, 3 parts of 2-hydroxyethyl acrylate, and 3 parts of the compound represented by the formula (4) as a solvent. The internal temperature was set to 60°C while replacing the air in the apparatus with nitrogen gas to make it oxygen-free. A solution prepared by dissolving 0.63 parts of azobisisobutyronitrile (polymerization initiator) in 10 parts of ethyl acetate was added in its entirety to the obtained mixture. The obtained mixture was held at 60°C for 7 hours, and then a solution prepared by dissolving 0.0012 parts of 4-methoxyphenol (polymerization inhibitor) in 5 parts of ethyl acetate was added in its entirety to the obtained mixture. Ethyl acetate was added to the obtained mixture to adjust the concentration of the resin (A-2) having an indole structure to 20%, and an ethyl acetate solution of the resin (A-2) having an indole structure was prepared. The obtained resin (A-2) having an indole structure had a weight-average molecular weight Mw of 670,000 in terms of polystyrene by GPC and Mw / Mn of 4.9. The glass transition temperature by DSC was -50°C. Also, as a result of measuring the gram absorption coefficient of the resin (A-2) by the same method as in Example 3, ε(405) = 0.336 L / (g·cm), ε(440) = 0.035 L / (g·cm), and ε(405) / ε(440) = 9.5.

[0150] [Polymerization Example 1]: Preparation of Acrylic Resin (A-3) 141 parts of ethyl acetate, 94 parts of butyl acrylate, and 3 parts of 2-hydroxyethyl acrylate were charged, and the air in the apparatus was replaced with nitrogen gas to make it oxygen-free while setting the internal temperature to 60°C. To the obtained mixture, a solution prepared by dissolving 0.63 parts of azobisisobutyronitrile (polymerization initiator) in 10 parts of ethyl acetate was added in its entirety. The obtained mixture was held at 60°C for 7 hours, and then a solution prepared by dissolving 0.0012 parts of 4-methoxyphenol (polymerization inhibitor) in 5 parts of ethyl acetate was added in its entirety to the obtained mixture. Ethyl acetate was added to the obtained mixture to adjust the concentration of acrylic resin (A-3) to 20%, and an ethyl acetate solution of acrylic resin (A-3) was prepared. The obtained acrylic resin (A-3) had a weight average molecular weight Mw of 600,000 in terms of polystyrene by GPC and Mw / Mn of 6.0. The glass transition temperature by DSC was -49°C. Also, as a result of measuring the gram absorption coefficient in the same manner as in Example 3, there was no absorption at a wavelength of 405 nm and a wavelength of 440 nm, and all absorbances were 0.

[0151] <Preparation of Adhesive Composition and Adhesive Layer> (a) Preparation of Adhesive Composition [Example 5]: Preparation of Adhesive Composition (1) To an ethyl acetate solution (resin concentration: 20%) of the obtained resin (A-1) having an indole structure, 0.5 parts of a crosslinking agent (Coronate L, solid content 75%: manufactured by Tosoh Corporation) and 0.5 parts of a silane compound (manufactured by Shin-Etsu Chemical Co., Ltd.: KBM-403) were mixed with respect to 100 parts of the solid content of the solution, and 2-butanone was further added so that the solid content concentration became 14% to obtain an adhesive composition (1). The blending amount of the above crosslinking agent (Coronate L) is the number of parts by mass as the active ingredient.

[0152] [Example 6]: Preparation of Adhesive Composition (2) To a solution of resin (A-2) having the obtained indole structure in ethyl acetate (resin concentration: 20%), 0.5 part of a crosslinking agent (Coronate L, solid content 75%: manufactured by Tosoh Corporation) and 0.5 part of a silane compound (KBM-403 manufactured by Shin-Etsu Chemical Co., Ltd.) were mixed with respect to 100 parts of the solid content of the solution, and 2-butanone was further added so that the solid content concentration became 14% to obtain an adhesive composition (2). The blending amount of the above crosslinking agent (Coronate L) is the number of parts by mass as an active ingredient.

[0153] [Comparative Example 1]: Preparation of Adhesive Composition (3) To a solution of acrylic resin (A-3) in ethyl acetate (resin concentration: 20%), 0.5 part of a crosslinking agent (Coronate L, solid content 75%: manufactured by Tosoh Corporation), 0.5 part of a silane compound (KBM-403 manufactured by Shin-Etsu Chemical Co., Ltd.) and 3 parts of a light-absorbing compound (ultraviolet absorber; BONASORB UA-3911 manufactured by Orient Chemical Industries Co., Ltd.) were mixed with respect to 100 parts of the solid content of the solution, and 2-butanone was further added so that the solid content concentration became 14% to obtain an adhesive composition (3). The blending amount of the above crosslinking agent (Coronate L) is the number of parts by mass as an active ingredient.

[0154] [Production Example 1]: Preparation of Adhesive Composition (4) To a solution of acrylic resin (A-3) in ethyl acetate (resin concentration: 20%), 0.5 part of a crosslinking agent (Coronate L, solid content 75%: manufactured by Tosoh Corporation) and 0.5 part of a silane compound (KBM-403 manufactured by Shin-Etsu Chemical Co., Ltd.) were mixed with respect to 100 parts of the solid content of the solution, and 2-butanone was further added so that the solid content concentration became 14% to obtain an adhesive composition (4).

[0155] (b) Preparation of Adhesive Layer Each of the adhesive compositions prepared in (a) above was applied to the release-treated surface of a polyethylene terephthalate film (SP-PLR382050 manufactured by Lintec Corporation, hereinafter abbreviated as "separator") having a release treatment using an applicator, and dried at 100°C for 1 minute to prepare an adhesive layer. The thickness of the obtained adhesive layer was 15 μm. The pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition obtained in Example 5 was designated as pressure-sensitive adhesive layer (1), the pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition obtained in Example 6 was designated as pressure-sensitive adhesive layer (2), the pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition obtained in Comparative Example 1 was designated as pressure-sensitive adhesive layer (3), and the pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition obtained in Production Example 1 was designated as pressure-sensitive adhesive layer (4).

[0156] <Measurement of Absorbance of Pressure-Sensitive Adhesive Layer> The obtained pressure-sensitive adhesive layer (1) was laminated on non-alkali glass [product name "EAGLE XG" manufactured by Corning Inc.]. After peeling off the separator, a cycloolefin-based resin film (ZF-14 manufactured by Nippon Zeon Co., Ltd.) was laminated on the pressure-sensitive adhesive layer (1) to prepare a laminate for evaluating the pressure-sensitive adhesive layer. The prepared laminate for evaluating the pressure-sensitive adhesive layer was set in a spectrophotometer UV-2450 (manufactured by Shimadzu Corporation), and the absorbance was measured in the wavelength range of 300 to 800 nm at 1 nm steps by the double-beam method. The absorbances of the non-alkali glass alone and the cycloolefin-based resin film alone at wavelengths of 405 nm and 440 nm were both 0. Similarly, the absorbances of the pressure-sensitive adhesive layer (2) and the pressure-sensitive adhesive layer (3) were also measured. The absorbances of the pressure-sensitive adhesive layers (1) to (3) are shown in Table 1.

[0157]

Table 1

[0158] <Fabrication of Optical Laminate> (i) Fabrication of Polarizing Film A polyvinyl alcohol film (Kuraray POVAL Film VF-PE#3000, manufactured by Kuraray Co., Ltd.) with an average degree of overlap of about 2400, a saponification degree of 99.9 mol%, and a thickness of 30 μm was immersed in pure water at 37°C and then immersed in an aqueous solution containing iodine and potassium iodide (iodine / potassium iodide / water (weight ratio) = 0.04 / 1.5 / 100) at 30°C. Thereafter, it was immersed in an aqueous solution containing potassium iodide and boric acid (potassium iodide / boric acid / water (weight ratio) = 12 / 3.6 / 100) at 56.5°C. Next, the film was washed with pure water at 10°C and then dried at 85°C to obtain a polarizing film A with a thickness of about 12 μm in which iodine was adsorbed and oriented on the polyvinyl alcohol. The stretching was mainly carried out in the steps of iodine staining and boric acid treatment, and the total stretching ratio was 5.3 times.

[0159] (ii) Production of a polarizing plate A transparent protective film (25KCHCN-TC, manufactured by Toppan Printing Co., Ltd.) obtained by applying a 7-μm hard coat layer to a 25-μm-thick triacetyl cellulose film was laminated on one side of the polarizing film obtained in (i) via an adhesive composed of an aqueous solution of a polyvinyl alcohol-based resin, and a 23-μm-thick cycloolefin-based resin film (ZF14-023, manufactured by Nippon Zeon Co., Ltd.) was laminated on the surface opposite to the transparent protective film to produce an optical film A (polarizing plate, thickness 67 μm).

[0160] (iii) Preparation of a composition for forming an optically oriented film A compound having the following structure was synthesized by the method described in JP-A-2013-33248. 5 parts of the following compound and 95 parts of cyclopentanone were mixed as components, and the resulting mixture was stirred at 80°C for 1 hour to obtain a composition for forming an optically oriented film. TIFF0007715483000036.tif21150

[0161] (iv) Preparation of a composition containing a polymerizable liquid crystal compound A polymerizable liquid crystal compound A having the following structure was synthesized by the method described in JP-A-2010-31223. The maximum absorption wavelength λmax(LC) of the polymerizable liquid crystal compound A was 350 nm. 12 parts of a polymerizable liquid crystal compound A having the following structure, 0.12 parts of a polyacrylate compound (a leveling agent; BYK-361N manufactured by BYK-Chemie), 0.72 parts of a polymerization initiator (Irgacure 369 manufactured by Ciba Specialty Chemicals), and 100 parts of cyclopentanone were mixed to obtain a composition containing a polymerizable liquid crystal compound. TIFF0007715483000037.tif35146

[0162] (v) Production of the optically anisotropic layer A cycloolefin resin film (ZF-14 manufactured by Nippon Zeon Co., Ltd.) was treated once using a corona treatment apparatus (AGF-B10, manufactured by Kasuga Electric Co., Ltd.) under the conditions of an output of 0.3 kW and a treatment speed of 3 m / min. The composition for forming an optical alignment film obtained in (iii) was applied by a bar coater on the surface subjected to the corona treatment and dried at 80°C for 1 minute. Using a polarized UV irradiation apparatus (SPOT CURE SP-7; manufactured by Ushio Inc.), polarized UV exposure was carried out with an integrated light quantity of 100 mJ / cm 2 . When the film thickness of the obtained alignment film was measured with an ellipsometer, it was 100 nm. Subsequently, a coating liquid composed of the composition A containing the polymerizable liquid crystal compound obtained in (iv) was applied on the alignment film using a bar coater, dried at 120°C for 1 minute, and then ultraviolet rays were irradiated from the side of the surface coated with the composition containing the polymerizable liquid crystal compound using a high-pressure mercury lamp (Unicure VB-15201BY-A, manufactured by Ushio Inc.) (in a nitrogen atmosphere, integrated light quantity at a wavelength of 313 nm: 500 mJ / cm 2 ) to form an optical film containing the optically anisotropic layer 1. When the film thickness of the obtained optically anisotropic layer 1 was measured with a laser microscope, it was 2 μm.

[0163] [Example 7]: Production of the optical laminate (1) An adhesive layer (1) was laminated on the cycloolefin resin film surface of the polarizing plate produced in the above (ii), and the separator was peeled off. Further, the surface of the adhesive layer (1) from which the separator was peeled off was laminated with the opposite surface of the cycloolefin resin film surface of the optical anisotropic layer produced in (v), and the cycloolefin resin film was peeled off. A separator-attached adhesive layer (4) was laminated on the surface of the optical anisotropic layer from which the cycloolefin resin film was peeled off to obtain an optical laminate (1).

[0164] [Example 8]: Production of optical laminate (2) An optical laminate (2) was obtained in the same manner as in Example 7, except that the adhesive layer (1) was replaced with the adhesive layer (2).

[0165] [Comparative Example 2]: Production of optical laminate (3) An optical laminate (3) was obtained in the same manner as in Example 7, except that the adhesive layer (1) was replaced with the adhesive layer (3).

[0166] [Production Example 2]: Production of optical laminate (4) An optical laminate (4) was obtained in the same manner as in Example 5, except that the adhesive layer (1) was replaced with the adhesive layer (4).

[0167] [Evaluation of bleed resistance of adhesive layer] The obtained optical laminate (1) was cut into a size of 40 mm × 40 mm, the separator laminated on the adhesive layer (4) was peeled off, and this was laminated with non-alkali glass [trade name "EAGLE XG" manufactured by Corning Inc.]. The obtained optical laminate with glass was used to confirm the precipitation of crystals of the compound in the plane using a microscope. Thereafter, the obtained optical laminate with glass was placed in an oven at a temperature of 23°C and 60% for 500 hours, and the precipitation of crystals of the compound in the plane was confirmed using a microscope to check whether there was an increase in the precipitation of crystals of the compound. The evaluation results are shown in Table 2.

[0168] The bleed resistance of the adhesive layer was evaluated in the same manner as above, except that the optical laminate (1) was replaced with the optical laminate (2). The evaluation results are shown in Table 2.

[0169] The bleed resistance of the pressure-sensitive adhesive layer was evaluated in the same manner as above, except that the optical laminate (1) was replaced with the optical laminate (3). The evaluation results are shown in Table 2.

[0170] <Confirmation of the influence of the pressure-sensitive adhesive layer on the retardation change in the optically anisotropic layer> The obtained optical laminate (1) was cut into a size of 40 mm × 40 mm, the separator laminated on the pressure-sensitive adhesive layer (4) was peeled off, and this was bonded to non-alkali glass [product name “EAGLE XG” manufactured by Corning Inc.]. The retardation value at a wavelength of 45 nm of the obtained optical laminate with glass was measured using a birefringence measuring device (KOBRA-WR; manufactured by Oji Scientific Instruments Co., Ltd.). Then, the optical laminate with glass was placed in an oven at a temperature of 80 °C for 120 hours, taken out, left to stand in an environment of 23 °C and 50% for 24 hours, and then the retardation value at a wavelength of 450 nm was measured again. In the same manner as above, measurement was performed with the optical laminate (1) replaced by the optical laminate (4). The change in the retardation value of the optical laminate (1) was obtained by subtracting the change in the retardation value at a wavelength of 450 nm before and after durability of the optical laminate (4) from the change in the retardation value at a wavelength of 450 nm before and after durability of the optical laminate (1). The change values of the retardation values are shown in Table 2.

[0171] The influence of the pressure-sensitive adhesive layer on the retardation change in the optically anisotropic layer was confirmed in the same manner as above, except that the optical laminate (1) was replaced with the optical laminate (2). The retardation change values before and after durability are shown in Table 2.

[0172] The influence of the pressure-sensitive adhesive layer on the retardation change in the optically anisotropic layer was confirmed in the same manner as above, except that the optical laminate (1) was replaced with the optical laminate (3). The retardation change values before and after durability are shown in Table 2.

[0173] <Measurement of the absorbance of the optical film> The obtained optical laminate (1) was cut into a size of 40 mm × 40 mm, the separator laminated on the adhesive layer (4) was peeled off, and this was bonded to non-alkali glass [product name “EAGLE XG” manufactured by Corning Inc.]. Regarding the obtained measurement sample, using a spectrophotometer with an integrating sphere [product name “V7100” manufactured by JASCO Corporation], the transmittance spectra in the transmission axis direction and absorption axis direction of the optical laminate (1) in the wavelength range of 380 to 780 nm were measured, and the absorbance of the optical laminate (1) at a wavelength of 405 nm was calculated from the transmittance spectrum in the transmission axis direction of the optical laminate (1). Note that the absorbances of the TAC film alone, the COP film alone, and the non-alkali glass alone were all 0 at wavelengths of 350 nm, 405 nm, and 440 nm.

[0174] <Evaluation of Weather Resistance> The optical laminate (1) was placed in a sunshine weather meter (manufactured by Suga Test Instruments Co., Ltd.: model number SUNSHINE WEATHER METER S80) at 63 °C and 50% humidity for 24 hours, and a 24-hour weather resistance test was carried out. The absorbance of the taken-out sample was measured in the same manner as in the above <Measurement of Absorbance of Optical Film>. From the measured absorbance, the absorbance retention rate of the sample at a wavelength of 405 nm was determined based on the following formula. The results are shown in Table 1. The higher the absorbance retention rate, the better the weather resistance with no deterioration of the light selective absorption function. Absorbance retention rate = (A(405) after durability test / A(405) before durability test) × 100

[0175]

Table 2

[0176] When the adhesive layer formed from the adhesive composition containing the resin (A) of the present invention was laminated on the optical film, the retardation change was suppressed. This is presumably because by incorporating a light selective absorption compound having a polymerizable group and an indole structure into the resin, the migration of the light selective absorption compound having an indole structure could be suppressed as compared with the adhesive composition containing only the light selective absorption compound having an indole structure. In addition, the pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition containing the resin (A) of the present invention does not show an increase in the precipitation of the compound even after being subjected to a heat resistance test at 85°C for 120 hours, and has good bleed resistance. Furthermore, the pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition containing the resin (A) of the present invention has a good value of A(405) / A(440).

Industrial Applicability

[0177] The resin of the present invention, the pressure-sensitive adhesive composition containing the resin, the pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition, and the optical laminate containing the pressure-sensitive adhesive layer are suitably used for liquid crystal panels and liquid crystal display devices.

Explanation of Symbols

[0178] 1 Pressure-sensitive adhesive layer 2 Release film 10A, 10B, 10C, 10D Optical laminate 8 Protective film 7 Adhesive layer 7a Pressure-sensitive adhesive layer 9 Polarizing film 30 Light-emitting element 40 Optical film 50, 50a 1 / 4 wavelength retardation layer 60 Adhesive layer or pressure-sensitive adhesive layer 70 1 / 2 wavelength retardation layer 80 Positive C layer 100 Polarizer 110 Retardation film

Claims

1. A resin (A) containing a structural unit having an indole structure in the side chain and at least one structural unit selected from the structural units described in Group A below, wherein the resin (A) satisfies the following formulas (1) and (2), and the structural unit having an indole structure in the side chain is a structural unit derived from a compound represented by formula (III). The resin (A). Group A: A structural unit derived from a (meth)acrylate ester, a structural unit derived from a styrene monomer, a structural unit derived from a vinyl monomer ε(405) ≥ 0.02 (1) [In formula (1), ε(405) represents the gram extinction coefficient of the resin (A) at a wavelength of 405 nm. The unit of the gram extinction coefficient is L / (g·cm).] ε(405) / ε(440) ≥ 5 (2) [In formula (2), ε(405) represents the gram extinction coefficient of the resin (A) at a wavelength of 405 nm, and ε(440) represents the gram extinction coefficient of the resin at a wavelength of 440 nm.] [In formula (III), R １ , R ３ , R ４ , R ５ and R ６ each independently represents a hydrogen atom or an aliphatic hydrocarbon group having 1 to 25 carbon atoms which may have a substituent. E １ represents a cyano group. R ７ represents a hydrogen atom, a cyano group, a methyl group or a phenyl group. Z １ represents -O-R ２Ａ -*1. Z ２ represents *2-O-CO-, *2-O-SO ２ - or *2-NR １Ｃ -CO-. R1C represents a hydrogen atom. R2A represents an alkanediyl group having 1 to 8 carbon atoms. *1 represents a bond with Z ２ and is shown as a bond between them *2 represents a bond with Z １ .

2. The resin according to claim 1, wherein the resin (A) has a glass transition temperature of 40°C or lower.

3. The resin according to claim 1 or 2, wherein the compound represented by formula (III) is a compound satisfying the following formula (1-a). ε(405) ≥ 5 (1-a) [In formula (1-a), ε(405) represents the gram extinction coefficient of a compound having a polymerizable group and an indole structure at a wavelength of 405 nm. The unit of the gram extinction coefficient is L / (g·cm).]

4. The resin according to claim 3, wherein the compound represented by formula (III) is a compound satisfying the following formula (2-a). ε(405) / ε(440) ≥ 10 (2-a) [In formula (2-a), ε(405) represents the gram extinction coefficient of a compound having a polymerizable group and an indole structure at a wavelength of 405 nm, and ε(440) represents the gram extinction coefficient of a compound having a polymerizable group and an indole structure at a wavelength of 440 nm.

5. The resin according to any one of claims 1 to 4, wherein the content of at least one structural unit selected from the structural units described in Group A is 50% by mass or more based on all the structural units of the resin (A).

6. An adhesive composition containing the resin according to any one of claims 1 to 5.

7. The adhesive composition according to claim 6, further containing a crosslinking agent (B).

8. An adhesive layer formed from the adhesive composition according to claim 6 or 7.

9. The pressure-sensitive adhesive layer according to claim 8, which satisfies the following formula (3). A(405) ≧ 0.5 (3) [In formula (3), A(405) represents the absorbance at a wavelength of 405 nm.]

10. Furthermore, the pressure-sensitive adhesive layer according to claim 9, which satisfies the following formula (4). A(405) / A(440) ≧ 5 (4) [In formula (4), A(405) represents the absorbance at a wavelength of 405 nm, and A(440) represents the absorbance at a wavelength of 440 nm.]

11. An optical laminate in which an optical film is laminated on at least one surface of the pressure-sensitive adhesive layer according to any one of claims 8 to 10.

12. The optical laminate according to claim 11, wherein the optical film is a polarizing plate.

13. An image display device including the optical laminate according to claim 12.

14. A compound represented by formula (III) and satisfying the following formulas (1-a) and (2-a). ε(405)≧ 5 (1-a) [In formula (1-a), ε(405) represents the gram extinction coefficient of a compound having a polymerizable group and an indole structure at a wavelength of 405 nm. The unit of the gram extinction coefficient is L / (g·cm).] ε(405) / ε(440)≧ 10 (2-a) [In formula (2-a), ε(405) represents the gram extinction coefficient of a compound having a polymerizable group and an indole structure at a wavelength of 405 nm, and ε(440) represents the gram extinction coefficient of a compound having a polymerizable group and an indole structure at a wavelength of 440 nm.] [In formula (III), R １ , R ３ , R ４ , R ５ , and R ６ each independently represents a hydrogen atom or an aliphatic hydrocarbon group having 1 to 25 carbon atoms which may have a substituent. E １ represents a cyano group. R ７ represents a hydrogen atom, a cyano group, a methyl group or a phenyl group. Z １ represents -O-R ２Ａ -*1. Z ２ represents *2-O-CO-, *2-O-SO ２ -, or *2-NR １Ｃ -CO-. R 1C represents a hydrogen atom. R 2A represents an alkanediyl group having 1 to 8 carbon atoms. *1 represents a bond with Z ２ and is shown as a bond. *2 represents a bond with Z １ .]

15. A resin (A) containing a structural unit having an indole structure in the side chain and at least one structural unit selected from the structural units described in the following Group A, The content of at least one structural unit selected from the structural units described in Group A is 50% by mass or more based on all the structural units of the resin (A), The structural unit having an indole structure in the side chain is a structural unit derived from the compound represented by formula (III), The compound represented by formula (III) satisfies the following formula (1-a) and the following formula (2-a), Resin (A). Group A: A structural unit derived from (meth)acrylate, a structural unit derived from a styrene monomer, a structural unit derived from a vinyl monomer ε(405)≧ 5 (1-a) [In formula (1-a), ε(405) represents the gram extinction coefficient of a compound having a polymerizable group and an indole structure at a wavelength of 405 nm. The unit of the gram extinction coefficient is L / (g·cm).] ε(405) / ε(440) ≥ 10 (2-a) [In formula (2-a), ε(405) represents the gram extinction coefficient of a compound having a polymerizable group and an indole structure at a wavelength of 405 nm, and ε(440) represents the gram extinction coefficient of a compound having a polymerizable group and an indole structure at a wavelength of 440 nm.] [In formula (III), R １ , R ３ , R ４ , R ５ and R ６ each independently represents a hydrogen atom or an aliphatic hydrocarbon group having 1 to 25 carbon atoms which may have a substituent. E １ represents a cyano group. R ７ represents a hydrogen atom, a cyano group, a methyl group or a phenyl group. Z １ represents -O-R ２Ａ -*1. Z ２ represents *2-O-CO-, *2-O-SO ２ - or *2-NR １Ｃ -CO-. R1C represents a hydrogen atom. R2A represents an alkanediyl group having 1 to 8 carbon atoms. *1 represents a bond with Z ２ ​ *2 represents a bond with Z １ .]

16. An adhesive layer formed from an adhesive composition containing a resin (A) containing a structural unit having an indole structure in the side chain and at least one structural unit selected from the structural units described in the following Group A, the adhesive layer satisfies the following formula (3) and the following formula (4), the structural unit having an indole structure in the side chain is a structural unit derived from a compound represented by formula (III), Adhesive layer. Group A: A structural unit derived from a (meth)acrylate ester, a structural unit derived from a styrene monomer, a structural unit derived from a vinyl monomer A(405) ≥ 0.5 (3) [In formula (3), A(405) represents the absorbance at a wavelength of 405 nm.] A(405) / A(440) ≥ 5 (4) [In formula (4), A(405) represents the absorbance at a wavelength of 405 nm, and A(440) represents the absorbance at a wavelength of 440 nm.] [In formula (III), R １ , R ３ , R ４ , R ５ and R ６ each independently represents a hydrogen atom or an aliphatic hydrocarbon group having 1 to 25 carbon atoms which may have a substituent. E １ represents a cyano group. R ７ represents a hydrogen atom, a cyano group, a methyl group or a phenyl group. Z １ represents -O-R ２Ａ -*1. Z ２ represents *2-O-CO-, *2-O-SO ２ - or *2-NR １Ｃ -CO-. R1C represents a hydrogen atom. R2A represents an alkanediyl group having 1 to 8 carbon atoms. *1 represents a bond with Z ２ and is shown as a bond. *2 represents a bond with Z １ .

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