CN112566949B

CN112566949B - Resin and adhesive composition

Info

Publication number: CN112566949B
Application number: CN201980052569.3A
Authority: CN
Inventors: 浅津悠司; 小泽昭一; 国见信孝
Original assignee: Sumitomo Chemical Co Ltd
Current assignee: Sumitomo Chemical Co Ltd
Priority date: 2018-08-09
Filing date: 2019-08-01
Publication date: 2023-06-23
Anticipated expiration: 2039-08-01
Also published as: KR20210041568A; JP2020026528A; TW202017953A; CN112566949A; WO2020031830A1; TWI819053B

Abstract

A resin (A) comprising a structural unit having an indole structure. The resin (a) preferably contains a structural unit having an indole structure in a side chain, and the glass transition temperature is preferably 40 ℃ or lower. The resin (a) is preferably a resin satisfying the formula (1). ε (405) is 0.02 (1) [ in formula (1), ε (405) represents the gram absorption coefficient of resin (A) at 405 nm. The gram absorbance is in units of L/(g.cm). ].

Description

Resin and adhesive composition

Technical Field

The present invention relates to a resin, an adhesive composition containing the resin, and an optical laminate having an adhesive layer formed from the adhesive composition.

Background

Various members such as organic EL elements, display elements such as liquid crystal cells, and optical films such as polarizing plates are used in display devices (FPD: flat panel display) such as organic electroluminescent displays (organic EL display devices) and liquid crystal display devices. Among these members, organic EL light-emitting elements, liquid crystal compounds, and the like are organic substances, and thus deterioration by Ultraviolet (UV) light is liable to be problematic. Further, it has been found that a liquid crystal retardation film and an organic EL light-emitting element obtained by aligning and photo-curing a polymerizable liquid crystal compound have a tendency to deteriorate not only by ultraviolet light but also in visible light having a short wavelength. In order to solve the above-mentioned problems, it is known to provide a layer containing a compound that absorbs light of a 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 containing N-butyl acrylate, 2-hydroxyethyl acrylate and N, N-dimethylacrylamide, and an indole-based ultraviolet absorber.

Prior art literature

Patent literature

Patent document 1: japanese patent laid-open publication No. 2017-48340

Disclosure of Invention

Problems to be solved by the invention

However, it is found that when the adhesive layer containing the ultraviolet absorber described in patent document 1 is made into an optical laminate, deterioration due to ultraviolet light or short-wavelength visible light can be suppressed, but other problems such as deterioration of optical characteristics due to transfer of the ultraviolet absorber to other layers occur. Among them, in the laminate with the liquid crystal phase difference film, it was found that the decrease in optical characteristics (change in phase difference value) caused by the transfer of the ultraviolet absorber to other layers became remarkable.

Means for solving the problems

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 glass transition temperature of the resin (A) is 40℃or lower.

[3] The resin according to [1] or [2], wherein the resin (A) is a resin satisfying the following formula (1).

ε(405)≥0.02 (1)

[ in formula (1),. Epsilon. (405) represents the gram absorbance coefficient of the resin (A) at a wavelength of 405 nm. The gram absorbance is in units of L/(g.cm). ]

[4] The resin according to any one of [1] to [3], wherein the resin (A) is a resin satisfying the following formula (2).

ε(405)/ε(440)≥5 (2)

[ in formula (2), [ epsilon ] (405) represents the gram absorbance coefficient of the resin (A) at a wavelength of 405nm, and [ epsilon ] (440) represents the gram absorbance 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 comprising a structural unit having an indole structure in a side chain.

[6] The resin according to [5], wherein the structural unit having an indole structure in a side chain is a structural unit derived from a light selective absorbing compound having a polymerizable group and an indole structure.

[7] The resin according to [6], wherein the light selective absorbing compound having a polymerizable group and an indole structure is a compound satisfying the following formula (1-a).

ε(405)≥5 (1-a)

[ in the formula (1-a), ε (405) represents the gram absorbance coefficient of a compound having a polymerizable group and an indole structure at a wavelength of 405 nm. The gram absorbance is in units of 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 the formula (2-a), ε (405) represents the gram absorption coefficient of a compound having a polymerizable group and an indole structure at a wavelength of 405nm, and ε (440) represents the gram absorption 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 a side chain is a structural unit derived from a compound represented by formula (I) or a structural unit derived from a compound represented by formula (II).

[ in formula (I), R ¹ 、R ² 、R ³ 、R ⁴ 、R ⁵ R is R ⁶ Each independently represents a hydrogen atom, a heterocyclic group, a halogen atom, a nitro group, a cyano group, a hydroxyl group, a carboxyl 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, wherein the aliphatic hydrocarbon group or the aromatic hydrocarbon group contains-CH ₂ -optionally replaced by-NR ^1A -、-SO ₂ -, -CO-, -O-; -S-or-CF ₂ -。

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 R is R ¹⁷ Each independently represents a hydrogen atom, a heterocyclic group, a halogen atom, a nitro group, a cyano group, a hydroxyl group, a carboxyl 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, wherein the aliphatic hydrocarbon group or the aromatic hydrocarbon group contains-CH ₂ -optionally replaced by-NR ^11A -、-SO ₂ -, -CO-, -O-; -S-or-CF ₂ -。

R ¹¹ 、R ¹³ 、R ¹⁴ 、R ¹⁵ R is R ¹⁶ Each independently represents a hydrogen atom, a heterocyclic group, a halogen atom, a nitro group, a cyano group, a hydroxyl group, a carboxyl group, a group containing a polymerizable group, an aliphatic hydrocarbon group having 1 to 25 carbon atoms which may be substituted, or an aromatic hydrocarbon group having 6 to 18 carbon atoms which may be substituted, the aliphatic hydrocarbon group or the aromatic hydrocarbon group containing-CH ₂ -optionally replaced by-NR ^12A -、-SO ₂ -, -CO-, -O-; -S-or-CF ₂ -。

Wherein R is ¹¹ 、R ¹³ 、R ¹⁴ 、R ¹⁵ R is R ¹⁶ At least one of which represents a group containing a polymerizable group.

R ^11A R is R ^12A Each independently 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 ¹¹ Represents an electron withdrawing group.]

[10]According to [9]]The resin according to, wherein R ² Is phenyl.

[11] The resin according to [9], wherein the compound represented by the formula (I) is a compound represented by the formula (III).

[R ¹ 、R ³ 、R ⁴ 、R ⁵ 、R ⁶ E and E ¹ Meaning the same as 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, an aromatic hydrocarbon group having 6 to 18 carbon atoms and having 2 valencies, -O-R ^2A -*1、-S-R ^2B -1 or (b) -NR ^1D -R ^2C -*1。

Z ² Represents a single bond, # 2-CO-O-, # 2-O-CO-, # 2-S (=o) ₂ -、*2-O-SO ₂ -、*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 -, a part of 2-CO-S-; 2-S-CO-or a perfluoroalkyldi-alkyl group having 1 to 4 carbon atoms.

R ^1B 、R ^1C 、R ^1D 、R ^1E R is 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 R is R ^2F Each independently represents a hydrocarbon group having 1 to 18 carbon atoms and having a valence of 2.

*1 represents a group Z ² Is a bonding end of the (c).

*2 represents and Z ¹ Is a bonding end of the (c).]

[12] The resin according to any one of [1] to [11], wherein the resin (A) further comprises at least 1 structural unit selected from 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)

[ formula, R ^a1 Represents a hydrocarbon group of valence 2.

R ^b1 R is R ^b2 Each independently represents a hydrogen atom or a hydrocarbon group.

R ^c1 R is R ^c2 Each independently represents a hydrocarbyl group of valence 2.]

[13] The resin according to [12], wherein the content of at least 1 structural unit selected from the structural units described in the group A is 50% by mass or more relative to the total structural units of the resin (A).

[14] An adhesive composition comprising the resin according to any one of [1] to [13 ].

[15] The adhesive composition according to [14], which further comprises a crosslinking agent (B).

[16] An adhesive layer formed from the adhesive composition described in [14] or [15 ].

[17] The adhesive layer according to [16], which satisfies the following formula (3).

A(405)≥0.5 (3)

In the formula (3), A (405) represents absorbance at a wavelength of 405 nm. ]

[18] The adhesive layer according to [17], which also satisfies the following formula (4).

A(405)/A(440)≥5 (4)

In the formula (4), A (405) represents absorbance at a wavelength of 405nm, and A (440) represents absorbance at a wavelength of 440 nm. ]

[19] An optical laminate comprising an optical film laminated on at least one of the adhesive layers of 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 comprising the optical laminate according to [20 ].

[22] A compound represented by formula (I) or formula (IV).

E ¹ Represents an electron withdrawing group.

Z represents a linking group.

A represents a polymerizable group.

In the formula (IV), R ¹² R is R ¹⁷ Each independently represents a hydrogen atom, a heterocyclic group, a halogen atom, a nitro group, a cyano group, a hydroxyl group, a carboxyl 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, wherein the aliphatic hydrocarbon group or the aromatic hydrocarbon group contains-CH ₂ -optionally replaced by-NR ^11A -、-SO ₂ -, -CO-, -O-; -S-or-CF ₂ -。

Wherein R is ¹³ 、R ¹⁴ 、R ¹⁵ R is R ¹⁶ At least one of which represents a group containing a polymerizable group.

E ¹¹ Represents an electron withdrawing group.]

[23]According to [22 ]]The compound according to the above, wherein R ² Is phenyl.

[24] The compound according to [22], wherein the compound represented by the formula (I) is a compound represented by the formula (III).

[R ¹ 、R ³ 、R ⁴ 、R ⁵ 、R ⁶ E and E ¹ Meaning the same as above.

R ⁷ Represents a hydrogen atom, cyano, methyl or phenyl.

Z ² Represents a single bond, # 2-CO-O-, # 2-O-CO-, # 2-S (=o) ₂ -、*2-O-SO ₂ -、

*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 -, a part of 2-CO-S-; 2-S-CO-or a perfluoroalkyldi-alkyl group having 1 to 4 carbon atoms.

*1 represents a group Z ² Is a bonding end of the (c).

*2 represents and Z ¹ Is a bonding end of the (c).]

[25]According to [22]]～[24]The compound according to any one of, wherein E ¹ Is cyano.

Effects of the invention

The invention provides an adhesive layer capable of inhibiting degradation of an organic EL light-emitting element and a liquid crystal phase difference film, and an adhesive composition for forming the adhesive layer. Further, a resin capable of forming a binder composition capable of favorably suppressing deterioration of an organic EL light-emitting element and a retardation film is provided.

Drawings

Fig. 1 shows an example of the layer structure of the adhesive layer of the present invention.

Fig. 2 shows an example of the layer structure of the optical laminate of the present invention.

Fig. 3 shows an example of the layer structure of the optical laminate of the present invention.

Fig. 4 shows an example of the layer structure of the optical laminate of the present invention.

Fig. 5 shows an example of the layer structure of the optical laminate of the present invention.

Detailed Description

< 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.

< 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 a light selective absorbing compound having an indole structure.

The glass transition temperature (Tg) of the resin (a) is preferably 40 ℃ or less, more preferably 20 ℃ or less, further preferably 10 ℃ or less, particularly preferably 0 ℃ or less. The glass transition temperature of the resin (A) is usually-80℃or higher, preferably-60℃or higher, and more preferably-50℃or higher. When the glass transition temperature of the resin (a) is 40 ℃ or lower, the adhesion of the adhesive layer formed of the adhesive composition containing the resin (a) to the adherend is advantageously improved. In addition, when the glass transition temperature of the resin (A) is-80℃or higher, it is advantageous to improve the durability of the adhesive layer formed of the adhesive composition containing the resin (A). The glass transition temperature may be measured by a Differential Scanning Calorimeter (DSC).

The resin (a) preferably satisfies the following formula (1).

ε(405)≥0.02(1)

[ in formula (1),. Epsilon. (405) represents the gram absorbance coefficient of the resin at a wavelength of 405 nm. The gram absorbance is in units of L/(g.cm). ]

The gram absorbance coefficient of the resin (a) can be measured by the method described in examples.

The larger the value of ε (405) of resin (A), the more likely it is to absorb light at 405 nm. The value of ε (405) is preferably 0.02L/(g.cm) or more, more preferably 0.1L/(g.cm) or more, still more preferably 0.2L/(g.cm) or more, and usually 10L/(g.cm) or less.

When the 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 epsilon (405) of the resin (a) is 0.02L/(g·cm) or more, the absorption performance of visible light in the vicinity of 400nm is good, and thus deterioration of a retardation film or an organic EL light-emitting element used in the display device such as the organic EL display device or the liquid crystal display device due to visible light can be suppressed.

The resin (a) preferably satisfies the following formula (2).

ε(405)/ε(440)≥5 (2)

In the formula (2), ε (405) represents the gram absorbance coefficient of the resin at 405nm and ε (440) represents the gram absorbance coefficient of the resin at 440 nm. ]

The larger the value of ε (405)/ε (440) of resin (A), the more light with a wavelength around 400nm can be selectively absorbed. The value of ε (405)/ε (440) is preferably 5 or more, more preferably 10 or more, and still more preferably 30 or more.

When ε (405)/ε (440) of resin (A) is 5 or more, light near 400nm can be absorbed without inhibiting color expression of the display device and photodegradation of the retardation film can be suppressed when the adhesive composition containing resin (A) is applied to display devices such as organic EL display devices and liquid crystal display devices.

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 a side chain. The resin (a) preferably contains a structural unit having an indole structure in a side chain.

The structural unit having an indole structure in a 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 the compound having a polymerizable group and an indole structure is preferably a structural unit derived from a light selective absorbing compound having a polymerizable group and an indole structure.

The light selective absorbing compound having a polymerizable group and an indole structure preferably satisfies the following formula (1-a), and even more preferably satisfies the formula (2-a).

ε(405)≥5 (1-a)

ε(405)/ε(440)≥10 (2-a)

[ in the formula (2-a), ε (405) represents the gram absorption coefficient of a compound having a polymerizable group and an indole structure at a wavelength of 405nm, and ε (440) represents the gram absorption coefficient of a compound having a polymerizable group and an indole structure at a wavelength of 440 nm. ]

The value of ε (405) of the compound having a polymerizable group and an indole structure is preferably 5L/(g.cm) or more, more preferably 10L/(g.cm) or more, still more preferably 20L/(g.cm) or more, still more preferably 30L/(g.cm) or more, and usually 500L/(g.cm) or less. The larger the value of ε (405), the more likely the compound absorbs light having a wavelength of 405nm, and the more likely the compound exhibits a function of suppressing deterioration due to ultraviolet light or visible light having a short wavelength.

The value of ε (405)/ε (440) of a compound that has a polymerizable group and an indole structure is preferably 10 or more, more preferably 15 or more. The larger the value of ε (405)/ε (440), the more light near 405nm can be absorbed without disturbing the color appearance of the display device, and the photodegradation of the display device such as a retardation film or an organic EL element can be suppressed.

The structural unit having an indole structure in the side chain is preferably a structural unit derived from a compound represented by formula (I) or a structural unit derived from a compound represented by formula (II), more preferably a structural unit derived from a compound represented by formula (I).

E ¹ Indicating the power absorptionA daughter group.

Z represents a linking group.

A represents a polymerizable group.

E ¹¹ Represents an electron withdrawing group.]

As E ¹ E and E ¹¹ Examples of the electron withdrawing group include a cyano group, a nitro group, a halogen atom, an alkyl group substituted with a halogen atom, a group represented by the formula (I-1), and the like.

^* -X ¹ -R ¹¹¹ (I-1)

[ formula, R ¹¹¹ Represents a hydrogen atom or a hydrocarbon group having 1 to 25 carbon atoms, and at least 1 of methylene groups contained in the alkyl group is optionally replaced 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 (b) -SO ₂ -*3。

R ¹¹² 、R ¹¹³ R is R ¹¹⁴ Each independently represents a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or a phenyl group.

*3 represents and R ¹¹¹ Is a bonding end of the (c).

* Represents the bond end to the carbon atom. ]

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, monofluoroethyl group, monochloromethyl group, monochloroethyl group, monobromomethyl group, monobromoethyl group, monoiodomethyl group, monoiodoethyl group, difluoromethyl group, difluoroethyl group, dichloromethyl group, dichloroethyl group, dibromomethyl group, diiodomethyl group, diiodoethyl group, trifluoromethyl group, trichloromethyl group, tribromomethyl group, and triiodomethyl group. The number of carbon atoms of the alkyl group substituted with a halogen atom is usually 1 to 25.

As R ¹¹¹ Examples of the hydrocarbon group having 1 to 25 carbon atoms include straight-chain or branched alkyl groups having 1 to 25 carbon atoms such as methyl, ethyl, n-propyl, isopropyl, n-butyl, t-butyl, sec-butyl, n-pentyl, isopentyl, n-hexyl, isohexyl, n-octyl, isooctyl, n-nonyl, isononyl, n-decyl, isodecyl, n-dodecyl, isododecyl, undecyl, tetradecyl, hexadecyl, and octadecyl groups: cycloalkyl groups having 3 to 25 carbon atoms such as cyclopropyl, cyclobutyl, cyclopentyl and cyclohexyl; cycloalkylalkyl groups having 4 to 25 carbon atoms such as cyclopropylmethyl and cyclohexylmethyl; aryl groups having 6 to 25 carbon atoms such as phenyl, naphthyl, anthracyl and biphenyl groups; aralkyl groups having 7 to 25 carbon atoms such as benzyl, phenethyl, naphthylmethyl and phenyl groups.

As R ¹¹² 、R ¹¹³ R is R ¹¹⁴ Examples of the alkyl group having 1 to 6 carbon atoms include methyl, ethyl, n-propyl, isopropyl and n-butylTertiary butyl, sec-butyl, and the like.

The linking group represented by Z is not particularly limited as long as it is a 2-valent linking group.

The polymerizable group represented by A is not particularly limited. For example, the compound may be a cationically polymerizable group, an anionically polymerizable group, or a radically polymerizable group. More specifically, an alkynyl group such as an ethynyl group; an epoxy group; oxetanyl; vinyl ether groups; an acrylonitrile group; a methacrylonitrile group; ethylenically unsaturated groups such as vinyl groups, α -methyl vinyl groups, acryl groups, methacryl groups, allyl groups, styryl groups, acrylamide groups, and methacrylamide groups.

As R ¹ ～R ⁶ 、R ¹¹ ～R ¹⁷ Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom.

As R ¹ ～R ⁶ 、R ¹¹ ～R ¹⁷ Examples of the heterocyclic group include a group obtained by removing one hydrogen atom from a heterocyclic ring. Specifically, 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 (Japanese text: a doctor) ring group, a furan ring group, 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 dioxane ring group, an aliphatic heterocyclic group having 4 to 30 carbon atoms such as a cyclic furan (Japanese text) ring group, a pyrazine ring group, a purine ring group, an aromatic heterocyclic group having 3 to 20 carbon atoms, and the like can be exemplified. These heterocyclic groups may be hydrogenated or may have a structure in which a cyclic skeleton is further condensed (for example, a benzomidale ring (a benzoimidazole ring, a benzimidazole ring), or a structure in which a hydrogen atom on a heterocyclic ring is further substituted with a heterocyclic group, a halogen atom, a nitro group, a cyano group, a hydroxyl group, a carboxyl group, or the like).

As R ¹ ～R ⁶ 、R ¹¹ ～R ¹⁷ Shown in the figureExamples of the aliphatic hydrocarbon group having 1 to 25 carbon atoms include straight-chain or branched alkyl groups having 1 to 25 carbon atoms such as methyl, ethyl, n-propyl, isopropyl, n-butyl, t-butyl, sec-butyl, n-pentyl, isopentyl, n-hexyl, isohexyl, n-octyl, isooctyl, n-nonyl, isononyl, n-decyl, isodecyl, n-dodecyl, isododecyl, undecyl, tetradecyl, hexadecyl, and octadecyl groups: cycloalkyl groups having 3 to 25 carbon atoms such as cyclopropyl, cyclobutyl, cyclopentyl and cyclohexyl; cycloalkyl alkyl groups having 4 to 25 carbon atoms such as cyclopropylmethyl and cyclohexylmethyl are preferable from the viewpoint of solubility, and branched alkyl groups having 3 to 25 carbon atoms such as 2-ethylhexyl and 2-butyloctyl are preferable.

As R ¹ ～R ⁶ 、R ¹¹ ～R ¹⁷ Examples of the substituent optionally contained in the aliphatic hydrocarbon group having 1 to 25 carbon atoms include a heterocyclic group, a halogen atom, a nitro group, a cyano group, a hydroxyl group, a carboxyl group, an acetamido group, an amino group, and an alkylamino group having 1 to 12 carbon atoms. Examples of the heterocyclic group include a heterocyclic group represented by R ¹ The heterocyclic groups shown are identical.

As R ¹ ～R ⁶ 、R ¹¹ ～R ¹⁷ Examples of the aromatic hydrocarbon group having 6 to 18 carbon atoms include aryl groups having 6 to 18 carbon atoms such as phenyl, naphthyl, anthracenyl, biphenyl and methylphenyl; aralkyl groups having 7 to 18 carbon atoms such as benzyl, phenylethyl, naphthylmethyl and phenoxy groups. As R ¹ ～R ⁶ 、R ¹¹ ～R ¹⁷ the-CH group contained in the aromatic hydrocarbon group having 6 to 18 carbon atoms ₂ -from-SO ₂ -, -CO-, -O-; -S-or-CF ₂ Examples of the substituted group include aryloxy groups such as phenoxy and naphthoxy. From the viewpoint of wavelength selectivity, R is ¹ ～R ⁶ 、R ¹¹ ～R ¹⁷ The aromatic hydrocarbon group having 6 to 18 carbon atoms is preferably an aralkyl group having 7 to 18 carbon atoms or an aryloxy group having 6 to 18 carbon atoms, more preferably a benzyl group or an aryloxy group having 6 to 18 carbon atoms.

As R ¹ ～R ⁶ 、R ¹¹ ～R ¹⁷ Examples of the substituent optionally contained in the aromatic hydrocarbon group having 6 to 18 carbon atoms include a heterocyclic group, a halogen atom, a nitro group, a cyano group, a hydroxyl group, a carboxyl group, an acetamido group, an amino group, and an alkylamino group having 1 to 12 carbon atoms. Examples of the heterocyclic group include a heterocyclic group represented by R ¹ The heterocyclic groups shown are identical.

As R ¹¹ 、R ¹³ 、R ¹⁴ 、R ¹⁵ R is R ¹⁶ The group containing a polymerizable group is not particularly limited as long as it has a polymerizable group at the terminal, but specifically, a group represented by the formula (I-2) is exemplified.

*-R ¹¹⁵ -X ² (I-2)

[ in formula (I-2), X ² Represents a polymerizable group.

R ¹¹⁵ Represents an alkanediyl group having 1 to 12 carbon atoms, which alkanediyl group contains-CH ₂ -optionally replaced by-O-, -CO-, -CS-, or-NR ¹¹⁶ -。

R ¹¹⁶ Represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms.

* Represents the bond end to a carbon atom or a nitrogen atom. ]

As X ² The polymerizable group shown in the drawing may be the same as the polymerizable group shown in A, and is preferably an ethylenically unsaturated group such as a vinyl group, an α -methyl vinyl group, an acryl group, a methacryl group, an allyl group, a styryl group, an acrylamide group, or a methacrylamide group.

As R ¹¹⁵ Examples of the alkanediyl group having 1 to 12 carbon atoms include methylene, ethylene, propane-1, 3-diyl, butane-1, 4-diyl, pentane-1, 5-diyl, hexane-1, 6-diyl, ethane-1, 1-diyl, propane-1, 2-diyl, butane-1, 3-diyl, 2-methylpropane-1, 2-diyl, pentane-1, 4-diyl, and 2-methylbutane-1, 4-diyl.

As R ¹¹⁶ The alkyl group having 1 to 6 carbon atoms is exemplified by R ¹¹² The alkyl groups having 1 to 6 carbon atoms are the same.

R ¹¹ 、R ¹³ 、R ¹⁴ 、R ¹⁵ R is R ¹⁶ At least one of which represents a group containing a polymerizable group.

Preferably R ¹³ 、R ¹⁴ 、R ¹⁵ R is R ¹⁶ At least one of them is a group containing a polymerizable group, more preferably R ¹³ 、R ¹⁴ 、R ¹⁵ Or R is ¹⁶ Is a group containing a polymerizable group.

R ² The aromatic hydrocarbon group or heterocyclic group having 6 to 18 carbon atoms is preferable, and the aromatic hydrocarbon group having 6 to 18 carbon atoms or the aromatic heterocyclic group having 3 to 20 carbon atoms is more preferable.

The polymerizable group represented by A is preferably an ethylenically unsaturated group.

E ¹ E and E ¹¹ Preferably each independently is cyano.

The compound represented by the formula (I) is preferably a compound represented by the formula (III).

[R ¹ 、R ³ 、R ⁴ 、R ⁵ 、R ⁶ E and E ¹ Meaning the same as above.

R ⁷ Represents a hydrogen atom, cyano, methyl or phenyl.

*1 represents a group Z ² Is a bonding end of the (c).

*2 represents and Z ¹ Is a bonding end of the (c).]

As Z ¹ Examples of the alkanediyl group having 1 to 12 carbon atoms include the following groups R ¹¹⁵ The alkyl groups having 1 to 12 carbon atoms are the same.

As Z ¹ Examples of the 2-valent aromatic hydrocarbon group having 6 to 18 carbon atoms include phenylene and naphthylene.

As R ^1B 、R ^1C 、R ^1D 、R ^1E R is R ^1F The alkyl group having 1 to 6 carbon atoms is exemplified by R ¹¹² The alkyl groups having 1 to 6 carbon atoms are the same.

As R ^2A 、R ^2B 、R ^2C 、R ^2D 、R ^2E R is R ^2F Examples of the 2-valent hydrocarbon group having 1 to 18 carbon atoms include alkanediyl groups having 1 to 18 carbon atoms such as methylene, ethylene, propane-1, 3-diyl, butane-1, 4-diyl, pentane-1, 5-diyl and hexane-1, 6-diyl, ethane-1, 1-diyl, propane-1, 2-diyl, butane-1, 3-diyl, 2-methylpropane-1, 2-diyl, pentane-1, 4-diyl and 2-methylbutane-1, 4-diyl; and 2-valent aromatic hydrocarbon groups having 6 to 18 carbon atoms such as phenylene and naphthylene.

Z ¹ preferably-O-R ^2A -1 (more) preferably R ^2A An alkanediyl group having 1 to 8 carbon atoms is more preferable, and an alkanediyl group having 4 to 8 carbon atoms is further preferable.

Z ² Preferably, it is 2-O-CO-, 2-O-SO ₂ -、*2-NR ^1C -CO- (more preferably R) ^1C Is a hydrogen atom).

The compound represented by the formula (II) is preferably a compound represented by the formula (IV).

[R ¹¹ 、R ¹² 、R ¹³ 、R ¹⁴ 、R ¹⁵ 、R ¹⁶ 、R ¹⁷ E and E ¹¹ Meaning the same as above. Wherein R is ¹³ 、R ¹⁴ 、R ¹⁵ R is R ¹⁶ At least one of which represents a group containing a polymerizable group.]

The compound represented by the formula (I) may be the following compound.

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The compound represented by the formula (II) may be a compound described below.

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The compound represented by the formula (I) wherein A is an ethylenically unsaturated group can be obtained, for example, by reacting a compound represented by the formula (Ia) with a compound represented by the formula (c 1).

[ R in formula (Ia) ¹ 、R ² 、R ³ 、R ⁴ 、R ⁵ 、R ⁶ E and E ¹ Meaning the same as above. Z in formula (c) ³ Represents a 2-valent linking group, A ¹ Represents an ethylenically polymerizable group.]

The amount of the compound represented by the formula (c 1) to be used is preferably 0.5 to 5 mol based on 1 mol of the compound represented by the formula (Ia).

The reaction of the compound represented by the formula (Ia) with the compound represented by the formula (c 1) can be carried out using a known esterification reaction, preferably in the presence of a base and a carbodiimide condensing agent. Examples of the base include triethylamine, diisopropylethylamine, pyridine, piperidine, pyrrolidine, proline, and N, N-dimethylaminopyridine. Examples of the carbodiimide condensing agent include N, N-dicyclohexylcarbodiimide, N-diisopropylcarbodiimide, and 1-ethyl-3- (3-dimethylaminopropyl) carbodiimide hydrochloride. The amount of the base to be used is preferably 0.001 to 0.5 mol based on 1 mol of the compound represented by the formula (Ia). The amount of the carbodiimide condensing agent to be used is preferably 0.5 to 5 mol based on 1 mol of the compound represented by the formula (Ia).

The reaction of the compound represented by formula (Ia) with the compound represented by formula (c 1) is preferably carried out in an organic solvent. Examples of the organic solvent include toluene, acetonitrile, methylene chloride, and chloroform.

In order to inhibit the reaction between the ethylenically unsaturated groups contained in the compound represented by the formula (c 1), a polymerization inhibitor may be added. Examples of the polymerization inhibitor include 2, 6-di-t-butyl-4-methylphenol (BHT) and 4-methoxyphenol.

The reaction of the compound represented by formula (Ia) with the compound represented by (c 1) is carried out by mixing the compound represented by formula (Ia) with the compound represented by (c 1).

The reaction temperature of the compound represented by the formula (Ia) and the compound represented by the formula (c 1) is preferably-20 to 120℃and the reaction time is usually preferably 1 to 50 hours.

The compound represented by the formula (Ia) may be a compound described below.

Examples of the compound represented by the formula (c 1) include 4-hydroxybutyl acrylate and 2-hydroxyethyl acrylate.

The compound represented by the formula (Ia) can be obtained by reacting a compound represented by the formula (Ib) with a compound represented by the formula (c 2).

[ R in the formula ] ¹ 、R ² 、R ³ 、R ⁴ 、R ⁵ 、R ⁶ E and E ¹ Meaning the same as above.]

The amount of the compound represented by the formula (c 2) to be used is preferably 0.5 to 5 mol based on 1 mol of the compound represented by the formula (Ib).

The reaction of the compound represented by the formula (Ib) with the compound represented by the formula (c 2) 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 to be used is preferably 0.5 to 5 mol based on 1 mol of the compound represented by the formula (Ib).

The reaction of the compound represented by the formula (Ib) with the compound represented by the formula (c 2) is preferably carried out in an organic solvent. Examples of the organic solvent include acetonitrile, isopropanol, toluene, chloroform, and methylene chloride.

The reaction of the compound represented by formula (Ib) with the compound represented by (c 2) is carried out by mixing the compound represented by formula (Ia) with the compound represented by (c 1).

The reaction temperature of the compound represented by the formula (Ia) and the compound represented by the formula (c 1) is preferably 0 to 120℃and the reaction time is usually preferably 1 to 50 hours.

The resin (a) may be a homopolymer having a structural unit having an indole structure, or may be a copolymer having a structural unit having an indole structure and other structural units. The resin (A) is preferably a copolymer.

The resin (a) may contain a structural unit other than the structural unit having an indole structure, and examples thereof include the structural units described in the following group a.

[ formula, R ^a1 Represents a hydrocarbon group of valence 2.

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, and stearyl (meth) acrylate;

branched alkyl esters of (meth) acrylic acid such as isopropyl (meth) acrylate, isobutyl (meth) acrylate, t-butyl (meth) acrylate, isopentyl (meth) acrylate, isohexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, isooctyl (meth) acrylate, isononyl (meth) acrylate, isostearyl (meth) acrylate, and isopentyl (meth) acrylate;

Alicyclic skeleton-containing alkyl esters of (meth) acrylic acid such as cyclohexyl (meth) acrylate, isobornyl (meth) acrylate, adamantyl (meth) acrylate, dicyclopentyl (meth) acrylate, cyclododecyl (meth) acrylate, methylcyclohexyl (meth) acrylate, trimethylcyclohexyl (meth) acrylate, t-butylcyclohexyl (meth) acrylate, and α -ethoxycyclohexyl acrylate;

esters of (meth) acrylic acid having an aromatic ring skeleton such as phenyl (meth) acrylate; etc.

The structural unit derived from a (meth) acrylic acid ester may be a substituent-containing alkyl (meth) acrylate in which a substituent is introduced into the alkyl group of the alkyl (meth) acrylate. The substituent of the alkyl (meth) acrylate having a substituent is a group substituted for a hydrogen atom of an alkyl group, and specific examples thereof include a phenyl group, an alkoxy group, and a phenoxy group. Specific examples of the alkyl (meth) acrylate having a substituent include 2-methoxyethyl (meth) acrylate, ethoxymethyl (meth) acrylate, phenoxyethyl (meth) acrylate, 2- (2-phenoxyethoxy) ethyl (meth) acrylate, phenoxydiethylene glycol (meth) acrylate, and phenoxypoly (ethylene glycol) acrylate.

These (meth) acrylates may be used singly or in various combinations.

The resin (a) of the present invention preferably contains a constituent unit derived from an alkyl (meth) acrylate (a 1) having a glass transition temperature Tg of less than 0 ℃ of a homopolymer of the alkyl (meth) acrylate and a constituent unit derived from an alkyl (meth) acrylate (a 2) having a Tg of 0 ℃ or more of the homopolymer. This is advantageous in improving the high temperature durability of the adhesive layer. For example, the Tg of a homopolymer of an alkyl (meth) acrylate may be a value reported in the literature such as POLYMER HANDBOOK (Wiley-Interscience).

Specific examples of the alkyl (meth) acrylate (a 1) include alkyl (meth) acrylates having about 2 to 12 carbon atoms in the alkyl group such as ethyl acrylate, n-and i-propyl acrylate, n-and i-butyl acrylate, n-pentyl acrylate, n-and i-hexyl acrylate, n-heptyl acrylate, n-and i-octyl acrylate, 2-ethylhexyl acrylate, n-and i-nonyl acrylate, n-and i-decyl acrylate, n-dodecyl acrylate and the like.

The alkyl (meth) acrylate (a 1) may be used alone or in combination of 2 or more. Among them, n-butyl acrylate, n-octyl acrylate, 2-ethylhexyl acrylate, and the like are preferable from the viewpoints of follow-up property and reworkability when laminated on an optical film.

The alkyl (meth) acrylate (a 2) is an alkyl (meth) acrylate other than the alkyl (meth) acrylate (a 1). Specific examples of the alkyl (meth) acrylate (a 2) include methyl acrylate, cyclohexyl acrylate, isobornyl acrylate, octadecyl acrylate, t-butyl acrylate, and the like.

The alkyl (meth) acrylate (a 2) may be used in an amount of 1 or 2 or more. Among them, from the viewpoint of high temperature durability, the alkyl (meth) acrylate (a 2) preferably contains methyl acrylate, cyclohexyl acrylate, isobornyl acrylate, and the like, and more preferably contains methyl acrylate.

Further, as the structural unit derived from the (meth) acrylate, a structural unit derived from a (meth) acrylate having a polar functional group may be mentioned.

As the (meth) acrylate monomer having a polar functional group, there may be mentioned:

1-hydroxymethyl (meth) acrylate, 1-hydroxyethyl (meth) acrylate, 1-hydroxyheptyl (meth) acrylate, 1-hydroxybutyl (meth) acrylate, 1-hydroxypentyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 2-hydroxypentyl (meth) acrylate, 2-hydroxyhexyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 3-hydroxybutyl (meth) acrylate, 3-hydroxypentyl (meth) acrylate, 3-hydroxyhexyl (meth) acrylate, 3-hydroxyheptyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 4-hydroxypentyl (meth) acrylate, 4-hydroxyhexyl (meth) acrylate, 4-hydroxyheptyl (meth) acrylate, 4-hydroxyoctyl (meth) acrylate, 2-chloro-2-hydroxypropyl (meth) acrylate, 3-chloro-2-hydroxypropyl (meth) acrylate, 2-hydroxy-phenoxy (meth) acrylate, 3-hydroxy-propyl (meth) acrylate, 5-hydroxy-hexyl (meth) acrylate, 5-hydroxyheptyl (meth) acrylate, 5-hydroxyoctyl (meth) acrylate, 5-hydroxynonyl (meth) acrylate, 6-hydroxyhexyl (meth) acrylate, 6-hydroxyheptyl (meth) acrylate, 6-hydroxyoctyl (meth) acrylate, 6-hydroxynonyl (meth) acrylate, 6-hydroxydecyl (meth) acrylate, 7-hydroxyheptyl (meth) acrylate, 7-hydroxyoctyl (meth) acrylate, 7-hydroxynonyl (meth) acrylate, 7-hydroxydecyl (meth) acrylate, 7-hydroxyundecyl (meth) acrylate, 8-hydroxyoctyl (meth) acrylate, 8-hydroxynonyl (meth) acrylate, 8-hydroxydecyl (meth) acrylate, 8-hydroxyundecyl (meth) acrylate, 8-hydroxydodecyl (meth) acrylate, 9-hydroxynonyl (meth) acrylate, 9-hydroxydecyl (meth) acrylate, 9-hydroxyundecyl (meth) acrylate, 9-hydroxydodecyl (meth) acrylate, 9-hydroxytridecyl (meth) acrylate, 10-hydroxyundecyl (meth) acrylate, and hydroxy-containing (meth) acrylic esters such as 10-hydroxydodecyl (meth) acrylate, 10-hydroxytridecyl (meth) acrylate, 10-hydroxytetradecyl (meth) acrylate, 11-hydroxyundecyl (meth) acrylate, 11-hydroxydodecyl (meth) acrylate, 11-hydroxytridecyl (meth) acrylate, 11-hydroxytetradecyl (meth) acrylate, 11-hydroxypentadecyl (meth) acrylate, 12-hydroxydodecyl (meth) acrylate, 12-hydroxytridecyl (meth) acrylate, 12-hydroxytetradecyl (meth) acrylate, 13-hydroxypentadecyl (meth) acrylate, 13-hydroxytetradecyl (meth) acrylate, 13-hydroxypentadecyl (meth) acrylate, 14-hydroxytetradecyl (meth) acrylate, 15-hydroxypentadecyl (meth) acrylate, and 15-hydroxypentadecyl (meth) acrylate.

The styrene monomer may be styrene; alkylstyrenes such as methylstyrene, dimethylstyrene, trimethylstyrene, ethylstyrene, diethylstyrene, triethylstyrene, propylstyrene, butylstyrene, hexylstyrene, heptylstyrene, octylstyrene and the like; halogenated styrenes such as fluorostyrene, chlorostyrene, bromostyrene, dibromostyrene, and iodostyrene; nitrostyrene; acetyl styrene; methoxystyrene; divinylbenzene.

Examples of the vinyl monomer include fatty acid vinyl esters such as vinyl acetate, vinyl propionate, vinyl butyrate, vinyl 2-ethylhexanoate, and vinyl laurate; vinyl halides such as vinyl chloride and vinyl bromide; vinylidene chloride and other vinylidene halides; nitrogen-containing heteroaromatic vinyl compounds such as vinylpyridine, vinylpyrrolidone and vinylcarbazole; conjugated dienes such as butadiene, isoprene and chloroprene; unsaturated nitriles such as acrylonitrile and methacrylonitrile.

The epoxy compound is a compound having an epoxy group in a molecule. The epoxy group may be an alicyclic ring-bonded epoxy group such as a cyclopentane epoxide structure or cyclohexane epoxide structure.

Examples of the epoxy compound include 3, 4-epoxycyclohexylmethyl 3, 4-epoxycyclohexane carboxylate, 3, 4-epoxy-6-methylcyclohexylmethyl 3, 4-epoxy-6-methylcyclohexane carboxylate, ethylenebis (3, 4-epoxycyclohexane carboxylate), 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-diglycidyl-7, 11, 18, 21-tetraoxatrispir [5.2.2.5.2.2] hene, 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-diglycidyl ether, 1, 6-hexanediol diglycidyl ether, neopentyl glycol, triglycidyl ether, tetraglycidyl ether, and triglycidyl ether.

The compound from which the structural unit represented by the formula (a) is derived can be synthesized, for example, by the reaction of a diisocyanate compound and a polyol.

The compound from which the structural unit represented by the formula (b) is derived can be synthesized, for example, by reacting a halosilane with a silane having a hydroxyl group.

The compound from which the structural unit represented by the formula (c) is derived can be synthesized, for example, by a reaction between a polycarboxylic acid and a polyol.

The structural unit selected from the structural units described in group a is preferably a structural unit derived from (meth) acrylate. The structural unit derived from a (meth) acrylic acid ester is preferably an alkyl (meth) acrylate or an alkyl (meth) acrylate having a hydroxyl group.

The resin (a) of the present invention may further contain other structural units (sometimes referred to as structural units (aa)). Specifically, the structural unit derived from a (meth) acrylamide monomer, the structural unit derived from a monomer having a carboxyl group, the structural unit derived from a monomer having a heterocyclic group, the structural unit derived from a monomer having a substituted or unsubstituted amino group, and the like can be cited.

Examples of the (meth) acrylamide monomer 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-dimethyl (meth) acrylamide, 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 ] -acrylamide, 2-acrylamido-2-methyl-1-propanesulfonic acid, N- (methoxymethyl) (meth) acrylamide, N- (propoxymethyl) (meth) acrylamide, N- (1-methylethoxymethyl) (meth) acrylamide, N- (1-methylpropoxy methyl) (meth) acrylamide, N- (2-methylpropoxy methyl) (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 ] -acrylamide, N- [ 2- (1-methylpropoxy) ethyl ] -acrylamide, N- [ 2- (2-methylpropoxy) ethyl ] -acrylamide, N- (2-butoxyethyl) (meth) acrylamide, N- [ 2- (1, 1-dimethylethoxy) ethyl ] -acrylamide, and the like. Among them, N- (methoxymethyl) acrylamide, N- (ethoxymethyl) acrylamide, N- (propoxymethyl) acrylamide, N- (butoxymethyl) acrylamide, and N- (2-methylpropoxymethyl) acrylamide are preferable.

Examples of the monomer having a carboxyl group include (meth) acrylic acid, carboxyalkyl (meth) acrylate (for example, carboxyethyl (meth) acrylate, carboxypentyl (meth) acrylate), maleic acid, maleic anhydride, fumaric acid, and crotonic acid, and acrylic acid is preferable.

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, and 2, 5-dihydrofuran.

Examples of the monomer having a substituted or unsubstituted amino group include aminoethyl (meth) acrylate, N-dimethylaminoethyl (meth) acrylate, dimethylaminopropyl (meth) acrylate, and the like.

The structural unit having an indole structure and the structural unit (aa) other than the structural unit selected from group a are preferably monomers having a carboxyl group.

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 even more preferably 0.5 to 15 parts by mass, based on 100 parts by mass of the total structural units contained in the resin (a).

The content of at least 1 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, based on 100 parts by mass of the total structural units of the resin (a).

When the resin (a) contains the structural unit (aa), the amount 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 the total structural units of the resin (a).

When the resin (a) contains a structural unit derived from an alkyl (meth) acrylate having a hydroxyl 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, relative to 100 parts by mass of the total structural units of the resin (a).

From the viewpoint of preventing the release force of the release film that can be laminated on the outer surface of the adhesive layer formed from the adhesive composition from increasing, it is preferable that the release film contains substantially no monomer having an amino group. The term "substantially not including the monomer having an amino group" as used herein means that the content of the structural unit derived from the monomer having an amino group is 0.1 part by mass or less based on 100 parts by mass of the total of the constituent units constituting the resin (a).

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

The weight average molecular weight (Mw) of the resin (A) of the present invention is preferably 30 to 250 tens of thousands, more preferably 50 to 200 tens of thousands. When the weight average molecular weight is 30 ten thousand or more, the durability of the adhesive layer in a high-temperature environment is improved, and defects such as peeling between the adherend and the adhesive layer, cohesive failure of the adhesive layer, and the like are easily suppressed. When the weight average molecular weight is 250 ten thousand or less, the adhesive composition is advantageous from the viewpoint of coatability when processed into, for example, a sheet form (coated on a substrate). The weight average molecular weight is preferably 60 to 180 ten thousand, more preferably 70 to 170 ten thousand, and even more preferably 100 to 160 ten thousand, from the viewpoint of both the durability of the pressure-sensitive adhesive layer and the coatability of the pressure-sensitive adhesive composition. The molecular weight distribution (Mw/Mn) expressed as the ratio of the weight average molecular weight (Mw) to the number average molecular weight (Mn) is usually 2 to 10, preferably 3 to 8. The weight average molecular weight can be analyzed by gel permeation chromatography and is a value converted to standard polystyrene.

When the resin (A) of the present invention is dissolved in ethyl acetate to prepare a solution having a concentration of 20% by mass, the viscosity at 25℃is preferably 20 Pa.s or less, more preferably 0.1 to 15 Pa.s. If the viscosity is in this range, the adhesive composition is advantageous from the viewpoint of coatability when applied to a substrate. The viscosity may be measured by a brookfield viscometer.

The resin (a) of the present invention can be produced by a known method such as a solution polymerization method, a bulk polymerization method, a suspension polymerization method, or an emulsion polymerization method, and particularly, a solution polymerization method is preferable. The solution polymerization method includes, for example, a method in which a monomer having an indole structure, a monomer having a structural unit described in the lead-out group a, which is used 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 about 40 to 90 ℃, preferably about 50 to 80 ℃ for about 3 to 15 hours. In order to control the reaction, the monomer and the thermal polymerization initiator may be continuously or intermittently added during the polymerization. The monomer and the thermal initiator may be added to the organic solvent.

As the polymerization initiator, a thermal polymerization initiator, a photopolymerization initiator, or the like is used. Examples of the photopolymerization initiator include 4- (2-hydroxyethoxy) phenyl (2-hydroxy-2-propyl) ketone and the like. Examples of the thermal polymerization initiator include azo compounds such as 2,2' -azobisisobutyronitrile, 2' -azobis (2-methylbutyronitrile), 1' -azobis (cyclohexane-1-carbonitrile), 2' -azobis (2, 4-dimethylvaleronitrile), 2' -azobis (2, 4-dimethyl-4-methoxyvaleronitrile), dimethyl 2,2' -azobis (2-methylpropionate) and 2,2' -azobis (2-hydroxymethylpropionitrile); organic peroxides such as lauroyl peroxide, t-butylhydroperoxide, benzoyl peroxide, t-butylperoxybenzoate, cumene hydroperoxide, diisopropyl peroxydicarbonate, dipropyl peroxydicarbonate, t-butylperoxyneodecanoate, t-butylperoxypivalate, and (3, 5-trimethylhexanoyl) peroxide; inorganic peroxides such as potassium persulfate, ammonium persulfate, and hydrogen peroxide. In addition, a redox initiator or the like using a combination of a peroxide and a reducing agent may be used.

The proportion of the polymerization initiator is about 0.001 to 5 parts by mass based on 100 parts by mass of the total amount of the monomers constituting the resin (a). The polymerization of the resin (a) may be carried out by an active energy ray (for example, ultraviolet ray or the like).

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 propanol and isopropanol; ketones such as acetone, methyl ethyl ketone and methyl isobutyl ketone.

The content of the resin (a) is usually 60 to 99.99 mass%, preferably 70 to 99.9 mass%, and more preferably 80 to 99.7 mass% based on 100 mass% of the solid content of the adhesive composition.

Cross-linking agent (B) >, and method for producing the same

The adhesive composition of the present invention may 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, and the like, and isocyanate-based crosslinking agents are preferable from the viewpoints of usable time (japanese text) of the adhesive composition, durability of the adhesive layer, crosslinking speed, and the like.

The isocyanate compound is preferably a compound having at least 2 isocyanate groups (-NCO) in the molecule, and examples thereof include aliphatic isocyanate compounds (e.g., hexamethylene diisocyanate, etc.), alicyclic isocyanate compounds (e.g., isophorone diisocyanate, hydrogenated diphenylmethane diisocyanate, hydrogenated xylylene diisocyanate), aromatic isocyanate compounds (e.g., toluene diisocyanate, xylylene diisocyanate, diphenylmethane diisocyanate, naphthalene diisocyanate, triphenylmethane triisocyanate, etc.), and the like. The crosslinking agent (B) may be a derivative of the isocyanate compound such as an adduct (adduct) of the isocyanate compound with a polyol compound [ for example, an adduct of glycerin, trimethylolpropane or the like ], an isocyanurate compound, a biuret compound, or a urethane prepolymer type isocyanate compound obtained by an addition reaction with a polyether polyol, a polyester polyol, an acrylic polyol, a polybutadiene polyol, a polyisoprene polyol or the like. The crosslinking agent (B) may be used singly or in combination of two or more. Of these, typical examples include aromatic isocyanate compounds (e.g., toluene diisocyanate and xylylene diisocyanate), aliphatic isocyanate compounds (e.g., hexamethylene diisocyanate), adducts of these compounds using a polyol compound (e.g., glycerol and trimethylolpropane), and isocyanurate. If the crosslinking agent (B) is an aromatic isocyanate compound and/or an adduct thereof using a polyol compound or an isocyanurate, it is possible to improve the durability of the adhesive layer because it is advantageous to form an optimum crosslinking density (or crosslinking structure). In particular, if the adhesive layer is a toluene diisocyanate compound and/or an adduct of these compounds using a polyol compound, durability can be improved even if the adhesive layer is applied to a polarizing plate or the like, for example.

The content of the crosslinking agent (B) is usually 0.01 to 15 parts by mass, preferably 0.05 to 10 parts by mass, more preferably 0.1 to 5 parts by mass, based on 100 parts by mass of the resin (a).

The 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-glycidoxypropyl trimethoxysilane, 3-glycidoxypropyl triethoxysilane, 3-glycidoxypropyl methyldimethoxysilane, 3-glycidoxypropyl ethoxydimethylsilane, 2- (3, 4-epoxycyclohexyl) ethyltrimethoxysilane, 3-chloropropylmethyldimethoxysilane, 3-chloropropyltrimethoxysilane, 3-methacryloxypropyl trimethoxysilane, and 3-mercaptopropyl trimethoxysilane.

The silane compound (D) may be a silicone oligomer. Specific examples of the silicone oligomer are described as combinations of monomers, as follows.

Mercaptopropyl-containing oligomers such as 3-mercaptopropyl trimethoxysilane-tetramethoxysilane oligomer, 3-mercaptopropyl trimethoxysilane-tetraethoxysilane oligomer, 3-mercaptopropyl triethoxysilane-tetramethoxysilane oligomer, and 3-mercaptopropyl triethoxysilane-tetraethoxysilane oligomer; mercaptomethyl trimethoxysilane-tetramethoxysilane oligomer, mercaptomethyl trimethoxysilane-tetraethoxysilane oligomer, mercaptomethyl triethoxysilane-tetramethoxysilane oligomer, mercaptomethyl triethoxysilane-tetraethoxysilane oligomer and other mercaptomethyl-containing oligomers; 3-epoxypropyl group-containing copolymers such as 3-epoxypropyl trimethoxysilane-tetramethoxysilane copolymer, 3-epoxypropyl trimethoxysilane-tetraethoxysilane copolymer, 3-epoxypropyl triethoxysilane-tetramethoxysilane copolymer, 3-epoxypropyl triethoxysilane-tetraethoxysilane copolymer, 3-epoxypropyl methyldimethoxysilane-tetramethoxysilane copolymer, 3-epoxypropyl methyldimethoxysilane-tetraethoxysilane copolymer, 3-epoxypropyl methyldiethoxysilane-tetramethoxysilane copolymer, 3-epoxypropyl methyldiethoxysilane-tetraethoxysilane copolymer, and 3-epoxypropyl methyldiethoxysilane-tetraethoxysilane copolymer; methacryloxypropyl-containing oligomers such as 3-methacryloxypropyl trimethoxysilane-tetramethoxysilane oligomer, 3-methacryloxypropyl trimethoxysilane-tetraethoxysilane oligomer, 3-methacryloxypropyl triethoxysilane-tetraethoxysilane oligomer, 3-methacryloxypropyl methyldimethoxysilane-tetramethoxysilane oligomer, 3-methacryloxypropyl methyldimethoxysilane-tetraethoxysilane oligomer, 3-methacryloxypropyl methyldiethoxysilane-tetramethoxysilane oligomer, 3-methacryloxypropyl methyldiethoxysilane-tetraethoxysilane oligomer, and 3-methacryloxypropyl methyldiethoxysilane-tetraethoxysilane oligomer; an acryloxypropyl group-containing oligomer such as a 3-acryloxypropyl trimethoxysilane-tetramethoxysilane oligomer, a 3-acryloxypropyl trimethoxysilane-tetraethoxysilane oligomer, a 3-acryloxypropyl triethoxysilane-tetraethoxysilane oligomer, a 3-acryloxypropyl methyldimethoxysilane-tetramethoxysilane oligomer, a 3-acryloxypropyl methyldimethoxysilane-tetraethoxysilane oligomer, a 3-acryloxypropyl methyldiethoxysilane-tetramethoxysilane oligomer, a 3-acryloxypropyl methyldiethoxysilane-tetraethoxysilane oligomer, or the like; vinyl-containing oligomers such as vinyltrimethoxysilane-tetramethoxysilane oligomer, vinyltrimethoxysilane-tetraethoxysilane oligomer, vinyltriethoxysilane-tetramethoxysilane oligomer, vinylmethyldimethoxysilane-tetraethoxysilane oligomer, vinylmethyldiethoxysilane-tetramethoxysilane oligomer, and vinylmethyldiethoxysilane-tetraethoxysilane oligomer; amino group-containing copolymers such as 3-aminopropyl trimethoxysilane-tetramethoxysilane copolymer, 3-aminopropyl trimethoxysilane-tetraethoxysilane copolymer, 3-aminopropyl triethoxysilane-tetramethoxysilane copolymer, 3-aminopropyl methyldimethoxysilane-tetraethoxysilane copolymer, 3-aminopropyl methyldiethoxysilane-tetramethoxysilane copolymer, 3-aminopropyl methyldiethoxysilane-tetraethoxysilane copolymer, and 3-aminopropyl methyldiethoxysilane-tetraethoxysilane copolymer.

The silane compound (D) may be a silane compound represented by the following formula (D1).

(wherein 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 constitutes the-CH of the alkanediyl group and the alicyclic hydrocarbon group ₂ Can be replaced byis-O-or-CO-, R ⁴¹ Represents an alkyl group having 1 to 5 carbon atoms, R ⁴² 、R ⁴³ 、R ⁴⁴ 、R ⁴⁵ R is R ⁴⁶ Each independently represents an alkyl group having 1 to 5 carbon atoms or an alkoxy group having 1 to 5 carbon atoms. )

As A ¹ Examples of the alkanediyl group having 1 to 20 carbon atoms include 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-eicosanediyl group. Examples of the divalent alicyclic hydrocarbon group having 3 to 20 carbon atoms include 1, 3-cyclopentanediyl group and 1, 4-cyclohexanediyl group. as-CH which will constitute the alkanediyl and the alicyclic hydrocarbon group ₂ The group substituted with-O-or-CO-may be-CH ₂ CH ₂ -O-CH ₂ CH ₂ -、-CH ₂ CH ₂ -O-CH ₂ CH ₂ -O-CH ₂ CH ₂ -、-CH ₂ CH ₂ -O-CH ₂ CH ₂ -O-CH ₂ CH ₂ -O-CH ₂ CH ₂ -、-CH ₂ CH ₂ -CO-O-CH ₂ CH ₂ -、-CH ₂ CH ₂ -O-CH ₂ CH ₂ -CO-O-CH ₂ CH ₂ -、-CH ₂ CH ₂ CH ₂ CH ₂ -O-CH ₂ CH ₂ -and-CH ₂ CH ₂ CH ₂ CH ₂ -O-CH ₂ CH ₂ CH ₂ CH ₂ -。

As R ⁴¹ ～R ⁴⁵ Examples of the alkyl group having 1 to 5 carbon atoms include methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl and pentyl groups, and R is ⁴² ～R ⁴⁵ Examples of the alkoxy group having 1 to 5 carbon atoms include methoxy, ethoxy, propoxy, isopropoxy, butoxy, isobutoxy, tert-butoxy and pentyloxy.

Examples of the silane compound represented by the formula (d 1) include bis (tri-C1-5 alkoxysilyl) alkanes 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, and 1, 8-bis (tripropoxysilyl) octane; bis (di C1-5 alkoxyC 1-5 alkylsilyl) C1-10 alkanes such as bis (dimethoxymethylsilyl) methane, 1, 2-bis (dimethoxymethylsilyl) ethane, 1, 2-bis (dimethoxyethylsilyl) ethane, 1, 4-bis (dimethoxymethylsilyl) butane, 1, 4-bis (dimethoxyethylsilyl) butane, 1, 6-bis (dimethoxymethylsilyl) hexane, 1, 6-bis (dimethoxyethylsilyl) hexane, 1, 8-bis (dimethoxymethylsilyl) octane, 1, 8-bis (dimethoxyethylsilyl) octane and the like; bis (mono-C1-5 alkoxy-di-C1-5 alkylsilyl) C1-10 alkane such as 1, 6-bis (methoxydimethylsilyl) hexane, 1, 8-bis (methoxydimethylsilyl) octane, and the like. Among them, bis (tri C1-3 alkoxysilyl) C1-10 alkanes such as 1, 2-bis (trimethoxysilyl) ethane, 1, 3-bis (trimethoxysilyl) propane, 1, 4-bis (trimethoxysilyl) butane, 1, 5-bis (trimethoxysilyl) pentane, 1, 6-bis (trimethoxysilyl) hexane, 1, 8-bis (trimethoxysilyl) octane and the like are preferable, and 1, 6-bis (trimethoxysilyl) hexane and 1, 8-bis (trimethoxysilyl) octane are particularly preferable.

The content of the silane compound (D) is usually 0.01 to 10 parts by mass, preferably 0.03 to 5 parts by mass, more preferably 0.05 to 2 parts by mass, and even more preferably 0.1 to 1 part by mass, based on 100 parts by mass of the resin (a).

The adhesive composition may further contain an antistatic agent.

Examples of the antistatic agent include surfactants, silicone compounds, conductive polymers, ionic compounds, and the like, and ionic compounds are preferable. The ionic compound may be a conventional ionic compound. Examples of the cationic component constituting the ionic compound include organic cations and inorganic cations. Examples of the organic cation include a pyridinium cation, a pyrrolidinium cation, a piperidinium cation, an imidazolium cation, an ammonium cation, a sulfonium cation, and a phosphonium cation. Examples of the inorganic cations include alkali metal cations such as lithium cations, potassium cations, sodium cations, cesium cations, alkaline earth metal cations such as magnesium cations, and calcium cations. In particular, from the viewpoint of compatibility with the (meth) acrylic resin, a pyridinium cation, an imidazolium cation, a pyrrolidinium cation, a lithium cation, and a potassium cation are preferable. The anionic component constituting the ionic compound may be any of an inorganic anion and an organic anion, but from the viewpoint of antistatic performance, an anionic component containing a fluorine atom is preferable. Examples of the anion component containing fluorine atom include hexafluorophosphate anion (PF ₆ ^- ) Bis (trifluoromethanesulfonyl) imide anion [ (CF) ₃ SO ₂ ) ₂ N ^- ]Bis (fluorosulfonyl) imide anion [ (FSO) ₂ ) ₂ N ^- ]Tetrakis (pentafluorophenyl) borate anion [ (C) ₆ F ₅ ) ₄ B ^- ]Etc. These ionic compounds may be used singly or in combination of two or more. Bis (trifluoromethanesulfonyl) imide anions [ (CF) are particularly preferred ₃ SO ₂ ) ₂ N ^- ]Bis (fluorosulfonyl) imide anion [ (FSO) ₂ ) ₂ N ^- ]Tetrakis (pentafluorophenyl) borate anion [ (C) ₆ F ₅ ) ₄ B ^- ]。

From the viewpoint of the stability with time of the antistatic performance of the adhesive layer formed from the adhesive composition, an ionic compound that is solid at room temperature is preferable.

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, based on 100 parts by mass of the resin (a).

The adhesive composition may contain 1 or 2 or more additives such as a solvent, a crosslinking catalyst, a tackifier, a plasticizer, a softener, a pigment, an anticorrosive agent, an inorganic filler, and light scattering fine particles.

< adhesive layer >)

The adhesive layer of the present invention can be formed, for example, by dissolving or dispersing the adhesive composition in a solvent to prepare a solvent-containing adhesive composition, and then applying the solvent-containing adhesive composition to the surface of a substrate and drying the same.

The substrate is preferably a plastic film, and specifically, a release film subjected to a release treatment is exemplified. Examples of the release film include a film obtained by subjecting one surface of a film containing a resin such as polyethylene terephthalate, polybutylene terephthalate, polycarbonate, or polyarylate to a release treatment such as silicone treatment.

The adhesive layer of the present invention is preferably an adhesive layer satisfying the following formula (3), more preferably an adhesive layer also satisfying the formula (4).

A(405)≥0.5 (3)

In the formula (3), A (405) represents absorbance at a wavelength of 405 nm. ]

A(405)/A(440)≥5 (4)

The larger the value of A (405), the higher the absorption at 405 nm. If the value of a (405) is less than 0.5, the absorption at the wavelength of 405nm is low, and deterioration of the organic EL light-emitting element and the liquid crystal phase difference film is liable to occur due to light in the vicinity of 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. The upper limit is not particularly limited, but is usually 10 or less.

The value of A (405)/A (440) represents the magnitude of the absorption at wavelength 405nm relative to the magnitude of the absorption at wavelength 440 nm. The larger the value of A (405)/A (440), the more specific absorption in the wavelength region around 405nm is exhibited, and 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, light around 400nm can be absorbed without impeding color expression of the display device, and photodegradation of the organic EL light-emitting element and the liquid crystal phase difference film can be suppressed. The value of A (405)/A (440) is preferably 10 or more, more preferably 30 or more, and still more preferably 60 or more.

The thickness of the pressure-sensitive adhesive layer of the present invention is usually 0.1 to 100. Mu.m, preferably 3 to 50. Mu.m, more preferably 4 to 25. Mu.m.

< optical laminate >)

The pressure-sensitive adhesive composition of the present invention and the pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition can be used for, for example, bonding optical films.

An optical laminate having an optical film on at least one of the adhesive layers 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 prepare an adhesive composition containing the solvent, and then applying the adhesive composition to the surface of an optical film and drying the adhesive composition. In addition, the pressure-sensitive adhesive layer may be formed on the release film in the same manner, and the pressure-sensitive adhesive layer may be laminated (transferred) to the surface of the optical film.

The optical laminate including the adhesive layer of the present invention will be described with reference to the drawings.

Fig. 1 to 5 show an example of the layer structure of the adhesive layer of the present invention and the optical laminate of the present invention.

The pressure-sensitive adhesive layer 1 shown in fig. 1 is a state in which a release film 2 is bonded to the pressure-sensitive adhesive layer 1 for temporary protection of the pressure-sensitive adhesive layer.

The optical laminate 10A shown in fig. 2 is an optical laminate including an optical film 40, an 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, an adhesive layer 1 according to the present invention, and a release film 2.

The optical laminate 10C shown in fig. 4 and the optical laminate 10D shown in fig. 5 are optical laminates 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, the retardation film 110, an adhesive layer 7a, and a light-emitting element 30 (liquid crystal cell, organic EL cell) according to the present invention.

The optical film 40 is a film having optical functions such as transmitting, reflecting, and absorbing light. The optical film 40 may be a single-layer film or a multilayer 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 condensing film, a window film, and the like, and a polarizing film, a retardation film, a window film, or a laminated film thereof is preferable.

The condensing film is a film used for controlling an optical path or the like, and may be a prism array sheet, a lens array sheet, a sheet with dots attached thereto, or the like.

The brightness enhancement film is a film used for the purpose of improving the brightness of a liquid crystal display device to which a polarizing plate is applied. Specifically, there may be mentioned a reflective polarizing plate designed such that a plurality of films having different refractive indices are laminated to generate anisotropy in reflectance, an alignment film having a cholesteric liquid crystal polymer supported on a base film, a circularly polarizing plate having an alignment liquid crystal layer, and the like.

The window film is a front panel of 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 containing polyimide resin. The window film may be a composite film of an organic material and an inorganic material, such as a resin film containing polyimide and silica. The window film may be provided with a hard coat layer on the surface thereof for imparting functions such as surface hardness, stain resistance, and fingerprint resistance. Examples of the window film include a film described in Japanese patent application laid-open No. 2017-94488.

The polarizing film is a film having a property of absorbing linearly polarized light having a vibration plane parallel to an absorption axis thereof and transmitting linearly polarized light having a vibration plane orthogonal to the absorption axis (parallel to a transmission axis), and for example, a film in which a dichroic dye is adsorbed and oriented by a polyvinyl alcohol resin film can be used.

Examples of the dichroic dye include iodine and a dichroic organic dye.

The saponification degree of the polyvinyl alcohol resin is usually 85 to 100 mol%, preferably 98 mol% or more. The polyvinyl alcohol resin may be modified, for example, an aldehyde-modified polyvinyl formal, polyvinyl acetal, or the like. The polymerization degree of the polyvinyl alcohol resin is usually 1000 to 10000, preferably 1500 to 5000.

In general, a film obtained by forming a film from a polyvinyl alcohol resin is used as a raw material film of a polarizing film. The polyvinyl alcohol resin may be formed into a film by a known method. The thickness of the raw film is usually 1 to 150. Mu.m, and is preferably 10 μm or more in consideration of easiness of stretching and the like.

The polarizing film is produced, for example, by a step of uniaxially stretching a raw film, a step of dyeing the film with a dichroic dye to adsorb the dichroic dye, a step of treating the film with an aqueous boric acid solution, a step of washing the film with water, and finally drying. The thickness of the polarizing film is usually 1 to 30. Mu.m, and from the viewpoint of thinning the optical laminate with the pressure-sensitive adhesive layer, it is preferably 20 μm or less, more preferably 15 μm or less, particularly preferably 10 μm or less.

At least one surface of the polarizing film is preferably a polarizing plate provided with a protective film via an adhesive.

As the adhesive, a known adhesive may be used, and may be an aqueous adhesive or an active energy ray-curable adhesive.

Examples of the aqueous adhesive include conventional aqueous adhesives (for example, adhesives made of an aqueous solution of a polyvinyl alcohol resin, aqueous two-part urethane emulsion adhesives, aldehyde compounds, epoxy compounds, melamine compounds, methylol compounds, isocyanate compounds, amine compounds, and crosslinking agents such as polyvalent metal salts). Among them, an aqueous adhesive formed from an aqueous solution of a polyvinyl alcohol resin can be suitably used. In the case of using the aqueous adhesive, it is preferable that the step of drying the polarizing film and the protective film is performed to remove water contained in the aqueous adhesive after the polarizing film and the protective film are bonded. After the drying step, a curing step of curing at a temperature of about 20 to 45 ℃ may be provided. The adhesive layer formed of an aqueous adhesive is usually 0.001 to 5 μm.

The active energy ray-curable adhesive means an adhesive that cures by irradiation with active energy rays such as ultraviolet rays and electron beams, and examples thereof include a curable composition containing a polymerizable compound and a photopolymerization initiator, a curable composition containing a photoreactive resin, a curable composition containing a binder resin and a photoreactive crosslinking agent, and the like, and ultraviolet-curable adhesives are preferable.

Examples of the method of bonding the polarizing film to the protective film include a method of subjecting at least one of the bonding surfaces to a surface activation treatment such as saponification treatment, corona treatment, and plasma treatment. When the protective films are bonded to both surfaces of the polarizing film, the adhesives used for bonding the resin films may be the same type of adhesive or may be different types of adhesive.

The protective film is preferably a film made of a thermoplastic resin having light transmittance. Specifically, the resin composition includes a polyolefin resin; a cellulose resin; a polyester resin; (meth) acrylic resins; or mixtures, copolymers, etc. When the protective films are provided on both sides of the polarizing film, the protective films may be films containing different thermoplastic resins or films containing the same thermoplastic resin.

When at least one surface of the polarizing film is covered with a protective film, the protective film is preferably a protective film containing a polyolefin resin or a cellulose resin. By using these films, shrinkage of the polarizing film in a high-temperature environment can be effectively suppressed without impairing the optical characteristics of the polarizing film. The protective film may be an oxygen barrier layer.

A preferred configuration of the polarizing plate is one 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 on only one side of the polarizing film, it is more preferable to laminate on the visible side. The protective film laminated on the visible side is preferably a protective film containing a triacetyl cellulose resin or a cycloolefin resin. The protective film may be an unstretched film or may be stretched in an optional direction to have a retardation. A surface treatment layer such as a hard coat layer and 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 surfaces 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 containing a triacetyl cellulose resin, a cycloolefin resin or an acrylic resin. The retardation film may be a zero retardation film described later.

The retardation film is an optical film exhibiting optical anisotropy, and examples thereof include stretched films obtained by stretching a polymer film containing polyvinyl alcohol, polycarbonate, polyester, polyarylate, polyimide, polyolefin, polycycloolefin, polystyrene, polysulfone, polyethersulfone, polyvinylidene fluoride/polymethyl methacrylate, acetylcellulose, ethylene-vinyl acetate copolymer saponified product, polyvinyl chloride, and the like to about 1.01 to 6 times. Among the stretched films, polymer films obtained by uniaxially stretching or biaxially stretching acetylcellulose, polyester, polycarbonate films, or cycloolefin resin films are preferable. The retardation film may be a retardation film which exhibits optical anisotropy by applying a liquid crystalline compound to a substrate and aligning the compound.

In the present specification, the retardation film includes a zero retardation film, and also includes films called a uniaxial retardation film, a low photoelastic modulus retardation film, a large viewing angle retardation film, and the like.

The zero-retardation film refers to the front retardation R _e Retardation R in thickness direction _th All of them are optically isotropic films of-15 to 15 nm. Examples of the zero-retardation film include cellulose-based resins, polyolefin-based resins (chain polyolefin-based resins, polycycloolefin-based resins, etc.), and polyparaphenylene-based resinsThe resin film of the ethylene glycol diformate resin is preferably a cellulose resin or a polyolefin resin in view of easy control of the retardation value and easy acquisition. The zero-delay film can also be used as a protective film. Examples of the zero retardation film include "Z-TAC" (trade name) sold by Fuji film (Inc.), "Zerotac (registered trademark)" sold by Konica Minolta Opto (Inc.), and "ZF-14" (trade name) sold by ZEON (Inc.) of Japan.

In the optical film of the present invention, the retardation film is preferably one exhibiting optical anisotropy by applying a liquid crystalline compound and aligning the film.

As a film exhibiting optical anisotropy by application and alignment of a liquid crystalline compound, the following first to fifth modes can be given.

A first mode: phase difference film in which rod-like liquid crystal compound is oriented in horizontal direction with respect to supporting substrate

The second mode is as follows: phase difference film in which rod-like liquid crystal compound is oriented in vertical direction with respect to supporting substrate

Third mode: retardation film in which rod-like liquid crystal compound changes orientation in spiral manner in plane

Fourth formula: phase difference film in which discotic liquid crystal compound is obliquely oriented

Fifth mode: biaxial retardation film in which discotic liquid crystal compound is oriented in vertical direction with respect to support substrate

For example, the first, second, and fifth modes can be suitably used as an optical film used in an organic electroluminescent display. Alternatively, these retardation films may be laminated and used.

When the retardation film is a layer containing a polymer in an oriented state of a polymerizable liquid crystal compound (hereinafter, sometimes referred to as an "optically anisotropic layer"), the retardation film preferably has inverse wavelength dispersibility. The reverse wavelength dispersibility is an optical characteristic in which the in-plane retardation value of the liquid crystal at a short wavelength is smaller than the in-plane retardation value of the liquid crystal at a long wavelength, and the retardation film preferably satisfies the following formulas (7) and (8). Re (λ) represents an in-plane phase difference value with respect to light having a wavelength of λnm.

Re(450)/Re(550)≤1 (7)

1≤Re(630)/Re(550) (8)

In the optical film of the present invention, in the case where the retardation film is of the first mode and has inverse wavelength dispersibility, since the coloration at the time of black display in the display device is reduced, it is preferable that 0.82.ltoreq.Re (450)/Re (550). Ltoreq.0.93 in the above formula (7). Furthermore, re (550) is preferably 120.ltoreq.Re (150).

Examples of the polymerizable liquid crystal compound in the case where the retardation film is a film having an optically anisotropic layer include compounds having a polymerizable group among compounds described in "3.8.6 network (fully crosslinked)", "6.5.1 liquid crystal material b..polymerizable nematic liquid crystal material" which are compiled by the liquid crystal review and edit committee, and issued by the Ministry of the liquid crystal review and edit (12 th year, 10 month, 30 th year), and polymerizable liquid crystal compounds described in japanese patent application publication nos. 2010-31223, 2010-270108, 2011-6360, 2011-207765, 2011-162678, 2016-81035, 2017/043438 and 2011-207765.

As a method for producing a retardation film from a polymer in an aligned state of a polymerizable liquid crystal compound, for example, a method described in japanese patent application laid-open No. 2010-31223 and the like are cited.

In the case of the second embodiment, the front phase difference Re (550) is adjusted to a range of 0 to 10nm, preferably 0 to 5nm, and the phase difference R in the thickness direction is only required _th The wavelength is adjusted to a range of-10 to-300 nm, preferably-20 to-200 nm. For a thickness direction phase difference value R representing refractive index anisotropy in the thickness direction _th The phase difference value R can be measured according to 50 degrees of inclination by taking the fast axis in the plane as the inclination axis ₅₀ Sum-in-plane phase difference value R ₀ And (5) calculating. Namely, the phase difference value R in the thickness direction _th Can be based on the in-plane phase difference value R ₀ Phase difference value R measured by tilting 50 degrees with fast axis as tilting axis ₅₀ Thickness d of the retardation film, and average refractive index n of the retardation film ₀ N is obtained by the following formulas (10) to (12) _x 、n _y N is as follows _z They are calculated by substituting them into expression (9).

R _th ＝[(n _x +n _y )/2-n _z ]×d (9)

R ₀ ＝(n _x -n _y )×d (10)

R ₅₀ ＝(n _x -n _y ')×d/cos(φ) (11)

(n _x +n _y +n _z )/3＝n ₀ (12)

Here the number of the elements is the number,

φ＝sin ^-1 〔sin(40°)/n ₀ 〕

n _y '＝n _y ×n _z /〔n _y ² ×sin ² (φ)+n _z ² ×cos ² (φ)〕 ^1/2

examples of the FILM exhibiting optical anisotropy by application and alignment of the liquid crystalline compound and the FILM exhibiting optical anisotropy by application of the inorganic lamellar compound include a FILM called a temperature-compensated retardation FILM, "NH FILM" (trade name; a FILM in which rod-like liquid crystal is obliquely oriented) sold by JX solar energy source (ltd.), "WV FILM" (trade name; a FILM in which disc-like liquid crystal is obliquely oriented) sold by fuji FILM (ltd.), "VAC FILM" (trade name; a FILM in which disc-like liquid crystal is completely biaxially oriented) sold by resident chemical (ltd.), and "newVAC FILM" trade name "sold by resident chemical (ltd.); biaxially oriented film), and the like.

The retardation film may be a multilayer film having two or more layers. For example, a retardation film in which a protective film is laminated on one or both surfaces of a retardation film, and a retardation film in which two or more retardation films are laminated via an adhesive or an adhesive can be cited.

In the case where the retardation film is a multilayer film, as shown in fig. 4, as a configuration of an optical laminate including the optical film of the present invention, there is a configuration including a retardation film 110 in which a 1/4 wavelength retardation layer 50 that imparts a retardation of 1/4 wavelength to transmitted light and a 1/2 wavelength retardation layer 70 that imparts a retardation of 1/2 wavelength to transmitted light are laminated via an adhesive layer or an adhesive layer 60. As shown in fig. 5, the optical film 40 is also provided by laminating the 1/4 wavelength difference layer 50a and the positive C layer 80 via the adhesive layer or the pressure-sensitive adhesive layer 60.

The 1/4 wavelength retardation layer 50 imparting a retardation of 1/4 wavelength and the 1/2 wavelength retardation layer 70 imparting a retardation of 1/2 wavelength to transmitted light in fig. 4 may be the optical film of the first embodiment or the optical film of the fifth embodiment. In the case of the configuration of fig. 4, at least one of them is more preferably the fifth aspect.

In the case of the configuration of fig. 5, the 1/4 wavelength retardation layer 50a is preferably an optical film according to the first embodiment, and more preferably satisfies the formulas (7) and (8).

The adhesive layer 7a in fig. 4 and 5 is a layer formed of an adhesive composition. The adhesive layer 7a may be formed of a known adhesive composition or an adhesive composition of the present invention.

< liquid Crystal display device >)

The resin, the adhesive composition containing the resin, and the optical laminate containing the adhesive layer formed from the adhesive composition of the present invention can be used in display devices (FPD: flat panel display) such as organic EL devices, liquid crystal cells, and the like, by being laminated on the display devices such as organic EL devices and liquid crystal cells.

Examples

The present invention will be described in further detail with reference to examples and comparative examples. In examples, comparative examples and polymerization examples, "%" and "parts" are "% by mass" and "parts by mass" unless otherwise specified.

Example 1: synthesis of light selective absorbing compounds having indole structure and polymerizable group

After replacing a 1000mL four-necked flask equipped with a Dimrot condenser and a thermometer with a nitrogen atmosphere, 100 parts of a compound (1-methyl-2-phenyl-1H-indole-3-carbaldehyde) represented by the formula (1), 40 parts of cyanoacetic acid, 76 parts of piperidine and 300 parts of acetonitrile were added, and the mixture was stirred and then incubated at 80℃for 4 hours. Crystals precipitated from the resulting mixture were separated by filtration and taken out. The resulting crystals were mixed with 500 parts of 5% sulfuric acid and incubated at 80℃for 1 hour while stirring. The resulting mixture was filtered to give a solid. The obtained solid was washed with 300 parts of water and dried to obtain 116 parts of a compound (2-cyano-3- (1-methyl-2-phenyl-1H-indol-3-yl) -2-acrylic acid) represented by formula (2).

Identification of Compounds represented by formula (2)

¹ H-NMR(CDCl ₃ )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)

After replacing a 100mL four-necked flask equipped with a thermometer with a nitrogen atmosphere, 5 parts of a compound represented by the 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 chloroform were added, and the mixture was cooled to 0 ℃. To the resulting mixture, 2.2 parts of N, N' -diisopropylcarbodiimide was added dropwise while maintaining the temperature at 0 to 5 ℃. After the dropwise addition, the resulting mixture was incubated at 10℃for 4 hours. The resulting mixture was filtered to obtain a filtrate. The resulting filtrate was concentrated to give an oil. 50 parts of toluene and 50 parts of water were mixed with the obtained oil and separated to obtain a toluene layer. The toluene layer was concentrated to give yellow crude crystals. The crude crystal was recrystallized from isopropyl alcohol to give 4.9 parts of a compound (2-cyano-3- (1-methyl-2-phenyl-1H-indol-3-yl) -2-acrylic acid-4-acryloyloxybutyl ester) represented by formula (3). The maximum absorption wavelength of the compound represented by the formula (3) was 386nm.

Identification of Compounds represented by formula (3)

¹ H-NMR(CDCl ₃ )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)

The resulting methyl ethyl ketone solution (0.006 g/L) of the compound represented by formula (3) was placed in a 1cm quartz cell, and the quartz cell was set in a spectrophotometer UV-2450 (manufactured by Shimadzu corporation) to measure absorbance in a wavelength range of 300 to 800nm in 1nm step by a double beam method. The gram absorption coefficient of each wavelength was calculated from the value of the obtained absorbance, the concentration of the compound in the solution, and the optical path length of the quartz cell. As a result, ε (405) =34.9L/(g·cm), ε (440) =2.0L/(g·cm), ε (405)/ε (440) =17.5.

ε(λ)＝A(λ)/CL

[ in the formula, ε (λ) represents the gram absorbance coefficient L/(g.cm) of the compound represented by formula (3) at wavelength λnm, A (λ) represents the absorbance at wavelength λnm, C represents the concentration g/L, and L represents the optical path length cm of the quartz cell. A kind of electronic device

Example 2: synthesis of light selective absorbing compounds having indole structure and polymerizable group

4.3 parts of a compound (2-cyano-3- (1-methyl-2-phenyl-1H-indol-3-yl) -2-acrylic acid-2-acryloyloxyethyl ester) represented by formula (4) was obtained in the same manner as in example 1 except that 2 parts of 2-hydroxyethyl acrylate was used in place of 2.3 parts of 4-hydroxybutyl acrylate. The maximum absorption wavelength of the compound represented by the formula (4) was 388nm. As a result of obtaining the gram absorbance coefficient in the same manner as in example 1, ε (405) =45.4L/(g·cm), ε (440) =1.0L/(g·cm), ε (405)/ε (440) =45.4.

Identification of Compounds represented by formula (4)

¹ H-NMR(CDCl ₃ )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)

Example 3: synthesis of resin (A-1) containing structural unit having indole Structure

To a reaction vessel equipped with a condenser, a nitrogen inlet, a thermometer and a stirrer, a mixed solution of 141 parts of ethyl acetate, 94 parts of butyl acrylate, 3 parts of 2-hydroxyethyl acrylate and 3 parts of a compound represented by formula (3) was added as a solvent, and the air in the apparatus was replaced with nitrogen gas to be free of oxygen, and the internal temperature was set to 60 ℃. To the resultant mixture, the entire amount of a solution obtained by dissolving 0.63 part of azobisisobutyronitrile (polymerization initiator) in 10 parts of ethyl acetate was added. The resultant mixture was kept at 60℃for 7 hours, and then the entire amount of a solution obtained by dissolving 0.0012 parts of 4-methoxyphenol (polymerization inhibitor) in 5 parts of ethyl acetate was added to the resultant mixture. To the resulting mixture, ethyl acetate was added and the concentration of the resin (A-1) having an indole structure was adjusted to 20%, to prepare an ethyl acetate solution of the resin (A-1) having an indole structure. The weight average molecular weight Mw of the obtained indole-structured resin (A-1) was 74 tens of thousands in terms of polystyrene based on GPC, and Mw/Mn was 5.2. The glass transition temperature based on DSC was-51 ℃.

< gram absorbance measurement ∈ -

The methyl ethyl ketone solution (0.011 g/L) of the obtained resin (A-1) was charged into a 1cm quartz cell, the quartz cell was set in a spectrophotometer UV-2450 (manufactured by Shimadzu corporation), and absorbance was measured in a wavelength range of 300 to 800nm in 1nm step by a double beam method. The gram absorbance coefficient for each wavelength was calculated from the value of the absorbance obtained, the concentration of the resin (a) in the solution, and the optical path length of the quartz cell. As a result, epsilon (405) =0.442L/(g·cm), epsilon (440) =0.008L/(g·cm), epsilon (405)/epsilon (440) =53.3 of the resin (a-1).

ε(λ)＝A(λ)/CL

[ in the formula, [ epsilon ] (lambda) represents the gram absorbance coefficient L/(g cm) of the resin (A) at the wavelength of lambda nm, A (lambda) represents the absorbance at the wavelength of lambda nm, C represents the concentration g/L, and L represents the optical path length cm of the quartz cell. A kind of electronic device

Example 4: synthesis of resin (A-2) containing structural unit having indole Structure

To a reaction vessel equipped with a condenser, a nitrogen inlet, a thermometer and a stirrer, a mixed solution of 141 parts of ethyl acetate, 94 parts of butyl acrylate, 3 parts of 2-hydroxyethyl acrylate and 3 parts of a compound represented by formula (4) was added as a solvent, and the air in the apparatus was replaced with nitrogen gas to be free of oxygen, and the internal temperature was set to 60 ℃. To the resultant mixture, the entire amount of a solution obtained by dissolving 0.63 part of azobisisobutyronitrile (polymerization initiator) in 10 parts of ethyl acetate was added. The resultant mixture was kept at 60℃for 7 hours, and then the entire amount of a solution obtained by dissolving 0.0012 parts of 4-methoxyphenol (polymerization inhibitor) in 5 parts of ethyl acetate was added to the resultant mixture. To the resulting mixture, ethyl acetate was added and the concentration of the resin (A-2) having an indole structure was adjusted to 20% to prepare an ethyl acetate solution of the resin (A-2) having an indole structure. The weight average molecular weight Mw of the obtained indole-structured resin (A-2) was 67 million in terms of polystyrene based on GPC, and Mw/Mn was 4.9. The glass transition temperature based on DSC was-50 ℃. Further, as a result of measuring the gram absorbance coefficient of the resin (a-2) in the same manner as in example 3, epsilon (405) =0.336L/(g·cm), epsilon (440) =0.035L/(g·cm), and epsilon (405)/epsilon (440) =9.5.

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 added, and the internal temperature was set to 60℃while the air in the apparatus was replaced with nitrogen gas to be free of oxygen. To the resultant mixture, the entire amount of a solution obtained by dissolving 0.63 part of azobisisobutyronitrile (polymerization initiator) in 10 parts of ethyl acetate was added. The resultant mixture was kept at 60℃for 7 hours, and then the entire amount of a solution obtained by dissolving 0.0012 parts of 4-methoxyphenol (polymerization inhibitor) in 5 parts of ethyl acetate was added to the resultant mixture. To the resulting mixture, ethyl acetate was added and the concentration of the acrylic resin (A-3) was adjusted so as to be 20%, to prepare an ethyl acetate solution of the acrylic resin (A-3). The weight average molecular weight Mw of the obtained acrylic resin (A-3) in terms of polystyrene based on GPC was 60 tens of thousands, and Mw/Mn was 6.0. The glass transition temperature based on DSC was-49 ℃. Further, as a result of measuring gram absorbance coefficients by the same method as in example 3, no absorbance at 405nm and no absorbance at 440nm were observed, and as a result, the absorbance was 0.

Adhesive composition and production of adhesive layer

(a) Preparation of adhesive composition

Example 5: preparation of adhesive composition (1)

To the ethyl acetate solution (resin concentration: 20%) of the obtained indole-structured resin (A-1), 0.5 part of a crosslinking agent (CORONATE L, solid content 75% manufactured by TOSOH) and 0.5 part of a silane compound (KBM-403 manufactured by Xinyue chemical Co., ltd.) were mixed with respect to 100 parts of the solid content of the solution, and 2-butanone was added so that the solid content concentration was 14%, thereby obtaining an adhesive composition (1). The amount of the crosslinking agent (coronete L) is the mass fraction of the active ingredient.

Example 6: preparation of adhesive composition (2)

To the ethyl acetate solution (resin concentration: 20%) of the obtained indole-structured resin (A-2), 0.5 part of a crosslinking agent (CORONATE L, solid content 75% manufactured by TOSOH) and 0.5 part of a silane compound (KBM-403 manufactured by Xinyue chemical Co., ltd.) were mixed with respect to 100 parts of the solid content of the solution, and 2-butanone was added so that the solid content concentration was 14%, thereby obtaining an adhesive composition (2). The amount of the crosslinking agent (coronete L) is the mass fraction of the active ingredient.

Comparative example 1: preparation of adhesive composition (3)

To an ethyl acetate solution (resin concentration: 20%) of the acrylic resin (A-3), 0.5 parts of a crosslinking agent (CORONATE L, 75% of solid matter: manufactured by TOSOH) and 0.5 parts of a silane compound (KBM-403 manufactured by Xinyue chemical industry Co., ltd.) and 3 parts of a light absorbing compound (ultraviolet absorber; BONASORB UA-3911 manufactured by ORIENT chemical industry Co., ltd.) were mixed with respect to 100 parts of the solid matter of the solution, and 2-butanone was added so that the solid matter concentration was 14%, to obtain an adhesive composition (3). The amount of the crosslinking agent (coronete L) is the mass fraction of the active ingredient.

[ production example 1]: preparation of adhesive composition (4)

To an ethyl acetate solution (resin concentration: 20%) of the acrylic resin (A-3), 0.5 part of a crosslinking agent (CORONATE L, 75% of solid matter: manufactured by TOSOH) and 0.5 part of a silane compound (KBM-403 manufactured by Xinyue chemical industry Co., ltd.) were mixed with respect to 100 parts of the solid matter of the solution, and 2-butanone was added so that the solid matter concentration was 14%, to obtain an adhesive composition (4).

(b) Preparation of adhesive layer

The adhesive compositions prepared in (a) were applied to the release treated surface of a release treated polyethylene terephthalate film (SP-PLR 382050, hereinafter simply referred to as "separator" from LINTEC corporation) by using an applicator, and dried at 100 ℃ for 1 minute to prepare an adhesive layer. The thickness of the resulting adhesive layer was 15. Mu.m.

The adhesive layer formed from the adhesive composition obtained in example 5 was set as the adhesive layer (1), the adhesive layer formed from the adhesive composition obtained in example 6 was set as the adhesive layer (2), the adhesive layer formed from the adhesive composition obtained in comparative example 1 was set as the adhesive layer (3), and the adhesive layer formed from the adhesive composition obtained in production example 1 was set as the adhesive layer (4).

< absorbance measurement of adhesive layer >)

The obtained pressure-sensitive adhesive layer (1) was bonded to alkali-free glass (trade name "EAGLE XG" manufactured by CORNING corporation), and after peeling the separator, a cycloolefin resin film (ZF-14 manufactured by ZEON corporation) was bonded to the pressure-sensitive adhesive layer (1) to prepare a laminate for pressure-sensitive adhesive layer evaluation. The produced laminate for evaluating an adhesive layer was set in a spectrophotometer UV-2450 (manufactured by Shimadzu corporation) and absorbance was measured in a wavelength range of 300 to 800nm in 1nm step by a two-beam method. The absorbance at 405nm and 440nm of each of the alkali-free glass monomer and the cycloolefin resin film monomer was 0.

The absorbance of the adhesive layer (2) and the adhesive layer (3) were also measured in the same manner. The absorbance of the adhesive layers (1) to (3) is shown in table 1.

TABLE 1

< fabrication of optical laminate >

(i) Polarizing film production

A polyvinyl alcohol film having an average polymerization degree of about 2400 and a saponification degree of 99.9 mol% and a thickness of 30 μm ("Kuraray Poval Film VF-PE#3000", (manufactured by Kuraray) was immersed in pure water at 37℃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 ℃. Thereafter, the mixture 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 ℃. Then, the film was washed with pure water at 10℃and dried at 85℃to obtain a polarizing film A having a thickness of about 12. Mu.m, in which iodine was adsorbed to polyvinyl alcohol and oriented. Stretching is mainly performed in the steps of iodine dyeing and boric acid treatment, and the total stretching ratio is 5.3 times.

(ii) Manufacture of polarizing plate

An optical film a (polarizing plate, thickness 67 μm) was produced by bonding a transparent protective film ("25 KCHCN-TC", manufactured by letterpress printing) obtained by applying a 7 μm hard coat layer to a triacetylcellulose film having a thickness of 25 μm to one surface of the polarizing film obtained in (i) via an adhesive formed from an aqueous solution of a polyvinyl alcohol resin, and bonding a cycloolefin resin film having a thickness of 23 μm (ZF 14-023 manufactured by ZEON corporation) to the surface opposite to the transparent protective film.

(iii) Preparation of composition for Forming photo-alignment film

A compound having the following structure was synthesized by the method described in JP-A2013-33248. 5 parts of the following compound was mixed with 95 parts of cyclopentanone as a component, and the resultant mixture was stirred at 80 ℃ for 1 hour, thereby obtaining a composition for forming a photo-alignment film.

(iv) Preparation of compositions comprising polymerizable liquid Crystal Compounds

The polymerizable liquid crystal compound A having the following structure was synthesized by the method described in JP-A2010-31223. The maximum absorption wavelength λmax (LC) of the polymerizable liquid crystal compound A was 350nm.

12 parts of a polymerizable liquid crystal compound A having the following structure, 0.12 part of a polyacrylate compound (leveling agent; BYK-361N, manufactured by BYK-Chemie Co., ltd.), 0.72 part of a polymerization initiator (Irgacure 369, manufactured by Ciba Specialty Chemicals Co., ltd.), and 100 parts of cyclopentanone were mixed to obtain a composition containing the polymerizable liquid crystal compound.

(v) Manufacture of optically anisotropic layers

The cycloolefin resin film (ZF-14 manufactured by ZEON Co., ltd.) was treated 1 time with a corona treatment device (AGF-B10, manufactured by spring motor Co., ltd.) under conditions of an output of 0.3kW and a treatment rate of 3 m/min. The composition for forming a photo-alignment film obtained in (iii) was applied to the corona-treated surface by a bar coater, dried at 80℃for 1 minute, and irradiated with polarized UV light (SPOTCURE SP-7; manufactured by USHIO Motor Co., ltd.) at 100mJ/cm ² To perform polarized UV exposure. The film thickness of the obtained alignment film was measured by ellipsometry, and the result was 100nm.

Next, a coating liquid containing the composition A containing the polymerizable liquid crystal compound obtained in (iv) is applied onto the alignment film using a bar coater, and thenAfter drying at 120℃for 1 minute, ultraviolet rays (cumulative light amount at wavelength 313nm under nitrogen atmosphere: 500 mJ/cm) were irradiated from the side coated with the composition containing the polymerizable liquid crystal compound using a high-pressure mercury lamp (UNICURE VB-15201BY-A, USHIO, manufactured BY Motor Co., ltd.) ² ) Thereby forming an optical film including the optically anisotropic layer 1. The film thickness of the optically anisotropic layer 1 thus obtained was measured by a laser microscope, and found to be 2. Mu.m.

Example 7: production of optical laminate (1)

The separator is peeled off by bonding the pressure-sensitive adhesive layer (1) to the cycloolefin resin film surface of the polarizing plate produced in the above (ii). Then, the separator-peeled surface of the pressure-sensitive adhesive layer (1) is bonded to the surface of the optically anisotropic layer produced in (v) opposite to the surface of the cycloolefin resin film, and the cycloolefin resin film is peeled off. An adhesive layer (4) with a separator is bonded to the surface of the optically anisotropic layer from which the cycloolefin resin film has been peeled off, and an optical laminate (1) is obtained.

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).

Comparative example 2: production of an 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).

[ production example 2]: production of an 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).

< evaluation of bleeding resistance of adhesive layer >

The obtained optical laminate (1) was cut to a size of 40mm by 40mm, and the separator laminated on the adhesive layer (4) was peeled off and bonded to alkali-free glass [ trade name "EAGLE XG" manufactured by CORNING corporation. The deposition of crystals of the compound in the plane was confirmed by a microscope on the obtained optical laminate with glass. Thereafter, the obtained optical laminate with glass was put into an oven at a temperature of 23℃for 500 hours, and the deposition of crystals of the compound in the plane was confirmed using a microscope, and the presence or absence of an increase in the deposition of crystals of the compound was confirmed. The evaluation results are shown in table 2.

The adhesive layer was evaluated for bleeding resistance in the same manner as described above, except that the optical laminate (1) was replaced with the optical laminate (2). The evaluation results are shown in table 2.

The adhesive layer was evaluated for bleeding resistance in the same manner as described above, except that the optical laminate (1) was replaced with the optical laminate (3). The evaluation results are shown in table 2.

< confirmation of the influence of the adhesive layer on the phase-difference variation of the optically anisotropic layer)

The obtained optical laminate (1) was cut to a size of 40mm by 40mm, and the separator laminated on the adhesive layer (4) was peeled off and bonded to alkali-free glass [ trade name "EAGLE XG" manufactured by CORNING corporation. The phase difference value of the obtained glass-equipped optical laminate at a wavelength of 450nm was measured by a birefringence measuring apparatus (KOBA-WR; manufactured by prince measuring instruments Co., ltd.). Thereafter, the optical laminate with glass was put into an oven at a temperature of 80℃for 120 hours, taken out, left in a 50% environment at 23℃for 24 hours, and then the phase difference value at a wavelength of 450nm was measured again.

The optical laminate (1) was replaced with the optical laminate (4) in the same manner as described above, and then the measurement was performed.

The change in the phase difference between the optical layered body (1) and the optical layered body (4) was obtained by subtracting the change in the phase difference between the optical layered body (4) and the optical layered body (1) before and after the durability and the change in the phase difference between the optical layered body and the optical layered body (1) and the optical layered body. The phase difference change values are shown in table 2.

The effect of the change in the retardation of the optically anisotropic layer due to the adhesive layer was confirmed in the same manner as described above, except that the optical laminate (1) was replaced with the optical laminate (2). Table 2 shows the phase difference change values before and after the durability.

The effect of the change in the retardation of the optically anisotropic layer due to the adhesive layer was confirmed in the same manner as described above, except that the optical laminate (1) was replaced with the optical laminate (3). Table 2 shows the phase difference change values before and after the durability.

< absorbance measurement of optical film >)

The obtained optical laminate (1) was cut to a size of 40mm by 40mm, and the separator laminated on the adhesive layer (4) was peeled off and bonded to alkali-free glass [ trade name "EAGLE XG" manufactured by CORNING corporation. The obtained measurement sample was subjected to measurement of transmission spectra in the transmission axis direction and the absorption axis direction of the optical layered body (1) in the wavelength range of 380 to 780nm using a spectrophotometer (product name "V7100" manufactured by Japan Spectrophotometer, inc.), and absorbance at 405nm of the optical layered body (1) was calculated from the transmission spectra in the transmission axis direction of the optical layered body (1). The absorbance of each of the TAC film monomer, the COP film monomer and the alkali-free glass monomer was 0 at 350nm, 405nm and 440 nm.

< evaluation of weather resistance >

The optical laminate (1) was put into a solar weather-proof test box (SuNSHINE WEATHER METER S, model number, manufactured by Suga testing Co., ltd.) at a temperature of 63℃and a humidity of 50% for 24 hours, and subjected to a weather resistance test for 24 hours. The absorbance of the sample taken out was measured by the same method as the absorbance measurement of the optical film. Based on the absorbance thus measured, the absorbance retention of the sample at 405nm was determined based on the following equation. The results are shown in Table 1. The higher the absorbance retention, the less the light selective absorption function is deteriorated, and the good weather resistance is exhibited.

Absorbance retention = (a (405) after the endurance test)/a (405) before the endurance test) ×100

TABLE 2

When an adhesive layer formed of an adhesive composition containing the resin (a) of the present invention is laminated on an optical film, the change in phase difference is suppressed. This is considered to be because, by adding the light selective absorbing compound having a polymerizable group and an indole structure to the resin, the transfer of the light selective absorbing compound having an indole structure can be suppressed as compared with the adhesive composition containing the light selective absorbing compound having an indole structure alone.

In addition, the adhesive layer formed from the adhesive composition containing the resin (a) of the present invention has good bleeding resistance without increasing precipitation of the compound even after being used in a heat resistance test at 85 ℃ for 120 hours. Further, the value of a (405)/a (440) of the adhesive layer formed from the adhesive composition containing the resin (a) of the present invention is good.

Industrial applicability

The resin of the present invention, the adhesive composition containing the resin, the adhesive layer formed from the adhesive composition, and the optical laminate containing the adhesive layer can be suitably used in liquid crystal panels and liquid crystal display devices.

Description of the reference numerals

1 adhesive layer, 2 release film, 10A, 10B, 10C, 10D optical laminate, 8 protective film, 7 adhesive layer, 7a adhesive layer, 9 polarizing film, 30 light emitting element, 40 optical film, 50A 1/4 wavelength retardation layer, 60 adhesive layer or adhesive layer, 70 1/2 wavelength retardation layer, 80 positive C layer, 100 polarizing plate, 110 retardation film.

Claims

1. An adhesive composition comprising a resin A containing a structural unit having an indole structure and at least 1 structural unit selected from the structural units described in the following group A,

The content of at least 1 structural unit selected from the structural units described in the group A is 50% by mass or more with respect to the total structural units of the resin A,

the content of the resin A is 60 to 99.99 mass% based on 100 mass% of the solid content of the adhesive composition,

Wherein R is ^a1 A hydrocarbon group of 2 valences;

R ^b1 r is R ^b2 Each independently represents a hydrogen atom or a hydrocarbon group;

R ^c1 r is R ^c2 Each independently represents a hydrocarbyl group of valence 2.

2. The adhesive composition of claim 1, wherein,

the glass transition temperature of the resin A is below 40 ℃.

3. The adhesive composition according to claim 1 or 2, wherein,

resin a is a resin satisfying the following formula (1):

ε(405)≥0.02 (1)

in the formula (1), epsilon (405) represents the gram absorption coefficient of the resin A at the wavelength of 405 nm; the gram absorbance is in units of L/(g.cm).

4. The adhesive composition according to claim 1 or 2, wherein,

Resin a is a resin satisfying the following formula (2):

ε(405)/ε(440)≥5 (2)

in the formula (2), ε (405) represents the gram absorbance coefficient of the resin A at the wavelength of 405nm, ε (440) represents the gram absorbance coefficient of the resin A at the wavelength of 440 nm.

5. The adhesive composition according to claim 1 or 2, wherein,

the resin a is a resin containing a structural unit having an indole structure in a side chain.

6. The adhesive composition according to claim 5, wherein,

the structural unit having an indole structure in the side chain is a structural unit derived from a light selective absorbing compound having a polymerizable group and an indole structure.

7. The adhesive composition of claim 6, wherein,

the light selective absorbing compound having a polymerizable group and an indole structure is a compound satisfying the following formula (1-a):

ε(405)≥5(1-a)

in the formula (1-a), epsilon (405) represents the gram absorption coefficient of a compound having a polymerizable group and an indole structure at a wavelength of 405 nm; the gram absorbance is in units of L/(g.cm).

8. The adhesive composition of claim 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 the formula (2-a), ε (405) represents the gram absorbance coefficient of a compound having a polymerizable group and an indole structure at a wavelength of 405nm, and ε (440) represents the gram absorbance coefficient of a compound having a polymerizable group and an indole structure at a wavelength of 440 nm.

9. The adhesive composition according to claim 5, wherein,

the structural unit having an indole structure in the side chain is a structural unit derived from a compound represented by formula (I) or a structural unit derived from a compound represented by formula (II):

in the formula (I), R ¹ 、R ² 、R ³ 、R ⁴ 、R ⁵ R is R ⁶ Each independently represents a hydrogen atom, a heterocyclic group, a halogen atom, a nitro group, a cyano group, a hydroxyl group, a carboxyl group,An aliphatic hydrocarbon group having 1 to 25 carbon atoms which may be substituted, or an aromatic hydrocarbon group having 6 to 18 carbon atoms which may be substituted, wherein the aliphatic hydrocarbon group or the aromatic hydrocarbon group contains-CH ₂ -optionally replaced by-NR ^1A -、-SO ₂ -, -CO-, -O-; -S-or-CF ₂ -；

R ^1A An aromatic hydrocarbon group having 6 to 18 carbon atoms, which represents a hydrogen atom, an alkyl group having 1 to 25 carbon atoms, or a compound thereof;

E ¹ represents an electron withdrawing group;

z represents a linking group;

a represents a polymerizable group;

in the formula (II), R ¹² R is R ¹⁷ Each independently represents a hydrogen atom, a heterocyclic group, a halogen atom, a nitro group, a cyano group, a hydroxyl group, a carboxyl 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, wherein the aliphatic hydrocarbon group or the aromatic hydrocarbon group contains-CH ₂ -optionally replaced by-NR ^11A -、-SO ₂ -, -CO-, -O-; -S-or-CF ₂ -；

R ¹¹ 、R ¹³ 、R ¹⁴ 、R ¹⁵ R is R ¹⁶ Each independently represents a hydrogen atom, a heterocyclic group, a halogen atom, a nitro group, a cyano group, a hydroxyl group, a carboxyl group, a group containing a polymerizable group, an aliphatic hydrocarbon group having 1 to 25 carbon atoms which may be substituted, or an aromatic hydrocarbon group having 6 to 18 carbon atoms which may be substituted, the aliphatic hydrocarbon group or the aromatic hydrocarbon group containing-CH ₂ -optionally replaced by-NR ^12A -、-SO ₂ -, -CO-, -O-; -S-or-CF ₂ -；

Wherein R is ¹¹ 、R ¹³ 、R ¹⁴ 、R ¹⁵ R is R ¹⁶ Represents a group containing a polymerizable group;

R ^11A r is R ^12A Each independently 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 ¹¹ represents an electron-withdrawing group and is represented by,

the group containing a polymerizable group is a group represented by the formula (I-2),

*-R ¹¹⁵ -X ² (I-2)

in the formula (I-2), X ² Represents a polymerizable group and is represented by a polymerizable group,

R ¹¹⁵ represents an alkanediyl group having 1 to 12 carbon atoms, which alkanediyl group contains-CH ₂ -optionally replaced by-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.

10. The adhesive composition of claim 9, wherein,

R ² is phenyl.

11. The adhesive composition of claim 9, wherein,

The compound shown in the formula (I) is a compound shown in the formula (III):

R ¹ 、R ³ 、R ⁴ 、R ⁵ 、R ⁶ e and E ¹ Meaning the same as above;

R ⁷ represents a hydrogen atom, cyano, methyl or phenyl;

Z ¹ represents an alkanediyl group having 1 to 12 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms and having 2 valencies, -O-R ^2A -＊1、-S-R ^2B A method for producing a composite material 'Qingzhi' for treating coronary heart disease 1 or-NR ^1D -R ^2C -＊1；

Z ² Represents a single bond, O2-CO-O-, O2-O-CO-, O2-S (=O) ₂ -、＊2-O-SO ₂ -、

＊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-CO-S-, -2-S-CO-, or a perfluoroalkyldi-alkyl group having 1 to 4 carbon atoms;

R ^1B 、R ^1C 、R ^1D 、R ^1E r is 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 r is R ^2F Each independently represents a hydrocarbon group having 1 to 18 carbon atoms and having a valence of 2;

a1 represents and Z ² Is a bonding end of (a);

2 represents Z ¹ Is a bonding end of the (c).

12. The adhesive composition of claim 9, wherein the polymerizable group is an ethynyl group, an epoxy group, an oxetanyl group, a vinyl ether group, an acrylonitrile group, a methacrylonitrile group, a vinyl group, an a-methyl vinyl group, an acryl group, a methacryl group, an allyl group, a styryl group, an acrylamide group, or a methacrylamide group.

13. The adhesive composition of claim 1 or 2, further comprising a crosslinker B.

14. An adhesive layer formed from the adhesive composition of any one of claims 1-13.

15. The adhesive layer according to claim 14, which satisfies the following formula (3):

A(405)≥0.5 (3)

in the formula (3), A (405) represents absorbance at a wavelength of 405 nm.

16. The adhesive layer of claim 15, further satisfying the following formula (4):

A(405)/ A(440)≥5 (4)

in the formula (4), A (405) represents absorbance at a wavelength of 405nm, and A (440) represents absorbance at a wavelength of 440 nm.

17. An optical laminate comprising an optical film laminated on at least one of the adhesive layers of any one of claims 14 to 16.

18. The optical stack of claim 17 wherein,

the optical film is a polarizing plate.

19. An image display device comprising the optical laminate of claim 18.