JP7580504B2 - Optical Film - Google Patents

Description

The present invention relates to an optical film.

Display devices such as organic EL display devices and liquid crystal display devices (FPD: flat panel displays) use various components, including display elements such as organic EL elements and liquid crystal cells, and optical films such as polarizing plates. The organic EL compounds and liquid crystal compounds used in these components are organic, and therefore degradation due to ultraviolet (UV) rays is likely to be a problem. To solve this problem, for example, Patent Document 1 describes a polarizing plate in which an ultraviolet absorbing agent with excellent ultraviolet absorbing ability in the wavelength range of 370 nm or less has been added to the protective film of the polarizing plate.

JP 2006-308936 A

In addition, as display devices have become thinner in recent years, liquid crystal retardation films made by aligning and photocuring polymerizable liquid crystal compounds have been developed. It has become clear that these liquid crystal retardation films and organic EL light-emitting devices tend to deteriorate not only due to ultraviolet rays, but also due to short-wavelength visible light. However, even though the polarizing plate described in Patent Document 1 has excellent ultraviolet absorption ability in the wavelength range of 370 nm or less, it has low absorption performance for visible light around 400 nm, and there are cases where the deterioration of the liquid crystal retardation film and the organic EL light-emitting device is not sufficiently suppressed. Furthermore, better display characteristics have been required for display devices in recent years.

The object of the present invention is to provide an optical film that has an excellent function of suppressing the deterioration of retardation films and organic EL light-emitting elements caused by short-wavelength visible light.

The present invention includes the following inventions.
[1] An optical film formed from a resin composition containing a resin (A) and a light selective absorption compound (B),
The resin (A) is at least one resin selected from the group consisting of a cellulose-based resin, a (meth)acrylic-based resin, a polyester-based resin, a polyamide-based resin, a polyimide-based resin, and a cycloolefin-based resin;
An optical film satisfying the following formula (1):
A(405)≧0.5 (1)
[In formula (1), A(405) represents absorbance at a wavelength of 405 nm.]
[2] The optical film according to [1], which satisfies the following formula (2):
A(440)≦0.1 (2)
[In formula (2), A(440) represents absorbance at a wavelength of 440 nm.]
[3] The optical film according to [1] or [2], further satisfying the following formula (3):
A(405)/A(440)≧5 (3)
[In formula (3), A(405) represents the absorbance at a wavelength of 405 nm, and A(440) represents the absorbance at a wavelength of 440 nm.]
[4] The optical film according to any one of [1] to [3], wherein the content of the light selective absorption compound (B) is 0.01 to 20 parts by mass per 100 parts by mass of the resin (A).
[5] The optical film according to any one of [1] to [4], wherein the resin (A) has a storage modulus E at 23° C. of 100 MPa or more.
[6] The optical film according to any one of [1] to [5], wherein the light selective absorption compound (B) is a compound satisfying formula (4):
ε(405)≧20 (4)
(In formula (4), ε(405) represents the gram absorption coefficient of the compound at a wavelength of 405 nm. The unit of the gram absorption coefficient is L/(g cm).)
[7] The optical film according to [6], wherein the light selective absorption compound (B) is a compound satisfying formula (5).
ε(405)/ε(440)≧20 (5)
[In formula (6), ε(405) represents the gram absorbance coefficient of the compound at a wavelength of 405 nm, and ε(440) represents the gram absorbance coefficient at a wavelength of 440 nm.]
[8] The optical film according to any one of [1] to [7], wherein the light selective absorption compound (B) is a compound having a merocyanine structure in the molecule.
[9] An optical film with a pressure-sensitive adhesive, comprising the optical film according to any one of [1] to [8], and a pressure-sensitive adhesive layer on at least one surface of the optical film.
[10] A display device having the optical film according to [9].

The optical film of the present invention exhibits high absorption selectivity for short-wavelength visible light around 405 nm, and therefore has a good function of suppressing deterioration of retardation films and organic EL light-emitting elements caused by short-wavelength visible light. In addition, the optical film of the present invention exhibits high absorption selectivity for short-wavelength visible light around 405 nm even after weather resistance testing, and can maintain the suppression of deterioration caused by short-wavelength visible light even after weather resistance testing. When the optical film of the present invention is used in a display device, it can provide good display characteristics and durability.

1 is a schematic cross-sectional view showing an example of a pressure-sensitive adhesive layer-attached optical film according to the present invention. FIG. 1 is a schematic cross-sectional view showing an example of a laminate including an optical film according to the present invention. FIG. 1 is a schematic cross-sectional view showing an example of a laminate including an optical film according to the present invention. FIG. 1 is a schematic cross-sectional view showing an example of a laminate including an optical film according to the present invention. FIG. 1 is a schematic cross-sectional view showing an example of a laminate including an optical film according to the present invention.

The optical film of the present invention is an optical film formed from a resin composition containing a resin (A) and a light selective absorption compound (B),
The resin (A) is at least one resin selected from the group consisting of cellulose-based resins, (meth)acrylic-based resins, polyester-based resins, polyamide-based resins, polyimide-based resins, and cycloolefin-based resins, and is characterized in that it satisfies the following formula (1):
A(405)≧0.5 (1)
[In formula (1), A(405) represents absorbance at a wavelength of 405 nm.]

The larger the value of A(405), the higher the absorption at a wavelength of 405 nm. If the value of A(405) is less than 0.5, the absorption at a wavelength of 405 nm is low, and deterioration of displays such as organic EL elements and retardation films in short-wavelength visible light is likely to occur. The value of A(405) is preferably 0.6 or more, more preferably 0.8 or more, and particularly preferably 1.0 or more. There is no particular upper limit, but it is usually 10 or less.

It is preferable that the optical film of the present invention further satisfies the following formula (2).
A(440)≦0.1 (2)
[In formula (2), A(440) represents absorbance at a wavelength of 440 nm.]
The smaller the value of A(440), the lower the absorption at a wavelength of 440 nm. If the value of A(440) exceeds 0.1, the better color expression in the display device tends to be impaired. In addition, the luminance is also reduced because the luminance of the display device is inhibited. The value of A(440) is preferably 0.05 or less, more preferably 0.04 or less, and particularly preferably 0.03. There is no particular lower limit, but it is usually 0.00001 or more.

It is preferable that the optical film of the present invention further satisfies the following formula (3).
A(405)/A(440)≧5 (3)
[In formula (3), A(405) represents the absorbance at a wavelength of 405 nm, and A(440) represents the absorbance at a wavelength of 440 nm.]
The value of A(405)/A(440) represents the magnitude of absorption at a wavelength of 405 nm relative to the magnitude of absorption at a wavelength of 440 nm, and the larger this value is, the more specific absorption there is in the wavelength region around 405 nm. The value of A(405)/A(440) is preferably 10 or more, more preferably 30 or more, and particularly preferably 60 or more.

The optical film of the present invention has a storage modulus E' at 23°C of usually 100 MPa or more, preferably 300 MPa or more, more preferably 500 MPa or more, further preferably 1000 MPa or more, and particularly preferably 3500 MPa or more. There is no lower limit, but it is usually 100,000 MPa or less.
The storage modulus at 23° C. of the optical film of the present invention can be measured by the method described in the examples.

The optical film of the present invention is formed from a resin composition (hereinafter sometimes referred to as "resin composition (1)") containing a resin (A) and a selective light absorbing compound (B).
The resin (A) is at least one resin selected from the group consisting of cellulose-based resins, (meth)acrylic-based resins, polyester-based resins, polyamide-based resins, polyimide-based resins, and cycloolefin-based resins.

The cellulose resin is preferably a cellulose ester resin, that is, a resin in which at least a part of the hydroxyl groups in cellulose are esterified with acetate, and may be a mixed ester in which a part is esterified with acetate and a part is esterified with another acid.The cellulose ester resin is preferably an acetyl cellulose resin.Specific examples of the acetyl cellulose resin include triacetyl cellulose, diacetyl cellulose, cellulose acetate propionate, and cellulose acetate butyrate.
The raw cotton material for acetyl cellulose can be cellulose raw materials such as wood pulp and cotton linters, which are known in the Japan Institute of Invention and Innovation's Disclosure Techniques 2001-1745, etc. Acetyl cellulose can be synthesized by the method described in Wood Chemistry, pp. 180-190 (Kyoritsu Shuppan, Migita et al., 1968), etc.
Commercially available triacetyl cellulose products include those available from Fuji Film Corporation under the trade names "UV-50", "UV-80", "SH-80", "TD-80U", "TD-TAC", and "UZ-TAC".

Examples of the (meth)acrylic resin include homopolymers of methacrylic acid alkyl esters or acrylic acid alkyl esters, and copolymers of methacrylic acid alkyl esters and acrylic acid alkyl esters. Specific examples of the methacrylic acid alkyl esters include methyl methacrylate, ethyl methacrylate, and propyl methacrylate, and specific examples of the acrylic acid alkyl esters include methyl acrylate, ethyl acrylate, and propyl acrylate. As the (meth)acrylic resin, a commercially available general-purpose (meth)acrylic resin can be used. As the (meth)acrylic resin, a resin called impact-resistant (meth)acrylic resin can be used.
Specific examples of the (meth)acrylic resin include "ACRYPET VH" and "ACRYPET VRL20A" manufactured by Mitsubishi Rayon Co., Ltd.

A polyester resin is a polymer resin having repeating units of ester bonds in the main chain, and is generally obtained by condensation polymerization of a polyvalent carboxylic acid or a derivative thereof and a polyhydric alcohol or a derivative thereof.
Examples of polyvalent carboxylic acids or derivatives thereof which give polyesters include aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, phthalic acid, 2,6-naphthalenedicarboxylic acid, diphenyldicarboxylic acid, diphenylsulfonedicarboxylic acid, diphenoxyethanedicarboxylic acid, and 5-sodiumsulfonedicarboxylic acid, aliphatic dicarboxylic acids such as oxalic acid, succinic acid, adipic acid, sebacic acid, dimer acid, maleic acid, and fumaric acid, alicyclic dicarboxylic acids such as 1,4-cyclohexanedicarboxylic acid, and oxycarboxylic acids such as paraoxybenzoic acid, as well as derivatives thereof. Examples of derivatives of dicarboxylic acids include esters of dimethyl terephthalate, diethyl terephthalate, 2-hydroxyethyl methyl terephthalate, dimethyl 2,6-naphthalenedicarboxylate, dimethyl isophthalate, dimethyl adipate, diethyl maleate, and dimethyl dimerate. Among these, from the viewpoints of moldability and handling, terephthalic acid, isophthalic acid, 2,6-naphthalenedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, and esters thereof are preferably used.
Examples of polyhydric alcohols or derivatives thereof which give polyesters include aliphatic dihydroxy compounds such as ethylene glycol, diethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, and neopentyl glycol, polyoxyalkylene glycols such as diethylene glycol, polyethylene glycol, polypropylene glycol, and polytetramethylene glycol, alicyclic dihydroxy compounds such as 1,4-cyclohexanedimethanol and spiroglycol, aromatic dihydroxy compounds such as bisphenol A and bisphenol S, and derivatives thereof. Among these, in terms of moldability and handling properties, ethylene glycol, diethylene glycol, 1,3-propanediol, 1,4-butanediol, neopentyl glycol, and 1,4-cyclohexanedimethanol are preferably used.
Examples of polyester resins include polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, polytrimethylene terephthalate, polytrimethylene naphthalate, polycyclohexane dimethyl terephthalate, polycyclohexane dimethyl naphthalate, etc. Among these, polyethylene terephthalate or polyethylene naphthalate is preferred.

Polyamide resins are polymer resins containing amide bonds in the repeating units of the main chain, such as aromatic polyamides (aramids) in which aromatic ring skeletons are bonded by amide bonds, aliphatic polyamides in which aliphatic skeletons are bonded by amide bonds, etc. Polyamide resins can generally be obtained by polymerization reaction between polyvalent carboxylic acids or their derivatives and polyvalent amines.
Examples of polyvalent carboxylic acids or derivatives thereof which give polyamides include terephthalic acid chloride, 2-chloro-terephthalic acid chloride, isophthalic acid dichloride, naphthalene dicarbonyl chloride, biphenyl dicarbonyl chloride, and terphenyl dicarbonyl chloride.
Examples of polyamines that give polyamides include 4,4'-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, 4,4'-diaminodiphenyl sulfone, 3,3'-diaminodiphenyl sulfone, 2,2'-ditrifluoromethyl-4,4'-diaminobiphenyl, 9,9-bis(4-aminophenyl)fluorene, 9,9-bis(4-amino-3-methylphenyl)fluorene, bis[4-(4-aminophenoxy)phenyl]sulfone, and bis[4-(3-aminophenoxy)phenyl]sulfone. Examples of suitable amines include 2,2-bis[4-(4-aminophenoxy)phenyl]propane, 2,2-bis(4-aminophenyl)hexafluoropropane, and the like. Of these, preferred are 4,4'-diaminodiphenyl sulfone, 3,3'-diaminodiphenyl sulfone, 2,2'-ditrifluoromethyl-4,4'-diaminobiphenyl, 9,9-bis(4-aminophenyl)fluorene, 9,9-bis(4-amino-3-methylphenyl)fluorene, 1,4-cyclohexanediamine, and 1,4-norbornenediamine.

Polyimide resins are polymer resins containing imide bonds in the repeating units of the main chain, and are generally condensation-type polyimides obtained by polycondensation using diamines and tetracarboxylic dianhydrides as starting materials. As diamines, aromatic diamines, alicyclic diamines, aliphatic diamines, etc. can be used. As tetracarboxylic dianhydrides, aromatic tetracarboxylic dianhydrides, alicyclic tetracarboxylic dianhydrides, acyclic aliphatic tetracarboxylic dianhydrides, etc. can be used. The diamines and tetracarboxylic dianhydrides may be used alone or in combination of two or more. Instead of tetracarboxylic dianhydrides, tetracarboxylic acid compounds selected from tetracarboxylic acid compound analogs such as acid chloride compounds may be used as starting materials.

Cycloolefin resins are thermoplastic resins having monomer units made of cyclic olefins (cycloolefins) such as norbornene and polycyclic norbornene monomers, and are also called thermoplastic cycloolefin resins. These cycloolefin resins may be ring-opening polymers of the above cycloolefins or hydrogenated ring-opening copolymers using two or more cycloolefins, or may be addition polymers of cycloolefins and linear olefins or aromatic compounds having polymerizable double bonds such as vinyl groups. Polar groups may be introduced into the cycloolefin resins.

When the first protective film is formed using a copolymer of a cycloolefin and a linear olefin and/or an aromatic compound having a vinyl group, examples of the linear olefin include ethylene and propylene, and examples of the aromatic compound having a vinyl group include styrene, α-methylstyrene, and nuclear alkyl-substituted styrene. In such a copolymer, the monomer unit consisting of the cycloolefin may be 50 mol % or less, but is preferably about 15 to 50 mol %. In particular, when the first protective film is formed using a ternary copolymer of a cycloolefin, a linear olefin, and an aromatic compound having a vinyl group, the monomer unit consisting of the cycloolefin can be relatively small as described above. In such a ternary copolymer, the monomer unit consisting of the linear olefin is usually 5 to 80 mol %, and the monomer unit consisting of the aromatic compound having a vinyl group is usually 5 to 80 mol %.

As the cycloolefin resin, an appropriate commercially available product can be used. For example, "TOPAS" sold by Polyplastics Co., Ltd., "Arton" sold by JSR Corporation, "ZEONOR" and "ZEONEX" sold by Zeon Corporation, and "Apel" sold by Mitsui Chemicals, Inc. (all of the above are product names) can be mentioned.

The storage modulus E of resin (A) at 23°C is usually 100 MPa or more, preferably 300 MPa or more, more preferably 500 MPa or more, and particularly preferably 1000 MPa or more. There is no lower limit, but it is usually 100,000 MPa or less.

The light selective absorption compound (B) is a compound that selectively absorbs light having a wavelength of 405 nm, and is preferably a compound that satisfies the following formula (4), and more preferably a compound that satisfies formula (5).
ε(405)≧20 (4)
(In formula (4), ε(405) represents the gram absorption coefficient of the compound at a wavelength of 405 nm. The unit of the gram absorption coefficient is L/(g cm).)
ε(405)/ε(440)≧20 (5)
[In formula (6), ε(405) represents the gram absorbance coefficient of the compound at a wavelength of 405 nm, and ε(440) represents the gram absorbance coefficient at a wavelength of 440 nm.]
The gram absorbance coefficient is measured by the method described in the Examples.

The larger the value of ε(405), the easier it is for the compound to absorb light with a wavelength of 405 nm, and the easier it is for the compound to exhibit a function of suppressing deterioration caused by ultraviolet light or short-wavelength visible light. If the value of ε(405) is less than 20 L/(g·cm), the content of the light-selective absorbing compound (B) in the resin composition of the present invention is increased in order to exhibit a function of suppressing deterioration caused by ultraviolet light or short-wavelength visible light in retardation films and organic EL light-emitting devices. If the content of the light-selective absorbing compound (B) is increased, the light-selective absorbing compound (B) may bleed out or disperse unevenly, resulting in insufficient light absorption function. The value of ε(405) is preferably 20 L/(g·cm) or more, more preferably 30 L/(g·cm) or more, even more preferably 40 L/(g·cm) or more, and is usually 500 L/(g·cm) or less.

The larger the value of ε(405)/ε(440), the more the compound can absorb light around 405 nm and suppress photodegradation of displays such as retardation films and organic EL elements without impeding the color expression of the display. The value of ε(405)/ε(440) is preferably 20 or more, more preferably 40 or more, even more preferably 70 or more, and particularly preferably 80 or more.

［式中、Ｒ^１及びＲ^５は、それぞれ独立して、水素原子、置換基を有していてもよい炭素数１～２５のアルキル基、置換基を有していてもよい炭素数７～１５のアラルキル基、炭素数６～１５のアリール基、複素環基を表し、該アルキル基又はアラルキル基に含まれる－ＣＨ_２－は－ＮＲ^１Ａ－、－ＣＯ－、－ＳＯ_２－、－Ｏ－又は－Ｓ－に置換されていてもよい。
Ｒ^１Ａは、水素原子又は炭素数１～６のアルキル基を表す。
Ｒ^２、Ｒ^３及びＲ^４は、それぞれ独立して、水素原子、置換基を有していてもよい炭素数１～６のアルキル基、置換基を有していてもよい芳香族炭化水素基又は置換基を有していてもよい芳香族複素環基を表し、該アルキル基に含まれる－ＣＨ_２－は－ＮＲ^１Ｂ－、－ＣＯ－、－ＳＯ_２－、－Ｏ－又は－Ｓ－で置換されていてもよい。
Ｒ^１Ｂは、水素原子又は炭素数１～６のアルキル基を表す。
Ｒ^６及びＲ^７は、それぞれ独立して、水素原子、炭素数１～２５のアルキル基又は電子吸引性基を表すか、Ｒ^６及びＲ^７が互いに連結して環構造を形成してもよい。
Ｒ^１及びＲ^２は互いに連結して環構造を形成してもよく、Ｒ^２及びＲ^３は互いに連結して環構造を形成してもよく、Ｒ^２及びＲ^４は互いに連結して環構造を形成してもよく、Ｒ^３及びＲ^６は、互いに連結して環構造を形成してもよい。］ Moreover, the light selective absorption compound (B) is preferably a compound containing a merocyanine structure in the molecule. Examples of compounds containing a merocyanine structure in the molecule include compounds containing a partial structure represented by -(N-C=C-C=C)- in the molecule, such as merocyanine compounds, cyanine compounds, indole compounds, and benzotriazole compounds. Merocyanine compounds, cyanine compounds, and benzotriazole compounds are preferred, and compounds represented by formula (I) are more preferred.

[In the formula, R ¹ and R ⁵ each independently represent a hydrogen atom, an alkyl group having 1 to 25 carbon atoms which may have a substituent, an aralkyl group having 7 to 15 carbon atoms which may have a substituent, an aryl group having 6 to 15 carbon atoms, or a heterocyclic group, and -CH ₂ - contained in the alkyl group or aralkyl group may be substituted with -NR ^1A -, -CO-, -SO ₂ -, -O- or -S-.
R ^1A represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms.
R ² , R ³ and R ⁴ each independently represent a hydrogen atom, an alkyl group having 1 to 6 carbon atoms which may have a substituent, an aromatic hydrocarbon group which may have a substituent or an aromatic heterocyclic group which may have a substituent, and -CH ₂ - contained in the alkyl group may be substituted with -NR ^1B -, -CO-, -SO ₂ -, -O- or -S-.
R ^1B represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms.
R ⁶ and R ⁷ each independently represent a hydrogen atom, an alkyl group having 1 to 25 carbon atoms, or an electron-withdrawing group, or R ⁶ and R ⁷ may be bonded to each other to form a ring structure.
^R1 and ^R2 may be linked together to form a ring structure, ^R2 and ^R3 may be linked together to form a ring structure, ^R2 and ^R4 may be linked together to form a ring structure, and ^R3 and ^R6 may be linked together to form a ring structure.

Examples of the alkyl group having 1 to 25 carbon atoms represented by ^R1 and ^R5 include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, a 2-cyanopropyl group, an n-butyl group, a tert-butyl group, a sec-butyl group, an n-pentyl group, an n-hexyl group, a 1-methylbutyl group, a 3-methylbutyl group, an n-octyl group, an n-decyl group, and a 2-hexyl-octyl group.
Examples of the substituent that the alkyl group having 1 to 25 carbon atoms represented by R ¹ and R ⁵ may have include the groups described in Group A below.
Group A: a nitro group, a hydroxy group, a carboxy group, a sulfo group, a cyano group, an amino group, a halogen atom, an alkoxy group having 1 to 6 carbon atoms, an alkylsilyl group having 1 to 12 carbon atoms, an alkylcarbonyl group having 2 to 8 carbon atoms, and a group represented by *-R ^a1 -(O-R ^a2 ) _t1 -R ^a3 (R ^a1 and R ^a2 each independently represent an alkanediyl group having 1 to 6 carbon atoms, R ^a3 represents an alkyl group having 1 to 6 carbon atoms, and s1 represents an integer of 1 to 3).
Examples of the alkylsilyl group having 1 to 12 carbon atoms include monoalkylsilyl groups such as methylsilyl group, ethylsilyl group, and propylsilyl group; dialkylsilyl groups such as dimethylsilyl group, diethylsilyl group, and methylethylsilyl group; and trialkylsilyl groups such as trimethylsilyl group, triethylsilyl group, and tripropylsilyl group.
Examples of the alkylcarbonyl group having 2 to 8 carbon atoms include a methylcarbonyl group and an ethylcarbonyl group.
Examples of the halogen atom include a fluorine atom, a chlorine atom, and a bromine atom.

Examples of the aralkyl group having 7 to 15 carbon atoms represented by ^R1 and ^R5 include a benzyl group, a phenylethyl group, etc. Examples of the group in which —CH ₂ — contained in the aralkyl group is replaced by —SO ₂ — or —COO— include 2-phenylethyl acetate.
Examples of the substituent that the aralkyl group having 7 to 15 carbon atoms represented by R ¹ and R ⁵ may have include the groups described in Group A below.
Examples of the aryl group having 6 to 15 carbon atoms represented by ^R1 and ^R5 include a phenyl group, a naphthyl group, and an anthracenyl group.
Examples of the substituent that the aryl group having 6 to 15 carbon atoms represented by R ¹ and R ⁵ may have include the groups described in Group A above.
Examples of the heterocyclic group having 6 to 15 carbon atoms represented by ^R1 and ^R5 include aromatic heterocyclic groups having 3 to 9 carbon atoms, such as a pyridyl group, a pyrrolidyl group, a quinolyl group, a thiophene group, an imidazolyl group, an oxazolyl group, a pyrrole group, a thiazolyl group, and a furanyl group.

Examples of the alkyl group having 1 to 6 carbon atoms represented by R ^1A and R ^1B include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a tert-butyl group, a sec-butyl group, an n-pentyl group, and an n-hexyl group.

Examples of the alkyl group having 1 to 6 carbon atoms represented by R ² , R ³ and R ⁴ include the same as the alkyl group having 1 to 6 carbon atoms represented by R ^1B .
Examples of the substituent that the alkyl group having 1 to 6 carbon atoms represented by R ² , R ³ and R ⁴ may have include the groups described in group A above.
Examples of the aromatic hydrocarbon groups represented by R ² , R ³ and R ⁴ include aryl groups having 6 to 15 carbon atoms, such as a phenyl group, a naphthyl group and an anthracenyl group; and aralkyl groups having 7 to 15 carbon atoms, such as a benzyl group and a phenylethyl group.
Examples of the substituent that the aromatic hydrocarbon group represented by R ² , R ³ and R ⁴ may have include the groups described in Group A above.
Examples of the aromatic heterocyclic ring represented by R ² , R ³ and R ⁴ include aromatic heterocyclic groups having 3 to 9 carbon atoms, such as a pyridyl group, a pyrrolidyl group, a quinolyl group, a thiophene group, an imidazolyl group, an oxazolyl group, a pyrrole group, a thiazolyl group and a furanyl group.
Examples of the substituent that the aromatic heterocycle represented by R ² , R ³ and R ⁴ may have include the groups described in Group A above.

Examples of the alkyl group having 1 to 25 carbon atoms represented by ^R6 and ^R7 include the same as the alkyl group having 1 to 25 carbon atoms represented by ^R1 and ^R5 .
Examples of the substituent that the alkyl group having 1 to 25 carbon atoms represented by R ⁶ and R ⁷ may have include the groups described in Group A above.

［式中、Ｒ^１１は、水素原子又は炭素数１～２５のアルキル基を表し、該アルキル基に含まれるメチレン基の少なくとも１つは酸素原子に置換されていてもよい。
Ｘ^１は、－ＣＯ－、－ＣＯＯ－、－ＯＣＯ－、－ＣＳ－、－ＣＳＯ－、－ＣＳＳ－、－ＮＲ^１２ＣＯ－又はＣＯＮＲ^１３－を表す。
Ｒ^１２及びＲ^１３は、それぞれ独立して、水素原子、炭素数１～６のアルキル基又はフェニル基を表す。］ Examples of the alkyl group having 1 to 25 carbon atoms represented by ^R6 and ^R7 include the same as the alkyl group having 1 to 25 carbon atoms represented by ^R1 and ^R5 .
Examples of the electron-withdrawing group represented by R ⁶ and R ⁷ include a cyano group, a nitro group, a halogen atom, an alkyl group substituted with a halogen atom, and a group represented by formula (I-1).

In the formula, R ¹¹ represents a hydrogen atom or an alkyl group having 1 to 25 carbon atoms, and at least one methylene group contained in the alkyl group may be substituted with an oxygen atom.
X ¹ represents —CO—, —COO—, —OCO—, —CS—, —CSO—, —CSS—, —NR ¹² CO— or —CONR ¹³ —.
R ¹² and R ¹³ each independently represent a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or a phenyl group.

Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.
Examples of the alkyl group substituted with a halogen atom include perfluoroalkyl groups such as a trifluoromethyl group, a perfluoroethyl group, a perfluoropropyl group, a perfluoroisopropyl group, a perfluorobutyl group, a perfluorosec-butyl group, a perfluorotert-butyl group, a perfluoropentyl group, and a perfluorohexyl group. The number of carbon atoms in the alkyl group substituted with a halogen atom is usually 1 to 25.

R ⁶ and R ⁷ may be bonded to each other to form a ring structure. Examples of the ring structure formed by R ⁶ and R ⁷ include a Meldrum's acid structure, a barbituric acid structure, and a dimedone structure.
Examples of the alkyl group having 1 to 25 carbon atoms represented by R ¹¹ include the same alkyl groups as those represented by R ¹ and R ⁵ .

The ring structure formed by ^R2 and ^R3 bonding to each other is a nitrogen-containing ring structure containing the nitrogen atom bonded to ^R2 , and examples of such ring structures include 4- to 14-membered nitrogen-containing heterocycles. The ring structure formed by ^R2 and ^R3 bonding to each other may be a monocycle or a polycycle. Specific examples of such ring structures include a pyrrolidine ring, a pyrroline ring, an imidazolidine ring, an imidazoline ring, an oxazoline ring, a thiazoline ring, a piperidine ring, a morpholine ring, a piperazine ring, an indole ring, and an isoindole ring.

The ring structure formed by ^R1 and ^R2 bonding to each other is a nitrogen-containing ring structure containing the nitrogen atom to which ^R1 and ^R2 are bonded, and examples of such ring structures include 4- to 14-membered (preferably 4- to 8-membered) nitrogen-containing heterocycles. The ring structure formed by ^R1 and ^R2 bonding to each other may be a monocycle or a polycycle. Specific examples of such ring structures include the same ring structure as the ring structure formed by ^R2 and ^R3 bonding to each other.

Examples of the ring structure formed by ^R2 and ^R4 bonding to each other include a 4- to 14-membered nitrogen-containing ring structure, and a 5- to 9-membered nitrogen-containing ring structure is preferred. The ring structure formed by ^R2 and ^R4 bonding to each other may be a monocyclic ring or a polycyclic ring. These rings may have a substituent, and examples of such ring structures include the same as those exemplified as the ring structure formed by ^R2 and ^R3 .

The ring structure formed by ^R3 and ^R6 bonding to each other is a ring structure in which ^R3 -C=C-C=C- ^R6 forms the backbone of the ring, such as a phenyl group.

［式（Ｉ－Ａ）、式（Ｉ－Ｂ）中、Ｒ^１、Ｒ^３、Ｒ^４、Ｒ^５、Ｒ^６及びＲ^７は、それぞれ上記と同じ意味を表す。
環Ｗ^１及び環Ｗ^２は、それぞれ独立して、含窒素環を表す。］ An example of the compound represented by formula (I) in which ^R2 and ^R3 are bonded to each other to form a ring structure is a compound represented by formula (IA). An example of the compound represented by formula (I) in which ^R2 and ^R4 are bonded to each other to form a ring structure is a compound represented by formula (IB).

In formula (IA) and formula (IB), R ¹ , R ³ , R ⁴ , R ⁵ , R ⁶ and R ⁷ each have the same meaning as defined above.
Ring ^W1 and ring ^W2 each independently represent a nitrogen-containing ring.

Ring ^W1 and ring ^W2 each represent a nitrogen-containing ring containing a nitrogen atom as a ring constituent unit. Ring ^W1 and ring W2 each independently may be a monocyclic ring or a polycyclic ring, and may contain a heteroatom other than nitrogen as a ring constituent unit. Ring ^W1 and ring ^W2 each independently are preferably ^5- to 9-membered rings.

［式（Ｉ－Ａ－１）中、Ｒ^１、Ｒ^４、Ｒ^５、Ｒ^６及びＲ^７は、それぞれ上記と同じ意味を表す。
Ａ^１は、－ＣＨ_２－、－Ｏ－、－Ｓ－又は－ＮＲ^１Ｄ－を表す。
Ｒ^１４及びＲ^１５は、それぞれ独立して、水素原子又は炭素数１～１２のアルキル基を表す。
Ｒ^１Ｄは、水素原子又は炭素数１～６のアルキル基を表す。］ The compound represented by formula (IA) is preferably a compound represented by formula (IA-1).

In formula (IA-1), R ¹ , R ⁴ , R ⁵ , R ⁶ and R ⁷ each have the same meaning as defined above.
A ¹ represents —CH ₂ —, —O—, —S— or —NR ^1D —.
R ¹⁴ and R ¹⁵ each independently represent a hydrogen atom or an alkyl group having 1 to 12 carbon atoms.
^R1D represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms.

［式（Ｉ－Ｂ－１）中、Ｒ^１、Ｒ^６及びＲ^７は、それぞれ上記と同じ意味を表す。
Ｒ^１６は、それぞれ独立して、水素原子又は炭素数１～１２のアルキル基、アリール基を表す。］ The compound represented by formula (IB) is preferably a compound represented by formula (IB-1) or a compound represented by formula (IB-2).

In formula (IB-1), R ¹ , R ⁶ and R ⁷ each have the same meaning as defined above.
Each R ¹⁶ independently represents a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, or an aryl group.

［式（Ｉ－Ｂ－２）中、Ｒ^３、Ｒ^５、Ｒ^６及びＲ^７は、それぞれ上記と同じ意味を表す。
Ｒ^３０は、水素原子、シアノ基、ニトロ基、ハロゲン原子、メルカプト基、アミノ基、炭素数１～１２のアルキル基、炭素数１～１２のアルコキシ基、炭素数６～１８の芳香族炭化水素基、炭素数２～１３のアシル基、炭素数２～１３のアシルオキシ基又は炭素数２～１３のアルコキシカルボニル基を表す。
Ｒ^３１は、炭素数１～１２のアルキル基、炭素数１～１２のアルコキシ基、メルカプト基、炭素数１～１２のアルキルチオ基、置換基を有していてもよいアミノ基又は複素環基を表す。］

In formula (IB-2), R ³ , R ⁵ , R ⁶ and R ⁷ each have the same meaning as defined above.
R ³⁰ represents a hydrogen atom, a cyano group, a nitro group, a halogen atom, a mercapto group, an amino group, an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, an aromatic hydrocarbon group having 6 to 18 carbon atoms, an acyl group having 2 to 13 carbon atoms, an acyloxy group having 2 to 13 carbon atoms, or an alkoxycarbonyl group having 2 to 13 carbon atoms.
R ³¹ represents an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, a mercapto group, an alkylthio group having 1 to 12 carbon atoms, an amino group which may have a substituent, or a heterocyclic group.]

Examples of the halogen atom represented by R ³⁰ include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom.
Examples of the acyl group having 2 to 13 ^carbon atoms represented by R ³⁰ include an acetyl group, a propionyl group, and a butyryl group.
Examples of the acyloxy group having 2 to 13 carbon atoms represented by R ³⁰ include a methylcarbonyloxy group, an ethylcarbonyloxy group, a propylcarbonyloxy group, and a butylcarbonyloxy group.
Examples of the alkoxycarbonyl group having 2 to 13 carbon atoms represented by R ³⁰ include a methoxycarbonyl group, an ethoxycarbonyl group, a propoxycarbonyl group, and a butoxycarbonyl group.
Examples of the aromatic hydrocarbon group having 6 to 18 carbon atoms represented by R ³⁰ include aryl groups having 6 to 18 carbon atoms, such as a phenyl group, a naphthyl group, and a biphenyl group; and aralkyl groups having 7 to 18 carbon atoms, such as a benzyl group and a phenylethyl group.
Examples of the alkyl group having 1 to 12 carbon atoms represented by R ³⁰ include the same alkyl groups having 1 to 12 carbon atoms represented by R ¹⁴ .
Examples of the alkyl group having 1 to 12 carbon atoms represented by R ³⁰ include a methoxy group, an ethoxy group, a propoxy group, a butoxy group, and a pentoxy group.
R ³⁰ is preferably an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, an amino group, or a mercapto group.

Examples of the alkyl group having 1 to 12 carbon atoms represented by R ³¹ include the same alkyl groups having 1 to 12 carbon atoms represented by R ¹⁴ .
Examples of the alkoxy group having 1 to 12 carbon atoms represented by R ³¹ include the same alkoxy groups having 1 to 12 carbon atoms represented by R ³⁰ .
Examples of the alkylthio group having 1 to 12 carbon atoms represented by R ³¹ include a methylthio group, an ethylthio group, a propylthio group, a butylthio group, a pentylthio group, and a hexylthio group.
Examples of the amino group which may have a substituent represented by R ³¹ include an amino group; an amino group substituted with one alkyl group having 1 to 8 carbon atoms, such as an N-methylamino group or an N-ethylamino group; an amino group substituted with two alkyl groups having 1 to 8 carbon atoms, such as an N,N-dimethylamino group, an N,N-diethylamino group, or an N,N-methylethylamino group; and the like.
Examples of the heterocycle represented by R ³¹ include nitrogen-containing heterocycles having 4 to 9 carbon atoms, such as a pyrrolidinyl group, a piperidinyl group, and a morpholinyl group.

［式（Ｉ－Ｃ）中、Ｒ^１ _、Ｒ^５及びＲ^７は上記と同じ意味を表す。
Ｒ^２１、Ｒ^２２は、それぞれ独立して、水素原子、炭素数１～１２のアルキル基又はヒドロキシ基を表す。
Ｘ^２及びＸ^３は、それぞれ独立して、－ＣＨ_２－又は－Ｎ（Ｒ^２５Ａ）＝を表す。
Ｒ^２５Ａは、水素原子、炭素数１～２５のアルキル基、置換基を有していてもよい芳香族炭化水素基を表す。］ Examples of the compound represented by formula (I) in which ^R3 and ^R6 are bonded to each other to form a ring structure and ^R2 and ^R4 are bonded to each other to form a ring structure include the compound represented by formula (IC).

In formula (IC), R ¹ _, R ⁵ and R ⁷ are as defined above.
R ²¹ and R ²² each independently represent a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, or a hydroxy group.
^X2 and ^X3 each independently represent _-CH2- or -N( ^R25A )=.
R ^25A represents a hydrogen atom, an alkyl group having 1 to 25 carbon atoms, or an aromatic hydrocarbon group which may have a substituent.]

Examples of the alkyl group having 1 to 25 carbon atoms represented by R ^25A include the same alkyl groups having 1 to 25 carbon atoms represented by R ¹ .
Examples of the aromatic hydrocarbon group represented by R ^25A include aryl groups such as a phenyl group and a naphthyl group, aralkyl groups such as a benzyl group and a phenylethyl group, and a biphenyl group, and are preferably aromatic hydrocarbon groups having 6 to 20 carbon atoms. Examples of the substituent that the aromatic hydrocarbon group represented by R ^25A may have include a hydroxyl group.

It is preferable that ^R3 and ^R6 each independently represent an electron-withdrawing group.

［式（Ｉ－D）中、Ｒ^４、Ｒ⁵、Ｒ⁷は上記と同じ意味を表す。
Ｒ^２5、Ｒ^２6、Ｒ^２7及びＲ^２8は、それぞれ独立して、水素原子、置換基を有してもよい炭素数１～１２のアルキル基、ヒドロキシ基、アラルキル基を表す。］ Examples of the compound represented by formula (I) in which ^R1 and ^R2 are bonded to each other to form a ring structure and ^R3 and ^R6 are bonded to each other to form a ring structure include a compound represented by formula (ID).

[In formula (ID), R ⁴ , R ⁵ and R ⁷ have the same meanings as above.
R ²⁵ , R ²⁶ , R ²⁷ and R ²⁸ each independently represent a hydrogen atom, an alkyl group having 1 to 12 carbon atoms which may have a substituent, a hydroxyl group or an aralkyl group.]

Examples of the alkyl group having 1 to 12 carbon atoms represented by R ²⁵ , R ²⁶ , R ²⁷ , and R ²⁸ include the same as the alkyl group having 1 to 12 carbon atoms represented by R ^1A and R ^1B . Examples of the substituent that the alkyl group having 1 to 12 carbon atoms represented by R ²⁵ , R ²⁶ , R ²⁷ , and R ²⁸ may have include a hydroxy group.
Examples of the aralkyl group represented by R ²⁵ , R ²⁶ , R ²⁷ and R ²⁸ include aralkyl groups having 7 to 15 carbon atoms, such as a benzyl group and a phenylethyl group.

［式（Ｉ－Ｅ）中、Ｒ^１、Ｒ^２、Ｒ^３、Ｒ^４、Ｒ^５は、それぞれ上記と同じ意味を表す。
環Ｗ^３は、環状化合物を表す]
環Ｗ^３は、５員環～９員環の環であり、窒素原子、酸素原子、硫黄原子等のヘテロ原子を環の構成単位として含んでいてもよい。 Examples of compound (I) in which R ⁶ and R ⁷ are linked to each other to form a ring structure include a compound represented by formula (IE).

In formula (IE), R ¹ , R ² , R ³ , R ⁴ and R ⁵ each have the same meaning as defined above.
Ring ^W3 represents a cyclic compound.
Ring ^W3 is a 5- to 9-membered ring, which may contain a heteroatom such as a nitrogen atom, an oxygen atom or a sulfur atom as a constituent unit of the ring.

［式（Ｉ－Ｃ－１）中、Ｒ^１、Ｒ^２、Ｒ^３及びＲ^５は、それぞれ上記と同じ意味を表す。
Ｒ^１７、Ｒ^１８、Ｒ^１９、Ｒ^ｑは、それぞれ独立して、水素原子又は置換基を有してもよい炭素数１～１２のアルキル基、アラルキル基、アリール基を表し、該アルキル基又はアラルキル基に含まれる－ＣＨ_２－基は－ＮＲ^１Ｄ－、－Ｃ（＝Ｏ）－、－Ｃ（＝Ｓ）－、－Ｏ－、－Ｓ－に置換されていてもよく、Ｒ^１７及びＲ^１８は互いに連結して環構造を形成してもよく、Ｒ^１８及びＲ^１９は互いに連結して環構造を形成してもよく、Ｒ^１９及びＲ^ｑは、互いに連結して環構造を形成してもよい。ｍ、ｐ、ｑはそれぞれ独立して０～３の整数を表す。］ The compound represented by formula (IE) is preferably a compound represented by formula (IE-1).

In formula (IC-1), R ¹ , R ² , R ³ and R ⁵ each have the same meaning as defined above.
R ¹⁷ , R ¹⁸ , R ¹⁹ and R ^q each independently represent a hydrogen atom or an alkyl group, aralkyl group or aryl group having 1 to 12 carbon atoms which may have a substituent, the -CH ₂ - group contained in the alkyl group or aralkyl group may be substituted with -NR ^1D -, -C(═O)-, -C(═S)-, -O- or -S-, R ¹⁷ and R ¹⁸ may be bonded to each other to form a ring structure, R ¹⁸ and R ¹⁹ may be bonded to each other to form a ring structure, and R ¹⁹ and R ^q may be bonded to each other to form a ring structure. m, p and q each independently represent an integer of 0 to 3.]

Examples of the compound represented by formula (I) include the following compounds.

The content of the light selective absorbing compound (B) is usually 0.01 to 20 parts by mass, preferably 0.05 to 15 parts by mass, more preferably 0.1 to 10 parts by mass, and even more preferably 0.1 to 5 parts by mass, per 100 parts by mass of the resin (A).

The resin composition (1) may further contain a plasticizer, an organic acid, a dye, an antistatic agent, a surfactant, a lubricant, a flame retardant, a filler, rubber particles, a retardation adjuster, an ultraviolet absorber, etc.

As a method for producing the optical film of the present invention, any suitable molding method can be adopted. Specific examples include compression molding, transfer molding, injection molding, extrusion molding, blow molding, powder molding, FRP molding, cast coating (e.g., casting), calendar molding, and heat pressing. Extrusion molding and cast coating are preferred because they can increase the smoothness of the resulting film and provide good optical uniformity. The molding conditions can be appropriately set depending on the composition and type of the resin used, the properties desired for the retardation film, and the like.

The thickness of the optical film of the present invention is usually from 1 to 500 μm, preferably from 5 to 300 μm, more preferably from 10 to 150 μm, and particularly preferably from 10 to 75 μm.
The optical film of the present invention may be unstretched or stretched. When the optical film of the present invention is stretched, it may be uniaxially stretched or biaxially stretched. The stretching ratio is usually 1.01 to 10 times, preferably 1.01 to 6 times. The stretching direction may be various directions or dimensions, such as the length direction, width direction, thickness direction, and oblique direction.

The pressure-sensitive adhesive layer-attached optical film of the present invention is a film having a pressure-sensitive adhesive layer on at least one surface of the optical film of the present invention. The pressure-sensitive adhesive layer is formed from a known pressure-sensitive adhesive. The known pressure-sensitive adhesive may be any pressure-sensitive adhesive having a base polymer such as an acrylic, rubber, urethane, silicone, or polyvinyl ether type, but is preferably an acrylic pressure-sensitive adhesive composition containing a (meth)acrylic resin (A) as a base polymer.

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

［式（Ｉ）中、Ｒ₁ は水素原子又はメチル基で表し、Ｒ₂ は炭素数１～１４のアルキル基または炭素数７～２０のアラルキル基を表し、該アルキル基または該アラルキル基の水素原子は、炭素数１～１０のアルコキシ基で置き換わっていてもよい。］ Examples of the (meth)acrylic acid ester include (meth)acrylic acid esters represented by the following formula (I):

[In formula (I), R ₁ represents a hydrogen atom or a methyl group, R ₂ represents an alkyl group having 1 to 14 carbon atoms or an aralkyl group having 7 to 20 carbon atoms, and the hydrogen atom of the alkyl group or the aralkyl group may be replaced by an alkoxy group having 1 to 10 carbon atoms.]

In formula (I), R ₂ is preferably an alkyl group having 1 to 14 carbon atoms, and more preferably an alkyl group having 1 to 8 carbon atoms.

The (meth)acrylic acid ester represented by formula (I) includes
Linear alkyl esters of (meth)acrylic acid, such as methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, n-butyl (meth)acrylate, n-pentyl (meth)acrylate, n-hexyl (meth)acrylate, n-heptyl (meth)acrylate, n-octyl (meth)acrylate, n-nonyl (meth)acrylate, n-decyl (meth)acrylate, n-dodecyl (meth)acrylate, lauryl (meth)acrylate, and stearyl (meth)acrylate;
Branched alkyl esters of (meth)acrylic acid, such as i-propyl (meth)acrylate, i-butyl (meth)acrylate, t-butyl (meth)acrylate, i-pentyl (meth)acrylate, i-hexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, i-octyl (meth)acrylate, i-nonyl (meth)acrylate, i-stearyl (meth)acrylate, and i-amyl (meth)acrylate;
Alicyclic skeleton-containing alkyl esters of (meth)acrylic acid, such as cyclohexyl (meth)acrylate, isobornyl (meth)acrylate, adamantyl (meth)acrylate, dicyclopentanyl (meth)acrylate, cyclododecyl (meth)acrylate, methylcyclohexyl (meth)acrylate, trimethylcyclohexyl (meth)acrylate, tert-butylcyclohexyl (meth)acrylate, and cyclohexyl α-ethoxyacrylate;
Aromatic ring skeleton-containing esters of (meth)acrylic acid, such as phenyl (meth)acrylate;
etc.
Further, examples of the substituent-containing (meth)acrylic acid alkyl ester include an alkyl (meth)acrylate having a substituent introduced into the alkyl group. The substituent of the substituent-containing (meth)acrylic acid alkyl ester is a group that substitutes a hydrogen atom of the alkyl group, and specific examples thereof include a phenyl group, an alkoxy group, and a phenoxy group. Specific examples of the substituent-containing (meth)acrylic acid alkyl ester include 2-methoxyethyl (meth)acrylate, ethoxymethyl (meth)acrylate, phenoxyethyl (meth)acrylate, 2-(2-phenoxyethoxy)ethyl (meth)acrylate, phenoxydiethylene glycol (meth)acrylate, and phenoxypoly(ethylene glycol) (meth)acrylate.

These (meth)acrylic acid esters can be used alone or in combination.

The (meth)acrylic resin (A) preferably contains a structural unit derived from an (meth)acrylic acid alkyl ester (a1) whose homopolymer has a glass transition temperature Tg of less than 0°C, and a structural unit derived from a (meth)acrylic acid alkyl ester (a2) whose homopolymer has a Tg of 0°C or higher. The inclusion of a structural unit derived from an acrylic acid alkyl ester (a1) and a structural unit derived from an acrylic acid alkyl ester (a2) is advantageous in terms of improving the high temperature durability of the adhesive layer. For the Tg of the homopolymer of the (meth)acrylic acid alkyl ester, a literature value such as that in the POLYMER HANDBOOK (Wiley-Interscience) can be used.

Specific examples of (meth)acrylic acid alkyl esters (a1) include (meth)acrylic acid alkyl esters having an alkyl group with about 2 to 12 carbon atoms, such as ethyl acrylate, n- and i-propyl acrylate, n- and i-butyl acrylate, n-pentyl acrylate, n- and i-hexyl acrylate, n-heptyl acrylate, n- and i-octyl acrylate, 2-ethylhexyl acrylate, n- and i-nonyl acrylate, n- and i-decyl acrylate, and n-dodecyl acrylate.

The (meth)acrylic acid alkyl ester (a1) may be used alone or in combination of two or more. Among them, n-butyl acrylate, n-octyl acrylate, 2-ethylhexyl acrylate, etc. are preferred from the viewpoint of followability and reworkability when laminated on an optical film.

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

The (meth)acrylic acid alkyl ester (a2) may be used alone or in combination of two or more. Among them, from the viewpoint of high temperature durability, the (meth)acrylic acid alkyl ester (a2) preferably contains methyl acrylate, cyclohexyl acrylate, isobornyl acrylate, etc., and more preferably contains methyl acrylate.

The structural units derived from the (meth)acrylic acid ester represented by formula (I) preferably account for 50% by mass or more of all structural units contained in the (meth)acrylic resin, more preferably 60 to 95% by mass, and even more preferably 65 to 95% by mass or more.

As the structural unit derived from a monomer other than a (meth)acrylic acid ester, a structural unit derived from a monomer having a polar functional group is preferred, and a structural unit derived from a (meth)acrylic acid ester having a polar functional group is more preferred. Examples of the polar functional group include a hydroxyl group, a carboxyl group, a substituted or unsubstituted amino group, and a heterocyclic group such as an epoxy group. Examples of the monomer having a polar functional group include:
1-Hydroxymethyl (meth)acrylate, 1-hydroxyethyl (meth)acrylate, 1-hydroxyheptyl (meth)acrylate, 1-hydroxybutyl (meth)acrylate, 1-hydroxypentyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 2-hydroxypentyl (meth)acrylate, 2-hydroxyhexyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 3-hydroxybutyl (meth)acrylate, 3-hydroxypentyl (meth)acrylate, 3-hydroxyhexyl (meth)acrylate, 3-hydroxyheptyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 4-hydroxypentyl (meth)acrylate, 4-hydroxyhexyl (meth)acrylate, p) 4-hydroxyheptyl acrylate, 4-hydroxyoctyl (meth)acrylate, 2-chloro-2-hydroxypropyl (meth)acrylate, 3-chloro-2-hydroxypropyl (meth)acrylate, 2-hydroxy-3-phenoxypropyl (meth)acrylate, 5-hydroxypentyl (meth)acrylate, 5-hydroxyhexyl (meth)acrylate, 5-hydroxyheptyl (meth)acrylate, 5-hydroxyoctyl (meth)acrylate, 5-hydroxynonyl (meth)acrylate, 6-hydroxyhexyl (meth)acrylate, 6-hydroxyheptyl (meth)acrylate, 6-hydroxyoctyl (meth)acrylate, 6-hydroxynonyl (meth)acrylate, 6-hydroxydecyl (meth)acrylate, 7-hydroxyheptyl (meth)acrylate, 7-hydroxyoctyl (meth)acrylate, ( 7-hydroxynonyl (meth)acrylate, 7-hydroxydecyl (meth)acrylate, 7-hydroxyundecyl (meth)acrylate, 8-hydroxyoctyl (meth)acrylate, 8-hydroxynonyl (meth)acrylate, 8-hydroxydecyl (meth)acrylate, 8-hydroxyundecyl (meth)acrylate, 8-hydroxydodecyl (meth)acrylate, 9-hydroxynonyl (meth)acrylate, 9-hydroxydecyl (meth)acrylate, 9-hydroxyundecyl (meth)acrylate, 9-hydroxydodecyl (meth)acrylate, 9-hydroxytridecyl (meth)acrylate, 10-hydroxydecyl (meth)acrylate, 10-hydroxyundecyl (meth)acrylate, 10-hydroxydodecyl (meth)acrylate, 10-hydroxytridecyl (meth)acrylate, 10-hydroxytetradecyl (meth)acrylate Monomers having a hydroxy group, such as 1-hydroxytetradecyl (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, 14-hydroxypentadecyl (meth)acrylate, 15-hydroxypentadecyl (meth)acrylate, and 15-hydroxyheptadecyl (meth)acrylate;
Monomers having a carboxyl group, such as (meth)acrylic acid, carboxyalkyl (meth)acrylates (for example, carboxyethyl (meth)acrylate, carboxypentyl (meth)acrylate), maleic acid, maleic anhydride, fumaric acid, and crotonic acid;
Monomers having a heterocyclic group, such as acryloylmorpholine, vinylcaprolactam, N-vinyl-2-pyrrolidone, vinylpyridine, tetrahydrofurfuryl (meth)acrylate, caprolactone-modified tetrahydrofurfuryl acrylate, 3,4-epoxycyclohexylmethyl (meth)acrylate, glycidyl (meth)acrylate, and 2,5-dihydrofuran;
Examples of the monomer include monomers having a substituted or unsubstituted amino group, such as aminoethyl (meth)acrylate, N,N-dimethylaminoethyl (meth)acrylate, and dimethylaminopropyl (meth)acrylate.
Among these, from the viewpoint of reactivity between the (meth)acrylic acid ester polymer and the crosslinking agent, a monomer having a hydroxy group or a monomer having a carboxyl group is preferred, and it is more preferred to include both a monomer having a hydroxy group and a monomer having a carboxyl group.

As the monomer having a hydroxy group, 2-hydroxyethyl acrylate, 3-hydroxypropyl acrylate, 4-hydroxybutyl acrylate, 5-hydroxypentyl acrylate, and 6-hydroxyhexyl acrylate are preferred. In particular, good durability can be obtained by using 2-hydroxyethyl acrylate, 4-hydroxybutyl acrylate, and 5-hydroxypentyl acrylate.
As the monomer having a carboxyl group, it is preferable to use acrylic acid.

From the viewpoint of preventing an increase in the peel strength of the separation film that can be laminated on the outer surface of the pressure-sensitive adhesive layer, it is preferable that the resin is substantially free of monomers having amino groups. Here, "substantially free" means that the amount is 0.1 part by weight or less per 100 parts by weight of all constituent units constituting the (meth)acrylic resin (A).

The content of structural units derived from monomers having polar functional groups is preferably 20 parts by mass or less, more preferably 0.5 parts by mass or more and 15 parts by mass or less, even more preferably 0.5 parts by mass or more and 10 parts by mass or less, and particularly preferably 1 part by mass or more and 7 parts by mass or less, relative to 100 parts by mass of all structural units of the (meth)acrylic resin (A).

The content of structural units derived from monomers having an aromatic group is preferably 20 parts by mass or less, more preferably 4 parts by mass or more and 20 parts by mass or less, and even more preferably 4 parts by mass or more and 16 parts by mass or less, relative to 100 parts by mass of all structural units of the (meth)acrylic resin (A).

Examples of structural units derived from monomers other than (meth)acrylic acid esters include structural units derived from styrene-based monomers, structural units derived from vinyl-based monomers, structural units derived from monomers having multiple (meth)acryloyl groups in the molecule, and structural units derived from (meth)acrylamide-based monomers.

Examples of styrene monomers include styrene; alkyl styrenes such as methylstyrene, dimethylstyrene, trimethylstyrene, ethylstyrene, diethylstyrene, triethylstyrene, propylstyrene, butylstyrene, hexylstyrene, heptylstyrene, and octylstyrene; halogenated styrenes such as fluorostyrene, chlorostyrene, bromostyrene, dibromostyrene, and iodostyrene; nitrostyrene; acetylstyrene; methoxystyrene; and divinylbenzene.

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

Examples of monomers having multiple (meth)acryloyl groups in the molecule include monomers having two (meth)acryloyl groups in the molecule, such as 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,9-nonanediol di(meth)acrylate, ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, and tripropylene glycol di(meth)acrylate; and monomers having three (meth)acryloyl groups in the molecule, such as trimethylolpropane tri(meth)acrylate.

Examples of (meth)acrylamide monomers include N-methylol (meth)acrylamide, N-(2-hydroxyethyl) (meth)acrylamide, N-(3-hydroxypropyl) (meth)acrylamide, N-(4-hydroxybutyl) (meth)acrylamide, N-(5-hydroxypentyl) (meth)acrylamide, N-(6-hydroxyhexyl) (meth)acrylamide, N,N-dimethyl (meth)acrylamide, N,N-diethyl (meth)acrylamide, N-isopropyl (meth)acrylamide, N-(3-dimethylaminopropyl) (meth)acrylamide, N-(1,1-dimethyl-3-oxobutyl) (meth)acrylamide, N-[2-(2-oxo-1-imidazolidinyl)ethyl] (meth)acrylamide, 2-acryloylamino-2-methyl-1-propanesulfonic acid, N-(methoxymethyl)acrylamide, N-(ethoxymethyl) (meth)acrylamide, N-(propoxymethyl)(meth)acrylamide, N-(1-methylethoxymethyl)(meth)acrylamide, N-(1-methylpropoxymethyl)(meth)acrylamide, N-(2-methylpropoxymethyl)(meth)acrylamide, N-(butoxymethyl)(meth)acrylamide, N-(1,1-dimethylethoxymethyl)(meth)acrylamide, N-(2-methoxyethyl)(meth)acrylamide, N-(2-ethoxyethyl)(meth)acrylamide Examples of such amides include N-(2-propoxyethyl)(meth)acrylamide, N-[2-(1-methylethoxy)ethyl](meth)acrylamide, N-[2-(1-methylpropoxy)ethyl](meth)acrylamide, N-[2-(2-methylpropoxy)ethyl](meth)acrylamide, N-(2-butoxyethyl)(meth)acrylamide, and N-[2-(1,1-dimethylethoxy)ethyl](meth)acrylamide. Among these, N-(methoxymethyl)acrylamide, N-(ethoxymethyl)acrylamide, N-(propoxymethyl)acrylamide, N-(butoxymethyl)acrylamide, and N-(2-methylpropoxymethyl)acrylamide are preferred.

The weight average molecular weight (Mw) of the (meth)acrylic resin (A) is preferably 500,000 to 2,500,000. When the weight average molecular weight is 500,000 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 and cohesive failure of the adhesive layer are easily suppressed. When the weight average molecular weight is 2,500,000 or less, it is advantageous in terms of coatability when the adhesive composition is processed into a sheet (applied to a substrate). From the viewpoint of achieving both the durability of the adhesive layer and the coatability of the adhesive composition, the weight average molecular weight is preferably 600,000 to 1,800,000, more preferably 700,000 to 1,700,000, and particularly preferably 1,000,000 to 1,600,000. In addition, the molecular weight distribution (Mw/Mn), which is expressed as the ratio of the weight average molecular weight (Mw) to the number average molecular weight (Mn), is usually 2 to 10, preferably 3 to 8, and more preferably 3 to 6.
The weight average molecular weight can be analyzed by gel permeation chromatography and is expressed as a value converted into standard polystyrene.

When the (meth)acrylic resin (A) is dissolved in ethyl acetate to give a solution with a concentration of 20% by mass, the viscosity at 25°C is preferably 20 Pa·s or less, and more preferably 0.1 to 15 Pa·s. A viscosity in this range is advantageous from the viewpoint of coatability when the pressure-sensitive adhesive composition is applied to a substrate. The viscosity can be measured using a Brookfield viscometer.

The glass transition temperature (Tg) of the (meth)acrylic resin (A) may be, for example, -60 to 20°C, preferably -50 to 15°C, more preferably -45 to 10°C, and particularly preferably -40 to 0°C. If the Tg is equal to or less than the upper limit, it is advantageous for improving the wettability of the pressure-sensitive adhesive layer to the substrate, and if it is equal to or more than the lower limit, it is advantageous for improving the durability of the pressure-sensitive adhesive layer. The glass transition temperature can be measured by a differential scanning calorimeter (DSC).

The (meth)acrylic acid resin (A) can be produced by known methods such as solution polymerization, bulk polymerization, suspension polymerization, and emulsion polymerization, with solution polymerization being particularly preferred. An example of the solution polymerization method is a method in which a monomer and an organic solvent are mixed, a thermal polymerization initiator is added in a nitrogen atmosphere, and the mixture is stirred for about 3 to 15 hours at a temperature of 40 to 90°C, preferably about 50 to 80°C. To control the reaction, the monomer or the thermal polymerization initiator may be added continuously or intermittently during polymerization. The monomer or the thermal initiator may be added to the organic solvent.

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

The proportion of the polymerization initiator is about 0.001 to 5 parts by mass per 100 parts by mass of the total amount of the monomers constituting the (meth)acrylic resin. The polymerization of the (meth)acrylic resin may be carried out using a polymerization method using active energy rays (e.g., ultraviolet rays, etc.).

Organic solvents include aromatic hydrocarbons such as toluene and xylene; esters such as ethyl acetate and butyl acetate; aliphatic alcohols such as propyl alcohol and isopropyl alcohol; and ketones such as acetone, methyl ethyl ketone, and methyl isobutyl ketone.

The content of (meth)acrylic resin (A) is usually 60% by mass to 99.9% by mass, preferably 70% by mass to 99.5% by mass, and more preferably 80% by mass to 99% by mass, based on 100% by mass of the adhesive composition.

The adhesive composition may contain a crosslinking agent (b). The crosslinking agent (b) reacts with polar functional groups (e.g., hydroxyl groups, amino groups, carboxyl groups, heterocyclic groups, etc.) in the (meth)acrylic resin (A). The crosslinking agent (B) forms a crosslinked structure with the (meth)acrylic resin, etc., forming a crosslinked structure that is advantageous in terms of durability and reworkability.

Examples of the crosslinking agent (b) include isocyanate-based crosslinking agents, epoxy-based crosslinking agents, aziridine-based crosslinking agents, metal chelate-based crosslinking agents, etc., and from the viewpoints of the pot life of the adhesive composition, the durability of the adhesive layer, the crosslinking speed, etc., it is particularly preferable to use an isocyanate-based crosslinking agent.

As the isocyanate compound, a compound having at least two isocyanato groups (-NCO) in the molecule is preferred, and examples thereof include aliphatic isocyanate compounds (e.g., hexamethylene diisocyanate), alicyclic isocyanate compounds (e.g., isophorone diisocyanate, hydrogenated diphenylmethane diisocyanate, hydrogenated xylylene diisocyanate), aromatic isocyanate compounds (e.g., tolylene diisocyanate, xylylene diisocyanate diphenylmethane diisocyanate, naphthalene diisocyanate, triphenylmethane triisocyanate, etc.). The crosslinking agent (B) may be an adduct of the isocyanate compound with a polyhydric alcohol compound (e.g., an adduct with glycerol, trimethylolpropane, etc.), an isocyanurate, a biuret-type compound, a urethane prepolymer-type isocyanate compound obtained by addition reaction with a polyether polyol, a polyester polyol, an acrylic polyol, a polybutadiene polyol, a polyisoprene polyol, etc. The crosslinking agent (B) may be used alone or in combination of two or more. Among these, representative examples include an aromatic isocyanate compound (e.g., tolylene diisocyanate, xylylene diisocyanate), an aliphatic isocyanate compound (e.g., hexamethylene diisocyanate), or an adduct of these with a polyhydric alcohol compound (e.g., glycerol, trimethylolpropane), or an isocyanurate. If the crosslinking agent (B) is an aromatic isocyanate-based compound and/or an adduct thereof with a polyhydric alcohol compound or an isocyanurate, the durability of the adhesive layer can be improved, possibly because it is advantageous for forming an optimal crosslink density (or crosslinked structure). In particular, if the crosslinking agent (B) is a tolylene diisocyanate-based compound and/or an adduct thereof with a polyhydric alcohol compound, the durability can be improved even when the adhesive layer is applied to a polarizing plate, for example.

The content of the crosslinking agent (b) is usually 0.01 to 15 parts by weight, preferably 0.05 to 10 parts by weight, and more preferably 0.1 to 5 parts by weight, per 100 parts by weight of the (meth)acrylic resin (A).

The resin composition may further contain a silane compound (D).
Examples of the silane compound (D) include vinyltrimethoxysilane, vinyltriethoxysilane, vinyltris(2-methoxyethoxy)silane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropylethoxydimethylsilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-chloropropylmethyldimethoxysilane, 3-chloropropyltrimethoxysilane, 3-methacryloyloxypropyltrimethoxysilane, and 3-mercaptopropyltrimethoxysilane.
The silane compound (D) may be a silicone oligomer. Specific examples of the silicone oligomer, expressed in the form of a combination of monomers, are as follows:

Mercaptopropyl group-containing oligomers such as 3-mercaptopropyltrimethoxysilane-tetramethoxysilane oligomer, 3-mercaptopropyltriethoxysilane-tetramethoxysilane oligomer, 3-mercaptopropyltriethoxysilane-tetramethoxysilane oligomer, 3-mercaptopropyltriethoxysilane-tetraethoxysilane oligomer; mercaptomethyltrimethoxysilane-tetramethoxysilane oligomer, mercaptomethyltrimethoxysilane-tetraethoxysilane oligomer, mercaptomethyltrimethoxysilane-tetramethoxysilane oligomer, mercaptomethyl group-containing oligomers such as mercaptomethyltriethoxysilane-tetramethoxysilane oligomer, mercaptomethyltriethoxysilane-tetraethoxysilane oligomer, etc.; 3-glycidoxypropyltrimethoxysilane-tetramethoxysilane copolymer, 3-glycidoxypropyltrimethoxysilane-tetraethoxysilane copolymer, 3-glycidoxypropyltriethoxysilane-tetramethoxysilane copolymer, 3-glycidoxypropyltriethoxysilane-tetramethoxysilane copolymer, 3-glycidoxypropyltriethoxysilane-tetraethoxysilane copolymer, 3-glycidoxypropyltriethoxysilane-tetraethoxysilane copolymer, 3-glycidoxypropyl Copolymers containing 3-glycidoxypropyl groups, such as methyldimethoxysilane-tetramethoxysilane copolymer, 3-glycidoxypropylmethyldimethoxysilane-tetraethoxysilane copolymer, 3-glycidoxypropylmethyldiethoxysilane-tetramethoxysilane copolymer, and 3-glycidoxypropylmethyldiethoxysilane-tetraethoxysilane copolymer; 3-methacryloyloxypropyltrimethoxysilane-tetramethoxysilane oligomer, 3-methacryloyloxypropyltrimethoxysilane-tetramethoxysilane oligomer, Ethoxysilane oligomer, 3-methacryloyloxypropyl triethoxysilane-tetramethoxysilane oligomer, 3-methacryloyloxypropyl triethoxysilane-tetraethoxysilane oligomer, 3-methacryloyloxypropyl methyl dimethoxysilane-tetramethoxysilane oligomer, 3-methacryloyloxypropyl methyl dimethoxysilane-tetraethoxysilane oligomer, 3-methacryloyloxypropyl methyl diethoxysilane-tetramethoxysilane oligomer, 3-methacryloyloxypropyl methyl diethoxysilane-tetramethoxysilane oligomer, methacryloyloxypropyl group-containing oligomers such as 3-acryloyloxypropyltrimethoxysilane-tetramethoxysilane oligomer, 3-acryloyloxypropyltrimethoxysilane-tetraethoxysilane oligomer, 3-acryloyloxypropyltriethoxysilane-tetramethoxysilane oligomer, 3-acryloyloxypropyltriethoxysilane-tetramethoxysilane oligomer, 3-acryloyloxypropyltriethoxysilane-tetraethoxysilane oligomer, 3-acryloyloxypropylmethyldimethoxysilane acryloyloxypropyl group-containing oligomers such as acryloyloxypropyl methyldimethoxysilane-tetramethoxysilane oligomer, 3-acryloyloxypropyl methyldiethoxysilane-tetramethoxysilane oligomer, 3-acryloyloxypropyl methyldiethoxysilane-tetraethoxysilane oligomer, and 3-acryloyloxypropyl methyldiethoxysilane-tetraethoxysilane oligomer; vinyltrimethoxysilane-tetramethoxysilane oligomer, vinyltrimethoxysilane-tetraethoxysilane oligomer, vinyltriethoxysilane-tetraethoxysilane oligomer, and vinyl group-containing oligomers such as vinyltriethoxysilane-tetraethoxysilane oligomer, vinylmethyldimethoxysilane-tetramethoxysilane oligomer, vinylmethyldimethoxysilane-tetraethoxysilane oligomer, vinylmethyldiethoxysilane-tetramethoxysilane oligomer, and vinylmethyldiethoxysilane-tetraethoxysilane oligomer; 3-aminopropyltrimethoxysilane-tetramethoxysilane copolymer, 3-aminopropyltrimethoxysilane-tetraethoxysilane copolymer, amino group-containing copolymers such as silane copolymer, 3-aminopropyltriethoxysilane-tetramethoxysilane copolymer, 3-aminopropyltriethoxysilane-tetraethoxysilane copolymer, 3-aminopropylmethyldimethoxysilane-tetramethoxysilane copolymer, 3-aminopropylmethyldimethoxysilane-tetraethoxysilane copolymer, 3-aminopropylmethyldiethoxysilane-tetramethoxysilane copolymer, and 3-aminopropylmethyldiethoxysilane-tetraethoxysilane copolymer.

The silane compound (D) may be a silane compound represented by the following formula (d1). When the adhesive composition contains a silane compound represented by the following formula (d1), the adhesiveness (or bonding property) can be further improved, so that an adhesive layer with good peel resistance can be formed. In particular, even when the adhesive layer is applied (or laminated) to a transparent electrode or glass in a high-temperature environment, the adhesiveness (or bonding property) can be maintained and high durability can be exhibited.

（式中、Ｂは、炭素数１～２０のアルカンジイル基又は炭素数３～２０の二価の脂環式炭化水素基を示し、前記アルカンジイル基及び前記脂環式炭化水素基を構成する－ＣＨ_２－は、－Ｏ－又は－ＣＯ－に置換されてもよく、Ｒ^ｄ７は炭素数１～５のアルキル基を示し、Ｒ^ｄ８、Ｒ^ｄ９、Ｒ^ｄ10、Ｒ^ｄ11及びＲ^ｄ12はそれぞれ独立して、炭素数１～５のアルキル基又は炭素数１～５のアルコキシ基を示す）

(In the formula, B represents an alkanediyl group having 1 to 20 carbon atoms or a divalent alicyclic hydrocarbon group having 3 to 20 carbon atoms, -CH ₂ - constituting the alkanediyl group and the alicyclic hydrocarbon group may be substituted with -O- or -CO-, R ^d7 represents an alkyl group having 1 to 5 carbon atoms, and R ^d8 , R ^d9 , R ^d10 , R ^d11 and R ^d12 each independently represent an alkyl group having 1 to 5 carbon atoms or an alkoxy group having 1 to 5 carbon atoms.)

In formula (d1), B represents an alkanediyl group having 1 to 20 carbon atoms, such as a methylene group, an ethylene group, a trimethylene group, a tetramethylene group, a hexamethylene group, a heptamethylene group, or an octamethylene group; a divalent alicyclic hydrocarbon group having 3 to 20 carbon atoms, such as a cyclobutylene group (for example, a 1,2-cyclobutylene group), a cyclopentylene group (for example, a 1,2-cyclopentylene group), a cyclohexylene group (for example, a 1,2-cyclohexylene group), or a cyclooctylene group (for example, a 1,2-cyclooctylene group), or these alkanediyl groups and groups in which -CH2- constituting the alicyclic hydrocarbon group is replaced with -O- or -CO-. Preferred B is an alkanediyl group having 1 to 10 carbon atoms. R ^d7 represents an alkyl group having 1 to 5 carbon atoms, such as a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a s-butyl group, a t-butyl group, or a pentyl group, and R ^d8 , R ^d9 , R ^d10 , R ^d11 , and R ^d12 each independently represent an alkyl group having 1 to 5 carbon atoms, such as the exemplified R ^d7 , or an alkoxy group having 1 to 5 carbon atoms, such as a methoxy group, an ethoxy group, a propoxy group, an i-propoxy group, a butoxy group, a s-butoxy group, or a t-butoxy group. Preferably, R ^d8 , R ^d9 , R ^d10 , R ^d11 , and R ^d12 each independently represent an alkoxy group having 1 to 5 carbon atoms. These silane compounds (D) can be used alone or in combination of two or more.

Specific examples of the silane compound represented by the formula (d1) include bis(triC1) compounds such as (trimethoxysilyl)methane, 1,2-bis(trimethoxysilyl)ethane, 1,2-bis(triethoxysilyl)ethane, 1,3-bis(trimethoxysilyl)propane, 1,3-bis(triethoxysilyl)propane, 1,4-bis(trimethoxysilyl)butane, 1,4-bis(triethoxysilyl)butane, 1,5-bis(trimethoxysilyl)pentane, 1,5-bis(triethoxysilyl)pentane, 1,6-bis(trimethoxysilyl)hexane, 1,6-bis(triethoxysilyl)hexane, 1,6-bis(tripropoxysilyl)hexane, 1,8-bis(trimethoxysilyl)octane, 1,8-bis(triethoxysilyl)octane, and 1,8-bis(tripropoxysilyl)octane. bis(diC1-5 alkoxy C1-5 alkylsilyl) C1-10 alkanes such as bis(dimethoxymethylsilyl)methane, 1,2-bis(dimethoxymethylsilyl)ethane, 1,2-bis(dimethoxyethylsilyl)ethane, 1,4-bis(dimethoxymethylsilyl)butane, 1,4-bis(dimethoxyethylsilyl)butane, 1,6-bis(dimethoxymethylsilyl)hexane, 1,6-bis(dimethoxyethylsilyl)hexane, 1,8-bis(dimethoxymethylsilyl)octane, and 1,8-bis(dimethoxyethylsilyl)octane; and bis(mono C1-5 alkoxy-di C1-5 alkylsilyl) C1-10 alkanes such as 1,6-bis(methoxydimethylsilyl)hexane and 1,8-bis(methoxydimethylsilyl)octane. Of these, bis(triC1-3 alkoxysilyl)C1-10 alkanes such as 1,2-bis(trimethoxysilyl)ethane, 1,3-bis(trimethoxysilyl)propane, 1,4-bis(trimethoxysilyl)butane, 1,5-bis(trimethoxysilyl)pentane, 1,6-bis(trimethoxysilyl)hexane, and 1,8-bis(trimethoxysilyl)octane are preferred, with 1,6-bis(trimethoxysilyl)hexane and 1,8-bis(trimethoxysilyl)octane being particularly preferred.

The content of the silane compound (D) is usually 0.01 to 10 parts by weight, preferably 0.03 to 5 parts by weight, more preferably 0.05 to 2 parts by weight, and even more preferably 0.1 to 1 part by weight, based on 100 parts by weight of the (meth)acrylic resin (A). If it is equal to or less than the upper limit, it is advantageous for suppressing bleeding out of the silane compound (D) from the adhesive layer, and if it is equal to or more than the lower limit, it is easier to improve the adhesion (or adhesiveness) between the adhesive layer and a metal layer, a glass substrate, etc., and is advantageous for improving peel resistance, etc.

The pressure-sensitive adhesive composition may further contain an antistatic agent.
Examples of the antistatic agent include surfactants, siloxane compounds, conductive polymers, ionic compounds, etc., and ionic compounds are preferred. Examples of the ionic compound include conventional ones. Examples of the cationic component constituting the ionic compound include organic cations and inorganic cations. Examples of the organic cation include pyridinium cation, pyrrolidinium cation, piperidinium cation, imidazolium cation, ammonium cation, sulfonium cation, phosphonium cation, etc. Examples of the inorganic cation include alkali metal cations such as lithium cation, potassium cation, sodium cation, and cesium cation, and alkaline earth metal cations such as magnesium cation and calcium cation. In particular, from the viewpoint of compatibility with (meth)acrylic resins, pyridinium cation, imidazolium cation, pyrrolidinium cation, lithium cation, and potassium cation are preferred. Examples of the anionic component constituting the ionic compound may be either inorganic anion or organic anion, but from the viewpoint of antistatic performance, an anionic component containing a fluorine atom is preferred. Examples of anion components containing fluorine atoms include hexafluorophosphate anion (PF ₆ -), bis(trifluoromethanesulfonyl)imide anion [(CF ₃ SO ₂ ) ₂ N-], bis(fluorosulfonyl)imide anion [(FSO ₂ ) ₂ N-], and tetra(pentafluorophenyl)borate anion [(C ₆ F ₅ ) ₄ B-]. These ionic compounds can be used alone or in combination of two or more. In particular, bis(trifluoromethanesulfonyl)imide anion [(CF ₃ SO ₂ ) ₂ N-], bis(fluorosulfonyl)imide anion [(FSO ₂ ) ₂ N-], and tetra(pentafluorophenyl)borate anion [(C ₆ F ₅ ) ₄ B-] are preferred.
In terms of the stability over time of the antistatic performance of the pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition, an ionic compound that is solid at room temperature is preferred.

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, per 100 parts by mass of the (meth)acrylic resin (A).

The adhesive composition may contain one or more additives such as a solvent, a crosslinking catalyst, a tackifier, a plasticizer, a softener, a pigment, an anti-rust agent, an inorganic filler, or light-scattering fine particles.

An example of the pressure-sensitive adhesive layer-attached optical film according to the present invention is shown in FIG.
As shown in Fig. 1, the pressure-sensitive adhesive layer-attached optical film of the present invention, which has a pressure-sensitive adhesive layer 2 on at least one side of the optical film 1, may have a separate film (release film) 3 laminated on the side opposite to the side where the optical film and the pressure-sensitive adhesive layer are attached. This separate film 3 is usually peeled off and removed when the pressure-sensitive adhesive layer-attached optical film is used (for example, when it is laminated on a liquid crystal cell, a retardation film, etc.). The separate film may be, for example, a film made of various resins such as polyethylene terephthalate, polybutylene terephthalate, polycarbonate, polyarene, etc., which has been subjected to a release treatment such as silicone treatment on the side on which the pressure-sensitive adhesive layer is formed.

2 to 5 show an example of the layer structure of an optical laminate including the optical film according to the present invention.
The optical laminate 10A shown in FIG. 2 is an optical laminate including a protective film 4, an adhesive layer 5, a polarizing film 6, an adhesive layer 5, the optical film 1 of the present invention, and a pressure-sensitive adhesive layer 7.
The optical laminate 10B shown in FIG. 3 is an optical laminate including the optical film 1 of the present invention, an adhesive layer 5, a polarizing film 6, an adhesive layer 5, a protective film 4, and a pressure-sensitive adhesive layer 7.
The optical film 10C shown in FIG. 4 and the optical laminate 10D shown in FIG. 5 are optical laminates including a protective film 4, an adhesive layer 5, a polarizing film 6, an adhesive layer 5, the optical film 1 of the present invention, a pressure-sensitive adhesive layer 7, an optical film 40, a pressure-sensitive adhesive layer 7a, and a light-emitting element 30 (liquid crystal cell, OLED cell).

As shown in Figures 2 to 5, an optical film such as a retardation film, a polarizing film, a window film, a light collecting film, or a brightness enhancing film may be laminated on the adhesive layer surface of the adhesive layer-attached optical film of the present invention.

A retardation film is an optical film that exhibits optical anisotropy, and examples of such films include stretched films obtained by stretching polymer films made of polyvinyl alcohol, polycarbonate, polyester, polyarylate, polyimide, polyolefin, polycycloolefin, polystyrene, polysulfone, polyethersulfone, polyvinylidene fluoride/polymethyl methacrylate, acetyl cellulose, saponified ethylene-vinyl acetate copolymer, polyvinyl chloride, etc., by about 1.01 to 6 times. Among these, polymer films obtained by uniaxially or biaxially stretching polycarbonate films or cycloolefin resin films are preferred. In this specification, retardation films include zero retardation films, and also include films called uniaxial retardation films, low photoelasticity retardation films, wide viewing angle retardation films, etc.

Films that exhibit optical anisotropy through the application and orientation of liquid crystal compounds, or films that exhibit optical anisotropy through the application of inorganic layered compounds, include films known as temperature-compensated retardation films, such as "NH film" (product name: film with tilted alignment of rod-shaped liquid crystals) sold by JX Nippon Oil & Energy Corporation, "WV film" (product name: film with tilted alignment of discotic liquid crystals) sold by Fujifilm Corporation, "VAC film" (product name: fully biaxially oriented film) sold by Sumitomo Chemical Co., Ltd., and "new VAC film" (product name: biaxially oriented film) sold by Sumitomo Chemical Co., Ltd.

The zero retardation film is an optically isotropic film in which the front retardation R _e and the thickness retardation R _th are both −15 to 15 nm. Examples of the zero retardation film include resin films made of cellulose resins, polyolefin resins (chain polyolefin resins, polycycloolefin resins, etc.), or polyethylene terephthalate resins. Cellulose resins or polyolefin resins are preferred because they are easy to control the retardation value and are easily available. The zero retardation film can also be used as a protective film. Examples of the zero retardation film include “Z-TAC” (trade name) sold by Fujifilm Corporation, “Zerotack (registered trademark)” sold by Konica Minolta Opto Co., Ltd., and “ZF-14” (trade name) sold by Zeon Corporation.

In the present invention, the retardation film is preferably a retardation film obtained by curing a polymerizable liquid crystal compound.

Films that exhibit optical anisotropy by coating and orienting liquid crystal compounds include: first form: retardation film in which rod-shaped liquid crystal compounds are oriented horizontally relative to the supporting substrate; second form: retardation film in which rod-shaped liquid crystal compounds are oriented vertically relative to the supporting substrate; third form: retardation film in which the orientation direction of rod-shaped liquid crystal compounds changes in a spiral manner in the plane; fourth form: retardation film in which discotic liquid crystal compounds are oriented at an angle; and fifth form: biaxial retardation film in which discotic liquid crystal compounds are oriented vertically relative to the supporting substrate.

For example, the first, second, and fifth forms are preferably used as optical films for organic electroluminescence displays. Alternatively, these may be laminated and used.

When the retardation film is a layer made of a polymer in an oriented state of a polymerizable liquid crystal compound (hereinafter, sometimes referred to as an "optically anisotropic layer"), the retardation film preferably has reverse wavelength dispersion. Reverse wavelength dispersion is an optical property in which the liquid crystal alignment in-plane retardation value at a short wavelength is smaller than the liquid crystal alignment in-plane retardation value at a long wavelength, and preferably, the retardation film satisfies the following formulas (7) and (8). Note that Re(λ) represents the in-plane retardation value for light with a wavelength of λ nm.
Re(450)/Re(550)≦1 (7)
1≦Re(630)/Re(550) (8)
In the optical film of the present invention, when the retardation film is in the first form and has reverse wavelength dispersion, coloring during black display on a display device is reduced, which is preferable, and in the formula (7), it is more preferable that 0.82≦Re(450)/Re(550)≦0.93. It is further preferable that 120≦Re(550)≦150.

When the retardation film is a film having an optically anisotropic layer, examples of the polymerizable liquid crystal compound include compounds having a polymerizable group among the compounds described in "3.8.6 Network (fully cross-linked type)" and "6.5.1 Liquid crystal material b. Polymerizable nematic liquid crystal material" in Liquid Crystal Handbook (edited by Liquid Crystal Handbook Editorial Committee, published by Maruzen Co., Ltd. on October 30, 2000), as well as the polymerizable liquid crystal compounds described in JP-A-2010-31223, JP-A-2010-270108, JP-A-2011-6360, JP-A-2011-207765, JP-A-2011-162678, JP-A-2016-81035, WO 2017/043438, and JP-T-2011-207765.

A method for producing a retardation film from a polymer in an oriented state of a polymerizable liquid crystal compound is, for example, the method described in JP 2010-31223 A.

In the case of the second embodiment, the front retardation value Re (550) may be adjusted to a range of 0 to 10 nm, preferably 0 to 5 nm, and the thickness retardation value R _th may be adjusted to a range of -10 to -300 nm, preferably -20 to -200 nm. The thickness retardation value R _th , which means the refractive index anisotropy in the thickness direction, can be calculated from the retardation value R ₅₀ measured by tilting the in-plane fast axis as the tilt axis at 50 degrees and the in-plane retardation value R _0. That is, the thickness retardation value R _th can be calculated by determining n x , n y and n z from the in-plane retardation value R ₀ , the retardation value R ₅₀ measured by tilting the in-plane fast axis as the tilt axis at 50 degrees, the _thickness d of the retardation film, and the average refractive _index n ₀ of the retardation film according to the following _formulas (10) to (12), and substituting these into formula (9).

R _th = [(n _x + _ny )/2- _nz ] x d (9)
R ₀ = (n _x - _ny ) x d (10)
R ₅₀ = (n _x - _ny ') x d/cos(φ) (11)
(n _x + _ny + _nz )/3=n ₀ (12)
Where:
φ=sin ⁻¹ [sin (40°)/n ₀ ]
_ny ' = _ny × _nz / [ _ny ² × sin ² (φ) + _nz ² × cos ² (φ)] ^1/2

The retardation film may be a multi-layer film having two or more layers. For example, a retardation film may have a protective film laminated on one or both sides thereof, or two or more retardation films may be laminated together via a pressure-sensitive adhesive or adhesive.

When the optical film 40 is a multilayer film in which two or more retardation films are laminated, the optical laminate including the optical film of the present invention may have a configuration including an optical film 40 in which a 1/4 wavelength retardation layer 50 that imparts a phase difference of 1/4 wavelength to transmitted light and a 1/2 wavelength retardation layer 70 that imparts a phase difference of 1/2 wavelength to transmitted light are laminated via an adhesive or pressure-sensitive adhesive 60, as shown in FIG. 4. In addition, as shown in FIG. 5, a configuration including an optical film 40 in which a 1/4 wavelength retardation layer 50a and a positive C layer 80 are laminated via an adhesive layer or pressure-sensitive adhesive layer may also be used.

The 1/4 wavelength retardation layer 50 in FIG. 4 that imparts a phase difference of 1/4 wavelength, and the 1/2 wavelength retardation layer 70 that imparts a phase difference of 1/2 wavelength to transmitted light may be an optical film of the first form or an optical film of the fifth form. In the case of the configuration in FIG. 4, it is more preferable that at least one of them is the fifth form.

In the configuration of FIG. 5, the quarter-wave retardation layer 50a is preferably an optical film of the first form described above, and more preferably satisfies formulas (7) and (8).

A polarizing film is a film that has the property of absorbing linearly polarized light with a vibration plane parallel to its absorption axis and transmitting linearly polarized light with a vibration plane perpendicular to the absorption axis (parallel to the transmission axis). For example, a film in which a dichroic dye is adsorbed and oriented on a polyvinyl alcohol-based resin film can be used. Examples of dichroic dyes include iodine and dichroic organic dyes.

Typically, a film made from polyvinyl alcohol resin is used as the base film for the polarizing film. The polyvinyl alcohol resin can be made into a film by a known method. The thickness of the base film is typically 1 to 150 μm, and is preferably 10 μm or more, taking into consideration the ease of stretching.

Polarizing films are produced, for example, by subjecting raw film to the following steps: uniaxial stretching; dyeing the film with a dichroic dye to allow the dichroic dye to be adsorbed; treating the film with an aqueous boric acid solution; washing the film with water; and finally drying. The thickness of the polarizing film is usually 1 to 30 μm, and from the viewpoint of thinning, it is preferably 20 μm or less, more preferably 15 μm or less, and particularly preferably 10 μm or less.

A polarizing film obtained by adsorbing and orienting a dichroic dye on a polyvinyl alcohol-based resin film can be obtained by a method (referred to as method (1)) in which a single film of a polyvinyl alcohol-based resin film is used as the raw film and the film is subjected to uniaxial stretching and dyeing with a dichroic dye, or by a method (referred to as method (2)) in which a coating liquid (such as an aqueous solution) containing a polyvinyl alcohol-based resin is applied to a substrate film and dried to obtain a substrate film having a polyvinyl alcohol-based resin layer, which is then uniaxially stretched for each substrate film, the stretched polyvinyl alcohol-based resin layer is subjected to dyeing with a dichroic dye, and then the substrate film is peeled off. As the substrate film, a film made of a thermoplastic resin can be used, and preferably a film made of a polyester-based resin such as polyethylene terephthalate, a polycarbonate-based resin, a cellulose-based resin such as triacetyl cellulose, a cyclic polyolefin-based resin such as norbornene-based resin, a polystyrene-based resin, or the like. By using the above method (2), it is easy to prepare a thin polarizing film, and even a polarizer 2 having a thickness of, for example, 7 μm or less can be easily prepared.

At least one surface of the polarizing film is preferably provided with a protective film via an adhesive.
As the adhesive, a known adhesive is used, and it may be a water-based adhesive or an active energy ray curable adhesive.

Examples of water-based adhesives include conventional water-based adhesives (e.g., adhesives made of an aqueous polyvinyl alcohol resin solution, water-based two-liquid urethane emulsion adhesives, crosslinking agents such as aldehyde compounds, epoxy compounds, melamine compounds, methylol compounds, isocyanate compounds, amine compounds, polyvalent metal salts, etc.). Of these, water-based adhesives made of an aqueous polyvinyl alcohol resin solution can be preferably used. When using a water-based adhesive, it is preferable to carry out a drying process to remove water contained in the water-based adhesive after laminating the polarizing film and the protective film. After the drying process, a curing process may be carried out in which the product is cured at a temperature of, for example, about 20 to 45°C.

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

When using an active energy ray-curable adhesive, after laminating the polarizing film and the protective film, a drying process is carried out as necessary, and then a curing process is carried out in which the active energy ray-curable adhesive is cured by irradiating it with active energy rays. There are no particular limitations on the source of the active energy rays, but ultraviolet light with an emission distribution of wavelengths of 400 nm or less is preferred.

Methods for bonding a polarizing film and a 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, or plasma treatment. When resin films are bonded to both sides of the polarizing film, the adhesives used to bond these resin films may be the same or different types of adhesives.

A preferred configuration of the polarizing plate is a polarizing plate in which a protective film is laminated on at least one surface of the polarizing film via an adhesive layer. When the protective film is laminated on only one surface of the polarizing film, it is more preferable that the protective film is laminated on the viewing side. The protective film laminated on the viewing side is preferably a protective film made of a triacetyl cellulose resin or a cycloolefin resin. The protective film may be an unstretched film, or may be stretched in any direction and have a phase difference. A surface treatment layer such as a hard coat layer or an anti-glare layer may be provided on the surface of the protective film laminated on the viewing side.
When the protective film is laminated on both sides of the polarizing film, the protective film on the panel side (opposite the viewing side) is preferably a protective film or a retardation film made of a triacetyl cellulose resin, a cycloolefin resin, or an acrylic resin. The retardation film may be a zero retardation film described later.
Between the polarizing plate and the panel, other layers or films may be laminated. When used as a circular polarizing plate for an organic EL display, it is preferable that a retardation layer having a 1/4 wavelength retardation layer and a 1/2 wavelength retardation layer, and a 1/4 wavelength layer having reverse wavelength dispersion described later are laminated. From the viewpoint of thinning, it is preferable that the retardation layer is a liquid crystal retardation film.

Light-collecting films are used for purposes such as controlling the light path, and can be prism array sheets, lens array sheets, dot-attached sheets, etc.

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

The window film refers to the front panel of a flexible display device such as a flexible display, and is generally placed on the outermost surface of the display device. An example of the window film is a resin film made of polyimide resin. The window film may be a hybrid film of an organic material and an inorganic material, such as a resin film containing polyimide and silica. The window film may also have a hard coat layer on its surface to provide surface hardness, antifouling properties, and fingerprint resistance. For example, the film described in JP 2017-94488 A may be used.

The optical film of the present invention may be used as a protective film for a polarizing plate.
As described above, the polarizing plate has a protective film laminated on one or both sides of the polarizing film via an adhesive layer. In a polarizing plate having a protective film laminated on both sides of a polarizer, the optical film of the present invention may be used as the protective film on one side of the polarizer, or the optical film of the present invention may be used as the protective film on both sides. In addition, a polarizing plate using the optical film of the present invention as a protective film of the polarizing plate may be laminated with another optical film via an adhesive layer or a pressure-sensitive adhesive layer. Figures 2 and 3 show an example in which the optical film of the present invention is used as a protective film of a polarizing plate.

The adhesive layer 5 is a layer formed from a known adhesive. The known adhesive may be a water-based adhesive or an active energy ray curable adhesive. The pressure-sensitive adhesive layer 6 may be a layer formed from the above-mentioned pressure-sensitive adhesive or a layer formed from another known pressure-sensitive adhesive.

The protective film 4 may be a known thermoplastic resin film. The protective film 4 may be the optical film of the present invention.

The optical film of the present invention can be suitably used in liquid crystal display devices.

The present invention will be explained in more detail below with reference to examples and comparative examples, but the present invention is not limited to these examples. In the examples, percentages and parts indicating the content or amount used are based on mass unless otherwise specified.

ジムロート冷却管、温度計を設置した２００ｍＬ－四ツ口フラスコ内を窒素雰囲気とし、特許文献（特開２０１４－１９４５０８）を参考に合成した式（ａａ）で表される化合物１０ｇ、無水酢酸（和光純薬工業株式会社製）３．６ｇ、シアノ酢酸２－エチルヘキシル（東京化成工業株式会社製）６．９ｇ、およびアセトニトリル（和光純薬工業株式会社製）６０ｇを仕込み、マグネチックスターラーで撹拌した。内温２５℃にてＤＩＰＥＡ（東京化成工業株式会社製）４．５ｇを滴下漏斗から１時間かけて滴下し、滴下終了後に内温２５℃にてさらに２時間保温した。反応終了後、減圧エバポレーターを用いてアセトニトリルを除去し、カラムクロマトグラフィー（シリカゲル）に供して精製し、式（ａａ１）で表される光選択吸収性化合物（１）を含む流出液を、減圧エバポレーターを用いて溶媒を除去し、黄色結晶を得た。該結晶を６０℃減圧乾燥することにより、黄色粉末として光選択吸収性化合物（１）を４．６ｇ得た。収率は５０％であった <Synthesis of light selective absorbing compound>
[Synthesis Example 1] Synthesis of light selective absorption compound (1)

A 200 mL four-neck flask equipped with a Dimroth condenser and a thermometer was placed in a nitrogen atmosphere, and 10 g of a compound represented by formula (aa) synthesized with reference to a patent document (JP 2014-194508), 3.6 g of acetic anhydride (manufactured by Wako Pure Chemical Industries, Ltd.), 6.9 g of 2-ethylhexyl cyanoacetate (manufactured by Tokyo Chemical Industry Co., Ltd.), and 60 g of acetonitrile (manufactured by Wako Pure Chemical Industries, Ltd.) were charged and stirred with a magnetic stirrer. At an internal temperature of 25°C, 4.5 g of DIPEA (manufactured by Tokyo Chemical Industry Co., Ltd.) was dropped from the dropping funnel over 1 hour, and after the end of the dropwise addition, the internal temperature was kept at 25°C for another 2 hours. After the reaction was completed, acetonitrile was removed using a reduced pressure evaporator, and the mixture was purified by column chromatography (silica gel), and the effluent containing the light-selective absorbing compound (1) represented by formula (aa1) was subjected to reduced pressure evaporator to remove the solvent, and yellow crystals were obtained. The crystals were dried under reduced pressure at 60° C. to obtain 4.6 g of light selective absorbing compound (1) as a yellow powder. The yield was 50%.

When ¹ H-NMR analysis was carried out, the following peaks were observed, confirming that the light selective absorbing compound (1) was produced.
¹ H-NMR (CDCl3) δ: 0.87-0.94 (m, 6H), 1.32-1.67 (m, 8H), 1.59-1.66 (m, 2H), 2.0 9 (quin, 2H), 3.00 (m, 5H), 3.64 (t, 2H), 4.10 (dd, 2H), 5.52 (d, 2H), 7.87 (d, 2H)

<Measurement of Gram Absorption Coefficient ε>
In order to measure the gram absorption coefficient of the obtained light-selective absorbing compound (1), the light-selective absorbing compound (1) was dissolved in 2-butanone. The obtained solution (concentration: 0.007 g/L) was placed in a 1 cm quartz cell, and the quartz cell was set in a spectrophotometer UV-2450 (manufactured by Shimadzu Corporation), and the absorbance was measured in the wavelength range of 300 to 800 nm in 1 nm steps by the double beam method. The gram absorption coefficient for each wavelength was calculated using the following formula from the obtained absorbance value, the concentration of the light-absorbing compound in the solution, and the optical path length of the quartz cell.
ε(λ)=A(λ)/CL
(wherein ε(λ) represents the gram absorption coefficient L/(g cm) of the compound at a wavelength of λ nm, A(λ) represents the absorbance at a wavelength of λ nm, C represents the concentration g/L, and L represents the optical path length cm of the quartz cell.)
The gram absorbance coefficient of the light selective absorbing compound (1) was ε(405) of 47 L/(g cm), ε(440) of 0.1 L/(g cm) or less, and ε(405)/ε(440) of 80 or more.

ジムロート冷却管、温度計を設置した２００ｍＬ－四ツ口フラスコ内に、窒素雰囲気において、特開２０１４－１９４５０８を参考に合成した式（ａａ）で表される化合物１０ｇ、無水酢酸（和光純薬工業株式会社製）３．６ｇ、シアノ酢酸２－ブチルオクチル（東京化成工業株式会社製）１０ｇ、及びアセトニトリル（和光純薬工業株式会社製）６０ｇを仕込み、マグネチックスターラーで撹拌した。内温２５℃にてＤＩＰＥＡ（東京化成工業株式会社製）４．５ｇを、得られた混合物に１時間かけて滴下した後、内温２５℃にてさらに２時間保温した。その後、減圧エバポレーターを用いてアセトニトリルを除去し、カラムクロマトグラフィー（シリカゲル）に供して精製し、式（ａａ２）で表される化合物を含む流出液を、減圧エバポレーターを用いて溶媒を除去し、黄色結晶を得た。該結晶を６０℃減圧乾燥することにより、黄色粉末として式（ａａ２）で表される化合物（光選択吸収化合物（２））を４．６ｇ得た。収率は５６％であった。
上記と同じ方法でグラム吸光度係数を求めると、式（ａａ４）で表される化合物のε（４０５）の値は４５Ｌ／（ｇ・ｃｍ）であり、ε（４２０）の値は２．１Ｌ／（ｇ・ｃｍ）であった。 [Synthesis Example 2] Synthesis of light selective absorption compound (1)

In a 200 mL-four-neck flask equipped with a Dimroth condenser and a thermometer, 10 g of the compound represented by formula (aa) synthesized with reference to JP 2014-194508, 3.6 g of acetic anhydride (manufactured by Wako Pure Chemical Industries, Ltd.), 10 g of 2-butyloctyl cyanoacetate (manufactured by Tokyo Chemical Industry Co., Ltd.), and 60 g of acetonitrile (manufactured by Wako Pure Chemical Industries, Ltd.) were charged in a nitrogen atmosphere and stirred with a magnetic stirrer. At an internal temperature of 25°C, 4.5 g of DIPEA (manufactured by Tokyo Chemical Industry Co., Ltd.) was added dropwise to the resulting mixture over 1 hour, and the mixture was then kept at an internal temperature of 25°C for another 2 hours. Thereafter, acetonitrile was removed using a reduced pressure evaporator, and the mixture was purified by column chromatography (silica gel), and the solvent was removed from the effluent containing the compound represented by formula (aa2) using a reduced pressure evaporator to obtain yellow crystals. The crystals were dried under reduced pressure at 60° C. to obtain 4.6 g of a compound represented by formula (aa2) (light selective absorption compound (2)) as a yellow powder. The yield was 56%.
When the gram absorbance coefficient was determined in the same manner as above, the ε(405) value of the compound represented by formula (aa4) was 45 L/(g cm), and the ε(420) value was 2.1 L/(g cm).

<Preparation of Optical Film>
Example 1 Preparation of Optical Film (1) A cellulose acylate solution (solid concentration: 10% by mass) consisting of cellulose triacetate (acetyl substitution degree: 2.87; Fujifilm Wako Pure Chemical Industries, Ltd., product name "Cellulose triacetate"), light selective absorbing compound (1) (3 parts by mass per 100 parts by mass of cellulose triacetate), and a solvent (a mixture of methylene chloride and ethanol, mass ratio 87:13) was placed in a mixing tank and stirred to dissolve each component.
The obtained solution was uniformly cast onto a glass support using an applicator, dried in an oven at 40° C. for 10 minutes, and then further dried in an oven at 80° C. for 10 minutes. After drying, the optical film (1) was peeled off from the glass support to obtain an optical film (1) having light selective absorption ability. The film thickness of the optical film (1) after drying was 30 μm.

<Measurement of storage modulus>
The obtained optical film (1) was cut into a size of 5 mm x 30 mm. The cut light selective absorption layer (A-1) was gripped with a gripping distance of 2 cm using a dynamic viscoelasticity measuring device "DVA-220" manufactured by IT Measurement and Control Co., Ltd. so that the long side of the layer was in the tensile direction, and the storage modulus E' at temperatures of 23°C to 200°C was determined by setting the tensile and contraction frequency to 10 Hz and the heating rate to 10°C/min. The storage modulus E' at 23°C was 4100 MPa.

Example 2 Preparation of Optical Film (2) A cellulose acylate solution (solid concentration: 5% by mass) consisting of cellulose triacetate (acetyl substitution degree: 2.87; Fujifilm Wako Pure Chemical Industries, Ltd., product name "Cellulose triacetate"), light selective absorbing compound (2) (2 parts by mass per 100 parts by mass of cellulose triacetate), and a solvent (a mixture of methylene chloride and ethanol, mass ratio 90:10) was placed in a mixing tank and stirred to dissolve each component.
The obtained solution was uniformly cast onto a glass support using an applicator, dried in an oven at 40° C. for 10 minutes, and then further dried in an oven at 80° C. for 10 minutes. After drying, the optical film (2) was peeled off from the glass support to obtain an optical film (2) having selective light absorption ability. The film thickness of the optical film (2) after drying was 20 μm. The storage modulus of the obtained optical film (2) was measured in the same manner as above, and the storage modulus E' at 23° C. was 3800 MPa.

<Synthesis of (meth)acrylic resin>
[Synthesis Example 3]
A reaction vessel equipped with a cooling tube, a nitrogen inlet tube, a thermometer and a stirrer was charged with 81.8 parts of ethyl acetate as a solvent, 70.4 parts of butyl acrylate, 20.0 parts of methyl acrylate as monomers, and 8.0 parts of 2-phenoxyethyl acrylate, 1.0 parts of 2-hydroxyethyl acrylate and 0.6 parts of acrylic acid. The air in the reaction vessel was replaced with nitrogen gas, and the internal temperature was then adjusted to 60°C. Then, a solution in which 0.12 parts of azobisisobutyronitrile was dissolved in 10 parts of ethyl acetate was added. After maintaining the temperature at the same temperature for 1 hour, ethyl acetate was continuously added to the reaction vessel at an addition rate of 17.3 parts/Hr while maintaining the internal temperature at 54-56°C so that the polymer concentration was approximately 35%. The internal temperature was maintained at 54-56°C until 12 hours had elapsed since the start of the addition of ethyl acetate, and then ethyl acetate was added to adjust the polymer concentration to 20%, to obtain an ethyl acetate solution (1) of a (meth)acrylic resin. The (meth)acrylic resin had a weight average molecular weight Mw of 1,390,000, and a ratio Mw/Mn of the weight average molecular weight Mw to the number average molecular weight Mn of 5.32.

The weight-average molecular weight and number-average molecular weight were measured using a GPC apparatus with four "TSK gel XL (Tosoh Corporation)" columns and one "Shodex GPC KF-802 (Showa Denko K.K.)" columns connected in series, a total of five columns, and tetrahydrofuran as the eluent under conditions of a sample concentration of 5 mg/mL, a sample introduction amount of 100 μL, a temperature of 40°C, and a flow rate of 1 mL/min, and were calculated in terms of standard polystyrene.

<Synthesis of (meth)acrylic resin pressure-sensitive adhesive composition (1)>
[Production Example 1]
The ethyl acetate solution (1) of the (meth)acrylic resin obtained above (resin concentration: 20%) was mixed with 0.4 parts of a crosslinking agent (Coronate L, solid content 75%: manufactured by Tosoh Corporation) and 0.4 parts of a silane compound (KBM-403 manufactured by Shin-Etsu Chemical Co., Ltd.) per 100 parts of solid content of the solution, and ethyl acetate was further added to give a solid content concentration of 14%, thereby obtaining a pressure-sensitive adhesive composition (1). Note that the blending amount of the crosslinking agent is the number of parts by mass as an active ingredient.

The crosslinking agent and silane compound used in Production Example 1 are as follows.
Crosslinking agent: an ethyl acetate solution (solid content concentration 75%) of a trimethylolpropane adduct of tolylene diisocyanate, trade name "Coronate L" available from Tosoh Corporation.
Silane compound: 3-glycidoxypropyltrimethoxysilane, trade name "KBM403" obtained from Shin-Etsu Chemical Co., Ltd.

<Preparation of Adhesive Layer>
[Production Example 2]
The pressure-sensitive adhesive composition (1) prepared in Production Example 1 was applied to a release-treated surface of a separate film made of a release-treated polyethylene terephthalate film (product name "PLR-382190" available from Lintec Corporation) using an applicator so as to give a dry thickness of 20 μm, and then dried at 100° C. for 1 minute to prepare a pressure-sensitive adhesive layer (1).

<Synthesis of (meth)acrylic pressure-sensitive adhesive composition (2)>
[Production Example 3]
An ethyl acetate solution (1) (resin concentration: 20%) of the (meth)acrylic resin obtained in Synthesis Example 3 was mixed with 0.4 parts of a crosslinking agent (Coronate L, solid content 75%, manufactured by Tosoh), 0.4 parts of a silane compound (KBM-403, manufactured by Shin-Etsu Chemical Co., Ltd.), and 2 parts of the light selective absorbing compound (1) synthesized in Synthesis Example 1 relative to 100 parts of the solid content of the solution, and ethyl acetate was further added to give a solid content concentration of 14%, to obtain a pressure-sensitive adhesive composition (2). The blending amount of the crosslinking agent (Coronate L) is the number of parts by mass as an active ingredient.

<Preparation of Pressure-Sensitive Adhesive Layer (2)>
The pressure-sensitive adhesive composition (2) prepared above was applied to a release-treated surface of a separate film made of a release-treated polyethylene terephthalate film (product name "PLR-382190" available from Lintec Corporation) using an applicator so as to give a dried thickness of 20 μm, and the applied film was dried at 100° C. for 1 minute to prepare a pressure-sensitive adhesive layer (2).

<Synthesis of (meth)acrylic pressure-sensitive adhesive composition (3)>
[Production Example 4]
A pressure-sensitive adhesive composition (3) was obtained in the same manner as in Synthesis Example 6, except that the light-selective absorption compound was changed to the light-selective absorption compound (2).
The obtained pressure-sensitive adhesive composition (3) was applied to a release-treated surface of a separate film made of a release-treated polyethylene terephthalate film (product name "PLR-382190" available from Lintec Corporation) using an applicator so that the thickness after drying would be 20 μm, and the coating was dried at 100° C. for 1 minute to prepare a pressure-sensitive adhesive layer (3).

<Evaluation>
Example 3
After a corona discharge treatment was performed on one side of the optical film (1) obtained in Example 1, the acrylic adhesive produced in Production Example 1 was laminated using a laminator, and the film was aged for 7 days under conditions of a temperature of 23°C and a relative humidity of 65%, to obtain an optical film with an adhesive. Next, the optical film with the adhesive was cut into a size of 30 mm x 30 mm and laminated to an alkali-free glass (trade name "EAGLE XG" manufactured by Corning Incorporated) to prepare a sample. The absorbance of the prepared sample in the wavelength range of 300 to 800 nm was measured using a spectrophotometer (UV-2450: manufactured by Shimadzu Corporation). The sample after the measurement was placed in a weather resistance tester (Sunshine Weather Meter: manufactured by Suga Test Instruments Co., Ltd.) and subjected to a weather resistance test for 24 hours, after which the absorbance of the sample taken out was measured again. From the measured absorbance, the absorbance retention rate of the sample at 405 nm was calculated based on the following formula. The results are shown in Table 1. The closer the absorbance retention rate is to 100, the less the selective light absorption function deteriorates and the better the weather resistance is. Note that the absorption of alkali-free glass at wavelengths of 405 nm and 440 nm is almost zero.
Absorbance retention rate = A(405) after durability test / A(405) before durability test x 100

Example 4
The optical film (2) was evaluated in the same manner as in Example 3, except that the optical film was replaced with the optical film (2) obtained in Example 2. The results are shown in Table 1.

<Comparative Example 1>
The evaluation was carried out in the same manner as in Example 3, except that a corona discharge treatment was performed on one side of a 40 μm-thick triacetyl cellulose film (trade name "KC4CW" available from Konica) and then the adhesive layer (2) was attached using a laminator.

<Comparative Example 2>
The evaluation was carried out in the same manner as in Example 3, except that a corona discharge treatment was performed on one side of a 40 μm-thick triacetyl cellulose film (trade name "KC4CW" available from Konica) and then the adhesive layer (3) was attached using a laminator.

The optical film of the present invention has a good light absorption ability (A(405)) at a wavelength of about 405 nm. Therefore, when the optical film of the present invention is laminated on a retardation film or an organic EL element, the optical film of the present invention absorbs short-wavelength visible light at a wavelength of about 405 nm, and can block short-wavelength visible light to the retardation film or the organic EL element, thereby suppressing deterioration of the retardation film or the organic EL element from short-wavelength visible light.
The optical film of the present invention has good light absorption function (good absorbance retention) at a wavelength of about 405 nm even after weather resistance testing, and has good weather resistance (durability). Therefore, the optical film of the present invention can maintain the function of suppressing deterioration of a retardation film or an organic EL element caused by short-wavelength visible light. In addition, the optical film of the present invention has low light absorption performance at a wavelength of about 440 nm, does not inhibit the light emission of a liquid crystal display device, and is capable of good color expression.

The optical film of the present invention is suitable for use in liquid crystal panels and liquid crystal display devices.

REFERENCE SIGNS LIST 1 Optical film of the present invention 2 Pressure-sensitive adhesive layer 3 Separate film 4 Protective film 5 Adhesive layer 6 Polarizing film 7, 7a Pressure-sensitive adhesive layer 8 Protective film 30 Light-emitting element 40 Optical film 50, 50a 1/4 wavelength retardation layer 60 Adhesive layer 70 1/2 wavelength retardation layer 80 Positive C layer 10 Optical film with pressure-sensitive adhesive layer 100 Polarizing plate 10A, 10B, 10C, 10D Optical laminate

Claims (11)

An optical film formed from a resin composition containing a resin (A) and a light selective absorbing compound (B) (excluding cases where the light selective absorbing compound (B) is an indole-based compound or a benzotriazole-based compound),
The resin (A) is at least one resin selected from the group consisting of a cellulose-based resin, a (meth)acrylic-based resin, a polyester-based resin, a polyamide-based resin, a polyimide-based resin, and a cycloolefin-based resin;
An optical film satisfying the following formula (1) and formula (2') (excluding the case where the optical film contains a fluorescent whitening agent) :
A(405)≧0.5 (1)
A(440)≦0.04 (2')
[In formula (1), A(405) represents absorbance at a wavelength of 405 nm.
In formula (2'), A(440) represents absorbance at a wavelength of 440 nm. The optical film according to claim 1 , which satisfies the following formula (2″):
A(440)≦0.03 (2'')
[In formula (2″), A(440) represents the absorbance at a wavelength of 440 nm.] The optical film according to claim 1 or 2, further satisfying the following formula (3):
A(405)/A(440)≧5 (3)
[In formula (3), A(405) represents the absorbance at a wavelength of 405 nm, and A(440) represents the absorbance at a wavelength of 440 nm.] The optical film according to any one of claims 1 to 3, which has a storage modulus E at 23°C of 100 MPa or more. The optical film according to any one of claims 1 to 4, wherein the content of the light selective absorbing compound (B) is 0.01 to 20 parts by mass per 100 parts by mass of the resin (A). 6. The optical film according to claim 1, wherein the light selective absorption compound (B) is a compound satisfying formula (4).
ε(405)≧20 (4)
(In formula (5), ε(405) represents the gram absorption coefficient of the compound at a wavelength of 405 nm. The unit of the gram absorption coefficient is L/(g cm).) 7. The optical film according to claim 6, wherein the light selective absorption compound (B) is a compound satisfying formula (5).
ε(405)/ε(440)≧20 (5)
[In formula (6), ε(405) represents the gram absorbance coefficient of the compound at a wavelength of 405 nm, and ε(440) represents the gram absorbance coefficient at a wavelength of 440 nm.] The optical film according to any one of claims 1 to 7, wherein the light selective absorption compound (B) is a compound having a merocyanine structure in the molecule. The optical film according to claim 1 , which satisfies the following formula (2′″):
A(440)≦0.018 (2''')
[In formula (2'''), A(440) represents the absorbance at a wavelength of 440 nm.] An optical film with adhesive, comprising an optical film according to any one of claims 1 to 9, and an adhesive layer on at least one side of the optical film. A display device having the adhesive-attached optical film according to claim 10.