JP7182913B2 - Adhesive sheet and film with adhesive layer - Google Patents

Description

TECHNICAL FIELD The present invention relates to an adhesive sheet and an adhesive layer-attached film using the adhesive sheet.

Various members such as display elements such as organic EL elements and liquid crystal cells and optical films such as polarizing plates are used in display apparatuses (FPDs: flat panel displays) such as organic EL display apparatuses and liquid crystal display apparatuses. Since organic EL compounds, liquid crystal compounds, and the like used for these members are organic substances, deterioration due to ultraviolet rays (UV) tends to pose a problem. In order to solve such problems, for example, Patent Literature 1 describes a polarizing plate in which a protective film for the polarizing plate is added with an ultraviolet absorber having excellent ultraviolet absorption performance in the wavelength region of 370 nm or less.

JP 2006-308936 A

In addition, as display devices have become thinner in recent years, development of a liquid crystal retardation film formed by aligning and photocuring a polymerizable liquid crystal compound has been progressing. It has become clear that these liquid crystal retardation films and organic EL light-emitting devices tend to deteriorate not only by ultraviolet rays but also by short-wave visible light around 400 nm. However, although the polarizing plate described in Patent Document 1 has excellent ultraviolet absorption performance in the wavelength range of 370 nm or less, it has low absorption performance for visible light near 400 nm, and deterioration of the liquid crystal retardation film and the organic EL light emitting device. In some cases, suppression was not sufficient. Further, recent display devices are required to have better display characteristics.

An object of the present invention is to provide a pressure-sensitive adhesive sheet having a function of suppressing deterioration of a retardation film or an organic EL light-emitting device due to ultraviolet light or short-wavelength visible light.

The present invention includes the following inventions.
[1] A pressure-sensitive adhesive sheet formed from a pressure-sensitive adhesive composition containing a (meth)acrylic resin (A) and a photoselective absorption compound, the pressure-sensitive adhesive sheet satisfying the following formulas (1) and (2).
A(350)≧0.5 (1)
A(405)≧0.5 (2)
[In formula (1), A(350) represents absorbance at a wavelength of 350 nm.
In formula (2), A(405) represents absorbance at a wavelength of 405 nm. ]
[2] The pressure-sensitive adhesive sheet according to [1], which further satisfies the following formula (3).
A(440)≦0.1 (3)
[In formula (3), A(440) represents absorbance at a wavelength of 440 nm. ]
[3] The pressure-sensitive adhesive sheet according to [1], which further satisfies the following formula (4).
A(405)/A(440)>5 (4)
[In formula (4), A(405) represents absorbance at a wavelength of 405 nm, and A(440) represents absorbance at a wavelength of 440 nm. ]
[4] Any one of [1] to [3], wherein the light selective absorption compound includes a compound that selectively absorbs light with a wavelength of 350 nm and a compound that selectively absorbs light with a wavelength of 405 nm. The adhesive sheet described in .
[5] The pressure-sensitive adhesive sheet according to [4], wherein the compound that selectively absorbs light with a wavelength of 405 nm is a compound that satisfies formula (5).
ε(405)≧20 (5)
[In formula (5), ε(405) represents the gram extinction coefficient of the compound at a wavelength of 405 nm. The unit of gram extinction coefficient is L/(g·cm). ]
[6] The pressure-sensitive adhesive sheet according to [5], wherein the compound that selectively absorbs light with a wavelength of 405 nm is a compound that satisfies formula (6).
ε(405)/ε(440)≧20 (6)
[In formula (6), ε(405) represents the gram extinction coefficient of the compound at a wavelength of 405 nm, and ε(440) represents the gram extinction coefficient at a wavelength of 440 nm. ]
[7] The pressure-sensitive adhesive sheet according to any one of [4] to [6], wherein the compound that selectively absorbs light with a wavelength of 405 nm is a compound having a merocyanine structure in its molecule.
[8] The adhesive sheet according to any one of [1] to [7], wherein the adhesive composition further contains a cross-linking agent.
[9] The pressure-sensitive adhesive sheet according to [8], wherein the content of the cross-linking agent (B) is 0.01 to 15 parts by mass with respect to 100 parts by mass of the (meth)acrylic resin (A).
[10] The content of the photoselective absorption compound is 0.01 to 20 parts by mass with respect to 100 parts by mass of the (meth)acrylic resin (A). adhesive sheet.
[11] The optical film with an adhesive layer according to any one of [1] to [10], which is obtained by laminating an optical film on at least one surface of an adhesive sheet.
[12] The polarizing plate with an adhesive layer according to [11], wherein the optical film is a polarizing plate.
[13] A display device comprising the optical film with adhesive according to any one of [11] and [12].

The pressure-sensitive adhesive sheet of the present invention exhibits high absorption selectivity for ultraviolet light and short-wavelength visible light near 405 nm, thereby effectively suppressing deterioration of retardation films and organic EL light-emitting elements due to ultraviolet light and short-wavelength visible light. have a function. In addition, the pressure-sensitive adhesive sheet of the present invention exhibits high absorption selectivity for short-wavelength visible light near a wavelength of 405 nm even after a weather resistance test, and can maintain suppression of deterioration due to ultraviolet rays and short-wavelength visible light. can. When the pressure-sensitive adhesive sheet of the present invention is used in a display device, good display characteristics and durability can be imparted.

An example of the layer structure of the adhesive sheet of the present invention is shown. An example of the layer structure of an optical laminate containing the pressure-sensitive adhesive sheet of the present invention is shown. An example of the layer structure of an optical laminate containing the pressure-sensitive adhesive sheet of the present invention is shown. An example of the layer structure of an optical laminate containing the pressure-sensitive adhesive sheet of the present invention is shown.

The pressure-sensitive adhesive sheet of the present invention is molded from a pressure-sensitive adhesive composition containing a (meth)acrylic resin (A) and a photoselective absorption compound, and satisfies the following formulas (1) and (2).
A(350)≧0.5 (1)
A(405)≧0.5 (2)
[In formula (1), A(350) represents absorbance at a wavelength of 350 nm.
In formula (2), A(405) represents absorbance at a wavelength of 405 nm. ]

A larger value of A(350) indicates higher absorption at a wavelength of 350 nm. If the value of A(350) is less than 0.5, the absorption at a wavelength of 350 nm is low, and the effect of suppressing deterioration of display devices such as retardation films and organic EL elements in ultraviolet rays is small. The value of A(350) is preferably 0.5 or more, more preferably 0.8 or more, and particularly preferably 1.0 or more.

A larger value of A(405) indicates higher 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 the effect of suppressing deterioration of a display device such as a retardation film or an organic EL element in ultraviolet light or short-wavelength visible light is small. The value of A(405) is preferably 0.6 or more, more preferably 0.8 or more, and particularly preferably 1.0 or more. Although the upper limit is not particularly limited, it is usually 10 or less.

The pressure-sensitive adhesive sheet of the present invention further preferably satisfies either formula (3) or formula (4) below, and more preferably satisfies both formula (3) and formula (4) below.
A(440)≦0.1 (3)
[In formula (3), A(440) represents absorbance at a wavelength of 440 nm. ]
A(405)/A(440)≧5 (4)
[In formula (4), A(405) represents absorbance at a wavelength of 405 nm, and 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, there is a tendency to impair good color expression in a display device. Moreover, since the light emission of the display device is inhibited, the luminance is also lowered. The value of A(440) is preferably 0.05 or less, more preferably 0.04 or less, and particularly preferably 0.03. Although there is no particular lower limit, it is usually 0.00001 or more.

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. It means that there is significant absorption. The value of A(405)/A(440) is preferably 10 or more, more preferably 30 or more, and particularly preferably 60 or more.

The pressure-sensitive adhesive layer of the present invention is formed from a pressure-sensitive adhesive composition containing at least a (meth)acrylic resin (A) and a photoselective absorption compound.
The adhesive composition preferably further contains a cross-linking agent.

The photoselective absorption compound is not particularly limited as long as it is a compound that selectively absorbs light with a wavelength of 350 nm or light with a wavelength of 405 nm. The light selective absorption compound preferably contains a compound that selectively absorbs light with a wavelength of 350 nm and a compound that selectively absorbs light with a wavelength of 405 nm.

Examples of the compound that selectively absorbs light with a wavelength of 350 nm (hereinafter sometimes referred to as a photoselective absorption compound (A)) include ultraviolet absorbers. Although the ultraviolet absorber is not particularly limited, for example, oxybenzophenone-based ultraviolet absorbers, benzotriazole-based ultraviolet absorbers, salicylic acid ester-based ultraviolet absorbers, benzophenone-based ultraviolet absorbers, cyanoacrylate-based ultraviolet absorbers, and triazine-based ultraviolet absorbers. and organic ultraviolet absorbers such as agents. More specifically, for example, 5-chloro-2-(3,5-di-sec-butyl-2-hydroxylphenyl)-2H-benzotriazole, (2-2H-benzotriazol-2-yl)-6 -(Linear and side chain dodecyl)-4-methylphenol, 2-hydroxy-4-benzyloxybenzophenone, 2,4-benzyloxybenzophenone and the like. These organic ultraviolet absorbers may be used singly or in combination of two or more.

Commercially available UV absorbers may be used, for example, triazine-based UV absorbers such as "Kemisorb 102" manufactured by Chemipro Kasei Co., Ltd., "ADEKA STAB LA46" and "ADEKA STAB LAF70" manufactured by ADEKA Corporation, and BASF Japan. Company's "tinuvin 109", "tinuvin 171", "tinuvin 234", "tinuvin 326", "tinuvin 327", "tinuvin 328", "tinuvin 928", "tinuvin 400", "tinuvin 460", "tinuvin 405”, “tinuvin 477” and the like. Benzotriazole-based UV absorbers include "ADEKA STAB LA31" and "ADEKA STAB LA36" manufactured by ADEKA Corporation, and "Sumisorb 200", "Sumisorb 250", "Sumisorb 300" and "Sumisorb 340" manufactured by Sumika Chemtex Co., Ltd. and "Sumisorb 350", "Kemisorb 74", "Kemisorb 79" and "Kemisorb 279" manufactured by Chemipro Kasei Co., Ltd., and "TINUVIN 99-2", "TINUVIN 900" and "TINUVIN 928" manufactured by BASF. be done.

Also, the ultraviolet absorber may be an inorganic ultraviolet absorber. Inorganic UV absorbers include titanium oxide, zinc oxide, indium oxide, tin oxide, talc, kaolin, calcium carbonate, titanium oxide composite oxide, zinc oxide composite oxide, ITO (tin-doped indium oxide), ATO. (antimony-doped tin oxide) and the like. Examples of titanium oxide-based composite oxides include silica and alumina-doped zinc oxide. These inorganic UV absorbers can be used singly or in combination of two or more. Also, an organic UV absorber and an inorganic UV absorber may be used in combination.

The compound that selectively absorbs light with a wavelength of 405 nm (hereinafter sometimes referred to as a photoselective absorption compound (B)) is preferably a compound that satisfies the following formula (5), and further the following formula (6): It is more preferable that the compound satisfies
ε(405)≧20 (5)
[In formula (5), ε(405) represents the gram extinction coefficient of the compound at a wavelength of 405 nm. The unit of gram extinction coefficient is L/(g·cm). ]
ε(405)/ε(440)≧20 (6)
[In formula (6), ε(405) represents the gram extinction coefficient of the compound at a wavelength of 405 nm, and ε(440) represents the gram extinction coefficient at a wavelength of 440 nm. ]
The gram absorbance coefficient is measured by the method described in Examples.

A compound having a larger value of ε(405) is more likely to absorb light with a wavelength of 405 nm, and suppresses degradation of the retardation film in ultraviolet light or short-wave visible light. If the value of ε (405) is less than 20 L/(g cm), the content of the photoselective absorption compound (B) in the pressure-sensitive adhesive composition must be increased, otherwise the retardation film or the organic EL light-emitting device will be exposed to ultraviolet light. It tends to be difficult to exhibit the function of suppressing deterioration caused by short-wavelength visible light. When the content of the photoselective absorption compound (B) increases, the photoselective absorption compound (B) may bleed out or be unevenly dispersed, 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, and even more preferably 40 L/(g cm) or more. It is preferably 500 L/(g·cm) or less.

A compound with a larger value of ε (405) / ε (440) absorbs light around 405 nm without hindering the color expression of the display device, suppressing photodegradation of display devices such as retardation films and organic EL elements. can do. 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。］ The compound that selectively absorbs light with a wavelength of 405 nm is preferably a compound containing a merocyanine structure in its molecule. 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-based compounds and cyanine-based compounds. compounds, indole-based compounds, benzotriazole-based compounds, and the like. Preferred are merocyanine-based compounds, cyanine-based compounds and benzotriazole-based compounds, and more preferred are compounds represented by formula (I).

[In the formula, R ¹ and R ⁵ are each independently a hydrogen atom, an optionally substituted alkyl group having 1 to 25 carbon atoms, an optionally substituted represents an aralkyl group having 15 carbon atoms, an aryl group having 6 to 15 carbon atoms, or a heterocyclic group, and —CH ₂ — contained in the alkyl group or aralkyl group is —NR ^1A —, —CO—, —SO ₂ —, —O - or -S- may be substituted.
R ^1A represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms.
R ² , R ³ and R ⁴ are each independently a hydrogen atom, an optionally substituted C 1-6 alkyl group, an optionally substituted aromatic hydrocarbon group or an optionally substituted aromatic heterocyclic group, and -CH ₂ - contained in the alkyl group is -NR ^1B -, -CO-, -SO ₂ -, -O- or -S- may be substituted with
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 linked together to form a ring structure .
R ¹ and R ² may be linked together to form a ring structure, R ² and R ³ may be linked together to form a ring structure, R ² and R ⁴ may be linked together to form a ring structure and R ³ and R ⁶ may be linked together to form a ring structure. ]

Examples of alkyl groups having 1 to 25 carbon atoms represented by R ¹ and R ⁵ include methyl group, ethyl group, n-propyl group, isopropyl group, 2-cyanopropyl group, n-butyl group, tert-butyl group, sec-butyl group, n-pentyl group, n-hexyl group, 1-methylbutyl group, 3-methylbutyl group, n-octyl group, n-decyl, 2-hexyl-octyl group and the like.
Examples of substituents that the alkyl group having 1 to 25 carbon atoms represented by R ¹ and R ⁵ may have include groups described in Group A below.
Group A: nitro group, hydroxy group, carboxy group, sulfo group, cyano group, amino group, halogen atom, alkoxy group having 1 to 6 carbon atoms, alkylsilyl group having 1 to 12 carbon atoms, alkyl having 2 to 8 carbon atoms carbonyl group, *-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, and R ^a3 represents 1 to 6 carbon atoms; 6, and s1 represents an integer of 1 to 3.), and the like.
Examples of alkylsilyl groups 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; A trialkylsilyl group such as a tripropylsilyl group can be mentioned.
The alkylcarbonyl group having 2 to 8 carbon atoms includes methylcarbonyl group, ethylcarbonyl group and the like.
A fluorine atom, a chlorine atom, a bromine atom etc. are mentioned as a halogen atom.

Examples of the aralkyl group having 7 to 15 carbon atoms represented by R ¹ and R ⁵ include benzyl group and phenylethyl group. A group in which —CH ₂ — contained in an aralkyl group is replaced with —SO ₂ — or —COO— includes a 2-phenylacetate ethyl group and the like.
Examples of the substituent which the aralkyl group having 7 to 15 carbon atoms represented by R ¹ and R ⁵ may have include the groups described in the above group A.
The aryl group having 6 to 15 carbon atoms represented by R ¹ and R ⁵ includes phenyl group, naphthyl group, anthracenyl group and the like.
Examples of the substituent which the aryl group having 6 to 15 carbon atoms represented by R ¹ and R ⁵ may have include the groups described in the above group A.
Heterocyclic groups having 6 to 15 carbon atoms represented by R ¹ and R ⁵ include carbon atoms such as pyridyl, pyrrolidyl, quinolyl, thiophene, imidazolyl, oxazolyl, pyrrole, thiazolyl and furanyl groups. Aromatic heterocyclic groups of numbers 3 to 9 can be mentioned.

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

Examples of the alkyl group having 1 to 6 carbon atoms represented by R ² , R ³ and R ⁴ include the same alkyl groups having 1 to 6 carbon atoms represented by R ^1B .
Examples of the substituent which 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 the above group A.
Aromatic hydrocarbon groups represented by R ² , R ³ and R ⁴ include aryl groups having 6 to 15 carbon atoms such as phenyl group, naphthyl group and anthracenyl group; 15 aralkyl groups are mentioned.
Examples of substituents that the aromatic hydrocarbon group represented by R ² , R ³ and R ⁴ may have include the groups described in Group A above.
The aromatic heterocyclic ring represented by R ² , R ³ and R ⁴ includes 3 carbon atoms such as pyridyl group, pyrrolidyl group, quinolyl group, thiophene group, imidazolyl group, oxazolyl group, pyrrole group, thiazolyl group and furanyl group. to 9 aromatic heterocyclic groups.
Examples of substituents that the aromatic heterocyclic rings 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 R ⁶ and R ⁷ include the same alkyl groups having 1 to 25 carbon atoms represented by R ¹ and R ⁵ .
Examples of the substituent which the alkyl group having 1 to 25 carbon atoms represented by R ⁶ and R ⁷ may have include the groups described in the above group A.

［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 R ⁶ and R ⁷ include the same alkyl groups having 1 to 25 carbon atoms represented by R ¹ and R ⁵ .
Electron-withdrawing groups represented by R ⁶ and R ⁷ include, for example, 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. ]

Halogen atoms include fluorine, chlorine, bromine and iodine atoms.
Alkyl groups substituted with halogen atoms include, for example, trifluoromethyl group, perfluoroethyl group, perfluoropropyl group, perfluoroisopropyl group, perfluorobutyl group, perfluorosec-butyl group, perfluorotert-butyl group, perfluoropentyl group and A perfluoroalkyl group such as a perfluorohexyl group and the like are included. The number of carbon atoms in the halogen-substituted alkyl group is usually 1-25.

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

The ring structure formed by bonding R ² and R ³ together is a nitrogen-containing ring structure containing a nitrogen atom bonded to R ² , for example, a 4- to 14-membered nitrogen-containing heterocyclic ring. mentioned. The ring structure formed by combining R ² and R ³ may be monocyclic or polycyclic. Specific examples include pyrrolidine ring, pyrroline ring, imidazolidine ring, imidazoline ring, oxazoline ring, thiazoline ring, piperidine ring, morpholine ring, piperazine ring, indole ring, and isoindole ring.

The ring structure formed by bonding R ¹ and R ² together is a nitrogen-containing ring structure containing the nitrogen atom to which R ¹ and R ² are bonded, such as a 4- to 14-membered ring (preferably 4- to 8-membered) nitrogen-containing heterocycles. The ring structure formed by combining R ¹ and R ² may be monocyclic or polycyclic. Specific examples include the same ring structure formed by connecting R ² and R ³ to each other.

The ring structure formed by combining R ² and R ⁴ includes a 4- to 14-membered nitrogen-containing ring structure, preferably a 5- to 9-membered nitrogen-containing ring structure. The ring structure formed by combining R ² and R ⁴ may be monocyclic or polycyclic. These rings may have a substituent, and examples of such a ring structure include those exemplified as the ring structure formed by R ² and R ³ above.

The ring structure formed by connecting R ³ and R ⁶ together is a ring structure in which R ³ —C═C—C═C—R ⁶ forms a ring skeleton. For example, a phenyl group and the like can be mentioned.

［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。］ Compounds represented by formula (I) in which R ² and R ³ are linked together to form a ring structure include compounds represented by formula (IA), and R ² and R ⁴ are Examples of the compound represented by formula (I) which is linked to form a ring structure include compounds represented by formula (IB).

[In formulas (IA) and (IB), R ¹ , R ³ , R ⁴ , R ⁵ , R ⁶ and R ⁷ each have the same meaning as above.
Ring W ¹ and ring W ² each independently represent a nitrogen-containing ring. ]

Ring W ¹ and ring W ² each represent a nitrogen-containing ring containing a nitrogen atom as a ring constituent unit. Ring W ¹ and ring W ² may each independently be monocyclic or polycyclic, and may contain a heteroatom other than nitrogen as a ring constituent unit. Ring W ¹ and ring W ² are each independently preferably a 5- to 9-membered ring.

［式（Ｉ－Ａ）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), R ¹ , R ⁴ , R ⁵ , R ⁶ and R ⁷ each have the same meaning as 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.
R ^1D 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) and a compound represented by formula (IB-2).

[In formula (IB-1), R ¹ , R ⁶ and R ⁷ each have the same meaning as 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 above.
R ³⁰ is 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, or an aromatic hydrocarbon having 6 to 18 carbon atoms. group, 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 is 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 optionally substituted amino group or a heterocyclic group; show. ]

Halogen atoms represented by R ³⁰ include fluorine, chlorine, bromine and iodine atoms.
The acyl group having 2 to 13 carbon atoms represented by R ³⁰ includes acetyl group, propionyl ^group and butyryl group.
The acyloxy group having 2 to 13 carbon atoms represented by R ³⁰ includes methylcarbonyloxy, ethylcarbonyloxy, propylcarbonyloxy, butylcarbonyloxy and the like.
Examples of the alkoxycarbonyl group having 2 to 13 carbon atoms represented by R ³⁰ include methoxycarbonyl group, ethoxycarbonyl group, propoxycarbonyl group and 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 phenyl group, naphthyl group and biphenyl group; to 18 aralkyl groups.
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 alkyl groups having 1 to 12 carbon atoms represented by R ³⁰ include methoxy, ethoxy, propoxy, butoxy and pentoxy groups.
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 methylthio group, ethylthio group, propylthio group, butylthio group, pentylthio group and hexylthio group.
The optionally substituted amino group represented by R ³¹ includes an amino group; amino group; amino group substituted with two alkyl groups having 1 to 8 carbon atoms such as N,N-dimethylamino group, N,N-diethylamino group and N,N-methylethylamino group;
Examples of the heterocyclic ring represented by R ³¹ include nitrogen-containing heterocyclic groups having 4 to 9 carbon atoms such as pyrrolidinyl, piperidinyl and morpholinyl groups.

［式（Ｉ－Ｃ）中、Ｒ^１、Ｒ^６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^２５）＝を表す。
Ｒ^２５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。］ The compound represented by formula (I) in which R ³ and R ⁶ are linked together to form a ring structure, and R ² and R ⁴ are linked together to form a ring structure include formula (IC) Compounds represented by and the like.

[In formula (IC), R ^{1 ,} R ⁶ and R ⁷ have the same meanings as 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.
X ² and X ³ each independently represent -CH ₂ - or -N(R ²⁵ )=.
R ²⁵ represents a hydrogen atom, an alkyl group having 1 to 25 carbon atoms, or an optionally substituted aromatic hydrocarbon group. ]

Examples of the alkyl group having 1 to 25 carbon atoms represented by R ²⁵ include the same alkyl groups having 1 to 25 carbon atoms represented by R ¹ .
Examples of the aromatic hydrocarbon group represented by R ²⁵ include an aryl group such as a phenyl group and a naphthyl group; an aralkyl group such as a benzyl group and a phenylethyl group; and a biphenyl group. A hydrocarbon group is preferred. Examples of the substituent that the aromatic hydrocarbon group represented by R ²⁵ may have include a hydroxy group and the like.

Preferably, R ³ and R ⁶ are each independently 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。］ Compounds represented by formula (I) in which R ¹ and R ² are linked together to form a ring structure, and R ³ and R ⁶ are linked together to form a ring structure include formula (I-D) Compounds represented by and the like.

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

［式（Ｉ－Ｅ）中、Ｒ^１、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。 Compounds (I) in which R ⁶ and R ⁷ are linked together to form a ring structure include compounds represented by formula (IE).

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

［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 above.
R ¹⁷ , R ¹⁸ , R ¹⁹ and R ^q each independently represent a hydrogen atom or an optionally substituted alkyl group, aralkyl group or aryl group having 1 to 12 carbon atoms, and the alkyl group or The —CH ₂ — group contained in the aralkyl group may be substituted with —NR ^1D —, —C(═O)—, —C(═S)—, —O—, —S—, and R ¹⁷ and R ¹⁸ may be linked together to form a ring structure, R ¹⁸ and R ¹⁹ may be linked together to form a ring structure, R ¹⁹ and R ^q may be linked together to form a ring structure You may m, p and q each independently represents an integer of 0 to 3; ]

Compounds represented by formula (I) include the following compounds.

The total content of the photoselective absorption compound is usually 0.01 to 20 parts by mass, preferably 0.05 to 15 parts by mass, with respect to 100 parts by mass of the (meth)acrylic resin (A), It is more preferably 0.1 to 10 parts by mass, still more preferably 0.1 to 5 parts by mass.
The mass ratio of the photoselective absorption compound (A) and the photoselective absorption compound (B) (photoselective absorption compound (A)/photoselective absorption compound (B)) is usually 0.05 to 20, preferably 0. .1-10.

<(Meth) acrylic resin (A)>
The (meth)acrylic resin (A) is preferably a polymer containing (preferably at least 50% by mass) a structural unit derived from a (meth)acrylic acid ester as a main component. Structural units derived from (meth)acrylic acid ester include structural units derived from one or more monomers other than (meth)acrylic acid ester (for example, structural units derived from monomers having polar functional groups). may contain. In this specification, (meth)acrylic acid means either acrylic acid or methacrylic acid, and "(meth)" when referring to (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 (meth)acrylic acid esters 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 of the alkyl group or the aralkyl group Atoms may be replaced by alkoxy groups having 1 to 10 carbon atoms. ]

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

As the (meth)acrylic acid ester represented by formula (I),
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, (meth)acrylic acid Linear alkyl esters of (meth)acrylic acid such as lauryl, stearyl (meth)acrylate, etc.;
i-propyl (meth)acrylate, i-butyl (meth)acrylate, t-butyl (meth)acrylate, i-pentyl (meth)acrylate, i-hexyl (meth)acrylate, (meth)acrylic acid Branched (meth)acrylic acids such as 2-ethylhexyl, i-octyl (meth)acrylate, i-nonyl (meth)acrylate, i-stearyl (meth)acrylate, i-amyl (meth)acrylate, etc. Alkyl ester;
Cyclohexyl (meth)acrylate, isobornyl (meth)acrylate, adamantyl (meth)acrylate, dicyclopentanyl (meth)acrylate, cyclododecyl (meth)acrylate, methylcyclohexyl (meth)acrylate, ( alicyclic skeleton-containing alkyl esters of (meth)acrylic acid such as trimethylcyclohexyl meth)acrylate, tert-butylcyclohexyl (meth)acrylate, cyclohexyl α-ethoxyacrylate;
Esters containing aromatic ring skeletons of (meth)acrylic acid such as phenyl (meth)acrylate;
etc.
Substituent-containing (meth)acrylic acid alkyl esters in which substituents are introduced into the alkyl groups of (meth)acrylic acid alkyl esters can also be mentioned. The substituent of the substituent-containing (meth)acrylic acid alkyl ester is a group that substitutes a hydrogen atom of an alkyl group, and specific examples thereof include a phenyl group, an alkoxy group, and a phenoxy group. Specific examples of substituent-containing (meth)acrylic acid alkyl esters include 2-methoxyethyl (meth)acrylate, ethoxymethyl (meth)acrylate, phenoxyethyl (meth)acrylate, and 2-(meth)acrylate. (2-phenoxyethoxy)ethyl, phenoxydiethylene glycol (meth)acrylate, phenoxypoly(ethylene glycol) (meth)acrylate and the like.

These (meth)acrylic acid esters may be used singly or in combination.

The (meth)acrylic resin (A) comprises a structural unit derived from an alkyl acrylate ester (a1) whose homopolymer glass transition temperature Tg is less than 0°C, and an alkyl acrylate whose homopolymer Tg is 0°C or higher. It preferably contains a structural unit derived from the ester (a2). Containing structural units derived from the alkyl acrylate ester (a1) and structural units derived from the alkyl acrylate ester (a2) is advantageous for enhancing the high-temperature durability of the pressure-sensitive adhesive layer. For the Tg of the homopolymer of (meth)acrylic acid alkyl ester, literature values such as POLYMER HANDBOOK (Wiley-Interscience) can be adopted.

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

The acrylic acid alkyl ester (a1) may be used alone or in combination of two or more. Among them, n-butyl acrylate, n-octyl acrylate, 2-ethylhexyl acrylate, and the like are preferable from the viewpoint of followability and reworkability when the pressure-sensitive adhesive sheet of the present invention is laminated on an optical film.

The alkyl acrylate (a2) is an (alkyl acrylate) other than the alkyl acrylate (a1). Specific examples of the alkyl acrylate (a2) include methyl acrylate, cyclohexyl acrylate, isobornyl acrylate, Including stearyl acrylate, t-butyl acrylate and the like.

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

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

As the structural unit derived from a monomer other than the (meth)acrylic acid ester, a structural unit derived from a monomer having a polar functional group is preferable, and a structure derived from a (meth)acrylic acid ester having a polar functional group. Units are more preferred. Polar functional groups include hydroxy groups, carboxyl groups, substituted or unsubstituted amino groups, and heterocyclic groups such as epoxy groups.
As a monomer having a polar functional group,
1-hydroxymethyl (meth)acrylate, 1-hydroxyethyl (meth)acrylate, 1-hydroxyheptyl (meth)acrylate, 1-hydroxybutyl (meth)acrylate, 1-hydroxypentyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 2-hydroxypentyl (meth)acrylate, 2-hydroxyhexyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 3-hydroxybutyl (meth)acrylate, 3-hydroxypentyl (meth)acrylate, 3-hydroxyhexyl (meth)acrylate, 3-hydroxyheptyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 4-hydroxypentyl (meth)acrylate, 4-hydroxyhexyl (meth)acrylate, 4-hydroxyheptyl (meth)acrylate, 4-hydroxyoctyl (meth)acrylate, 2-chloro-2-hydroxypropyl (meth)acrylate, 3-chloro-2-hydroxypropyl (meth)acrylate, 2-hydroxy-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-hydroxy (meth)acrylate Octyl, 8-hydroxynonyl (meth)acrylate, 8-hydroxydecyl (meth)acrylate, 8-hydroxyundecyl (meth)acrylate, 8-hydroxydodecyl (meth)acrylate, 9-(meth)acrylate Hydroxynonyl, 9-hydroxydecyl (meth)acrylate, 9-hydroxyundecyl (meth)acrylate, 9-hydroxydodecyl (meth)acrylate, (meth)acrylate 9-hydroxytridecyl lylate, 10-hydroxydecyl (meth)acrylate, 10-hydroxyundecyl (meth)acrylate, 10-hydroxydodecyl (meth)acrylate, 10-hydroxytridecyl acrylate, (meth) 10-hydroxytetradecyl acrylate, 11-hydroxyundecyl (meth)acrylate, 11-hydroxydodecyl (meth)acrylate, 11-hydroxytridecyl (meth)acrylate, 11-hydroxytetradecyl (meth)acrylate , 11-hydroxypentadecyl (meth)acrylate, 12-hydroxydodecyl (meth)acrylate, 12-hydroxytridecyl (meth)acrylate, 12-hydroxytetradecyl (meth)acrylate, 13 (meth)acrylic acid -hydroxypentadecyl, 13-hydroxytetradecyl (meth)acrylate, 13-hydroxypentadecyl (meth)acrylate, 14-hydroxytetradecyl (meth)acrylate, 14-hydroxypentadecyl (meth)acrylate, ( monomers having a hydroxy group such as 15-hydroxypentadecyl meth)acrylate and 15-hydroxyheptadecyl (meth)acrylate;
Monomers having a carboxyl group such as (meth)acrylic acid, carboxyalkyl (meth)acrylate (e.g., carboxyethyl (meth)acrylate, carboxypentyl (meth)acrylate), maleic acid, maleic anhydride, fumaric acid, and crotonic acid body;
acryloylmorpholine, vinylcaprolactam, N-vinyl-2-pyrrolidone, vinylpyridine, tetrahydrofurfuryl (meth)acrylate, caprolactone-modified tetrahydrofurfuryl acrylate, 3,4-epoxycyclohexylmethyl (meth)acrylate, glycidyl (meth)acrylate, a monomer having a heterocyclic group such as 2,5-dihydrofuran;
Monomers having a substituted or unsubstituted amino group such as aminoethyl (meth)acrylate, N,N-dimethylaminoethyl (meth)acrylate, and dimethylaminopropyl (meth)acrylate can be mentioned.
Among them, from the viewpoint of reactivity between the (meth)acrylic acid ester polymer and the cross-linking agent, a monomer having a hydroxy group or a monomer having a carboxyl group is preferable, and a monomer having a hydroxy group and a carboxyl group are preferred. It is more preferable to include any monomer having a group.

Preferred hydroxy group-containing monomers are 2-hydroxyethyl acrylate, 3-hydroxypropyl acrylate, 4-hydroxybutyl acrylate, 5-hydroxypentyl acrylate, and 6-hydroxyhexyl acrylate. In particular, good durability can be obtained by using 2-hydroxyethyl acrylate, 4-hydroxybutyl acrylate and 5-hydroxypentyl acrylate.
Acrylic acid is preferably used as the monomer having a carboxyl group.

From the viewpoint of preventing enhancement of the peeling force of the separate film that can be laminated on the outer surface of the pressure-sensitive adhesive sheet, the (meth)acrylic resin (A) substantially contains a structural unit derived from a monomer having an amino group. preferably not. Here, "substantially not included" means that it is 0.1 part by mass or less in 100 parts by mass of all structural units constituting the (meth)acrylic resin (a).

The content of structural units derived from a monomer having a polar functional group is preferably 20 parts by mass or less, more preferably 0 parts by mass, based on 100 parts by mass of all structural units of the (meth)acrylic resin (A). 0.5 to 15 parts by mass, more preferably 0.5 to 10 parts by mass, particularly preferably 1 to 7 parts by mass.

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

Structural units derived from monomers other than (meth)acrylic acid esters include structural units derived from styrene monomers, structural units derived from vinyl monomers, and multiple (meth)acryloyl A structural unit derived from a monomer having a group, a structural unit derived from a (meth)acrylamide-based monomer, and the like are also included.

Styrenic monomers include styrene; alkylstyrenes such as methylstyrene, dimethylstyrene, trimethylstyrene, ethylstyrene, diethylstyrene, triethylstyrene, propylstyrene, butylstyrene, hexylstyrene, heptylstyrene and octylstyrene; Halogenated styrenes such as chlorostyrene, bromostyrene, dibromostyrene, 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; 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 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,9-nonanediol di( Two (meth)acryloyl groups in the molecule of meth)acrylate, ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, tripropylene glycol di(meth)acrylate, etc. Monomer having three (meth)acryloyl groups in the molecule, such as trimethylolpropane tri(meth)acrylate.

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

The (meth)acrylic resin (A) preferably has a weight average molecular weight (Mw) of 500,000 to 2,500,000. When the weight-average molecular weight is 500,000 or more, the durability of the adhesive sheet in a high-temperature environment is improved, and defects such as floating and peeling between the adherend and the adhesive sheet and cohesive failure of the adhesive sheet are prevented. easy to suppress. A weight average molecular weight of 2,500,000 or less is advantageous in terms of coatability. From the viewpoint of compatibility between the durability of the adhesive sheet 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 100. 10,000 to 1,600,000. Further, the molecular weight distribution (Mw/Mn) represented by the ratio of the weight average molecular weight (Mw) to the number average molecular weight (Mn) is usually 2 to 10, preferably 3 to 8, more preferably 3 to 6. . The weight average molecular weight can be analyzed by gel permeation chromatography and is a value converted to standard polystyrene.

The (meth)acrylic acid resin (A) is dissolved in ethyl acetate to form a solution having a concentration of 20% by mass, and the viscosity at 25° C. is preferably 20 Pa s or less, preferably 0.1 to 15 Pa s. is more preferable. A viscosity within 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) is, for example, -60 to 20°C, preferably -50 to 15°C, more preferably -45 to 10°C, particularly -40 to 0°C. may When the Tg is equal to or lower than the upper limit, it is advantageous for improving the wettability of the adhesive sheet to the adherend substrate, and when it is equal to or higher than the lower limit, it is advantageous for improving the durability of the adhesive sheet. The glass transition temperature can be measured with a differential scanning calorimeter (DSC).

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

A thermal polymerization initiator, a photopolymerization initiator, or the like is used as the polymerization initiator. Photopolymerization initiators include 4-(2-hydroxyethoxy)phenyl(2-hydroxy-2-propyl)ketone and the like. Thermal polymerization initiators include 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 ), azo compounds such as 2,2′-azobis (2-hydroxymethylpropionitrile); lauryl peroxide, t-butyl hydroperoxide, benzoyl peroxide, t-butyl peroxybenzoate, cumene hydroperoxide, Organic peroxides such as diisopropyl peroxydicarbonate, dipropyl peroxydicarbonate, t-butyl peroxyneodecanoate, t-butyl peroxypivalate, (3,5,5-trimethylhexanoyl) peroxide ; inorganic peroxides such as potassium persulfate, ammonium persulfate and hydrogen peroxide; Redox initiators using a combination of a peroxide and a reducing agent can also be used.

The proportion of the polymerization initiator is about 0.001 to 5 parts by mass with respect to 100 parts by mass of the total amount of monomers constituting the (meth)acrylic resin (A). Polymerization of the (meth)acrylic resin may use a polymerization method using active energy rays (for example, ultraviolet rays).

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; ketones such as acetone, methyl ethyl ketone and methyl isobutyl ketone. is mentioned.

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, based on 100% by mass of the adhesive composition, More preferably, it is 80% by mass to 99% by mass.

The cross-linking agent (B) reacts with the polar functional groups (eg, hydroxyl group, amino group, carboxyl group, heterocyclic group, etc.) in the (meth)acrylic resin (A). The cross-linking agent (B) forms a cross-linked structure with a (meth)acrylic resin or the like to form a cross-linked structure that is advantageous for durability and reworkability.

Examples of the cross-linking agent (B) include isocyanate-based cross-linking agents, epoxy-based cross-linking agents, aziridine-based cross-linking agents, and metal chelate-based cross-linking agents. An isocyanate-based cross-linking agent is preferred from the viewpoint of speed and the like.

The isocyanate compound is preferably a compound having at least two isocyanato groups (--NCO) in the molecule, such as aliphatic isocyanate compounds (eg hexamethylene diisocyanate), alicyclic isocyanate compounds (eg isophorone diisocyanate , hydrogenated diphenylmethane diisocyanate, hydrogenated xylylene diisocyanate), aromatic isocyanate compounds (eg tolylene diisocyanate, xylylene diisocyanate diphenylmethane diisocyanate, naphthalene diisocyanate, triphenylmethane triisocyanate, etc.). The cross-linking agent (B) is an adduct (adduct) of the isocyanate compound with a polyhydric alcohol compound [e.g., an adduct with glycerol, trimethylolpropane, etc.], an isocyanurate compound, a buret type compound, a polyether polyol, a polyester Derivatives such as urethane prepolymer-type isocyanate compounds that are subjected to addition reactions with polyols, acrylic polyols, polybutadiene polyols, polyisoprene polyols, and the like may also be used. The cross-linking agent (B) can be used alone or in combination of two or more. Among these, typically aromatic isocyanate compounds (e.g. tolylene diisocyanate, xylylene diisocyanate), aliphatic isocyanate compounds (e.g. hexamethylene diisocyanate) or polyhydric alcohol compounds thereof (e.g. glycerol, trimethylolpropane) ) or an isocyanurate. If the cross-linking agent (B) is an aromatic isocyanate-based compound and/or a polyhydric alcohol compound thereof, or an adduct of an isocyanurate, it is advantageous for forming an optimum cross-linking density (or cross-linking structure), The durability of the adhesive layer can be improved. In particular, if it is a tolylene diisocyanate-based compound and/or an adduct of these polyhydric alcohol compounds, durability can be improved even when a pressure-sensitive adhesive layer is applied to a polarizing plate, for example.

The content of the cross-linking agent (b) is usually 0.01 to 15 parts by mass, preferably 0.05 to 10 parts by mass, relative to 100 parts by mass of the (meth)acrylic resin (a). It is preferably 0.1 to 5 parts by mass.

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

3-mercaptopropyltrimethoxysilane-tetramethoxysilane oligomer, 3-mercaptopropyltrimethoxysilane-tetraethoxysilane oligomer, 3-mercaptopropyltriethoxysilane-tetramethoxysilane oligomer, 3-mercaptopropyltriethoxysilane-tetraethoxysilane Mercaptopropyl group-containing oligomers such as oligomers; mercaptomethyltrimethoxysilane-tetramethoxysilane oligomer, mercaptomethyltrimethoxysilane-tetraethoxysilane oligomer, mercaptomethyltriethoxysilane-tetramethoxysilane oligomer, mercaptomethyltriethoxysilane-tetraethoxy Mercaptomethyl group-containing oligomers such as silane oligomers; tetramethoxysilane copolymer, 3-glydidoxypropyltriethoxysilane-tetraethoxysilane copolymer, 3-glydidoxypropylmethyldimethoxysilane-tetramethoxysilane copolymer, 3-glydidoxypropylmethyldimethoxysilane-tetraethoxysilane copolymer, 3-glydidoxypropyl group-containing copolymers such as 3-glydidoxypropylmethyldiethoxysilane-tetramethoxysilane copolymer, 3-glydidoxypropylmethyldiethoxysilane-tetraethoxysilane copolymer; methoxysilane-tetramethoxysilane oligomer, 3-methacryloyloxypropyltrimethoxysilane-tetraethoxysilane oligomer, 3-methacryloyloxypropyltriethoxysilane-tetramethoxysilane oligomer, 3-methacryloyloxypropyltriethoxysilane-tetraethoxysilane oligomer, 3-methacryloyloxypropylmethyldimethoxysilane-tetramethoxysilane oligomer, 3-methacryloyloxypropylmethyldimethoxysilane-tetraethoxysilane oligomer, 3-methacryloyloxypropylmethyldiethoxysilane-tetramethoxysilane oligomer, 3-methacryloyloxypropylmethyldi Ethoxysilane-tetraethoxysilane oligomer, etc. 3-acryloyloxypropyltrimethoxysilane-tetramethoxysilane oligomer, 3-acryloyloxypropyltrimethoxysilane-tetraethoxysilane oligomer, 3-acryloyloxypropyltriethoxysilane-tetramethoxysilane oligomer, 3-acryloyloxypropyltriethoxysilane-tetraethoxysilane oligomer, 3-acryloyloxypropylmethyldimethoxysilane-tetramethoxysilane oligomer, 3-acryloyloxypropylmethyldimethoxysilane-tetraethoxysilane oligomer, 3-acryloyloxypropylmethyldiethoxy Acryloyloxypropyl group-containing oligomers such as silane-tetramethoxysilane oligomer, 3-acryloyloxypropylmethyldiethoxysilane-tetraethoxysilane oligomer; vinyltrimethoxysilane-tetramethoxysilane oligomer, vinyltrimethoxysilane-tetraethoxysilane oligomer, Vinyltriethoxysilane-tetramethoxysilane oligomer, Vinyltriethoxysilane-tetraethoxysilane oligomer, Vinylmethyldimethoxysilane-tetramethoxysilane oligomer, Vinylmethyldimethoxysilane-tetraethoxysilane oligomer, Vinylmethyldiethoxysilane-tetramethoxysilane oligomer , vinyl group-containing oligomers such as vinylmethyldiethoxysilane-tetraethoxysilane oligomer; 3-aminopropyltrimethoxysilane-tetramethoxysilane copolymer, 3-aminopropyltrimethoxysilane-tetraethoxysilane copolymer, 3-aminopropyltriethoxy Silane-tetramethoxysilane copolymer, 3-aminopropyltriethoxysilane-tetraethoxysilane copolymer, 3-aminopropylmethyldimethoxysilane-tetramethoxysilane copolymer, 3-aminopropylmethyldimethoxysilane-tetraethoxysilane copolymer, 3-aminopropyl amino group-containing copolymers such as methyldiethoxysilane-tetramethoxysilane copolymer and 3-aminopropylmethyldiethoxysilane-tetraethoxysilane copolymer;

The silane compound (d) may be a silane compound represented by the following formula (d1). When the pressure-sensitive adhesive composition contains a silane compound represented by the following formula (d1), the adhesiveness to substrates, glass, transparent electrodes, etc. can be further improved, so that peeling off and foaming are less likely to occur in high-temperature environments. A durable adhesive layer can be formed.

（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, and constitutes the alkanediyl group and the alicyclic hydrocarbon group —CH ₂ — 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 are each independently represents an alkyl group having 1 to 5 carbon atoms or an alkoxy group having 1 to 5 carbon atoms)

In formula (d1), B is an alkanediyl group having 1 to 20 carbon atoms such as a methylene group, ethylene group, trimethylene group, tetramethylene group, hexamethylene group, heptamethylene group, octamethylene group; 1,2-cyclobutylene group), cyclopentylene group (eg 1,2-cyclopentylene group), cyclohexylene group (eg 1,2-cyclohexylene group), cyclooctylene group (eg 1,2- A divalent alicyclic hydrocarbon group having 3 to 20 carbon atoms such as a cyclooctylene group), or —CH ₂ — constituting these alkanediyl groups and the alicyclic hydrocarbon group is —O— or A group substituted with -CO- is shown. B is preferably an alkanediyl group having 1 to 10 carbon atoms. R ^d7 represents an alkyl group having 1 to 5 carbon atoms such as methyl group, ethyl group, propyl group, isopropyl group, butyl group, s-butyl group, t-butyl group, pentyl group, R ^d8 , R ^d9 , R ^d10 , R ^d11 and R ^d12 are each independently an alkyl group having 1 to 5 carbon atoms exemplified for R ²¹ above, or a methoxy group, ethoxy group, propoxy group, i-propoxy group, butoxy group, s-butoxy group , represents an alkoxy group having 1 to 5 carbon atoms such as t-butoxy group. Preferred R ^d8 , R ^d9 , R ^d10 , R ^d11 and R ^d12 are each independently an alkoxy group having 1 to 5 carbon atoms. These silane compounds (d) can be used alone or in combination of two or more.

Examples of specific silane compounds represented by the formula (d1) include (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(tri-C1- 5-alkoxysilyl)C1-10 alkanes; bis(dimethoxymethylsilyl)methane, 1,2-bis(dimethoxymethylsilyl)ethane, 1,2-bis(dimethoxyethylsilyl)ethane, 1,4-bis(dimethoxymethylsilyl) ) butane, 1,4-bis(dimethoxyethylsilyl)butane, 1,6-bis(dimethoxymethylsilyl)hexane, 1,6-bis(dimethoxyethylsilyl)hexane, 1,8-bis(dimethoxymethylsilyl)octane , 1,8-bis(dimethoxyethylsilyl)octane and other bis(diC1-5alkoxyC1-5alkylsilyl)C1-10 alkanes; 1,6-bis(methoxydimethylsilyl)hexane, 1,8-bis( bis(monoC1-5alkoxy-diC1-5alkylsilyl)C1-10alkanes such as methoxydimethylsilyl)octane; Among these, 1,2-bis(trimethoxysilyl)ethane, 1,3-bis(trimethoxysilyl)propane, 1,4-bis(trimethoxysilyl)butane, 1,5-bis(trimethoxysilyl) Bis(triC1-3alkoxysilyl)C1-10 alkanes such as pentane, 1,6-bis(trimethoxysilyl)hexane, 1,8-bis(trimethoxysilyl)octane are preferred, especially 1,6-bis (Trimethoxysilyl)hexane and 1,8-bis(trimethoxysilyl)octane are preferred.

The content of the silane compound (d) is usually 0.01 to 10 parts by mass, preferably 0.03 to 5 parts by mass, relative to 100 parts by mass of the (meth)acrylic resin (a). It is preferably 0.05 to 2 parts by mass, more preferably 0.1 to 1 part by mass. When it is the upper limit value or less, it is advantageous for suppressing bleeding out of the silane compound (d) from the adhesive layer, and when it is the lower limit value or more, the adhesive layer adheres to a metal layer, a glass substrate, or the like. It becomes easy to improve the property (or adhesiveness), and it is advantageous for improving peeling resistance and the like.

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

The content of the antistatic agent is, for example, 0.01 to 20 parts by mass, preferably 0.1 to 10 parts by mass, more preferably 1 to 7 parts by mass, relative to 100 parts by mass of the (meth)acrylic resin (a). is mass.

The pressure-sensitive adhesive composition can contain one or more additives such as solvents, crosslinking catalysts, tackifiers, plasticizers, softeners, pigments, rust inhibitors, inorganic fillers, and light-scattering fine particles.

<Structure and Manufacturing Method of Adhesive Layer and Optical Film with Adhesive Layer>
The pressure-sensitive adhesive sheet of the present invention is formed, for example, by dissolving or dispersing the pressure-sensitive adhesive composition in a solvent to form a solvent-containing pressure-sensitive adhesive composition, then applying this to the surface of a substrate and drying it. be done. The pressure-sensitive adhesive layer-attached optical film can be produced by laminating the optical film on the pressure-sensitive adhesive sheet surface of the pressure-sensitive adhesive sheet-attached substrate formed above and then peeling off the substrate, and by applying an adhesive composition on a resin film such as an optical film. Examples include a method of applying an object and drying it.
As the base material, a plastic film is suitable, and a specific example thereof is a release film to which a release treatment has been applied. As the release film, one surface of a film made of a resin such as polyethylene terephthalate, polybutylene terephthalate, polycarbonate, or polyarylate is subjected to release treatment such as silicone treatment. A release film may be attached to the adhesive layer sheet for temporary protection of the adhesive sheet.

FIG. 1 shows an example of the layer structure of the pressure-sensitive adhesive sheet of the present invention. The pressure-sensitive adhesive sheet 1 shown in FIG. 1 is in a state where a release film 2 is attached for temporary protection. The release film may be laminated on one side of the pressure-sensitive adhesive sheet, or may be laminated on both sides.
The present invention also includes an optical laminate in which an optical film is laminated on at least one surface of the pressure-sensitive adhesive layer of the present invention. 2 to 4 show optical laminates containing the pressure-sensitive adhesive sheet of the present invention. The optical laminate 10A shown in FIG. 2 is an optical laminate including a protective form 8, an adhesive layer 7, a polarizing film 9, an adhesive layer 7, a protective film 3, an adhesive sheet 1, and a release film 2. The protective film 3 may have retardation. The layer structure of the protective film 8 , the adhesive layer 7 , the polarizing film 9 , the adhesive layer 7 and the protective film 3 corresponds to the polarizing plate represented by the optical film 40 . The optical layered body 10B shown in FIG. 3 and the optical layered body 10C shown in FIG. 40, an adhesive layer 7a, and an optical laminate including a light emitting element 30 (liquid crystal cell, OLED cell).

The optical film 40 is a film having optical functions such as transmitting, reflecting, and absorbing light, and may be a single layer film or a multilayer film. Examples of the optical film 40 include a polarizing film (polarizing plate), a retardation film, a brightness enhancement film, an antiglare film, an antireflection film, a diffusion film, a light collecting film, a window film, and the like. , a window film or a laminated film thereof.

A retardation film is an optical film exhibiting optical anisotropy, and includes, for example, polyvinyl alcohol, polycarbonate, polyester, polyarylate, polyimide, polyolefin, polycycloolefin, polystyrene, polysulfone, polyethersulfone, polyvinylidenefluor A stretched film obtained by stretching a polymer film made of lyde/polymethyl methacrylate, acetyl cellulose, saponified ethylene-vinyl acetate copolymer, polyvinyl chloride or the like to about 1.01 to 6 times. Among them, a polymer film obtained by uniaxially stretching or biaxially stretching a polycarbonate film or a cycloolefin resin film is preferable. In this specification, the retardation film includes a zero retardation film, and also includes a film called a uniaxial retardation film, a low photoelasticity retardation film, a wide viewing angle retardation film, and the like.

Films that exhibit optical anisotropy through the application and orientation of liquid crystalline compounds and films that exhibit optical anisotropy through the application of inorganic layered compounds include films called temperature-compensated retardation films, JX "NH Film" (trade name; film with obliquely aligned rod-shaped liquid crystals) sold by Liquid Crystal Film, and "WV Film" (trade name; film with obliquely aligned disk-shaped liquid crystals) sold by FUJIFILM Corporation. , “VAC Film” (trade name; completely biaxially oriented film) and “new VAC Film” (trade name; biaxially oriented film) sold by Sumitomo Chemical Co., Ltd., and the like.

A zero-retardation film is an optically isotropic film in which both the front retardation R _e and the thickness direction retardation R _th are −15 to 15 nm. Examples of zero retardation films include resin films made of cellulose resins, polyolefin resins (chain polyolefin resins, polycycloolefin resins, etc.) or polyethylene terephthalate resins. Cellulose-based resins or polyolefin-based resins are preferable in that they are easy to use. A zero retardation film can also be used as a protective film. Examples of zero retardation films include "Z-TAC (trade name)" sold by Fuji Film Co., Ltd., "Zerotac (registered trademark)" sold by Konica Minolta, Inc., and Zeon Corporation (sold by Nippon Zeon Co., Ltd.). “ZF-14 (trade name)”, etc.

In the optical film of 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 aligning a liquid crystalline compound include a first form: a retardation film in which a rod-like liquid crystal compound is oriented horizontally with respect to a support substrate, and a second form: a rod-like film. Retardation film in which the liquid crystal compound is oriented in the direction perpendicular to the supporting substrate, third mode: Retardation film in which the direction of orientation of the rod-like liquid crystal compound changes in a spiral manner in the plane, fourth mode: A retardation film in which a discotic liquid crystal compound is obliquely oriented, and a fifth mode: a biaxial retardation film in which a discotic liquid crystal compound is oriented perpendicularly to a support substrate.

For example, as an optical film used for an organic electroluminescence display, the first form, the second form, and the fifth form are preferably used. Alternatively, these may be laminated and used.

When the retardation film is a layer (hereinafter sometimes referred to as an "optically anisotropic layer") composed of a polymer in an aligned state of a polymerizable liquid crystal compound, the retardation film may have reverse wavelength dispersion. preferable. The reverse wavelength dispersion is an optical characteristic 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. (7) and (8) are satisfied. Note that Re(λ) represents an in-plane retardation value for light with a wavelength of λnm.
Re(450)/Re(550)≤1 (7)
1≦Re(630)/Re(550) (8)
In the optical film of the present invention, when the retardation film is in the first form and has reverse wavelength dispersion, it is preferable because coloring during black display on a display device is reduced, and in the above formula (7), 0.82 ≤ More preferably, Re(450)/Re(550)≤0.93. Furthermore, 120≦Re(550)≦150 is preferable.

As the polymerizable liquid crystal compound when the retardation film is a film having an optically anisotropic layer, "3. .8.6 Network (completely crosslinked type)”, “6.5.1 Liquid crystal material b. JP, JP 2010-270108, JP 2011-6360, JP 2011-207765, JP 2011-162678, JP 2016-81035, WO 2017/043438 and polymerizable liquid crystal compounds described in JP-T-2011-207765.

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

In the case of the second embodiment, the front retardation value Re (550) may be adjusted in the range of 0 to 10 nm, preferably in the range of 0 to 5 nm, and the thickness direction retardation value R _th is -10 to -. It may be adjusted in the range of 300 nm, preferably in the range of -20 to -200 nm. The thickness direction retardation value R _th , which means the refractive index anisotropy in the thickness direction, is the retardation value R ₅₀ measured with the in-plane fast axis as the tilt axis and tilted 50 degrees, and the in-plane retardation It can be calculated from the value _R0 . That is, the retardation value R _th in the thickness direction is the in-plane retardation value R ₀ , the retardation value R ₅₀ measured by tilting the fast axis by 50 degrees, the thickness d of the retardation film, and the phase difference value R 50 . From the average refractive index n ₀ of the retardation film, n _x , n _y and n _z are obtained from the following equations (10) to (12), and these values are substituted into the equation (9) for calculation.

R _th =[(n _x +n _y )/2−n _z ]×d (9)
R ₀ =(n _x −n _y )×d (10)
R ₅₀ =(n _x -n _y ') xd/cos(φ) (11)
( _nx + _ny + _nz )/3= _n0 (12)
here,
φ=sin ⁻¹ [sin (40°)/n ₀ ]
ny _′ = _ny × _nz /[ _ny2 × ^sin2 (φ ⁾ + _nz2 × ^cos2 ( ^φ )] ^1/2

The retardation film may be a multilayer film having two or more layers. Examples thereof include a retardation film laminated with a protective film on one side or both sides thereof, and a retardation film laminated with two or more retardation films via a pressure-sensitive adhesive or an adhesive.

The thickness of the retardation film is usually 0.1-100 μm.
When the retardation film has multiple layers, the total thickness may be 0.5 to 200 μm.

When the optical film 40 is a multilayer film in which two or more retardation films are laminated, the configuration of the optical laminate containing the optical film of the present invention is such that the transmitted light has a quarter wavelength A 1/4 wavelength retardation layer 50 that imparts a retardation of 1/4 wavelength and a 1/2 wavelength retardation layer 70 that imparts a 1/2 wavelength retardation to transmitted light, through an adhesive or pressure sensitive adhesive 60 A configuration including a laminated optical film 40 may be mentioned. Moreover, as shown in FIG. 4, there is also a configuration including a science film 40 in which a quarter-wave retardation layer 50a and a positive C layer 80 are laminated via an adhesive layer or pressure-sensitive adhesive layer.

The 1/4 wavelength retardation layer 50 that imparts a 1/4 wavelength phase difference and the 1/2 wavelength retardation layer 70 that imparts a 1/2 wavelength phase difference to transmitted light in FIG. It may be an optical film of the form of (1) or an optical film of the fifth form. In the case of the configuration of FIG. 3, it is more preferable that at least one of them is the fifth mode.

In the case of the configuration of FIG. 4, the quarter-wave retardation layer 50a is preferably the optical film of the first form, and more preferably satisfies the formulas (7) and (8).

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

Generally, a film obtained by forming a polyvinyl alcohol-based resin is used as a raw film for a polarizing film. A polyvinyl alcohol-based resin can be formed into a film by a known method. The thickness of the original film is usually 1 to 150 μm, and preferably 10 μm or more in consideration of ease of stretching.

The polarizing film is, for example, a process of uniaxially stretching the original film, a process of dyeing the film with a dichroic dye to adsorb the dichroic dye, a process of treating the film with an aqueous boric acid solution, and The film is washed with water and finally dried. The thickness of the polarizer 2 is usually 1 to 30 μm, preferably 20 μm or less, more preferably 15 μm or less, particularly 10 μm or less from the viewpoint of thinning the pressure-sensitive adhesive layer-attached optical film 1 .

A polarizing film made by adsorbing and aligning a dichroic dye on a polyvinyl alcohol resin film uses a single film of the polyvinyl alcohol resin film as the raw film, and uniaxially stretches this film and dyes the dichroic dye. In addition to the method of applying a treatment (referred to as method (1)), a substrate film having a polyvinyl alcohol resin layer is obtained by coating a substrate film with a coating solution (aqueous solution, etc.) containing a polyvinyl alcohol resin and drying it. After obtaining, this is uniaxially stretched for each base film, the polyvinyl alcohol-based resin layer after stretching is subjected to a dichroic dyeing treatment, and then the base film is peeled off and removed (Method (2 ) can also be obtained by As the base film, a film made of a thermoplastic resin similar to the thermoplastic resin can be used, preferably a polyester resin such as polyethylene terephthalate, a polycarbonate resin, a cellulose resin such as triacetyl cellulose, a norbornene resin. It is a film made of a cyclic polyolefin-based resin such as a resin, a polystyrene-based resin, or the like. By using the above method (2), it becomes easy to produce a thin polarizing film, and for example, even a polarizer 2 having a thickness of 7 μm or less can be produced easily.

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 composed of aqueous polyvinyl alcohol resin solutions, water-based two-component urethane emulsion adhesives, aldehyde compounds, epoxy compounds, melamine compounds, methylol compounds, isocyanate compounds, cross-linking agents such as amine compounds and polyvalent metal salts). Among these, a water-based adhesive consisting of an aqueous solution of a polyvinyl alcohol-based resin can be preferably used. In the case of using a water-based adhesive, it is preferable to carry out a drying step to remove water contained in the water-based adhesive after laminating the polarizing film and the protective film. After the drying step, a curing step of curing at a temperature of, for example, about 20 to 45°C may be provided. An adhesive layer formed from a water-based adhesive usually has a thickness of 0.001 to 5 μm.

The active energy ray-curable adhesive refers to an adhesive that is cured by irradiation with an active energy ray such as ultraviolet rays or electron beams. A curable composition containing a reactive resin, a curable composition containing a binder resin and a photoreactive cross-linking agent, and the like, preferably an ultraviolet curable adhesive.

When using an active energy ray-curable adhesive, after laminating the polarizing film and the protective film, a drying process is performed as necessary, and then the active energy ray-curable adhesive is cured by irradiating with an active energy ray. Perform a curing step for curing. Although the light source of the active energy ray is not particularly limited, ultraviolet light having a light emission distribution at a wavelength of 400 nm or less is preferable. An adhesive layer formed from an active energy ray-curable adhesive usually has a thickness of 0.1 to 20 μm.

Examples of the method of bonding the polarizing film and the protective film include a method of subjecting the bonding surface of at least one of them to surface activation treatment such as saponification treatment, corona treatment, plasma treatment, and the like. When resin films are laminated on both sides of the polarizing film, the adhesives for laminating these resin films may be of the same type or of different types.

A preferred configuration of the polarizing plate is a polarizing plate in which a protective film is laminated on at least one surface of a polarizing film via an adhesive layer. If the protective film is laminated only on one side of the polarizing film, it is more preferably laminated on the viewing side. The protective film laminated on the viewing side is preferably a protective film made of triacetyl cellulose resin or cycloolefin resin. The protective film may be an unstretched film, or may be stretched in any direction to have retardation. A surface treatment layer such as a hard coat layer or an antiglare layer may be provided on the surface of the protective film laminated on the viewing side.
When the protective film is laminated on both sides of the polarizing film, the protective film on the panel side (the side opposite to the viewing side) is a protective film or retardation film made of triacetyl cellulose resin, cycloolefin resin, or acrylic resin. Preferably. The retardation film may be a zero retardation film, which will be described later.
Another layer or film may be laminated between the polarizing plate and the panel. When used as a circularly polarizing plate for an organic EL display, a retardation layer having a quarter-wave retardation layer and a half-wave retardation layer, and a quarter-wave layer having the reverse wavelength dispersion described above are laminated. preferably. From the viewpoint of thinning, the retardation layer is preferably a liquid crystal retardation film.

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

A brightness enhancement film is used for the purpose of improving brightness in a liquid crystal display device to which a polarizing plate is applied. Specifically, a reflective polarization separation sheet designed to generate anisotropy in reflectance by laminating multiple thin films with different refractive index anisotropy, an oriented film of cholesteric liquid crystal polymer, and its orientation A circularly polarized light separation sheet having a liquid crystal layer supported on a substrate film, and the like.

A window film means a front plate in a flexible display device such as a flexible display, and is generally arranged on the outermost surface of the display device. The window film includes, for example, a resin film made of polyimide resin. The window film may be a hybrid film of organic and inorganic materials, such as a resin film containing polyimide and silica. Further, the window film may have a hard coat layer disposed on its surface to impart surface hardness, antifouling properties, and anti-fingerprint properties. Examples of the window film include films described in JP-A-2017-94488.

The optical laminate containing the pressure-sensitive adhesive layer sheet of the present invention is laminated on a display element such as an organic EL element or a liquid crystal cell, and used in a display device (FPD: flat panel display) such as an organic EL display device or a liquid crystal display device. can do things

The present invention will be described in more detail below with reference to examples and comparative examples. "%" and "parts" in Examples and Comparative Examples are "% by mass" and "parts by mass" unless otherwise specified.

In the following examples, the weight-average molecular weight and number-average molecular weight were measured using a gel permeation chromatography (hereinafter referred to as GPC) apparatus (GPC-8120, manufactured by Tosoh Corporation) with four columns. "TSK gel XL (manufactured by Tosoh Corporation)" and "Shodex GPC KF-802 (manufactured by Showa Denko Co., Ltd.)" are arranged in series, and a total of five are connected in series, and tetrahydrofuran is used as an eluent. was used under the 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.

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１０部、無水酢酸（和光純薬工業株式会社製）３．６部、シアノ酢酸２－エチルヘキシル（ＤＩＰＥＡと称する場合がある；東京化成工業株式会社製）６．９部、およびアセトニトリル（和光純薬工業株式会社製）６０部を仕込み、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）４．５部を滴下漏斗から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４．６部得た。収率は５０％であった。 (Synthesis Example 1) Synthesis of photoselective absorption compound (1)

A Dimroth condenser, a nitrogen atmosphere in a 200 mL-four-necked flask equipped with a thermometer, and 10 parts of the compound represented by the formula (aa) synthesized with reference to Patent Document (JP 2014-194508), acetic anhydride ( Wako Pure Chemical Industries, Ltd.) 3.6 parts, 2-ethylhexyl cyanoacetate (sometimes referred to as DIPEA; Tokyo Chemical Industry Co., Ltd.) 6.9 parts, and acetonitrile (Wako Pure Chemical Industries, Ltd.) 60 The parts were charged and stirred with a magnetic stirrer. At an internal temperature of 25°C, 4.5 parts of DIPEA (manufactured by Tokyo Chemical Industry Co., Ltd.) was added dropwise from the dropping funnel over 1 hour, and after completion of the dropwise addition, the mixture was kept at an internal temperature of 25°C for an additional 2 hours. After completion of the reaction, acetonitrile was removed using a reduced pressure evaporator and purified by column chromatography (silica gel). was used to remove the solvent to give yellow crystals. The crystals were dried at 60° C. under reduced pressure to obtain 4.6 parts of photoselective absorption compound (1) as a yellow powder. Yield was 50%.

As a result of ¹ H-NMR analysis, the following peaks were observed, confirming that photoselective 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. 09 (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 extinction coefficient ε>
In order to measure the gram extinction coefficient of the obtained photoselective absorption compound (1), the photoselective absorption compound (1) was dissolved in 2-butanone. The resulting solution (0.006 g / L) was placed in a 1 cm quartz cell, the quartz cell was set in a spectrophotometer UV-2450 (manufactured by Shimadzu Corporation), and a wavelength of 300 to 800 nm was measured in 1 nm steps by the double beam method. Absorbance was measured in the range. From the obtained absorbance value, the concentration of the light-absorbing compound in the solution, and the optical path length of the quartz cell, the gram extinction coefficient for each wavelength was calculated using the following formula.
ε(λ)=A(λ)/CL
[Wherein, ε(λ) represents the gram extinction coefficient L/(g cm) of the compound at the wavelength λ nm, A(λ) represents the absorbance at the wavelength λ nm, C represents the concentration g/L, and L represents It represents the optical path length cm of the quartz cell. ]
When the absorption maximum wavelength (λmax) of the photoselective absorption compound (1) was measured, it was λmax = 389 nm (in 2-butanone), the value of ε (405) was 47 L/(g cm), and ε The value of (440) was 0.1 L/(g·cm) or less, and the value of ε(405)/ε(440) was 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、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、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（ａａ２）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 photoselective absorption compound (2)

In a 200 mL-four-necked flask equipped with a Dimroth condenser and a thermometer, in a nitrogen atmosphere, 10 g of the compound represented by the formula (aa) synthesized with reference to JP-A-2014-194508, acetic anhydride (Wako Pure Chemical Industries, Ltd. Co., 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 and stirred with a magnetic stirrer. After 4.5 g of DIPEA (manufactured by Tokyo Chemical Industry Co., Ltd.) was added dropwise to the obtained mixture at an internal temperature of 25°C over 1 hour, the mixture was further kept at an internal temperature of 25°C for 2 hours. After that, acetonitrile is removed using a reduced pressure evaporator, purified by column chromatography (silica gel), and the effluent containing the compound represented by formula (aa2) is subjected to a reduced pressure evaporator to remove the solvent, resulting in a yellow color. crystals were obtained. By drying the crystals under reduced pressure at 60° C., 4.6 g of the compound represented by the formula (aa2) (photoselective absorption compound (2)) was obtained as a yellow powder. Yield was 56%.
When the gram absorbance coefficient is obtained by the same method as above, the value of ε(405) of the compound represented by formula (aa2) is 45 L/(g cm), and the value of ε(420) is 2.1 L/ (g·cm).

(Synthesis Example 3) Synthesis of (meth)acrylic resin 81.8 parts of ethyl acetate as a solvent and 70.4 parts of butyl acrylate as a monomer were placed in a reaction vessel equipped with a cooling tube, a nitrogen inlet tube, a thermometer and a stirrer. 20.0 parts of methyl acrylate, 8.0 parts of 2-phenoxyethyl acrylate, 1.0 parts of 2-hydroxyethyl acrylate and 0.6 parts of acrylic acid. After replacing the air in the reaction vessel with nitrogen gas, the internal temperature was adjusted to 60°C. Then, a solution of 0.12 parts of azobisisobutyronitrile dissolved in 10 parts of ethyl acetate was added. After holding at the same temperature for 1 hour, while maintaining the internal temperature at 54 to 56°C, ethyl acetate was continuously introduced into the reaction vessel at an addition rate of 17.3 parts/hour so that the concentration of the polymer was approximately 35%. added on purpose. After maintaining the internal temperature at 54 to 56° C. for 12 hours from the start of the addition of ethyl acetate, ethyl acetate was added to adjust the polymer concentration to 20%, and the (meth)acrylic resin was added. An ethyl acetate solution (1) was obtained. The (meth)acrylic resin had a weight average molecular weight Mw of 1,390,000 and a ratio Mw/Mn between the weight average molecular weight Mw and the number average molecular weight Mn of 5.32.

The weight-average molecular weight and number-average molecular weight were measured using four columns of "TSK gel XL (manufactured by Tosoh Corporation)" and one column of "Shodex GPC KF-802 (manufactured by Showa Denko Co., Ltd.)" in the GPC apparatus. A total of 5 tubes are connected in series, and tetrahydrofuran is used as the eluent, the sample concentration is 5 mg/mL, the sample introduction amount is 100 μL, the temperature is 40° C., and the flow rate is 1 mL/min. did.

(Synthesis Example 4) Synthesis of adhesive composition (1) For 100 parts of the solid content of the (meth)acrylic resin ethyl acetate solution (1) (resin concentration: 20%) obtained in Synthesis Example 3, 0.4 parts of a cross-linking agent, 0.4 parts of a silane compound, 2 parts of the photoselective absorbing compound (1) synthesized in Synthesis Example 1, and 2.0 parts of Sumisorb 350 (manufactured by Sumika Chemtex Co., Ltd.) are mixed, and Ethyl acetate was added so that the solid content concentration was 14% to obtain an adhesive composition (1). In addition, the compounding amount of the said crosslinking agent is the number of parts by weight as an active ingredient.

Details of the cross-linking agent and silane compound used in Synthesis Example 4 are as follows.
Cross-linking agent: Ethyl acetate solution of trimethylolpropane adduct of tolylene diisocyanate (solid concentration: 75%), trade name "Coronate L" obtained from Tosoh Corporation.
Silane compound: 3-glycidoxypropyltrimethoxysilane, trade name "KBM403" obtained from Shin-Etsu Chemical Co., Ltd.

(Synthesis Example 5) Synthesis of adhesive composition (2) The photoselective absorption compound (2) obtained in Synthesis Example 2 was combined with 2.0 parts of the photoselective absorption compound (2) and 2-hydroxy-4-methoxybenzophenone (Tokyo A pressure-sensitive adhesive composition (2) was obtained in the same manner as in Synthesis Example 4, except that 1.0 part was used (manufactured by Kasei Kogyo Co., Ltd.).

(Synthesis Example 6) Synthesis of adhesive composition (3) The photoselective absorption compound (2) obtained in Synthesis Example 2 and EST-5 (manufactured by Sumitomo Seika Co., Ltd.) 1.0 A pressure-sensitive adhesive composition (3) was obtained in the same manner as in Synthesis Example 4, except that parts were used.

(Synthesis Example 7) Synthesis of adhesive composition (4) Synthesis Example 4 except that only 2 parts of the photoselective absorption compound (1) obtained in Synthesis Example 1 was used as the photoselective absorption compound, and Sumisoap 350 was not mixed. A (meth)acrylic resin pressure-sensitive adhesive composition (7) was obtained in the same manner as above.

(Synthesis Example 8) Synthesis of adhesive composition (5) Synthesis Example 4 except that only 2 parts of the photoselective absorption compound (2) obtained in Synthesis Example 2 was used as the photoselective absorption compound, and Sumisoap 350 was not collapsed. A (meth)acrylic resin pressure-sensitive adhesive composition (5) was obtained in the same manner as above.

<Production of adhesive sheet>
(Example 1) Preparation of adhesive sheet (1) The obtained adhesive composition (1) was applied to a separate film made of a polyethylene terephthalate film subjected to mold release treatment [trade name "PLR" obtained from Lintec Corporation. -382190"] using an applicator so that the thickness after drying was 15 μm, and dried at 100° C. for 1 minute to prepare an adhesive layer (1).

The pressure-sensitive adhesive layer (1) thus obtained was laminated to a 23 μm cycloolefin film using a laminator, and then cured for 7 days under conditions of a temperature of 23° C. and a relative humidity of 65% to obtain a pressure-sensitive adhesive sheet (1).

(Example 2) Production of PSA sheet (2) ).

(Example 3) Preparation of adhesive sheet (3) The adhesive sheet (3) was prepared in the same manner as in Example 1 except that the adhesive composition was replaced with the adhesive composition (3) obtained in Synthesis Example 6 ).

(Comparative Example 1) Production of PSA sheet (4) ).

(Comparative Example 2) Production of PSA sheet (5) ).

<Preparation of polarizing plate with adhesive>
(Production Example 1) Preparation of polarizing plate film Polyvinyl alcohol film having an average degree of polymerization of about 2400, a degree of saponification of 99.9 mol%, and a thickness of 30 µm [trade name "Kuraray Vinylon VF-PE#3000" manufactured by Kuraray Co., Ltd.] was immersed in pure water at 37°C, and then immersed in an aqueous solution containing iodine and potassium iodide (iodine/potassium iodide/water (mass ratio) = 0.04/1.5/100) at 30°C. . After that, it was immersed in an aqueous solution containing potassium iodide and boric acid (potassium iodide/boric acid/water (mass ratio)=12/3.6/100) at 56.5°C. After the film was washed with pure water at 10° C., it was dried at 85° C. to obtain a polarizer having a thickness of about 12 μm in which iodine was adsorbed and oriented in polyvinyl alcohol. The stretching was mainly performed in the steps of iodine dyeing and boric acid treatment, and the total stretching ratio was 5.3 times.
On one side of the obtained polarizer, a transparent protective film made of triacetyl cellulose film with a thickness of 25 μm [trade name “KC2UA” manufactured by Konica Minolta Opto Co., Ltd.; They were laminated via an adhesive made of an aqueous solution of a system resin. Next, a zero retardation film made of a cyclic polyolefin resin having a thickness of 23 μm [trade name “ZEONOR” manufactured by Nippon Zeon Co., Ltd., hereinafter “COP film”) was applied to the surface of the polarizer opposite to the triacetyl cellulose film. A polarizing plate was produced by laminating these materials via an adhesive made of an aqueous solution of a polyvinyl alcohol-based resin.

(Example 4) Preparation of adhesive-attached polarizing plate (1) The adhesive-attached polarizing plate (1) was prepared in the same manner as in Example 2, except that the 23 µm cycloolefin film was replaced with the polarizing plate obtained in Production Example 1. ). The adhesive layer-attached polarizing plate (1) has a structure of TAC film/adhesive layer/polarizing film/adhesive layer/COP film/adhesive layer.

(Example 5) Production of adhesive-attached polarizing plate (2) The adhesive-attached polarizing plate (2) was prepared in the same manner as in Example 3, except that the 23 µm cycloolefin film was replaced with the polarizing plate obtained in Production Example 1. ). The adhesive layer-attached polarizing plate (2) has a structure of TAC film/adhesive layer/polarizing film/adhesive layer/COP film/adhesive layer.

(Comparative Example 3) Preparation of adhesive-attached polarizing plate (3) The adhesive-attached polarizing plate (3) was prepared in the same manner as in Comparative Example 2, except that the 23 µm cycloolefin film was replaced with the polarizing plate obtained in Production Example 1. ). The adhesive layer-attached polarizing plate (3) has a structure of TAC film/adhesive layer/polarizing film/adhesive layer/COP film/adhesive layer.

<Measurement of Absorbance of Adhesive Sheet>
The resulting adhesive sheet-attached film (1) was cut into a size of 30 mm x 30 mm, and the adhesive sheet and alkali-free glass (trade name "EAGLE XG" manufactured by Corning Incorporated) were pasted together, and this was used as a sample. and The absorbance of the prepared sample in a wavelength range of 300 to 800 nm was measured using a spectrophotometer (UV-2450: manufactured by Shimadzu Corporation). Table 1 shows the results. The higher the absorbance retention, the better the weather resistance without deterioration of the selective light absorption function. The absorbance at wavelengths of 350 nm, 405 nm, and 440 nm was 0 for both the COP film alone and the alkali-free glass alone.

After the absorbance measurement, the sample was placed in a Sunshine Weather Meter (manufactured by Suga Test Instruments Co., Ltd.) for 24 hours under conditions of 63° C. and 50% relative humidity to conduct a weather resistance test for 24 hours. The absorbance of the removed sample was measured in the same manner as above. Based on the measured absorbance, the absorbance retention rate of the sample at 350 nm and 405 nm was calculated according to the following formula. Table 1 shows the results.
Absorbance retention = (A (405) after durability test/A (405) before durability test) x 100
Absorbance retention = (A (350) after durability test/A (350) before durability test) x 100

<Measurement of absorbance of polarizing plate with adhesive>
After cutting the obtained polarizing plate with adhesive to a size of 30 mm×30 mm, the adhesive layer was attached to a glass substrate to obtain a measurement sample. The layer structure of the measurement sample was glass substrate/adhesive layer/COP film/adhesive layer/polarizer/adhesive layer/TAC film. A non-alkali glass substrate (trade name “Eagle XG” manufactured by Corning Incorporated) was used as the glass substrate.
For the obtained measurement sample, a spectrophotometer with an integrating sphere (manufactured by JASCO Corporation, product name "V7100") was used to determine the transmission spectrum in the transmission axis direction and the absorption axis direction of the polarizing plate in the wavelength range of 380 to 780 nm. was measured, and the absorbance of the pressure-sensitive adhesive layer-attached polarizing plate was calculated from the transmission spectrum of the transmission axis of the polarizing plate. In addition, it was confirmed that the polarizing plate with an adhesive suppresses deterioration in visible light having a short wavelength of 405 nm. Further, the absorbance at wavelengths of 405 nm and 440 nm was 0 for all of the TAC film alone, the COP film alone, and the alkali-free glass alone.

As shown in Table 1, the pressure-sensitive adhesive sheet of the present invention has a good light absorption function around a wavelength of 350 nm and a good light absorption function around a wavelength of 405 nm. Therefore, when the pressure-sensitive adhesive sheet of the present invention is laminated on a retardation film or an organic EL device, the pressure-sensitive adhesive sheet of the present invention absorbs ultraviolet rays and short-wavelength visible light around 405 nm, resulting in a retardation film or an organic EL device. UV rays and light with a wavelength of about 405 nm can be blocked, and deterioration of the retardation film and the organic EL element from both UV rays and short-wavelength visible light can be suppressed.
The pressure-sensitive adhesive sheet of the present invention has a good light absorption function (good absorbance retention rate) at wavelengths around 350 nm and around 405 nm even after a weather resistance test, and has good weather resistance (durability). Therefore, the pressure-sensitive adhesive sheet of the present invention can maintain the function of suppressing deterioration of the retardation film or the organic EL element due to ultraviolet light and short-wavelength visible light. In addition, the pressure-sensitive adhesive sheet of the present invention has low light absorption performance in the vicinity of a wavelength of 440 nm, does not interfere with light emission of a liquid crystal display device, and can achieve good color expression.
Moreover, as shown in Table 2, the optical film with an adhesive sheet of the present invention also has a good light absorption function at a wavelength of around 405 nm. Furthermore, even after the weather resistance test, the light absorption function is good in the vicinity of the wavelength of 405 nm, and it has good weather resistance (durability).

The pressure-sensitive adhesive sheet and the pressure-sensitive adhesive sheet-attached optical film of the present invention are suitably used for liquid crystal panels and liquid crystal display devices.

1 adhesive sheet 2 release film 10A, 10B, 10C optical laminate 3 protective film 4 optical film 7, 60 adhesive layer 7a adhesive layer 8 protective film 9 polarizing film 30 light emitting element 40 optical film 50, 50a quarter wavelength Retardation layer 60 Adhesive layer 70 Half-wave retardation layer 80 Positive C layer 100 Polarizing plate

Claims (10)

A pressure-sensitive adhesive sheet formed from a pressure-sensitive adhesive composition containing a (meth)acrylic resin (A) and a photoselective absorption compound, satisfying the following formulas (1), (2) and (3),
The photoselective absorption compound includes a compound that selectively absorbs light with a wavelength of 350 nm and a compound that selectively absorbs light with a wavelength of 405 nm,
The pressure-sensitive adhesive sheet, wherein the compound that selectively absorbs light with a wavelength of 405 nm is a compound represented by the following formula (I).
A(350)≧0.5 (1)
A(405)≧0.5 (2)
A(440)≦0.1 (3)
[In formula (1), A(350) represents absorbance at a wavelength of 350 nm.
In formula (2), A(405) represents absorbance at a wavelength of 405 nm.
In formula (3), A(440) represents absorbance at a wavelength of 440 nm. ]

[In formula (I), R ¹ and R ⁵ are each independently a hydrogen atom, an optionally substituted alkyl group having 1 to 25 carbon atoms, an optionally substituted carbon represents an aralkyl group having 7 to 15 carbon atoms, an aryl group having 6 to 15 carbon atoms or a heterocyclic group, and —CH ₂ — contained in the alkyl group or aralkyl group is —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 are each independently a hydrogen atom, an optionally substituted C 1-6 alkyl group, an optionally substituted aromatic hydrocarbon group or an optionally substituted aromatic heterocyclic group, and -CH ₂ - contained in the alkyl group is -NR ^1B -, -CO-, -SO ₂ -, -O- or -S- may be substituted with
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 linked together to form a ring structure .
R ¹ and R ² may be linked together to form a ring structure, R ² and R ³ may be linked together to form a ring structure, R ² and R ⁴ may be linked together to form a ring structure and R ³ and R ⁶ may be linked together to form a ring structure. ] The pressure-sensitive adhesive sheet according to claim 1, further satisfying the following formula (4).
A(405)/A(440)≧5 (4)
[In formula (4), A(405) represents absorbance at a wavelength of 405 nm, and A(440) represents absorbance at a wavelength of 440 nm. ] 2. The pressure-sensitive adhesive sheet according to claim 1, wherein the compound that selectively absorbs light with a wavelength of 405 nm is a compound that satisfies formula (5).
ε(405)≧20 (5)
[In formula (5), ε(405) represents the gram extinction coefficient of the compound at a wavelength of 405 nm. The unit of gram extinction coefficient is L/(g·cm). ] 4. The pressure-sensitive adhesive sheet according to claim 3 , wherein the compound that selectively absorbs light with a wavelength of 405 nm is a compound that satisfies formula (6).
ε(405)/ε(440)≧20 (6)
[In formula (6), ε(405) represents the gram extinction coefficient of the compound at a wavelength of 405 nm, and ε(440) represents the gram extinction coefficient at a wavelength of 440 nm. ] The pressure-sensitive adhesive sheet according to any one of claims 1 to 4 , wherein the pressure-sensitive adhesive composition further contains a cross-linking agent (B). The pressure-sensitive adhesive sheet according to claim 5 , wherein the content of the cross-linking agent (B) is 0.01 to 15 parts by mass with respect to 100 parts by mass of the (meth)acrylic resin (A). 7. The adhesive sheet according to any one of claims 1 to 6 , wherein the content of the photoselective absorption compound is 0.01 to 20 parts by mass with respect to 100 parts by mass of the (meth)acrylic resin (A). The optical film with an adhesive layer according to any one of claims 1 to 7 , which is obtained by laminating an optical film on at least one surface of an adhesive sheet. The optical film with an adhesive layer according to claim 8 , wherein the optical film is a polarizing plate. A display device comprising the pressure-sensitive adhesive- attached optical film according to claim 8 .

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