JP2021127353A - Photocurable adhesive composition for optical film, photocurable adhesive layer for optical film, optical member, and image display apparatus - Google Patents

Abstract

To provide means to give an adhesive layer that has good step-filling properties, durability under harsh conditions (high temperature, high humidity, thermal shock), good haze after moist heat durability testing, and good processability and adhesive strength, and allows reduction in permittivity.SOLUTION: A photocurable adhesive composition for optical films includes a main component (A) and a chain transfer agent (B). The main component (A) includes a (meth)acrylate copolymer (a) having a particular structure, and the content of the chain transfer agent (B) is 0.01 pts.mass or more to 5 pts.mass or less relative to 100 pts.mass of the main component (A).SELECTED DRAWING: None

Description

The present invention relates to an adhesive composition for a photocurable optical film, an adhesive layer for a photocurable optical film, an optical member, and an image display device.

Currently, liquid crystal display panels (LCDs) and organic EL display panels are mainly used as display panels. Generally, a laminate in which a plurality of films are laminated is bonded to the surface of a display panel. For example, in an LCD, an optical film such as a polarizing plate, a retardation plate, a viewing angle expanding film, and a brightness improving film is laminated on the surface of a liquid crystal panel. Each layer constituting the display panel is bonded to each other via an adhesive layer formed by various adhesives.

On the other hand, in recent years, in mobile displays represented by smartphones, irregular shape processing such as curved surface processing, dent processing, and drilling processing of edge portions has become mainstream.

The optical film laminate laminated by the optical film, the pressure-sensitive adhesive layer, or the adhesive layer is subjected to the above-mentioned irregular shape processing, but is processed beyond the processability required for the conventional optical film or optical film laminate. Characteristics are required. Especially for the adhesive layer, good processing that the adhesive is not damaged by heat or the adhesive layer is peeled off and the edges are not disturbed by the friction caused by spindle processing and the stress at the time of scraping. Sex is required.

Further, in addition to workability, it is required that the optical characteristics required for the adhesive for an optical film and various durability test conditions do not cause peeling or floating even if the adhesive is held for a long time.

Further, in recent years, in the field of optical devices centering on mobile phones and mobile terminals, thinning and weight reduction have progressed, and new problems have arisen accordingly. That is, in an optical device equipped with a touch sensor function, particularly a popular capacitance type touch function, the capacitance of a capacitor formed between two electrodes facing each other via an insulating film is a surface protection panel. The position was detected by the conductor such as a finger approaching from the side and changing. However, as the thickness of the member becomes thinner, the distance between the electrode and the surface of the protective panel becomes narrower, and when the change in capacitance in response to touch becomes large, there is a problem that noise is likely to be generated in the detection signal.

In addition, not only the weight and thickness of the members are reduced, but also the gaps between the members are narrowed, so that the filling member used for integrating the members such as the adhesive sheet is also required to be further thinned. Therefore, the pressure-sensitive adhesive sheet used for filling between the electrode and the surface protection panel needs to have a low dielectric constant in order to absorb the change in the touch detection sensitivity due to the thinning of the member or itself.

With the weight reduction and cost reduction of electrodes, the electrode substrate is being replaced from glass to resin film. In the case of an electrode in which a conductive thin film is patterned on only one side, it is necessary to laminate two film electrodes with each other or a glass electrode and a film electrode via an adhesive sheet or the like. It is required to have a characteristic of low relative permittivity.

Further, in order to impart cosmeticity to the cover glass and the cover plastic film, a black or white printing process is applied to the side on which the optical adhesive layer is arranged. Since the printed portion needs to have a concealing property, a printing ink layer having a certain thickness or more is formed. When the cover glass or cover plastic film is bonded to the optical adhesive layer, it is necessary to bond the optical adhesive layer to the step of the printing ink layer without any gaps. Therefore, the optical pressure-sensitive adhesive layer is required to have a characteristic (step followability) of following the step of the printing ink layer.

Examples of the pressure-sensitive adhesive (or adhesive) for an optical film, the pressure-sensitive adhesive layer for an optical film, and the laminate include the techniques proposed in Patent Documents 1 and 2.

Japanese Unexamined Patent Publication No. 2017-125195 Japanese Patent Application Laid-Open No. 2015-524011

The present invention has been made in view of the above circumstances. That is, it has good step followability, durability in harsh environments (high temperature, high humidity, heat shock), excellent haze after wet heat durability test, excellent workability and adhesive strength, and even lower. It is an object of the present invention to provide a means for obtaining a pressure-sensitive adhesive layer capable of making a dielectric constant.

The present inventors have conducted diligent research to solve the above problems. As a result, they have found that a pressure-sensitive adhesive composition having the following constitution solves the above-mentioned problems, and have completed the present invention.

That is, the pressure-sensitive adhesive composition for a photocurable optical film according to one embodiment of the present invention contains a main agent (A) and a chain transfer agent (B), and the main agent (A) has a (meth) acrylic acid ester copolymer weight. The (meth) acrylic acid ester copolymer (a) containing the coalescence (a) is
(A1): A structural unit derived from a (meth) acrylic acid ester monomer having a linear or branched alkyl group having 1 to 14 carbon atoms and 15% by mass or more and 55% by mass or less.
(A2): A structural unit derived from a (meth) acrylic acid ester monomer having a cyclic alkyl group having 3 or more and 14 or less carbon atoms, which is 10% by mass or more and 55% by mass or less.
(A3): A constituent unit derived from a hydroxy group-containing (meth) acrylic acid ester monomer, 5% by mass or more and 35% by mass or less.
(A4) A structural unit derived from an amide group-containing monomer 5% by mass or more and 35% by mass or less.
(However, the total amount of the structural units derived from (a1) to (a4) is 100% by mass, and the content of the structural units derived from (a1) is derived from the structural units derived from (a1) and (a2). 20% by mass or more and 60% by mass or less with respect to the total amount with the constituent units)
Including
The content of the chain transfer agent (B) is 0.01 part by mass or more and 5 parts by mass or less with respect to 100 parts by mass of the main agent (A).

According to the present invention, it has good step followability, durability in a harsh environment (high temperature, high humidity, heat shock), excellent haze after a wet heat durability test, and excellent workability and adhesive strength. A means for obtaining a pressure-sensitive adhesive layer which is excellent and can have a low dielectric constant can be provided.

It is sectional drawing which shows the structure of a thin polarizing plate.

Hereinafter, embodiments of the present invention will be described, but the technical scope of the present invention should be determined based on the description of the scope of claims, and is not limited to the following embodiments. Unless otherwise specified, in the present specification, operations and physical properties are measured under the conditions of room temperature (20 ° C. or higher and 25 ° C. or lower) / relative humidity of 40% RH or more and 50% RH or less. In addition, in this specification, "(meth) acrylic" is a general term of acrylic and methacryl. Further, in the present specification, the "(co) polymer" refers to a homopolymer in which a single monomer is polymerized and a copolymer in which a plurality of types of monomers are polymerized. It is a generic term.

<Adhesive composition for photocurable optical film>
The pressure-sensitive adhesive composition for a photocurable optical film according to one embodiment of the present invention (also simply referred to as “sticky composition”) is for a photocurable optical film containing a main agent (A) and a chain transfer agent (B). In the pressure-sensitive adhesive composition, the main agent (A) contains a (meth) acrylic acid ester copolymer (a), and the (meth) acrylic acid ester copolymer (a) is a pressure-sensitive adhesive composition.
(A1): A structural unit derived from a (meth) acrylic acid ester monomer having a linear or branched alkyl group having 1 to 14 carbon atoms and 15% by mass or more and 55% by mass or less.
(A2): A structural unit derived from a (meth) acrylic acid ester monomer having a cyclic alkyl group having 3 or more and 14 or less carbon atoms, which is 10% by mass or more and 55% by mass or less.
(A3): A constituent unit derived from a hydroxy group-containing (meth) acrylic acid ester monomer, 5% by mass or more and 35% by mass or less.
(A4) A structural unit derived from an amide group-containing monomer 5% by mass or more and 35% by mass or less.
(However, the total amount of the structural units derived from (a1) to (a4) is 100% by mass, and the content of the structural units derived from (a1) is derived from the structural units derived from (a1) and (a2). 20% by mass or more and 60% by mass or less with respect to the total amount with the constituent units)
Including
The content of the chain transfer agent (B) is 0.01 part by mass or more and 5 parts by mass or less with respect to 100 parts by mass of the main agent (A), which is a pressure-sensitive adhesive composition for a photocurable optical film.

[Main agent (A)]
The pressure-sensitive adhesive composition according to the present invention contains a main agent (A), and the main agent (A) is a (meth) acrylic acid ester copolymer (a) (hereinafter, also simply referred to as “copolymer (a)”). Mandatory include.

<(Meta) acrylic acid ester copolymer (a)>
The copolymer (a) contains the following structural units derived from the monomers (a1) to (a4).

(A1): Structural unit derived from a (meth) acrylic acid ester monomer having a linear or branched alkyl group having 1 or more and 14 or less carbon atoms (a2): 3 by mass or less. Constituent unit derived from (meth) acrylic acid ester monomer having 14 or less cyclic alkyl groups 10% by mass or more and 55% by mass or less (a3): Constituent unit derived from (meth) acrylic acid ester monomer having hydroxy group 5% by mass % Or more and 35% by mass or less (a4) Structural unit derived from a monomer having an amide group 5% by mass or more and 35% by mass or less However, the total amount of the structural units derived from the above (a1) to (a4) is 100% by mass. The content of the structural unit derived from (a1) is 20% by mass or more and 60% by mass or less with respect to the total amount of the structural unit derived from (a1) and the structural unit derived from (a2).

These (a1) to (a4) components are monomers having one (meth) acryloyl group in the molecule. A monomer having two or more (meth) acryloyl groups in the molecule is classified into a cross-linking agent (C), which is different from the components (a1) to (a4) and further different from the component (a5) described later.

Hereinafter, the components (a1) to (a4) will be described.

(A (meth) acrylic acid ester monomer (a1) having a linear or branched alkyl group having 1 or more and 14 or less carbon atoms)
The copolymer (a) is a (meth) acrylic acid ester monomer (a1) having a linear or branched alkyl group having 1 or more and 14 or less carbon atoms (hereinafter, also referred to as “component (a1)”). ) Derived constituent units are included. In the pressure-sensitive adhesive layer and its cured product, the structural unit derived from the component (a1) functions as the basic skeleton of the polymer. The component (a1) can be used alone or in combination of two or more. Further, as the component (a1), a commercially available product or a synthetic product may be used.

The component (a1) is typically represented by the following formula (1).

In the above formula (1), R ¹ represents a hydrogen atom or a methyl group, and R ² is an alkyl group having 1 or more carbon atoms and 14 or less carbon atoms.

Examples of the linear or branched alkyl group having 1 to 14 carbon atoms include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, and a tert-butyl group. Group, n-pentyl group, isopentyl group, neopentyl group, tert-pentyl group, 2-methylbutyl group, n-hexyl group, isohexyl group, 3-methylpentyl group, ethylbutyl group, n-heptyl group, 2-methylhexyl group , N-octyl group, isooctyl group, tert-octyl group, 2-ethylhexyl group, 3-methylheptyl group, n-nonyl group, isononyl group, 1-methyloctyl group, ethylheptyl group, n-decyl group, 1- Examples thereof include a methylnonyl group, an n-undecyl group, a 1,1-dimethylnonyl group, an n-dodecyl group, an n-tridecyl group, an n-tetradecyl group, and the like. Of these, an n-butyl group, a 2-ethylhexyl group, and an n-dodecyl group are preferable from the viewpoint of ensuring adhesiveness and basic properties.

More specifically, the component (a1) includes methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate, and isobutyl (meth) acrylate. , Tert-butyl (meth) acrylate, n-pentyl (meth) acrylate, isopentyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, n-hexyl (meth) acrylate, n-heptyl (meth) acrylate, n-octyl Examples thereof include (meth) acrylate, n-nonyl (meth) acrylate, n-decyl (meth) acrylate, n-dodecyl (meth) acrylate (n-lauryl (meth) acrylate) and the like. Of these, n-butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, and n-dodecyl acrylate (n-lauryl acrylate) are preferable from the viewpoint of ensuring adhesive strength and low dielectric constant.

The content of the structural unit derived from the component (a1) in the copolymer (a) is 15% by mass or more and 55% by mass or less, assuming that the total amount of the components (a1) to (a4) is 100% by mass. When the constituent unit derived from the component (a1) is less than 15% by mass, the glass transition temperature of the copolymer (a) rises, and the step followability and durability decrease. On the other hand, if it exceeds 55% by mass, the water absorption under moist heat conditions is lowered, and the haze after the moist heat durability test is deteriorated. The content of the structural unit derived from the component (a1) is preferably 20% by mass or more and 50% by mass or less, and more preferably 30% by mass or more and 40% by mass or less.

Further, the content of the structural unit derived from the component (a1) is 20 with respect to the content of the structural unit derived from (a1) with respect to the total amount of the structural unit derived from (a1) and the structural unit derived from (a2). It is mass% or more and 60 mass% or less. If the content is less than 20% by mass, the adhesive strength is lowered and the workability is deteriorated. On the other hand, if it exceeds 60% by mass, the pressure-sensitive adhesive layer becomes too soft and the processability deteriorates.

(A (meth) acrylic acid ester monomer (a2) having a cyclic alkyl group having 3 or more and 14 or less carbon atoms)
The copolymer (a) contains a structural unit derived from a (meth) acrylic acid ester monomer (a2) having a cyclic alkyl group having 3 or more and 14 or less carbon atoms (hereinafter, also referred to as “component (a2)”). .. In the pressure-sensitive adhesive layer and its cured product, the structural unit derived from the component (a2) plays a role of ensuring the pressure-sensitive adhesive property, ensuring the durability, and ensuring the low dielectric constant.

The component (a2) can be used alone or in combination of two or more. Further, as the component (a2), a commercially available product or a synthetic product may be used.

Examples of the cyclic alkyl group having 3 to 14 carbon atoms include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, a 2-cyclopropylethyl group, and a 2-cyclobutylethyl group. , 2-Cyclopentylethyl group, Cyclohexylmethyl group, 2-Cyclohexylethyl group, Cycloheptylmethyl group, 2-Cyclooctylethyl group, 3-Methylcyclohexyl group, 4-Methylcyclohexyl group, 4-Ethylcyclohexyl group, 2-Methyl Cyclooctyl group, 3- (3-methylcyclohexyl) propyl group, 2- (4-methylcyclohexyl) ethyl group, 2- (4-ethylcyclohexyl) ethyl group, 2- (2-methylcyclooctyl) ethyl group, deca Examples thereof include a hydronaphthyl group, an adamantyl group, a dicyclopentanyl group and an isobornyl group. Of these, a cyclohexyl group and an isobornyl group are preferable from the viewpoint of ensuring durability and low dielectric constant.

More specific examples of the component (a2) include cyclopentyl (meth) acrylate, cyclohexyl (meth) acrylate, isobornyl (meth) acrylate, dicyclopentanyl (meth) acrylate, and adamantyl (meth) acrylate. Among these, isobornyl (meth) acrylate and cyclohexyl (meth) acrylate are preferable from the viewpoint of ensuring durability and low dielectric constant. More preferably, it is isobornyl (meth) acrylate or cyclohexyl (meth) acrylate.

The content of the structural unit derived from the component (a2) in the copolymer (a) is 10% by mass or more and 55% by mass or less, assuming that the total amount of the components (a1) to (a4) is 100% by mass. (A2) If the content of the constituent unit derived from the component is less than 15% by mass, the durability is deteriorated. On the other hand, when it exceeds 55% by mass), the glass transition temperature of the copolymer (a) rises, and the step followability and durability decrease. The content of the constituent unit derived from the component (a2) is preferably 15% by mass or more and 50% by mass or less, and more preferably 20% by mass or more and 45% by mass or less.

(A (meth) acrylic acid ester monomer having a hydroxy group (a3))
The copolymer (a) contains a structural unit derived from a (meth) acrylic acid ester monomer (a3) having a hydroxy group (hereinafter, also referred to as “component (a3)”). The structural unit derived from the (meth) acrylic acid ester monomer (a3) having a hydroxy group has hydrophilicity. Therefore, in the pressure-sensitive adhesive layer and its cured product, the water retention performance of the polymer can be improved and dew condensation can be prevented. The component (a3) can be used alone or in combination of two or more. Further, as the component (a3), a commercially available product or a synthetic product may be used.

The component (a3) is typically represented by the following formula (2).

In formula (2), R ³ represents a hydrogen atom or a methyl group, and R ⁴ represents a divalent organic group.

The divalent organic group is not particularly limited, but is preferably an alkylene group having 1 or more and 10 or less carbon atoms from the viewpoint of improving water absorption under moist heat conditions and improving haze after the moist heat durability test. , More preferably an alkylene group having 2 or more and 6 or less carbon atoms.

Examples of the alkylene group having 1 or more and 10 or less carbon atoms include a methylene group (-CH _2- ), an ethylene group (-CH ₂ CH _2- ), a trimethylene group (-CH ₂ CH ₂ CH _2- ), and a tetramethylene group. (-CH ₂ CH ₂ CH ₂ CH _2- ), propylene group (-CH (CH ₃ ) CH _2- ), pentamethylene group, hexamethylene group, heptamethylene group, octamethylene group, 2-ethylhexamethylene group (-CH 2 CH 2 CH 2 CH 2-) -CH ₂ CH (CH ₂ CH ₃ ) CH ₂ CH ₂ CH ₂ CH _2- ), nonamethylene group, decamethylene group and the like can be mentioned. Of these, an ethylene group and a tetramethylene group are preferable from the viewpoint of further improving the haze after the wet heat durability test.

More specifically, the component (a3) includes 4-hydroxybutyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, hydroxymethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 1,4. -Cyclohexanedimethanol monoacrylate and the like. Of these, 4-hydroxybutyl (meth) acrylate and 2-hydroxyethyl (meth) acrylate are preferable from the viewpoint of further improving the haze after the moist heat endurance test.

The content of the structural unit derived from the component (a3) in the copolymer (a) is 5% by mass or more and 35% by mass or less, assuming that the total amount of the components (a1) to (a4) is 100% by mass. If the content derived from the component (a3) is less than 5% by mass, the haze after the wet heat durability test is lowered. On the other hand, if it exceeds 35% by mass, the moist heat durability and the step followability are lowered. The content of the structural unit derived from the component (a3) is preferably 7% by mass or more and 30% by mass or less, and more preferably 10% by mass or more and 25% by mass or less.

((Meta) acrylic monomer having an amide group)
The copolymer (a) contains a structural unit derived from a (meth) acrylic monomer (a4) having an amide group (hereinafter, also referred to as “component (a4)”). The structural unit derived from the component (a4) has hydrophilicity. Therefore, in the pressure-sensitive adhesive layer and its cured product, the water retention performance of the polymer can be improved and dew condensation can be prevented. The component (a4) can be used alone or in combination of two or more. Further, as the component (a4), a commercially available product or a synthetic product may be used.

The component (a4) is typically represented by the following formula (3).

In formula (3), R ⁵ represents a hydrogen atom or a methyl group, R ⁶ represents a divalent organic group or a single bond, R ⁷ represents a hydrogen atom or a hydroxy group, and R ⁸ represents hydrogen. Represents an atom or an alkyl group having 1 or more and 10 or less carbon atoms.

The divalent organic group is not particularly limited, but is preferably an alkylene group having 1 or more and 10 or less carbon atoms, and more preferably 2 or more and 6 or less carbon atoms, from the viewpoint of further improving the haze after the wet heat durability test. It is an alkylene group.

Examples of the alkylene group having 1 or more and 10 or less carbon atoms include the same groups as those described in the formula (2). Of these, an ethylene group is preferable from the viewpoint of further improving the haze after the moist heat endurance test.

Examples of the alkyl group having 1 or more and 10 or less carbon atoms include a group similar to that described in the formula (2). Of these, an ethyl group is preferable from the viewpoint of further improving the haze after the moist heat endurance test.

In addition, R ₇ and R ₈ may form a ring with each other.

Specific examples of the (meth) acrylic monomer having an amide group include N-hydroxymethyl (meth) acrylamide, N-hydroxyethyl (meth) acrylamide, N- (meth) acryloylmorpholin, and N, N-dimethyl (meth). ) Acrylamide, N, N-diethyl (meth) acrylamide, (meth) acrylamide, N-isopropyl (meth) acrylamide, N-t-butyl (meth) acrylamide and the like. Of these, N- (meth) acryloyl morpholine and N-hydroxyethyl (meth) acrylamide are preferable from the viewpoint of ensuring durability and further improving haze after the wet heat durability test. These can be used alone or in combination of two or more. Further, as the component (a4), a commercially available product or a synthetic product may be used.

The content of the structural unit derived from the component (a4) in the copolymer (a) is 5% by mass or more and 35% by mass or less, assuming that the total amount of the components (a1) to (a4) is 100% by mass. If the content derived from the component (a3) is less than 5% by mass, the haze after the wet heat durability test is lowered. On the other hand, if it exceeds 35% by mass, the moist heat durability and the step followability are lowered. The content of the structural unit derived from the component (a4) is preferably 7% by mass or more and 30% by mass or less, and more preferably 10% by mass or more and 25% by mass or less.

((Meta) acrylic acid ester monomer (a5) having one radically polymerizable functional group other than the component (a1), the component (a2), the component (a3), and the component (a4))
The copolymer (a) is derived from a (meth) acrylic acid ester monomer (a5) having one radically polymerizable functional group other than the components (a1) to (a4) (hereinafter, also referred to as “component (a5)”). It is preferable to have more structural units of. In the pressure-sensitive adhesive layer and its cured product, the structural unit derived from the component (a5) has an effect of lowering the dielectric constant of the polymer. The component (a5) can be used alone or in combination of two or more. Further, as the component (a5), a commercially available product or a synthetic product may be used.

Examples of the component (a5) include a (meth) acrylic acid ester monomer having an aromatic hydrocarbon group, a (meth) acrylic acid ester monomer having a branched alkyl group having 18 or more and 36 or less carbon atoms, and an alkoxyalkyl. Examples thereof include (meth) acrylic acid ester monomers having a group or an alkylene oxide group.

The (meth) acrylic acid ester monomer having an aromatic hydrocarbon group is typically represented by the following formula (4).

In formula (4), R ⁹ represents a hydrogen atom or a methyl group, and R ¹⁰ represents an aromatic hydrocarbon group.

The aromatic hydrocarbon group is not particularly limited, but an aromatic hydrocarbon group having 6 to 20 carbon atoms is preferable, and for example, a group having a benzene ring such as a phenyl group or a benzylphenyl group, a group having a naphthalene ring, or biphenyl. Examples include a group having a ring.

Specific examples of the (meth) acrylic acid ester monomer having an aromatic hydrocarbon group include benzyl (meth) acrylate, phenyl (meth) acrylate, benzylphenyl (meth) acrylate, and o-phenylphenol (meth) acrylate. Phenoxy (meth) acrylate, pt-butylphenyl (meth) acrylate, phenoxyethyl (meth) acrylate, phenoxypropyl (meth) acrylate, phenoxydiethylene glycol (meth) acrylate, ethylene oxide-modified nonylphenol (meth) acrylate, ethylene oxide-modified cresol ( Meta) acrylate, phenolethylene oxide modified (meth) acrylate, 2-hydroxy-3-phenoxypropyl (meth) acrylate, methoxybenzyl (meth) acrylate, chlorobenzyl (meth) acrylate, cresyl (meth) acrylate, polystyryl (meth) acrylate Those having a benzene ring such as; Naphthalene such as hydroxyethylated β-naphthol acrylate, 2-naphthoethyl (meth) acrylate, 2-naphthoxyethyl acrylate, 2- (4-methoxy-1-naphthoxy) ethyl (meth) acrylate. Those having a ring; those having a biphenyl ring such as biphenyl (meth) acrylate can be mentioned.

Among these, benzyl (meth) acrylate is preferable from the viewpoint of ensuring durability and low dielectric constant.

Specific examples of the (meth) acrylic acid ester monomer having a branched-chain alkyl group having 18 or more and 36 or less carbon atoms include isosetyl stearate, isostearyl stearate, and 2-decyltetradecanyl (meth). Examples include acrylate.

Examples of (meth) acrylate monomers having an alkoxyalkyl group or an alkylene oxide group include methoxyethyl (meth) acrylate, ethoxymethyl (meth) acrylate, ethoxyethyl (meth) acrylate, propoxyethyl (meth) acrylate, and butoxy. Ethyl (meth) acrylate, methoxypropyl (meth) acrylate, methoxybutyl (meth) acrylate; ethoxy-diethylene glycol (meth) acrylate, ethoxy-triethylene glycol (meth) acrylate, methoxy-triethylene glycol (meth) acrylate, methoxy- Diethylene glycol (meth) acrylate, propoxy-diethylene glycol (meth) acrylate, methoxy-triethylene glycol (meth) acrylate, 2-ethylhexyl-diglycol (meth) acrylate (2-ethylhexyloxy-diethylene glycol (meth) acrylate), methoxy-polyethylene Glycol (meth) acrylate (n = 4-10), methoxydipropylene glycol (meth) acrylate, 2-ethylhexyl-diglycol acrylate and the like can be mentioned.

Among these, isostearyl stearate, 2-decyltetradecanyl (meth) acrylate, and 2-ethylhexyl-diglycol (meth) acrylate are preferable from the viewpoint of ensuring low dielectric constant.

The content of the structural unit derived from the component (a5) in the copolymer (a) is 8 parts by mass or more and 45 parts by mass with respect to the total amount of 100 parts by mass of the structural units derived from the components (a1) to (a4). It is preferably 10 parts by mass or more and 40 parts by mass or less. Within this range, it is excellent in adhesiveness, low dielectric property, and durability.

[Form of main agent (A)]
The main agent (A) of the present invention may be in the form of only the copolymer (a), or may be in the form of a so-called polymer syrup containing the copolymer (a) and an unreacted monomer. .. However, from the viewpoints of ease of formation of the pressure-sensitive adhesive layer according to the present invention, more efficient performance of the desired effect of the present invention, and the like, the copolymer (a) and the unreacted monomer ( It is preferably in the form of a polymer syrup containing the above-mentioned components (a1) to (a4) (monomers of the component (a5) if necessary). Hereinafter, a production method for obtaining a polymer syrup will be described.

The method for producing the copolymer (a) is not particularly limited, and is a solution polymerization method using a polymerization initiator, a massive polymerization method, an emulsion polymerization method, a suspension polymerization method, a reverse phase suspension polymerization method, and a thin film polymerization method. , Conventionally known methods such as a spray polymerization method can be used. Examples of the polymerization control method include an adiabatic polymerization method, a temperature control polymerization method, and an isothermal polymerization method. As the polymerization initiator, either a thermal polymerization initiator or a photopolymerization initiator may be used. In addition to or in addition to the method of initiating the polymerization with a polymerization initiator, a method of initiating the polymerization by irradiating an active energy ray such as radiation, an electron beam, or an ultraviolet ray can also be adopted. Above all, the massive polymerization method using a photopolymerization initiator is more preferable because the molecular weight can be easily adjusted and impurities can be reduced.

The bulk polymerization method using the photopolymerization initiator is not particularly limited, but for example, the raw material monomer of the copolymer (a) and the photopolymerization initiator are added, and the reaction start temperature is set to 20 ° C. under a nitrogen atmosphere. Irradiate the active energy rays at 35 ° C. or higher. When the temperature in the reaction system rises from the reaction start temperature to 5 ° C. or higher and 15 ° C. or lower, the reaction is stopped by introducing air into the reaction system to obtain the copolymer (a). .. At this time, it is not necessary to react all the raw material monomers used, and the reaction may be stopped when the desired weight average molecular weight is reached. Since the components (a1) to (a5), which are unreacted raw material monomers, serve as a solvent for dissolving the copolymer (a), a polymer syrup can be obtained by this method.

Examples of active energy rays used in the massive polymerization method include ultraviolet rays, laser rays, α rays, β rays, γ rays, X-rays, electron beams, etc., but they have good controllability, handleability, and cost. From this point of view, ultraviolet rays are preferably used. More preferably, ultraviolet rays having a wavelength of 200 nm or more and 400 nm or less are used. Ultraviolet rays can be irradiated using a light source such as a high-pressure mercury lamp, a microwave-excited lamp, a chemical lamp, or a black light. The illuminance of the light source ^{is preferably 1.0 mW / cm 2} or more and 50 mW / cm ² or less.

Examples of photopolymerization initiators are acetophenone, 3-methylacetophenone, benzyldimethylketal, 2,2-dimethoxy-1,2-diphenylethane-1-one, 1- (4-isopropylphenyl) -2-hydroxy-. 2-Methylpropan-1-one, 2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropane-1-one, 2-hydroxy-2-methyl-1-phenylpropane-1-one, etc. Acetphenones; benzophenones such as benzophenone, 4-chlorobenzophenone, 4,4'-diaminobenzophenone; benzoin ethers such as benzoinpropyl ether and benzoin ethyl ether; thioxanthones such as 4-isopropylthioxanthone; 1-hydroxy Cyclohexyl-phenylketone, xanthone, fluorenone, camphorquinone, benzaldehyde, anthraquinone and the like. These photopolymerization initiators can be used alone or in combination of two or more.

Commercially available products may be used as the photopolymerization initiator, and examples of the commercially available products include, for example, Omnirad (registered trademark) 184, 819, 907, 651, 1800, 1800, 819, 369, 261, 1173, TPO (above, IGM Resins BV (manufactured by IGM Resins BV), EzaCure (registered trademark) KIP150, TZT (above, IGM Resins BV), Kayacure (registered trademark) BMS, DMBI (above, manufactured by Nippon Kayaku Co., Ltd.), etc. Can be mentioned.

The amount of the photopolymerization initiator used is preferably 0.0005 parts by mass or more and 1 part by mass or less, more preferably 0.002 parts by mass or more and 0.5 parts by mass or less, based on 100 parts by mass of the total amount of the raw material monomers. be.

The content of the copolymer (a) in the polymer syrup is preferably 3% by mass or more and 20% by mass or less, more preferably, with respect to the total mass of the polymer syrup (A) from the viewpoint of the viscosity of the pressure-sensitive adhesive composition. Is 5% by mass or more and 15% by mass or less.

In the present invention, the composition of the copolymer (a) (content of each monomer) and the composition of the components (a1) to (a5) may be the same or different. However, in order to improve the properties of the pressure-sensitive adhesive layer and its cured product, it is preferable that the compositions are the same.

In the present invention, the weight average molecular weight (Mw) of the copolymer (a) is preferably 300,000 or more and 3 million or less, and more preferably 500,000 or more and 2 million or less. Within this range, the coatability when forming the pressure-sensitive adhesive layer and the durability as the pressure-sensitive adhesive layer are excellent. The weight average molecular weight (Mw) of the copolymer (a) can be measured by the method described in Examples.

In the present invention, the glass transition temperature (Tg) of the copolymer (a) is preferably −40 ° C. or higher and 20 ° C. or lower, and more preferably −20 ° C. or higher and 10 ° C. or lower. Within this range, durability, step followability, and workability are excellent. For the glass transition temperature (Tg) of the copolymer (a), a value calculated using the Fox formula based on the glass transition temperature of the homopolymer of each monomer used is adopted.

[Chain transfer agent (B)]
The chain transfer agent (B) has a function of stopping the elongation of the growth polymer by receiving radicals from the growth polymer chain, and the chain transfer agent (B) receiving the radicals has a function of initiating the polymerization reaction again by attacking the monomer. .. In the present invention, the chain transfer agent (B) contributes to the improvement of step followability.

Examples of the chain transfer agent (B) include primary or secondary monofunctional thiol compounds or polyfunctional thiol compounds, thioglycolic acid compounds, thiocarbonyl compounds, mercaptopropionic acid compounds and the like.

Specific examples of the chain transfer agent (B) include β-mercaptopropionic acid, 2-ethylhexyl-3-mercaptopropionate, n-octyl-3-mercaptopropionate, and methoxybutyl-3-mercaptopropionate. , Stearyl-3-mercaptopropionate, trimethylpropanthris (3-mercaptopropionate), tris-[(3-mercaptopropionyloxy) -ethyl] -isocyanurate, pentaerythritol tetrakis (3-mercaptopropionate) ), Tetraethylene glycol bis (3-mercaptopropionate), dipentaerythritol hexakis (3-mercaptopropionate), 3,3'-thiodipropionic acid, dithiopropionic acid, laurylthiopropionic acid, thioglycol Examples thereof include acid, ammonium thioglycolate, monoethanolamine thioglycolate, and diammonium thioglycolate. Commercially available products include product names BMPA, EHMP, NOMP, MBMP, STMP, TMMP, TEMPIC, PEMP, EGMP-4, DPMP, TDPA, DTDPA, LTPA, ATG, TG-MEA, DATG (above, SC Organic Chemistry Co., Ltd.) Made) and the like. These may be used alone or in combination of two or more.

The amount of the chain transfer agent (B) is 0.01 part by mass or more and 5 parts by mass or less with respect to 100 parts by mass of the main agent (A). If the amount of the chain transfer agent (B) is less than 0.01 parts by mass, the molecular weight of the pressure-sensitive adhesive layer becomes non-uniform and sufficient step followability cannot be obtained, or it becomes difficult to control the curing reaction, which is sufficient. In some cases, a pressure-sensitive adhesive layer having a smooth step-following property cannot be stably obtained. If the amount of the chain transfer agent (B) exceeds 5 parts by mass, the molecular weight of the pressure-sensitive adhesive composition may become too low and the durability may deteriorate. The amount of the chain transfer agent (B) is preferably 0.01 parts by mass or more and 3 parts by mass or less, and more preferably 0.05 parts by mass or more and 1 part by mass or less with respect to 100 parts by mass of the main agent (A). Yes, more preferably 0.05 parts by mass or more and 0.1 parts by mass or less. Within the above range, it is possible to stably obtain an adhesive layer having sufficient step followability and ensuring durability.

[Crosslinking agent (C)]
The pressure-sensitive adhesive composition of the present invention preferably further contains a cross-linking agent (C). The cross-linking agent (C) reacts with the copolymer (a) to form a cross-linked structure. Therefore, in the pressure-sensitive adhesive composition, the cross-linking agent (C) can mainly contribute to adhesiveness (stickiness) and durability.

In the present invention, the cross-linking agent (C) includes at least one selected from the group consisting of an isocyanate compound, a carbodiimide compound, an oxazoline compound, an epoxy compound, a polyfunctional (meth) acrylic acid ester monomer, and a peroxide. Is preferable. Hereinafter, these various cross-linking agents will be described.

[Isocyanate compound]
Specific examples of the isocyanate compound used as the cross-linking agent (C) in the present invention include diisocyanate dimerate, 2,4-tolylene diisocyanate (2,4-TDI), and 2,6-tolylene diisocyanate (2). , 6-TDI), 4,4'-diphenylmethane diisocyanate (4,4'-MDI), 2,4'-diphenylmethane diisocyanate (2,4'-MDI), 1,4-phenylenediocyanate, xylylene diisocyanate (XDI) ), Tetramethylxylidene diisocyanate (TMXDI), trizine diisocyanate (TODI), 1,5-naphthalenediisocyanate (NDI) and other aromatic diisocyanates; allyl isocyanate, hexamethylene diisocyanate (HDI), trimethylhexamethylene diisocyanate (TMHDI) , Lysine diisocyanates, aliphatic diisocyanates such as norbornenan diisocyanate methyl (NBDI); transcyclohexane-1,4-diisocyanates, isophorone diisocyanates (IPDI), H6-XDI (hydrogenated XDI), H12-MDI (hydrogenated MDI) ) And other alicyclic diisocyanates; carbodiimide-modified diisocyanates of the above diisocyanates; or these isocyanurate-modified diisocyanates and the like. Adducts of the above isocyanate compounds and polyol compounds such as trimethylolpropane, polytetramethylene ether glycol (PTMG) and polypropylene glycol (PPG), and biuret and isocyanurates of these isocyanate compounds can also be preferably used.

As these isocyanate compounds, commercially available products or synthetic products may be used.

Examples of commercially available products include Coronate (registered trademark) L, Coronate (registered trademark) HL, Coronate (registered trademark) HX, Coronate (registered trademark) 2030, Coronate (registered trademark) 2031 (all manufactured by Toso Co., Ltd.). Takenate (registered trademark) D-102, Takenate (registered trademark) D-110N, Takenate (registered trademark) D-200, Takenate (registered trademark) D-202 (all manufactured by Mitsui Kagaku Co., Ltd.), Duranate (registered trademark) 24A-100, Duranate® TPA-100, Duranate® TKA-100, Duranate® P301-75E, Duranate® E402-90T, Duranate® E405-80T, Duranate (Registered Trademark) TSE-100, Duranate (Registered Trademark) D-101, Duranate (Registered Trademark) D-201 (all manufactured by Asahi Kasei Co., Ltd.), Sumijuru (Registered Trademark) N-75, N-3200, N- 3300 (all manufactured by Sumika Cobestro Urethane Co., Ltd.), Samplen (registered trademark) P-6090 (PTMG / MDI series), Samplen (registered trademark) P-663L (PTMG / TDI series), Samplen (registered trademark) P -664 (PTMG / TDI series), Samplen (registered trademark) P-665 (PTMG / TDI series), Samplen (registered trademark) P-667 (PTMG / TDI series), Samplen (registered trademark) P-868 (PTMG /) HMDI series), Samplen (registered trademark) P-870 (PTMG / HMDI series), Samplen (registered trademark) C-810 "(PPG / TDI series) (all manufactured by Sanyo Kasei Kogyo Co., Ltd.), TAIC (Mitsubishi Chemical Co., Ltd.) (Made by company), etc., but not limited to these.

The isocyanate compound may be used in the form of an unblocked isocyanate compound. Further, it may be used in the form of a blocked isocyanate compound obtained by reacting with a blocking agent that protects an isocyanate group. The blocked isocyanate compound may be a commercially available product or a synthetic product. Examples of commercially available blocked isocyanate compounds include Duranate (registered trademark) MF-B60X (block 1,6-hexamethylene diisocyanate) and Duranate (registered trademark) MF-K60X (block 1,6-hexa) manufactured by Asahi Kasei Co., Ltd. Methylene diisocyanate), Coronate (registered trademark) AP-M manufactured by Toso Co., Ltd., 2503, 2507, 2513, 2515, Millionate (registered trademark) MS-50, Takenate (registered trademark) B-830 (registered trademark) manufactured by Mitsui Chemicals Co., Ltd. Block tolylene isocyanate), B-815N (block 4,4'-methylenebis (cyclohexylisocyanate)), B-842N (block 1,3-bis (isocyanatemethyl) cyclohexane), B-846N (block 1, 3-Bis (isocyanate methyl) cyclohexane), B-874N (block isophoron diisocyanate), B-882N (block 1,6-hexamethylene diisocyanate), Burnock (registered trademark) manufactured by DIC Co., Ltd. ) D-500 (block tolylene diisocyanate), D-550 (block 1,6-hexamethylene diisocyanate), Elastron (registered trademark) BN-P17 (block) manufactured by Daiichi Kogyo Seiyaku Co., Ltd. 4,4'-Diphenylmethane diisocyanate), BN-04, BN-08, BN-44, BN-45 (above, blocked urethane-modified polyisocyanate) and the like. Of these, Duranate® MF-K60X is preferred.

From the viewpoint of further improving the durability of the pressure-sensitive adhesive, the isocyanate compound is preferably used in the form of an unblocked isocyanate compound.

[Carbodiimide compound]
In the present invention, the carbodiimide compound used as the cross-linking agent (C) is not particularly limited. As an example, a high molecular weight polycarbodiimide produced by decarboxylating a diisocyanate in the presence of a carbodiimide catalyst is used.

Examples of the diisocyanate used in the decarbonation condensation reaction include 4,4'-diphenylmethane diisocyanate, 3,3'-dimethoxy-4,4'-diphenylmethane diisocyanate, and 3,3'-dimethyl-4,4'-. Diphenylmethane diisocyanate, 4,4'-diphenyl ether diisocyanate, 3,3'-dimethyl-4,4'-diphenyl ether diisocyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 1-methoxyphenyl-2,4 Examples thereof include −diisocyanate, isophorone diisocyanate, 4,4′-dicyclohexylmethane diisocyanate, and tetramethylxylylene diisocyanate.

Examples of the carbodiimidization catalyst used in the decarboxylation condensation reaction include 1-phenyl-2-phospholene-1-oxide, 3-methyl-2-phospholene-1-oxide, and 1-ethyl-3-methyl-. Examples thereof include 2-phospholene-1-oxide, 1-ethyl-2-phospholene-1-oxide, and phosphorene oxides such as these 3-phosphoren isomers.

As the high molecular weight polycarbodiimide, a commercially available product or a synthetic product may be used. Examples of commercially available products include the Carbodilite (registered trademark) series manufactured by Nisshinbo Chemical Co., Ltd. Among them, Carbodilite (registered trademark) V-01, V-03, V-05, V-07, and V-09 are preferable because they have excellent compatibility with organic solvents.

[Oxazoline compound]
In the present invention, the oxazoline compound used as the cross-linking agent (C) is not particularly limited. However, an oxazoline group-containing acrylic / styrene polymer having a main chain composed of an acrylic skeleton or a styrene skeleton and having an oxazoline group in the side chain of the main chain is preferable. Further, an oxazoline group-containing polymer such as an oxazoline group-containing acrylic polymer containing a main chain composed of an acrylic skeleton and having an oxazoline group in the side chain of the main chain is also preferable.

Examples of the oxazoline group include a 2-oxazoline group, a 3-oxazoline group, a 4-oxazoline group and the like, and a 2-oxazoline group is preferable.

Further, the oxazoline group-containing polymer may have a polyoxyalkylene group in addition to the oxazoline group.

Specific examples of the oxazoline group-containing polymer include oxazoline group-containing acrylics such as Epocross (registered trademark) WS-300, Epocross (registered trademark) WS-500, and Epocross (registered trademark) WS-700 manufactured by Nippon Catalyst Co., Ltd. Examples thereof include oxazoline group-containing acrylic / styrene polymers such as Epocross (registered trademark) K-1000 series and Epocross (registered trademark) K-2000 series manufactured by Nippon Catalyst Co., Ltd.

[Epoxy compound]
In the present invention, the epoxy compound used as the cross-linking agent (C) is not particularly limited, and a known epoxy-based cross-linking agent can be appropriately used. Commercially available epoxy compounds include, for example, "TETRAD (registered trademark) -C" and "TETRAD (registered trademark) -X" manufactured by Mitsubishi Gas Chemical Company, Ltd., and "ADEKA Resin (registered trademark) EPU series" manufactured by ADEKA Corporation. , "Adeka Resin (registered trademark) EPR series", "Selokiside (registered trademark)" manufactured by Daicel Co., Ltd., and other liquid epoxy resins. These liquid epoxy resins are preferable because they facilitate a mixing operation when producing an adhesive for an optical film.

[Polyfunctional (meth) acrylic acid ester monomer]
The polyfunctional (meth) acrylic acid ester monomer used as the cross-linking agent (C) of the present invention is a (meth) acrylic acid ester monomer having a plurality (two or more) of radically polymerizable functional groups. Examples of such a monomer include a hydrocarbon-based or hydrocarbon ether-based polyfunctional monomer. A hydrocarbon-based or hydrocarbon ether-based polyfunctional monomer is a compound in which a hydroxy group of a polyhydric alcohol having a hydrocarbon group having 10 or more and 100 or less carbon atoms or a hydrocarbon ether group as a main skeleton is (meth) acrylated. be. The compound is preferable from the viewpoint of improving adhesiveness by crosslinking. Examples of the hydrocarbon group of the polyhydric alcohol include a linear or branched aliphatic hydrocarbon group, an aromatic hydrocarbon group, an alicyclic hydrocarbon group, and a hydrocarbon group combining these hydrocarbon groups. .. Examples of the hydrocarbon ether group include those obtained by etherifying the hydrocarbon group. Examples of the polyhydric alcohol having a hydrocarbon ether group as a main skeleton include compounds in which an alkylene oxide having 2 or more and 4 or less carbon atoms is added to the polyhydric alcohol (additional number of 1 or more and 30 or less). Further, polyalkylene glycol (addition number 1 or more and 30 or less) obtained from an alkylene oxide having 2 or more and 4 or less carbon atoms can be mentioned.

Specific examples of the above-mentioned hydrocarbon-based bifunctional monomer include, for example, ethylene glycol di (meth) acrylate, 1,3-butylene glycol di (meth) acrylate, 1,4-butanediol di (meth) acrylate, 1 , 6-Hexansyldi (meth) acrylate, di (meth) acrylate of alkylene glycols such as neopentylglucol di (meth) acrylate; cyclohexanedimethanol di (meth) acrylate, tricyclodecanedimethanol di (meth) ) Di (meth) acrylate of a diol compound having an alicyclic hydrocarbon group such as acrylate (dimethylol-tricyclodecanediacrylate); Di (meth) acrylate of a diol compound having an aromatic hydrocarbon group such as bisphenol A di (meth) acrylate Examples include (meth) acrylate.

Specific examples of the hydrocarbon ether-based bifunctional monomer include alkoxylated hexanediol di (meth) acrylate, alkoxylated cyclohexanedimethanol di (meth) acrylate, and alkoxylated di (meth) acrylate. , Alkylated neopentyl glycol di (meth) acrylate, alkoxylated bisphenol A di (meth) acrylate, etc. Di (di) of the compound in which alkylene oxide is added to the alkylene glycol or diol compound described in the above hydrocarbon-based bifunctional monomer Meta) Acrylate and the like can be mentioned. Specific examples of the hydrocarbon ether-based bifunctional monomer include diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, and polyethylene glycol di (meth) acrylate. Examples thereof include di (meth) acrylate of polyalkylene glycol such as tripropylene glycol di (meth) acrylate and dipropylene glycol di (meth) acrylate, and dioxane glycol di (meth) acrylate.

Examples of the hydrocarbon-based or hydrocarbon ether-based trifunctional monomer or tetrafunctional monomer include trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, and glyceryl tri (meth) acrylate. Tri (meth) acrylate or tetra (meth) acrylate of a tri or tetraol compound such as pentaerythritol tetra (meth) acrylate or trimethylolpropane tetra (meth) acrylate, or a compound obtained by adding an alkylene oxide to the above tri or tetraol compound. Examples thereof include tri (meth) acrylate and tetra (meth) acrylate.

Examples of the monomer other than the above-mentioned hydrocarbon-based or hydrocarbon-based monomer include polyester poly (meth) acrylate having two or more (meth) acryloyl groups at the terminal, epoxy (meth) acrylate, and the like.

[Polyfunctional allyl monomer]
The polyfunctional allyl monomer used as the cross-linking agent (C) of the present invention is a monomer having at least one allyl group and having a plurality of (two or more) radically polymerizable functional groups including the allyl group. Examples of such a monomer include allyl (meth) acrylate, diallyl phthalate (DAP), trimethylolpropane diallyl ether, pentaerythritol triallyl ether, and triallyl isocinnurate.

[Peroxide]
In the present invention, the peroxide used as the cross-linking agent (C) is not particularly limited, and known peroxides can be used. Further, as the peroxide, those having a one-minute half-life temperature of 80 ° C. or higher and 160 ° C. or lower are preferable in consideration of productivity and stability. It is more preferable that the half-life temperature for 1 minute is 80 ° C. or higher and 140 ° C. or lower. More preferably, it is 80 ° C. or higher and 125 ° C. or lower, and particularly preferably 90 ° C. or higher and 125 ° C. or lower. The "half-life of peroxide" is an index showing the decomposition rate of peroxide, and means the time until the residual amount of peroxide is halved. The decomposition temperature for obtaining a half-life at a certain time and the half-life time at a certain temperature are described in the manufacturer's catalog or the like. For example, it is described in the 9th edition (May 2003) of the organic peroxide catalog published by NOF CORPORATION.

Examples of such peroxides include, for example, diisopropylperoxydicarbonate (1 minute half-life temperature 88.3 ° C., hereinafter, the temperature in parentheses indicates 1 minute half-life temperature), di (2-ethylhexyl). ) Peroxydicarbonate (90.6 ° C), bis (4-t-butylcyclohexyl) peroxydicarbonate (92.1 ° C), di-sec-butylperoxydicarbonate (92.4 ° C), t- Butyl peroxyneodecanoate (103.5 ° C), t-hexyl peroxypivalate, (109.1 ° C), t-butylperoxypivalate (110.3 ° C), dilauroyl peroxide (116. 4 ° C.), bis-n-octanoyl peroxide (117.4 ° C.), 1,1,3,3-tetramethylbutylperoxy-2-ethylhexanoate (124.3 ° C.), di (4-4.3 ° C.) Methylbenzoyl) peroxide (128.2 ° C), dibenzoyl peroxide (benzoyl peroxide) (130.0 ° C), a mixture of dibenzoyl peroxide, benzoyl m-methylbenzoyl peroxide and m-toluyl peroxide ( 131.1 ° C.), t-butylperoxybutyrate (136.1 ° C.) and the like. Of these, diisopropylperoxydicarbonate, bis (4-t-butylcyclohexyl) peroxydicarbonate, and t-butylperoxyneodecanoate are preferably used. These may be used alone, but it is also preferable to use two or more in combination from the viewpoint of adjusting the reactivity. As an example of using two or more kinds in combination, a combination of di (4-t-butylcyclohexyl) peroxydicarbonate and dilauroyl peroxide is preferable.

As the peroxide, a commercially available product or a synthetic product may be used. Commercially available products include, for example, trade names manufactured by Nichiyu Co., Ltd .: "Parloyl (registered trademark, same below) IB" (85.1 ° C), "Park Mill (registered trademark, same below) ND" (94.0 ° C). ), "Parloyl NPP" (94.0 ° C.), "Parloyl IPP" (88.3 ° C.), "Parloyl SBP" (92.4 ° C.), "Perocta (registered trademark, same below) ND" (92.4 ° C.) ° C.), "Perloyl TCP" (92.1 ° C), "Perloyl OPP" (90.6 ° C), "Perhexyl (registered trademark, same below) ND" (100.9 ° C), "Perbutyl (registered trademark, hereinafter)" Same) ND "(103.5 ° C)," Perbutyl NHP "(104.6 ° C)," Perhexyl PV "(109.1 ° C)," Perbutyl PV "(110.3 ° C)," Parloyl 355 "(112) .6 ° C), "Parloyl L" (116.4 ° C), "Perocta O" (124.3 ° C), "Parloyl SA" (131.8 ° C), "Perhexa (registered trademark, same below) 25O" ( 118.8 ° C), "Perhexyl O" (132.6 ° C), "Niper (registered trademark, same below) PMB" (128.2 ° C), "Perbutyl O" (134.0 ° C), "Niper BMT" (131.1 ° C), "Niper BW" (130.0 ° C), "Niper BMT-K40" (131.1 ° C), "Niper BMT-M" (131.1 ° C), "Perhexa MC" (142) .1 ° C), "Perhexa TMH" (147.1 ° C), "Perhexa HC" (149.2 ° C), "Perhexa C" (153.8 ° C), "Pertetra (registered trademark, same below) A" ( 153.8 ° C.), "Perhexyl I" (155.0 ° C.), "Perbutyl L" (159.4 ° C.), "Perbutyl I" (158.8 ° C.), "Perhexa 25Z" (158.2 ° C.), Examples thereof include "perbutyl A" (159.9 ° C.) and "perhexa 22" (159.9 ° C.).

In the present invention, the cross-linking agent (C) may be used alone or in combination of two or more. When two or more kinds are combined, two or more kinds of cross-linking agents of the same system (for example, two kinds of isocyanate compounds) may be combined. One or more cross-linking agents of different strains may be combined (for example, one isocyanate compound and one peroxide).

The content of the cross-linking agent (C) in the pressure-sensitive adhesive for optical films of the present invention is not particularly limited, but may be 0.01 parts by mass or more and 5 parts by mass or less with respect to 100 parts by mass of the main agent (A). preferable. The content is more preferably 0.02 parts by mass or more and 4 parts by mass or less, and further preferably 0.03 parts by mass or more and 3 parts by mass or less. Particularly preferably, it is 0.05 parts by mass or more and 3 parts by mass or less. When the content of the cross-linking agent (C) is within the above range, durability and step followability can be ensured.

[Silane Coupling Agent (D)]
The pressure-sensitive adhesive for optical films of the present invention preferably further contains a silane coupling agent (D). The silane coupling agent (D) can mainly contribute to the improvement of durability and the improvement of adhesion to glass when the adherend is glass in the pressure-sensitive adhesive composition according to the present invention. In addition, in this specification, a "silane coupling agent" means a silane compound which does not have a siloxane bond (Si—O—Si bond) and has two or more reactive groups in the molecule.

In the present invention, the silane coupling agent (D) is not particularly limited. Specifically, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, methyltrimethoxysilane, dimethyldimethoxysilane, trimethylmethoxysilane, n-propyltrimethoxysilane, ethyltrimethoxysilane, Diethyldiethoxysilane, n-butyltrimethoxysilane, n-hexyltriethoxysilane, n-octyltrimethoxysilane, phenyltrimethoxysilane, diphenyldimethoxysilane, cyclohexylmethyldimethoxysilane, vinyltricrolsilane, vinyltrimethoxysilane, vinyl Triethoxysilane, vinyltris (β-methoxyethoxy) silane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ -Glysidoxypropyltriethoxysilane, γ-methacryloxypropylmethyldimethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-methacryloxypropylmethyldiethoxysilane, γ-methacryloxypropyltriethoxysilane, γ-acryloxy Propyltrimethoxysilane, N-β- (aminoethyl) -γ-aminopropylmethyldimethoxysilane, N-β- (aminoethyl) -γ-aminopropyltrimethoxysilane, N-β- (aminoethyl) -γ- Aminopropyltriethoxysilane, γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, γ-chloropropyltrimethoxysilane, γ-mercaptopropyltrimethoxysilane, Examples thereof include γ-mercaptopropylmethyldimethoxysilane, bis- (3- [triethoxysilyl] propyl) tetrasulfide, and γ-isocyanuppropyltriethoxysilane. Furthermore, a silane coupling agent containing a silane coupling agent having a functional group such as an epoxy group (glycidoxy group), an amino group, a mercapto group, or a (meth) acryloyl group, and a functional group capable of reacting with these functional groups. Agents can be mentioned. Further, a compound having a hydrolyzable silyl group obtained by reacting each functional group with another coupling agent, polyisocyanate or the like at an arbitrary ratio can also be used.

As the silane coupling agent (D), a commercially available product or a synthetic product may be used. Commercially available products of the silane coupling agent (D) include, for example, KBM-303, KBM-403, KBE-402, KBE-403, KBE-502, KBE-503, KBM-5103, KBM-573, KBM-802. , KBM-803, KBE-846, KBE-9007 (all manufactured by Shin-Etsu Chemical Co., Ltd.) and the like.

The silane coupling agent (D) can be used alone or in combination of two or more.

When the pressure-sensitive adhesive for an optical film of the present invention contains a silane coupling agent (D), the content of the silane coupling agent (D) is not particularly limited. However, it is preferably 0.001 part by mass or more and 5 parts by mass or less with respect to 100 parts by mass of the main agent (A). The content is more preferably 0.001 part by mass or more and 4 parts by mass or less, and further preferably 0.01 part by mass or more and 3 parts by mass or less. When the content is 0.001 part by mass or more, it is preferable from the viewpoint that the effect on durability can be exhibited even in a harsh environment. On the other hand, when the content is 5 parts by mass or less, it is preferable from the viewpoint that the deterioration of heat foaming derived from the low molecular weight compound is eliminated.

[High softening point resin (E)]
The pressure-sensitive adhesive composition of the present invention preferably further contains a high softening point resin (E) having a softening point of 60 ° C. or higher and 200 ° C. or lower (hereinafter, also simply referred to as “high softening point resin (E)”). This is because by adding the high softening point resin (E), it is possible to provide an adhesive having a property of being hard to some extent at room temperature and softening (softening) at high temperature. It is preferable to add the high softening point resin (E) to give such properties, because durability can be ensured.

The high softening point resin (E) used in the present invention is preferably a resin having a softening point of 60 ° C. or higher and 200 ° C. or lower from the viewpoint of effectively exhibiting the above-mentioned effects. Therefore, conventionally known ones can be used. Specific examples thereof include an aliphatic petroleum resin, an alicyclic hydrocarbon resin, an aromatic petroleum resin, a completely hydrogenated aliphatic petroleum resin, and a fully hydrogenated alicyclic hydrocarbon resin. Fully hydrogenated aromatic petroleum resin, partially hydrogenated aliphatic petroleum resin, partially hydrogenated alicyclic hydrocarbon resin, partially hydrogenated aromatic petroleum resin and other petroleum resins, aromatic hydrocarbon resin, aliphatic Rodin-based resins (both rosins or rosin derivatives) such as saturated hydrocarbon resins, terpene resins, terpenephenol resins, hydrogenated terpene resins, kumaron-inden resins, rosinic acid, polymerized rosinic acid and rosin ester-based resins (loginate esters). ), Epoxy resin, phenol resin, oil-soluble phenol (resin), or modified resins thereof and the like can be preferably mentioned. These high softening point resins (E) may be used alone or in combination of two or more. Among these, an alicyclic hydrocarbon resin, a terpene phenol resin, and a terpene resin are more preferable from the viewpoint of good compatibility with the copolymer (a). Further, the high softening point resin (E) is a rosin ester resin from the viewpoint that the compatibility with other components of the pressure-sensitive adhesive is very good and transparency can be easily obtained when applied to an optical film. Is even more preferable.

As the high softening point resin (E), a synthetic product or a commercially available product may be used.

Examples of commercially available rosin ester resins include pine crystal (registered trademark, the same applies hereinafter) KR-85 (softening point 80-87 ° C., the temperature in parentheses below indicates the softening point), pine crystal KR- 612 (80-90 ° C), Pine Crystal KR-614 (84-94 ° C), Pine Crystal KE-100 (95-105 ° C), Pine Crystal KE-311 (90-100 ° C), Pine Crystal PE-590 ( 90-100 ° C), Pine Crystal KE-359 (94-104 ° C), Pine Crystal KE-604 (124-134 ° C), Pine Crystal KR-120 (110-130 ° C), Pine Crystal KR-140 (130-130-) 150 ° C), Pine Crystal KR-614 (84-94 ° C), Pine Crystal D-6011 (84-99 ° C), Pine Crystal KR-50M (145-160 ° C) (all manufactured by Arakawa Chemical Industries, Ltd.), etc. Can be mentioned. These are used as ultra-light color rosins, which are suitable for optical applications that require transparency.

Other examples of commercially available rosin ester-based resins include Super Ester A-75 (70-80 ° C), Super Ester A-100 (95-105 ° C), and Super Ester A-115 (108-120 ° C). ), Superester A-125 (120-130 ° C.), Tamanol (registered trademark, the same applies hereinafter) 460 (182-192 ° C.) (all manufactured by Arakawa Chemical Industry Co., Ltd.) and the like.

Examples of commercially available alicyclic hydrocarbon resins include, for example, Alcon (registered trademark, the same applies hereinafter) P-90 (85-95 ° C), Alcon P-100 (95-105 ° C), Alcon (registered trademark). ) P-115 (110-120 ° C), Alcon P-125 (120-130 ° C), Alcon P-140 (135-145 ° C), Alcon M-90 (85-95 ° C), Alcon M-100 (95) -105 ° C.), Alcon M-115 (110-120 ° C.), Alcon M-135 (130-140 ° C.) (all manufactured by Arakawa Chemical Industry Co., Ltd.) and the like.

Examples of commercially available terpenphenol resin products include Tamanol 803L (145-160 ° C.), Tamanol 901 (125-135 ° C.) (above, manufactured by Arakawa Chemical Industry Co., Ltd.), YS Polystar (registered trademark, the same applies hereinafter). U130 (125-135 ° C), YS Polystar U115 (110-120 ° C), YS Polystar T160 (155-165 ° C), YS Polystar T145 (140-150 ° C), YS Polystar T130 (125-135 ° C), YS Polystar T115 (110-120 ° C), YS Polystar T100 (95-105 ° C), YS Polystar T80 (75-85 ° C), YS Polystar S145 (140-150 ° C), YS Polystar G150 (145-155 ° C), YS Polystar G125 (120-130 ° C.), YS Polystar N125 (120-130 ° C.), YS Polystar K125 (120-130 ° C.), YS Polystar TH130 (125-135 ° C.) (all manufactured by Yasuhara Chemical Co., Ltd.) and the like can be mentioned.

Examples of commercially available terpene resin products include, for example, YS resin (registered trademark, the same applies hereinafter) PX1250 (120-130 ° C.), YS resin PX1150 (110-120 ° C.), YS resin PX1000 (95-105 ° C.), YS. Resin PX800 (75-85 ° C), YS Resin PX1150N (110-120 ° C), YS Resin TO125 (120-130 ° C), YS Resin TO115 (110-120 ° C), YS Resin TO105 (100-110 ° C), YS Examples thereof include resin TO85 (80-90 ° C.) (all manufactured by Yasuhara Chemical Co., Ltd.).

When the high softening point resin (E) is added to the pressure-sensitive adhesive composition of the present invention, the amount of the high softening point resin (E) added is not particularly limited. However, it is preferably 0.1 part by mass or more and 30 parts by mass or less with respect to 100 parts by mass of the main agent (A). The addition amount is more preferably 0.5 parts by mass or more and 25 parts by mass or less, and further preferably 1 part by mass or more and 20 parts by mass or less. When the content is 0.1 part by mass or more, it is preferable from the viewpoint that a softening effect is obtained during the durability test. On the other hand, when the content is 30 parts by mass or less, it is preferable from the viewpoint that deterioration of durability due to a low molecular weight substance can be suppressed. Further, it is preferable from the viewpoint that durability can be ensured even in a harsh environment such that a decrease in flexibility of the adhesive can be effectively suppressed even in a low temperature region such as −25 ° C. or lower.

High softening point The softening point of the resin (E) is preferably 60 ° C. or higher and 200 ° C. or lower. From the viewpoint of step followability, workability, improvement of adhesiveness, etc., 70 ° C. or higher and 150 ° C. or lower is more preferable. The softening point is more preferably 80 ° C. or higher and 140 ° C. or lower, and particularly preferably 85 ° C. or higher and 130 ° C. or lower. In the present invention, the value measured by the method described in JIS K6863 (1994) shall be adopted as the softening point.

[Other additive components]
The pressure-sensitive adhesive composition of the present invention may be a photopolymerization initiator, a solvent, a cross-linking accelerator, an antioxidant, a filler, a colorant (pigment, dye, etc.), an ultraviolet absorber, an antioxidant, a plasticizer, if necessary. Other known additive components such as agents, softeners, surfactants, and antistatic agents may be contained within a range that does not impair the effects of the present invention.

The photopolymerization initiator is used when forming the pressure-sensitive adhesive layer. Examples of photopolymerization initiators include α-diketones such as benzoin and diacetyl; benzophenone derivatives such as benzophenone; benzoic acid ester derivatives; acetophenone ether derivatives; acetophenone derivatives such as acetophenone; xanthone and thioxanthone derivatives; chlorosulfonyl and chloromethyl polynuclear compounds. Halogen-containing compounds such as aromatic compounds, chloromethyl heterocyclic compounds and chloromethylbenzophenones; triazines; fluorenones; haloalcans; acridins; redox couples of photoreducing dyes and reducing agents; organic sulfur compounds; Examples include peroxides.

Specific examples of the photopolymerization initiator include 1-hydroxyphenyl ketone, 2-methyl-1- (4- (methylthio) phenyl) -2-morpholinopropane-1-one, and (2-benzyl-2-dimethyl). Amino-1- (4-morpholinophenyl) -butanone-1, 1-hydroxy-cyclohexyl-phenyl-ketone, 2,2-dimethoxy-2-phenylacetophenone, 2-hydroxy-2-methyl-1-phenyl-propane- 1-one, 2-benzyl-2- (dimethylamino) -4-morpholinobutylphenone, 2-methyl-4'-(methylthio) -2-morpholino-propiophenone, 1,7- (9-acrydinyl) heptane , 2,2'-bis (o-chlorophenyl) -4,5,4', 5'-tetraphenyl-1,2'-biimidazole, 4,4'-dimethylaminobenzophenone, 4,4'-diethylaminobenzophenone , 7- (diethylamino) -4-methyl-2H-1-benzopyran-2-one (7- (diethylamino) -4-methylcoumarin, ethyl 4-dimethylaminobenzoate, ethyl 2-dimethylaminobenzoate, 4- Ethyl dimethylaminobenzoate (n-butoxy), p-dimethylaminobenzoic acid isoamylethyl ester, 2-ethylhexyl 4-dimethylaminobenzoate, 4,4'-diethylaminobenzophenone, diphenyl (2,4,6-trimethylbenzoyl) Examples thereof include phosphine oxide and the like. Examples of commercially available products include Omnirad (registered trademark) 907, 369, 184, 819 manufactured by IGM Resins B.V., NissoCure MABP manufactured by Nippon Soda Co., Ltd., and Hodoya Chemical Industry Co., Ltd. Examples thereof include EAB manufactured by the company, Kayacure (registered trademark) EPA and DMBI manufactured by Nippon Kayaku Co., Ltd., Quantacure DMB manufactured by International Bio-Synthetics, BEA, and Esolol 50 manufactured by Van Dyk. It can be used alone or in combination of two or more.

The amount of the photopolymerization initiator is preferably 0.01 parts by mass or more and 1 part by mass or less, and more preferably 0.05 parts by mass or more and 0.5 parts by mass with respect to 100 parts by mass of the copolymer (a). It is as follows. When the amount of the photopolymerization initiator is within the above range, the durability and the adhesive strength are excellent.

<Manufacturing (preparation) method of adhesive composition>
The pressure-sensitive adhesive composition of the present invention can be prepared by mixing the main agent (A), the chain transfer agent (B), and if necessary, other components. The mixing order and mixing temperature of each component are not particularly limited and can be appropriately adjusted by those skilled in the art.

[Adhesive layer for photocurable optical film]
According to another embodiment of the present invention, there is provided an adhesive layer for a photocurable optical film (also simply referred to as a "adhesive layer") obtained by curing the pressure-sensitive adhesive composition for a photocurable optical film. .. The pressure-sensitive adhesive layer is distinguished from the above-mentioned pressure-sensitive adhesive composition in that the reaction rate of the monomer is more than 95% by mass. Further, it is distinguished from the cured product of the pressure-sensitive adhesive layer described later in that it contains a certain amount or more of a polyfunctional compound and has reactivity.

The thickness of the pressure-sensitive adhesive layer is not particularly limited, but is preferably 20 μm or more and 1 mm or less, more preferably 30 μm or more and 500 μm or less, and further preferably 50 μm or more and 300 μm or less. When the thickness is 20 μm or more, it becomes easy to follow the printing step (usually about 1 μm or more and 100 μm or less). When the thickness is 1 mm or less, the coatability and the uniformity of the thickness of the pressure-sensitive adhesive layer can be ensured.

The weight average molecular weight of the pressure-sensitive adhesive layer is preferably 50,000 or more and 1 million or less, more preferably 100,000 or more and 800,000 or less, and further preferably 200,000 or more and 750,000 or less. A weight average molecular weight of 50,000 or more is preferable from the viewpoint of improving durability. When the weight average molecular weight is 1 million or less, it is preferable from the viewpoint of improving the step followability. In the present specification, the weight average molecular weight adopts the value measured by the method described in Examples described later.

[Manufacturing method of adhesive layer]
According to another embodiment of the present invention, the pressure-sensitive adhesive composition for a photocurable optical film is applied onto the peeled surface of the first release type sheet to form a coating film, and the second release is performed. Active energy is applied to the coating film via at least one of the first release sheet and the second release sheet, and a laminating step of laminating the peeled surface of the mold sheet so as to be in contact with the surface of the coating film. Provided is a method for producing an adhesive layer for a photocurable optical film, which comprises an active energy ray irradiation step of irradiating a line.

When the pressure-sensitive adhesive composition is used for an optical film, the pressure-sensitive adhesive composition may be applied and cured directly on the optical film to form a pressure-sensitive adhesive layer. However, the pressure-sensitive adhesive composition is applied on the peeled surface of the first release sheet (also referred to as "release film" or "separator") to form a coating film, and the obtained coating film is used. After performing a laminating step of laminating the peeled surface of the second release sheet so as to be in contact with the surface of the coating film, at least one of the first release sheet and the second release sheet. It is preferable that the pressure-sensitive adhesive composition is cured to form a pressure-sensitive adhesive layer by an active energy ray irradiation step of irradiating the coating film with active energy rays. Then, it is desirable to transfer the obtained pressure-sensitive adhesive layer to various optical films for use.

The release sheet with the pressure-sensitive adhesive layer can be rolled up together in the manufacturing process. When the pressure-sensitive adhesive layer is attached to various optical films or liquid crystal panels, a release sheet with a roll-shaped pressure-sensitive adhesive layer is cut or processed as necessary, and the release sheet is removed before use. Until the pressure-sensitive adhesive layer is put into practical use, the release sheet also serves to protect the pressure-sensitive adhesive layer.

Examples of the constituent materials of the release sheet include plastic films such as polyethylene, polypropylene, polyethylene terephthalate, and polyester films, porous materials such as paper, cloth, and non-woven fabrics, nets, foam sheets, metal foils, and laminates thereof. Appropriate thin-leaved body of the above can be mentioned. A plastic film is preferably used because of its excellent surface smoothness.

The thickness of the release sheet is usually 5 μm or more and 200 μm or less, preferably 5 μm or more and 100 μm or less.

The release sheet has been peeled off. Examples of the peeling treatment include a peeling treatment using a silicone-based, fluorine-based, long-chain alkyl-based, fatty acid amide-based mold release agent, silica powder, or the like.

The application method when applying the pressure-sensitive adhesive composition on the release sheet is not particularly limited. Examples of the coating method include roll coat, kiss roll coat, gravure coat, reverse coat, roll brush, spray coat, dip roll coat, bar coat, knife coat, air knife coat, curtain coat, lip coat, die coater and the like. Examples include a method such as extruded coating.

The coating film formed on the release sheet is irradiated with active energy rays. The irradiation of the active energy rays may be performed only through the first release sheet, only through the second release sheet, the first release sheet and the above. It may be done via both of the second release sheets (ie from both sides).

Examples of the active energy ray include ultraviolet rays, laser rays, α rays, β rays, γ rays, X-rays, electron rays and the like. From the viewpoint of good controllability, handleability, and cost, it is preferable to use ultraviolet rays as the active energy rays, and more preferably, ultraviolet rays having a wavelength of 200 nm or more and 400 nm or less are used. Ultraviolet rays are irradiated using a light source such as a high-pressure mercury lamp, a microwave-excited lamp, a chemical lamp, or a black light. Ultraviolet rays may be irradiated from only one surface of the coating film, but it is preferable to irradiate from both sides of the coating film from the viewpoint of obtaining a pressure-sensitive adhesive layer having more stable performance.

The illuminance of the active energy rays (preferably ultraviolet rays) is not particularly limited, but it is preferable to irradiate ultraviolet rays having a illuminance lower than usual to produce the pressure-sensitive adhesive layer. The illuminance is preferably at 0.5 mW / cm ² or more 50 mW / cm ² or less, more preferably at 1.0 mW / cm ² or more 30 mW / cm ² or less. When the illuminance is 0.5 mW / cm ² or more, the curing reaction can be satisfactorily performed. When the illuminance is 50 mW / cm ² or less, the pressure-sensitive adhesive layer having sufficient step-following property of the pressure-sensitive adhesive layer can be produced more stably.

In the production of the pressure-sensitive adhesive layer, the integrated light amount when irradiating with active energy rays (preferably ultraviolet rays) is not particularly limited, but is preferably 300 mJ / cm ² or more and 2000 mJ / cm ² or less, and more preferably 500 mJ / cm ^2. It is 1000 mJ / cm ² or less. When the integrated light amount is within the above range, the effect of the present invention can be obtained more efficiently.

[Optical member]
The pressure-sensitive adhesive layer is completely cured by further irradiating it with active energy rays after being attached to the optical film. As a result, an optical member in which the first optical film is provided on one surface of the cured product of the pressure-sensitive adhesive layer can be obtained. That is, according to another aspect of the present invention, there is provided an optical member having a cured product of the pressure-sensitive adhesive layer and a first optical film provided on one surface of the cured product. Further, it is possible to further have a glass, a polymethylmethacrylate plate, a polycarbonate plate or a second optical film on the surface of the cured product of the pressure-sensitive adhesive layer opposite to the surface on which the first optical film is provided. preferable.

<Easy-adhesion treatment layer (easy-adhesion layer)>
The optical member of the present invention preferably further has at least one easy-adhesion-treated layer between the first optical film and the cured product of the pressure-sensitive adhesive layer.

Further, as a more preferable form, the easy-adhesion-treated layer has a first easy-adhesion-treated layer and a second easy-adhesion-treated layer. In the optical member, a first optical film, a first easy-adhesion-treated layer, a second easy-adhesion-treated layer, and a cured product of an adhesive layer for an optical film are laminated in this order. As described above, in the optical member, the configuration having both the first and second easy-adhesion-treated layers is preferable from the viewpoint that the optical film and the cured product of the pressure-sensitive adhesive layer can be more firmly adhered to each other.

The easy-adhesion-treated layer may be a layer that treats the surface of a member that comes into contact with the pressure-sensitive adhesive layer, such as corona treatment or plasma treatment. Alternatively, a separate member such as a primer layer may be provided on the surface of the member that comes into contact with the pressure-sensitive adhesive layer.

The material constituting the primer layer is preferably a material having good adhesion to a member in contact with the primer layer and forming a film having excellent cohesive force. For example, various polymers, metal oxide sol, silica sol and the like are used, and among them, polymers are preferably used. The primer layer may have an antistatic function.

Examples of the polymers constituting the primer layer include oxazoline group-containing polymers, polyurethane resins, polyester resins, and polymers containing an amino group in the molecule. Of these, polyurethane resins and oxazoline group-containing polymers are more preferably used.

As the oxazoline group-containing polymer, a commercially available product can be used. For example, the Epocross (registered trademark) series manufactured by Nippon Shokubai Co., Ltd. (for example, Epocross (registered trademark) WS700) and the like can be mentioned, but the present invention is not limited thereto. Further, as the polyurethane resin, polyester resin, polymers containing an amino group in the molecule, etc., those disclosed in paragraphs "0107" to "0113" of JP2011-105918A can be appropriately adopted.

The thickness of the primer layer is preferably 10 nm or more and 5000 nm or less, and more preferably 50 nm or more and 500 nm or less. Within the above range, the optical characteristics can be maintained while exhibiting sufficient strength and adhesion.

The method for forming the primer layer is not particularly limited, and examples thereof include a method in which a raw material (undercoating agent) for the primer layer is applied and dried by using a coating method such as a coating method, a dipping method, or a spray method.

[Manufacturing method of optical member]
The optical member can be manufactured by arranging an optical film on one surface of the pressure-sensitive adhesive layer and irradiating the pressure-sensitive adhesive layer with active energy rays to completely cure the pressure-sensitive adhesive layer.

That is, the method for manufacturing an optical member according to another embodiment of the present invention includes a step of arranging an optical film on one surface of the pressure-sensitive adhesive layer and an integrated light amount of 300 mJ / cm ² or more and 5000 mJ / cm on the pressure-sensitive adhesive layer. ^It includes a step of irradiating active energy rays so as to be 2 or less. In the form in which the cover glass, the cover plastic film, and the second optical film are further provided on the other surface of the pressure-sensitive adhesive layer, the optical film is arranged on one surface of the pressure-sensitive adhesive layer, and the other. cover glass or a cover plastic film on the surface, after the second optical film is arranged, the active energy ray may be irradiated such that the integrated quantity of light to the adhesive layer becomes 300 mJ / cm ² or more 5000 mJ / cm ² or less.

The active energy rays are the same as the active energy rays used in the method for producing the pressure-sensitive adhesive layer, and examples thereof include ultraviolet rays, laser rays, α rays, β rays, γ rays, X-rays, and electron beams. From the viewpoint of good controllability, handleability, and cost, it is preferable to use ultraviolet rays as the active energy rays, and more preferably, ultraviolet rays having a wavelength of 200 nm or more and 400 nm or less are used. Ultraviolet rays are irradiated using a light source such as a high-pressure mercury lamp, a microwave-excited lamp, a chemical lamp, or a black light. Ultraviolet rays may be irradiated from only one surface of the coating film, but it is preferable to irradiate from both sides of the coating film from the viewpoint of obtaining a pressure-sensitive adhesive layer having more stable performance.

Illuminance of the active energy ray (e.g., ultraviolet light) is not particularly limited, preferably at 50 mW / cm ² or more 500 mW / cm ² or less, more preferably 80 mW / cm ² or more 300 mW / cm ² or less. When the illuminance is 50 mW / cm ² or more, the curing time can be shortened. When the illuminance is 500 mW / cm ² or less, excessive reaction can be suppressed and step followability can be ensured.

Integrated light quantity at the time of irradiation with an active energy ray (e.g., ultraviolet light) is not particularly limited, preferably at 500 mJ / cm ² or more 5000 mJ / cm ² or less, more preferably 1000 mJ / cm ² or more 3000 mJ / cm ² or less be. When the integrated light amount is within the above range, an optical member having sufficient durability can be manufactured.

[Image display device]
According to another embodiment of the present invention, an image display device having the above optical member is provided.

The image display device is not particularly limited, and examples thereof include a liquid crystal display device, an organic EL display device, a plasma display panel, and a micro LED display panel.

Hereinafter, the present invention will be specifically described with reference to Examples, but these Examples do not limit the present invention in any way. In the following description, all "parts" mean "parts by mass". Unless otherwise specified, the operation and the measurement of physical properties were performed under the conditions of room temperature of 23 ° C. and relative humidity of 55% RH.

<Measurement method of physical property value>
(Glass transition temperature (Tg))
The glass transition temperature of the copolymer (a) was calculated using the Fox formula based on the glass transition temperature of the homopolymer of each monomer used.

The weight average molecular weight (Mw) of the (meth) acrylic acid ester copolymer (a) and the pressure-sensitive adhesive layer was measured by GPC (gel permeation chromatography). Regarding the pressure-sensitive adhesive layer, the soluble content after being dissolved in tetrahydrofuran (THF) was measured in the same manner.

Analyzer: HLC-8120GPC manufactured by Tosoh Corporation
Column: Made by Tosoh Corporation, G7000HXL + GMHXL + GMHXL
Column size: 7.8 mm φ x 30 cm each 90 cm in total
Column temperature: 40 ° C
Flow rate: 0.8 ml / min
Injection volume: 100 μl
Eluent: Tetrahydrofuran Detector: Differential Refractometer (RI)
Standard sample: polystyrene.

<Manufacturing of thin polarizing plate>
A method for producing a thin polarizing plate will be described with reference to FIG.

A 20 μm-thick polyvinyl alcohol film was stretched up to 3 times between rolls having different speed ratios while dyeing in an iodine solution at 30 ° C. and a 0.3% concentration for 1 minute. Then, it was stretched at 60 ° C. in an aqueous solution containing 4% boric acid and 10% potassium iodide for 0.5 minutes until the total stretching ratio became 6 times. Then, it was washed by immersing it in an aqueous solution containing potassium iodide having a concentration of 1.5% at 30 ° C. for 10 seconds, and then dried at 50 ° C. for 4 minutes to obtain a polarizer 4 having a thickness of 7 μm.

A polycarbonate film 2 having a thickness of 20 μm on one side of the polarizing element 4, and a retardation film 6 (1/4 wave plate, manufactured by Teijin Co., Ltd.) having a thickness of 50 μm on the surface of the polarizer 4 on the opposite side. ”) Are laminated with polyvinyl alcohol-based adhesives 3 and 5, respectively, to prepare a thin polarizing plate 1 having a total thickness of 77 μm.

<Preparation of acrylic syrup (AS-1)>
[Manufacturing Example 1]
Four black light (FL20SBL manufactured by Sankyo Electric Co., Ltd.), which are UV lamps, were installed on each of the four sides in a reaction box that cuts off external ultraviolet rays. A 2 L capacity four-necked flask equipped with a stirrer, a thermometer, a nitrogen gas introduction tube and a cooling tube was installed in the reaction box. 35 parts of 2-ethylhexyl acrylate, 15 parts of isobornyl acrylate, 25 parts of 4-hydroxybutyl acrylate, and 25 parts of acryloyl morpholine were put into a flask, and the air in the flask was heated to 30 ° C. while replacing with nitrogen.

Next, 0.005 part of 2,2-dimethoxy-1,2-diphenylethane-1-one (Omnirad (registered trademark) 651; IGM Resins VV) was added as a photopolymerization initiator with stirring. And mixed uniformly.

In order to initiate the polymerization, ultraviolet rays were irradiated using a black light (integrated light amount 200 mJ / cm ² ). After the reaction was started, when the reaction temperature rose by 10 ° C., air was introduced into the flask by an air pump to stop the reaction and obtain an acrylic syrup (as-1). 100 g of the acrylic syrup (as-1) contained 10.5 g of the (meth) acrylic acid ester copolymer (a-1) and 89.5 g of the unreacted monomer. Table 1 shows the glass transition temperature (Tg) and the weight average molecular weight (Mw) of the (meth) acrylic acid ester copolymer (a-1) contained in the acrylic syrup (AS-1).

[Manufacturing Examples 2 to 19]
Acrylic syrup (as-2) to Production Example 1 in the same manner as in Production Example 1 except that the types and proportions of the monomers and the amount of the photopolymerization initiator were changed as shown in Table 1 below. (As-19) were obtained respectively. In 100 g of acrylic syrups (as-2) to (as-19), 10.5 g of (meth) acrylic acid ester copolymers (a-2) to (a-19) and 89 unreacted monomers. Each contained 5 g. The glass transition temperature (Tg) and weight average molecular weight (Mw) of the (meth) acrylic acid ester copolymers (a-2) to (a-19) contained in the acrylic syrups (as-2) to (as-19), respectively. ) Is shown in Table 1 below.

Each monomer in Table 1 is as follows. The blanks in Table 1 indicate that the monomer is not used.

2EHA: 2-ethylhexyl acrylate (homopolymer Tg-68 ° C, manufactured by Nippon Shokubai Co., Ltd.)
IBXA: Isobonyl acrylate (homopolymer Tg 97 ° C, manufactured by Osaka Organic Chemical Industry Co., Ltd.)
CHA: Cyclohexyl acrylate (homopolymer Tg 15 ° C, manufactured by Osaka Organic Chemical Industry Co., Ltd.)
4HBA: 4-Hydroxybutyl acrylate (homopolymer Tg-32 ° C, manufactured by Osaka Organic Chemical Industry Co., Ltd.)
ACMO (registered trademark): Acryloyl morpholine (homopolymer Tg 145 ° C, manufactured by KJ Chemicals Co., Ltd.)
BzA: Benzyl acrylate (homopolymer Tg 9 ° C, manufactured by Hitachi Kasei Co., Ltd.)
i-StA: Isostearyl acrylate (homopolymer Tg-18 ° C, manufactured by Osaka Organic Chemical Industry Co., Ltd.)
DTD-A: 2-decyltetradecanyl acrylate (homopolymer Tg-36 ° C, manufactured by Kyoeisha Chemical Co., Ltd. EHDG-AT: 2-ethylhexyl-diglucol acrylate (light acrylate EHDG-AT, homopolymer Tg-70 ° C, Kyoeisha) Made by Chemical Co., Ltd.).

<Preparation of adhesive composition, adhesive layer and polarizing plate with adhesive layer>
[Example 1]
Dipentaerythritol hexaacrylate (A) as a cross-linking agent (C) with respect to 100 parts of the (meth) acrylic acid ester copolymer (a-1) in the acrylic syrup (as-1) obtained in Production Example 1. -DPH; Shin-Nakamura Chemical Co., Ltd.) 0.05 parts, 2-ethylhexyl-3-mercaptopropionate (EHMP; SC Organic Chemical Co., Ltd.) 0.1 parts as a chain transfer agent, and a photopolymerization initiator As a result, 0.1 part of 1-hydroxycyclohexyl-phenylketone (Omnirad (registered trademark) 184; manufactured by IGM Resins VV) was added, and the mixture was mixed and defoamed to obtain a pressure-sensitive adhesive composition.

The obtained pressure-sensitive adhesive composition was applied to a peel-treated surface of a polyethylene terephthalate (PET) film having a thickness of 75 μm on which one side was peel-treated (silicone-treated) so as to have a coating thickness of 150 μm. By sticking the peeled surface of the peeled PET film having a thickness of 75 μm on the coated surface, the PET films were arranged above and below the pressure-sensitive adhesive composition and sealed in a sandwich shape. An adhesive layer was obtained by irradiating from the top and bottom with ultraviolet rays of 2.0 mW / cm ² (integrated light intensity: 400 mJ / cm ^{2 for each of the top and bottom) using a black light.}

Next, one PET film was peeled off to expose the pressure-sensitive adhesive layer, and the pressure-sensitive adhesive layer and a thin polarizing plate were bonded to each other to prepare a polarizing plate with a pressure-sensitive adhesive layer.

[Examples 2-28, Comparative Examples 1-9]
In <Preparation of Adhesive Composition> of Example 1, the same method as in Example 1 was used except that the type of acrylic syrup, the type of additive, and the amount of the additive were changed as shown in Table 2 below. A pressure-sensitive adhesive composition, a pressure-sensitive adhesive layer, and a polarizing plate with a pressure-sensitive adhesive layer were obtained.

Each component in Table 2 is as follows. The blanks in Table 2 indicate that the component is not used.

EDMA: Ethylene glycol dimethacrylate (manufactured by Mitsubishi Chemical Corporation)
DCP-A: Dimethylol-tricyclodecanediacrylate (light acrylate DCP-A, manufactured by Kyoeisha Chemical Co., Ltd.)
TMP-A: Trimethylolpropane triacrylate (light acrylate TMP-A, manufactured by Kyoeisha Chemical Co., Ltd.)
DAP: Dialyl phthalate (manufactured by Osaka Soda Co., Ltd.)
TAIC: Triallyl isocyanate (manufactured by Mitsubishi Chemical Corporation)
D-110N: Adduct of xylylene diisocyanate (XDI) and trimethylolpropane (Takenate (registered trademark) D-110N, manufactured by Mitsui Chemicals, Inc.)
A201H: Polyhexamethylene diisocyanate (Duranate (registered trademark) A201H, manufactured by Asahi Kasei Corporation)
TCP: Bis (4-t-butylcyclohexyl) peroxydicarbonate (Parloyl (registered trademark) TCP, manufactured by NOF CORPORATION)
KBE-403: 3-glycidoxypropyltrimethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd.)
KE-100: Pine crystal KE-100 (rosin ester resin, manufactured by Arakawa Chemical Industry Co., Ltd.)
TPO: Diphenyl (2,4,6-trimethylbenzoyl) phosphine oxide (Omnirad® TPO, manufactured by IGM Resins BV)
The composition of the pressure-sensitive adhesive composition is shown in Table 2 below.

<Evaluation of adhesive layer>
(Step followability)
The other remaining PET film was peeled off from the polarizing plate with the pressure-sensitive adhesive layer prepared in Examples and Comparative Examples to expose the pressure-sensitive adhesive layer. Then, the pressure-sensitive adhesive layer and a polycarbonate plate having a thickness of 0.5 mm having a printing step of 50 μm were laminated (temperature of the laminate roll: 25 ° C. or 60 ° C.). Next, the polarizing plate with the pressure-sensitive adhesive layer was completely adhered to the polycarbonate plate by autoclaving at 50 ° C. and 0.5 MPa for 15 minutes. Then, from the polycarbonate plate side, ultraviolet rays (UVA, illuminance: 100 mW / cm ² , integrated light amount: 2000 mJ / cm ² ) were irradiated using a metal halide lamp. The appearance was visually evaluated, and the air bubbles between the printing step and the cured product of the adhesive layer were evaluated according to the following criteria.

⊚: No air bubbles at the end ○: There are a few air bubbles at the end, but there is no problem in practical use △: There are air bubbles at the end, but there is no problem in practical use unless it is for special purposes ×: There is no problem in practical use at the end There are a remarkable number of bubbles in, and there is a problem in practical use.

(durability)
A sample for durability evaluation was prepared in the same manner as the above-mentioned evaluation sample for step followability. The obtained sample was subjected to the following test and visually evaluated in appearance (1) Treated at 85 ° C. for 500 hours (heating test).
(2) Treatment was performed for 500 hours in an atmosphere of 60 ° C. and a relative humidity of 95% RH (humidification test).
(3) After leaving for 30 minutes in an environment of 85 ° C., leaving for 30 minutes in an environment of -40 ° C. was defined as one cycle, and 300 cycles (300 hours) were processed in one cycle of 1 hour (heat shock (HS) test). ).

-Visual evaluation-
⊚: No air bubbles at the end ○: There are a few air bubbles at the end, but there is no problem in practical use △: There are air bubbles at the end, but there is no problem in practical use unless it is for special purposes ×: There is no problem in practical use at the end There are a remarkable number of bubbles in, and there is a problem in practical use.

(Haze after storage in a moist heat environment)
One PET film of the polarizing plate with an adhesive layer obtained in Examples and Comparative Examples was peeled off, and the exposed adhesive surface was roll-bonded to non-alkali glass (82 mm × 53 mm × thickness 0.5 mm). Next, the other PET film was peeled off, and non-alkali glass (82 mm × 53 mm × thickness 0.5 mm) was bonded using a roll. After that, an autoclave treatment (80 ° C., gauge pressure 0.2 MPa, 20 minutes) was applied to the finished product, and ultraviolet rays having a wavelength of 365 nm were irradiated using a metal halide lamp so ^{that the integrated light intensity was 2000 mJ / cm 2.} The pressure-sensitive adhesive sheet was cured to prepare a sample for evaluation.

The obtained evaluation sample is stored for 100 hours in an environment of 65 ° C. and a relative humidity of 90% RH, and then stored for 2 hours in an environment of 23 ° C. and a relative humidity of 50% RH at room temperature (25 ° C.). Then, the haze was measured according to JIS K7136 (2000) using a haze meter (NDH5000, manufactured by Nippon Denshoku Industries Co., Ltd.).

(Processing suitability)
The polarizing plate with an adhesive layer obtained in Examples and Comparative Examples was cut with a Thomson blade for curve processing and drilling using a Thomson punching machine while the PET film was laminated, and the shape of the end portion was formed. Observed. The number of sheets in which the edges were crushed, the glue was squeezed out, and the PET film was floated was counted, and evaluated according to the following evaluation criteria. ◎ ~ ○ pass.

-Evaluation criteria-
⊚: 0-9 sheets ○: 10-20 sheets ×: 21 sheets or more.

(Relative permittivity)
The (meth) acrylic acid ester copolymers obtained in Examples and Comparative Examples were placed between a polyethylene terephthalate (PET) film having a thickness of 125 μm and a release PET film having a thickness of 50 μm, and were subjected to a hot press at 100 ° C. Using a test piece obtained by forming a film with a thickness of 150 μm, the relative permittivity at a frequency of 100 kHz was measured by the following procedure.

The AGILENT Corp. IMPEDANCE ANALYZER4294A, connect the 1451B manufactured by the company, to measure the capacitance _{C B} of the specimen at a frequency 100kHz. _{The capacitance C C} of the PET film having a thickness of 125 μm and the _{capacitance C D} of the peeled PET film having a thickness of 50 μm were also measured, and the capacitance C _A of the test piece was calculated from the following formula (i).

(1 / C _B ) = (1 / C _A ) + (1 / _CC ) + (1 / C _D ) ... (i)
The relative permittivity εr of the test piece was calculated from the following formula (ii), and the value was used as the relative permittivity of the copolymer. The thickness of the test piece was measured with a micrometer.

_{C A = ε0 × εr × π} × (L / 2) 2 / d ··· (ii)
ε0: Permittivity of vacuum = 8.854 × ^10-12
L: Diameter of measuring electrode = 38 mm
d: Thickness of the adhesive layer.

<Adhesive strength>
The same evaluation sample as the evaluation sample used in the above durability test was newly prepared, cut into widths of 25 mm and length of 100 mm, respectively, and then autoclaved at 50 ° C. and 0.5 Mpa for 15 minutes to completely adhere to each other. I let you. Then, the sample was allowed to stand for 1 hour in an atmosphere of 23 ° C. and a relative humidity of 55% RH, and then the adhesive strength of the sample was measured.

For the adhesive strength, the evaluation sample was peeled off with a tensile tester (Tensilon Universal Material Tester, STA-1150, manufactured by Orientec Co., Ltd.) under the conditions of 23 ° C. and 55% RH relative humidity at a peeling angle of 180 °. It was determined by measuring the adhesive force (N / 25 mm) at the time of peeling according to the method of the adhesive tape and adhesive sheet test of JIS Z0237 (2009) at a speed of 300 mm / min.

The evaluation results are shown in Table 3 below.

From the results in Table 3 above, according to the pressure-sensitive adhesive composition of the present invention, it has good step followability, durability in a harsh environment (high temperature, high humidity, heat shock), and a wet heat durability test. It was found that a pressure-sensitive adhesive layer having excellent later haze, excellent processability and adhesive strength, and a low dielectric constant can be obtained.

1 Thin polarizing plate,
2 Polycarbonate film,
3 Polyvinyl alcohol adhesive,
4 Polarizer,
5 Polyvinyl alcohol adhesive,
6 Phase difference film.

Claims (23)

A pressure-sensitive adhesive composition for a photocurable optical film containing a main agent (A) and a chain transfer agent (B).
The main agent (A) contains a (meth) acrylic acid ester copolymer (a), and contains the (meth) acrylic acid ester copolymer (a).
The (meth) acrylic acid ester copolymer (a) is
(A1): A structural unit derived from a (meth) acrylic acid ester monomer having a linear or branched alkyl group having 1 to 14 carbon atoms and 15% by mass or more and 55% by mass or less.
(A2): A structural unit derived from a (meth) acrylic acid ester monomer having a cyclic alkyl group having 3 or more and 14 or less carbon atoms, which is 10% by mass or more and 55% by mass or less.
(A3): A constituent unit derived from a hydroxy group-containing (meth) acrylic acid ester monomer, 5% by mass or more and 35% by mass or less.
(A4): Structural unit derived from an amide group-containing monomer 5% by mass or more and 35% by mass or less.
(However, the total amount of the structural units derived from (a1) to (a4) is 100% by mass, and the content of the structural units derived from (a1) is derived from the structural units derived from (a1) and (a2). 20% by mass or more and 60% by mass or less with respect to the total amount with the constituent units)
Including
A pressure-sensitive adhesive composition for a photocurable optical film, wherein the content of the chain transfer agent (B) is 0.01 part by mass or more and 5 parts by mass or less with respect to 100 parts by mass of the main agent (A). The (meth) acrylic acid ester copolymer (a) has one radically polymerizable functional group other than the component (a1), the component (a2), the component (a3), and the component (a4). The pressure-sensitive adhesive composition for a photocurable optical film according to claim 1, further comprising a structural unit derived from the (meth) acrylic acid ester monomer (a5). The pressure-sensitive adhesive composition for a photocurable optical film according to claim 2, wherein the component (a5) contains a (meth) acrylic acid ester monomer having an aromatic hydrocarbon group. The pressure-sensitive adhesive composition for a photocurable optical film according to claim 2 or 3, wherein the component (a5) contains a (meth) acrylic acid ester monomer having a branched-chain alkyl group having 18 or more and 36 or less carbon atoms. thing. The content of the structural unit derived from the component (a5) is 10 parts by mass or more and 40 parts by mass or less with respect to 100 parts by mass of the total amount of the structural units derived from (a1) to (a4). The pressure-sensitive adhesive composition for a photocurable optical film according to any one of 4. The pressure-sensitive adhesive composition for a photocurable optical film according to any one of claims 1 to 5, wherein the component (a2) is at least one of isobonyl (meth) acrylate and cyclohexyl (meth) acrylate. The pressure-sensitive adhesive for a photocurable optical film according to any one of claims 1 to 6, wherein the glass transition temperature of the (meth) acrylic acid ester copolymer (a) is −40 ° C. or higher and lower than 20 ° C. Composition. The pressure-sensitive adhesive composition for a photocurable optical film according to any one of claims 1 to 7, further comprising a cross-linking agent (C). The pressure-sensitive adhesive for an optical film according to claim 8, wherein the cross-linking agent (C) is contained in an amount of 0.01 part by mass or more and 5 parts by mass or less with respect to 100 parts by mass of the main agent (A). The cross-linking agent (C) is at least one selected from the group consisting of an isocyanate compound, a carbodiimide compound, an oxazoline compound, an epoxy compound, a polyfunctional (meth) acrylic acid ester monomer, and a peroxide. Alternatively, the pressure-sensitive adhesive for an optical film according to 9. The adhesion for a photocurable optical film according to any one of claims 1 to 10, further containing 0.001 to 5 parts by mass of a silane coupling agent (D) with respect to 100 parts by mass of the main agent (A). Agent composition. The pressure-sensitive adhesive composition for a photocurable optical film according to any one of claims 1 to 11, further comprising a high softening point resin (E). The pressure-sensitive adhesive composition for a photocurable optical film according to claim 12, wherein the high softening point resin (E) is a rosin ester-based resin. A pressure-sensitive adhesive layer for a photocurable optical film, which is formed from the pressure-sensitive adhesive composition for a photocurable optical film according to any one of claims 1 to 13. The pressure-sensitive adhesive layer for a photocurable optical film according to claim 14, wherein the weight average molecular weight is 50,000 or more and 1,000,000 or less. The pressure-sensitive adhesive layer for a photocurable optical film according to claim 14 or 15, which has a thickness of 20 μm or more and 1 mm or less. The cured product of the pressure-sensitive adhesive layer for a photocurable optical film according to any one of claims 14 to 16.
A first optical film provided on one surface of the cured product of the pressure-sensitive adhesive layer and
An optical member having. 17. The optical member described. The optical member according to claim 17 or 18, further comprising at least one easy-adhesion-treated layer between the first optical film and the cured product of the pressure-sensitive adhesive layer for a photocurable optical film. The easy-adhesion-treated layer has a first easy-adhesion-treated layer and a second easy-adhesion-treated layer.
The optical member is claimed to have a cured product of the first optical film, the first easy-adhesion-treated layer, the second easy-adhesion-treated layer, and the pressure-sensitive adhesive layer for an optical film laminated in this order. Item 19. The optical member according to Item 19. An image display device using at least one optical member according to any one of claims 18 to 20. The pressure-sensitive adhesive composition for a photocurable optical film according to any one of claims 1 to 13 is applied onto the peeled surface of the first release sheet to form a coating film, and the second Laminating step of laminating so that the peeled surface of the release sheet of No. 1 is in contact with the surface of the coating film.
An active energy ray irradiation step of irradiating a coating film with an active energy ray via at least one of the first release sheet and the second release sheet.
A method for producing an adhesive layer for a photocurable optical film. The method for producing an adhesive layer for a photocurable optical film according to claim 22, wherein the integrated light amount of the active energy rays is 300 mJ / cm ² or more and 2000 mJ / cm ^{2 or less.}

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