JP6859092B2 - Composition for easy adhesive layer formation - Google Patents

Description

In the present invention, a composition for forming an easy-adhesive layer for forming an easy-adhesive layer on a base material made of an acrylic resin, and an easy-adhesive layer formed of the composition on a base material made of an acrylic resin. An easily adhesive base material contained in the above, a polarizing plate having a laminated unit in which a base material made of an acrylic resin and a polarizer are laminated via an easily adhesive layer formed of the composition, and this polarizing plate. Regarding the provided image display device.

Acrylic resins containing (meth) acrylic polymers typified by polymethyl methacrylate (PMMA) are excellent in optical properties such as light transmittance, and are also excellent in balance of mechanical strength, molding processability, surface hardness and the like. For this reason, acrylic resin is widely used as a transparent material in various industrial products such as automobiles and home appliances.
In recent years, the number of cases where acrylic resin is used for optical-related applications is increasing, and in particular, it is incorporated into image display devices such as liquid crystal display devices (LCD), plasma display panels (PDP), and organic EL display devices (OELD). Acrylic resins are being applied to optical films. Among the acrylic resins, the acrylic resin having a ring structure is used for an optical film from the viewpoint of transparency and heat resistance.

The optical film may be used in a laminated state with other functional films. For example, a polarizer protective film, which is a type of optical film, is usually used in an image display device in the state of a polarizing plate laminated with a polarizer. The polarizing plate usually has a configuration including a polarizing element and a polarizer protective film bonded to at least one surface of the polarizing element with an adhesive.

When an acrylic resin is used for an optical film, an easy-adhesion layer may be formed on the surface of the optical film in consideration of lamination with another functional film. The easy-adhesive layer is a layer that improves the adhesiveness of the optical film and ensures the lamination with another film via the adhesive layer.
Patent Document 1 discloses a polarizing plate including a polarizing element and a polarizer protective film bonded to at least one surface of the polarizing element with an adhesive. Further, Patent Document 1 discloses a polarizing plate in which an easy-adhesion layer containing a polyurethane resin and / or an amino group-containing polymer is formed on a surface of the polarizing element protective film facing the polarizer.

By the way, in recent years, with the miniaturization and thinning of liquid crystal display devices and the like, optical films are often exposed to high temperature and high humidity environments.
Patent Document 2 describes that an easy-adhesive layer is formed of an easy-adhesive composition containing a urethane resin having a carboxyl group and a cross-linking agent, and has excellent adhesion between a polarizing element and a polarizing element protective film in a high-temperature and high-humidity environment. The polarizing plate is disclosed. However, Patent Document 2 does not disclose a specific combination of a film formed of an acrylic resin having a ring structure and an easy-adhesion layer formed of an easy-adhesion composition containing an epoxy compound.

JP-A-2007-127893 Japanese Unexamined Patent Publication No. 2009-193061

An object of the present invention is to provide a composition for forming an easy-adhesive layer capable of forming an easy-adhesive layer (adhesive layer, adhesive layer) on a base material (base film) made of an acrylic resin having a ring structure. There is.
Another object of the present invention is an easy-adhesion layer having excellent adhesiveness (furthermore, excellent adhesiveness even under high temperature and high humidity) on a substrate made of an acrylic resin having a ring structure. The present invention is to provide a composition for forming an easy-adhesive layer.
Still another object of the present invention is an easy-adhesive base material in which an easy-adhesive layer formed of such a composition for forming an easy-adhesive layer is formed on a base material made of an acrylic resin having a ring structure. To provide (adhesive film).
Still another object of the present invention is that a base material made of an acrylic resin having a ring structure and a polarizer are laminated via an easy-adhesion layer formed of such an easy-adhesion layer forming composition. An object of the present invention is to provide a polarizing plate (polarizing film) having a laminated unit.
Still another object of the present invention is to provide an image display device provided with such a polarizing plate.

As a result of intensive research to solve the above problems, the present inventors have made a base material composed of an acrylic resin having a ring structure in the main chain (or may be simply referred to as an "acrylic resin base material"). By forming the easy-adhesion layer with the composition for forming the easy-adhesion layer containing the polyurethane resin (A) having a carboxyl group and the epoxy compound (B) on the top, the adhesiveness is excellent even under high temperature and high humidity. It was also found that an easily adhesive base material can be obtained.

That is, the present invention relates to the following composition for forming an easy-adhesion layer and the like.
[1] A composition for forming an easy-adhesive layer on a base material made of an acrylic resin having a ring structure in the main chain, which is a polyurethane resin (A) having a carboxyl group and an epoxy compound (B). A composition for forming an easy-adhesive layer containing and.
[2] The composition according to the above [1], wherein the ring structure has at least one structure selected from a maleic anhydride structure, a maleimide structure, a glutaric anhydride structure, a glutarimide structure, a lactam ring structure, and a lactone ring structure. Stuff.
[3] The composition according to the above [1] or [2], wherein the epoxy compound (B) contains an aliphatic epoxy compound.
[4] The composition according to any one of [1] to [3] above, wherein the epoxy compound (B) satisfies an epoxy equivalent of 200 g / equivalent or less and a viscosity of 2000 mPa · s or less.
[5] The composition according to any one of [1] to [4] above, wherein the epoxy compound (B) contains an aliphatic polyol polyglycidyl ether and satisfies an epoxy equivalent of 170 g / equivalent or less.
[6] The above-mentioned [1] to [5], wherein the ratio of the polyurethane resin (A) to the epoxy compound (B) is the former / the latter (weight ratio) = 99/1 to 10/90. Composition.
[7] A base material made of an acrylic resin having a ring structure in the main chain and an easy-adhesion layer formed on the base material with the composition according to any one of [1] to [6] above. Easy-adhesive substrate including.
[8] The adhesive base material according to the above [7], wherein the thickness ratio of the base material to the easy-adhesion layer is the former / the latter = 1 / 0.1 / 1 / 0.001.
[9] The adhesive substrate according to the above [7] or [8] for optics.
[10] The adhesive base material according to any one of the above [7] to [9] for adhering to a polarizer.
[11] A base material made of an acrylic resin having a ring structure in the main chain and a polarizer are formed via an easy-adhesion layer formed of the composition according to any one of [1] to [6] above. A polarizing plate having a laminated stacking unit.
[12] An image display device provided with the polarizing plate according to the above [11].

According to the present invention, it is possible to provide a composition for forming an easy-adhesion layer capable of forming an easy-adhesion layer on a base material made of an acrylic resin having a ring structure.
Further, according to the present invention, an easy-adhesive layer having excellent adhesiveness (furthermore, excellent adhesiveness even under high temperature and high humidity) on a base material made of an acrylic resin having a ring structure. A composition for forming an easy-adhesive layer can be provided. Since such an easy-adhesion layer has excellent adhesion to other functional films, the adhesion to the polarizer is not impaired even under high temperature and high humidity.
Further, according to the present invention, the easy-adhesive layer formed of such an easy-adhesive layer forming composition is formed on a base material made of an acrylic resin having a ring structure. Can be provided.
Further, according to the present invention, a base material made of an acrylic resin having a ring structure and a polarizing element are laminated via an easy-adhesion layer formed of such an easy-adhesion layer forming composition. A polarizing plate having a unit and an image display device provided with such a polarizing plate can be provided.

Hereinafter, the present invention will be described in detail.
The composition for forming an easy-adhesive layer of the present invention is for forming an easy-adhesive layer (adhesive layer, adhesive layer) on a base material (base film) made of an acrylic resin having a ring structure in the main chain. It is a composition. The composition for forming an easy-adhesion layer of the present invention contains a polyurethane resin (A) having a carboxyl group and an epoxy compound (B).

[Polyurethane resin (A)]
The polyurethane resin (A) usually has a carboxyl group.
Further, the polyurethane resin (A) may contain one or more reactive groups (for example, hydroxyl groups, amino groups, etc.) for epoxy groups other than the carboxyl group.

The polyurethane resin (A) may be, for example, a structural unit derived from the polyisocyanate compound (I) (or simply referred to as a “polyisocyanate compound (I) unit”; the same shall apply hereinafter in the same expression) and a polyol ( II) A resin having a unit can be used. The polyurethane resin (A) may have units other than the polyisocyanate compound (I) unit and the polyol (II) unit (for example, carboxylic acid unit, amine unit, etc.).
Examples of the polyurethane resin (A) include a polyacrylic polyurethane resin, a polyether polyurethane resin, and a polyester polyurethane resin. The polyurethane resin may be used alone or in combination of two or more.

The polyisocyanate compound (I) is not particularly limited as long as it has two or more isocyanate groups.
Examples of the polyisocyanate compound (I) include polyisocyanates (for example, aliphatic polyisocyanates, alicyclic polyisocyanates, aromatic aliphatic polyisocyanates, aromatic polyisocyanates, etc.) and modified polyisocyanates [or derivatives, for example. , Multimers (dimeric, trimeric, etc.), carbodiimide, biuret, allophanate, uretdione, polyamine modified, etc.] and the like. The polyisocyanate compound (I) may be used alone or in combination of two or more.

The aliphatic polyisocyanate is not particularly limited, but is, for example, an aliphatic diisocyanate [for example, alcandiisocyanate (for example, tetramethylene diisocyanate, hexamethylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, dodecamethylene diisocyanate, lysine diisocyanate). , 2-Methylpentane-1,5-diisocyanate, C _{2-20 alcandiisocyanate} such as 3-methylpentane-1,5-diisocyanate, preferably C _4-12 alcandiisocyanate)], having 3 or more isocyanate groups. Examples thereof include aliphatic polyisocyanates (for example, aliphatic tri-hexamethylene such as 1,4,8-triisocyanatooctane).

_{The alicyclic polyisocyanate is not particularly limited, but is, for example, an alicyclic diisocyanate {for example, C 5-8} cycloalcandiisocyanate such as methyl-2,4- or 2,6-cyclohexanediisocyanate (for example, methyl-2,4- or 2,6-cyclohexanediisocyanate). _{, Etc.), isocyanatoalkylcycloalcanisocyanate [eg, isocyanato C 1-6alkyl} C _5-10 cycloalcanisocyanate such as 3-isocyanatomethyl-3,5,5-trimethylcyclohexylisocyanate (isophoronediisocyanate, IPDI)] , Di (isocyanatoalkyl) cycloalkane [eg di (isocyanato C _1-6 alkyl) C _5-10 cycloalcan such as hydrogenated xylylene diisocyanate], di (isocyanatocycloalkyl) alkane [eg hydrogenated diphenylmethane _{Bis (isocyanato C 5-10} cycloalkyl) C _1-10 alcan, etc. such as -4,4'-diisocyanate (4,4'-methylenebiscyclohexylisocyanate)], polycycloalkanediisocyanate (norbornandiisocyanate, etc.)}, Examples thereof include alicyclic polyisocyanates having three or more isocyanate groups (for example, alicyclic tri-hexaisocyanates such as 1,3,5-triisocyanatocyclohexane).

The aromatic aliphatic polyisocyanate is not particularly limited, but for example, aromatic aliphatic diisocyanate {for example, di (isocyanatoalkyl) areocyanate [for example, xylylene diisocyanate (XDI), tetramethylxylylene diisocyanate (TMXDI) (1, _{Bis (isocyanato C 1-6} alkyl) C _6-12 allenes such as 3- or 1,4-bis (1-isocyanato-1-methylethyl) benzene)}}, aromatic aliphatics having 3 or more isocyanate groups Polyisocyanate (for example, aromatic aliphatic tri to hexaisocyanate, etc.) and the like can be mentioned.

The aromatic polyisocyanate is not particularly limited, but is, for example, aromatic diisocyanate {for example, allene diisocyanate [for example, o-, m- or p-phenylenediocyanate, chlorophenylenediocyanate, tolylene diisocyanate, naphthalenedi isocyanate (NDI), etc. C _6-12 areocyanate diisocyanate, etc.], di (isocyanatoaryl) alkane [for example, diphenylmethane diisocyanate (MDI) (2,4'-diphenylmethane diisocyanate, 4,4'-diphenylmethane diisocyanate, etc.), trizine diisocyanate, etc. Isocyanato C _6-10 aryl) C _1-10 alkane, etc.] Aromatic polyisocyanates having 3 or more isocyanate groups (eg, 4,4'-diphenylmethane-2,2', 5,5'-tetraisocyanate, etc. Aromatic tri to hexaisocyanate, etc.) and the like.

Among the polyisocyanate compounds (I), diisocyanate compounds (for example, aliphatic diisocyanates, alicyclic diisocyanates, aromatic aliphatic diisocyanates, aromatic diisocyanates, etc.) are often used.

The polyol (II) is not particularly limited as long as it has two or more hydroxyl groups.
Examples of the polyol (II) include polyacrylic polyol, polyester polyol, polyether polyol, polyurethane polyol and the like. The polyol (II) may be used alone or in combination of two or more.

Examples of the polyacrylic polyol include a copolymer having a (meth) acrylic acid ester unit and a unit derived from a component having a hydroxyl group (a component unit having a hydroxyl group). The polyacrylic polyol may have a unit other than the (meth) acrylic acid ester unit and the component unit having a hydroxyl group.

The (meth) acrylic acid ester is not particularly limited, and for example, an aliphatic (meth) acrylate [for example, (meth) acrylic acid alkyl ester (for example, methyl (meth) acrylic acid, ethyl (meth) acrylic acid, ( (Meta) Acrylic Acid C _1-18 Alkyl such as butyl acrylate)], alicyclic (meth) acrylate [eg, (meth) acrylic acid cycloalkyl ester (eg, (meth) acrylic acid cyclopropyl, _{C 3-20} cycloalkyl acrylates such as cyclobutyl (meth) acrylate), crosslinked (meth) acrylates (eg isobornyl (meth) acrylate)], aromatic (meth) acrylates [eg (meth) Acrylic acid aryl ester (eg, (meth) acrylic acid phenyl, (meth) acrylic acid o-tolyl and other (meth) acrylic acid C _6-20 aryl), (meth) acrylic acid aralkyl ester (eg, (meth) acrylic _{C 6-10aryl} C _1-4 alkyl (meth) acrylates such as benzyl acid, phenoxyalkyl (meth) acrylates (eg, phenoxy C _{1-4 (meth) acrylates such as phenoxyethyl (meth) acrylates)} Alkyl) etc.] and the like. These may be used alone or in combination of two or more.

The component (monomer) having a hydroxyl group is not particularly limited, and is, for example, a (meth) acrylate hydroxyalkyl ester [for example, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate. , (Meta) Acrylic Acid 3-Hydroxypropyl, (Meta) Acrylic Acid 2-Hydroxybutyl, (Meta) Acrylic Acid 4-Hydroxybutyl, (Meta) Acrylic Acid 2-Hydroxypentyl, etc. (Meta) Acrylic Acid Hydroxy C _{1 -18alkyl,} etc.], (meth) acrylic acid monoesters of polyhydric alcohols (eg, glycerin, trimethylolpropane, etc.) and the like. These may be used alone or in combination of two or more.

Examples of the polyester polyol include a copolymer having a polyvalent carboxylic acid component unit and a polyol component unit. The polyester polyol may have a unit other than the multivalent carboxylic acid component unit and the polyol component unit.

The polyvalent carboxylic acid component is not particularly limited, but is, for example, a dicarboxylic acid [for example, an aromatic dicarboxylic acid (for example, C _6-12 arenedicarboxylic acid such as orthophthalic acid, isophthalic acid, terephthalic acid, etc.), an alicyclic group. _{Dicarboxylic acids (eg, C 5-10} cycloalkandicarboxylic acids such as hexahydrophthalic acid, tetrahydrophthalic acid, 1,3-cyclohexanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid), aliphatic dicarboxylic acids (eg, oxalic acid). _{, C 2-20} alkanedioic acids such as succinic acid, malonic acid, glutaric acid, adipic acid, pimelli acid, suberic acid, azelaic acid, sebacic acid, decandicarboxylic acid, dodecandicarboxylic acid, octadecanediocarboxylic acid)]. Examples thereof include acid anhydrides of dicarboxylic acids and lower alcohol esters of these dicarboxylic acids. These may be used alone or in combination of two or more.

The polyol component is not particularly limited, but is, for example, a dihydric alcohol {for example, an aliphatic diol [for example, an alkanediol (for example, ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,3-propanediol). Butanediol, 1,4-butanediol, neopentyl glycol, pentandiol, 1,6-hexanediol, 1,8-octanediol, C _{2-12 alcandiol} such as 1,10-decanediol), polyalkylene _{Glycols (eg, C 2-12} alkylene glycols such as diethylene glycol, triethylene glycol, dipropylene glycol _{), alicyclic diols [eg, C 5-10} cycloalkanes such as cycloalcandiols (eg, 1,4-cyclohexanediol) Diols, etc.), hydrogenated bisphenols (eg, hydrogenated bisphenol A, hydrogenated bisphenol F, etc.)], aromatic diols [eg, dihydroxy C _{6- such as dihydroxyarene (eg, o-, m- or p-dihydroxybenzene) 12} arenes, etc.), bisphenol (eg, bisphenol A, bisphenol F, etc.)]} and the like. These may be used alone or in combination of two or more.

Examples of the polyether polyol include a copolymer obtained by adding an alkylene oxide to a polyhydric alcohol.
The polyhydric alcohol is not particularly limited, and for example, the above-mentioned dihydric alcohol can be used. The polyhydric alcohol may be used alone or in combination of two or more.
The alkylene oxide is not particularly limited, and examples _{thereof include C 2-12} alkylene oxides such as ethylene oxide, propylene oxide, and butylene oxide. The alkylene oxide may be used alone or in combination of two or more.

Examples of the polyurethane polyol include a copolymer having a polyisocyanate compound unit and a polyol component unit. The polyurethane polyol may have a unit other than the polyisocyanate compound unit and the polyol component unit.

In the polyurethane polyol, the polyisocyanate compound from which the polyisocyanate compound unit is derived is not particularly limited, and for example, the polyisocyanate compound (I) that can be used in the polyurethane resin (A) may be used. The polyisocyanate compound may be used alone or in combination of two or more.

In the polyurethane polyol, the polyol component from which the polyol component unit is derived is not particularly limited, but for example, the polyol (II) that can be used in the polyurethane resin (A) (for example, a polyacrylic polyol, a polyester polyol, a polyether polyol, etc.). Etc. may be used. The polyol component may be used alone or in combination of two or more.

The polyurethane resin (A) may contain a chain extender as a constituent component (or may have a structural unit derived from the chain extender).
The chain extender is not particularly limited, and is, for example, glycols (for example, C _2-6 alkanediol such as ethylene glycol, 1,4-butanediol, neopentyl glycol, 1,6-hexanediol), and polyvalent. _{Using common chain extenders such as alcohols (eg C 2-6} alkanetris to hexaols such as glycerin, trimethylolpropane, pentaerythritol), diamines (eg ethylenediamine, hexamethylenediamine, etc.) Good.
Further, in addition to a general chain extender, a chain extender having a carboxyl group described later may be used.

In the polyurethane resin (A), the content form of the carboxyl group is not particularly limited, and the carboxyl group may be contained in the monomer-derived unit such as the polyisocyanate compound (I) unit and the polyol (II) unit.
Further, in the polyurethane resin (A), the carboxyl group may be contained in the unit derived from the chain extender.

The method for producing the polyurethane resin (A) is not particularly limited as long as it reacts the polyisocyanate compound (I) with the polyol (II). Further, a chain extender may be used in the production of the polyurethane resin (A).
When a carboxyl group is introduced into the polyurethane resin (A) by a chain extender, the chain extender includes, for example, dihydroxycarboxylic acid [for example, dimethylol alkanoic acid (for example, dimethylol acetic acid, dimethylol butanoic acid, dimethylol propionic acid). _{, Dimethylol C 2-10} alkane carboxylic acid such as dimethylol butyric acid and dimethylol pentanoic acid, preferably C _2-8 alkane carboxylic acid)] and other chain extenders having a carboxyl group may be used.

The number average molecular weight of the polyurethane resin (A) is not particularly limited, but may be, for example, 5,000 to 1,000,000, preferably 5,000 to 600,000, and more preferably about 10,000 to 400,000. The number average molecular weight may be a value obtained by polystyrene conversion using gel permeation chromatography.
The acid value of the polyurethane resin (A) is not particularly limited, but may be, for example, 10 mgKOH / g or more, preferably 10 to 50 mgKOH / g, and more preferably about 20 to 45 mgKOH / g.

[Epoxy compound (B)]
The epoxy compound (B) usually contains a compound having two or more (eg, 2-6, preferably 2-4, more preferably 2-3) epoxy groups.

The compound having two or more epoxy groups is not particularly limited, and examples thereof include an aliphatic epoxy compound, an alicyclic epoxy compound, and an aromatic epoxy compound.

Examples of the aliphatic epoxy compound include aliphatic polyol polyglycidyl ether [for example, chain aliphatic polyol polyglycidyl ether (for example, alkane polyol polyglycidyl ether, polyalkane polyol polyglycidyl ether, etc.)] and the like.

Examples of the alkane polyol polyglycidyl ether include alkanediol polyglycidyl ether [for example, alkylene glycol diglycidyl ether (for example, ethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, neopentyl glycol diglycidyl ether, 1,6-hexane). _{C 2-10} alcan diol diglycidyl ether such as diol diglycidyl ether), alcantry to hexaol polyglycidyl ether {eg, glycerin polyglycidyl ether (eg, glycerinji or triglycidyl ether), pentaerythritol polyglycidyl ether, _{C 2-10} alcantry to hexaol polysidyl ether such as sorbitol polyglycidyl ether and trimethylpropan polyglycidyl ether}] and the like can be mentioned.

Examples of the polyalcan polyol polyglycidyl ether include polyalcandiol polyglycidyl ether [for example, polyalkylene glycol diglycidyl ether {for example, polyethylene glycol diglycidyl ether (for example, diethylene glycol diglycidyl ether), polypropylene glycol diglycidyl ether and the like. Poly C _2-4 alkylene glycol diglycidyl ether, etc.}], polyalcantry to tetraolpolyglycidyl ether {for example, diglycerin polyglycidyl ether (eg, diglycerindi or triglycidyl ether, etc.), dipentaerythritol polyglycidyl ether, etc. C _6-12 polyalcantry to tetraolpolyglycidyl ether, etc.} and the like. In the polyalkane polyol polyglycidyl ether, the number of alkane polyols is not particularly limited, and may be, for example, 2 to 15, preferably 2 to 12, and more preferably about 2 to 10. When the number of alkane polyols is not too large (for example, 15 or less), the adhesiveness of the easy-adhesion layer is excellent, which is preferable.

Examples of the alicyclic epoxy compound include polyglycidyl ethers of polyhydric alcohols having at least one alicyclic ring [for example, cycloalkane polyol polyglycidyl ether (for example, C _5-8 cycloalkanediol diglycidyl ether and the like). C _5-8 cycloalkane polyol polyglycidyl ether), polyglycidyl ether of hydrogenated bisphenols (for example, hydrogenated bisphenol such as hydrogenated bisphenol A and hydrogenated bisphenol F)] and the like.

Examples of the aromatic epoxy compound include polyglycidyl ethers of polyhydric phenols having at least one aromatic ring [for example, polyglycidyl ethers of bisphenols (for example, bisphenols such as bisphenol A and bisphenol F), novolac type. Epoxy resin, etc.] and the like.

As described above, the epoxy compound (B) usually contains a compound having two or more epoxy groups, but may contain a compound having one epoxy group.

The number of epoxy groups in the epoxy compound (B) is usually 2 or more on average (for example, 2 to 6, preferably 2 to 4, and more preferably 2 to 3). When the number of epoxy groups is not too large (for example, 6 or less), the cross-linking reaction proceeds sufficiently and the adhesiveness of the easy-adhesion layer is excellent, which is preferable.

The epoxy compound (B) can be used alone or in combination of two or more.
The epoxy compound (B) preferably contains an aliphatic epoxy compound, more preferably contains an aliphatic polyol polyglycidyl ether, and further preferably contains an arcandi to hexaol polyglycidyl ether and a polyalkandi to tetraol polyglycidyl ether. preferable.

The epoxy equivalent of the epoxy compound (B) is not particularly limited, but in the present invention, for example, 200 g / equivalent or less (for example, 100 to 180 g / equivalent), preferably 170 g / equivalent or less (for example, 110 to 160 g / equivalent). More preferably, a compound having a relatively small epoxy equivalent of about 150 g / equivalent or less (for example, 120 to 150 g / equivalent) may be preferably used. When the epoxy equivalent is not too large (for example, 200 g / equivalent or less), the cross-linking reaction proceeds sufficiently and the adhesiveness of the easy-adhesion layer is excellent, which is preferable.

The viscosity of the epoxy compound (B) is not particularly limited, but is, for example, 2000 mPa · s or less (for example, 0.1 to 1800 mPa · s), preferably 1500 mPa · s or less (for example, 1-1300 mPa · s), more preferably. It may have a relatively low viscosity of about 1000 mPa · s or less (for example, 5 to 800 mPa · s). When the viscosity is not too high (for example, 2000 mPa · s or less), the cross-linking reaction proceeds sufficiently and the adhesiveness of the easy-adhesion layer is excellent, which is preferable.

The number of atoms in the longest atomic chain of the epoxy compound (B) is, for example, 3 to 15 (for example, 4 to 14), preferably 5 to 13 (for example, 6 to 12), and more preferably 7 to 11 (for example, 8 to 8 to). It may be about 10). Within the above range, the crosslink density becomes high, and the adhesiveness of the easy-adhesion layer can be improved.
Here, the longest atomic chain of the epoxy compound (B) indicates the longest atomic chain among the total number of atoms (for example, carbon atom, oxygen atom, etc.) constituting the chain structure connecting the two epoxy groups. , The total number of atoms constituting the longest atomic chain is called the number of atoms in the longest atomic chain.

[Composition for forming an easy-adhesive layer]
The composition for forming an easy-adhesion layer may contain a polyurethane resin (A) and an epoxy compound (B), and may further contain one or more other components (for example, additives). ..
The additive is not particularly limited, and is, for example, an antiblocking agent, a dispersion stabilizer, a rocking agent, an antioxidant, an ultraviolet absorber, an antifoaming agent, a thickener, a dispersant, a surfactant, a catalyst, and a lubricant. , Antistatic agent and the like. Among the additives, it is preferable to include a blocking inhibitor. As the blocking inhibitor, for example, silica fine particles or the like may be used.

The particle size (average primary particle size) of the blocking inhibitor may be, for example, about 1 to 500 nm from the viewpoint of improving adhesiveness. The blocking inhibitor preferably contains particles having a relatively small particle size of about 1 to 250 nm, preferably 3 to 200 nm, and more preferably 5 to 150 nm. The blocking inhibitor may contain particles having a relatively small particle size at least, and may contain particles having a relatively large particle size (for example, about 250 to 500 nm). The average primary particle size of the anti-blocking agent can be determined by a laser diffraction / scattering type particle size distribution measuring device (for example, Submicron Particle Sizer NICOMP380 manufactured by Particle Sigmas Systems).

When the blocking inhibitor contains particles having a relatively small particle size (for example, 1 to 250 nm) and particles having a relatively large particle size (for example, 250 to 500 nm), from the viewpoint of improving adhesiveness and blocking resistance, etc. The former / latter (weight ratio) may be, for example, 1/1 to 500/1, preferably 2/1 to 300/1, and more preferably 3/1 to 100/1.

The content ratio of the polyurethane resin (A) in the composition for forming an easy-adhesive layer is not particularly limited, but is, for example, 1 to 20% by weight, preferably 1.5 to 15% by weight, and more preferably about 2 to 12% by weight. It may be.

The content ratio of the epoxy compound (B) in the composition for forming an easy-adhesion layer is not particularly limited, but is, for example, 1 to 10% by weight, preferably 0.2 to 8% by weight, and more preferably 0.3 to 6% by weight. It may be about%.

The ratio of the polyurethane resin (A) to the epoxy compound (B) in the composition for forming an easy-adhesive layer is not particularly limited, but the former / latter (weight ratio) is, for example, 99/1 to 10/90. It may be preferably about 95/5 to 30/70, more preferably about 90/10 to 50/50. Within the above range, the crosslinking reaction proceeds sufficiently, and the adhesiveness of the easy-adhesion layer can be improved.

In the composition for forming an easy-adhesion layer, the content ratio of the additive is not particularly limited, but is, for example, 0.1 to 30 parts by weight (for example, 0.1 to 30 parts by weight) with respect to 100 parts by weight of the total amount of the polyurethane resin (A) and the epoxy compound (B). For example, it may be about 1 to 25 parts by weight), preferably about 1 to 20 parts by weight (for example, 5 to 15 parts by weight).

In particular, in the composition for forming an easy-adhesive layer, the content ratio of the blocking inhibitor is not particularly limited, but is, for example, 0.1 to 30 with respect to 100 parts by weight of the total amount of the polyurethane resin (A) and the epoxy compound (B). It may be about 1 to 25 parts by weight (for example, 1 to 25 parts by weight), preferably about 1 to 20 parts by weight (for example, 5 to 15 parts by weight).
Further, in the composition for forming an easy-adhesion layer, the content ratio of the blocking inhibitor is, for example, 1 to 50% by weight, preferably 2 to 40% by weight, more preferably 3 from the viewpoint of improving adhesiveness and blocking resistance. It may be about 30% by weight. In particular, when particles having a relatively large particle size (for example, 250 to 500 nm) are contained, particles having a large particle size may be contained in an amount of about 0.1 to 1% by weight.

The form of use of the composition for forming an easy-adhesion layer is not particularly limited, but may be, for example, an aqueous system (for example, an aqueous dispersion type (emulsion or the like), a water-soluble type, etc.), a solvent system, or the like, and is preferably an aqueous system. .. In the case of an aqueous system, the environmental load generated when forming the easy-adhesion layer is smaller and the workability is excellent as compared with the solvent system.

The solvent is not particularly limited, but is, for example, aromatic hydrocarbons (for example, toluene, xylene, etc.), ketones (for example, acetone, methyl ethyl ketone, methyl isobutyl ketone), esters (for example, ethyl acetate, butyl acetate, etc.). ), Alcohols (for example, n-butyl alcohol, isopropyl alcohol, etc.) and the like.

When the composition for forming an easy-adhesion layer is used in an aqueous manner, a solvent (for example, ketones, alcohols, etc.) may be used in addition to water.

When the composition for forming an easy-adhesion layer is water-based or solvent-based, the solid content concentration in the liquid may be, for example, about 1 to 50% by mass, preferably about 5 to 30% by mass.

[acrylic resin]
The acrylic resin is not particularly limited as long as it has a ring structure in the main chain.
Acrylic resins usually have (meth) acrylic acid ester units.

The (meth) acrylic acid ester unit is not particularly limited, but is, for example, an aliphatic (meth) acrylate [for example, (meth) acrylic acid alkyl ester (for example, methyl (meth) acrylic acid, ethyl (meth) acrylic acid, _{(Meta) acrylate C 1-18} alkyl such as (meth) butyl acrylate], alicyclic (meth) acrylate [eg, (meth) acrylate cycloalkyl ester (eg, (meth) acrylate cyclopropyl) _{, (Meta) acrylic acid C 3-20} cycloalkyl such as (meth) acrylic acid cyclobutyl), crosslinked cyclic (meth) acrylate (eg, (meth) acrylic acid isobornyl), etc.], aromatic (meth) acrylate [eg , (Meta) acrylic acid aryl ester (eg, (meth) acrylic acid phenyl, (meth) acrylic acid o-tolyl and other (meth) acrylic acid C _6-20 aryl), (meth) acrylic acid aralkyl ester (eg,) _{C 6-10aryl} C _1-4 alkyl (meth) acrylate such as benzyl (meth) acrylate), phenoxyalkyl (meth) acrylate (eg, phenoxy (meth) acrylate such as phenoxyethyl (meth) acrylate) C _1-4 alkyl), etc.] and other units derived from (meth) acrylic acid ester can be mentioned. These may have one kind or two or more kinds.

Among the (meth) acrylic acid ester units, from the viewpoint of improving transparency and the like, it is preferable to contain at least an alkyl methacrylate ester unit, and it is more preferable to contain at least a _{C 1-18 alkyl methacrylate unit, and methacrylic acid.} It is more preferred to contain at least methyl units.

The content ratio of the methacrylic acid alkyl ester unit in the (meth) acrylic acid ester unit is, for example, 50 to 95% by mass, preferably 70 to 90% by mass. The content ratio of the methacrylic acid alkyl ester unit in the (meth) acrylic acid ester unit is, for example, 50 to 95 mol%, preferably 70 to 90 mol% in terms of the monomer constituting the (meth) acrylic acid ester unit. is there.

Examples of the ring structure include a cyclic imide structure (for example, maleimide structure, glutarimide structure, etc.), a cyclic anhydride structure (for example, maleic anhydride structure, glutaric anhydride structure, etc.), a lactam structure, a lactone ring structure, and the like. is there.
The ring structure is at least one selected from a maleic anhydride structure, a (N-substituted) maleimide structure, a glutaric anhydride structure, a glutarimide structure, a lactam structure, and a lactone ring structure from the viewpoint of heat resistance and optical properties. It is preferable to have the structure of.
The acrylic resin may have one or more of these ring structures.

The glutarimide structure and the glutaric anhydride structure are, for example, structures represented by the following formula (1).

（式中、Ｒ¹およびＲ²は、それぞれ独立して、水素原子またはアルキル基であり、Ｒ^３は水素原子又は置換基であり、Ｘ^１は酸素原子又は窒素原子である。Ｘ^１が酸素原子のときｎ＝０であり、Ｘ^１が窒素原子のときｎ＝１である。）

(In the formula, R ¹ and R ² are independently hydrogen atoms or alkyl groups, R ³ is a hydrogen atom or a substituent, X ¹ is an oxygen atom or a nitrogen atom, and X ¹ is oxygen. When it is an atom, n = 0, and when X ¹ is a nitrogen atom, n = 1.)

^{In R 1} and R ² of the formula (1), as the alkyl group, for example, a C _1-8 alkyl group (for example, a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, etc. Examples thereof include tert-butyl group, n-pentyl group, isopentyl group, n-hexyl group, isohexyl group, n-heptyl group, isoheptyl group, n-octyl group, 2-ethylhexyl group, etc.). Is not limited to such examples. Among R ¹ and R ² _{, a hydrogen atom or a C 1-4} alkyl group is preferable from the viewpoint of obtaining a film having excellent heat resistance and a small birefringence.

^{In R 3} of the formula (1), examples of the substituent include a hydrocarbon group and the like.
Examples of the hydrocarbon group include an aliphatic group, an alicyclic group, and an aromatic group. The hydrocarbon group may further have a substituent such as halogen.

^{In R 3} of the formula (1), as the aliphatic group, for example, a C _1-10 alkyl group (for example, a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, tert- Butyl group, n-pentyl group, isopentyl group, n-hexyl group, isohexyl group, n-heptyl group, isoheptyl group, n-octyl group, 2-ethylhexyl group, etc.) can be mentioned. It is not limited to such an example. _{Among these alkyl groups, a C 1-4} alkyl group is preferable, and a methyl group is more preferable, from the viewpoint of obtaining a film having excellent heat resistance and a small birefringence.

^{In R 3} of the formula (1), examples of the alicyclic group include a C _3-12 cycloalkyl group (for example, a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, etc.). , It is not limited to such an example. _{Among these cycloalkyl groups, a C 3-7} cycloalkyl group is preferable, and a cyclohexyl group is more preferable, from the viewpoint of obtaining an acrylic resin having excellent heat resistance and a small birefringence.

^{In R 3} of the formula (1), the aromatic group includes, for example, a C _6-20 aromatic group [for example, a C _6-20 aryl group (for example, a phenyl group, an o-tolyl group, an m-tolyl group, p. -Tollyl group, 2,3-xylyl group, 2,4-xylyl group, 2,5-xylsilyl group, 2,6-xsilyl group, 3,4-xsilyl group, 3,5-xsilyl group, 1-naphthyl group , 2-naphthyl group, binaphthyl group, anthryl group, etc.), C _7-20 aralkyl group (for example, benzyl group, etc.)], but the present invention is not limited to these examples. Among these aromatic groups, a phenyl group and a tolyl group are preferable from the viewpoint of obtaining a film having excellent heat resistance and a small birefringence.

In the structure represented by the formula (1), from the viewpoint of excellent heat resistance and the like, R ¹ and R ² are preferably independent hydrogen atoms or methyl groups, and R ³ is a C _1-10 alkyl group. It is a C _3-12 cycloalkyl group or a C _6-20 aromatic group, more preferably R ¹ and R ² are independent hydrogen atoms or methyl groups, and R ³ is a C _1-4 alkyl group, C. _{A 3-7} cycloalkyl group, a C _6-20 aryl group or a C _7-20 aralkyl group, more preferably R ¹ and R ² are independent hydrogen atoms or methyl groups, and R ³ is a methyl group. It is a cyclohexyl group, a phenyl group or a tolyl group, and most preferably R ¹ and R ² are independently hydrogen atoms or methyl groups, and R ³ is a cyclohexyl group or phenyl group.

The maleic anhydride structure and the maleimide structure are, for example, structures represented by the following formula (2).

（式中、Ｒ^４、Ｒ^５は互いに独立して水素原子またはメチル基であり、Ｒ^６は水素原子又は置換基であり、Ｘ^２は酸素原子または窒素原子である。Ｘ^２が酸素原子のときｎ＝０であり、Ｘ^２が窒素原子のときｎ＝１である。）

(In the formula, R ⁴ and R ⁵ are independent hydrogen atoms or methyl groups, R ⁶ is a hydrogen atom or a substituent, X ² is an oxygen atom or a nitrogen atom, and X ² is an oxygen atom. When n = 0, and when X ² is a nitrogen atom, n = 1.)

^{In R 6} of the formula (2), examples of the substituent include a hydrocarbon group and the like.
Examples of the hydrocarbon group include an aliphatic group {for example, an alkyl group [for example, a C _1-6 linear alkyl group (for example, a methyl group, an ethyl group, etc.), a C _1-6 branched alkyl group (for example, isopropyl). _{C 1-6} alkyl groups such as groups)], etc.}, alicyclic groups (eg, C _3-20 cycloalkyl groups such as cyclopentyl group, cyclohexyl group, etc.), aromatic groups {eg, C _6-20 An aromatic group [eg, C _7-20 aralkyl group (eg, benzyl group, etc.), C _6-20 aryl group (eg, phenyl group, etc.)]}. The hydrocarbon group may further have a substituent such as halogen.

When X ² is an oxygen atom, the ring structure represented by the formula (2) is a maleic anhydride structure. The maleic anhydride structure can be formed, for example, by copolymerizing maleic anhydride with a (meth) acrylic acid ester.

When X ² is a nitrogen atom, the ring structure represented by the formula (2) is a maleimide structure. The maleimide structure can be formed, for example, by copolymerizing maleimide with a (meth) acrylic acid ester.

When X ² is a nitrogen atom, from the viewpoint of excellent heat resistance, preferably, R ⁴ and R ⁵ are independently hydrogen atoms, and R ⁶ is a C _3-20 cycloalkyl group or C _6-20 aromatic. It is a group, more preferably R ⁴ and R ⁵ are independently hydrogen atoms, and R ⁶ is a cyclohexyl group or a phenyl group.

The lactone ring structure is not particularly limited, and may be, for example, a 4- to 8-membered ring, but a 5-membered ring or a 6-membered ring is preferable because of the excellent stability of the ring structure, and the 6-membered ring is used. More preferably.

The 6-membered lactone ring structure is, for example, a structure disclosed in Japanese Patent Application Laid-Open No. 2004-168882, but the high lactone due to the high polymerization yield of the precursor and the cyclization condensation reaction of the precursor. The structure represented by the following formula (3) is preferable because an acrylic resin having a ring content can be obtained.

（式中、Ｒ^７、Ｒ^８及びＲ^９は、互いに独立して、水素原子または置換基である。）

(In the formula, R ⁷ , R ⁸ and R ⁹ are independent hydrogen atoms or substituents.)

In the formula (3), examples of the substituent include organic residues such as a hydrocarbon group.
_{Examples of the hydrocarbon group include C 1-20} alkyl groups such as methyl group, ethyl group and propyl group, and _{C 2-20} unsaturated aliphatic hydrocarbon groups such as ethenyl group and propenyl group. Etc.), aromatic groups (for example, C _6-20 aromatic hydrocarbon groups such as phenyl group and naphthyl group) and the like. The hydrocarbon group may contain an oxygen atom, and one or more of the hydrogen atoms may be substituted with at least one group selected from a hydroxyl group, a carboxyl group, an ether group and an ester group.

In the formula (3), from the viewpoint of excellent heat resistance and the like, R ⁹ is preferably a hydrogen atom or a methyl group, and R ⁷ and R ⁸ are independently hydrogen atoms or C _1-20 alkyl groups, respectively. Preferably, R ⁹ is a hydrogen atom or a methyl group, and R ⁷ and R ⁸ are independent hydrogen atoms or a methyl group, respectively.

The lactam ring structure is not particularly limited, and is, for example, a pyrrolidinone ring structure represented by the following formula (4).
The pyrrolidinone ring structure has a 5-membered amide ring structure (cyclic amide structure) as a basic skeleton. This cyclic amide structure is also a 5-membered ring lactam structure (γ-lactam structure). Having a pyroridinone ring structure in the main chain means that at least one of the five atoms constituting the basic skeleton of the pyrrolidinone ring structure, which is a 5-membered ring, is typically an amide bond (-N (R) CO-). It means that three carbon atoms that do not form the main chain are located in the main chain of the polymer and form the main chain.

（式中、Ｒ^１０〜Ｒ^１２は、それぞれ独立して、水素原子または置換基である。）

(In the formula, R ^{10 to} R ¹² are independently hydrogen atoms or substituents.)

^{In R 10} of the formula (4), examples of the substituent include a hydrocarbon group or -NHCOR ¹³ group (R ¹³ is a hydrogen atom or a hydrocarbon group) and the like.

Examples of the hydrocarbon group in R ¹⁰ or R ¹³ include an aliphatic group, an alicyclic group, an aromatic group and the like.
Examples of the aliphatic group include _{C 1-18} linear or branched _{C 1-18} alkyl groups (eg, methyl group, ethyl group, propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group and the like. Alkyl group, etc.) and the like.
Examples of the alicyclic group include a C _3-18 cycloalkyl group (for example, a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, etc.).
Examples of the aromatic group include a C _6-20 aromatic group [for example, a C _6-20 aryl group (for example, a phenyl group, a tolyl group, a xsilyl group, a naphthyl group, an anthryl group, etc.), a C _7-20 aralkyl group, etc. (For example, benzyl group, etc.)].

As R ¹⁰ , a hydrogen atom, a C _1-18 linear alkyl group (for example, a methyl group, etc.) and the like are particularly preferable.
Further, as R ¹³ , in particular, a hydrogen atom, a C _1-18 linear alkyl group (preferably a C _1-12 linear alkyl group, more preferably a C _1-4 linear alkyl group, etc.), C _{6 -20} aryl groups (eg, phenyl groups, etc.), C _3-18 cycloalkyl groups (preferably C _3-12 cycloalkyl groups, more preferably C _3-6 cycloalkyl groups, etc.) and the like are preferred.

^{In R 11} of the formula (4), examples of the substituent include -COOR ¹⁴ groups (R ¹⁴ is a hydrogen atom or a hydrocarbon group) and the like.

Examples of the hydrocarbon group in R ¹⁴ include the hydrocarbon groups exemplified in ^{R 10} or R ^13.
Further, a particularly preferable aspect of ^{R 14} is the same as a particularly preferable aspect of ^{R 13.}

^{In R 12} of the formula (4), examples of the substituent include -COR ¹⁵ groups (R ¹⁵ is a hydrogen atom or a hydrocarbon group) and the like.

Examples of the hydrocarbon group in R ¹⁵ include the hydrocarbon groups exemplified in ^{R 10} or R ^13.
Also, a particularly preferred embodiment of ^{R 15} is the same as a particularly preferred embodiment of ^{R 13.}

The content of the ring structure in the acrylic resin is, for example, 1 to 60 mol%, preferably 1 to 40 mol%, and more preferably 2 to 30 mol%. The content of the ring structure in the acrylic resin is, for example, 1 to 80% by mass, preferably 1 to 50% by mass, and more preferably 2 to 40% by mass. In this case, the acrylic resin is preferable because it can achieve both excellent transparency, heat resistance and strength.

In particular, the content of the glutarimide structure and / or the glutaric anhydride structure in the acrylic resin is preferably 5% by mass or more, more preferably 10% by mass or more from the viewpoint of improving the heat resistance and transparency of the acrylic resin. More preferably, it is 15% by mass or more, and from the viewpoint of improving moldability to a film and increasing mechanical strength, for example, 90% by mass or less, preferably 60% by mass or less, more preferably 57% by mass or less. , More preferably 55% by mass or less.
The content of the glutarimide structure and / or the glutaric anhydride structure in the acrylic resin is, for example, 3 to 85 mol%, preferably 6 to 50 mol%, from the viewpoint of improving the heat resistance and transparency of the acrylic resin. , More preferably 10 to 40 mol%.

The content of the maleic anhydride structure and / or the (N-substituted) maleimide structure in the acrylic resin is, for example, 5 to 90% by mass, preferably 10 from the viewpoint of improving the heat resistance and transparency of the acrylic resin. It is ~ 70% by mass, more preferably 10 to 60% by mass, still more preferably 10 to 50% by mass.
The content of the maleic anhydride structure and / or the maleimide structure in the acrylic resin is, for example, 7 to 90 mol%, preferably 10 to 75 mol%, from the viewpoint of improving the heat resistance and transparency of the acrylic resin. More preferably, it is 10 to 60 mol%.

The content of the lactone structure in the acrylic resin is not particularly limited, but from the viewpoint of improving the heat resistance and transparency of the acrylic resin, for example, 10 to 70% by mass, preferably 15 to 50% by mass. It is preferably 15 to 45% by mass.
The content of the lactone structure in the acrylic resin is, for example, 6 to 60 mol%, preferably 9 to 37 mol%, more preferably 9 to 30 mol, from the viewpoint of improving the heat resistance and transparency of the acrylic resin. %.

The content of the lactam ring structure in the acrylic resin is not particularly limited, but from the viewpoint of improving the heat resistance and transparency of the acrylic resin, for example, 10 to 70% by mass, preferably 15 to 50% by mass. More preferably, it is 15 to 45% by mass.
The content of the lactam ring structure in the acrylic resin is, for example, 6 to 60 mol%, preferably 9 to 37 mol%, more preferably 9 to 30 from the viewpoint of improving the heat resistance and transparency of the acrylic resin. Mol%.

The weight average molecular weight (Mw) of the acrylic resin in terms of styrene by the GPC measurement method is not particularly limited, but is preferably 10,000 to 500,000, more preferably 30,000 to 300,000, and further preferably 50,000. ~ 200,000. When the weight average molecular weight is larger than 10,000, sufficient melt tension can be maintained in melt extrusion molding, a good sheet-shaped acrylic resin base material can be easily obtained, and dynamics such as breaking strength of the obtained base material can be obtained. Excellent physical properties. On the other hand, if it is smaller than 500,000, the molten resin does not become highly viscous, and foreign matter is generated on the surface of the base material obtained by melt extrusion molding due to fine wart-like irregularities or unmelted matter (high molecular weight body). Can be suppressed, and a good acrylic resin base material can be easily obtained.

When the acrylic resin has a glutarimide structure and / or a glutaric anhydride structure, the weight average molecular weight of the acrylic resin is preferably 10,000 or more, more preferably 30,000 or more, and is a film, from the viewpoint of increasing mechanical strength and the like. From the viewpoint of improving the moldability of the resin, the amount is preferably 500,000 or less, more preferably 300,000 or less.

The molecular weight distribution (Mw / Mn) of the acrylic resin by the GPC measurement method is preferably 1 to 10, more preferably 1.1 to 7.0, and even more preferably from the viewpoint of adjusting the viscosity to be suitable for molding. It is 1.2 to 5.0, most preferably 1.5 to 4.0.

The glass transition temperature (Tg) of the acrylic resin may be, for example, about 80 to 180 ° C., preferably about 90 to 170 ° C. Within these ranges, the heat resistance of the acrylic resin is sufficiently high and the moldability is good, which is preferable.

[Acrylic resin manufacturing method]
The method for producing an acrylic resin having a ring structure in the main chain is not particularly limited, and a conventionally known method for producing an acrylic resin may be followed.

Acrylic resins having a glutaric anhydride structure in the main chain include, for example, an acrylic resin containing a (meth) acrylic acid ester unit and a (meth) acrylic acid unit, and an adjacent (meth) acrylic acid ester unit and (meth) acrylic acid. It can be formed by an intramolecular dealcohol reaction between units.
The method for carrying out the intramolecular dealcohol reaction is not particularly limited, but can be carried out, for example, by heating.
The heating temperature is not particularly limited as long as it is a temperature at which an intramolecular cyclization reaction occurs due to dealcoholization, but may be, for example, 180 to 350 ° C.
The heating time can be appropriately changed depending on the composition of the acrylic resin and the like, but may be, for example, 1 to 2 hours.
Further, in the intramolecular dealcohol reaction, a catalyst (for example, an acid catalyst, a basic catalyst, a salt-based catalyst, etc.) may be used.

An acrylic resin having a glutarimide structure in the main chain can be formed, for example, by imidizing an acrylic resin containing a (meth) acrylic acid ester unit. The imidization method may follow a conventionally known method, and may be imidized using ammonia, a substituted amine, or the like.

An acrylic resin having a maleic anhydride structure and / or a maleimide structure in the main chain is, for example, a (meth) acrylic acid ester and a maleic anhydride and / or a maleimide-based compound {[for example, N-alkylmaleimide (for example, N-alkylmaleimide (for example)) as a polymerization component. _{, N-C 1-10} alkyl maleimide such as N-methylmaleimide, N-ethylmaleimide, etc.), N-cycloalkylmaleimide (eg, _{NC 3-20} cycloalkylmaleimide such as cyclohexylmaleimide), N-aryl _{Maleimide (eg, NC 6-10} arylmaleimide such as N-phenylmaleimide), N-aralkylmaleimide (eg, _{NC 7-10} aralkylmaleimide such as N-benzylmaleimide)], maleimide, etc.} It can be obtained by including and polymerizing (for example, radical polymerization, preferably solution polymerization).

An acrylic resin having a lactone ring structure in the main chain is, for example, an acrylic resin containing a 2- (hydroxymethyl) acrylic acid ester unit and a (meth) acrylic acid ester unit, and a hydroxyl group and an ester group as molecules between adjacent units. Internal dealcohol reaction (can be formed by doing).
The method for carrying out the intramolecular dealcohol reaction is not particularly limited, but can be carried out, for example, by heating an acrylic resin.
The heating temperature is not particularly limited as long as it is a temperature at which an intramolecular cyclization reaction occurs due to dealcoholization, and may be, for example, 60 to 350 ° C.
The heating time can be appropriately changed depending on the composition of the acrylic resin and the like, but may be, for example, 1 to 5 hours.
Further, in the intramolecular dealcohol reaction, a catalyst (for example, an organic phosphorus compound, a basic compound, an organic carboxylate, a carbonate, etc.) may be used.

Acrylic resins having a lactam ring structure in the main chain include, for example, (meth) acrylic acid ester and N-vinyllactam-based monomer [for example, N-vinylpyrrolidone-based monomer (for example, N-vinyl)] as polymerization components. Pyrrolidone, N-vinyl-4-butylpyrrolidone, N-vinyl-4-propylpyrrolidone, N-vinyl-4-ethylpyrrolidone, N-vinyl-4-methylpyrrolidone, N-vinyl-4-methyl-5-ethylpyrrolidone , N-Vinyl-4-methyl-5-propylpyrrolidone, N-vinyl-5-methyl-5-ethylpyrrolidone, N-vinyl-5-propylvirolidone, N-vinyl-5-butylpyrrolidone, etc.), N Polymerization containing-vinylcaprolactam-based monomers (eg, N-vinylcaprolactam, N-vinyl-6-methylcaprolactam, N-vinyl-6-propylcaprolactam, N-vinyl-7-butylcaprolactam, etc.)] For example, it can be obtained by radical polymerization, preferably solution polymerization).

The polymerization solvent used in the polymerization of the acrylic resin having a ring structure in the main chain and the acrylic resin as a precursor thereof is not particularly limited, but an organic solvent is preferable. The organic solvent is not particularly limited, but for example, an aromatic hydrocarbon solvent such as toluene, xylene and ethylbenzene; a ketone solvent such as methyl ethyl ketone and methyl isobutyl ketone; an ether solvent such as tetrahydrofuran; methanol, ethanol, butanol and the like. Examples include alcohol solvents. These solvents may be used alone or in combination of two or more.

Further, if the boiling point of the polymerization solvent is too high, the residual volatile content of the acrylic resin finally obtained increases. Therefore, the polymerization solvent is preferably a solvent having a boiling point of 40 to 200 ° C., and a boiling point of 40 to 100 ° C. Is more preferred.

The amount of the polymerization solvent used is not particularly limited, but may be appropriately selected from the range of 10 to 200 parts by mass with respect to 100 parts by mass of the total amount of the monomer composition in the polymerization system, preferably 15. It is ~ 150 parts by mass, more preferably 15 to 100 parts by mass.

The polymerization temperature can be appropriately selected depending on the reaction scale and the like, but usually, the internal temperature of the reaction solution may be in the range of 30 to 200 ° C., preferably 50 to 180 ° C., more preferably 70 to 160 ° C. ℃. In this case, the coloring of the acrylic resin can be suppressed, and a molded product having an excellent appearance can be obtained.

The polymerization time is not constant depending on the reaction scale, reaction temperature, etc., but is usually appropriately selected in the range of several minutes to 20 hours, preferably 0.5 to 20 hours, and more preferably 1 to 10 hours. .. In addition, several minutes means about 1 minute to 10 minutes.

In the polymerization of an acrylic resin having a ring structure in the main chain and an acrylic resin as a precursor thereof, a polymerization initiator may be used at the time of polymerization. The polymerization initiator is not particularly limited, and known compounds can be used.
Examples of the polymerization initiator include organic peroxides (for example, cumene hydroperoxide, etc.), azo compounds (for example, 2,2'-azobis (isobutyronitrile), etc.) and the like. The polymerization initiator may be used alone or in combination of two or more. The amount of the polymerization initiator used may be appropriately set according to the combination of monomers, reaction conditions, etc., and is not particularly limited.

In the polymerization of an acrylic resin having a ring structure in the main chain and an acrylic resin as a precursor thereof, a chain transfer agent may be used at the time of polymerization. The chain transfer agent is not particularly limited, and known compounds can be used.
Examples of the chain transfer agent include thiol compounds (for example, dodecyl mercaptan) and halogen compounds (for example, chloroform). The chain transfer agent may be used alone or in combination of two or more. The amount of the chain transfer agent used may be appropriately set according to the combination of monomers, reaction conditions, etc., and is not particularly limited.

The polymerization solution after completion of the polymerization may be subjected to the devolatile step described in JP-A-2000-20016, JP-A-2007-262396, JP-A-2007-262399 and the like.

Further, the polymerization solution after completion of the polymerization may be filtered. The filtration method is not particularly limited, and for example, filtration may be performed with a filter (for example, a filter of 0.01 to 15 μm).

[Base material composed of acrylic resin]
The shape of the base material (acrylic resin base material) made of an acrylic resin having a ring structure in the main chain is not particularly limited, and may be a two-dimensional shape (for example, a film), a three-dimensional shape, or the like. .. The shape of the acrylic resin base material is usually a film (or sheet) shape.

The method for producing the film is not particularly limited, and a conventionally known method may be followed.
For example, a film can be obtained by forming an acrylic resin by a known film forming method [for example, a solution casting method (solution casting method), a melt extrusion method, a calender method, a compression molding method, etc.]. As a film forming method, a solution casting method, a melt extrusion method and the like are preferable.

At the time of film formation, if desired, a solvent, other resin (for example, thermoplastic polymer, etc.) and other additives (for example, ultraviolet absorber, antioxidant, stabilizer, reinforcing material, flame retardant) , Antistatic agent, organic filler, inorganic filler, blocking inhibitor, resin modifier, organic filler, inorganic filler, plasticizer, lubricant, phase difference reducing agent, etc.) may be mixed with the acrylic resin. ..

Examples of the thermoplastic polymer include olefin polymers such as polyethylene, polypropylene, ethylene-propylene copolymer, and poly (4-methyl-1-pentene); halogens such as polyvinyl chloride, polyvinylidene chloride, and polyvinyl chloride. Vinyl polymer; styrene polymer such as polystyrene, styrene-methyl methacrylate copolymer, styrene-acrylonitrile copolymer, acrylonitrile-butadiene-styrene block copolymer; polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, etc. Polypolymers; cellulose acylates such as cellulose triacetate, cellulose acetate propionate, cellulose acetate butyrate; polyamides such as nylon 6, nylon 66, nylon 610; polyacetals; polycarbonates; polyphenylene oxides; polyphenylene sulfides; polyether ether ketones; polysulfones. Polyether sulfone; Polyoxybenzylene; Polyamideimide; A rubber polymer such as ABS resin or ASA resin containing polybutadiene rubber or acrylic rubber.

The amount of the other additives in the film is not particularly limited, but is preferably 0.01 to 10% by mass, more preferably 0.05 to 5% by mass in the film.
In particular, when the base material contains an acrylic resin and another resin (thermoplastic polymer) as the resin component, the entire resin component constituting the base material (the total amount of the acrylic resin and the other resin, or the base material The ratio of the acrylic resin to the total solid content) is, for example, 30% by mass or more (for example, 50% by mass or more), preferably 70% by mass or more, more preferably 80% by mass or more, and particularly 85% by mass or more. Good.

Devices for carrying out the solution casting method are, for example, a drum casting machine, a band casting machine, and a spin coater.

The solvent used in the solution casting method is not limited as long as the acrylic resin is dissolved.
The solvent is, for example, aromatic hydrocarbons such as benzene, toluene and xylene; aliphatic hydrocarbons such as cyclohexane and decalin; esters such as ethyl acetate and butyl acetate; ketones such as acetone, methyl ether ketone and methyl isobutyl ketone. Alcohols such as methanol, ethanol, isopropanol, butanol, isobutanol, methyl cellosolve, ethyl cellosolve, butyl cellosolve; ethers such as tetrahydrofuran and dioxane; halogenated hydrocarbons such as dichloromethane, chloroform and carbon tetrachloride; dimethylformamide; is there. As these solvents, one kind or two or more kinds can be used.

The melt extrusion method is, for example, a T-die method or an inflation method. The molding temperature during melt extrusion is preferably 150 to 350 ° C, more preferably 200 to 300 ° C.

When the T-die method is selected, for example, a strip-shaped film can be formed by attaching the T-die to the tip of a known extruder. The formed strip-shaped film may be wound on a roll to form a film roll. In the melt extrusion method, it is possible to continuously perform from the formation of an acrylic resin by mixing the materials to the molding of a film using the resin.

The film may be a biaxially stretched film from the viewpoint of increasing the mechanical strength. The biaxially stretched film may be either a simultaneous biaxially stretched film or a sequential biaxially stretched film. Further, the direction of the slow axis of the stretched film may be the flow direction of the film, the width direction, or any direction.

Further, the film may be surface-treated.
Examples of the surface treatment include corona discharge treatment and plasma treatment.
According to the composition for forming an easy-adhesion layer of the present invention, the adhesiveness between the film and the easy-adhesion layer is excellent even if the film is not surface-treated.

Further, a low moisture permeability layer may be provided in addition to the film and the easy-adhesion layer. The low moisture permeability layer is a layer capable of reducing the amount of water molecules passing through the film substrate. The low moisture permeability layer may be provided on the opposite side of the easy-adhesion layer, or may be provided between the film and the easy-adhesion layer. As the agent capable of forming the low moisture permeability layer, for example, it is preferably formed of a resin having a fluorinated alkyl group or a cyclic aliphatic hydrocarbon group (for example, acrylic resin, polyurethane resin, polyester resin, etc.). Further, it is also a preferable form to contain rosin, hydrogenated rosin, acid-modified rosin, esterified rosin and the like.

The thickness of the film is not particularly limited and can be appropriately adjusted depending on the intended use, but is, for example, 1 to 400 μm, preferably 5 to 200 μm, more preferably 10 to 100 μm, and further preferably 20 to 60 μm.
For example, when used in applications such as protective films, antireflection films, and polarizing films used in image display devices such as liquid crystal display devices and organic EL display devices, it is preferably 1 to 250 μm, more preferably 10 to 100 μm, and further. It is preferably 20 to 80 μm.
Within these ranges, an excellent film having sufficient strength and transparency can be obtained.

The haze of the film is preferably 1% or less (for example, 0 to 1%), more preferably 0.5% or less (for example, 0 to 0.5%). Haze is measured according to JIS K7136. By setting the haze to 1% or less, the color feeling displayed when the film is incorporated into the image display device becomes excellent.

The b value of the film is preferably 2% or less (for example, 0.1 to 2%), more preferably 1.5% or less (for example, 0.1 to 1.5%), and further preferably 1% or less (for example, 0.1% or less). For example, 0.1 to 1%), most preferably 0.5% or less (for example, 0.1 to 0.5%). By setting the b value to 2% or less, the color feeling displayed when the film is incorporated into the image display device becomes excellent.

The Tg of the film is, for example, 110 ° C. or higher (for example, 110 ° C. to 200 ° C.), preferably 115 ° C. to 170 ° C. A film having such a high Tg is suitable for optical applications because it can be easily arranged in the vicinity of a heat generating portion such as a light source in an image display device.

[Easy-adhesive substrate]
An easy-adhesive base material (adhesive base material, adhesive film) can be obtained by forming an easy-adhesive layer formed of the composition for forming an easy-adhesive layer on an acrylic resin base material.
The easy-adhesion layer may be formed on one side or both sides of the acrylic resin base material, but is usually formed on one side.
The easy-adhesion layer can be formed, for example, by applying a composition for forming an easy-adhesion layer to one side of an acrylic resin base material and drying it.

The method for applying the composition for forming an easy-adhesion layer is not particularly limited, and examples thereof include a bar coating method, a roll coating method, a gravure coating method, a rod coating method, a slot orifice coating method, a curtain coating method, and a fountain coating method. Be done.
The drying temperature is not particularly limited, but may be, for example, 50 ° C. or higher, preferably 90 to 200 ° C., and more preferably 110 to 180 ° C. Within these ranges, for example, a film having excellent color resistance (particularly, color resistance in a high temperature and high humidity environment) can be obtained.

In the adhesive substrate, the thickness of the easy-adhesive layer may be, for example, 100 nm to 10 μm, preferably 100 nm to 5 μm, and more preferably about 200 nm to 1.5 μm. In these ranges, the easy-adhesion layer has a good effect of improving the adhesiveness between the acrylic resin base material and the polarizer. In addition to this, it is possible to suppress the appearance of a phase difference in the easy-adhesion layer itself.

In the adhesive base material, the thickness ratio of the acrylic resin base material and the easy-adhesion layer is 1 / 0.1 / 1 / 0.001, preferably 1 / 0.05 to 1/0. It may be about 002, more preferably about 1 / 0.03 to 1 / 0.003. By setting the above range, the adhesiveness can be improved.

Further, the stretching treatment may be performed in the process of forming the adhesive base material or after the formation.
The stretching may be biaxial stretching. The biaxial stretching may be either simultaneous biaxial stretching or sequential biaxial stretching.
Further, from the viewpoints of improving the adhesiveness of the adhesive base material, preventing the decrease in phase difference, preventing the unevenness of the phase difference, and preventing the unevenness of the optical axis, the formation and stretching treatment of the easy-adhesive layer or the easy-adhesive layer (for example, lateral). Stretching) may be performed at the same time.

The coefficient of kinetic friction of the adhesive base material is preferably 0.1 to 0.6, more preferably 0.1 to 0.4. If it is smaller than 0.1, it becomes difficult to wind it into a roll. If it is larger than 0.6, it becomes difficult to maintain sufficient blocking resistance. The coefficient of dynamic friction may be measured according to JIS K 7125.

The moisture permeability of the adhesive substrate is preferably 200 g / m ³ days or less, more preferably 100 g / m ³ days or less, and further preferably 50 g / m ³ days or less. If it exceeds 200 g / m ³ days, the adhesiveness may decrease. The moisture permeability may be measured according to JIS Z 0208.

The use of the easily adhesive base material is not particularly limited, but it can be suitably used as an optical member.
The optical member is not particularly limited, but for example, an optical protective film [for example, a protective film for various optical disk (VD, CD, DVD, MD, LD, etc.) substrates, an image display device such as a liquid crystal display (LCD), etc. Polarizer protective film used for the polarizing plate provided in the above] and the like.

[Polarizer]
A polarizing plate (polarizing film) can be formed by adhering an easily adhesive base material to a polarizing element (polarizing film).
The polarizing plate can be obtained, for example, by adhering an easily adhesive base material to at least one surface of the polarizer via an easy adhesive layer.

The polarizing plate has at least a laminated unit in which a base material made of an acrylic resin having a ring structure in the main chain and a polarizer are laminated via an easy-adhesive layer formed of a composition for forming an easy-adhesive layer. You just have to do it.

The polarizer is not particularly limited, and examples thereof include a polyvinyl alcohol-based film. As the polyvinyl alcohol-based film, one dyed with iodine, one dyed with a dichroic dye, or the like can be used.

As the polyvinyl alcohol-based film, for example, a polyvinyl alcohol aqueous solution is formed and then uniaxially stretched for dyeing, or dyed and then uniaxially stretched, and then preferably subjected to durability treatment using a boron compound. Etc. may be used.
The film thickness of the polarizer may be preferably about 5 to 30 μm, more preferably about 10 to 20 μm.

Further, the easily adhesive base material and the polarizer (polarizing film) may be further adhered between the easily adhesive layer and the polarizer via an adhesive layer.
The adhesive material is not particularly limited, and a material that can be used as an adhesive material between the polarizer protective film and the polarizer can be used.
Examples of the adhesive include vinyl acetate adhesive, PVA adhesive, acrylic adhesive, polyester adhesive, polyamide adhesive, polyurethane adhesive, isocyanate adhesive, epoxy adhesive, and melamine adhesive. Examples thereof include synthetic rubber adhesives such as adhesives, chloroprene rubber adhesives, nitrile rubber adhesives, styrene rubber adhesives, and silicone rubber adhesives. These adhesives may be used alone or in combination of two or more.
Among these adhesives, polyurethane-based adhesives, isocyanate-based adhesives, and acrylic-based adhesives are preferable, and polyurethane-based adhesives are more preferable. The form of the adhesive is not particularly limited, and may be, for example, a solvent-based adhesive, an aqueous-based adhesive (water-dispersed type, water-soluble type), a solvent-free adhesive, or the like.

[Image display device]
The present invention also includes an image display device provided with the above-mentioned polarizing plate of the present invention. Examples of the image display device include a liquid crystal display device (LCD) and the like.
A liquid crystal display device usually includes a liquid crystal cell and a polarizing plate arranged on at least one side of the liquid crystal cell.
The method for manufacturing the image display device is not particularly limited, and a conventionally known method may be followed.

The present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the claims, and the embodiments obtained by appropriately combining the technical means disclosed in the different embodiments. Is also included in the technical scope of the present invention.

Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited by the following Examples as well as the present invention, and appropriate modifications are made to the extent that it can be adapted to the purpose of the above and the following. It is also possible to carry out, all of which are within the technical scope of the invention.
Further, as a sample for measuring the physical characteristics of the film, a sample was obtained from the central portion in the width direction.

<Weight average molecular weight>
The weight average molecular weight was determined by gel permeation chromatography (GPC) under the following conditions.
System: Tosoh GPC system HLC-8220
Developing solvent: Chloroform (manufactured by Wako Pure Chemical Industries, Ltd., special grade), flow rate: 0.6 ml / min Standard sample: TSK standard polystyrene (manufactured by Tosoh Corporation, PS-oligomer kit)
Measurement side column configuration: Guard column (Tosoh Co., Ltd., TSKguardcolum SuperHZ-L), Separation column (Tosoh Co., Ltd., TSKgel SuperHZM-M) 2 series connection Reference side column configuration: Reference column (Tosoh Co., Ltd., TSKgel SuperH-RC) )

<Glass transition temperature>
The glass transition temperature (Tg) was determined in accordance with JIS K7121 regulations. Specifically, it was obtained by using a differential scanning calorimeter (DSC-8230, manufactured by Rigaku Co., Ltd.) to raise the temperature of a sample of about 10 mg from room temperature to 200 ° C. at a heating rate of 20 ° C./min under a nitrogen gas atmosphere. It was calculated by the starting point method from the DSC curve. As a reference, α-alumina was used.

<Average film thickness>
The thickness of the film was measured at intervals of 20 mm in the width direction using a Digimatic micrometer (minimum display amount 0.001 mm) manufactured by Mitutoyo Co., Ltd., and the average value was calculated.

<Haze>
The haze of the film was measured using a turbidity meter (“NDH-5000” manufactured by Nippon Denshoku Kogyo Co., Ltd.) in accordance with JIS K7136.

<Average particle size and particle size distribution of fine particles>
The average particle size and particle size distribution of the fine particles were measured using a particle size distribution measuring device (“CPS Disc Century Model DC12000” manufactured by CPS Instruments. Inc.). Specifically, for the fine particles dispersed in water, the equivalent spherical distribution in the range of 100 nm or more as the primary particle size is measured by the above measuring device, and the obtained distribution is from the large particle side. The particle size of the particles having an integrated integrated body integration rate of 50% was determined, and this was taken as the average primary particle size (d50) of the fine particles. Separately from this, the particle size (d25) of the particles having an integrated volume fraction of 25% and the particle size (d75) of the particles having an integrated volume fraction of 75% in the distribution were obtained and their ratios (d25 / d75). Was used as the particle size distribution of the fine particles.

<Heat and water>
Two 50 x 50 mm film pieces were cut out from the obtained optical film, leaving 10 x 50 mm as a gripping margin, and the easy-adhesive layer surfaces were bonded to each other with an adhesive (Huntsman Japan, Araldai Trapid), and then 80. It was dried at ° C. for 24 hours. Further, 5 sheets were cut out and used as test samples in a size of 10 × 50 mm. Next, after immersing the five test samples in warm water at 60 ° C. for 2 hours, the grip margin was gripped and peeled off in the 90 ° C. direction at a speed of 1 mm / sec, and peeled off at the interface between the base film and the easy-adhesion layer. I confirmed the presence or absence of. The judgment was made according to the following criteria. Further, the peeling position of the easy-adhesion layer was confirmed by using an infrared spectrophotometer (Nexus 670 manufactured by Thermo-Nicolet) based on the presence or absence of absorption characteristic of the polyurethane resin.
◯: No sample peeled off at the interface between the base film and the easy-adhesion layer Δ: 1 to 3 out of 5 samples peeled off at the interface between the base film and the easy-adhesion layer ×: Easy adhesion to the base film 4 or more out of 5 samples peeled off at the interface with the layer

<Moisture and heat resistance>
Five test samples prepared in the same manner as the heat-resistant water-resistant test sample were placed in a constant temperature and humidity chamber at 85 ° C. and 85% RH, taken out after 200 hours, and then the grip margin was gripped at 90 ° C. at a speed of 1 mm / sec. It peeled off in the direction, and the presence or absence of peeling at the interface between the base film and the easy-adhesion layer was confirmed. The judgment was made according to the following criteria. Further, the peeling position of the easy-adhesion layer was confirmed by using an infrared spectrophotometer (Nexus 670 manufactured by Thermo-Nicolet) based on the presence or absence of absorption characteristic of the polyurethane resin.
◯: No sample peeled off at the interface between the base film and the easy-adhesion layer Δ: 1 to 3 out of 5 samples peeled off at the interface between the base film and the easy-adhesion layer ×: Easy adhesion to the base film 4 or more out of 5 samples peeled off at the interface with the layer

(Production Example 1-1 [Resin composition for forming a base material layer (A-1)])
In a reaction vessel equipped with a stirrer, temperature sensor, cooling tube and nitrogen introduction tube, 40 parts by weight of methyl methacrylate (MMA), 10 parts by weight of methyl 2- (hydroxymethyl) acrylate (MHMA), and 50 toluene as a polymerization solvent. 0.025 parts by weight and 0.025 parts by weight of an antioxidant (ADEKA STUB 2112, manufactured by ADEKA) were charged, and the temperature was raised to 105 ° C. through nitrogen.
When refluxing due to temperature rise started, 0.05 parts by weight of t-amylperoxyisononanoate (manufactured by Alchema Yoshitomi, trade name: Luperox 570) was added as a polymerization initiator, and the above t-amylperoxy was added. While 0.10 part by weight of isononanoate was added dropwise over 2 hours, solution polymerization was allowed to proceed under reflux at about 105 to 110 ° C., and aging was further carried out for 4 hours.
Next, 0.05 parts by weight of a stearyl phosphate / distearyl phosphate mixture (Phoslex A-18, manufactured by Sakai Chemical Industry Co., Ltd.) was added to the obtained polymerization solution as a catalyst (cyclization catalyst) for the cyclization condensation reaction. In addition, a cyclization condensation reaction for forming a lactone ring structure was allowed to proceed for 5 hours under reflux at about 90 to 110 ° C. Next, the obtained polymerization solution was passed through a heat exchanger to raise the temperature to 240 ° C., and the cyclization condensation reaction was further advanced at that temperature.
Next, the obtained polymerization solution was subjected to a barrel temperature of 240 ° C., a rotation speed of 100 rpm, a reduced pressure of 13.3 to 400 hPa (10 to 300 mmHg), one rear vent and four fore vents (first and first from the upstream side). A vent type in which a side feeder is provided between the second, third, and fourth vents), the third vent and the fourth vent, and a leaf disk type polymer filter (filtration accuracy 5 μm) is arranged at the tip. It was introduced into a screw twin-screw extruder (L / D = 52) at a processing speed of 90 parts by weight / hour (converted to the amount of resin) to carry out volatilization.
At that time, the mixed solution of the antioxidant / cyclization catalyst deactivating agent prepared separately was added at a rate of 1.06 parts by weight / hour after the first vent, and then 0.34 parts by weight of ion-exchanged water was added. It was charged after the second and third vents at a charging speed of / hour, respectively.
As a mixed solution of antioxidant / cyclization catalyst deactivating agent, 50 parts by weight of antioxidant (Irganox 1010 manufactured by BASF Japan Ltd.) and 35 parts by weight of zinc octylate (Nippon Kagaku), which is an inactivating agent, are used. A solution prepared by dissolving Nikkaoctix zinc (3.6%) manufactured by Sangyo Co., Ltd. in 200 parts by weight of toluene was used.
In addition to this, at the time of devolatilization, pellets of a styrene-acrylonitrile copolymer (AS resin: ratio of styrene unit / acrylonitrile unit is 73% by weight / 27% by weight, weight average molecular weight is 220,000) are taken from the side feeder. It was charged at a charging speed of 10 parts by weight / hour.
After the devolatilization is completed, the resin in the heat-melted state left in the extruder is discharged from the tip of the extruder while being filtered by a polymer filter, pelletized by a pelletizer, and has a lactone ring structure in the main chain (meth). A transparent pellet (A-1) of an acrylic resin containing an acrylic polymer as a main component (content content of 90% by weight) and a styrene-acrylonitrile copolymer at a content of 10% by weight was obtained. The weight average molecular weight of the resin composition constituting the resin pellet (A-1) was 132000, and the Tg was 125 ° C.

(Production Example 1-2 [Resin composition for forming a base material layer (A-2)])
In a reaction vessel equipped with a stirrer, temperature sensor, cooling tube and nitrogen gas introduction tube, 79.4 parts by weight of methyl methacrylate (MMA), 20.6 parts by weight of methacrylic acid (MAA), and 90.0 toluene as a polymerization solvent. A mixed solvent of 22.5 parts by weight of methanol and 0.05 parts by weight of an antioxidant (ADEKA STUB 2112, manufactured by ADEKA) were charged, and the temperature was raised to 73 ° C. while passing nitrogen gas into the reaction vessel. 0.25 weight of dimethyl-2,2'-azobis (2-methylpropionate) (manufactured by Wako Pure Chemical Industries, Ltd., trade name: V-601) as a polymerization initiator when refluxing due to temperature rise begins. Parts are added to the reaction vessel, and 0.35 parts by weight of the above dimethyl-2,2'-azobis (2-methylpropionate) is added to a mixed solvent of 7.3 parts by weight of toluene and 1.8 parts by weight of methanol. The solution of dimethyl-2,2'-azobis (2-methylpropionate) was subjected to solution polymerization under reflux at about 71-76 ° C. while dropping the solution in which the solution was dissolved into the reaction vessel over 2 hours. After completion of the dropping, aging was carried out for an additional 4 hours.
The content of the repeating unit derived from methacrylic acid in the (meth) acrylic resin contained in the polymer solution obtained above was 20.6% by weight. The weight average molecular weight of the (meth) acrylic resin was 110,000.
Next, a solution prepared by dissolving 0.05 parts by weight of sodium methoxydo, which is a catalyst for the cyclization condensation reaction (cyclization catalyst), in 5.0 parts by weight of methanol was added over 20 minutes at a temperature of about 65 to 70 ° C. It was added dropwise to the polymerization solution in the reaction vessel to prepare a uniform polymerization solution.
A vent type screw twin-screw extruder having a barrel temperature of 280 ° C., a rotation speed of 70 rpm, a decompression degree of 13.3 to 400 hPa (10 to 300 mmHg), a number of rear vents of 1, and a number of fore vents of 2 for the polymerization solution obtained above. Introduced into (pore diameter: 15 mm, L / D: 45) at a processing speed of 420 g / h in terms of resin amount, devolatile in this twin-screw extruder, and extruded with an in-screw residence time of about 3.2 minutes. As a result, transparent pellets (A-2) of a (meth) acrylic resin having a glutaric anhydride structure in the main chain were obtained. The weight average molecular weight of the resin composition constituting the resin pellet (A-2) was 97,000, and the glass transition temperature was 131 ° C. The anhydrous glutarous oxidation rate of the (meth) acrylic resin was 16.3%.

(Production Example 1-3 [Resin composition for forming a base material layer (A-3)])
In a reaction vessel equipped with a stirrer, a temperature sensor, a cooling tube, a nitrogen introduction tube, and a dropping funnel, 90 parts by mass of methyl methacrylate (MMA), 10 parts by mass of N-phenylmaleimide (PMI), and an antioxidant (Adecastab 2112). , Made by ADEKA) 0.05 parts by mass, 0.1 parts by mass of dodecyl mercaptan (DM) as a chain transfer agent, and 80.5 parts by mass of toluene were charged, and the contents were charged at 105 ° C. while introducing nitrogen gas. The temperature was raised to. When refluxing due to temperature rise started, 0.103 parts by mass of t-amylperoxyisononanoate (manufactured by Alchema Yoshitomi Co., Ltd., trade name: Luperox 570) was added as a polymerization initiator, and the above was added to 21 parts by mass of toluene. Solution polymerization was allowed to proceed while dropping a solution in which 0.205 parts by mass of t-amylperoxyisononanoate was dissolved over 2 hours, and aging was further carried out for 6 hours after the completion of the dropping.
Next, the obtained polymerization solution was subjected to a barrel temperature of 240 ° C., a rotation speed of 100 rpm, a decompression degree of 10.3 to 400 hPa (10 to 300 mmHg), one rear vent and four fore vents (first and first from the upstream side). It was introduced into a vent type screw twin-screw extruder (φ = 29.75 mm, L / D = 30) (referred to as 2, 3 and 4 vents) at a processing speed of 2.0 kg / hour in terms of resin amount. Devolatile was performed. At that time, the separately prepared antioxidant solution was added from behind the first vent at a charging rate of 0.03 kg / hour, and the ion-exchanged water was added from behind the third vent at a charging rate of 0.01 kg / hour. , Each was put in. As the antioxidant solution, a solution prepared by dissolving 50 parts by mass of an antioxidant (Sumilyzer GS, manufactured by Sumitomo Chemical Co., Ltd.) in 235 parts by mass of toluene was used.
After the devolatilization is completed, the resin composition in the hot-melted state left in the extruder is discharged from the tip of the extruder, pelletized by a pelletizer, and a transparent pellet of (meth) acrylic resin having a maleimide structure in the main chain. (A-3) was obtained. The weight average molecular weight of the resin composition constituting the resin pellet (A-3) was 129000, and the Tg was 129 ° C.

(Production Example 2 [Preparation of coating liquid (P-1) for forming an easy adhesive layer])
Urethane resin with carboxyl group (manufactured by Daiichi Kogyo Seiyaku Co., Ltd., Superflex 210, solid content 35% by weight) 11.2 parts by weight, glycerol polyglycidyl ether as a cross-linking agent (manufactured by Nagase ChemteX, Denacol EX-313, epoxy) Equivalent 141, viscosity 150 mPa · s, number of functional groups 2-3, number of atoms of longest atomic chain 7) 0.6 parts by weight, emulsion containing amorphous silica fine particles (manufactured by Nippon Catalyst Co., Ltd., Seahoster KE-W10, average particle size (primary) Particle size) 0.11 μm, particle size distribution 1.1, solid content 15.5% by weight) 1.3 parts by weight) and 26.9 parts by weight of pure water are mixed to form an emulsion-like easy-adhesion layer. A coating liquid for forming (P-1) was obtained.

(Production Example 3 [Preparation of coating liquid (P-2) for forming an easy adhesive layer])
Urethane resin (manufactured by Daiichi Kogyo Seiyaku Co., Ltd., Superflex 210, solid content 35% by weight) 11.2 parts by weight, glycerol polyglycidyl ether as a cross-linking agent (manufactured by Nagase ChemteX, Denacol EX-313, epoxy equivalent 141, viscosity 150 mPa · s, number of functional groups 2-3, number of atoms of longest atomic chain 7) 1.0 part by weight, emulsion containing amorphous silica fine particles (manufactured by Nippon Catalyst Co., Ltd., Seahoster KE-W10, average particle size (primary particle size) 0 .11 μm, particle size distribution 1.1, solid content 15.5% by weight) 1.3 parts by weight) and 26.6 parts by weight of pure water are mixed and coated to form an easy-adhesion layer, which is an emulsion-like dispersion. Liquid (P-2) was obtained.

(Production Example 4 [Preparation of coating liquid (P-3) for forming an easy adhesive layer])
Urethane resin (manufactured by Daiichi Kogyo Seiyaku Co., Ltd., Superflex 210, solid content 35% by weight) 11.2 parts by weight, glycerol polyglycidyl ether as a cross-linking agent (manufactured by Nagase ChemteX, Denacol EX-313, epoxy equivalent 141, viscosity 150 mPa · s, number of functional groups 2-3, number of atoms of longest atomic chain 7) 1.0 part by weight, emulsion containing amorphous silica fine particles (manufactured by Nippon Catalyst Co., Ltd., Seahoster KE-W30, average particle size (primary particle size) 0 .28 μm, particle size distribution 1.1, solid content 20% by weight) 0.1 parts by weight (manufactured by Nippon Catalyst Co., Ltd., Seahoster KE-W10, average particle size (primary particle size) 0.11 μm, particle size distribution 1.1, 0.8 parts by weight of solid content (15.5% by weight) and 27.0 parts by weight of pure water were mixed to obtain a coating liquid (P-3) for forming an easy-adhesion layer, which is an emulsion-like dispersion. ..

(Production Example 5 [Preparation of coating liquid (P-4) for forming an easy adhesive layer])
Urethane resin (manufactured by Daiichi Kogyo Seiyaku Co., Ltd., Superflex 210, solid content 35% by weight) 11.2 parts by weight, glycerol polyglycidyl ether as a cross-linking agent (manufactured by Nagase ChemteX, Denacol EX-313, epoxy equivalent 141, viscosity 150 mPa · s, number of functional groups 2-3, number of atoms of longest atomic chain 7) 1.0 part by weight, aqueous colloidal silica (manufactured by Nissan Chemical Co., Ltd., Snowtex C, average particle size (primary particle size) 10 to 15 nm, solid (20.5% by weight) (3.8 parts by weight) and 24.0 parts by weight of pure water were mixed to obtain a coating liquid (P-4) for forming an easy-adhesion layer, which is an emulsion-like dispersion.

(Production Example 6 [Preparation of coating liquid (P-5) for forming an easy adhesive layer])
Urethane resin (manufactured by Daiichi Kogyo Seiyaku Co., Ltd., Superflex 210, solid content 35% by weight) 11.2 parts by weight, oxazoline group-containing polymer as a cross-linking agent (manufactured by Nippon Catalyst Co., Ltd., Epocross WS-700, solid content 25% by weight) 3.9 parts by weight, emulsion containing amorphous silica fine particles (manufactured by Nippon Catalyst Co., Ltd., Seahoster KE-W10, average particle size (primary particle size) 0.11 μm, particle size distribution 1.1, solid content 15.5% by weight) 1 .3 parts by weight and 23.4 parts by weight of pure water were mixed to obtain a coating liquid (P-5) for forming an easy-adhesion layer, which is an emulsion-like dispersion.

(Production Example 7 [Preparation of coating liquid (P-6) for forming an easy adhesive layer])
Urethane resin (manufactured by Daiichi Kogyo Seiyaku Co., Ltd., Superflex 210, solid content 35% by weight) 11.2 parts by weight, carbodiimide group-containing polymer as a cross-linking agent (manufactured by Nisshinbo Chemical Co., Ltd., carbodilite V-02, solid content 40% by weight) 2.5 parts by weight, emulsion containing amorphous silica fine particles (manufactured by Nippon Catalyst Co., Ltd., Seahoster KE-W10, average particle size (primary particle size) 0.11 μm, particle size distribution 1.1, solid content 15.5% by weight) 1 .3 parts by weight and 24.9 parts by weight of pure water were mixed to obtain a coating liquid (P-6) for forming an easy-adhesion layer, which is an emulsion-like dispersion.

(Example 1)
The resin composition (A-1) for forming a substrate layer obtained in Production Example 1-1 was used at 282 ° C. using a single-screw extruder equipped with a polymer filter (filtration accuracy 5 μm) and a T-die at the tip. It is melt-extruded and discharged onto a cooling roll at 125 ° C. to form an unstretched film with a thickness of 192 μm, which is then continuously supplied to an oven longitudinal stretching machine to bring the oven temperature to 140 ° C. in the longitudinal direction. The film was stretched at a stretching ratio of 2.0 times to obtain a vertically stretched film having a thickness of 136 μm. Next, the thickness of the coating film after drying the coating liquid (P-1) for forming an easy-adhesive layer obtained in Production Example 2 on one surface of the obtained longitudinally stretched film becomes 1.3 μm. After applying with a bar coater (# 8), grasp the position 20 mm from both ends with a 2-inch clip and supply it to the tenter stretching machine, set the oven temperature to 143 ° C, form an easy-adhesive layer and stretch magnification 3 A 40 μm optical film having an easy-adhesion layer on one side was obtained by lateral stretching 3 times.

(Example 2)
An easy-adhesive layer was formed on one side in the same manner as in Example 1 except that the easy-adhesive layer-forming coating liquid (P-2) obtained in Production Example 3 was used as the coating liquid for forming the easy-adhesive layer. An optical film having a size of 40 μm was obtained.

(Example 3)
An easy-adhesive layer was formed on one side in the same manner as in Example 1 except that the easy-adhesive layer-forming coating liquid (P-3) obtained in Production Example 4 was used as the coating liquid for forming the easy-adhesive layer. An optical film having a size of 40 μm was obtained.

(Example 4)
An easy-adhesive layer was formed on one side in the same manner as in Example 1 except that the easy-adhesive layer-forming coating liquid (P-4) obtained in Production Example 5 was used as the coating liquid for forming the easy-adhesive layer. An optical film having a size of 40 μm was obtained.

(Example 5)
The resin composition (A-2) for forming a substrate layer obtained in Production Example 1-2 was used at 290 ° C. using a single-screw extruder equipped with a polymer filter (filtration accuracy 5 μm) and a T-die at the tip. It is melt-extruded and discharged onto a cooling roll at 131 ° C. to form an unstretched film with a thickness of 192 μm, which is then continuously supplied to an oven longitudinal stretching machine to bring the oven temperature to 146 ° C. in the longitudinal direction. The film was stretched at a stretching ratio of 2.0 times to obtain a vertically stretched film having a thickness of 136 μm. Next, the thickness of the coating film after drying the coating liquid (P-1) for forming an easy-adhesive layer obtained in Production Example 2 on one surface of the obtained longitudinally stretched film becomes 1.3 μm. After applying with a bar coater (# 8), grasp the position 20 mm from both ends with a 2-inch clip and supply it to the tenter stretching machine, set the oven temperature to 149 ° C, form an easy-adhesive layer and stretch magnification 3 A 40 μm optical film having an easy-adhesion layer on one side was obtained by lateral stretching 3 times.

(Example 6)
The resin composition (A-3) for forming a base material layer obtained in Production Example 1-3 was used at 290 ° C. using a single-screw extruder equipped with a polymer filter (filtration accuracy 5 μm) and a T-die at the tip. After melt extrusion and discharging on a cooling roll at 129 ° C to form an unstretched film with a thickness of 192 μm, it is continuously supplied to an oven longitudinal stretching machine as it is, and the oven temperature is adjusted to 144 ° C. in the longitudinal direction. The film was stretched at a stretching ratio of 2.0 times to obtain a vertically stretched film having a thickness of 136 μm. Next, the thickness of the coating film after drying the coating liquid (P-1) for forming an easy-adhesive layer obtained in Production Example 2 on one surface of the obtained longitudinally stretched film becomes 1.3 μm. After applying with a bar coater (# 8), grasp the position 20 mm from both ends with a 2-inch clip and supply it to the tenter stretching machine, set the oven temperature to 147 ° C, form an easy-adhesive layer and stretch magnification 3 A 40 μm optical film having an easy-adhesion layer on one side was obtained by lateral stretching 3 times.

(Example 7)
A (meth) acrylic resin (manufactured by Asahi Kasei Co., Ltd., Delpet 980N, Tg 120 ° C.) having a maleic anhydride structure in the main chain is used as the resin composition (A-4) for forming the base material layer, and a polymer filter (filtering accuracy) is applied to the tip. Melt-extruded at 275 ° C. using a single-screw extruder equipped with 5 μm) and a T-die, discharged onto a cooling roll at 120 ° C. to form an unstretched film with a thickness of 192 μm, and then continuously ovened as it is. The film was supplied to a longitudinal stretching machine, the temperature of the oven was set to 135 ° C., and stretching was performed in the longitudinal direction at a stretching ratio of 2.0 times to obtain a longitudinally stretched film having a thickness of 136 μm. Next, the thickness of the coating film after drying the coating liquid (P-1) for forming an easy-adhesive layer obtained in Production Example 2 on one surface of the obtained longitudinally stretched film becomes 1.3 μm. After applying with a bar coater (# 8), grasp the position 20 mm from both ends with a 2-inch clip and supply it to the tenter stretching machine, set the oven temperature to 138 ° C, form an easy-adhesive layer and stretch magnification 3 A 40 μm optical film having an easy-adhesion layer on one side was obtained by lateral stretching 3 times.

(Example 8)
A (meth) acrylic resin (manufactured by Daicel Ebonic, PLEXIMID 8813, weight average molecular weight 87,000, Tg 131 ° C.) having a glutarimide structure in the main chain as a resin composition (A-5) for forming a base material layer is applied to the tip portion. After melt-extruding at 290 ° C. using a single-screw extruder equipped with a polymer filter (filtration accuracy 5 μm) and a T-die, and discharging it on a cooling roll at 120 ° C., an unstretched film having a thickness of 192 μm is formed. As it was, it was continuously supplied to an oven longitudinal stretching machine, the temperature of the oven was set to 146 ° C., and stretching was performed in the longitudinal direction at a stretching ratio of 2.0 times to obtain a longitudinally stretched film having a thickness of 136 μm. Next, the thickness of the coating film after drying the coating liquid (P-1) for forming an easy-adhesive layer obtained in Production Example 2 on one surface of the obtained longitudinally stretched film becomes 1.3 μm. After applying with a bar coater (# 8), grasp the position 20 mm from both ends with a 2-inch clip and supply it to the tenter stretching machine, set the oven temperature to 149 ° C, form an easy-adhesive layer and stretch magnification 3 A 40 μm optical film having an easy-adhesion layer on one side was obtained by lateral stretching 3 times.

(Comparative Example 1)
Similar to Example 1, the easy-adhesive layer is provided on one side, except that the easy-adhesive layer-forming coating liquid (P-5) obtained in Production Example 6 is used as the coating liquid for forming the easy-adhesive layer. An optical film of 40 μm was obtained.

(Comparative Example 2)
An easy-adhesive layer was formed on one side in the same manner as in Example 1 except that the easy-adhesive layer-forming coating liquid (P-6) obtained in Production Example 7 was used as the coating liquid for forming the easy-adhesive layer. An optical film having a size of 40 μm was obtained.

The evaluation results of the optical films produced in each Example and Comparative Example are summarized in Table 1 below.

As shown in Examples 1 to 8, the composition for forming an easy-adhesion layer contains a polyurethane resin (A) having a carboxyl group and an epoxy compound (B) to adhere even under high temperature and high humidity. It was confirmed that an easily adhesive base material having excellent properties can be obtained.
On the other hand, in Comparative Example 1 in which the composition for forming an easy-adhesion layer contains an oxazoline group-containing polymer instead of an epoxy compound, and Comparative Example 2 in which the composition for forming an easy-adhesion layer contains a carbodiimide group-containing polymer, the easy-adhesive substrate is adhered under high temperature and high humidity. It was confirmed that the sex became worse.
From the above, according to the composition for forming an easy-adhesive layer of the present invention, an easy-adhesive layer having excellent adhesiveness to the acrylic resin base material can be formed on the acrylic resin base material, and this easy-adhesion can be formed. Since the layer has excellent adhesiveness even under high temperature and high humidity, it can be adhered to other functional films (for example, a polarizer) with high adhesiveness under high temperature and high humidity.

According to the present invention, an easy-adhesive layer having excellent adhesion to the acrylic resin base material can be formed on the acrylic resin base material even under high temperature and high humidity. By laminating through the adhesive layer, it is possible to obtain a polarizing plate having excellent adhesion between the acrylic resin base material and the polarizer even under high temperature and high humidity, and further, an image display device provided with this polarizing plate.

Claims (17)

A composition for forming an easy-adhesive layer on a substrate which is composed of an acrylic resin having a ring structure in the main chain and does not contain a crosslinked elastic body, and is a polyurethane resin (A) having a carboxyl group and an epoxy compound. A composition for forming an easy-adhesion layer containing (B). A composition for forming an easy-adhesive layer on a base material which is a biaxially stretched film and is composed of an acrylic resin having a ring structure in the main chain. A polyurethane resin (A) having a carboxyl group and an epoxy compound. A composition for forming an easy-adhesive layer containing (B) and fine silica fine particles . The composition according to claim 1 or 2 , wherein the ring structure has at least one structure selected from a maleic anhydride structure, a maleimide structure, a glutaric anhydride structure, a glutarimide structure, a lactam ring structure, and a lactone ring structure. Polyurethane resin (A) has a tensile elastic modulus of 1000 N / mm ² More than 5000 N / mm ² The composition according to any one of claims 1 to 3, which does not satisfy the following. The composition according to any one of claims 1 to 4, wherein the epoxy compound (B) contains an aliphatic epoxy compound. The composition according to any one of claims 1 to 5 , wherein the epoxy compound (B) satisfies an epoxy equivalent of 200 g / equivalent or less and a viscosity of 2000 mPa · s or less. The composition according to any one of claims 1 to 6 , wherein the epoxy compound (B) contains an aliphatic polyol polyglycidyl ether and satisfies an epoxy equivalent of 170 g / equivalent or less. The composition according to any one of claims 1 to 7 , wherein the ratio of the polyurethane resin (A) to the epoxy compound (B) is the former / the latter (weight ratio) = 99/1 to 10/90.
An easy-adhesion layer composed of an acrylic resin having a ring structure in the main chain and not containing a crosslinked elastic body, and the composition according to any one of claims 1, 3 to 8 on the base material. Easy-adhesive substrate including and. A base material formed of an acrylic resin having a ring structure in the main chain and being a biaxially stretched film, and an easily adhesive layer formed on the base material with the composition according to any one of claims 2 to 8. Easy-adhesive substrate including. The adhesive base material according to claim 9, wherein the base material is a biaxially stretched film. The adhesive base material according to any one of claims 9 to 11, wherein the thickness ratio of the base material to the easy-adhesion layer is 1 / 0.1 / 1 / 0.001 for the former / the latter. The adhesive substrate according to any one of claims 9 to 12, which is for optics. The adhesive base material according to any one of claims 9 to 13 , for adhering to a polarizer. A base material and a polarizing element which are composed of an acrylic resin having a ring structure in the main chain and do not contain a crosslinked elastic body via an easy-adhesion layer formed of the composition according to any one of claims 1 , 3 to 8. A polarizing plate having a laminated unit in which and is laminated. A base material and a polarizing element, which are made of an acrylic resin having a ring structure in the main chain and are a biaxially stretched film, are formed via an easy-adhesion layer formed of the composition according to any one of claims 2 to 8. A polarizing plate having a laminated stacking unit. An image display device comprising the polarizing plate according to claim 15 or 16.