KR20170042231A - Adhesive composition, adhesive layer and optical member with adhesive layer - Google Patents

Abstract

The present invention provides an adhesive composition having good durability when adhered to the surface of an optical member as an adhesive layer, an adhesive layer comprising the same, and an optical member having an adhesive layer attached thereto and comprising the adhesive layer, wherein the adhesive composition comprises: 0.2-4 wt% of a constituent unit derived from a (meth)acrylic monomer having a hydroxyl group; 0-4 wt% of a constituent unit derived from a (meth)acrylic monomer having a carboxylic group; 100 parts by weight of a (meth)acrylic resin (A) having a glass transition temperature of -55C or more; 0.1-1 parts by weight of an isocyanate-based crosslinker (B) in which an isocyanate group is bonded to a carbon atom constituting an aliphatic skeleton.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a pressure-sensitive adhesive composition, a pressure-sensitive adhesive layer, and an optical member with a pressure-

The present invention relates to a pressure-sensitive adhesive composition, a pressure-sensitive adhesive layer containing the pressure-sensitive adhesive composition, and an optical member comprising the pressure-sensitive adhesive layer.

A polarizing plate in which a protective film is laminated and laminated on one surface or both surfaces of a polarizer is useful as an image display device such as a liquid crystal display device or an organic electroluminescent (organic EL) display device, and more particularly to a mobile phone, a smart phone, And is widely used in various mobile devices. An optical member such as a polarizing plate is often used by being bonded to another member (for example, an optical member such as a liquid crystal cell in a liquid crystal display device) through a pressure-sensitive adhesive layer (for example, Japanese Patent Application Laid-Open No. 2010-229321 (Patent Document 1) Reference〕. For this reason, for example, in most cases, the polarizing plate is distributed on the market in the form of a polarizing plate with a pressure-sensitive adhesive layer provided with a pressure-sensitive adhesive layer on one surface thereof in advance.

[Patent Document 1] Japanese Patent Application Laid-Open No. 2010-229321

The pressure-sensitive adhesive composition used in the pressure-sensitive adhesive layer for optical member bonding is required to have durability. That is, the pressure-sensitive adhesive layer bonded to the optical member and inserted into an image display device or the like may be placed under a high temperature or high temperature and high humidity environment or under an environment where high temperature and low temperature are repeated. In this pressure environment, It is required to be able to suppress problems that may occur in accordance with the dimensional change of the optical member. Such problems include lifting and peeling at the interface between the pressure-sensitive adhesive layer and the optical member adjacent thereto, and foaming of the pressure-sensitive adhesive layer.

However, the conventional pressure-sensitive adhesive composition has insufficient durability when bonded to an optical member as a pressure-sensitive adhesive layer, and the surface of the optical member to which the pressure-sensitive adhesive layer is bonded is hardly activated effectively by surface activation treatment such as corona treatment In the case of the surface, in particular, the durability was sometimes insufficient.

The present invention relates to a pressure-sensitive adhesive composition having excellent durability when bonded as a pressure-sensitive adhesive layer on the surface, a pressure-sensitive adhesive layer containing the pressure-sensitive adhesive layer, and a pressure-sensitive adhesive layer thereof, even if the surface of the optical member is not easily activated by surface activation treatment It is an object of the present invention to provide an optical member with a pressure-sensitive adhesive layer.

The present invention provides the following pressure-sensitive adhesive composition, pressure-sensitive adhesive layer and optical member with a pressure-sensitive adhesive layer.

[1] A photosensitive resin composition, which comprises [1] a photosensitive resin composition comprising 0.2 to 4% by weight of a structural unit derived from a (meth) acrylic monomer having a hydroxyl group and 0 to 4% by weight of a structural unit derived from a (meth) acrylic monomer having a carboxyl group, 100 parts by weight of a (meth) acrylic resin (A) having a temperature of -55 캜 or higher,

0.1 to 1 part by weight of an isocyanate-based crosslinking agent (B) having an isocyanate group bonded to carbon atoms constituting an aliphatic skeleton

By weight.

[2] The pressure-sensitive adhesive composition according to [1], wherein the isocyanate group is bonded to a carbon atom constituting the methylene group.

[3] The pressure-sensitive adhesive composition according to [1] or [2], wherein the content of the structural unit derived from the (meth) acrylic monomer having a hydroxyl group is 3.5% by weight or less.

[4] The pressure-sensitive adhesive composition according to any one of [1] to [3], further comprising an ionic compound (C).

[5] The pressure-sensitive adhesive composition according to any one of [1] to [4], further comprising a silane compound (D).

[6] A pressure-sensitive adhesive layer comprising the pressure-sensitive adhesive composition according to any one of [1] to [5].

[7] An optical member with a pressure-sensitive adhesive layer, comprising an optical member and a pressure-sensitive adhesive layer according to [6] laminated thereon.

[8] The optical member with a pressure-sensitive adhesive layer according to [7], wherein the surface of the optical member on which the pressure-sensitive adhesive layer is laminated has a contact angle change rate of 40% or less when corona treatment is performed.

[9] The optical member includes a polarizer and a protective film laminated thereon,

The optical member with a pressure-sensitive adhesive layer according to [8], wherein the surface is a surface of the protective film.

[10] The optical member with a pressure-sensitive adhesive layer according to [8] or [9], wherein the surface is a corona-treated surface.

According to the present invention, it is possible to provide a pressure-sensitive adhesive composition having excellent durability, a pressure-sensitive adhesive layer containing the same, and an optical member with a pressure-sensitive adhesive layer having the pressure-sensitive adhesive layer.

1 is a schematic sectional view showing an example of an optical member with a pressure-sensitive adhesive layer according to the present invention.
2 is a schematic cross-sectional view showing another example of the optical member with a pressure-sensitive adhesive layer according to the present invention.
3 is a schematic sectional view showing still another example of the optical member with a pressure-sensitive adhesive layer according to the present invention.
4 is a schematic sectional view showing still another example of the optical member with a pressure-sensitive adhesive layer according to the present invention.

≪ Pressure sensitive adhesive composition &

[1] (meth) acrylic resin (A)

The (meth) acrylic resin (A) is a polymer containing a structural unit derived from a (meth) acrylic monomer having a hydroxyl group, and preferably has a structural unit represented by the following formula (I):

(Meth) acrylate as a main component. In the present specification, "(meth) acryl" means acryl and / or methacryl, and "(meth)" when it is called (meth) acrylate is also intended.

In the formula (I), R ¹ represents a hydrogen atom or a methyl group, R ² represents an alkyl group having 1 to 14 carbon atoms or an alkoxy group having 1 to 10 carbon atoms which may be substituted with an alkoxy group having 1 to 10 carbon atoms And an aralkyl group having 7 to 21 carbon atoms. R ² is preferably an alkyl group having 1 to 14 carbon atoms which may be substituted with an alkoxy group having 1 to 10 carbon atoms.

Specific examples of the (meth) acrylic esters represented by the formula (I) include methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, n-butyl (meth) Straight-chain (meth) acrylic acid alkyl esters such as octyl and (meth) acrylic acid lauryl; (Meth) acrylic acid alkyl esters such as isobutyl (meth) acrylate, 2-ethylhexyl (meth) acrylate and isooctyl (meth) acrylate.

Specific examples of the (meth) acrylic acid ester represented by the formula (I) in the case where R ² is an alkyl group substituted with an alkoxy group, that is, when R ² is an alkoxyalkyl group, include 2-methoxyethyl (meth) (Meth) acrylate, and the like. Specific examples of the (meth) acrylic acid ester represented by the formula (I) in the case where R ² is an aralkyl group having 7 to 21 carbon atoms include benzyl (meth) acrylate and the like.

The (meth) acrylic esters represented by the formula (I) may be used alone, or two or more kinds thereof may be used in combination. Among them, the (meth) acrylic acid ester preferably includes n-butyl acrylate. The (meth) acrylic resin (A) preferably contains at least 50% by weight of constituent units derived from n-butyl acrylate among the entire constituent units constituting the (meth) acrylic resin (A). Of course, other (meth) acrylic esters represented by the formula (I) may be used in addition to n-butyl acrylate.

The content of the constituent unit derived from the (meth) acrylic acid ester represented by the formula (I) is usually 60% by weight or more and less than 100% by weight among all the constituent units constituting the (meth) acrylic resin (A) 70 to 99.9% by weight, and more preferably 80 to 99.6% by weight.

The (meth) acrylic resin (A) contains a structural unit derived from a (meth) acrylic monomer having a hydroxyl group. The incorporation of this constituent unit is advantageous in enhancing the adhesion between the pressure-sensitive adhesive layer and the optical member and the durability of the pressure-sensitive adhesive layer. A suitable example of the (meth) acrylic monomer having a hydroxyl group is a (meth) acrylic acid ester having a hydroxyl group. Specific examples of the (meth) acrylic acid ester having a hydroxyl group include 2-hydroxyethyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 4-hydroxybutyl 2-hydroxyethoxy) ethyl, (meth) acrylic acid 2- or 3-chloro-2-hydroxypropyl, diethylene glycol mono (meth) acrylate and the like.

The content of the structural unit derived from a (meth) acrylic monomer having a hydroxyl group is preferably 4% by weight or less, and more preferably 3.5% by weight or less, based on all structural units constituting the (meth) acrylic resin (A) Is not more than 3% by weight. When the content of the constituent unit derived from the (meth) acrylic monomer having a hydroxyl group exceeds 4% by weight, the pressure-sensitive adhesive layer has insufficient durability, particularly heat resistance. On the other hand, the content of the structural unit derived from a (meth) acrylic monomer having a hydroxyl group is usually 0.2% by weight or more, preferably 0.5% by weight or more, and more preferably 1.0% by weight or more. If the content of the structural unit derived from a (meth) acrylic monomer having a hydroxyl group is less than 0.2% by weight, the adhesion between the pressure-sensitive adhesive layer and the optical member and the durability of the pressure-sensitive adhesive layer are insufficient.

The (meth) acrylic resin (A) may contain a structural unit derived from a monomer having a polar functional group other than the (meth) acrylic monomer having a hydroxyl group. The monomer having a polar functional group is preferably a (meth) acrylic monomer having a polar functional group. Examples of the polar functional group possessed by the monomer include a carboxyl group (free carboxyl group), an amino group, and a heterocyclic group (e.g., an epoxy group).

Specific examples of the monomer having another polar functional group include monomers having a carboxyl group such as (meth) acrylic acid, methacrylic acid, and? -Carboxyethyl (meth) acrylate; Acrylonitrile, acryloylmorpholine, vinylcaprolactam, N-vinyl-2-pyrrolidone, vinylpyridine, tetrahydrofurfuryl (meth) acrylate, caprolactone-modified tetrahydrofurfuryl acrylate, 3,4-epoxycyclohexyl Monomers having a heterocyclic group such as methyl (meth) acrylate, glycidyl (meth) acrylate, and 2,5-dihydrofuran; Monomers having an amino group different from a heterocyclic ring such as aminoethyl (meth) acrylate, N, N-dimethylaminoethyl (meth) acrylate, dimethylaminopropyl (meth) acrylate and the like. The monomers having other polar functional groups may be used alone, or two or more monomers may be used in combination.

The use of a monomer having another polar functional group, particularly a (meth) acrylic monomer having a carboxyl group, in addition to the (meth) acrylic monomer having a hydroxyl group is preferable because the adhesion between the pressure-sensitive adhesive layer and the optical member and the durability ). ≪ / RTI >

The content of the constituent unit derived from a (meth) acrylic monomer having a different polar functional group, preferably a carboxyl group, in the total constituent units constituting the (meth) acrylic resin (A) is 0% by weight or more, Is not more than 4% by weight. As described above, it is preferable that the (meth) acrylic resin (A) contains a constituent unit derived from a (meth) acrylic monomer having a carboxyl group and the content of the constituent unit Preferably 0.02% by weight or more, more preferably 0.05% by weight or more, and even more preferably 0.1% by weight or more. If the content of the constituent unit derived from a monomer having another polar functional group is less than 0.02% by weight, the effect of use is hardly recognized. On the other hand, the content of the constituent unit derived from the (meth) acrylic monomer having a different polar functional group, preferably the carboxyl group, is preferably 4% by weight or less, Or less, and more preferably 3.5 wt% or less. If the content of the constituent unit derived from a monomer having another polar functional group exceeds 4% by weight, the durability of the pressure-sensitive adhesive layer, particularly the heat resistance tends to be insufficient. The structural unit derived from a monomer having all of the polar functional groups including a (meth) acrylic monomer having a hydroxyl group is usually 1 to 10% by weight, preferably 1 to 10% by weight, of all structural units constituting the (meth) acrylic resin 1.1 to 8% by weight.

(Meth) acrylic resin (A) is preferably a monomer having one olefinic double bond and at least one aromatic ring in the molecule (except for the monomer (I) or the monomer having the polar functional group) And may further contain a derived structural unit. Suitable examples include (meth) acrylic monomers having an aromatic ring. The (meth) acrylic monomers having such an aromatic ring include neopentyl glycol benzoate (meth) acrylate and the like. In particular, the following formula (II):

(Meth) acrylic acid ester having an aryloxyalkyl group such as a phenoxyethyl group-containing (meth) acrylic acid ester represented by the following formula

In the formula (II), R ³ represents a hydrogen atom or a methyl group, n represents an integer of 1 to 8, and R ⁴ represents a hydrogen atom, an alkyl group, an aralkyl group or an aryl group. When R ⁴ is an alkyl group, the number of carbon atoms thereof may be about 1 to 9. When the aralkyl group is an aralkyl group, the number of carbon atoms thereof is about 7 to 11, and when it is an aryl group, the number of carbon atoms thereof may be about 6 to 10.

Examples of the alkyl group having 1 to 9 carbon atoms for R ⁴ in formula (II) include methyl, butyl, nonyl and the like. Examples of the aralkyl group having 7 to 11 carbon atoms include benzyl, phenethyl and naphthylmethyl groups. Examples of the aryl group include phenyl, tolyl and naphthyl.

Specific examples of the phenoxyethyl group-containing (meth) acrylic acid ester represented by the formula (II) include 2-phenoxyethyl (meth) acrylate, 2- (2-phenoxyethoxy) ethyl (Meth) acrylic acid ester of nonylphenol, 2- (o-phenylphenoxy) ethyl (meth) acrylate and the like. The phenoxyethyl group-containing (meth) acrylate ester may be used alone, or two or more kinds thereof may be used in combination. Among them, the phenoxyethyl group-containing (meth) acrylic acid ester is preferably selected from the group consisting of 2-phenoxyethyl (meth) acrylate, 2- (o-phenylphenoxy) ethyl (meth) Phenoxyethoxy) ethyl.

The content of the constituent unit derived from a monomer having an aromatic ring is usually 0 to 20% by weight (for example, 6 to 12% by weight) among all the constituent units constituting the (meth) acrylic resin (A). However, in order to bring the glass transition temperature of the (meth) acrylic resin (A) into a predetermined range to be described later, it is preferable not to include a monomer-derived structural unit having an aromatic ring.

(Meth) acrylic resin (A) is derived from a monomer other than the (meth) acrylic acid ester of the formula (I), the monomer having a polar functional group and the monomer having an aromatic ring (hereinafter also referred to as "other monomers") May be included. Examples of other monomers include structural units derived from a (meth) acrylic acid ester having an alicyclic structure in the molecule, structural units derived from a styrene monomer, structural units derived from a vinyl monomer, a plurality of (meth) acrylic A structural unit derived from a monomer having a di (meth) acrylamide group, and a structural unit derived from a (meth) acrylamide compound. The other monomers may be used alone, or two or more monomers may be used in combination.

The alicyclic structure in the (meth) acrylic acid ester having an alicyclic structure in the molecule means a cycloparaffin structure having a carbon number of usually 5 or more, preferably 5 to 7 or so. Specific examples of the (meth) acrylic acid ester having an alicyclic structure include (meth) acrylic acid esters such as isobornyl acrylate, cyclohexyl (meth) acrylate, dicyclopentanyl (meth) acrylate, cyclododecyl Methylcyclohexyl, trimethylcyclohexyl (meth) acrylate, t-butylcyclohexyl (meth) acrylate, cyclohexylphenyl (meth) acrylate, cyclohexyl α-ethoxyacrylate and the like.

Specific examples of the styrene-based monomer include styrene; Alkylstyrenes such as methylstyrene, dimethylstyrene, trimethylstyrene, ethylstyrene, diethylstyrene, triethylstyrene, propylstyrene, butylstyrene, hexylstyrene, heptylstyrene and octylstyrene; Halogenated styrenes such as fluorostyrene, chlorostyrene, bromostyrene, dibromostyrene and iodostyrene; Nitrostyrene, acetylstyrene, methoxystyrene, divinylbenzene, and the like.

Specific examples of the vinyl monomer include fatty acid vinyl esters such as vinyl acetate, vinyl propionate, vinyl butyrate, vinyl 2-ethylhexanoate and vinyl laurate; Vinyl halides such as vinyl chloride and vinyl bromide; Vinylidene halides such as vinylidene chloride; Nitrogen-containing aromatic vinyls such as vinylpyridine, vinylpyrrolidone and vinylcarbazole; Conjugated diene monomers such as butadiene, isoprene, and chloroprene; Acrylonitrile, methacrylonitrile and the like.

Specific examples of the monomer having a plurality of (meth) acryloyl groups in the molecule include 1,4-butanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, (Meth) acrylate such as ethylene glycol di (meth) acrylate, ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate and tripropylene glycol di A monomer having a (meth) acryloyl group; Monomers having three (meth) acryloyl groups in the molecule such as trimethylolpropane tri (meth) acrylate, and the like.

Specific examples of the (meth) acrylamide compound include N-methylol (meth) acrylamide, N- (2-hydroxyethyl) (meth) acrylamide, N- (3-hydroxypropyl) (Meth) acrylamide, N- (5-hydroxypentyl) (meth) acrylamide, N- (4-hydroxybutyl) (Meth) acrylamide, N, N-diethyl (meth) acrylamide, N-isopropyl (meth) acrylamide, N- (3-dimethylaminopropyl) (Meth) acrylamide, N- [2- (2-oxo-1-imidazolidinyl) ethyl] (meth) acrylamide, 2-acryloylamino- (Methoxymethyl) acrylamide, N- (ethoxymethyl) (meth) acrylamide, N- (propoxymethyl) (meth) acrylamide, N- (1-methylethoxymethyl ) (Meth) acrylamide, N- (1-methylpropoxymethyl) (meth) acrylamide, N- (Methoxymethyl) (meth) acrylamide [alias: N- (isobutoxymethyl) (meth) acrylamide], N- (butoxymethyl) (meth) acrylamide, N- (1,1-dimethylethoxymethyl (Meth) acrylamide, N- (2-ethoxyethyl) (meth) acrylamide, N- (2-methoxyethyl) Amide, N- [2- (1-methylethoxy) ethyl] (meth) acrylamide, N- [2- (1-methylpropoxy) ethyl] (Meth) acrylamide, N- (2-butoxyethyl) (meth) acrylamide, N- (2-butoxyethyl) (1,1-dimethylethoxy) ethyl] (meth) acrylamide, and the like. Among them, preferred are N- (methoxymethyl) acrylamide, N- (ethoxymethyl) acrylamide, N- (propoxymethyl) acrylamide, N- (butoxymethyl) Hydroxy-methyl) < / RTI > acrylamide is preferably used.

The (meth) acrylic resin (A) generally contains 0 to 20% by weight, preferably 0 to 10% by weight, of other monomers among all the constitutional units constituting the (meth) acrylic resin (A).

The pressure-sensitive adhesive composition may contain two or more (meth) acrylic resins belonging to the (meth) acrylic resin (A). Further, the pressure-sensitive adhesive composition may contain another (meth) acrylic resin different from the (meth) acrylic resin (A). Examples of other (meth) acrylic resins are (meth) acrylic resins having a structural unit derived from a (meth) acrylic acid ester of formula (I) and having no polar functional group. The content of the (meth) acrylic resin (A) in the total of the (meth) acrylic resins is preferably 60 wt% or less, more preferably 60 wt% % Or more, more preferably 80 wt% or more, and further preferably 90 wt% or more.

(Meth) acrylic resin (A) has a glass transition temperature (Tg) measured by a differential scanning calorimeter (DSC) of -55 캜 or higher, preferably -50 캜 or higher. According to the pressure-sensitive adhesive composition of the present invention containing the (meth) acrylic resin (A) having a Tg of -55 캜 or higher, the adhesion between the pressure-sensitive adhesive layer and the optical member and the durability of the pressure-sensitive adhesive layer can be improved. The Tg of the (meth) acrylic resin (A) is usually -20 占 폚 or lower, preferably -25 占 폚 or lower, and more preferably -30 占 폚 or lower, from the viewpoint of adhesion between the pressure-

The (meth) acrylic resin (A) preferably has a weight average molecular weight (Mw) in terms of standard polystyrene by gel permeation chromatography (GPC) in the range of 500,000 to 2,000,000, Is more preferable. When Mw is 500,000 or more, the adhesion between the pressure-sensitive adhesive layer and the optical member under a high-temperature and high-humidity environment is improved, and the possibility of floating or peeling between the pressure-sensitive adhesive layer and the optical member tends to decrease. Is likely to be improved. If the Mw is less than 2,000,000, even if the dimensions of the optical member are changed when the pressure-sensitive adhesive layer is bonded to the optical member, the pressure-sensitive adhesive layer tends to follow the dimensional change, There is no difference between the brightness at the periphery of the liquid crystal cell and the brightness at the center when the optical member with a pressure-sensitive adhesive layer is applied to a liquid crystal display device due to the following property, The smear tends to be suppressed. The molecular weight distribution represented by the ratio (Mw / Mn) of the weight average molecular weight (Mw) to the number average molecular weight (Mn) is usually about 2 to 10, preferably 3 to 8.

The (meth) acrylic resin (A) and other (meth) acrylic resins optionally usable in combination can be produced by a known method such as a solution polymerization method, a bulk polymerization method, a suspension polymerization method and an emulsion polymerization method . In the production of the (meth) acrylic resin, usually a polymerization initiator is used. The polymerization initiator is used in an amount of 0.001 to 5 parts by weight based on 100 parts by weight of the total amount of all the monomers used in the production of the (meth) acrylic resin. The (meth) acrylic resin may be produced by a method in which the polymerization is proceeded by an active energy ray such as ultraviolet rays.

As the polymerization initiator, a thermal polymerization initiator, a photopolymerization initiator, and the like are used. Examples of the photopolymerization initiator include 4- (2-hydroxyethoxy) phenyl (2-hydroxy-2-propyl) ketone and the like. As the thermal polymerization initiator, for example, 2,2'-azobisisobutylonitrile, 2,2'-azobis (2-methylbutyronitrile), 1,1'-azobis (cyclohexane-1-carbonitrile Azo compounds such as 2,2'-azobis (2,4-dimethylvaleronitrile), 2,2'-azobis (2,4-dimethyl-4-methoxy valeronitrile) Azo compounds such as azobis (2-methylpropionate) and 2,2'-azobis (2-hydroxymethylpropionitrile); Butyl peroxide, lauryl peroxide, tert-butyl hydroperoxide, benzoyl peroxide, tert-butyl peroxybenzoate, cumene hydroperoxide, diisopropyl peroxydicarbonate, dipropyl peroxydicarbonate, Organic peroxides such as neodecanoate, tert-butyl peroxypivalate, (3,5,5-trimethylhexanoyl) peroxide; And inorganic peroxides such as potassium persulfate, ammonium persulfate, and hydrogen peroxide. A redox-type initiator using a peroxide and a reducing agent in combination may also be used as a polymerization initiator.

As the production method of the (meth) acrylic resin, the solution polymerization method is preferable among the above-mentioned methods. An example of the solution polymerization method is to mix a monomer and an organic solvent to be used, add a thermal polymerization initiator under a nitrogen atmosphere, and stir at about 40 to 90 占 폚, preferably about 50 to 80 占 폚, for about 3 to 15 hours. In order to control the reaction, a monomer or a thermal polymerization initiator may be added continuously or intermittently during the polymerization, or may be added while being dissolved in an organic solvent. Examples of the organic solvent include aromatic hydrocarbons such as toluene and xylene; Esters such as ethyl acetate and butyl acetate; Aliphatic alcohols such as propyl alcohol and isopropyl alcohol; Ketones such as acetone, methyl ethyl ketone and methyl isobutyl ketone, and the like.

[2] Isocyanate-based crosslinking agent (B)

The pressure-sensitive adhesive composition further contains an isocyanate-based crosslinking agent (B). The isocyanate crosslinking agent (B) is an isocyanate crosslinking agent having two or more isocyanate groups in the molecule and at least one isocyanate group bonded to a carbon atom constituting the aliphatic skeleton. By using such an isocyanate crosslinking agent (B) as a crosslinking agent, the adhesion between the pressure-sensitive adhesive layer and the optical member and the durability of the pressure-sensitive adhesive layer can be enhanced.

The aliphatic skeleton means a skeleton other than an aromatic ring. For example, the aliphatic skeleton includes an alicyclic structure in addition to a chain or branched hydrocarbon group. The isocyanate-based crosslinking agent (B) may contain an aromatic ring as long as it has an isocyanate group bonded to the carbon atom constituting the aliphatic skeleton.

A suitable example of the isocyanate crosslinking agent (B) is an isocyanate crosslinking agent having an isocyanate group bonded to the carbon atom of the methylene group constituting the aliphatic skeleton.

The number of methylene groups constituting the aliphatic skeleton, that is, the number of carbon atoms constituting the aliphatic skeleton is usually 1 to 15, preferably 1 to 10.

Specific examples of the isocyanate-based crosslinking agent (B) are aliphatic isocyanate-based crosslinking agents composed of an aliphatic skeleton and containing no aromatic ring. Examples of the aliphatic isocyanate-based crosslinking agent include 1,6-hexamethylene diisocyanate, 1,4-tetramethylene diisocyanate, 2-methyl-1,5-pentane diisocyanate, 3- Cyclohexyldiisocyanate, hydrogenated tolylene diisocyanate, hydrogenated xylylene diisocyanate, hydrogenated diphenylmethane diisocyanate, hydrogenated tetramethylxylene diisocyanate, and the like.

Another specific example of the isocyanate-based crosslinking agent (B) is an isocyanate-based crosslinking agent having an isocyanate group bonded to a carbon atom constituting an aliphatic skeleton and containing an aromatic ring. Examples of such isocyanate-based crosslinking agents include xylylene diisocyanate and the like.

Among them, an aliphatic isocyanate-based crosslinking agent composed of an aliphatic skeleton and containing no aromatic ring is advantageous in further improving the adhesion between the pressure-sensitive adhesive layer and the optical member.

The isocyanate-based crosslinking agent (B) can be obtained by reacting the isocyanate compound with a polyhydric alcohol compound adduct (for example, adduct of trimethylolpropane), an isocyanurate compound, a biuret type compound, furthermore a polyether polyol or polyester polyol, Acrylate polyol, polybutadiene polyol, polyisoprene polyol, or the like, and derivatives thereof such as urethane prepolymer type isocyanate compounds. The isocyanate crosslinking agent (B) may be used alone, or two or more may be used in combination.

The content of the isocyanate crosslinking agent (B) is 0.1 to 1 part by weight, preferably 0.2 to 0.9 part by weight based on 100 parts by weight of the (meth) acrylic resin (A). If the content of the isocyanate crosslinking agent (B) is less than 0.1 part by weight, the adhesion between the pressure-sensitive adhesive layer and the optical member becomes insufficient depending on the material of the surface of the optical member on which the pressure-sensitive adhesive layer is laminated. Further, depending on the material of the surface of the optical member on which the pressure-sensitive adhesive layer is laminated, the durability when the pressure-sensitive adhesive layer is bonded to the optical member is lowered. If the content of the isocyanate-based crosslinking agent (B) exceeds 1 part by weight, the adhesiveness between the pressure-sensitive adhesive layer and the optical member becomes insufficient even if a sufficient curing time is given. In addition, the durability, particularly the heat resistance, of the pressure-sensitive adhesive layer when bonded to the optical member is reduced.

[3] The ionic compound (C)

The pressure-sensitive adhesive composition may further contain an ionic compound (C) as an antistatic agent for imparting antistatic properties to the pressure-sensitive adhesive layer. The ionic compound (C) is a compound having an inorganic or organic cation and an inorganic or organic anion. Two or more kinds of ionic compounds (C) may be used.

Examples of inorganic cations, such as Li [Li ^+] cations, sodium cations [Na ^+], potassium cations alkali metal ions or cations beryllium [Be ^{2 +],} magnesium [Mg ^2+] cation, calcium cation, such as a [K ^+] And alkaline earth metal ions such as [Ca ^{2 +} ].

Examples of the organic cations include imidazolium cations, pyridinium cations, pyrrolidinium cations, ammonium cations, sulfonium cations and phosphonium cations.

Among the above cationic components, the organic cationic component is preferably used since it has excellent compatibility with the pressure-sensitive adhesive composition. Among the organic cation components, particularly the pyridinium cation and the imidazolium cation are preferably used from the viewpoint that it is difficult to charge the release film provided on the pressure-sensitive adhesive layer.

As the inorganic anion, e.g., chloride anion [Cl ^-], bromide anion [Br ^-], iodide anion [I ^-], tetrachloro-aluminate anion [AlCl ₄ ^-], heptamethylene Chlorodifluoromethane aluminate anion [Al ₂ Cl ₇ ^- ], tetrafluoroborate anion [BF ₄ ^- ], hexafluorophosphate anion [PF ₆ ^- ], perchlorate anion [ClO ₄ ^- ], nitrate anion [NO ₃ ^- ], hexafluoroacetate anion AsF ₆ ^- ], hexafluoroantimonate anion [SbF ₆ ^- ], hexafluoroniobate anion [NbF ₆ ^- ], hexafluorotantalate anion [TaF ₆ ^- ], dicyanamid anion [ ₂ N ^- ] and the like.

As the organic anions, for example, acetate anion [CH ₃ COO ^-], acetate anion trifluoroacetate [CF ₃ COO ^-], methane sulfonate anion [CH ₃ SO ₃ ^-], trifluoromethanesulfonate anion [CF ₃ SO ^_3], p- toluenesulfonate anion _{[p-CH 3 C 6 H 4} SO 3 - ], a bis (alkylsulfonyl fluorophenyl) imide anion [(FSO _{2) 2} N ^-], methane-bis (trifluoro sulfonyl) imide anion _{[(CF 3 SO 2) 2 N} - ], methanesulfonyl) bumetanide anion and tris (trifluoro _{[(CF 3 SO 2) 3 C} - ], dimethyl phosphinate anion [(CH _{3) 2} POO ^-], (poly) fluoro-dihydro fluoride anion [F (HF) _n ^-] (n is 1-3 or so), thiocyanate anion [SCN ^-], perfluoro butane sulfonate anion [C ₄ F ₉ SO ₃ ^- ], bis (pentafluoroethanesulfonyl) imide anion [(C ₂ F ₅ SO ₂ ) ₂ N ^- ], perfluorobutanoate anion [C ₃ F ₇ COO ^- ], (Methanesulfonyl trifluoromethyl) (trifluoromethanesulfonyl carbonyl) imide anion [(CF ₃ SO ₂₎ (CF ₃ CO) N ^-], perfluoro-1,3-propane sulfonate anion ^[- O ₃ S (CF ₂ ) ₃ SO ₃ ^- ], carbonate anion [CO ₃ ^2- ], and the like.

Among the above anion components, particularly anion components including a fluorine atom are preferably used because they give an ionic compound (C) having an excellent antistatic property. Specific examples thereof include bis (fluorosulfonyl) imide anion, hexafluorophosphate anion and bis (trifluoromethanesulfonyl) imide anion.

Concrete examples of the ionic compound (C) can be appropriately selected from the combination of the cationic component and the anionic component. Examples of the ionic compound (C) having an organic cation are classified and classified according to the structure of the organic cation, and the following can be cited.

Pyridinium salts:

N-hexylpyridinium hexafluorophosphate,

N-octylpyridinium hexafluorophosphate,

N-octyl-4-methylpyridinium hexafluorophosphate,

N-butyl-4-methylpyridinium hexafluorophosphate,

N-decalpyridinium bis (fluorosulfonyl) imide,

N-dodecylpyridinium bis (fluorosulfonyl) imide,

N-tetradecylpyridinium bis (fluorosulfonyl) imide,

N-hexadecylpyridinium bis (fluorosulfonyl) imide,

N-dodecyl-4-methylpyridinium bis (fluorosulfonyl) imide,

N-tetradecyl-4-methylpyridinium bis (fluorosulfonyl) imide,

N-hexadecyl-4-methylpyridinium bis (fluorosulfonyl) imide,

N-benzyl-2-methylpyridinium bis (fluorosulfonyl) imide,

N-benzyl-4-methylpyridinium bis (fluorosulfonyl) imide,

N-hexylpyridinium bis (trifluoromethanesulfonyl) imide,

N-octylpyridinium bis (trifluoromethanesulfonyl) imide,

N-octyl-4-methylpyridinium bis (trifluoromethanesulfonyl) imide,

N-butyl-4-methylpyridinium bis (trifluoromethanesulfonyl) imide.

Imidazolium salt:

1-ethyl-3-methylimidazolium hexafluorophosphate,

1-ethyl-3-methylimidazolium p-toluenesulfonate,

Ethyl-3-methylimidazolium bis (fluorosulfonyl) imide,

1-ethyl-3-methylimidazolium bis (trifluoromethanesulfonyl) imide,

1-butyl-3-methylimidazolium methanesulfonate,

1-butyl-3-methylimidazolium bis (fluorosulfonyl) imide.

Pyrrolidinium salt:

N-butyl-N-methylpyrrolidinium hexafluorophosphate,

N-butyl-N-methylpyrrolidinium bis (fluorosulfonyl) imide,

N-butyl-N-methylpyrrolidinium bis (trifluoromethanesulfonyl) imide.

Quaternary ammonium salts:

Tetrabutylammonium hexafluorophosphate, tetrabutylammonium hexafluorophosphate,

Tetrabutylammonium p-toluenesulfonate,

(2-hydroxyethyl) trimethylammonium bis (trifluoromethanesulfonyl) imide,

(2-hydroxyethyl) trimethylammonium dimethylphosphinate.

Examples of the ionic compound (C) having an inorganic cation include the following.

Lithium bromide,

Lithium iodide,

Lithium tetrafluoroborate,

Lithium hexafluorophosphate,

Lithium thiocyanate,

Lithium perchlorate,

Lithium trifluoromethanesulfonate,

Lithium bis (fluorosulfonyl) imide

Lithium bis (trifluoromethanesulfonyl) imide,

Lithium bis (pentafluoroethanesulfonyl) imide,

Lithium tris (trifluoromethanesulfonyl) methanide,

Lithium p-toluenesulfonate,

Sodium hexafluorophosphate,

Sodium bis (fluorosulfonyl) imide,

Sodium bis (trifluoromethanesulfonyl) imide,

Sodium p-toluenesulfonate,

Potassium hexafluorophosphate,

Potassium bis (fluorosulfonyl) imide,

Potassium bis (trifluoromethanesulfonyl) imide,

Potassium p-toluenesulfonate.

The ionic compound (C) is preferably a solid at room temperature. The antistatic performance can be maintained for a long period of time as compared with the case where the ionic compound (C) which is a liquid at ordinary temperature is used. From the viewpoint of long-term stability of such antistatic property, it is preferable that the ionic compound (C) has a melting point of 30 占 폚 or higher, more preferably 35 占 폚 or higher. On the other hand, if the melting point is too high, the compatibility with the (meth) acrylic resin (A) becomes poor, so the melting point is preferably 90 ° C or lower, more preferably 70 ° C or lower, further preferably 50 ° C or lower.

The content of the ionic compound (C) in the pressure-sensitive adhesive composition is preferably 0.2 to 8 parts by weight, more preferably 0.2 to 5 parts by weight based on 100 parts by weight of the (meth) acrylic resin (A) More preferably 0.3 to 5 parts by weight, particularly preferably 0.5 to 3 parts by weight. When the content of the ionic compound (C) is 0.2 parts by weight or more, it is advantageous to improve antistatic performance, and when it is 8 parts by weight or less, it is advantageous to maintain the durability of the pressure-sensitive adhesive layer.

[4] The silane compound (D)

The pressure-sensitive adhesive composition may further contain a silane compound (D). As a result, the adhesion between the pressure-sensitive adhesive layer and the optical member such as a glass substrate can be enhanced.

Examples of the silane compound (D) include vinyltrimethoxysilane, vinyltriethoxysilane, vinyltris (2-methoxyethoxy) silane, N- (2-aminoethyl) -3-aminopropylmethyldimethoxysilane , N- (2-aminoethyl) -3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-chloropropylmethyldimethoxysilane, 3-chloropropyltrimethoxysilane, 3-methacryloyloxypropyltrimethoxysilane, 3- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 3- Glycidoxypropyltrimethoxysilane, mercaptopropyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-glycidoxypropyldimethoxymethylsilane, 3-glycidoxypropylethoxydimethyl Silane, and the like. Two or more kinds of silane compounds may be used.

The silane compound (D) may be a silicone oligomer type. Examples of the silicone oligomer in the form of a (monomer) oligomer include the following.

3-mercaptopropyltrimethoxysilane-tetramethoxysilane copolymer,

3-mercaptopropyltrimethoxysilane-tetraethoxysilane copolymer,

3-mercaptopropyltriethoxysilane-tetramethoxysilane copolymer,

A mercaptopropyl group-containing copolymer such as 3-mercaptopropyltriethoxysilane-tetraethoxysilane copolymer;

Mercaptomethyltrimethoxysilane-tetramethoxysilane copolymer,

Mercaptomethyltrimethoxysilane-tetraethoxysilane copolymer,

Mercaptomethyltriethoxysilane-tetramethoxysilane copolymer,

A mercaptomethyl group-containing copolymer such as a mercaptomethyltriethoxysilane-tetraethoxysilane copolymer;

3-glycidoxypropyltrimethoxysilane-tetramethoxysilane copolymer,

3-glycidoxypropyltrimethoxysilane-tetraethoxysilane copolymer,

3-glycidoxypropyltriethoxysilane-tetramethoxysilane copolymer,

3-glycidoxypropyltriethoxysilane-tetraethoxysilane copolymer,

3-glycidoxypropylmethyldimethoxysilane-tetramethoxysilane copolymer,

3-glycidoxypropylmethyldimethoxysilane-tetraethoxysilane copolymer,

3-glycidoxypropylmethyldiethoxysilane-tetramethoxysilane copolymer,

Copolymers containing 3-glycidoxypropyl groups such as 3-glycidoxypropylmethyldiethoxysilane-tetraethoxysilane copolymer;

3-methacryloyloxypropyltrimethoxysilane-tetramethoxysilane copolymer,

3-methacryloyloxypropyltrimethoxysilane-tetraethoxysilane copolymer,

3-methacryloyloxypropyltriethoxysilane-tetramethoxysilane copolymer,

3-methacryloyloxypropyltriethoxysilane-tetraethoxysilane copolymer,

3-methacryloyloxypropylmethyldimethoxysilane-tetramethoxysilane copolymer,

3-methacryloyloxypropylmethyldimethoxysilane-tetraethoxysilane copolymer,

3-methacryloyloxypropylmethyldiethoxysilane-tetramethoxysilane copolymer,

Copolymers containing methacryloyloxypropyl groups such as 3-methacryloyloxypropylmethyldiethoxysilane-tetraethoxysilane copolymer;

3-acryloyloxypropyltrimethoxysilane-tetramethoxysilane copolymer,

3-acryloyloxypropyltrimethoxysilane-tetraethoxysilane copolymer,

3-acryloyloxypropyltriethoxysilane-tetramethoxysilane copolymer,

3-acryloyloxypropyltriethoxysilane-tetraethoxysilane copolymer,

3-acryloyloxypropylmethyldimethoxysilane-tetramethoxysilane copolymer,

3-acryloyloxypropylmethyldimethoxysilane-tetraethoxysilane copolymer,

3-acryloyloxypropylmethyldiethoxysilane-tetramethoxysilane copolymer,

Copolymers containing acryloyloxypropyl groups such as 3-acryloyloxypropylmethyldiethoxysilane-tetraethoxysilane copolymer;

Vinyltrimethoxysilane-tetramethoxysilane copolymer,

Vinyltrimethoxysilane-tetraethoxysilane copolymer,

Vinyltriethoxysilane-tetramethoxysilane copolymer,

Vinyltriethoxysilane-tetraethoxysilane copolymer,

Vinyl methyl dimethoxysilane-tetramethoxysilane copolymer,

Vinyl methyl dimethoxysilane-tetraethoxysilane copolymer,

Vinyl methyldiethoxysilane-tetramethoxysilane copolymer,

Vinyl-containing copolymers such as vinyl methyldiethoxysilane-tetraethoxysilane copolymer;

3-aminopropyltrimethoxysilane-tetramethoxysilane copolymer,

3-aminopropyltrimethoxysilane-tetraethoxysilane copolymer,

3-aminopropyltriethoxysilane-tetramethoxysilane copolymer,

3-aminopropyltriethoxysilane-tetraethoxysilane copolymer,

3-aminopropylmethyldimethoxysilane-tetramethoxysilane copolymer,

3-aminopropylmethyldimethoxysilane-tetraethoxysilane copolymer,

3-aminopropylmethyldiethoxysilane-tetramethoxysilane copolymer,

Amino group-containing copolymers such as 3-aminopropylmethyldiethoxysilane-tetraethoxysilane copolymer, and the like.

Most of the silane compounds (D) exemplified above are liquids. The content of the silane compound (D) in the pressure-sensitive adhesive composition is usually 0.01 to 10 parts by weight, preferably 0.05 to 5 parts by weight, per 100 parts by weight of the (meth) acrylic resin (A) 0.2 to 0.4 parts by weight. If the content of the silane compound (D) is 0.01 parts by weight or more, the effect of improving the adhesion between the pressure-sensitive adhesive layer and optical members such as a glass substrate can be easily obtained. When the content is 10 parts by weight or less, bleeding-out of the silane compound (D) from the pressure-sensitive adhesive layer can be suppressed.

[5] Other components

The pressure sensitive adhesive composition may contain additives such as a crosslinking catalyst, a weathering stabilizer, a tackifier, a plasticizer, a softener, a dye, a pigment, an inorganic filler, a light scattering fine particle and a resin other than the (meth) acrylic resin (A) . In addition, it is also useful to blend an ultraviolet curable compound into the pressure-sensitive adhesive composition to form a pressure-sensitive adhesive layer, and then cure by irradiating ultraviolet rays to form a harder pressure-sensitive adhesive layer. Examples of the crosslinking catalyst include amine compounds such as hexamethylenediamine, ethylenediamine, polyethyleneimine, hexamethylenetetramine, diethylenetriamine, triethylenetetramine, isophoronediamine, trimethylenediamine, polyamino resin and melamine resin .

<Pressure-sensitive adhesive layer>

The pressure-sensitive adhesive layer according to the present invention includes the pressure-sensitive adhesive composition according to the present invention described above, and typically comprises the pressure-sensitive adhesive composition according to the present invention. The pressure-sensitive adhesive layer can be obtained by dissolving or dispersing each component constituting the pressure-sensitive adhesive composition in a solvent to prepare a pressure-sensitive adhesive composition containing a solvent, and then applying the pressure-sensitive adhesive composition on a base film and drying. The pressure-sensitive adhesive layer according to the present invention is excellent in adhesion and durability.

The base film is generally a plastic film, and a typical example thereof is a release film (separator) subjected to release treatment. The release film may be a release treatment such as a silicone treatment applied to a surface of a film formed of various resins such as polyethylene terephthalate, polybutylene terephthalate, polycarbonate, and polyalate, on which the pressure-sensitive adhesive layer is formed . For example, an optical member with a pressure-sensitive adhesive layer can be obtained by directly applying a pressure-sensitive adhesive composition onto a release-treated surface of a release film to form a pressure-sensitive adhesive layer and laminating the pressure- Further, the pressure-sensitive adhesive composition may be directly applied to the surface of the optical member to form a pressure-sensitive adhesive layer, and if necessary, a release film may be laminated on the outer surface of the pressure-sensitive adhesive layer to provide an optical member with a pressure- When the pressure-sensitive adhesive layer is provided on the surface of the optical member, surface activation treatment such as plasma treatment, corona treatment or the like is preferably performed on the bonding surface of the optical member and / or the bonding surface of the pressure-sensitive adhesive layer, desirable.

The thickness of the pressure-sensitive adhesive layer is preferably 10 to 45 占 퐉, more preferably 10 to 30 占 퐉, and further preferably 10 to 20 占 퐉. When the thickness of the pressure-sensitive adhesive layer is within this range, the adhesion between the pressure-sensitive adhesive layer and the optical member and the durability when the pressure-sensitive adhesive layer is bonded to the optical member are advantageous. For the same reason, the pressure-sensitive adhesive layer preferably has a gel fraction of 30 to 85%.

<Optical member with pressure-sensitive adhesive layer>

The pressure-sensitive adhesive layer according to the present invention can be suitably used as a pressure-sensitive adhesive layer for bonding members, particularly optical members. The optical member with a pressure-sensitive adhesive layer according to the present invention may be, for example, one in which a pressure-sensitive adhesive layer is laminated on an optical member, and another optical member is laminated on the outer surface of the pressure-sensitive adhesive layer.

[1] First Embodiment

One preferred embodiment of the optical member with a pressure-sensitive adhesive layer according to the present invention comprises a resin film as an optical member and a pressure-sensitive adhesive layer laminated on at least one surface thereof. The resin film is a surface protective film (protective film) which is bonded to an optical film such as a polarizer, a protective film and a retardation film, an optical film to be protected, and the like and used for protecting the surface from scratches and contamination.

A polarizer is a film having a function of extracting linearly polarized light from incident natural light, and a suitable example is that a dichroic dye such as iodine or a dichroic dye is adsorbed and aligned on a uniaxially stretched polyvinyl alcohol resin film. The thickness of the polarizer is not particularly limited, but is usually 0.5 to 35 탆.

The protective film may be a polyolefin resin such as a translucent (preferably optically transparent) resin such as a chain polyolefin resin (polypropylene resin), a cyclic polyolefin resin (norbornene resin, etc.); Cellulose-based resins such as triacetylcellulose and diacetylcellulose; Polyester-based resin; Polycarbonate resin; (Meth) acrylic resins; Polystyrene type resin; Polyether ether ketone resins; And a film made of a thermoplastic resin such as a polysulfone resin.

Examples of the chain polyolefin-based resin include a homopolymer of a chain olefin such as a polyethylene resin and a polypropylene resin, and a copolymer composed of two or more chain olefins.

The cyclic polyolefin-based resin is a generic name of a resin that is polymerized using a cyclic olefin as a polymerization unit. Specific examples of the cyclic polyolefin-based resin include ring-opened (co) polymers of cyclic olefins, addition polymers of cyclic olefins, copolymers (typically, random copolymers) of cyclic olefins and chain olefins such as ethylene and propylene, Graft polymers modified with carboxylic acids and derivatives thereof, and hydrides thereof. Among them, a norbornene resin using a norbornene monomer such as norbornene or a polycyclic norbornene monomer as the cyclic olefin is preferably used.

The cellulose-based resin is a partial or complete esterified product of cellulose, and examples thereof include acetic acid ester, propionic acid ester, butyric acid ester and mixed ester thereof of cellulose. Among them, triacetylcellulose, diacetylcellulose, cellulose acetate propionate, cellulose acetate butyrate and the like are preferably used.

The polyester-based resin is a resin other than the cellulose-based resin having an ester bond, and is generally composed of a polycondensation product of a polyvalent carboxylic acid or a derivative thereof and a polyhydric alcohol. As the polycarboxylic acid or its derivative, a dicarboxylic acid or a derivative thereof can be used, and examples thereof include terephthalic acid, isophthalic acid, dimethylterephthalate, and dimethyl naphthalenedicarboxylate. Examples of polyhydric alcohols include diols such as ethylene glycol, propanediol, butanediol, neopentyl glycol, and cyclohexanedimethanol.

Specific examples of the polyester-based resin include polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, polytrimethylene terephthalate, polytrimethylene naphthalate, polycyclohexanedimethyl terephthalate, polycyclohexane Dimethyl naphthalate.

The polycarbonate resin is composed of a polymer to which a monomer unit is bonded through a carbonate group. The polycarbonate resin may be a modified polycarbonate such as modified polymer skeleton, or a copolymerized polycarbonate.

The (meth) acrylic resin may be a polymer having methacrylic acid ester as a main monomer, and is preferably a copolymer in which a small amount of another comonomer component is copolymerized. The (meth) acrylic resin is more preferably a copolymer of methyl methacrylate and methyl acrylate, and the third mono-functional monomer may be further copolymerized.

Examples of the third mono-functional monomer include ethyl methacrylate, butyl methacrylate, cyclohexyl methacrylate, phenyl methacrylate, benzyl methacrylate, 2-ethylhexyl methacrylate, 2- Methacrylic acid esters other than methyl methacrylate such as ethyl; Acrylic acid esters such as ethyl acrylate, butyl acrylate, cyclohexyl acrylate, phenyl acrylate, benzyl acrylate, 2-ethylhexyl acrylate, and 2-hydroxyethyl acrylate; Hydroxyalkyl acrylate esters such as methyl 2- (hydroxymethyl) acrylate, methyl 2- (1-hydroxyethyl) acrylate, ethyl 2- (hydroxymethyl) acrylate and butyl 2- (hydroxymethyl) acrylate; Unsaturated acids such as methacrylic acid and acrylic acid; Halogenated styrenes such as chlorostyrene and bromostyrene; Substituted styrenes such as vinyltoluene and? -Methylstyrene; Unsaturated nitriles such as acrylonitrile and methacrylonitrile; Unsaturated acid anhydrides such as maleic anhydride and citraconic anhydride; And unsaturated imides such as phenylmaleimide and cyclohexylmaleimide. The third monofunctional monomer may be used alone, or two or more monofunctional monomers may be used in combination.

A polyfunctional monomer may be further copolymerized with the (meth) acrylic resin. Examples of the polyfunctional monomer include ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) (Meth) acrylate, and tetradecaethylene glycol di (meth) acrylate, esterified with acrylic acid or methacrylic acid at both terminal hydroxyl groups of the oligomer; Propylene glycol or its oligomer with both terminal hydroxyl groups being esterified with acrylic acid or methacrylic acid; Acrylate, neopentyl glycol di (meth) acrylate, hexanediol di (meth) acrylate and butanediol di (meth) acrylate esterified with acrylic acid or methacrylic acid; Bisphenol A, an alkylene oxide adduct of bisphenol A, or both terminal hydroxyl groups of the halogen substituents thereof esterified with acrylic acid or methacrylic acid; Trimethylol propane and pentaerythritol esterified with acrylic acid or methacrylic acid, and those in which epoxy groups of glycidyl acrylate or glycidyl methacrylate are added to these terminal hydroxyl groups by ring opening; A dibasic acid such as succinic acid, adipic acid, terephthalic acid, phthalic acid, and halogen substituents thereof, and an alkylene oxide adduct thereof, and the like, in which an epoxy group of glycidyl acrylate or glycidyl methacrylate is ring- Aryl (meth) acrylate; And aromatic divinyl compounds such as divinylbenzene. Among them, ethylene glycol dimethacrylate, tetraethylene glycol dimethacrylate and neopentyl glycol dimethacrylate are preferably used.

The (meth) acrylic resin may also be modified by a reaction between the functional groups of the copolymer. Examples of the reaction include a condensation reaction in a polymer chain between a methyl ester group of methyl acrylate and a hydroxyl group of 2- (hydroxymethyl) acrylate, a condensation reaction between a carboxyl group of acrylic acid and a hydroxyl group of 2- (hydroxymethyl) A dehydration condensation reaction in a polymer chain, and the like. The (meth) acrylic resin may have any structure of a glutarimide derivative, a glutaric acid anhydride derivative or a lactone ring structure.

The (meth) acrylic resin may contain additives as required. Examples of additives include lubricants, antiblocking agents, heat stabilizers, antioxidants, antistatic agents, light stabilizers, impact resistance improvers, surfactants and the like.

The (meth) acrylic resin may contain acrylic rubber particles from the viewpoints of the film formability to the film and the impact resistance of the film. The acrylic rubber particles are particles composed of an elastomer mainly composed of an acrylate ester as an essential component and substantially a single layer structure composed of only this elastomer but a multi layer structure composed of this elastomer as a single layer. As an example of the elastic polymer, a crosslinked elastic copolymer comprising an alkyl acrylate as a main component and another copolymerizable vinyl monomer and a crosslinkable monomer are copolymerized. Examples of the alkyl acrylate which is the main component of the elastomer include alkyl acrylates such as methyl acrylate, ethyl acrylate, butyl acrylate and 2-ethylhexyl acrylate, and the alkyl groups having 1 to 8 carbon atoms. Is preferably used. Examples of other vinyl monomers copolymerizable with the alkyl acrylate include compounds having one polymerizable carbon-carbon double bond in the molecule, and more specifically, methacrylic acid esters such as methyl methacrylate, Aromatic vinyl compounds, and vinyl cyan compounds such as acrylonitrile. Examples of the crosslinkable monomer include crosslinkable compounds having at least two polymerizable carbon-carbon double bonds in the molecule, and more specifically, ethylene glycol di (meth) acrylate, butanediol di (meth) acrylate and (Meth) acrylates of the same polyhydric alcohol, alkenyl esters of (meth) acrylic acid such as allyl (meth) acrylate, and divinylbenzene.

A laminate of a film made of a (meth) acrylic resin containing no rubber particles and a film made of a (meth) acrylic resin containing rubber particles may be used as a protective film.

The retardation film is an optical film exhibiting optical anisotropy. In addition to the resin that can be used for the protective film, the retardation film may be formed of a resin such as polyvinyl alcohol resin, polyarylate resin, polyimide resin, polyether sulfone resin, A stretched film obtained by stretching a resin film comprising a rid / polymethyl methacrylate resin, a liquid crystal polyester resin, a saponified ethylene-vinyl acetate copolymer, and a polyvinyl chloride resin to a degree of 1.01 to 6 times. Among them, a polycarbonate resin film, a cycloolefin resin film, a (meth) acrylic resin film, or a stretched film obtained by uniaxially or biaxially stretching a cellulose resin film is preferable. In this specification, a zero retardation film is also included in the retardation film (however, it may also be used as a protective film). In addition, a film called a uniaxial retardation film, a wide viewing angle retardation film, and a low elasticity modulus retardation film can also be applied as a retardation film.

The zero retardation film refers to a film having an in-plane retardation value R _e and a thickness direction retardation value R _th together of -15 to 15 nm. This retardation film is suitably used for an IPS mode liquid crystal display device. The in-plane retardation value R _e and the thickness direction retardation value R _th are preferably -10 to 10 nm, more preferably -5 to 5 nm together. The in-plane phase difference value R _e and the thickness direction phase difference value R _th are values at a wavelength of 590 nm.

The in-plane phase difference value R _e and the thickness direction phase difference value R _th satisfy the following equations:

R _e = (n _x -n _y ) x d

R _th = _{[(n x + n y) /} 2-n z × d]

. Expression, n _x is a refractive index in a slow axis direction (x axis direction) in the film plane, n _y is a refractive index in the fast axis direction (y-axis direction perpendicular to the x-axis in-plane) in the film plane, n _z is the thickness of the film (Z-axis direction perpendicular to the film plane), and d is the thickness of the film.

As the zero retardation film, for example, a resin film made of a polyolefin resin such as a cellulose resin, a chain polyolefin resin and a cyclic polyolefin resin, a polyethylene terephthalate resin or a (meth) acrylic resin can be used. Particularly, a cellulose resin, a polyolefin resin or a (meth) acrylic resin is preferably used since it is easy to control the phase difference and is easily available. For example, a retardation film may be obtained by laminating a (meth) acrylic resin on one side or both sides of a retardation developing layer made of a resin different from the (meth) acrylic resin.

A film exhibiting optical anisotropy by application and orientation of a liquid crystalline compound or a film exhibiting optical anisotropy by application of an inorganic layered compound can also be used as a retardation film. Such a retardation film is called a temperature compensation type retardation film or a film in which a rod-shaped liquid crystal sold under the trade name of &quot; NH film &quot; by JX Nikkoseki Energie Co., A full biaxially oriented film sold by Sumitomo Chemical Co. under the trade name of &quot; VAC film &quot;, a film with a disk-shaped liquid crystal sold under the trade name &quot; WV Film &quot;Quot; new VAC film &quot;).

On the other hand, the surface protective film is a film used for the purpose of protecting the surface of an optical film or the like to be protected against scratches or contamination. For example, a polarizer, a protective film, a retardation film, , Reflective sheet and the like are usually distributed in a state in which a surface protective film is adhered to the surface thereof (the surface opposite to the pressure-sensitive adhesive layer in the case of having a pressure-sensitive adhesive layer on one surface). The surface protective film is usually peeled off after bonding the optical film to a liquid crystal cell or the like.

Examples of the base material of the surface protective film include polyolefin-based resins such as polyethylene, polypropylene and polymethylpentene; Fluorinated polyolefin-based resins such as polyvinyl fluoride, polyvinylidene fluoride, and polyfluorinated ethylene; Polyester resins such as polyethylene naphthalate, polyethylene terephthalate, polybutylene terephthalate, and polyethylene terephthalate / isophthalate copolymer; Polyamides such as nylon 6, nylon 6,6; Vinyl polymers such as polyvinyl chloride, vinyl chloride-vinyl acetate copolymer, ethylene-vinyl acetate copolymer, ethylene-vinyl alcohol copolymer, polyvinyl alcohol and vinylon; Cellulose-based resins such as triacetylcellulose, diacetylcellulose, and cellophane; (Meth) acrylic resins such as methyl polymethacrylate, ethyl polymethacrylate, ethyl polyacrylate and butyl polyacrylate; Other examples include polystyrene, polycarbonate, polyarylate, and polyimide. The optical member with a pressure-sensitive adhesive layer according to the present invention, in which the resin film is a surface protective film, is provided with a pressure-sensitive adhesive layer on this substrate.

In the optical member with a pressure-sensitive adhesive layer according to the present embodiment, it is preferable that the above-mentioned release film is adhered to the surface of the pressure-sensitive adhesive layer and temporarily adhered and protected until used. The optical member with a pressure-sensitive adhesive layer according to the present embodiment in which the release film is adhered can be produced by a method in which a pressure-sensitive adhesive composition is applied on a release film to form a pressure-sensitive adhesive layer and further a resin film is laminated on the pressure- To form a pressure-sensitive adhesive layer, and then bonding the release film to the pressure-sensitive adhesive surface.

[2] Second Embodiment

Another preferred embodiment of the optical member with a pressure-sensitive adhesive layer according to the present invention comprises a laminate of a resin film and a pressure-sensitive adhesive layer laminated on at least one surface thereof. The laminate of the resin film is preferably a laminate of optical films selected from optical films such as polarizers, protective films, retardation films and the like. A typical example of the laminate of the optical film is a polarizing plate. Also in the optical member with a pressure-sensitive adhesive layer according to the present embodiment, it is preferable that a release film is adhered to the surface of the pressure-sensitive adhesive layer and temporarily adhered to the surface of the pressure-sensitive adhesive layer until use.

Examples of the polarizing plate include a linear polarizing plate that absorbs linearly polarized light having a vibration plane in any direction incident on the film surface and transmits linearly polarized light having a vibration plane orthogonal thereto and a linearly polarizing plate having a straight line having a vibration surface in any direction A polarized light separating plate having a property of reflecting polarized light and transmitting linearly polarized light having a vibration plane perpendicular to the polarized light, and an elliptically polarizing plate obtained by laminating a retardation film on a linearly polarizing plate.

The linearly polarizing plate generally has a structure in which the above-mentioned protective film is bonded to one or both sides of the above-mentioned polarizer. When a protective film is bonded to both surfaces of a polarizer, a pressure-sensitive adhesive layer can be formed on at least one surface of the protective film. When a protective film is bonded only to one side of the polarizer, a pressure-sensitive adhesive layer can be formed on the surface of the polarizer (the side where the protective film is not bonded). The elliptically polarizing plate is obtained by laminating a retardation film on a linearly polarizing plate, and the linearly polarizing plate generally has the same structure as the above. When the pressure-sensitive adhesive layer is laminated on the elliptically polarizing plate, an adhesive layer is usually laminated on the retardation film side.

Specific examples of the optical member with a pressure-sensitive adhesive layer in the case where the optical member is a polarizing plate will be described with reference to the drawings. 1, the protective film 3 having the surface treatment layer 2 is adhered to one surface of the polarizer 1 on the surface opposite to the surface treatment layer 2 to form the polarizing plate 10 Consists of. A pressure sensitive adhesive layer 20 is provided on the surface of the polarizer 1 opposite to the protective film 3 to constitute a polarizing plate with a pressure sensitive adhesive layer (optical member with a pressure sensitive adhesive layer) The pressure-sensitive adhesive layer 20 can be bonded to the glass substrate 30 on the side opposite to the polarizing plate 5, but the glass substrate 30 will be described later.

The polarizing plate 25 with a pressure-sensitive adhesive layer shown in Fig. 2 is the same as that of Fig. 1 except that the polarizing plate 10 includes a second protective film 4 adhered to the other surface of the polarizer 1. The pressure-sensitive adhesive layer (20) is laminated on the outer surface of the second protective film (4). 3 except that the polarizing plate 10 includes a retardation film 7 adhered to the other surface of the polarizer 1 through the interlayer adhesive 8, same. 4 except that the polarizing plate 10 includes the retardation film 7 bonded to the outer surface of the second protective film 4 through the interlayer adhesive 8, 2 &lt; / RTI &gt; In the example shown in Figs. 3 and 4, the pressure-sensitive adhesive layer 20 is bonded to the retardation film 7. Fig.

The surface treatment layer 2 formed on the surface of the protective film 3 may be a hard coat layer, an antiglare layer, an antireflection layer, an antistatic layer, or the like. A plurality of layers may be provided. As a suitable example of the retardation film 7, if the polarizing plate 10 includes the retardation film 7 as in the example shown in Figs. 3 and 4, if it is a small-sized liquid crystal display, For example. In this case, it is general to arrange the absorption axis of the polarizer 1 and the slow axis of the retardation film 7 to intersect at approximately 45 degrees. However, when the angle is shifted to some extent from 45 degrees according to the characteristics of the liquid crystal cell have. On the other hand, in a large-sized liquid crystal display device such as a television, a retardation film 7 having various retardation values is used in accordance with the characteristics of the liquid crystal cell for the purpose of compensating the retardation of the liquid crystal cell or compensating the viewing angle. In this case, it is general that the absorption axis of the polarizer 1 and the slow axis of the retardation film 7 are arranged to be almost orthogonal or substantially parallel. When the retardation film 7 is constituted by a 1/4 wavelength plate, a uniaxially or biaxially stretched film is suitably used. When the retardation film 7 is provided for compensation of phase difference of the liquid crystal cell or compensation of viewing angle, in addition to uniaxial or biaxially stretched film, a film aligned in the thickness direction in addition to uniaxial or biaxial stretching, Or the like, and an optical compensation film, such as a film obtained by orienting and fixing the retardation-developing substance, may be used as the retardation film 7.

It is usual to use a general (meth) acrylic pressure-sensitive adhesive for the interlayer pressure-sensitive adhesive 8 in FIGS. 3 and 4, but it is of course possible to form the pressure-sensitive adhesive layer according to the present invention. In the case where the absorption axis of the polarizer 1 and the slow axis of the retardation film 7 are arranged so as to be almost orthogonal or almost parallel to each other as in the above-mentioned large liquid crystal display device, It can also be used. Examples of the adhesive include an aqueous adhesive composed of an aqueous solution or an aqueous dispersion and exhibiting an adhesive force by evaporating water as a solvent, and an ultraviolet curable adhesive which is cured by irradiation of ultraviolet rays to develop an adhesive force. The polarizer 1 and the protective films 3 and 4 are usually joined to each other using an adhesive.

In the optical member with a pressure-sensitive adhesive layer according to the present embodiment, since the pressure-sensitive adhesive layer contains the pressure-sensitive adhesive composition according to the present invention, adhesion between the pressure-sensitive adhesive layer and the optical member and durability are good. According to the present invention, even if the surface of the optical member to which the pressure-sensitive adhesive layer is bonded is a surface that is not easily activated by a surface activation treatment that has been conventionally performed, such as corona treatment or plasma treatment, adhesion and durability of the pressure- An optical member with a pressure-sensitive adhesive layer can be obtained. The surface which is difficult to activate by the surface activation treatment is, for example, a surface having a contact angle change rate of not more than 40%, more preferably not more than 30% when subjected to a corona treatment. The contact angle change rate is usually 0.1% or more, preferably 0.5% or more.

The contact angle change rate is expressed by the following formula:

Contact angle change rate (%) = {(contact angle before corona treatment-contact angle after corona treatment) / contact angle before corona treatment} × 100

. The contact angle after the corona treatment is a contact angle when the surface is subjected to corona treatment once at a condition of output of 0.3 kW and a line speed of 10 m / min against the surface and then left for 24 hours in an environment of a temperature of 23 DEG C and a relative humidity of 60% . The contact angle is a contact angle with respect to water, and the unit is &quot; ° &quot;.

The rate of change of the contact angle when the corona treatment is performed differs depending on the constituent material of the surface of the optical member. Examples of the thermoplastic resin having a contact angle change ratio of 40% or less include (meth) acrylic resins, cellulose resins, polyester resins, polycarbonate resins and the like. The surface of the optical member made of the thermoplastic resin may be the surface of an optical film such as a protective film or a retardation film.

[3] Third Embodiment

Another preferred embodiment of the optical member with a pressure-sensitive adhesive layer according to the present invention is obtained by laminating another optical member on the outer surface of the pressure-sensitive adhesive layer in the optical member with a pressure-sensitive adhesive layer according to the first or second embodiment. The other optical member is preferably a glass substrate, and FIGS. 1 to 4 also show a state in which the polarizing plate with a pressure-sensitive adhesive layer according to the second embodiment is bonded to the glass substrate 30.

Examples of the glass substrate 30 include glass substrates for liquid crystal cells, antireflection glass, glass for sunglasses, and the like. Examples of the material of the glass substrate 30 include soda lime glass, low alkali glass, and alkali-free glass. Among them, the glass substrate is preferably a glass substrate of a liquid crystal cell.

In the liquid crystal cell, a polarizing plate is usually laminated on both sides thereof with a pressure-sensitive adhesive layer. Of these polarizing plates, only the polarizing plate disposed on the front side (viewing side) of the liquid crystal cell may be a polarizing plate with a pressure- (Backlight side) may be a polarizing plate with a pressure-sensitive adhesive layer according to the present invention, or both of them may be a polarizing plate with a pressure-sensitive adhesive layer according to the present invention. The driving method of the liquid crystal cell may be any conventionally known method. The polarizing plate disposed on the back side (backlight side) usually has no surface treatment layer 2. Various optical films known to be disposed on the back side of the liquid crystal cell, such as a brightness enhancement film, a light converging film, a diffusion film, etc., may be provided on the outer surface of the outer polarizer disposed on the back side.

The optical member with a pressure-sensitive adhesive layer such as a polarizer plate with a pressure-sensitive adhesive layer can be suitably used for a liquid crystal display device. The liquid crystal display device includes, for example, a personal computer including a notebook type, a desktop type, a PDA (Personal Digital Assistant), and the like; Various mobile devices such as smart phones and tablet type terminals; television; A vehicle-mounted display; Electronic Dictionary; digital camera; Digital video camera; Electronic desk calculator; It can be suitably used as a liquid crystal display device for a clock or the like.

Example

Hereinafter, the present invention will be described in more detail with reference to examples and comparative examples, but the present invention is not limited to these examples. Hereinafter, parts and% indicating amounts used or contents are based on weight unless specifically understood.

&Lt; Preparation Examples 1 to 9: Preparation of (meth) acrylic resin for pressure-sensitive adhesive layer >

A monomer mixture diluted with ethyl acetate having the monomer composition shown in Table 1 (wt% based on 100 wt% of all monomer) was injected into a reaction vessel equipped with a condenser, a nitrogen inlet tube, a thermometer and a stirrer , The inside of the apparatus was replaced with nitrogen gas to raise the internal temperature to 55 占 폚 while making oxygen-free. Thereafter, a total amount of a solution prepared by dissolving azobisisobutyronitrile (polymerization initiator) in ethyl acetate was added. Ethyl acetate was continuously added into the reaction vessel while the internal temperature was maintained at 54 to 56 DEG C, and when the concentration of the (meth) acrylic resin reached 35 wt%, acetic acid The addition of ethyl was stopped and the temperature was maintained at this temperature for 12 hours from the start of the addition of ethyl acetate. Finally, ethyl acetate was added to adjust the concentration of the (meth) acrylic resin to 20 wt% to prepare an ethyl acetate solution of the (meth) acrylic resin.

The weight average molecular weight (Mw) and glass transition temperature (Tg) of the obtained (meth) acrylic resin were measured. Mw is a column in a GPC apparatus, and four "TSKgel XL" manufactured by Toso Co., Ltd. and "Shodex GPC KF-802" manufactured by Showa Denko Corporation and sold by Shoko Tsusho Co., Were placed in series, and tetrahydrofuran was used as an eluent, and the measurement was carried out in terms of standard polystyrene at a sample concentration of 5 mg / mL, a sample introduction amount of 100 μL, a temperature of 40 ° C., and a flow rate of 1 mL / min. Tg was measured under the conditions of a measurement temperature range of -80 to 50 占 폚 and a temperature raising rate of 10 占 폚 / min under a nitrogen atmosphere using a differential scanning calorimeter (DSC) "DSC6000" manufactured by SII Eye Nanotechnology Co., The monomer composition (% by weight) of the monomer mixture used and the Mw and Tg of the (meth) acrylic resin obtained were integrated in Table 1.

The abbreviation in the column "monomer composition" in Table 1 means the following monomers.

BA: butyl acrylate,

EHA: 2-ethylhexyl acrylate,

MA: methyl acrylate,

AA: Acrylic acid,

HEA: 2-hydroxyethyl acrylate.

&Lt; Examples 1 to 10, Comparative Examples 1 to 4 >

(1) Preparation of pressure-sensitive adhesive composition

The crosslinking agent (B), the ionic compound (C) and the silane compound (D) shown in Table 2 were added to 100 parts by weight of the solid content of the (meth) acrylic resin (A) By weight), and ethyl acetate was added so that the solid concentration became 28% by weight to prepare a solution of the pressure-sensitive adhesive composition. The blending amounts of the respective blending ingredients shown in Table 2 are the number of blended parts as an active ingredient contained in the case where the used product includes a solvent and the like.

Details of each compounding ingredient represented by abbreviations in Table 2 are as follows.

B1: An ethyl acetate solution (solid concentration 75%) of trimethylolpropane adduct of m-xylylene diisocyanate, "Takenate D-110N" obtained from Mitsui Chemicals, Inc.,

B2: isocyanurate of hexamethylene diisocyanate, liquid of almost 100% of active ingredient, "Colonate HXR" obtained from Nippon Polyurethane Co., Ltd.,

B3: An ethyl acetate solution (solid concentration 75%) of trimethylolpropane adduct of tolylene diisocyanate, &quot; Colonate L &quot; obtained from Nippon Polyurethane Co.,

B4: An ethyl acetate solution (solid concentration 50%) of isocyanurate of tolylene diisocyanate, "Takenate D-204N" obtained from Mitsui Chemicals, Inc.,

C1: N-butyl-4-methylpyridinium hexafluorophosphate,

S1: 3-glycidoxypropyltrimethoxysilane, &quot; KBM403 &quot; obtained from Shin-Etsu Chemical Co., Ltd.

(2) Production of pressure-sensitive adhesive layer

Each of the pressure-sensitive adhesive compositions prepared in the above (1) was applied to a release-treated surface of a release film ("PLR-382051" obtained from Lintec Co., Ltd.) comprising a polyethylene terephthalate film subjected to release treatment, And dried at 100 캜 for 1 minute to prepare a pressure-sensitive adhesive layer (pressure-sensitive adhesive sheet).

(3) Production of Polarizer with Adhesive Layer

A polarizing plate was produced by adhering a protective film made of a thermoplastic resin described in Table 3 on both sides of a polarizer having a thickness of 23 占 퐉 in which iodine was adsorbed and aligned on a uniaxially stretched polyvinyl alcohol film with an adhesive. Subsequently, a surface (pressure-sensitive adhesive layer side) opposite to the separator in the pressure-sensitive adhesive layer prepared in the above (2) was bonded to the outer surface of one protective film by a laminator, and then the pressure- For 7 days to obtain a polarizing plate with a pressure-sensitive adhesive layer.

The abbreviations in the "Protective film" column in Table 3 mean the following thermoplastic resins.

AC: (meth) acrylic resin (contact angle change ratio based on the above definition: 17.2%),

PE: polyester resin (contact angle change ratio based on the above definition: 14.7%),

CE: Cellulose resin (contact angle change rate based on the above definition: 21.7%).

(4) Evaluation of durability

The separator was peeled off from the polarizing plate with the pressure-sensitive adhesive layer prepared in (3), and the pressure-sensitive adhesive layer side thereof was adhered to both surfaces of a glass substrate for liquid crystal cell [Eagle XG manufactured by Corning Inc.] . Using these samples, the following three durability tests were carried out.

[Durability test]

· Heat resistance test in which temperature is maintained at 80 ℃ for 500 hours,

· Moisture resistance test in which the temperature is maintained for 500 hours in an environment of a temperature of 60 ° C and a relative humidity of 90%

Heat-resisting shock (HS) test in which one cycle is carried out by holding for 30 minutes under a drying condition at a temperature of 70 ° C and then for 30 minutes under a drying condition of a temperature of -40 ° C and repeating this for 200 cycles.

The samples after each test were visually observed and durability was evaluated according to the following evaluation criteria. The results are shown in Table 3.

A: There is no change in appearance such as peeling, peeling, and foaming,

B: Almost no change in appearance such as peeling, peeling, foaming,

C: A lot of appearance changes such as lifting, peeling,

D: Appearance changes such as peeling, peeling, foaming and the like are remarkably confirmed.

(5) Evaluation of adhesion between the protective film and the pressure-sensitive adhesive layer

A test piece having a width of 25 mm and a length of 150 mm was cut from the polarizer with a pressure-sensitive adhesive layer prepared in (3) above. Then, the separator was peeled from the test piece, and then fixed to an adhesion evaluation jig manufactured by Nippon System Group Co., Ltd. The following peeling test was carried out. The surface of the pressure-sensitive adhesive layer was rubbed with the rubber piece by inserting a test rubber piece (material: neoprene rubber, hardness: JIS A hardness 65) on the surface of the pressure-sensitive adhesive layer and making the rubber piece reciprocate 20 times on the test piece. The moving direction of the test piece and the width direction of the test piece were made parallel.

The surface of the test piece after the peeling test on the pressure-sensitive adhesive layer side was observed. In either of the examples and the comparative examples, the pressure-sensitive adhesive layer was peeled off on one end side in the width direction of the test piece after the peeling test, and a part of the pressure-sensitive adhesive layer remained on the other end side. The position of the remaining pressure-sensitive adhesive layer (the position in the longitudinal direction of the test piece) was determined, and the distance from the one end to the above-mentioned position was measured as the peeling distance. The results are shown in Table 3. When the peeling distance (curing period of 7 days) is 15 mm or less, adhesion between the protective film and the pressure-sensitive adhesive layer is good.

1: Polarizer 2: Surface treatment layer 3: 4: Protective film 7: Phase difference film 8: Interlayer adhesive 10: Polarizer 20: Pressure sensitive adhesive layer 25: Polarizer with adhesive layer 30: Glass substrate

Claims (11)

Wherein the content of the constituent unit derived from the (meth) acrylic monomer having a hydroxyl group is 0.2 to 4 wt%, the content of the constituent unit derived from a (meth) acrylic monomer having a carboxyl group is 0 to 4 wt% 100 parts by weight of a (meth) acrylic resin (A) having a temperature of 55 占 폚 or higher,
0.1 to 1 part by weight of an isocyanate-based crosslinking agent (B) having an isocyanate group bonded to carbon atoms constituting an aliphatic skeleton
By weight. The pressure-sensitive adhesive composition according to claim 1, wherein the isocyanate group is bonded to a carbon atom constituting a methylene group. The pressure-sensitive adhesive composition according to claim 1 or 2, wherein the content of the structural unit derived from the (meth) acrylic monomer having a hydroxyl group is 3.5% by weight or less. The pressure-sensitive adhesive composition according to claim 1 or 2, further comprising an ionic compound (C). The pressure-sensitive adhesive composition according to claim 1 or 2, further comprising a silane compound (D). A pressure-sensitive adhesive layer comprising the pressure-sensitive adhesive composition according to claim 1 or 2. An optical member with a pressure-sensitive adhesive layer comprising an optical member and the pressure-sensitive adhesive layer according to claim 6 laminated on the optical member. The optical member with a pressure-sensitive adhesive layer according to claim 7, wherein a surface of the optical member on which the pressure-sensitive adhesive layer is laminated has a contact angle change rate of not more than 40% when subjected to corona treatment. The optical element according to claim 8, wherein the optical member comprises a polarizer and a protective film laminated thereon,
Wherein the surface is a surface of the protective film. The optical member with a pressure-sensitive adhesive layer according to claim 8, wherein the surface is a corona-treated surface. The optical member with a pressure-sensitive adhesive layer according to claim 9, wherein the surface is a corona-treated surface.

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