KR101900982B1 - Optical film having adhesive agent, and optical laminated body in which same is used - Google Patents

Abstract

(A－2)는 방향환을 갖는 불포화 단량체,
(A－3)는 하기 식(Ⅱ) 화합물(R₃은 수소 또는 메틸; R₄는 알킬; m은 1~8),

(A－4)는 극성 관능기를 갖는 불포화 단량체이다.The present invention relates to a polyolefin composition comprising 80 to 96% by weight of (A-1), 1 to 15% by weight of (A-2), 0.1 to 5% by weight of (A- A pressure-sensitive adhesive layer obtained from a composition comprising 100 parts by weight of an acrylic copolymer as a copolymer of a monomer mixture and 0.3 to 12 parts by weight of an ionic compound and 0.1 to 5 parts by weight of a crosslinking agent in an optical film, A-1) is the following formula (I) compound (R ₁ is hydrogen or methyl; R ₂ is C _{1 -14} alkyl),

(A-2) is an unsaturated monomer having an aromatic ring,
(A-3) is a compound represented by the following formula (II) (R ₃ is hydrogen or methyl, R ₄ is alkyl, m is 1 to 8)

(A-4) is an unsaturated monomer having a polar functional group.

Description

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

The present invention relates to an optical film on which a pressure-sensitive adhesive layer is formed. Examples of the optical film to be used in the present invention include a polarizing plate and a retardation film. The present invention also relates to an optical laminate for liquid crystal display using the optical film on which the pressure-sensitive adhesive layer is formed.

The polarizer is mounted on a liquid crystal display device and widely used. The polarizing plate generally has a transparent protective film laminated on both sides of a polarizing film, and a pressure-sensitive adhesive layer is formed on the surface of at least one of the protective films, and the pressure-sensitive adhesive layer is spread on the pressure-sensitive adhesive layer. It is also known that a retardation film is laminated on a polarizing plate in which a protective film is adhered to both surfaces of a polarizing film to form an elliptically polarizing plate and the pressure-sensitive adhesive layer / release film is adhered to the retardation film in this order, A protective film is laminated on the other side, and a direct retardation film is laminated on the other side to form an elliptically polarizing plate, and the pressure-sensitive adhesive layer / release film is adhered to the retardation film side in this order. Further, the pressure-sensitive adhesive layer / release film may be adhered to the surface of the retardation film in this order. In the present specification, a polarizing plate, an elliptically polarizing plate, a retardation film, and the like provided with the pressure-sensitive adhesive layer are collectively referred to as an optical film. The release film is peeled off from the optical film provided with these pressure-sensitive adhesive layers before being bonded to the liquid crystal cell, and is bonded to the liquid crystal cell through the exposed pressure-sensitive adhesive layer. The optical film provided with such a pressure-sensitive adhesive layer is required to develop countermeasures because static electricity is generated when the release film is peeled off and bonded to the liquid crystal cell.

It has been proposed that an ionic compound of any kind is added to the pressure-sensitive adhesive composition to give antistatic properties to the pressure-sensitive adhesive layer formed next. For example, JP 2006-307238-A discloses blending an antistatic agent comprising an organic salt having an organic nitrogen onium cation and a bis (perfluoroalkanesulfonyl) imide anion in a pressure-sensitive adhesive (pressure-sensitive adhesive). JP 2004-114665-A discloses that a salt comprising a quaternary ammonium cation having a total carbon number of 4 to 20 and a fluorine atom-containing anion is contained in an adhesive or the like. JP 2006-307238-A discloses that an acrylic pressure-sensitive adhesive is blended with an ionic liquid which becomes a liquid at room temperature (25 ° C) to reduce the acid value to 1.0 or less. JP 2009-79205-A discloses the incorporation of an ionic compound having an organic cation at room temperature (25 캜) into an acrylic pressure-sensitive adhesive. JP 2010-66755-A discloses that an acrylic resin in which monomers having an aromatic ring are copolymerized is compounded with an ionic compound having an organic cation to obtain a pressure-sensitive adhesive.

It is also known to use an acrylic resin in which a (meth) acrylamide-based compound is copolymerized with an acrylic pressure-sensitive adhesive to be adhered to an optical film. For example, in JP 2007-264092-A, a crosslinking agent is blended in an acrylic copolymer having alkyl (meth) acrylate and N- (2-hydroxyethyl) (meth) acrylamide as monomer units, Discloses an optical pressure-sensitive adhesive which is less prone to display unevenness. JP 2009-126929-A discloses a process for producing an acrylic resin composition, which comprises blending an ionic compound in a copolymer polymer in which (meth) acrylamide having a hydroxyl group is copolymerized with (meth) acrylic acid ester, And a pressure-sensitive adhesive composition capable of forming a pressure-sensitive adhesive layer. JP 2009-215528-A also discloses a (meth) acrylic acid ester containing a (meth) acrylic acid ester, a (meth) acrylic acid ester having an aromatic ring and a (meth) acrylic acid ester having an amino group and having a carboxyl group and / An isocyanate-based crosslinking agent and a silane-based compound are blended with an acrylic resin having a weight average molecular weight ranging from 1.6 to 3 million, which is obtained from the monomer mixture containing the acrylic resin, to suppress the light leakage caused by the stress accompanying the dimensional change of the optical film and the like Sensitive adhesive composition for an optical film that can satisfy the reworkability and processability, and an example in which N, N-dimethylaminopropylacrylamide is used instead of the (meth) acrylic acid ester having an amino group is also disclosed .

On the other hand, the above-mentioned optical film with a pressure-sensitive adhesive layer is applied to a liquid crystal cell on the pressure-sensitive adhesive layer side to form a liquid crystal display device. However, when the optical film is placed under high temperature or high temperature and high humidity conditions, There is a possibility that foaming occurs in the pressure-sensitive adhesive layer accompanied with dimensional change or peeling or peeling occurs between the optical film and the pressure-sensitive adhesive layer or between the pressure-sensitive adhesive layer and the liquid-crystal cell glass, It is also required to have excellent durability.

The high-temperature condition at which the liquid crystal display device is exposed differs depending on the use of the liquid crystal display device. The optical film with a pressure-sensitive adhesive containing the ionic compound as an antistatic agent may exhibit sufficient durability in a test in a general temperature range assumed for a television or a monitor, and may be a test under a harsh environment There was a case where peeling or peeling occurred between the pressure-sensitive adhesive layer and the liquid crystal cell glass. Particularly, when the optical film to which the pressure-sensitive adhesive layer is bonded has low moisture permeability, this tendency is remarkable.

An object of the present invention is to provide a pressure sensitive adhesive layer excellent in durability in which peeling does not occur even in a test under a harsh environment in which antistatic properties are imparted when bonding to glass, Film, and laminating it on a glass substrate to obtain an optical laminate excellent in durability. The present inventors have conducted intensive studies to solve these problems. As a result, they have found that (meth) acrylic acid ester is a main component and unsaturated monomers having an aromatic ring in a molecule, an N-alkoxyalkyl (meth) acrylamide and a polar functional group It has been found that it is effective to form a pressure-sensitive adhesive composition by mixing an acrylic resin obtained by copolymerizing at least four components of monomers with an ionic compound and a crosslinking agent, and to provide this composition as a pressure-sensitive adhesive layer on the surface of the optical film.

That is, the present invention includes the following.

[1] A pressure-sensitive adhesive optical film comprising an optical film and a pressure-sensitive adhesive layer formed on at least one side of the pressure-sensitive adhesive layer, wherein the pressure-sensitive adhesive layer comprises 100 parts by weight of the acrylic copolymer (A), 0.3 to 12 parts by weight of an ionic compound B) and 0.1 to 5 parts by weight of a cross-linking agent (C)

The acrylic copolymer (A) contains 80 to 96% by weight of (A-1), 1 to 15% by weight of (A-2), 0.1 to 5% by weight of (A-3) Of a monomer mixture comprising (A-4)

(A-1) is represented by the following formula (I)

(Wherein R ₁ is a hydrogen atom or a methyl group and R ₂ is an alkyl group having 1 to 14 carbon atoms which may be substituted with an alkoxy group having 1 to 10 carbon atoms)

(A-2) is an unsaturated monomer having one olefinic double bond and at least one aromatic ring in the molecule,

(A-3) is represented by the following formula (II)

(Meth) acrylamide represented by the following formula ( ₃ ): wherein R ₃ represents a hydrogen atom or a methyl group, R ₄ represents an alkyl group, and m represents an integer of 1 to 8,

(A-4) is an unsaturated monomer having a polar functional group.

[2] The adhesive film-attached optical film according to [1], wherein the unsaturated monomer (A-2) having an aromatic ring is a phenoxyethyl group-containing (meth) acrylic compound represented by the following formula (III).

In the formula, R ₅ represents a hydrogen atom or a methyl group, n represents an integer of 1 to 8, and R ₆ represents a hydrogen atom, an alkyl group, an aralkyl group or an aryl group.

[3] In the formula (II) representing the N-alkoxyalkyl (meth) acrylamide (A-3), R ₄ is an alkyl group having 1 to 6 carbon atoms and m is an integer of 1 to 4. 2].

[4] The N-alkoxyalkyl (meth) acrylamide (A-3)

N- (methoxymethyl) acrylamide,

N- (ethoxymethyl) acrylamide,

N- (propoxymethyl) acrylamide,

N- (1-methylethoxymethyl) acrylamide,

N- (1-methylpropoxymethyl) acrylamide,

N- (2-methylpropoxymethyl) acrylamide,

N- (butoxymethyl) acrylamide,

N- (1,1-dimethylethoxymethyl) acrylamide,

N- (2-methoxyethyl) acrylamide,

N- (2-ethoxyethyl) acrylamide,

N- (2-propoxyethyl) acrylamide,

N- [2- (1-methylethoxy) ethyl] acrylamide,

N- [2- (1-methylpropoxy) ethyl] acrylamide,

N- [2- (2-methylpropoxy) ethyl] acrylamide,

N- (2-butoxyethyl) acrylamide, or

Acrylate, and N- [2- (1,1-dimethylethoxy) ethyl] acrylamide.

[5] The pressure-sensitive adhesive composition according to any one of [1] to [4], wherein the unsaturated monomer (A-4) having a polar functional group has a polar functional group selected from the group consisting of free carboxyl groups, hydroxyl groups, amino groups, film.

[6] The optical film with a pressure-sensitive adhesive according to any one of [1] to [5], wherein the cross-linking agent (C) contains an isocyanate-based compound.

[7] The pressure-sensitive adhesive composition according to any one of [1] to [6], wherein the pressure-sensitive adhesive composition further contains 0.03 to 2 parts by weight of the silane compound (D) based on 100 parts by weight of the acrylic copolymer (A) .

[8] The optical film with a pressure-sensitive adhesive according to any one of [1] to [7], wherein the optical film is selected from the group consisting of a polarizing plate and a retardation film.

[9] The optical film with a pressure-sensitive adhesive according to any one of [1] to [8], wherein the release film is adhered to the surface of the pressure-sensitive adhesive layer.

[10] The optical film with a pressure-sensitive adhesive according to any one of [1] to [8], which is laminated on a glass substrate and a glass substrate on the pressure-sensitive adhesive layer side.

The optical film with a pressure-sensitive adhesive of the present invention can effectively suppress the charging of the optical member to which the pressure-sensitive adhesive is adhered, and the pressure-sensitive adhesive layer is placed under high temperature or high temperature and high humidity conditions in a state where the pressure- Durability is excellent. Further, even if the optical film with the adhesive is peeled off from the glass substrate together with the adhesive after the optical film with the adhesive is once laminated on the glass substrate, residual adhesive or haze may occur on the surface of the glass substrate after peeling And can be used again as a glass substrate, resulting in excellent reworkability.

Hereinafter, the present invention will be described in detail. In the optical film with a pressure-sensitive adhesive of the present invention, a pressure-sensitive adhesive layer is formed on at least one surface of the optical film, and the pressure-sensitive adhesive layer is formed of a composition containing the following components (A) to (C).

(A) an unsaturated monomer having a structural unit derived from the (meth) acrylic acid ester (A-1) represented by the above formula (I) as a main component and having one olefinic double bond and at least one aromatic ring in the molecule (A-2), a structural unit derived from the N-alkoxyalkyl (meth) acrylamide (A-3) represented by the formula (II) and an unsaturated monomer having a polar functional group An acrylic copolymer containing a predetermined amount of derived structural units,

(B) an ionic compound having an organic cation, and

(C) a crosslinking agent.

First, each component constituting the pressure-sensitive adhesive composition used for forming the pressure-sensitive adhesive layer will be described.

[Acrylic copolymer (A)]

In the pressure-sensitive adhesive optical film of the present invention, the acrylic copolymer (A) constituting the pressure-sensitive adhesive composition used for forming the pressure-sensitive adhesive layer has a structure derived from the (meth) acrylic acid ester (A-1) (A-2) having one olefinic double bond and at least one aromatic ring in the molecule in addition to the structural unit derived from the (meth) acrylic acid ester (A-1) A structural unit derived from an N-alkoxyalkyl (meth) acrylamide (A-3) represented by the formula (II) and an unsaturated monomer having a polar functional group (A-4) . The term "(meth) acrylic acid" means any acrylic acid or methacrylic acid, and "(meth) acrylamide" means any of acrylamide and methacrylamide. Quot; (meta) " when the term " (meth) acryloyl "

In the formula (I), which is a main structural unit of the acrylic copolymer (A), R ₁ is a hydrogen atom or a methyl group, and R ₂ is an alkyl group having 1 to 14 carbon atoms. The alkyl group represented by R ₂ may be substituted with an alkoxy group having 1 to 10 carbon atoms. In this case, the alkoxy group substitutes the hydrogen atom constituting the alkyl group.

Specific examples of the (meth) acrylic acid ester (A-1) represented by the formula (I) include linear acrylic acid such as methyl acrylate, ethyl acrylate, propyl acrylate, n-butyl acrylate, n-octyl acrylate, Alkyl esters; Branched acrylic acid alkyl esters such as isobutyl acrylate, 2-ethylhexyl acrylate, and isooctyl acrylate; Linear methyl methacrylate alkyl esters such as methyl methacrylate, ethyl methacrylate, propyl methacrylate, n-butyl methacrylate, n-octyl methacrylate, and lauryl methacrylate; Methacrylic acid alkyl esters such as isobutyl methacrylate, 2-ethylhexyl methacrylate, and iso-octyl methacrylate are exemplified.

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, specifically include 2-methoxyethyl acrylate, ethoxymethyl acrylate, 2-methoxyethyl methacrylate, 2-methoxyethyl methacrylate, 2-methoxyethyl methacrylate, 2-methoxyethyl acrylate and ethoxymethyl methacrylate.

These (meth) acrylic acid esters may be used alone or in combination using a plurality of different (meth) acrylic acid esters.

The unsaturated monomer (A-2) having one olefinic double bond and at least one aromatic ring in the molecule preferably has a (meth) acryloyl group as a group containing an olefinic double bond. Such unsaturated monomers include benzyl (meth) acrylate, neopentyl glycol benzoate (meth) acrylate and the like, but a phenoxyethyl group-containing (meth) acrylic compound represented by the formula (III) is particularly preferable.

In the formula (III) representing the phenoxyethyl group-containing (meth) acrylic compound, R ₅ is a hydrogen atom or a methyl group, n is an integer of 1 to 8, and R ₆ is a hydrogen atom, an alkyl group, . When R ₆ in the formula (III) is an alkyl group, the number of carbon atoms thereof may be about 1 to 9, and when it is an aralkyl group, the number of carbon atoms thereof is about 7 to 11, and when it is an aryl group, .

Specific examples of the (meth) acrylic compound represented by the formula (III) include 2-phenoxyethyl (meth) acrylate, 2- (2-phenoxyethoxy) ethyl (meth) acrylate, ) Acrylate, and 2- (o-phenylphenoxy) ethyl (meth) acrylate. The unsaturated monomer (A-2) having one olefinic double bond and at least one aromatic ring in these molecules may be used alone or in combination of two or more. Particularly preferred among these compounds are 2-phenoxyethyl (meth) acrylate [compounds of the formula (III) in which R ₆ = H and n = 1) or 2- (2-phenoxyethoxy) ethyl to use in the formula (ⅲ), as one of the R ₆ = H, the compound of n = 2] the unsaturated monomer having an aromatic ring constituting the acrylic copolymer (a) (a-2) is preferred.

R ₃ is a hydrogen atom or a methyl group, R ₄ is an alkyl group, and m is an integer of 1 to 8, in the formula (II) representing an N-alkoxyalkyl (meth) acrylamide (A- The alkyl group represented by R ₄ may have about 1 to 9 carbon atoms, but usually about 1 to 6 carbon atoms is sufficient. And m is preferably in the range of 1 to 4.

As for the N-alkoxyalkyl (meth) acrylamide, acrylic amide is taken as an example, and typical representative compounds thereof are as follows.

N- (methoxymethyl) acrylamide,

N- (ethoxymethyl) acrylamide,

N- (propoxymethyl) acrylamide,

N- (1-methylethoxymethyl) acrylamide,

N- (1-methylpropoxymethyl) acrylamide,

N- (2-methylpropoxymethyl) acrylamide (also referred to as N- (isobutoxymethyl) acrylamide], N-

N- (butoxymethyl) acrylamide,

N- (1,1-dimethylethoxymethyl) acrylamide,

N- (2-methoxyethyl) acrylamide,

N- (2-ethoxyethyl) acrylamide,

N- (2-propoxyethyl) acrylamide,

N- [2- (1-methylethoxy) ethyl] acrylamide,

N- [2- (1-methylpropoxy) ethyl] acrylamide,

N- [2- (2-methylpropoxy) ethyl] acrylamide [alias N- (2-isobutoxyethyl) acrylamide]

N- (2-butoxyethyl) acrylamide,

N- [2- (1,1-dimethylethoxy) ethyl] acrylamide, and the like.

Of course, the compound that converts these acrylamides to methacrylamides may also be N-alkoxyalkyl (meth) acrylamide (A-3). These N-alkoxyalkyl (meth) acrylamides may also be used singly or in combination of two or more species of compounds corresponding to Formula (II). Particularly preferred among them are N- (methoxymethyl) acrylamide, N- (ethoxymethyl) acrylamide, N- (propoxymethyl) acrylamide, N- (butoxymethyl) Methylpropoxymethyl) acrylamide is preferably used.

The N-alkoxyalkyl (meth) acrylamide represented by the formula (II) is obtained by forming an acrylic copolymer (A) copolymerized at a predetermined ratio thereof as a main component and constituting the pressure-sensitive adhesive composition, and an optical film provided with a pressure- And is effective for enhancing durability when exposed to a high temperature, particularly at a high temperature of about 100 캜. The N-alkoxyalkyl (meth) acrylamide has such a structure that it does not have a tertiary amino group in order to avoid strong adhesion between the pressure-sensitive adhesive layer and any kind of peeling film.

The unsaturated monomer (A-4) having a polar functional group is used for reacting with the crosslinking agent (C) to be described later to form a crosslinked structure in the pressure-sensitive adhesive layer to develop a cohesive force. Examples thereof include monomers having a free carboxyl group such as acrylic acid, methacrylic acid and 2-carboxyethyl acrylate; Acrylate such as 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2- or 3-chloro-2-hydroxypropyl (meth) acrylate, and diethylene glycol mono ; (Meth) acrylate, caprolactone-modified tetrahydrofurfuryl acrylate, 3,4-epoxycyclohexylmethyl (meth) acrylate, and the like. ) Acrylate, glycidyl (meth) acrylate, and 2,5-dihydrofuran; N, N-dimethylaminoethyl (meth) acrylate, and the like.

Each of these monomers having a polar functional group may be used alone or in combination of two or more.

Among them, it is preferable to use a monomer having a hydroxyl group as one of the unsaturated monomers (A-4) having a polar functional group constituting the acrylic copolymer (A). It is also effective to use, in addition to the monomer having a hydroxyl group, a monomer having another polar functional group, for example, a monomer having a free carboxyl group.

The acrylic copolymer (A) used for forming the pressure-sensitive adhesive layer contains 80 to 96% by weight of the (meth) acrylate ester (A-1) represented by the formula (I), one olefinic double bond and at least one 1 to 15% by weight of an unsaturated monomer having an aromatic ring (A-2), 0.1 to 5% by weight of an N-alkoxyalkyl (meth) acrylamide (A-3) represented by the formula (II) (A-4) in a proportion of 0.5 to 5% by weight based on the total weight of the copolymer. An optical film having a pressure-sensitive adhesive layer formed from a pressure-sensitive adhesive composition containing the acrylic copolymer (A) as a main component by copolymerizing at least four components at a predetermined ratio has resistance to moisture and humidity, durability at a temperature of around 80 캜, Durability at a high temperature of about 100 캜 can be increased. The preferred copolymerization ratio of the (meth) acrylic acid ester (A-1) is 82 to 92% by weight. The unsaturated monomer (A-2) having an aromatic ring preferably has a copolymerization ratio of 3 to 15% by weight, more preferably 7 to 12% by weight. The preferred copolymerization ratio of the N-alkoxyalkyl (meth) acrylamide (A-3) is 0.1 to 2% by weight, further 0.1 to 1% by weight. The unsaturated monomer (A-4) having a polar functional group preferably has a copolymerization ratio of 0.5 to 3% by weight. Of course, in the monomer mixture to be the raw material of the acrylic copolymer (A), the (meth) acrylate ester (A-1), the unsaturated monomer having an aromatic ring (A-2), the N-alkoxyalkyl -3) and the unsaturated monomer (A-4) having a polar functional group is not more than 100% by weight.

The acrylic copolymer (A) used in the present invention is a copolymer of the above-mentioned (meth) acrylic acid ester (A-1), an unsaturated monomer having an aromatic ring (A-2), N-alkoxyalkyl (meth) ), And a monomer unit other than the unsaturated monomer (A-4) having a polar functional group. Examples thereof include a structural unit derived from a (meth) acrylic acid ester having an alicyclic structure in the molecule, a structural unit derived from a styrene-based monomer, a structural unit derived from a vinyl-based monomer, a plurality of (meth) acryloyl groups in the molecule And a structural unit derived from a monomer having a carboxyl group.

(Meth) acrylic acid ester having an alicyclic structure will be described. The alicyclic structure is a cycloparaffin structure having a carbon number of usually 5 or more, preferably 5 to 7 or so. Specific examples of the acrylic ester having an alicyclic structure include isobornyl acrylate, cyclohexyl acrylate, dicyclopentanyl acrylate, cyclododecyl acrylate, methylcyclohexyl acrylate, trimethylcyclohexyl acrylate, tert-butylcyclohexyl acrylate, Cyclohexyl methoxyacrylate, cyclohexylphenyl acrylate, and the like. Specific examples of the methacrylic ester having an alicyclic structure include isobornyl methacrylate, cyclohexyl methacrylate, dicyclopentanyl methacrylate, cyclododecyl methacrylate, methylcyclohexyl methacrylate, methacrylate Trimethylcyclohexyl acrylate, tert-butylcyclohexyl methacrylate, cyclohexylphenyl methacrylate, and the like.

Examples of the styrene-based monomer include alkyl styrenes such as styrene, methylstyrene, dimethylstyrene, trimethylstyrene, ethylstyrene, diethylstyrene, triethylstyrene, propylstyrene, butylstyrene, hexylstyrene, heptylstyrene and octylstyrene; Halogenated styrenes such as fluorostyrene, chlorostyrene, bromostyrene, dibromostyrene and iodostyrene; Also, there are nitrostyrene, acetylstyrene, methoxystyrene, divinylbenzene, and the like.

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

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

The monomers other than (A-1) to (A-4) may be used alone or in combination of two or more. When the monomers other than (A-1) to (A-4) are copolymerized in the acrylic copolymer (A), the amount thereof is usually 20% by weight or less based on the total monomers constituting the acrylic copolymer (A) Preferably not more than 10% by weight.

The acrylic copolymer constituting the pressure-sensitive adhesive composition includes the (meth) acrylic acid ester (A-1) represented by the formula (I) described above, the unsaturated monomer (A-1) having one olefinic double bond and at least one aromatic ring in the molecule, Acrylic copolymer having a structural unit derived from an N-alkoxyalkyl (meth) acrylamide (A-3) represented by the formula (II) and an unsaturated monomer having a polar functional group A) may be a mixture of two or more. The acrylic copolymer (A) obtained by copolymerizing the monomers (A-1) to (A-4) at a predetermined ratio may be mixed with an acrylic resin different from the acrylic copolymer. The different acrylic resins to be mixed in this case may be, for example, those having a structural unit derived from the (meth) acrylic acid ester of the above formula (I) and having no polar functional group. The acrylic copolymer containing the structural units derived from (A-1) to (A-4) is an acrylic copolymer containing a structural unit derived from (A-1) to (A-4) Acrylic resin is preferably 80% by weight or more, more preferably 90% by weight or more.

(A-2), an N-alkoxyalkyl (meth) acrylamide (A-3) and an unsaturated monomer (A-4) having a polar functional group, (A), which is a copolymer obtained from a monomer mixture containing a monomer having a weight average molecular weight Mw in terms of standard polystyrene by gel permeation chromatography (GPC), is preferably in the range of 500,000 to 2,000,000. If the weight average molecular weight is too small, there is a tendency that the adhesiveness under high temperature and high humidity is lowered, or the possibility that peeling or peeling occurs between the glass substrate and the pressure-sensitive adhesive layer is increased or the reworkability is lowered. The lower limit is 50,000. If the weight average molecular weight of the liquid crystal cell is less than 2,000,000, even if the size of the optical film adhered to the pressure-sensitive adhesive layer using the pressure-sensitive adhesive layer is changed, the pressure- So that there is a tendency that white voids and unevenness are suppressed.

The preferred weight average molecular weight of the acrylic copolymer (A) also varies depending on the material of the pressure-sensitive adhesive layer-formed surface of the optical film on which the pressure-sensitive adhesive layer using this resin is formed. Conventionally, it has been considered that the weight average molecular weight of the acrylic resin constituting the acrylic pressure-sensitive adhesive is at least about 1 million. In contrast, in the acrylic copolymer (A) copolymerized with the N-alkoxyalkyl (meth) acrylamide (A-3) according to the present invention, the pressure-sensitive adhesive layer- ℃, is generally film having a greater water vapor transmission rate than 300g / (m ² · 24hr) at a relative humidity of 90%, when the weight average molecular weight of the acrylic copolymer (a) to form a pressure-sensitive adhesive layer is relatively small at about 50 ~ 100 man , Sufficient results are given. When such a resin film having a large moisture permeability is used as the pressure-sensitive adhesive layer-formed surface, the weight average molecular weight of the acrylic copolymer (A) may be a large value within a range of not more than 2,000,000. The moisture permeability will be described later in the section "Optical film with adhesive". As a typical optical film in which a resin film exhibiting a relatively high moisture permeability serves as a pressure-sensitive adhesive layer-forming surface, a polarizing plate in which a protective film made of an acetylcellulose resin or a retardation film is stuck on one surface of a polarizing film made of a polyvinyl alcohol- . In this case, the surface of the acetylcellulose-based resin film becomes a pressure-sensitive adhesive layer-forming surface, and a protective film made of an acetylcellulose-based resin may be applied to the surface of the polarizing film opposite to the surface to which the acetylcellulose- Other protective films may be laminated.

On the other hand, when the pressure-sensitive adhesive layer-forming side of the optical film is a polyolefin film or a cycloolefin-based resin film itself or a retardation film obtained by uniaxially or biaxially stretching them at a temperature of 40 DEG C and a relative humidity of 90% m ² · 24 hr) or less, when the weight average molecular weight of the acrylic resin forming the pressure-sensitive adhesive layer is small, when the pressure-sensitive adhesive layer is attached to the glass substrate, There is a tendency that peeling is likely to occur. In this case, the weight average molecular weight of the acrylic copolymer (A) is preferably 1 million or more. From the viewpoint of enhancing adhesion under high temperature and high humidity, it is preferable that the weight average molecular weight of the acrylic copolymer (A) is at least 1,000,000. As a typical optical film in which such a resin film exhibiting a relatively low moisture permeability serves as a pressure-sensitive adhesive layer-forming surface, a polyolefin film or a cycloolefin-based resin film is uniaxially stretched or stretched on one side of a polarizing film made of a polyvinyl alcohol- And a polarizing plate to which a retardation film obtained by axial stretching is bonded. In this case, the retardation film surface serves as the pressure-sensitive adhesive layer formation surface, and an arbitrary protective film can be bonded to the polarizing film surface opposite to the surface to which the retardation film is adhered.

The molecular weight distribution represented by the ratio Mw / Mn of the weight average molecular weight Mw to the number average molecular weight Mn of the acrylic copolymer (A) is usually in the range of about 3 to 7.

The acrylic copolymer (A) constituting the pressure-sensitive adhesive composition can be produced by various known methods such as a solution polymerization method, an emulsion polymerization method, a bulk polymerization method and a suspension polymerization method. In the production of the acrylic copolymer, a polymerization initiator is usually 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 acrylic copolymer.

As the polymerization initiator, a thermal polymerization initiator, a photopolymerization initiator, and the like are used. As the photopolymerization initiator, for example, 4- (2-hydroxyethoxy) phenyl (2-hydroxy-2-propyl) ketone and the like can be given. As the thermal polymerization initiator, for example, 2,2'-azobisisobutylonitrile, 2,2'-azobis (2-methylbutyronitrile), 1,1'-azobis (cyclohexane- (2,2'-azobis (2,4-dimethyl-4-methoxy valeronitrile), dimethyl-2,2 ' Azo-based 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, tert-butyl peroxyneodecanoate , tert-butyl peroxypivalate, and (3,5,5-trimethylhexanoyl) peroxide; And inorganic peroxides such as potassium persulfate, ammonium persulfate, and hydrogen peroxide. A redox-based initiator using a peroxide and a reducing agent in combination may also be used as a polymerization initiator.

As a method of producing an acrylic copolymer, a solution polymerization method is preferable among the above-mentioned methods.

A specific example of the solution polymerization method is described below. A desired monomer and an organic solvent are mixed, and a thermal polymerization initiator is added under a nitrogen atmosphere. The solution is heated at a temperature of about 40 to 90 DEG C, preferably about 60 to 80 DEG C for 3 to 10 hours Followed by stirring. In order to control the reaction, a monomer or a thermal polymerization initiator may be added continuously or intermittently during the polymerization or 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.

[Ionic Compound (B)]

The ionic compound (B) is added in order to impart conductivity to the pressure-sensitive adhesive layer and to enhance antistatic properties of the optical film. The cation component constituting the ionic compound (B) is not particularly limited as long as it is an organic cation. For example, a pyridinium cation, an imidazolium cation, a pyrrolidinium cation, an ammonium cation, a sulfonium cation, a phosphonium cation and the like, but when used in a pressure sensitive adhesive layer of an optical film, From the viewpoint that it is difficult to be charged when peeling, a pyridinium cation or an imidazolium cation is preferable.

On the other hand, in the ionic compound (B), the anion component serving as a counter ion of the cation component is not particularly limited and may be an inorganic anion or an organic anion. For example, .

Chloride anion [Cl ^- ],

Bromide anion [Br ^- ],

Iodide anion [I ^- ],

Tetrachloroaluminate anion [AlCl ₄ ^- ],

Heptachlorodialuminate anion [Al ₂ Cl ₇ ^- ],

Tetrafluoroborate anion [BF ₄ ^- ],

Hexafluorophosphate anion [PF ₆ ^- ],

Perchlorate anion [ClO ₄ ^- ],

Nitrate anion [NO ₃ ^- ],

Acetate anion [CH ₃ COO ^- ],

Trifluoroacetate anion [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 ^- ],

Bis (fluorosulfonyl) imide anion [(FSO ₂ ) ₂ N ^- ],

Bis (trifluoromethanesulfonyl) imide anion [(CF ₃ SO ₂ ) ₂ N ^- ],

Tris (trifluoromethanesulfonyl) methanide anion [(CF ₃ SO ₂ ) ₃ C ^- ],

Hexafluoroacetate anion [AsF ₆ ^- ],

Hexafluoroantimonate anion [SbF ₆ ^- ],

Hexafluoroniobate anion [NbF ₆ ^- ],

Hexafluorotantalate anion [TaF ₆ ^- ],

Dimethylphosphinate anion [(CH ₃ ) ₂ POO ^- ],

(Poly) hydrofluorofluoride anion [F (HF) _n ^- ] (n is about 1 to 3),

Dicyanamid anion [(CN) ₂ N ^- ],

Thiocyan anion [SCN ^- ],

Perfluorobutanesulfonate 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 ^- ],

(Trifluoromethanesulfonyl) (trifluoromethanecarbonyl) imide anion [(CF ₃ SO ₂ ) (CF ₃ CO) N ^- ] and the like.

Among them, an anion component containing a fluorine atom is preferably used in terms of imparting an ionic compound excellent in antistatic property, and in particular, a bis (fluorosulfonyl) imide anion, a hexafluorophosphate anion, (Trifluoromethanesulfonyl) imide anion is preferable.

Specific examples of the ionic compound used in the present invention may be appropriately selected from a combination of the cationic component and the anionic component. Specific examples of the compound that is a combination of a cation component and an anion component include the following.

Pyridinium salts:

N-hexylpyridinium hexafluorophosphate,

N-octylpyridinium hexafluorophosphate,

N-methyl-4-hexylpyridinium hexafluorophosphate,

N-butyl-4-methylpyridinium hexafluorophosphate,

N-octyl-4-methylpyridinium hexafluorophosphate,

N-hexylpyridinium bis (fluorosulfonyl) imide,

N-octylpyridinium bis (fluorosulfonyl) imide,

N-methyl-4-hexylpyridinium bis (fluorosulfonyl) imide,

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

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

N-hexylpyridinium bis (trifluoromethanesulfonyl) imide,

N-octylpyridinium bis (trifluoromethanesulfonyl) imide,

N-methyl-4-hexylpyridinium bis (trifluoromethanesulfonyl) imide,

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

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

N-hexylpyridinium p-toluenesulfonate,

N-octylpyridinium p-toluenesulfonate,

N-methyl-4-hexylpyridinium p-toluenesulfonate,

N-butyl-4-methylpyridinium p-toluenesulfonate,

N-octyl-4-methylpyridinium p-toluenesulfonate and the like.

Imidazolium salts:

1-ethyl-3-methylimidazolium hexafluorophosphate,

Ethyl-3-methylimidazolium bis (fluorosulfonyl) imide,

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

1-ethyl-3-methylimidazolium p-toluenesulfonate,

1-butyl-3-methylimidazolium methanesulfonate and the like.

Pyrrolidinium salts:

N-butyl-N-methylpyrrolidinium hexafluorophosphate,

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

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

N-butyl-N-methylpyrrolidinium p-toluenesulfonate and the like.

· Ammonium salt:

Tetrabutylammonium hexafluorophosphate, tetrabutylammonium hexafluorophosphate,

Tetrabutylammonium bis (fluorosulfonyl) imide,

Tetrahexylammonium bis (fluorosulfonyl) imide,

Trioctylmethylammonium bis (fluorosulfonyl) imide,

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

Tetrabutylammonium bis (trifluoromethanesulfonyl) imide,

Tetrahexylammonium bis (trifluoromethanesulfonyl) imide,

Trioctylmethylammonium bis (trifluoromethanesulfonyl) imide,

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

Tetrabutylammonium p-toluene sulfonate,

Tetrahexylammonium p-toluenesulfonate,

Trioctylmethylammonium p-toluenesulfonate,

(2-hydroxyethyl) trimethylammonium p-toluenesulfonate,

(2-hydroxyethyl) trimethylammonium dimethylphosphinate and the like.

These ionic compounds (B) may be used alone or in combination of two or more. The examples of the ionic compound (B) are, of course, not limited to those exemplified above.

As described above, the ionic compound (B) is effective for imparting antistatic properties to the pressure-sensitive adhesive layer formed of the pressure-sensitive adhesive composition containing the acrylic copolymer (A) and maintaining various physical properties as a pressure-sensitive adhesive. Particularly, from the viewpoint of long-term stability of antistatic property, the ionic compound (B) is solid at room temperature (25 ° C), specifically, at 30 ° C Deg.] C or more, and more preferably 35 [deg.] C or more. On the other hand, if the melting point is too high, compatibility with the acrylic copolymer (A) is deteriorated. Therefore, it is preferable that the melting point is not higher than 80 캜 and not higher than 70 캜.

The ionic compound (B) is compounded in a proportion of 0.3 to 12 parts by weight based on 100 parts by weight of the acrylic copolymer (A). It is preferable that 0.3 parts by weight or more of the ionic compound (B) is added to 100 parts by weight of the acrylic copolymer (A) because the antistatic property is improved. When the amount is 12 parts by weight or less, durability It is preferable in that it is easy to carry out. The amount of the ionic compound (B) relative to 100 parts by weight of the acrylic copolymer (A) is preferably 0.5 parts by weight or more and 3 parts by weight or less.

[Crosslinking agent (C)]

In addition to the acrylic copolymer (A) and the ionic compound (B) described above, a crosslinking agent (C) is blended to obtain a pressure-sensitive adhesive composition. The crosslinking agent (C) is a compound having at least two functional groups capable of crosslinking in a structural unit derived from an unsaturated monomer (A-4) having a particularly polar functional group in the acrylic copolymer (A), specifically, an isocyanate- Compounds, epoxy compounds, metal chelate compounds, and aziridine compounds.

The isocyanate compound is a compound having at least two isocyanate groups (-NCO) in the molecule and includes, for example, tolylene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, xylylene diisocyanate, Silylene diisocyanate, diphenylmethane diisocyanate, hydrogenated diphenylmethane diisocyanate, naphthalene diisocyanate, triphenylmethane triisocyanate, and the like. An adduct in which an isocyanate compound is reacted with a polyol such as glycerol or trimethylolpropane, or an isocyanate compound in the form of a dimer, a trimer or the like may be a crosslinking agent used in a pressure-sensitive adhesive. Two or more isocyanate compounds may be mixed and used.

The epoxy compound is a compound having at least two epoxy groups in the molecule, and examples thereof include bisphenol A type epoxy resins, ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, glycerin diglycidyl ether, glycerin triglyceride N, N, N ', N'-tetraglycidyl ether, 1,6-hexanediol diglycidyl ether, trimethylol propane triglycidyl ether, N, N-diglycidyl aniline, m-xylylenediamine, and 1,3-bis (N, N'-diglycidylaminomethyl) cyclohexane. Two or more kinds of epoxy compounds may be mixed and used.

Examples of the metal chelate compound include compounds in which acetylacetone or ethyl acetoacetate is coordinated to a polyvalent metal such as aluminum, iron, copper, zinc, tin, titanium, nickel, antimony, magnesium, vanadium, chromium and zirconium .

The aziridine compound is a compound having at least two skeletons of a three-membered ring composed of one nitrogen atom and two carbon atoms, which is also called ethyleneimine, in the molecule, and examples thereof include diphenylmethane-4,4'-bis (1-aziridine Carboxamide), toluene-2,4-bis (1-aziridine carboxamide), triethylene melamine, isophthaloyl bis-1- (2-methyl aziridine), tris- Oxides, hexamethylene-1,6-bis (1-aziridine carboxamide), trimethylolpropane tris-? -Aziridinylpropionate, tetramethylolmethane tris-? -Aziridinylpropionate and the like .

Of these cross-linking agents, isocyanate compounds, particularly xylylene diisocyanate, tolylene diisocyanate or hexamethylene diisocyanate, or adducts in which these isocyanate compounds are reacted with polyols such as glycerol and trimethylolpropane, A dimer, a trimer or the like, a mixture of these isocyanate compounds, and the like are preferably used.

Preferred isocyanate compounds include tolylene diisocyanate, an adduct obtained by reacting tolylene diisocyanate with a polyol, a dimer of tolylene diisocyanate, a trimer of tolylene diisocyanate, hexamethylene diisocyanate, hexamethylene diisocyanate, An adduct obtained by reacting an isocyanate with a polyol, a dimer of hexamethylene diisocyanate, and a trimer of hexamethylene diisocyanate.

The crosslinking agent (C) is blended in a proportion of 0.1 to 5 parts by weight based on 100 parts by weight of the acrylic copolymer (A). The preferable amount is about 0.2 to 3 parts by weight based on 100 parts by weight of the acrylic copolymer (A). When the blending amount of the crosslinking agent (C) relative to 100 parts by weight of the acrylic copolymer (A) is 0.1 part by weight or more, the durability of the pressure-sensitive adhesive layer tends to be improved, and if it is 5 parts by weight or less, Is applied to a liquid crystal display device, white voids are not conspicuous.

[Other components constituting the pressure-sensitive adhesive]

The pressure sensitive adhesive for forming the pressure sensitive adhesive layer in the present invention preferably contains the silane compound (D) in order to improve the adhesion between the pressure sensitive adhesive layer and the glass substrate. Particularly, it is preferable that the acrylic copolymer It is preferable to contain the silane compound (D).

The silane compound is a compound having a hydrolyzable group such as an alkoxy group bonded to a silicon atom and an organic group having a reactive functional group such as a vinyl group, an amino group, an epoxy group, a haloalkyl group, a (meth) acryloyl group or a mercapto group . Examples of the respective specific compounds include vinyltrimethoxysilane, vinyltriethoxysilane, vinyltris (2-methoxyethoxy) silane, and the like. Examples of the silane compound having an amino group include N- (2-aminoethyl) -3-aminopropylmethyldimethoxysilane, N- (2-aminoethyl) -3-aminopropyltrimethoxysilane, And silane. Examples of the silane compound having an epoxy group include 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-glycidoxypropyldimethoxymethylsilane, 3-glycidoxypropylethoxydimethylsilane , 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, and the like. Examples of the silane compound having a haloalkyl group include 3-chloropropylmethyldimethoxysilane, 3-chloropropyltrimethoxysilane, and the like. Examples of the silane compound having a (meth) acryloyl group include 3- (meth) acryloyloxypropyltrimethoxysilane and the like. The silane compound having a mercapto group includes 3-mercaptopropyltrimethoxysilane and the like. Two or more silane compounds (D) may be used in combination.

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

3-mercaptopropyltrimethoxysilane-tetramethoxysilane copolymer, 3-mercaptopropyltrimethoxysilane-tetraethoxysilane copolymer, 3-mercaptopropyltriethoxysilane-tetramethoxysilane copolymer , And mercaptopropyl group-containing copolymers such as 3-mercaptopropyltriethoxysilane-tetraethoxysilane copolymer;

Mercaptomethyltrimethoxysilane-tetramethoxysilane copolymer, mercaptomethyltrimethoxysilane-tetraethoxysilane copolymer, mercaptomethyltriethoxysilane-tetramethoxysilane copolymer, mercaptomethyltriethoxysilane-tetramethoxysilane copolymer, A mercaptomethyl group-containing copolymer such as an ethoxysilane-tetraethoxysilane copolymer;

3-methacryloyloxypropyltrimethoxysilane-tetramethoxysilane copolymer, 3-methacryloyloxypropyltrimethoxysilane-tetraethoxysilane copolymer, 3-methacryloyloxypropyltriethoxysilane copolymer Tetramethoxysilane copolymer, 3-methacryloyloxypropyltriethoxysilane-tetraethoxysilane copolymer, 3-methacryloyloxypropylmethyldimethoxysilane-tetramethoxysilane copolymer, 3-methacryloyloxypropylmethyldimethoxysilane- 3-methacryloyloxypropylmethyldimethoxysilane-tetraethoxysilane copolymer, 3-methacryloyloxypropylmethyldiethoxysilane-tetramethoxysilane copolymer, and 3-methacryloxypropylmethyldimethoxysilane- Methacryloyloxypropyl group-containing copolymers such as diethoxysilane-tetraethoxysilane copolymer;

3-acryloyloxypropyltrimethoxysilane-tetramethoxysilane copolymer, 3-acryloyloxypropyltrimethoxysilane-tetraethoxysilane copolymer, 3-acryloyloxypropyltriethoxysilane- 3-acryloyloxypropyltriethoxysilane-tetraethoxysilane copolymer, 3-acryloyloxypropylmethyldimethoxysilane-tetramethoxysilane copolymer, 3-acryloyloxypropyltrimethoxysilane copolymer, 3-acryloyloxypropyltrimethoxysilane copolymer, 3-acryloyloxypropylmethyldiethoxysilane-tetramethoxysilane copolymer, and 3-acryloyloxypropylmethyldiethoxysilane-tetraethoxysilane copolymer, 3-acryloyloxypropylmethyldimethoxysilane-tetraethoxysilane copolymer, Acryloyloxypropyl group-containing copolymers such as copolymers;

Vinyltrimethoxysilane-tetramethoxysilane copolymer, vinyltrimethoxysilane-tetraethoxysilane copolymer, vinyltriethoxysilane-tetramethoxysilane copolymer, vinyltriethoxysilane-tetraethoxysilane copolymer Polymer, vinylmethyldimethoxysilane-tetramethoxysilane copolymer, vinylmethyldimethoxysilane-tetraethoxysilane copolymer, vinylmethyldiethoxysilane-tetramethoxysilane copolymer, and vinylmethyldiethoxysilane-tetra Vinyl group-containing copolymers such as methoxy silane copolymers;

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-aminopropyltrimethoxysilane- Methyldiethoxysilane-tetramethoxysilane copolymer, and amino group-containing copolymers such as 3-aminopropylmethyldiethoxysilane-tetraethoxysilane copolymer.

These silane-based compounds (D) are often liquids. When the silane compound is compounded in the pressure-sensitive adhesive composition, the amount thereof is about 0.03 to 2 parts by weight, preferably about 0.05 to 2 parts by weight, based on 100 parts by weight of the acrylic copolymer (A). When the amount of the silane compound relative to 100 parts by weight of the acrylic copolymer is 0.03 part by weight or more, adhesion between the pressure-sensitive adhesive layer and the glass substrate is improved. When the amount is less than 2 parts by weight, the silane-based compound tends to be inhibited from bleeding out from the pressure-sensitive adhesive layer.

The above-described pressure-sensitive adhesive may further contain a crosslinking catalyst, a weathering stabilizer, a tackifier, a plasticizer, a softener, a dye, a pigment, an inorganic filler and a resin other than the acrylic copolymer (A). It is also useful to form a harder pressure-sensitive adhesive layer by blending an ultraviolet-curable compound with a pressure-sensitive adhesive to form a pressure-sensitive adhesive layer and then curing by irradiation with ultraviolet rays. In particular, when a crosslinking catalyst is blended with a crosslinking agent in a pressure-sensitive adhesive, it is possible to prepare a pressure-sensitive adhesive layer with aging for a short time. In the obtained optical film with a pressure-sensitive adhesive, peeling or peeling may occur between the optical film and the pressure- It is possible to inhibit foaming from occurring or to improve the workability. Examples of the crosslinking catalyst include amines such as hexamethylenediamine, ethylenediamine, polyethyleneimine, hexamethylenetetramine, diethylenetriamine, triethylenetetramine, isophoronediamine, trimethylenediamine, polyamino resin, melamine resin Based compounds and the like. When an amine compound is added to the pressure-sensitive adhesive as a crosslinking catalyst, an isocyanate compound is very suitable as the crosslinking agent.

[Optical film with pressure-sensitive adhesive]

In the optical film with a pressure-sensitive adhesive of the present invention, a pressure-sensitive adhesive layer formed of the pressure-sensitive adhesive composition as described above is provided on at least one surface of the optical film. The optical film used herein is a film having optical characteristics, and examples thereof include a polarizing plate and a retardation film.

The polarizing plate is an optical film having a function of emitting polarized light with respect to incident light such as natural light. The polarizing plate includes a linearly polarizing plate having a property of absorbing linearly polarized light having a vibration plane in a certain direction incident on the film surface and transmitting linearly polarized light having a vibration plane orthogonal thereto and linearly polarized light having a vibration plane in a certain direction incident on the film surface A polarized light separating film having a property of reflecting linearly polarized light having a vibration plane perpendicular to it, and an elliptically polarizing plate laminated with a polarizing plate and a retardation film to be described later. A specific example of a polarizing plate, particularly, a linear polarizing film (also referred to as a polarizer or a polarizer film) is a monoaxially stretched polyvinyl alcohol resin film in which a dichromatic dye such as iodine or a dichromatic dye is adsorbed and aligned .

The retardation film is an optical film exhibiting optical anisotropy, and includes, for example, polyvinyl alcohol, polycarbonate, polyester, polyallylate, polyimide, polyolefin, polycycloolefin, polystyrene, polysulfone, polyethersulfone, polyvinylidene A stretched film obtained by stretching a polymer film comprising fluoride / polymethyl methacrylate, liquid crystal polyester, acetylcellulose, saponified ethylene-vinyl acetate copolymer, polyvinyl chloride, etc. to a degree of 1.01 to 6 times. Among them, a polymer film obtained by uniaxially or biaxially stretching a polyolefin film or a cycloolefin-based resin film is preferable. A monoaxial phase difference film, a wide viewing angle phase difference film, and a low light modulus phase difference film. However, the present invention is also applicable to all of them.

The cycloolefin resin is a thermoplastic resin having a monomer unit of, for example, norbornene or tetracyclododecene (also known as dimethanooctahydronaphthalene) or a cycloolefin represented by a derivative thereof, and the ring- A hydrogenated product of a ring-opening copolymer using a polymer or two or more kinds of cycloolefins, or an addition copolymer of a cycloolefin and an aromatic compound having a chain olefin or vinyl group. In addition, a polar group may be introduced.

Commercially available thermoplastic cycloolefin resins include, for example, "TOPAS" produced by TOPAS ADVANCED POLYMERS GmbH of Germany and "TOPAS" sold by Polyplastics Corporation in Japan and "ARTON" sold by JSR Co., "ZEONEX" and "ZEONOR" sold by Nippon Zeon Co., Ltd., and "APEL" sold by Mitsui Chemicals, Inc. (all trade names).

When such a cycloolefin-based resin is to be formed into a film, known film forming techniques such as a solvent casting method and a melt extrusion method are suitably used for the film formation. A formed cycloolefin resin film or a cycloolefin resin film stretched and given a phase difference is also commercially available. For example, "Arton film" sold by JSR Corporation, "Zeonoah film" sold by Japan Xion Co., "Essa" and "SCA40" sold by Sekisui Chemical Co., (All trade names), and they can be suitably used.

When a pressure-sensitive adhesive layer is formed on an optical film containing a retardation film and is bonded to glass through the pressure-sensitive adhesive layer, if the moisture permeability of the retardation film is low, moisture is not easily released from the pressure-sensitive adhesive layer, There were many. On the other hand, when an optical film containing a retardation film is used as the optical film in the optical film with a pressure-sensitive adhesive according to the present invention, the retardation film is formed by the cup method defined in JIS Z 0208, (M < ² > 24 hr) or less, which is measured at a relative humidity of 300 g / m < ² > Examples of the low-moisture-permeability resin film include a polyolefin film and a cycloolefin-based resin film, as described above. These polyolefin films and cycloolefin-based resin films generally have a moisture permeability of 300 g / (m ² · 24 hr) or less under the conditions of a temperature of 40 ° C. and a relative humidity of 90%.

A film exhibiting optical anisotropy by application and orientation of a liquid crystal compound or a film exhibiting optical anisotropy by application of an inorganic layer compound can also be used as a retardation film. Such a retardation film is referred to as a temperature-compensated retardation film. In addition, a film in which a rod-shaped liquid crystal sold under the trade name of "LC film" by Shin-Nippon Petroleum Co., A film in which a rod-shaped liquid crystal sold under the trade name of "NH film" is oriented in an oblique direction; a film in which a circular liquid crystal sold under the trade name of "WV film "Quot; VAC film ", and biaxial orientation type films sold under the trade name "newVAC film" by Sumitomo Chemical Co., Ltd., and the like.

A protective film adhered to these optical films can also be used as an optical film. As the protective film, a transparent resin film is used. As the transparent resin, for example, an acetylcellulose-based resin represented by triacetylcellulose or diacetylcellulose, a methacrylic resin such as polymethylmethacrylate, a polyester resin, Polyolefin resins, polycarbonate resins, polyetheretherketone resins, and polysulfone resins. The resin constituting the protective film may be blended with a UV absorber such as a salicylate ester compound, a benzophenone compound, a benzotriazole compound, a triazine compound, a cyanoacrylate compound or a nickel complex salt compound. As the protective film, an acetylcellulose-based resin film such as a triacetylcellulose film is suitably used. The acetylcellulose-based resin film may be provided with a proper retardation, or may be substantially in a non-oriented state in the in-plane direction and the thickness direction, and may be formed as a retardation film.

Among the optical films described above, the linear polarizer is often used in a state that a protective film is attached to one side or both sides of a polarizing film constituting the linear polarizer, for example, a polarizing film made of a polyvinyl alcohol-based resin. The above-mentioned elliptically polarizing plate is a laminate of a linearly polarizing plate and a retardation film, but many of the linearly polarizing plates also have a protective film adhered to one or both sides of the polarizing film. When a pressure-sensitive adhesive layer according to the present invention is formed on such an elliptically polarizing plate, a pressure-sensitive adhesive layer is usually formed on the side of the retardation film.

As described above, from the viewpoint of enhancing the durability of the pressure-sensitive adhesive layer provided thereon, the optical film exhibiting a moisture permeability of generally 300 g / (m ² · 24 hr) or less under the conditions of a temperature of 40 ° C. and a relative humidity of 90% It is one of them. As a typical example thereof, there can be mentioned a polarizing plate in which a retardation film made of a cycloolefin-based resin is stuck to one side of the above-described polarizing film and an optional protective film is stuck to the other side of the polarizing film. In this case, the weight average molecular weight of the acrylic copolymer (A) forming the pressure-sensitive adhesive layer is preferably at least 1,000,000.

On the other hand, the optical film exhibiting a water vapor permeability higher than 300 g / (m ² · 24 hr) under the conditions of a temperature of 40 ° C. and a relative humidity of 90% is different from that of the acrylic copolymer of the pressure- And it is one of preferable ones for the application of the present invention from the viewpoint that good results can be obtained even when a material having a small molecular weight is used. As a typical example thereof, there can be mentioned a polarizing plate in which a protective film or a retardation film made of an acetylcellulose-based resin is stuck to one side of the above-described polarizing film and an optional protective film is stuck to the other side of the polarizing film. In this case, as described above, good results can be obtained even when the weight average molecular weight of the acrylic copolymer (A) forming the pressure-sensitive adhesive layer is reduced to about 500,000.

In the optical film with a pressure-sensitive adhesive of the present invention, it is preferable to attach a release film to the surface of the pressure-sensitive adhesive layer and protect it from adhering until use. The release film used herein may be a film made of various resins such as polyethylene terephthalate, polybutylene terephthalate, polycarbonate, and polyarylate, and may be subjected to silicone treatment The same release mold process may be performed, or the like.

The optical film with a pressure-sensitive adhesive may be obtained by, for example, a method of laminating an optical film on a pressure-sensitive adhesive layer obtained by applying the pressure-sensitive adhesive composition described above onto the above-mentioned release film to form a pressure-sensitive adhesive layer, a method of forming a pressure- And a method in which a release film is adhered to the surface of the pressure-sensitive adhesive to protect the pressure-sensitive adhesive surface and an optical film with a pressure-sensitive adhesive is formed.

The thickness of the pressure-sensitive adhesive layer is not particularly limited, but it is preferably 30 占 퐉 or less, more preferably 10 占 퐉 or more, and further preferably 10 to 20 占 퐉. If the thickness of the pressure-sensitive adhesive layer is 30 占 퐉 or less, the adhesiveness under high temperature and high humidity is improved, the possibility of peeling or peeling between the glass substrate and the pressure-sensitive adhesive layer tends to be lowered, . Further, if the thickness of the adhesive layer is 10 占 퐉 or more, even if the size of the optical film adhered thereto changes, the adhesive layer follows the change of the dimension thereof, and thus the difference between the brightness of the peripheral edge portion of the liquid crystal cell and the brightness of the center portion , And it is preferable in that the white color and the smear tend to be suppressed.

[Optical laminate]

The optical film with a pressure-sensitive adhesive of the present invention can be laminated on a glass substrate on the pressure-sensitive adhesive layer side to obtain an optical laminate. When an optical film with an adhesive is laminated on a glass substrate to form an optical laminate, for example, the release film may be peeled off from the optical film with an adhesive attached as described above and the exposed adhesive layer may be applied to the surface of the glass substrate. Here, examples of the glass substrate include glass substrates for liquid crystal cells, glass for antiglare, glass for sunglasses, and the like. Among them, an optical film (upper polarizing film) with a pressure-sensitive adhesive is laminated on a glass substrate on the front side (viewing side) of the liquid crystal cell and an optical film (lower polarizing film) with another adhesive is laminated on the glass substrate on the back side of the liquid crystal cell Is preferable in that it can be used as a liquid crystal display device. As the material of the glass substrate, for example, soda lime glass, low alkali glass, non-alkali glass and the like can be mentioned, but non-alkali glass is preferably used for the liquid crystal cell.

When an optical film with a pressure-sensitive adhesive is attached to a glass substrate to form an optical laminate, if any defects are found, the optical film is peeled off from the glass substrate and the optical film with a new pressure- There is work. In the optical film with a pressure-sensitive adhesive of the present invention, when the rework process is carried out, the pressure-sensitive adhesive layer is peeled off with the optical film, and haze or residual adhesive remaining on the surface of the glass substrate in contact with the pressure- It is easy to attach the optical film with the adhesive again to the glass substrate after peeling. That is, the so-called reworkability is excellent.

The optical laminate of the present invention can be used as a liquid crystal cell of a liquid crystal display device. The liquid crystal display device formed by the optical laminate of the present invention can be applied to a liquid crystal display for a personal computer including a notebook type, a desktop type, a PDA (Personal Digital Assistance), a television, a vehicle display, A video camera, an electronic desk calculator, a clock, and the like.

Example

Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited to these examples. In the examples, " part (s) " and "% " representing amounts used or contents are by weight unless otherwise specified. In the following examples, the (meth) acrylic acid ester (A-1) represented by the above formula (I) is referred to as "monomer (A-1)", the unsaturated monomer having one olefinic double bond and at least one aromatic ring (A-2) "represented by the formula (A-2) and the N-alkoxyalkyl (meth) acrylamide The monomer (A-4) is referred to as " monomer (A-4) ".

In the following examples, the measurement of the weight average molecular weight and the number average molecular weight was carried out in a GPC apparatus as four columns "TSK gel XL" (manufactured by TOSOH CORPORATION) and sold by Showa Denko Co., Ltd. One sample of "Shodex GPC KF-802", in total 5, was placed in series. Using tetrahydrofuran as the eluent, a sample concentration of 5 mg / ml, a sample introduction amount of 100 μl, a temperature of 40 ° C., a flow rate of 1 ml / The conditions were carried out by standard polystyrene conversion.

First, the acrylic copolymer (A) specified in the present invention and the comparative acrylic copolymer excluding the specification are produced.

Polymerization Example  One

81.8 parts of ethyl acetate as a solvent, 68.4 parts of butyl acrylate as monomer (A-1) and 20.0 parts of methyl acrylate as polymerization initiators were added to a reaction vessel equipped with a stirrer, a thermometer and a stirrer, 2.0 parts of N- (methoxymethyl) acrylamide as the monomer (A-3) and 1.0 part of 2-hydroxyethyl acrylate as the monomer (A-4) , And the inside temperature was raised to 55 캜 while replacing the air in the apparatus with nitrogen gas so as not to contain oxygen. Thereafter, a total amount of a solution obtained by dissolving 0.14 part of azobisisobutyronitrile (polymerization initiator) in 10 parts of ethyl acetate was added. Ethyl acetate was continuously fed into the reaction vessel at an addition rate of 17.3 parts / hr while the internal temperature was kept at 54 to 56 ° C, and the reaction was continued at the time when the concentration of the acrylic copolymer became 35% , The temperature was maintained at this temperature until the addition of ethyl acetate was stopped and further 12 hours elapsed from the start of the addition of ethyl acetate. Finally, ethyl acetate was added to adjust the concentration of the acrylic copolymer to 20% to prepare an ethyl acetate solution of an acrylic copolymer. The acrylic copolymer thus obtained had a weight average molecular weight Mw of 1,460,000 and a Mw / Mn value of 3.7 as measured by GPC in terms of polystyrene. This is referred to as an acrylic copolymer A.

Polymerization Example  2

An ethyl acetate solution of an acrylic copolymer was prepared in the same manner as in Polymerization Example 1 except that the amount of butyl acrylate in the monomer composition was changed to 69.4 parts and the amount of N- (methoxymethyl) acrylamide was changed to 1.0 part. The acrylic copolymer obtained had a weight average molecular weight Mw of 1,515,000 and a Mw / Mn value of 3.8 as measured by GPC in terms of polystyrene. This is referred to as acrylic copolymer B.

Polymerization Example  3

An ethyl acetate solution of an acrylic copolymer was prepared in the same manner as in Polymerization Example 1 except that the amount of butyl acrylate was changed to 69.9 parts and the amount of N- (methoxymethyl) acrylamide was changed to 0.5 parts in the monomer composition. The acrylic copolymer thus obtained had a weight average molecular weight Mw of 1,410,000 and a Mw / Mn value of 3.7 as measured by GPC in terms of polystyrene. This is referred to as an acrylic copolymer C.

Polymerization Example  4

An ethyl acetate solution of an acrylic copolymer was prepared in the same manner as in Polymerization Example 1 except that the amount of butyl acrylate in the monomer composition was changed to 70.1 parts and the amount of N- (methoxymethyl) acrylamide was changed to 0.3 part. The acrylic copolymer obtained had a weight average molecular weight Mw of 1,600,000 as measured by GPC in terms of polystyrene, and Mw / Mn of 4.7. This is referred to as an acrylic copolymer D.

Polymerization Example  5

An ethyl acetate solution of an acrylic copolymer was prepared in the same manner as in Polymerization Example 1 except that the amount of butyl acrylate was changed to 70.3 parts and the amount of N- (methoxymethyl) acrylamide was changed to 0.1 parts in the monomer composition. The acrylic copolymer obtained had a weight average molecular weight Mw of 1.66 million as measured by GPC in terms of polystyrene, and Mw / Mn of 4.4. This is referred to as an acrylic copolymer E.

Polymerization Example  6

(Butyl methacrylate) was used instead of N- (methoxymethyl) acrylamide as the monomer (A-3) to 0.5 part, The other components were the same as Polymerization Example 1 to prepare an ethyl acetate solution of an acrylic copolymer. The obtained acrylic copolymer had a weight average molecular weight Mw of 153,000 and a Mw / Mn of 3.8 as measured by GPC in terms of polystyrene. This is referred to as an acrylic copolymer F.

Polymerization Example  7

The amount of butyl acrylate in the monomer composition was changed to 69.8 parts and the amount of the monomer (A-3) was changed to 0.6 parts by using N- (butoxymethyl) acrylamide instead of N- (methoxymethyl) acrylamide, The other components were the same as Polymerization Example 1 to prepare an ethyl acetate solution of an acrylic copolymer. The acrylic copolymer obtained had a weight average molecular weight Mw of 4.50 in terms of polystyrene as measured by GPC and a Mw / Mn value of 4.8. This is referred to as an acrylic copolymer G.

Polymerization Example  8

An ethyl acetate solution of an acrylic copolymer was prepared in the same manner as in Polymerization Example 7 except that the amount of butyl acrylate in the monomer composition was changed to 69.6 parts and the amount of acrylic acid was changed to 0.8 parts. The acrylic copolymer obtained had a weight average molecular weight Mw in terms of polystyrene by GPC of 142,000 and an Mw / Mn of 4.7. This is referred to as an acrylic copolymer H.

Polymerization Example  9

An ethyl acetate solution of an acrylic copolymer was prepared in the same manner as in Polymerization Example 7 except that the amount of butyl acrylate in the monomer composition was changed to 70.1 parts and the amount of acrylic acid was changed to 0.3 part.

The obtained acrylic copolymer had a weight average molecular weight Mw of 13800 and a Mw / Mn of 4.6 in terms of polystyrene by GPC. This is referred to as an acrylic copolymer I.

Polymerization Example  10

An ethyl acetate solution of an acrylic copolymer was prepared in the same manner as in Polymerization Example 7 except that the amount of butyl acrylate in the monomer composition was changed to 70.0 parts and the amount of acrylic acid was changed to 0.4 part.

The obtained acrylic copolymer had a weight average molecular weight Mw of 137,000 and a Mw / Mn of 4.2 as measured by GPC in terms of polystyrene. This is referred to as an acrylic copolymer J.

Polymerization Example  11

(Isobutoxymethyl) acrylamide (also referred to as N- (2-methylpropoxymethyl) acrylamide] was used instead of N- (butoxymethyl) acrylamide as the monomer (A-3) 0.6 part) was used, and otherwise, an ethyl acetate solution of an acrylic copolymer was prepared in the same manner as in Polymerization Example 10. The acrylic copolymer obtained had a weight average molecular weight Mw in terms of polystyrene by GPC of 12,700 and a Mw / Mn of 4.7. This is referred to as an acrylic copolymer K.

Polymerization Example  12 (for comparison)

An ethyl acetate solution of an acrylic copolymer was prepared in the same manner as in Polymerization Example 1 except that monomer (A-3) was not used and the amount of butyl acrylate was changed to 70.4 parts. The obtained acrylic copolymer had a weight average molecular weight Mw of 15800 and a Mw / Mn of 4.8 in terms of polystyrene by GPC. This is referred to as an acrylic copolymer W.

Polymerization Example  13 (for comparison)

An ethyl acetate solution of an acrylic copolymer was prepared in the same manner as in polymerization example 1 except that the monomer composition was changed to 98.6 parts of butyl acrylate, 1.0 part of 2-hydroxyethyl acrylate, and 0.4 part of acrylic acid. The acrylic copolymer obtained had a weight average molecular weight Mw in terms of polystyrene as measured by GPC of 12.3 million, and Mw / Mn of 3.9. This is referred to as acrylic copolymer X.

Table 1 summarizes the monomer composition in the above Polymerization Examples 1 to 13, the weight average molecular weight of the obtained acrylic copolymer and Mw / Mn. In the table, the symbols in the column of monomer composition mean the following monomers, respectively.

(A-1)

BA: butyl acrylate,

MA: methyl acrylate,

(A-2)

PEA2: 2- (2-phenoxyethoxy) ethyl acrylate,

(A-3)

MMAM: N- (methoxymethyl) acrylamide,

BMAM: N- (butoxymethyl) acrylamide,

IBMAM: N- (isobutoxymethyl) acrylamide

      [Alias N- (2-methylpropoxymethyl) acrylamide],

(A-4)

HEA: 2-hydroxyethyl acrylate,

AA: Acrylic acid.

Next, examples and comparative examples in which a pressure-sensitive adhesive is prepared using the acrylic copolymer prepared above and applied to an optical film will be shown. In the following examples, the following were used as ionic compounds, crosslinking agents and silane-based compounds, respectively. The initial names of the crosslinking agent and silane-based compounds are trade names.

<Ionic Compound>

N-octyl-4-methylpyridinium hexafluorophosphate (having a structure of the following formula, melting point 44 캜).

<Cross-linking agent>

Colonate L: Trimethylolpropane adduct of tolylene diisocyanate An ethyl acetate solution (solid content concentration 75%) of the duct body was obtained from Japan Polyurethane Co., Ltd.

&Lt; Silane-based compound &

KBM-403: 3-glycidoxypropyltrimethoxysilane, liquid, obtained from Shin-Etsu Chemical Co., Ltd.

[ Example  1 to 13 and Comparative Example  1-2]

(a) Production of pressure-sensitive adhesive

Using the 20% ethyl acetate solution of the acrylic copolymer prepared in Polymerization Examples 1 to 13, the ionic compound and the crosslinking agent "Colonate L" were added in amounts shown in Table 2 and 100 parts of the silane compound "KBM -403 "was mixed in an amount of 0.5 part, and ethyl acetate was further added to give a solid content concentration of 13% to obtain a pressure-sensitive adhesive composition. As described above, the crosslinking agent "Colonate L" is an ethyl acetate solution having a solid content concentration of 75%, and the addition amount shown in Table 2 is the amount of solid content (effective ingredient).

(b) Production of optical film with adhesive

Each of the above pressure-sensitive adhesive compositions was coated on the release-treated surface of a release-treated polyethylene terephthalate film (trade name "PLR-382050", available from Lintec Co., Ltd., referred to as a separator) with an applicator so as to have a thickness after drying of 20 μm And dried at 100 DEG C for 1 minute to obtain a sheet-like pressure-sensitive adhesive. Then, a protective film of 80 탆 thick made of triacetyl cellulose was laminated on one side of the polarizing film in which iodine was adsorbed and oriented on polyvinyl alcohol, and on the other side thereof, a retardation film of a cycloolefin resin Sensitive adhesive on the side of the cycloolefin-based resin film of the three-layered polarizing plate in which a film (having a moisture permeability of 42 g / (m ² · 24 hr) at a temperature of 40 ° C. and a relative humidity of 90% The surface (pressure-sensitive adhesive side) was laminated by a laminator and then cured for 7 days at a temperature of 23 캜 and a relative humidity of 65% to prepare a polarizer with a pressure-sensitive adhesive.

(c) Evaluation of Antistatic Property of Optical Film with Adhesive

The surface resistance value of the pressure-sensitive adhesive layer exposed after peeling off the separator from the obtained polarizer with a pressure-sensitive adhesive was measured with a surface intrinsic resistance measuring device ("Hirest-up MCP-HT450" (trade name), manufactured by Mitsubishi Chemical Corporation) And evaluated the preventability. The surface resistance value is 10 ¹¹ Ω / □ Order or less, it is possible to obtain good antistatic property. Evaluation of the antistatic property was carried out immediately after curing of the polarizing plate with a pressure-sensitive adhesive was completed. The results are summarized in the column of &quot; surface resistance value &quot;

(d) Fabrication of optical laminate and evaluation of durability

The separator was peeled off from the polarizer with a pressure-sensitive adhesive prepared in (b), and the pressure-sensitive adhesive side was attached to both surfaces of a glass substrate for liquid crystal cell ("EAGLEXG" (trade name) . The following four kinds of durability tests were performed on this optical laminate.

(1) wet heat resistance test in which the sample is stored at a temperature of 60 DEG C and a relative humidity of 90% for 300 hours,

(2) 80 占 폚 heat resistance test in which the sample was stored under a drying condition at a temperature of 80 占 폚 for 300 hours,

(3) 100 占 폚 heat resistance test for storage for 300 hours under a drying condition at a temperature of 100 占 폚,

(4) A thermal shock resistance test in which the process of lowering the temperature from 70 DEG C to -30 DEG C and raising the temperature to 70 DEG C for 1 cycle (1 hour) is repeated 100 times.

The optical laminate after each test was visually observed, and the appearance change state was classified into the following criteria. The results are summarized in the column of &quot; durability &quot; In Table 2, &quot; inner HS &quot; means heat shock resistance.

<Evaluation Criteria of Durability Test>

◎: No change in appearance such as peeling, peeling, and foaming can be seen at all.

○: Almost no change in appearance such as peeling, peeling, and foaming is observed.

Δ: Appearance of peeling, peeling, foaming and the like are slightly visible.

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

(e) Evaluation of lithographic properties of optical film with adhesive

Evaluation of reworkability was carried out as follows. First, the polarizer with a pressure-sensitive adhesive prepared in the above (b) was cut into test pieces having a size of 25 mm x 150 mm. Next, this test piece was affixed to the pressure-sensitive adhesive side with a bonding apparatus ("Lamy Packer" (trade name) manufactured by Fuji Plastics Co., Ltd.) to a glass substrate for a liquid crystal cell and heated at a temperature of 50 ° C. and a pressure of 5 kg / cm ² kPa) for 20 minutes in an autoclave treatment. Then, the resultant was heat-treated at 70 ° C for 2 hours, and then kept in an oven at 50 ° C for 48 hours. Thereafter, the polarizing plate was peeled off from the adhesion test piece in an atmosphere at a temperature of 23 ° C and a relative humidity of 50% At a speed of 180 deg. (In a direction along the glass substrate surface while being turned upside down). The state of the surface of the glass substrate after peeling was observed and classified according to the following criteria. The results are summarized in the column of &quot; reworkability &quot; in Table 2.

<Evaluation Criteria for Re-workability>

◎: Haze is not completely confirmed on the surface of the glass substrate.

Good: Haze is hardly observed on the surface of the glass substrate.

DELTA: Haze or the like is confirmed on the surface of the glass substrate.

X: Residual adhesive remained on the surface of the glass substrate.

* The amount of the ionic compound and the crosslinking agent to be added is preferably 100 parts by weight of the acrylic copolymer

As can be seen from Tables 1 and 2, the pressure-sensitive adhesive composition was prepared by blending a predetermined amount of each of an ionic compound and a crosslinking agent in the acrylic copolymer (A) specified in the present invention, and the pressure- 1 to 13 exhibited high durability in both of the humid condition, the 80 ° C drying condition, the 100 ° C drying condition, and the thermal shock condition, and the antistatic property and the workability were almost satisfactory.

On the other hand, Comparative Examples 1 and 2 using the acrylic copolymer in which the monomer (A-3) was not copolymerized had insufficient heat resistance at 100 占 폚.

Next, polymerization examples in which a plurality of acrylic copolymers different from the acrylic copolymer shown in Table 1 are synthesized, and other examples and comparative examples in which a pressure-sensitive adhesive is prepared using them and applied to an optical film are shown. In the following Examples and Comparative Examples, ionic compounds, crosslinking agents and silane-based compounds were the same as those shown above.

Polymerization Example  14

A reaction vessel equipped with a cooling tube, a nitrogen inlet tube, a thermometer and a stirrer was charged with 120 parts of ethyl acetate as a solvent, replacing the air in the apparatus with nitrogen gas so as not to contain oxygen and raising the internal temperature to 75 ° C. A solution obtained by dissolving 0.05 part of azobisisobutyronitrile (polymerization initiator) in 5 parts of ethyl acetate was added in an amount of 68.0 parts by weight, and 68.6 parts of butyl acrylate as monomer (A-1) and 20.0 parts of methyl acrylate , 8.0 parts of 2- (2-phenoxyethoxy) ethyl acrylate as the monomer (A-2), 0.6 parts of N- (butoxymethyl) acrylamide as the monomer (A- , 2.0 parts of 2-hydroxyethyl acrylate and 0.8 part of acrylic acid was dropped into the reaction system over 2 hours. Also, the inside temperature was kept at 74 ~ 76 ° C for 5 hours, and the reaction was completed. Finally, ethyl acetate was added to adjust the concentration of the acrylic copolymer to 40% to prepare an ethyl acetate solution of the acrylic copolymer. The acrylic copolymer obtained had a weight average molecular weight Mw of 68,000 and a Mw / Mn of 4.9 in terms of polystyrene by GPC. This is referred to as an acrylic copolymer L.

Polymerization Example  15

An ethyl acetate solution of an acrylic copolymer was prepared in the same manner as in Polymerization Example 14 except that the amount of ethyl acetate as a solvent was changed to 140 parts and the amount of azobisisobutyronitrile as a polymerization initiator was changed to 0.07 part. The acrylic copolymer obtained had a weight average molecular weight Mw of 500,000 and a Mw / Mn of 4.2 as measured by GPC in terms of polystyrene. This is referred to as an acrylic copolymer M.

Polymerization Example  16 (for comparison)

An ethyl acetate solution of an acrylic copolymer was prepared in the same manner as in Polymerization Example 14 except that the monomer (A-3) was not used and the amount of butyl acrylate was changed to 69.2 parts. The obtained acrylic copolymer had a weight average molecular weight Mw of 650,000 and a Mw / Mn of 4.5 as measured by GPC in terms of polystyrene. This is referred to as an acrylic copolymer Y.

Polymerization Example  17 (for comparison)

An ethyl acetate solution of an acrylic copolymer was prepared in the same manner as in Polymerization Example 15 except that the monomer (A-3) was not used and the amount of butyl acrylate was changed to 69.2 parts. The acrylic copolymer obtained had a weight average molecular weight Mw of 5,100,000 and a Mw / Mn value of 4.2 as measured by GPC in terms of polystyrene. This is referred to as an acrylic copolymer Z.

Table 3 summarizes the monomer composition in the above Polymerization Examples 14 to 17, the weight average molecular weight of the obtained acrylic copolymer and the list of Mw / Mn. In the table, the meanings of the symbols in the column of monomer composition are the same as those in Table 1.

[ Example  14 to 17 and Comparative Example  3-6]

(a) Production of pressure-sensitive adhesive

Using the 40% ethyl acetate solution of the acrylic copolymer prepared in Polymerization Examples 14 to 17, the ionic compound and the crosslinking agent "Colonate L" were added to 100 parts of the respective solid components (crosslinking agent " And 0.5 part of the silane compound "KBM-403"), and ethyl acetate was further added so that the solid concentration became 29% to prepare a pressure-sensitive adhesive composition.

(b) Production of optical film with adhesive

Each of the above pressure-sensitive adhesive compositions was coated on the release-treated surface of a release-treated polyethylene terephthalate film (trade name "PLR-382050", available from Lintec Co., Ltd., referred to as a separator) with an applicator so as to have a thickness after drying of 20 μm And dried at 100 DEG C for 1 minute to obtain a sheet-like pressure-sensitive adhesive. Then, a protective film of 80 탆 thick made of triacetyl cellulose was laminated on one side of the polarizing film on which iodine was adsorbed and oriented on polyvinyl alcohol, and on the other side thereof, a 41 탆 -thick retardation film made of triacetyl cellulose (Adhesive surface) opposite to the separator of the sheet-like pressure-sensitive adhesive obtained above was laminated on the triacetyl cellulose surface having a thickness of 41 占 퐉 of the laminated three-layered polarizing plate by a laminator, Curing for 7 days to prepare a polarizing plate with a pressure-sensitive adhesive.

(c) Evaluation of Antistatic Property of Optical Film with Adhesive

With respect to the resulting polarizer with a pressure-sensitive adhesive, the surface resistance values of the pressure-sensitive adhesive layers were measured in the same manner as in Examples 1 to 13 (c), and the results are summarized in the column of "surface resistance value"

(d) Fabrication of optical laminate and evaluation of durability

The durability test was carried out on the polarizing plate with a pressure-sensitive adhesive prepared in the above (b) in the same manner as in Examples 1 to 13 (d), and the results were classified according to the same criteria as in Table 2, Durability. "

(e) Evaluation of lithographic properties of optical film with adhesive

With respect to the polarizer with a pressure-sensitive adhesive prepared in (b) above, evaluation of reworkability was carried out in the same manner as in (e) of Examples 1 to 13 and the results were classified on the basis of Table 4 In the column of "re-workability" of.

* The amount of the ionic compound and the crosslinking agent to be added is preferably 100 parts by weight of the acrylic copolymer

As can be seen from Tables 3 and 4, even if the acrylic copolymer (A) specified in the present invention has a relatively small value, ie, a weight average molecular weight of 500,000 to 1,000,000, the ionic compound and the crosslinking agent And a pressure sensitive adhesive layer was formed on the triacetyl cellulose surface of a polarizing plate having triacetyl cellulose as a protective film, which is an acetylcellulose resin, to form a pressure-sensitive adhesive composition. It was possible to impart high durability to any of the conditions, and to achieve almost satisfactory antistatic properties and reworkability.

On the other hand, Comparative Examples 3 to 6 using the acrylic copolymer in which the monomer (A-3) was not copolymerized were unsatisfactory in heat resistance and heat resistance at 100 占 폚 and partly unsatisfactory even at 80 占 폚 heat resistance or thermal shock resistance . In Comparative Example 5 in which the acrylic copolymer Z having a low weight average molecular weight of about 500,000 was used as the monomer (A-3), and the amount of the crosslinking agent was small, Comparative Example 5 in which the residue of the pressure- Respectively.

The optical film with a pressure-sensitive adhesive of the present invention is not only imparted with high antistatic property but also has durability under harsh environments, that is, durability at a high temperature of around 100 캜 when it is bonded to glass through a pressure- outstanding. This optical film with a pressure-sensitive adhesive is suitably used for a liquid crystal display device.

Claims (10)

A pressure-sensitive adhesive optical film comprising an optical film and a pressure-sensitive adhesive layer formed on at least one side thereof,
The optical film exhibited a water vapor permeability of 300 g / (m ² · 24 hr) or less under the condition of a temperature of 40 ° C. and a relative humidity of 90%
The pressure-sensitive adhesive layer is formed of a pressure-sensitive adhesive composition containing 100 parts by weight of an acrylic copolymer (A), 0.3 to 12 parts by weight of an ionic compound (B) having an organic cation and 0.1 to 5 parts by weight of a crosslinking agent (C)
The acrylic copolymer (A) contains 80 to 96% by weight of (A-1), 1 to 15% by weight of (A-2), 0.1 to 5% by weight of (A-3) Of a monomer mixture comprising (A-4)
(A-1) is represented by the following formula (I)

(Wherein R ₁ is a hydrogen atom or a methyl group and R ₂ is an alkyl group having 1 to 14 carbon atoms which may be substituted with an alkoxy group having 1 to 10 carbon atoms)
(A-2) is an unsaturated monomer having one olefinic double bond and at least one aromatic ring in the molecule,
(A-3) is represented by the following formula (II)

(Meth) acrylamide represented by the following formula ( ₃ ): wherein R ₃ represents a hydrogen atom or a methyl group, R ₄ represents an alkyl group, and m represents an integer of 1 to 8,
(A-4) is an unsaturated monomer having a polar functional group. The method according to claim 1,
The unsaturated monomer (A-2) having an aromatic ring is represented by the following formula (III)

(Meth) acrylic group-containing (meth) acrylic compound represented by the following formula ( ₅ ): wherein R ₅ represents a hydrogen atom or a methyl group, n represents an integer of 1 to 8 and R ₆ represents a hydrogen atom, an alkyl group, an aralkyl group or an aryl group &Lt; / RTI &gt; The method according to claim 1 or 2,
In the formula (II) representing the N-alkoxyalkyl (meth) acrylamide (A-3), R ₄ is an alkyl group having 1 to 6 carbon atoms and m is an integer of 1 to 4. The method of claim 3,
The N-alkoxyalkyl (meth) acrylamide (A-3)
N- (methoxymethyl) acrylamide,
N- (ethoxymethyl) acrylamide,
N- (propoxymethyl) acrylamide,
N- (1-methylethoxymethyl) acrylamide,
N- (1-methylpropoxymethyl) acrylamide,
N- (2-methylpropoxymethyl) acrylamide,
N- (butoxymethyl) acrylamide,
N- (1,1-dimethylethoxymethyl) acrylamide,
N- (2-methoxyethyl) acrylamide,
N- (2-ethoxyethyl) acrylamide,
N- (2-propoxyethyl) acrylamide,
N- [2- (1-methylethoxy) ethyl] acrylamide,
N- [2- (1-methylpropoxy) ethyl] acrylamide,
N- [2- (2-methylpropoxy) ethyl] acrylamide,
N- (2-butoxyethyl) acrylamide, or
N- [2- (1,1-dimethylethoxy) ethyl] acrylamide. The method according to claim 1 or 2,
The unsaturated monomer (A-4) having a polar functional group has a polar functional group selected from the group consisting of a free carboxyl group, a hydroxyl group, an amino group, and an epoxy ring. The method according to claim 1 or 2,
The crosslinking agent (C) contains an isocyanate compound. The method according to claim 1 or 2,
Wherein the pressure-sensitive adhesive composition further comprises 0.03 to 2 parts by weight of the silane compound (D) based on 100 parts by weight of the acrylic copolymer (A). The method according to claim 1 or 2,
Wherein the optical film is selected from the group consisting of a polarizing plate and a retardation film. The method according to claim 1 or 2,
Wherein a release film is adhered to the surface of the pressure-sensitive adhesive layer. An optical laminate comprising a glass substrate and a pressure-sensitive adhesive optical film of claim 1 or 2 laminated on a glass substrate on the pressure-sensitive adhesive layer side.