KR102126048B1 - Adhesive film for polarizing plate, adhesive composition for polarizing plate for the same, polarizing plate comprising the same and optical display apparatus comprising the same - Google Patents

Abstract

(Meth)acrylate having an alkyl group having 4 to 8 carbon atoms; (Meth)acrylate having a hydroxyl group; And a (meth)acrylic copolymer of a monomer mixture comprising at least one of a (meth)acrylate having an alkyl group having 1 to 3 carbon atoms and a (meth)acrylic monomer having an amide group, and satisfying Equations 1 and 2 An adhesive film for a polarizing plate, a pressure-sensitive adhesive composition for a polarizing plate, a polarizing plate comprising the same, and an optical display device including the same are provided.

Description

Adhesive film for polarizing plate, adhesive composition for polarizing plate therefor, polarizing plate comprising the same, and optical display device including the same SAME}

The present invention relates to an adhesive film for a polarizing plate, an adhesive composition for a polarizing plate therefor, a polarizing plate comprising the same, and an optical display device including the same.

The liquid crystal display device includes a liquid crystal panel and a polarizing plate attached to both sides of the liquid crystal panel. The polarizing plate includes a polarizer and a protective film formed on one or both surfaces of the polarizer to protect the polarizer. The polarizing plate is attached to the liquid crystal panel by an adhesive film for polarizing plates.

The adhesive film for polarizing plates is prepared by applying a predetermined thickness on a release film and then drying it. The adhesive film for a polarizing plate is a laminated film, an adhesive film for a polarizing plate, and a release film are laminated, packaged, stored and/or transported. The release film prevents the adhesive film for the polarizing plate from being contaminated from foreign substances. However, during packaging, storage, and transportation of the adhesive film for a polarizing plate, it may contact with external solid particles, and this may cause pressing of the adhesive film due to the solid particles. The pressing of such an adhesive film is called a dent.

Although a release film is formed on the pressure-sensitive adhesive film, there is a limitation in resolving the pressure of the pressure-sensitive adhesive film. The polarizing plate including the pressure-sensitive adhesive film may be deteriorated in screen quality. Meanwhile, the adhesive film for a polarizing plate is processed after being adhered to the polarizing plate and cut. Even in this process, pressing of the adhesive film by solid particles may occur. Therefore, there is a need for an adhesive film that is capable of quickly recovering even if there is no pressing or even pressing of the adhesive film due to solid particles.

As a method of eliminating the dent of the adhesive film, there is a method of increasing the content of the curing agent or increasing the glass transition temperature of the (meth)acrylic copolymer in the adhesive film. However, when the content of the curing agent is increased, warping of the polarizing plate may occur at a high temperature. Even when the glass transition temperature of the (meth)acrylic copolymer is increased, warpage may occur at a high temperature.

Background art of the present invention is described in Japanese Patent Publication No. 2015-010192.

An object of the present invention is the adhesive film for a polarizing plate capable of suppressing the pressing of the adhesive film due to the solid particles and/or recovering the pressing formed by the solid particles at a high speed during processing, cutting, packaging and/or storage of the adhesive film. Is to provide

Another object of the present invention is to provide a pressure-sensitive adhesive film for a polarizing plate that can suppress warpage due to shrinkage of the polarizing plate (polarizer) at high temperature.

Another object of the present invention is to provide a pressure-sensitive adhesive film for a polarizing plate having an excellent light leakage suppression effect by alleviating the shrinkage of the polarizer at high temperature.

Another object of the present invention is to provide an adhesive film for a polarizing plate having excellent durability at high temperature or high temperature and high humidity, and having excellent corrosion inhibitory effect and rework property upon adhesion to a metal adherend containing an ITO film.

The adhesive film for polarizing plates of the present invention includes (meth)acrylate having an alkyl group having 4 to 8 carbon atoms; (Meth)acrylate having a hydroxyl group; And a (meth)acrylic copolymer of a monomer mixture comprising at least one of a (meth)acrylate having an alkyl group having 1 to 3 carbon atoms and a (meth)acrylic monomer having an amide group. Can satisfy:

<Equation 1>

0.20 ≤ tanδ2 ≤ 0.40

<Equation 2>

tanδ2-tanδ1 ≤ 0.04

(In the formulas 1 and 2, tanδ1 is tanδ at 23°C of the adhesive film for the polarizing plate,

tanδ2 is tanδ at 80°C of the adhesive film for polarizing plates).

The pressure-sensitive adhesive composition for a polarizing plate of the present invention includes (meth)acrylate having an alkyl group having 4 to 8 carbon atoms; (Meth)acrylate having a hydroxyl group; And a (meth)acrylic copolymer of a monomer mixture comprising at least one of a (meth)acrylate having an alkyl group having 1 to 3 carbon atoms and a (meth)acrylic monomer having an amide group, formed of the pressure-sensitive adhesive composition for a polarizing plate The adhesive film for the polarizing plate may satisfy the following Equation 1 and Equation 2:

<Equation 1>

0.20 ≤ tanδ2 ≤ 0.40

<Equation 2>

tanδ2-tanδ1 ≤ 0.04

(In Equations 1 and 2, tanδ1 is tanδ at 23°C of the adhesive film for the polarizing plate,

tanδ2 is tanδ at 80°C of the adhesive film for polarizing plates).

The polarizing plate of the present invention may include the adhesive film for the polarizing plate of the present invention.

The optical display device of the present invention may include the adhesive film for the polarizing plate of the present invention or the polarizing plate of the present invention.

The present invention provides a pressure-sensitive adhesive film for a polarizing plate capable of suppressing the pressure of the pressure-sensitive adhesive film due to solid particles during processing, cutting, packaging and/or storage of the pressure-sensitive adhesive film and/or recovering the pressure formed by the high-speed particles at a high speed. Did.

The present invention provides a pressure-sensitive adhesive film for a polarizing plate capable of suppressing pressing of the adhesive film due to solid particles during processing, cutting, packaging, and/or storage and/or recovering pressing formed by solid particles at a high speed. .

The present invention provides a pressure-sensitive adhesive film for a polarizing plate having an excellent light leakage suppression effect by alleviating the shrinkage of the polarizer at high temperature.

The present invention provides an adhesive film for a polarizing plate having excellent durability at high temperature or high temperature and high humidity, and having excellent corrosion inhibitory effect and rework property upon adhesion to a metal adherend containing an ITO film.

The present invention will be described in detail with reference to the accompanying embodiments so that those skilled in the art to which the present invention pertains can easily practice. The present invention can be implemented in many different forms and is not limited to the embodiments described herein.

In the present specification, “adhesive film for polarizing plate” and “adhesive composition for polarizing plate” may be referred to as “adhesive film” and “adhesive composition”, respectively.

As used herein, "(meth)acrylic" means acrylic and/or methacryl.

Hereinafter, an adhesive film for a polarizing plate according to an embodiment of the present invention will be described.

The adhesive film for polarizing plates of this embodiment includes (meth)acrylate having an alkyl group having 4 to 8 carbon atoms; (Meth)acrylate having a hydroxyl group; And a (meth)acrylic copolymer of a monomer mixture comprising at least one of a (meth)acrylate having an alkyl group having 1 to 3 carbon atoms and a (meth)acrylic monomer having an amide group. Can satisfy:

<Equation 1>

0.20 ≤ tanδ2 ≤ 0.40

<Equation 2>

tanδ2-tanδ1 ≤ 0.04

(In Equations 1 and 2, tanδ1 is tanδ at 23°C of the adhesive film for the polarizing plate,

tanδ2 is tanδ at 80°C of the adhesive film for polarizing plates).

The adhesive film for polarizing plates satisfies Equation 1 and Equation 2 and includes the (meth)acrylic copolymer, thereby suppressing pressing of the adhesive film due to solid particles during processing, cutting, packaging, and/or storage, and/or The pressing formed by the solid particles can be quickly recovered, and warpage due to shrinkage of the polarizing plate at high temperature can be suppressed. Even if the expression (1) is satisfied, the adhesive film having the value of the expression (2) outside the scope of the present invention does not have an effect of suppressing warpage due to shrinkage of the polarizing plate at high temperature, or it is slow to restrain or suppress the pressing of the adhesive film. The workability and the like of the product fell. In one embodiment, the adhesive film may have a dent value of 18 μm or less, for example 9 μm or less, for example 8 μm or less, by satisfying the values of Equations 1 and 2 above. In the above range, there is no pressing of the adhesive film or the degree to which the pressing occurs is weak, and thus can be used for the polarizing plate. The dent means the pressing value of the adhesive film.

Preferably, in the adhesive film, tanδ2 may be 0.21 to 0.38, more preferably tanδ2 may be 0.23 to 0.35. Preferably, the value of the formula 2 tanδ2-tanδ1 may be -0.20 to 0.02. tanδ1 may be 0.10 to 0.50, preferably 0.15 to 0.45, and more preferably 0.18 to 0.45. In the above range, it is possible to reach the values of Equation 1 and Equation 2.

In one embodiment, the adhesive film may satisfy Equation 3 below:

<Equation 3>

tanδ2 / tanδ1 <1.1

(In the formula 3, tanδ1 is tanδ at 23 ℃ of the adhesive film for the polarizing plate,

tanδ2 is tanδ at 80°C of the adhesive film for polarizing plates).

The adhesive film may suppress warpage due to shrinkage of the polarizing plate at a high temperature in the adhesive film that does not contain a carboxylic acid group by satisfying Equation 3, and may suppress the pressing of the adhesive film and restore the pressing. Preferably, the value of the formula 3 tanδ2 / tanδ1 (the ratio of tanδ2 to tanδ1) may be 0.50 to 1.05.

The adhesive film includes (meth)acrylate having an alkyl group having 4 to 8 carbon atoms; (Meth)acrylate having a hydroxyl group; And a (meth)acrylic copolymer and a curing agent of a monomer mixture comprising at least one of a (meth)acrylate having an alkyl group having 1 to 3 carbon atoms and a (meth)acrylic monomer having an amide group, and a curing agent. Can be.

The (meth)acrylate having an alkyl group having 4 to 8 carbon atoms forms a matrix of the adhesive film to increase the mechanical strength of the adhesive film and to ensure that other components in the monomer mixture are included in an appropriate content to the values of Equations 1 and 2 above. Can be reached. For example, (meth)acrylate having an alkyl group having 4 to 8 carbon atoms is a non-hydroxyl monomer having no hydroxyl group, n-butyl (meth)acrylate, t-butyl (meth)acrylate, iso-butyl (Meth)acrylate, pentyl (meth)acrylate, hexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, heptyl (meth)acrylate, octyl (meth)acrylate, iso-octyl (meth) Acrylate, but is not limited thereto. These may be included alone or in combination of two or more.

In one embodiment, among the (meth)acrylates having an alkyl group having 4 to 8 carbon atoms, the homopolymer has a glass transition temperature of -45°C or lower, and preferably (meth)acrylate having -70°C to -45°C. can do. In the above range, it is possible to reach the values of Equations 1 and 2 together with other components in the monomer mixture. For example, it may include one or more of n-butyl acrylate, 2-ethylhexyl acrylate, and n-hexyl acrylate, but is not limited thereto.

The (meth)acrylate having an alkyl group having 4 to 8 carbon atoms may be included at 40 mol% to 78 mol%, preferably 43 mol% to 78 mol% in the monomer mixture. In the above range, it is possible to maintain the mechanical strength of the adhesive film and reach the values of Equations 1 and 2.

The (meth)acrylate having a hydroxyl group can increase the adhesive strength of the adhesive film by reacting with a curing agent. The (meth)acrylate having a hydroxyl group may include (meth)acrylate having an alkyl group having 1 to 20 carbon atoms having at least one hydroxyl group. For example, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 6- It may include one or more of hydroxyhexyl (meth) acrylate, 1-chloro-2-hydroxypropyl (meth) acrylate. These may be included alone or in combination of two or more.

The (meth)acrylate having a hydroxyl group is 0.1 mol% to 20 mol%, 0.1 mol% to 15 mol%, preferably 1 mol% to 10 mol%, more preferably 1 mol% to 5 mol% in the monomer mixture It can be included as In the above range, it is possible to maintain the mechanical strength of the adhesive film and reach the values of Equations 1 and 2.

The monomer mixture may include at least one of (meth)acrylate having an alkyl group having 1 to 3 carbon atoms and (meth)acrylic monomer having an amide group as 10 to 40 mol% in the monomer mixture. Therefore, the pressure-sensitive adhesive film can reach the values of Equation and Equation 2.

In one embodiment, the monomer mixture may include a (meth)acrylate having an alkyl group having 1 to 3 carbon atoms and not a (meth)acrylic monomer having an amide group. In other embodiments, the monomer mixture may include a (meth)acrylic monomer having an amide group and no (meth)acrylate having an alkyl group having 1 to 3 carbon atoms. In another embodiment, it may include both a (meth)acrylate having an alkyl group having 1 to 3 carbon atoms and a (meth)acrylic monomer having an amide group.

Preferably, at least one of a (meth)acrylate having an alkyl group having 1 to 3 carbon atoms and a (meth)acrylic monomer having an amide group, the homopolymer may include a monomer having a glass transition temperature of 5°C to 150°C. . In the above range, the values of Equations 1 and 2 can be reached and the durability of the adhesive film can be increased.

The (meth)acrylate having an alkyl group having 1 to 3 carbon atoms may include, but is not limited to, one or more of methyl (meth)acrylate, ethyl (meth)acrylate, and propyl (meth)acrylate. Preferably, the monomer having a glass transition temperature of 5°C to 50°C of the homopolymer among (meth)acrylates having an alkyl group having 1 to 3 carbon atoms may be included. In the above range, the values of Equations 1 and 2 can be reached and the durability of the adhesive film can be increased.

The (meth)acrylate having an alkyl group having 1 to 3 carbon atoms may be included in 0 to 40 mol%, for example, 1 to 40 mol%, 5 to 40 mol%, in the monomer mixture. In the above range, the values of Equations 1 and 2 can be reached and the durability of the adhesive film can be increased.

The (meth)acrylic monomer having an amide group may include, but is not limited to, one or more of a (meth)acrylic monomer containing a (meth)acrylic monomer containing a (meth)acryloyl morpholine or the like (meth)acrylamide. Preferably, the (meth)acrylic monomer having an amide group may include a monomer having a glass transition temperature of 100°C to 200°C of the homopolymer. Preferably, a (meth)acryloyl morpholine or the like and a morpholine group-containing (meth)acrylic monomer may be included. In the above range, the values of Equations 1 and 2 can be reached and the durability of the adhesive film can be increased.

The (meth)acrylic monomer having an amide group is 0 mol% to 40 mol% in the monomer mixture, for example 1 mol% to 40 mol%, 1 mol% to 20 mol%, for example 1 mol% to 15 mol%, For example, it may be included in 5 mol% to 15 mol%. In the above range, the values of Equations 1 and 2 can be reached and the durability of the adhesive film can be increased.

The monomer mixture may further include a (meth)acrylic monomer having a tertiary amine group. The (meth)acrylic monomer having a tertiary amine group can improve the polymerization rate of the (meth)acrylic copolymer and increase the aging rate of the adhesive film.

The (meth)acrylic monomer having a tertiary amine group may include a (meth)acrylate having a tertiary amine group-containing alkyl group having 1 to 5 carbon atoms. For example, it may contain dialkylamino alkyl (meth)acrylate, dimethylaminoethyl (meth)acrylate, dimethylaminopropyl (meth)acrylate, dimethylaminobutyl (meth)acrylate, diethylamino It may include one or more of ethyl (meth) acrylate, diethyl aminopropyl (meth) acrylate, diethyl aminobutyl (meth) acrylate, dibutyl amino ethyl (meth) acrylate.

The (meth)acrylic monomer having a tertiary amine group may include 0 mol% to 15 mol%, 0.001 mol% to 15 mol%, specifically 0.01 mol% to 10 mol%, specifically 0.01 mol% to 1 mol% in the monomer mixture. In the above range, the aging rate at room temperature of the pressure-sensitive adhesive composition for a polarizing plate or a dried product thereof may be increased, and a curing reaction rate may be increased.

The monomer mixture may include at least one of (meth)acrylate having an alicyclic group and (meth)acrylate having an aromatic group. The (meth)acrylate having an alicyclic group and the (meth)acrylate having an aromatic group can provide a light leakage improvement effect for the adhesive film.

At least one of (meth)acrylate having an alicyclic group and (meth)acrylate having an aromatic group is 0 mol% to 20 mol% in the monomer mixture, for example 0.001 mol% to 20 mol%, for example 5 mol% to 20 mol %, for example, 10 mol% to 15 mol%. Within this range, light leakage can be improved.

The (meth)acrylic monomer having an alicyclic group is a (meth)acrylate having a monocyclic or heterocyclic group having 5 to 20 carbon atoms, cyclohexyl (meth)acrylate, isobornyl (meth)acrylate, and dicy Clofentanil (meth) acrylate, methyl cyclohexyl (meth) acrylate, and may include one or more of dicyclopentenyl (meth) acrylate. These may be included alone or in combination of two or more. Preferably, one or more of cyclohexyl (meth)acrylate and isobornyl (meth)acrylate may be included.

The (meth)acrylic monomer having an aromatic group may include (meth)acrylate having an aryl group having 6 to 20 carbon atoms or an arylalkyl group having 7 to 20 carbon atoms. Specifically, the (meth)acrylic monomer having an aromatic group may include benzyl (meth)acrylate and the like, but is not limited thereto.

The monomer mixture does not contain a (meth)acrylic monomer having a carboxylic acid group. The adhesive film can include a non-carboxylic acid-based (meth)acrylic polymer to obtain a corrosion prevention effect on a metal adherend. The (meth)acrylic copolymer may have an acid value of 5 mgKOH/g or less, and more specifically 1 mgKOH/g or less. Within the above range, it is possible to implement an anti-corrosion inhibitory effect directly or indirectly on the adherend.

The monomer mixture may not contain (meth)acrylate having a long chain alkyl group. When the (meth)acrylate having a long chain alkyl group is included, the effect of the present invention cannot be obtained. The "(meth)acrylate having a long chain alkyl group" may mean a (meth)acrylate having an alkyl group having 10 to 25 carbon atoms.

The (meth)acrylic copolymer may have a glass transition temperature of -30°C to -10°C, preferably -25°C to -10°C, more preferably -22°C to -13°C. In the above range, it is possible to lower the dent and suppress warpage.

The (meth)acrylic copolymer has a weight average molecular weight of 500,000 g/mol to 1.5 million g/mol, preferably 500,000 g/mol to 1 million g/mol, more preferably 700,000 g/mol to 1 million g/mol. In the above range, it is possible to lower the dent and suppress warpage.

The (meth)acrylic copolymer can be prepared by polymerizing a monomer mixture by a conventional polymerization method. The polymerization method may include conventional methods known to those skilled in the art. For example, the (meth)acrylic copolymer can be prepared by adding an initiator to the monomer mixture, followed by conventional copolymer polymerization such as suspension polymerization, emulsion polymerization, solution polymerization, and the like. The polymerization temperature may be 65°C to 70°C, and the polymerization time may be 6 hours to 8 hours. The initiator is an azo-based polymerization initiator; And/or peroxides such as benzoyl peroxide or acetyl peroxide.

The curing agent may react with a (meth)acrylic copolymer to provide adhesion. The curing agent may include at least one of a heat curing agent and a photo curing agent. The curing agent may be included in 0.1 parts by weight to 5.0 parts by weight, preferably 0.1 parts by weight to 2.5 parts by weight based on 100 parts by weight of the (meth)acrylic copolymer. In the above range, the pressure-sensitive adhesive composition can be crosslinked to give an adhesive effect, and to prevent transparency degradation due to excessive use.

The thermosetting agent may include at least one of an isocyanate curing agent, a metal chelate curing agent, an epoxy curing agent, an aziridine curing agent, an amine curing agent, and a thermal polymerization initiator. Preferably, at least one of an isocyanate-based curing agent and a metal chelate-based curing agent may be included. These may be included alone or in combination of two or more.

The isocyanate-based curing agent is not particularly limited as an isocyanate curing agent of bifunctional or higher, preferably bifunctional to 6functional, xylene diisocyanate (XDI), 4,4'-methylenebis (phenylisocyanate) including m-xylene diisocyanate and the like. It may include one or more of methylene bis (phenyl isocyanate) (MDI), naphthalene diisocyanate, tolylene diisocyanate, hexamethylene diisocyanate, and isophorone diisocyanate.

The metal chelate curing agent may include a coordination compound of a polyvalent metal such as aluminum. For example, the metal chelate-based curing agent may include aluminum chelating compounds such as trisethyl acetoacetate aluminum, ethyl acetoacetate aluminum diisopropylate, and trisacetylacetonate aluminum.

The thermal polymerization initiator may include one or more of an azo-based compound, a peroxide-based compound, or a redox-based compound. For example, examples of the peroxide-based compound include inorganic peroxides such as potassium peroxide, ammonium persulfate or hydrogen peroxide; Or diacyl peroxide, peroxy dicarbonate, peroxy ester, tetramethylbutylperoxy neodecanoate, bis(4-butylcyclohexyl)peroxydicarbonate, di(2-ethylhexyl)peroxy carbonate, butylper Oxy neodecanoate, dipropyl peroxy dicarbonate, diisopropyl peroxy dicarbonate, diethoxyethyl peroxy dicarbonate, diethoxyhexyl peroxy dicarbonate, hexyl peroxy dicarbonate, dimethoxybutyl peroxy dicarbonate , Bis(3-methoxy-3-methoxybutyl) peroxy dicarbonate, dibutyl peroxy dicarbonate, dicetyl peroxy dicarbonate, dimyristyl peroxy dicarbonate, 1,1 ,3,3-tetramethylbutyl peroxypivalate, hexyl peroxy pivalate, butyl peroxy pivalate, trimethyl hexanoyl peroxide, dimethyl hydroxybutyl peroxyneodecanoate, amyl peroxyneode Canoate, butyl peroxyneodecanoate, t-butylperoxy neoheptanoate, amylperoxy pivalate, t-butylperoxy pivalate, t-amyl peroxy-2-ethylhexanoate , Organic peroxides such as lauryl peroxide, dilauuroyl peroxide, didecanoyl peroxide, benzoyl peroxide or dibenzoyl peroxide.

Preferably, the thermosetting agent may be included in 0.1 parts by weight to 5.0 parts by weight, preferably 0.1 parts by weight to 0.5 parts by weight based on 100 parts by weight of the (meth)acrylic copolymer. In the above range, the pressure-sensitive adhesive composition can be crosslinked to give an adhesive effect, and to prevent transparency degradation due to excessive use.

The photocuring agent may include at least one of a bifunctional to hexafunctional (meth)acrylate and a photoinitiator.

Bifunctional to hexafunctional (meth)acrylates include 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate, and polyethylene glycol di (Meth)acrylate, neopentylglycol adipate di(meth)acrylate, dicyclopentanyl di(meth)acrylate, caprolactone modified dicyclopentenyl di(meth)acrylate, ethylene Oxide modified di(meth)acrylate, di(meth)acryloxyethyl isocyanurate, allylated cyclohexyl di(meth)acrylate, tricyclodecanedimethanol (meth)acrylate, dimethylol dicyclopentane di (Meth)acrylate, ethylene oxide-modified hexahydrophthalic acid di(meth)acrylate, tricyclodecane dimethanol (meth)acrylate, neopentyl glycol-modified trimethylpropane di(meth)acrylate, adamantane Difunctional acrylates or bifunctional acrylates such as 9,9-bis[4-(2-acryloyloxyethoxy)phenyl]fluorene; Trimethylolpropane tri(meth)acrylate, dipentaerythritol tri(meth)acrylate, propionic acid-modified dipentaerythritol tri(meth)acrylate, pentaerythritol tri(meth)acrylate, propylene oxide Trifunctional acrylates such as modified trimethylolpropane tri(meth)acrylate, trifunctional urethane (meth)acrylate or tris(meth)acryloxyethyl isocyanurate; Tetrafunctional acrylates such as diglycerin tetra(meth)acrylate or pentaerythritoltetra(meth)acrylate; 5-functional acrylates such as dipentaerythritol penta(meth)acrylate; And dipentaerythritol hexa(meth)acrylate, caprolactone modified dipentaerythritol hexa(meth)acrylate or urethane(meth)acrylate (ex. isocyanate monomer and trimethylolpropane tri(meth)acrylate) It may contain one or more of hexafunctional acrylates such as reactants.

The bifunctional to hexafunctional (meth)acrylate may be included in 0.1 parts by weight to 5.0 parts by weight, preferably 0.1 parts by weight to 1.0 parts by weight based on 100 parts by weight of the (meth)acrylic copolymer. In the above range, the pressure-sensitive adhesive composition can be crosslinked to give an adhesive effect, and to prevent transparency degradation due to excessive use.

Any photoinitiator can be used as long as it can induce a curing reaction by generating radicals by light irradiation. For example, a benzoin-based, hydroxy-ketone-based, amino-ketone-based or phosphine oxide-based photoinitiator can be used.

The photoinitiator may be included in an amount of 0.1 parts by weight to 5.0 parts by weight, preferably 0.1 parts by weight to 2.0 parts by weight based on 100 parts by weight of the (meth)acrylic copolymer. In the above range, the pressure-sensitive adhesive composition can be crosslinked to give an adhesive effect, and to prevent transparency degradation due to excessive use.

The pressure-sensitive adhesive composition may include a solvent. The solvent improves the coating properties of the pressure-sensitive adhesive composition and can inhibit the self-curing reaction of the pressure-sensitive adhesive composition. Solvents can be used conventional solvents known to those skilled in the art. For example, the solvent may include one or more of methyl ethyl ketone, ethyl acetate, and toluene.

The pressure-sensitive adhesive composition may further include at least one of a silane coupling agent, a reworking agent, a curing catalyst, an antistatic agent, and a curing catalyst.

The silane coupling agent can implement an adhesive film having high adhesion to an adherend such as glass. Silane coupling agents can include conventional silane coupling agents known to those skilled in the art. For example, the silane coupling agent has an epoxy structure such as 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, and 2-(3,4-epoxycyclohexyl)ethyl trimethoxysilane. A silicon compound having; Polymerizable unsaturated group-containing silicon compounds such as vinyl trimethoxysilane, vinyl triethoxysilane, and (meth)acryloxypropyl trimethoxysilane; Amino group-containing silicon compounds such as 3-aminopropyl trimethoxysilane, N-(2-aminoethyl)-3-aminopropyl trimethoxysilane, and N-(2-aminoethyl)-3-aminopropyl methyl dimethoxysilane ; And 3-chloro propyl trimethoxysilane and the like may include one or more selected from the group consisting of, but is not limited to these.

The silane coupling agent may be included in an amount of 0.001 part by weight to 5 parts by weight, and specifically 0.001 part by weight to 3 parts by weight with respect to 100 parts by weight of the (meth)acrylic copolymer. Within the above range, durability reliability is excellent, and changes in components and properties with time may be small.

The rework agent increases the rework property of the adhesive film, and may include a polysiloxane oligomer or a mixture containing the same. The rework agent may be included in an amount of 0.001 parts by weight to 5 parts by weight, specifically 0.005 parts by weight to 1 part by weight based on 100 parts by weight of the (meth)acrylic copolymer. Within the above range, rework property can be enhanced without affecting the physical properties of the adhesive film for polarizing plates.

The antistatic agent suppresses the generation of static electricity during rework of the adhesive film, and may include a conventional antistatic agent. The antistatic agent may be included in an amount of 0.001 part by weight to 5 parts by weight, specifically 0.1 part by weight to 3 parts by weight with respect to 100 parts by weight of the (meth)acrylic copolymer. In the above range, it is possible to provide an antistatic function without affecting the physical properties of the adhesive film for a polarizing plate.

The curing catalyst may be a boron-based compound, such as a boron trifluoride complex, specifically an etherate of boron trifluoride, a tetrahydrofuran complex of boron trifluoride (BF ₃ -THF), Aniline complex of boron trifluoride (BF ₃ -Aniline), specifically BF ₃ ·O(CH ₃ ) ₂ (boron trifluoride dimethyl etherate), BF ₃ ·O(C ₂ H ₅ ) ₂ (boron trifluoride diethyl etherate); Phosphine compounds, such as triphenylphosphine, tributylphosphine, tri(p-methylphenyl)phosphine, tri(nonylphenyl)phosphine, triphenylphosphine/triphenylborate, tetraphenylborate, etc.; Secondary amine or tertiary amine compounds such as triethylamine, benzyldiethylamine or alpha-tertiary amine compounds such as benzyldimethylamine (eg KH-30, Kukdo); Imidazole compounds such as 2-methylimidazole, 2-phenylimidazole, or 2-phenyl-4-methylimidazole; Sulfonic acid compounds such as paratoluenesulfonic acid, benzenedodecylsulfonic acid, naphthalenesulfonic acid, naphthalene disulfonic acid, methanesulfonic acid, methanedisulfonic acid, phenolsulfonic acid and the like. The curing catalyst may be included in an amount of 0.01 to 5 parts by weight, specifically 0.05 to 2 parts by weight based on 100 parts by weight of the (meth)acrylic copolymer. In the above range, there is an effect of reducing the curing speed.

The pressure-sensitive adhesive composition may further include a conventional additive. The additive may include a UV absorber, antioxidant, tackifying resin, plasticizer, and the like. The additive may be included in an amount of 0.001 part by weight to 5 parts by weight, specifically 0.01 part by weight to 1 part by weight based on 100 parts by weight of the (meth)acrylic copolymer. In the above range, an additive effect can be obtained without affecting the physical properties of the adhesive film for polarizing plates.

The pressure-sensitive adhesive composition may have a viscosity of 1,000 cPs to 4,000 cPs at 25°C. In the above range, the thickness of the adhesive film can be easily controlled, there is no stain on the adhesive film, and the coated surface may have a uniform effect.

The adhesive film is optically transparent and can be used in an optical display device. Specifically, the pressure-sensitive adhesive film may have a light transmittance of 85% or more and more specifically 85% to 95% at a wavelength of 380 nm to 780 nm.

The adhesive film may have a thickness of 100 μm or less, specifically 5 μm to 50 μm. In the above range, it can be used in an optical display device.

The pressure-sensitive adhesive film may be prepared by coating and drying the pressure-sensitive adhesive composition for a polarizing plate at a predetermined thickness, followed by aging at a constant temperature and humidity of 25°C to 35°C and a relative humidity of 30% to 60%, but is not limited thereto.

Hereinafter, a polarizing plate and an optical display device according to an embodiment of the present invention will be described.

The polarizing plate of the present invention may include an adhesive film for a polarizing plate according to embodiments of the present invention. The polarizing plate of the present invention may be prepared by adhering an adhesive film for a polarizing plate according to embodiments of the present invention to one side of the polarizing plate or coating the adhesive composition for the polarizing plate to a predetermined thickness on one side of the polarizing plate and then aging.

The optical display device of the present invention may include the adhesive film of the present invention or the polarizing plate of the present invention. The optical display device may include a liquid crystal display device and an organic light emitting display device, but is not limited thereto. In addition, the optical display device of the present invention may also include a flexible device.

The polarizing plate may include a polarizer, an optical film formed on at least one surface of the polarizer, and an adhesive film formed on at least one surface of the optical film. The polarizer and the optical film are according to conventional contents known to those skilled in the art. The polarizing plate may have a thickness of 25 μm to 100 μm, specifically 50 μm to 85 μm. In the above range, it can be used in an optical display device. The polarizing plate may include a polarizer, an optical film formed on at least one surface of the polarizer, and an adhesive film formed on the optical film. The optical film is an optically transparent resin film, and may include a cellulose-based film including triacetyl cellulose, a polyester film including polyethylene terephthalate, a polycarbonate film, an acrylic film, a cycloolefin polymer film, and the like.

The liquid crystal display device is not particularly limited, but may include a liquid crystal display device including IPS liquid crystal.

Hereinafter, the configuration and operation of the present invention will be described in more detail through preferred embodiments of the present invention. However, this is provided as a preferred example of the present invention and cannot be interpreted as limiting the present invention by any means.

Manufacturing example 1: (meth) acrylic Preparation of copolymer

Ethyl acetate was added to a 1 L reactor equipped with a cooling device so that nitrogen gas was refluxed and temperature control was easy. n-butyl acrylate (BA) 66.975 mol%, methyl acrylate (MA) 20 mol%, acryloyl morpholine (ACMO) 10 mol%, 4-hydroxybutyl acrylate (4-HBA) 3 mol%, dimethylaminoethyl 100 parts by weight of the monomer mixture containing 0.025 mol% of acrylate (DMAEA) was added to the reactor. Then, a mixture of ethyl acetate and methyl ethyl ketone was added to the reactor. In order to remove oxygen from the monomer mixture, nitrogen gas was added for 30 minutes to replace the reactor, and the temperature inside the reactor was maintained at 65°C. After uniformly stirring the monomer mixture, 0.06 parts by weight of V601 (dimethyl 2,2'-azobis(2-methylpropiotate) was added as an initiator and reacted for 4 hours.The temperature inside the reactor was raised to 65°C and the initiator was After further reacting at 70° C. for 2 hours, the mixture was cooled and methyl ethyl ketone was added to prepare a 25% by weight (meth)acrylic copolymer solution.

Manufacturing example 2 to Manufacturing example 13: ( Met ) Preparation of acrylic copolymer

In Preparation Example 1 (meth) acrylic copolymer was prepared in the same manner, except that the type and content of the monomer in the monomer mixture was changed as shown in Table 1 below. In the preparation example 10 and the preparation example 11, polymerization time was different.

Manufacturing example BA MA CHA IBXA BzA ACMO 4-HBA AA DMAEA Mw Tg One 66.975 20 - - - 10 3 - 0.025 836,678 -21 2 56.975 30 - - - 10 3 - 0.025 836,678 -13 3 75.475 - 11.5 - - 10 3 - 0.025 837,916 -22 4 66.975 5 - - 15 10 3 - 0.025 820,300 -20 5 56.975 40 - - - - 3 - 0.025 985,085 -22 6 54.975 27 15 - - - 3 - 0.025 931,651 -21 7 71.975 10 - 15 - - 3 - 0.025 929,688 -22 8 43.975 38 - - 15 - 3 - 0.025 864,196 -21 9 67 20 - - - 10 3 - - 855,273 -21 10 99 - - - - - One - - 1,600,000 -46 11 99 - - - - - One - - 727,652 -46 12 98.8 - - - - - One 0.2 - 745,061 -44 13 78.8 - - - 20 - 0.2 One - 739,346 -34

* In Table 1, BA: n-butyl acrylate, MA: methyl acrylate, CHA: cyclohexyl acrylate, IBXA: isobornyl acrylate, BzA: benzyl acrylate, ACMO: acryloyl morpholine, 4- HBA: 4-hydroxybutyl acrylate, AA: acrylic acid, DMAEA: dimethylaminoethyl acrylate,

* In Table 1, Mw: weight average molecular weight of acrylic copolymer (unit: g/mol), Tg: glass transition temperature of acrylic copolymer (unit: °C).

The specifications of the components used in the following examples and comparative examples are as follows.

(A) (meth) acrylic copolymer: (meth) acrylic copolymer of the production example of Table 1 above

(B) Hardener:

(B1) Isocyanate curing agent: xylene diisocyanate adduct of trimethylolpropane (TD-75, Soken, solid content 75 wt.%)

(B2) Metal chelate curing agent: M-12AT, solid content 10 wt.%

(B3) TMPTA: trimethylolpropane triacrylate

(B4) PETA: Pentaerythritol tetraacrylate

(B5) IRGACURE-184: 1-hydroxycyclohexylphenylketone

(B6) TPO: 2,4-trimethylbenzoyldiphenylphosphine oxide

(C) Curing catalyst: S accelerator (Soken)

(D) Silane coupling agent: A-50 (Soken)

(E) Antistatic agent: FC-4400 (3M, USA)

(F) Rework system: MAC-2101 (Soken)

Example One

0.025 parts by weight of the (B1) isocyanate curing agent was mixed with respect to 17 parts by weight of the (A1) (meth)acrylic copolymer. And, (C) curing catalyst (S accelerator, Soken), (D) silane coupling agent so that the curing catalyst is 0.01 parts by weight, silane coupling agent is 0.05 parts by weight, antistatic agent is 0.75 parts by weight, rework agent is 0.05 parts by weight A-50, Soken), (E) Antistatic agent (FC-4400, 3M, USA), (F) Rework agent (MAC-2101, Soken), respectively, mixed with methyl ethyl ketone as a solvent for the weight ratio of the methacrylic copolymer. Was mixed 4 times by weight to prepare an adhesive composition for a polarizing plate. The above content is based on solid content excluding solvent and the like.

Example 2 to Example 12

In Example 1, except for changing the type and/or content of the (meth)acrylic copolymer, the type and/or content of the curing agent as shown in Table 2 (unit: parts by weight), the pressure-sensitive adhesive for a polarizing plate The composition was prepared.

Comparative example 1 to Comparative example 4

In Example 1, except for changing the type and/or content of the (meth)acrylic copolymer, the type and/or content of the curing agent as shown in Table 2, an adhesive composition for a polarizing plate was prepared.

The composition of the pressure-sensitive adhesive composition of Examples and Comparative Examples is shown in Table 2 below.

(A) (B1) (B2) (B3) (B4) (B5) (B6) (C) (D) (E) (F) Manufacturing example Example 1 One 17 0.025 - - - - - 0.01 0.05 0.75 0.05 Example 2 2 17 0.025 - - - - - 0.01 0.05 0.75 0.05 Example 3 3 17 0.025 - - - - - 0.01 0.05 0.75 0.05 Example 4 4 17 0.025 - - - - - 0.01 0.05 0.75 0.05 Example 5 5 17 0.025 - - - - - 0.01 0.05 0.75 0.05 Example 6 6 17 0.025 - - - - - 0.01 0.05 0.75 0.05 Example 7 7 17 0.025 - - - - - 0.01 0.05 0.75 0.05 Example 8 8 17 0.025 - - - - - 0.01 0.05 0.75 0.05 Example 9 9 17 0.025 - - - - - 0.02 0.05 0.75 0.05 Example 10 2 17 0.025 - - - - - 0.01 0.05 0.75 0.05 Example 11 9 17 - - 0.15 - 0.1 0.1 - 0.05 0.75 0.05 Example 12 9 17 - - - 0.13 0.1 0.1 - 0.05 0.75 0.05 Comparative Example 1 10 17 0.02 - - - - - 0.01 0.05 0.75 - Comparative Example 2 11 17 0.028 0.08 - - - - 0.01 0.05 0.75 - Comparative Example 3 12 17 0.028 0.08 - - - - 0.01 0.05 0.75 - Comparative Example 4 13 17 0.028 0.08 - - - - 0.01 0.05 0.75 -

The physical properties of Table 3 below were evaluated for the pressure-sensitive adhesive composition for polarizing plates of Examples and Comparative Examples.

(1) Durability: The polyvinyl alcohol film was stretched 3 times at 60°C, adsorbed iodine, and then stretched 2.5 times in a boric acid aqueous solution at 40°C to prepare a polarizer (thickness: 23 μm). A triacetylcellulose film (thickness: 80 µm) was adhered to one surface of the prepared polarizer, and a triacetylcellulose film (thickness: 42 µm) was adhered to the other side of the polarizer to prepare a polarizing plate. The adhesive compositions of Examples and Comparative Examples were coated on a release film and dried at 90° C. for 4 minutes to remove the solvent and peeled from the release film to prepare an adhesive sheet. The prepared adhesive sheet is attached to one surface of a triacetyl cellulose film (thickness: 42 µm) of the prepared polarizing plate, and aged at 23° C. and 55% relative humidity at constant temperature and humidity for 24 hours to prepare a polarizing plate comprising an adhesive film. Did.

The prepared polarizing plate was cut into a rectangle with a size of horizontal x vertical (100 mm x 80 mm) (MD direction of polarizer x TD direction of polarizer). Then, the cut polarizing plate was adhered to the alkali-free glass plate (horizontal x vertical, 110 mm x 90 mm) through the adhesive sheet to prepare a specimen for durability evaluation. The specimen was autoclaved at 50°C for 1000 seconds to prepare a specimen in which a polarizing plate for durability evaluation was laminated on a glass plate. The obtained specimens were left at 85°C for 500 hours, or the specimens were left at 60°C and 95% relative humidity for 500 hours and evaluated according to the following criteria.

○: There is no excitation, drag, or air bubbles.

△: At least one of excitation, dragging, and bubble generation occurs finely, and the bubble size is less than 100 µm.

X: There are a lot of excitation, drag and bubbles, and the bubble size is more than 100㎛.

(2) Warp: The adhesive compositions of Examples and Comparative Examples were coated on a polyethylene terephthalate release film and dried at 90° C. for 4 minutes. The thickness of the obtained adhesive film was 25 μm. In the same manner as in (1), a polarizing plate in which triacetylcellulose films are adhered to both sides of the polarizer is prepared, and the prepared adhesive film is laminated on one side of the triacetylcellulose film (thickness:42µm) of the polarizing plate, and 23℃ and It was aged at 55% relative humidity for 24 hours. The polarizing plate having an adhesive film was cut into a rectangular size of length x width (210 mm x 25 mm, MD direction of the polarizer x TD direction of the polarizer), and then an alkali-free glass plate of length x width x thickness (210 mm x 25 mm x 0.5 mm) The adhesive film was adhered to the medium, and autoclaved at 50°C for 1000 seconds to prepare a specimen for bending measurement.

The obtained specimen was left in an oven at 85° C. for 72 hours, and then the specimen was removed from the oven and kept at room temperature for 2 hours. Then, the specimen was placed on a flat plane, and one end of the width of the specimen was fixed to the plane, and the distance between the other end of the width of the specimen and the plane was measured. After 5 measurements, the average value was recorded as the bending value.

(3) Dent: The pressure-sensitive adhesive compositions of Examples and Comparative Examples were coated on a polyethylene terephthalate release film (thickness: 38 μm), dried at 90° C. for 4 minutes, and an adhesive film having a thickness of 25 μm was prepared. In the same manner as in (1), a polarizing plate in which triacetylcellulose films are adhered to both sides of the polarizer is prepared, and the prepared adhesive film is laminated on one side of the triacetylcellulose film (thickness:42µm) of the polarizing plate, and 23℃ and It was aged for 24 hours at 55% relative humidity. The polarizing plate with the adhesive film was cut into length x width (50 mm x 10 mm). The cut polarizing plate was placed on a soda-lime glass plate (thickness: 1 mm) so that the release film faced to the top to prepare a specimen.

The dent was measured using a TA Instrument (TEXTURE ANALYZER TA.XT PLUS, load cell 5 kg, EKO Instruments) at 25°C. On the release film among the specimens, a spherical stainless tip (diameter 1 mm) of TA Instrument was placed at a height of 1 mm. After pressing the release film for 15 seconds with the spherical stainless tip under a load of 50 gf, the spherical stainless tip was removed from the release film and then left for the time shown in Table 4 below. Then, the release film was removed, and the traces formed on the adhesive film were observed with a 3D optical profiler to record the maximum depth of the traces.

(4)tanδ value: The adhesive film was evaluated by a temperature sweep test using Anton Paar Physica MCR300. The temperature was measured from 0°C to 120°C while increasing the temperature at a rate of 10°C/min. The adhesive film was evaluated to have a thickness of 600 to 1000 μm.

durability durability warp
(mm) Dent
(㎛) tanδ1 tanδ2 tanδ2-tanδ1 tanδ2/tanδ1 ＠
85℃ ＠
60℃/95%RH Example 1 O O 11.5 4.9 0.31 0.23 -0.08 0.74 Example 2 O O 13.0 3.8 0.39 0.23 -0.16 0.59 Example 3 O O 11.5 5.5 0.41 0.31 -0.10 0.75 Example 4 O O 12.5 5.9 0.33 0.32 -0.01 0.96 Example 5 O O 12.0 14.5 0.27 0.28 0.01 1.04 Example 6 O O 12.0 17.7 0.32 0.27 -0.05 0.85 Example 7 O O 11.5 12.3 0.34 0.31 -0.03 0.89 Example 8 O O 11.5 16.0 0.28 0.30 0.02 1.05 Example 9 O O 11.5 4.8 0.34 0.32 -0.02 0.94 Example 10 O O 11.5 4.5 0.30 0.23 -0.07 0.78 Example 11 O O 12.0 5.1 0.30 0.31 0.01 1.02 Example 12 O O 11.5 5.0 0.30 0.29 -0.01 0.95 Comparative Example 1 O O 13.5 19.5 0.17 0.24 0.07 1.39 Comparative Example 2 X X 13.5 24.5 0.44 0.49 0.05 1.11 Comparative Example 3 X X 14 23.5 0.42 0.48 0.06 1.14 Comparative Example 4 X X 13.5 24.5 0.42 0.48 0.06 1.14

* In Table 3, tanδ1 is the tanδ value of the adhesive film at 23℃, and tanδ2 is the tanδ value of the adhesive film at 80℃.

As shown in Table 3, the pressure-sensitive adhesive film for a polarizing plate of the present invention suppresses warpage and suppresses pressing of the pressure-sensitive adhesive film due to solid particles during processing, cutting, packaging, and storage of the pressure-sensitive adhesive film and/or solid particles. It is possible to implement an adhesive film capable of recovering the pressing formed by a high speed.

On the other hand, in Comparative Examples 1 to 4, which are outside the equations 1 and 2 of the present invention, the dent value was high.

Simple modifications or changes of the present invention can be easily carried out by those skilled in the art, and all such modifications or changes can be considered to be included in the scope of the present invention.

Claims (17)

(Meth)acrylate having an alkyl group having 4 to 8 carbon atoms; (Meth)acrylate having a hydroxyl group; And a (meth)acrylic copolymer of a monomer mixture comprising at least one of a (meth)acrylate having an alkyl group having 1 to 3 carbon atoms and a (meth)acrylic monomer having an amide group,
As a pressure-sensitive adhesive film for a polarizing plate satisfying the following formula 1 and formula 2,
<Equation 1>
0.20 ≤ tanδ2 ≤ 0.40
<Equation 2>
-0.02 ≤ tanδ2-tanδ1 ≤ 0.02
(In the formulas 1 and 2, tanδ1 is tanδ at 23°C of the adhesive film for the polarizing plate,
tanδ2 is tanδ at 80°C of the adhesive film for polarizing plates),
The (meth)acrylate having an alkyl group having 1 to 3 carbon atoms has a glass transition temperature of 5°C to 150°C of the homopolymer, and the (meth)acrylic monomer having the amide group contains a morpholine group-containing (meth)acrylic monomer. That is, the adhesive film for a polarizing plate.
delete The adhesive film for polarizing plates according to claim 1, wherein the adhesive film for polarizing plates satisfies Expression 3 below:
<Equation 3>
tanδ2 / tanδ1 <1.1
(In the formula 3, tanδ1 is tanδ at 23 ℃ of the adhesive film for the polarizing plate,
tanδ2 is tanδ at 80°C of the adhesive film for polarizing plates).
The adhesive film for polarizing plates according to claim 1, wherein the (meth)acrylate having an alkyl group having 4 to 8 carbon atoms is included in 40 to 78 mol% of the monomer mixture.
The method of claim 1, wherein at least one of the (meth) acrylate having a C 1 to C 3 alkyl group and a (meth) acrylic monomer having an amide group is included in 10 to 40 mol% of the monomer mixture. , Adhesive film for polarizing plates.
The method of claim 1, wherein the monomer mixture comprises a (meth)acrylate having an alkyl group having 1 to 3 carbon atoms and a (meth)acrylic monomer having the amide group, and having an alkyl group having 1 to 3 carbon atoms ( The total of the (meth)acrylic monomer having a meth)acrylate and the amide group is contained in 10 to 40 mol% of the monomer mixture, the adhesive film for polarizing plates.
delete The adhesive film for polarizing plates according to claim 1, wherein the monomer mixture does not contain a (meth)acrylate having a long chain alkyl group.
The adhesive film for polarizing plates according to claim 1, wherein the monomer mixture further comprises at least one of (meth)acrylate having an alicyclic group and (meth)acrylate having an aromatic group.
The adhesive film for polarizing plates according to claim 1, wherein the monomer mixture further comprises a (meth)acrylic monomer having a tertiary amine group.
The adhesive film for polarizing plates according to claim 1, wherein the (meth)acrylic copolymer has a glass transition temperature of -28°C to -10°C and a weight average molecular weight of 500,000 g/mol to 1.5 million g/mol.
The pressure-sensitive adhesive composition for a polarizing plate of claim 1, wherein the pressure-sensitive adhesive composition for a polarizing plate further comprises at least one of an isocyanate-based curing agent and a metal chelate-based curing agent.
The pressure-sensitive adhesive composition for a polarizing plate according to claim 1, wherein the pressure-sensitive adhesive composition for a polarizing plate for the polarizing plate further comprises at least one of a bifunctional to hexafunctional (meth)acrylate and a photoinitiator.
The adhesive film for polarizing plates according to claim 1, wherein the adhesive film for polarizing plates has a dent value of 18 μm or less.
(Meth)acrylate having an alkyl group having 4 to 8 carbon atoms; (Meth)acrylate having a hydroxyl group; And a (meth)acrylic copolymer of a monomer mixture containing at least one of a (meth)acrylate having an alkyl group having 1 to 3 carbon atoms and a (meth)acrylic monomer having an amide group.
The adhesive film for a polarizing plate formed of the pressure-sensitive adhesive composition for a polarizing plate satisfies Expression 1 and Expression 2 below,
<Equation 1>
0.20 ≤ tanδ2 ≤ 0.40
<Equation 2>
-0.02 ≤ tanδ2-tanδ1 ≤ 0.02
(In the formulas 1 and 2, tanδ1 is tanδ at 23°C of the adhesive film for the polarizing plate,
tanδ2 is tanδ at 80°C of the adhesive film for polarizing plates),
The (meth)acrylate having an alkyl group having 1 to 3 carbon atoms has a glass transition temperature of 5°C to 150°C of the homopolymer, and the (meth)acrylic monomer having the amide group contains a morpholine group-containing (meth)acrylic monomer. That is, the pressure-sensitive adhesive composition for a polarizing plate.
A polarizing plate comprising the adhesive film for a polarizing plate according to any one of claims 1, 3 to 6, and 8 to 14.
An optical display device comprising the polarizing plate of claim 16.