KR102550418B1 - Polarizing plate - Google Patents

Abstract

This application relates to a polarizing plate, a manufacturing method thereof, and a display device. The present application is a polarizing plate to which a non-solvent-type pressure-sensitive adhesive layer is applied, and it is possible to provide a polarizing plate including a non-solvent-type pressure-sensitive adhesive layer with physical properties equal to or superior to those of the solvent-type pressure-sensitive adhesive layer while solving problems caused by the application of the existing solvent-type pressure-sensitive adhesive layer. .

Description

Polarizer {POLARIZING PLATE}

This application relates to a polarizing plate, a manufacturing method thereof, and a display device.

Display devices such as LCD (Liquid Crystal Display) or OLED (Organic Light Emitting Device) include various optical films such as polarizers and retardation plates.

These optical films are usually applied to a display device with an adhesive layer or laminated to each other.

As the pressure-sensitive adhesive layer, a so-called solvent-type pressure-sensitive adhesive that is advantageous in realizing physical properties suitable for application of an optical film is applied.

Solvent-type pressure-sensitive adhesives require volatilization of the solvent during the formation of the pressure-sensitive adhesive, and a high-temperature process is required for volatilization or hardening of the pressure-sensitive adhesive. In this high-temperature process, deformation of optical films such as polarizing films may occur. Therefore, it is not possible to proceed with the formation process of the pressure-sensitive adhesive on the optical film, and a process of forming a pressure-sensitive adhesive layer separately in advance and then applying the pressure-sensitive adhesive to a polarizing plate or the like is generally used.

In addition, solvent-type adhesives also cause contamination problems in the process of volatilizing the solvent and quality issues due to generation of gas.

In order to solve this problem, a method of forming an adhesive by minimizing the use of a solvent may be considered, but it is a difficult task to implement the same physical properties as a solvent-type adhesive using a non-solvent-type adhesive.

The present application provides a polarizing plate, a manufacturing method thereof, and a display device. The present application is a polarizing plate to which a non-solvent-type pressure-sensitive adhesive layer is applied, and one is to provide a polarizing plate including a non-solvent-type pressure-sensitive adhesive layer with physical properties equal to or superior to those of the solvent-type pressure-sensitive adhesive layer while solving problems caused by the application of the existing solvent-type pressure-sensitive adhesive layer. for the purpose of

Among the physical properties mentioned in this specification, if the measurement temperature affects the result, the corresponding physical property is a physical property measured at room temperature unless otherwise specified. The term room temperature is a natural temperature that is not heated and cooled, and is usually a temperature within the range of about 10 ° C to 30 ° C or about 23 ° C or about 25 ° C. In addition, unless specifically stated otherwise in the present specification, the unit of temperature is °C.

Among the physical properties mentioned in this specification, when the measured pressure affects the result, the corresponding physical property is a physical property measured at normal pressure unless otherwise specified. The term normal pressure is a natural temperature that is not pressurized and reduced, and usually refers to about 1 atm.

This application relates to a polarizing plate, and the polarizing plate includes a polarizing film and an adhesive layer formed on at least one surface of the polarizing film. In the above, the pressure-sensitive adhesive layer may be formed by being directly attached to one surface of the polarizing film, or another component may exist between the polarizing film and the pressure-sensitive adhesive layer. As the other components in the above, a polarizer protective film, a cured resin layer, a hard coating layer, a retardation film, and/or an adhesive layer may be exemplified, but are not limited thereto.

In this specification, a polarizing film and a polarizing plate refer to different objects. That is, a polarizing film refers to a film itself exhibiting a polarizing function, and a polarizing plate refers to a laminate including at least one or more other functional elements together with the polarizing film. Examples of functional elements include the pressure-sensitive adhesive layer, the polarizer protective film, the cured resin layer, the hard coating layer, the retardation film, and/or the adhesive layer, but are not limited thereto.

The polarizing film is a functional element capable of extracting light vibrating in one direction from incident light. As the polarizing film, for example, a known absorption-type linear polarizing film can be used. As such a polarizing film, a so-called PVA (poly (vinyl alcohol))-based polarizing film in which an anisotropic dye such as iodine is adsorbed and/or oriented on a PVA (poly (vinyl alcohol))-based film can be exemplified. However, the polarizing film that can be applied in the present application is not limited to the above types.

The pressure-sensitive adhesive layer included in the polarizing plate of the present application may be a non-solvent-type pressure-sensitive adhesive layer. The term solvent-free pressure-sensitive adhesive layer means a pressure-sensitive adhesive layer of a solvent-free pressure-sensitive adhesive composition. As used herein, the term solvent-free pressure-sensitive adhesive composition is a pressure-sensitive adhesive composition that does not substantially contain a solvent (aqueous solvent and organic solvent). Accordingly, the content of the aqueous and organic solvents in the pressure-sensitive adhesive composition may be 1% by weight or less, 0.5% by weight or less, 0.1% by weight or less, or substantially 0% by weight. In addition, the term "solvent-free pressure-sensitive adhesive composition" refers to a pressure-sensitive adhesive layer containing the above solvent-free pressure-sensitive adhesive composition as it is or a cured product thereof.

In the present application, by applying a non-solvent-type pressure-sensitive adhesive layer, it is possible to solve the problems of the existing solvent-type pressure-sensitive adhesive layer, and to realize excellent physical properties beyond the solvent-type pressure-sensitive adhesive layer through control of its composition and/or formation method.

The non-solvent pressure-sensitive adhesive composition may contain at least a polymer component, a first curing agent, and a second curing agent.

A polymer component included in the pressure-sensitive adhesive composition may be a syrup component. The syrup component may include an oligomer or polymer component formed by polymerization of two or more monomers and a monomer component. This syrup component can, in one example, be formed by so-called partial polymerization. That is, when the monomer composition according to the desired composition is partially polymerized, some of the monomers are polymerized to form the oligomer or polymer, and the remaining monomers remain to form the syrup component. Therefore, the terms of a monomer unit such as a (meth)acrylate unit described below in the present specification refer to a monomer that exists in the form of the oligomer or polymer in the polymer component or a monomer that is not polymerized and is included in the syrup component. can mean

The polymer component may include an alkyl (meth)acrylate unit having an alkyl group having 4 to 20 carbon atoms. The number of carbon atoms of the alkyl group may be 16 or less, 12 or less, or 8 or less in another example, and the alkyl group may be straight or branched, and may be substituted or unsubstituted.

As said alkyl (meth)acrylate, for example, n-butyl (meth)acrylate, t-butyl (meth)acrylate, sec-butyl (meth)acrylate, pentyl (meth)acrylate, 2- Ethylbutyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, n-octyl (meth)acrylate, isooctyl (meth)acrylate, isononyl (meth)acrylate, lauryl (meth)acrylate And any one or two or more selected from the group consisting of tetradecyl (meth) acrylate may be applied.

These alkyl (meth)acrylates may be included in a proportion of about 40 to 99% by weight in the polymer component. In another example, the ratio is 45% by weight or more, 50% by weight or more, 55% by weight or more, 60% by weight or more, 65% by weight or more, 70% by weight or more, 75% by weight or more, or 80% by weight or more, or 95% by weight 90% by weight or less, 85% by weight or less, 80% by weight or less, 75% by weight or less, 70% by weight or less, or 65% by weight or less.

The polymer component may include, as an additional component, a monomer unit having a polar functional group. As the polar functional group in this monomer unit, a hydroxyl group or a carboxyl group is usually applied, but is not limited thereto.

As a monomer having a polar functional group, for example, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 6-hydroxyhexyl (meth)acrylate and/or hydroxyalkyl (meth)acrylate such as 8-hydroxyoctyl (meth)acrylate (wherein the alkyl group has 1 to 20, 1 to 16, 1 to 12, or 1 to 8 carbon atoms) or 1 to 4, and the alkyl group may be straight or branched, substituted or unsubstituted.); Alternatively, hydroxy polyalkylene glycol (meth)acrylates such as 2-hydroxy polyethylene glycol (meth)acrylate or 2-hydroxy polypropylene glycol (meth)acrylate, or acrylic acid may be used. It is not limited.

In one embodiment of the present application, the monomer unit having the polar functional group may be included in the polymer component in a ratio of about 1 to 40 parts by weight based on 100 parts by weight of the alkyl (meth)acrylate unit. The ratio may be about 5 parts by weight or more, about 10 parts by weight or more, or about 15 parts by weight or more, or about 35 parts by weight or less, about 30 parts by weight or less, about 25 parts by weight or less, or about 20 parts by weight or less in another example. there is.

In addition to the polymer component, a necessary monomer unit may be included.

For example, the polymer component may further include nitrogen-containing reactive monomer units. Examples of such nitrogen-containing reactive monomers include (meth)acrylamide, N,N-dimethyl (meth)acrylamide, N,N-diethyl (meth)acrylamide, N-isopropyl (meth)acrylamide, and N-methyl Ol (meth)acrylamide, diacetone (meth)acrylamide, N-vinylacetamide, N,N'-methylenebis (meth)acrylamide, N,N-dimethylaminopropyl (meth)acrylamide, N,N -Dimethylaminopropyl (meth)acrylamide, N-vinylpyrrolidone, N-vinylcaprolactam, or (meth)acryloylmorpholine may be exemplified by one or two or more, but is not limited thereto. Suitable monomers include, for example, (meth)acrylamide, N-alkyl (meth)acrylamide and/or N,N-dialkyl (meth)acrylamide and the like. Examples of the alkyl group include straight-chain, branched-chain or cyclic substituted or unsubstituted alkyl groups having 1 to 20 carbon atoms, 1 to 16 carbon atoms, 1 to 12 carbon atoms, 1 to 8 carbon atoms, or 1 to 4 carbon atoms.

The nitrogen-containing reactive monomer unit may be included in the polymer component in an amount of about 1 to 20 parts by weight based on 100 parts by weight of the alkyl (meth)acrylate unit. In another example, the ratio may be about 3 parts by weight or more, or about 5 parts by weight or more, or about 15 parts by weight or less, or about 10 parts by weight or less.

For example, the polymer component may further include a unit of a monomer represented by Formula 1 below.

[Formula 1]

In Formula 1, R is hydrogen or an alkyl group, and P is a monovalent substituent having a non-aromatic ring structure having 3 to 20 carbon atoms.

In the above, the alkyl group may be a linear, branched or cyclic substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, 1 to 16 carbon atoms, 1 to 12 carbon atoms, 1 to 8 carbon atoms, or 1 to 4 carbon atoms.

Meanwhile, P is a monovalent substituent of a non-aromatic ring structure having 3 to 20 carbon atoms, and may be, for example, a monovalent substituent derived from an aliphatic saturated or unsaturated hydrocarbon cyclic compound. The cyclic compound may have a monocyclic or polycyclic structure such as condensed or spiro. In another example, the number of carbon atoms in the ring structure may be 6 or more, 8 or more, 18 or less, 16 or less, 14 or less, or 12 or less. Examples of such substituents include isobornyl group, cyclohexyl group, norbornanyl group, norbornenyl group, dicyclopentadienyl group, ethynylcyclohexane group, A tinylcyclohexene group or an ethynyldecahydronaphthalene group may be applied, but is not limited thereto.

The monomer unit of Chemical Formula 1 may be included in the polymer component in an amount of about 1 to 60 parts by weight based on 100 parts by weight of the alkyl (meth)acrylate unit. In another example, the ratio is about 3 parts by weight or more, about 5 parts by weight or more, about 7 parts by weight or more, about 9 parts by weight or more, about 11 parts by weight or more, about 13 parts by weight or more, or about 15 parts by weight or more, About 55 parts by weight or less, about 50 parts by weight or less, about 45 parts by weight or less, about 40 parts by weight or less, about 35 parts by weight or less, about 30 parts by weight or less, about 25 parts by weight or less, or about 20 parts by weight or less. .

The polymer component may also further contain a unit of a monomer represented by the following formula (2).

[Formula 2]

In Formula 2, Q is hydrogen or an alkyl group, U is an alkylene group having 1 to 4 carbon atoms, m is a number within the range of 1 to 5, and Z is hydrogen, an alkyl group or an aryl group.

Examples of the alkyl group in Formula 2 include a straight-chain, branched-chain or cyclic substituted or unsubstituted alkyl group having 1 to 20 carbon atoms, 1 to 16 carbon atoms, 1 to 12 carbon atoms, 1 to 8 carbon atoms, or 1 to 4 carbon atoms. there is.

In addition, as the alkylene group, a straight-chain or branched chain substituted or unsubstituted alkylene group having 1 to 4 carbon atoms may be exemplified, and examples thereof may include a propylene group or an ethylene group.

In Formula 2, m may be 4 or less, 3 or less, 2 or less, or 2 or more.

Also, as the aryl group in Chemical Formula 2, an aryl group having 6 to 24 carbon atoms, 6 to 18 carbon atoms, or 6 to 12 carbon atoms may be exemplified.

The monomer unit of Chemical Formula 2 may be included in the polymer component in an amount of about 1 to 60 parts by weight based on 100 parts by weight of the alkyl (meth)acrylate unit. In another example, the ratio is about 3 parts by weight or more, about 5 parts by weight or more, about 7 parts by weight or more, about 9 parts by weight or more, about 11 parts by weight or more, about 13 parts by weight or more, or about 15 parts by weight or more, About 55 parts by weight or less, about 50 parts by weight or less, about 45 parts by weight or less, about 40 parts by weight or less, about 35 parts by weight or less, about 30 parts by weight or less, about 25 parts by weight or less, or about 20 parts by weight or less. .

The polymer component may further include a unit of a monomer represented by the following formula (3).

[Formula 3]

In Formula 3, R ₁ is hydrogen or an alkyl group, A represents alkylene, n represents an integer in the range of 0 to 3, Q represents a single bond, -O-, -S- or alkylene, and P represents represents an aromatic ring.

In Formula 3, a single bond means a case in which atomic groups on both sides are directly bonded without intervening separate atoms.

In Formula 3, R ₁ may be, for example, hydrogen or alkyl having 1 to 4 carbon atoms, or may be hydrogen, methyl or ethyl.

In Formula 3, A may be an alkylene having 1 to 12 or 1 to 8 carbon atoms, for example, methylene, ethylene, hexylene or octylene.

In Formula 3, n may be, for example, a number within the range of 0 to 2, or 0 or 1.

In Formula 3, Q may be a single bond, -O- or -S-.

In Formula 3, P is a substituent derived from an aromatic compound, for example, a functional group derived from an aromatic ring having 6 to 20 carbon atoms, 6 to 18 carbon atoms, or 6 to 12 carbon atoms, for example, phenyl, biphenyl, naphthyl or may be anthracenyl.

In Chemical Formula 3, the aromatic ring may be optionally substituted with one or more substituents, and specific examples of the substituent include halogen or alkyl, halogen or alkyl having 1 to 12 carbon atoms, chlorine, bromine, methyl, ethyl, propyl , butyl, nonyl or dodecyl, but is not limited thereto.

Specific examples of the compound of Formula 3 include phenoxy ethyl (meth)acrylate, benzyl (meth)acrylate, 2-phenylthio-1-ethyl (meth)acrylate, 6-(4,6-dibromo-2 -Isopropyl phenoxy)-1-hexyl (meth)acrylate, 6-(4,6-dibromo-2-sec-butyl phenoxy)-1-hexyl (meth)acrylate, 2,6-di Bromo-4-nonylphenyl (meth)acrylate, 2,6-dibromo-4-dodecyl phenyl (meth)acrylate, 2-(1-naphthyloxy)-1-ethyl (meth)acrylate , 2-(2-naphthyloxy)-1-ethyl (meth)acrylate, 6-(1-naphthyloxy)-1-hexyl (meth)acrylate, 6-(2-naphthyloxy)-1 -Hexyl (meth)acrylate, 8-(1-naphthyloxy)-1-octyl (meth)acrylate and 8-(2-naphthyloxy)-1-octyl (meth)acrylate or one or more of them. mixing, but is not limited thereto.

The monomer unit of Chemical Formula 3 may be included in the polymer component in an amount of about 1 to 60 parts by weight based on 100 parts by weight of the alkyl (meth)acrylate unit. In another example, the ratio is about 3 parts by weight or more, about 5 parts by weight or more, about 7 parts by weight or more, about 9 parts by weight or more, about 11 parts by weight or more, about 13 parts by weight or more, or about 15 parts by weight or more, About 55 parts by weight or less, about 50 parts by weight or less, about 45 parts by weight or less, about 40 parts by weight or less, about 35 parts by weight or less, about 30 parts by weight or less, about 25 parts by weight or less, or about 20 parts by weight or less. .

As the polymer component is implemented to have the above composition, physical properties equivalent to or higher than those of the solvent type may be realized while being non-solvent type.

The method for preparing the polymer component containing the above units is not particularly limited. For example, after mixing monomers in a desired ratio for the implementation of the above-described syrup component, the polymer component may be formed by appropriately partially polymerizing the monomers.

The method of carrying out the partial polymerization as described above is not particularly limited, and, for example, after applying an appropriate photoinitiator or thermal initiator, polymerization (eg, bulk polymerization) is performed under appropriate conditions in consideration of the desired monomer conversion rate. A polymeric component can be prepared.

The non-solvent type pressure-sensitive adhesive composition may include two types of curing agents together with the above polymer components.

In the above, as the first curing agent, a multifunctional acrylate having a molecular weight of 500 g/mol or less may be applied. The term multifunctional acrylate refers to a compound containing two or more acrylate functional groups such as a (meth)acryloyl group and/or a (meth)acryloyloxy group. At this time, the number of the acrylate functional group is, for example, 2 to 10, 2 to 9, 2 to 8, 2 to 7, 2 to 6, 2 to 5, 2 It may be present in numbers within the range of 2 to 4 or 2 to 3.

Examples of the acrylate compound include 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, neopentylglycol di(meth)acrylate, and hydroxypivalic acid. Neopentyl glycol di(meth)acrylate, dicyclopentanyl di(meth)acrylate, caprolactone-modified dicyclopentenyl di(meth)acrylate, ethylene oxide-modified phosphoric acid di(meth)acrylate, di(meth)acrylic acid Oxyethyl isocyanurate, allylated cyclohexyl di(meth)acrylate, tricyclodecanedimethanol di(meth)acrylate, dimethylol dicyclopentane di(meth)acrylate, ethylene oxide modified hexahydrophthalic acid di(meth) )Acrylate, neopentyl glycol-modified trimethylolpropane di(meth)acrylate, adamantane di(meth)acrylate, 9,9-bis[4-(2-acryloyloxyethoxy)phenyl]fluorene bifunctional types such as; Trimethylolpropane tri(meth)acrylate, dipentaerythritol tri(meth)acrylate, propionic acid-modified dipentaerythritol tri(meth)acrylate, pentaerythritol tri(meth)acrylate, propylene oxide-modified trimethylolpropane trifunctional types such as tri(meth)acrylate and tris(meth)acryloxyethyl isocyanurate; tetrafunctional types such as diglycerin tetra(meth)acrylate and pentaerythritol tetra(meth)acrylate; pentafunctional types such as propionic acid-modified dipentaerythritol penta(meth)acrylate; And one or two or more selected from the group consisting of hexafunctional types such as dipentaerythritol hexa(meth)acrylate, caprolactone-modified dipentaerythritol hexa(meth)acrylate, etc. may be used.

In one example, a component having a molecular weight of about 500 g/mol or less may be used as the multifunctional acrylate. The molecular weight is, in another example, about 450 g / mol or less, about 400 g / mol or less, about 350 g / mol or less, about 300 g / mol or less or about 250 g / mol or less, about 50 g / mol or more, about 55 g/mol or more, about 60 g/mol or more, about 65 g/mol or more, about 70 g/mol or more, about 75 g/mol or more, about 80 g/mol or more, about 85 g/mol or more, about 90 g/mol or more, about 95 g/mol or more, about 100 g/mol or more, about 110 g/mol or more, about 120 g/mol or more, about 130 g/mol or more, about 140 g/mol or more, about 150 g /mol or more, about 160 g/mol or more, about 170 g/mol or more, about 180 g/mol or more, about 190 g/mol or more, or about 200 g/mol or more.

In the present application, an aliphatic acyclic multifunctional acrylate may be applied as a multifunctional acrylate having the above molecular weight as the first curing agent, but is not limited thereto.

The first curing agent may be included in the pressure-sensitive adhesive composition in an amount of about 0.01 to 1 part by weight based on 100 parts by weight of the polymer component. In other examples, the ratio is about 0.9 parts by weight or less, about 0.8 parts by weight or less, about 0.7 parts by weight or less, about 0.6 parts by weight or less, about 0.5 parts by weight or less, about 0.4 parts by weight or less, about 0.3 parts by weight or less, about 0.2 parts by weight or less. It may be about 0.15 parts by weight or less, about 0.02 parts by weight or more, about 0.03 parts by weight or more, about 0.04 parts by weight or more, or about 0.05 parts by weight or more.

As the second curing agent, benzophenone (meth)acrylate, polyfunctional isocyanate compound and/or polyfunctional urethane acrylate can be applied. As the second curing agent, one or a mixture of two or more of the above can be applied.

Polyfunctional isocyanate compounds are compounds containing two or more isocyanate functional groups, examples of which include tolylene diisocyanate, xylene diisocyanate, diphenylmethane diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, tetra A diisocyanate such as methylxylene diisocyanate or naphthalene diisocyanate or a reaction product of one or more of the above diisocyanates and a polyol (eg, trimethylol propane) may be used.

As the urethane acrylate, a reaction product of a polyol, a polyfunctional isocyanate and a hydroxy group-containing (meth)acrylate or a reaction product of a polyfunctional isocyanate and a hydroxy group-containing (meth)acrylate can be applied. Accordingly, the urethane acrylate may include a polyol unit, a polyfunctional isocyanate unit, and a hydroxyl group-containing (meth)acrylate unit, or may include a polyfunctional isocyanate unit and a hydroxyl group-containing (meth)acrylate unit.

In the above, a diol may be applied as the polyol, and the diol is any one selected from low molecular weight diols, diols having a polyene skeleton, diols having a polyester skeleton, diols having a polyether skeleton, and diols having a polycarbonate skeleton, or Two or more may apply. Examples of the low molecular weight diol include ethylene glycol, propylene glycol, cyclohexanedimethanol, neopentyl glycol, 3-methyl-1,5-pentanediol and/or 1,6-hexanediol, and the like. Examples of the diol having a polybutadiene skeleton, a diol having a polyisoprene skeleton, a diol having a hydrogenated polybutadiene skeleton, and/or a diol having a hydrogenated polyisoprene skeleton may be exemplified. As the diol, an esterification reaction product of a diol component such as the low molecular weight diol or polycaprolactone diol and an acid component such as dicarboxylic acid or an anhydride thereof may be exemplified.

Examples of dicarboxylic acids or anhydrides thereof include adipic acid, succinic acid, phthalic acid, tetrahydrophthalic acid, hexahydrophthalic acid and/or terephthalic acid, and anhydrides thereof. In addition, polyethylene glycol and/or polypropylene glycol may be exemplified as the polyether diol, and bisphenol such as the low molecular weight diol or/and bisphenol A and carbonic acid such as ethylene carbonate and dibutyl carbonate ester may be used as the polycarbonate diol. Reactants of dialkyl esters and the like can be exemplified.

Diols having a hydrogenated polydiene skeleton may be used as the diol having a polyene skeleton, and examples thereof include compounds having a diol at the end of a polymer of monomers such as isoprene, 1,3-butadiene, and 1,3-pentadiene. and compounds having diols at the ends of polymers of these monomers.

Examples of the polyfunctional isocyanate include aliphatic diisocyanates such as hexamethylene diisocyanate, lysine methyl ester diisocyanate, 2,4,4-trimethylhexamethylene diisocyanate and/or dimer acid diisocyanate, isophorone diisocyanate, and 4 , 4'-methylenebis(cyclohexyl isocyanate) and/or diisocyanate alicyclic diisocyanates such as dimethylcyclohexane, tolylene diisocyanate, xylene diisocyanate and/or diphenylmethane-4,4'-diisocyanate, etc. Aromatic diisocyanates and the like can be used. In addition, as the polyfunctional isocyanate having three or more isocyanate groups, hexamethylene diisocyanate trimer, isophorone diisocyanate trimer, and the like can also be applied.

Examples of the hydroxy group-containing (meth)acrylate include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, and hydroxypentyl (meth)acrylate. hydroxyalkyl (meth)acrylates such as hydroxyhexyl (meth)acrylate, hydroxyoctyl (meth)acrylate, and/or mono- or di(meth)acrylates of trimethylolpropane, penta mono, di or tri(meth)acrylates of erythritol, mono, di or tri(meth)acrylates of ditrimethylolpropane and/or mono, di, tri, tetra or penta(meth)acrylates of dipentaerythritol A compound having a hydroxyl group and two or more (meta) acryloyl groups, such as a rate, and the like can be applied.

A method for preparing a desired urethane acrylate by applying the above components is known. For example, according to a known method, a polyol and a polyfunctional isocyanate are reacted to prepare an isocyanate group-containing compound, and this is reacted with a hydroxyl group-containing (meth)acrylate, or a polyol, polyfunctional isocyanate and a hydroxyl group-containing compound (meth ) The urethane acrylate may be prepared by simultaneously reacting acrylates or reacting polyfunctional isocyanate and hydroxy group-containing (meth)acrylate.

As the urethane acrylate, as an example, one having a number average molecular weight (Mn) in the range of 2,000 to 50,000 g/mol may be used, and bifunctional urethane acrylate, that is, a (meth)acryloyl group and a (meth)acrylic One containing two functional groups selected from royloxy groups may be used. The number average molecular weight is a value in terms of standard polystyrene measured by a gel permeation chromatograph (GPC) method.

The second curing agent may be included in the pressure-sensitive adhesive composition in an amount of about 0.1 to 5 parts by weight based on 100 parts by weight of the polymer component. The ratio may be about 4.5 parts by weight or less or about 4 parts by weight or less in another example.

Meanwhile, in the pressure-sensitive adhesive composition, the ratio (C2/C1) of the weight (C1) of the first curing agent and the weight (C2) of the second curing agent (C2/C1) may be, for example, in the range of about 1 to 100. In another example, the ratio (C2/C1) is about 2 or more, about 4 or more, about 6 or more, about 8 or more, about 10 or more, about 12 or more, about 14 or more, about 16 or more, or about 18 or more, or 95 or less. degree, 90 or less, 85 or less, 80 or less, 75 or less, 70 or less, 65 or less, 60 or less, 55 or less, 50 or less, 45 or less, or 40 or less.

The pressure-sensitive adhesive composition may further include necessary components in addition to the above components. For example, the pressure-sensitive adhesive composition may further include a radical initiator, for example, an optical radical initiator.

Examples of the radical initiator include benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin n-butyl ether, benzoin isobutyl ether, acetophenone, dimethylanino acetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxy-2-phenylacetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1one, 1-hydroxycyclohexylphenyl Ketone, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholino-propan-1-one, 4-(2-hydroxyethoxy)phenyl-2-(hydroxy-2-propyl ) ketone, benzophenone, p-phenylbenzophenone, 4,4'-diethylaminobenzophenone, dichlorobenzophenone, 2-methylanthraquinone, 2-ethylanthraquinone, 2-t-butylanthraquinone, 2-amino Anthraquinone, 2-methylthioxanthone, 2-ethylthioxanthone, 2-chlorothioxanthone, 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, benzyldimethylketal, acetophenone dimethylketal, p-Dimethylaminobenzoic acid ester, oligo[2-hydroxy-2-methyl-1-[4-(1-methylvinyl)phenyl]propanone] or 2,4,6-trimethylbenzoyl-diphenyl-phosphineoxide etc. can be used, but is not limited thereto.

The radical initiator may be included in an appropriate ratio in the pressure-sensitive adhesive composition, for example, in an amount of about 0.1 to 3 parts by weight based on 100 parts by weight of the polymer component.

The pressure-sensitive adhesive composition may further include a silane coupling agent. The silane coupling agent can improve adhesion and adhesion stability of the pressure-sensitive adhesive, improve heat resistance and moisture resistance, and improve adhesion reliability even when left unattended under harsh conditions for a long period of time. As the silane coupling agent, for example, gamma-glycidoxypropyl triethoxy silane, gamma-glycidoxypropyl trimethoxy silane, gamma-glycidoxypropyl methyldiethoxy silane, gamma-glycidoxypropyl tri Ethoxy silane, 3-mercaptopropyl trimethoxy silane, vinyltrimethoxysilane, vinyltriethoxy silane, gamma-methacryloxypropyl trimethoxy silane, gamma-methacryloxy propyl triethoxy silane, gamma- Aminopropyl trimethoxy silane, gamma-aminopropyl triethoxy silane, 3-isocyanato propyl triethoxy silane, gamma-acetoacetate propyl trimethoxy silane, gamma-acetoacetate propyl triethoxy silane, beta- Cyanoacetyl trimethoxy silane, beta-cyanoacetyl triethoxy silane, acetoxy aceto trimethoxy silane, etc. may be used, and one or a mixture of two or more of the above may be used. It is preferable to use a silane-based coupling agent having an acetoacetate group or beta-cyanoacetyl group, but is not limited thereto.

The silane coupling agent may be included in the pressure-sensitive adhesive composition in an appropriate ratio, for example, about 0.01 part by weight to about 5 parts by weight based on 100 parts by weight of the polymer component.

The pressure-sensitive adhesive composition may further contain an antioxidant, if necessary. As the antioxidant, for example, a hindered phenol-based compound, a sulfur-based antioxidant, a phenylacetic acid-based antioxidant, or a phosphorus-based antioxidant may be applied, but is not limited thereto.

The antioxidant may be included in an amount of about 0.01 part by weight to about 5 parts by weight or about 0.01 part by weight to about 1 part by weight based on 100 parts by weight of the polymer component in the pressure-sensitive adhesive composition.

The pressure-sensitive adhesive composition may further contain an antistatic agent. As an antistatic agent, an ionic compound is usually applied. As the ionic compound, for example, a metal salt or an organic salt may be used.

The antistatic agent may be included in an amount of about 0.01 to 10 parts by weight based on 100 parts by weight of the polymer component in the pressure-sensitive adhesive composition, and an appropriate ratio may be applied in consideration of desired conductivity.

The pressure-sensitive adhesive composition or the polymer component included therein may have, for example, a weight average molecular weight (Mw) within a range of about 500,000 to about 3,000,000 g/mol. The weight average molecular weight is a value in terms of standard polystyrene measured by GPC (Gel Permeation Chromatograph). In another example, the weight average molecular weight of the polymer component is about 600,000 g/mol or more, about 700,000 g/mol or more, or about 800,000 g/mol or more, about 850,000 g/mol or more, or about 2,500,000 g/mol or less. , 2,000,000 g/mol or less, 1,500,000 g/mol or less, or 1,300,000 g/mol or less.

When the molecular weight is within this range, desired viscoelastic properties can be secured, and durability can be advantageously secured under heat/moisture heat resistance conditions.

The pressure-sensitive adhesive layer formed by the pressure-sensitive adhesive composition as described above can excellently satisfy physical properties required for optical applications.

In one example, the pressure-sensitive adhesive layer may exhibit a gel fraction within a predetermined range. For example, the gel fraction of the pressure-sensitive adhesive layer, calculated by Equation 1 below, may be in the range of about 55% by weight to 90% by weight.

[Equation 1]

Gel content = B/A × 100

In Equation 1, A is the mass of the pressure-sensitive adhesive layer before immersion in ethyl acetate (unit: g), and B is the dry mass of the insoluble content recovered after immersing the pressure-sensitive adhesive layer in ethyl acetate at room temperature for 24 hours (unit: g). g). At this time, the insoluble matter means a component that is filtered through 200 mesh, and the dry mass of the insoluble matter is a state in which the solvent is not substantially included in the insoluble matter by drying the collected insoluble matter under appropriate conditions, For example, it means the mass measured in a state in which the content of the solvent is about 1% by weight or less, 0.5% by weight or less, or 0.1% by weight or less. In the above, the drying conditions are not particularly limited as long as the ratio of the solvent included in the insoluble matter can be controlled within the above range, and can be performed under appropriate conditions.

For example, the pressure-sensitive adhesive layer may have a storage modulus of about 30,000 Pa to about 70,000 Pa. In another example, the storage modulus may be about 35,000 Pa or more or 40,000 Pa or more, or about 65,000 Pa or less or about 60,000 Pa or less. This storage modulus is measured in the manner mentioned in the Examples below, and is measured at about 30°C. Within this elastic modulus range, light leakage of the polarizer is effectively suppressed, and other required durability can be satisfied.

The pressure-sensitive adhesive layer may have a peel strength of about 200 gf/25 mm to about 1,000 gf/25 mm to glass at room temperature. The peel force is about 900, about 800 gf / 25mm or less, about 700 gf / 25mm or less, about 680 gf / 25mm or less, 670 gf / 25mm or less, 660 gf / 25mm or less, 650 gf / 25mm or less, or about It may be less than 640 gf/25mm. Within this range, the polarizing plate may exhibit excellent durability in an optical element. In the present application, the peel force may be, for example, peel force measured at room temperature with respect to alkali-free glass at a peel rate of 300 mm/min and a peel angle of 180 degrees.

As an example, the pressure-sensitive adhesive layer may have a thickness of, for example, about 0.001 μm to about 100 μm. The thickness of the pressure-sensitive adhesive layer is within the above range, for example, about 0.1 μm or more, 1 μm or more, 5 μm or more, 10 μm or more, 20 μm or more, or about 25 μm or more, or about 80 μm or less, 60 μm or less, or 40 μm or less. It may be ㎛ or less, 30 ㎛ or less, or about 10 ㎛ or less, but is not limited thereto.

In one embodiment of the present application, the polarizing plate may further include a protective film on one side or both sides of the polarizing film. When a protective film is included on one side, the protective film may be included on at least the side opposite to the side of the polarizing film on which the pressure-sensitive adhesive layer is formed. Such a protective film may be laminated to the polarizing film through, for example, an adhesive layer or the like.

As the protective film, without particular limitation, for example, a COP (cycloolefin polymer)-based film, an acrylic film, a TAC (triacetylcellulose)-based film, a COC (cycloolefin copolymer)-based film, a PNB (polynorbornene)-based film, and a PET (polyethylene terephtalate) )-based films and the like may be used as single-layer or multi-layer films. The thickness of the protective film is not particularly limited.

The polarizing plate may further include a release film attached to the pressure-sensitive adhesive layer. As the release film, a structure common in this field can be employed. The polarizing plate may further include one or more functional layers selected from the group consisting of an antireflection layer, an antiglare layer, a retardation plate, a wide viewing angle compensation film, and a luminance enhancing film, if necessary.

This application also relates to a method for manufacturing a polarizing plate, eg, the polarizing plate described above. Such a manufacturing method includes, for example, forming a layer of at least the non-solvent type pressure-sensitive adhesive composition of a polarizing film or a layered product including the polarizing film (ie, a layered product including a polarizing film and a protective film, etc.); and curing the layer of the solvent-free pressure-sensitive adhesive composition. In the case of the present application, a pressure-sensitive adhesive layer may be directly formed on one surface of a polarizing film or polarizing plate through the application of a non-solvent-type pressure-sensitive adhesive, and thus, this process may be performed as a so-called in-line process.

In the above, the layer of the non-solvent type pressure-sensitive adhesive composition may be formed through a general coating method known in the art, for example, a bar coating method, a comma coating method, or an inkjet coating method.

After forming a layer of the non-solvent type pressure-sensitive adhesive composition in this way, it may be cured to form a pressure-sensitive adhesive layer. Such curing may be performed, for example, by irradiating light to the layer of the pressure-sensitive adhesive composition. Usually, ultraviolet rays or electron beams are irradiated with light, but it is not limited thereto.

In one example, the curing may be performed by irradiating ultraviolet light having a wavelength within a range of approximately 300 nm to 380 nm.

In one example, the curing may be performed by irradiating the layer of the pressure-sensitive adhesive composition with ultraviolet rays having an intensity in the range of 6 mW/cm ² to 7 mW/cm ² for 30 seconds to 210 seconds.

Within the above range, a desired degree of crosslinking may be secured without damaging components of the polarizing plate such as a polarizing film, thereby obtaining a polarizing plate having desired physical properties. In the above, the irradiation time of the ultraviolet rays is about 40 seconds or more, about 50 seconds or more, about 60 seconds or more, about 70 seconds or more, about 80 seconds or more, about 90 seconds or more, about 100 seconds or more, about 110 seconds or more. .

In the manufacturing method of the present application, except for forming a pressure-sensitive adhesive layer directly on one surface of a polarizing film or polarizing plate using the specific solvent-free pressure-sensitive adhesive composition, other elements may be performed according to a general manufacturing method of a polarizing plate.

This application also relates to a display device including the polarizing plate. For example, the display device of the present application may be an LCD or OLED, and in the case of an LCD, the device includes a liquid crystal panel and a polarizing plate provided on one or both surfaces of the liquid crystal panel, at least one of which is the above-mentioned polarizing plate. may be a polarizing plate.

The type of the liquid crystal panel is not particularly limited. For example, a passive matrix type panel such as a twisted nematic (TN) type, a super twisted nematic (STN) type, a ferroelectric (F) type, or a polymer dispersed (PD) type; an active matrix type panel such as a two terminal type or a three terminal type; In Plane Switching (IPS) panels; Alternatively, all known panels such as vertical alignment (VA) panels may be applied.

In addition, other configurations constituting the LCD, for example, types of upper and lower substrates (eg, color filter substrates or array substrates) are not particularly limited, and configurations known in the art may be employed without limitation. there is.

The present application is a polarizing plate to which a non-solvent-type pressure-sensitive adhesive layer is applied, and it is possible to provide a polarizing plate including a non-solvent-type pressure-sensitive adhesive layer with physical properties equal to or superior to those of the solvent-type pressure-sensitive adhesive layer while solving problems caused by the application of the existing solvent-type pressure-sensitive adhesive layer. .

Hereinafter, the polarizing plate of the present application will be described in detail through Examples and Comparative Examples. However, the scope of the present application is not limited by the following examples.

manufacturing example 1 Preparation of polymer component (A).

BA (butyl acrylate) and 4-HBA (4-hydroxybutyl acrylate) were mixed in a weight ratio of 99:1 (BA:4-HBA), and about 0.2 parts by weight of an azo thermal initiator (V- 65, Wako) was added, and bulk polymerization was performed so that the viscosity at room temperature (25° C.) was in the range of about 5000 cps to 10,000 cps to prepare a syrupy polymer component (A). The viscosity is maintained by maintaining the bulk polymer (polymer component (A)) at room temperature (25 ° C.) for more than 2 hours until bubbles are removed, and the spindle of the viscosity meter is submerged to the middle position of the groove, and the The number of rotations of the spindle was measured by adjusting the confidence to be between 30% and 80%, which is the same below.

manufacturing example 2 Preparation of polymer component (B).

Apply a composition in which BA (butyl acrylate), DMAA (N,N-dimethyl acrylamide) and 2-HEA (2-hydroxyethyl acrylate) are mixed in a weight ratio of 85:5:15 (BA:DMAA:2-HEA), By changing the ratio of the initiator, a bulk polymer having a viscosity of about 5000 cps to 10,000 cps cps (25° C.) was prepared, and a syrupy polymer component (B) was prepared in the same manner as in Preparation Example 1.

manufacturing example 3 Preparation of polymer component (C).

2-EHA (2-ethylhexyl acrylate), IBOA (isobornyl acrylate), DMAA (N,N-dimethyl acrylamide), EOEOEA (ethoxyethoxyethyl acrylate) and 2-HEA (2-hydroxyethyl acrylate) at 60:10:5:15: By applying a composition mixed at a weight ratio of 10 (2-EHA:IBOA:DMAA:EOEOEA:2-HEA) and changing the ratio of the initiator, a bulk polymer having a viscosity of about 5000 cps to 10,000 cps cps (25°C) was prepared to prepare a syrupy polymer component (C) in the same manner as in Preparation Example 1.

manufacturing example 4 Preparation of polymer component (D).

2-EHA (2-ethylhexyl acrylate), IBOA (isobornyl acrylate), DMAA (N,N-dimethyl acrylamide), EOEOEA (ethoxyethoxyethyl acrylate) and 2-HEA (2-hydroxyethyl acrylate) at a ratio of 50:20:5:15: By applying a composition mixed at a weight ratio of 10 (2-EHA:IBOA:DMAA:EOEOEA:2-HEA) and changing the ratio of the initiator, a bulk polymer having a viscosity of about 5000 cps to 10,000 cps cps (25°C) was prepared to prepare a syrupy polymer component (D) in the same manner as in Preparation Example 1.

manufacturing example 5 Preparation of polymer component (E).

A composition in which butyl acrylate (BA) and 4-hydroxybutyl acrylate (4-HBA) are mixed at a ratio of 99:1 (BA:4-HBA) is applied to a reactor in which nitrogen gas is refluxed and a cooling device is installed to facilitate temperature control, After adding 180 parts by weight of ethyl acetate as a solvent, nitrogen gas was purged for 60 minutes. While maintaining the temperature of the reactor at 67 ° C, the reaction initiator AIBN (azobisisobutyronite) was added in an amount of 0.05 parts by weight based on 100 parts by weight of the monomer, reacted for 8 hours, and diluted with ethyl acetate to obtain a solid content concentration of about A polymer component (E) having an amount of 30% by weight and a weight average molecular weight (Mw) of about 1,000,000 was prepared.

manufacturing example 6 Preparation of polymer component (F).

A mixture of 94:6 (BA:AA) of BA (butyl acrylate) and AA (acrylic acid) was applied to a reactor in which nitrogen gas was refluxed and a cooling device was installed to facilitate temperature control, and ethyl acetate was used as a solvent at 180 After adding the parts by weight, nitrogen gas was purged for 60 minutes. While maintaining the temperature of the reactor at 67 ° C, the reaction initiator AIBN (azobisisobutyronite) was added in an amount of 0.05 parts by weight based on 100 parts by weight of the monomer, reacted for 8 hours, and diluted with ethyl acetate to obtain a solid content concentration of about A polymer component (F) of the order of 30% by weight was prepared.

Example One.

Based on 100 parts by weight of the polymer component (A) of Preparation Example 1, about 0.2 parts by weight of photoinitiator (Irgacure 651), about 0.08 parts by weight of hexanediol diacrylate (HDDA) (first curing agent), about 0.2 parts by weight of a silane coupling agent (KBM-403, Shin-Etsu Silicone Co.), about 1.5 parts by weight of an organic salt (substance name: FC-4400 3M Co.), about 0.15 parts by weight of BPMA (Benzophenone methacrylate) (second curing agent), and about 0.01 parts by weight of HDI-based polyfunctional isocyanate (TKA-100, Asahika Sei Chemicals Co., Ltd.) was mixed to prepare a solvent-free pressure-sensitive adhesive composition. Subsequently, the solvent-free adhesive composition was coated on one side of a PVA-based polarizing plate having a TAC (triacetyl cellulose) protective film attached to both sides to a thickness of about 20 μm to 30 μm, and ultraviolet rays in the UV A region having a wavelength of 6 to 7 mW /cm ² The light intensity was irradiated for about 150 seconds to form an adhesive layer, and a polarizing plate was prepared.

Example 2.

About 0.3 parts by weight of photoinitiator (Irgacure 651), about 0.01 parts by weight of HDDA (hexanediol diacrylate) (first curing agent), about 0.2 parts by weight of a silane coupling agent (Example 1 and A solvent-free pressure-sensitive adhesive composition was prepared by mixing about 1.5 parts by weight of an organic salt (same kind as Example 1) and about 0.9 parts by weight of BPMA (same kind as Example 1) (second curing agent). A polarizing plate was prepared in the same manner as in 1.

Example 3.

About 0.3 parts by weight of photoinitiator (Irgacure 651), about 0.05 parts by weight of HDDA (hexanediol diacrylate) (first curing agent), about 0.2 parts by weight of a silane coupling agent (Example 1 and same kind), about 2.5 parts by weight of an organic salt (same kind as Example 1) and about 0.9 parts by weight of bifunctional urethane acrylate (manufacturer: Shinhwa TNC, product name: SUO-1020) (second curing agent) to obtain a solvent-free type A pressure-sensitive adhesive composition was prepared, and a polarizing plate was prepared in the same manner as in Example 1.

Example 4.

About 0.3 parts by weight of photoinitiator (Irgacure 651), about 0.1 parts by weight of HDDA (hexanediol diacrylate) (first curing agent), about 0.4 parts by weight of a silane coupling agent (Example 1 and same kind), about 2.5 parts by weight of organic salt (same kind as Example 1) and about 3.6 parts by weight of bifunctional urethane acrylate (manufacturer: LG Chem, product name: GD-304) (second curing agent) to obtain a solvent-free type A pressure-sensitive adhesive composition was prepared, and a polarizing plate was prepared in the same manner as in Example 1.

Example 5.

Based on 100 parts by weight of the polymer component (C) of Preparation Example 3, about 0.3 parts by weight of photoinitiator (Irgacure 651), about 0.05 parts by weight of HDDA (hexanediol diacrylate) (first curing agent), about 0.4 parts by weight of silane coupling agent (Example 1 and same kind), about 2.5 parts by weight of an organic salt (same kind as Example 1) and about 1.8 parts by weight of bifunctional urethane acrylate (manufacturer: LG Chem, product name: GD-304) (second curing agent) to obtain a solvent-free type A pressure-sensitive adhesive composition was prepared, and a polarizing plate was prepared in the same manner as in Example 1.

Example 6.

Based on 100 parts by weight of the polymer component (C) of Preparation Example 3, about 0.3 parts by weight of photoinitiator (Irgacure 651), about 0.05 parts by weight of HDDA (hexanediol diacrylate) (first curing agent), about 0.4 parts by weight of silane coupling agent (Example 1 and Same type), about 0.9 parts by weight of metal salt (substance name: HQ115, 3M) and about 1.8 parts by weight of bifunctional urethane acrylate (manufacturer: LG Chem, product name: GD-304) (second curing agent) to form a solvent-free adhesive A composition was prepared, and a polarizing plate was prepared in the same manner as in Example 1.

Example 7.

About 0.3 parts by weight of the photoinitiator (a mixture of Irgacure 651 and TPO), about 0.05 parts by weight of HDDA (hexanediol diacrylate) (first curing agent), about 0.4 parts by weight of a silane coupling agent ( Same kind as Example 1), about 1.2 parts by weight of metal salt (same kind as Example 6) and about 1 part by weight of bifunctional urethane acrylate (manufacturer: LG Chem, product name: GD-304) (second curing agent) mixed A non-solvent type pressure-sensitive adhesive composition was prepared, and a polarizing plate was prepared in the same manner as in Example 1.

comparative example One.

About 0.23 parts by weight of a silane coupling agent (same type as in Example 1), about 1.75 parts by weight of an organic salt (same type as in Example 1) and about 0.083 part by weight of a curing agent ( T-39M, Soken Co.) was mixed to prepare a solvent-type adhesive composition, and a polarizing plate was prepared in the same manner as in Example 1. However, in this process, UV irradiation was not performed, but instead, an adhesive was formed by aging at a temperature at which a curing reaction of the curing agent is possible.

comparative example 2.

About 0.1 parts by weight of a silane coupling agent (same type as in Example 1), about 4 parts by weight of an organic salt (same type as in Example 1) and about 2 parts by weight of an epoxy curing agent based on 100 parts by weight of the polymer component (F) of Preparation Example 6 was mixed to prepare a solvent-type pressure-sensitive adhesive composition, and a polarizing plate was prepared in the same manner as in Example 1. However, in this process, UV irradiation was not performed, but instead, an adhesive was formed by aging at a temperature at which a curing reaction of the curing agent is possible.

1. Molecular weight evaluation

The weight average molecular weight (Mw) of the pressure-sensitive adhesive was measured using GPC (Gel Permeation Chromatograph), and the GPC measurement conditions are as follows. In the preparation of the calibration curve, the measurement results were converted using standard polystyrene (Aglient system (manufactured by)). After coating the pressure-sensitive adhesive composition between two release films and forming the pressure-sensitive adhesive layer in the same manner as in Examples or Comparative Examples, the weight average molecular weight (Mw) thereof was evaluated.

< GPC Measurement condition>

Meter: Aglient GPC (Aglient 1200 series, U.S.)

Column: Connect 2 PL Mixed B

Column temperature: 40°C

Eluent: THF (Tetrahydrofuran)

Flow rate: 1.0 mL/min

Concentration: ~ 1mg/mL (100μl injection)

2. Gel fraction measurement method

After maintaining the pressure-sensitive adhesive layer prepared in Examples or Comparative Examples in a constant temperature and humidity room (23 ° C., 50% relative humidity) for 7 days, 0.2 g (= A in the gel fraction measurement formula) was collected. After the sampled adhesive layer was completely submerged in 50 mL of ethyl acetate, it was stored in a dark room at room temperature for 1 day. Subsequently, the portion (insoluble content) not dissolved in ethyl acetate was collected on a #200 stainless wire mesh, and dried at 150 ° C. for 30 minutes to measure the mass (dry mass of insoluble content = B in the gel fraction measurement formula) . Subsequently, the gel fraction (unit: %) was measured by substituting the measurement result into the following formula.

<Gel fraction measurement formula>

Gel fraction = B/A × 100

A: mass of adhesive (0.2 g)

B: dry mass of insoluble matter (unit: g)

3. Storage modulus measurement method

After cutting the adhesive layer prepared in Example or Comparative Example to produce a cylindrical specimen of 8 mm × 1 mm (= diameter × thickness), using a dynamic rheological property measuring instrument (ARES, RDA, TA Instruments Inc.) , The storage modulus was measured at 30° C. while applying shear stress between parallel plates at a frequency of 1 Hz.

4. Adhesion measurement method

The adhesive polarizer prepared in Example or Comparative Example was cut to have a horizontal length of 25 mm and a vertical length of 200 mm to prepare a specimen, and was attached to a glass plate through the pressure-sensitive adhesive layer of the specimen. Peel force was measured while peeling the adhesive polarizer at a peel angle of 90 degrees and a peel speed of 0.3 MPM at the time of 1 hour after the specimen was attached.

5. TML (Total Mass Loss) measurement method

TML is coated with a pressure-sensitive adhesive composition on a release film (MRF38, Mitsubishi Corporation) to a thickness of about 20 to 30 μm, and after covering the release film showing a lower peel force than the release film on the coating layer, UV rays are applied in the same manner as in the examples. was irradiated to form an adhesive layer. In the case of Comparative Example, a pressure-sensitive adhesive layer was formed in the same manner, but maintained at 80° C. for about 3 minutes before covering another release film without UV irradiation to form a pressure-sensitive adhesive layer, and the other release film was covered in the same way. A plurality of pressure-sensitive adhesive layers of the prepared sample were laminated to form a laminate having a thickness of 100 to 200 μm, and then cut to a horizontal and vertical length of 40 mm, respectively. A 50mm x 50mm mesh was prepared, and after measuring the weight (A, unit: g) of the mesh, an adhesive was attached to the mesh, and the weight (B, unit: g) was measured again. After drying the mesh of the sample with the adhesive attached in an oven at 105 ° C. for about 1 hour, the weight (C, unit: g) of the sample taken out was evaluated, and then the TML was evaluated according to the following TML formula.

[TML formula]

TML (%) = 100x(C-A)/(B-A).

6. Keying evaluation (rework)

The adhesive polarizer prepared in Examples or Comparative Examples was cut to 200 mm and 150 mm in width and length, respectively, and after being attached to alkali-free glass with a thickness of about 0.7 mm, stored at room temperature for 24 hours, or in an oven at 80 ° C. After being stored for about 1 hour, it was taken out, and after cooling at room temperature for 3 minutes, while peeling the polarizing plate from the glass, the presence or absence of a phenomenon in which the adhesive of the polarizing plate remained on the glass or a stain of the adhesive was observed. Keying characteristics were evaluated under the same conditions for Examples and Comparative Examples.

<Evaluation Criteria>

OK.: All 10 specimens were peeled cleanly without residue or stains.

NG.: Residual or smudged on at least 1 out of 10 specimens

7. Surface resistance measurement method

Surface resistance was evaluated in a known manner using a known measuring instrument.

8. Durability evaluation

The adhesive polarizers prepared in Examples and Comparative Examples were cut to have a width of about 180 mm and a length of about 320 mm, and were attached to a 19-inch commercially available liquid crystal panel. Thereafter, the panel to which the polarizing plate was attached was stored in an autoclave (50° C., 5 atmospheric pressure) for about 20 minutes to prepare a sample.

In the case of heat resistance durability, after the sample was left at 80° C. for 500 hours, the occurrence of bubbles and peeling was observed and evaluated according to the following criteria.

Moist heat resistance durability of the prepared sample was evaluated by visually observing the occurrence of bubbles and exfoliation according to the following criteria after leaving the sample at 60° C. and 90% relative humidity for 500 hours.

<Heat resistance and damp heat Durability Evaluation Criteria>

A: No bubbles or moxibustion based on 10 mm × 10 mm

B: Less than 10 bubbles and moxibustion based on 10 mm × 10 mm

C: Less than 30 bubbles and moxibustion based on 10 mm × 10 mm

D: Occurrence of air bubbles and moxibustion and lifting of the polarizer

The evaluation results according to the method described above are summarized and described in Table 1 below.

Example comparative example One 2 3 4 5 6 7 One 2 Elastic modulus (Pa) 43459 53929 33265 42352 41230 41402 59422 44312 88520 Adhesion (gf/25nn) 288 482 470 416 541 355 730 450 780 Molecular Weight (×10000g/mol) 110 95 100 100 100 100 100 180 200 Gel(%) 78 68 78 85 79 75 76 70 80 TML (%) 3.5 1.9 2.1 2.8 1.9 2.0 0.8 0 0 Keying OK OK OK OK NG NG OK OK OK Surface resistance (Ω) 2×10 ¹⁰ 2×10 ¹⁰ 2×10 ¹⁰ 6×10 ⁹ 6×10 ¹⁰ 5×10 ¹⁰ 5×10 ¹⁰ Less than 1×10 ¹¹ Less than 1×10 ¹¹ heat resistance C A A A A A A A A Moist heat resistance A A A A A A A A A

Claims (15)

polarizing film; And a non-solvent type pressure-sensitive adhesive layer formed on one surface of the polarizing film,
The non-solvent type pressure-sensitive adhesive layer may include a polymer component including an alkyl (meth)acrylate unit having an alkyl group having 4 to 20 carbon atoms and a monomer unit having a polar functional group; A pressure-sensitive adhesive layer of a non-solvent type pressure-sensitive adhesive composition containing a first curing agent and a second curing agent,
The first curing agent is a multifunctional acrylate having a molecular weight of 500 g/mol or less,
The second curing agent is a polarizing plate of benzophenone (meth)acrylate or polyfunctional urethane acrylate. The polarizing plate according to claim 1, wherein the polymer component comprises 40% to 99% by weight of an alkyl (meth)acrylate unit having an alkyl group having 4 to 20 carbon atoms. The polarizing plate according to claim 1, wherein the polar functional group is a hydroxy group or a carboxyl group. The polarizing plate of claim 1, wherein the polymer component includes a monomer unit having a polar functional group in an amount of 1 to 20 parts by weight based on 100 parts by weight of an alkyl (meth)acrylate unit having an alkyl group having 4 to 20 carbon atoms. The polarizing plate according to claim 1, wherein the polymer component further comprises a nitrogen-containing reactive monomeric unit. The polarizing plate according to claim 5, wherein the nitrogen-containing reactive monomer is dialkyl (meth)acrylamide. The polarizing plate according to claim 1, wherein the polymer component further comprises a unit of a monomer represented by Formula 1 below:
[Formula 1]

In Formula 1, R is hydrogen or an alkyl group, and P is a monovalent substituent having a non-aromatic ring structure having 3 to 20 carbon atoms. The polarizing plate according to claim 1, wherein the polymer component further comprises a unit of a monomer represented by Formula 2 below:
[Formula 2]

In Formula 2, Q is hydrogen or an alkyl group, U is an alkylene group having 1 to 4 carbon atoms, m is a number within the range of 1 to 5, and Z is hydrogen, an alkyl group or an aryl group. delete delete The polarizing plate of claim 1, wherein the solvent-free pressure-sensitive adhesive composition further comprises at least one selected from the group consisting of a silane coupling agent, an antioxidant, and an antistatic agent. The polarizing plate according to claim 1, further comprising a protective film on a side of the polarizing film opposite to the side of the pressure-sensitive adhesive layer. a polymer component including an alkyl (meth)acrylate unit having an alkyl group having 4 to 20 carbon atoms and a monomer unit having a polar functional group on at least one side of a polarizing film or a laminate including the polarizing film; Forming a layer of a non-solvent type pressure-sensitive adhesive composition containing a first curing agent and a second curing agent; And curing the layer of the solvent-free pressure-sensitive adhesive composition,
The first curing agent is a multifunctional acrylate having a molecular weight of 500 g/mol or less,
The second curing agent is a method for producing a polarizing plate of benzophenone (meth) acrylate or polyfunctional urethane acrylate. The method of claim 13, wherein the curing is performed by irradiating the layer of the pressure-sensitive adhesive composition with ultraviolet rays having an intensity in the range of 6 mW/cm ² to 7 mW/cm ² for 30 seconds to 210 seconds. A display device comprising the polarizing plate according to any one of claims 1 to 8, 11 and 12.