WO2013055154A2 - Double-sided polarizing plate and optical device including same - Google Patents

Abstract

The present invention relates to a double-sided polarizing plate and an optical device including the same, and the double-sided polarizing plate comprises: a polarizer; a first adhesive layer which is formed on one side of the polarizer; a second adhesive layer which is formed on the other side of the polarizer; a first transparent film which is formed on the first adhesive layer; and a second transparent film which is formed on the second adhesive layer, wherein the first adhesive layer and the second adhesive layer are formed by active energy ray-curable adhesives, and the thickness of the first adhesive layer is 0.1㎛ to 3㎛.

Description

Double-sided polarizer and optical device comprising the same

The present invention relates to a double-sided polarizing plate and an optical device including the same. More specifically, the adhesive layer on both sides of the polarizer can be cured by only one light irradiation, so that the manufacturing process is simple and the adhesive layer on the non-irradiated surface is also excellent. It relates to a double-sided polarizing plate developed to have an adhesive force and an optical device including the same.

BACKGROUND OF THE INVENTION A polarizer is a device for converting natural light into polarized light having a specific vibration direction. Recently, a polarizer is employed in various display devices such as a liquid crystal display and an organic light emitting device.

The polarizing plate is generally used in a structure in which a protective film is laminated using one or both surfaces of a polarizer made of polyvinyl alcohol (hereinafter referred to as 'PVA')-based resin dyed with dichroic dye or iodine. For example, triacetyl cellulose (TAC) -based films have been mainly used as polarizing plate protective films. However, the TAC film has a problem that it is easily deformed in a high temperature, high humidity environment. Accordingly, recently, protective films of various materials that can replace TAC films have been developed. For example, polyethylene terephthalate (PET), cycloolefin polymer (COP, cycloolefin polymer), and acrylic films may be used alone. Or a mixed use has been proposed.

On the other hand, as an adhesive that can be used to attach the polarizer and the protective film, an acrylic adhesive, a dry laminate adhesive mixed with a urethane resin solution and a polyisocyanate resin solution, styrene butadiene rubber adhesive, epoxy adhesive, polyvinyl alcohol adhesive , Urethane-based adhesives, adhesives containing polyester ionomer-type urethane resins and compounds having glycidyloxy groups, thermosetting adhesives, and the like are known, and among these, in particular, an aqueous adhesive comprising an aqueous solution of a polyvinyl alcohol-based resin. Sieve is mainly used.

However, in the case of the water-based adhesive, when using an acrylic film or a COP film other than TAC as a protective film, there is a problem that its use is limited depending on the film material because the adhesive strength is weak. In addition, in the case of the water-based adhesive, in addition to the problem of poor adhesion to the material, if the material of the protective film applied to both sides of the PVA device is different, the problem of curl generation of the polarizing plate by the drying process of the water-based adhesive and initial optical Problems such as deterioration of physical properties occur. Therefore, a photocurable non-aqueous adhesive has been proposed as an alternative to solve this problem.

However, photocurable non-aqueous adhesives generally have a high viscosity, so that the thickness of the final adhesive layer tends to be thicker than that of the water-based adhesive, which is why the polarizing plate is manufactured using the photocurable non-aqueous adhesive layer. There is a problem that defects are likely to occur, such as wrinkles occurring in the TD direction and the MD direction.

In addition, in the case of a double-sided polarizing plate having a protective film attached to both surfaces of the polarizer, the adhesive layers formed on both surfaces of the polarizer have to be cured, respectively, and thus, the light irradiation has to be carried out twice. Although the adhesive layer may be cured by a single light irradiation, in this case, due to the difference in the amount of light reaching the light irradiation surface and the non-irradiation surface, the degree of curing of the adhesive layer is not the same, and as a result, the adhesive strength of the non-irradiation surface occurs. As such, when the adhesive force of the adhesive layer is lowered, durability of the polarizing plate is deteriorated, which causes a problem that optical properties are lowered.

The present invention is to solve the above problems, it is possible to cure the adhesive layer on both sides of the polarizer by only one light irradiation, the manufacturing process is simple, the double-sided polarizing plate developed to have an excellent adhesive strength of the non-irradiated surface and It is intended to provide an optical device including the same.

In one aspect, the present invention is a polarizer, a first adhesive layer formed on one surface of the polarizer, a second adhesive layer formed on the other surface of the polarizer, a first transparent film formed on the first adhesive layer, and the second A double-sided polarizing plate comprising a second transparent film formed on an adhesive layer, wherein the first adhesive layer and the second adhesive layer are formed by an active energy ray-curable adhesive, the thickness of the first adhesive layer is 0.1 to 3 A double-sided polarizing plate having a thickness is provided.

At this time, the thickness of the second adhesive layer is preferably about 0.1 to 10㎛. In addition, the double-sided polarizing plate of the present invention is prepared by simultaneously curing the first adhesive layer and the second adhesive layer by one active energy ray irradiation, the active energy ray irradiation is made of a transparent film formed on the second adhesive layer It is preferably carried out via an active energy source located in the direction.

On the other hand, the first adhesive layer and the second adhesive layer is more preferably formed by a cationic adhesive, wherein the cationic adhesive is (1) 5 to 90 weight of the epoxy compound having at least two epoxy groups in the molecule part; (2) 5 to 90 parts by weight of an oxetane compound having at least one oxetanyl group in the molecule; And (3) 0.5 to 20 parts by weight of the photo cationic polymerization initiator.

In addition, the double-sided polarizing plate may further include a primer layer between at least one of the first adhesive layer and the first transparent film and between the second adhesive layer and the second transparent film, wherein the primer layer Silver is preferably formed by a primer composition comprising 1 to 50 parts by weight of a urethane polymer, 0.1 to 10 parts by weight of water-dispersible fine particles and the remainder of water.

In another aspect, the present invention provides an optical device including the double-sided polarizing plate configured as described above.

In the double-sided polarizing plate of the present invention, by forming the adhesive layer on the non-irradiation surface of the active energy ray at 0.1 to 3 µm, the adhesive layer on both sides of the polarizer can be simultaneously formed through one active energy ray irradiation step, thereby simplifying the manufacturing process.

In addition, the double-sided polarizing plate of the present invention is excellent in adhesion between the polarizer and the transparent film, and excellent in heat resistance and water resistance, and has excellent optical properties even in harsh environments.

Hereinafter, the present invention will be described in more detail.

The present inventors have studied to develop a double-sided polarizing plate that is simple in manufacturing but excellent in durability, heat resistance, and optical properties. As a result, the adhesive layer is formed using an active energy ray-curable adhesive, and at the same time, the thickness of the adhesive layer is specified. To develop a double-sided polarizing plate of the present invention, characterized in that forming.

More specifically, the present invention is a polarizer, a first adhesive layer formed on one surface of the polarizer, a second adhesive layer formed on the other surface of the polarizer, a first transparent film formed on the first adhesive layer, and A double-sided polarizing plate including a second transparent film formed on an adhesive layer, wherein the first adhesive layer and the second adhesive layer are formed by an active energy ray-curable adhesive, and the thickness of the first adhesive layer is 0.1 to It relates to a double-sided polarizing plate of 3㎛.

In the present specification, the double-sided polarizing plate means a polarizing plate in which a protective film is attached to both surfaces of the polarizer, and is a concept distinguished from the single-sided polarizing plate in which a protective film is attached only to one surface of the polarizer.

Conventionally, in the double-sided polarizing plate, it was common that the thickness of the 1st adhesive bond layer and the 2nd adhesive bond layer was the same, and the thickness of the adhesive bond layer was about 5-10 micrometers. However, in the case of the conventional double-sided polarizing plate having such an adhesive thickness, in order to obtain sufficient adhesive strength, the first adhesive layer and the second adhesive layer had to be irradiated with light and cured. When only one light irradiation is performed, the adhesive layer in the direction of light irradiation can secure sufficient adhesive strength, but the adhesive layer in the direction in which light is not irradiated has a problem that the adhesive strength is inferior. Therefore, the conventional double-sided polarizing plate has a problem that its manufacturing process is cumbersome.

However, as a result of the researches of the present inventors, surprisingly, when forming the thickness of the adhesive layer (conventionally referred to as the 'first adhesive layer') of 0.1 to 3㎛ formed in the direction in which the active energy ray is not irradiated, once light irradiation It was found that excellent adhesive strength can be secured in both the adhesive layers formed on both sides of the polarizer alone. Table 1 below shows the results of measuring the peel force according to the thickness of the first adhesive layer formed on the non-irradiated active energy ray.

Table 1

First adhesive layer thickness	1st adhesive layer peeling force [N]
> 1 μm	2.5
1 μm	2.5
3 μm	2.5
5 μm	1.5
7㎛	0.5
10 μm	0.2

As shown in Table 1 above, when the thickness of the first adhesive layer exceeds 3 µm, the adhesive layer peeling force is significantly lowered. As such, when the adhesive layer peeling force is lowered, the polarizer and the transparent film may be easily peeled off, which adversely affects the polarizer durability and optical properties.

On the other hand, in the case of the adhesive layer (for convenience, referred to as the 'second adhesive layer') formed in the direction in which the active energy ray is irradiated, it was found that the difference in adhesion strength does not occur largely depending on the thickness. However, when the thickness of the second adhesive layer is too thick, wrinkles may occur in the polarizing plate, which is the final product, and the thinner the second adhesive layer is, the more preferable. For example, in the present invention, the thickness of the second adhesive layer may be formed about 0.1 to 10 μm, preferably about 0.1 to 7 μm, and most preferably about 0.1 to 5 μm.

The double-sided polarizing plate of the present invention configured as described above may be manufactured by simultaneously curing the first adhesive layer and the second adhesive layer by one active energy ray irradiation, wherein the active energy ray irradiation is on the second adhesive layer It is preferably carried out via an active energy source located in the direction of the transparent film formed on the. In this case, the active energy rays include ultraviolet rays, electron beams, microwaves, infrared rays (IR), X-rays and gamma rays, as well as alpha-particle beams, proton beams, and neutron beams. Particle beams such as (neutron beam) may be included, and typically ultraviolet rays or electron beams may be used.

On the other hand, in the present invention, it is preferable that the first adhesive layer and the second adhesive layer are formed of an active energy ray curable adhesive cured by an active energy ray. On the other hand, in order to form the thickness of the adhesive layer as described above, the viscosity of the active energy ray-curable adhesive is preferably about 15 to 50 cP. In addition, in consideration of durability and thermal shock resistance, the active energy curable adhesive has a glass transition temperature of 90 ° C. or more.

More preferably, in the present invention, the first adhesive layer and the second adhesive layer are preferably formed of a cationic adhesive. The cationic adhesive herein refers to an adhesive whose main component is a compound which is cured through a cationic polymerization reaction.

For example, the cationic adhesive includes (1) 5 to 90 parts by weight of an epoxy compound having at least two epoxy groups in a molecule; (2) 5 to 90 parts by weight of an oxetane compound having at least one oxetanyl group in the molecule; And (3) 0.5 to 20 parts by weight of the photo cationic polymerization initiator.

The epoxy compound (1) only needs to have at least two epoxy groups in the molecule, and the kind thereof is not particularly limited. For example, epoxy resins well known in the art such as aromatic epoxy, alicyclic epoxy, or aliphatic epoxy are known. These may be used alone or in combination.

In this case, the aromatic epoxy refers to an epoxy containing an aromatic group in the molecule, for example, bisphenol-type epoxy resins such as bisphenol A-based epoxy, bisphenol F-based epoxy, bisphenol S epoxy, brominated bisphenol-based epoxy; Novolac type epoxy resins such as phenol novolac type epoxy resins and cresol novolac type epoxy resins; Cresol epoxy, resorcinol glycidyl ether and the like can be used.

On the other hand, the alicyclic epoxy means a compound in which an epoxy group is formed between two adjacent carbon atoms constituting an aliphatic ring, for example, dicyclopentadiene dioxide, limonene dioxide, 4-vinylcyclohexenedio Seeds, 2,4-epoxycyclohexylmethyl 3,4-epoxycyclohexanecarboxylate, dicyclopentadiene dioxide, bis (3,4-epoxycyclohexylmethyl) adipate and the like can be used.

On the other hand, the aliphatic epoxy includes polyglycidyl ether of aliphatic polyhydric alcohol; Polyglycidyl ethers of alkylene oxide adducts of aliphatic polyhydric alcohols and the like can be used.

At this time, as said aliphatic polyhydric alcohol, the thing in the range of C2-C20 can be illustrated, for example. More specifically, for example, ethylene glycol, 1,2-propanediol, 1,3-propanediol, 2-methyl-1,3-propanediol, 2-butyl-2-ethyl-1,3-propane Diol, 1,4-butanediol, neopentylglycol, 3-methyl-2,4-pentanediol, 2,4-pentanediol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, 2- Methyl-2,4-pentanediol, 2,4-diethyl-1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 3,5-heptanediol, 1,8-octanediol Aliphatic diols such as 2-methyl-1,8-octanediol, 1,9-nonanediol, and 1,10-decanediol; Alicyclic diols such as cyclohexanedimethanol, cyclohexanediol, hydrogenated bisphenol A and hydrogenated bisphenol F; And trivalent or higher polyols such as trimethylol ethane, trimethylol propane, hexitols, pentitols, glycerin, polyglycerol, pentaerythritol, dipentaerythritol and tetramethylol propane.

Moreover, as said alkylene oxide, more specifically, ethylene oxide, a propylene oxide, butylene oxide etc. are mentioned, for example.

Meanwhile, the present invention is not limited thereto, but in the present invention, the epoxy compound includes a epoxidized aliphatic ring group, that is, a first epoxy compound including at least one alicyclic epoxy ring and a second including at least one glycidyl ether group. Particular preference is given to using combinations of epoxy compounds.

When using a combination of the first epoxy compound and the second epoxy compound as described above can be prepared an adhesive for polarizing plate with improved thermal shock properties, wherein the first epoxy compound and the second epoxy compound is 1: 1 to 3: It is preferable to be used by mixing in a weight ratio of 1, more preferably, it can be used by mixing in a weight ratio of 1: 1 to 2: 1, most preferably the first epoxy compound and the second epoxy compound 1: It is used by mixing in the weight ratio of 1. When the weight ratio of the first epoxy compound and the second epoxy compound satisfies the above range, most preferable physical properties can be obtained in terms of glass transition temperature, adhesive strength and viscosity. In the present invention, the first epoxy and the second epoxy may be included in an amount of 20 to 60 parts by weight based on 100 parts by weight of the total adhesive composition, for example.

The first epoxy compound is, for example, 3,4-epoxycyclohexylmethyl-3,4'-epoxycyclohexanecarboxylate, bis (3,4-epoxy cyclohexylmethyl) adipate dicyclopentadiene dioxide At least one selected from the group consisting of limonene dioxide and 4-vinylcyclohexene dioxide. The first epoxy compound is to increase the Tg and to impart the hardness of the adhesive layer, most preferably 3,4-epoxycyclohexylmethyl-3,4'-epoxycyclohexanecarboxylate.

The second epoxy compound is not particularly limited as long as it contains at least one glycidyl ether group. For example, 1,4-cyclohexanedimethanol diglycidyl ether, novolac epoxy, bisphenol A-based epoxy, bisphenol F Epoxy, brominated bisphenol epoxy, 1,6-hexanediol diglycidyl ether, trimethylolpropanetriglycidyl ether, n-butyl glycidyl ether, aliphatic glycidyl ether (C12-C14), 2- At least one selected from the group consisting of ethylhexyl glycidyl ether, phenyl glycidyl ether, o-cresyl glycidyl ether, and nonyl phenyl glycidyl ether. The second epoxy compound is to impart softness to improve adhesion, and more preferably include an aliphatic ring, and most preferably 1,4-cyclohexanedimethanol diglycidyl ether. .

Next, the (2) oxetane compound is not particularly limited as long as it has at least one oxetanyl group in the molecule, and various oxetane compounds well known in the art may be used. For example, as the oxetane compound of the present invention, 3-ethyl-3-[(3-ethyloxetan-3-yl) methoxymethyl] oxetane, 1,4-bis [(3-ethyl jade Cetane-3-yl) methoxymethyl] benzene, 1,4-bis [(3-ethyloxetan-3-yl) methoxy] benzene, 1,3-bis [(3-ethyloxetan-3-yl ) Methoxy] benzene, 1,2-bis [(3-ethyloxetan-3-yl) methoxy] benzene, 4,4'-bis [(3-ethyloxetan-3-yl) methoxy] ratio Phenyl, 2,2'-bis [(3-ethyloxetan-3-yl) methoxy] biphenyl, 3,3 ', 5,5'-tetramethyl-4,4'-bis [(3-ethyl Oxetan-3-yl) methoxy] biphenyl, 2,7-bis [(3-ethyloxetan-3-yl) methoxy] naphthalene, bis [4-{(3-ethyloxetan-3-yl ) Methoxy} phenyl] methane, bis [2-{(3-ethyloxetan-3-yl) methoxy} phenyl] methane, 2,2-bis [4-{(3-ethyloxetan-3-yl ) Methoxy} phenyl] propane, etherified modified product of novolak type phenol-formaldehyde resin with 3-chloromethyl-3-ethyloxetane, 3 (4), 8 (9) -bis [(3-ethyl Oxetane -3-yl) methoxymethyl] -tricyclo [5.2.1.0 2,6] decane, 2,3-bis [(3-ethyloxetan-3-yl) methoxymethyl] norbornane, 1,1 , 1-tris [(3-ethyloxetan-3-yl) methoxymethyl] propane, 1-butoxy-2,2-bis [(3-ethyloxetan-3-yl) methoxymethyl] butane, 1,2-bis [{2- (3-ethyloxetan-3-yl) methoxy} ethylthio] ethane, bis [{4- (3-ethyloxetan-3-yl) methylthio} phenyl] sul Feed, 1,6-bis [(3-ethyloxetan-3-yl) methoxy] -2,2,3,3,4,4,5,5-octafluorohexane, etc. are mentioned. On the other hand, the content of the oxetane compound is 5 to 90 parts by weight, more preferably 10 to 90 parts by weight.

Next, the cationic photopolymerization initiator (3) is a compound which produces a cation species or Lewis acid by irradiation of an active energy ray, for example, an aromatic diazonium salt, an aromatic iodine aluminum salt or an aromatic sulfonium salt. Onium salts, iron-arene complexes, and the like, but is not limited thereto. On the other hand, the content of the cationic photopolymerization initiator is about 0.5 to 20 parts by weight, preferably about 0.5 to 15 parts by weight, and more preferably about 0.5 to 10 parts by weight based on 100 parts by weight of the total adhesive composition.

On the other hand, the cationic adhesive composition of the present invention, together with the components, may further comprise a vinyl compound, if necessary. When the vinyl compound is added, it is possible to maintain low viscosity and to reduce the phenomenon that the glass transition temperature of the adhesive layer is lowered after curing.

As the vinyl compound, for example, hydroxy C _1-6 alkyl vinyl ether and / or vinyl acetate may be used, and the hydroxy C _1-6 alkyl vinyl ether may be selected from hydroxyethyl vinyl ether and hydroxy. At least one selected from the group consisting of oxybutyl vinyl ether, 1,4-cyclohexanedimethanol vinyl ether, 4- (hydroxymethyl) cyclohexylmethyl vinyl ether, ethylene glycol vinyl ether, diethylene glycol monovinyl ether have. On the other hand, the vinyl compound may be included in a ratio of 0.1 parts by weight to 10 parts by weight, or 0.1 parts by weight to 5 parts by weight with respect to 100 parts by weight of the entire adhesive composition.

In addition, the cationic adhesive composition of the present invention may further include a silane coupling agent, as necessary, with the components. When the silane coupling agent is included, the silane coupling agent lowers the surface energy of the adhesive, thereby improving the adhesive wetting property.

At this time, the silane coupling agent more preferably comprises a cationically polymerizable functional group such as an epoxy group, a vinyl group, and a radical group. When the present inventors use the silane coupling agent containing the cationically polymerizable functional group, unlike the case of using the silane coupling agent which does not contain surfactant or cationically polymerizable functional group, wetting property does not reduce the glass transition temperature of an adhesive agent. I found out that it could be improved. It is believed that this is because the cationic polymerizable functional group of the silane coupling agent reacts with the silane group of the adhesive composition to form a crosslinked form, thereby reducing the phenomenon that the glass transition temperature of the adhesive layer is lowered after curing.

The silane coupling agent usable in the present invention is not limited thereto, but may be, for example, a silane coupling agent represented by the following Chemical Formula 1.

Si (R ₁ ) _n (R ₂ ) _4-n

In Formula [1], R ₁ is a cationically polymerizable functional group bonded to a silicon atom, and is a functional group including a cyclic ether group or a vinyloxy group, and R ₂ is hydrogen, a hydroxy group, an alkyl group bonded to a silicon atom, or It is an alkoxy group, n is an integer of 1-4.

Specific examples of the silane coupling agent satisfying the above [Formula 1] include 2- (3,4-epoxycyclohexyl) ethyl trimethoxy silane, 3-glycidoxypropyl trimethoxy silane, glycidoxypropyl methyldie Oxy silane, glycidoxypropyl triethoxy, vinyltrimethoxysilane or vinyltriethoxysilane may be exemplified, but is not limited thereto.

As the silane coupling agent usable in the present invention, an oligomer-type silane compound in which the above-mentioned cationically polymerizable functional group is introduced into the molecule of the siloxane oligomer may be used. In this case, the siloxane oligomer may be a relatively low molecular weight silicone resin in which the terminal of the molecular chain is sealed with an alkoxysilyl group.

In this case, the cationic adhesive composition may include the silane compound in a ratio of 0.1 parts by weight to 10 parts by weight, or 0.1 parts by weight to 5 parts by weight with respect to 100 parts by weight of the entire adhesive composition. In this range, the adhesive layer may exhibit appropriate surface energy and adhesion.

 In addition, the said cationic adhesive composition of this invention can contain a radically polymerizable monomer further as needed. The radically polymerizable monomer may be used without limitation as long as it is a compound having a radical reactive functional group, for example, (meth) acrylates having one or more (meth) acryloyl groups in a molecule, (meth) acrylamides, Maleimide, (meth) acrylic acid, maleic acid, itaconic acid, (meth) acrylaldehyde, (meth) acryloyl morpholine, N-vinyl-2-pyrrolidone, triallyl isocyanurate, etc. can be used. .

At this time, as a specific example of (meth) acrylate which has one (meth) acryloyl group in the said molecule, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, isopropyl (meth) acryl Rate, butyl (meth) acrylate, isobutyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, octyl (meth) acrylate, isooctyl (meth) acrylate, lauryl (meth) acrylate, Stearyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, cyclohexyl (meth) acrylate, iso Boryl (meth) acrylate, 1,4-cyclohexanedimethylolmono (meth) acrylate, dicyclopentanyl (meth) acrylate, dicyclopentenyl (meth) acrylate, dicyclopentenyloxyethyl (meth Acrylate, Ben Quality (meth) acrylate, (meth) acrylate of phenol alkylene oxide adduct, (meth) acrylate of p-cumylphenol alkylene oxide adduct, (meth) acrylate of o-phenylphenol alkylene oxide adduct, nonyl (Meth) acrylate of (meth) acrylate of phenol alkylene oxide adduct, (meth) acrylate of alkylene oxide adduct of 2-methoxyethyl (meth) acrylate, ethoxyethoxyethyl (meth) acrylate, and 2-ethylhexyl alcohol , Ethylene glycol mono (meth) acrylate, propylene glycol mono (meth) acrylate, pentanediol mono (meth) acrylate, hexanediol mono (meth) acrylate, mono (meth) acrylate of diethylene glycol, triethylene Mono (meth) acrylate of glycol, mono (meth) acrylate of tetraethylene glycol, mono (meth) acrylate of polyethylene glycol, mono (meth) of dipropylene glycol ) Acrylate, mono (meth) acrylate of tripropylene glycol, mono (meth) acrylate of polypropylene glycol, 2-hydroxy-3-phenoxypropyl (meth) acrylate, 2-hydroxy-3-part Methoxypropyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, caprolactone modified tetrahydrofurfuryl (meth) acrylate, 2-ethyl-2-methyl-1,3-dioxolan-4-yl) Methyl (meth) acrylate, (2-isobutyl-2-methyl-1,3-dioxolan-4-yl) methyl (meth) acrylate, (1,4-dioxaspiro [4,5] decane- 2-yl) methyl (meth) acrylate, glycidyl (meth) acrylate, 3,4-epoxycyclohexylmethyl (meth) acrylate, (3-ethyloxetan-3-yl) methyl (meth) acrylic Late, 2- (meth) acryloyloxymethyl isocyanate, allyl (meth) acrylate, N- (meth) acryloyloxyethyl hexahydrophthalimide, N- (meth) acryloyl Cethylethyl tetrahydrophthalimide, 2- (meth) acryloyloxyethylhexahydrophthalic acid, 2- (meth) acryloyloxyethyl succinic acid, ω-carboxy-polycaprolactone mono (meth) acrylate, 2- (Meth) acryloyloxyethyl acid phosphate etc. are mentioned.

Moreover, as a specific example of the said ((meth) acrylamides, (meth) acrylamide, N, N-dimethyl (meth) acrylamide, N, N-diethyl (meth) acrylamide, N-methylol (meth) acryl Amide, N- (3-N, N-dimethylaminopropyl) (meth) acrylamide, methylenebis (meth) acrylamide, ethylenebis (meth) acrylamide, N, N-diallyl (meth) acrylamide, etc. Can be mentioned.

Moreover, as a specific example of the said maleimide, the urethane acryl of N-methyl maleimide, N-hydroxyethyl maleimide, N-hydroxyethyl citraconimide, N-hydroxyethyl citraconimide, and isophorone diisocyanate The rate etc. are mentioned.

As a specific example of (meth) acrylates which have two (meth) acryloyl groups in a molecule | numerator, 1, 3- butanediol di (meth) acrylate, 1, 6- hexanediol di (meth) acrylate, 1, 9 -Nonanediol di (meth) acrylate, 1,10-decanedioldi (meth) acrylate, 1,3-butylene glycol di (meth) acrylate, 2-methacryloyloxyethyl ethane phosphate, ethylene Glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate, dipropylene glycol di (meth) acrylate, tripropylene Glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, cyclohexanedimethanol di (meth) acrylate, polyethylene glycol di (meth) acrylate, polyethylene glycol (200) di (meth) acrylate, Polyethylene Recall (400) di (meth) acrylate, polyethylene glycol (600) di (meth) acrylate, glycerin di (meth) acrylate, 2-hydroxy-3-acrylooxypropylmethacrylate, dimethylol tricycle Rodecanedi (meth) acrylate etc. are mentioned.

Specific examples of (meth) acrylates having three (meth) acryloyl groups in the molecule include trimethylolpropane tri (meth) acrylate, trimethylolpropane tri (meth) acrylate, and trimethylolpropane tri (meth) acrylate. , Ditrimethylolpropane tri (meth) acrylate, trimethylpropane tri (meth) acrylate, tri (2-hydroxy ethyl) isocyanurate triacrylate, tri (2-hydroxy ethyl) isocyanurate, Pentatrithyl triacrylate, ethoxylate trimethylolpropane tri (meth) acrylate, and proxies trimethylolpropane tri (meth) acrylate.

As a specific example of the (meth) acrylate which has four or five (meth) acryloyl groups in a molecule | numerator, pentatrithol tetra (meth) acrylate, ditrimethylolproran tetra (meth) acrylate, dipentatritol penta (Meth) acrylate, an epoxide pentatrithitol tetra (meth) acrylate, a pentaacrylate ester, etc. are mentioned.

Specific examples of the (meth) acrylates having six meta) acryloyl groups in the molecule include dipentarititol hexa (meth) acrylate.

On the other hand, the content of the radically polymerizable monomer is about 0 to 40 parts by weight, preferably about 5 to 30 parts by weight, and more preferably about 5 to 25 parts by weight based on 100 parts by weight of the total adhesive composition.

On the other hand, when an adhesive composition contains a radically polymerizable monomer as mentioned above, it is preferable to mix | blend a radical photopolymerization initiator in order to promote the radical polymerization property and to improve hardening speed. Examples of the radical photopolymerization initiator include, but are not limited to, acetophenone photopolymerization initiator, benzoin ether photopolymerization initiator, benzophenone photopolymerization initiator, thioxanthone photopolymerization initiator, and the like. have. The content of the radical photopolymerization initiator is about 0.5 to 20 parts by weight, preferably about 0.5 to 15 parts by weight, and more preferably about 0.5 to 10 parts by weight based on 100 parts by weight of the total adhesive composition.

The cationic adhesive composition may further include a photosensitizer, an antioxidant, an oligomer, and an adhesion promoter as needed, and preferably further include urethane acrylate in an amount greater than 0 and 4 or less. When the urethane acrylate is added as described above, the viscosity tends to increase, but the elevated viscosity of the adhesive may be lowered by adding temperature. On the other hand, when the urethane acrylate is added as described above, it is possible to give a more suitable adhesive force in use for the acrylic film.

Since the adhesive composition of the present invention as described above has a low viscosity of about 15 to 50 cP, it is excellent in workability and exhibits excellent adhesion at a thin adhesive layer thickness.

In addition, the adhesive composition of the present invention is very excellent in heat resistance with a glass transition temperature of 90 ℃ or more after curing. In fact, when the polarizing plate manufactured using the adhesive composition of the present invention evaluated the heat resistance and thermal shock resistance of 80 ℃, it was shown that the polarizer crack does not occur.

In addition, the polarizing plate produced using the adhesive composition of the present invention, when immersed in water at 60 ℃ temperature for 24 hours, the polarizer discoloration was found to be very excellent in water resistance to less than 10mm in the MD direction.

As described above, the cationic adhesive has excellent adhesion to films of various materials, and is excellent in water resistance, heat resistance, and the like, and thus, a polarizing plate having excellent properties may be manufactured.

Meanwhile, the double-sided polarizing plate of the present invention may further include a primer layer between at least one of the first adhesive layer and the first transparent film and between the second adhesive layer and the second transparent film.

The primer layer is for improving the adhesion between the transparent film and the adhesive layer, it is preferably formed of a primer composition containing a urethane polymer. For example, the primer composition comprises a urethane polymer, water dispersible fine particles and water, and more specifically, 1 to 50 parts by weight of the urethane polymer and water dispersible fine particles 0.1 to 10 based on 100 parts by weight of the primer composition. It may comprise a part by weight and the balance of water.

The urethane polymer is obtained by reacting a polyol and a polyisocyanate. The polyol is not particularly limited as long as it has two or more hydroxyl groups in the molecule, and any appropriate polyol can be employed. For example, the polyol may be a polyester polyol, a polyether polyol, a polycarbonate diol, or the like, and may be used alone or in combination of two or more as at least one selected from the group consisting of these.

The polyol may be ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, neopentyl glycol, pentanediol, 1,6-hexanediol, 1,8 -Octanediol, 1,10-decanediol, 4,4'-dihydroxyphenylpropane, 4,4'-dihydroxymethylmethane, diethylene glycol, triethylene glycol, polyethylene glycol, dipropylene glycol, polypropylene Glycol, 1,4-cyclohexanedimethanol, 1,4-cyclohexanediol, bisphenol A, bisphenol F, glycerin, 1,1,1-trimethylolpropane, 1,2,5-hexatriol, pentaerytri It is preferably at least one selected from the group consisting of all, glucose, sucrose, and sorbitol.

On the other hand, the polyester polyol is typically obtained by reacting the polybasic acid component and the polyol component. As the polybasic acid component, for example, ortho-phthalic acid, isophthalic acid, terephthalic acid, 1,4-naphthalenedicarboxylic acid, 2,5-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, biphenyl Aromatic dicarboxylic acids such as dicarboxylic acid and tetrahydrophthalic acid; Aliphatic dicarboxylic acids such as oxalic acid, succinic acid, malonic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, linoleic acid, maleic acid, fumaric acid, mesaconic acid and itaconic acid; Alicyclic dicarboxylic acids such as hexahydrophthalic acid, tetrahydrophthalic acid, 1,3-cyclohexanedicarboxylic acid, and 1,4-cyclohexanedicarboxylic acid; Or reactive derivatives such as acid anhydrides, alkyl esters, and acid halides thereof. These can be used individually or in combination of 2 or more types. Furthermore, it is more preferable that it is at least 1 sort (s) chosen from the group which consists of polytetramethylene glycol (PTMG), polypropylene glycol (PPG), and polyethylene glycol (PEG).

The polycarbonate polyol is preferably at least one selected from the group consisting of poly (hexamethylene carbonate) glycol and poly (cyclohexanecarbonate) glycol.

The polyether polyol may be typically obtained by ring-opening polymerization of an alkylene oxide to a polyhydric alcohol. As a polyhydric alcohol, ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, glycerin, trimethylol propane, etc. are mentioned, for example. These can be used individually or in combination of 2 or more types.

The isocyanate is not limited as long as it is a compound having two or more NCO groups, for example, toluene diisocyanate (TDI), 4,4-diphenylmethane diisocyanate (MDI), 1,5-naphthalene diisocyanate (NDI), toll Group consisting of lidine diisocyanate (TODI), hexamethylene diisocyanate (HMDI), isopron diisocyanate (IPDI), p-phenylene diisocyanate, transcyclohexane, 1,4-diisocyanate and xylene diisocyanate (XDI) It can be used alone or in combination of two or more thereof.

The method for producing the urethane resin may employ any suitable method known in the art. Specifically, the one-shot method which makes each said component react at once, and the multistage method which reacts in steps are mentioned. In the case where the urethane resin has a carboxyl group, the urethane resin is preferably manufactured by a multistage method, and according to the multistage method, a carboxyl group can be easily introduced. Furthermore, any suitable urethane reaction catalyst can be used in the production of the urethane resin.

In the preparation of the urethane resin, other polyols and / or other chain extenders may be reacted in addition to the above components.

As another polyol, the polyol which has three or more hydroxyl groups, such as sorbitol, glycerin, trimethylol ethane, trimethylol propane, pentaerythritol, is mentioned, for example.

As another chain extender, for example, ethylene glycol, diethylene glycol, triethylene glycol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, neopentylglycol, pentanediol, 1,6- Glycols such as hexanediol and propylene glycol; Aliphatic diamines such as ethylenediamine, propylenediamine, hexamethylenediamine, 1,4-butanediamine, and aminoethyl ethanolamine; Alicyclic diamines such as isophorone diamine and 4,4'-dicyclohexyl methanediamine; Aromatic diamine, such as xylylenediamine and tolylenediamine, etc. are mentioned.

Furthermore, a neutralizing agent can be used in manufacture of the said urethane resin. By using a neutralizing agent, the stability of the urethane resin in water can be improved. Examples of the neutralizing agent include ammonia N-methylmorpholine, triethylamine, dimethylethanolamine, methyldiethanolamine, triethanolalkyne, morpholine, tripropylamine, ethanol amine, triisopropanolamine and the like. These can be used individually or in combination of 2 or more types.

In the production of the urethane resin, an organic solvent which is inert to the polyisocyanate and compatible with water is preferably used. As said organic solvent, Ester solvent, such as ethyl acetate and an ethyl cellosolve acetate; Ketone solvents such as acetone, methyl ethyl ketone and methyl isobutyl ketone; Ether solvents, such as dioxane tetrahydrofuran, etc. are mentioned. These can be used individually or in combination of 2 or more types.

On the other hand, it is more preferable that the urethane polymer contains a carboxyl group. When a carboxyl group is contained in a urethane polymer, it is because water dispersibility improves and the adhesiveness between an adhesive bond layer and a transparent film improves more.

The urethane polymer containing the carboxyl group can be obtained, for example, by reacting a chain extender having a free carboxyl group in addition to the polyol and polyisocyanate. The chain extender which has a carboxyl group is dihydroxy carboxylic acid, dihydroxy succinic acid, etc. are mentioned. Examples of the dihydroxy carboxylic acid include dialkylol alkanoic acid including dimethylol alkanoic acid such as dimethylol acetic acid, dimethylol butanoic acid, dimethylol propionic acid, dimethylol butyric acid and dimethylolpentanoic acid. These can be used individually or in combination of 2 or more types.

Meanwhile, the content of the urethane polymer is about 1 to 50 parts by weight, more preferably about 3 to 20 parts by weight, and most preferably about 5 to 15 parts by weight based on 100 parts by weight of the primer composition. When the urethane polymer is included in less than 1 part by weight with respect to 100 parts by weight of the primer composition, the adhesiveness is lowered. When the urethane polymer is contained in an amount exceeding 30 parts by weight, the viscosity is high, so that there is a problem that the drying time is long without becoming leveling during coating.

In addition, the weight average molecular weight of the urethane polymer is preferably in the range of 10,000 to 100,000, the molecular weight is less than 10,000 there is a decrease in the adhesive strength, if more than 100,000 is difficult to produce a water-dispersed urethane.

Next, the water-dispersible fine particles that can be used in the present invention can use any suitable fine particles, preferably water-dispersible fine particles. Specifically, inorganic fine particles. All organic fine particles can be used. Examples of the inorganic fine particles include inorganic oxides such as silica, titania, alumina, zirconia, antimony and the like. Examples of the organic fine particles include silicone resins, fluorine resins, (meth) acrylic resins, crosslinked polyvinyl alcohols, melamine resins, and the like.

Among the above water-dispersible fine particles, silica is preferably used, and since silica is more excellent in blocking inhibition ability and excellent in transparency, it does not generate haze and there is no coloration, and thus the influence on the optical properties of the polarizing plate is smaller. In addition, since silica has good dispersibility and dispersion stability with respect to the primer composition, the workability at the time of forming the primer layer may be more excellent.

The average diameter (average primary particle diameter) of the water-dispersible fine particles is preferably 10 to 200 nm, more preferably 20 to 70 nm. When the average diameter of the water-dispersible fine particles is smaller than 10 nm, the surface energy is increased, so that agglomeration of silica may occur in the primer solution and precipitation may cause a problem of the stability of the solution. When the particles are agglomerated due to uneven dispersion, the particles become larger than the visible light (400 nm to 800 nm) wavelengths, scattering light of 400 nm or more and causing haze to rise. By using fine particles having a particle diameter in the above range, irregularities are appropriately formed on the surface of the primer layer, and in particular, the frictional force on the contact surface between the acrylic film and the primer layer and / or the primer layers can be effectively reduced. As a result, the blocking inhibiting ability can be further excellent.

On the other hand, the content of the water-dispersible fine particles is preferably about 0.1 to 10 parts by weight based on 100 parts by weight of the primer composition. When the content of the water-dispersible fine particles is less than 0.1 part by weight, the film may not break due to slip between films during winding. If it exceeds 10 parts by weight, haze may occur.

Since the primer composition of the present invention is water-based, the fine particles are preferably blended into an aqueous dispersion. Specifically, when silica is used as the fine particles, it is preferably blended as colloidal silica. As a colloidal silica, the product marketed in the said technical field can be used as it is, For example, Snowtex series of Nissan Chemical Industries, Ltd., AEROSIL series of Air Products, the epostar series of Japan Catalyst, and the soliostar RA series, Ranco LSH series and the like can be used.

On the other hand, the primer composition, if necessary, may further comprise a crosslinking agent. As the crosslinking agent, methylol compounds such as oxazoline, boric acid, trimethylolmelamine, carbodiimide, isocyanate, aziridine compound and the like can be used.

The crosslinking agent is preferably included in an amount of 0.1 to 30 parts by weight based on 100 parts by weight of the primer composition. In the case of using a primer including a crosslinking agent, the primer layer prevents water penetration and thus exhibits excellent optical properties such as water resistance and heat resistance.

In addition, the primer composition may further include a silane coupling agent, a fluorine-based surfactant, a silane-based surfactant, and a surfactant including an alkyl group, as needed.

On the other hand, the primer layer formed by the primer composition as described above is preferably about 100nm to 1㎛ thickness. If the primer layer is less than 100nm, the adhesion decreases, and when the primer layer is 1 μm or more, the coating may be broken due to poor drying during primer coating.

Further, the water contact angle of the surface of the primer layer of the present invention is preferably 40 to 100 degrees, more preferably 50 to 90 degrees, still more preferably 60 to 80 degrees. If the water contact angle is less than 40 degrees, since the hydrophilicity of the primer layer is strong, it may react with the iodine of the polarizer to inhibit the iodine arrangement, resulting in the discoloration of the group color and the polarization degree. If the water contact angle exceeds 100 degrees, the primer layer The hydrophobicity of is so strong that adhesion with the polarizer is difficult.

Next, the first transparent film and the second transparent film as a compensation film for compensating the optical properties of the polarizer protective film or polarizer, a polymer film known in the art may be used. Meanwhile, films of the same material may be used as the first transparent film and the second transparent film, and films of different materials may be used.

More specifically, but not limited thereto, the transparent film may be, for example, acrylic film, PET film, acrylic primer treated PET film, polynorbornene (PNB) film, COP film, polycarbonate film and NRT ( FUJIFILM), N TAC (Konica), V TAC (FUJIFILM), and UZ TAC (FUJIFILM) including at least one selected from the group consisting of a film. Among these, it is especially preferable that it is an acryl-type film.

In the present invention, the acrylic film used as the transparent film may contain a (meth) acrylate resin. The film containing the (meth) acrylate-based resin can be obtained, for example, by molding a molding material containing (meth) acrylate-based resin as a main component by extrusion molding.

The acryl-based film is a film comprising an alkyl (meth) acrylate-based unit and a copolymer containing a styrene-based unit, and an aromatic resin having a carbonate portion in the main chain, or an alkyl (meth) acrylate-based unit, a styrene-based unit, It may be a film comprising a 3 to 6 membered hetero ring unit substituted with at least one carbonyl group and a vinyl cyanide unit.

Alternatively, the acrylic film may be a film including a (meth) acrylate resin having an aromatic ring. Examples of the (meth) acrylate-based resin having an aromatic ring include (a) (meth) acrylate-based units comprising (a) one or more (meth) acrylate-based derivatives described in Korean Patent Laid-Open Publication No. 10-2009-0115040; (b) an aromatic unit having a chain having an hydroxy group containing portion and an aromatic moiety; And (c) a styrene-based unit containing at least one styrene-based derivative. The units (a) to (c) may each be included in the resin composition in the form of a separate copolymer, and two or more units of the units (a) to (c) may be included in the resin composition in the form of one copolymer. have.

Alternatively, the acrylic film may be a film including an acrylic resin having a lactone ring structure. As a specific example of (meth) acrylate type resin which has a lactone ring structure, it is the lactone described, for example in Unexamined-Japanese-Patent No. 2000-230016, Unexamined-Japanese-Patent No. 2001-151814, 2002-120326, etc. (Meth) acrylate type resin which has a ring structure is mentioned.

The method for producing the acrylic film is not particularly limited, and for example, (meth) acrylate resin and other polymers, additives, etc. are sufficiently mixed by any suitable mixing method to prepare a thermoplastic resin composition, which is then film-molded. Or (meth) acrylate-based resin and other polymers, additives and the like may be prepared in a separate solution and then mixed to form a uniform mixed solution and then film-molded.

The thermoplastic resin composition is prepared by, for example, extrusion kneading the resulting mixture after preblending the film raw material with an appropriate mixer such as an omni mixer. In this case, the mixer used for extrusion kneading is not specifically limited, For example, arbitrary appropriate mixers, such as an extruder, such as a single screw extruder and a twin screw extruder, and a pressurized kneader, can be used.

As a method of the said film shaping | molding, arbitrary suitable film shaping | molding methods, such as the solution casting method (solution casting method), the melt extrusion method, the calender method, the compression molding method, are mentioned, for example. Among these film forming methods, a solution cast method (solution casting method) and a melt extrusion method are preferable.

As a solvent used for the said solution casting method (solution casting method), For example, aromatic hydrocarbons, such as benzene, toluene, xylene; Aliphatic hydrocarbons such as cyclohexane and decalin; Esters such as ethyl acetate and butyl acetate; Ketones such as acetone, methyl ethyl ketone and methyl isobutyl ketone; Alcohols such as methanol, ethanol, isopropanol, butanol, isobutanol, methyl cellosolve, ethyl cellosolve and butyl cellosolve; Ethers such as tetrahydrofuran and dioxane; Halogenated hydrocarbons such as dichloromethane, chloroform and carbon tetrachloride; Dimethylformamide; Dimethyl sulfoxide, etc. are mentioned. These solvents may be used independently or may use 2 or more types together.

As an apparatus for performing the said solution casting method (solution casting method), a drum type casting machine, a band type casting machine, a spin coater, etc. are mentioned, for example. Examples of the melt extrusion method include a T-die method and an inflation method. Molding temperature becomes like this. Preferably it is 150-350 degreeC, More preferably, it is 200-300 degreeC.

When forming a film by the said T-die method, a T die can be attached to the front-end | tip of a well-known single screw extruder or a twin screw extruder, the film extruded in film shape can be rolled, and a roll-shaped film can be obtained. Under the present circumstances, you may uniaxially stretch by adjusting the temperature of a winding roll suitably and extending | stretching in an extrusion direction. Moreover, simultaneous biaxial stretching, sequential biaxial stretching, etc. can also be performed by extending | stretching a film in the direction perpendicular | vertical to an extrusion direction.

The acrylic film may be any of an unstretched film or a stretched film. In the case of a stretched film, it may be a uniaxial stretched film or a biaxially stretched film, and in the case of a biaxially stretched film, it may be either a simultaneous biaxially stretched film or a successive biaxially stretched film. In the case of biaxial stretching, the mechanical strength is improved and the film performance is improved. By mixing another thermoplastic resin, an acryl-type film can suppress an increase of retardation even when extending | stretching, and can maintain optical isotropy.

It is preferable that extending | stretching temperature is a range near the glass transition temperature of the thermoplastic resin composition which is a film raw material, Preferably it is (glass transition temperature -30 degreeC)-(glass transition temperature +100 degreeC), More preferably, it is (glass transition Temperature -20 ° C) to (glass transition temperature + 80 ° C). If the stretching temperature is less than (glass transition temperature -30 ° C), there is a fear that a sufficient stretching ratio may not be obtained. On the contrary, when extending | stretching temperature exceeds (glass transition temperature +100 degreeC), the flow (flow) of a resin composition arises and there exists a possibility of not being able to perform stable extending | stretching.

The draw ratio defined by area ratio becomes like this. Preferably it is 1.1-25 times, More preferably, it is 1.3-10 times. If the draw ratio is less than 1.1 times, there is a fear that it does not lead to the improvement of the toughness accompanying stretching. When a draw ratio exceeds 25 times, there exists a possibility that the effect by raising a draw ratio may not be recognized.

The stretching speed is preferably 10 to 20,000% / min, more preferably 100 to 10,000% / min in one direction. If the stretching speed is less than 10% / min, it takes a long time to obtain a sufficient draw ratio, there is a fear that the manufacturing cost increases. When the stretching speed exceeds 20,000% / min, breakage of the stretched film may occur.

The acrylic film may be subjected to heat treatment (annealing) or the like after the stretching treatment in order to stabilize its optical isotropy and mechanical properties. The heat treatment conditions are not particularly limited and may employ any suitable conditions known in the art.

On the other hand, the transparent film may be subjected to a surface treatment for improving the adhesion if necessary, for example, at least one surface treatment selected from the group consisting of alkali treatment, corona treatment, and plasma treatment on at least one surface of the optical film. Can be performed.

In the polarizing plate according to the present invention as described above, for example, one side of the transparent film is coated with a primer composition to form a primer layer, and the adhesive layer is formed by applying an adhesive composition to one side of the primer layer or polarizer, and then a polarizer and a transparent layer. After the film is laminated, it may be prepared by a method of curing the adhesive composition through light irradiation.

The polarizing plate of the present invention as described above can be usefully applied to an optical device such as a liquid crystal display device. For example, the optical device of the present invention may be a liquid crystal display including a liquid crystal panel and polarizing plates provided on both sides of the liquid crystal panel, wherein at least one of the polarizing plates may be a polarizing plate according to the present invention. . At this time, the type of liquid crystal panel included in the liquid crystal display device is not particularly limited. For example, a panel of a passive matrix type such as, but not limited to, a twisted nematic (TN) type, a super twisted nematic (STN) type, a ferrolectic (F) type, or a polymer dispersed (PD) type; Active matrix panels such as two-terminal or three-terminal; All known panels, such as an In Plane Switching (IPS) panel and a Vertical Alignment (VA) panel, can be applied. In addition, other configurations constituting the liquid crystal display device, 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. Can be.

Hereinafter, the present invention will be described in more detail with reference to Examples. However, the following examples are intended to illustrate the present invention, and the scope of the present invention is not limited by the following examples.

Preparation Example 1 Preparation of Transparent Film

The raw material hopper is a resin composition obtained by uniformly mixing poly (N-cyclohexylmaleimide-co-methylmethacrylate), styrene-maleic anhydride copolymer resin and phenoxy resin in a weight ratio of 100: 2.5: 5. From the extruder to a nitrogen-substituted 24φ extruder and melted at 250 ° C. to prepare a raw material pellet.

The phenoxy resin was PKFE (Mw = 60,000, Mn = 16,000, Tg = 95 ° C) manufactured by InChemRez®, and Dylaeck styrene-maleic anhydride copolymer resin was 85 wt% of styrene and 15 wt% of maleic anhydride. 332 was used, and the poly (N-cyclohexylmaleimide-co-methylmethacrylate) resin had a content of N-cyclohexylmaleimide of 6.5 wt% based on NMR analysis.

The obtained raw material pellets were vacuum-dried and melted with an extruder at 260 degreeC, passed through the T-die of a coat hanger type, and the film of 150 micrometers in thickness was produced through the chrome plating casting roll, a drying roll, etc. The film was stretched at a rate of 170% using a speed difference of the roll in the MD direction at 125 ° C. using a pilot stretching equipment to produce an acrylic film.

(1) Acrylic film (A) manufacture

After corona treatment of the acrylic film prepared through the above process, carbodii to a primer composition of 10% by weight of solid content prepared by diluting CK-PUD-F (dilute urethane dispersion) with pure water on one surface of the acrylic film. After coating the primer composition to which 10 parts by weight of the mid-based crosslinking agent (manufactured by Nishinbo Corporation, Carbodilite SV-02) was added with # 7 bar, the primer layer was stretched by 190% using a tender at 130 ° C in the TD direction. An acrylic film (A) having a thickness of 400 nm was prepared.

(2) acrylic film (B) manufacture

After the corona treatment of the acrylic film prepared in Preparation Example 1 (1), the oxazoline crosslinking agent was added to a primer composition having a solid content of 10% by weight by diluting CK-PUD-F (lighting urethane dispersion) thereon with pure water. (Japan Catalyst Co., Ltd., WS700) After directly coating # 7 of the primer composition to which 20 parts by weight was added, an acrylic film (B) having a primer layer thickness of 400 nm was prepared by stretching 190% using a tender at 130 ° C. in the TD direction.

Preparation Example 2 Preparation of Adhesive Composition

(1) Adhesive Composition A

25% by weight of 3,4-epoxycyclohexylmethyl-3,4'-epoxycyclohexanecarboxylate (Celloxide 2021P from Dicel), 25% by weight of 1,4-cyclohexane dimethanol diglycidyl ether, 3-ethyl- 35% by weight of 3-[(3-ethyloxetane-3-yl) methoxymethyl] oxetane (Doagosei Aaron Oxetane DOX221) and 3-ethyl-3-hydroxymethyloxetane (Doagosei Aaron Oxetane OXA 5 parts by weight of CPI 100P (Sanapro), which is a cationic initiator, was added to 100 parts by weight of the resin composition prepared by adding 15% by weight of the adhesive composition A for a polarizing plate.

 (2) Adhesive Composition B

25% by weight of 3,4-epoxycyclohexylmethyl-3,4'-epoxycyclohexanecarboxylate (Celloxide 2021P from Dicel), 25% by weight of 1,4-cyclohexane dimethanol diglycidyl ether, 3-ethyl- 50 parts by weight of 3-[(3-ethyloxetan-3-yl) methoxymethyl] oxetane (Doagosei Aaron oxetane DOX221) was added to 100 parts by weight of the resin composition, prepared by CPI 100P as a cationic initiator (Sanapro). 5 weight part and 5 weight part of vinyl triethylsilanes were added, and the adhesive composition B for polarizing plates was produced.

.

(3) Adhesive Composition C

25% by weight of 3,4-epoxycyclohexylmethyl-3,4'-epoxycyclohexanecarboxylate (Celloxide 2021P from Dicel), 25% by weight of 1,4-cyclohexane dimethanol diglycidyl ether, 3-ethyl- 50 parts by weight of 3-[(3-ethyloxetan-3-yl) methoxymethyl] oxetane (Doagosei Aaron oxetane DOX221) was added to 100 parts by weight of the resin composition, prepared by CPI 100P as a cationic initiator (Sanapro). 5 weight part and 5 weight part of vinyl acetate were added, and the adhesive composition C for polarizing plates was produced.

Example 1

Using a microgravure coater, the adhesive composition A was applied onto the primer layer of two acrylic films (A) prepared in Preparation Example 1 so that the final adhesive layer thickness was 1 μm. Then, two acrylic films (A) coated with an adhesive composition were laminated on both sides of the PVA device, and UV light of 500 mJ / cm ² was emitted from one side of the PVA device using a UV halo lamp (metal halide lamp). It irradiated and manufactured the polarizing plate.

Example 2

A polarizing plate was manufactured in the same manner as in Example 1 except that B was used as the adhesive composition.

Example 3

A polarizing plate was manufactured in the same manner as in Example 1, except that C was used as the adhesive composition.

Example 4

A polarizing plate was manufactured in the same manner as in Example 1 except that the adhesive layer was coated with a thickness of 3 μm.

Example 5

A polarizing plate was manufactured in the same manner as in Example 2, except that the adhesive layer was coated with a thickness of 3 μm.

Example 6

A polarizing plate was manufactured in the same manner as in Example 3 except that the adhesive layer was coated with a thickness of 3 μm.

Example 7

The adhesive composition A was coated on the primer layer of the acrylic film A prepared in Preparation Example 1 using a microgravure coater so that the final adhesive layer thickness was 1 μm (hereinafter referred to as acrylic film A-1). box). In addition, the adhesive composition A was coated on the primer layer of the acrylic film prepared according to Preparation Example 1 using a microgravure coater so that the final adhesive layer thickness was 3 μm (hereinafter referred to as acrylic film (A-2)). ). The acrylic film (A-1) and the acrylic film (A-2) are laminated on both sides of the PVA device, and 500mJ on the surface where the acrylic film (A-2) is laminated using a UV irradiation device (Metal halide lamp). Ultraviolet rays of / cm ² were irradiated to prepare a polarizing plate.

Example 8

The adhesive composition A was coated on the primer layer of the acrylic film A prepared in Preparation Example 1 using a microgravure coater so that the final adhesive layer thickness was 3 μm (hereinafter referred to as acrylic film A-3). box). In addition, the adhesive composition A was coated on the primer layer of the acrylic film (A) prepared in Preparation Example 1 using a microgravure coater so that the final adhesive layer thickness was 10 μm (hereinafter, an acrylic film (A-4 )). The acrylic film (A-3) and the acrylic film (A-4) are laminated on both sides of the PVA device, and 500mJ on the surface where the acrylic film (A-4) is laminated using a UV halo lamp (metal halide lamp). Ultraviolet rays of / cm ² were irradiated to prepare a polarizing plate.

Example 9

The adhesive composition A was coated on the primer layer of the acrylic film (B) prepared in Preparation Example 1 using a microgravure coater so that the final adhesive layer thickness was 1 μm (hereinafter referred to as acrylic film (B-1)). box). In addition, the adhesive composition A was coated on the primer layer of the acrylic film prepared according to Preparation Example 1 using a microgravure coater so that the final adhesive layer thickness was 3 μm (hereinafter referred to as acrylic film (B-2)). ). The acrylic film (B-1) and the acrylic film (B-2) are laminated on both sides of the PVA device, and 500mJ on the surface where the acrylic film (B-2) is laminated using a UV halo lamp (metal halide lamp). Ultraviolet rays of / cm ² were irradiated to prepare a polarizing plate.

Comparative Example 1

A polarizing plate was manufactured in the same manner as in Example 1 except that the adhesive layer was coated with a thickness of 5 μm.

Comparative Example 2

A polarizing plate was manufactured in the same manner as in Example 2, except that the adhesive layer was coated with a thickness of 5 μm.

Comparative Example 3

A polarizing plate was manufactured in the same manner as in Example 3, except that the adhesive layer was coated with a thickness of 5 μm.

Experimental Example 1: Evaluation of Peeling Force of Polarizing Plate

The peeling force of the 1st adhesive bond layer was measured about the polarizing plates manufactured by Examples 1-9 and Comparative Examples 1-3. Peeling force was measured by the peeling force at the time of peeling an acrylic film of a PVA element and an ultraviolet non-irradiation surface at a speed | rate of 300 mm / min and 90 degree using the polarizing plate of 20 mm in width and 100 mm in length. The results are shown in Table 1 below. The case where peeling force exceeds 2 N / cm is OK, and the case where it is 2 N / cm or less is represented by NG.

Experimental Example 2: Evaluation of Water Resistance

The polarizing plates of Examples 1 to 9 and Comparative Examples 1 to 3 were laminated on a glass substrate, and then immersed in a 60 ° C thermostat. After 8 hours, the water resistance was judged by the discoloration of the ends of the polarizing plate, and the case where there was no deformation was OK and the case where the discoloration occurred was indicated by NG.

Experimental Example 3: Evaluation of Thermal Shock Properties

After laminating the polarizing plates prepared in Examples 1 to 9 and Comparative Examples 1 to 3 to a glass substrate, leaving them at -40 ° C for 30 minutes, and leaving them at 80 ° C for 30 minutes again. 100 repetitions were performed. Then, visual evaluation of the deformation of the polarizing plate appearance. The case where the external appearance of a polarizing plate does not have a deformation | transformation was OK, and the case where a crack generate | occur | produced was represented by NG. The results are shown in Table 2 below.

TABLE 2

division	primer		glue	First adhesive layer thickness [㎛]	2nd adhesive layer thickness [㎛]	1st adhesive layer peel force	Water resistance	Thermal shock
	UV irradiation surface	UV irradiated surface
Example 1	CkPUD F + SV-02 10 parts by weight	CkPUD F + SV-02 10 parts by weight	A	One	One	OK	OK	OK
Example 2	CkPUD F + SV-02 10 parts by weight	CkPUD F + SV-02 10 parts by weight	B	One	One	OK	OK	OK
Example 3	CkPUD F + SV-02 10 parts by weight	CkPUD F + SV-02 10 parts by weight	C	One	One	OK	OK	OK
Example 4	CkPUD F + SV-02 10 parts by weight	CkPUD F + SV-02 10 parts by weight	A	3	3	OK	OK	OK
Example 5	CkPUD F + SV-02 10 parts by weight	CkPUD F + SV-02 10 parts by weight	B	3	3	OK	OK	OK
Example 6	CkPUD F + SV-02 10 parts by weight	CkPUD F + SV-02 10 parts by weight	C	3	3	OK	OK	OK
Example 7	CkPUD F + SV-02 10 parts by weight	CkPUD F + SV-02 10 parts by weight	A	One	3	OK	OK	OK
Example 8	CkPUD F + SV-02 10 parts by weight	CkPUD F + SV-02 10 parts by weight	A	3	10	OK	OK	OK
Example 9	CkPUD F + WS700 20 parts by weight	CkPUD F + WS70020 weight part	A	One	3	OK	OK	OK
Comparative Example 1	CkPUD F + SV-02 10 parts by weight	10 parts by weight of PUD F + SV-02	A	5	5	NG	OK	OK
Comparative Example 2	CkPUD F + SV-02 10 parts by weight	10 parts by weight of PUD F + SV-02	B	5	5	NG	OK	OK
Comparative Example 3	CkPUD F + SV-02 10 parts by weight	10 parts by weight of PUD F + SV-02	C	5	5	NG	OK	OK

Claims (14)

1. A polarizer, a first adhesive layer formed on one surface of the polarizer, a second adhesive layer formed on the other surface of the polarizer, a first transparent film formed on the first adhesive layer, and a second adhesive layer formed on the second adhesive layer Double-sided polarizing plate containing a transparent film,

   The first adhesive layer and the second adhesive layer is formed by an active energy ray curable adhesive,

   A double-sided polarizing plate having a thickness of the first adhesive layer is 0.1 to 3㎛.
2. The method of claim 1,

   A double-sided polarizing plate having a thickness of the second adhesive layer is 0.1 to 10㎛.
3. The method of claim 1,

   The double-sided polarizing plate is prepared by simultaneously curing the first adhesive layer and the second adhesive layer by one active energy ray irradiation.
4. The method of claim 3,

   The active energy ray irradiation is performed via an energy source located in the direction of the transparent film formed on the second adhesive layer.
5. The method of claim 1,

   The first adhesive layer and the second adhesive layer is a double-sided polarizing plate is formed by a cationic adhesive.
6. The method of claim 5,

   The cationic adhesive is (1) 5 to 90 parts by weight of an epoxy compound having at least two epoxy groups in the molecule; (2) 5 to 90 parts by weight of an oxetane compound having at least one oxetanyl group in the molecule; And (3) 0.5 to 20 parts by weight of the photocationic polymerization initiator.
7. The method of claim 6,

   Wherein said epoxy compound is a combination of a first epoxy compound comprising at least one epoxidized aliphatic ring group and a second epoxy compound comprising at least one glycidyl ether group.
8. The method of claim 6,

   The cationic adhesive further comprises one or more selected from the group consisting of a silane coupling agent, a vinyl compound and a radical polymerizable monomer.
9. The method of claim 1,

   The double-sided polarizing plate further comprises a primer layer between at least one of the first adhesive layer and the first transparent film and between the second adhesive layer and the second transparent film.
10. The method according to claim 9,

    The primer layer is formed by a primer composition comprising 1 to 50 parts by weight of a urethane polymer, and 0.1 to 10 parts by weight of water-dispersible fine particles and the balance of water.
11. The method of claim 10,

    The primer composition further comprises a crosslinking agent.
12. The method of claim 9,

    The primer layer is a double-sided polarizing plate having a thickness of 100nm to 1㎛.
13. The method of claim 1,

    At least one of the first transparent film and the second transparent film is a double-sided polarizing plate is an acrylic film.
14. An optical device comprising the double-sided polarizing plate of claim 1.