KR20170117556A - Liquid crystal panel and image display device - Google Patents

Abstract

The present invention provides a liquid crystal panel including a liquid crystal cell having a transparent conductive layer on one surface thereof, which can improve the durability of the liquid crystal panel as a whole and can suppress panel warping and light leakage . Another object of the present invention is to provide an image display apparatus using the liquid crystal panel.
A transparent conductive layer is formed on one surface of the liquid crystal cell. A first polarizing film is bonded onto the transparent conductive layer via a first pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition (A1) Wherein the pressure-sensitive adhesive composition (A1) is a liquid crystal panel in which a second polarizing film is bonded via a second pressure-sensitive adhesive layer formed from a pressure-sensitive adhesive composition (A2) Wherein the pressure-sensitive adhesive composition (A2) comprises a (meth) acryl-based polymer (a2) and a thiol group-containing silane coupling agent, wherein the gel fraction of the first pressure- Or less, and further satisfies the following formula (1).

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a liquid crystal panel and an image display device,

The present invention relates to a liquid crystal panel and an image display apparatus using the liquid crystal panel.

In a liquid crystal panel used in a liquid crystal display device or the like, a polarizing film is laminated on both sides of a liquid crystal cell formed of a liquid crystal layer disposed between a pair of transparent substrates with an adhesive layer interposed therebetween. Such a pressure-sensitive adhesive layer is required to have high durability. For example, in the durability test by heating, humidification or the like, which is usually conducted as an environmental promotion test, it is required that no problems such as peeling or lifting due to the pressure- do.

Such pressure-sensitive adhesive compositions for optical use have been studied variously, and for example, there has been proposed a pressure-sensitive adhesive composition which does not cause peeling or foaming even when the optical film is adhered (adhered) under high-humidity heat conditions See, for example, Patent Document 1).

Japanese Laid-Open Patent Publication No. 2009-242767

A transparent conductive film such as an indium tin oxide (ITO) thin film is formed on one of the transparent substrates of the liquid crystal cell constituting the liquid crystal panel. The pressure sensitive adhesive layer in contact with the transparent conductive film is in contact with a transparent substrate such as a glass substrate The pressure-sensitive adhesive layer is liable to be peeled off or peeled off, and the durability tends to be lowered. The pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition of Patent Document 1 is poor in adhesion to the indium tin oxide (ITO) layer, and the pressure-sensitive adhesive composition for a liquid crystal panel having a transparent conductive layer is not sufficient.

As described above, a transparent conductive film such as an ITO thin film is formed on one of the transparent substrates of the liquid crystal cell, and the other is a transparent substrate such as a glass substrate, and properties of both surfaces of the liquid crystal cell are often different. There has been a problem in that it is difficult to maintain the durability of the liquid crystal panel as a whole by maintaining the durability not causing foaming or peeling on both sides of the liquid crystal cell. In Patent Document 1, the relationship with an adherend such as a liquid crystal cell is not specified at all, and thus, the durability of the entire liquid crystal panel is not sufficient.

 In recent years, the thickness of the liquid crystal panel has been demanded. However, when the liquid crystal panel is made thin, the panel may be warped. When the warpage of the panel becomes large, there arises a problem that the display image becomes uneven due to the contact between the liquid crystal panel and the casing of the display, or the double-sided tape fixing the backlight to the liquid crystal panel peels off. In addition, although the peripheral area of the liquid crystal display device is made narrower to increase the area ratio of the display area in the display device (narrower frame), the width of the shielded peripheral area outside the display area The end portion of the polarizing film reaches the inside of the display region due to the shrinkage of the polarizing film and light leakage occurs in the peripheral portion of the display region in some cases. In recent years, as the liquid crystal panel has been made thinner and narrower frames, the demand for preventing the panel from being warped and for light leakage has been increased.

Therefore, it is an object of the present invention to provide a liquid crystal panel including a liquid crystal cell having a transparent conductive layer on one surface thereof, which can improve the durability of the liquid crystal panel as a whole, And to provide the above objects. Another object of the present invention is to provide an image display apparatus using the liquid crystal panel.

As a result of intensive investigations to solve the above problems, the present inventors have found out the following liquid crystal panel and have completed the present invention.

That is, the present invention provides a liquid crystal display device, wherein a transparent conductive layer is formed on one surface of a liquid crystal cell, and a first polarizing film is formed on the transparent conductive layer via a first adhesive layer formed from the adhesive composition (A1) And a second polarizing film is bonded to the other surface of the liquid crystal cell via a second pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition (A2)

The pressure-sensitive adhesive composition (A1) comprises a (meth) acrylic polymer (a1) and an epoxy group-containing silane coupling agent,

The pressure-sensitive adhesive composition (A2) comprises a (meth) acrylic polymer (a2) and a thiol group-containing silane coupling agent,

Wherein the gel fraction of the first pressure-sensitive adhesive layer and the second pressure-sensitive adhesive layer is 65% or more and 90% or less, and further satisfies the following formula (1).

It is preferable that the epoxy group-containing silane coupling agent is an oligomer-type epoxy group-containing silane coupling agent having at least two alkoxysilyl groups in the molecule.

It is preferable that the thiol group-containing silane coupling agent is an oligomer-type thiol group-containing silane coupling agent having at least two alkoxysilyl groups in the molecule.

The blending amount of the epoxy group-containing silane coupling agent is preferably 0.001 to 5 parts by weight based on 100 parts by weight of the (meth) acryl-based polymer (a1).

It is preferable that the blending amount of the thiol group-containing silane coupling agent is 0.001 to 5 parts by weight based on 100 parts by weight of the (meth) acrylic polymer (a2).

It is preferable that the (meth) acryl-based polymer (a1) and / or (a2) contains 0.01 to 2% by weight of a carboxyl group-containing monomer as a monomer unit.

It is preferable that the (meth) acryl-based polymer (a1) and / or (a2) contains 0.1 to 8% by weight of an amide group-containing monomer as a monomer unit.

It is preferable that the (meth) acryl-based polymer (a1) and / or (a2) contains 0.01 to 7% by weight of a monomer containing a hydroxyl group as a monomer unit.

It is preferable that the pressure-sensitive adhesive composition (A1) and / or the pressure-sensitive adhesive composition (A2) contain at least one crosslinking agent selected from the group consisting of an isocyanate crosslinking agent and a peroxide crosslinking agent.

The present invention also relates to an image display apparatus using the liquid crystal panel.

In the present invention, a first polarizing film is disposed on a transparent conductive layer surface on one surface of a liquid crystal cell via a first pressure-sensitive adhesive layer formed from a specific pressure-sensitive adhesive composition (A1) The durability as a whole liquid crystal panel can be improved by disposing the second polarizing film through the second pressure sensitive adhesive layer formed from the pressure sensitive adhesive composition (A2) and controlling the gel fraction of the first pressure sensitive adhesive layer and the second pressure sensitive adhesive layer And it is possible to suppress panel warpage and light leakage.

1 is a cross-sectional view schematically showing an embodiment of a liquid crystal panel of the present invention.

1. Liquid crystal panel

In the liquid crystal panel of the present invention, the transparent conductive layer is formed on one surface of the liquid crystal cell, and the first polarizing film is bonded onto the transparent conductive layer via the first pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition (A1) , And a second polarizing film is bonded to the other surface of the liquid crystal cell via a second pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition (A2)

The pressure-sensitive adhesive composition (A1) comprises a (meth) acrylic polymer (a1) and an epoxy group-containing silane coupling agent,

The pressure-sensitive adhesive composition (A2) comprises a (meth) acrylic polymer (a2) and a thiol group-containing silane coupling agent,

Wherein the gel fraction of the first pressure-sensitive adhesive layer and the second pressure-sensitive adhesive layer is 65% or more and 90% or less, and further satisfies the following formula (1).

(1) Pressure-Sensitive Adhesive Composition (A1)

The pressure-sensitive adhesive composition (A1) used in the present invention comprises a (meth) acryl-based polymer (a1) and an epoxy group-containing silane coupling agent, and preferably contains a (meth) acrylic polymer (a1) as a main component. Here, the main component means a component having the largest content ratio among all the solid components contained in the pressure-sensitive adhesive composition (A1), for example, a component that occupies most of the total solid content in the pressure-sensitive adhesive composition (A1) By weight and more than 70% by weight.

The (meth) acrylic polymer (a1) usually contains, as a monomer unit, an alkyl (meth) acrylate as a main component. Further, (meth) acrylate refers to acrylate and / or methacrylate and has the same meaning as (meth) acrylate of the present invention.

As the alkyl (meth) acrylate constituting the main skeleton of the (meth) acrylic polymer (a1), those having 1 to 18 carbon atoms in the linear or branched alkyl group can be exemplified. Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, an amyl group, a hexyl group, a cyclohexyl group, a heptyl group, a 2-ethylhexyl group, A heptyl group, a heptyl group, a heptyl group, a heptyl group, a heptyl group, a heptyl group, a heptyl group, a heptyl group, a heptyl group, a heptyl group, These can be used alone or in combination. The average number of carbon atoms of these alkyl groups is preferably from 3 to 9.

Examples of the monomer constituting the (meth) acrylic polymer (a1) include monomers having a carboxyl group, hydroxyl group-containing monomers, amide group-containing monomers and aromatic ring-containing (meth) .

The carboxyl group-containing monomer is a compound containing a carboxyl group in its structure and containing a polymerizable unsaturated double bond such as a (meth) acryloyl group or a vinyl group. Specific examples of the carboxyl group-containing monomers include (meth) acrylic acid, carboxyethyl (meth) acrylate, carboxypentyl (meth) acrylate, itaconic acid, maleic acid, fumaric acid and crotonic acid . Among the above-mentioned carboxyl group-containing monomers, acrylic acid is preferable from the viewpoint of copolymerization, cost, and adhesive property.

The hydroxyl group-containing monomer is a compound containing a hydroxyl group in its structure and containing a polymerizable unsaturated double bond such as a (meth) acryloyl group or a vinyl group. Specific examples of the hydroxyl group-containing monomer include, for example, 2-hydroxyethyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) (Meth) acrylate such as hydroxyhexyl (meth) acrylate, 8-hydroxyoctyl (meth) acrylate, 10-hydroxydecyl (meth) acrylate and 12- ) Acrylate and (4-hydroxymethylcyclohexyl) -methylacrylate. Among the hydroxyl group-containing monomers, 2-hydroxyethyl (meth) acrylate and 4-hydroxybutyl (meth) acrylate are preferable from the standpoint of durability, and 4-hydroxybutyl (meth) desirable.

The amide group-containing monomer is a compound containing an amide group in its structure and further containing a polymerizable unsaturated double bond such as a (meth) acryloyl group or a vinyl group. Specific examples of the amide group-containing monomer include (meth) acrylamide, N, N-dimethyl (meth) acrylamide, N, N-diethyl (meth) acrylamide, N-isopropylacrylamide, N-propyl (meth) acrylamide, N-methyl (meth) acrylamide, N-methyl Acrylamide monomers such as N- (meth) acrylamide, aminoethyl (meth) acrylamide, mercaptomethyl (meth) acrylamide and mercaptoethyl Acryloyl heterocyclic monomers such as (meth) acryloylpiperidine and N- (meth) acryloylpyrrolidine, N-vinylpyrrolidone such as N-vinylpyrrolidone and N-vinyl-epsilon -caprolactam Containing lactam-based monomer, and the like. The amide group-containing monomer is preferable for satisfying the durability, and among the amide group-containing monomers, the N-vinyl group-containing lactam monomer is particularly preferable for satisfying the durability to the transparent conductive layer.

The aromatic ring-containing (meth) acrylate is a compound containing an aromatic ring structure in its structure and further containing a (meth) acryloyl group. Examples of the aromatic ring include a benzene ring, a naphthalene ring, and a biphenyl ring. The aromatic ring-containing (meth) acrylate can satisfy the durability (particularly, the durability against the transparent conductive layer).

Specific examples of the aromatic ring-containing (meth) acrylate include benzyl (meth) acrylate, phenyl (meth) acrylate, o-phenylphenol (meth) acrylate, phenoxyethyl (Meth) acrylate, phenoxydiethylene glycol (meth) acrylate, ethylene oxide modified nonylphenol (meth) acrylate, ethylene oxide modified cresol (meth) acrylate, phenol ethylene oxide modified Having benzene rings such as 2-hydroxy-3-phenoxypropyl (meth) acrylate, methoxybenzyl (meth) acrylate, chlorobenzyl (meth) acrylate and polystyryl (meth) acrylate; Naphthalene (meth) acrylates such as 2-naphthyl (meth) acrylate, 2-naphthoyl (meth) acrylate, 2-naphthoxyethyl acrylate and 2- (4-methoxy-1-naphthoxy) ethyl The Those having; include those having a biphenyl ring, such as biphenyl (meth) acrylate.

As the aromatic ring-containing (meth) acrylate, benzyl (meth) acrylate and phenoxyethyl (meth) acrylate are preferable from the viewpoints of adhesion property and durability, and phenoxyethyl (meth) Do.

The carboxyl group-containing monomer, the hydroxyl group-containing monomer, the amide group-containing monomer and the aromatic ring-containing (meth) acrylate are reaction points with the crosslinking agent when the pressure-sensitive adhesive composition (A1) contains a crosslinking agent. In particular, carboxyl group-containing monomers and hydroxyl group-containing monomers are preferably used because they are rich in reactivity with an intermolecular crosslinking agent, and therefore, improve the cohesiveness and heat resistance of the resulting pressure-sensitive adhesive layer.

The (meth) acryl-based polymer (a1) used in the present invention preferably contains, as monomer units, the respective monomers in the following proportions by weight of the total constituent monomers (100% by weight).

The weight ratio of the alkyl (meth) acrylate can be set as the remainder of the monomer other than the alkyl (meth) acrylate. Specifically, it is preferably 70 wt% or more. It is preferable to set the weight ratio of alkyl (meth) acrylate to the above range in order to secure adhesiveness.

The weight ratio of the carboxyl group-containing monomer is preferably 2% by weight or less, more preferably 0.01 to 2% by weight, even more preferably 0.05 to 1.5% by weight, particularly preferably 0.05 to 1% by weight. When the weight ratio of the carboxyl group-containing monomer is less than 0.01% by weight, the durability tends not to be satisfied. On the other hand, if it exceeds 2% by weight, the transparent conductive layer may be corroded, which tends to be unsatisfactory in terms of durability, which is not preferable.

The weight ratio of the hydroxyl group-containing monomer is preferably 0.01 to 7% by weight, more preferably 0.01 to 5% by weight, further preferably 0.1 to 3% by weight, particularly preferably 0.2 to 2% by weight . When the weight ratio of the hydroxyl group-containing monomer is less than 0.01% by weight, the pressure-sensitive adhesive layer tends to undergo crosslinking and tends not to satisfy durability and adhesive properties. On the other hand, if it exceeds 5% by weight, durability tends not to be satisfied.

The proportion by weight of the amide group-containing monomer is preferably 8% by weight or less, more preferably 0.1 to 8% by weight, further preferably 0.3 to 5% by weight, further preferably 0.3 to 4% by weight, Particularly preferably 2.5% by weight. When the weight ratio of the amide group-containing monomer is less than 0.1% by weight, the durability to the transparent conductive layer tends not to be satisfied in particular. On the other hand, if it exceeds 8% by weight, durability tends to be lowered.

The weight ratio of the aromatic ring-containing (meth) acrylate is preferably 25% by weight or less, more preferably 0 to 22% by weight, and still more preferably 0 to 18% by weight. When the weight ratio of the aromatic ring-containing (meth) acrylate exceeds 25% by weight, the durability tends to be lowered.

In the (meth) acryl-based polymer (a1), it is not necessary to contain other monomer units in addition to the above-mentioned monomer units. In order to improve the adhesiveness and heat resistance, a (meth) acryloyl group or a vinyl group One or more kinds of copolymerizable monomers having a polymerizable functional group having an unsaturated double bond can be introduced by copolymerization.

Specific examples of such copolymerizable monomers include acid anhydride group-containing monomers such as maleic anhydride and itaconic anhydride; caprolactone adducts of acrylic acid; allylsulfonic acid, 2- (meth) acrylamide-2-methylpropanesulfonic acid, ) Sulfonic acid group-containing monomers such as acrylamide propane sulfonic acid and sulfopropyl (meth) acrylate; and phosphoric acid group-containing monomers such as 2-hydroxyethyl acryloyl phosphate.

Further, alkylaminoalkyl (meth) acrylates such as aminoethyl (meth) acrylate, N, N-dimethylaminoethyl (meth) acrylate and t- Acrylate such as N- (meth) acryloyloxymethylene succinimide or N- (meth) acryloyl-6-oxyhexamethylene succinimide such as ethoxyethyl (meth) Succinimide-based monomers such as N- (meth) acryloyl-8-oxyoctamethylene succinimide, N-cyclohexylmaleimide, N-isopropylmaleimide, N-laurylmaleimide, N- Maleimide-based monomers such as phenylmaleimide and the like; monomers such as N-methyl itaconimide, N-ethyl itaconimide, N-butyl itaconimide, N-octyl itaconimide, N-2-ethylhexyl itacon Itaconimide-based monomers such as imide, N-cyclohexyl itaconimide and N-lauryl itaconimide It can be given as examples of the monomers to be goals.

Examples of the modifying monomer include vinyl monomers such as vinyl acetate and vinyl propionate; cyanoacrylate monomers such as acrylonitrile and methacrylonitrile; epoxy group-containing (meth) acrylates such as glycidyl (meth) (Meth) acrylates such as polyethylene glycol (meth) acrylate, polypropylene glycol (meth) acrylate, methoxyethylene glycol (meth) acrylate and methoxypolypropylene glycol (meth) acrylate; (Meth) acrylate monomers such as furfuryl (meth) acrylate, fluorine (meth) acrylate, silicone (meth) acrylate and 2-methoxyethyl acrylate. Further, isoprene, butadiene, isobutylene, vinyl ether and the like can be mentioned.

Examples of the copolymerizable monomer other than the above include silane-based monomers containing a silicon atom. Examples of the silane-based monomer include 3-acryloxypropyltriethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, 4-vinylbutyltrimethoxysilane, 4-vinylbutyltriethoxysilane, Vinyl octyltrimethoxysilane, 8-vinyl octyltrimethoxysilane, 10-methacryloyloxydecyltrimethoxysilane, 10-acryloyloxydecyltrimethoxysilane, 10-methacryloyloxydecane Silyltriethoxysilane, 10-acryloyloxydecyltriethoxysilane, and the like.

Examples of the copolymerizable monomer include tripropylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, bisphenol A diglycidyl ether di Acrylate, trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol penta (Meth) acryloyl groups such as esters of (meth) acrylic acid and polyhydric alcohols such as dipentaerythritol hexa (meth) acrylate, dipentaerythritol hexa (meth) acrylate and caprolactone modified dipentaerythritol hexa A polyfunctional monomer having two or more unsaturated double bonds such as a vinyl group, and a (meth) acrylate as a functional group which is the same as the monomer component in the backbone of polyester, epoxy, As may be used in the group, the vinyl group or the like of two or unsaturated polyester (meth) adding at least a double bond acrylate, epoxy (meth) acrylate, urethane (meth) acrylate and the like.

The proportion of the copolymerizable monomer in the (meth) acrylic polymer (a1) is preferably about 0 to 10% by weight in terms of the weight ratio of the total constituent monomers (100% by weight) of the (meth) acrylic polymer , More preferably from 0 to 7% by weight, and still more preferably from 0 to 5% by weight.

The (meth) acryl-based polymer (a1) of the present invention usually has a weight average molecular weight of 1 million to 2.5 million. In consideration of durability, particularly heat resistance, the weight average molecular weight is preferably 1.2 to 2 million. If the weight average molecular weight is less than 1,000,000, it is not preferable from the viewpoint of heat resistance. On the other hand, if the weight-average molecular weight is larger than 2.5 million, the pressure-sensitive adhesive tends to be hard and tear easily occurs. The weight average molecular weight (Mw) / number average molecular weight (Mn) representing the molecular weight distribution is preferably from 1.8 to 10, more preferably from 1.8 to 7, and even more preferably from 1.8 to 5. When the molecular weight distribution (Mw / Mn) exceeds 10, it is not preferable from the viewpoint of durability. The weight average molecular weight and the molecular weight distribution (Mw / Mn) are determined by GPC (Gel Permeation Chromatography) and calculated from polystyrene conversion.

Such (meth) acrylic polymer (a1) can be suitably selected from known production methods such as solution polymerization, bulk polymerization, emulsion polymerization and various radical polymerization. The (meth) acryl-based polymer (a1) to be obtained may be any of a random copolymer, a block copolymer, a graft copolymer and the like.

In the solution polymerization, for example, ethyl acetate, toluene and the like are used as the polymerization solvent. As a specific example of the solution polymerization, the reaction is carried out under the reaction conditions of about 50 to 70 DEG C and for about 5 to 30 hours by adding a polymerization initiator under an inert gas stream such as nitrogen.

The polymerization initiator, chain transfer agent and emulsifier used in the radical polymerization are not particularly limited and can be appropriately selected and used. The weight average molecular weight of the (meth) acryl-based polymer (a1) can be controlled depending on the amount of the polymerization initiator, the amount of the chain transfer agent used, and the reaction conditions.

Examples of the polymerization initiator include azo compounds such as 2,2'-azobisisobutyronitrile, 2,2'-azobis (2-amidinopropane) dihydrochloride, 2,2'-azobis [2- Azobis (N, N ', N'-tetramethylpiperidine) dihydrochloride, 2,2'-azobis Azobis [N- (2-carboxyethyl) -2-methylpropionamidine] hydrate (trade name: VA-057, manufactured by Wako Pure Chemical Industries, Ltd.) (2-ethylhexyl) peroxydicarbonate, di (4-t-butylcyclohexyl) peroxydicarbonate, di-sec-butylperoxydi Carbonate, t-butyl peroxyneodecanoate, t-hexyl peroxy pivalate, t-butyl peroxy pivalate, dilauryl peroxide, di-n-octanoyl peroxide, 1,1,3,3 - tetramethylbutylperoxy-2-ethylhexanoate Peroxide such as di (4-methylbenzoyl) peroxide, dibenzoyl peroxide, t-butyl peroxyisobutyrate, 1,1-di (t-hexylperoxy) cyclohexane, A system initiator, a combination of a persulfate and sodium hydrogen sulfite, a redox initiator combined with a peroxide such as a combination of peroxide and sodium ascorbate, and a reducing agent, but the present invention is not limited thereto.

The polymerization initiator may be used alone or in admixture of two or more. The content of the polymerization initiator is preferably about 0.005 to 1 part by weight, more preferably about 0.02 to 1 part by weight based on 100 parts by weight of the total amount of the monomer components. To about 0.5 parts by weight.

Further, in order to produce the (meth) acrylic polymer (a1) having the weight average molecular weight by using, for example, 2,2'-azobisisobutyronitrile as the polymerization initiator, Is preferably about 0.06 to 0.2 part by weight, and more preferably about 0.08 to 0.175 part by weight based on 100 parts by weight of the total amount of the components.

As the chain transfer agent, emulsifier and the like, conventionally known ones can be suitably used. The addition amount thereof can also be appropriately determined within a range that does not impair the effect of the present invention.

The present invention is characterized in that the pressure-sensitive adhesive composition (A1) contains an epoxy group-containing silane coupling agent. By including an epoxy group-containing silane coupling agent in the pressure-sensitive adhesive composition (A1), the durability of the liquid crystal panel as a whole can be improved, and panel warpage and light leakage can be suppressed.

Examples of the epoxy group-containing silane coupling agent include 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 2- (3 , 4-epoxycyclohexyl) ethyltrimethoxysilane, and the like.

In the present invention, as the epoxy group-containing silane coupling agent, it is preferable to use an oligomer-type epoxy group-containing silane coupling agent having at least two alkoxysilyl groups in the molecule. Specific examples thereof include X-41-1053, X-41-1059A and X-41-1056 manufactured by Shin-Etsu Chemical Co., These coupling agents are not volatilized well and have a plurality of alkoxysilyl groups, which is effective for improving durability and is preferable. Here, the oligomer type refers to a polymer of about 2 or more monomeric units and less than 100 monomeric units, and the weight average molecular weight of the oligomeric silane coupling agent is preferably about 300 to 30,000.

The number of the alkoxysilyl groups of the oligomer type epoxy group-containing silane coupling agent may be two or more in the molecule, and the number is not limited. The amount of the alkoxy group of the oligomer type epoxy group-containing silane coupling agent is preferably 10 to 60% by weight, more preferably 15 to 50% by weight, and more preferably 15 to 40% by weight in the silane coupling agent More preferable.

Examples of the alkoxy group include, but are not limited to, alkoxy groups having 1 to 6 carbon atoms such as methoxy, ethoxy, propoxy, butoxy, pentyloxy, and hexyloxy. Among them, methoxy and ethoxy are preferable, and methoxy is more preferable. It is also preferable that both of methoxy and ethoxy are contained in one molecule.

The epoxy equivalent of the epoxy group-containing silane coupling agent is preferably 1000 g / mol or less, more preferably 500 g / mol or less, and still more preferably 300 g / mol or less. The lower limit value of the epoxy equivalent is not particularly limited, but is preferably 200 g / mol or more, for example.

The epoxy group-containing silane coupling agent may be used singly or in admixture of two or more. The content of the epoxy group-containing silane coupling agent is preferably 0.001 to 5 parts by weight per 100 parts by weight of the (meth) acrylic polymer (a1) More preferably 0.01 to 3 parts by weight, still more preferably 0.02 to 2 parts by weight, still more preferably 0.05 to 1 part by weight. By containing an epoxy group-containing silane coupling agent in the above range, durability as a whole of the liquid crystal panel can be improved, and panel warpage and light leakage can be suppressed.

A silane coupling system other than the epoxy group-containing silane coupling agent described above may be added to the pressure-sensitive adhesive composition (A1) used in the present invention. Other coupling agents include 3-aminopropyltrimethoxysilane, N-2- (aminoethyl) -3-aminopropylmethyldimethoxysilane, 3-triethoxysilyl-N- (1,3- Amino group-containing silane coupling agents such as N-phenyl-γ-aminopropyltrimethoxysilane, 3-acryloxypropyltrimethoxysilane, 3-methacryloxypropyltriethoxysilane, etc. ) Acryl group-containing silane coupling agents, and isocyanate group-containing silane coupling agents such as 3-isocyanatepropyltriethoxysilane. The thiol group-containing silane coupling agent to be added to the pressure-sensitive adhesive composition (A2) may be added, but is preferably not included.

The silane coupling agent other than the epoxy group-containing silane coupling agent can be added within the range not hindering the effect of the present invention, and the addition amount thereof is not particularly limited.

The pressure-sensitive adhesive composition (A1) used in the present invention preferably contains a crosslinking agent. As the crosslinking agent, an organic crosslinking agent or a polyfunctional metal chelate can be used. Examples of the organic crosslinking agent include an isocyanate crosslinking agent, a peroxide crosslinking agent, an epoxy crosslinking agent, and an imine crosslinking agent. In the polyfunctional metal chelate, the polyvalent metal is covalently bonded or coordinated with the organic compound. Examples of the multivalent metal atom include Al, Cr, Zr, Co, Cu, Fe, Ni, V, Zn, In, Ca, Mg, Mn, Y, Ce, Sr, Ba, Mo, La, have. Examples of the reactive group in the covalent bond or coordinate bond organic compound include an oxygen atom, and examples of the organic compound include an alkyl ester, an alcohol compound, a carboxylic acid compound, an ether compound, and a ketone compound.

As the crosslinking agent, an isocyanate crosslinking agent and / or a peroxide crosslinking agent are preferable.

As the isocyanate crosslinking agent, a compound having at least two isocyanate groups can be used. For example, known aliphatic polyisocyanates, alicyclic polyisocyanates, aromatic polyisocyanates and the like which are generally used for the urethanization reaction are used.

Examples of the aliphatic polyisocyanate include aliphatic polyisocyanates such as trimethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate, pentamethylene diisocyanate, 1,2-propylene diisocyanate, 1,3-butylene diisocyanate, Isocyanate, 2,4,4-trimethylhexamethylene diisocyanate, and the like.

Examples of the alicyclic isocyanate include 1,3-cyclopentene diisocyanate, 1,3-cyclohexane diisocyanate, 1,4-cyclohexane diisocyanate, isophorone diisocyanate, hydrogenated diphenylmethane diisocyanate, Hydrogenated xylylene diisocyanate, hydrogenated tolylene diisocyanate, hydrogenated tetramethyl xylylene diisocyanate, and the like.

Examples of the aromatic diisocyanate include aromatic diisocyanates such as phenylene diisocyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 2,2'-diphenylmethane diisocyanate, 4,4'- Isocyanate, 4,4'-toluidine diisocyanate, 4,4'-diphenyl ether diisocyanate, 4,4'-diphenyl diisocyanate, 1,5-naphthalene diisocyanate, xylylene diisocyanate and the like.

Examples of the isocyanate crosslinking agent include urethane modified products obtained by reacting the above diisocyanates with polyhydric alcohols such as dimers (dimers, trimesters, pentamers), trimethylolpropane, urea modified products, urea modified products, A modified product thereof, an isocyanurate-modified product, and a carbodiimide-modified product.

Examples of commercial products of isocyanate-based crosslinking agents include trade name "Millionate MT", "Millionate MTL", "Millionate MR-200", "Millionate (trade name)" manufactured by Nippon Polyurethane Industry Co., Takenate D-120N "," Takenate D-120N "," Takenate D-120N "and" Takenate D-120N "manufactured by Mitsui Chemicals, Takenate D-160N "," Takenate D-160N "," Takenate D-165N "," Takenate D-170HN "," Takenate D-178N "," Takenate 500 "," Takenate 600 " . These compounds may be used alone or in combination of two or more.

As the isocyanate crosslinking agent, an aliphatic polyisocyanate and an aliphatic polyisocyanate compound as a modifier thereof are preferable. Compared with other isocyanate-based crosslinking agents, the aliphatic polyisocyanate-based compounds are more flexible in their crosslinking structure and tend to relax stress accompanying expansion / shrinkage of the optical film and do not easily peel off in the durability test. As the aliphatic polyisocyanate compound, hexamethylene diisocyanate and its modified product are particularly preferable.

The peroxide is not particularly limited as long as it generates radical active species by heating or light irradiation to promote crosslinking of the base polymer ((meth) acrylic polymer) of the pressure-sensitive adhesive composition. However, considering the workability and stability, It is preferable to use a peroxide having a temperature of 80 ° C to 160 ° C, and more preferably a peroxide having a temperature of 90 ° C to 140 ° C.

Examples of peroxides that can be used include di (2-ethylhexyl) peroxydicarbonate (1 minute half life temperature: 90.6 占 폚), di (4-t- butylcyclohexyl) peroxydicarbonate Butyl peroxyneodecanoate (1 minute half-life temperature: 103.5 占 폚), t-hexyl peroxy pivalate (1 minute), di-sec-butyl peroxydicarbonate (1 minute half-life temperature: 109.1 占 폚), t-butyl peroxypivalate (1 minute half life temperature: 110.3 占 폚), dilauroyl peroxide (1 minute half life temperature: 116.4 占 폚), di-n-octanoyl peroxide (Half-life temperature: 117.4 占 폚), 1,1,3,3-tetramethylbutylperoxy-2-ethylhexanoate (1 minute half life temperature: 124.3 占 폚), di (4-methylbenzoyl) peroxide Half-life temperature: 128.2 占 폚), dibenzoyl peroxide (one minute half life temperature: 130.0 占 폚), t-butyl peroxyisobutyrate (1 Between the half-life temperature: 136.1 ℃), 1,1- di (t--hexylperoxy) cyclohexane (one minute half life temperature: 149.2 ℃, and the like). Among them, di (4-t-butylcyclohexyl) peroxydicarbonate (1 minute half-life temperature: 92.1 占 폚), dilauroyl peroxide (1 minute half life temperature: 116.4 占 폚) Dibenzoyl peroxide (one-minute half-life temperature: 130.0 占 폚) and the like are preferably used.

 The half-life period of peroxide is an index indicating the rate of decomposition of peroxide, and refers to the time until the amount of residual peroxide becomes half. The decomposition temperature for obtaining a half-life at an arbitrary time and the half-life time at an arbitrary temperature are described in the manufacturer's catalog, and are described in, for example, Nippon Oil & May) ".

The amount of the crosslinking agent to be used is preferably 0.01 to 2 parts by weight, more preferably 0.02 to 1 part by weight, and still more preferably 0.03 to 0.5 part by weight based on 100 parts by weight of the (meth) acrylic polymer (a1). If the amount of the crosslinking agent is less than 0.01 part by weight, the pressure-sensitive adhesive layer may become insufficiently cross-linked to fail to satisfy durability and adhesion characteristics. On the other hand, if the amount is more than 2 parts by weight, the pressure-sensitive adhesive layer becomes too hard and durability tends to deteriorate see.

The isocyanate-based crosslinking agent may be used singly or in admixture of two or more. The content of the isocyanate-based crosslinking agent is preferably 0.01 to 2 parts by weight (based on 100 parts by weight of the (meth) acrylic polymer , More preferably 0.02 to 1 part by weight, and still more preferably 0.03 to 0.5 part by weight. Cohesive force, prevention of peeling in the durability test, and the like.

The peroxide may be used singly or in admixture of two or more. The content of the peroxide is preferably 0.01 to 2 parts by weight based on 100 parts by weight of the (meth) acryl-based polymer (a1) By weight, more preferably 0.04 to 1.5 parts by weight, still more preferably 0.05 to 1 part by weight. Is appropriately selected within this range for the purpose of adjusting workability, reworkability, crosslinking stability, releasability and the like.

The pressure-sensitive adhesive composition (A1) used in the present invention may further contain an ionic compound. As the ionic compound, any one ordinarily usable in the art can be suitably used. The amount of the ionic compound to be added can be appropriately determined within a range not hindering the effect of the present invention.

The pressure-sensitive adhesive composition (A1) used in the present invention may contain a polyether compound having a reactive silyl group. The polyether compound is preferable in that it can improve the workability. As the polyether compound, for example, those disclosed in JP-A-2010-275522 can be used.

The pressure-sensitive adhesive composition (A1) used in the present invention may contain other known additives, for example, a polyether compound of a polyalkylene glycol such as polypropylene glycol, a powder such as a colorant or a pigment, A surfactant, a plasticizer, a tackifier, a surface lubricant, a leveling agent, a softener, an antioxidant, an antioxidant, a light stabilizer, an ultraviolet absorber, a polymerization inhibitor, an inorganic or organic filler, a metal powder, ) Can be suitably added depending on the use of the composition. Also, a redox system to which a reducing agent is added may be employed within a controllable range. These additives are preferably used in an amount of not more than 5 parts by weight, more favorably not more than 3 parts by weight, and further not more than 1 part by weight, based on 100 parts by weight of the (meth) acrylic polymer (a1).

(2) Pressure-sensitive adhesive composition (A2)

The pressure-sensitive adhesive composition (A2) used in the present invention comprises a (meth) acryl-based polymer (a2) and a thiol group-containing silane coupling agent, and preferably contains a (meth) acrylic polymer (a2) as a main component. Here, the main component is as described above.

In the present invention, the pressure-sensitive adhesive composition (A2) is characterized by containing a thiol group-containing silane coupling agent. By including a thiol group-containing silane coupling agent in the pressure-sensitive adhesive composition (A2), durability as a whole liquid crystal panel can be improved, and panel warpage and light leakage can be suppressed.

Examples of the thiol group-containing silane coupling agent include 3-mercaptopropyltrimethoxysilane, 3-mercaptopropylmethyldimethoxysilane, 3-mercaptopropyltriethoxysilane, 3-mercaptopropylmethyldiethoxysilane, mercaptomethyltrimethoxysilane, 6-mercaptohexyltrimethoxysilane, 10-mercaptodecyltrimethoxysilane and the like, and the like can be given. have.

As the thiol group-containing silane coupling agent, an oligomer-type thiol group-containing silane coupling agent having at least two alkoxysilyl groups in the molecule is preferred. Specific examples thereof include X-41-1805, X-41-1818 and X-41-1810 manufactured by Shin-Etsu Chemical Co., These thiol group-containing silane coupling agents are preferable because they are not volatilized well and have a plurality of alkoxysilyl groups, which is effective for improving durability. Here, the oligomer type refers to a polymer of about 2 or more monomeric units and less than 100 monomeric units, and the weight average molecular weight of the oligomeric silane coupling agent is preferably about 300 to 30,000.

The number of the alkoxysilyl groups of the oligomer type thiol group-containing silane coupling agent may be two or more in the molecule, and the number is not limited. The amount of the alkoxy group of the oligomer type thiol group-containing silane coupling agent is preferably 10 to 60% by weight, more preferably 20 to 50% by weight, and more preferably 20 to 40% by weight in the silane coupling agent desirable.

Examples of the alkoxy group include, but are not limited to, alkoxy groups having 1 to 6 carbon atoms such as methoxy, ethoxy, propoxy, butoxy, pentyloxy, and hexyloxy. Among them, methoxy and ethoxy are preferable, and methoxy is more preferable. It is also preferable that both of methoxy and ethoxy are contained in one molecule.

The content of the thiol group in the thiol group-containing silane coupling agent is preferably 1,000 g / mol or less, more preferably 800 g / mol or less, more preferably 500 g / mol or less, in the case of a mercapto group, Or less. The lower limit of the mercapto equivalent is not particularly limited, but is preferably 200 g / mol or more, for example.

The thiol group-containing silane coupling agent may be used singly or in admixture of two or more. The content of the thiol group-containing silane coupling agent is preferably 0.001 to 5 parts by weight (based on 100 parts by weight of the (meth) acrylic polymer More preferably 0.01 to 3 parts by weight, still more preferably 0.02 to 2 parts by weight, still more preferably 0.05 to 1 part by weight. By containing the thiol group-containing silane coupling agent within the above range, durability as a whole of the liquid crystal panel can be improved, and panel warpage and light leakage can be suppressed.

A silane coupling system other than the thiol group-containing silane coupling agent may be added to the pressure-sensitive adhesive composition (A2) used in the present invention. Other coupling agents include 3-aminopropyltrimethoxysilane, N-2- (aminoethyl) -3-aminopropylmethyldimethoxysilane, 3-triethoxysilyl-N- (1,3- Amino group-containing silane coupling agents such as N-phenyl-γ-aminopropyltrimethoxysilane, 3-acryloxypropyltrimethoxysilane, 3-methacryloxypropyltriethoxysilane, etc. ) Acryl group-containing silane coupling agents, and isocyanate group-containing silane coupling agents such as 3-isocyanatepropyltriethoxysilane.

The silane coupling agent other than the thiol group-containing silane coupling agent may be added within the range not hindering the effect of the present invention, and the addition amount thereof is not particularly limited.

As the (meth) acrylic polymer (a2), a (meth) acryl-based polymer having any of the compositions exemplified for the (meth) acrylic polymer (a1) used in the pressure-sensitive adhesive composition (A1) may be suitably used. As with the pressure-sensitive adhesive composition (A1), a crosslinking agent, a polyether compound and other additives can be added to the pressure-sensitive adhesive composition (A2), and the composition and amount thereof are the same as those of the pressure-sensitive adhesive composition (A1). However, in the pressure-sensitive adhesive composition (A1) and the pressure-sensitive adhesive composition (A2), the composition and amount of the (meth) acryl-based polymer may be the same or different, and the kinds and amounts of the crosslinking agent, polyether compound, And may be different.

(3) Pressure-sensitive adhesive layer

First and second pressure-sensitive adhesive layers are formed from the pressure-sensitive adhesive compositions (A1) and (A2).

The gel fraction of the first pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition (A1) is preferably 65 to 90% and preferably 70 to 85%. In order to suppress light leakage in a display device requiring a narrow frame, shrinkage of the polarizing film must be suppressed, and it is preferable that the pressure-sensitive adhesive layer is hard. On the other hand, however, if the pressure-sensitive adhesive layer is too hard, it is not preferable from the viewpoint of durability when the pressure-sensitive adhesive layer is applied to the display cell. In the present invention, it is preferable that the gel fraction of the first pressure-sensitive adhesive layer is 65% or more so that light leakage can be suppressed and the gel fraction is 90% or less, thereby providing excellent durability to the transparent conductive layer.

The gel fraction of the second pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition (A2) is preferably 65 to 90% and preferably 70 to 85% for the same reason as the first pressure-sensitive adhesive layer. When the gel fraction of the second pressure sensitive adhesive layer is 65% or more, light leakage can be suppressed. The gel fraction of 90% or less is preferable because it has excellent durability against glass.

 In the present invention, it is preferable that the gel fraction of the first pressure-sensitive adhesive layer and the second pressure-sensitive adhesive layer satisfy the following formula (1):

. The hardness of the first pressure-sensitive adhesive layer formed on the transparent conductive layer on one side of the liquid crystal cell and the second pressure-sensitive adhesive layer formed on the other side of the liquid crystal cell are close to each other, By satisfying the range, warping of the panel can be suppressed. The above range is preferably 0.1 or less, more preferably 0.05 or less.

In forming the first and second pressure-sensitive adhesive layers, it is preferable to consider the influence of the crosslinking treatment temperature and the crosslinking treatment time in addition to adjusting the addition amount of the whole crosslinking agent.

Depending on the crosslinking agent used, the crosslinking temperature and the crosslinking time can be adjusted. The crosslinking treatment temperature is preferably 170 占 폚 or less. The crosslinking treatment may be carried out at a temperature in the drying step of the pressure-sensitive adhesive layer, or may be carried out by providing a separate crosslinking step after the drying step.

The crosslinking treatment time can be set in consideration of productivity and workability, but is usually about 0.2 to 20 minutes, preferably about 0.5 to 10 minutes.

The method of forming the pressure-sensitive adhesive layer is not particularly limited, but the pressure-sensitive adhesive composition may be coated on various substrates, and dried by a dryer such as a heat oven to volatilize the solvent or the like, Or a method of transferring the pressure-sensitive adhesive layer onto a substrate of a polarizing film or liquid crystal cell to be described later. Alternatively, the pressure-sensitive adhesive composition may be directly applied on the polarizing film or the liquid-crystal cell to form a pressure-sensitive adhesive layer. In the present invention, a method is preferable in which a polarizing film having a pressure-sensitive adhesive layer formed on a polarizing film is preliminarily prepared, and a polarizing film having the pressure-sensitive adhesive layer is attached to the liquid-crystal cell.

The substrate is not particularly limited, and examples thereof include various substrates such as a release film and a transparent resin film substrate.

As a method of applying the pressure-sensitive adhesive composition to the substrate or the polarizing film, various methods are used. Specifically, there may be mentioned, for example, fountain coaters, roll coats, kiss roll coats, gravure coats, reverse coats, roll brushes, spray coats, dip roll coats, bar coats, knife coats, air knife coats, curtain coats, An extrusion coating method using a die coater or the like.

The drying conditions (temperature and time) are not particularly limited, but may be appropriately set according to the composition, concentration, etc. of the pressure-sensitive adhesive composition. For example, the drying conditions (temperature and time) may range from 80 to 170 캜, preferably 90 to 200 캜, Minute, preferably 2 to 30 minutes.

 After drying, crosslinking treatment may be carried out if necessary, and the conditions are as described above.

The thickness of the pressure-sensitive adhesive layer (after drying) is preferably, for example, 5 to 100 占 퐉, more preferably 7 to 70 占 퐉, and further preferably 10 to 50 占 퐉. If the thickness of the pressure-sensitive adhesive layer is less than 5 占 퐉, the adhesion to the adherend becomes insufficient, and the durability under high temperature, high temperature and high humidity tends to be insufficient. On the other hand, when the thickness of the pressure-sensitive adhesive layer is more than 100 占 퐉, it is impossible to sufficiently dry the pressure-sensitive adhesive composition when the pressure-sensitive adhesive composition is formed and dried at the time of forming the pressure-sensitive adhesive layer, So that the apparent problem tends to become easier to visualize.

Examples of the constituent material of the release film include a resin film such as polyethylene, polypropylene, polyethylene terephthalate and polyester film, a porous material such as paper, cloth and nonwoven fabric, a net, a foamed sheet, a metal foil, A suitable lamellar retarder such as a laminate, and the like, but a resin film is preferably used because of its excellent surface smoothness.

Examples of the resin film include a polyethylene film, a polypropylene film, a polybutene film, a polybutadiene film, a polymethylpentene film, a polyvinyl chloride film, a vinyl chloride copolymer film, a polyethylene terephthalate film, a polybutylene terephthalate Film, a polyurethane film, an ethylene-vinyl acetate copolymer film, and the like.

The thickness of the release film is usually 5 to 200 占 퐉, and preferably 5 to 100 占 퐉. The releasing film may be subjected to antistatic treatment such as releasing treatment with a releasing agent of silicon type, fluorine type, long chain alkyl type or fatty acid amide type, silica powder or the like, coating type, kneading type, have. Particularly, the releasability from the pressure-sensitive adhesive layer can be further improved by suitably carrying out the surface treatment of the release film, such as silicone treatment, long-chain alkyl treatment or fluorine treatment.

The transparent resin film base material is not particularly limited, but various resin films having transparency are used. The resin film is formed of a single-layer film. For example, as the material thereof, a polyester resin such as polyethylene terephthalate and polyethylene naphthalate, an acetate resin, a polyether sulfone resin, a polycarbonate resin, a polyamide resin, a polyimide resin, a polyolefin resin , A (meth) acrylic resin, a polyvinyl chloride resin, a polyvinylidene chloride resin, a polystyrene resin, a polyvinyl alcohol resin, a polyarylate resin, and a polyphenylene sulfide resin. Of these, particularly preferred are polyester resins, polyimide resins and polyether sulfone resins.

The thickness of the film substrate is preferably 15 to 200 탆.

Further, an anchor layer may be provided between the polarizing film and the pressure-sensitive adhesive layer. The material for forming the anchor layer is not particularly limited, and examples thereof include various polymers, sols of metal oxides, silica sol, and the like. Of these, polymers are particularly preferably used. The polymer may be used in any of solvent-soluble type, water-dispersible type and water-soluble type.

Examples of the polymers include polyurethane resins, polyester resins, acrylic resins, polyether resins, cellulose resins, polyvinyl alcohol resins, polyvinyl pyrrolidone, and polystyrene resins have. Among these, a polyurethane resin, a polyester resin and an acrylic resin are particularly preferable. A crosslinking agent may be appropriately added to these resins. These other binder components may be used singly or in combination of two or more thereof in accordance with their use. The thickness of the anchor layer is not particularly limited, but is preferably 5 to 300 nm.

The method for forming the anchor layer is not particularly limited, and can be generally carried out by a known method. In forming the anchor layer, the iodine-based polarizing film may be subjected to an activation treatment. Various methods may be employed for the activation treatment, and for example, corona treatment, low-pressure UV treatment, plasma treatment, or the like may be employed.

The method of forming the pressure-sensitive adhesive layer on the anchor layer on the polarizing film is as described above.

When the pressure-sensitive adhesive layer of the polarizing film having the pressure-sensitive adhesive layer and the pressure-sensitive adhesive layer on the liquid-crystal cell are exposed, the pressure-sensitive adhesive layer may be protected with a release film (separator) until it is provided for practical use. Examples of the release film include those described above. When a release film is used as the base material in the production of the pressure-sensitive adhesive layer, the pressure-sensitive adhesive layer on the release film and the polarizing film or the liquid crystal cell are bonded to each other to form a releasable film having a polarizing film with a pressure- It can be used as a release film of the pressure-sensitive adhesive layer of the liquid crystal cell, and the process can be simplified.

The first polarizing film and the second polarizing film are not particularly limited, but a polarizing film having a transparent protective film on one side or both sides thereof is generally used.

The polarizer is not particularly limited, and various kinds of polarizers can be used. Examples of the polarizer include a hydrophilic polymer film such as a polyvinyl alcohol film, a partially porous polyvinyl alcohol film, and a partially saponified ethylene / vinyl acetate copolymer film, And polyene-based oriented films such as polyvinyl alcohol dehydrated products and polyvinyl chloride dehydrochloric acid treated products. Among them, a polyvinyl alcohol film and a polarizer made of a dichroic substance such as iodine are preferable, and an iodine polarizer containing iodine and / or iodine ion is more preferable. The thickness of these polarizers is not particularly limited, but is generally about 5 to 80 탆.

A polarizer obtained by dying a polyvinyl alcohol film with iodine and uniaxially stretching can be produced by, for example, dying polyvinyl alcohol in an aqueous solution of iodine and stretching it to 3 to 7 times the original length. If necessary, it may be immersed in an aqueous solution of potassium iodide or the like which may contain boric acid, zinc sulfate, zinc chloride or the like. If necessary, the polyvinyl alcohol film may be dipped in water and washed with water before dyeing. The polyvinyl alcohol film is washed with water to clean the surface of the polyvinyl alcohol film and to prevent unevenness such as uneven dyeing by swelling the polyvinyl alcohol film. The stretching may be carried out after dyeing with iodine, followed by stretching while dyeing, or after stretching, followed by dyeing with iodine. It can be stretched in an aqueous solution such as boric acid or potassium iodide or in a water bath.

As a material for forming the transparent protective film formed on one side or both sides of the polarizer, for example, a thermoplastic resin excellent in transparency, mechanical strength, thermal stability, moisture barrier property, isotropy and the like is used. Specific examples of such a thermoplastic resin include cellulose resin such as triacetyl cellulose, polyester resin, polyethersulfone resin, polysulfone resin, polycarbonate resin, polyamide resin, polyimide resin, polyolefin resin, (meth) acryl Resin, cyclic polyolefin resin (norbornene resin), polyarylate resin, polystyrene resin, polyvinyl alcohol resin, and mixtures thereof. The transparent protective film is adhered to the one side of the polarizer by an adhesive layer while the other side of the polarizing film is provided with a thermosetting resin such as a (meth) acrylic, urethane, acrylic urethane, epoxy or silicone resin or a UV- Can be used. The transparent protective film may contain one or more optional additives. Examples of the additive include an ultraviolet absorber, an antioxidant, a lubricant, a plasticizer, a release agent, a coloring inhibitor, a flame retardant, a nucleating agent, an antistatic agent, a pigment and a colorant. The content of the thermoplastic resin in the transparent protective film is preferably 50 to 100% by weight, more preferably 50 to 99% by weight, still more preferably 60 to 98% by weight, particularly preferably 70 to 97% by weight . When the content of the thermoplastic resin in the transparent protective film is 50% by weight or less, there is a possibility that the high transparency and the like inherently possessed by the thermoplastic resin can not be sufficiently exhibited.

The thickness of the protective film can be suitably determined, but generally it is about 1 to 500 占 퐉 in view of workability such as strength and handling properties and thin film properties.

The polarizer and the protective film are normally in close contact with each other through an aqueous adhesive or the like. Examples of the water-based adhesive include an isocyanate-based adhesive, a polyvinyl alcohol-based adhesive, a gelatin-based adhesive, a vinyl-based latex-based, a water-based polyurethane, and a water-based polyester. In addition to the above, examples of the adhesive for the polarizer and the transparent protective film include an ultraviolet curable adhesive, an electron beam curable adhesive, and the like. The adhesive for an electron beam hardening type polarizing film exhibits suitable adhesiveness to the above various transparent protective films. The adhesive used in the present invention may contain a metal compound filler.

In the present invention, a retardation film or the like may be formed on the polarizer instead of the transparent protective film of the polarizing film. Further, another transparent protective film may be formed on the transparent protective film, or a retardation film or the like may be formed.

The surface of the transparent protective film which is not adhered to the opposite side (visual side) to the liquid crystal cell may be subjected to a treatment for the purpose of hard coat layer, antireflection treatment, anti-sticking, diffusion or anti-glare treatment.

(4) Configuration of liquid crystal panel

The liquid crystal panel of the present invention is characterized in that a transparent conductive layer is formed on one surface of a liquid crystal cell and a first polarizing film is bonded onto the transparent conductive layer via a pressure-sensitive adhesive layer formed from the pressure- , A second polarizing film is bonded to the other surface of the liquid crystal cell via a pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition (A2)

The pressure-sensitive adhesive composition (A1) comprises a (meth) acrylic polymer (a1) and an epoxy group-containing silane coupling agent,

Wherein the pressure-sensitive adhesive composition (B2) comprises a silane coupling agent containing a (meth) acrylic polymer (a2) and a thiol group, and further controlling the gel fraction of the first pressure-sensitive adhesive layer and the second pressure- Other configurations are not particularly limited. A specific configuration of the liquid crystal panel of the present invention will be described with reference to Fig. 1, but the present invention is not limited thereto.

An aspect of the liquid crystal panel 11 of the present invention shown in Fig. 1 is as follows.

The liquid crystal cell 10 includes a liquid crystal layer 8, a first transparent substrate 7 (visible side) disposed on one side of the liquid crystal layer 8, And a second transparent substrate 9 (light source side), and a transparent conductive layer 6 is formed on the first transparent substrate 7. On the transparent conductive layer side of the liquid crystal cell, a first polarizing film 4a is laminated via a first pressure-sensitive adhesive layer 5a formed from a pressure-sensitive adhesive composition A1. The first polarizing film 4a has a polarizer 2a between the visible side transparent protective film 1a and the liquid crystal cell side transparent protective film 3a. On the opposite side of the transparent conductive layer of the liquid crystal cell, the second polarizing film 4b is laminated via the second pressure-sensitive adhesive layer 5b formed from the pressure-sensitive adhesive composition A2. The second polarizing film 4b has a polarizer 2b between the light source side transparent protective film 3b and the liquid crystal cell side transparent protective film 1b.

In the liquid crystal panel 11 of Fig. 1, both the first polarizing film 4a and the second polarizing film 4b use a double-side protective polarizing film having a transparent protective film on both surfaces of the polarizer, A single-side protective polarizing film having a transparent protective film on only one side of the polarizer may be used. It is also possible to use a retardation layer in place of the liquid crystal cell side transparent protective films 3a and 1b of the polarizing films 4a and 4b or to use a retarder layer on the liquid crystal cell side transparent protective films 3a and 1b A retardation layer may be formed.

In addition to the above configuration, optical films such as a retardation film, a time compensating film, and a luminance improving film can be appropriately formed on the liquid crystal panel 11. [

The liquid crystal layer 8 is not particularly limited and may be any type such as TN type, STN type, π type, VA type, and IPS type. The first transparent substrate 7 (visible side) constituting the liquid crystal cell 10 and the second transparent substrate 9 (light source side) disposed on the other side of the liquid crystal layer are both transparent substrates And the material thereof is not particularly limited, and examples thereof include glass and transparent resin film substrates. Examples of the transparent resin film substrate include those described above.

The first and second pressure-sensitive adhesive layers formed from the first polarizing film 4a, the second polarizing film 4b and the pressure-sensitive adhesive composition A1 or A2 are as described above.

The constituent material of the transparent conductive layer 6 is not particularly limited and may be selected from the group consisting of indium, tin, zinc, gallium, antimony, titanium, silicon, zirconium, magnesium, aluminum, gold, silver, copper, palladium and tungsten At least one kind of metal oxide selected from metals is used. The metal oxide may further contain a metal atom shown in the above group, if necessary. For example, indium oxide (ITO) containing tin oxide, tin oxide containing antimony and the like are preferably used, and ITO is particularly preferably used. ITO preferably contains 80 to 99% by weight of indium oxide and 1 to 20% by weight of tin oxide.

As the ITO, crystalline ITO and amorphous (ITO) can be used, and any of them can be suitably used.

The thickness of the transparent conductive layer 6 is not particularly limited, but is preferably 10 nm or more, more preferably 15 to 40 nm, and further preferably 20 to 30 nm.

The method for forming the transparent conductive layer 6 is not particularly limited, and conventionally known methods can be employed. Specifically, for example, a vacuum deposition method, a sputtering method, and an ion plating method can be exemplified. An appropriate method may be employed depending on the required film thickness.

An undercoat layer, an oligomer-preventing layer, or the like can be formed between the transparent conductive layer 6 and the first transparent substrate 7, if necessary.

In the liquid crystal panel of the present invention, the first polarizing film is disposed on the transparent conductive layer on one surface of the liquid crystal cell via a first adhesive layer formed from a specific adhesive composition, and the other polarizing film It is possible to improve the durability of the liquid crystal panel as a whole by disposing the second polarizing film through the second pressure sensitive adhesive layer formed from a specific pressure sensitive adhesive composition on the surface will be.

2. Image display device

The image display apparatus of the present invention includes the liquid crystal panel of the present invention. Hereinafter, a liquid crystal display device will be described as an example, but the present invention can be applied to all display devices requiring a liquid crystal panel.

Specific examples of the image display apparatus to which the liquid crystal panel of the present invention can be applied include a liquid crystal display, an electroluminescence (EL) display, a plasma display (PD), a field emission display (FED) have.

The image display device of the present invention may be any device that includes the liquid crystal panel of the present invention, and the other configurations are the same as those of the conventional image display device.

Example

Hereinafter, the present invention will be described in detail by way of examples, but the present invention is not limited to these examples. In addition, the room temperature and no-specified conditions, which are not specially specified, are all 23 ° C, 65% RH. to be.

<Measurement of weight average molecular weight of (meth) acryl-based polymer>

The weight average molecular weight (Mw) of the (meth) acryl-based polymer was measured by GPC (gel permeation chromatography). Mw / Mn was measured in the same manner.

· Analytical Apparatus: HLC-8120GPC manufactured by Tosoh Corporation

· Column: G7000H _XL + GMH _XL + GMH _XL , manufactured by Tosoh Corporation

· Column size: Each 7.8 mmφ × 30 cm Total 90 cm

Column temperature: 40 ° C

Flow rate: 0.8 ml / min

· Injection volume: 100 μl

Eluent: tetrahydrofuran

Detector: Differential refractometer (RI)

· Standard sample: Polystyrene

Production Example 1 (Production of polarizing film)

A polyvinyl alcohol film having a thickness of 80 占 퐉 was stretched to 3 times while dyeing in an iodine solution at a concentration of 0.3 wt% at 30 占 폚 for 1 minute between rolls having different velocity ratios. Thereafter, the substrate was immersed in an aqueous solution containing boric acid at a concentration of 4 wt% at a concentration of 4 wt% and potassium iodide at a concentration of 10 wt% for 0.5 min to stretch the coating film to a total draw ratio of 6 times. Subsequently, the substrate was washed by immersing it in an aqueous solution containing potassium iodide at a concentration of 1.5% by weight at 30 DEG C for 10 seconds, and then dried at 50 DEG C for 4 minutes to obtain a polarizer having a thickness of 30 mu m. A saponified triacetylcellulose film having a thickness of 80 mu m was laminated on both sides of the polarizer using a polyvinyl alcohol adhesive to prepare a polarizing film.

Preparation Example 2 (Preparation of solution of acrylic polymer (a-1)) [

A monomer mixture containing 99 parts by weight of butyl acrylate and 1 part by weight of 4-hydroxybutyl acrylate was added to a four-necked flask equipped with a stirrer, a thermometer, a nitrogen gas introducing tube and a condenser. Further, 0.1 part by weight of 2,2'-azobisisobutyronitrile as a polymerization initiator was added to 100 parts by weight of the monomer mixture (solid content) together with 100 parts by weight of ethyl acetate, and nitrogen gas was introduced while gently stirring After the purging with nitrogen, the solution temperature in the flask was maintained at about 55 ° C to carry out polymerization reaction for 8 hours to prepare a solution of the acrylic polymer (a-1) having a weight average molecular weight (Mw) of 156,000 and a Mw / Mn of 3.2.

Production Examples 3 and 4

(A-2), (a-2), and (a-2) were obtained in the same manner as in Production Example 2, except that the kinds of the monomers used in the preparation of the acrylic polymer, -3) was prepared.

The abbreviations in Table 1 are as follows.

BA: butyl acrylate

NVP: N-vinyl-2-pyrrolidone

AA: Acrylic acid

HBA: 4-hydroxybutyl acrylate

Example 1

(Adjustment of acrylic pressure-sensitive adhesive composition (A1)) [

0.1 part of an isocyanate crosslinking agent (trade name: Takenate D160N, trimethylolpropane hexamethylene diisocyanate, manufactured by Mitsui Chemicals, Inc.) relative to 100 parts by weight of the solid content of the solution of the acrylic polymer (a-1) obtained in Production Example 2, , 0.3 part of peroxide (Nippon BMT 40SV, manufactured by NOF Corporation) and 0.3 part of? -Glycidoxypropylmethoxysilane (trade name: KBM-403, Shin-Etsu Chemical Co., Ltd.) A solution of the composition (A1) was prepared.

(Adjustment of acrylic pressure-sensitive adhesive composition (A2)) [

0.1 part of an isocyanate crosslinking agent (trade name: Takenate D160N, trimethylolpropane hexamethylene diisocyanate, manufactured by Mitsui Chemicals, Inc.) relative to 100 parts by weight of the solid content of the solution of the acrylic polymer (a1) obtained in Production Example 2, (KBM-803, Shin-Etsu Chemical Co., Ltd.) 0.3 part were mixed with 0.3 part of an acrylic pressure-sensitive adhesive composition (Nippon BMT 40SV, A2) was prepared.

(Production of a polarizing film having a pressure-sensitive adhesive layer)

A solution of the acrylic pressure-sensitive adhesive composition (A1) was applied to one surface of a polyethylene terephthalate film (separator film, trade name: MRF38, manufactured by Mitsubishi Chemical Polyester Film Co., Ltd.) treated with a silicone- , And dried at 155 캜 for 1 minute to form a pressure-sensitive adhesive layer on the surface of the separator film. Subsequently, the pressure-sensitive adhesive layer formed on the separator film was transferred to the polarizing film prepared in Production Example 1 to prepare a polarizing film (A1) with a pressure-sensitive adhesive layer. Using the solution of the acrylic pressure-sensitive adhesive composition (A2), a polarizing film (A2) with a pressure-sensitive adhesive layer was produced in the same manner.

Examples 2 to 12 and Comparative Examples 1 to 10

The acrylic pressure-sensitive adhesive composition (1) was obtained in the same manner as in Example 1, except that the kinds of the acrylic polymers (a1) and (a2), the kind of the silane coupling agent, (A1) and (A2) were prepared. Using the obtained solution of the acrylic pressure-sensitive adhesive composition, a polarizing film with a pressure-sensitive adhesive layer was prepared in the same manner as in Example 1. [

The abbreviations in Table 2 are as follows.

Isocyanate system: trade name: Takenate D160N, trimethylolpropane hexamethylene diisocyanate, manufactured by Mitsui Chemicals, Inc.

Peroxide system: Product name: Naipa BMT 40SV, benzoyl peroxide, manufactured by Nippon Oil Corporation

KBM403:? -Glycidoxypropylmethoxysilane, trade name: KBM-403, manufactured by Shin-Etsu Chemical Co., Ltd.

KBM803: 3-mercaptopropyltrimethoxysilane, trade name: KBM-803, manufactured by Shin-Etsu Chemical Co., Ltd.

X-41-1056: Oligomer-type epoxy group-containing silane coupling agent, amount of alkoxy group: 17% by weight, epoxy equivalent: 280 g / mol, manufactured by Shin-Etsu Chemical Co.,

X-41-1810: oligomer type mercapto group-containing silane coupling agent, alkoxy group content: 30% by weight, mercapto equivalent: 450 g / mol, manufactured by Shin-Etsu Chemical Co.,

KBM-5103: 3-acryloxypropyltrimethoxysilane, manufactured by Shin-Etsu Chemical Co., Ltd.

KBE-9007: 3-isocyanate propyltriethoxysilane manufactured by Shin-Etsu Chemical Co., Ltd.

The polarizing films with the pressure-sensitive adhesive layers obtained in the above Examples and Comparative Examples were subjected to the following evaluations. The evaluation results are shown in Table 3.

&Lt; Production of liquid crystal panel &

The polarizing films (A1) and (A2) with the pressure-sensitive adhesive layer obtained in Examples and Comparative Examples were cut into a size of 109 mm 59 mm. The absorption axis of the polarizing plate was cut so that the absorption axis of the polarizing plate was parallel to the short side in the polarizing film (A1) with the pressure-sensitive adhesive layer attached and parallel to the long side in the polarizing film (A2) with the pressure-sensitive adhesive layer. A polarizing film (A1) having a pressure-sensitive adhesive layer adhered to the ITO surface of a liquid crystal panel of 110 mm x 60 mm and a thickness of 0.32 mm and a polarizing film (A2) having a pressure-sensitive adhesive layer adhered to the glass surface were adhered using a laminator. Subsequently, the autoclave treatment was carried out at 50 캜 and 0.5 MPa for 15 minutes, and the polarizing film was brought into close contact with the liquid crystal panel to obtain a liquid crystal panel for evaluation. The polarizing films (A1) and (A2) with the pressure-sensitive adhesive layer attached to the ITO surface and the glass surface of the liquid crystal panel are the same as those of the polarizing films (A1) and (A2).

<Panel bending>

The manufactured evaluation liquid crystal panel was exposed for 24 hours in an atmosphere at 80 캜. The exposed liquid crystal panel was left for one hour at room temperature and placed on a flat stand so that the four corners floated according to the direction of the warp and was measured with a laser displacement gauge (trade name: LK-G35, The height of the four corners was measured. The value obtained by averaging the measured values of each of the four corners was taken as a bending amount, and the evaluation criteria were as follows.

?: Less than 0.2 mm of warpage

DELTA: warpage of 0.2 mm or more and less than 0.5 mm

X: Deflection of at least 0.5 mm

<Durability Test>

The resulting evaluation liquid crystal panel was placed in an atmosphere at 85 占 폚 for 500 hours (heating test), and after heating at 60 占 폚, 95% RH. (Humidifying test), and the foaming and peeling of the pressure-sensitive adhesive layer were observed with naked eyes and evaluated according to the following evaluation criteria.

(Evaluation standard)

?: No apparent change such as foaming or peeling was observed.

?: There is peeling or foaming at a slight end, but no problem in practical use.

[Delta]: There is peeling or foaming at the end, but there is no practical problem unless it is a special use.

X: There is a remarkable peeling at the end portion, and there is a practical problem.

<Light leakage>

The liquid crystal panel after the durability test at 85 占 폚 was placed in the dark room under the light transmitted from the backlight and the presence or absence of light leakage from the end of the polarizing plate was observed and evaluated according to the following evaluation criteria.

○: No light leakage.

X: There was light leakage.

1a: Visible side transparent protective film
1b: transparent protective film on the liquid crystal cell side
2a: Polarizer
2b: Polarizer
3a: transparent protective film on the liquid crystal cell side
3b: transparent protective film on the light source side
4a: first polarizing film
4b: second polarizing film
5a: a first pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition (A1)
5b: a second pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition (A2)
6: transparent conductive layer
7: first transparent substrate
8: liquid crystal layer
9: second transparent substrate
10: liquid crystal cell
11: liquid crystal panel

Claims (10)

A transparent conductive layer is formed on one surface of the liquid crystal cell and a first polarizing film is bonded to the transparent conductive layer via a first pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition A1, And a second polarizing film is bonded via a second pressure-sensitive adhesive layer formed from the pressure-sensitive adhesive composition (A2) to the other surface of the liquid-
The pressure-sensitive adhesive composition (A1) comprises a (meth) acrylic polymer (a1) and an epoxy group-containing silane coupling agent,
The pressure-sensitive adhesive composition (A2) comprises a (meth) acrylic polymer (a2) and a thiol group-containing silane coupling agent,
Wherein the gel fraction of the first pressure-sensitive adhesive layer and the second pressure-sensitive adhesive layer is 65% or more and 90% or less, and further satisfies the following formula (1).
[Equation 1]

The method according to claim 1,
Wherein the epoxy group-containing silane coupling agent is an oligomer-type epoxy group-containing silane coupling agent having at least two alkoxysilyl groups in the molecule. 3. The method according to claim 1 or 2,
Wherein the thiol group-containing silane coupling agent is an oligomer-type thiol group-containing silane coupling agent having at least two alkoxysilyl groups in the molecule. 4. The method according to any one of claims 1 to 3,
Wherein the blending amount of the epoxy group-containing silane coupling agent is 0.001 to 5 parts by weight based on 100 parts by weight of the (meth) acrylic polymer (a1). 5. The method according to any one of claims 1 to 4,
Wherein the blending amount of the thiol group-containing silane coupling agent is 0.001 to 5 parts by weight based on 100 parts by weight of the (meth) acrylic polymer (a2). 6. The method according to any one of claims 1 to 5,
Wherein the (meth) acrylic polymer (a1) and / or (a2) comprises 0.01 to 2% by weight of a monomer containing a carboxyl group as a monomer unit. 7. The method according to any one of claims 1 to 6,
Wherein the (meth) acrylic polymer (a1) and / or (a2) comprises 0.1 to 8% by weight of an amide group-containing monomer as a monomer unit. 8. The method according to any one of claims 1 to 7,
Wherein the (meth) acryl-based polymer (a1) and / or (a2) comprises 0.01 to 7% by weight of a hydroxyl group-containing monomer as a monomer unit. 9. The method according to any one of claims 1 to 8,
Wherein the pressure-sensitive adhesive composition (A1) and / or the pressure-sensitive adhesive composition (A2) contains at least one crosslinking agent selected from the group consisting of an isocyanate crosslinking agent and a peroxide crosslinking agent. An image display apparatus characterized by using the liquid crystal panel according to any one of claims 1 to 9.

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