KR102533838B1 - Liquid crystal panels and liquid crystal displays - Google Patents

Abstract

The present invention provides an IPS mode liquid crystal cell (C), a first optical functional layer (A1) and a first polarizing film (P1) sequentially disposed from the viewing side of the liquid crystal cell (C), and the liquid crystal cell (C ) In the liquid crystal panel having a second optical function layer (A2) and a second polarizing film (P2) sequentially disposed from the rear side of the first optical function layer (A1) and the second optical function layer (A2) At least one of the optical function layers is characterized in that it contains a dye and has a haze in the range of 0.2% to 2%. The liquid crystal panel of the present invention not only realizes a wide color gamut and low reflectance, but can also satisfy high contrast.

Description

Liquid crystal panels and liquid crystal displays

The present invention relates to a liquid crystal panel. The liquid crystal panel may form a liquid crystal display device. The above-mentioned liquid crystal panel and liquid crystal display device can be applied to various uses, and can be used together with an input device such as a touch panel applied on the viewing side of a liquid crystal display device, for example. As said touch panel, it can use suitably for touch panels, such as an optical method, an ultrasonic method, a capacitance method, and a resistive film method. In particular, it is suitably used for capacitive touch panels. The touch panel is not particularly limited, but is used, for example, for mobile phones, tablet computers, portable information terminals, and the like.

In a liquid crystal display device, it is indispensable to arrange polarizing elements on both sides of a liquid crystal cell due to its image forming method, and polarizing films are generally attached thereto. When attaching the said polarizing film to a liquid crystal cell, an adhesive is normally used. In addition, in the adhesion between the polarizing film and the liquid crystal cell, each material is usually adhered using an adhesive in order to reduce the loss of light. In such a case, a polarizing film with a pressure-sensitive adhesive layer formed in advance as a pressure-sensitive adhesive layer on one side of the polarizing film is generally used as the pressure-sensitive adhesive, since it has merits such as not requiring a drying step to fix the polarizing film.

In recent years, brightness and clarity (i.e., wide color gamut) have been demanded for image display devices, and organic EL display devices (OLED) have attracted attention, but wide color gamut has also been demanded for liquid crystal display devices. For example, as a method of wide color gamut of a liquid crystal display device, a polarizing film is applied to one side or both sides of the liquid crystal cell through an adhesive layer containing a dye exhibiting an absorption maximum wavelength in a specific wavelength range (560 to 610 nm). Laminated liquid crystal panels have been proposed (Patent Documents 1 and 2).

Japanese Unexamined Patent Publication No. 2011-039093 Japanese Unexamined Patent Publication No. 2014-092611

Since the said liquid crystal panel generally has a high reflectance, reduction of the reflectance is calculated|required. As a result of the present inventors examining the liquid crystal panels described in Patent Literatures 1 and 2, the liquid crystal panel has an advantage of reducing the reflectance in addition to the expansion of the color gamut, but a decrease in contrast was observed.

The present invention is a liquid crystal panel having a liquid crystal cell and a polarizing film and using an optical functional layer containing a pigment, and to provide a liquid crystal panel that not only realizes a wide color gamut and low reflectance, but also can satisfy high contrast. do. Another object of the present invention is to provide a liquid crystal display device using the above liquid crystal panel.

As a result of repeated intensive examinations to solve the above problems, the present inventors have found a liquid crystal panel equipped with a polarizing film having a liquid crystal cell of the following specific mode and a pigment-containing optical functional layer of a predetermined haze, and to complete the present invention. reached

That is, the present invention is an IPS mode liquid crystal cell,

A first optical functional layer and a first polarizing film sequentially disposed from the viewing side of the liquid crystal cell;

In the liquid crystal panel having a second optical functional layer and a second polarizing film sequentially disposed from the rear side of the liquid crystal cell,

It relates to a liquid crystal panel characterized in that at least one of the first optical function layer and the second optical function layer contains a dye and has a haze in the range of 0.2% to 2%.

In the above liquid crystal panel, it is preferable that at least the first optical function layer contains a dye and has a haze in the range of 0.3 to 2%.

In the above liquid crystal panel, it is preferable that the haze of the optical function layer containing the above dye is 0.2% to 1.5%.

In the liquid crystal panel, the dye having a maximum absorption wavelength in at least one of a wavelength range of 470 to 510 nm and a wavelength range of 570 to 610 nm can be used.

In the liquid crystal panel, the dye may be a tetraazaporphyrin-based dye.

In the above liquid crystal panel, it is preferable to contain 0.01 to 5 parts by weight of the pigment based on 100 parts by weight of the base polymer forming the resin layer of the optical function layer.

Further, the present invention relates to a liquid crystal display device characterized in that the above liquid crystal panel is used.

In the liquid crystal panel of this invention, the optical function layer containing a pigment|dye is used for bonding of a liquid crystal cell and a polarizing film. The optical function layer can adjust the color of the entire liquid crystal display device by absorbing light of a partial wavelength with a dye, and can improve clarity by wide color gamut. In particular, a dye having a maximum absorption wavelength in at least one of a wavelength range of 470 to 510 nm and a wavelength range of 570 to 610 nm is a wavelength range other than RGB (wavelength range of 470 to 510 nm and/or a wavelength range of 570 to 610 nm) It is effective for a wide color gamut because it can absorb unnecessary light emission for color expression in and suppress the unnecessary light emission.

In addition, in the liquid crystal panel of the present invention, since the optical functional layer used on at least one side of the liquid crystal cell has a dye, it is generally thought that in addition to wide color gamut of the liquid crystal panel, the reflectance reduction is possible, but the dye and the optical functional layer are formed. When compatibility of a material is bad, a haze raise arises in an optical function layer. And it turned out that light diffusion by the haze of an optical function layer affects a liquid crystal panel, lowers the contrast of a liquid crystal panel, and raises a reflectance. On the other hand, it was found that the influence of the haze on the contrast of the liquid crystal panel differs depending on the mode of the liquid crystal cell. For example, in the liquid crystal panel using the liquid crystal cell of VA mode, it turned out that the influence of the haze of an optical function layer on contrast is large. On the other hand, in the liquid crystal cell of IPS mode, the influence of the haze of an optical function layer on contrast was small compared with VA mode. From these findings, the present invention is an optical function layer in which the haze caused by containing a pigment in the optical function layer is controlled in the range of 0.2 to 2% for a liquid crystal cell of IPS mode, which has a small effect on contrast even when haze occurs. By applying , a liquid crystal panel (IPS mode) that not only realizes a wide color gamut and low reflectance but also satisfies high contrast was obtained.

In addition, in the liquid crystal panel of the present invention, since the liquid crystal panel having the above structure is used, in the optical function layer in which the pigment is sufficiently dissolved, the haze can be made very small, and the polarization characteristic is not greatly eliminated, In addition, since the polarization direction is controlled by the haze that minimizes the fluctuation of light distribution inherent in liquid crystal panels, low reflectance and high contrast can be satisfied while maintaining polarization and transmittance as a liquid crystal panel.

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

EMBODIMENT OF THE INVENTION Embodiment of the liquid crystal panel of this invention is described below, referring drawings. 1 is a cross-sectional view showing one embodiment of a liquid crystal panel of the present invention. The liquid crystal panel of FIG. 1 includes a liquid crystal cell (C) of IPS mode, a first optical functional layer (A1) and a first polarizing film (P1) sequentially disposed from the viewing side of the liquid crystal cell (C), It has the 2nd optical function layer (A2) and the 2nd polarizing film (P2) arrange|positioned sequentially from the back side of the liquid crystal cell (C).

Each member of the liquid crystal panel of the present invention is described below.

<liquid crystal cell>

As the liquid crystal cell C (structure of glass substrate/liquid crystal layer/glass substrate), an IPS mode liquid crystal cell is used. In addition, in the case where the liquid crystal cell is in the TN mode, STN mode, VA mode, etc. other than the IPS type mode, the effect of the haze of the optical function layer on these liquid crystal cells is large, and it is difficult to control the contrast.

The liquid crystal layer of the liquid crystal cell (C) is a liquid crystal layer containing homogeneously aligned liquid crystal molecules in the absence of an electric field. It is preferable to use nematic liquid crystals as liquid crystal molecules. The liquid crystal cell (C) has a configuration in which the liquid crystal layer is sandwiched between two transparent substrates. Inside or outside the liquid crystal cell, it can take the form of a liquid crystal panel with a built-in touch sensing function. Further, a color filter substrate can be provided on the liquid crystal cell (visible side transparent substrate). As a material forming the said transparent substrate, glass or a polymer film is mentioned, for example.

<Optical functional layer>

The optical function layer of the present invention is not particularly limited as long as it is a resin layer. As said resin layer, a film layer, an adhesive layer, etc. are mentioned. The optical function layer may be formed of a composition containing a base polymer. An optical function layer containing a pigment can be formed from a composition containing a base polymer and a pigment. Although a film layer, an adhesive layer, etc. are used as the first optical function layer and the second optical function layer of the present invention, the first optical function layer and the second optical function layer may be the same type of optical function layer, or a different type of It may be an optical function layer. In addition, the first optical function layer and the second optical function layer of the present invention can be formed of a plurality of optical function layers of the same type or different types.

As for the said 1st optical function layer and the 2nd optical function layer of this invention, at least one optical function layer contains a pigment|dye and has a haze in the range of 0.2 to 2% is used. As for the first optical function layer and the second optical function layer, one or both of which have a pigment and have a haze in the range of 0.2 to 2% can be used, but from the viewpoint of satisfying low reflectance and high contrast, at least It is preferable that the 1st optical function layer contains a pigment|dye and has a haze in the range of 0.2 to 2%. In addition, when the first optical function layer and the second optical function layer of the present invention are formed from a plurality of optical function layers of the same or different types, at least one layer of the plurality of layers contains a pigment and has a haze Use what is in the range of 0.2 to 2%.

Although the haze of the optical function layer having the pigment is controlled within the range of 0.2 to 2%, the haze is preferably 0.2 to 1.5%, more preferably 0.2 to 1.2%, and further 0.2 to 1%. It is desirable to be When the haze of the optical function layer having the dye is less than 0.2%, it is difficult to say that the superiority of the contrast to the prior art is high because there is no minute polarization control by the haze. On the other hand, when the haze of the optical function layer having the pigment exceeds 2%, the contrast of the liquid crystal panel cannot be maintained. When the haze of the optical function layer containing the dye is particularly controlled within a range of 0.2 to 1.5%, the contrast can be improved while increasing the haze compared to the optical function layer having no dye.

Further, when an optical function layer having the above dye (haze in the range of 0.2 to 2%) is used for either one of the first optical function layer and the second optical function layer of the present invention, the other optical function Since a high haze of a layer affects the contrast of a liquid crystal panel, it is recommended to use an optical function layer without a pigment or an optical function layer with a pigment (however, the haze is less than 0.2%) for the other optical function layer. desirable.

Adjustment of the haze (0.2 to 2%) of the optical function layer having the above-mentioned colorant can be performed by controlling the selection of the type of colorant, the content of the colorant, and the thickness of the optical function layer.

<pigment>

As the dye that the optical function layer of the present invention can contain, various dyes can be used. Examples of the dye include various compounds such as tetraazaporphyrin, porphyrin, cyanine, azo, pyromethene, squarylium, xanthene, oxonol, and squaraine. From the viewpoint of photochromic gamut, tetraazaporphyrin-based pigments, porphyrin-based pigments, cyanine-based pigments, squalium-based pigments, and squaraine-based pigments are preferred, and tetraazaporphyrin-based pigments are particularly preferred. Specifically, the dye is disclosed in Japanese Unexamined Patent Publication No. 2011-116818 or the like. As for the said pigment|dye, only 1 type may be used, and 2 or more types may be used together.

The dye preferably has a maximum absorption wavelength in at least one of a wavelength range of 470 to 510 nm and a wavelength range of 570 to 610 nm. A dye having a maximum absorption wavelength in the above wavelength range can absorb and suppress light emission unnecessary for color expression, and is effective for wide color gamut. As a dye having a maximum absorption wavelength in the above wavelength range, a tetraazaporphyrin-based dye can be suitably used. For example, as a dye exhibiting a maximum absorption wavelength in the wavelength range of 570 to 610 nm, tetraazaporphyrin-based compounds manufactured by Yamamoto Kasei Co., Ltd. (trade names: PD-320, PD311) and tetraazaporphyrin-based compounds manufactured by Yamada Chemical Industry Co., Ltd. (trade name: FDG-007) and the like. In addition, the measurement of the maximum absorption wavelength of the dye was performed with a spectrophotometer (V-570 manufactured by Nippon Bunko Co., Ltd.).

The content of the dye in the optical functional layer of the present invention is adjusted by the absorption wavelength range of the dye, the extinction coefficient and the type of the base polymer, but usually from the viewpoint of coexistence of wide color gamut and haze control, 100 weight of the base polymer It is preferably 0.01 to 5 parts by weight, more preferably 0.05 to 3 parts by weight, and more preferably 0.1 to 1 part by weight. In particular, the above range is preferable when a tetraazaporphyrin-based dye is used.

<Adhesive layer>

An adhesive layer is mentioned as an optical function layer of this invention. The pressure-sensitive adhesive layer may be formed of a pressure-sensitive adhesive composition containing an adhesive base polymer. The type of adhesive base polymer is not particularly limited, but examples include rubber-based polymers, (meth)acrylic polymers, silicone-based polymers, urethane-based polymers, vinylalkyl ether-based polymers, polyvinyl alcohol-based polymers, and polyvinylpyrrolidone-based polymers. , various polymers such as polyacrylamide-based polymers and cellulose-based polymers.

The pressure-sensitive adhesive composition of the present invention contains an adhesive base polymer as a main component. The main component refers to the component with the highest content ratio among the total solids contained in the pressure-sensitive adhesive composition, for example, a component that accounts for more than 50% by weight of the total solids contained in the pressure-sensitive adhesive composition, and a component that accounts for more than 70% by weight point

Among these adhesive base polymers, those having excellent optical transparency, appropriate wettability, cohesiveness, and adhesiveness, and excellent weather resistance, heat resistance, and the like are preferably used. As one exhibiting these characteristics, a (meth)acrylic polymer is preferably used. Hereinafter, an acrylic pressure-sensitive adhesive having, as a base polymer, a (meth)acryl-based polymer containing an alkyl (meth)acrylate as a monomer unit, which is a material for forming the pressure-sensitive adhesive layer, will be described.

<(meth)acrylic polymer>

The (meth)acrylic polymer usually contains an alkyl (meth)acrylate as a main component as a monomer unit. In addition, (meth)acrylate refers to an acrylate and/or methacrylate, and is synonymous with (meth) of the present invention.

As the alkyl (meth)acrylate constituting the main skeleton of the above-mentioned (meth)acrylic polymer, those having 1 to 18 carbon atoms in a linear or branched alkyl group can be exemplified. These can be used alone or in combination. It is preferable that the average carbon number of these alkyl groups is 3-9.

In addition, from the viewpoint of adhesive properties, durability, adjustment of phase difference, adjustment of refractive index, etc., alkyl (meth)acrylates containing an aromatic ring such as phenoxyethyl (meth)acrylate and benzyl (meth)acrylate can be used. there is.

In the above (meth)acrylic polymer, for the purpose of improving adhesiveness and heat resistance, at least one copolymerizable monomer having a polymerizable functional group having an unsaturated double bond such as a (meth)acryloyl group or a vinyl group is introduced by copolymerization. can do. Specific examples of such a copolymerization monomer include, for example, 2-hydroxyethyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, and 6-hydroxyhexyl (meth)acrylate. , hydroxyl groups such as 8-hydroxyoctyl (meth)acrylate, 10-hydroxydecyl (meth)acrylate, 12-hydroxylauryl (meth)acrylate or (4-hydroxymethylcyclohexyl)-methylacrylate containing monomers; carboxyl group-containing monomers such as (meth)acrylic acid, carboxyethyl (meth)acrylate, carboxypentyl (meth)acrylate, itaconic acid, maleic acid, fumaric acid, and crotonic acid; acid anhydride group-containing monomers such as maleic anhydride and itaconic anhydride; caprolactone adducts of acrylic acid; Contains sulfonic acid groups such as styrenesulfonic acid, allylsulfonic acid, 2-(meth)acrylamide-2-methylpropanesulfonic acid, (meth)acrylamidepropanesulfonic acid, sulfopropyl(meth)acrylate, and (meth)acryloyloxynaphthalenesulfonic acid monomer; Phosphoric acid group containing monomers, such as 2-hydroxyethyl acryloyl phosphate, etc. are mentioned.

In addition, (meth)acrylamide, N,N-dimethyl (meth)acrylamide, N-butyl (meth)acrylamide, N-methylol (meth)acrylamide, N-methylolpropane (meth)acrylamide, etc. (N-substituted) amide-based monomers; (meth)alkylaminoalkyl monomers such as aminoethyl (meth)acrylate, N,N-dimethylaminoethyl (meth)acrylate, and t-butylaminoethyl (meth)acrylate; alkoxyalkyl (meth)acrylate monomers such as methoxyethyl (meth)acrylate and ethoxyethyl (meth)acrylate; N-(meth)acryloyloxymethylenesuccinimide, N-(meth)acryloyl-6-oxyhexamethylenesuccinimide, N-(meth)acryloyl-8-oxyoctamethylenesuccinimide, N - Succinimide monomers such as acryloylmorpholine; maleimide monomers such as N-cyclohexylmaleimide, N-isopropylmaleimide, N-laurylmaleimide, and N-phenylmaleimide; N-methyl itaconimide, N-ethyl itaconimide, N-butyl itaconimide, N-octyl itaconimide, N-2-ethylhexyl itaconimide, N-cyclohexyl itaconimide Itaconimide-based monomers such as mead and N-laurylitaconimide are also exemplified as examples of monomers for modification.

Further, as the modifying monomer, vinyl acetate, vinyl propionate, N-vinylpyrrolidone, methylvinylpyrrolidone, vinylpyridine, vinylpiperidone, vinylpyrimidine, vinylpiperazine, vinylpyrazine, vinylpyrrole, vinylimidazole, vinyl monomers such as vinyloxazole, vinylmorpholine, N-vinylcarboxylic acid amides, styrene, α-methylstyrene, and N-vinylcaprolactam; cyanoacrylate-based monomers such as acrylonitrile and methacrylonitrile; Epoxy group-containing acrylic monomers, such as glycidyl (meth)acrylate; glycol-based acrylic ester monomers such as polyethylene glycol (meth)acrylate, polypropylene glycol (meth)acrylate, methoxyethylene glycol (meth)acrylate, and methoxypolypropylene glycol (meth)acrylate; Acrylic acid ester type monomers, such as (meth)acrylic acid tetrahydrofurfuryl, fluorine (meth)acrylate, silicone (meth)acrylate, and 2-methoxyethyl acrylate, etc. can also be used. Moreover, isoprene, butadiene, isobutylene, vinyl ether, etc. are mentioned.

Moreover, as a monomer which can be copolymerized other than the above, the silane type monomer containing a silicon atom etc. are mentioned. Examples of the silane-based monomer include 3-acryloxypropyltriethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, 4-vinylbutyltrimethoxysilane, 4-vinylbutyltriethoxysilane, and 8 -Vinyloctyltrimethoxysilane, 8-vinyloctyltriethoxysilane, 10-methacryloyloxydecyltrimethoxysilane, 10-acryloyloxydecyltrimethoxysilane, 10-methacryloyloxydecyl Triethoxysilane, 10-acryloyloxydecyltriethoxysilane, etc. are mentioned.

In addition, as a copolymerization monomer, tripropylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, bisphenol A diglycidyl ether di(meth) Acrylates, neopentyl glycol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate , dipentaerythritol hexa (meth) acrylate, caprolactone-modified dipentaerythritol hexa (meth) acrylate, etc. (meth) acrylic acid and polyhydric alcohol esters, such as (meth) acryloyl groups, unsaturated doubles such as vinyl groups, etc. Polyfunctional monomers having two or more bonds, or polyesters obtained by adding two or more unsaturated double bonds such as (meth)acryloyl groups and vinyl groups as functional groups such as monomer components to the backbone of polyesters, epoxies, urethanes, etc. ( Meta) acrylate, epoxy (meth) acrylate, urethane (meth) acrylate, etc. can also be used.

The (meth)acrylic polymer has an alkyl (meth)acrylate as a main component in terms of the weight ratio of all constituent monomers, and the ratio of the copolymerized monomer in the (meth)acrylic polymer is not particularly limited, but the ratio of the copolymerized monomer Silver is preferably about 0 to 20%, about 0.1 to 15%, and more preferably about 0.1 to 10% in the weight ratio of all constituent monomers.

Among these copolymerization monomers, a hydroxyl group-containing monomer and a carboxyl group-containing monomer are preferably used from the viewpoint of adhesiveness and durability. A hydroxyl group-containing monomer and a carboxyl group-containing monomer can be used together. These copolymerization monomers serve as a reaction point with the crosslinking agent when the pressure-sensitive adhesive composition contains the crosslinking agent. A hydroxyl group-containing monomer, a carboxyl group-containing monomer, etc. are highly reactive with an intermolecular cross-linking agent, and therefore are preferably used for improving the cohesiveness and heat resistance of the resulting pressure-sensitive adhesive layer. A hydroxyl group-containing monomer is preferable in terms of reworkability, and a carboxyl group-containing monomer is preferable in terms of both durability and reworkability.

When a hydroxyl group-containing monomer is contained as the copolymerization monomer, the ratio thereof is preferably 0.01 to 15% by weight, more preferably 0.03 to 10% by weight, still more preferably 0.05 to 7% by weight. When a carboxyl group-containing monomer is contained as the copolymerization monomer, the ratio is preferably 0.05 to 10% by weight, more preferably 0.1 to 8% by weight, still more preferably 0.2 to 6% by weight.

The (meth)acrylic polymer of the present invention usually has a weight average molecular weight in the range of 500,000 to 3,000,000. Considering durability, especially heat resistance, it is preferable to use a weight average molecular weight of 700,000 to 2.700,000. Moreover, it is preferable that it is 800,000-2.500,000. When the weight average molecular weight is smaller than 500,000, it is not preferable from the viewpoint of heat resistance. In addition, when the weight average molecular weight is larger than 3 million, a large amount of diluting solvent is required to adjust the viscosity for coating, which is not preferable because cost increases. In addition, a weight average molecular weight is measured by GPC (gel permeation chromatography) and says the value computed by polystyrene conversion.

For production of such a (meth)acrylic polymer, known production methods such as solution polymerization, radiation polymerization such as UV polymerization, bulk polymerization, emulsion polymerization, and various radical polymerizations can be appropriately selected. In addition, any of a random copolymer, a block copolymer, and a graft copolymer may be sufficient as the obtained (meth)acrylic polymer.

In addition, in solution polymerization, as a polymerization solvent, for example, ethyl acetate, toluene, etc. are used. As a specific example of solution polymerization, the reaction is usually carried out under reaction conditions of about 5 to 30 hours at about 50 to 70° C. with the addition of a polymerization initiator under an inert gas stream such as nitrogen.

Polymerization initiators, chain transfer agents, emulsifiers, etc. used in radical polymerization are not particularly limited and may be appropriately selected and used. In addition, the weight average molecular weight of the (meth)acrylic polymer can be controlled by the amount of polymerization initiator and chain transfer agent and the reaction conditions, and the appropriate amount of the amount is adjusted according to these types.

Examples of the radical polymerization initiator include 2,2'-azobisisobutyronitrile, 2,2'-azobis(2-amidinopropane) dihydrochloride, and 2,2'-azobis[2-(5). -Methyl-2-imidazolin-2-yl) propane] dihydrochloride, 2,2'-azobis (2-methylpropionamidine) disulfate, 2,2'-azobis (N, N'- azo initiators such as dimethylene isobutylamidine), 2,2'-azobis[N-(2-carboxyethyl)-2-methylpropionamidine] hydrate (VA-057, manufactured by Wako Pure Chemical Industries, Ltd.), and Persulfates such as potassium sulfate and ammonium persulfate, di(2-ethylhexyl)peroxydicarbonate, di(4-t-butylcyclohexyl)peroxydicarbonate, di-sec-butylperoxydicarbonate, t-butylperoxy Neodecanoate, t-hexylperoxypivalate, t-butylperoxypivalate, dilauroyl peroxide, di-n-octanoylperoxide, 1,1,3,3-tetramethylbutylperoxy- 2-ethylhexanoate, di(4-methylbenzoyl)peroxide, dibenzoylperoxide, t-butylperoxyisobutyrate, 1,1-di(t-hexylperoxy)cyclohexane, t-butylhydro peroxide-based initiators such as peroxide and hydrogen peroxide, redox-based initiators obtained by combining a peroxide and a reducing agent, such as a combination of a persulfate and sodium hydrogen sulfite, a combination of a peroxide and sodium ascorbate, and the like, but are not limited thereto. .

The radical polymerization initiator may be used alone or in combination of two or more, but the content as a whole is preferably about 0.005 to 1 part by weight, and about 0.02 to 0.5 part by weight, based on 100 parts by weight of the monomer. it is more preferable

Examples of the chain transfer agent include lauryl mercaptan, glycidyl mercaptan, mercaptoacetic acid, 2-mercaptoethanol, thioglycolic acid, 2-ethylhexyl thioglycolic acid, 2,3-dimercapto-1 - Propanol etc. are mentioned. Although a chain transfer agent may be used individually or may mix and use 2 or more types, content as a whole is about 0.1 part by weight or less with respect to 100 parts by weight of the total amount of monomer components.

In addition, as an emulsifier used in the case of emulsion polymerization, for example, sodium lauryl sulfate, ammonium lauryl sulfate, sodium dodecylbenzenesulfonate, polyoxyethylene alkyl ether ammonium sulfate, polyoxyethylene alkyl phenyl ether sodium sulfate, etc. and nonionic emulsifiers such as anionic emulsifiers, polyoxyethylene alkyl ethers, polyoxyethylene alkyl phenyl ethers, polyoxyethylene fatty acid esters, and polyoxyethylene-polyoxypropylene block polymers. These emulsifiers may be used alone or in combination of two or more.

In addition, as a reactive emulsifier, as an emulsifier into which a radical polymerizable functional group such as a propenyl group or an allyl ether group is introduced, specifically, for example, Aquaron HS-10, HS-20, KH-10, BC-05, BC -10, BC-20 (above, all made by Daiichi Kogyo Seiyaku Co., Ltd.), Adeka Ria Sof SE10N (made by Asahi Denka Kogyo Co., Ltd.), etc. Reactive emulsifiers are preferred because they are introduced into the polymer chain after polymerization and thus have good water resistance. The amount of the emulsifier used is more preferably 0.3 to 5 parts by weight, and 0.5 to 1 part by weight based on polymerization stability and mechanical stability, based on 100 parts by weight of the total amount of the monomer components.

<Crosslinking agent>

Moreover, in this invention, a crosslinking agent can be contained in the adhesive composition which forms an adhesive layer. As the crosslinking agent, an organic type crosslinking agent or a polyfunctional metal chelate can be used. Examples of the organic crosslinking agent include isocyanate crosslinking agents, peroxide crosslinking agents, epoxy crosslinking agents, and imine crosslinking agents. A polyfunctional metal chelate is one in which a multivalent metal is covalently bonded or coordinated with an organic compound. Examples of the polyvalent metal atoms include Al, Cr, Zr, Co, Cu, Fe, Ni, V, Zn, In, Ca, Mg, Mn, Y, Ce, Sr, Ba, Mo, La, Sn, Ti, and the like. there is. Examples of atoms in organic compounds that form a covalent bond or coordinate bond include oxygen atoms, and examples of organic compounds include alkyl esters, alcohol compounds, carboxylic acid compounds, ether compounds, and ketone compounds.

As the compound according to the isocyanate-based crosslinking agent, for example, isocyanate monomers such as tolylene diisocyanate, chlorphenylene diisocyanate, tetramethylene diisocyanate, xylylene diisocyanate, diphenylmethane diisocyanate, hydrogenated diphenylmethane diisocyanate, and the like Isocyanate compounds, isocyanurates, biuret-type compounds obtained by adding these isocyanate monomers to trimethylolpropane, etc., and also urethane prepolymer types obtained by addition reactions such as polyether polyols, polyester polyols, acrylic polyols, polybutadiene polyols, and polyisoprene polyols. Isocyanate etc. are mentioned. Especially preferably, it is a polyisocyanate compound, and it is 1 type selected from the group which consists of hexamethylene diisocyanate, hydrogenated xylylene diisocyanate, and isophorone diisocyanate, or a polyisocyanate compound derived from it. Here, hexamethylene diisocyanate, hydrogenated xylylene diisocyanate, isophorone diisocyanate, and isophorone diisocyanate are selected from the group consisting of hexamethylene diisocyanate, hydrogenated xylylene diisocyanate, and isophorone diisocyanate, or a polyisocyanate compound derived therefrom. phorone diisocyanate, polyol-modified hexamethylene diisocyanate, polyol-modified hydrogenated xylylene diisocyanate, trimer-type hydrogenated xylylene diisocyanate, and polyol-modified isophorone diisocyanate. The exemplified polyisocyanate compounds are particularly preferable because they contribute to the speed of crosslinking because the reaction with the hydroxyl group proceeds rapidly using an acid or base contained in the polymer as a catalyst.

As the peroxide, any peroxide can be suitably used as long as it generates radically active species by heating or light irradiation to promote crosslinking of the base polymer of the pressure-sensitive adhesive composition. It is preferable to use a peroxide, and it is more preferable to use a peroxide at 90°C to 140°C.

Examples of the peroxide include di(4-t-butylcyclohexyl)peroxydicarbonate (half-life temperature: 92.1°C for 1 minute), di-sec-butylperoxydicarbonate (half-life temperature: 92.4°C for 1 minute), and t -Butylperoxyneodecanoate (half-life temperature for 1 minute: 103.5°C), t-hexylperoxypivalate (half-life temperature for 1 minute: 109.1°C), t-butylperoxypivalate (half-life temperature for 1 minute: 110.3°C) ), dilauroyl peroxide (1 minute half-life temperature: 116.4 ° C), di-n-octanoyl peroxide (1 minute half-life temperature: 117.4 ° C), 1,1,3,3-tetramethylbutylperoxy-2 -Ethylhexanoate (half-life temperature for 1 minute: 124.3°C), di(4-methylbenzoyl)peroxide (half-life temperature for 1 minute: 128.2°C), dibenzoyl peroxide (half-life temperature for 1 minute: 130.0°C), t- Butylperoxyisobutyrate (1-minute half-life temperature: 136.1°C), 1,1-di(t-hexylperoxy)cyclohexane (1-minute half-life temperature: 149.2°C), and the like. Among them, di(4-t-butylcyclohexyl) peroxydicarbonate (half-life temperature for 1 minute: 92.1 ° C.), dilauroyl peroxide (half-life temperature for 1 minute: 116.4 ° C.), Benzoyl peroxide (half-life temperature for 1 minute: 130.0°C) and the like are preferably used.

In addition, the half-life of peroxide is an indicator of the decomposition rate of peroxide, and refers to the time until the remaining amount of peroxide is halved. The decomposition temperature for obtaining a half-life at an arbitrary time and the half-life time at an arbitrary temperature are described in manufacturer catalogs and the like, for example, Nippon Yushi Co., Ltd.'s "Organic Peroxide Catalog 9th Edition (2003) May)”, etc.

The amount of the crosslinking agent used is preferably 20 parts by weight or less, preferably 0.01 to 20 parts by weight, and more preferably 0.03 to 10 parts by weight, based on 100 parts by weight of the base polymer such as a (meth)acrylic polymer in the pressure-sensitive adhesive composition. In addition, when the amount of the crosslinking agent is greater than 20 parts by weight, moisture resistance is not sufficient, and peeling easily occurs in a reliability test or the like.

In addition, the pressure-sensitive adhesive composition forming the pressure-sensitive adhesive layer of the present invention may contain a silane coupling agent. Durability can be improved by using a silane coupling agent. As a silane coupling agent, specifically, for example, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 2-(3 Epoxy group-containing silane coupling agents such as ,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-aminopropyltrimethoxysilane, N-2-(aminoethyl)-3-aminopropylmethyldimethoxysilane, 3-tri Amino group-containing silane coupling agents such as ethoxysilyl-N-(1,3-dimethylbutylidene)propylamine and N-phenyl-γ-aminopropyltrimethoxysilane, 3-acryloxypropyltrimethoxysilane, 3 - Silane coupling agents containing (meth)acryl groups such as methacryloxypropyl triethoxysilane and silane coupling agents containing isocyanate groups such as 3-isocyanate propyltriethoxysilane; and the like.

The silane coupling agent may be used alone or in combination of two or more, but the content as a whole is 0.001 to 5 parts by weight of the silane coupling agent relative to 100 parts by weight of the base polymer such as the (meth)acrylic polymer. part is preferable, more preferably 0.01 to 1 part by weight, more preferably 0.02 to 1 part by weight, more preferably 0.05 to 0.6 part by weight. It is an amount that improves durability and appropriately maintains the adhesive strength to optical members such as liquid crystal cells.

Further, in the present invention, polyether-modified silicone can be blended in the pressure-sensitive adhesive composition forming the pressure-sensitive adhesive layer. As polyether-modified silicone, what is disclosed in Unexamined-Japanese-Patent No. 2010-275522 can be used, for example.

Further, in the present invention, the pressure-sensitive adhesive composition forming the pressure-sensitive adhesive layer may contain other known additives, for example, powders such as colorants and pigments, dyes, surfactants, plasticizers, tackifiers, surface lubricants, Leveling agents, softening agents, anti-aging agents, antioxidants, light stabilizers, ultraviolet absorbers, polymerization inhibitors, inorganic or organic fillers, metal powders, particulates, thin materials, etc. can be added as appropriate depending on the use. Further, within a controllable range, a redox system to which a reducing agent is added may be employed.

The pressure-sensitive adhesive layer is formed by the pressure-sensitive adhesive composition, but in forming the pressure-sensitive adhesive layer, it is preferable to adjust the addition amount of the crosslinking agent and sufficiently consider the effects of the crosslinking treatment temperature and crosslinking treatment time.

Depending on the crosslinking agent used, the crosslinking treatment temperature or crosslinking treatment time can be adjusted. The crosslinking treatment temperature is preferably 170°C or lower.

In addition, such a crosslinking treatment may be performed at the temperature during the drying step of the pressure-sensitive adhesive layer, or may be performed by providing a separate crosslinking treatment 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.

As a method of forming the pressure-sensitive adhesive layer, for example, a method of applying the pressure-sensitive adhesive composition to a separator or the like subjected to peeling treatment, forming an pressure-sensitive adhesive layer by drying and removing a polymerization solvent, and then transferring the pressure-sensitive adhesive to a polarizing film, or a method of transferring the pressure-sensitive adhesive to a polarizing film It is produced by a method of applying a composition, drying and removing a polymerization solvent or the like to form an adhesive layer on a polarizing film, or the like. Moreover, in application|coating of an adhesive, you may newly add 1 or more types of solvents other than a polymerization solvent suitably.

As the separator subjected to the peeling treatment, a silicone peeling liner is preferably used. In the step of forming the pressure-sensitive adhesive layer by applying and drying the adhesive composition of the present invention on such a liner, as a method of drying the pressure-sensitive adhesive, an appropriate method can be employed as appropriate depending on the purpose. Preferably, a method of overheating the coating film is used. The heating and drying temperature is preferably 40°C to 200°C, more preferably 50°C to 180°C, and particularly preferably 70°C to 170°C. By setting the heating temperature within the above range, a pressure-sensitive adhesive having excellent adhesive properties can be obtained.

As for the drying time, an appropriate time may be employed. The drying time is preferably 5 seconds to 20 minutes, more preferably 5 seconds to 10 minutes, and particularly preferably 10 seconds to 5 minutes.

Moreover, an adhesive layer can be formed after forming an anchor layer on the surface of a polarizing film, or performing various adhesion-facilitating treatments, such as a corona treatment and a plasma treatment. Moreover, you may give an adhesion-facilitating process to the surface of an adhesive layer.

Various methods are used as a method of forming the pressure-sensitive adhesive layer. Specifically, for example, roll coat, kiss roll coat, gravure coat, reverse coat, roll brush, spray coat, dip roll coat, bar coat, knife coat, air knife coat, curtain coat, lip coat, die coater, etc. Methods, such as an extrusion coating method, are mentioned.

The thickness of the pressure-sensitive adhesive layer is not particularly limited, and is, for example, about 1 to 100 μm. Preferably it is 2-50 micrometers, More preferably, it is 2-40 micrometers, More preferably, it is 5-35 micrometers. It is preferable that the thickness of the adhesive layer containing the said dye is 30 micrometers or less in terms of adjusting the haze of the said adhesive layer. The thickness of the pressure-sensitive adhesive layer is preferably 28 μm or less, and more preferably 23 μm or less.

When the pressure-sensitive adhesive layer is exposed, the pressure-sensitive adhesive layer may be protected with a sheet (separator) subjected to peeling treatment until practical use.

<Film layer>

Moreover, a film layer is mentioned as an optical function layer of this invention, The said film layer can be formed from the composition containing the base polymer for film formation. As the material of the base polymer forming the film layer, the same material as the material constituting the later-described transparent protective film can be exemplified. In particular, cellulosic resins such as triacetyl cellulose, polyester resins, (meth)acrylic resins, cyclic polyolefin resins (norbornene resins), and the like are preferably used as the material. The film layer can be suitably applied to the polarizing film using an adhesive, pressure-sensitive adhesive, or the like.

Various methods can be adopted as a method for forming a film layer containing a dye. For example, when dissolving the pellet of the said resin material in a solvent, a pigment|dye is mixed, a composition is prepared, and a film layer can be manufactured by casting or extruding the said composition. At that time, the film layer can be molded to an appropriate thickness. In preparation of the said composition, additives can be mix|blended suitably.

The thickness of the film layer is not particularly limited, and is the same as that of the pressure-sensitive adhesive layer, and is, for example, about 1 to 100 μm. Preferably it is 2-50 micrometers, More preferably, it is 2-40 micrometers, More preferably, it is 5-35 micrometers. The separator can also be applied to a film layer.

Examples of materials constituting the separator include plastic films such as polyethylene, polypropylene, polyethylene terephthalate, and polyester films, porous materials such as paper, cloth, and nonwoven fabric, nets, foam sheets, metal foils, and laminates thereof. Although suitable thin sheets such as the like are mentioned, a plastic film is preferably used from the point of being excellent in surface smoothness.

The plastic film is not particularly limited as long as it is a film capable of protecting the optical function layer (in particular, the pressure-sensitive adhesive layer), and examples thereof include a polyvinyl alcohol film, a polyethylene film, a polypropylene film, a polybutene film, and a polybutadiene film. films, polymethylpentene films, polyvinyl chloride films, vinyl chloride copolymer films, polyethylene terephthalate films, polybutylene terephthalate films, polyurethane films, ethylene-vinyl acetate copolymer films and the like.

The thickness of the separator is usually about 5 to 200 μm, preferably about 5 to 100 μm. If necessary, the separator may also be subjected to release and antifouling treatment using a silicone-based, fluorine-based, long-chain alkyl-based or fatty acid amide-based release agent, silica powder, or the like, or antistatic treatment such as coating, kneading, or vapor deposition. In particular, peelability from the optical function layer (in particular, the pressure-sensitive adhesive layer) can be further improved by appropriately subjecting the surface of the separator to a peeling treatment such as silicone treatment, long-chain alkyl treatment, or fluorine treatment.

Moreover, when the said optical function layer is an adhesive layer, although the said adhesive layer is used at the time of bonding to a liquid crystal cell, it can be used as a polarizing film with an adhesive layer in which the adhesive layer was previously formed in the polarizing film. The peeling-treated sheet|seat used in preparation of the polarizing film with an adhesive layer can be used as a separator of a polarizing film with an adhesive layer as it is, and simplification in a process surface is possible.

<Polarizing film>

As the first polarizing film and the second polarizing film of the present invention, those having a transparent protective film on one side or both sides of the polarizer are generally used.

The polarizer is not particularly limited, and various types of polarizers can be used. As the polarizer, for example, a dichroic substance such as iodine or a dichroic dye is adsorbed to a hydrophilic polymer film such as a polyvinyl alcohol-based film, a partially formalized polyvinyl alcohol-based film, or an ethylene-vinyl acetate copolymer-based partially saponified film. and polyene-based oriented films such as uniaxially stretched ones, dehydrated polyvinyl alcohol, and dehydrochlorinated polyvinyl chloride. Among these, a polyvinyl alcohol-based film and a polarizer made of a dichroic substance such as iodine are suitable. The thickness of these polarizers is not particularly limited, but is generally about 80 μm or less.

A polarizer in which a polyvinyl alcohol-based film is dyed with iodine and uniaxially stretched can be produced by, for example, dyeing a polyvinyl alcohol-based film by immersing it in an aqueous solution of iodine and stretching it 3 to 7 times the original length. It can also be immersed in aqueous solution, such as potassium iodide which may contain boric acid, zinc sulfate, zinc chloride, etc. as needed. Further, if necessary, the polyvinyl alcohol-based film may be immersed in water and washed with water before dyeing. By washing the polyvinyl alcohol-based film with water, stains and anti-blocking agents on the surface of the polyvinyl alcohol-based film can be washed away, and unevenness such as dyeing unevenness can be prevented by swelling the polyvinyl alcohol-based film. Stretching may be performed after dyeing with iodine, stretching may be performed while dyeing, or stretching may be followed by dyeing with iodine. It can extend|stretch also in aqueous solution, such as boric acid and potassium iodide, or a water bath.

Moreover, as a polarizer, a thin polarizer with a thickness of 10 μm or less can be used. From the viewpoint of thinning, the thickness is preferably 1 to 7 µm. It is preferable that such a thin polarizer has little thickness variation, excellent visibility, and excellent durability due to little dimensional change, and also thinning the thickness as a polarizing film.

As a thin polarizer, typically, Japanese Unexamined Patent Publication No. 51-069644, Japanese Unexamined Patent Publication No. 2000-338329, WO2010/100917 pamphlet, specification of PCT/JP2010/001460, or Japanese Patent Application No. 2010-269002 and the thin polarizing film described in the specification of Japanese Patent Application No. 2010-263692. These thin polarizing films can be obtained by a manufacturing method including a step of stretching a polyvinyl alcohol-based resin (hereinafter also referred to as a PVA-based resin) layer and a resin substrate for stretching in a laminated state and a step of dyeing. According to this production method, even if the PVA-based resin layer is thin, it can be stretched without problems such as breakage due to stretching because it is supported by the resin base material for stretching.

Among the production methods including a step of stretching and a step of dyeing in the state of a laminate, the thin polarizing film can be stretched at a high magnification and the polarization performance can be improved. 001460, or the specification of Japanese Patent Application No. 2010-269002, or the specification of Japanese Patent Application No. 2010-263692, preferably obtained by a manufacturing method including a step of stretching in a boric acid aqueous solution, particularly Japanese Patent Application No. 2010-269002 It is preferable to obtain by the manufacturing method including the process of carrying out auxiliary air extension before extending|stretching in the boric acid aqueous solution which is described in the specification or the specification of Japanese Patent Application No. 2010-263692.

As a material constituting the transparent protective film, for example, a thermoplastic resin excellent in transparency, mechanical strength, thermal stability, moisture barrier property, isotropy, etc. is used. Specific examples of such thermoplastic resins include cellulose resins such as triacetyl cellulose, polyester resins, polyethersulfone resins, polysulfone resins, polycarbonate resins, polyamide resins, polyimide resins, polyolefin resins, (meth)acrylic resins, and cyclic resins. polyolefin resins (norbornene resins), polyarylate resins, polystyrene resins, polyvinyl alcohol resins, and mixtures thereof. In addition, a transparent protective film is bonded to one side of the polarizer by an adhesive layer, but to the other side, as a transparent protective film, a thermosetting resin such as (meth)acrylic, urethane, acrylurethane, epoxy, silicone, or ultraviolet curable resin can be used. there is. One or more suitable additives may be contained in the transparent protective film. Examples of additives include ultraviolet absorbers, antioxidants, lubricants, plasticizers, release agents, anti-coloring agents, flame retardants, nucleating agents, antistatic agents, pigments, colorants and the like. 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, even 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 risk that the high transparency originally possessed by the thermoplastic resin may not be sufficiently expressed.

The thickness of the transparent protective film is not particularly limited, and is, for example, about 10 to 90 μm. Preferably it is 15 to 60 μm, more preferably 20 to 50 μm.

A functional layer (surface layer) such as a hard coat layer, an antireflection layer, an antisticking layer, a diffusion layer or an antiglare layer may be formed on the surface of the transparent protective film to which the polarizer is not adhered.

The adhesive used for bonding the polarizer and the transparent protective film is not particularly limited as long as it is optically transparent, and various types of water-based, solvent-based, hot-melt-based, radical-curable, and cationic-curable adhesives can be used, but water-based adhesives or radical-curable adhesives Suitable.

<liquid crystal panel>

The liquid crystal panel of the present invention, as described above, a liquid crystal cell of IPS mode, a first optical functional layer and a first polarizing film sequentially disposed from the viewing side of the liquid crystal cell, and sequentially disposed from the rear side of the liquid crystal cell and a second optical functional layer and a second polarizing film. In addition to the polarizing film, other optical layers may be applied to the formation of the liquid crystal panel. Although the optical layer is not particularly limited, for example, a reflection plate, a transflective plate, a retardation plate (including a wave plate such as 1/2 or 1/4), a visual compensation film, a liquid crystal panel such as a brightness enhancement film. An optical layer that may be used for formation of may be used in one layer or two or more layers on the viewing side and/or the back side of the liquid crystal cell.

<Liquid crystal display device>

The liquid crystal panel is used in the liquid crystal display device, and is formed by appropriately assembling components such as a lighting system and attaching a drive circuit as needed. Further, in the formation of the liquid crystal display device, for example, appropriate parts such as a diffusion plate, an antiglare layer, an antireflection film, a protective plate, a prism array, a lens array sheet, a light diffusion plate, and a backlight are formed in one or two layers at appropriate locations. More than one layer can be placed. In addition, an appropriate liquid crystal display device such as one using a backlight or a reflector for the lighting system can be formed.

(Example)

The present invention will be specifically described below with reference to examples, but the present invention is not limited by these examples. In addition, all parts and % in each case are based on weight. The room temperature conditions, which are not particularly specified below, are all 23°C and 65% RH.

<Measurement of weight average molecular weight of (meth)acrylic polymer>

The weight average molecular weight (Mw) of the (meth)acrylic polymer was measured by gel permeation chromatography (GPC). Mw/Mn was also measured in the same way.

・Analyzer: Tosoh Corporation, HLC-8120GPC

Column: Tosoh Corporation, G7000H _XL +GMH _XL +GMH _XL

・Column size: 7.8 mmφ × 30 cm each, 90 cm in total

Column temperature: 40℃

・Flow rate: 0.8mL/min

・Injection amount: 100 μL

・Eluent: tetrahydrofuran

Detector: Differential refractometer (RI)

·Standard sample: polystyrene

Comparative Example 1

<Production of polarizing film>

In order to produce a thin polarizing layer, first, a stretched laminate is produced by air-assisted stretching at a stretching temperature of 130° C. for a laminate in which a 9 μm thick PVA layer is formed on an amorphous PET substrate, and then a stretched laminate is formed. A colored laminate is produced by dyeing, and the colored laminate is stretched in boric acid at a stretching temperature of 65 ° C. so that the total draw ratio is 5.94 times. An optical film laminate was produced. PVA molecules of the PVA layer formed on the amorphous PET substrate by this two-step stretching are highly oriented, and iodine adsorbed by dyeing forms a highly functional polarizing layer oriented in one direction as a polyiodine ion complex. An optical film laminate comprising a 4 μm PVA layer could be produced. In addition, while a polyvinyl alcohol-based adhesive is applied to the surface of the polarizing layer of the optical film laminate, a saponified acrylic resin film having a thickness of 40 μm is bonded, and then the amorphous PET substrate is peeled off to form a polarizing film using a thin polarizer. has produced This is called a thin polarizing film.

<Preparation of (meth)acrylic polymer>

A monomer mixture containing 100 parts of butyl acrylate, 0.01 part of 2-hydroxyethyl acrylate, and 5 parts of acrylic acid was charged into a reaction vessel equipped with a cooling tube, a nitrogen inlet tube, a thermometer and a stirring device. In addition, 0.1 part of 2,2'-azobisisobutyronitrile as a polymerization initiator with respect to 100 parts of the monomer mixture was added together with 100 parts of ethyl acetate, nitrogen gas was introduced while gently stirring, and after nitrogen substitution, the flask The polymerization reaction was carried out for 8 hours while maintaining the liquid temperature at around 55°C to prepare an acrylic polymer solution (solid content concentration: 30% by weight) with a weight average molecular weight (Mw) of 1.8 million and Mw/Mn = 4.1.

(Preparation of adhesive composition)

Based on 100 parts of the solid content of the acrylic polymer solution prepared above, 0.3 parts of benzoyl peroxide (trade name Nyper BMT, manufactured by Nippon Yushi Co., Ltd.) and 1 part of isocyanate-based crosslinking agent (trade name Coronate L, manufactured by Tosoh Co., Ltd.) were blended to form an adhesive composition got

(Production of polarizing film with pressure-sensitive adhesive layer)

The pressure-sensitive adhesive composition was uniformly applied with an applicator to the surface of a polyethylene terephthalate film release substrate (MRF38CK manufactured by Mitsubishi Juici Co., Ltd.) treated with a silicone-based release agent, and dried in an air circulation constant temperature oven at 155 ° C. for 2 minutes to obtain a thickness of 20 An adhesive layer of μm was formed. A polarizing film with a pressure-sensitive adhesive layer was produced by transferring the pressure-sensitive adhesive layer having the above dye onto the surface of the polarizer (PVA layer) of the thin-shaped polarizing film.

(Production of liquid crystal panel in IPS mode)

A liquid crystal panel (liquid crystal panel including a liquid crystal cell of IPS mode) was taken out from a liquid crystal TV (43UF7710) manufactured by LG Electronics, and the polarizing film with an adhesive layer on the visual recognition side was removed from the liquid crystal cell. After peeling the separator from the adhesive layer of the polarizing film with an adhesive layer produced above on the part of the liquid crystal cell from which the polarizing film with an adhesive layer was removed, the adhesive layer of the polarizing film with an adhesive layer was pasted to form an IPS mode liquid crystal panel. made

Example 1

In the preparation of the pressure-sensitive adhesive composition of Comparative Example 1, with respect to 100 parts of the solid content of the acrylic polymer solution, further, a tetraazaporphyrin-based dye (trade name PD-320 manufactured by Yamamoto Kasei Co., Ltd.: has a maximum absorption wavelength at a wavelength of 595 nm) 0.25 A polarizing film with an adhesive layer was produced in the same manner as in Example 1 except that the parts were blended, and an IPS mode liquid crystal panel was also produced using the polarizing film with an adhesive layer.

Example 2

In the preparation of the pressure-sensitive adhesive composition of Comparative Example 1, tetraazaporphyrin-based dye was added to 100 parts of the solid content of the acrylic polymer solution, trade name FDG-007 manufactured by Yamada Kagaku Kogyo Co., Ltd. (has a maximum absorption wavelength at a wavelength of 595 nm) Except having mix|blended 0.5 part, the polarizing film with an adhesive layer was produced similarly to Example 1, and also the liquid crystal panel of IPS mode was produced using the said polarizing film with an adhesive layer.

Comparative Example 2

In the preparation of the pressure-sensitive adhesive composition of Example 1, 0.25 part of a cyanine dye (trade name FDB-008 manufactured by Yamada Chemical Co., Ltd.: has a maximum absorption wavelength at a wavelength of 495 nm) was blended with respect to 100 parts of solid content of the acrylic polymer solution. Except having done it, the polarizing film with an adhesive layer was produced similarly to Example 1, and also the liquid crystal panel of IPS mode was produced using the said polarizing film with an adhesive layer.

Reference Comparative Example 1

(Polarizing film with retardation film)

In preparation of the polarizing film of Comparative Example 1, after producing a thin polarizing film, a polyvinyl alcohol-based adhesive was applied to the polarizer surface of the thin polarizing film and a retardation film having a thickness of 40 μm (Zeonor film manufactured by Nippon Zeon, front side). Retardation 52nm, thickness retardation 125nm) were pasted, and the polarizing film with retardation film was produced.

(Production of polarizing film with pressure-sensitive adhesive layer)

Next, using the same adhesive composition as in Comparative Example 1, an adhesive layer was formed on the retardation film side of the polarizing film with retardation film in the same manner as in Comparative Example 1, and a polarizing film with an adhesive layer (with retardation film) was produced.

(Production of liquid crystal panel in VA mode)

A liquid crystal panel (liquid crystal panel including a liquid crystal cell of VA mode) was taken out from a liquid crystal TV (UN48JU6350F) manufactured by Samsung Corporation, and furthermore, the polarizing film with an adhesive layer on the visual recognition side was removed from the liquid crystal cell. On the part of the liquid crystal cell from which the polarizing film with the pressure-sensitive adhesive layer was removed, after peeling the separator from the pressure-sensitive adhesive layer of the polarizing film with the pressure-sensitive adhesive layer (with the phase difference film) produced above, the polarizing film with the pressure-sensitive adhesive layer (with the phase difference film) A liquid crystal panel in VA mode was produced by attaching an adhesive layer.

Reference Comparative Example 2

In Reference Comparative Example 1, as an adhesive composition, 0.25 part of a porphyrin-based dye (trade name PD-320 manufactured by Yamamoto Kasei Co., Ltd.: has a maximum absorption wavelength at a wavelength of 595 nm) was blended with respect to 100 parts of the solid content of the acrylic polymer solution. A polarizing film with a pressure-sensitive adhesive layer (with a phase difference film) was produced in the same manner as in Reference Comparative Example 1 except for using, and a liquid crystal panel in VA mode was produced using the polarizing film with a pressure-sensitive adhesive layer (with a phase difference film).

The following evaluation was performed about the adhesive layer and liquid crystal panel obtained by the said Example and comparative example (including comparative reference example). Table 1 shows the evaluation results.

(Measurement of haze (internal haze) of pressure-sensitive adhesive layer)

The pressure-sensitive adhesive composition used in each example was uniformly applied to one side of alkali-free glass having a total light transmittance of 93.3% and a haze of 0.1% with an applicator, and then dried in an air circulation type constant temperature oven at 155° C. for 2 minutes to obtain a thickness of 20 μm. The haze of what formed the adhesive layer was measured with the haze meter (MH-150 made by Murakami Color Technology Laboratory). In the measurement by a haze meter, it arrange|positioned so that the adhesive layer side might become the light source side. Since the haze value of the alkali-free glass was 0.1%, the value obtained by subtracting 0.1% from the measured value was used as the haze value.

(Measurement of contrast of liquid crystal panel)

After returning the liquid crystal panel produced in each case to the original liquid crystal TV, the front luminance of the liquid crystal TV during black display and white display in a dark room was measured using a color luminance meter (SR-UL1 manufactured by Topcon Techno House Co., Ltd.) ) was measured using Contrast was determined from (luminance during white display/luminance during black display). Table 1 also shows the contrast index (%) when the contrast in the case of using a pressure-sensitive adhesive layer having no dye (Comparative Example 1, Reference Comparative Example 1) is set to 100%.

(Measurement of reflectance of liquid crystal panel)

About the liquid crystal panel produced in each case, it measured by the method including regular reflection (SCI) with a D65 light source using the trade name "CM-2600d" made by Konica Minolta. The measurement temperature was 23°C. The average value of two repetitions was used as the measured value.

C: liquid crystal cell in IPS mode
A1: first optical functional layer
A2: Second optical functional layer
P1: 1st polarizing film
P2: Second polarizing film

Claims (7)

Liquid crystal cell in IPS mode,
A first optical functional layer and a first polarizing film sequentially disposed from the viewing side of the liquid crystal cell;
In the liquid crystal panel having a second optical functional layer and a second polarizing film sequentially disposed from the rear side of the liquid crystal cell,
The first optical function layer contains a colorant and has a haze in the range of 0.2 to 2%, and the second optical function layer does not contain a colorant.
The liquid crystal panel is characterized in that the liquid crystal panel does not contain a dye on the back side of the liquid crystal cell. According to claim 1,
A liquid crystal panel characterized in that the haze of the first optical function layer is in the range of 0.2 to 1.5%. delete According to claim 1,
The liquid crystal panel characterized in that the dye has a maximum absorption wavelength in at least one of a wavelength range of 470 to 510 nm and a wavelength range of 570 to 610 nm. According to claim 1,
A liquid crystal panel, characterized in that the dye is a tetraazaporphyrin-based dye. According to claim 1,
The liquid crystal panel characterized by containing 0.01 to 5 parts by weight of the pigment based on 100 parts by weight of a base polymer forming the resin layer of the first optical function layer. A liquid crystal display device characterized by using the liquid crystal panel according to any one of claims 1 to 2 and 4 to 6.

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