WO2019235064A1 - Liquid crystal display device - Google Patents

Abstract

This liquid crystal display device has a liquid crystal cell, has a liquid crystal panel having a first polarizing film positioned on the visible side of the liquid crystal cell and a second polarizing film positioned on the rear-surface side of the liquid crystal cell, and also has a backlighting unit, wherein the liquid crystal panel has a maximum absorption wavelength in the wavelength range of 570-610nm, the backlighting unit has a light emission spectrum peak intensity (Gp) in the wavelength range of 515-545nm and a light emission spectrum peak intensity (Rp) in the wavelength range of 605-650nm, and the Gp, the Rp, and the average value (Ave) of the light emission spectrum intensity in the wavelength range of 580-600nm satisfy formula (1). (1): Ave1≤0.3×{(Gp+Rp)/2}. This liquid crystal display device panel is capable of widening the color gamut and suppressing a decline in brightness.

Description

Liquid crystal display

The present invention relates to a liquid crystal display device. The liquid crystal display device can be applied to various uses.

In the liquid crystal display device, it is indispensable to dispose polarizing elements on both sides of the liquid crystal cell because of its image forming method, and generally a polarizing film is attached. When sticking the said polarizing film to a liquid crystal cell, an adhesive is normally used. Moreover, since adhesion | attachment of a polarizing film and a liquid crystal cell reduces the loss of light normally, each material is closely_contact | adhered using the adhesive. In such a case, the pressure-sensitive adhesive is a polarizing film with a pressure-sensitive adhesive layer provided in advance as a pressure-sensitive adhesive layer on one side of the polarizing film because it has the advantage of not requiring a drying step to fix the polarizing film. A film is generally used.

In recent years, brightness and vividness (that is, wide color gamut) have been demanded for image display devices, and organic EL display devices (OLEDs) have been attracting attention. Is required. For example, as a method for widening the color gamut of a liquid crystal display device, a polarizing film is provided on one or both sides of the liquid crystal cell via an adhesive layer containing a dye exhibiting an absorption maximum wavelength in a specific wavelength (560 to 610 nm) range. Lamination is proposed (Patent Documents 1 and 2).

JP 2011-039093 A JP 2014-092611 A

As described above, the pigment can be contained in the pressure-sensitive adhesive layer or in a film layer applied to the optical member. Thus, the optical function layer containing a pigment | dye can be formed by making a pigment | dye contain in a resin layer like a film layer or an adhesive layer. As in Patent Documents 1 and 2, a liquid crystal display device using a liquid crystal panel in which a polarizing film is bonded to a liquid crystal cell with an adhesive layer containing a dye can have a wide color gamut with the dye. However, since the optical function layer contains a dye, the dye in the optical function layer deteriorates with time from the viewpoint of moisture permeability of the resin layer serving as a base of the optical function layer, and the optical function layer Fades gradually. In particular, when the optical functional layer is a pressure-sensitive adhesive layer containing a dye, the liquid crystal display device has a reduced luminance because members forming the liquid crystal panel such as the pressure-sensitive adhesive layer contain the dye. It was.

An object of the present invention is to provide a liquid crystal display device that satisfies a wide color gamut and can suppress a decrease in luminance.

As a result of intensive studies to solve the above problems, the present inventors have found the following liquid crystal display device and have completed the present invention.

That is, the present invention relates to a liquid crystal cell, a liquid crystal panel having a first polarizing film disposed on the viewing side of the liquid crystal cell, a second polarizing film disposed on the back side of the liquid crystal cell, and a backlight unit. In a liquid crystal display device having
The liquid crystal panel has a maximum absorption wavelength in a wavelength range of 570 to 610 nm, and
The backlight unit is
Having a peak intensity (Gp) of an emission spectrum in a wavelength range of 515 to 545 nm,
Having a peak intensity (Rp) of an emission spectrum in a wavelength range of 605 to 650 nm, and
The average value (Ave1) of the emission spectrum intensity in the wavelength range of 580 to 600 nm and the Gp, Rp and the following formula (1)
Ave1 ≦ 0.3 × {(Gp + Rp) / 2} (1)
It is related with the liquid crystal display device characterized by satisfying.

In the liquid crystal display device, the liquid crystal panel includes a first optical functional layer disposed on the viewing side of the liquid crystal cell, and a second optical functional layer disposed on the back side of the liquid crystal cell, As at least one of the first optical functional layer and the second optical functional layer, one containing a dye having a maximum absorption wavelength in the wavelength region of 570 to 610 nm can be used.

In the liquid crystal display device, it is preferable that the transmittance of the maximum absorption wavelength of at least one of the first optical functional layer and the second optical functional layer is 50% or less.

In the liquid crystal display device, it is preferable that at least the first optical functional layer contains the dye.

In the liquid crystal display device, a tetraazaporphyrin-based dye can be used as the dye.

In the liquid crystal display device, it is preferable that the pigment is contained in an amount of 0.01 to 5 parts by weight with respect to 100 parts by weight of a solid material of the base material forming the resin layer of the optical function layer.

The present invention also provides a liquid crystal cell, a liquid crystal panel having a first polarizing film disposed on the viewing side of the liquid crystal cell, a second polarizing film disposed on the back side of the liquid crystal cell, and a backlight unit. In a liquid crystal display device having
The liquid crystal panel has a maximum absorption wavelength in a wavelength range of 470 to 510 nm, and
The backlight unit is
It has a peak intensity (Bp) of an emission spectrum in a wavelength range of 430 to 480 nm,
Having a peak intensity (Gp) of an emission spectrum in a wavelength range of 515 to 545 nm, and
The average value (Ave2) of the emission spectrum intensity in the wavelength range of 480 to 500 nm (Ave2) is the following formula (2)
Ave2 ≦ 0.15 × {(Bp + Gp) / 2} (2)
It is related with the liquid crystal display device characterized by satisfying.

In the liquid crystal display device, the liquid crystal panel includes a first optical functional layer disposed on the viewing side of the liquid crystal cell, and a second optical functional layer disposed on the back side of the liquid crystal cell, As at least one of the first optical functional layer and the second optical functional layer, one containing a dye having a maximum absorption wavelength in a wavelength region of 470 to 510 nm can be used.

In the liquid crystal display device, it is preferable that the transmittance of the maximum absorption wavelength of at least one of the first optical functional layer and the second optical functional layer is 50% or less.

In the liquid crystal display device, it is preferable that at least the first optical functional layer contains the dye.

In the liquid crystal display device, the dye may be at least one selected from tetraazaporphyrin dyes and cyanine dyes.

In the liquid crystal display device, it is preferable that the pigment is contained in an amount of 0.01 to 5 parts by weight with respect to 100 parts by weight of a solid material of the base material forming the resin layer of the optical function layer.

In the liquid crystal display device of the present invention, the liquid crystal panel has a maximum absorption wavelength in a predetermined wavelength range. As described above, by absorbing light of a part of wavelengths in the liquid crystal panel, the entire hue of the liquid crystal display device can be adjusted, and vividness can be improved by widening the color gamut. In particular, a dye having a maximum absorption wavelength in the wavelength range 470 to 510 nm and the wavelength range 570 to 610 nm emits light unnecessary for color expression in a wavelength range other than RGB (wavelength range 470 to 510 nm and / or wavelength range 570 to 610 nm). This can suppress the unnecessary light emission and is effective for widening the color gamut.

Further, the liquid crystal display device of the present invention is combined with a backlight unit whose emission spectrum in the predetermined wavelength range is controlled according to the liquid crystal panel having the maximum absorption wavelength in the predetermined wavelength range. That is, in a liquid crystal display device using a liquid crystal panel having a maximum absorption wavelength in a predetermined wavelength range, the decrease in luminance is observed in the wavelength range other than RGB (the portion where the colors are mixed) is absorbed by the liquid crystal panel. I thought it was because. In the present invention, each spectrum width of RG or each spectrum width of GB is narrow according to the liquid crystal panel having the maximum absorption wavelength in a wavelength region other than RGB, and within the wavelength region between RG or GB. By using a backlight unit with a low emission spectrum intensity, the LCD panel is designed so that there is less overlap between the wavelength range where the liquid crystal panel absorbs light and the wavelength range of the emission spectrum of the backlight. .

It is sectional drawing which shows one Embodiment of the liquid crystal display device of this invention. It is a graph which shows an example of the emission spectrum of the backlight unit of this invention.

Embodiments of the liquid crystal display device of the present invention will be described below with reference to the drawings. FIG. 1 is a cross-sectional view showing an embodiment of the liquid crystal display device of the present invention. In FIG. 1, a liquid crystal panel PN and a backlight unit BL are shown. The liquid crystal panel PN includes the liquid crystal cell C, the first polarizing film P1 disposed on the viewing side of the liquid crystal cell C, and the second disposed on the back side (backlight unit BL side) of the liquid crystal cell C. It has a polarizing film P2. In addition, the liquid crystal panel PN includes a first optical functional layer A1 disposed on the viewing side with respect to the liquid crystal cell C, and a second optical functional layer A2 disposed on the back side with respect to the liquid crystal cell C. it can. Arrangement relationship between the first optical functional layer A1 and the first polarizing film P1 on the viewing side of the liquid crystal cell C, and arrangement of the second optical functional layer A2 and the second polarizing film P2 on the back side of the liquid crystal cell C. The relationship is not particularly limited. In FIG. 1, as the liquid crystal panel PN, the first optical functional layer A1 and the first polarizing film P1 arranged in order from the liquid crystal cell C side to the viewing side, and from the liquid crystal cell C side to the back side. What has 2nd optical function layer A2 and 2nd polarizing film P2 which are arrange | positioned in order is illustrated.

For the liquid crystal panel of the present invention, a liquid crystal panel having a maximum absorption wavelength in a wavelength range of 570 to 610 nm or a wavelength range of 470 to 510 nm is used.

The provision of the maximum absorption wavelength in the above-mentioned wavelength range to the liquid crystal panel of the present invention can be adjusted by blending a dye with at least one of the members forming the liquid crystal panel. As a member which mix | blends a pigment | dye, it can carry out by mix | blending with a liquid crystal cell, a 1st polarizing film, a 2nd polarizing film, a 1st optical functional layer, and a 2nd optical functional layer which form a liquid crystal panel, for example. Moreover, the mixing | blending of the pigment | dye to a liquid crystal cell can be performed by mix | blending a pigment | dye with a color filter etc. Moreover, the pigment | dye of the 1st polarizing film and the 2nd polarizing film mix | blends a pigment | dye with the transparent protective film which forms the said polarizing film, its surface layer (hard-coat layer), an adhesive bond layer, an anchor layer, etc. Can be performed.

In the present invention, the blending of the pigment into the liquid crystal panel is performed on at least one of the first optical functional layer and the second optical functional layer to satisfy a wide color gamut and to reduce luminance. It is preferable from the viewpoint of restraining. In particular, the dye is preferably contained in at least the first optical functional layer.

<Optical function layer>
The first and second optical functional layers of the present invention are not particularly limited as long as they are resin layers containing a dye. Examples of the resin layer include a film layer and an adhesive layer. The first and second optical functional layers may have the same function or may be different. The first and second optical functional layers can be formed from a composition containing a base polymer and a pigment.

In the first and second optical functional layers having the dye, the transmittance of the maximum absorption wavelength in the wavelength region 570 to 610 nm or the wavelength region 470 to 510 nm is preferably 50% or less from the viewpoint of expanding the color gamut. Is preferably 30% or less, and more preferably 20% or less.

<Dye>
Various dyes can be used as the dye contained in the optical functional layer. Examples of the dye include various compounds such as tetraazaporphyrin, porphyrin, cyanine, squaraine, azo, pyromethene, squarylium, xanthene, and oxonol. From the viewpoint of widening the color gamut, the dye is preferably a tetraazaporphyrin dye, porphyrin dye, cyanine dye, squalium dye, or squaraine dye, and particularly preferably a tetraazaporphyrin dye or cyanine dye. Specifically, the dye is disclosed in JP 2011-116818 A. Only 1 type may be used for the said pigment | dye and it can also use 2 or more types together.

As the dye, one having a maximum absorption wavelength in a wavelength range of 570 to 610 nm or a wavelength range of 470 to 510 nm is used. In addition, a dye having a maximum absorption wavelength in a wavelength range of 570 to 610 nm and a wavelength range of 470 to 510 nm can be used. The dye having the maximum absorption wavelength in the wavelength range can absorb light emission unnecessary for color expression and suppress the light emission, and is effective for widening the color range. As a dye having a maximum absorption wavelength in the wavelength range, a tetraazaporphyrin-based dye can be suitably used. For example, as a dye exhibiting the maximum absorption wavelength in the wavelength range of 570 to 610 nm, tetraazaporphyrin compounds (trade names: PD-320, PD311) manufactured by Yamamoto Kasei Co., Ltd., tetraazaporphyrin compounds manufactured by Yamada Chemical Industries ( Product name: FDG-007) and the like. The maximum absorption wavelength of the dye was measured with a spectrophotometer (V-570 manufactured by JASCO Corporation). Examples of the dye having a maximum absorption wavelength in the wavelength range of 470 to 510 nm include tetraazaporphyrin compounds (compounds described in Japanese Patent No. 5015644) manufactured by Yamamoto Kasei Co., Ltd., and cyanine compounds manufactured by Yamada Chemical Co., Ltd. ( Product name: FDB-007).

The blending amount of the dye can be appropriately set depending on the member to be applied, the absorption wavelength range of the dye, and the extinction coefficient. However, the solid weight of the base material of the member is 100 parts by weight (hereinafter, the same standard). The amount is preferably 0.01 to 5 parts by weight, more preferably 0.05 to 3 parts by weight, and still more preferably 0.1 to 1 part by weight. When the pigment is blended in the pressure-sensitive adhesive layer, the content of the pigment is 0.01 to 5 parts by weight with respect to 100 parts by weight of the solid weight of the base polymer in the pressure-sensitive adhesive composition forming the pressure-sensitive adhesive layer. Preferably there is. In particular, the above range is preferable when a tetraazaporphyrin dye or a cyanine dye is used.

Hereinafter, each member of the liquid crystal panel of the present invention will be described.

<Liquid crystal cell>
As the liquid crystal cell C (glass substrate / liquid crystal layer / glass substrate configuration), liquid crystal cells of various modes can be used. As the liquid crystal layer of the liquid crystal cell C, a liquid crystal layer containing liquid crystal molecules that are homogeneously aligned in the absence of an electric field can be used. Nematic liquid crystals are preferably used as the liquid crystal molecules. For example, liquid crystal cells such as IPS mode, TN mode, STN mode, and VA mode can be used.

The liquid crystal cell C has a configuration in which the liquid crystal layer is sandwiched between two transparent substrates. Inside or outside of the liquid crystal cell, a liquid crystal panel with a built-in touch sensing function can be used. A color filter substrate can be provided on the liquid crystal cell (transparent substrate on the viewing side). Examples of the material for forming the transparent substrate include glass and polymer films.

<Adhesive layer>
Examples of the optical functional layer of the present invention include a pressure-sensitive adhesive layer containing a dye, and the pressure-sensitive adhesive layer can be formed from a pressure-sensitive adhesive composition containing a pressure-sensitive base polymer and a dye. Although there is no restriction | limiting in particular about the kind of adhesive base polymer, For example, rubber-type polymer, (meth) acrylic-type polymer, silicone-type polymer, urethane-type polymer, vinyl alkyl ether-type polymer, polyvinyl alcohol-type polymer, polyvinylpyrrolidone type Various polymers, such as a polymer, a polyacrylamide type polymer, a cellulose type polymer, are mentioned.

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

Among these sticky base polymers, those having excellent optical transparency, suitable wettability, cohesiveness, and adhesive pressure characteristics, and excellent weather resistance and heat resistance are preferably used. A (meth) acrylic polymer is preferably used as such a feature. Hereinafter, an acrylic pressure-sensitive adhesive using a (meth) acrylic polymer containing alkyl (meth) acrylate as a monomer unit as a base polymer as 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. (Meth) acrylate refers to acrylate and / or methacrylate, and (meth) of the present invention has the same meaning.

Examples of the alkyl (meth) acrylate that constitutes the main skeleton of the (meth) acrylic polymer include linear or branched alkyl groups having 1 to 18 carbon atoms. These can be used alone or in combination. These alkyl groups preferably have an average carbon number of 3 to 9.

Also, alkyl (meth) acrylates containing aromatic rings such as phenoxyethyl (meth) acrylate and benzyl (meth) acrylate are used from the viewpoints of adhesive properties, durability, retardation adjustment, refractive index adjustment, and the like. be able to.

In the (meth) acrylic polymer, one or more having a polymerizable functional group having an unsaturated double bond such as a (meth) acryloyl group or a vinyl group for the purpose of improving adhesiveness and heat resistance These copolymerizable monomers can be introduced by copolymerization. Specific examples of such copolymerized monomers include, for example, 2-hydroxyethyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, (meth) acrylic acid 6 Hydroxyl-containing monomers such as hydroxyhexyl, 8-hydroxyoctyl (meth) acrylate, 10-hydroxydecyl (meth) acrylate, 12-hydroxylauryl (meth) acrylate and (4-hydroxymethylcyclohexyl) -methyl acrylate 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 anhydrides such as maleic anhydride and itaconic anhydride Monomer-containing monomer with acrylic acid caprolactone Sulfuric acids such as styrene sulfonic acid, allyl sulfonic acid, 2- (meth) acrylamide-2-methylpropane sulfonic acid, (meth) acrylamide propane sulfonic acid, sulfopropyl (meth) acrylate, (meth) acryloyloxynaphthalene sulfonic acid Acid group-containing monomers: Phosphoric acid group-containing monomers such as 2-hydroxyethylacryloyl phosphate.

Also, (N-substituted) amides such as (meth) acrylamide, N, N-dimethyl (meth) acrylamide, N-butyl (meth) acrylamide, N-methylol (meth) acrylamide, N-methylolpropane (meth) acrylamide, etc. Monomer; (meth) acrylic acid aminoethyl, (meth) acrylic acid N, N-dimethylaminoethyl, (meth) acrylic acid t-butylaminoethyl, etc. (meth) acrylic alkylaminoalkyl monomers; (meth) acrylic (Meth) acrylic acid alkoxyalkyl monomers such as methoxyethyl acid and ethoxyethyl (meth) acrylate; N- (meth) acryloyloxymethylenesuccinimide, N- (meth) acryloyl-6-oxyhexamethylenesuccinimide, N- ( (Meta) acryloyl-8- Succinimide monomers such as xoxyoctamethylene succinimide and N-acryloylmorpholine; maleimide monomers such as N-cyclohexylmaleimide, N-isopropylmaleimide, N-laurylmaleimide and N-phenylmaleimide; N-methylitaconimide, N-ethylitacon Examples of monomers for modification include itaconimide monomers such as imide, N-butyl itaconimide, N-octyl itaconimide, N-2-ethylhexylitaconimide, N-cyclohexyl leuconconimide, N-lauryl itaconimide, and the like. .

Further modifying monomers include vinyl acetate, vinyl propionate, N-vinyl pyrrolidone, methyl vinyl pyrrolidone, vinyl pyridine, vinyl piperidone, vinyl pyrimidine, vinyl piperazine, vinyl pyrazine, vinyl pyrrole, vinyl imidazole, vinyl oxazole, vinyl morpholine, N- Vinyl monomers such as vinylcarboxylic acid amides, styrene, α-methylstyrene, N-vinylcaprolactam; cyanoacrylate monomers such as acrylonitrile and methacrylonitrile; epoxy group-containing acrylic monomers such as glycidyl (meth) acrylate; (Meth) acrylic acid polyethylene glycol, (meth) acrylic acid polypropylene glycol, (meth) acrylic acid methoxyethylene glycol, (meth) acrylic acid methoxy Glycol acrylic ester monomers such as propylene glycol; acrylic ester monomers such as tetrahydrofurfuryl (meth) acrylate, fluorine (meth) acrylate, silicone (meth) acrylate and 2-methoxyethyl acrylate may also be used. it can. Furthermore, isoprene, butadiene, isobutylene, vinyl ether and the like can be mentioned.

Furthermore, examples of copolymerizable monomers other than the above include silane-based monomers containing silicon atoms. Examples of the silane monomer include 3-acryloxypropyltriethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, 4-vinylbutyltrimethoxysilane, 4-vinylbutyltriethoxysilane, and 8-vinyloctyltrimethoxysilane. , 8-vinyloctyltriethoxysilane, 10-methacryloyloxydecyltrimethoxysilane, 10-acryloyloxydecyltrimethoxysilane, 10-methacryloyloxydecyltriethoxysilane, 10-acryloyloxydecyltriethoxysilane, and the like.

Examples of copolymer monomers include tripropylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, bisphenol A diglycidyl ether di (meth) acrylate, neo Pentyl glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate (Meth) acryloyl such as esterified product of (meth) acrylic acid and polyhydric alcohol such as caprolactone-modified dipentaerythritol hexa (meth) acrylate Groups such as polyfunctional monomers having 2 or more unsaturated double bonds such as vinyl groups, vinyl groups and the like, and functional groups similar to the monomer components on the backbone of polyester, epoxy, urethane, etc. (meth) acryloyl groups, vinyl groups, etc. Polyester (meth) acrylate, epoxy (meth) acrylate, urethane (meth) acrylate, or the like to which two or more saturated double bonds have been added can also be used.

The (meth) acrylic polymer has an alkyl (meth) acrylate as a main component in the weight ratio of all constituent monomers, and the ratio of the copolymerizable monomer in the (meth) acrylic polymer is not particularly limited. The ratio of the polymerization monomer 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 the constituent monomers.

Among these copolymer monomers, hydroxyl group-containing monomers and carboxyl group-containing monomers are preferably used from the viewpoint of adhesion and durability. A hydroxyl group-containing monomer and a carboxyl group-containing monomer can be used in combination. These copolymerization monomers serve as reaction points with the crosslinking agent when the pressure-sensitive adhesive composition contains a crosslinking agent. Since a hydroxyl group-containing monomer, a carboxyl group-containing monomer, and the like are rich in reactivity with an intermolecular crosslinking agent, they are preferably used for improving the cohesiveness and heat resistance of the resulting pressure-sensitive adhesive layer. A hydroxyl group-containing monomer is preferable from the viewpoint of reworkability, and a carboxyl group-containing monomer is preferable from the viewpoint of achieving both durability and reworkability.

When the copolymerization monomer contains a hydroxyl group-containing monomer, the proportion is preferably 0.01 to 15% by weight, more preferably 0.03 to 10% by weight, and even more preferably 0.05 to 7% by weight. preferable. When the copolymerization monomer contains a carboxyl group-containing monomer, the proportion thereof is preferably 0.05 to 10% by weight, more preferably 0.1 to 8% by weight, and further preferably 0.2 to 6% by weight. preferable.

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. In view of durability, particularly heat resistance, it is preferable to use those having a weight average molecular weight of 700,000 to 2,700,000. Further, it is preferably 800,000 to 2.5 million. A weight average molecular weight of less than 500,000 is not preferable in terms of heat resistance. On the other hand, if the weight average molecular weight is more than 3 million, a large amount of dilution solvent is required to adjust the viscosity for coating, which is not preferable. The weight average molecular weight is a value measured by GPC (gel permeation chromatography) and calculated in terms of polystyrene.

For the 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. Further, the (meth) acrylic polymer obtained may be any of a random copolymer, a block copolymer, a graft copolymer, and the like.

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

The polymerization initiator, chain transfer agent, emulsifier and the like used for radical polymerization are not particularly limited and can be appropriately selected and used. In addition, the weight average molecular weight of a (meth) acrylic-type polymer can be controlled by the usage-amount of a polymerization initiator and a chain transfer agent, and reaction conditions, The usage-amount is suitably adjusted according to these kinds.

Examples of the radical polymerization initiator include 2,2′-azobisisobutyronitrile, 2,2′-azobis (2-amidinopropane) dihydrochloride, 2,2′-azobis [2- (5-methyl- 2-imidazolin-2-yl) propane] dihydrochloride, 2,2'-azobis (2-methylpropionamidine) disulfate, 2,2'-azobis (N, N'-dimethyleneisobutylamidine), 2, Azo initiators such as 2'-azobis [N- (2-carboxyethyl) -2-methylpropionamidine] hydrate (VA-057 manufactured by Wako Pure Chemical Industries, Ltd.), persulfates such as potassium persulfate and ammonium persulfate Salt, di (2-ethylhexyl) peroxydicarbonate, di (4-tert-butylcyclohexyl) peroxydicarbonate, di-se -Butylperoxydicarbonate, t-butylperoxyneodecanoate, t-hexylperoxypivalate, t-butylperoxypivalate, dilauroyl peroxide, di-n-octanoyl peroxide, 1,1 , 3,3-tetramethylbutylperoxy-2-ethylhexanoate, di (4-methylbenzoyl) peroxide, dibenzoyl peroxide, t-butylperoxyisobutyrate, 1,1-di (t-hexyl) Peroxy) Peroxides such as cyclohexane, t-butyl hydroperoxide, hydrogen peroxide, peroxides and combinations such as combinations of persulfate and sodium bisulfite, combinations of peroxide and sodium ascorbate The redox initiator combined with the agent can be mentioned, The present invention is not limited to these.

The radical polymerization initiator may be used alone or in combination of two or more, but the total content is 0.005 to 1 weight with respect to 100 parts by weight of the monomer. Part is preferable, and about 0.02 to 0.5 part by weight is more preferable.

Examples of the chain transfer agent include lauryl mercaptan, glycidyl mercaptan, mercaptoacetic acid, 2-mercaptoethanol, thioglycolic acid, 2-ethylhexyl thioglycolate, and 2,3-dimercapto-1-propanol. The chain transfer agent may be used alone or in combination of two or more, but the total content is 0.1 parts by weight with respect to 100 parts by weight of the total amount of monomer components. Less than or equal to

Examples of the emulsifier used in emulsion polymerization include anionic emulsifiers such as sodium lauryl sulfate, ammonium lauryl sulfate, sodium dodecylbenzenesulfonate, ammonium polyoxyethylene alkyl ether sulfate, sodium polyoxyethylene alkyl phenyl ether sulfate, and polyoxy Nonionic emulsifiers such as ethylene alkyl ether, polyoxyethylene alkyl phenyl ether, polyoxyethylene fatty acid ester, polyoxyethylene-polyoxypropylene block polymer and the like can be mentioned. These emulsifiers may be used alone or in combination of two or more.

Furthermore, as reactive emulsifiers, emulsifiers into which radical polymerizable functional groups such as propenyl groups and allyl ether groups are introduced, specifically, for example, Aqualon HS-10, HS-20, KH-10, BC-05 BC-10, BC-20 (all of which are manufactured by Daiichi Kogyo Seiyaku Co., Ltd.), Adekaria Soap SE10N (manufactured by Asahi Denka Kogyo Co., Ltd.) Reactive emulsifiers are preferable because they are incorporated into the polymer chain after polymerization and thus have improved water resistance. The amount of the emulsifier used is preferably 0.3 to 5 parts by weight with respect to 100 parts by weight of the total amount of monomer components, and more preferably 0.5 to 1 part by weight from the viewpoint of polymerization stability and mechanical stability.

<Crosslinking agent>
Furthermore, in this invention, a crosslinking agent can be contained in the adhesive composition which forms an adhesive layer. 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. A polyfunctional metal chelate is one in which a polyvalent metal is covalently or coordinately bonded to an organic compound. Examples of 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. Can be mentioned. Examples of the atom in the organic compound that is covalently bonded or coordinated 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.

Examples of the compound relating to the isocyanate-based crosslinking agent include isocyanate monomers such as tolylene diisocyanate, chlorophenylene diisocyanate, tetramethylene diisocyanate, xylylene diisocyanate, diphenylmethane diisocyanate, hydrogenated diphenylmethane diisocyanate, and these isocyanate monomers. Examples include isocyanate compounds added with trimethylolpropane, isocyanurates, burette compounds, and urethane prepolymer isocyanates such as polyether polyols, polyester polyols, acrylic polyols, polybutadiene polyols, and polyisoprene polyols. be able to. Particularly preferred is a polyisocyanate compound, which is one or a polyisocyanate compound derived from one selected from the group consisting of hexamethylene diisocyanate, hydrogenated xylylene diisocyanate, and isophorone diisocyanate. Here, hexamethylene diisocyanate, hydrogenated xylylene diisocyanate, isophorone diisocyanate, polyol-modified is selected from the group consisting of hexamethylene diisocyanate, hydrogenated xylylene diisocyanate, and isophorone diisocyanate or a polyisocyanate compound derived therefrom. Examples include hexamethylene diisocyanate, polyol-modified hydrogenated xylylene diisocyanate, trimer-type hydrogenated xylylene diisocyanate, and polyol-modified isophorone diisocyanate. The exemplified polyisocyanate compound is preferable because the reaction with a hydroxyl group proceeds rapidly, particularly using an acid or base contained in the polymer as a catalyst, and thus contributes to the speed of crosslinking.

As the peroxide, any radical active species can be used as long as it generates radical active species by heating or light irradiation to advance the crosslinking of the base polymer of the pressure-sensitive adhesive composition. However, in consideration of workability and stability. It is preferable to use a peroxide having a one-minute half-life temperature of 80 ° C. to 160 ° C., more preferably a peroxide having a 90 ° C. to 140 ° C.

Examples of the peroxide include di (4-t-butylcyclohexyl) peroxydicarbonate (1 minute half-life temperature: 92.1 ° C.), di-sec-butyl peroxydicarbonate (1 minute half-life temperature). : 92.4 ° C.), t-butyl peroxyneodecanoate (1 minute half-life temperature: 103.5 ° C.), t-hexyl peroxypivalate (1 minute half-life temperature: 109.1 ° C.), t -Butylperoxypivalate (1 minute half-life temperature: 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 (1 minute half-life temperature: 124.3 ° C.), di (4-methylbenzoyl) -Oxide (1 minute half-life temperature: 128.2 ° C), dibenzoyl peroxide (1 minute half-life temperature: 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, since the crosslinking reaction efficiency is particularly excellent, di (4-t-butylcyclohexyl) peroxydicarbonate (1 minute half-life temperature: 92.1 ° C.), dilauroyl peroxide (1 minute half-life temperature: 116. 4 ° C.), dibenzoyl peroxide (1 minute half-life temperature: 130.0 ° C.) and the like are preferably used.

The peroxide half-life is an index representing the decomposition rate of the peroxide, and means the time until the remaining amount of peroxide is reduced to 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 a manufacturer catalog, for example, “Organic peroxide catalog 9th edition of Nippon Oil & Fats Co., Ltd.” (May 2003) ".

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

Furthermore, the pressure-sensitive adhesive composition forming the pressure-sensitive adhesive layer having the pigment of the present invention can contain a silane coupling agent. The durability can be improved by using a silane coupling agent. Specific examples of the silane coupling agent include 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-triethoxysilyl- Amino group-containing silane coupling agents such as N- (1,3-dimethylbutylidene) propylamine, N-phenyl-γ-aminopropyltrimethoxysilane, 3-acryloxypropyltrimethoxysilane, 3-methacryloxypropyltri (Meth) a, such as ethoxysilane Lil group-containing silane coupling agents, such as isocyanate group-containing silane coupling agents such as 3-isocyanate propyl triethoxysilane and the like.

The silane coupling agent may be used alone or in combination of two or more, but the total content is 100 parts by weight of a base polymer such as the (meth) acrylic polymer. On the other hand, the silane coupling agent is preferably 0.001 to 5 parts by weight, more preferably 0.01 to 1 part by weight, further preferably 0.02 to 1 part by weight, and further 0.05 to 0. .6 parts by weight is preferred. This is an amount that improves the durability and appropriately maintains the adhesive force to an optical member such as a liquid crystal cell.

Furthermore, in the present invention, polyether-modified silicone can be blended in the pressure-sensitive adhesive composition forming the pressure-sensitive adhesive layer having a pigment. As the polyether-modified silicone, for example, those disclosed in JP 2010-275522 A can be used.

Further, in the present invention, the pressure-sensitive adhesive composition for forming the pressure-sensitive adhesive layer having a pigment may contain other known additives, such as powders such as colorants and pigments, dyes, and surface active agents. Agent, plasticizer, tackifier, surface lubricant, leveling agent, softener, anti-aging agent, antioxidant, light stabilizer, UV absorber, polymerization inhibitor, inorganic or organic filler, metal powder, It can be added as appropriate depending on the application in which particles, foils, etc. are used. Moreover, you may employ | adopt the redox system which added a reducing agent within the controllable range.

The pressure-sensitive adhesive composition forms a pressure-sensitive adhesive layer having a pigment. In forming the pressure-sensitive adhesive layer, the addition amount of the crosslinking agent is adjusted, and the influence of the crosslinking treatment temperature and the crosslinking treatment time is fully considered. It is preferable.

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

Further, such 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 for forming a pressure-sensitive adhesive layer having a dye, for example, the pressure-sensitive adhesive composition is applied to a release-treated separator, and a polymerization solvent is dried and removed to form a pressure-sensitive adhesive layer, which is then transferred to a polarizing film. It is produced by a method, or a method of applying the pressure-sensitive adhesive composition to a polarizing film and drying and removing the polymerization solvent to form a pressure-sensitive adhesive layer on the polarizing film. In applying the pressure-sensitive adhesive, one or more solvents other than the polymerization solvent may be added as appropriate.

A silicone release liner is preferably used as the release-treated separator. In the step of applying the adhesive composition of the present invention on such a liner and drying to form a pressure-sensitive adhesive layer, a method for drying the pressure-sensitive adhesive is appropriately employed depending on the purpose. obtain. Preferably, a method of heating and drying 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, an adhesive having excellent adhesive properties can be obtained.

Appropriate time can be adopted as the drying time. 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.

Also, the pressure-sensitive adhesive layer can be formed after forming an anchor layer on the surface of the polarizing film or performing various easy adhesion treatments such as corona treatment and plasma treatment. Moreover, you may perform an easily bonding process on the surface of an adhesive layer.

As the method for forming the pressure-sensitive adhesive layer, various methods are used. 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. Examples thereof include an extrusion coating method.

The thickness of the pressure-sensitive adhesive layer is not particularly limited and is, for example, about 1 to 100 μm. The thickness is preferably 2 to 50 μm, more preferably 2 to 40 μm, and still more preferably 5 to 35 μm.

<Film layer>
The optical functional layer of the present invention includes a film layer containing a dye, and the film layer can be formed from a composition containing a base polymer for film formation and a dye. Examples of the material of the base polymer that forms the film layer include the same materials as those constituting the transparent protective film described later. In particular, as the material, cellulose resin such as triacetyl cellulose, polyester resin, (meth) acrylic resin, cyclic polyolefin resin (norbornene resin) and the like are preferably used. A film layer can be applied to a 1st polarizing film and a 2nd polarizing film using an adhesive agent, an adhesive, etc. suitably.

Various methods can be employed for forming the film layer containing the pigment. For example, when the pellets of the resin material are dissolved in a solvent, a film layer can be produced by preparing a composition by mixing a dye and casting or extruding the composition. In that case, a film layer can be shape | molded by appropriate thickness. In preparing the composition, additives can be appropriately blended.

The thickness of the film layer is not particularly limited, and is the same as that of the pressure-sensitive adhesive layer, for example, about 1 to 100 μm. The thickness is preferably 2 to 50 μm, more preferably 2 to 40 μm, and still more preferably 5 to 35 μm.

When the optical functional layer (particularly the pressure-sensitive adhesive layer) is exposed, the optical functional layer (particularly the pressure-sensitive adhesive layer) may be protected with a sheet (separator) that has been subjected to a release treatment until practical use.

Examples of the constituent material of the separator include, for example, 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 an appropriate thin leaf body etc. can be mentioned, a plastic film is used suitably from the point which is excellent in surface smoothness.

The plastic film is not particularly limited as long as it can protect the optical functional layer (particularly, the pressure-sensitive adhesive layer). For example, a polyvinyl alcohol film, a polyethylene film, a polypropylene film, a polybutene film, a polybutadiene film, a polymethyl film Examples thereof include pentene film, polyvinyl chloride film, vinyl chloride copolymer film, polyethylene terephthalate film, polybutylene terephthalate film, polyurethane film, and ethylene-vinyl acetate copolymer film.

The thickness of the separator is usually about 5 to 200 μm, preferably about 5 to 100 μm. For the separator, if necessary, mold release and antifouling treatment with a silicone type, fluorine type, long chain alkyl type or fatty acid amide type release agent, silica powder, etc., coating type, kneading type, vapor deposition type It is also possible to carry out antistatic treatment such as. In particular, when the surface of the separator is appropriately subjected to release treatment such as silicone treatment, long-chain alkyl treatment, and fluorine treatment, the peelability from the optical functional layer (particularly the pressure-sensitive adhesive layer) can be further improved.

The optical functional layer is applied to a liquid crystal cell to form a liquid crystal panel. When the optical functional layer is a pressure-sensitive adhesive layer, the pressure-sensitive adhesive layer is previously applied to the polarizing film when bonded to the liquid crystal cell. Can be used as a polarizing film with an adhesive layer. The release-treated sheet used in the production of the polarizing film with the pressure-sensitive adhesive layer can be used as a separator for the polarizing film with the pressure-sensitive adhesive layer as it is, and the process can be simplified.

<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 can be used. Examples of polarizers include dichroic iodine and dichroic dyes on hydrophilic polymer films such as polyvinyl alcohol films, partially formalized polyvinyl alcohol films, and ethylene / vinyl acetate copolymer partially saponified films. Examples thereof include polyene-based oriented films such as those obtained by adsorbing substances and uniaxially stretched, polyvinyl alcohol dehydrated products and polyvinyl chloride dehydrochlorinated products. Among these, a polarizer composed of a polyvinyl alcohol film and a dichroic substance such as iodine is preferable. The thickness of these polarizers is not particularly limited, but is generally about 80 μm or less.

A polarizer obtained by dyeing a polyvinyl alcohol film with iodine and uniaxially stretching it can be prepared, for example, by dyeing a polyvinyl alcohol film in an aqueous solution of iodine and stretching it 3 to 7 times the original length. it can. If necessary, it can be immersed in an aqueous solution of potassium iodide or the like which may contain boric acid, zinc sulfate, zinc chloride or the like. Further, if necessary, the polyvinyl alcohol film may be immersed in water and washed before dyeing. In addition to washing the polyvinyl alcohol film surface with stains and antiblocking agents by washing the polyvinyl alcohol film with water, the polyvinyl alcohol film is also swollen to prevent unevenness such as uneven coloring. is there. Stretching may be performed after dyeing with iodine, may be performed while dyeing, or may be dyed with iodine after stretching. The film can be stretched even in an aqueous solution of boric acid or potassium iodide or in a water bath.

As the polarizer, a thin polarizer having a thickness of 10 μm or less can be used. From the viewpoint of thinning, the thickness is preferably 1 to 7 μm. Such a thin polarizer is preferable in that the thickness unevenness is small, the visibility is excellent, the dimensional change is small, the durability is excellent, and the thickness of the polarizing film can be reduced.

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

As the thin polarizing film, among the production methods including the step of stretching in the state of a laminate and the step of dyeing, WO2010 / 100917 pamphlet, PCT / PCT / PCT / JP 2010/001460 specification, or Japanese Patent Application No. 2010-269002 and Japanese Patent Application No. 2010-263692, the one obtained by a production method including a step of stretching in a boric acid aqueous solution is preferable. What is obtained by the manufacturing method including the process of extending | stretching in the air auxiliary before extending | stretching in the boric acid aqueous solution as described in Japanese Patent Application No. 2010-269002 and Japanese Patent Application No. 2010-263692 is preferable.

As a material constituting the transparent protective film, 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 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, cyclic Examples thereof include polyolefin resins (norbornene resins), polyarylate resins, polystyrene resins, polyvinyl alcohol resins, and mixtures thereof. A transparent protective film is bonded to one side of the polarizer with an adhesive layer. On the other side, a (meth) acrylic, urethane-based, acrylurethane-based, epoxy-based, silicone is used as a transparent protective film. A thermosetting resin such as a system or an ultraviolet curable resin can be used. One or more kinds of arbitrary appropriate additives may be contained in the transparent protective film. Examples of the additive include an ultraviolet absorber, an antioxidant, a lubricant, a plasticizer, a mold release agent, an anti-coloring agent, a flame retardant, a nucleating agent, an antistatic agent, a pigment, and a coloring agent. 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, and particularly preferably 70 to 97% by weight. . When content of the said thermoplastic resin in a transparent protective film is 50 weight% or less, there exists a possibility that the high transparency etc. which a thermoplastic resin originally has cannot fully be expressed.

The thickness of the transparent protective film is not particularly limited and is, for example, about 10 to 90 μm. The thickness is preferably 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 can be provided on the surface of the transparent protective film to which the polarizer is not adhered.

The adhesive used for laminating the polarizer and the transparent protective film is not particularly limited as long as it is optically transparent, and water-based, solvent-based, hot-melt-based, radical curable, and cationic curable types are used. However, water-based adhesives or radical curable adhesives are suitable.

<LCD panel>
As described above, the liquid crystal panel of the present invention is disposed, for example, on the back side of the liquid crystal cell, the first optical functional layer and the first polarizing film disposed on the viewing side of the liquid crystal cell, and the liquid crystal cell. A second optical functional layer and a second polarizing film. In addition to the polarizing film, other optical layers can be applied for forming the liquid crystal panel. The optical layer is not particularly limited. For example, a reflection plate, a semi-transmission plate, a retardation plate (including wavelength plates such as 1/2 and 1/4), a viewing angle compensation film, a brightness enhancement film, and the like of a liquid crystal panel. One or two or more optical layers that may be used for formation can be used on the viewing side and / or the back side of the liquid crystal cell.

<Liquid crystal display device>
In the liquid crystal display device, a predetermined backlight unit is combined in accordance with a predetermined maximum absorption wavelength of the liquid crystal panel. The backlight unit can be prepared by combining light sources so as to satisfy the following characteristics.

When using a liquid crystal panel having a maximum absorption wavelength in the wavelength range of 570 to 610 nm,
As the backlight unit,
Having a peak intensity (Gp) of an emission spectrum in a wavelength range of 515 to 545 nm,
Having a peak intensity (Rp) of an emission spectrum in a wavelength range of 605 to 650 nm, and
The average value (Ave1) of the emission spectrum intensity in the wavelength range of 580 to 600 nm and the Gp, Rp and the following formula (1)
Ave1 ≦ 0.3 × {(Gp + Rp) / 2} (1)
Those satisfying the above are used.

In addition, when using a liquid crystal panel having a maximum absorption wavelength in the wavelength range of 470 to 510 nm,
As the backlight unit,
It has a peak intensity (Bp) of an emission spectrum in a wavelength range of 430 to 480 nm,
Having a peak intensity (Gp) of an emission spectrum in a wavelength range of 515 to 545 nm, and
The average value (Ave2) of the emission spectrum intensity in the wavelength range of 480 to 500 nm (Ave2) is the following formula (2)
Ave2 ≦ 0.15 × {(Bp + Gp) / 2} (2)
Those satisfying the above are used.

In addition, the wavelength range 570 to 610 nm or the wavelength range 470 to 510 nm related to the maximum absorption wavelength in the liquid crystal panel, and the wavelength range 580 to 600 nm related to the calculation of Ave1 included in the backlight, or the wavelength range 480 to 500 nm related to the calculation of Ave1. Although there is a difference, it has been found that the luminance reduction inhibiting effect in the present invention can be obtained when the wavelength range related to the maximum absorption wavelength related to the liquid crystal panel is wider than the wavelength range related to the backlight.

FIG. 2 is a graph showing an example of an emission spectrum of the backlight unit. FIG. 2 shows the peak intensity (Bp), peak intensity (Gp), and peak intensity (Rp) in each wavelength region. In FIG. 2, Ave1 (average value of emission spectrum intensity) in w1 (wavelength range 580 to 600 nm) and Ave2 (average value of emission spectrum intensity) in w2 (wavelength range 480 to 500 nm) are conceptually shown. Show.

Having a peak intensity (Gp) in the wavelength range indicates that the wavelength range of the G spectrum is narrow, and having a peak intensity (Rp) in the wavelength range indicates that the wavelength range of the R spectrum is narrow. It shows that the emission spectrum intensity in the wavelength region between the spectrum and the R spectrum (portion where colors are mixed) becomes relatively small. Further, satisfying the above formula (1): Ave1 ≦ 0.3 × {(Gp + Rp) / 2} means that the liquid crystal panel is between the G spectrum and the R spectrum that correspond to the maximum absorption wavelength in the wavelength range of 570 to 610 nm. This indicates that the emission spectrum intensity in the wavelength region (the portion where the colors are mixed) is absolutely small. As described above, in the liquid crystal display device of the present invention, in the wavelength range other than RGB (color-mixed portion), the overlap between the wavelength range where the liquid crystal panel absorbs light and the wavelength range of the emission spectrum of the backlight is reduced. Therefore, it is possible to suppress a decrease in luminance while satisfying a wide color gamut.

In the above formula (1), the coefficient “0.3” is preferably 0.25, and more preferably 0.2 in view of the above design.

Having the peak intensity (Bp) in the wavelength range indicates that the wavelength range of the B spectrum is narrow, and having the peak intensity (Gp) in the wavelength range indicates that the wavelength range of the G spectrum is narrow. It shows that the emission spectrum in the wavelength region between the spectrum and the G spectrum (portion where colors are mixed) becomes relatively small. Further, satisfying the above formula (2): Ave2 ≦ 0.15 × {(Bp + Gp) / 2} means that the B spectrum and G corresponding to the liquid crystal panel having a maximum absorption wavelength in the wavelength range of 470 to 510 nm. It shows that the emission spectrum in the wavelength region between the spectra (the part where the colors are mixed) is absolutely small. As described above, in the liquid crystal display device of the present invention, in the wavelength range other than RGB (color-mixed portion), the overlap between the wavelength range where the liquid crystal panel absorbs light and the wavelength range of the emission spectrum of the backlight is reduced. Therefore, it is possible to suppress a decrease in luminance while satisfying a wide color gamut.

The coefficient “0.15” in the formula (2) is preferably 0.13, and more preferably 0.1.

The liquid crystal display device of the present invention uses a liquid crystal panel having a maximum absorption wavelength in a wavelength range of 570 to 610 nm and a wavelength range of 470 to 510 nm, and satisfies the above formulas (1) and (2). A backlight unit can be used.

The liquid crystal display device of the present invention is formed by appropriately assembling a backlight unit and incorporating a drive circuit into the liquid crystal panel. Furthermore, when forming a liquid crystal display device, for example, one or more layers of appropriate parts such as a diffusion plate, an antiglare layer, an antireflection film, a protective plate, a prism array, a lens array sheet, and a light diffusion plate are placed at appropriate positions. Can be arranged. In addition, a reflector or the like can be used.

Hereinafter, the present invention will be specifically described by way of examples, but the present invention is not limited to these examples. In addition, all the parts and% in each example are based on weight. The room temperature standing conditions not specifically defined 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 GPC (gel permeation chromatography). It measured similarly about Mw / Mn.
・ Analyzer: manufactured by Tosoh Corporation, HLC-8120GPC
Column: manufactured by Tosoh Corporation, G7000H _XL + GMH _XL + GMH _XL
・ Column size: 7.8mmφ × 30cm each 90cm in total
-Column temperature: 40 ° C
・ Flow rate: 0.8mL / min
・ Injection volume: 100 μL
・ Eluent: Tetrahydrofuran ・ Detector: Differential refractometer (RI)
Standard sample: polystyrene

(I) Production of optical compensation layer Polymerization was carried out using a batch polymerization apparatus comprising two vertical reactors equipped with a stirring blade and a reflux condenser controlled at 100 ° C. 9,9- [4- (2-hydroxyethoxy) phenyl] fluorene (BHEPF), isosorbide (ISB), diethylene glycol (DEG), diphenyl carbonate (DPC), and magnesium acetate tetrahydrate in a molar ratio of BHEPF / ISB / DEG / DPC / magnesium acetate = 0.348 / 0.490 / 0.162 / 1.005 / 1.00 × 10 ⁻⁵ . After sufficiently replacing the inside of the reactor with nitrogen (oxygen concentration 0.0005 to 0.001 vol%), heating was performed with a heating medium, and stirring was started when the internal temperature reached 100 ° C. After 40 minutes from the start of temperature increase, the internal temperature was reached to 220 ° C., and control was performed so as to maintain this temperature. At the same time, pressure reduction was started, and after reaching 220 ° C., 13.3 kPa was reached in 90 minutes. The phenol vapor produced as a by-product with the polymerization reaction was led to a reflux condenser at 100 ° C., and a monomer component contained in a small amount in the phenol vapor was returned to the reactor, and the phenol vapor not condensed was led to a condenser at 45 ° C. and recovered.

Nitrogen was introduced into the first reactor and the pressure was once restored to atmospheric pressure, and then the oligomerized reaction liquid in the first reactor was transferred to the second reactor. Subsequently, the temperature increase and pressure reduction in the second reactor were started, and the internal temperature was 240 ° C. and the pressure was 0.2 kPa in 50 minutes. Thereafter, polymerization was allowed to proceed until a predetermined stirring power was obtained. When a predetermined power is reached, nitrogen is introduced into the reactor, the pressure is restored, the reaction solution is withdrawn in the form of a strand, pelletized with a rotary cutter, and BHEPF / ISB / DEG = 34.8 / 49.0 / A polycarbonate resin having a copolymer composition of 16.2 [mol%] was obtained. This polycarbonate resin had a reduced viscosity of 0.430 dL / g and a glass transition temperature of 128 ° C.

The obtained polycarbonate resin (10 kg) was dissolved in methylene chloride (73 kg) to prepare a coating solution. Next, the coating liquid was directly applied onto a shrinkable film (vertical uniaxially stretched polypropylene film, manufactured by Tokyo Ink Co., Ltd., trade name “Noblen”), and the coating film was dried at a temperature of 30 ° C. for 5 minutes. The laminate was dried at 80 ° C. for 5 minutes to form a shrinkable film / birefringent layer laminate. The obtained laminate is stretched at a stretching temperature of 155 ° C. using a simultaneous biaxial stretching machine at a stretching ratio of 0.80 in the MD direction and 1.3 times in the TD direction to form a retardation film on the shrinkable film. Formed. Next, the retardation film was peeled from the shrinkable film. The thickness of the retardation film was 60.0 μm, Re (550) = 140 nm, Nz = 0.5, and Re (450) / Re (550) = 0.89. This retardation film was used as an optical compensation layer.

(Ii) Production of polarizer A long roll of polyvinyl alcohol (PVA) resin film (made by Kuraray, product name “PE3000”) having a thickness of 30 μm is longitudinally stretched 5.9 times in the longitudinal direction by a roll stretching machine. While being uniaxially stretched in the direction, swelling, dyeing, crosslinking, and washing treatment were simultaneously performed, and finally, a drying treatment was performed to produce a polarizer having a thickness of 12 μm.
Specifically, the swelling treatment was stretched 2.2 times while being treated with pure water at 20 ° C. Next, the dyeing treatment is performed in an aqueous solution at 30 ° C. in which the weight ratio of iodine and potassium iodide is 1: 7, the iodine concentration of which is adjusted so that the single transmittance of the obtained polarizer is 45.0%. The film was stretched 1.4 times. Furthermore, the crosslinking treatment employed a two-stage crosslinking treatment, and the first-stage crosslinking treatment was stretched 1.2 times while being treated in an aqueous solution in which boric acid and potassium iodide were dissolved at 40 ° C. The boric acid content of the aqueous solution of the first-stage crosslinking treatment was 5.0% by weight, and the potassium iodide content was 3.0% by weight. The cross-linking treatment at the second stage was stretched 1.6 times while being treated in an aqueous solution in which boric acid and potassium iodide were dissolved at 65 ° C. The boric acid content of the aqueous solution of the second crosslinking treatment was 4.3% by weight, and the potassium iodide content was 5.0% by weight. In addition, the cleaning treatment was performed with an aqueous potassium iodide solution at 20 ° C. The potassium iodide content of the aqueous solution for the washing treatment was 2.6% by weight. Finally, the drying process was performed at 70 ° C. for 5 minutes to obtain a polarizer.

(Iii) Production of Polarizing Film HC- having a hard coat (HC) layer formed on one side of the above polarizer by a hard coat treatment on one side of a triacetyl cellulose (TAC) film via a polyvinyl alcohol adhesive. A TAC film (thickness: 32 μm, corresponding to the protective layer) was bonded by roll-to-roll to obtain a long polarizing film having a protective layer / polarizer configuration.

(Iv) Production of polarizing film with optical compensation layer The polarizing film and the optical compensation layer obtained above are cut into a predetermined size, and the polarizer surface of the polarizing film and the optical compensation layer are attached via an acrylic pressure-sensitive adhesive. A polarizing film with an optical compensation layer having a structure of a laminated protective layer / polarizer / optical compensation layer was obtained. The optical compensation layer was cut so that the angle formed by the absorption axis of the polarizer and the slow axis of the optical compensation layer was 45 ° when the polarizing film and the optical compensation layer were bonded together.

<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 pipe, a nitrogen introduction pipe, a thermometer, and a stirring device. Further, 0.1 part of 2,2′-azobisisobutyronitrile as a polymerization initiator was charged with 100 parts of ethyl acetate to 100 parts of the monomer mixture, and nitrogen gas was introduced while gently stirring to introduce nitrogen. After the replacement, the polymerization temperature was kept at around 55 ° C. for 8 hours to carry out a polymerization reaction, and a solution of acrylic polymer having a weight average molecular weight (Mw) of 1.8 million and Mw / Mn = 4.1 (solid content concentration) 30% by weight) was prepared.

(Preparation of pressure-sensitive adhesive compositions used in Reference Examples and Reference Comparative Examples)
For 100 parts solid content of the acrylic polymer solution produced above,
0.3 parts of benzoyl peroxide (trade name Nyper BMT manufactured by NOF Corporation) and 1 part of isocyanate crosslinking agent (trade name Coronate L manufactured by Tosoh Corporation),
Was added to obtain an adhesive composition.

(Preparation of adhesive composition used in Examples and Comparative Examples)
For 100 parts solid content of the acrylic polymer solution produced above,
0.3 parts of benzoyl peroxide (trade name Nyper BMT manufactured by NOF Corporation), 1 part of isocyanate crosslinking agent (trade name Coronate L manufactured by Tosoh Corporation),
0.25 part, 0.5 part, or 1 part of a tetraazaporphyrin-based dye (trade name PD-320 manufactured by Yamamoto Kasei Co., Ltd., having a maximum absorption wavelength at a wavelength of 595 nm), and a phenol-based antioxidant (BASF Japan) 0.5 part of trade name IRGANAOX 1010 manufactured by
Was added to obtain an adhesive composition.

(Preparation of polarizing film with adhesive layer)
The pressure-sensitive adhesive composition was uniformly coated with an applicator on the surface of a polyethylene terephthalate film release substrate (MRF38CK manufactured by Mitsubishi Plastics) treated with a silicone-based release agent, and then in an air circulation type thermostatic oven at 155 ° C. This was performed by drying for 2 minutes to form an adhesive layer having a thickness of 20 μm. Subsequently, the separator film in which the pressure-sensitive adhesive layer was formed was transferred to the optical compensation layer side of the polarizing film with an optical compensation layer to produce a polarizing film with an optical compensation layer with an adhesive layer.

(Production of liquid crystal panel)
A liquid crystal panel (base glass: TFT glass on the viewing side and CF glass on the backlight side) was taken out from a liquid crystal TV (product name: 43UH7710) manufactured by LG, and the polarizing film with adhesive layers on both sides was removed from the liquid crystal cell. . After removing the separator from the pressure-sensitive adhesive layer of the pressure-sensitive adhesive layer prepared above on both sides of the liquid crystal cell from which the pressure-sensitive adhesive layer-attached polarizing film has been removed, the pressure-sensitive adhesive layer of the pressure-sensitive adhesive layer-attached polarizing film is applied. Then, a liquid crystal panel was produced.
In the reference example and the reference comparative example, a polarizing film with an adhesive layer having the same adhesive layer as described above was used on both sides of the liquid crystal cell except that no pigment was contained.
In Examples and Comparative Examples, a polarizing film with an adhesive layer having an adhesive layer having a dye is used on the viewing side of the liquid crystal cell, and an adhesive layer having an adhesive layer having no dye is used on the backlight side. An attached polarizing film was used. In Examples and Comparative Examples, in preparing a polarizing film with a pressure-sensitive adhesive layer having a pressure-sensitive adhesive layer having a dye, the colorant to be blended in the pressure-sensitive adhesive composition forming the pressure-sensitive adhesive layer was changed as shown in Table 1. A thing was used.

(Backlight)
Only the backlight (light source) was taken out from the following products.
Light source: Its configuration: The name of the product from which the light source was taken out is as follows.
CD: BLED + QD (Green) + QD (Red): Kindle Fire HD 7 from Amazon
CdFreeQD: BLED + CdFreeQD (Green) + QDCdFree (Red): Samsung UN65JS9000FXZA
KSF: BLED + Phosphor0 (Green) + KSF (Red): Sony xperia z4 tablet
Phosphor (1): BLED + Phosphor1 (Green) + phosphor1 (Red) LG 43UF7500
Phosphor (2): BLED + Phosphor2 (Green) + phosphor2 (Red) LG made 43UH7710
The emission spectrum of each backlight is shown in Table 1.
The emission spectrum was measured with SR-UL1 manufactured by Topcon Technohouse.

Reference Examples 1-3, Examples 1-3, Comparative Reference Examples 1-2, Comparative Examples 1-2
As shown in Table 1, a liquid crystal display device was produced by combining the liquid crystal panel produced above and a backlight.

The following evaluation was performed on the liquid crystal panels and liquid crystal display devices obtained in the above Reference Examples, Examples, Comparative Reference Examples and Comparative Examples. The evaluation results are shown in Table 1.

(Measurement of brightness)
For the liquid crystal display device produced in each example, the front luminance when white was displayed in a dark room was measured using a color luminance meter (SR-UL1 manufactured by Topcon Technohouse Co., Ltd.). Table 1 also shows the luminance reduction rate (%) based on the luminance (the luminance of the reference example or comparative reference example) when the pressure-sensitive adhesive layer having no pigment is used.
Decrease rate of luminance (%) = [{(brightness of reference example or comparative reference example) − (brightness of example or comparative example)} / (brightness of reference example or comparative reference example)] × 100

(Measurement of reflectance of liquid crystal panel)
The liquid crystal panel produced in each example was measured with a D65 light source using a product name “CM-2600d” manufactured by Konica Minolta by the SCE method without specular reflection. The measurement temperature was 23 ° C. The average value of 2 repetitions was taken as the measured value.
Table 1 also shows the reduction rate (%) of the reflectance based on the reflectance (reflectance of the reference example or comparative reference example) when the pressure-sensitive adhesive layer having no pigment is used.
Reduction rate of reflectance (%) = [{(reflectance of reference example or comparative reference example) − (reflectance of example or comparative example)} / (reflectance of reference example or comparative reference example)] × 100

<Measurement of transmittance of adhesive layer>
Using the liquid crystal panels obtained in the above reference examples, examples, comparative reference examples and comparative examples, and a standard backlight taken out from a liquid crystal TV manufactured by LG (product name: 43UH7710) used for the production of the liquid crystal panel. The “maximum absorption wavelength” transmittance of the pressure-sensitive adhesive layer was measured by the following method. For the following luminance, each 595 nm data was used from spectral data measured using a color luminance meter (SR-UL1 manufactured by Topcon Technohouse Co., Ltd.).
(1) The liquid crystal panels obtained in Examples and Comparative Examples were assembled with a standard backlight to produce a liquid crystal display device, and the luminance (L ₅₉₅ (n)) of the liquid crystal display device was measured.
(2) The liquid crystal panel and the standard backlight used in the reference example and the comparative reference example were assembled to prepare a liquid crystal display device, and the luminance (L ₅₉₅ (ref)) of the liquid crystal display device was measured.
From these, the transmittance of the maximum absorption wavelength of the pressure-sensitive adhesive layer was derived by the following formula.
Transmittance (%) of maximum absorption wavelength of adhesive layer = [L ₅₉₅ (n) / L ₅₉₅ (ref)] × 100
Note that the pressure-sensitive adhesive layers used in the examples and comparative examples all have the same composition (the same amount of change in the amount of the dye is added). Therefore, the transmittance | permeability of the adhesive layer of the same pigment | dye compounding quantity in an Example and a comparative example is all the same. The transmittance of the reference example and the comparative reference example is 100 (%) indicating the value of [L ₅₉₅ (ref) / L ₅₉₅ (ref)].

As shown in Table 1, it can be seen that the reduction rate of the brightness of the example is smaller than that of the comparative example. In addition, the optical functional layer (adhesive layer) containing the dye is considered to have a function of reducing the reflectance as a function of the dye itself, but the luminance reduction rate of the example is the reflectance reduction rate. Compared to this, the present invention is small, and in the present invention, a decrease in luminance is effectively suppressed.

PN liquid crystal panel C liquid crystal cell A1 1st optical functional layer A2 2nd optical functional layer P1 1st polarizing film P2 2nd polarizing film BL Backlight

Claims (12)

1. A liquid crystal cell, a liquid crystal panel having a first polarizing film disposed on the viewing side of the liquid crystal cell, a second polarizing film disposed on the back side of the liquid crystal cell, and a liquid crystal display device having a backlight unit In
   The liquid crystal panel has a maximum absorption wavelength in a wavelength range of 570 to 610 nm, and
   The backlight unit is
   Having a peak intensity (Gp) of an emission spectrum in a wavelength range of 515 to 545 nm,
   Having a peak intensity (Rp) of an emission spectrum in a wavelength range of 605 to 650 nm, and
   The average value (Ave1) of the emission spectrum intensity in the wavelength range of 580 to 600 nm and the Gp, Rp and the following formula (1)
   Ave1 ≦ 0.3 × {(Gp + Rp) / 2} (1)
   A liquid crystal display device characterized by satisfying
2. The liquid crystal panel has a first optical functional layer disposed on the viewing side with respect to the liquid crystal cell, and a second optical functional layer disposed on the back side with respect to the liquid crystal cell, the first optical functional layer and The liquid crystal display device according to claim 1, wherein at least one of the second optical functional layers contains a dye having a maximum absorption wavelength in a wavelength range of 570 to 610 nm.
3. The liquid crystal display device according to claim 2, wherein the transmittance of the maximum absorption wavelength of at least one of the first optical functional layer and the second optical functional layer is 50% or less.
4. 4. The liquid crystal display device according to claim 3, wherein at least the first optical functional layer contains the dye.
5. The liquid crystal display device according to claim 3 or 4, wherein the dye is a tetraazaporphyrin-based dye.
6. 6. The pigment according to claim 3, wherein the pigment is contained in an amount of 0.01 to 5 parts by weight based on 100 parts by weight of a solid material of the base material forming the resin layer of the optical function layer. Liquid crystal display device.
7. A liquid crystal cell, a liquid crystal panel having a first polarizing film disposed on the viewing side of the liquid crystal cell, a second polarizing film disposed on the back side of the liquid crystal cell, and a liquid crystal display device having a backlight unit In
   The liquid crystal panel has a maximum absorption wavelength in a wavelength range of 470 to 510 nm, and
   The backlight unit is
   It has a peak intensity (Bp) of an emission spectrum in a wavelength range of 430 to 480 nm,
   Having a peak intensity (Gp) of an emission spectrum in a wavelength range of 515 to 545 nm, and
   The average value (Ave2) of the emission spectrum intensity in the wavelength range of 480 to 500 nm (Ave2) is the following formula (2)
   Ave2 ≦ 0.15 × {(Bp + Gp) / 2} (2)
   A liquid crystal display device characterized by satisfying
8. The liquid crystal panel has a first optical functional layer disposed on the viewing side with respect to the liquid crystal cell, and a second optical functional layer disposed on the back side with respect to the liquid crystal cell, the first optical functional layer and 8. The liquid crystal display device according to claim 7, wherein at least one of the second optical functional layers contains a dye having a maximum absorption wavelength in a wavelength range of 470 to 510 nm.
9. The liquid crystal display device according to claim 8, wherein the transmittance of the maximum absorption wavelength of at least one of the first optical functional layer and the second optical functional layer is 50% or less.
10. 10. The liquid crystal display device according to claim 9, wherein at least the first optical functional layer contains the dye.
11. 11. The liquid crystal display device according to claim 9, wherein the dye is at least one selected from tetraazaporphyrin dyes and cyanine dyes.
12. 12. The dye according to claim 9, wherein the dye is contained in an amount of 0.01 to 5 parts by weight based on 100 parts by weight of a solid material of the base material forming the resin layer of the optical function layer. Liquid crystal display device.
    

Images