JP2009145397A - Set of polarizing plates and liquid crystal panel and liquid crystal display device using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a set of polarizing plates capable of improving strength of a liquid crystal panel, reducing its wall thickness, preventing its surface from being damaged and warping and to provide a liquid crystal display device of excellent visibility and the liquid crystal panel using this set. <P>SOLUTION: The set of polarizing plates is composed of the first and second polarizing plates. The first polarizing plate has a first polarizing film made of polyvinyl alcohol resin and a first acrylic resin film laminated on one face of the first polarizing film. The second polarizing plate includes at least a second polarizing film made of polyvinyl alcohol resin and a second acrylic resin film laminated on face of the second polarizing film and has a glare-proof film having a haze value of 0.1% or more and 45% or less. The liquid crystal panel and the liquid crystal display device using the set are provided. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a set of polarizing plates for a liquid crystal panel, and a liquid crystal panel and a liquid crystal display device using the same.

  A polarizing plate is a component of a liquid crystal panel, which is a main member of a liquid crystal display device, and is usually provided on one or both sides of a polarizing film made of a polyvinyl alcohol resin to which a dichroic dye is adsorbed and oriented via an adhesive layer. A protective film, for example, a cellulose acetate-based transparent resin film typified by triacetylcellulose is laminated. A liquid crystal panel is obtained by sticking this to a liquid crystal cell using an adhesive via another optical film if necessary.

  Applications of liquid crystal display devices are rapidly expanding as thin display screens such as liquid crystal televisions, liquid crystal monitors, and personal computers. In particular, the market for liquid crystal televisions is remarkably expanding, and the demand for cost reduction is very strong. Conventionally, as a polarizing plate for a liquid crystal television, a triacetyl cellulose film (TAC film) is laminated on both sides of a polarizing film made of a polyvinyl alcohol resin film using an aqueous adhesive, and an adhesive is applied to one side of the polarizing plate. A film having a retardation film attached thereto is used. As the retardation film laminated on the polarizing plate, a stretched product of a polycarbonate-based resin film or a stretched product of a cycloolefin-based resin film is used. Retardation films composed of very few cycloolefin resin films are frequently used.

In the pasted product of polarizing plate and retardation film made of stretched cycloolefin-based resin film, attempts have been made to reduce the number of components and simplify the manufacturing process for the purpose of improving productivity and reducing product cost. Has been made. For example, in Patent Document 1 (see particularly Example 4), a TAC film is laminated on one side of a polarizing film, and a cycloolefin type (norbornene type) having a retardation function without using a TAC film on the opposite side. ) A structure in which resin films are laminated is disclosed.
JP-A-8-43812

In large-screen liquid crystal television applications, for example, wall-mounted television applications, the need for further thinning and lightening of liquid crystal display devices has become apparent. In this case, the following points are problems regarding the liquid crystal panel and its components.
(1) When the liquid crystal panel is applied to a large-screen wall-mounted television, it is considered that there are many opportunities to touch human hands, and it is easy to get dust, and the cleaning of the screen increases. In this case, That is, the outermost surface of the polarizing plate needs to be hardly damaged by friction due to the contact.
(2) It is necessary to reinforce the strength of the liquid crystal panel in response to the thin and large screen of the liquid crystal panel.
(3) In response to the thinning of liquid crystal televisions, it is necessary to reduce the thickness of the members used.
(4) A gap between the liquid crystal panel and the backlight system on the back surface is narrowed, and it is necessary to prevent circular unevenness and Newton's ring caused by contact between the liquid crystal panel and the backlight system.

  As a result of diligent research to solve the above-mentioned problems, the present inventors laminated an acrylic resin film on one side of a polarizing film made of a polyvinyl alcohol resin as two polarizing plates that are components of a liquid crystal panel. A combination of a polarizing plate and a polarizing plate obtained by laminating an anti-glare film having an acrylic resin film on one side of a polarizing film made of a polyvinyl alcohol resin and having a haze value of 0.1% to 45%. By using the present invention, it has been found that a liquid crystal panel and a liquid crystal display device excellent in mechanical strength and scratch resistance, can be prevented from warping, and excellent in visibility can be obtained even when thin. Completed.

  That is, according to the present invention, a set of polarizing plates for a liquid crystal panel comprising a first polarizing plate and a second polarizing plate, wherein the first polarizing plate comprises a first polarizing film comprising a polyvinyl alcohol-based resin and And a first acrylic resin film laminated on one side of the first polarizing film, and the second polarizing plate comprises a second polarizing film made of a polyvinyl alcohol resin, and the second polarizing film. There is provided a set of polarizing plates having an anti-glare film laminated on one surface of a polarizing film and having a haze value in the range of 0.1% to 45%. In the present invention, the antiglare film includes at least a second acrylic resin film.

  Here, the 1st polarizing plate further has the optical compensation film or protective film laminated | stacked on the surface on the opposite side to the surface where the 1st acrylic resin film in the 1st polarizing film was laminated | stacked. Also good. Moreover, the 2nd polarizing plate may further have the optical compensation film or protective film laminated | stacked on the surface on the opposite side to the surface where the anti-glare film in the 2nd polarizing film was laminated | stacked.

  In addition, according to the present invention, there is provided a liquid crystal panel in which the first polarizing plate, the liquid crystal cell, and the second polarizing plate are arranged in this order. In the liquid crystal panel of the present invention, the first polarizing plate is disposed such that the surface of the first polarizing film opposite to the surface on which the first acrylic resin film is laminated faces the liquid crystal cell. . In addition, the second polarizing plate is disposed so that the surface opposite to the surface on which the antiglare film of the second polarizing film is laminated faces the liquid crystal cell.

  Furthermore, according to the present invention, there is provided a liquid crystal display device comprising a backlight, a light diffusion plate, and a liquid crystal panel in this order, wherein the liquid crystal panel is the liquid crystal panel of the present invention. In the liquid crystal display device of the present invention, the liquid crystal panel is disposed such that the first polarizing plate faces the light diffusion plate. The liquid crystal display device of the present invention may have a brightness enhancement sheet between the light diffusing plate and the liquid crystal panel. In this case, the liquid crystal panel has a first polarizing plate facing the brightness enhancement sheet. Placed in.

  According to the set (combination) of specific polarizing plates according to the present invention, the use of an acrylic resin film improves the mechanical strength of the liquid crystal panel, reduces the thickness, and prevents the surface from being scratched. Contact with a backlight system including a light diffusing plate by preventing warpage of the panel can be avoided, circular unevenness and Newton's ring can be prevented, and visibility can be improved. In addition, since the acrylic resin film is a film that hardly develops a phase difference, even when a sheet or film having polarization characteristics such as a brightness enhancement sheet is disposed between the liquid crystal panel and the backlight, While maintaining the characteristics, it is possible to prevent problems such as color unevenness (interference unevenness) caused by the sheet or film. Such a set of polarizing plates and a liquid crystal panel using the same can be suitably applied to a liquid crystal display device for a large-screen liquid crystal television, in particular, a liquid crystal display device for a liquid crystal television that can be wall-mounted.

<Polarizing plate>
The set of polarizing plates of the present invention comprises two polarizing plates, a first polarizing plate and a second polarizing plate, which are used as components of a liquid crystal panel. The liquid crystal panel can be produced by laminating the first polarizing plate on one surface of the liquid crystal cell and laminating the second polarizing plate on the other surface. The first polarizing plate is used as a back side polarizing plate of the liquid crystal panel, and the second polarizing plate is used as a front side polarizing plate of the liquid crystal panel. Here, “back-side polarizing plate” means a polarizing plate located on the backlight side when the liquid crystal panel is mounted on a liquid crystal display device, and “front-side polarizing plate” means that the liquid crystal panel is displayed on a liquid crystal display. It means a polarizing plate located on the viewing side when mounted on the apparatus. Hereinafter, each polarizing plate will be described in detail.

(First polarizing plate)
The first polarizing plate is used as a back side polarizing plate of a liquid crystal panel, and is produced by laminating a first acrylic resin film on one side of a first polarizing film made of a polyvinyl alcohol resin. . Specifically, the first polarizing film is obtained by adsorbing and orienting a dichroic dye on a uniaxially stretched polyvinyl alcohol resin film.

  As the polyvinyl alcohol resin, a saponified polyvinyl acetate resin can be used. Examples of the polyvinyl acetate resin include polyvinyl acetate, which is a homopolymer of vinyl acetate, and copolymers with other monomers copolymerizable with vinyl acetate. Examples of other monomers copolymerizable with vinyl acetate include unsaturated carboxylic acids, olefins, vinyl ethers, unsaturated sulfonic acids, and acrylamides having an ammonium group.

  The saponification degree of the polyvinyl alcohol resin is usually about 85 to 100 mol%, preferably 98 mol% or more. This polyvinyl alcohol-based resin may be further modified, and for example, polyvinyl formal or polyvinyl acetal modified with aldehydes may be used. The degree of polymerization of the polyvinyl alcohol resin is usually about 1,000 to 10,000, preferably about 1,500 to 5,000.

  A film obtained by forming such a polyvinyl alcohol-based resin is used as a raw film of the first polarizing film. The method for forming a polyvinyl alcohol-based resin is not particularly limited, and can be formed by a known method. Although the thickness of a polyvinyl alcohol-type raw film is not specifically limited, For example, it is about 10 micrometers-150 micrometers.

  The first polarizing film is usually a step of uniaxially stretching such a polyvinyl alcohol resin film, a step of adsorbing a dichroic dye by dyeing the polyvinyl alcohol resin film with a dichroic dye, two colors It is manufactured through a step of treating a polyvinyl alcohol-based resin film adsorbed with a functional dye with an aqueous boric acid solution and a step of washing with water after the treatment with an aqueous boric acid solution.

  Uniaxial stretching of the polyvinyl alcohol-based resin film may be performed before the dichroic dye is dyed, may be performed simultaneously with the dyeing, or may be performed after the dyeing. When uniaxial stretching is performed after dyeing, the uniaxial stretching may be performed before boric acid treatment or during boric acid treatment. Of course, it is also possible to perform uniaxial stretching in these plural stages. In uniaxial stretching, it may be uniaxially stretched between rolls having different peripheral speeds, or may be uniaxially stretched using a hot roll. The uniaxial stretching may be dry stretching in which stretching is performed in the atmosphere, or may be wet stretching in which stretching is performed in a state where a solvent is used and the polyvinyl alcohol-based resin film is swollen. The draw ratio is usually about 3 to 8 times.

  Examples of a method for dyeing a polyvinyl alcohol resin film with a dichroic dye include a method of immersing a polyvinyl alcohol resin film in an aqueous solution containing a dichroic dye. Specifically, iodine or a dichroic dye is used as the dichroic dye. In addition, it is preferable that the polyvinyl alcohol-type resin film is immersed in water before the dyeing process.

  When iodine is used as the dichroic dye, a method of dyeing a polyvinyl alcohol-based resin film in an aqueous solution containing iodine and potassium iodide is usually employed. The content of iodine in this aqueous solution is usually about 0.01 to 1 part by weight per 100 parts by weight of water, and the content of potassium iodide is usually about 0.5 to 20 parts by weight per 100 parts by weight of water. It is. The temperature of the aqueous solution used for dyeing is usually about 20 to 40 ° C., and the immersion time (dyeing time) in this aqueous solution is usually about 20 to 1,800 seconds.

On the other hand, when a dichroic dye is used as the dichroic dye, a method of immersing and dyeing a polyvinyl alcohol-based resin film in an aqueous solution containing a water-soluble dichroic dye is usually employed. The content of the dichroic dye in this aqueous solution is usually about 1 × 10 ⁻⁴ to 10 parts by weight, preferably about 1 × 10 ⁻³ to 1 part by weight per 100 parts by weight of water. It may be about ^10-2 parts by weight or less. This aqueous solution may contain an inorganic salt such as sodium sulfate as a dyeing assistant. The temperature of the aqueous dichroic dye solution used for dyeing is usually about 20 to 80 ° C., and the immersion time (dyeing time) in this aqueous solution is usually about 10 to 1,800 seconds.

  The boric acid treatment after dyeing with the dichroic dye can be performed by immersing the dyed polyvinyl alcohol-based resin film in a boric acid-containing aqueous solution. The amount of boric acid in the boric acid-containing aqueous solution is usually about 2 to 15 parts by weight, preferably about 5 to 12 parts by weight per 100 parts by weight of water. When iodine is used as the dichroic dye, the boric acid-containing aqueous solution preferably contains potassium iodide. The amount of potassium iodide in the boric acid-containing aqueous solution is usually about 0.1 to 15 parts by weight, preferably about 5 to 12 parts by weight per 100 parts by weight of water. The immersion time in the boric acid-containing aqueous solution is usually about 60 to 1,200 seconds, preferably about 150 to 600 seconds, and more preferably about 200 to 400 seconds. The temperature of the boric acid-containing aqueous solution is usually 50 ° C. or higher, preferably 50 to 85 ° C., more preferably 60 to 80 ° C.

  The polyvinyl alcohol resin film after the boric acid treatment is usually washed with water. The water washing treatment can be performed, for example, by immersing a boric acid-treated polyvinyl alcohol resin film in water. The temperature of water in the water washing treatment is usually about 5 to 40 ° C., and the immersion time is usually about 1 to 120 seconds. After washing with water, a drying process is performed to obtain a first polarizing film. The drying treatment can be performed using a hot air dryer or a far infrared heater. The temperature of the drying treatment is usually about 30 to 100 ° C, preferably 50 to 80 ° C. The time for the drying treatment is usually about 60 to 600 seconds, preferably 120 to 600 seconds.

  In this way, the polyvinyl alcohol-based resin film is subjected to uniaxial stretching, dyeing with a dichroic dye, and boric acid treatment to obtain a first polarizing film. The thickness of the first polarizing film can be, for example, about 5 to 40 μm.

  The 1st polarizing plate which concerns on this invention is produced by laminating | stacking a 1st acrylic resin film on the single side | surface of the 1st polarizing film which consists of the said polyvinyl alcohol-type resin. The acrylic resin film is a film that is excellent in mechanical properties, solvent resistance, scratch resistance, light resistance, transparency, cost and the like, and hardly exhibits a retardation. According to the polarizing plate using such an acrylic resin film, it is possible to achieve improvement in mechanical strength and thinning of the liquid crystal panel, and visibility with suppressed color unevenness due to phase difference, etc. An excellent liquid crystal panel and liquid crystal display device can be obtained.

  The acrylic resin constituting the first acrylic resin film means a material obtained by mixing, melting, and kneading a methacrylic resin and an additive added as necessary.

  The methacrylic resin is a polymer mainly composed of methacrylic acid ester. The methacrylic resin may be a homopolymer of one kind of methacrylic acid ester or a copolymer of methacrylic acid ester with other methacrylic acid ester or acrylic acid ester. Examples of the methacrylic acid esters include alkyl methacrylates such as methyl methacrylate, ethyl methacrylate, and butyl methacrylate, and the alkyl group usually has about 1 to 4 carbon atoms. The acrylic ester that can be copolymerized with the methacrylic ester is preferably an alkyl acrylate, such as methyl acrylate, ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, and the like. The number of carbon atoms in the group is usually about 1-8. In addition to these, the copolymer contains an aromatic vinyl compound such as styrene which is a compound having at least one polymerizable carbon-carbon double bond in the molecule, a vinyl cyanide compound such as acrylonitrile, and the like. Also good.

  The acrylic resin preferably contains acrylic rubber particles from the viewpoint of impact resistance and film forming property of the film. The amount of acrylic rubber particles that can be contained in the acrylic resin is preferably 5% by weight or more, more preferably 10% by weight or more. The upper limit of the amount of the acrylic rubber particles is not critical, but if the amount of the acrylic rubber particles is too large, the surface hardness of the film is lowered, and when the film is subjected to surface treatment, it is resistant to the organic solvent in the surface treatment agent. Solvent property decreases. Therefore, the amount of acrylic rubber particles that can be contained in the acrylic resin is preferably 80% by weight or less, and more preferably 60% by weight or less.

  The acrylic rubber particles are particles containing an elastic polymer mainly composed of an acrylate ester as an essential component. The acrylic rubber particles may have a single-layer structure consisting essentially only of the elastic polymer. It may have a multi-layer structure in which the coalescence is one layer. Specifically, as this elastic polymer, 50 to 99.9% by weight of an alkyl acrylate and at least one kind of other vinyl monomer copolymerizable therewith, 0 to 49.9% by weight, A cross-linked elastic copolymer obtained by polymerization of a monomer comprising 0.1 to 10% by weight of a polymerizable cross-linkable monomer is preferably used.

  Examples of the alkyl acrylate include methyl acrylate, ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate, and the like, and the alkyl group usually has about 1 to 8 carbon atoms. Examples of the other vinyl monomers copolymerizable with the alkyl acrylate include compounds having one polymerizable carbon-carbon double bond in the molecule. Examples thereof include methacrylic acid esters such as methyl acid, aromatic vinyl compounds such as styrene, vinylcyan compounds such as acrylonitrile, and the like. Examples of the copolymerizable crosslinkable monomer include a crosslinkable compound having at least two polymerizable carbon-carbon double bonds in the molecule. (Meth) acrylates of polyhydric alcohols such as (meth) acrylate and butanediol di (meth) acrylate, alkenyl esters of (meth) acrylic acid such as allyl (meth) acrylate and methallyl (meth) acrylate, divinyl Examples include benzene. In this specification, (meth) acrylate refers to methacrylate or acrylate, and (meth) acrylic acid refers to methacrylic acid or acrylic acid.

  In addition to the acrylic rubber particles, the acrylic resin contains normal additives such as ultraviolet absorbers, organic dyes, pigments, inorganic dyes, antioxidants, antistatic agents, surfactants, and the like. Also good. Among these, an ultraviolet absorber is preferably used for improving weather resistance. Examples of the ultraviolet absorber include 2,2′-methylenebis [4- (1,1,3,3-tetramethylbutyl) -6- (2H-benzotriazol-2-yl) phenol], 2- (5 -Methyl-2-hydroxyphenyl) -2H-benzotriazole, 2- [2-hydroxy-3,5-bis (α, α-dimethylbenzyl) phenyl] -2H-benzotriazole, 2- (3,5-di -Tert-butyl-2-hydroxyphenyl) -2H-benzotriazole, 2- (3-tert-butyl-5-methyl-2-hydroxyphenyl) -5-chloro-2H-benzotriazole, 2- (3,5 -Di-tert-butyl-2-hydroxyphenyl) -5-chloro-2H-benzotriazole, 2- (3,5-di-tert-amyl-2-hydroxypheny ) Benzotriazole ultraviolet absorbers such as -2H-benzotriazole, 2- (2'-hydroxy-5'-tert-octylphenyl) -2H-benzotriazole; 2-hydroxy-4-methoxybenzophenone, 2- Hydroxy-4-octyloxybenzophenone, 2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxy-4'-chlorobenzophenone, 2,2'-dihydroxy-4-methoxybenzophenone, 2,2'-dihydroxy-4, Examples include 2-hydroxybenzophenone ultraviolet absorbers such as 4′-dimethoxybenzophenone; salicylic acid phenyl ester ultraviolet absorbers such as p-tert-butylphenyl salicylic acid ester and p-octylphenyl salicylic acid ester. It may be used two or more thereof. When the acrylic resin contains an ultraviolet absorber, the amount is usually 0.1% by weight or more, preferably 0.3% by weight or more, and preferably 2% by weight or less.

  As a method for obtaining the first acrylic resin film, various generally known methods such as a method using a feed block and a method using a multi-manifold die can be used. Among them, for example, a method of laminating via a feed block, multilayer melt extrusion from a T-die, and forming a film by bringing at least one surface of the obtained laminated film into contact with a roll or a belt is a film having good surface properties. It is preferable at the point obtained. In particular, from the viewpoint of improving the surface smoothness and surface gloss of an acrylic resin film, a method of forming a film by bringing both surfaces of a laminated film-like material obtained by multilayer melt extrusion molding into contact with the roll surface or belt surface Is preferred. In the roll or belt used in this case, the surface of the roll or belt in contact with the acrylic resin is preferably a mirror surface in order to impart smoothness to the acrylic resin film surface.

  The first acrylic resin film may be provided with haze. The method for imparting haze is not particularly limited. For example, a method of mixing inorganic fine particles or organic fine particles in the raw material resin (acrylic resin), or the first polarizing film in the first acrylic resin film, For example, a method of coating a coating liquid in which inorganic fine particles or organic fine particles are mixed with a resin binder on the surface opposite to the surface to be attached can be used. Typical inorganic fine particles include silica, colloidal silica, alumina, alumina sol, aluminosilicate, alumina-silica composite oxide, kaolin, talc, mica, calcium carbonate, calcium phosphate, and the like. Further, as the organic fine particles, resin particles such as crosslinked polyacrylic acid particles, crosslinked polystyrene particles, crosslinked polymethyl methacrylate particles, silicone resin particles, and polyimide particles can be used.

  On the surface of the first acrylic resin film opposite to the surface to be attached to the first polarizing film, in addition to the above antiglare treatment (haze imparting treatment), hard coat treatment, antistatic treatment, etc. The surface treatment may be performed. In addition, a coat layer made of a liquid crystalline compound or a high molecular weight compound thereof may be formed.

  The thickness of the first acrylic resin film is preferably about 20 to 120 μm, and more preferably about 30 to 80 μm. When the thickness of the film is less than 20 μm, handling tends to be difficult, and when the thickness exceeds 120 μm, the merit of thinning tends to be reduced.

  In the first polarizing plate, an adhesive for bonding the liquid crystal cell and the polarizing plate to the surface of the first polarizing film opposite to the surface on which the first acrylic resin film is bonded. An agent or pressure-sensitive adhesive layer may be formed. Further, a transparent film such as a protective film or an optical compensation film is laminated on the surface of the first polarizing film opposite to the surface on which the first acrylic resin film is bonded, and the transparent film Alternatively, an adhesive or pressure-sensitive adhesive layer may be formed. Examples of the transparent film include a cellulose film such as a triacetyl cellulose film (TAC film), an olefin film, an acrylic film, and a polyester film. Furthermore, an optical functional film described later can be laminated on the transparent film, and an adhesive or pressure-sensitive adhesive layer can be formed on the optical functional film.

  The cellulose film is a film made of a partially esterified product or a completely esterified product of cellulose, and examples thereof include a film made of cellulose acetate ester, propionate ester, butyrate ester, and mixed ester thereof. More specifically, a triacetyl cellulose film, a diacetyl cellulose film, a cellulose acetate propionate film, a cellulose acetate butyrate film, and the like can be given. As such a cellulose ester film, an appropriate commercially available product, for example, Fujitac TD80 (Fuji Film Co., Ltd.), Fujitac TD80UF (Fuji Film Co., Ltd.), Fujitac TD80UZ (Fuji Film Co., Ltd.), KC8UX2M (manufactured by Konica Minolta Opto Co., Ltd.), KC8UY (manufactured by Konica Minolta Opto Co., Ltd.) and the like can be used.

  Examples of the optical compensation film comprising a cellulose film include, for example, a film in which a compound having a retardation adjusting function is contained in a cellulose film, a film in which a compound having a retardation adjusting function is applied to the surface of a cellulose film, cellulose Examples thereof include a film obtained by uniaxially or biaxially stretching a system film. As commercially available cellulose-based optical compensation films, for example, “WV BZ 438” and “WV EA”, which are sold in the series of “WV Film” from FUJIFILM Corporation, Konica Minolta Opto ( And "KC4FR-1" and "KC4HR-1" sold by the company.

  Examples of the optical compensation film made of the olefin-based film include an optical compensation film obtained by uniaxially stretching or biaxially stretching a cycloolefin-based resin film. When the set of polarizing plates of the present invention is used for a liquid crystal panel for a large-sized liquid crystal television, particularly a liquid crystal panel having a vertical alignment (VA) mode liquid crystal cell, a stretched product of a cycloolefin resin film is used as the optical compensation film. However, it is also preferable from the viewpoint of optical characteristics and durability. Here, the cycloolefin resin film is a film made of a thermoplastic resin having a unit of a monomer made of a cyclic olefin (cycloolefin) such as norbornene or a polycyclic norbornene monomer. The cycloolefin-based resin film may be a hydrogenated product of a ring-opening polymer using a single cycloolefin or a ring-opening copolymer using two or more kinds of cycloolefins. And / or an addition copolymer with an aromatic compound having a vinyl group. Further, those having a polar group introduced into the main chain or side chain are also effective.

  In the case of using a copolymer of a cycloolefin and a chain olefin and / or an aromatic compound having a vinyl group, examples of the chain olefin include ethylene, propylene and the like, and also an aromatic compound having a vinyl group. Examples include styrene, α-methyl styrene, nuclear alkyl-substituted styrene and the like. In such a copolymer, the monomer unit composed of cycloolefin may be 50 mol% or less, for example, about 15 to 50 mol%. In particular, when a ternary copolymer of a cycloolefin, a chain olefin, and an aromatic compound having a vinyl group is used, the amount of monomer units made of cycloolefin can be made relatively small. In such a terpolymer, the unit of monomer composed of a chain olefin is usually about 5 to 80 mol%, and the unit of monomer composed of an aromatic compound having a vinyl group is usually about 5 to 80 mol%.

  Commercially available thermoplastic cycloolefin-based resins include “Topas” sold by Ticona, Germany, “Arton” sold by JSR Corporation, and “Zeonor” sold by Nippon Zeon Corporation. ZEONOR ”and“ ZEONEX ”,“ Appel ”(all trade names) sold by Mitsui Chemicals, Inc., and the like, which can be suitably applied to the cycloolefin resin film. . A cycloolefin resin film can be obtained by forming such a cycloolefin resin. As a film forming method, a known method such as a solvent casting method or a melt extrusion method is appropriately used. Also, for example, “Essina” and “SCA40” sold by Sekisui Chemical Co., Ltd., “Zeonor Film” sold by Optes Co., Ltd., “Arton Film” sold by JSR Co., Ltd. Cycloolefin-based resin films (such as trade names) are also commercially available, and these can also be suitably used.

The cycloolefin-based resin film as the optical compensation film is desirably stretched in at least one direction. Thereby, an appropriate optical compensation function is provided, which can contribute to the expansion of the viewing angle of the liquid crystal display device. The in-plane retardation value R ₀ of the stretched cycloolefin-based resin film is preferably 40 nm or more and 100 nm or less, and more preferably 40 nm or more and 80 nm or less. When the in-plane retardation value R ₀ is less than 40 nm or exceeds 100 nm, the viewing angle compensation ability for the liquid crystal panel tends to be lowered. Further, the thickness direction retardation value R _th of the stretched cycloolefin-based resin film is preferably 80 nm or more and 250 nm or less, and more preferably 100 nm or more and 250 nm or less. When the thickness direction retardation value _Rth is less than 80 nm or exceeds 250 nm, the viewing angle compensation ability with respect to the liquid crystal panel tends to be reduced as described above. The in-plane retardation value R ₀ and the thickness direction retardation value R _th of the stretched cycloolefin-based resin film are represented by the following formulas (1) and (2), respectively.

_{R 0 = (n x -n y} ) × d (1)
R _th = [( _nx + _ny ) / 2- _nz ] × d (2)
Here, n _x plane slow axis direction of the refractive index of the cycloolefin resin film stretched, n _y is a refractive index in the in-plane fast axis direction (perpendicular to the plane slow axis direction), _nz is the refractive index in the thickness direction of the stretched cycloolefin resin film, and d is the thickness of the stretched cycloolefin resin film.

  The preferable refractive index characteristics as described above include various adjustments such as preheating temperature during stretching, stretching temperature, heat setting (film strain reduction treatment after stretching) temperature, cooling temperature, etc. in addition to appropriately adjusting the stretching ratio and stretching speed. It can be applied by appropriately selecting the temperature (including the temperature pattern). The preferred refractive index characteristics as described above can be obtained by stretching under relatively loose conditions. For example, the draw ratio is preferably in the range of 1.05 times to 1.6 times, more preferably 1.1 times to 1.5 times. In the case of biaxial stretching, the stretching ratio in the maximum stretching direction may be in the above range.

  If the thickness d of the stretched cycloolefin-based resin film is too thick, the processability is inferior, and problems such as a decrease in transparency and an increase in the weight of the polarizing plate tend to occur. Therefore, the thickness d of the stretched cycloolefin-based resin film is preferably about 40 μm to 80 μm.

  As a protective film or optical compensation film laminated on the first acrylic resin film and / or on the surface of the first polarizing film opposite to the surface to which the first acrylic resin film is bonded. On the transparent film, an optical functional film may be stuck via an adhesive. As the optical functional film, in addition to the optical compensation film based on the cellulose-based film or the cycloolefin-based film described above, for example, an optical compensation film in which a liquid crystal compound is applied to the substrate surface and oriented, Reflective polarizing film that transmits certain types of polarized light and reflects polarized light that is the opposite of that, retardation film made of polycarbonate resin, film with anti-glare function having an uneven surface, surface anti-reflection treatment Examples thereof include an attached film, a reflective film having a reflective function on the surface, and a transflective film having both a reflective function and a transmissive function. Commercial products corresponding to the optical compensation film coated with liquid crystal compound on the substrate surface and oriented are "WV film" sold by Fuji Film Co., Ltd. and sold by Nippon Oil Corporation. “NH film” and “NR film” (both are trade names). A commercial product corresponding to a reflective polarizing film that transmits certain types of polarized light and reflects polarized light exhibiting the opposite properties is sold by 3M Company (3M) (Sumitomo 3M in Japan). “DBEF” and “APF” (both are trade names).

  Next, a method for laminating a first acrylic resin film and / or a transparent film as the above-described protective film or optical compensation film on the first polarizing film will be described. As a method of laminating the first acrylic resin film and / or transparent film on the first polarizing film surface, a method of adhering using an adhesive is usually employed. When an adhesive is used on both sides of the first polarizing film, the same type of adhesive on both sides may be used, or a different type of adhesive may be used.

  Examples of the adhesive include water-based adhesives, that is, an adhesive component dissolved in water, or an adhesive component dispersed in water from the viewpoint of thinning the adhesive layer. For example, a composition using a polyvinyl alcohol-based resin or a urethane resin as a main component can be mentioned as a preferred adhesive.

  When a polyvinyl alcohol-based resin is used as the main component of the adhesive, the polyvinyl alcohol-based resin includes partially saponified polyvinyl alcohol and fully saponified polyvinyl alcohol, as well as carboxyl group-modified polyvinyl alcohol, acetoacetyl group-modified polyvinyl alcohol, and methylol group. Modified polyvinyl alcohol resins such as modified polyvinyl alcohol and amino group-modified polyvinyl alcohol may also be used. When a polyvinyl alcohol resin is used as the adhesive component, the adhesive is often prepared as an aqueous solution of a polyvinyl alcohol resin. The density | concentration of the polyvinyl alcohol-type resin in an adhesive agent is about 1-10 weight part normally with respect to 100 weight part of water, Preferably it is 1-5 weight part.

  In order to improve the adhesiveness, it is preferable to add a curable component such as glyoxal or a water-soluble epoxy resin or a crosslinking agent to the adhesive containing a polyvinyl alcohol resin as a main component. Examples of water-soluble epoxy resins include polyamide polyamines obtained by reacting a polyalkylene polyamine such as diethylenetriamine or triethylenetetramine with a dicarboxylic acid such as adipic acid and epichlorohydrin. An epoxy resin can be mentioned. Commercially available products of such polyamide polyamine epoxy resins include “Smiles Resin 650” and “Smiles Resin 675” sold by Sumika Chemtex Co., Ltd., and “WS-525” sold by Japan PMC Co., Ltd. Etc., and these can be preferably used. The addition amount of these curable components or crosslinking agents is usually 1 to 100 parts by weight, preferably 1 to 50 parts by weight with respect to 100 parts by weight of the polyvinyl alcohol resin. If the amount added is small, the effect of improving the adhesiveness is reduced, while if the amount added is large, the adhesive layer tends to be brittle.

  When a urethane resin is used as the main component of the adhesive, examples of suitable adhesive compositions include a mixture of a polyester ionomer type urethane resin and a compound having a glycidyloxy group. The polyester-based ionomer type urethane resin here is a urethane resin having a polyester skeleton, into which a small amount of an ionic component (hydrophilic component) is introduced. Such an ionomer-type urethane resin is suitable as a water-based adhesive because it is emulsified directly in water without using an emulsifier to form an emulsion. Polyester ionomer urethane resins are known per se. For example, Japanese Patent Application Laid-Open No. 7-97504 describes a polyester ionomer type urethane resin as an example of a polymer dispersant for dispersing a phenolic resin in an aqueous medium, and Japanese Patent Application Laid-Open No. 2005-070140. In JP-A-2005-181817, a cycloolefin resin film is bonded to a polarizing film made of a polyvinyl alcohol resin using a mixture of a polyester ionomer urethane resin and a compound having a glycidyloxy group as an adhesive. The form is shown.

  A photocurable adhesive can also be used as the adhesive. Examples of the photocurable adhesive include a mixture of a photocurable epoxy resin and a photocationic polymerization initiator. Examples of the photocurable epoxy resin include alicyclic epoxy resins, epoxy resins having no alicyclic structure, and mixtures thereof. Moreover, what added the radical polymerization type initiator and / or the cationic polymerization type initiator to epoxy resin, acrylic resin, okutacene resin, urethane resin, polyvinyl alcohol resin etc. as a photocurable adhesive agent can also be used.

  As a method of bonding the first acrylic resin film and / or the transparent film to the first polarizing film surface using an adhesive, a conventionally known method can be used. For example, a casting method, a Meyer may be used. An adhesive is applied to the adhesive surface of the first polarizing film and / or the film to be bonded thereto by the bar coating method, gravure coating method, comma coater method, doctor plate method, die coating method, dip coating method, spraying method, etc. The method of apply | coating and superimposing both is mentioned. The casting method is a method of spreading and spreading an adhesive on the surface of a film to be coated while moving it in a substantially vertical direction, a substantially horizontal direction, or an oblique direction between the two.

  After apply | coating an adhesive agent by the above methods, both are joined by pinching | interposing a 1st polarizing film and the film bonded to it by a nip roll. Moreover, after dripping an adhesive agent between the 1st polarizing film and the film bonded to it, the method of pressurizing this laminated body with a roll etc. and spreading it uniformly can also be used suitably. In this case, a metal, rubber, or the like can be used as the material of the roll. Furthermore, after dripping an adhesive agent between the 1st polarizing film and the film bonded to it, the method of passing this laminated body between rolls and pressurizing and spreading is also employ | adopted preferably. In this case, these rolls may be made of the same material or different materials.

  In addition, it is preferable that the thickness of the adhesive bond layer after bonding using the said nip roll etc. before drying or hardening is 5 micrometers or less, and it is preferable that it is 0.01 micrometers or more.

  In order to improve the adhesiveness, the surface of the first polarizing film and / or the film bonded thereto is a surface such as a plasma treatment, a corona treatment, an ultraviolet irradiation treatment, a flame (flame) treatment, or a saponification treatment. You may perform a process suitably. Examples of the saponification treatment include a method of immersing in an aqueous alkali solution such as sodium hydroxide or potassium hydroxide.

  The laminated body joined via the aqueous adhesive is usually subjected to a drying treatment, and the adhesive layer is dried and cured. The drying process can be performed by blowing hot air, for example. The drying temperature is appropriately selected from the range of about 40 to 100 ° C, preferably 60 to 100 ° C. The drying time is, for example, about 20 to 1,200 seconds. The thickness of the adhesive layer after drying is usually about 0.001 to 5 μm, preferably 0.01 μm or more, preferably 2 μm or less, more preferably 1 μm or less. If the thickness of the adhesive layer becomes too large, the appearance of the polarizing plate tends to be poor.

  After the drying treatment, sufficient adhesive strength may be obtained by performing curing at a temperature of room temperature or higher for at least half a day, usually 1 day or longer. Such curing is typically performed in a state of being wound in a roll. A preferable curing temperature is in the range of 30 to 50 ° C, more preferably 35 ° C or more and 45 ° C or less. When the curing temperature exceeds 50 ° C., so-called “roll tightening” is likely to occur in the roll winding state. The humidity during curing is not particularly limited, but is preferably selected so that the relative humidity is in the range of about 0% RH to 70% RH. The curing time is usually about 1 to 10 days, preferably about 2 to 7 days.

On the other hand, when joining a polarizing film and the film bonded to it using a photocurable adhesive, a photocurable adhesive is hardened by irradiating an active energy ray after joining. The light source of the active energy ray is not particularly limited, but an active energy ray having a light emission distribution at a wavelength of 400 nm or less is preferable. A microwave excited mercury lamp, a metal halide lamp, or the like is preferably used. The light irradiation intensity to the photocurable adhesive is appropriately determined depending on the composition of the photocurable adhesive and is not particularly limited, but the irradiation intensity in the wavelength region effective for activating the polymerization initiator is 0.1 to 6000 mW. / Cm ² is preferable. When the irradiation intensity is 0.1 mW / cm ² or more, the reaction time does not become too long, and when it is 6000 mW / cm ² or less, it is caused by heat radiated from the light source and heat generated during curing of the photocurable adhesive. There is little risk of yellowing of the epoxy resin and deterioration of the polarizing film. The light irradiation time to the photocurable adhesive is controlled for each photocurable adhesive to be cured and is not particularly limited, but the integrated light amount expressed as the product of the irradiation intensity and the irradiation time is It is preferably set to be 10 to 10,000 mJ / cm ² . When the cumulative amount of light to the photocurable adhesive is 10 mJ / cm ² or more, a sufficient amount of active species derived from the polymerization initiator can be generated to allow the curing reaction to proceed more reliably, and at 10,000 mJ / cm ² or less. In some cases, irradiation time does not become too long and good productivity can be maintained. The thickness of the adhesive layer after irradiation with active energy rays is usually about 0.001 to 5 μm, preferably 0.01 μm or more, preferably 2 μm or less, more preferably 1 μm or less.

  When the photocurable adhesive is cured by irradiation with active energy rays, the degree of polarization of the first polarizing film, the transmittance and the hue, and the first acrylic resin film, optical compensation film, protective film, and other transparent films It is preferable to perform the curing under the condition that various functions of the polarizing plate such as transparency are not deteriorated.

(Second polarizing plate)
The second polarizing plate is used as a front side (viewing side) polarizing plate of a liquid crystal panel, and has a haze value of 0.1% or more and 45% on one side of a second polarizing film made of a polyvinyl alcohol-based resin. It is produced by laminating antiglare films having the following ranges. Specifically, the second polarizing film is obtained by adsorbing and orienting a dichroic dye on a uniaxially stretched polyvinyl alcohol-based resin film, and the same description as the first polarizing film can be used in the same manner. it can. The first polarizing film and the second polarizing film may be the same or different with respect to the outer shape (thickness, etc.), material, and manufacturing method.

  The antiglare film can be produced by laminating a hard coat layer having a fine uneven shape on the surface of the second acrylic resin film as a base material. As the second acrylic resin film serving as the base material, those described for the first acrylic resin film can be used in the same manner. The acrylic resin films used for the first polarizing plate and the second polarizing plate may be the same or different with respect to the outer shape (thickness, etc.), material, composition, manufacturing method, and the like. By using the second acrylic resin film as a base material, it is possible to further improve the mechanical strength of the liquid crystal panel and to further reduce the thickness of the liquid crystal panel. Also, in the second polarizing plate, by using an acrylic resin film as a protective film, the protective film used for the first polarizing plate and the protective film used for the second polarizing plate are made of the same material. Therefore, warpage of the liquid crystal panel can be prevented. Thereby, even when applied to a thin liquid crystal display device, it is possible to prevent circular unevenness and Newton's ring due to contact between the liquid crystal panel and the backlight system.

  The haze value of the antiglare film is in the range of 0.1% to 45%. A haze value of 0.1% is synonymous with a substantially clear hard coat layer. If the haze value is higher than 45%, the screen becomes white and the visibility is lowered. The haze value of the antiglare film may be less than 10%, but is preferably 10% or more from the viewpoint of reducing reflection of a fluorescent lamp. Here, the haze value is measured by a method according to JIS K 7136.

  The thickness of the second acrylic resin film is preferably about 20 to 120 μm, and more preferably about 30 to 80 μm. When the thickness of the film is less than 20 μm, handling tends to be difficult, and when the thickness exceeds 120 μm, the merit of thinning tends to be reduced.

  The hard coat layer having the fine surface irregularity shape includes a method of forming a coating film containing organic fine particles or inorganic fine particles on the second acrylic resin film surface, and contains or does not contain organic fine particles or inorganic fine particles. Although it can manufacture by the method (for example, embossing method etc.) which presses against the roll which provided the uneven | corrugated shape after forming a coating film, it is not limited to these. Examples of the method for forming the coating film include a method in which a coating solution containing a binder component made of a curable resin composition and organic fine particles or inorganic fine particles is applied to the surface of the second acrylic resin film. be able to.

  Typical examples of inorganic fine particles include silica, colloidal silica, alumina, alumina sol, aluminosilicate, alumina-silica composite oxide, kaolin, talc, mica, calcium carbonate, calcium phosphate, and the like. As the organic fine particles, resin particles such as crosslinked polyacrylic acid particles, methyl methacrylate / styrene copolymer resin particles, crosslinked polystyrene particles, crosslinked polymethyl methacrylate particles, silicone resin particles, and polyimide particles can be used.

  The binder component for dispersing the inorganic fine particles or the organic fine particles is preferably selected from materials having high hardness (hard coat). As the binder component, an ultraviolet curable resin, a thermosetting resin, an electron beam curable resin, or the like can be used, and an ultraviolet curable resin is preferably used from the viewpoint of productivity, hardness, and the like. A commercially available product can be used as the ultraviolet curable resin. For example, one or more polyfunctional acrylates such as trimethylolpropane triacrylate and pentaerythritol tetraacrylate, and “Irgacure 907”, “Irgacure 184” (above, manufactured by Ciba Specialty Chemicals), “ A mixture with a photopolymerization initiator such as “Lucirin TPO” (manufactured by BASF) can be used as an ultraviolet curable resin. For example, when an ultraviolet curable resin is used, after dispersing inorganic fine particles or organic fine particles in the ultraviolet curable resin, the resin composition is applied onto the second acrylic resin film and irradiated with ultraviolet rays. Thus, a hard coat layer in which inorganic fine particles or organic fine particles are dispersed in a hard coat resin made of a binder resin can be formed.

  Examples of the ultraviolet curable resin include, in detail, a mixture of urethane acrylate, polyol (meth) acrylate, a (meth) acrylic polymer having an alkyl group containing two or more hydroxyl groups, and a photopolymerization initiator. it can.

  The urethane acrylate is preferably prepared using (meth) acrylic acid and / or (meth) acrylic ester, polyol, and diisocyanate. For example, urethane acrylate can be produced by preparing hydroxy (meth) acrylate having at least one hydroxyl group from (meth) acrylic acid and / or (meth) acrylic acid ester and polyol and reacting it with diisocyanate. it can. These (meth) acrylic acid and / or (meth) acrylic acid ester, polyol, and diisocyanate may be used singly or in combination of two or more. Moreover, you may add various additives according to the objective.

  Examples of the (meth) acrylic acid ester include alkyl (meth) acrylates such as methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, isopropyl (meth) acrylate, and butyl (meth) acrylate; cyclohexyl And cycloalkyl (meth) acrylates such as (meth) acrylates.

  The polyol is a compound having at least two hydroxyl groups, such as ethylene glycol, 1,3-propylene glycol, 1,2-propylene glycol, diethylene glycol, dipropylene glycol, neopentyl glycol, 1,3-butanediol, 1,4-butanediol, 1,6-hexanediol, 1,9-nonanediol, 1,10-decane glycol, 2,2,4-trimethyl-1,3-pentanediol, 3-methyl-1,5 -Pentanediol, hydroxypivalic acid neopentyl glycol ester, cyclohexanedimethylol, 1,4-cyclohexanediol, spiroglycol, tricyclodecanemethylol, hydrogenated bisphenol A, ethylene oxide-added bisphenol A, propylene glycol Side addition bisphenol A, trimethylolethane, trimethylolpropane dimethylol propane, glycerin, 3-methylpentane-1,3,5-triol, pentaerythritol, can be exemplified dipentaerythritol, tripentaerythritol, glucose ethers.

  As said diisocyanate, various aromatic, aliphatic, or alicyclic diisocyanates can be used, for example. Specific examples include tetramethylene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, 2,4-tolylene diisocyanate, 4,4-diphenyl diisocyanate, 1,5-naphthalene diisocyanate, 3,3-dimethyl-4,4-diphenyl diisocyanate. , Xylene diisocyanate, trimethylhexamethylene diisocyanate, 4,4-diphenylmethane diisocyanate, and hydrogenated products thereof.

  Specific examples of the polyol (meth) acrylate include pentaerythritol di (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol hexa (meth) acrylate, and 1,6-hexane. Diol (meth) acrylate is mentioned. These components may be used alone or in combination. Furthermore, you may add various additives as needed. The polyol (meth) acrylate preferably comprises pentaerythritol triacrylate and pentaerythritol tetraacrylate. These may be a copolymer or a mixture.

  Examples of the (meth) acrylic polymer having an alkyl group containing two or more hydroxyl groups include a (meth) acrylic polymer having a 2,3-dihydroxypropyl group, a 2-hydroxyethyl group, and a 2,3-dihydroxypropyl group. (Meth) acrylic polymer having

  As photopolymerization initiators, 2,2-dimethoxy-2-phenylacetophenone, acetophenone, benzophenone, xanthone, 3-methylacetophenone, 4-chlorobenzophenone, 4,4′-dimethoxybenzophenone, benzoinpropyl ether, benzyldimethyl ketal, List N, N, N ′, N′-tetramethyl-4,4′-diaminobenzophenone, 1- (4-isopropylphenyl) -2-hydroxy-2-methylpropan-1-one, and other thioxanthates. Can do.

  A solvent is added to the mixture as necessary. Although it does not restrict | limit especially as a solvent, For example, ethyl acetate, butyl acetate, and these mixed solvents can be mentioned.

  Moreover, the said mixture may contain a leveling agent, for example, can mention a fluorine type or a silicone type leveling agent. Examples of the silicone leveling agent include reactive silicone, polydimethylsiloxane, polyether-modified polydimethylsiloxane, and polymethylalkylsiloxane. Preferred are reactive silicone and siloxane leveling agents. By using a reactive silicone leveling agent, the surface of the hard coat layer is provided with slipperiness, and excellent scratch resistance can be maintained for a long period of time. In addition, when a siloxane leveling agent is used, film formability can be improved.

Examples of the leveling agent for reactive silicone include those having a siloxane bond, and an acrylate group and a hydroxyl group. As a specific example,
(A) (dimethylsiloxane): (3-acryloyl-2-hydroxypropoxypropylsiloxane): (2-acryloyl-3-hydroxypropoxypropylsiloxane) = 0.8: 0.16: 0.04 (molar ratio) Copolymer,
(B) (dimethylsiloxane) :( hydroxypropylsiloxane) :( 6-isocyanatohexylisocyanuric acid) :( aliphatic polyester) = 6.3: 1.0: 2.2: 1.0 (molar ratio) Polymer,
(C) (Dimethylsiloxane): (Methyl polyethylene glycol propyl ether siloxane having an acrylate terminal): (Methyl polyethylene glycol propyl ether siloxane having a hydroxyl group at the terminal) = 0.88: 0.07: 0.05 (molar ratio) And the like.

  As described above, by using the acrylic binder component (binder resin) as exemplified, the adhesion with the second acrylic resin film is improved, the mechanical strength is further improved, and the surface is more scratched. An antiglare film that can be effectively prevented can be obtained.

  In the case of forming a hard coat layer having a fine uneven surface shape by an embossing method, a hard die formed on the second acrylic resin film is formed using a mold having a fine uneven shape. What is necessary is just to transfer to a coat layer. The transfer to the mold-shaped hard coat layer is preferably performed by embossing, and UV embossing using an ultraviolet curable resin is preferable as embossing. In addition, when forming fine surface uneven | corrugated shape by the embossing method, the hard-coat layer may contain the inorganic or organic fine particle, and does not need to contain it.

  In the UV embossing method, an ultraviolet curable resin layer is formed on the surface of the second acrylic resin film, and the ultraviolet curable resin layer is cured while being pressed against the uneven surface of the mold, so that the uneven surface of the mold is formed. Transferred to the ultraviolet curable resin layer. Specifically, the second acrylic resin film is applied in a state where an ultraviolet curable resin is applied onto the second acrylic resin film, and the applied ultraviolet curable resin is in close contact with the uneven surface of the mold. The shape of the mold is obtained by irradiating ultraviolet rays from the side to cure the ultraviolet curable resin, and then peeling the second acrylic resin film on which the cured ultraviolet curable resin layer is formed from the mold. Is transferred to an ultraviolet curable resin. The kind in particular of ultraviolet curable resin is not restrict | limited, For example, what was mentioned above can be used. Further, instead of the ultraviolet curable resin, a visible light curable resin that can be cured with visible light having a wavelength longer than that of ultraviolet light may be used by appropriately selecting a photoinitiator.

  Although the thickness of a hard-coat layer is not specifically limited, It is preferable that they are 2 micrometers or more and 30 micrometers or less, More preferably, they are 3 micrometers or more and 30 micrometers or less. When the thickness of the hard coat layer is less than 2 μm, sufficient hardness cannot be obtained, and the surface tends to be easily damaged. When the thickness is greater than 30 μm, the hard coat layer is easily broken and is prevented by hardening shrinkage of the hard coat layer. There is a tendency that the dazzling film curls and the productivity decreases.

  As described above, the antiglare film is preferably provided with haze by the hard coat layer, but with the formation of the hard coat layer, inorganic or organic fine particles are added to the second acrylic resin film as the base material. You may give a haze by making it disperse | distribute. Further, as the antiglare film, it is possible to use an acrylic resin film having no hard coat layer and having inorganic or organic fine particles dispersed therein. In these cases, the above-mentioned inorganic or organic fine particles can be used. Moreover, the thickness of the acrylic resin film in which inorganic or organic fine particles are dispersed is preferably about 20 to 120 μm, more preferably about 30 to 80 μm, as described above.

  In the antiglare film, a surface treatment such as an antistatic treatment is performed on the surface opposite to the surface to be attached to the second polarizing film (on the acrylic resin film or the hard coat layer). May be. In addition, a coat layer made of a liquid crystalline compound or a high molecular weight compound thereof may be formed.

  In the second polarizing plate, an adhesive or a pressure-sensitive adhesive for bonding the liquid crystal cell and the polarizing plate to the surface of the second polarizing film opposite to the surface on which the antiglare film is bonded. An agent layer may be formed. In addition, a transparent film such as a protective film or an optical compensation film is laminated on the surface of the second polarizing film opposite to the surface on which the antiglare film is bonded, and adhered onto the transparent film. An agent or pressure-sensitive adhesive layer may be formed. Examples of the transparent film include a cellulose film such as a triacetyl cellulose film (TAC film), an olefin film, an acrylic film, and a polyester film. Furthermore, an optical functional film can be laminated on the transparent film, and an adhesive or pressure-sensitive adhesive layer can be formed on the optical functional film. As the protective film, the optical compensation film, and the optical functional film, those described for the first polarizing plate can be similarly used.

  As a method for laminating a transparent film as an antiglare film and / or a protective film or an optical compensation film on the second polarizing film, the method described for the first polarizing plate can be similarly employed. When an adhesive is used on both sides of the second polarizing film, the same type of adhesive on both sides may be used, or a different type of adhesive may be used. Moreover, the adhesive agent used for preparation of the 1st polarizing plate and the adhesive agent used for preparation of the 2nd polarizing plate may be the same, or may differ.

<Liquid crystal panel and liquid crystal display device>
The liquid crystal panel of the present invention is a liquid crystal panel using the set of polarizing plates. Specifically, the first polarizing plate, the liquid crystal cell, and the second polarizing plate are arranged in this order. . Here, the first polarizing plate is disposed so that the surface of the first polarizing film opposite to the surface on which the first acrylic resin film is laminated faces the liquid crystal cell, and the second polarizing film The plate is disposed such that the surface opposite to the surface on which the antiglare film of the second polarizing film is laminated faces the liquid crystal cell. That is, the first polarizing plate is affixed to the liquid crystal cell using an adhesive or an adhesive with the surface opposite to the surface of the first polarizing film on which the first acrylic resin film is laminated as the adhesive surface. Or a transparent film as a protective film or an optical compensation film laminated on the surface opposite to the surface on which the first acrylic resin film is laminated in the first polarizing film, or further laminated thereon It is affixed to a liquid crystal cell through the optical functional film made. Similarly, the second polarizing plate is attached to the liquid crystal cell using an adhesive or a pressure-sensitive adhesive with the surface opposite to the surface on which the antiglare film is laminated in the second polarizing film as an adhesive surface. Or a transparent film as a protective film or an optical compensation film laminated on the surface opposite to the surface on which the antiglare film is laminated in the second polarizing film, or optical functionality laminated thereon. Affixed to the liquid crystal cell through a film.

  As the liquid crystal cell, a conventionally known configuration can be adopted. For example, various types of liquid crystal cells such as a twisted nematic (TN) mode and a vertical alignment (VA) mode can be used.

  The liquid crystal panel using the set of polarizing plates of the present invention uses an acrylic resin film as a protective film for the first polarizing plate, and an antiglare film based on the acrylic resin film as the second polarizing plate. Since it is used as a protective film, improvement in mechanical strength and thinning, prevention of scratches on the surface, improvement in visibility, and prevention of warping are realized.

  FIG. 1 is a schematic cross-sectional view showing an example of a basic layer configuration of the liquid crystal display device of the present invention. The liquid crystal display device shown in FIG. 1 includes a backlight 10, a light diffusion plate 50, a liquid crystal cell 40, and a first polarizing plate 20 as a back side polarizing plate attached to one surface of the liquid crystal cell 40. A liquid crystal panel composed of a second polarizing plate 30 as a front side polarizing plate attached to the other surface of the liquid crystal cell 40 is arranged in this order. The first polarizing plate 20 has a configuration in which the first polarizing film 21 is sandwiched between the optical compensation film 23 and the first acrylic resin film 25, and the optical compensation film 23 is placed in the liquid crystal cell 40. It arrange | positions so that it may oppose. The second polarizing plate 30 has a configuration in which the second polarizing film 31 is sandwiched between the optical compensation film 33 and the antiglare film 34, and the optical compensation film 33 faces the liquid crystal cell 40. Are arranged to be. In this example, the antiglare film 34 is composed of a second acrylic resin film 35 and a hard coat layer 36 having a fine uneven shape on the surface laminated thereon. In the liquid crystal display device of the present invention shown in FIG. 1, the liquid crystal panel is arranged so that the first polarizing plate 20 that is the back side polarizing plate is on the backlight side, that is, the first acrylic resin film 25 is light. It arrange | positions so that the diffusion plate 50 may be opposed.

  Here, the light diffusing plate 50 is an optical member having a function of diffusing light from the backlight 10, and for example, a light diffusing agent is provided by dispersing particles as a light diffusing agent in a thermoplastic resin. In addition, the surface of the thermoplastic resin plate formed with irregularities to impart light diffusibility, the surface of the thermoplastic resin plate provided with a resin composition coating layer in which particles are dispersed, and the like provided with light diffusibility, etc. It can be. The thickness can be about 0.1-5 mm. Further, between the light diffusion plate 50 and the liquid crystal panel, a prism sheet (also called a light condensing sheet, for example, “BEF” manufactured by 3M, etc.), a brightness enhancement sheet (the reflection type described above) A sheet exhibiting other optical functionalities, such as a light diffusion sheet, which is the same as the polarizing film (DBEF, APF)) can also be disposed. One or more sheets of other optical functionalities can be arranged as required. Further, as the light diffusion plate 50, for example, a light diffusion plate such as a laminated integrated product of a prism sheet having a cylindrical shape on the surface and a light diffusion plate (for example, one described in Japanese Patent Application Laid-Open No. 2006-284597). It is also possible to use an optical sheet in which other functions are combined with each other.

  Such a liquid crystal display device of the present invention uses the liquid crystal panel of the present invention. Like the liquid crystal panel, the mechanical strength is improved and the warpage of the panel is improved. The liquid crystal display device of the present invention is not limited to the configuration shown in FIG. 1, and various modifications can be made. For example, as described above, the optical compensation film 23 and / or the optical compensation film 33 are not necessarily required and may be omitted. A protective film may be used instead of the optical compensation film 23 and / or the optical compensation film 33.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited by these examples. In the examples, “%” and “part” representing the content or amount used are based on weight unless otherwise specified.

[Production Example 1] Production of polarizing film A polyvinyl alcohol film having an average polymerization degree of about 2,400 and a saponification degree of 99.9 mol% or more and a thickness of 75 µm was immersed in pure water at 30 ° C, and then iodine / iodination. It was immersed at 30 ° C. in an aqueous solution having a weight ratio of potassium / water of 0.02 / 2/100. Then, it was immersed at 56.5 ° C. in an aqueous solution having a potassium iodide / boric acid / water weight ratio of 12/5/100. Subsequently, after washing with pure water at 8 ° C., it was dried at 65 ° C. to obtain a polarizing film in which iodine was adsorbed and oriented on polyvinyl alcohol. Stretching was mainly performed in the iodine staining and boric acid treatment steps, and the total stretching ratio was 5.3 times.

[Production Example 2] Production of acrylic resin film 70 parts of a copolymer of methyl methacrylate / methyl acrylate = 96/4 (weight ratio) and acrylic rubber particles (acrylic multilayer polymer having a three-layer structure) First layer: Copolymer of methyl methacrylate and allyl methacrylate (weight ratio 99.8 / 0.2) / Second layer: Copolymer of butyl acrylate, styrene and allyl methacrylate (weight ratio 79/19/2) / Third layer: An acrylic resin film having a thickness of 80 μm was prepared by melt extrusion from a mixture of 30 parts of a copolymer of methyl acrylate and ethyl acrylate (weight ratio 96/4).

[Production Example 3] Preparation of anti-glare film (A) Pentaerythritol triacrylate and polyfunctional urethanized acrylate (reaction product of hexamethylene diisocyanate and pentaerythritol triacrylate) in a weight ratio of 60/40, ethyl acetate An ultraviolet curable resin composition containing a leveling agent and dissolved in a solid concentration of 60% was used. This ultraviolet curable resin composition exhibits a refractive index of 1.53 after curing.

  Into the ultraviolet curable resin composition, methyl methacrylate / styrene copolymer resin particles having a weight average particle diameter of 2.7 μm and a refractive index of 1.57 are added to 100 parts of the ultraviolet curable resin (binder component). After 5 parts were added and dispersed, ethyl acetate was added so that the concentration of solids (including resin particles) was 30% to prepare a coating solution.

On the acrylic resin film of Production Example 2, the coating solution was applied so that the coating thickness after drying was 3.4 μm, and dried for 3 minutes in a dryer set at 60 ° C. The UV-curable resin composition layer is irradiated with light from a high-pressure mercury lamp with an intensity of 20 mW / cm ² from the side of the UV-curable resin composition layer of the dried film so that the amount of light in terms of h-line is 200 mJ / cm ^2. Was cured to obtain an antiglare film (A) comprising an acrylic resin film having a hard coat layer (thickness: 3.4 μm) having irregularities on the surface.

  The haze value of the antiglare film (A) was measured by using a haze meter “HM-150” manufactured by Murakami Color Research Laboratory in accordance with JIS K 7136, and found to be 20.1%. . In measuring the haze, in order to prevent warping of the antiglare film (A), an optically transparent adhesive is used so that the uneven surface becomes the surface of the antiglare film (A). The acrylic resin film was bonded to a glass substrate and then used for measurement.

<Example 1>
(A) Preparation of back side polarizing plate After applying the corona treatment to the bonding surface of the acrylic resin film (thickness 80 μm) obtained in Production Example 2 on one side of the polarizing film obtained in Production Example 1 And bonded through an adhesive. On the opposite surface of the polarizing film, an optical compensation film (thickness 68 μm, in-plane retardation value 63 nm, thickness direction retardation value 225 nm) made of a biaxially stretched norbornene-based resin was subjected to corona treatment on the bonding surface. Then, it bonded through the adhesive agent and obtained the back side polarizing plate. In addition, the optical compensation film made of the biaxially stretched norbornene resin was bonded so that the slow axis thereof was orthogonal to the stretch axis of the polarizing film. Next, a layer of an adhesive (thickness: 25 μm) was provided on the biaxially stretched norbornene-based optical compensation film surface of the back side polarizing plate.

(B) Preparation of front-side polarizing plate The antiglare film (A) obtained in Production Example 3 is bonded to one side of the polarizing film obtained in Production Example 1 via an adhesive, and the polarizing film On the opposite surface, a saponified triacetyl cellulose film (thickness 80 μm, in-plane retardation value 3 nm, thickness direction retardation value 50 nm) is bonded via an adhesive, and the front side polarizing plate is attached. Obtained. A layer of adhesive (thickness 25 μm) was provided on the triacetyl cellulose film surface of the front side polarizing plate.

(C) Production of liquid crystal panel and liquid crystal display device The polarizing plates on both sides were peeled off from the liquid crystal cell of a commercially available liquid crystal television ("LC-42GX1W" manufactured by Sharp Corporation) equipped with a liquid crystal display element of vertical alignment mode. The liquid crystal cell has the back side polarizing plate on the back side (backlight side), the liquid crystal cell has the front side polarizing plate on the front side (viewing side), and the absorption axis of the polarizing plate is originally a liquid crystal television. A liquid crystal panel was produced by pasting together through an adhesive layer formed on the optical compensation film so as to coincide with the absorption axis direction of the polarizing plate attached to the film. Next, this liquid crystal panel was assembled in a configuration of backlight / light diffusion plate / diffusion sheet / diffusion sheet / brightness enhancement sheet (“DBEF” manufactured by 3M) / liquid crystal panel to produce a liquid crystal display device. In the liquid crystal display device, since the warpage of the liquid crystal panel is prevented, contact with the brightness enhancement sheet due to this can be avoided, and color unevenness can be prevented. Moreover, the front surface side polarizing plate surface (hard coat layer surface) of a liquid crystal panel is hardly damaged.

<Comparative Example 1>
The front side polarizing plate was prepared in the same manner as in Example 1 except that the acrylic resin film of Production Example 2 having no hard coat layer was used instead of the antiglare film (A) in the production of the front side polarizing plate. A plate was produced and a liquid crystal display device was assembled. When the surface of the front side polarizing plate (acrylic resin film surface) of the liquid crystal panel was rubbed with a cloth, it was easily scratched.

  It should be understood that the embodiments and examples disclosed herein are illustrative and non-restrictive in every respect. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

It is a schematic sectional drawing which shows an example of the fundamental layer structure of the liquid crystal display device of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 Backlight, 20 1st polarizing plate, 21 1st polarizing film, 23, 33 Optical compensation film, 25 1st acrylic resin film, 30 2nd polarizing plate, 31 2nd polarizing film, 34 Prevention Dazzle film, 35 second acrylic resin film, 36 hard coat layer, 40 liquid crystal cell, 50 light diffusion plate.

Claims (6)

A set of polarizing plates for a liquid crystal panel comprising a first polarizing plate and a second polarizing plate,
The first polarizing plate has a first polarizing film made of a polyvinyl alcohol-based resin, and a first acrylic resin film laminated on one side of the first polarizing film,
The second polarizing plate includes at least a second polarizing film made of a polyvinyl alcohol-based resin and a second acrylic resin film laminated on one surface of the second polarizing film, and has a haze value of 0. A set of polarizing plates having an antiglare film in a range of 1% to 45%.   The said 1st polarizing plate further has the optical compensation film or protective film laminated | stacked on the surface on the opposite side to the surface where the said 1st acrylic resin film was laminated | stacked in the said 1st polarizing film. A set of polarizing plates as described in 1.   The said 2nd polarizing plate further has the optical compensation film or protective film laminated | stacked on the surface on the opposite side to the surface where the said anti-glare film in the said 2nd polarizing film was laminated | stacked. A set of the polarizing plates described. A liquid crystal panel using the set of polarizing plates according to claim 1,
The first polarizing plate, the liquid crystal cell, and the second polarizing plate are arranged in this order,
The first polarizing plate is disposed such that a surface of the first polarizing film opposite to the surface on which the first acrylic resin film is laminated is opposed to the liquid crystal cell, and
The second polarizing plate is a liquid crystal panel arranged such that a surface of the second polarizing film opposite to the surface on which the antiglare film is laminated faces the liquid crystal cell. A backlight, a light diffusion plate, and the liquid crystal panel according to claim 4 are provided in this order,
The liquid crystal panel is a liquid crystal display device in which the first polarizing plate is disposed so as to face the light diffusion plate. A backlight, a light diffusing plate, a brightness enhancement sheet and the liquid crystal panel according to claim 4 are provided in this order,
The liquid crystal panel is a liquid crystal display device in which the first polarizing plate is disposed so as to face the brightness enhancement sheet.

Images