JP2009157348A - Polarizing plate and liquid crystal display using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a polarizing plate coping with a thinner liquid crystal panel to which the polarizing plate is applied, and being capable of reinforcing the panel, preventing the liquid crystal panel, to which the polarizing plate is applied from being in contact with a backlight system, and to provide a liquid crystal display device that uses the polarizing plate. <P>SOLUTION: The polarizing plate comprises a polarizing film, made of a polyvinylalcohol system resin, and a biaxially oriented polyethylene terephthalate film layered with an adhesive layer on one side of the polarizing film. The polarizing plate further includes a pressure-sensitive adhesive layer on the outer face, in the opposite face of the polarizing film to the face where the biaxially oriented polyethylene terephthalate film is layered. A liquid crystal display device having a liquid crystal panel is disclosed, in which the polarizing plate is stuck to a liquid crystal cell via the pressure-sensitive adhesive layer. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a polarizing plate in which a biaxially stretched polyethylene terephthalate film is laminated on one side of a polarizing film made of polyvinyl alcohol resin via an adhesive layer, and a liquid crystal display device using the polarizing plate.

  A polarizing plate is usually a protective film (for example, cellulose acetate represented by triacetyl cellulose) through an adhesive layer on one side or both sides of a polarizing film made of a polyvinyl alcohol-based resin to which a dichroic dye is adsorbed and oriented. System protective film). A polarizing plate having such a laminated structure is bonded to a liquid crystal cell with an adhesive via another optical film as necessary, and is used as a component of a liquid crystal display device.

  Applications of liquid crystal display devices are rapidly expanding as thin display devices 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 high. A polarizing plate for a liquid crystal television is usually formed by laminating a triacetyl cellulose film (TAC film) with a water-based adhesive on both sides of a polarizing film made of a polyvinyl alcohol resin to which a dichroic dye is adsorbed and oriented. A retardation film is laminated on the outer surface of one side of the plate via an adhesive.

  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. The laminated product of such a polarizing plate and a retardation film made of a cycloolefin resin film reduces the number of components or simplifies the manufacturing process in order to improve productivity and reduce product cost. For example, JP-A-8-43812 (Patent Document 1) discloses a laminated structure of a cycloolefin-based (norbornene-based) resin film / polarizing film / TAC film having a retardation function. Yes.

JP-A-2005-70140 (Patent Document 2), JP-A-2005-181817 (Patent Document 3) and JP-A-2005-208456 (Patent Document 4) describe polarized light made of a polyvinyl alcohol resin. It is described that a film and a cycloolefin-based protective film are bonded with a urethane-based aqueous adhesive.
JP-A-8-43812 JP-A-2005-70140 JP 2005-181817 A JP-A-2005-208456

  In the use of large-screen liquid crystal televisions, the needs for wall-mounted televisions are becoming thinner, and in this case, the following points are problems as components used for liquid crystal panels.

(1) It is necessary to reinforce the strength of the panel in response to the thin and large screen of the liquid crystal panel.
(2) It is necessary to reduce the thickness of members used in response to the reduction in the thickness of liquid crystal televisions.
(3) The 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.

  The present invention has been made in order to solve the above-described problems, and the object of the present invention is to reinforce the liquid crystal panel while reducing the thickness of the applied liquid crystal panel. A polarizing plate capable of preventing contact between a liquid crystal panel and a backlight system, and a liquid crystal display device using the same are provided.

  As a result of earnest research to solve such problems, the present inventors have a structure in which a biaxially stretched polyethylene terephthalate film is laminated on one side of a polarizing film made of a polyvinyl alcohol resin via an adhesive layer. Thus, the present inventors have found that a polarizing plate having excellent mechanical strength, particularly tearability, and excellent visibility can be obtained even if it is thin, and the present invention has been completed. That is, the present invention is as follows.

  The polarizing plate of the present invention comprises a polarizing film made of a polyvinyl alcohol-based resin and a biaxially stretched polyethylene terephthalate film laminated on one side of the polarizing film via an adhesive layer.

  The polarizing plate of the present invention preferably further has an antiglare layer laminated on the surface opposite to the side on which the polarizing film of the biaxially stretched polyethylene terephthalate film is laminated.

  The polarizing plate of the present invention preferably further has a protective film or an optical compensation film laminated on the side opposite to the side on which the biaxially stretched polyethylene terephthalate film of the polarizing film is laminated.

  The polarizing plate of the present invention preferably further has an adhesive layer on the outer surface of the polarizing film opposite to the side on which the biaxially stretched polyethylene terephthalate film is laminated.

  The present invention also provides a liquid crystal display device including a liquid crystal panel in which the polarizing plate of the present invention having the above-described pressure-sensitive adhesive layer is bonded to a liquid crystal cell via the pressure-sensitive adhesive layer.

  The polarizing plate of the present invention is excellent in mechanical strength, particularly tearability, and can achieve improvement and thinning of the mechanical strength of the applied liquid crystal panel, and further contact between the liquid crystal panel using this and the backlight system. Can be prevented. The liquid crystal display device of the present invention using such a polarizing plate of the present invention can be suitably applied to a liquid crystal display device for a large-screen liquid crystal television, particularly a liquid crystal display device for a liquid crystal television that can be wall-mounted.

  Specifically, the polarizing film used in the polarizing plate of the present invention is obtained by adsorbing and orienting a dichroic dye on a uniaxially stretched polyvinyl alcohol resin film. The polyvinyl alcohol-based resin can be obtained by saponifying a polyvinyl acetate-based resin. As the polyvinyl acetate resin, in addition to polyvinyl acetate which is a homopolymer of vinyl acetate, copolymers of vinyl acetate and other monomers copolymerizable therewith, such as ethylene-vinyl acetate copolymer, etc. Is mentioned. 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 85 to 100 mol%, preferably 98 mol% or more. These polyvinyl alcohol resins may be modified. For example, polyvinyl formal, polyvinyl acetal, polyvinyl butyral and the like modified with aldehydes may be used. Moreover, the polymerization degree of polyvinyl alcohol-type resin is in the range of 1000-10000 normally, Preferably it exists in the range of 1500-5000.

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

  The polarizing film is usually a process of dyeing a polyvinyl alcohol resin film with a dichroic dye to adsorb the dichroic dye (dyeing process), and a polyvinyl alcohol resin film adsorbed with the dichroic dye is boric acid. It is manufactured through a step of treating with an aqueous solution (boric acid treatment step) and a step of washing with water after the treatment with the boric acid aqueous solution (water washing treatment step).

  In the production of the polarizing film, the polyvinyl alcohol-based resin film is usually uniaxially stretched, but this uniaxial stretching may be performed before the dyeing treatment step or during the dyeing treatment step, It may be performed after the dyeing process. When uniaxial stretching is performed after the dyeing treatment step, the uniaxial stretching may be performed before the boric acid treatment step or during the boric acid treatment step. Of course, uniaxial stretching can be performed in these plural stages. Uniaxial stretching may be performed uniaxially between rolls having different peripheral speeds, or may be performed uniaxially using a hot roll. Moreover, the dry-type extending | stretching which extends | stretches in air | atmosphere may be sufficient, and the wet extending | stretching which extends | stretches in the state swollen with the solvent may be sufficient. The draw ratio is usually about 3 to 8 times.

  Dyeing of the polyvinyl alcohol resin film with the dichroic dye in the dyeing process is performed, for example, by immersing the polyvinyl alcohol resin film in an aqueous solution containing the dichroic dye. As the dichroic dye, for example, iodine, a dichroic dye or the like is used. Examples of dichroic dyes include C.I. I. Dichroic direct dyes composed of disazo compounds such as DIRECT RED 39 and dichroic direct dyes composed of compounds such as trisazo and tetrakisazo are included. In addition, it is preferable that the polyvinyl alcohol-type resin film performs the immersion process to water before a 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 0.01 to 1 part by weight per 100 parts by weight of water, and the content of potassium iodide is usually 0.5 to 20 parts by weight per 100 parts by weight of water. When iodine is used as the dichroic dye, the temperature of the aqueous solution used for dyeing is usually 20 to 40 ° C., and the immersion time (dyeing time) in this aqueous solution is usually 20 to 1800 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 an aqueous dichroic dye is usually employed. The content of the dichroic dye in this aqueous solution, usually, 1 × 10 ^-4 to 10 parts by weight per 100 parts by weight of water, preferably 1 × 10 ^-3 to 1 parts by weight, particularly preferably 1 × 10 ^{- 3} to 1 × 10 ⁻² parts by weight. This aqueous solution may contain an inorganic salt such as sodium sulfate as a dyeing assistant. When a dichroic dye is used as the dichroic dye, the temperature of the dye aqueous solution used for dyeing is usually 20 to 80 ° C., and the immersion time (dyeing time) in this aqueous solution is usually 10 to 1800 seconds. is there.

  The boric acid treatment step is performed by immersing a polyvinyl alcohol-based resin film dyed with a dichroic dye in a boric acid-containing aqueous solution. The amount of boric acid in the boric acid-containing aqueous solution is usually 2 to 15 parts by weight, preferably 5 to 12 parts by weight per 100 parts by weight of water. When iodine is used as the dichroic dye in the dyeing process described above, the boric acid-containing aqueous solution used in this boric acid treatment process preferably contains potassium iodide. In this case, the amount of potassium iodide in the boric acid-containing aqueous solution is usually 0.1 to 15 parts by weight, preferably 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 60 to 1200 seconds, preferably 150 to 600 seconds, and more preferably 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.

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

  In this way, the polyvinyl alcohol resin film is uniaxially stretched, dyed with a dichroic dye, treated with boric acid and washed with water to obtain a polarizing film. The thickness of this polarizing film is usually in the range of 5 to 40 μm. The polarizing plate of the present invention has a structure in which a biaxially stretched polyethylene terephthalate film is laminated on one side of such a polarizing film via an adhesive layer.

  The biaxially stretched polyethylene terephthalate film used in the present invention is a film excellent in mechanical properties, solvent resistance, scratch resistance, cost, etc., and the polarized light of the present invention using such a biaxially stretched polyethylene terephthalate film. The plate is excellent in mechanical strength and can be reduced in thickness.

  Here, polyethylene terephthalate is a resin in which 80 mol% or more of repeating units are composed of ethylene terephthalate. Other copolymer components include isophthalic acid, p-β-oxyethoxybenzoic acid, 4,4′-dicarboxydiphenyl, 4,4′-dicarboxybenzophenone, bis (4-carboxyphenyl) ethane, adipic acid , Dicarboxylic acid components such as sebacic acid, 5-sodium sulfoisophthalic acid, 1,4-dicarboxycyclohexane, such as propylene glycol, butanediol, neopentyl glycol, diethylene glycol, cyclohexanediol, bisphenol A ethylene oxide adduct, polyethylene glycol And diol components such as polypropylene glycol and polytetramethylene glycol. These dicarboxylic acid components and glycol components can be used in combination of two or more if necessary. It is also possible to use an oxycarboxylic acid such as p-oxybenzoic acid in combination with the dicarboxylic acid component or glycol component. Such other copolymerization component may contain a dicarboxylic acid component and / or a diol component containing a small amount of amide bond, urethane bond, ether bond, carbonate bond and the like.

  Polyethylene terephthalate is produced by a so-called direct polymerization method in which terephthalic acid and ethylene glycol (and other dicarboxylic acids and / or other diols if necessary) are directly reacted, dimethyl ester of terephthalic acid and ethylene glycol (and If necessary, any production method such as a so-called transesterification reaction in which a dimethyl ester of another dicarboxylic acid and / or another diol) is transesterified can be applied.

  Moreover, you may make a polyethylene terephthalate contain a well-known additive as needed. However, since transparency is required in optical applications, it is preferable to keep the additive amount to a minimum. Known additives include, for example, lubricants, antiblocking agents, heat stabilizers, antioxidants, antistatic agents, light resistance agents, impact resistance improvers and the like. Examples of the light absorber include an ultraviolet absorber. For example, 2,2′-methylenebis [4- (1,1,3,3-tetramethylbutyl) -6- (2H-benzo Triazol-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 Benzotriazole UV absorbers such as 5-di-tert-amyl-2-hydroxyphenyl) -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-methoxy 2-hydroxybenzophenone UV absorbers such as benzophenone and 2,2′-dihydroxy-4,4′-dimethoxybenzophenone; phenyl salicylates such as p-tert-butylphenylsalicylate and p-octylphenylsalicylate It includes such ester-based ultraviolet absorbers may be used two or more thereof as needed. When an ultraviolet absorber is included, the amount is usually 0.1% by weight or more, preferably 0.3% by weight or more, and preferably 2% by weight or less.

  The biaxially stretched polyethylene terephthalate film used in the present invention can be produced by forming the raw material resin as described above into a film shape and subjecting it to a biaxial stretching process. The production method of the biaxially stretched polyethylene terephthalate film is arbitrary and is not particularly limited. However, the non-oriented film obtained by melting the raw material resin and extruded into a sheet shape is used as the glass transition temperature of polyethylene terephthalate. A method of performing a heat setting treatment after mechanical stretching at the above temperature can be mentioned. Biaxial stretching may be simultaneous biaxial stretching or sequential biaxial stretching, but sequential biaxial stretching is preferred.

  Although the temperature at the time of extending | stretching will not be restrict | limited especially if it is the temperature more than the glass transition temperature of a polyethylene terephthalate, It is preferable to exist in the range of 80-130 degreeC, and it is more preferable to be in the range of 90-120 degreeC. preferable.

  In addition, the draw ratio of the biaxially stretched polyethylene terephthalate film in the present invention is preferably 2.5 to 6 times, and more preferably 3 to 5.5 times. This is because when the draw ratio is less than 2.5, the biaxially stretched polyethylene terephthalate film tends not to exhibit sufficient transparency. For example, a biaxially stretched polyethylene terephthalate film is produced by a two-stage stretching method, for example, by stretching 1.1-6 times in the film longitudinal direction (film running direction) and then stretching 2.5-6 times in the film width direction. You may do it.

  In addition, from the viewpoint of reducing the distortion of the orientation main axis in the biaxially stretched polyethylene terephthalate film (deviation from the stretch axis), the film is stretched in the longitudinal direction (the running direction of the film) after the stretching and before the heat setting treatment. ), Relaxation treatment in the width direction of the film (direction perpendicular to the running direction of the film) is preferable. The temperature for the relaxation treatment is 90 to 200 ° C, preferably 120 to 180 ° C. Although the relaxation amount varies depending on the transverse stretching conditions, it is preferable to set the relaxation amount and the temperature so that the heat shrinkage rate at 150 ° C. of the biaxially stretched polyethylene terephthalate film after the relaxation treatment is 2% or less.

  The temperature of the heat setting treatment is usually 180 to 250 ° C, preferably 200 to 245 ° C. In the heat setting treatment, first, after performing the heat setting treatment at a constant length, the distortion of the orientation main axis is reduced, and in order to improve the strength such as heat resistance, further in the film longitudinal direction (film running direction) or film width direction It is preferable to perform a relaxation treatment. The amount of relaxation in this case is preferably adjusted so that the heat shrinkage at 150 ° C. of the biaxially stretched polyethylene terephthalate film after the relaxation treatment is 1 to 10%, more preferably 2 to 5%. .

  In the present invention, a biaxially stretched polyethylene terephthalate film having a maximum value of the distortion of the orientation main axis (shift angle with respect to the stretching axis) of 30 degrees or less, more preferably 10 degrees or less, and further preferably 5 degrees or less is suitably used. When a polarizing plate using a biaxially stretched polyethylene terephthalate film having a maximum value of the distortion of the orientation main axis exceeding 30 degrees is bonded to a liquid crystal display screen of a liquid crystal display device, the coloring failure tends to increase. Further, the lower limit value of the maximum strain value of the orientation main axis of the biaxially stretched polyethylene terephthalate film is not particularly limited, but is preferably 0 degree or more. The maximum value of the orientation main axis strain of the biaxially stretched polyethylene terephthalate film described above is, for example, a retardation film inspection apparatus RETS system (manufactured by Otsuka Electronics Co., Ltd.), a microwave transmission type molecular orientation meter (MOA) (Oji Paper Co., Ltd.). It can measure by using (made by Co., Ltd.).

The thickness d _PET biaxially oriented polyethylene terephthalate film used in the present invention is preferably in the range of 20 to 60 [mu] m, and more preferably in a range of 30 to 50 [mu] m. When the thickness d _PET of the biaxially stretched polyethylene terephthalate film is less than 20 μm, it tends to be difficult to handle (inferior in handleability), and when the thickness d _PET exceeds 60 μm, the merit of thinning is reduced. There is a tendency.

In addition, the in-plane retardation value R _PET of the biaxially stretched polyethylene terephthalate film used in the present invention is preferably 1000 nm or more, and more preferably 3000 nm or more. When the in-plane retardation value R _{PET of the} biaxially stretched polyethylene terephthalate film is less than 1000 nm, coloring from the front tends to be conspicuous. The upper limit of the in-plane retardation value R _PET of the polyethylene terephthalate film used in the present invention is sufficient up to about 10,000 nm.

The in-plane retardation value R _PET of the biaxially stretched polyethylene terephthalate film is represented by the following formula (1).

_{R PET = (n a -n b} ) × d PET (1)
(In the above formula (1), n _a is the refractive index in the in-plane slow axis direction of the biaxially stretched polyethylene terephthalate film, and n _b is the in-plane fast axis direction (the direction orthogonal to the in-plane slow axis direction). (Refractive index, d _PET is the thickness of a biaxially stretched polyethylene terephthalate film.)
The biaxially stretched polyethylene terephthalate film used in the present invention preferably has a MOR (Maximum Oriented Ratio) value of 1.5 or more, more preferably 2.0 or more, and 2.2 or more. Is particularly preferred. This is because when a polarizing plate using a biaxially stretched polyethylene terephthalate film having an MOR value of less than 1.5 is applied to a liquid crystal display device, the oblique interference unevenness tends to increase. The upper limit of the MOR value of the biaxially stretched polyethylene terephthalate film is not particularly limited, but 7 or less is sufficient. Here, the MOR value is a ratio (maximum value / minimum value) between the maximum value and the minimum value of the transmission microwave intensity measured by a transmission type molecular orientation meter, and serves as an anisotropy index. The MOR value can be measured using a microwave transmission type molecular orientation meter (manufactured by Oji Scientific Instruments).

  A stretched polyethylene terephthalate film can be produced by forming the raw resin into a film and subjecting it to a stretching treatment. Stretching is uniaxial stretching in the MD direction (flow direction) or TD direction (direction perpendicular to the flow direction), biaxial stretching in both the MD direction and the TD direction, and stretching in a direction that is neither the MD direction nor the TD direction. Any method such as oblique stretching may be used. By performing such stretching operation, a polyethylene terephthalate resin film having high mechanical strength can be obtained. Among them, a uniaxially stretched film is preferable because interference unevenness tends not to be visible when the polarizing plate of the present invention is installed in a liquid crystal panel.

  The method for producing the uniaxially stretched polyethylene terephthalate film is arbitrary and is not particularly limited. However, the non-oriented film obtained by melting the raw material resin and extruding the sheet resin at a temperature equal to or higher than the glass transition temperature is used. A method of performing heat setting treatment after transverse stretching (stretching in the TD direction) with a tenter can be mentioned. The stretching temperature is preferably 80 to 130 ° C., more preferably 90 to 120 ° C., and the stretching ratio is preferably 2.5 to 6 times, more preferably 3 to 5.5 times. When the draw ratio is low, the polyethylene terephthalate resin film tends not to exhibit sufficient transparency. In the case of biaxial stretching, for example, a method of longitudinally stretching (stretching in the MD direction) a non-oriented film extruded into a sheet shape at a temperature equal to or higher than the glass transition temperature and then laterally stretching (stretching in the TD direction) And a method of stretching in the vertical and horizontal directions.

  Moreover, the anti-glare property (haze) may be provided to the biaxially stretched polyethylene terephthalate film used in the present invention. The method for imparting antiglare properties is not particularly limited. For example, the raw material resin is mixed with inorganic fine particles or organic fine particles to form a film, and the biaxially stretched polyethylene terephthalate film polarizing film is laminated on the side. And a method of forming an antiglare layer by coating the opposite surface with a coating solution obtained by mixing inorganic fine particles or organic fine particles with a resin binder. Among them, from the viewpoint of reducing color unevenness (interference unevenness) derived from a polyethylene terephthalate film, the structure further includes an antiglare layer laminated on the surface opposite to the side on which the polarizing film of the biaxially stretched polyethylene terephthalate film is laminated. It is preferable to realize the polarizing plate of the present invention.

  Typical inorganic fine particles for imparting antiglare properties include silica, colloidal silica, alumina, alumina sol, aluminosilicate, alumina-silica composite oxide, kaolin, talc, mica, calcium carbonate, calcium phosphate, and the like. be able to. 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.

  In addition, a cellulose-based resin film such as triacetyl cellulose (TAC), an olefin-based resin film on the surface opposite to the side on which the polarizing film of the biaxially stretched polyethylene terephthalate film is laminated via an adhesive layer or an adhesive layer The antiglare property may be imparted by a method of laminating an antiglare protective film comprising an acrylic resin film or a polyester resin film. The antiglare protective film is produced by a method of coating the surface of a base film with a coating solution, a method of forming a resin film by mixing organic fine particles or inorganic fine particles in a resin as a base material, and the like. Can be suitably used. In the case of using such an antiglare protective film, the thickness is preferably in the range of 5 to 120 μm, and more preferably in the range of 20 to 80 μm. Moreover, it is preferable that the haze value of such an anti-glare protective film is in the range of 2 to 45%. This is because the antiglare effect may be impaired when the haze value of the antiglare protective film is less than 2%, and when the haze value of the antiglare protective film is higher than 45%, the screen This is because there is a concern that the visibility may be reduced.

  Moreover, surface treatments, such as a glare-proof process, a hard-coat process, an antistatic process, may be given to the surface on the opposite side to the side which laminates | stacks the polarizing film of a biaxially stretched polyethylene terephthalate film. In addition, a coat layer made of a liquid crystalline compound or a high molecular weight compound thereof may be formed. Note that substantially the same effect can be obtained by using a biaxially stretched polyethylene naphthalate film instead of the biaxially stretched polyethylene terephthalate film.

  In the polarizing plate of the present invention, a protective film or an optical compensation film may be laminated on the side of the polarizing film opposite to the side on which the biaxially stretched polyethylene terephthalate film is laminated. Examples of the protective film or the optical compensation film include transparent films such as a cellulose resin film such as a triacetyl cellulose film (TAC film), an olefin resin film, an acrylic resin film, and a polyester resin film. Moreover, you may make it laminate | stack the optical functional film mentioned later on such a transparent film.

  The cellulose-based resin film is a film of a cellulose part or a completely esterified product, and examples thereof include a film made of cellulose acetate ester, propionate ester, butyrate ester, mixed ester thereof and the like. 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), KC8UY (manufactured by Konica Minolta Opto), and the like.

  Moreover, as an optical compensation film comprising a cellulose resin film, 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 the cellulose film, a cellulose film Examples thereof include a film obtained by uniaxially stretching or biaxially stretching a film. Moreover, in the polarizing plate of this invention, the cellulose acetate type-resin film provided with the phase difference characteristic is also used suitably, As a commercial item of the cellulose acetate type-resin film provided with this phase difference characteristic, WV BZ 438 ( Fuji Film Co., Ltd.), WV EA (Fuji Film Co., Ltd.), KC4FR-1 (Konica Minolta Opto Co., Ltd.), KC4HR-1 (Konica Minolta Opto Co., Ltd.) and the like.

  Alternatively, the cycloolefin resin film may be uniaxially stretched or biaxially stretched to form an optical compensation film. The cycloolefin resin film is a film made of a thermoplastic resin having a monomer unit made of a cyclic olefin (cycloolefin) such as norbornene or a polycyclic norbornene monomer. The cycloolefin-based 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. It may also be 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.

  When 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 and propylene. As the aromatic compound having a vinyl group, Examples include styrene, α-methylstyrene, and nuclear alkyl-substituted styrene. In such a copolymer, the monomer unit composed of cycloolefin may be 50 mol% or less (preferably 15 to 50 mol%). In particular, when a terpolymer of a cycloolefin, a chain olefin, and an aromatic compound having a vinyl group is used, the amount of the monomer unit composed of the cycloolefin can be made relatively small as described above. In such a terpolymer, the monomer unit composed of a chain olefin is usually 5 to 80 mol%, and the monomer unit composed of an aromatic compound having a vinyl group is usually 5 to 80 mol%.

  Cycloolefin-based resins may be commercial products such as Topas (manufactured by Ticona), Arton (manufactured by JSR Corporation), ZEONOR (manufactured by Nippon Zeon Co., Ltd.), ZEONEX (manufactured by Nippon Zeon Corporation). ) And Apel (Mitsui Chemicals) can be preferably used. When such a cycloolefin-based resin is formed into a film, a known method such as a solvent casting method or a melt extrusion method is appropriately used. In addition, for example, Essina (manufactured by Sekisui Chemical Co., Ltd.), SCA40 (manufactured by Sekisui Chemical Co., Ltd.), Zeonoa Film (manufactured by Optes Co., Ltd.), Arton Film (manufactured by JSR Co., Ltd.), etc. A commercially available cycloolefin resin film may be used as the transparent protective film.

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 to 100 nm, and more preferably 40 to 80 nm. 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. The thickness direction retardation R _th for the stretched cycloolefin resin film is preferably 80 to 300 nm, more preferably 100 to 250 nm. When the thickness direction retardation value _Rth is less than 80 nm or exceeds 300 nm, the viewing angle compensation ability for the 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 (2) and (3), respectively, for example, KOBRA 21ADH (Oji Scientific Instruments ( It is possible to measure using

_{R 0 = (n x -n y} ) × d (2)
R _th = [( _nx + _ny ) / 2- _nz ] × d (3)
(The above formula (2), (in 3), n _x is stretched in-plane slow axis direction of the refractive index of the cycloolefin resin film, n _y in-plane fast axis direction (in-plane slow axis direction refractive index in the orthogonal direction to) a, the n _z refractive index in the thickness direction of the cycloolefin-based resin film stretched, d is the thickness of the cycloolefin resin film stretched.)
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). By performing stretching under relatively loose conditions, the above preferable refractive index characteristics can be obtained. For example, the stretching ratio is preferably 1.05 to 1.6, and more preferably 1.1 to More preferably, it is 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 stretched cycloolefin-based resin film is too thick, the processability becomes 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 of the stretched cycloolefin-based resin film is preferably in the range of 40 to 80 μm.

  In the polarizing plate of the present invention, as described above, a biaxially stretched polyethylene terephthalate film is laminated on one side of the polarizing film via an adhesive layer, and if necessary, a biaxially stretched polyethylene terephthalate film of the polarizing film is laminated. A protective film or an optical compensation film is laminated on the surface opposite to the formed side. From the viewpoint of thinning the adhesive layer, the adhesive used for laminating these films includes an aqueous one, that is, an adhesive component dissolved in water or dispersed in water. . For example, a composition using a polyvinyl alcohol resin or a urethane resin as a main component can be mentioned as a preferred adhesive. In addition, when bonding a film on both surfaces of a polarizing film, the same kind of adhesive agent may be used and a different kind of adhesive agent may be used, respectively.

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

  It is preferable to add a curable component such as glyoxal or a water-soluble epoxy resin and a crosslinking agent to the adhesive composed of an aqueous solution of a polyvinyl alcohol resin in order to increase the adhesiveness. As the water-soluble epoxy resin, for example, a polyamide polyamine epoxy resin obtained by reacting a polyalkylene polyamine such as diethylenetriamine or triethylenetetramine with a polycarboxylic acid such as adipic acid and epichlorohydrin. Can be suitably used. Commercially available products of such polyamide polyamine epoxy resins include Sumire's Resin 650 (manufactured by Sumika Chemtex Co., Ltd.), Sumire's Resin 675 (manufactured by Sumika Chemtex Co., Ltd.), WS-525 (manufactured by Nippon PMC Corporation). Etc. The addition amount of these curable component and crosslinking agent (when added together, the total amount) 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. . When the addition amount of the curable component and the crosslinking agent is less than 1 part by weight with respect to 100 parts by weight of the polyvinyl alcohol-based resin, the effect of improving adhesiveness tends to be reduced, and the curable component, This is because the adhesive layer tends to be brittle when the addition amount of the crosslinking agent exceeds 100 parts by weight with respect to 100 parts by weight of the polyvinyl alcohol resin.

  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 type urethane resins are known per se. For example, JP-A-7-97504 describes an example of a polymer dispersant for dispersing a phenolic resin in an aqueous medium. In JP-A-2005-70140 (Patent Document 2) and JP-A-2005-208456 (Patent Document 4), a mixture of a polyester ionomer type urethane resin and a compound having a glycidyloxy group is used as an adhesive. A form in which a cycloolefin resin film is bonded to a polarizing film made of a polyvinyl alcohol resin is shown.

  As a method of laminating the above-mentioned biaxially stretched polyethylene terephthalate film (and a protective film or an optical compensation film, if necessary) to the polarizing film, generally known methods may be used, for example, casting method, Meyer Apply an adhesive to the adhesive surface of the polarizing film and / or the film to be bonded to it by the bar coating method, gravure coating method, comma coater method, doctor blade method, die coating method, dip coating method, spraying method, etc. The method of superimposing can be 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 method mentioned above, a polarizing film and the film bonded by it are pinched | interposed by a nip roll etc., and are bonded together. Moreover, after dripping an adhesive agent between a 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, it is possible to use metal or rubber as the material of the roll. Furthermore, after dropping an adhesive agent between a polarizing film and the film bonded to it, the method of passing this laminated body between rolls and pressurizing and spreading is also preferably employed. In this case, these rolls may be made of the same material or different materials. The thickness of the adhesive layer after being bonded using the nip roll or the like before drying or curing is preferably 5 μm or less, and more preferably 0.01 μm or more.

  Further, the surface of the adhesive layer may be appropriately subjected to surface treatment such as plasma treatment, corona treatment, ultraviolet irradiation treatment, flame (flame) treatment, saponification treatment, etc., in order to improve adhesion. 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 1200 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 several days or longer. Such curing is typically performed in a state of being wound into 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.

  Moreover, a photocurable adhesive agent can also be used for the adhesive agent in the polarizing plate of this invention. As a photocurable adhesive agent, mixtures, such as a photocurable epoxy resin and a photocationic polymerization initiator, are mentioned, for example. In this case, the photocurable adhesive is cured by irradiating with active energy rays. 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. Specifically, the low-pressure mercury lamp, the medium-pressure mercury lamp, the high-pressure mercury lamp, the ultrahigh-pressure mercury lamp, the chemical lamp, and the black light lamp A microwave excitation mercury lamp, a metal halide lamp and the like are preferable.

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 the irradiation intensity is 6000 mW / cm ² or less, the heat radiated from the light source and the curing time of the photo-curable adhesive are reduced. There is little risk of yellowing of the epoxy resin or deterioration of the polarizing film due to heat generation. The light irradiation time to the photocurable adhesive is controlled for each photocurable adhesive when 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 / m ² . When the integrated light quantity to the photocurable adhesive is 10 mJ / m 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 10000 mJ / m. ^{By being 2} or less, irradiation time does not become too long, and favorable 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 curing a photocurable adhesive by irradiation of active energy rays, the polarization degree, transmittance and hue of the polarizing film, and the polarizing film such as biaxially stretched polyethylene terephthalate film, protective film and transparency of the optical compensation film, etc. It is preferable to perform the curing under conditions that do not reduce the various functions.

  The polarizing plate of the present invention has an outer surface opposite to the side on which the biaxially stretched polyethylene terephthalate film is laminated (if the protective film or optical compensation film is laminated, the protective film or optical compensation film). It is preferable that a pressure-sensitive adhesive layer for bonding the polarizing plate to the liquid crystal cell is formed on the side opposite to the side laminated on the polarizing film. As the pressure-sensitive adhesive used for such a pressure-sensitive adhesive layer, a conventionally known appropriate pressure-sensitive adhesive can be used without particular limitation, and examples thereof include an acrylic pressure-sensitive adhesive, a urethane pressure-sensitive adhesive, and a silicone pressure-sensitive adhesive. Among these, an acrylic pressure-sensitive adhesive is preferably used from the viewpoints of transparency, adhesive strength, reliability, reworkability, and the like. The pressure-sensitive adhesive layer can be provided by a method in which such a pressure-sensitive adhesive is used, for example, in the form of an organic solvent solution, which is applied to a base film with a die coater or a gravure coater, and dried. Can be provided also by a method of transferring a sheet-like pressure-sensitive adhesive formed on a plastic film (referred to as a separate film) to the base film. Although there is no restriction | limiting in particular also about the thickness of an adhesive layer, Generally it is preferable to exist in the range of 2-40 micrometers.

  An optical functional film may be attached to the outer surface of the polarizing plate via the pressure-sensitive adhesive layer. Examples of the optical functional film include, in addition to the above-described optical compensation film based on the cellulose-based film or the cycloolefin-based film, an optical compensation film in which a liquid crystal compound is applied to the substrate surface and oriented, A reflective polarizing film that transmits certain types of polarized light and reflects polarized light that exhibits the opposite properties, a retardation film made of polycarbonate resin, a film with an antiglare function that has an uneven surface, and a surface antireflection 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. Commercially available products corresponding to an optical compensation film coated with a liquid crystal compound on the substrate surface and oriented are WV film (Fuji Film Co., Ltd.), NH film (Shin Nippon Oil Co., Ltd.), NR Examples include films (manufactured by Nippon Oil Corporation). For example, DBEF (manufactured by 3M, available from Sumitomo 3M Co., Ltd. in Japan) is a commercially available product that corresponds to a reflective polarizing film that transmits certain types of polarized light and reflects polarized light that exhibits the opposite properties. Etc. Moreover, as a commercial item corresponding to the retardation film which consists of cyclic polyolefin resin, for example, Arton Film (made by JSR Corporation), Essina (made by Sekisui Chemical Co., Ltd.), Zeonoor Film (made by Optes Co., Ltd.) Etc.

  The present invention also provides a liquid crystal display device including a liquid crystal panel in which the above-described polarizing plate of the present invention is bonded to a liquid crystal cell via an adhesive layer. In this case, the polarizing plate of the present invention is bonded to the back side or the front side of the liquid crystal cell, or to the back side and the front side. Such a liquid crystal display device of the present invention includes a liquid crystal panel in which the polarizing plate of the present invention is bonded to the back surface of the liquid crystal cell, and thus has sufficient mechanical strength while supporting thinning. By disposing the biaxially stretched polyethylene terephthalate film side of the polarizing plate of the present invention on the back side of the liquid crystal panel, a liquid crystal display device capable of preventing contact between the liquid crystal panel and the backlight system is provided. In the liquid crystal display device of the present invention, for the portions other than the above-described features, an appropriate configuration of a conventionally known liquid crystal display device can be adopted, and the configuration requirements (light diffusing plate) that the liquid crystal display device normally includes other than the liquid crystal panel The backlight is not particularly limited.

  The light diffusing plate is an optical member having a function of diffusing light from a backlight. For example, a light diffusing agent is provided by dispersing particles as a light diffusing agent in a thermoplastic resin, Used are those in which irregularities are formed on the surface of a plastic resin plate to impart light diffusibility, and a coating layer of a resin composition in which particles are dispersed is provided on the surface of a thermoplastic resin plate to impart light diffusibility. It is done. The thickness of the light diffusion plate is not particularly limited, but is preferably in the range of 0.1 to 5 mm. Further, between the light diffusion plate and the liquid crystal panel, a prism sheet (also called a condensing sheet, such as BEF (manufactured by 3M), etc.), a brightness enhancement sheet (same as the above-described reflective polarizing film). It is also possible to dispose a sheet exhibiting other optical functionality, such as a light diffusion sheet (such as DBEF described above). A plurality of types of sheets exhibiting other optical functionalities can be arranged as necessary. Further, as the light diffusing plate, for example, a light diffusing function such as a laminated integrated product of a prism sheet having a cylindrical shape on the surface and a light diffusing plate (for example, those described in JP-A-2006-284497) It is also possible to use an optical sheet in which other functions are combined.

  The polarizing plate of the present invention is suitably used in the configuration of backlight / light diffusion plate / light diffusion sheet / brightness enhancement sheet / liquid crystal cell. The “rear side” of the liquid crystal cell and liquid crystal panel described above means the backlight side when the liquid crystal panel is mounted on the liquid crystal display device, and the “front side” of the liquid crystal cell and liquid crystal panel means the liquid crystal panel. Means the viewing side when mounted on a liquid crystal display device.

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to examples. However, the present invention is not limited to these examples. In the examples, “%” and “part” representing the content or amount used are based on weight unless otherwise specified. In the following example, the in-plane retardation value R _{PET of} the biaxially stretched polyethylene terephthalate film, the in-plane retardation value R ₀ and the thickness direction retardation value R _th of the optical compensation film made of stretched norbornene resin are KOBRA 21ADH ( The value measured using Oji Scientific Instruments). Moreover, the maximum value of the distortion of the orientation main axis of the biaxially stretched polyethylene terephthalate film and the MOR indicate values measured using a microwave transmission type molecular orientation meter (manufactured by Oji Scientific Instruments).

<Example 1>
A polyvinyl alcohol film having an average polymerization degree of about 2400 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 the weight ratio of iodine / potassium iodide / water was 0.02 / 2. / 100 aqueous solution at 30 ° C. 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, the film was washed with pure water at 8 ° C. and then 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.

On one side of the polarizing film obtained as described above, a biaxially stretched polyethylene terephthalate film having a thickness of d _{PET of} 37 μm (in-plane retardation value R _PET : 1900 nm, maximum value of strain of orientation main axis: 4 degrees, MOR: 2.0) was subjected to corona treatment on the bonding surface, and then bonded and bonded via a photocurable adhesive.

Next, on the opposite side of the polarizing film on which the biaxially stretched polyethylene terephthalate film was laminated, an optical compensation film (in-plane retardation value R ₀ : 63 nm, thickness direction retardation value) made of a stretched norbornene resin having a thickness of 73 μm. R _th : 225 nm) was subjected to a corona treatment on the bonding surface, and then adhered through a photocurable adhesive to obtain a polarizing plate.

  The obtained polarizing plate was difficult to tear and was also lighter than a normal polarizing plate. An acrylic adhesive layer having a thickness of 25 μm is provided on the outer surface of the optical compensation film of the polarizing plate, and the outer surface side of the optical compensation film on which the adhesive layer is formed is disposed on the back surface of the liquid crystal cell. Assembles a liquid crystal panel by placing a commercially available polarizing plate (Sumikaran SRW842E-GL5, manufactured by Sumitomo Chemical Co., Ltd.), and using this, a commercially available backlight / light diffusion plate / light diffusion sheet / light diffusion sheet / liquid crystal panel A liquid crystal display device constructed in this order was fabricated. About the obtained liquid crystal display device, when the display was observed visually, the nonuniformity by contact with a backlight was not seen. Moreover, the interference nonuniformity originating in the polyethylene terephthalate film when it sees from the diagonal direction was not seen, and visibility was favorable.

  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 of the claims.

Claims (5)

  A polarizing plate comprising a polarizing film made of a polyvinyl alcohol-based resin and a biaxially stretched polyethylene terephthalate film laminated on one side of the polarizing film via an adhesive layer.   The polarizing plate according to claim 1, further comprising an antiglare layer laminated on a surface opposite to the side on which the polarizing film of the biaxially stretched polyethylene terephthalate film is laminated.   The polarizing plate according to claim 1, further comprising a protective film or an optical compensation film laminated on the side opposite to the side on which the biaxially stretched polyethylene terephthalate film is laminated.   The polarizing plate according to claim 1, further comprising a pressure-sensitive adhesive layer on the outer surface opposite to the side on which the biaxially stretched polyethylene terephthalate film of the polarizing film is laminated.   A liquid crystal display device provided with the liquid crystal panel by which the polarizing plate of Claim 4 is bonded by the liquid crystal cell through the adhesive layer.