JP2005114995A - Polarizing plate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a highly durable polarizing plate that has no light leak in a heat test, no fading in a humidity test, and no cracks after an endurance test. <P>SOLUTION: The polarizing plate is used by being stuck to a liquid crystal cell and constituted by laminating a polarizer protective film on both sides of a polarizer. The polarizing plate is characterized in that the polarizer protective film on the opposite side from the liquid crystal cell is a film having a parallel beam transmissivity of ≥85%, a water vapor permeability of 20-200 g/m<SP>2</SP>/day, a tension fracture strength of ≥55 MPa, and a tension fracture ductility of ≥10%, and that the polarizer protective film on the liquid crystal cell side is a film having a parallel beam transmissivity of ≥85%, a water vapor permeability of 20-200 g/m<SP>2</SP>/day, and a photoelastic coefficient of ≤1.0×10<SP>-11</SP>Pa<SP>-1</SP>. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a polarizing plate used for a liquid crystal display (hereinafter abbreviated as “LCD”), and more particularly to a polarizing plate excellent in durability.

  In recent years, LCDs have been used in mobile phones and personal digital assistants, so that optical films for LCDs are further required to be thin and highly durable. However, there is a contradiction between thinness and high durability, and it has become difficult for conventional materials to satisfy both at the same time. Conventionally, a triacetyl cellulose film (hereinafter abbreviated as “TAC”) is used as a polarizer protective film laminated on both sides to protect the polarizer. However, if the TAC is made into a thin film, there is a problem in durability. There is a case. This is because moisture permeates into the polarizing plate because TAC has high moisture permeability, and as a result, the polarizer is faded. Further, as another problem related to the durability of a polarizing plate using TAC as a polarizer protective film, when a heat resistance test is performed, there is a problem that light leaks in a frame shape around the polarizing plate. This is a problem that occurs because the photoelastic coefficient of TAC is large. To solve these problems, Patent Document 1 proposes a polarizing plate using a norbornene-based resin as a protective film.

  However, when the present inventor conducted a durability test of a polarizing plate using a norbornene-based resin as a polarizer protective film, the inventor found a problem that a crack occurs in the protective film on the side opposite to the liquid crystal cell after the durability test. It has been known that an injection molded product made of a cyclic olefin resin containing a norbornene resin and having a large residual stress generates cracks (Patent Document 2), but the film having a low residual stress used for a polarizer protective film cracks. Was not known to occur.

  When this is used as a polarizing plate and subjected to an endurance test, since the contraction stress accompanying the contraction of the polarizer due to a decrease in the amount of moisture in the polarizer is applied to the polarizer protective film, the polarizer is protected before being attached to the polarizer. Even if the residual stress of the film is low, it is considered that cracks have occurred after the bonding durability test. In order to solve these problems, a method using a resin other than norbornene resin can be considered. For example, in the example of Patent Document 3, it is proposed to use a polycarbonate resin on both sides, but when a resin film having a high photoelastic coefficient such as polycarbonate is used on the liquid crystal cell side of the polarizing plate, as described above. A frame-shaped light leak occurs in the heat test. On the other hand, although the invention using TAC for the protective film on the opposite side of the liquid crystal cell has been proposed (Patent Document 4), as described above, the problem that the polarizer fades in the moisture resistance test cannot be solved.

JP-A-6-511117 Japanese Patent Laid-Open No. 11-178690 JP 2002-90546 A JP 2002-221619 A

  The problem to be solved by the present invention is to provide a polarizing plate having high durability without light leakage in a heat resistance test, fading in a moisture resistance test and occurrence of cracks after the durability test, which could not be solved by the prior art. It is.

The polarizing plate which concerns on 1st invention is a polarizing plate which a polarizer protective film is laminated | stacked on both sides of a polarizer used by bonding to a liquid crystal cell, Comprising: The polarizer protective film on the opposite side to a liquid crystal cell Is a film having a parallel light transmittance of 85% or more, a moisture permeability of 20 to 200 g / m ² / day, a tensile breaking strength of 55 MPa or more, and a tensile breaking elongation of 10% or more, and the polarizer protective film on the liquid crystal cell side is parallel. It is a polarizing plate characterized by being a film having a light transmittance of 85% or more, a moisture permeability of 20 to 200 g / m ² / day, and a photoelastic coefficient of 1.0 × 10 ⁻¹¹ Pa ⁻¹ or less.

  The polarizing plate according to the second invention is the polarizing plate according to the first invention, wherein the polarizer protective film opposite to the liquid crystal cell is a polycarbonate resin, a polysulfone resin, a polyethersulfone resin, or a polyester resin. The polarizing plate is a film made of a resin.

  The polarizing plate according to the third invention is the polarizing plate according to the first invention or the polarizing plate according to the second invention, wherein the polarizer protective film on the liquid crystal cell side is a norbornene resin, an olefin-maleimide resin, or The polarizing plate is a film made of a polyvinyl acetal resin.

Hereinafter, the present invention will be described in detail.
The polarizing plate in this invention means what laminated | stacked the polarizer protective film on both surfaces of the polarizer.
The polarizer in the present invention refers to a film or sheet made of polyvinyl alcohol (hereinafter abbreviated as “PVA”) having the function of a polarizer. For example, after adsorbing iodine to a PVA film, it is uniaxial in a boric acid bath. After a dichroic direct dye is diffused and adsorbed on a stretched PVA / iodine polarizer and PVA film, iodine is adsorbed on the uniaxially stretched PVA / dye polarizer and PVA film and stretched to form a polyene structure. PVA / polyene polarizing film may be used.

  The polarizer protective film in the present invention is required to have a transparency of 85% or more in terms of parallel light transmittance regardless of whether it is laminated on the liquid crystal cell side or the opposite side of the liquid crystal cell, and preferably 90%. % Or more. If it is less than 85%, the luminance is insufficient when mounted on an LCD, which is not preferable.

  As for the glass transition temperature (Tg) of resin used for the polarizer protective film in this invention, 100 degreeC or more is preferable, More preferably, it is 110 degreeC or more, More preferably, it is 120 degreeC or more. This is because if Tg is low, thermal deformation may occur in the drying process during the production of the polarizing plate.

  The polarizing plate in the present invention is used by being attached to a liquid crystal cell via an adhesive or a pressure-sensitive adhesive. A liquid crystal cell is usually formed by filling a liquid crystal in a gap between two transparent plates such as a glass plate on which a transparent electrode is formed. In the liquid crystal cell to which the polarizing plate is bonded, the opposite side of the liquid crystal cell / viscous (contact) adhesive / liquid crystal cell side polarizer protective film / viscous (contact) adhesive / polarizer / viscous (contact) adhesive / liquid crystal cell The polarizer protective films are laminated in this order.

The moisture permeability of the resin film used for the polarizer protective film on the side opposite to the liquid crystal cell in the present invention is 20 to 200 g / m ² / day regardless of its thickness. If it is less than 20 g / m ² / day, the moisture content in the polarizer is high because the moisture in the polarizer and the adhesive is not sufficiently evaporated through the protective film in the drying process of the adhesive, and as a result, the adhesive strength is high. It is difficult to obtain, and the polarizing performance and durability of the obtained polarizing plate deteriorate, which is not preferable. On the other hand, if it exceeds 200 g / m ² / day, the moisture resistance of the obtained polarizing plate deteriorates, which is not preferable. The thickness of the resin film is 10 to 200 μm, preferably 20 to 100 μm, and more preferably 30 to 80 μm.

  Further, the tensile breaking strength of this film needs to be 55 MPa or more, and more preferably 60 MPa or more. If it is less than 55 MPa, when the heat resistance test of the obtained polarizing plate is carried out, if it is left at room temperature after completion of the heat resistance test, cracks occur on the opposite side of the liquid crystal cell, which is not preferable.

  Furthermore, the tensile breaking elongation of this film needs to be 10% or more. If it is less than 10%, it is not preferred that the obtained polarizing plate be subjected to a heat resistance test, because if it is left at room temperature after the heat resistance test, cracks occur on the opposite side of the liquid crystal cell.

  The resin used in such a film is not particularly limited as long as the parallel light transmittance, moisture permeability, breaking strength, and breaking elongation satisfy the above requirements, but polycarbonate resin, polyester resin, polysulfone resin, acrylic resin , Polyether ketone resins, polyether sulfone resins, polyarylate resins, polyolefin resins, polyphenylene sulfide resins, polyimide resins, polyamideimide resins, and the like.

  Of these, polycarbonate resins, polysulfone resins, polyether sulfone resins, and polyester resins are particularly preferable. These have high transparency to ensure the brightness of the LCD, and since they have appropriate moisture permeability, it is easy to achieve both fading suppression in the moisture resistance test and drying of the wet laminate during the production of the polarizing plate, as well as tensile breaking strength and tensile strength. This is because crack elongation does not occur even when left at room temperature after the end of the heat resistance test because the elongation at break is high.

  The resin film used for the protective film on the side opposite to the liquid crystal cell in the present invention can be used regardless of whether or not it is stretched, and the stretching may be uniaxial or biaxial. The stretching at this time can be appropriately adjusted in terms of the transparency and mechanical strength of the film.

Next, as a resin film used for the protective film on the liquid crystal cell side in the present invention, the photoelastic coefficient needs to be 1.0 × 10 ⁻¹¹ Pa ⁻¹ or less. When the photoelastic coefficient exceeds 1.0 × 10 ⁻¹¹ Pa ⁻¹ , a frame-shaped light leakage occurs around the polarizing plate when the obtained polarizing plate is subjected to a heat resistance test.

The resin used for such a film is not particularly limited as long as the parallel light transmittance, moisture permeability, and photoelastic coefficient satisfy the above requirements, but as such a resin, a norbornene resin, an olefin-maleimide resin, A polyvinyl acetal resin is preferred. This is because the transparency of the LCD is high and the brightness of the LCD can be secured, and the photoelastic coefficient is low, so that no frame-like light leakage occurs even if a heat resistance test is performed. Further, it is preferable to have an appropriate moisture permeability of ^{20 to} 200 g / m ² / day because it is possible to achieve both fading suppression in the moisture resistance test and drying of the wet laminate during the production of the polarizing plate.

  As the resin film used for the protective film on the liquid crystal cell side in the present invention, a resin film in which birefringence is suppressed as much as possible is usually used, but it may have a retardation compensation function. As the phase difference compensation function, the film may be uniaxially or biaxially stretched or coated with a liquid crystal polymer. Moreover, thickness is 10-200 micrometers, Preferably it is 20-100 micrometers, More preferably, it is 30-80 micrometers.

  Although the manufacturing method of the resin film in this invention is not specifically limited, Well-known methods, such as a solution cast method and a melt extrusion method, can be used.

  The norbornene resin is preferably a thermoplastic saturated norbornene resin. For example, a resin obtained by hydrogenating a ring-opening (co) polymer of a norbornene monomer, a resin obtained by addition polymerization of a norbornene monomer, a norbornene monomer and ethylene, Examples thereof include resins obtained by addition copolymerization with an olefin monomer such as α-olefin. These resins are also commercially available as described below.

  The norbornene-based monomer used in the present invention is not particularly limited as long as it has a norbornene ring, but since a molded product excellent in heat resistance, low linear expansion coefficient, etc. is obtained, a tricyclic or higher polycyclic norbornene is obtained. It is preferable to use a system monomer.

  Specific examples of the norbornene-based monomer include bicyclics such as norbornene and norbornadiene; tricyclics such as dicyclopentadiene and dihydroxypentadiene; tetracyclics such as tetracyclododecene; pentacyclics such as cyclopentadiene trimer. A heptacycle such as tetracyclopentadiene; an alkyl such as methyl, ethyl, propyl, butyl, an alkenyl such as vinyl, an alkylidene such as ethylidene, an aryl such as phenyl, tolyl, and naphthyl; and an ester thereof Group other than carbon and hydrogen, such as group, ether group, cyano group, halogen atom, alkoxycarbonyl group, pyridyl group, hydroxyl group, carboxylic acid group, amino group, hydroxyl group-free, silyl group, epoxy group, acrylic group, methacryl group Examples thereof include substituted groups having a so-called polar group. Among these, an ester group and a hydroxyl group-free are preferable. These monomers are used alone or in combination of two or more. Tricyclic, tetracyclic, and pentacyclic monomers are preferred because they are easily available, have excellent reactivity, and have excellent heat resistance of the resulting resin molded product.

  There are commercially available norbornene resins such as ZEONOR # 1600R, ZEONOR # 1420R, ZEONEX # 490K manufactured by Nippon Zeon, and ARTON G manufactured by JSR. Examples of the olefin-maleimide resin include TI-160α manufactured by Tosoh Corporation. Furthermore, the polyvinyl acetal resin is obtained by acetalization reaction of polyvinyl alcohol and aldehyde, and from the viewpoint of optics, heat resistance, physical properties, etc. Etc. are prepared and prepared for the purpose.

  In order to bond a polarizer protective film and a polarizer, since the bonding equipment currently used for the existing polarizing plate production line can be used as it is, the method by wet lamination is preferable. Wet lamination is a method in which substrates are attached to each other before the adhesive is dried, and then the solvent is evaporated through the substrate. Usually the solvent is aqueous. Specific examples include polyvinyl alcohol (PVA) adhesives, acrylic adhesives, polyurethane adhesives, and the like. The adhesive layer may be formed by a conventionally known method, such as a coating method or a dropping method. The bonding surface of the polarizer protective film with the polarizer may be subjected to a hydrophilic treatment such as a corona discharge treatment, an ultraviolet irradiation treatment, or a primer coating.

  The polarizing plate according to the present invention has high durability with no light leakage in the heat resistance test, fading in the moisture resistance test, and no occurrence of cracks after the durability test.

More details are as follows.
Since the polarizing plate according to the present invention has high transparency, high luminance can be obtained when mounted on an LCD. Since the tensile strength at break and tensile elongation at break are large, the obtained polarizing plate does not crack even when the durability test is performed. This is thought to be due to the fact that the tensile break strength of the protective film is large and can withstand breakage against the shrinkage stress of the PVA polarizer generated in the heat resistance test. If the tensile elongation at break of the film is large, the PVA polarizer shrinks. This is considered to be because it can be deformed accordingly and the shrinkage stress can be relaxed. Furthermore, since the water vapor transmission rate of the film is 20 to 200 g / m ² / day, a polarizing plate can be manufactured using a conventional bonding process, and even when wet laminating of an aqueous adhesive is performed, water content is moderate. It can evaporate and exhibits sufficient adhesive strength and durability. And even if a moisture resistance test is performed, the fading of the polarizer is suppressed. This is presumably because hydrolysis of the polarizer is suppressed because the moisture permeability of the protective film is low and the amount of water in contact with the PVA polarizer is reduced. In addition, since the photoelastic coefficient of the protective film on the liquid crystal cell side is 1.0 × 10 ⁻¹¹ Pa ⁻¹ or less, even if the contraction stress of the polarizer generated in the heat resistance test acts on the protective film, it is birefringent. Occurrence is suppressed, and frame-like light leakage as seen in conventional polarizing plates is not observed.

  Hereinafter, the present invention will be described in more detail by giving specific examples of the present invention. The present invention is not limited to the following examples.

(Production of polarizer)
An unstretched PVA film having a saponification degree of 99 mol% and a thickness of 75 μm was washed with water at room temperature, and then stretched 5 times in the longitudinal direction. The film was immersed in an aqueous solution consisting of 0.5 wt% iodine and 5 wt% potassium iodide while adsorbing the tension state of the film to adsorb the dichroic dye. Further, a crosslinking treatment was performed for 5 minutes with an aqueous solution of 10 wt% boric acid and 10 wt% potassium iodide at 50 ° C. to obtain a polarizer. This was dried at 70 ° C. for 5 minutes to adjust the water content to 8 wt%.

(Resin film # 1)
The adhesive surface of the polycarbonate film (thickness 75 μm) (trade name: Pure Ace, manufactured by Teijin Ltd.) with the polarizer was corona-treated. When the contact angle was measured using distilled water, it was 45 °.

(Resin film # 2)
The adhesive surface of the biaxially stretched PET film (thickness 50 μm) (trade name: Teijin Tetron Film O-50, manufactured by Teijin DuPont Films) with the polarizer was corona-treated. When the contact angle was measured using distilled water, it was 48 °.

(Resin film # 3)
A norbornene-based resin (trade name: ARTON G, manufactured by JSR Corporation) was melt-extruded into a film using a single screw extruder equipped with a T die. A resin film having a resin temperature of 290 ° C., a T die temperature of 285 ° C., a take-up roll temperature of 140 ° C., a roll speed of 20 m / min and a width of 450 mm and a length of 100 m was obtained. The thickness of the obtained film was 40 μm. The adhesion surface of the film with the polarizer was corona treated and the contact angle measured with distilled water was 44 °. The physical properties of the film are shown in Table 1.

(Resin film # 4)
An olefin-maleimide resin (trade name: TI-160α, manufactured by Tosoh Corporation) was melt-extruded into a film by using a single screw extruder equipped with a T die. A resin film having a resin temperature of 290 ° C., a T die temperature of 285 ° C., a take-up roll temperature of 140 ° C., a roll speed of 20 m / min and a width of 450 mm and a length of 100 m was obtained. The thickness of the obtained film was 40 μm. The adhesion surface of the film with the polarizer was corona treated and the contact angle measured with distilled water was 46 °. The physical properties of the film are shown in Table 1.

(Resin film # 5)
TAC film was used (Fuji Photo Film Co., Ltd., trade name: Fujitack, thickness 40 μm)

(Measurement and evaluation methods for various film properties)
(1) Measurement of film moisture permeability It was performed according to JIS-Z-0208.
(2) Measurement of photoelastic coefficient The film was cut into a width of 10 mm and a length of 150 mm, the phase difference at the center in the width direction was measured while applying a tensile load in the long side direction, and the photoelastic coefficient was calculated from the slope of the approximate straight line. Asked.
Load measurement: Force gauge DPS-5 (manufactured by IMADA)
Load level: 0, 0.5, 1.0, 1.5 kg (corresponding to about 0, 4.9, 9.8, 14.7 N, respectively)
Measurement of phase difference: RETS-2000 manufactured by Otsuka Electronics Co., Ltd., measurement wavelength 550 nm
(3) Measurement of tensile breaking strength and tensile breaking elongation It carried out according to JIS K7127.
The film used for the tensile test had a width of 20 mm, a total length of 200 mm, a test piece type 2, an initial distance between chucks of 150 mm, and a tensile speed of 20 mm / min.
(4) Measurement of parallel light transmittance The sample piece was a 50 mm square film measured with a haze meter.

(Production of acrylic adhesive)
A pressure-sensitive adhesive for bonding the glass plate and the polarizing plate was prepared as follows. On the PET film surface having a thickness of 38 μm which has been subjected to release treatment, an acrylic pressure-sensitive adhesive (trade name SK Dyne 905 manufactured by Soken Chemical Co., Ltd.), an isocyanate cross-linking agent (trade name L-45 manufactured by Soken Chemical Co., Ltd.) and an epoxy cross-linking agent (Soken Chemical Co., Ltd., trade name E-125B), aluminum chelate crosslinking agent (trade name M-12AT, manufactured by Soken Chemical Co., Ltd.), silicone additive (trade name SE-50, manufactured by Soken Chemical Co., Ltd.), and solid content with toluene The solution diluted to 13 wt% was coated so that the thickness after drying was 25 μm. After drying this with hot air at 60 ° C. × 2 minutes, 80 ° C. × 2 minutes, 90 ° C. × 2 minutes, and laminating a PET film that had been subjected to a release treatment with a light peeling thickness of 25 μm on the exposed adhesive surface, It was stored and cured in an environment of 40 ° C.

(Preparation of polarizing plate)
A polarizing plate was prepared by combining the polarizer and the resin films # 1 to 5 and bonded to a glass plate using the acrylic pressure-sensitive adhesive to prepare a durability evaluation test piece. At this time, the surface of the polarizing plate on which the acrylic pressure-sensitive adhesive was laminated was subjected to corona treatment so that the contact angle with water was 50 ° or less.

  Resin film # 1 is used for the polarizer protective film on the opposite side of the liquid crystal cell, and resin film # 3 is used for the polarizer protective film on the liquid crystal cell side, and an aqueous urethane adhesive (manufactured by Toyo Morton Co., Ltd.) is applied to each corona-treated surface. : ECOAD EL-436A / B) was dispersed in water with a solid content of 10 wt% using a Mayer bar # 8, and these were wet-laminated on both sides of the polarizer. Then, 72Hr was put into a 45 degreeC thermostat, and drying and curing were performed simultaneously. Thereafter, the light release PET release film of the acrylic pressure-sensitive adhesive prepared above was peeled off, and a 25 μm thick layer was laminated on the surface of the protective film (resin film # 3) on the liquid crystal cell side. The obtained polarizing plate pressure-sensitive adhesive sheet was cut into a square having a side of 15 cm so that the angle formed by each side with respect to the absorption axis of the polarizer was 45 °, and was bonded to a glass plate.

  The same procedure as in Example 1 was performed except that the resin film # 2 was used as the polarizer protective film on the side opposite to the liquid crystal cell, and the resin film # 4 was used as the polarizer protective film on the liquid crystal cell side.

(Comparative Example 1)
The same procedure as in Example 1 was performed except that resin film # 3 was used as the polarizer protective film on the side opposite to the liquid crystal cell, and resin film # 3 was used as the polarizer protective film on the liquid crystal cell side.

(Comparative Example 2)
The same procedure as in Example 1 was performed except that resin film # 1 was used as the polarizer protective film on the side opposite to the liquid crystal cell, and resin film # 1 was used as the polarizer protective film on the liquid crystal cell side.

(Comparative Example 3)
The same procedure as in Example 1 was conducted except that resin film # 5 was used as the polarizer protective film on the side opposite to the liquid crystal cell, and resin film # 2 was used as the polarizer protective film on the liquid crystal cell side.

(Heat resistance test)
The test pieces obtained by pasting the polarizing plates of Examples 1 and 2 and Comparative Examples 1 to 3 on a glass plate were allowed to stand for 1000 hours in a 90 ° C. constant temperature bath, and then allowed to stand at room temperature to evaluate high temperature durability.
For the observation of the crack, the taken-out glass-bonded product was left at room temperature and observed until 3 months later. It was observed by visual evaluation, and when the crack did not occur, it was evaluated as “good”, and when the crack was confirmed, it was evaluated as “poor”.
Frame-shaped light leakage was measured from numbers 1 to 9 circled in the plane of the polarizing plate as shown in Fig. 1 by placing two glass-bonded samples heat-tested under the above conditions in a crossed Nicol state. Points were determined and the parallel light transmittance was measured. The measurement point was set to be 5 mm from the end except for the numeral 5 surrounded by a circle at the center. The measurement apparatus measured the Y value using the chromaticity measurement mode of a spectrophotometer (device name: RETS-2000 manufactured by Otsuka Electronics Co., Ltd.). The average value of the points that are likely to change at the position after the test (circled numbers 2, 4, 6, 8) and the points that are less likely to change (numbers 1, 3, 5, 7, and 9 circled) The difference was used as an evaluation scale.

(Moisture resistance test)
The test pieces obtained by pasting the polarizing plates of Examples 1 and 2 and Comparative Examples 1 to 3 on a glass plate were left in a constant temperature and humidity chamber at 60 ° C. and 95% RH for 1000 hours, and then left at room temperature for high temperature and high humidity. Durability was evaluated.
For the observation of fading, the Y value before and after the durability test was measured and the difference was evaluated. The measurement device used the chromaticity measurement mode of a spectrophotometer (device name: RETS-2000 manufactured by Otsuka Electronics Co., Ltd.).
The results are shown in Table 1.

  The polarizing plate of the present invention can be suitably used as a polarizing plate for a liquid crystal display device requiring high durability.

It is a figure which shows arrangement | positioning of the measurement point with which it uses for the measurement of the frame-shaped light leakage in a heat test.

Claims (3)

A polarizing plate formed by laminating a polarizer protective film on both sides of a polarizer used for bonding to a liquid crystal cell, the polarizer protective film on the opposite side of the liquid crystal cell has a parallel light transmittance of 85% or more, The film has a moisture permeability of 20 to 200 g / m ² / day, a tensile breaking strength of 55 MPa or more, and a tensile breaking elongation of 10% or more. The polarizer protective film on the liquid crystal cell side has a parallel light transmittance of 85% or more and a moisture permeability of 20 A polarizing plate characterized by being a film of up to 200 g / m ² / day and a photoelastic coefficient of 1.0 × 10 ⁻¹¹ Pa ⁻¹ or less.   2. The polarizing plate according to claim 1, wherein the polarizer protective film opposite to the liquid crystal cell is a film made of a polycarbonate resin, a polysulfone resin, a polyether sulfone resin, or a polyester resin.   The polarizing plate according to claim 1 or 2, wherein the polarizer protective film on the liquid crystal cell side is a film made of a norbornene resin, an olefin-maleimide resin, or a polyvinyl acetal resin.