JP2001305345A - Polarizing plate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polarizing plate being excellent in transparency, durability under high temperature and high humidity surroundings, heat resistance and physical strength. SOLUTION: The polarizing plate is characterized by laminating a protective film composed of a norbornene type resin film on at least one surface of a polarizer composed of a polyvinyl alcohol type sheet with adhesion using an aqueous polymer-isocyanate type adhesive.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polarizing plate, and more particularly, to a polarizing plate comprising a polyvinyl alcohol-based (hereinafter abbreviated as PVA-based) sheet and a polarizing plate protective film comprising a norbornene-based resin sheet. The present invention relates to a polarizing plate having excellent transparency, durability under a high temperature and high humidity environment, heat resistance, physical strength, and the like.

[0002]

2. Description of the Related Art In recent years, liquid crystal displays (hereinafter referred to as LCDs) have been developed.
) Is often used for vehicles and portable information devices, and there is a strong demand for the reliability of LCDs in high-temperature and high-temperature and high-humidity environments. Conventionally, LCD
The polarizing plate used for is used by attaching to one or both sides of a liquid crystal cell in which liquid crystal is sealed between two electrode substrates forming a transparent electrode, and a typical structure thereof is a stretch-oriented PVA-based sheet. And a protective film made of triacetyl cellulose (hereinafter abbreviated as TAC) is adhered to one or both sides of a polarizer produced by adsorbing iodine or a dichroic dye.

[0003] TAC as a protective film, as it is, has poor adhesion to a polarizer made of a PVA-based sheet, and is usually treated with alkali-treated TAC (hereinafter referred to as saponified TA).
C). But,
This saponified TAC was found to have the following problems although it had good adhesion to the polarizer. Due to the high water absorption, the degree of polarization decreases in a high-temperature and high-humidity environment, and the transmittance increases due to fading. Under high temperature environment, PV
A force for relaxing the orientation of the A polarizer is generated, and as a result, a large phase difference is generated in the saponified TAC of the protective film due to the stress, and the degree of polarization is reduced.

In order to solve the problems of the TAC and the saponified TAC, various polymer films have been proposed so far as polarizing plate protective films in place of them, but most of these polymer films are hydrophobic. Therefore, the adhesiveness to PVA-based adhesives conventionally used is poor, and it has been difficult to adopt an adhesive method that can be used for conventional TAC or saponified TAC.

For example, in Japanese Patent Application Laid-Open No. Hei 5-212828,
A method has been proposed in which a thermoplastic saturated norbornene resin is used as a protective film, and adhesion with a PVA polarizer is heated and pressed using an acrylic pressure-sensitive adhesive. In this method, the degree of polarization is reduced by a heating operation at the time of adhesion. In addition, there is a problem that not only fading is inevitable, the adhesive strength is insufficient, but also the durability is low, and the conventional manufacturing process cannot be used as it is.

For this reason, in the field of a polarizing plate in which a polarizing plate protective film is bonded and laminated on a PVA-based polarizer, the bonding method and manufacturing process used for conventional TAC and saponified TAC protective films are used as they are. Can,
Development of a low-cost and highly reliable manufacturing method has been demanded.

[0007]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems of the conventional polarizing plate protective film, and to improve transparency, durability in a high-temperature and high-humidity environment, heat resistance, physical strength, and the like. An object of the present invention is to provide a polarizing plate comprising a PVA-based polarizer and a norbornene-based resin protective film laminated thereon.

[0008]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies in order to achieve the above object, and as a result, have found that a polarizing plate protective film comprising a PVA-based polarizer and a norbornene-based resin sheet has been converted to an aqueous polymer-isocyanate-based. By bonding with an adhesive, transparency, durability under high temperature and high humidity environment,
It has been found that a polarizing plate excellent in heat resistance, physical strength and the like can be obtained. The present invention has been completed based on these findings.

Thus, according to the present invention, a protective film made of a norbornene-based resin film is bonded and laminated on at least one surface of a polarizer made of a polyvinyl alcohol-based sheet with an aqueous polymer-isocyanate-based adhesive. Is provided.

Further, according to the present invention, the aqueous polymer
The above-mentioned polarizing plate is provided, wherein the isocyanate-based adhesive is an adhesive obtained by adding an isocyanate having at least two isocyanate groups in a molecule to an aqueous solution or an aqueous emulsion containing polyvinyl alcohol. Is done.

Further, according to the present invention, the isocyanates are at least one compound selected from the group consisting of polyisocyanates, modified polyisocyanates, polymerized polyisocyanates, and blocked polyisocyanates. A polarizing plate according to any one of the above is provided.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail.

1. Polarizer The polarizer used in the present invention is a PV having the function of a polarizer.
There is no particular limitation as long as it is an A-based film or sheet. As a polarizer made of a PVA-based film or sheet, for example, a PVA-iodine-based polarizing film that is uniaxially stretched in a boric acid bath after adsorbing iodine to the PVA film; After diffusion and adsorption, a uniaxially stretched PVA / dye-based polarizing film; PVA
PVA / polyvinylene-based polarizing film having a polyvinylene structure by adsorbing iodine on a film and stretching; PVA / metal-based polarizing film having a PVA film adsorbing a metal such as gold, silver, mercury or iron; And a sodium ultraviolet thiosulfate-treated boric acid solution, a near-ultraviolet polarizing film; a polarizing film having a dichroic dye on the surface and / or inside of a PVA-based film made of modified PVA containing a cationic group in the molecule; No.

The method for producing these PVA-based polarizing films is not particularly limited. For example, a method of stretching a PVA-based film and adsorbing iodine ions; a method of dyeing a PVA-based film with a dichroic dye and then stretching the film. A method of stretching a PVA-based film and then dyeing it with a dichroic dye; a method of printing a dichroic dye on a PVA-based film and stretching; and a method of stretching a PVA-based film and printing a dichroic dye. Can be More specifically, iodine is dissolved in a potassium iodine solution to form higher-order iodine ions, the ions are adsorbed on a PVA film and stretched, and then a bath temperature of 30 to 40% is added to a 1 to 4% boric acid aqueous solution. Or a method of producing a polarizing film by immersion at a temperature of 0.05 ° C., or a boric acid treatment of a PVA film and stretching in a uniaxial direction about 3 to 7 times, and 0.05 to 5%
And a method of immersing in a dichroic dye aqueous solution at a bath temperature of 30 to 40 ° C. to adsorb the dye, drying at 80 to 100 ° C., and heat fixing to produce a polarizing film.

2. Polarizing Plate Protective Film In the present invention, a polarizing plate protective film (hereinafter, referred to as a protective film) is a transparent polymer film having a function as a protective film for a polarizer, and is bonded to one or both surfaces of a polarizer. used. The protective film of the present invention,
It is sufficient that the film is laminated on at least one surface of the polarizer, and a film having high transparency can be provided on the other surface. At least one surface on which the film must be laminated is the surface on the liquid crystal cell side, because the change in retardation cannot be suppressed under the durability test conditions unless the protective film is used.

The norbornene resin used in the present invention is:
It has a norbornane skeleton in its repeating unit. For example, JP-A-3-14882 and JP-A-3-3-188.
22137 and the like. Specific examples of the resin include a hydrogenated product of a ring-opening polymer of a norbornene-based monomer, an addition-type polymer of a norbornene-based monomer, an addition-type copolymer of a norbornene-based monomer and an olefin, and these polymers. Modified products of
These are, for example, ZEONEX, ZEONOR (both are trade names, manufactured by Nippon Zeon Co., Ltd.), ARTON (J
OPTOREZ (trade name, manufactured by Hitachi Chemical Co., Ltd.), APEL (trade name, manufactured by Mitsui Chemicals, Inc.)
It is commercially available as a resin such as (trade name).

The norbornene resin used in the present invention includes:
If desired, an antioxidant such as a phenolic or phosphorus-based antioxidant;
Phenol-based thermal degradation inhibitors; amines and other antistatic agents; aliphatic alcohol esters, polyhydric alcohol partial esters and partial ethers and other lubricants; benzophenone-based UV absorbers, benzotriazole-based UV absorbers, acrylonitrile-based Various additives such as an ultraviolet absorber such as an ultraviolet absorbing line; a leveling agent such as a fluorine-based nonionic surfactant, a special acrylic resin-based leveling agent, and a silicone-based leveling agent may be added.

The norbornene resin used in the present invention is formed into a film by a known method such as a solution casting method or a melt molding method, and is provided as a protective film. In the solution casting method, a bar coater, T-die, doctor knife, Meyer bar,
It can be cast on a resin film, a steel belt, a metal drum, or the like using a comma coater or the like.
Also. Examples of the melt molding method include a method using a T-die, a melt extrusion method such as an inflation method, a calendar method, a hot press method, and an injection molding method.

The thickness of the protective film is usually 5 to 200 μm.
m, preferably 10 to 100 μm. If the thickness of the film is less than 5 μm, not only does the strength decrease, but also the curling increases when a durability test is performed on the polarizing plate. On the other hand, when the thickness exceeds 200 μm, not only the transparency is lowered, but also the moisture permeability becomes small, and there is a problem that water as a solvent of the PVA-based adhesive does not dry.

The surface of the protective film is preferably subjected to a surface treatment before being bonded to the polarizer. Examples of the surface treatment include a corona discharge treatment and an ultraviolet irradiation treatment, and preferably have a wetting index of 45 dyn / cm or more,
More preferably, the surface state should be 50 dyn / cm or more. The wetting index means a critical surface tension according to Zisman, and is measured with a standard wetting reagent based on JIS-K-6768.

3. Aqueous polymer-isocyanate-based adhesive The aqueous polymer-isocyanate-based adhesive used in the present invention is an isocyanate having at least two or more isocyanate groups in a molecule in an aqueous solution containing PVA or an aqueous emulsion containing PVA. Is an adhesive obtained by adding a filler, a filler, a bulking agent, a thickener, a surfactant, a synthetic resin, and an antifoaming agent as required.

The concentration of PVA in the aqueous solution containing PVA or the aqueous emulsion containing PVA is 0.5
Suitably, it is ２０20% by weight. The degree of saponification and molecular weight of PVA are not particularly limited, but those having a degree of polymerization of 200 to 4,000 and a degree of saponification of 80 mol% or more are preferable from the viewpoint of durability. In addition, as the PVA, in addition to unmodified PVA, copolymer-modified PVA, graft-modified PVA, and the like can be used. These may be used alone or in combination of two or more.

The water-soluble polymer component of the adhesive used in the present invention can contain other water-soluble polymers in addition to PVA. Although not particularly limited, preferred water-soluble polymers include cellulose derivatives such as carboxymethylcellulose, hydroxyethylcellulose, hydroxypropylcellulose, and methylcellulose, polyethylene oxide, and starch.

Further, as the aqueous emulsion containing PVA, a PVA aqueous solution is blended with a vinyl acetate polymer aqueous emulsion using PVA as a protective colloid or a vinyl acetate polymer emulsion using no PVA as a protective colloid. Emulsions of vinyl acetate and vinyl acetate homopolymer, as well as copolymer emulsions of vinyl acetate with unsaturated acids such as acrylic acid, maleic acid, fumaric acid, crotonic acid and esters thereof, and copolymers of vinyl acetate and ethylene A copolymer emulsion of vinyl acetate and another monomer copolymerizable therewith, such as an emulsion, a styrene-butadiene copolymer latex, a butadiene-acrylonitrile copolymer latex, a chloroprene latex, a polyacrylate latex, Le rubber latex, polybutadiene latex, polyvinyl chloride emulsions, polyvinylidene chloride emulsions and modified products thereof emulsion,
Modified latex or the like, or a mixture of two or more of these, in which a PVA aqueous solution is blended, or a mixture in which PVA is used as a protective colloid, may be used.

The isocyanate which is another component of the aqueous polymer-isocyanate adhesive of the present invention is not particularly limited as long as it has at least two isocyanate groups in its molecule. Examples of this include polyisocyanates, modified polyisocyanates, polymerized polyisocyanates, and blocked polyisocyanates.

The polyisocyanate is not particularly limited as long as it has two or more NCO groups. For example, toluene diisocyanate (TD
I), 4,4'-diphenylmethane diisocyanate (MDI), 1,5-naphthalenediisocyanate (N
DI), tolidine diisocyanate (TODI), HD
I (hexamethylene diisocyanate), IPDI (isophorone diisocyanate), p-phenylene diisocyanate, transcyclohexane 1,4-diisocyanate, XDI, hydrogenated XDI, hydrogenated MDI, lysine diisocyanate (LDI), tetramethyl xylene diisocyanate (TMXDI), Lysine ester triisocyanate, 1,6,11-undecane triisocyanate, 1,8-diisocyanate-4-isocyanatomethyloctane, 1,3,6-hexamethylene triisocyanate, bicycloheptane triisocyanate, trimethylhexamethylene triisocyanate, Examples include triphenylmethane triisocyanate and polymeric MDI.

The modified polyisocyanate includes urethane modified, allohanate modified, bullet modified, urea modified and isocyanate prepolymer.

The above-mentioned urethane-modified product is defined as having a monomeric polyisocyanate NCO / OH molar ratio of at least 2:
Modified at a ratio of 1 or more,
As the agent, a monomeric polyol such as TMP or glycol is used. These include TMP and TDI adducts, HDI adducts,
There is an IPDI adduct body and the like.

The above-mentioned modified allohanate refers to those having a structure of an NCO terminal having an allohanate bond formed by reaction of urethane with isocyanate, among those formed by a partial reaction between polyisocyanate and polyfunctional hydroxyl.

The urea-modified product refers to a product formed by a partial reaction between a polyisocyanate and an amine compound, having a urea bond formed by the reaction between the isocyanate and the amine and having a terminal NCO group structure.

The above modified bullet is a product formed by a partial reaction of a polyisocyanate and an amine compound or a reaction with water, having a bullet bond and having a terminal NCO structure.

What is the urethane prepolymer? It refers to an isocyanate prepolymer having a terminal NCO group compound obtained by a partial reaction of a polyisocyanate with a hydroxypolyether or hydroxypolyester.

The polymerized polyisocyanate is, for example, Daltosec 3240, Coronate 2031
(All are manufactured by Nippon Polyurethane Industry Co., Ltd., trade names)
It is commercially available.

Further, the blocked isocyanate is obtained by masking the isocyanate group with phenol or the like, and is commercially available, for example, as Coronate AP (trade name, manufactured by Nippon Polyurethane Industry Co., Ltd.).

When the isocyanate is blended with the adhesive of the present invention, it may be blended as it is in an aqueous solution containing PVA or an aqueous emulsion containing PVA, but the isocyanate is uniformly dispersed in water. Is difficult, and furthermore, the isocyanate groups for reacting with PVA by reacting with water are consumed. To avoid them, a method of blending isocyanates with water is almost soluble in water. A method of dispersing using a solvent (for example, toluene, xylene, liquid paraffin, etc.) which shows mutual solubility with isocyanates, and a method of reacting a polyethylene oxide derivative to use it as a self-emulsifying type (Japanese Patent Application Laid-Open No. Sho 56) 143280),
A method of introducing SO ₃ ^- or the like into a molecule and dispersing it in water, an acid solubilization method (Japanese Patent Publication No. 56-15418), a method using the above-described blocked isocyanate, and the like are used. be able to.

4. Adhesion / Lamination Method The polarizer and the protective film of the present invention are adhesively laminated with an aqueous polymer-isocyanate adhesive. The adhesive layer has a coating amount of the adhesive after drying of 0.01 to 20 g / m ² ,
Preferably, it is 0.05 to 10 g / m ² . If the coating amount is less than 0.01 g / m ² , sufficient adhesive strength cannot be obtained, while if it exceeds 20 g / m ² , discoloration of the polarizing plate easily occurs in a moisture resistance test, which is not desirable.

The adhesive layer can be formed by dry lamination,
Either semi-dry lamination or wet lamination is possible. In the case of dry lamination or semi-dry lamination, the concentration of the adhesive coating liquid is adjusted to an appropriate value (for example, 0.
(1 to 50% by weight), applied by a known technique (such as a gravure coater or a microgravure coater), dried with hot air or the like, and adhered. However, when performing wet lamination, it may be dropped before lamination besides the above-mentioned application method.

When the polarizing plate of the present invention is used, for example, as a polarizing film for a liquid crystal display, a norbornene-based resin sheet is bonded as a protective layer to one or both sides of a PVA-based polarizing film. When providing a protective layer on one side,
In order to protect the polarizing film from the temperature around the liquid crystal display, in manufacturing the liquid crystal display, the protective layer is provided outside the polarizing film. In order to maintain the quality of the polarizing film before manufacturing the liquid crystal display, prevent moisture absorption of the polarizing film in the manufacturing process, prevent a decrease in the degree of polarization due to heating, and protect from scratches, it is preferable to attach a protective layer to both surfaces. Note that a protective layer made of a conventionally known material may be provided on one surface.

When the polarizing plate of the present invention is mainly used as a polarizing film for a liquid crystal display, in order to facilitate lamination work on a liquid crystal substrate or a transparent electrode layer, when a protective layer is provided on both surfaces, one of the protective layers is provided. When the protective layer is provided on one side on the protective layer surface, on the surface having no protective layer,
It is preferable to laminate an adhesive layer for bonding a polarizing film. Further, it is preferable that a release film such as release paper or a release film is laminated on the adhesive layer.

The polarizing plate thus obtained has excellent transparency, interlayer adhesive strength, and durability, and has low birefringence, moisture resistance, water resistance, and the like inherent to a norbornene-based resin sheet.
Since it has properties such as heat resistance and physical strength, even if stress due to shrinkage of the polarizer is applied in the durability test, a large retardation does not occur in the protective film and the decrease in the degree of polarization is suppressed. In addition, by using an aqueous polymer-isocyanate adhesive, sufficient adhesive strength can be obtained and the durability of the polarizing plate can be improved, so that it is useful as a polarizing film in various fields.

[0041]

EXAMPLES Hereinafter, the present invention will be described specifically with reference to Examples and Comparative Examples, but the present invention is not limited to only these Examples. In addition,% is a weight basis unless there is particular notice.

The methods for measuring physical properties in the following examples and comparative examples are as follows.

[Test Method] The bias obtained in the Examples and Comparative Examples
After drying the light plate, a square with an evaluation size of 50 mm x 50 mm
And a durability evaluation test is performed on the test piece.
Was. The test conditions were 90 ° C dry and 60 ° C 90% RH.
And observed up to 500Hr each, and the transmittance change before and after the test.
Optical characteristics (under high temperature and high humidity environment)
(Durability and heat resistance). In addition, the transmittance change,
The measurement of the degree of polarization change was performed as follows. -Change in transmittance: Measurement was performed using a spectrophotometer (TC-1800,
Change in transmittance (Durability test) using Tokyo Denshoku Industries Co., Ltd.
Before and after) was measured by a Y value.・ Polarization degree change: Using two polarizing plates, parallel and orthogonal transmission
The percentage was measured, and the degree of polarization was determined by the following equation. Degree of polarization = [(H1−H2) / (H1 + H2)]^1/2  (Where H1 represents the parallel transmittance and H2 represents the orthogonal transmittance.
You. )

[Preparation of Each Member]Fabrication of polarizer  PVA powder stretched film with saponification degree of 99% and thickness of 75μ
Was washed with water at room temperature, and then uniaxially stretched 5 times in the machine direction.
Was. While maintaining the tension of this film, iodine
Aqueous solution consisting of 0.5wt%, potassium iodide 5wt%
And the dichroic dye was adsorbed. In addition, boric acid 10
50% water consisting of 10% by weight and 10% by weight of potassium iodide
Crosslinking treatment was performed with the solution for 5 minutes to obtain a polarizer.

[0045]Preparation of polymer film Norbornene resin film  Norbornene resin (trade name: ARTON, JSR
(Manufactured by Co., Ltd.) in toluene at 35 wt%.
And cast it on a PET process film at 80 ° C for 5 minutes.
After leaving at 20 ° C for 5 minutes and peeling off the process film
Dry at 150 ° C. for 3 minutes. The thickness after drying is 50μ
there were.

[0046]Polycarbonate (PC) film  Commercially available 70μ PC film (Model: C-120-7)
0, Teijin Limited).

[0047]Saponified TAC film  Commercially available 80μ TAC film (trade name: Fujitack
Rear, manufactured by Fuji Photo Film Co., Ltd.).

[0048]Surface treatment of polymer film  Surface of norbornene resin film and PC film
Was subjected to a corona discharge treatment. Surface treated
The wetting index is measured using a wetting indicator for the film.
As a result, in each case, it was 70 dyn / cm or more.

Example 1 A mixture of polymer methylene bisphenyl isocyanate or the like and MDI (diphenylmethane diisocyanate) (polymeric MDI) (main agent / curing agent: KR-3) in an aqueous emulsion of a vinyl acetate polymer containing PVA.
02XT / AP, manufactured by Koyo Sangyo Co., Ltd.) was diluted to 10 wt% with distilled water and applied to the corona-treated surface of the norbornene resin film with a Meyer bar # 8. And wet-laminated with a polarizer while squeezing excess coating solution. This operation was performed on both surfaces of the polarizer, and left in a thermostat at 45 ° C. for 72 hours to dry water as a solvent.

Example 2 A mixture of polymeric methylene bisphenyl isocyanate and the like and MDI (diphenylmethane diisocyanate) (polymeric MDI) in a vinyl acetate polymer aqueous emulsion containing PVA (main agent / curing agent: KR-2)
060 / AP, manufactured by Koyo Sangyo Co., Ltd.) is diluted to 10 wt% with distilled water and applied to the corona-treated surface of the norbornene resin film with a Meyer bar # 8. And wet-laminated with a polarizer while squeezing excess coating solution. This operation was performed on both surfaces of the polarizer, and left in a thermostat at 45 ° C. for 72 hours to dry water as a solvent.

Example 3 A 5 wt% aqueous solution of PVA (Kuraray Povar PVA-117H, manufactured by Kuraray Co., Ltd.) and an isocyanate (EL-4)
36B, manufactured by Toyo Morton Co., Ltd.) was applied to the corona-treated surface of the norbornene resin film with a Meyer bar # 8 at a 7: 1 ratio of an aqueous dispersion prepared by diluting 5 wt% with water. And wet-laminated with a polarizer while squeezing excess coating solution. This operation was performed on both surfaces of the polarizer, and left in a thermostat at 45 ° C. for 72 hours to dry water as a solvent.

Comparative Example 1 A resin layer was formed in the same manner as in Example 1 on the corona-treated film surface of a PC film.

Comparative Example 2 Commercially available PVA (Kuraray Poval PVA-117H, manufactured by Kuraray Co., Ltd.) was applied to a saponified film of TAC (trade name: Fuji Tack Clear, manufactured by Fuji Photo Film Co., Ltd.) of 80 μm. A 5 wt% aqueous solution was applied by a Meyer bar # 8 and wet-laminated. Do this on both sides,
It was left in a thermostat at 45 ° C. for 72 hours to dry water as a solvent.

Next, the durability optical characteristics of the polarizing plates obtained in Examples 1 to 3 and Comparative Examples 1 and 2 were measured in accordance with the test method described above. The results shown in Tables 1 and 2 below were obtained. Obtained.

[Table 1]

[0055]

[Table 2]

As is clear from Tables 1 and 2,
The polarizing plate of the present invention obtained in Examples 1 to 3, Comparative Examples 1 to
90 ° dry, 6 compared to the conventional polarizing plate obtained in 2.
Both the change in transmittance and the change in the degree of polarization under the conditions of 0 ° C. and 90% RH are extremely small, and it can be seen that they have excellent durability optical properties such as heat resistance and durability in a high temperature and high humidity environment.

[0057]

As described above, the polarizing plate of the present invention has
A norbornene-based resin protective film is adhered to and laminated on at least one surface of a PVA-based polarizer with an aqueous polymer-isocyanate-based adhesive. A norbornene-based resin having a low photoelastic constant and low moisture permeability is used as the protective film. By using it, even if stress due to shrinkage of the polarizer is applied in the durability test, a large retardation does not occur in the protective film, not only can the decrease in the degree of polarization be suppressed, but also water intrusion can be prevented. Thus, the moisture resistance of the polarizing plate can be significantly improved. Further, by using the aqueous polymer-isocyanate adhesive, a sufficient adhesive strength can be obtained between the PVA-based polarizer and the protective film, and the durability of the polarizing plate can be improved.

Claims (3)

[Claims] 1. A polarizing plate, wherein a protective film made of a norbornene-based resin film is adhered and laminated on at least one surface of a polarizer made of a polyvinyl alcohol-based sheet with an aqueous polymer-isocyanate-based adhesive. 2. The aqueous polymer-isocyanate adhesive is an adhesive obtained by adding an isocyanate having at least two isocyanate groups in a molecule to an aqueous solution or an aqueous emulsion containing polyvinyl alcohol. The polarizing plate according to claim 1, wherein: 3. The method according to claim 1, wherein the isocyanate is at least one compound selected from the group consisting of a polyisocyanate, a modified polyisocyanate, a polymerized polyisocyanate, and a blocked polyisocyanate. The polarizing plate of the above.