KR100882169B1 - Process for manufacturing polarizing plate, polarizing plate, optical film and image display - Google Patents

Abstract

A method for producing a polarizing plate having a transparent protective film formed on at least one surface of the polarizer through an adhesive layer, wherein the adhesive is applied to the surface forming the adhesive layer of the transparent protective film and / or the surface forming the adhesive layer of the polarizer. After forming the layer, when the transparent protective film and the polarizer are continuously attached through the adhesive layer, an aqueous liquid is present on the attachment surface. For this reason, a polarizing plate having uniform polarization characteristics and excellent durability can be obtained.

Polarizer, transparent protective film, polarizing plate, optical film, image display device

Description

Manufacturing method of a polarizing plate, a polarizing plate, an optical film, and an image display apparatus {PROCESS FOR MANUFACTURING POLARIZING PLATE, POLARIZING PLATE, OPTICAL FILM AND IMAGE DISPLAY}

Field of technology

The present invention relates to a method for producing a polarizing plate. Moreover, this invention relates to the polarizing plate obtained by the said manufacturing method. Image display such as a flat panel display such as a liquid crystal display device (hereinafter abbreviated as LCD), an electroluminescence display device (hereinafter abbreviated as ELD), a PDP, or the like as an optical film obtained by stacking the polarizing plate alone or as a laminate thereof. The device can be formed.

Background

In general, a polarizing plate for a flat panel display, in particular, a polarizing plate used in LCD, mainly uses a polyvinyl alcohol-based film having a thickness of 70 µm or more as a raw material. Moreover, in order to obtain sufficient optical characteristics as an LCD, the polarizing plate extends | stretches the PVA system film containing dichroic materials, such as iodine, and attaches and produced the transparent protective film to this is used preferably. The polyvinyl alcohol polarizer is easily contracted because it is produced by stretching. In addition, the PVA-based film is very easy to deform under humid conditions, in particular using a hydrophilic polymer. In addition, since the mechanical strength of the film itself is weak, there is a problem that the film is broken. Therefore, the polarizing plate which adhered the transparent protective films, such as the triacetyl cellulose which saponified on both sides or one side of the polarizer, and supplemented the intensity | strength was used. The said polarizing plate was manufactured by attaching a polarizer and a transparent protective film with an adhesive agent. As an adhesive for polarizing plates used for adhesion | attachment of the said polarizer and a transparent protective film, an aqueous adhesive is preferable, For example, the polyvinyl alcohol-type adhesive agent which mixed the crosslinking agent with the polyvinyl alcohol aqueous solution was used.

Along with the high definition and high functionality of LCDs, the uniformity and quality of screens were required. In addition, according to the diversification of the use environment, high heat resistance, heat and humidity resistance, water resistance and the like are also required. In recent years, LCDs have also been required to be thinner and lighter due to portable functions. In view of such a required characteristic of LCD, various polarizing plates for LCD have required high performance and high functions such as uniformity, high heat resistance, moisture heat resistance, water resistance, and thinning as polarizers.

As a method of attaching a polarizer and a transparent protective film and manufacturing a polarizing plate, there are the following methods. For example, in one method, after first apply | coating an adhesive agent solution to the single side | surface of a polarizer, a transparent protective film is affixed on the single side | surface of a polarizer by sticking a transparent protective film. Next, after apply | coating an adhesive agent solution to the other surface of a polarizer, a transparent protective film is affixed on the other surface of a polarizer by attaching a transparent protective film. Thereby, the polarizing plate with which the transparent protective film adhered respectively through the adhesive bond layer on both surfaces of a polarizing plate is produced. Moreover, the said adhesive solution may apply | coat to both a polarizer and a transparent protective film, and the case where it apply | coats directly to a transparent protective film. Moreover, in another method, a transparent protective film is arrange | positioned on both surfaces of a polarizer, respectively, and supplying an adhesive solution between layers of a polarizer and a transparent protective film (refer patent document 1), or forming the adhesive layer of a transparent protective film. With the adhesive applied to the surface forming the adhesive layer of the surface or / and the polarizer to form an adhesive layer, the transparent protective film and the polarizer are continuously passed between the pair of rolls and the rolls. The method of sticking and manufacturing a polarizing plate was also proposed.

However, in the above-mentioned conventional manufacturing method, there exists a problem which a faulty external appearance of stripe shape arises during attachment of a polarizer and a transparent protective film. This stripe appearance defect affects, among other things, the optical uniformity among the highly demanding properties of the polarizing plate. For this reason, the LCD was not able to cope with the improvement of screen uniformity and quality with high definition and high functionality of LCD. The stripe appearance defect means that a stripe-shaped stripe is seen in a reflection state parallel to the absorption axis direction of the polarizing plate obtained by attaching a transparent protective film. As a characteristic of a stripe, it is a shape like a groove cut into a record board at a pitch of 1 to 2 mm.

As above, a polarizer is used by the polarizing plate which reinforced intensity | strength with the transparent protective film. However, conventionally, the polyvinyl alcohol-type adhesive agent may peel at the interface of a polarizer and a transparent protective film under humidification conditions. It is considered that the polyvinyl alcohol-based resin, which is the main component of the adhesive, is a water-soluble polymer, and the dissolution of the adhesive may occur under the condensation.

 In order to solve such a problem, it was proposed that the heat-and-moisture resistance and water resistance improved by using the resin solution containing the polyvinyl alcohol-type resin containing acetoacetyl group and a crosslinking agent as a PVA-type adhesive agent (refer patent document 2). However, in the adhesive agent for polarizing plates of the aspect of patent document 2, water resistance was not enough. Moreover, it was not enough in the point which has a stripe appearance defect.

Moreover, after forming an adhesive bond layer on a polarizer or a transparent protective film, and controlling the contact angle of the said adhesive bond layer to below a predetermined angle by humidification, the method of manufacturing a polarizing plate by attaching a polarizer and a transparent protective film is proposed. (Refer patent document 3 and patent document 4). However, the method of patent document 3 and patent document 4 is difficult to control, and also a manufacturing process is complicated and cannot be called a realistic manufacturing method.

Patent Document 1: Japanese Patent Application Laid-Open No. 11-179871

Patent Document 2: Japanese Patent Application Laid-Open No. 7-198945

Patent Document 3: Japanese Patent Application Laid-Open No. 7-306315

Patent Document 4: Japanese Patent Application Laid-Open No. 7-306316

Disclosure of the Invention

Problems to be Solved by the Invention

This invention is made | formed in view of such a situation, and an object of this invention is to provide the method of efficiently manufacturing the polarizing plate which has uniform polarization characteristic and is excellent in durability.

Moreover, an object of this invention is to provide the polarizing plate obtained by the said manufacturing method. Moreover, it aims at providing the optical film which laminated | stacked the said polarizing plate, and image display apparatuses, such as LCD and ELD using the said polarizing plate and optical film.

Means to solve the problem

MEANS TO SOLVE THE PROBLEM As a result of earnestly examining in order to solve the said subject, it discovered that the said objective can be achieved by the manufacturing method of the polarizing plate shown below, and came to complete this invention. That is, this invention is as follows.

1. As a manufacturing method of the polarizing plate in which the transparent protective film was formed in at least one surface of the polarizer through the adhesive bond layer,

When the adhesive layer is formed by applying the adhesive to the surface forming the adhesive layer of the transparent protective film or / and the surface forming the adhesive layer of the polarizer, and then continuously attach the transparent protective film and the polarizer through the adhesive layer,

Aqueous liquid is present in an adhesion surface, The manufacturing method of the polarizing plate characterized by the above-mentioned.

2. A polarizer is a polyvinyl alcohol-based polarizer, and a transparent protective film is a cellulose-type transparent protective film, The manufacturing method of the said polarizing plate of 1 characterized by the above-mentioned.

3. Thickness of polarizer is 35 micrometers or less, The manufacturing method of the said polarizing plate of 1 or 2 characterized by the above-mentioned.

4. Adhesive is polyvinyl alcohol-type adhesive, The manufacturing method of polarizing plate in any one of said 1-3 characterized by the above-mentioned.

5. Polyvinyl alcohol-type adhesive agent is polyvinyl alcohol-type adhesive agent which has acetoacetyl group, The manufacturing method of the said 4 polarizing plate characterized by the above-mentioned.

6. Adhesive contains crosslinking agent, The manufacturing method of polarizing plate in any one of said 1-5 characterized by the above-mentioned.

7. Crosslinking agent is methylol compound, The manufacturing method of polarizing plate of 6 characterized by the above-mentioned.

8. Thickness of adhesive bond layer is 30-300 nm, The manufacturing method of the polarizing plate in any one of said 1-7 characterized by the above-mentioned.

9. Viscosity of aqueous solution is 0.1-10 cP, The manufacturing method of the polarizing plate in any one of said 1-8 characterized by the above-mentioned.

10. Aqueous liquid is water, The manufacturing method of the polarizing plate in any one of said 6-9 characterized by the above-mentioned.

11. Aqueous liquid is an aqueous solution which melt | dissolves a crosslinking agent, The manufacturing method of the polarizing plate in any one of said 1-9 characterized by the above-mentioned.

12. The crosslinking agent is a methylol compound, The manufacturing method of the said polarizing plate of 11 characterized by the above-mentioned.

13. Aqueous liquid is supplied to the attachment surface of a transparent protective film and a polarizer, The manufacturing method of the polarizing plate in any one of said 1-12 characterized by the above-mentioned.

14. An adhesive is applied only to the transparent protective film side, and an aqueous liquid is present on the adhesion surface by supplying an aqueous liquid on the adhesive layer formed by this application, wherein the polarizing plate according to any one of 1 to 12 above. Method of preparation.

15. The manufacturing method of the polarizing plate in any one of said 1-12 which makes an aqueous liquid exist in an adhesion surface by apply | coating an adhesive agent only to a transparent protective film side, and supplying an aqueous liquid to a polarizer side.

16. The manufacturing method of the polarizing plate in any one of said 1-12 which makes an aqueous liquid exist in an adhesion surface by apply | coating an adhesive agent only to a polarizer side and supplying an aqueous liquid to a transparent protective film side.

17. When manufacturing a transparent protective film and a polarizer continuously through an adhesive bond layer, the aqueous solution is supplied to an adhesion surface just before attachment, The manufacturing method of the polarizing plate in any one of said 1-16 characterized by the above-mentioned.

18. The polarizing plate obtained by the manufacturing method in any one of said 1-17.

19. One or more polarizing plates of said 18 were laminated | stacked, The optical film characterized by the above-mentioned.

20. The polarizing plate of said 18 or the optical film of said 19 is used, The image display apparatus characterized by the above-mentioned.

Effects of the Invention

In the manufacturing method of the polarizing plate of the said invention, before attaching a polarizer and a transparent protective film with an adhesive agent, the transparent protective film or polarizer which apply | coated the adhesive agent to at least one surface of a transparent protective film or polarizer, and formed an adhesive bond layer is used. Manufacture. Moreover, when attaching a transparent protective film and a polarizer, an aqueous liquid exists in the adhesion surface of a transparent protective film and a polarizer, ie, the said adhesive bond layer. Thereby, the polarizing plate which suppressed external defects, especially stripe shape nonuniformity, is obtained. Such a polarizing plate has a uniform polarization characteristic in that a stripe appearance defect is suppressed, and can provide an image display device such as high performance LCD, ELD, and the like. In addition, the manufacturing method of the present invention is suitable for continuous production, it is possible to efficiently produce a polarizing plate. Moreover, the polarizing plate excellent in durability is obtained by adding an aqueous liquid to an adhesive bond layer. Especially when an adhesive agent is a polyvinyl alcohol-type adhesive agent which has an acetoacetyl group, and contains methylol melamine as a crosslinking agent, durability improves further.

The detailed mechanism of why the manufacturing method of the present invention is effective in suppressing the stripe appearance defect occurring in the polarizing plate is not clear. In the conventional manufacturing method as described above, it is inferred that the adhesive solution having a high viscosity on the surface of the polarizer or the transparent protective film is brought into contact with the polarizer and the transparent protective film at the time of attachment, so that some physical force is applied. In this invention, it is thought that the said physical factor was excluded by presence of an aqueous liquid.

Surprisingly, in the production method of the present invention, it was also found that the adhesive having a high reactivity has a greater effect than the adhesive having a low reactivity in suppressing the stripe appearance defect. The mechanism is not necessarily obvious. Since the low reactivity adhesive generally has high solubility in water, it is redissolved in the aqueous liquid to which the adhesive bond layer formed on the surface of a transparent protective film or a polarizer was once added. And it is thought that it is because the viscosity of an addition aqueous solution system is increased in the vicinity of the opposite polarizer to which it adheres, or the transparent protective film surface. Therefore, the manufacturing method of the present invention is particularly effective for highly reactive adhesives.

Implement the invention  Best form for

A polarizer is not specifically limited, Various things can be used. As a polarizer, dichroic materials, such as iodine and a dichroic dye, are made to adsorb | suck to hydrophilic polymer films, such as a polyvinyl alcohol-type film, a partially formalized polyvinyl alcohol-type film, and an ethylene vinyl acetate copolymer partial saponification film, for example. And polyene-oriented films such as uniaxially stretched, dehydrated products of polyvinyl alcohol, and dehydrochloric acid treated products of polyvinyl chloride. Among these, the polarizer which consists of a polyvinyl alcohol-type film and dichroic substances, such as iodine and a dichroic dye, is preferable.

As a polyvinyl alcohol-type film, what was formed into a film by arbitrary methods, such as the casting | flow_spreading method, the casting method, and the extrusion method which cast-forms the undiluted | stock solution which melt | dissolved polyvinyl alcohol-type resin in water or an organic solvent, can be used suitably. About 100-5000 are preferable and, as for the polymerization degree of polyvinyl alcohol-type resin, 1400-4000 are more preferable.

The polarizer which uniaxially stretched the polyvinyl alcohol-type film with iodine etc. can be manufactured by the following method, for example.

In the dyeing step, the polyvinyl alcohol-based film is immersed in a dyeing bath at about 20 to 70 ° C. to which iodine is added for about 1 to 20 minutes to adsorb iodine. Iodine concentration in a dyeing bath is about 0.1-1 weight part per 100 weight part of water normally. In the dyeing bath, an adjuvant such as potassium iodide, lithium iodide, sodium iodide, zinc iodide, aluminum iodide, lead iodide, copper iodide, barium iodide, calcium iodide, tin iodide, titanium iodide and the like is 0.02 to 20 parts by weight. Preferably, you may add 2-10 weight part. These additives are particularly preferable for increasing the dyeing efficiency. In addition to the water solvent, a small amount of an organic solvent compatible with water may be contained.

In addition, the polyvinyl alcohol-based film may be swelled for about 0.1 to 10 minutes in a water bath or the like before dyeing in an aqueous solution containing iodine or a dichroic dye. In addition to washing the polyvinyl alcohol-based film with water, the contamination of the polyvinyl alcohol-based film with the antiblocking agent can be washed, and swelling of the polyvinyl alcohol-based film also has the effect of preventing irregularities such as uneven dyeing.

The dyed polyvinyl alcohol-based film can be crosslinked as necessary. The composition of the crosslinking aqueous solution to be subjected to the crosslinking treatment is usually about 1 to 10 parts by weight of a crosslinking agent such as boric acid, borax, glyoxal, glutaraldehyde or the like alone or per 100 parts by weight of water. The concentration of the crosslinking agent is determined in consideration of the balance between the optical properties and the shrinkage of the polarizing plate caused by the stretching force generated in the polyvinyl alcohol-based film.

0.05 to 15 weight% of auxiliary agents, such as potassium iodide, lithium iodide, sodium iodide, zinc iodide, aluminum iodide, lead iodide, copper iodide, barium iodide, calcium iodide, tin iodide, titanium iodide, etc. Preferably, you may add 0.5-8 weight%. These additives are especially preferable at the point which acquires the in-plane uniform characteristic of a polarizer. The temperature of aqueous solution is about 20-70 degreeC normally, Preferably it is the range of 40-60 degreeC. Although immersion time is not specifically limited, Usually, about 1 second-about 15 minutes, Preferably they are 5 second-10 minutes. In addition to the water solvent, a small amount of an organic solvent compatible with water may be contained.

The total draw ratio of the polyvinyl alcohol-based film is about 3 to 7 times the original length, and preferably 5 to 7 times. When the total draw ratio exceeds 7 times, the film is likely to break. Stretching may be carried out after dyeing with iodine, may be performed while dyeing or crosslinking, or may be dyed with iodine after stretching. The stretching method, the number of stretching, and the like are not particularly limited and may be performed only in any one step. Moreover, you may implement in multiple times at the same process.

Further, in the polyvinyl alcohol-based film subjected to the iodine adsorption orientation treatment, the water temperature is about 10 to 60 ° C., preferably about 30 to 40 ° C., and about 1 to 1 to an aqueous solution of iodide such as potassium iodide having a concentration of 0.1 to 10% by mass. The process of dipping for minutes can be formed. In an iodide aqueous solution, you may add adjuvant, such as zinc sulfate and a zinc chloride. Moreover, in the polyvinyl alcohol-type film which performed the iodine adsorption orientation treatment, the drying process of about 1 minute-about 10 minutes can be formed in a water washing process and about 20-80 degreeC.

Although the thickness in particular of these polarizers is not restrict | limited, Usually, it is about 5-80 micrometers. If the thickness of a polarizer is thin, in the manufacturing process of a polarizing plate, the moisture in a polarizer will become easy to volatilize in the drying process at the time of sticking with a transparent protective film. Therefore, the elongation of a polarizer is reduced, and a remarkable stripe appearance defect arises easily. This phenomenon is remarkable as the thickness of the polarizer becomes thinner, but according to the manufacturing method of the polarizing plate of the present invention, even when the thickness of the polarizer is 35 µm or less, and even 20 µm or less, occurrence of a stripe appearance defect can be suppressed.

As a transparent polymer or film material which forms a transparent protective film, although a suitable transparent material can be used, what is excellent in transparency, mechanical strength, thermal stability, water barrier property, etc. is used preferably. As a material which forms the said transparent protective film, For example, Polyester type polymers, such as polyethylene terephthalate and a polyethylene naphthalate, Cellulose-type polymers, such as cellulose diacetate and a cellulose triacetate, Acrylic polymers, such as polymethylmethacrylate, Styrene-type polymers, such as polystyrene and an acrylonitrile styrene copolymer (AS resin), a polycarbonate polymer, etc. are mentioned. Further, polyethylene, polypropylene, polyolefins having a cyclo- or norbornene structure, polyolefin-based polymers such as ethylene-propylene copolymers, amide-based polymers such as vinyl chloride-based polymers, nylon and aromatic polyamides, imide-based polymers, and sulfides Phone polymer, polyether sulfone polymer, polyether ether ketone polymer, polyphenylene sulfide polymer, vinyl alcohol polymer, vinylidene chloride polymer, vinyl butyral polymer, arylate polymer, polyoxymethylene polymer, Epoxy-based polymers, blends of the polymers, and the like can also be cited as examples of the polymer forming the transparent protective film. The transparent protective film can also be formed as a cured layer of thermosetting or ultraviolet curable resins such as acrylic, urethane, acrylic urethane, epoxy, and silicone.

Furthermore, the polymer film described in JP 2001-343529 A (WO01 / 37007), for example, a thermoplastic resin having a substituted and / or unsubstituted imide group in the (A) side chain, and a (B) side chain, And / or a resin composition containing a thermoplastic resin having unsubstituted phenyl and nitrile groups. As a specific example, the film of the resin composition containing the alternating copolymer which consists of isobutylene and N-methyl maleimide, and an acrylonitrile styrene copolymer is mentioned. The film can use the film which consists of mixed extrusion products of a resin composition, etc. Since these films have a small retardation and a small photoelastic coefficient, problems such as unevenness due to deformation of the polarizing plate can be solved, and since the moisture permeability is small, the humidification durability is excellent.

Although the thickness of a protective film can be determined suitably, it is about 1-500 micrometers generally from the point of workability, thinness, etc., such as strength and handleability. 1-300 micrometers is especially preferable, and 5-200 micrometers is more preferable. It is preferable that the thickness of a transparent protective film is 50 micrometers or less.

Moreover, it is preferable that a transparent protective film does not have coloring as much as possible. Therefore, the film thickness direction represented by Rth = [(nx + ny) / 2-nz] · d (where nx and ny are the main refractive indices in the film plane, nz is the refractive index in the film thickness direction and d is the film thickness). The protective film whose retardation value of -90nm-+ 75nm is used preferably. By using those whose phase difference value (Rth) of the thickness direction is -90 nm-+75 nm, the coloring (optical coloring) of the polarizing plate resulting from a transparent protective film can be almost eliminated. The thickness direction retardation value Rth is more preferably -80 nm to +60 nm, particularly preferably -70 nm to +45 nm.

As a transparent protective film, the cellulose transparent protective film which consists of cellulose polymers, such as a triacetyl cellulose, is preferable from a polarizing characteristic, durability, etc .. In particular, a triacetyl cellulose film is preferable. Moreover, when forming a transparent protective film on both sides of a polarizer, the protective film which consists of the same polymer material may be used for both surfaces, and the protective film which consists of another polymer material, etc. may be used.

Easiness of adhesion can be given to the surface which adhere | attaches with the polarizer of a transparent protective film. Examples of the easy adhesion treatment include a dry treatment such as a plasma treatment, a corona treatment, a chemical treatment such as an alkali treatment, and a coating treatment for forming an adhesion agent layer. Among these, the coating process which forms an easily bonding agent layer is preferable. Various easily bonding materials, such as a polyol resin, a polycarboxylic acid resin, and a polyester resin, can be used for formation of an adhesive agent layer. Moreover, it is preferable that the thickness of an adhesive agent layer is about 0.01-10 micrometers normally, More preferably, it is about 0.05-5 micrometers, Especially about 0.1-1 micrometer.

The surface which did not adhere | attach the polarizer of the said transparent protective film may be the thing which performed the process for the purpose of a hard-coat layer, an antireflection process, sticking prevention, and diffusion or antiglare.

The hard coat treatment is carried out for the purpose of preventing scratches on the surface of the polarizing plate, and for example, a method of adding a cured film having excellent hardness and slipping properties, such as acrylic or silicone type, to the surface of the transparent protective film. And the like can be formed. The antireflection treatment is performed for the purpose of preventing reflection of external light on the surface of the polarizing plate, and can be achieved by forming an antireflection film or the like according to the prior art. In addition, a sticking prevention process is performed in order to prevent adhesion with an adjacent layer.

In addition, antiglare treatment is carried out for the purpose of preventing external light from reflecting off the surface of the polarizing plate and impairing the visibility of the polarizing plate transmitted light. For example, blending of roughening method or transparent fine particles by sandblasting or embossing It can form by providing a fine uneven structure to the surface of a transparent protective film by a suitable method, such as a system. As microparticles | fine-particles contained in formation of the said surface fine concavo-convex structure, electroconductive which consists of silica, alumina, titania, zirconia, tin oxide, indium oxide, cadmium oxide, antimony oxide etc. with an average particle diameter of 0.5-20 micrometers may be used, for example. Transparent microparticles | fine-particles, such as organic microparticles | fine-particles which consist of an inorganic type microparticle, a crosslinked or uncrosslinked polymer, etc. are used. When forming a surface fine uneven structure, the usage-amount of microparticles | fine-particles is generally about 2-70 weight part with respect to 100 weight part of transparent resin which forms a surface fine uneven structure, and 5-50 weight part is preferable. The antiglare layer may also serve as a diffusion layer (visual magnification function or the like) for diffusing the polarized plate transmitted light to enlarge the time and the like.

The antireflection layer, the sticking prevention layer, the diffusion layer, the antiglare layer, and the like can be formed on the transparent protective film itself, and can also be formed separately from the transparent protective film as an optical layer. have.

Although the adhesive agent used for attachment of a polarizer and a transparent protective film is not specifically limited, A polyvinyl alcohol-type adhesive agent is used preferably. As a polyvinyl alcohol-type adhesive agent, what contains polyvinyl alcohol-type resin and a crosslinking agent is used normally. However, when using the aqueous solution containing a crosslinking agent as an aqueous liquid, you may contain a crosslinking agent in an adhesive agent, and you do not need to contain it.

As polyvinyl alcohol-type resin, polyvinyl alcohol resin and the polyvinyl alcohol resin which has an acetoacetyl group are mentioned. The polyvinyl alcohol resin which has an acetoacetyl group is a polyvinyl alcohol-type adhesive agent which has a highly reactive functional group, and since durability of a polarizing plate improves, it is preferable.

-올레핀, (메스)아릴술폰산(소다), 술폰산소다(모노알킬말레이트), 디술폰산소다알킬말레이트, N-메틸올아크릴아미드, 아크릴아미드알킬술폰산알칼리염, N-비닐피롤리돈, N-비닐피롤리돈 유도체 등을 들 수 있다. 이들 폴리비닐알코올계 수지는 일종을 단독으로 또는 2 종 이상을 병용할 수 있다. Polyvinyl alcohol-type resin is polyvinyl alcohol obtained by saponifying polyvinyl acetate; Its derivatives; Moreover, saponified copolymer of vinyl acetate and the copolymer which has a copolymerizability; The modified polyvinyl alcohol which made acetal-ized, urethane-ized, etherified, grafted, phosphate esterified etc. of polyvinyl alcohol is mentioned. Examples of the monomers include unsaturated carboxylic acids such as maleic anhydride, fumaric acid, crotonic acid, itaconic acid, and (meth) acrylic acid and esters thereof; Ethylene, propylene, etc.

-Olefin, (meth) arylsulfonic acid (soda), sodium sulfonic acid (monoalkyl maleate), disulfonic acid sodium alkyl maleate, N-methylol acrylamide, acrylamide alkyl sulfonic acid alkali salt, N-vinylpyrrolidone, N And vinylpyrrolidone derivatives. These polyvinyl alcohol-type resins can be used individually by 1 type or in combination of 2 or more types.

Although the said polyvinyl alcohol-type resin is not specifically limited, From an adhesive point, an average degree of polymerization is about 100-3000, Preferably it is 500-3000, An average saponification degree is about 85-100 mol%, Preferably it is 90-100 mol%. .

The polyvinyl alcohol-based resin containing an acetoacetyl group is obtained by reacting the polyvinyl alcohol-based resin with diketene by a known method. For example, a polyvinyl alcohol-based resin is dispersed in a solvent such as acetic acid and diketene is added thereto, and a polyvinyl alcohol-based resin is previously dissolved in a solvent such as dimethylformamide or dioxane. The method of adding diketene, etc. are mentioned. Moreover, the method of directly contacting diketene gas or liquid diketene with polyvinyl alcohol is mentioned.

If the acetoacetyl group modification degree of the polyvinyl alcohol-type resin containing an acetoacetyl group is 0.1 mol% or more, there will be no restriction | limiting in particular. If it is less than 0.1 mol%, the water resistance of the adhesive layer is insufficient and inadequate. Acetoacetyl group modification degree becomes like this. Preferably it is about 0.1-40 mol%, More preferably, it is 1-20 mol%, Especially preferably, it is 2-7 mol%. When content of acetoacetyl group exceeds 40 mol%, the reaction point with a crosslinking agent becomes small, and the effect of improving water resistance is small. Acetoacetyl group denaturation is the value measured by NMR.

As a crosslinking agent, what is used for a polyvinyl alcohol-type adhesive agent can be used without a restriction | limiting in particular. The compound which has 2 or more functional groups which have reactivity with the said polyvinyl alcohol-type resin can be used. For example, Alkylene diamine which has two alkylene groups and amino groups, such as ethylenediamine, triethylenediamine, and hexamethylenediamine; Tolylene diisocyanate, hydrogenated tolylene diisocyanate, trimethylol propane tolylene diisocyanate adduct, triphenylmethane triisocyanate, methylene bis (4-phenylmethane triisocyanate, isophorone diisocyanate and their ketooxime block or phenol block) Isocyanates such as ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, glycerin di or triglycidyl ether, 1,6-hexanediol diglycidyl ether, trimethylolpropane triglycidyl ether, di Epoxy, such as glycidyl aniline and diglycidyl amine; Monoaldehydes, such as formaldehyde, acetaldehyde, propionaldehyde, and butylaldehyde; Glyoxal, malondialdehyde, succinic aldehyde, glutadialdehyde, and maledialdehyde Dialdehydes such as phthaldialdehyde, methylol urea, methylol mel Amino-formaldehyde resins such as min, alkylated methylol urea, alkylated methylolated melamine, acetguanamine, benzoguanamine and formaldehyde condensate, and also 2, such as sodium, potassium, magnesium, calcium, aluminum, iron and nickel. And salts of trivalent metals or trivalent metals and oxides thereof, and among these, amino-formaldehyde resins, in particular, methylol compounds having methylol groups are preferable.

The compounding quantity of the said crosslinking agent is about 0.1-35 weight part normally with respect to 100 weight part of polyvinyl alcohol-type resins, Preferably it is 10-25 weight part. Within this range, a polarizing plate having uniform polarization characteristics and excellent durability can be obtained.

On the other hand, in order to improve durability more, a crosslinking agent can be mix | blended in more than 46 weight part with respect to 100 weight part of polyvinyl alcohol-type resins. In particular, when using polyvinyl alcohol-type resin containing an acetoacetyl group, it is preferable to use the usage-amount of a crosslinking agent more than 30 weight part. By mix | blending a crosslinking agent more than 30 weight part in the range of 46 weight part or less, water resistance can be improved remarkably. The compounding quantity of a crosslinking agent is more preferable in the said range, It is 31 weight part or more, More preferably, it is 32 weight part or more, Especially 35 weight part or more is preferable. On the other hand, when the compounding quantity of a crosslinking agent increases too much, reaction of a crosslinking agent advances in a short time and it exists in the tendency for an adhesive agent to gelatinize. As a result, the possible use time (pot life) as an adhesive becomes extremely short, and industrial use becomes difficult. In view of this, the blending amount of the crosslinking agent is preferably 46 parts by weight or less, more preferably 45 parts by weight or less, particularly 40 parts by weight or less.

The said adhesive (including the case containing a polyvinyl alcohol-type adhesive agent and a crosslinking agent) is used normally as aqueous solution. Although aqueous solution concentration does not have a restriction | limiting in particular, Considering applicability | paintability, leaving stability, etc., it is 0.1-15 weight%, Preferably it is 0.5-10 weight%, More preferably, it is about 0.5-2 weight%. When the solution concentration is high, the viscosity is high, whereby stripe irregularities are likely to occur. When solution concentration becomes too low, a viscosity will become low and applicability will worsen.

Moreover, the said adhesive agent can further mix | blend coupling agents, such as a silane coupling agent and a titanium coupling agent, various tackifiers, a ultraviolet absorber, antioxidant, a heat resistant stabilizer, and a hydrolysis stability stabilizer.

Moreover, in the manufacturing method of a polarizing plate, when using the thing containing the crosslinking agent more than 30 weight part and 46 weight part or less with respect to 100 weight part of polyvinyl alcohol-type resin containing an acetoacetyl group as said adhesive agent, It is preferable to prepare the adhesive within 4 hours before applying the adhesive. If the adhesive which mix | blended the crosslinking agent with the polyvinyl alcohol-type resin containing an acetoacetyl group is left to stand for a long time, it will gelatinize. Therefore, it is preferable to make adhesive preparation into a short time as possible before apply | coating an adhesive agent. It is preferable to prepare an adhesive within 4 hours before applying the adhesive. It is more preferable within 3 hours, and it is especially preferable to carry out within 30 minutes.

In the manufacturing method of the polarizing plate of this invention, an adhesive agent is formed by first apply | coating an adhesive agent to the surface which forms the adhesive bond layer of a transparent protective film, and / or the surface which forms the adhesive bond layer of a polarizer. The thickness of the adhesive layer affects the water resistance and the heat-and-moisture resistance, and the thicker the adhesive layer is, the higher the durability is. However, in the case of thickening the adhesive layer, a solution having a high viscosity is required in the manufacturing process, and therefore, some physical stress is applied to the PVA polarizer, resulting in uniformity as a polarizer, in particular, generation of a stripe appearance defect. It is preferable that the thickness of an adhesive bond layer is 30-300 nm from such a viewpoint. The thickness of the said adhesive bond layer becomes like this. More preferably, it is 60-250 nm. If it is less than 30 nm, application | coating may become difficult and an external defect may arise easily. On the other hand, when it exceeds 300 nm, it is easy to produce an external fault, and also it is not preferable also from a heat resistant point.

Application | coating of the said adhesive agent may be performed by any of a transparent protective film and a polarizer, and may be performed by both. It is preferable to perform application | coating of the said adhesive so that thickness after drying may be about 30-300 nm.

The coating operation is not particularly limited, and various means such as a roll method, a spray method, and a dipping method can be adopted. After apply | coating an adhesive agent, a drying process is performed and the adhesive bond layer which consists of an application dry layer is formed. Drying temperature is about 5-150 degreeC, Preferably it is about 30-120 degreeC, 120 seconds or more, More preferably, it is 300 seconds or more.

It is preferable that the said adhesive agent manages the temperature from preparation to application | coating. By controlling the temperature of the adhesive, the water resistance can be further improved. It is preferable to make management temperature of an adhesive agent into the range of 30-50 degreeC. More preferably, it is 30-45 degreeC, More preferably, it is 30-40 degreeC. 30 degreeC or more is preferable at the point of water resistance. On the other hand, when it exceeds 50 degreeC, since it becomes easy to gelatinize immediately after mixing a crosslinking agent, it becomes difficult to use as an adhesive agent. In particular, temperature control of an adhesive agent is effective when using what contains a crosslinking agent more than 30 weight part and 46 weight part or less with respect to 100 weight part of polyvinyl alcohol-type resin containing an acetoacetyl group.

In addition, as mentioned above, when using the thing containing a crosslinking agent exceeding 30 weight part and 46 weight part or less with respect to 100 weight part of polyvinyl alcohol-type resins containing an acetoacetyl group as said adhesive agent, the said adhesive agent is used. It is preferable to carry out the preparation within 4 hours before applying the adhesive. In order to carry out from preparation of an adhesive agent to application | coating in a short time within 4 hours, the preparation process of an adhesive agent can be put in a part of a series of process of the manufacturing process of a polarizing plate, or it can be performed by arrange | positioning a suitable preparation apparatus.

Next, in the manufacturing method of this invention, a transparent protective film and a polarizer are adhered continuously by an adhesive bond layer. An adhesive bond layer is previously formed in the surface of at least one of a transparent protective film or a polarizer.

The attachment method is not particularly limited. For example, the method of letting a transparent protective film and a polarizer pass between a pair of roll continuously through an adhesive bond layer is mentioned. Such a method is shown, for example in FIGS. 1 and 2. FIG. 1: adhere | attaches the transparent protective film 2 which formed the adhesive bond layer 3 together through the roll R together on the single side | surface of the polarizer 1, and is the same to the other side of the polarizer 1 after that. It is a case where the transparent protective film 2 which formed the adhesive bond layer 3 is adhere | attached. On the other hand, FIG. 2 is a case where it attaches by making the transparent protective film 2 which formed the adhesive bond layer 3 on both surfaces of the polarizer 1 pass through roll R together.

Roll R does not have a restriction | limiting in particular if it is attachable by roll pressure, when the transparent protective film 2 which formed the polarizer 1 and the adhesive bond layer 3 passes through a pair of rolls. For example, laminate nip rolls are used. Moreover, the material of a roll is not specifically limited, either, A rubber | gum or a metal may be sufficient.

Although the conveyance speed of a transparent protective film and a polarizer (at least one of which an adhesive bond layer is formed) is not restrict | limited, Usually, it is about 0.03-0.6 m / s, Preferably it is about 0.08-0.5 m / s, More preferably, Is about 0.11 to 0.34 m / s.

In the manufacturing method of this invention, when affixing the said transparent protective film and a polarizer through an adhesive bond layer, an aqueous liquid exists in an adhesion surface.

As the aqueous liquid, for example, water is used. Pure water is preferable as this water. In addition, as an aqueous solution, the aqueous solution which melt | dissolves a crosslinking agent is used. As a crosslinking agent, the crosslinking agent according to the kind of adhesive agent is used. When a polyvinyl alcohol-based adhesive agent is used, a methylol compound is preferable as a crosslinking agent. Although content of a crosslinking agent is not specifically limited, Usually, it is 40 weight% or less, Preferably it is 5-40 weight%, More preferably, it is 10-35 weight%. Moreover, when using the aqueous solution containing a crosslinking agent as an aqueous liquid, since the quantity of a crosslinking agent is more effective than when it contains in an adhesive agent at least, it should just be 2-40 weight%, and it is preferable that it is 4-35 weight%. Moreover, when using the aqueous solution containing a crosslinking agent as an aqueous liquid, it is not necessary to add to a crosslinking agent in an adhesive solution, and the pot life of an adhesive agent can be improved significantly. It is effective when using the polyvinyl alcohol-type resin containing the acetoacetyl group which has a highly reactive functional group as said adhesive agent.

The viscosity of the aqueous solution is usually 0.1 to 10 cP, preferably 0.5 to 5 cP. The viscosity of the said aqueous liquid is the value measured by the method as described in an Example. If it is less than 0.1 cP, application | coating may become difficult, On the other hand, when it exceeds 10 cP, an external defect will generate | occur | produce easily.

Although the supply amount of an aqueous liquid is suitably adjusted according to a conveyance speed etc., it is about 0.5-3.4 ml / s normally, Preferably it is 0.5-1.7 ml / s. The supply amount of the aqueous liquid can be appropriately adjusted according to the width of the raw film.

When the said aqueous liquid exists in the adhesion surface at the time of attaching a transparent protective film and a polarizer through an adhesive bond layer, the supply method in particular is not restrict | limited. For example, an aqueous liquid can be supplied with respect to the adhesion surface of a transparent protective film and a polarizer. If the adhesive layer is supplied immediately before the aqueous liquid is attached to the adhered surface, the adhesive layer does not come into contact with the aqueous liquid until just before the adhesion, which is preferable in that durability of the adhesive and stripe irregularities are unlikely to occur.

Moreover, an aqueous liquid can be guide | induced to an adhesion surface simultaneously with conveyance by supplying to the transparent protective film or polarizer (at least one adhesive agent layer is formed) conveyed.

In this invention, it is preferable to make an aqueous liquid exist in an adhesion surface by apply | coating an adhesive agent only to the transparent protective film side, and supplying an aqueous liquid on the adhesive bond layer formed by this application | coating. It is especially preferable when a transparent protective film is affixed on both surfaces of a polarizer in the state like FIG. In the example of FIG. 2, the adhesive layer is formed on the polarizer side because the adhesive may be stretched. Moreover, for the same reason, it is preferable to perform supply of an aqueous liquid on the adhesive bond layer formed in the transparent protective film.

Moreover, when an adhesive agent is apply | coated only to the transparent protective film side and an adhesive bond layer is formed, aqueous solution can be supplied to a polarizer side. According to this method, similarly to the above, the adhesive layer does not come into contact with the aqueous liquid until immediately before adhesion. Moreover, when the moisture content of the inside or the surface of a polarizer becomes small, it contributes greatly to generation | occurrence | production of a stripe appearance defect. On the other hand, when the moisture content of a polarizer is made high, stripe appearance defects will hardly arise. When the aqueous liquid is supplied to the polarizer side, the moisture content of the polarizer is increased until it is guided to the sticking roll, and generation of the stripe appearance defect can be more effectively suppressed.

Moreover, when an adhesive agent is apply | coated only to the polarizer side and an adhesive bond layer is formed, it is preferable to supply an aqueous liquid to the transparent protective film side. According to this method, similarly to the above, the adhesive layer does not come into contact with the aqueous liquid until immediately before adhesion. In addition, supply of the aqueous liquid to a transparent protective film is possible for simultaneous attachment of a transparent protective film to both surfaces of a polarizer, and can be performed without an adhesive etc. being advantageous on a manufacturing apparatus.

When continuously attaching a transparent protective film and a polarizer through the said adhesive bond layer, it is preferable to supply an aqueous liquid just before adhesion with respect to the surface to attach. Immediately before the adhesion, it means to adhere in a short time within about 30 seconds after supplying the aqueous liquid. The shorter this time is, the more preferable it is, and it is preferable to perform the adhesion within 5 seconds, preferably within 2 seconds, more preferably within 1 second, and particularly within 0.5 seconds after supplying the aqueous liquid. When the time until adhesion is too long, when supplying an aqueous liquid on an adhesive bond layer, it becomes easy to become a cause of a nonuniformity in that an adhesive melt | dissolves more than necessary. Moreover, when supplying an aqueous liquid on a transparent protective film or a polarizer, since moisture content becomes large too much, nonuniformity becomes easy after drying. In addition, when supplying an aqueous liquid just before attachment in this way, the supply place is not restrict | limited depending on which side an adhesive bond layer is formed, Either one side or both sides of a transparent protective film side, a polarizer side may be sufficient. Moreover, you may use the method of forming a liquid lump in an adhesion part and letting it pass right before adhesion | attachment.

In FIG. 1, FIG. 2, the aqueous liquid 4 is supplied with respect to the adhesion surface of the adhesive bond layer 3 formed in the transparent protective film 2, and the polarizer 1. As shown in FIG. In FIG. 1, FIG. 2, the aqueous liquid may exist between a pair of roll R, and the setting location of the aqueous liquid 4 can be changed suitably. In FIG. 1, FIG. 2, although the supply point of the aqueous liquid 4 is one with respect to a set of conveyance film (combination of a polarizer and a transparent protective film), the supply point of the aqueous liquid 4 can be formed in multiple places. Moreover, you may provide the supply location of the aqueous liquid 4 with respect to each conveyance film. As a supply method of an aqueous liquid, a dropping method, an application | coating method, a spraying method, etc. are mentioned, for example. In these supply methods, a nozzle, a spray, a coater, etc. can be selected suitably and used.

Moreover, when an aqueous liquid exists too much in the adhesion surface of a transparent protective film and a polarizer and leaks from the edge part of an adhesion surface, an excess amount is removed by a suction nozzle etc., or it inclines to the center part of an adhesion surface by an air nozzle, etc., It is possible to prevent contamination due to leakage of the aqueous liquid.

In the same manner as described above, the polarizer and the transparent protective film are attached to a roll laminator or the like through the adhesive layer while the aqueous solution is present, followed by a drying step. Drying temperature is about 5-150 degreeC, Preferably it is 30-120 degreeC, 120 seconds or more, Preferably it is 300 seconds or more.

The polarizing plate of this invention can be used as an optical film laminated | stacked with the other optical layer in practical use. Although there is no limitation in particular about the optical layer, For example, formation of a liquid crystal display device, such as a reflecting plate, a semi-transmissive plate, a retardation plate (including wavelength plates, such as 1/2 or a quarter), a visual compensation film, etc. The optical layer used for can use 1 layer or 2 or more layers. In particular, a reflection type polarizing plate or a semi-transmissive polarizing plate in which a reflecting plate or a transflective reflecting plate is laminated on the polarizing plate of the present invention, an elliptical polarizing plate or circular polarizing plate in which a retardation plate is further laminated on the polarizing plate, and a visual compensation film is further laminated on the polarizing plate. The wide viewing angle polarizing plate which consists of, or the flat tube plate which laminated | stacked the brightness improving film further on the polarizing plate is preferable.

The reflective polarizer is formed by forming a reflective layer on the polarizer, and is used to form a liquid crystal display device of a type that reflects and displays incident light from the viewing side (display side). This is advantageous in that the display device can be thinner. Formation of a reflective polarizing plate can be performed by a suitable method, such as the method of laying a reflective layer which consists of metals etc. on the single side | surface of a polarizing plate through a transparent protective layer etc. as needed.

As a specific example of a reflection type polarizing plate, the thing which formed the reflection layer by laying the foil and vapor deposition film which consisted of reflective metals, such as aluminum, on the single side | surface of the matt protective transparent protective film as needed. Moreover, what contains microparticles | fine-particles in the said transparent protective film to make surface fine concavo-convex structure, and has a reflective layer of a fine concavo-convex structure on it, etc. are mentioned. The above-described reflective layer of the finely concave-convex structure has the advantage of preventing incident light from being diffused by diffused reflection by diffuse reflection, and suppressing the variation of light and dark. Moreover, the transparent protective film containing microparticles | fine-particles also has the advantage etc. which can spread | diffuse when incident light and its reflected light transmit it, and can suppress a light and shade nonuniformity more. The formation of the reflective layer of the finely uneven structure reflecting the surface finely uneven structure of the transparent protective film is, for example, transparent protection of the metal by a suitable method such as a deposition method such as a vacuum deposition method, an ion plating method, a sputtering method, or a plating method. It can carry out by the method of directly laying on the surface of a layer.

Instead of the method of directly applying to the transparent protective film of the polarizing plate, the reflecting plate may be used as a reflecting sheet or the like formed by forming a reflecting layer on a suitable film according to the transparent film. In addition, since the reflective layer is usually made of a metal, the use mode in which the reflective surface is covered with a transparent protective film, a polarizing plate, or the like prevents the reduction of the reflectance due to oxidation, and furthermore, the long-term duration of the initial reflectance or the protective layer. It is preferable at the point of avoiding separate laying.

The semi-transmissive polarizing plate can be obtained by forming a semi-transmissive reflective layer such as a half mirror that reflects light through the reflective layer and transmits the above. The semi-transmissive polarizing plate is usually formed on the back side of the liquid crystal cell, and when using a liquid crystal display device or the like in a relatively bright atmosphere, reflects incident light from the viewing side (display side) to display an image, and is relatively dark. In the atmosphere, a liquid crystal display device of a type for displaying an image or the like can be formed using a built-in light source such as a backlight built in the backside of the transflective polarizing plate. That is, the transflective polarizing plate can save energy of using a light source such as a backlight in a bright atmosphere, and is useful for forming a liquid crystal display device of the type that can be used using a built-in light source even in a relatively dark atmosphere.

An elliptical polarizing plate or circular polarizing plate in which a retardation plate is further laminated on the polarizing plate will be described. A retardation plate or the like is used to change linearly polarized light into elliptical polarization or circularly polarized light, to change elliptical polarization or circularly polarized light into linearly polarized light, or to change the polarization direction of linearly polarized light. In particular, a so-called quarter wave plate (also referred to as λ / 4 plate) is used as the phase difference plate for converting linearly polarized light into circularly polarized light or for converting circularly polarized light into linearly polarized light. A half wave plate (also called a λ / 2 plate) is usually used when changing the polarization direction of linearly polarized light.

The elliptical polarizing plate is effectively used for compensating (preventing) the coloration (blue or yellow color) caused by the birefringence of the liquid crystal layer of the super twist nematic (STN) type liquid crystal display device to perform monochrome display without the coloration. In addition, it is preferable to control the three-dimensional refractive index because it can compensate (prevent) the coloration generated when the screen of the liquid crystal display device is viewed in the oblique direction. The circular polarizing plate is effectively used, for example, in aligning the color tone of an image of a reflective liquid crystal display device in which an image is displayed in color, and also has a function of antireflection. Specific examples of the retardation plate described above include birefringence formed by stretching a film made of a suitable polymer such as polycarbonate, polyvinyl alcohol, polystyrene, polymethyl methacrylate, polypropylene or other polyolefins, polyarylates, and polyamides. The thing which supported the orientation film of a film, a liquid crystal polymer, and the orientation layer of a liquid crystal polymer as a film, etc. are mentioned. The retardation plate may have a suitable retardation according to the purpose of use, for example, for the purpose of compensating coloring or vision due to birefringence of various wavelength plates and liquid crystal layers, or by laminating two or more kinds of retardation plates. The optical properties such as phase difference may be controlled.

In addition, said elliptical polarizing plate and reflective elliptical polarizing plate laminate | stack a polarizing plate or a reflective polarizing plate, and a phase difference plate by a suitable combination. Such elliptical polarizing plates and the like can be formed by laminating them sequentially in a manufacturing process of a liquid crystal display device so as to be a combination of a (reflective) polarizing plate and a retardation plate. It is excellent in stability, lamination | workability, etc. of quality, and there exists an advantage which can improve manufacturing efficiency, such as a liquid crystal display device.

The visual compensation film is a film for enlarging a viewing angle so that an image may be seen comparatively clearly, even if the screen of a liquid crystal display device is seen from a slightly inclined direction rather than perpendicular to a screen. As such a visual compensation retardation plate, it consists of the thing which supported alignment layers, such as a liquid crystal polymer, on orientation films, such as a retardation film and a liquid crystal polymer, a transparent base material, etc., for example. A conventional retardation plate is a polymer film having birefringence uniaxially stretched in the plane direction thereof, whereas a retardation plate used as a visual compensation film is a polymer film having a birefringence biaxially stretched in the plane direction or uniaxially stretched in the plane direction and thickness The bidirectional stretched film like the polymer which has birefringence which controlled the refractive index of the thickness direction extended also in the direction, the diagonal oriented film, etc. are used. As the diagonally oriented film, for example, a heat-shrink film is adhered to the polymer film, and the polymer film is stretched and / or shrunk under the action of the shrinkage force by heating, or the diagonally oriented liquid crystal polymer is mentioned. . The raw material polymer of the retardation plate is the same as the polymer described in the above retardation plate, and is used for the purpose of preventing the coloring due to the change of the viewing angle based on the phase difference by the liquid crystal cell, and the expansion of the viewing angle with good visibility. Appropriate ones can be used.

Further, in view of achieving a wide viewing angle with good visibility, an optical compensation retardation plate supporting an optically anisotropic layer composed of an alignment layer of a liquid crystal polymer, particularly an oblique alignment layer of a discotic liquid crystal polymer, as a triacetylcellulose film can be preferably used. .

The polarizing plate with a polarizing plate and a brightness enhancing film is usually formed on the back side of the liquid crystal cell and used. The brightness enhancement film exhibits a property of reflecting linearly polarized light on a predetermined polarization axis or circularly polarized light in a predetermined direction when natural light is incident due to a backlight such as a liquid crystal display device or reflection from the back side, and other light is transmitted. The polarizing plate laminated | stacked with the polarizing plate injects light from light sources, such as a backlight, and acquires the transmitted light of a predetermined polarization state, and reflects the light other than the said predetermined polarization state without transmitting. In addition, the light reflected from the surface of the brightness enhancing film is inverted through a reflecting layer or the like formed on the back side thereof, and reincident to the brightness enhancing film, and a part or all of the light is transmitted as light in a predetermined polarization state to transmit light of the brightness enhancing film. The brightness can be improved by increasing the amount of light and increasing the amount of light that can be used for liquid crystal display image display by supplying polarized light that is hardly absorbed by the polarizer. That is, when light is incident on the back side of the liquid crystal cell through a backlight or the like without using the brightness enhancement film, light having a polarization direction that does not coincide with the polarization axis of the polarizer is almost absorbed by the polarizer and transmitted through the polarizer. I never do that. That is, although it changes also with the characteristic of the polarizer used, about 50% of light is absorbed by a polarizer, and the quantity of light which can be used for a liquid crystal image display etc. decreases by that much, and an image becomes dark. The brightness enhancement film repeats reflecting light having a polarization direction absorbed by the polarizer once in the brightness enhancement film without incident on the polarizer, and inverting it through a reflective layer or the like formed on the back side and reentering the brightness enhancement film, Since only the polarization direction in which the polarization direction of the light reflected and inverted between the polarization directions can pass through the polarizer is transmitted through the luminance enhancement film and is supplied to the polarizer, light such as a backlight is efficiently applied to the image display of the liquid crystal display device. Can be used, and the screen can be brightened.

A diffusion plate may be formed between the brightness enhancing film and the reflective layer. The light in the polarization state reflected by the brightness enhancement film is directed to the reflective layer or the like, but the diffuser plate provided uniformly diffuses the light passing therethrough and at the same time eliminates the polarization state and becomes a non-polarization state. In other words, the diffusion plate returns the polarized light to the original natural light state. The light in this non-polarization state, that is, in the natural light state, is directed to the reflection layer or the like, is reflected through the reflection layer or the like, and passes through the diffuser plate again and is reincident to the brightness enhancement film. Thus, by forming a diffuser plate that returns the polarization to the original natural light state between the brightness enhancing film and the reflective layer, the brightness of the display screen is maintained, while the brightness unevenness of the display screen is reduced, and a uniform and bright screen is provided. Can provide. By forming such a diffuser plate, it is considered that the first incident light can appropriately increase the number of repetitions of reflection and provide a uniform and bright display screen with the diffuser function of the diffuser plate.

As the brightness enhancing film, for example, a multilayer thin film of a dielectric material or a multilayer stack of thin film films having different refractive index anisotropy, which exhibits a characteristic of transmitting other linearly polarized light with a predetermined polarization axis and reflecting other light, cholesteric As supporting the alignment film of the liquid crystal polymer and the alignment liquid crystal layer on the film substrate, suitable ones such as those exhibiting the characteristics of reflecting either circularly polarized light of left rotation or right rotation and transmitting other light can be used.

Therefore, in the luminance improvement film of the type which permeate | transmits the linearly polarized light of the said predetermined polarization axis, it can transmit efficiently, restraining the absorption loss by a polarizing plate, by making the transmitted light into a polarizing plate as it is. On the other hand, in the luminance-enhancing film of the type which transmits circularly polarized light like a cholesteric liquid crystal layer, although it can also be made incident on a polarizer as it is, in view of suppressing absorption loss, the circularly polarized light is linearly polarized through a phase difference plate, It is preferable to make it incident. In addition, by using a quarter wave plate as the retardation plate, circularly polarized light can be converted into linearly polarized light.

A phase difference plate which functions as a quarter wave plate in a wide wavelength range in a visible range, etc. is a phase difference layer which shows a phase difference characteristic different from the phase difference layer which functions as a quarter wave plate with respect to pale light of wavelength 550nm, for example For example, it can obtain by the method of superimposing the retardation layer which functions as a 1/2 wave plate. Therefore, the phase difference plate arrange | positioned between a polarizing plate and a brightness improving film may consist of one layer or two or more phase difference layers.

In addition, also in the cholesteric liquid crystal layer, by combining two or three or more layers in combination with different reflection wavelengths, it is possible to obtain the reflection of circularly polarized light in a wide wavelength range in the visible region or the like. Accordingly, transmission circularly polarized light in a wide wavelength range can be obtained.

Moreover, the polarizing plate may consist of what laminated | stacked the polarizing plate and 2 or 3 or more optical layers like the said polarization split type polarizing plate. Therefore, the reflective elliptically polarizing plate, the semi-transmissive elliptically polarizing plate, etc. which combined said reflective polarizing plate, semi-transmissive polarizing plate, and retardation plate may be sufficient.

Although the optical film which laminated | stacked the said optical layer on the polarizing plate can also be formed by the method of laminating | stacking separately, one by one in the manufacturing process of a liquid crystal display device, etc., what was previously laminated and made into the optical film is excellent in quality stability, assembly work, etc. There exists an advantage which can improve manufacturing processes, such as a liquid crystal display device. Suitable lamination means, such as an adhesion layer, can be used for lamination. In the case of adhering the polarizing plate or the other optical film, the optical axis thereof can be set at an appropriate placement angle in accordance with a desired phase difference characteristic or the like.

The adhesive layer for adhering with other members, such as a liquid crystal cell, can also be formed in the above-mentioned polarizing plate and the optical film in which one or more layers were laminated | stacked. The pressure-sensitive adhesive for forming the pressure-sensitive adhesive layer is not particularly limited, but for example, an acrylic polymer, a silicone polymer, a polyester, a polyurethane, a polyamide, a polyether, a fluorine-based or a rubber-based polymer may be appropriately selected and used. have. In particular, an acrylic adhesive having excellent optical transparency, exhibiting proper wettability and cohesiveness and adhesive adhesion characteristics, and excellent weather resistance, heat resistance and the like can be preferably used.

In addition to the above, in view of prevention of foaming or peeling phenomenon due to moisture absorption, reduction of optical properties due to thermal expansion difference, prevention of warping of liquid crystal cell, and also formation of a high quality and durable liquid crystal display device, The adhesive layer which has a low rate and excellent heat resistance is preferable.

The pressure-sensitive adhesive layer may be, for example, applied to resins of natural or synthetic materials, in particular, pressure-sensitive adhesive layers such as fillers, pigments, colorants and antioxidants made of tackifying resins, glass fibers, glass beads, metal powders and other inorganic powders. You may contain the additive added. Moreover, the adhesion layer etc. which contain microparticles | fine-particles and show light diffusivity may be sufficient.

Laying of the adhesion layer to the single side | surface or both surfaces of a polarizing plate or an optical film can be performed by a suitable method. As an example, about 10 to 40 weight% of the adhesive solution which melt | dissolved or disperse | distributed or disperse | distributed a base polymer or its composition in the solvent which consists of a single substance or mixture of suitable solvents, such as toluene and ethyl acetate, is prepared, The method of laying out directly on a polarizing plate or an optical film by appropriate development methods, such as a coating system, or the method of forming an adhesion layer on a separator according to the above, and transferring it on a polarizing plate or an optical film, etc. are mentioned.

The pressure-sensitive adhesive layer may be formed on one side or both sides of a polarizing plate or an optical film as an overlapping layer such as another composition or type. Moreover, when formed in both surfaces, it can also be set as adhesive layers, such as a composition, a kind, or thickness different from both surfaces of a polarizing plate or an optical film. The thickness of an adhesion layer can be suitably determined according to a use purpose, adhesive force, etc., Generally, it is 1-500 micrometers, 5-200 micrometers is preferable, and 10-100 micrometers is especially preferable.

About the exposed surface of an adhesion layer, a separator is temporarily affixed and covered for the purpose of the contamination prevention, etc. until it is used for practical use. Thereby, contact with an adhesion layer can be prevented in a usual handling state. As the separator, except for the above thickness conditions, for example, a plastic film, a rubber sheet, a paper, a cloth, a nonwoven fabric, a net, a foam sheet, a metal foil, a laminate such as a laminate thereof, and a silicone-based or long-chain alkyl-based compound as necessary. And conventionally appropriate ones such as those coated with an appropriate release agent such as fluorine or molybdenum sulfide can be used.

Moreover, in this invention, in each layer, such as a polarizer, a transparent protective film, or an optical film which form said polarizing plate, and an adhesion layer, for example, a salicylic acid ester type compound, a benzophenol type compound, a benzotriazole type compound, or a cyan The thing which gave ultraviolet absorbing ability by the method of processing with ultraviolet absorbers, such as a noacrylate type compound and a nickel complex salt type compound, etc. may be sufficient.

The polarizing plate or optical film of this invention can be used suitably for formation of various apparatuses, such as a liquid crystal display device. Formation of a liquid crystal display device can be performed according to the prior art. That is, the liquid crystal display device is generally formed by assembling a component such as a liquid crystal cell, a polarizing plate or an optical film, and an illumination system as appropriate, and mounting a driving circuit, but in the present invention, the polarizing plate according to the present invention is used. Or it will not specifically limit except the point which uses an optical film, and can follow conventionally. Also about a liquid crystal cell, an arbitrary type thing, such as a TN type, STN type, (pi) type, can be used, for example.

A suitable liquid crystal display device, such as a liquid crystal display device in which a polarizing plate or an optical film is disposed on one side or both sides of a liquid crystal cell, or a backlight or reflecting plate used in an illumination system, can be formed. In that case, the polarizing plate or optical film by this invention can be provided in the one side or both sides of a liquid crystal cell. When forming a polarizing plate or an optical film in both sides, they may be the same and may differ. In the formation of the liquid crystal display device, for example, a diffuser plate, an antiglare layer, an antireflection film, a protective plate, a prism array, a lens array sheet, a light diffusion plate, a backlight or the like and a suitable component in one or two layers are appropriately positioned. You can place more than that.

Next, an organic electro luminescence apparatus (organic EL display apparatus) is demonstrated. In general, an organic EL display device forms a light emitting body (organic electroluminescent light emitting body) by sequentially stacking a transparent electrode, an organic light emitting layer, and a metal electrode on a transparent substrate. Here, the organic light emitting layer is a laminate of various kinds of organic thin films, for example, a laminate of a hole injection layer made of a triphenylamine derivative or the like and a light emitting layer made of a fluorescent organic solid such as anthracene, or such a light emitting layer and a pedestal. The structure which has various combinations, such as the laminated body of the electron injection layer which consists of a rylene derivative, etc., or these laminated bodies of a hole injection layer, a light emitting layer, and an electron injection layer, was known.

In the organic EL display device, by applying a voltage to the transparent electrode and the metal electrode, holes and electrons are injected into the organic emission layer, and energy generated by recombination of these holes and electrons excites the fluorescent material, and the excited fluorescent material is It emits light on the principle of emitting light when returning to the ground state. The mechanism of intermediate recombination is the same as that of a general diode, and as can be expected from this point, the current and the luminescence intensity exhibit strong nonlinearity accompanied by rectification with respect to the applied voltage.

In the organic EL display device, at least one electrode must be transparent in order to extract light emitted from the organic light emitting layer, and a transparent electrode formed of a transparent conductor such as indium tin oxide (ITO) is usually used as an anode. On the other hand, in order to facilitate electron injection and increase luminous efficiency, it is important to use a small material having a work function for the cathode, and metal electrodes such as Mg-Ag and Al-Li are usually used.

In the organic EL display device having such a configuration, the organic light emitting layer is formed of a very thin film having a thickness of about 10 nm. For this reason, the organic light emitting layer also transmits light almost completely like the transparent electrode. As a result, the light incident on the surface of the transparent substrate at the time of non-luminescence, and transmitted through the transparent electrode and the organic light emitting layer and reflected by the metal electrode again goes out to the surface side of the transparent substrate, so that when viewed from the outside, The display surface looks like a mirror.

In an organic EL display device comprising an organic electro luminescence emitter comprising a transparent electrode on the front side of the organic light emitting layer that emits light by application of a voltage and a metal electrode on the back side of the organic light emitting layer, the transparent electrode While forming a polarizing plate on the surface side of, a retardation plate can be formed between these transparent electrodes and a polarizing plate.

Since the retardation plate and the polarizing plate have a function of polarizing light incident from the outside and reflected by the metal electrode, there is an effect that the mirror surface of the metal electrode is not visually recognized by the polarization action. In particular, if the phase difference plate is constituted by a quarter wave plate and the angle formed between the polarization direction of the polarizing plate and the phase difference plate is adjusted to? / 4, the mirror surface of the metal electrode can be completely shielded.

That is, only the linearly polarized light component transmits external light incident on the organic EL display device by the polarizing plate. This linearly polarized light is generally elliptically polarized by the retardation plate, but in particular, the retardation plate is a quarter wave plate, and when the angle formed by the polarization direction of the polarizing plate and the retardation plate is? / 4, it is circularly polarized light.

The circularly polarized light penetrates the transparent substrate, the transparent electrode, and the organic thin film, is reflected by the metal electrode, and then passes through the organic thin film, the transparent electrode, and the transparent substrate, and becomes linearly polarized again on the retardation plate. And since this linearly polarized light is orthogonal to the polarization direction of a polarizing plate, it cannot pass through a polarizing plate. As a result, the mirror surface of a metal electrode can be shielded completely.

Example

EMBODIMENT OF THE INVENTION Hereinafter, the Example etc. which show a structure and effect of this invention concretely are demonstrated. In addition, in each case, a part and% are basis of weight unless there is particular notice.

(Method for Measuring Viscosity of Aqueous Liquid)

Under the condition of 23 ° C, the viscosity at shear rate 82000 (1 / s) was measured using a viscosity measuring apparatus (Rheometer Rheostress1 manufactured by Thermo Haake).

(Measuring Method of Thickness of Adhesive Layer)

It measured by cross-sectional observation by SEM.

(Production of Polarizer A)

The polyvinyl alcohol (PVA) film of thickness 80micrometer of average polymerization degree 2400 and saponification degree 99.9 mol% was immersed for 60 second in 25 degreeC pure water, and swelled, and uniaxially stretched to 2 times the draw ratio in a flow direction. Subsequently, the film was immersed in an aqueous solution having a concentration of 5% of iodide / potassium iodide (weight ratio = 1/10) and stretched so as to have a total draw ratio of 2.5 times. It extended | stretched until the total draw ratio tripled in aqueous solution of. Then, it extended | stretched so that the total draw ratio might be 5.5 times in aqueous solution of the potassium iodide concentration of 5 weight% of 25 degreeC, and wash | cleaned in pure water. Then, it dried for 3 minutes in 40 degreeC oven, and obtained the polarizer A of thickness 30micrometer.

(Production of Polarizer B)

In the above (production of polarizer A), a polarizer B having a thickness of 19 µm was obtained in the same manner as described above, except that a PVA film having a thickness of 50 µm having an average polymerization degree of 2400 and a saponification degree of 99.9 mol% was used as the PVA film.

(Transparent protective film)

A triacetyl cellulose (TAC) film having a thickness of 40 μm was used.

Example 1

(Preparation of Adhesive)

To 100 parts of PVA-based resin (average degree of polymerization: 1200, degree of saponification: 98.5 mol%, degree of AA modification: 5 mol%, (denoted by AA modified PVA in Table 1)) containing acetoacetyl (AA) group, 20 parts of methylol melamine was melt | dissolved in pure water under the temperature condition of 30 degreeC, and the aqueous solution which adjusted to 0.5% of solid content concentration was prepared. This was used as an adhesive under the temperature conditions of 30 degreeC.

(Production a of Polarizing Plate a)

The adhesive was applied to one side of the transparent protective film with a die coater. Application | coating of the adhesive agent was performed after 30 minutes from the preparation. Then, it dried for 3 minutes at 50 degreeC, and formed the adhesive bond layer whose thickness after drying is 31 nm.

Subsequently, as shown in FIG. 2, the said TAC film with an adhesive bond layer was affixed on the both sides of the polarizer A with a thickness of 30 micrometers with a roller, supplying the pure water of viscosity 1cP (23 degreeC). The conveyance speed of the film was 0.25 m / s, and the supply amount of pure water was 0.80 ml / s. The supply point of pure water was performed so that it might become a transparent protective film shape (position to time for adhesion for 0.5 second). Then, it dried for 6 minutes at 55 degreeC, and produced the polarizing plate.

Examples 2-4

In Example 1 (preparation of the adhesive), a polarizing plate was obtained in the same manner as in Example 1 except that the concentration of the adhesive was changed as shown in Table 1. The thickness of an adhesive bond layer is as showing in Table 1.

Examples 5-12

In (Preparation of adhesive) of Example 1, the polarizing plate was obtained like Example 1 except having changed the kind of crosslinking agent used for an adhesive agent, and the density | concentration of an adhesive agent as shown in Table 1. The thickness of an adhesive bond layer is as showing in Table 1.

Examples 13-16

In (Preparation of adhesive) of Example 1, the resin used for an adhesive agent was changed to polyvinyl alcohol-type resin (average degree of polymerization: 1200, saponification degree: 98.5 mol%), and the density | concentration of an adhesive agent was changed as shown in Table 1. Except having used this thing, it carried out similarly to Example 1, and obtained the polarizing plate. The thickness of an adhesive bond layer is as showing in Table 1.

Example 17

In the preparation of the polarizing plate of Example 1, a polarizing plate was obtained in the same manner as in Example 1 except that an aqueous solution containing 5% by weight of methylolmelamine having a viscosity of 3 cP (23 ° C) was used instead of pure water. The thickness of an adhesive bond layer is as showing in Table 1.

Examples 18-20

In (Preparation of adhesive) of Example 1, it carried out similarly to Example 1 except not having used the crosslinking agent for the adhesive agent, and using the aqueous solution shown in Table 1 instead of pure water in (Preparation of a polarizing plate) of Example 1. To obtain a polarizing plate. The thickness of an adhesive bond layer is as showing in Table 1.

Example 21

In Example 3, the polarizing plate was obtained like Example 3 except not having used a crosslinking agent for the adhesive agent. The thickness of an adhesive bond layer is as showing in Table 1.

Examples 22-24

In Example 3, the polarizing plate was obtained like Example 3 except having not used the crosslinking agent for the adhesive agent, and using the aqueous solution shown in Table 1 instead of pure water. The thickness of an adhesive bond layer is as showing in Table 1.

Example 25

In Example 3, the polarizing plate was obtained like Example 3 except not having used a crosslinking agent for the adhesive agent. The thickness of an adhesive bond layer is as showing in Table 1.

Examples 26-28

In Example 3, the polarizing plate was obtained like Example 3 except having not used the crosslinking agent for the adhesive agent, and using the aqueous solution shown in Table 1 instead of pure water. The thickness of an adhesive bond layer is as showing in Table 1.

Example 29

In Example 3, pure water was dropped on the film 1 m in front of the attachment position instead of dropping pure water immediately before attaching the triacetylcellulose film with the adhesive layer and the polarizer (where the time until the attachment is 0.5 seconds). A polarizing plate was obtained in the same manner as in Example 3, except that the dropwise addition and the time until the adhesion rate of the film at 0.25 m / s were adjusted to 4 seconds. The thickness of an adhesive bond layer is as showing in Table 1.

Example 30

In Example 3, pure water was dripped on the film 1m in front of an attachment position instead of dripping pure water just before attaching the triacetylcellulose film with an adhesive bond layer, and a polarizer (the time until the time of attachment becomes 0.5 second). A polarizing plate was obtained in the same manner as in Example 3, except that the conveyance speed of the film and 0.1 m / s was adjusted to 10 seconds. The thickness of an adhesive bond layer is as showing in Table 1.

Example 31

In Example 3, pure water was dripped on the film 1m in front of an attachment position instead of dripping pure water just before attaching the triacetylcellulose film with an adhesive bond layer, and a polarizer (the time until the time of attachment becomes 0.5 second). A polarizing plate was obtained in the same manner as in Example 3 except that the conveyance speed of the film and 0.04 m / s was adjusted to 25 seconds. The thickness of an adhesive bond layer is as showing in Table 1.

Example 32

In Example 3, the polarizing plate was obtained like Example 3 except having used the polarizer B instead of the polarizer A. The thickness of an adhesive bond layer is as showing in Table 1.

Comparative Example 1

A polarizing plate was produced in the same manner as in Example 1 except that (Preparation a) of Polarizing Plate was changed to (Preparation b) of Polarizing Plate described below.

 (Manufacture of Polarizing Plate b)

As shown in FIG. 4, after sticking with a roll, supplying the said adhesive agent on both surfaces of the polarizer A, it dried at 55 degreeC for 6 minutes, and produced the polarizing plate. The conveyance speed of the film was 0.35 m / s, and the supply amount of the adhesive agent was 0.60 ml / s. A supply place was performed so that it might become a transparent protective film shape (position to time to adhere for 0.5 second), and the adhesive bond layer whose thickness after drying is 16 nm was formed.

Comparative Examples 2 to 20

In Comparative Example 1, a polarizing plate was obtained in the same manner as in Comparative Example 1 except that the kind of polyvinyl alcohol-based resin used for the adhesive, the kind of the crosslinking agent, and the concentration of the adhesive as shown in Table 1 were used. The thickness of an adhesive bond layer is as showing in Table 1. In Comparative Examples 17 to 20, polyvinyl alcohol-based resin (average degree of polymerization: 1200, saponification degree: 98.5 mol%) was used.

Comparative Example 21

In Comparative Example 3, a polarizing plate was obtained in the same manner as in Comparative Example 3 except that Polarizer B was used instead of Polarizer A. The thickness of an adhesive bond layer is as showing in Table 1.

(evaluation)

The polarizing plates obtained by the Example and the comparative example were cut out so that it might become 25 mm in the direction orthogonal to 50 mm and an absorption axis of a polarizer, and it was set as the polarizing plate sample. The following evaluation was performed about this sample. The results are shown in Table 1.

(Appearance defect evaluation)

Fluorescent lamp irradiation light was reflected on the obtained polarizing plate sample, and visual evaluation was performed on the following references | standards.

(Circle): No stripe shape, a point shape defect, and nonuniformity.

(Triangle | delta): A part has stripe shape, a point shape defect, and a nonuniformity.

X: Stripe shape, dot shape defect, and nonuniformity exist in the whole surface.

(Light leakage evaluation)

Two obtained polarizing plate samples were transmitted through fluorescent lamp irradiation light in the state which was crosslinked so that the absorption axis orthogonally crossed, and light leakage was visually evaluated on the following references | standards.

○: no light leakage

×: light leakage

(durability)

After immersing the obtained polarizing plate sample in 60 degreeC warm water for 3 hours, the peeling amount (mm) of the sample edge part was measured, and the following references | standards evaluated. The peeling amount (mm) was measured using the vernier caliper and the metal.

(Double-circle): No peeling.

○: less than 3 mm of peeling.

(Triangle | delta): Peeling 3-30 mm.

X: 31 mm or more.

In Table 1, PVA: polyvinyl alcohol, AA modified PVA: polyvinyl alcohol-type resin containing an acetoacetyl group.

Industrial availability

 The polarizing plate obtained by the manufacturing method of this invention is used independently or as an optical film which laminated | stacked this, It is used suitably for image display apparatuses, such as a flat panel display, such as a liquid crystal display device and an electroluminescent display device, and a PDP.

Brief description of the drawings

1 is an example of a schematic diagram of a method of manufacturing a polarizing plate of the present invention.

2 is an example of a schematic diagram of a method of manufacturing a polarizing plate of the present invention.

3 is an example of a schematic diagram of a conventional method for producing a polarizing plate.

4 is an example of a schematic diagram of a manufacturing method of a conventional polarizing plate.

Explanation of the sign

1: polarizer

2: transparent protective film

3: adhesive layer

3 ': adhesive

4: aqueous solution

R: Roller

Claims (20)

As a manufacturing method of the polarizing plate in which the transparent protective film was formed in at least one surface of the polarizer through the adhesive bond layer, After applying an adhesive to at least one of the surface forming the adhesive layer of the transparent protective film and the surface forming the adhesive layer of the polarizer to form the adhesive layer, the transparent protective film and the through the adhesive layer When attaching the polarizer continuously, Presence of an aqueous liquid (without adhesive) on the adhesion side, The thickness of the said adhesive bond layer is 30-300 nm, The manufacturing method of the polarizing plate characterized by the above-mentioned. The method of claim 1, The polarizer is a polyvinyl alcohol polarizer, The transparent protective film is a manufacturing method of a polarizing plate, characterized in that the cellulosic transparent protective film. The method according to claim 1 or 2, The thickness of the said polarizer is 35 micrometers or less, The manufacturing method of the polarizing plate characterized by the above-mentioned. The method according to claim 1 or 2, The adhesive is a manufacturing method of a polarizing plate, characterized in that the polyvinyl alcohol-based adhesive. The method of claim 4, wherein The polyvinyl alcohol-based adhesive is a polyvinyl alcohol-based adhesive having an acetoacetyl group. The method according to claim 1 or 2, Said adhesive contains a crosslinking agent, The manufacturing method of the polarizing plate characterized by the above-mentioned. The method of claim 6, Said crosslinking agent is a methylol compound, The manufacturing method of the polarizing plate characterized by the above-mentioned. delete The method according to claim 1 or 2, The viscosity of the said aqueous liquid is 0.1-10 cP, The manufacturing method of the polarizing plate characterized by the above-mentioned. The method of claim 6, The aqueous solution is a method for producing a polarizing plate, characterized in that water. The method according to claim 1 or 2, Said aqueous solution is an aqueous solution which melt | dissolves a crosslinking agent, The manufacturing method of the polarizing plate characterized by the above-mentioned. The method of claim 11, Said crosslinking agent is a methylol compound, The manufacturing method of the polarizing plate characterized by the above-mentioned. The method according to claim 1 or 2, The aqueous solution is supplied to the attachment surface of the said transparent protective film and said polarizer, The manufacturing method of the polarizing plate characterized by the above-mentioned. The method according to claim 1 or 2, The adhesive is apply | coated only to the said transparent protective film side, and the said aqueous liquid exists on an adhesion surface by supplying the said aqueous liquid on the adhesive bond layer formed by this application, The manufacturing method of the polarizing plate characterized by the above-mentioned. The method according to claim 1 or 2, The adhesive is apply | coated only to the said transparent protective film side, On the other hand, the said aqueous liquid exists in an adhesion surface by supplying the said aqueous liquid to the said polarizer side, The manufacturing method of the polarizing plate characterized by the above-mentioned. The method according to claim 1 or 2, An adhesive is applied only to the polarizer side, and the aqueous solution is supplied to the transparent protective film side so that the aqueous solution is present on the surface of the polarizer. The method according to claim 1 or 2, When attaching the said transparent protective film and said polarizer continuously through the said adhesive bond layer, the said aqueous liquid is supplied to an adhesion surface just before attachment, The manufacturing method of the polarizing plate characterized by the above-mentioned. The polarizing plate obtained by the manufacturing method of the polarizing plate of Claim 1. One or more polarizing plates of Claim 18 were laminated | stacked, The optical film characterized by the above-mentioned. The polarizing plate of Claim 18 or the optical film of Claim 19 is used, The image display apparatus characterized by the above-mentioned.

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