KR101243507B1 - Polarizing plate and image display device - Google Patents

Abstract

This invention is a polarizing plate which used the polyester film as a polarizer protective film, and relates to the polarizing plate which peeling at the interface of a polarizer and the said protective film is hard to produce. The polarizing plate of this invention is a polarizing plate in which at least one polyester film E and polarizer P were laminated | stacked in which the easily bonding layer H was formed in at least one main surface, and an adhesive agent is made so that the easily bonding layer formation surface of the said polyester film may face a polarizer. It is laminated via the layer G. The polarizer P and the polyester film E are resin solutions containing a polyvinyl alcohol-based resin, a crosslinking agent and a metal compound colloid having an average particle diameter of 1 to 100 nm, and the metal compound colloid is 100 parts by weight of a polyvinyl alcohol-based resin. It is preferable to laminate | stack via the adhesive bond layer mix | blended in the ratio of 200 weight part or less with respect to the said.

Description

POLARIZING PLATE AND IMAGE DISPLAY DEVICE}

The present invention relates to a polarizing plate in which a polarizer and at least one film are laminated. Moreover, this invention relates to the image display apparatus using the said polarizing plate. Moreover, this invention relates to the manufacturing method of the said image display apparatus.

In a liquid crystal display device, it is necessary to arrange | position a polarizing plate on both sides of the glass substrate which forms the liquid crystal panel surface from the image formation system. As a polarizing plate, what bonded the polarizer protective film which used triacetyl cellulose etc. with the polyvinyl alcohol-type adhesive agent on both surfaces of the polarizer which consists of a polyvinyl alcohol-type film and dichroic materials, such as iodine, is generally used.

However, triacetyl cellulose does not have sufficient heat and moisture resistance, and when the polarizing plate using a triacetyl cellulose film as a polarizer protective film is used under high temperature or high humidity, there exists a fault that the performance of polarizing plates, such as polarization degree and a hue, falls.

In order to solve the said problem, cyclic olefin resin is proposed instead of triacetyl cellulose as a material of a polarizer protective film. Since cyclic olefin resin is low in moisture permeability, it is possible to highly durable a polarizing plate. However, the polyvinyl alcohol adhesive is excellent in the adhesion of the triacetyl cellulose film and the polyvinyl alcohol polarizer, but is insufficient in the adhesion of the cyclic olefin resin film and the polyvinyl alcohol polarizer.

Therefore, as a method of adhering a cyclic olefin resin film and a polyvinyl alcohol-type polarizer, the method of adhering via an acrylic adhesive layer is proposed (refer patent document 1). However, this method requires heat compression, and the heating time is long, so that there is a problem that the polyvinyl alcohol polarizer is discolored, and the polarization degree of the polarizing plate is remarkably lowered. Moreover, since long time heating is required, there is also a problem that the production efficiency is low and the film is deformed.

Moreover, the polyester film is proposed as a polarizer protective film (refer patent document 2, 3). Moreover, in order to solve the problem of adhesiveness and film strength, the method of coextrusion molding polyester, a styrene-type or an olefinic monomer, nylon resin, or acrylic resin is disclosed (refer patent document 4-7). .

Japanese Patent Laid-Open No. 5-212828 Japanese Patent Laid-Open No. 8-271733 Japanese Patent Laid-Open No. 8-271734 Japanese Patent Laid-Open No. 2006-215466 Japanese Patent Laid-Open No. 2006-220731 Japanese Patent Laid-Open No. 2006-220732 Japanese Patent Laid-Open No. 2006-276574

However, polyester does not have sufficient adhesiveness with a polarizer and another resin layer, and even if it is by co-extrusion disclosed by patent documents 4-7 etc., peeling occurs easily at the interface of a polyester layer and another resin layer. Had problems such as;

This invention provides the polarizing plate which has a polyester layer which is excellent in adhesiveness and hard to produce film peeling in view of the said viewpoint.

MEANS TO SOLVE THE PROBLEM As a result of earnestly examining, the present inventors discovered that the said subject can be solved by a specific structure, and came to this invention. That is, in this invention, the at least 1 polyester film E and the polarizer P in which the easily bonding layer H was formed in at least one main surface are interposed through the adhesive bond layer G so that the easily bonding layer formation surface of the said polyester film may face the said polarizer. The polarizing plate laminated | stacked by this is related.

Moreover, in the polarizing plate of this invention, the said adhesive bond layer G is a resin solution which contains a polyvinyl alcohol-type resin, a crosslinking agent, and the metal compound colloid whose average particle diameter is 1-100 nm, and a metal compound colloid is polyvinyl alcohol It is preferable to form with the adhesive mix | blended in the ratio of 200 weight part or less with respect to 100 weight part of system resin.

Moreover, in the polarizing plate of this invention, it is preferable that the said easily bonding layer H contains a polyvinyl alcohol-type compound or a polyurethane compound.

As one Embodiment of the said polarizing plate, the polyester film E in which the easily bonding layer H was formed in the at least one main surface on one main surface of the said polarizer P is laminated | stacked via the adhesive bond layer G, and the other main surface of the said polarizer P is The polarizing plate in which the film is not laminated is mentioned.

Moreover, this invention relates to the image display apparatus which has the said polarizing plate.

Moreover, this invention relates to the manufacturing method of the said image display apparatus. As one embodiment of the manufacturing method of the image display apparatus of this invention, the roll raw material preparation process of preparing the long sheet of the said polarizing plate as a roll raw material, and unwinding a sheet product from the said roll raw material, and cut | disconnecting the said polarizing plate using a cutting means It is preferable to have the cutting process of cutting | disconnecting to a predetermined magnitude | size, and the bonding process of bonding the said polarizing plate to an optical display unit via an adhesive layer after the said cutting process.

1 is a schematic cross-sectional view of a polarizing plate according to a preferred embodiment of the present invention.
2 is a flowchart showing an example of a conventional method for manufacturing an optical display unit.
3 is a flowchart showing an example of a method of manufacturing the image display device of the present invention.
4 is a flowchart showing an example of a method of manufacturing the image display device of the present invention.
5A is a diagram for explaining an example of a configuration of a manufacturing system of an image display device.
5B is a diagram for explaining an example of a configuration of a manufacturing system of an image display device.

This invention relates to the polarizing plate in which the at least 1 polyester film E and the polarizer P in which the easily bonding layer H was formed in at least one main surface were laminated | stacked through the adhesive bond layer G. Hereinafter, the preferable aspect about the said polyester film E, the easily bonding layer H, the polarizer P, and the adhesive bond layer G is demonstrated sequentially.

[Polyester Film]

Polyester film E is used as a polarizer protective film. The material for forming the polyester film is not particularly limited, but for example, terephthalic acid, isophthalic acid, orthophthalic acid, 2,5-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, 1,4-naphthalene Dicarboxylic acid, 1,5-naphthalenedicarboxylic acid, diphenylcarboxylic acid, diphenoxyethanedicarboxylic acid, diphenylsulfoncarboxylic acid, anthracenedicarboxylic acid, 1,3-cyclopentanedica Carboxylic acid, 1,3-cyclohexanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, hexahydroterephthalic acid, hexahydroisophthalic acid, malonic acid, dimethylmalonic acid, succinic acid, 3,3-diethyl Succinic acid, glutaric acid, 2,2-dimethylglutaric acid, adipic acid, 2-methyladipic acid, trimethyladipic acid, pimelic acid, azelaic acid, dimer acid, sebacic acid, suberic acid, dodecadicar Dicarboxylic acids such as acid, ethylene glycol, propylene glycol, hexamethylene glycol, neopentyl glycol, 1,2 -Cyclohexanedimethanol, 1,4-cyclohexanedimethanol, decamethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexadiol, 2,2- Homopolymers obtained by polycondensing diols such as bis (4-hydroxyphenyl) propane and bis (4-hydroxyphenyl) sulfone, or polycondensing one or more dicarboxylic acids and two or more diols The polyester resin which consists of a copolymer which consists of polycondensation of the copolymer which consists of two or more types of dicarboxylic acids, or 1 or more types of diol, and 2 or more types of these homopolymers and copolymers can be mentioned. have. Especially, polyethylene terephthalate resin is used preferably.

A polyester film is obtained by the method of melt-extruding the said polyester resin in film form, for example, cooling-solidifying by a casting drum, and forming a film. As polyester film E in the polarizing plate of this invention, both a non-stretched film and a stretched film can be used. For example, when it is desired that the birefringence is small, a non-stretched film can be suitably used. Moreover, when using birefringence for optical compensation of a liquid crystal display device, a stretched film can be used suitably. In addition, a stretched film, especially a biaxially stretched film, is suitably used also in terms of strength.

When polyester film E is a stretched film, the extending | stretching method is not specifically limited, The longitudinal uniaxial stretching method, the lateral uniaxial stretching method, the longitudinal and horizontal sequential biaxial stretching method, the vertical and horizontal simultaneous biaxial stretching method, etc. can be employ | adopted. As a stretching means, it can be based on arbitrary appropriate stretching machines, such as a roll stretching machine, a tenter stretching machine, a biaxial stretching machine of a pantograph type, or a linear motor type.

5-500 micrometers is preferable, as for the thickness of the said polyester film E, 5-200 micrometers is more preferable, and its 10-150 micrometers are more preferable. When thickness is smaller than the said range, a film will break easily, a problem arises in the intensity | strength at the time of applying to a polarizing plate, insufficient water barrier property, and durability of a polarizer may be inferior. When thickness is larger than the said range, the flexibility of a film runs short and handling property may fall, or manufacture of the polyester film itself may become difficult.

[Easy Adhesive Layer]

In the polarizing plate of this invention, the easily bonding layer H is formed in the said polyester film E in at least one main surface. Examples of such easy bonding layer H include those formed by hydrophilic cellulose derivatives, polyvinyl alcohol compounds, hydrophilic polyester compounds, polyvinyl compounds, (meth) acrylic acid compounds, epoxy resins, polyurethane compounds, natural polymer compounds, and the like. have.

As a hydrophilic cellulose derivative, methyl cellulose, carboxymethyl cellulose, hydroxy cellulose, etc. are mentioned.

Examples of the polyvinyl alcohol-based compound include polyvinyl alcohol, vinyl acetate-vinyl alcohol copolymers, polyvinyl acetate, polyvinyl acetal, polyvinyl formal, polyvinyl benzal, and the like. It is preferable to mix | blend a crosslinking agent especially from an adhesive viewpoint with a polyester film. Preferable crosslinking agents are mentioned later.

As a hydrophilic polyester type compound, sulfonated polyethylene terephthalate etc. are mentioned.

Examples of the polyvinyl compound include poly-N-vinylpyrrolidone, polyacrylamide, polyvinylimidazole, polyvinylpyrazole and the like.

As the (meth) acrylic acid compound, acrylic acid, carboxyalkyl acrylate, alkyl ester acrylate, hydroxyalkyl acrylate, hydroxyalkyl acrylate, methacrylic acid, carboxyalkyl methacrylate, alkyl ester methacrylate, hydroxy Alkyl methacrylate, hydroxyalkyl methacrylate, etc. are mentioned.

As an epoxy resin, Aromatic epoxy resins, such as a bisphenol-type epoxy resin, a novolak-type epoxy resin, and epoxidized polyvinyl phenol, Hydrogenated substance of an aromatic epoxy resin, Cyclohexane-type epoxy resin, Cyclohexyl methyl ether type | system | group, Epoxy resin, etc. Aliphatic epoxy resins, such as a formula epoxy resin, polyalkylene oxide glycidyl ether, polyether polyol glycidyl ether, and polyether polyol glycidyl ether, are mentioned.

As a polyurethane compound, the reactant with polyols, such as an acryl polyol, polyester polyol, and a polyether polyol, and polyisocyanate, such as tetramethylene diisocyanate and isophorone diisocyanate, etc. are mentioned. Among them, polyester-based polyurethanes are suitably used from the viewpoint of adhesiveness with the polyester film.

As a natural high molecular compound, gelatin, casein, arabic rubber, etc. are mentioned.

Among the above-mentioned, a polyvinyl alcohol derivative or a polyurethane compound can be used suitably from an adhesive viewpoint.

In addition, the said easily bonding layer H may contain a crosslinking agent. In particular, when the easily bonding layer is generally low in adhesiveness (adhesiveness) to a polyester film, such as a polyvinyl alcohol compound or a polyvinyl compound, it is preferable that the easily bonding layer H contains a crosslinking agent. . As such a crosslinking agent, crosslinking agents, such as an acryl type, a styrene type, an epoxy type, a phenol type, a phenoxy ether type, a phenoxy ester type, a melamine type, a urethane type, are mentioned, for example. Especially, the crosslinking agent which has an oxazoline group, a diimide group, a hydrazine group, and an epoxy group can be used suitably from a viewpoint of improving the adhesiveness of a polyester and an easily bonding layer.

It is preferable to form the easily bonding layer H by apply | coating said compound on a polyester film as a solution, a dispersion liquid, or an emulsion liquid. It is preferable to use it as an aqueous coating liquid from a viewpoint of preventing environmental pollution at the time of application | coating and obtaining explosion proof property. Moreover, surfactant can also be mix | blended from a viewpoint of promoting the wetness of the aqueous coating liquid to a polyester film, and a viewpoint of improving the stability of a coating liquid. Although the suitable compounding quantity of surfactant to a coating liquid changes with kinds of surfactant, it can manufacture suitably so that it may have sufficient adhesiveness with a polarizer. For example, what is necessary is just to contain about 1-10 parts per 100 weight part of solid content of aqueous coating liquid.

The surfactant may be any of anionic, cationic and nonionic types, and examples thereof include polyoxyethylene-fatty acid esters, sorbitan fatty acid esters, glycerin fatty acid esters, fatty acid metal soaps, alkyl sulfates and alkyl sulfonic acids. Salts, alkylsulfosuccinic acid salts, quaternary ammonium chloride salts, alkylamine hydrochloric acid, betaine type surfactants, and the like.

You may add an antistatic agent, a coloring agent, a ultraviolet absorber, a crosslinking agent, a pigment, an organic filler, and an inorganic filler to a coating liquid further.

Solid content concentration of a coating liquid is 20 weight% or less normally, Preferably it is 1-10 weight%. When the solid content concentration is excessively small, the applicability to the polyester film may be insufficient, and when the solid content concentration is excessively large, the stability of the coating liquid and the uniformity and appearance of the coating layer may be deteriorated.

Application of the aqueous coating liquid to the polyester film can be performed at any stage. When a polyester film is a non-stretched film, it can apply | coat at arbitrary steps after film formation. Moreover, when a polyester film is a stretched film, it can apply | coat in any stage before extending | stretching after film formation, extending | stretching, or extending | stretching. Application | coating in extending | stretching is the case of apply | coating before transverse stretching, for example, after extending | stretching a film longitudinally in longitudinal and sequential biaxial stretching. In particular, stretching by a tenter stretching machine, a pantograph type, or a linear motor type biaxial stretching machine does not need to contact the film and the roll during the stretching process, and thus the stretching and drying of the coating liquid by applying the coating liquid immediately before stretching. Since it can be implemented in one process, it is a preferable structure.

When apply | coating a coating liquid to a polyester film, a corona treatment, a plasma treatment, etc. can also be previously given to the film surface from a viewpoint of improving applicability | paintability.

It is preferable to adjust the application amount of a coating liquid so that the thickness of an easily bonding layer may be about 0.001-10 micrometers, Furthermore, it is about 0.001-5 micrometers, Especially about 0.001-1 micrometer. If the thickness of the coating layer is excessively small, the adhesive force with the polarizer may be insufficient. If the thickness is excessively large, blocking may occur or the haze may increase.

As a coating method, the well-known arbitrary coating methods can be applied. For example, a roll coating method, a gravure coating method, a roll brush method, a spray coating method, an air knife coating method, an impregnation method, a curtain coating method can be provided. These may be used alone or in combination. The coating liquid apply | coated on the polyester film is formed on a film as an easily bonding layer by drying by heating etc.

[Polarizer]

A polarizer means the film which can be converted into natural polarization from natural light or polarization. Arbitrary suitable polarizers can be employ | adopted as a polarizer used for this invention, but what converts natural light or polarization into linearly polarized light is used preferably.

In the polarizing plate of this invention, arbitrary suitable things can be employ | adopted as the polarizer P according to the objective. For example, uniaxial stretching by adsorbing dichroic substances such as iodine or dichroic dye to hydrophilic polymer films such as polyvinyl alcohol films, partially formalized polyvinyl alcohol films, and ethylene / vinyl acetate copolymerized partial saponified films And polyene-based alignment films such as dehydrated products of polyvinyl alcohol and dehydrochloric acid treated products of polyvinyl chloride. In addition, a guest-host type O polarizer in which a liquid crystal composition comprising a dichroic substance and a liquid crystal compound disclosed in U.S. Patent No. 5,523,863 and the like is oriented in a predetermined direction, and lyotropic disclosed in U.S. Patent No. 6,049,428 and the like. E-type polarizer etc. which orientated the liquid crystal in the fixed direction can also be used.

Among these polarizers, the polarizer by the polyvinyl alcohol-type film containing iodine is used suitably from a viewpoint of having a high degree of polarization, and the adhesiveness with the polyester film in which the said easily bonding layer was formed. As the material of the polyvinyl alcohol-based film applied to the polarizer, polyvinyl alcohol or a derivative thereof is used. Examples of the polyvinyl alcohol derivatives include polyvinyl formal and polyvinyl acetal, and unsaturated carboxylic acids such as olefins such as ethylene and propylene, acrylic acid, methacrylic acid and crotonic acid, alkyl esters thereof, The thing modified with acrylamide etc. is mentioned. The polyvinyl alcohol has a degree of polymerization of about 1000 to 10000 and a degree of saponification of about 80 to 100 mol%.

The polyvinyl alcohol-based film may contain an additive such as a plasticizer. Examples of the plasticizer include polyols and condensates thereof, and examples thereof include glycerin, diglycerine, triglycerine, ethylene glycol, propylene glycol, polyethylene glycol, and the like. Although the usage-amount of a plasticizer is not specifically limited, It is suitable to set it as 20 weight% or less in a polyvinyl alcohol-type film.

The polyvinyl alcohol-based film (unstretched film) is at least uniaxially stretched and iodine dyed in accordance with a conventional method. Furthermore, boric acid treatment and iodine ion treatment can be performed. Moreover, the polyvinyl alcohol-type film (stretched film) to which the said process was performed is dried in accordance with a conventional method, and becomes a polarizer.

The stretching method in the uniaxial stretching treatment is not particularly limited, and either the wet stretching method or the dry stretching method can be adopted. Examples of the stretching means of the dry stretching method include an inter-roll stretching method, a heating roll stretching method, a compression stretching method, and the like. Stretching may be performed in multiple stages. In the stretching means, the unstretched film is usually in a heated state. Usually, about 30-150 micrometers of unstretched films are used. Although the draw ratio of a stretched film can be set suitably according to the objective, It is preferable to set draw ratio (total draw ratio) about 2 to 8 times, Preferably it is 3 to 6.5 times, More preferably, it is 3.5 to 6 times. As for the thickness of a stretched film, about 5-40 micrometers is suitable.

An iodine dyeing process is performed by immersing a polyvinyl alcohol-type film in the iodine solution containing iodine and potassium iodide. The iodine solution is usually an aqueous solution of iodine and contains potassium iodide as iodine and dissolution aid. The iodine concentration is preferably about 0.01 to 1% by weight, preferably 0.02 to 0.5% by weight, and the potassium iodide concentration is preferably used at about 0.01 to 10% by weight, more preferably 0.02 to 8% by weight.

In the iodine dyeing treatment, the temperature of the iodine solution is usually about 20 to 50 ° C, preferably 25 to 40 ° C. Immersion time is about 10 to 300 second normally, Preferably it is the range of 20 to 240 second. In the iodine dyeing process, the iodine content and the potassium content in the polyvinyl alcohol-based film are adjusted to the above ranges by adjusting conditions such as the concentration of the iodine solution, the immersion temperature of the polyvinyl alcohol-based film in the iodine solution, the immersion time, and the like. do. The iodine dyeing treatment may be performed at any stage after the uniaxial stretching treatment, during the uniaxial stretching treatment, before the uniaxial stretching treatment.

Boric acid treatment is performed by immersing a polyvinyl alcohol-type film in boric-acid aqueous solution. The boric acid concentration in boric acid aqueous solution is about 2 to 15 weight%, Preferably it is 3 to 10 weight%. In boric acid aqueous solution, potassium iodide can be contained by potassium iodide. The potassium iodide concentration in the boric acid aqueous solution is preferably about 0.5 to 10% by weight, more preferably 1 to 8% by weight. The boric acid aqueous solution containing potassium iodide can obtain a polarizer of little coloration, that is, a so-called neutral gray polarizer whose absorbance is almost constant over an almost full-wavelength region of visible light.

For the iodine ion treatment, an aqueous solution containing iodine ions with potassium iodide or the like is used, for example. The potassium iodide concentration is preferably about 0.5 to 10% by weight, more preferably 1 to 8% by weight. At the time of an iodine ion impregnation process, the temperature of this aqueous solution is about 15-60 degreeC normally, Preferably it is 25-40 degreeC. Immersion time is about 1 to 120 second normally, Preferably it is the range of 3 to 90 second. The step of the iodine ion treatment is not particularly limited as long as it is before the drying step. You may carry out after water washing mentioned later.

The polarizer may also contain zinc. It is preferable to contain zinc in a polarizer from the point of suppression of color deterioration in a heating environment. It is preferable to adjust content of the zinc in a polarizer to the extent that a zinc element contains 0.002 to 2 weight% in a polarizer. Furthermore, it is preferable to adjust to 0.01 to 1 weight%. Zinc content in a polarizer is preferable in the said range in which durability improvement effect is good and suppresses deterioration of a hue.

Zinc salt solution is used for a zinc impregnation process. As the zinc salt, inorganic salt compounds of aqueous solutions, such as zinc halides such as zinc chloride and zinc iodide, zinc sulfate and zinc acetate, are suitable. Among these, zinc sulfate is preferable because the retention rate in the polarizer of zinc can be improved. In addition, various zinc complex compounds can be used for the zinc impregnation treatment. The concentration of zinc ions in the zinc salt aqueous solution is about 0.1 to 10% by weight, preferably 0.3 to 7% by weight. As the zinc salt solution, it is preferable to use an aqueous solution containing potassium ions and iodine ions with potassium iodide or the like to easily impregnate the zinc ions. The potassium iodide concentration in the zinc salt solution is preferably about 0.5 to 10% by weight, more preferably 1 to 8% by weight.

At the time of zinc impregnation process, the temperature of a zinc salt solution is about 15-85 degreeC normally, Preferably it is 25-70 degreeC. Immersion time is about 1 to 120 second normally, Preferably it is the range of 3 to 90 second. In the zinc impregnation treatment, the zinc content in the polyvinyl alcohol-based film can be adjusted by adjusting the concentration of the zinc salt solution, the immersion temperature in the zinc salt solution of the polyvinyl alcohol-based film, the immersion time and the like. The step of the zinc impregnation treatment is not particularly limited, and may be before the iodine dyeing treatment or after the boric acid treatment during the boric acid treatment before the immersion treatment in the boric acid aqueous solution after the iodine dyeing treatment. Moreover, zinc salt may coexist in an iodine dyeing solution, and you may carry out simultaneously with an iodine dyeing process. It is preferable to perform a zinc impregnation process with a boric acid process. It may also be possible to perform a uniaxial stretching treatment together with the zinc impregnation treatment. In addition, you may perform a zinc impregnation process multiple times.

The polyvinyl alcohol-type film (stretched film) to which the said process was performed can be used for a water washing process and a drying process according to a conventional method.

The water washing step is usually performed by immersing the polyvinyl alcohol-based film in pure water. Water washing temperature is 5-50 degreeC normally, Preferably it is 10-45 degreeC, More preferably, it is the range of 15-40 degreeC. Immersion time is 10 to 300 second normally, Preferably it is about 20 to 240 second.

As a drying process, arbitrary suitable drying methods, for example, natural drying, ventilation drying, heat drying, etc. can be employ | adopted. For example, in the case of heat drying, the drying temperature is typically 20 to 80 ° C, preferably 25 to 70 ° C, and the drying time is preferably about 1 to 10 minutes. In addition, the moisture content of the polarizer after drying is preferably 10 to 30% by weight, more preferably 12 to 28% by weight, and even more preferably 16 to 25% by weight. When the moisture content is excessively large, the polarization degree tends to decrease with drying of the polarizer when drying the laminated body in which the polarizer and the optical element or the isotropic film are bonded through the adhesive layer, that is, the polarizing plate, as described later. In particular, since the orthogonal transmittance in the short wavelength region of 500 nm or less is increased, that is, light of short wavelength is leaked, the black display tends to be colored blue. On the contrary, when the moisture content of a polarizer is too small, problems, such as a local uneven | corrugated defect (knick defect) are easy to produce, may arise.

Arbitrary appropriate thickness can be employ | adopted as thickness of the polarizer P used for the polarizing plate of this invention. The thickness of a polarizer is typically 5-80 micrometers, Preferably it is 10-50 micrometers, More preferably, it is 20-40 micrometers. If it is the said range, it is excellent in an optical characteristic or mechanical strength.

Adhesive Layer

The polyester film E and the polarizer P in which the easily bonding layer H was formed in the said at least one main surface are laminated | stacked through the adhesive bond layer G so that the easily bonding layer formation surface of a polyester film and a polarizer may oppose. At this time, it is preferable to laminate both without an air gap by the adhesive layer. The adhesive layer G is formed by an adhesive. The kind of adhesive is not specifically limited, Various things can be used.

In particular, in the present invention, a resin solution comprising a polyvinyl alcohol-based resin, a crosslinking agent and a metal compound colloid having an average particle diameter of 1 to 100 nm is used as an adhesive in the adhesive layer G for laminating the polarizer P and the polyester film E. It is desirable to. Although it is common to dry a polarizer and a polarizer protective film after adhering through an adhesive bond layer, there exists a tendency for the unevenness | corrugation (nick) to occur easily at this time. When using a polyester film as a polarizer protective film especially for the polarizer by a polyvinyl alcohol-type film, when using cellulose resin films, such as triacetyl cellulose generally used as a polarizer protective film, as a polarizer protective film In comparison with this, the occurrence of nicks tends to be remarkable. Therefore, in lamination | stacking of polyester film E and polarizer P in the polarizing plate of this invention, it is preferable to use the adhesive agent of the said composition.

As polyvinyl alcohol-type resin used for an adhesive agent, 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 is preferable because durability of a polarizing plate improves.

Polyvinyl alcohol-type resin is polyvinyl alcohol obtained by saponifying polyvinyl acetate; Derivatives thereof; Moreover, saponified copolymer of vinyl acetate and the copolymer which has a copolymerizability; The modified polyvinyl alcohol which performed acetalization, urethanation, etherification, grafting, phosphate esterification, etc. of polyvinyl alcohol is mentioned. As said monomer, Unsaturated carboxylic acid, such as maleic acid (anhydride), fumaric acid, crotonic acid, itaconic acid, (meth) acrylic acid, and its ester; Α-olefins such as ethylene and propylene, (meth) allyl sulfonic acid (soda), sulfonic acid soda (monoalkyl maleate), disulfonic acid soda alkyl maleate, N-methylol acrylamide, acrylamidoalkyl sulfonic acid alkali salt, N -Vinylpyrrolidone, N-vinylpyrrolidone derivative, etc. are mentioned. 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, the average degree of polymerization is about 100-5000, Preferably it is 1000-4000, The average saponification degree is about 85-100 mol%, Preferably it is 90-100 mol%.

Polyvinyl alcohol-type resin containing an acetoacetyl group is obtained by making polyvinyl alcohol-type resin and diketene react by a well-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 to etc. are mentioned. Moreover, the method of directly contacting diketene gas or liquid diketene with polyvinyl alcohol is mentioned.

The acetoacetyl group modification degree of the polyvinyl alcohol-based resin containing an acetoacetyl group is not particularly limited as long as it is 0.1 mol% or more. If it is less than 0.1 mol%, the water resistance of the adhesive layer tends to be insufficient. 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 acetoacetyl group denaturation exceeds 40 mol%, the improvement effect of water resistance may not be fully acquired. Acetoacetyl group denaturation can be quantified by NMR.

As a crosslinking agent used for an adhesive agent, what is used for the polyvinyl alcohol-type adhesive agent can be used without a restriction | limiting in particular. The compound which has at least 2 functional group which has 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, trimethylolpropane tolylene diisocyanate adduct, triphenylmethane triisocyanate, methylene bis (4-phenylmethanetriisocyanate), isophorone diisocyanate and ketooxime blockers thereof or Isocyanates such as phenol block water; Ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, glycerin diglycidyl ether, glycerin triglycidyl ether, 1,6-hexanediol diglycidyl ether, trimethylolpropane triglycidyl ether, di Epoxy, such as glycidyl aniline and diglycidylamine; Monoaldehydes such as formaldehyde, acetaldehyde, propionaldehyde and butylaldehyde; Dialdehydes such as glyoxal, malondialdehyde, succinic aldehyde, glutaldialdehyde, maleindialdehyde and phthaldialdehyde; Amino-formaldehyde resins such as methylolurea, methylolmelamine, alkylated methylolurea, alkylated methylolated melamine, acetoguanamine, and condensates of benzoguanamine and formaldehyde; In addition, salts of divalent metals such as sodium, potassium, magnesium, calcium, aluminum, iron, nickel, or trivalent metals and oxides thereof may be mentioned. Among these, amino-formaldehyde resins and dialdehydes are preferable. As an amino-formaldehyde resin, the compound which has a methylol group is preferable, and glyoxal is suitable as a dialdehyde. Especially, methylol melamine which is a compound which has a methylol group is suitable.

Although the compounding quantity of the said crosslinking agent can be suitably designed according to the kind etc. of polyvinyl alcohol-type resin in an adhesive agent, it is about 10-60 weight part normally with respect to 100 weight part of polyvinyl alcohol-type resins, Preferably it is 20-50 weight part It is wealth. Good adhesion is obtained in this range.

In order to improve durability, it is preferable to use polyvinyl alcohol-type resin containing an acetoacetyl group. Also in this case, it is preferable to use a crosslinking agent in 10 to 60 weight part, further 20 to 50 weight part with respect to 100 weight part of polyvinyl alcohol-type resins in an adhesive agent. When the compounding quantity of a crosslinking agent increases too much, reaction of a crosslinking agent advances in a short time and there exists a tendency for an adhesive agent to gelatinize. As a result, the pot life (pot life) as an adhesive agent becomes extremely short, and industrial use may become difficult. From this point of view, the compounding amount of the crosslinking agent is used in the above compounding amount, but since the resin solution of the present invention contains a metal compound colloid, it can be used stably even when the compounding amount of the crosslinking agent is large as described above.

The metal compound colloid used for an adhesive is a thing in which microparticles | fine-particles are disperse | distributed in the dispersion medium, and are electrostatically stabilized by the mutual repulsion of the homogeneous charge of microparticles | fine-particles, and have permanent stability. The average particle diameter of the metal compound colloid (particulates) is 1 to 100 nm. If the average particle diameter of the said colloid is the said range, a metal compound can be disperse | distributed substantially uniformly in an adhesive bond layer, adhesiveness can be ensured, and nick can be suppressed. The range of the said average particle diameter is considerably smaller than the wavelength range of visible light, and even if transmitted light scatters with the metal compound in the adhesive bond layer formed, it does not adversely affect polarization characteristic. It is preferable that the average particle diameter of a metal compound colloid is 1-100 nm, Furthermore, it is 1-50 nm.

As a metal compound colloid, various things can be used. For example, as a metal compound colloid, colloid of metal oxides, such as alumina, a silica, a zirconia, titania, aluminum silicate, a calcium carbonate, magnesium silicate; Colloids of metal salts such as zinc carbonate, barium carbonate and calcium phosphate; And colloids of minerals such as celite, talc, clay, and kaolin.

The metal compound colloid is disperse | distributed to a dispersion medium and exists in the state of the colloid solution. The dispersion medium is mainly water. In addition to water, other dispersion mediums, such as alcohol, can also be used. Although the solid content concentration of the metal compound colloid in a colloidal solution is not specifically limited, Usually, it is common that it is about 1-50 weight%, Furthermore, it is 1-30 weight%. In addition, the metal compound colloid can use what contains acids, such as nitric acid, hydrochloric acid, an acetic acid, as a stabilizer.

Metal compound colloids are electrostatically stabilized and are divided into those having an electrostatic charge and those having a negative charge. The metal compound colloid is a nonconductive material. Electrostatic charges and negative charges are distinguished by the state of charge of the colloidal surface charge in the solution after adhesive preparation. The charge of the metal compound colloid can be confirmed, for example, by measuring the zeta potential with a zeta potential meter. The surface charge of the metal compound colloid generally changes with pH. Thus, the charge of the state of the colloidal solution of the present application is influenced by the pH of the prepared adhesive solution. The pH of the adhesive solution is usually set in the range of 2 to 6, preferably 2.5 to 5, more preferably 3 to 5, and further 3.5 to 4.5. In the present invention, the metal compound colloid having an electrostatic charge has a greater effect of suppressing the occurrence of nicks than the metal compound colloid having a negative charge. Examples of the metal compound colloid having an electrostatic charge include alumina colloids, titania colloids, and the like. Among these, especially alumina colloid is suitable.

It is preferable to mix | blend a metal compound colloid in the ratio (calculated value of solid content) of 200 weight part or less with respect to 100 weight part of polyvinyl alcohol-type resins. By making the compounding ratio of a metal compound colloid into the said range, generation | occurrence | production of a nick can be suppressed, ensuring the adhesiveness of a polarizer and a protective film. It is preferable that the compounding ratio of a metal compound colloid is 10-200 weight part, Furthermore, it is preferable that it is 20-175 weight part, Furthermore, it is 30-150 weight part. If the blending ratio of the metal compound colloid to the polyvinyl alcohol-based resin is excessive, the adhesiveness may be inferior. If the blending ratio of the metal compound colloid is small, the effect of suppressing the occurrence of nick may not be sufficiently obtained.

Such an adhesive agent is normally used as aqueous solution. Although the resin solution concentration does not have a restriction | limiting in particular, It is 0.1-15 weight%, Preferably it is 0.5-10 weight% in consideration of coating property, standing stability, etc.

Although the viscosity of the resin solution as an adhesive agent is not specifically limited, The thing of the range of 1-50 mPa * s can be used suitably. In the bonding of the polarizer and the transparent protective film, it is common that the occurrence of nick increases as the viscosity of the adhesive decreases. However, by setting the adhesive to the composition as described above, regardless of the viscosity of the resin solution, 1 to 20 mPa · s The occurrence of nicks can be suppressed even in a low viscosity range such as a range. Although polyvinyl alcohol-based resins containing acetoacetyl groups have not been able to increase the degree of polymerization as compared to general polyvinyl alcohol resins, and have been used at low viscosity as described above, polyvinyl alcohol-based systems containing acetoacetyl groups may be obtained by setting the adhesive to such a composition. Even when resin is used, generation of nicks caused by low viscosity of the resin solution can be suppressed.

The manufacturing method of the resin solution as an adhesive agent is not specifically limited. Usually, a resin solution is manufactured by mix | blending a polyvinyl alcohol-type resin and a crosslinking agent, and mix | blending a metal compound colloid with what prepared the density | concentration suitably. As the polyvinyl alcohol-based resin, a polyvinyl alcohol-based resin containing an acetoacetyl group is used, or when the amount of the crosslinking agent is large is mixed, the polyvinyl alcohol-based resin and the metal compound colloid are mixed in consideration of the stability of the solution. Then, a crosslinking agent can be mixed, considering the usage time of the resin solution obtained, etc. In addition, the density | concentration of the resin solution which is an adhesive agent can also be adjusted suitably after manufacturing a resin solution.

Moreover, you may mix | blend a coupling agent, such as a silane coupling agent and a titanium coupling agent, various tackifiers, a ultraviolet absorber, antioxidant, a heat resistant stabilizer, stabilizers, such as a hydrolysis stabilizer, etc. further to an adhesive agent. In addition, the metal compound colloid herein is a non-conductive material, but may contain fine particles of a conductive material.

When laminating | stacking the polyester film E with the said polarizer P and the easily bonding layer H formed using an adhesive agent, application | coating of an adhesive may be performed anywhere in the easily bonding layer H formation surface of the polyester film E, and the polarizer P. Or both. It is preferable to perform application | coating of an adhesive agent so that thickness of the adhesive bond layer G after drying may be about 10-300 nm. It is more preferable that it is 10-200 nm, and, as for the thickness of adhesive bond layer G from a point which acquires uniform in-plane thickness and sufficient adhesive force, it is still more preferable that it is 20-150 nm. In addition, when using the resin solution which contains the above-mentioned polyvinyl alcohol-type resin, a crosslinking agent, and the metal compound colloid whose average particle diameter is 1-100 nm, the thickness of the adhesive bond layer G is the metal compound contained in an adhesive agent. It is preferable to design so that it may become larger than the average particle diameter of a colloid.

Although it does not restrict | limit especially as a method of adjusting the thickness of adhesive bond layer G, For example, the method of adjusting the solid content concentration of an adhesive agent solution, and the coating device of an adhesive agent is mentioned. Although it does not restrict | limit especially as such a measuring method of the adhesive bond layer thickness, SEM (Scanning Electron Microscopy) and cross-sectional observation measurement by Transmission Electron Microscopy (TEM) are used preferably. The application | coating operation of an adhesive agent is not specifically limited, Various means, such as a roll method, the spray method, and the immersion method, can be employ | adopted.

In addition, you may perform surface modification treatment to the easily bonding layer H formed in the polyester film E before apply | coating an adhesive agent. As a specific treatment, for example, corona treatment, plasma treatment, primer treatment, saponification treatment, or the like can be performed.

After apply | coating an adhesive agent, the polarizer P and the polyester film E are bonded by a roll laminator etc. As described above, the water content of the polarizer used in this bonding step is preferably 10 to 30% by weight, more preferably 12 to 28% by weight, still more preferably 16 to 25% by weight. . By setting the moisture content in the above range, the degree of polarization can be maintained high, and the occurrence of nicks and appearance irregularities can be prevented.

Moreover, from a viewpoint of stabilizing optical characteristics, such as polarization degree and a hue, after bonding a polyester film to both surfaces of a polarizer, it is preferable to dry at an appropriate drying temperature. It is preferable that it is 90 degrees C or less from a viewpoint of an optical characteristic, It is more preferable that it is 85 degrees C or less, It is further more preferable that it is 80 degrees C or less. Moreover, there is no minimum in drying temperature, but considering a efficiency and practicality of a process, it is preferable that it is 50 degreeC or more. In addition, a drying temperature can also be performed by heating up in steps within the said temperature range.

[Lamination Form of Polarizing Plate]

As for the polarizing plate of this invention, the polyester film E in which the said easily bonding layer H was formed is laminated | stacked on at least one main surface of the polarizer P. As such embodiment, the form as (a)-(c) of FIG. 1 is mentioned, for example. Hereinafter, these structures are explained in full detail in order.

[Stacked form a]

FIG.1 (a) is a form in which the polyester film E is laminated | stacked on both main surfaces of the polarizer P. FIG. In this aspect, it is preferable that the easily bonding layer H is formed in both polyester films E as shown to Fig.1 (a). In addition, the polyester film E laminated | stacked on one main surface of the polarizer P and the polyester film E laminated | stacked on the other main surface may be the same, and may differ.

(Retardation Value of Polyester Film)

As polyester film E, since birefringence is small and a polarization state is not changed, a thing with a front phase difference less than 40 nm and thickness direction retardation less than 80 nm can be used. Thus, as a polyester film with a small birefringence, a non-stretched film is used suitably.

Front phase difference Re is represented by Re = (nx-ny) xd. Thickness direction phase difference Rth is represented by Rth = (nx-nz) xd. In addition, Nz coefficient is represented by Nz = (nx-nz) / (nx-ny) (However, the refractive index of the slow axis direction, the fast axis direction, and the thickness direction of a film is set to nx, ny, nz, respectively, and d (nm) is taken as the thickness of a film. The slow axis direction is a direction in which the refractive index in the film surface is maximized.

On the other hand, by using the polyester film which has a phase difference whose front retardation is 40 nm or more and / or thickness direction retardation is 80 nm or more, you can make the polarizer protective film combine the function of a retardation plate. In that case, a front phase difference and a thickness direction phase difference can be suitably adjusted to the value required for optical compensation as a phase difference plate. As such a retardation plate, a stretched polyester film can be used suitably.

Moreover, the polyester film E which has another phase difference value in the one main surface side and the other main surface side of the polarizer P can be used. For example, when forming a liquid crystal display device, as a polyester film arrange | positioned between a polarizer and a liquid crystal cell, ie, inside, a non-stretched polyester film is used, in other words, an outer side, in order not to change a polarization state. As a polyester film arrange | positioned at, in order to ensure intensity | strength, the structure, such as using a stretched polyester film, can be employ | adopted.

The phase difference plate satisfies the relationship of nx = ny> nz, nx> ny> nz, nx> ny = nz, nx> nz> ny, nz = nx> ny, and nz> nx> ny and nz> nx = ny. It can select and use according to various uses. In addition, ny = nz includes not only the case where ny and nz are exactly the same, but also the case where ny and nz are substantially the same.

For example, in the retardation plate satisfying nx> ny> nz, it is preferable to use the thing which satisfy | fills 40-100 nm, thickness direction retardation 100-320 nm, and Nz coefficient 1.8-4.5. For example, in the retardation plate (positive A plate) which satisfies nx> ny = nz, it is preferable to use the thing whose front retardation satisfy | fills 100-200 nm. For example, in the retardation plate (negative A plate) which satisfies nz = nx> ny, it is preferable to use the thing whose front retardation satisfy | fills 100-200 nm. For example, in the retardation plate satisfying nx> nz> ny, it is preferable to use the thing whose front retardation is 150-300 nm and Nz coefficient satisfy | fills more than 0 and 0.7 or less. As described above, for example, one satisfying nx = ny> nz, nz> nx> ny, or nz> nx = ny can be used.

(Lamination of Polarizer and Polyester Film)

Although it is sufficient if lamination | stacking of the polarizer P and the polyester film E in which the easily bonding layer H was formed, and at least one polyester film E is laminated | stacked by the adhesive bond layer G, it is shown in FIG.1 (a) from a light utilization efficiency viewpoint. As mentioned above, it is preferable that both polyester films E are laminated | stacked with the polarizer P through the adhesive bond layer G.

[Stacked form b]

In FIG.1 (b), the polyester film E in which the easily bonding layer H was formed is laminated | stacked on one main surface of the polarizer P, and the transparent film T other than polyester is laminated | stacked as the protective film on the other main surface of the polarizer P. In FIG. Form.

(Transparent film)

The transparent film T other than polyester is not specifically limited, Arbitrary things can be used. As a material of such a transparent film, the thermoplastic resin which is excellent in transparency, mechanical strength, thermal stability, moisture barrier property, isotropy, etc. is used, for example. Specific examples of such thermoplastic resins include cellulose resins such as triacetyl cellulose, polyester resins, polyether sulfone resins, polysulfone resins, polycarbonate resins, polyamide resins, polyimide resins, and polyolefins. Resins, (meth) acrylic resins, cyclic olefin resins (norbornene resins), polyarylate resins, polystyrene resins, polyvinyl alcohol resins, and mixtures thereof. As the transparent film T, thermosetting resins such as (meth) acrylic, urethane, acrylurethane, epoxy, and silicone, or ultraviolet curable resins can also be used. In the transparent film T, one or more types of arbitrary appropriate additives may be contained. As an additive, a ultraviolet absorber, antioxidant, a lubricating agent, a plasticizer, a mold release agent, a coloring inhibitor, a flame retardant, a nucleating agent, an antistatic agent, a pigment, a coloring agent, etc. are mentioned, for example. Content of the said thermoplastic resin in the transparent film T becomes like this. Preferably it is 50-100 weight%, More preferably, it is 50-99 weight%, More preferably, it is 60-98 weight%, Especially preferably, it is 70-97 weight% . When content of the said thermoplastic resin in transparent film T is 50 weight% or less, there exists a possibility that the high transparency etc. which a thermoplastic resin originally has may not be fully expressed.

Among them, it is preferable to use at least one selected from cellulose resin, polycarbonate resin, cyclic olefin resin and (meth) acrylic resin from the viewpoint of transparency and optical isotropy from the viewpoint of transparency.

As cellulose resin, the cellulose ester in which the hydroxyl group of cellulose acylated by fatty acid is used suitably. Specific examples of such cellulose esters include triacetyl cellulose, diacetyl cellulose, tripropionyl cellulose, dipropionyl cellulose, and the like. Among these, triacetyl cellulose is particularly preferable. Many products of triacetyl cellulose are commercially available, and are advantageous in terms of availability and cost. As an example of the commercial item of a triacetyl cellulose, brand names "UV-50", "UV-80", "SH-80", "TD-80U", "TD-TAC", "UZ-TAC" by the Fujifilm company, "KC series" by Konica Corporation, etc. are mentioned. In general, these triacetyl cellulose has an in-plane retardation Re almost zero, but the thickness retardation Rth has a thickness of about 60 nm.

Moreover, the cellulose resin film with a small thickness direction retardation is obtained by processing the said cellulose resin, for example. For example, base films, such as polyethylene terephthalate, polypropylene, and stainless steel which apply | coated the solvent, such as cyclopentanone and methyl ethyl ketone, are bonded to a general cellulose resin film, and are heat-dried (for example, 80-80). About 3 to 10 minutes at 150 ° C.), and then peeling off the base film; A solution obtained by dissolving norbornene-based resin and (meth) acrylic resin in a solvent such as cyclopentanone and methyl ethyl ketone is applied to a common cellulose resin film and dried by heating (for example, 3 to 10 at 80 to 150 ° C). Minutes), and then a method of peeling the coated film.

Moreover, as a cellulose resin film with a small thickness direction retardation, the resin film of the cellulose ester which controlled substitution degree can be used. In the triacetyl cellulose generally used, although the degree of acetic acid substitution is about 2.8, preferably Rth can be made small by controlling the degree of acetic acid substitution to 1.8 to 2.7. Rth can be controlled small by adding plasticizers, such as dibutyl phthalate, p-toluenesulfonanilide, and acetyl triethyl citrate, to the said fatty acid cellulose resin. The amount of plasticizer added is preferably 40 parts by weight or less, more preferably 1 to 20 parts by weight, still more preferably 1 to 15 parts by weight with respect to 100 parts by weight of fatty acid cellulose resin.

As a specific example of cyclic olefin resin, Preferably it is norbornene-type resin. Cyclic olefin resin is a general term for resin superposed | polymerized using a cyclic olefin as a polymerization unit, For example, Unexamined-Japanese-Patent No. 1-240517, Unexamined-Japanese-Patent No. 3-14882, and Unexamined-Japanese-Patent No. 3- The resin described in the 122-137 publication etc. are mentioned. Specific examples include ring-opening (co) polymers of cyclic olefins, addition polymers of cyclic olefins, α-olefins such as cyclic olefins, ethylene and propylene, copolymers thereof (typically random copolymers), and unsaturated carboxylic acids and Graft polymers modified with their derivatives, and their hydrides. A norbornene-type monomer is mentioned as a specific example of cyclic olefin.

As cyclic olefin resin, various products are marketed. As a specific example, the brand name "Xeonex", the product made by Nippon Xeon Kabushiki Kaisha, "Zeonoa", the brand name "Aton" made by JSR Kabushiki Kaisha, the product name "topas" made by Ticona (TICONA), Mitsui Kagaku Kabushiki Kaisha Brand name "Apel" etc. are mentioned.

As (meth) acrylic-type resin, Tg (glass transition temperature) becomes like this. Preferably it is 115 degreeC or more, More preferably, it is 120 degreeC or more, More preferably, it is 125 degreeC or more, Especially preferably, it is 130 degreeC or more. When Tg is 115 degreeC or more, it can become the thing excellent in the durability of a polarizing plate. Although the upper limit of Tg of the said (meth) acrylic-type resin is not specifically limited, From a moldability viewpoint, Preferably it is 170 degrees C or less. From (meth) acrylic-type resin, the film whose in-plane phase difference Re and thickness direction phase difference Rth are almost zero can be obtained.

As (meth) acrylic-type resin, arbitrary appropriate (meth) acrylic-type resin can be employ | adopted within the range which does not impair the effect of this invention. For example, poly (meth) acrylic acid esters, such as polymethyl methacrylate, methyl methacrylate- (meth) acrylic acid copolymer, methyl methacrylate- (meth) acrylic acid ester copolymer, methyl methacrylate-methyl ester- (Meth) acrylic acid copolymer, (meth) acrylic acid methyl-styrene copolymer (MS resin etc.), a polymer having an alicyclic hydrocarbon group (for example, methyl methacrylate-cyclohexyl copolymer, methyl methacrylate) -(Meth) acrylic acid norbornyl copolymer, etc.) is mentioned. Preferably, poly (meth) acrylic-acid C1-6 alkyl, such as methyl poly (meth) acrylate, is mentioned. More preferably, methyl methacrylate resin which has methyl methacrylate as a main component (50-100 weight%, Preferably 70-100 weight%) is mentioned.

As a specific example of (meth) acrylic-type resin, For example, (meth) which has a ring structure in the molecule | numerator of Mitsubishi Rayon Co., Ltd. Acripet VH, Acripet VRL20A, Unexamined-Japanese-Patent No. 2004-70296, ) Acrylic resin, high Tg (meth) acrylic resin system obtained by intramolecular crosslinking and intramolecular cyclization reaction is mentioned.

As (meth) acrylic-type resin, you may use (meth) acrylic-type resin which has a lactone ring structure. It is because it has high mechanical strength by high heat resistance, high transparency, and biaxial stretching.

As (meth) acrylic-type resin which has a lactone ring structure, Unexamined-Japanese-Patent No. 2000-230016, Unexamined-Japanese-Patent No. 2001-151814, Unexamined-Japanese-Patent No. 2002-120326, Unexamined-Japanese-Patent No. 2002-254544 (Meth) acrylic-type resin which has a lactone ring structure as described in Unexamined-Japanese-Patent No. 2005-146084, etc. is mentioned.

The (meth) acrylic resin having a lactone ring structure preferably has a ring-like structure represented by the following general formula (1).

In the formula, R ¹ , R ² and R ³ each independently represent a hydrogen atom or an organic residue having 1 to 20 carbon atoms. In addition, the organic residue may contain an oxygen atom.

The content rate of the lactone ring structure represented by General formula (1) in the structure of the (meth) acrylic-type resin which has a lactone ring structure becomes like this. Preferably it is 5-90 weight%, More preferably, it is 10-70 weight%, More preferably, 10 To 60% by weight, particularly preferably 10 to 50% by weight. When the content rate of the lactone ring structure represented by General formula (1) in the structure of (meth) acrylic-type resin which has a lactone ring structure is less than 5 weight%, there exists a possibility that heat resistance, solvent resistance, and surface hardness may become inadequate. When the content rate of the lactone ring structure represented by General formula (1) in the structure of (meth) acrylic-type resin which has a lactone ring structure is more than 90 weight%, molding workability may become inadequate.

The (meth) acrylic resin having a lactone ring structure preferably has a weight average molecular weight (also called a weight average molecular weight) of 1000 to 2000000, more preferably 5000 to 1000000, still more preferably 10000 to 500000, particularly preferably Preferably 50000 to 500000. When the weight average molecular weight is out of the above range, molding processability may be insufficient.

Tg of (meth) acrylic-type resin which has a lactone ring structure becomes like this. Preferably it is 115 degreeC or more, More preferably, it is 120 degreeC or more, More preferably, it is 125 degreeC or more, Especially preferably, it is 130 degreeC or more. Since Tg is 115 degreeC or more, when it is put in a polarizing plate as transparent film T (polarizer protective film) in the polarizing plate of this invention, it becomes excellent in durability. Although the upper limit of Tg of (meth) acrylic-type resin which has the said lactone ring structure is not specifically limited, From a viewpoint of moldability etc., Preferably it is 170 degrees C or less.

As for the (meth) acrylic-type resin which has a lactone ring structure, the higher the total light transmittance measured by the method according to ASTM-D-1003 of the molded article obtained by injection molding, the more preferable, Preferably it is 85% or more, More preferably Preferably at least 88%, more preferably at least 90%. Total light transmittance is an index of transparency, and transparency may fall when total light transmittance is less than 85%.

Moreover, as transparent film T, the polymer film of Unexamined-Japanese-Patent No. 2001-343529 (WO01 / 37007), for example, (I) thermoplastic resin which has a substituted and / or unsubstituted imide group in a side chain, ( II) The resin composition containing the thermoplastic resin which has a substituted and / or unsubstituted phenyl and a nitrile group in a side chain is mentioned. 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 may be a film composed of a mixture of resin compositions and the like. Since these films have a small retardation and a small photoelastic coefficient, problems such as unevenness due to distortion of the polarizing plate can be solved, and the moisture permeability is small, so the humidification durability is excellent.

Although the thickness of the transparent film T can be suitably determined, like the said polyester film, 5-500 micrometers is preferable, 5-200 micrometers is more preferable, 10-150 micrometers is still more preferable.

As the transparent film T, any one of birefringence which does not change a polarization state and which acts as a retardation plate can be used.

When using what acts as a retardation plate for the transparent film T, as the polymer material, for example, polyvinyl alcohol, polyvinyl butyral, polymethyl vinyl ether, polyhydroxyethyl acrylate, hydroxyethyl cellulose, hydrate Roxypropyl cellulose, methyl cellulose, polycarbonate, polyarylate, polysulfone, polyethylene terephthalate, polyethylene naphthalate, polyether sulfone, polyphenylene sulfide, polyphenylene oxide, polyallyl sulfone, polyamide, polyimide , Polyolefins, polyvinyl chlorides, cellulose resins, cyclic olefin resins (norbornene-based resins), or various copolymers of binary or ternary systems thereof, graft copolymers, blends, and the like. These high molecular materials become an orientation substance (stretched film) by extending | stretching etc.

Examples of the liquid crystal polymer include various main chain or side chains in which the conjugated linear atomic group (mesogen) for imparting liquid crystal alignment is introduced into the main chain or side chain of the polymer. As a specific example of a main-chain liquid crystal polymer, the nematic oriented polyester liquid crystal polymer, a discotic polymer, a cholesteric polymer, etc. of the structure which couple | bonded the mesogenic group in the spacer part which provides flexibility are mentioned, for example. . Specific examples of the side chain type liquid crystal polymer include a polysiloxane, polyacrylate, polymethacrylate, or polymalonate as a main chain skeleton, and a para-substituted cyclic compound having a nematic orientation impartability via a spacer portion composed of a conjugated atomic group as a side chain. The thing which has the mesogenic part which consists of units, etc. are mentioned. These liquid crystal polymers, for example, by rubbing the surface of a thin film, such as polyimide or polyvinyl alcohol formed on a glass plate, by depositing a silicon oxide obliquely, such as a solution of the liquid crystal polymer on the surface It expands and heat-processes.

The retardation plate may have an appropriate 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, and stacking two or more kinds of retardation plates. To control optical characteristics such as retardation. Moreover, the film which has the said phase difference can also be separately bonded to the transparent film which does not have a phase difference, and can provide the said function.

Moreover, from the point which achieves the wide viewing angle of favorable visibility, the optical compensation retardation plate etc. which supported the optically anisotropic layer which consists of the alignment layer of a liquid crystal polymer, especially the diagonal alignment layer of a discotic liquid crystal polymer, etc. You can also use

Lamination | stacking of polarizer P and polyester film E is performed through an adhesive bond layer as mentioned above. Moreover, it is preferable to perform lamination | stacking of the polarizer P and the transparent film T similarly through an adhesive bond layer. Also in the lamination | stacking of the polarizer P and the transparent film T, it is preferable to use the resin solution containing polyvinyl alcohol-type resin, a crosslinking agent, and a metal compound colloid from a viewpoint of suppressing generation | occurrence | production of an uneven | corrugated defect. In addition, at the time of lamination | stacking adhesion of the polarizer P and the transparent film T, you may surface-treat the adhesive surface of the transparent film T before apply | coating an adhesive agent. As a surface modification process, the method of forming said thing as an easily bonding layer of a polyester film, corona treatment, a plasma treatment, a primer treatment, a saponification process, etc. can be performed.

[Stacked form c]

FIG.1 (c) is a form in which the polyester film E is laminated | stacked on one main surface of the polarizer P, and the film is not laminated | stacked on the other main surface. In this form, lamination of the polarizer P and the polyester film E is performed via the adhesive bond layer G as mentioned above.

[Other optical layers]

(Formation of Surface Treatment Layer)

As for the polarizing plate of this invention, when the at least 1 polyester film E in which the easily bonding layer H was formed in at least one main surface, and the polarizer P are laminated | stacked, the form was illustrated to said laminated form (a)-(c). It is not limited to this, Any optical layer can be added. As such an optical layer, for example, a hard coating layer, an anti-reflective treatment, anti-sticking, or diffusion to antiglare are provided on the main surface of the polyester film E and / or the transparent film T, on which the polarizer P is not laminated. What performed the process can be used.

The hard coating treatment is performed for the purpose of preventing scratches on the surface of the polarizing plate. For example, the polyester film E and / or a hardened film having excellent hardness, sliding properties, and the like due to suitable ultraviolet curable resins such as acrylic and silicone. It can be formed by the method added to the surface of the transparent film T, etc. The antireflection treatment is carried out for the purpose of preventing the reflection of external light on the surface of the polarizing plate, and can be achieved by forming a conventional antireflection film or the like. In addition, a sticking prevention process is performed in order to prevent adhesion with an adjacent layer (for example, the diffuser plate of a backlight side).

The antiglare treatment is performed for the purpose of preventing external light from reflecting on the surface of the polarizing plate and impairing the visibility of the polarizing plate transmitted light. For example, a roughening method or transparent fine particles by a sand blasting method or an embossing processing method. It can form by providing a fine uneven structure to the surface of the said polyester film E and / or the transparent film T by a suitable method, such as the compounding method of the. As fine particles to be contained for formation of the surface fine uneven structure, for example, conductive particles made of silica, alumina, titania, zirconia, tin oxide, indium oxide, cadmium oxide, antimony oxide, or the like having an average particle diameter of 0.5 to 20 µm Transparent microparticles | fine-particles, such as organic type microparticles | fine-particles which consist of some inorganic fine particles, a crosslinked or uncrosslinked polymer, etc. are used. When forming a surface fine uneven structure, the usage-amount of microparticles | fine-particles is about 2 to 70 weight part generally 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 polarizing plate transmitted light to enlarge the time and the like.

The antireflection layer, the anti-sticking layer, the diffusion layer, the antiglare layer, and the like may be formed on the polyester film E and / or the transparent film T itself, or may be separately formed as an optical layer. .

In addition, as an example of the optical layer which can be applied to the polarizing plate of this invention, a brightness improving film, a reflection layer, a retardation plate, etc. are mentioned.

(Luminance improvement film)

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 enters by a backlight such as a liquid crystal display device or reflection from the back surface side, and transmits other light, thereby improving brightness. What laminated | stacked the film with the polarizing plate is made to inject light from a light source such as a backlight to obtain transmitted light in a predetermined polarization state, and light other than the predetermined polarization state is reflected without being transmitted. The light reflected by this brightness enhancing film is further inverted through a reflecting layer or the like formed on the rear side thereof, and reincident to the brightness enhancing film, and part or all of the light is transmitted as light in a predetermined polarization state to increase the amount of light passing through the brightness enhancing film. In addition, the luminance can be improved by supplying polarized light that is hardly absorbed by the polarizer and increasing the amount of light that can be used for image display such as a liquid crystal display. Although the polarizing plate which bonded the polarizing plate and the brightness enhancement film is often provided and used in the backlight side of a liquid crystal cell, as disclosed in WO2006 / 038404 international publication brochure, it can also be provided and used in the visual recognition side of a liquid crystal cell. .

As the brightness enhancing film, for example, a cholesteric liquid crystal polymer exhibiting a property of transmitting linearly polarized light of a predetermined polarization axis and reflecting other light, such as a multilayer laminate of a dielectric thin film or a multilayer laminate of thin film films having different refractive index anisotropy. As supporting the oriented film and the oriented liquid crystal layer on the film substrate, a suitable one can be used, such as exhibiting a characteristic of reflecting either circularly polarized light in the left turn or the right turn and transmitting the other light.

(Reflective layer)

By forming a reflective layer in the polarizing plate of this invention, it can be set as a reflective polarizing plate. The reflective polarizing plate is for forming a liquid crystal display device of a type that reflects and displays incident light from the viewing side (display side) on the polarizing plate, and can eliminate the built-in of a light source such as a backlight, thereby reducing the thickness of the liquid crystal display device. It has advantages such as being easy to plan. 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 metal etc. in one surface of a polarizing plate via said polyester film E, transparent film T, etc. as needed.

In addition, a semi-transmissive polarizing plate can be obtained by making it the semi-transmissive reflective layer, such as the half-mirror which reflects light in the reflective layer, and permeate | transmits in the above. The semi-transmissive polarizing plate is usually provided on the back side (backlight side) of the liquid crystal cell, and when the liquid crystal display device or the like is used in a relatively bright atmosphere, the incident light from the viewing side (display side) is reflected to display an image. In a relatively dark atmosphere, a liquid crystal display device of a type for displaying an image or the like can be formed using built-in light sources such as a backlight built in the back side 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.

[Difference plate]

As the retardation plate, the above-mentioned ones such as a birefringent film obtained by uniaxially or biaxially stretching a polymer material, an alignment film of the liquid crystal polymer, and an alignment layer of the liquid crystal polymer supported by a film can be used.

Thus, an elliptical polarizing plate or circular polarizing plate is demonstrated as an example of the laminated polarizing plate in which the retardation plate was laminated | stacked on the polarizing plate. 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 a phase difference plate for converting linearly polarized light into circularly polarized light or for converting circularly polarized light into linearly polarized light. The half wave plate (also referred to as λ / 2 plate) is usually used to change the polarization direction of linearly polarized light.

An elliptical polarizing plate is effectively used for compensating (preventing) coloration (blue or yellow color) caused by birefringence of a liquid crystal layer of a super twist nematic (STN) type liquid crystal display device to perform black and white display without the coloration. In addition, it is preferable to control the three-dimensional refractive index because the coloring degree generated when the screen of the liquid crystal display device is viewed from the inclined direction can be compensated (prevented). The circular polarizing plate is effectively used, for example, when arranging the color tone of an image of a reflection type liquid crystal display device in which an image becomes color display, and also has a function of antireflection.

In addition, said elliptical polarizing plate and reflective elliptical polarizing plate laminate | stack a polarizing plate or a reflective linear polarizing plate, and a phase difference plate in a suitable combination. Such elliptical polarizing plates and the like can be formed by separately stacking them sequentially in the manufacturing process of the liquid crystal display device so as to be a combination of the (reflective) polarizing plate and the retardation plate, but as described above, optically compensated polarizing plates such as elliptical polarizing plates in advance. What is set is the advantage that the stability of quality, lamination workability, etc. are excellent and the manufacturing efficiency of a liquid crystal display device etc. can be improved.

The visual compensation film is a film for widening a viewing angle so that an image can be seen comparatively clearly, even when the screen of a liquid crystal display device is seen from a slightly oblique direction rather than perpendicular to a screen. As such a visual compensation retardation plate, it consists of what supported the alignment layers, such as a liquid crystal polymer, on orientation films, such as a retardation plate and a liquid crystal polymer, and a transparent base material. A normal retardation plate is a polymer film having birefringence biaxially stretched in the plane direction or a plane direction in the retardation plate used as a visual compensation film, whereas a birefringence polymer film uniaxially stretched in the plane direction is used. A biaxially stretched film such as a birefringent polymer or a diagonally oriented film is used which is uniaxially stretched and also controls the refractive index in the thickness direction stretched in the thickness direction. As the diagonally oriented film, for example, a heat-shrink film is adhered to the polymer film, and the polymer film is stretched or / and shrunk under the action of the shrinkage force by heating, or the liquid crystal polymer is oriented at an angle. have. As the raw material polymer of the retardation plate, the same polymer as that described in the above retardation plate is used, and for the purpose of preventing the coloring due to the change of time based on the phase difference by the liquid crystal cell, the expansion of the viewing angle of a good viewer, and the like. One suitable one can be used.

[Lamination of Optical Layers]

Although optical layers, such as a brightness improving film, a reflection layer, and a phase difference plate, can be formed by the method of separately laminating | stacking sequentially in the manufacturing process of a liquid crystal display device, etc., what laminated | stacked previously and set it as the laminated polarizing plate is stability of quality and assembly work. It is excellent in the etc. and 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 these lamination | stacking, the optical axis (the slow axis of a phase difference film, the absorption axis of a polarizer, etc.) of each optical layer can be made into a suitable arrangement angle according to the target phase difference characteristic etc ..

(Adhesive layer)

In the polarizing plate of this invention, each optical layer can also be laminated | stacked, or the adhesion layer for adhere | attaching with other members, such as a liquid crystal cell, can also be provided. 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 rubber or a polymer such as fluorine-based polymer may be appropriately selected. Can be used. In particular, an acrylic adhesive has excellent optical transparency, exhibits proper wettability, cohesiveness, and adhesive adhesion characteristics, and can be preferably used with excellent weather resistance, heat resistance, and the like.

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

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

Laying an adhesion layer on one side or both sides of a polarizing plate and another optical layer can be performed by a suitable method. As an example, about 10 to 40weight% of the adhesive solution which melt | dissolved or disperse | distributed or disperse | distributed the 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, for example, it is a flexible system Or a method of directly laying on a polarizing plate or an optical film by a suitable development method such as a coating method, or a method of forming an adhesive layer on a separator according to the above, and moving it onto a laminated optical film or other optical layers, etc. Can be mentioned.

The pressure-sensitive adhesive layer may be formed on one side or both sides of the laminated optical film or the other optical layer as an overlapping layer of another composition or kind. Moreover, when formed in both surfaces, it can also be set as adhesive layers, such as another composition, a kind, thickness, etc. in the front and back of a polarizing plate and 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.

(Release film)

It is preferable that a release film (separator) is temporarily bonded and covered with respect to the exposed surface of an adhesion layer for the purpose of the contamination prevention, etc., until it uses for practical use. Thereby, contact with an adhesion layer can be prevented in a usual handling state. As the release film, 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 or a metal foil, and a suitable thin body such as a laminate thereof may be silicone-based or long-chain. Conventional suitable ones, such as those coated with a suitable release agent such as alkyl, fluorine or molybdenum sulfide, can be used.

In addition, in this invention, each layer, such as a polarizer which forms said polarizing plate, a polyester film, a transparent film, another optical layer, an adhesive agent, an adhesion layer, is a salicylic acid ester type compound, or a benzophenol type, for example. The thing which gave ultraviolet absorption ability by the method, such as a process with a ultraviolet absorber, such as a compound, a benzotriazole type compound, a cyanoacrylate type compound, and a nickel complex salt type compound, may be sufficient.

[Image display device]

The polarizing plate of this invention can be used suitably for formation of image display apparatuses, such as a liquid crystal display device and an organic electroluminescence display.

(Liquid crystal display device)

Formation of a liquid crystal display device can be performed according to the prior art. That is, a liquid crystal display device generally includes a liquid crystal cell and a polarizing plate, and, if necessary, suitable components such as a diffusion plate, an antiglare layer, an antireflection film, a protective plate, a prism array, a lens array sheet, a light diffusion plate, a backlight, and the like. It is formed by arranging one or two or more layers at appropriate positions and embedding a driving circuit. In formation of a liquid crystal display device, there is no limitation in particular except the point which uses the polarizing plate by this invention, and it can follow conventionally. Also about a liquid crystal cell, the thing of arbitrary types, such as a TN type, STN type, (pi) type, can be used, for example.

The polarizing plate of this invention can be provided in one side or both sides of a liquid crystal cell. When providing a polarizing plate in both sides, they may be the same and may differ. In particular, it is preferable that the polarizing plate of this invention is integrated together with a liquid crystal cell via an adhesive etc.

(Organic EL display device)

Subsequently, an organic electroluminescent device (organic EL display device) will be described. 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 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 is 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 light emitting 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 similar to that of a general diode, and as can be expected from this, the current and the emission 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 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 easily inject electrons and increase luminous efficiency, it is important to use a material having a small 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 an extremely 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, light incident on the surface of the transparent substrate during non-emission, and transmitted through the transparent electrode and the organic light emitting layer and reflected by the metal electrode again comes out to the surface side of the transparent substrate. The display surface looks like a mirror.

An organic EL display device comprising an organic electroluminescent emitter comprising a transparent electrode on the front side of an 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, wherein the organic EL display device is transparent. While providing a polarizing plate on the surface side of an electrode, a phase difference plate can be provided 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, when the phase difference plate is constituted by a quarter wave plate, and the angle between the polarization direction of the polarizing plate and the phase difference plate is adjusted to π / 4 (90 °), 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 a phase difference plate, but in particular, when the phase difference plate is a quarter wave plate, and the angle between the polarization direction of the polarizing plate and the phase difference plate is π / 4 (90 °), it becomes circularly polarized light. .

This circularly polarized light transmits a transparent substrate, a transparent electrode, and an organic thin film, reflects on a metal electrode, permeates an organic thin film, a transparent electrode, and a transparent substrate again, and becomes linearly polarized light again to a 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 the metal electrode can be completely shielded.

In order to obtain this circularly polarized light, for example, by using the laminated optical film of the present invention in which a quarter wave plate is laminated as an optical compensation layer, reflection of external light is suppressed and an organic EL display device having high visibility even in the outdoor can be obtained. Can be. Moreover, such an organic electroluminescence display is also preferable at the point which is excellent in abrasion resistance similarly to the liquid crystal display device mentioned above.

When using the polarizing plate of this invention for such an organic electroluminescence display, either the structure which uses a polyester film as a quarter wave plate as an optical compensation layer, and the structure which uses a polyester film as a polarizer protective film simply It can be adopted.

[Formation method of liquid crystal display device]

[Formation method of conventional liquid crystal display device]

By the way, in formation of image display apparatuses, such as a liquid crystal display device and an organic electroluminescence display, especially the film laminated | stacked on one main surface and the other main surface of the polarizer P like the said laminated | multilayer form b (FIG.1 (b)) is When using the polarizing plate of the structure which differs, or is laminated | stacked only on one main surface of the polarizer P like the said laminated form c (FIG.1 (c)), the other side from the main surface of the side on which the polyester film E is laminated | stacked In the principal plane of, the stress applied to the film interface of the polarizer P may be different. That is, since the layer structure is different in the front and back of the polarizer P, the external stress applied to the polarizer may be different in the front and back of the film. Due to the difference in external stress, the film tends to have flexibility. Thus, the film which was easy to bend was difficult to process with the image display apparatus as shown below at the conventional manufacturing process.

The manufacturing process of the conventional imaging device is largely divided into the manufacturing process in an optical film manufacture manufacturer, and the manufacturing process in a panel processing maker, as shown conceptually in FIG. First, in an optical film manufacturer, optical films, such as a polarizing plate, are manufactured as a roll raw material of a long (strip-shaped) sheet-like product (# 1). Subsequently, the roll raw material is slit into a predetermined size (size according to the size of the optical display unit) (# 2). Subsequently, the slit elongated raw material is cut to a certain length in accordance with the size of the optical display unit to be bonded, such as a liquid crystal cell or an organic EL panel (# 3). Subsequently, the sheet-like product (optical film) of a sheet cut to a certain length is visually inspected (# 4). As this inspection method, the visual inspection and the inspection using a well-known defect inspection apparatus are mentioned, for example. The defects mean, for example, contamination or scratches on the surface or the inside, scratches, defects, irregularities, bubbles, foreign matters, etc. in which foreign matters are inherited. Subsequently, the finished product is inspected (# 5). The finished product inspection is an inspection which conforms to a strict quality standard rather than an appearance inspection. Subsequently, four end surfaces of the sheet-shaped product are processed by the end surface (# 6). This is done in order to prevent the adhesive or the like from protruding from the end face during transportation. Subsequently, in a clean room environment, the sheet-like product is cleanly packaged (# 7). Subsequently, the package is packaged for transportation (transport packaging) (# 8). As described above, a single sheet-like product is manufactured and transported to a panel processing maker.

In the panel processing maker, the sheet-like product which has been transported is packed and dismantled (# 11). Subsequently, visual inspection is carried out to check for scratches, dirt, etc. which occurred during transportation or during package dismantling (# 12). The sheet-like product of the sheet determined good quality in the inspection is returned to the next step. In addition, this visual inspection may be omitted. The optical display unit (for example, the liquid crystal cell which is the glass substrate unit in which the liquid crystal cell was enclosed) in which the sheet-like product is bonded is manufactured beforehand, and the optical display unit is washed before the bonding process (# 13).

Subsequently, the sheet-like product and the optical display unit (liquid crystal cell) are bonded (# 14). The release film is peeled off from the sheet-shaped product leaving the pressure-sensitive adhesive layer, and the pressure-sensitive adhesive layer is bonded to one surface of the optical display unit. In addition, the other surface of an optical display unit can be joined similarly. When bonding to both, the optical film of the same structure may be bonded to each surface of the optical display unit, and the optical film of a different structure may be bonded. Subsequently, inspection of the bonded state and defect inspection are performed (# 15). The optical display unit judged good quality by this inspection is conveyed by a mounting process, and is mounted in an image display apparatus (# 16). On the other hand, the rework process is performed for the optical display unit in which the defective article was determined (# 17). In the rework process, the optical film is peeled off from the optical display unit. In the reworked optical display unit, an optical film is newly bonded (# 14).

When the above conventional manufacturing process is applied to a film which is easy to bend, in the process of (# 1) and (# 2) in which a polarizing plate exists in roll shape, since it spans between conveyance lines, it curves by the tension. Behavior is suppressed. However, when this is cut | disconnected to a fixed length (# 3), since tension | tensile_strength which suppressed the curvature behavior of a polarizing plate is opened, curvature generate | occur | produces and handling by visual inspection (# 4)-junction with a liquid crystal cell (# 14) This becomes difficult. Furthermore, in the case of the conventional manufacturing process, in addition to the problem of handling due to the above-mentioned flexibility, there is a problem that the manufacturing cost increases because it is a multi-step process such as inspection and packing.

[Production Method by Continuous Method]

Curvature is suppressed by continuously bonding the film formed in such a long roll shape to a liquid crystal cell, unwinding in presence of tension, and can solve this problem. That is, external inspection (# 4), by performing cutting (# 3) and bonding (# 14) to a liquid crystal cell continuously in one place by the fixed length which was performed separately by the optical film manufacturer and the panel processing maker conventionally, Finished goods inspection (# 5), end surface processing (# 6), clean packaging (# 7), transport packing (# 8), packing disassembly (# 11), appearance inspection (# 12) become unnecessary, and The handling problem can also be solved.

Formation of the image display apparatus by such a continuous system comprises the roll raw material preparation process of preparing the long sheet of the polarizing plate of this invention as a roll raw material, and unwinding a sheet product from the said roll raw material, and predetermined | prescribed the said polarizing plate using a cutting means. And a cutting step of bonding the polarizing plate to the optical display unit via the pressure-sensitive adhesive layer after the cutting step of cutting to size and the cutting step. The example is shown below.

[Embodiment 1 (normal cutting method) by a continuous method]

(1) 1st roll raw material preparation process (FIG. 3, S1)

The polarizing plate of this invention shape | molded long is prepared as a 1st roll raw material. This polarizing plate has the 1st optical film 11 in which at least 1 polyester film E and the polarizer P were laminated | stacked, and the easily bonding layer H was formed in at least one main surface, the 1st adhesion layer 14, and a 1st release film Has 12. In addition, the 1st optical film 11 may contain optical layers other than a polyester film and a polarizer. In addition, when the 1st optical film 11 is a structure in which the film is laminated | stacked only on one main surface of the polarizer P like the said laminated | multilayer form c (FIG.1 (c)), the 1st optical film 11 of It is preferable to have the 1st adhesion layer 14 and the 1st release film 12 in the surface on the polarizer P side.

(2) 1st cutting process (FIG. 3, S2)

Subsequently, the first sheet product is released from the prepared first roll raw material, and the first optical film 11 and the first pressure sensitive adhesive layer are not cut by using the cutting means. 14 is cut to a predetermined size. Thereby, the 1st optical film 11 and the 1st adhesive layer 14 can be cut | disconnected, without cutting the 1st release film 12. FIG. Therefore, since the 1st optical film 11 was formed on the 1st release film 12 through the 1st adhesive layer 14, the 1st optical film 11 does not bend. As a cutting means, a laser device, a cutter, other well-known cutting means, etc. are mentioned, for example.

(3) 1st optical film bonding process (FIG. 3, S3)

Subsequently, after removing the said 1st release film 12, the 1st optical film 11 from which the said 1st release film 12 was removed was made into the said 1st adhesive layer 14, after a 1st cutting process. It joins to the optical display unit A through it. Therefore, even when peeling the 1st release film 12, the 1st optical film 11 can be bonded to the optical display unit A in the state in which curvature of the 1st optical film 11 was suppressed. As an optical display unit A, the glass substrate unit of an liquid crystal cell, an organic electroluminescent unit, etc. are mentioned, for example. In addition, the optical display unit A is wash | cleaned previously before bonding.

Each process of these 1st roll raw material preparation process, a 1st cutting process, and a 1st optical film bonding process is performed in a continuous manufacturing line. In the above series of manufacturing steps, the first optical film 11 is bonded to one surface of the optical display unit A. FIG. Hereinafter, the manufacturing process of bonding the 2nd optical film 21 to the other surface is demonstrated.

(4) 2nd roll raw material preparation process (FIG. 3, S4)

The long second sheet product 2 is prepared as a second roll raw material. The laminated structure of the 2nd sheet product 2 has the 2nd optical film 21, the 2nd adhesion layer 24, and the 2nd release film 12a similarly to the case of the said 1st optical film. Moreover, although arbitrary optical films can be used as a 2nd optical film, it is preferable that it is a polarizing plate containing a polarizer.

(5) 2nd cutting process (FIG. 3, S5)

Subsequently, the second sheet product is unwound from the prepared second roll raw material, and the second optical film 21 and the first agent are not cut as in the case of the first optical film without cutting the second release film 12a. 2 The adhesive layer 24 is cut | disconnected to predetermined size.

(6) 2nd optical film bonding process (FIG. 3, S6)

Subsequently, after removing the 2nd release film 12a, the 2nd optical film 21 from which the said 2nd release film 12a was removed was made into the said 2nd adhesive layer 24 after a 2nd cutting process. It interposes and bonds to the surface from which the 1st optical film 11 of the optical display unit A is bonded. Therefore, even when peeling the 2nd release film 12a, the 2nd optical film 21 can be bonded to the optical display unit A in the state in which curvature of the 2nd optical film 21 was suppressed. Thereby, the optical display unit in which the 1st optical film 11 was bonded to one surface of the optical display unit A, the 2nd optical film 21 was bonded to the other surface, and the optical film was formed in both surfaces can be manufactured. .

And each process of a 1st roll raw material preparation process, a 1st cutting process, a 1st optical film bonding process, a 2nd roll raw material preparation process, a 2nd cutting process, and a 2nd optical film bonding process is performed in a continuous manufacturing line. do.

(7) inspection process

Moreover, it is preferable to have an inspection process (FIG. 3, S7) as a continuous process. As an inspection process, although the inspection process which inspects the bonding state and the inspection process which inspects the fault | strain after joining are illustrated, only one inspection may be sufficient but it is preferable to perform both inspection.

(8) mounting process

In the inspection process, the optical display unit A for which the quality was determined is mounted on the image display device. In the case of a defective product determination, a rework process is carried out, the optical film is newly adhered, and continuously inspected, and in the case of a good product determination, the process is carried out to a mounting process, and in the case of a defective product determination, the rework process is carried out again or discarded.

In addition, in embodiment shown above, although the polarizing plate of this invention was used as the 1st optical film 11, the polarizing plate of this invention can also be used as the 2nd optical film 21. Moreover, in FIG. Moreover, the polarizing plate of this invention can also be used for both the 1st optical film 11 and the 2nd optical film 21. FIG.

[Embodiment 2 (skip cut method) by a continuous method]

Next, embodiment of the cutting by the skip cut system which modified embodiment of the 1st cutting process and the 2nd cutting process in embodiment of said cutting by the said normal system is demonstrated.

At one end in the width direction of the first and second roll raw materials, defect information (defect coordinates, types of defects, size, etc.) of the first and second sheet-shaped products is provided in predetermined pitch units (for example, 1000 mm). It may be provided as code information (for example, a QR code and a barcode). In this case, in the first step of cutting, this code information is read and interpreted and cut to a predetermined size in the first and second cutting steps (also called a skip cut) to avoid defects. And the part containing a fault is comprised so that it may be joined to a member which is not a removal or an optical display unit, and is comprised so that the sheet-like product of the good quality determination cut | disconnected to a predetermined magnitude | size may be joined to an optical display unit. Thereby, the yield of an optical display unit can be improved significantly and the frequency which requires the rework process # 17 can be reduced. The flowchart of the manufacturing method of the image display apparatus which applied this cutting method (skip cut system) to FIG. 4 is shown.

(1) 1st roll raw material preparation process (FIG. 4, S1)

As in the case of the said normal cutting system, the polarizing plate of this invention provided with the 1st adhesion layer 14 and the 1st release film 12 is prepared as a 1st roll raw material.

(2) 1st release film removal process (FIG. 4, S61)

Subsequently, the first sheet product is released from the prepared first roll raw material, and the first release film 12 is removed. As a removal method of the 1st release film 12, for example, the method of peeling and peeling continuously by winding a peeled film to a roll, the method of cutting only a 1st release film by a predetermined size unit, and peeling and removing with an adhesive tape, The removal method of another process, etc. are mentioned.

(3) 1st defect inspection process (FIG. 4, S62)

Subsequently, a defect inspection is performed after a 1st release film removal process. The defect inspection of the 1st optical film 11 can be performed, without having to consider defects, such as a foreign material and a flaw etc. affixed or inherent to the 1st release film 12, or the phase difference inherent in a 1st release film. The defect inspection can apply a well-known method.

(4) 2nd release film bonding process (FIG. 4, S63)

Subsequently, after the 1st defect inspection process, the 2nd release film 22 is bonded to the said 1st optical film 11 through the said 1st adhesive layer 14. It is preferable to carry out planarity so that bubble mixing, such as a bubble, may not arise at the time of joining.

(5) 1st cutting process (FIG. 4, S64)

Subsequently, after the second release film bonding step, the first optical film 11 and the first pressure sensitive adhesive layer 14 are cut to a predetermined size without cutting the second release film 22 using a cutting means. do. Thereby, the 1st optical film 11 and the 1st adhesive layer 14 can be cut | disconnected, without cutting the 2nd release film 22. FIG. Therefore, since the 1st optical film 11 is formed on the 2nd release film 22 via the 1st adhesive layer 14, the 1st optical film 11 does not bend. As a cutting means, a laser device, a cutter, other well-known cutting means, etc. are mentioned, for example.

(6) 1st optical film bonding process (FIG. 4, S65)

Then, the 1st optical film 11 is bonded to the optical display unit A, removing the said 2nd release film 22 similarly to the case of the said normal cutting system.

Each of these first roll raw material preparation step, first release film removal step, first defect inspection step, second release film bonding step, first cutting step, and first optical film bonding step is performed in a continuous production line. do. In the above series of manufacturing steps, the first optical film 11 is bonded to one surface of the optical display unit A. FIG.

(7) 2nd roll raw material preparation process (FIG. 4, S4)

The long second sheet product 2 is prepared as a second roll raw material. The laminated structure of the 2nd sheet product 2 has the 2nd optical film 21, the 3rd release film 12a, and the surface protection film 23 similarly to the case of the said 1st optical film.

(8) 3rd release film removal process (FIG. 4, S66)

Subsequently, the second sheet product is released from the prepared second roll raw material, and the third release film 12a is removed in the same manner as in the first optical film.

(9) 2nd defect inspection process (FIG. 4, S67)

Then, after a 3rd release film removal process, a fault test is performed similarly to the case of the said 1st optical film.

(10) 4th release film bonding process (FIG. 4, S68)

Subsequently, after the second defect inspection step, the fourth release film 22a is bonded to the second optical film 21 via the second pressure sensitive adhesive layer 24 in the same manner as in the case of the first optical film. do.

(11) 2nd cutting process (FIG. 4, S69)

Subsequently, in the same manner as in the case of the first optical film, after the fourth release film bonding step, the second optical film 21 and the first agent are not cut using the cutting means without cutting the fourth release film 22a. 2 The adhesive layer 24 is cut | disconnected to predetermined size.

(12) 2nd optical film bonding process (FIG. 4, S70)

Subsequently, after the second cutting step, the second optical film 21 from which the fourth release film 22a is removed while removing the fourth release film 22a in the same manner as in the case of the normal cutting method. Is bonded to a surface different from the surface to which the first optical film 11 of the optical display unit A is bonded via the second pressure sensitive adhesive layer 24.

And 1st roll raw material preparation process, 1st release film removal process, 1st defect inspection process, 2nd release film bonding process, 1st cutting process, 1st optical film bonding process, 2nd roll raw material preparation process, 3rd Each process of a release film removal process, a 2nd defect inspection process, a 4th release film bonding process, a 2nd cutting process, and a 2nd optical film bonding process is performed in a continuous manufacturing line.

(13) inspection process

Moreover, as a continuous process, it is preferable to have an inspection process (FIG. 4, S7) similarly to the case of the said normal cutting system.

(14) mounting process

In the inspection step, the good quality determined optical display unit A is mounted on the image display device. In the case of a defective product determination, a rework process is carried out, the optical film is newly adhered, and continuously inspected, and in the case of a good product determination, the process is carried out to a mounting process, and in the case of a defective product determination, the rework process is carried out again or discarded.

[Manufacturing System Suitable for Manufacturing Image Display Apparatus by Continuous Method]

The schematic structure of a manufacturing system is shown to FIG. 5A and 5B about an example of embodiment which implements the said Embodiment 1 (the manufacturing method including the cutting process by a skip cut system) below.

As shown to FIG. 5A and FIG. 5B, such a manufacturing system has a 1st manufacturing part which bonds a 1st optical film to an optical display unit, and a 2nd surface is different from the surface of the optical display unit with which the 1st optical film was bonded. It has a 2nd manufacturing part which bonds an optical film.

The 1st manufacturing part has the 1st mounting means which installs the 1st roll raw material of elongate 1st sheet product F1, the 1st conveying means which unwinds and conveys 1st sheet product F1 from 1st roll raw material, and has been conveyed First release film removing means for removing the first release film from the first sheet product, first defect inspection means for performing a defect inspection after removing the first release film, and second release film after the first defect inspection 1 After bonding the 2nd release film bonding means and the 2nd release film which bond together to a 1st optical film via an adhesive layer, the 1st optical film and a 1st adhesive layer are not cut, without cutting the said 2nd release film. Bonding the 1st cutting means which cut | disconnects to a predetermined | prescribed size, and the 1st optical film from which the said 2nd release film was removed, through the 1st adhesive layer, removing a 2nd release film after a 1st cutting process, to an optical display unit. 1st optical film bonding means to respectively, It has a first control means for controlling to interlock the means.

The 2nd manufacturing part has the 2nd installation means which installs the 2nd roll raw material of elongate 2nd sheet product F2, the 2nd conveying means which unwinds and conveys 2nd sheet product F2 from 2nd roll raw material, and has been conveyed The third release film removing means for removing the third release film from the second sheet product, the second defect inspection means for performing a defect inspection after the removal of the third release film, and the fourth release film after the second defect inspection After bonding the 4th release film bonding means and 4th release film which bond together to a 2nd optical film via 2 adhesive layers, the 2nd optical film and 2nd adhesive layer are not cut, 2nd cutting means which cut | disconnects to a predetermined | prescribed magnitude | size, and the 2nd optical film from which the said 4th release film was remove | eliminated through the 2nd adhesive layer, removing a 4th release film after a 2nd cutting process, 1 different from the side to which the optical film is bonded It has the 2nd optical film bonding means bonded to a surface, and the 2nd control means which controls so that each means may work together.

Although the 1st manufacturing part and the 2nd manufacturing part may drive independently, respectively, you may drive so that each may cooperate. The first control means and the second control means can be configured to drive control in conjunction with a series of processing steps. In addition, in the manufacturing method by the normal system which does not employ a skip cut like the said Embodiment 1, the structure in which a release film removal means, a fault inspection means, and a release film bonding means was abbreviate | omitted can be employ | adopted.

(First manufacturing department)

The 1st mounting means 301 is comprised by the roller mounting apparatus which interlocked with the motor etc. so that the 1st roll raw material of elongate 1st sheet product F1 may be installed and it may rotate at a free rotation or a fixed rotational speed. The rotational speed is set by the first control means 307 and drive controlled.

The first conveying means 302 releases the first sheet product F1 from the first roll raw material, and conveys the first sheet product F1 (or the first optical film) to each processing step. Tension controls are installed in the main parts of each process. The 1st conveyance means 302 is controlled by the 1st control means 307.

A 1st release film removal means is a structure which peels and removes a 1st release film from the 1st sheet product F1 conveyed, and winds up in roll shape. The winding speed to the roll is controlled by the first control means 307. As a peeling mechanism (refer FIG. 5A), the front-end | tip has a sharp knife edge, it wound up and conveyed a 1st release film to this knife edge, and peeled and removed the 1st release film, and peeled the 1st release film, It is comprised so that a later 1st sheet product F1 may be conveyed in a conveyance direction.

The 1st defect inspection means 303 performs a defect inspection after removing a 1st release film. The first defect inspection means 303 is a CCD camera or a CMOS camera, and the acquired image data is transmitted to the first control means 307. The first control means 307 analyzes the image data, detects a defect, and calculates the position coordinates. The position coordinate of this fault is provided to the skip cut by the 1st cutting means mentioned later.

A 2nd release film bonding means bonds a 2nd release film to a 1st optical film via a 1st adhesive layer after 1st defect inspection. As shown in Fig. 5A, the second release film is released from the roll raw material of the second release film, and the second release film and the first optical film are sandwiched between one or a plurality of roller pairs, and the roller pair Join by applying a predetermined pressure at. The rotational speed, pressure control, and conveyance control of the roller pair are controlled by the first control means 307.

After bonding the 2nd release film, the 1st cutting means 304 cut | disconnects a 1st optical film and a 1st adhesive layer to predetermined size, without cutting | disconnecting the said 2nd release film. The first cutting means 304 is a laser device. Based on the position coordinates of the defect detected in the first defect inspection process, the first cutting means 304 cuts to a predetermined size to avoid the defect portion. That is, the cut including the defective portion is excluded from the subsequent process as defective. Or the 1st cutting means 304 may cut | disconnect to predetermined size continuously, ignoring the presence of a fault. In this case, in the joining process mentioned later, it can be comprised so that a said part may be joined to a removal or temporary board unit, without joining. Control in this case also depends on the function of the first control means 307.

Moreover, the 1st cutting means 304 arrange | positions the holding table which adsorbs-holds 1st sheet product F1 from the back surface, and equips the laser apparatus above 1st sheet product F1. The first optical film, the first pressure sensitive adhesive layer, and the protective film are cut at a predetermined pitch in the conveyance direction while leaving the second release film at the bottom, leaving the second release film at the bottom in the width direction of the first sheet product F1 (hereinafter, Appropriately referred to as "half cut"). Moreover, this laser apparatus is made to collect from the width direction of the 1st sheet | seat product F1, the air nozzle which injects warm air toward a cut | disconnected part, and the gas (smoke) generated from the cut | disconnected site conveyed by this warm air. It is preferable to be integrally comprised in the state in which a dust collecting duct was opposed. In the case of adsorbing the first sheet product F1 on the holding table, the step rollers 302a and 302b of the conveying mechanism move in the vertical direction so as not to stop the continuous conveyance of the first sheet product F1 on the downstream side and the upstream side. It is configured to. This operation is also controlled by the first control means 307.

The 1st optical film bonding means bonds the 1st optical film from which the said 2nd release film was removed to the optical display unit W via the 1st adhesive layer, removing a 2nd release film after a 1st cutting process. As shown in FIG. 5B, in the case of bonding, the first optical film 1 is bonded to the optical display unit W surface by pressure roller 305. The pressurization pressure and the operation of the roller 305 are controlled by the first control means 307. As a peeling mechanism, the optical film conveyed with the 2nd release film 22 by having knife edge N1 with a sharp tip, and winding the 2nd release film 22 around this knife edge and conveying it in reverse (reverse conveyance) While peeling and removing a 2nd release film from (1), the front end conveys the 1st optical film 1 after peeling a 2nd release film to the center lower part of the pressure roller 305, and the optical display unit W surface It is configured to be sent to. At this time, the pressure roller is moved vertically downward after the second mold release film is removed from the state in which a tension of 150N / m or more and 1000N / m is applied to the second mold release film and / or the first optical film, and the optical film is optical The bonding precision of a 1st optical film and an optical display unit can be improved by performing time until it presses tightly to the display unit W surface and is crimped | bonded by predetermined pressure within 3 second. When the tension is smaller than 150 N / m, the feeding position of the first optical film is not stabilized, and when the tension is larger than 1000 N / m, the second release film is elongated and broken, or the optical characteristics may change. Moreover, when the time until pressure contact is longer than 3 second, the edge part of the 1st optical film peeled from the 2nd release film may bend, and a break and a bubble may generate | occur | produce. As a joining mechanism, it consists of the press roller 305 and the guide roller 3501 arrange | positioned facing it. The guide roller is constituted by a rubber roller driven by a motor, and a pressure roller 305 made of a metal roller driven by a motor is disposed above and directly above the pressure roller. When the optical roller is sent to the bonding position, the pressure roller 305 is raised to a position higher than the upper surface thereof so as to leave a roller gap. The guide roller 3501 and the pressure roller 305 may both be rubber rollers or metal rollers. The optical display unit W is washed in advance and stored. The adsorption conveying means 306 is arranged in the conveying mechanism. This control is also controlled by the first control means 307.

(Second manufacturing department)

In each process of a 2nd manufacturing part, 2nd mounting means 401, 2nd conveying means 402, 3rd release film removal means, 2nd fault inspection means 403, 4th release film bonding means, and 2nd Since the cutting means 404 is the same structure as the corresponding means of a 1st manufacturing part, description is abbreviate | omitted.

Optical display unit W1 manufactured by the 1st manufacturing part is conveyed to a 2nd manufacturing part. In the conveyance process or in a 2nd manufacturing part, the optical display unit W1 is inverted up and down. The vertical inverting means (not shown) is configured to adsorb and lift the optical display unit W1 from the upper surface by the adsorption means, to invert the upper and lower sides, and to place it in the transport mechanism again. This control is by the function of the second control means 407. Moreover, as another embodiment, the structure which does not perform an up-down inversion process is also possible. In this case, in a 2nd manufacturing part, each process is processed in the state which inverted 2nd sheet product F2 unlike normal (so that a release film might become an upper surface), and a 2nd optical film is bonded from the lower side of an optical display unit. It is configured to. In addition, when bonding a 2nd optical film with the said 1st optical film in 90 degree relationship (cross nicol relationship), a 2nd optical film is bonded after rotating the optical display unit W1 by 90 degrees.

The 1st control means 307 and the 2nd control means 407 control to interlock the said means of each process. Each operation timing is computed by arrange | positioning a sensor in a predetermined position, or making it detect a rotating member of a conveyance mechanism by a rotary encoder etc. The first and second control means 307 and 407 may be realized by a cooperative action between a software program and hardware resources such as a CPU and a memory. In this case, the program software, the processing procedure, the various settings, and the like may be implemented in advance. I remember it. Moreover, it can be comprised by dedicated circuits, firmware, etc.

In the said embodiment, although the sheet | seat product containing a fault part was bonded and collect | recovered to the temporary board unit, you may comprise so that it may be bonded to a strip | belt-shaped separator and wound up and collect | recovered.

The defect inspection can apply a well-known defect inspection method. Examples of the defect inspection method include visual inspection by an automatic inspection device and an inspector. The automatic inspection device is a device for automatically inspecting defects (also referred to as defects) of sheet-shaped products, and irradiates light, and acquires the reflected or transmitted images through an imaging unit such as a line sensor or a two-dimensional TV camera. Defect detection is performed based on the acquired image data. Image data is acquired in a state in which the inspection polarizing filter is interposed in the optical path between the light source and the image pickup unit. Usually, the polarization axis (for example, a polarization absorption axis) of this polarizing filter for inspection is arrange | positioned so that it may become a state (cross nicol) orthogonal to the polarization axis (for example, a polarization absorption axis) of the polarizing plate which is a test object. By arranging with cross nicol, for example, a black image of the entire surface is inputted from the image pickup unit if a defect does not exist, but if a defect exists, the portion does not become black (recognized as a bright point). Therefore, a defect can be detected by setting an appropriate threshold value. In such bright spot detection, defects such as surface deposits and foreign matter inside are detected as bright spots. In addition to this bright spot detection, there is also a method for detecting foreign matter by CCD imaging an image of a transmitted light on an object and analyzing the image. There is also a method of detecting foreign matter on the surface by CCD imaging the reflected light image with respect to the object and analyzing the image.

<Examples>

Although an Example is given to this invention below, this invention is not limited to the Example shown below. In addition, evaluation of the following Example, the reference example, and a comparative example is performed by the following method.

[How to measure]

(Peel strength)

The sample which cut out the sample to the rectangle of 15 mm of width | variety (TD) direction x 150 mm of length (MD) direction was used. The "machine" part of the state which peeled the polyester film and the polarizer was formed in the sample. This sample was affixed on a glass plate with a double-sided adhesive tape (No. 500 made by Nitto Denko), and the instrument part was chucked by a variable degree peel tester (made by Asahi Seko), and peeling angle: 90 degrees and peeling speed: Peeling strength (N / 15mm) between a polarizer and a polyester film was measured on 3000 mm / min conditions. In addition, the measurement was performed in the environment of the temperature of 23 degreeC.

(Appearance Inspection: Nick Defect)

The polarizing plate is cut out to have a rectangle of 500 mm in the TD direction × 2000 mm in the MD direction, and two sheets are laminated on a fluorescent lamp having a luminance of 8000 candela / m ² so that a commercially available iodine polarizing plate (trade name "SED1423DU" manufactured by Nitto Denko Co., Ltd.) is orthogonal to the transmission axis. The number of locations (nick defects) where light leaks out was counted by the naked eye.

(Curl amount of polarizing plate)

The sample which cut out the sample to A4 size (210 mm of TD direction x 297 mm of MD direction) was used. The measurement environment was set at a temperature of 23 ° C. and a humidity of 55% RH.

First, the sample was left standing for about 10 seconds on a horizontal stage to confirm the curved direction. After confirming the bending direction, the sample was allowed to stand for 10 minutes to be in a concave state (curved in the shape of a bowl when viewed from the side). Then, the height from the surface where the film was left to the upper end of the curved sample was visually measured using a straightener made of stainless steel (JIS class 1).

Tensile Modulus of Film

A sample piece having a width of 10 mm in the measuring direction (TD or MD) and having a sufficient length was cut out into a rectangle. That is, when measuring the elasticity modulus of MD direction, the sample piece of width 10mm in a TD direction and MD direction, for example, length 100mm is cut out, and when measuring elasticity of a TD direction, width 10mm in MD direction is measured. , TD, for example, cut out a sample piece of 100 mm in length. This sample was tension-tested by the tensile tester (tensilon) on 25 degreeC temperature conditions on the conditions of the tensile velocity of 50 mm / min, and the distance between chucks.

Draw a tangent where the strain-strength (SS) curve obtained by the tensile test initially rises, read the strength (tensile strength) at the position where the tangent extension becomes 100% elongation, and measure the cross-sectional area of the sample piece ( The value divided by thickness x sample width (10 mm) was taken as the tensile modulus of elasticity (commonly referred to as Young's modulus).

[Formation of easily bonding layer to polyester film]

(Production Example 1)

After corona treatment of the biaxially stretched polyethylene terephthalate film (T-100 made by Mitsubishi Chemical Co., Ltd.) having a thickness of 38 μm, the polyester-based water-dispersed urethane adhesive (Daiichi Kogyo Seyaku Co., Ltd., trade name `` Super Flex SF210 '') And coating using a coating tester equipped with a gravure roll of mesh # 200, and dried at 150 ° C. for 1 minute to form an easy adhesion layer having a thickness of 0.3 μm on the polyethylene terephthalate film.

(Production Example 2)

An oxazoline type crosslinking agent (made by Nippon Shokubai, brand name "WS-) with respect to 100 weight part of polyvinyl alcohol-type resins (average degree of polymerization 1200, saponification degree 98.5% mol%, acetoacetyl group modification degree 5 mol%) which have an acetoacetyl group. 700 '') was dissolved in pure water under conditions of a temperature of 30 ° C to prepare an aqueous solution prepared at a solid content concentration of 3.7% by weight. This aqueous solution was applied to a biaxially stretched polyethylene terephthalate film subjected to corona treatment in the same manner as in Production Example 1 using a wire bar (# 20), and dried at 130 ° C. for 5 minutes to form an easy adhesion layer having a thickness of 0.3 μm. Formed.

[Creator of polarizer]

(Production Example 3)

The polyvinyl alcohol film with an average polymerization degree of 2700 and a thickness of 75 µm was stretched and conveyed while dying between rolls having different circumferential speeds. First, after dipping for 1 minute in a 30 degreeC water bath and extending 1.2 times in a conveyance direction, swelling a polyvinyl alcohol film, it is immersed for 1 minute in 0.03 weight% of potassium iodide concentration of 30 degreeC, and 0.3 weight% of iodine concentration for 1 minute, It extended | stretched 3 times based on the film (original length) which is not extended | stretched at all in the conveyance direction, while dyeing. Next, it extended | stretched 6 times based on the original length in the conveyance direction, immersing for 30 second in the aqueous solution of 4 weight% of boric acid concentrations of 60 degreeC, and 5 weight% of potassium iodide concentrations. Next, the polarizer was obtained by drying the obtained stretched film at 70 degreeC for 2 minutes. Moreover, the thickness of the polarizer was 30 micrometers and the moisture content was 14.3 weight%.

[Production of Adhesive]

(Production Example 4)

To 100 parts by weight of polyvinyl alcohol-based resin having an acetoacetyl group (average degree of polymerization 1200, 98.5% mol% of saponification degree, 5 mol% of acetoacetyl group modification), 50 parts by weight of methylolmelamine was purified to pure water under a temperature condition of 30 ° C. It melt | dissolved and prepared the aqueous solution of 3.7 weight% of solid content concentration. To 100 parts by weight of this aqueous solution, 18 parts by weight of an aqueous solution containing an alumina colloid (average particle diameter 15 nm) having an electrostatic charge at a solid content concentration of 10% by weight was added to prepare a metal colloid-containing adhesive aqueous solution. The viscosity of the adhesive solution was 9.6 mPa · s, the pH was in the range of 4 to 4.5, and the compounding amount of the alumina colloid was 74 parts by weight based on 100 parts by weight of the polyvinyl alcohol resin.

In addition, the average particle diameter of an alumina colloid is measured by the dynamic light-scattering method (light correlation method) with a particle size distribution meter (The Nikki Chemical company, a product name "nanotrack UAP150").

(Production Example 5)

An aqueous adhesive solution containing no metal colloid was prepared in the same manner as in Production Example 4 except that 18 parts by weight of pure water was added instead of 18 parts by weight of the alumina colloidal aqueous solution.

[Creation of Transparent Protective Film]

(Production Example 6)

The lactone ring structure obtained by carrying out the cyclization condensation of the copolymer of methyl methacrylate (MMA) and methyl 2- (hydroxymethyl) acrylate (MHMA) similarly to Example 1 of Unexamined-Japanese-Patent No. 2000-23016. (Meth) acrylic resin pellets having This pellet was dissolved in methyl ethyl ketone, and a film was produced by the solution casting method. The 30-micrometer-thick lactone ring containing acrylic resin film was obtained by longitudinally uniaxially stretching this film at 1.5 degreeC at the speed | rate of 0.1 m / min at 100 degreeC.

[Creation of polarizing plate]

(Example 1)

On both main surfaces of the polarizer obtained in Production Example 3, an adhesive of Production Example 4 was applied to the easy adhesion layer formation surface of the polyester film having the adhesion layer obtained in Production Example 1 so that the adhesive layer thickness after drying was 80 nm. It bonded together using the roll machine, it dried at 70 degreeC for 6 minutes, and created the polarizing plate.

(Example 2)

In the said Example 1, the polarizing plate was created like Example 1 except having used the polyester film obtained by the manufacture example 2 instead of the polyester film obtained by the manufacture example 1.

(Reference Example 1)

In the said Example 1, the polarizing plate was created like Example 1 except having used the adhesive agent of manufacture example 5 instead of the adhesive agent of manufacture example 4.

(Reference Example 2)

In the said Example 2, the polarizing plate was produced like Example 2 except having used the adhesive agent of manufacture example 5 instead of the adhesive agent of manufacture example 4.

(Comparative Example 1)

In the said Example 1, the polarizing plate was produced like Example 1 except having used the polyester film in which the easily bonding layer was not formed instead of the polyester film obtained by the manufacture example 1.

(Comparative Example 2)

In Comparative Example 1, a polarizing plate was produced in the same manner as in Comparative Example 1 except that the adhesive of Preparation Example 5 was used instead of the adhesive of Preparation Example 4.

The structure of the polarizing plate obtained by the said Example, the reference example, and the comparative example, the peeling strength of a polyester film and a polarizer, and the result of an external appearance (nick) test are shown in Table 1.

In Examples 1 and 2 and the reference examples 1 and 2 in which a polyester film has an easily bonding layer, adhesive force was large and the film broke beyond the measurable limit (upper limit) of peeling strength.

As is evident from the above results, the polarizing plates of Examples 1 and 2 are excellent in the adhesion between the polarizer and the protective film, so that floating and peeling of the protective film are unlikely to occur. Moreover, since the adhesive agent containing a metal colloid was used for laminating | stacking a polarizer and a polyester film, compared with the reference examples 1 and 2 which used the adhesive agent which does not contain a metal colloid, the generation | occurrence | production of nick was few and the external appearance was also favorable.

(Example 3)

Adhesive layer thickness after drying the triaxial cellulose film (KC4UY by Konica Minolta) on the other main surface of the biaxially stretched polyester film which has the easily bonding layer obtained in manufacture example 1 on one main surface of the polarizer obtained by manufacture example 3, respectively. The adhesive agent of manufacture example 4 was apply | coated so that it might be set to 80 nm, it bonded together using the roll machine, it dried at 70 degreeC for 6 minutes, and created the polarizing plate. In addition, the arrangement | positioning of the biaxially stretched polyester film which has an easily bonding layer was laminated | stacked so that the easily bonding layer formation surface of a polyester film and a polarizer might oppose similarly to Example 1.

(Examples 4 to 10)

The polarizing plate was produced like Example 3 except having used the film shown in Table 2 instead of the triacetyl cellulose film (KC4UY by Konica Minolta) of Example 3.

(Example 11)

On one main surface of the polarizer obtained in Production Example 3, the one obtained by applying the adhesive of Production Example 4 to the adhesive layer forming surface of the polyester film having the easily bonding layer obtained in Production Example 1 so that the adhesive layer thickness after drying became 80 nm. It bonded together using the roll machine, it dried for 6 minutes at 70 degreeC, and created the polarizing plate of the state in which the transparent film is not laminated on the other main surface of the polarizer.

Table 2 shows the elasticity modulus of the transparent film used for the polarizing plates of Examples 1 and 3-11, each curling film, and the curl measurement result of a polarizing plate.

In Table 2, code | symbol "+" of a curl amount shows that the film curled so that the surface of the side which laminated | stacked the biaxially stretched polyester film might be inner side, and code | symbol "-" shows the surface of the side which laminated | stacked the biaxially stretched polyester film is outside It shows that a film curled so that it may become. In addition, MD and TD show what was curled in MD direction and TD direction, respectively.

In the polarizing plate of Example 3, since the film curled cylindrically in MD direction so that the surface of the side which laminated | stacked the biaxially stretched polyester film might become inner side, the amount of curl could not be measured. Moreover, it was 60 mm when the diameter of this cylinder was visually measured using the stainless steel straight ruler (JIS1 grade). In addition, the polarizing plate of Example 9 was also curled in a cylindrical shape having a diameter of 40 mm. In the polarizing plate of Example 11 in which the transparent film was not laminated | stacked on one main surface of the polarizing plate, the film curled cylindrically in the TD direction so that the surface of the side which laminated | stacked the biaxially stretched polyester film might be outer side. It was 38 mm when the diameter of this cylinder was measured similarly to the polarizing plate of Example 3.

As apparent from Table 2, in the polarizing plate of Example 1 which used the same polyester film on both surfaces corresponding to the structure of FIG. 1 (a) of this application, the curl did not generate | occur | produced, FIG. ) And curls were generated in the polarizing plates of Examples 3 to 11 corresponding to the configurations of (c). The curl amount of the said polarizing plate originates in the difference of the elasticity modulus of the film laminated | stacked on the polarizing plate from the tendency which the curl amount becomes large, so that the difference of the elasticity modulus of the polyester film laminated | stacked on one main surface of the polarizer and the transparent film laminated | stacked on the other main surface is large. It is estimated.

In this state of curling, it becomes difficult to handle the polarizing plate in sheets, but by applying the manufacturing method according to the continuous method of the present invention, an image display apparatus can be produced regardless of the occurrence of curling.

P: polarizer
E: polyester film
T: transparent film
H: easy adhesion layer
G: adhesive layer
A: optical display unit
W: optical display unit
1: first sheet product
2: second sheet product
11: first optical film
12: first release film
14: first pressure-sensitive adhesive layer
21: second optical film
22: second release film
24: second pressure sensitive adhesive layer

Claims (2)

It is a manufacturing method by the continuous system of the image display apparatus which bonds a polarizing plate to an optical display unit via an adhesive layer,
Roll raw material preparation process which prepares the long sheet of a polarizing plate and a release film as roll raw materials,
A cutting step of releasing the sheet product from the roll raw material and cutting the polarizing plate to a predetermined size using cutting means while preventing the release film from being cut;
After the said cutting process, it has a bonding process which bonds the said polarizing plate to an optical display unit via an adhesive layer, removing the said release film,
The polarizing plate is formed such that the polyester film E having an easy adhesion layer H formed on at least one main surface of one side of the polarizer P having a moisture content of 10 to 30% by weight is opposed to the easily bonding layer forming surface of the polyester film. It is laminated | stacked through the adhesive bond layer G, and the film is not laminated | stacked on the other main surface of the polarizer P, The manufacturing method by the continuous system of the image display apparatus characterized by the above-mentioned. The method of claim 1,
The adhesive layer G is a resin solution containing a polyvinyl alcohol-based resin, a crosslinking agent, and a metal compound colloid having an average particle diameter of 1 to 100 nm, and the metal compound colloid is 200 based on 100 parts by weight of the polyvinyl alcohol-based resin. The manufacturing method by the continuous system of the image display apparatus formed with the adhesive mix | blended in the ratio of a weight part or less.

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