JP6601523B2 - Method for producing polarizing laminated film having region not exhibiting polarizing ability and polarizing plate - Google Patents

Description

  The present invention relates to a method for producing a polarizing laminated film that does not exhibit polarizing ability and has a high transmittance region by dyeing after forming a stain-resistant layer on a polyvinyl alcohol-based resin layer. The present invention also relates to a polarizing plate produced from the polarizing laminated film obtained by this method and having a region that does not exhibit polarizing ability.

  A polarizing plate is widely used as a polarized light supplying element and a polarized light detecting element in a display device such as a liquid crystal display device. Conventionally, a polarizing film (polarizer layer) made of a polyvinyl alcohol-based resin and a protective film made of triacetyl cellulose are used as the polarizing plate.

  On the other hand, in recent years, with the development of liquid crystal display devices such as notebook personal computers and mobile devices such as mobile phones, the transmittance has been increased due to demands for diversification of display purposes, clarification of display categories, decoration, etc. There is a need to provide polarizing plates having different regions. In particular, in a small and medium-sized portable terminal represented by a smartphone or a tablet-type terminal, a polarizing plate may be bonded to the entire surface in order to have a seamless design from the viewpoint of decoration. In that case, since the polarizing plate overlaps the camera lens area and the icon and logo printing area at the bottom of the screen, there is a problem that the sensitivity of the camera is deteriorated and the design is inferior. Correspondence is made by drilling.

  Conventionally, a polarizing film is produced by stretching a film made of a polyvinyl alcohol resin alone or while stretching it to produce a polarizing film by dyeing or crosslinking, and laminating the film on a protective film or the like. However, it was only possible to reduce the thickness to the limit of the thickness of the polarizing film alone. For this reason, after providing a polyvinyl alcohol resin layer on the surface of the base film, the polyvinyl alcohol resin layer is stretched together with the base film, and the polyvinyl alcohol resin layer is polarized through a dyeing / crosslinking step and a subsequent drying step. By adopting a polarizer layer, a method has been proposed in which the total thickness of the base film and the polarizer layer can be reduced to the limit, and the thickness of the polarizer layer (polarizing film) can be made thinner than before. ing. For example, JP 2000-338329 A (Patent Document 1) discloses a method in which a polyvinyl alcohol-based resin layer is stretched and dyed together with the base film and dyed to make the polyvinyl alcohol-based resin layer a polarizer layer. JP 2012-159778 A (Patent Document 2) and the like.

  It is also known that a single polarizing plate is provided with regions having different transmittances, that is, regions having different polarization capabilities. For example, Japanese Patent Application Laid-Open No. 62-50802 (Patent Document 3) has modified dyeability. A polarizing film having regions having different transmissivities composed of a dyed stretched hydrophilic polymer film is disclosed. The hydrophilic polymer film here is typically a polyvinyl alcohol film. And it is supposed that the polarizing film which has the area | region where light transmittance differs will be obtained by changing a polyvinyl alcohol film by heat processing. However, when the polyvinyl alcohol film is heat-treated after stretching, there is a problem that the polyvinyl alcohol film shrinks due to heat. On the other hand, the method of stretching after the heat treatment or the method of stretching simultaneously with the heat treatment has a problem that the shape of the region modified by heating is deformed after stretching.

  In JP-A-62-96905 (Patent Document 4), a polyvinyl alcohol film is uniaxially stretched in a boric acid aqueous solution, and then a protective film is bonded to one side, and the protective film is not bonded. A method of dyeing after patterning a polyvinyl alcohol surface with a photoresist is disclosed. However, since polyvinyl alcohol after crosslinking is difficult to dye, a polarizing plate having high polarization ability cannot be produced by this method.

  Furthermore, a countermeasure is also taken by drilling the polarizing plate. An example of a perforated polarizing plate is shown in a schematic cross-sectional view in FIG. In the perforated polarizing plate 70, the protective film 41 is bonded to the polarizer layer 31 via the adhesive layer 61, and the surface of the polarizer layer 31 opposite to the protective film 41 is bonded to a liquid crystal cell or the like. The pressure-sensitive adhesive layer 62 is provided. And the hole 72 which penetrates from the protective film 41 to the adhesive layer 62 is provided, and this hole 72 becomes a transparent area | region, ie, the area | region which does not show polarization ability.

  In such a drilling process of a polarizing plate, in addition to the problem of poor production efficiency, a step is visually recognized on the polarizing plate, or cracks occur in the polarizer due to local stress during drilling process and durability test. Because of such problems, it was not satisfactory from the viewpoint of design and practicality.

JP 2000-338329 A JP 2012-159778 A Japanese Patent Laid-Open No. 62-50802 JP-A-62-96905

  The present inventor has found that if a certain method is employed, a polarizing plate having a region with high transmittance without being dyed with a dichroic dye can be efficiently produced. That is, the present invention aims to produce a polarizing laminate film useful for providing a polarizing plate having a region not dyed with a dichroic dye for providing a liquid crystal display device having excellent design properties. And Another object of the present invention is to provide a polarizing plate having a region having a high transmittance and a thin polarizer layer by bonding a protective film to the polarizing laminate film thus obtained.

  According to this invention, it is a manufacturing method of a light-polarizing laminated film provided with a base material film and the polarizer layer formed on the base material film, Comprising: A polyvinyl alcohol-type resin layer is formed in the surface of the said base film. A resin layer forming step for obtaining a laminated film, a stretching step for obtaining the laminated stretched film by stretching the obtained laminated film, and forming a dye-resisting layer on a part of the surface of the polyvinyl alcohol-based resin layer of the obtained laminated stretched film Contacting the laminated stretched film on which the above-mentioned dye-proof layer is formed with a dye solution containing an anti-dyeing step and a dichroic dye, the polyvinyl alcohol resin layer is dyed with the dichroic dye, and the polarizer layer is A method for producing a polarizing laminated film having a region that does not exhibit polarizing ability, comprising a dyeing step to be formed is provided.

  Moreover, said base film was removed from the light-polarizing laminated film obtained by said manufacturing method, the protective film was bonded to the at least one surface of the polarizer layer, and said dye-resistant layer was formed. There is also provided a polarizing plate in which the polyvinyl alcohol resin layer in the region does not exhibit polarizing ability, and the polarizer layer made of the polyvinyl alcohol resin dyed with the dichroic dye has a thickness of 10 μm or less.

  The polarizing laminated film produced by the method of the present invention has a region that does not exhibit polarizing ability, and the region that does not exhibit the polarizing ability remains in the same size as the portion on which the anti-stain layer is formed. The size of the region that does not show the polarization ability can be easily controlled. The polarizing plate obtained by laminating a protective film on the polarizer layer of the polarizing laminate film has a controlled size of a region that does not exhibit polarizing ability.

It is a flowchart which shows the outline | summary of the manufacturing method of the light-polarizing laminated film which concerns on this invention. It is a flowchart which shows an example of the preferable process until obtaining the polarizing plate which has the area | region which does not show polarization ability according to this invention with typical sectional drawing. It is sectional drawing which shows typically the state which formed the adhesive layer in the polarizing plate obtained in Example 1 mentioned later. It is sectional drawing which shows typically the state which formed the adhesive layer in the polarizing plate obtained in Example 2 mentioned later. It is sectional drawing which shows typically an example of the conventional perforated polarizing plate.

  In this specification, the manufacturing method of a light-polarizing laminated film and a polarizing plate, a light-polarizing laminated film, a polarizing plate, etc. are disclosed. In this specification, the laminated body provided with the polyvinyl alcohol-type resin layer on the surface of a base film is called "laminated film." For the “laminated film”, a laminate having a polyvinyl alcohol-based resin layer on one side of the base film is referred to as a “single-side coated film”, and a polyvinyl alcohol-based resin layer is provided on both sides of the base film. The laminate is sometimes referred to as “double-sided coated film”.

  Moreover, the polyvinyl alcohol-type resin layer which has a function as a polarizer is called "polarizer layer", and the laminated body of a base film and a polarizer layer is called "polarizing laminated film." For “polarizing laminate film”, a laminate having a polarizer layer on one side of a base film is referred to as a “single-sided polarizing laminate film”, and a laminate having a polarizer layer on both sides of the base film. The body is sometimes referred to as a “double-sided polarizing laminate film”. In addition, a laminate including a protective film on at least one surface of the polarizer layer is referred to as “polarizing plate”. First, each component of a light-polarizing laminated film and a polarizing plate will be described in detail.

[Base film]
As the resin constituting the base film, a thermoplastic resin excellent in transparency, mechanical strength, thermal stability, stretchability and the like is preferably used, and depending on its glass transition temperature (Tg) or melting point (Tm). An appropriate resin can be selected. Specific examples of thermoplastic resins include polyolefin resins, polyester resins, cyclic polyolefin resins (norbornene resins), (meth) acrylic resins, cellulose ester resins, polycarbonate resins, polyvinyl alcohol resins, vinyl acetate. Resin, polyarylate resin, polystyrene resin, polyethersulfone resin, polysulfone resin, polyamide resin, polyimide resin, mixtures thereof, and copolymers thereof.

  The base film may be a single layer using only one kind of the above-mentioned resin, or may be a blend of two or more kinds of resins. Of course, a multilayer film may be formed instead of a single layer.

  The polyolefin-based resin is a polymer having a chain olefin such as ethylene or propylene as a main monomer. Further, a propylene-ethylene copolymer obtained by copolymerizing propylene with ethylene can also be used. Copolymerization is possible with other types of monomers, and examples of other types of monomers copolymerizable with propylene include ethylene and α-olefins. The α-olefin copolymerized with propylene has 4 or more carbon atoms, and preferably an α-olefin having 4 to 10 carbon atoms. Specific examples of the α-olefin having 4 to 10 carbon atoms include linear monoolefins such as 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene and 1-decene; 3 -Branched monoolefins such as methyl-1-butene, 3-methyl-1-pentene, and 4-methyl-1-pentene; vinylcyclohexane and the like. The copolymer of propylene and another monomer copolymerizable therewith may be a random copolymer or a block copolymer. The content of the structural unit derived from the other monomer in the copolymer is determined by the infrared (IR) spectrum according to the method described on page 616 of “Polymer Analysis Handbook” (1995, published by Kinokuniya Shoten). It can be obtained by measurement. The polyolefin-based resin is preferably used as a base film in the present invention because it is easily stretched stably at a high magnification.

  Among polyolefin resins, propylene resins are preferred, and examples thereof include propylene homopolymer, propylene-ethylene random copolymer, propylene-1-butene random copolymer, and propylene-ethylene-1-butene random copolymer. Etc.

  The stereoregularity of the propylene-based resin is preferably substantially isotactic or syndiotactic. A film made of a propylene-based resin having substantially isotactic or syndiotactic stereoregularity has relatively good handleability and excellent mechanical strength in a high temperature environment.

  The polyester-based resin is a polymer having an ester bond, and specifically, is often composed of a polycondensate of a polyvalent carboxylic acid and a polyhydric alcohol. The polyvalent carboxylic acid used is mainly a divalent dicarboxylic acid or an ester thereof, and examples thereof include terephthalic acid, isophthalic acid, dimethyl terephthalate, and dimethyl naphthalenedicarboxylate. The polyhydric alcohol used is also mainly a divalent diol, and examples thereof include propanediol, butanediol, neopentyl glycol, and cyclohexanedimethanol.

  A typical example of the polyester resin is polyethylene terephthalate which is a polycondensate of terephthalic acid and ethylene glycol. Polyethylene terephthalate is a crystalline resin, but the one in a state before crystallization treatment is more easily subjected to treatment such as stretching. If necessary, it can be crystallized during stretching or by heat treatment after stretching. Further, a copolymerized polyester having a crystallinity lowered (or made amorphous) by further copolymerizing another monomer with a polyethylene terephthalate skeleton is also preferably used. Examples of such resins include those obtained by copolymerizing cyclohexanedimethanol and isophthalic acid. Since these resins are also excellent in stretchability, they can be suitably used.

  Specific polyester resins other than polyethylene terephthalate and copolymers thereof include polybutylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, polytrimethylene terephthalate, polytrimethylene naphthalate, polycyclohexane dimethyl terephthalate, polycyclohexane. Examples thereof include dimethyl naphthalate. These blend resins and copolymers can also be used.

  Cyclic polyolefin-based resin is a general term for polymers having cyclic olefin as a main constituent monomer, and is described in, for example, JP-A 1-240517, JP-A-3-14882, JP-A-3-122137, etc. There is resin that has been. Specific examples include ring-opening (co) polymers of cyclic olefins, addition polymers of cyclic olefins, copolymers of cyclic olefins and α-olefins such as ethylene or propylene (typically random copolymers). There are graft polymers obtained by modifying these with unsaturated carboxylic acids or derivatives thereof, and hydrides thereof. Specific examples of the cyclic olefin include norbornene monomers. As the cyclic polyolefin resin, a norbornene resin is particularly preferably used.

  Various products are commercially available as cyclic polyolefin resins. For example, “TOPAS” manufactured by TOPAS ADVANCED POLYMERS and sold in Japan by Polyplastics Co., Ltd., “Arton” sold by JSR Co., Ltd. and sold by Nippon Zeon Co., Ltd. “ZEONOR” and “ZEONEX”, “APEL” sold by Mitsui Chemicals, Inc., etc. (all are trade names).

The (meth) acrylic resin is a polymer having a compound having a (meth) acryloyl group as a main constituent monomer. For example, poly (meth) acrylic acid ester such as polymethyl methacrylate, methyl methacrylate- (meth) acrylic acid copolymer, methyl methacrylate- (meth) acrylic acid ester copolymer, methyl methacrylate-acrylic acid ester -(Meth) acrylic acid copolymer, methyl (meth) acrylate-styrene copolymer (such as what is called MS resin), copolymer of methyl methacrylate and a compound having an alicyclic hydrocarbon group (for example, Methyl methacrylate-cyclohexyl methacrylate copolymer, methyl methacrylate- (meth) acrylate norbornyl copolymer, etc.). Preferably, such poly (meth) acrylate include polymer mainly comprising C _1-6 alkyl esters of (meth) acrylic acid. More preferable examples of the (meth) acrylic resin include a methyl methacrylate-based resin containing methyl methacrylate as a main component (50 to 100% by weight, preferably 70 to 100% by weight).

The cellulose ester resin is an ester of cellulose and a fatty acid. Specific examples of the cellulose ester resin include cellulose triacetate, cellulose diacetate, cellulose tripropionate, and cellulose dipropionate.
Moreover, these copolymers and those in which a part of the hydroxyl group is modified with another substituent are also included. Among these, cellulose triacetate is particularly preferable. Many products of the cellulose triacetate film are commercially available, which is advantageous in terms of availability and cost.
Examples of commercially available cellulose triacetate films are “Fujitac TD80”, “Fujitac TD80UF”, “Fujitac TD80UZ” and “Fujitac TD40UZ” sold by Fuji Film Co., Ltd., Konica Minolta Advanced Layer Co., Ltd. There are “KC8UX2M”, “KC4UY”, “KC2UA”, etc. (all are trade names) on the market.

  The polycarbonate resin is a polymer having a carbonate bond (—O—CO—O—) in the main chain. It is a kind of engineering plastic and is a resin having high impact resistance, heat resistance and flame retardancy. Moreover, since it has high transparency, it is used suitably also for an optical use. For optical applications, resins called modified polycarbonates in which the polymer skeleton is modified in order to lower the photoelastic coefficient, copolymerized polycarbonates with improved wavelength dependence, and the like are commercially available and can be suitably used. Such polycarbonate resins are commercially available, for example, “Panlite” sold by Teijin Chemicals Ltd., “Iupilon” sold by Mitsubishi Engineering Plastics, Sumitomo Dow Ltd. "SD Polica" sold by the company, "Caliber" sold by Dow Chemical Company, etc. (both are trade names).

  The base film may be composed of the above thermoplastic resin to which any appropriate additive has been added. Examples of such additives include ultraviolet absorbers, antioxidants, lubricants, plasticizers, mold release agents, anti-coloring agents, flame retardants, nucleating agents, antistatic agents, pigments, and coloring agents. The proportion of the thermoplastic resin itself in the base film is preferably 50 to 100% by weight, more preferably 50 to 99% by weight, still more preferably 60 to 98% by weight, and particularly preferably 70 to 97% by weight. is there. If the ratio of the thermoplastic resin in the base film is less than 50% by weight, the high transparency inherent in the thermoplastic resin may not be sufficiently exhibited.

  The thickness of the base film can be determined as appropriate, but in general, from the viewpoint of workability such as strength and handleability, it is preferably 1 to 500 μm, more preferably 1 to 300 μm, especially 5 to 200 μm. Is more preferable. Furthermore, a base film having a thickness in the range of 5 to 150 μm is even more preferable.

  The base film may be subjected to corona treatment, plasma treatment, flame treatment, or the like on at least the surface on which the resin layer is formed in order to improve adhesion with the resin layer. In order to improve adhesion, a thin layer such as a primer layer or an adhesive layer may be formed on the surface of the base film on the side where the resin layer is formed. In addition, when an adhesive bond layer, a corona treatment layer, etc. are provided, a base film means the thing of the state which does not contain them.

[Primer layer]
A primer layer may be formed on the surface of the base film. The primer layer may be formed of a material that exhibits a certain degree of strong adhesion to both the base film and the polyvinyl alcohol-based resin layer. For example, a thermoplastic resin excellent in transparency, heat stability, stretchability, etc. is used.
Specific examples include acrylic resins and polyvinyl alcohol resins, but are not limited thereto.

  The resin forming the primer layer may be used in a state dissolved in a solvent. Depending on the solubility of the resin, aromatic hydrocarbons such as benzene, toluene and xylene, ketones such as acetone, methyl ethyl ketone and methyl isobutyl ketone, esters such as ethyl acetate and isobutyl acetate, chlorine such as methylene chloride, trichloroethylene and chloroform A general organic solvent such as fluorinated hydrocarbons, alcohols such as ethanol, 1-propanol, 2-propanol, and 1-butanol can be used. However, if the primer layer is formed from a solution containing an organic solvent, the base film may be dissolved. Therefore, it is preferable to select an appropriate solvent in consideration of the solubility of the base film. In consideration of the influence on the environment, the primer layer is preferably formed from a coating solution containing water as a solvent. Of these, polyvinyl alcohol resins having excellent adhesion are preferably used.

  Specifically, the polyvinyl alcohol-based resin used for the primer layer is polyvinyl alcohol and its derivatives. Polyvinyl alcohol derivatives include polyvinyl formal, polyvinyl acetal, etc., as well as polyvinyl alcohol, olefins such as ethylene and propylene, unsaturated carboxylic acids such as acrylic acid, methacrylic acid and crotonic acid, and alkyl esters of unsaturated carboxylic acids. And those modified with acrylamide or the like. Among the above-mentioned polyvinyl alcohol resins, it is preferable to use polyvinyl alcohol.

In order to increase the strength of the primer layer, a crosslinking agent may be added to the thermoplastic resin.
As the cross-linking agent to be added to the thermoplastic resin, known ones such as organic and inorganic can be used. What is necessary is just to select a more suitable thing suitably with respect to the thermoplastic resin to be used. For example, what is necessary is just to select suitably from an epoxy type crosslinking agent, an isocyanate type crosslinking agent, a dialdehyde type crosslinking agent, a metal type crosslinking agent, etc.

  As the epoxy-based crosslinking agent, either a one-component curable type or a two-component curable type can be used. Examples include ethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, glycerin di- or tri-glycidyl ether, 1,6-hexanediol diglycidyl ether, trimethylolpropane triglycidyl ether, diglycidyl aniline, diglycidyl amine and the like. Be

  Examples of the isocyanate-based crosslinking agent include tolylene diisocyanate, hydrogenated tolylene diisocyanate, trimethylolpropane-tolylene diisocyanate adduct, triphenylmethane triisocyanate, methylenebis (4-phenylmethane) triisocyanate, isophorone diisocyanate, and these Examples thereof include a ketoxime block product or a phenol block product.

  Examples of the dialdehyde-based crosslinking agent include glyoxal, malondialdehyde, succindialdehyde, glutardialdehyde, maleindialdehyde, phthaldialdehyde, and the like.

  Examples of the metal-based crosslinking agent include metal salts, metal oxides, metal hydroxides, organometallic compounds, and the like. The type of metal is not particularly limited and may be appropriately selected.

  As metal salts, metal oxides and metal hydroxides, for example, magnesium, calcium, aluminum, iron, nickel, zirconium, titanium, silicon, boron, zinc, copper, vanadium, chromium, tin, or more divalent atoms And metal salts having a valence, oxides thereof and hydroxides thereof.

  An organometallic compound is a compound having in its molecule at least one structure in which an organic group is bonded directly to a metal atom or an organic group is bonded through an oxygen atom, a nitrogen atom, or the like. Here, the organic group means a monovalent or polyvalent group containing at least a carbon element, and can be, for example, an alkyl group, an alkoxy group, an acyl group, or the like. Further, the bond does not mean only a covalent bond, but may be a coordinate bond by coordination of a chelate compound or the like.

  As a suitable example of the metal organic compound used as a crosslinking agent, an organic titanium compound, an organic zirconium compound, an organic aluminum compound, and an organic silicon compound are mentioned. These organometallic compounds may be used alone or in a suitable mixture of two or more.

  Specific examples of organic titanium compounds include: tetranormal butyl titanate, tetraisopropyl titanate, butyl titanate dimer, tetra (2-ethylhexyl) titanate, and titanium orthoesters such as tetramethyl titanate; titanium acetylacetonate, titanium tetraacetyl Titanium chelates such as acetonate, polytitanium acetylacetonate, titanium octylene glycolate, titanium lactate, titanium triethanolamate, and titanium ethyl acetoacetate; titanium acylates such as polyhydroxy titanium stearate.

  Specific examples of the organic zirconium compound include zirconium normal propionate, zirconium normal butyrate, zirconium tetraacetylacetonate, zirconium monoacetylacetonate, zirconium bisacetylacetonate, and zirconium acetylacetonate bisethylacetoacetate. .

  Specific examples of the organoaluminum compound include aluminum acetylacetonate and aluminum organic acid chelate.

  Specific examples of the organosilicon compound include compounds in which the ligands exemplified above for the organotitanium compound and the organozirconium compound are bonded to silicon.

  In addition to the low-molecular crosslinking agents described so far, polymeric crosslinking agents such as methylolated melamine resins and polyamide epoxy resins can also be used. Commercially available polyamide epoxy resins include “Smiles Resin 650 (30)” and “Smiles Resin 675” (both trade names) sold by Taoka Chemical Co., Ltd.

  When a polyvinyl alcohol-based resin is used as the thermoplastic resin for forming the primer layer, polyamide epoxy resin, methylolated melamine, dialdehyde, metal chelate crosslinking agent and the like are preferably used as the crosslinking agent.

  The ratio of the thermoplastic resin and the crosslinking agent used to form the primer layer ranges from about 0.1 to 100 parts by weight of the crosslinking agent to 100 parts by weight of the resin. It may be determined as appropriate, and is particularly preferably selected from the range of about 0.1 to 50 parts by weight. The primer layer coating liquid preferably has a solid content concentration of about 1 to 25% by weight.

  The primer layer preferably has a thickness in the range of about 0.05 to 1 μm. More preferably, the thickness is 0.1 to 0.4 μm. If the primer layer is too thin, the adhesion between the base film and the polyvinyl alcohol resin layer is reduced. On the other hand, if the primer layer is too thick, the polarizing plate itself becomes thick, which is not preferable.

  In forming the primer layer, the coating method to be used is not particularly limited, and a wire bar coating method, a roll coating method such as reverse coating or gravure coating, a die coating method, a comma coating method, a lip coating method, or a spin coating method. And a known method such as a screen coating method, a fountain coating method, a dipping method, or a spray method.

[Polarizer]
Specifically, the polarizer layer is obtained by dyeing a uniaxially stretched polyvinyl alcohol resin layer with a dichroic dye and adsorbing and orienting the dichroic dye. As the polyvinyl alcohol resin, a saponified polyvinyl acetate resin can be used. Examples of the polyvinyl acetate resin include polyvinyl acetate, which is a homopolymer of vinyl acetate, and copolymers with other monomers copolymerizable with vinyl acetate. Examples of other monomers copolymerizable with vinyl acetate include unsaturated carboxylic acids, olefins, vinyl ethers, unsaturated sulfonic acids, and acrylamides having an ammonium group.

  What formed such a polyvinyl alcohol-type resin into a film comprises the polarizer layer which concerns on this invention. The method for forming the polyvinyl alcohol-based resin is not particularly limited, and can be formed by a known method, but from the viewpoint that a polarizer layer having a desired thickness can be easily obtained. The method of apply | coating this solution on the base film mentioned above, and forming into a film is preferable.

  The polarizer layer needs to be stretched and oriented, and is preferably formed by stretching at a stretch ratio of more than 5 times, more preferably more than 5 times and not more than 17 times.

  In the polarizer layer, the dichroic dye is adsorbed and oriented on the stretched and oriented polyvinyl alcohol resin as described above. The thickness of the polarizer layer is 10 μm or less, preferably 7 μm or less. By setting the thickness of the polarizer layer to 10 μm or less, a thin polarizing laminated film can be formed.

  The polyvinyl alcohol resin used for the polarizer layer preferably has a saponification degree of 80 mol% or more, more preferably 90 mol% or more, and particularly 94 mol% or more. If the degree of saponification is too low, the water resistance and heat-and-moisture resistance after making the polarizing plate may not be sufficient. Also, it may be a completely saponified product (having a saponification degree of 100 mol%), but if the saponification degree is too high, the dyeing speed becomes slow, and the production time is required to give sufficient polarization performance. In some cases, the polarizer may become long or a polarizer having sufficient polarization performance may not be obtained. Therefore, the saponification degree is preferably 99.5 mol% or less, more preferably 99 mol% or less, or 99.0 mol% or less.

The degree of saponification referred to here is the unit ratio (moles) of the ratio of acetate groups (acetoxy groups: —OCOCH ₃ ) contained in polyvinyl acetate resin, which is a raw material for polyvinyl alcohol resins, to hydroxyl groups by saponification treatment. %) And is defined by the following formula;
Saponification degree (mol%) = [(number of hydroxyl groups) ÷ (number of hydroxyl groups + number of acetate groups)] × 100.

  The higher the degree of saponification, the higher the proportion of hydroxyl groups, and hence the lower the proportion of acetate groups that inhibit crystallization. The saponification degree can be determined by a method defined in JIS K6726-1994 “Testing method for polyvinyl alcohol”.

  Further, the polyvinyl alcohol resin used in the present invention may be a modified polyvinyl alcohol partially modified. For example, polyvinyl alcohol resin modified with olefins such as ethylene or propylene, modified with unsaturated carboxylic acids such as acrylic acid, methacrylic acid or crotonic acid, modified with alkyl ester of unsaturated carboxylic acid And those modified with acrylamide. The proportion of modification is preferably less than 30 mol%, and more preferably less than 10 mol%. When modification exceeding 30 mol% is performed, it becomes difficult to adsorb the dichroic dye, resulting in a problem that the polarization performance is lowered.

  The average degree of polymerization of the polyvinyl alcohol-based resin is usually in the range of about 100 to 10000, preferably 1500 to 8000, and more preferably 2000 to 5000. The average degree of polymerization here can also be determined by the method defined in JIS K6726-1994 “Testing method for polyvinyl alcohol”.

  As polyvinyl alcohol resins having such characteristics, “PVA124” (saponification degree: 98.0-99.0 mol%) and “PVA117” (saponification degree: 98.0) sold by Kuraray Co., Ltd. 99.0 mol%), "PVA624" (saponification degree 95.0-96.0 mol%) and "PVA617" (saponification degree 94.5-95.5 mol%); Nippon Synthetic Chemical Industry Co., Ltd. "AH-26" (degree of saponification 97.0-98.8 mol%), "AH-22" (degree of saponification 97.5-98.5 mol%), "NH-18" (Saponification degree 98.0-99.0 mol%) and "N-300" (saponification degree 98.0-99.0 mol%); "JC" sold by Nippon Vinegar Poval Co., Ltd. -33 "(saponification degree 99.0 mol% or more)," JM-33 "(saponification degree 93.5-95.5 mol%) "JM-26" (degree of saponification 95.5-97.5 mol%), "JP-45" (degree of saponification 86.5-89.5 mol%), "JF-17" (degree of saponification) 98.0-99.0 mol%), "JF-17L" (degree of saponification 98.0-99.0 mol%) and "JF-20" (degree of saponification 98.0-99.0 mol%) (All are trade names), and these can be suitably used in the present invention.

  Specific examples of the dichroic dye used for dyeing the polyvinyl alcohol-based resin layer include iodine and dichroic organic dyes. As the dichroic organic dye, for example, Red BR, Red LR, Red R, Pink LB, Rubin BL, Bordeaux GS, Sky Blue LG, Lemon Yellow, Blue BR, Blue 2R, Navy RY, Green LG, Violet LB, Violet B, Black H, Black B, Black GSP, Yellow 3G, Yellow R, Orange LR, Orange 3R, Scarlet GL, Scarlet KGL, Congo Red, Brilliant Violet BK, Spura Blue G, Spura Blue GL, Spura Orange GL, Direct There are Sky Blue, Direct First Orange S and First Black. These dyes are commercially available. Only one type of dichroic dye may be used, or two or more types may be used in combination.

[Protective film]
The protective film may be a simple protective film having no optical function, or may be a protective film having an optical function such as a retardation film or a brightness enhancement film. The material constituting the protective film is not particularly limited. For example, a cyclic polyolefin resin, a cellulose acetate resin such as triacetyl cellulose and diacetyl cellulose, a polyester resin such as polyethylene terephthalate, polyethylene naphthalate, and polybutylene terephthalate, and a polycarbonate resin. Materials that have been widely used in the art such as resins, acrylic resins, and polypropylene resins can be used.

  As the cyclic polyolefin resin, commercially available products such as “TOPAS” manufactured by TOPAS ADVANCED POLYMERS and sold in Japan by Polyplastics Co., Ltd., “Arton” sold by JSR Co., Japan “Zeonor” (ZEONOR) and “ZEONEX” sold by ZEON Co., Ltd., “APEL” sold by Mitsui Chemicals, Inc. (all trade names) can be suitably used. . In order to form such a cyclic polyolefin-based resin into a film, a known method such as a solvent casting method or a melt extrusion method is appropriately used. In addition, “ESCINA retardation film” sold by Sekisui Chemical Co., Ltd., “ZEONOR FILM” sold by Nippon Zeon Co., Ltd. Furthermore, you may use the commercial item of the cyclic polyolefin resin film to which the phase difference was provided.

  The cyclic polyolefin resin film may be uniaxially stretched or biaxially stretched. An arbitrary retardation value can be imparted to the cyclic polyolefin-based resin film by stretching. Stretching is normally performed continuously while unwinding the film roll, and is stretched in the heating furnace in the roll traveling direction, in the direction orthogonal to the traveling direction, or both. The temperature of the heating furnace is usually in the range from the vicinity of the glass transition temperature of the cyclic polyolefin resin to the glass transition temperature + 100 ° C. The draw ratio is usually 1.1 to 6 times, preferably 1.1 to 3.5 times in one direction.

  Since the cyclic polyolefin resin film generally has poor surface activity, surface treatment such as plasma treatment, corona treatment, ultraviolet irradiation treatment, flame (flame) treatment, and saponification treatment is performed on the surface to be bonded to the polarizer layer. Is preferred. Among these, plasma treatment and corona treatment that can be performed relatively easily are preferable.

  Examples of the cellulose acetate-based resin film include commercially available products such as “Fujitack TD80”, “Fujitack TD80UF”, “Fujitack TD80UZ”, “Fujitack TD40UZ”, and Konica Minolta Advanced Layer (available from Fuji Film Co., Ltd.). “KC8UX2M”, “KC4UY”, “KC2UA”, etc. (all are trade names) sold by the company) can be suitably used.

  A liquid crystal layer or the like may be formed on the surface of the cellulose acetate-based resin film in order to improve viewing angle characteristics. Moreover, in order to provide a phase difference, the stretched cellulose acetate type-resin film can also be used. The cellulose acetate-based resin film is usually subjected to a saponification treatment in order to improve the adhesion with the polarizer layer. The saponification treatment is performed by immersing the film in an aqueous solution of an alkali such as sodium hydroxide or potassium hydroxide.

  An optical layer such as a hard coat layer, an antiglare layer and an antireflection layer can be formed on the surface of the protective film as described above. The method for forming these optical layers on the surface of the protective film is not particularly limited, and a known method can be used.

  The thickness of the protective film is preferably as thin as possible from the viewpoint of thinning, and is preferably 90 μm or less, and more preferably 50 μm or less. On the other hand, if the thickness is too thin, the strength may decrease and workability may be hindered.

[Method for producing polarizing laminated film]
Next, the manufacturing method of the light-polarizing laminated film which concerns on this invention is demonstrated. FIG. 1 is a flowchart showing an outline of this method, and FIG. 2 is a flowchart showing a schematic cross-sectional view of an example of a preferable process until obtaining a polarizing plate having a region not exhibiting polarization ability according to the present invention. is there. Among these, the manufacturing method of the light-polarizing laminated film of the present invention includes a resin layer forming step (S10) in which a polyvinyl alcohol-based resin layer is formed on the base film to obtain a laminated film, and the resulting laminated film is stretched and laminated. Stretching step for obtaining a stretched film (S20), dyeing step (S30) for forming a stain-proof layer on part of the surface of the polyvinyl alcohol-based resin layer in the resulting laminated stretched film, and dyeing containing a dichroic dye There is provided a dyeing step (S40) in which the laminated stretched film on which the above-mentioned dye-proof layer is formed is brought into contact with the solution, and the polyvinyl alcohol-based resin layer is dyed with a dichroic dye. After the dyeing step (S40), if necessary, a stain-proof layer removing step (S45) for removing the top stain-resistant layer is performed. Furthermore, usually, a polarizer layer is formed through a crosslinking step (S50) for performing a crosslinking treatment.

  Furthermore, in order to produce a polarizing plate etc., a double-sided coating film is wash | cleaned, the cleaning process (S60) which dries, a protective film is bonded on both surfaces or one side of a double-sided coating film, From the protective film bonding step (S70) for obtaining a single-sided bonding film, the drying step (S60) for drying the double-sided bonding film or the single-sided bonding film, and the double-sided bonding film or the single-sided bonding film, the base film is obtained. The peeling process (S80) which peels and obtains a polarizing plate is implemented in this order.

  Since the polyvinyl alcohol-type resin used as a polarizer layer is dye | stained only from the surface opposite to a base film, the anti-dyeing process becomes effective in the manufacturing method of the light-polarizing laminated film of this invention. Such a production method can produce a polarizing plate that does not partially exhibit polarizing ability.

  Hereinafter, based on FIG.1 and FIG.2, each process of S10-S80 is demonstrated in detail. In addition, in FIG. 2, although the example in the case of forming the polyvinyl alcohol-type resin layers 11 and 12 on both surfaces of the base film 1 is shown, a polyvinyl alcohol-type resin layer is formed only on one side of the base film 1, It is of course possible to make it a polarizer layer according to the invention. In the latter case, the steps after the stretching step (S20) shown in FIG. 1 may be sequentially performed on the state of the single-side coated film 16 in FIG.

<Resin layer forming step (S10)>
In the resin layer forming step (S10), the base film 1 is formed by forming polyvinyl alcohol resin layers (first polyvinyl alcohol resin layer 11 and second polyvinyl alcohol resin layer 12) on both surfaces of the base film 1. And the double-sided coating film 17 which consists of the polyvinyl alcohol-type resin layers 11 and 12 is obtained.

  Materials suitable for the base film 1 are as described in the description of the configuration of the polarizing laminated film. In addition, it is preferable to use the base film 1 that can be stretched in a temperature range suitable for stretching the polyvinyl alcohol-based resin. It is preferable that the material which comprises the two polyvinyl alcohol-type resin layers 11 and 12 formed in both surfaces of the base film 1 is the same material. By using the same material, it becomes easy to adjust the polarization performance of the polarizer layer formed therefrom.

  Moreover, it is preferable that the polyvinyl alcohol-type resin layers 11 and 12 in both surfaces of the double-sided coating film after extending | stretching are comparable thickness. The specific thickness of the polyvinyl alcohol resin layers 11 and 12 formed in the resin layer forming step (S10) is preferably more than 3 μm and not more than 30 μm, and more preferably 5 to 20 μm. If the initial thickness of the resin layer is 3 μm or less, it is not preferable because it becomes too thin after stretching and the dyeability is significantly deteriorated. On the other hand, if the thickness exceeds 30 μm, the thickness of the finally obtained polarizer layer may exceed 10 μm, which is also not preferable.

  The polyvinyl alcohol resin layers 11 and 12 are preferably formed by coating a polyvinyl alcohol resin solution obtained by dissolving polyvinyl alcohol resin powder in a good solvent on one surface of the base film 1 and removing the solvent. It is formed by evaporating and drying. By forming the polyvinyl alcohol resin layers 11 and 12 in this way, the polyvinyl alcohol resin layer can be made thin. To coat the polyvinyl alcohol resin solution on the base film, wire bar coating method, roll coating method such as reverse coating and gravure coating, die coating method, comma coating method, lip coating method, spin coating method, screen coating A known method such as a method, a fountain coating method, a dipping method, or a spray method can be appropriately selected and applied. A drying temperature is 50-200 degreeC, for example, Preferably it is 60-150 degreeC. The drying time is, for example, 2 to 20 minutes.

  The application of the polyvinyl alcohol-based resin layer to both surfaces of the base film 1 can be performed one side at a time using the above method, or using a dipping method, a spray coating method, or other special equipment, A polyvinyl alcohol-based resin solution can be simultaneously applied to both surfaces of the base film.

  In addition, a primer layer may be provided between the base film 1 and the polyvinyl alcohol resin layers 11 and 12 in order to improve the adhesion between the base film 1 and the polyvinyl alcohol resin layers 11 and 12. The primer layer is preferably formed from a composition containing a polyvinyl alcohol-based resin and a crosslinking agent from the viewpoint of adhesion. Materials suitable for the primer layer are as described in the description of the configuration of the polarizing plate.

  When providing a primer layer, the order of application to the base film 1 is not particularly limited. After forming the primer layer on both sides of the base film 1, the polyvinyl alcohol resin layers 11 and 12 are further provided on both sides. The primer layer and the polyvinyl alcohol-based resin layer 11 are sequentially formed on one surface of the base film 1 to form the single-side coated film 16, and then the primer is formed on the other surface of the base film. The layer and the polyvinyl alcohol-based resin layer 12 may be formed in this order.

<Extension process (S20)>
In the stretching step (S20), the double-sided coating film 17 obtained in the resin layer forming step (S10) is stretched, and the first polyvinyl alcohol-based resin layer 11 and the second polyvinyl alcohol-based resin layer 12 in the double-sided coating film 17 are stretched. The first stretched polyvinyl alcohol resin layer 21 and the second centrifuged polyvinyl alcohol resin layer 22 are used respectively. Preferably, uniaxial stretching is performed so that the stretching ratio is more than 5 times and not more than 17 times. A more preferable uniaxial stretching ratio is more than 5 times and not more than 8 times. When the draw ratio is 5 times or less, the polyvinyl alcohol-based resin layer is not sufficiently oriented, and as a result, the degree of polarization of the polarizer layer may not be sufficiently high. On the other hand, when the draw ratio exceeds 17 times, the laminated film is easily broken during stretching, and the thickness of the laminated film after stretching becomes unnecessarily thin, thereby reducing workability and handling properties in the subsequent process. There is a fear.

The stretching process in the stretching step (S20) may be performed in one stage or in multiple stages.
When extending | stretching by multistage, although the extending | stretching process after the 2nd stage may be performed in an extending process (S20), you may perform simultaneously with a dyeing process (S40) and a bridge | crosslinking process (S50). Thus, when extending | stretching in multiple steps, extending | stretching is performed so that it may become a draw ratio exceeding 5 times combining all the steps of an extending | stretching process.

<Dye-proofing process (S30)>
In the anti-dyeing step (S30), the anti-dyeing layer 35 is formed on a part of the surface of the stretched polyvinyl alcohol-based resin layer 21 of the laminated stretched film 26 obtained in the stretching step (S20). The anti-dyeing agent for forming the anti-dyeing layer 35 may be any one that does not dye the dichroic dye, so that the polyvinyl alcohol resin or urethane having a high modification rate that is difficult to adsorb the dichroic dye described above. Resin, acrylic resin, ultraviolet curable resin, paraffin, photoresist, etc. can be used. The dye-resistant layer 35 may be formed by printing a pattern or characters using a printing ink. Known offset printing, gravure printing, inkjet printing, or the like can be applied to the formation of the dye-proof layer 35, and it may be appropriately selected according to the shape.

<Dyeing process (S40)>
In the dyeing step (S40), the stretched polyvinyl alcohol-based resin layers 21 and 22 on both surfaces of the laminated stretched film 26 are dyed with a dichroic dye. The dichroic dye is as described above.

  The dyeing step (S40) is performed, for example, by immersing the entire laminated stretched film 26 in a solution (dyeing solution) containing the dichroic dye. As the staining solution, a solution in which a dichroic dye is dissolved in a solvent can be used. As a solvent for the dyeing solution, water is generally used, but an organic solvent compatible with water may be further added. The concentration of the dichroic dye in the dyeing solution is preferably 0.01 to 10% by weight, more preferably 0.02 to 7% by weight, and particularly preferably 0.025 to 5% by weight.

  When iodine is used as the dichroic dye, it is preferable to add an iodide to the dyeing solution because the dyeing efficiency can be further improved. Examples of the iodide include potassium iodide, lithium iodide, sodium iodide, zinc iodide, aluminum iodide, lead iodide, copper iodide, barium iodide, calcium iodide, tin iodide, and iodide. Examples include titanium. The addition ratio of these iodides is preferably 0.01 to 20% by weight in the dyeing solution. Of the iodides, potassium iodide is preferably used. When potassium iodide is added, the ratio of iodine to potassium iodide is preferably in the range of 1: 5 to 1: 100 by weight, more preferably 1: 6 to 1:80, especially 1: 7 to More preferably, it is in the range of 1:70.

  The immersion time of the laminated stretched film 26 in the dyeing solution is not particularly limited, but is usually preferably in the range of 15 seconds to 15 minutes, more preferably 1 minute to 3 minutes. The temperature of the dyeing solution is preferably in the range of 10 to 60 ° C, more preferably in the range of 20 to 40 ° C.

  It is possible to perform the dyeing process before the stretching process or simultaneously with the stretching process. However, the unstretched film is stretched so that the dichroic dye adsorbed on the polyvinyl alcohol resin can be favorably oriented. It is preferable to carry out a dyeing treatment after applying. At this time, it may be simply dyed what has been stretched in advance at the target magnification, or may be stretched again during dyeing and stretched at a low magnification in advance to reach the target magnification in total. . Further, in the case of stretching during the subsequent crosslinking treatment, the total draw ratio at the stage where the dyeing process is completed can be set lower than the target final magnification. In this case, what is necessary is just to adjust suitably so that the target magnification may be reached after a crosslinking process. However, in the present invention, since the shape and size of the region 36 that does not exhibit polarization ability are important, the portion of the stretched polyvinyl alcohol-based resin layer 21 where the dye-proof layer 35 is formed is left in the polarizer layer 31 as it is. It is preferable that the region 36 does not exhibit polarization ability. For this purpose, the shape of the stretched polyvinyl alcohol-based resin layer 21 is not substantially changed after the dyeing step (S40), specifically, the stretching treatment is performed only in the stretching step (S40). It is preferable not to extend substantially in the dyeing step (S40) or to minimize the extension in the dyeing step (S40).

<Dye-proof layer removing step (S45)>
If necessary, a stain-proof layer removal step (S45) is provided, and the stain-proof layer 35 can be washed and removed there. The anti-dyeing layer removing step (S45) may be before or after the cross-linking step (S50) described later, but if the anti-dyeing layer 35 is removed before the cross-linking step (S50), the polyvinyl in the undyed region 36 is obtained. Since alcohol can also be cross-linked, it is preferable in terms of durability.

<Crosslinking step (S50)>
After the dyeing step (S40), a cross-linking step (S50) for performing a cross-linking treatment is usually provided. The crosslinking treatment is performed, for example, by immersing the dyed laminated stretched film 26 in a solution containing a crosslinking agent (crosslinking solution). Conventionally known substances can be used as the crosslinking agent. Examples thereof include boron compounds such as boric acid and borax, glyoxal, glutaraldehyde and the like. These may use only 1 type and may use 2 or more types together.

  As the crosslinking solution, a solution in which a crosslinking agent is dissolved in a solvent can be used. As the solvent, for example, water can be used, but an organic solvent compatible with water may be further included. The concentration of the crosslinking agent in the crosslinking solution is not particularly limited, but is preferably in the range of 1 to 20% by weight, and more preferably 6 to 15% by weight.

  Iodide may be added to the crosslinking solution. By adding iodide, the in-plane polarization characteristics of the resin layer can be made more uniform. Examples of the iodide include potassium iodide, lithium iodide, sodium iodide, zinc iodide, aluminum iodide, lead iodide, copper iodide, barium iodide, calcium iodide, tin iodide, and titanium iodide. Etc. The content of iodide in the crosslinking solution is preferably 0.05 to 15% by weight, more preferably 0.5 to 8% by weight.

  The immersion time of the laminated stretched film in the crosslinking solution is usually preferably from 15 seconds to 20 minutes, and more preferably from 30 seconds to 15 minutes.

  In addition, a crosslinking process can also be performed simultaneously with a dyeing | staining process by mix | blending a crosslinking agent in a dyeing | staining solution. Moreover, what was previously extended | stretched by the target magnification may just be immersed in a crosslinking solution, and may be made to bridge | crosslink, and a crosslinking process and an extending | stretching process may be performed simultaneously. The laminated stretched film previously stretched at a low magnification in the stretching step may be stretched again during the crosslinking treatment to reach the target magnification in total. However, in the present invention, as described in the previous dyeing step (S40), since the shape and size of the region 36 that does not exhibit polarization ability are important, the stretching treatment is actually performed only in the stretching step (S40). It is preferable that the film is not substantially stretched even in the crosslinking step (S50), or that the stretching in the crosslinking step (S50) is minimized.

By reducing the above dyeing step (S40) and cross-linking step (S50), the stretched polyvinyl alcohol-based resin layers 21 and 22 have functions as the polarizer layers 31 and 32.
At this time, the portion of the stretched polyvinyl alcohol-based resin layer 21 covered with the dye-proof layer 35 formed in the dye-proofing step (S30) is not dyed with the dichroic dye, and thus has high transmittance and exhibits polarizing ability. Thus, a double-sided polarizing laminate film 38 having such a region 36 is obtained.

<Washing process (S60)>
After the dyeing step (S40) or when the crosslinking step (S50) is performed, it is preferable to provide a cleaning step (S60) for cleaning the double-sided polarizing laminated film 38 thereafter. In the cleaning step (S60), a water cleaning process can be employed. The water washing treatment can be performed, for example, by a method of immersing a stretched film in pure water such as ion exchange water or distilled water as a washing liquid. The temperature of water washing is usually 3 to 50 ° C, preferably 4 to 20 ° C.

The washing step (S60) may be a combination of a washing treatment with an iodide solution and a washing treatment with water, and appropriately using a solution containing a liquid alcohol such as methanol, ethanol, isopropyl alcohol, butanol, or propanol as the washing liquid. You can also.
Moreover, you may provide the process of draining using a nip roll, an air knife, etc. after the washing | cleaning process.

  In the washing step (S60), the immersion time of the double-sided polarizing laminated film 38 in the washing liquid is usually 2 to 300 seconds, preferably 3 to 240 seconds.

It is preferable to dry the double-sided polarizing laminated film 38 after the washing step (S60).
Arbitrary appropriate methods (for example, natural drying, ventilation drying, heat drying, etc.) are employable for drying. For example, the drying temperature in the case of heat drying is usually 20 to 95 ° C., and the drying time is usually about 1 to 15 minutes.

<Protective film bonding step (S70)>
In the protective film bonding step (S70), the protective film is applied to one or both surfaces of the double-sided polarizing laminate film 38 obtained through the above steps, that is, the surface of one polarizer layer or the surface of both polarizer layers. Paste. In FIG. 2, the method of bonding the protective films 41 and 42 to the surface of both the polarizer layers 31 and 32 is typically shown. For the bonding of the polarizer layer and the protective film, a method of bonding both through an adhesive layer or an adhesive layer can be employed. Materials suitable as the protective film are as described in the configuration of the polarizing plate.

(Adhesive layer)
The pressure-sensitive adhesive constituting the pressure-sensitive adhesive layer is usually a composition in which an acrylic resin, a styrene resin, a silicone resin, or the like is used as a base polymer and a crosslinking agent such as an isocyanate compound, an epoxy compound, or an aziridine compound is added thereto. Become. Furthermore, a pressure-sensitive adhesive layer exhibiting light scattering properties can be formed by mixing fine particles in the pressure-sensitive adhesive.

  The thickness of the pressure-sensitive adhesive layer is preferably 1 to 40 μm, but it is preferably applied thinly, and more preferably 3 to 25 μm, as long as the properties such as processability and durability are not impaired. If the thickness of the pressure-sensitive adhesive layer is in the range of 3 to 25 μm, it is suitable for showing good processability and suppressing the dimensional change of the polarizer layer. When the thickness of the pressure-sensitive adhesive layer is less than 1 μm, the adhesiveness is lowered, and when the thickness exceeds 40 μm, problems such as the pressure-sensitive adhesive protruding easily occur.

  The method for forming the pressure-sensitive adhesive layer on the protective film or the polarizer layer is not particularly limited, and a pressure-sensitive adhesive solution containing each component including the above-mentioned base polymer is formed on the surface of the protective film or the surface of the polarizer layer. After coating and drying to form an adhesive layer, a separator or other type of film may be bonded to the adhesive layer, or after forming an adhesive layer on the separator, the protective film surface or polarizer The pressure-sensitive adhesive layer may be attached to the layer surface and laminated. Further, when the pressure-sensitive adhesive layer is formed on the surface of the protective film or the polarizer layer, a treatment for improving the adhesion to one or both of the surface of the protective film or the polarizer layer, or the pressure-sensitive adhesive layer, for example, corona You may give a process etc.

(Adhesive layer)
Examples of the adhesive constituting the adhesive layer include a water-based adhesive using a polyvinyl alcohol-based resin aqueous solution, a water-based two-component urethane-based emulsion adhesive, and the like. Among these, a polyvinyl alcohol resin aqueous solution is preferably used. Polyvinyl alcohol resins used as adhesives include vinyl alcohol homopolymers obtained by saponifying polyvinyl acetate, which is a homopolymer of vinyl acetate, as well as other single quantities copolymerizable with vinyl acetate. And vinyl alcohol copolymers obtained by saponifying the copolymer with the polymer, and modified polyvinyl alcohol polymers obtained by partially modifying the hydroxyl groups. A polyhydric aldehyde, a water-soluble epoxy compound, a melamine compound, a zirconia compound, a zinc compound, or the like may be added as an additive to the water-based adhesive. When such an aqueous adhesive is used, the adhesive layer obtained therefrom is usually much thinner than 1 μm, and even when the cross section is observed with a normal optical microscope, the adhesive layer is practically not observed. For this reason, it is difficult to fill the thickness difference of the dye-proof layer 35 with the water-based adhesive layer. Therefore, when the water-based adhesive is used, it is desirable to remove the dye-proof layer 35 in the dye-proof layer removing step (S45).

  The method of laminating the film using the water-based adhesive is not particularly limited, but is it possible to uniformly apply the adhesive to one surface of the two films to be bonded and overlap the other film on the coated surface? Alternatively, a method in which an adhesive is poured between two films to be bonded, the two films are sandwiched by a roll or the like, and dried, for example, can be employed. The adhesive is usually applied at a temperature of 15 to 40 ° C after its preparation, and the bonding temperature is usually in the range of 15 to 30 ° C.

  When using an aqueous adhesive, after pasting the film, a drying process is performed to remove water contained in the aqueous adhesive. The drying temperature is preferably in the range of 30 to 90 ° C. When the drying temperature is below 30 ° C., the adhesive surface tends to be peeled off. On the other hand, when the drying temperature exceeds 90 ° C., the optical performance such as the polarizer layer may be deteriorated by heat. The drying time can be about 10 to 1,000 seconds.

  After drying, it may be further cured at room temperature or a slightly higher temperature, for example, at a temperature of about 20 to 45 ° C. for about 12 to 600 hours. The temperature at the time of curing is generally set lower than the temperature adopted at the time of drying.

  Moreover, a photocurable adhesive can also be used as a non-aqueous adhesive. Examples of the photocurable adhesive include a mixture of a photocurable epoxy resin and a photocationic polymerization initiator.

  For pasting of the film with a photocurable adhesive, a conventionally known method can be adopted, for example, casting method, Meyer bar coating method, gravure coating method, comma coater method, doctor plate method, die coating method, Examples thereof include a method in which an adhesive is applied to the adhesive surface of the film by a dip coating method, a spraying method, and the like, and the two films are overlapped. The casting method is a method of spreading and spreading two adhesive films on the surface while moving two coated films in a substantially vertical direction, a substantially horizontal direction, or an oblique direction between them. is there.

  After the adhesive is applied to the surface of the film, the two films are bonded together by sandwiching them with a nip roll or the like. Moreover, the method of pressing this laminated body with a roll etc. and spreading it uniformly can also be used suitably. In this case, the material of the roll can be metal or rubber. Furthermore, a method in which this laminate is passed between rolls and pressed to spread is preferably employed. In this case, the two rolls may be made of the same material or different materials. The adhesive layer after being bonded by a nip roll or the like preferably has a thickness before drying or curing of 0.01 μm or more and 5 μm or less.

In order to improve adhesiveness, surface treatment such as plasma treatment, corona treatment, ultraviolet irradiation treatment, flame (flame) treatment, and saponification treatment may be appropriately performed on the adhesion surface of the film.
The saponification treatment is performed by immersing the film in an alkaline aqueous solution such as sodium hydroxide or potassium hydroxide.

  When bonding using a photocurable adhesive, after laminating | stacking a film, a photocurable adhesive is hardened by irradiating an active energy ray. The light source of the active energy ray is not particularly limited, but an active energy ray having a light emission distribution at a wavelength of 400 nm or less is preferable, and specifically, a low pressure mercury lamp, a medium pressure mercury lamp, a high pressure mercury lamp, an ultrahigh pressure mercury lamp, a chemical lamp, a black light lamp. A microwave excitation mercury lamp, a metal halide lamp and the like are preferably used.

The light irradiation intensity to the photocurable adhesive is appropriately determined depending on the composition of the photocurable adhesive and is not particularly limited, but the irradiation intensity in the wavelength region effective for activating the polymerization initiator is 0.1 to 6, 000 mW / cm ² is preferable. By appropriately selecting the irradiation intensity within this range, the reaction time does not become too long, and the yellowing of the adhesive and the deterioration of the polarizing plate due to the heat radiated from the light source and the heat generated when the photocurable adhesive is cured are prevented. The possibility of occurring can be suppressed. The light irradiation time to the photocurable adhesive is determined according to the photocurable adhesive to be used, and is not particularly limited, but is an integration expressed as the product of the irradiation intensity and the irradiation time. It is preferable that the light intensity is set to be 10 to 10,000 mJ / cm ² . By appropriately selecting the amount of light integrated into the photocurable adhesive within this range, it is possible to generate a sufficient amount of active species derived from the polymerization initiator to allow the curing reaction to proceed more reliably and to increase the irradiation time. However, good productivity can be maintained. The thickness of the adhesive layer after curing is usually about 0.001 to 5 μm, preferably 0.01 μm or more, and preferably 2 μm or less. When the stain-proof layer 35 is not removed in the stain-proof layer removing step (S45), the thickness step of the stain-proof layer 35 can be filled by making the adhesive layer thicker than the thickness of the stain-proof layer 35.

  When the photocurable adhesive between the polarizer layer and the protective film is cured by irradiation with active energy rays, the polarization degree, transmittance and hue of the polarizer layer, and transparency of the protective film, etc. It is preferable to perform the curing under conditions where the various functions of the plate do not deteriorate.

<Drying step (S75)>
In the protective film bonding step (S70), when a solution containing a solvent is used to form the adhesive layer or the pressure-sensitive adhesive layer, the drying step is performed to dry the double-sided bonding film or the single-sided bonding film. (S75) is provided. This drying step (S75) is mainly performed for the purpose of drying the adhesive layer or the pressure-sensitive adhesive layer, and the drying conditions and the like are the same as the drying process described in the above-described washing step (S60). In particular, when an aqueous adhesive such as a polyvinyl alcohol-based resin aqueous solution is used to form an adhesive layer, it is preferably dried at a temperature of 60 ° C. or higher.

<Peeling step (S80)>
After the drying step (S75), the laminate of the polarizer layer 31 and the protective film 41 or the laminate of the polarizer layer 32 and the protective film 42 of the double-sided or single-sided laminated film is a base film. The peeling process (S80) which peels from 1 and obtains the polarizing plates 51 and 52 is performed. The peeling method of a laminated body is not specifically limited, The method similar to the peeling film peeling process currently performed in the normal polarizing plate with an adhesive can be employ | adopted. After the drying step (S75), it may be peeled off as it is, or after it is wound up in a roll shape, it may be peeled off by providing a separate peeling step. The polarizing plates 51 and 52 can also be provided as a set of polarizing plates that are used by being disposed on both sides of a liquid crystal cell in a liquid crystal display device, for example. The polarizing plates 51 and 52 on which the protective films 41 and 42 are bonded on one side can be used as they are, or the surface of the polarizer layer 31 on the opposite side to the surface on which the protective film 41 of the polarizing plate 51 is provided, Further, a protective film or another optical layer described later can be laminated and used on the surface of the polarizer layer 32 on the side opposite to the surface on which the protective film 42 of the polarizing plate 52 is provided. A polarizing plate 51 in which a region 36 that does not exhibit polarizing ability is formed in the polarizer layer 31 is a polarizing plate defined in the present invention. In this polarizing plate 51, the thickness of the polarizer layer 31 is 10 μm or less. In addition, the polarizing plate 51 may have a configuration in which protective films are provided on both surfaces of the polarizer layer 31.

[Other optical layers]
The polarizing plate produced by the method of the present invention can be used as a polarizing plate in which other optical layers are laminated in practical use. Moreover, the said protective film may have a function of these optical layers.

  Examples of other optical layers include a reflective polarizing film that transmits certain types of polarized light and reflects polarized light that exhibits the opposite properties, a film with an antiglare function having an uneven shape on the surface, and a surface antireflection function. Examples thereof include an attached film, a reflective film having a reflective function on the surface, a transflective film having both a reflective function and a transmissive function, and a viewing angle compensation film.

  As a commercial product corresponding to a reflective polarizing film that transmits certain types of polarized light and reflects polarized light that exhibits the opposite properties, it is sold by, for example, 3M [Sumitomo 3M Co., Ltd. in Japan] DBEF ”and“ APF ”(both are trade names). Examples of the viewing angle compensation film include an optical compensation film in which a liquid crystal compound is applied to the substrate surface, and is oriented / fixed, a retardation film made of a polycarbonate resin, a retardation film made of a cyclic polyolefin resin, and the like. . Commercially available products that correspond to optical compensation films that have a liquid crystal compound applied to the substrate surface and are oriented and fixed include “WV film” sold by FUJIFILM Corporation, JX Nippon Mining & Energy Corporation ("NH film", "NV film", etc.) (both are trade names). In addition, commercially available products corresponding to retardation films made of cyclic polyolefin-based resins include “Arton Film” sold by JSR Corporation and “Essina Retardation Film” sold by Sekisui Chemical Co., Ltd. And “ZEONOR FILM” sold by Nippon Zeon Co., Ltd. (all trade names).

The retardation film is a film in which the in-plane retardation value Re, the thickness direction retardation value Rth, the Nz coefficient, and the like are appropriately controlled by uniaxial stretching or biaxial stretching. Here, the in-plane retardation value Re, the thickness direction retardation value Rth and Nz coefficient, the refractive index in the in-plane slow axis direction n _x of the film, and the slow axis in-plane fast axis direction (in-plane the refractive index n _y in orthogonal directions to), the refractive index n _z in the thickness direction, the thickness is taken as d, each of which is defined by the following equation.

_{Re = (n x -n y)} × d
Rth = [(n _x + n _y ) / 2−n _z ] × d
_{Nz = (n x -n z)} / (n x -n y)

[Visibility corrected single transmittance]
In the polarizing laminated film 38 or the polarizing plate 51, the region 36 that does not exhibit the polarizing ability due to the presence of the dye-proof layer 35 preferably has a visibility corrected single transmittance exceeding 80%, and more preferably 90 % Or more is more preferable, and it is ideal that it is colorless. However, in the case of design printing, it will naturally show some absorption.

The single transmittance is a numerical value defined by the following formula;
Single transmittance (λ) = 0.5 × (Tp (λ) + Tc (λ)).

  Here, Tp (λ) is the transmittance (%) of the polarizer layer measured in the relationship between the linearly polarized light with the incident wavelength λnm and the parallel Nicol, and Tc (λ) is the linearly polarized light with the incident wavelength λnm. The transmittance (%) of the polarizer layer measured in a crossed Nicols relationship, both of which can be obtained by measuring polarized ultraviolet-visible absorption spectra with a spectrophotometer. A value obtained by applying sensitivity correction called visibility correction to the single transmittance (λ) obtained for each wavelength is referred to as visibility correction single transmittance (Ty). The visibility corrected single transmittance (Ty) can be easily measured using, for example, a spectrophotometer (model number “V7100”) manufactured by JASCO Corporation.

  In the measurement of the visibility corrected single transmittance, the absolute value of the visibility corrected single transmittance slightly varies depending on the difference in interface reflectance depending on the presence or absence of the protective film and the type of the protective film.

  EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to these examples. In the examples, “%” and “part” representing the content or amount used are based on weight unless otherwise specified.

[Example 1]
As shown in the flowchart of FIG. 2, a polarizing plate 51 having a high transmittance region that does not exhibit polarizing ability was produced from the double-sided polarizing laminated film 38.

(A) Base film On both sides of a resin layer comprising a random copolymer of propylene / ethylene containing about 5% ethylene units (trade name “Sumitomo Nobrene W151”, melting point 138 ° C. obtained from Sumitomo Chemical Co., Ltd.) Using a multilayer extrusion molding machine, a base film 1 having a three-layer structure in which a resin layer made of a propylene homopolymer [trade name “Sumitomo Nobrene FLX80E4” obtained from Sumitomo Chemical Co., Ltd., melting point 163 ° C.] is disposed is used. Produced by coextrusion molding. The total thickness of the obtained base film 1 was 90 μm, and the thickness ratio (FLX80E4 / W151 / FLX80E4) of each layer was 3/4/3.

(B) Primer layer forming step Polyvinyl alcohol powder [trade name “Z-200” obtained from Nippon Synthetic Chemical Industry Co., Ltd.] having an average degree of polymerization of 1,100 and an average degree of saponification of 99.5 mol% is 95 ° C. An aqueous solution having a concentration of 3% was prepared by dissolving in hot water. To the obtained 3% aqueous polyvinyl alcohol solution, a crosslinking agent comprising 30% aqueous solution of a water-soluble epoxy resin [trade name “Smileze Resin 650” obtained from Taoka Chemical Industry Co., Ltd.] was added to a solid content of 6 parts of polyvinyl alcohol. Was mixed at a ratio of 5 parts to prepare a primer solution. One side of the base film 1 shown above is subjected to corona treatment, and the corona treatment surface is coated with the primer solution prepared above using a small-diameter gravure coater and dried at 80 ° C. for 10 minutes, A primer layer having a thickness of 0.2 μm was formed.

  Furthermore, the other surface of the base film 1 was also subjected to corona treatment, and similarly a primer solution was applied and dried to produce a film in which a primer layer was formed on both surfaces of the base film 1.

(C) Resin layer forming step Polyvinyl alcohol powder (trade name “PVA124” obtained from Kuraray Co., Ltd.) having an average degree of polymerization of 2,400 and an average degree of saponification of 98.0 to 99.0 mol% was heated at 95 ° C. An aqueous polyvinyl alcohol solution having a concentration of 8% was prepared by dissolving in water. The obtained aqueous solution was applied to the surface of the primer layer formed on one surface of the base film 1 using a lip coater, and then continuously, 80 ° C. for 2 minutes, 70 ° C. for 2 minutes, And the drying process for 4 minutes was performed at 60 degreeC, and the single-sided coating film 16 which consists of two layers, the base film 1 and the 1st polyvinyl alcohol-type resin layer 11, was produced.

  Next, the surface of the primer layer formed on the other surface of the base film 1 in the single-side coated film 16 is subjected to the same coating and drying treatment, and the first polyvinyl alcohol-based resin layer 11 and the base film A double-sided coating film 17 comprising the first and second polyvinyl alcohol-based resin layers 12 was produced. At this time (before stretching), the thicknesses of the polyvinyl alcohol resin layers 11 and 12 were 10.5 μm and 10.2 μm, respectively.

(D) Stretching step The double-sided coated film 17 was subjected to 5.8-fold free end longitudinal uniaxial stretching at 160 ° C. using an inter-roll longitudinal stretching machine. The thicknesses of the two polyvinyl alcohol-based resin layers present in the double-sided coated film after stretching were 5 μm ± 0.1 μm, respectively.

(E) Dye-proofing process On the first stretched polyvinyl alcohol-based resin layer 21 of the obtained laminated stretched film 26, paraffin dissolved by heat was applied and cured into a circle having a diameter of 5 mm to form a dye-resistant layer 35. .

(F) Dyeing process and bridge | crosslinking process The laminated stretched film 26 which extended | stretched and provided the anti-dyeing layer 35 was immersed in the dyeing solution of 30 degreeC which has the composition shown below for 140 second, and performed the dyeing | staining process. Subsequently, the excess iodine solution was washed away with pure water at 10 ° C., and then immersed in a crosslinking solution at 76 ° C. having the following composition for 600 seconds to carry out a crosslinking treatment.

<Dyeing solution>
Water 100 parts Iodine 0.35 parts Potassium iodide 10 parts <Crosslinking solution>
Water 100 parts Boric acid 9.5 parts Potassium iodide 5 parts

(G) Washing process The film after the crosslinking treatment was washed with 10 ° C. pure water for 4 seconds to remove paraffin. Finally, it was dried at 80 ° C. for 300 seconds. Through the above-described steps, a double-sided polarizing laminate film 38 in which the polyvinyl alcohol resin layers 11 and 12 formed on both surfaces of the base film 1 became the polarizer layers 31 and 32 was obtained.

(H) Protective film laminating step Polyvinyl alcohol powder having an average degree of polymerization of 1,800 [trade name “KL-318” obtained from Kuraray Co., Ltd.] was dissolved in hot water at 95 ° C. to obtain an aqueous solution having a concentration of 3%. Prepared. The same 3% polyvinyl alcohol aqueous solution was mixed with the same cross-linking agent “Smileze Resin 650” used in the previous primer layer forming step at a ratio of 1 part to 2 parts of the solid content of polyvinyl alcohol. An adhesive solution was obtained. After applying the polyvinyl alcohol-based adhesive solution prepared here on both sides of the double-sided polarizing laminate film 38 obtained in the previous step, a triacetyl cellulose film as a protective film 41, 42 on each adhesive-coated surface [Product name “KC4UY” obtained from Konica Minolta Advanced Layer Co., Ltd.] was bonded and dried at 80 ° C. for 5 minutes, so that protective film 41, polarizer layer 31, substrate film 1, polarizer layer 32 were obtained. And the double-sided bonding film 46 which consists of five layers of the protective film 42 was obtained.

(I) Peeling process From the double-sided bonding film 46, the 1st polarizing plate 51 which is the laminated body of the polarizer layer 31 and the protective film 41 was peeled. The base film 1 is peeled off from the remaining film (the laminate of the base film 1, the polarizer layer 32 and the protective film 42), and the second polarizing plate 52 which is a laminate of the polarizer layer 32 and the protective film 42. Got. The first polarizing plate 51 had a region 36 that was a colorless and transparent circle having a diameter of 5 mm and did not exhibit polarizing ability.

[Example 2]
In this example, the dye-proof layer 35 was formed from a cured product of the photocurable resin composition, and the other components were made in the same manner as in Example 1 to produce a polarizing plate 51 having a high transmittance region that does not exhibit polarization ability.

(A) Preparation of photocurable resin composition The following components were mixed and degassed to prepare a photocurable resin composition in a liquid state.

3,4-epoxycyclohexylmethyl 3,4-epoxycyclohexanecarboxylate 75 parts 1,4-butanediol diglycidyl ether 20 parts 2-ethylhexyl glycidyl ether 5 parts triarylsulfonium hexafluorophosphate-based photocationic polymerization initiator
2.25 parts

  The photocationic polymerization initiator used was obtained in the form of a 50% propylene carbonate solution. The blending amount (2.25 parts) shown above is the solid content.

(B) Dye-proofing step A mask having a circular hole with a diameter of 5 mm is placed on the first stretched polyvinyl alcohol-based resin layer 21 of the laminated stretched film 26 after being stretched in (d) of Example 1. Then, the photocurable resin composition prepared previously was applied through the mask using a bar coater so as to have a thickness of 1 μm. Then, the mask is removed together with the photocurable resin composition coated thereon, and a photocurable resin composition coating layer having a diameter of 5 mm corresponding to the hole of the mask is formed on the first stretched polyvinyl alcohol-based resin layer 21. In the state where only the coating layer is present, the coated layer is placed on top and placed on an ultraviolet irradiation device with a belt conveyor to which an ultraviolet lamp “D bulb” manufactured by Fusion UV Systems is attached, and the integrated light quantity becomes 250 mJ / cm ^2. As described above, the photocurable resin composition was cured by irradiating ultraviolet rays. Thus, on the first stretched polyvinyl alcohol-based resin layer 21 of the laminated stretched film 26, a circular dye-proof layer 35 having a diameter of 5 mm made of a cured product of the photocurable resin composition was formed.

(C) Dyeing step, cross-linking step, and washing step Thereafter, 145 seconds of immersion in the same dyeing solution used in Example 1 (f), followed by the same conditions as in Example 1 (f) and (g) Crosslinking and washing with water were performed. During washing with water, the circular dye-proof layer 35 is not removed.

(D) Protective film laminating step 20 μm thick retardation film made of cyclic olefin resin [trade name “Arton Film” obtained from JSR Co., Ltd., slow in the width direction (TD) of the long roll film Corona treatment is performed on one surface of which there is an axis, Re = 115 nm, Nz coefficient = 1.4), and the film thickness after curing of the previously prepared photocurable resin composition is about 3 μm. As described above, coating was performed using a bar coater. Next, the coating layer side was bonded to both surfaces of the double-sided polarizing laminate film 38 in which the dye-proof layer 35 was formed on the first stretched polyvinyl alcohol resin layer 21. In this state, it is placed on the same ultraviolet irradiation device with a belt conveyor as above, and the photocurable resin composition is cured by irradiating with ultraviolet rays, so that the protective film 41, the polarizer layer 31, the substrate film 1, the polarizer layer 32, and A double-sided laminated film 46 consisting of five layers of the protective film 42 was obtained. A portion of the polarizer layer 31 corresponding to the stain-resistant layer 35 is not dyed, and is a region 36 that does not exhibit polarization ability.

(E) Peeling process From the double-sided bonding film 46 obtained above, the 1st polarizing plate 51 which is a laminated body of the polarizer layer 31 and the protective film 41 was peeled. The base film 1 is peeled off from the remaining film (the laminate of the base film 1, the polarizer layer 32 and the protective film 42), and the second polarizing plate 52 which is a laminate of the polarizer layer 32 and the protective film 42. Got. The first polarizing plate 51 had a region 36 that was a colorless and transparent circle having a diameter of 5 mm and did not exhibit polarizing ability.

[Measurement of transmittance of polarizing plate]
Using a spectrophotometer “V7100” manufactured by JASCO Corporation, the polarization performance of the polarizing plate obtained in each example was measured. In the measurement, light was incident from the polarizer layer side. Table 1 summarizes the visibility-corrected single transmittance of the region 36 that does not show the polarization ability formed corresponding to the stain-proof layer 35 of the first polarizing plate 51 and the other region that shows the polarization performance.

  A polarizing plate having a transparent region in which a protective film is bonded to one surface of the polarizer layer and does not exhibit polarizing ability, obtained as described above, for example, forms a pressure-sensitive adhesive layer on the polarizer layer, and a liquid crystal cell Can be pasted. 3 is a cross-sectional view schematically showing a state in which an adhesive layer is formed on the polarizer layer of the polarizing plate obtained in Example 1, and FIG. 4 shows the polarizing plate obtained in Example 2. It is sectional drawing which shows typically the state which formed the adhesive layer on the polarizer layer.

  In the polarizing plate 51 shown in FIG. 3, a protective film 41 is bonded to one surface of a polarizer layer 31 having a region 36 that is transparent and does not exhibit polarization ability, with an adhesive layer 61 interposed therebetween, and the other surface of the polarizer layer 31. Has a configuration in which an adhesive layer 62 is provided.

  On the other hand, in the polarizing plate 51 shown in FIG. 4, a stain-proof layer 35 is formed on a part of one surface of the polarizer layer 31, and a portion covered with the stain-proof layer 35 of the polarizer layer 31 is transparent and has a polarizing ability. In which the protective film 41 is bonded to the side of the dye-proof layer 35 via the adhesive layer 61, and the adhesive layer 62 is provided on the other surface of the polarizer layer 31. It has become. In FIG. 4, the dye-resistant layer 35 remains as it is, but in Example 2, the dye-resistant layer 35 and the adhesive layer 61 thereon are formed from the same photocurable resin composition. Therefore, for example, even when the cross section is observed with an optical microscope, the interface between the dye-resisting layer 35 and the adhesive layer 61 cannot be distinguished.

1 …… Base film,
11: First polyvinyl alcohol-based resin layer,
12: Second polyvinyl alcohol resin layer,
16 …… Single-side coated film,
17 …… Double coated film,
21 …… First stretched polyvinyl alcohol resin layer,
22 …… Second stretched polyvinyl alcohol resin layer,
26 …… Laminated stretched film,
31, 32 ... Polarizer layer,
35 …… Dye-proof layer,
36 …… A region that does not show polarization ability,
38 …… Double-sided polarizing laminated film,
41, 42 ... protective film,
46 …… Double-sided adhesive film,
51, 52 ... Polarizing plate,
61 …… Adhesive layer,
62 …… Adhesive layer,
70 …… Perforated polarizing plate,
72: A hole provided in the polarizing plate.

Claims (2)

A method for producing a polarizing laminate film comprising a substrate film and a polarizer layer formed on the substrate film,
A resin layer forming step of forming a polyvinyl alcohol resin layer on the surface of the base film to obtain a laminated film;
A stretching step of stretching the resulting laminated film to obtain a laminated stretched film;
A stain-proofing step of forming a stain-proof layer on a part of the surface of the polyvinyl alcohol-based resin layer of the obtained laminated stretched film;
A dyeing step of contacting the laminated stretched film formed with the dye-proof layer with a dye solution containing a dichroic dye, and dyeing the polyvinyl alcohol-based resin layer with the dichroic dye;
A stain-resistant layer removing step for removing the stain-resistant layer;
A cross-linking step of immersing the laminated stretched film in a solution containing a cross-linking agent to form a polarizer layer ,
The manufacturing method of the polarizing laminated film which has an area | region which does not show polarization ability characterized by providing in this order . A polarizing plate comprising: a step of removing the base film from the polarizing laminate film obtained by the production method according to claim 1; and a step of bonding a protective film to at least one surface of the polarizer layer. A manufacturing method comprising:
The polyvinyl alcohol-based resin layer in the region where the dye-proof layer is formed does not exhibit polarizing ability, and the polarizer layer made of the polyvinyl alcohol-based resin dyed with the dichroic dye has a thickness of 10 μm or less. The manufacturing method of the polarizing plate characterized by these.

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