JP6806453B2 - A method for manufacturing a single-protective polarizing film with a transparent resin layer, a method for manufacturing a polarizing film with an adhesive layer, and a method for manufacturing an optical laminate. - Google Patents

Description

The present invention relates to a method for producing a single protective polarizing film with a transparent resin layer. Further, the present invention is a method for producing a polarizing film with an adhesive layer in which an adhesive layer is formed on the transparent resin layer of the one-sided protective polarizing film with the transparent resin layer, and optics using the polarizing film with the adhesive layer. The present invention relates to a method for producing a laminate. The one-sided protective polarizing film with a transparent resin layer and the polarizing film with an adhesive layer obtained by the production method of the present invention can be used alone or as an optical laminate obtained by laminating them, such as a liquid crystal display (LCD) or an organic EL display. An image display device such as a device can be formed.

Liquid crystal display devices are rapidly expanding into the market for watches, mobile phones, PDAs, notebook computers, personal computer monitors, DVD players, TVs, and the like. The liquid crystal display device visualizes the polarization state due to switching of the liquid crystal, and a polarizer is used because of the display principle.

As the polarizer, since it has high transmittance and high degree of polarization, for example, an iodine-based polarizer having a structure in which iodine is adsorbed on a polyvinyl alcohol film and stretched is most widely used. Such a polarizer has an extremely weak mechanical strength, and has a disadvantage that it shrinks due to heat or moisture and the polarization function is significantly reduced. Therefore, the obtained polarizing element is immediately bonded to the protective film coated with the adhesive via the adhesive and used as the polarizing film.

On the other hand, image display devices such as liquid crystal display devices are becoming thinner, and polarizing films are also required to be thinner. Therefore, the thinning is also performed for the polarizer. Further, the thinning can be performed by using a single protective polarizing film in which a protective film is provided only on one side of the polarizer and no protective film is provided on the other side. Since such a single protective polarizing film has one less protective film than a double protective polarizing film in which protective films are provided on both sides of the polarizer, it can be made thinner.

On the other hand, since the single protective polarizing film has insufficient durability due to thermal shock, a film having a protective layer (transparent resin layer) on the polarizer side has been proposed (see, for example, Patent Documents 1 and 2).

Further, as a method for producing a polarizing laminated film, a resin layer is formed by providing an uncoated portion in which a resin solution is not applied in a region of 0.5 cm or more from both ends in the width direction of the base film. A method has been proposed in which the uncoated portion is cut and removed from the laminated film, and then stretched and dyed to produce a polarizing laminated film (see, for example, Patent Document 3).

JP-A-2010-09027 Japanese Unexamined Patent Publication No. 2013-160775 Japanese Unexamined Patent Publication No. 2011-21250

In Patent Documents 1 and 2, a protective layer (transparent resin layer) is formed on the single protective polarizing film, but such a polarizing film often curls, and when the obtained polarizing film is conveyed, it is polarized. There were cases where the edge of the film was broken, the film was broken due to the breakage, and other members were rubbed during lamination.

In the method for producing a polarizing laminated film of Patent Document 3, a warp phenomenon of the obtained film is suppressed by providing an uncoated portion of 0.5 cm or more and removing the uncoated portion. In the method of Patent Document 3, a step of removing the uncoated portion is required, which complicates the manufacturing process.

Therefore, an object of the present invention is to provide a method for producing a single-protective polarizing film with a transparent resin layer capable of suppressing curl generation. A further object of the present invention is to provide a method for producing a polarizing film with an adhesive layer and a method for producing an optical laminate.

As a result of diligent studies, the present inventors have found that the above problems can be solved by the following method for producing a single-protective polarizing film with a transparent resin layer, and have reached the present invention.

That is, the present invention is a piece with a transparent resin layer having a single protective polarizing film having a protective film on only one side of the polarizer and a transparent resin layer provided on the other surface of the polarizer of the single protective polarizing film. It is a method of manufacturing a protective polarizing film.
The polarizer contains a polyvinyl alcohol-based resin and has a thickness of 10 μm or less.
The transparent resin layer is formed by a step of applying a coating liquid containing a resin component or a curable component capable of forming a transparent resin layer to the polarizer, and a step of solidifying or curing the obtained coating film. Formed,
In the coating step of the coating liquid, there is an uncoated portion in which the coating liquid is not applied in a region of less than 20 mm from both ends in the width direction of the polarizer, or over the entire width direction of the polarizer. The present invention relates to a method for producing a single-protective polarizing film with a transparent resin layer, which comprises applying a coating liquid.

It is preferable that the coating liquid is applied by applying the coating liquid over the entire width direction of the polarizer.

The width of the polarizer is preferably 1100 to 2000 mm.

The transparent resin layer is formed by solidifying the coating film, and it is preferable that the solidification is performed by drying.

The drying temperature is preferably 120 ° C. or lower.

The drying time is preferably 180 seconds or less.

It is preferable that the coating liquid is a coating liquid containing a resin component, and the resin component is a polyvinyl alcohol-based resin.

The present invention also comprises a step of forming an adhesive layer on the transparent resin layer of the one-sided protective polarizing film with the transparent resin layer obtained by the above-mentioned production method, wherein the polarizing film with an adhesive layer is produced. Regarding the method.

Further, the present invention is characterized by comprising a step of bonding the polarizing film with the pressure-sensitive adhesive layer obtained by the above-mentioned manufacturing method to an optical member via the pressure-sensitive adhesive layer without winding the polarizing film. Regarding the method.

In the method for producing a single-protective polarizing film with a transparent resin layer of the present invention, when a coating liquid containing a resin component or a curable component capable of forming a transparent resin layer is applied to a polarizing element, the polarizing element is used. A transparent resin obtained because it has an uncoated portion in which the coating liquid is not applied in a region of less than 20 mm from both ends in the width direction, or the coating liquid is applied over the entire width direction of the polarizer. It is possible to suppress the occurrence of curl of the layered single-protective polarizing film. Further, the polarizing film with an adhesive layer in which the adhesive layer is provided on the transparent resin layer of the one-sided protective polarizing film with the transparent resin layer also suppresses the occurrence of curl. Therefore, the one-sided protective polarizing film with a transparent resin layer and the polarizing film with an adhesive layer obtained by the manufacturing method of the present invention are laminated on an optical member used for an image display device or the like without being wound on a roll or the like after manufacturing. can do.

This is an example of a schematic cross-sectional view of a one-sided protective polarizing film with a transparent resin layer obtained by the production method of the present invention. This is an example of a schematic cross-sectional view of a one-sided protective polarizing film with a transparent resin layer obtained by the production method of the present invention.

1. 1. Method for Manufacturing Single Protective Polarizing Film with Transparent Resin Layer The method for manufacturing single protective polarizing film with transparent resin layer of the present invention is
A single-protective polarizing film having a protective film on only one side of the polarizer and a single-protective polarizing film with a transparent resin layer having a transparent resin layer provided on the other surface of the polarizer of the single-protective polarizing film are manufactured. It is possible,
The polarizer contains a polyvinyl alcohol-based resin and has a thickness of 10 μm or less.
The transparent resin layer is formed by a step of applying a coating liquid containing a resin component or a curable component capable of forming a transparent resin layer to the polarizer, and a step of solidifying or curing the obtained coating film. Formed,
In the coating step of the coating liquid, there is an uncoated portion in which the coating liquid is not applied in a region of less than 20 mm from both ends in the width direction of the polarizer, or over the entire width direction of the polarizer. It is characterized by applying a coating liquid.

The one-sided protective polarizing film with a transparent resin layer obtained by the production method of the present invention will be described with reference to FIGS. 1 and 2. However, the present invention is not limited to these figures.

The single-sided protective polarizing film 3 used in the present invention has the protective film 2 only on one side of the polarizer 1. The polarizer 1 and the protective film 2 can be laminated via an intervening layer (not shown) such as an adhesive layer, an adhesive layer, and an undercoat layer (primer layer). In the production method of the present invention, a transparent resin layer 4 is formed on a surface (another surface) of the polarizing element 1 of the single protective polarizing film 3 that does not have the protective film 2, and the single protective polarizing film with the transparent resin layer is provided. This is a method for producing the film 10.

The transparent resin layer 4 is formed by applying a coating solution containing a resin component or a curable component capable of forming the transparent resin layer 4 to the polarizer 1, and solidifying or solidifying the obtained coating film. It is formed by the curing process. In the coating step of the coating liquid, as shown in FIG. 1, the coating liquid is not applied in the regions of less than 20 mm from both ends in the width direction (A direction in the drawing) of the polarizer 1 to the inside. It is characterized by having a portion 5 or, as shown in FIG. 2, applying a coating liquid over the entire width direction of the polarizer 1 (having no uncoated portion). By applying in this way, it is possible to suppress curling of the obtained single-sided protective polarizing film 10 with a transparent resin layer, and after production, the optical member used for an image display device or the like without being wound on a roll or the like. Can be pasted on. Here, the width direction of the polarizer 1 means a direction orthogonal to the stretching direction (conveying direction) of the polarizer 1.

Further, in the coating, when the uncoated portion is provided, the uncoated portion is a region of less than 20 mm inward from both ends in the width direction of the polarizer, preferably a region of 15 mm or less, preferably 10 mm. The following regions are more preferable. By keeping the uncoated portion within the above range, it is preferable in that curling of the obtained single-protective polarizing film with a transparent resin layer can be suppressed. The lower limit of the region of the uncoated portion is not particularly limited, and the smaller the value, the more preferable. The method of applying the coating liquid over the entire width direction of the polarizer, that is, having no uncoated portion. Especially preferable.

Further, in the coating, when the uncoated portion is provided, the uncoated portion is preferably a region of 5% or less with respect to the width of the polarizer from both ends in the width direction of the polarizer to the inside. The region is more preferably less than 3% with respect to the width of the polarizer, and more preferably the region is 2% or less with respect to the width of the polarizer. By keeping the uncoated portion within the above range, it is preferable in that curling of the obtained single-protective polarizing film with a transparent resin layer can be suppressed. The lower limit of the region of the uncoated portion is not particularly limited, and the smaller the value, the more preferable. The method of applying the coating liquid over the entire width direction of the polarizer, that is, 0% with respect to the width of the polarizer. (No uncoated portion) is particularly preferable.

Hereinafter, each step of the production method of the present invention will be described.

1-1. Coating Liquid Coating Step In the production method of the present invention, a resin component or a transparent resin layer can be formed on the surface (other surface) of the polarizing element 1 of the one-side protective polarizing film 3 that does not have the protective film 2. It includes a step of applying a coating liquid containing a curable component. The coating method is as described above.

(1) Single-protective polarizing film (1-1) Polarizer In the present invention, a polarizing element having a thickness of 10 μm or less is used. The thickness of the polarizer is preferably 8 μm or less, more preferably 7 μm or less, still more preferably 6 μm or less. On the other hand, the thickness of the polarizer is preferably 2 μm or more, more preferably 3 μm or more. Such a thin polarizing element has less uneven thickness, excellent visibility, and less dimensional change, so that it has excellent durability against thermal shock.

As the polarizer 1, one using a polyvinyl alcohol-based resin is used. The polarizer 1 includes, for example, a hydrophilic polymer film such as a polyvinyl alcohol-based film, a partially formalized polyvinyl alcohol-based film, an ethylene-vinyl acetate copolymerization system partially saponified film, and two colors of iodine and a bicolor dye. Examples thereof include a uniaxially stretched film by adsorbing a sex substance, a polyene-based oriented film such as a dehydrated product of polyvinyl alcohol and a dehydrogenated product of polyvinyl chloride. Among these, a polarizer made of a polyvinyl alcohol-based film and a dichroic substance such as iodine is preferable.

A polarizer obtained by dyeing a polyvinyl alcohol-based film with iodine and uniaxially stretching it can be produced, for example, by dyeing polyvinyl alcohol by immersing it in an aqueous solution of iodine and stretching it 3 to 7 times its original length. If necessary, boric acid, zinc sulfate, zinc chloride and the like may be contained, or the mixture may be immersed in an aqueous solution such as potassium iodide. Further, if necessary, the polyvinyl alcohol-based film may be immersed in water and washed with water before dyeing. In addition to being able to clean the surface of the polyvinyl alcohol film and blocking inhibitors by washing the polyvinyl alcohol film with water, it also has the effect of preventing non-uniformity such as uneven dyeing by swelling the polyvinyl alcohol film. is there. Stretching may be performed after dyeing with iodine, stretching while dyeing, or stretching and then dyeing with iodine. It can be stretched even in an aqueous solution such as boric acid or potassium iodide or in a water bath.

It is preferable that the polarizer 1 contains boric acid from the viewpoint of stretch stability and optical durability. Further, the boric acid content contained in the polarizer 1 is preferably 25% by weight or less, more preferably 20% by weight or less, based on the total amount of the polarizer, from the viewpoint of suppressing the generation of through cracks and nanoslits and suppressing expansion. 18% by weight or less is more preferable, and 16% by weight or less is particularly preferable. When the boric acid content in the polarizer 1 exceeds 20% by weight, the shrinkage stress of the polarizer 1 increases and through cracks are likely to occur even when the thickness of the polarizer 1 is controlled to 10 μm or less. Therefore, it is not preferable. On the other hand, from the viewpoint of stretching stability and optical durability of the polarizer 1, the boric acid content with respect to the total amount of the polarizer is preferably 10% by weight or more, more preferably 12% by weight or more.

As a thin polarizer, typically
Japanese Patent No. 4751486,
Japanese Patent No. 4751481
Patent No. 4815544,
Japanese Patent No. 5048120,
International Publication No. 2014/07759 Pamphlet,
International Publication No. 2014/077636 Pamphlet,
Etc., or the thin polarizing element obtained from the manufacturing method described in these.

The polarizer 1 has an optical characteristic represented by a simple substance transmittance T and a degree of polarization P, which is expressed by the following equation P> − (10 ^0.929 T ^-42.4 -1) × 100 (where T <42.3). Or,
P ≧ 99.9 (however, T ≧ 42.3)
It is preferable that the configuration is such that the above conditions are satisfied. A polarizer configured to satisfy the above conditions primarily has the performance required for a display for a liquid crystal television using a large display element. Specifically, the contrast ratio is 1000: 1 or more and the maximum brightness is 500 cd / m ² or more. As another application, for example, it is bonded to the visual side of an organic EL display device.

The thin polarizer is patented in Patent No. 4751486, in that it can be stretched at a high magnification and the polarization performance can be improved even in a manufacturing method including a step of stretching in a laminated state and a step of dyeing. Those obtained by a production method including a step of stretching in an aqueous boric acid solution as described in Japanese Patent No. 4751481 and Japanese Patent No. 4815544 are preferable, and particularly described in Japanese Patent No. 4751481 and Japanese Patent No. 4815544. It is preferably obtained by a production method including a step of auxiliary stretching in the air before stretching in a certain boric acid aqueous solution. These thin polarizers can be obtained by a production method including a step of stretching a polyvinyl alcohol-based resin layer and a stretching resin base material in a laminated state and a step of dyeing. With this manufacturing method, even if the polyvinyl alcohol-based resin layer is thin, it can be stretched without any trouble such as breakage due to stretching because it is supported by the stretching resin base material.

(1-2) Protective film As the material constituting the protective film 2, it is preferable that the material is excellent in transparency, mechanical strength, thermal stability, moisture blocking property, isotropic property and the like. For example, polyester polymers such as polyethylene terephthalate and polyethylene naphthalate, cellulose polymers such as diacetyl cellulose and triacetyl cellulose, acrylic polymers such as polymethyl methacrylate, and styrene such as polystyrene and acrylonitrile-styrene copolymer (AS resin). Examples thereof include based polymers and polycarbonate polymers. Further, polyethylene, polypropylene, polyolefin having a cyclo- or norbornene structure, polyolefin-based polymer such as ethylene / propylene copolymer, vinyl chloride-based polymer, amide-based polymer such as nylon or aromatic polyamide, imide-based polymer, sulfone-based polymer. , Polyether sulfone polymer, polyether ether ketone polymer, polyphenylene sulfide polymer, vinyl alcohol polymer, vinylidene chloride polymer, vinyl butyral polymer, allylate polymer, polyoxymethylene polymer, epoxy polymer, or the above. Polymer blends and the like are also examples of polymers that form the protective film.

In addition, the protective film 2 may contain one or more kinds of arbitrary suitable additives. Examples of the additive include an ultraviolet absorber, an antioxidant, a lubricant, a plasticizer, a mold release agent, a color retardant, a flame retardant, a nucleating agent, an antistatic agent, a pigment, a colorant and the like. The content of the thermoplastic resin in the protective film is preferably 50 to 100% by mass, more preferably 50 to 99% by mass, further preferably 60 to 98% by mass, and particularly preferably 70 to 97% by mass. If the content of the thermoplastic resin in the protective film is less than 50% by mass, the high transparency inherent in the thermoplastic resin may not be sufficiently exhibited.

As the protective film 2, a retardation film, a brightness improving film, a diffusion film and the like can also be used. Examples of the retardation film include those having a frontal retardation of 40 nm or more and / or a thickness direction retardation of 80 nm or more. The front phase difference is usually controlled in the range of 40 to 200 nm, and the thickness direction phase difference is usually controlled in the range of 80 to 300 nm. When a retardation film is used as the protective film, the retardation film also functions as a polarizer protective film, so that the thickness can be reduced.

Examples of the retardation film include a birefringent film obtained by uniaxially or biaxially stretching a thermoplastic resin film. The stretching temperature, stretching ratio, and the like are appropriately set depending on the retardation value, the film material, and the thickness.

The thickness of the protective film 2 can be appropriately determined, but is generally preferably 3 to 200 μm, more preferably 3 to 100 μm, in terms of workability such as strength and handleability, and thin layer property. Is preferable. In particular, the thickness of the protective film (when the film is formed in advance) is preferably 10 to 60 μm, more preferably 10 to 50 μm from the viewpoint of transportability. On the other hand, the thickness of the protective film (when formed by coating and curing) is preferably 3 to 25 μm, more preferably 3 to 20 μm from the viewpoint of transportability. The protective film may be used in a plurality of sheets or a plurality of layers.

A functional layer such as a hard coat layer, an antireflection layer, a sticking prevention layer, a diffusion layer or an antiglare layer can be provided on the surface of the protective film 2 to which the polarizer 1 is not adhered. The functional layers such as the hard coat layer, the antireflection layer, the sticking prevention layer, the diffusion layer and the antiglare layer can be provided on the protective film 2 itself, and are separately provided separately from the protective film. You can also.

(1-3) Intervening layer The protective film 2 and the polarizer 1 can be laminated via an intervening layer such as an adhesive layer, an adhesive layer, and an undercoat layer (primer layer). At this time, it is desirable that both are laminated without an air gap by an intervening layer. The intervening layer between the polarizer 1 and the protective film 2 is not shown in the figure.

The adhesive layer is formed by the adhesive. The type of adhesive is not particularly limited, and various adhesives can be used. The adhesive layer is not particularly limited as long as it is optically transparent, and various forms such as water-based, solvent-based, hot-melt-based, and active energy ray-curable type are used as the adhesive. Alternatively, an active energy ray-curable adhesive is suitable.

Examples of the water-based adhesive include isocyanate-based adhesives, polyvinyl alcohol-based adhesives, gelatin-based adhesives, vinyl-based latex-based adhesives, and water-based polyesters. The water-based adhesive is usually used as an adhesive composed of an aqueous solution, and usually contains 0.5 to 60% by weight of a solid content.

The active energy ray-curable adhesive is an adhesive whose curing proceeds by active energy rays such as electron beam and ultraviolet rays (radical curing type, cationic curing type). For example, in the form of electron beam curing type and ultraviolet curing type. Can be used. As the active energy ray-curable adhesive, for example, a photoradical curable adhesive can be used. When a photoradical curable type active energy ray curable adhesive is used as an ultraviolet curable type, the adhesive contains a radical polymerizable compound and a photopolymerization initiator.

The adhesive coating method is appropriately selected depending on the viscosity of the adhesive and the desired thickness. Examples of the coating method include a reverse coater, a gravure coater (direct, reverse and offset), a bar reverse coater, a roll coater, a die coater, a bar coater, a rod coater and the like. In addition, a method such as a dipping method can be appropriately used for coating.

Further, when an aqueous adhesive or the like is used, the coating of the adhesive is preferably performed so that the thickness of the finally formed adhesive layer is 30 to 300 nm. The thickness of the adhesive layer is more preferably 60 to 150 nm. On the other hand, when an active energy ray-curable adhesive is used, it is preferable that the thickness of the adhesive layer is 0.2 to 20 μm.

When laminating the polarizer 1 and the protective film 2, an easy-adhesive layer can be provided between the protective film and the adhesive layer. The easy-adhesion layer can be formed of, for example, various resins having a polyester skeleton, a polyether skeleton, a polycarbonate skeleton, a polyurethane skeleton, a silicone-based, a polyamide skeleton, a polyimide skeleton, a polyvinyl alcohol skeleton, and the like. These polymer resins may be used alone or in combination of two or more. Further, other additives may be added to form the easy-adhesion layer. Specific examples thereof include stabilizers such as tackifiers, ultraviolet absorbers, antioxidants, and heat-resistant stabilizers.

The easy-adhesive layer is usually provided in advance on the protective film, and the easy-adhesive layer side of the protective film and the polarizer are laminated by the adhesive layer. The easy-adhesive layer is formed by applying a material for forming the easy-adhesive layer onto a protective film by a known technique and drying it. The material for forming the easy-adhesion layer is usually adjusted as a solution diluted to an appropriate concentration in consideration of the thickness after drying, the smoothness of coating, and the like. The thickness of the easy-adhesion layer after drying is preferably 0.01 to 5 μm, more preferably 0.02 to 2 μm, and further preferably 0.05 to 1 μm. A plurality of easy-adhesive layers can be provided, but even in this case, it is preferable that the total thickness of the easy-adhesive layers is within the above range.

The pressure-sensitive adhesive layer is formed from the pressure-sensitive adhesive. Various adhesives can be used as the adhesive, for example, rubber adhesive, acrylic adhesive, silicone adhesive, urethane adhesive, vinyl alkyl ether adhesive, polyvinylpyrrolidone adhesive, poly. Examples include acrylamide-based adhesives and cellulose-based adhesives. A sticky base polymer is selected according to the type of the pressure-sensitive adhesive. Among the above-mentioned pressure-sensitive adhesives, acrylic pressure-sensitive adhesives are preferably used because they are excellent in optical transparency, exhibit appropriate wettability, cohesiveness, and adhesiveness, and are excellent in weather resistance, heat resistance, and the like. ..

The undercoat layer (primer layer) is formed to improve the adhesion between the polarizer 1 and the protective film 2. The material constituting the primer layer is not particularly limited as long as it is a material that exhibits a certain degree of strong adhesion to both the polarizer 1 and the protective film 2. For example, a thermoplastic resin having excellent transparency, thermal stability, stretchability, etc. is used. Examples of the thermoplastic resin include acrylic resins, polyolefin resins, polyester resins, polyvinyl alcohol resins, and mixtures thereof.

(2) Coating liquid The coating liquid contains a resin component or a curable component that can form a transparent resin layer. The transparent resin layer 4 can be formed by applying the coating liquid to the polarizer 1 and solidifying or curing the polarizing element 1.

The form of the coating liquid (hereinafter, also referred to as a forming material) is not particularly limited as long as it is liquid, and may be water-based, water-dispersed, solvent-based, or solvent-free.

It is advantageous that the coating liquid has a low viscosity because it easily penetrates into the damaged portion when the damaged portion is present on the surface of the polarizer 1. The viscosity measured at 25 ° C. is preferably 2000 mPa · s or less, more preferably 1000 mPa · s or less, further preferably 500 mPa · s or less, and particularly preferably 100 mPa · s or less.

The coating liquid is preferably applied to the one-sided protective polarizing film (polarizer side) so that the thickness of the coating film (transparent resin layer 4) after drying is 0.2 μm or more. The thickness of the transparent resin layer 4 is more preferably 0.5 μm or more, and further preferably 0.7 μm or more. On the other hand, if the transparent resin layer 4 becomes too thick, the optical reliability and water resistance deteriorate. Therefore, the thickness of the transparent resin layer 4 is preferably 3 μm or less, more preferably less than 3 μm, and 2 μm or less. It is more preferable to have it.

Various methods are used as the coating method of the coating liquid. Specifically, for example, roll coat, kiss roll coat, gravure coat, reverse coat, roll brush, spray coat, dip roll coat, bar coat, knife coat, air knife coat, curtain coat, lip coat, die coater, etc. Examples include a method such as an extrusion coating method.

Examples of the material for forming the transparent resin layer 4 include polyester resin, polyether resin, polycarbonate resin, polyurethane resin, silicone resin, polyamide resin, polyimide resin, polyvinyl alcohol (PVA) resin, and the like. Examples thereof include acrylic resins and epoxy resins. One of these resin materials can be used alone or in combination of two or more, and among these, one selected from the group consisting of polyurethane resin, polyvinyl alcohol resin, acrylic resin, and epoxy resin. The above is preferable, and polyvinyl alcohol-based resin and acrylic-based resin are more preferable.

As the coating liquid, a coating liquid containing a resin component dissolved or dispersed in water is preferable. The resin component dissolved or dispersed in water refers to a resin dissolved in water or a resin soluble in water dissolved in an aqueous solvent at room temperature (25 ° C.). When the coating liquid is an aqueous system or an aqueous dispersion system, when a damaged portion is present on the surface of the polarizer 1, the surface of the polarizer 1 swells and the coating liquid is blended into the damaged portion, which is advantageous. Is. That is, when the coating liquid is an aqueous system or an aqueous dispersion system, the orientation of the polyvinyl alcohol molecules around the damaged portion constituting the polarizer is partially relaxed, and the boric acid content around the damaged portion is reduced. Therefore, even if the thickness of the transparent resin layer 4 is small (for example, less than 3 μm, preferably less than 2 μm), the expansion of the damaged portion can be effectively suppressed.

Typical examples of resin components that can be dissolved or dispersed in water include polyvinyl alcohol-based resins, poly (meth) acrylic acids, polyacrylamides, methylolated melamine resins, methylolated urea resins, resole-type phenol resins, and polys. Examples thereof include ethylene oxide and carboxymethyl cellulose. This may be used alone or in combination of two or more. As the resin component, polyvinyl alcohol-based resin, poly (meth) acrylic acid, and methylolated melamine are preferably used. In particular, a polyvinyl alcohol-based resin is suitable as the resin component from the viewpoint of adhesion to the polyvinyl alcohol-based resin constituting the polarizer. The case where the polyvinyl alcohol-based resin is used will be described below.

The transparent resin layer 4 is preferably formed from a forming material (coating liquid) containing a polyvinyl alcohol-based resin. The polyvinyl alcohol-based resin forming the transparent resin layer may be the same as or different from the polyvinyl alcohol-based resin contained in the polarizer as long as it is a “polyvinyl alcohol-based resin”.

Examples of the polyvinyl alcohol-based resin include polyvinyl alcohol. Polyvinyl alcohol is obtained by saponification of polyvinyl acetate. Examples of the polyvinyl alcohol-based resin include a saponified product of a copolymer of vinyl acetate and a monomer having copolymerizability. When the monomer having copolymerizability is ethylene, an ethylene-vinyl alcohol copolymer can be obtained. Examples of the copolymerizable monomer include unsaturated carboxylic acids such as (anhydrous) maleic acid, fumaric acid, crotonic acid, itaconic acid, and (meth) acrylic acid, and esters thereof; ethylene, propylene, and the like. α-olefin, (meth) allylsulfonic acid (soda), sodium sulfonic acid (monoalkylmalate), sodium disulfonic acid alkylmalate, N-methylolacrylamide, acrylamidealkylsulfonic acid alkali salt, N-vinylpyrrolidone, N- Examples thereof include vinylpyrrolidone derivatives. These polyvinyl alcohol-based resins may be used alone or in combination of two or more.

For example, a polyvinyl alcohol-based resin having a saponification degree of 95 mol% or more can be used, but from the viewpoint of satisfying moisture heat resistance and water resistance, the saponification degree is preferably 99 mol% or more, and further. Is preferably 99.7 mol% or more. The degree of saponification represents the ratio of units that are actually saponified to vinyl alcohol units among the units that can be converted to vinyl alcohol units by saponification, and the residue is a vinyl ester unit. The degree of saponification can be determined according to JIS-K6726-1994.

For example, a polyvinyl alcohol-based resin having an average degree of polymerization of 500 or more can be used, but from the viewpoint of satisfying moist heat resistance and water resistance, the average degree of polymerization is preferably 1000 or more, more preferably 1500 or more. It is preferable, and more preferably 2000 or more. The average degree of polymerization of the polyvinyl alcohol-based resin is measured according to JIS-K6726.

Further, as the polyvinyl alcohol-based resin, a modified polyvinyl alcohol-based resin having a hydrophilic functional group in the side chain of the polyvinyl alcohol or a copolymer thereof can be used. Examples of the hydrophilic functional group include an acetoacetyl group and a carbonyl group. In addition, modified polyvinyl alcohol obtained by acetalizing, urethanizing, etherifying, grafting, or phosphorifying a polyvinyl alcohol-based resin can be used.

The proportion of the polyvinyl alcohol-based resin in the transparent resin layer 4 or the coating liquid (solid content) is preferably 80% by weight or more, more preferably 90% by weight or more, still more preferably 95% by weight or more.

The coating liquid is prepared as a solution in which the polyvinyl alcohol-based resin is dissolved in a solvent. Examples of the solvent include water, dimethyl sulfoxide, dimethylformamide, dimethylacetamide, amide N-methylpyrrolidone, various glycols, polyhydric alcohols such as trimethylpropane, and amines such as ethylenediamine and diethylenetriamine. These can be used alone or in combination of two or more. Among these, it is preferable to use it as an aqueous solution using water as a solvent. The concentration of the polyvinyl alcohol-based resin in the forming material (for example, an aqueous solution) is not particularly limited, but is preferably 0.1 to 15% by weight in consideration of coatability, standing stability, and the like. More preferably 5-10% by weight.

Additives can be added to the coating liquid (for example, an aqueous solution). Examples of the additive include a plasticizer, a surfactant and the like. Examples of the plasticizer include polyhydric alcohols such as ethylene glycol and glycerin. Examples of the surfactant include nonionic surfactants. Further, a coupling agent such as a silane coupling agent and a titanium coupling agent, various tackifiers, an ultraviolet absorber, an antioxidant, a heat-resistant stabilizer, a stabilizer such as a hydrolysis-resistant stabilizer and the like can be blended.

Next, a case where a coating liquid containing a curable component capable of forming the transparent resin layer is used for forming the transparent resin layer 4 will be described. The curable component can be roughly classified into an active energy ray-curable type such as an electron beam curable type, an ultraviolet curable type, and a visible light curable type, and a thermosetting type. Further, the ultraviolet curable type and the visible light curable type can be classified into a radical polymerization curable type and a cationic polymerization curable type. In the present invention, active energy rays having a wavelength range of 10 nm to less than 380 nm are referred to as ultraviolet rays, and active energy rays having a wavelength range of 380 nm to 800 nm are referred to as visible light. The radical polymerization curable component can be used as a thermosetting curable component.

(Radical polymerization curing type forming material)
Examples of the curable component include radically polymerizable compounds. Examples of the radically polymerizable compound include compounds having a radically polymerizable functional group of a carbon-carbon double bond such as a (meth) acryloyl group and a vinyl group. As these curable components, either a monofunctional radical polymerizable compound or a bifunctional or higher polyfunctional radical polymerizable compound can be used. In addition, these radically polymerizable compounds may be used alone or in combination of two or more. As these radically polymerizable compounds, for example, compounds having a (meth) acryloyl group are suitable. In addition, in this invention, (meth) acryloyl means acryloyl group and / or methacryloyl group, and "(meth)" has the same meaning below.

(Monofunctional radical polymerizable compound)
Examples of the monofunctional radically polymerizable compound include (meth) acrylamide derivatives having a (meth) acrylamide group. The (meth) acrylamide derivative is preferable in terms of ensuring adhesion to the polarizer and in terms of high polymerization rate and excellent productivity. Specific examples of (meth) acrylamide derivatives include N-methyl (meth) acrylamide, N, N-dimethyl (meth) acrylamide, N, N-diethyl (meth) acrylamide, N-isopropyl (meth) acrylamide, and N. N-alkyl group-containing (meth) acrylamide derivatives such as -butyl (meth) acrylamide, N-hexyl (meth) acrylamide; N-methylol (meth) acrylamide, N-hydroxyethyl (meth) acrylamide, N-methylol-N- N-hydroxyalkyl group-containing (meth) acrylamide derivatives such as propane (meth) acrylamide; N-aminoalkyl group-containing (meth) acrylamide derivatives such as aminomethyl (meth) acrylamide and aminoethyl (meth) acrylamide; N-methoxymethyl N-alkoxy group-containing (meth) acrylamide derivatives such as acrylamide and N-ethoxymethylacrylamide; N-mercaptoalkyl group-containing (meth) acrylamide derivatives such as mercaptomethyl (meth) acrylamide and mercaptoethyl (meth) acrylamide; Be done. Examples of the heterocyclic (meth) acrylamide derivative in which the nitrogen atom of the (meth) acrylamide group forms a heterocycle include N-acrylloylmorpholine, N-acrylloylpiperidin, N-methacryloylpiperidin, and N-acrylloylpyrrolidine. And so on.

Among the (meth) acrylamide derivatives, an N-hydroxyalkyl group-containing (meth) acrylamide derivative is preferable, and N-hydroxyethyl (meth) acrylamide is particularly preferable, from the viewpoint of adhesion to a polarizer.

In addition, examples of the monofunctional radically polymerizable compound include various (meth) acrylic acid derivatives having a (meth) acryloyloxy group. Specifically, for example, methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, 2-methyl-2-nitropropyl (meth) acrylate, n-butyl ( Meta) acrylate, isobutyl (meth) acrylate, s-butyl (meth) acrylate, t-butyl (meth) acrylate, n-pentyl (meth) acrylate, t-pentyl (meth) acrylate, 3-pentyl (meth) acrylate, 2,2-Dimethylbutyl (meth) acrylate, n-hexyl (meth) acrylate, cetyl (meth) acrylate, n-octyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, 4-methyl-2-propylpentyl ( Examples thereof include (meth) acrylic acid (1 to 20 carbon atoms) alkyl esters such as meta) acrylate and n-octadecyl (meth) acrylate.

Further, as the (meth) acrylic acid derivative, for example, cycloalkyl (meth) acrylate such as cyclohexyl (meth) acrylate and cyclopentyl (meth) acrylate;
Aralkyl (meth) acrylates such as benzyl (meth) acrylate;
2-Isobornyl (meth) acrylate, 2-norbornylmethyl (meth) acrylate, 5-norbornen-2-yl-methyl (meth) acrylate, 3-methyl-2-norbornylmethyl (meth) acrylate, dicyclo Polycyclic (meth) acrylates such as pentenyl (meth) acrylicate, dicyclopentenyloxyethyl (meth) acrylicate, dicyclopentanyl (meth) acrylicate, etc.;
2-Methoxyethyl (meth) acrylate, 2-ethoxyethyl (meth) acrylate, 2-methoxymethoxyethyl (meth) acrylate, 3-methoxybutyl (meth) acrylate, ethylcarbitol (meth) acrylate, phenoxyethyl (meth) Alkoxy groups such as acrylate and alkylphenoxy polyethylene glycol (meth) acrylate or phenoxy group-containing (meth) acrylate; and the like can be mentioned.

Examples of the (meth) acrylic acid derivative include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, and 4-. Hydroxyalkyl (meth) acrylates such as hydroxybutyl (meth) acrylate, 6-hydroxyhexyl (meth) acrylate, 8-hydroxyoctyl (meth) acrylate, 10-hydroxydecyl (meth) acrylate, 12-hydroxylauryl (meth) acrylate Or, hydroxyl group-containing (meth) acrylates such as [4- (hydroxymethyl) cyclohexyl] methyl acrylate, cyclohexanedimethanol mono (meth) acrylate, and 2-hydroxy-3-phenoxypropyl (meth) acrylate;
Epoxy group-containing (meth) acrylates such as glycidyl (meth) acrylate and 4-hydroxybutyl (meth) acrylate glycidyl ether;
2,2,2-Trifluoroethyl (meth) acrylate, 2,2,2-trifluoroethyl ethyl (meth) acrylate, tetrafluoropropyl (meth) acrylate, hexafluoropropyl (meth) acrylate, octafluoropentyl (meth) ) Halogen-containing (meth) acrylates such as acrylates, heptadecafluorodecyl (meth) acrylates, 3-chloro-2-hydroxypropyl (meth) acrylates;
Alkylaminoalkyl (meth) acrylates such as dimethylaminoethyl (meth) acrylate;
3-Oxetanylmethyl (meth) acrylate, 3-methyl-oxetanylmethyl (meth) acrylate, 3-ethyl-oxetanylmethyl (meth) acrylate, 3-butyl-oxetanylmethyl (meth) acrylate, 3-hexyl-oxetanylmethyl (meth) ) Oxetane group-containing (meth) acrylate such as acrylate;
(Meta) acrylates having a heterocycle such as tetrahydrofurfuryl (meth) acrylate and butyrolactone (meth) acrylate, neopentyl glycol (meth) acrylic acid adduct of hydroxypivalate, p-phenylphenol (meth) acrylate and the like Can be mentioned.

Examples of the monofunctional radically polymerizable compound include carboxyl group-containing monomers such as (meth) acrylic acid, carboxyethyl acrylate, carboxypentyl acrylate, itaconic acid, maleic acid, fumaric acid, crotonic acid, and isocrotonic acid.

Examples of the monofunctional radically polymerizable compound include lactam-based vinyl monomers such as N-vinylpyrrolidone, N-vinyl-ε-caprolactam, and methylvinylpyrrolidone; vinylpyridine, vinylpiperidone, vinylpyrimidine, vinylpiperazin, and vinylpyrazine. Examples thereof include vinyl-based monomers having a nitrogen-containing heterocycle such as vinylpyrrole, vinylimidazole, vinyloxazole, and vinylmorpholin.

Further, as the monofunctional radically polymerizable compound, a radically polymerizable compound having an active methylene group can be used. A radically polymerizable compound having an active methylene group is a compound having an active double bond group such as a (meth) acrylic group at the terminal or in the molecule and having an active methylene group. Examples of the active methylene group include an acetoacetyl group, an alkoxymalonyl group, a cyanoacetyl group and the like. It is preferable that the active methylene group is an acetoacetyl group. Specific examples of the radically polymerizable compound having an active methylene group include 2-acetoacetoxyethyl (meth) acrylate, 2-acetoacetoxypropyl (meth) acrylate, and 2-acetacetoxy-1-methylethyl (meth) acrylate. Etc. Acetacetoxyalkyl (meth) acrylate; 2-ethoxymalonyloxyethyl (meth) acrylate, 2-cyanoacetoxyethyl (meth) acrylate, N- (2-cyanoacetoxyethyl) acrylamide, N- (2-propionylacetoxybutyl) ) Acrylamide, N- (4-acetoacetoxymethylbenzyl) acrylamide, N- (2-acetoacetylaminoethyl) acrylamide and the like. The radically polymerizable compound having an active methylene group is preferably acetoacetoxyalkyl (meth) acrylate.

(Polyfunctional radical polymerizable compound)
Examples of the bifunctional or higher polyfunctional radical polymerizable compound include tripropylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, and 1,9. -Nonandiol di (meth) acrylate, 1,10-decanediol diacrylate, 2-ethyl-2-butylpropanediol di (meth) acrylate, bisphenol A di (meth) acrylate, bisphenol A ethylene oxide adduct di (meth) ) Acrylate, bisphenol A propylene oxide adduct di (meth) acrylate, bisphenol A diglycidyl ether di (meth) acrylate, neopentyl glycol di (meth) acrylate, tricyclodecanedimethanol di (meth) acrylate, cyclic tri Methylolpropanformal (meth) acrylate, dioxane glycol di (meth) acrylate, trimethylpropantri (meth) acrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate , Dipentaerythritol hexa (meth) acrylate, esterified product of (meth) acrylic acid such as EO-modified diglycerin tetra (meth) acrylate and polyhydric alcohol, 9,9-bis [4- (2- (meth) acryloyl) Oxyethoxy) phenyl] fluorene can be mentioned. Specific examples include Aronix M-220, M-306 (manufactured by Toagosei Co., Ltd.), Light Acrylate 1,9ND-A (manufactured by Kyoeisha Chemical Co., Ltd.), Light Acrylate DGE-4A (manufactured by Kyoeisha Chemical Co., Ltd.). ), Light acrylate DCP-A (manufactured by Kyoeisha Chemical Co., Ltd.), SR-531 (manufactured by Sartomer), CD-536 (manufactured by Sartomer) and the like. Further, if necessary, various epoxy (meth) acrylates, urethane (meth) acrylates, polyester (meth) acrylates, various (meth) acrylate-based monomers and the like can be mentioned.

As the radically polymerizable compound, it is preferable to use a monofunctional radically polymerizable compound and a polyfunctional radically polymerizable compound in combination from the viewpoint of achieving both adhesion to a polarizer and optical durability. Usually, it is preferable to use the monofunctional radical polymerizable compound in an amount of 3 to 80% by weight and the polyfunctional radical polymerizable compound in an amount of 20 to 97% by weight based on 100% by weight of the radically polymerizable compound.

(Aspect of radical polymerization curing type forming material)
The radical polymerization curable type forming material can be used as an active energy ray curable type or thermosetting type forming material. When an electron beam or the like is used for the active energy ray, the active energy ray-curable forming material does not need to contain a photopolymerization initiator, but when ultraviolet rays or visible light are used for the active energy ray, it is necessary. It preferably contains a photopolymerization initiator. On the other hand, when the curable component is used as a thermosetting component, the forming material preferably contains a thermopolymerization initiator.

(Photopolymerization initiator)
When a radically polymerizable compound is used, the photopolymerization initiator is appropriately selected by the active energy ray. When curing by ultraviolet rays or visible light, a photopolymerization initiator that cleaves ultraviolet rays or visible light is used. Examples of the photopolymerization initiator include benzophenone compounds such as benzyl, benzophenone, benzoylbenzoic acid, and 3,3'-dimethyl-4-methoxybenzophenone; 4- (2-hydroxyethoxy) phenyl (2-hydroxy-2). Aromatic ketone compounds such as -propyl) ketone, α-hydroxy-α, α'-dimethylacetophenone, 2-methyl-2-hydroxypropiophenone, α-hydroxycyclohexylphenylketone; methoxyacetophenone, 2,2-dimethoxy- Acetphenone compounds such as 2-phenylacetophenone, 2,2-diethoxyacetophenone, 2-methyl-1- [4- (methylthio) -phenyl] -2-morpholinopropane-1, etc .; benzophenone methyl ether, Benzophenone ether compounds such as benzoine ethyl ether, benzoin isopropyl ether, benzoine butyl ether, anisoin methyl ether; aromatic ketone compounds such as benzyl dimethyl ketal; aromatic sulfonyl chlorides such as 2-naphthalene sulfonyl chloride. System compounds; Photoactive oxime compounds such as 1-phenone-1,2-propanedione-2- (O-ethoxycarbonyl) oxime; thioxanson, 2-chlorothioxanson, 2-methylthioxanson, 2,4- Thioxanson compounds such as dimethylthioxanthone, isopropylthioxanthone, 2,4-dichlorothioxanthone, 2,4-diethylthioxanthone, 2,4-diisopropylthioxanthone, dodecylthioxanthone; benzophenone; halogenated Examples thereof include ketones; acylphosphinoxides, and acylphosphonates.

The blending amount of the photopolymerization initiator is 20 parts by weight or less with respect to 100 parts by weight of the total amount of the curable component (radical polymerizable compound). The blending amount of the photopolymerization initiator is preferably 0.01 to 20 parts by weight, more preferably 0.05 to 10 parts by weight, still more preferably 0.1 to 5 parts by weight.

Further, when used in a visible light curable type containing a radically polymerizable compound as a curable component, it is particularly preferable to use a photopolymerization initiator having high sensitivity to light of 380 nm or more. A photopolymerization initiator having high sensitivity to light of 380 nm or more will be described later.

（式中、Ｒ^１及びＲ^２は−Ｈ、−ＣＨ_２ＣＨ_３、−ｉＰｒ又はＣｌを示し、Ｒ^１及びＲ^２は同一又は異なっても良い）
を単独で使用するか、あるいは一般式（１）で表される化合物と後述する３８０ｎｍ以上の光に対して高感度な光重合開始剤とを併用することが好ましい。一般式（１）で表される化合物を使用した場合、３８０ｎｍ以上の光に対して高感度な光重合開始剤を単独で使用した場合に比べて密着性に優れる。一般式（１）で表される化合物の中でも、Ｒ^１及びＲ^２が−ＣＨ_２ＣＨ_３であるジエチルチオキサントンが特に好ましい。当該形成材（塗工液）中の一般式（１）で表される化合物の組成比率は、硬化性成分の全量１００重量部に対して、０．１〜５重量部であることが好ましく、０．５〜４重量部であることがより好ましく、０．９〜３重量部であることがさらに好ましい。 The photopolymerization initiator is a compound represented by the following general formula (1);

(In the formula, R ¹ and R ² indicate -H, -CH ₂ CH ₃ , -iPr or Cl, and R ¹ and R ² may be the same or different).
Is preferably used alone, or a compound represented by the general formula (1) and a photopolymerization initiator having high sensitivity to light of 380 nm or more, which will be described later, are preferably used in combination. When the compound represented by the general formula (1) is used, the adhesion is excellent as compared with the case where a photopolymerization initiator having high sensitivity to light of 380 nm or more is used alone. Among the compounds represented by the general formula (1), diethylthioxanthone in which R ¹ and R ² are −CH ₂ CH ₃ is particularly preferable. The composition ratio of the compound represented by the general formula (1) in the forming material (coating liquid) is preferably 0.1 to 5 parts by weight with respect to 100 parts by weight of the total amount of the curable component. It is more preferably 0.5 to 4 parts by weight, and even more preferably 0.9 to 3 parts by weight.

In addition, it is preferable to add a polymerization initiator as needed. Examples of the polymerization initiator include triethylamine, diethylamine, N-methyldiethanolamine, ethanolamine, 4-dimethylaminobenzoic acid, methyl 4-dimethylaminobenzoate, ethyl 4-dimethylaminobenzoate, isoamyl 4-dimethylaminobenzoate and the like. , And ethyl 4-dimethylaminobenzoate is particularly preferable. When a polymerization initiator is used, the amount of the polymerization initiator added is usually 0 to 5 parts by weight, preferably 0 to 4 parts by weight, and most preferably 0 to 3 parts by weight, based on 100 parts by weight of the total amount of the curable component. is there.

In addition, a known photopolymerization initiator can be used in combination if necessary. Since the protective film having UV absorption ability does not transmit light of 380 nm or less, it is preferable to use a photopolymerization initiator having high sensitivity to light of 380 nm or more as the photopolymerization initiator. Specifically, 2-methyl-1- (4-methylthiophenyl) -2-morpholinopropane-1-one, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1 , 2- (Dimethylamino) -2-[(4-Methylphenyl) Methyl] -1- [4- (4-morpholinyl) phenyl] -1-butanone, 2,4,6-trimethylbenzoyl-diphenyl-phosphine Oxide, bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide, bis (η5-2,4-cyclopentadiene-1-yl) -bis (2,6-difluoro-3- (1H-pyrrole-) 1-yl) -phenyl) titanium and the like can be mentioned.

（式中、Ｒ^３、Ｒ^４及びＲ^５は−Ｈ、−ＣＨ_３、−ＣＨ_２ＣＨ_３、−ｉＰｒ又はＣｌを示し、Ｒ^３、Ｒ^４及びＲ^５は同一又は異なっても良い）
を使用することが好ましい。一般式（２）で表される化合物としては、市販品でもある２−メチル−１−（４−メチルチオフェニル）−２−モルフォリノプロパン−１−オン（商品名：ＩＲＧＡＣＵＲＥ９０７、ＢＡＳＦ社製）が好適に使用可能である。その他、２−ベンジル−２−ジメチルアミノ−１−（４−モルフォリノフェニル）−ブタノン−１（商品名：ＩＲＧＡＣＵＲＥ３６９、ＢＡＳＦ社製）、２−（ジメチルアミノ）−２−［（４−メチルフェニル）メチル］−１−［４−（４−モルホリニル）フェニル］−１−ブタノン（商品名：ＩＲＧＡＣＵＲＥ３７９、ＢＡＳＦ社製）が感度が高いため好ましい。 In particular, as the photopolymerization initiator, in addition to the photopolymerization initiator of the general formula (1), a compound represented by the following general formula (2);

(In the formula, R ³ , R ⁴ and R ⁵ indicate -H, -CH ₃ , -CH ₂ CH ₃ , -iPr or Cl, and R ³ , R ⁴ and R ⁵ may be the same or different).
It is preferable to use. As the compound represented by the general formula (2), 2-methyl-1- (4-methylthiophenyl) -2-morpholinopropane-1-one (trade name: IRGACURE907, manufactured by BASF), which is also a commercially available product, is used. It can be preferably used. In addition, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1 (trade name: IRGACURE369, manufactured by BASF), 2- (dimethylamino) -2-[(4-methylphenyl) ) Methyl] -1- [4- (4-morpholinyl) phenyl] -1-butanone (trade name: IRGACURE379, manufactured by BASF) is preferable because of its high sensitivity.

(Thermal polymerization initiator)
As the thermal polymerization initiator, those which do not initiate polymerization by thermal cleavage are preferable. For example, the thermal polymerization initiator preferably has a 10-hour half-life temperature of 65 ° C. or higher, more preferably 75 to 90 ° C. The half-life is an index showing the decomposition rate of the polymerization initiator, and means the time until the residual amount of the polymerization initiator is halved. The decomposition temperature for obtaining a half-life at an arbitrary temperature and the half-life time at an arbitrary temperature are described in the manufacturer's catalog, etc., for example, "Organic Peroxide Catalog No. 9" of Nippon Oil & Fats Co., Ltd. Edition (May 2003) ”etc.

Examples of the thermal polymerization initiator include lauroyl peroxide (10-hour half-life temperature: 64 ° C.), benzoyl peroxide (10-hour half-life temperature: 73 ° C.), and 1,1-bis (t-butylperoxy) -3. , 3,5-trimethylcyclohexane (10-hour half-life temperature: 90 ° C.), di (2-ethylhexyl) peroxydicarbonate (10-hour half-life temperature: 49 ° C.), di (4-t-butylcyclohexyl) Peroxydicarbonate, di-sec-butylperoxydicarbonate (10-hour half-life temperature: 51 ° C.), t-butylperoxyneodecanoate (10-hour half-life temperature: 48 ° C.), t-hexylperoxy Pivalate, t-butylperoxypivalate, dilauroyl peroxide (10-hour half-life temperature: 64 ° C.), di-n-octanoyl peroxide, 1,1,3,3-tetramethylbutylperoxy-2 -Ethylhexanoate (10-hour half-life temperature: 66 ° C.), di (4-methylbenzoyl) peroxide, dibenzoyl peroxide (10-hour half-life temperature: 73 ° C.), t-butylperoxyisobutyrate (10) Time half-life temperature: 81 ° C.), organic peroxides such as 1,1-di (t-hexylperoxy) cyclohexane.

Examples of the thermal polymerization initiator include 2,2'-azobisisobutyronitrile (10-hour half-life temperature: 67 ° C.) and 2,2'-azobis (2-methylbutyronitrile) (10-hour). Examples thereof include azo compounds such as half-life temperature: 67 ° C.) and 1,1-azobis-cyclohexane-1-carbonitrile (10-hour half-life temperature: 87 ° C.).

The blending amount of the thermal polymerization initiator is 0.01 to 20 parts by weight with respect to 100 parts by weight of the total amount of the curable component (radical polymerizable compound). The blending amount of the thermal polymerization initiator is preferably 0.05 to 10 parts by weight, more preferably 0.1 to 3 parts by weight.

(Cationic polymerization curing type forming material)
Examples of the curable component of the cationic polymerization curable forming material include compounds having an epoxy group and an oxetanyl group. The compound having an epoxy group is not particularly limited as long as it has at least two epoxy groups in the molecule, and various generally known curable epoxy compounds can be used. Preferred epoxy compounds include compounds having at least two epoxy groups and at least one aromatic ring in the molecule (aromatic epoxy compounds) and at least one of them having at least two epoxy groups in the molecule. Examples thereof include a compound (alicyclic epoxy compound) formed between two adjacent carbon atoms constituting an alicyclic ring.

(Photocationic polymerization initiator)
The cationic polymerization curable forming material contains the epoxy compound and the oxetane compound described above as curable components, and since these are both cured by cationic polymerization, a photocationic polymerization initiator is blended. This photocationic polymerization initiator generates a cationic species or Lewis acid by irradiation with active energy rays such as visible light, ultraviolet rays, X-rays, and electron beams, and initiates a polymerization reaction of an epoxy group or an oxetanyl group.

1-2. Solidification or Curing Step The production method of the present invention includes a step of solidifying or curing the obtained coating film. The transparent resin layer 4 can be formed by solidifying or curing the coating film.

When the coating liquid is a coating liquid containing a resin component, the transparent resin layer 4 is formed, and after the coating liquid is applied, the resin component is solidified according to the type. The coating liquid containing the resin component is a solution in which the resin component is dissolved or dispersed in a solvent, and is used as, for example, an aqueous solution, an aqueous dispersion-based dispersion, or a solvent-based solution. The solidification means forming the transparent resin layer 4 by removing the solvent from the coating liquid. For example, when the resin component is a polyvinyl alcohol-based resin, the coating liquid can be used as an aqueous solution and can be solidified by heating (drying) or the like. Further, when the resin component is water-soluble acrylic, solidification can be performed in the same manner.

The drying temperature is not particularly limited and is usually about 60 to 200 ° C., but in the present invention, it is preferably 120 ° C. or lower, more preferably 100 ° C. or lower, from the viewpoint of curl suppression. The drying time is preferably 180 seconds or less, more preferably 120 seconds or less, and even more preferably 60 seconds or less.

On the other hand, in forming the transparent resin layer 4, after applying a coating liquid containing a curable component capable of forming the transparent resin layer, the curable component becomes transparent depending on the type of the curable component. It is cured so that a resin layer can be formed. The coating liquid containing a curable component capable of forming the resin can be used in a solvent-free system as long as the curable component exhibits a coating liquid. Further, as the coating liquid, a solution in which the curable component is dissolved in a solvent can be used. It can also be used as a solution when the curable component presents a coating liquid. The solvent can be appropriately selected depending on the curable component used. For example, when an acrylic monomer forming an acrylic resin is used as the curable component, or when an epoxy monomer forming an epoxy resin is used, the coating liquid containing the curable component is irradiated with active energy rays ( It can be cured by (ultraviolet irradiation) or the like.

The transparent resin layer 4 is formed by the curing type forming material (coating liquid) by applying the curing type forming material to the surface of the polarizer and then curing.

The polarizer 1 may be subjected to a surface modification treatment before the above-mentioned curable forming material is applied. Specific treatments include corona treatment, plasma treatment, and saponification treatment.

The curable type forming material is used as an active energy ray curable type forming material or a thermosetting type forming material. The active energy ray-curable forming material can be used in the form of electron beam-curable type, ultraviolet-curable type, and visible light-curable type. From the viewpoint of productivity, the active energy ray-curable forming material is preferable to the heat-curing type forming material, and the active energy ray-curable forming material is a visible light-curing type forming material. It is preferable from the viewpoint of productivity.

(Active energy ray curing type)
In the active energy ray-curable forming material, after coating the polarizer with the active energy ray-curable forming material, the active energy ray-curable forming material is irradiated with active energy rays (electron beam, ultraviolet rays, visible light, etc.) to obtain the active energy ray-curable forming material. It cures to form the transparent resin layer 4. The irradiation direction of the active energy beam (electron beam, ultraviolet ray, visible light, etc.) can be any appropriate direction. Preferably, the irradiation is performed from the transparent resin layer 4 side.

(Electron beam curing type)
In the electron beam curing type, any appropriate conditions can be adopted as the electron beam irradiation conditions as long as the active energy ray curing type forming material can be cured. For example, in electron beam irradiation, the acceleration voltage is preferably 5 kV to 300 kV, and more preferably 10 kV to 250 kV. If the acceleration voltage is less than 5 kV, the electron beam may not reach the deepest part of the transparent resin layer 4 and the curing may be insufficient. If the acceleration voltage exceeds 300 kV, the penetrating power through the sample is too strong, and the protective film 2 or There is a risk of damaging the polarizer 1. The irradiation dose is 5 to 100 kGy, more preferably 10 to 75 kGy. When the irradiation dose is less than 5 kGy, the transparent resin layer 4 is insufficiently cured, and when it exceeds 100 kGy, the protective film and the polarizer are damaged, the mechanical strength is lowered and yellowing occurs, and a predetermined optical characteristic is obtained. Can't.

The electron beam irradiation is usually performed in an inert gas, but if necessary, it may be performed in the atmosphere or under the condition that a small amount of oxygen is introduced.

(UV curable type, visible light curable type)
In the production method of the present invention, it is preferable to use an active energy ray containing visible light having a wavelength range of 380 nm to 450 nm, particularly an active energy ray having the largest irradiation amount of visible light having a wavelength range of 380 nm to 450 nm. As the active energy ray according to the present invention, a gallium-filled metal halide lamp and an LED light source that emits a wavelength range of 380 to 440 nm are preferable. Alternatively, with ultraviolet rays such as low-pressure mercury lamp, medium-pressure mercury lamp, high-pressure mercury lamp, ultra-high pressure mercury lamp, incandescent lamp, xenon lamp, halogen lamp, carbon arc lamp, metal halide lamp, fluorescent lamp, tungsten lamp, gallium lamp, excima laser or sunlight. A light source containing visible light can be used, and a bandpass filter can be used to block ultraviolet rays having a wavelength shorter than 380 nm.

(Thermosetting type)
On the other hand, in the thermosetting type forming material, by heating, polymerization is started by the thermal polymerization initiator to form a cured product layer. The heating temperature is set according to the thermal polymerization initiator, but is about 60 to 200 ° C., preferably 80 to 150 ° C.

2. 2. Method for producing a polarizing film with an adhesive layer In the method for producing a polarizing film with an adhesive layer of the present invention, an adhesive layer is formed on the transparent resin layer 4 of the one-sided protective polarizing film with a transparent resin layer obtained by the above-mentioned production method. It is characterized by including a step of forming.

(1) Adhesive layer An appropriate adhesive can be used to form the adhesive layer, and the type thereof is not particularly limited. As adhesives, rubber adhesives, acrylic adhesives, silicone adhesives, urethane adhesives, vinyl alkyl ether adhesives, polyvinyl alcohol adhesives, polyvinylpyrrolidone adhesives, polyacrylamide adhesives, Examples include cellulose-based adhesives.

Among these adhesives, those having excellent optical transparency, exhibiting appropriate wettability, cohesiveness, and adhesive properties, and having excellent weather resistance, heat resistance, and the like are preferably used. Acrylic adhesives are preferably used to exhibit such characteristics.

As a method of forming the pressure-sensitive adhesive layer, for example, a method of applying the pressure-sensitive adhesive to a separator or the like that has been peeled off, drying and removing a polymerization solvent or the like to form a pressure-sensitive adhesive layer, and then transferring the pressure-sensitive adhesive layer onto the transparent resin layer 4. Alternatively, it is produced by a method of applying the pressure-sensitive adhesive to the transparent resin layer 4 and drying and removing a polymerization solvent or the like to form a pressure-sensitive adhesive layer on the transparent resin layer 4. When applying the pressure-sensitive adhesive, one or more solvents other than the polymerization solvent may be newly added as appropriate.

A silicone release liner is preferably used as the release-treated separator. In the step of applying the pressure-sensitive adhesive on such a liner and drying it to form the pressure-sensitive adhesive layer, as a method of drying the pressure-sensitive adhesive, an appropriate method can be appropriately adopted depending on the purpose. Preferably, a method of heating and drying the coating film is used. The heating and drying temperature is preferably 40 ° C. to 200 ° C., more preferably 50 ° C. to 180 ° C., and even more preferably 70 ° C. to 170 ° C. By setting the heating temperature in the above range, a pressure-sensitive adhesive having excellent adhesive properties can be obtained.

As the drying time, an appropriate time can be adopted as appropriate. The drying time is preferably 5 seconds to 20 minutes, more preferably 5 seconds to 10 minutes, and even more preferably 10 seconds to 5 minutes.

As a method for forming the pressure-sensitive adhesive layer, various methods are used. Specifically, for example, roll coat, kiss roll coat, gravure coat, reverse coat, roll brush, spray coat, dip roll coat, bar coat, knife coat, air knife coat, curtain coat, lip coat, die coater, etc. Examples include a method such as an extrusion coating method.

The thickness of the pressure-sensitive adhesive layer is not particularly limited, and is, for example, about 1 to 100 μm, preferably 2 to 50 μm, more preferably 2 to 40 μm, and even more preferably 5 to 35 μm.

When the pressure-sensitive adhesive layer is exposed, the pressure-sensitive adhesive layer may be protected by a sheet (separator) that has been peeled off until it is put into practical use.

Examples of the constituent material of the separator include plastic films such as polyethylene, polypropylene, polyethylene terephthalate, and polyester film, porous materials such as paper, cloth, and non-woven fabric, nets, foam sheets, metal foils, and laminates thereof. A thin leaf body or the like can be mentioned, but a plastic film is preferably used because of its excellent surface smoothness.

The plastic film is not particularly limited as long as it can protect the pressure-sensitive adhesive layer, and for example, polyethylene film, polypropylene film, polybutene film, polybutadiene film, polymethylpentene film, polyvinyl chloride film, and vinyl chloride are all used. Examples thereof include a polymer film, a polyethylene terephthalate film, a polybutylene terephthalate film, a polyurethane film, and an ethylene-vinyl acetate copolymer film.

The thickness of the separator is usually about 5 to 200 μm, preferably about 5 to 100 μm. If necessary, the separator may be used for mold release and antifouling treatment with a silicone-based, fluorine-based, long-chain alkyl-based or fatty acid amide-based mold release agent, silica powder, etc., as well as a coating type, a kneading type, and a vapor deposition type. It is also possible to carry out antistatic treatment such as. In particular, the peelability from the pressure-sensitive adhesive layer can be further enhanced by appropriately performing a peeling treatment such as a silicone treatment, a long-chain alkyl treatment, or a fluorine treatment on the surface of the separator.

(2) Surface Protective Film A surface protective film can be provided on the polarizing film of the present invention (including a single protective polarizing film and a polarizing film with an adhesive layer). The surface protective film usually has a base film and an adhesive layer, and protects the polarizing film through the adhesive layer.

As the base film of the surface protective film, a film material having or isotropic is selected from the viewpoint of inspectability, controllability, and the like. Examples of the film material include polyester resins such as polyethylene terephthalate films, cellulose resins, acetate resins, polyether sulfone resins, polycarbonate resins, polyamide resins, polyimide resins, polyolefin resins, and acrylic resins. Examples include transparent polymers such as resins. Among these, polyester-based resins are preferable. The base film can be used as a laminate of one or more film materials, or a stretched product of the film can also be used. The thickness of the base film is generally 500 μm or less, preferably 10 to 200 μm.

As the pressure-sensitive adhesive forming the pressure-sensitive adhesive layer of the surface protective film, a pressure-sensitive adhesive based on a (meth) acrylic polymer, a silicone-based polymer, a polyester, a polyurethane, a polyamide, a polyether, a fluorine-based polymer, a rubber-based polymer, or the like. Can be appropriately selected and used. From the viewpoint of transparency, weather resistance, heat resistance and the like, an acrylic pressure-sensitive adhesive using an acrylic polymer as a base polymer is preferable. The thickness of the pressure-sensitive adhesive layer (dry film thickness) is determined according to the required adhesive strength. It is usually about 1 to 100 μm, preferably 5 to 50 μm.

The surface protective film may be provided with a peeling treatment layer by a low adhesive material such as silicone treatment, long chain alkyl treatment, or fluorine treatment on the opposite surface of the base film to which the pressure-sensitive adhesive layer is provided. ..

3. 3. Manufacturing Method of Optical Laminated Body The manufacturing method of the optical laminated body of the present invention includes a step of bonding the polarizing film with the pressure-sensitive adhesive layer obtained by the manufacturing method to an optical member via the pressure-sensitive adhesive layer without winding it. It is characterized by including.

The single-protective polarizing film with a transparent resin layer obtained by the production method of the present invention and the polarizing film with an adhesive layer using the single-protective polarizing film with the transparent resin layer are said to have curl suppressed. The film can be used as it is in the next step without being wound on a roll or the like, that is, an optical laminate can be manufactured by bonding the film to an optical member via an adhesive layer. When a single-sided protective polarizing film (with a transparent resin layer) is manufactured by a conventional manufacturing method, curling may occur at the edge of the film, and if curling occurs, the curl may occur at the edge of the film during transportation to the next process. It was difficult to use it as it is in the next process because the film was broken due to creases and wrinkles.

The optical member is not particularly limited, but is, for example, a liquid crystal display such as a reflector, a transflective plate, a retardation plate (including a wave plate such as 1/2 or 1/4), and a viewing angle compensation film. One layer or two or more layers that may be used for forming an apparatus or the like can be used. Examples of the optical laminate include a reflective polarizing film or a semi-transmissive polarizing film obtained by laminating a reflecting plate or a semi-transmissive reflecting plate on a polarizing film with an adhesive layer obtained by the production method of the present invention. An elliptically polarizing film or a circularly polarizing film obtained by laminating a retardation plate on a polarizing film with an adhesive layer obtained by the production method of the present invention, or a polarizing film with an adhesive layer obtained by the production method of the present invention. Further, a wide viewing angle polarizing film in which a viewing angle compensating film is laminated, or a polarizing film in which a brightness improving film is further laminated on a polarizing film with an adhesive layer obtained by the production method of the present invention. preferable.

The optical laminate in which the optical member is laminated on the polarizing film with an adhesive layer of the present invention can also be formed by a method of sequentially and separately laminating in the manufacturing process of a liquid crystal display device or the like, but the optical laminate can be formed by laminating in advance. The laminated body has the advantages of excellent quality stability, assembly work, and the like, and can improve the manufacturing process of the liquid crystal display device and the like. When two or more layers of optical members are laminated, an appropriate adhesive means such as an adhesive layer can be used. When adhering the polarizing film with the pressure-sensitive adhesive layer, the optical axes of the polarizing films can be arranged at an appropriate angle according to the desired phase difference characteristics and the like.

The one-sided protective polarizing film with a transparent resin layer, the polarizing film with an adhesive layer, or the optical laminate obtained by the production method of the present invention can be preferably used for forming various devices such as a liquid crystal display device. The liquid crystal display device can be formed according to the conventional method. That is, the liquid crystal display device is generally formed by appropriately assembling a liquid crystal cell, a single protective polarizing film or an optical film with a transparent resin layer, and if necessary, components such as a lighting system, and incorporating a drive circuit. However, the present invention is not particularly limited except that a single-protective polarizing film with a transparent resin layer, a polarizing film with an adhesive layer, or an optical laminate obtained by the production method of the present invention is used. It can be the same as before. As the liquid crystal cell, for example, any type such as IPS type and VA type can be used, but the IPS type is particularly suitable.

Back to a liquid crystal display device or lighting system in which a single protective polarizing film with a transparent resin layer, a polarizing film with an adhesive layer, or an optical laminate obtained by the production method of the present invention is arranged on one side or both sides of a liquid crystal cell. An appropriate liquid crystal display device such as one using a light or a reflecting plate can be formed. In that case, the single protective polarizing film with a transparent resin layer, the polarizing film with an adhesive layer, or the optical laminate obtained by the production method of the present invention can be installed on one side or both sides of the liquid crystal cell. When a single protective polarizing film with a transparent resin layer, a polarizing film with an adhesive layer, or an optical laminate obtained by the production method of the present invention is provided on both sides, they may be the same or different. There may be. Further, when forming the liquid crystal display device, for example, an appropriate component such as a diffuser plate, an anti-glare layer, an antireflection film, a protective plate, a prism array, a lens array sheet, a light diffuser plate, and a backlight is placed in one layer at an appropriate position. Alternatively, two or more layers can be arranged.

Hereinafter, the present invention will be described with reference to examples, but the present invention is not limited to the examples shown below. In addition, each part and% in each example is based on weight. All the conditions left at room temperature unless otherwise specified below are 23 ° C. and 65% R. H. Is.

Production Example 1 (Preparation of Polarizer)
Amorphous isophthalic acid copolymerized polyethylene terephthalate (IPA copolymerized PET) film (thickness: 100 μm) having a water absorption rate of 0.75% and a glass transition temperature (Tg) of 75 ° C. One side of the base material is subjected to corona treatment. Polyvinyl alcohol (degree of polymerization: 4200, degree of saponification: 99.2 mol%) and acetoacetyl-modified PVA (trade name: Gosefimer Z200, degree of polymerization: 1200, degree of acetoacetyl modification: 4.6) on the corona-treated surface. %, Degree of polymerization: 99.0 mol% or more, manufactured by Nippon Synthetic Chemical Industry Co., Ltd., in a ratio of 9: 1 is applied and dried at 25 ° C to form a PVA-based resin layer with a thickness of 11 μm. Then, a laminate was prepared.
The obtained laminate was uniaxially stretched at the free end in the longitudinal direction (longitudinal direction) 2.0 times between rolls having different peripheral speeds in an oven at 120 ° C. (aerial auxiliary stretching treatment).
Next, the laminate was immersed in an insolubilizing bath at a liquid temperature of 30 ° C. (an aqueous boric acid solution obtained by blending 4 parts by weight of boric acid with 100 parts by weight of water) for 30 seconds (insolubilization treatment).
Next, the polarizing plate was immersed in a dyeing bath having a liquid temperature of 30 ° C. while adjusting the iodine concentration and the immersion time so that the polarizing plate had a predetermined transmittance. In this example, 0.2 parts by weight of iodine was mixed with 100 parts by weight of water, and 1.0 part by weight of potassium iodide was mixed and immersed in the obtained iodine aqueous solution for 60 seconds (dyeing treatment). ..
Next, it was immersed in a cross-linked bath at a liquid temperature of 30 ° C. (an aqueous boric acid solution obtained by blending 3 parts by weight of potassium iodide and 3 parts by weight of boric acid with respect to 100 parts by weight of water) for 30 seconds. (Crossing treatment).
Then, the laminate is immersed in an aqueous solution of boric acid having a liquid temperature of 70 ° C. (an aqueous solution obtained by blending 4 parts by weight of boric acid and 5 parts by weight of potassium iodide with respect to 100 parts by weight of water). However, uniaxial stretching was performed between rolls having different peripheral speeds so that the total stretching ratio was 5.5 times in the longitudinal direction (longitudinal direction) (underwater stretching treatment).
Then, the laminate was immersed in a washing bath at a liquid temperature of 30 ° C. (an aqueous solution obtained by blending 4 parts by weight of potassium iodide with 100 parts by weight of water) (cleaning treatment).
From the above, an optical film laminate containing a polarizer having a thickness of 5 μm was obtained.

Production Example 2 (Production of single-sided protective polarizing film)
A (meth) acrylic resin film having a lactone ring structure having a thickness of 40 μm, which had a corona-treated surface, was used as a protective film.

An ultraviolet curable adhesive was prepared by mixing 40 parts by weight of N-hydroxyethylacrylamide (HEAA), 60 parts by weight of acryloyl morpholine (ACMO), and 3 parts by weight of a photoinitiator (trade name: IRGACURE 819, manufactured by BASF). .. This was used as an adhesive for a protective film.

The protective film was attached to the surface of the polarizer of the optical film laminate obtained in Production Example 1 while applying the ultraviolet curable adhesive so that the thickness of the adhesive layer after curing was 1 μm. After that, it was irradiated with ultraviolet rays as active energy rays to cure the adhesive. Ultraviolet irradiation is performed by a gallium-filled metal halide lamp (irradiation device: Fusion UV Systems, Inc. Light HAMMER10, valve: V valve, peak illuminance: 1600 mW / cm ² , cumulative irradiation amount: 1000 / mJ / cm ² (wavelength 380 to 380 to). 440 nm)) was used, and the illuminance of ultraviolet rays was measured using a Solar-Check system manufactured by Solartell. Next, the amorphous PET substrate was peeled off to prepare a single-protective polarizing film (total thickness 46 μm) using a thin polarizing element.
The optical characteristics of the obtained single-protection polarizing film were a simple substance transmittance of 42.8% and a degree of polarization of 99.99%.

<Single transmittance T and polarization degree P>
The single-unit transmittance T and the degree of polarization P of the obtained single-protective polarizing film were measured using a spectral transmittance measuring device with an integrating sphere (Dot-3c, Murakami Color Technology Laboratory Co., Ltd.).
The degree of polarization P is the transmittance (parallel transmittance: Tp) when two identical polarizing films are overlapped so that their transmission axes are parallel, and the two transmission axes are overlapped so as to be orthogonal to each other. It is obtained by applying the combined transmittance (orthogonal transmittance: Tc) to the following equation.
Polarization degree P (%) = {(Tp-Tc) / (Tp + Tc)} 1/2 × 100
Each transmittance is shown by a Y value whose luminosity factor is corrected by a 2 degree field of view (C light source) of JIS Z8701 with 100% of completely polarized light obtained through a Granteller prism polarizer.

Production Example 3 (Production of coating liquid for forming a transparent resin layer)
A polyvinyl alcohol resin having a degree of polymerization of 2500 and a degree of saponification of 99.7 mol% was dissolved in pure water to prepare an aqueous solution (coating solution) having a solid content concentration of 4% by weight and a viscosity of 60 mPa · s (25 ° C.).

<Viscosity measurement>
The viscosity of the coating liquid was measured under the following conditions using a VISCOMETER R85 type viscometer RE85L (manufactured by Toki Sangyo Co., Ltd.).
Measurement temperature: 25 ° C
Rotation speed: 0.5-100 rpm
Cone rotor: 1 ° 34'x R24

Example 1 (Preparation of a single protective polarizing film with a transparent resin layer)
The coating liquid (material for forming the transparent resin layer) obtained in Production Example 3 was applied to the polarizer surface (polarizer surface without the protective film) of the one-sided protective polarizing film obtained in Production Example 2. It was applied using a gravure roll so as to have a thickness of 25 μm. The coating was applied to the entire surface in the width direction of the one-sided protective polarizing film. After the coating, the film was dried with hot air at 95 ° C. for 30 seconds using a floating oven to form a transparent resin layer having a thickness of 1 μm to prepare a single-protective polarizing film with a transparent resin layer.

Example 2, Comparative Example 1
In Example 1, one-sided protection with a transparent resin layer is provided in the same manner as in Example 1, except that the uncoated portions shown in Table 1 are provided from both ends in the width direction of the one-sided protective polarizing film toward the inside. A polarizing film was produced.

The following evaluations were carried out using the single protective polarizing films with a transparent resin layer obtained in Examples and Comparative Examples. The evaluation results are shown in Table 1.

<Curling>
The obtained single-protective polarizing film with a transparent resin layer was placed at 23 ° C. with the transparent resin layer facing upward, and 55% R.I. H. The curl amount of the polarizing plate film immediately after winding was evaluated under the above conditions. For curl measurement, a sample was cut into a rhombus at 45 degrees to the absorption axis and 150 mm so that the coated end was included, and then the sample was set on a horizontal table so that the transparent resin layer side was on top. .. The curl at the coated end of the set sample was measured with a measuring rod and evaluated according to the following evaluation criteria.
A: 10 mm or less B: More than 10 mm and less than 30 mm C: More than 30 mm

In all of the one-sided protective polarizing films with the transparent resin layer of the examples, curl generation was suppressed. On the other hand, in the one-sided protective polarizing film with the transparent resin layer of Comparative Example 1, curl was generated so that the protective film side was convex and the transparent resin layer side was concave.

1 Polarizer 2 Protective film 3 Single protective polarizing film 4 Transparent resin layer 5 Uncoated part 10 Single protective polarizing film with transparent resin layer A Width direction of polarizing film

Claims (8)

A method for producing a single-protective polarizing film having a protective film on only one side of the polarizer, and a single-protective polarizing film with a transparent resin layer having a transparent resin layer provided on the other surface of the polarizer of the single-protective polarizing film. And
The polarizer contains a polyvinyl alcohol-based resin and has a thickness of 10 μm or less.
The transparent resin layer has a thickness of 0.2 μm or more and 3 μm or less.
The transparent resin layer is coated with a coating liquid containing a polyvinyl alcohol-based resin (excluding a coating liquid containing a water-soluble organic titanium compound and / or a water-soluble organic zirconium compound) on the polarizer. It is formed by a step and a step of solidifying the obtained coating film.
In the coating step of the coating liquid, there is an uncoated portion in which the coating liquid is not applied in a region of less than 20 mm from both ends in the width direction of the polarizer, or over the entire width direction of the polarizer. A method for producing a single-protective polarizing film with a transparent resin layer, which comprises applying a coating liquid. The method for producing a single-protective polarizing film with a transparent resin layer according to claim 1, wherein the coating liquid is applied by applying the coating liquid over the entire width direction of the polarizer. The method for producing a single-protective polarizing film with a transparent resin layer according to claim 1 or 2, wherein the width of the polarizer is 1100 to 2000 mm. The method for producing a single-protective polarizing film with a transparent resin layer according to any one of claims 1 to 3, wherein the solidification is performed by drying. The method for producing a single-protective polarizing film with a transparent resin layer according to claim 4, wherein the drying temperature in the drying is 120 ° C. or lower. The method for producing a single-protective polarizing film with a transparent resin layer according to claim 4 or 5, wherein the drying time in the drying is 180 seconds or less. With a pressure-sensitive adhesive layer, which comprises a step of forming a pressure-sensitive adhesive layer on the transparent resin layer of the one-sided protective polarizing film with a transparent resin layer obtained by the production method according to any one of claims 1 to 6. Method for manufacturing polarizing film. A method for producing an optical laminate, which comprises a step of bonding a polarizing film with an adhesive layer obtained by the production method of claim 7 to an optical member via the adhesive layer without winding the polarizing film.

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