KR20180104081A - Method for producing protective polarizing film with transparent resin layer, method for producing polarizing film with pressure-sensitive adhesive layer, method for producing optical laminate - Google Patents

Abstract

The present invention provides a method for producing a transparent resin layer-attached polarizer protective film having a protective polarizing film having a protective film only on one side of a polarizer and a transparent resin layer provided on the other side of the polarizer of the protective polarizing film, Wherein the transparent resin layer comprises a vinyl alcohol resin and has a thickness of 10 mu m or less and the transparent resin layer comprises a step of applying a coating liquid containing a curable component capable of constituting a resin component or a transparent resin layer to the polarizer, Or has an uncoated portion which is not coated with the coating liquid in an area of less than 20 mm inward from both ends of the polarizer in the width direction in the coating step of the coating liquid, And the coating liquid is applied over the entire width direction of the polarizer. According to the production method of the present invention, curling of the transparent resin layer-adhered protective polarizing film can be suppressed.

Description

Method for producing protective polarizing film with transparent resin layer, method for producing polarizing film with pressure-sensitive adhesive layer, method for producing optical laminate

The present invention relates to a method for producing a transparent resin layer-attached polarizing protective film. The present invention also relates to a method for producing a polarizing film with a pressure-sensitive adhesive layer in which a pressure-sensitive adhesive layer is formed on the transparent resin layer of the transparent resin layer-attached polarizing protective film, and a method for producing an optical laminate using the polarizing film with the pressure-sensitive adhesive layer. The transparent resin layer-attached polarizing protective film and the polarizing film with a pressure-sensitive adhesive layer obtained by the production method of the present invention may be used alone or as an optical laminate obtained by laminating the polarizing film with a pressure-sensitive adhesive layer to an image display apparatus such as a liquid crystal display (LCD) .

Liquid crystal display devices are rapidly expanding in the market for watches, mobile phones, PDAs, notebook PCs, monitors for PCs, DVD players, and TVs. A liquid crystal display device is made by visualizing the polarization state due to the switching of liquid crystal, and a polarizer is used from the principle of display.

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

On the other hand, image display devices such as liquid crystal display devices are becoming thinner, and thinner polarizing films are also required. Thus, thinning is also done for polarizers. Further, the thinning can be achieved by using a protective polarizing film in which a protective film is provided only on one side of the polarizer and a protective film is not provided on the other side. Such a polarizing polarizing film is thinner than a polarizing film having a protective film on both sides of the polarizing film because the polarizing film has only one protective film.

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

As a method of producing a polarizing laminated film, a resin layer is formed by providing an uncoated portion not coated with a resin solution in an area of 0.5 cm or more inward from both ends in the width direction of the base film, There has been proposed a method for producing a polarizing laminated film by cutting and removing the unapplied portion, followed by stretching treatment and dyeing treatment (see, for example, Patent Document 3).

Patent Document 1: Japanese Laid-Open Patent Publication No. 2010-009027 Patent Document 2: JP-A-2013-160775 Patent Document 3: Japanese Laid-Open Patent Publication No. 2011-212550

In Patent Documents 1 and 2, a protective layer (transparent resin layer) is formed on the protective polarizing film, but such a polarizing film often curls, and when the obtained polarizing film is transported, Breakage may occur, breakage may occur due to the breakage, or a problem such as wrinkling may occur in stacking on other members.

In the method for producing a polarizing laminated film of Patent Document 3, an unapplied portion is formed at 0.5 cm or more and the unapplied portion is removed to suppress the warping phenomenon of the obtained film. In the method of Patent Document 3, a step of removing an uncoated portion is required, and the manufacturing process is complicated.

Therefore, it is an object of the present invention to provide a method for producing a transparent resin layer-attached piece polarizing film capable of suppressing the generation of curl. It is still another object of the present invention to provide a method for producing a polarizing film with a pressure-sensitive adhesive layer and a method for producing an optical laminate.

As a result of intensive studies, the inventors of the present invention discovered that the above-described problems can be solved by the following production method of a transparent resin layer-attached polarizing protective polarizing film, and have reached the present invention.

That is, the present invention provides a method for producing a transparent resin layer-attached polarizer protective film having a protective polarizing film having a protective film only on one side of a polarizer and a transparent resin layer provided on the other side of the polarizer of the protective polarizing film,

Wherein the polarizer comprises a polyvinyl alcohol-based resin and has a thickness of 10 mu m or less,

Wherein the transparent resin layer is formed by a step of applying a coating liquid containing a curable component that can constitute a resin component or a transparent resin layer to the polarizer, and a step of solidifying or curing the obtained coating film,

In the step of applying the coating liquid, the uncoated portion is not applied in the region of less than 20 mm inward from both ends in the width direction of the polarizer, or the uncoated portion is coated over the entire width direction of the polarizer To a transparent resin layer-attached polarizing protective film.

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

The width of the polarizer is preferably 1,100 to 2,000 mm.

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

The drying temperature is preferably 120 DEG 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 relates to a method for producing a polarizing film with a pressure-sensitive adhesive layer, which comprises a step of forming a pressure-sensitive adhesive layer on a transparent resin layer of a transparent resin layer-attached polarized protective polarizing film obtained by the above production method.

The present invention also provides a process for producing an optical laminate characterized by comprising a step of bonding the polarizing film with a pressure-sensitive adhesive layer obtained by the above-mentioned production method to an optical member via the pressure-sensitive adhesive layer without winding .

The method for producing a transparent resin layer-attached polarized-protective polarizing film of the present invention is characterized in that, when a coating liquid containing a curable component capable of constituting a resin component or a transparent resin layer is applied to a polarizer, It is possible to suppress curling of the obtained transparent resin layer-attached polarizing protective polarizing film by having an uncoated portion not coated with the coating liquid in an area of less than 20 mm each, or by applying a coating liquid over the entire width direction of the polarizer can do. The polarizing film with a pressure-sensitive adhesive layer in which the pressure-sensitive adhesive layer is provided on the transparent resin layer of the transparent resin layer-attached polarizing protective film is also curled. Therefore, the transparent resin layer-attached polarized protective film and the polarized film with a pressure-sensitive adhesive layer obtained by the production method of the present invention can be laminated on an optical member used for an image display apparatus or the like without being taken up on a roll after production.

Fig. 1 is an example of a schematic sectional view of a transparent resin layer-attached protective polarizing film obtained by the production method of the present invention.
Fig. 2 is an example of a schematic sectional view of the transparent resin layer-attached polarizing protective film obtained by the production method of the present invention.

1. Method for producing polarizer protective film with transparent resin layer

The method for producing a transparent resin layer-attached polarizing protective film of the present invention comprises:

It is possible to produce a transparent resin layer-attached piece polarizing film having a protective polarizing film having only a protective film on one side of the polarizer and a transparent resin layer provided on the other side of the polarizer of the protective polarizing film,

Wherein the polarizer comprises a polyvinyl alcohol-based resin and has a thickness of 10 mu m or less,

Wherein the transparent resin layer is formed by a step of applying a coating liquid containing a curable component that can constitute a resin component or a transparent resin layer to the polarizer and a step of solidifying or curing the obtained coating film,

In the step of applying the coating liquid, the uncoated portion is not applied in the region of less than 20 mm inward from both ends in the width direction of the polarizer, or the uncoated portion is coated over the entire width direction of the polarizer Is applied.

The transparent resin layer-attached polarizing protective film obtained by the production method of the present invention will be described with reference to Figs. 1 and 2. Fig. However, the present invention is not limited to these drawings.

The polarizing protective polarizing film (3) used in the present invention has the protective film (2) on only 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, a pressure-sensitive adhesive layer, and an undercoat layer (primer layer). The manufacturing method of the present invention is characterized in that a transparent resin layer 4 is formed on the surface (other surface) of the polarizer 1 of the polarizing protective film 3 having no protective film 2 to form a transparent resin layer- To thereby produce a film (10).

The formation of the transparent resin layer 4 is carried out by applying to the polarizer 1 a coating liquid containing a curable component capable of constituting a resin component or the transparent resin layer 4 and a step of curing or hardening the obtained coating film . As shown in Fig. 1, in the step of applying the coating liquid, uncoated (not coated) the coating liquid in an area of 20 mm inward from both ends in the width direction (direction A in the drawing) of the polarizer 1 (Not having an uncoated portion) over the whole width direction of the polarizer 1, as shown in Fig. 2, as shown in Fig. The application of such a coating can suppress curling of the resulting transparent resin layer-attached polarizing protective film 10 and can be applied to an optical member used in an image display apparatus or the like without being taken up on a roll after production. Here, the width direction of the polarizer 1 means a direction perpendicular to the stretching direction (transport direction) of the polarizer 1.

When the uncoated portion is provided in the coating, it is preferable that the uncoated portion is an area of less than 20 mm inward from both ends in the width direction of the polarizer, and is preferably an area of 15 mm or less, More preferable. It is preferable in that the occurrence of curling of the transparent resin layer-attached polarizing protective film obtained by bringing the unapplied portion within the above range can be suppressed. The lower limit value of the area of the uncoated portion is not particularly limited and is preferably as small as possible. It is particularly preferable that the coating liquid is applied over the entire width direction of the polarizer, that is, it has no uncoated portion.

In the case where the uncoated portion is provided in the coating, it is preferable that the uncoated portion is an area of 5% or less with respect to the width of the polarizer from both ends in the width direction of the polarizer, , More preferably less than 2% of the width of the polarizer, and more preferably less than 2% of the width of the polarizer. It is preferable in that the occurrence of curling of the transparent resin layer-attached polarizing protective film obtained by bringing the unapplied portion within the above range can be suppressed. The lower limit value of the area of the uncoated portion is not particularly limited and is preferably as small as possible. A method of applying the coating liquid over the entire width direction of the polarizer, that is, a method of applying 0% Is not particularly preferred).

Each step of the production method of the present invention will be described below.

1-1. Coating solution application process

The production method of the present invention is characterized in that the protective film (2) of the polarizer (1) of the polarizing protective polarizing film (3) comprises a curing component capable of constituting a resin component or a transparent resin layer on the surface And a step of applying the coating solution. The application method is as described above.

(1) Protective polarizing film

(1-1) Polarizer

In the present invention, a polarizer having a thickness of 10 m or less is used. The thickness of the polarizer is preferably 8 占 퐉 or less, more preferably 7 占 퐉 or less, and further preferably 6 占 퐉 or less. On the other hand, the thickness of the polarizer is preferably 2 탆 or more, more preferably 3 탆 or more. Such thin polarizers are excellent in durability against thermal shock because of small thickness variation, excellent visibility, and small dimensional change.

The polarizer 1 is made of a polyvinyl alcohol-based resin. Examples of the polarizer 1 include a hydrophilic polymer film such as a polyvinyl alcohol film, a partially formalized polyvinyl alcohol film and a partially saponified ethylene / vinyl acetate copolymer film, Materials obtained by uniaxial stretching by adsorbing a substance, and polyene oriented films such as dehydrated polyvinyl alcohol and dehydrochlorinated polyvinyl chloride. Among them, a polyvinyl alcohol film and a polarizer made of a dichroic material such as iodine are preferable.

The polarizer obtained by dying a polyvinyl alcohol film with iodine and uniaxially stretching can be produced by, for example, dying polyvinyl alcohol in an aqueous solution of iodine and stretching it to 3 to 7 times its original length. If necessary, it may contain boric acid, zinc sulfate, zinc chloride or the like, or it may be immersed in an aqueous solution of potassium iodide or the like. If necessary, the polyvinyl alcohol film may be dipped in water and washed with water before dyeing. The polyvinyl alcohol film is washed with water to clean the surface of the polyvinyl alcohol film and to prevent unevenness such as uneven dyeing by swelling the polyvinyl alcohol film. The stretching may be performed after dyeing with iodine, stretching while dyeing, or stretching and dyeing with iodine. It can be stretched 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 viewpoints of stretch stability and optical durability. The content of boric acid contained in the polarizer 1 is preferably 25% by weight or less, more preferably 20% by weight or less, and more preferably 18% by weight or less based on the total amount of the polarizer from the viewpoints of prevention of penetration cracks, % Or less, and particularly preferably 16 wt% or less. When the content of boric acid contained in the polarizer 1 exceeds 20% by weight, the shrinkage stress of the polarizer 1 is increased even when the thickness of the polarizer 1 is controlled to 10 탆 or less, It is not preferable. On the other hand, from the viewpoints of the 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.

Examples of the thin polarizer include a polarizer disclosed in Japanese Patent No. 4751486, Japanese Patent No. 4751481, Japanese Patent No. 4815544, Japanese Patent No. 5048120, International Publication No. 2014/077599, International A thin polarizer disclosed in, for example, pamphlet of Publication No. 2014/077636, or a thin polarizer obtained from the production method described in these.

The polarizer 1 is preferably such that the optical characteristics represented by the simple transmittance T and the degree of polarization P ^{satisfy the} following equation: P> - (10 ^0.929T-42.4 -1) x 100 (where T <42.3) 99.9 (however, T? 42.3). The polarizer configured to satisfy the above condition uniquely has the performance required as a liquid crystal TV display using a large display element. Specifically, it has a contrast ratio of 1000: 1 or more and a maximum luminance of 500 cd / m ² or more. For another application, for example, it is bonded to the visible side of the organic EL display device.

As the thin polarizer, in view of being capable of stretching at a high magnification and improving polarization performance even in a process including a step of stretching in a laminate state and a step of dyeing, Japanese Patent No. 4751486, Japanese Patent No. 4751481 In the aqueous solution of boric acid as described in the specification of Japanese Patent No. 4815544, and in particular, it is preferably obtained by the method described in Japanese Patent No. 4751481 or Japanese Patent No. 4815544 In a boric acid aqueous solution containing boric acid in an aqueous solution of boric acid. These thin polarizers can be obtained by a manufacturing method including a step of stretching a polyvinyl alcohol-based resin layer and a lead resin base material into a laminate state and a step of dyeing. With this production method, even if the polyvinyl alcohol-based resin layer is thin, it is supported on the resin base material for drawing, so that it can be stretched without any problem such as breakage by stretching.

(1-2) Protective film

The material constituting the protective film (2) is preferably excellent in transparency, mechanical strength, thermal stability, moisture barrier property, isotropy and the like. Examples thereof include polyester polymers such as polyethylene terephthalate and polyethylene naphthalate, cellulose polymers such as diacetylcellulose and triacetylcellulose, acrylic polymers such as polymethylmethacrylate, polystyrene and acrylonitrile-styrene copolymer (AS Resin), and polycarbonate-based polymers. Examples of the polyolefin-based polymer include polyolefin-based polymers such as polyethylene, polypropylene, cyclo- or norbornene-based polyolefins, ethylene-propylene copolymers, vinyl chloride-based polymers, amide-based polymers such as nylon and aromatic polyamide, imide- Polymer, polyether sulfone polymer, polyether ether ketone polymer, polyphenylene sulfide polymer, vinyl alcohol polymer, vinylidene chloride polymer, vinyl butyral polymer, arylate polymer, polyoxymethylene polymer, epoxy Based polymer or a mixture of the above-described polymers may be mentioned as an example of the polymer forming the protective film.

The protective film (2) may contain one or more optional additives. Examples of additives include ultraviolet absorbers, antioxidants, lubricants, plasticizers, mold release agents, coloring inhibitors, flame retardants, nucleating agents, antistatic agents, pigments and colorants. The content of the thermoplastic resin in the protective film is preferably 50 to 100 mass%, more preferably 50 to 99 mass%, still more preferably 60 to 98 mass%, and particularly preferably 70 to 97 mass%. When the content of the thermoplastic resin in the protective film is less than 50% by mass, there is a possibility that the high transparency inherently possessed by the thermoplastic resin may not be sufficiently exhibited.

As the protective film 2, a retardation film, a brightness enhancement film, a diffusion film, or the like can be used. Examples of the retardation film include retardation films having a front retardation of 40 nm or more and / or a thickness retardation of 80 nm or more. The front retardation is usually in the range of 40 to 200 nm, and the retardation in the thickness direction 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 it can be thinned.

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

Though the thickness of the protective film 2 can be appropriately determined, it is generally preferably from 3 to 200 占 퐉 in view of workability such as strength and handling property, thin layer property, Mu] m. In particular, the thickness of the protective film (when a film is formed in advance) is preferably 10 to 60 占 퐉, more preferably 10 to 50 占 퐉, from the viewpoint of transportability. On the other hand, the thickness of the protective film (when formed by coating or curing) is preferably 3 to 25 占 퐉, more preferably 3 to 20 占 퐉, from the viewpoint of transportability. The protective film may be used in plural or plural layers.

The surface of the protective film 2 on which the polarizer 1 is not adhered may be provided with a functional layer such as a hard coat layer, an antireflection layer, a sticking prevention layer, a diffusion layer, or an antiglare layer. The functional layers such as the hard coat layer, the antireflection layer, the anti-sticking layer, the diffusion layer, and the anti-glare layer may be provided on the protective film 2 itself or separately from the protective film It can also be installed.

(1-3)

The protective film 2 and the polarizer 1 can be laminated via an intervening layer such as an adhesive layer, a pressure-sensitive adhesive layer, and an undercoat layer (primer layer). At this time, it is preferable to stack the both without air gap by the interposition layer. The intervening layers of the polarizer 1 and the protective film 2 are not shown in the figure.

The adhesive layer is formed by an adhesive. The kind of the adhesive is not particularly limited, and various ones can be used. There are no particular restrictions on the adhesive layer as long as it is optically transparent, and various types of adhesives such as an aqueous system, a solvent system, a hot melt system, and an active energy ray curable system can be used. Do.

Examples of the water-based adhesive include an isocyanate-based adhesive, a polyvinyl alcohol-based adhesive, a gelatin-based adhesive, a vinyl-based latex system, and a water-based polyester. 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 solids.

The active energy ray curable adhesive is an adhesive which is cured by an active energy ray such as electron beam, ultraviolet ray (radical curing type, cation curing type) or the like, and can be used, for example, as an electron beam curable type or an ultraviolet curable type. As the active energy ray curable adhesive, for example, a photo-radical curable adhesive may be used. When the photo-radical curing type active energy ray-curable adhesive is used as an ultraviolet curing type adhesive, the adhesive contains a radical polymerizing compound and a photopolymerization initiator.

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

When an aqueous adhesive or the like is used, it is preferable 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, the thickness of the adhesive layer is preferably 0.2 to 20 m.

Further, in the lamination of the polarizer 1 and the protective film 2, an easy adhesive layer can be provided between the protective film and the adhesive layer. This adhesive layer can be formed by various resins having a polyester skeleton, a polyether skeleton, a polycarbonate skeleton, a polyurethane skeleton, a silicone type, a polyamide skeleton, a polyimide skeleton, and a polyvinyl alcohol skeleton, for example. These polymer resins may be used singly or in combination of two or more. Other additives may be added to form the adhesive layer. Specific examples include stabilizers such as a tackifier, an ultraviolet absorber, an antioxidant, and a heat-resistant stabilizer.

This adhesive layer is usually provided in advance on a protective film, and the adhesive layer side of the protective film and the polarizer are laminated by an adhesive layer. This adhesive layer is formed by coating the forming material of the adhesive layer on a protective film by a known technique and drying it. The material for forming the adhesive layer is a solution diluted to an appropriate concentration in consideration of the thickness after drying, the original activity of the coating, and the like, and is usually adjusted. The thickness of the adhesive layer after drying is preferably 0.01 to 5 占 퐉, more preferably 0.02 to 2 占 퐉, and still more preferably 0.05 to 1 占 퐉. Although this adhesive layer can be provided in a plurality of layers, in this case also, the total thickness of the adhesive layer is preferably in the above range.

The pressure-sensitive adhesive layer is formed of a pressure-sensitive adhesive. As the pressure sensitive adhesive, various pressure sensitive adhesives can be used. Examples of the pressure sensitive adhesive include rubber pressure sensitive adhesives, acrylic pressure sensitive adhesives, silicone pressure sensitive adhesives, urethane pressure sensitive adhesives, vinyl alkyl ether pressure sensitive adhesives, polyvinyl pyrrolidone pressure sensitive adhesives, polyacrylamide pressure sensitive adhesives, and cellulosic pressure sensitive adhesives have. Depending on the type of the pressure-sensitive adhesive, a tacky base polymer is selected. Among these pressure-sensitive adhesives, acrylic pressure-sensitive adhesives are preferably used because they have excellent optical transparency, exhibit appropriate wettability, cohesiveness and adhesive properties such as adhesiveness, and are excellent in weather resistance and heat resistance.

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 can exert a strong adhesion to the polarizer 1 and the protective film 2 to some extent. Thermoplastic resins excellent in transparency, thermal stability, stretchability, and the like are used. Examples of the thermoplastic resin include an acrylic resin, a polyolefin resin, a polyester resin, a polyvinyl alcohol resin, or a mixture thereof.

(2) Coating solution

The coating liquid contains a resin component or a curable component that can constitute 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 coating liquid.

The form of the coating liquid (hereinafter also referred to as a forming material) is not particularly limited as long as it exhibits a liquid phase, and may be any of an aqueous system, a water dispersion system, a solvent system and a solventless system.

The lower viscosity of the coating liquid is advantageous because it is easy to penetrate the damaged portion when the damaged portion exists on the surface of the polarizer 1. The viscosity is preferably not more than 2000 mPa · s, more preferably not more than 1000 mPa · s, even more preferably not more than 500 mPa · s, and most preferably not more than 100 mPa · s.

The application of the coating liquid to the protective polarizing film (polarizer side) is preferably carried out such that the thickness of the coated film (transparent resin layer 4) after drying is 0.2 탆 or more. The thickness of the transparent resin layer 4 is more preferably 0.5 탆 or more, and more preferably 0.7 탆 or more. On the other hand, when the transparent resin layer 4 is too thick, the optical reliability and water resistance are lowered. Therefore, the thickness of the transparent resin layer 4 is preferably 3 m or less, more preferably less than 3 m, Do.

As the coating method of the coating liquid, various methods are used. Concretely, for example, extrusion by a roll coater, a kiss roll coat, a gravure coat, a reverse coat, a roll brush, a spray coat, a dip roll coat, a bar coat, a knife coat, an air knife coat, a curtain coat, a lip coat, Coating method and the like.

As a material for forming the transparent resin layer 4, for example, a polyester resin, a polyether resin, a polycarbonate resin, a polyurethane resin, a silicone resin, a polyamide resin, a polyimide resin, a polyvinyl alcohol (PVA) based resin, an acrylic based resin, and an epoxy based resin. These resin materials may be used singly or in combination of two or more. Among them, at least one selected from the group consisting of a polyurethane resin, a polyvinyl alcohol resin, an acrylic resin and an epoxy resin is preferable , A polyvinyl alcohol resin, and an acrylic resin are more preferable.

The coating solution is preferably a coating solution containing a resin component dissolved or dispersed in water. A resin component dissolved or dispersed in water means a resin dissolved in water or a resin soluble in water at room temperature (25 캜) dissolved in an aqueous solvent. If the coating liquid is an aqueous or water dispersion system, the surface of the polarizer 1 swells when the damaged portion is present on the surface of the polarizer 1, which is advantageous because the coating liquid permeates the damaged portion. That is, if the coating liquid is an aqueous or aqueous dispersion system, the orientation property of the polyvinyl alcohol molecules around the damaged portion constituting the polarizer can be partially alleviated and the content of boric acid around the damaged portion can be reduced. Therefore, 4) (for example, less than 3 mu m, preferably 2 mu m or less) can be effectively suppressed.

Representative examples of resin components that can be dissolved or dispersed in water include polyvinyl alcohol resin, poly (meth) acrylic acid, polyacrylamide, methylolmelamine resin, methylol urea resin, resol type phenol resin, polyethylene Oxide, carboxymethylcellulose, and the like. These may be used alone or in combination. As the resin component, polyvinyl alcohol resin, poly (meth) acrylic acid and methylol melamine are preferably used. Particularly, from the viewpoint of adhesion with the polyvinyl alcohol-based resin constituting the polarizer, the resin component is preferably a polyvinyl alcohol-based resin. Hereinafter, the case of using a polyvinyl alcohol-based resin will be described.

The transparent resin layer 4 is preferably formed of 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 &quot; polyvinyl alcohol-based resin &quot;.

Examples of the polyvinyl alcohol-based resin include polyvinyl alcohol. Polyvinyl alcohol is obtained by saponifying polyvinyl acetate. As the polyvinyl alcohol-based resin, a saponification product of a copolymer of vinyl acetate and a monomer having a copolymerization may be mentioned. When the monomer having the copolymerization is ethylene, an ethylene-vinyl alcohol copolymer is obtained. Examples of the monomer having the above-mentioned copolymerization include unsaturated carboxylic acids such as (anhydride) maleic acid, fumaric acid, crotonic acid, itaconic acid and (meth) acrylic acid and esters thereof; (Meth) allyl sulfonic acid (soda), soda sulfonate (monoalkyl maleate), disulfonic acid soda alkyl malate, N-methylol acrylamide, acrylamide alkylsulfonic acid alkali salt, N- Vinyl pyrrolidone, N-vinyl pyrrolidone derivatives, and the like. These polyvinyl alcohol resins may be used singly or in combination of two or more.

The degree of saponification of the polyvinyl alcohol-based resin may be 95 mol% or more, for example. From the viewpoint of satisfying the moisture resistance and water resistance, the saponification degree is preferably 99 mol% or more, and more preferably 99.7 mol% or more. The degree of saponification represents the proportion of units actually saponified as vinyl alcohol units among the units that can be converted into vinyl alcohol units by saponification, and the residues are vinyl ester units. The degree of saponification can be obtained according to JIS-K6726-1994.

The average degree of polymerization of the polyvinyl alcohol-based resin may be 500 or more, for example, but the average degree of polymerization is preferably 1,000 or more, more preferably 1,500 or more, and still more preferably 2,000 or more, from the viewpoint of satisfying the wet heat resistance and water resistance . The average polymerization degree of the polyvinyl alcohol-based resin is measured according to JIS-K6726.

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 the 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 subjecting a polyvinyl alcohol resin to acetalization, urethanization, etherification, grafting, phosphoric esterification, or the like 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, and still more preferably 95% by weight or more.

The coating solution is prepared by dissolving the polyvinyl alcohol-based resin in a solvent. Examples of the solvent include water, dimethylsulfoxide, dimethylformamide, dimethylacetamide, amide N-methylpyrrolidone, various glycols, polyhydric alcohols such as trimethylolpropane, amines such as ethylenediamine and diethylenetriamine, . These may be used alone or in combination of two or more. Among them, 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, more preferably 0.5 to 10% by weight in view of coatability, desirable.

An additive may be added to the coating liquid (for example, an aqueous solution). Examples of the additive include plasticizers, surfactants, and the like. Examples of the plasticizer include polyhydric alcohols such as ethylene glycol and glycerin. Examples of the surfactant include nonionic surfactants. In addition, a coupling agent such as a silane coupling agent and a titanium coupling agent, various tackifiers, ultraviolet absorbers, antioxidants, heat stabilizers, and stabilizers such as an antioxidant stabilizer may be added.

Next, a description will be given of the case of using a coating solution containing a curable component that can constitute the transparent resin layer in the formation of the transparent resin layer (4). The curable component can be broadly divided into active energy radiation curable type such as electron beam curable type, ultraviolet ray curable type and visible light curable type and thermosetting type. Furthermore, ultraviolet curing type and visible light curing type can be classified into a radical polymerization curing type and a cationic polymerization curing type. In the present invention, an active energy ray in a wavelength range of 10 nm to less than 380 nm is referred to as an ultraviolet ray, and an active energy ray in a wavelength range of 380 nm to 800 nm is referred to as a visible ray. The radically curing curable component can be used as a thermosetting curable component.

(Radical polymerization curing type forming material)

The curable component includes, for example, a radically polymerizable compound. The radical polymerizing compound includes a compound having a radically polymerizable functional group of a carbon-carbon double bond such as a (meth) acryloyl group or a vinyl group. These curable components may be any of monofunctional radically polymerizable compounds or polyfunctional radically polymerizable compounds having a bifunctional or higher functionality. These radically polymerizable compounds may be used singly or in combination of two or more. As the radically polymerizable compound, for example, a compound having a (meth) acryloyl group is preferable. In the present invention, (meth) acryloyl means acryloyl group and / or methacryloyl group, and &quot; (meth) &quot;

(Monofunctional radically polymerizable compound)

Examples of the monofunctional radically polymerizable compound include (meth) acrylamide derivatives having (meth) acrylamide groups. (Meth) acrylamide derivatives are preferable because they ensure adhesion with a polarizer and also have a high polymerization rate and excellent productivity. Specific examples of the (meth) acrylamide derivative include N, N-dimethyl (meth) acrylamide, N, N-diethyl (meth) acrylamide, N-isopropyl Alkyl (meth) acrylamide derivatives such as N-butyl (meth) acrylamide, N-butyl (meth) acrylamide and N-hexyl (Meth) acrylamide derivatives containing N-hydroxyalkyl groups such as N-methylol (meth) acrylamide, N-hydroxyethyl (meth) acrylamide and N-methylol-N-propane (meth) acrylamide; (Meth) acrylamide derivatives containing N-aminoalkyl groups such as aminomethyl (meth) acrylamide and aminoethyl (meth) acrylamide; N-alkoxy group-containing (meth) acrylamide derivatives such as N-methoxymethyl acrylamide and N-ethoxymethylacrylamide; (Meth) acrylamide derivatives containing N-mercaptoalkyl groups such as mercaptomethyl (meth) acrylamide and mercaptoethyl (meth) acrylamide. Examples of the heterocyclic ring-containing (meth) acrylamide derivatives in which the nitrogen atom of the (meth) acrylamide group forms a heterocycle include N-acryloylmorpholine, N-acryloylpiperidine, N-methacryl Naphthylpyridine, N-acryloylpyrrolidine, and the like.

Of these (meth) acrylamide derivatives, N-hydroxyalkyl group-containing (meth) acrylamide derivatives are preferable from the viewpoint of adhesion with polarizers, and N-hydroxyethyl (meth) acrylamide is particularly preferable.

Examples of the monofunctional radically polymerizable compound include various (meth) acrylic acid derivatives having a (meth) acryloyloxy group. Specific examples thereof include monofunctional acrylates such as methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, butyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, (Meth) acrylate, 2-ethylhexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, (Meth) acrylic acid (having 1 to 20 carbon atoms) alkyl esters such as ethylhexyl (meth) acrylate, 4-methyl-2-propylpentyl (meth) acrylate and n-octadecyl have.

Examples of the (meth) acrylic acid derivatives include cycloalkyl (meth) acrylates such as cyclohexyl (meth) acrylate and cyclopentyl (meth) acrylate;

Aralkyl (meth) acrylates such as benzyl (meth) acrylate;

(Meth) acrylate, 3-methyl-2-norbornylmethyl (meth) acrylate, 2-norbornylmethyl (meth) Polycyclic (meth) acrylates such as dicyclopentenyl (meth) acrylate, dicyclopentenyloxyethyl (meth) acrylate and dicyclopentanyl (meth) acrylate;

(Meth) acrylates such as 2-methoxyethyl (meth) acrylate, 2-ethoxyethyl (meth) acrylate, 2- methoxymethoxyethyl Alkoxy groups such as phenoxyethyl (meth) acrylate, phenoxyethyl (meth) acrylate and alkylphenoxypolyethylene glycol (meth) acrylate, and phenoxy group-containing (meth) acrylates.

Examples of the (meth) acrylic acid derivatives include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (Meth) acrylate, 10-hydroxydecyl (meth) acrylate, 12-hydroxybutyl (meth) acrylate, (Meth) acrylate such as hydroxyaryl (meth) acrylate, a hydroxyalkyl (meth) acrylate such as [4- (hydroxymethyl) cyclohexyl] methyl acrylate, cyclohexanedimethanol mono (Meth) acrylate such as hydroxy-3-phenoxypropyl (meth) acrylate;

(Meth) acrylates such as glycidyl (meth) acrylate and 4-hydroxybutyl (meth) acrylate glycidyl ether;

2,2,2-trifluoroethyl (meth) acrylate, tetrafluoropropyl (meth) acrylate, hexafluoropropyl (meth) acrylate, Halogen-containing (meth) acrylates such as acrylate, octafluoropentyl (meth) acrylate, heptadecafluorodecyl (meth) acrylate and 3-chloro-2-hydroxypropyl (meth) acrylate;

Alkylaminoalkyl (meth) acrylates such as dimethylaminoethyl (meth) acrylate;

(Meth) acrylate, 3-methyl-oxetanylmethyl (meth) acrylate, 3-methyl-oxetanylmethyl (Meth) acrylate, 3-hexyl-oxetanylmethyl (meth) acrylate and other oxetane group-containing (meth) acrylates;

(Meth) acrylate or hydroxypivalic acid neopentyl glycol (meth) acrylic acid adduct having a heterocycle such as tetrahydrofurfuryl (meth) acrylate or butyrolactone (meth) acrylate, p-phenylphenol ) Acrylate, and the like.

Examples of monofunctional radically polymerizable compounds 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-epsilon -caprolactam and methylvinylpyrrolidone; Vinyl monomers having a nitrogen-containing heterocycle such as vinylpyridine, vinylpiperidone, vinylpyrimidine, vinylpiperazine, vinylpyrazine, vinylpyrrole, vinylimidazole, vinyloxazole and vinylmorpholine.

As the monofunctional radically polymerizable compound, a radically polymerizable compound having an active methylene group can be used. The radical polymerizable compound having an active methylene group is a compound having an active double bond group such as a (meth) acryl 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 alkoxymonyl group, and a cyanoacetyl group. The active methylene group is preferably an acetoacetyl group. Specific examples of the radically polymerizable compound having an active methylene group include 2-acetoacetoxyethyl (meth) acrylate, 2-acetoacetoxypropyl (meth) acrylate, 2-acetoacetoxy- Acetoacetoxyalkyl (meth) acrylates such as methacrylate; 2-cyanoacetoxyethyl (meth) acrylate, N- (2-cyanoacetoxyethyl) acrylamide, N- (2-propionylacetoxy Butyl) 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 radically polymerizable compound)

Examples of the polyfunctional radically polymerizable compounds having a bifunctional or higher functionality include tripropylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, 1,6-hexanediol di (meth) (Meth) acrylate, bisphenol A di (meth) acrylate, bisphenol A ethylene oxide, 1,6-hexanediol di (meth) acrylate, (Meth) acrylate, adipate di (meth) acrylate, bisphenol A propylene oxide adduct di (meth) acrylate, bisphenol A diglycidyl ether di (meth) acrylate, neopentyl glycol di (Meth) acrylates such as methanol di (meth) acrylate, cyclic trimethylolpropane formal (meth) acrylate, dioxane glycol di (meth) acrylate, trimethylolpropane tri (Meth) acrylic acid such as pentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate and EO modified diglycerin tetra And a polyhydric alcohol, and 9,9-bis [4- (2- (meth) acryloyloxyethoxy) phenyl] fluorene. Specific examples thereof include Aronix M-220, M-306 (manufactured by Toagosei Co., Ltd.), Wright acrylate 1,9ND-A (manufactured by Kyowa Chemical Industry Co., Ltd.), Wright acrylate DGE-4A SR-531 (manufactured by Sartomer Company), CD-536 (manufactured by Sartomer Company), and the like can be given as examples of the photopolymerization initiator (trade name, manufactured by Kyoeisha Chemical Co., . If necessary, various epoxy (meth) acrylates, urethane (meth) acrylates, polyester (meth) acrylates and various (meth) acrylate monomers may be cited.

The radical polymerizable compound is preferably used in combination with a monofunctional radically polymerizable compound and a polyfunctional radically polymerizable compound from the viewpoint of achieving both adhesion with a polarizer and optical durability. It is generally preferable to use the compound in an amount of 3 to 80% by weight of the monofunctional radically polymerizable compound and 20 to 97% by weight of the polyfunctional radically polymerizable compound per 100% by weight of the radically polymerizable compound.

(Embodiment of radical polymerization curing type forming material)

The radical polymerization curing type forming material can be used as an active energy ray curing type or thermosetting type forming material. When an electron beam or the like is used for an active energy ray, the active energy ray curable-type forming material does not need to contain a photopolymerization initiator. However, when ultraviolet rays or visible rays are used for an active energy ray, the photopolymerization initiator 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 thermal polymerization initiator.

(Photopolymerization initiator)

The photopolymerization initiator in the case of using the radical polymerizing compound is appropriately selected by the active energy ray. In the case of curing by ultraviolet light or visible light, a photopolymerization initiator for ultraviolet or visible light cleavage is used. Examples of the photopolymerization initiator include benzophenone compounds such as benzyl, benzophenone, benzoyl benzoic acid and 3,3'-dimethyl-4-methoxybenzophenone; 4- (2-hydroxyethoxy) Aromatic-ketone compounds such as? -Hydroxy-?,? -Dimethylacetophenone, 2-methyl-2-hydroxypropiophenone and? -Hydroxycyclohexyl phenyl ketone; Methoxyacetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxyacetophenone, 2-methyl-1- [4- (methylthio) -1; Benzoin ether compounds such as benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin butyl ether, and anisoin methyl ether; Aromatic ketal compounds such as benzyl dimethyl ketal; Aromatic sulfonyl chloride-based compounds such as 2-naphthalenesulfonyl chloride; A photoactive oxime-based compound such as 1-phenone-1,2-propanedione-2- (o-ethoxycarbonyl) oxime; Thioxanthone, 2-chlorothioxanthone, 2-methylthioxanthone, 2,4-dimethylthioxanthone, isopropylthioxanthone, 2,4-dichlorothioxanthone, 2,4- Thioxanthone compounds such as santone, 2,4-diisopropylthioxanthone and dodecylthioxanthone; Camphorquinone; Halogenated ketones; Acylphosphine oxides; Acylphosphonates, and the like.

The blending amount of the photopolymerization initiator is 20 parts by weight or less based on 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, further preferably 0.1 to 5 parts by weight.

When the compound is 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.

Examples of the photopolymerization initiator include a compound represented by the following formula (1);

[Chemical Formula 1]

(Wherein R ¹ and R ² represent -H, -CH ₂ CH ₃ , -iPr or Cl, and R ¹ and R ² may be the same or different) It is preferable to use a compound to be displayed in combination with a high-sensitivity photopolymerization initiator for the light having a wavelength of 380 nm or more to be described later. When the compound represented by the 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 formula (1), diethyl thioxanthone in which R ¹ and R ² are -CH ₂ CH ₃ is particularly preferable. The composition ratio of the compound represented by the formula (1) in the coating material (coating liquid) is preferably 0.1 to 5 parts by weight, more preferably 0.5 to 4 parts by weight, and most preferably 0.9 By weight to 3 parts by weight.

It is also 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, Wheat, and the like, and ethyl 4-dimethylaminobenzoate is particularly preferable. When the polymerization initiator is used, the addition amount 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.

If necessary, a known photopolymerization initiator may be used in combination. Since the protective film having the UV absorbing function 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. Specific examples thereof include 2-methyl-1- (4-methylthiophenyl) -2-morpholinopropane-1-one, 2-benzyl- (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 (eta 5-2,4-cyclopentadien-1-yl) (1H-pyrrol-1-yl) -phenyl) titanium, and the like.

In particular, in addition to the photopolymerization initiator of the formula (1), a compound represented by the following formula (2) as a photopolymerization initiator;

(2)

(Wherein, R ^3, R ⁴ and R ⁵ are _{-H, -CH 3, -CH 2 CH} 3, or -iPr represents Cl, R ^3, R ⁴ and R ⁵ are the same or different) a Is preferably used. Methyl-1- (4-methylthiophenyl) -2-morpholinopropane-1-one (trade name: IRGACURE 907, manufactured by BASF), which is also a commercially available product, is preferably used as the compound represented by the formula Can be used. In addition, 2- (dimethylamino) -2 - [(4-methoxyphenyl) -butanone-1 (trade name: IRGACURE 369, (Methylphenyl) methyl] -1- [4- (4-morpholinyl) phenyl] -1-butanone (trade name: IRGACURE 379, BASF) is preferred because of its high sensitivity.

(Thermal polymerization initiator)

As the thermal polymerization initiator, it is preferable that polymerization is not initiated by thermal cleavage. For example, as the thermal polymerization initiator, the half-life temperature for 10 hours is preferably 65 占 폚 or higher, more preferably 75 to 90 占 폚. The half-life period is an index indicating the decomposition rate of the polymerization initiator, and refers to the time until the residual amount of the polymerization initiator becomes half. The decomposition temperature for obtaining a half-life at an arbitrary time and the half-life time at an arbitrary temperature are described in a manufacturer's catalog, and are described in, for example, "Organic Peroxide Catalog Ninth Edition (May 2003)" .

(10-hour half-life temperature: 64 占 폚), benzoyl peroxide (10 hours half-life temperature: 73 占 폚), 1,1-bis (t-butylperoxy) (10-hour half-life temperature: 49 占 폚), di (4-t-butylcyclohexyl) peroxydicarbonate, di (2-ethylhexyl) peroxydicarbonate (10-hour half-life temperature: 51 占 폚), t-butyl peroxyneodecanoate (10 hours half-life temperature: 48 占 폚), t-hexyl peroxypivalate, t- (10 hour half-life temperature: 64 占 폚), di-n-octanoyl peroxide, 1,1,3,3-tetramethylbutylperoxy-2-ethylhexanoate (10-hour half-life temperature: 73 ° C), t-butyl peroxyisobutyrate (10-hour half-life temperature: 81 ° C), 1, 1-di (t-hexyl perox And organic peroxides such as cyclohexane.

Examples of the thermal polymerization initiator include 2,2'-azobisisobutyronitrile (10-hour half-life temperature: 67 ° C), 2,2'-azobis (2-methylbutyronitrile) : 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 based on 100 parts by weight of the total amount of the curing component (radically 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 or 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. As a preferable epoxy compound, a compound (aromatic epoxy compound) having at least two epoxy groups and at least one aromatic ring in the molecule or at least two epoxy groups in the molecule, at least one of which is an adjacent 2 (Alicyclic epoxy compound) formed between the carbon atom and the carbon atom.

(Photo cationic polymerization initiator)

The cationic polymerization curing agent is a curing component which contains the epoxy compound and the oxetane compound described above, both of which are cured by cationic polymerization, so that a photocationic polymerization initiator is incorporated. This photo cationic polymerization initiator generates a cationic species or a Lewis acid by irradiation of an active energy ray such as visible light, ultraviolet ray, X-ray or electron beam to initiate polymerization reaction of an epoxy group or an oxetanyl group.

1-2. Solidification or curing process

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.

In the case of the coating liquid containing the resin component, in forming the transparent resin layer (4), after the coating liquid is applied, the resin component is solidified according to the kind of the resin component. The coating liquid containing the resin component is a solution or dispersion in which the resin component is dissolved in a solvent and is used, for example, as a solution of an aqueous system, a dispersion of an aqueous dispersion system, or a solution of a solvent system. The solidification means that the transparent resin layer 4 is formed by removing the solvent from the coating liquid. For example, when the resin component is a polyvinyl alcohol-based resin, the coating solution can be used as an aqueous solution, and can be solidified by heating (drying) or the like. Also, in the case where the resin component is water-soluble acrylic, the solidification can be similarly performed.

The drying temperature is not particularly limited and is usually about 60 to 200 占 폚. In the present invention, the drying temperature is preferably 120 占 폚 or lower, more preferably 100 占 폚 or lower from the viewpoint of curling inhibition. The drying time is preferably within 180 seconds, more preferably within 120 seconds, and even more preferably within 60 seconds.

On the other hand, in the formation of the transparent resin layer 4, after the coating liquid containing the curable component capable of constituting the transparent resin layer is applied, the curable component forms a transparent resin layer depending on the type of the curable component Perform the hardening that can be done. The coating liquid containing the curable component capable of constituting the resin may be used in a solventless system if the curable component indicates a coating liquid. The coating solution may be a solution in which the curable component is dissolved in a solvent. Further, even when the curable component indicates a coating solution, it can be used as a solution. The solvent may be appropriately selected depending on the curing component used. For example, when the acrylic monomer forming the acrylic resin is used as the curable component and the epoxy monomer forming the epoxy resin is used, the coating solution containing the curable component may be irradiated with actinic energy rays Curing can be carried out.

The formation of the transparent resin layer 4 by the curable forming material (coating liquid) is carried out by applying a curable forming material to the surface of the polarizer, and then curing.

The polarizer 1 may be subjected to a surface modification treatment before coating the curing-type forming material. Specific examples of the treatment include corona treatment, plasma treatment, and saponification treatment.

The curing-type forming material is used as an active energy ray curing type forming material or a thermosetting type forming material. The active energy ray curable type forming material can be used as an electron beam curable type, an ultraviolet ray curable type, or a visible light curable type. The mode of the curable-type forming material is preferably an active energy ray-curable-type forming material rather than the thermosetting type forming material from the viewpoint of productivity, and further, a visible ray-curable-type forming material is preferable from the viewpoint of productivity.

(Active energy radiation curable type)

In the active energy ray curable type forming material, the active energy ray curable type forming material is coated on the polarizer, and then the active energy ray curable type forming material is cured by irradiating an active energy ray (electron beam, ultraviolet ray, visible ray, . The irradiation direction of the active energy ray (electron beam, ultraviolet ray, visible ray, etc.) can be irradiated in any appropriate direction. Preferably, from the transparent resin layer 4 side.

(Electron beam hardening type)

In the electron beam hardening type, the irradiation condition of the electron beam may be any appropriate condition as far as it is capable of curing the active energy ray hardening type forming material. For example, in the electron beam irradiation, the acceleration voltage is preferably 5 kV to 300 kV, and more preferably 10 kV to 250 kV. If the accelerating voltage is less than 5 kV, the electron beam may not reach the deepest portion of the transparent resin layer 4, resulting in insufficient curing. If the accelerating voltage exceeds 300 kV, the penetration force through the sample is too strong, And the polarizer 1 may be damaged. 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) becomes inadequate to cure. When the irradiation dose exceeds 100 kGy, the protective film or the polarizer is damaged, resulting in a decrease in mechanical strength and yellowing, .

The electron beam irradiation is usually carried out in an inert gas atmosphere, but it may be carried out under a condition where air or oxygen is slightly introduced, if necessary.

(Ultraviolet curing type, visible light curing type)

In the production method of the present invention, it is preferable to use a visible ray having a wavelength range of 380 nm to 450 nm as the active energy ray, particularly an active energy ray having the largest irradiation amount of the visible ray having a wavelength range of 380 nm to 450 nm. As the active energy ray according to the present invention, a gallium-sealed metal halide lamp and an LED light source emitting light in a wavelength range of 380 to 440 nm are preferable. Or an ultraviolet ray and a visible ray such as a metal halide lamp, a fluorescent lamp, a tungsten lamp, a gallium lamp, an excimer laser or a solar ray, a low-pressure mercury lamp, a medium pressure mercury lamp, a high pressure mercury lamp, an ultra high pressure mercury lamp, an incandescent lamp, a xenon lamp, May be used. Alternatively, ultraviolet rays of a shorter wavelength than 380 nm may be blocked by using a band pass filter.

(Thermosetting type)

On the other hand, in the thermosetting type forming material, by heating, polymerization is initiated by a thermal polymerization initiator to form a cured layer. The heating temperature is set according to the thermal polymerization initiator, but is about 60 to 200 캜, preferably 80 to 150 캜.

2. Production method of polarizing film with pressure-sensitive adhesive layer

The method for producing a polarizing film with a pressure-sensitive adhesive layer of the present invention comprises the step of forming a pressure-sensitive adhesive layer on the transparent resin layer (4) of the transparent resin layer-attached polarizing protective film obtained by the above production method.

(1) Pressure-sensitive adhesive layer

A suitable pressure-sensitive adhesive may be used for forming the pressure-sensitive adhesive layer, and there is no particular limitation on the kind thereof. Examples of the pressure sensitive adhesive include a rubber pressure sensitive adhesive, an acrylic pressure sensitive adhesive, a silicone pressure sensitive adhesive, a urethane pressure sensitive adhesive, a vinyl alkyl ether pressure sensitive adhesive, a polyvinyl alcohol pressure sensitive adhesive, a polyvinyl pyrrolidone pressure sensitive adhesive, a polyacrylamide pressure sensitive adhesive and a cellulose pressure sensitive adhesive.

Among these pressure-sensitive adhesives, those having excellent optical transparency, exhibiting suitable wettability, cohesiveness and adhesiveness with adhesiveness, and excellent weather resistance and heat resistance are preferably used. An acrylic pressure-sensitive adhesive is preferably used to exhibit such characteristics.

The pressure-sensitive adhesive layer may be formed, for example, by applying the pressure-sensitive adhesive to a separator or the like having a peeled-off treatment, drying the polymerization solvent or the like by drying to form a pressure-sensitive adhesive layer, and then transferring it onto the transparent resin layer 4, A method in which the pressure sensitive adhesive is applied to the pressure sensitive adhesive layer 4 and the pressure sensitive adhesive layer is formed on the transparent resin layer 4 by drying and removing the polymerization solvent and the like. Further, in application of the pressure-sensitive adhesive, one or more solvents other than the polymerization solvent may be appropriately added.

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

The drying time is appropriate and an appropriate time can be employed. 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 of forming the pressure-sensitive adhesive layer, various methods can be used. Specific examples of the coating composition include extrusion coatings such as roll coats, kiss roll coats, gravure coats, reverse coats, roll brushes, spray coats, dip roll coats, bar coats, knife coats, air knife coats, curtain coats, lip coats, And the like.

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

When the pressure-sensitive adhesive layer is exposed, the pressure-sensitive adhesive layer may be protected with a sheet (separator) which has been peeled off until it is provided for actual use.

Examples of the constituent material of the separator include a plastic film such as polyethylene, polypropylene, polyethylene terephthalate and polyester film, a porous material such as paper, cloth, nonwoven fabric, a suitable material such as net, foam sheet, metal foil and laminate thereof (Thin leaf), and the like, 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 examples thereof include a polyethylene film, a polypropylene film, a polybutene film, a polybutadiene film, a polymethylpentene film, a polyvinyl chloride film, A co-extruded 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 mu m, and preferably about 5 to 100 mu m. If necessary, the separator may be subjected to antistatic treatment such as releasing treatment with a silicone, fluorine, long chain alkyl or fatty acid amide releasing agent or silica powder, antistatic treatment such as coating treatment, kneading, or vapor deposition . Particularly, the peeling property in the pressure-sensitive adhesive layer can be further improved by appropriately performing the peeling treatment such as the silicon treatment, the long-chain alkyl treatment, and the fluorine treatment on the surface of the separator.

(2) Surface protective film

The surface protective film may be provided on the polarizing film (including the polarizing protective film and the polarizing film with a pressure-sensitive adhesive layer) of the present invention. The surface protective film usually has a base film and a pressure-sensitive adhesive layer, and protects the polarizing film through the pressure-sensitive adhesive layer.

As the base film of the surface protective film, a film material having isotropy or near isotropy is selected from the viewpoints of inspection property and manageability. Examples of the film material include a polyester resin such as a polyethylene terephthalate film, a cellulose resin, an acetate resin, a polyether sulfone resin, a polycarbonate resin, a polyamide resin, a polyimide resin, And a transparent polymer such as an acrylic resin. Among these, a polyester resin is preferable. The base film may be used as a laminate of one kind or two or more kinds of film materials, or a stretched product of the film may be used. The thickness of the base film is generally 500 탆 or less, preferably 10 to 200 탆.

As the pressure-sensitive adhesive for forming the pressure-sensitive adhesive layer of the surface protective film, a pressure-sensitive adhesive containing a polymer such as a (meth) acryl-based polymer, a silicone-based polymer, a polyester, a polyurethane, a polyamide, a polyether, Can be used. From the viewpoints 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 (dry film thickness) of the pressure-sensitive adhesive layer is determined according to the adhesive force required. And is usually about 1 to 100 mu m, preferably 5 to 50 mu m.

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

3. Manufacturing method of optical laminate

The method for producing an optical laminate according to the present invention comprises a step of bonding a polarizing film with a pressure-sensitive adhesive layer obtained by the above-mentioned production method to an optical member via the pressure-sensitive adhesive layer without winding.

Since the polarizing film with a pressure-sensitive adhesive layer using the transparent resin layer-attached polarizer protective film and the transparent resin layer-attached polarizer protective polarizer film obtained by the production method of the present invention is curled, the film is not Can be used in the process. That is, the optical laminate can be produced by bonding to an optical member via a pressure-sensitive adhesive layer. When a protective polarizing film (with a transparent resin layer) is produced by a conventional production method, curling may occur at the end of the film, and when curling occurs, the film may be folded or wrinkled Or it is difficult to use it in the subsequent step as it is.

The optical member is not particularly limited. For example, the optical member is used for forming a liquid crystal display device such as a reflection plate, a transflective plate, a retardation plate (including a wave plate of ½ or ¼) One or more layers may be used. As the optical laminate, a reflection polarizing film or a transflective polarizing film in which a reflecting plate or a transflective reflecting plate is further laminated on the polarizing film with a pressure-sensitive adhesive layer obtained by the production method of the present invention, An elliptically polarizing film or a circularly polarizing film in which a retardation film is further laminated on the polarizing film with a pressure-sensitive adhesive layer, a polarizing film with a pressure-sensitive adhesive layer obtained by the production method of the present invention, Or a polarizing film in which a luminance improving film is further laminated on the polarizing film with a pressure-sensitive adhesive layer obtained by the production method of the present invention.

The optical laminate obtained by laminating the above optical member on the polarizing film with a pressure-sensitive adhesive layer of the present invention may be formed by sequentially laminating separately in the process of manufacturing a liquid crystal display or the like. However, It is advantageous in that the manufacturing process of the liquid crystal display device and the like can be improved. When two or more optical members are laminated, a suitable adhesive means such as a pressure-sensitive adhesive layer can be used. When the polarizing film with a pressure-sensitive adhesive layer is adhered, these optical axes can be arranged at appropriate disposition angles according to desired retardation characteristics and the like.

The transparent resin layer attachment piece protective polarizing film, the polarizing film with adhesive layer or the optical laminate obtained by the production method of the present invention can be suitably used for the formation of various devices such as a liquid crystal display device. The formation of the liquid crystal display device can be performed in a conventional manner. That is, the liquid crystal display device is generally formed by appropriately assembling components such as a liquid crystal cell, a transparent resin layer attachment polarizing protective film or an optical film, and an illumination system as needed, and incorporating a drive circuit. There are no particular limitations on the transparent resin layer-attached polarizer protective polarizing film obtained by the production method of the present invention, a polarizer film with a pressure-sensitive adhesive layer, or an optical laminate. As for the liquid crystal cell, any kind of IPS type or VA type can be used, and it is particularly preferable for the IPS type.

A backlight or a reflector is used for a liquid crystal display device or an illumination system in which a transparent resin layer attachment piece protective polarizing film, a polarizing film with a pressure-sensitive adhesive layer or an optical laminate is disposed on one side or both sides of the liquid crystal cell A suitable liquid crystal display device can be formed. In this case, the transparent resin layer attachment polarizing protective film, the polarizing film with adhesive layer or the optical laminate obtained by the production method of the present invention can be provided on one side or both sides of the liquid crystal cell. When the transparent resin layer-attached polarized protective polarizing film, the polarizing film with a pressure-sensitive adhesive layer, or the optical laminated body obtained by the production method of the present invention are provided on both sides, they may be the same or different. When a liquid crystal display device is formed, appropriate parts such as a diffusion plate, an anti-glare layer, an antireflection film, a protective plate, a prism array, a lens array sheet, a light diffusion plate, Or more.

[Example]

Hereinafter, the present invention will be described by way of examples, but the present invention is not limited to the following examples. Further, in each example, parts and% are all by weight. The conditions for leaving the room at room temperature, which are not specifically defined below, are all 23 deg. C, 65% R.H.

Production Example 1 (Production of Polarizer)

(IPA copolymerized PET) film (thickness: 100 占 퐉) film having an absorption rate of 0.75% and a glass transition temperature (Tg) of 75 占 폚 was subjected to corona treatment on one surface of the substrate, and a polyvinyl (Degree of polymerization: 4200, degree of saponification: 99.2 mol%) and acetoacetyl modified PVA (trade name: Goshefaimer Z200, degree of polymerization: 1200, degree of acetoacetyl modification: 4.6%, degree of saponification: ) At a ratio of 9: 1 was applied at 25 占 폚 and dried to form a PVA resin layer having a thickness of 11 占 퐉 to prepare a laminate.

The resultant laminate was free-end uniaxially stretched in an oven at 120 占 폚 at 2.0 times in the longitudinal direction (longitudinal direction) between rolls different in the main speed (air assisted stretching treatment).

Subsequently, the laminate was immersed (insolubilization treatment) for 30 seconds in an insolubilizing bath having a liquid temperature of 30 DEG C (an aqueous boric acid solution obtained by mixing 4 parts by weight of boric acid with 100 parts by weight of water).

Subsequently, the polarizing plate was immersed in a dyeing bath at a liquid temperature of 30 캜 while adjusting the iodine concentration and the immersion time so that the polarizing plate had a predetermined transmittance. In this Example, 0.2 part by weight of iodine was added to 100 parts by weight of water, and 1.0 part by weight of potassium iodide was compounded. The resultant was immersed in an iodine aqueous solution for 60 seconds (dyeing treatment).

Subsequently, the resultant was immersed in a crosslinking bath (aqueous solution of boric acid obtained by mixing 3 parts by weight of potassium iodide and 3 parts by weight of boric acid with respect to 100 parts by weight of water) at a liquid temperature of 30 占 폚 for 30 seconds (crosslinking treatment).

Thereafter, the laminate was immersed in a boric acid aqueous solution having a liquid temperature of 70 캜 (an aqueous solution obtained by mixing 4 parts by weight of boric acid with 100 parts by weight of water and 5 parts by weight of potassium iodide) (Longitudinal direction) so that the total draw ratio was 5.5 times (in-water elongation treatment).

Thereafter, the laminate was immersed in a cleansing bath (an aqueous solution obtained by mixing 4 parts by weight of potassium iodide with 100 parts by weight of water) at a liquid temperature of 30 DEG C (washing treatment).

Thus, an optical film laminate including a polarizer having a thickness of 5 占 퐉 was obtained.

Production Example 2 (Production of protective polarizing film)

(Meth) acrylic resin film having a lactone ring structure with a thickness of 40 탆 was subjected to corona treatment and used as a protective film.

40 parts by weight of N-hydroxyethyl acrylamide (HEAA), 60 parts by weight of acryloylmorpholine (ACMO) and 3 parts by weight of a photoinitiator (trade name: IRGACURE 819, manufactured by BASF) were mixed to prepare an ultraviolet curable adhesive. This was used as an adhesive for a protective film.

The ultraviolet curable adhesive was coated on the surface of the polarizer of Production Example 1 to coat the protective film so that the cured adhesive layer had a thickness of 1 占 퐉 and then irradiated with ultraviolet rays as an active energy ray, And cured. UV irradiation was performed using a gallium-encapsulated metal halide lamp (irradiation apparatus: Light HAMMER 10 manufactured by Fusion UV Systems, Inc., valve: V valve, peak illuminance: 1600 mW / cm ² , cumulative dose: 1000 / mJ / cm ² 440 nm)) was used and the illuminance of the ultraviolet ray was measured using a Sola-Check system manufactured by Solatell. Subsequently, the amorphous PET substrate was peeled off to produce a polarizing protective polarizing film (total thickness: 46 m) using a thin polarizer.

The obtained polarizing protective polarizing film had an optical characteristic of 42.8% in a single light transmittance and 99.99% in a polarization degree.

&Lt; Bulk transmittance (T) and polarization degree (P) >

The single-piece transmittance (T) and the degree of polarization (P) of the obtained protective polarizing film were measured using a spectral transmittance measuring instrument (Dot-3c, Murakami Color Research Laboratory Co., Ltd.) equipped with an integrating sphere.

The degree of polarization (P) is calculated by dividing the transmittance (parallel transmittance: Tp) when two identical polarizing films are superimposed so that the transmittance axes thereof are parallel to each other, and the transmittance : Tc) is applied to the following equation.

(%) = {(Tp-Tc) / (Tp + Tc)} 1/2 占 100

Each transmittance is represented by a Y value corrected for the visual sensitivity by a 2-degree field of view (C light source) of JIS Z8701 with 100% of the complete polarization obtained through a Glan Taylor prism polarizer.

Production Example 3 (Production of coating liquid for forming 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 concentration of 4% by weight and a viscosity of 60 mPa 占 퐏 (25 占 폚).

<Viscosity Measurement>

The viscosity of the coating solution was measured under the following conditions using a VISCOMETER R85 type viscometer RE85L (manufactured by Toki Industry Co., Ltd.).

Measuring temperature: 25 ° C

Rotation speed: 0.5 to 100 rpm

Cone rotor: 1 ° 34 '× R24

Example 1 (Production of a transparent resin layer-attached piece protective polarizing film)

The coating liquid (the transparent resin layer forming material) obtained in Production Example 3 was coated on the surface of the polarizer of the polarizing protective film obtained in Production Example 2 (the polarizing surface on which the protective film was not provided) using a gravure roll to a thickness of 25 탆 . The application was carried out all over the width direction of the polarizing protective polarizing film. After the application, a transparent resin layer having a thickness of 1 탆 was formed by hot air drying at 95 캜 for 30 seconds using a floating oven to prepare a transparent resin layer-attached polarizing protective film.

Example 2, Comparative Example 1

A transparent resin layer adhered piece protective polarizing film was produced in the same manner as in Example 1 except that the uncoated portions described in Table 1 were formed toward the inside from both ends in the width direction of the polarizing polarizing film in Example 1 .

The following evaluations were carried out using the transparent resin layer-attached piece protective polarizing film obtained in Examples and Comparative Examples. The evaluation results are shown in Table 1.

<Generation of curl>

The obtained transparent resin layer-attached polarizing protective polarizing film was evaluated for the amount of curl of the polarizing plate film immediately after being wound at 23 DEG C under the condition of 55% R.H. while the transparent resin layer was facing upward. The curl measurement was carried out by cutting a sample in a rhomboid shape of 45 degrees with respect to the absorption axis so as to include the end portion of the coating and one piece of 150 mm, and setting the sample so that the side of the transparent resin layer was on the horizontal table. The curl of the end portion of the coating of the set sample was measured with a ruler and evaluated according to the following evaluation criteria.

A: 10 mm or less

B: 10 mm or more and 30 mm or less

C: more than 30mm

[Table 1]

Any of the transparent resin layer-attached piece protective polarizing films of Examples was curled. On the other hand, in the transparent resin layer-attached protective polarizing film of Comparative Example 1, curling occurred such that the protective film side was convex and the transparent resin layer side was concave.

1: Polarizer
2: Protective film
3: polarized protective film
4: Transparent resin layer
5: Uncoated portion
10: transparent resin layer attached piece protective polarizing film
A: width direction of polarizing film

Claims (9)

A method for producing a transparent resin layer-attached polarizing protective film having a polarizing protective film having a protective film only on one side of a polarizer and a transparent resin layer provided on the other side of the polarizing film of the polarizing protective film,
Wherein the polarizer comprises a polyvinyl alcohol-based resin and has a thickness of 10 mu m or less,
Wherein the transparent resin layer is formed by a step of applying a coating liquid containing a curable component that can constitute a resin component or a transparent resin layer to the polarizer, and a step of solidifying or curing the obtained coating film,
In the step of coating the coating liquid, the uncoated portion is not applied in the region of less than 20 mm inward from both ends in the width direction of the polarizer, or the uncoated portion is coated over the entire width direction of the polarizer Is applied to the transparent resin layer (2). The method according to claim 1,
Wherein the application of the coating liquid is performed by applying a coating liquid over the entire width direction of the polarizer. 3. The method according to claim 1 or 2,
Wherein the width of the polarizer is 1,100 to 2,000 mm. 4. The method according to any one of claims 1 to 3,
Wherein the transparent resin layer is formed by solidifying the coating film, and the solidification is carried out by drying. 5. The method of claim 4,
Wherein the drying temperature is not higher than 120 占 폚. The method according to claim 4 or 5,
Wherein the drying time is within 180 seconds. &Lt; RTI ID = 0.0 &gt; 18. &lt; / RTI &gt; 7. The method according to any one of claims 1 to 6,
Wherein the coating liquid is a coating liquid containing a resin component, and the resin component is a polyvinyl alcohol-based resin. A pressure-sensitive adhesive sheet with a pressure-sensitive adhesive layer, which comprises a step of forming a pressure-sensitive adhesive layer on a transparent resin layer of a transparent resin layer-attached polarizer protective film obtained by the production method according to any one of claims 1 to 7 Gt; A process for producing an optical laminate, which comprises a step of bonding the polarizing film with a pressure-sensitive adhesive layer obtained by the production method of claim 8 to an optical member via the pressure-sensitive adhesive layer without winding.

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