JP2018119049A - Aqueous emulsion composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a composition which is excellent in adhesion to a base material film and a polarizer and enables thin film coating to the base material film without generating cissing.SOLUTION: An aqueous emulsion composition contains a polyolefin-based resin associated with and dispersed in an aqueous medium and a polyvinyl alcohol-based resin hydrated with and dispersed in the aqueous medium, where a content ratio of the polyolefin-based resin with respect to 100 pts.mass of the aqueous medium is less than 30 pts.mass or less, a content ratio of the polyvinyl alcohol-based resin with respect to 100 pts.mass of the aqueous medium is more than 0.5 pts.wt. and less than 3 pts.mass or less, and the polyvinyl alcohol-based resin has an average degree of polymerization of 1,000 or more and less than 3,300 and a degree of saponification of 98 mol% or less.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an aqueous emulsion composition.

  Liquid crystal display devices are used in various display devices by taking advantage of low power consumption, operation at low voltage, light weight and thinness.

  Patent Document 1 proposes a method of obtaining a polarizer by forming a polyvinyl alcohol-based resin layer on a base film to obtain a laminate, and subjecting this laminate to stretching treatment and dyeing treatment. According to this method, a thin polarizer can be stably manufactured.

  In order to improve the adhesion between the base film and the polyvinyl alcohol-based resin layer, it is described that the base film is subjected to corona treatment or a primer layer is formed on the base film. The method of applying the corona treatment to the base film is finally obtained because the surface of the base film may become charged and foreign matter may adhere or the uniformity of the base film surface tension may be reduced. Defects are likely to occur in the polarizing plate.

  On the other hand, the method of forming a primer layer on a base film is useful because it can solve the problems of corona treatment. However, since the surface of the base film is often hydrophobic and the polyvinyl alcohol resin layer is hydrophilic, the primer layer obtained from the conventional composition is composed of the base film and the polyvinyl alcohol resin. It was not possible to show good adhesion to both layers.

  In order to improve the adhesion to the adherend, Patent Document 2 proposes an emulsion composition containing an acid-modified polyolefin resin. When the composition described in Patent Document 2 is to be applied with a film thickness of 1 μm or less required for optical film applications, particularly when the surface of the substrate film is hydrophobic, There has been a problem that the surface repels the composition and cannot be applied with a uniform film thickness. Patent Document 2 describes that a polyvinyl alcohol-based resin may be used as a surfactant, that is, to form a micelle together with an acid-modified polyolefin resin, but the micelle of an acid-modified polyolefin resin was formed. There is no description of adding a polyvinyl alcohol-based resin later.

JP 2006-028904 A JP 10-298233 A

  An object of this invention is to provide the composition which is excellent in adhesiveness with respect to a base film and a polarizer, and can perform thin film coating, without producing a repelling etc. with respect to a base film.

[1] a polyolefin resin that is associated and dispersed in an aqueous medium;
A polyvinyl alcohol resin hydrated and dispersed in an aqueous medium,
The content ratio of the polyolefin-based resin with respect to 100 parts by mass of the aqueous medium is less than 30 parts by mass,
The content ratio of the polyvinyl alcohol-based resin with respect to 100 parts by mass of the aqueous medium is more than 0.5 parts by mass and less than 3 parts by mass,
The polyvinyl alcohol-based resin is an aqueous emulsion composition having an average polymerization degree of 1000 or more and less than 3300 and a saponification degree of 98 mol% or less.
[2] A laminated film having a cured layer of the aqueous emulsion composition according to [1] on at least one surface of the film,
A laminated film having a critical surface tension of 50 mN / m or less on a surface in contact with the cured layer in the film.
[3] A polarizing laminated film further comprising a polarizer having a dichroic dye oriented on a polyvinyl alcohol-based resin on the cured layer in the laminated film according to [2].
[4] The polarizing laminated film according to [3], further having a protective film on the polarizer.

  According to the composition of the present invention, it is excellent in adhesion to the base film and the polarizer, and thin film coating is possible without causing repelling or the like on the base film.

It is a schematic sectional drawing which shows an example of the laminated constitution of a laminated film. It is a schematic sectional drawing which shows an example of the laminated constitution of a light-polarizing laminated film. It is a schematic sectional drawing which shows an example of the laminated constitution of a polarizing plate.

  The aqueous emulsion composition of the present invention contains a predetermined amount of polyolefin resin and a predetermined amount of polyvinyl alcohol resin with respect to 100 parts by mass of the aqueous medium. The aqueous medium may contain the organic solvent mentioned later in addition to water. That is, the aqueous emulsion composition of the present invention contains an aqueous medium, a polyolefin resin, and a polyvinyl alcohol resin. In the emulsion composition of the present invention, the polyolefin resin is associated and dispersed in the aqueous medium, and the polyvinyl alcohol resin is hydrated and dispersed in the aqueous medium.

[Polyolefin resin]
Examples of polyolefin resins include polypropylene resins. Examples of the polypropylene resin include polypropylene, ethylene-propylene copolymer, propylene-butene copolymer, ethylene-propylene-butene terpolymer. Examples of the monomer copolymerized with ethylene and propylene include pentene, hexene, heptene, octene, and nonene in addition to butene. In the case of a copolymer, it may be a block copolymer or a random copolymer. These resins may be used alone or in combination of two or more.

  The weight average molecular weight of the polyolefin-based resin is usually 10,000 or more and 400,000 or less, preferably 100,000 or more and 300,000 or less. At first, the weight average molecular weight is measured by gel permeation chromatography (polystyrene equivalent value).

  The polyolefin resin may be a polyolefin resin obtained by modifying or chlorinating the resin exemplified above. That is, in the present invention, the polyolefin resin may contain at least one of a modified polyolefin resin or a chlorinated polyolefin resin. For the modification reaction, it is possible to use at least one polymerizable monomer selected from α, β-unsaturated dicarboxylic acid and its acid anhydride, and a compound having one or more double bonds per molecule. it can.

  In the present invention, the polyolefin-based resin is preferably mainly composed of unmodified polyolefin, and the ratio of the modified or chlorinated polyolefin-based resin is 10 parts by weight or less with respect to 100 parts by weight of the polyolefin-based resin. It may be 5 parts by weight or less, 1 part by weight or less, or 0 part by weight. By using such a polyolefin-based resin, it is possible to obtain a composition that is excellent in adhesion and can be applied to a thin film without causing repelling or the like on the base film. When the water-based emulsion composition contains a modified or chlorinated polyolefin resin, it is easier to apply a thin film than when it contains an unmodified polyolefin resin, but the adhesion in water resistance tests and heat resistance tests is improved. It tends to decline.

  Examples of the α, β-unsaturated dicarboxylic acid and acid anhydrides thereof include maleic acid, maleic anhydride, fumaric acid, citraconic acid, citraconic anhydride, mesaconic acid, itaconic acid, itaconic anhydride, aconitic anhydride, and aconitic anhydride. An acid etc. are mentioned.

  Examples of the compound having one or more double bonds per molecule include (meth) acrylic acid monomers. Specifically, (meth) acrylic acid; (meth) methyl acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, (Meth) acrylic acid-2-hydroxypropyl, (meth) acrylic acid-2-hydroxybutyl, (meth) acrylic acid-4-hydroxybutyl, (meth) acrylic acid cyclohexyl, (meth) acrylic acid 2-ethylhexyl, ( Tetrahydrofurfuryl (meth) acrylate, isobornyl (meth) acrylate, benzyl (meth) acrylate, glycidyl (meth) acrylate, di (meth) acrylic acid (di) ethylene glycol, di (meth) acrylic acid-1, 4-butanediol, di (meth) acrylic acid-1,6-hexanediol, tri (meth) acrylate (Meth) acrylic acid esters such as trimethylolpropane diacid, glycerin di (meth) acrylate, 2-ethylhexyl (meth) acrylate, lauryl (meth) acrylate, stearyl (meth) acrylate; acrylamide, etc. Can be mentioned. Furthermore, examples of styrene monomers include styrene, α-methylstyrene, paramethylstyrene, and chloromethylstyrene. Examples of monomers that can be used in combination with these monomers include vinyl monomers such as divinylbenzene, vinyl acetate, and vinyl versatate. The said monomer may be used independently and may use 2 or more types together.

  The modification of the polyolefin resin involves dissolving the polyolefin resin as a raw material in an organic solvent such as toluene or xylene and then reacting the monomer at 120 to 150 ° C. in the presence of a radical generator in the solution state. Method, The polyolefin resin as a raw material is heated to a softening temperature or higher than the melting point and melted in an autoclave or a uniaxial or biaxial multiaxial extruder in the presence or absence of a radical generator. And a method of reacting the above monomers.

  Examples of the radical generator used in the modification reaction include di-tert-butyl peroxyphthalate, tert-butyl hydroperoxide, dicumyl peroxide, benzoyl peroxide, tert-butyl peroxybenzoate, and tert-butyl peroxy. Peroxides such as 2-ethylhexanoate, tert-butyl peroxypivalate, methyl ethyl ketone peroxide, di-tert-butyl peroxide, lauroyl peroxide; azobisisobutyronitrile, azobisisopropionitrile, etc. And azonitriles.

  The amount of the radical generator used is preferably 0.1 to 5 parts by weight, more preferably 0.2 to 1.7 parts by weight with respect to 100 parts by weight of the polyolefin resin as a raw material. When the amount of the radical generator is 0.1 parts by weight or more, the modification reaction easily proceeds, and when it is 5 parts by weight or less, a modified polyolefin resin having a predetermined molecular weight is easily obtained.

  The acid value of the modified polyolefin resin thus obtained is preferably 1 to 100 mg · KOH / g, more preferably 2 to 50 mg · KOH / g. By neutralizing at the time of emulsification with such an appropriate acid value, the modified polyolefin itself has an effect as a surfactant.

  Moreover, it is preferable that modified polyolefin resin contains 0.01-10 weight part of said monomers with respect to 100 weight part of polyolefin resin, and it is more preferable to contain in the ratio of 0.1-5 weight part.

  The chlorination reaction can be performed by a known method. As an example of the production method, a polyolefin resin as a raw material is dissolved in a chlorinated solvent, and is irradiated with ultraviolet rays or in the presence of the above radical generator including an organic peroxide such as benzoyl peroxide. Chlorine gas can be blown and reacted at a temperature of 50 to 150 ° C. in a solution state or in a non-uniformly dispersed state at normal pressure or under pressure. By such a chlorination reaction, it is preferable that the polyolefin resin as a raw material is chlorinated in an amount of 5 to 50 parts by weight, and 10 to 40 parts by weight with respect to 100 parts by weight of the polyolefin resin. Is more preferable.

  After completion of the chlorination reaction, it is preferable to blend a compound having one epoxy group per molecule and / or an oligomer thereof in order to impart thermal stability. Degradation of chlorinated polyolefin resin due to dehydrochlorination Can be prevented and stabilized.

  As a compound having one epoxy group per molecule or an oligomer thereof, for example, a compound having good compatibility with chlorinated polyolefin is preferable. For example, phenyl glycidyl ether, 2-methylphenyl glycidyl ether, tert-butylphenyl glycidyl ether, 4-chlorophenyl glycidyl ether, 4-methoxyphenyl glycidyl ether, 2-biphenyl glycidyl ether, 1-naphthyl glycidyl ether, methyl glycidyl ether, isopropyl Examples thereof include glycidyl ether, butyl glycidyl ether, tert-butyl glycidyl ether, and 2-ethyl glycidyl ether. These may be used alone or in combination of two or more.

  The amount of the compound having one epoxy group per molecule and the amount of its oligomer used is preferably 0.1 to 50 parts by weight, particularly 1 to 10 parts by weight, per 100 parts by weight of chlorinated polyolefin.

  The acid value of the chlorinated modified polyolefin resin thus obtained is preferably 1 to 100 mg · KOH / g, more preferably 2 to 50 mg · KOH / g.

  The polyolefin resin is commercially available, for example, as a composition containing a polyolefin resin. As such a composition, Hardren (registered trademark), Toyo Tac (registered trademark) manufactured by Toyobo Co., Ltd., Arrow Base (registered trademark) manufactured by Unitika Co., Ltd., or the like can be used.

[Surfactant]
In order to emulsify the polyolefin resin, a surfactant may be contained. Of course, when a self-emulsifying emulsion is used, a surfactant may not be contained. In order to form a self-emulsifying emulsion, for example, a compound having an anionic functional group may be graft-polymerized to the polyolefin resin as the polyolefin resin. The anionic functional group is preferably a carboxyl group, and examples of the compound having an anionic functional group include the α, β-unsaturated dicarboxylic acid and acid anhydrides thereof.

  Surfactants include polyoxyethylene alkyl phenyl ethers, polyoxyethyl alkyls, polyoxyethylene alkyl aryl ethers, polyethylene alkyl esters, sorbitan alkyl esters, polyoxyethylene sorbitan alkyl esters, poly (oxyethylene -Nonionic surfactants such as -oxypropylene) block copolymers.

  Examples of the anionic surfactant include higher alkyl sulfates, alkyl, aryl polyoxyethylene sulfate esters, higher fatty acid salts, alkylaryl sulfonates, alkyl phosphate esters, and the like. As the cationic surfactant, an alkoxylated amine can be used.

  In addition, a polymer emulsifier or a dispersant may be used. Use of these contributes to stabilization because the viscosity in the system can be increased. Representative examples of those that contribute to the object of the present invention include gelatin, tragacanth gum, starch, methyl fibrin, carboxymethylcellulose, hydroxypropylcellulose, hydroxyethylcellulose, and other polymers, or their derivatives and polyvinyl alcohol. Examples of water-soluble organic polymers or dispersants such as partially saponified polyvinyl alcohol, ethylene-vinyl alcohol copolymers, ethylene vinyl alcohol vinyl acetate copolymers, and polyacrylates include barium sulfate, calcium sulfate, and barium carbonate. And inorganic compounds such as talc, bentonite, silicic acid, diatomaceous earth, and clay, and metal oxide powders.

  The surfactants including the anionic, nonionic, cationic, and polymeric or inorganic dispersants described above may be used alone, but the physical properties are improved when used in combination of two or more. There are many cases. These surfactants can also contain reactive surfactants. As the reactive surfactant, an anionic or nonionic surfactant is generally used. As the reactive surfactant, those having a polyoxyethylene group as a hydrophilic group in the molecule are particularly desirable, and examples thereof include adducts of alkylpropenyl (di) phenol polyethylene oxide and / or sulfate esters thereof. Furthermore, a combination of a non-reactive surfactant and a reactive surfactant may be used, and two or more types of each surfactant may be used. The amount of the surfactant or a mixture thereof is preferably 0.01 to 100 parts by weight with respect to 100 parts by weight of the polyolefin resin.

[Polyvinyl alcohol resin]
Examples of the polyvinyl alcohol resin include polyvinyl alcohol and derivatives thereof. Examples of polyvinyl alcohol derivatives include polyvinyl formal and polyvinyl acetal. In addition, olefins such as ethylene and propylene, unsaturated carboxylic acids such as acrylic acid, methacrylic acid, and crotonic acid, and alkyl esters thereof, acrylamide, and the like can be used. A polyvinyl alcohol-type resin may use only 1 type, and may use 2 or more types together.

  The average degree of polymerization of polyvinyl alcohol is 1000 or more and less than 3300, preferably more than 1000 and less than 3300, more preferably 1500 or more and 3000 or less. By setting it as such an average degree of polymerization, thin film coating becomes easy and it becomes easy to improve the adhesive force to the adherend of a hydrophobic surface.

  The saponification degree of the polyvinyl alcohol resin is 98 mol% or less, preferably 97 mol% or less, more preferably less than 90 mol%, preferably 80 mol% or more, more preferably 85 mol%. % Or more. In the case of a high degree of saponification, precipitation may occur in the aqueous emulsion composition.

  The polyvinyl alcohol resin may contain additives such as a plasticizer and a surfactant. Examples of the plasticizer include polyols and condensates thereof. Specific examples include glycerin, diglycerin, triglycerin, ethylene glycol, propylene glycol, and polyethylene glycol. The amount of the plasticizer used is not particularly limited, but is preferably 20 parts by weight or less per 100 parts by weight of the polyvinyl alcohol resin.

  Examples of commercially available polyvinyl alcohol resins include polyvinyl alcohol 203, polyvinyl alcohol 205, polyvinyl alcohol 217, polyvinyl alcohol 220, polyvinyl alcohol 224, polyvinyl alcohol 226, etc. manufactured by Kuraray Co., Ltd., DM- 10, DM-17, DM-20 and the like.

[Aqueous medium]
The aqueous medium is water alone or a mixed solvent containing water as a main component and a component miscible with water. In addition, a main component means the component with most content (mass part) with respect to 100 mass parts of aqueous media. Examples of components miscible with water include methanol and ethanol. In the present invention, the proportion of water contained in 100 parts by mass of the aqueous medium is preferably 70 parts by mass or more, and more preferably 90 parts by mass or more.

[Method for producing aqueous emulsion composition]
First, the polyolefin resin (preferably unmodified polyolefin resin) is dissolved or dispersed in an organic solvent to prepare an oily solution. The dissolution is preferably performed at about 60 to 120 ° C. using a mixer having a high shearing force. On the other hand, the surfactant is dissolved in water to prepare an aqueous emulsifier solution.

  After each of the oily solution and the aqueous emulsifier solution is prepared in this manner, the oily solution is gradually added to the aqueous emulsifier solution, or the aqueous emulsifier solution is gradually added to the oily solution, for example, with a stirrer such as a propeller-type stirrer. Pre-disperse with stirring for about 120 minutes. In consideration of ease of granulation in the next step and stability of the emulsion, the oily solution is preferably 5 to 70 parts by weight, more preferably 10 to 60 parts by weight, in 100 parts by weight of the dispersion. More preferred is 50 parts by weight.

  This dispersion is supplied using a liquid feeding means such as an emulsifier pump. The emulsifier is capable of forming emulsion particles with small particle size and sharp particle size distribution by the action of shearing force, collision force, pressure fluctuation and cavitation generated by the rotor that can rotate at high speed and the screen surrounding it. Is preferred. Examples of the emulsifier include Claremix (registered trademark) series manufactured by M Technique Co., Ltd.

  Using such an emulsifier, the average particle size is, for example, 0.01 to 1 even if the amount of the surfactant is small due to the action of shearing force, collision force, pressure fluctuation and cavitation generated by the rotor and screen. Stable micelles having a small particle size of 0.0 μm, preferably 0.01 to 0.8 μm, and a sharp particle size distribution can be formed. In the present invention, the average particle diameter means a value measured by a particle size distribution measuring device (laser scattering method).

  After forming the emulsion, an aqueous emulsion composition can be obtained by concentrating the organic solvent under reduced pressure. The obtained aqueous emulsion composition may be filtered to remove unemulsified or insoluble matter. In this way, an aqueous emulsion composition substantially free of an organic solvent can be obtained.

  In the present invention, after the emulsion is formed, a polyvinyl alcohol resin is further added to form an aqueous emulsion solution. By such an operation, an emulsion composition in which the polyolefin resin is associated and dispersed in the aqueous medium and the polyvinyl alcohol resin is hydrated and dispersed in the aqueous medium can be obtained. For example, the aqueous emulsion composition of the present invention can be obtained by dissolving a polyvinyl alcohol-based resin in water and mixing them.

  In the present invention, the content ratio of the polyolefin resin to 100 parts by mass of the aqueous medium is less than 30 parts by mass, preferably 20 parts by mass or less, and may be 15 parts by mass or less. The content ratio of the polyolefin-based resin with respect to 100 parts by mass of the aqueous medium is preferably 0.1 parts by mass or more, and more preferably 1 part by mass or more. By setting the content ratio of the polyolefin-based resin in such a range, it is easy to increase the adhesion force of the hydrophobic surface to the adherend.

  In this invention, it is preferable that the content rate of the polyvinyl alcohol-type resin with respect to 100 mass parts of aqueous media exceeds 0.5 mass part, and is 1.0 mass part or more. The content ratio of the polyvinyl alcohol resin to 100 parts by mass of the aqueous medium is less than 3 parts by mass, and preferably 2.8 parts by mass or less. When the content ratio of the polyvinyl alcohol resin is 0.5 parts by mass or less, repellency may occur when the aqueous emulsion composition is applied. When the content is 3 parts by mass or more, the polyolefin resin adheres to the adherend. May be disturbed.

[Basic components]
A basic substance may be added to the aqueous emulsion composition. By adding a basic substance, it can be adjusted to a desired pH (for example, pH 5 to 10, preferably 7 to 9). A basic substance may use only 1 type and may use 2 or more types together.

  Basic substances include (di) methylamine, (di) ethylamine, (di) propylamine, (di) butylamine, (di) hexylamine, (di) octylamine, (di) ethanolamine, (di) propanol Organic basic substances such as amine, N-methyldiethanolamine, triethylamine, N, N-dimethylethanolamine, 2-dimethylamino-2-methyl-1-propanol, 2-amino-2-methyl-1-propanol, morpholine Inorganic basic substances such as aqueous ammonia, sodium hydroxide, potassium hydroxide, sodium carbonate, sodium hydrogen carbonate, ammonium carbonate, potassium carbonate and the like can be mentioned. When these basic substances are used, only one kind may be used, or two or more kinds of basic substances may be used in combination. The amount of the basic substance varies depending on the degree of modification of the polyolefin resin, but is preferably 0.1 to 10 parts by weight with respect to 100 parts by weight of the polyolefin resin.

[Other additives]
Further, an additive may be added to the aqueous emulsion composition. Additives include antistatic agents, organic pigments, inorganic pigments, organic dyes, inorganic dyes, thickeners, sagging inhibitors, thixotropic agents, viscosity modifiers, antifoaming agents, weathering agents, UV absorbers, thickeners , Antifungal agents, stabilizers, water-based paints, oxazoline-containing polymers, and urethane-based polymer aqueous emulsions.

[Production method of laminated film]
FIG. 1 is a laminated film including a cured layer 1 and a film 2 of the aqueous emulsion composition of the present invention. The aqueous emulsion composition of the present invention can be coated on a film by a known method, and after coating, part or all of the aqueous medium contained in the composition is dried to form a cured layer of the aqueous emulsion composition. Thus, a laminated film can be produced. That is, the laminated film has a cured layer of the aqueous emulsion composition on at least one surface of the film. The laminated film may have a cured layer of the aqueous emulsion composition on one side of the film as shown in FIG. 1 (a), or on both sides as shown in FIG. 1 (b). May be.

  A thermoplastic resin film is mentioned as a film which coats an aqueous emulsion composition. Specific examples of thermoplastic resins include cellulose resins such as triacetyl cellulose, polyester resins, polyethersulfone resins, polysulfone resins, polycarbonate resins, polyamide resins, polyimide resins, polyolefin resins, ( Mention may be made of (meth) acrylic resins, cyclic polyolefin resins (norbornene resins), polyarylate resins, polystyrene resins, polyvinyl alcohol resins, and mixtures thereof.

  The surface tension of water is 71 to 72 mN / m at room temperature, and if the film has a surface exhibiting a surface tension away from this value, the adhesion and wettability tend to be low. According to the aqueous emulsion composition of the present invention, even when the surface tension of the film surface is 50 mN / m or less (that is, the surface tension away from the surface tension of water), it is preferable that no repelling occurs. Thin film coating can be performed. In the present invention, the surface tension refers to a value calculated from a Zisman plot method using contact angles of several kinds of solvents. For example, the surface tension of polyethylene terephthalate is 43 mN / m, the surface tension of polymethyl methacrylate is 43 mN / m, the surface tension of polyvinyl chloride is 39 mN / m, and the surface tension of polyethylene is 31 mN / m. Yes, the surface tension of polypropylene is 29 mN / m.

  As drying temperature after coating, it is preferable that it is 70-140 degreeC, and it is preferable that it is 90-120 degreeC. Thus, it is easy to exhibit adhesion by drying at a temperature close to or exceeding the melting point of the polyolefin resin contained in the aqueous emulsion composition. The drying time after coating is preferably 10 seconds to 30 minutes, and more preferably 30 seconds to 10 minutes.

  According to the aqueous emulsion composition of the present invention, since the thin film coating is possible, the thickness of the cured layer of the aqueous emulsion composition can be 0.01 to 1 μm, and 0.05 to 0.5 μm. You can also

  Conventionally, the film has been subjected to corona treatment or plasma treatment to exhibit adhesion, but according to the aqueous emulsion composition of the present invention, adhesion can be ensured without the above treatment. That is, in the method for producing a laminated film, the film may not be subjected to corona treatment or plasma treatment before application of the aqueous emulsion composition. In this way, by applying no corona treatment or plasma treatment to the film prior to the application of the aqueous emulsion composition, foreign matter adhesion due to surface modification is prevented, and deterioration of surface uniformity is also prevented. Can be.

[Method for producing polarizing laminated film]
A polarizing laminated film can be produced by further forming a polyvinyl alcohol-based resin layer on the laminated film and subjecting it to a stretching treatment and a dyeing treatment. The schematic diagram shown in FIG. 2 is an example showing the layer structure of the polarizing laminated film, and the polarizing laminated film shown in FIG. 2 is cured on the film 2 (base film) of the aqueous emulsion composition of the present invention. A layer 1 is provided, and a polarizer layer 3 is further provided.

  First, a polyvinyl alcohol-based resin aqueous solution is applied and dried on the surface of the laminate on which the cured layer of the aqueous emulsion composition is formed to form a polyvinyl alcohol-based resin layer. The polyvinyl alcohol-based resin aqueous solution can be prepared by, for example, dissolving a polyvinyl alcohol-based resin powder, a pulverized product, a cut product, or the like in appropriately heated water (hot water). The concentration of the aqueous solution is preferably 2 to 20 parts by weight, more preferably 4 to 10 parts by weight with respect to 100 parts by weight of water.

  As a polyvinyl alcohol-type resin, the polyvinyl alcohol-type resin conventionally used as a polarizer is used suitably. Examples of the polyvinyl alcohol resin include polyvinyl alcohol and derivatives thereof. Examples of polyvinyl alcohol derivatives include polyvinyl formal and polyvinyl acetal. In addition, olefins such as ethylene and propylene, unsaturated carboxylic acids such as acrylic acid, methacrylic acid, and crotonic acid, and alkyl esters thereof, acrylamide, and the like can be used.

  The degree of polymerization of polyvinyl alcohol is preferably from 100 to 10,000, and more preferably from 1,000 to 10,000. A saponification degree of 80 to 100 mol% is generally used.

  Application of the aqueous emulsion composition on the hardened layer of the aqueous solution includes, for example, a wire bar coating method, a roll coating method such as reverse coating and gravure coating, a spin coating method, a screen coating method, a fountain coating method, a dipping method, and a spray method. A die coating method, a comma coating method, a lip coating method, or the like can be appropriately selected and used.

  The drying temperature is preferably 50 to 200 ° C, more preferably 60 to 150 ° C. The drying time is preferably 5 to 30 minutes.

  The polyvinyl alcohol-based resin layer is formed with a thickness such that the thickness of the obtained polarizer is 10 μm or less in consideration of the draw ratio in the drawing treatment applied to the laminate. The thickness of the unstretched polyvinyl alcohol resin layer is preferably 3 to 20 μm, more preferably 5 to 15 μm.

<Extension process>
In the stretching step, either a dry stretching process or a wet stretching process can be used. In the stretching step, stretching is performed by uniaxially stretching the laminate. Uniaxial stretching may be either longitudinal stretching performed in the longitudinal direction of the laminate or transverse stretching performed in the width direction of the laminate.

  In transverse stretching, the film can be contracted in the longitudinal direction while stretching in the width direction. Examples of the transverse stretching method include a fixed end uniaxial stretching method in which one end is fixed via a tenter, and a free end uniaxial stretching method in which one end is not fixed.

  On the other hand, in the longitudinal stretching, for example, an inter-roll stretching method, a compression stretching method, a stretching method using a tenter, or the like can be used. Further, the stretching treatment can be performed in multiple stages. Furthermore, the stretching treatment can be performed by performing biaxial stretching, oblique stretching, or the like.

  The dry stretching treatment is preferable in that a wide temperature range can be set when stretching the laminate. In the dry stretching treatment, the laminate is preferably heated to 50 to 200 ° C, more preferably 80 to 180 ° C, and still more preferably 100 to 160 ° C. In the stretching step, when a dry stretching process is included, this dry stretching process is preferably performed before the dyeing process.

  The treatment liquid used in the wet stretching process can contain an iodide compound. When an iodide compound is contained in the treatment liquid, the iodide compound concentration is preferably 0.1 to 10 parts by weight, more preferably 0.2 to 5 parts by weight with respect to 100 parts by weight of the solvent. The treatment temperature in the wet stretching method is preferably 25 ° C. or higher, more preferably 30 to 85 ° C., and even more preferably 50 to 70 ° C. The immersion time is preferably 10 to 800 seconds, and more preferably 30 to 500 seconds. In addition, a stretching process can be performed together with the dyeing process and the crosslinking process.

  In the stretching step, the stretching process is performed so that the total stretching ratio is 4 to 8 times the original length of the laminate. The total draw ratio is preferably 5 to 7 times. The total draw ratio refers to the cumulative draw ratio including stretching in those steps when stretching is involved in steps other than the stretching step. The total draw ratio is appropriately determined in consideration of the draw ratio in other steps. When the total draw ratio is low, the orientation is insufficient and it is difficult to obtain a polarizer having high optical properties (polarization degree). On the other hand, when the total draw ratio is too high, stretch breakage tends to occur. Further, the polarizer becomes too thin, and the processability in the subsequent process may be reduced.

  In the stretching step, as described in “Patent No. 4751481”, a wet stretching process can be performed after the air auxiliary stretching process. The stretching temperature in the air auxiliary stretching treatment is preferably set to a high temperature of 60 to 180 ° C, and more preferably 95 to 150 ° C. Moreover, it is preferable to set it as 1.3-4 times, and, more preferably, the draw ratio in an air auxiliary extending | stretching process is set to 1.5-3 times. Moreover, it is preferable that the process temperature in the wet-type extending | stretching process given after an air auxiliary | assistant extending | stretching process shall be 50-80 degreeC, More preferably, it is 60-70 degreeC. The immersion time is preferably 5 to 120 seconds, more preferably 10 to 60 seconds. Moreover, it is preferable that the draw ratio in a wet-type extending | stretching process sets a total draw ratio to 4-7 times, More preferably, it is 5-6 times.

  In the stretching step, when the air auxiliary stretching process and the wet stretching process are included, it is preferable to perform the air auxiliary stretching process before the dyeing process and the wet stretching process after the dyeing process. In this case, the treatment bath used for the wet stretching treatment also serves as a crosslinking bath, and it is preferable to perform the crosslinking treatment together with the wet stretching treatment.

<Crosslinking process>
In the crosslinking step, a crosslinking treatment is performed using a boron compound as a crosslinking agent. The crosslinking treatment can be performed together with the dyeing treatment and the stretching treatment. Moreover, the crosslinking treatment can be performed in a plurality of times. As the boron compound, for example, boric acid, borax or the like can be used. The boron compound is generally used in the form of an aqueous solution or a water-organic solvent mixed solution.

  When using a boric acid aqueous solution, the boric acid concentration in the boric acid aqueous solution is preferably 1 to 10 parts by weight, more preferably 2 to 7 parts per 100 parts by weight of the solvent in order to impart heat resistance depending on the degree of crosslinking. Parts by weight. The boric acid aqueous solution or the like can contain an iodide compound such as potassium iodide. When the iodide compound is contained in the boric acid aqueous solution, the iodide compound concentration is preferably 0.1 to 10 parts by weight, more preferably 0.5 to 8 parts by weight with respect to 100 parts by weight of the solvent. .

  The crosslinking treatment can be performed by immersing the laminate in a boric acid aqueous solution or the like. The treatment temperature in the crosslinking treatment is preferably 25 ° C. or higher, more preferably 30 to 85 ° C., and further preferably 30 to 60 ° C. The treatment time is preferably 5 to 800 seconds, more preferably 8 to 500 seconds.

<Insolubilization process>
An insolubilization process can be performed before performing a dyeing process or a bridge | crosslinking process to a laminated body. An insolubilization process aims at giving the insolubilization process for not dissolving a polyvinyl alcohol-type resin layer.

  In the insolubilization step, insolubilization treatment can be performed by immersing the polyvinyl alcohol-based resin layer in the laminate in a solution containing a boron compound such as boric acid or borax. The solution is generally used in the form of an aqueous solution or a water-organic solvent mixed solution.

  When using the boric acid aqueous solution, the boric acid concentration of the boric acid aqueous solution is preferably 1 to 4 parts by weight with respect to 100 parts by weight of the solvent. The treatment temperature in the insolubilization step is preferably 25 ° C. or higher, more preferably 30 to 85 ° C., and further preferably 30 to 60 ° C. The treatment time is preferably 5 to 800 seconds, more preferably 8 to 500 seconds.

<Washing process>
The laminate can be subjected to a dyeing process and a stretching process, and further subjected to a crosslinking process. After these processes are performed, a washing process can be performed.

  In the cleaning step, a cleaning process can be performed using a potassium iodide solution. The potassium iodide concentration in the potassium iodide solution is preferably 0.5 to 10 parts by weight, more preferably 0.5 to 8 parts by weight, and still more preferably 1 to 6 parts by weight with respect to 100 parts by weight of the solvent. It is.

  In the washing treatment with a potassium iodide solution, the treatment temperature is preferably 5 to 60 ° C, more preferably 10 to 40 ° C. The immersion time is preferably 1 to 120 seconds, more preferably 3 to 90 seconds. There is no particular limitation on the stage of the washing treatment with the potassium iodide solution as long as it is before the drying treatment.

  Further, as a cleaning process, a water cleaning process can be performed. The water washing treatment is performed by immersing a polyvinyl alcohol resin in pure water such as ion exchange water or distilled water. The water washing temperature is preferably 5 to 50 ° C, more preferably 10 to 45 ° C, and further preferably 15 to 40 ° C. The immersion time is preferably 5 to 300 seconds, more preferably 10 to 240 seconds.

  In the washing step, washing treatment with a potassium iodide solution and water washing treatment may be combined. For example, a solution in which liquid alcohol such as methanol, ethanol, isopropyl alcohol, butanol, propanol or the like is appropriately blended may be used.

<Drying process>
Moreover, after performing each process mentioned above, finally, a drying process can be performed and a polarizer layer can be manufactured. In the drying process, an optimal drying time and drying temperature are set according to the moisture content required for the obtained polarizer layer. Specifically, the drying temperature is preferably 20 to 150 ° C, more preferably 40 to 100 ° C. If the drying temperature is too low, the drying time becomes longer, which is not preferable because efficient production cannot be performed. On the other hand, when the drying temperature is too high, the obtained polarizer is deteriorated and deteriorated in terms of optical characteristics and hue. The heat drying time is preferably 1 to 10 minutes. Thus, the thickness of the polarizer layer obtained can be 10 micrometers or less, for example.

[Production method of polarizing plate]
A polarizing plate can be produced by laminating a transparent protective film via an adhesive layer on the polarizer layer in the polarizing laminate film obtained as described above. For example, the polarizing plate shown in FIG. 3A has a polarizer layer 3 on the film 2 (base film) through the cured layer 1 of the aqueous emulsion composition of the present invention. A transparent protective film 4 is laminated on the adhesive layer 6 on the top. Furthermore, you may peel the base film in a light-polarizing laminated film, and may laminate | stack a transparent protective film through an adhesive bond layer.

  As a material constituting the transparent protective film, for example, a thermoplastic resin excellent in transparency, mechanical strength, thermal stability, moisture barrier property, isotropy and the like is used. Specific examples of such thermoplastic resins include cellulose resins such as triacetyl cellulose, polyester resins, polyethersulfone resins, polysulfone resins, polycarbonate resins, polyamide resins, polyimide resins, and polyolefin resins. Examples include resins, (meth) acrylic resins, cyclic polyolefin resins (norbornene resins), polyarylate resins, polystyrene resins, polyvinyl alcohol resins, and mixtures thereof.

  Examples of the adhesive forming the adhesive layer include a water-soluble adhesive and an active energy ray-curable adhesive made of a resin composition that is cured by irradiation with active energy rays. Some water-soluble adhesives have, for example, a polyvinyl alcohol-based resin as a main component, and may contain a crosslinking agent. Examples of the active energy ray-curable adhesive include those containing a polymerizable compound and a photopolymerization initiator. Examples of the polymerizable compound include photopolymerizable monomers such as a photocurable epoxy monomer, a photocurable acrylic monomer, and a photocurable urethane monomer, and oligomers derived from the photopolymerizable monomer.

  Moreover, you may use the aqueous | water-based emulsion composition of this invention as an adhesive agent which forms an adhesive bond layer. As described above, the aqueous emulsion composition of the present invention exhibits good adhesion even to a film having a surface tension of 50 mN / m or less. Therefore, the adhesion between the polarizer and the transparent protective film is good by laminating the transparent protective film having a surface tension of 50 mN / m or less and the polarizer layer through the cured layer of the aqueous emulsion composition. A polarizing plate can be obtained. For example, as shown in FIG.3 (b), a polarizing plate uses the aqueous emulsion composition of this invention as an adhesive agent, and it is a transparent protective film to the polarizer layer 3 through the hardening layer 1 of an aqueous emulsion composition, respectively. 4 and 5 may be laminated.

  The adhesive may contain an additive. Examples of the additive include an ion trap agent, an antioxidant, a chain transfer agent, a sensitizer, a tackifier, a thermoplastic resin, a filler, a flow regulator, a plasticizer, and an antifoaming agent.

  Other films may be further laminated on the polarizing plate. Examples of other films include retardation films and brightness enhancement films. In order to laminate other films on the polarizing plate, an adhesive layer can be used in addition to the adhesive layer described above. Examples of the pressure-sensitive adhesive layer include rubbers such as acrylic polymer, silicone polymer, polyester, polyurethane, polyamide, polyvinyl ether, vinyl acetate / vinyl chloride copolymer, modified polyolefin, epoxy-based, fluorine-based, natural rubber, and synthetic rubber. A polymer having a base polymer as a base polymer can be appropriately selected and used. Various other additives may be blended in the adhesive. Examples of the additive include a silane coupling agent and an antistatic agent.

  Furthermore, by forming an adhesive layer on the polarizing plate, the polarizing plate can be laminated on a liquid crystal cell or the like to obtain a liquid crystal display device. As the pressure-sensitive adhesive layer for bonding to the liquid crystal cell, the above pressure-sensitive adhesive can be used.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not prescribed | regulated by these examples. In the examples, “%” and “part” representing the content or amount used are based on mass unless otherwise specified. The evaluation methods used in the examples are as follows.

(1) Thickness:
Measurement was performed using a digital micrometer MH-15M manufactured by Nikon Corporation.

(2) Measurement of surface tension:
The contact angle was measured using several types of wetting reagent standard solutions, and the surface tension of the substrate was determined by the Zisman plot method. The contact angle was measured using a contact angle meter OCA30L manufactured by DATA PHYSICS.

(3) Evaluation of adhesion between the primer layer and the base film (polyvinyl alcohol resin layer):
Prepare a film in which a primer layer and a polyvinyl alcohol resin layer are laminated on the base film, and use a tensile tester (“AG-IS” manufactured by Shimadzu Corporation) to prepare the base film and primer. The adhesion between the layers was measured. When the substrate film repels the liquid, the evaluation was impossible.

  At the same time, the adhesion between the polyvinyl alcohol resin layer and the primer layer was also evaluated. Specifically, the case where peeling did not occur between the polyvinyl alcohol-based resin layer and the primer layer was marked with ◯, and the case where peeling occurred was marked with x. When the substrate film repels the liquid, the evaluation was impossible.

(4) Evaluation of stability of aqueous emulsion composition:
When the aqueous emulsion composition was prepared, the case where the solid content did not precipitate in the aqueous emulsion composition was marked with ◯, and the time when the solid content precipitated was marked with x.

(5) Evaluation of liquid repellency when an aqueous emulsion composition is applied:
In (4), when solid content did not precipitate in the aqueous emulsion, the aqueous emulsion composition was applied on the base film, and the presence or absence of repelling was evaluated. In the case where no repelling occurred, it was marked as ◯, and in the case where repelling occurred, it was marked as x. When solid content precipitated in the aqueous emulsion composition, the evaluation was impossible.

  The members used in the examples were prepared as follows.

Production Example 1 Base Film Homopolypropylene (Sumitomo Chemical Co., Ltd. “Sumitomo Nobrene (registered trademark) FLX80E4”, melting point: 163 ° C.), 1 mass of nucleating agent made of high-density polyethylene, which is a homopolymer of propylene. % Blended to produce polypropylene with a nucleating agent. From this polypropylene and a propylene / ethylene random copolymer “Sumitomo Nobrene (registered trademark) W151” containing about 5% by mass of ethylene units, a long polypropylene-based laminated film is formed by coextrusion molding using a multilayer extrusion molding machine. This was used as a base film. The polypropylene-based laminated film has a three-layer structure in which the resin layer made of polypropylene containing the nucleating agent described above is disposed on both sides of the resin layer made of “Sumitomo Nobrene (registered trademark) W151”. The average thickness of the base film of Example 1 was 100 μm. The ratio of the thickness of each layer in the base film was nucleating agent-containing polypropylene: Sumitomo Nobrene (registered trademark) W151: nucleating agent-containing polypropylene = 3: 4: 3. The tensile elastic modulus in the longitudinal direction of the base film was 210 MPa. Moreover, the surface tension of the base film was 30 mN / m.

(Production Example 2) Composition for polyvinyl alcohol resin layer Polyvinyl alcohol powder (“Polyvinyl alcohol 124” manufactured by Kuraray Co., Ltd., average polymerization degree 2400, average saponification degree 98.0 mol% or more, 98.5 mol% or less) Was dissolved in 95 ° C. hot water to obtain a polyvinyl alcohol aqueous solution having a concentration of 8% by mass, which was used as a coating solution for a polyvinyl alcohol-based resin layer.

(Production Example 3) Adhesive Composition Polyvinyl alcohol powder (“KL-318” manufactured by Kuraray Co., Ltd., average polymerization degree 1800) was dissolved in hot water at 95 ° C. to obtain a polyvinyl alcohol aqueous solution having a concentration of 3 mass%. The resulting aqueous solution was mixed with a crosslinking agent (“SUMIREZ RESIN (registered trademark) 650” manufactured by Sumitomo Chemical Co., Ltd.) at a ratio of 1 part by mass with respect to 2 parts by mass of polyvinyl alcohol to obtain an adhesive composition.

[Example 1]
Aqueous polyolefin emulsion liquid adjusted to a concentration of 7.5% by water ("Hardlen (registered trademark) NZ-1004" manufactured by Toyobo Co., Ltd., containing 30% by mass of maleic anhydride-modified non-chlorinated polyolefin) Polyvinyl alcohol resin powder (“Polyvinyl alcohol 220” manufactured by Kuraray Co., Ltd., average polymerization degree 2000, average saponification degree 88 mol%) was dissolved in hot water at 95 ° C. to obtain a 4% by weight polyvinyl alcohol aqueous solution. Were mixed at room temperature to prepare an aqueous emulsion composition.

  This aqueous emulsion composition contained 5.2 parts by mass of a polyolefin-based resin and 1.5 parts by mass of a polyvinyl alcohol-based resin with respect to 100 parts by mass of water. At this time, precipitation of solid content did not occur in the aqueous emulsion composition, and no conspicuous defects were observed.

  An aqueous emulsion composition using a microgravure coater (first coating apparatus) on one side of the base film produced in Production Example 1 while continuously transporting the base film without any surface treatment. The object was applied continuously. The applied aqueous emulsion composition was dried at 90 ° C. for 3 minutes in the first drying apparatus to form a primer layer having an average thickness of 0.2 μm, thereby obtaining a laminated film.

  While continuously transporting the laminated film, the composition for the polyvinyl alcohol-based resin layer prepared in Production Example 2 was continuously applied onto the primer layer using a lip coater (second coating device). The applied polyvinyl alcohol-based resin layer composition was dried at 90 ° C. for 3 minutes using a second drying device to form a polyvinyl alcohol-based resin layer on the primer layer. In the formed polyvinyl alcohol-based resin layer, drying unevenness, peeling during transportation, and the like were not confirmed, and no defects were recognized. Thus, the laminated body which consists of a base film / primer layer / polyvinyl alcohol-type resin layer was obtained.

  The laminated body was continuously uniaxially stretched in the longitudinal direction (film transport direction) using an air-to-roll stretcher while being continuously transported. The stretching temperature was 150 ° C. The draw ratio was 5.3 times.

  The stretched laminate was immersed in a dyeing solution at 30 ° C. containing iodine and potassium iodide so that the residence time was about 150 seconds, and the polyvinyl alcohol resin layer was dyed. Next, excess dyeing solution was washed away with pure water at 10 ° C. Subsequently, a crosslinking treatment was performed by dipping in a crosslinking solution at 76 ° C. containing boric acid and potassium iodide so that the residence time was 600 seconds. Thereafter, the film was washed with pure water at 10 ° C. for 4 seconds and dried at 80 ° C. for 300 seconds to obtain a polarizing laminated film comprising a base film / primer layer / polarizer.

  While continuously transporting the polarizing laminated film, the adhesive composition prepared in Production Example 3 was applied onto the polarizer, and the saponification treatment was performed on the bonding surface (Konica) “KC4UY” manufactured by Minolta Opto Co., Ltd., having a thickness of 40 μm) was bonded and subjected to a drying treatment.

  The base film was peeled and removed from the polarizing laminate film on which the TAC film (protective film) was bonded to produce a polarizing plate comprising a primer layer / polarizer / TAC film. The average thickness of the polarizer was 4.5 μm. At this time, the peeling interface was an interface between the base film and the primer layer.

[Example 2]
Except having used the water-based emulsion composition containing 4.1 mass parts polyolefin resin and 2.0 mass parts polyvinyl alcohol-type resin with respect to 100 mass parts of water, it carried out similarly to Example 1, and using it. A polarizing plate was produced. The aqueous emulsion composition did not precipitate solids, and no noticeable defects were observed.

[Example 3]
Except having used the water-system emulsion composition containing 3.1 mass parts polyolefin resin and 2.5 mass parts polyvinyl alcohol-type resin with respect to 100 mass parts of water, it carried out similarly to Example 1, and using it. A polarizing plate was prepared. The aqueous emulsion composition did not precipitate solids, and no noticeable defects were observed.

[Example 4]
As a polyvinyl alcohol resin powder, “DM-10” (average polymerization degree 1000, average saponification degree 96.5 mol%) manufactured by Nippon Vinegar Poval Co., Ltd. is employed, and 3.1 parts per 100 parts by mass of water. A polarizing plate was produced in the same manner as in Example 1 except that an aqueous emulsion composition containing a polyolefin resin in parts by mass and a polyvinyl alcohol resin in 2.5 parts by mass was used. The aqueous emulsion composition did not precipitate solids, and no noticeable defects were observed.

[Comparative Example 1]
Except having used the water-based emulsion composition in which 2.1 mass part polyolefin resin and 3.0 mass part polyvinyl alcohol-type resin are contained with respect to 100 mass parts of water, it carried out similarly to Example 1, and using it. A polarizing plate was produced. The aqueous emulsion composition did not precipitate solids, and no noticeable defects were observed.

  After the primer layer was applied on the base film and dried, peeling occurred at the interface between the base film and the primer layer during film transport. On the other hand, no peeling occurred at the interface between the polyvinyl alcohol-based resin layer and the primer layer.

[Comparative Example 2]
Except having used the water-based emulsion composition containing 7.1 mass parts polyolefin resin and 0.5 mass parts polyvinyl alcohol-type resin with respect to 100 mass parts of water, it carried out similarly to Example 1, and using it. A polarizing plate was produced. Solid precipitation did not occur in the aqueous emulsion composition.

  When applying the aqueous emulsion composition on the base film, the surface of the base film repels the coating liquid, and a uniform coated surface could not be formed.

[Comparative Example 3]
As a polyvinyl alcohol resin powder, “JM-33” (average polymerization degree 3300, average saponification degree 94.5 mol%) manufactured by Nippon Vinegar Poval Co., Ltd. is adopted, and 3.1 parts per 100 parts by mass of water. A polarizing plate was produced in the same manner as in Example 1 except that an aqueous emulsion composition containing a polyolefin resin of part by mass and a polyvinyl alcohol resin of 2.5 parts by mass was used. In the aqueous emulsion composition, precipitation of solids occurred, and it was difficult to uniformly apply and dry to the base film, and the repelling could not be evaluated.

[Comparative Example 4]
As the polyvinyl alcohol resin powder, “Polyvinyl alcohol 124” (average polymerization degree 2400, average saponification degree 98.5 mol%) manufactured by Kuraray Co., Ltd. is employed, and 5.2 parts by mass of polyolefin with respect to 100 parts by mass of water. A polarizing plate was produced in the same manner as in Example 1 except that an aqueous emulsion composition containing a resin and 1.5 parts by mass of a polyvinyl alcohol resin was used. When applying an aqueous emulsion composition on a base film, precipitation of solid content arose, it was difficult to apply | coat and dry uniformly to a base film, and it was not able to evaluate about a repellency.

[Comparative Example 5]
Aqueous polyolefin emulsion liquid adjusted to a concentration of 7.5% by water ("Hardlen (registered trademark) NZ-1004" manufactured by Toyobo Co., Ltd., containing 30% by mass of maleic anhydride-modified non-chlorinated polyolefin) A silicone leveling agent (“BYK348” manufactured by BYK) was mixed at room temperature to prepare an aqueous emulsion composition.

  This aqueous emulsion composition contained 8.1 parts by mass of a polyolefin-based resin and 1.7 parts by mass of a silicone-based leveling agent with respect to 100 parts by mass of water. At this time, precipitation of solid content did not occur in the aqueous emulsion composition.

  A polarizing plate was produced in the same manner as in Example 1 except that this aqueous emulsion composition was used. When trying to form a polyvinyl alcohol-based resin layer on the primer layer after coating and drying, the primer layer, the polyvinyl alcohol-based resin layer, and the substrate film were moved by the silicone oil that moved to the interface between the polyvinyl alcohol-based resin layer and the primer layer. I could not get close contact with.

[Comparative Example 6]
Except having used the water-based emulsion composition containing 8.1 mass parts polyolefin resin and 1.3 mass parts silicone type leveling agent with respect to 100 mass parts of water, it carried out similarly to the comparative example 5, and was used. A polarizing plate was produced. Solid precipitation did not occur in the aqueous emulsion composition. When applying the aqueous emulsion composition on the base film, the surface of the base film repels the coating liquid, and a uniform coated surface could not be formed.

  The blending ratios of the aqueous emulsion compositions prepared in Examples 1 to 4 and Comparative Examples 1 to 6 are summarized in Table 1 below.

  The results of evaluation in Examples 1 to 4 and Comparative Examples 1 to 6 are summarized in Table 2 below.

  By adding a predetermined amount of a polyvinyl alcohol resin having an average polymerization degree of 1000 or more and less than 3300 and a saponification degree of less than 98 mol% to the aqueous emulsion composition containing a polyolefin resin, the aqueous emulsion composition is obtained. It was possible to easily apply a thin film onto a substrate film having a hydrophobic surface, and to laminate a substrate film having a hydrophobic surface and a polyvinyl alcohol resin layer having a hydrophilic surface with good adhesion.

  According to the composition of the present invention, when a thin polarizer is produced, the primer layer can be coated with a thin film, and the adhesion between the polyvinyl alcohol-based resin layer and the base film can be improved. It is useful because it can. Moreover, since it is excellent in adhesiveness as an adhesive agent for adhere | attaching a polarizer and a protective film, it is useful.

1 Hardened layer of water-based emulsion composition 2 Film (base film)
3 Polarizer layers 4 and 5 Protective film 6 Adhesive layer

Claims (4)

A polyolefin resin associated and dispersed in an aqueous medium;
A polyvinyl alcohol resin hydrated and dispersed in an aqueous medium,
The content ratio of the polyolefin-based resin with respect to 100 parts by mass of the aqueous medium is less than 30 parts by mass,
The content ratio of the polyvinyl alcohol-based resin with respect to 100 parts by mass of the aqueous medium is more than 0.5 parts by mass and less than 3 parts by mass,
The polyvinyl alcohol-based resin is an aqueous emulsion composition having an average polymerization degree of 1000 or more and less than 3300 and a saponification degree of 98 mol% or less.
A laminated film having a cured layer of the aqueous emulsion composition according to claim 1 on at least one surface of the film,
A laminated film having a critical surface tension of 50 mN / m or less on a surface in contact with the cured layer in the film.
The polarizing laminated film further equipped with the polarizer which the dichroic dye orientated to the polyvinyl alcohol-type resin on the said cured layer in the laminated film of Claim 2.
The polarizing laminated film according to claim 3, further comprising a protective film on the polarizer.

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