TW202104387A - Optical film and method of producing optical film capable of preventing peeling of a polarizer when used as a polarizing plate protective film - Google Patents

Abstract

The subject of the present invention is to provide an optical film and a method of producing an optical film, wherein the optical film may prevent peeling of a polarizer when used as a polarizing plate protective film, deterioration of the polarizer under moist and hot endurance conditions, and smoothness and turbidity deterioration (particularly internal turbidity) affecting the film transportability. The optical film of the present invention contains organic fine particles, a polymer formed by at least an alicyclic hydrocarbon monomer having a polar group, or a polymer formed by at least a (meth) acrylic monomer, characterized by containing a surfactant in the range of 0.01 to 1 ppm. The organic fine particles contain a polymer formed by at least a (meth) acrylic monomer. The solubility of the surfactant in ethanol at 23 DEG C is 0.2 to 10% by mass, the solubility in dichloromethane is less than 7% by mass, and the solubility in water is 7% by mass or more.

Description

Optical film and manufacturing method of optical film

The present invention relates to optical films and methods of manufacturing optical films, and in particular to the smoothness that can prevent the polarizer from peeling off when used as a polarizing plate protective film, or prevent the deterioration of the polarizer under damp and heat durable conditions, and the smoothness that affects the transportability of the film And the turbidity (especially the internal turbidity) deterioration of the optical film and the manufacturing method of the optical film.

Liquid crystal display devices have been widely used as display devices for televisions, notebook computers, and smart phones. A liquid crystal display device usually includes a liquid crystal cell and a pair of polarizing plates that clamp the liquid crystal cell; the polarizing plate includes a polarizer and a pair of protective films that clamp the polarizer. As such protective films, water resistance is required from the viewpoints of preventing dimensional changes due to hygroscopicity, humidity dependence of phase difference, and polarizer deterioration during damp heat durability. Therefore, as the protective film, a cycloolefin resin film or an acrylic resin film is used. In addition, it has been disclosed that fine particles are added to the film for the transportability or winding properties of the film (for example, refer to Patent Document 1).

Regarding these fine particles, when inorganic fine particles are used, they are difficult to disperse in hydrophobic resins such as cycloolefin resins due to their hydrophilicity, and the main internal haze cannot be set to the target value due to the mismatch in refractive index. Therefore, it is known to use organic fine particles instead of inorganic fine particles. For example, the technique disclosed in Patent Document 2 uses a surfactant in order to produce organic fine particles by emulsion polymerization.

On the other hand, as a method of manufacturing a film, based on the surface quality or productivity of the film, and the strength and toughness of the prescription (solvent composition, additives), a method of performing solution casting is known. However, most of the organic microparticles produced by emulsion polymerization contain surfactants. Although these surfactants are dispersed and stabilized in coatings, it has been disclosed in Patent Document 3, but it is aimed at the dope for film formation used in solution casting. ) Contained in a small amount has not been touched. When an optical film is made of cycloolefin resin or acrylic resin by solution casting, if organic fine particles are added, the content of surfactant cannot be controlled inadvertently, and there are interfaces with poor physical properties. The problem of active agents. As a result, when the aforementioned optical film is used as a polarizing plate protective film, there are problems such as peeling of the polarizer, deterioration of the polarizer under damp heat durability conditions, and deterioration of smoothness and haze that affect the transportability of the film. On the other hand, in the production of organic microparticles, surfactants are indispensable for monomer dispersion polymerization. [Prior Technical Literature] [Patent Literature]

[Patent Document 1] JP 2006-293331 A [Patent Document 2] JP 2006-233055 A [Patent Document 3] JP 2009-203378 A

[The problem to be solved by the invention]

The present invention has been accomplished in view of the above-mentioned problems and conditions. The problem to be solved is to provide an optical film and a method of manufacturing an optical film, which can prevent the polarizer from peeling off when used as a polarizer protective film, or prevent damp and heat durable conditions Deterioration of the polarizer, smoothness and haze (especially internal haze) that affect the transportability of the film. [Means to solve the problem]

In order to solve the above-mentioned problems, the inventors found that in the process of reviewing the causes of the above-mentioned problems and others, they found that before adding organic particles to the dope when the optical film is made, a treatment to remove the surfactant is carried out in advance, which can be appropriately controlled. The interfacial active dose brought into the dope or optical film can provide the dispersion and stability of organic particles, the optical film with excellent film characteristics, and the manufacturing method of the optical film, thus completing the present invention. That is, the above-mentioned problems related to the present invention can be solved by the following means.

1. An optical film containing organic microparticles, at least a polymer composed of alicyclic hydrocarbon monomers with polar groups, or at least a polymer composed of (meth)acrylic monomers, which Characteristic Contains surfactant in the range of 0.01~1ppm, The aforementioned organic microparticles contain at least a polymer composed of (meth)acrylic monomers, The solubility of the aforementioned surfactant to ethanol at 23°C is 0.2-10% by mass, the solubility to dichloromethane is less than 7% by mass, and the solubility to water is more than 7% by mass.

2. The optical film of item 1, wherein the aforementioned surfactant is an anionic surfactant.

3. The optical film of item 1 or 2, wherein the refractive index of the aforementioned polymer containing alicyclic hydrocarbon monomers with polar groups or the polymer containing (meth)acrylic monomers and the aforementioned organic microparticles The difference is 0.01 or less.

4. The optical film of any one of items 1 to 3, wherein the average particle size of the aforementioned organic particles is in the range of 10~500nm.

5. The optical film of any one of items 1 to 4, wherein the content of the aforementioned organic particles is within the range of 0.1-20% by mass relative to the total mass of the optical film.

6. A method for manufacturing an optical film, which is a method for manufacturing an optical film as in any one of items 1 to 5, and its characteristics are As the aforementioned organic fine particles, organic fine particles that have been treated to remove the surfactant present in the surroundings are used.

7. The method for manufacturing an optical film as described in item 6, wherein the organic fine particles in which the above-mentioned surfactant has been removed by alcohol in the emulsion synthesized by emulsion polymerization of the above-mentioned organic fine particles are used. [Effects of the invention]

By means of the above-mentioned means of the present invention, it is possible to prevent the polarizer from peeling off when used as a polarizing plate protective film, or to prevent the deterioration of the polarizer under damp and heat durable conditions, and the smoothness and turbidity deterioration that affect the film transportability ( Especially the internal turbidity) optical film and the manufacturing method of optical film. Although the exhibiting mechanism or action mechanism of the effect of the present invention is not clear, it is estimated as follows. When the content of the surfactant in the optical film is too much, the surfactant is aligned on the surface of the film, so the surface state of the optical film changes and the adhesion to the polarizer decreases. Moreover, it is prone to peeling off of the polarizer adhesive surface over time. In addition, since the surfactant is hydrophilic, moisture easily enters the adhesive surface with the polarizer. When water enters, since the polarizer is generally polyvinyl alcohol (PVA), the water resistance is weak. If water enters the adhesive surface under the damp and heat durable condition, it will easily cause the deterioration of the polarizer. Furthermore, if a large amount of surfactant is carried in the dope during the production of the optical film, the continuous productivity will be deteriorated due to the contamination of the steps in the production of the optical film. This is because the free surfactant in the concentrate becomes the cause of contamination. That is, the surfactant is adsorbed on the surface of the organic fine particles to a certain extent, and if excessive, it will be free from the surface of the organic fine particles. Since the surfactant has a high affinity with the surface of the cast substrate such as a metal support, it is easy to adhere to the metal support. Because of the surface of the casting substrate. In addition, the surfactant is relatively stable in a place with a low surface energy, so when it exists in a concentrated liquid, it is easy to migrate at the interface between the casting substrate such as a metal support and the film. As a result, once the surfactant adheres to the surface of the cast substrate such as a metal support, it is difficult to recover it in the dope again. Moreover, due to the solubility of the surfactant to the casting solvent, there is a problem of easy contamination. In particular, the surface active agent adheres to and accumulates on the surface of a cast substrate such as a metal support, and then transfers it to the film, which deteriorates the surface, uniformity (unevenness), and optical characteristics (haze) of the film. Become a fatal flaw. In this way, in order to remove the adhered and accumulated surfactant, it is necessary to temporarily stop the manufacturing process for cleaning, which has a problem of very poor efficiency. On the other hand, when the content of the surfactant is too small, the organic fine particles in the dope will not be dispersed stably and agglomerate, resulting in deterioration of internal turbidity and smoothness.

Therefore, in the present invention, by performing the treatment of removing the surfactant before adding the organic particles in the dope during the production of the optical film, the amount of surfactant carried in the dope or the optical film can be appropriately controlled. As a result, it is estimated that the dispersion and stability of the organic particles in the dope or the optical film will not occur, and the steps in the production of the optical film will not be contaminated, thereby providing an optical film and a manufacturing method for the optical film with excellent film characteristics.

The optical film of the present invention is an optical film containing organic fine particles, at least a polymer composed of an alicyclic hydrocarbon monomer having a polar group, or at least a polymer composed of a (meth)acrylic monomer, and is characterized by Contains a surfactant in the range of 0.01~1ppm, the aforementioned organic microparticles contain at least a polymer composed of (meth)acrylic monomers, and the solubility of the aforementioned surfactant to ethanol at 23°C is 0.2~10% by mass , The solubility of methylene chloride is less than 7 mass%, and the solubility of water is more than 7 mass%. Since the content of the surfactant is 1 ppm or less, the contamination of the casting substrate such as the metal support can be suppressed during solution casting. As a result, it is possible to prevent contamination and transfer on the surface of the film, and improve the quality as an optical film. In addition, since the surfactant content is 0.01 ppm or more, it can prevent the agglomeration of organic fine particles in the dope or film, stabilize the dispersibility of organic fine particles, and improve internal turbidity and smoothness. Furthermore, by setting the solubility of the surfactant to ethanol, dichloromethane, and water in the above range, the surfactant content can be easily controlled by cleaning and other treatments to remove the surfactant, and the metal support can be prevented Contamination of the casting substrate, and improve the dispersion of organic particles in the dope or film. This feature is a common or corresponding technical feature in the following embodiments.

As an embodiment of the present invention, in the case of the aforementioned surfactant-based anionic surfactant, it is preferable that the (meth)acrylic monomer is easily emulsified and polymerized during the production of organic fine particles.

In addition, when the refractive index difference between the aforementioned polymer containing alicyclic hydrocarbon monomer having a polar group or the polymer containing (meth)acrylic monomer and the aforementioned organic fine particles is 0.01 or less, the occurrence of internal turbidity can be suppressed The aspect is better.

The average particle size of the aforementioned organic fine particles is in the range of 10 to 500 nm. If it is 500nm or less, the unevenness of the optical film surface can be reduced and the occurrence of external haze can be suppressed, and if it is 10nm or more, the unevenness of the optical film surface can be prevented from deteriorating smoothness.

Furthermore, when the content of the aforementioned organic fine particles is in the range of 0.1 to 20% by mass relative to the total mass of the optical film, it becomes an appropriate addition amount, which is preferable in terms of preventing the occurrence of turbidity and improving smoothness.

The method for producing an optical film of the present invention is a method of producing a polymer composed of at least an alicyclic hydrocarbon monomer having a polar group or a polymer composed of at least a (meth)acrylic monomer containing organic microparticles The method of the optical thin film is characterized by using organic fine particles that have been treated to remove the surfactant present in the surroundings as the aforementioned organic fine particles. By this, the amount of interface active in the dope or the optical film can be appropriately controlled, without polluting the steps in the production of the optical film, and the optical film with excellent film characteristics can be manufactured.

In addition, when used in the emulsion synthesized by the emulsion polymerization of the organic particles, when the organic particles after the surfactant are removed by alcohol, the ability to remove the surfactant attached to the surface of the organic particles is better than that of water. good. That is, the surfactant is attached to the surface of the organic particles through the hydrophobic group. Compared with the hydrophilic group acting on the opposite side of the surfactant in the water system, the alcohol can also act on the hydrophobic group attached to the organic particles. The removal capacity is relatively large.

Hereinafter, the present invention, its constituent elements, and the modes and aspects for implementing the present invention will be described. In addition, in this application, "~" is used to include the numerical value described before and after it as the lower limit and the upper limit.

[Optical Film] The optical film of the present invention is an optical film containing organic fine particles, at least a polymer composed of an alicyclic hydrocarbon monomer having a polar group, or at least a polymer composed of a (meth)acrylic monomer, and is characterized by Contains a surfactant in the range of 0.01~1ppm, the aforementioned organic microparticles contain at least a polymer composed of (meth)acrylic monomers, and the solubility of the aforementioned surfactant to ethanol at 23°C is 0.2~10% by mass , The solubility of methylene chloride is less than 7 mass%, and the solubility of water is more than 7 mass%.

＜Surface active agent＞ The surfactant of the present invention is contained in the optical film in the range of 0.01 to 1 ppm. That is, the surfactant is used for the emulsion polymerization of the aforementioned organic fine particles, and is contained in the optical film in the range of 0.01 to 1 ppm by the removal method described later or the appropriate selection of the type of surfactant. As the surfactant, surfactants such as anionic surfactants, cationic surfactants, zwitterionic surfactants, and nonionic surfactants can be used. Examples of anionic surfactants include fatty acid oils such as sodium oleate and castor oil base, sodium lauryl sulfate, ammonium lauryl sulfate and other alkyl sulfate ester salts, sodium lauryl sulfonate and other alkyl benzene sulfonates Acid salt, alkyl sulfonate, alkyl naphthalene sulfonate, alkane sulfonate, succinate sulfonate, dialkyl sulfosuccinate, alkyl phosphate ester salt, naphthalene sulfonate formaldehyde condensate, poly Oxyethylene alkyl phenyl ether sulfate, polyoxyethylene alkyl sulfate, etc.

Examples of nonionic surfactants include polyoxyethylene alkyl ethers, polyoxyethylene alkyl phenyl ethers, polyoxyethylene fatty acid esters, sorbitan fatty acid esters, polyoxysorbitan fatty acid esters, Polyoxyethylene alkylamine, glycerin fatty acid ester, oxyethylene-oxypropylene block polymer, etc.

Examples of cationic surfactants include alkylamine salts such as laurylamine acetate and stearylamine acetate, and quaternary ammonium salts such as lauryltrimethylammonium chloride. Examples of zwitterionic surfactants include lauryl dimethylamine oxide, phosphate ester-based or phosphite-based surfactants. These surfactants may be used alone or in combination of two or more kinds. In particular, in the present invention, in the case of the aforementioned anionic surfactant, it is preferable that the (meth)acrylic monomer is easily emulsified and polymerized when the organic fine particles are produced.

The solubility of the aforementioned surfactant to ethanol at 23° C. is in the range of 0.2 to 10% by mass, preferably in the range of 0.5 to 5% by mass. If the aforementioned solubility is 0.2% by mass or more, the cleaning efficiency when cleaning organic fine particles is good, and it is easy to control the surfactant content. If the aforementioned solubility is 10% by mass or less, it will not dissolve too much in ethanol, and the occurrence of contamination of casting substrates such as metal supports can be prevented. That is, when the dope is dried on a cast base material such as a metal support, methylene chloride with a low boiling point is likely to volatilize from the surface of the dope. Therefore, a concentration gradient of ethanol/dichloromethane can be generated in the thickness direction of the dope, so that the side of the casting substrate of the metal support and the like becomes rich in ethanol. When the ethanol solubility of the active agent is large, the active agent tends to exist in the ethanol-rich part on the casting substrate side of the metal support, so it will adhere and accumulate on the casting substrate such as the metal support and become contaminated. When the solubility is below the above, the active agent will not be biased, and the contamination of the casting substrate such as the metal support can be prevented. The solubility of the aforementioned surfactant in dichloromethane at 23° C. is less than 7% by mass, and preferably within the range of 3% by mass. When the aforementioned solubility is less than 7% by mass, by dispersing the surfactant with water-containing dichloromethane, the active agent can be removed by phase separation. In addition, it does not dissolve too much in methylene chloride, which is the main solvent of the dope, so that the dispersion of organic fine particles is good. The solubility of the aforementioned surfactant in water at 23° C. is 7% by mass or more, preferably within the range of 9% by mass. When the aforementioned solubility is 7% by mass or more, an emulsion can be appropriately prepared during emulsion polymerization. In addition, the cleaning efficiency of the surfactant when cleaning organic particles is good, and the content of the surfactant is easy to control. Since the surfactant is hydrolyzed by heating and humidification, the surfactant is finally dissolved in water due to its solubility in water and can be decomposed by the moisture adsorbed on the surface. As above, it is important to balance the solubility of the surfactant in ethanol, dichloromethane and water.

The aforementioned surfactant content is measured by first freeze-drying the optical film, pulverizing, ultrasonic extraction with methanol, centrifugal separation, and drying the methanol soluble fraction to determine the quality of the dry solid. Subsequently, the above-mentioned dry solid was dissolved in deuterated methanol added with 1,4-bis(trimethylsilyl)benzene-d4 as an internal standard, and the above-mentioned dissolved solution was used with NMR device: ECZ-400S (JEOL (400MHz manufactured by RESONANCE), measured under the following conditions, and calculated the surfactant content from the proton intensity derived from the surfactant structure and the internal standard intensity. Observation core: 1H Pulse width: 5.6μs (45° pulse) Pulse delay time: 15s The cumulative number of determinations: 64 times

The solubility of the aforementioned surfactant is visually judged by dissolving in various solvents at 23°C. Specifically, for example, for 100g of water at 23°C, a small amount of surfactant is added successively, 10.0g is dissolved, and insoluble matter is observed in 10.1g, and the solubility in water is 10/(100+10)=9.1 mass %.

＜Organic particles＞ The organic fine particles of the present invention have the function of imparting smoothness to the optical film during the production of the optical film after being subjected to the removal treatment of the surfactant as described later. The organic microparticles of the present invention are preferably particles (polymer particles) composed of polymers containing structural units derived from (meth)acrylic monomers, and the organic microparticles may be rubber-like (rubber particles) or It is non-rubbery. By becoming rubber particles, in the case of a film containing a polymer made of a (meth)acrylic monomer that is brittle and breakable, it can be given soft flexibility. In addition, the term “rubbery” in the present invention refers to a state in which the material is significantly elongated or contracted before the material is broken when a stress greater than the strength of a certain material is applied.

The organic fine particles of the present invention preferably have a core/shell structure (multilayer structure). The core/shell structure can be a two-layer structure consisting of a core layer and a shell layer, or a three-layer structure of core layer/middle layer/shell layer, and a three-layer structure of seed particle layer/core layer/shell layer. However, the shell layer is the outermost layer. When the content of the organic fine particles of the present invention is in the range of 0.1 to 20% by mass relative to the total mass of the optical film, it can be an appropriate content, and it is preferable to have both turbidity and smoothness.

When the difference in refractive index between the organic fine particles of the present invention and the polymer containing alicyclic hydrocarbon monomer having a polar group or the polymer containing (meth)acrylic monomer described later is 0.01 or less, the occurrence of internal turbidity can be suppressed This aspect is preferable, and it is more preferably in the range of 0 to 0.005. As a method for satisfying the above-mentioned refractive index conditions, for example, adjusting the unit composition ratio of the aforementioned polymers containing alicyclic hydrocarbon monomers with polar groups or polymers containing (meth)acrylic monomers The method, and/or the method of adjusting the composition ratio of the polymer and/or monomer used in the organic microparticles, etc.

(Measurement method of refractive index difference) First, with regard to organic fine particles, the organic fine particles are press-molded, and the average refractive index of the molded body is measured with a laser refractometer, and this value is taken as the refractive index of the organic fine particles. Similarly, for a polymer containing an alicyclic hydrocarbon monomer having a polar group or a polymer containing a (meth)acrylic monomer, the polymer is formed, and the average refractive index of the formed body is measured with a laser refractometer, Set this value as the refractive index of the aforementioned polymer. The difference between the refractive index values of the aforementioned polymer and the organic fine particles measured by the above-mentioned measurement is calculated, and thereby the refractive index difference can be obtained. In this embodiment, the term “refractive index” refers to the refractive index of light with a wavelength of 550 nm at 23°C.

The organic fine particles of the present invention preferably have an average particle size in the range of 10 to 500 nm, more preferably in the range of 80 to 200 nm. If it is 500nm or less, the unevenness on the surface of the optical film can be reduced. The occurrence of external haze can be suppressed, and if it is 10 nm or more, it is possible to prevent deterioration of smoothness by making the surface irregularities of the optical film.

(Measurement method of average particle size) The aforementioned average particle size can be determined by, for example, a dynamic light scattering method using MICROTRAC UPA150 (manufactured by Nikkiso Co., Ltd.).

The organic fine particles are preferably particles (polymer particles) composed of polymers containing structural units derived from (meth)acrylic monomers. Examples of (meth)acrylic monomers include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, butyl (meth)acrylate, ethylene glycol bis(methyl) ) (Meth)acrylates such as acrylate, trimethylolpropane tri(meth)acrylate, etc. Among them, methyl (meth)acrylate or ethylene glycol di(meth)acrylate is preferred. In addition, the so-called (meth)acrylic acid means acrylic acid or methacrylic acid. The content rate of the structural unit derived from the (meth)acrylic monomer in the polymer containing the structural unit derived from the (meth)acrylic monomer is relative to 100% by mass of the total structural unit of the constituting polymer , Preferably 20 to 99% by mass, more preferably 30 to 90% by mass, and still more preferably 50 to 90% by mass.

The polymer containing structural units derived from (meth)acrylic monomers may further contain structural units derived from other monomers that can be copolymerized with (meth)acrylic monomers as needed. Examples of other monomers include itaconic acid diesters, maleic acid diesters, vinyl esters, olefins, styrenes, (meth)acrylamides, allyl compounds, and vinyl ethers , Vinyl ketones, unsaturated nitriles and unsaturated carboxylic acids.

Examples of diesters of itaconic acid include dimethyl itaconic acid, diethyl itaconic acid, dipropyl itaconic acid, and the like. Examples of maleic acid diesters include dimethyl maleate, diethyl maleate, dipropyl maleate, and the like. Examples of vinyl esters include vinyl acetate, vinyl propionate, vinyl butyrate, vinyl isobutyrate, vinyl caproate, vinyl chloroacetate, methoxy vinyl acetate, phenyl vinyl acetate, Vinyl benzoate, vinyl salicylate, etc. Examples of olefins include dicyclopentadiene, ethylene, propylene, 1-butene, 1-pentene, vinyl chloride, vinylidene chloride, isoprene, chloroprene, butadiene, 2, 3-Dimethylbutadiene and so on. Examples of styrenes include styrene, methyl styrene, dimethyl styrene, trimethyl styrene, ethyl styrene, isopropyl styrene, chloromethyl styrene, methoxy styrene, ethylene Acetoxy styrene, chlorostyrene, dichlorostyrene, bromostyrene, trifluoromethyl styrene, methyl vinyl benzoate, divinyl benzene, etc. Examples of (meth)acrylamides include (meth)acrylamide, methyl(meth)acrylamide, ethyl(meth)acrylamide, propyl(meth)acrylamide, butyl (Meth)acrylamide, tert-butyl(meth)acrylamide, phenyl(meth)acrylamide, dimethyl(meth)acrylamide, methylenebisacrylamide, etc. . Examples of allyl compounds include allyl acetate, allyl hexanoate, allyl laurate, allyl benzoate, and the like. Examples of vinyl ethers include methyl vinyl ether, butyl vinyl ether, hexyl vinyl ether, methoxyethyl vinyl ether, dimethylaminoethyl vinyl ether, and the like. Examples of vinyl ketones include methyl ketene, phenyl ketene, and methoxy ethyl ketene. Examples of unsaturated nitriles include acrylonitrile, methacrylonitrile and the like. Examples of unsaturated carboxylic acids include (meth)acrylic acid, itaconic acid, itaconic acid monoester, maleic acid, maleic acid monoester, and the like.

Among them, from the viewpoint of good affinity with cycloolefin resins, other monomers are preferably selected from at least one of the group consisting of vinyl esters, styrenes, and olefins, and more preferably styrenes . That is, the polymer containing structural units derived from (meth)acrylic monomers preferably includes a copolymer of structural units derived from (meth)acrylates and structural units derived from styrenes. Particles (polymer particles) made of such polymers are produced by any method such as emulsion polymerization, suspension polymerization, dispersion polymerization, seed polymerization and the like. Among them, from the viewpoint that it is easy to obtain polymer particles of uniform particle size, etc., seed polymerization or emulsion polymerization in an aqueous medium is preferred.

As an example of the manufacturing method of the aforementioned polymer particles ･One-stage polymerization method in which the monomer mixture is dispersed in an aqueous medium and then polymerized. ･The two-stage polymerization method in which the monomer is polymerized in an aqueous medium to obtain seed particles, and then the monomer mixture is absorbed in the seed particles and polymerized. ･Multi-stage polymerization method that repeats the steps of two-stage polymerization method to produce seed particles. These polymerization methods can be appropriately selected corresponding to the desired average particle diameter of the polymer particles. In addition, the monomer for producing seed particles is not particularly limited, and any monomer for polymer particles can be used.

As the emulsifier for emulsion polymerization, surfactants such as the aforementioned anionic surfactants, cationic surfactants, zwitterionic surfactants, and nonionic surfactants can be used. These emulsifiers can be used singly or in combination of two or more, but the diameter of the obtained particles and the dispersion stability during polymerization are considered, and the emulsifier is selected or the amount used is adjusted appropriately.

The organic microparticles can be particles with a core/shell structure. Examples of these organic microparticles include core/shell particles having a low Tg core layer and a high Tg shell layer containing a homopolymer or copolymer of (meth)acrylate. The aforementioned core/shell particles preferably have a structure derived from a polyfunctional compound only in the central part (core), and the part (shell) surrounding the central part has a structure with high compatibility with the resin constituting the optical film. Thereby, the organic fine particles can be more uniformly dispersed in the resin, and the by-generation of foreign substances due to agglomeration of the organic fine particles can be more suppressed. The following describes the shell and core of the above-mentioned core/shell structure.

＜＜Shell part＞＞ The shell part is not particularly limited as long as it has a structure with high compatibility with the resin constituting the optical film.

＜＜Core＞＞ The core is not particularly limited as long as it exhibits an effect of improving the flexibility of the resin constituting the optical film, and it is exemplified by a structure having crosslinking. In addition, the crosslinked structure is preferably a crosslinked rubber structure. The aforementioned cross-linked rubber structure refers to a rubber structure with a polymer whose glass transition point is in the range of -100°C to 25°C as the main chain, and multifunctional compounds are used to cross-link between the main chains to make it elastic. . Examples of cross-linked rubber structures include acrylic rubber, polybutadiene rubber, and olefin rubber structures (repeating structural units). Among these, since the average particle diameter is easily controlled to 0.3 μm or less, and the optical properties such as transparency of the film when uniformly dispersed in the resin are good, acrylic rubber is preferred.

As a method for synthesizing the aforementioned core/shell type organic microparticles, any appropriate method that can synthesize core/shell type organic microparticles can be used. An example is suspension or emulsion polymerization of polymerizable monomers that form the rubbery polymer that constitutes the core layer to produce a suspension or emulsified dispersion containing rubbery polymer particles, and then add to the suspension or emulsified dispersion to form a structure The polymerizable monomer of the glassy polymer of the shell layer undergoes radical polymerization to obtain a core/shell type elastomer with a multilayer structure in which the surface of the rubbery polymer particles is coated with the glassy polymer. Here, the polymerizable monomer forming the rubber-like polymer and the polymerizable monomer forming the glass-like polymer may be polymerized in one stage, or may be polymerized in two or more stages by changing the composition ratio.

<Polymers containing alicyclic hydrocarbon monomers with polar groups> As the polymer containing an alicyclic hydrocarbon monomer having a polar group (also referred to as a cycloolefin resin having a polar group) contained in the optical film of the present invention, it preferably contains norbornene derived from a polar group It is a polymer that is the structural unit of a monomer.

Examples of polar groups include carboxyl groups, hydroxyl groups, alkoxycarbonyl groups, allyloxycarbonyl groups, amino groups, amide groups, cyano groups, and groups in which these groups are bonded via a linking group such as methylene groups, through carbonyl groups, ether groups, etc. , Silyl ether group, thioether group, imine group and other polar divalent organic groups as a linking group to form a hydrocarbon group. Among these, a carboxyl group, a hydroxyl group, an alkoxycarbonyl group, or an allyloxycarbonyl group is preferable, and the alkoxycarbonyl group or allyloxycarbonyl group is particularly preferable in terms of ensuring the solubility during film formation from a solution.

The norbornene-based monomer having a polar group is preferably a norbornene-based monomer represented by the following formula (A-1) or (A-2).

^{R 1} and R ^{2 in the} formula (A-1) each represent a hydrogen atom, a hydrocarbon group with 1 to 5 carbon atoms, or a polar group. However, ^{at least one of R 1} and R ² is a polar group.

Examples of hydrocarbon groups having 1 to 5 carbon atoms include alkyl groups having 1 to 5 carbon atoms such as methyl, ethyl, propyl, and butyl.

In formula (A-1), p represents an integer of 0-2. From the viewpoint of improving the heat resistance of the optical film, p is preferably 1 to 2. This is because when p is 1 to 2, the volume of the obtained resin becomes larger and the glass transition temperature is easily increased.

The norbornene-based monomer represented by the formula (A-2) has low molecular symmetry, so it is easy to promote the resin diffusion movement when the solvent of the cycloolefin-based resin with a polar group is volatilized.

^{R 3} and R ^{4 in the} formula (A-2) each represent a hydrogen atom, a hydrocarbon group with 1 to 5 carbon atoms, or a polar group. However, ^{at least one of R 3} and R ⁴ is a polar group. Polar group and hydrocarbon group with 1 to 5 carbons are synonymous with the polar group of formula (A-1) and hydrocarbon group with 1 to 5 carbons respectively

The p in the formula (A-2) has the same meaning as the p in the formula (A-1).

Examples of the norbornene-based monomer having a polar group include the following compounds.

The content ratio of the constituent units derived from the norbornene-based monomer having a polar group is, for example, 50 mol% or more, preferably 70 mol% or more, more preferably 100 mol% relative to all the constituent units constituting the cycloolefin-based resin ear%. When the constituent unit derived from a norbornene-based monomer having a polar group contains more than a certain amount, the polarity of the resin is likely to increase, and the cycloolefin-based resin can be easily dissolved in a solvent, so it is easier to manufacture by the solution film method (casting method) membrane.

In the cycloolefin resin, in addition to the structural unit derived from the norbornene-based monomer having a polar group, it may further contain a norbornene-based monomer derived from the norbornene-based monomer having no polar group or can be combined with the norbornene-based monomer having a polar group. The structural unit of monomers copolymerized with ethylenic monomers.

Norbornene-based mono-system without polar groups In the aforementioned formula (A-1), R ¹ and R ² are respectively a hydrogen atom, a hydrocarbon group with 1 to 5 carbon atoms or a halogen atom, or the aforementioned formula (A-2 In ), R ³ and R ⁴ are each a hydrogen atom, a hydrocarbon group with 1 to 5 carbon atoms, or a halogen atom.

Examples of norbornene-based monomers that do not have a polar group include the following compounds.

Examples of monomers that can be copolymerized with norbornene-based monomers having polar groups include monomers that can be ring-opened copolymerized with norbornene-based monomers having polar groups or monomers that can be copolymerized with norbornene-based monomers having polar groups. Monomer addition copolymerization monomer.

Examples of monomers that can be ring-opened and copolymerized with norbornene-based monomers having polar groups include other cycloolefin monomers such as cyclobutene, cyclopentene, cycloheptene, cyclooctene, and dicyclopentadiene .

Examples of monomers that can be addition copolymerized with norbornene-based monomers having polar groups include unsaturated double bond-containing compounds, vinyl-based cyclic hydrocarbon compounds, and (meth)acrylates. Examples of compounds containing unsaturated double bonds include cycloolefin compounds having 2 to 12 carbon atoms (preferably 2 to 8), and examples thereof include ethylene, propylene, and butene. Examples of vinyl-based cyclic hydrocarbon compounds include vinylcyclopentene-based monomers such as 4-vinylcyclopentene and 2-methyl-4-isopropenylcyclopentene. Examples of (meth)acrylates include methyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, cyclohexyl (meth)acrylate, etc. (meth)acrylic acid having carbon atoms of 1~ 20 alkyl esters.

Cycloolefin resins with polar groups are homopolymers of norbornene monomers represented by formula (A-1) or (A-2) or copolymers with other monomers. Examples are the following, Preferred are (1) to (3) and (5), and more preferred are (3) and (5). (1) Ring-opening polymer of norbornene-based monomer represented by formula (A-1) or (A-2) (2) Ring-opening copolymer of norbornene-based monomer represented by formula (A-1) or (A-2) and other monomers (3) Hydrogenated (co)polymer of the ring-opening (co)polymer of (1) or (2) above (4) The ring-opening (co)polymer of (1) or (2) above is cyclized by the Friedel-Craft reaction and then hydrogenated (co)polymer (5) Copolymers of norbornene-based monomers represented by formula (A-1) or (A-2) and compounds containing unsaturated double bonds (6) The addition type (co)polymer of norbornene-based monomer represented by formula (A-1) or (A-2) and its hydrogenated (co)polymer (7) Alternating copolymer of norbornene-based monomer represented by formula (A-1) or (A-2) and methacrylate or acrylate

Examples of the cycloolefin resin having a polar group include at least one of the structural units represented by the following formula (B-1) or (B-2). Among them, from the viewpoint that it is easy to increase the glass transition temperature of the cycloolefin resin having a polar group and to obtain an optical film with high transmittance, a homopolymer containing the structural unit represented by the formula (B-2) or having the formula (B-2) The copolymer of the structural unit and the structural unit derived from other monomers.

X in the formula (B-1) is a group represented by -CH=CH- or a group represented by -CH ₂ CH ₂ -. R ^1, R ² and p are respectively of formula (A-1) of R ^1, R ² and p are synonymous.

X in the formula (B-2) is a group represented by -CH=CH- or a group represented by -CH ₂ CH ₂ -. R of formula (B-2) of the ^3, R ⁴ and p are the same as R of formula (A-2) of the ^3, R ⁴ and p are synonymous.

The cycloolefin resin having a polar group may be used singly, or two or more of them may be used in combination.

The value of SP (Solubility Parameter; solubility parameter) of cycloolefin resin with polar group is 16.5~17.5.

The SP value of the cycloolefin resin with a polar group is calculated by the Bicerano method based on the regression equation obtained by statistically analyzing the correlation between the molecular structure and the physical property value of the polymer material. Specifically, the software "Scigress Version 2.6" (manufactured by Fujitsu) installed in a commercially available personal computer is used, and the structure of the compound is substituted into the value calculated by the Bicerano method.

The intrinsic viscosity [η]inh of the cycloolefin resin having a polar group is, for example, 0.2 to 5 cm ³ /g, preferably 0.3 to 3 cm ³ /g, and more preferably 0.4 to 1.5 cm ³ /g. The weight average molecular weight (Mw) of the cycloolefin resin is, for example, 20,000 to 300,000, more preferably 30,000 to 250,000, and still more preferably 40,000 to 200,000. The weight average molecular weight (Mw) can be measured by gel permeation chromatography (GPC) in terms of polystyrene.

If the intrinsic viscosity [η]inh and the weight average molecular weight are within the above range, the cycloolefin resin having a polar group has good heat resistance, water resistance, chemical resistance, mechanical properties, and forming processability as a film.

The glass transition temperature (Tg) of the cycloolefin resin having a polar group is usually above 110°C, preferably 110~350°C, more preferably 120~250°C, particularly preferably within the range of 120~220°C. The case where the Tg is 110°C or higher is preferable because it is not easily deformed due to use under high temperature conditions or secondary processing such as coating and printing. On the other hand, when the Tg is 350°C or less, difficult molding processing can be avoided, and the possibility of resin deterioration due to heat during molding processing can be suppressed.

In addition, the cycloolefin resin having a polar group can preferably use a commercially available product. As an example of a commercially available product, it can be selected from JSR (Stock), ARTON (registered trademark) G, ARTON F, ARTON R, and ARTON RX. Such as trade name sales.

<Polymer containing (meth)acrylic monomer> Examples of polymers containing (meth)acrylic monomers (also referred to as acrylic resins) contained in the optical film of the present invention include poly(meth)acrylates such as polymethylmethacrylate, methyl Methyl acrylate-(meth)acrylic acid copolymer, methyl methacrylate-(meth)acrylate copolymer, methyl methacrylate-acrylate-(meth)acrylic acid copolymer, (meth)acrylic acid copolymer Ester-styrene copolymer (MS resin, etc.), polymers with alicyclic hydrocarbon groups (e.g. methyl methacrylate-cyclohexyl methacrylate copolymer, methyl methacrylate-(meth)acrylic norbornyl) Ester copolymer, etc.). In more detail, it is a resin that is homopolymerized or copolymerized from an arbitrarily selected combination of monomers and the like described below, and then subjected to a cyclization reaction, dehydration condensation reaction, hydrogenation reaction, protective functional group detachment reaction, etc. Among the reacted resins, those containing (meth)acrylate at a weight ratio of more than 50%.

(Single species) Examples of the aforementioned monomers are methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, ( Second butyl meth)acrylate, third butyl (meth)acrylate, n-pentyl (meth)acrylate, second pentyl (meth)acrylate, third pentyl (meth)acrylate, (meth)acrylate, (meth)acrylate, (meth)acrylate, (meth)acrylate, (meth)acrylate, (meth)acrylate, (meth)acrylate, (meth)acrylate, (meth)acrylate, (meth)acrylate, (meth)acrylate, (meth)acrylate, (meth)acrylate, (meth)acrylate, (meth)acrylate, (meth)acrylate, (meth)acrylate, (meth)acrylate, (meth)acrylate Base) n-hexyl acrylate, 2-ethylhexyl (meth)acrylate, isodecyl (meth)acrylate, tridecyl (meth)acrylate, cyclohexyl (meth)acrylate, (meth) Cyclohexyl methyl acrylate, octyl (meth)acrylate, lauryl (meth)acrylate, stearyl (meth)acrylate, benzyl (meth)acrylate, phenyl (meth)acrylate, (meth)acrylate ) Isobornyl acrylate, adamantyl (meth)acrylate, tricyclodecyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, (methyl) ) 3-hydroxypropyl acrylate, 2-hydroxybutyl (meth)acrylate, 3-hydroxybutyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 2-methoxy (meth)acrylate Ethyl ester, 2-ethoxyethyl (meth)acrylate, phenoxyethyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, glycidyl (meth)acrylate, (methyl) ) Β-methyl glycidyl acrylate, β-ethyl glycidyl (meth)acrylate, (3,4-epoxycyclohexyl) methyl (meth)acrylate, N,N (meth)acrylate -(Meth)acrylates such as dimethylaminoethyl, α-hydroxymethyl methacrylate, α-hydroxyethyl methacrylate, etc.

Isobutyl methacrylate, 2-methylbutyl methacrylate, 2-ethylbutyl methacrylate, 2-isopropylbutyl methacrylate, 2-isopropyl-4-methyl methacrylate Methyl butyl ester, 2,3-dimethylbutyl methacrylate, 2-methylpentyl methacrylate, 2-ethylpentyl methacrylate, 2-propylpentyl methacrylate, methacrylic acid 2-isopropylpentyl ester;

Second butyl methacrylate, 1-methylbutyl methacrylate, 1-methylpentyl methacrylate, 1,3-dimethylbutyl methacrylate, 1,2-dimethyl methacrylate Propyl acrylate, 1,2-dimethylbutyl methacrylate, 1,2-dimethylpentyl methacrylate, 1,2,3-trimethylbutyl methacrylate, 2-methacrylate Ethyl-1-methylbutyl ester, 2-ethyl-1-methylpentyl methacrylate, 2-ethyl-1,3-dimethylbutyl methacrylate, 1-methyl methacrylate -2-propylpentyl ester, 2-isopropyl-1-methylpentyl methacrylate, 2-isopropyl-1,3-dimethylbutyl methacrylate, 1-ethyl methacrylate Propyl ester, 1-ethylbutyl methacrylate, 1-ethylpentyl methacrylate, 1-ethyl-3-methylbutyl methacrylate, 1-ethyl-2-methyl methacrylate Propyl ester, 1-ethyl-2-methylbutyl methacrylate, 1-ethyl-2-methylpentyl methacrylate, 1-ethyl-2,3-dimethylbutyl methacrylate , 1,2-diethylbutyl methacrylate, 1,2-diethylpentyl methacrylate, 1,2-diethyl-3-methylbutyl methacrylate, 1-methacrylate Ethyl-2-propylpentyl ester, 2-isopropyl-1-ethylpentyl methacrylate, 1-ethyl-2-isopropyl-3-methylbutyl methacrylate, methacrylic acid 1-propyl butyl ester;

1-propylpentyl methacrylate, 3-methyl-1-propylbutyl methacrylate, 1-isopropylbutyl methacrylate, 2-methyl-1-propylbutyl methacrylate , 2-methyl-1-propylpentyl methacrylate, 2,3-dimethyl-1-propylbutyl methacrylate, 2-ethyl-1-propylbutyl methacrylate, methyl methacrylate 2-ethyl-1-propylpentyl acrylate, 2-ethyl-3-methyl-1-propylbutyl methacrylate, 1,2-dipropylpentyl methacrylate, methacrylic acid 2-isopropyl-1-propylpentyl ester, 2-isopropyl-3-methyl-1-propylbutyl methacrylate, 1-isopropylpentyl methacrylate, 1-isopropyl methacrylate Isopropyl-3-methylbutyl ester, 1-isopropyl-2-methylpropyl methacrylate, 1-isopropyl-2-methylbutyl methacrylate, 1-isopropyl methacrylate 2-methylpentyl ester, 1-isopropyl-2,3-dimethylbutyl methacrylate, 2-ethyl-1-isopropylbutyl methacrylate, 2-ethyl methacrylate 1-isopropylpentyl methacrylate, 2-diethyl-1-isopropyl-3-methylbutyl methacrylate, 1-isopropyl-2-propylpentyl methacrylate, methyl 1,2-Diisopropylpentyl acrylate, 1,2-Diisopropyl-3-methylbutyl methacrylate;

Tert-butyl methacrylate, 1,1-dimethylpropyl methacrylate, 1-ethyl-1-methylpropyl methacrylate, 1,1-diethylpropyl methacrylate, methyl methacrylate 1,1-dimethylbutyl methacrylate, 1-ethyl-1-methylbutyl methacrylate, 1,1-diethylbutyl methacrylate, 1-methyl-1-methacrylate Propyl butyl ester, 1-ethyl-1-propyl butyl methacrylate, 1,1-dipropyl butyl methacrylate, 1,1,2-trimethylpropyl methacrylate, methyl 1-ethyl-1,2-dimethylpropyl acrylate, 1,1-diethyl-2-methylpropyl methacrylate, 1-isopropyl-1-methylbutyl methacrylate, 1-ethyl-1-isopropylbutyl methacrylate, 1-isopropyl-1-propylbutyl methacrylate, 1-isopropyl-1,2-dimethylpropyl methacrylate , 1,1-diisopropylpropyl methacrylate, 1,1-diisopropylbutyl methacrylate, 1,1-diisopropyl-2-methylpropyl methacrylate;

4-methylcyclohexyl methacrylate, 2-methylcyclohexyl methacrylate, 4-isopropylcyclohexyl methacrylate, 2-isopropylcyclohexyl methacrylate, 4 -Tert-butylcyclohexyl, 2-tert-butylcyclohexyl methacrylate;

2-Norbornyl methacrylate, 2-Methyl-2-norbornyl methacrylate, 2-Ethyl-2-norbornyl methacrylate, 2-Isobornyl methacrylate, 2 -Methyl-2-isobornyl ester, 2-ethyl-2-isobornyl methacrylate, 8-tricyclo[5.2.1.0 ^2,6 ]decyl methacrylate, 8-methyl methacrylate 8-tricyclo[5.2.1.0 ^2,6 ]decyl ester, 8-ethyl-8-tricyclo[5.2.1.0 ^2,6 ]decyl methacrylate, 2-adamantyl methacrylate, methacrylic acid 2-Methyl-2-adamantyl ester, 2-ethyl-2-adamantyl methacrylate, 1-adamantyl methacrylate, 2-fenchyl methacrylate, methacrylic acid 2 -Methyl-2-fenchyl ester, 2-ethyl-2-fenchyl methacrylate, decalin-1-yl methacrylate, decalin-2-yl methacrylate, etc.

(Copolymerizable monomer) Examples of copolymerizable monomers include (meth)acrylamides such as N,N-dimethyl (meth)acrylamide, N-methylol (meth)acrylamide, etc.; (methyl) ) Unsaturated monocarboxylic acids such as acrylic acid, crotonic acid, cinnamic acid and vinyl benzoic acid; unsaturated polycarboxylic acids such as maleic acid, fumaric acid, itaconic acid, citraconic acid and mesaconic acid Acids; succinic acid mono(2-propenoxyethyl), succinic acid mono(2-methacryloxyethyl), etc. Unsaturated monocarboxylic acids with chain extension between unsaturated group and carboxyl group ;Unsaturated acid anhydrides such as maleic anhydride and itaconic anhydride; styrene, α-methylstyrene, α-chlorostyrene, p-tertiary butyl styrene, p-methylstyrene, p-chloro Aromatic vinyls such as styrene, o-chlorostyrene, 2,5-dichlorostyrene, 3,4-dichlorostyrene, vinyl toluene, methoxystyrene, etc.; methyl maleate Amine, ethyl maleimide, isopropyl maleimide, cyclohexyl maleimide, phenyl maleimide, benzyl maleimide, naphthyl maleimide N-substituted maleimines; 1,3-butadiene, isoprene, chloroprene and other conjugated dienes; vinyl acetate, vinyl propionate, vinyl butyrate, Vinyl esters such as vinyl benzoate; methyl vinyl ether, ethyl vinyl ether, propyl vinyl ether, butyl vinyl ether, 2-ethylhexyl vinyl ether, n-nonyl vinyl ether , Lauryl vinyl ether, cyclohexyl vinyl ether, methoxy ethyl vinyl ether, ethoxy ethyl vinyl ether, methoxy ethoxy ethyl vinyl ether, methoxy polyethylene glycol Vinyl ether, 2-hydroxyethyl vinyl ether, 4-hydroxybutyl vinyl ether and other vinyl ethers; N-vinylpyrrolidone, N-vinyl caprolactam, N-vinylimidazole , N-vinylmorpholine, N-vinylacetamide and other N-vinyl compounds; (meth)acrylate isocyanatoethyl, allyl isocyanate and other unsaturated isocyanates; acrylonitrile, Vinyl cyanide such as methacrylonitrile; etc.

(Method of manufacturing acrylic resin) As a method for producing the acrylic resin of the present invention, generally performed polymerization methods such as casting polymerization, bulk polymerization, suspension polymerization, solution polymerization, emulsion polymerization, and anionic polymerization can be used. Among them, bulk polymerization or solution polymerization that does not use a suspending agent or emulsifier is preferable because it can reduce the mixing of fine foreign matter that is a defect in optical applications.

＜＜Solution polymerization＞＞ In the case of solution polymerization, a solution prepared by dissolving a mixture of monomers in an aromatic hydrocarbon solvent such as toluene and ethylbenzene can be used. In the case of polymerization by bulk polymerization, polymerization can be started by irradiation with free radicals generated by heating or ionizing radiation as usual.

As the initiator used in the polymerization reaction, any initiator used in free radical polymerization can be used, for example, azo compounds such as azobisisobutyronitrile; benzyl peroxide, laurel peroxide, hexyl peroxide, etc. Organic peroxides such as tert-butylperoxy-2-ethyl ester.

In particular, when the polymerization is carried out at a high temperature of 90°C or higher, since it is generally a solution polymerization, it is preferably a peroxide or azobis that has a 10-hour half-life temperature of 80°C or higher and is soluble in the organic solvent used. Starter etc. Specific examples include 1,1-bis(tertiary butylperoxy)-3,3,5-trimethylcyclohexane, cyclohexane peroxide, 2,5-dimethyl-2,5 -Bis(benzylperoxy)hexane, 1,1-azobis(1-cyclohexanecarbonitrile), 2-(aminocarboxylazo)isobutyronitrile, etc. These initiators are preferably used in the range of 0.005 to 5% by mass relative to 100% by mass of the total monomers, for example.

In the polymerization reaction, as the molecular weight regulator to be used as needed, any one generally used in radical polymerization can be used. Examples of particularly preferred ones are butyl mercaptan, octyl mercaptan, dodecyl mercaptan, and thiol. Thiol compounds such as 2-ethylhexyl glycolate. These molecular weight modifiers are added in a concentration range that controls the molecular weight of the acrylic resin within the above-mentioned preferred range.

＜＜Block polymerization＞＞ Bulk polymerization is achieved by continuously supplying monomer components and polymerization initiators to the reaction vessel while continuously extracting part of the polymer that can stay in the reaction vessel for a specific period of time, thereby making it possible to produce copolymers with high productivity. .

The polymerization initiator used when polymerizing the monomer components is not particularly limited. For example, azo compounds such as azobisisobutyronitrile and 1,1-bis(tert-butylperoxy)cyclohexane can be used. , Benzyl peroxide, p-chlorobenzyl peroxide, diisopropyl peroxycarbonate, di-2-ethylhexyl peroxycarbonate, tert-butyl peroxypivalate, Peroxy (2-ethylhexanoic acid) tertiary butyl ester and other peroxides are conventional free radical polymerization initiators. The polymerization initiator may be used alone or in combination of two or more kinds. In addition, the amount used is usually 0.01 to 5% by mass relative to the total amount of the mixture. The heating temperature in thermal polymerization is usually 40~200℃, and the heating time is usually about 30 minutes to 8 hours.

When polymerizing monomer components, a chain transfer agent can be used as needed. The chain transfer agent is not particularly limited. Preferred ones include mercaptans such as n-butyl mercaptan, n-octyl mercaptan, n-dodecyl mercaptan, 2-ethylhexyl thioglycolic acid, etc. Wait. A chain transfer agent may be used only 1 type, and may be used in combination of 2 or more types.

＜＜Suspension polymerization＞＞ In the case of suspension polymerization, ordinary suspension polymerization users can be used, and examples thereof include organic peroxides and azo compounds. As the suspension stabilizer, commonly used conventional ones can be used, and examples thereof include organic colloidal polymer materials, inorganic colloidal polymer materials, inorganic particles, and combinations of these with surfactants.

The aqueous medium used to polymerize the monomer mixture is exemplified by water or a mixed medium of a water-soluble solvent such as water and alcohol (for example, methanol, ethanol). The amount of the aqueous medium used is usually 100 to 1000 parts by mass relative to 100 parts by mass of the monomer mixture in order to stabilize the cross-linked resin particles. In addition, in order to suppress the occurrence of emulsified particles in the water system, water-soluble nitrites, sulfites, hydroquinones, ascorbic acid, water-soluble vitamin B, citric acid, polyphenols, etc. can also be used. Polymerization inhibitor.

Furthermore, other suspension stabilizers can be added as needed. Examples are phosphates such as calcium phosphate, magnesium phosphate, aluminum phosphate, zinc phosphate, calcium pyrophosphate, magnesium pyrophosphate, aluminum pyrophosphate, zinc pyrophosphate, etc. pyrophosphate, calcium carbonate, magnesium carbonate, calcium hydroxide, hydrogen Magnesium oxide, aluminum hydroxide, calcium metasilicate, calcium sulfate, barium sulfate and other water-insoluble inorganic compounds, polyvinyl alcohol dispersion stabilizers, etc.

Moreover, surfactants such as anionic surfactants, cationic surfactants, zwitterionic surfactants, and nonionic surfactants may be used in combination with the above-mentioned suspension stabilizer.

Examples of anionic surfactants include fatty acid oils such as sodium oleate and castor oil base, alkyl sulfates such as sodium lauryl sulfate and ammonium lauryl sulfate, and alkylbenzenes such as sodium dodecylbenzene sulfonate. Sulfonate, alkyl sulfonate, alkyl naphthalene sulfonate, alkane sulfonate, succinate sulfonate, dialkyl sulfosuccinate, alkyl phosphate ester salt, naphthalene sulfonate formaldehyde condensate, poly Oxyethylene alkyl phenyl ether sulfate, polyoxyethylene alkyl sulfate, etc.

Examples of nonionic surfactants include polyoxyethylene alkyl ethers, polyoxyethylene alkyl phenyl ethers, polyoxyethylene fatty acid esters, sorbitan fatty acid esters, polyoxysorbitan fatty acid esters, Polyoxyethylene alkylamine, glycerin fatty acid ester, oxyethylene-oxypropylene block polymer, etc.

Examples of cationic surfactants include alkylamine salts such as laurylamine acetate and stearylamine acetate, and quaternary ammonium salts such as lauryltrimethylammonium chloride.

Examples of zwitterionic surfactants include lauryl dimethylamine oxide, phosphate ester-based or phosphite-based surfactants.

These suspension stabilizers or surfactants can be used singly or in combination of two or more, but the suspension stabilizer is selected or the dosage is adjusted appropriately in consideration of the diameter of the particles obtained and the dispersion stability during polymerization. Generally, the addition amount of the suspension stabilizer is 0.5-15 parts by mass relative to 100 parts by mass of the monomer mixture, and the addition amount of the surfactant is 0.001-10 parts by mass relative to 100 parts by mass of the aqueous medium.

The monomer mixture is added to the aqueous medium prepared in this way to perform polymerization.

An example of the dispersion method of the monomer mixture is to directly add the monomer mixture to the aqueous medium, and use the stirring force of the propeller blades to disperse the monomer droplets in the aqueous medium, and use the high shear formed by the rotor and the stator. Dispersion methods such as a homogeneous mixer or an ultrasonic disperser such as a force dispersing machine. Secondly, the aqueous suspension of the monomer mixture dispersed in spherical droplets starts to polymerize by heating. In the polymerization reaction, it is preferable to stir the aqueous suspension, and the stirring may be carried out slowly, for example, to prevent the floating of spherical drops or the sedimentation of the particles after polymerization.

The polymerization temperature is preferably about 30 to 100°C, more preferably about 40 to 80°C. The time for maintaining the polymerization temperature is preferably about 0.1 to 20 hours.

After the polymerization, the water-containing cake is made and separated by methods such as suction filtration of particles, centrifugal dehydration, centrifugal separation, and pressure dehydration, and then the obtained water-containing cake is washed and dried to obtain the target particles. Here, the adjustment of the average particle size of the particles can be performed by adjusting the mixing conditions of the monomer mixture and water, the addition amount of the suspension stabilizer or surfactant, etc., and the stirring conditions and dispersion conditions of the aforementioned mixer.

＜Other ingredients＞ The optical film of the present invention may further contain other components within a range that does not impair the effects of the present invention. Examples of other components include residual solvents, ultraviolet absorbers, antioxidants, and the like.

[Method of manufacturing optical film] The method for producing the optical film of the present invention is to produce an optical film containing organic fine particles, at least a polymer composed of alicyclic hydrocarbon monomers having a polar group, or at least a polymer composed of (meth)acrylic monomers The method is characterized by using organic fine particles that have been treated to remove surfactants present around them as the aforementioned organic fine particles. Specifically, the manufacturing method of the optical film of the present invention is preferably manufactured by a solution casting method. That is, it is preferable to have the following steps: (1) a step of performing a treatment to remove a surfactant from organic fine particles, (2) obtaining the organic fine particles that have been subjected to the treatment of removing the surfactant and at least the organic particles having a polar group. The step of forming a polymer of alicyclic hydrocarbon monomer or at least a polymer formed from a (meth)acrylic monomer and a solvent dope, (3) casting the obtained dope on a metal support, etc. Casting the substrate, drying and peeling to obtain a film, and (4) drying the obtained film while stretching.

About the steps of (1) ＜Organic particles treated to remove surfactants＞ In order to produce organic fine particles by emulsion polymerization, a surfactant must be used in their production, and there will be a surfactant around the organic fine particles produced by emulsion polymerization. Specifically, the surfactant adheres to the surface of the organic fine particles. An example of the treatment for removing the surfactant is a method by washing and heating.

(Wash) As a cleaning method to remove surfactants, the powder of organic fine particles obtained by emulsion polymerization described below is dispersed in a cleaning solvent, or the emulsion obtained by emulsion polymerization is diluted with a cleaning solvent, filtered and After concentration, further repeat dilution, filtration and concentration to remove the surfactant. In the aforementioned cleaning method, since the organic fine particles are produced by emulsion polymerization, the emulsion state after the polymerization is repeatedly diluted, filtered, concentrated and cleaned without powdering the emulsion, so the procedures and costs can be reduced. The aspect is better.

(Washing solvent) As the aforementioned washing solvent, water or alcohol is exemplified, but alcohol is preferable in that the washing effect of washing with alcohol is higher than that of water. This is because the surfactant is attached to the surface of the organic particles through the hydrophobic group, and water only acts on the hydrophilic group on the opposite side of the surfactant, so the ability to remove the surfactant attached to the surface of the organic particles is small. On the other hand, since alcohol can also act on the part of the hydrophobic base attached to the organic microparticles, it has a greater ability to remove surfactants.

When the solvent of the cleaned slurry or wet cake containing organic particles is water, it is preferably spray-dried or freeze-dried to make the organic particles into a water-removed organic particle, and use it to make a dispersion. This dispersion liquid is added to the dope when producing the optical film. This is because the main solvent of the dope used when manufacturing the optical film is dichloromethane, so if water is brought into the dope, it will be phase separated and incompatible, which is not good.

In addition, the solvent used for the aforementioned dilution after concentration is preferably changed from water to alcohol. In this way, the solvent of the slurry or wet cake can be replaced with alcohol from water. Since alcohol is compatible with dichloromethane, the slurry or wet cake is dispersed in a mixed solvent of dichloromethane and alcohol. Even if it is not powdered by spray drying or freeze drying, it can still be made and can be added to the production of optical films. At this time, a dispersion of fine particles in the dope. Furthermore, the solvent of the aforementioned slurry may be changed from alcohol to dichloromethane. By changing to dichloromethane, it is better to introduce into the concentrated liquid of the main body of dichloromethane easier. When the slurry is a dichloromethane solvent, since the alcohol content of the dope can be reduced, the drying is accelerated and the surface quality of the film is improved.

The addition amount of water, alcohol, and methylene chloride as the aforementioned washing solvent is in the range of 5-100 parts by mass relative to 1 part by mass of the fine particles.

(filter) As the aforementioned filtration method, it can be performed by a usual method (dead end filtration) using a membrane filter. Moreover, in order to increase the filtration speed, suction filtration may be performed, or centrifugal force may be used for filtration. In addition, in the present invention, compared to the aforementioned closed-end filtration, cross-flow filtration is adopted, which makes it difficult to form cakes, and is better in terms of increasing the filtration speed.

In addition, the aforementioned dilution, filtration, and concentration remove the solvent containing the surfactant while circulating, add only the concentrated amount of solvent to reduce the surfactant concentration, repeat these operations, and finally concentrate to obtain the surfactant concentration. Reduced paste containing organic particles.

In addition, the organic particles and the solvent can be separated by centrifugal sedimentation and separation, and the solvent decantation can be repeated to clean the organic particles.

In the case where the particle size of the organic particles is small and the filtration efficiency is poor, it is better to add salt and to agglomerate the organic particles to a certain extent by salting out and then filter, in order to improve the filtration efficiency. In addition, a solvent whose SP value deviates from the dispersibility of the organic fine particles may be added to aggregate and filter the organic fine particles. As the solvent for the aforementioned salt or SP value deviation, conventional ones such as water-soluble electrolytes or organic solvents can be used, but based on the productivity of filtration, it is preferable to use magnesium salts such as magnesium chloride or magnesium sulfate, or calcium acetate or chloride. Calcium salts such as calcium. The addition amount of the aforementioned salt or the solvent from which the SP value deviates is preferably 1 to 10 parts by weight relative to 1 part by weight of the organic fine particles.

(Device) Examples of devices that can be used in the step (1) are NGK Philtech Co., Ltd. Membrane Process System Standard (M-1) tester, Mitsubishi Dynafilter (rotary ceramic filter) manufactured by Mitsubishi Chemical Machinery Co., Ltd., and the like.

(heating) An example of a heating method for removing the surfactant is a method of heating the organic fine particles in an emulsion state, whereby the surfactant can be hydrolyzed. In addition, the organic fine particles can also decompose the surfactant by heating, damp heat, and aging in the state of powder particles. Since the surface active agent adheres to the organic fine particles in a substantially molecular state, if moisture is slightly present, the surface active agent is easily further hydrolyzed, and the decomposition reaction is accelerated by heating. As the aforementioned heating temperature, it depends on the heating time, but it is preferably 1-100 hours at 40-160°C. Or, it can be aged at 60°C for 3 months or 23°C for more than 6 months.

In addition, the aforementioned heating method is preferable in that the surfactant can be hydrolyzed when heating is performed in a state where a small amount of water is added to the organic fine particle dispersion liquid for dope addition. In addition, since the organic fine particle dispersion for adding the dope is added to the dope, the water content in the dispersion is preferably less than 1% by mass. In addition, heating in a concentrated liquid state containing organic fine particles and a trace amount of water can also hydrolyze the surfactant.

The step of preparing the aforementioned organic particle dispersion for dope addition and adding it to the dope. When the organic particles are dispersed in dichloromethane, if water is added after or before the dispersion, the water separates in the upper layer and the interface The active agent is extracted in it, so it can be removed by decantation.

About the steps of (2) In the step (2), a polymer comprising organic microparticles subjected to the aforementioned surfactant removal treatment and at least a polymer composed of an alicyclic hydrocarbon monomer having a polar group or at least a (meth)acrylic monomer is obtained. Concentrate of polymer and solvent formed by the body. The solvent used in the dope contains at least an organic solvent (good solvent) that can dissolve the polymer composed of the aforementioned alicyclic hydrocarbon monomers with polar groups or the polymer composed of (meth)acrylic monomers .

Examples of good solvents include chlorine-based organic solvents such as dichloromethane; non-chlorine-based organic solvents such as methyl acetate, ethyl acetate, acetone, and tetrahydrofuran. Among them, dichloromethane is preferred.

The solvent used in the dope may further include a weak solvent. Examples of weak solvents include linear or branched aliphatic alcohols with 1 to 4 carbon atoms. If the ratio of alcohol in the dope becomes higher, the membrane will easily gel, and it will be easier to peel from the cast substrate such as the metal support. Examples of linear or branched aliphatic alcohols having 1 to 4 carbon atoms include methanol, ethanol, n-propanol, isopropanol, n-butanol, sec-butanol, and t-butanol. Among them, in terms of the stability of the concentrated liquid, the relatively low boiling point, and the good drying properties, ethanol is preferred.

The dope can be prepared by directly adding the polymer made from the aforementioned alicyclic hydrocarbon monomers with polar groups or the polymer made from (meth)acrylic monomers to the aforementioned solvents, and then performing the aforementioned removal Surfactant-treated organic microparticles (also called "organic microparticles after removal treatment") are mixed and prepared; it can also be pre-prepared in the aforementioned solvent to dissolve the polymerization of alicyclic hydrocarbon monomers with polar groups. A resin solution of a polymer or a polymer made of a (meth)acrylic monomer, and a fine particle dispersion liquid in which the organic fine particles after the removal treatment are dispersed in the solvent, and these are mixed to prepare.

The method of adding the organic fine particles to the solvent after the aforementioned removal treatment is not particularly limited, and the organic fine particles may be added to the solvent individually, or may be added to the solvent as an aggregate of organic fine particles. The assemblage system of organic particles is formed by a plurality of organic particles whose interconnection (fusion) is inhibited. Therefore, if an aggregate of organic fine particles is dispersed in a polymer made of alicyclic hydrocarbon monomers having a polar group or a polymer made of (meth)acrylic monomers or a solvent with excellent handling properties, Since it can be easily distinguished into organic fine particles, the dispersibility of organic fine particles can be improved. The aggregate of organic fine particles can be obtained by, for example, spray-drying a slurry containing organic fine particles and inorganic powder.

About the steps of (3) The step (3) is to cast the obtained dope on a casting substrate such as a metal support. The casting of the concentrated liquid can be carried out by spraying from the casting mold nozzle.

Secondly, the solvent in the dope cast on the casting base material such as the metal support is evaporated and dried. The dried dope is peeled from the casting substrate such as the metal support to obtain a film. The amount of residual solvent in the dope when peeling from a cast substrate such as a metal support (the amount of residual solvent during peeling) is preferably 10 to 150 mass in terms of the ease of reducing the retardation Ro or Rt of the resulting optical film %, more preferably 20-40% by mass. If the amount of residual solvent during peeling is 10% by mass or more, it will be a polymer composed of alicyclic hydrocarbon monomers with polar groups or a polymer composed of (meth)acrylic monomers during drying or stretching. It is easy to flow and easy to have no alignment, so it is easy to reduce Ro or Rt of the obtained optical film. If the amount of residual solvent during peeling is 150% by mass or less, the force required for peeling the dope will not easily become too large, so it is easy to suppress the breakage of the dope.

The amount of residual solvent in the dope is defined by the following formula. The following is also the same. The amount of residual solvent in the dope (mass%) = (the mass before the dope heat treatment-the mass after the dope heat treatment) / the mass after the dope heat treatment × 100 In addition, the heat treatment at the time of measuring the amount of residual solvent refers to a heat treatment at 120°C for 60 minutes.

About the steps of (4) In the step (4), the obtained film is stretched while drying. The extension can be carried out as long as it is suitable for the required optical properties, preferably in at least one direction, and can also extend in two directions orthogonal to each other (for example, the width direction of the film (TD direction) and the direction orthogonal to it Biaxial extension in the conveying direction (MD direction)).

When the film is stretched biaxially, not only can the phase difference be easily adjusted to a specific range, but the stretching tension applied to the periphery of the organic fine particles can also be made isotropic, so that isotropic voids are easily formed uniformly around the organic fine particles. Thereby, since isotropic voids can be formed around the organic fine particles, the adhesive is easily fused to the voids, and the adhesion with the polarizer is easily improved.

The stretching ratio can be set to 1.01 to 3.5 times based on the viewpoint that the optical film functions as a retardation film for VA, for example, and can be set to 1.01 to 1.3 times based on the viewpoint of functioning as a retardation film for IPS. The higher the stretching ratio, the greater the residual stress of the resulting optical film. The stretch magnification is defined as (size in the extension direction of the film after extension)/(size in the extension direction of the film before extension). In addition, when performing biaxial stretching, it is preferable that each of the TD direction and the MD direction be set to the above-mentioned stretching magnification.

In addition, the in-plane slow axis direction (the direction in which the in-plane refractive index becomes the largest) of the optical film is usually the direction in which the stretch magnification is the largest.

The elongation temperature is preferably (Tg) when the glass transition temperature of the polymer composed of alicyclic hydrocarbon monomers with polar groups or the polymer composed of (meth)acrylic monomers is set to Tg. -65)℃~(Tg+60)℃, more preferably (Tg-50)℃~(Tg+50)℃, still more preferably (Tg-30)℃~(Tg+50)℃. If the stretching temperature is (Tg-30)°C or higher, not only will the film easily become flexible for stretching, but the tension applied to the film during stretching will not be too large, so the resulting optical film will not easily leave excessive residual stress , Ro and Rt are not easy to increase too much. If the stretching temperature is (Tg+60)°C or less, the optical film after stretching is likely to remain moderate residual stress, and it is easy to highly suppress the generation of bubbles due to the vaporization of the solvent in the film. Specifically, the stretching temperature is set to 100 to 220°C.

The amount of residual solvent in the film at the start of stretching is preferably 2-50% by mass. If the amount of residual solvent at the beginning of stretching is 2% by mass or more, the substantial Tg of the film during stretching will be lower due to the plasticizing effect caused by the residual solvent, so Ro and Rt of the optical film will not easily increase. If the amount of residual solvent at the beginning of the extension is 50% by mass or less, the generation of bubbles due to the vaporization of the solvent in the membrane can be highly suppressed.

The stretching of the film in the MD direction can be performed by, for example, generating a difference in the circumferential speed of a plurality of rolls, and using the difference in the circumferential speed between the rolls (roll method). The extension of the film in the TD direction can be performed by, for example, fixing the two ends of the film with clamps or pins, and expanding the interval between the clamps or pins in the traveling direction (tentering method).

[Physical properties of optical film] (Phase difference Ro and Rt) When the optical film of the present invention is used as a retardation film for VA mode, for example, the retardation Ro in the in-plane direction measured in an environment with a measurement wavelength of 550nm and 23°C 55%RH is preferably in the range of 20~120nm. It is more preferably in the range of 30~100nm. The retardation Rt in the thickness direction of the optical film is preferably in the range of 70 to 350 nm, more preferably in the range of 100 to 320 nm.

Ro and Rt of the optical film are respectively defined by the following formulas. Formula (2a): Ro=(nx-ny)×d Formula (2b): Rt=((nx+ny)/2-nz)×d (In the formula, nx represents the refractive index of the in-plane slow axis direction (the direction where the refractive index is the maximum) of the optical film, ny represents the refractive index in the direction orthogonal to the in-plane slow axis of the optical film, nz represents the refractive index in the thickness direction of the optical film, d represents the optical film thickness (nm)).

The so-called in-plane slow axis of the optical film refers to the axis where the refractive index in the plane of the film becomes the largest. The in-plane slow axis of the optical film can be confirmed with an automatic refractometer Axo Scan (Axo Scan Mueller Matrix Polarimeter: manufactured by Axo Matrix).

The measurement of Ro and Rt of the optical film can be carried out by the following method. 1) Adjust the humidity of the optical film at 23°C and 55%RH for 24 hours. The average refractive index of the optical film was measured with an Abbe refractometer, and the thickness d was measured with a commercially available side diameter meter. 2) The retardation Ro and Rt of the optical film after humidity control at a wavelength of 550nm were measured using an automatic refractometer Axo Scan (Axo Scan Mueller Matrix Polarimeter: manufactured by Axo Matrix) at 23°C and 55% RH.

The phase difference Ro and Rt of the optical film can be adjusted mainly by the stretching ratio. In order to increase the retardation Ro and Rt of the optical film, it is preferable to increase the stretching ratio.

(thickness) The thickness of the optical film of the present invention is preferably in the range of, for example, 5 to 100 μm, and more preferably in the range of 5 to 40 μm.

[Polarizer] The polarizing plate of the present invention includes a polarizer and the optical film of the present invention. The optical film of the present invention is preferably arranged on at least one surface of the polarizer (at least the surface opposite to the liquid crystal cell). The polarizer and the optical film are bonded via the adhesive layer.

＜Polarizer＞ The polarizer is an element that only passes the light of the polarization plane in a certain direction, and is a polyvinyl alcohol-based polarizing film. Polyvinyl alcohol-based polarizing films include those that dye polyvinyl alcohol-based films with iodine and those that dye dichroic dyes.

The polyvinyl alcohol-based polarizing film can be a film dyed with iodine or a dichroic dye after uniaxially stretching the polyvinyl alcohol-based film (preferably a film that is treated with a boron compound for durability); After the film is dyed with iodine or dichroic dye, it is a uniaxially stretched film (preferably, a film that is treated with a boron compound for durability). The absorption axis of the polarizer is usually parallel to the maximum extension direction.

For example, ethylene modification with ethylene unit content of 1-4 mol%, polymerization degree of 2000-4000, and saponification degree of 99.0-99.99 mol% described in Japanese Unexamined Patent Publication No. 2003-248123 and Japanese Unexamined Patent Publication No. 2003-342322 Polyvinyl alcohol.

The thickness of the polarizer is preferably 5 to 30 μm, and it is more preferably in the range of 5 to 20 μm in order to reduce the thickness of the polarizing plate or the like.

＜Other optical films＞ When the optical film of the present invention is only arranged on one side of the polarizer, other optical films are arranged on the other side of the polarizer. Examples of other optical films include commercially available cellulose ester films (e.g., KONICA MINOLTA TAC KC8UX, KC5UX, KC4UX, KC8UCR3, KC4SR, KC4BR, KC4CR, KC4DR, KC4FR, KC4KR, KC8UY, KC6UY, KCKUE, 8CY, KC4 HA, KC2UA, KC4UA, KC6UAKC, 2UAH, KC4UAH, KC6UAH, the above are KONICA MINOLTA (share) system, FUJITAC T40UZ, FUJITAC T60UZ, FUJITAC T80UZ, FUJITAC TD80UL, FUJITAC TD80UL, FUJITA R40UL, FUJITA R02 Film (stock) system) and so on.

The thickness of other protective films is not particularly limited, but is preferably 10 to 100 μm, more preferably 10 to 60 μm, and particularly preferably 20 to 60 μm.

＜Manufacturing method of polarizing plate＞ The polarizing plate of the present invention can be obtained by bonding a polarizer and the optical film intermediary adhesive of the present invention. The adhesive is a fully saponified polyvinyl alcohol aqueous solution (water paste) or an active energy ray curable adhesive.

Among them, since it is easy to obtain a polarizing plate having high film strength and excellent flatness, the optical film of the present invention and the polarizer are preferably bonded by an active energy ray curable adhesive.

The active energy ray curable adhesive can be a photo-radical polymerization type composition using photo-radical polymerization, a photo-cation polymerization type composition using photo-cation polymerization, and a mixed type composition using photo-radical polymerization and photo-cation polymerization. Either.

As the photoradical polymerizable composition, there are known radical polymerizable compounds containing polar groups such as hydroxyl or carboxyl groups in a specific ratio described in JP 2008-009329 A, and radical polymerizable compounds that do not contain polar groups. The composition of the compound. In particular, the radically polymerizable compound is preferably a compound having a radically polymerizable ethylenic unsaturated bond. Preferred examples of the compound having a radically polymerizable ethylenic unsaturated bond include a compound having a (meth)acryloyl group. Examples of the compound having a (meth)acryloyl group include N-substituted (meth)acrylamide-based compounds, (meth)acrylate-based compounds, and the like. (Meth)acrylamide means acrylamide or methacrylamide.

As the photocationic polymerizable composition, for example, as disclosed in Japanese Patent Application Laid-Open No. 2011-028234, it contains (α) a cationic polymerizable compound, (β) a photocationic polymerization initiator, and (γ) at a wavelength longer than 380 nm. A light sensitizer that exhibits great absorption of light, and a composition of each component of the (δ) naphthalene-based light sensitizing auxiliary agent.

The manufacturing method of a polarizing plate using an active energy ray curable adhesive includes the following steps (i) a step of applying an active energy ray curable adhesive to at least one of the adhesive surface of the polarizer and the optical film, (ii ) The step of bonding the polarizer and the optical film through the obtained adhesive layer, (iii) the state of bonding the polarizer and the optical film through the adhesive layer, irradiating active energy rays to harden the adhesive layer to obtain The step of polarizing plate, and (iv) the step of punching (cutting) the obtained polarizing plate into a specific shape. Before the step (i), the step of (iv) the easy bonding treatment (corona treatment or plasma treatment, etc.) on the surface of the polarizer of the optical film can also be implemented as needed.

In the step (i), the active energy ray curable adhesive is preferably applied so that the thickness of the adhesive layer after curing becomes, for example, 0.01 to 10 μm, preferably 0.5 to 5 μm.

In the step (iii), visible rays, ultraviolet rays, X-rays and electron beams can be used as the active energy rays irradiated. In view of easy handling and sufficient curing speed, it is generally preferable to use ultraviolet rays. The irradiation conditions of ultraviolet rays are sufficient as long as the conditions can harden the adhesive. For example, the irradiation amount of ultraviolet rays is measured by the cumulative light amount, preferably in the range of 50~1500 mJ/cm ² , and more preferably in the range of 100~500 mJ/cm ² .

[Liquid crystal display device] The liquid crystal display device of the present invention preferably includes a liquid crystal cell, a first polarizing plate arranged on one side of the liquid crystal cell, and a second polarizing plate arranged on the other side of the liquid crystal cell. Preferably, one or both of the first polarizing plate and the second polarizing plate are the aforementioned polarizing plates.

FIG. 1 is a schematic diagram showing an example of the basic structure of a liquid crystal display device. As shown in FIG. 1, the liquid crystal display device 10 of the present invention includes a liquid crystal cell 30, a first polarizing plate 50 arranged on one side of the liquid crystal cell 30, a second polarizing plate 70 arranged on the other side of the liquid crystal cell 30, and a second polarizing plate 70 arranged on the other side of the liquid crystal cell 30. The polarizing plate 70 is arranged on the backlight 90 on the opposite side of the liquid crystal cell 30.

The display mode of the liquid crystal cell 30 can be, for example, STN (Super Twisted Nematic), TN (Twisted Nematic), OCB (Optical Compensation Bend), HAN (Hybrid Alignment Nematic), VA (Vertical Alignment), MVA (Multiple Field vertical alignment), PVA (patterned vertical alignment), IPS (in-plane switching), etc. Among them, VA (MVA, PVA) mode and IPS mode are preferred.

The first polarizing plate 50 includes a first polarizer 51 arranged on one surface of the liquid crystal cell 30 (the surface on the viewing side), and the protection of the surface (the surface on the viewing side) of the first polarizer 51 opposite to the liquid crystal cell 30 The film 53 (F1) and the protective film 55 (F2) disposed on the surface of the first polarizer 51 on the side of the liquid crystal cell 30 (F2).

The second polarizing plate 70 includes a second polarizer 71 arranged on the other side of the liquid crystal cell 30 (the surface on the side of the backlight 90), and a protective film 73 (F3) arranged on the surface of the second polarizer 71 and the liquid crystal cell 30 side. The protective film 75 (F4) is arranged on the surface of the second polarizer 71 opposite to the liquid crystal cell 30 (the surface on the backlight 90 side).

The absorption axis of the first polarizer 51 and the absorption axis of the second polarizer 71 are preferably orthogonal (to be a crossed polarizer).

At least one of the protective films 53 (F1), 55 (F2), 73 (F3), and 75 (F4) can be the optical film of the present invention. Among them, the optical film of the present invention is preferably used as the protective film 55 (F2) or 73 (F3). The liquid crystal display device containing the optical film of the present invention as the protective film 55 (F2) or 73 (F3) has good front contrast, and display unevenness is also reduced.

By using the polarizing plate of the present invention, a liquid crystal display device with excellent visibility such as display unevenness and front contrast can be obtained especially even in a large-screen liquid crystal display device with a screen size of 30 or more. [Example]

Hereinafter, the present invention will be specifically explained with examples, but the present invention is not limited thereto. In addition, in the following examples, unless otherwise specified, the operation was performed at room temperature (25°C). Also, as long as there is no special indication, "%" and "parts" mean "mass %" and "parts by mass".

[Production of Optical Film 1] (Example 1) ＜Production of Seed Particles＞ In a polymerizer equipped with a stirrer and a thermometer, 1000 g of deionized water is fed, 50 g of methyl methacrylate and 6 g of tertiary-dodecyl mercaptan are fed into the polymerizer, and the temperature is heated to 70°C while purging with nitrogen while stirring. . The internal temperature was kept at 70°C, and 20 g of deionized water in which 1 g of potassium persulfate was dissolved as a polymerization initiator was added, followed by polymerization for 10 hours. The average particle size of the seed particles in the obtained emulsion was 0.05 μm.

＜Production of organic fine particles 1＞ In a polymerizer equipped with a stirrer and a thermometer, 650 g of deionized water containing 2.4 g of sodium lauryl sulfate as a surfactant is fed into it, and methyl methacrylate as a monomer mixture (in the following table Described as MMA) 66 g, 20 g of styrene, 64 g of ethylene glycol dimethacrylate, and 1 g of azobisisobutyronitrile as a polymerization initiator. Next, the mixed liquid was stirred with a T.K homomixer (manufactured by Special Chemical Industry Co., Ltd.) to obtain a dispersion liquid. 60 g of the emulsion containing the above-mentioned seed particles was added to the obtained dispersion, and the mixture was stirred at 30°C for 1 hour to allow the seed particles to absorb the monomer mixture. Secondly, the absorbed monomer mixture is heated at 50°C for 5 hours under nitrogen flow and polymerized, and then cooled to room temperature (about 25°C) to obtain polymer particles (organic particles) and sodium lauryl sulfate attached to the surface. The emulsion of the complex. The solid content concentration of the obtained organic microparticles was 20%.

<Production of the aggregate of organic fine particles 1> The above-mentioned emulsion was spray-dried under the following conditions with a spray dryer (model: Atomizer Take-up method, model: TRS-3WK) manufactured by Sakamoto Giken Co., Ltd. as a spray dryer to obtain A collection of organic particles. Supply speed: 25mL/min Atomizer rotation number: 11000rpm Air volume: 2m ³ /min The slurry inlet temperature of the spray dryer: 100℃ The polymer particle aggregate outlet temperature: 50℃

＜Removal treatment of organic microparticles 1 surfactant 1＞ Put 95 parts by mass of deionized water into the organic fine particle dispersion tank, and then put in 5 parts by mass of the above organic fine particles 1, stir and mix with a disperser for 30 minutes, and then disperse with Manton-Gaulin. The dispersion was filtered with an Omnipore membrane filter (maximum pore size 0.2 μm) to obtain a wet cake containing 5 parts by mass of organic particles and 5 parts by mass of deionized water. The filtration time is 60 minutes. The wet cake was put into the dispersion tank again, 90 parts by mass of deionized water was put into it, and stirred and mixed with a disperser for 30 minutes to obtain a dispersion. The dispersion was filtered again with an Omnipore membrane filter (maximum pore size 0.2 μm) to obtain a wet cake containing 5 parts by mass of organic particles and 5 parts by mass of deionized water. The wet cake was vacuum dried at 50°C to obtain organic microparticles from which the surfactant was removed.

For the organic fine particles after the removal treatment, the refractive index and average particle size were measured by the following method. In addition, the solubility of the active agent used in the production of organic microparticles was also measured by the following method.

＜Measurement of refractive index＞ The obtained organic microparticles are press-molded, and the average refractive index of the molded body is measured with a laser refractometer, and this value is taken as the refractive index of the organic microparticles. In this embodiment, the term “refractive index” refers to the refractive index of light with a wavelength of 550 nm at 23°C.

＜Measurement of average particle size＞ For the obtained organic fine particles, the average particle size was determined by the dynamic light scattering method using MICROTRAC UPA150 (manufactured by Nikkiso Co., Ltd.).

＜Measurement of solubility＞ Regarding the solubility of the surfactant used in the production of the aforementioned organic microparticles to ethanol, dichloromethane, and water, it was dissolved in various solvents at 23° C. and judged visually. Specifically, for example, for 100g of water at 23°C, a small amount of surfactant is added successively, 10.0g is dissolved, and insoluble matter is observed in 10.1g, and the solubility in water is 10/(100+10)=9.1 mass %. In addition, the measurement results of solubility are shown in the following table.

<Synthesis of polymers made from alicyclic hydrocarbon monomers with polar groups> 100 parts by mass of the following compounds, which are alicyclic hydrocarbon monomers with polar groups (norbornene-based monomers), are adjusted in molecular weight 3.6 parts by mass of 1-hexene and 200 parts by mass of toluene of the agent were fed into a reaction vessel replaced with nitrogen and heated at 80°C. To this was added triethyl aluminum ((C ₂ H ₅ ) ₃ Al) 1.5 mol/L of toluene solution 0.17 parts by mass as a polymerization catalyst, containing tungsten hexachloride modified with tertiary butanol and methanol ( WCl ₆ ) and tertiary butanol: methanol: tungsten = 0.35: 0.3:1 (molar ratio) of WCl ₆ solution (concentration 0.05 mol/l) 1.0 parts by mass, heated and stirred at 80° C. for 3 hours to open the ring Polymerize to obtain a polymer solution. The polymerization conversion rate in this polymerization reaction was 98%.

4000 parts by mass of the obtained polymer solution was put into an autoclave, and _{0.48 parts by mass of RuHCl(CO)[P(C 6} H ₅ ) ₃ ] ₃ was added to the polymer solution. The hydrogen pressure was 10MPa and the reaction temperature was 160°C. The conditions were heated and stirred for 3 hours to carry out the hydrogenation reaction. After the resultant reaction solution is cooled, the hydrogen pressure is released, the reaction solution is poured into a large amount of methanol, and the coagulum is separated and recovered. The recovered coagulum was dried to obtain a cycloolefin-based polymer (in the following table, it is described as COP). After measuring the weight average molecular weight of the resulting polymer composed of alicyclic hydrocarbon monomers, the weight average molecular weight was 140,000. In addition, the refractive index of the obtained polymer composed of alicyclic hydrocarbon monomer was measured by the same method as the aforementioned method for measuring the refractive index of organic fine particles.

＜Preparation of organic microparticle additive solution＞ The following materials were stirred and mixed with a disperser for 50 minutes, and then dispersed by Manton-Gaulin. This was filtered with Finemate NM5P-2400 manufactured by Nippon Seiki Co., Ltd. to prepare an organic fine particle additive liquid with an organic fine particle content of 3.0% by mass. 1:3 parts by mass of organic particles after the aforementioned removal treatment Dichloromethane: 97 parts by mass

<Preparation of Dope Containing Organic Microparticles> Dichloromethane and ethanol are put into the pressure dissolution tank in advance. Next, the obtained polymer containing alicyclic hydrocarbon monomers was poured into the pressurized dissolution tank while stirring, and 3% by mass of the organic fine particle additive liquid was added to prepare a dope with the following composition. Use Azumi filter paper No.244 (filtration accuracy 7μm) made by Azumi filter paper (stock), and filter it with a filtration flow of 300L/m ² ･h and a filter pressure of 1.0×10 ⁶ Pa. (Dense liquid composition) The aforementioned polymer composed of alicyclic hydrocarbon monomers: 98.5 parts by mass dichloromethane: 250.0 parts by mass ethanol: 20.0 parts by mass 3% by mass organic fine particles additive liquid: 50.0 parts by mass (amount of fine particles: 1.5 Parts by mass) The solid in the above-mentioned dope has a composition containing alicyclic hydrocarbon monomer polymer (98.5% by mass) and organic microparticles (1.5% by mass).

＜Film formation＞ From the pressurized dissolution tank, the above-prepared dope is sent to the pressurizing die nozzle by a gear pump, and cast on the casting base material (stainless steel ring support body). After evaporating the solvent until the amount of residual solvent in the casting dope becomes 40% by mass, the resulting film is peeled from the casting substrate (stainless steel ring support) with a peeling tension of 130 N/m. The peeled film is transported to the tenter stretching device while drying, and is transported in the tenter in the width direction at a stretching ratio of 50% (1.5 times). At this time, adjust the drying conditions from peeling to the tenter so that the amount of residual solvent during stretching becomes 11% by mass. In addition, the temperature of the tenter stretching device was set to 160°C, and the stretching speed was set to 200%/min. Secondly, the drying is finished while being transported by many rollers in the drying device. The drying temperature is 130°C, and the conveying tension is 100N/m. Subsequently, both ends of the obtained optical film were cut, and embossing was performed to produce an optical film 1 with a dry film thickness of 40 μm.

[Production of Optical Film 2] (Example 2) Using the organic fine particles 1 used in the production of the aforementioned optical film 1, an optical film 2 was produced in the same manner except that the surfactant removal treatment was performed by the following method.

＜Removal treatment of the surface active agent of organic fine particles 1 2＞ 95 parts by mass of ethanol was put into the organic fine particle dispersion tank, and then 5 parts by mass of the aforementioned organic fine particles 1 were put in, and after stirring and mixing with a disperser for 30 minutes, the dispersion was carried out by Manton-Gaulin. The dispersion was filtered with an Omnipore membrane filter (maximum pore size 0.2 μm) to obtain a wet cake containing 5 parts by mass of organic fine particles 1 and 5 parts by mass of ethanol. The filtration time is 70 minutes. The wet cake was put into the dispersion tank again, 90 parts by mass of ethanol was put into it, and stirred and mixed with a disperser for 30 minutes to obtain a dispersion. The dispersion was filtered again with an Omnipore membrane filter (maximum pore size 0.2 μm) to obtain a wet cake containing 5 parts by mass of organic fine particles 1 and 5 parts by mass of ethanol. The wet cake was vacuum dried at 50°C to obtain organic microparticles 1 from which the surfactant was removed.

[Production of Optical Film 3] (Example 3) Using the organic fine particles 1 used in the production of the aforementioned optical film 1, an optical film 3 was produced in the same manner except that the surfactant removal treatment was performed by the following method.

＜Removal treatment 3 of the surfactant of organic fine particles 1＞ Put 20 parts by mass of deionized water into the organic fine particle dispersion tank, and then put in 5 parts by mass of the aforementioned organic fine particles 1, stir and mix with a disperser for 30 minutes, and then disperse with Manton-Gaulin. 75 parts by mass of a 10% solution of NaCl was added to the dispersion, and stirred and mixed to obtain a dispersion of agglomerated organic fine particles. The dispersion was filtered with an Omnipore membrane filter (maximum pore size 0.2 μm) to obtain a wet cake containing 5 parts by mass of organic fine particles 1 and 5 parts by mass of deionized water. The filtration time is 10 minutes. The wet cake was put into the dispersion tank again, 90 parts by mass of deionized water was put into it, and stirred and mixed with a disperser for 30 minutes to obtain a dispersion. The dispersion was filtered again with an Omnipore membrane filter (maximum pore size 0.2 μm) to obtain a wet cake containing 5 parts by mass of organic fine particles 1 and 5 parts by mass of deionized water. The wet cake was vacuum dried at 50° C. to obtain organic particles 1 from which the active agent was removed.

[Production of Optical Film 4] (Example 4) Using the organic fine particles 1 used in the production of the aforementioned optical film 1, an optical film 4 was produced in the same manner except that the surfactant removal treatment was performed by the following method.

<Removal treatment 4 of the surfactant of organic particles 1> Ceramic membrane filtration system (standard (M-1) testing machine, manufactured by NGK Philtech) on a filter with a UF membrane with a pore size of 10 nm (division molecular weight of 50,000) )) Put 25 parts by mass of the emulsion containing the complex of organic fine particles 1 and sodium laurate obtained from the above-mentioned organic fine particles 1 into the liquid feeding tank, and put 75 parts by mass of deionized water into the organic fine particle dispersion liquid. The circulation pump is operated, the flow rate of the dispersion liquid in the filter is set to 3 m/sec, and the dispersion liquid is circulated while applying a pressure of 0.1 MPa to the dispersion liquid, and the dispersion liquid is concentrated to 25 parts by mass. After concentration, 75 parts by mass of deionized water was added to the liquid feeding tank, and the dispersion was concentrated again to 25 parts by mass. The dispersion was spray-dried under the following conditions using a spray dryer (model: Atomizer Take-up method, model: TRS-3WK) manufactured by Sakamoto Giken Co., Ltd. (type: Atomizer Take-up method, model: TRS-3WK) as a spray dryer under the following conditions to make organic The particles are dry. Supply speed: 10mL/min Atomizer rotation number: 11000rpm Air volume: 2m ³ /min The slurry inlet temperature of the spray dryer: 100℃ The polymer particle aggregate outlet temperature: 50℃

[Production of Optical Film 5] (Example 5) Using the organic fine particles 1 used in the production of the aforementioned optical film 1, an optical film 5 was produced in the same manner except that the surfactant removal treatment was performed by the following method.

<Removal treatment of surfactant 5 of organic fine particles 1> Ceramic membrane filtration system (standard (M-1) testing machine, manufactured by NGK Philtech) on a filter with a UF membrane with a pore size of 10 nm (division molecular weight of 50,000) )) In the liquid feeding tank, put 20 parts by mass of the emulsion containing the complex of organic fine particles 1 and sodium laurate prepared by the above-mentioned organic fine particles 1, and put 80 parts by mass of ethanol into the organic fine particle dispersion liquid. The circulation pump is operated, the flow rate of the dispersion liquid in the filter is set to 3 m/sec, the dispersion liquid is circulated while applying a pressure of 0.2 MPa to the dispersion liquid, and the dispersion liquid is concentrated to 20 parts by mass. After concentration, 80 parts by mass of ethanol was added to the liquid feed tank, and the dispersion was concentrated again to 20 parts by mass. The dispersion was spray-dried using a spray dryer (model: Atomizer Take-up method, model: TRS-3WK) manufactured by Sakamoto Techken Co., Ltd. as a spray dryer under the following conditions to dry organic fine particles. Supply speed: 10mL/min Atomizer rotation number: 11000rpm Air volume: 2m ³ /min The slurry inlet temperature of the spray dryer: 100℃ The polymer particle aggregate outlet temperature: 50℃

[Production of Optical Film 6] (Example 6) The optical film 6 was produced in the same manner except that the emulsion containing the composite of the organic fine particles 1 and sodium laurate obtained by the preparation of the optical film 1 was subjected to the surfactant removal treatment and the preparation of the organic fine particle additive liquid by the following method.

＜Removal treatment of surface active agent of organic fine particles 1 6＞ A ceramic membrane filtration system (standard (M-1) testing machine, manufactured by NGK Philtech (stock)) with a ceramic membrane filtration system (standard (M-1) testing machine, manufactured by NGK Philtech (stock)) with a UF membrane with a pore size of 10 nm (partial molecular weight 50,000) is put into the liquid feeding tank of the above organic particles 1 20 parts by mass of an emulsion containing a complex of organic microparticles 1 and sodium laurate was prepared, and 80 parts by mass of ethanol was added to form a dispersion of organic microparticles. The circulation pump is operated, the flow rate of the dispersion liquid in the filter is set to 3 m/sec, the dispersion liquid is circulated while applying a pressure of 0.2 MPa to the dispersion liquid, and the dispersion liquid is concentrated to 20 parts by mass. After concentration, 80 parts by mass of ethanol was added to the liquid feed tank, and the dispersion was concentrated again to 20 parts by mass.

＜Preparation of organic microparticle additive solution＞ The following materials were stirred and mixed with a disperser for 50 minutes, and then dispersed by Manton-Gaulin. This was filtered with Finemate NM5P-2400 manufactured by Nippon Seiki Co., Ltd. to prepare an organic fine particle additive liquid with an organic fine particle content of 3.0% by mass. The aforementioned concentrated organic fine particle dispersion: 15 parts by mass Dichloromethane: 85 parts by mass

[Production of Optical Film 7] (Example 7) Using the organic fine particles 1 used in the production of the aforementioned optical film 1, the optical film 7 was produced in the same manner except that the surfactant removal treatment and the preparation of the organic fine particle additive liquid were performed by the following method.

＜Removal treatment of organic fine particles 1 surfactant 7＞ A ceramic membrane filtration system (standard (M-1) testing machine, manufactured by NGK Philtech (stock)) with a ceramic membrane filtration system (standard (M-1) testing machine, manufactured by NGK Philtech (stock)) with a UF membrane with a pore size of 10 nm (partial molecular weight 50,000) is put into the liquid feeding tank of the above organic particles 1 20 parts by mass of an emulsion containing a complex of organic microparticles 1 and sodium laurate was prepared, and 80 parts by mass of ethanol was added to form a dispersion of organic microparticles. The circulation pump is operated, the flow rate of the dispersion liquid in the filter is set to 3 m/sec, the dispersion liquid is circulated while applying a pressure of 0.2 MPa to the dispersion liquid, and the dispersion liquid is concentrated to 20 parts by mass. After concentration, 80 parts by mass of ethanol was added to the liquid feed tank, and the dispersion was concentrated again to 20 parts by mass. After concentration, 80 parts by mass of dichloromethane were added to the liquid feed tank next, and the dispersion was concentrated to 20 parts by mass, which was repeated once more.

＜Preparation of organic microparticle additive solution＞ The following materials were stirred and mixed with a disperser for 50 minutes, and then dispersed by Manton-Gaulin. This was filtered with Finemate NM5P-2400 manufactured by Nippon Seiki Co., Ltd. to prepare an organic fine particle additive liquid with an organic fine particle content of 3.0% by mass. The aforementioned concentrated organic fine particle dispersion: 15 parts by mass Dichloromethane: 85 parts by mass

[Production of Optical Film 8] (Example 8) Using the organic fine particles 1 used in the production of the aforementioned optical film 1, an optical film 8 was produced in the same manner except that the surfactant removal treatment was performed by the following method.

＜Removal treatment of organic fine particles 1 surfactant 8＞ The aforementioned organic fine particles 1 are heated at 120°C for 24 hours to decompose and remove the surfactant.

[Production of Optical Film 9] (Example 9) Using the organic fine particles 1 used in the production of the aforementioned optical film 1, an optical film 9 was produced in the same manner except that the surfactant removal treatment was performed by the following method.

＜Removal treatment of organic fine particles 1 surfactant 9＞ The aforementioned organic fine particles 1 were aged at 60°C for 3 months, and the surfactant was decomposed and removed.

[Production of Optical Film 10] (Example 10) Using the organic fine particles 1 used in the production of the optical film 1 described above, the optical film 10 was produced in the same manner except that the surfactant removal treatment was performed by the following method.

＜Removal treatment of surfactant of organic fine particles 1 10＞ The aforementioned organic fine particles 1 are subjected to wet heat treatment at 80° C. and 90% RH for 24 hours to decompose and remove the surfactant.

[Production of Optical Film 11] (Example 11) The preparation and modification of the organic fine particle additive liquid of the aforementioned optical film 1 is as follows. In addition, an optical film 11 was produced in the same manner as the optical film 1 described above.

＜Preparation of organic microparticle additive solution＞ In the organic fine particle mixing tank, the following materials were stirred and mixed with a disperser for 50 minutes. 1:3 parts by mass of organic particles before surfactant removal treatment Dichloromethane: 96 parts by mass Deionized water: 1 part by mass After mixing, let it stand for 24 hours to separate the dichloromethane and the water phase, the upper layer forms the water phase, and the lower layer forms the dichloromethane phase. Sodium lauryl sulfate as a surfactant dissolves in water, and because it is insoluble in dichloromethane, it is extracted into the water phase. When taking out the mixed liquid from the mixed liquid discharge port provided at the bottom of the mixing tank, leave 10 parts by mass and take out the mixed liquid to remove the surfactant contained in the upper aqueous phase. The mixed solution was put into an organic fine particle dispersion tank and dispersed by Manton-Gaulin. This was filtered with Finemate NM5P-2400 manufactured by Nippon Seiki Co., Ltd. to prepare an organic fine particle additive liquid with an organic fine particle content of 3.0% by mass.

[Production of Optical Film 12] (Example 12) In the production of the aforementioned optical film 6, except that the polymer composed of an alicyclic hydrocarbon monomer having a polar group was changed to the following polymer composed of a (meth)acrylic monomer, the optical film 6 was produced in the same manner.膜12。 Film 12. The refractive index of the polymer made of the acrylic monomer is also measured in the same way as the method for measuring the refractive index of the aforementioned organic fine particles. DIANAL BR85 (Mw=280000) (manufactured by Mitsubishi Chemical Co., Ltd.) (the ratio of (meth)acrylic monomers in the molecule of the acrylic resin: 90% by mass or more)

[Production of Optical Film 13] (Comparative Example 1) The optical film 13 was produced in the same manner except that the organic fine particles 1 used in the production of the aforementioned optical film 1 were not subjected to the removal treatment of the surfactant and used as they were.

[Production of Optical Film 14] (Comparative Example 2) In the production of the aforementioned optical film 6, the optical film 14 was produced in the same manner except that the organic fine particles 1 were changed to the following organic fine particles 2.

＜Production of Seed Particles＞ In a polymerizer equipped with a stirrer and a thermometer, 1000 g of deionized water is fed, 50 g of methyl methacrylate and 6 g of tertiary-dodecyl mercaptan are fed into the polymerizer, and the temperature is heated to 70°C while purging with nitrogen while stirring. . The internal temperature was kept at 70°C, and 20 g of deionized water in which 1 g of potassium persulfate was dissolved as a polymerization initiator was added, followed by polymerization for 10 hours. The average particle size of the seed particles in the obtained emulsion was 0.05 μm.

＜Production of organic fine particles 2＞ In a polymerizer equipped with a stirrer and a thermometer, 650g of deionized water with 2.4g of diglycerol monolaurate (manufactured by Riken Vitamin Co., Ltd., POEM DL-100) dissolved as a surfactant is fed into it A mixture of 66 g of methyl methacrylate as a monomer mixture, 20 g of styrene, 64 g of ethylene glycol dimethacrylate, and 1 g of azobisisobutyronitrile as a polymerization initiator. Next, the mixed liquid was stirred with a T.K homomixer (manufactured by Special Chemical Industry Co., Ltd.) to obtain a dispersion liquid. 60 g of the emulsion containing the above-mentioned seed particles was added to the obtained dispersion, and the mixture was stirred at 30°C for 2 hours to allow the seed particles to absorb the monomer mixture. Secondly, the absorbed monomer mixture was heated at 50°C for 6 hours under nitrogen flow and polymerized, and then cooled to room temperature (about 25°C) to obtain polymer particles (organic particles 2) and diglycerin laurel attached to the surface. Emulsion of a complex of acid ester (manufactured by Riken Vitamin Co., Ltd., POEM DL-100). The solid content concentration of the obtained organic fine particles 2 was 20%.

[Production of Optical Film 15] (Comparative Example 3) In the production of the aforementioned optical film 6, except that the organic fine particles 1 are changed to the following organic fine particles 3, the optical film 15 is produced in the same manner.

＜Production of Seed Particles＞ In a polymerizer equipped with a stirrer and a thermometer, 1000 g of deionized water is fed, 50 g of methyl methacrylate and 6 g of tertiary-dodecyl mercaptan are fed into the polymerizer, and the temperature is heated to 70°C while purging with nitrogen while stirring. . The internal temperature was kept at 70°C, and 20 g of deionized water in which 1 g of potassium persulfate was dissolved as a polymerization initiator was added, followed by polymerization for 10 hours. The average particle size of the seed particles in the obtained emulsion was 0.05 μm.

＜Production of organic fine particles 3＞ In a polymerizer equipped with a stirrer and a thermometer, 650 g of deionized water with 2.4 g of fatty acid potassium (Daiichi Industrial Pharmaceutical Co., Ltd., DK Kalisoap GT) dissolved as a surfactant is fed into it as a monomer mixture A mixture of 66 g of methyl methacrylate, 20 g of styrene, 64 g of ethylene glycol dimethacrylate, and 1 g of azobisisobutyronitrile as a polymerization initiator. Next, the mixed liquid was stirred with a T.K homomixer (manufactured by Special Chemical Industry Co., Ltd.) to obtain a dispersion liquid. 60 g of the emulsion containing the above-mentioned seed particles was added to the obtained dispersion, and the mixture was stirred at 30° C. for 30 minutes to make the seed particles absorb the monomer mixture. Secondly, the absorbed monomer mixture was heated at 50°C for 4 hours under a nitrogen stream to polymerize, and then cooled to room temperature (about 25°C) to obtain polymer particles (organic particles 3) and fatty acid potassium ( First Industrial Pharmaceutical (stock), DK Kalisoap GT) complex emulsion. The solid content concentration of the obtained organic fine particles 3 was 20%.

[Production of Optical Film 16] (Comparative Example 4) In the production of the aforementioned optical film 11, the optical film 16 was produced in the same manner except that the organic fine particles 1 were changed to the organic fine particles 4 described below.

＜Production of Seed Particles＞ In a polymerizer equipped with a stirrer and a thermometer, 1000 g of deionized water is fed, 50 g of methyl methacrylate and 6 g of tertiary-dodecyl mercaptan are fed into the polymerizer, and the temperature is heated to 70°C while purging with nitrogen while stirring. . The internal temperature was kept at 70°C, and 20 g of deionized water in which 1 g of potassium persulfate was dissolved as a polymerization initiator was added, followed by polymerization for 10 hours. The average particle size of the seed particles in the obtained emulsion was 0.05 μm.

＜Production of organic particles 4＞ In a polymerizer equipped with a stirrer and a thermometer, 650g of deionized water with 2.4g of quaternary ammonium salt (First Industrial Pharmaceutical Co., Ltd., Catiogen TML) dissolved as a surfactant is fed into it as a monomer A mixture of 66 g of methyl methacrylate, 20 g of styrene, 64 g of ethylene glycol dimethacrylate, and 1 g of azobisisobutyronitrile as a polymerization initiator. Next, the mixed liquid was stirred with a T.K homomixer (manufactured by Special Chemical Industry Co., Ltd.) to obtain a dispersion liquid. 60 g of the emulsion containing the above-mentioned seed particles was added to the obtained dispersion, and the mixture was stirred at 30°C for 1 hour to allow the seed particles to absorb the monomer mixture. Secondly, the absorbed monomer mixture is heated at 50°C for 5 hours under nitrogen flow and polymerized, and then cooled to room temperature (about 25°C) to obtain polymer particles (organic particles 4) and quaternary ammonium attached to the surface. Emulsion of complex of salt (First Industrial Pharmaceutical Co., Ltd., Catiogen TML). The solid content concentration of the obtained organic fine particles 4 was 20%.

<Production of the aggregate of organic particles 4> The above-mentioned emulsion was spray-dried under the following conditions with a spray dryer (model: Atomizer Take-up method, model: TRS-3WK) manufactured by Sakamoto Giken Co., Ltd. as a spray dryer to obtain A collection of organic fine particles 4. Supply speed: 25mL/min Atomizer rotation number: 11000rpm Air volume: 2m ³ /min The slurry inlet temperature of the spray dryer: 100℃ The polymer particle aggregate outlet temperature: 50℃

[Production of Optical Film 17] (Comparative Example 5) In the production of the aforementioned optical film 1, except that the organic fine particles 1 were changed to the following organic fine particles 5, the optical film 17 was produced in the same manner.

＜Production of Seed Particles＞ In a polymerizer equipped with a stirrer and a thermometer, 1000 g of deionized water is fed, 50 g of methyl methacrylate and 6 g of tertiary-dodecyl mercaptan are fed into the polymerizer, and the temperature is heated to 70°C while purging with nitrogen while stirring. . The internal temperature was kept at 70°C, and 20 g of deionized water in which 1 g of potassium persulfate was dissolved as a polymerization initiator was added, followed by polymerization for 10 hours. The average particle size of the seed particles in the obtained emulsion was 0.05 μm.

＜Production of Organic Microparticle 5＞ Into a polymerizer equipped with a stirrer and a thermometer, 650g of deionized water with 2.4g of polyoxyethylene alkyl phenyl ether (Noigen EA-87) as a surfactant dissolved in A mixture of 66 g of methyl methacrylate as a monomer mixture, 20 g of styrene, 64 g of ethylene glycol dimethacrylate, and 1 g of azobisisobutyronitrile as a polymerization initiator was fed. Next, the mixed liquid was stirred with a T.K homomixer (manufactured by Special Chemical Industry Co., Ltd.) to obtain a dispersion liquid. 60 g of the emulsion containing the above-mentioned seed particles was added to the obtained dispersion, and the mixture was stirred at 30°C for 3 hours to allow the seed particles to absorb the monomer mixture. Secondly, the absorbed monomer mixture was heated at 50°C for 7 hours under a nitrogen stream and polymerized, and then cooled to room temperature (about 25°C) to obtain polymer particles (organic particles 5) and polyoxyethylene attached to the surface. Emulsion of the complex of alkyl phenyl ether (Noigen EA-87, Noigen EA-87). The solid content concentration of the obtained organic fine particles 5 was 20%.

<Production of the aggregate of organic fine particles 5> The above-mentioned emulsion was spray-dried under the following conditions with a spray dryer (model: Atomizer Take-up method, model: TRS-3WK) manufactured by Sakamoto Giken Co., Ltd. as a spray dryer to obtain A collection of organic microparticles 5. Supply speed: 25mL/min Atomizer rotation number: 11000rpm Air volume: 2m ³ /min The slurry inlet temperature of the spray dryer: 100℃ The polymer particle aggregate outlet temperature: 50℃

[Production of Optical Film 18] (Comparative Example 6) In the production of the optical film 8, except for the organic fine particles 1 being changed to the organic fine particles 5, the optical film 18 was produced in the same manner.

[Production of Optical Film 19] (Comparative Example 7) In the production of the aforementioned optical film 6, except that the organic fine particles 1 are changed to the following organic fine particles 7, the optical film 19 is produced in the same manner.

＜Production of organic fine particles 7＞ In a polymerizer equipped with a stirrer and a thermometer, 650 g of deionized water with 2.4 g of sodium lauryl sulfate dissolved as a surfactant is fed, and 50 g of styrene and ethylene glycol dimethyl as a monomer mixture are fed into it A mixture of 100 g of acrylate and 1 g of azobisisobutyronitrile as a polymerization initiator. Next, the mixed liquid was stirred with a T.K homomixer (manufactured by Special Chemical Industry Co., Ltd.) to obtain a dispersion liquid. To the obtained dispersion liquid, 60 g of an emulsion containing the seed particles used in the production of the organic fine particles 1 was added, and the mixture was stirred at 30°C for 1 hour to allow the seed particles to absorb the monomer mixture. Secondly, the absorbed monomer mixture was heated at 50°C for 5 hours under a nitrogen stream to polymerize, and then cooled to room temperature (about 25°C) to obtain polymer particles (organic particles 7) and lauryl sulfuric acid attached to the surface. Emulsion of sodium complex. The solid content concentration of the obtained organic fine particles 7 was 20%.

[Production of Optical Film 20] (Comparative Example 8) In the production of the aforementioned optical film 6, the aforementioned polymer composed of an alicyclic hydrocarbon monomer having a polar group was changed to cellulose triacetate (TAC) with a number average molecular weight of Mn70000 and a degree of acetyl substitution of 2.80. , The optical film 20 was produced in the same manner.

[Production of Optical Film 21] (Example 13) In the production of the aforementioned optical film 6, the optical film 21 was produced in the same manner except that the organic fine particles 1 were changed to the following organic fine particles 13.

＜Production of Seed Particles＞ In a polymerizer equipped with a stirrer and a thermometer, 1000 g of deionized water is fed, 50 g of methyl methacrylate and 6 g of tertiary-dodecyl mercaptan are fed into the polymerizer, and the temperature is heated to 70°C while purging with nitrogen while stirring. . The internal temperature was kept at 70°C, and 20 g of deionized water in which 1 g of potassium persulfate was dissolved as a polymerization initiator was added, followed by polymerization for 10 hours. The average particle size of the seed particles in the obtained emulsion was 0.05 μm.

＜Production of organic particles 13＞ In a polymerizer equipped with a stirrer and a thermometer, 650g of deionized water with 2.4g of polyoxyethylene polyoxypropylene glycol (Epan750, manufactured by Daiichi Industrial Pharmaceutical Co., Ltd.) dissolved as a surfactant is fed into it as The monomer mixture is a mixture of 66 g of methyl methacrylate, 20 g of styrene, 64 g of ethylene glycol dimethacrylate, and 1 g of azobisisobutyronitrile as a polymerization initiator. Next, the mixed liquid was stirred with a T.K homomixer (manufactured by Special Chemical Industry Co., Ltd.) to obtain a dispersion liquid. 60 g of the emulsion containing the above-mentioned seed particles was added to the obtained dispersion, and the mixture was stirred at 30°C for 1 hour to allow the seed particles to absorb the monomer mixture. Secondly, the absorbed monomer mixture was heated at 50°C for 5 hours under a nitrogen stream and polymerized, and then cooled to room temperature (about 25°C) to obtain polymer particles (organic particles 13) and polyoxyethylene attached to the surface. Emulsion of polyoxypropylene glycol complex. The solid content concentration of the obtained organic fine particles 13 was 20%.

<Production of the aggregate of organic fine particles 13> The above-mentioned emulsion was spray-dried under the following conditions with a spray dryer (model: Atomizer Take-up method, model: TRS-3WK) manufactured by Sakamoto Giken Co., Ltd. as a spray dryer to obtain A collection of organic particles 13. Supply speed: 25mL/min Atomizer rotation number: 11000rpm Air volume: 2m ³ /min The slurry inlet temperature of the spray dryer: 100℃ The polymer particle aggregate outlet temperature: 50℃

[Production of Optical Film 22] (Example 14) In the production of the aforementioned optical film 6, except that the organic fine particles 1 were changed to the following organic fine particles 14, the optical film 22 was produced in the same manner.

＜Production of Seed Particles＞ In a polymerizer equipped with a stirrer and a thermometer, 1000 g of deionized water is fed, 50 g of methyl methacrylate and 6 g of tertiary-dodecyl mercaptan are fed into the polymerizer, and the temperature is heated to 70°C while purging with nitrogen while stirring. . The internal temperature was kept at 70°C, and 20 g of deionized water in which 1 g of potassium persulfate was dissolved as a polymerization initiator was added, followed by polymerization for 10 hours. The average particle size of the seed particles in the obtained emulsion was 0.05 μm.

＜Production of organic particles 14＞ In a polymerizer equipped with a stirrer and a thermometer, 650 g of deionized water with 2.4 g of sodium lauryl sulfate dissolved as a surfactant is fed, and 56 g of methyl methacrylate and 25 g of styrene as a monomer mixture are fed into it And a mixed solution of 69 g of ethylene glycol dimethacrylate and 1 g of azobisisobutyronitrile as a polymerization initiator. Next, the mixed liquid was stirred with a T.K homomixer (manufactured by Special Chemical Industry Co., Ltd.) to obtain a dispersion liquid. 60 g of the emulsion containing the above-mentioned seed particles was added to the obtained dispersion, and the mixture was stirred at 30°C for 1 hour to allow the seed particles to absorb the monomer mixture. Secondly, the absorbed monomer mixture was heated at 50°C for 5 hours under a nitrogen stream and polymerized, and then cooled to room temperature (about 25°C) to obtain polymer particles (organic particles 14) and lauryl sulfuric acid attached to the surface. Emulsion of sodium complex. The solid content concentration of the obtained organic fine particles 14 was 20%.

[Production of Optical Film 23] (Example 15) In the production of the organic microparticles 1 in the aforementioned optical film 1, the amount of tertiary dodecyl mercaptan, the polymerization temperature, and the stirring time are adjusted to produce organic microparticles 15 with an average particle diameter of 8 nm. In addition, an optical film 23 was produced in the same manner as the aforementioned optical film 6.

[Production of Optical Film 24] (Example 16) In the production of the organic microparticles 1 in the aforementioned optical film 1, the amount of tertiary dodecyl mercaptan, the polymerization temperature, and the stirring time were adjusted to produce organic microparticles 16 with an average particle diameter of 550 nm. In addition, an optical film 24 was produced in the same manner as the aforementioned optical film 6.

[Production of Optical Film 25] (Example 17) In the preparation of the dope containing organic fine particles of the aforementioned optical film 1, the composition of the dope was changed as follows. In addition, an optical film 25 was produced in the same manner as the aforementioned optical film 6.

(The composition of the thick liquid) Polymer made from the aforementioned alicyclic hydrocarbon monomer: 99.92 parts by mass Dichloromethane: 250.0 parts by mass Ethanol: 20.0 parts by mass 3% by mass organic fine particle additive liquid: 2.7 parts by mass (amount of fine particles: 0.08 parts by mass) The solid content in the above-mentioned dope has a composition of a polymer (98.92% by mass) made of alicyclic hydrocarbon monomers and organic particles (0.08% by mass).

[Production of Optical Film 26] (Example 18) The preparation of the organic microparticle additive liquid of the aforementioned optical film 1 and the preparation and modification of the organic microparticle-containing concentrated liquid are as follows. In addition, an optical film 26 was produced in the same manner as the aforementioned optical film 6.

＜Preparation of organic microparticle additive solution＞ The following materials were stirred and mixed with a disperser for 50 minutes, and then dispersed by Manton-Gaulin. This was filtered with Finemate NM5P-2400 manufactured by Nippon Seiki Co., Ltd. to prepare an organic fine particle additive liquid with an organic fine particle content of 20.0% by mass. The aforementioned organic fine particles 1:20 parts by mass Dichloromethane: 80 parts by mass

<Preparation of Dope Containing Organic Microparticles> Dichloromethane and ethanol are put into the pressure dissolution tank in advance. Next, a polymer containing an alicyclic hydrocarbon monomer is poured into the pressure dissolution tank while stirring, and 20% by mass of the organic fine particle additive liquid is added to prepare a dope with the following composition. Use Azumi filter paper No.244 (filtration accuracy 7μm) made by Azumi filter paper (stock), and filter it with a filtration flow of 300L/m ² ･h and a filter pressure of 1.0×10 ⁶ Pa.

(The composition of the thick liquid) Polymer containing the aforementioned alicyclic hydrocarbon monomer: 78.0 parts by mass Dichloromethane: 190.0 parts by mass Ethanol: 20.0 parts by mass 20% by mass organic fine particle additive liquid: 110.0 parts by mass (amount of fine particles: 22.0 parts by mass) The solid content in the above-mentioned dope has a composition containing alicyclic hydrocarbon monomer polymer (78.0% by mass) and organic microparticles (22.0% by mass).

[Determination of Surfactant Content in Optical Film] After the obtained optical film is freeze-dried and pulverized, it is subjected to ultrasonic extraction with methanol, and after centrifugal separation, the methanol soluble fraction is dried and the quality is determined. Subsequently, the above-mentioned dry solidified product was dissolved in deuterated methanol added with 1,4-bis(trimethylsilyl)benzene-d4 as an internal standard. The above-mentioned dissolved solution was used with NMR device: ECZ-400S (JEOL (400MHz manufactured by RESONANCE), measured under the following conditions, calculated the surfactant content from the proton strength derived from the surfactant structure and the internal standard strength, and shown in the table below. Observation core: 1H Pulse width: 5.6μs (45° pulse) Pulse delay time: 15s The cumulative number of determinations: 64 times

＜Calculation of the difference in refractive index between organic fine particles and polymer＞ For the organic microparticles and polymers used in each optical film, the refractive index difference was calculated from the previously measured refractive index value and shown in the table below.

[Evaluation] ＜Substrate contamination＞ After the completion of the film formation of each optical film, the contamination status on the cast substrate (stainless steel ring support) was visually observed, and the substrate contamination was evaluated based on the following criteria. ◎: No pollution at all. ○: It is invisible under normal light source illumination, but if it is illuminated under green point light source, pollution is visible. △: Slightly contaminated. ×: Contamination is obvious in the self-forming film.

＜Internal turbidity＞ A few drops of glycerin were dropped on both sides of each optical film made, and 2 glass plates (microslide glass article number S 9111, manufactured by MATSUNAMI) with a thickness of 1 mm were sandwiched from both sides. The optical film sandwiched by glass plates on both sides is completely optically adhered to two glass plates. In this state, according to JIS K-7136, the haze (Ha) is NDH-2000 (manufactured by Nippon Denshoku Industries Co., Ltd.). The light source uses a 5V9W halogen bulb, and the light-receiving part is set as a silicon photoelectric unit (with a specific sensitivity filter), and the turbidity is measured under the condition of 23℃･55%RH. Next, only a few drops of glycerin were dropped between two glass plates and sandwiched, and the glass haze (Hb) was measured. Next, the value of glass haze (Hb) is subtracted from the value of haze (Ha) to calculate the internal haze value. In order to be used as an optical film, if the internal haze is greater than 0.1%, it is inferior in terms of transparency. It is preferably 0.05% or less, and more preferably 0.02% or less.

＜Friction＞ (Measurement of dynamic friction coefficient μ) Cut and remove 15 cm from both ends of each optical film in the width direction. From the central part of the optical film in the width direction after slitting, test pieces with a size of 80 mm in the film winding direction × 200 mm in the width direction are cut out one by one. According to JIS K7125 (1987), superimpose two test pieces on a horizontal surface, load a weight of 200g on them, and test the upper side of the overlapping test pieces at a moving speed of 100mm/min and a contact area of 80mm×200mm The sheet was pulled horizontally, and the average load F during the movement of the upper test piece was measured, and the dynamic friction coefficient μ of the both ends of the optical film in the width direction was calculated by the following formula, and is shown in the following table. Dynamic friction coefficient μ=F(g)/weight weight(g) When the aforementioned dynamic friction coefficient μ is 0.7 or less, there is no practical problem.

＜Polarizer adhesion＞ (Making of Polarizer) A polyvinyl alcohol film with a thickness of 120 μm is uniaxially stretched (temperature 110°C, stretching ratio 5 times). This was immersed in an aqueous solution of 0.075 g of iodine, 5 g of potassium iodide, and 100 g of water for 60 seconds. Next, it was immersed in a 68°C aqueous solution made up of 6 g of potassium iodide, 7.5 g of boric acid, and 100 g of water. This was washed with water and dried to obtain a polarizer with a thickness of 5 μm.

(Adhesive preparation) After mixing the following components, defoaming is performed to prepare an ultraviolet curable adhesive. In addition, the triarylphosphonium hexafluorophosphate system is used as a 50% by mass propylene carbonate solution, and is constructed as follows. The triarylphosphonium hexafluorophosphate system is represented by the solid content. 3,4-Epoxycyclohexylmethyl-3,4-epoxycyclohexane carboxylate: 45 parts by mass EPOLEAD GT-301 (alicyclic epoxy resin manufactured by DAICEL Chemical Company): 40 parts by mass 1,4-Butanediol diglycidyl ether: 15 parts by mass Triarylphosphonium hexafluorophosphate: 2.3 parts by mass 9,10-Dibutoxyanthracene: 0.1 parts by mass 1,4-diethoxynaphthalene: 2.0 parts by mass

(Production of Polarizing Plate) The surface of the optical film produced above is subjected to corona discharge treatment. In addition, the corona discharge treatment conditions were a corona output intensity of 2.0 kW and a linear velocity of 18 m/min. Next, on the corona discharge treatment surface of the polarizing plate protective film, the above-prepared ultraviolet curable adhesive is applied with a bar coater so that the cured film thickness becomes approximately 3 μm to form an ultraviolet curable adhesive layer. The polarizer produced above is bonded on the obtained ultraviolet curable adhesive layer. In addition, KONICA MINOLTA TAC KC2UA (thickness 25 μm, manufactured by KONICA MINOLTA) was subjected to corona discharge treatment under the same conditions as described above. Next, on the corona discharge treatment surface of the KC2UA, the prepared ultraviolet-curing adhesive was applied with a bar coater so that the cured film thickness became about 3 μm to form an ultraviolet-curing adhesive layer. Next, the KC2UA UV-curing adhesive layer and the polarizer that is bonded on one side of the optical film produced above are bonded together to obtain the optical film/ultraviolet-curing adhesive layer/polarizer/ultraviolet-curing type produced as described above. Adhesive layer/Laminate of the above-mentioned KC2UA laminate structure. From both sides of the obtained laminate, use an ultraviolet irradiation device with a conveyor belt (the lamp is a D bulb manufactured by FUSION UV SYSTEMS), and ^{irradiate ultraviolet rays with a cumulative light amount of 750mJ/cm 2 to} make each ultraviolet-curing adhesive The layer is hardened to obtain a polarizing plate. The adhesion between the optical film and the polarizer was evaluated based on the following evaluation criteria. ⊚: No peeling at all. ○: Peeling off slightly, but the film is immediately broken. △: Very resistant, but can peel off if peeled off very carefully. ×: The solution peeled off.

＜Durability of Polarizer＞ After exposing the polarizing plate obtained above to a humid environment at 80°C and 90%RH for 500 hours, the polarizing plate was taken out, and the temperature and humidity were adjusted at 23°C and 55%RH for 24 hours. Subsequently, the discoloration of the polarizer was visually observed, and the durability of the polarizer was evaluated according to the following criteria. ⊚: No change in color tone is seen in the polarizer. ○: The polarizer is slightly discolored, but it is of good quality. △: Fading is seen in the polarizer, but it is a practically acceptable quality. ×: The color of the polarizer hardly remains due to xenon light irradiation.

As can be seen from the results shown above, the optical film of the present invention has no deterioration in internal haze compared with the optical film of the comparative example, and the transportability of the film is good. When used as a polarizing plate, the optical film and the polarizer can be prevented from peeling off, and It can prevent the deterioration of the polarizer under damp and heat durable conditions.

10: Liquid crystal display device 30: liquid crystal cell 50: The first polarizer 51: 1st polarizer 53: Protective film (F1) 55: Protective film (F2) 70: 2nd polarizing plate 71: 2nd polarizer 73: Protective film (F3) 75: Protective film (F4) 90: Backlight

[Fig. 1] An example of the structure of the liquid crystal display device of the present invention is shown

Claims (7)

An optical film containing organic microparticles, at least a polymer composed of an alicyclic hydrocarbon monomer having a polar group, or at least a polymer composed of a (meth)acrylic monomer, which is characterized by Contains surfactant in the range of 0.01~1ppm, The aforementioned organic microparticles contain at least a polymer composed of (meth)acrylic monomers, The solubility of the aforementioned surfactant to ethanol at 23°C is 0.2-10% by mass, the solubility to dichloromethane is less than 7% by mass, and the solubility to water is more than 7% by mass. The optical film of claim 1, wherein the aforementioned surfactant is an anionic surfactant. The optical film of claim 1 or 2, wherein the refractive index difference between the aforementioned polymer containing alicyclic hydrocarbon monomer having a polar group or the polymer containing (meth)acrylic monomer and the aforementioned organic microparticle is 0.01 or less . The optical film according to any one of claims 1 to 3, wherein the average particle diameter of the aforementioned organic particles is in the range of 10 to 500 nm. The optical film according to any one of claims 1 to 4, wherein the content of the aforementioned organic fine particles is in the range of 0.1-20% by mass relative to the total mass of the optical film. A method for manufacturing an optical film, which is a method for manufacturing an optical film as claimed in any one of claims 1 to 5, characterized by As the aforementioned organic fine particles, organic fine particles that have been treated to remove the surfactant present in the surroundings are used. The method for manufacturing an optical film according to claim 6, wherein organic fine particles in which the surfactant has been removed by alcohol in an emulsion synthesized by emulsion polymerization of the organic fine particles are used.

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