KR20160079391A - Polymer particles, production method for polymer particles, and its application - Google Patents

Abstract

The present invention provides polymer particles, a method for producing the polymer particles, and a use of the same. The polymer particles can be uniformly distributed in a dispersion liquid and can be sufficiently coagulated when a dispersion liquid is volatilized. The polymer particles according to the present invention comprise: a constituent unit derived from a monomer containing a hydroxyl group represented by chemical formula 1 and/or chemical formula 2; a constituent unit derived from a mono-functional (meth)acrylic monomer; a constituent unit derived from a mono-functional styrene-based monomer, and a constituent unit derived from a cross-linking monomer. A volume average particle diameter thereof is 5 μm or smaller, and a hydroxyl group valence is 5.0 to 15 mgKOH/g, inclusive.

Description

TECHNICAL FIELD [0001] The present invention relates to a polymer particle, a method for producing the polymer particle,

TECHNICAL FIELD The present invention relates to polymer particles usable as raw materials for members such as antiglare films and optical members such as light diffusion films, a method for producing polymer particles, and uses thereof.

Polymer particles are used in a wide range of fields such as liquid crystal spacers, chromatography fillers, diagnostic reagents and the like. In addition, it is also used in various device fields such as a display device as an optical member such as a light diffusion plate, a light diffusion film, an antiglare film and the like. When such polymer particles are provided for practical use, such polymer particles are used in the form of a dispersion in which polymer particles are dispersed in a solvent solvent such as water or an organic solvent, or a paint in which a resin component such as a binder resin is added in addition to the dispersion There are many cases.

In the optical member used in the display device, for example, anti-glare film is required to have anti-glare function. The anti-glare function is realized by scattering external light by fine irregularities formed by polymer particles. In particular, in order to realize a high-quality anti-glare function, it is required to form homogeneous and fine irregularities throughout the antiglare film.

In the formation of fine irregularities, first, the polymer particles are uniformly dispersed in the dispersion containing the solvent and the binder resin without aggregation. Then, the dispersion is applied to the surface of a film base or the like, and the solvent is evaporated by drying. Thereby, polymer particles gather on the film substrate to form a similar coagulation state, whereby fine irregularities are formed.

As such particles, magnetically cohesive particles are disclosed in Patent Document 1. [ Also, Patent Document 2 discloses polymer particles having high hydrophilicity obtained by polymerizing a polymerizable vinyl monomer to seed particles containing a hydrophilic macromonomer as particles having excellent dispersibility.

Japanese Laid-Open Patent Publication No. 2013-231133 Japanese Laid-Open Patent Publication No. 2012-062389

However, with the recent trend toward high definition and thin film display devices, the quality of optical films such as anti-glare film is also diversified, and uniform dispersion of the alcohol-based solvent on the particles used for optical films is required . Here, development of sufficient particles after uniformly dispersed in an alcohol solvent solvent and after coating is desired.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide polymer particles which can be uniformly dispersed in a dispersion liquid and sufficiently aggregated when the dispersion liquid is volatilized.

Another object of the present invention is to provide a process for producing the polymer particles, a dispersion containing the polymer particles, and an optical film coated with the dispersion.

The present inventors have reached the present invention, in which various monomers including a predetermined hydroxyl group-containing monomer are polymerized to bring the numerical values such as the volume average particle diameter and the hydroxyl group value into a predetermined range, thereby solving the above-mentioned problems. That is, the present invention is as follows.

The polymer particle according to the present invention is a polymer particle comprising a constituent unit derived from a hydroxyl group-containing monomer represented by the following formula (1) and / or a following formula (2), a constituent unit derived from a monofunctional (meth) A monomer and a constituent unit derived from a crosslinkable monomer, and has a volume average particle diameter of 5 占 퐉 or less and a hydroxyl value of 5.0 mgKOH / g or more and 15 mgKOH / g or less.

(In the formula (1), R represents H or CH ₃ , m represents a number of 0 to 50, n represents a number of 0 to 50, and m and n are not simultaneously 0)

(In the formula (2), each R independently represents H or CH ₃ , and p represents a number of 1 to 50)

Therefore, the polymer particles according to the present invention are uniformly dispersed in the dispersion and aggregate sufficiently when the dispersion is volatilized.

A method for producing polymer particles according to the present invention is a method for producing polymer particles by polymerizing a vinyl monomer to produce polymer particles, wherein the vinyl monomer is a monomer having a hydroxyl group-containing monomer represented by the following formula (1) and / or (2) , A monofunctional (meth) acrylic monomer, a monofunctional styrene monomer, and a crosslinkable monomer, wherein the hydroxyl group-containing monomer is contained in an amount of 3 to 15% by weight based on the total amount of the vinyl monomer do.

(In the formula (1), R represents H or CH ₃ , m represents a number of 0 to 50, n represents a number of 0 to 50, and m and n are not simultaneously 0)

(In the formula (2), each R independently represents H or CH ₃ , and p represents a number of 1 to 50)

Therefore, the polymer particles prepared by the process for producing polymer particles according to the present invention are uniformly dispersed in the dispersion and aggregate sufficiently when the dispersion is volatilized.

The dispersion according to the present invention comprises the polymer particles and a binder, and the polymer particles are dispersed as a dispersion.

Therefore, in the dispersion according to the present invention, when the polymer particles are uniformly dispersed and applied to an object such as a substrate film and dried, the polymer particles sufficiently aggregate.

The optical film according to the present invention is characterized in that the dispersion is applied onto a base film.

Therefore, when the optical film according to the present invention is applied and dried, the polymer particles sufficiently aggregate, and homogeneous and fine irregularities are formed.

In the polymer particles, the method for producing polymer particles, the dispersion liquid and the optical film according to the present invention, light is scattered by fine irregularities formed by polymer particles when used as a film having antifogging properties, It is possible to prevent the above-mentioned problems.

1 is an image showing the dispersion state of the polymer particles of Example 1 in the alcohol solvent dispersion test.
2 is an image showing the dispersion state of the polymer particles of Example 1 in the alcohol solvent dispersion test.
3 is an image showing the dispersion state of the polymer particles of Comparative Example 2 in the alcohol solvent dispersion test.
4 is an image showing the dispersion state of the polymer particles of Comparative Example 2 in the alcohol solvent dispersion test.

Hereinafter, the present invention will be described in detail.

[Polymer particle]

The polymer particles according to the present invention are used in the field of display devices as optical members, such as diffusion plates, light diffusion films, antiglare films and the like. The polymer particle according to the present invention is a polymer particle comprising a constituent unit derived from a hydroxyl group-containing monomer represented by the following formula (1) and / or a following formula (2), a constituent unit derived from a monofunctional (meth) A constituent unit derived from a monomer, and a constituent unit derived from a vinyl monomer such as a crosslinkable monomer.

(In the formula (1), R represents H or CH ₃ , m represents a number of 0 to 50, n represents a number of 0 to 50, and m and n do not become 0 at the same time. And n are all preferably from 1 to 30).

(In the formula (2), each R independently represents H or CH ₃ , and p represents a number of 1 to 50. p is preferably 1 to 30.)

Among the above monomers, commercially available products of the hydroxyl group-containing monomers represented by the formula (1) include, for example, "BLEMMER (registered trademark)" series manufactured by Nichiyu Corporation. In addition, the "block remmeo (trademark)" series from, "block remmeo (R) 50PEP-300" as a mixture of a compound of a plurality of types represented by (Chemical Formula (1), R is CH _3, m is an average (A mixture of a plurality of compounds represented by the above formula (1), wherein R is CH ₃ , m is an average of about 3.5, and n is about 2.5 on average), "Blemmer TM 70PEP- (A mixture of a plurality of compounds represented by the above formula (1), wherein R is CH ₃ , m is 0, and n is an average of about 2), "Blemmer (registered trademark) PP- , n as a mixture comprising the compound of a plurality of types shown to be about 4 to 6 would), "block remmeo (R) PP-500" (the above formula (1), to the average, R is CH _3, m is 0, n is about 9 on average), "Blemmer (registered trademark) PP-800" (mixture of plural kinds of compounds represented by the above formula (1) (R is CH ₃ , m is 0 and n is about 13 on average), "Blemmer TM PE-90" (a mixture of plural kinds of compounds represented by the above formula (1) is CH _3, as a mixture of m average by comprising a plurality of kinds of compounds represented by one of about 2, n is 0), "block remmeo (R) PE-200" (the general formula (1), R is CH ₃ , as a mixture of m average by comprising a plurality of kinds of compounds represented by one of about 4.5, n is 0), "block remmeo (R) PE-350" (the general formula (1), R a is CH _3, m About 8 on average, and n is 0), and the like are preferable for the present invention. These may be used singly or in combination of two or more.

Examples of commercially available products of the hydroxyl group-containing monomers represented by the formula (2) include "Fraxel (registered trademark) FM" series manufactured by Daicel Co., Ltd. Among the "Fraxel (registered trademark) F" series, Fraxel (registered trademark) FM2D (the compound represented by the above formula (2), R is CH ₃ and p is 2) A compound represented by the formula (2) wherein R is CH ₃ and p is 3) and the like are preferable for the present invention. These may be used alone or in combination of two or more.

The monofunctional (meth) acrylic monomer is a (meth) acrylic monomer having one ethylenic unsaturated group. Examples of monofunctional (meth) acrylic monomers include methyl (meth) acrylate, ethyl (meth) acrylate, n-butyl (meth) acrylate, isobutyl (meth) acrylate, tert- (Meth) acrylic acid alkyl monomers such as ethylhexyl, n-octyl (meth) acrylate, isonyl (meth) acrylate, lauryl (meth) acrylate and stearyl (meth) acrylate. In the present specification, "(meth) acrylate" means acrylate or methacrylate, and "(meth) acryl" means acryl or methacryl.

Among the monofunctional (meth) acrylic monomers, when a monofunctional (meth) acrylic monomer having a water solubility of 0.45 wt% or less at 25 DEG C is used, it is difficult for the hydroxyl group-containing monomer represented by the formula (1) , It is easy to be present in the surface layer, and therefore it is preferable from the viewpoint of alcohol dispersibility.

Specific examples include n-butyl (meth) acrylate, isobutyl (meth) acrylate, tert-butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, n-octyl N-butyl acrylate, lauryl (meth) acrylate and stearyl (meth) acrylate. Of these, n-butyl (meth) acrylate, isobutyl (meth) acrylate and tert-butyl (meth) acrylate are particularly preferable. The monofunctional (meth) acrylic monomer is preferably contained in an amount of 30 to 95% by weight based on the total amount of the monofunctional (meth) acrylic monomer and the monofunctional styrene monomer, from the viewpoint of alcohol dispersibility.

In this specification, the solubility in water is measured by the following method.

(Method for measuring solubility in water)

Water and the monofunctional (meth) acrylic monomer are mixed at a weight ratio of 1: 1 and stirred at 25 캜 for 30 minutes. The aqueous phase and the aqueous phase were separated using a separatory funnel, and the amount (wt%) of the monofunctional (meth) acrylic acid monomer dissolved in the aqueous phase was measured by high performance liquid chromatography (HPLC).

The monofunctional styrene-based monomer is a styrene-based monomer having one ethylenic unsaturated group. Examples of the monofunctional styrene-based monomer include styrene,? -Methylstyrene, vinyltoluene, and ethylvinylbenzene. Among them, styrene is preferable in view of alcohol dispersibility and polymerization reactivity.

The crosslinkable monomer is a polyfunctional monomer having a plurality of ethylenic unsaturated groups and has a function as a crosslinking agent. Examples of the crosslinkable monomer include trimethylolpropane triacrylate, ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, triethylene glycol dimethacrylate, decaethylene glycol dimethacrylate, pentadecaethylene glycol dimethacrylate, (Meth) acrylic monomers such as acrylate, methacrylate, acrylate, acrylate, acrylate, acrylate, acrylate, acrylate, , Divinyl-based monomers such as divinylbenzene, divinylnaphthalene, N, N-divinyl aniline, divinyl ether, divinyl sulfide and divinyl sulfonic acid.

The polymer particles according to the present invention having the above-described monomer as a constituent unit preferably contain 3 to 15% by weight of a hydroxyl group-containing monomer as a constituent unit, and further preferably contain 3 to 35% by weight of a crosslinkable monomer. When the content of the hydroxyl group-containing monomer is less than 3% by weight, the dispersibility in a hydrophilic organic solvent such as an alcohol-based solvent is insufficient and the workability of the coating may be lowered. When the content is more than 15% by weight, There is a case where a desired aggregation state is not obtained after coating and drying. When the amount of the crosslinkable monomer is less than 3% by weight, the degree of crosslinking of the resin particles is low. As a result, when the resin particles are mixed with the binder and coated as a dispersion, the viscosity of the dispersion is increased due to the swelling of the resin particles, which may lower the workability of the coating. When the amount of the crosslinkable monomer is more than 35% by weight, the improvement of the effect suited to the amount of use of the crosslinkable monomer is not observed, and the production cost may increase.

Further, the polymer particles according to the present invention are synthesized so that the volume average particle diameter is 5 탆 or less. The volume average particle diameter can be measured by, for example, a Coulter counter method.

When the polymer particles are processed into a thin film by coating and drying by setting the volume average particle diameter to 5 mu m or less, the polymer particles are agglomerated in an appropriate amount to form a desired convex portion. Further, by setting the thickness to 1 탆 or more and 5 탆 or less, a preferable convex portion is formed.

When the volume average particle diameter of the polymer particles is larger than 5 占 퐉, for example, when the polymer particles are used as the surface antiglare film of a display device, the convex portions formed by agglomeration of the polymer particles are disturbed, The display surface may become white. When the volume average particle diameter of the polymer particles is smaller than 1 占 퐉, for example, when used as a surface antiglare film of a display device, convex portions formed by agglomeration of the polymer particles are flattened, so that external light can not be scattered , The glare on the display surface can not be suppressed.

The coefficient of variation (CV) of the particle diameter of the polymer particles is preferably 15% or less. As a result, when polymer particles are used for the optical member such as the antiglare film or the light diffusion film, the optical characteristics such as the retardation and optical diffusibility of the optical member can be improved.

The polymer particles according to the present invention are synthesized so that the hydroxyl value of the polymer particles is 5.0 mgKOH / g or more and 15 mgKOH / g or less. Further, the hydroxyl value can be measured by a quantitative analysis method (JIS K 0070), for example, a hydroxyl group.

When the polymer particles have a hydroxyl value of 5.0 to 15 mgKOH / g, they can be appropriately dispersed in a hydrophilic organic solvent when they are dispersed in a hydrophilic organic solvent such as an alcohol-based solvent together with a binder. In other words, the polymer particles according to the present invention can be uniformly dispersed without agglomeration, and when they are applied and dried, they are not excessively dispersed and cause no aggregation failure.

By homogeneously dispersing in a hydrophilic organic solvent, for example, when forming an optical film such as an antiglare film, it becomes possible to form a uniform thin film having no unevenness. Further, by preventing cohesion failure, it is possible to form fine irregularities, and scattering of external light such as light emitted from an external fluorescent lamp can be improved to improve glare prevention.

When the polymer particles have a volume average particle diameter of 5 탆 or less, when they are coated and dried to form a thin film, the polymer particles aggregate in an appropriate amount to form a desired convex portion.

When the volume average particle diameter of the polymer particles is larger than 5 占 퐉, for example, when used as the surface antiglare film of a display device, the convex portions formed by agglomeration of the polymer particles are changed, so that the external light is excessively scattered , The display surface may become white.

The quantitative and qualitative determination of the constituent units derived from each monomer in the polymer particles can be confirmed by using analytical methods such as gas chromatography, liquid chromatography, infrared spectroscopy (IR) and nuclear magnetic resonance spectroscopy (NMR). The weight ratio of each monomer in the monomer mixture and the weight ratio of the constituent units derived from each monomer in the polymer particles are approximately the same.

[Method for producing polymer particles]

Hereinafter, a method for producing polymer particles according to the present invention will be described. The polymer particles according to the present invention are preferably prepared by seed polymerization. By the seed polymerization, deviation of the particle diameter can be suppressed. By suppressing the deviation of the particle diameter, it is possible to improve optical properties such as diffusibility and light diffusibility when used as an optical film such as an antiglare film or a light diffusion film. However, the production of the polymer particles according to the present invention is not limited to the seed polymerization, but may be carried out by a polymerization method such as emulsion polymerization or suspension polymerization.

The seed polymerization is a method of carrying out polymerization by using seed particles composed of a polymer obtained by polymerizing a monomer such as a vinyl monomer. Specifically, seed particles are prepared and seed particles produced in an aqueous medium are mixed with other monomers And the monomer absorbed in the seed particle is polymerized.

In the seed polymerization, first, seed particles are added to an emulsion (suspension) containing a monomer for seed polymerization, an aqueous medium and a surfactant.

Examples of the monomer for seed polymerization include a vinyl monomer, for example, a mixture of a monofunctional (meth) acrylic monomer, a monofunctional styrene monomer, a monofunctional (meth) acrylic monomer and a monofunctional styrene monomer.

As the aqueous medium, for example, water; Lower alcohols (alcohols having 5 or less carbon atoms) such as methyl alcohol, ethyl alcohol and the like; A mixture of water and a lower alcohol, and the like.

As the surfactant, any of an anionic surfactant, a cationic surfactant, a nonionic surfactant and a zwitterionic surfactant may be used.

Examples of the anionic surfactant include fatty acid soaps such as sodium oleate and castor oil potassium soap; Alkyl sulfuric acid ester salts such as sodium lauryl sulfate and ammonium lauryl sulfate; Alkylbenzene sulfonic acid salts such as sodium dodecylbenzenesulfonate; Alkylnaphthalenesulfonic acid salts, alkanesulfonic acid salts, dialkylsulfosuccinates such as sodium di (2-ethylhexyl) sulfosuccinate and sodium dioctylsulfosuccinate; Alkenylsuccinates (dipotassium salts); Alkyl phosphoric acid ester salts; Naphthalenesulfonic acid formalin condensate; Polyoxyethylene alkyl phenyl ether sulfuric acid ester salts; Polyoxyethylene alkyl ether sulfate such as polyoxyethylene lauryl ether sodium sulfate; Polyoxyethylene alkyl sulfates and the like.

Examples of the nonionic surfactant include polyoxyethylene alkyl ether such as polyoxyethylene tridecyl ether, polyoxyethylene alkyl phenyl ether such as polyoxyethylene octyl phenyl ether, polyoxyethylene styrenated phenyl ether, alkyl A polyoxyalkylene alkyl ether such as a polyoxyalkylene tridecyl ether having a carbon number of 3 or more of the phenoxyethylene group, a polyoxyethylene sorbitan fatty acid such as a polyoxyethylene fatty acid ester, a sorbitan fatty acid ester, and monolauric polyoxyethylene sorbitan Esters, polyoxyethylene alkylamines, glycerin fatty acid esters, oxyethylene-oxypropylene block polymers, and the like.

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

Examples of the amphoteric surfactants include lauryldimethylamine oxide, phosphate ester surfactants, and phosphorous ester surfactants. These surfactants may be used alone or in combination of two or more.

The amount of the surfactant used in the seed polymerization is preferably in the range of 0.01 to 5 parts by weight based on 100 parts by weight of the monomer for seed polymerization. If the amount of the surfactant used is less than the above range, the polymerization stability may be lowered. When the amount of the surfactant used is larger than the above range, the cost of the surfactant component increases.

The emulsion to be added can be prepared by a known method. For example, an emulsion can be obtained by adding a monomer and a surfactant to an aqueous medium and dispersing the emulsion in a microemulsifier such as a homogenizer, an ultrasonic processor, or a nanometer. As the aqueous medium, water or a mixture of water and an organic solvent solvent (for example, a lower alcohol (an alcohol having 5 or less carbon atoms)) can be used.

The seed particles may be added to the emulsion as it is, or may be added to the emulsion in the form dispersed in an aqueous medium. After the seed particles for seed polymerization are added to the emulsion, the seed polymerization monomers are absorbed by the seed particles. This absorption can be usually carried out by stirring the emulsion at room temperature (about 20 ° C) for 1 to 12 hours. In order to accelerate the absorption of the monomer for seed polymerization to the seed particles, the emulsion may be heated to about 30 to 50 캜.

The seed particles swell by absorbing the monomer. The mixing ratio of the monomer for seed polymerization and the seed particle to be absorbed is preferably in the range of 5 to 300 parts by weight and more preferably in the range of 100 to 250 parts by weight based on 1 part by weight of the seed particles. If the mixing ratio of the adsorbing monomer for seed polymerization is less than the above range, the increase of the particle diameter due to polymerization becomes small, and the production efficiency is lowered. On the other hand, if the mixing ratio of the monomer for seed polymerization which is absorbed is larger than the above range, the seed polymerization monomer is not completely absorbed by the seed particles, and suspension polymerization is carried out independently in the aqueous medium to produce polymer particles having a small particle diameter . The completion of the absorption of the seed polymerization monomer to the seed particle can be judged by confirming the enlargement of the particle diameter by observing the optical microscope.

The polymer particles according to the present invention can be obtained by polymerizing the monomer absorbed in the seed particles. The polymer particles according to the present invention may be obtained by repeating the step of polymerizing the monomer by absorbing the seed particles several times.

A polymerization initiator may be added to the monomer for seed polymerization to be polymerized if necessary. The polymerization initiator may be mixed with the monomer to be polymerized and then the resulting mixture may be dispersed in an aqueous medium. Alternatively, both of the monomer for seed polymerization to be polymerized with the polymerization initiator may be separately dispersed in an aqueous medium. It is preferable that the particle diameter of the droplet of the monomer for seed polymerization present in the obtained emulsion is made smaller than the particle diameter of the seed particle because the monomer is efficiently absorbed by the seed particle.

Examples of the polymerization initiator include, but are not limited to, benzoyl peroxide, lauroyl peroxide, o-chloro benzoyl peroxide, o-methoxy benzoyl peroxide, 3,5,5-trimethylhexanoyl peroxide, t- Organic peroxides such as butyl peroxy-2-ethylhexanoate and di-tert-butyl peroxide; (2,4-dimethylvaleronitrile), 2,2'-azobis (2,3-dimethylbutyronitrile), 2,2'-azobisisobutyronitrile, 2,2'- Azobis (2-methylbutyronitrile), 2,2'-azobis (2,3,3-trimethylbutyronitrile), 2,2'-azobis (2-isopropylbutyronitrile) Azobis (cyclohexane-1-carbonitrile), 2,2'-azobis (4-methoxy-2,4-dimethylvaleronitrile), (2-carbamoyl azo) iso Azo compounds such as butyronitrile, 4,4'-azobis (4-cyanovaleric acid), and dimethyl-2,2'-azobisisobutylate. The polymerization initiator is preferably used in a range of 0.1 to 1.0 part by weight based on 100 parts by weight of the monomer.

The polymerization temperature for the seed polymerization can be appropriately determined depending on the kind of the monomer for seed polymerization to be polymerized and the kind of the polymerization initiator to be used, if necessary. The polymerization temperature of the seed polymerization is preferably 25 to 110 캜, more preferably 50 to 100 캜. The polymerization time of the seed polymerization is preferably 1 to 12 hours. The polymerization reaction of the seed polymerization may be carried out in an atmosphere of an inert gas (for example, nitrogen) inert to polymerization. The polymerization reaction of the seed polymerization is preferably carried out after the monomer to be polymerized and the polymerization initiator to be used as needed are completely absorbed by the seed particles.

In the seed polymerization, in order to improve the dispersion stability of the polymer particles, a polymer dispersion stabilizer may be added to the polymerization reaction system. Examples of the polymer dispersion stabilizer include polyvinyl alcohol, polycarboxylic acid, cellulose (hydroxyethylcellulose, carboxymethylcellulose, etc.), and polyvinylpyrrolidone. The polymer dispersion stabilizer may be used in combination with an inorganic water-soluble polymeric compound such as sodium tripolyphosphate. Of these polymer dispersion stabilizers, polyvinyl alcohol and polyvinyl pyrrolidone are preferable. The addition amount of the polymer dispersion stabilizer is preferably within a range of 1 to 10 parts by weight based on 100 parts by weight of the monomer for seed polymerization.

In order to suppress the generation of emulsified particles (polymer particles having excessively small particle diameters) in the aqueous medium during the polymerization reaction, nitrite salts such as sodium nitrite, sulfites, hydroquinones, ascorbic acid, water-soluble vitamin B , Citric acid, polyphenols and the like may be added to an aqueous medium. The addition amount of the polymerization inhibitor is preferably in the range of 0.02 to 0.2 parts by weight based on 100 parts by weight of the vinyl monomer.

After completion of the polymerization, the polymer particles obtained by polymerizing the monomer for seed polymerization absorbed in the seed particles in this manner are centrifuged if necessary and the aqueous medium is removed, washed with water and / or solvent, dried and isolated . The method of isolating the polymer particles obtained by the seed polymerization from the aqueous medium is not particularly limited, and examples thereof include a spray drying method typified by a spray dryer, a method of attaching the polymer particles to a heated rotating drum represented by a drum dryer, Drying method and the like.

The polymerization method for polymerizing the monomer for seed polymerization so as to obtain seed particles is not particularly limited, but dispersion polymerization, emulsion polymerization, soap-free emulsion polymerization, seed polymerization, suspension polymerization and the like can be used. In order to obtain polymer particles having an approximately uniform particle diameter by seed polymerization, it is first necessary to use these seed particles with substantially uniform particle diameters to grow these particles uniformly. The seed particles having an approximately uniform particle diameter serving as a raw material can be obtained by subjecting a vinyl monomer such as a monofunctional (meth) acrylic monomer or a monofunctional styrene monomer to emulsion polymerization such as soap-free emulsion polymerization (emulsion polymerization without using a surfactant) Can be produced by polymerization by polymerization. Therefore, emulsion polymerization, soap-free emulsion polymerization, seed polymerization and dispersion polymerization are preferable as polymerization methods for obtaining seed particles.

Also in the polymerization for obtaining the seed particles, a polymerization initiator is used if necessary. Examples of the polymerization initiator include persulfates such as potassium persulfate, ammonium persulfate and sodium persulfate; Benzoyl peroxide, lauroyl peroxide, o-chloro benzoyl peroxide, o-methoxy benzoyl peroxide, 3,5,5-trimethylhexanoyl peroxide, tert-butyl peroxy-2-ethylhexanoate, di- Organic peroxides such as butyl peroxide; Azo compounds such as 2,2'-azobisisobutyronitrile, 1,1'-azobiscyclohexanecarbonitrile, and 2,2'-azobis (2,4-dimethylvaleronitrile). have. The amount of the polymerization initiator used is preferably in the range of 0.1 to 3 parts by weight based on 100 parts by weight of the seed polymerization monomer used for obtaining the seed particles. The weight average molecular weight of the obtained seed particles can be adjusted by adjusting the amount of the polymerization initiator used.

In the polymerization for obtaining the seed particles, a molecular weight regulator may be used to adjust the weight average molecular weight of the obtained seed particles. Examples of the molecular weight adjusting agent include mercaptans such as n-octyl mercaptan and tert-dodecyl mercaptan; ? -methylstyrene dimer; terpenes such as? -terpinene and dipentene; And halogenated hydrocarbons such as chloroform and carbon tetrachloride. The weight average molecular weight of the obtained seed particles can be adjusted by adjusting the amount of the molecular weight regulator used.

The polymer particles of the present invention are preferably used as an optical member of an optical film such as an antiglare film or a light diffusion film, and are preferably used as a dispersion by mixing with a binder.

[Production method of optical film]

Next, a method for producing an optical member using the polymer particles according to the present invention will be described. Here, an example of producing an optical film such as an antiglare film as an optical member will be described. In the production of the optical film according to the present invention, a dispersion according to the present invention in which a dispersion medium such as polymer particles according to the present invention is dispersed in a dispersion medium such as a binder is used. Specifically, it can be obtained by coating a dispersion for coating in which a dispersion medium such as polymer particles is dispersed in a dispersion medium such as a binder, on a film substrate and drying the coating dispersion as a coating film on the film substrate.

The binder is not particularly limited as long as it is used in the art depending on required properties such as transparency, polymer particle dispersibility, light resistance, moisture resistance and heat resistance. As the binder, for example, a (meth) acrylic resin; (Meth) acryl-urethane-based resin; Urethane resin; Polyvinyl chloride resins; Polyvinylidene chloride resins; Melamine resin; Styrene type resin; Alkyd resins; Phenolic resin; Epoxy resin; Polyester-based resin; Silicone resins such as alkylpolysiloxane resins; Modified silicone resins such as (meth) acrylic-silicone resins, silicone-alkyd resins, silicone-urethane resins and silicone-polyester resins; And fluorine-based resins such as polyvinylidene fluoride, fluoroolefin vinyl ether polymer and the like.

The binder resin is preferably a curable resin capable of forming a crosslinked structure by a crosslinking reaction from the viewpoint of improving the durability of the coating dispersion. The curable resin can be cured under various curing conditions. The curable resin is classified into an ionizing radiation curable resin such as an ultraviolet ray curable resin and an electron beam curable resin, a thermosetting resin, and a heat curable resin depending on the curing type.

Examples of the thermosetting resin include a thermosetting urethane resin composed of an acrylic polyol and an isocyanate-free polymer, a phenol resin, a urea melamine resin, an epoxy resin, an unsaturated polyester resin, and a silicone resin.

Examples of the ionizing radiation curable resin include polyfunctional (meth) acrylate resins such as polyhydric alcohol polyfunctional (meth) acrylates and the like; Polyfunctional urethane acrylate resins synthesized from (meth) acrylic acid esters having diisocyanate, polyhydric alcohol and hydroxyl group, and the like.

As the ionizing radiation curable resin, a polyether resin, a polyester resin, an epoxy resin, an alkyd resin, a spiroacetal resin, a polybutadiene resin, a polythiol polyene resin and the like having an acrylate functional group may be used.

As the binder resin, in addition to the above-mentioned curable resin, a thermoplastic resin can be used. Examples of the thermoplastic resin include cellulose derivatives such as acetylcellulose, nitrocellulose, acetylbutylcellulose, ethylcellulose, and methylcellulose; Vinyl resins such as homopolymers and copolymers of vinyl acetate, homopolymers and copolymers of vinyl chloride, homopolymers and copolymers of vinylidene chloride, and the like; Acetal resins such as polyvinyl formal, polyvinyl butyral and the like; (Meth) acrylic resins such as homopolymers and copolymers of acrylic acid esters, homopolymers and copolymers of methacrylic acid esters; Polystyrene resin; Polyamide resins; Linear polyester resins; Polycarbonate resin and the like.

In addition to the above-mentioned binder resins, synthetic binders such as synthetic rubbers and natural rubbers, and other inorganic binders may also be used as binders. Examples of the rubber-based binder resin include an ethylene-propylene copolymer rubber, a polybutadiene rubber, a styrene-butadiene rubber, and an acrylonitrile-butadiene rubber.

The dispersion for coating may further contain an organic solvent. There is no particular limitation so long as it is easy to coat the dispersion for coating on the base material by incorporating the organic solvent when coating the dispersion for coating on the substrate such as a film substrate described later. Examples of the organic solvent include aromatic solvent solvents such as toluene and xylene; Alcohol solvent solvents such as methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, isobutyl alcohol and propylene glycol monomethyl ether; Ester solvents such as ethyl acetate and butyl acetate; Ketone solvent solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclopentanone, and cyclohexanone; Glycol ethers such as 2-methoxyethanol, 2-ethoxyethanol, 2-butoxyethanol, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, diethylene glycol dimethyl ether and propylene glycol methyl ether; Glycol ether esters such as 2-methoxyethyl acetate, 2-ethoxyethyl acetate (cellosolve acetate), 2-butoxyethyl acetate and propylene glycol methyl ether acetate; Chlorinated solvents such as chloroform, dichloromethane, trichloromethane and methylene chloride; Ether solvent solvents such as tetrahydrofuran, diethyl ether, 1,4-dioxane, and 1,3-dioxolane; Amide solvents such as N-methylpyrrolidone, dimethylformamide, dimethylsulfoxide and dimethylacetamide can be used. These organic solvents may be used alone or in combination of two or more. Among them, alcoholic solvents having 5 or less carbon atoms are preferable from the viewpoints of uniform dispersibility of the polymer particles in the dispersion and cohesiveness after drying, and more preferred are methanol, ethanol and propanol.

The film substrate is preferably transparent. Examples of the transparent film substrate include polyester polymers such as polyethylene terephthalate (PET) and polyethylene naphthalate, cellulosic polymers such as diacetylcellulose and triacetylcellulose (TAC), polycarbonate polymers, polymethyl And (meth) acrylic polymers such as methacrylate. Examples of the transparent film substrate include styrene polymers such as polystyrene, acrylonitrile and styrene copolymers, olefin polymers such as polyethylene, polypropylene, polyolefins having a cyclic or norbornene structure, ethylene / propylene copolymers, Amide polymers such as nylon and aromatic polyamides, and the like. Further, as the transparent film substrate, it is possible to use an imide polymer, a sulfonic polymer, a polyether sulfone polymer, a polyether ether ketone polymer, a polyphenyl sulfide polymer, a vinyl alcohol polymer, a vinyl chloride polymer, a vinyl butyral polymer, A film using a polymer such as an allylate-based polymer, a polyoxymethylene-based polymer, an epoxy-based polymer, or a blend of these polymers. As the film base material, a material having a small birefringence is preferably used. Further, a film in which a (easy) adhesive layer such as a (meth) acrylic resin, a copolymerized polyester resin, a polyurethane resin, a styrene-maleic acid graft polyester resin, Can be used as a film substrate.

The thickness of the film base material can be suitably determined. In general, it is preferably in the range of 10 to 500 m and in the range of 20 to 300 m in view of workability such as strength, handling, And more preferably in the range of about 200 mu m to about 200 mu m. In addition, additives such as an ultraviolet absorber, an infrared absorber, an antistatic agent, a refractive index adjuster, and an enhancer may be added to the film substrate.

Examples of the method of applying the dispersion for coating on the film substrate include bar coating, blade coating, spin coating, reverse coating, die coating, spray coating, roll coating, gravure coating, microgravure coating, And a coating method known in the art.

Since the optical film according to the present invention constituted as described above is formed by coating a substrate with a dispersion for coating comprising the polymer particles according to the present invention having excellent dispersion stability, And optical properties such as flicker resistance can be stably obtained without unevenness. Therefore, high quality stability is obtained in the optical film according to the present invention.

Example

Hereinafter, the present invention will be described with reference to Examples and Comparative Examples, but the present invention is not limited thereto. First, in the following Examples and Comparative Examples, the method of measuring the variation coefficient of the volume average particle diameter and the particle diameter of the polymer particles, the method of measuring the volume average particle diameter of the seed particles used in the production of the polymer particles, The measurement method of gigas and the alcohol solvent dispersion test will be described.

{Method of measuring the variation coefficient of the volume average particle diameter and the particle diameter of the polymer particles}

The volume average particle diameter of the polymer particles is measured by Coulter Multisizer III (measuring apparatus manufactured by Beckman Coulter, Inc.). The measurement shall be carried out using a calibrated aperture in accordance with the Multisizer (TM) 3 User Manual, published by Beckman Coulter, Inc.

Also, the aperture used for the measurement is appropriately selected according to the size of the particles to be measured. When an aperture having a size of 50 μm is selected, the current (aperture current) is set to -800 and the gain (gain) is set to 4.

As a sample for measurement, 0.1 g of polymer particles were dissolved in 10 ml of a 0.1% by weight nonionic surfactant aqueous solution by using a touch mixer (TOUCHMIXER MT-31, manufactured by Yamato Scientific Co., Ltd.) and an ultrasonic cleaner (ULTRASONIC CLEANER VS -150 ") as a dispersing agent. During the measurement, the inside of the beaker was slowly stirred so as not to contain bubbles, and the measurement was terminated at the time when 100,000 polymer particles were measured. The volume average particle diameter of the polymer particles is an arithmetic mean in the particle size distribution of 100,000 particles.

The coefficient of variation (CV value) of the particle diameter of the polymer particles is calculated by the following equation.

Coefficient of variation of particle diameter of polymer particles = (standard deviation of particle size distribution based on volume of polymer particles / volume average particle diameter of polymer particles) x 100

{Method of measuring volume average particle diameter of seed particles used for production of polymer particles}

The volume average particle diameter of the seed particles used in the production of the polymer particles is measured by a laser diffraction / scattering type particle size distribution measuring apparatus (LS 13 320 manufactured by Beckman Coulter, Inc.) and a universal liquid sample module.

Specifically, 0.1 g of the seed particle dispersion was dispersed in 10 mL of a 0.1 wt% nonionic surfactant aqueous solution by using a touch mixer ("TOUCHMIXER MT-31" manufactured by Yamato Scientific Co., Ltd.) and an ultrasonic cleaner ("ULTRASONIC CLEANER VS- 150 ") as a dispersing agent.

The measurement was carried out in a state in which the seed particles were dispersed by performing pump circulation in the universal liquid sample module and in a state in which the ultrasonic unit (ULM ULTRASONIC MODULE) was activated so that the volume average particle diameter of the seed particles The arithmetic mean diameter of the arithmetic mean of the arithmetic mean. Measurement conditions are shown below.

Medium = water

Refractive index of medium = 1.333

The refractive index of the solid = the refractive index of the seed particle (1.495)

PIDS relative concentration: about 40 to 55%

{Measuring the hydroxyl value of polymer particles}

The hydroxyl value of the polymer particles is measured in accordance with the quantitative analysis method of a hydroxyl group (JIS K 0070-19 92). Specifically, the following procedure is performed.

<Acid value measurement method for measuring hydroxyl group (JIS K 0070)>

2 g of a sample and 20 ml of a pyridine solvent were added to a 200 ml flat bottom flask and dispersed with stirring at room temperature for 1 hour. Three drops of phenolphthalein reagent were added to the flask and titrated with a 0.5 mol / l potassium hydroxide ethanol solution, The ending point is set as the end point. Blank tests are also conducted in the same manner, and the acid value is calculated from the following formula. The measurement is carried out twice, and the average value is measured.

<Calculation of acid value>

Acid value (mgKOH / g) = (V1 - V0) x f x 0.1 x 56.11 ÷ S

only,

S: mass of the sample (g)

V0: Amount (ml) of 0.1 mol / l potassium hydroxide ethanol solution required in the blank test,

                                               ... Blank titration (ml)

V1: The amount (ml) of the 0.1 mol / l potassium hydroxide ethanol solution required in the present test,

... Sample Amount (ml)

f: Factor of 0.1 mol / l potassium hydroxide ethanol solution ... 1.0

<Order of analysis method>

2 g of the sample and 3 ml of the acetylating reagent are added to a 200 ml flat bottom flask, and the mixture is stirred and mixed well. 20 ml of a pyridine solution is further added, and the mixture is stirred for 10 minutes and then reacted in an oil bath at 110 ° C for 1 hour. Thereafter, the mixture was stirred with a shaker for 10 minutes, and after cooling, 1 ml of distilled water was added and reacted in an oil bath at 105 ° C for 10 minutes. Then, 3 drops of the phenolphthalein reagent are added, and the solution is titrated with a 0.5 mol / l potassium hydroxide ethanol solution to give an end point where the reddish purple color is discolored. Further, a blank test is conducted in the same manner, and the hydroxyl value is calculated by the following formula. The measurement is carried out twice, and the average value is taken as the hydroxyl value.

&Lt; Hydroxyl group calculation formula &

(MgKOH / g) = [(V0-V1) x f 占 0.5 占 56.11 占 S] + acid value

only,

S: Weight of sample (g)

V0: Amount (ml) of a 0.5 mol / l potassium hydroxide ethanol solution required in the blank test,

... Amount of blank (ml)

V1: The amount (ml) of 0.5 mol / L potassium hydroxide ethanol solution required in this test,

... Sample volume (ml)

f: a factor of 0.5 mol / l potassium hydroxide ethanol solution ... 1.0

{Alcohol solvent dispersion test}

In the alcohol solvent dispersion test, 0.1 g of the particles and 5 g of methanol or isopropyl alcohol as an alcohol solvent were weighed into a 10 ml ointment bottle made of plastic, and a stirring deaeration machine (Awatore Rentero (AR-100) Ltd., manufactured by TINKISA CO., LTD.) For 3 minutes. After the completion of the stirring, a drop of the dispersion is dropped on a glass plate with an eyedropper, and a cover glass is spread from above. Then, an evaluation test is performed by observing the dispersion state with a digital microscope VHX (manufactured by KYOSEN CO., LTD.). &Quot; &amp; cir &amp; &quot;, &quot; o &quot;, and &quot; x &quot;, respectively, in the case of being dispersed in both methanol and isopropyl alcohol.

{Production Example 1 of Seed Particle}

In a separate flask equipped with a stirrer, a thermometer and a reflux condenser, 3000 g of water as an aqueous medium, 500 g of methyl methacrylate as a monofunctional (meth) acrylic monomer and 5 g of n-octylmercaptan as a molecular weight regulator were introduced, The inside of the separable flask was purged with nitrogen, and the inner temperature of the separable flask was raised to 70 캜. While keeping the internal temperature of the separable flask at 70 캜, 2.5 g of potassium persulfate as a polymerization initiator was added to the contents of the separable flask and polymerization reaction was carried out for 12 hours to obtain an emulsion. The emulsion thus obtained contained 14% by weight of solid matter (polymethylmethacrylate particles), and the solid content thereof was a true spherical particle (seed particle) having a volume average particle diameter of 0.45 탆 and a weight average molecular weight of 15,000. The emulsion containing the spherical spherical particles was used as a seed particle dispersion in Examples and Comparative Examples of the polymer particles described later.

{Production Example 2 of Seed Particle}

A separable flask equipped with a stirrer, a thermometer and a reflux condenser was charged with 600 g of water as an aqueous medium, 70 g of the emulsion obtained in Preparation Example 1 of seed particles, 100 g of methyl methacrylate as the monofunctional (meth) acrylic monomer, octyl mercaptan and the contents of the separable flask were purged with nitrogen while stirring the contents of the separable flask with a stirrer and the inner temperature of the separable flask was raised to 70 캜. Further, 0.5 g of potassium persulfate as a polymerization initiator was added while keeping the inner temperature of the separable flask at 70 占 폚, and polymerization reaction was continued for 8 hours while maintaining the inner temperature of the separable flask at 70 占 폚. Thereby, a seed particle dispersion is obtained. The seed particle dispersion thus obtained contained 14% by weight of solids, and the solids consisted of spherical particles (seed particles) having a volume average particle diameter of 1.01 탆.

{Example 1: Production Example of Polymer Particles}

In a 5 L reactor equipped with a stirrer and a thermometer, 300 g of styrene as monofunctional styrene monomer, 350 g of n-butyl methacrylate (solubility in water at 25 캜, 0.04% by weight) as monofunctional (meth) , 300 g of ethylene glycol dimethacrylate as a crosslinkable monomer and 300 g of poly (ethylene glycol-propylene glycol) monomethacrylate (trade name: Blemmer (registered trademark) 50PEP-300) as a hydroxyl group- 50 g of a mixture of a plurality of compounds represented by the above formula (1), manufactured by Nisshin Oils Co., Ltd., wherein R = CH ₃ , m is 3.5 on average and n is 2.5 on average) And 8 g of 2'-azobisisobutyronitrile were dissolved together to obtain a monomer mixture. The resulting monomer mixture was mixed with 1000 g of a surfactant aqueous solution obtained by dissolving 10 g of polyoxyethylene octyl phenyl ether as a nonionic surfactant in 990 g of ion-exchanged water, and the mixture was dispersed in a high-speed emulsification / dispersing machine (trade name "Homomixer- Manufactured by Primix Co., Ltd.) and treated at 10,000 rpm for 10 minutes to obtain an emulsion. To this emulsion was added 24 g of a seed particle dispersion having a volume average particle diameter of 0.45 mu m (solid content: 3.4 g) obtained in Production Example 1 of the seed particles, and the mixture was stirred at 30 DEG C for 3 hours to obtain a dispersion. To this dispersion, 2000 g of a 4 wt% aqueous solution of polyvinyl alcohol (manufactured by Nippon Synthetic Chemical Industry Co., Ltd., trade name: GOSENOL (registered trademark) GH-17) as a polymer dispersion stabilizer and 0.6 g of sodium nitrite as a polymerization inhibitor Then, the mixture was stirred at 70 ° C for 5 hours and then at 105 ° C for 2.5 hours to effect polymerization reaction. The dispersion liquid after polymerization was dehydrated with a pressure filter, washed with hot water, and vacuum-dried at 70 캜 for 24 hours to obtain polymer particles (A) comprising a crosslinked (meth) acrylic-styrene copolymer resin.

{Example 2: Production example of polymer particles}

, 80 g of styrene as the monofunctional styrene monomer, 700 g of methyl methacrylate as a monofunctional (meth) acrylic monomer (solubility in water of 1.72 wt% at 25 캜), 120 g of divinylbenzene as a crosslinkable monomer, 100 g of poly (ethylene glycol-propylene glycol) monomethacrylate (trade name: Blemmer (registered trademark) 50PEP-300, manufactured by Nichiyu Co., Ltd.) as a hydroxyl group-containing monomer represented by the following formula (1) -Azobisisobutyronitrile were dissolved together to prepare a monomer mixture. A seed particle dispersion was prepared by dissolving 80 g of a seed particle dispersion (solid content: 11.2 g) having the volume average particle diameter of 0.45 占 퐉 obtained in Production Example 1 of the seed particles , Polymer particles (B) were obtained in the same manner as in Example 1.

{Example 3: Production of polymer particles}

240 g of styrene as a monofunctional styrene monomer, 320 g of methyl methacrylate as a monofunctional (meth) acrylic monomer, 300 g of divinylbenzene as a crosslinkable monomer and 100 g of a poly (ethylene glycol) as a hydroxyl group- -Propylene glycol) monomethacrylate (trade name: Blemmer (registered trademark) 50PEP-300, manufactured by Nichiyu Co., Ltd.) and 8 g of 2,2'-azobisisobutyronitrile as a polymerization initiator were dissolved together to prepare a monomer And the seed particle dispersion was changed to 80 g (solid content: 11.2 g) of the seed particle dispersion having the volume average particle diameter of 0.45 탆 obtained in Production Example 1 of the seed particles described above. C).

{Example 4: Production example of polymer particles}

510 g of styrene as a monofunctional styrene monomer, 320 g of n-butyl methacrylate as a monofunctional (meth) acrylic monomer, 120 g of divinylbenzene as a crosslinkable monomer, and 1 g of lactone-modified 50 g of hydroxyethyl methacrylate (product name: "Fraxel (registered trademark) FM2D", manufactured by Daicel Chemical Industries, Ltd., the formula (2), p = 2) and 20 g of 2,2'-azobisisobutyl Except that 8 g of ronitryl was dissolved in each other to prepare a monomer mixture, and 80 g of the seed particle dispersion (solid content: 11.2 g) obtained in Production Example 1 of the seed particles and having a volume average particle diameter of 0.45 탆 was used. 1, polymer particles (D) were obtained.

{Example 5: Production of polymer particles}

80 g of styrene as a styrene monomer, 700 g of n-butyl methacrylate as a (meth) acrylic monomer, 120 g of divinylbenzene as a crosslinkable monomer and 80 g of a poly (ethylene glycol-propylene glycol) monomethacrylate (product name "block remmeo (R) 50PEP-300", you as healing Co., Ltd., a mixture comprising a plurality of compounds represented by the general formula _{(1), R 1 = CH} 3, R 2 = C ₂ H ₅ , R ₃ = C ₃ H ₆ , R ₄ = H, m is 3.5 on average and n is 2.5 on average) and 2,2'-azobisisobutyronitrile (Solid content: 11.2 g) obtained in Production Example 1 of the seed particles and that the seed particle dispersion had a volume average particle diameter of 0.45 mu m and a seed particle dispersion was used as the monomer mixture. In the same manner, (E).

{Example 6: Production of polymer particles}

420 g of styrene as a monofunctional styrene monomer, 230 g of methyl methacrylate as a monofunctional (meth) acrylic monomer, 300 g of divinylbenzene as a crosslinkable monomer and 100 g of a poly (ethylene glycol) as a hydroxyl group- (Product name: BLEMMER (registered trademark) 50PEP-300, manufactured by Nichiyu Co., Ltd.) and 8 g of 2,2'-azobisisobutyronitrile as a polymerization initiator were dissolved together to prepare a monomer And a seed particle dispersion was prepared in the same manner as in Example 1 except that the seed particle dispersion was changed to 107 g (solid content 15.0 g) of the seed particle dispersion obtained in Production Example 2 of the seed particles and having a volume average particle diameter of 1.01 탆, F).

{Comparative Example 1: Comparative Example of Polymer Particles}

300 g of styrene as a monofunctional styrene monomer, 230 g of methyl methacrylate as a monofunctional (meth) acrylic monomer, 300 g of ethylene glycol dimethacrylate as a crosslinkable monomer, 300 g of lactone as a hydroxyl group-containing monomer represented by the above formula (2) 50 g of denatured hydroxyethyl methacrylate (product name: "Fraxel FM2D (registered trademark)" manufactured by Daicel Chemical Industries, Ltd., the above formula (2), n = 2) and 2,2'-azobisisobutane Except that 8 g of butyronitrile was dissolved with respect to each other to prepare a monomer mixture and the seed particle dispersion was changed to 107 g (solid content 15.0 g) of the seed particle dispersion obtained in Production Example 2 of the seed particles and having a volume average particle diameter of 1.01 탆 Polymer particles (G) were obtained in the same manner as in Example 1.

{Comparative Example 2: Comparative Example of Polymer Particles}

200 g of styrene as a monofunctional styrene monomer, 500 g of methyl methacrylate as a monofunctional (meth) acrylic monomer, 300 g of ethylene glycol dimethacrylate as a crosslinkable monomer, and 20 g of 2,2'-azobisisobutyl Except that 8 g of ronitryl was dissolved in each other to prepare a monomer mixture, and 80 g of the seed particle dispersion (solid content: 11.2 g) obtained in Production Example 1 of the seed particles and having a volume average particle diameter of 0.45 탆 was used. 1, polymer particles (H) were obtained.

{Comparative Example 3: Comparative Example of Polymer Particles}

200 g of styrene as a monofunctional styrene monomer, 400 g of methyl methacrylate as a monofunctional (meth) acrylic monomer, 200 g of ethylene glycol dimethacrylate as a crosslinkable monomer, and 200 g of a poly (Ethylene glycol-propylene glycol) monomethacrylate (trade name: BLEMMER (registered trademark) 50PEP-300, manufactured by Nichiyu Co., Ltd.) and 8 g of 2,2'-azobisisobutyronitrile as a polymerization initiator (Solid content: 11.2 g) was used as the monomer mixture, and the seed particle dispersion was changed to 80 g of the seed particle dispersion having the volume average particle diameter of 0.45 μm obtained in Production Example 1 of the seed particles To obtain polymer particles (I).

{Comparative Example 4: Comparative Example of Polymer Particles}

240 g of styrene as a monofunctional styrene monomer, 320 g of methyl methacrylate as a monofunctional (meth) acrylic monomer, 300 g of divinylbenzene as a polymerizable vinyl monomer as a crosslinkable monomer, 300 g of a hydroxyl group-containing 50 g of poly (ethylene glycol-propylene glycol) monomethacrylate (trade name: BLEMMER (registered trademark) 50PEP-300, manufactured by Nichiyu Co., Ltd.) as a monomer and 20 g of 2,2'-azobisisobutyronitrile (Solid content: 2.0 g) obtained in Production Example 2 of the seed particle dispersion was used as the monomer mixture to obtain a seed mixture dispersion, and 14 g of the seed particle dispersion having a volume average particle diameter of 1.01 m , Polymer particles (J) were obtained.

{Adjustment of dispersion resin composition for antiglare film and production of antiglare film}

80 parts by weight of a mixture of pentaerythritol triacrylate and pentaerythritol tetraacrylate (trade name "Aronix (registered trademark) M-305", manufactured by Toa Gosei Co., Ltd.) as an ultraviolet curable resin and 80 parts by weight of isopropanol (IPA) 120 parts by weight of a mixed solution of pentane (IPA and cyclopentanone = 5: 5), 5 parts by weight of the polymer particles prepared in Examples 1 to 6 and Comparative Examples 1 to 4, a photopolymerization initiator (2-methyl- 5 parts by weight of a dispersion resin composition (product name: "Irgacure (registered trademark) 907", manufactured by BASF (registered trademark) Japan KK) A dispersion resin composition for an antiglare film was prepared.

A polyethylene terephthalate (PET) film having a thickness of 0.2 mm as a transparent plastic film was prepared as a base film. The dispersion for an antiglare film was applied to one side of the polyethylene terephthalate film using a bar coater having a wet film thickness of 60 mu m to form a coating film. Next, the coating film was heated at 80 DEG C for 1 minute to dry the coating film. Thereafter, ultraviolet rays were irradiated to the coating film with a cumulative light quantity of 300 mJ / cm 2 with a high-pressure mercury lamp to cure the coating film to form a flash-resistant hard coat layer. As a result, each of the antiglare film (molded article) was provided with a flash-resistant hard coat film containing the polymer particles prepared in each of Examples 1 to 6 and Comparative Examples 1 to 4.

{Evaluation method of anti-glare property of antiglare film}

A method of evaluating the antiglare property of the antiglare film produced by the above method will be described. The surface of each of the antiglare films, not the coated side, is attached to a plate of ABS resin (acrylonitrile-butadiene-styrene copolymer resin) From the place 2 m away from the antiglare film, a fluorescent lamp having a luminance of 10,000 cd / cm 2 was irradiated onto the coated surface, and the antiglare property of the antiglare film was evaluated visually. The evaluation criterion of the flicker was evaluated as "good" when the contour of the reflection image of the fluorescent lamp was not clearly visible, and when the contour of the reflection image of the fluorescent lamp was clearly visible, the evaluation was evaluated as "poor".

Examples 1 to 6 and Comparative Examples 1 to 4 were prepared in the same manner as in Examples 1 to 6 and Comparative Examples 1 to 4 except that the volume average particle diameter (탆) of the seed particles used for forming the polymer particles, the monomer used in the production of the polymer particles (MMA), n-butyl methacrylate (n-BMA), styrene (St), ethylene glycol dimethacrylate (EGDMA), divinyl benzene (DVB), poly (ethylene glycol-propylene glycol) (G), monomer content (% by weight), volume average of the polymer particles (average particle size), and the amount of the polymer particles (MgKOH / g) of the hydroxyl value of the polymer particles, the evaluation results of the alcohol solvent dispersion test, and the results of measurement of the variation coefficient (CV value (%)) of the particle diameter Table 1 shows the results of evaluating the antifoggility (coating evaluation) of a coating film (antiglare film). In addition, the monomer content ratio is expressed by the weight percentage as the acrylic monomer / styrene monomer / crosslinkable monomer / hydroxyl group-containing monomer as constituent units derived from each monomer in the polymer particles.

In Table 1, observation results of some of the polymer particles relating to the evaluation results of the alcohol solvent dispersion test will be described. Figs. 1 and 2 are images showing the dispersion state of the polymer particles of Example 1 in the alcohol solvent dispersion test, and Figs. 3 and 4 show the dispersion state of the polymer particles of Comparative Example 2 in the alcohol solvent dispersion test . Fig. 1 shows a state in which the polymer particles (A) are dispersed in isopropyl alcohol, and Fig. 2 shows a state in which the polymer particles (A) are dispersed in methanol. Fig. 3 shows a state in which the polymer particles (H) are dispersed in isopropyl alcohol, and Fig. 4 shows a state in which the polymer particles (H) are dispersed in methanol. 1 to 4, the polymer particles (A) are dispersed substantially uniformly in Fig. 1 and Fig. 2, but in Fig. 3 and Fig. 4, the polymer particles are locally aggregated, I can not get the status. As shown in Fig. 3 and Fig. 4, the polymer particles (H) coagulate locally in any solvent of isopropyl alcohol and methanol. As shown in Table 1, the polymer particles (H) × ".

From the results shown in Table 1, it was found that when the polymer particles had a volume average particle diameter of 5 占 퐉 or less and a hydroxyl value of 5.0 mgKOH / g or more and 15 mgKOH / g or less, evaluation results of the alcohol solvent- It was confirmed that the evaluation results were all good.

On the other hand, when either the polymer particle diameter or the hydroxyl group deviates from the above-mentioned range, the result was that the dispersibility was poor. Particularly, in the case of polymer particles (H) having a hydroxyl value of less than 5.0 mg KOH / g, evaluation of alcohol dispersion test was low and coating was impossible. When the hydroxyl value was 5.0 mgKOH / g or more, it was considered that the dispersion was uniformly dispersed in the dispersion medium. However, when the hydroxyl value was more than 15 mg KOH / g or when the particle diameter was more than 5 m, This is considered to be due to the fact that when the hydroxyl value is excessively large, the cohesion is low and the convex portions affecting the antiglare property can not be sufficiently formed in the process of coating the film substrate and forming the coating film. On the other hand, when the volume average particle diameter of the polymer particles is more than 5 mu m, the inclination of the convex portion formed on the film substrate is accelerated, resulting in excessive scattering of external light.

In Comparative Example 2 in which the content of the constituent unit derived from the hydroxyl group-containing monomer was smaller than 3% by weight, the dispersibility was insufficient and coating was difficult. In Comparative Example 3 in which the content of the constitutional unit exceeded 15%, the dispersibility after coating and drying was excessive, and desired cohesiveness was not obtained, and the desired antistatic property was not obtained.

The present invention may be embodied in other forms without departing from the spirit or essential characteristics thereof. For this reason, the above-described embodiments are merely examples in all respects, and should not be construed as limiting. The scope of the present invention is defined by the appended claims, and is not to be construed as being limited thereto at all. Modifications and variations that fall within the equivalents of the claims are all within the scope of the present invention.

The polymer particles according to the present invention can be used as an optical member such as a light diffusion film, an optical film such as an antiglare film, a light diffusing plate, and the like by applying the polymer particle as a dispersion in a binder, It is possible to use it for various purposes including.

Claims (8)

(Meth) acryl-based monomer, a monofunctional styrene-based monomer, and a cross-linkable monomer, and a structural unit derived from a monomer having a hydroxyl group represented by the following formula (1) and / or Containing structural units,
A volume average particle diameter of 5 mu m or less,
Polymer particles having a hydroxyl value of not less than 5.0 mgKOH / g and not more than 15 mgKOH / g,
[Chemical Formula 1]

(In the formula (1), R represents H or CH ₃ , m represents a number of 0 to 50, n represents a number of 0 to 50, and m and n are not simultaneously 0)
(2)

(In the formula (2), each R independently represents H or CH ₃ , and p represents a number of 1 to 50). The method according to claim 1,
And 3 to 15% by weight of a constituent unit derived from the hydroxyl group-containing monomer. 3. The method according to claim 1 or 2,
And 3 to 35% by weight of a constituent unit derived from the crosslinkable monomer. 3. The method according to claim 1 or 2,
Wherein the monofunctional (meth) acrylic monomer has a solubility in water of not more than 0.45 wt% at 25 ° C. 3. The method according to claim 1 or 2,
Polymer particles for optical members. A method for producing polymer particles by polymerizing a vinyl monomer to produce polymer particles,
The vinyl-based monomer
(Meth) acrylic monomer, a monofunctional styrene monomer, and a cross-linkable monomer represented by the following general formula (1) and / or the general formula (2)
The hydroxyl group-containing monomer is contained in an amount of 3 to 15% by weight based on the total amount of the vinyl monomer,
Wherein the polymerization of the vinyl monomer is a seed polymerization in which the vinyl monomer is absorbed in the seed particle in an aqueous medium.
(3)

(In the formula (1), R represents H or CH ₃ , m represents a number of 0 to 50, n represents a number of 0 to 50, and m and n are not simultaneously 0)
[Chemical Formula 4]

(In the formula (2), each R independently represents H or CH ₃ , and p represents a number of 1 to 50). A dispersion liquid comprising the polymer particles of claim 1 or 2 and a binder, wherein the polymer particles are dispersed in the binder as a dispersion medium. An optical film obtained by coating the dispersion of claim 7 on a base film.

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