CN105778008B - The manufacturing method and application thereof of polymer particle, polymer particle - Google Patents

Abstract

The present invention provides the manufacturing method and application thereof of a kind of polymer particle, polymer particle, which can be evenly dispersed in dispersion liquid, can fully be agglomerated when dispersion liquid being made to volatilize.The polymer particle of the present invention, including the Component units, the Component units from monofunctional styrenic's monomer and the Component units from cross-linkable monomer that carry out the Component units of hydroxyl monomer shown in free the following general formula (1) and/or general formula (2), come from simple function (methyl) acrylic monomer, volume average particle size is 5 μm hereinafter, hydroxyl value is 5.0mgKOH/g or more and 15mgKOH/g or less.

Description

Polymer particle, method for producing polymer particle and use thereof

technical field

The present invention relates to polymer particles that can be used as raw materials for optical components such as anti-glare films and light-diffusing films, a method for producing the polymer particles, and uses thereof.

Background technique

Polymer particles are used in a wide range of fields such as spacers for liquid crystals, fillers for chromatography, and diagnostic reagents. Furthermore, 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, and an antiglare film. When such polymer particles are supplied to actual use, they are often in the form of a dispersion liquid in which polymer particles are dispersed in a solvent such as water or an organic solvent, or a paint in which a resin component such as a binder resin is further added to the dispersion liquid. to use.

Among optical components used in display devices, for example, anti-glare films are required to have a reflection preventing function. The anti-reflection function is realized by scattering external light by the fine unevenness formed by polymer particles. In particular, in order to realize a high-quality anti-reflection function, it is required to form uniform and fine unevenness on the entire anti-glare film.

When forming fine unevenness, first, polymer particles are uniformly dispersed in a dispersion liquid containing a solvent and a binder resin without agglomerating them. Then, the dispersion is applied to the surface of a base film or the like, and dried to evaporate the solvent. As a result, the polymer particles gather on the base film to form a pseudo-agglomerated state, thereby forming fine unevenness.

As such particles, Patent Document 1 discloses self-aggregating particles. In addition, as particles excellent in dispersibility, Patent Document 2 discloses a highly hydrophilic polymer particle in which a polymerizable vinyl monomer is absorbed by a seed particle containing a hydrophilic macromonomer and then polymerized. And get.

Patent Document 1: Japanese Patent Laid-Open No. 2013-231133

Patent Document 2: Japanese Unexamined Patent Publication No. 2012-062389

However, in recent years, the quality of optical films such as anti-glare films has been diversified along with the high-definition and thinning of display devices, and particles used in optical films may be required to be uniformly dispersed in alcohol-based solvents. Therefore, it is desired to develop particles that can be uniformly dispersed in alcohol solvents and sufficiently coated.

Contents of the invention

In view of this, it is an object of the present invention to provide polymer particles that can be uniformly dispersed in a dispersion and fully aggregated when the dispersion volatilizes.

In addition, another object of the present invention is to provide a method for producing the polymer particles, a dispersion liquid containing the polymer particles, and an optical film coated with the dispersion liquid.

The inventors of the present invention have achieved the present invention to solve the above-mentioned problems by polymerizing various monomers including a predetermined hydroxyl group-containing monomer so that the volume average particle diameter, hydroxyl value, and other values are within predetermined ranges.

The polymer particle in the present invention is characterized in that it contains a structural unit derived from a hydroxyl-containing monomer represented by the following general formula (1) and/or general formula (2), a monofunctional (meth)acrylic acid Constituent units derived from monomer-like monomers, monofunctional styrene-based monomers, and structural units derived from crosslinkable monomers have a volume average particle diameter of 5 μm or less, and a hydroxyl value of 5.0 mgKOH/g or more and 15 mgKOH/g or less.

Formula (1)

(In general formula (1), R represents H or CH ₃ , m represents a number from 0 to 50, n represents a number from 0 to 50, and m and n are not 0 at the same time).

Formula (2)

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

Therefore, the polymer particles described in the present invention are uniformly dispersed in the dispersion liquid, and fully aggregated when the dispersion liquid volatilizes.

The method for producing polymer particles described in the present invention is a method for producing polymer particles by polymerizing vinyl monomers to produce polymer particles, characterized in that the vinyl monomers include the following general formula ( 1) and/or the hydroxyl-containing monomers, monofunctional (meth)acrylic monomers, monofunctional styrenic monomers and crosslinking monomers represented by the general formula (2), relative to the vinyl The total amount of monomers contains 3 to 15% by weight of the hydroxyl-containing monomer, and the polymerization of the vinyl-based monomer is a seed that absorbs the vinyl-based monomer into seed particles in an aqueous medium polymerization.

Formula (1)

(In the general formula (1), R represents H or CH ₃ , m represents a number from 0 to 59, n represents a number from 0 to 50, and m and n are not 0 at the same time).

Formula (2)

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

Therefore, the polymer particles produced by the method for producing polymer particles described in the present invention are uniformly dispersed in the dispersion liquid, and are sufficiently aggregated when the dispersion liquid volatilizes.

The dispersion liquid according to the present invention is characterized in that it contains the polymer particles and a binder, and the polymer particles are dispersed as a dispersoid.

Therefore, in the dispersion liquid of the present invention, the polymer particles are uniformly dispersed, and when the dispersion liquid is applied to a coating object such as a base film and dried, the polymer particles are sufficiently aggregated.

The optical film according to the present invention is formed by applying the dispersion liquid on a base film.

Therefore, in the optical film according to the present invention, when the film is dried after coating, the polymer particles are sufficiently aggregated to form uniform and fine unevenness.

When the polymer particles, the method for producing polymer particles, the dispersion liquid, and the optical film of the present invention are used as an anti-glare film, light is scattered by the fine unevenness formed by the polymer particles, so it can prevent Excellent effects such as reflection.

Description of drawings

FIG. 1 is an image showing the dispersion state of polymer particles of Example 1 in an alcohol solvent dispersion test.

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

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

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

Detailed ways

The present invention will be described in detail below.

【Polymer particle】

The polymer particles of the present invention are used, for example, in the field of display devices as optical members such as diffusion plates, light diffusion films, and antiglare films. The polymer particle of the present invention contains a constituent unit derived from a hydroxyl-containing monomer represented by the following general formula (1) and/or the following general formula (2), and a constituent unit derived from a monofunctional (meth)acrylic monomer. unit, a structural unit derived from a monofunctional styrene-based monomer, and a structural unit derived from a vinyl-based monomer such as a crosslinkable monomer.

Formula (1)

(In the general formula (1), R represents H or CH ₃ , m represents a number from 0 to 50, n represents a number from 0 to 50, and m and n are not 0 at the same time. In addition, both m and n are preferably 1 to 30 .)

Formula (2)

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

Among the above-mentioned monomers, "Blenmer (registered trademark)" series produced by NOF Corporation can be exemplified as commercially available products of hydroxyl-containing monomers represented by the general formula (1). Furthermore, in the "Blenmer (registered trademark)" series, the present invention is preferably "Blenmer (registered trademark) 50PEP-300" (a mixture of multiple compounds represented by the general formula (1), R is CH ₃ , m is about 3.5 on average, and n is about 2.5 on average), "ブレンマー (registered trademark) 70PEP-350B" (a mixture of various compounds represented by the general formula (1), R is CH ₃ , m The average is about 5, and the average of n is about 2), "Blenmer (registered trademark) PP-1000" (a mixture of various compounds represented by the general formula (1), R is CH ₃ , m is 0, The average n is about 4 to 6), "Blenmer (registered trademark) PP-500" (a mixture of various compounds represented by the general formula (1), R is CH ₃ , m is 0, n average is about 9), "Blenmer (registered trademark) PP-800)" (a mixture of multiple compounds represented by the general formula (1), R is CH ₃ , m is 0, and n is about 13 on average), "Blenmer (registered trademark) PE-90" (a mixture of various compounds represented by the general formula (1), R is CH ₃ , m is about 2 on average, and n is 0), "Blenmer (registered trademark) )PE-200" (a mixture of multiple compounds represented by the general formula (1), R is CH ₃ , m is about 4.5 on average, and n is 0), "Blenmer (registered trademark) PE-350" (a mixture composed of a plurality of compounds represented by the general formula (1), R is CH ₃ , m is about 8 on average, and n is 0) and the like. These may be used alone or in combination of two or more.

As commercially available products of the hydroxyl group-containing monomer represented by the general formula (2), "Praccel (registered trademark) FM" series manufactured by Daicel Co., Ltd. can be exemplified. Among the series of "Praccel (registered trademark) FM", the present invention is preferably "Praccel (registered trademark) FM2D" (the compound represented by the general formula (2), R is CH ₃ , and p is 2), "Placcel (registered trademark) FM2D" (registered trademark) FM3" (the compound represented by the general formula (2), R is CH ₃ , p is 3), etc. These may be used alone or in combination of two or more.

A monofunctional (meth)acrylic monomer is a (meth)acrylic monomer having one ethylenically unsaturated group. Examples of monofunctional (meth)acrylic monomers include methyl (meth)acrylate, ethyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, ( tert-butyl methacrylate, 2-ethylhexyl (meth)acrylate, n-octyl (meth)acrylate, isononyl (meth)acrylate, lauryl (meth)acrylate, (meth) Alkyl (meth)acrylates such as stearyl acrylate and the like. In addition, in this application, "(meth)acrylate" means acrylate or methacrylate, and "(meth)acryl" means acryl or methacryl.

Among the above-mentioned monofunctional (meth)acrylic monomers, if a monofunctional (meth)acrylic monomer having a solubility in water at 25° C. of 0.45% by weight or less is used, the formula (1) represents The hydroxyl group-containing monomer is less likely to enter into the polymer particle and is more likely to exist on the surface layer, so it is preferable from the viewpoint of alcohol-based solvent dispersibility.

Specifically, n-butyl (meth)acrylate, isobutyl (meth)acrylate, tert-butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, n-butyl (meth)acrylate Octyl ester, isononyl (meth)acrylate, lauryl (meth)acrylate, octadecyl (meth)acrylate, among which n-butyl (meth)acrylate, isobutyl (meth)acrylate, tert-Butyl (meth)acrylate. In addition, from the viewpoint of alcohol solvent dispersibility, it is preferable to contain 30 to 95% by weight of the monofunctional (meth)acrylic monomer and the total amount of the monofunctional styrenic monomer. ) acrylic monomer.

In addition, in this specification, the solubility with respect to water is measured by the following method.

(Measurement method of solubility in water)

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

A monofunctional styrenic monomer is a styrenic monomer having one ethylenically unsaturated group. Examples of monofunctional styrene-based monomers include styrene, α-methylstyrene, vinyltoluene, and ethylvinylbenzene. Among them, styrene is preferable from the viewpoint of alcohol solvent dispersibility and polymerization reactivity.

The crosslinkable monomer is a polyfunctional monomer having a plurality of ethylenically unsaturated groups, and functions as a crosslinking agent. Examples of crosslinkable monomers include trimethylolpropane triacrylate, ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, triethylene glycol dimethacrylate, decaethylene dimethacrylate, Alcohol dimethacrylate, pentaethylene glycol dimethacrylate, 50/100 ethylene glycol dimethacrylate (pentacontahectaethylene glycoldimethacrylate), 1,3-butanediol dimethacrylate, methacrylic acid Allyl ester, trimethylolpropane trimethacrylate, pentaerythritol tetraacrylate and other polyfunctional (meth)acrylate monomers, divinylbenzene, divinylnaphthalene, N,N-divinylaniline , divinyl ether, divinyl sulfide, divinyl sulfonic acid and other divinyl monomers.

The polymer particles of the present invention having the above-mentioned monomers as constituent units preferably contain 3 to 15% by weight of a hydroxyl group-containing monomer and 3 to 35% by weight of a crosslinkable monomer as constituent units. When the hydroxyl group-containing monomer is less than 3% by weight, the dispersibility in hydrophilic organic solvents such as alcohol solvents is insufficient, and the operability of coating may be reduced. When it is higher than 15% by weight, the above-mentioned dispersibility becomes excessive, The desired aggregation state cannot be obtained after coating and drying. When the cross-linking monomer is less than 3% by weight, the degree of cross-linking of the resin particles becomes low. As a result, when the resin particles are dispersed in the binder and applied as a dispersion liquid, the resin particles may swell and cause the viscosity of the dispersion liquid to increase. increase, resulting in reduced coating operability. In addition, when the crosslinkable monomer is more than 35% by weight, the effect does not increase in proportion to the amount of the crosslinkable monomer used, which may increase the production cost.

In addition, the polymer particles of the present invention are synthesized to have a volume average particle diameter of 5 μm or less. Furthermore, the volume average particle diameter can be measured by the Coulter counter method, for example.

When the polymer particles have a volume average particle diameter of 5 μm or less, they are aggregated in an appropriate number to form preferable convex portions when applied and dried to form a film. Moreover, more preferable convex parts can be formed by making a particle diameter into 1 micrometer or more and 5 micrometers or less.

In addition, when the volume average particle diameter of the polymer particles is greater than 5 μm, for example, when used as an anti-glare film on the surface of a display device, the protrusions formed by aggregation of the polymer particles are steep, resulting in excessive scattering of external light, and the display surface may be damaged. will become whitish. And when the volume average particle diameter of the polymer particles is less than 1 μm, for example, when used as an anti-glare film on the surface of a display device, the protrusions formed due to the aggregation of the polymer particles become flat, and the external light cannot be sufficiently scattered, which may not be able to suppress the glare. Reflection on the display surface.

The particle size variation coefficient (CV) of the polymer particles is preferably 15% or less. Accordingly, when the polymer particles are used in optical components such as an anti-glare film and a light-diffusing film, optical properties such as anti-glare and light-diffusing properties of the optical component can be improved.

In addition, the polymer particle of the present invention is synthesized such that its hydroxyl value is not less than 5.0 mgKOH/g and not more than 15 mgKOH/g. In addition, the hydroxyl value can be measured, for example, by the hydroxyl value quantitative analysis method (JIS K 0070).

When the polymer particle has a hydroxyl value of 5.0 to 15 mgKOH/g, when dispersed in a hydrophilic organic solvent such as an alcohol solvent together with a binder, it can be appropriately dispersed in a hydrophilic organic solvent. That is, the polymer particles of the present invention can be uniformly dispersed without aggregation, and when applied and dried, excessive dispersion does not cause poor aggregation.

By uniformly dispersing in a hydrophilic organic solvent, when forming an optical film such as an anti-glare film, a uniform thin film without spots can be formed. In addition, by preventing poor aggregation, fine unevenness can be formed, and external light such as light emitted by an external fluorescent lamp can be scattered to prevent reflection and improve anti-glare properties.

Furthermore, when the polymer particles have a volume average particle diameter of 5 μm or less, they are aggregated in an appropriate number to form preferable convex portions when they are processed into a film by coating and drying.

And, when the volume average particle diameter of the polymer particles is greater than 5 μm, for example, when used as an anti-glare film on the surface of a display device, the protrusions formed by the aggregation of the polymer particles become steep, so the external light is excessively scattered, and the display surface May become whitish.

Quantitative and qualitative determination of the constituent units derived from each monomer in the polymer particles can be confirmed by analytical methods such as gas chromatography, liquid chromatography, infrared spectrophotometry (IR), and nuclear magnetic resonance (NMR). In addition, the weight ratio of each monomer in the monomer mixture is substantially the same as the weight ratio of the constituent units derived from each monomer in the polymer particles.

【Manufacturing method of polymer particles】

Next, the method for producing the polymer particles of the present invention will be described. The polymer particles of the present invention are preferably produced by seed polymerization. Manufactured by seed polymerization, the variation in particle size can be suppressed. When used as an optical film such as an anti-glare film or a light-diffusing film, optical properties such as anti-glare properties and light-diffusing properties can be improved by suppressing variation in particle size. The method for producing polymer particles of the present invention is a method for producing polymer particles by polymerizing a vinyl-based monomer comprising the polymer particles obtained by the general formula (1) and/or the general formula (1) and/or The hydroxyl-containing monomer represented by formula (2), monofunctional (meth)acrylic monomer, monofunctional styrenic monomer and crosslinking monomer, the polymerization of the vinyl monomer is in aqueous medium Seed polymerization in which the above-mentioned vinyl monomer is absorbed in seed particles.

Seed polymerization is a method of polymerizing seed (seed) particles made of polymers obtained by polymerizing monomers such as vinyl monomers. Specifically, seed particles are produced and other monomers are absorbed in an aqueous medium. A method in which the obtained seed particles are produced and the monomer absorbed into the seed particles is polymerized.

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

As the monomer for seed polymerization, vinyl monomers such as monofunctional (meth)acrylic monomers, monofunctional styrene monomers, monofunctional (meth)acrylic monomers, and monofunctional benzene monomers can be exemplified. Mixtures of vinyl monomers, etc.

Examples of the aqueous medium include lower alcohols (alcohols having 5 or less carbon atoms) such as water, methanol, and ethanol, mixtures of water and lower alcohols, and the like.

Any of anionic surfactants, cationic surfactants, nonionic surfactants, and amphoteric surfactants can be used as the surfactant.

Examples of the anionic surfactant include fatty acid soaps such as sodium oleate and potassium castor oil soap, alkyl sulfate ester salts such as sodium lauryl sulfate and ammonium lauryl sulfate, dodecylbenzenesulfonic acid, etc. Sodium and other alkylbenzene sulfonates, alkyl naphthalene sulfonates, alkyl sulfonates, di(2-ethylhexyl) sodium sulfosuccinate, dioctyl sodium sulfosuccinate and other dialkylsulfosuccinates Succinate, alkenyl succinate (dicalcium salt), alkyl phosphate ester salt, naphthalenesulfonic acid formaldehyde condensate, polyoxyethylene alkylphenyl ether sulfate salt, polyoxyethylene lauryl ether sulfate sodium Such as polyoxyethylene alkyl ether sulfate, polyoxyethylene alkyl sulfate, etc.

Examples of the nonionic surfactant include polyoxyethylene alkyl ethers such as polyoxyethylene tridecyl ether, polyoxyethylene alkylphenyl ethers such as polyoxyethylene octylphenyl ether, polyoxyethylene benzene, etc. Vinyl phenyl ethers, polyoxyalkylene alkyl ethers such as polyoxyalkylene tridecyl esters having 3 or more alkenyl carbon atoms, polyoxyethylene fatty acid esters, sorbitan fatty acid esters, polyoxyl monolaurate Polyoxyethylene sorbitan fatty acid esters such as ethylene sorbitan, polyoxyethylene alkylamines, glycerin fatty acid esters, ethylene oxide-propylene oxide block copolymers, and the like.

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

Examples of the above-mentioned amphoteric surfactant include lauryl dimethylamine oxide, phosphoric acid ester-based surfactant, phosphite-based surfactant, and the like. The above 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 relative to 100 parts by weight of the monomer for seed polymerization. When the usage-amount of surfactant is less than the said range, polymerization stability may fall. In addition, when the surfactant is used above the above range, the cost of the surfactant rises.

The added emulsion is produced by a known method. For example, monomers and surfactants are added to an aqueous medium, and dispersed with a fine emulsification device such as a homogenizer, an ultrasonic processor, or a nanomicronizer (nanomizer), to obtain an emulsion. As the above-mentioned aqueous medium, water or a mixture of water and an organic solvent (such as a lower alcohol (alcohol having 5 or less carbon atoms)) can be used.

Seed particles can be directly added to the emulsion, or can be added to the emulsion in the form of being dispersed in an aqueous medium. When the seed particles for seed polymerization are added to the emulsion, the monomer for seed polymerization is absorbed by the seed particles. This absorption can usually be carried out by stirring the emulsion at room temperature (about 20° C.) for 1 to 12 hours. In addition, in order to promote the absorption of the monomer for seed polymerization into the seed particles, the emulsion can be heated to about 30-50°C.

The seed particles swell by absorbing monomers. The mixing ratio of the absorbed monomer for seed polymerization and the seed particles is preferably within the range of 5 to 300 parts by weight, more preferably within the range of 100 to 250 parts by weight, based on 1 part by weight of the seed particles. When the mixing ratio of the absorbed monomer for seed polymerization is less than the above-mentioned range, the increase in particle size due to polymerization becomes small, and the production efficiency decreases. On the other hand, when the mixing ratio of the absorbed monomer for seed polymerization is higher than the above-mentioned range, the monomer for seed polymerization cannot be completely absorbed by the seed particles, and suspension polymerization is carried out alone in an aqueous medium, which may produce particles with an abnormally small particle size. polymer particles. In addition, whether or not the absorption of the monomer for seed polymerization into the seed particle is completed can be judged by confirming the expansion of the particle diameter by optical microscope observation.

Therefore, the polymer particles of the present invention can be obtained by polymerizing the monomers absorbed by the seed particles. In addition, the step of polymerizing the monomer absorbed by the seed particles may be repeated multiple times to obtain the polymer particles of the present invention.

To the polymerized seed polymerization monomer, a polymerization initiator may be added as needed. The polymerization initiator may be mixed with the monomer to be polymerized, and the resulting mixture may be dispersed in an aqueous medium, or both the polymerization initiator and the monomer for seed polymerization to be polymerized may be separately dispersed in an aqueous medium and mixed. . The droplet size of the monomer for seed polymerization present in the obtained emulsion is preferably smaller than that of the seed particles, because the monomer can then be effectively absorbed by the seed particles.

The polymerization initiator is not particularly limited, and examples include benzoyl peroxide, lauroyl peroxide, o-chlorobenzoyl peroxide, o-methoxybenzoyl peroxide, 3,5,5 -Organic peroxides such as trimethylhexanoyl peroxide, (2-ethylhexanoic acid) tert-butyl peroxide, di-tert-butyl peroxide, 2,2'-azobisisobutyronitrile, 2,2'-Azobis(2,4-Dimethylvaleronitrile), 2,2'-Azobis(2,3-Dimethylbutyronitrile), 2,2'-Azobis(2 -methylbutyronitrile), 2,2'-azobis(2,3,3-trimethylbutyronitrile), 2,2'-azobis(2-isopropylbutyronitrile), 1,1 '-Azobis(cyclohexane-1-carbonitrile), 2,2'-Azobis(4-methoxy-2,4-dimethylvaleronitrile), (2-carbamoyl azo) Isobutyronitrile ((2-Calvamoil Aze) Isobuchironitril), 4,4'-Azobis(4-cyanovaleric acid), Dimethyl-2,2'-Azobisisobutyrate, etc. Azo compounds, etc. It is preferable that a polymerization initiator exists in the range of 0.1-1.0 weight part with respect to 100 weight part of monomers.

The polymerization temperature of the above-mentioned seed polymerization can be appropriately determined according to the kind of the monomer for seed polymerization to be polymerized and the kind of the polymerization initiator used if necessary. The polymerization temperature of the seed polymerization is specifically preferably 25 to 110°C, more preferably 50 to 100°C. In addition, the polymerization time of the seed polymerization is preferably 1 to 12 hours. The polymerization reaction of the seed polymerization can be carried out under an atmosphere of an inert gas (for example, nitrogen) which is inert to the polymerization. In addition, the polymerization reaction of the seed polymerization is preferably carried out by raising the temperature after the monomers to be polymerized and, if necessary, the polymerization initiator used are completely absorbed by the seed particles.

In the above seed polymerization, in order to improve the dispersion stability of polymer particles, a polymer dispersion stabilizer can be added to the polymerization reaction system. Examples of the polymer dispersion stabilizer include polyvinyl alcohol, polycarboxylic acid, celluloses (hydroxyethyl cellulose, carboxymethyl cellulose, etc.), polyvinylpyrrolidone, and the like. In addition, the above-mentioned polymer dispersion stabilizer and inorganic water-soluble polymer compounds such as sodium tripolyphosphate may be used in combination. Among these polymer dispersion stabilizers, polyvinyl alcohol and polyvinylpyrrolidone are preferable. The added amount of the polymer dispersion stabilizer is preferably within a range of 1 to 10 parts by weight relative to 100 parts by weight of the monomer for seed polymerization.

In addition, in order to suppress the generation of emulsified particles (polymer particles with too small particle size) in the aqueous medium in the above-mentioned polymerization reaction, nitrites such as sodium nitrite, sulfites, and hydroquinone can be added to the aqueous medium. Water-soluble polymerization inhibitors such as ascorbic acid, water-based vitamin B, citric acid, and polyphenol. It is preferable that the addition amount of the said polymerization inhibitor exists in the range of 0.02-0.2 weight part with respect to 100 weight part of vinylic monomers.

The polymer particles obtained by polymerizing the monomer for seed polymerization absorbed by the seed particles in this way are centrifuged to remove the aqueous medium if necessary after the completion of the polymerization, washed with water and/or a solvent, dried and separated. The method for separating the polymer particles obtained by seed polymerization from the aqueous medium is not particularly limited, and examples include a spray drying method represented by a spray dryer, and a method of drying by attaching to a heated drum represented by a drum dryer. , Freeze-drying and the like.

Furthermore, the polymerization method for polymerizing the monomer for seed polymerization to obtain seed particles is not particularly limited, and dispersion polymerization, emulsion polymerization, soap-free emulsion polymerization, seed polymerization, suspension polymerization, etc. can be used. In order to obtain polymer particles with approximately uniform particle diameters by seed polymerization, it is necessary to use seed particles with approximately uniform particle diameters from the beginning, and to grow these seed particles to approximately the same size. Seed particles with approximately uniform particle diameters as raw materials can be used to polymerize monofunctional (meth)acrylic monomers, monofunctional styrenes, etc. Monomers and other vinyl monomers to manufacture. Therefore, as a polymerization method for obtaining seed particles, emulsion polymerization, soap-free emulsion polymerization, seed polymerization, and dispersion polymerization are preferable.

In the polymerization to obtain seed particles, a polymerization initiator is also used as necessary. As the polymerization initiator, persulfates such as calcium persulfate, ammonium persulfate, sodium persulfate, benzoyl peroxide, lauroyl peroxide, o-chlorobenzoyl peroxide, o- Methoxybenzoyl peroxide, 3,5,5-trimethylhexanoyl peroxide, (2-ethylhexanoic acid) tert-butyl peroxide, di-tert-butyl peroxide and other organic peroxides , 2,2'-azobisisobutyronitrile, 1,1'-azobiscyclohexanenitrile, 2,2'-azobis(2,4-dimethylvaleronitrile) and other azo compounds. It is preferable that the usage-amount of the said polymerization initiator exists in the range of 0.1-3 weight part with respect to 100 weight part of monomers for seed polymerization used for obtaining a seed particle. The weight-average molecular weight of the obtained seed particles can be adjusted by increasing or decreasing the amount of the polymerization initiator used.

In the polymerization to obtain seed particles, a molecular weight regulator may be used in order to adjust the weight average molecular weight of the obtained seed particles. As the molecular weight regulator, mercaptans such as n-octyl mercaptan and t-dodecyl mercaptan, terpenes such as α-methylstyrene dimer, γ-terpinene, and dipentene can be used. , Halogenated hydrocarbons such as chloroform, carbon tetrachloride, etc. The weight average molecular weight of the obtained seed particle can be adjusted by increasing or decreasing the usage-amount of the said molecular weight modifier.

The polymer particles of the present invention are suitable for use in optical components of optical films such as anti-glare films and light-diffusing films, and are also suitable for use as dispersions mixed with binders.

【Optical film and its manufacturing method】

The optical film of the present invention is formed by applying the dispersion liquid of the present invention on a substrate film, the dispersion liquid of the present invention includes polymer particles dispersed as a dispersoid, and a binder.

Next, a method for producing an optical member using the polymer particles of the present invention will be described. Here, an example in which an optical film such as an antiglare film is produced as an optical member will be described. In the production of the optical film of the present invention, the dispersion liquid of the present invention obtained by dispersing a dispersoid such as polymer particles of the present invention in a dispersion medium such as a binder is used. Specifically, a coating dispersion obtained by dispersing a dispersoid such as polymer particles in a dispersion medium such as a binder is applied on a base film and dried to form a coating film on the base film. .

The binder is not particularly limited as long as it can be used in the field according to required properties such as transparency, polymer particle dispersibility, light resistance, moisture resistance, and heat resistance. Examples of binders include (meth)acrylic resins, (meth)acrylic-urethane resins, polyurethane resins, polyvinyl chloride resins, polyvinylidene chloride resins, melamine resins, styrene resins, Resin, alkyd resin, phenol resin, epoxy resin, polyester resin, silicone resin such as alkylpolysiloxane resin, (meth)acrylic-silicone resin, silicone-alcohol Binder resins such as modified silicone resins such as acid resins, silicone-polyurethane resins, silicone-polyester resins, and fluorinated resins such as polyvinylidene fluoride and fluoroolefin vinyl ether polymers.

The binder resin is preferably a curable resin capable of forming a cross-linked structure through a cross-linking reaction from the viewpoint of improving the durability of the coating dispersion. Curable resins can be cured under various curing conditions. Curable resins are classified into ionizing radiation curable resins such as ultraviolet curable resins and electron beam curable resins, thermosetting resins, and temperature (temperature) curable resins, depending on the type of curing.

Examples of the thermosetting resin include thermosetting polyurethane-based resins composed of acrylic polyols and isocyanate prepolymers, phenol resins, urea melamine resins, epoxy resins, unsaturated polyester resins, silicone resins, and the like.

Examples of ionizing radiation-curable resins include polyfunctional (meth)acrylate resins such as polyol polyfunctional (meth)acrylates, which are synthesized from diisocyanates, polyols, and hydroxyl-containing (meth)acrylates. Multifunctional urethane acrylate resin, etc.

As the ionizing radiation curable resin, in addition to these, polyether resins, polyester resins, epoxy resins, alkyd resins, spiroacetal (spiroacetal) resins, polybutadiene resins, polythiol polyene resin, etc.

As the binder resin, thermoplastic resins may be used in addition to the curable resins described above. Examples of thermoplastic resins include cellulose derivatives such as acetylcellulose, nitrocellulose, acetylbutylcellulose, ethylcellulose, methylcellulose, homopolymers and copolymers of vinyl acetate, Vinyl resins such as homopolymers and copolymers of vinyl chloride, homopolymers and copolymers of vinylidene chloride, acetal resins such as polyvinyl formal and polyvinyl butyral, homopolymers of acrylates (meth)acrylic resins such as copolymers, methacrylate homopolymers and copolymers, polystyrene resins, polyamide resins, linear polyester resins, polycarbonate resins, etc.

In addition, as the binder, rubber-based binders such as synthetic rubber and natural rubber, inorganic binders, and the like can be used in addition to the above-mentioned binder resins. Examples of the rubber-based binder resin include ethylene-propylene copolymer rubber, polybutadiene rubber, styrene-butadiene rubber, acrylonitrile-butadiene rubber, and the like.

The above-mentioned dispersion liquid for coating may further contain an organic solvent. When coating the above-mentioned dispersion liquid for coating on a base material such as a base film described later, there are no particular limitations as long as the coating dispersion liquid is easily applied to the base material by containing the above-mentioned organic solvent. As the above-mentioned organic solvent, aromatic solvents such as toluene and xylene, alcohol solvents such as methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, propylene glycol monomethyl ether, ethyl acetate, acetic acid, etc., can be used. Butyl ester and other ester solvents, acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclopentanone, cyclohexanone and other ketone solvents, 2-methoxyethanol, 2-ethoxyethanol, 2-butoxyethanol , ethylene glycol dimethyl ether, ethylene glycol diethyl ether, diethylene glycol dimethyl ether, propylene glycol methyl ether and other glycol ethers, 2-methoxyethyl acetate, 2-ethoxy Ethyl acetate (Cellosolve acetate), 2-butoxyethyl acetate, propylene glycol methyl ether acetate and other glycol ether esters, chloroform, dichloromethane, chloroform, tetrachloromethane, etc. Chlorinated solvents, tetrahydrofuran, diethyl ether, 1,4-dioxane, 1,3-dioxolane and other ether solvents, N-methylpyrrolidone, dimethylformamide, dimethylsulfoxide, Amide solvents such as dimethylacetamide, etc. These organic solvents may be used alone or in combination of two or more. Among them, alcohol solvents having 5 or less carbon atoms are preferable, and methanol, ethanol, and propanol are more preferable in terms of uniform dispersibility of polymer particles in the dispersion liquid and cohesion after drying.

The base film is preferably a transparent base. As a transparent base film, polyester-based polymers such as polyethylene terephthalate (PET) and polyethylene naphthalate, diacetyl cellulose, triacetyl cellulose, etc., can be exemplified. Films of polymers such as cellulosic polymers such as (TAC), polycarbonate polymers, and (meth)acrylic polymers such as polymethyl methacrylates. In addition, as a transparent base film, styrene-based polymers such as polystyrene and acrylonitrile-styrene copolymers, polyethylene, polypropylene, polyolefins containing a ring or a norbornene structure, ethylene, etc., can also be exemplified. - Films of polymers such as olefin-based polymers such as propylene copolymers, vinyl chloride-based polymers, and amide-based polymers such as nylon and aramid. In addition, examples of transparent substrate films include imide polymers, sulfone polymers, polyethersulfone polymers, polyether ether ketone polymers, polyphenylene sulfide polymers, vinyl alcohol-based polymers, vinylidene chloride-based polymers, vinyl butyral-based polymers, arylate-based polymers, polyoxymethylene-based polymers, epoxy-based polymers, and polymer films of mixtures of these polymers. As the base film, it is particularly preferable to use a base film with little birefringence. In addition, these films are further provided with an easy-adhesive layer such as (meth)acrylic resin, copolyester resin, polyurethane resin, styrene-maleic acid graft polyester resin, acrylic graft polyester resin, etc. A film can also be used as the above-mentioned base film.

The thickness of the base film can be appropriately determined, but generally it is within the range of 10 to 500 μm, preferably 20 to 300 μm, and more preferably 30 to 200 μm from the viewpoint of strength, handleability, etc., and thin layer properties. . In addition, additives such as ultraviolet absorbers, infrared absorbers, antistatic agents, refractive index modifiers, and reinforcing agents may be added to the base film.

As a method of coating the dispersion liquid for coating on the substrate film, bar coating method (bar coating method), blade coating method, spin coating method, reverse coating method (riber coating method) and die coating method are exemplified. Known coating methods such as (diacoating), spray coating, roll coating, gravure coating, micro gravure coating, lip die coating, air knife coating, and dip coating.

The optical film of the present invention constituted in this way is obtained by applying a coating dispersion liquid containing the polymer particles of the present invention having excellent dispersion stability on a base film, and thus formed by the coating. In the entire coating film, stable and uniform optical properties such as light diffusing property and anti-glare property can be obtained. Therefore, the optical film of the present invention has high quality stability.

【Example】

Hereinafter, although an Example and a comparative example demonstrate this invention, this invention is not limited to these. First, with respect to the following examples and comparative examples, the measurement method of the volume average particle diameter and particle diameter variation coefficient of polymer particles, the volume average particle diameter measurement method of seed particles used in the manufacture of polymer particles, and the measurement method of polymer particles are described. Hydroxyl value determination method and alcohol solvent dispersion test.

{Measuring method of volume average particle diameter and particle diameter variation coefficient of polymer particles}

The volume average particle diameter of the polymer particles was measured with a Coulter Counter III (measurement device manufactured by Beckman Coulter, Inc.). The measurement was carried out using an aperture (Aperture) calibrated in the Counter TM3 User's Guide issued by Beckman Coulter, Inc.

In addition, the pore diameter used for the measurement is appropriately selected according to the size of the particle to be measured. When choosing to have an aperture of 50 μm, 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 was dispersed with a touch mixer ("TOUCHMIXER MT-31" manufactured by Yamato Science Co., Ltd.) and an ultrasonic cleaner ("ULTRASONIC CLEANER VS-150" manufactured by VELVO CLEANER CO., LTD.) It is used as a dispersion in a 0.1% by weight aqueous solution of nonionic surfactant. Stir slowly during the measurement to avoid introducing air bubbles into the beaker, and the measurement ends when 100,000 polymer particles are measured. The volume average particle diameter of the polymer particles is the arithmetic mean in the particle size distribution based on the volume of 100,000 particles.

The particle size variation coefficient (CV value) of the polymer particles is calculated by the following mathematical formula.

The particle diameter variation coefficient of polymer particle=(the volume reference particle size distribution standard deviation of polymer particle ÷ the volume average particle diameter of polymer particle)×100

{Measuring method of volume average particle diameter of seed particles used in the production of polymer particles}

The volume average particle diameter of the seed particles used in the production of polymer particles was measured by a laser diffraction/scattering particle size distribution analyzer ("LS 13 320" manufactured by Beckman Coulter Co., Ltd.) Sunpur Mojiul) is carried out.

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

The pump circulation is carried out in the universal liquid sample module, and the above-mentioned seed particles are dispersed, and the ultrasonic unit (ULM ULTRASONIC MODULE) is activated, and the volume average particle diameter (volume-based particle size distribution) of the seed particles is calculated. Arithmetic mean diameter in ). The measurement conditions are as follows.

medium = water

Medium refractive index = 1.333

Solid refractive index = seed particle refractive index (1.495)

Relative concentration of PIDS: around 40-55%

{Measurement method of hydroxyl value of polymer particles}

The measurement of the hydroxyl value of the polymer particles was carried out in accordance with the quantitative analysis method of the hydroxyl value (JIS K 0070-1992). Specifically, the steps are as follows.

＜Acid value measurement method for the determination of hydroxyl value "JIS K 0070"＞

Add 2g of sample and 20mL of pyridine solvent into a 200mL flat-bottomed beaker, stir at room temperature for 1 hour to disperse, add 3 drops of phenolphthalein reagent, and titrate with 0.5mol/L potassium hydroxide ethanol solution, when the color becomes purple. end. Carry out a blank test in the same way, and calculate the acid value according to the following formula. The measurement was carried out twice, and the average value was used as the acid value.

＜Acid Value Calculation Formula＞

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

in

S: Sampling sample mass (g)

V0: the amount of 0.1mol/L potassium hydroxide ethanol solution required in the blank test (mL).......Blank titration (mL)

V1: The amount of 0.1mol/L potassium hydroxide ethanol solution required in this test (mL).......sample titration (mL)

f: factor of 0.1mol/L potassium hydroxide ethanol solution......1.0

<Analytical method steps>

Add 2g of sample and 3mL of acetylation reagent into a 200mL flat-bottomed beaker, stir to dissolve, then add 20mL of pyridine solution, stir for 10 minutes, and react in an oil bath at 110°C for 1 hour. Thereafter, the mixture was stirred with a shaker for 10 minutes, left to cool, and 1 mL of distilled water was added thereto, followed by reaction in a 105° C. oil bath for 10 minutes. Then add 3 drops of phenolphthalein reagent, and titrate with 0.5mol/L potassium hydroxide ethanol solution, when the color turns purple as the end point. Carry out a blank test in the same way, and calculate the hydroxyl value according to the following formula. The determination was carried out twice, and the average value was taken as the hydroxyl value.

＜Hydroxyl Value Calculation Formula＞

Hydroxyl value (mgKOH/g)=(V0-V1)×f×0.5×56.11÷S+acid value

in

S: Sampling sample mass (g)

V0: the amount of 0.5mol/L potassium hydroxide ethanol solution required in the blank test (mL).......Blank titration (mL)

V1: The amount of 0.5mol/L potassium hydroxide ethanol solution required in this test (mL).......sample titration (mL)

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

{Alcohol solvent dispersion test}

Alcohol solvent dispersion test, weigh 0.1g of particles and 5g of methanol or isopropanol as alcohol solvent in a plastic ointment jar with a capacity of 10mL, and use a stirring defoamer (あわとり先太郎 (registered trademark) AR-100: Shinky Co., Ltd.) was stirred for 3 minutes. After the stirring was completed, 1 drop of the dispersion liquid was dropped on the glass plate with a glass pipette, and a cover glass was covered from the top. Then, the dispersion state was observed with a digital microscope VHX (manufactured by Keyence Co., Ltd.), and an evaluation test was implemented. From the observation results, it was judged as "⊚" when it was dispersible in both methanol and isopropanol, it was judged as "◯" when it was dispersed in either one, and it was judged as "×" when it was not dispersible in both.

{Manufacturing example 1 of seed particles}

In a separatory bottle equipped with a stirrer, a thermometer and a reflux condenser, add 3000 g of water as an aqueous medium, 500 g of methyl methacrylate as a monofunctional (meth)acrylic monomer, and n-octyl as a molecular weight modifier. 5 g of base mercaptan, and stirring the contents in the liquid separation bottle, the inside of the liquid separation bottle was replaced with nitrogen, and the inner temperature of the liquid separation bottle was raised to 70°C. Next, the inner temperature of the separating bottle was kept at 70° C., and 2.5 g of potassium persulfate as a polymerization initiator was added to the content of the separating bottle, followed by a polymerization reaction for 12 hours to obtain an emulsion. The obtained emulsion contained 14% by weight of solids (polymethyl methacrylate particles), and the solids were spherical particles (seed particles) with a volume average particle diameter of 0.45 μm and a weight average molecular weight of 15,000. The emulsion containing the spherical particles was used as a seed particle dispersion and used in Examples and Comparative Examples of polymer particles described later.

{Manufacturing example 2 of seed particles}

In a separatory bottle equipped with a stirrer, a thermometer, and a reflux condenser, 600 g of water as an aqueous medium, 70 g of the emulsion obtained in Production Example 1 of seed particles, and formazan as a monofunctional (meth)acrylic monomer were added. 100 g of methyl methacrylate and 1.0 g of n-octyl mercaptan as a molecular weight modifier, while agitating the contents of the liquid separation bottle with a stirrer, the space in the liquid separation bottle was replaced with nitrogen, and the internal temperature of the liquid separation bottle was raised. to 70°C. Next, after adding 0.5 g of potassium persulfate as a polymerization initiator while keeping the inner temperature of the separating bottle at 70° C., a polymerization reaction was carried out over 8 hours while keeping the inner temperature of the separating bottle at 70° C. Thus a seed particle dispersion is obtained. The obtained seed particle dispersion contained 14% by weight of solid matter composed of spherical particles (seed particles) having a volume average particle diameter of 1.01 μm.

{Example 1: Production example of polymer particles}

In a 5L reactor equipped with a stirrer and a thermometer, add styrene 300g as a monofunctional styrenic monomer, n-butyl methacrylate as a monofunctional (meth)acrylic monomer (the solubility to water is in 25° C. (0.04% by weight) 350 g, 300 g of ethylene glycol dimethacrylate as a crosslinkable monomer, poly(ethylene glycol-propylene glycol) as a hydroxyl group-containing monomer represented by the general formula (1) ) monomethacrylate (trade name "Blenmer (registered trademark) 50PEP-300", manufactured by NOF Corporation, a mixture of various compounds represented by the general formula (1), R=CH ₃ , The average of m is 3.5, and the average of n is 2.5) 50 g and 8 g of 2,2'-azobisisobutyronitrile as a polymerization initiator are dissolved in each other to obtain a monomer mixture. Dissolve 10 g of polyoxyethylene octylphenol ether as a nonionic surfactant in 990 g of ion-exchanged water to obtain 1,000 g of a surfactant aqueous solution, mix the obtained monomer mixture with the surfactant aqueous solution, and put it into a high-speed emulsification dispersion Machine (trade name "Homo Mikuser MARK II 2.5 type", manufactured by Primix Co., Ltd.) was processed at 10,000 rpm for 10 minutes to obtain an emulsion. To this emulsion was added 24 g (3.4 g of solid matter) of the seed particle dispersion having a volume average particle diameter of 0.45 μm obtained in Production Example 1 of the above seed particle, and stirred at 30° C. for 3 hours to obtain a dispersion. To this dispersion, 2000 g of an aqueous solution of 4% by weight of polyvinyl alcohol (manufactured by Nippon Synthetic Chemical Industry Co., Ltd., trade name "Gosenol (registered trademark) GH-17") as a polymer dispersion stabilizer and 2000 g of a polymerization inhibitor 0.6 g of sodium nitrite was then stirred at 70° C. for 5 hours, and then stirred at 105° C. for 2.5 hours to conduct a polymerization reaction. The polymerized dispersion liquid was dehydrated with a pressure filter, washed with warm water, and vacuum-dried at 70° C. for 24 hours to obtain polymer particles A composed of a crosslinked (meth)acrylic acid-styrene copolymer resin.

{Example 2: Production example of polymer particles}

80 g of styrene as a monofunctional styrene-based monomer, 700 g of methyl methacrylate (soluble in water at 25°C: 1.72% by weight) as a monofunctional (meth)acrylic monomer, and 700 g of a crosslinking property 120 g of divinylbenzene as a monomer, poly(ethylene glycol-propylene glycol) monomethacrylate (trade name "Blenmer (registered trademark 50PEP-300)" as a hydroxyl-containing monomer represented by the general formula (1) , NOF Co., Ltd.) 100 g, 2,2'-azobisisobutyronitrile 8 g as a polymerization initiator are mutually dissolved to obtain a monomer mixture, and the volume average particle diameter obtained in the above-mentioned seed particle production example 1 is Polymer particles B were obtained in the same manner as in Example 1 except that 80 g (11.2 g of solid matter) of a 0.45 μm seed particle dispersion was used as a seed particle dispersion.

{Example 3: Production 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 crosslinkable monomer, and 100 g of poly(ethylene glycol-propylene glycol) monomethacrylate (trade name "Blenmer (registered trademark 50PEP-300", manufactured by NOF Corporation)) of a hydroxyl-containing monomer represented by the formula (1) was used as a polymerization initiator The 2,2'-azobisisobutyronitrile 8g of the agent is mutually dissolved to obtain a monomer mixture, and the volume average particle diameter obtained in the above-mentioned seed particle production example 1 is 80g of the seed particle dispersion (solid matter 11.2 μm) g) Except having used the seed particle dispersion, it carried out similarly to Example 1, and obtained the polymer particle 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 Lactone-modified hydroxyethyl methacrylate of a hydroxyl-containing monomer shown in the general formula (2) (trade name "Praccel (registered trademark) FM2D", manufactured by Daicel Chemical Co., Ltd., the general formula (2) 50 g of P=2) and 8 g of 2,2'-azobisisobutyronitrile as a polymerization initiator are mutually dissolved to obtain a monomer mixture, and the volume average particle diameter obtained in the above-mentioned seed particle production example 1 is 0.45 Polymer particles D were obtained in the same manner as in Example 1 except that 80 g (11.2 g of solid matter) of a seed particle dispersion of μm was used as a seed particle dispersion.

{Example 5: Production example of polymer particles}

80 g of styrene as a styrene-based monomer, 700 g of n-butyl methacrylate as a (meth)acrylic monomer, 120 g of divinylbenzene as a crosslinkable monomer, and the formula (1 ) poly(ethylene glycol-propylene glycol) monomethacrylate (trade name "Blenmer (registered trademark) 50PEP-300", produced by NOF Corporation) represented by the hydroxyl group-containing monomer, obtained by the general formula (1) A mixture of various compounds shown in , R ₁ =CH ₃ , R ₂ =C ₂ H ₅ , R ₃ =C ₃ H ₆ , R ₄ =H, m average is 3.5, n average is 2.5) 100g, As a polymerization initiator, 2,2'-azobisisobutyronitrile 8g dissolves each other to obtain a monomer mixture, and the volume average particle diameter obtained in the above-mentioned seed particle production example 1 is 80 g of seed particle dispersion of 0.45 μm ( Solid matter 11.2 g) was used as a seed particle dispersion, and it carried out similarly to Example 1, and obtained the polymer particle E.

{Example 6: Production example 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 50 g of poly(ethylene glycol-propylene glycol) monomethacrylate (trade name "Blenmer (registered trademark) 50PEP-300", manufactured by NOF Corporation) of a hydroxyl-containing monomer represented by the formula (1) was used as a polymerization initiator The 2,2'-azobisisobutyronitrile 8g of the agent is mutually dissolved to obtain a monomer mixture, and the volume average particle diameter obtained in the above-mentioned seed particle production example 2 is 107g (solid matter 15.0 μ m) of the seed particle dispersion g) Polymer particles F were obtained in the same manner as in Example 1 except that the seed particle dispersion was used.

{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, Lactone-modified hydroxyethyl methacrylate (trade name "Praccel FM2D (registered trademark)" as a hydroxyl-containing monomer shown in the general formula (2), manufactured by Daicel Chemical Co., Ltd., the general formula ( 2) 50 g of the substance with n=2) and 8 g of 2,2'-azobisisobutyronitrile as a polymerization initiator were dissolved in each other to obtain a monomer mixture, and the volume average particle diameter obtained in the above-mentioned seed particle production example 2 Polymer particles G were obtained in the same manner as in Example 1 except that 107 g (15.0 g of solid content) of a seed particle dispersion of 1.01 μm was used as a seed particle dispersion.

{Comparative Example 2: Comparative Example of Polymer Particles}

200 g of styrene as a monofunctional styrenic monomer, 500 g of methyl methacrylate as a monofunctional (meth)acrylic monomer, 300 g of ethylene glycol dimethacrylate as a crosslinkable monomer, and After 8 g of 2,2'-azobisisobutyronitrile of the polymerization initiator were mutually dissolved to obtain a monomer mixture, 80 g (solid solid) of the seed particle dispersion with a volume average particle diameter of 0.45 μm obtained in the above-mentioned seed particle production example 1 was obtained. Product 11.2 g) was used as a seed particle dispersion, and the polymer particles H were obtained in the same manner as in Example 1.

{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, Poly(ethylene glycol-propylene glycol) monomethacrylate (trade name "Blenmer (registered trademark) 50PEP-300", manufactured by NOF Corporation) as a hydroxyl-containing monomer represented by the general formula (1) 200 g, 8 g of 2,2'-azobisisobutyronitrile as a polymerization initiator were mutually dissolved to obtain a monomer mixture, and 80 g of a seed particle dispersion with a volume average particle diameter of 0.45 μm obtained in the above-mentioned seed particle production example 1 (11.2 g of solid matter) Except having used it as a seed particle dispersion, it carried out similarly to Example 1, and obtained the polymer particle I.

{Comparative Example 4: Comparative Example of Polymer Particles}

240 g of styrene as a monofunctional styrenic monomer, 320 g of methyl methacrylate as a monofunctional (meth)acrylic monomer, and diethylene as a polymerizable vinyl monomer as a crosslinkable monomer Benzene 300g, poly(ethylene glycol-propylene glycol) monomethacrylate (trade name "Blenmer (registered trademark) 50PEP-300" as the hydroxyl-containing monomer shown in the general formula (1), NOF Co., Ltd.) 50 g and 8 g of 2,2'-azobisisobutyronitrile as a polymerization initiator were dissolved in each other to obtain a monomer mixture. Polymer particles J were obtained in the same manner as in Example 1 except that 14.3 g of the particle dispersion (2.0 g of solid matter) was used as the seed particle dispersion.

{Adjustment of dispersion liquid resin composition for anti-glare film and production of anti-glare film}

80 parts by weight of a mixture of pentaerythritol triacrylate and pentaerythritol tetraacrylate (trade name "Aronics (registered trademark) M-305", manufactured by Toagosei Co., Ltd.) as an ultraviolet curable resin, isopropanol ( 120 parts by weight of a mixture of IPA) and cyclopentanone (the volume ratio of IPA and cyclopentanone is 5:5), 5 parts by weight of polymer particles produced by the above-mentioned Examples 1-6 and Comparative Examples 1-4, photopolymerized Initiator (2-methyl-1-(4-methylphenylthio)-2-morpholinopropan-1-one, trade name "Irugakyua (registered trademark) 907", BASF (registered trademark)) Japan Co., Ltd. Co., Ltd.) 5 parts by weight were mixed to prepare a dispersion liquid resin composition for an antiglare film as a dispersion liquid resin composition.

A transparent plastic film, that is, a polyethylene terephthalate (PET) film with a thickness of 0.2 mm was prepared as a base film. The aforementioned dispersion for an anti-glare film was coated on one side of the aforementioned polyethylene terephthalate film with a bar coater having a wet film thickness of 60 μm to form a coating film. Then, the said coating film was heated at 80 degreeC for 1 minute, and the said coating film was dried. Afterwards, the above-mentioned coating film was irradiated with ultraviolet rays by a high-pressure mercury lamp at a cumulative light intensity of 300 mJ/cm ² to cure the above-mentioned coating film to obtain an anti-glare hard coat layer. In this manner, antiglare hard films containing the polymer particles produced in Examples 1 to 6 and Comparative Examples 1 to 4 were prepared as antiglare films (molded articles).

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

Hereinafter, the evaluation method of the antiglare property of the antiglare film produced by the said method is demonstrated. Each non-coated surface of the anti-glare film made is attached to an ABS resin (acrylonitrile-butadiene-styrene copolymer resin) plate, and is irradiated with a fluorescent lamp with a brightness of 10000cd/ ^cm2 from a place 2m away from the anti-glare film. On the coated surface, the antiglare property of the antiglare film was visually evaluated. The evaluation criteria for the anti-glare property are as follows: when the outline of the reflected image of the fluorescent lamp cannot be clearly seen, the anti-glare property is evaluated as "○" (good), and when the outline of the reflected image of the fluorescent lamp is clearly seen, the anti-glare property is evaluated as "×" (poor). .

For Examples 1 to 6 and Comparative Examples 1 to 4, the examples or comparative examples of the polymer particles, the volume average particle diameter (μm) of the seed particles used in the formation of the polymer particles are shown in Table 1, and the polymer particles are produced. The monomers used in "methyl methacrylate (MMA), n-butyl methacrylate (n-BMA), styrene (St), ethylene glycol dimethacrylate (EGDMA), divinylbenzene ( DVB), poly(ethylene glycol-propylene glycol) monomethacrylate (ブレンマー (registered trademark) 50PEP-300), lactone-modified hydroxyethyl methacrylate (プラクセル ((registered trademark) FM2D) input amount (g), monomer content (weight %), the measurement results of the volume average particle diameter (μm) and particle diameter variation coefficient (CV value (%)) of the polymer particles, the measured value of the hydroxyl value of the polymer particles (mgKOH /g), the evaluation results of the alcohol solvent dispersion test of the polymer particles, and the anti-glare evaluation results (coating evaluation) of the coating film (anti-glare film) formed by coating on the substrate film. And, the polymerization The content rate of the constituent unit derived from each monomer in the particle is represented by weight% in the form of acrylic monomer/styrene monomer/crosslinkable monomer/hydroxyl-containing monomer.

【Table 1】

The observation results of some polymer particles in Table 1 related to the evaluation results of the alcohol solvent dispersion test will be described. 1 and 2 are images showing the dispersion state of the polymer particles of Example 1 in the alcohol solvent dispersion test. 3 and 4 are images showing the dispersion state of the polymer particles of Comparative Example 2 in the alcohol solvent dispersion test. FIG. 1 shows the dispersion state of the polymer particles A in isopropanol, and FIG. 2 shows the dispersion state of the polymer particles A in methanol. In addition, FIG. 3 shows the dispersion state of the polymer particles H in isopropanol, and FIG. 4 shows the dispersion state of the polymer particles H in methanol. Comparing Figures 1 to 4, it can be seen that in Figures 1 and 2, the polymer particles A are dispersed approximately uniformly, while in Figures 3 and 4, the polymer particles are partially aggregated, and a uniform dispersion state is not obtained. As shown in Fig. 3 and Fig. 4, the polymer particle H has partial aggregation in both isopropanol solvent and methanol solvent, and the evaluation result of the alcohol solvent dispersion test shown in Table 1 is poor "×".

From the results shown in Table 1, it can be confirmed that when the volume average particle diameter of the polymer particles is 5 μm or less, and the hydroxyl value is 5.0 mgKOH/g or more and 15 mgKOH/g or less, the evaluation results of the alcohol solvent dispersion test and the antiglare evaluation results can achieve good results.

In addition, when any one of the polymer particle diameter and hydroxyl value exceeds the above-mentioned range, poor anti-glare property will result. In particular, the polymer particles H having a hydroxyl value of less than 5.0 mgKOH/g had a low evaluation in the alcohol solvent dispersion test and could not yet be coated. When the hydroxyl value is 5.0 mgKOH/g or more, it is considered to be uniformly dispersed in the dispersion medium, but when the hydroxyl value exceeds 15 mgKOH/g or the particle size exceeds 5 μm, the evaluation result of anti-glare property is low. The reason for this is that when the hydroxyl value is too high, it is considered that the cohesiveness is low in the process of forming a coating film after coating on the base film, and the protrusions that affect the anti-glare property cannot be sufficiently formed. In addition, when the volume average particle diameter of the polymer particles is larger than 5 μm, it is considered that the protrusions formed on the base film become steep and excessively scatter external light.

Furthermore, in Comparative Example 2 in which the structural unit derived from the hydroxyl group-containing monomer was less than 3% by weight, the dispersibility was insufficient and coating was difficult. In Comparative Example 3 in which the constituent units were more than 15%, the dispersibility after coating and drying was excessive, and the desired cohesiveness could not be obtained, and as a result, the target anti-glare property could not be obtained.

The present invention can be implemented in other various forms without departing from its spirit or main characteristics. Therefore, the above-mentioned embodiments are merely examples in all points, and should not be limitedly interpreted. The scope of the present invention is shown in the claims and is not restricted by the text of the description. Furthermore, modifications and changes falling within the equivalent scope of the claims all belong to the scope of the present invention.

【Industrial availability】

The polymer particles of the present invention are coated on a base film as a dispersion liquid dispersed by a binder, for example, to be used as an optical film such as a light diffusion film or an antiglare film, an optical member such as a light diffusion plate, or as an optical component such as a light diffusion plate. Other fields can be utilized for various purposes.

Claims (8)

1. A kind of polymer particle, it is characterized in that, comprise: come from the constituent unit of the hydroxyl-containing monomer represented by following general formula (1) and/or following general formula (2), from monofunctional (methyl ) constituent units of acrylic monomers, monofunctional styrenic monomers, and constituent units derived from crosslinkable monomers, The volume average particle diameter of the polymer particles is 5 μm or less, the hydroxyl value is 5.0 mgKOH/g or more and 15 mgKOH/g or less, Formula (1) In the general formula (1), R represents H or CH ₃ , m represents a number from 0 to 50, n represents a number from 0 to 50, m and n are not 0 at the same time, Formula (2) In the general formula (2), R each independently represents H or CH ₃ , and p represents a number from 1 to 50. 2. The polymer particle according to claim 1, characterized in that The structural unit derived from the said hydroxyl-containing monomer contains 3-15 weight%. 3. Polymer particles according to claim 1 or 2, characterized in that The structural unit derived from the said crosslinkable monomer is contained in 3 to 35 weight%. 4. Polymer particles according to claim 1 or 2, characterized in that At least a monofunctional (meth)acrylic monomer whose solubility in water at 25° C. is 0.45% by weight or less is included. 5. The polymer particle according to claim 1 or 2, characterized in that The polymer particles are used in optical components. 6. A method for producing polymer particles, comprising polymerizing vinyl monomers to produce polymer particles, characterized in that, The vinyl monomers include hydroxyl-containing monomers represented by the following general formula (1) and/or the following general formula (2), monofunctional (meth)acrylic monomers, monofunctional styrenes monomers and cross-linking monomers, containing 3 to 15% by weight of the hydroxyl-containing monomer relative to the total amount of the vinyl monomer, The polymerization of the vinyl monomer is seed polymerization performed by seed particles absorbing the vinyl monomer in an aqueous medium, Formula (1) In the general formula (1), R represents H or CH ₃ , m represents a number from 0 to 50, n represents a number from 0 to 50, m and n are not 0 at the same time, Formula (2) In the general formula (2), R each independently represents H or CH ₃ , and p represents a number from 1 to 50. 7. A dispersion liquid, characterized in that, The polymer particle according to any one of claims 1 to 5 and a binder are contained, and the polymer particle is dispersed in the binder as a dispersoid. 8. An optical film, characterized in that, The dispersion liquid described in claim 7 is applied on a substrate film.