TWI579325B - Composite particle, method for fabricating the same and usage thereof - Google Patents

Description

Composite particle, composite particle manufacturing method and use thereof

The present invention relates to a composite particle, a method for producing the composite particle, and a use thereof (external preparation, a coating agent, an optical film, a resin composition, and a molded body), wherein the composite particles comprise polymer particles, A cerium oxide particle attached to the surface of the polymer particle.

Polymer particles having an average particle diameter of from 0.01 μm to 100 μm are, for example, additives for coating agents such as paints (such as matting agents), additives for inks (such as matting agents), main components or additives for adhesives, and additives for artificial marble (low Filling materials for external preparations such as shrinkage agents, paper treatment agents, and cosmetics (fillers for improving slidability), column packing materials used in chromatography, and toning used in electrostatic image development It is used for additives such as an agent, an anti-blocking agent for a film, a light diffusing agent for a light diffusing film (such as a light diffusing film), and the like.

The above polymer particles are usually produced by suspension polymerization of a polymerizable monomer. In the suspension polymerization, in order to polymerize droplets containing a polymerizable monomer in a system in which droplets are not uniform and droplets are stably suspended, a suspension stabilizer such as cerium oxide can be used. Thereby, fine polymer particles having a uniform particle size distribution can be obtained.

For example, Patent Document 1 discloses a method of stirring a composition containing an aqueous medium, a polymerizable monomer, a polymerization initiator, an inorganic dispersant (for example, colloidal cerium oxide), and an emulsifier to form a composition. a step of dispersing a liquid of oil droplets in an aqueous medium; and a step of heating the above-mentioned polymerizable monomer while stirring the mixture. By this method, resin particles (polymer particles) having a concentrated particle diameter can be obtained.

[Previous Technical Literature]

[Patent Literature]

[Patent Document 1] International Publication No. 2011/062173

However, in recent years, as one of methods for imparting new properties to polymer particles or improving properties of polymer particles, it is considered to combine ruthenium dioxide particles in polymer particles. For example, when the cerium oxide particles are attached to the surface of the polymer particles, the hydrophilicity of the surface of the particles or the hardness of the particles themselves can be improved. Since the particles having hydrophilicity on the surface are easily dispersed in an aqueous medium, they can be suitably used as a raw material for an aqueous external preparation such as an aqueous coating agent (such as a matting agent) such as an aqueous coating material or a lotion. In addition, when the hardness of the particles themselves is increased, when it is used as an additive of a coating agent such as a paint, improvement in scratch resistance can be expected.

By the method disclosed in Patent Document 1, resin particles having a coating amount of the inorganic dispersant on the surface of the resin particles of 0.0001 g/m ² to 0.02 g/m ² can be obtained. However, the object of this method is to obtain resin particles (polymer particles) having a small amount of adhesion of an inorganic dispersant such as ceria on the surface, and by this method, adhesion of an inorganic dispersant to the surface of the resin particles can be suppressed. Therefore, the cerium oxide particles adhering a small amount on the surface of the resin particles obtained by this method do not strongly adhere to the surface of the resin particles, and are liable to fall off from the resin particles.

In view of the above circumstances, an object of the present invention is to provide a method for producing composite particles in which composite particles having difficulty in detachment of cerium oxide particles from the surface of polymer particles, and composite particles obtained by the production method. The use of composite particles.

The method for producing composite particles of the present invention is a method for producing composite particles comprising polymer particles and cerium oxide particles attached to the polymer particles, characterized in that it comprises a polymerization step, that is, adsorption of water-soluble cellulose on the surface In the presence of the cerium oxide-like particles, the polymerizable monomer is subjected to aqueous suspension polymerization to obtain composite particles.

In the production method, the polymerizable monomer is subjected to aqueous suspension polymerization in the presence of water-soluble cellulose-based cerium oxide particles adsorbed on the surface, and thus the water-soluble cellulose adsorbed on the surface of the cerium oxide particles The effect is that the cerium oxide particles can be firmly attached to the surface of the polymer particles. Therefore, composite particles in which the cerium oxide particles are hard to fall off from the surface of the polymer particles can be obtained.

Further, the composite particles of the present invention are characterized by comprising polymer particles, cerium oxide particles adhering to the surface of the polymer particles, and water-soluble cellulose.

In the composite particles, since the cerium oxide particles are firmly adhered to the surface of the polymer particles because they contain water-soluble cellulose, the cerium oxide particles are difficult to self-polymerize. The surface of the composite particles is detached.

Further, the external preparation of the present invention is characterized by comprising the composite particles of the present invention.

The external preparation of the present invention contains the composite particles of the present invention and thus has good slidability. Further, when the external preparation of the present invention contains an aqueous solvent, good dispersibility of the composite particles is obtained due to the hydrophilicity of the ceria particles adhering to the surface of the polymer particles.

Moreover, the coating agent of the present invention is characterized by comprising the composite particles of the present invention.

Since the coating agent of the present invention contains the composite particles of the present invention, it is possible to impart light diffusibility to the coating film formed by the coating agent. Further, in the coating agent of the present invention, since the hardness of the composite particles is ensured by the cerium oxide particles adhering to the surface of the polymer particles, the scratch resistance of the coating film formed of the coating agent can be expected. improve. Further, in the case where the coating agent of the present invention contains an aqueous solvent, good dispersibility of the composite particles is obtained due to the hydrophilicity of the ceria particles adhered to the surface of the polymer particles.

Further, the optical film of the present invention is characterized in that a coating agent is applied onto a substrate.

The optical film of the present invention contains the coating agent of the present invention and thus has light diffusibility.

Further, the resin composition of the present invention is characterized by comprising the composite particles of the present invention and a base resin.

The resin composition of the present invention has light diffusibility due to the inclusion of the composite particles of the present invention.

The molded article of the present invention is characterized in that the resin composition of the present invention is molded.

Since the molded article of the present invention is formed by molding a resin composition containing the composite particles of the present invention, the molded article of the present invention has light diffusibility by containing the composite particles of the present invention.

According to the present invention, a method for producing composite particles capable of obtaining composite particles in which cerium oxide particles are hard to be detached from the surface of the polymer particles, a composite particle obtained by the production method, and a use of the composite particles can be provided.

Fig. 1 is an enlarged view showing a transmission electron microscope (TEM) image of a part of a cross section of the composite particles obtained in Example 1 of the present invention.

2 is a transmission electron microscope (TEM) image of a cross section of the composite particles obtained in Example 1 of the present invention, which is an image in which an interface portion between polymer particles and cerium oxide particles is enlarged.

Hereinafter, the present invention will be described in more detail.

[Manufacturing method of composite particles]

The manufacturing method of the present invention comprises polymer particles attached to the polymer particles A method for producing composite particles of cerium oxide particles. This production method includes a polymerization step in which a polymerizable monomer is subjected to aqueous suspension polymerization in the presence of a water-soluble cellulose-based cerium oxide particle adsorbed on the surface to obtain a composite particle.

(polymerizable monomer)

The polymerizable monomer used in the production method of the present invention is not particularly limited, and for example, a compound having no phosphate bond and having a polymerizable carbon-carbon double bond (generalized ethylene bond) is preferred (hereinafter It is simply referred to as a polymerizable vinyl monomer).

The polymerizable vinyl monomer is not particularly limited, and examples thereof include a monofunctional monomer having one alkenyl group (generalized vinyl group) and a polyfunctional monomer having two or more alkenyl groups (generalized vinyl groups).

Examples of the above monofunctional monomer include an α-methylene aliphatic monocarboxylic acid ester; styrene; o-methyl styrene, m-methyl styrene, p-methyl styrene, p-ethyl styrene, 2, 4 - dimethyl styrene, p-n-butyl styrene, p-tert-butyl styrene, p-n-hexyl styrene, p-n-octyl styrene, p-n-decyl styrene, p-n-decyl styrene, pair Styrene derivatives such as n-dodecylstyrene, p-methoxystyrene, p-phenylstyrene, p-chlorostyrene, 3,4-dichlorostyrene; vinyl acetate, vinyl propionate, butyl a vinyl carboxylate such as vinyl acetate; an acrylic acid derivative other than an acrylate such as acrylonitrile or acrylamide; or a methacrylic acid other than a methacrylate such as methacrylonitrile or methacrylamide. Derivatives, etc.

The above α-methylene aliphatic monocarboxylic acid ester may, for example, be methyl acrylate, ethyl acrylate, propyl acrylate, n-butyl acrylate, isobutyl acrylate, n-octyl acrylate, dodecyl acrylate or acrylic acid. 2-ethylhexyl ester, stearyl acrylate, Lauryl acrylate, 2-chloroethyl acrylate, phenyl acrylate, 2-(dimethylamino)ethyl acrylate, 2-(diethylamino)ethyl acrylate, 2-hydroxy acrylate Ethyl ester, acrylate such as 2-hydroxypropyl acrylate; methyl methacrylate, ethyl methacrylate, propyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, methacrylic acid Octyl ester, dodecyl methacrylate, 2-ethylhexyl methacrylate, stearyl methacrylate, lauryl methacrylate, phenyl methacrylate, methacrylic acid-2- (Dimethylamino)ethyl ester, 2-(diethylamino)ethyl methacrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, etc. Α-haloacrylic acid ester or the like such as α-chloroacrylate.

As the monofunctional monomer, an α,β-unsaturated carboxylic acid such as acrylic acid, methacrylic acid, maleic acid or fumaric acid may also be used as the case may be. Further, two or more kinds of these compounds may be used in combination. In addition, one type of the following compounds or a combination of two or more types may be used as a monofunctional monomer in the range which does not inhibit the effects of the present invention: vinyl methyl ether, vinyl ethyl ether, vinyl Vinyl ethers such as butyl ether; vinyl ketones such as vinyl methyl ketone, vinyl hexyl ketone, and methyl isopropenyl ketone; N-vinyl pyrrole, N-vinyl oxazole, N-vinyl fluorene An N-vinyl compound such as N-vinylpyrrolidone; a vinyl naphthalene salt or the like.

Further, in the present invention, the above-mentioned monofunctional monomers may be used alone or in combination of two or more. Further, among the above monofunctional monomers, styrene or methyl methacrylate is inexpensive, and therefore it is more preferable as the monofunctional monomer used in the present invention.

The above polyfunctional monomer may, for example, be divinylbenzene; ethylene glycol di(meth)propyl Ethyl ester, polyethylene glycol di(meth)acrylate (repeating unit number is 2~10), propylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate (repeating unit number is 2~) 10), 1,3-butanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate, alkoxylated neopentyl glycol di(meth)acrylate, propoxylation Bifunctional alkanediol di(methyl) such as neopentyl glycol di(meth)acrylate, hydroxypivalic acid neopentyl glycol di(meth)acrylate, dioxanediol di(meth)acrylate Acrylate; butanediol di(meth)acrylate, hexanediol di(meth)acrylate, alkoxylated hexanediol di(meth)acrylate, cyclohexanediol di(methyl) Bifunctional alkanediol di(meth)acrylate such as acrylate, dodecanediol di(meth)acrylate, tricyclodecanediol di(meth)acrylate; ethoxylation (repeating unit) 2 to 10) bifunctional bisphenol A di(meth)acrylate such as bisphenol A di(meth)acrylate; trimethylolpropane tri(meth)acrylate, ethoxylate Trimethylolpropane tri(meth)acrylate, pentaerythritol Trifunctional trimethylolpropane tri(meth)acrylates such as (meth) acrylate and tripropylene methoxyethyl phosphate; pentaerythritol tetra(meth) acrylate, di-trimethylolpropane IV 4-functional tetrakis(meth)acrylate such as (meth)acrylate; 6-functional dipentaerythritol hexa(meth)acrylate such as dipentaerythritol hexa(meth)acrylate; and 8-functional pentaerythritol such as poly(pentaerythritol) acrylate (Meth) acrylates; such as trifunctional nitrogen-containing cyclic (meth) acrylates such as ethoxylated tris (meth) acrylate. Further, in the specification of the present application, "(meth) acrylate" means methacrylate or acrylate.

In the production method of the present invention, when the polymerizable vinyl monomer is used as the polymerizable monomer, the polymerizable vinyl monomer is preferably a package. Both monofunctional monomers and polyfunctional monomers are included. Thereby, a good crosslinked structure is formed in the polymer particles, and the composite particles can be imparted with good solvent resistance. The amount of the polyfunctional monomer to be used is preferably in the range of 0.5% by weight to 50% by weight, and more preferably in the range of 1% by weight to 40% by weight based on the total amount of the polymerizable vinyl monomer. Thereby, a more favorable crosslinked structure is formed in the polymer particles, and the composite particles can be more excellent in solvent resistance.

In the production method of the present invention, the polymerizable monomer may be used alone, or the polymerizable vinyl monomer may be used in the following manner depending on the type of the water-soluble cellulose to be described later. The polymerizable phosphate monomers represented by the formulae (1) to (5) are used in combination. By using the above-mentioned polymerizable vinyl monomer together with the above polymerizable phosphate monomer in accordance with the type of the water-soluble cellulose to be described later, the polymerizable property in the aqueous medium can be obtained in the aqueous suspension polymerization of the polymerizable monomer. The stability of the droplets of the monomer is improved. Therefore, in the production method of the present invention, the above polymerizable phosphate-based monomer can be suitably used together with the above-mentioned polymerizable vinyl monomer.

(In the formula (1), n is 1 to 5, when a is 1, b is 2, and when a is 2, b is 1)

(in equation (3), n is 1~5)

(in the formula (5), n is 1 to 6)

Specific examples of the polymerizable phosphate-based monomer represented by the above formula (1) include "KAYAMER (registered trademark) PM-21 manufactured by Nippon Kasei Co., Ltd. (in the above formula (1), n = 1) A compound having a = 1 and b = 2, and a molar ratio of 1 to 1 in a molar ratio of a compound of n = 1, a = 2, and b = 1 in the above formula (1). In addition, as a specific example of the polymerizable phosphate-based monomer represented by the above formula (2), "KAYAMER (registered trademark) PM-2" manufactured by Nippon Kasei Co., Ltd., manufactured by Kyoeisha Chemical Co., Ltd. "Light ester P-2M" and so on. In addition, as a specific example of the polymerizable phosphate-based monomer represented by the above formula (3), "KAYAMER (registered trademark) PM-1" manufactured by Nippon Kasei Co., Ltd. (in the above formula (3), n "Light ester P-1M" manufactured by Kyoeisha Chemical Co., Ltd. (a compound of n = 1 in the above formula (3)), and "Phosmer (registered trademark) manufactured by Uni-Chemical Co., Ltd.) M" (a compound of n = 1 in the above formula (3)), "Phosmer (registered trademark) PE" manufactured by Uni-Chemical Co., Ltd. (a compound of n = 4 to 5 in the above formula (3)) Wait. In addition, as a specific example of the polymerizable phosphate-based monomer represented by the above formula (4), "Phosmer (registered trademark) CL" manufactured by Uni-Chemical Co., Ltd., or the like can be mentioned. Further, as a specific example of the polymerizable phosphate monomer represented by the above formula (5), it can be listed. "Phosmer (registered trademark) PP" (a compound of n = 5 to 6 in the above formula (5)) manufactured by Uni-Chemical Co., Ltd., and the like.

In the present invention, when the polymerizable phosphate-based monomer and the polymerizable vinyl monomer are used in combination, the polymerizable phosphate-based monomer is used in an amount of 100 parts by weight based on 100 parts by weight of the polymerizable vinyl monomer. The amount used is preferably in the range of 0.01 part by weight to 1 part by weight, more preferably 0.01 part by weight to 0.8 part by weight. When the amount of the polymerizable phosphate-based monomer used is more than 1 part by weight based on 100 parts by weight of the polymerizable vinyl monomer, the amount of the polymerizable phosphate-based monomer is as follows: emulsified particles (emulsified) are easily formed during polymerization. The composite particles having an excessively small particle diameter such as the by-product fine particles of the polymerization have a large coefficient of variation in the particle diameter of the composite particles.

(aqueous medium)

In the above polymerization step of the production method of the present invention, the aqueous medium for carrying out the aqueous suspension polymerization of the polymerizable monomer may, for example, be water or a mixed medium of water and a water-soluble medium (for example, an alcohol such as methanol or ethanol). The amount of the aqueous medium to be used is preferably from 100 parts by weight to 1000 parts by weight per 100 parts by weight of the polymerizable monomer in order to stabilize the composite particles.

(polymerization initiator)

In the above polymerization step of the production method of the present invention, it is preferred to carry out aqueous suspension polymerization of the above polymerizable monomer in the presence of a polymerization initiator.

As the polymerization initiator, an oil-soluble peroxide-based polymerization initiator or an azo-based polymerization initiator used in aqueous suspension polymerization can be suitably used.

The peroxide-based polymerization initiator may, for example, be benzoic acid peroxide. 醯, peracidated laurel, peracid octyl, o-chloroperoxybenzaldehyde, o-methoxyperoxybenzidine, methyl ethyl ketone peroxide, diisopropyl peroxydicarbonate, cumene Hydrogen peroxide, cyclohexanone peroxide, tert-butyl hydroperoxide, diisopropylbenzene hydroperoxide, and the like.

Examples of the above azo polymerization initiator include 2,2'-azobisisobutyronitrile, 2,2'-azobis(2,4-dimethylvaleronitrile), and 2,2'-azo. Bis(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-aminoformamidoazo)isobutyronitrile, 4,4'-azobis(4-cyanovaleric acid), 2,2' - dimethyl azobisisobutyrate or the like.

Among the above polymerization initiators, 2,2'-azobisisobutyronitrile and 2,2'-azobis(2,4-dimethylvaleronitrile) are preferred from the viewpoints of decomposition rate and the like. Benzoyl peroxide, peracidated laurel, etc. are polymerization initiators which can be used in the production method of the present invention.

The amount of the polymerization initiator to be used is preferably from 0.01 part by weight to 10 parts by weight, more preferably from 0.1 part by weight to 5.0 parts by weight, per 100 parts by weight of the polymerizable monomer. When the amount of the polymerization initiator used is less than 0.01 part by weight based on 100 parts by weight of the polymerizable monomer, it is difficult to sufficiently achieve the function of starting polymerization; and if it exceeds 10 parts by weight, it is not obtained. The effect that matches the amount used is not economical and therefore not good.

(The surface is adsorbed with water-soluble cellulose-based cerium oxide particles)

In the above polymerization step of the production method of the present invention, the above polymerizable monomer The aqueous suspension polymerization is carried out in the presence of cerium oxide particles adsorbed with water-soluble cellulose. In the above polymerization step, the above-described water-soluble cellulose-based cerium oxide particles are adsorbed as a suspension stabilizer.

The cerium oxide particles are not particularly limited, and any known cerium oxide particles can be used arbitrarily, and those having an average primary particle diameter of 500 nm or less are preferably used. When cerium oxide particles having an average primary particle diameter of more than 500 nm are used, the amount of addition necessary for stably performing suspension polymerization increases, which is uneconomical, and it is difficult to stably disperse the above-mentioned polymerizable monomer, which is not preferable. Further, the average primary particle diameter of the above cerium oxide particles is preferably as small as possible, more preferably in the range of 5 nm to 150 nm, still more preferably in the range of 8 nm to 100 nm.

As the above cerium oxide particles, colloidal cerium oxide can be preferably used. The colloidal cerium oxide may, for example, be a powdered colloidal cerium oxide such as a deposited cerium oxide powder or a vapor phase cerium oxide powder; or a colloidal cerium oxide sol which is stably dispersed in a medium to a primary particle level. Among these, a colloidal cerium oxide sol which is stably dispersed in a medium to a primary particle level is more suitable for use in the production method of the present invention.

As the colloidal cerium oxide sol, an aqueous cerium oxide sol, an organic cerium oxide sol or the like can be suitably used. In particular, in the production method of the present invention, in order to carry out aqueous suspension polymerization of a polymerizable monomer (that is, an aqueous medium is used in polymerization of a polymerizable monomer), in terms of dispersion stability of the colloidal cerium oxide sol The best is to use aqueous colloidal cerium oxide. The concentration of cerium oxide (solid content concentration) in the colloidal cerium oxide sol is usually 5% to 50% by weight, which is easily obtained, and is therefore preferable.

As a commercially available product of the above-mentioned colloidal cerium oxide, a Snowtex (registered trademark) series manufactured by Nissan Chemical Industries Co., Ltd., for example, a general-purpose Snowtex (registered trademark) having a spherical particle diameter of 5 nm to 100 nm (alkaline) : "ST-XS", "ST-30", "ST-50", "ST-30L", "ST-ZL", Acidity: "ST-OXS", "ST-O", "ST-O-" 40", "ST-OL", "ST-OZL35"), and large-sized Snowtex (registered trademark) of spherical particles with a particle size of 70 nm to 480 nm (alkaline: "ST-MP-2040", "ST-MP" -4540M"), a chain-shaped Snowtex (registered trademark) (alkaline: "ST-UP", acid: "ST-OUP") having a diameter of 40 nm to 100 nm, and a ball having a particle diameter of 10 nm to 25 nm Snowtex (registered trademark) of pearl necklace type (alkaline: "ST-PS-S", "ST-PS-M", acidity: "ST-PS-SO", "ST-PS" -MO") and so on.

The amount of the cerium oxide particles used (hereinafter referred to as the amount of addition) is preferably such that the composite particles obtained by the present production method have a surface area per unit surface of from 0.022 g/m ² to 0.15 g/m ² . When the amount of the cerium oxide particles added is less than 0.022 g/m ² , in the composite particles, the adhesion of the cerium oxide particles to the surface of the polymer particles is insufficient; In the case of g/m ² , there is a problem that failure to obtain an effect that matches it is uneconomical.

The water-soluble cellulose to be adsorbed on the cerium oxide particles is not particularly limited, and examples thereof include alkyl celluloses such as methyl cellulose; hydroxymethyl cellulose, hydroxyethyl cellulose, and hydroxypropyl A hydroxyalkylcellulose such as a cellulose or a compound such as a hydroxyalkylalkylcellulose such as hydroxyethylmethylcellulose or hydroxypropylmethylcellulose. Among these compounds, preferred are hydroxyalkyl celluloses and hydroxyalkyl groups. Cellulose, more preferably hydroxypropylcellulose (HPC), hydroxypropylmethylcellulose (HPMC). Further, these compounds may be used alone or in combination of two or more.

It is known that hydroxypropylcellulose (HPC) generally has a lower critical solution temperature (LCST) of 45 ° C, and commercially available products include, for example, the NISSO (registered trademark) HPC series manufactured by Japan Soda Co., Ltd. ( "SSL", "SL", "L", "M", "H", etc.).

Further, a commercially available product of hydroxypropylmethylcellulose (HPMC) may be a METOLOSE (registered trademark) series manufactured by Shin-Etsu Chemical Co., Ltd., and more specifically, a clouding point having a temperature of 60 °C. METOLOSE (registered trademark) 60SH series ("SH60-50", "60SH-4000", "60SH-10000"), METOLOSE (registered trademark) 65SH series with 65 °C cloud point ("65SH-50", "65SH METOLOSE (registered trademark) 90SH series ("90SH-100", "90SH-400", "90SH-4000") with a cloud point of 90 °C, -400", "65SH-1500", "65SH-4000") "90SH-15000") and so on.

The amount of the water-soluble cellulose to be adsorbed on the above-mentioned ceria particles is not particularly limited, and can be appropriately set according to the specific surface area of the ceria particles used in the present invention, and it is preferable to per gram of the above-mentioned ceria. The particles are 0.05g~0.5g.

In addition, the amount of the water-soluble cellulose adsorbed on the cerium oxide particles can be, for example, the Japanese Journal of Polymer Science and Technology published by the Society of Polymer Science and Technology. Volume 40, No. 10, page 697 - page 702 (1983) It is measured by the method described in October). For example, it can be measured by [method of measuring the amount of adsorption of water-soluble cellulose on cerium oxide particles] described in the section of the examples described later.

Preferably, the production method of the present invention comprises an adsorption step prior to the polymerization step, that is, the water-soluble cellulose is adsorbed to the cerium oxide by treating the cerium oxide particles with the water-soluble cellulose. Particle surface.

The treatment method of the above-described water-soluble cellulose-based cerium oxide particles for adsorbing the water-soluble cellulose on the surface of the cerium oxide particles is not particularly limited, and a known method can be applied. For example, it is preferred to A method in which a cerium oxide particle and a water-soluble cellulose are coexisted in an aqueous medium, and a water-soluble cellulose is physically adsorbed on the surface of the cerium oxide particle (specifically, a polymer polymerization adsorbed onto the cerium oxide particle in advance) Rheological and Interfacial Properties of Silicone Oil Emulsions Prepared by Polymer Pre-adsorbed onto Silica Particles, Colloid and Interface A: Physicochemical and Engineering Aspects (Colloids Surfaces A: Physicochem.Eng .Aspects), 328, 2008, 114-122. The water-soluble cellulose adsorbed on the ceria particles by this treatment method is substantially not desorbed from the ceria particles in the above polymerization step, and is in a stable state.

Further, it is more preferable that the water-soluble cellulose (T-15) ° C (T represents a lower limit critical solution temperature (° C.) or a cloud point (° C.) of the water-soluble cellulose) Is (T-15) °C or higher, (T+20) °C or lower temperature Under the condition, the cerium oxide particles and the water-soluble cellulose are coexisted, whereby the water-soluble cellulose can be more effectively adsorbed on the surface of the cerium oxide particles. Further, the water-soluble cellulose described above has only one of the lower limit critical co-solvation temperature or the cloud point depending on its characteristics.

Further, in the adsorption step, the water-soluble cellulose not adsorbed on the ceria particles may be removed by centrifugation or the like before the polymerization step, or may be obtained after the above polymerization step. The composite particles are removed by washing in a purification step for purification.

Further, in the production method of the present invention, in the polymerization step, the effect of improving the suspension stability by the cerium oxide particles adsorbing the water-soluble cellulose may be further prevented. Other suspension stabilizers other than the above cerium oxide particles.

(surfactant)

In the above polymerization step of the production method of the present invention, in order to further improve the suspension stability, aqueous suspension polymerization of the above polymerizable monomer can be carried out in the presence of a surfactant. As the above surfactant, any of an anionic surfactant, a cationic surfactant, an amphoteric surfactant, and a nonionic surfactant can be used.

Examples of the anionic surfactant include sodium oleate; fatty acid soaps such as castor oil potassium soap; alkyl sulfates such as sodium lauryl sulfate and ammonium lauryl sulfate; and alkylbenzenesulfonic acids such as sodium dodecylbenzenesulfonate. Salt; alkylnaphthalene sulfonate; alkane sulfonate; dialkyl sulfosuccinate; alkyl phosphate; sulphate naphthalene condensate; Ethylene alkyl phenyl ether sulfate salt; polyoxyethylene alkyl sulfate salt, and the like.

Examples of the nonionic surfactant include polyoxyethylene alkyl ether, polyoxyethylene alkylphenyl ether, polyoxyethylene fatty acid ester, sorbitan fatty acid ester, and polyoxyethylene sorbitan fatty acid ester. , polyoxyethylene alkylamine, glycerin fatty acid ester, oxyethylene-oxypropylene block polymer, and the like.

Examples of the cationic surfactant include alkylamine salts such as laurylamine acetate and stearylamine acetate; and quaternary ammonium salts such as lauryl trimethylammonium chloride.

Examples of the zwitterionic surfactant include lauryl dimethyl amine oxide, a phosphate ester surfactant, and a phosphite surfactant.

These surfactants may be used singly or in combination of two or more. The surfactant can be appropriately selected in consideration of the diameter of the obtained composite particles or the dispersion stability of the polymerizable monomer in the aqueous suspension polymerization, and the amount of use can be appropriately adjusted.

(polymerization inhibitor)

In the above polymerization step of the production method of the present invention, in order to suppress the generation of emulsified particles in the aqueous system, aqueous suspension polymerization of the above polymerizable monomer may be carried out in the presence of a water-soluble polymerization inhibitor.

Examples of the water-soluble polymerization inhibitor include nitrites, sulfites, hydroquinones, ascorbic acids, water-soluble vitamin Bs, citric acid, and polyphenols.

(other additives)

In the above polymerization step of the production method of the present invention, it is also possible not to hinder the hair Within the range of the effect of the brightening, aqueous suspension polymerization of the above polymerizable monomer is carried out in the presence of other additives such as a pigment, a dye, an antioxidant, an ultraviolet absorber or the like.

Examples of the pigment include inorganic pigments such as lead white, lead dancil, chrome yellow, carbon black, ultramarine blue, zinc oxide, cobalt oxide, titanium oxide, iron oxide, titanium yellow, and titanium black; and yellow, naphthol yellow S, and Hansa yellow. Yellow pigment such as 10G, benzidine yellow G, benzidine yellow GR, quinoline yellow lake, permanent solid yellow NCG, tartar yellow lake; molybdenum orange, permanent orange RK, benzidine orange G, indanthrene bright orange GK Etc. orange pigment; permanent red 4R, liguxine red, pyrazolone, red 4R, watching red calcium salt, lake red D, bright carmine 6B, reddish lake, rose red lake B, red pigments such as alizarin lake, bright carmine B; purple pigments such as fast purple B, methyl violet lake, dioxane violet; alkaline blue lake, Victoria blue lake, phthalocyanine blue, metal-free germanium Blue cyanine, phthalocyanine blue partial chloride; fast blue, indanthrene blue BC and other blue pigments; pigment green B, peacock green lake, final yellow green G and other green pigments; isoindolinone pigment, quinacridine Ketone pigment, picone pigment, anthraquinone pigment, insoluble azo pigment, soluble azo pigment, dyed lake pigment Organic pigments.

Examples of the dye include a nitroso dye, a nitro dye, an azo dye, a quinone-azo dye, a diphenylmethane dye, a triphenylmethane dye, a dibenzopyran dye, an acridine dye, and a quinoline dye. , methine dyes, polymethine dyes, thiazole dyes, indamine dyes, indophenol dyes, azine dyes, oxazine dyes, thiazine dyes, sulfur dyes, and the like.

The above antioxidant may, for example, be 2,6-di-tert-butyl-4-methylphenol (BHT), n-octadecyl-3'-(3',5'-di-t-butyl-4' -hydroxyphenyl)propionate, Pentaerythritol-tetrakis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate], 1,3,5-tris(3,5-di-t-butyl-4- Hydroxybenzyl)isomeric cyanurate, 1,3,5-trimethyl-2,4,6-tris(3,5-di-t-butyl-4-hydroxybenzyl)benzene, 3, 9-bis[2-{3-(3-t-butyl-4-hydroxy-5-methylphenyl)propanoxy}-1,1-dimethylethyl]-2,4,8 a phenolic antioxidant such as 10-tetraoxaspiro[5.5]undecane; distearyl pentaerythritol diphosphite, tris(2,4-di-t-butylphenyl)phosphite, bis ( 2,4-di-t-butylphenyl)pentaerythritol diphosphite, tetrakis(2,4-di-t-butylphenyl) 4,4'-extended biphenyl diphosphite, double 2-tert-butyl-4-methylphenyl)pentaerythritol diphosphite, 2,4,8,10-tetra-tert-butyl-6-[3-(3-methyl-4-hydroxy- Phosphorus-based antioxidants such as 5-t-butylphenyl)propoxy]dibenzo[d,f][1,3,2]dioxin cycloheptane; phenyl-1-naphthylamine, octyl An amine-based antioxidant such as diphenylamine, 4,4-bis(α,α-dimethylbenzyl)diphenylamine or N,N'-di-2-naphthyl-p-phenylenediamine.

Examples of the ultraviolet absorber include a benzophenone-based ultraviolet absorber and a benzotriazole-based ultraviolet absorber (for example, "Adekastab (registered trademark) LA-31" manufactured by ADEKA Co., Ltd.), and hydroxybenzene. A triazine-based ultraviolet absorber or the like.

(Method of suspension polymerization)

In the polymerization step of the production method of the present invention, the polymerizable monomer is subjected to aqueous suspension polymerization in the presence of the water-soluble cellulose-based cerium oxide particles adsorbed on the surface. For example, in the above polymerization step, a polymerization initiator is optionally mixed with a polymerization initiator and/or a polymerization inhibitor and/or other additives to prepare a monomer mixture, and the prepared monomer mixture is dispersed on the surface containing the adsorption. Water soluble cellulose Aqueous suspension polymerization is carried out in an aqueous medium of a cerium oxide-like particle (including a surfactant and/or other suspension stabilizer as needed).

As a method of dispersing a monomer mixture in an aqueous medium, for example, a method in which a monomer mixture is directly added to an aqueous medium and dispersed into a monomer droplet by a stirring force of a propeller blade or the like; A monomer mixture is directly added to the medium, and a monomer mixture is dispersed in an aqueous medium using a homomixer comprising a rotor and a stator and a high shear disperser; in an aqueous medium a method of directly adding a monomer mixture, dispersing a monomer mixture in an aqueous medium using an ultrasonic disperser, directly adding a monomer mixture to an aqueous medium, and using a high-pressure disperser such as a microfluidizer or a nanochemical machine. A method of dispersing a monomer mixture into a droplet in an aqueous medium by collision of droplets of a monomer mixture with each other or collision of droplets of a monomer mixture with an inner wall of a reaction vessel; by MPG (microporous glass) porous membrane A method of pressing a monomer mixture into an aqueous medium or the like. In these methods, the method of using a high-pressure type disperser such as a microfluidizer or a nano-machine, or the method of using the MPG (microporous glass) porous film described above can concentrate the particle size more uniformly, and thus can be used as The method of dispersing the monomer mixture in an aqueous medium is preferably used.

Next, suspension polymerization is initiated by heating an aqueous medium (aqueous suspension) in which a monomer mixture is dispersed. Preferably, the aqueous suspension is stirred during the polymerization. The stirring may be carried out to such an extent that, for example, the monomer mixture is prevented from floating as droplets and the composite particles generated by the polymerization are sedimented.

In suspension polymerization, the polymerization temperature is preferably set to 30 ° C to 120 ° C. In the range, it is more preferable to set it in the range of 40 ° C to 80 ° C. The time for maintaining the polymerization temperature is preferably in the range of 0.1 hour to 20 hours.

After the completion of the polymerization, the obtained composite particles can be separated into an aqueous filter cake by suction filtration, centrifugal dehydration, centrifugal separation, pressurized dehydration, etc., and the obtained aqueous filter cake is further washed with water and dried as needed. Thereby, the target composite particles can be obtained.

The size and shape of the composite particles of the present invention are not particularly limited, and composite particles having a volume average particle diameter of from 1 μm to 100 μm can be obtained by the method for producing the composite particles.

Further, the average particle diameter of the obtained composite particles can be adjusted by adjusting the mixing conditions of the monomer mixture and the aqueous medium, the addition amount of the other suspension stabilizer or the surfactant, the stirring conditions of the stirrer, the dispersion conditions, and the like.

In the method for producing a composite particle, in the presence of water-soluble cellulose-based cerium oxide particles adsorbed on the surface, the polymerizable monomer is subjected to aqueous suspension polymerization, and thus the water-soluble fiber adsorbed on the surface of the cerium oxide particle The action of the species allows the cerium oxide particles to adhere firmly to the surface of the polymer particles. Therefore, composite particles in which the cerium oxide particles are hard to fall off from the surface of the polymer particles can be obtained.

[composite particles]

According to the method for producing a composite particle described above, the composite particles of the present invention having the cerium oxide particles adhered to the surface of the polymer particles (polymer of the polymerizable monomer) can be obtained, for example, the TEM image of FIG. 1 and FIG. At least a part of the above polymer particles shown by a transmission electron microscope) contains a plurality of the above-mentioned cerium oxide particles (FIG. 1) And the composite particles coated with the layers of the black portion in FIG. 2 .

Specifically, the composite particles of the present invention include polymer particles, cerium oxide particles adhering to the surface of the polymer particles, and water-soluble cellulose.

In the composite particles of the present invention, the cerium oxide particles may adhere to the surface of the polymer particles via the water-soluble cellulose, or may directly adhere to the surface of the polymer particles. In other words, in the composite particles of the present invention, the water-soluble cellulose may be attached to both the cerium oxide particles and the polymer particles, or may be attached only to the cerium oxide particles and the polymer. On one of the particles.

Further, in the composite particles of the present invention, the amount of the cerium oxide particles deposited on the surface of the polymer particles is not particularly limited, and it is preferred that the composite particles have a surface area per unit surface of 0.010 g/m ² to 0.10 g/ Within the range of m ² . Per unit surface area applied amount of the silicon dioxide particles the surface of the polymer particles if the above-described composite particles was ^{0.010g / m 2 ~ 0.10g / m} 2, silicon dioxide particles can be sufficiently obtained so that the polymer particles adhere to The characteristic characteristics of the composite particles formed above. In addition, in the composite particles, the adhesion amount (g/m ² ) of the cerium oxide particles on the surface of the polymer particles can be, for example, the [method of calculating the amount of adhesion] described in the section of the examples to be described later. Find out.

In the composite particles of the present invention described above, since the cerium oxide particles are firmly adhered to the surface of the polymer particles by containing the water-soluble cellulose, it is difficult for the cerium oxide particles to fall off from the surface of the polymer particles.

[external agent]

The composite particles of the present invention can be used as an additive for improving the feeling of use such as slidability or an additive for making the skin defects such as pores, spots, and wrinkles less noticeable by the light diffusion effect. In the agent. The external preparation of the present invention comprises the composite particles of the present invention.

The content of the composite particles in the external preparation of the present invention can be appropriately set depending on the kind of the external preparation, and is preferably in the range of 1% by weight to 80% by weight, more preferably 3% by weight to 70% by weight. . When the content of the composite particles relative to the total amount of the external preparation is less than 1% by weight, there is a case where a clear effect due to the inclusion of the composite particles is not confirmed. In addition, when the content of the composite particles exceeds 80% by weight, there is a case where a remarkable effect consistent with an increase in the content cannot be confirmed, which is not preferable in terms of production cost.

The external preparation of the present invention can be used, for example, as an external pharmaceutical or cosmetic material. The externally-administered pharmaceutical product is not particularly limited as long as it is suitable for the skin, and specific examples thereof include milk fat, ointment, and emulsion. Examples of the cosmetic material include cosmetics for washing such as soap, shower gel, facial cleanser, scrub cleanser, and toothpaste; powders, face powders (powder powder, powder cake, etc.), foundations (powder foundation, liquid foundation, Emulsifying foundation, etc.), lipstick, lipstick, blush, eyebrow makeup (eye shadow, eyeliner, mascara, etc.), nail makeup and other make-up materials; pre-shave lotion, body lotion and other lotions; talcum powder, Skin lotion such as baby talcum powder; skin lotion such as lotion, cream, lotion (cosmetic lotion), antiperspirant (liquid antiperspirant, solid shape antiperspirant, creamy antiperspirant, etc.), mask (puck ), shampoo cosmetics, hair dye materials, hair styling materials, aromatic cosmetics, bath agents, sunscreen products, tanning Products, shaving cream, etc.

The composite particles to be formulated in the external preparation of the present invention may be composite particles treated with a surface treatment agent such as an oil agent, an anthrone compound or a fluorine compound, or an organic powder or an inorganic powder.

The oil agent may be any one of the users of the usual external preparations, and examples thereof include hydrocarbon oils such as liquid paraffin, scwaran, petrolatum, and paraffin; lauric acid, nutmeg, and palm. Acid, stearic acid, oleic acid, behenic acid, undecylenic acid, oxystearic acid, linoleic acid, lanolin fatty acid, synthetic fatty acid and other higher fatty acids; tricaprylin, propylene glycol diacetate, 2 - ester oils such as cetyl ethylhexanoate and isocetyl stearate; waxes such as beeswax, cetyl, lanolin, carnauba wax, and canola wax; linseed oil, cottonseed oil, alfalfa Oils such as sesame oil, egg butter, and coconut oil; metal soaps such as zinc stearate and zinc laurate; and higher alcohols such as cetyl alcohol, stearyl alcohol, and oleyl alcohol. Further, the method of treating the composite particles with the oil agent is not particularly limited, and for example, a dry method in which an oil agent is added to the composite particles and stirred by a mixer or the like to apply an oil agent can be used; The oil agent is heated and dissolved in a suitable solvent such as ethanol, propanol, ethyl acetate or hexane, and the composite particles are added thereto to carry out mixing and stirring, and then the solvent is removed under reduced pressure or heated to remove the oil. Wet method, etc.

The above-mentioned anthrone compound may be any one which is usually used in an external preparation, and examples thereof include dimethyl polyoxyalkylene, methyl hydrogenated polyoxyalkylene, and methylphenyl polyoxyalkylene. An acryl fluorenone-based graft polymer, an organic fluorenone resin partially crosslinked organopolyoxyalkylene polymer, and the like. Anthrone compound pair The method of treating the composite particles is not particularly limited, and for example, the above dry method or wet method can be used. Further, it is also possible to carry out an enamel treatment as needed, or in the case of a reactive anthrone compound, a reaction catalyst or the like is preferably added.

The fluorine compound may be any one which is usually formulated in an external preparation, and examples thereof include an ester containing a perfluoroalkyl group, a perfluoroalkyl decane, a perfluoropolyether, a polymer having a perfluoro group, and the like. . The method of treating the composite particles by the fluorine compound is also not particularly limited, and for example, the above dry method or wet method can be used. Further, the sintering treatment may be carried out as needed, and in the case of a reactive fluorine compound, a reaction catalyst or the like may be appropriately added.

Examples of the above organic powder include natural gum compounds such as gum arabic, tragacanth, guar gum, locust bean gum, karaya gum, irish moss, medlar seed, gelatin, shellac, rosin, and casein. Semi-synthetic polymer compound such as sodium carboxymethyl cellulose, hydroxyethyl cellulose, methyl cellulose, ethyl cellulose, sodium alginate, ester gum, nitrocellulose, hydroxypropyl cellulose, crystalline cellulose Polyvinyl alcohol, polyvinylpyrrolidone, sodium polyacrylate, carboxyvinyl polymer, polyvinyl methyl ether, polyamide resin, fluorenone oil, nylon particles, polymethyl methacrylate particles, cross-linked poly Resin particles such as styrene particles, anthrone particles, urethane particles, polyethylene particles, and fluororesin particles. Further, examples of the inorganic powder include iron oxide, ultramarine blue, Prussian blue, chromium oxide, chromium hydroxide, carbon black, manganese violet, titanium oxide, zinc oxide, talc, kaolin, mica, calcium carbonate, and magnesium carbonate. , aluminum citrate, barium strontium citrate, calcium citrate, magnesium citrate, cerium oxide, zeolite, barium sulfate, calcined calcium sulfate (calcined gypsum), calcium phosphate, hydroxyapatite, ceramic powder, and the like. and, These organic powders or inorganic powders may also be surface-treated in advance. The surface treatment method can utilize the well-known surface treatment techniques as described above.

Further, in the external preparation of the present invention, the main ingredient or the additive which is usually used may be blended as needed within the range which does not impair the effects of the present invention. Examples of such a main agent or an additive include water, a lower alcohol (an alcohol having a carbon number of 5 or less), fats and oils, a hydrocarbon, a higher fatty acid, a higher alcohol, a sterol, a fatty acid ester, a metal soap, a humectant, and the like. Surfactant, polymer compound, raw material for colored materials, perfume, clay minerals, antiseptic/bactericide, anti-inflammatory drug, antioxidant, ultraviolet absorber, organic-inorganic composite particle, pH adjuster (triethanolamine) Etc.), special blending additives, active ingredients of medical products.

Specific examples of the fats and oils and waxes include avocado oil, almond oil, olive oil, cocoa butter, butter, sesame oil, wheat germ oil, safflower oil, shea butter, turtle oil, and camellia. Oil, peach kernel oil, castor oil, grape oil, Australian walnut oil, oyster sauce, egg butter, wood wax, coconut oil, rosehip oil, hardened oil, ketone oil, Atlantic spine fish oil, carnauba wax, Candelilla Wax, whale wax, jojoba oil, montan wax, beeswax, lanolin, etc.

Specific examples of the above hydrocarbons include liquid paraffin, petrolatum, paraffin wax, pure ceresin, micro crystalline wax, and squalane.

Specific examples of the above higher fatty acid include lauric acid, myristic acid, palmitic acid, stearic acid, oleic acid, behenic acid, undecylenic acid, oxystearic acid, linoleic acid, lanolin fatty acid, and synthetic fatty acid. A fatty acid having a carbon number of 11 or more.

Specific examples of the above higher alcohols include lauryl alcohol, cetyl alcohol, and cetyl stearin. Alcohol, stearyl alcohol, oleyl alcohol, behenyl alcohol, lanolin alcohol, hydrogenated lanolin alcohol, cetyl alcohol, stearyl alcohol, isostearyl alcohol, jojoba alcohol, mercaptotetradecyl alcohol, etc. The above alcohol.

Specific examples of the above sterols include cholesterol, dihydrocholesterol, and plant cholesterol.

Specific examples of the fatty acid esters include linoleic acid esters such as linoleic acid ethyl ester; lanolin fatty acid esters such as lanolin fatty acid isopropyl ester; lauric acid esters such as hexyl laurate; and isopropyl myristate and meat. Myristate myristate, cetyl myristate, octadecyl myristate, octyl dodecyl myristate, etc.; oleic acid oleate, octyl dodecyl oleate Oleic acid ester such as ester; dimethyl octanoate such as cetyl dimethyl octanoate; isooctanoate such as cetyl isooctanoate (cetyl 2-ethylhexanoate); decyl palmitate Palmitate; glyceryl trimyristate, glyceryl tris(octyl decanoate), propylene glycol dioleate, glyceryl triisostearate, glyceryl triisooctanoate, cetyl lactate, myristyl lactate A cyclic alcohol fatty acid ester such as diisostearyl malate, cholesteryl isostearate or cholesteryl 12-hydroxystearate.

Specific examples of the above metal soaps include zinc laurate, zinc myristate, magnesium myristate, zinc palmitate, zinc stearate, aluminum stearate, calcium stearate, magnesium stearate, and undecene. Zinc acid and the like.

Specific examples of the above humectant include glycerin, propylene glycol, 1,3-butylene glycol, polyethylene glycol, sodium dl-pyrrolidone, sodium lactate, sorbitol, sodium hyaluronate, polyglycerin, xylitol, and maltitol. Wait.

Specific examples of the above surfactants include anionic surfactants such as higher fatty acid soaps, higher alcohol sulfates, N-mercapto glutamates, and phosphate esters; amines; a cationic surfactant such as a salt or a quaternary ammonium salt; an amphoteric surfactant such as a betaine type, an amino acid type, an imidazoline type, or a lecithin; a fatty acid monoglyceride, a polyethylene glycol, a propylene glycol fatty acid ester, and a sorbent A nonionic surfactant such as a sugar anhydride fatty acid ester (for example, sorbitan stearate), a fatty acid sucrose ester, a polyglycerin fatty acid ester, or an ethylene oxide condensate.

Specific examples of the polymer compound include natural gum compounds such as gum arabic, tragacanth, guar gum, locust bean gum, karaya gum, carrageen, medlar seed, gelatin, shellac, rosin, and casein; Semi-synthetic polymer compound such as sodium carboxymethyl cellulose, hydroxyethyl cellulose, methyl cellulose, ethyl cellulose, sodium alginate, ester gum, nitrocellulose, hydroxypropyl cellulose, crystalline cellulose; Polyvinyl alcohol, polyvinylpyrrolidone, sodium polyacrylate, carboxyvinyl polymer, polyvinyl methyl ether, polyamide resin, fluorenone oil, nylon particles, poly(meth) acrylate particles (eg polymethyl A synthetic polymer compound such as a polyester acrylate particle or the like, a polystyrene particle, an anthrone particle, a urethane particle, or a resin particle such as a polyethylene particle. Further, in the specification of the present application, "(meth)acrylic group" means a methacrylic group or an acrylic group.

Specific examples of the raw material of the colored material include iron oxide (red iron oxide, yellow iron oxide, black iron oxide, etc.), ultramarine blue, Prussian blue, chromium oxide, chromium hydroxide, carbon black, manganese violet, titanium oxide, zinc oxide, Talc, kaolin, calcium carbonate, magnesium carbonate, mica, aluminum citrate, barium strontium citrate, calcium citrate, magnesium citrate, cerium oxide, zeolite, barium sulfate, calcined calcium sulfate (calcined gypsum), calcium phosphate, hydroxyphosphorus Inorganic pigments such as limestone and ceramic powder, azo, nitro, nitroso, dibenzopyran, A tar pigment such as quinoline, quinolinol, indigo, triphenylmethane, phthalocyanine or anthraquinone.

Further, the powder raw material such as the powder material of the polymer compound or the raw material of the colored material may be used as a surface treatment in advance. The surface treatment method can be carried out by a known surface treatment technique, and for example, treatment with an oil agent such as a hydrocarbon oil, an ester oil, or a lanolin can be used, and dimethyl polysiloxane, methyl hydrogenated polyoxyalkylene, and methylbenzene can be used. An anthrone treatment such as a polyoxyalkylene group is treated with a fluorine compound such as a perfluoroalkyl group-containing ester, a perfluoroalkyl decane, a perfluoropolyether, or a perfluoroalkyl group-containing polymer, and a 3-methyl group is used. Treatment with a decane coupling agent such as acryloxypropyltrimethoxydecane or 3-glycidoxypropyltrimethoxydecane, using isopropyl triisostearate titanate, isopropyl tris(II) Treatment with a titanium coupling agent such as octyl pyrophosphate) titanate, treatment with a metal soap, treatment with an amino acid such as mercapto glutamic acid, treatment with lecithin such as hydrogenated egg yolk lecithin, collagen treatment, polyethylene Treatment methods such as treatment, moisturizing treatment, inorganic compound treatment, and mechanochemical treatment.

Specific examples of the clay minerals include components having several functions such as specific pigments and adsorbents, such as talc, mica, sericite, titanium sericite (sericite coated with titanium oxide), muscovite, and van der Waals. VEEGUM (registered trademark) manufactured by Vanderbilt Co., Ltd., etc.

Specific examples of the above-mentioned perfume include anisaldehyde, benzyl acetate, vanillyl alcohol and the like. Specific examples of the antiseptic/bactericidal agent include methylparaben, ethylparaben, propylparaben, benzalkonium chloride, and benzylammonium. Specific examples of the above antioxidants include dibutylhydroxytoluene, butylhydroxyanisole, and gallnuts. Acid propyl ester, tocopherol, and the like. Specific examples of the anti-inflammatory agent include ε-aminohexanoic acid, glycyrrhizic acid, dipotassium glycyrrhizinate, β-glycyrrhetinic acid, chlorinated lysozyme, guaiazulene, and hydrocortisone. These compounds may be used singly or in combination of two or more. Specific examples of the ultraviolet absorber include inorganic fine particles such as fine particle titanium oxide, fine particle zinc oxide, fine particle cerium oxide, fine particle iron oxide, and fine particle zirconia, benzoic acid, p-aminobenzoic acid, and ortho-aminobenzoic acid. An organic absorbent such as a salicylic acid, a cinnamic acid, a benzophenone or a benzoylmethane.

Specific examples of the specific preparation additive include estradiol, estrone, ethinyl estradiol, cortisone, hydrocortisone, and prednisone, vitamin A, vitamin B, vitamin C, vitamin E, and the like. Vitamins, citric acid, tartaric acid, lactic acid, aluminum chloride, potassium aluminum sulfate, allantoin chlorohydroxy aluminum, zinc phenolsulfonate, zinc sulfate and other skin astringents, cantharidin, capsicum, ginger, and medicine Extract, garlic extract, hinokitiol, caprochloroammonium, pentaglyceride, vitamin E, estrogen, photoreceptor and other hair growth promoter, phosphoric acid-L-anti-barium citrate, citric acid Such as whitening agent (whitening agent) and the like.

The above-mentioned external preparation of the present invention contains the composite particles of the present invention and thus has good slidability. Further, when the external preparation contains an aqueous solvent, good dispersibility of the composite particles is obtained due to the hydrophilicity of the ceria particles adhered to the surface of the polymer particles.

[Coating agent]

The composite particles of the invention can be used as a coating softening agent, coating It is contained in a coating agent with a matting agent, a light diffusing agent, etc. The coating agent of the present invention comprises the composite particles of the present invention.

The above coating agent may optionally contain a binder resin. As the binder resin, a resin which is soluble in an organic solvent or water or an emulsion type water-based resin which can be dispersed in water can be used, and a known binder resin can be used arbitrarily. For example, the brand name "Dianal (registered trademark) LR-102" or "Dianal (registered trademark) BR-106" manufactured by Mitsubishi Rayon Co., Ltd., or the product name of Dairi Seiki Co., Ltd. Acrylic resin such as Medium VM; alkyd resin; polyester resin; polyurethane resin; chlorinated polyolefin resin; amorphous polyolefin resin; These binder resins can be suitably selected depending on the adhesion of the coating agent to the applied substrate, the use environment, and the like.

The amount of the composite particles to be blended can be appropriately adjusted depending on the film thickness of the coating film formed of the coating agent containing the binder resin, the average particle diameter of the composite particles, the coating method, the use, and the like, and is preferably relative to the binder resin. 100 parts by weight is in the range of 1 part by weight to 300 parts by weight, more preferably 5 parts by weight to 100 parts by weight. When the amount of the composite particles is less than 1 part by weight based on 100 parts by weight of the binder resin, the matting effect may not be sufficiently obtained. In addition, when the amount of the composite particles is more than 300 parts by weight based on 100 parts by weight of the binder resin, the viscosity of the coating agent is excessively increased, and thus the composite particles are poorly dispersed. As a result, the following results occur. When the appearance of the surface of the coating film is poor, microcracks are formed on the surface of the coating film obtained by applying the coating agent, or spotty or the like is formed on the surface of the obtained coating film.

The above coating agent contains a medium as needed. The above medium is preferably a solvent which can dissolve the binder resin or a dispersion medium which can disperse the binder resin. An aqueous medium and an oily medium can be used arbitrarily in the dispersion medium or solvent. Examples of the oily medium include hydrocarbon solvents such as toluene, xylene, and cyclohexane; ketone solvents such as methyl ethyl ketone and methyl isobutyl ketone; ester solvents such as ethyl acetate and butyl acetate; and dioxane. An ether solvent such as ethylene glycol diethyl ether or ethylene glycol monobutyl ether. Examples of the aqueous medium include water, alcohols (for example, isopropyl alcohol), and the like. These media may be used alone or in combination of two or more. The content of the medium in the coating agent is usually in the range of 20% by weight to 60% by weight based on the total amount of the coating agent.

Further, the coating agent may further contain a curing agent, a coloring agent (body pigment, coloring pigment, metallic pigment, mica powder pigment, dye, etc.), an antistatic agent, a leveling agent, a fluidity adjusting agent, an ultraviolet absorber, Other additives such as light stabilizers.

The substrate to be coated of the coating agent is not particularly limited, and a substrate corresponding to the use can be used.

For example, in optical applications, a glass substrate, a transparent substrate containing a transparent substrate resin, or the like is used as the substrate to be coated. By using a transparent substrate as a substrate to be coated, a coating agent (a coating agent for light diffusion) containing no coloring agent is applied onto a transparent substrate to form a transparent coating film, and a light diffusion film or a film can be produced. An optical film such as a glare film. In this case, the composite particles function as a light diffusing agent.

Further, by using paper as a substrate to be coated, a coating agent (coating agent for paper) containing no coloring agent is applied to form a transparent coating film, and a matte paper can be produced.

The coating method of the coating agent is not particularly limited, and a known one can be used arbitrarily. law. Examples of the coating method include a comma direct coating method, a spin coating method, a spray coating method, a roll coating method, a dipping method, a knife coating method, a curtain coating method, and a lamination method. The coating agent is adjusted for viscosity as needed, and may be diluted by adding a diluent. Examples of the diluent include hydrocarbon solvents such as toluene and xylene; ketone solvents such as methyl ethyl ketone and methyl isobutyl ketone; ester solvents such as ethyl acetate and butyl acetate; and dioxane and ethylene glycol. An ether solvent such as diethyl ether; water; an alcohol solvent. These diluents may be used singly or in combination of two or more. In the case of producing an optical film, the coating method preferably uses a method in which irregularities derived from composite particles are formed on the surface of the coating film.

Since the coating agent of the present invention as described above contains the composite particles of the present invention, it is possible to impart light diffusibility to the coating film formed by the coating agent. Further, in the coating agent, the hardness of the composite particles is ensured by the cerium oxide particles adhering to the surface of the polymer particles, and therefore the scratch resistance of the coating film formed by the coating agent can be expected to be improved. Further, in the case where the coating agent contains an aqueous solvent, good dispersibility of the composite particles is obtained due to the hydrophilicity of the ceria particles adhered to the surface of the polymer particles.

[Optical film]

The optical film of the present invention is obtained by applying the coating agent of the present invention onto a film-form substrate. Specific examples of the optical film include a light diffusion film or an anti-glare film.

Specific examples of the substrate of the optical film include a glass substrate or a transparent substrate containing a transparent substrate resin.

Examples of the transparent base material resin include polymethyl methacrylate and the like. Ethylene resin, alkyl (meth)acrylate-styrene copolymer, polycarbonate, polyethylene terephthalate (hereinafter referred to as "PET"), polyester, polyethylene, polypropylene, polyphenylene Ethylene and the like. Among the transparent base materials, in the case where the transparent base resin requires excellent transparency, an acrylic resin, an alkyl (meth)acrylate-styrene copolymer, a polycarbonate, and a polyester are preferable. And polystyrene. These transparent base materials may be used alone or in combination of two or more.

Further, in the optical film, the thickness of the coating film obtained by applying the coating agent is preferably in the range of 5 μm to 100 μm.

[Resin composition]

The resin composition of the present invention comprises the composite particles of the present invention and a base resin. Since the resin composition of the present invention contains the composite particles of the present invention and has excellent light diffusibility, it can be used as a lighting cover (lighting diode for lighting (LED) illumination, illumination cover for fluorescent lighting, etc.), and light diffusion. A raw material of a light diffuser such as a sheet or a light diffusing plate.

The base resin is usually a thermoplastic resin different from the polymer component constituting the composite particles. Examples of the thermoplastic resin used as the base resin include an acrylic resin, an alkyl (meth)acrylate-styrene copolymer, polycarbonate, polyester, polyethylene, polypropylene, polystyrene, and the like. In the case where the substrate resin requires excellent transparency, among these thermoplastic resins, preferred are acrylic resin, alkyl (meth)acrylate-styrene copolymer, polycarbonate, polyester, and polystyrene. . These thermoplastic resins may be used alone or in combination of two or more.

The addition ratio of the composite particles to the base resin is preferably in the range of 0.1 part by weight to 70 parts by weight, more preferably 100 parts by weight of the base resin. It is in the range of 1 part by weight to 50 parts by weight. When the ratio of addition of the composite particles to the base resin is less than 0.1 part by weight based on 100 parts by weight of the base resin, it may be difficult to impart light diffusibility to the light diffuser. When the ratio of addition of the composite particles to the base resin is more than 70 parts by weight based on 100 parts by weight of the base resin, the light diffusing body is provided with light diffusing property, but the light diffusing body is transparent. The situation of low light.

The method for producing the resin composition is not particularly limited, and it can be produced by mixing the composite particles and the base resin by a conventionally known method such as a mechanical pulverization and mixing method. In the mechanical pulverization mixing method, for example, a resin composition can be produced by mixing and mixing a composite particle and a base resin by using a Henschel mixer, a V-type mixer, a tumbler mixer, a blender, a rocking mixer, or the like. Things.

[formed body]

The molded article of the present invention is obtained by molding the resin composition of the present invention. Specific examples of the molded article of the present invention include a light-emitting body such as a lighting cover (light-emitting diode (LED) illumination cover, a fluorescent lamp illumination cover, etc.), a light diffusion sheet, and a light diffusion plate.

For example, the composite particles are mixed with a base resin by a mixer, and kneaded by a melt kneader such as an extruder to obtain pellets containing a resin composition, and then the pellets are extrusion-molded or the pellets are melted. Injection molding is performed, whereby a molded body of an arbitrary shape can be obtained.

[Examples]

Hereinafter, the present invention will be specifically described by way of examples and comparative examples. The invention is not limited to the embodiments. First, each measurement method in the examples and comparative examples will be described.

[Method for Measuring Average Primary Particle Size of Ceria Particles]

The average primary particle diameter of the cerium oxide particles (specifically, the Z average particle diameter calculated by the cumulative analysis method) can be, for example, a particle size measuring device (manufactured by Malvern) using a dynamic light scattering method. Determined by Zetasizer Nano ZS").

As the measurement sample, a dispersion liquid obtained by dispersing the measured cerium oxide particles in ion-exchanged water can be used. Further, when the average primary particle diameter of the cerium oxide particles is less than 100 nm, the dispersion liquid is prepared so that the concentration of the cerium oxide particles is 1% by weight; the average primary particle diameter of the cerium oxide particles is assumed. In the case of 100 nm or more, the dispersion liquid was prepared so that the concentration of the cerium oxide particles was 0.1% by weight. In the measurement unit of the particle size measuring apparatus (Zetasizer Nano ZS) manufactured by the Malvern Co., Ltd., a polyethylene cell is provided, and the dispersion liquid is dispensed into the polyethylene tank. The Z average particle diameter of the cerium oxide particles.

The Z average particle diameter is a value obtained by analyzing the measurement data of a dynamic light scattering method such as a particle dispersion using a cumulative analysis method.

In the cumulative analysis method, the average value of the particle diameter and the Polydispersity Index (PDI) were obtained, and the average value of the particle diameter was defined as the Z average particle diameter. Strictly speaking, the operation of fitting the logarithmic fitting polynomial of the measured G1 correlation function is referred to as cumulative analysis, and the constant b in the following formula is referred to as second-order accumulation or Z-average diffusion coefficient.

LN(G1)=A+bt+ct ² +dt ³ +et ⁴ +...

The value obtained by converting the above-mentioned constant b into the particle diameter using the viscosity of the above dispersion liquid and a plurality of device constants is a Z average particle diameter.

[Method for Measuring Adsorption Amount of Water-Soluble Cellulose on Ceria Particles]

With respect to Examples 1 to 3 to be described later, the dispersion medium containing the cerium oxide particles adsorbed with the soluble cellulose obtained in the production step of the composite particles was used, and the water solubility per gram of the cerium oxide particles was measured by the following method. The amount of adsorption of cellulose (g).

0.25 g of a dispersion medium containing cerium oxide particles adsorbed with water-soluble cellulose was added to 1 g of ion-exchanged water to be diluted, and then a centrifugal separator (Hitachi high-speed cooling centrifuge HIMAC manufactured by Hitachi High-Technologies Co., Ltd.) was used. CR22GII"), centrifuged for 30 minutes by 25000G. 1 ml of a 5% aqueous phenol solution was added to 1 ml of the obtained supernatant, and 5 ml of concentrated sulfuric acid was further added thereto, and the mixture was allowed to stand for 10 minutes, and further allowed to stand in an aqueous solution at 25 ° C for 10 minutes to obtain a measurement sample. For the above-mentioned measurement sample, the absorbance at 485 nm was measured by an ultraviolet-visible spectrophotometer ("UV-visible spectrophotometer UV-2450" manufactured by Shimadzu Corporation), and a calibration curve (indicating absorbance and water-soluble cellulose) was used. The concentration (g/l) of the water-soluble cellulose in the supernatant was determined by the curve of the relationship of the concentration.

In addition, the calibration curve can be created by the method shown below. In other words, 0.01 g, 0.05 g, and 0.1 g of water-soluble cellulose used in the preparation of a dispersion medium were added to 100 g of ion-exchanged water to prepare three kinds of aqueous solutions having different concentrations. 0.25 g of each of the prepared aqueous solutions was diluted with 0.75 g of ion-exchanged water, and the absorbance was measured for each of the diluted aqueous solutions. Then, a calibration curve of a primary curve is prepared by plotting the weight and absorbance of the water-soluble cellulose in the aqueous solution.

Then, the amount (g) of the water-soluble cellulose per gram of the cerium oxide particles was determined by the following formula.

D=(W _H -C×V)÷W _S

D: adsorption amount of water-soluble cellulose per 1 g of cerium oxide particles (g)

C: concentration of water-soluble cellulose in the above supernatant (g/l)

W _H : weight of water-soluble cellulose used in the production of composite particles (g)

W _S : weight of cerium oxide particles used in the production of composite particles (g)

V: volume of the aqueous medium used in the preparation of the above dispersion medium in the production of composite particles (1)

[Method for Measuring Volume Average Particle Size]

The volume average particle diameter of the particles (composite particles or polymer particles) obtained in the examples and comparative examples described later can be measured by a Coulter particle counter MULTISIZER III (manufactured by Beckman Coulter Co., Ltd.). Measured by the device). In accordance with the embodiment was measured using Beckman Coulter Incorporated Company Multisizer ^TM 3 User Manual corrected aperture.

In addition, as for the selection of the pore diameter to be used for the measurement, it is preferable to select 50 μm when the volume average particle diameter of the measured particles (composite particles or polymer particles) is 1 μm or more and 10 μm or less. Pore size of the size; in the case where the assumed volume average particle diameter of the measured particles (composite particles or polymer particles) is more than 10 μm and 30 μm or less, a pore diameter having a size of 100 μm is selected; in the particle (composite particle or polymerization) In the case where the volume average particle diameter of the object particles is larger than 30 μm and 90 μm or less, a pore diameter having a size of 280 μm is selected; the volume average particle diameter of the particles (composite particles or polymer particles) is larger than 90 μm and 150 μm. In the following cases, an aperture or the like having a size of 400 μm is selected. When the volume average particle diameter after the measurement differs from the assumed volume average particle diameter, the measurement is performed by changing the pore size to an appropriate size.

Further, in the case of selecting an aperture having a size of 50 μm, Current is set to -800, Gain is set to 4, and in the case of selecting an aperture having a size of 100 μm, Current is set. For -1600, Gain is set to 2; in the case of selecting an aperture having a size of 280 μm and 400 μm, Current is set to -3200 and Gain is set to 1.

The sample for measurement was used as follows: a contact mixer (manufactured by Daiwa Scientific Co., Ltd., "TOUCHMIXER MT-31") and an ultrasonic cleaner (manufactured by VELVO-CLEAR Co., Ltd., "ULTRASONIC CLEANER") VS-150") 0.1 g of the particles (composite particles or polymer particles) to be measured was dispersed in 10 ml of a 0.1% by weight aqueous solution of a nonionic surfactant to prepare a dispersion. In the measurement unit of the Coulter Particle Counter MULTISIZER III, a beaker filled with ISOTON (registered trademark) II (manufactured by Beckman Coulter Co., Ltd.; electrolyte for measurement) is placed, and the mixture is slowly stirred while being placed in the beaker. The above dispersion was measured after the reading of the concentration meter of the Kurt particle counter MULTISIZER III body image was equal to 5% to 10%. During the measurement, the inside of the beaker was gradually stirred so as not to enter the bubble, and the measurement was completed at the time of measuring 100,000 particles. The volume average particle diameter of the particles (composite particles or polymer particles) is the arithmetic mean of the volume distribution of the volume basis of 100,000 particles.

[Method for determination of strong heat residual components]

After 1.0 g of the measurement target particles (composite particles or polymer particles) was measured, the measured particles were burned in an electric furnace at 550 ° C for 30 minutes, and the weight (g) of the residual residue was measured. Then, the weight (g) of the measured residue was divided by the weight (1.0 g) of the particles before the measurement, and the percentage of the residue (% by weight) was obtained.

[Method for measuring specific surface area]

The measurement target particles (composite particles or polymer particles) were measured to be 0.25 g. The measured particles were mixed with 0.025 g of sodium dodecylbenzenesulfonate and 50 g of pure water, and the mixture was stirred by ultrasonic waves for 10 minutes to disperse the resin particles as a measurement sample. Then, using a laser diffraction type particle size distribution measuring apparatus (manufactured by Malvern Instruments Ltd., "Mastersizer 2000"), the specific surface area of the particles in the measurement sample was measured under the following measurement conditions.

<Measurement conditions>

Dispersing medium: water

Analysis mode: universal

Particle refractive index: 1.50

Dispersion medium refractive index: 1.33

[Method for calculating the amount of cerium oxide particles added]

The weight of the use of the cerium oxide particles in the production of the composite particles, the weight of the polymerizable vinyl monomer, and the specific surface area of the particles (composite particles or polymer particles) measured by the above-described method for measuring the specific surface area are used. The addition amount (g/m ² ) of the cerium oxide particles per unit surface area of the particles obtained in the above production was determined by the following calculation formula.

Add amount = (W _S ÷ W _m ) ÷ X

W _S : weight of used cerium oxide particles in the production of composite particles (g)

W _m : weight of the polymerizable vinyl monomer used in the production of the composite particles (g)

X: specific surface area (m ² /g) of particles measured by the above-described method for measuring specific surface area

[Method for calculating the amount of ruthenium dioxide particles attached]

In the particles obtained in the examples and the comparative examples described later, the strong heat residual component and the amount of the cerium oxide particles in the particles are substantially the same. Therefore, the strong heat residual component measured by the measurement method of the strong heat residual component is used. The specific surface area of the particles measured by the above-described method for measuring the specific surface area was determined by the following formula to determine the adhesion amount (g/m ² ) of the ceria particles per unit surface area of the particles obtained in the above production.

Adhesion = (A÷100)÷X

A: Strong heat residual component (% by weight) measured by a method for measuring a strong residual component

X: specific surface area (m ² /g) of particles measured by the above-described method for measuring specific surface area

Further, in the method for measuring the strong heat residual component, the particles are burned in an electric furnace at 550 ° C for 30 minutes, and the remaining residue contains components other than the cerium oxide particles, and the method of measuring the strong heat residual component is used. When the measured strong heat residual component is different from the amount of the cerium oxide particles in the particles, the adhesion amount of the cerium oxide particles per unit surface area of the particles obtained in the above production can be obtained by the following formula (g/ m ² ). In addition, whether or not the residue contains cerium oxide particles and the amount of cerium oxide particles contained in the residue can be determined by a known method such as elemental analysis.

Adhesion amount = {(A÷100) × (B÷100)}÷X

A: Strong heat residual component measured by a method for measuring a strong residual component (heavy the amount%)

B: content rate (% by weight) of cerium oxide particles in the above residue

X: specific surface area (m ² /g) of particles measured by the above-described method for measuring specific surface area

[Example 1: Production Example of Composite Particles]

150 g of water as an aqueous medium and Snowtex (registered trademark) O-40 (hereinafter referred to as "ST-O-40", a colloid manufactured by Nissan Chemical Industries Co., Ltd.) as a cerium oxide particle in a polymerization vessel equipped with a stirring device Cerium oxide, an average primary particle diameter of 25 nm, a solid content of 40% by weight, 1.1 g (SiO ₂ purity: 0.44 g), and METOLOSE (registered trademark) 65SH-400 as a water-soluble cellulose (abbreviated as "HPMC (") 65SH-400), hydroxypropylmethylcellulose manufactured by Shin-Etsu Chemical Co., Ltd., and a cloud point of 65 ° C), 0.09 g, and mixed at a temperature of 60 ° C for 24 hours. Thereby, a dispersion medium containing cerium oxide particles adsorbed with water-soluble cellulose is obtained. The amount of adsorption of the water-soluble cellulose to the cerium oxide particles was measured using the dispersion medium, and as a result, 0.18 g of water-soluble cellulose was adsorbed to the cerium oxide particles per 1 g of the cerium oxide particles.

Further, 50 g of methyl methacrylate (MMA) and 2.5 g of ethylene glycol dimethacrylate (EGDMA) as a polymerizable vinyl monomer, 2,2'-azobis (2) as a polymerization initiator 0.5 g of 4-dimethylvaleronitrile (ADVN) was uniformly mixed and dissolved to prepare a monomer mixture containing a polymerization initiator.

The monomer mixture containing the polymerization initiator is added to the above dispersion medium in the above polymerization vessel, and is produced by a homomixer (SMT). HIGH-FLEX DISPERSER HG-2) was stirred at 4500 rpm for about 3 minutes to finely disperse the above monomer mixture in the above dispersion medium.

Thereafter, stirring was continued at a stirring speed of 70 rpm, and after the temperature of the dispersion medium to which the above monomer mixture was added was 55 ° C, suspension polymerization was carried out for 6 hours.

Next, the reaction liquid in the polymerization vessel was cooled to room temperature while stirring. Next, the reaction liquid was suction-filtered using a qualitative filter paper 101 ("Toyo qualitative filter paper" manufactured by Advantec Toyo Co., Ltd.), washed with ion-exchanged water, and then deliquored. Thereafter, it was dried in an oven at 90 ° C for a day and night to obtain composite particles.

The cross section of the obtained composite particles was confirmed by a transmission electron microscope (TEM). As a result, as shown in FIGS. 1 and 2, the composite particles contained polymer particles and adhered to the polymer particles. The cerium oxide particles. Further, it was confirmed that a layer containing cerium oxide particles was formed on the surface of the polymer particles in the composite particles.

Further, the obtained composite particles had a volume average particle diameter of 20.2 μm, a specific surface area of 0.29 m ² /g, and a strong heat residual component of 0.60% by weight. Further, the amount of the cerium oxide particles added was 0.029 g/m ² , and the amount of the cerium oxide particles in the obtained composite particles was 0.021 g/m ² per unit surface area of the composite particles.

[Example 2: Production Example of Composite Particles]

As water-soluble cellulose, METOLOSE (registered trademark) 65SH-4000 (referred to as "HPMC (65SH-4000)", Shin-Etsu Chemical Industry Co., Ltd. The same procedure as in Example 1 was carried out except that hydroxypropylmethylcellulose manufactured by the company and a cloud point of 65 ° C) of 0.09 g were used instead of METOLOSE (registered trademark) 65SH-400 (HPMC (65SH-400)) of 0.09 g. And get the composite particles.

In the dispersion medium containing the water-soluble cellulose-based cerium oxide particles obtained in the production step of the second embodiment, the adsorption amount of the water-soluble cellulose to the cerium oxide particles is 1 g of cerium oxide particles per gram of the cerium oxide particles. It is 0.17g. Further, the obtained composite particles had a volume average particle diameter of 24.6 μm, a specific surface area of 0.24 m ² /g, and a strong heat residual component of 0.70% by weight. Further, the amount of the cerium oxide particles added was 0.035 g/m ² , and the amount of the cerium oxide particles in the obtained composite particles was 0.029 g/m ² .

[Example 3: Production Example of Composite Particles]

As a water-soluble cellulose, METOLOSE (registered trademark) 65SH-50 (abbreviated as "HPMC (65SH-50)", hydroxypropyl methylcellulose manufactured by Shin-Etsu Chemical Co., Ltd., and a cloud point of 65 ° C) is used. 0.09g instead of METOLOSE (registered trademark) 65SH-400 (HPMC (65SH-400)) 0.09g, in the preparation of the monomer mixture, KAYAMER (registered trademark) PM-21 as a polymerizable phosphate monomer is further used (abbreviation) The composite particles were obtained in the same manner as in Example 1 except that 0.05 g of "PM-21" and manufactured by Nippon Chemical Co., Ltd. were used.

In the dispersion medium containing the water-soluble cellulose-based cerium oxide particles obtained in the production step of the third embodiment, the adsorption amount of the water-soluble cellulose relative to the cerium oxide particles is 1 g of cerium oxide particles per gram. It is 0.16g. Further, the obtained composite particles had a volume average particle diameter of 21.8 μm, a specific surface area of 0.28 m ² /g, and a strong heat residual component of 0.60% by weight. Further, the amount of the cerium oxide particles added was 0.030 g/m ² , and the amount of the cerium oxide particles in the obtained composite particles was 0.021 g/m ² .

[Example 4: Production Example of Composite Particles]

As the polymerizable vinyl monomer, 50 g of styrene (St) and 2.5 g of ethylene glycol dimethacrylate (EGDMA) were used instead of methyl methacrylate (MMA) 50 g and ethylene glycol dimethacrylate ( The composite particles were obtained in the same manner as in Example 1 except that 2.5 g of EGDMA was used.

The obtained composite particles had a volume average particle diameter of 20 μm, a specific surface area of 0.29 m ² /g, and a strong heat residual component of 0.80% by weight. Further, the amount of the cerium oxide particles added was 0.029 g/m ² , and the amount of the cerium oxide particles in the obtained composite particles was 0.028 g/m ² .

[Example 5: Production Example of Composite Particles]

As the cerium oxide particles, Snowtex OXS (abbreviated as "ST-OXS", colloidal cerium oxide manufactured by Nissan Chemical Industries, Ltd., average primary particle diameter of 7.8 nm, solid content of 15% by weight) of 2.3 g (SiO) was used. ₂ purity 0.35g) instead of Snowtex (registered trademark) O-40 (ST-O -40) 1.1g (SiO 2 purity 0.44g), except in the same manner as in Example 1 to obtain composite particles.

The obtained composite particles had a volume average particle diameter of 20.5 μm, a specific surface area of 0.29 m ² /g, and a strong heat residual component of 0.33% by weight. Further, the amount of the cerium oxide particles added was 0.023 g/m ² , and the amount of the cerium oxide particles in the obtained composite particles was 0.011 g/m ² .

[Example 6: Production Example of Composite Particles]

As the cerium oxide particles, Snowtex OZL-35 (abbreviated as "ST-OZL-35", colloidal cerium oxide manufactured by Nissan Chemical Industries, Ltd., average primary particle diameter of 85 nm, solid content of 35 % by weight) was used. A composite particle was obtained in the same manner as in Example 1 except that g (SiO ₂ purity: 1.5 g) was used instead of Snowtex (registered trademark) O-40 (ST-O-40) 1.1 g (SiO ₂ purity: 0.44 g). .

The obtained composite particles had a volume average particle diameter of 20.9 μm, a specific surface area of 0.29 m ² /g, and a strong heat residual component of 1.9% by weight. Further, the amount of the cerium oxide particles added was 0.10 g/m ² , and the amount of the cerium oxide particles in the obtained composite particles was 0.066 g/m ² .

[Example 7: Production Example of Composite Particles]

As the cerium oxide particles, Snowtex PS-MO (referred to as "ST-PS-MO", colloidal cerium oxide manufactured by Nissan Chemical Industries, Ltd., and spherical particles having an average primary particle diameter of 21.5 nm are combined. In addition to the Snowtex (registered trademark) O-40 (ST-O-40) 1.1 g (the purity of SiO ₂ was 0.44 g), 2.53 g (solid content: 15% by weight) of 2.53 g (SiO ₂ purity: 0.38 g) was used. Example 1 was carried out in the same manner to obtain composite particles.

The obtained composite particles had a volume average particle diameter of 20.5 μm, a specific surface area of 0.29 m ² /g, and a strong heat residual component of 0.60% by weight. Further, the amount of the cerium oxide particles added was 0.025 g/m ² , and the amount of the cerium oxide particles in the obtained composite particles was 0.021 g/m ² .

[Example 8: Production Example of Composite Particles]

As a water-soluble cellulose, use NISSO HPC H (Japan Soda Co. has The hydroxypropyl cellulose produced by the company, the lower limit critical solution temperature is 45 ° C) 0.09 g instead of METOLOSE (registered trademark) 65SH-50 (HPMC (65SH-50)) 0.09g, the mixing temperature when preparing the dispersion medium The composite particles were obtained in the same manner as in Example 3 except that the temperature was changed to 40 ° C at 60 ° C.

The obtained composite particles had a volume average particle diameter of 19.8 μm, a specific surface area of 0.29 m ² /g, and a strong heat residual component of 0.80% by weight. Further, the amount of the cerium oxide particles added was 0.029 g/m ² , and the amount of the cerium oxide particles in the obtained composite particles was 0.028 g/m ² .

[Example 9: Production Example of Composite Particles]

The amount of Snowtex (registered trademark) O-40 (ST-O-40) used as the cerium oxide particles was changed to 2.75 g (SiO ₂ purity was 1.1 g), and METOLOSE (registered trademark) was used as the water-soluble cellulose. In the same manner as in Example 1, except that the amount of use of 65SH-400 (HPMC (65SH-400)) was changed to 022 g, and the number of revolutions of the homomixer was changed from 4,500 rpm to 9000 rpm, composite particles were obtained.

The obtained composite particles had a volume average particle diameter of 7.9 μm, a specific surface area of 0.63 m ² /g, and a strong heat residual component of 1.45 wt%. Further, the amount of the cerium oxide particles added was 0.033 g/m ² , and the amount of the cerium oxide particles in the obtained composite particles was 0.023 g/m ² .

[Example 10: Production Example of Composite Particles]

The amount of Snowtex (registered trademark) O-40 (ST-O-40) used as the cerium oxide particles was changed to 0.55 g (SiO ₂ purity was 0.22 g), and METOLOSE (registered trademark) was used as the water-soluble cellulose. In the same manner as in Example 1, except that the amount of use of 65SH-400 (HPMC (65SH-400)) was changed to 0.04 g, and the number of revolutions of the homomixer was changed from 4,500 rpm to 2,500 rpm, composite particles were obtained.

The obtained composite particles had a volume average particle diameter of 40.9 μm, a specific surface area of 0.13 m ² /g, and a strong heat residual component of 0.29% by weight. Further, the amount of the cerium oxide particles added was 0.033 g/m ² , and the amount of the cerium oxide particles in the obtained composite particles was 0.022 g/m ² .

[Example 11: Production Example of Composite Particles]

The amount of Snowtex (registered trademark) O-40 (ST-O-40) used as the cerium oxide particles was changed to 0.28 g (SiO ₂ purity was 0.11 g), and METOLOSE (registered trademark) was used as the water-soluble cellulose. In the same manner as in Example 1, except that the amount of use of 65SH-400 (HPMC (65SH-400)) was changed to 0.02 g, and the number of revolutions of the homomixer was changed from 4500 rpm to 2500 rpm, composite particles were obtained.

The obtained composite particles had a volume average particle diameter of 80.7 μm, a specific surface area of 0.06 m ² /g, and a strong heat residual component of 0.15% by weight. Further, the amount of the cerium oxide particles added was 0.033 g/m ² , and the amount of the cerium oxide particles in the obtained composite particles was 0.025 g/m ² .

[Example 12: Production Example of Composite Particles]

The amount of water used as the aqueous medium was changed to 200 g, and the amount of Snowtex (registered trademark) O-40 (ST-O-40) used as the cerium oxide particles was changed to 4.0 g (SiO ₂ purity was 1.6 g). The amount of METOLOSE (registered trademark) 65SH-400 (HPMC (65SH-400)) used as a water-soluble cellulose was changed to 0.32 g, and methyl methacrylate (MMA) was used as a polymerizable vinyl monomer. 140g and trimethylolpropane triacrylate (TMPTA) 60g instead of methyl methacrylate (MMA) 50g and ethylene glycol dimethacrylate (EGDMA) 2.5g, as a polymerization initiator, using oxidized laurel (LPO) 1.0 g of the composite particles were obtained in the same manner as in Example 1 except that 0.5 g of 2,2'-azobis(2,4-dimethylvaleronitrile) (ADVN) was used.

The obtained composite particles had a volume average particle diameter of 20.1 μm, a specific surface area of 0.29 m ² /g, and a strong heat residual component of 0.70% by weight. Further, the amount of the cerium oxide particles added was 0.029 g/m ² , and the amount of the cerium oxide particles in the obtained composite particles was 0.024 g/m ² .

[Comparative Example 1: Comparative Production Example of Composite Particles]

A suspension polymerization was carried out in the same manner as in Example 1 except that METOLOSE (registered trademark) 65SH-400 (HPMC (65SH-400)) which is a water-soluble cellulose was used, but the monomer mixture liquid in the dispersion medium was used. The stability of the droplets is low and composite particles cannot be obtained.

[Comparative Example 2: Comparative Production Example of Composite Particles]

A suspension polymerization was carried out in the same manner as in Example 1 except that Snowtex (registered trademark) O-40 (ST-O-40) as the cerium oxide particles was not used, but the monomer mixture droplets in the dispersion medium were The stability is low and composite particles cannot be obtained.

[Comparative Example 3: Comparative Manufacturing Example of Composite Particles]

In the preparation of dispersion media, GOHSENAL GL-05 (referred to as 0.09 g of "GL-05" and polyvinyl alcohol (PVA) manufactured by Nippon Synthetic Chemical Co., Ltd., instead of METOLOSE (registered trademark) 65SH-400 (HPMC (65SH-400)) 0.09 g as a water-soluble cellulose. Otherwise, suspension polymerization was carried out in the same manner as in Example 1, but the stability of the monomer mixture droplets in the dispersion medium was low, and composite particles could not be obtained.

[Comparative Example 4: Comparative Production Example of Composite Particles]

200 g of water as an aqueous medium, and Snowtex (registered trademark) OXS (hereinafter referred to as "ST-OXS", a colloidal cerium oxide manufactured by Nissan Chemical Industries Co., Ltd.) as a cerium oxide particle, in a polymerization vessel having a stirring device, The average primary particle diameter was 7.8 nm, the solid content was 15% by weight, 2.67 g (SiO ₂ purity was 0.40 g), and the polyoxyethylene lauryl ether as a surfactant was 0.02 g, and the mixture was mixed at a temperature of 30 ° C for 1 hour. . Thereby, a dispersion medium containing cerium oxide particles and a surfactant is obtained.

Further, 140 g of methyl methacrylate (MMA), 60 g of trimethylolpropane triacrylate (TMPTA), and 1.0 g of oxidized Laurel (LPO) as a polymerization initiator were uniformly used as the polymerizable vinyl monomer. The mixture was dissolved while being dissolved to prepare a monomer mixture containing a polymerization initiator.

The monomer mixture containing the polymerization initiator is added to the above dispersion medium in the polymerization vessel, and the monomer mixture is finely dispersed in the dispersion medium by stirring at 4,500 rpm for about 3 minutes by a homomixer. Thereafter, 1.0 g of PVA-420 (polyvinyl alcohol (PVA) manufactured by KURARAY Co., Ltd.) was added as a dispersion stabilizer.

Thereafter, stirring was continued at a stirring speed of 100 rpm, and suspension polymerization was carried out for 6 hours after the temperature of the dispersion medium to which the above monomer mixture was added was 55 °C.

Next, the reaction liquid in the polymerization vessel was cooled to room temperature while stirring. Next, the reaction liquid was suction-filtered using qualitative filter paper 101 ("Toyo-Qualified Filter Paper" manufactured by Aimoto Co., Ltd.), washed with ion-exchanged water, followed by deliquoring, and then The composite particles were obtained by drying in a 90 ° C oven for a day and night.

The obtained composite particles had a volume average particle diameter of 20.6 μm, a specific surface area of 0.29 m ² /g, and a strong heat residual component of 0.10% by weight. Further, the amount of the cerium oxide particles added was 0.0069 g/m ² , and the amount of the cerium oxide particles in the obtained composite particles was 0.0034 g/m ² .

[Comparative Example 5: Comparative Production Example of Composite Particles]

As the cerium oxide particles, Snowtex (registered trademark) OL (abbreviated as "ST-OL", colloidal cerium oxide manufactured by Nissan Chemical Industries, Ltd., average primary particle diameter of 70 nm, solid content of 20% by weight) 1.0 is used. g (SiO ₂ purity: 0.20 g) instead of Snowtex (registered trademark) OXS (ST-OXS) 2.67 g (SiO ₂ purity: 0.40 g), and the amount of polyoxyethylene lauryl ether used was changed to 0.03 g, and In Comparative Example 4, the production of the composite particles was carried out in the same manner. The particles obtained in Comparative Example 5 had a volume average particle diameter of 20.4 μm and a specific surface area of 0.29 m ² /g. Further, although the amount of the cerium oxide particles added was 0.0034 g/m ² , the strong heat residual component did not reach the lower limit of the predetermined amount. Since the strong heat residual component did not reach the lower limit of the predetermined amount, it was considered that the particles obtained in Comparative Example 5 were substantially free of cerium oxide particles, and it was considered that it was not a composite particle but a polymer particle.

[Comparative Example 6: Comparative Production Example of Composite Particles]

As the cerium oxide particles, Snowtex (registered trademark) MP-2040 (abbreviated as "ST-OXS", colloidal cerium oxide manufactured by Nissan Chemical Industries, Ltd., average primary particle diameter of 200 nm, and solid content of 40% by weight) is used. In the same manner as in Comparative Example 4, 0.5 g (SiO ₂ purity: 0.20 g) was used instead of Snowtex (registered trademark) OXS (ST-OXS) 2.67 g (SiO ₂ purity: 0.40 g), and the production of composite particles was attempted. . The particles obtained in Comparative Example 6 had a volume average particle diameter of 20.1 μm and a specific surface area of 0.29 m ² /g. Further, the amount of the cerium oxide particles added was 0.0034 g/m ² , and the strong residual component of the heat did not reach the lower limit of the predetermined amount. Since the strong heat residual component did not reach the lower limit of the predetermined amount, it was considered that the particles obtained in Comparative Example 6 were substantially free of cerium oxide particles, and it was considered that it was not a composite particle but a polymer particle.

[Comparative Example 7: Comparative Production Example of Composite Particles]

As the cerium oxide particles, Snowtex (registered trademark) MP-4540M (abbreviated as "ST-MP-4540M", colloidal cerium oxide manufactured by Nissan Chemical Industries Co., Ltd., having an average primary particle diameter of 450 nm and a solid content of 40 is used. 1.5% by weight (SiO ₂ purity: 0.60 g) instead of Snowtex (registered trademark) OXS (ST-OXS) 2.67 g (SiO ₂ purity: 0.40 g), and the amount of polyoxyethylene lauryl ether used was changed to 0.06 g. Otherwise, the production of the composite particles was attempted in the same manner as in Comparative Example 4.

The particles obtained in Comparative Example 7 had a volume average particle diameter of 20.3 μm and a specific surface area of 0.29 m ² /g. Further, although the amount of the cerium oxide particles added was 0.010 g/m ² , the strong heat residual component did not reach the lower limit of the predetermined amount. Since the strong heat residual component did not reach the lower limit of the predetermined amount, it was considered that the particles obtained in Comparative Example 7 were substantially free of cerium oxide particles, and it was considered that it was not a composite particle but a polymer particle.

[Comparative Example 8: Comparative Production Example of Composite Particles]

After putting water, cerium oxide particles, and water-soluble cellulose into a polymerization vessel having a stirring device, it is not mixed at a temperature of 60 ° C for 24 hours (not for adsorbing water-soluble cellulose) In the same manner as in Example 1, except that the dispersion medium containing the water-soluble cellulose and the cerium oxide particles was obtained by the treatment on the cerium oxide particles, the production of the composite particles was attempted, but the particles were bonded to each other during the polymerization. A composite particle is obtained.

[Comparative Example 9: Comparative Production Example of Composite Particles]

The amount of use of Snowtex (registered trademark) OXS (ST-OXS) as cerium oxide particles was changed to 10.6 g (SiO ₂ purity was 1.6 g), and the amount of polyoxyethylene lauryl ether used as a surfactant was changed to In the same manner as in Comparative Example 4, the production of the composite particles was carried out in the same manner as in Comparative Example 4 except that the number of revolutions of the homomixer was changed from 4,500 rpm to 9000 rpm.

The composite particles obtained in Comparative Example 9 had a volume average particle diameter of 4.7 μm, a specific surface area of 1.06 m ² /g, and a strong heat residual component of 0.40% by weight. Further, the amount of the cerium oxide particles added was 0.0075 g/m ² , and the amount of the cerium oxide particles in the obtained composite particles was 0.0038 g/m ² .

[Comparative Example 10: Comparative Production Example of Composite Particles]

The amount of use of Snowtex (registered trademark) OXS (ST-OXS) as cerium oxide particles was changed to 0.67 g (SiO ₂ purity was 0.10 g), and the number of revolutions of the homomixer was changed from 4500 rpm to 1500 rpm. In Comparative Example 4, the production of the composite particles was carried out in the same manner.

The particles obtained in Comparative Example 10 had a volume average particle diameter of 130 μm and a specific surface area of 0.04 m ² /g. Further, although the amount of the cerium oxide particles added was 0.010 g/m ² , the strong heat residual component did not reach the lower limit of the predetermined amount. Since the strong heat residual component did not reach the lower limit of the predetermined amount, it was considered that the particles obtained in Comparative Example 10 were substantially free of cerium oxide particles, and it was considered that it was not a composite particle but a polymer particle.

In the examples 1 to 12 and the comparative examples 1 to 10, the measurement results of the amounts of the various raw materials used in the production and the average primary particle diameter of the ceria particles used in the production were produced. The volume average particle diameter, the specific surface area, and the measurement result of the strong heat residual component of the obtained particles (composite particles), the calculation result of the addition amount of the cerium oxide particles, and the oxidation in the composite particles obtained by the production The calculation results of the adhesion amount of the cerium particles are shown in Tables 1 to 4.

[Table 3] continued

[Table 4] continued

From the results shown in Tables 1 to 4, it is considered that the particles obtained in Examples 1 to 12 are composite particles containing polymer particles and cerium oxide particles adhering to the surface of the polymer particles. Further, in Examples 1 to 12, when the composite particles obtained by the suspension polymerization were washed and degreased, the ceria particles did not substantially fall off, and the results obtained in Examples 1 to 12 were considered to be obtained. The composite particles are those in which the cerium oxide particles are firmly adhered to the surface of the polymer particles, that is, the cerium oxide particles are hard to fall off from the surface of the polymer particles. Further, in Examples 1 to 12 obtained in Example embodiment the composite particles, the amount of silicon dioxide particles adhered to the surface of the polymer particles up to ^{0.010g / m 2 ~ 0.10g / m} 2 ( specifically, 0.011g / m ² to 0.066 g/m ² ), the composite particles of the present invention are considered to be composite particles having a large amount of cerium oxide particles adhered to the surface of the polymer particles.

On the other hand, in Comparative Example 1 to Comparative Example 3 and Comparative Example 8, particles were not obtained. Further, in Comparative Example 5 to Comparative Example 7 and Comparative Example 10 in which the resin particles are produced according to Patent Document 1, although polymer particles are obtained, the amount of addition to the cerium oxide particles is known (Patent Literature In the so-called coating amount in 1, the amount of adhesion of the cerium oxide particles on the surface of the polymer particles is small. Specifically, in Comparative Example 5 to Comparative Example 7 and Comparative Example 10, the amount of the cerium oxide particles added was 0.0034 g/m ² to 0.010 g/m ² , but the strong residual component did not reach the lower limit of the predetermined amount. It was confirmed that the cerium oxide particles adhered to the surface of the obtained polymer particles. Further, in Comparative Example 4 and Comparative Example 9, composite particles including polymer particles and cerium oxide particles adhering to the surface of the polymer particles were obtained, but the composite particles obtained by suspension polymerization were washed and When the liquid was removed, it was confirmed that the cerium oxide particles fell off. That is, it is considered that the composite particles obtained in Comparative Example 4 and Comparative Example 9 are those in which the cerium oxide particles are not firmly adhered to the surface of the polymer particles, that is, the cerium oxide particles are easily detached from the surface of the polymer particles. Further, in Comparative Example 4 and Comparative Example 9, although the amount of the cerium oxide particles added was 0.0069 g/m ² to 0.0075 g/m ² , the adhesion of the cerium oxide particles on the surface of the polymer particles of the obtained composite particles was obtained. The amount is 0.0034 g/m ² to 0.0038 g/m ² , which is smaller than the amount of the above-mentioned cerium oxide particles, and the adhesion to the cerium oxide particles on the surface of the polymer particles of the composite particles of Examples 1 to 12. The amount is also small.

[Example 13: Production Example of Optical Film]

30 g of the particles (composite particles) obtained in Example 8 and an acrylic polyol (trade name: medium VM, manufactured by Dairi Seiki Co., Ltd., resin solid content: 34% by weight, solvent dispersion) 100 g as a binder resin 30 g of an isocyanate (trade name: VM-D, manufactured by Dairi Seiki Co., Ltd.) as a curing agent was mixed to obtain a coating agent. Thereafter, the obtained coating agent was applied onto a polyester film having a thickness of 100 μm as a substrate by an applicator, and then dried by hot air at 70 ° C for 10 minutes to obtain an optical film. The total light transmittance, haze, and gloss of the obtained optical film were measured. The results are shown in Table 5 below.

[Method for measuring total light transmittance and haze]

The haze and total light transmittance of the optical film obtained in Example 13 can be measured using a haze meter "NDH-4000" manufactured by Nippon Denshoku Industries Co., Ltd. The measurement of the total light transmittance was carried out in accordance with JIS K 7361-1, and the measurement of the haze was carried out in accordance with JIS K 7136. Further, the haze and the total light transmittance shown in Table 3 are the average values of the measured values of the two measurement samples (the number of measurement samples is n=2). The higher the diffusibility of light (transmitted light) transmitted through the optical film, the higher the haze value.

[Method for measuring glossiness]

The gloss of the optical film obtained in Example 13 was measured using GLOSS CHECKER "IG-331" manufactured by Horiba, Ltd. Specifically, the gloss of the optical film at 60° was measured by the above-described GLOSS CHECKER (IG-331) based on the method described in JIS Z8741. The higher the diffusibility of the light reflected by the surface of the optical film (specifically, the surface of the coating film formed by applying the coating agent), the lower the value of the glossiness, and the better the matt property.

[Example 14: Production Example of External Agent (Body Emulsion)]

3 parts by weight of the composite particles obtained in Example 8, 50 parts by weight of ethanol, 0.1 parts by weight of glycyrrhizic acid, 0.5 parts by weight of perfume, and 46.4 parts by weight of purified water were thoroughly mixed by a mixer to obtain a body lotion.

The present invention may be embodied in other various forms without departing from the spirit or essential characteristics thereof. Therefore, the above embodiments are merely illustrative in every respect and are not to be construed as limiting. The scope of the present invention is expressed by the scope of the claims, and does not limit the scope of the specification. Further, variations or modifications of the equivalent scope of the claims are intended to be within the scope of the invention.

[Industrial availability]

The composite particles of the present invention can be used, for example, as a coating agent (coating composition) for coating materials, coating agents for paper, coating agents for information recording paper, and coating agents for optical members such as optical films. Additives (matting agent, film softener, design imparting agent, etc.); light diffusion formulated in a light diffusing resin composition for producing a light diffuser (lighting cover, light diffusing plate, light diffusing film, etc.) An anti-caking agent for a film such as a film for food packaging; a raw material for an external preparation such as an additive for external use such as cosmetics (an additive for improving slidability or correcting skin defects such as spots or wrinkles).

Claims (14)

A method for producing composite particles, which is a method for producing composite particles comprising polymer particles and cerium oxide particles adhering to the polymer particles, characterized in that it comprises a polymerization step, and the polymerization step adsorbs water at the surface In the presence of the cellulose-based cerium oxide particles, the polymerizable monomer is subjected to aqueous suspension polymerization to obtain the above composite particles. The method for producing a composite particle according to the above aspect of the invention, wherein the water-soluble cellulose is hydroxypropylcellulose and/or hydroxypropylmethylcellulose. The method for producing composite particles according to claim 1 or 2, wherein before the polymerization step, an adsorption step is included, and the adsorption step is performed on the cerium oxide particles by the water-soluble cellulose. The water-soluble cellulose is adsorbed on the surface of the above-mentioned ceria particles. The method for producing a composite particle according to the third aspect of the invention, wherein, in the adsorption step, at (T-15) ° C (T represents a lower limit critical solution temperature (° C.) of the water-soluble cellulose or The cerium oxide particles and the water-soluble cellulose are coexisted under a temperature condition of a cloud point (°C) or higher, and the water-soluble cellulose is adsorbed on the surface of the cerium oxide particles. The method for producing a composite particle according to the above aspect, wherein the amount of the cerium oxide particles is from 0.022 g/m ² to 0.15 g/m per unit surface area of the composite particles. ² . A composite particle obtained by the method for producing composite particles according to the first or second aspect of the invention, characterized in that at least a part of the surface of the polymer particle is composed of a layer containing cerium oxide particles. Wrapped. A composite particle comprising: polymer particles, cerium oxide particles adhering to the surface of the polymer particles, and water-soluble cellulose. The application of the composite particles range in item 7 patents, wherein the applied amount of the silicon dioxide particles the surface of the polymer particles per unit surface area of the composite particle ^{0.010g / m 2 ~ 0.10g / m} 2. The composite particle according to claim 7 or 8, wherein at least a part of the surface of the polymer particle is coated with a layer of the above-mentioned ceria particle. An external preparation comprising the composite particles according to claim 7 or claim 8. A coating agent comprising the composite particles according to claim 7 or claim 8. An optical film obtained by applying a coating agent according to claim 11 of the invention to a substrate. A resin composition comprising the composite particles according to item 7 or item 8 of the patent application and a base resin. A shaped body characterized by being as described in claim 13 The resin composition is formed.