JP6294204B2 - Composite particle, method for producing composite particle, and use thereof - Google Patents

Description

  The present invention relates to composite particles comprising polymer particles and metal oxide particles containing a metal oxide other than silica attached to the surface of the polymer particles, a method for producing the composite particles, and use thereof (external preparation) , Coating agent, optical film, resin composition, and molded article).

  Polymer particles having an average particle diameter of 0.01 to 100 μm are, for example, fillers for external preparations such as cosmetics (fillers for improving slipperiness), additives for coating agents such as paints (matting agents, etc.) ), Ink additives (matting agents, etc.), adhesive main components or additives, artificial marble additives (low shrinkage agents, etc.), paper treatment agents, column packing materials for chromatography, static It is used in various applications such as toner additives used in charge image development, anti-blocking agents for films, and light diffusing agents for light diffusers (such as light diffusing films).

  In recent years, as one of methods for imparting new characteristics to polymer particles or improving the characteristics of polymer particles, it has been considered that a metal oxide is combined with polymer particles. For example, a technique for enhancing the light scattering effect of a cosmetic composition by attaching titanium oxide to the surface of polymer particles used in the cosmetic composition has been proposed. In Patent Document 1, for the purpose of improving the light scattering effect and the anti-shine effect of the cosmetic composition, flaky titanium oxide or fine particle titanium oxide is added to the spherical resin powder, and then treated with a hammer mill. Thus, a coated spherical powder in which the surface of the spherical resin powder is coated with flaky titanium oxide or fine particle titanium oxide is disclosed (Examples and Comparative Examples).

JP 2004-182666 A

  However, the coated spherical powder obtained by mechanical treatment using a hammer mill or the like as described in Patent Document 1 is a polymer particle surface on the surface of the polymer particles due to the interaction between particles in which flaky titanium oxide or fine particle titanium oxide is weak. It is easily removed by mixing with other substances or impact. Therefore, for example, when the coated spherical powder described in Patent Document 1 is mixed with other substances to produce a product such as an external preparation, a coating agent, or a resin composition, in a stirring process until the product is completed, The flake titanium oxide or fine particle titanium oxide falls off, and the effect of coating with flaky titanium oxide or fine particle titanium oxide (for example, the light scattering effect) decreases.

  In addition, since titanium oxide has a high photocatalytic activity, the coated spherical powder described in Patent Document 1 using titanium oxide is deteriorated (for example, yellowed) by the photocatalytic reaction of titanium oxide and other components by ultraviolet rays. And is inferior in weather resistance.

  The present invention has been made in view of such a situation, and is a composite particle including polymer particles and metal oxide particles containing a metal oxide other than silica attached to the surface of the polymer particles. Thus, it is an object of the present invention to provide composite particles in which metal oxide particles are not easily dropped from polymer particles and have excellent weather resistance, a method for producing the same, and uses of the composite particles.

  The composite particle of the present invention includes polymer particles, metal oxide particles attached to the surface of the polymer particles, and water-soluble celluloses, and the metal oxide particles include silica and a metal oxide other than silica. It is composed of things.

  According to the above configuration, since the metal oxide particles are firmly attached to the surface of the polymer particles due to the inclusion of the water-soluble celluloses, the metal oxide particles are difficult to drop off from the surface of the polymer particles. For this reason, characteristics, such as the ultraviolet shielding property which a metal oxide has, can fully be provided to composite particles.

  Furthermore, according to the said structure, since silica exists in addition to metal oxides other than silica in the said metal oxide particle, especially metal oxides other than a silica have high photocatalytic activity like titanium oxide, zinc oxide, etc. In the case of a metal oxide having silica, silica suppresses the photocatalytic activity of a metal oxide other than silica, so that the metal oxide other than silica and other components deteriorate due to photocatalytic reaction by ultraviolet rays (for example, yellowing). This can be suppressed. As a result, the weather resistance of the composite particles and products using the same can be effectively improved.

  Further, the method for producing composite particles of the present invention includes polymer particles and metal oxide particles attached to the polymer particles, wherein the metal oxide particles are silica particles of metal oxide other than silica. A method for producing composite particles which are silica-coated metal oxide particles coated with water-based suspension polymerization of a polymerizable monomer in the presence of silica-coated metal oxide particles having water-soluble cellulose adsorbed on the surface thereof. And a polymerization step for obtaining composite particles.

  According to the above production method, the water-soluble cellulose is adsorbed on the surface of the silica-coated metal oxide particles because the polymerizable monomer is subjected to aqueous suspension polymerization in the presence of the silica-coated metal oxide particles adsorbed on the surface. Due to the action of water-soluble celluloses, the silica-coated metal oxide particles can be firmly attached to the surface of the polymer particles. For this reason, it is possible to obtain composite particles in which silica-coated metal oxide particles are unlikely to fall off from the surface of the polymer particles, and sufficiently impart properties such as ultraviolet shielding properties possessed by metal oxides other than silica to the composite particles. Can do.

  In addition, since the composite particles obtained by the above production method have metal oxide particles other than silica coated with silica, metal oxides other than silica have high photocatalytic activity such as titanium oxide and zinc oxide. In the case of a metal oxide having silica, the silica inactivates the photocatalytic activity of the metal oxide other than silica, so that the metal oxide other than silica and other components are deteriorated by the photocatalytic reaction by ultraviolet rays (for example, yellowing). Can be suppressed. As a result, the weather resistance of the composite particles and products using the same can be improved.

  Further, the silica-coated metal oxide particles are hydrophilic because silica, which is hydrophilic, is present on the surface thereof, and can be used as a suspension stabilizer (dispersant) when an aqueous suspension polymerization of a polymerizable monomer is performed. Works. Therefore, in the production method, it is not necessary to use a separate suspension stabilizer in order to increase the suspension stability during aqueous suspension polymerization, and the polymerization process can be simplified.

  Moreover, the external preparation of this invention is characterized by including the composite particle of this invention.

  Since the external preparation of the present invention contains the composite particles of the present invention, it has good slip properties and excellent weather resistance, and sufficiently exhibits characteristics such as ultraviolet shielding properties of metal oxides other than silica. be able to. Further, when the external preparation of the present invention contains an aqueous solvent, good dispersibility of the composite particles can be obtained due to the hydrophilicity of the metal oxide particles attached to the surface of the polymer particles.

  The coating agent of the present invention is characterized by containing the composite particles of the present invention.

  Since the coating agent of the present invention contains the composite particles of the present invention, the coating film formed from the coating agent can be imparted with characteristics such as light diffusibility, weather resistance and ultraviolet shielding properties. In the coating agent of the present invention, since the hardness of the composite particles is ensured by the metal oxide particles attached to the surface of the polymer particles, an improvement in scratch resistance of the coating film formed from the coating agent can be expected. . In addition, when the coating agent of the present invention contains an aqueous solvent, good dispersibility of the composite particles can be obtained due to the hydrophilicity of the metal oxide particles attached to the surface of the polymer particles.

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

  Since the optical film of the present invention contains the coating agent of the present invention, it has characteristics such as light diffusibility, weather resistance, and ultraviolet shielding properties.

  The resin composition of the present invention is characterized by including the composite particles of the present invention and a base resin.

  The resin composition of the present invention has characteristics such as light diffusibility, weather resistance, and ultraviolet shielding properties due to the inclusion of the composite particles of the present invention.

  The molded article of the present invention is formed by molding the resin composition of the present invention.

  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 contains light diffusibility, weather resistance, It has characteristics such as ultraviolet shielding properties.

  According to the present invention, composite particles comprising polymer particles and metal oxide particles containing a metal oxide other than silica attached to the surface of the polymer particles, from the polymer particles to the metal oxide particles Can be removed, and composite particles excellent in weather resistance, a production method thereof, and uses of the composite particles can be provided.

2 is a transmission electron microscope (TEM) image showing an enlarged part of a cross section of a composite particle obtained in Example 1. FIG. It is a graph which shows the spectral transmission factor of the optical film obtained in Example 14 and 15. It is a graph which shows the spectral transmittance of the optical film obtained in Example 16 and 17.

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

[Composite particles]
The composite particle of the present invention includes polymer particles, metal oxide particles attached to the surface of the polymer particles, and water-soluble celluloses, and the metal oxide particles include silica and a metal oxide other than silica. It consists of things.

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

In the composite particles of the present invention, the amount of the metal oxide particles attached to the surface of the polymer particles is not particularly limited, but is 0.10 to 1.00 g / m ² per unit surface area of the composite particles. It is preferable to be within the range. When the adhesion amount of the metal oxide particles on the surface of the polymer particles is 0.10 to 1.00 g / m ² per unit surface area of the composite particles, the metal oxide particles adhere to the polymer particles. Thus, the characteristics peculiar to the composite particles can be sufficiently obtained. In the composite particles, the adhesion amount (g / m ² ) of the metal oxide particles on the surface of the polymer particles is, for example, according to the [calculation method of the adhesion amount] described in the section of Examples described later. Can be sought.

(Polymer particles)
The polymer particle is a polymer of a polymerizable monomer. Although it does not specifically limit as said polymerizable monomer, For example, it does not have a phosphate ester bond, but is a compound (henceforth, only a polymerizable vinyl type | system | group) which has a polymerizable carbon-carbon double bond (broadly defined vinyl bond). Monomer) is preferred.

  The polymerizable vinyl monomer is not particularly limited, and includes a monofunctional monomer having one alkenyl group (broadly defined vinyl group), a polyfunctional monomer having two or more alkenyl groups (broadly defined vinyl group), and the like. Can be mentioned.

  Examples of the monofunctional monomer include α-methylene aliphatic monocarboxylic acid ester; styrene; o-methylstyrene, m-methylstyrene, p-methylstyrene, p-ethylstyrene, 2,4-dimethylstyrene, p- n-butyl styrene, p-tert-butyl styrene, pn-hexyl styrene, pn-octyl styrene, pn-nonyl styrene, pn-decyl styrene, pn-dodecyl styrene, p-methoxy Styrene derivatives such as styrene, p-phenylstyrene, p-chlorostyrene, 3,4-dichlorostyrene; vinyl carboxylates such as vinyl acetate, vinyl propionate and vinyl butyrate; other than acrylic esters such as acrylonitrile and acrylamide Acrylic acid derivatives of methacrylonitrile, methacrylamido Methacrylic acid derivatives other than the methacrylic acid esters, such as the like.

  Examples of the α-methylene aliphatic monocarboxylic acid ester include methyl acrylate, ethyl acrylate, propyl acrylate, n-butyl acrylate, isobutyl acrylate, n-octyl acrylate, dodecyl acrylate, and 2-ethylhexyl acrylate. , Stearyl acrylate, lauryl acrylate, 2-chloroethyl acrylate, phenyl acrylate, 2- (dimethylamino) ethyl acrylate, 2- (diethylamino) ethyl acrylate, 2-hydroxyethyl acrylate, 2-hydroxy acrylate Acrylic acid esters such as propyl; methyl methacrylate, ethyl methacrylate, propyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, n-octyl methacrylate, dodecyl methacrylate, 2-ethyl methacrylate Methacrylic acid such as xylyl, stearyl methacrylate, lauryl methacrylate, phenyl methacrylate, 2- (dimethylamino) ethyl methacrylate, 2- (diethylamino) ethyl methacrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate Esters: α-haloacrylate esters such as methyl α-chloroacrylate.

  In some cases, α, β-unsaturated carboxylic acids such as acrylic acid, methacrylic acid, maleic acid, fumaric acid and the like can be used as the monofunctional monomer. Further, two or more of these may be used in combination. In addition, vinyl ethers such as vinyl methyl ether, vinyl ethyl ether, vinyl isobutyl ether; vinyl ketones such as vinyl methyl ketone, vinyl hexyl ketone, methyl isopropenyl ketone; N-vinyl pyrrole, N-vinyl carbazole, N-vinyl indole, N-vinyl compounds such as N-vinylpyrrolidone; vinyl naphthalene salts and the like can be used as a monofunctional monomer in combination of one or two or more in a range not impeding the effects of the present invention.

  In the present invention, the above monofunctional monomers may be used alone or in combination of two or more. Among the monofunctional monomers described above, styrene, methyl methacrylate, and the like are more preferable as the monofunctional monomer used in the present invention because they are inexpensive.

  Examples of the polyfunctional monomer include divinylbenzene; ethylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate (the number of repeating units is 2 to 10), propylene glycol di (meth) acrylate, and polypropylene glycol di (meth) acrylate. (The number of repeating units is 2 to 10), 1,3-butylene glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate, alkoxylated neopentyl glycol di (meth) acrylate, propoxylated neopentyl glycol di (meth) ) Bifunctional alkylene glycol di (meth) acrylates such as acrylate, hydroxypivalate neopentyl glycol di (meth) acrylate, dioxane glycol di (meth) acrylate; Di (meth) acrylate, hexanediol di (meth) acrylate, alkoxylated hexanediol di (meth) acrylate, cyclohexanediol di (meth) acrylate, dodecanediol di (meth) acrylate, tricyclodecanediol di (meth) acrylate, etc. Bifunctional alkylene diol di (meth) acrylate; ethoxylated (2 to 10 repeat units) bisphenol A di (meth) acrylate and other bifunctional ethoxylated bisphenol A di (meth) acrylate; trimethylolpropane tri (meth) Trifunctional trimethylol proppant such as acrylate, ethoxylated trimethylol propane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, triacryloyloxyethyl phosphate Li (meth) acrylates; tetrafunctional tetra (meth) acrylates such as pentaerythritol tetra (meth) acrylate and ditrimethylolpropane tetra (meth) acrylate; hexafunctional dipentaerythritol hexa (such as dipentaerythritol hexa (meth) acrylate) (Meth) acrylates; octafunctional pentaerythritol (meth) acrylates such as poly (pentaerythritol) acrylate; trifunctional nitrogen atom-containing cyclic (meth) acrylates such as ethoxylated isocyanuric acid tri (meth) acrylate It is done. In this application document, “(meth) acrylate” means methacrylate or acrylate.

  When the polymerizable vinyl monomer is used as the polymerizable monomer, the polymerizable vinyl monomer preferably includes both a monofunctional monomer and a polyfunctional monomer. Thereby, a favorable crosslinked structure can be formed in the polymer particles, and good solvent resistance can be imparted to the composite particles. The use amount of the polyfunctional monomer is preferably in the range of 0.5 to 50% by weight, more preferably in the range of 1 to 40% by weight, based on the total use amount of the polymerizable vinyl monomer. preferable. As a result, a better cross-linked structure can be formed in the polymer particles, and further excellent solvent resistance can be imparted to the composite particles.

(Metal oxide particles)
The metal oxide particles are preferably silica-coated metal oxide particles obtained by coating metal oxide particles other than silica with silica. Thereby, especially when the metal oxide other than silica is a metal oxide having high photocatalytic activity such as titanium oxide or zinc oxide, the silica covering the particles of the metal oxide other than silica is a metal other than silica. By inactivating the photocatalytic activity of the oxide, it is possible to effectively suppress the deterioration of the metal oxide other than silica and other components (for example, yellowing) due to the photocatalytic reaction by ultraviolet rays. As a result, the weather resistance of the composite particles and products using the same can be effectively improved.

  The average primary particle diameter of the metal oxide particles is not particularly limited, but is preferably 50 to 200 nm. Metal oxide particles having an average primary particle size of less than 50 nm are difficult to produce, particularly when they are silica-coated metal oxide particles. When the average primary particle diameter of the metal oxide particles is larger than 200 nm, the composite particles are imparted with a desired effect (for example, an ultraviolet shielding effect) with the ratio of the portion covered with the metal oxide particles on the surface of the polymer particles as a desired ratio. In order to do so, a large amount of metal oxide particles are required.

  The content of silica in the metal oxide particles is preferably 10% by weight or more. When the content of silica in the metal oxide particles is less than 10% by weight, the effect of suppressing deterioration (for example, yellowing) due to ultraviolet rays of composite particles of silica or products using the silica is reduced. The silica content in the metal oxide particles is more preferably 10% by weight or more and 50% by weight or less. When the content of silica in the metal oxide particles is more than 50% by weight, imparting of characteristics (for example, ultraviolet shielding characteristics) to the composite particles by metal oxides other than silica is not remarkable.

  Examples of the metal oxide other than silica constituting the metal oxide particles include titanium oxide, zinc oxide, cerium oxide, iron oxide, zirconium oxide, and the like, and at least one of titanium oxide and zinc oxide is preferable. When the metal oxide other than silica is at least one of titanium oxide and zinc oxide, excellent ultraviolet shielding properties can be imparted to the composite particles. In addition, titanium oxide and zinc oxide have high photocatalytic activity. However, in the composite particles of the present invention, titanium oxide, zinc oxide, and other components are contained by inactivating the photocatalytic activity of titanium oxide and zinc oxide. Deterioration (for example, yellowing) due to a photocatalytic reaction by ultraviolet rays can be effectively suppressed. As a result, it is possible to improve the weather resistance of composite particles containing at least one of titanium oxide and zinc oxide as metal oxides other than silica and products using the same.

  The silica-coated metal oxide particles are at least one of silica-coated titanium oxide particles in which titanium oxide particles are coated with silica and silica-coated zinc oxide particles in which zinc oxide particles are coated with silica. preferable. As the silica-coated titanium oxide particles, commercially available products of silica-coated titanium oxide particles or an aqueous dispersion thereof can be used. Examples of commercially available silica-coated titanium oxide particles or aqueous dispersions thereof include “Maxlite (registered trademark) TS-01”, “Maxlite (registered trademark) TS-04”, and “Maxlite (registered trademark)”. “TS-043”, “Maxlite (registered trademark) F-TS20” (manufactured by Showa Denko KK), “MT-100HP”, “MT-100WP”, “MT-500SA”, “WT-PF01” ( (Water dispersion with a solid content of 40% by weight) (above, manufactured by Teika Co., Ltd.), “STR-100A”, “STR-100W”, “GT-10W” (water dispersion with a solid content of 40% by weight) (above, 堺Chemical Industry Co., Ltd.), “ST-455WS” (Titanium Industry Co., Ltd.) and the like.

  As the silica-coated zinc oxide particles, commercially available products of silica-coated zinc oxide particles can be used. Examples of commercially available silica-coated zinc oxide particles include “Maxlite (registered trademark) ZS-032”, “Maxlite (registered trademark) ZS-032-D” (manufactured by Showa Denko KK), “ FINEX (registered trademark) -30W "," FINEX (registered trademark) -50W "(manufactured by Sakai Chemical Industry Co., Ltd.) and the like.

(Water-soluble celluloses)
The water-soluble cellulose is not particularly limited, and examples thereof include alkyl celluloses such as methyl cellulose; hydroxyalkyl celluloses such as hydroxymethyl cellulose, hydroxyethyl cellulose, and hydroxypropyl cellulose; hydroxyalkylalkyl such as hydroxyethyl methyl cellulose and hydroxypropyl methyl cellulose. Compounds such as celluloses are listed. Among these compounds, hydroxyalkylcelluloses and hydroxyalkylalkylcelluloses are preferable, and hydroxypropylcellulose (HPC) and hydroxypropylmethylcellulose (HPMC) are more preferable. These compounds may be used alone or in combination of two or more.

  Hydroxypropyl cellulose (HPC) is generally known to have a lower critical solution temperature (LCST) of 45 ° C., and commercially available products include, for example, NISSO (registered trademark) manufactured by Nippon Soda Co., Ltd. The HPC series (“SSL”, “SL”, “L”, “M”, “H”, etc.) can be mentioned.

  Moreover, as a commercial item of hydroxypropyl methylcellulose (HPMC), Shin-Etsu Chemical Co., Ltd.'s Metroles (registered trademark) series, more specifically, Metrows (registered trademark) 60SH series having a cloud point of 60 ° C. (“ SH60-50 "," 60SH-4000 "," 60SH-10000 "), and Metrows (registered trademark) 65SH series (" 65SH-50 "," 65SH-400 "," 65SH-1500 ") having a cloud point of 65 ° C. , "65SH-4000"), Metroles (registered trademark) 90SH series having a cloud point of 90 ° C ("90SH-100", "90SH-400", "90SH-4000", "90SH-15000"), etc. be able to.

[Production method of composite particles]
The production method of the present invention includes polymer particles and metal oxide particles attached to the polymer particles, wherein the metal oxide particles are silica particles coated with metal oxide particles other than silica. A method for producing composite particles which are coated metal oxide particles, wherein a polymerizable monomer is subjected to aqueous suspension polymerization in the presence of silica-coated metal oxide particles having water-soluble cellulose adsorbed on the surface thereof, and the composite particles A polymerization step is obtained.

  According to the above-described method for producing composite particles, the composite particles of the present invention in which silica-coated metal oxide particles are attached to the surface of polymer particles (polymer of polymerizable monomers), for example, shown in the TEM image of FIG. At least a part of the surface of the polymer particles (the portion below the black spot portion in FIG. 1) is covered with a plurality of the above silica-coated metal oxide particles (black spot portions arranged in an arc shape in FIG. 1). The composite particle formed can be obtained.

(Polymerizable phosphoric acid monomer)
In the production method of the present invention, only the polymerizable vinyl monomer may be used as the polymerizable monomer, but depending on the type of water-soluble cellulose, the polymerizable vinyl monomer and the following formula (1) ) To (5) may be used in combination with the polymerizable phosphoric acid monomer. Depending on the type of water-soluble cellulose, by using the polymerizable vinyl monomer and the polymerizable phosphoric acid monomer in combination, droplets of the polymerizable monomer in an aqueous medium in aqueous suspension polymerization of the polymerizable monomer Stability can be improved. Therefore, in the production method of the present invention, the polymerizable phosphoric acid monomer can be suitably used together with the 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 Formula (3), n is 1-5.)

(In formula (5), n is 1-6.)

  Specific examples of the polymerizable phosphoric acid monomer represented by the above formula (1) include “KAYAMER (registered trademark) PM-21” manufactured by Nippon Kayaku Co., Ltd. (in the above formula (1), n = 1, a = 1 and a mixture in which b = 2 and a compound in which n = 1, a = 2, and b = 1 in the formula (1) in a molar ratio of 1: 1. Specific examples of the polymerizable phosphoric acid monomer represented by the above formula (2) include “KAYAMER (registered trademark) PM-2” manufactured by Nippon Kayaku Co., Ltd., and “Light Ester P” manufactured by Kyoeisha Chemical Co., Ltd. -2M "and the like. Moreover, as a specific example of the polymerizable phosphoric acid monomer represented by the above formula (3), “KAYAMER (registered trademark) PM-1” manufactured by Nippon Kayaku Co., Ltd. (in the above formula (3), n = 1) Compound), “Light Ester P-1M” manufactured by Kyoeisha Chemical Co., Ltd. (a compound in which n = 1 in the above formula (3)), “Phosmer (registered trademark) M” manufactured by Unichemical Co., Ltd. (described above) In the formula (3), a compound in which n = 1, “Phosmer (registered trademark) PE” (a compound in which n = 4 to 5 in the formula (3)) manufactured by Unichemical Co., Ltd., and the like can be given. Specific examples of the polymerizable phosphoric acid monomer represented by the above formula (4) include “Phosmer (registered trademark) CL” manufactured by Unichemical Co., Ltd. Moreover, as a specific example of the polymerizable phosphoric acid monomer represented by the above formula (5), “Phosmer (registered trademark) PP” manufactured by Unichemical Co., Ltd. (in the above formula (5), n = 5-6) A certain compound).

  In the present invention, when the polymerizable phosphoric acid monomer and the polymerizable vinyl monomer are used in combination, the amount of the polymerizable phosphoric acid monomer used is 100 parts by weight of the polymerizable vinyl monomer. It is preferably in the range of 0.01 to 1 part by weight, and more preferably in the range of 0.01 to 0.8 part by weight. When the amount of the polymerizable phosphoric acid monomer used exceeds 1 part by weight with respect to 100 parts by weight of the polymerizable vinyl monomer, the emulsion particles (by-product fine particles by emulsion polymerization) and the like appear during polymerization. In addition, composite particles having a particle size that is too small are likely to be formed, and the coefficient of variation of the particle size of the composite particles may be increased.

(Aqueous medium)
In the polymerization step of the production method of the present invention, the aqueous medium for the aqueous suspension polymerization of the polymerizable monomer is water or a mixture of water and a water-soluble medium (for example, alcohol such as methanol or ethanol). Medium. In order to stabilize the composite particles, the amount of the aqueous medium used is preferably 100 to 1000 parts by weight with respect to 100 parts by weight of the polymerizable monomer.

(Polymerization initiator)
In the polymerization step of the production method of the present invention, the aqueous suspension polymerization of the polymerizable monomer is preferably performed in the presence of a polymerization initiator.

  As the polymerization initiator, oil-soluble peroxide polymerization initiators or azo polymerization initiators that are usually used for aqueous suspension polymerization can be suitably used.

  Examples of the peroxide-based polymerization initiator include benzoyl peroxide, lauroyl peroxide, octanoyl peroxide, orthochlorobenzoyl peroxide, orthomethoxybenzoyl peroxide, methyl ethyl ketone peroxide, diisopropyl peroxydicarbonate, cumene hydroperoxide. , Cyclohexanone peroxide, t-butyl hydroperoxide, diisopropylbenzene hydroperoxide and the like.

  Examples of the azo polymerization initiator include 2,2′-azobisisobutyronitrile, 2,2′-azobis (2,4-dimethylvaleronitrile), 2,2′-azobis (2,3- Dimethylbutyronitrile), 2,2′-azobis (2-methylbutyronitrile), 2,2′-azobis (2,3,3-trimethylbutyronitrile), 2,2′-azobis (2-isopropyl) Butyronitrile), 1,1′-azobis (cyclohexane-1-carbonitrile), 2,2′-azobis (4-methoxy-2,4-dimethylvaleronitrile), (2-carbamoylazo) isobutyronitrile 4,4′-azobis (4-cyanovaleric acid), dimethyl-2,2′-azobisisobutyrate and the like.

  Among the above polymerization initiators, 2,2′-azobisisobutyronitrile, 2,2′-azobis (2,4-dimethylvaleronitrile), benzoyl peroxide, lauroyl peroxide from the viewpoint of decomposition rate and the like. Are preferred as polymerization initiators that can be used in the production method of the present invention.

  The amount of the polymerization initiator used is preferably 0.01 to 10 parts by weight and more preferably 0.1 to 5.0 parts by weight with respect to 100 parts by weight of the polymerizable monomer. preferable. When the amount of the polymerization initiator used is less than 0.01 part by weight relative to 100 parts by weight of the polymerizable monomer, it is difficult to sufficiently perform the polymerization initiation function, and the amount exceeds 10 parts by weight. This is not preferable because an effect commensurate with the amount of use cannot be obtained and the cost is uneconomical.

(Silica-coated metal oxide particles adsorbed with water-soluble celluloses)
In the polymerization step of the production method of the present invention, the aqueous suspension polymerization of the polymerizable monomer is performed in the presence of silica-coated metal oxide particles adsorbed with water-soluble celluloses. In the polymerization step, the silica-coated metal oxide particles adsorbed with the water-soluble celluloses function as a suspension stabilizer.

The amount of the silica-coated metal oxide particles used (hereinafter referred to as addition amount) is preferably 0.10 to 1.50 g / m ² per unit surface area of the composite particles obtained by this production method. When the addition amount of the silica-coated metal oxide particles is less than 0.10 g / m ² , the silica-coated metal oxide particles are not sufficiently adhered to the polymer particle surface in the composite particles. If it exceeds 1.50 g / m ² , an effect commensurate with it may not be obtained, which may be uneconomical.

  The amount of the water-soluble cellulose adsorbed on the silica-coated metal oxide particles can be appropriately set according to the specific surface area of the silica-coated metal oxide particles used in the present invention. It is preferable that it is 0.01g-0.5g per 1g of particle | grains.

  The amount of water-soluble cellulose adsorbed on the silica-coated metal oxide particles can be measured by, for example, Japan Journal of Polymer Science and Technology Vol. 40, No.10, pp. It can be measured using the method described in 697-702 (Oct, 1983). For example, it can be measured by the [Method for measuring the amount of water-soluble cellulose adsorbed on silica-coated metal oxide particles] described in the Examples section described later.

  In the production method of the present invention, before the polymerization step, the silica-coated metal oxide particles are treated with the water-soluble celluloses to adsorb the water-soluble celluloses on the surfaces of the silica-coated metal oxide particles. It is preferable to include an adsorption step.

  The treatment method of the silica-coated metal oxide particles with the water-soluble celluloses for adsorbing the water-soluble celluloses on the surface of the silica-coated metal oxide particles is not particularly limited, for example, in an aqueous medium In which silica particles and water-soluble celluloses are allowed to coexist and water-soluble celluloses are physically adsorbed on the surface of silica particles (for example, Rheological and Interfacial Properties of Silicon Oil Prepared by Polymer Pre-adsorbed on Particles, Colloids Surfaces A: Physicochem. Eng. Aspects, 328, 2008, 114-12. . Method in place of the silica particles in the method) described in the literature using the silica-coated metal oxide particles are preferred. The water-soluble celluloses adsorbed on the silica-coated metal oxide particles by this treatment method are hardly detached from the silica-coated metal oxide particles in the polymerization step and are in a stable state.

  Moreover, more than (T-15) degreeC (T means the lower critical solution temperature (degreeC) or cloud point (degreeC) of the said water-soluble cellulose) more than the said water-soluble cellulose temperature conditions. Preferably, the silica-coated metal is more effectively produced by allowing the silica-coated metal oxide particles and the water-soluble cellulose to coexist under a temperature condition of (T-15) ° C. or higher and (T + 20) ° C. or lower. Water-soluble celluloses can be physically adsorbed on the surface of the oxide particles. In addition, the said water-soluble cellulose has only one of a lower critical solution temperature or a cloud point by the characteristic.

  The water-soluble cellulose that has not been adsorbed to the silica-coated metal oxide particles in the adsorption step may be removed by centrifugation or the like before the polymerization step, or obtained in the polymerization step after the polymerization step. You may remove by washing | cleaning in the refinement | purification process which refine | purifies the obtained composite particle.

  In the production method of the present invention, in the polymerization step, the silica-coated metal oxide is within a range that does not hinder the effect of improving the suspension stability due to the silica-coated metal oxide particles adsorbed by the water-soluble cellulose. Other suspension stabilizers other than particles may also be used.

(Surfactant)
In the polymerization step of the production method of the present invention, the aqueous suspension polymerization of the polymerizable monomer may be performed in the presence of a surfactant in order to further improve the suspension stability. As the 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 soap such as castor oil potash soap; alkyl sulfate ester salt such as sodium lauryl sulfate and ammonium lauryl sulfate; alkylbenzene sulfonate such as sodium dodecylbenzenesulfonate; alkylnaphthalene Examples include sulfonic acid salts; alkane sulfonic acid salts; dialkyl sulfosuccinic acid salts; alkyl phosphoric acid ester salts; naphthalene sulfonic acid formalin condensates; polyoxyethylene alkyl phenyl ether sulfuric acid ester salts;

  Nonionic surfactants include, for example, polyoxyethylene alkyl ether, polyoxyethylene alkyl phenyl ether, polyoxyethylene fatty acid ester, sorbitan fatty acid ester, polyoxyethylene sorbitan fatty acid ester, polyoxyethylene alkylamine, glycerin fatty acid ester, Examples thereof include oxyethylene-oxypropylene block polymers.

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

  Examples of zwitterionic surfactants include lauryl dimethylamine oxide, phosphate ester surfactants, and phosphite ester surfactants.

  The said surfactant may be used independently and may be used in combination of 2 or more type. The surfactant is appropriately selected in consideration of the diameter of the resulting composite particles, the dispersion stability of the polymerizable monomer during aqueous suspension polymerization, and the amount used is appropriately adjusted.

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

  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 polymerization step of the production method of the present invention, the aqueous suspension polymerization of the polymerizable monomer is not limited to the effects of the present invention, and other additives such as pigments, dyes, antioxidants, ultraviolet absorbers. May be performed in the presence of

  Examples of the pigment include inorganic pigments such as lead white, red lead, yellow lead, carbon black, ultramarine, zinc oxide, cobalt oxide, titanium dioxide, iron oxide, titanium yellow, and titanium black; Navels Yellow, Naphthol Yellow S , Yellow pigments such as Hansa Yellow 10G, Benzidine Yellow G, Benzidine Yellow GR, Quinoline Yellow Lake, Permanent Yellow NCG, Tartrazine Lake; Orange Pigments such as Molybdenum Orange, Permanent Orange RK, Benzidine Orange G, Indanthrene Brilliant Orange GK Permanent red 4R, risor red, pyrazolone, red 4R, watching red calcium salt, lake red D, brilliant carmine 6B, eosin lake, rhodamine lake B, alizarin lake, brilia Red pigments such as Tocarmin B; Purple pigments such as Fast Violet B, Methyl Violet Lake, Dioxane Violet; Alkaline Blue Lake, Victoria Blue Lake, Phthalocyanine Blue, Metal-free Phthalocyanine Blue, Phthalocyanine Blue Partial Chloride, Fast Sky Blue, Indance Blue pigments such as Ren Blue BC; Green pigments such as Pigment Green B, Malachite Green Lake, and Fanal Yellow Green G; Isoindolinone pigment, quinacridone pigment, perinone pigment, perylene pigment, insoluble azo pigment, soluble azo pigment, dyeing Mention may be made of organic pigments such as lake pigments.

  Examples of the dye include a nitroso dye, a nitro dye, an azo dye, a stilbene azo dye, a diphenylmethane dye, a triphenylmethane dye, a xanthene dye, an acridine dye, a quinoline dye, a methine dye, a polymethine dye, a thiazole dye, an indamine dye, and an Indian dye. A phenol dye, an azine dye, an oxazine dye, a thiazine dye, a sulfur dye, etc. can be mentioned.

  Examples of the antioxidant include 2,6-di-t-butyl-4-methylphenol (BHT), n-octadecyl-3 ′-(3 ′, 5′-di-t-butyl-4′-hydroxyphenyl). ) Propionate, pentaerythrityl-tetrakis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate], 1,3,5-tris (3,5-di-tert-butyl-4- Hydroxybenzyl) isocyanurate, 1,3,5-trimethyl-2,4,6-tris (3,5-di-tert-butyl-4-hydroxybenzyl) benzene, 3,9-bis [2- {3- Phenolic compounds such as (3-t-butyl-4-hydroxy-5-methylphenyl) propionyloxy} -1,1-dimethylethyl] -2,4,8,10-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′-biphenylenediphosphonite, bis (2-t-butyl-4-methylphenyl) pentaerythritol diphosphite, 2,4,8,10- Phosphorus such as tetra-t-butyl-6- [3- (3-methyl-4-hydroxy-5-t-butylphenyl) propoxy] dibenzo [d, f] [1,3,2] dioxaphosphine System antioxidants; phenyl-1-naphthylamine, octylated diphenylamine, 4,4-bis (α, α-dimethylbenzyl) diphenylamine, Examples thereof include amine antioxidants such as N, N'-di-2-naphthyl-p-phenylenediamine.

  Examples of the ultraviolet absorbers include benzophenone ultraviolet absorbers, benzotriazole ultraviolet absorbers (for example, “ADEKA STAB (registered trademark) LA-31” manufactured by ADEKA Corporation), hydroxyphenyltriazine ultraviolet absorbers, and the like. .

(Suspension polymerization method)
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 silica-coated metal oxide particles having the water-soluble cellulose adsorbed on the surface thereof. For example, in the polymerization step, a monomer mixture is prepared by mixing a polymerizable monomer with a polymerization initiator and / or a polymerization inhibitor and / or other additives as necessary, and the prepared monomer mixture is dissolved in water. Water-based suspension polymerization by dispersing in an aqueous medium containing silica-coated metal oxide particles adsorbed on the surface (optionally further containing a surfactant and / or other suspension stabilizer). I do.

  Examples of the method of dispersing the monomer mixture in the aqueous medium include, for example, a method in which the monomer mixture is directly added to the aqueous medium and dispersed as monomer droplets by stirring force of a propeller blade or the like; the monomer mixture is directly added in the aqueous medium A method of dispersing a monomer mixture in an aqueous medium using a homomixer that is a disperser using a high shear force composed of a rotor and a stator; adding the monomer mixture directly into the aqueous medium; A method of dispersing a monomer mixture in an aqueous medium using a sonic disperser; adding a monomer mixture directly into an aqueous medium, and then using a high-pressure disperser such as a microfluidizer or nanomizer (registered trademark) The monomer mixture is made into an aqueous medium by utilizing collisions between droplets of the monomer mixture and collisions of the monomer mixture droplets with the inner wall of the reaction vessel. The method of dispersing the droplets in a process wherein a monomer mixture through MPG (micro-porous glass) porous membrane is pressed into the aqueous medium and the like. Among these methods, the method using a high-pressure disperser such as the above-mentioned microfluidizer or nanomizer or the method of passing through the above-mentioned MPG (microporous glass) porous film can make the particle diameters more uniform, It can be preferably used as a method of dispersing the mixture in an aqueous medium.

  Subsequently, suspension polymerization is started by heating the aqueous medium (aqueous suspension) in which the monomer mixture is dispersed. It is preferable to stir the aqueous suspension during the polymerization reaction. The stirring may be performed to such an extent that the monomer mixture can be prevented from floating as droplets and the composite particles produced by polymerization can be prevented from settling.

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

  After completion of the polymerization, the obtained composite particles are separated as a hydrous cake by a method such as suction filtration, centrifugal dehydration, centrifugal separation, pressure dehydration, and the obtained hydrous cake is washed with water and dried as necessary. Thus, the desired composite particles can be obtained.

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

  By adjusting the mixing conditions of the monomer mixture and the aqueous medium, the addition amount of other suspension stabilizers and surfactants, the stirring conditions of the above stirrer, the dispersion conditions, etc., the average particle diameter of the obtained composite particles Can be adjusted.

[External preparation]
The composite particles of the present invention are conspicuous for skin defects such as pores, spots and wrinkles due to additives for imparting UV shielding properties, additives for improving the feeling of use such as slipperiness, and light diffusion effects. It can be contained in an external preparation as an additive for eliminating it. The external preparation of the present invention contains 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 according to the type of external preparation, but is preferably in the range of 1 to 80% by weight, and in the range of 3 to 70% by weight. Is more preferable. When the content of the composite particles with respect to the total amount of the external preparation is less than 1% by weight, a clear effect due to the inclusion of the composite particles may not be recognized. On the other hand, if the content of the composite particles exceeds 80% by weight, a remarkable effect commensurate with the increase in content may not be recognized, which is not preferable in terms of production cost.

  The external preparation of the present invention can be used, for example, as an external medicine or cosmetic. The topical medicine is not particularly limited as long as it is applied to the skin, and specific examples include creams, ointments, emulsions and the like. Cosmetics include, for example, soaps, body shampoos, facial cleansing creams, scrub facial cleansers, toothpastes, and other cosmetics; funerals, face powders (loose powders, pressed powders, etc.), foundations (powder foundations, liquid foundations, emulsification types) Foundation), lipstick, lip balm, blusher, eyebrow cosmetics (eye shadow, eyeliner, mascara, etc.), nail polish and other makeup cosmetics; pre-shave lotion, body lotion and other lotions; body powder, baby powder and other bodies External preparations: skin care agents such as lotion, cream, milky lotion (skin lotion), antiperspirants (liquid antiperspirants, solid antiperspirants, cream antiperspirants, etc.), packs, hair washing cosmetics, dyes Hair, hairdressing, aromatic cosmetics, bath preparation, sun Only protection products, suntan products, include the shaving cream and the like.

  The composite particles blended in the external preparation of the present invention may be those treated with a surface treatment agent such as an oil agent, a silicone compound and a fluorine compound, an organic powder, an inorganic powder or the like.

  As the oil agent, any oil agent can be used as long as it is usually used for external preparations. For example, hydrocarbon oils such as liquid paraffin, squalane, petrolatum, paraffin wax; lauric acid, myristic acid, palmitic acid, stearic acid, olein Higher fatty acids such as acid, behenic acid, undecylenic acid, hydroxystearic acid, linoleic acid, lanolin fatty acid, synthetic fatty acid; ester oils such as glyceryl trioctanoate, propylene glycol dicaprate, cetyl 2-ethylhexanoate, isocetyl stearate; beeswax Waxes such as whale wax, lanolin, carnauba wax and candelilla wax; oils and fats such as linseed oil, cottonseed oil, castor oil, egg yolk oil, coconut oil; metal soaps such as zinc stearate and zinc laurate; cetyl alcohol, stearyl Alcohol, olei Higher alcohols such as alcohol and the like. Further, the method of treating the composite particles with the oil agent is not particularly limited. For example, a dry method in which an oil agent is added to the composite particles and the oil agent is coated by stirring with a mixer or the like, and the oil agent is ethanol, propanol, ethyl acetate. A wet method for coating an oil agent can be used by dissolving in a suitable solvent such as hexane by heating, adding composite particles thereto, mixing and stirring, and then removing the solvent under reduced pressure or removing by heating.

  Any silicone compound may be used as long as it is usually used for external preparations. For example, dimethylpolysiloxane, methylhydrogenpolysiloxane, methylphenylpolysiloxane, acrylic-silicone graft polymer, and organic silicone resin partially crosslinked. Type organopolysiloxane polymer. The method for treating the composite particles with the silicone compound is not particularly limited, and for example, the dry method or the wet method described above can be used. In addition, if necessary, a baking treatment may be performed, or in the case of a reactive silicone compound, a reaction catalyst or the like may be added as appropriate.

  The fluorine compound may be any compound as long as it is usually blended with an external preparation. Examples thereof include perfluoroalkyl group-containing esters, perfluoroalkylsilanes, perfluoropolyethers, and polymers having a perfluoro group. A method for treating the composite particles with the fluorine compound is not particularly limited, and for example, the dry method or the wet method described above can be used. In addition, if necessary, a baking treatment may be performed, or in the case of a reactive fluorine compound, a reaction catalyst or the like may be added as appropriate.

  Examples of the organic powder include natural polymer compounds such as gum arabic, tragacanth gum, guar gum, locust bean gum, karaya gum, Irish moss, quince seed, gelatin, shellac, rosin, and casein; sodium carboxymethyl cellulose, hydroxyethyl cellulose, methyl cellulose Semi-synthetic polymer compounds such as ethyl cellulose, sodium alginate, ester gum, nitrocellulose, hydroxypropyl cellulose, crystalline cellulose; polyvinyl alcohol, polyvinyl pyrrolidone, sodium polyacrylate, carboxyvinyl polymer, polyvinyl methyl ether, polyamide resin, silicone oil , Nylon particles, polymethyl methacrylate particles, crosslinked polystyrene particles, silicone particles, urethane particles, Riechiren particles include resin particles such as fluorine resin particles. Examples of the inorganic powder include iron oxide, ultramarine blue, salmon, chromium oxide, chromium hydroxide, carbon black, manganese violet, titanium oxide, zinc oxide, talc, kaolin, mica, calcium carbonate, magnesium carbonate, and silicic acid. Examples thereof include aluminum, barium silicate, calcium silicate, magnesium silicate, silica, zeolite, barium sulfate, calcined calcium sulfate (baked gypsum), calcium phosphate, hydroxyapatite, and ceramic powder. These organic powders and inorganic powders may be subjected to surface treatment in advance. As the surface treatment method, a known surface treatment technique as described above can be used.

  Moreover, the main agent or additive generally used can be mix | blended with the external preparation of this invention according to the objective in the range which does not impair the effect of this invention. Examples of such a main agent or additive include water, lower alcohol (alcohol having 5 or less carbon atoms), fats and oils, hydrocarbons, higher fatty acids, higher alcohols, sterols, fatty acid esters, metal soaps, moisturizers, Surfactant, polymer compound, coloring material raw material, fragrance, clay minerals, antiseptic / bactericidal agent, anti-inflammatory agent, antioxidant, ultraviolet absorber, organic-inorganic composite particle, pH adjuster (triethanolamine, etc.), Special blending additives, active pharmaceutical ingredients, etc. are mentioned.

  Specific examples of the fats and oils include avocado oil, almond oil, olive oil, cacao fat, beef tallow, sesame fat, wheat germ oil, safflower oil, shea butter, turtle oil, straw oil, persic oil, castor oil, grape oil , Macadamia nut oil, mink oil, egg yolk oil, owl, palm oil, rosehip oil, hydrogenated oil, silicone oil, orange luffy oil, carnauba wax, candelilla wax, whale wax, jojoba oil, montan wax, beeswax, lanolin, etc. It is done.

  Specific examples of the hydrocarbon include liquid paraffin, petrolatum, paraffin, ceresin, microcrystalline wax, squalane and the like.

  Specific examples of the higher fatty acid include fatty acids having 11 or more carbon atoms such as 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. Is mentioned.

  Specific examples of the higher alcohol include lauryl alcohol, cetyl alcohol, cetostearyl alcohol, stearyl alcohol, oleyl alcohol, behenyl alcohol, lanolin alcohol, hydrogenated lanolin alcohol, hexyldecanol, octyldecanol, isostearyl alcohol, jojoba alcohol And alcohols having 6 or more carbon atoms such as decyltetradecanol.

  Specific examples of the sterol include cholesterol, dihydrocholesterol, phytocholesterol and the like.

  Specific examples of the fatty acid esters include linoleic acid esters such as ethyl linoleate; lanolin fatty acid esters such as lanolin fatty acid isopropyl; lauric acid esters such as hexyl laurate; isopropyl myristate, myristyl myristate, cetyl myristate, myristic acid Myristate esters such as octyldecyl and octyldodecyl myristate; oleate esters such as decyl oleate and octyldodecyl oleate; dimethyloctanoate such as hexyldecyl dimethyloctanoate; cetyl isooctanoate (cetyl 2-ethylhexanoate) Isooctanoic acid ester such as decyl palmitate; glyceryl trimyristate, tri (caprylic / capric acid) glycerin, propylene dioleate Glycol, triisostearate glycerin, triisooctanoate glycerin, cetyl lactate, myristyl lactate, diisostearyl malate, cholesteryl isostearate, cyclic alcohol fatty acid esters such as 12-hydroxystearic acid cholesteryl, and the like.

  Specific examples of the metal soap include zinc laurate, zinc myristate, magnesium myristate, zinc palmitate, zinc stearate, aluminum stearate, calcium stearate, magnesium stearate, zinc undecylenate and the like.

  Specific examples of the humectant include glycerin, propylene glycol, 1,3-butylene glycol, polyethylene glycol, sodium dl-pyrrolidonecarboxylate, sodium lactate, sorbitol, sodium hyaluronate, polyglycerin, xylit, maltitol and the like. It is done.

  Specific examples of the surfactant include anionic surfactants such as higher fatty acid soaps, higher alcohol sulfates, N-acyl glutamates and phosphates; cationic interfaces such as amine salts and quaternary ammonium salts. Active agents: amphoteric surfactants such as betaine type, amino acid type, imidazoline type, lecithin; fatty acid monoglyceride, polyethylene glycol, propylene glycol fatty acid ester, sorbitan fatty acid ester (for example, sorbitan isostearate), sucrose fatty acid ester, polyglycerin fatty acid Nonionic surfactants such as esters and ethylene oxide condensates are listed.

  Specific examples of the polymer compound include natural polymer compounds such as gum arabic, gum tragacanth, guar gum, locust bean gum, karaya gum, iris moss, quince seed, gelatin, shellac, rosin, and casein; sodium carboxymethyl cellulose, hydroxyethyl cellulose, Semi-synthetic polymer compounds such as methyl cellulose, ethyl cellulose, sodium alginate, ester gum, nitrocellulose, hydroxypropyl cellulose, crystalline cellulose; polyvinyl alcohol, polyvinyl pyrrolidone, sodium polyacrylate, carboxyvinyl polymer, polyvinyl methyl ether, polyamide resin, silicone Oil, nylon particles, poly (meth) acrylate particles (for example, polymethyl methacrylate particles), polyester Styrene particles, silicone particles, urethane particles, synthetic polymer compounds such as resin particles and polyethylene particles. In the present application documents, “(meth) acryl” means methacryl or acryl.

  Specific examples of the color material raw material include iron oxide (red iron oxide, yellow iron oxide, black iron oxide, etc.), ultramarine blue, sweet potato, chromium oxide, chromium hydroxide, carbon black, manganese violet, titanium oxide, zinc oxide, Talc, kaolin, calcium carbonate, magnesium carbonate, mica, aluminum silicate, barium silicate, calcium silicate, magnesium silicate, silica, zeolite, barium sulfate, calcined calcium sulfate (baked gypsum), calcium phosphate, hydroxyapatite, ceramic powder And inorganic pigments such as azo, nitro, nitroso, xanthene, quinoline, anthraquinoline, indigo, triphenylmethane, phthalocyanine, and pyrene.

  In addition, as the powder raw material such as the above-mentioned polymer compound powder raw material and color material raw material, those subjected to surface treatment in advance can be used. As a surface treatment method, known surface treatment techniques can be used, for example, oil treatment with hydrocarbon oil, ester oil, lanolin, etc., silicone treatment with dimethylpolysiloxane, methylhydrogenpolysiloxane, methylphenylpolysiloxane, etc. Fluorine compound treatment with perfluoroalkyl group-containing ester, perfluoroalkylsilane, perfluoropolyether and polymer having perfluoroalkyl group, 3-methacryloxypropyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, etc. Silane coupling agent treatment with isopropyl triisostearoyl titanate, titanium coupling agent treatment with isopropyl tris (dioctylpyrophosphate) titanate, metal soap treatment, acylglutami Amino treatment with acid, lecithin treatment with hydrogenated egg yolk lecithin, collagen treatment, polyethylene process, moisture retention treatment, an inorganic compound treatment, and processing methods such as mechanochemical treatment.

  Specific examples of the clay minerals include components having several functions such as extender pigments and adsorbents, such as talc, mica, sericite, titanium sericite (sericite coated with titanium oxide), and white cloud. Mother, VEEGUM (registered trademark) manufactured by Vanderbilt, and the like.

  Specific examples of the perfume include anisaldehyde, benzyl acetate, geraniol and the like. Specific examples of the antiseptic / bactericidal agent include methyl paraben, ethyl paraben, propyl paraben, benzalkonium, benzethonium and the like. Specific examples of the antioxidant include dibutylhydroxytoluene, butylhydroxyanisole, propyl gallate, tocopherol and the like. Specific examples of the anti-inflammatory agent include ε-aminocaproic acid, glycyrrhizic acid, dipotassium glycyrrhizinate, β-glycyrrhetinic acid, lysozyme chloride, guaiazulene, hydrocortisone and the like. These can be used individually or in mixture of 2 or more types. Specific examples of the ultraviolet absorber include inorganic absorbents such as fine particle titanium oxide, fine particle zinc oxide, fine particle cerium oxide, fine particle iron oxide, fine particle zirconium oxide, benzoic acid-based, paraaminobenzoic acid-based, and anthranilic acid-based. And organic absorbents such as salicylic acid, cinnamic acid, benzophenone, and dibenzoylmethane.

  Specific examples of the special combination additive include hormones such as estradiol, estrone, ethinyl estradiol, cortisone, hydrocortisone, prednisone, vitamins such as vitamin A, vitamin B, vitamin C, vitamin E, citric acid, tartaric acid, lactic acid Skin astringents such as aluminum chloride, aluminum sulfate / potassium sulfate, allantochlorohydroxyalumonium, zinc paraphenol sulfonate, zinc sulfate, cantalis tincture, pepper tincture, ginger tincture, assembly extract, garlic extract, hinokitiol, carpronium chloride , Glycerides of pentadecanoic acid, vitamin E, estrogen, hair growth promoters such as photosensitizers, whitening agents such as phosphoric acid-L-ascorbic acid magnesium and kojic acid.

〔Coating agent〕
The composite particles of the present invention can be contained in a coating agent as an ultraviolet shielding agent, a coating film softening agent, a paint matting agent, a light diffusing agent, and the like. In addition, since metal oxides other than silica, particularly titanium oxide and zinc oxide, have properties such as infrared shielding properties and heat dissipation properties, the composite particles of the present invention are particularly suitable for metal oxides other than silica such as titanium oxide and oxide. In the case of zinc, it is added to the coating agent as a heat shielding agent, a heat insulating agent, a heat radiation agent, etc., and a heat shielding coating agent (thermal insulation paint) mainly used for building materials, and a heat insulating coating agent mainly used for building materials ( Insulating paints), heat radiation coating agents, etc. can also be expected. The coating agent of the present invention contains the composite particles of the present invention.

  The coating agent contains a binder resin as necessary. As the binder resin, an organic solvent or water-soluble resin, or an emulsion-type aqueous resin that can be dispersed in water can be used, and any known binder resin can be used. Examples of the binder resin include trade names “Dianar (registered trademark) LR-102” and “Dianar (registered trademark) BR-106” manufactured by Mitsubishi Rayon Co., Ltd., or products manufactured by Dainichi Seika Kogyo Co., Ltd. Acrylic resins such as “medium VM”; alkyd resins; polyester resins; polyurethane resins; chlorinated polyolefin resins; amorphous polyolefin resins; These binder resins can be appropriately selected depending on the adhesion of the coating agent to the substrate to be coated, the environment in which it is used, and the like.

  The compounding amount of the composite particles is appropriately adjusted depending on the film thickness of the coating film formed by the coating agent containing the binder resin, the average particle diameter of the composite particles, the coating method, the use application, etc., but 100 parts by weight of the binder resin On the other hand, it is preferably in the range of 1 to 300 parts by weight, and more preferably in the range of 5 to 100 parts by weight. When the compounding amount of the composite particles is less than 1 part by weight with respect to 100 parts by weight of the binder resin, the matte effect may not be sufficiently obtained. In addition, when the compounding amount of the composite particles exceeds 300 parts by weight with respect to 100 parts by weight of the binder resin, the dispersion of the composite particles may occur because the viscosity of the coating agent becomes too large. The appearance of the coating film surface may be deteriorated such that microcracks are generated on the surface of the coating film obtained by coating the coating agent or the surface of the coating film obtained is rough.

  The coating agent contains a medium as necessary. As the medium, it is preferable to use a solvent (solvent) capable of dissolving the binder resin or a dispersion medium capable of dispersing the binder resin. As the dispersion medium or solvent, any of an aqueous medium and an oily medium can be used. Oil-based media 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; dioxane, ethylene glycol diethyl ether and ethylene glycol mono And ether solvents such as butyl ether. Examples of the aqueous medium include water and alcohols (for example, isopropanol). These media may use only 1 type and may mix and use 2 or more types. The content of the medium in the coating agent is usually in the range of 20 to 60% by weight with respect to the total amount of the coating agent.

  Furthermore, coating agents include curing agents, colorants (external pigments, color pigments, metal pigments, mica powder pigments, dyes, etc.), antistatic agents, leveling agents, fluidity modifiers, ultraviolet absorbers, light stabilizers, etc. Other additives may be included.

  The substrate to which the coating agent is applied is not particularly limited, and a substrate according to the application can be used.

  For example, in an optical application, a glass substrate, a transparent substrate made of a transparent substrate resin, or the like is used as a substrate to be coated. By using a transparent substrate as the substrate to be coated and coating the transparent substrate with a coating agent that does not contain a colorant to form a transparent coating film, a light diffusion film, an antiglare film, and an ultraviolet shielding film An optical film such as a heat shielding film, a heat insulating film, a heat radiating film, or a heat shielding window glass can be produced. In this case, the composite particles function as a light diffusing agent, an ultraviolet shielding agent, a heat shielding agent, a heat insulating agent, a heat radiation agent, or the like.

  Also, matte paper is manufactured by using paper as the substrate to be coated and coating the transparent substrate with a coating agent (paper coating agent) that does not contain a colorant to form a transparent coating film. can do.

  Moreover, a heat insulating building material can be manufactured by using a building material as a base material to be coated and applying a coating agent on the building material to form a coating film.

  The coating method of the coating agent is not particularly limited, and any known method can be used. Examples of the coating method include a comma direct method, a spin coating method, a spray coating method, a roll coating method, a dipping method, a knife coating method, a curtain flow method, and a laminating method. The coating agent may be diluted by adding a diluent in order to adjust the viscosity as necessary. Diluents 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; ether solvents such as dioxane and ethylene glycol diethyl ether; water An alcohol solvent or the like. These diluents may be used alone or in combination of two or more. When manufacturing an optical film, it is preferable to use a method in which irregularities derived from composite particles are formed on the surface of the coating film as a coating method.

[Optical film]
The optical film of the present invention is obtained by applying the coating agent of the present invention to a film-like substrate. Specific examples of the optical film include a light diffusion film, an antiglare film, an ultraviolet shielding film, a heat shielding film, a heat insulating film, and a heat radiating film.

  Specific examples of the substrate of the optical film include a glass substrate and a transparent substrate made of a transparent substrate resin.

  Examples of the transparent base resin include acrylic resins such as polymethyl methacrylate, polyesters such as alkyl (meth) acrylate-styrene copolymers, polycarbonate, polyethylene terephthalate (hereinafter abbreviated as “PET”), polyethylene, and polypropylene. , Polystyrene and the like. Among these transparent base resins, acrylic resins, alkyl (meth) acrylate-styrene copolymers, polycarbonates, polyesters, and polystyrenes are preferred when excellent transparency is required for the transparent base resins. These transparent base resins can be used alone or in combination of two or more.

  Moreover, it is preferable that the thickness of the coating film obtained by coating a coating agent in an optical film is the range of 5-100 micrometers.

(Resin composition)
The resin composition of the present invention contains the composite particles of the present invention and a base resin. Since the resin composition of the present invention includes the composite particles of the present invention and has light diffusibility, a lighting cover (light emitting diode (LED) lighting lighting cover, fluorescent lamp lighting lighting cover, etc.), light diffusion sheet It can be used as a raw material for a light diffuser such as a light diffusion plate. Furthermore, the resin composition of the present invention can be expected to be used as an ultraviolet shielding material, a heat shielding material, a heat insulating material, a heat radiation material, or the like.

  As the base resin, a thermoplastic resin different from the polymer component constituting the composite particles is usually used. Examples of the thermoplastic resin used as the base resin include acrylic resin, alkyl (meth) acrylate-styrene copolymer, polycarbonate, polyester, polyethylene, polypropylene, and polystyrene. Among these thermoplastic resins, when excellent transparency is required for the base resin, acrylic resin, alkyl (meth) acrylate-styrene copolymer, polycarbonate, polyester, and polystyrene are preferable. These thermoplastic resins can 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 to 70 parts by weight, and in the range of 1 to 50 parts by weight with respect to 100 parts by weight of the base resin. Is more preferable. When the addition ratio of the composite particles to the base resin is less than 0.1 parts by weight with respect to 100 parts by weight of the base resin, it may be difficult to give the resin composition light diffusibility, ultraviolet shielding, or the like. is there. When the addition ratio of the composite particles to the base resin is more than 70 parts by weight with respect to 100 parts by weight of the base resin, the resin composition can be given light diffusibility, but the light diffusibility of the light diffuser May be lower. Although the resin composition can be given light diffusibility, ultraviolet shielding, etc., the light transmittance of the resin composition may be lowered.

  The method for producing the resin composition is not particularly limited, and 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 and mixing method, for example, the resin composition is obtained by mixing and stirring the composite particles and the base resin using an apparatus such as a Henschel mixer, a V-type mixer, a turbula mixer, a hybridizer, and a rocking mixer. Can be manufactured.

[Molded body]
The molded article of the present invention is formed by molding the resin composition of the present invention. Specific examples of the molded article of the present invention include light covers such as lighting covers (light emitting diode (LED) lighting lighting covers, fluorescent lamp lighting lighting covers, etc.), light diffusion sheets, light diffusion plates, etc .; UV shielding materials; Expected to be used as heat shielding material; heat insulating material;

  For example, the composite particles and the base resin are mixed with a mixer and kneaded with a melt kneader such as an extruder to obtain a pellet made of the resin composition, and then the pellet is extruded or the pellet A molded body having an arbitrary shape can be obtained by injection molding after melting.

[Other uses]
Since metal oxides other than silica, particularly titanium oxide and zinc oxide, have a relatively high refractive index, the composite particles of the present invention are particularly effective when the metal oxide other than silica is titanium oxide or zinc oxide. It can be expected to be used as a refractive index adjusting agent added to the optical material in order to adjust the refractive index of the material of the confinement layer, the material of the light extraction layer, and the optical material (for example, optical film). Further, the composite particles of the present invention can be expected to be used as an abrasive because the hardness of the composite particles is ensured by the metal oxide particles attached to the surface of the polymer particles. In addition, since metal oxides other than silica, particularly titanium oxide and zinc oxide, have heat dissipation properties, the composite particles of the present invention can be expected to be used as heat dissipation materials.

  EXAMPLES Hereinafter, although an Example and a comparative example demonstrate this invention concretely, this invention is not limited by these Examples. First, each measuring method in an Example and a comparative example is demonstrated.

[Method for measuring average primary particle diameter of metal oxide particles]
The average primary particle diameter (specifically, the Z average particle diameter calculated by the cumulant analysis method) of the metal oxide particles (silica-coated metal oxide particles or metal oxide particles not coated with silica) is, for example, dynamic The particle size is measured by a particle size measurement apparatus (“Zetasizer Nano ZS” manufactured by Malvern) using a dynamic light scattering method.

  As a measurement sample, a dispersion obtained by dispersing metal oxide particles to be measured in ion-exchanged water is used. When the assumed average primary particle diameter of the metal oxide particles is less than 100 nm, the dispersion is prepared so that the concentration of the metal oxide particles is 1% by weight, and the assumed average primary of the metal oxide particles is When the particle diameter is 100 nm or more, the dispersion is prepared so that the concentration of the metal oxide particles is 0.1% by weight. A polyethylene cell is set in the measurement part of the particle size measuring apparatus by the dynamic light scattering method (“Zetasizer Nano ZS” manufactured by Malvern), and the dispersion is dispensed into the polyethylene cell to obtain a metal oxide. The Z average particle size of the product particles is measured.

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

  In the cumulant analysis method, an average value of the particle diameter and a polydispersity index (PDI) are obtained, and the average value of the particle diameter is defined as the Z average particle diameter. Strictly speaking, the work of fitting a polynomial to the logarithm of the G1 correlation function obtained by measurement is called cumulant analysis, and the constant b in the following equation is called a second-order cumulant or Z-average diffusion coefficient.

LN (G1) = A + bt + ct ² + dt ³ + et ⁴ +...
A value obtained by converting the constant b into a particle diameter using the viscosity of the dispersion and several apparatus constants is the Z average particle diameter.

[Method of measuring the amount of water-soluble cellulose adsorbed on silica-coated metal oxide particles]
For Example 1 described below, a dispersion medium containing silica-coated metal oxide particles adsorbed with water-soluble cellulose obtained in the composite particle production process was used, and water-soluble celluloses per gram of silica-coated metal oxide particles. The amount of adsorption (g) was measured by the following method.

  After 0.25 g of a dispersion medium containing silica-coated metal oxide particles adsorbed with water-soluble celluloses is diluted by adding 1 g of ion-exchanged water, a centrifuge (“Hitachi High-Speed Cooling Centrifuge manufactured by Hitachi High-Technologies Corporation) is used. HIMAC CR22GII ") and centrifuged at 25000 G for 30 minutes. Add 1 ml of a 5 wt% phenol aqueous solution to 1 ml of the obtained supernatant, add 5 ml of concentrated sulfuric acid, leave it for 10 minutes, and then leave it in an aqueous solution at 25 ° C. for 10 minutes to prepare a measurement sample. obtain. About the said measurement sample, the light absorbency in 485 nm is measured with the ultraviolet visible spectrophotometer (Shimadzu Corporation "UV-visible spectrophotometer UV-2450"), and a calibration curve (The relationship between the light absorbency and the density | concentration of water-soluble celluloses) Is used to determine the concentration (g / l) of water-soluble celluloses in the supernatant.

  The calibration curve is created by the following method. That is, three types of aqueous solutions with different concentrations are prepared by adding 0.01 g, 0.05 g, and 0.1 g of water-soluble cellulose used in preparing the dispersion medium to 100 g of ion-exchanged water. 0.25 g of each prepared aqueous solution is diluted with 0.75 g of ion-exchanged water, and the absorbance of each diluted aqueous solution is measured. Then, a calibration curve of a linear curve is created by plotting the weight and absorbance of water-soluble celluloses in the aqueous solution.

  And the adsorption amount (g) of water-soluble cellulose per 1g of silica coating metal oxide particles is calculated | required with the following formula | equation.

D = (W _H −C × V) ÷ Ws
D: Adsorption amount of water-soluble celluloses per gram of silica-coated metal oxide particles (g)
C: Concentration (g / l) of water-soluble celluloses in the supernatant
W _H : Weight of water-soluble cellulose used for production of composite particles (g)
Ws: weight of the silica-coated metal oxide particles used in the production of the composite particles (g)
V: Volume (l) of aqueous medium used for the preparation of the dispersion medium in the production of composite particles
[Measurement method of volume average particle diameter]
The volume average particle diameter of the composite particles obtained in Examples and Comparative Examples described later and the polymer particles used in the Comparative Examples is measured by Coulter Multisizer III (Beckman Coulter, Inc. measuring device). Measurement shall be performed using an aperture calibrated according to the Multisizer ^™ 3 User's Manual issued by Beckman Coulter, Inc.

  The aperture used for the measurement is selected by selecting an aperture having a size of 50 μm when the assumed volume average particle diameter of the particle to be measured (composite particle or polymer particle) is 1 μm or more and 10 μm or less (particles to be measured ( When the assumed volume average particle diameter of the composite particle or polymer particle) is larger than 10 μm and 30 μm or less, an aperture having a size of 100 μm is selected, and the assumed volume average particle diameter of the particle (composite particle or polymer particle) is An aperture having a size of 280 μm is selected when it is greater than 30 μm and 90 μm or less, and an aperture having a size of 400 μm is selected when the assumed volume average particle size of the particles (composite particles or polymer particles) is greater than 90 μm and 150 μm or less. Select as appropriate. When the volume average particle diameter after measurement is different from the assumed volume average particle diameter, the aperture is changed to an aperture having an appropriate size, and measurement is performed again.

  When an aperture having a size of 50 μm is selected, Current (aperture current) is set to −800, Gain (gain) is set to 4, and when an aperture having a size of 100 μm is selected, Current (aperture current) is − 1600, Gain (gain) is set to 2, and when an aperture having a size of 280 μm and 400 μm is selected, Current (aperture current) is set to −3200 and Gain (gain) is set to 1.

  As a sample for measurement, 0.1 g of particles to be measured (composite particles or polymer particles) in 10 ml of 0.1% by weight nonionic surfactant aqueous solution was touch mixer (manufactured by Yamato Scientific Co., Ltd., “TOUCMIXER MT-31”). ) And an ultrasonic cleaner ("ULTRASONIC CLEANER VS-150" manufactured by Velvo Crea Co., Ltd.) and used as a dispersion. Set a beaker filled with ISOTON (registered trademark) II (manufactured by Beckman Coulter Co., Ltd .: electrolyte for measurement) in the measuring section of Coulter Multisizer III, and drop the dispersion while gently stirring the inside of the beaker. Then, after the concentration meter reading on the Coulter Multisizer III main body screen is adjusted to 5 to 10%, the measurement is started. During the measurement, the beaker is gently stirred to such an extent that bubbles do not enter, and the measurement is terminated when 100,000 particles (composite particles or polymer particles) are measured. The volume average particle diameter of the particles (composite particles or polymer particles) is an arithmetic average in the volume-based particle size distribution of 100,000 particles (composite particles or polymer particles).

[Method for measuring ignition residue]
After weighing 1.0 g of the composite particles to be measured, the weighed composite particles are burned off in an electric furnace at 550 ° C. for 30 minutes, and the weight (g) of the remaining residue is measured. Then, the weight (g) of the measured residue is divided by the weight (1.0 g) of the composite particles before the measurement, and converted to a percentage to obtain an ignition residue (% by weight) of the composite particles.

[Method for measuring specific surface area]
0.25 g of the composite particles to be measured was weighed. The weighed composite particles were mixed with 0.025 g of sodium dodecylbenzenesulfonate and 50 g of pure water, and this mixture was stirred with an ultrasonic wave for 10 minutes to disperse the composite particles to obtain a measurement sample. And the specific surface area of the particle | grains in this measurement sample was measured on the following measurement conditions using the laser diffraction type particle size distribution measuring apparatus (The product made from Malvern Instruments Ltd., "Mastersizer 2000").

<Measurement conditions>
Dispersion medium; Water Analytical model; General-purpose particle refractive index; 1.50
Dispersion medium refractive index: 1.33
[Calculation method of addition amount of silica-coated metal oxide particles]
The weight of metal oxide particles (silica-coated metal oxide particles or metal oxide particles not coated with silica) used in the production of composite particles, the weight of polymerizable vinyl monomers used, and the method for measuring the specific surface area Using the specific surface area of the composite particles measured by the above, the addition amount (g / m ² ) of metal oxide particles per unit surface area of the composite particles obtained by the above production is obtained by the following calculation formula.

Addition amount = (W _S ÷ W _m ) ÷ X
W _S : Weight of metal oxide particles used in the production of composite particles (g)
W _m : Weight of polymerizable vinyl monomer used in the production of composite particles (g)
X: Specific surface area (m ² / g) of composite particles measured by the above specific surface area measurement method
[Calculation method of adhesion amount of silica-coated metal oxide particles]
For the composite particles obtained in Examples and Comparative Examples described later, the above ignition residue is the metal oxide particles in the composite particles (silica-coated metal oxide particles or metal oxide particles not coated with silica). ), The following equation is obtained by using the ignition residue measured by the ignition residue measuring method and the specific surface area of the composite particles measured by the specific surface area measuring method. Thus, the adhesion amount (g / m ² ) of the metal oxide particles per unit surface area of the composite particles obtained by the above production is obtained.

Adhering amount = (A ÷ 100) ÷ X
A: ignition residue (% by weight) measured by the method for measuring ignition residue
X: Specific surface area (m ² / g) of composite particles measured by the above specific surface area measurement method
In addition, in the measurement method of the ignition residue, the residue remaining after burning the composite particles in an electric furnace at 550 ° C. for 30 minutes contains components other than the metal oxide particles, and the ignition residue is measured. When the ignition residue measured by the method is different from the amount of the metal oxide particles in the composite particles, the following formula gives the metal oxide particles per unit surface area of the composite particles obtained in the above production. The amount of adhesion (g / m ² ) can be determined. Whether or not the residue contains metal oxide particles and the amount of metal oxide particles contained in the residue can be determined using a known method such as elemental analysis.

Adhesion amount = {(A ÷ 100) × (B ÷ 100)} ÷ X
A: ignition residue (% by weight) measured by the method for measuring ignition residue
B: Content (% by weight) of metal oxide particles in the residue
X: Specific surface area (m ² / g) of composite particles measured by the above specific surface area measurement method
[Measurement method of spectral transmittance of optical film]
Optical film cut into a plane size of 4 cm × 4 cm is sandwiched between cells, and an ultraviolet-visible spectrophotometer equipped with an integrating sphere (manufactured by Shimadzu Corporation, trade name “UV-2450”) has a wavelength of 300 to 800 nm. The transmittance was measured.
[Example 1]
In a container, 150 g of water as an aqueous medium and an ultrafine silica-coated titanium oxide aqueous dispersion “GT-10W” (manufactured by Sakai Chemical Industry Co., Ltd., average primary particle size: 115 nm, solid content as silica-coated metal oxide particles) 40% by weight, silica coating amount (silica-coated metal oxide particle content 20% by weight) 10.58 g (pure amount of silica-coated titanium oxide particles 4.23 g) and “Metroze as water-soluble celluloses” (Registered trademark) 65SH-400 "(abbreviation" HPMC (65SH-400) ", Shin-Etsu Chemical Co., Ltd. hydroxypropylmethylcellulose, cloud point 65 ° C) 0.14 g was added and mixed at a temperature of 60 ° C for 24 hours. did. As a result, a dispersion medium containing silica-coated titanium oxide particles adsorbed with water-soluble celluloses was obtained. When the amount of water-soluble cellulose adsorbed on silica-coated titanium oxide particles was measured using this dispersion medium, 0.023 g of water-soluble cellulose per 1 g of silica-coated titanium oxide particles was adsorbed on silica-coated titanium oxide particles. .

  Separately, 50 g of methyl methacrylate (MMA) as a polymerizable vinyl monomer and 2.5 g of ethylene glycol dimethacrylate (EGDMA) and 2,2′-azobis (2,4-dimethylvaleronitrile) as a polymerization initiator ( ADVN) 0.5 g and 0.2 g of “KAYAMER (registered trademark) PM-21” (abbreviation “PM-21”, manufactured by Nippon Kayaku Co., Ltd.) as a polymerizable phosphoric acid monomer, A monomer mixture containing a polymerization initiator was prepared by dissolution.

  The monomer mixture containing the polymerization initiator is added to the dispersion medium in the container, and the mixture is stirred for about 3 minutes at a rotational speed (stirring speed) of 4000 rpm with a high flex disperser HG92 (manufactured by SMT Co., Ltd.). The monomer mixture was finely dispersed therein.

  To the polymerization vessel having a stirrer, add the finely dispersed monomer mixture in the dispersion medium, and continue stirring at a rotation speed of 100 rpm. The temperature of the dispersion medium to which the monomer mixture is added becomes 50 ° C. Then, suspension polymerization was performed for 6 hours.

  Next, the reaction solution in the polymerization vessel was cooled to room temperature while stirring. Next, the reaction solution was mixed with qualitative filter paper No. 101 (advancetech Toyo Co., Ltd. “Toyo Qualitative Filter Paper”) was suction filtered, washed with ion-exchanged water, subsequently drained, and then dried in an oven at 80 ° C. overnight to obtain composite particles. .

  When the cross section of the obtained composite particle was confirmed by TEM, as shown in FIG. 1, the composite particle was found on the surface of the polymer particle (the part below the black spot in FIG. 1) and the surface of the polymer particle. It was observed that the particles contained silica-coated titanium oxide particles (black dot portions arranged in an arc shape in FIG. 1).

The obtained composite particles have a volume average particle diameter of 17.5 μm, a specific surface area of 0.34 m ² / g, an ignition residue of 7.30% by weight, and silica-coated metal oxidation per unit surface area of the composite particles. the addition amount of the object particles in the 0.23 g / m ^2, the adhesion amount of the silica-coated metal oxide particles per unit surface area of the composite particles was 0.21 g / m ^2.

[Example 2]
The amount of ultrafine silica-coated titanium oxide aqueous dispersion “GT-10W” used as silica-coated metal oxide particles was changed to 22.45 g (pure amount of silica-coated titanium oxide particles 8.98 g), and water-soluble celluloses The amount used of “Metros (registered trademark) 65SH-400” (HPMC (65SH-400)) was changed to 0.30 g, and the rotation speed of the homomixer when finely dispersing was changed from 4000 rpm to 6000 rpm. Except for this, composite particles were obtained in the same manner as in Example 1.

The obtained composite particles have a volume average particle diameter of 7.8 μm, a specific surface area of 0.77 m ² / g, an ignition residue of 12.60% by weight, and silica-coated metal oxide particles per unit surface area of the composite particles. Was 0.22 g / m ² , and the amount of silica-coated metal oxide particles deposited per unit surface area of the composite particles was 0.16 g / m ² .

Example 3
The amount of ultrafine silica-coated titanium oxide aqueous dispersion “GT-10W” used as silica-coated metal oxide particles was changed to 4.50 g (pure amount of silica-coated titanium oxide particles 1.80 g), and water-soluble celluloses The amount of “Metroze (registered trademark) 65SH-400” (HPMC (65SH-400)) was changed to 0.06 g, and the rotation speed of the homomixer when finely dispersing was changed from 4000 rpm to 2000 rpm. Except for this, composite particles were obtained in the same manner as in Example 1.

The obtained composite particles have a volume average particle diameter of 40.2 μm, a specific surface area of 0.15 m ² / g, an ignition residue of 2.88% by weight, and silica-coated metal oxide particles per unit surface area of the composite particles. the amount of addition is 0.23 g / m ^2, the adhesion amount of the silica-coated metal oxide particles per unit surface area of the composite particles was 0.19 g / m ^2.

Example 4
The amount of ultra-fine silica-coated titanium oxide aqueous dispersion “GT-10W” used as silica-coated metal oxide particles was changed to 2.25 g (pure amount of silica-coated titanium oxide particles 0.90 g), and water-soluble celluloses The amount of “Metroze (registered trademark) 65SH-400” (HPMC (65SH-400)) was changed to 0.03 g, and the rotation speed of the homomixer when finely dispersing was changed from 4000 rpm to 1000 rpm. Except for this, composite particles were obtained in the same manner as in Example 1.

The obtained composite particles have a volume average particle diameter of 80.8 μm, a specific surface area of 0.075 m ² / g, an ignition residue of 1.53% by weight, and silica-coated metal oxide particles per unit surface area of the composite particles. the amount of addition is 0.23 g / m ^2, the adhesion amount of the silica-coated metal oxide particles per unit surface area of the composite particles was 0.20 g / m ^2.

Example 5
As silica-coated titanium oxide particles, instead of ultrafine particle silica-coated titanium oxide aqueous dispersion “GT-10W” 10.58 g, ultrafine particle silica-coated titanium oxide “STR-100W” (manufactured by Sakai Chemical Industry Co., Ltd., average primary particle size) : 115 nm, silica coating amount 20% by weight) Except that 4.23 g was used, composite particles were obtained in the same manner as in Example 1.

The obtained composite particles have a volume average particle diameter of 17.2 μm, a specific surface area of 0.35 m ² / g, an ignition residue of 7.62% by weight, and silica-coated metal oxide particles per unit surface area of the composite particles. the amount of addition is 0.23 g / m ^2, the adhesion amount of the silica-coated metal oxide particles per unit surface area of the composite particles was 0.22 g / m ^2.

Example 6
As silica-coated titanium oxide particles, instead of ultrafine silica-coated titanium oxide aqueous dispersion “GT-10W” 10.58 g, ultrafine silica-coated titanium oxide aqueous dispersion “WT-PF01” (manufactured by Teika Co., Ltd., average primary particles) The composite particles were prepared in the same manner as in Example 1 except that 7.90 g (diameter: 86 nm, solid content: 40 wt%, silica coating amount: 20 wt%) (pure amount of silica-coated titanium oxide particles: 3.16 g) was used. Obtained.

The obtained composite particles have a volume average particle diameter of 17.5 μm, a specific surface area of 0.34 m ² / g, an ignition residue of 5.27% by weight, and silica-coated metal oxide particles per unit surface area of the composite particles. Was 0.18 g / m ² , and the amount of silica-coated metal oxide particles deposited per unit surface area of the composite particles was 0.16 g / m ² .

Example 7
As silica-coated titanium oxide particles, instead of 10.58 g of the ultrafine silica-coated titanium oxide aqueous dispersion “GT-10W”, ultrafine silica-coated titanium oxide “MT-100WP” (manufactured by Teika Co., Ltd., average primary particle size: 86 nm) In addition, composite particles were obtained in the same manner as in Example 1 except that 3.16 g of silica covering amount 35 wt% was used.

The obtained composite particles have a volume average particle diameter of 17.6 μm, a specific surface area of 0.34 m ² / g, an ignition residue of 5.59% by weight, and silica-coated metal oxide particles per unit surface area of the composite particles. Was 0.18 g / m ² , and the amount of silica-coated metal oxide particles deposited per unit surface area of the composite particles was 0.16 g / m ² .

Example 8
As water-soluble celluloses, instead of 0.14 g of “Metroze (registered trademark) 65SH-400” (HPMC (65SH-400)), “Metroze (registered trademark) 65SH-4000” (abbreviated as “HPMC (65SH-4000)”) “Shin-Etsu Chemical Co., Ltd. hydroxypropylmethylcellulose, cloud point 65 ° C.) 0.14 g) was used in the same manner as in Example 1 to obtain composite particles.

The obtained composite particles have a volume average particle diameter of 17.1 μm, a specific surface area of 0.35 m ² / g, an ignition residue of 7.85% by weight, and silica-coated metal oxide particles per unit surface area of the composite particles. the amount of addition is 0.23 g / m ^2, the adhesion amount of the silica-coated metal oxide particles per unit surface area of the composite particles was 0.22 g / m ^2.

Example 9
As water-soluble celluloses, instead of 0.14 g of “Metroze (registered trademark) 65SH-400” (HPMC (65SH-400)), “Metroze (registered trademark) 65SH-50” (abbreviation “HPMC (65SH-50)) “Shin-Etsu Chemical Co., Ltd. hydroxypropylmethylcellulose, cloud point 65 ° C.) 0.14 g) was used in the same manner as in Example 1 to obtain composite particles.

The obtained composite particles have a volume average particle diameter of 17.4 μm, a specific surface area of 0.34 m ² / g, an ignition residue of 5.23 wt%, and silica-coated metal oxide particles per unit surface area of the composite particles. the amount of addition is 0.23 g / m ^2, the adhesion amount of the silica-coated metal oxide particles per unit surface area of the composite particles was 0.15 g / m ^2.

Example 10
As water-soluble celluloses, instead of 0.14 g of “Metros (registered trademark) 65SH-400” (HPMC (65SH-400)), “NISSO HPCH” (hydroxypropylcellulose manufactured by Nippon Soda Co., Ltd., lower critical solution) Composite particles were obtained in the same manner as in Example 1 except that 0.14 g (temperature 45 ° C.) was used and the mixing temperature 60 ° C. in preparing the dispersion medium was changed to 40 ° C.

The obtained composite particles have a volume average particle diameter of 17.6 μm, a specific surface area of 0.34 m ² / g, an ignition residue of 7.21% by weight, and silica-coated metal oxide particles per unit surface area of the composite particles. the amount of addition is 0.23 g / m ^2, the adhesion amount of the silica-coated metal oxide particles per unit surface area of the composite particles was 0.21 g / m ^2.

Example 11
As the polymerizable vinyl monomer, 50 g of styrene (St) and 2.5 g of ethylene glycol dimethacrylate (EGDMA) are used instead of 50 g of methyl methacrylate (MMA) and 2.5 g of ethylene glycol dimethacrylate (EGDMA), and The amount of ultrafine silica-coated titanium oxide aqueous dispersion “GT-10W” used as the silica-coated metal oxide particles was changed to 12.7 g (a pure amount of silica-coated titanium oxide particles of 5.07 g), Composite particles were obtained in the same manner as in Example 1 except that the amount of “Metroze (registered trademark) 65SH-400” (HPMC (65SH-400)) used as the functional cellulose was changed to 0.17 g.

The obtained composite particles have a volume average particle diameter of 17.1 μm, a specific surface area of 0.34 m ² / g, an ignition residue of 8.61% by weight, and silica-coated metal oxide particles per unit surface area of the composite particles. the amount of addition is 0.28 g / m ^2, the adhesion amount of the silica-coated metal oxide particles per unit surface area of the composite particles was 0.25 g / m ^2.

Example 12
As silica-coated metal oxide particles, instead of ultrafine particle silica-coated titanium oxide aqueous dispersion “GT-10W” 10.58 g, ultrafine particle silica-coated zinc oxide “FINEX-30W” (manufactured by Sakai Chemical Industry Co., Ltd., average primary 6.82 g (particle diameter: 137 nm, silica coating amount 20 wt%) was used, and 0.13 g was used as “Metroses (registered trademark) 65SH-400” (HPMC (65SH-400)) as water-soluble celluloses. In addition, composite particles were obtained in the same manner as in Example 1 except that the rotation speed of the homomixer when finely dispersing was changed from 4000 rpm to 6200 rpm.

The obtained composite particles have a volume average particle diameter of 17.2 μm, a specific surface area of 0.35 m ² / g, an ignition residue of 12.36% by weight, and silica-coated metal oxide particles per unit surface area of the composite particles. Was 0.37 g / m ² , and the amount of silica-coated metal oxide particles deposited per unit surface area of the composite particles was 0.35 g / m ² .

Example 13
Composite particles were obtained in the same manner as in Example 1 except that “KAYAMER (registered trademark) PM-21” (PM-21) as the polymerizable phosphoric acid monomer was not used.

The obtained composite particles have a volume average particle size of 17.3 μm, a specific surface area of 0.35 m ² / g, an ignition residue of 5.95% by weight, and the amount of silica-coated metal oxide added per unit area is in 0.23 g / m ^2, the adhesion amount of the silica-coated metal oxide per unit area was 0.17 g / m ^2.

[Comparative Example 1]
Suspension polymerization was attempted in the same manner as in Example 1 except that “Metroze (registered trademark) 65SH-400” (HPMC (65SH-400)) as a water-soluble cellulose was not used. The stability of the droplets of the monomer mixture in the medium was low, and composite particles could not be obtained.

[Comparative Example 2]
In the preparation of the dispersion medium, instead of 0.14 g of “Metroze (registered trademark) 65SH-400” (HPMC (65SH-400)) as a water-soluble cellulose, “Gosenol (registered trademark) GL-05” (abbreviation “ A suspension polymerization was attempted in the same manner as in Example 1 except that 0.14 g of “GL-05” and Nippon Synthetic Chemical Industry Co., Ltd. (polyvinyl alcohol (PVA)) were used, but the monomer mixture in the dispersion medium The stability of the liquid droplets was low, and composite particles could not be obtained.

[Comparative Example 3]
Instead of 10.58 g of the ultrafine silica-coated titanium oxide aqueous dispersion “GT-10W” as silica-coated metal oxide particles, ultrafine titanium oxide “STR-100N” which is titanium oxide particles not coated with silica (堺Suspension polymerization was attempted in the same manner as in Example 1 except that 4.04 g (manufactured by Chemical Industry Co., Ltd., average primary particle size: 110 nm) was used, but the stability of the droplets of the monomer mixture in the dispersion medium was Therefore, composite particles could not be obtained.

[Comparative Example 4]
Instead of 6.82 g of ultrafine silica-coated zinc oxide “FINEX (registered trademark) -30W” as silica-coated metal oxide particles, ultrafine zinc oxide “FINEX-30” (zinc oxide particles not coated with silica) ( Changed to 1.74 g, manufactured by Sakai Chemical Industry Co., Ltd., average primary particle size: 35 nm), and the use amount of “Metroses (registered trademark) 65SH-400” (HPMC (65SH-400)) as water-soluble celluloses is 0 Suspension polymerization was attempted in the same manner as in Example 12 except that the amount was changed to .13 g. However, the stability of the droplets of the monomer mixture in the dispersion medium was low, and composite particles could not be obtained.

[Comparative Example 5]
Without using “Metroze (registered trademark) 65SH-400” (HPMC (65SH-400)) as a water-soluble cellulose, ultrafine silica-coated zinc oxide “FINEX (registered trademark) — 30W ”instead of 6.82 g, an ultrafine silica-coated zinc oxide aqueous dispersion“ FINEX-30RST ”(manufactured by Sakai Chemical Industry Co., Ltd., average primary particle size: 160 nm, solid content 50% by weight, silica coating amount 9% by weight ) Suspension polymerization was attempted in the same manner as in Example 12 except that the amount was changed to 15.92 g (pure amount of silica-coated zinc oxide particles 7.96 g), but the droplets of the monomer mixture in the dispersion medium The stability was low and composite particles could not be obtained.

[Comparative Example 6]
A process of mixing water, silica-coated metal oxide particles and water-soluble celluloses in a polymerization vessel having a stirrer and then mixing them at a temperature of 60 ° C. for 24 hours (adsorbing water-soluble celluloses on silica-coated metal oxide particles) The production of composite particles was attempted in the same manner as in Example 1 except that a dispersion medium containing water-soluble celluloses and silica-coated metal oxide particles was obtained. In addition, the particles were bonded together, and composite particles could not be obtained.

[Comparative Example 7]
4.23 g of ultrafine silica-coated titanium oxide “STR-100W” (manufactured by Sakai Chemical Industry Co., Ltd., average primary particle size: 115 nm, silica coating amount 20% by weight) as silica-coated metal oxide particles, and as polymer particles The polymethyl methacrylate particles 53.0 g having a volume average particle diameter of 16.9 μm were dispersed by a ball mill to obtain a composite in which silica-coated titanium oxide particles and polymer particles were combined.

  The resulting composite has silica-coated titanium oxide particles that are not on the surface of the polymer particles, and is placed on the surface of the polymer particles due to weak interparticle interactions (for example, electrostatic interaction), and can be easily treated by washing with water, etc. It is considered that the silica-coated titanium oxide particles that fall off from the surface of the polymer particles are included. Therefore, in order to measure the amount of silica-coated titanium oxide particles adhering to the polymer particle surface in a state that does not easily fall off from the polymer particle surface, the composite is washed with water as follows. About the obtained composite particle, the adhesion amount of a silica covering titanium oxide particle is measured.

That is, after dispersing the complex in ion-exchanged water, qualitative filter paper No. 101 (advancetech Toyo Co., Ltd. “Toyo qualitative filter paper”) was subjected to suction filtration, washed with ion-exchanged water, then drained, and then dried in an oven at 80 ° C. overnight to obtain composite particles. The ignition residue of the composite particles after drying is 3.19% by weight, the addition amount of silica-coated metal oxide particles per unit surface area of the composite particles is 0.22 g / m ² , and the silica coating per unit surface area of the composite particles The adhesion amount of metal oxide particles was 0.09 g / m ² .

[Comparative Example 8]
Instead of 4.23 g of ultrafine silica-coated titanium oxide “STR-100W” as silica-coated metal oxide particles, ultrafine titanium oxide “STR-100N”, which is titanium oxide particles not coated with silica (Sakai Chemical Industry Co., Ltd.) Composite particles were obtained in the same manner as Comparative Example 7 except that 4.04 g (manufactured by company, average primary particle size: 110 nm) was used. The ignition residue of the composite particles after drying is 3.05% by weight, the addition amount of the metal oxide particles per unit surface area of the composite particles is 0.21 g / m ² , and the metal oxide particles per unit surface area of the composite particles The adhesion amount of was 0.08 g / m ² .

  About Examples 1-13 and Comparative Examples 1-8, the usage-amount of the various raw materials used for manufacture, the measurement result of the average primary particle diameter of the metal oxide particle used for manufacture, the volume average of the composite particle obtained by manufacture Measurement results of particle diameter, specific surface area, and ignition residue, calculation result of addition amount of metal oxide particles, and calculation result of adhesion amount of metal oxide particles in composite particles obtained by manufacturing Table 1 3 shows.

From the results shown in Tables 1 to 3, the particles obtained in Examples 1 to 13 are composite particles including polymer particles and silica-coated metal oxide particles attached to the surface of the polymer particles. Admitted. Moreover, in Examples 1-13, since there is almost no difference between the addition amount of the silica-coated metal oxide particles and the adhesion amount of the silica-coated metal oxide particles, composite particles obtained by suspension polymerization It was confirmed that the silica-coated metal oxide particles were hardly removed when the was washed and drained. Therefore, the composite particles obtained in Examples 1 to 13 are those in which the silica-coated metal oxide particles are firmly attached to the surface of the polymer particles, that is, the silica-coated metal oxide particles are dropped from the surface of the polymer particles. It was recognized that it was difficult. In the composite particles obtained in Examples 1 to 13, the amount of silica-coated metal oxide particles attached per unit surface area of the composite particles was 0.10 to 1.00 g / m ² (specifically, 0.1. 15 to 0.35 g / m ² ), the composite particles of the present invention were found to have many silica-coated metal oxide particles attached to the surface of the polymer particles.

  On the other hand, in Comparative Examples 1 to 6, no composite particles could be obtained. In Comparative Example 7 and Comparative Example 8, a composite of polymer particles and silica-coated metal oxide particles (or metal oxide particles not coated with silica) is obtained, which is washed with ion-exchanged water. When the liquid is drained and dried, the amount of silica-coated metal oxide (or metal oxide particles not coated with silica) per unit area is determined by the amount of silica-coated metal oxide particles (or metal oxides not coated with silica). The amount was significantly reduced as compared with the added amount of the product particles. That is, most of the silica-coated metal oxide particles (or metal oxide particles not coated with silica) in the composites obtained in Comparative Examples 7 and 8 are easily dropped or polymer particles. It was found that it was not on the surface. In addition, the composite particles obtained by washing the composites obtained in Comparative Example 7 and Comparative Example 8 with ion-exchanged water, drying them and drying them were coated with silica in comparison with the composite particles obtained in Examples 1-13. Since the adhesion amount of metal oxide particles (or metal oxide particles not coated with silica) was remarkably small, the composite obtained in Comparative Example 7 and Comparative Example 8 was mixed with other substances to prepare an external preparation. Also, when a product such as a coating agent or a resin composition is produced, the silica-coated metal oxide particles (or the metal oxide particles not coated with silica) are compared with the composite particles obtained in Examples 1 to 13. ) Is estimated to be reduced.

Example 14
30 g of the composite particles obtained in Example 1, 100 g of acrylic polyol (trade name: Medium VM, manufactured by Dainichi Seika Kogyo Co., Ltd., resin solid content 34% by weight, solvent dispersion) as a binder resin, and a curing agent 30 g of isocyanate (trade name: VM-D, Dainichi Seika Kogyo Co., Ltd.) was mixed to obtain a coating agent. Then, after apply | coating the obtained coating agent on the polyester film with a thickness of 100 micrometers as a base material using an applicator, it dried with hot air for 10 minutes at 70 degreeC, and obtained the optical film. The measurement result of the spectral transmittance of the obtained optical film is shown in FIG.

Example 15
An optical film was obtained in the same manner as in Example 14 except that the composite particles obtained in Example 5 were used instead of the composite particles obtained in Example 1. The measurement result of the spectral transmittance of the obtained optical film is shown in FIG. In addition, in FIG. 2, the spectral transmittance | permeability of the thing (blank) only of the polyester film which has not apply | coated the coating agent is also shown collectively.

Example 16
An optical film was obtained in the same manner as in Example 14 except that the composite particles obtained in Example 6 were used instead of the composite particles obtained in Example 1. The measurement result of the spectral transmittance of the obtained optical film is shown in FIG.

Example 17
An optical film was obtained in the same manner as in Example 14 except that the composite particles obtained in Example 12 were used instead of the composite particles obtained in Example 1. The measurement result of the spectral transmittance of the obtained optical film is shown in FIG. In addition, in FIG. 3, the measurement result of the spectral transmittance | permeability of only the polyester film which has not apply | coated the coating agent (blank) is also shown.

  As apparent from FIGS. 2 and 3, the optical films of Examples 14 to 17 have sufficiently low transmittance in the wavelength region of 300 to 400 nm as compared with the blank (only the film), and sufficiently shield ultraviolet rays. It was recognized that

  The composite particles of the present invention are, for example, coating agents (coating compositions for paper), coating agents for information recording paper, or coating agents (coating compositions) used as coating agents for optical members such as optical films. For manufacturing a light diffuser (lighting cover, light diffusing plate, light diffusing film, etc.); Light diffusing agent blended in the light diffusing resin composition of the present invention; anti-blocking agent for films such as food packaging films; additives for external preparations such as cosmetics (improving slipperiness or skin and wrinkles) It can be used as a raw material for external preparations such as additives for correcting defects, UV shielding agents, etc .; materials for light confinement layers or materials for light extraction layers; abrasives; heat dissipation materials; refractive index adjusting agents, etc. is there.

Claims (18)

Polymer particles, metal oxide particles attached to the surface of the polymer particles, and water-soluble celluloses,
The composite particles, wherein the metal oxide particles are composed of silica and a metal oxide other than silica.   2. The composite particle according to claim 1, wherein the metal oxide particle is a silica-coated metal oxide particle in which a metal oxide particle other than silica is coated with silica. The adhesion amount of the metal oxide particles on the surface of the polymer particles is 0.10 to 1.00 g / m ² per unit surface area of the composite particles. Composite particles.   The composite particles according to any one of claims 1 to 3, wherein a content of silica in the metal oxide particles is 10% by weight or more.   5. The composite particle according to claim 4, wherein the content of silica in the metal oxide particle is 10 wt% or more and 50 wt% or less.   The composite particle according to any one of claims 1 to 5, wherein the water-soluble cellulose is at least one of hydroxypropylcellulose and hydroxypropylmethylcellulose.   The composite particle according to any one of claims 1 to 6, wherein the metal oxide other than silica is at least one of titanium oxide and zinc oxide.   8. The composite particle according to claim 1, wherein an average primary particle diameter of the metal oxide particles is 50 to 200 nm. It is a silica-coated metal oxide particle comprising polymer particles and metal oxide particles attached to the polymer particles, wherein the metal oxide particles are coated with metal oxide particles other than silica with silica. A method for producing composite particles, comprising:
A method for producing composite particles, comprising a polymerization step of obtaining a composite particle by subjecting a polymerizable monomer to aqueous suspension polymerization in the presence of silica-coated metal oxide particles having water-soluble cellulose adsorbed on the surface thereof . A method for producing composite particles according to claim 9,
As the water-soluble cellulose, at least one of hydroxypropylcellulose and hydroxypropylmethylcellulose is used.   Before the polymerization step, the method includes an adsorption step of treating the silica-coated metal oxide particles with the water-soluble celluloses to adsorb the water-soluble celluloses on the surface of the silica-coated metal oxide particles. The method for producing composite particles according to claim 9 or 10. It is a manufacturing method of the composite particles according to claim 11,
In the adsorption step, the silica coating is performed under a temperature condition of (T-15) ° C. (T means the lower critical solution temperature (° C.) or cloud point (° C.) of the water-soluble cellulose). A method for producing composite particles, wherein the metal oxide particles and the water-soluble cellulose coexist and the water-soluble celluloses are adsorbed on the surface of the silica-coated metal oxide particles. The method for producing composite particles according to any one of claims 9 to 12, wherein the amount of the silica-coated metal oxide particles used is 0.10 to 1.50 g / m ² per unit surface area of the composite particles. .   An external preparation comprising the composite particles according to any one of claims 1 to 8.   The coating agent characterized by including the composite particle of any one of Claims 1-8.   An optical film obtained by applying the coating agent according to claim 15 to a substrate.   A resin composition comprising the composite particles according to claim 1 and a base resin.   A molded article obtained by molding the resin composition according to claim 17.