WO2020031079A1

WO2020031079A1 - Organic inorganic composite particle, method for producing same, and application thereof

Info

Publication number: WO2020031079A1
Application number: PCT/IB2019/056673
Authority: WO
Inventors: 松浦春彦; 前山洋輔
Original assignee: 積水化成品工業株式会社
Priority date: 2018-08-09
Filing date: 2019-08-06
Publication date: 2020-02-13

Abstract

The present invention provides: organic inorganic composite particles that exhibit excellent reflectivity of visible light and near-infrared light and that have high light diffusing ability and concealing ability; and a method for producing the organic inorganic composite particles; and application of the organic inorganic composite particles. More specifically, the present invention pertains to organic inorganic composite particles characterized by having a volume average particle diameter of 0.5-100 μm and each comprising: a porous structure that is provided with an outer shell composed of a crosslinked polymer and a cavity defined by the outer shell, and in which silica particles as first inorganic particles are mutually linked inside the cavity; and second inorganic particles other than the silica particles. The present invention also pertains to: a method for producing such organic inorganic composite particles; and application of such organic inorganic composite particles.

Description

Organic-inorganic composite particles, production method thereof and use thereof

The present invention relates to organic-inorganic composite particles, a method for producing the same, and uses thereof. Specifically, the organic-inorganic composite particles of the present invention have a unique shape, and make use of the characteristics thereof, such as cosmetics, coating compositions, heat-insulating resin compositions, light-diffusing resin compositions, and light-diffusing films. Suitable for applications such as
This application filed Japanese Patent Application No. 2018-150712 filed on Aug. 9, 2018, Japanese Patent Application No. 2018-150714 filed on Aug. 9, 2018, and filed on Jul. 18, 2019. Priority is claimed based on Japanese Patent Application No. 2019-132979 and Japanese Patent Application No. 2019-133837 filed on Jul. 19, 2019, the contents of which are incorporated herein by reference.

Conventionally, in applications such as cosmetics, coating compositions, heat-insulating resin compositions, light-diffusing resin compositions, and light-diffusing films, improvements in tactile sensation, soft focus effects, matting properties, light-diffusing properties, etc. are provided. To do so, inorganic particles such as resin particles, silica particles, glass particles, titanium oxide, aluminum oxide, and calcium carbonate are used as additives.
As specific additives, for example, hollow resin particles have been proposed (see Patent Documents 1 and 2).
In addition, a method of obtaining microcapsule particles containing single or plural silica particles by applying a microparticle-size hollow particle synthesis method to produce microcapsule particles containing silica precursor and then performing a sol-gel reaction. Has been proposed (see Non-Patent Document 1).

However, the microcapsule particles containing the hollow resin particles of Patent Documents 1 and 2 and the single or plural silica particles of Non-Patent Document 1 do not have sufficient light scattering properties due to the internal space, for example. There is a problem that it is insufficient to obtain excellent light diffusion and hiding properties, and excellent reflectivity of visible light and near-infrared light when added to a resin composition such as a paint.
Accordingly, the present applicant has reported that the above-mentioned problems can be solved by using organic-inorganic composite particles having a shell composed of a crosslinked polymer and containing silica having a porous structure inside the capsule. (See Patent Document 3).

JP 2009-237342 A International Publication No. 2014/030754 WO 2017/150423

However, although the organic-inorganic composite particles of Patent Document 3 have high light diffusivity, it has been desired to provide organic-inorganic composite particles having higher light diffusivity. Further, in Patent Document 3, an organic-inorganic composite particle is produced using an organic solvent as a porogen for forming a porous structure composed of silica particles inside a capsule. From the viewpoint of the influence on the manufacturer at the time of manufacture, it is desirable to use as little as possible. Therefore, it has been desired to provide a method for producing organic-inorganic composite particles without using an organic solvent.
Then, an object of the present invention is to provide organic-inorganic composite particles which are excellent in the reflectivity of visible light and near-infrared light, have high light diffusivity and opacity, a method for producing the same, and uses thereof.

The present inventors have proposed that organic-inorganic composite particles having an outer shell composed of a crosslinked polymer and containing silica having a porous structure inside the capsule, further containing particles made of an inorganic substance other than silica inside the capsule. It has been found that the above problem can be solved by doing so. In addition, the present inventors have found that by adding an inorganic thickener to a monomer mixture, organic-inorganic composite particles can be produced without using an organic solvent, and have led to the present invention.
Specifically, according to the present invention, an outer shell composed of a crosslinked polymer and a cavity defined by the outer shell are provided, and silica particles as first inorganic particles are mutually contained inside the hollow. An organic-inorganic composite particle comprising a connected porous structure and second inorganic particles other than silica particles, and having a volume average particle diameter of 0.5 to 100 μm is provided.
Further, according to the present invention, the method for producing the organic-inorganic composite particles, wherein the radical polymerizable monofunctional monomer 100 parts by weight and the crosslinkable monomer 20 to 150 parts by weight, as a silica precursor A mixture containing 60 to 400 parts by weight of silicon alkoxide and 0.1 to 10 parts by weight of the second inorganic particles is subjected to suspension polymerization in an aqueous medium in the presence of a radical polymerization initiator to form a crosslinked polymer. Forming a shell defined by the outer shell, and gelling silicon alkoxide after or simultaneously with the formation of the outer shell, thereby forming silica particles inside the hollow. And forming a porous structure connected to each other.
Furthermore, according to the present invention, a mixture containing a radically polymerizable monofunctional monomer and a crosslinkable monomer, a silicon alkoxide as a silica precursor, and an inorganic thickener, a radical polymerization initiator A step of forming an outer shell composed of a crosslinked polymer by suspension polymerization in an aqueous medium in the presence and in the absence of an organic solvent, and forming a silicon alkoxide after forming the outer shell or simultaneously with forming the outer shell. Forming a porous structure in which silica particles are connected to each other inside the outer shell, thereby providing a method for producing organic-inorganic composite particles.
Further, according to the present invention, there is provided a cosmetic containing the organic-inorganic composite particles.
Further, according to the present invention, there is provided a coating composition containing the organic-inorganic composite particles.
Further, according to the present invention, there is provided a heat-insulating resin composition containing the organic-inorganic composite particles.
Further, according to the present invention, there is provided a light-diffusing resin composition containing the organic-inorganic composite particles.
Further, according to the present invention, there is provided a light diffusion film in which the organic-inorganic composite particles are blended.

According to the present invention, organic-inorganic composite particles excellent in reflectivity of visible light and near-infrared light, exhibiting high light diffusion and hiding properties, and cosmetics and coating compositions containing the organic-inorganic composite particles , A heat-insulating resin composition, a light-diffusing resin composition, and a light-diffusing film.

Further, in any of the following cases, it is possible to provide organic-inorganic composite particles having remarkable effects such as more excellent light diffusing properties and hiding properties, and near-infrared light reflectivity.
(1) The second inorganic particles have a refractive index of 1.8 or more.
(2) The second inorganic particles have a particle size of 0.001 to 3 μm measured by a dynamic light scattering method.
(3) The first inorganic particles and the second inorganic particles have 5 to 50% by weight with respect to the total weight of the organic-inorganic composite particles, and provide a hollow structure to the cavity.
(4) The second inorganic particles are particles selected from titanium oxide, zirconium oxide, cerium oxide, zinc oxide, niobium oxide, and zirconium silicate.

Furthermore, in the following cases, organic-inorganic composite particles exhibiting remarkable effects of more excellent light diffusion and hiding properties and near-infrared light reflectivity can be more easily produced.
(1) Gelation is performed using an acid or a base in a cavity defined by an outer shell as a catalyst, and the acid or the base is generated by an external stimulus caused by energy radiation or heat of the latent pH adjuster, and the latent pH is adjusted. An agent is present in the cavity by dissolving the latent pH adjuster in the mixture during suspension polymerization.

In addition, in any of the following cases, organic-inorganic composite particles that are more excellent in the reflectivity of visible light and near-infrared light and have higher light diffusivity can be more easily produced without using an organic solvent.
(1) The mixture has a viscosity of 0.90 mPa · s or more at 25 ° C.
(2) The inorganic thickener is silicic anhydride or clay mineral.
(3) The porous structure in which the silica particles are connected to each other shows that the carbon component is contained in the EDX measurement.
(4) The inorganic thickener is hydrophobic silica particles of silicic anhydride, and the hydrophobic silica particles have a specific surface area of 15 to 330 m ² / g by a BET method.
(5) The organic-inorganic composite particles have a volume average particle diameter of 0.5 to 100 μm.
(6) The porous structure has 5 to 50% by weight based on the total weight of the organic-inorganic composite particles.
(7) The hydrophobic silica particles are contained in an amount of 0.5 to 100 parts by weight based on 100 parts by weight of the mixture.
(8) The mixture contains 100 parts by weight of the monofunctional monomer, 20 to 150 parts by weight of the crosslinkable monomer, and 60 to 400 parts by weight of the silica precursor.

FIG. 3 is a surface photograph, a cross-sectional photograph, and a SEM-EDS mapping diagram of the organic-inorganic composite particles of Example 1. 5 is a surface photograph and a cross-sectional photograph of the organic-inorganic composite particles of Example 2. 9 is a surface photograph and a sectional photograph of the organic-inorganic composite particles of Example 3. 9 is a surface photograph and a cross-sectional photograph of the organic-inorganic composite particles of Example 4. 4 is a surface photograph and a cross-sectional photograph of the organic-inorganic composite particles of Comparative Example 1. 9 is a surface photograph and a cross-sectional photograph of the organic-inorganic composite particles of Comparative Example 2. 4 is a graph showing the light reflectance for each wavelength of a coating film containing various particles in the evaluation of the reflection characteristics of ultraviolet, visible, and near infrared light. It is a figure which shows an example of the analysis area | region set as an internal porous part in the photograph of a particle cross section. 9 is a surface photograph and a cross-sectional photograph of the organic-inorganic composite particles of Example 5. 9 is a surface photograph and a cross-sectional photograph of the organic-inorganic composite particles of Example 6. 9 is a surface photograph and a cross-sectional photograph of the organic-inorganic composite particles of Example 7. 9 is a surface photograph and a sectional photograph of the organic-inorganic composite particles of Example 8. 9 is a surface photograph and a sectional photograph of the organic-inorganic composite particles of Example 10. 9 is a surface photograph and a sectional photograph of the organic-inorganic composite particles of Example 11. 9 is a surface photograph and a sectional photograph of the organic-inorganic composite particles of Example 12. 14 is a cross-sectional photograph of the organic-inorganic composite particles of Example 14. 14 is a cross-sectional photograph of the organic-inorganic composite particles of Example 15. 9 is a surface photograph and a cross-sectional photograph of the organic-inorganic composite particles of Comparative Example 3. 4 is a graph showing the light reflectance for each wavelength of a coating film containing various particles in the evaluation of the reflection characteristics of ultraviolet, visible, and near infrared light.

Hereinafter, the present invention will be described in detail. Note that the present invention is not limited to the embodiment described here, and various changes can be made without departing from the spirit of the present invention.

(Organic-inorganic composite particles)
The organic-inorganic composite particles of the present invention (hereinafter also referred to as “composite particles”) have an outer shell made of a crosslinked polymer. Further, the composite particles may include a cavity defined by an outer shell. Further, the composite particles include a porous structure in which silica particles (hereinafter, also referred to as “first inorganic particles”) are connected to each other in an outer shell or a cavity. Further, the composite particles may include particles made of an inorganic substance other than silica (hereinafter, also referred to as “second inorganic particles”) inside the outer shell or the cavity. Further, the composite particles have a volume average particle size of 0.5 to 100 μm. The composite particles are sometimes referred to as composite fine particles.

(1) Outer Shell The type of the crosslinked polymer is not particularly limited as long as it can constitute the outer shell. The crosslinking polymers include polymers derived from radical polymerizable monomers, specifically, a monofunctional monomer having one vinyl group, the crosslinkable monomer having two or more vinyl groups And copolymers thereof.
Examples of the monofunctional monomer having one vinyl group include alkyl (meth) acrylates having 1 to 16 carbon atoms such as methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, and cetyl (meth) acrylate. ) Acrylate; (meth) acrylonitrile, dimethyl maleate, dimethyl fumarate, diethyl fumarate, ethyl fumarate, maleic anhydride, N-vinylcarbazole; styrene, α-methylstyrene, paramethylstyrene, vinyltoluene, chlorostyrene, Styrene-based monomers such as ethyl styrene, i-propyl styrene, dimethyl styrene and bromo styrene are exemplified. These monofunctional monomers can be used alone or in combination of two or more.

Examples of the crosslinkable monomer having two or more vinyl groups include polyfunctional acrylic esters such as ethylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, and glycerin tri (meth) acrylate; Polyfunctional acrylamide derivatives such as -methylenebis (meth) acrylamide and N, N'-ethylenebis (meth) acrylamide; polyfunctional allyl derivatives such as diallylamine and tetraallyloxyethane; and aromatic divinyl compounds such as divinylbenzene. No. These crosslinkable monomers can be used alone or in combination.

The crosslinkable monomer is preferably contained in the outer shell at a ratio of 20 parts by weight or more based on 100 parts by weight of the monofunctional monomer. When the content of the crosslinking monomer is less than 20 parts by weight, an outer shell having sufficient strength may not be formed. The content is more preferably from 20 to 150 parts by weight, and even more preferably from 80 to 120 parts by weight.

(2) Porous structure The porous structure has a configuration in which silica particles are connected to each other. Here, the porous structure means a structure in which some of the plurality of silica particles are connected to each other, and a macroporous space is formed between the silica particles in an unconnected portion. It is preferable that the porous structure has a volume in the range of the ratio to the total volume of the cavities described in the columns of various physical properties below.
Furthermore, the individual silica particles are mainly composed of SiO _2. Silica particles can be obtained, for example, by gelling a silica precursor. Examples of the silica precursor include a silicon alkoxide having one or more silicon atoms and an alkoxy group (for example, having 1 to 4 carbon atoms) in the same molecule. Specific examples include tetraethoxysilane (TEOS), tetramethoxysilane, tetrapropoxysilane, and the like. In addition, methyl silicate oligomer (MKC silicate, trade name, manufactured by Mitsubishi Chemical Corporation) which is a partially hydrolyzed oligomer of tetramethoxysilane, and ethyl silicate oligomer (product name, silicate 45, manufactured by Tama Chemical Co., Ltd.) which is a partially hydrolyzed oligomer of tetraethoxysilane (Pentamer), silicate 48 (10-mer)), and oligomers such as siloxane oligomers. These silica precursors can be used alone or in combination of two or more. Among them, tetraethoxysilane is preferable as the monofunctional silica precursor, and ethylsilicate oligomer is preferable as the silica precursor which is an oligomer.
The porous structure is preferably present on the inner wall of the outer shell in order to provide the composite particles with excellent light diffusion and hiding properties.
The silica precursor is preferably contained in the mixture at a ratio of 60 to 400 parts by weight based on 100 parts by weight of the monofunctional monomer. When the content of the silica precursor is less than 60 parts by weight, particles having sufficient optical performance may not be obtained. When the content is more than 400 parts by weight, the components of the outer shell are relatively reduced, so that particles having sufficient strength may not be obtained. The content is more preferably 70 to 270 parts by weight, further preferably 80 to 250 parts by weight. In addition, the content ratio of the monofunctional monomer-derived component and the silica precursor-derived component in the composite particles substantially matches the above-mentioned ratio of the monofunctional monomer and the silica precursor.
The porous structure may contain a crosslinked polymer component, and the crosslinked polymer component may be a crosslinked polymer component forming an outer shell.
In addition, the porous structure may include a carbon component indicated by EDX measurement using SEM-EDX.

(3) Second inorganic particle The second inorganic particle is not particularly limited as long as it is a particle made of an inorganic substance having a composition other than silica. Examples of the second inorganic particles include particles such as titanium oxide, zirconium oxide, cerium oxide, zinc oxide, niobium oxide, and zirconium silicate. Titanium oxide may be surface-treated with alumina, silica, or the like. These second inorganic particles can be used alone or in combination.
The second inorganic particles preferably have a refractive index of 1.8 or more. When the refractive index is less than 1.8, a sufficient effect of improving light diffusibility may not be obtained. The refractive index is more preferably from 2.0 to 4.0.
Examples of the inorganic particles having a refractive index of 1.8 or more include particles of titanium oxide, zirconium oxide, cerium oxide, zinc oxide, niobium oxide, zirconium silicate, and the like. The inorganic particles are preferably titanium oxide, zirconium oxide, and cerium oxide.
The method for measuring the refractive index is not particularly limited. For example, as for the measuring method, the measurement is performed with reference to pages 635 to 640 of “Introduction to Ceramics Material Science (Applied Edition), Issued by Uchida Lao Tsuruho Shinsha, Issued on May 25, 1981”. And known methods (for example, the minimum declination method, the critical angle method, the V-block method, etc.). The refractive index means a relative refractive index to air. A reference wavelength of 550 nm can be used for the measurement.

The second inorganic particles preferably have a particle size of 0.001 to 3 μm measured by a dynamic light scattering method. If the particle size is larger than 3 μm, the particles may settle during polymerization, and the desired particles may not be obtained. If the particle size is less than 0.001 μm, particles can be produced but sufficient light reflection performance may not be obtained. The particle size is more preferably 0.001 to 1 μm.
The surface of the second inorganic particles may be treated with a surface treating agent to improve dispersibility in the composite particles. Examples of the surface treatment include water repellent treatment such as silicon treatment, silane coupling treatment, and polymer treatment.

(4) Weight of first inorganic particles and second inorganic particles The first inorganic particles and the second inorganic particles preferably have 5 to 50% by weight based on the total weight of the composite particles. . When the weight of the first inorganic particles and the second inorganic particles is less than 5% by weight, the formation of the porous body by the silica may be insufficient. When the weight is more than 50% by weight, the ratio of the outer shell is relatively reduced, and the strength may not be sufficient. The weight of these inorganic particles is more preferably from 10 to 45% by weight.
The second inorganic particles are preferably contained in the composite particles in the range of 0.01 to 5 parts by weight, where the total amount of the first inorganic particles and the second inorganic particles is 100 parts by weight. When the content is less than 0.01 part by weight, a sufficient effect of improving light diffusibility may not be obtained. If the content is more than 5 parts by weight, the polymerization reaction of the particles may not proceed well. The content is more preferably in the range of 0.05 to 2.5 parts by weight.
The weight of the first inorganic particles and / or the second inorganic particles contained in the composite particles can be measured by X-ray fluorescence measurement.

(5) Properties of composite particles

(A) Volume Average Particle Size The composite particles preferably have a volume average particle size of 0.5 to 100 μm. When the volume average particle diameter is less than 0.5 μm, it may be difficult to obtain fine capsule particles. When the volume average particle diameter is larger than 100 μm, the production may be difficult due to the collapse of the capsule particles. The volume average particle size is preferably from 3 to 80 μm, more preferably from 5 to 50 μm, depending on the use.

(B) Apparent specific gravity When the outer shell is non-porous, the composite particles preferably have an apparent specific gravity of 0.3 to 1.0 g / cm ³ . When the apparent specific gravity is less than 0.3 g / cm ³ , the resin layer of the outer shell is thin and the strength may be reduced. If the apparent specific gravity is greater than 1.0 g / cm ^3, there is the effect due to the porous structure consisting of the interior of the silica may not be sufficiently exhibited. The apparent specific gravity is preferably from 0.3 to 0.9 g / cm ³ .

(C) Outer Shape, etc. The outer shape of the composite particles is not particularly limited, but is preferably as close to spherical as possible.
The thickness of the outer shell is preferably 5 to 40% of the volume average particle diameter. When the thickness of the outer shell is less than 5% of the volume average particle diameter, the outer shell may not have sufficient strength. When the thickness of the outer shell is larger than 40% of the volume average particle diameter, the effect of the inner silica structure may be insufficient. The thickness of the outer shell is more preferably 10 to 30% of the volume average particle diameter.
The outer shell may be porous. By being porous, improvement in the strength of the particles themselves can be expected as compared with general silica porous resin particles, and particles that are difficult to collapse can be provided. Further, the porosity can be improved. In addition, general porous resin particles are made porous by using a large amount of a porogen (solvent), so that it is necessary to use a large amount of a porogen to obtain fine particles having a large oil absorption. There is a problem that the property is remarkably reduced. On the other hand, in the particles of the present invention, the porosity can exceed 90% in the porous structure made of silica inside the microcapsules without using a large amount of the porogen. The degree of porosity can be defined by the amount of oil absorption. The oil absorption is preferably from 150 to 500 ml / 100 g. It is also possible to define the degree of porosity by other indices such as pore diameter and pore volume.

The porous structure preferably has 5 to 50% by weight based on the total weight of the composite particles. When the weight of the porous structure is less than 5%, formation of the porous body by silica may be insufficient. When the weight of the porous structure is more than 50%, the ratio of the outer shell is relatively reduced, and the strength may not be sufficient. The weight of the porous structure is preferably from 10 to 45% by weight.

(Method for producing organic-inorganic composite particles)
The method for producing organic-inorganic composite particles according to the first embodiment of the present invention includes a method for preparing a single particle in a mixture containing a silica precursor emulsified and dispersed in an aqueous medium, second inorganic particles, and a radical polymerizable monomer. "Polymerization step" of obtaining a microcapsule containing a silica precursor and second inorganic particles by subjecting the monomer to suspension polymerization, and "gel" Process ".

(1) Polymerization Step In the polymerization step, first, a mixture containing a silica precursor, second inorganic particles, and a monomer is dispersed in an aqueous medium by emulsification. The amount of the monomer used and the content of the component derived from the monomer constituting the outer shell substantially match.
As the second inorganic particles, the particles themselves may be dispersed in an aqueous medium, or a solution in which the particles are previously dispersed in a solvent may be dispersed in an aqueous medium. A thickener may be added to this solution. Examples of the thickener include organic thickeners such as acrylic thickeners, urethane thickeners, polyether thickeners, polyvinyl alcohols, and cellulose derivatives. Examples of the inorganic thickener include a clay mineral. Examples of the clay mineral include natural clays such as bentonite, montmorillonite, saponite, beidellite, hectorite, stevensite, sauconite, nontronite, etc., vermiculite, halloysite, swelling mica, zeolite, attapulgite and other natural clays, or synthetic clays. Can be These may contain only one kind or two or more kinds.
The emulsification and dispersion are not particularly limited, and are performed while appropriately adjusting various conditions such as a stirring speed and a stirring time so as to obtain composite particles having a desired particle size.

The polymerization of the monomer is preferably performed in the presence of a radical polymerization initiator. The radical polymerization initiator is not particularly limited, and examples thereof include persulfates such as ammonium persulfate, potassium persulfate, and sodium persulfate, cumene hydroperoxide, di-tert-butyl peroxide, dicumyl peroxide, and benzoyl peroxide. Oxide, lauroyl peroxide, dimethylbis (tert-butylperoxy) hexane, dimethylbis (tert-butylperoxy) hexyne-3, bis (tert-butylperoxyisopropyl) benzene, bis (tert-butylperoxy) trimethyl Cyclohexane, butyl-bis (tert-butylperoxy) valerate, tert-butyl 2-ethylhexaneperoxyate, dibenzoyl peroxide, paramenthane hydroperoxide, and tert- Organic peroxides such as tilperoxybenzoate, 2,2′-azobis [2- (2-imidazolin-2-yl) propane] dihydrochloride, and 2,2′-azobis [2- (2-imidazoline- 2-yl) propane] disulfate dihydrate, 2,2′-azobis (2-amidinopropane) dihydrochloride, 2,2′-azobis [N- (2-carboxyethyl) -2-methylpropion Amidine] hydrate, 2,2′-azobis {2- [1- (2-hydroxyethyl) -2-imidazolin-2-yl] propane} dihydrochloride, 2,2′-azobis [2- (2 -Imidazolin-2-yl) propane], 2,2′-azobis (1-imino-1-pyrrolidino-2-ethylpropane) dihydrochloride, 2,2′-azobis {2-methyl-N- [1, 1-bis (hydroxymethyl) -2 Hydroxyethyl] propionamide], 2,2′-azobis [2-methyl-N- (2-hydroxyethyl) propionamide], 4,4′-azobis (4-cyanopentanoic acid), 2,2′-azo Bisisobutyronitrile, 2,2'-azobis (2-methyl-butyronitrile), 2,2'-azobis (2-isopropylbutyronitrile), 2,2'-azobis (2,3-dimethylbutyronitrile) ), 2,2'-azobis (2,4-dimethylbutyronitrile), 2,2'-azobis (2-methylcapronitrile), 2,2'-azobis (2,3,3-trimethylbutyro Nitrile), 2,2'-azobis (2,4,4-trimethylvaleronitrile), 2,2'-azobis (2,4-dimethylvaleronitrile), 2,2'-azobis (2,4-dimethyl Tyl-4-ethoxyvaleronitrile), 2,2′-azobis (2,4-dimethyl-4-n-butoxyvaleronitrile), 2,2′-azobis (4-methoxy-2,4-dimethylvaleronitrile) , 2,2'-azobis [N- (2-propenyl) -2-methylpropionamide], 2,2'-azobis (N-butyl-2-methylpropionamide), 2,2'-azobis (N- Cyclohexyl-2-methylpropionamide), 1,1′-azobis (1-acetoxy-1-phenylethane), 1,1′-azobis (cyclohexane-1-carbonitrile), dimethyl-2,2′-azobis ( 2-methylpropionate), dimethyl-2,2'-azobisisobutyrate, dimethyl-2,2'-azobis (2-methylpropinate), 2- (carba Ylazo) isobutyronitrile, 4,4'-azobis (4-cyanovaleric acid) azo compounds such like. These polymerization initiators can be used alone or in combination of two or more.

The polymerization initiator is preferably contained in the mixture in an amount of 0.05 to 5 parts by weight based on 100 parts by weight of the monomer.
Examples of the aqueous medium include water, a mixture of water and a water-soluble organic solvent (for example, a lower alcohol such as methanol and ethanol), and the like.
Further, the polymerization may be performed in the presence of a non-reactive organic solvent. As the non-reactive organic solvent, for example, pentane, hexane, cyclohexane, heptane, decane, hexadecane, toluene, xylene, ethyl acetate, butyl acetate, methyl ethyl ketone, methyl isobutyl ketone, 1,4-dioxane, methyl chloride, methylene chloride, Chloroform, carbon tetrachloride and the like can be mentioned. These non-reactive organic solvents can be used alone or in combination.
The addition amount of the non-reactive solvent is not particularly limited, but is 0 to 300 parts by weight based on 100 parts by weight of the monomer. If it exceeds 300 parts by weight, the outer shell may be insufficiently formed.
In the present invention, in order to obtain composite particles having a non-porous outer shell, the non-reactive organic solvent may be used in an amount of 10 to 50 parts by weight based on 100 parts by weight of the monomer. Although it depends on the kind of the solvent to be used, if it exceeds 50 parts by weight, it becomes easy to obtain composite particles having a porous outer shell.

Furthermore, by performing the polymerization in the presence of an alkoxide compound of titanium, zirconium or aluminum having a higher hydrolyzability than silicon alkoxide, a porous structure can be easily formed in the capsule. When these alkoxide compounds are used, it is not necessary to use a non-reactive organic solvent. That is, since these compounds are more hydrolyzable than silica precursors such as silicon alkoxides, they gel in microcapsules, suppress the movement of silica precursors in microcapsules, and promote porosity. The present inventors believe that the above-mentioned effect is obtained.
Examples of the titanium alkoxide compound include isopropyl triisostearoyl titanate, isopropyl tristearoyl titanate, isopropyl trioctanoyl titanate, isopropyl dimethacryl isostearyl titanate, isopropyl tridodecylbenzenesulfonyl titanate, isopropyl isostearoyl diacryl titanate, and isopropyl tri ( Dioctyl phosphate) titanate, isopropyl tricumyl phenyl titanate, isopropyl tris (dioctyl pyrophosphate) titanate, isopropyl tri (n-aminoethyl-aminoethyl) titanate, tetraisopropyl bis (dioctyl phosphite) titanate, tetraoctyl bis (ditridecyl phosphate) Fight) Titanate, Tet (2,2-diallyloxymethyl-1-butyl) bis (ditridecyl) phosphite titanate, dicumylphenyloxyacetate titanate, bis (dioctylpyrophosphate) oxyacetate titanate, diisostearoylethylene titanate, bis (dioctylpyrophosphate) Ethylene titanate, bis (dioctyl pyrophosphate) diisopropyl titanate, tetramethyl orthotitanate, tetraethyl orthotitanate, tetrapropyl orthotitanate, tetraisopropyltetraethyl orthotitanate, tetrabutyl orthotitanate, butyl polytitanate, tetraisobutyl orthotitanate, 2-ethylhexyl titanate , Stearyl titanate, cresyl titanate monomer, kureshi Titanate polymer, diisopropoxy-bis- (2,4-pentadionate) titanium (IV), diisopropyl-bis-triethanolaminotitanate, octylene glycol titanate, titanium lactate, acetoacetate ester titanate, diisopropoxy bis 8-acetylacetonato) titanium, di-n-butoxybis (triethanolaluminate) titanium, dihydroxybis (lactato) titanium, titanium-isopropoxyoctylene glycolate, tetra-n-butoxytitanium polymer, tri-n-butoxytitanium Monostearate polymer, butyl titanate dimer, titanium acetylacetonate, polytitanium acetylacetonate, titanium octylene glycolate, titanium lactate ammonium salt, titanium Examples include tan lactate ethyl ester, titanium triethanol aminate, and polyhydroxytitanium stearate.

Examples of zirconium alkoxide compounds include zirconium butyrate, zirconium acetylacetonate, acetylacetone zirconium butyrate, zirconium lactate, zirconium stearate butyrate, tetra (triethanolamine) zirconate, and tetraisopropyl zirconate.
Examples of aluminum alkoxide compounds include acetoalkoxyaluminum diisopropylate, ethyl acetoacetate aluminum diisopropylate, aluminum tris (ethylacetoacetate), alkyl acetoacetate aluminum diisopropylate (alkyl has 1 to 20 carbon atoms), Aluminum monoacetylacetonate bis (ethylacetoacetate), aluminum tris (acetylacetonate) and the like can be mentioned.
These alkoxide compounds can be used alone or in combination of two or more.
The amount of the alkoxide compound is not particularly limited, but is not more than 10 parts by weight based on 100 parts by weight of the monomer. When the amount exceeds 10 parts by weight, particles may not be obtained because sufficient dispersion stability of droplets cannot be maintained when the monomer mixture is suspended and emulsified in an aqueous medium.
Here, compared to the non-reactive organic solvent or silicon alkoxide, when not adding a highly hydrolyzable titanium, zirconium or aluminum alkoxide compound, or when not adding a thickener, the inside of the microcapsule Single or plural spherical silica particles are produced, and it is not possible to obtain resin particles having a porous structure made of silica inside the microcapsules intended for the present invention.

Next, the emulsified and dispersed mixture is subjected to polymerization of the monomers therein to form microcapsules containing a silica precursor therein. The polymerization is not particularly limited, and is performed while appropriately adjusting various conditions such as a polymerization temperature and a polymerization time according to the types of the monomer and the polymerization initiator contained in the mixture. For example, the polymerization temperature can be 30 to 80 ° C., and the polymerization time can be 1 to 20 hours.

(2) Gelation Step In the gelation step, the silica precursor in the microcapsules present in the emulsion is converted into silica particles by a gelation reaction, whereby composite particles are obtained. The gelation reaction is preferably performed while maintaining the emulsion at an alkaline level (eg, pH 7 or higher, specifically pH 10 to 14). The alkalinity can be maintained by adding a base such as an aqueous ammonia solution, sodium hydroxide, or potassium hydroxide to the emulsion. The amount of the base to be added is preferably 1 to 10 equivalents to the silica precursor.
The gelation step is not particularly limited, and can be performed under conditions (temperature, time, stirring speed, and the like for gelation) necessary for the silica precursor to gel to become silica particles. For example, the gelling temperature can be 30 to 80 ° C., and the gelling time can be 1 to 24 hours.
The gelation step may be performed in the presence of a latent pH adjuster. The coexistence of the latent pH adjuster makes it possible to reduce the amount of base added to the emulsion. For example, when ammonia is used as a base, and when a latent pH adjuster is present, gelation can be performed efficiently even if the amount of ammonia is reduced to 3 equivalents or less (for example, ammonia not used, 0.01 to 3 equivalents). It can be performed. Since the number of bases can be reduced, there is an effect that workability during production can be improved. The amount of the latent pH adjuster varies depending on the type of the agent, production conditions, and the like, but is preferably, for example, 0.01 to 10 parts by weight based on 100 parts by weight of the silica precursor. The use amount is more preferably 0.1 to 5 parts by weight.
The latent pH adjuster includes a substance that generates an acid or a base by an external stimulus such as irradiation with energy radiation or heating. Energy radiation includes infrared rays, visible light, ultraviolet rays, and the like.

Hereinafter, specific examples of the latent pH adjuster will be described.
(I) Examples of latent pH adjusters (thermal acid generators) that generate an acid upon heating include aryldiazonium salts, sulfonium salts, iodonium salts, ammonium salts, phosphonium salts, oxonium salts, iron-allene complexes, and aromatics Aromatic silanol / ammonium complex, diallyliodonium salt-dibenzyloxy copper, imidazole derivative, benzylsulfonium salt, hemiacetal ester, sulfonic acid ester and the like.
Also, for example, dicyandiamide, cyclohexyl p-toluenesulfonate, diphenyl (methyl) sulfonium tetrafluoroborate, 4-hydroxyphenylbenzylmethylsulfonium tetrakis (pentafluorophenyl) borate, (4-acetoxyphenyl) benzylmethylsulfonium tetrakis (pentafluoro Phenyl) borate, 4-hydroxyphenylbenzylmethylsulfonium hexafluoroantimonate, 4-acetoxyphenylbenzylmethylsulfonium hexafluoroantimonate, triphenylsulfonium hexafluoroantimonate, triphenylsulfonium hexafluorophosphonate, di-tert-butylphenyliodonium Hexafluorophosphonate, triaryl sulf Hexafluorophosphonate, bis (4-tert-butylphenyl) iodonium hexafluorophosphate, bis (4-fluorophenyl) iodonium trifluoromethanesulfonate, cyclopropyldiphenylsulfonium tetrafluoroborate, diphenyliodonium hexafluoroarsenate, diphenyliodonium trifluoro Lomethanesulfonic acid, 2- (3,4-dimethoxystyryl) -4,6-bis (trichloromethyl) -1,3,5-triazine, 2- [2- (furan-2-yl) vinyl] -4, 6-bis (trichloromethyl) -1,3,5-triazine, 4-isopropyl-4′-methyldiphenyliodonium tetrakis (pentafluorophenyl) borate, 2- [2- (5-methylfuran-2 Yl) vinyl] -4,6-bis (trichloromethyl) -1,3,5-triazine, 2- (4-methoxyphenyl) -4,6-bis (trichloromethyl) -1,3,5-triazine, 4-nitrobenzenediazonium tetrafluoroborate, (4-nitrophenyl) (phenyl) iodonium trifluoromethanesulfonate, triphenylsulfonium tetrafluoroborate, triphenylsulfonium bromide, tri-p-tolylsulfonium hexafluorophosphate, tri-p- Tolylsulfonium trifluoromethanesulfonate, (1R, 2S, 5R) -5-methyl-2- (propan-2-yl) cyclohexyl 4-methylbenzenesulfonate, bis [4-n-alkyl (C10-13) phenyl) iodonium hexa H Oro phosphate, cyclohexyl 4-methylbenzenesulfonate and the like.
Moreover, you may use a commercial item. For example, "San Aid SI-60L, SI-100L, SI-150L" manufactured by Sanshin Chemical Co., Ltd., "TPS", "DBPI" manufactured by Midori Kagaku Co., Ltd., "UVI-6990" manufactured by Dow Chemical Company, "Irgacure 261" manufactured by Ciba Geigy Co., Ltd. And the like.

(Ii) Examples of the latent pH adjuster (thermal base generator) that generates a base upon heating include 1,2-diisopropyl-3- [bis (dimethylamino) methylene] guadinium 2- (3-benzoylphenyl) Propionate, 1,2-dicyclohexyl-4,4,5,5-tetramethylbiguadinium n-butyltriphenylborate, (Z)-{[bis (dimethylamino) methylidene] amino} -N-cyclohexyl (cyclohexylamino ) Methaniminium tetrakis (3-fluorophenyl) borate, acetophenone O-benzoyloxime, 1,2-bis (4-methoxyphenyl) -2-oxoethyl cyclohexylcarbamate, 1,4-dihydro-2,6-dimethyl- 4- (2-nitrophenyl) -3,5-pyridinedical Dimethyl phosphate, 2-nitrobenzyl cyclohexylcarbamate, 1,5,7-triazabicyclo [4.4.0] dec-5-ene 2- (2- (9-oxoxanthen-2-yl) propionate ( 9-oxoxanthen-2-yl) propionate 1,5,7-triazabicyclo [4.4.0] dec-5-ene.

(Iii) Bis (sillohexylsulfonyl) diazomethane, 2-methyl-2-[(4-methylphenyl) sulfonyl] as a latent pH adjuster (photoacid generator) that generates an acid upon irradiation with energy radiation -1- [4- (methylthio) phenyl] -1-propanone, bis (tert-butylsulfonyl) diazomethane, bis (4-methylphenylsulfonyl) diazomethane, diphenyl-4-methylphenylsulfonium trifluoromethanesulfonate, diphenyl-2, 4,6-trimethylphenylsulfonium p-toluenesulfonate, diphenyl (4-methoxyphenyl) sulfonium trifluoromethanesulfonate, 4-methylphenyldiphenylsulfonium nonafluorobutanesulfonate, tris (4-methylphen B) sulfonium nonafluorobutanesulfonate, (1R, 2S, 5R) -5-methyl-2- (propan-2-yl) cyclohexyl 4-methoxybenzenesulfonate, bis (4-tert-butylphenyl) iodonium hexafluorophosphate, Bis (4-fluorophenyl) iodonium trifluoromethanesulfonate, cyclopropyldiphenylsulfonium tetrafluoroborate, diphenyliodonium hexafluoroarsenate, diphenyliodonium trifluoromethanesulfonic acid, 2- (3,4-dimethoxystyryl) -4,6- Bis (trichloromethyl) -1,3,5-triazine, 2- [2- (furan-2-yl) vinyl] -4,6-bis (trichloromethyl) -1,3,5-triazine, 4-a Propyl-4'-methyldiphenyliodonium tetrakis (pentafluorophenyl) borate, 2- [2- (5-methylfuran-2-yl) vinyl] -4,6-bis (trichloromethyl) -1,3,5- Triazine, 2- (4-methoxyphenyl) -4,6-bis (trichloromethyl) -1,3,5-triazine, 4-nitrobenzenediazonium tetrafluoroborate, (4-nitrophenyl) (phenyl) iodonium trifluoromethane Examples include sulfonate, triphenylsulfonium tetrafluoroborate, triphenylsulfonium bromide, tri-p-tolylsulfonium hexafluorophosphate, and tri-p-tolylsulfonium trifluoromethanesulfonate.
Moreover, you may use a commercial item. For example, "San-Aid SI-60L, SI-100L, SI-150L" manufactured by Sanshin Chemical Co., Ltd., "BBI-109", "TPS", "DBPI" manufactured by Midori Chemical Co., "UVI-6990" manufactured by Dow Chemical Company, "Irgacure 261" manufactured by Ciba Geigy and the like can be mentioned.

(Iv) Examples of latent pH adjusters (photobase generators) that generate bases upon irradiation with energy radiation include (Z)-{[bis (dimethylamino) methylidene] amino} -N-cyclohexyl (cyclohexylamino) methane Iminium tetrakis (3-fluorophenyl) borate, 1,2-dicyclohexyl-4,4,5,5-tetramethylbiguadinium n-butylloriliphenyl borate, 1,2-diisopropyl-3- [bis (dimethylamino ) Methylene] guadinium 2- (3-benzoylphenyl) propionate, 9-anthrylmethyl N, N-diethylcarbamate, (E) -1-piperidino-3- (2-hydroxyphenyl) -2-propen-1-one , 1- (anthraquinon-2-yl) ethylimidazole carboxylate 2-nitrophenylmethyl 4-methacryloyloxypiperidine-1-carboxylate, acetophenone O-benzoyloxime, 1,2-bis (4-methoxyphenyl) -2-oxoethyl cyclohexylcarbamate, 1,4-dihydro-2,6 -Dimethyl-4- (2-nitrophenyl) -3,5-pyridinedicarboxylate, 2-nitrobenzyl cyclohexylcarbamate, 2- (9-oxoxanthen-2-yl) propionic acid, 1,5,7- Triazabicyclo [4.4.0] dec-5-ene, 1,5,7-triazabicyclo [4.4.0] dec-5- (2- (9-oxoxanthen-2-yl) propionate) And the like.

The timing of adding the latent pH adjuster is not particularly limited as long as the latent pH adjuster is present at least in the cavity defined by the outer shell during gelation. For example, the latent pH adjuster can be made to exist in the cavity by dissolving the latent pH adjuster in a mixture containing the silica precursor and the monomer during suspension polymerization. When a latent pH adjuster is used, the gelation temperature can be 35 to 180 ° C., and the gelation time can be 0.1 to 48 hours.

(3) Other Steps The composite particles after the gelation step can be taken out of the emulsion by subjecting them to centrifugation, washing with water and drying as necessary.

The method for producing the organic-inorganic composite particles according to the second embodiment of the present invention comprises a radical-polymerizable monofunctional monomer and a crosslinkable monomer, a silicon alkoxide as a silica precursor, and an inorganic thickener. A mixture containing the radical polymerization initiator and in the absence of an organic solvent, in an aqueous medium by suspension polymerization to form an outer shell composed of a crosslinked polymer, and And a "porous structure forming step" of forming a porous structure in which silica particles are connected to each other inside the shell from the silicon alkoxide after or simultaneously with the formation of the shell.

(1) Shell Formation Step The mixture contains a radically polymerizable monofunctional monomer and a crosslinkable monomer, a silicon alkoxide as a silica precursor, and an inorganic thickener.
The radical polymerizable monofunctional monomer is, for example, a monomer having one vinyl group, and the radical polymerizable crosslinkable monomer is, for example, a monomer having two or more vinyl groups. .
Examples of the radically polymerizable monofunctional monomer include alkyl (meth) acrylates having 1 to 16 carbon atoms such as methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, and cetyl (meth) acrylate. ; (Meth) acrylonitrile, dimethyl maleate, dimethyl fumarate, diethyl fumarate, ethyl fumarate, maleic anhydride, N-vinylcarbazole; styrene, α-methylstyrene, paramethylstyrene, vinyltoluene, chlorostyrene, ethylstyrene And styrene-based monomers such as i-propylstyrene, dimethylstyrene, and bromostyrene. These monofunctional monomers can be used alone or in combination of two or more.

Examples of the radical polymerizable crosslinkable monomer include polyfunctional acrylic esters such as ethylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, and glycerin tri (meth) acrylate, and N, N′-methylenebis ( Examples thereof include polyfunctional acrylamide derivatives such as (meth) acrylamide and N, N'-ethylenebis (meth) acrylamide; polyfunctional allyl derivatives such as diallylamine and tetraallyloxyethane; and aromatic divinyl compounds such as divinylbenzene. These crosslinkable monomers can be used alone or in combination.
The crosslinkable monomer is preferably contained in the mixture at a ratio of 20 to 150 parts by weight based on 100 parts by weight of the monofunctional monomer. When the content of the crosslinking monomer is less than 20 parts by weight, an outer shell having sufficient strength may not be formed. When the content is more than 150 parts by weight, an outer shell may not be formed. The content is more preferably 80 to 120 parts by weight.

Examples of the silicon alkoxide as the silica precursor include a silicon alkoxide having one or more silicon atoms and an alkoxy group (for example, having 1 to 4 carbon atoms) in the same molecule. Specific examples include tetraethoxysilane (TEOS), tetramethoxysilane, tetrapropoxysilane, and the like. In addition, methyl silicate oligomer (MKC silicate, trade name, manufactured by Mitsubishi Chemical Corporation) which is a partially hydrolyzed oligomer of tetramethoxysilane, and ethyl silicate oligomer (product name, silicate 45, manufactured by Tama Chemical Co., Ltd.) which is a partially hydrolyzed oligomer of tetraethoxysilane (Pentamer), silicate 48 (10-mer)), and oligomers such as siloxane oligomers. These silica precursors can be used alone or in combination of two or more. Among them, tetraethoxysilane is preferable as a monofunctional silica precursor, and ethylsilicate oligomer is preferable as a silica precursor which is an oligomer.
The silica precursor is preferably contained in the mixture at a ratio of 60 to 400 parts by weight based on 100 parts by weight of the monofunctional monomer. When the content of the silica precursor is less than 60 parts by weight, particles having sufficient optical performance may not be obtained. When the content is more than 400 parts by weight, the components of the outer shell are relatively reduced, so that particles having sufficient strength may not be obtained. The content is more preferably 70 to 270 parts by weight, further preferably 80 to 250 parts by weight.

The inorganic thickener is not particularly limited as long as composite particles can be produced in the absence of an organic solvent. For example, an inorganic thickener capable of adjusting the viscosity of the mixture to 0.90 mPa · s or more at 25 ° C. can be suitably used. By using a mixture having this viscosity range, the movement of the silica precursor in the microcapsule partitioned by the outer shell can be suppressed, and as a result, the porosity in the microcapsule can be promoted. If the viscosity is less than 0.90 mPa · s, the effect of suppressing this becomes insufficient, and it may not be possible to obtain particles having a porous inside microcapsule. The viscosity is more preferably in the range of 0.9 to 1000 mPa · s.
Examples of the inorganic thickener include silicic anhydride and clay minerals. Examples of the clay mineral include natural clays such as bentonite, montmorillonite, saponite, beidellite, hectorite, stevensite, sauconite, nontronite, etc., vermiculite, halloysite, swelling mica, zeolite, attapulgite and other natural clays, or synthetic clays. Can be Since these have the effect of increasing the viscosity of the silicon alkoxide in the microcapsules, they can suppress the movement of the silica precursor and promote the porosity in the microcapsules. Of these, silicic anhydride is preferred because of easy dispersion in silicon alkoxide, and hydrophobic silica particles are more preferred. Here, the hydrophobicity means that the surface treatment has been performed with a hydrophobicizing agent such as an organic silane or silicone oil.

As the hydrophobizing agent, for example, hexamethyldisilazane, vinyltriethoxysilane, vinyltrimethoxysilane, trimethylsilane, trimethylchlorosilane, trimethylethoxysilane, dimethyldichlorosilane, methyltrichlorosilane, allyldimethylchlorosilane, allylphenyldichlorosilane, Benzyldimethylchlorosilane, bromomethyldimethylchlorosilane, α-chloroethyltrichlorosilane, β-chloroethyltrichlorosilane, chloromethyldimethylchlorosilane, triorganosilylmercaptan, trimethylsilylmercaptan, triorganosilyl acrylate, vinylmethylacetoxysilane, dimethylethoxysilane, Dimethyldimethoxysilane, diphenyldiethoxysilane, hexamethyldisiloxane 1,3-divinyltetramethyldisiloxane, 1,3-diphenyltetramethyldisiloxane, dimethylpolysiloxane, methyltrimethoxysilane, phenyltrimethoxysilane, methyltriethoxysilane, phenyltriethoxysilane, n-propyltrimethoxy Silane, n-propyltriethoxysilane, hexyltrimethoxysilane, hexyltriethoxysilane, octyltriethoxysilane, decyltrimethoxysilane, hexadecyltriethoxysilane, hexadecyltrimethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropyltriethoxysilane, 1,6-bis ( Methoxysilyl) hexane, trifluoropropyltrimethoxysilane, hydrolyzable group-containing siloxane, organosilanedimethylsilicone oil such as octamethylcyclotetrasiloxane, alkyl-modified silicone oil (alkyl is, for example, having 1 to 3 carbon atoms), γ- Examples thereof include silicone oils such as methylstyrene-modified silicone oil, chlorophenyl silicone oil, fluorine-modified silicone oil, and methyl hydrogen silicone oil.

The surface treatment with the hydrophobizing agent is not particularly limited, and any known method can be used. For example, there is a method of immersing a silica component in a liquid in which a hydrophobizing agent is dispersed or dissolved in a medium to remove the medium, and a method of spraying the liquid onto the silica component to remove the medium.
In addition, the hydrophobic silica particles preferably have a specific surface area of 15 m ² / g or more by a BET method. When the specific surface area is less than 15 m ² / g, the effect of thickening the silicon alkoxide in the microcapsules becomes insufficient, and a porous silica structure may not be formed in the capsules. The specific surface area is more preferably from 15 to 330 m ² / g, even more preferably from 90 to 290 m ² / g. The specific surface area by the BET method is measured, for example, according to DIN 66131.

Examples of the hydrophobic silica particles include hydrophobic fumed silica AEROSIL (trade name) series commercially available from EVONIK (eg, R972, R974, R104, R106, R202, R208, R805, R812, R812S, R816, R7200, R8200, R9200, R711, RY50, NY50, NY50L, RX50, NAX50, RX200, RX300, R504, NX90S, NX90G, RY300, REA90, REA200, RY51, NA50Y, RA200HS, NA50H, NA130K, NA200Y, NX130R RY200L, R709, R976S, etc.), hydrophobic grades of highly dispersed silica WACKER HDK (trade name) commercially available from Asahi Kasei Corporation (for example, H15, H18, H20, H30, etc.). These hydrophobic silica particles can be used alone or in combination of two or more.
The hydrophobic silica particles are preferably contained in the mixture at a ratio of 0.5 to 100 parts by weight with respect to 100 parts by weight of the mixture. When the content of the hydrophobic silica particles is less than 0.5 part by weight, the effect of increasing the viscosity of the silicon alkoxide in the microcapsules becomes insufficient, and a silica porous structure may not be formed in the capsules. When the content is more than 100 parts by weight, formation of microcapsules may be insufficient. The content is more preferably 0.5 to 25 parts by weight, even more preferably 2.5 to 15 parts by weight.
In addition, it is assumed that the hydrophobic silica particles are mixed with silica particles derived from silicon alkoxide.

In the outer shell forming step, first, a mixture containing a silica precursor, a monomer, and an inorganic thickener is dispersed in an aqueous medium by emulsification. The amount of the monomer used and the content of the component derived from the monomer constituting the outer shell substantially match.
The emulsification and dispersion are not particularly limited, and are performed while appropriately adjusting various conditions such as a stirring speed and a stirring time so as to obtain composite particles having a desired particle size.

The polymerization of the monomer is carried out in the presence of a radical polymerization initiator and in the absence of an organic solvent. The organic solvent here is, for example, pentane, hexane, cyclohexane, heptane, decane, hexadecane, toluene, xylene, ethyl acetate, butyl acetate, methyl ethyl ketone, methyl isobutyl ketone, methyl chloride, methylene chloride, chloroform, carbon tetrachloride, etc. It is a hydrophobic organic solvent (hydrophobic here means that the solubility in water at 25 ° C. is less than 10 g / 100 g (water)). In addition, this organic solvent does not include a water-soluble organic solvent of a lower alcohol (for example, methanol, ethanol, or the like) (the water solubility here indicates that the solubility in water at 25 ° C. is 10 g / 100 g (water) or more). That is).

The radical polymerization initiator and the aqueous medium can be used in the same types and amounts as in the production method of the first embodiment.

Furthermore, by performing polymerization in the presence of an alkoxide compound of titanium, zirconium or aluminum, which has a higher hydrolyzability than silicon alkoxide, a silica porous structure can be easily formed in the capsule. These compounds are more hydrolyzable than silica precursors such as silicon alkoxides, so they gel in microcapsules, suppress the movement of silica precursors in capsules, and have the effect of promoting porosity. The present inventors believe that there is.

An alkoxide compound such as an alkoxide compound of titanium, an alkoxide compound of zirconium, and an alkoxide compound of aluminum can be used in the same kind and amount as in the production method of the first embodiment.

(2) Porous Structure Forming Step The porous structure forming step is performed substantially in the same manner as the “(2) gelling step” in the manufacturing method of the first embodiment, and therefore the description is omitted here. .

(3) Other Steps The composite particles after the porous structure forming step can be taken out of the emulsion by, if necessary, undergoing centrifugation, washing and drying.

(Application)
The composite particles can be used for applications such as cosmetics, coating compositions, heat-insulating resin compositions, light-diffusing resin compositions, and light-diffusing films.
(1) Cosmetic The cosmetic preferably contains the composite particles in a range of 1 to 40% by weight.
Cosmetics include soaps, body shampoos, facial cleansers, facial cleansers, scrubs, etc. Cosmetics for hair washing, hair coloring, hair styling, aromatic cosmetics, toothpaste, bath preparation, antiperspirant, sunscreen products, suntan products, body cosmetics such as body powder, baby powder, shaving cream, pre-shaving lotion, Lotions such as aftershave lotion and body lotion.

In addition, components generally used in cosmetics can be blended according to the purpose within a range that does not impair the effects of the present invention. As such components, for example, water, lower alcohols, fats and waxes, hydrocarbons, higher fatty acids, higher alcohols, sterols, fatty acid esters, metal soaps, humectants, surfactants, polymer compounds, coloring material raw materials, Perfumes, preservatives / bactericides, antioxidants, ultraviolet absorbers, and special compounding ingredients.
Oils and waxes include avocado oil, almond oil, olive oil, cocoa butter, beef tallow, sesame oil, wheat germ oil, safflower oil, shea butter, turtle oil, camellia oil, persic oil, castor oil, grape oil, macadamia nut oil, mink Examples include oil, egg yolk oil, mokuro, coconut oil, rosehip oil, hardened oil, silicone oil, orange roughy oil, carnauba wax, candelilla wax, whale wax, jojoba oil, montan wax, beeswax, lanolin and the like.
Examples of the hydrocarbon include liquid paraffin, vaseline, paraffin, ceresin, microcrystalline wax, squalane, and the like. Higher fatty acids include lauric acid, myristic acid, palmitic acid, stearic acid, oleic acid, behenic acid, undecylenic acid, oxystearic acid, linoleic acid, lanolin fatty acid, and synthetic fatty acids.

As higher alcohols, lauryl alcohol, cetyl alcohol, cetostearyl alcohol, stearyl alcohol, oleyl alcohol, behenyl alcohol, lanolin alcohol, hydrogenated lanolin alcohol, hexyldecanol, octyldecanol, isostearyl alcohol, jojoba alcohol, decyltetradecanol, etc. No.
Sterols include cholesterol, dihydrocholesterol, phytocholesterol and the like.
Fatty acid esters include ethyl linoleate, isopropyl myristate, isopropyl lanolin fatty acid, hexyl laurate, myristyl myristate, cetyl myristate, octyl dodecyl myristate, decyl oleate, octyl dodecyl oleate, hexadecyl dimethyl octanoate, isooctanoic acid Cetyl, decyl palmitate, glyceryl trimmyristate, glycerin tri (caprylate / caprate), propylene glycol dioleate, glycerin triisostearate, glycerin triisooctanoate, cetyl lactate, myristyl lactate, diisostearyl malate or cholesteryl isostearate And cyclic alcohol fatty acid esters such as cholesteryl 12-hydroxystearate.

Examples of the metal soap include zinc laurate, zinc myristate, magnesium myristate, zinc palmitate, zinc stearate, aluminum stearate, calcium stearate, magnesium stearate, and zinc undecylenate.
Examples of the humectant include glycerin, propylene glycol, 1,3-butylene glycol, polyethylene glycol, sodium dl-pyrrolidonecarboxylate, sodium lactate, sorbitol, sodium hyaluronate, polyglycerin, xylitol, maltitol and the like.
Examples of the surfactant include anionic surfactants such as higher fatty acid soaps, higher alcohol sulfates, N-acyl glutamates and phosphates, cationic surfactants such as amine salts and quaternary ammonium salts, and betaine. Surfactants such as amino acid type, amino acid type, imidazoline type and lecithin, and nonionic surfactants such as fatty acid monoglyceride, propylene glycol fatty acid ester, sorbitan fatty acid ester, sucrose fatty acid ester, polyglycerin fatty acid ester, and ethylene oxide condensate. No.

As the high molecular compound, gum arabic, tragacanth gum, guar gum, locust bean gum, karaya gum, iris moss, quince seed, gelatin, shellac, rosin, casein and other natural high molecular compounds, sodium carboxymethyl cellulose, hydroxyethyl cellulose, methyl cellulose, ethyl cellulose, Semi-synthetic polymer compounds such as sodium alginate, ester gum, nitrocellulose, hydroxypropylcellulose, crystalline cellulose, polyvinyl alcohol, polyvinylpyrrolidone, sodium polyacrylate, carboxyvinyl polymer, polyvinyl methyl ether, polyamide resin, silicone oil, nylon particles , Polymethyl methacrylate particles, cross-linked polystyrene particles, silicon particles, urethane particles, polyethylene Child, synthetic polymer compounds such as resin particles of the silica particles and the like.

Color material raw materials include iron oxide, ultramarine, konjo, chromium oxide, chromium hydroxide, carbon black, manganese violet, titanium oxide, zinc oxide, talc, kaolin, mica, calcium carbonate, magnesium carbonate, mica, aluminum silicate, Inorganic pigments such as barium silicate, calcium silicate, magnesium silicate, silica, zeolite, barium sulfate, calcined calcium sulfate (baked gypsum), calcium phosphate, hydroxyapatite, ceramic powder, etc., azo type, nitro type, nitroso type, xanthene type And quinoline, anthraquinoline, indigo, triphenylmethane, phthalocyanine and pyrene tar dyes.

Here, the powder material such as the polymer compound or the coloring material may be subjected to a surface treatment in advance. As the surface treatment method, a conventionally known surface treatment technique can be used. For example, oil treatment with hydrocarbon oil, ester oil, lanolin, etc., silicone treatment with dimethylpolysiloxane, methylhydrogenpolysiloxane, methylphenylpolysiloxane, etc., perfluoroalkyl group-containing ester, perfluoroalkylsilane, perfluoropolyether , A fluorine compound treatment with a polymer having a perfluoroalkyl group, a silane coupling agent treatment with 3-methacryloxypropyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, etc., isopropyl triisostearoyl titanate, isopropyl tris ( Titanium coupling agent treatment with dioctyl pyrophosphate) titanate, etc., metal soap treatment, amino acid treatment with acylglutamic acid, etc., lecithin with hydrogenated egg yolk lecithin, etc. Treatment, collagen treatment, polyethylene process, moisture retention treatment, an inorganic compound treatment, and processing methods such as mechanochemical treatment.

Examples of the flavor include natural flavors such as lavender oil, peppermint oil, and lime oil, and synthetic flavors such as ethylphenyl acetate, geraniol, and p-tert-butylcyclohexyl acetate. Examples of the preservative / bactericide include methyl paraben, ethyl paraben, propyl paraben, benzalkonium, benzethonium and the like.
Examples of the antioxidant include dibutylhydroxytoluene, butylhydroxyanisole, propyl gallate, and tocopherol. Examples of the ultraviolet absorber include inorganic absorbers such as titanium oxide, zinc oxide, cerium oxide, iron oxide, and zirconium oxide, benzoic acid, p-aminobenzoic acid, anthranilic acid, salicylic acid, and cinnamic acid. Organic absorbents such as benzophenone and dibenzoylmethane are exemplified.

Special compounding ingredients 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, aluminum chloride, sulfuric acid Skin astringents such as aluminum / potassium, allantoinchlorohydroxyaluminum, zinc paraphenolsulfonate, zinc sulfate, etc. Hair growth promoters such as E, estrogen, and photosensitizer; and whitening agents such as magnesium phosphate-L-ascorbate and kojic acid.

(2) Paint, heat-insulating property, and light-diffusing composition These compositions contain a binder resin, a UV-curable resin, a solvent, and the like, if necessary. As the binder resin, a resin soluble in an organic solvent or water or an emulsion-type aqueous resin dispersible in water can be used.
The addition amount of the binder resin or the UV curable resin and the composite particles also varies depending on the thickness of the formed coating film, the average particle size of the composite particles, and the coating method. The added amount of the composite particles is preferably 5 to 50% by weight based on the total amount of the binder resin (solid content when an emulsion type aqueous resin is used) and the composite particles. A more preferred content is 10 to 50% by weight, and a still more preferred content is 20 to 40% by weight.
Examples of the binder resin include an acrylic resin, an alkyd resin, a polyester resin, a polyurethane resin, a chlorinated polyolefin resin, an amorphous polyolefin resin, an acrylic silicone resin, an acrylic urethane resin, and a fluorine-based resin. Polyfunctional (meth) acrylate resins such as alcohol polyfunctional (meth) acrylates; and polyfunctional urethane acrylate resins synthesized from diisocyanates, polyhydric alcohols, and hydroxy-containing (meth) acrylates, and the like. No.

As the UV-curable resin, a polyfunctional (meth) acrylate resin is preferable, and a polyhydric alcohol polyfunctional (meth) acrylate resin having three or more (meth) acryloyl groups in one molecule is more preferable. As the polyhydric alcohol polyfunctional (meth) acrylate resin having three or more (meth) acryloyl groups in one molecule, specifically, trimethylolpropane tri (meth) acrylate, trimethylolethanetri (meth) acrylate 1,2,4-cyclohexanetetra (meth) acrylate, pentaglycerol triacrylate, pentaerythritol tetra (meth) acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol triacrylate, dipentaerythritol pentaacrylate, dipentaerythritol Examples include tetra (meth) acrylate, dipentaerythritol hexa (meth) acrylate, tripentaerythritol triacrylate, and tripentaerythritol hexaacrylate. It is, or may be even alone, or two or more are used alone.

When using a UV curable resin, a photopolymerization initiator is usually used in combination. The photopolymerization initiator is not particularly limited.
Examples of the photopolymerization initiator include acetophenones, benzoins, benzophenones, phosphine oxides, ketals, α-hydroxyalkylphenones, α-aminoalkylphenones, anthraquinones, thioxanthones, azo compounds, and peroxides. (See Japanese Patent Application Laid-Open No. 2001-139666), 2,3-dialkyldione compounds, disulfide compounds, fluoroamine compounds, aromatic sulfoniums, onium salts, borate salts, active halogen compounds, α -Acyl oxime esters and the like.
These binder resins or UV-curable resins can be appropriately selected depending on the adhesion of the paint to the substrate to be coated, the environment in which the paint is used, and the like.

The solvent is not particularly limited, but it is preferable to use a solvent that can dissolve or disperse the binder resin or the UV-curable resin. For example, in the case of oil-based paints, 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; dioxane, ethylene glycol diethyl ether, and ethylene glycol Examples include ether solvents such as monobutyl ether. If it is a water-based paint, water, alcohols and the like can be used. These solvents may be used alone or as a mixture of two or more. The content of the solvent in the coating material is usually about 20 to 60% by weight based on the total amount of the composition.

The composition contains, if necessary, a known coating surface adjuster, a fluidity adjuster, an ultraviolet absorber, a light stabilizer, a curing catalyst, an extender pigment, a color pigment, a metal pigment, a mica powder pigment, a dye, and the like. It may be.
The method for forming a coating film using the composition is not particularly limited, and any known method can be used. For example, methods such as spray coating, roll coating, brush coating, and coating a substrate such as a film as a thin layer by coating reverse roll coating, gravure coating, die coating, comma coating, spray coating, etc. Is mentioned. The composition may be diluted if necessary to adjust the viscosity. Examples of the diluent include hydrocarbon solvents such as toluene and xylene; ketone solvents such as methyl ethyl ketone and methyl isobutyl ketone; ester solvents such as ethyl acetate and butyl acetate; ether solvents such as dioxane and ethylene glycol diethyl ether; An alcohol-based solvent and the like. These diluents may be used alone or in combination of two or more.
A coating film can be formed by applying a coating film on an arbitrary coating surface such as a base material to prepare a coating film, drying the coating film, and curing the coating film as needed. The coating film using the coating composition is used after being coated on various substrates, and is not particularly limited to metal, wood, glass, plastics and the like. Further, a transparent base material such as polyethylene terephthalate (PET), polycarbonate (PC), and acryl can be coated and used.

(3) Light-diffusing film The light-diffusing film is a base material such as glass, polycarbonate (PC), acrylic resin, polyethylene terephthalate (PET), triacetyl cellulose (TAC), and other plastic sheets, plastic films, plastic lenses, and plastic panels. And a light diffusion layer of the light diffusing composition formed on the surface of a base material such as a cathode ray tube, a fluorescent display tube, a liquid crystal display panel and the like. Depending on the application, the coating may be used alone or on a substrate, such as a protective film, a hard coat film, a flattening film, a high refractive index film, an insulating film, a conductive resin film, a conductive metal particle film, or a conductive metal oxide particle. It is formed in combination with a film and other primer films used as necessary. When used in combination, the light diffusion layer does not necessarily need to be formed on the outermost surface.

Hereinafter, the present invention will be described specifically with reference to Examples, but the present invention is not limited thereto. First, the measuring method in the examples will be described.

(Measurement of volume average particle size)
The volume average particle diameter of the composite particles was measured using Coulter Multisizer ^™ 3 (a measuring device manufactured by Beckman Coulter, Inc.). The measurement was performed using an aperture calibrated according to the Multisizer ^™ 3 User's Manual issued by Beckman Coulter.
The aperture used for the measurement is selected as follows. When the assumed volume average particle diameter of the particles to be measured is 1 μm or more and 10 μm or less, an aperture having a size of 50 μm is selected, and the assumed volume average particle diameter of the particles to be measured is 10 μm. If the size is larger than 30 μm or less, an aperture having a size of 100 μm is selected. When the particle diameter was larger than 90 μm and 150 μm or less, an aperture having a size of 400 μm was appropriately selected. When the volume average particle size after the measurement was different from the assumed volume average particle size, the aperture was changed to an aperture having an appropriate size, and the measurement was performed again.

When an aperture having a size of 50 μm is selected, Current (aperture current) is set to −800 and Gain is set to 4. When an aperture having a size of 100 μm is selected, Current (aperture current) is set to −. 1600, Gain (gain) was set to 2, and when apertures having sizes of 280 μm and 400 μm were selected, Current (aperture current) was set to −3200, and Gain (gain) was set to 1.
As a measurement sample, 0.1 g of the polymer particles was put in 10 ml of a 0.1% by weight aqueous nonionic surfactant solution, and a touch mixer ("TOUCHMIXER MT-31" manufactured by Yamato Scientific Co., Ltd.) and an ultrasonic cleaner (Vervok) were used. Dispersion was performed using "ULTRASONICCLEANER VS-150" manufactured by Leer Co., Ltd. to obtain a dispersion. During the measurement, the inside of the beaker was gently stirred so as not to cause bubbles, and the measurement was terminated when 100,000 particles were measured. The volume average particle diameter of the particles was an arithmetic mean in a volume-based particle size distribution of 100,000 particles.

(Measurement of amount of inorganic component in composite particles)
After weighing 1.0 g of the composite particles to be measured, the weighed composite particles were burned out at 750 ° C. for 30 minutes in an electric furnace, and the weight (g) of the remaining residue was measured. Then, the measured weight (g) of the residue was 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.

(Weight of porous structure in composite particles)
After weighing 1.0 g of the composite particles to be measured, the weighed composite particles were burned out at 750 ° C. for 30 minutes in an electric furnace, and the weight (g) of the remaining residue was measured. Then, the measured weight (g) of the residue was 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. The obtained ignition residue (% by weight) represented the content of the porous structure in the composite particles.

(Measurement of carbon atom weight in internal porous structure)
The composite particles were mixed with a photocurable resin D-800 (manufactured by JEOL Ltd.) and irradiated with light to obtain a cured product. Thereafter, the cured product was immersed in liquid nitrogen for 5 minutes, then cut, and affixed to a sample table with a carbon tape with the cross section facing upward. Platinum vapor deposition (15 mV, 240 seconds, 6.0 Pa, distance between target and sample surface: 30 mm) was performed using a Hitachi High-Technologies “Ion Sputter E-1045” sputtering apparatus. Next, the cross section of the particles in the sample was photographed using a secondary electron detector of a “Regulus 8230” scanning electron microscope manufactured by Hitachi High-Technologies Corporation (magnification of the photograph of the particle cross section: 5,000 times). The accelerating voltage during observation was 10 kV.
In the particle cross-section observation, elemental analysis was performed using "X-MaxN150" manufactured by Oxford Instruments Inc. provided for "Regulus 8230" manufactured by Hitachi High-Technologies Corporation. The internal porous portion in the particle cross section was arbitrarily set as an analysis region, and the atomic number concentration (%) of carbon atoms and the atomic number concentration (%) of silicon atoms in the analysis region were measured. The atomic concentration of carbon atoms (%) and the atomic concentration of silicon atoms (%) exclude the carbon atoms and silicon atoms from the observed atoms. The values were re-analyzed using software attached to “X-MaxN150” manufactured by Oxford Instruments Inc. so that the total atomic concentration (%) of atoms becomes 100%. The acceleration voltage at the time of analysis was 10 kV. The resolution in the image scan setting was 1024, the dwell time was 5 μs, and the input signal was SE. In addition, the energy range, the number of channels, and the acquisition mode in the EDS acquisition spectrum setting were set automatically, and the process time was set to 6.
FIG. 8 shows an example of an analysis region set as an internal porous portion in a photograph of a particle cross section. The inside of the white frame described as spectrum 19 in FIG. 8 was set as the analysis region. The number of carbon atoms (%) and the number of silicon atoms (%) in the white frame are the number of carbon atoms (%) and the number of silicon atoms (%) in the internal porous structure. And

(Density of mixture)
The mixed solution whose temperature was adjusted in a 25 ° C. constant temperature bath was added to a 25 mL pycnometer. The density of the mixture was determined by dividing the weight (g) of the added mixture by the volume (mL) of the pycnometer.

(Viscosity of the mixture)
The viscosity of the mixed solution whose temperature was adjusted in a 25 ° C. constant temperature bath was measured using a tuning fork vibrating viscometer SV-10 (manufactured by A & D). The viscosity (unit: mPa · s) of the mixed solution was determined by dividing the indicated viscosity value on the apparatus (unit: mPa · s × g / cm ³ ) by the calculated density of the mixed solution.

(Observation of particle surface)
The sample was cut out, a conductive tape was stuck on the sample stage, and the sample was mounted thereon. The particles were subjected to a surface treatment (10 Pa, 5 mA, 10 seconds) using an “Osmium Coater Neoc-Pro” coating device manufactured by Meiwa Forsys. Next, the surface of the particles was photographed using a secondary electron detector of a scanning electron microscope “SU1510” manufactured by Hitachi High-Technologies Corporation.

(Particle cross section observation)
After the washing step, the particles dried at 100 ° C. were mixed with a photocurable resin D-800 (manufactured by JEOL Ltd.) and irradiated with ultraviolet light to obtain a cured product. Thereafter, the cured product was cut with a nipper, the cross section was processed smoothly using a cutter, and the surface treatment (10 Pa, 5 mA, 10 mA) was performed using an osmium coating device (“Osmium coater Neoc-Pro” manufactured by Meiwa Forsys). Seconds). Next, the cross section of the sample was photographed using a secondary electron detector of a scanning electron microscope “SU1510” manufactured by Hitachi High-Technologies Corporation.
Here, the cross section of the sample was subjected to element mapping by SEM-EDS (Scanning Electron Microscope Energy Dispersive X-ray Spectrometry) to determine whether or not silica and titanium oxide exist inside the cavity. Specifically, using an SEM (“S3400N” manufactured by Hitachi High-Technologies Corporation) and an EDS (“EMAX Evolution X-Max” manufactured by HORIBA), an acceleration voltage of 15 KV and 10 frames (800 seconds) are captured, and silicon is captured. Elemental maps were obtained with Kα rays and Kα rays of titanium.

(Particle size of second inorganic particles)
The particle diameter of the second inorganic particles was an average particle diameter measured using a method called a dynamic light scattering method or a photon correlation method. That is, at 25 ° C., a dispersion of an organic solvent of inorganic particles adjusted to 0.1% by volume was irradiated with laser light, and the intensity of scattered light scattered from the inorganic particles was measured over time in microsecond units. The distribution of scattering intensity resulting from the detected inorganic particles was applied to a normal distribution, and the Z-average particle diameter was calculated by cumulant analysis. This average particle size could be easily measured with a measuring device equipped with commercially available data analysis software, and could be automatically analyzed. In the present example, the measurement was carried out using a particle size measuring apparatus “Zetasizer Nano ZS” manufactured by Malvern (Spectris).

(Surface treatment method for titanium oxide)
To a stainless steel mixing tank, 31 g of toluene and 5.0 g of a phosphoric acid-based dispersant as an organic dispersant were weighed and charged, followed by stirring with a mixer for 5 minutes. Subsequently, an additional 60 g of titanium oxide as inorganic particles was added, and the mixture was further stirred with a mixer for 30 minutes. This was designated as solution (A). The solution (A) was transferred to a bead mill container filled with zirconia beads having a particle diameter of 1.5 mm, and the inside of the mill was stirred for 60 minutes to disperse the inorganic particles. Next, in order to adjust the viscosity of the dispersion, 3.0 g of bentonite was added thereto, followed by stirring and dispersion, and a toluene solution of titanium oxide (X) (titanium oxide content: 60.6%, solid content: 68.7%) Obtained. The Z-average particle diameter of the titanium oxide was 780 nm.

(Example 1)
100 g of methyl methacrylate (MMA) as a monofunctional monomer, 100 g of ethylene glycol dimethacrylate (EGDMA) as a crosslinkable monomer, 160 g of tetraethoxysilane (TEOS) as a silica precursor, and ( 1R, 2S, 5R) -5-Methyl-2- (propan-2-yl) cyclohexyl 4-methylbenzenesulfonate (product name WPAG-699, manufactured by Wako Pure Chemical Industries, Ltd.), 1 g of toluene as a non-reactive organic solvent 39.75 g, 2,2′-azobis (2,4-dimethylvaleronitrile) as a polymerization initiator (manufactured by Wako Pure Chemical Industries, Ltd .; product name V-65), 2.0 g, oxidation as second inorganic particles 0.77 g of a toluene solution (X) of titanium particles was mixed and dissolved to prepare a mixture. The obtained mixture was mixed with 1200 g of an aqueous solution of polyvinyl alcohol (PVA) (manufactured by Nippon Synthetic Chemical Company; product name: Gohsenol GL-5) prepared at a concentration of 1.7% by weight.
The obtained mixture was put into a 2 L beaker, and emulsification / dispersion treatment was performed at a rotation speed of 5000 rpm for 6 minutes using a homogenizer (manufactured by Central Science and Trading; product name: Polytron homogenizer PT10-35GT). The obtained emulsion was put into a 2 L stainless steel autoclave, and polymerization was carried out at a temperature of 50 ° C. for 4 hours while stirring at 250 rpm with a turbine-like stirring blade having a diameter of 8 cm, thereby obtaining TEOS as a silica precursor. And a microcapsule containing titanium oxide therein. Thereafter, the mixture was stirred for 2 hours under the condition of 105 ° C., whereby a gelation reaction of TEOS in the microcapsules was progressed to obtain composite particles.
After repeated washing with water and purification, the resultant was dried in a vacuum oven at 100 ° C. overnight. FIG. 1A shows a photograph of the surface of the obtained composite particles, and FIG. 1B shows a photograph of a cross section thereof. It was confirmed that an outer shell composed of a monofunctional monomer and a crosslinkable monomer was formed, and that a porous structure in which silica particles were connected to each other was formed inside. Further, the volume average particle diameter was 10.0 μm, and the amount of the inorganic component in the composite particles was 17.9% by weight.
FIGS. 1C to 1E show metal element mapping diagrams by SEM-EDS. FIG. 1 (c) is a cross-sectional photograph, FIG. 1 (d) is a diagram showing the presence of silicon, and FIG. 1 (e) is a diagram showing the presence of titanium. These photographs confirmed the presence of silicon and titanium in the composite particles.

(Example 2)
Composite particles were obtained in the same manner as in Example 1, except that 3.85 g of a toluene solution (X) of titanium oxide particles as second inorganic particles and 38.76 g of toluene of a non-reactive organic solvent were used. . FIG. 2A shows a photograph of the surface of the obtained composite particles, and FIG. 2B shows a photograph of a cross section thereof. It was confirmed that an outer shell composed of a monofunctional monomer and a crosslinkable monomer was formed, and that a porous structure in which silica particles were connected to each other was formed inside. Further, the volume average particle diameter was 10.4 μm, and the amount of the inorganic component in the composite particles was 7.5% by weight.

(Example 3)
1.54 g of a methanol dispersion of zirconium oxide particles as second inorganic component particles (manufactured by Sakai Chemical Co .; product name SZR-M, zirconia content 30% by weight, particle diameter: 3 nm), as a non-reactive organic solvent Except that 38.9 g of toluene was used, composite particles were obtained in the same manner as in Example 1. FIG. 3A shows a photograph of the surface of the obtained composite particles, and FIG. 3B shows a photograph of a cross section thereof. It was confirmed that an outer shell composed of a monofunctional monomer and a crosslinkable monomer was formed, and that a porous structure in which silica particles were connected to each other was formed inside. The volume average particle diameter was 11.4 μm, and the amount of the inorganic component in the composite particles was 16.8% by weight.

(Example 4)
0.46 g of cerium oxide as second inorganic component particles (manufactured by I-Tech Co., Ltd .; product name: ceria nanoparticle powder, particle diameter: 10 nm); Composite particles were obtained in the same manner as in Example 1, except that 0.046 g of product name (Plenact ALM) and 40 g of toluene as a non-reactive organic solvent were used. FIG. 4A shows a surface photograph of the obtained composite particles, and FIG. 4B shows a cross-sectional photograph thereof. It was confirmed that an outer shell composed of a monofunctional monomer and a crosslinkable monomer was formed, and that a porous structure in which silica particles were connected to each other was formed inside. Further, the volume average particle diameter was 11.7 μm, and the amount of the inorganic component in the composite particles was 8.9% by weight.

(Comparative Example 1)
Composite particles were obtained in the same manner as in Example 1, except that the amount of toluene as a non-reactive organic solvent was 40 g and no titanium oxide particles were added. FIG. 5A shows a photograph of the surface of the obtained composite particles, and FIG. 5B shows a photograph of a cross section thereof. It was confirmed that the shell composed of the monofunctional monomer and the crosslinkable monomer was formed. In addition, a porous structure in which silica particles were connected to each other was confirmed. Further, the volume average particle diameter was 11.9 μm, and the amount of the inorganic component in the composite particles was 16.0% by weight.

(Comparative Example 2)
Silica-containing particles (composite particles) were prepared with reference to Non-Patent Document 1. Specifically, 100 g of methyl methacrylate (MMA) as a monofunctional monomer, 100 g of ethylene glycol dimethacrylate (EGDMA) as a crosslinkable monomer, 200 g of tetraethoxysilane (TEOS) as a silica precursor, A polymerizable composition was prepared by mixing 2 g of 2,2′-azobis (4-methoxy-2,4-dimethylvaleronitrile) (Wako Pure Chemical Industries, Ltd .; product name V-70) as an agent.
On the other hand, 20 g of polyvinyl alcohol (PVA) (manufactured by Nippon Gohsei; Gohsenol GL-05) was added to 1180 g of ion-exchanged water as an aqueous phase. The polymerizable composition was put into the aqueous phase, and emulsification / dispersion treatment was performed at a rotation speed of 5000 rpm for 10 minutes using a homogenizer (manufactured by Central Kagaku Trading Co., Ltd .; product name: Polytron homogenizer PT10-35GT). The obtained emulsion is charged into a 2 L pressure vessel with stirring blades, and the mixture is heated at 30 ° C. for 24 hours while stirring the stirring blades at 350 rpm, thereby comprising a monofunctional monomer and a crosslinkable monomer. An outer shell was formed. While maintaining the reaction temperature and stirring, 10 times equivalent of aqueous ammonia was added to TEOS, and the mixture was heated for 24 hours to allow the sol-gel reaction of TEOS to proceed to obtain an emulsion containing silica-containing particles.
By performing suction filtration on the obtained emulsion, silica-containing particles were taken out from the emulsion. After repeated washing with water and purification, the silica-containing particles were obtained by drying in a vacuum oven at 60 ° C. FIG. 6A shows a surface photograph of the obtained silica-containing particles, and FIG. 6B shows a cross-sectional photograph thereof. It was confirmed that an outer shell composed of a monofunctional monomer and a crosslinkable monomer was formed, and that one or more silica particles were included therein. The volume average particle diameter was 10.4 μm, and the amount of the inorganic component in the silica-containing particles was 22.0% by weight.

The raw materials for producing the silica-containing particles of Examples 1 to 4 and Comparative Examples 1 to 2 and the amounts (parts by weight) of the raw materials used are collectively shown in Table 1.

(Evaluation of reflection characteristics of ultraviolet, visible, and near-infrared light)
2.5 g each of the composite particles obtained from Examples 1-4 and Comparative Examples 1-2 were added to 10 g of a commercially available water-based paint (trade name, manufactured by Asahipen Co., Ltd .; water-based multi-purpose color clear), and a planetary stirring defoamer was added. (Murastar KK-250, manufactured by KURABO) was defoamed and stirred to prepare a paint for evaluation.
The paint for evaluation was applied to the black side of the opacity test paper using an applicator set to a wet thickness of 250 μm, and then sufficiently dried at room temperature to obtain a sample plate for light reflectivity evaluation. The reflectance of the sample plate to ultraviolet light, visible light, and near-infrared light was evaluated in the following order.
An ultraviolet-visible-near-infrared spectrophotometer (Solid Spec 3700) manufactured by Shimadzu Corporation was used as a reflectivity measuring device to measure the reflection characteristics from ultraviolet light to near-infrared light (wavelength 300 to 2500 nm) on the coated surface of the sample plate. It was measured as reflectivity (%). The measurement was carried out using a 60 mmΦ integrating sphere and using Spectralon as a standard white plate.
The above measurements were performed on the composite particles of Examples 1 to 4 and Comparative Examples 1 and 2. FIG. 7 shows the obtained results.
FIG. 7 shows that the composite particles of Examples 1 to 4 have higher reflectance than the composite particles of Comparative Examples 1 and 2 at almost all wavelengths from ultraviolet light to near-infrared light. In particular, it can be seen that it has a high reflectance in the wavelength range of 500 to 2500.

(Example 5)
80 g of methyl methacrylate (MMA) as a monofunctional monomer, 80 g of ethylene glycol dimethacrylate (EGDMA) as a crosslinkable monomer, 160 g of tetraethoxysilane (TEOS) as a silica precursor, and hydrophobicity as hydrophobic silica particles Fumed silica R972 (EVONIK, BET specific surface area 110 ± 20 m ² / g) 16 g, 1.6 g of 2,2′-azobis (2,4-dimethylvaleronitrile) as a polymerization initiator (Wako Pure Chemical Industries, Ltd.) (Product name V-65), (1R, 2S, 5R) -5-methyl-2- (propan-2-yl) cyclohexyl 4-methylbenzenesulfonate (manufactured by Wako Pure Chemical Industries, Ltd.) as a thermal acid generator A product consisting of 0.8 g of product name WPAG-699) was prepared. The viscosity of the mixture was 3.58 mPa · s.
On the other hand, 26 g of magnesium pyrophosphate and 0.128 g of lauryl phosphoric acid were added to 1280 g of ion-exchanged water as a suspension stabilizer to prepare an aqueous phase. The mixture was put into the aqueous phase, and emulsification / dispersion treatment was performed at 7000 rpm for 10 minutes using a homogenizer (manufactured by Central Kagaku Trading Co., Ltd .; product name: Polytron homogenizer PT10-35). The obtained emulsion is put into a 2 L pressure vessel with a stirring blade, and the stirring blade is heated at 50 ° C. for 4 hours while being stirred at 350 rpm, thereby comprising a monofunctional monomer and a crosslinkable monomer. An outer shell was formed. While maintaining the stirring, the reaction temperature was raised to 105 ° C., and the mixture was heated for 2 hours to allow the gelation reaction of TEOS to proceed. Thereafter, the reaction system was cooled to room temperature to obtain an emulsion containing the composite particles. Hydrochloric acid was added to the obtained emulsion to dissolve magnesium pyrophosphate, and then suction filtration was performed to take out composite particles from the emulsion. After repeated washing with water and purification, the composite particles were obtained by drying in a vacuum oven at 60 ° C.
FIG. 9A shows a surface photograph of the obtained composite particles, and FIG. 9B shows a cross-sectional photograph thereof. It was confirmed that an outer shell derived from the monofunctional monomer and the crosslinkable monomer was formed, and that a porous structure in which silica particles were connected to each other was formed inside. The volume average particle diameter was 20.7 μm, and the weight of the porous structure in the composite particles was 27.0% by weight.

(Example 6)
Composite particles were obtained in the same manner as in Example 5, except that 12 g of hydrophobic silica particles were used. The viscosity of the mixture was 2.39 mPa · s. FIG. 10A shows a surface photograph of the obtained composite particles, and FIG. 10B shows a cross-sectional photograph thereof. It was confirmed that an outer shell composed of a monofunctional monomer and a crosslinkable monomer was formed, and that a porous structure in which silica particles were connected to each other was formed inside. The volume average particle size was 9.5 μm, and the weight of the porous structure in the composite particles was 24.2% by weight. The weight of silica in the composite particles was 25.1%.
In addition, when the atomic number concentration (%) of carbon atoms in the internal porous structure was measured, it was 90.4%, and it was confirmed that the crosslinked polymer component forming the outer shell was included.

(Example 7)
Composite particles were obtained in the same manner as in Example 5, except that 8 g of hydrophobic silica particles were used. The viscosity of the mixture was 1.61 mPa · s. FIG. 11A shows a surface photograph of the obtained composite particles, and FIG. 11B shows a cross-sectional photograph thereof. It was confirmed that an outer shell composed of a monofunctional monomer and a crosslinkable monomer was formed, and that a porous structure in which silica particles were connected to each other was formed inside. The volume average particle diameter was 11.4 μm, and the weight of the porous structure in the composite particles was 23.3% by weight.

(Example 8)
Composite particles were obtained in the same manner as in Example 5, except that 1.6 g of hydrophobic silica particles were used. The viscosity of the mixture was 0.93 mPa · s. FIG. 12A shows a surface photograph of the obtained composite particles, and FIG. 12B shows a cross-sectional photograph thereof. It was confirmed that an outer shell composed of a monofunctional monomer and a crosslinkable monomer was formed, and that a porous structure in which silica particles were connected to each other was formed inside. The volume average particle diameter was 16.1 μm, and the weight of the porous structure in the composite particles was 21.6% by weight.

(Example 9)
Composite particles were obtained in the same manner as in Example 5, except that 24 g of hydrophobic silica particles were used. The viscosity of the mixture was 8.07 mPa · s. It was confirmed that an outer shell composed of a monofunctional monomer and a crosslinkable monomer was formed, and that a porous structure in which silica particles were connected to each other was formed inside. The volume average particle size was 20.3 μm, and the weight of the porous structure in the composite particles was 29.1% by weight.

(Example 10)
Composite particles were obtained in the same manner as in Example 5, except that 36 g of hydrophobic silica particles were used. The viscosity of the mixture was 46.3 mPa · s. FIG. 13A shows a surface photograph of the obtained composite particles, and FIG. 13B shows a cross-sectional photograph thereof. It was confirmed that an outer shell composed of a monofunctional monomer and a crosslinkable monomer was formed, and that a porous structure in which silica particles were connected to each other was formed inside. Further, the volume average particle diameter was 21.6 μm, and the weight of the porous structure in the composite particles was 31.8% by weight.

(Example 11)
Composite particles were obtained in the same manner as in Example 5, except that 8 g of hydrophobic fumed silica R974 (EVONIK, specific surface area by BET method: 170 ± 20 m ² / g) was used as the hydrophobic silica particles. The viscosity of the mixture was 1.76 mPa · s. FIG. 14A shows a surface photograph of the obtained composite particles, and FIG. 14B shows a cross-sectional photograph thereof. It was confirmed that an outer shell composed of a monofunctional monomer and a crosslinkable monomer was formed, and that a porous structure in which silica particles were connected to each other was formed inside. The volume average particle diameter was 11.0 μm, and the weight of the porous structure in the composite particles was 23.9% by weight.

(Example 12)
Composite particles were obtained in the same manner as in Example 5, except that 8 g of hydrophobic fumed silica R976S (EVONIK, specific surface area of 240 ± 25 m ² / g by BET method) was used as the hydrophobic silica particles. The viscosity of the mixture was 1.54 mPa · s. FIG. 15A shows a photograph of the surface of the obtained composite particles, and FIG. 15B shows a photograph of a cross section thereof. It was confirmed that an outer shell composed of a monofunctional monomer and a crosslinkable monomer was formed, and that a porous structure in which silica particles were connected to each other was formed inside. The volume average particle diameter was 10.8 μm, and the weight of the porous structure in the composite particles was 24.0% by weight.

(Example 13)
Composite particles were obtained in the same manner as in Example 5, except that 8 g of hydrophobic fumed silica R812 (EVONIK, specific surface area according to BET method: 260 ± 30 m ² / g) was used as the hydrophobic silica particles. The viscosity of the mixture was 1.27 mPa · s. It was confirmed that an outer shell composed of a monofunctional monomer and a crosslinkable monomer was formed, and that a porous structure in which silica particles were connected to each other was formed inside. The volume average particle size was 11.5 μm, and the weight of the porous structure in the composite particles was 24.1% by weight.

(Example 14)
100 g of methyl methacrylate (MMA) as a monofunctional monomer, 100 g of ethylene glycol dimethacrylate (EGDMA) as a crosslinkable monomer, 200 g of tetraethoxysilane (TEOS) as a silica precursor, and 100 g of an inorganic thickener 4 g of smecton-STN (organized smectite manufactured by Kunimine Industries Co., Ltd.), 2 g of 2,2′-azobis (2,4-dimethylvaleronitrile) as a polymerization initiator (product name V-65, manufactured by Wako Pure Chemical Industries, Ltd.), Was prepared. The viscosity of the mixture was 0.91 mPa · s.
On the other hand, an aqueous phase was prepared by dissolving 60 g of polyvinyl alcohol (GL-05, manufactured by Nippon Synthetic Chemical Industry Co., Ltd.) as a suspension stabilizer in 1140 g of ion-exchanged water. The mixture was put into the aqueous phase, and emulsification / dispersion treatment was carried out at 5,000 rpm for 10 minutes using a homomixer (manufactured by Central Kagaku Trading Co., Ltd .; product name: Polytron homogenizer PT10-35). The obtained emulsion is charged into a 2 L pressure vessel with stirring blades, and the mixture is heated at 50 ° C. for 4 hours while stirring the stirring blades at 350 rpm, thereby comprising a monofunctional monomer and a crosslinkable monomer. An outer shell was formed. While maintaining the agitation, the internal temperature is cooled to 30 ° C., 65 g of 25% aqueous ammonia (Wako Pure Chemical Industries, Ltd.) is added, and the mixture is agitated for 16 hours to allow the gelation reaction of TEOS to proceed, thereby containing the composite particles. An emulsion was obtained. The obtained emulsion was subjected to suction filtration to take out composite particles from the emulsion. After repeated washing with water and purification, the composite particles were obtained by drying in a vacuum oven at 60 ° C.
FIG. 16 shows a cross-sectional photograph of the obtained composite particles. It was confirmed that an outer shell derived from the monofunctional monomer and the crosslinkable monomer was formed, and that a porous structure in which silica particles were connected to each other was formed inside. The volume average particle diameter was 11.5 μm, and the weight of silica in the composite particles was 22.1% by weight.

(Example 15)
Silica-encapsulated microcapsule resin particles were obtained in the same manner as in Example 14, except that 4 g of Kunibis-110 (organized bentonite) was used as an inorganic thickener. The viscosity of the mixture was 1.01 mPa · s.
FIG. 17 shows a cross-sectional photograph of the obtained composite particles. It was confirmed that an outer shell derived from the monofunctional monomer and the crosslinkable monomer was formed, and that a porous structure in which silica particles were connected to each other was formed inside. The volume average particle diameter was 13.5 μm, and the weight of silica in the composite particles was 21.9% by weight.

(Comparative Example 3)
80 g of methyl methacrylate (MMA) as a monofunctional monomer, 80 g of ethylene glycol dimethacrylate (EGDMA) as a crosslinkable monomer, 128 g of tetraethoxysilane (TEOS) as a silica precursor, 32 g of toluene as an organic solvent, 1.6 g of 2,2′-azobis (2,4-dimethylvaleronitrile) as a polymerization initiator (product name V-65, manufactured by Wako Pure Chemical Industries, Ltd.) and (1R, 2S, 5R) as a thermal acid generator 0.8 g of -5-methyl-2- (propan-2-yl) cyclohexyl 4-methylbenzenesulfonate (manufactured by Wako Pure Chemical Industries, Ltd .; product name: WPAG-699) was mixed and dissolved to prepare a mixture.
On the other hand, 20 g of polyvinyl alcohol (PVA) (manufactured by Nippon Gohsei; product name: Gohsenol GL-05) was dissolved in 1260 g of ion-exchanged water to prepare an aqueous phase. The mixture was put into the aqueous phase, and emulsification / dispersion treatment was carried out at 5000 rpm for 3 minutes using a homogenizer (manufactured by Central Kagaku Trading Co., Ltd .; product name: Polytron homogenizer PT10-35).
The obtained emulsion is put into a 2 L pressure vessel with a stirring blade, and the stirring blade is heated at 50 ° C. for 4 hours while being stirred at 350 rpm, thereby comprising a monofunctional monomer and a crosslinkable monomer. An outer shell was formed. While maintaining the stirring, the reaction temperature was raised to 105 ° C., and the mixture was heated for 2 hours to allow the gelation reaction of TEOS to proceed. Thereafter, the reaction system was cooled to room temperature to obtain an emulsion containing the composite particles.
The obtained composite particles were taken out of the emulsion by subjecting them to centrifugation and separation of the supernatant, repeatedly washed with water, purified, and dried in a vacuum oven at 60 ° C.
FIG. 18A shows a surface photograph of the obtained composite particles, and FIG. 18B shows a cross-sectional photograph thereof. It was confirmed that an outer shell composed of a monofunctional monomer and a crosslinkable monomer was formed, and that a porous structure in which silica particles were connected to each other was formed inside. The volume average particle diameter was 10.4 μm, and the weight of the porous structure in the composite particles was 17.2% by weight.

Table 2 summarizes the raw material species of Examples 5 to 15 and Comparative Example 3, the amount (g) used, and the viscosity of the mixture.

(Evaluation of reflection characteristics of ultraviolet, visible, and near-infrared light)
The reflectance of the composite particles with respect to ultraviolet light, visible light and near-infrared light was evaluated according to the following procedure.
2.5 g of composite particles were added to 10 g of a commercially available water-based paint (trade name of Asahipen Co .; water-based multi-purpose color clear), and the mixture was stirred well to disperse the particles to prepare a paint for evaluation.
The paint for evaluation was applied to the black side of the opacity test paper using an applicator set to a wet thickness of 250 μm, and then sufficiently dried at room temperature to obtain a sample plate for light reflectivity evaluation.
The reflectance of the sample plate to ultraviolet light, visible light, and near-infrared light was evaluated in the following order.
An ultraviolet-visible-near-infrared spectrophotometer (Solid Spec 3700) manufactured by Shimadzu Corporation was used as a reflectivity measuring device to measure the reflection characteristics from ultraviolet light to near-infrared light (wavelength 300 to 2500 nm) on the coated surface of the sample plate. It was measured as reflectivity (%). The measurement was carried out using a 60 mmΦ integrating sphere and using Spectralon as a standard white plate. The results obtained are shown in FIG.
From FIG. 19, it can be seen that the composite particles of the examples have a high reflectivity at almost all wavelengths from ultraviolet light to near-infrared light similar to that of Comparative Example 3 without using an organic solvent such as toluene. Understand.

(Production Example 1 of coating composition)
2 parts by weight of the composite particles obtained in Example 1 and 20 parts by weight of a commercially available acrylic water-based glossy paint (manufactured by Campe Papio Co., Ltd., trade name: Superhit) were mixed for 3 minutes using a stirring and defoaming apparatus. By defoaming for 1 minute, a coating composition was obtained.
The obtained coating composition was applied on an ABS resin (acrylonitrile-butadiene-styrene resin) plate using a coating device equipped with a blade having a clearance of 75 μm, and then dried to obtain a coating film.

(Production Example 2 of coating composition)
2 parts by weight of the composite particles obtained in Example 5 and 20 parts by weight of a commercially available acrylic water-based glossy paint (manufactured by Campe Papio Co., Ltd., trade name: Superhit) were mixed for 3 minutes using a stirring and defoaming apparatus. The coating composition was obtained by defoaming for 1 minute.
The obtained coating composition was applied on an ABS resin (acrylonitrile-butadiene-styrene resin) plate using a coating device equipped with a blade having a clearance of 75 μm, and then dried to obtain a coating film.

(Production Example 1 of light diffusing resin composition and light diffusing film)
7.5 parts by weight of the composite particles obtained in Example 1, 30 parts by weight of an acrylic resin (manufactured by DIC, product name Acridic A811), 10 parts by weight of a crosslinking agent (manufactured by DIC, product name VM-D), 50 parts by weight of butyl acetate as a solvent was mixed for 3 minutes using a stirring and defoaming apparatus, and defoamed for 1 minute to obtain a light diffusing resin composition.
The obtained light-diffusing resin composition was coated on a 125-μm-thick PET film using a coating device equipped with a blade with a clearance of 50 μm, and then dried at 70 ° C. for 10 minutes to form a light-diffusing film. Obtained.

(Production Example 2 of light diffusing resin composition and light diffusing film)
7.5 parts by weight of the composite particles obtained in Example 5, 30 parts by weight of an acrylic resin (manufactured by DIC, product name Acridic A811), 10 parts by weight of a crosslinking agent (manufactured by DIC, product name VM-D), 50 parts by weight of butyl acetate as a solvent was mixed for 3 minutes using a stirring and defoaming apparatus, and defoamed for 1 minute to obtain a light diffusing resin composition.
The obtained light-diffusing resin composition was coated on a 125-μm-thick PET film using a coating device equipped with a blade with a clearance of 50 μm, and then dried at 70 ° C. for 10 minutes to form a light-diffusing film. Obtained.

(Example of cosmetic formulation)
(Formulation Example 1)
Production and blending amount of powder foundation Composite particles obtained in Example 1 10.0 parts by weight Red iron oxide 3.0 parts by weight Yellow iron oxide 2.5 parts by weight Black iron oxide 0.5 parts by weight Titanium oxide 10.0 Parts by weight Mica 20.0 parts by weight Talc 44.0 parts by weight Liquid paraffin 5.0 parts by weight Octyldodecyl myristate 2.5 parts by weight Vaseline 2.5 parts by weight Preservatives proper amount perfume proper amount / production method , Yellow iron oxide, black iron oxide, titanium oxide, mica, and talc are mixed with a Henschel mixer, and a mixture obtained by mixing and dissolving liquid paraffin, octyldodecyl myristate, vaseline, and a preservative is added and uniformly mixed. After adding a fragrance to the mixture and mixing, the mixture is pulverized and passed through a sieve. This is compression-molded on a metal plate to obtain a powder foundation.

(Formulation Example 2)
Production and Compounding Amount of Cosmetic Emulsion 10.0 parts by weight of composite particles obtained in Example 1 2.5 parts by weight of stearic acid 1.5 parts by weight of cetyl alcohol 5.0 parts by weight of petrolatum 10.0 parts by weight of liquid paraffin 10.0 parts by weight of polyethylene ( 10 mol) Monooleate 2.0 parts by weight Polyethylene glycol 1500 3.0 parts by weight Triethanolamine 1.0 part by weight Purified water 64.5 parts by weight Fragrance 0.5 part by weight Preservatives Appropriate amount / production method First, stearin The acid, cetyl alcohol, petrolatum, liquid paraffin, and polyethylene monooleate are heated and dissolved, and the composite particles are added and mixed therein, and the mixture is kept at 70 ° C. (oil phase). Further, polyethylene glycol and triethanolamine are added to purified water, dissolved by heating, and kept at 70 ° C. (aqueous phase). The oil phase is added to the water phase, preliminarily emulsified, and thereafter uniformly emulsified with a homogenizer. After emulsification, the emulsion is cooled to 30 ° C. with stirring to obtain a cosmetic emulsion.

(Formulation Example 3)
Manufacture and blending amount of powder foundation Composite particles obtained in Example 5 10.0 parts by weight Red iron oxide 3.0 parts by weight Yellow iron oxide 2.5 parts by weight Black iron oxide 0.5 parts by weight Titanium oxide 10.0 Parts by weight Mica 20.0 parts by weight Talc 44.0 parts by weight Liquid paraffin 5.0 parts by weight Octyldodecyl myristate 2.5 parts by weight Vaseline 2.5 parts by weight Preservatives proper amount perfume proper amount / production method , Yellow iron oxide, black iron oxide, titanium oxide, mica, and talc are mixed with a Henschel mixer, and a mixture obtained by mixing and dissolving liquid paraffin, octyldodecyl myristate, vaseline, and a preservative is added and uniformly mixed. After adding a fragrance to the mixture and mixing, the mixture is pulverized and passed through a sieve. This is compression-molded on a metal plate to obtain a powder foundation.

(Formulation Example 4)
Production and Compounding Amount of Cosmetic Emulsion 10.0 parts by weight of composite particles obtained in Example 5 2.5 parts by weight of stearic acid 1.5 parts by weight of cetyl alcohol 5.0 parts by weight of vaseline 10.0 parts by weight of liquid paraffin Polyethylene ( 10 mol) Monooleate 2.0 parts by weight Polyethylene glycol 1500 3.0 parts by weight Triethanolamine 1.0 part by weight Purified water 64.5 parts by weight Fragrance 0.5 part by weight Preservatives Appropriate amount / production method First, stearin The acid, cetyl alcohol, petrolatum, liquid paraffin, and polyethylene monooleate are heated and dissolved, and the composite particles are added and mixed therein, and kept at 70 ° C. (oil phase). Further, polyethylene glycol and triethanolamine are added to purified water, dissolved by heating, and kept at 70 ° C. (aqueous phase). The oil phase is added to the water phase, preliminarily emulsified, and thereafter uniformly emulsified by a homomixer. After emulsification, the emulsion is cooled to 30 ° C. with stirring to obtain a cosmetic emulsion.

Claims

A porous structure comprising an outer shell made of a cross-linked polymer, and a cavity partitioned by the outer shell, in which a silica structure as first inorganic particles is connected to each other; Organic-inorganic composite particles comprising a second inorganic particle other than the above, and having a volume average particle diameter of 0.5 to 100 μm.
The organic-inorganic composite particles according to claim 1, wherein the second inorganic particles have a refractive index of 1.8 or more.
3. The organic-inorganic composite particles according to claim 1, wherein the second inorganic particles have a particle diameter of 0.001 to 3 μm measured by a dynamic light scattering method.
4. The method according to claim 1, wherein the first inorganic particles and the second inorganic particles have a content of 5 to 50% by weight based on the total weight of the organic-inorganic composite particles, and provide the hollow structure with a hollow structure. Organic-inorganic composite particles according to the above item.
The organic-inorganic composite particles according to any one of claims 1 to 4, wherein the second inorganic particles are particles selected from titanium oxide, zirconium oxide, cerium oxide, zinc oxide, niobium oxide, and zirconium silicate. .
<6> A cosmetic containing the organic-inorganic composite particles according to any one of claims 1 to 5.
(6) A coating composition containing the organic-inorganic composite particles according to any one of (1) to (5).
(6) A heat-insulating resin composition containing the organic-inorganic composite particles according to any one of (1) to (5).
<6> A light diffusing resin composition containing the organic-inorganic composite particles according to any one of <1> to <5>.
(6) A light diffusion film containing the organic-inorganic composite particles according to any one of (1) to (5).
A method for producing organic-inorganic composite particles according to any one of claims 1 to 5,
100 parts by weight of a radical polymerizable monofunctional monomer and 20 to 150 parts by weight of a crosslinkable monomer, 60 to 400 parts by weight of a silicon alkoxide as a silica precursor, and 0.1 to 10 parts by weight of a second inorganic particle And a mixture comprising a part and a suspension polymerization in an aqueous medium in the presence of a radical polymerization initiator to form an outer shell composed of a crosslinked polymer and a cavity defined by the outer shell. ,
Gelling the silicon alkoxide after or simultaneously with the formation of the outer shell to form a porous structure in which silica particles are connected to each other inside the cavity. A method for producing organic-inorganic composite particles.
The gelation is carried out by using an acid or a base in the cavity defined by the outer shell as a catalyst, and the acid or the base is generated by external stimulation by energy radiation or heat of the latent pH adjuster, and the latent pH is reduced. The method for producing organic-inorganic composite particles according to claim 11, wherein the modifier is present in the cavity by dissolving the latent pH modifier in the mixture during the suspension polymerization.
A mixture containing a radically polymerizable monofunctional monomer and a crosslinkable monomer, a silicon alkoxide as a silica precursor, and an inorganic thickener is mixed in the presence of a radical polymerization initiator and in the absence of an organic solvent. A step of forming an outer shell composed of a crosslinked polymer by suspension polymerization in an aqueous medium,
Forming a porous structure in which silica particles are connected to each other inside the outer shell from silicon alkoxide after or simultaneously with the formation of the outer shell from the silicon alkoxide. Manufacturing method.
The method for producing organic-inorganic composite particles according to claim 13, wherein the mixture has a viscosity of 0.90 mPa · s or more at 25 ° C.
The method for producing organic-inorganic composite particles according to claim 13 or 14, wherein the inorganic thickener is silicic anhydride or a clay mineral.
16. The method for producing organic-inorganic composite particles according to any one of claims 13 to 15, wherein the porous structure in which the silica particles are connected to each other exhibits a carbon component in EDX measurement.
17. The organic material according to claim 15, wherein the inorganic thickener is hydrophobic silica particles that are silicic anhydride, and the hydrophobic silica particles have a specific surface area of 15 to 330 m 2 / g by a BET method. A method for producing inorganic composite particles.
18. The method for producing organic-inorganic composite particles according to any one of claims 13 to 17, wherein the organic-inorganic composite particles have a volume average particle diameter of 0.5 to 100 μm.
19. The method for producing organic-inorganic composite particles according to any one of claims 13 to 18, wherein the porous structure has 5 to 50% by weight based on the total weight of the organic-inorganic composite particles.
20. The method for producing organic-inorganic composite particles according to any one of claims 17 to 19, wherein the hydrophobic silica particles are contained in the mixture in an amount of 0.5 to 100 parts by weight based on 100 parts by weight of the mixture.
The mixture according to any one of claims 13 to 20, wherein the monofunctional monomer includes 100 parts by weight, the crosslinkable monomer includes 20 to 150 parts by weight, and the silica precursor includes 60 to 400 parts by weight. A method for producing the organic-inorganic composite particles according to the above.