JP2021023846A - Hollow particle and production method of the same - Google Patents

Abstract

To provide a hollow particle having excellent light-diffusibility.SOLUTION: The problem is solved by a hollow particle which includes a nonporous shell and a hollow region partitioned by the shell, in which the shell has a plurality of protrusions on its inside wall, the plurality of protrusions are connected together, and the hollow particle is characterized as having W/V of 0.02-0.5 (W means an average width of the plurality of protrusions and V means a volume average particle diameter of the hollow particle).SELECTED DRAWING: Figure 4

Description

The present invention relates to hollow particles and a method for producing the same. More specifically, the present invention relates to hollow particles having a plurality of protrusions on the inner wall of a shell constituting the hollow particles, and a method for producing the same. The hollow particles of the present invention are suitable for applications such as paint compositions, cosmetics, paper coating compositions, heat insulating compositions, light diffusing compositions, and light diffusing films.

Polymer particles (hollow particles) having an airspace inside are used in an extremely wide range of fields for the purpose of imparting weight reduction, pore formation, heat insulation, sound insulation, impact resistance, and the like of a material.
It is known that visible light is scattered by the difference in refractive index between the shell and the airspace partitioned by the shell, and the hollow particles are superior to polymer particles (solid particles) having no airspace inside. It has diffusivity. For this reason, hollow particles have the effect of improving opacity, whiteness, gloss, etc., and are therefore used, for example, as light diffusing agents in paints, paper coating compositions, cosmetics, sunscreen creams, and the like. In particular, in recent years, from the viewpoint of energy saving, it has been studied to apply a heat-shielding paint or a heat-insulating paint to the roof of a building, and as a material for improving the heat-shielding property and the heat-insulating property, a hollow having excellent light dispersal property. The use of particles is being considered.
As the hollow particles, the particles described in JP-A-2002-08503 (Patent Document 1) have been proposed. Further, in International Publication No. 2002/072671 (Patent Document 2) and JP-A-2017-0815252 (Patent Document 3), hollow particles having improved mechanical strength by making the internal morphology porous have been proposed. There is.

JP-A-2002-08503 International Publication No. 2002/072671 Japanese Unexamined Patent Publication No. 2017-0815252

The hollow particles described in Patent Document 1 cannot be said to have sufficient light scattering in the airspace, and in particular, have insufficient diffusivity from visible light to near-infrared light. As a result, it did not have sufficient performance as a material for improving heat shielding properties. Further, the hollow particles described in Patent Documents 2 and 3 have improved light scattering as compared with Patent Document 1, but have insufficient diffusivity of near-infrared light. Therefore, hollow particles having improved light diffusivity have been required.

Thus, according to the present invention, the shell comprises a non-porous shell and an airspace partitioned by the shell, the shell having a plurality of protrusions on its inner wall, and the plurality of protrusions are connected to each other. Hollow particles,
The hollow particles are characterized by having a W / V of 0.02 to 0.5 (W means the average width of a plurality of protrusions, and V means the volume average particle diameter of the hollow particles). Particles are provided.
Further, according to the present invention, it is the above-mentioned method for producing hollow particles.
A mixture containing a vinyl-based monofunctional monomer, a vinyl-based crosslinkable monomer, a non-reactive solvent, and a polymerization initiator is mixed in an aqueous medium containing a suspension stabilizer in the presence of a dispersion aid. Provided is a method for producing hollow particles, which comprises a step of polymerizing.

According to the present invention, it is possible to provide hollow particles having excellent light diffusivity (particularly, light scattering property of visible light and near infrared light).
Further, in any of the following cases, it is possible to provide hollow particles having better light diffusivity.
(1) The hollow particles have a volume average particle diameter of 1.0 to 50 μm, and the shell is composed of a crosslinked resin.
(2) The crosslinked resin is derived from a vinyl-based monofunctional monomer and a vinyl-based crosslinkable monomer, and the vinyl-based monofunctional monomer and the vinyl-based crosslinkable monomer are (meth) acrylic acid. It is an ester.
(3) Hollow particles have the property of reflecting visible light and near-infrared light.
(4) Hollow particles are used in applications selected from paint compositions, cosmetics, paper coating compositions, heat insulating compositions, light diffusing compositions and light diffusing films.

It is a surface photograph (3000 times) and a cross-sectional photograph (3000 times and 1000 times) of the hollow particles of Examples 1 to 4. It is a surface photograph (3000 times) and a cross-sectional photograph (3000 times and 1000 times) of the hollow particles of Examples 5-8. Surface photographs (3000 times) and cross-sectional photographs of the hollow particles of Examples 9 and Comparative Examples 1 to 3 (Comparative Examples 1 are 3000 times and 1000 times, Comparative Examples 1 and 2 are 3000 times). It is a graph which shows the light reflectance for each wavelength of the coating film containing each hollow particle of the Example and the comparative example in the evaluation of the reflection characteristic of ultraviolet-visible near-infrared light.

(Hollow particles)
Hollow particles include a non-porous shell and airspace partitioned by the shell. Further, the shell has a plurality of protrusions on its inner wall. Further, the plurality of protrusions are connected to each other.

(1) Shell The material constituting the shell is not particularly limited as long as the airspace can be partitioned. The material may include a crosslinked resin. The material does not have to contain an inorganic component (eg, silica).
The type of the crosslinked resin is not particularly limited as long as it can form a shell. Examples of the crosslinked resin include resins derived from vinyl-based monomers, and specific examples thereof include resins derived from vinyl-based monofunctional monomers and vinyl-based crosslinkable monomers. The vinyl-based monofunctional monomer is a monomer having one vinyl group, and the vinyl-based crosslinkable monomer is a monomer having two or more vinyl groups. The fact that the shell is made of crosslinked resin can be confirmed, for example, by measuring the gel fraction.
Examples of the vinyl-based monofunctional monomer include alkyl (meth) acrylic acid esters having 1 to 16 carbon atoms such as methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, and cetyl (meth) acrylate. (Meta) acrylonitrile, dimethylmaleate, dimethylfumarate, diethylfumarate, ethylfumarate, maleic anhydride, N-vinylcarbazole; styrene, α-methylstyrene, paramethylstyrene, vinyltorene, chlorostyrene, ethylstyrene , Styrene-based monomers such as i-propylstyrene, dimethylstyrene, bromostyrene and the like. These monofunctional monomers can be used alone or in combination of two or more.

Examples of the vinyl-based crosslinkable monomer include polyfunctional (meth) acrylic acid esters such as ethylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, and glycerin tri (meth) acrylate, N, N'-. Examples include polyfunctional acrylamide derivatives such as methylenebis (meth) acrylamide and N, N'-ethylenebis (meth) acrylamide, polyfunctional allyl derivatives such as diallylamine and tetraaryloxyethane, and aromatic divinyl compounds such as divinylbenzene. Be done. These crosslinkable monomers can be used alone or in combination of two or more.
The vinyl-based monofunctional monomer and the vinyl-based crosslinkable monomer are preferably (meth) acrylic acid esters.

The component derived from the vinyl-based crosslinkable monomer is preferably contained in the shell at a ratio of 20 parts by weight or more with respect to 100 parts by weight of the component derived from the vinyl-based monofunctional monomer. If the amount of the component derived from the crosslinkable monomer is less than 20 parts by weight, a shell having sufficient strength may not be formed. The amount of the component derived from the vinyl-based crosslinkable monomer is more preferably 20 to 150 parts by weight, further preferably 80 to 130 parts by weight.

(2) Protrusions on the inner wall The shell has a plurality of protrusions on the inner wall. The number of protrusions is not particularly limited. For example, the number of protrusions in contact with the inner wall of the shell can be two or more in the cross section of the hollow particles, and can be in the range of 2 to 1600. Further, the plurality of protrusions are connected to each other between adjacent protrusions. It can be confirmed from the cross-sectional photograph of the hollow particles that they are connected to each other.
The protrusions are W / V of 0.02 to 0.5 with respect to the volume average particle size of the hollow particles (W means the average width of a plurality of protrusions, and V means the volume average particle size of the hollow particles. ). If W / V is less than 0.02 or greater than 0.5, the light diffusivity may be insufficient. The W / V is preferably 0.025 to 0.4, and more preferably 0.03 to 0.3.
The volume average particle diameter V can be 1.0 to 50 μm. Although it depends on the application, the volume average particle size is preferably 2.0 to 30 μm, more preferably 3.0 to 25 μm.
The average width W of the protrusions can be 0.1 to 2.0 μm. The average width is preferably 0.2 to 1.5 μm, more preferably 0.3 to 1.0 μm.
The protrusions may be made of the same material that constitutes the shell.

(3) Outer shape, etc. The outer shape of the hollow particles is not particularly limited, but it is preferably as close to a spherical shape as possible.
The shell has a thickness of 0.1 to 2.0 μm. If the thickness is less than 0.1 μm, the hollow particles may be easily crushed. If it is larger than 2.0 μm, the reflectivity of visible light and near-infrared light may decrease. The thickness is preferably 0.2 to 1.5 μm, more preferably 0.3 to 1.0 μm.
The shell is non-porous. Since the hollow particles are non-porous, the airspace can be maintained even if the hollow particles are used for various purposes, so that the light diffusivity of the hollow particles can be exhibited. The non-porous nature can be confirmed, for example, by checking whether or not a resin for fixing the hollow particles is present in the airspace when taking a cross-sectional photograph of the hollow particles.
In the airspace, a particle mass composed of a plurality of particles connected to each other may exist. The particle mass of the hollow particles may be connected to the adjacent protrusions.

(Manufacturing method of hollow particles)
The method for producing hollow particles is to suspend and stabilize a mixture containing a vinyl-based monofunctional monomer, a vinyl-based crosslinkable monomer, a non-reactive solvent, and a polymerization initiator in the presence of a dispersion aid. It includes a step of polymerizing in an aqueous medium containing an agent (polymerization step).

(1) Polymerization Step In the polymerization step, the vinyl-based monofunctional monomer and the vinyl-based crosslinkable monomer are polymerized, and the produced polymer is collected at the interface with the aqueous medium to obtain hollow particles.
In the polymerization step, first, at least a vinyl-based monofunctional monomer, a vinyl-based crosslinkable monomer, a non-reactive solvent, and a polymerization initiator are mixed to obtain a mixture. The amount of the monomer used and the content of the monomer-derived components constituting the outer shell are substantially the same.
Examples of the non-reactive solvent include 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 and the like. Can be mentioned. These non-reactive organic solvents can be used alone or in combination of two or more. The boiling point of the non-reactive solvent is preferably less than 100 ° C. because it can be easily removed from the hollow particles.
The amount of the non-reactive solvent added is not particularly limited, but is 40 to 250 parts by weight with respect to 100 parts by weight of all the monomers. If the amount added is less than 40 parts by weight, the proportion of the airspace partitioned by the shell becomes small, and the light diffusivity may be insufficient. If it exceeds 250 parts by weight, the formation of the shell becomes insufficient, and particles having sufficient physical strength may not be obtained.

Polymerization of the monomer is carried out in the presence of a polymerization initiator. The polymerization initiator is not particularly limited, and for example, persulfates such as ammonium persulfate, potassium persulfate, and sodium persulfate, etc.
Cumenhydroperoxide, di-tert-butyl peroxide, dicumyl peroxide, benzoyl peroxide, lauroyl peroxide, dimethylbis (tert-butylperoxy) hexane, dimethylbis (tert-butylperoxy) hexin-3, Bis (tert-butylperoxyisopropyl) benzene, bis (tert-butylperoxy) trimethylcyclohexane, butyl-bis (tert-butylperoxy) valerate, 2-ethylhexaneperoxyate tert-butyl, dibenzoyl peroxide, para Organic peroxides such as mentan hydroperoxide, tert-butyl peroxybenzoate,
2,2'-Azobisisobuty [2- (2-imidazolin-2-yl) propane] dihydrochloride, 2,2'-azobis [2- (2-imidazolin-2-yl) propane] disulfate dihydration , 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'-azobisiso Butyronitrile (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-trimethylbutyronitrile) , 2,2'-azobis (2,4,4-trimethylvaleronitrile), 2,2'-azobis (2,4-dimethylvaleronitrile), 2,2'-azobis (2,4-dimethyl-4-4) 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-methylpro) Pinate), dimethyl-2,2'-azobisisobutyrate, dimethyl-2,2'-azobis (2-methylpropinate), 2- (carbamoylazo) isobutyronitrile, 4,4'-azobis Examples thereof include azo compounds such as su (4-cyanovaleric acid). 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 all the monomers.
Next, in the dispersed mixture, hollow particles are obtained by subjecting the monomers in the dispersion to polymerization. The polymerization is not particularly limited, and is carried out while appropriately adjusting various conditions such as the polymerization temperature and the polymerization time according to the type 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.
Thickeners may be added to the mixture. 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 hydrophobic fumed silica and clay minerals. Only one type of these thickeners may be added, or two or more types may be added.

The mixture is added to an aqueous medium containing a suspension stabilizer.
Examples of the aqueous medium constituting the aqueous medium include water, a mixture of water and a water-soluble organic solvent (for example, a lower alcohol such as methanol or ethanol).
Examples of the suspension stabilizer include phosphates such as calcium phosphate, magnesium phosphate, aluminum phosphate and zinc phosphate, pyrophosphates such as calcium pyrophosphate, magnesium pyrophosphate, aluminum pyrophosphate and zinc pyrophosphate, and calcium carbonate. , Magnesium carbonate, calcium hydroxide, magnesium hydroxide, aluminum hydroxide, calcium metasilicate, calcium sulfate, barium sulfate, colloidal silica and other poorly water-soluble inorganic compounds. Suspension stabilizers can be used alone or in combination of two or more.
The suspension stabilizer is preferably used in an amount of 0.5 to 10 parts by weight based on 100 parts by weight of the mixture of all the monomers and the non-reactive solvent. If the amount used is less than 0.5 parts by weight, the mixture may not be sufficiently dispersed. If the amount used is more than 10 parts by weight, the effect corresponding to the amount used cannot be obtained and it is uneconomical in terms of cost, which is not preferable.

The polymerization is carried out in the presence of a dispersion aid. The dispersion aid may be present in the mixture or in an aqueous medium.
As dispersion aids, lauryl phosphoric acid, polyoxyethylene (1) lauryl ether phosphoric acid, dipolyoxyethylene (2) alkyl ether phosphoric acid, dipolyoxyethylene (4) alkyl ether phosphoric acid, dipolyoxyethylene ( 6) Alkyl ether phosphoric acid, dipolyoxyethylene (8) alkyl ether phosphoric acid, dipolyoxyethylene (4) nonylphenyl ether phosphoric acid, caprolactone EO modified phosphoric acid dimethacrylate, 2-methacryloyloxyethyl acid phosphate, etc. Can be mentioned. (Number) means the number of repetitions of oxyethylene. EO means ethylene oxide.
The amount of the dispersion aid added is not particularly limited, but is 0.0001 to 0.5 parts by weight with respect to 100 parts by weight of the mixture of all the monomers and the non-reactive solvent. If the amount added is less than 0.0001 parts by weight, the mixture may not be sufficiently dispersed. If it exceeds 0.5 parts by weight, the shell may not be formed.

The inventors believe that the hollow particles having a unique shape of the present invention can be appropriately produced by controlling the interfacial tension acting on the interface composed of the mixture (oil phase) and the aqueous medium (aqueous phase). .. For example, when the interfacial tension is large, the number of protrusions tends to decrease and / or the size of the protrusions tends to increase. Further, when the interfacial tension is small, the number of protrusions tends to increase and / or the size of the protrusions tends to decrease. The interfacial tension between the mixture (oil phase) and the aqueous medium (aqueous phase) is, for example, the type of non-reactive solvent used, the ratio of all monomers to the non-reactive solvent, the amount of dispersant, and the amount of dispersion aid. Can be controlled by adjusting.
In addition, the inventors believe that the hollow particles having a unique shape of the present invention can be appropriately produced by adjusting the viscosity of the mixture (oil phase). When the viscosity of the mixture (oil phase) is high, the number of protrusions tends to increase and / or the size of the protrusions tends to decrease. When the viscosity of the mixture (oil phase) is low, the number of protrusions tends to decrease and / or the size of the protrusions tends to increase. For example, even when the interfacial tension is large, by increasing the viscosity of the mixture (oil phase), hollow particles having a large number of protrusions and / or a small protrusion size may be obtained.
The mixture is dispersed in an aqueous medium while appropriately adjusting various conditions such as stirring speed and stirring time so that hollow particles having a desired particle size can be obtained.
(2) Other Steps Hollow particles can be taken out from an aqueous medium by undergoing centrifugation, washing with water and drying, if necessary.

(Use)
The hollow particles can be used in applications such as paint compositions, cosmetics, paper coating compositions, heat insulating compositions, light diffusing compositions, and light diffusing films.

(1) Paint, heat insulating and light diffusing composition These compositions include a binder resin, a UV curable resin, a solvent and the like, if necessary. As the binder resin, an organic solvent, a resin soluble in water, or an emulsion-type aqueous resin that can be dispersed in water can be used.
The amount of the binder resin or UV curable resin and hollow particles added also depends on the film thickness of the coating film to be formed, the average particle size of the hollow particles, and the coating method. The amount of the hollow particles added is preferably 5 to 50% by weight based on the total of the binder resin (solid content when an emulsion type aqueous resin is used) and the hollow particles. A more preferable content is 10 to 50% by weight, and a more preferable content is 20 to 40% by weight.
Examples of the binder resin include acrylic resin, alkyd resin, polyester resin, polyurethane resin, chlorinated polyolefin resin, and amorphous polyolefin resin, and examples of the UV curable resin include polyvalent alcohol polyfunctional (meth) acrylate and the like. Functional (meth) acrylate resin; examples thereof include polyfunctional urethane acrylate resin synthesized from diisocyanate, polyhydric alcohol, (meth) acrylic acid ester having a hydroxy group, and the like.

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. Specific examples of the polyvalent alcohol polyfunctional (meth) acrylate resin having three or more (meth) acryloyl groups in one molecule include trimethylolpropantri (meth) acrylate and trimethylol ethanetri (meth) acrylate. , 1,2,4-Cyclohexanetetra (meth) acrylate, pentaglycerol triacrylate, pentaerythritol tetra (meth) acrylate, pentaerythritol tri (meth) acrylate, dipentaerythritol triacrylate, dipentaerythritol pentaacrylate, dipentaerythritol Examples thereof include tetra (meth) acrylate, dipentaerythritol hexa (meth) acrylate, tripentaerythritol triacrylate, and tripentaerythritol hexaacrylate, which may be used alone or in combination of two or more.

When a UV curable resin is used, 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. Classes (described in JP-A-2001-139663, etc.), 2,3-dialkyldione compounds, disulfide compounds, fluoroamine compounds, aromatic sulfoniums, onium salts, borate salts, active halogen compounds, α-acyloxy. Examples include muesters.
These binder resins or UV curable resins can be appropriately selected depending on the adhesion of the coating material to the substrate to be coated, the environment in which the coating material is used, and the like.

The solvent is not particularly limited, but it is preferable to use a solvent capable of dissolving or dispersing a binder resin or a 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 thereof include ether solvents such as monobutyl ether. If it is a water-based paint, water, alcohol, etc. can be used. These solvents may be used alone or in combination of two or more. The solvent content 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, known coating surface adjusting agents, fluidity adjusting agents, ultraviolet absorbers, light stabilizers, curing catalysts, extender pigments, coloring pigments, metal pigments, mica powder pigments, dyes and the like. It may be.
The method for forming the coating film using the composition is not particularly limited, and any known method can be used. For example, a spray coating method, a roll coating method, a brush coating method, etc., and a coating reverse roll coating method, a gravure coating method, a die coating method, a comma coating method, a spray coating method for coating a substrate such as a film as a thin layer. Can be mentioned. The composition may be diluted if necessary to adjust the viscosity. As the diluent, hydrocarbon solvents such as toluene and xylene; ketone solvents such as methyl ethyl ketone and methyl isobutyl ketone; ester solvents such as ethyl acetate and butyl acetate; ether solvents such as dioxane and ethylene glycol diethyl ether; water. ; Alcohol-based solvent and the like can be mentioned. These diluents may be used alone or in combination of two or more.
A coating film can be formed by applying a coating film to an arbitrary coating surface such as a base material to prepare a coating film, drying the coating film, and then curing the coating film as necessary. The coating film using the coating composition is used by coating various base materials, and is not particularly limited to metal, wood, glass, plastics and the like. Further, it can be used by coating it on a transparent base material such as polyethylene terephthalate (hereinafter abbreviated as PET), polyethylene carbonate (hereinafter abbreviated as PC), and acrylic.

(2) Cosmetics Cosmetics preferably contain hollow particles in the range of 1 to 40% by weight.
Cosmetics include cleaning cosmetics such as soap, body shampoo, face wash cream, scrub pigment, lotion, cream, milky lotion, packs, shave, foundation, lipstick, lip cream, cheek red, eyebrow cosmetics, manicure cosmetics, Hair wash cosmetics, hair dyes, hair conditioners, aromatic cosmetics, toothpaste, bathing agents, antiperspirants, sunscreen products, suntan products, body powders, baby powders and other body cosmetics, shaving creams, pre-shave lotions, Examples include aftershave lotions and lotions such as body lotions.

In addition, ingredients generally used in cosmetics can be blended according to the purpose as long as the effects of the present invention are not impaired. Such components include, for example, water, lower alcohols, fats and oils, waxes, hydrocarbons, higher fatty acids, higher alcohols, sterols, fatty acid esters, metal soaps, moisturizers, surfactants, polymer compounds, colorant raw materials, etc. Examples include fragrances, antiseptic / bactericidal agents, antioxidants, UV absorbers, and special compounding ingredients.
Oils and waxes include avocado oil, almond oil, olive oil, cacao oil, beef oil, sesame oil, wheat germ oil, saflower oil, shea butter, turtle oil, camellia oil, persic oil, castor oil, grape oil, macadamia nut oil, mink. Examples thereof include oil, egg yolk oil, mokuro, palm oil, rose hip oil, hardened oil, silicone oil, orange raffy oil, carnauba wax, candelilla wax, whale wax, jojoba oil, montan wax, honey wax and lanolin.
Examples of the hydrocarbon include liquid paraffin, petrolatum, paraffin, selecin, microcrystalline wax, squalane and the like. Examples of 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 acid.

Higher alcohols include lauryl alcohol, cetyl alcohol, cetostearyl alcohol, stearyl alcohol, oleyl alcohol, behenyl alcohol, lanolin alcohol, hydrogenated lanolin alcohol, hexyldecanol, octyldecanol, isostearyl alcohol, jojoba alcohol, and decyltetradeca. Examples include alcohol.
Examples of sterols include cholesterol, dihydrocholesterol, phytocholesterol and the like.
Examples of fatty acid esters include ethyl linoleate, isopropyl myristate, isopropyl lanolin fatty acid, hexyl laurate, myristyl myristate, cetyl myristate, octyldodecyl myristate, decyl oleate, octyldodecyl oleate, hexadecyl dimethyloctanoate, and isooctanoic acid. Cetyl, decyl palmitate, glycerin trimyristate, glycerin tri (caprylic capric acid), propylene glycol dioleate, glycerin triisostearate, glycerin triisooctanoate, cetyl lactate, myristyl lactate, diisostearyl malate and cholesteryl isostearate , 12-Cycholic alcohol fatty acid esters such as cholesteryl hydroxystearate, and the like.

Examples of the metal soap include zinc laurate, zinc myristate, magnesium myristate, zinc palmitate, zinc stearate, aluminum stearate, calcium stearate, magnesium stearate, zinc undecylene and the like.
Examples of the moisturizer include glycerin, propylene glycol, 1,3-butylene glycol, polyethylene glycol, sodium dl-pyrrolidone carboxylate, sodium lactate, sorbitol, sodium hyaluronate, polyglycerin, xylit, and maltitol.
Examples of the surfactant include anionic surfactants such as higher fatty acid soap, higher alcohol sulfate ester, N-acylglutamate and phosphate ester salt, cationic surfactants such as amine salt and quaternary ammonium salt, and betaine. Amphoteric surfactants such as type, amino acid type, imidazoline type and lecithin, 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 Can be mentioned.

Examples of the polymer compound include natural polymer compounds such as Arabic rubber, tragant gum, guar gum, locust bean gum, karaya gum, iris moss, quince seed, gelatin, cellac, rosin, and casein, sodium carboxymethyl cellulose, hydroxyethyl cellulose, methyl cellulose, and ethyl cellulose. Semi-synthetic polymer compounds such as sodium alginate, ester gum, nitrocellulose, hydroxypropyl cellulose, crystalline cellulose, polyvinyl alcohol, polyvinylpyrrolidone, sodium polyacrylate, carboxyvinyl polymer, polyvinyl methyl ether, polyamide resin, silicone oil, nylon particles , Synthetic polymer compounds such as resin particles such as polymethyl methacrylate particles, crosslinked polystyrene particles, silicone particles, urethane particles, polyethylene particles, and silica particles.

As raw materials for coloring materials, iron oxide, ultramarine blue, corn, chromium oxide, chromium hydroxide, carbon black, manganese violet, titanium oxide, zinc oxide, talc, kaolin, mica, calcium carbonate, magnesium carbonate, mica, aluminum silicate, Barium silicate, calcium silicate, magnesium silicate, silica, zeolite, barium sulfate, calcined calcium sulfate (baked sekko), calcium phosphate, hydroxyapatite, inorganic pigments such as ceramic powder, azo, nitro, nitroso, xanthene , Kinolin-based, anthraquinolin-based, indigo-based, triphenylmethane-based, phthalocyanine-based, pyrene-based and other tar pigments.

Here, the powder raw material such as the polymer compound and the color material raw material may be surface-treated in advance. As a 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. , Fluorine compound treatment with a polymer having a perfluoroalkyl group, silane coupling agent treatment with 3-methacryloxypropyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, etc., isopropyltriisostearoyl titanate, isopropyltris ( Dioctylpyrophosphate) Titanium coupling agent treatment with titanate, metal soap treatment, amino acid treatment with acylglutamic acid, etc., lecithin treatment with hydrocarbon egg yolk lecithin, collagen treatment, polyethylene treatment, moisturizing treatment, inorganic compound treatment, mechanochemical treatment Etc. can be mentioned.

Examples of the fragrance include natural fragrances such as lavender oil, peppermint oil and lime oil, and synthetic fragrances such as ethylphenyl acetate, geraniol and p-tert-butylcyclohexyl acetate. Examples of the preservative / bactericidal agent include methylparaben, ethylparaben, propylparaben, benzalkonium, benzethonium and the like.
Examples of the antioxidant include dibutylhydroxytoluene, butylhydroxyanisole, propyl gallate, tocopherol and the like. Examples of the ultraviolet absorber include inorganic absorbents such as fine particle titanium oxide, fine particle zinc oxide, fine particle cerium oxide, fine particle iron oxide, and fine particle zirconium oxide, benzoic acid, paraaminobenzoic acid, anthranic acid, and salicylic acid. , Ceramic acid-based, benzophenone-based, dibenzoylmethane-based, and other organic absorbents.

Special compounding ingredients include hormones such as estradiol, estrone, ethynyl estradiol, cortisone, hydrocortisone, and prednison, vitamins such as vitamin A, vitamin B, vitamin C, and vitamin E, citric acid, tartrate acid, lactic acid, aluminum chloride, and sulfuric acid. Skin astringents such as aluminum / potassium, allantoinchlorohydroxyaluminum, zinc paraphenolsulfonate, zinc sulfate, cantalis tincture, capsicum tincture, ginger tincture, senburi extract, garlic extract, hinokithiol, carpronium chloride, pentadecanoic acid glyceride, vitamins Examples thereof include hair growth promoters such as E, estrogen and photosensitizer, and whitening agents such as -L-ascorbic acid magnesium phosphate and citric acid.

(3) Light-diffusing film The light-diffusing film includes plastic sheets such as glass, polycarbonate, acrylic resin, PET, and triacetyl cellulose (TAC), base materials such as plastic films, plastic lenses, and plastic panels, cathode line tubes, and fluorescent display tubes. , A light diffusing layer made of the above light diffusing composition is formed on the surface of a base material such as a liquid crystal display board. Although it depends on the application, the coating film is 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 fine particle film, or a conductive metal oxide fine particle. It is formed in combination with a membrane or other primer membrane used as needed. When used in combination, the light diffusion layer does not necessarily have to be formed on the outermost surface.

Hereinafter, the present invention will be specifically described with reference to Examples, but the present invention is not limited thereto. First, the measurement method in the examples will be described.
(Volume average particle size)
The volume average particle diameter of the hollow particles ^{was measured by a Coulter Multisizer TM} 3 (a measuring device manufactured by Beckman Coulter). Measurements were performed using apertures calibrated according to ^{the Multisizer TM} 3 User's Manual published by Beckman Coulter.
When selecting the aperture to be used for measurement, if 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 it is larger and 30 μm or less, select an aperture with a size of 100 μm, and if the particle size is larger than 30 μm and 90 μm or less, select an aperture with a size of 280 μm, and the assumed volume average of the particles. When the particle size was larger than 90 μm and 150 μm or less, an aperture having a size of 400 μm was selected as appropriate. If the volume average particle size after the measurement was different from the assumed volume average particle size, the aperture was changed to an appropriate size and the measurement was performed again.

Also, when an aperture with a size of 50 μm is selected, the Current (aperture current) is set to -800, and the Gain (gain) is set to 4, and when an aperture with a size of 100 μm is selected, the Current (aperture current) is-. 1600, Gain was set to 2, and when apertures with sizes of 280 μm and 400 μm were selected, Current (appearance current) was set to -3200 and Gain was set to 1.
As a sample for measurement, 0.1 g of particles were placed in 10 ml of a 0.1 wt% nonionic surfactant aqueous solution in a touch mixer (manufactured by Yamato Scientific Co., Ltd., “TOUCHMIXER MT-31”) and an ultrasonic cleaner (Vervocreer). , "ULTRASONIC CLEANER VS-150") was used to disperse and use a dispersion. During the measurement, the inside of the beaker was gently stirred so that no air bubbles entered, and the measurement was completed when 100,000 particles were measured. The volume average particle size of the particles was taken as the arithmetic mean in the volume-based particle size distribution of 100,000 particles.

(Morphological observation)
A conductive tape was attached to the sample table, and the particles were mounted on it. The particles were coated using an "Auto Fine Coater JFC-1300" sputtering device manufactured by JEOL Ltd. The particles were then photographed using a secondary electron detector of a "SU1510" scanning electron microscope manufactured by Hitachi High-Technologies Corporation.

(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. Then, the cured product was cut with nippers, the cross-sectional portion was smoothed with a cutter, and the sample was coated with an "Autofine Coater JFC-1300" sputtering device manufactured by JEOL Ltd. Next, the sample was photographed using a secondary electron detector of a "SU1510" scanning electron microscope manufactured by Hitachi High-Technologies Corporation.

(Average width of multiple protrusions)
Protrusions generated from the shell using the length measurement function attached to the "SU1510" scanning electron microscope manufactured by Hitachi High-Technologies Corporation on the images taken at 3000x and / or 5000x magnification during the above cross-sectional observation. Was measured. The length was measured for 30 arbitrary protrusions, and the arithmetic mean value was taken as the average width of the protrusions.

(Viscosity of oil phase)
The viscosity of the oil phase whose temperature was adjusted in a constant temperature bath at 25 ° C. was measured using a tuning fork type vibration viscometer SV-10 (manufactured by A & D Co., Ltd.). The viscosity of the mixture (unit: mPa · s) was determined by dividing the viscosity display value (unit: mPa · s × g / cm ^{3) on the apparatus by the density of the oil phase.} The density of the oil phase was determined by adding the above oil phase to a 25 mL pycnometer and dividing the weight (g) of the added oil phase by the volume (mL) of the pycnometer.

(Example 1: Hollow particles having an internal structure in which a plurality of protrusions are connected)
Methyl methacrylate (MMA) 100 g as a vinyl-based monofunctional monomer, ethylene glycol dimethacrylate (EGDMA) 100 g as a vinyl-based crosslinkable monomer, cyclohexane (CH) 150 g as a non-reactive solvent, and ethyl acetate (EA). 50 g, 2,2'-azobis (2,4-dimethylvaleronitrile) 2 g (manufactured by Fuji Film Wako Pure Chemical Industries, Ltd .; product name V-65) as a polymerization initiator, 0.16 g of lauryl phosphate as a dispersion aid Was mixed and dissolved to adjust the mixture (oil phase) (viscosity 0.69 mPa · s) (monomer: solvent = 50:50, MMA: EGDMA = 50:50, CH: EA = 75: 25). .. Further, 1200 g of ion-exchanged water as an aqueous medium and 24 g of magnesium pyrophosphate as a suspension stabilizer were mixed to prepare an aqueous medium (aqueous phase).
The above oil phase was added to this aqueous phase, and emulsification / dispersion treatment was carried out at 5500 rpm for 5 minutes using a polytron homogenizer PT10-35 (manufactured by Central Scientific Trading Co., Ltd.). The obtained emulsion was put into a 2 L pressure vessel with a stirring blade, and the stirring blade was heated at 50 ° C. for 4 hours while stirring at 250 rpm to allow the polymerization to proceed. Then, the reaction system was cooled to room temperature, and magnesium pyrophosphate, which is a suspension stabilizer, was decomposed with hydrochloric acid. The solid content was separated by dehydration by filtration, purified by repeating washing with water, and then dried at 100 ° C. to obtain hollow particles.
The surface photograph (3000 times) and the cross-sectional photograph (3000 times and 1000 times) of the obtained hollow particles are shown in FIG. It was confirmed that the hollow particles had a plurality of protrusions on the inner wall of the shell, and the plurality of protrusions on the inner wall of the shell had a structure in which they were connected to each other. The volume average particle size was 13.1 μm. The average width of the protrusions was 0.75 μm and the W / V was 0.057.

(Example 2: Hollow particles having an internal structure more complicatedly connected than in Example 1)
Hollow particles were obtained in the same manner as in Example 1 except that 140 g of cyclohexane and 60 g of ethyl acetate were used as the non-reactive solvent (monomer: solvent = 50:50, MMA: EGDMA = 50:50). , CH: EA = 70: 30, oil phase viscosity 0.68 mPa · s). The surface photograph (3000 times) and the cross-sectional photograph (3000 times and 1000 times) of the obtained hollow particles are shown in FIG. It was confirmed that the hollow particles had a plurality of protrusions on the inner wall of the shell, and the plurality of protrusions on the inner wall of the shell had a structure in which they were connected to each other. The volume average particle size was 9.7 μm. The average width of the protrusions was 0.49 μm and the W / V was 0.051.

(Example 3: Change in crosslinkable monomer ratio, hollow particles having an internal structure in which a plurality of protrusions are connected)
Hollow particles were prepared in the same manner as in Example 1 except that 90 g of methyl methacrylate (MMA) was used as the vinyl-based monofunctional monomer and 110 g of ethylene glycol dimethacrylate (EGDMA) was used as the vinyl-based crosslinkable monomer. Obtained (monomer: solvent = 50:50, MMA: EGDMA = 45:55, CH: EA = 75:25, oil phase viscosity 0.68 mPa · s). The surface photograph (3000 times) and the cross-sectional photograph (3000 times and 1000 times) of the obtained hollow particles are shown in FIG. It was confirmed that the hollow particles had a plurality of protrusions on the inner wall of the shell, and the plurality of protrusions on the inner wall of the shell had a structure in which they were connected to each other. The volume average particle size was 9.8 μm. The average width of the protrusions was 0.68 μm and the W / V was 0.070.

(Example 4: Change the crosslinkable monomer ratio, hollow particles having an internal structure more complicated than in Example 3)
Hollow particles were obtained in the same manner as in Example 3 except that 140 g of cyclohexane and 60 g of ethyl acetate were used as the non-reactive solvent (monomer: solvent = 50:50, MMA: EGDMA = 45:55). , CH: EA = 70: 30, oil phase viscosity 0.68 mPa · s). The surface photograph (3000 times) and the cross-sectional photograph (3000 times and 1000 times) of the obtained hollow particles are shown in FIG. It was confirmed that the hollow particles had a plurality of protrusions on the inner wall of the shell, and the plurality of protrusions on the inner wall of the shell had a structure in which they were connected to each other. The volume average particle size was 9.9 μm. The average width of the protrusions was 0.37 μm and the W / V was 0.037.

(Example 5: Change of dispersion aid)
Hollow particles were obtained in the same manner as in Example 3 except that lauryl phosphoric acid as a dispersion aid was changed to 0.40 g of "KAYAMER® PM-21" (manufactured by Nippon Kayaku Co., Ltd.). Particle: Solvent = 50:50, MMA: EGDMA = 45:55, CH: EA = 75:25, Oil phase viscosity 0.68 mPa · s). The surface photograph (3000 times) and the cross-sectional photograph (3000 times and 1000 times) of the obtained hollow particles are shown in FIG. It was confirmed that the hollow particles had a plurality of protrusions on the inner wall of the shell, and the plurality of protrusions on the inner wall of the shell had a structure in which they were connected to each other. The volume average particle size was 10.2 μm. The average width of the protrusions was 0.86 μm and the W / V was 0.084.

(Example 6: Using a single solvent)
108 g of methyl methacrylate (MMA) as a vinyl-based monofunctional monomer, 132 g of ethylene glycol dimethacrylate (EGDMA) as a vinyl-based crosslinkable monomer, and 2,2'-azobis (2,4-) as an initiator. Hollow particles were obtained in the same manner as in Example 1 except that 2.4 g of dimethyl balleronitrile (2.4 g) and 160 g of cyclohexane as a non-reactive solvent were used and ethyl acetate was not used (monomer: solvent). = 60: 40, MMA: EGDMA = 45: 55, cyclohexane alone used, oil phase viscosity 0.68 mPa · s). The surface photograph (3000 times) and the cross-sectional photograph (3000 times and 1000 times) of the obtained hollow particles are shown in FIG. It was confirmed that the hollow particles had a plurality of protrusions on the inner wall of the shell, and the plurality of protrusions on the inner wall of the shell had a structure in which they were connected to each other. The volume average particle size was 9.9 μm. The average width of the protrusions was 1.11 μm and the W / V was 0.112.

(Example 7: Use of a single solvent, hollow particles having an internal structure more complicatedly connected than in Example 6)
112.5 g of methyl methacrylate (MMA) as a vinyl-based monofunctional monomer, 137.5 g of ethylene glycol dimethacrylate (EGDMA) as a vinyl-based crosslinkable monomer, and 2,2'-azobis as an initiator. Hollow particles were obtained in the same manner as in Example 1 except that 2.5 g of 2,4-dimethylvaleronitrile and 150 g of cyclohexane as a non-reactive solvent were used and ethyl acetate was not used. Monomer: Solvent = 62:38, MMA: EGDMA = 45:55, cyclohexane alone used, oil phase viscosity 0.67 mPa · s). The surface photograph (3000 times) and the cross-sectional photograph (3000 times and 1000 times) of the obtained hollow particles are shown in FIG. It was confirmed that the hollow particles had a plurality of protrusions on the inner wall of the shell, and the plurality of protrusions on the inner wall of the shell had a structure in which they were connected to each other. The volume average particle size was 11.4 μm. The average width of the protrusions was 0.61 μm and the W / V was 0.054.

(Example 8: Change of dispersion aid)
Hollow particles were obtained in the same manner as in Example 7 except that the amount of lauryl phosphoric acid as a dispersion aid was 0.40 g of "KAYAMER (registered trademark) PM-21" (manufactured by Nippon Kayaku Co., Ltd.). Body: solvent = 65:35, MMA: EGDMA = 45:55, CH / EA = 100/0, oil phase viscosity 0.67 mPa · s). The surface photograph (3000 times) and the cross-sectional photograph (3000 times and 1000 times) of the obtained hollow particles are shown in FIG. It was confirmed that the hollow particles had a plurality of protrusions on the inner wall of the shell, and the plurality of protrusions on the inner wall of the shell had a structure in which they were connected to each other. The volume average particle size was 11.5 μm. The average width of the protrusions was 0.76 μm and the W / V was 0.066.

(Example 9: Thickener used, single solvent used)
Use 90 g of methyl methacrylate (MMA) as a vinyl-based monofunctional monomer, 110 g of ethylene glycol dimethacrylate (EGDMA) as a vinyl-based crosslinkable monomer, and 200 g of cyclohexane as a non-reactive solvent, and use ethyl acetate. Hollow particles were obtained in the same manner as in Example 1 except that 16 g of hydrophobic fumed silica R972 (EVONIK) was added as a thickener without using the mixture (monomer: solvent = 50:50, MMA). : EGDMA = 45: 55, cyclohexane alone used). The viscosity of the oil phase was 1.73 mPa · s. The surface photograph (3000 times) and the cross-sectional photograph (3000 times and 1000 times) of the obtained hollow particles are shown in FIG. It was confirmed that the hollow particles had a plurality of protrusions on the inner wall of the shell, and the plurality of protrusions on the inner wall of the shell had a structure in which they were connected to each other. The volume average particle size was 11.7 μm. The average width of the protrusions was 0.58 μm and the W / V was 0.050.

(Comparative example 1: Internal structure without protrusions, simple hollow particles)
DVB-810 (Nippon Steel Chemical Co., Ltd., divinylbenzene mixture) as a mixture of vinyl-based monofunctional monomer and vinyl-based crosslinkable monomer (100 g), hexadecane as a non-reactive solvent, 100 g, as a polymerization initiator A mixture (oil phase) was prepared by mixing and dissolving 2 g of benzoyl peroxide (BPO). (Monomer: solvent = 50:50) Further, 590 g of ion-exchanged water as an aqueous medium and 10 g of polyvinyl alcohol (manufactured by Nippon Synthetic Chemical Co., Ltd .; product name Gosenol GL-05) as a suspension stabilizer are mixed. , The aqueous medium (aqueous phase) was adjusted.
The above oil phase was added to this aqueous phase, and emulsification / dispersion treatment was carried out at 6000 rpm for 5 minutes using a polytron homogenizer PT10-35 (manufactured by Central Scientific Trading Co., Ltd.). The obtained emulsion was put into a glass container with a stirring blade of 1 L, and the polymerization was allowed to proceed by heating the stirring blade at 70 ° C. for 24 hours while stirring the stirring blade at 100 rpm in a nitrogen atmosphere. Then, the reaction system is cooled to room temperature, the obtained dispersion is dehydrated by filtration to separate solids, and repeated washing with water to remove polyvinyl alcohol as a suspension stabilizer, and then washing with ethanol. Hexadecane as a non-reactive solvent was removed by repeating. Then, it was dried at 100 degreeC to obtain hollow particles. A surface photograph (3000 times) and a cross-sectional photograph (3000 times and 1000 times) of the obtained particles are shown in FIG. It was confirmed that many hollow particles were smooth without protrusions on the inner wall of the shell and were simple hollow particles. The volume average particle size was 14.5 μm. In addition, in this specification, smoothing means the case where W / V is less than 0.01.

(Comparative Example 2: Porous shell, porous particles)
Particles were obtained in the same manner as in Example 1 except that cyclohexane as a non-reactive solvent was not used and 200 g of ethyl acetate was used (monomer: solvent = 50:50, MMA: EGDMA = 50: 50, Ethyl acetate alone used, oil phase viscosity 0.65 mPa · s). A surface photograph (3000 times) and a cross-sectional photograph (3000 times) of the obtained particles are shown in FIG. It was confirmed that the hollow particles did not have a clear shell and were porous particles. The volume average particle size was 10.2 μm.

(Comparative Example 3: Hollow particles having an internal structure more complicatedly connected than in Example 2)
100 g of methyl methacrylate (MMA) as a vinyl-based monofunctional monomer, 100 g of ethylene glycol dimethacrylate (EGDMA) as a vinyl-based crosslinkable monomer, 120 g of cyclohexane as a non-reactive solvent, and 80 g of ethyl acetate are used. Particles were obtained in the same manner as in Example 1 (monomer: solvent = 50:50, MMA: EGDMA = 50:50, CH: EA = 60: 40, oil phase viscosity 0.68 mPa).・ S). FIG. 3 shows a cross-sectional photograph of the obtained particle surface photograph (3000 times) and a cross-sectional photograph (3000 times). It was confirmed that the hollow particles had a plurality of protrusions on the inner wall of the shell, and the plurality of protrusions on the inner wall of the shell had a structure in which they were connected to each other. The volume average particle size was 12.1 μm. The average width of the protrusions was 0.23 μm and the W / V was 0.019.
Table 1 summarizes the raw materials for producing particles of the above Examples and Comparative Examples and their amounts (g).

(Evaluation of reflection characteristics of ultraviolet-visible near-infrared light)
To 10 g of a commercially available water-based paint (trade name manufactured by Asahipen Corporation; water-based versatile color clear), 2.5 g of particles obtained from Examples and Comparative Examples were added, and a planetary stirring defoamer (KURABO, Mazerustar KK) was added. A paint for evaluation was prepared by defoaming and stirring using −250).
The evaluation paint was applied to the black side of the concealment rate test paper with 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 point order.
An ultraviolet visible near infrared spectrophotometer (UV-3600Plus) manufactured by Shimadzu Corporation is used as a reflectance measuring device, and the reflection characteristics of ultraviolet light to near infrared light (wavelength 300 to 2500 nm) on the coated surface of the sample plate. Was measured as the reflectance (%). The measurement was carried out using a 60 mmΦ integrating sphere and barium sulfate as a standard white plate.
The above measurement was performed on the particles of Examples and Comparative Examples. The obtained results are shown in FIG. Further, the case where no particles are added is also shown in FIG. Further, Table 2 shows the reflectance at a wavelength of 1500 nm.

From FIG. 4 and Table 2, it can be seen that the hollow particles of the example have higher reflectance than the particles of the comparative example 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 region of 500 to 2500 nm. From this, it can be confirmed that the hollow particles of the example have a property of reflecting visible light and near-infrared light, and impart high visible light to near-infrared light reflection performance to the coating material.
Further, it can be confirmed that the hollow particles of the example impart high visible light to near-infrared light reflection performance to the paint as compared with the porous particles having no shell of Comparative Example 2.
Further, in the particles of the example, W / V calculated from the average width (W) of the plurality of protrusions on the inner wall of the shell and the volume average particle diameter (V) of the hollow particles was less than 0.02 in Comparative Example 3. It can be confirmed that the paint is given higher visible light to near-infrared light reflection performance than the particles.

(Paint Composition Production Example 1)
2 parts by weight of the hollow particles obtained in Example 1 and 20 parts by weight of a commercially available acrylic water-based glossy paint (manufactured by Campe Papio, trade name: Super Hit) were used for 3 minutes using a stirring defoaming device. A coating composition was obtained by mixing and defoaming for 1 minute.
The obtained coating composition was applied onto an ABS resin (acrylonitrile-butadiene-styrene resin) plate using a coating device set with a blade having a clearance of 75 μm, and then dried to obtain a coating film.

(Light Diffusing Composition and Light Diffusing Film Production Example 1)
7.5 parts by weight of the hollow particles obtained in Example 1, 30 parts by weight of acrylic resin (manufactured by DIC, product name Acrydic A811), 10 parts by weight of a cross-linking agent (manufactured by DIC, product name VM-D), A light diffusible composition was obtained by mixing 50 parts by weight of butyl acetate as a solvent with a stirring defoaming device for 3 minutes and defoaming for 1 minute.
The obtained light diffusing composition is applied onto a PET film having a thickness of 125 μm using a coating device set with a blade having a clearance of 50 μm, and then dried at 70 ° C. for 10 minutes to obtain a light diffusing film. It was.

(Example of prescription of cosmetics)
(Formulation Example 1)
Production / Blending Amount of Powder Foundation Hollow 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 Talk 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 Preservative Appropriate amount Fragrance Appropriate amount / Manufacturing method Hollow particles, red iron oxide , Yellow iron oxide, black iron oxide, titanium oxide, mica, and talc are mixed with a Henschel mixer, and liquid paraffin, octyldodecyl myristate, vaseline, and a preservative are added and dissolved, and the mixture is uniformly mixed. After adding a fragrance to this and mixing, it is crushed and passed through a sieve. This is compression molded into a gold plate to obtain a powder foundation.

(Formulation Example 2)
Production / Blending Amount of Cosmetic Emulsion Hollow particles obtained in Example 1 10.0 parts by weight Stearic acid 2.5 parts by weight Cetyl alcohol 1.5 parts by weight Vaseline 5.0 parts by weight Liquid paraffin 10.0 parts by weight Polyethylene ( 10 mol) Monooleic acid ester 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 Perfume 0.5 parts by weight Preservative Appropriate amount / manufacturing method First, stearic acid Acid, cetyl alcohol, vaseline, liquid paraffin, and polyethylene monooleic acid ester are heated and dissolved, hollow particles are added and mixed there, and the temperature 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). An oil phase is added to the aqueous phase, pre-emulsified, and then uniformly emulsified with a homogenizer. After emulsification, the mixture is cooled to 30 ° C. with stirring to obtain a cosmetic emulsion.

Claims (6)

The shell comprises a non-porous shell and an airspace partitioned by the shell, the shell having a plurality of protrusions on its inner wall, and the plurality of protrusions are hollow particles connected to each other.
The hollow particles are characterized by having a W / V of 0.02 to 0.5 (W means the average width of a plurality of protrusions, and V means the volume average particle diameter of the hollow particles). particle. The hollow particle according to claim 1, wherein the hollow particle has a volume average particle diameter of 1.0 to 50 μm, and the shell is made of a crosslinked resin. The crosslinked resin is derived from a vinyl-based monofunctional monomer and a vinyl-based crosslinkable monomer, and the vinyl-based monofunctional monomer and the vinyl-based crosslinkable monomer are (meth) acrylic acid esters. The hollow particle according to claim 2. The hollow particle according to any one of claims 1 to 3, wherein the hollow particle has a property of reflecting visible light and near infrared light. Any one of claims 1 to 4, wherein the hollow particles are used in applications selected from paint compositions, cosmetics, paper coating compositions, heat insulating compositions, light diffusing compositions and light diffusing films. The hollow particles described in. The method for producing hollow particles according to any one of claims 1 to 5.
A mixture containing a vinyl-based monofunctional monomer, a vinyl-based crosslinkable monomer, a non-reactive solvent, and a polymerization initiator is mixed in an aqueous medium containing a suspension stabilizer in the presence of a dispersion aid. A method for producing hollow particles, which comprises a step of polymerizing.