JP7372085B2 - Pigment-containing hollow particles and method for producing the same - Google Patents

Description

The present invention relates to pigment-containing 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 containing a pigment, and a method for producing the same. The pigment-containing hollow particles of the present invention are suitable for applications such as coating compositions, cosmetics, paper coating compositions, heat-insulating compositions, light-diffusing compositions, and light-diffusing films.

BACKGROUND ART Polymer particles (hollow particles) having air spaces inside are used in an extremely wide range of fields for the purpose of reducing the weight of materials, forming pores, and imparting heat insulation properties, sound insulation properties, impact resistance, etc.
These hollow particles are known to cause visible light scattering due to the difference in refractive index between the shell and the air space defined by the shell, and have better light scattering than polymer particles (solid particles) that have no internal air space. It has diffusibility. Because of this, 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 perspective of saving energy, the application of heat-shielding paints and heat-insulating paints to the roofs of buildings has been considered, and hollow-wall paints with excellent light scattering properties are being used as materials to improve heat-shielding and heat-insulating properties. The use of particles is being considered. For example, in International Publication No. 2017/150423 (Patent Document 1), a hollow particle having a porous structure inside the air space is proposed, and this hollow particle is said to have advanced light diffusion properties.

International Publication No. 2017/150423

BACKGROUND ART In recent years, from the perspective of saving energy, the application of heat-shielding paints and heat-insulating paints to the roofs of buildings has been considered, and there is a need for paints that improve heat-shielding and heat-insulating properties. In particular, paints in dark colors to black are in high demand for the roofs of outdoor buildings, automobiles, and the like.
The hollow particles described in Patent Document 1 have a high degree of whiteness due to their advanced light diffusion properties, and therefore are not suitable for addition to paints ranging from deep colors to black. Therefore, it has been desired to provide hollow particles suitable for addition to paints ranging from dark colors to black.

Thus, according to the present invention, there are provided pigment-containing hollow particles comprising a non-porous shell and an air space defined by the shell, and comprising pigment particles that do not substantially absorb near-infrared light, wherein the shell provides a pigment-containing hollow particle characterized in that it has a plurality of protrusions on its inner wall, and the plurality of protrusions are connected to each other.
Further, according to the present invention, there is a method for producing the pigment-containing hollow particles,
A mixture containing a vinyl monofunctional monomer, a vinyl crosslinkable monomer, a non-reactive solvent, a polymerization initiator, and pigment particles is added in the presence of a dispersion aid and a suspension stabilizer. A method for producing pigment-containing hollow particles is provided, which includes a step of polymerizing in an aqueous medium.

According to the present invention, pigment-containing hollow particles suitable for addition to paints of deep colors to black can be provided.
Further, in any of the following cases, pigment-containing hollow particles can be provided that are more suitable for addition to paints from dark colors to black.
(1) The pigment particles have a property that the reflectance of light with a wavelength of 400 to 700 nm is 10% or less, and the reflectance of light with a wavelength of 1200 to 1500 nm is 50% or more.
(2) Pigment particles are contained in the pigment-containing hollow particles in an amount of 1 to 30% by weight.
(3) The pigment-containing hollow particles have a volume average particle diameter of 1.0 to 50 μm, and the shell is composed of a crosslinked resin.
(4) The crosslinked resin is derived from a vinyl monofunctional monomer and a vinyl crosslinkable monomer, and the vinyl monofunctional monomer and the vinyl crosslinkable monomer are derived from (meth)acrylic acid. It's ester.
(5) The pigment-containing hollow particles are used in applications selected from paint compositions, cosmetics, paper coating compositions, heat-insulating compositions, light-diffusing compositions, and light-diffusing films.

1 is a cross-sectional photograph (3000 to 5000 times) of pigment-containing hollow particles of Examples 1 to 4. 3 is a cross-sectional photograph (3000 to 4000 times) of pigment-containing hollow particles of Example 5 and particles of Comparative Examples 1 and 5. It is a graph showing the light reflectance for each wavelength of each hollow particle of an example and a comparative example in reflection characteristic evaluation of ultraviolet-visible near-infrared light. It is a graph which shows the light reflectance with respect to each wavelength of the sample board containing each hollow particle of an Example and a comparative example in reflection characteristic evaluation of ultraviolet-visible near-infrared light.

(Pigment-containing hollow particles)
The pigment-containing hollow particles include a non-porous shell and an air space defined by the shell. The shell also has a plurality of protrusions on its inner wall. Furthermore, the plurality of protrusions are connected to each other. Furthermore, the pigment-containing hollow particles include pigment particles.

(1) Shell The material constituting the shell is not particularly limited as long as it can divide the air space. The material may include a crosslinked resin. The material may be free of inorganic components (eg, silica).
The type of crosslinked resin is not particularly limited as long as it can form the shell. Examples of the crosslinked resin include resins derived from vinyl monomers, and specifically, resins derived from vinyl monofunctional monomers and vinyl crosslinkable monomers. A vinyl monofunctional monomer is a monomer having one vinyl group, and a vinyl crosslinkable monomer is a monomer having two or more vinyl groups. The fact that the shell is made of a crosslinked resin can be confirmed, for example, by measuring the gel fraction.
Examples of vinyl monofunctional monomers 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 , i-propylstyrene, dimethylstyrene, bromostyrene, and other styrenic monomers. These monofunctional monomers can be used alone or in combination.

Examples of vinyl crosslinkable monomers include polyfunctional (meth)acrylic esters such as ethylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, 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 tetraallyloxyethane, and aromatic divinyl compounds such as divinylbenzene. It will be done. These crosslinking monomers can be used alone or in combination.
The vinyl monofunctional monomer and the vinyl crosslinkable monomer are preferably (meth)acrylic esters.

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

(2) Protrusions on the inner wall The shell has a plurality of protrusions on its 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 particle, and can also be in the range of 2 to 1,600. Further, the plurality of protrusions are connected to each other between adjacent protrusions. The fact that they are connected to each other can be confirmed by a cross-sectional photograph of the hollow particles.
The volume average particle diameter V may be 1.0 to 50 μm. Although it depends on the application, the volume average particle diameter is preferably 2.0 to 30 μm, more preferably 3.0 to 25 μm.
The average width W of the plurality of protrusions may 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 projections have a W/V of 0.02 to 0.5 with respect to the volume average particle diameter of the hollow particles (W means the average width of the plurality of projections, and V means the volume average particle diameter of the hollow particles. ) is preferable. When W/V is less than 0.02 or greater than 0.5, light diffusivity may become insufficient. W/V is more preferably from 0.025 to 0.4, even more preferably from 0.03 to 0.3.
The protrusion may be made of the same material as the shell.

(3) Pigment Particles Pigment particles are not particularly limited as long as they do not substantially absorb near-infrared light, and they can reflect and/or transmit near-infrared light, but those that reflect are preferable. Generally, near-infrared light means light with a wavelength of 800 to 2,500 nm, and visible light means light with a wavelength of 400 nm or more and less than 800 nm. With respect to the expression, near-infrared light means light with a wavelength of at least 800-1500 nm, such as 800-1500 nm, such as 800-1700 nm, such as 800-2000 nm, and also such as 800-2500 nm. Therefore, "not substantially absorbing near-infrared light" means that the reflectance of near-infrared light including light with a wavelength of at least 800 to 1500 nm is, for example, 40% or more, for example, 50% or more, or for example, 60% or more. and/or can mean transparent. Here, the reflectance is the reflectance of a sample when measured by an ultraviolet-visible near-infrared spectrophotometer using an integrating sphere and barium sulfate as a reference sample, as described in the examples, It refers to the average value in the above wavelength range.
Pigment particles of a color depending on the desired paint can be used as the pigment particles. In order to obtain a deep-colored to black paint, the pigment particles are also preferably dark-colored to black particles. In particular, black pigment particles are preferred. Here, carbon black is known as black pigment particles. Carbon black is known to absorb near-infrared light, and as a result of this absorption, it becomes difficult to improve heat shielding properties and heat insulation properties. On the other hand, since the pigment particles used in the present invention do not substantially absorb near-infrared light, it is possible to improve heat shielding properties and heat insulation properties. In the present invention, it is preferable not to use carbon black.
Examples of pigment particles include anthraquinone pigments, quinacridone pigments, diketopyrrolopyrrole pigments, indigo/thioindigo pigments, perinone pigments, perylene pigments, phthalocyanine pigments, indoline pigments, isoindoline pigments, and isoindoline pigments. Examples include indolinone pigments, dioxazine pigments, quinophthalone pigments, nickel azo pigments, metal complex pigments, insoluble azo pigments, soluble azo pigments, high molecular weight azo pigments, azomethine azo black pigments, aniline black pigments, etc. . Among these, CAS No. 1 is an azomethine azo black pigment (azomethine pigment). 1-[4-[(4,5,6,7-tetrachloro-3-oxoisoindolin-1-ylidene)amino]phenylazo]-2-hydroxy-N-(4'-methoxy) of 103621-96-1 -2'-methylphenyl)-11H-benzo[a]carbazole-3-carboxamide is preferred. This azomethine pigment is available from Dainichiseika Co. as "Chromofine Black A1103".
Inorganic pigments can also be used as pigments that can reflect near-infrared light. Furthermore, by mixing two or more of red, orange, yellow, green, blue, and violet pigments, a mixture of dark to black pigments can be used.

The pigment particles preferably have a reflectance of 10% or less for light in the wavelength range of 400 to 700 nm, and a reflectance of 50% or more to light in the wavelength range of 1200 to 1500 nm. With this property, visible light is absorbed and the color changes from dark to black, making it suitable for addition to paints that change from dark to black, and by reflecting near-infrared light, it has heat shielding and heat insulation properties. We can provide improved paints. The reflectance of light with a wavelength of 400 to 700 nm is more preferably 5% or less. The pigment particles preferably have a property that the reflectance of light with a wavelength of 800 to 1500 nm is 50% or more, and a property that the reflectance of light with a wavelength of 800 to 2000 nm is 50% or more. It is more preferable to have a reflectance of 80% or more for light having a wavelength of 900 to 1500 nm, and even more preferable.
The pigment particles preferably have an average particle diameter of 10 to 5000 nm. Here, the average particle size can be measured by general measurement methods such as dynamic light scattering, laser diffraction/scattering, image analysis, and pore electrical resistance, or by observation using a scanning electron microscope. It is.
The pigment particles may be contained in the pigment-containing hollow particles in an amount of 1 to 30% by weight. When the content is less than 1% by weight, absorption of visible light may become insufficient and the effect of improving heat shielding properties and heat insulation properties may become insufficient. If it is more than 30% by weight, the strength of the hollow particles may decrease. The content is more preferably 3 to 25% by weight, and even more preferably 5 to 20% by weight.

(4) External shape, etc. The external shape of the pigment-containing hollow particles is not particularly limited, but it is preferably as close to a spherical shape as possible.
The shell has a thickness of 0.1-2.0 μm. If the thickness is less than 0.1 μm, the pigment-containing 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. Being non-porous allows the pigment-containing hollow particles to maintain air space even when they are used for various purposes, making it possible to exhibit the light diffusivity of the pigment-containing hollow particles. Non-porousness can be confirmed by, for example, whether a resin for fixing the pigment-containing hollow particles is present in the air space when taking a cross-sectional photograph of the pigment-containing hollow particles.
A particle mass composed of a plurality of particles connected to each other may exist within the airspace. Particle clusters of pigment-containing hollow particles may be connected to adjacent protrusions.
Further, the ratio (R500/R1500) of the reflectance of the pigment-containing hollow particles to light with a wavelength of 500 nm (R500) and reflectance of light with a wavelength of 1500 nm (R1500) is 0.01 to 0.5. is preferable, and more preferably 0.02 to 0.2. R1500 may be 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95%, 99%, 100%.

(Method for manufacturing pigment-containing hollow particles)
The method for producing pigment-containing hollow particles involves adding a mixture containing a vinyl monofunctional monomer, a vinyl crosslinking monomer, a non-reactive solvent, a dispersion aid, and pigment particles to a polymerization initiator. It includes a step of polymerizing in an aqueous medium containing a suspension stabilizer in the presence of a suspension stabilizer (polymerization step).

(1) Polymerization process In the polymerization process, the vinyl monofunctional monomer and the vinyl crosslinkable monomer polymerize at the interface between the mixture and the aqueous medium, and the resulting polymer collects at the interface with the aqueous medium. , pigment-containing hollow particles are obtained.
In the polymerization step, first, at least a vinyl monofunctional monomer, a vinyl crosslinkable monomer, a non-reactive solvent, a polymerization initiator, and pigment particles are mixed to obtain a mixture. Note that the amount of the monomer used and the content of the monomer-derived component constituting the outer shell are substantially the same.
Examples of non-reactive solvents 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, etc. Can be mentioned. These non-reactive organic solvents can be used alone or in combination. The boiling point of the non-reactive solvent is preferably less than 100° C., since it can be easily removed from the pigment-containing hollow particles.
The amount of the non-reactive solvent added is not particularly limited, but is 40 to 250 parts by weight based on 100 parts by weight of the total monomers. If the amount added is less than 40 parts by weight, the proportion of the air space partitioned by the shell will be small, resulting in insufficient light diffusivity. If it exceeds 250 parts by weight, shell formation may be insufficient and particles with sufficient physical strength may not be obtained.

Polymerization of monomers is carried out in the presence of a polymerization initiator. The polymerization initiator is not particularly limited, and includes, for example, persulfates such as ammonium persulfate, potassium persulfate, and sodium persulfate;
Cumene hydroperoxide, di-tert-butyl peroxide, dicumyl peroxide, benzoyl peroxide, lauroyl peroxide, dimethylbis(tert-butylperoxy)hexane, dimethylbis(tert-butylperoxy)hexine-3, Bis(tert-butylperoxyisopropyl)benzene, bis(tert-butylperoxy)trimethylcyclohexane, butyl-bis(tert-butylperoxy)valerate, tert-butyl 2-ethylhexane peroxyate, dibenzoyl peroxide, para Organic peroxides such as menthane hydroperoxide and tert-butyl peroxybenzoate,
2,2'-azobis[2-(2-imidazolin-2-yl)propane] dihydrochloride, 2,2'-azobis[2-(2-imidazolin-2-yl)propane] disulfate dihydrate 2,2'-azobis(2-amidinopropane) dihydrochloride, 2,2'-azobis[N-(2-carboxyethyl)-2-methylpropionamidine] 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- 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-methylpropionamide), dimethyl-2,2'-azobisisobutyrate, dimethyl-2,2'-azobis(2-methylpropinate), 2-(carbamoylazo)isobutyronitrile, 4,4'-azobis( Examples include azo compounds such as 4-cyanovaleric acid). These polymerization initiators can be used alone or in combination.
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 total monomers.
Next, the monomers in the dispersed mixture are subjected to polymerization to obtain pigment-containing hollow particles. Polymerization is not particularly limited, and is carried out while appropriately adjusting various conditions such as polymerization temperature and polymerization time depending on the types of monomers and polymerization initiators 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.
A thickener 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 inorganic thickeners 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 suspension stabilizers.
Examples of the aqueous medium constituting the aqueous medium include water, a mixture of water and a water-soluble organic solvent (eg, lower alcohol such as methanol and ethanol), and the like.
Suspension stabilizers include, for example, phosphates such as calcium phosphate, magnesium phosphate, aluminum phosphate, zinc phosphate, pyrophosphates such as calcium pyrophosphate, magnesium pyrophosphate, aluminum pyrophosphate, zinc pyrophosphate, and calcium carbonate. Examples include poorly water-soluble inorganic compounds such as magnesium carbonate, calcium hydroxide, magnesium hydroxide, aluminum hydroxide, calcium metasilicate, calcium sulfate, barium sulfate, and colloidal silica. 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 total monomers and non-reactive solvent. If the amount used is less than 0.5 part by weight, the mixture may not be sufficiently dispersed. If the amount used is more than 10 parts by weight, it is not preferable because the effect commensurate with the amount used cannot be obtained and it is uneconomical in terms of cost.

Polymerization is carried out in the presence of dispersion aids. The dispersion aid may be present in the mixture or in the aqueous medium.
Examples of dispersion aids include lauryl phosphoric acid, polyoxyethylene (1) lauryl ether phosphoric acid, dipolyoxyethylene (2) alkyl ether phosphoric acid, dipolyoxyethylene (4) alkyl ether phosphoric acid, and dipolyoxyethylene (4) alkyl ether phosphoric acid. 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 0.001 to 0.5 parts by weight based on 100 parts by weight of the mixture of all monomers and non-reactive solvent. If the amount added is less than 0.001 parts by weight, the mixture may not be sufficiently dispersed. If it exceeds 0.5 part by weight, a shell may not be formed.
The inventors believe that the uniquely shaped pigment-containing hollow particles of the present invention can be appropriately manufactured by controlling the interfacial tension acting on the interface between a mixture (oil phase) and an aqueous medium (aqueous phase). ing. For example, when interfacial tension is high, the number of protrusions tends to decrease and/or the protrusions tend to increase in size. Furthermore, 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 determined by, for example, the type of non-reactive solvent used, the ratio of total monomers to non-reactive solvent, the amount of dispersant, and the amount of dispersion aid. It can be controlled by adjusting.
In addition, the inventors believe that the uniquely shaped hollow particles of the present invention can be appropriately manufactured 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 protrusions tend to increase in size. For example, even when the interfacial tension is high, hollow particles with a large number of protrusions and/or small protrusions may be obtained by increasing the viscosity of the mixture (oil phase).
The pigments used may also function as thickening agents.
The mixture is dispersed in an aqueous medium while adjusting various conditions such as stirring speed and stirring time as appropriate so as to obtain pigment-containing hollow particles having a desired particle size.
(2) Other steps Pigment-containing hollow particles can be removed from the aqueous medium by centrifugation, water washing, and drying, if necessary.

(Application)
Pigment-containing hollow particles can be used in applications such as coating compositions, cosmetics, paper coating compositions, heat-insulating compositions, light-diffusing compositions, and light-diffusing films. In particular, it is suitable for use in applications requiring improved heat shielding and heat insulation properties. In addition, it is suitable for use in applications where it is desired to have a dark to black color.

(1) Paint, heat-insulating and light-diffusing compositions These compositions contain binder resins, UV curable resins, solvents, etc., as necessary. As the binder resin, an organic solvent or water-soluble resin, or an emulsion-type aqueous resin that can be dispersed in water can be used.
The amounts of the binder resin or UV curable resin and hollow particles added also vary depending on the thickness of the coating film to be formed, the average particle diameter of the hollow particles, and the coating method. The amount of binder resin added is preferably 5 to 50% by weight based on the total of binder resin (solid content when an emulsion type aqueous resin is used) and hollow particles. A more preferable content is 10 to 50% by weight, and an even more preferable content is 20 to 40% by weight.
Examples of binder resins include acrylic resins, alkyd resins, polyester resins, polyurethane resins, chlorinated polyolefin resins, and amorphous polyolefin resins, and examples of UV-curable resins include polyhydric alcohol polyfunctional (meth)acrylates and the like. Functional (meth)acrylate resins; examples include polyfunctional urethane acrylate resins synthesized from diisocyanates, polyhydric alcohols, (meth)acrylic esters having hydroxyl groups, and the like.

As the UV curable resin, a polyfunctional (meth)acrylate resin is preferred, and a polyhydric alcohol polyfunctional (meth)acrylate resin having three or more (meth)acryloyl groups in one molecule is more preferred. Specifically, the polyhydric alcohol polyfunctional (meth)acrylate resin having three or more (meth)acryloyl groups in one molecule includes trimethylolpropane tri(meth)acrylate, trimethylolethane tri(meth)acrylate , 1,2,4-cyclohexane tetra(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, tripentaerythritol hexaacrylate, and the like, and they may be used alone or in combination of two or more.

When using a UV curable resin, a photopolymerization initiator is usually used together. The photopolymerization initiator is not particularly limited.
Examples of photopolymerization initiators include acetophenones, benzoins, benzophenones, phosphine oxides, ketals, α-hydroxyalkylphenones, α-aminoalkylphenones, anthraquinones, thioxanthones, azo compounds, and peroxides. (described in JP-A No. 2001-139663, etc.), 2,3-dialkyldione compounds, disulfide compounds, fluoroamine compounds, aromatic sulfoniums, onium salts, borate salts, active halogen compounds, α-acyloxy Examples include muester and the like.
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 it 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 UV curable resin. For example, for 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, 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 may contain known paint surface conditioners, fluidity conditioners, ultraviolet absorbers, light stabilizers, curing catalysts, extender pigments, coloring pigments, metal pigments, mica powder pigments, dyes, etc., as necessary. 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, spray coating method, roll coating method, brush coating method, etc., and coating reverse roll coating method, gravure coating method, die coating method, comma coating method, spray coating method to coat a base material such as a film as a thin layer. can be mentioned. The composition may be diluted to adjust the viscosity as necessary. Diluents include hydrocarbon solvents such as toluene and xylene; ketone solvents such as methyl ethyl ketone and methyl isobutyl ketone; ester solvents such as ethyl acetate and butyl acetate; ether solvents such as dioxane and ethylene glycol diethyl ether; water. ; Examples include alcohol solvents. These diluents may be used alone or in combination of two or more.
A coating film can be formed by coating on an arbitrary coating surface such as a base material, drying this coating film, and then curing the coating film as necessary. The coating film using the coating composition can be used by coating various substrates, including metals, wood, glass, plastics, etc., but is not particularly limited. Moreover, it can also be used by coating a transparent substrate such as polyethylene terephthalate (hereinafter abbreviated as PET), polyethylene carbonate (hereinafter abbreviated as PC), or acrylic.
(2) Cosmetic The cosmetic preferably contains pigment-containing hollow particles in a range of 1 to 40% by weight.
Cosmetics include soaps, body shampoos, facial cleansing creams, cleaning cosmetics such as facial scrubs, lotions, creams, milky lotions, packs, powders, foundations, lipsticks, lip balms, blushers, eyebrow cosmetics, manicure cosmetics, Hair washing cosmetics, hair dyes, hair styling products, aromatic cosmetics, toothpaste, bath additives, antiperspirants, sunscreen products, suntan products, body powders, baby powders and other body cosmetics, shaving creams, pre-shave lotions, Examples include lotions such as aftershave lotion and body lotion.

In addition, ingredients commonly used in cosmetics can be added depending on the purpose, as long as the effects of the present invention are not impaired. Such ingredients include, for example, water, lower alcohols, oils and waxes, hydrocarbons, higher fatty acids, higher alcohols, sterols, fatty acid esters, metal soaps, humectants, surfactants, polymer compounds, color material raw materials, Examples include fragrances, preservatives/sterilizers, antioxidants, ultraviolet absorbers, and specially formulated ingredients.
Fats and waxes include avocado oil, almond oil, olive oil, cacao butter, beef tallow, sesame fat, wheat germ oil, safflower oil, shea butter, turtle oil, camellia oil, persic oil, castor oil, grape oil, macadamia nut oil, Mink oil, egg yolk oil, Japanese wax, coconut oil, rosehip oil, hydrogenated oil, silicone oil, orange roughy oil, carnauba wax, candelilla wax, spermaceti wax, jojoba oil, montan wax, beeswax, lanolin, and the like.
Examples of hydrocarbons include liquid paraffin, vaseline, paraffin, ceresin, 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 acids.

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, decyltetradeca Examples include Knoll and the like.
Examples of sterols include cholesterol, dihydrocholesterol, and phytocholesterol.
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, isooctanoic acid. Cetyl, decyl palmitate, glyceryl trimyristate, tri(caprylic/capric) glycerin, propylene glycol dioleate, glyceryl triisostearate, glyceryl triisooctoate, cetyl lactate, myristyl lactate, diisostearyl malate and cholesteryl isostearate. , 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, zinc undecylenate, and the like.
Examples of humectants include glycerin, propylene glycol, 1,3-butylene glycol, polyethylene glycol, sodium dl-pyrrolidonecarboxylate, sodium lactate, sorbitol, sodium hyaluronate, polyglycerin, xylit, maltitol, and the like.
Examples of surfactants include higher fatty acid soaps, higher alcohol sulfates, N-acyl glutamates, anionic surfactants such as phosphate ester salts, cationic surfactants such as amine salts and quaternary ammonium salts, and betaine. type, amino acid type, imidazoline type, amphoteric surfactants such as lecithin, nonionic surfactants such as fatty acid monoglycerides, propylene glycol fatty acid esters, sorbitan fatty acid esters, sucrose fatty acid esters, polyglycerin fatty acid esters, and ethylene oxide condensates. Can be mentioned.

Examples of polymer compounds include natural polymer compounds such as gum arabic, gum tragacanth, guar gum, locust bean gum, gum karaya, iris moss, quince seed, gelatin, shellac, rosin, casein, 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 , synthetic polymer compounds such as resin particles such as polymethyl methacrylate particles, crosslinked polystyrene particles, silicone particles, urethane particles, polyethylene particles, and silica particles.

Color material raw materials include iron oxide, ultramarine, konjou, 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 (calcined gypsum), calcium phosphate, hydroxyapatite, ceramic powder, azo type, nitro type, nitroso type, xanthene type , quinoline-based, anthraquinoline-based, indigo-based, triphenylmethane-based, phthalocyanine-based, and pyrene-based tar pigments.

Here, the powder raw materials such as the above-mentioned polymer compounds and color material raw materials may be subjected to surface treatment in advance. As the surface treatment method, conventionally known surface treatment techniques can be used. For example, oil treatment with hydrocarbon oil, ester oil, lanolin, etc., silicone treatment with dimethylpolysiloxane, methylhydrogenpolysiloxane, methylphenylpolysiloxane, etc., 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., 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 treatment with hydrogenated egg yolk lecithin, etc., collagen treatment, polyethylene treatment, moisture retention treatment, inorganic compound treatment, mechanochemical treatment Examples of processing methods include:

Examples of fragrances include natural fragrances such as lavender oil, peppermint oil, and lime oil, and synthetic fragrances such as ethyl phenylacetate, geraniol, and p-tert-butylcyclohexyl acetate. Examples of preservatives and disinfectants include methylparaben, ethylparaben, propylparaben, benzalkonium, and benzethonium.
Examples of the antioxidant include dibutylhydroxytoluene, butylhydroxyanisole, propyl gallate, tocopherol, and the like. Examples of ultraviolet absorbers include inorganic absorbers such as fine titanium oxide, fine zinc oxide, fine cerium oxide, fine iron oxide, and fine zirconium oxide, benzoic acid, para-aminobenzoic acid, anthranilic acid, and salicylic acid. , cinnamic acid-based, benzophenone-based, dibenzoylmethane-based, and other organic absorbents.

Specially formulated ingredients include hormones such as estradiol, estrone, ethinyl estradiol, cortisone, hydrocortisone, and prednisone, vitamins such as vitamin A, vitamin B, vitamin C, and vitamin E, citric acid, tartaric acid, lactic acid, aluminum chloride, and sulfuric acid. Skin astringents such as aluminum/potassium, allantoin chlorhydroxyaluminum, zinc paraphenolsulfonate, zinc sulfate, cantharis tincture, capsicum tincture, ginger tincture, Japanese cabbage extract, garlic extract, hinokitiol, carpronium chloride, pentadecanoic acid glyceride, vitamins Examples include hair growth promoters such as E, estrogen, photosensitizer, and whitening agents such as magnesium phosphate-L-ascorbate and kojic acid.

(3) Light diffusion film Light diffusion film is used for glass, polycarbonate, acrylic resin, PET, plastic sheets such as triacetyl cellulose (TAC), base materials such as plastic films, plastic lenses, and plastic panels, cathode ray tubes, and fluorescent display tubes. , a light-diffusing layer made of the above-mentioned light-diffusing composition is formed on the surface of a substrate such as a liquid crystal display board. Depending on the application, the coating may be used alone or on the base material as a protective film, hard coat film, flattening film, high refractive index film, insulating film, conductive resin film, conductive metal fine particle film, or conductive metal oxide fine particle. The film is formed in combination with a primer film, etc., which is used as necessary. Note that when used in combination, the light diffusion layer does not necessarily need to be formed on the outermost surface.

EXAMPLES Hereinafter, the present invention will be specifically explained with reference to Examples, but the present invention is not limited thereto. First, the measurement method in Examples will be explained.
(Volume average particle diameter)
The volume average particle diameter of the particles was measured using Coulter Multisizer ^TM 3 (measurement device manufactured by Beckman Coulter). Measurements were performed using an aperture calibrated according to the Multisizer ^™ 3 User's Manual published by Beckman Coulter.
In addition, when selecting the aperture 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, select an aperture with a size of 50 μm; If the particle's expected volume average particle diameter is greater than 30 μm and 90 μm or less, select an aperture with a size of 100 μm; When the particle diameter was greater than 90 μm and less than 150 μm, an aperture having a size of 400 μm was selected, etc. as appropriate. If the volume average particle diameter after measurement was different from the expected volume average particle diameter, the aperture was changed to an appropriate size and the measurement was performed again.

Also, if you select an aperture with a size of 50 μm, Current (aperture current) is set to -800 and Gain (gain) is set to 4, and if you select an aperture with a size of 100 μm, Current (aperture current) is set to -800. 1600, 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 was set to 1.
As a sample for measurement, 0.1 g of particles was placed in 10 ml of a 0.1% by weight nonionic surfactant aqueous solution using a touch mixer ("TOUCHMIXER MT-31" manufactured by Yamato Kagaku Co., Ltd.) and an ultrasonic cleaner (Vervo Crea Co., Ltd.). A dispersion liquid was used. During the measurement, the inside of the beaker was gently stirred to prevent air bubbles from entering, and the measurement was terminated when 100,000 particles were measured. The volume average particle diameter V of the particles was taken as the arithmetic mean of the volume-based particle size distribution of 100,000 particles.

(Cross-sectional observation)
After the washing step, the particles dried at 100° C. were mixed with photocurable resin D-800 (JEOL Ltd.) and irradiated with ultraviolet light to obtain a cured product. Thereafter, the cured product was cut with nippers, the cross section was smoothed using a cutter, and the sample was coated using a sputtering device "Auto Fine Coater JFC-1300" manufactured by JEOL. Next, the sample was photographed using a secondary electron detector of a "SU1510" scanning electron microscope manufactured by Hitachi High Technologies.

(Average width of multiple protrusions)
During the above cross-sectional observation, the length of the protrusion arising from the shell was measured using the length measurement function attached to the "SU1510" scanning electron microscope manufactured by Hitachi High-Technologies, Inc. I did it. The length was measured for 30 arbitrary protrusions, and the arithmetic mean value was taken as the average width W of the protrusions.

(Light reflectance of particles)
An ultraviolet-visible-near-infrared spectrophotometer (UV-3600Plus) manufactured by Shimadzu Corporation was used as a measuring device, and after the washing process, the particles were dried at 100°C, and the ultraviolet to near-infrared light (wavelength 300 to 2500 nm) was measured. Reflection properties were measured as reflectance (%). Note that the measurement was performed by filling each particle into a powder sample holder (for integrating sphere). In addition, the reflectance value of a barium sulfate standard white plate, which was measured using a 60 mmΦ integrating sphere and barium sulfate as the standard white plate, was defined as 100% reflectance. In addition, in the software accompanying the UV-visible near-infrared spectrophotometer (UV-3600Plus), the "S/R switching" function was set to "standard" and diffuse reflection measurements were performed.

(Example 1)
90 g of methyl methacrylate (MMA) as a vinyl monofunctional monomer, 110 g of ethylene glycol dimethacrylate (EGDMA) as a vinyl crosslinking monomer, 150 g of cyclohexane as a non-reactive solvent, and 50 g of ethyl acetate, polymerization initiator 2g of 2,2'-azobis(2,4-dimethylvaleronitrile) (manufactured by Fuji Film Wako Pure Chemical Industries, Ltd.; product name V-65), 0.16g of lauryl phosphoric acid as a dispersion aid, and 0.16g of lauryl phosphoric acid as a black pigment. A mixture (oil phase) was prepared by mixing and dissolving 20 g of Chromofine Black A1103 (manufactured by Dainichiseika Chemical Industry Co., Ltd.). 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 phase.
The above oil phase was added to this aqueous phase, and emulsification and dispersion treatment was performed 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 equipped with a stirring blade, and the mixture was heated at 50° C. for 4 hours while stirring with the stirring blade at 250 rpm to advance polymerization. Thereafter, the reaction system was cooled to room temperature, and the suspension stabilizer, magnesium pyrophosphate, was decomposed with hydrochloric acid. The solid content was separated by dehydration by filtration, purified by repeated washing with water, and then dried at 60°C to obtain pigment-containing hollow particles.
FIG. 1 shows a cross-sectional electron microscope (SEM) photograph (3000 times) of the obtained pigment-containing hollow particles. It was confirmed that it had an internal porous structure. The volume average particle diameter was 10.0 μm. As a result of evaluating the light reflection performance of visible light to near infrared rays of the obtained pigment-containing hollow particles, the value of R500/R1500 was 0.132.

(Example 2)
Pigment-containing hollow particles were obtained in the same manner as in Example 1, except that 40 g of Chromofine Black A1103 was used as the black pigment. A cross-sectional SEM photograph (3000x magnification) of the obtained pigment-containing hollow particles is shown in FIG. From FIG. 1, it was confirmed that it had an internal porous structure. The volume average particle diameter was 10.1 μm. As a result of evaluating the light reflection performance of visible light to near infrared rays of the obtained pigment-containing hollow particles, the value of R500/R1500 was 0.048.

(Example 3)
100 g of MMA as a monofunctional monomer, 100 g of EGDMA as a crosslinking monomer, 170 g of tetraorthosilicate (TEOS), 30 g of ethyl acetate as a non-reactive solvent, 2,2'-azobis(2, 4-dimethylvaleronitrile) 2.0 g (manufactured by Fuji Film Wako Pure Chemical Industries, Ltd.; product name V-65), (1R,2S,5R)-5-methyl-2-(propane-2- A polymerizable composition was prepared by mixing 1.0 g of cyclohexyl 4-methylbenzenesulfonate (manufactured by Fuji Film Wako Pure Chemical Industries, Ltd.; product name WPAG-699) and 12 g of Chromofine Black A1103 as a black pigment. On the other hand, 26 g of magnesium pyrophosphate and 0.16 g of lauryl phosphoric acid were added as suspension stabilizers to 1200 g of ion-exchanged water as an aqueous phase.
Emulsification and dispersion treatment was performed at 5500 rpm for 5 minutes using a Polytron homogenizer PT10-35. The obtained emulsion was put into a 2 L pressure vessel equipped with a stirring blade, and the mixture was heated at 50° C. for 4 hours while stirring with the stirring blade at 250 rpm to advance polymerization. The reaction temperature was raised to 105° C. while stirring, and the gelation reaction of TEOS was allowed to proceed by heating for 2 hours. Thereafter, the reaction system was cooled to room temperature to obtain an emulsion containing particles.
After adding hydrochloric acid to the obtained emulsion to dissolve magnesium pyrophosphate, particles were taken out from the emulsion by performing suction filtration. After repeated washing with water and purification, hollow particles containing pigment were obtained by drying in a vacuum oven at 60°C.
A cross-sectional SEM photograph (5000 times) of the obtained pigment-containing hollow particles is shown in FIG. From FIG. 1, it was confirmed that it had an internal porous structure. The volume average particle diameter was 11.7 μm. As a result of evaluating the light reflection performance of visible light to near infrared rays of the obtained pigment-containing hollow particles, the value of R500/R1500 was 0.129.

(Example 4)
Pigment-containing hollow particles were obtained in the same manner as in Example 3, except that 28 g of Chromofine Black A1103 was used as the black pigment. A cross-sectional SEM photograph (5000 times) of the obtained pigment-containing hollow particles is shown in FIG. A cross-sectional photograph of the obtained pigment-containing hollow particles is shown in FIG. It was confirmed that it had an internal porous structure. The volume average particle diameter was 12.1 μm. As a result of evaluating the light reflection performance of the obtained particles from visible light to near infrared rays, the value of R500/R1500 was 0.062.

(Example 5)
Pigment-containing hollow particles were obtained in the same manner as in Example 1, except that the black pigment was changed to 40 g of Black3601 (manufactured by Asahi Sangyo Co., Ltd.). A cross-sectional SEM photograph (3000x magnification) of the obtained pigment-containing hollow particles is shown in FIG. From FIG. 2, it was confirmed that it had an internal porous structure. The volume average particle diameter was 14.2 μm. From FIG. 4, as a result of evaluating the light reflection performance of visible light to near infrared rays of the obtained pigment-containing hollow particles, the value of R500/R1500 was 0.191.

(Comparative example 1)
25 g of MMA, 25 g of EGDMA, 40 g of TEOS, 10 g of toluene, 0.5 g of 2,2'-azobis(2,4-dimethylvaleronitrile), (1R,2S,5R)-5-methyl-2-( as a latent pH adjuster) A mixture was prepared by mixing and dissolving 1 g of cyclohexyl (propan-2-yl) 4-methylbenzenesulfonate. The resulting mixture was mixed with 300 ml (300 g) of an aqueous solution of polyvinyl alcohol (PVA) (manufactured by Nippon Gosei Kagaku Co., Ltd.; product name Gohsenol GH-17, polyvinyl alcohol 3 g) prepared to a concentration of 1% by weight. The obtained mixed solution was put into a 1 L beaker, and emulsification and dispersion treatment was performed for 3 minutes at a rotation speed of 4000 rpm using a Homomixer (manufactured by Primix Co., Ltd.; product name: Homomixer MK-II type 2.5). The obtained emulsion was poured into a 500 ml pressure vessel equipped with a stirring blade, and the particles were obtained by stirring at a temperature of 50°C for 8 hours and at 110°C for 2 hours while stirring the stirring blade at 200 rpm. . The obtained particles were removed from the emulsion by centrifugation and separation of the supernatant, repeatedly washed with water, purified, and then dried in a vacuum oven at 60°C.
A cross-sectional SEM photograph (3000x magnification) of the obtained particles is shown in FIG. From FIG. 2, it was confirmed that the particles had a non-porous internal structure. The volume average particle diameter was 11.7 μm. As a result of evaluating the light reflection performance of the obtained particles from visible light to near infrared rays, the value of R500/R1500 was 1.018.

(Comparative example 2)
Hollow particles were obtained in the same manner as in Example 1, except that Chromofine Black A1103 was not used as the black pigment. The volume average particle diameter was 9.8 μm.
A hollow particle-black pigment mixed powder was obtained by mixing 4.55 g of the obtained hollow particles and 0.45 g of Chromofine Black A1103 using a defoaming stirrer (manufactured by KURABO: Mazelstar KK-250). The mixing ratio of the hollow particles and the black pigment in the mixed powder was the same as the weight ratio of the resin component constituting the hollow particles obtained in Example 1 and the black pigment. As a result of evaluating the light reflection performance of the obtained mixed powder from visible light to near infrared rays, the value of R500/R1500 was 0.125.
(Comparative example 3)
A hollow particle-black pigment mixed powder was obtained by mixing 4.17 g of the hollow particles obtained in Comparative Example 2 and 0.83 g of Chromofine Black A1103 using a defoaming stirrer (Mazel Star). The mixing ratio of the hollow particles and the black pigment in the mixed powder was the same as the weight ratio of the resin component and the black pigment constituting the pigment-containing hollow particles obtained in Example 2. As a result of evaluating the light reflection performance of the obtained mixed powder from visible light to near infrared rays, the reflectance was 7.50% for R500, 87.83% for R1500, and the value of R500/R1500 was 0.085. Ta.
(Comparative example 4)
Hollow particles were obtained in the same manner as in Example 1, except that 5 g of acetylene carbon black (50% compressed) (Strem Chemicals, Inc.), which has high near-infrared light absorption, was used as the black pigment. The volume average particle diameter was 12.2 μm. As a result of evaluating the light reflection performance of the obtained particles from visible light to near infrared rays, the value of R500/R1500 was 1.385.
(Comparative example 5)
FIG. 2 shows an SEM photograph (4000x) of Chromofine Black A1103. From FIG. 2, the internal structure could not be confirmed. As a result of evaluating the light reflection performance from visible light to near infrared rays, the reflectance at R500 was 1.47%, the reflectance at R1500 was 84.27%, and the value of R500/R1500 was 0.017.
Table 1 shows the raw materials for producing the particles of the above Examples and Comparative Examples and the amounts used (g) thereof. FIG. 3 shows a graph of the reflectance of the particles of the above Examples and Comparative Examples versus the wavelength of light.

From FIG. 3 and Table 1, it can be seen that the pigment-containing hollow particles obtained from Examples have a lower reflectance in the ultraviolet and visible light range (~800 nm) than the particles of Comparative Example 1, and the paint color changes from dark to black. It was found that it is suitable for the addition of In addition, the pigment-containing hollow particles obtained in Examples were more effective in the near-infrared light region (800 to 2500 nm, especially 800 to 1500 nm) than the particles of Comparative Example 4, which used a black pigment with high near-infrared light absorption. ) had a high reflectance and was found to have better heat shielding performance.

(Evaluation of reflection characteristics of ultraviolet-visible-near-infrared light in paint sample)
When each particle was made into a paint, the reflectance to ultraviolet light, visible light, and near-infrared light was evaluated using the following procedure.
Add 2.5 g of each particle to 10 g of a commercially available water-based paint (Asahipen Co., Ltd., product name: Water-based Multi-Purpose Color Transparent Clear), mix with a defoaming stirrer (Mazerstar KK-250) to disperse, and prepare the evaluation paint. was created.
The coating material for evaluation was applied to the black side of the hiding rate 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 evaluating light reflectivity.
The reflectance of the sample plate to ultraviolet light, visible light, and near-infrared light was evaluated in the following order of points.

A UV-visible near-infrared spectrophotometer (Solid Spec 3700) manufactured by Shimadzu Corporation was used as a reflectance measuring device to measure the reflection characteristics of the coated surface of the sample plate from ultraviolet light to near-infrared light (wavelength 300 to 2500 nm). It was measured as reflectance (%). Note that the measurements were performed using a 60 mmΦ integrating sphere and barium sulfate as a standard white board. The results obtained are shown in FIG.
The pigment-containing hollow particles obtained in the examples have lower reflectance in the ultraviolet and visible light range (~800 nm) and are darkly colored compared to the particles of Comparative Example 1 in which the R500/R1500 value exceeds 0.5. It was found that it is suitable for addition to black paint.
The pigment-containing hollow particles obtained in Examples have lower reflectance in the ultraviolet and visible light range (~800 nm) than the particles of Comparative Examples 2 and 3, in which particles and pigments are simply mixed, and the color ranges from dark to black. It was found that it is more suitable for addition to paints, has a high reflectance in the near-infrared region (from 800 nm), and has better heat shielding performance.
The pigment-containing hollow particles obtained in Examples have a higher reflectance in the near-infrared region (from 800 nm) and have better heat shielding performance than the particles of Comparative Example 5 that do not have an internal porous structure. I understand.

(Coating composition manufacturing example 1)
2 parts by weight of the pigment-containing hollow 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: Super Hit) were mixed using a stirring and defoaming device. A coating composition was obtained by mixing for 3 minutes and defoaming for 1 minute.
The obtained coating composition was applied onto 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.

(Light-diffusing composition and light-diffusing film production example 1)
7.5 parts by weight of the pigment-containing hollow particles obtained in Example 1, 30 parts by weight of acrylic resin (manufactured by DIC Corporation, product name Acridic A811), and 10 parts by weight of a crosslinking agent (manufactured by DIC Corporation, product name VM-D). and 50 parts by weight of butyl acetate as a solvent were mixed for 3 minutes using a stirring defoaming device and defoamed for 1 minute to obtain a light-diffusing composition.
The obtained light-diffusing composition was applied onto 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 obtain a light-diffusing film. Ta.

(Cosmetic prescription example)
(Combination example 1)
Production and blending amount of powder foundation Pigment-containing 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 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 Preservative appropriate amount Fragrance appropriate amount/manufacturing method Pigment-containing hollow particles , red iron oxide, yellow iron oxide, black iron oxide, titanium oxide, mica, and talc are mixed in a Henschel mixer, and a mixed solution of liquid paraffin, octyldodecyl myristate, vaseline, and a preservative is added to this mixture to make a uniform mixture. Mix. After adding flavoring and mixing, the mixture is crushed and passed through a sieve. This is compression molded into a metal plate to obtain a powder foundation.

(Combination example 2)
Production and blending amount of cosmetic emulsion Pigment-containing 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) monooleate 2.0 parts by weight Polyethylene glycol 1500 3.0 parts by weight Triethanolamine 1.0 parts by weight Purified water 64.5 parts by weight Fragrance 0.5 parts by weight Preservative Appropriate amount/manufacturing method First , stearic acid, cetyl alcohol, vaseline, liquid paraffin, and polyethylene monooleate are heated and dissolved, pigment-containing hollow 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 aqueous phase and pre-emulsified, then uniformly emulsified using a homogenizer, and after the emulsification is cooled to 30°C while stirring to obtain a cosmetic emulsion.

Claims (6)

Pigment-containing hollow particles comprising a non-porous shell and an air space defined by the shell, and containing pigment particles, the shell having a plurality of protrusions on its inner wall, and the plurality of protrusions. The projections are connected to each other, and the pigment particles have a reflectance of 40% or more for near-infrared light including light with a wavelength of 800 to 1500 nm, and a reflectance of 10% to light with a wavelength of 400 to 700 nm. Pigment-containing hollow particles having the following properties and having a reflectance of 50% or more for light with a wavelength of 1200 to 1500 nm . The pigment-containing hollow particles according to claim 1 , wherein the pigment particles are contained in the pigment-containing hollow particles in an amount of 1 to 30% by weight. The pigment-containing hollow particles according to claim 1 or 2 , wherein the pigment-containing hollow particles have a volume average particle diameter of 1.0 to 50 μm, and the shell is composed of a crosslinked resin. The crosslinked resin is derived from a vinyl monofunctional monomer and a vinyl crosslinkable monomer, and the vinyl monofunctional monomer and the vinyl crosslinkable monomer are derived from a (meth)acrylic acid ester. The pigment-containing hollow particles according to claim 3 . Any one of claims 1 to 4 , wherein the pigment-containing hollow particles are used for applications selected from paint compositions, cosmetics, paper coating compositions, heat-insulating compositions, light-diffusing compositions, and light-diffusing films. Pigment-containing hollow particles according to item 1. A method for producing pigment-containing hollow particles according to any one of claims 1 to 5 ,
A mixture containing a vinyl monofunctional monomer, a vinyl crosslinkable monomer, a non-reactive solvent, a polymerization initiator, and pigment particles is added in the presence of a dispersion aid and a suspension stabilizer. A method for producing pigment-containing hollow particles, comprising a step of polymerizing in an aqueous medium.