Powder composition and cosmetic using same

Abstract

Provided is a powder composition that makes it possible to easily obtain a dispersion and that exhibits high dispersibility. This powder composition contains: a titanium oxide powder as a powder to be treated; at least one hydrophobing agent selected from the group consisting of a fatty acid, a silicone and a silane coupling agent; a surfactant; and an oil. The content of the surfactant is 0.1% or more and 50% or less of the weight of the powder to be treated, and the content of the oil is 0.1% or more and 50% or less of the weight of the powder to be treated.

Description

Powder composition and cosmetic using same

[0001] The present invention generally relates to a powder composition of titanium oxide, and more particularly to a powder composition of titanium oxide to be contained in a cosmetic and a cosmetic using the same.

[0002] In recent years, there has been a trend toward preference for O / W emulsion cosmetics that offer a fresh feel and excellent usability. Organic UV absorbers, which have been widely used until now, have recently been avoided due to concerns about their safety and their impact on the marine environment. To achieve both the usability and UV protection effect of O / W emulsion cosmetics, techniques for dispersing inorganic scattering agents that have been treated with a water repellent treatment into the internal oil phase have been investigated. For example, a common method involves dispersing an inorganic scattering agent that has been surface-treated with a silane coupling agent or silicone and has excellent dispersibility into the internal oil phase of an O / W emulsion cosmetic to prepare a formulation.

[0003] For example, Japanese Patent Laid-Open No. 2009-102236 (Patent Document 1) describes an O / W emulsion composition in which hydrophobic inorganic powder such as titanium oxide or zinc oxide is dispersed in an oil phase and is hydrophobized with a hydrophobizing agent such as a silicone or a higher fatty acid.

[0004] Furthermore, for example, Japanese Patent Application Laid-Open No. 2010-215602 (Patent Document 2) describes an oil-in-water sunscreen cosmetic containing zinc oxide and / or titanium oxide and silicone oil.

[0005] JP 2009-102236 A JP 2010-215602 A

[0006] When an inorganic scattering agent is dispersed in the internal oil phase of an O / W emulsion cosmetic, a small amount of oil in the internal phase is preferred to obtain a fresh feel when used. However, inorganic powders surface-treated with fatty acids tend to have lower dispersibility than those surface-treated with silane coupling agents or silicones. For this reason, powders surface-treated with fatty acids are often pre-dispersed in an oil using a bead mill or the like and used as a dispersion. When a dispersion in which powder surface-treated with fatty acids is dispersed in an oil is used, the amount of oil carried over from the dispersion into the cosmetic becomes too large, and the fresh feel desired for O / W emulsion cosmetics cannot be obtained.

[0007] Furthermore, when conventional fatty acid-treated powders are blended into the internal oil phase of O / W emulsion cosmetics, the fine titanium dioxide particles aggregate due to insufficient dispersibility, protruding from the emulsion particles, and the emulsion particles coalesce from these protruding points, resulting in problems with stability over time. Furthermore, even for powders that have been surface-treated with silane coupling agents or silicones, higher dispersibility and stability over time are desired.

[0008] SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a powder composition that is highly dispersible.

[0009] The powder composition according to the present invention comprises titanium oxide powder as the powder to be treated, at least one hydrophobic treatment agent selected from the group consisting of fatty acids, silicones, and silane coupling agents, a surfactant, and an oil agent, wherein the surfactant content is 0.1% or more and 50% or less of the weight of the powder to be treated, and the oil agent content is 0.1% or more and 50% or less of the weight of the powder to be treated.

[0010] In this way, a powder composition with high dispersibility can be provided.

[0011] The powder composition of the present invention and a cosmetic containing the same will be described in detail below, with specific examples. Note that the present invention is not limited to the embodiments shown below, and various modifications are possible within the scope of the technical concept of the present invention.

[0012] 1. Production of Powder Composition In one embodiment, the powder composition according to the present invention is produced by the following method.

[0013] 1.1 Production by Wet Processing To improve the dispersibility of fine particle titanium dioxide and ensure excellent UV protection, transparency, and stability over time when incorporated into cosmetics, the inventors focused not only on the content ratio of the treated powder to the surfactant or oil, but also on the production process. Fine particle powders, including titanium dioxide, tend to agglomerate easily. It is believed that agglomeration caused by thermal energy during drying is particularly dominant. Although particles eventually disintegrate somewhat through a milling process, many particles have secondary agglomeration diameters exceeding several micrometers. Therefore, the inventors focused on how to suppress agglomeration during drying. After extensive research, the inventors have succeeded in suppressing agglomeration during drying and improving wettability to oil by replacing water with surfactant and oil around the particles when they are in a highly dispersed state in water. Based on the inventors' findings, the production method of the powder composition of the present invention is preferably configured as follows.

[0014] The method for producing a powder composition according to the present invention preferably includes an alkalinization step in which an alkali metal hydroxide is added to an aqueous dispersion of hydrous titanium oxide to obtain an alkali metal titanate, an acidification step in which hydrochloric acid is added to the aqueous dispersion of the alkali metal titanate to obtain titanium oxide containing rutile crystals, and a mixing step in which the titanium oxide obtained in the acidification step is mixed with at least one hydrophobic treatment agent selected from the group consisting of fatty acids, silicones, and silane coupling agents, a surfactant, and an oil. In the method for producing a powder composition according to the present invention, the mixing step is more preferably a mixing step in which a metal oxide or metal hydroxide, a hydrophobic treatment agent, a surfactant, and an oil are mixed with the titanium oxide obtained in the acidification step. Examples of alkali metal hydroxides that can be used include lithium hydroxide, sodium hydroxide, and potassium hydroxide. Sodium hydroxide and potassium hydroxide are preferred.

[0015] In the method for producing a powder composition according to the present invention, the mixing step preferably includes a step of adding a surfactant and an oil after mixing titanium oxide and a hydrophobic treatment agent, or after mixing titanium oxide and a metal oxide or a metal hydroxide and a hydrophobic treatment agent, or a step of mixing titanium oxide and a metal oxide or a metal hydroxide and then adding a hydrophobic treatment agent, a surfactant and an oil.

[0016] The powder composition is produced, for example, by the following specific steps, but is not limited to this method.

[0017] (Step 1) An aqueous solution of titanyl sulfate crystals is heated to produce a hydrolyzed product, which is then filtered and washed to obtain a hydrous titanium dioxide cake. An aqueous sodium hydroxide solution is added to the cake while stirring, and the mixture is heated and stirred to obtain titanium dioxide hydrate. The resulting suspension of titanium dioxide hydrate is filtered, the cake is thoroughly washed, and water is added to the washed cake to form a slurry and adjust the concentration. Hydrochloric acid is then added while stirring, and water is added to adjust the concentration. The mixture is then heated and aged to produce a slurry containing rutile titanium dioxide crystals.

[0018] (Step 2) A water-soluble aluminum salt is added to the obtained slurry, and then an aqueous sodium hydroxide solution is added to adjust the pH, followed by aging. After aging, the slurry is heated, a hydrophobic treatment agent is added, and the slurry is aged.

[0019] (Step 3) After aging, an aqueous solution of sodium hydroxide or an aqueous solution of sulfuric acid is added to adjust the pH of the slurry.

[0020] (Step 4) After adjusting the pH, a surfactant is added to the slurry and the slurry is aged. The amount of surfactant added is 0.1% to 50% of the weight of the powder to be treated.

[0021] (Step 5) After aging, an oil is added to the slurry, and the slurry is aged. The amount of oil added is 0.1% to 50% of the weight of the powder to be treated.

[0022] (Step 6) After aging, the pH of the slurry is adjusted by adding an aqueous sodium hydroxide solution or an aqueous sulfuric acid solution, and after aging, the slurry is filtered, washed, and dried. The resulting dried product can be pulverized to a desired particle size to produce a powder composition.

[0023] 1.2 Production Method by Dry Treatment The slurry obtained in the wet treatment step 3 above is filtered, washed, and dried, and the resulting dried product is pulverized to a desired particle size to obtain a hydrophobized powder to be treated. The hydrophobized powder to be treated may also be produced by another method, such as a method of dry mixing the powder to be treated and a hydrophobizing treatment agent, or a method of mixing the powder to be treated, the hydrophobizing treatment agent, and a solvent, and then removing the solvent by heat treatment or reduced pressure treatment.

[0024] A powder composition can be produced by adding a surfactant and an oil to the hydrophobized powder while stirring it in a mixer, and pulverizing the resulting powder to a desired particle size. The amount of surfactant added is 0.1% to 50% of the weight of the powder, and the amount of oil added is 0.1% to 50% of the weight of the powder.

[0025] 2. Powder to be treated Titanium oxide powder as the powder to be treated is produced by a known method. The crystalline form of the powder to be treated is selected depending on the intended use. For example, it is preferable that the titanium oxide powder contains rutile crystals. The particle size is selected depending on the intended use, etc. For example, when blended in an emulsion cosmetic, the average primary particle size is preferably 5 nm to 50 nm, and more preferably 8 nm to 30 nm. Here, the average primary particle size refers to the number-average particle size of the Heywood diameter (diameter equivalent to a circle with a projected area) obtained by analyzing an image of titanium oxide particles (number of particles: 100) taken with a transmission electron microscope (TEM) using image analysis particle size distribution measurement software.

[0026] 3. Hydrophobic Treatment Agent The hydrophobic treatment agent is at least one selected from the group consisting of fatty acids, silicones, and silane coupling agents. By mixing with the powder to be treated or by applying it to the powder to be treated by other means, it coats at least a portion of the surface of the powder to be treated, preferably the entire surface. As fatty acids, stearic acid or its salts, lauric acid or its salts, myristic acid or its salts, palmitic acid or its salts, isostearic acid or its salts are preferred, and stearic acid or its salts, isostearic acid or its salts are more preferred. As silicones, dimethicone, hydrogen dimethicone, methylphenyl polysiloxane, triethoxysilylethyl polydimethylsiloxyethylhexyl dimethicone, trimethylsiloxysilicate, etc. can be used. Examples of silane coupling agents that can be used include methyltrimethoxysilane, dimethyldimethoxysilane, phenyltrimethoxysilane, methyltriethoxysilane, dimethyldiethoxysilane, phenyltriethoxysilane, n-propyltrimethoxysilane, n-propyltriethoxysilane, hexyltrimethoxysilane, hexyltriethoxysilane, octyltriethoxysilane (triethoxycaprylylsilane), and decyltrimethoxysilane. The content of the hydrophobic treatment agent in the powder composition is preferably 7% or more and 30% or less, and more preferably 10% or more and 30% or less, of the weight of the powder to be treated. When a fatty acid salt is used as the hydrophobic treatment agent, the content of the hydrophobic treatment agent in the powder composition is the value calculated by replacing the counter ions contained in the salt with hydrogen ions (i.e., the value calculated in terms of fatty acid).

[0027] 4. Surfactants The surfactant is mixed with the powder to be treated or applied to the powder to be treated by other methods, thereby coating at least a portion of the surface of the powder to be treated, and preferably coating the entire surface. The surfactant need only physically adhere to the surface of the powder to be treated, and does not have to be chemically bonded to the surface of the powder to be treated. From the viewpoint of improving dispersibility of the cosmetic in the oil phase, it is preferable to use a surfactant with an HLB of 10 or less, and more preferably 8 or less. Specific examples of surfactants include PEG-5 phytosterol, PEG-10 hydrogenated castor oil, polyoxyethylene glyceryl isostearate, polyglyceryl-2 isostearate, polyglyceryl-4 isostearate, sorbitan olivate, glyceryl oleate, sorbitan oleate, polyglyceryl-2 oleate, polyglyceryl-4 oleate, oleth-2, polyglyceryl diisostearate, and polyglyceryl diisostearate. glyceryl-3, self-emulsifying propylene glycol monostearate, sucrose distearate, condensed polyglyceryl ricinoleate, lipophilic glyceryl monooleate, lipophilic glyceryl monostearate, PEG-2 stearate, PEG-25 stearate, PG stearate, PG (SE) stearate, glyceryl stearate, sorbitan stearate, polyglyceryl-2 stearate, polyglyceryl-4 stearate, Steareth-2, steareth-3, sorbitan sesquiisostearate, sorbitan sesquioleate, sorbitan ceteth-3 sesquistearate, PEG-5 glyceryl triisostearate, PEG-10 glyceryl triisostearate, polyoxyethylene glyceryl triisostearate, sorbitan trioleate, sorbitan tristearate, sorbitan palmitate, glyceryl behenate, polyglyceryl pentaisostearate, polyglyceryl-10 pentaisostearate, polyglyceryl pentaoleate, polyglyceryl-10 pentaoleate, decaglyceryl pentastearate, polyglyceryl-10 pentastearate, polyoxyethylene isostearyl ether, polyoxyethylene oleyl ether, polyoxyethylene stearyl ether, polyoxyethylene phytosterol, polyoxyethylene behenyl ether,Polyoxyethylene lauryl ether, sucrose polystearate, polyhydroxystearic acid, polyglyceryl-3 polyricinoleate, polyglyceryl-5 polyricinoleate, polyglyceryl-6 polyricinoleate, glyceryl monoisostearate, sorbitan monoisostearate, polyglyceryl monoisostearate, sorbitan monooleate, polyglyceryl monooleate, sorbitan monostearate, propylene glycol monostearate, polyoxyethylene sorbitan monostearate, polyglyceryl monostearate, sorbitan monopalmitate, sorbitan monolaurate, sorbitan cocoate, sorbitan laurate, laureth-2, diisostearyl malate, in particular polyhydroxystearic acid, diisostearyl malate, and sesquiisostearate. Rubitan, glyceryl-5 polyricinoleate, PEG-11 methyl ether dimethicone, PEG-10 dimethicone, PEG / PPG / 22 butyl ether dimethicone, PEG-3 dimethicone, cetyl PEG / PPG-10 / 1 dimethicone, PEG-9 polydimethylsiloxyethyl dimethicone, lauryl PEG-9 polydimethylsiloxyethyl dimethicone, polyglyceryl-3 disiloxane dimethicone, polyglyceryl-3 polydimethylsiloxyethyl dimethicone, lauryl polyglyceryl-3 polydimethylsiloxyethyl dimethicone, (acrylates / ethylhexyl acrylate / dimethicone methacrylate) copolymer, cetyl diglyceryl tris(trimethylsiloxy)silylethyl dimethicone, lauryl (PEG-10) tris(trimethylsiloxy)silylethyl dimethicone, and the like are preferably used. The content of the surfactant in the powder composition is 0.1% or more and 50% or less of the weight of the powder to be treated, preferably 0.1% or more and 30% or less, more preferably 0.1% or more and 10% or less, even more preferably 2% or more and 8% or less, and most preferably 4% or more and 6% or less.

[0028] 5. Oils The oil is mixed with the powder to be treated or applied to the powder to be treated by other methods, thereby coating at least a portion of the surface of the powder to be treated, and preferably coating the entire surface. The oil need only physically adhere to the surface of the powder to be treated, and does not have to be chemically bonded to the surface of the powder to be treated. Examples of oils include isobutene, hydrogenated polyisobutene, isohexadecane, isodecane, isododecane, eicosane, isoeicosane, squalane, liquid paraffin, light liquid isoparaffin, heavy liquid isoparaffin, stearyl 2-ethylhexanoate, cetyl 2-ethylhexanoate, cetostearyl 2-ethylhexanoate, N-lauroyl sarcosine isopropyl, (adipic acid / 2-ethylhexanoic acid / stearic acid) glyceryl oligoester, diisobutyl adipate, adipate Diisopropyl isostearate, (C12-15) alkyl benzoate, (C15-19) alkane, 2-hexyldecyl isostearate, isostearyl isostearate, isocetyl isostearate, isopropyl isostearate, ethyl isostearate, octyldodecyl isostearate, hydrogenated castor oil isostearate, cholesteryl isostearate, hydrogenated castor oil isostearate, phytosteryl isostearate, hexyldecyl isostearate, isostearic acid Pentaerythritol, 2-ethylhexyl isononanoate, isotridecyl isononanoate, isononyl isononanoate, ethylhexyl isononanoate, isotridecyl isopelargonate, octyl isopelargonate, stearyl ethylhexanoate, glyceryl ethylhexanoate / stearate / adipate, cetyl ethylhexanoate, cetearyl ethylhexanoate, octyl hydroxystearate, cholesteryl hydroxystearate, stearyl octanoate, cetyl octanoate, octyl Cetostearyl tanoate, ethyl oleate, acetyl triethyl citrate, acetyl tributyl citrate, tri-2-octyldodecyl citrate, triethyl citrate, trioctyldodecyl citrate, tributyl citrate, glycerin fatty acid ester adipic acid condensate, di-2-ethylhexyl succinate, diethylhexyl succinate, dioctyl succinate, neopentyl glycol di-ethylhexanoate, glyceryl diisostearate, neopentyl glycol diethylhexanoate,Neopentyl glycol dioctanoate, PG dicaprylate, propylene glycol dicaprylate / caprate, PG dicaprylate / caprate, propylene glycol dicaprylate, PG dicaprate, neopentyl glycol dicaprate, propylene glycol dicaprate, diisopropyl dilinoleate, 2-ethylhexyl stearate, ethylhexyl stearate, butyl stearate, diisopropyl dimerate, hydrogenated castor oil dimer dilinoleate, dialkyl (14,15) carbonate, dicaprylyl carbonate, tetra 2-ethylhexyl Pentaerythrityl hexanoate, pentaerythrityl tetraisostearate, pentaerythrityl tetraisostearate, pentaerythrityl tetraethylhexanoate, pentaerythrityl tetraoctanoate, dipentaerythrityl tetra(hydroxystearate / isostearate), glyceryl tri-2-ethylhexanoate, trimethylolpropane tri-2-ethylhexanoate, triisostearin, glyceryl triisostearate, triethylhexanoin, trimethylolpropane triethylhexanoate, glyceryl trioctanoate, triisostearin, Trimethylolpropane Lactate, Tricaprylin, Caprylic / Capric Triglyceride, Caprylic / Capric / Myristic / Stearic Triglyceride, Caprylic / Capric Triglyceride, Caprylic / Capric / Myristic / Stearic Triglyceride, Glyceryl Tricaprylate, Tribehenin, Glyceryl Tribehenate, Octyldodecyl Lactate, Cetyl Lactate, Myristyl Lactate, 2-Octyldodecyl Neopentanoate, Octyldodecyl Neopentanoate, 2-Ethylhexyl Palmitate, Isopropyl Palmitate propyl, ethylhexyl palmitate, octyl palmitate, cetyl palmitate, 2-ethylhexyl hydroxystearate, ethylhexyl hydroxystearate, cholesteryl hydroxystearate, phytosteryl hydroxystearate, 2-octyldodecyl pivalate, dipentaerythrityl hexahydroxystearate, dipentaerythrityl hexahydroxystearate, dipentaerythrityl hexahydroxystearate / hexastearic acid / hexarosinate, isostearyl myristate, octyldodecyl myristate,Myristyl myristate, hexyl laurate, methylheptyl laurate, isopropyl lauroyl sarcosine, and diisostearyl malate are particularly preferred, and hydrogenated polyisobutene, (C12-15) alkyl benzoate, squalane, (C15-19) alkane, tri(caprylic / capric)glyceryl, triethylhexanoin, hexyl laurate, cyclopentasiloxane, dimethicone, trisiloxane, ethyl methicone, methyl trimethicone, diphenylsiloxyphenyl trimethicone, and caprylyl methicone are particularly preferred. The content of the oil in the powder composition is 0.1% to 50% of the weight of the powder to be treated, preferably 0.1% to 30%, more preferably 0.1% to 10%, even more preferably 2% to 8%, and most preferably 4% to 6%.

[0029] 6. Metal Oxide or Metal Hydroxide When producing the powder to be treated, a metal oxide or metal hydroxide may be added to and mixed with the powder to be treated. Alternatively, a water-soluble metal salt may be added to an aqueous slurry of the powder to be treated, and then an aqueous sodium hydroxide solution or an aqueous sulfuric acid solution may be added to adjust the pH, followed by aging to mix the metal oxide or metal hydroxide with the powder to be treated. Examples of metal oxides or metal hydroxides that can be used include oxides or hydroxides of aluminum, zinc, titanium, zirconium, silicon, and cerium, with aluminum oxide or hydroxide being preferred. The main effect of these metal oxides or metal hydroxides is to suppress the photoactivity of the powder to be treated.

[0030] 7. Properties of Powder Composition The powder composition of the present invention may be in any state ranging from a powdery form to a paste-like form that does not have the fluidity of a liquid. For example, it may be in the form of soybean pulp.

[0031] 8. Cosmetics The powder composition of the present invention has extremely high dispersibility, and therefore when incorporated into the internal oil phase of an O / W emulsion cosmetic, it exhibits little aggregation, making it possible to provide a highly stable emulsion cosmetic. The powder composition of the present invention also provides excellent UV protection effects when incorporated into the oil phase of a W / O emulsion cosmetic. The powder composition of the present invention is not limited to the cosmetic to be incorporated. For example, the powder composition of the present invention may be incorporated into a cosmetic solely as a raw material for imparting UV protection effects, or the powder composition of the present invention may be incorporated in combination with other raw materials having UV protection effects (titanium oxide, zinc oxide, cerium oxide, iron oxide, organic UV absorbers, etc.). In this case, the raw material having UV protection effects to be incorporated may be incorporated into either the aqueous phase or the oil phase.

[0032] When the powder composition of the present invention is blended into an O / W emulsion cosmetic, the blending method can be, for example, by adding the powder composition of the present invention to a mixture of raw materials for the oil phase, and then adding a mixture of raw materials for the aqueous phase while stirring.

[0033] The present invention can be summarized as follows.

[0034] (1) The powder composition according to the present invention comprises a titanium oxide powder as a powder to be treated, at least one hydrophobic treatment agent selected from the group consisting of fatty acids, silicones, and silane coupling agents, a surfactant, and an oil agent, wherein the content of the surfactant is 0.1% or more and 50% or less of the weight of the powder to be treated, and the content of the oil agent is 0.1% or more and 50% or less of the weight of the powder to be treated.

[0035] (2) In the powder composition of (1) of the present invention, the content of the hydrophobic treatment agent is preferably 7% or more and 30% or less of the weight of the powder to be treated.

[0036] (3) The powder composition of (1) or (2) of the present invention preferably has a total light transmittance at a wavelength of 300 nm of 10% or less, and a value of (300 nm transmittance) / (400 nm transmittance) of 0.2 or less.

[0037] (4) A cosmetic according to the present invention contains the powder composition according to any one of (1) to (3).

[0038] (5) A method for producing a powder composition according to the present invention includes an alkalinization step of adding an alkali metal hydroxide to an aqueous dispersion of hydrous titanium oxide to obtain an alkali metal titanate, an acidification step of adding hydrochloric acid to the aqueous dispersion of the alkali metal titanate to obtain titanium oxide containing rutile crystals, and a mixing step of mixing the titanium oxide obtained in the acidification step with at least one hydrophobic treatment agent selected from the group consisting of fatty acids, silicones, and silane coupling agents, a surfactant, and an oil agent.

[0039] (6) In the method (5) of the present invention, the mixing step preferably includes mixing the titanium oxide and the hydrophobic treatment agent, and then adding a surfactant and an oil agent.

[0040] (7) In the method (5) of the present invention, the mixing step is preferably a step of mixing at least a metal oxide or metal hydroxide, a hydrophobic treatment agent, a surfactant, and an oil agent with the titanium oxide obtained in the acidification step.

[0041] (8) In the method (7) of the present invention, the mixing step preferably includes mixing titanium oxide, a metal oxide or metal hydroxide, and a hydrophobic treatment agent, and then adding a surfactant and an oil agent.

[0042] (9) In the method (7) of the present invention, the mixing step preferably includes mixing titanium oxide with a metal oxide or metal hydroxide, and then adding a hydrophobic treatment agent, a surfactant, and an oil agent.

[0043] The powder composition according to the present invention and cosmetics using the same will be described in more detail below, showing specific production examples and test results.

[0044] <Production of Powder Composition> Example 1 (Step 1) An aqueous solution of titanyl sulfate crystals (TM crystals manufactured by Teika Corporation) was heated to produce a hydrolyzate, which was then filtered and washed to obtain 35 kg of hydrous titanium oxide cake (titanium oxide content: TiO ２To the mixture (equivalent to 10 kg of titanium dioxide in terms of ammonium hydroxide), 40 kg of a 48% aqueous solution of sodium hydroxide was added with stirring, and the mixture was heated to a temperature in the range of 95 to 105°C and stirred for 2 hours. The titanium dioxide hydrate suspension was then filtered, and the cake was thoroughly washed. Approximately 25 kg of water was added to the washed cake to form a slurry, and TiO ２ The converted concentration was adjusted to 220 g / L. Then, 14 kg of 35% hydrochloric acid was added while stirring, and water was added to the mixture. ２ The concentration of the slurry was adjusted to 160 g / L in terms of projected area. 14.0 kg of 35% hydrochloric acid was added thereto, and the mixture was heated and aged at 95°C to 100°C for 2 hours. The solid particles in this slurry showed a rutile-type titanium dioxide crystal structure by X-ray diffraction, and the average primary particle diameter (the number-average particle diameter of the Heywood diameter (diameter equivalent to a circle with a projected area) obtained by analyzing an image of titanium oxide particles (number of particles: 100) taken with a transmission electron microscope (TEM) using image analysis particle size distribution measurement software (Mac-View, manufactured by Mountec Co., Ltd.)) was 15 nm.

[0045] (Step 2) The concentration of the obtained titanium oxide slurry was adjusted to 70 g / L. 20 L of this slurry (TiO ２ (equivalent to 1.4 kg) and Al ２ O ３ 1,133 mL of a polyaluminum chloride aqueous solution containing 123.6 g / L (based on titanium dioxide) ２ O ３ While stirring, 248 g of sodium stearate (16.5% by weight in terms of fatty acids relative to titanium dioxide) was added. The pH was adjusted to 6.0 by adding an aqueous sodium hydroxide solution, and the mixture was aged for 30 minutes. The slurry was heated to 85°C, and then 248 g of sodium stearate (16.5% by weight in terms of fatty acids relative to titanium dioxide) was added. The pH gradually increased, reaching 7.0 after 10 minutes. The slurry was aged for 1 hour.

[0046] (Step 3) After aging, the pH value of the slurry was adjusted to 7.5 by adding an aqueous solution of sodium hydroxide or an aqueous solution of sulfuric acid.

[0047] (Step 4) 70 g (5% by weight of the active ingredient relative to the titanium dioxide) of polyhydroxystearic acid (manufactured by Nisshin Oillio Group, Ltd. / trade name: Salacos HS-6C) was added and aged for 15 minutes.

[0048] (Step 5) After aging, 70 g (5% by weight in terms of active ingredient relative to titanium dioxide) of hexyl laurate (manufactured by Kokyu Alcohol Kogyo Co., Ltd. / trade name: KAK HL) was added, and the mixture was aged for 30 minutes.

[0049] (Step 6) After aging, the pH value of the slurry was adjusted to 5.5 by adding an aqueous sodium hydroxide solution or an aqueous sulfuric acid solution, and then aging was continued for 10 minutes. The slurry was filtered, washed, and dried at 85°C for 15 hours. The dried product was pulverized using an Eck atomizer to produce the powder composition of Example 1.

[0050] Example 2 A powder composition was produced in the same manner as in Example 1, except that sodium stearate in step 2 was changed to sodium laurate.

[0051] Example 3 A powder composition was produced in the same manner as in Example 1, except that sodium stearate in step 2 was changed to sodium myristate.

[0052] Example 4 A powder composition was produced in the same manner as in Example 1, except that sodium stearate in step 2 was changed to sodium palmitate.

[0053] Example 5 A powder composition was produced in the same manner as in Example 1, except that sodium stearate in step 2 was changed to isostearic acid.

[0054] Example 6 A powder composition was produced in the same manner as in Example 1, except that the amount of polyhydroxystearic acid added in step 4 was changed to 1.4 g (0.1% by weight in terms of the active ingredient relative to the titanium dioxide).

[0055] Example 7 A powder composition was produced in the same manner as in Example 1, except that the amount of polyhydroxystearic acid added in step 4 was changed to 140 g (10% by weight in terms of the active ingredient relative to the titanium dioxide).

[0056] Example 8 A powder composition was produced in the same manner as in Example 1, except that the amount of hexyl laurate added in step 5 was changed to 1.4 g (0.1% by weight in terms of the active ingredient relative to titanium dioxide).

[0057] Example 9 A powder composition was produced in the same manner as in Example 1, except that the amount of hexyl laurate added in step 5 was changed to 140 g (10% by weight in terms of the active ingredient relative to the titanium dioxide).

[0058] Example 10 A powder composition was produced in the same manner as in Example 1, except that the amount of sodium stearate added in step 2 was changed to 155 g (10.3% by weight in terms of fatty acid relative to titanium dioxide).

[0059] Example 11 A powder composition was produced in the same manner as in Example 1, except that the amount of sodium stearate added in step 2 was changed to 440 g (29.2% by weight in terms of fatty acid relative to titanium dioxide).

[0060] Example 12 A powder composition was produced in the same manner as in Example 1, except that in step 4, polyhydroxystearic acid was changed to diisostearyl malate.

[0061] Example 13 A powder composition was produced in the same manner as in Example 1, except that in step 4, polyhydroxystearic acid was changed to sorbitan sesquiisostearate.

[0062] Example 14 A powder composition was produced in the same manner as in Example 1, except that polyhydroxystearic acid in step 4 was changed to polyglyceryl-5 polyricinoleate.

[0063] Example 15 A powder composition was produced in the same manner as in Example 1, except that in step 5, hexyl laurate was changed to hydrogenated polyisobutene.

[0064] Example 16 A powder composition was produced in the same manner as in Example 1, except that in step 5, hexyl laurate was changed to isododecane.

[0065] Example 17 A powder composition was produced in the same manner as in Example 1, except that in step 5, hexyl laurate was changed to a (C15-19) alkane.

[0066] Example 18 A powder composition was produced in the same manner as in Example 1, except that in step 5, hexyl laurate was changed to squalane.

[0067] Example 19 A powder composition was produced in the same manner as in Example 1, except that in step 5, hexyl laurate was changed to (C12-15) alkyl benzoate.

[0068] Example 20 A powder composition was produced in the same manner as in Example 1, except that in step 5, hexyl laurate was changed to glyceryl tri(caprylate / caprate).

[0069] Example 21 A powder composition was produced in the same manner as in Example 1, except that in step 5, hexyl laurate was changed to triethylhexanoin.

[0070] Example 22 An aqueous solution of titanyl sulfate crystals (TM crystals manufactured by Teika Corporation) was heated to produce a hydrolyzate, which was then filtered and washed to obtain 35 kg of hydrous titanium oxide cake (titanium oxide content: TiO ２ To the mixture (equivalent to 10 kg of ammonium hydroxide in terms of ammonium hydroxide content), 100 kg of a 48% aqueous solution of sodium hydroxide was added with stirring, and the mixture was heated to a temperature in the range of 95 to 105°C and stirred for 2 hours. The titanium dioxide hydrate suspension was then filtered, and the cake was thoroughly washed. Approximately 25 kg of water was added to the washed cake to form a slurry, and TiO ２ The converted concentration was adjusted to 220 g / L. Then, 1.7 kg of 35% hydrochloric acid was added while stirring, and water was added to the mixture. ２ The concentration was adjusted to 160 g / L in terms of saturation. 250 g of anhydrous sodium sulfate was added thereto, followed by 14.0 kg of 35% hydrochloric acid, and the mixture was heated and aged at 95°C to 100°C for 2 hours. The solid particles in this slurry showed a rutile-type titanium dioxide crystal structure by X-ray diffraction, and the average primary particle size was 8 nm.

[0071] The concentration of the obtained titanium oxide slurry was adjusted to 70 g / L. 20 L of this slurry (TiO ２ (equivalent to 1.4 kg) and Al ２ O ３ 1,472 mL of a polyaluminum chloride aqueous solution containing 123.6 g / L of titanium dioxide (Al ２ O ３While stirring, 440 g of sodium stearate (29.2% by weight in terms of fatty acids relative to titanium dioxide) was added. The pH was adjusted to 6.0 by adding an aqueous sodium hydroxide solution, and the mixture was aged for 30 minutes. The slurry was heated to 85°C, and then 440 g of sodium stearate (29.2% by weight in terms of fatty acids relative to titanium dioxide) was added. The pH gradually increased, reaching 7.0 after 10 minutes. The slurry was aged for 1 hour.

[0072] After aging, the pH value of the slurry was adjusted to 7.5 by adding an aqueous sodium hydroxide solution or an aqueous sulfuric acid solution, and 98 g of polyhydroxystearic acid (7% by weight in terms of active ingredient relative to titanium dioxide) was added and aged for 15 minutes.

[0073] After aging, 98 g of hexyl laurate (7% by weight in terms of the active ingredient relative to the titanium dioxide) was added and aging was continued for 30 minutes.

[0074] After aging, the pH value of the slurry was adjusted to 5.5 by adding an aqueous sodium hydroxide solution or an aqueous sulfuric acid solution, and then aged for 10 minutes. The slurry was filtered, washed, and dried at 85°C for 15 hours, and the dried product was pulverized using an Eck atomizer to produce a powder composition.

[0075] Example 23 Commercially available titanium oxide powder (manufactured by Teika Corporation: "MT-100Z" average primary particle diameter: 15 nm, surface treatment agent: aluminum (Al relative to titanium dioxide) ２ O ３ 500 g of stearic acid (16.5 wt % based on titanium dioxide) was placed in a mixer, and 20 g of polyhydroxystearic acid (5 wt % based on titanium dioxide in terms of active ingredient) was added with stirring, and the mixture was stirred for 10 minutes. 20 g of hexyl laurate (5 wt % based on titanium dioxide in terms of active ingredient) was then added with further stirring, and the mixture was stirred for 15 minutes. The titanium oxide powder thus obtained was pulverized using an Eck atomizer to produce a powder composition.

[0076] Example 24 An aqueous solution of titanyl sulfate crystals (TM crystals manufactured by Teika Corporation) was heated to produce a hydrolyzate, which was then filtered and washed to obtain 35 kg of hydrous titanium oxide cake (titanium oxide content: TiO ２To the mixture (equivalent to 10 kg of ammonium hydroxide in terms of ammonium hydroxide content), 100 kg of a 48% aqueous solution of sodium hydroxide was added with stirring, and the mixture was heated to a temperature in the range of 95 to 105°C and stirred for 2 hours. The titanium dioxide hydrate suspension was then filtered, and the cake was thoroughly washed. Approximately 25 kg of water was added to the washed cake to form a slurry, and TiO ２ The converted concentration was adjusted to 220 g / L. Then, 1.7 kg of 35% hydrochloric acid was added while stirring, and water was added to the mixture. ２ The concentration was adjusted to 160 g / L in terms of conversion. 250 g of anhydrous sodium sulfate was added thereto, followed by 14.0 kg of 35% hydrochloric acid, and the mixture was heated and aged at 95°C to 100°C for 2 hours. X-ray diffraction showed that the solid particles in this slurry had a rutile-type titanium dioxide crystal structure.

[0077] The concentration of the obtained titanium oxide slurry was adjusted to 70 g / L. 20 L of this slurry (TiO ２ To a slurry of 1.4 kg (equivalent to 1.4 kg), aqueous ammonia was added to adjust the pH to 6.0, the slurry was heated to 60°C and aged, and then the pH was adjusted to 6.0 again with aqueous ammonia, and the slurry was filtered and washed to obtain a washed cake. The cake was dispersed in water again, heated to 60°C, and then aqueous ammonia was added to adjust the pH to 7.5 and aged. After aging, the pH was adjusted to 7.5 again with aqueous ammonia, and the slurry was filtered and washed to obtain a washed cake. The washed cake was placed in a dryer (150°C) to remove moisture, and a titanium oxide powder (dry product) was obtained.

[0078] The titanium oxide powder (dried product) was calcined at 480°C for 120 minutes and pulverized to obtain a titanium oxide powder (calcined product). The average primary particle diameter of the titanium oxide powder (calcined product) was 30 nm. Water was added to the obtained titanium oxide powder (calcined product) to adjust the concentration to 10 g / L. 10 L of the above titanium oxide slurry (TiO ２A mixture of titanium dioxide and titanium dioxide (1.0 kg in terms of fatty acids) was heated to 85°C, and 115 g of sodium stearate (10.7 wt% in terms of fatty acids relative to titanium dioxide) was added. The pH gradually increased, reaching 7.0 after 10 minutes. This slurry was aged for 1 hour. The pH after aging for 1 hour was 9.0. After aging, the pH of the slurry was adjusted to 6.7 by adding an aqueous sodium hydroxide solution or an aqueous sulfuric acid solution, and then aged for 30 minutes. The slurry was filtered, washed, and dried at 105°C for 15 hours, and the dried product was pulverized using an Eck atomizer. 500 g of the titanium oxide powder thus obtained was placed in a mixer in the same manner as in Example 23, and treated with polyhydroxystearic acid and hexyl laurate under the same conditions. The titanium oxide powder thus obtained was pulverized using an Eck atomizer to produce a powder composition.

[0079] Example 25 A powder composition was produced in the same manner as in Example 1, except that in step 5, polyhydroxystearic acid was changed to sorbitan sesquiisostearate and hexyl laurate was changed to a (C15-19) alkane.

[0080] Example 26 A powder composition was produced in the same manner as in Example 1, except that in step 5, polyhydroxystearic acid was changed to sorbitan sesquiisostearate and hexyl laurate was changed to (C12-15) alkyl benzoate.

[0081] Example 27 A powder composition was produced in the same manner as in Example 1, except that polyhydroxystearic acid in step 5 was changed to polyglyceryl-10 (isostearate / succinate).

[0082] Example 28 A powder composition was produced in the same manner as in Example 1, except that in step 5, polyhydroxystearic acid was changed to polyglyceryl-5 polyricinoleate and hexyl laurate was changed to (C12-15) alkyl benzoate.

[0083] Example 29 A powder composition was produced in the same manner as in Example 1, except that in step 5, polyhydroxystearic acid was changed to polyglyceryl-5 polyricinoleate and hexyl laurate was changed to a (C15-19) alkane.

[0084] Example 30 Commercially available titanium oxide powder (manufactured by Teika Corporation: "MT-100Z" average primary particle diameter: 15 nm, surface treatment agent: aluminum (Al relative to titanium dioxide) ２ O ３ 500 g of stearic acid (16.5 wt % based on titanium dioxide) was placed in a mixer, and 20 g of sorbitan sesquiisostearate (5 wt % based on titanium dioxide in terms of active ingredient) was added with stirring, and the mixture was stirred for 10 minutes. 20 g of (C12-15) alkyl benzoate (5 wt % based on titanium dioxide in terms of active ingredient) was then added with further stirring, and the mixture was stirred for 15 minutes. The titanium oxide powder thus obtained was pulverized using an Eck atomizer to produce a powder composition.

[0085] Example 31 Commercially available titanium oxide powder (manufactured by Teika Corporation: "MT-100Z" average primary particle diameter: 15 nm, surface treatment agent: aluminum (Al relative to titanium dioxide) ２ O ３ 500 g of stearic acid (16.5 wt % based on titanium dioxide) was placed in a mixer, and 20 g of sorbitan sesquiisostearate (5 wt % based on titanium dioxide in terms of active ingredients) was added with stirring, and the mixture was stirred for 10 minutes. 20 g of (C15-19) alkane (5 wt % based on titanium dioxide in terms of active ingredients) was then added with further stirring, and the mixture was stirred for 15 minutes. The titanium oxide powder thus obtained was pulverized using an Eck atomizer to produce a powder composition.

[0086] Example 32 Commercially available titanium oxide powder (manufactured by Teika Corporation: "MT-05"), average primary particle size: 10 nm, surface treatment agent: silicon (SiO relative to titanium dioxide) ２ 5% by weight in terms of titanium dioxide), aluminum (Al ２ O ３500 g of titanium dioxide powder (10% by weight in terms of active ingredient relative to titanium dioxide) was placed in a mixer, and while stirring, 65 g of dimethicone (15% by weight in terms of active ingredient relative to titanium dioxide) was added, and the mixture was stirred for 15 minutes. Further, 22 g of PEG-9 polydimethylsiloxyethyl dimethicone (5% by weight in terms of active ingredient relative to titanium dioxide) was added, and the mixture was stirred for 10 minutes. Further, while continuing to stir, 22 g of dimethicone (5% by weight in terms of active ingredient relative to titanium dioxide) was added, and the mixture was stirred for 15 minutes. The titanium dioxide powder thus obtained was pulverized using an Eck atomizer to produce a powder composition.

[0087] Example 33 Commercially available titanium oxide powder (manufactured by Teika Corporation: "MT-05"), average primary particle diameter: 10 nm, surface treatment agent: silicon (SiO relative to titanium dioxide) ２ 5% by weight in terms of titanium dioxide), aluminum (Al ２ O ３ 500 g of titanium dioxide powder (10% by weight in terms of active ingredients) was placed in a mixer, and while stirring, 65 g of dimethicone (15% by weight in terms of active ingredients relative to titanium dioxide) was added and stirred for 15 minutes. Further, 22 g of polyglyceryl-3 polydimethylsiloxyethyl dimethicone (5% by weight in terms of active ingredients relative to titanium dioxide) was added and stirred for 10 minutes. Further, while continuing stirring, 22 g of dimethicone (5% by weight in terms of active ingredients relative to titanium dioxide) was added and stirred for 15 minutes. The titanium oxide powder thus obtained was pulverized using an Eck atomizer to produce a powder composition.

[0088] Example 34 Commercially available titanium oxide powder (manufactured by Teika Corporation: "MT-05"), average primary particle size: 10 nm, surface treatment agent: silicon (SiO relative to titanium dioxide) ２ 5% by weight in terms of titanium dioxide), aluminum (Al ２ O ３500 g of titanium dioxide powder (10% by weight in terms of active ingredient) was placed in a mixer, and while stirring, 96 g of triethoxycaprylylsilane (22% by weight in terms of active ingredient based on titanium dioxide) was added, and the mixture was stirred for 15 minutes. 22 g of sorbitan sesquiisostearate (5% by weight in terms of active ingredient based on titanium dioxide) was then added, and the mixture was stirred for 10 minutes. 22 g of (C12-15) alkyl benzoate (5% by weight in terms of active ingredient based on titanium dioxide) was then added, and the mixture was stirred for 15 minutes, while continuing to stir. The titanium dioxide powder thus obtained was pulverized using an Eck atomizer to produce a powder composition.

[0089] Example 35 500 g of the titanium oxide powder (calcinated product) obtained in Example 24 was placed in a mixer, and 34 g of dimethicone (6.8% by weight in terms of active ingredient relative to titanium dioxide) was added while stirring, and the mixture was stirred for 15 minutes. Further, 25 g of PEG-9 polydimethylsiloxyethyl dimethicone (5% by weight in terms of active ingredient relative to titanium dioxide) was added, and the mixture was stirred for 10 minutes. Further, while continuing stirring, 25 g of dimethicone (5% by weight in terms of active ingredient relative to titanium dioxide) was added, and the mixture was stirred for 15 minutes. The titanium oxide powder obtained in this way was pulverized using an Eck atomizer to produce a powder composition.

[0090] Example 36 The concentration of the titanium oxide slurry (average primary particle diameter: 8 nm) obtained in Example 22 was adjusted to 70 g / L. 20 L of this slurry (TiO ２ (equivalent to 1.4 kg) and Al ２ O ３ 1,472 mL of a polyaluminum chloride aqueous solution containing 123.6 g / L of titanium dioxide (Al ２ O ３While stirring, a solution of 13% by weight of sodium hydroxide was added to the slurry. The pH was adjusted to 6.0, and the slurry was aged for 30 minutes. The slurry was heated to 85°C, and 440 g of sodium stearate (29.2% by weight in terms of fatty acids relative to titanium dioxide) was added. During this time, the pH gradually increased, reaching pH 7.0 after 10 minutes. The slurry was aged for 1 hour. After aging, the pH of the slurry was adjusted to 7.5 by adding an aqueous sodium hydroxide solution or an aqueous sulfuric acid solution, and 700 g of sorbitan sesquiisostearate (50% by weight in terms of active components relative to titanium dioxide) was added, followed by aging for 15 minutes. After aging, 70 g of (C12-15) alkyl benzoate (5% by weight in terms of active components relative to titanium dioxide) was added, and the slurry was aged for 30 minutes. After aging, the pH value of the slurry was adjusted to 5.5 by adding an aqueous sodium hydroxide solution or an aqueous sulfuric acid solution, and then aged for 10 minutes. The slurry was filtered, washed, and dried at 85°C for 15 hours, and the dried product was pulverized using an Eck atomizer to produce a powder composition.

[0091] Example 37 The concentration of the titanium oxide slurry (average primary particle diameter: 8 nm) obtained in Example 22 was adjusted to 70 g / L. 20 L of this slurry (TiO ２ (equivalent to 1.4 kg) and Al ２ O ３ 1,472 mL of a polyaluminum chloride aqueous solution containing 123.6 g / L of titanium dioxide (Al ２ O ３While stirring, a solution of 13% by weight of sodium hydroxide was added to the slurry. The pH was adjusted to 6.0, and the slurry was aged for 30 minutes. The slurry was heated to 85°C, and 440 g of sodium stearate (29.2% by weight in terms of fatty acids relative to titanium dioxide) was added. During this time, the pH gradually increased, reaching pH 7.0 after 10 minutes. The slurry was aged for 1 hour. After aging, the pH of the slurry was adjusted to 7.5 by adding an aqueous sodium hydroxide solution or an aqueous sulfuric acid solution, and 70 g of sorbitan sesquiisostearate (5% by weight in terms of active components relative to titanium dioxide) was added, followed by aging for 15 minutes. After aging, 700 g of (C12-15) alkyl benzoate (50% by weight in terms of active components relative to titanium dioxide) was added, and the slurry was aged for 30 minutes. After aging, the pH value of the slurry was adjusted to 5.5 by adding an aqueous sodium hydroxide solution or an aqueous sulfuric acid solution, and then aged for 10 minutes. The slurry was filtered, washed, and dried at 85°C for 15 hours, and the dried product was pulverized using an Eck atomizer to produce a powder composition.

[0092] Comparative Example 1 A powder composition was produced in the same manner as in Example 1, except that steps 4 and 5 were omitted.

[0093] Comparative Example 2 A powder composition was produced in the same manner as in Example 1, except that step 5 was omitted.

[0094] Comparative Example 3 A powder composition was produced in the same manner as in Example 1, except that the amount of polyhydroxystearic acid added in step 4 was changed to 140 g (10% by weight in terms of the active ingredient relative to the titanium dioxide) and step 5 was omitted.

[0095] Comparative Example 4 A powder composition was produced in the same manner as in Example 1, except that step 4 was omitted and the amount of hexyl laurate added in step 5 was changed to 210 g (15% by weight in terms of active ingredient relative to titanium dioxide).

[0096] Comparative Example 5 A powder composition was produced in the same manner as in Example 1, except that the amount of polyhydroxystearic acid added in step 4 was changed to 770 g (55% by weight in terms of the active ingredient relative to the titanium dioxide).

[0097] Comparative Example 6 A powder composition was produced in the same manner as in Example 1, except that the amount of hexyl laurate added in step 5 was changed to 770 g (55% by weight in terms of the active ingredient relative to the titanium dioxide).

[0098] Comparative Example 7 Commercially available titanium oxide powder (manufactured by Teika Corporation: "MT-05"), average primary particle size: 10 nm, surface treatment agent: silicon (SiO ２ 5% by weight in terms of titanium dioxide), aluminum (Al ２ O ３ 500 g of titanium dioxide powder (10% by weight in terms of active ingredient) was placed in a mixer, and 65 g of dimethicone (15% by weight in terms of active ingredient relative to titanium dioxide) was added while stirring, followed by stirring for 15 minutes. The titanium dioxide powder thus obtained was pulverized using an Eck atomizer to produce a powder composition.

[0099] Comparative Example 8 Commercially available titanium oxide powder (manufactured by Teika Corporation: "MT-05" average primary particle diameter: 10 nm, surface treatment agent: silicon (SiO ２ 5% by weight in terms of titanium dioxide), aluminum (Al ２ O ３ 500 g of titanium dioxide powder (10% by weight in terms of active ingredient) was placed in a mixer, and 96 g of triethoxycaprylylsilane (22% by weight in terms of active ingredient relative to titanium dioxide) was added while stirring, and the mixture was stirred for 15 minutes. The titanium dioxide powder thus obtained was pulverized using an ECK atomizer to produce a powder composition.

[0100] <Dispersibility Test> The dispersibility of the produced powder compositions was evaluated as follows. (1) 27.9 g of medium was weighed into a 100 mL polypropylene cup measuring 50 mm in diameter, 43 mm in bottom diameter, and 76 mm in height. Here, dimethicone (KF-96L-1.5cs, manufactured by Shin-Etsu Chemical Co., Ltd.) was used as the medium for the powder compositions of Examples 32, 33, 35, and Comparative Example 7, while isododecane (Marukasol R, manufactured by Maruzen Petrochemical Co., Ltd.) was used as the medium for the powder compositions of the other Examples and Comparative Examples. (2) 2.1 g of the powder composition was weighed and added to the medium weighed in (1). (3) This was stirred for 10 minutes at a stirring speed of 500 rpm using a high-speed emulsifier / disperser ("Homodisper 2.5" manufactured by Primix Corporation, dispersion blade φ30 mm).

[0101] The dispersion prepared above was applied to a polypropylene film (Mitsui Chemicals Tohcello Co., Ltd.: plain OPP sheet #40) using an automatic bar coater equipped with a wire bar (No. 6) to form a coating film (film thickness: 10 μm). The total light transmittance of this coating film was measured using a spectrophotometer (Hitachi High-Technologies Corporation "U-4100" using an integrating sphere) under the following conditions: Scan speed: 300 nm / min, Sampling interval: 2 nm, Measurement wavelength: 250 to 700 nm. From the obtained transmittance curve, the transmittance T at a wavelength of 300 nm was calculated. ｔ３００ and transmittance T at a wavelength of 400 nm ｔ４００ The ratio was calculated using the following formula: Ratio = T ｔ３００ / T ｔ４００ The results are shown in Table 1. If the total light transmittance at a wavelength of 300 nm was 10% or less and the value of (300 nm transmittance) / (400 nm transmittance) was 0.2 or less, the evaluation was "Good", and if at least one of the conditions was not satisfied, the evaluation was "Poor".

[0102]

[0103] As shown in Table 1, Examples 1 to 37 have a low 300 nm transmittance of 10% or less, even with weak dispersion as in the dispersibility test, and have excellent UV-shielding ability. Furthermore, Examples 1 to 37 have a small (300 nm transmittance) / (400 nm transmittance) of 0.2 or less, so they have low 300 nm transmittance, high UV-shielding ability, and high 400 nm transmittance, resulting in high transparency. Therefore, it can be seen that Examples 1 to 37 achieve both high UV-shielding ability and high transparency. Comparative Examples 1 to 8 have a 300 nm transmittance of more than 10%, and therefore have inferior UV-shielding ability compared to the Examples. Furthermore, Comparative Examples 1 to 8 have high 300 nm transmittance, so the value of (300 nm transmittance) / (400 nm transmittance) is also high, and therefore UV-shielding ability and transparency are not compatible.

[0104] <Production of W / O Emulsion Cosmetic> Example 38 30.8 g of the mixture of oil phase raw materials shown below was placed in a 150 mL polypropylene cup, and 7.0 g of the powder composition of Example 1 was added while stirring at 500 rpm using a high-speed emulsifier / disperser "T.K. Robomix" manufactured by Primix Corporation. The stirring speed was then increased to 1500 rpm, and the mixture was stirred for 10 minutes. Thereafter, while continuing stirring, 32.2 g of the mixture of water phase raw materials shown below was added, and the mixture was stirred at 1500 rpm for 5 minutes, thereby producing the emulsion cosmetic of Example 38.

[0105] Example 39 Using the powder composition of Example 14, an emulsion cosmetic of Example 39 was prepared in the same manner as in Example 38.

[0106] Example 40 Using the powder composition of Example 17, an emulsion cosmetic of Example 40 was prepared in the same manner as in Example 38.

[0107] Example 41 Using the powder composition of Example 25, an emulsion cosmetic of Example 41 was prepared in the same manner as in Example 38.

[0108] Example 42 Using the powder composition of Example 32, an emulsion cosmetic of Example 42 was prepared in the same manner as in Example 38.

[0109] Comparative Example 9 Using the powder composition of Comparative Example 1, an emulsion cosmetic of Comparative Example 9 was prepared in the same manner as in Example 38.

[0110] Comparative Example 10 Using the powder composition of Comparative Example 4, an emulsion cosmetic of Comparative Example 10 was prepared in the same manner as in Example 38.

[0111] Comparative Example 11 Using the powder composition of Comparative Example 7, an emulsion cosmetic of Comparative Example 11 was prepared in the same manner as in Example 38.

[0112] The oil phase raw materials for the W / O emulsion cosmetic were as follows: 23.8 g of isododecane: "Marukasol R" manufactured by Maruzen Petrochemical Co., Ltd. 3.5 g of liquid paraffin: "Moresco White P-70" manufactured by MORESCO Corporation 3.5 g of lauryl PEG-9 polydimethylsiloxyethyl dimethicone: "KF-6038" manufactured by Shin-Etsu Chemical Co., Ltd.

[0113] The water phase ingredients of the W / O emulsion cosmetic were as follows: ion-exchanged water 22.4 g 1,3-butylene glycol 9.8 g

[0114] <Evaluation of Cosmetics (Transparency)> Immediately after applying 0.05 g of each of the emulsion cosmetics of Examples 38 to 42 and Comparative Examples 9 to 11 to the skin on the forearms of 10 panelists, the whiteness and transparency were evaluated visually under sunlight while changing the viewing angle. In particular, the blueness was observed in areas where the veins were visible through the skin. After spreading, the cosmetics were left to stand for 5 minutes, and then dried, after which the transparency was evaluated. Each panelist cast one vote if the transparency of each emulsion cosmetic was higher than that of Comparative Example 9, using Comparative Example 9 as the standard. The results are shown in Table 2.

[0115] When comparing the results immediately after spreading and after drying, more than eight people (10 people) voted that Examples 38 to 42 had a higher transparency, and Examples 38 to 42 were rated as having a higher transparency than any of Comparative Examples 9 to 11.

[0116] <Evaluation of Cosmetics (Transmittance)> 1.0 g of the emulsion cosmetics of Examples 38 to 42 or Comparative Examples 9 to 11 was applied to a polypropylene film (Mitsui Chemicals Tohcello, Inc.: plain OPP sheet #40) using an automatic bar coater equipped with a wire bar (No. #6) to form a coating film (film thickness: 10 μm). The total light transmittance of this coating film was measured using a spectrophotometer (Hitachi High-Technologies Corporation, "U-4100" using an integrating sphere) under the following conditions, and the transmittance at 300 nm (ultraviolet ray shielding ability), 400 nm (transparency), and 450 nm (transparency) was read. The measurement conditions were as follows: Scan speed: 300 nm / min Sampling interval: 2 nm Measurement wavelength: 250 to 700 nm The results are shown in Table 2.

[0117]

[0118] Examples 38 to 42 and Comparative Examples 9 to 11 exhibited high ultraviolet shielding ability due to low transmittance at 300 nm (ultraviolet shielding ability). Examples 38 to 42 exhibited high transparency due to higher transmittance at 400 nm (transparency) and 450 nm (transparency) than Comparative Example 11 (standard). Comparative Examples 10 to 11 exhibited transmittance at 400 nm (transparency) and 450 nm (transparency) equivalent to Comparative Example 9 (standard), so no improvement in transparency was observed.

[0119] <Production of O / W Emulsion Cosmetic> Example 43 30.4 g of a mixture of oil phase ingredients shown in Table 3 (excluding the powder composition of Example 1) was placed in a 200 mL polypropylene cup, and 9.6 g of the powder composition of Example 1 was added while stirring at 500 rpm using a high-speed emulsifier / disperser "T.K. Robomix" manufactured by Primix Corporation. The stirring speed was then increased to 5,000 rpm, and stirring was continued for 5 minutes. Next, 40 g of the mixture of aqueous phase ingredients shown in Table 3 was weighed into a 150 mL polypropylene cup, and while heating, the mixture was stirred using a high-speed emulsifier / disperser "T.K. Robomix" manufactured by Primix Corporation until the PEG-100 hydrogenated castor oil was completely dissolved. Subsequently, while stirring the aqueous phase ingredients with a propeller, the oil phase ingredients were slowly added, and the mixture was stirred for 3 minutes at 1,500 rpm using a homomixer, to prepare the emulsion cosmetic of Example 43.

[0120]

[0121] Examples 44 to 46, Comparative Examples 12 to 14 Emulsion cosmetics of Examples 44 to 46 and Comparative Examples 12 to 14 were prepared in the same manner as in Example 43, except that the powder composition of Example 1 was changed to the powder composition shown in Table 4.

[0122] <Evaluation of Emulsified State> The appearance of the emulsion cosmetics of Examples 43 to 46 and Comparative Examples 12 to 14 was checked immediately after preparation, and those that were able to be emulsified were rated as "○", and those that were not able to be emulsified were rated as "×". Furthermore, the emulsion cosmetics of Examples 43 to 46 and Comparative Examples 12 to 13 that were able to be emulsified immediately after preparation were stored for two months in an insulated cabinet set at 50°C, and then their appearance (separation of the oil and water phases, presence or absence of aggregates) was checked, and those that had not changed in emulsified state from immediately after preparation were rated as "○", and those that had changed in state were rated as "×". These evaluation results are shown in Table 4.

[0123]

[0124] In Examples 43 to 46, an emulsified state was formed immediately after preparation, and a uniform emulsified state was maintained even after two months of storage at 50° C. In Comparative Examples 12 and 13, an emulsified state was formed immediately after preparation, but a uniform emulsified state could not be maintained after two months of storage at 50° C. In Comparative Example 14, an emulsified state could not be formed immediately after preparation, resulting in poor dispersibility.

[0125] As described above, the powder composition of the present invention has extremely high dispersibility, and therefore, when incorporated into an internal oil phase, it causes little aggregation, making it possible to provide a highly stable O / W emulsion cosmetic. Furthermore, it has been confirmed that this high dispersibility is not limited to the formulation type, and contributes to the development of high UV protection effects and transparency, not only in O / W types but also in W / O types, and is also effective in reducing the energy and time required for dispersion.

[0126] The embodiments and examples disclosed above should be considered to be illustrative in all respects and not restrictive. The scope of the present invention is defined not by the above embodiments and examples but by the claims, and includes all modifications and variations within the meaning and scope equivalent to the claims.

Claims

1. Titanium oxide powder as the powder to be treated, At least one hydrophobic treatment agent selected from the group consisting of fatty acids, silicones, and silane coupling agents; A surfactant, and an oil agent, The content of the surfactant is 0.1% or more and 50% or less of the weight of the powder to be treated, A powder composition, wherein the content of the oil is 0.1% or more and 50% or less of the weight of the powder to be treated.

2. 2. The powder composition according to claim 1, wherein the content of the hydrophobic treatment agent is 7% or more and 30% or less of the weight of the powder to be treated.

3. 3. The powder composition according to claim 1, wherein the total light transmittance at a wavelength of 300 nm is 10% or less, and the value of (transmittance at 300 nm) / (transmittance at 400 nm) is 0.2 or less.

4. A cosmetic comprising the powder composition according to claim 1.

5. an alkalinization step of adding an alkali metal hydroxide to an aqueous dispersion of hydrous titanium oxide to obtain an alkali metal titanate; an acidification step of adding hydrochloric acid to the aqueous dispersion of the alkali metal titanate to obtain titanium oxide containing rutile crystals; A method for producing a powder composition, comprising a mixing step of mixing the titanium oxide obtained in the acidification step with at least one hydrophobic treatment agent selected from the group consisting of fatty acids, silicones, and silane coupling agents, a surfactant, and an oil agent.

6. The method for producing a powder composition according to claim 5 , wherein the mixing step includes mixing titanium oxide and a hydrophobic treatment agent, and then adding a surfactant and an oil agent.

7. 6. The method for producing a powder composition according to claim 5, wherein the mixing step is a step of mixing at least a metal oxide or a metal hydroxide, the hydrophobic treatment agent, a surfactant, and an oil agent with the titanium oxide obtained in the acidifying step.

8. 8. The method for producing a powder composition according to claim 7, wherein the mixing step includes mixing titanium oxide, a metal oxide or metal hydroxide, and the hydrophobization treatment agent, and then adding a surfactant and an oil agent.

9. 8. The method for producing a powder composition according to claim 7, wherein the mixing step includes mixing titanium oxide with a metal oxide or a metal hydroxide, and then adding the hydrophobic treatment agent, a surfactant, and an oil agent.