Barium sulfate-containing spherical particles, and tactile sensation improving agent and cosmetic using same

Abstract

Provided is a cosmetic which exhibits excellent adhesion to the skin and excellent spreading on the skin when applied to a sponge, puff, or the like, while being suppressed in stickiness and having an excellent feeling of use. The present invention pertains to spherical barium sulfate-containing particles characterized in that the spherical barium sulfate-containing particles are surface-treated with a fatty acid in an amount of 1-10% by mass relative to the spherical barium sulfate-containing particles before the surface treatment, and in that a molded article obtained by molding the spherical barium sulfate-containing particles has a penetration load of 100 mN or more.

Description

Technical Field

[0001] The present invention relates to spherical particles containing barium sulfate and a feel improver and cosmetics using the same. Background Art

[0002] Cosmetics are sold in various forms, such as solid and liquid, to meet the desired effects and consumer preferences. Among them, solid powder cosmetics are required to have a good feel when applied with a sponge or puff, such as good adhesion and spreadability on the skin. To achieve a good feel, cosmetics need to have good smoothness on the skin, and spherical particles are added to cosmetics to improve the tactile feel, such as smoothness and spreadability. Plastic microbeads are used as spherical particles, but in recent years, due to the increasing problem of marine pollution caused by plastics, the use of plastic microbeads in cosmetics has been banned in major countries (particularly the EU), and the demand for alternative raw materials is increasing. As a cosmetic that does not use plastic microbeads, an oily solid cosmetic is disclosed in which synthetic mica is added to an oily solid cosmetic (see Patent Document 1). In addition, spherical barium sulfate is being studied as an alternative material to plastic microbeads. As a spherical barium sulfate used in cosmetic applications, a spherical barium sulfate composite powder with characteristics such as high strength and excellent tactile feel is disclosed (see Patent Document 2).

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Laid-Open No. 2003-300816

[0006] Patent Document 2: Japanese Patent Application Laid-Open No. 2018-140921 Summary of the Invention

[0007] Problems to be solved by the invention

[0008] As mentioned above, solid powder cosmetics are formulated with spherical particles to enhance the feel of the product. However, since spherical particles themselves lack solidifying power, they lack the solidifying power necessary for application with a sponge or puff, leading to cosmetic loss of shape. Consequently, solid powder cosmetics use solidifying agents such as synthetic waxes. However, these agents can degrade the feel of the product due to, for example, a sticky feeling.

[0009] In view of the above-mentioned situation, an object of the present invention is to provide a cosmetic product that has excellent adhesion and spreadability on the skin when applied with a sponge, puff, etc., and has a suppressed sticky feeling and an excellent feel during use.

[0010] Solutions for solving problems

[0011] The present inventors have been researching cosmetics that exhibit excellent absorption and spreadability during use, while also suppressing a sticky feeling and providing an excellent feel during use. They have focused on particles containing barium sulfate as particles for use in cosmetics. They have discovered that when barium sulfate-containing particles surface-treated with a fatty acid at a predetermined ratio, such that the needle penetration load of the molded article reaches a predetermined value or higher, are incorporated into a cosmetic, a cosmetic product exhibits excellent absorption and spreadability during use, while suppressing a sticky feeling and providing an excellent feel during use can be obtained, leading to the completion of the present invention.

[0012] That is, the present invention is as follows.

[0013] [1] A spherical particle containing barium sulfate, characterized in that the spherical particle containing barium sulfate is surface-treated with 1 to 10% by mass of a fatty acid relative to the spherical particle containing barium sulfate before the surface treatment, and the needle penetration load of the molded product formed by molding the spherical particle containing barium sulfate is 100 mN or more.

[0014] [2] The spherical particles containing barium sulfate according to [1] are characterized in that the spherical particles containing barium sulfate are composite particles of barium sulfate and silicon dioxide.

[0015] [3] A touch improver, characterized in that it contains the spherical particles containing barium sulfate described in [1] or [2].

[0016] [4] A cosmetic comprising the touch improver described in [3].

[0017] Effects of the Invention

[0018] By incorporating the barium sulfate-containing spherical particles of the present invention into cosmetics, it is possible to achieve excellent adhesion during use without using plastic microbeads, excellent spreading on the skin, and an excellent feel with reduced stickiness. DETAILED DESCRIPTION

[0019] Hereinafter, preferred embodiments of the present invention will be described in detail. However, the present invention is not limited to the following description and can be appropriately modified and used within the scope of the present invention.

[0020] 1. Spherical particles containing barium sulfate

[0021] The barium sulfate-containing spherical particles of the present invention are surface-treated with 1 to 10% by mass of a fatty acid relative to the barium sulfate-containing spherical particles before the surface treatment.

[0022] By treating the surface with fatty acids, the affinity with resin components and the like that are components of cosmetics is improved, making it easier to disperse the polymer uniformly in the cosmetics.

[0023] In the present invention, spherical particles do not mean completely spherical, but refer to particles having a sphericity of 1.5 or less. The sphericity of spherical particles is preferably 1.3 or less, more preferably 1.1 or less.

[0024] Examples of the fatty acids include fatty acids with 12 to 24 carbon atoms, such as lauric acid, myristic acid, palmitic acid, stearic acid, behenic acid, and eicosapentaenoic acid. One or more of these can be used. Among these, fatty acids with 14 to 20 carbon atoms, such as stearic acid, palmitic acid, and myristic acid, are preferred. These fatty acids have relatively high melting points, making them compatible and uniformly dispersed with the oil added as a binder when mixing cosmetic ingredients. The resulting solid cosmetic provides an excellent feel when applied with a puff. More preferred fatty acids are fatty acids with 14 to 18 carbon atoms, such as stearic acid and palmitic acid.

[0025] The barium sulfate-containing spherical particles of the present invention are surface-treated with 1 to 12% by mass of fatty acid relative to the mass of the barium sulfate-containing spherical particles before surface treatment. Preferably, the barium sulfate-containing spherical particles are surface-treated with 1 to 7% by mass of fatty acid relative to the mass of the barium sulfate-containing spherical particles before surface treatment, and more preferably, the barium sulfate-containing spherical particles are surface-treated with 2.5 to 5% by mass of fatty acid.

[0026] The barium sulfate-containing spherical particles of the present invention are characterized in that the needle penetration load of the molded article formed from the barium sulfate-containing spherical particles is 100 mN or greater. Because the barium sulfate-containing spherical particles of the present invention have a curing power, the use of curing agents such as synthetic wax for solidifying cosmetics can be suppressed. Consequently, cosmetics can be made that are easy to apply and spread well on the skin when applied with a sponge, puff, or the like, while also having a suppressed sticky feel and providing an excellent feel. The needle penetration load of the molded article formed from the barium sulfate-containing spherical particles is preferably 200 mN or greater, and more preferably 500 mN or greater.

[0027] The penetration load of a molded article formed by molding spherical particles containing barium sulfate can be measured by the method described in the examples below.

[0028] The average particle size of the barium sulfate-containing spherical particles of the present invention is preferably 2.5 to 15 μm. When used in cosmetics, particles with such an average particle size provide a more excellent feel during use. It is more preferably 3.0 to 10 μm, and even more preferably 3.5 to 8 μm.

[0029] The average particle size of the spherical particles containing barium sulfate can be measured by the method described in the Examples below.

[0030] The barium sulfate-containing spherical particles of the present invention may be obtained by surface-treating particles consisting solely of barium sulfate with a fatty acid, or by surface-treating a mixture of barium sulfate and a component other than barium sulfate, or by surface-treating composite particles with a fatty acid. Preferably, the composite particles of barium sulfate and silicon dioxide are surface-treated with a fatty acid. Since silicon dioxide acts as a binder during particle formation, a composite of barium sulfate and silicon dioxide facilitates the production of spherical particles that are difficult to disintegrate.

[0031] When the barium sulfate-containing spherical particles of the present invention are composite particles of barium sulfate and silicon dioxide, the silicon dioxide is preferably composited with the barium sulfate at a ratio of 1 to 45% by mass relative to 100% by mass of the barium sulfate, more preferably 3 to 30% by mass, and even more preferably 5 to 20% by mass.

[0032] 2. Method for producing spherical particles containing barium sulfate

[0033] The barium sulfate-containing spherical particles of the present invention can be produced by a production method comprising the following steps: a first step of obtaining barium sulfate-containing spherical particles; and a second step of surface-treating the obtained barium sulfate-containing spherical particles with a fatty acid.

[0034] In the first step, when obtaining particles consisting solely of barium sulfate as barium sulfate-containing spherical particles, the method is not particularly limited. For example, a method of reacting barium sulfide with sulfuric acid can be used. The reaction of barium sulfide with sulfuric acid can be carried out with reference to Japanese Patent Application Laid-Open No. 2018-140921.

[0035] Furthermore, after the first step, a step of washing the barium sulfate obtained by the reaction of barium sulfide and sulfuric acid with an aqueous solution of a sulfate salt of an element of Group 1 or Group 2 of the periodic table or sulfuric acid may be performed.

[0036] In the first step, when composite particles of barium sulfate and silicon dioxide are obtained as spherical particles containing barium sulfate, the method for producing the composite particles is not particularly limited, and a production method comprising the following steps can be used: step (1) preparing a slurry containing particles of barium sulfate and silicon dioxide sol; step (2) spray-drying the slurry; and step (3) calcining the dried product obtained in step (2).

[0037] Each step (1) to (3) can be performed with reference to Japanese Patent Application Laid-Open No. 2018-140921.

[0038] Alternatively, instead of the above step (2), the following steps (2-1), (2-2), and (2-3) may be performed:

[0039] In step (2-1), a mixture satisfying any of the following conditions is obtained when a portion of the slurry obtained in step (1) is spray-dried and calcined at 800 to 1100° C. and subjected to a purity test for “hydrochloric acid soluble matter and soluble barium salt” in the standard for “barium sulfate” in “Standards for Quasi-drug Ingredients 2021”:

[0040] (a) The hydrochloric acid soluble matter is 15 mg or less and the absorbance of the test solution after the "soluble barium salt" test is less than 0.03, or

[0041] (b) The hydrochloric acid-soluble matter is 14 mg or less, and the absorbance of the test solution after the "soluble barium salt" test is 0.03 or more;

[0042] Step (2-2), when the mixture obtained in step (2-1) meets the conditions of step (b), adding a salt of an element of Group 1 or Group 2 of the periodic table to the mixture in an amount of 0.05 to 0.40% by mass relative to the weight of the raw material barium sulfate;

[0043] In step (2-3), the mixture to which the salt of the periodic table Group 1 or Group 2 element is added or not added in step (2-2) is spray-dried to obtain a dried product.

[0044] By performing these steps (2-1) to (2-3) to produce composite particles of barium sulfate and silicon dioxide, composite particles that meet the requirements of "hydrochloric acid soluble matter and soluble barium salt" in the standard of "barium sulfate" in the "Quasi-drug Raw Material Standards 2021" can be easily obtained.

[0045] Steps (2-1) to (2-3) can be performed in the same manner as the third to fifth steps of the method for producing spherical composite particles of barium sulfate and silicon dioxide described in Japanese Patent Application No. 2022-043020.

[0046] In the second step, the method for surface-treating the spherical particles containing barium sulfate with a fatty acid is not particularly limited. For example, a method in which the spherical particles containing barium sulfate are mixed with the fatty acid in a high-speed mixer and uniformly adhered to the particle surface, a method in which the spherical composite particles are dispersed in a solvent and then the fatty acid is added, etc. When the spherical particles containing barium sulfate and the fatty acid are mixed in a high-speed mixer, the mixture is preferably heated at a temperature not lower than the melting point of the fatty acid used.

[0047] 3. Touch improvers, cosmetics

[0048] The present invention also provides a feel-improving agent comprising the barium sulfate-containing spherical particles of the present invention. By adding the barium sulfate-containing spherical particles of the present invention to cosmetics, the feel of the cosmetic, such as how it spreads across the skin, can be improved when applied with a sponge, puff, or the like. Furthermore, the barium sulfate-containing spherical particles of the present invention have a curing power. When using these particles to produce solid cosmetics, the amount of curing agents such as synthetic waxes used can be reduced, resulting in cosmetics with a less sticky feel and excellent feel.

[0049] The feel modifier of the present invention may contain other components as long as it comprises the barium sulfate-containing spherical particles of the present invention. However, the proportion of other components is preferably 20% by mass or less of the total feel modifier, more preferably 10% by mass or less, and even more preferably 5% by mass or less.

[0050] The present invention also relates to a cosmetic comprising the feel modifier of the present invention. Since the feel modifier of the present invention can improve the feel of solid cosmetics, the cosmetic of the present invention is preferably a solid cosmetic.

[0051] The feel modifier of the present invention is preferably blended into the cosmetic product at a concentration of 1 to 50% by mass, more preferably 2 to 30% by mass, of the total cosmetic product. Below this range, the effect of the feel modifier is too weak, while above this range reduces the amount of other ingredients added, making it difficult to impart other functions.

[0052] By incorporating the feel modifier of the present invention into cosmetics, cosmetics with a pleasant feel, reduced skin imperfections such as spots, and excellent storage stability can be obtained. Furthermore, the inclusion of spherical composite particles, which have enhanced drop resistance and suppressed sedimentation, resulting in improved dispersibility, can provide an SPF enhancement effect.

[0053] In addition to the above-mentioned ingredients, the cosmetics of the present invention may also contain one or more ingredients commonly used in cosmetics and quasi-drugs, such as powdered ingredients, non-polar oils, liquid oils, solid oils, natural waxes, higher fatty acids, higher alcohols, surfactants, thickeners, UV shielding agents, sugars, moisturizers, amino acids, organic amines, alkylene oxide derivatives, metal ion chelating agents, antioxidants, antioxidant aids, and other ingredients that may be added. Examples of ingredients that may be added are listed below.

[0054] Examples of the powder component include: inorganic powders (e.g., talc, kaolin, mica, sericite, muscovite, phlogopite, synthetic mica, red mica, biotite, vermiculite, magnesium carbonate, calcium carbonate, aluminum silicate, barium silicate, barium sulfate, etc.); organic powders (e.g., polyamide resin powder, polyethylene powder, polymethyl methacrylate powder, polystyrene powder, etc.); inorganic white pigments (e.g., titanium oxide, zinc oxide, etc.); inorganic red pigments (e.g., iron titanate, etc.); inorganic violet pigments (e.g., manganese violet, cobalt violet, etc.); inorganic green pigments (e.g., chromium oxide, chromium hydroxide, cobalt titanate, etc.); inorganic blue pigments (e.g., , ultramarine, cobalt blue, etc.); pearlescent pigments (for example, titanium oxide-coated mica, titanium oxide-coated bismuth oxychloride, etc.); metal powder pigments (for example, aluminum powder, copper powder, etc.); organic pigments such as zirconium, barium or aluminum lakes (for example, organic pigments such as Red No. 201 to 205, Orange No. 203, Orange No. 204, Yellow No. 205, Yellow No. 401 and Blue No. 404, Red No. 3, Red No. 104, Red No. 106, Red No. 227, Orange No. 205, Yellow No. 4, Yellow No. 5, Yellow No. 202, Yellow No. 203, Green No. 3 and Blue No. 1, etc.); natural pigments (for example, chlorophyll, β-carotene, etc.), etc.

[0055] Examples of the nonpolar oil include hydrocarbon oils such as silicone oil, liquid paraffin, squalane, squalene, paraffin, isohexadecane, isododecane, α-olefin oligomers, polybutene, and polyisobutene.

[0056] Examples of the silicone oil include chain silicone oils such as dimethylpolysiloxane, methylphenylpolysiloxane, octylmethicone, diphenylsiloxyphenyltrimethicone, and methylhydrogenpolysiloxane; and cyclic silicone oils such as octamethylcyclotetrasiloxane.

[0057] Examples of the ester oil include cetyl octanoate, ethyl oleate, isopropyl myristate, isopropyl palmitate, myristyl myristate, cetyl palmitate, 2-ethylhexyl palmitate, octyldodecyl myristate, isopropyl isostearate, and propylene glycol isostearate.

[0058] Examples of the liquid oil include avocado oil, camellia oil, turtle oil, macadamia nut oil, corn oil, mink oil, olive oil, rapeseed oil, egg yolk oil, sesame oil, almond oil, and wheat germ oil.

[0059] Examples of the solid oils and fats include cocoa butter, coconut oil, horse fat, solidified coconut oil, palm oil, beef tallow, sheep tallow, solidified beef tallow, and palm kernel oil.

[0060] Examples of the natural waxes include beeswax, candelilla wax, cotton wax, carnauba wax, bayberry wax, insect wax, spermaceti wax, montan wax, bran wax, lanolin, kapok wax, acetylated lanolin, lanolin oil, and cane wax.

[0061] Examples of higher fatty acids include lauric acid, myristic acid, palmitic acid, stearic acid, behenic acid, oleic acid, undecylenic acid, tall oil acid, isostearic acid, linoleic acid, linolenic acid, eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA).

[0062] Examples of the higher alcohol include straight-chain alcohols (eg, lauryl alcohol, cetyl alcohol, stearyl alcohol, etc.); and branched-chain alcohols (eg, monostearyl glyceryl ether (batyl alcohol), 2-decyltetradecyl alcohol, etc.).

[0063] Examples of the surfactant include nonionic surfactants, anionic surfactants, cationic surfactants, and amphoteric surfactants, and generally known surfactants can be used.

[0064] Examples of thickeners include aqueous gum arabic, carrageenan, karaya gum, and tragacanth gum; acrylic polymers such as sodium polyacrylate, sodium acrylate grafted starch, carbomer, copolymers and / or cross-linked polymers of acrylic acid and alkyl (meth)acrylates, polyacrylamide, copolymers of alkyl acrylates and / or acrylamide and acryloyldimethyl taurate; locust bean gum and guar gum; and oily organic modified clay minerals obtained by modifying montmorillonite group clay minerals such as bentonite and hectorite, clay minerals such as vermiculite and bentonite with quaternary ammonium compounds such as alkyltrimethylammonium chloride; fumed silica, hydrophobized fumed silica, polysaccharide fatty acid esters, 12-hydroxystearic acid, and highly polymerized methyl polysiloxanes. One or more of these can be used.

[0065] Examples of UV shielding agents include, for example, inorganic UV scattering agents, including fine-particle titanium oxide, fine-particle zinc oxide, and fine-particle iron oxide. Examples include those supported on extender pigment powders such as mica and talc, those supported on the surface of spherical organic powders such as polymethyl methacrylate or spherical inorganic powders such as silica, those with iron or other metals introduced into lattice defects of fine-particle metal oxides, and those treated with commonly known surface treatment agents such as fluorine compounds and organosilicon compounds. Examples of organic UV absorbers include 2-hydroxy-4-methoxybenzophenone and 2,4,6-triphenylamino-p-(carbon-2'-ethylhexyl-1'-oxy)-1,3,5-triazine, and one or more of these can be used.

[0066] Examples of the sugar include known tri- to octose sugars; deoxysugars (e.g., 2-deoxy-D-ribose, 6-deoxy-L-galactose, 6-deoxy-L-mannose, etc.); amino sugars (e.g., D-glucosamine, D-galactosamine, etc.); monosaccharides such as uronic acid (e.g., D-glucuronic acid, D-mannuronic acid, etc.); sucrose, gentiotriose, umbelliferose, lactose, plantaginose, isolysaccharides, α,α-trehalose, raffinose, lychnosyl-D-arabinitol (umbilicin), oligosaccharides such as stachyose verbascoses, and the like.

[0067] Examples of moisturizing agents include polyethylene glycol, propylene glycol, glycerin, 1,3-butylene glycol, xylitol, sorbitol, maltitol, chondroitin sulfate, hyaluronic acid, sulfated mucopolysaccharide, trichosanthes acid (caronic acid), atelocollagen, sodium lactate, bile acid salts, dl-pyrrolidonecarboxylate, short-chain soluble collagen, diglycerol (EO) PO adduct, roxburghii fruit extract, achillea millefolium extract, and sweet clover extract.

[0068] Examples of amino acids include neutral amino acids (e.g., threonine, cysteine, etc.), basic amino acids (e.g., hydroxylysine, etc.), and amino acid derivatives include sodium acyl sarcosinate (sodium lauroyl sarcosinate), acyl glutamate, sodium acyl β-alanine, glutathione, and pyrrolidone carboxylic acid.

[0069] Examples of the organic amine include monoethanolamine, diethanolamine, triethanolamine, morpholine, triisopropanolamine, 2-amino-2-methyl-1,3-propanediol, and 2-amino-2-methyl-1-propanol.

[0070] Examples of the alkylene oxide derivatives include polyoxyethylene polyoxypropylene dimethyl ethers having various lengths of oxyethylene chains and oxypropylene chains.

[0071] Examples of the metal ion chelating agent include 1-hydroxyethane-1,1-diphosphonic acid, 1-hydroxyethane-1,1-diphosphonic acid tetrasodium salt, disodium edetate, trisodium edetate, tetrasodium edetate, and sodium citrate.

[0072] Examples of the antioxidant include tocopherol, vitamin C, butylated hydroxytoluene, butylated hydroxyanisole, sodium metabisulfite, sodium ascorbate, and ascorbyl dipalmitate.

[0073] Examples of the antioxidant aid include phosphoric acid, citric acid, ascorbic acid, maleic acid, malonic acid, succinic acid, fumaric acid, cephalin, hexametaphosphate, phytic acid, and ethylenediaminetetraacetic acid.

[0074] Examples of other ingredients that may be added include preservatives, whitening agents, blood circulation promoters, various extracts, activators, and sebum secretion inhibitors.

[0075] Example

[0076] The present invention will be described in more detail below with reference to specific examples, but the present invention is not limited to these examples. Unless otherwise specified, "%" and "wt%" mean "weight % (mass %)."

[0077] Example 1 (Preparation of Spherical Barium Sulfate-Silicon Dioxide Composite Powder)

[0078] (First process)

[0079] Barium sulfate (raw material) with an average particle size of 0.05 μm (pigment pH 8.5 when dried) was prepared by reacting barium sulfide with sulfuric acid. This was then washed with water to form a slurry, and pure water was added to adjust the slurry concentration to 135 g / L. Sodium sulfate (anhydrous) (Kishida Chemical, 99%) was added and dissolved in this raw barium sulfate slurry at a concentration of 0.8% relative to the barium sulfate. The mixture was stirred for 30 minutes, filtered, and washed with water until the conductivity reached 40 μm / S or less. The washed solids were re-slurried in pure water to a slurry concentration of 380 g / L. Silica sol (Snowtex ST-30, Nissan Chemical) was added and mixed into this slurry at a weight ratio of BaSO₄ to SiO₂ of 93:7.

[0080] A portion of the obtained mixture was spray-dried and calcined at 900°C for 2 hours to obtain a powder. The results of the "barium sulfate" test specified in the "Barium sulfate" standard of the "Quasi-drug Raw Material Standard 2021" showed that the hydrochloric acid-soluble matter was less than 15 mg (8.0 mg), and the absorbance of the test solution after the "soluble barium salt" test was less than 0.03 (0.004).

[0081] Therefore, the mixture was directly spray-dried using a micromist spray dryer (MDL-050CM, manufactured by GF), and the resulting dried product was calcined at 900°C for 2 hours to produce 3.5 μm spherical composite particles of barium sulfate and silicon dioxide. The resulting particles had a sphericity of 1.03.

[0082] (Second process)

[0083] 8 kg of the spherical composite particles of barium sulfate and silicon dioxide obtained in the first step were placed in a 20 L high-speed mixer. Subsequently, 280 g of stearic acid was added as a surface treatment agent, and the mixture was stirred and mixed at 1300 rpm. The rotation was stopped 5 minutes after the temperature of the mixed layer reached 100°C, which is equal to or higher than the melting point of the fatty acid. This yielded a powder 1 of fatty acid-treated spherical particles.

[0084] Examples 2 to 7

[0085] Powders 2 to 7 of fatty acid-treated spherical particles were obtained in the same manner as in Example 1 except that the type and amount of the fatty acid used to surface-treat the spherical composite particles of barium sulfate and silica were changed as shown in Table 1.

[0086] [Table 1]

[0087]

[0088] Comparative Example 1

[0089] The spherical composite particles of barium sulfate and silicon dioxide obtained in the first step of Example 1 were designated as Comparative Powder 1.

[0090] Comparative Example 2

[0091] 10 g of the spherical composite particles of barium sulfate and silicon dioxide obtained in the first step of Example 1 and 0.35 g of stearic acid were placed in a bag, and the bag was shaken for 5 minutes to obtain a powder which was a mixture of stearic acid and the spherical composite particles, referred to as Comparative Powder 2.

[0092] Comparative Example 3

[0093] 8 kg of the spherical composite particles of barium sulfate and silicon dioxide obtained in the first step of Example 1 were placed in a 20 L high-speed mixer. Silicone (KF-9901 manufactured by Shin-Etsu Chemical Co., Ltd.) was then added as a surface treatment agent and stirred at 1300 rpm. The mixture was then heated at 120°C overnight to obtain a powder designated as Comparative Powder 3.

[0094] Comparative Example 4

[0095] Polymethyl methacrylate having an average particle size of 8 μm (manufactured by Matsumoto Oil & Pharmaceutical Co., Ltd.: Matsumoto microsphere M-100) was used as comparative powder 4.

[0096] Comparative Example 5

[0097] Spherical silica having an average particle size of 5 μm (manufactured by JGC Catalysts & Chemicals Co., Ltd.: SATINIER M5) was used as comparative powder 5.

[0098] Comparative Example 6

[0099] Comparative Powder 6 was prepared by subjecting the same method as in Example 1 to a process for treating spherical particles with fatty acid, except that the treatment amount of stearic acid was changed to 13 wt %.

[0100] Comparative Example 7

[0101] Comparative Powder 7 was a powder of fatty acid-treated spherical particles obtained in the same manner as in Example 1 except that the spherical silica of Comparative Example 5 was treated with 3.5 wt % of stearic acid.

[0102] [Powder Evaluation]

[0103] The penetration load of the powders 1 to 7 obtained in Examples 1 to 7 and the comparative powders 1 to 7 obtained in Comparative Examples 1 to 7 were measured and the water repellency and touch were evaluated by the following methods.

[0104] <Penetration load>

[0105] 3 g of the ground powder was placed in a 25 mm φ, 4 mm thick circular aluminum pan. A hand press was used to apply a load of 6 MPa for 5 seconds to produce a compact. The load when a 1 mm diameter needle was inserted 1 mm into the compact was measured three times using a rheometer, and the average value was calculated.

[0106] <Water repellency evaluation>

[0107] 1 g of each powder was lightly placed on the surface of 100 ml of pure water, stirred at 60 rpm using a magnetic stirrer for 1 minute, and then the water repellency was visually evaluated according to the following criteria.

[0108] ○: Almost all the powder was floating on the water surface.

[0109] Δ: More than half of the powder was in a state of floating on the water surface, but a part of the powder was in a state of being compatible with water.

[0110] ×: Most of the powder is compatible with water.

[0111] <Tactile evaluation>

[0112] A panel of 10 people applied each sample, obtained by placing it in a rectangular aluminum container using a manual press, to the skin using a puff. The puffs were then evaluated on a scale of 5 (good) to 1 (poor) based on the feel of the product (moisture, no stickiness, and evenness without unevenness). The evaluation was based on the average of the five scores.

[0113] [Table 2]

[0114]

[0115] ※Comparative Examples 4, 5, and 7 did not spread when applied with a puff and could not be applied to the skin.

[0116] The results shown in Table 2 show that Examples 1-7, in which the spherical barium sulfate-silica composite powder was surface-treated with fatty acids, had high penetration loads and a good feel. In contrast, Comparative Examples 1-3 had low penetration loads, so when applied with a puff, an amount equal to or exceeding the amount suitable for application to the skin adhered, resulting in poor skin-friendliness and a deteriorated feel. Furthermore, in Comparative Example 2, in which the spherical barium sulfate-silica composite powder was simply mixed with stearic acid, the stearic acid was present in granular form, resulting in a poor feel when applied with a puff to the skin. Furthermore, in Comparative Example 6, in which the amount of fatty acid was increased, although the penetration load was high, the high amount of fatty acid hindered the good feel of the spherical particles, increasing the stickiness of the powder itself and deteriorating the feel. In Comparative Examples 4-5 and 7, which used resin powder and spherical silica, no molded bodies were obtained.

[0117] [Powder Review]

[0118] Using powders 1-7 obtained in Examples 1-7 and comparative powders 1-7 obtained in Comparative Examples 1-7, the components listed in Table 3 were mixed in a mixer and compacted using a press to produce pressed powders 1-14. The resulting pressed powders 1-14 were evaluated for penetration load and feel using the methods described above, and were subjected to a drop test using the method described below. The results are shown in Table 4.

[0119] <Drop test>

[0120] The cosmetic molded article was dropped from a height of 10 cm, the number of times it broke was counted, and the average values ​​were compared (n=5).

[0121] [Table 3]

[0122]

[0123] (Note 1) HG-LFP (manufactured by Sakai Chemical Industry Co., Ltd.): 98.9 wt% barium sulfate, 1.0 wt% palmitic acid, 0.1 wt% magnesium hydroxide

[0124] (Note 2) FINEX-50S-LP2 (manufactured by Sakai Chemical Industry Co., Ltd.): 96 wt% zinc oxide, 4 wt% hydrogenated polydimethylsiloxane

[0125] (Note 3) MKR-1S (manufactured by Sakai Chemical Industry Co., Ltd.): 98.5 wt% titanium oxide, 1.5 wt% hydrogenated polydimethylsiloxane

[0126] (Note 4) Y-2300X (manufactured by Yamaguchi Mica Co., Ltd.): 98 wt% mica, 2 wt% hydrogenated polydimethylsiloxane

[0127] (Note 5) PDM-5L(S) (manufactured by TOPY INDUSTRIES, LIMITED): 98 wt% phlogopite, 2 wt% hydrogenated polydimethylsiloxane

[0128] (Note 6) SA-TALC JA-46R (manufactured by Miyoshi Chemicals Co., Ltd.): 98 wt% talc, 2 wt% hydrogenated polydimethylsiloxane

[0129] (Note 7) SI-RED R-516PS LHC (manufactured by Miyoshi Chemicals Co., Ltd.): 98 wt% red iron oxide, 2 wt% hydrogenated polydimethylsiloxane

[0130] (Note 8) SI-YELLOW LL-100P LHC (manufactured by Miyoshi Chemicals Co., Ltd.): 98 wt% iron oxide yellow, 2 wt% hydrogenated polydimethylsiloxane

[0131] (Note 9) SI-BLACK BL-100P LHC (manufactured by Miyoshi Chemicals Co., Ltd.): Iron oxide black 98 wt%, hydrogenated polydimethylsiloxane 2 wt%

[0132] [Table 4]

[0133]

[0134] The results in Table 4 show that pressed powders 1-7, blended with the powders of Examples 1-7, all exhibited high penetration loads and strong drop resistance. Pressed powders 1-7 spread well and had a pleasant feel when applied to the skin with an appropriate amount using a puff. In contrast, foundations 8-12 and 14, blended with the powders of Comparative Examples 1-5 and 7, exhibited low penetration loads, resulting in low curing strength in the molded bodies. When applied with a puff, the amount of powder adhered equal to or exceeding the amount suitable for application to the skin, resulting in a poor feel. Foundation 13, blended with the powder of Comparative Example 6, exhibited high penetration loads and drop resistance, but the amount applied with a puff was less than the appropriate amount, resulting in poor spread on the skin. Furthermore, the feel of the spherical powders when applied to the skin was felt to the touch, resulting in a sticky, poor feel.

Claims

1. A spherical particle containing barium sulfate, characterized in that: The barium sulfate-containing spherical particles are surface-treated with 1 to 10% by mass of a fatty acid relative to the barium sulfate-containing spherical particles before the surface treatment. The penetration load of the molded article formed by molding the spherical particles containing barium sulfate is 100 mN or more.

2. The spherical particles containing barium sulfate according to claim 1, characterized in that The spherical particles containing barium sulfate are composite particles of barium sulfate and silicon dioxide.

3. A touch improver, characterized in that: The invention comprises the spherical particles containing barium sulfate according to claim 1 or 2.

4. A cosmetic, characterized in that: It contains the touch improver according to claim 3.

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