Particles coated on the surface.

Abstract

Invention details;

Description

surface coated particles

[0001] The present invention relates to surface-coated particles, surface modifiers, cosmetics, a surface modification method, a method for producing surface-coated particles, and a method for producing feel-enhancing particles.

[0002] Cosmetics, skin care products, toiletries, perfumes, and other cosmetic products may contain synthetic polymer microparticles to improve their feel. However, since synthetic polymer microparticles are difficult to decompose in the natural environment and there are concerns that they may have a negative impact on ecosystems, there is a demand for feel-improving particles that can replace synthetic polymer microparticles. Furthermore, examples of feel-improving particles used in cosmetic products include inorganic particles whose surfaces are coated with a silicone compound. Examples of technologies related to such surface-coated particles include those described in JP-A-9-301826 (Patent Document 1) and WO 2020 / 230650 (Patent Document 2).

[0003] Patent Document 1 describes inorganic particles whose surfaces are coated with poly(N-acylalkyleneimine)-modified silicone. Patent Document 2 describes a composite surface-treated inorganic powder in which a base powder mainly made of an inorganic material is surface-treated with a cationic surfactant and an amino-modified silicone.

[0004] The present invention relates to the following [1] to [6]: [1] Surface-coated particles in which a part or all of the surface of a particle (A) is coated with a surface treatment agent (B), wherein a 5% by mass ethanol dispersion of the surface-coated particles is applied to a polyurethane substrate at a concentration of 2 mg / cm ２and drying for 24 hours at 23°C under atmospheric pressure, the surface-coated particles have a dynamic friction coefficient of 0.50 or less, and a standard deviation of the dynamic friction coefficient of 0.020 or less, as measured under conditions of a load of 3.53 N, a movement speed of 10 mm / sec, a movement distance of 50 mm, 30 reciprocations, and a temperature of 25±2°C. [2] A surface modifier comprising the surface-coated particles described in [1] above. [3] A cosmetic product comprising the surface-coated particles described in [1] above. [4] A surface modification method comprising a step of applying the surface-coated particles described in [1] above, the surface modifier described in [2] above, or the cosmetic product described in [3] above to a target surface. [5] A method for producing the surface-coated particles described in [1] above, comprising a step of mixing the particles (A) with a surface treatment agent solution containing the surface treatment agent (B) and a solvent. [6] A method for producing feel-improving particles, comprising a step of selecting, from surface-coated particles in which part or all of the surface of particle (A) is coated with surface treatment agent (B), particles having a dynamic friction coefficient of 0.50 or less and a standard deviation of the dynamic friction coefficient of 0.020 or less, as feel-improving particles, as measured by the following method.

[0005] There is a need for feel-enhancing particles that provide a good feel and allow for a reduction in the amount of synthetic polymer particles used.

[0006] One embodiment of the present invention relates to providing surface-coated particles, surface modifiers, and cosmetics that have a good feel and allow for a reduced amount of synthetic polymer microparticles to be used, as well as a surface modification method using the surface-coated particles, the surface modifier, or the cosmetics. Another embodiment of the present invention relates to providing a method for producing surface-coated particles that have a good feel and allow for a reduced amount of synthetic polymer microparticles to be used. Another embodiment of the present invention relates to providing a method for producing feel-enhancing particles that have a good feel and allow for a reduced amount of synthetic polymer microparticles to be used.

[0007] According to one embodiment of the present invention, there are provided surface-coated particles, surface modifiers, and cosmetics that have a good feel and can reduce the amount of synthetic polymer microparticles used, as well as a surface modification method using the surface-coated particles, the surface modifier, or the cosmetics. Furthermore, according to one embodiment of the present invention, there is provided a method for producing surface-coated particles that have a good feel and can reduce the amount of synthetic polymer microparticles used. Furthermore, one embodiment of the present invention provides a method for producing feel-enhancing particles that have a good feel and can reduce the amount of synthetic polymer microparticles used.

[0008] [Surface-coated particles] The surface-coated particles according to the present invention are particles (A) whose surfaces are partially or entirely coated with a surface treatment agent (B), and a 5% by mass ethanol dispersion of the surface-coated particles is applied to a polyurethane substrate at a concentration of 2 mg / cm ２ and drying for 24 hours at 23°C under atmospheric pressure, the kinetic friction coefficient of the surface-coated particles is measured under conditions of a load of 3.53 N, a movement speed of 10 mm / sec, a movement distance of 50 mm, 30 reciprocations, and a temperature of 25±2°C, and the kinetic friction coefficient is 0.50 or less, and the standard deviation of the kinetic friction coefficient is 0.020 or less. Here, in measuring the kinetic friction coefficient and kinetic friction coefficient of the surface-coated particles, for example, a measuring jig in which a polyurethane substrate is fixed to an indenter of 3 cm x 3 cm can be used.

[0009] The surface-coated particles according to the present invention have a good feel to the touch. Therefore, when the surface-coated particles according to the present invention are incorporated into or used as a cosmetic product, the feel of the cosmetic product can be improved. Furthermore, when the surface-coated particles according to the present invention are used as a surface modifier, the surface of skin, hair, nails, etc. can be modified to have a good feel to the touch. Furthermore, since the surface-coated particles according to the present invention can use particles that do not fall under the category of synthetic polymer fine particles as core particles, they are environmentally friendly and can reduce the amount of synthetic polymer fine particles used.

[0010] In this specification, "partially or entirely coated on the surface of the particle (A) with the surface treatment agent (B)" means that the surface treatment agent (B) is adsorbed to at least a portion of the surface of the particle (A) via intermolecular forces or ionic bonds. The term "adsorption" as used herein does not include a state in which the particle (A) and the surface treatment agent (B) are covalently bonded. Whether or not the surface treatment agent (B) is adsorbed to at least a portion of the surface of the particle (A) is determined by a known method. For example, when the adsorption amount of the surface treatment agent (B) per 100 parts by mass of the particle (A), calculated by "Measurement of the amount of adsorption of the surface treatment agent on inorganic particles" described in the Examples, is greater than 0 parts by mass, preferably 0.1 parts by mass or more, more preferably 0.5 parts by mass or more, the surface treatment agent (B) is considered to be adsorbed on the surface of the inorganic particle (A). In this specification, "feel" refers to the smoothness and lack of squeaky feeling of the particles when applied to skin, hair, nails, etc. The smoother and less squeaky feeling the better the feel. "Smoothness" refers to a feel that is smooth and not powdery, and "squeaky feeling" refers to a feeling that the particles catch when the fingers are brought into contact with and moved over the skin, hair, nails, etc.

[0011] The dynamic friction coefficient of the surface-coated particles according to the present invention is 0.50 or less, and from the viewpoint of further improving the feel, it is preferably 0.45 or less, more preferably 0.43 or less, even more preferably 0.40 or less, even more preferably 0.35 or less, even more preferably 0.32 or less, even more preferably 0.30 or less, even more preferably 0.29 or less, even more preferably 0.28 or less, and even more preferably 0.26 or less. The lower limit of the dynamic friction coefficient is not particularly limited, but is, for example, 0.10 or more, or may be 0.13 or more, 0.16 or more, or 0.18 or more. The dynamic friction coefficient of the surface-coated particles according to the present invention can be specifically measured by the method described in the examples.

[0012] The standard deviation of the dynamic friction coefficient of the surface-coated particles according to the present invention is 0.020 or less, and from the viewpoint of further improving the feel, it is preferably 0.018 or less, more preferably 0.017 or less, and even more preferably 0.016 or less. The lower limit of the standard deviation of the dynamic friction coefficient is not particularly limited, but may be, for example, 0.001 or more, 0.003 or more, 0.005 or more, or 0.006 or more. The standard deviation of the dynamic friction coefficient of the surface-coated particles according to the present invention can be measured specifically by the method described in the Examples.

[0013] The content of the water-insoluble synthetic polymer that is solid at 25°C in the surface-coated particles of the present invention is preferably less than 1% by mass, more preferably less than 0.5% by mass, even more preferably less than 0.1% by mass, and even more preferably less than 0.01% by mass, from the viewpoint of further improving environmental compatibility. It is preferable that the surface-coated particles of the present invention are substantially free of the synthetic polymer. As used herein, "substantially free of the synthetic polymer" means that the synthetic polymer is not intentionally added, and does not exclude the presence of a small amount of the synthetic polymer as an impurity. As used herein, "water-insoluble synthetic polymer" refers to a synthetic polymer that dissolves 2 g or less when 10 g of the synthetic polymer is mixed in 1000 mL of water at 20°C and pH 7 according to OECD Guideline 120 and stirred for 24 hours. Furthermore, "solid at 25°C" refers to a state in which the synthetic polymer does not have fluidity in bulk at 25°C under 1 atmosphere.

[0014] The volume median particle size (D ５０ From the viewpoint of further improving the feel, the volume median particle diameter (D) is preferably more than 1 μm, more preferably more than 2 μm, and even more preferably more than 3 μm, and is preferably 30 μm or less, more preferably 20 μm or less, even more preferably 15 μm or less, and even more preferably 12 μm or less. ５０ ) is the 50% median diameter measured by a particle size distribution measuring instrument using a laser diffraction / scattering method, and specifically can be measured by the method described in the examples.

[0015] From the viewpoint of further improving the feel of the surface-coated particles according to the present invention, it is preferable that the surface treatment agent (B) is adsorbed to the surface of the particle (A) via an intermolecular force or an ionic bond. In this specification, whether or not the particle (A) and the surface treatment agent (B) are adsorbed via an intermolecular force or an ionic bond can be confirmed by a known method, for example, by the change in the amount of adsorption after washing the surface-coated particles with a solvent in which the surface treatment agent (B) is soluble, and specifically, by the method described in the examples.

[0016] Hereinafter, each component constituting the surface-coated particles according to the present invention and a method for producing the surface-coated particles will be described in order.

[0017] <Particles (A)> From the viewpoint of further improving the feel and environmental compatibility of the surface-coated particles, the particles (A) preferably contain at least one selected from inorganic particles (A1) and polysaccharide particles (A2). Since the inorganic particles (A1) and polysaccharide particles (A2) do not fall under the category of synthetic polymer fine particles, surface-coated particles having at least one selected from inorganic particles (A1) and polysaccharide particles (A2) as core particles have improved environmental compatibility and are more suitable as a substitute for synthetic polymer fine particles. From the viewpoint of further improving the feel and environmental compatibility of the surface-coated particles, the total content of the inorganic particles (A1) and polysaccharide particles (A2) in the particles (A) is preferably 60% by mass or more, more preferably 70% by mass or more, even more preferably 80% by mass or more, even more preferably 90% by mass or more, even more preferably 95% by mass or more, even more preferably 98% by mass or more, and preferably 100% by mass or less. Furthermore, from the viewpoint of further improving the feel and environmental compatibility of the surface-coated particles, the content of synthetic polymer fine particles in particles (A) is preferably 40% by mass or less, more preferably 30% by mass or less, even more preferably 20% by mass or less, even more preferably 10% by mass or less, even more preferably 5% by mass or less, and even more preferably 2% by mass or less, and it is even more preferable that particles (A) are substantially free of synthetic polymer fine particles. Here, "substantially free of synthetic polymer fine particles" means that the particles may contain synthetic polymer fine particles unintentionally present as impurities.

[0018] From the viewpoint of further improving the feel of the surface-coated particles, the inorganic particles (A1) preferably contain silica particles or silicate mineral particles, more preferably contain at least one particle selected from silica particles, talc particles, and mica particles, and even more preferably contain at least one particle selected from silica particles and mica particles. From the viewpoint of further suppressing stickiness at the dry edge, it is more preferable to contain silica particles, and even more preferable to contain porous silica particles. From the viewpoint of further improving the feel of the surface-coated particles, the silicate mineral particles preferably contain at least one selected from talc particles, mica particles, sericite particles, smectite particles, montmorillonite particles, bentonite particles, and kaolin particles, more preferably contain at least one selected from talc particles and mica particles, and even more preferably contain mica particles. The polysaccharide particles (A2) preferably contain cellulose particles.

[0019] When the inorganic particles (A1) contain porous silica particles, the specific surface area of ​​the porous silica particles is preferably 5 m from the viewpoint of suppressing the collapse of the porous silica particles and further improving the feel of the surface-coated particles. ２ / g or more, more preferably 10m ２ / g or more, and preferably 1000m ２ / g or less, more preferably 900m ２ The specific surface area is a BET specific surface area measured in accordance with JIS Z 8830:2013.

[0020] When the inorganic particles (A1) contain porous silica particles, the pore volume of the porous silica particles is preferably 0.1 mL / g or more, more preferably 0.3 mL / g or more, even more preferably 0.5 mL / g or more, from the viewpoint of suppressing the collapse of the porous silica particles and further improving the feel of the surface-coated particles, and is preferably 5 mL / g or less, more preferably 3 mL / g or less, even more preferably 2 mL / g or less. Furthermore, from the viewpoint of the absence of a squeaky feeling, it is preferably 0.3 mL / g or more, more preferably 0.5 mL / g or more, even more preferably 0.8 mL / g or more, even more preferably 0.9 mL / g or more, and is preferably 5 mL / g or less, more preferably 3 mL / g or less, even more preferably 2 mL / g or less. The pore volume can be measured by a gas adsorption method. Examples of the gas adsorption method include JIS Z 8831-2:2010 (Pore size distribution and pore characteristics of powders (solids) - Part 2: Measurement method for mesopores and macropores by gas adsorption) and JIS Z 8831-3:2010 (Pore size distribution and pore characteristics of powders (solids) - Part 3: Measurement method for micropores by gas adsorption).

[0021] The content of at least one particle selected from inorganic particles (A1) and polysaccharide particles (A2) in particles (A) is preferably 50% by mass or more, more preferably 60% by mass or more, even more preferably 70% by mass or more, even more preferably 80% by mass or more, even more preferably 90% by mass or more, even more preferably 95% by mass or more, and preferably 100% by mass or less, from the viewpoint of further improving the feel of the surface-coated particles. The content of at least one particle selected from silica particles and silicate mineral particles in inorganic particles (A1) is preferably 50% by mass or more, more preferably 60% by mass or more, even more preferably 70% by mass or more, even more preferably 80% by mass or more, even more preferably 90% by mass or more, even more preferably 95% by mass or more, and preferably 100% by mass or less, from the viewpoint of further improving the feel of the surface-coated particles. From the viewpoint of further improving the feel of the surface-coated particles, the content of cellulose particles in the polysaccharide particles (A2) is preferably 50% by mass or more, more preferably 60% by mass or more, even more preferably 70% by mass or more, even more preferably 80% by mass or more, even more preferably 90% by mass or more, even more preferably 95% by mass or more, and preferably 100% by mass or less.

[0022] Examples of the shape of the particles (A) include spherical, plate-like, flaky, irregular, etc. Among these, from the viewpoint of further improving the feel of the surface-coated particles, spherical, plate-like, or flaky shapes are preferred, and spherical or flaky shapes are more preferred. More specifically, when the particles (A) are silica particles or polysaccharide particles (A2), spherical shapes are more preferred, and when the particles (A) are silicate mineral particles, flaky shapes are more preferred.

[0023] The volume median particle size (D ５０ ) is preferably 1 μm or more, more preferably 2 μm or more, even more preferably 3 μm or more, and is preferably 30 μm or less, more preferably 20 μm or less, even more preferably 15 μm or less, even more preferably 12 μm or less, from the viewpoint of further improving the feel of the surface-coated particles.

[0024] <Surface Treatment Agent (B)> From the viewpoint of further improving the feel and environmental compatibility of the surface-coated particles, the surface treatment agent (B) preferably contains at least one selected from a modified silicone (b1) (hereinafter also referred to as "modified silicone (b1)") that is liquid at 25°C and a water-soluble cationic polymer (b2). From the viewpoint of further suppressing stickiness at the dry edge, the surface treatment agent (B) more preferably contains a modified silicone (b1) that is liquid at 25°C. In this specification, "liquid at 25°C" refers to a state in which the modified silicone (b1) and the water-soluble cationic polymer (b2) that are liquid at 25°C have fluidity in a bulk state under 1 atmosphere. Since the modified silicone (b1) and the water-soluble cationic polymer (b2) that are liquid at 25°C do not fall under the category of "synthetic polymers that are solid at 25°C and water-insoluble," surface-coated particles that include at least one selected from the modified silicone (b1) and the water-soluble cationic polymer (b2) that are liquid at 25°C as the surface treatment agent (B) have improved environmental compatibility and are more suitable as a substitute for synthetic polymer microparticles.

[0025] From the viewpoint of further improving the feel and environmental compatibility of the surface-coated particles, the surface treatment agent (B) preferably contains at least one selected from the modified silicone (b1) and the water-soluble cationic polymer (b2) in an amount of 50% by mass or more, more preferably 70% by mass or more, even more preferably 80% by mass or more, still more preferably 90% by mass or more, still more preferably 95% by mass or more, and preferably 100% by mass or less.

[0026] From the viewpoint of improving the feel of the surface-coated particles, the modified silicone (b1) that is liquid at 25°C preferably contains at least one selected from polyether-modified silicones, polyglycerin-modified silicones, branched polyglycerol-modified silicones, and alkyl glyceryl ether-modified silicones, and more preferably contains at least one selected from polyether-modified silicones, polyglycerin-modified silicones, and branched polyglycerol-modified silicones.

[0027] From the viewpoint of further improving the feel of the surface-coated particles, the HLB (hydrophilic-lipophilic balance) of the modified silicone (b1) is preferably 1.0 or more, more preferably 2.0 or more, even more preferably 2.5 or more, and is preferably 20.0 or less, more preferably 18.0 or less, even more preferably 16.0 or less, even more preferably 15.5 or less, even more preferably 15.0 or less, even more preferably 10.0 or less, and even more preferably 5.0 or less. Here, the HLB value is a value indicating the affinity of the modified silicone (b1) for water and oil, and can be calculated by the Griffin method using the following formula: HLB = 20 × [(molecular weight of hydrophilic group contained in the modified silicone (b1)) / (molecular weight of the modified silicone (b1))]. Examples of the hydrophilic group include a hydroxy group and an ethyleneoxy group.

[0028] The viscosity of the modified silicone (b1) at 25°C is preferably 50 mPa·s or more, more preferably 100 mPa·s or more, even more preferably 200 mPa·s or more, even more preferably 400 mPa·s or more, and preferably 500,000 mPa·s or less, more preferably 100,000 mPa·s or less, even more preferably 80,000 mPa·s or less. The viscosity can be measured at 25°C using a Brookfield viscometer in accordance with JIS Z8803:2011 "Method for measuring viscosity of liquids."

[0029] Polyether-modified silicones have a structure in which the hydrocarbon groups on the side chains and / or ends of silicone oil are substituted with polyether groups. The polyether groups in polyether-modified silicones are preferably polyethyleneoxy groups, polypropyleneoxy groups, or polyalkyleneoxy groups in which ethyleneoxy groups (EO) and propyleneoxy groups (trimethyleneoxy groups or propane-1,2-diyloxy groups; PO) are added in a block or random manner, with polyethyleneoxy groups being more preferred. Examples of polyether-modified silicones that can be used include compounds in which polyether groups are grafted onto a silicone main chain, and compounds in which silicone and polyether groups are bonded in a block manner.

[0030] From the viewpoint of further improving the feel of the surface-coated particles, the viscosity of the polyether-modified silicone at 25°C is preferably 50 mPa·s or more, more preferably 100 mPa·s or more, even more preferably 200 mPa·s or more, even more preferably 400 mPa·s or more, even more preferably 450 mPa·s or more, and preferably 3000 mPa·s or less, more preferably 2000 mPa·s or less, even more preferably 1000 mPa·s or less, even more preferably 750 mPa·s or less, even more preferably 600 mPa·s or less. The viscosity can be measured at 25°C using a Brookfield viscometer in accordance with JIS Z8803:2011 "Method for measuring viscosity of liquids."

[0031] Specific examples of polyether-modified silicones include PEG-3 dimethicone, PEG-9 dimethicone, PEG-9 methyl ether dimethicone, PEG-10 dimethicone, PEG-11 methyl ether dimethicone, PEG-12 dimethicone, PEG / PPG-20 / 22 butyl ether dimethicone, PEG-32 methyl ether dimethicone, PEG-9 polydimethylsiloxyethyl dimethicone, lauryl PEG-9 polydimethylsiloxyethyl dimethicone, cetyl PEG / PPG-10 / 1 dimethicone, PEG / PPG-30 / 10 dimethicone, and linear polyether-modified silicones in which dimethyl silicone units and polyether units are alternately copolymerized. Commercially available examples of polyether-modified silicones include the KF series (e.g., KF-6004, KF-6011, KF-6012, KF-6013, KF-6015, KF-6016, KF-6017, KF-6028, KF-6038, KF-6043, KF-6048) manufactured by Shin-Etsu Chemical Co., Ltd., and the DOWSIL series (BY25-339, SH3775M, FZ-2203) manufactured by Dow Chemical Japan Ltd.

[0032] Polyglycerin-modified silicone refers to silicone having a monovalent polyglyceryl group in its structure, and examples thereof include polyglyceryl-3 disiloxane dimethicone, polyglyceryl-3 polydimethylsiloxyethyl dimethicone, and lauryl polyglyceryl-3 polydimethylsiloxyethyl dimethicone. In this specification, branched polyglycerol-modified silicones are excluded from polyglycerin-modified silicones. Commercially available polyglycerin-modified silicones include the KF series (e.g., KF-6100, KF-6104, KF-6106, and KF-6105) manufactured by Shin-Etsu Chemical Co., Ltd.

[0033] From the viewpoint of further improving the feel of the surface-coated particles, the viscosity of the polyglycerin-modified silicone at 25°C is preferably 500 mPa·s or more, more preferably 1,000 mPa·s or more, even more preferably 2,000 mPa·s or more, even more preferably 3,000 mPa·s or more, and is preferably 20,000 mPa·s or less, more preferably 10,000 mPa·s or less, even more preferably 5,000 mPa·s or less, even more preferably 4,000 mPa·s or less. The viscosity can be measured at 25°C using a Brookfield viscometer in accordance with JIS Z8803:2011 "Method for measuring viscosity of liquids."

[0034] Examples of branched polyglycerol-modified silicones include compounds represented by the following formula (1), which have a structure in which branched polyglycerol chains are bonded to both ends of dimethylpolysiloxane via linking groups containing oxyphenylene groups.

[0035] (In formula (1), R １２ each independently represents a branched polyglycerol chain, and m represents an integer of 0 or more and 10,000 or less.

[0036] In formula (1), the oxygen atom in the phenylene group portion and the trimethylene group (-C ３ H ６ The bonding mode of R-) is not particularly limited, and may be at the ortho, meta, or para position. m represents an integer of 0 to 10,000, preferably 1 to 300.１２ represents a branched polyglycerol chain, which is composed of glycerol units represented by the following structural formulas (2) to (5), has at least one glycerol unit having a branched structure represented by structural formula (2), and terminates with a glycerol unit represented by structural formula (5). The average total number of bonds of glycerol units in the branched polyglycerol chain is 3 to 200, preferably 3 to 30.

[0037]

[0038] From the viewpoint of further improving the feel of the surface-coated particles, the viscosity of the branched polyglycerol-modified silicone at 25°C is preferably 10,000 mPa·s or more, more preferably 20,000 mPa·s or more, even more preferably 40,000 mPa·s or more, even more preferably 60,000 mPa·s or more, even more preferably 70,000 mPa·s or more, and preferably 500,000 mPa·s or less, more preferably 100,000 mPa·s or less, even more preferably 80,000 mPa·s or less. The viscosity can be measured at 25°C using a Brookfield viscometer in accordance with JIS Z8803:2011 "Method for measuring viscosity of liquids."

[0039] The branched polyglycerol-modified silicone represented by formula (1) can be produced by, for example, the method described in JP 2004-339244 A, in which 2,3-epoxy-1-propanol is added to a modified silicone having phenyl groups substituted with hydroxy groups at both ends, in the presence of an acidic or basic catalyst, and the resulting mixture is subjected to graft polymerization, or by other commonly known methods. Commercially available branched polyglycerol-modified silicones include, for example, SOFCARE GS-G (manufactured by Kao Corporation).

[0040] Examples of alkyl glyceryl ether-modified silicones include those represented by the following formula (6).

[0041] [In formula (6), Q represents a divalent hydrocarbon group having 3 to 20 carbon atoms, and R １ ~R ９may be the same or different and represent a hydrogen atom, a linear or branched hydrocarbon group having 1 to 32 carbon atoms, or a phenyl group; R １０ and R １１ may be the same or different and represent a hydrogen atom or a linear or branched hydrocarbon group having 1 to 32 carbon atoms; １０ and R １１ may be different from each other. p represents a number of 1 or more and 500 or less, and q represents a number of 1 or more and 50 or less. Note that p and q represent the alkyl glyceryl ether group [-Q-OCH ２ -CH(OR １０ )-CH ２ (OR １１ ) is preferably a number such that the content of is 1% by mass or more and 50% by mass or less.

[0042] In formula (6), the divalent hydrocarbon group having 3 to 20 carbon atoms represented by Q is preferably a linear or branched alkylene group having 3 to 20 carbon atoms. More specific examples include linear alkylene groups such as trimethylene, tetramethylene, pentamethylene, hexamethylene, heptamethylene, octamethylene, nonamethylene, decamethylene, undecamethylene, dodecamethylene, tetradecamethylene, hexadecamethylene, and octadecamethylene; and branched alkylene groups such as propylene, 2-methyltrimethylene, 2-methyltetramethylene, 2-methylpentamethylene, and 3-methylpentamethylene.

[0043] Also, R １ ~R １１ In the definition of R, examples of the linear or branched hydrocarbon group having from 1 to 32 carbon atoms include linear alkyl groups such as methyl, ethyl, propyl, butyl, pentyl, hexyl, octyl, decyl, undecyl, dodecyl, tetradecyl, hexadecyl, octadecyl, eicosyl, doeicosyl, tetraeicosyl, hexaeicosyl, octaeicosyl, and triacontyl; and branched alkyl groups such as isopropyl, sec-butyl, tert-butyl, neopentyl, 1-ethylpropyl, and 1-heptyldecyl. １ ~R ９is preferably a linear or branched alkyl group having 1 to 25 carbon atoms (which may contain a hydrogen atom in part), and more preferably a linear or branched alkyl group having 1 to 22 carbon atoms (which may contain a hydrogen atom in part). １０ , R １１ is preferably a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, more preferably a hydrogen atom.

[0044] Furthermore, p and q are each an alkyl glyceryl ether group [-Q-OCH ２ -CH(OR １０ )-CH ２ (OR １１ ) is preferably a number such that the content of 1% by mass or more and 50% by mass or less, more preferably a number such that the content of 5% by mass or more and 40% by mass or less, and even more preferably a number such that the content of 10% by mass or more and 30% by mass or less. Specifically, from the standpoint of ease of availability of the organopolysiloxane used as a raw material and operability during production, p is in the range of 1 to 500, preferably 10 to 30, and q is in the range of 1 to 50, preferably 1 to 30.

[0045] From the viewpoint of further improving the feel of the surface-coated particles, the viscosity of the alkyl glyceryl ether-modified silicone at 25°C is preferably 1,000 mPa·s or more, more preferably 2,000 mPa·s or more, even more preferably 3,000 mPa·s or more, even more preferably 4,000 mPa·s or more, even more preferably 5,000 mPa·s or more, even more preferably 6,000 mPa·s or more, and preferably 20,000 mPa·s or less, more preferably 10,000 mPa·s or less, even more preferably 8,000 mPa·s or less, even more preferably 7,000 mPa·s or less. The viscosity can be measured at 25°C using a Brookfield viscometer in accordance with JIS Z8803:2011 "Method for measuring viscosity of liquids."

[0046] Such alkyl glyceryl ether-modified silicones can be produced by reacting an organohydrogenpolysiloxane having at least one silicon-hydrogen bond with the corresponding alkenyl glyceryl ether according to the methods described in JP-A-4-134013 and JP-A-2005-194523. Commercially available alkyl glyceryl ether-modified silicones include SI-UGE and SOFCARE RS-U (both manufactured by Kao Corporation).

[0047] These modified silicones (b1) may be used alone or in combination of two or more.

[0048] From the viewpoint of further improving the feel and environmental compatibility of the surface-coated particles, the water-soluble cationic polymer (b2) preferably contains at least one selected from a cationic polymer having a cellulose skeleton, a cationic vinyl polymer, chitin / chitosan, and a halogenated hexadimethrine, more preferably at least one selected from a cationic polymer having a cellulose skeleton, a cationic vinyl polymer, chitin / chitosan, hexadimethrine bromide, and hexadimethrine chloride, more preferably at least one selected from a cationic polymer having a cellulose skeleton, a cationic vinyl polymer, and chitin / chitosan, and even more preferably at least one selected from a cationic polymer having a cellulose skeleton and a cationic vinyl polymer. In this specification, the term "water-soluble polymer" refers to a polymer that dissolves more than 2 g when 10 g of the polymer is mixed in 1000 mL of water at 20 ° C. and pH 7 and allowed to stand for 24 hours. The water-soluble cationic polymer (b2) preferably has a basic group such as a primary to tertiary amino group, a quaternary ammonium group, or a hydrazino group, and more preferably has a tertiary amino group or a quaternary ammonium group. The basic group includes those neutralized with acids such as hydrochloric acid, sulfuric acid, nitric acid, acetic acid, formic acid, maleic acid, fumaric acid, citric acid, tartaric acid, adipic acid, and lactic acid. In this specification, the term "water-soluble cationic polymer (b2)" excludes water-soluble cationic silicones such as water-soluble amino-modified silicones.

[0049] The weight average molecular weight Mw of the water-soluble cationic polymer (b2) is preferably 3,000 or more, more preferably 5,000 or more, even more preferably 15,000 or more, even more preferably 50,000 or more, and even more preferably 100,000 or more, from the viewpoint of improving the feel of the surface-coated inorganic particles. It is also preferably 5 million or less, more preferably 3 million or less, and even more preferably 2 million or less. The weight average molecular weight Mw can be measured by gel permeation chromatography (GPC) using polyethylene glycol as a standard substance. For example, the weight average molecular weight Mw of cationized hydroxyethyl cellulose, which is the water-soluble cationic polymer (b2), can be determined by GPC measurement under the following conditions. <GPC Measurement Conditions> Sample concentration: 1 mg / mL Column: TSKgel α-M x 2 (Tosoh Corporation) Eluent: 0.15 mol / L aqueous sodium sulfate solution (containing 1% acetic acid) Flow rate: 1.0 mL / min Column temperature: 40°C Detector: differential refractometer

[0050] As used herein, the term "cationic polymer having a cellulose skeleton" refers to a polymer that has a cationic group and a cellulose skeleton and has an overall cationic charge. The term "cationic group" refers to a cationic group or a group that can be ionized to become a cationic group, such as a primary amino group, a secondary amino group, a tertiary amino group, or a quaternary ammonium group. Examples of cationic polymers having a cellulose skeleton include cationized cellulose and cationized cellulose derivatives, and specific examples include cationized cellulose, cationized hydroxyethyl cellulose, cationized hydroxypropyl cellulose, and cationized carboxymethyl cellulose. As the cationic polymer having a cellulose skeleton, cationized hydroxyethyl cellulose is preferred, and a quaternary ammonium salt polymer (INCI name: Polyquaternium-10) obtained by adding glycidyltrimethylammonium chloride to hydroxyethyl cellulose is more preferred.

[0051] Examples of cationic vinyl polymers include vinylpyrrolidone / dimethylaminoethyl methacrylate copolymer diethyl sulfate, vinylpyrrolidone / dimethylaminopropyl methacrylamide / lauryldimethylaminopropyl methacrylamide copolymer, vinylpyrrolidone / N,N-dimethylaminoethyl methacrylate / alkyl acrylate / tripropylene glycol diacrylate copolymer, polydimethylmethylenepiperidinium chloride, dimethyldiallylammonium chloride / acrylamide copolymer, trimethylammoniopropylacrylamide chloride / dimethylacrylamide copolymer, alkylacrylamide / acrylate / alkylaminoalkylacrylamide copolymer, Examples of suitable copolymers include vinylpyrrolidone / polyethylene glycol methacrylate copolymer, t-butylacrylamide / dimethylacrylamide / dimethylaminopropylacrylamide / methoxypolyethylene glycol methacrylate copolymer, vinylpyrrolidone / N,N-dimethylaminoethyl methacrylic acid copolymer diethyl sulfate, vinylpyrrolidone / dimethylaminoethyl methacrylate copolymer, N,N-dimethylaminoethyl methacrylic acid diethyl sulfate / N,N-dimethylacrylamide / polyethylene glycol dimethacrylate copolymer, ammonium-modified hydroxyethyl cellulose, and acrylamide / DMAPA acrylate / PEG methoxy methacrylate copolymer. Among these, tertiary amino group-containing (meth)acrylic polymers are preferred, and acrylamide / DMAPA acrylate / PEG methoxy methacrylate copolymer is more preferred.

[0052] Examples of chitin / chitosan include chitin / chitosan derivatives such as hydroxypropyl chitosan, carboxymethyl chitin, and carboxymethyl chitosan, as well as chitin and chitosan, with chitosan being preferred.

[0053] These water-soluble cationic polymers (b2) may be used alone or in combination of two or more.

[0054] The surface treatment agent (B) may contain a surface treatment agent other than the modified silicone (b1) and the water-soluble cationic polymer (b2). Examples of the surface treatment agent other than the modified silicone (b1) and the water-soluble cationic polymer (b2) include surface treatment agents used for cosmetic particles.

[0055] The content of at least one selected from the modified silicone (b1) and the water-soluble cationic polymer (b2) that are liquid at 25°C in the surface treatment agent (B) is preferably 50% by mass or more, more preferably 60% by mass or more, even more preferably 70% by mass or more, even more preferably 80% by mass or more, even more preferably 90% by mass or more, even more preferably 95% by mass or more, and preferably 100% by mass or less, from the viewpoint of further improving the feel of the surface-coated particles and further improving environmental compatibility.

[0056] From the viewpoint of further improving environmental compatibility, the content of the synthetic polymer that is solid at 25°C and water-insoluble in the surface treatment agent (B) is preferably less than 10% by mass, more preferably less than 5% by mass, even more preferably less than 1% by mass, even more preferably less than 0.1% by mass, and even more preferably less than 0.01% by mass, and it is preferable that the surface treatment agent (B) is substantially free of such synthetic polymer.

[0057] In the surface-coated particles according to the present invention, the amount of the surface treatment agent (B) adsorbed to the particles (A) is, from the viewpoint of further improving the feel of the particles, preferably 0.1 parts by mass or more, more preferably 0.5 parts by mass or more, even more preferably 0.7 parts by mass or more, even more preferably 0.9 parts by mass or more, even more preferably 1.0 parts by mass or more, even more preferably 1.5 parts by mass or more, even more preferably 2.0 parts by mass or more, even more preferably 2.5 parts by mass or more, even more preferably 3.5 parts by mass or more, even more preferably 4.5 parts by mass or more, even more preferably 5.5 parts by mass or more, and even more preferably 6.5 parts by mass or more, and is preferably 50 parts by mass or less, more preferably 30 parts by mass or less, even more preferably 20 parts by mass or less, even more preferably 15 parts by mass or less, even more preferably 13 parts by mass or less, even more preferably 10 parts by mass or less, even more preferably 8.5 parts by mass or less, and even more preferably 7.5 parts by mass or less, per 100 parts by mass of the particles (A). The amount of the surface treatment agent (B) adsorbed can be measured by the method described in the Examples.

[0058] [Method for Producing Surface-Coated Particles] The surface-coated particles according to the present invention can be obtained by coating particles (A) with a surface treatment agent (B). Specifically, from the viewpoint of coating particles (A) with the surface treatment agent (B), the method for producing surface-coated particles preferably includes, for example, a step of mixing particles (A) with a surface treatment agent solution containing the surface treatment agent (B) and an organic solvent, and more preferably includes a step of mixing a particle dispersion containing particles (A) and solvent A with a surface treatment agent solution containing the surface treatment agent (B) and solvent B. The solvent may be water or an organic solvent. The organic solvent is not particularly limited, but may include, for example, an alcohol such as methanol, ethanol, 1-propanol, or 2-propanol. Among these alcohols, at least one selected from ethanol and 2-propanol is more preferred, and ethanol is even more preferred.

[0059] The solvent A and the solvent B may be the same or different from each other as long as they are compatible. The solvent A used in the particle dispersion is preferably at least one selected from water and ethanol from the viewpoint of dispersibility of the particles (A). When the surface treatment agent (B) contains a modified silicone (b1), the solvent used in the surface treatment agent solution is preferably an organic solvent from the viewpoint of solubility of the modified silicone (b1), and more preferably ethanol from the viewpoint of compatibility with the solvent A. When the surface treatment agent (B) contains a water-soluble cationic polymer (b2), the solvent used in the surface treatment agent solution is preferably at least one selected from water and ethanol, and more preferably water, from the viewpoint of solubility of the water-soluble cationic polymer (b2). Furthermore, an organic acid such as lactic acid may be further added to the surface treatment agent solution from the viewpoint of improving the solubility of the water-soluble cationic polymer (b2).

[0060] When the particle dispersion is used, the concentration of the particles (A) in the particle dispersion is preferably 0.5% by mass or more, more preferably 1.0% by mass or more, from the viewpoint of efficiently adsorbing the surface treatment agent (B) to the surfaces of the particles (A), and is also preferably 40% by mass or less, more preferably 30% by mass or less, even more preferably 20% by mass or less, and even more preferably 10% by mass or less. When the surface treatment agent solution is used, the concentration of the surface treatment agent (B) in the surface treatment agent solution is preferably 0.5% by mass or more, more preferably 1.0% by mass or more, from the viewpoint of efficiently adsorbing the surface treatment agent (B) to the surfaces of the particles (A), and is also preferably 40% by mass or less, more preferably 30% by mass or less, even more preferably 20% by mass or less, and even more preferably 10% by mass or less.

[0061] The temperature when mixing the particles (A) or the particle dispersion with the surface treatment agent solution is preferably 5°C or higher, more preferably 10°C or higher, from the viewpoint of efficiently adsorbing the surface treatment agent (B) onto the surfaces of the particles (A), and is preferably 70°C or lower, more preferably 50°C or lower, from the viewpoint of suppressing evaporation of the solvent. The mixing time of the particles (A) or the particle dispersion with the surface treatment agent solution is preferably 5 minutes or longer, more preferably 10 minutes or longer, from the viewpoint of sufficiently adsorbing the surface treatment agent (B) onto the surfaces of the particles (A), and is preferably 12 hours or shorter, more preferably 6 hours or shorter, from the viewpoint of production efficiency. In the step of mixing the particles (A) or the particle dispersion with the surface treatment agent solution, a known stirring device can be used.

[0062] The mixture obtained by the above step can be separated using a known method such as centrifugation, filtration, decantation, drying, etc., to recover the surface-coated particles. The obtained surface-coated particles may be classified using a sieve or the like to adjust the particle size.

[0063] [Surface Modifier] The surface-coated particles according to the present invention can be used as a surface modifier. That is, the surface modifier according to the present invention includes the surface-coated particles according to the present invention. In this specification, the term "surface modifier" refers to an agent capable of improving the feel of the surface of skin, hair, nails, etc. The content of the surface-coated particles according to the present invention in the surface modifier according to the present invention is not particularly limited and is set appropriately depending on the type of surface modifier, but is, for example, 0.1% by mass or more, preferably 1% by mass or more, and, for example, 50% by mass or less, preferably 30% by mass or less, and more preferably 10% by mass or less.

[0064] The surface modifier of the present invention can contain optional components used depending on the type of surface modifier, as long as the effects of the present invention are not impaired. Examples of optional components other than the surface-coated particles of the present invention include ultraviolet absorbers, oils, surfactants, water-soluble polymers, thickeners, neutralizing agents, propellants, pH adjusters, disinfectants, anti-inflammatory agents, preservatives, colorants, chelating agents, whitening agents, blood circulation promoters, cooling agents, antiperspirants, insect repellents, physiologically active ingredients, salts, moisturizers, antioxidants, fragrances, plant extracts, etc.

[0065] The surface modifier according to the present invention may be in the form of, for example, a liquid, emulsion, cream, paste, gel, wax, solid, or multilayer. The surface modifier according to the present invention can also be used in the form of, for example, a sheet, a spray, or a mousse. The surface modifier according to the present invention can be applied to, for example, skin (including lips), hair, or nails, and is preferably used by application.

[0066] From the viewpoint of further improving environmental compatibility, the content of synthetic polymer fine particles in the surface modifier according to the present invention is preferably less than 0.01% by mass, more preferably less than 0.005% by mass, and even more preferably less than 0.001% by mass. In this specification, synthetic polymer fine particles refer to fine particles containing 1% by mass or more of a synthetic polymer that is solid and water-insoluble at 25° C. and has a volume median particle size (D ５０ ) refers to fine particles having a size of 0.1 μm or more and 5 mm or less.

[0067] The method for producing the surface modifier according to the present invention is not particularly limited, and it can be produced, for example, by stirring and mixing the components in a known device.

[0068] [Cosmetics] The surface-coated particles according to the present invention can be incorporated into or applied to various cosmetics. That is, the cosmetics according to the present invention contain the surface-coated particles according to the present invention. The content of the surface-coated particles according to the present invention in the cosmetics according to the present invention is not particularly limited as it is determined appropriately depending on the type of cosmetics, but is, for example, 0.1% by mass or more, preferably 1% by mass or more, and for example, 50% by mass or less, preferably 30% by mass or less. In this specification, "cosmetics" refers to products that come into direct contact with the human body, such as cosmetics, skin care products, toiletry products, perfumes, etc.

[0069] The cosmetic product according to the present invention may contain optional components used depending on the type of cosmetic product, as long as the effects of the present invention are not impaired. Examples of optional components other than the surface-coated particles according to the present invention include ultraviolet absorbers, oils, surfactants, water-soluble polymers, thickeners, neutralizing agents, propellants, pH adjusters, disinfectants, anti-inflammatory agents, preservatives, colorants, chelating agents, whitening agents, blood circulation promoters, cooling agents, antiperspirants, insect repellents, physiologically active ingredients, salts, moisturizers, antioxidants, fragrances, plant extracts, etc.

[0070] The cosmetic product according to the present invention may be in the form of, for example, a liquid, emulsion, cream, paste, gel, wax, solid, multi-layer, etc. The cosmetic product according to the present invention can also be used in the form of, for example, a sheet, a spray, a mousse, etc. The cosmetic product according to the present invention can be applied to, for example, the skin (including the lips), hair, nails, etc., and is preferably used by application.

[0071] From the viewpoint of further improving environmental compatibility, the content of synthetic polymer microparticles in the cosmetic product according to the present invention is preferably less than 0.01% by mass, more preferably less than 0.005% by mass, and even more preferably less than 0.001% by mass.

[0072] There are no particular limitations on the method for producing the cosmetic product of the present invention, and it can be produced, for example, by stirring and mixing the components in a known device.

[0073] [Surface Modification Method] The surface modification method according to the present invention includes a step of applying the surface-coated particles according to the present invention, the surface modifier according to the present invention, or the cosmetic product according to the present invention to a target surface. Examples of target surfaces include skin, hair, nails, etc., preferably skin. Methods for applying the surface-coated particles, surface modifier, or cosmetic product according to the present invention to a target surface include, for example, coating, spraying, or casting the surface, or immersing the target object in the surface-coated particles, surface modifier, or cosmetic product according to the present invention.

[0074] [Method for producing feel-improving particles] The method for producing feel-improving particles according to the present invention includes a step of selecting, as feel-improving particles, particles having a dynamic friction coefficient of 0.50 or less and a standard deviation of the dynamic friction coefficient of 0.020 or less, as measured by the following method, from surface-coated particles in which part or all of the surface of particles (A) is coated with a surface treatment agent (B). (Method) A 5% by mass ethanol dispersion of the surface-coated particles is applied to a polyurethane substrate at a concentration of 2 mg / cm. ２ After drying for 24 hours at 23°C under atmospheric pressure, the test is carried out under the conditions of a load of 3.53N, a moving speed of 10 mm / sec, a moving distance of 50 mm, 30 reciprocations, and a temperature of 25±2°C.

[0075] The method for producing feel-improving particles according to the present invention makes it possible to stably obtain feel-improving particles with a good feel. Furthermore, the feel-improving particles obtained by the method for producing feel-improving particles according to the present invention have a good feel. Therefore, the feel-improving particles according to the present invention can improve the feel of cosmetics by blending them in or using them in cosmetics. Furthermore, the feel-improving particles according to the present invention can improve the feel of the surfaces of skin, hair, nails, etc. by using them as a surface modifier. Furthermore, since the feel-improving particles according to the present invention can utilize particles that do not fall under the category of synthetic polymer microparticles as core particles, they are environmentally friendly and suitable as an alternative material to synthetic polymer microparticles. The preferred embodiments of the particles (A), surface treatment agent (B), and surface-coated particles in the method for producing feel-improving particles according to the present invention, as well as the preferred ranges of the kinetic friction coefficient and the standard deviation of the kinetic friction coefficient, are the same as those for the surface-coated particles according to the present invention described above.

[0076] The present invention will be described below with reference to examples, but is not limited to the scope of the examples. In these examples and comparative examples, various measurements and evaluations were carried out by the following methods.

[0077] [Measurement and Evaluation Methods] (1) Measurement of the Amount of Surface Treatment Agent Adsorbed to Particles Before Surface Coating The amount of surface treatment agent adsorbed was determined by measuring the sample through thermogravimetry-differential thermal analysis (TG-DTA) using a thermal analyzer (Thermo plus EVO2 TG-DTA8122) manufactured by Rigaku Corporation. The measurement conditions were as follows: Sample preparation: surface-coated particles obtained in Examples and Comparative Examples and particles before surface coating (approximately 30 mg (precise weighing)) Heating rate: 10°C / min Measurement temperature range: 35 to 800°C Measurement atmosphere: Air (180 mL / min) From the obtained TG-DTA curve, the amount of surface treatment agent adsorbed to 100 parts by mass of particles before surface coating was calculated using the following formula. Here, the amount of surface treatment agent adsorbed to the surface-coated particles was defined as x% by mass (the total amount of surface-coated particles was taken as 100% by mass). Amount of surface treatment agent adsorbed (parts by mass) per 100 parts by mass of particles before surface coating = x / (100 - x) x 100 x is calculated from the following formula: A x x / 100 + A x (1 - x / 100) x y = B A: Mass (mg) of a measured sample of surface-coated particles B: Mass (mg) of a surface-coated particle reduced from 100°C to 800°C y: Mass reduction rate of particles before surface coating from 100°C to 800°C (= mass reduction amount of particles before surface coating from 100°C to 800°C / mass of a measured sample of particles before surface coating)

[0078] (2) The volume median particle size (D) of the particles before surface coating and the surface-coated particles ５０ Using a laser diffraction / scattering particle size distribution analyzer LA-960 manufactured by Horiba Ltd., distilled water was added to a measurement cell, and the particle size distributions of the particles before and after surface coating were measured at a concentration such that the absorbance was in the appropriate range. From the particle size distributions obtained, the volume median particle size (D ５０ ) were calculated respectively.

[0079] (3) Measurement of dynamic friction coefficient: Measured by the method standardized in JIS K7125:1999. Dynamic friction coefficient μｋ is expressed by the following formula 1. Here, F is the friction force and N is the normal load. F = μ ｋ N (Formula 1) μ ｋ For the measurement, a surface property tester ("Tribogear TYPE: 14" manufactured by Shinto Scientific Co., Ltd.) was used. The surface-modified substrate was fixed to the test stand of the tester with double-sided tape, and untreated artificial leather (manufactured by Teijin Cordley Co., Ltd., polyurethane substrate, product name: Cordley (registered trademark) ST2923NY, 3 cm x 10 cm) was fixed to the friction element (3 cm x 3 cm indenter, "ASTM flat indenter" attached to the main body of the surface property tester). A weight of 360 g (vertical load 3.53 N) was placed perpendicular to the friction element, and the artificial leather wrapped around the friction element was brought into contact with the surface-modified substrate and reciprocated. A reciprocating test (travel speed 10 mm / sec, travel distance 50 mm, number of reciprocating movements 30 times (5 reciprocating movements count as 1 measurement, a total of 6 measurements were performed), temperature 25 ± 2 ° C.) was performed, and the obtained dynamic friction coefficient of the 30th reciprocating movement was adopted. Here, the artificial leather (polyurethane substrate) of the measurement jig was replaced every time one measurement (five reciprocating cycles) was completed. The artificial leather was wrapped around the friction element, and the remaining part was folded and fixed. The surface-modified substrate was manufactured by the following method. First, 5% by mass of the particles of the Examples and Comparative Examples and 95% by mass of ethanol were added to a 9 mL screw tube, and the tube was treated in an ultrasonic cleaner for 2 minutes to obtain a surface modifier. Next, the obtained surface modifier was applied at 2 mg / cm to artificial leather ("Cordley (registered trademark) ST2923NY" manufactured by Teijin Cordley Ltd.) consisting of 45% by mass of polyurethane and 55% by mass of polyethylene terephthalate. ２ The mixture was then dried at room temperature (23°C) under atmospheric pressure for 24 hours to obtain a surface-modified substrate.

[0080] (4) Measurement of the standard deviation of the dynamic friction coefficient μ ｋ The standard deviation of the coefficient of dynamic friction was measured in the same manner as in the measurement of the coefficient of dynamic friction, and the standard deviation of the coefficient of dynamic friction in the region from 41,000 to 45,000 milliseconds after the start of the test in the sixth measurement (i.e., the 25th to 30th reciprocation) (i.e., the region at the 30th reciprocation in the sixth measurement) was used.

[0081] (5) Sensory Evaluation (5-1) Absence of Squeakiness and Smoothness Under an environment of a temperature of 20-25°C and a humidity of 25-40% RH, 0.2 g of the particles obtained in the Examples and Comparative Examples was evenly applied to the inside of the forearm using a finger, and the applied material was rubbed with the finger to evaluate the absence of squeakiness and smoothness, respectively, and scored according to the following criteria. Three expert panelists evaluated the sensations of "absence of squeakiness" and "smoothness" for each sample shown in the table below using a reference sample (lauryl methacrylate-ethylene glycol dimethacrylate-sodium methacrylate copolymer particles, volume median particle size (D ５０ The evaluation was carried out in comparison with a sample having a particle size of 2 μm (2 μm, produced according to Example 1 of JP 2006-8980 A). Samples that were equivalent to the reference sample and felt to have excellent smoothness and no creak sensation were given a rating of "5." Samples that were slightly inferior to the reference sample but felt to have excellent smoothness and no creak sensation were given a rating of "4." Samples that were inferior to the reference sample but felt to have average smoothness and no creak sensation were given a rating of "3." Samples that were inferior to the reference sample and felt to have poor smoothness and no creak sensation were given a rating of "2." Samples that were significantly inferior to the reference sample and felt to have very poor smoothness and no creak sensation were given a rating of "1." The average of the evaluators' scores was used. Each evaluator assigned a score in increments of 0.5, including the intermediate score. The lauryl methacrylate-ethylene glycol dimethacrylate-sodium methacrylate copolymer particles correspond to polymer particles commonly used as feel-improving particles.

[0082] [Production of Surface-Coated Particles] Example 1 2 g of a surface treatment agent, polyglycerin-modified silicone 1 (polyglyceryl-3 polydimethylsiloxyethyl dimethicone, "KF-6104" manufactured by Shin-Etsu Chemical Co., Ltd., viscosity at 25°C: 3300 mPa·s), and 98 g of ethanol were added to a 500 mL beaker to prepare a polyglycerin-modified silicone solution. In a separate 500 mL beaker, inorganic particles, silica 1 (porous silica particles, "HCS 160M5" manufactured by JGC Catalysts and Chemicals Co., Ltd.), volume median particle size (D ５０2 g of a sieve containing 200 μm (pore size: 5 μm, pore volume: 0.7 mL / g) and 98 g of ethanol were added, and the mixture was treated for 5 minutes at 200 W using an ultrasonic homogenizer (Ultrasonic Homogenizer US-600E, manufactured by Nippon Seiki Seisakusho Co., Ltd.) to obtain a particle dispersion. The polyglycerin-modified silicone solution was added to the obtained particle dispersion, and the mixture was stirred at 600 rpm for 1 hour at room temperature using a magnetic stirrer. The obtained mixture was separated into particles (dispersoid) and a solution (dispersion medium) by treating at 3000 rpm for 30 minutes using a centrifuge (Hitachi, CR21G III). After removing the supernatant, the precipitate was dried overnight at 50°C under reduced pressure to obtain surface-coated particles. The obtained surface-coated particles were evaluated. The results are shown in the table.

[0083] In Examples 2, 5 to 6, and 8 and Comparative Example 1, surface-coated particles were obtained in the same manner as in Example 1, except that the types of inorganic particles and surface treatment agents were changed to those shown in the table. The obtained surface-coated particles were evaluated. The results are shown in the table below.

[0084] Examples 3, 7, and 9 Surface-coated particles were obtained in the same manner as in Example 1, except that the types of inorganic particles and surface treatment agent were changed to those shown in the table below and "98 g of ethanol" was changed to "98 g of water." The obtained surface-coated particles were evaluated. The results are shown in the table below.

[0085] Example 4 Surface-coated particles were obtained in the same manner as in Example 1, except that the types of inorganic particles and surface treatment agent were changed to those shown in the table below, "98 g of ethanol" was changed to "98 g of water," and 40 mg of 90% lactic acid (product name: Musashino Lactic Acid 90, manufactured by Musashino Chemical Laboratory Co., Ltd.) was added to the resulting cationic vinyl polymer 1 solution. The resulting surface-coated particles were evaluated. The results are shown in the table below.

[0086] Comparative Example 2: Instead of “Silica 1”, “Cellulose 1 (cellulose particles, “CELLULOBEADS D-5” manufactured by Daito Kasei Kogyo Co., Ltd., volume median particle size (D ５０Cellulose particles were obtained by treating in the same manner as in Example 1, except that "polyglycerin-modified silicone 1" was replaced with "polyglycerin-modified silicone 2" (5 μm), and ethanol was used instead of "polyglycerin-modified silicone 1." The obtained cellulose particles were subjected to various evaluations. The results are shown in the table below.

[0087]

[0088]

[0089] The ingredients listed in the table are as follows:

[0090] (Particles) Silica 1 (porous silica particles, manufactured by JGC Catalysts and Chemicals Co., Ltd., "HCS 160M5", volume median particle size (D ５０ ): 5 μm, pore volume: 0.7 mL / g, spherical) Mica 1 (mica particles, Yamaguchi Mica Co., Ltd. "Y-1800", volume median particle diameter (D ５０ Talc 1 (talc particles, Asada Flour Milling Co., Ltd. "JA-13R", volume median particle size (D ５０ : 6 μm, flaky) Titanium oxide 1 (titanium oxide particles, "MP-100" manufactured by Teika Corporation, volume median particle size (D ５０ Cellulose 1 (cellulose particles, "CELLULOBEADS D-5" manufactured by Daito Kasei Kogyo Co., Ltd., volume median particle diameter (D ５０ ): 5 μm)

[0091] (Surface treatment agents) Polyglycerin-modified silicone 1 (polyglyceryl-3 polydimethylsiloxyethyl dimethicone, Shin-Etsu Chemical Co., Ltd. "KF-6104", viscosity at 25°C: 3300 mPa·s) Branched polyglycerol-modified silicone 1 (bis(polyglyceryl-3 oxyphenylpropyl) dimethicone, Kao Corporation "SOFCARE GS-G", viscosity at 25°C: 77000 mPa·s) Polyether-modified silicone 1 (PEG-10 dimethicone, Shin-Etsu Chemical Co., Ltd. "KF-6017", HLB: 4.5, viscosity at 25°C: 490 mPa·s) Cationic hydroxyethyl cellulose 1 (polyquaternium-10, Kao Corporation "Poise C-150L") Cationic vinyl polymer 1 (acrylamide / DMAPA acrylate / methoxy PEG methacrylate copolymer, produced according to Production Example 1 below) Hexadimethrine bromide ("HCS160M5" manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., Mw: 5,000 to 10,000)

[0092] Production Example 1 A four-neck flask equipped with a reflux condenser, a liquid delivery device, a thermometer, a nitrogen gas inlet tube, and a stirrer was heated to 50°C in an oil bath. 100 parts by mass of monomers (monomer mass ratio: N-tert-butylacrylamide / N,N-dimethylacrylamide / methoxypolyethylene glycol monomethacrylate / N-(3-dimethylaminopropyl)acrylamide = 55 / 23 / 20 / 2) were dissolved in 75 parts by mass of ethanol to obtain a monomer solution. Furthermore, 0.2 mol% of initiator (V-65B) relative to the monomer was dissolved in ethanol to a concentration of 5% by mass to obtain an initiator solution. The obtained monomer solution and initiator solution were simultaneously added dropwise to the flask under a nitrogen atmosphere over 130 minutes, and then the temperature was maintained at 50°C for 130 minutes, and then 80°C for a further 120 minutes to allow the reaction to proceed. After polymerization, the ethanol solution of the polymer was poured into n-hexane for reprecipitation purification, and then vacuum dried at 80°C to obtain solid cationic vinyl polymer 1. (Reagents used) N-tert-butylacrylamide (Shinryo Corporation) N,N-dimethylacrylamide (KJ Chemicals Co., Ltd.) Methoxypolyethylene glycol monomethacrylate (average number of moles of ethylene oxide added: 9 (NK Ester M-90G, Shin-Nakamura Chemical Co., Ltd.)) N-(3-dimethylaminopropyl)acrylamide (KJ Chemicals Co., Ltd.) V-65B: 2,2'-azobis-(2,4-dimethylvaleronitrile) (Fujifilm Wako Pure Chemical Industries, Ltd.) Ethanol (Fujifilm Wako Pure Chemical Industries, Ltd.) n-Hexane (Fujifilm Wako Pure Chemical Industries, Ltd.)

[0093] From the table, it can be seen that the surface-coated particles of the Examples are excellent in smoothness and absence of squeaky feeling, and have a good feel. Furthermore, the surface-coated particles of the Examples have core particles that do not fall under the category of synthetic polymer microparticles, and the surface treatment agent does not contain any synthetic polymer that is solid at 25°C and is water-insoluble, so it can be seen that they are environmentally friendly and suitable as an alternative material to synthetic polymer microparticles.

[0094] According to one embodiment of the present invention, there are provided surface-coated particles, surface modifiers, and cosmetics that have a good feel and can reduce the amount of synthetic polymer microparticles used, as well as a surface modification method using the surface-coated particles, the surface modifier, or the cosmetics. Furthermore, according to one embodiment of the present invention, there is provided a method for producing surface-coated particles that have a good feel and can reduce the amount of synthetic polymer microparticles used. Furthermore, one embodiment of the present invention provides a method for producing feel-enhancing particles that have a good feel and can reduce the amount of synthetic polymer microparticles used.

Claims

DEPCT671. Surface-coated particles, in which part or all of the particle surface (A) is coated with a surface treatment agent (B), where the dynamic friction coefficient of the surface-coated particles is 0.50 or less, when 5 percent by mass of the ethanol dispersion of the surface-coated particles is applied to a polyurethane substrate in an amount of 2 mg / cm², and dried for 24 hours under atmospheric pressure at 23 °C, followed by measurements under The load weight is 3.53 N, the speed of movement is 10 mm / s, the distance of movement is 50 mm, the back-and-forth movement is 30 times, and the temperature is 25 ± 2 °C, and the standard deviation of the dynamic friction coefficient is 0.020 or less.

2. The particles coated on the surface according to claim 1, herein the particles (A) consist of at least one type selected from a group consisting of inorganic particles (A1) and polysaccharide particles (A2). 3.

1. Particles coated on the surface under Relief Clause 2, in this case, the inorganic particle (A1) consists of silica particles or silicate mineral particles.

4. Particles coated on the surface under Relief Clause 2 or 3, in this case, the polysaccharide particle (A2) consists of cellulose particles.

5. Particles coated on the surface under any one of Relief Clauses 1 through 4, in this case, the surface treatment substance (B) consists of at least one substance selected from a group consisting of a modified silicone liquid (b1) at 25 °C and a water-soluble cationic polymer (b2).

6. Particles coated on the surface under Relief Clause 5, in this case, the surface treatment substance (B) consists of 50 percent by mass or more of at least one substance selected from a group consisting of a modified silicone (b1) and a water-soluble cationic polymer (b2). 7.Particles coated on the substrate under claim 5 or 6, herein the modified silicone (b1) contains at least one of the selected types from a group consisting of polyether-modified silicone, polyglycerin-modified silicone, branched polyglycerol-modified silicone and alkylglyceryl ether-modified silicone.

8. Particles coated on the substrate under any of claims 5 through 7, herein the water-soluble cationic polymer (b2) contains at least one of the selected types. Apart from the group consisting of cationic polymers with a cellulose main chain, cationic vinyl-based polymers, and chitin / chitosan compounds,9. Particles coated on a surface according to any of claims 1 through 8, where the amount of surface treatment substance (B) adsorbed onto particle (A) is 0.1 parts by mass or more and 50 parts by mass or less than the relative estimate relative to 100 parts by mass of particle (A).

10. Surface modifiers, consisting of particles coated on a surface according to any of claims 1 through 9.11.

12. Surface modification method, consisting of the steps of applying the surface-coated particles under any one of the claims 1 through 9, the surface modifier under claim 10, or the cosmetic product under claim 11 to the surface of an object.

13. Surface modification method under claim 12, where the surface of the object is skin.

14. Method for the production of surface-coated particles under any one of the claims 1 through 9, consisting of the steps of mixing the particles (A) with a solution of a surface treatment substance consisting of the surface treatment substance (B) and a solvent.

15. Method for the production of texture-enhancing particles, consisting of the steps of selecting, as texture-enhancing particles, particles with a dynamic friction coefficient of 0.50 or less as measured by the following method and a standard deviation of the dynamic friction coefficient of 0.020 or less, from among the particles coated on the surface in which part or all of the surface of the particles (A) are coated with the surface treatment substance (B), (Method) 5 percent by mass of ethanol dispersion of the particles coated on the surface is applied to the polyurethane substrate in an amount of 2 mg / cm², and dried for 24 hours under atmospheric pressure at 23 °C, followed by measurements under conditions of a load of 3.53 N, a displacement speed of 10 mm / s, a displacement distance of 50 mm, 30 back-and-forth movements, and a temperature of 25 ± 2 °C;.