JP7157554B2 - External composition containing polymer and metal oxide powder - Google Patents

Description

Article 30, Paragraph 2 of the Patent Act applies May 23, 2018 Orbis The Shop Ikebukuro Marui store and other stores nationwide Disclosure

Application of Article 30, Paragraph 2 of the Patent Act May 23, 2018 Disclosure through online sales

Application of Article 30, Paragraph 2 of the Patent Act Published on the Internet on May 23, 2018

Application of Article 30, Paragraph 2 of the Patent Law May 16, 2018 Disclosure by press release on the Internet

The present invention relates to a topical composition comprising a polymer and a metal oxide powder.

Topical compositions containing metal oxide powders are widely known. For example, fine particles of metal oxides such as titanium oxide, zinc oxide, zirconium oxide, and cerium oxide have the function of scattering, absorbing, and reflecting ultraviolet rays. (for example, Patent Document 1).
Further, there is known a Pickering emulsion stabilized by adsorbing a metal oxide such as silica on the emulsion interface (for example, Patent Document 2).

Japanese Patent Application Laid-Open No. 2017-014300 Japanese Patent Publication No. 2017-503643

Thus, metal oxide powders are widely added to compositions for external use. However, if a thickening agent such as carbomer, which thickens due to electrical repulsion, is further added to this, there is a problem that the interaction with the surface of the metal oxide powder destroys the balance of electrical repulsion and the thickening action is not exhibited. .
Moreover, even with a thickener that thickens in the presence of metal oxide powder, there is a problem that agglomerates are generated, and when applied to the skin, wrinkles occur or water separates.

In view of such problems, the problem to be solved by the present invention is to provide a technique for reducing the problem of aggregation and syneresis in an external composition containing metal oxide powder and polymer.

The present invention, which solves the above problems, is an external composition comprising a graft copolymer having a hydrophilic polymerized side chain and/or a salt thereof, metal oxide powder, and a water-soluble polymer.
The composition for external use of the present invention is unlikely to cause problems of aggregation and syneresis.

In a preferred embodiment of the present invention, the graft copolymer having a hydrophilic polymerized side chain and/or its salt is an acrylic acid/starch graft copolymer and/or its salt.
By using the acrylic acid-starch graft copolymer and/or its salt, the problem of aggregation can be reduced more effectively.

A preferred embodiment of the present invention is a Pickering emulsion in which the metal oxide powder is adsorbed on the emulsion interface.

In a preferred embodiment of the invention, said water-soluble polymer is a polysaccharide.
By using a polysaccharide as the water-soluble polymer, problems of aggregation and syneresis can be further reduced.

In a preferred embodiment of the invention said polysaccharide is a branched polysaccharide having a side chain polysaccharide and a main chain polysaccharide.
By using a branched polysaccharide, the problem of syneresis can be further reduced, and an external composition having excellent formulation stability can be provided.

In a preferred embodiment of the invention said branched polysaccharide is xanthan gum.
By using xanthan gum, it is possible to provide a composition for external use that is more excellent in formulation stability.

In a preferred embodiment of the present invention, the content of the graft copolymer having a hydrophilic polymerized side chain and/or its salt is 0.1 to 0.2% by mass.
By setting the content of the graft copolymer having a hydrophilic polymerized side chain and/or the salt thereof within the above range, the problems of aggregation and syneresis can be significantly reduced.

In a preferred embodiment of the present invention, the content of the water-soluble polymer is 0.1-0.2% by mass.
By setting the content of the water-soluble polymer within the above range, problems of aggregation and syneresis can be significantly reduced.

INDUSTRIAL APPLICABILITY According to the present invention, it is possible to provide an external composition containing a metal oxide powder and a polymer with reduced problems of aggregation and syneresis.

The composition for external use of the present invention is characterized by comprising a graft copolymer having a hydrophilic polymerized side chain and/or a salt thereof, a metal oxide powder and a water-soluble polymer. The configuration of the present invention will be described in detail below.

<1> A graft copolymer having a hydrophilic polymerized side chain and/or a salt thereof ) as an essential component.
As the main chain of such a hydrophilic graft copolymer, polyacrylic acid, polyacrylic acid ester, polymethacrylic acid, polymethacrylic acid ester and the like can be preferably exemplified.
Suitable examples of the hydrophilic polymerized side chains of such a hydrophilic graft copolymer include polysaccharides such as starch and peptides such as polylysine.

The hydrophilic graft copolymer is preferably a type of water-swellable microgel that forms a water-swellable microgel in an aqueous phase and thickens due to friction between swollen microgel particles.
The water-swellable microgel is not easily affected by metal oxide powder, and when combined with a water-soluble polymer described later, significantly reduces aggregation and syneresis of the composition for external use.

As the hydrophilic graft copolymer, an acrylic acid/starch graft copolymer and/or a salt thereof can be particularly preferably exemplified.

Salts of the hydrophilic graft copolymer include alkali metal salts such as sodium salts and potassium salts; alkaline earth metal salts such as calcium salts and magnesium salts; ammonium salts; organic amine salts such as triethylamine salts and triethanolamine salts. ; basic amino acid salts such as lysine salts and arginine salts can be preferably exemplified.
Among them, alkali metal salts are preferred, and sodium salts are most preferred.

As the hydrophilic graft copolymer, commercially available products can be used, and preferred examples include sodium acrylate/starch graft copolymer (trade name “Sunfresh-100ST”; manufactured by Sanyo Chemical Industries, Ltd.). can.

<2> Metal oxide powder The composition for external use of the present invention contains metal oxide powder as an essential component. The metal oxides referred to here also include oxides of metalloids such as silicon.
Examples of metal oxide powders include silica, titanium dioxide, zinc oxide, iron oxide, zirconium oxide and cerium oxide.

When silica powder is used as the metal oxide powder, for example, either so-called dry silica powder produced by vapor phase oxidation of a silicon halide or so-called wet silica powder produced from water glass or the like can be used. may be used.
As dry silica powder, for example Aerosil series (Nippon Aerosil Co., Ltd.), CAB-O-SIL series (Cabot Corporation), HDK series (Asahi Kasei Wacker Silicone Co., Ltd.), as wet silica powder, for example Nipsil series (Tosoh Silica Co., Ltd.), HI-SIL series (PPG), and other commercially available products can be used.

As for other metal oxide powders, since there are many commercially available products, the commercially available products can be used as they are. Specific examples of such commercially available products include "MTY-110M3S" (manufactured by Tayca Corporation), "MTY-02" (manufactured by Tayca Corporation), and "MT-100TV" (Tayca Co., Ltd.) as particulate titanium dioxide. company), "MT-500HSA" (manufactured by Tayca Co., Ltd.), "MT-100T" (manufactured by Tayca Co., Ltd.), "MT-01" (manufactured by Tayca Co., Ltd.), "MT-10EX" (manufactured by Tayca Co., Ltd.) ), “MT-05” (manufactured by Tayca Co., Ltd.), “MT-100Z” (manufactured by Tayca Co., Ltd.), “MT-150EX” (manufactured by Tayca Co., Ltd.), “MT-100AQ” (manufactured by Tayca Co., Ltd.), "MT-100WP" (manufactured by Tayca Co., Ltd.), "MT-100SA" (manufactured by Tayca Co., Ltd.), "MT-500B" (manufactured by Tayca Co., Ltd.), "MT-500SA" (manufactured by Tayca Co., Ltd., "MT- 600B" (manufactured by Tayca Co., Ltd.), "MT-500SAS" (manufactured by Tayca Co., Ltd.), ) "Tipaque CR-50" (manufactured by Ishihara Sangyo Co., Ltd.), "Tipaque TTO-M-1" (manufactured by Ishihara Sangyo Co., Ltd. ) “Tipaque TTO-V4” (manufactured by Ishihara Sangyo Co., Ltd.), “ST-455” (manufactured by Titan Kogyo Co., Ltd.), “STT-65C-S” (manufactured by Titan Kogyo Co., Ltd.), “STT-30EHS” (titanium (manufactured by Kogyo Co., Ltd.), "Bayer Titanium R-KB-1" (manufactured by Bayer AG), and the like.

In addition, as microparticle zinc oxide, "MZ-300" (manufactured by Tayka Co., Ltd.), "MZY-303S" (manufactured by Tayca Co., Ltd.), "MZ-306X" (manufactured by Tayca Co., Ltd.), "MZ-500" (manufactured by Tayca Co., Ltd.) Co., Ltd.), “MZY-505S” (Tayca Co., Ltd.), “MZ-506X” (Tayca Co., Ltd.), “MZ-510HPSX” (Tayca Co., Ltd.), “WSX-MZ-700” (Tayca Co., Ltd.) Co., Ltd.), “SANT-UFZO-450” (manufactured by Miyoshi Kasei Co., Ltd.), “SANT-UFZO-500” (manufactured by Miyoshi Kasei Co., Ltd.), “FZO-50” (manufactured by Ishihara Sangyo Co., Ltd.), “Max Light ZS-032" (manufactured by Showa Denko K.K.), and "Maxlight ZS-032D" (manufactured by Showa Denko K.K.).

The surface of the metal oxide powder is preferably hydrophobized. Hydrophobized metal oxide powder can be produced by reacting metal oxide powder with a hydrophobizing agent to add hydrophobic groups to hydroxyl groups present on the surface of the powder through covalent bonding. It can be prepared by coating the surface with a hydrophobizing agent by physically adhering it.

The hydrophobizing treatment includes a method of treating the metal oxide powder with a hydrophobizing agent such as an organosilicon compound, silicone, hydrocarbon oil, fatty acid, fatty acid amide, fatty acid ester, higher alcohol, or polyoxyalkylene compound.
Particularly preferably, the metal oxide powder is treated using an organosilicon compound or silicone as a hydrophobizing agent.

Examples of organosilicon compounds include hexamethyldisilazane, monomethylsilane, dimethylsilane, trimethylsilane, trimethylethoxysilane, isobutyltrimethoxysilane, trimethylchlorosilane, dimethyldichlorosilane, methyltrichlorosilane, dimethylethoxysilane, dimethyldimethoxysilane, diphenyldisilane. Examples include ethoxysilane, hexamethyldisiloxane, palmitylsilane, and the like. These are used singly or as a mixture of two or more.

In a preferred embodiment of the present invention, metal oxide powder is treated with trimethylsilane, and hydrophobized metal oxide powder having a trimethylsilyl group added to the surface is used, and silica powder is particularly preferably treated with trimethylsilane. and partially hydrophobized silica with trimethylsilyl groups attached to the surface is used.

When silicone is used as the hydrophobizing agent, dimethylsilicone, methylphenylsilicone, α-methylstyrene-modified silicone, chlorophenylsilicone, fluorine-modified silicone and the like can be exemplified.

The average primary particle size of the metal oxide powder is not particularly limited. For example, it can be 1 to 1000 nm, preferably 3 to 100 nm, and more preferably 5 to 30 nm.

Also, the average secondary particle size of the metal oxide powder is not particularly limited. It is preferably 1 μm or less, preferably 500 nm or less, more preferably 200 nm or less, still more preferably 50 nm or less.

Here, the average primary particle size and average secondary particle size can be determined by measuring the maximum size of 2500 or more particles on a scanning electron microscope image and calculating the number average.
In addition, the average secondary particle size can be adjusted by the stress applied during the preparation of the composition for external use.

<3> Water-soluble polymer The composition for external use of the present invention contains a water-soluble polymer as an essential component.
The types of water-soluble polymers are not limited, but examples include vinyl polymers, polyoxyethylene polymers, polyoxyethylene polyoxypropylene copolymer polymers, acrylic polymers, polypeptides and polysaccharides. can be done. Polysaccharides are particularly preferably used.

Examples of vinyl polymers include polyvinyl alcohol, polyvinyl methyl ether, polyvinylpyrrolidone, carboxyvinyl polymer (carbomer) and the like.
Examples of polyoxyethylene-based polymers include polyethylene glycol.
Examples of acrylic polymers include sodium polyacrylate, polyethyl acrylate, polyacrylamide compounds, acrylic acid/alkyl methacrylate copolymers, and the like.
A preferred example of the polypeptide is sodium polyglutamate.

Examples of polysaccharides include gum arabic, tragacanth gum, galactan, guar gum, carob gum, karaya gum, carrageenan, pectin, agar, quince seed, algecolloid, starch, plant-based polymers such as glycyrrhizic acid; xanthan gum, dextran, succinoglycan , microbial polymers such as bull run; starch-based polymers such as carboxymethyl starch and methylhydroxypropyl starch; methylcellulose, nitrocellulose, ethylcellulose, methylhydroxypropylcellulose, hydroxyethylcellulose, sodium cellulose sulfate, hydroxypropylcellulose, sodium carboxymethylcellulose (CMC), crystalline cellulose, cellulose, cellulosic polymers such as stearoxyhydroxypropyl methylcellulose; alginic acid polymers such as sodium alginate and propylene glycol alginate; chondroitin sulfate, hyaluronic acid, dermatan sulfate, heparan sulfate, heparin and keratan mucopolysaccharides such as sulfuric acid and salts thereof;
In particular, it is preferable to use natural polysaccharides such as plant-based polymers and microbial-based polymers.

Moreover, among polysaccharides, it is preferable to use a branched polysaccharide having a main chain polysaccharide and a side chain polysaccharide.
Although the degree of polymerization of the side-chain polysaccharide is not particularly limited, it is preferably 2-5, more preferably 2-4, and still more preferably 3.
The degree of polymerization of the main chain polysaccharide contained in one structural unit of the branched polysaccharide is 2-5, more preferably 2-4, still more preferably 2-3, still more preferably 2.
Xanthan gum can be suitably exemplified as such a branched polysaccharide.

Among the water-soluble polymers specifically listed above, it is preferable to use a water-soluble polymer that exhibits a thickening action due to molecular entanglement. By using such a thickening water-soluble polymer in combination with a hydrophilic graft copolymer that is less susceptible to the influence of metal oxide powder, the effect of reducing aggregation and syneresis of the composition for external use is remarkably exhibited. .

A water-swellable microgel-type hydrophilic graft copolymer is preferable because it is particularly resistant to aggregation, but tends to behave as particles in an aqueous phase and tend to precipitate (separate water). However, by combining with a water-soluble polymer that exhibits a thickening action due to the entanglement of molecules as described above, precipitation of the water-swellable microgel can be prevented and the occurrence of syneresis can be prevented.
In other words, the combination of the water-swellable microgel-type hydrophilic graft copolymer and the water-soluble polymer exhibiting a thickening effect due to the entanglement of the molecules can solve the problem of aggregation and syneresis extremely effectively.

<4> Composition for external use The content of the hydrophilic graft copolymer in the composition for external use is preferably 1% by mass or less, more preferably 0.5% by mass or less, and even more preferably 0.5% by mass or less, from the viewpoint of suppressing aggregation. 0.3% by mass or less, more preferably 0.25% by mass or less, more preferably 0.2% by mass or less, even more preferably 0.15% by mass or less, even more preferably 0.13% by mass or less, still more preferably It is 0.12% by mass or less.

In addition, the content of the hydrophilic graft copolymer is 0.001% by mass or more, more preferably 0.01% by mass or more, still more preferably 0.05% by mass or more, from the viewpoint of suppressing the occurrence of syneresis. It is preferably 0.07% by mass or more, more preferably 0.09% by mass or more, and still more preferably 0.1% by mass or more.

In addition, the content of the hydrophilic graft copolymer is preferably less than 0.2% by mass, more preferably 0.15% by mass or less, and still more preferably 0.13% by mass or less, from the viewpoint of uniformity of the formulation. , and more preferably 0.12% by mass or less.

In addition, the content of the hydrophilic graft copolymer is more preferably 0.01 to 0.2% by mass, more preferably 0.01 to 0.2% by mass, from the viewpoint of improving freshness to the touch of the composition for external use. 15% by mass.

The content of the water-soluble polymer is not particularly limited, and is preferably 1% by mass or less, more preferably 0.01 to 0.5% by mass, and still more preferably 0.01 to 0.3% by mass. can.

In addition, from the viewpoint of suppressing the occurrence of aggregation, the content of the water-soluble polymer is preferably less than 0.25% by mass, more preferably 0.23% by mass or less, further preferably 0.22% by mass or less, and further It is preferably 0.2% by mass or less, more preferably less than 0.2% by mass, and still more preferably 0.19% by mass or less.

In addition, from the viewpoint of suppressing syneresis, the content of the water-soluble polymer is preferably more than 0.05% by mass, more preferably 0.08% by mass or more, further preferably 0.1% by mass or more, and further It is preferably 0.13% by mass or more, more preferably 0.15% by mass or more.

In addition, the content of the water-soluble polymer is preferably 0.05 to 0.25% by mass, more preferably 0.1 to 0.2% by mass, from the viewpoint of improving the freshness of the composition for external use. .

The content of the metal oxide powder is not particularly limited, but is preferably 10% by mass or less, more preferably 0.01 to 5% by mass, still more preferably 0.1 to 2% by mass.

When applied to the skin, the external composition of the present invention is less likely to clump and is less likely to come off, so it is useful in the form of a sunscreen cosmetic. In this case, it is preferred that the composition for external use contains an ultraviolet absorber.
As the ultraviolet absorber, any one used in the field of external skin preparations such as cosmetics can be used without particular limitation. para-aminobenzoic acid ethyl ester, N,N-diethoxy para-aminobenzoic acid ethyl ester, N,N-dimethyl para-aminobenzoic acid ethyl ester, N,N-dimethyl para-aminobenzoic acid butyl ester, N,N-dimethyl para-aminobenzoic acid ethyl ester , diethylaminohydroxybenzoyl hexyl benzoate; anthranilic acid derivatives such as homomenthyl-N-acetylanthranilate; salicylic acid and its sodium salts, amyl salicylate, menthyl salicylate, homomenthyl salicylate, octyl salicylate, phenyl salicylate, benzyl Salicylic acid derivatives such as salicylate, p-isopropanol phenyl salicylate; Octyl cinnamate, ethyl-4-isopropyl cinnamate, methyl-2,5-diisopropyl cinnamate, ethyl-2,4-diisopropyl cinnamate, methyl-2,4- Diisopropyl cinnamate, propyl-p-methoxycinnamate, isopropyl-p-methoxycinnamate, isoamyl-p-methoxycinnamate, 2-ethylhexyl p-methoxycinnamate (ethylhexyl methoxycinnamate, octyl para-methoxycinnamate) , 2-ethoxyethyl-p-methoxycinnamate (cinoxate), cyclohexyl-p-methoxycinnamate, ethyl-α-cyano-β-phenylcinnamate, 2-ethylhexyl 2-cyano-3,3-diphenylacrylate ( octocrylene), glyceryl mono-2-ethylhexanoyl-diparamethoxycinnamate, cinnamic acid derivatives such as ferulic acid and its derivatives; 2,4-dihydroxybenzophenone, 2,2′-dihydroxy-4-methoxybenzophenone, 2 ,2'-dihydroxy-4,4'-dimethoxybenzophenone, 2,2',4,4'-tetrahydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone (oxybenzone-3), 2-hydroxy-4-methoxy- 4'-methylbenzophenone, 2-hydroxy-4-methoxybenzophenone-5-sulfonate, 4-phenylbenzophenone, 2-ethylhexyl-4'-phenyl- Benzophenone derivatives such as benzophenone-2-carboxylate, 2-hydroxy-4-n-octoxybenzophenone, 4-hydroxy-3-carboxybenzophenone; 3-(4′-methylbenzylidene)-d,l-camphor, 3- benzylidene-d,l-camphor; 2-phenyl-5-methylbenzoxazole; 2,2′-hydroxy-5-methylphenylbenzotriazole; 2-(2′-hydroxy-5′-t-octylphenyl)benzo Triazole; 2-(2′-hydroxy-5′-methylphenylbenzotriazole; dibenzalazine; dianisoylmethane; 5-(3,3-dimethyl-2-norbornylidene)-3-pentan-2-one; 4-t- dibenzoylmethane derivatives such as butyl methoxydibenzoylmethane; octyl triazone; urocanic acid derivatives such as urocanic acid and ethyl urocanate; 2-(2′-hydroxy-5′-methylphenyl)benzotriazole, 1-(3, 4-dimethoxyphenyl)-4,4-dimethyl-1,3-pentanedione, hydantoin derivatives such as 2-ethylhexyl dimethoxybenzylidene dioxoimidazolidine propionate; , drometrisol trisiloxane, methyl anthranilate, bisethylhexyloxyphenol methoxyphenyltriazine, rutin and its derivatives, oryzanol and its derivatives are preferred.

Although the content of the ultraviolet absorber is not particularly limited, it is preferably 50% by mass or less, more preferably 0.1 to 30% by mass, and still more preferably 1 to 20% by mass.

Although the dosage form of the external composition is not particularly limited, it is preferably in the form of an emulsion. In particular, it is preferable to form a Pickering emulsion in which the metal oxide powder is adsorbed on the emulsion interface.
When forming a Pickering emulsion, the metal oxide powder is preferably hydrophobized.

In the case of an emulsion form, the type of oil contained in the oil phase is not particularly limited, and liquid oils, solid oils, waxes, hydrocarbon oils, higher fatty acids, higher alcohols, ester oils, silicone oils, etc. may be contained. can be done.

Examples of liquid oils include avocado oil, camellia oil, turtle oil, macadamia nut oil, corn oil, mink oil, olive oil, rapeseed oil, egg yolk oil, sesame oil, persic oil, wheat germ oil, sasanqua oil, castor oil, and linseed oil. , safflower oil, cottonseed oil, perilla oil, meadowfoam oil, soybean oil, peanut oil, tea seed oil, kaya oil, rice bran oil, cinnamon oil, Japanese pear oil, jojoba oil, germ oil, triglycerin, glycerin trioctanoate, glyceryl triisopalmitate and the like.

Solid oils and fats include cacao butter, coconut oil, horse fat, hydrogenated coconut oil, palm oil, beef tallow, mutton tallow, hydrogenated beef tallow, palm kernel oil, lard, beef bone fat, Japanese wax kernel oil, hydrogenated oil, beef leg fat. , Japanese wax, hydrogenated castor oil and the like.

Waxes include beeswax, candelilla wax, cotton wax, carnauba wax, bayberry wax, wart wax, whale wax, montan wax, bran wax, lanolin, kapok wax, lanolin acetate, liquid lanolin, sugarcane wax, lanolin fatty acid isopropyl, hexyl laurate, reduced lanolin, jojo Barlow, hard lanolin, shellac wax, POE lanolin alcohol ether, POE lanolin alcohol acetate, POE cholesterol ether, lanolin fatty acid polyethylene glycol, POE hydrogenated lanolin alcohol ether and the like.

Hydrocarbon oils include liquid paraffin, ozokerite, pristane, paraffin, ceresin, squalene, petrolatum, microcrystalline wax and the like.

Higher fatty acids include, for example, lauric acid, myristic acid, palmitic acid, stearic acid, behenic acid, 12-hydroxystearic acid, undecylenic acid, and toric acid.

Examples of higher alcohols include cetyl alcohol, stearyl alcohol, behenyl alcohol, batyl alcohol, myristyl alcohol, and cetostearyl alcohol.

Ester oils include isopropyl myristate, cetyl octanoate, octyldodecyl myristate, isopropyl palmitate, butyl stearate, hexyl laurate, myristyl myristate, decyl oleate, hexyldecyl dimethyloctanoate, cetyl lactate, myristyl lactate, Lanolin acetate, isocetyl stearate, isocetyl isostearate, sucrose stearate, sucrose oleate, cholesteryl 12-hydroxystearate, ethylene glycol di-2-ethylhexate, dipentaerythritol fatty acid ester, N-alkyl glycol monoisostearate, dicaprin Neopentyl glycol acid, diisostearyl malate, glyceryl di-2-heptylundecanoate, trimethylolpropane tri-2-ethylhexylate, trimethylolpropane triisostearate, pentaneerythritol tetra-2-ethylhexylate, tri-2- Glyceryl ethylhexylate, trimethylolpropane triisostearate, cetyl 2-ethylhexanoate, 2-ethylhexyl palmitate, glyceryl trimyristate, tri-2-heptyl undecanoic acid glyceride, castor oil fatty acid methyl ester, oleic oil, ceto Stearyl alcohol, acetoglyceride, 2-heptylundecyl palmitate, cetyl palmitate, diisobutyl adipate, N-lauroyl-L-glutamic acid 2-octyldodecyl ester, di-2-heptylundecyl adipate, ethyl laurate, Di-2-ethylhexyl sebacate, 2-hexyldecyl myristate, 2-hexyldecyl palmitate, 2-hexyldecyl adipate, diisopropyl sebacate, 2-ethylhexyl succinate, ethyl acetate, butyl acetate, amyl acetate, citric acid triethyl and the like.

Examples of silicone oils include linear polysiloxanes such as dimethylpolysiloxane, methylphenylpolysiloxane, methylhydrogenpolysiloxane, diphenylsiloxyphenyltrimethicone, pentasiloxane, decamethylpolysiloxane, dodecamethylpolysiloxane, tetramethyltetrahydro Cyclic polysiloxanes such as Genpolysiloxane and the like are included.

Among them, silicone oils, ester oils, liquid fats, solid fats and waxes are preferably used, and diphenylpolysiloxane, cetyl ethylhexanoate and the like are particularly preferably used. 1 type or 2 types or more can be used for an oil agent.

When the composition for external use is in the form of an emulsion, the water content is not particularly limited, but is preferably 45 to 80% by mass, more preferably 55 to 75% by mass, and particularly preferably 60 to 70% by mass. be.
Also, the content of water is preferably 75 to 95% by mass, more preferably 80 to 95% by mass, still more preferably 85 to 93% by mass, relative to the aqueous phase.

When the composition for external use of the present invention is in the form of an emulsion, it may be a water-in-oil emulsion or an oil-in-water emulsion. It is preferably in the form of an oil-in-water emulsion.

In addition to the above ingredients, the composition for external use of the present invention may contain optional ingredients that are usually used in cosmetics as long as they do not impair the effects of the invention. Such optional components include, for example, fatty acid soaps (sodium laurate, sodium palmitate, etc.), potassium lauryl sulfate, anionic surfactants such as alkyl sulfate triethanolamine ether, stearyltrimethylammonium chloride, benzalkonium chloride, lauryl Cationic surfactants such as amine oxides, imidazoline amphoteric surfactants (2-cocoyl-2-imidazolinium hydroxide-1-carboxyethyloxy disodium salt, etc.), betaine surfactants (alkylbetaine, amide betaine, sulfobetaine, etc.), amphoteric surfactants such as acylmethyl taurine, sorbitan fatty acid esters (sorbitan monostearate, sorbitan sesquioleate, etc.), glycerin fatty acids (glyceryl monostearate, etc.), propylene glycol fatty acid esters (propylene glycol monostearate, etc.), hydrogenated castor oil derivatives, glycerin alkyl ether, POE sorbitan fatty acid esters (POE sorbitan monooleate, polyoxyethylene sorbitan monostearate, etc.), POE sorbit fatty acid esters (POE-sorbit monolaurate, etc.), POE glycerin fatty acid esters (POE-glycerin monoisostearate, etc.), POE fatty acid esters (polyethylene glycol monooleate, POE distearate, etc.), POE alkyl ethers (POE 2-octyldodecyl ether, etc.), POE alkylphenyl ethers (POE nonylphenyl ether, etc.), pluronic types, POE/POP alkyl ethers (POE/POP 2-decyltetradecyl ether, etc.), tetronics, POE castor oil/hydrogenated castor oil derivatives (POE castor oil oil, POE hydrogenated castor oil, etc.), nonionic surfactants such as sucrose fatty acid esters and alkyl glucosides, moisturizing ingredients such as sodium pyrrolidonecarboxylate, lactic acid and sodium lactate, optionally surface-treated mica, Powders such as talc, kaolin, synthetic mica, calcium carbonate, magnesium carbonate, barium sulfate, inorganic pigments that may be surface-treated, titanium mica, fish phosphorus foil, bismuth oxychloride that may be surface-treated Pearl agents such as red No. 202, red No. 228, red No. 226, yellow No. 4, blue No. 404, yellow No. 5, red No. 505, red No. 230, red No. 223, orange Organic pigments such as No. 201, Red No. 213, Yellow No. 204, Yellow No. 203, Blue No. 1, Green No. 201, Purple No. 201, Red No. 204, polyethylene powder, polymethyl methacrylate, nylon powder, organopolysiloxane Organic powders such as elastomers, lower alcohols such as ethanol and isopropanol, vitamin A or its derivatives, vitamin B ₆ hydrochloride, vitamin B ₆ tripalmitate, vitamin B ₆ dioctanoate, vitamin B ₂ or its derivatives, vitamin B ₁₂ , vitamin B such as vitamin B ₁₅ or its derivatives, vitamin E such as α-tocopherol, β-tocopherol, γ-tocopherol, vitamin E acetate, vitamin D, vitamin H, pantothenic acid, pantethine, pyrroloquinoline quinone Vitamins and the like can be preferably exemplified.

When the composition for external use is in the form of a Pickering emulsion, a surfactant may be used, but its content is preferably minimized. The surfactant content is preferably 5% by mass or less, more preferably 1% by mass or less, even more preferably 0.1% by mass or less, and particularly preferably 0% by mass.

When the composition for external use is in the form of a Pickering emulsion, it can be produced by dispersing metal oxide powder in an aqueous phase at room temperature and adding an oil phase thereto for emulsification.

The composition for external use of the present invention is preferably used in cosmetics, preferably as a makeup base, foundation, and the like.

<Test Example 1>
An oil-in-water picker containing (A) a hydrophilic graft copolymer, (B) a water-soluble polymer, and (C) a metal oxide powder with the formulations shown in Tables 1 and 2, which are the essential constituents of the present invention. A topical composition in the form of a ring emulsion was prepared. Specifically, among the components shown in Table 1, the metal oxide powder is dispersed in a mixture of aqueous components, and the oil component is added thereto while stirring to emulsify, thereby obtaining the pickers of Examples and Comparative Examples. A ring emulsion was produced.
The silylated silica used in Test Example 1 was obtained by mixing silica fine particles (manufactured by AEROSIL, average primary particle size 12 nm (measurement method described above)) and mono-, di-, and trimethylsilyl hydrophobizing agents. We used what we got.
As a comparative example, a topical composition containing no (A) hydrophilic graft copolymer or (B) water-soluble polymer was also prepared.

The prepared topical compositions of Examples 1 to 8 and Comparative Examples 1 and 2 were evaluated by the following methods for aggregation generation level, formulation stability, formulation uniformity, and freshness to the touch. Based on these evaluation results, a comprehensive evaluation was made according to the following criteria. Table 1 shows the results.

(aggregate generation level)
A skilled evaluator applied the topical compositions of Examples and Comparative Examples to their own skin, and evaluated the degree of aggregate (twist) generation in three grades according to the following criteria.
○: no aggregates are generated △: a little aggregates are generated ×: a large amount of aggregates are generated

(Formulation stability)
When the compositions for external use of Examples and Comparative Examples were allowed to stand at room temperature for 1 week, the extent to which the polymer precipitated and syneresis occurred was evaluated on a three-grade scale according to the following criteria.
○: No separation of water occurs △: A little separation of water occurs ×: A large amount of separation of water occurs

(Preparation uniformity)
The appearance of the external use compositions of Examples and Comparative Examples immediately after preparation was observed, and the homogeneity of the preparations was evaluated in three grades according to the following criteria from the viewpoint of the presence or absence of lumps, the presence of syneresis, and the like.
○: The appearance of the formulation is extremely uniform △: The appearance of the formulation is almost uniform ×: The formulation is extremely non-uniform

(freshness)
A skilled evaluator applied the topical compositions of Examples and Comparative Examples to the subject's own skin, and evaluated the freshness of the subject's skin according to the following three-grade scale.
○: Very good feeling of freshness when applied to the skin △: Feeling of freshness when applied to the skin ×: No feeling of freshness when applied to the skin

(Comprehensive evaluation)
5: Evaluation results for all 4 items are ○ 4: Aggregate generation level and formulation stability are both ○, but one or both of formulation uniformity and freshness are not ○ 3. ... Either one of the aggregate generation level and formulation stability is ○, and either one is △ 2 ... Aggregate generation level and formulation stability are both △ 1 ... Aggregate Either or both of the occurrence level and formulation stability are ×

As shown in Table 2, the composition for external use of Comparative Example 1, which contained xanthan gum but did not contain the sodium acrylate/starch graft copolymer, generated a large amount of aggregates. It can be said that this is because the charge on the surface of the metal oxide powder (silica silylate) inhibited the thickening action of xanthan gum.

In addition, as shown in Table 2, the composition for external use of Comparative Example 2 containing sodium acrylate/starch graft copolymer but not containing xanthan gum did not cause aggregation, but caused significant syneresis, resulting in poor formulation stability. rice field.
It can be said that this is because the sodium acrylate/starch graft copolymer is less susceptible to the surface charge of the metal oxide powder, but is inferior in the ability to retain water.

On the other hand, as shown in Table 1, the topical composition of Example 1 containing the sodium acrylate/starch graft copolymer and the water-soluble polymer showed less aggregates than the topical compositions of Comparative Examples 1 and 2. And the occurrence of water separation was remarkably suppressed.
This result shows that the addition of the sodium acrylate/starch graft copolymer and the water-soluble polymer can reduce the aggregation caused by the surface charge of the metal oxide powder and also reduce the syneresis. there is

As shown in Table 1, the effect of suppressing aggregation and syneresis was also observed in the topical compositions of Examples 2 and 3 using stearoxyhydropropylmethylcellulose and sodium hyaluronate instead of xanthan gum as water-soluble polymers. was done.
Comparing the results of Example 1 with those of Examples 2 and 3, it can be seen that xanthan gum having a polysaccharide side chain is preferably used as the water-soluble polymer from the viewpoint of the effect of reducing aggregation and syneresis.

In addition, as shown in Table 1, instead of silylated silica, the metal oxide powder containing titanium oxide or iron oxide having a similarly charged surface can also suppress aggregation and syneresis. Effects were observed (Examples 4 and 5).
Comparing the results of Example 1 with those of Examples 4 and 5, it can be seen that it is preferable to use silica as the metal oxide powder from the viewpoint of the uniformity of the formulation and the freshness to the touch.

Further, as shown in Table 2, it was found that aggregation and syneresis can be reduced even when the contents of the sodium acrylate/starch graft copolymer and xanthan gum are varied (Examples 6 to 8).

<Test Example 2>
The contents of sodium acrylate/starch graft copolymer and xanthan gum in the formulation of Example 1 shown in Table 1 were variously changed (the balance was adjusted by the content of water), and the same method as in Test Example 1 was used to prepare an oil-in-water type A topical composition in the form of a Pickering emulsion was prepared.
The prepared topical composition was evaluated for aggregation generation level, formulation stability, formulation uniformity and freshness to the touch in the same manner as in Test Example 1, and a comprehensive evaluation was made based on these evaluation results.
Tables 3 and 4 show the contents of the sodium acrylate/starch graft copolymer and xanthan gum and the evaluation results of the composition for external use.

As shown in Tables 3 and 4, it was confirmed that even if the contents of the sodium acrylate/starch graft copolymer and the xanthan gum were variously changed, an effect of reducing aggregation and syneresis could be obtained.

The present invention can be applied to cosmetics.

Claims (6)

A graft copolymer having a hydrophilic polymerized side chain and/or a salt thereof, a metal oxide powder, and a water-soluble polymer ,
the graft copolymer having a hydrophilic polymerized side chain and/or a salt thereof is a starch acrylate graft copolymer and/or a salt thereof;
the water-soluble polymer is a polysaccharide,
A composition for external use , which is a Pickering emulsion in which the metal oxide powder is adsorbed on an emulsion interface . 2. The composition for external use according to claim 1, which is an oil-in-water Pickering emulsion in which the metal oxide powder is adsorbed on the emulsion interface. 3. The composition for external use according to claim 1 or 2 , wherein the polysaccharide is a branched polysaccharide having a side-chain polysaccharide and a main-chain polysaccharide. 4. The composition for external use according to claim 3 , wherein said branched polysaccharide is xanthan gum. The graft copolymer according to any one of claims 1 to 4 , wherein the content of the graft copolymer having a hydrophilic polymerized side chain and/or a salt thereof is 0.1 to 0.2% by mass. A topical composition as described. The composition for external use according to any one of claims 1 to 5 , wherein the content of the water-soluble polymer is 0.1 to 0.2 mass%.