JP2009114088A - External preparation for skin - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an external preparation for skin preventing the discoloration with time to keep the appearance of the external preparation for skin formulated with a benzotriazole derivative and a metal oxide and preventing the lowering of ultraviolet absorbing effect caused by discoloration to attain high durability of the ultraviolet protection effect. <P>SOLUTION: Disclosed is an external preparation for the skin comprising a benzotriazole derivative represented by general formula (I) and a silica-coated metal oxide (in the formula, R' is a 1-6C linear alkyl group; and R" is a 1-3C linear alkyl group). <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an external preparation for skin containing an ultraviolet absorber. More specifically, by incorporating a benzotriazole derivative having a specific structure and a silica-coated metal oxide into an external preparation for skin, there is little discoloration of the preparation over time, and there is an ultraviolet absorption effect in the UV-A to B region. In addition, the present invention relates to an external preparation for skin having improved durability of UV protection.

  In the external preparation for skin, an ultraviolet absorber is blended in order to increase the stability of the blended component against ultraviolet light or to protect the human skin.

  Various types of UV absorbers to be blended with the external preparation for skin are known. UV absorbers that have been used for external preparations for skin are classified according to their structural aspects: (1) benzoic acid derivatives, (2) methoxycinnamic acid derivatives, (3) benzophenone derivatives, (4) dibenzoylmethane derivatives (5) salicylic acid derivatives and the like. In recent years, in particular, the ultraviolet absorbers (2) and (4) are frequently used.

  On the other hand, for the benzotriazole derivative used in the present invention, Patent Document 1 discloses the use of an ultraviolet absorber as a stabilizer for photographic films, lacquers, paints and the like. Patent Document 2 discloses a skin external preparation containing a benzotriazole derivative and a cinnamic acid derivative as an ultraviolet absorber.

  Further, metal oxides such as titanium oxide and zinc oxide, or metal oxides obtained by hydrophobizing these are important blending raw materials for skin external preparations, and are blended in various skin external preparations. Particularly in sunscreen cosmetics, these metal oxides are used as UV scattering agents and become extremely important ingredients for UV protection.

JP-A-3-223384 JP 2005-206473 A

  The topical skin preparation containing a benzotriazole derivative, when combined with a metal oxide such as titanium oxide or zinc oxide, or a metal oxide obtained by hydrophobizing these, causes the formulation to discolor over time, and in particular, UV There was a problem that a decrease in the ultraviolet absorption effect in the -A region (wavelength 320 to 400 nm) was observed.

  As a result of intensive studies in view of the above problems, the inventors of the present invention have surprisingly found that when a metal oxide is coated with silica in a skin external preparation containing a specific benzotriazole derivative and a metal oxide, In order to complete the present invention, it was found that a skin external preparation excellent in discoloration stability of UV, absorbs ultraviolet rays in the UV-A to B region (wavelength 290 to 400 nm), and was excellent in durability of ultraviolet protective effect. It came.

  An object of the present invention is a skin external preparation containing a specific benzotriazole derivative and a metal oxide, which has little discoloration over time, has an excellent ultraviolet absorption effect, and has a long duration of ultraviolet protection effect. An external preparation can be provided.

（Ｉ）
（式中、Ｒ’＝Ｃ１〜Ｃ６の直鎖のアルキル基、Ｒ”＝Ｃ１〜Ｃ３の直鎖のアルキル基である） That is, this invention provides the skin external preparation characterized by containing the benzotriazole derivative shown by the following general formula (I), and a silica coating metal oxide.

(I)
(In the formula, R ′ = C1-C6 linear alkyl group, R ″ = C1-C3 linear alkyl group)

  In the present invention, the benzotriazole derivative may be 2- [4- (2-ethylhexyloxy) -2-hydroxyphenyl] -2H-benzotriazole, 2- (2-hydroxy-4-isobutoxyphenyl) -2H. -The above-mentioned skin external preparation characterized by being 1 type, or 2 or more types chosen from benzotriazole.

    Furthermore, the present invention is the one or more metal oxides selected from the group consisting of titanium oxide, zinc oxide, cerium oxide and iron oxide, wherein the silica-coated metal oxide has a primary particle size of 0.2 μm or less. The above-mentioned external preparation for skin is characterized in that the surface is coated with silica.

  Moreover, this invention provides said skin external preparation characterized by the silica coating amount of the said silica coating metal oxide being 10-30 mass% with respect to the silica coating metal oxide whole quantity. .

  Furthermore, the present invention provides the above-mentioned external preparation for skin, wherein the silica-coated metal oxide is further hydrophobized.

  Even when the benzotriazole derivative and the metal oxide are blended in the external preparation for skin, discoloration with time is reduced. And the skin external preparation which has the ultraviolet absorption effect of UV-A-B area | region, and improved the durability of the ultraviolet-ray defense effect can be provided.

  Hereinafter, the present invention will be described in detail.

（Ｉ）
（式中、Ｒ’＝Ｃ１〜Ｃ６の直鎖のアルキル基、Ｒ”＝Ｃ１〜Ｃ３の直鎖のアルキル基である） The benzotriazole derivative blended as an ultraviolet absorber in the external preparation for skin of the present invention is a compound of the following general formula (I). The skin external preparation has ultraviolet absorption in the UV-A to B region, and is excellent in compatibility with various oils of the skin external preparation base. In particular, it is remarkably excellent in compatibility and stability with di-2-ethoxyethyl succinate which is important as an oil component.

(I)
(In the formula, R ′ = C1-C6 linear alkyl group, R ″ = C1-C3 linear alkyl group)

  Among the benzotriazole derivatives of the above general formula (I), 2- [4- (2-ethylhexyloxy) -2-hydroxyphenyl] -2H-benzotriazole, 2- (2-hydroxy-4-isobutoxyphenyl) -2H-benzotriazole is most excellent in terms of the excellent absorption effect in the UV-A to B region and the durability of UV protection.

  The benzotriazole derivative represented by the general formula (I) used in the present invention can be produced by the method described in Patent Document 2 (Japanese Patent Laid-Open No. 2005-206473).

  A compounding quantity is 0.01-10 mass% normally with respect to skin external preparation whole quantity, Preferably, it is 0.1-5 mass%.

The silica-coated metal oxide used in the present invention is a powder obtained by coating a metal oxide with silica by a conventional method. For example, a method using a water-soluble silicate (water glass), a method using an alkoxysilane, a method using a combination of a water-soluble silicate and a hydrolyzed oligomer of alkoxysilane, and the like have been proposed (for example, see Japanese Patent Application Laid-Open No. Sho-sho). 59-64519, JP-A-60-226805, Japanese Patent No. 2851885, Japanese Patent No. 3520785, Japanese Patent No. 3570730, etc.).
The coating method is not limited, but a method according to Steps 1 to 7 disclosed in Japanese Patent Application Laid-Open No. 2007-16111 is particularly preferable.

  The metal oxide is preferably titanium oxide, zinc oxide, cerium oxide, or iron oxide powder. Particularly preferred are titanium oxide and zinc oxide. Particulate zinc oxide powder is most preferred. In the present invention, two or more metal oxide powders may be blended.

The silica coating amount is preferably 10 to 30% by mass, more preferably 15 to 25% by mass, based on the total amount of the silica-coated metal oxide. If the silica coating amount is less than 10% by mass, the metal oxide surface may not be sufficiently covered. On the other hand, if the silica coating amount is more than 30% by mass, the content of the metal oxide itself with respect to the blending amount of the silica-coated metal oxide may be lowered, and the UV protection effect may not be sufficiently satisfied.
The silica-coated metal oxide used in the present invention is the entire surface of one or more metal oxides selected from the group consisting of titanium oxide, zinc oxide, cerium oxide, and iron oxide having a primary particle size of 0.2 μm or less. Is preferably covered with silica.

  The compounding quantity of a silica coating metal oxide is 1-30 weight% normally with respect to the skin external preparation whole quantity, Preferably, it is 3-20 mass%.

The silica-coated metal oxide used in the present invention is preferably further hydrophobized. A preferred hydrophobizing treatment is illustrated.
(1) Methyl hydrogen polysiloxane, methyl hydrogen polysiloxane / dimethyl polysiloxane copolymer, dimethyl polysiloxane, branched silicone-based (ethoxy functional) treatment agent described in JP-A No. 2001-72891 (manufactured by Shin-Etsu Chemical Co., Ltd.) KF9908, KF9909), treatment using silicones such as acrylic silicone treating agent (trade name: KP57 manufactured by Shin-Etsu Chemical Co., Ltd.) described in WO2004 / 091563 (2) Octyltriethoxysilane, hexyltrimethoxysilane, octadecyltriethoxysilane (3) Treatment with fatty acids such as palmitic acid and stearic acid (4) Treatment with alkylated saccharides such as dextrin palmitate in which part of the hydroxyl group of dextrin is alkylesterified; Alkali metal salt (5) N-lauroyl-L-lysine, glutamic acid or its alkali salts, amino acid treatments such as acylated amino acids (6) perfluoroalkyl phosphate diethanolamine salt, Fluorine treatment using fluoroalkylphosphoric acid, perfluorohexylethyltriethoxysilane, perfluorooctylethyltriethoxysilane, a copolymer containing a functional group with a perfluoroalkyl chain length of C4 to C6, etc. (7) Distearyldimethylammonium Treatment of quaternary ammonium salts such as chloride

  In addition to the above essential components, the skin external preparation of the present invention is usually used in skin external preparations such as cosmetics and pharmaceuticals, such as whitening agents, moisturizers, antioxidants, oily components, other ultraviolet absorbers, Surfactants, thickeners, alcohols, powder components, colorants, aqueous components, water, various skin nutrients, and the like can be appropriately blended as necessary and can be produced by conventional methods.

  Particularly preferred oily bases for the external preparation for skin of the present invention are oils of liquid paraffin, squalane, cetyl isooctanoate, triglyceride isooctanoate, and di-2-ethylhexyl succinate. Especially this invention is preferably utilized for the skin external preparation which uses the oily base (especially water-in-oil type emulsion composition) which has di 2-ethylhexyl succinate as a main component.

  The external preparation for skin of the present invention may be in any product form such as an ointment, cream, emulsion, lotion, pack or the like. It is particularly suitable as a sunscreen cosmetic. The dosage form is not particularly limited, but a water-in-oil emulsion composition is preferred.

  The present invention will be specifically described below with reference to examples. The present invention is not limited to these examples.

<Discoloration prevention>
The following skin external preparation was evaluated for yellowing suppression effect.
A sunscreen cosmetic of W / O type emulsified preparation containing 10% by mass of the benzotriazole derivative of the general formula (1) and 23% by mass of the evaluated metal oxide powder was prepared. After storing this in a -5 ° C constant temperature bath for 4 weeks, the color tone of its appearance is measured with a non-contact image colorimeter (Controller: ICC2071, Sensor Head: ICH-4560H, manufactured by Asae Design Office) The color difference (ΔE, vs. origin) was determined.
The evaluated metal oxide powders are a silica-coated metal oxide, a hydrophobized silica-coated metal oxide, and a hydrophobized metal oxide that is not subjected to silica coating as a comparison.

＊１：特許文献２（特開２００５−２０６４７３）の合成例１により製造したもの。

* 1: manufactured according to Synthesis Example 1 of Patent Document 2 (Japanese Patent Laid-Open No. 2005-206473).

＊１ 市販品（製品名 FINEX-50W-LPF1、堺化学工業株式会社）
｛一次粒子径20nmの堺化学工業社製の酸化亜鉛（ＦＩＮＥＸ−５０）にシリカを２５質量％被覆して、このシリカ被覆粉末を、信越化学工業社製のシリコーンＫＦ９９０１を５質量％とシリコーンＫＦ９９０９を３質量％とにより疎水化処理した粉末｝

＊２：一次粒子径20〜30nmのテイカ社製の微粒子酸化亜鉛ＭＺ−５００に、シリカを１８．５質量％被覆して、このシリカ被覆粉末を、オクタデシルトリエトキシシラン８質量％にて処理化処理した粉末。
シリカ被覆処理は、特開２００７−１６１１１記載の方法に準じてシリカ被覆粉末を得た。疎水化処理は、特開２００７−１６１１１の実施例１のステップ５終了後のスラリーに、オクタデシルトリエトキシシラン８重量部を加え、横型ビーズミル中で攪拌混合した。その後、スラリーをニーダーに移し、加熱・減圧して水及びＩＰＡを留去し、さらに１２０℃/３ｈ加熱した。得られた粉体をＪＯミル（セイシン企業製）で粉砕して処理化処理粉体を得た。

＊３：藤本化学製の微粒子酸化亜鉛にシリカを２０質量％被覆して、このシリカ被覆粉末を、オクチルシラン６質量％及び塩化ジステアリルジメチルアンモニウム２質量％にて疎水化処理した粉末。
シリカ被覆処理は、特開２００７−１６１１１記載の方法に準じてシリカ被覆を実施した。疎水化処理は、特開２００７−１６１１１の実施例１のステップ５終了後のスラリーに、オクチルトリエトキシシランを６重量部、ジステアリルジメチルアンモニウム２重量部を加え、横型ビーズミル中で攪拌混合した。その後、スラリーをニーダーに移し、加熱・減圧して水及びＩＰＡを留去し、さらに１２０℃/３ｈ加熱した。得られた粉体をＪＯミル（セイシン企業製）で粉砕して処理化処理粉体を得た。

＊４：実施例３の＊３においてシリカ被覆をせずに、オクチルシラン６質量％及び塩化ジステアリルジメチルアンモニウム２質量％にて疎水化処理した粉末。 Table 2 shows the color measurement results. In Comparative Example 1 in which a metal oxide not coated with silica is blended, the color difference is large and unacceptable. In contrast, in Examples 1 to 3, the color difference was suppressed to 20 or less, and an excellent discoloration suppressing effect was exhibited even in the presence of a benzotriazole derivative having a high blending amount (high concentration) of 10% by mass.

* 1 Commercial product (Product name FINEX-50W-LPF1, Sakai Chemical Industry Co., Ltd.)
{Zinc oxide (FINEX-50) manufactured by Sakai Chemical Industry Co., Ltd. with a primary particle size of 20 nm is coated with 25% by mass of silica, and 5% by mass of silicone KF9901 manufactured by Shin-Etsu Chemical Co., Ltd. and silicone KF9909 Is a powder hydrophobized with 3% by mass}

* 2: 18.5% by mass of silica is coated on fine particle zinc oxide MZ-500 manufactured by Teica with a primary particle size of 20 to 30 nm, and this silica-coated powder is treated with 8% by mass of octadecyltriethoxysilane. Treated powder.
In the silica coating treatment, silica-coated powder was obtained according to the method described in JP-A-2007-16111. In the hydrophobization treatment, 8 parts by weight of octadecyltriethoxysilane was added to the slurry after completion of Step 5 in Example 1 of JP2007-16111, and the mixture was stirred and mixed in a horizontal bead mill. Thereafter, the slurry was transferred to a kneader, heated and decompressed to distill off water and IPA, and further heated at 120 ° C./3 h. The obtained powder was pulverized with a JO mill (manufactured by Seishin Enterprise) to obtain a treated powder.

* 3: Powder obtained by coating 20% by mass of silica on fine zinc oxide manufactured by Fujimoto Chemical Co., Ltd., and hydrophobizing this silica-coated powder with 6% by mass of octylsilane and 2% by mass of distearyldimethylammonium chloride.
In the silica coating treatment, silica coating was performed according to the method described in JP-A-2007-16111. In the hydrophobization treatment, 6 parts by weight of octyltriethoxysilane and 2 parts by weight of distearyldimethylammonium were added to the slurry after completion of Step 5 in Example 1 of JP2007-16111, and the mixture was stirred and mixed in a horizontal bead mill. Thereafter, the slurry was transferred to a kneader, heated and decompressed to distill off water and IPA, and further heated at 120 ° C./3 h. The obtained powder was pulverized with a JO mill (manufactured by Seishin Enterprise) to obtain a treated powder.

* 4: Powder obtained by hydrophobizing with 6% by mass of octylsilane and 2% by mass of distearyldimethylammonium chloride without silica coating in * 3 of Example 3.

  The skin external preparation of this invention is shown below.

Example 4 Amount of sunscreen cosmetic (mass%)
(1) Di-2-ethylhexyl succinate 14.0
(2) Isodecyl benzoate 1.0
(3) Dineeopentanoic acid tripropylene glycol 4.5
(4) 2-Ethylhexyl paramethoxycinnamate 7.5
(5) 2- [4- (2-Ethylhexyloxy) -2-hydroxyphenyl] -2H-benzotriazole 1.0
(6) Polyoxyethylene 12-hydroxystearic acid condensate ester
0.5
(7) Polyglycerin 12-hydroxystearic acid condensate ester
1.5
(8) Silica-coated zinc oxide (Maxlite ZS-032 manufactured by Showa Denko KK: Silica coating amount 20% by mass) 5.0
(9) Ion exchange water 51.1
(10) 1,3-butylene glycol 5.0
(11) Ethanol 8.0
(12) Methylparaben 0.1
(13) Sodium glutamate 0.8
(Production method)
A sunscreen cosmetic (sunscreen) is prepared by a conventional method. The sunscreen cosmetics of this formulation are good in discoloration stability over time and feel in use, and the solubility of the UV absorber is also good.

Example 5 Cream content (% by mass)
(1) Decamethylcyclopentasiloxane 20.0
(2) Ethanol 5.0
(3) Isostearyl alcohol 2.0
(4) Dipropylene glycol 3.0
(5) Isostearic acid 2.0
(6) Glyceryl tri-2-ethylhexanoate 5.0
(7) Cetyl 2-ethylhexanoate 2.0
(8) Silicone-treated silica-coated fine particle zinc oxide (zinc oxide of Example 1)
10.0
(9) Sodium chloride 2.0
(10) Trisodium edetate appropriate amount (11) 2- [4- (2-ethylhexyloxy) -2-hydroxyphenyl] -2H-benzotriazole 2.0
(12) 2,4,6-trianilino-p- (carbo-2′-ethylhexyl-1′-oxy) -1,3,5-triazine 0.5
(13) 4-t-butyl-4′-methoxydibenzoylmethane 1.0
(14) 2-Ethylhexyl paramethoxycinnamate 7.5
(15) Carboxymethylcellulose Na 0.5
(16) Ethyl cellulose 1.0
(17) Spherical acrylic resin powder 5.0
(18) Purified water Residue (19) Perfume appropriate amount (production method)
A cream is prepared by a conventional method. The cream of this formulation has good discoloration stability and feel when used, and the solubility of the UV absorber is also good.

Example 6 Cream content (mass%)
(1) Decamethylcyclopentasiloxane 20.0
(2) Trimethylsiloxysilicic acid 1.0
(3) Polyoxyethylene / methylpolysiloxane copolymer 2.0
(4) Dipropylene glycol 4.0
(5) Squalane 5.0
(6) Octylsilane-treated silica-coated fine particle zinc oxide (primary particle diameter 20-30 nm, silica 20% by mass, octyltriethoxysilane 8% by mass hydrophobized) 10.0
(7) Talc (hydrophobized product) 6.0
(8) Paraben appropriate amount (9) Phenoxyethanol appropriate amount (10) Trisodium edetate 0.02
(11) 2- (2-hydroxy-4-isobutoxyphenyl) -2H-benzotriazole
1.0
(12) 2,4,6-trianilino-p- (carbo-2′-ethylhexyl-1′-oxy) -1,3,5-triazine 4.0
(13) 2-Ethylhexyl paramethoxycinnamate 7.0
(14) Diparamethoxycinnamate mono-2-ethylhexanoate glyceryl
0.5
(15) Spherical polyethylene powder 5.0
(16) Dimethyl distearyl ammonium hectorite 1.0
(17) Purified water Residual (18) Perfume appropriate amount (production method)
A cream is prepared by a conventional method. The cream of this formulation has good stability and feel in use, and the solubility of the UV absorber is also good.

Example 7 Cream content (mass%)
(1) Dimethylpolysiloxane 5.0
(2) Decamethylcyclopentasiloxane 20.0
(3) Trimethylsiloxysilicic acid 3.0
(4) Polyoxyethylene / methylpolysiloxane copolymer 3.0
(5) Dipropylene glycol 3.0
(6) Cetyl 2-ethylhexanoate 1.0
(7) Silicone-treated silica-coated fine particle zinc oxide (powder of Example 1)
10.0
(8) Talc 1.0
(9) Silicone-treated silica-coated fine particle titanium oxide (powder coated with 18% by mass of silica on Maxlite F-TS20-D manufactured by Showa Denko KK with a primary particle size of 30 nm and hydrophobized with 7% by mass of dimethylpolysiloxane) 7.0
(10) 2,4-bis-[{4- (2-ethylhexyloxy) -2-hydroxy} -phenyl] -6- (4-methoxyphenyl) -1,3,5-triazine
0.5
(11) 2- [4- (2-Ethylhexyloxy) -2-hydroxyphenyl] -2H-benzotriazole 0.3
(12) 2-Ethylhexyl paramethoxycinnamate 0.4
(13) Appropriate amount of paraben (14) Appropriate amount of phenoxyethanol (15) Trisodium edetate 0.2
(16) Dimethyl distearyl ammonium hectorite 1.0
(17) Polymethylmethacrylic acid copolymer spherical powder 3.0
(18) Purified water Residue (19) Perfume appropriate amount (production method)
A cream is prepared by a conventional method. The cream of this formulation has good stability and feel in use, and the solubility of the UV absorber is also good.

Example 8 Emulsion blending amount (% by mass)
(1) Dimethylpolysiloxane 5.0
(2) Decamethylcyclopentasiloxane 25.0
(3) Trimethylsiloxysilicic acid 5.0
(4) Polyoxyethylene / methylpolysiloxane copolymer 2.0
(5) 2- [4- (2-Ethylhexyloxy) -2-hydroxyphenyl] -2H-benzotriazole 4.0
(6) 2-Ethylhexyl paramethoxycinnamate 7.5
(7) Dipropylene glycol 5.0
(8) Octadecylsilane-treated silica-coated fine particle zinc oxide (fine particle zinc oxide MZ-500 made by Teika having a primary particle size of 20 to 30 nm, coated with 18.5% by weight of silica, octadecyltriethoxysilane by the method described in JP-A-2007-16111 Hydrophobic treatment at 8% by mass)
15.0
(9) Paraben appropriate amount (10) phenoxyethanol appropriate amount (11) edetate trisodium appropriate amount (12) dimethyl distearyl ammonium hectorite 0.5
(13) Spherical polyalkyl acrylate powder 5.0
(14) Purified water residue (15) Perfume appropriate amount (production method)
An emulsion is prepared by a conventional method. The emulsion of this formulation is good in both stability and use feeling, and the solubility of the UV absorber is also good.

Example 9 Emulsion blending amount (% by mass)
(1) Dipropylene glycol 5.0
(2) Stearic acid 1.0
(3) Palmitic acid 1.0
(4) Glyceryl tri-2-ethylhexanoate 3.0
(5) Cetyl 2-ethylhexanoate 2.0
(6) Polyoxyethylene glyceryl isostearate 1.0
(7) Glycerol monostearate 1.0
(8) Polystearic acid polyoxyethylene glycerol 1.0
(9) 2,4-bis-[{4- (2-ethylhexyloxy) -2-hydroxy} -phenyl] -6- (4-methoxyphenyl) -1,3,5-triazine
0.3
(10) 2- [4- (2-Ethylhexyloxy) -2-hydroxyphenyl] -2H-benzotriazole 0.3
(11) Silica-coated fine particle titanium oxide (primary particle diameter 60-100 nm, Eusolex T-AVO manufactured by Merck Co. (silica 13-20 mass% coating) 2.0
(12) Sodium hexametaphosphate 0.1
(13) Phenoxyethanol appropriate amount (14) edetate trisodium appropriate amount (15) 4-t-butyl-4'-methoxydibenzoylmethane 1.0
(16) 2-Ethylhexyl paramethoxycinnamate 7.0
(17) Bentonite 1.0
(18) Eicosene / vinylpyrrolidone copolymer 2.0
(19) Purified water Residue (20) Perfume appropriate amount (production method)
An emulsion is prepared by a conventional method. The emulsion of this formulation has good stability and feel in use, and the solubility of the UV absorber is also good.

Example 10 2 layer type cream blending amount (% by mass)
(1) Dimethylpolysiloxane 5.0
(2) Decamethylcyclopentasiloxane 25.0
(3) Trimethylsiloxysilicic acid 5.0
(4) 2- (2-hydroxy-4-isobutoxyphenyl) -2H-benzotriazole
0.2
(5) 2-Ethylhexyl paramethoxycinnamate 0.1
(6) Polyoxyethylene / methylpolysiloxane copolymer 2.0
(7) Dipropylene glycol 5.0
(8) Silicone-treated silica-coated fine particle zinc oxide (powder of Example 1)
15.0
(9) Dipotassium glycyrrhizinate 0.02
(10) Glutathione 1.0
(11) Thiotaurine 0.05
(12) Clara extract 1.0
(13) Paraben appropriate amount (14) Phenoxyethanol Appropriate amount (15) Trisodium edetate Appropriate amount (16) Dimethyl distearyl ammonium hectorite 0.5
(17) Spherical polyalkyl acrylate powder 5.0
(18) Butylethylpropanediol 0.5
(19) Purified water Residue (20) Perfume appropriate amount (production method)
A two-layer type cream is prepared by a conventional method. The two-layer type cream of this formulation has good stability and feel in use, and the solubility of the UV absorber is also good.

Example 11 Protector blending amount (% by mass)
(1) Dimethylpolysiloxane 3.0
(2) Methylphenylpolysiloxane 2.0
(3) Ethanol 5.0
(4) 2- [4- (2-Ethylhexyloxy) -2-hydroxyphenyl] -2H-benzotriazole 1.0
(5) 2-Ethylhexyl paramethoxycinnamate 1.5
(6) Glycerin 4.0
(7) Dipropylene glycol 5.0
(8) 1,3-butylene glycol 2.0
(9) Di-2-ethylhexyl succinate 3.5
(10) Potassium hydroxide 0.1
(11) Sodium hexametaphosphate 0.1
(12) Thiotaurine 0.1
(13) Trisodium edetate 0.1
(14) 4-t-butyl-4'-methoxydibenzoylmethane 3.0
(15) Silica-coated fine particle titanium oxide (primary particle size 30 nm, Maxlite TS-043, Showa Denko Co., Ltd., silica 10% by mass coating) 1.0
(16) Acrylic acid / alkyl methacrylate copolymer (Pemulene TR-2)
0.1
(17) Carboxyvinyl polymer 0.2
(18) Paraben appropriate amount (19) Purified water Residue (20) Fragrance Appropriate amount (production method)
A protector is prepared by a conventional method. The protector of this formulation has good stability and feel in use, and the solubility of the UV absorber is also good.

  The external preparation for skin of the present invention is a time-lapse that occurs when benzotriazole and metal oxide are used in combination by blending benzotriazole having a specific structure as an ultraviolet absorber and silica-coated metal oxide as an ultraviolet scattering agent. In this invention, the discoloration of the UV-A region and the decrease in the absorption ability of the UV-A region due to the discoloration were solved. Since it has an extremely excellent UV protection effect, it is particularly useful as a sunscreen cosmetic.

Claims (5)

An external preparation for skin, comprising a benzotriazole derivative represented by the following general formula (I) and a silica-coated metal oxide.

(I)
(In the formula, R ′ = C1-C6 linear alkyl group, R ″ = C1-C3 linear alkyl group)   The benzotriazole derivative is selected from 2- [4- (2-ethylhexyloxy) -2-hydroxyphenyl] -2H-benzotriazole and 2- (2-hydroxy-4-isobutoxyphenyl) -2H-benzotriazole. The skin external preparation according to claim 1, wherein the preparation is one or more kinds.   The silica-coated metal oxide has a surface of one or more metal oxides selected from the group consisting of titanium oxide, zinc oxide, cerium oxide, and iron oxide having a primary particle size of 0.2 μm or less with silica. The skin external preparation according to claim 1 or 2, which is coated.   The skin external preparation according to any one of claims 1 to 3, wherein a silica coating amount of the silica-coated metal oxide is 10 to 30% by mass with respect to a total amount of the silica-coated metal oxide.   The skin external preparation according to any one of claims 1 to 4, wherein the silica-coated metal oxide is further hydrophobized.