JPH10265357A - Skin preparation for external use - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a skin preparation for external use excellent in stability, causing no change in color, by using both a dibenzoylmethane-based compound and powder subjected to a specific surface treatment. SOLUTION: This skin preparation for external use comprises a dibenzoylmethane-based compound and powder subjected to a surface treatment with a silicone compound so as to contain >=1.25×10<-3> mol of silicon atom based on 100 m<2> powder surface area. The powder is preferably subjected to surface treatment by bringing the silicone compound in the form of vapor. The dibenzoylmethane-based compound is preferably 4-tert-butyl-4'- methoxydibenzoylmethane. The powder is preferably fine particle titanium dioxide having <=0.2 μm average particle diameter. The addition of the titanium dioxide can provide an anti-suntan cosmetic capable of effectively protecting skin from ultraviolet rays in UV-A and UV-B regions.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an external preparation for skin. More specifically, the present invention relates to a stable external preparation for skin which contains a benzoylmethane compound ultraviolet absorber and powder and does not cause discoloration.

[0002]

2. Description of the Related Art Conventionally, various ultraviolet absorbents and ultraviolet shielding agents have been incorporated into skin external preparations such as sunscreen cosmetics in order to prevent the adverse effects of ultraviolet rays on the human body.

[0003] For example, dibenzoylmethane compounds, benzotriazole compounds, benzophenone compounds, anthranyl compounds and the like are used as UV absorbers in the UV-A region, and para-aminobenzoca is used as UV absorbers in the UV-B region. Acid compounds, dimethylaminobenzoic acid compounds, methoxycinnamic acid compounds, salicylic acid compounds, and urocanic acid compounds are known.

[0004] Further, as an ultraviolet ray blocking agent in the UV-A region, zinc oxide powder, cerium oxide powder and the like are known, and as an ultraviolet ray shielding agent in the UV-B region, titanium dioxide powder and the like are known.

[0005]

Generally, in order to enhance the ultraviolet shielding effect of the external preparation for skin, it is necessary to effectively mix the organic compound-based ultraviolet absorber and the inorganic powder-based ultraviolet shielding agent. When a benzoylmethane compound and an inorganic powder are mixed at the same time, there is a fatal problem that discoloration occurs.

The present inventors have conducted intensive studies in view of the above problems, and as a result, it has been found that when a powder is subjected to a surface treatment with a silicone compound in an amount greater than the amount of hydrophobic treatment conventionally performed, the above problems can be effectively solved. The inventors have found that the present invention can be solved, and have completed the present invention.

An object of the present invention is to provide a skin external preparation which can stably mix a powder such as a dibenzoylmethane-based compound ultraviolet absorber and an inorganic powder-based ultraviolet shield without causing a discoloration problem. It is in.

[0008]

That is, the present invention provides a dibenzoylmethane compound and a surface treatment with a silicone compound so as to contain at least 1.25 × 10 ^-3 mol of silicon atoms per 100 m ^{2 of} powder surface area. And an external preparation for skin characterized by containing a powder having been subjected to the above.

Further, the present invention provides the above external preparation for skin, wherein the powder is a powder which has been subjected to a surface treatment by bringing a silicone compound into contact with the powder in the form of vapor. is there.

Further, the present invention provides the above external preparation for skin, wherein the dibenzoylmethane compound is 4-tert-butyl-4'-methoxydibenzoylmethane.

Further, the present invention provides the above external preparation for skin, wherein the powder is a fine particle titanium dioxide having an average particle diameter of 0.2 μm or less.

Hereinafter, the configuration of the present invention will be described in detail. The dibenzoylmethane-based compound used in the present invention means a compound having a dibenzoylmethane skeleton, and is compounded as an ultraviolet absorber in an external preparation for skin such as cosmetics, and a typical example thereof is 4-tert-butyl. -4'-methoxydibenzoylmethane is disclosed in JP-A-55-66535.
Manufactured by the method disclosed in Japanese Patent Publication No.
9 "is commercially available from Givaudan Corporation.

The powder to be surface-treated with the silicone compound used in the present invention is not particularly limited as long as it can be blended with an external preparation for skin. For example, talc, kaolin, mica, sericite, muscovite, Phlogopite, synthetic mica, mica, biotite, lithia mica, permiculite, magnesium carbonate, calcium carbonate, aluminum silicate, barium silicate, calcium silicate, magnesium silicate,
Strontium silicate, metal tungstate, magnesium, silica, zeolite, barium sulfate, calcined calcium sulfate, calcined gypsum, calcium phosphate, fluoroapatite, hydroxyapatite, ceramic powder, metal soap (zinc myristate, calcium palmitate, stearin) Inorganic powder such as aluminum oxide), boron nitride, etc., polyamide resin powder (nylon powder), polyethylene powder, polymethyl methacrylate powder, polystyrene powder, copolymer resin powder of styrene and acrylic acid, benzoguanamine resin powder, polytetrafluoride Organic powders such as ethylene powder and cellulose powder; inorganic white pigments such as titanium dioxide and zinc oxide; inorganic red pigments such as iron oxide (iron oxide) and iron titanate; inorganic brown pigments such as γ-iron oxide; No iron, loess, etc. Yellow pigment black iron oxide, carbon black, inorganic black pigments such as titanium lower oxide, mango violet, inorganic violet pigments such as cobalt violet,
Inorganic green pigments such as chromium oxide, chromium hydroxide, and cobalt titanate; inorganic blue pigments such as ultramarine blue and navy blue; titanium oxide coated mica; titanium oxide coated bismuth oxychloride; titanium oxide coated talc; colored titanium oxide coated mica; Pearl pigments such as bismuth oxychloride and fish scale foil, metal powder pigments such as aluminum powder and copper powder, Red No. 201, Red No. 202, Red No. 204, Red No. 205, Red No. 220, Red No. 226
No. Red No. 228, Red No. 405, Orange No. 203, Orange No. 204, Yellow No. 205, Yellow No. 401, and Blue No. 40
Organic pigments such as No. 4, Red No. 3, Red No. 104, Red No. 1
No. 06, Red No. 227, Red No. 230, Red No. 401,
Powders of organic pigments such as zirconium, barium or aluminum lake such as red 505, orange 205, yellow 4, yellow 5, yellow 202, yellow 203, green 3 and blue 1, etc. Can be done. In particular, in the case of an external preparation for skin, the degree of yellowing is severe when an inorganic powder is used in combination with a dibenzoylmethane-based compound. Further, in order to obtain a skin external preparation such as a sunscreen cosmetic, it is preferable to use an inorganic powder having an ultraviolet shielding effect such as titanium dioxide, zinc oxide and cerium oxide in combination with a dibenzoylmethane compound, and most preferable. The inorganic powder having an ultraviolet shielding effect is fine particle titanium dioxide having an average particle diameter of 0.2 μm or less.

In the present invention, the term “silicone compound” means an organic silicon compound, and the term “surface treatment” means that a powder surface is treated so as to be coated with the silicone compound. Although the surface treatment of the silicone compound in the powder has been conventionally performed as a hydrophobic treatment, the present invention sets the coating amount of the silicone compound to a specific value which is larger than the coating amount of the conventional general hydrophobic treatment. In that case, it was newly found that the effect of the present invention of preventing discoloration is exhibited,
It is necessary to perform a surface treatment with a silicone compound so as to have 1.25 × 10 ⁻³ mol or more of silicon atoms per 100 m ^{2 of the} powder surface area. Powder surface area 100m ²
When the surface treatment amount is less than 1.25 × 10 ^-3 mol per silicon atom, the problem of discoloration or the like cannot be solved, and 1.25 × 10 ^-3 mol silicon atom per 100 m ^{2 of} powder surface area.
With the above surface treatment, the surface of the powder is hydrophobized, and the problem of discoloration can be effectively prevented when it is mixed with a skin external preparation containing a dibenzoylmethane compound.

The amount of silicon atoms per 100 m ^{2 of} powder surface area can be determined by performing elemental analysis on the powder and quantifying the number of carbon atoms bonded to the silicon atoms.

The method for surface treatment of powder with a silicone compound is such that the silicone compound substantially covers the powder surface,
Powder surface area 100 m ² per silicon atom 1.25 × 1
There is no particular limitation as long as it satisfies the condition of being present in an amount of 0 ^-3 mol or more. Examples include direct coating of silicone compounds, emulsion coating, solvent solution coating, and baking treatment. Can be subjected to coating treatment by dispersing and dispersing them and sufficiently stirring. 1.25 silicon atoms per 100 m ^{2 of} powder surface area
There is no special precautions for the presence of × 10 ⁻³ mol or more, but the charge amount and the treatment time of the powder and the silicone compound may be appropriately adjusted depending on the powder, the silicone compound and the surface treatment method used. Good.

A preferred surface treatment method for the silicone compound in the present invention is a method developed by the present applicant to coat the powder by bringing the vapor of the silicone compound into contact with the surface of the powder. No. 113082. That is, by utilizing the active points of the powder on the surface, the active compound is brought into contact with the silicone compound in the form of vapor, and the silicone compound is polymerized on substantially the entire surface of the powder. It is most preferred in the present invention to use a coated powder.

The silicone compound coated in the form of steam is represented by the general formula (1).

Embedded image (R ¹ HSiO) _a (R ² R ³ SiO) _b (R ⁴ R ⁵
R ⁶ SiO _1/2 ) _c (wherein, R ¹ , R ² and R ³ are each independently a hydrogen atom or a group having 1 to 10 carbon atoms which may be substituted with at least one halogen atom. A hydrocarbon group,
Provided that R ¹ , R ² and R ³ are not hydrogen atoms at the same time, and R ⁴ , R ⁵ and R ⁶ are each independently a hydrogen atom or substituted with at least one halogen atom. A is an integer of 0 or 1 or more, b is an integer of 0 or 1 or more, and c is 0 or 2, provided that , C is 0, the sum of a and b is an integer of 3 or more. )

The silicone compound represented by the general formula (1) is roughly classified into a cyclic silicone compound and a linear silicone compound, and the cyclic silicone compound is represented by the general formula (2). , The general formulas “Chemical Formula 3” and “Chemical Formula 4
It is represented by “Formula 5”.

## STR2 ## (R ¹ HSiO) _a (R ² R ³ SiO) _b (wherein R ¹ , R ² , R ³ , a and b have the same meanings as in the above “Chemical formula 1”. ¹ , R ² and R ³ are each independently a lower alkyl group or an aryl group having 1 to 4 carbon atoms (for example, a phenyl group) which may be substituted with at least one halogen atom; Sum is 3
~ 7. )

[0020]

Embedded image (N = 3-7)

Embedded image (N = 3-7)

Embedded image (A + b = 3-7)

The linear silicone compound is represented by the following formula:
It is represented by

Embedded image (R ¹ HSiO) _a (R ² R ³ SiO) _b (R ⁴ R ⁵
R ⁶ SiO _1/2 ) _c (wherein, R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ , a and b have the same meaning as in the above “Chemical Formula 1”, and c is 2) Is preferably a lower alkyl group or an aryl group having 1 to 4 carbon atoms (for example, a phenyl group) in which R ^{1 to} R ⁴ may be independently substituted with at least one halogen atom, and a and b Is 2 to 5.)

Specific examples of the cyclic silicone compound include, for example, dihydrogenhexamethylcyclotetrasiloxane, trihydrogenpentamethylcyclotetrasiloxane, tetrahydrogentetramethylcyclotetrasiloxane, dihydrogenoctamethylcyclopentasiloxane, Trihydrogen heptamethylcyclopentacycloxane, tetrahydrogenhexamethylcyclopentasiloxane, and pentahydrogenpentamethylcyclopentasiloxane can be used, and specific examples of the linear silicone compound include, for example, 1,1,1,2,3,4,
4,4-octamethyltetrasiloxane, 1,1,1,
2,3,4,5,5,5-nonamethylpentasiloxane, 1,1,1,2,3,4,5,6,6,6-decamethylhexasiloxane can be used.

The silicone compound to be brought into contact with the powder in the form of steam is not limited to a silicone compound having a low boiling point, but may be a compound having a high boiling point which is not gaseous at ordinary temperature and normal pressure, or which becomes gaseous at reduced pressure and high temperature. If it is, it can be used. The method of contact between the silicone compound in the form of vapor and the powder is as follows: put the powder and the silicone compound in separate containers in any closed room, desiccator, thermostat, etc., leave the top of each container open and leave You do n’t need any special equipment,
It is preferable to use a device which can be degassed so that the silicone compound is easily vaporized or degassed after surface treatment to remove unpolymerized silicone compound by degassing. For example, a gas sterilizer can be used. Also, by introducing a vaporized silicone compound through a pipe into a closed room containing only powder, the silicone compound can be brought into contact with the surface in the form of vapor to perform surface treatment. Using a carrier gas such as an inert gas,
Surface treatment can also be performed by contacting the powder in the form of a mixed gas of a silicone compound vapor and a carrier gas.
In any of the surface treatment methods, the treatment time is about 30 minutes to 150 hours.

The external preparation for skin of the present invention includes cosmetics, pharmaceuticals,
As a quasi-drug, etc., refers to those applied to the outer skin, and the dosage form is also aqueous, solubilizing, emulsifying, powder, oil-liquid, dispersion, gel, ointment, water-oil- A wide variety of forms such as a three-layer powder system are possible.

The external preparation for skin of the present invention is preferably used as a sunscreen cosmetic containing a dibenzoylmethane ultraviolet absorber. In particular, the present invention has great utility in a sunscreen cosmetic containing titanium dioxide as a dibenzoylmethane-based ultraviolet absorber and an ultraviolet ray blocking agent, and a sunscreen cosmetic that prevents ultraviolet rays in the UV-A and UV-B regions. Charge can be provided. In this case, it is preferable to use titanium dioxide which has been subjected to surface treatment with fine particle titanium dioxide having an average particle size of 0.2 μm or less.

In the external preparation for skin of the present invention, the amount of the powder surface-treated with the dibenzoylmethane compound and the silicone compound is not limited, and is appropriately determined according to the intended product. The external preparation for skin of the present invention, in addition to the above essential constituents, is usually a component that is blended in the external preparation for skin, for example,
Squalane, liquid paraffin, light liquid isoparaffin, petrolatum, microcrystalline wax, ozokerite, ceresin, myristic acid, palmitic acid, stearic acid, oleic acid, isostearic acid, behenic acid,
Cetyl alcohol, stearyl alcohol, oleyl alcohol, batyl alcohol, cetyl-2-ethylhexanoate, 2-ethylhexyl palmitate, 2-octyldodecyl myristate, neopentylglycol-2-ethylhexanoate, glyceride trioctanoate, 2 -Octyldodecyl oleate, isopropyl myristate, myristyl myristate, triisostearate glyceride, trioleic acid glyceride, tricoconut oil fatty acid glyceride, olive oil, avocado oil, jojoba oil, sunflower oil, safflower oil, camellia oil, shea butter, macadamia nut oil , Mink oil, lanolin, castor oil, mokuro, dimethylpolysiloxane, cyclic dimethylpolysiloxane, methylphenylpolysiloxane, polyether-modified silicone, Oils such as various hydrocarbon oils such as unmodified silicone, alkyl-modified silicone, perfluoropolyether and perfluorocarbon, higher fatty acids, higher alcohols, esters, oils and fats, waxes, silicones, fluorine oils, etc .; ethylene glycol, diethylene glycol, , 3-butylene glycol, glycerin, hexamethylene glycol, 1,2-pentanediol, isoprene glycol, polyethylene glycol, propylene glycol, dipropylene glycol, diglycerin, polyglycerin, hyaluronic acid, chondroitin sulfate, chitin, chitosan, etc. Manufacture the desired product by the usual method by appropriately mixing agents, surfactants, ultraviolet absorbers, antioxidants, antiseptics, thickeners, anti-inflammatory agents, vitamins, hormones, whitening agents and other agents, fragrances, etc. You It is possible.

[0027]

Next, the present invention will be described in more detail with reference to Examples and Comparative Examples. The present invention is not limited by this. The compounding amount is% by weight.

"Production Example 1: Surface treatment of silicone compound 2"
Titanium oxide ”titanium dioxide (specific surface area: 50 m^Two/ G,
(Average particle diameter: 25 nm) 200 g, 1, 3, 5, 7-
Directly contact 10 g of tetramethylcyclotetrasiloxane
Put in a separate petri dish so that it does not touch
Then, the pressure was reduced by suction. Then, the desiccator is set to 80 ° C.
Silicone surface in gas phase after leaving in high temperature layer for 16 hours
Processing was performed. After that, titanium dioxide was added at 120 ° C for 2 hours.
Heated for 1 hour, the unpolymerized 1,2
Excluding 3,5,7-tetramethylcyclotetrasiloxane
And the surface is coated with a silicone compound.
I got Tan. Powder surface area 100m Silicon atoms per 2
Is determined by elemental analysis of carbon atoms contained in the powder.
1.25 × 10^-3mol
Was.

"Production Example 2: Silicone compound surface-treated titanium dioxide" titanium dioxide (specific surface area: 50 m ² / g;
(Average particle diameter: 25 nm) 200 g, 1, 3, 5, 7-
Using 12 g of tetramethylcyclotetrasiloxane,
Surface treatment was performed in the same manner as in Production Example 1. Powder surface area 1
The amount of silicon atoms per 00 m ² was calculated from the results of elemental analysis of carbon atoms contained in the powder,
It was 1.43 × 10 ⁻³ mol.

"Production Example 3: Silicone compound surface-treated titanium dioxide" Titanium dioxide (specific surface area: 50 m ² / g,
(Average particle diameter: 25 nm) 200 g, 1, 3, 5, 7-
Surface treatment was carried out in the same manner as in Production Example 1 using 9.5 g of tetramethylcyclotetrasiloxane. The amount of silicon atoms per 100 m ^{2 of} powder surface area was 1.20 × 10 ⁻³ mol as a result of calculation from the results of elemental analysis of carbon atoms contained in the powder.

"Production Example 4: Silicone compound surface-treated titanium dioxide" Titanium dioxide (specific surface area: 50 m ² / g,
(Average particle diameter: 25 nm) 200 g, 1, 3, 5, 7-
Surface treatment was performed in the same manner as in Production Example 1 using 8 g of tetramethylcyclotetrasiloxane. Powder surface area 10
The amount of silicon atoms per 0 m ² was calculated from the results of elemental analysis of carbon atoms contained in the powder,
It was 1.00 × 10 ⁻³ mol.

"Production Example 5: Titanium dioxide treated with stearic acid" 200 g of titanium dioxide (specific surface area: 50 m ² / g, average particle diameter: 25 nm) was added to 2 liters of water, stirred and dispersed, and dispersed therein. 6.0 g of sodium stearate was dissolved, heated to 80 ° C., and stirred for 3 hours.
After that, filtration and washing with water were repeated three times to remove soluble salts from the powder, then dispersed by stirring in 1 liter of acetone, filtered, dried at 60 ° C. for 12 hours, and stearic acid was added to the surface. To obtain titanium dioxide coated.

“Example 1: W / O emulsified sunscreen cream” (% by weight) (1) ethyl cellulose 0.5 (2) ethyl alcohol 4.0 (3) octyl paramethoxycinnamate 5.0 (4) ) 2-Ethylhexyl alcohol succinate 22.0 (5) 4-tertbutyl-4'methoxydibenzoylmethane 2.0 (6) Titanium dioxide of production example 1 6.0 (7) Carboxymethylcellulose 1.0 (8) Purified water 59.0 (9) Preservative appropriate amount (10) Flavor appropriate amount (Production method) After (2) is added to (1) and sufficiently swelled,
(3) to (6) were added and mixed by heating to sufficiently disperse and dissolve. The dispersion was kept at 70 ° C., and emulsified with a homomixer while gradually adding a solution obtained by mixing (8) to (10).
A highly water-resistant W / O emulsified sunscreen cream of the present invention was produced.

"Example 2"
A highly water-resistant W / O emulsified sunscreen cream was produced using the titanium dioxide of Production Example 2 in place of the titanium dioxide of Example 1.

"Comparative Example 1"
A highly water-resistant W / O emulsified sunscreen cream was produced using the titanium dioxide of Production Example 3 in place of the titanium dioxide of Example 1.

"Comparative Example 2"
A highly water-resistant W / O emulsified sunscreen cream was produced using the titanium dioxide of Production Example 4 in place of the titanium dioxide of Example 1.

"Comparative Example 3"
A highly water-resistant W / O emulsified sunscreen cream was produced using the titanium dioxide of Production Example 5 in place of the titanium dioxide of Example 1.

"Comparative Example 4"
A highly water-resistant W / O emulsified sunscreen cream was produced using the titanium dioxide used in Production Example 1, which had not been surface-treated with a silicone compound, instead of the titanium dioxide.

Each of the sunscreen creams produced in Examples 1 and 2 and Comparative Examples 1 to 4 was stored at 50 ° C. for one month, and the discoloration preventing effect was visually observed. The results are shown in "Table 1".

[Table 1] ----------------------------------- [of ² per powder surface area 100m of silicon atoms Amount] [Discoloration] ---------------------------------------------------------------------- Example 1 1.25 × 10 ^-3 mol Discoloration No---------------------Example 2 1.43 x 10 ^-3 mol No color change--- −−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−−− Comparative Example 1 1.20 × 10 ⁻³ mol Yellow −−−−−−− −−−−−−−−−−−−−−−−−−−−−−−−−−−−− Comparative Example 2 1.00 × 10 ⁻³ mol Yellow yellow −−−−−−−−−−−− −−−−−−−−−−−−−−−−−−−−−−−−−−−−−−− Comparative Example 3 − Colored ------------------------------------------------------- Comparative Example 4-Yellow ---- ---------------------------- as shown in "Table 1", powder surface area of 100m ² per 1.
The sunscreen creams of Examples 1 and 2 of the present invention, which were surface-treated with a silicone compound so as to contain 25 × 10 ⁻³ mol or more of silicon atoms, did not cause discoloration, but the sunscreen creams of Comparative Examples 1 to 4 It was found that all the screen creams turned yellow and discoloration occurred.

“Example 3: W / O emulsified sunscreen cream” (% by weight) (1) purified water 35.5 (2) 1,3 butylene glycol 5.0 (3) octyl paramethoxycinnamate 5 0.0 (4) Oxybenzone 3.0 (5) 4-tertbutyl-4'methoxydibenzoylmethane 2.0 (6) Silicone-treated titanium dioxide of Production Example 6.0 (7) Squalane 35.5 (8) Glycerin diisostearate 3.0 (9) Organically modified montmorillonite 1.5 (10) Suitable amount of preservative (11) Suitable amount of fragrance (Production method) (1), (2) and (3) to (11) are mixed respectively. Heat and dissolve at 70 ° C. While gradually adding (1) and (2) to sufficiently mixed and dispersed (3) to (11), the mixture is emulsified using a homoxer. The emulsion was cooled using a heat exchanger to produce a W / O emulsified sunscreen cream. As a result of storage at 50 ° C. for one month, no discoloration occurred.

“Example 4: Sunscreen oil” (% by weight) (1) Octyl paramethoxycinnamate 3.0 (2) 4-tertbutyl 4′-methoxybenzoylmethane 1.5 (3) Production Example 1 Silicone treated titanium dioxide 2.0 (4) Liquid paraffin 63.0 (5) Cetyl octanoate 30.0 (6) Antioxidant appropriate amount (7) Perfume appropriate amount (Production method) (1) to (7) Each component was heated and stirred, sufficiently dissolved and stirred, and then cooled to produce a sunscreen oil. As a result of storage at 50 ° C. for one month, no discoloration occurred.

Example 5: Oily sunscreen gel (% by weight) (1) Octyl paramethoxycinnamate 2.5 (2) 4-tertbutyl 4'-methoxybenzoylmethane 1.0 (3) Production example 1. Silicone-treated titanium dioxide 2.0 (4) Liquid paraffin 72.0 (5) Olive oil 22.0 (6) Organically modified montmorillonite 5.0 (7) Antioxidant appropriate amount (8) Fragrance appropriate amount (9) ) Colorant appropriate amount (Production method) After taking a part of (4) and swelling (6),
Stir vigorously to disperse evenly. Inside (1) ~
The components (3), (5) and (7) to (9) were added and uniformly mixed to produce an oily sunscreen gel. 5
As a result of storage at 0 ° C. for one month, no discoloration occurred.

[0043]

According to the present invention, it is possible to provide an external preparation for skin containing a dibenzoylmethane compound excellent in stability without discoloration. In particular, by blending titanium dioxide as a dibenzoylmethane-based ultraviolet absorber and an ultraviolet ray blocking agent, a sunscreen cosmetic that can effectively prevent ultraviolet rays in the UV-A and UV-B regions can be provided.

Claims (4)

[Claims] 1. A powder containing a dibenzoylmethane compound and a powder that has been surface-treated with a silicone compound so as to contain 1.25 × 10 ⁻³ mol or more of silicon atoms per 100 m ^{2 of} powder surface area. An external preparation for skin characterized by the following. 2. The external preparation for skin according to claim 1, wherein the powder is a powder which has been subjected to a surface treatment by bringing a silicone compound into contact with the powder in a vapor form. 3. The method according to claim 1, wherein the dibenzoylmethane compound is 4-
The external preparation for skin according to claim 1 or 2, which is tert-butyl-4'-methoxydibenzoylmethane. 4. The powder according to claim 1, wherein the powder is fine titanium dioxide having an average particle diameter of 0.2 μm or less.
4. The external preparation for skin according to item 2 or 3.