JP3220301B2 - External preparation for skin - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a skin external preparation, and more particularly to a skin external preparation which contains silicon carbide powder, has a high UV protection effect, has no sticky feeling when used, and has a high moisturizing effect.

[0002]

2. Description of the Related Art In general, ultraviolet absorbers of organic compounds have problems in stability and safety. Therefore, conventionally, external skin preparations for cosmetics and the like for protecting ultraviolet rays include inorganic powders such as zinc oxide and titanium oxide. The body is blended.

[0003] However, inorganic powders such as titanium oxide and zinc oxide have a problem that when the content thereof is increased, the powder becomes white and the appearance after makeup is impaired. In addition, since these inorganic powders have high surface activity, it was necessary to reduce the activity by performing various surface treatments in order to stabilize the components.

On the other hand, water-soluble polyhydric alcohols are widely used in various external preparations for the purpose of retaining moisture in the skin. However, these water-soluble polyhydric alcohols have a strong sticky feeling when used and are not preferred in terms of sensuality. There was a problem that the duration of the moisturizing effect was short.

[0005]

Therefore, there has been a demand for the development of an external preparation for skin having an excellent UV protection effect, a good feeling of use and a high moisturizing effect.

[0006]

Under these circumstances, the present inventors have conducted intensive studies and as a result, have found that silicon carbide powder, which is generally used as an abrasive or a material for a chemical reaction vessel, has a high UV protection capability. It has been found that, because of its low surface activity, it has excellent stability as a compounding component, and it can be used to obtain an external preparation for skin having high transparency and stability and ultraviolet protection ability. In addition, since the silicon carbide powder has a high affinity with the water-soluble polyhydric alcohol, by using the silicon carbide powder and the water-soluble polyhydric alcohol together, the moisturizing effect is maintained for a long time, and there is no sticky feeling at the time of use. The present inventors have found that a skin external preparation can be obtained, and have completed the present invention.

That is, according to the present invention, the free carbon content is 0.3% by weight or less and the transition metal compound content is 0.2% by weight.
An object of the present invention is to provide a skin external preparation characterized by containing silicon carbide powder in an amount of not more than% by weight.

[0008] The present invention also relates to the present invention, wherein the free carbon content is 0.3
Not more than 0.2% by weight and a transition metal compound content of not more than 0.2% by weight
A skin external preparation characterized by containing the following silicon carbide powder and a water-soluble polyhydric alcohol.

The silicon carbide powder used in the present invention is not particularly limited, but a powder having a higher light transmittance in the visible light region is preferable because of less coloring and higher transparency. Therefore, those having a free carbon content of 0.3% by weight or less and a transition metal compound content of 0.2% by weight or less are preferable, and particularly those having a free carbon content of 0.1% by weight or less and a transition Those having a metal compound content of 0.1% by weight are preferred.

Here, the free carbon content is determined according to JIS-R-
It can be measured according to 61-24-1980.

[0011] Such high-purity silicon carbide selectively exhibits an absorption capacity in the ultraviolet region, furthermore has a small absorption in the visible region, and can be widely used as an ultraviolet absorbing material.

The crystal forms of silicon carbide are α-type, β-type and 2 type.
H, 4H, 6H, 8H, 15R, 3C type and the like are not particularly limited, but from the viewpoint of transparency in the visible light region, 2H, 4H,
The 6H type is preferred. In the present invention, one kind may be used alone, or two or more kinds having a crystal form may be mixed and used.

Further, the shape of the silicon carbide powder is not particularly limited, but is particularly preferably plate-like or spherical. Also,
The particle size is preferably in the range of 0.01 to 100 μm, particularly 0.1 to 50 μm, from the viewpoint of improving dispersibility, reducing the shielding area and enhancing the ultraviolet protection effect.

The method for producing the silicon carbide powder used in the present invention is not particularly limited, but the free carbon content is 0.3% by weight or less and the transition element metal compound content is 0.2% by weight or less. In order to obtain silicon carbide powder, the following known methods can be used.

That is, the transition metal compound may be removed from the silicon carbide raw material by acid treatment and free carbon may be removed by heating. At this time, as the acid, hydrochloric acid, oxalic acid, nitric acid,
Use hydrofluoric acid or the like or a mixed acid thereof, and heat at 15 to 9
What is necessary is just to carry out at 5 degreeC. Further, a method of heating and sublimating a silicon carbide raw material to grow a crystal (for example, Magazine “Vacuum”, Vol. 30, 1987, p. 52), and a method of synthesizing silicon and carbon raw materials by a gas phase method (for example, a magazine “Ceramics”) , 19 (1984), p. 478).

The silicon carbide powder thus obtained can be used as it is in the external preparation for skin of the present invention. However, in order to impart water repellency and oil repellency, methyl hydrogen polysiloxane, Silicone treatment with trimethylsiloxysilicic acid, methylpolysiloxane, etc., fluorine treatment with perfluoroalkyl phosphate, etc., and further surface treatment such as lecithin treatment, metal soap treatment, alkyl phosphate treatment, etc. can be used before use. .

The amount of silicon carbide powder in the external preparation for skin of the present invention can be arbitrarily selected according to the dosage form, but is preferably 0.1 to 50% by weight, particularly preferably 1 to 25% by weight.

Further, the skin external preparation of the present invention can impart a moisturizing effect by further blending a water-soluble polyhydric alcohol. Here, the water-soluble polyhydric alcohol is a water-soluble polyhydric alcohol containing two or more hydroxyl groups in a molecule, for example, ethylene glycol, propylene glycol, 1,3-butylene glycol, 1,4-butylene glycol, Dipropylene glycol, glycerin and diglycerin, triglycerin, polyglycerin such as triglycerin, glucose, maltose, maltitol, sucrose, fructose, xylitolose, sorbitol, maltotriose, threitol, erythritol, amylolytic sugar reducing alcohol, etc. No.

In the present invention, the water-soluble polyhydric alcohol may be used singly or as a mixture of two or more. The amount of the water-soluble polyhydric alcohol can be arbitrarily selected according to the dosage form. It is preferably from 1 to 75% by weight, particularly preferably from 1 to 25% by weight.

Further, the skin preparation for external use of the present invention may contain oils or surfactants usually used for cosmetics, external medicines and the like. As the oil agent preferably used here, for example, liquid paraffin, paraffin wax,
Hydrocarbons such as ceresin and squalane; beeswax, whale wax,
Waxes such as carnauba wax; olive oil, camellia oil, jojoba oil, fatty acids, higher alcohols and ester oils obtained by reacting them; and silicone oils.

As the surfactant, polyoxyethylene alkyl ether, polyoxyethylene fatty acid ester, polyoxyethylene sorbitan fatty acid ester, polyoxyethylene sorbitol fatty acid ester,
Polyoxyethylene hydrogenated castor oil alkyl sulfate, polyoxyethylene alkyl sulfate, alkyl phosphate, polyoxyethylene alkyl phosphate, fatty acid alkali metal salt, sorbitan fatty acid ester, glycerin fatty acid ester and the like are used.

Further, the skin external preparation of the present invention may further contain various optional components such as a viscosity modifier, a humectant, a preservative, and extenders such as mica, talc and kaolin.

The external preparation for skin of the present invention can be produced according to a conventional method, and can be made into various dosage forms such as lotion, emulsion, cream, ointment, aerosol cosmetic and oily foundation.

[0024]

Industrial Applicability Since the silicon carbide powder used in the present invention has an excellent UV protection effect and low surface activity, the skin external preparation of the present invention containing the same has an excellent UV protection effect and the stability of the components. It is excellent. In addition, since silicon carbide powder has excellent affinity with water-soluble polyhydric alcohol, the external preparation for skin of the present invention using silicon carbide powder and water-soluble polyhydric alcohol together has a long-lasting moisturizing effect and is sticky. Has no feeling and has a good feeling of use.

[0025]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples. In addition, a method for producing silicon carbide powder will be described as a synthesis example. The free carbon content and the transition element metal compound content were measured according to the method of JIS-R-61-24-1980.

Synthesis Example 1 α-Type Silicon Carbide Obtained by Acheson Method (Average Particle Size = 3.
5 μm, mixing ratio of polymorphs 6H and 4H is 20%: 80%)
Was immersed in an aqueous hydrochloric acid solution to remove the transition element metal compound. Further, heat treatment was performed at 700 ° C. for 1 hour in an air stream to remove free carbon. The obtained product had a free carbon content of 0.18% by weight and a transition element metal compound content of 0.1% by weight.
It was 5% by weight. The silicon carbide powder obtained in the silicon oil was kneaded so as to be 10% by weight, a coating film was formed on quartz glass, and a spectrophotometer (U4000 manufactured by Hitachi, Ltd.) was used.
) Was used to measure the transmittance at a wavelength of 200 to 700 nm. As a result, the transmittance in the visible light region is high (the transmittance at 500 nm is 78.5%), and the transmittance in the ultraviolet light region is low (3
(The transmittance at 00 nm was 21.3%), which proved to be excellent in selective ultraviolet absorption characteristics.

Synthesis Example 2 α-Form Silicon Carbide Obtained by Acheson Method (Average Particle Size = 0.
15 μm, mixing ratio of polymorphs 6H and 4H is 40%: 60%)
As in Synthesis Example 1, the transition element metal compound and free carbon were removed to obtain silicon carbide powder having a free carbon content of 0.06% by weight and a transition element metal compound content of 0.08% by weight. . The transmittance of this was measured using a spectrophotometer in the same manner as in Synthesis Example 1. As a result, the transmittance in the visible light region is high (the transmittance at 500 nm is 81.7%), the transmittance in the ultraviolet light region is low (the transmittance at 300 nm is 15.5%), and the selective ultraviolet absorption characteristics are excellent. It has been found.

Synthesis Example 3 β-type silicon carbide (average particle size = 0.02 μm, polymorph C) obtained by high-frequency plasma CVD as a gas phase method was heat-treated at 600 ° C. for 1 hour in an air stream to obtain free carbon. Was 0.09% by weight and a transition element metal compound was 0.05% by weight. The UV-absorbing capacity of this was measured using a spectrophotometer in the same manner as in Synthesis Example 1. As a result, the transmittance in the visible light region is high (the transmittance at 500 nm is 81.7%), the transmittance in the ultraviolet light region is low (the transmittance at 300 nm is 17.5%),
It was found that it had excellent selective ultraviolet absorption characteristics.

Example 1 (Lotion) A lotion having the following composition was prepared according to a conventional method. This lotion was not sticky and was a cosmetic having an excellent UV protection effect.

[0030]

Table 1 (Composition) (% by weight) Ethanol 30.0 Glycerin 5.0 Polyethylene glycol 1500 4.0 Polyoxyethylene oleyl ether (20E.O.) 1.0 Polyoxyethylene hydrogenated castor oil (30E.O.) ) 0.5 Silicon carbide powder (Synthesis example 2) 5.0 Fragrance 0.2 Purified water Balance

Example 2 (Emulsion) An emulsion having the following composition was prepared according to a conventional method. This emulsion was not sticky and was a cosmetic having an excellent ultraviolet protection effect.

[0032]

(Composition) (% by weight) Cetanol 1.0 Squalane 5.0 Olive oil 8.0 Jojoba oil 2.0 Polyoxyethylene hydrogenated castor oil (10E.O.) 1.0 Sorbitan monostearate 1.0 Silicon carbide powder (Synthesis example 2) 10.0 Butyl paraben 0.1 Methyl paraben 0.1 Ethanol 3.0 Glycerin 2.0 1,3-butylene glycol 2.0 Fragrance 0.1 Purified water Balance

Example 3 (Cream) A cream having the following composition was prepared according to a conventional method. This cream was not sticky and was a cosmetic having an excellent UV protection effect.

[0034]

(Composition) (% by weight) Stearic acid 2.0 Cetanol 1.0 Cholesterol 1.0 Squalane 10.0 Olive oil 5.0 Jojoba oil 5.0 Cetyl phosphate 0.5 Sorbitan monostearate 2.0 Poly Oxyethylene hydrogenated castor oil (40E.O.) 0.5 Silicon carbide powder (Synthesis example 2) 10.0 Butylparaben 0.1 Methylparaben 0.1 Glycerin 10.0 L-arginine 0.3 Fragrance 0.1 Purified water balance

Example 4 (Aerosol cosmetic) An aerosol cosmetic having the following composition was prepared according to a conventional method. This aerosol cosmetic was a cosmetic having an excellent ultraviolet protection effect.

[0036]

(Composition) (% by weight) Triclosan 0.01 Aluminum hydroxychloride 1.5 Talc 1.0 Silicon carbide powder (Synthesis example 3) 5.0 Isopropyl myristate 2.0 Perfume 0.2 Propellant Balance

Example 5 (Oil-based foundation) An oil-based foundation having the following composition was prepared according to a conventional method. This oily foundation was a cosmetic having an excellent ultraviolet protection effect.

[0038]

(Composition) (% by weight) Squalane 33.8 Octyldodecyl myristate 5.0 Microcrystalline wax 6.0 Silicon carbide powder (Synthesis example 1) 20.0 Kaolin 10.0 Talc 10.0 Color pigment 15 0.0 perfume 0.2

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Mikio Sakaguchi 1128-34 Nishihama, Wakayama-shi, Wakayama (56) References JP-A-4-364116 (JP, A) JP-A-5-97646 (JP, A) 63-126818 (JP, A) Patent 3093881 (JP, B2) (58) Fields investigated (Int. Cl. ⁷ , DB name) A61K ^7/ 00-7/50 CA (STN) REGISTRY (STN)

Claims (2)

(57) [Claims] (1) a free carbon content of 0.3% by weight or less;
An external preparation for skin, comprising a silicon carbide powder having a transition metal compound content of 0.2% by weight or less. 2. When the free carbon content is 0.3% by weight or less,
A skin external preparation comprising a silicon carbide powder having a transition metal compound content of 0.2% by weight or less and a water-soluble polyhydric alcohol.