JP2005239668A - Sunscreen composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a sunscreen composition instantaneously preventing dry skin caused by metal oxide powder having UV-scattering effect and giving good feeling in use. <P>SOLUTION: This sunscreen composition is free from phospholipids and sterin and contains 1-20 mass% urea based on the total mass of the sunscreen composition. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to sunscreen compositions. More specifically, the present invention relates to a sunscreen composition that exhibits an immediate prevention effect against the occurrence of skin roughness caused by the metal oxide powder having an ultraviolet scattering effect and has a good feeling of use.

  It is known that organic ultraviolet absorbers used in sunscreen compositions have problems in terms of stability (decomposition after ultraviolet absorption) and safety (skin irritation caused by decomposition products). Therefore, sunscreen compositions that are formulated with no organic UV absorbers are commercially available for children and people with sensitive skin.

In such an organic ultraviolet absorber-free sunscreen composition, a metal oxide powder having an ultraviolet scattering effect such as titanium oxide or zinc oxide is blended as an inorganic ultraviolet scattering agent. Inorganic ultraviolet scattering agents are less likely to decompose than organic ultraviolet absorbers, and there are fewer problems in stability and safety.
However, when the blending amount of the metal oxide powder is increased in order to enhance the ultraviolet scattering effect, there is a shortage of sebum and moisture in the skin, and as a result, there is a problem that the skin becomes soft.

As an attempt to solve such a problem, a conventional sunscreen composition contains phospholipids and sterins (see, for example, Patent Document 1).
In addition, there is a mixture of urea and isotype or anteisotype fatty acid cholesterol ester (see, for example, Patent Document 2).
In these sunscreen compositions, phospholipids and sterins (including isotype or anteisoform fatty acid cholesterol esters) are used as essential components in order to solve the above problems.

JP 2001-2545 A Japanese Patent Laid-Open No. 11-60432

Phospholipids and sterins are lipids that are solid at room temperature contained in sebum and keratinocyte lipids, and have the property of forming highly viscous solutions when dissolved in other oily components.
When applied, the phospholipids and sterins can cover the skin, form a barrier, and suppress (cover) water evaporation from the inside of the skin. And, the moisture transpiration suppression state is maintained for a long period of time, and moisture that could not be transpiration is accumulated in the barrier, and the moisture deficiency state of the skin caused by the metal oxide powder is eliminated, thereby improving the roughness. . Therefore, phospholipids and sterins have an effect of improving the slow-acting effect on the skin roughness caused by the metal oxide powder, but do not have an effect of preventing the occurrence of the roughness.
Therefore, the conventional sunscreen compositions as described above can exhibit an effect of improving skin roughness when used for the purpose of preventing sunburn for a long period of time at leisure in the sea and mountains, but the occurrence of roughness It cannot be prevented. In addition, when used for the purpose of preventing sunburn for a short period of time, it is not possible to exhibit a sufficient effect of improving the bulkiness.
On the other hand, increasing the amount of phospholipids and sterols with the aim of immediate moisture transpiration suppression by covering will cause a decrease in the feeling of use such as “badness” and “stickiness” due to physical properties as lipids, It was a problem.

  Therefore, the present invention exhibits an immediate prevention effect against the occurrence of skin roughness due to the metal oxide powder having an ultraviolet scattering effect (that is, no skin roughness occurs even in a short-time application state), and An object of the present invention is to provide a sunscreen composition having a good feeling of use and “not sticky” and “not sticky”.

As a result of earnest research after finding the above problems, the present inventors solved the problem by blending a specific amount of urea in a sunscreen composition using a metal oxide powder having an ultraviolet scattering effect. As a result, the present invention has been completed.
That is, the present invention
(1) A sunscreen composition comprising a metal oxide powder having an ultraviolet scattering effect and 1 to 20% by mass of urea with respect to the total mass of the sunscreen composition, phospholipids and sterols A sunscreen composition characterized in that it does not contain
(2) The sunscreen composition according to the above (1), wherein the blending amount of the metal oxide powder having an ultraviolet scattering effect is 1 to 30% by mass relative to the total mass of the sunscreen composition;
(3) The sunscreen composition according to the above (1) or (2), comprising a metal oxide powder having an ultraviolet scattering effect selected from the group consisting of titanium oxide, zinc oxide, zirconium oxide and cerium oxide;
(4) The sunscreen composition according to any one of (1) to (3) above, which includes a surface-treated metal oxide powder having an ultraviolet scattering effect; and (5) an emulsion. The sunscreen composition according to any one of (1) to (4).

  The sunscreen composition of the present invention, as shown in the examples described later, exhibits an immediate prevention effect against the occurrence of skin roughness due to metal oxide powder having an ultraviolet scattering effect, and is used. It has the advantage of good feeling (“good” and “not sticky”). Therefore, it can be preferably used for a short-term sun protection application, which is impossible with a conventional sunscreen composition containing an inorganic ultraviolet scattering agent.

The present invention is described in detail below.
The “metal oxide having an ultraviolet scattering effect” is not particularly limited as long as it is a metal oxide having an ultraviolet scattering effect that can be used as a sunscreen composition. Specific examples include titanium oxide, zinc oxide, zirconium oxide, cerium oxide, and the like.

The “metal oxide having an ultraviolet scattering effect” is a known surface treatment such as fluorine compound treatment, silicone treatment, silicone resin treatment, pendant treatment, silane coupling agent treatment, titanium coupling agent treatment, oil agent treatment, N -It may be subjected to acylated lysine treatment, polyacrylic acid treatment, metal soap treatment, inorganic compound treatment, plasma treatment, mechanochemical treatment and the like. By applying these surface treatments, it is possible to produce a sunscreen composition in which the powders do not aggregate and are uniformly dispersed.
As the surface treatment, a water repellent treatment with at least one substance selected from the group consisting of silicone, silane, fluorine compound and metal soap is preferable.

The particle size of the powder of “metal oxide having an ultraviolet scattering effect” is not particularly limited as long as it can be used as a sunscreen composition. For example, the primary particle size is 0.001 to 100 μm. Preferably, 0.005 to 0.1 μm, particularly preferably 0.01 to 0.05 μm can be used.
The primary particle size refers to the particle size of the metal oxide powder that is not aggregated.

  The shape of the powder of “metal oxide having ultraviolet scattering effect” is not particularly limited as long as it can be used as a sunscreen composition.

  Specific examples of the above physical properties include silicone surface-treated fine particle titanium oxide (trade name: Maxlite TS-04-D, manufacturer: Showa Denko KK, primary particle size: 0.038 μm) and silicone surface-treated fine particles. Examples thereof include zinc oxide (trade name: ZnO-350Si (4) G, manufacturer name: Sumitomo Osaka Cement, primary particle size: 0.01 to 0.03 μm), and the like.

  The “metal oxide having an ultraviolet scattering effect” is a known compound, and can be easily obtained on the market or synthesized.

  The “metal oxide having an ultraviolet scattering effect” may be used alone or in combination of two or more. When two or more types are used in combination, it is preferable in that UVA and UVB are widely scattered. Examples of the combination include a combination of silicone surface-treated fine particle titanium oxide and silicone surface-treated fine particle zinc oxide. Since titanium oxide has a high UVB scattering effect and zinc oxide has a high UVA scattering effect, a higher sunscreen effect can be obtained by employing the above combination.

  The amount of the powder of “metal oxide having an ultraviolet scattering effect” is not particularly limited as long as a sufficient sunscreen effect can be obtained, but 1 to 30 mass relative to the total mass of the sunscreen composition. %, Preferably 5 to 20% by mass, particularly preferably 10 to 17% by mass. When the blending amount of the powder of “metal oxide having an ultraviolet scattering effect” is 1 to 30% by mass with respect to the total mass of the sunscreen composition, a sufficient sunscreen effect can be obtained as the sunscreen composition. it can.

“Urea” is a water-soluble substance that exists in the skin and can hydrate and retain moisture in the skin.
Although the present invention is not bound by a specific theory, the sunscreen composition of the present invention that contains urea can immediately exhibit an anti-caking effect because of the water retention ability of urea. Conceivable. That is, as soon as urea is applied to the skin, the moisture in the skin is hydrated and retained, so that the lack of moisture due to the metal oxide powder does not occur, and as a result, the skin does not become bulky. Therefore, the sunscreen composition of the present invention can immediately exert an effect of preventing skin roughness immediately after application.
Urea forms a low-viscosity free-flowing liquid when dissolved in a blending amount range described later. Therefore, the sunscreen composition of the present invention can have an excellent feeling of use such as “good spread” and “no stickiness”.

The compounding quantity of "urea" is 1-20 mass% with respect to the total mass of a sunscreen composition, Preferably it is 5-15 mass%, Most preferably, it is 8-12 mass%. When the blending amount of urea is 1 to 20% by mass with respect to the total mass of the sunscreen composition, an immediate prevention effect against the occurrence of skin roughness due to the metal oxide powder having an ultraviolet scattering effect is exhibited. In addition, a sunscreen composition having a good feeling of use can be obtained.
“Urea” is a known compound, and any commercially available product or synthesized product can be used in the present invention.

  The term “phospholipid” in the term “not including phospholipids and sterins” includes phosphatidylcholine, phosphatidyltriethanolamine, phosphatidylserine, phosphatidylglycerol, phosphatidylinositol, sphingophospholipids, and the like, and the like. Composition (eg, soybean lecithin, egg yolk lecithin) and hydrogenated products thereof.

  “Sterins” include cholesterol, dihydrocholesterol, cholesteryl stearate, cholesteryl hydroxystearate, macadamia nut oil fatty acid cholesteryl, β-sitosterol, stigmasterol, campesterol, ergosterol, 5-dihydroergosterol and phytosterol, and These fatty acids (including iso-type fatty acids and anteiso-type fatty acids) esters and the like.

  Unlike urea, phospholipids and sterins cannot exhibit the effect of preventing skin roughness due to metal oxide powder having an ultraviolet scattering effect, and further, it takes a long time to improve the roughness, Not suitable for short-term sun protection applications. Therefore, it is not included in the sunscreen composition of the present invention.

In addition to the above components, the sunscreen composition of the present invention includes oils, powders (pigments, dyes, resins), surfactants, thickeners used in ordinary cosmetics, quasi drugs, and pharmaceutical skin external preparations. Ingredients such as agents, preservatives, perfumes, moisturizers, physiologically active ingredients, salts, solvents, antioxidants, pH adjusters, etc. (however, excluding phospholipids and sterins) can be appropriately blended.
Examples of the oil agent include silicone oil, hydrocarbon, fatty acid ester and the like.
Examples of the powder (pigment, dye, resin) include bengara, lake dye, and cellulose powder.
Examples of the surfactant include glyceryl ether, glycerin fatty acid ester, polyoxyethylene hydrogenated castor oil, and the like.
Examples of the thickener include dextrin palmitate, bentonite, xanthan gum and the like.
Examples of preservatives include parabens, benzoic acid, benzoates and the like.
Examples of the fragrances include natural fragrances and synthetic fragrances.
Examples of the humectant include polyhydric alcohol, amino acid, hyaluronic acid and the like.
Examples of physiologically active ingredients include vitamins and amino acids.
Examples of the salts include sodium chloride, magnesium sulfate, and zinc sulfate.
Examples of the solvent include water, ethanol, polyhydric alcohol and the like.
Examples of the antioxidant include dibutylhydroxytoluene, isopropyl gallate, tocopherol acetate and the like.
Examples of the pH adjuster include amines, organic acids (salts), sodium hydroxide and the like.

The sunscreen composition of the present invention can be used in various forms such as liquid, emulsion, cream, and gel.
Moreover, the sunscreen composition of the present invention can be used as cosmetics, pharmaceuticals, quasi drugs and the like.

  The sunscreen composition of the present invention can be produced by a general method for producing an inorganic ultraviolet scattering agent-containing sunscreen composition.

  EXAMPLES Next, although an Example is given and this invention is demonstrated further in detail, this invention is not limited by this.

[Example 1] Sunscreen emulsion containing urea A sunscreen emulsion having the composition shown in Table 1 below was produced.
As a metal oxide powder (component (C)) having an ultraviolet scattering effect, silicone surface-treated fine particle titanium oxide (trade name: Maxlite TS-04-D, manufacturer: Showa Denko Co., Ltd., primary particle diameter: 0.038 μm) and silicon surface-treated fine particle zinc oxide (trade name: ZnO-350Si (4) G, manufacturer name: Sumitomo Osaka Cement, primary particle size: 0.01 to 0.03 μm) were used.
Commercial products were used for urea (component (D)) and other components.
A sunscreen emulsion was prepared according to the following steps 1-2.
1. (A) The component is heated and dissolved at 80 ° C., and the component (C) is dispersed in this (with a homomixer at 5000 rpm for 5 minutes), and
2. A step of adding the components (B) and (D) heated and dissolved at 80 ° C. to the obtained dispersion and mixing (mixing with a homomixer at 7000 rpm for 5 minutes and 5000 rpm for 20 to 30 minutes).

[Comparative Example 1] Sunscreen emulsion containing no urea Sunscreen emulsion having the composition shown in Table 1 by the same steps as in Example 1 except that the component (D) urea was not blended in Step 2 above. Manufactured.

[Comparative Example 2] A sunscreen emulsion containing phospholipids and sterins instead of urea. In step 1, component (A) is used together with component (E) (cholesterol and purified soybean lecithin), and in step 2, component (D) is used. A sunscreen emulsion having the composition shown in Table 1 was produced by the same process as in Example 1 except that no urea was used. Cholesterol is a component corresponding to sterols, and purified soybean lecithin is a component corresponding to phospholipids.
When the total amount of cholesterol and purified soybean lecithin was blended in the same amount as that of urea in Example 1, it could not be formulated as a sunscreen composition.

[Comparative Example 3] A sunscreen emulsion containing phospholipids and sterins instead of urea, using (E) component (fatty acid cholesterol ester mixture and ceramide) together with (A) component in Step 1 above, and (D ) A sunscreen emulsion having the composition shown in Table 1 was produced in the same manner as in Example 1 except that the component urea was not used. The fatty acid cholesterol ester mixture is a component corresponding to sterins.
When the total amount of the fatty acid cholesterol ester mixture and ceramide was the same as that of urea in Example 1, it could not be formulated as a sunscreen composition.

[Comparative Example 4] Sunscreen emulsion containing phospholipids and sterins in addition to urea In addition to component (A) in Step 1, component (E) used in Comparative Example 3 (fatty acid cholesterol ester mixture and ceramide) was used. A sunscreen emulsion having the composition shown in Table 1 was produced in the same manner as in Example 1 except that.

表中の数値は日焼け止め乳液の総質量に対する質量％値を示す。 Table 1: Composition of sunscreen emulsions of Example 1 and Comparative Examples 1-4

The numerical value in a table | surface shows the mass% value with respect to the total mass of sunscreen emulsion.

Sensory evaluation of sunscreen emulsions of Examples and Comparative Examples The sunscreen emulsions of Examples and Comparative Examples were applied with “goodness of spread”, “feel of stickiness” immediately after application, and “moist feeling of skin 3 hours after application” Was subjected to a sensory evaluation.
Among these sensory evaluations, “goodness of spread” and “stickiness” are indicators of “goodness of use”, and “moistness” means “skin with metal oxide powder having an ultraviolet scattering effect” It is an index of “immediate prevention effect against the occurrence of roughness”.
Each sensory evaluation was performed based on the average score of the five-step evaluation according to the following evaluation criteria of 20 evaluation panels. The results are shown in Table 2.

Evaluation criteria 5: Good 4: Slightly good 3: Normal 2: Slightly bad 1: Bad

Table 2. Sensory evaluation of sunscreen emulsions of Example 1 and Comparative Examples 1-4

Comparing Example 1 and Comparative Example 1 with respect to “moist feeling”, it is understood that urea provides an “immediate prevention effect against the occurrence of skin roughness due to powder of metal oxide having an ultraviolet scattering effect”. The
Further, when Example 1 and Comparative Examples 2 to 3 are compared (or Comparative Example 4 and Comparative Example 3 are compared), phospholipids and sterins have “the skin caused by the metal oxide powder having an ultraviolet scattering effect”. It is understood that an “instant preventive effect against sacrificial occurrence” cannot be obtained.

Comparing Example 1 and Comparative Examples 2 to 4 with respect to “goodness of spread” and “tackiness” , by blending urea, an excellent “use feeling” that cannot be obtained by blending phospholipids and sterins. It is understood that it is obtained.

  As described above, by adding urea, a sunscreen composition that exhibits an immediate prevention effect against the occurrence of skin roughness caused by the metal oxide powder having an ultraviolet scattering effect and has a good feeling of use. It is understood that it is obtained.

  The sunscreen composition of the present invention can be used as a sunscreen.

Claims (5)

A sunscreen composition comprising:
Metal oxide powder having an ultraviolet scattering effect, and
Containing 1-20% by weight of urea with respect to the total weight of the sunscreen composition;
A sunscreen composition characterized by not containing phospholipids and sterins.   The sunscreen composition of Claim 1 whose compounding quantity of the powder of the metal oxide which has an ultraviolet-ray scattering effect is 1-30 mass% with respect to the total mass of a sunscreen composition.   The sunscreen composition according to claim 1 or 2, comprising a metal oxide powder having an ultraviolet scattering effect selected from the group consisting of titanium oxide, zinc oxide, zirconium oxide and cerium oxide.   The sunscreen composition according to any one of claims 1 to 3, comprising a surface-treated metal oxide powder having an ultraviolet scattering effect.   The sunscreen composition according to any one of claims 1 to 4, which is an emulsion.