JPS6137711A - Cosmetic - Google Patents

Abstract

PURPOSE:A cosmetic, containing fine particulate zinc oxide powder having improved dispersion stability and ultraviolet light protective effect and further anti- inflammatory and germicidal effect without whitening when applied to the skin. CONSTITUTION:A cosmetic obtained by forming zinc oxide into the particles, and incorporating the resultant fine particulate powder having 10-200Angstrom , preferably 50-100Angstrom particle diameters in a comsmetic base. The fine particulate powder is obtained by mechanical pulverization, etc., but preferably colloidal particles of zinc sulfate or zinc chloride in a hydrosol prepared in an aqueous solution are converted into lipophilic particles with an anionic surfactant, and flushed with an organic solvent. The above-mentioned solvent is then removed by drying to give the above-mentioned powder from the viewpoint of easy production, uniformity of particle diameter of the fine particulate powder and dispersibility in the cosmetic base.

Description

Detailed Description of the Invention [Industrial Field of Application] The present invention relates to a cosmetic, more specifically, a cosmetic containing fine-particle zinc oxide powder, which has good dispersion stability and has a transparent appearance when applied to the skin. The present invention relates to an excellent cosmetic that does not become whitish due to its properties, has an ultraviolet ray prevention effect, and also has anti-inflammatory and sterilizing effects.

[Prior Art] Conventionally, powders blended into cosmetics generally have a particle size of 0.5.
The smallest particle size is about 300 μm.
Only about 400 titanium oxides were known (Japanese Patent Publication No. 47-42502).

[Problems to be Solved by the Invention] If the particle size of the blended powder is about 300 to 400 or more as described above, when applied to the skin, whitishness will be noticeable and it will look unnatural. That is undeniable. For this reason, this whitishness has been a major hindrance when trying to incorporate powder into cosmetics to provide UV protection or give a refreshing feel to the skin.

In view of the current situation, the inventors of the present invention focused on zinc oxide and, as a result of intensive study, discovered that the above-mentioned drawbacks could be solved by making this material into fine particles and blending it into a cosmetic base.Thus, the present invention has been achieved. That's what happened.

[Means for Solving the Problems] That is, the present invention is a cosmetic characterized by containing fine-particle zinc oxide powder.

Hereinafter, the configuration of the present invention will be explained in detail.

The fine particle zinc oxide powder used in the present invention has a particle size of 10 to 200.
It is human microparticle zinc oxide powder, which can also be obtained by mechanical grinding, etc., but it is easy to manufacture, has good dispersibility of the obtained microparticle powder in cosmetic bases, and has a uniform particle size. The colloidal particles in the hydrosol of zinc sulfate or zinc chloride prepared in an aqueous solution are converted to lipophilic form with an anionic surfactant, then flushed with an organic solvent, and then the organic solvent is removed by drying. Particularly preferred are finely divided zinc oxide powders. The above colloid sol (hereinafter,
The particle size of the fine-particle zinc oxide powder obtained through the sol method is in the range of 10 to 200 particles, generally in the range of 50 to 100 particles.

The sol method will be explained in more detail.

In this method, first, an aqueous sodium carbonate solution is added to an aqueous solution of zinc chloride or zinc sulfate to form a hydrosol. The concentration of zinc chloride or zinc sulfate aqueous solution is about 0.1 to 1.0 mol, the concentration of sodium carbonate aqueous solution is about 0.2 to 1.0 mol, and the ratio of zinc chloride or zinc sulfate aqueous solution: sodium carbonate aqueous solution is by weight 1:1
That's about it.

Next, an anionic surfactant is added to make the hydrosol lipophilic. The anionic surfactants used are sodium alkylbenzenesulfonate, sodium lauryl sulfate, potassium lauryl sulfate, triethanolamine ether alkyl sulfate, funnel oil, sodium dialkyl sulfosuccinate, sodium di-ethylhexyl sulfosuccinate, and sodium lauryl sulfate. Sodium polyethylene glycol sulfosuccinate, sodium alkyl ether sulfate, polyoxyethylene (hereinafter referred to as
POE) sodium alkyl sulfate, N-balmitoyl aspartate ditriethanolamine, sodium coconut oil fatty acid methyltauride, sodium myristoylmethyltaurate, sodium lauryl methyltauride, sodium lauroyl glutamate, sodium oxidized coconut oil fatty acid glycerol sulfate, stearoyl Disodium glutamate, sodium myristoyl glutamate, POE sodium alkyl phenyl ether sulfate,
POE alkyl sulfate triethanolamine, sodium lauroyl sarcosine, sodium caseinate, sodium palmitate, sodium laurate, POE cured castor shimaleate, especially sodium alkylbenzene sulfonate, sodium lauryl sulfate, potassium lauryl sulfate, Alkyl sulfate triethanolamine ethers are preferred. The amount of anionic surfactant added varies depending on the ratio of zinc chloride or zinc sulfate to sodium carbonate, but it is generally selected within the range of 0.05 to 0.15 l per mol of zinc chloride or zinc sulfate. Good.

In the sol method according to the present invention, by appropriately selecting the balance between hydrophilicity and lipophilicity of the anionic surfactant, the obtained fine particle zinc oxide powder is adjusted to be either hydrophilic or lipophilic. be able to. For example, when blending fine-particle zinc oxide powder into aqueous-based cosmetics, sodium lauryl sulfate is used as an anionic surfactant.
Hydrophilic fine particle zinc oxide powder can be obtained by using potassium lauryl sulfate, alkyl sulfate triethanolamine ether, etc. Furthermore, when sodium alkylbenzenesulfonate or the like is used as an anionic surfactant, lipophilic fine particle zinc oxide powder can be obtained, which is suitable for blending into oil-based cosmetics.

The lipophilized hydrosol is then flushed with an organic solvent. Any organic solvent may be used as long as it dissolves the anionic surfactant. For example, xylene, toluene, penzene, or a mixed solvent thereof is used. The amount of the organic solvent is selected within a range of about 0.5 to 1.0 times the weight ratio of the hydrosol solution.

The organosol thus obtained is dried to separate fine particles of zinc oxide powder. There are no particular restrictions on the drying method, and any conventional method may be used.

In the present invention, the fine particle zinc oxide powder is 0.0% of the total amount of the cosmetic. -5 to 100% by weight, preferably 10% by weight or more from the viewpoint of UV protection effect, and 50% by weight or more from the viewpoint of giving a refreshing effect to the skin.

The dosage form of the cosmetic containing the fine-particle zinc oxide powder of the present invention is arbitrary, and broadly includes powder-based, solubilized-based, emulsified-based, powder-dispersed-solubilized, powder-dispersed-emulsified, powder-dispersed oil-based, etc. You can take it.

Applications are arbitrary, including facial cosmetics such as lotions, emulsions, creams, and cosmetic oils, as well as foundations,
It can be used in a wide range of cosmetics, including non-camping cosmetics such as powder, lipstick, blush, and eye shadow.

[Effects of the Invention] The cosmetic containing fine-particle zinc oxide powder according to the present invention has good transparency, so when applied to the skin, there is no whitish appearance, and it has an excellent UV protection effect, leaving a light feeling on the skin. It gives a pleasant feel when used, and also has good dispersion stability in cosmetic bases. Furthermore, since it is a powder, there is no need to worry about skin irritation or allergies, which is the case with liquid UV absorbers. It is a cosmetic with good safety.

[Example 2] Next, an example of manufacturing a fine-particle zinc oxide powder of the present invention and an example in which the fine-particle zinc oxide powder was blended into a cosmetic will be shown. The present invention is not limited thereby.

Production Example 1 A 0.1M aqueous sodium carbonate solution is added to a 1M aqueous zinc chloride solution at a weight ratio of 1:1. Addition rate is 25d/+n
The ratio was set as in. After stirring for 30 minutes, a white hydrosol was obtained. 0.15 M of sodium alkylbenzenesulfonate was added to make the sol lipophilic, and then 254 ml of xylene was added for flushing to obtain a white organosol. This product was dried under reduced pressure and xylene was distilled off to obtain 1 g of fine particle zinc oxide powder having a particle size of 70 to 100 particles. This fine-particle zinc oxide powder is lipophilic and suitable for blending into oil-based cosmetics.

Production Example 2 Hydrophilic fine-particle zinc oxide powder was obtained in the same manner as Production Example 1 except that sodium alkylbenzenesulfonate in Production Example 1 was replaced with sodium lauryl sulfate. This product is suitable for blending into aqueous cosmetics.

Example 1 (lotion) ■ Glycerin 3.0% by weight ■ Propylene glycol 2.0 ■ Oleyl alcohol
0.1 ■ POE (20) Sorbitan monolaurate 2.0 ■ Ethanol 10.0 ■ Fragrance
0.1 ■ Dye
Volume ■Fine particle zinc oxide powder (obtained in Production Example 2) 1.0 ■Water Add ■■ to the remaining ■ and dissolve (aqueous phase). Dissolve ■■■■■ in ■ (ethanol part). An ethanol portion was added to the aqueous phase for solubilization to obtain a lotion. The resulting lotion has a light feel, does not leave a white flaky appearance when applied to the skin, has good transparency, and has UV protection effects.
It also had excellent anti-inflammatory effects on the skin. Furthermore, because the particle size of the fine zinc oxide powder was small, the dispersibility was good even without adding a thickener or the like.

Example 2 (Sunscreen cream) ■Stearic acid 10.0% by weight ■Stearyl alcohol 4.0 ■Butyl stearate 6.0 ■Glyceryl monostearate (self-emulsifying type) 2.0 ■Fragrance appropriate amount ■Propylene glycol 10.0 ■ Glycerin
3.0 ■ Potassium hydroxide
0.4 ■ Fine particle zinc oxide powder (obtained in Production Example 2) 4.0 [Phase] Water The remainder [Phase] ■■
Add ■■ and dissolve and keep at 70°C (aqueous phase). ■■■■
Dissolve (1) and keep at 70°C (oil phase).

The oil phase was added to the water phase, emulsified, and cooled to obtain cream. The resulting cream had particularly excellent UV protection effects.

Example 3 (Sunscreen lotion) ■Stearic acid 2.0% by weight■Cetanol 1.5■Vaseline
3.0■Liquid paraffin 8
．． 0 ■ POE (10) monooleic acid ester 2.0 ■ Fragrance appropriate amount ■ Glycerin 2.0 ■ Propylene glycol 5.0 ■ Triethanolamine
1.0 [Phase] Fine particle zinc oxide powder (obtained in Production Example 2) 5.5 ■Water ■■■ [Phase] is added to the remaining ■ and melted and kept at 70°C (water phase). ■■■■■■ is dissolved and kept at 70°C (oil phase).

The oil phase was added to the water phase, emulsified, and cooled to obtain a milky lotion.

The obtained emulsion has particularly excellent UV protection effects and has a light feel upon use.Example 4 (Foundation Silin) ■Stearic acid 2.8% by weight ■Propylene glycol monostearate 2. 8 ■ Glyceryl monostearate (self-emulsifying type) 2.8 0 Liquid paraffin 24.6 ■ Triethanolamine 1.4 ■ Propylene glycol
15.0 ■ Fine particle zinc oxide powder (obtained in Production Example 1) 6.0 ■ Iron oxide red 1.5 ■ Iron oxide yellow
2.5 [Phase] Fragrance
Appropriate amount ■ Preservative Appropriate amount @ water Add ■■■ to the remaining @ and dissolve and keep at 70℃ (water phase) ■■
■■ [Phase] Dissolve ■■ and disperse ■■■ in it at 70°C.
(oil phase). The oil phase was added to the water phase, emulsified, and cooled to obtain a foundation.

Example 5 (white powder) ■Talc 10.2% by weight■Titanium oxide 1.0■Kaolin
10.0 ■ Fine particle zinc oxide powder (obtained in Production Example 1) 77.0 ■ Iron oxide red yellow black 1.8 ■ Iron oxide yellow
2.5 ■Fragrance A white powder was obtained by mixing appropriate amounts of the above components. When applied to the skin, this product had good transparency, did not appear whitish, and had an excellent makeup-reducing effect. In addition, the UV protection effect was sufficient.

Claims (4)

[Claims] (1) A cosmetic characterized by containing fine-particle zinc oxide powder. (2) The cosmetic according to claim (1), wherein the fine particle zinc oxide powder has a particle size of 10 to 200 Å. (3) The cosmetic according to claim (1), wherein the fine particle zinc oxide powder has a particle size of 50 to 100 Å. (4) Fine-particle zinc oxide powder is prepared in an aqueous solution by converting colloidal particles in a hydrosol of zinc sulfate or zinc chloride into lipophilic form with an anionic surfactant, then flushing with an organic solvent, and then flushing with an organic solvent. Claim No. 1, which is a fine particle zinc oxide powder obtained by drying and removing
Cosmetics according to any one of paragraphs ) to (3).