JPS61215317A - External agent for skin - Google Patents

Abstract

PURPOSE:To provide an external agent for skin, composed of a specific ultraviolet absorber in combination with an oil having an iodine value of higher than a specific level, having improved compatibility to base, preventing the deterioration caused by the precipitation of crystals and having excellent ultravioletshielding effect and high quality. CONSTITUTION:The objective agent can be produced by adding an oil having an iodine value of >=70 (e.g. drying oil such as linseed oil, nondrying oil such as sesame oil, fish oil such as sardine oil, etc.) to a dermatic agent for external use containing preferably 0.01-10% 4-(1,1-dimethylethyl)-4'- methoxydibenzoylmethane as an ultraviolet absorber capable of absorbing sunlight, especially ultraviolet ray having relatively long wavelength and harmful to the skin (UV-A). the amount of the oil is >=1/2 of the UV-absorber. The obtained external agent for skin has improved compatibility of the above UV- absorber to the base of the external agent and excellent ultraviolet-absorbing effect and quality and is storable stably for a long period with little deterioration.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention provides excellent results by blending 4-(1,1-dimethylethyl)-4°-methoxydibenzoylmethane with an oil having an iodine value of 7o or more. This topic relates to external skin preparations that have ultraviolet protection effects and excellent quality.

[Prior Art] It is known that sunlight not only causes sunburn, but also accelerates skin aging due to the sunburn.

There are many external skin preparations that are designed to protect against sunlight, but all of them contain powder that mainly protects the skin from the sun's rays.
Some methods used scattering techniques, or some contained substances such as salicylic acid derivatives and aminobenzoic acid derivatives that absorb only ultraviolet rays with relatively short wavelengths called UV-B.

[Problems to be solved by the invention] 4-(1,1-dimethylethyl)-4°-methoxydibenzoylmethane is harmful to sunlight, especially to the skin.
In recent years, it has been attracting attention as a substance called VA that absorbs relatively long wavelength ultraviolet rays, but it has poor compatibility with the base of external skin preparations, and even if it is incorporated into external skin preparations in a dissolved state, it has a relatively short lifespan. It often precipitates as crystals over time.

If it precipitates in the form of crystals, it goes without saying that the quality of the external skin preparation will be significantly impaired, and the originally intended ultraviolet absorbing ability will not be achieved.

[Means for Solving the Problems] In view of the above circumstances, the inventor has conducted extensive research and has found 4-(1)
, 1-dimethylethyl)-4°-methoxydibenzoylmethane and an oil with an iodine value of 70 or more,
We have completed the present invention by discovering that it is possible to obtain an external skin preparation that not only has excellent ultraviolet absorption effects but also excellent long-term stability and is less likely to deteriorate in quality.

That is, the present invention provides an external preparation for skin that has an excellent ultraviolet absorption effect and excellent quality.

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

4-(1,1-dimethylethyl)- used in the present invention
4°-Methoxydibenzoylmethane is disclosed in JP-A-55-6
It is manufactured by the method shown in No. 6535 and is supplied by Sibodan Co., Ltd. under the trade name "Pulsol 1789."

The amount to be added to the skin external preparation is arbitrary depending on the expected ultraviolet absorption effect, but if the amount is extremely large, the amount of the skin external preparation base will be reduced, which is not preferable. Preferably it is 0.01 to 10%. If it is less than 0.01%, the UV absorption effect is small and the original purpose cannot be achieved.
If it exceeds 10%, the amount of the skin external preparation base will be reduced and the quality of the skin external preparation itself will be impaired.

In addition, oils with an iodine value of 70 or more that are blended for the purpose of exhibiting the effects of the present invention include, for example, vegetable oils belonging to drying oils such as linseed oil, tung oil, soybean oil, safflower oil, walnut oil,
Eno oil, evening primrose oil, cherry kernel oil, grapeseed oil, etc., non-drying oils such as sesame oil, rapeseed oil, cottonseed oil, bran oil, wheat germ oil, etc., or avocado oil, olive oil, camellia oil, macadamia nut oil, etc., and fish oil. Famous examples include sardine oil, mackerel oil, herring oil, cod liver oil, and oyster oil.

The iodine value of these oils, for example, linseed oil, is 168-
190, soybean oil 114-138, safflower oil 12
2-150, rapeseed oil 94-107, cottonseed oil 90-
121, olive oil 75-90, camellia oil 73-8
7. Sardine oil is 136-195, herring oil is 99-11
9, etc.

Of the free fatty acids derived from these fats and oils, fatty acids with an iodine value of 70 or higher, such as oleic acid, palmitooleic acid, linoleic acid, lylunic acid, eleostearic acid, furiric acid, arachidonic acid, eicosapentaenoic acid, etc. Also included.

One or more of these oils may be blended, but the amount blended for the purpose of exhibiting the effects of the present invention is 4-(1
, 1-dimethylethyl)-4°-methoxydibenzoylmethane is required, and even if it is added in excess, the effects of the present invention will not be impaired. However, care must be taken because if it is incorporated in a significantly excessive amount, the quality as an external skin preparation may be impaired.

In the present invention, 4-(1,1-dimethylethyl)-4
As the skin external preparation base in which °-methoxydibenzoylmethane and oil having an iodine value of 70 or more are blended, any usual skin external preparation base can be used.

In other words, it is in the form of liquid, gel, paste, cream, etc., and the ingredients that modify the external skin preparation include moisturizers, oils, surfactants, thickeners, metal sealants, other ultraviolet absorbers, and drugs. It goes without saying that , pigments, fragrances, etc. can be used in combination.

[Example 1] Sunscreen oil 4-(1,1-dimethylethyl) 2wt%-
4°-Methoxydibenzoyl methane glyceryl monooleate 2 Linseed oil
20 liquid paraffin
76 (blank below) [Effects of the invention] Example 1 is a skin external preparation containing 4-(1,1-dimethylethyl)-4°-methoxydibenzoylmethane and an oil with an iodine value of 70 or more according to the present invention. It is.

On the other hand, the case where 4-(1,1-dimethylethyl)-4'-methoxydibenzoylmethane is not blended and the case where ester is not blended are shown below as control examples.

Control example 1> 4-(1,,1-dimethylethyl) 2wt
%-4°-Methoxydibenzoylmethane glyceryl monooleate 2 Liquid paraffin 96 <Control example 2> Glyceryl monoole) 2 wt% Linseed oil 20 Liquid paraffin 78 Table 1 shows the storage stability and UV protection effect.

The skin external preparations of Example 1 and Control Examples 1.2 are both used as sunscreen oils.

Although Control Example 1 was in a uniform liquid state immediately after production, 4-(
1,1-dimethylethyl)-4[deg.]-methoxydibenzoylmethane gradually precipitates, deteriorating its quality as an external skin preparation and even reducing its ultraviolet protection effect.

In Control Example 2, no crystals were precipitated, but of course no UV protection effect could be expected.

On the other hand, in Example 1, no crystals are precipitated not only immediately after production but also after long-term storage, and the product has excellent ultraviolet protection effects and stable quality.

This is a result of applying the technology according to the present invention.

(Left below) Table 1. Evaluation of crystal precipitation of products stored at room temperature O: No precipitation X: Precipitation present Next, the present invention will be described in detail with more examples, but the present invention is not limited thereto.

(Left below) Example 2 A, Cetanol 3 wt% glyceryl monostearate 2 POE (25) Cetyl ether 1 Stearic acid 3 Vaseline 3 Olive oil 3 Cottonseed oil 1 Squalane 54-(1,1-
dimethylethyl) 2-4゛-methoxydibenzoylmethane fragrance appropriate amount B. Propylene glycol Potassium trihydroxide 0.2 Purified water The oil phase portion of amount A and the water phase portion of B are respectively heated and dissolved at 70°C, and added to At-B and emulsified. After that, it is cooled to obtain cream.

Example 3 4-(1,1-dimethylethyl) 5wt%-4゛-
Methoxydibenzoylmethane solid paraffin 20 Vaseline 2° Castor oil 4° Persimmon oil 5 Evening primrose oil 3 Mixed coloring agent (red) 7 Fragrance, appropriate amount Dissolve each of the above ingredients by heating at 80°C, then pour into the designated container. Get the lipstick.

(Left below) Example 4 A. Stearyl alcohol 2wt% glyceryl monostearate 2 Stearic acid 2 Refined lanolin 2 Safflower oil
2 Herring oil 2 4-(1,1-dimethylethyl) 2 -4'-methoxydibenzoylmethane preservative Appropriate amount fragrance
Appropriate amount B, glycerin
5 Potassium hydroxide 0.2 Purified water Quantity C, gi 1 Combined powder 10A oil phase raw material and B water phase raw material are respectively heated and dissolved at 70°C, and then A is added to B and emulsified. A creamy foundation is obtained by dispersing the powder part of C and cooling the mixture.

Example 5 Olive oil 50wt% rapeseed oil
15 Camellia oil 15 Liquid paraffin 1°4-(1,1-dimethylethyl)10-4°-methoxydibenzoylmethane dye Appropriate amount Fragrance Appropriate amount Dissolve each of the above ingredients by heating at 50°C, then stir and cool to form a body oil. obtain.

(Left below) Example 6 Solid paraffin 10wt% liquid paraffin Amount to make the whole 100 Vaseline
20 Glyceryl monomyristate 10 h Primrose oil 0,054- (1,
(1-dimethylethyl) 0.1-41-methoxydibenzoylmethane dye (appropriate amount) Perfume (appropriate amount) Each of the above components is heated and dissolved at 50°C, and then cooled with stirring to obtain a body gel.

The external skin preparations of Examples 2 to 6 had excellent ultraviolet absorption effects, and there was no deterioration in quality due to crystal precipitation even 3 months after production.

This is a result of applying the technology according to the present invention.

Claims (1)

[Claims] An external preparation for skin, characterized in that it contains 4-(1,1-dimethylethyl)-4'-methoxydibenzoylmethane and an oil having an iodine value of 70 or more.