JPH0229044B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a novel oily whitening cosmetic in which ascorbic acid fatty acid ester is dissolved, which is transparent, has excellent stability, and provides a good whitening effect and feel when used. Ascorbic acid fatty acid ester has a melanin-reducing effect and is incorporated into whitening cosmetics. However, ascorbic acid fatty acid esters are hydrolyzed in systems containing ethyl alcohol, water, and basic substances (creams, milky lotions, lotions, etc.).
It easily undergoes reactions such as transesterification and loses its whitening effect due to denaturation, coloring, etc. Conventionally, in order to improve these drawbacks, many stabilizers such as 1-hydroxyethane-1,1-diphosphonic acid or its salts have been developed.
The current situation is that it is still insufficient and unsatisfactory. In order to stably dissolve ascorbic acid fatty acid esters in cosmetics, it is possible to use oil-based bases, solubilizers, solvents, etc. that do not contain water or alcohol, but the esters are poorly soluble in liquid oil-based substances. However, if it is left to cool after heating and melting, it tends to become cloudy and precipitate, and at present there are no suitable solubilizers or solvents. In view of the current situation, the present inventors conducted intensive research and found that ascorbic acid fatty acid ester dissolved in an esterification product of polyether polyol (added with alkylene oxide to polyol) and higher fatty acid is uniform and transparent. It is in liquid form, has excellent stability, and exhibits a good whitening effect when used.
The present invention has been completed based on the discovery that a new oily whitening cosmetic can be obtained that can provide a pleasant feel and water repellency. An object of the present invention is to provide a novel oily whitening cosmetic that is substantially transparent and liquid, has excellent stability, and can provide a good whitening effect, feel, and water repellency during use. That is, the present invention provides an oily whitening cosmetic characterized in that an ascorbic acid fatty acid ester is transparently dissolved together with 50% or more of an esterification product of a polyether polyol obtained by adding an alkylene oxide to a polyol and a higher fatty acid. It is. The details of the present invention will be explained below. The polyether polyol used in the present invention refers to a polyol such as ethylene glycol, propylene glycol, glycerin, diglycerin, trimethylolpropane, pentaerythritol, dipentaerythritol, sorbitol, sucrose, or a mixture thereof. ,
It is a polyether polyol to which one or a mixture of alkylene oxides such as ethylene oxide and propylene oxide is added. One example is polyethylene glycol having an average molecular weight of 200 to 600. The amount of alkylene oxide added is preferably 3 to 30 moles per mole of polyol. As the higher fatty acid to be esterified with the polyether polyol obtained by adding alkylene oxide to a polyol, a fatty acid having 8 or more carbon atoms is used. If it is less than 8, it is not preferred from the viewpoint of skin irritation. Examples of such fatty acids include the following: That is, as higher linear saturated fatty acids, caprylic acid, pelargonic acid, and capric acid can be used. When the number of carbon atoms is 12 or more, it is not preferable because it becomes paste-like or solid-like. Palmitooleic acid, oleic acid, linoleic acid, erucic acid, etc. can be used as higher linear unsaturated fatty acids. Higher side chain fatty acids include isooctylic acid, isononanoic acid, isomyristic acid,
Synthetic fatty acids such as isopalmitic acid and isostearic acid can be used. Among these, higher side chain saturated fatty acids are particularly preferred in terms of oxidation stability, feel, freezing point, etc. Note that higher fatty acids can be used alone or in combination of two or more. The esterification reaction between a polyether polyol obtained by adding alkylene oxide to a polyol and a higher fatty acid is carried out without a catalyst or in the presence of a catalyst (for example, tin chloride) at room temperature or under reduced pressure according to a conventional method. The end point of the reaction is determined by the acid value. After the esterification reaction is completed, the product is decolorized using a decolorizing agent according to a conventional method, and then deodorized and purified using steam. The amount of ascorbic acid fatty acid ester dissolved in the esterification product of polyether polyol and fatty acid, which is obtained by adding alkylene oxide to polyol, is 0.1 to 5% (by weight; the same applies hereinafter) of the cosmetic, preferably 1 to 3%. Within range. 0.1%
If it is less than 5%, the effect of ascorbic acid fatty acid ester is small and therefore the whitening effect cannot be expected much.If it is more than 5%, it will dissolve in the esterification product of polyether polyol and fatty acid, which is obtained by adding alkylene oxide to polyol. There is a possibility that crystals may be precipitated without finishing, which may be unfavorable in terms of appearance. In addition to the above-mentioned ingredients, the cosmetic of the present invention also includes liquid oil bases such as olive oil, safflower oil, sesame oil, avocado oil, jojoba oil, squalane, lanolin, and other animal and vegetable oils, isopropyl myristate, isopropyl palmitate, and octyl. Synthetic oil agents such as dodecyl myristate, diisopropyl adipate, diisopropyl sebacate, 2-ethylhexanoic acid triglyceride, isostearic acid triglyceride, higher alcohols such as oleyl alcohol, isostearyl alcohol, octyl dodecanol, or a combination thereof may be blended. is also possible. However, since the above-mentioned animal and vegetable oils, synthetic oils, and higher alcohols have almost no solubility in ascorbic acid fatty acid esters, the amount used thereof is preferably 50% or less of the cosmetic composition. Furthermore, when using the above-mentioned animals and plants, synthetic oils, and higher alcohols, it is necessary to reduce the amount of ascorbic acid fatty acid ester added, which is 0.1
~3% is appropriate. Ascorbic acid fatty acid esters used in the present invention are monoesters, diesters, triesters, etc. obtained from ascorbic acid and higher fatty acids, and examples of fatty acids include lauric acid, myristic acid, palmitic acid, stearic acid, arachidic acid, and behenin. acids, oleic acid, linoleic acid, etc. Among them, ascorbic acid monostearate, ascorbic acid monopalmitate, ascorbic acid distearate, ascorbic acid dipalmitate, etc. are preferred from the viewpoint of easy availability. It is also possible to use a combination of two or more of the above ascorbic acid fatty acid esters. Commonly added ingredients used in the cosmetics of the present invention include fragrances and colorants, and if necessary, vitamins such as vitamins A, D, and E,
A known ultraviolet absorber such as urocanic acid may be added. The oily whitening cosmetic of the present invention usually contains each component.
It is prepared by stirring and dissolving the mixture at 40 to 130°C, and then allowing it to cool. The obtained oily whitening cosmetic of the present invention is substantially transparent and exhibits a fluid oily state, and the ascorbic acid fatty acid ester is an esterification product of a polyether polyol obtained by adding an alkylene oxide to a polyol and a fatty acid. It has been solubilized by the chemical and is protected from oxygen, moisture, etc.
Even when stored for a long period of time, it does not become cloudy, gel, or reduce its whitening effect, and is extremely stable. Furthermore, when used, it acts and penetrates into the skin quickly, producing a good whitening effect and vitamin C action. At the same time,
Its effects are extremely unique, giving it a good feeling, and its oily film imparts water resistance and water repellency, allowing it to retain its cosmetic effect, and has an extremely high commercial value. The present invention will be explained below using specific examples. Example 1 Storage stability test Ascorbic acid esters were as shown in Table 1.
A predetermined amount is added to an esterified product of a polyether polyol obtained by adding alkylene oxide to a polyol and a fatty acid, and the mixture is mixed and stirred under a nitrogen stream or in the presence of air while heating to 70 to 100°C to dissolve. After dissolving, cool slowly, then put 40ml into a 50ml transparent sample bottle, store in a 40℃ thermostat and at room temperature,
Appearance, residual amount of ascorbic acid fatty acid ester,
We investigated the feel during use. The results are also shown in the same table. The amount of ascorbic acid fatty acid ester was determined by dissolving the sample in ethanol, adding α,α'-dipyridyl and ferric chloride solution, and then measuring the absorption at 540 nm.

[Table] Instead of the esterified products in Table 1, olive oil, 2-ethylhexanoic acid triglyceride, isopropyl myristate, castor oil, jojoba oil, squalane, isostearyl alcohol were used,
Ascorbic acid monostearate was dissolved at 80 to 100°C, but the dissolved amount was less than 0.1% in each case, so it cannot be expected to be used as a liquid whitening cosmetic, and when stored for a long time, ascorbic acid monostearate dissolved in trace amounts. started to break down. In addition, as a result of testing the liquid whitening cosmetic of the present invention on a panel of five healthy women, there was virtually no difference between the sample immediately after manufacture and the sample after storage for 6 months, and both showed good whitening effects. We confirmed that it works. Ascorbic acid fatty acid ester is naturally easily decomposed by oxygen, moisture, etc., but as can be seen from the results in Table 1, ascorbic acid is almost the same when dissolved under a nitrogen stream and when dissolved under oxygen storage. This shows that the esterification product of polyether polyol, which is obtained by adding alkylene oxide to polyol, and higher fatty acid is optimal as a dissolving agent for ascorbic acid fatty acid ester. Example 2 Next, a specific formulation example will be shown. Formulation example 1 Polyethylene glycol (average molecular weight 600) diisooctylate 95.9% Ascorbic acid monostearate 4.0% Tocopherol 0.1% Preservatives, fragrances, pigments Appropriate amounts Formulation example 2 Polyethylene glycol (average molecular weight 400) diisostearate 70.0% (isostearin) Acid: Manufactured by Emery) Squalane 26.0% Ascorbyl dipalmitate 3.9% Tocopherol 0.1% Preservatives, fragrances, pigments Appropriate amount combination example 3 Polypropylene (average molecular weight 600) diisooctylate 60.0% Ethanol 35.0% Ascorbic acid distearate 5.0% Antioxidant , preservatives, fragrances, pigments Appropriate amounts blending example 4 Glycerin ethylene oxide adduct (average molecular weight 500) isooctylic acid monoester 50.0% Olive oil 47.0% Ascorbic acid monopalmitate 3.0% Antioxidants, preservatives, fragrances, pigments Appropriate amounts.

Claims (1)

[Scope of Claims] 1 Contains 50% or more of an esterification product of a polyether polyol obtained by adding alkylene oxide to a polyol and a higher fatty acid having 8 or more carbon atoms,
An oily whitening cosmetic characterized by transparently dissolved ascorbic acid fatty acid ester. 2. The oily whitening cosmetic according to claim 1, wherein the alkylene oxide is ethylene oxide and/or propylene oxide. 3. The oily whitening cosmetic according to claim 1, wherein the polyether polyol is polyethylene glycol (average molecular weight 200 to 600). 4. The oily whitening cosmetic according to claim 1, wherein the higher fatty acid is isooctylic acid. 5 Ascorbic acid fatty acid ester content is 0.1
The oily whitening cosmetic according to claim 1, wherein the content is 5% by weight. 6 Animal and vegetable oils and fats such as olive oil, safflower oil, sesame oil, avocado oil, jojoba oil, squalane, and lanolin, isopropyl myristate, isopropyl palmitate, octyldodecyl myristate, diisopropyl adipate, diisopropyl sebacate, 2-ethylhexanoic acid triglyceride, The oily whitening cosmetic according to claim 1, which contains a synthetic oil such as triglyceride isostearate, a higher alcohol such as oleyl alcohol, isostearyl alcohol, octyldodecanol, or a combination thereof. 7. The oily whitening cosmetic according to claim 1, wherein the ascorbic acid fatty acid ester is one of ascorbic acid monostearate, ascorbic acid monopalmitate, ascorbic acid dipalmitate, ascorbic acid distearate, or a mixture thereof.