JPS5892604A - Preparation of water-in-oil-type emulsion cosmetic - Google Patents

Abstract

PURPOSE:To prepare the titled emulsion cosmetic having high gel stability, preservable for a long period, and giving refreshing feeling to the skin, by adding an aqueous solution of a water-soluble polymer to liquid lipophilic surface active agent at normal temperature, and dispersing the resultant gel in an oily component. CONSTITUTION:An aqueous solution of a water-soluble polymer is added to a lipophilic surface active agent which is liquid at normal temperature, e.g. glycerin monooleate, under stirring to obtain a gel. The gel is dispersed in an oily component, and if necessary added with water to obtain the objective emulsion cosmetic. The water-soluble polymer is e.g. sodium arginate, sodium pectinate, sodium carboxy-methylcellulose, carboxyvinyl polymer, etc. or their mixture. The amount of the lipophilic surface active agent is 0.5-8wt% of the whole composition, and the amount of the water-soluble polymer is 1-10 times weight of the lipophilic surface active agent in terms of 0.1-5% aqueous solution.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a novel water-in-oil type (hereinafter referred to as W2O type) emulsified cosmetic, and more specifically, an emulsification method conventionally known as the so-called "gel emulsification method". It is about improvement.

The following three methods have been known as the "gel emulsification method" as a method for producing W10 type emulsified cosmetics. That is, (1) a gel consisting of a lipophilic surfactant and a polyhydric alcohol (or an aqueous solution thereof) is prepared.

■ Prepare a gel consisting of a lipophilic surfactant and an aqueous amino acid solution (or an aqueous amino acid salt solution).

(2) Prepare a gel consisting of a lipophilic surfactant and an aqueous organic acid solution (or an aqueous organic acid salt solution).

The gist of the method was to add the gel obtained by such a method to an oily component and disperse it, and then, depending on the case, further add water.

However, in each of the above-mentioned conventional methods, if some additive is added to the aqueous phase, the general gel becomes unstable, and the stability of the final emulsified cosmetic is also reduced. Sometimes.

However, there are many restrictions in obtaining a stable gel, the process may be complicated, and the flexibility in formulation may not be effective.

In reality, it was not always easy to apply it to actual products because of the disadvantages such as these.

Therefore, the inventors of the present invention have carefully considered the above-mentioned drawbacks, and as a result of continuing intensive research, the present inventors have found that they can solve these problems by using a gel consisting of an aqueous solution of a water-soluble polymer and a lipophilic surfactant that is liquid at room temperature. The present invention has been completed by successfully solving the above drawbacks. That is, in the present invention, a gel is prepared by adding an aqueous solution of a water-soluble polymer to a lipophilic surfactant that is in a liquid state at room temperature under stirring, and after adding the gel to an oil component and dispersing it, This is a method for producing a W10 type emulsified cosmetic, which is characterized by adding water as necessary.

As the water-soluble polymer used in the present invention, sodium alginate, pectin, sodium pectate, sodium carboxymethylcellulose, carboxyvinyl polymer, etc. can be used, and these may be used alone or in combination. Similarly, as the lipophilic surfactant used in the present invention, those commonly used in the field of cosmetics can be used, such as glycerin monooleate, glycerin dioleate, diglycerin monooleate,
These include diglycerin diolate, glycerin monoisostearate, glycerin diisostearate, diglycerin monoisostearate, diglycerin diinstearate, etc., and these can be used alone or in combination.

By the way, in the present invention, the amount of lipophilic surfactant used to prepare the gel is 0 to 0 for the entire formulation.
The amount is 5 to 8% by weight, more preferably 1 to 5% by weight. 0
If it is less than 5% by weight, the emulsion will lack stability, and if it is more than 8% by weight, it will not be pleasant to the touch. Similarly, the amount of water-soluble polymer used in the present invention is 0.1
1 to 10 of the weight of lipophilic surfactant as a ~5 water amendment solution
It is better to use double the amount. In a water-soluble polymer aqueous solution with a concentration of 0.1% or less, the prepared gel 8 becomes unstable and 5
% or more, the viscosity of the aqueous solution itself (too high) or preparation of such a highly concentrated aqueous solution is difficult depending on the type of water-soluble polymer, making it unsuitable.In addition, the weight of the lipophilic surfactant When the amount of water-soluble polymer aqueous solution is less than 1 times the amount of gel (it is difficult to form a gel, and even if it is formed, it is unstable, and it is more than 10 times the amount of water that can be retained in the gel structure). The amount is close to the limit and the gel may be destroyed, so it is still unsuitable.Furthermore, the effects obtained by the present invention include a) high water retention capacity of the water-soluble polymer, and stability of the prepared gel; It is strong and good, and the gel can be stored for a long time.

b. The W10 type emulsified cosmetic obtained from OC0, which can be formulated with humectants such as propylene glycol and butylene glycol, which were conventionally used to destabilize the gel, has a soft feel when used. Moreover, it has excellent moisturizing effects that keep the skin moist.

d. Syneresis of the internal aqueous phase, which is a drawback of conventional W10 type emulsified cosmetics, is less likely to occur.

The following points can be mentioned.

Hereinafter, the present invention will be described in detail based on Examples.

Example (lime) Composition Weight %B
Diglycerin diisostearate
3E [Fragrance
02 Preparation method C is added to B with stirring to prepare a gel. Add the gel to A dissolved at 70''C and disperse it, then add D and emulsify it. After that, add E and cool it to make a product.

Comparative Example I (by conventional emulsification method) Of the compositions of Examples, A and B were mixed and dissolved at 70°C. Add a mixture of C and D and emulsify. Thereafter, after adding E, the mixture is cooled to obtain a product.

Comparative Example U (by conventional gel emulsification method) A product is obtained in the same manner as in the example except that C in the composition of the example is replaced with 5 ml of a 65% sorbitol aqueous solution.

Table I shows the results of comparative evaluation of the three types of W2O molds 1)-me obtained as described above in terms of particle size, high stability, and feel. The cream is superior in all aspects and has the power to do so.

Claims (1)

[Claims] +11 A gel is prepared by adding an aqueous solution of a water-soluble polymer to a lipophilic surfactant that is liquid at room temperature under stirring,
A method for producing a water-in-oil emulsified cosmetic, which comprises adding water to an oil-based component after the gel is dispersed therein, if necessary. (2; Water-in-oil emulsion cosmetic according to claim 1, wherein the water-soluble polymer is one or a combination of two or more of sodium alginate, pectin, sodium pectate, sodium carboxymethylcellulose, and carboxyvinyl polymer. Method of manufacturing food.