JPH11349428A - Cosmetic - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a cosmetic exhibiting excellent foamability under weakly acidic conditions, not having a problem on the point of skin irritation and useful as a base agent, a cleansing agent, an emulsifier or a conditioning agent for hair or skin cosmetics by compounding a specific anion surfactant. SOLUTION: This cosmetic contains an anion surfactant of formula I [(n) is 0 or 1; X is COOH or H; Y is CH2 COOH, CH2 CH2 COOH or the like; R is a 8-20C fatty acid residue] preferably in an amount of 1-50 wt.% based on the total amount of the cosmetic. The anionic surfactant is obtained by acylating a raw material of formula II. When the washability of the anion surfactant is targeted, the long chain fatty acid is preferably a 12C fatty acid, a 14C fatty acid or their mixture. The counter ion includes hydrogen ion, monovalent alkali metal ions and divalent alkaline earth metals. Preferably, the anionic surfactant is used as a partially neutralized salt corresponding to the physiological pH of skin. Examples of the cosmetic include skin milks and skin creams.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a cosmetic containing an anionic surfactant useful as a base, a cleansing agent, an emulsifier, and a conditioning agent for hair and skin cosmetics.

[0002]

2. Description of the Related Art Various anionic surfactants useful as detergents, emulsifiers and conditioning agents have hitherto been known. However, the fact is that there is no cosmetic which shows excellent foaming properties under a weak acidic condition at the physiological pH of the skin and has no problem in terms of skin irritation, and improvement thereof has been desired.

[0003]

The problem to be solved by the present invention is that when it is formulated into a cosmetic, it exhibits excellent foaming properties under a weak acidity, which is a physiological pH of the skin, and has a problem in terms of skin irritation. The aim is to develop good cosmetics without problems.

[0004]

The present inventors have conducted intensive studies in view of the above circumstances, and as a result, the following specific cosmetics show excellent foaming properties under weakly acidic conditions and have no problem in terms of skin irritation. Thus, the present invention has been completed.

That is, claim 1 of the present invention is a general formula

[0006]

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A cosmetic comprising an anionic surfactant represented by the formula:

[0008]

Next, the configuration of the present invention will be described. The anionic surfactant according to the present invention can be easily obtained using the raw material of Chemical Formula 3.

[0009]

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The compounds represented by the general formula are all known (JP-A-8-31003), and the acylation reaction is carried out using the compounds to easily obtain the anionic surfactant according to the present invention. Can be For the purpose of cleaning,
The number of carbon atoms of the long-chain fatty acid is preferably 12, 14 or a mixture thereof, and a linear or branched one is selected depending on the use. Counter ion is hydrogen ion, monovalent or 2
One or more kinds of alkali metal ions, alkaline earth metal ions, ammonium ions or organic ammonium ions are suitably selected from the valences, and it is desirable to use them as partially neutralized substances corresponding to skin physiological pH.

The content of the anionic surfactant in the present study was as follows:
It is preferably from 0.01 to 70% by weight, particularly preferably from 1 to 50% by weight, based on the total amount of the cosmetic (composition).

The cosmetics of the present invention mean cosmetics for the skin and hair (including those for cleaning) in general. For example, skin milk, skin cream, foundation cream,
Basic creams such as massage creams, cleansing ingredients (make-up removers), face-wash creams, lotions, scalp treatments, hair creams, hair shampoos, and hair rinses, makeup cosmetics, and hair cosmetics.

[0013]

The present invention will be described below with reference to examples. The test methods described in the examples are shown below.

Twenty female panelists were continuously used for 30 days every day to evaluate foaming properties and skin irritation. The foaming property was evaluated as "Excellent", "Good" as "Good", "Slightly good" as "Poor", and "Poor" as Poor. The results are shown as average values. The skin irritation was evaluated as ◎, almost non-existent as Δ, slightly as Δ, fairly as X, and evaluated as 5, 4, 3, 2, 1 respectively. The results are shown as average values.

Examples 1 to 6, Comparative Example 1 [Facial cleanser] Using various emulsifier components as shown in Tables 1 and 2 and various raw materials as shown in Table 3, the following preparation methods were used. A face wash of a comparative example was prepared, and skin irritation and foaming power were evaluated.

[0016]

[Table 1]

[0017]

[Table 2]

(1) Composition

[0019]

[Table 3]

(2) Preparation Method Each component is uniformly dissolved at a temperature of 80 ° C. while stirring, and further cooled to a temperature of 30 ° C. while stirring to prepare.
The pH after preparation was 6. (3) Characteristics Table 1 shows the results of testing the characteristics of each of the examples and comparative examples. From these results, it can be seen that the face wash of the present invention is superior in skin irritation and foaming power as compared with those of the comparative example.

[0021]

As described above, it is apparent that the present invention provides a cosmetic having low skin irritation and excellent foaming power.

Claims (1)

[Claims] 1. A compound of the general formula A cosmetic comprising an anionic surfactant represented by the formula: