JPH07309742A - Creamy skin cleanser - Google Patents

Abstract

PURPOSE:To obtain a creamy skin detergent, containing a higher fatty acid salt, an anion and/or an amphoteric surfactants under specific conditions, good in high-temperature stability or foaming, gentle to the skin and excellent in refreshing feeling after cleaning. CONSTITUTION:This creamy skin detergent is obtained by adding an anionic surfactant (e.g. an N-acyl-N-methyl-beta-alanine salt) and/or an amphoteric surfactant (e.g. an alkyldimethylbetaine) to a salt of a higher fatty acid with <=1wt.% content of a <=12C fatty acid as a base. When the detergent comprises the higher fatty acid salt and anionic surfactant, the blended amounts thereof are 0.1-20wt.% anionic surfactant and 0.4-80wt.% salt of the higher fatty acid. When the detergent comprises the salt of the higher fatty acid and amphoteric surfactant, the blended amounts thereof are 0.1-20wt.% amphoteric surfactant and 0.4-80wt.% salt of the higher fatty acid. When the detergent comprises three of the salt of the higher fatty acid, anionic and amphoteric surfactants, the total amount of the added surfactants is 0.1-20wt.% based on the weight of the detergent. The resultant detergent is useful as a low-cost detergent for washing faces or bodies.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cleansing agent for face washing or body which is low in cost and gentle on the skin.

[0002]

2. Description of the Related Art Cleaning agents such as body shampoo and facial cleanser that come into direct contact with the skin are required to have good foaming properties and be gentle to the skin. Therefore, many skin cleansing agents mainly containing various anionic surfactants such as N-acyl-L-glutamic acid salt, sulfosuccinic acid monoester salt, acylmethyl taurine salt, and acyl sarcosine salt have been published as patents (special features JP-A-61-272295, JP-A-62
-4796, JP-A-62-109897,
JP-A-62-297398, JP-A-1-2870
17 and JP-A-3-153798). However, since these anionic surfactants are expensive, it is difficult to compete with conventional soap as a skin cleanser. Also, when body shampoos and facial cleansers are prepared using conventional creamy soaps, the strong degreasing power of soaps excessively removes sebum and weakens the skin's moisturizing function, resulting in a feeling of tightness after washing. It may cause. Furthermore, conventional creamy skin cleansing agents based on soap have the drawback that the components are separated at 40 ° C or higher.

[0003]

DISCLOSURE OF THE INVENTION The present invention solves the above-mentioned problems found in the prior art, has good stability at high temperature, good foaming, is gentle on the skin, and has a refreshing feeling after washing. Therefore, it is an object of the present invention to provide a creamy skin cleansing agent that can be competitive against conventional products in terms of price.

[0004]

The present inventors have completed the present invention as a result of intensive studies to solve the above problems. That is, according to the present invention, a salt of a higher fatty acid having 12 or less carbon atoms and a fatty acid content of 1% by weight or less is used as a base, and an anionic surfactant and / or an amphoteric surfactant is added thereto. A creamy skin cleansing agent is provided.

The higher fatty acid salt for use as a skin cleansing agent base used in the present invention is a salt of a higher fatty acid having a C 12 or less fatty acid content of 1% by weight or less. As the higher fatty acid, a linear saturated fatty acid having 14 to 22 carbon atoms is preferable, and the fatty acid may be a single product or a mixture, but those having 14 and 16 carbon atoms are particularly preferable in terms of both economical efficiency and cleaning effect. In addition to sodium ions and potassium ions, basic amino acid ions and the like can be used as counter ions constituting the salt, but sodium ions and potassium ions are preferable from the viewpoint of both economical efficiency and cleaning effect. The higher fatty acid salt used here may contain a small amount of free fatty acid or free base. In the skin cleansing agent of the present invention, the higher fatty acid salt is generally contained in an amount of 5 to 50% by weight, preferably 10 to 40%.
Wt% is added. When the amount added is less than 5% by weight, sufficient detergency cannot be obtained, and when the amount added exceeds 50% by weight, the composition becomes too hard and it becomes difficult to make the product into a cream.

The anionic surfactant added to the skin cleansing agent of the present invention has been conventionally used as a skin-friendly cleansing agent, but when used in combination with a higher fatty acid salt, it exhibits a synergistic effect in cleansing action. At the same time, a skin cleansing agent is obtained which has high temperature stability, good foaming, is gentle on the skin, and has a refreshing feeling after washing. The anionic surfactant used here is one or a mixture of two or more selected from N-acyl-N-methyl-β-alanine salt, ether carboxylate, acyl sarcosine salt, sulfosuccinate salt and the like. However, an anionic surfactant selected from the above four is preferable. The hydrocarbon group constituting the acyl group or ether group in the surfactant is preferably a linear saturated aliphatic group having 8 to 22 carbon atoms, and sodium is used as the counter ion constituting the salt. Ions and potassium ions are preferred. And a particularly preferred anion activator is an N-acyl-N-methyl-β-alanine salt having an acyl group having 8 to 22 carbon atoms, specifically, sodium salt, potassium salt of lauroylmethyl-β-alanine, Examples include triethanolamine salt and the like.

The amphoteric surfactant added to the skin cleansing agent of the present invention, when used in combination with a higher fatty acid salt, exhibits a synergistic effect in terms of cleansing action, has good high-temperature stability and good foaming, is gentle on the skin, and has a good effect on the skin after cleaning. A skin cleanser having a refreshing feeling can be obtained. Further, when both an anionic surfactant and an amphoteric surfactant are added to the higher fatty acid salt, the above-mentioned advantages due to the addition of the surfactant are exhibited and it is also advantageous in terms of raw material cost.
The amphoteric surfactant used here is one or a mixture of two or more selected from alkyldimethylaminoacetic acid betaine, alkylamidopropyl betaine and alkyldimethylamine oxide. The alkyl group in these compounds is preferably a straight chain alkyl group having 8 to 22 carbon atoms,
Particularly, a lauryl group and a myristyl group are preferable. Particularly preferred activator among the amphoteric surfactants is a linear alkyldimethylaminoacetic acid betaine having an alkyl group having 8 to 22 carbon atoms, specifically, lauryldimethylaminoacetic acid betaine, myristyldimethylaminoacetic acid betaine, Capryl dimethylamino acetic acid betaine.

When the skin cleanser of the present invention comprises a higher fatty acid salt and an anionic surfactant, the amount of the anionic surfactant added to the cleanser is 0.1 to 20% by weight, preferably 0.1.
5 to 10% by weight, and 0.4 to 80% by weight, preferably 2 to 40% by weight, of the higher fatty acid salt. If the amount added to the detergent is less than 0.1% by weight, the effect of improving foaming due to the addition is insufficient, and if the amount added exceeds 20% by weight, creaming becomes difficult. In addition, 0.4 of higher fatty acid salt
If the addition amount is less than wt%, the foam increasing effect is not sufficient, and if the addition amount exceeds 80 wt%, creaming becomes difficult. When the skin cleanser of the present invention comprises a higher fatty acid salt and an amphoteric surfactant, the amount of the amphoteric surfactant added to the cleanser is 0.1.
-20% by weight, preferably 0.5-10% by weight,
0.4-80% by weight of higher fatty acid salt, preferably 2-4
It is 0% by weight. If the amount added to the cleaning agent is less than 0.1% by weight, the effect of improving foaming due to the addition is not sufficient,
If the amount added exceeds 20% by weight, creaming becomes difficult. Further, the addition of less than 0.4% by weight of the higher fatty acid salt is not sufficient for the foam-enhancing effect, and when the addition amount exceeds 80% by weight, creaming becomes difficult.

When the skin cleansing agent of the present invention comprises three components, a higher fatty acid salt, an anionic surfactant and an amphoteric surfactant, the sum of the addition amounts of the anionic surfactant and the amphoteric surfactant is calculated based on the weight of the cleansing agent. 0.1 to 20% by weight, preferably 0.5 to
It may be 10% by weight. And, when the sum of the amounts of both active agents added to the detergent is too small or too large, the effect does not change from the above, and since the washing ability and the like do not change with the addition ratio of the anionic surfactant and the amphoteric surfactant, both active agents are not changed. It can be seen that the agent exhibits additivity when added to the higher fatty acid salt. In addition to the above components, various additives known as additives for creamy skin cleansing agents can be added to the creamy skin cleansing agent of the present invention. For example, in order to stabilize the product, a nonionic surfactant or a pH adjusting agent may be added, and a moisturizing agent, a dye, a chelating agent, a fragrance, etc. may be added. Further, propylene glycol, dipropylene glycol, hexylene glycol, polyethylene glycol, 1,3-butylene glycol, sorbitol and the like can be added as a solvent.

[0010]

The present invention will now be described in more detail by way of examples, which should not be construed as limiting the invention.

Examples 1 to 6 and Comparative Examples 1 to 4 Creamy skin cleansing agents having the composition shown in% by weight in Table 1 were prepared by a conventional method, and sensory evaluation of various performances thereof was tried by the following methods. The results are shown in Table 2. (Amount of foam, fineness of foam, rinsability) The results of sensory evaluation by panelists of 5 males and 5 females, 10 in total are shown in Table 2 on average. The evaluation method is as follows:
A hand wash test was performed with warm water at 0 ° C, and each panelist performed a sensory evaluation on the amount of foam, the fineness of the foam, and the rinsability. ◎ was very good, ○ was good, △ was bad, and very bad. It is shown by x. (Tightening feeling) The sensory evaluation results by 10 female panelists are shown in Table 2 on average. As an evaluation method, about 1 g of a sample was taken on a palm and a face wash test was performed with hot water at 35 to 40 ° C., and a feeling of tightness after about 5 minutes of towel drying was sensory-evaluated. The case where there is is indicated by ◯, the case where there is a feeling of tightness is indicated by Δ, and the case where there is a considerably strong feeling of tension is indicated by ×.

(Surface Roughness) Table 2 shows the average of the results of sensory evaluation by 10 panelists, 5 male and 5 female. The evaluation method was as follows: the left or right forearm of the panel was soaked for 10 minutes in the aqueous skin cleanser solution of Example and Comparative Example at a concentration of 1% by weight and the other forearm was immersed in water of the same temperature for 10 minutes. The immersion test was performed once a day for 2 consecutive days, and the difference in the rough skin condition of the left and right forearm skin was visually determined. And, when skin roughness on the skin cleanser side of 0 to 10 out of 10 people is considered to be extremely rough, ◎ when skin roughness on the skin cleanser side of 2 to 4 out of 10 skin is recognized As the skin roughness is slightly weak,
When skin roughness on the skin side of 5 to 7 out of 10 people is observed, it is considered that the skin roughness is rather strong. △ out of 10 8
When rough skin was observed on the skin on the side of the skin cleansing agent of 10 persons, the rough skin property was markedly marked by x.

(Protein denaturation) A sample solution was prepared by adding a skin cleansing agent to a buffer solution (stock solution) containing 0.5% by weight of ovalbumin at pH 7 so that the concentration in the buffer solution would be 1% by weight. Was prepared and the ovalbumin (protein) denaturation rate of the sample solution after standing at 40 ° C. for 24 hours was determined. A denaturation rate of less than 30% ⊚, a denaturation rate of 30 to 50% ◯, and a denaturation rate of more than 50%. 8
Less than 0% is indicated by Δ, and modification rate of 80% or more is indicated by x. The protein denaturation rate is calculated from the result of analyzing the sample solution by high performance liquid chromatography, and the height of the absorption peak at 220 nm (absorption peak of ovalbumin) obtained by high performance liquid chromatography of the stock solution is A, and the sample is Letting B of the solution, the protein denaturation rate can be calculated from the following equation. Protein denaturation rate (%) = 100 (A−B) / A The stock solution was prepared by diluting 3.04 g of monosodium phosphate and 10.9 g of disodium phosphate to 1 liter with pure water. (High temperature stability) Fill the sample into a 50 ml vial bottle,
After storing at 42 ° C for 1 month, visually inspect the separation state of the sample, ○ when the separation is not observed, △ when the lower part of the bottle is slightly separated, and the lower part of the bottle is completely separated The case of doing is shown by x.

[0014]

[Table 1] * One of the hydroxyl groups of glycerin is pyroglutamic acid ester, the other is isostearic acid ester, and the remaining hydroxyl group is polyethylene glycol ether with a degree of polymerization of 25. Nonionic surfactant (trade name:
Emarex GPI-25) was used.

[0015]

[Table 2]

From Table 2, the skin cleansing agents of the examples show satisfactory results in all of the evaluation items, but those of the comparative examples are obviously carried out in terms of tightness, rough skin, protein denaturation and high temperature stability. The skin cleanser of the comparative example cannot be said to be a satisfactory skin cleanser because it is inferior to the cleansing agents of the examples. Further, as can be seen from Comparative Example 3, the above-mentioned evaluation result is higher in the skin cleanser having a low lauric acid content, but in the skin cleanser containing no surfactant, lauric acid is not contained. The evaluation result is poor (Comparative Example 4), and it is understood that the ideal skin cleanser does not contain lauric acid but contains a surfactant.

[0017]

EFFECTS OF THE INVENTION The creamy skin cleansing agent of the present invention has better stability at high temperature and better foaming than the conventional cleansing agent containing a fatty acid soap as a main ingredient, and also has a low skin roughness and a low protein denaturation rate. Since it is gentle on the skin and has less tightness after washing, it is far superior to conventional detergents containing a fatty acid soap as a main detergent for face washing and body washing. In addition, since the detergent of the present invention is mainly composed of fatty acid soap, it is considerably lower in price than conventional detergents containing anionic surfactant as a main ingredient, and is lower in price than conventional products and has a performance equal to or higher than that of conventional products. It is a cleaning agent that can be provided.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Mototaka Kinoshita 1-3-7 Honjo, Sumida-ku, Tokyo Inside Lion Corporation

Claims (3)

[Claims] 1. A base of a salt of a higher fatty acid having a fatty acid content of 12 or less carbon atoms and a content of 1% by weight or less, to which an anionic surfactant and / or an amphoteric surfactant is added. A creamy skin cleanser. 2. The anionic surfactant is N-acyl-N.
-Methyl-β-alanine salt, ether carboxylic acid salt, acyl sarcosine salt and sulfosuccinic acid ester salt, which is one kind selected from the group consisting of, or a mixture of two or more kinds. The creamy skin cleanser described. 3. The amphoteric surfactant is one kind selected from the group consisting of alkyldimethylaminoacetic acid betaine, alkylamidopropyl betaine and alkyldimethylamine oxide, or a mixture of two or more kinds. The creamy skin cleansing agent according to claim 1.