JP2007254431A - Weakly acidic gelatinous skin cleansing agent - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a weakly acidic gelatinous cleansing agent free from temperature dependency of viscosity, giving no creaking feeling originated from silicic anhydride, and having good aging stability (resistance to liquid separation) and excellent foaming property in use, foam retention in use and smoothness of the skin after cleansing. <P>SOLUTION: The weakly acidic gelatinous skin cleansing agent is produced by compounding (a) an N-acyl-L-acidic amino acid salt, (b) 1-20 mass% silicic anhydride and (c) an acrylic acid-dimethyldiallylammonium chloride-acrylamide copolymer. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a weakly acidic gel-like skin cleanser formulated with N-acyl-L-acidic amino acid salt, silicic anhydride, acrylic acid / dimethyldiallylammonium chloride / acrylamide copolymer, and more specifically, temperature dependency of viscosity. The present invention relates to a weakly acidic gel-like skin cleanser that has good stability over time, has foaming and foam retention during use, and has excellent smoothness of the skin after washing.

Gel-like cleaning materials are preferably used because they can easily take out the required amount of use and are excellent in foaming. However, among gel-type cleaning materials, those using fatty acid soap as a cleaning component tend to have a drawback that the viscosity change due to temperature is large, and a feeling of tension and dryness after cleaning. For this reason, a skin cleanser in which the cleaning component is gelled with polyethylene glycol or silicic anhydride has been developed (see, for example, Patent Documents 1 and 2). However, the gel-like skin cleanser that has been gelled with polyethylene glycol or silicic acid has little change in viscosity due to temperature and a feeling of tension after washing, but foaming during use and moist feeling after use wash fatty acid soap. There was a tendency to be inferior compared with the agent component. Moreover, it is mentioned as a fault on time stability (water separation with time). In order to improve these drawbacks, there is a technique of combining anhydrous silicic acid with a specific N-acylamino acid-based cleaning component and a cellulose derivative (see, for example, Patent Document 3). In addition, in order to ensure stability over time, a technique using a combination of silicic anhydride, a specific water-soluble polyalkylene glycol, an amphoteric surfactant, and a cationic polymer has been studied (see, for example, Patent Document 4).
JP 2004-123696 A (page 1 to page 8) JP 2005-336068 A (pages 1 to 12) JP 2003-48823 A (pages 1 to 5) Japanese Patent Application Laid-Open No. 2002-363061 (page 1 to page 7)

However, although the gel-like cleaning material obtained by the technique of Patent Document 3 has improved foam retention, it is difficult to obtain a good feeling of use because a squeaky feeling derived from silicic acid remains after use, There was a problem that stability over time could not be sufficiently secured. Further, the gel-like cleaning material obtained by the technique of Patent Document 4 can ensure stability over time, but is not sufficiently satisfactory in foaming during use and moist feeling after use.
Accordingly, there has been a demand for the development of a gel-like skin cleanser that has little viscosity change due to temperature, good stability over time, foaming / foaming during use, and excellent skin smoothness after washing.

  In view of such circumstances, the present inventors have conducted extensive research to solve the above problems, and as a result, N-acyl-L-acidic amino acid salts, silicic anhydride, acrylic acid, dimethyldiallylammonium chloride, acrylamide copolymer. It has been found that the above-mentioned problems can be solved by combining and combining the coalescence, and the present invention has been completed based on this finding.

  That is, the present invention comprises component (a) N-acyl-L-acidic amino acid salt, (b) 1-20% by mass of silicic acid anhydride, (c) acrylic acid / dimethyldiallylammonium chloride / acrylamide copolymer 0.05- A weakly acidic gel-like skin cleanser characterized by containing 1% by mass is provided.

  The N-acyl-L-acidic amino acid salt of the component (a) provides a weakly acidic gel-like skin cleanser wherein N-lauroyl-L-aspartate is used.

  Furthermore, the weakly acidic gel-like skin cleansing agent characterized by mix | blending 0.1-5 mass% of ester oils liquid at 25 degreeC as a component (d) is provided.

The weakly acidic gel-like skin cleanser of the present invention has no temperature dependency of viscosity, has good stability over time, has foaming / foaming during use, and excellent smoothness of the skin after washing.

The configuration of the present invention will be described below.
The N-acyl-L-acidic amino acid salt of the component (a) used in the present invention is a weakly acidic cleaning component, an essential component that is mild to the skin and imparts an excellent cleaning effect. The term “weakly acidic” as used herein means that the pH of the system is preferably 5 to 6.9, and particularly preferably 5.5 to 6.5. The N-acyl-L-acidic amino acid salt of component (a) used in the present invention includes N-myristoyl aspartate triethanolamine, N-lauroylglutamate sodium, N-lauroylglutamate potassium, N-lauroylglutamate triethanolamine, N-coconut oil fatty acid acyl glutamate sodium, N-coconut oil fatty acid acyl glutamate potassium, N-coconut oil fatty acid acyl glutamate triethanolamine, N-lauroyl-L-aspartate triethanolamine, N-lauroyl-L-aspartate sodium Etc. One or two or more of these can be appropriately selected and used as necessary. Among these, N-acyl acid aspartate is preferable in order to obtain a good cleaning effect, stability over time, foaming, and the like. Specifically, N-lauroyl-L-aspartate triethanolamine is preferable. N-lauroyl-L-sodium aspartate and the like.

The component (a) used in the present invention may not only be blended as a neutralized salt, but may also react with a base in the composition to form a salt. Examples of such a base include inorganic bases such as sodium hydroxide and potassium hydroxide, and organic bases such as triethanolamine, isopropanolamine, and arginine, and these can be used alone or in combination.

  The amount of the N-acyl-L-acidic amino acid salt of component (a) used in the present invention is not particularly limited, but is preferably 6 to 20% by mass (hereinafter simply referred to as “%”), more preferably Is 6-12%. Within this range, a good cleaning effect can be realized without impairing the stability over time.

  The component (b) silicic acid used in the present invention gels the component (a) and imparts an appropriate viscosity to the cleaning material. The particle size of the component (b) is not particularly limited, but in order to exhibit good gelling ability, those having an average primary particle size of 1 to 50 nm are preferable. Specifically, for example, fumed silicic acid obtained by hydrolyzing silicon tetrachloride in hydrogen and oxygen flame can be used. Commercially available products include AEROSILOX 50, AEROSIL 50, AEROSIL 90G, AEROSIL 130, AEROSIL 200, AEROSIL 200V, AEROSIL 200CF, AEROSIL 200 FAD, AEROSIL 300, AEROSIL 300CF, AEROSIL 380, AEROSIL 380S (manufactured by Nippon Aerosil Co., Ltd.).

  The compounding quantity of the silicic acid anhydride of the component (b) used for this invention is 1-20%, More preferably, it is 5-10%. If it is this range, the viscosity which is easy to use without temperature dependency can be provided, without impairing temporal stability. If the blending amount is less than 1%, sufficient viscosity cannot be imparted, and stability over time is not good. On the other hand, when the blending amount exceeds 20%, the hardness is remarkably increased, which is not preferable.

  The acrylic acid / dimethyldiallylammonium chloride / acrylamide copolymer of component (c) used in the present invention not only makes the weakly acidic gel-like skin cleanser excellent in foaming and foam retention, but also into the skin after washing. It is blended for the purpose of adsorbing and imparting smoothness. Component (c) is not particularly limited as long as it can be used in cosmetics, but as a commercial product using water as a solvent, Marcoat Plus 3330, Marcoat 3331 (all manufactured by Calgon Co., Ltd.) and the like are available. Can be mentioned. Marquat Plus 3330 is a terpolymer composed of acrylic acid: dimethyldiallylammonium chloride: acrylamide = 25: 50: 25, and Marquat Plus 3330 is a molar ratio of 17:45:38. Provided as a commercial product. These can be used alone or in combination of two or more.

  The compounding amount of the component (c) in the weakly acidic gel-like skin cleanser of the present invention is 0.05 to 1% as a pure component, and more preferably 0.05 to 0.5%. Within this range, not only excellent foaming and foam retention, but also an excellent effect of imparting smoothness to the washed skin can be obtained. If the blending amount is less than 0.05%, good foaming and foam retention cannot be imparted, and skin smoothness cannot be obtained. On the other hand, if the blending amount exceeds 1%, foaming is slow and the cleaning effect is also reduced.

  When the weakly acidic gel-like skin cleanser of the present invention is further mixed with a liquid ester oil at 25 ° C. as component (d), the skin after washing can be made smoother. Such a component (d) is an ester of a fatty acid and a monovalent, divalent, or polyhydric alcohol and exhibits a liquid state at 25 ° C. Specific examples include isopropyl myristate, isopropyl palmitate, octyldodecyl myristate, cetyl 2-ethylhexanoate, glyceryl tri-2-ethylhexanoate, diglyceryl triisostearate, and the like. More than one species can be appropriately selected or used in combination. Of these, cetyl 2-ethylhexanoate and glyceryl tri-2-ethylhexanoate are preferable from the viewpoint of smoothing the skin after washing and reducing the squeaky feeling derived from silicic anhydride.

  As for the compounding quantity of the component (d) in the weak acidic gel-like skin cleansing material of this invention, 0.1 to 5% is preferable. When the blending amount of component (d) is within this range, it is preferable because better detergency and smooth skin after use are obtained without inhibiting foaming.

  In addition to the above components, the weakly acidic gel-like skin cleansing agent of the present invention includes fragrances, dyes such as dyes and pigments, antiseptics, bactericides, anti-inflammatory agents, chelating agents, viscosity modifiers, foaming agents, and foam stabilizers. An agent, a wetting agent, a super fat agent, a pearl agent, various drugs, and the like can be blended. The weakly acidic gel-like skin cleanser of the present invention can be applied to facial cleansers, body cleansers and the like.

  The following examples further illustrate the present invention. In addition, these do not limit this invention at all.

Invention products 1 to 7 and comparative products 1 to 7: Weakly acidic gel-like skin cleanser Weakly acidic gel-like skin cleanser was prepared by the composition shown in Table 1 and the following production method. The obtained gel-like skin cleanser was used as (1) stability over time (drainage) and feeling of use: (2) foaming during use, (3) foam retention during use, (4) skin after use The smoothness was evaluated by the following method, and the results are shown in Table 1 and Table 2.

(Manufacturing method)
A: Components 1 to 10 and 13 to 14 are mixed uniformly.
B: Components 11 to 12 were added to and mixed with A to obtain a weakly acidic gel-like skin cleanser.

(Evaluation method 1)
20 female evaluation panels were subjected to each evaluation by taking 3 g of the weakly acidic gel-like skin cleansing material of the present invention and the comparative product and lathering with a palm in a suitable amount of water at 25 ° C. (2) Foaming during use, (3) Foam retention during use, and (4) Smoothness of skin after use are evaluated on a five-point scale based on the following (a) evaluation criteria, and the average score of each sample The value was determined using (b) a 4-step criterion.

(A) Five-level evaluation criteria (score) (Evaluation)
4: Very good 3: Good 2: Normal 1: Slightly bad 0: Poor (b) Four-step criteria (rating) (Judgment)
3.0 or more: ◎
2.5 or more and less than 3.0: ○
1.0 or more and less than 2.0: △
Less than 1.0: ×

(Evaluation method 2)
The weakly acidic gel-like skin cleansing material of the present invention and the comparative product were allowed to stand at 40 ° C., and the presence or absence of drainage of the sample after being allowed to stand for 1 month was determined according to the following (c) 4-step evaluation criteria.

(C) Four-level evaluation criteria [Evaluation] [Decision]
There is no drainage ◎
Slight drainage is seen ○
Drainage is too large for use ×

As is apparent from the results of Tables 1 and 2, the products 1 to 7 of the present invention are all items of foaming during use, feel during use, smoothness of the skin after washing, and stability over time (drainage). It was an excellent weakly acidic gel-like skin cleanser. On the other hand, Comparative product 1 in which component (a) N-acyl-L-acidic amino acid salt was not blended was not sufficient in terms of foaming during use, foam retention and smoothness after use. . Further, Comparative Product 2 in which component (c) acrylic acid / dimethyldiallylammonium chloride / acrylamide copolymer was not blended was not sufficient in terms of foaming during use, foam retention and smoothness after use. On the other hand, the comparative product 3 in which the component (b) silicic anhydride was less than the predetermined amount did not form a gel state and could not be evaluated. Comparative product 4 having a large amount of component (c) acrylic acid / dimethyldiallylammonium chloride / acrylamide copolymer was not sufficient in terms of foaming. Moreover, in comparative product 5 with a large amount of component (b) silicic acid anhydride, foaming during use and smoothness of the skin after use were remarkably lacking. In comparative product 6 in which the blending amount of component (c) acrylic acid / dimethyldiallylammonium chloride / acrylamide copolymer is less than a predetermined amount, average particle size is not component (b) due to poor foaming and smooth skin after use. In Comparative Product 7 containing silicic acid anhydride having a large diameter, no gel was formed.

Weakly acidic gel skin cleanser (component) (%)
(1) N-lauroyl glutamic acid triethanolamine 20.0
(2) Palm oil fatty acid diethanolamide 5.0
(3) Lauryldimethylaminoacetic acid betaine 8.0
(4) Polyoxyethylene polyoxypropylene monobutyl ether * 1 1.0
(5) Lauryldimethylaminoacetic acid betaine 10.0
(6) Glyceryl tri-2-ethylhexanoate 3.0
(7) Acrylic acid, dimethyldiallylammonium chloride,
Acrylamide copolymer * 2 3.0
(8) Cationized cellulose 0.5
(9) Purified water Remaining amount (10) Silicic anhydride (average primary particle size 10 nm) 9.0
(11) Orange oil 0.5
* 1: Unilube 50MB-168 (Nippon Yushi Co., Ltd.)
* 2: Marcote Plus 3331 (Calgon)

(Manufacturing method)
A: The components 1 to 9 are dissolved by heating and then cooled.
B: Components 10 and 11 were added to A and mixed uniformly to obtain a weakly acidic gel-like skin cleanser.
The skin cleanser of Example 2 was a gel-like skin cleanser with good stability over time, foaming / foaming during use, and excellent smoothness after cleaning.

Claims (3)

The following components (a) to (c);
(A) N-acyl-L-acidic amino acid salt (b) 1-20% by mass of silicic anhydride
(C) Acrylic acid / dimethyldiallylammonium chloride / acrylamide copolymer 0.05-1% by mass
A weakly acidic gel-like skin cleanser characterized by comprising   The weakly acidic gel-like skin cleanser according to claim 1, wherein the component (a) is N-lauroyl-L-aspartate.   The weakly acidic gel-like skin cleanser according to claim 1 or 2, further comprising 0.1 to 5% by mass of an ester oil that is liquid at 25 ° C as component (d).