JP2001019632A - Weakly acidic skin cleansing preparation - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject skin cleansing preparation causing no rise in hardness with time at room temperature and lower temperatures, thereby even in the case where a tube is packed with a pasty skin cleansing preparation, freed from such a critical problem as to get hard to extrude the content from such a tube after left to stand at room temperature or lower temperatures, and excellent in (quick) foamability, foam creaminess, rinsability, refreshing feel and dampishness after cleansing. SOLUTION: This skin cleansing preparation which is preferably pasty is obtained by including pref. 5-50 wt.% of an N-acylamino acid alkali salt (pref. N-acylglycine salt), pref. 0.1-30 wt.% of a betaine-based amphoteric surfactant, water and an organic acid.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a skin cleanser. More particularly, the present invention relates to a weakly acidic skin cleanser which does not increase in hardness with time or at a low temperature and greatly improves the ease of taking out of the tube.

[0002]

2. Description of the Related Art Conventionally, soaps, which are alkali salts of fatty acids, have been used as a cleaning base for the purpose of cleaning the skin.

[0003] Soaps are excellent in cleaning effect, and have excellent effects of giving creamy and rich lather, quick lathering and refreshing feeling when washing the skin, which is desirable for cleansing foams, bath soaps, face soaps. It is widely known that it is applied to many skin cleansing agents.

[0004]

However, on the other hand, on the other hand, it is difficult to give a moist and pleasant skin feeling after washing, because the feeling of refreshing and refreshing is too strong, and various oils and synthetic surfactants are contained in the washing agent. However, even if the formulation was adjusted or the formulation was adjusted to adjust the amount of soap, the moist skin feeling after washing could not be obtained.

[0005] Another characteristic that consumers demand from skin cleansing agents is that they are weakly acidic, close to the pH of bare skin. I couldn't meet my needs.

On the other hand, it has an excellent cleansing effect, gives a creamy and rich lather, a quick lather and a refreshing feeling, which is favorable when washing the bare skin, and is excellent in moist skin feel after washing. In order to obtain a weakly acidic skin cleanser that meets the needs of the above, as a washing base other than soap, an alkali salt of acyl glutamate, an alkali salt of acyl sarcosine, an alkali salt of alkyl sulfosuccinate, an alkali salt of alkyl phosphate, and the like are used. Have been.

[0007] However, when a paste-like skin cleanser is prepared using the above-mentioned cleansing base, there is a fatal problem that the hardness increases with time at room temperature or low temperature, and it becomes difficult to remove from the tube.

In view of the above-mentioned problems, the present inventors have conducted intensive studies to develop a cleaning agent which does not cause a problem that the hardness increases with time at room temperature or low temperature, thereby preventing the cleaning agent from being hardly removed from the tube. The present inventors have found that a weakly acidic skin cleanser containing an N-acylamino acid-based surfactant and a betaine-based surfactant can satisfactorily solve the above problems, and have completed the present invention.

An object of the present invention is to provide a weakly acidic skin cleansing agent which solves the problem of the prior art that the hardness increases with time at room temperature or low temperature and it is difficult to remove the tube from the tube.

[0010]

That is, the present invention provides an
-To provide a weakly acidic skin cleanser characterized by containing an alkaline salt of an acyl amino acid, a betaine-based amphoteric surfactant, water and an organic acid.

[0011] The present invention also provides the above-mentioned weakly acidic skin cleanser, wherein the alkali salt of N-acylamino acid is an N-acylglycine salt.

Further, the present invention provides the above betaine-based amphoteric surfactant, which is represented by the following chemical formulas (1), (2), (3):
The present invention provides the above-mentioned weakly acidic skin cleansing agent, which is one kind or two or more kinds represented by any of (4). (1) (2) (3) (4) (In the formula, R ₁ is an alkyl group or alkenyl group having about 8 to 21 carbon atoms, R ₂ and R ₃ are alkyl groups having 1 to ₃ carbon atoms, and n is an integer of 1 to 4.)

Further, the present invention provides a paste-like composition containing 5 to 50% by weight of an alkali salt of N-acylamino acid and 0.1 to 30% by weight of a betaine amphoteric activator based on the total amount of the weakly acidic skin cleanser. It is intended to provide the above-mentioned weakly acidic skin cleanser characterized by the following.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The configuration of the present invention will be described below in detail.

The alkali salt of N-acylamino acid used in the present invention is a compound known as an N-acylamino acid-based surfactant, and provides excellent stability in the present invention.
It is a surfactant that has good familiarity with dirt, has a clean and refreshing feel when washed with water, is easy to wash off, and gives a moist skin feel after use.

The acylated moiety of the N-acyl amino acid (RC
The carbon number of O-) is preferably from 10 to 18,
More preferably, it is 12-14. When the number of carbon atoms is less than 10, the viscosity of the preparation decreases and foaming also decreases, and
If it exceeds 8, the hardness of the preparation increases and the foaming decreases.
In addition, although it can be used irrespective of linear, branched and saturated or unsaturated, a linear chain is preferred in terms of foaming, and a saturated one is preferred in terms of stability of the preparation. Particularly preferred are a linear acyl group having 12 carbon atoms and a coconut oil fatty acid acyl group containing the same as a main component.

Regarding the amino acid site, glutamic acid,
Alanine, glycine and the like are preferred, and N-acylglycine salts are most preferred in view of foaming, formulation and the like.

As the alkali salt, for example, a sodium salt and a potassium salt are preferable, and a sodium salt is most preferable in consideration of foaming, formulation and the like.

The amount of the N-acylamino acid alkali salt varies depending on the intended dosage form of the skin cleanser, but 1 to 20% by weight of the total amount of the skin cleanser and 1 to 20% by weight of the skin cleanser. 5 to 50% by weight, 40 in solid form
About 90% by weight. Creamy and rich foaming,
In consideration of quick bubbling, quick bubbling, and simplicity of use, a paste containing 10 to 40% by weight is particularly preferable.

The betaine amphoteric surfactant used in the present invention is a known surfactant represented by the above chemical formulas (1), (2), (3) and (4).
N-carboxymethylammonium betaine, 2-alkyl-1-hydroxyethylimidazoline betaine sodium, alkyldimethylaminoacetic acid betaine, alkylimidazolinium betaine, coconut fatty acid amide propyl betaine, coconut oil alkyl betaine, lauryl dimethylamino-2-hydroxy Propylsulfobetaine,
Lauryl amide propyl betaine, lauryl dimethylaminopropyl sulfo betaine and the like can be mentioned. These surfactants may be used alone or in combination of two or more.

In the present invention, the betaine-based amphoteric surfactant is easily removed from the tube by suppressing and increasing the hardness at room temperature and low temperature in a paste-like detergent mainly containing an N-acylamino acid-based surfactant. And also improves the fast-bubble properties.

The content of the betaine surfactant is preferably 0.1 to 30% by weight based on the total amount of the skin cleanser. 0.
If the content is less than 1% by weight, the effect cannot be sufficiently exhibited.
Even if it exceeds 0% by weight, no further increase in the effect can be expected.
It is economically disadvantageous and is not preferable in terms of stability and safety. In consideration of the effect of suppressing an increase in hardness and the simplicity of use, a paste containing 0.5 to 15% by weight is particularly preferable.

In the present invention, one or more selected from the group consisting of lower alcohols, polyhydric alcohols, ethylene glycol adducts of polyhydric alcohols, and propylene oxide adducts of polyhydric alcohols, in addition to the above essential components. It is preferable that a water-soluble compound having at least one kind of hydroxyl group is blended. Specifically, for example, ethyl alcohol, isopropyl alcohol, butanol, propylene glycol, isopropyl glycol, 1,3 butanediol, dipropylene glycol, glycerin, diglycerin, polyglycerin, trimethylolpropane, erythritol, pentaerythritol, sorbitan, Sorbitol glucose, maltitol, saccharose,
Examples include trehalose, fructose, and derivatives thereof such as ethylene oxide adducts and propylene oxide adducts. Glycerin or 1, in terms of fully exerting all effects on cleaning effect, creamy and rich foaming, quick foam removal, clean, refreshing feeling of use, moist skin feel after washing, base stability 3-butanediol is most preferably compounded.

The amount of the water-soluble compound having a hydroxyl group is as follows:
It is preferably 1 to 40% by weight based on the total amount of the skin cleanser,
Particularly preferably, it is 5 to 20% by weight.

The weakly acidic skin cleanser of the present invention may contain a small amount of oil. The use of an oil component slightly reduces the feeling of use such as a refreshing feeling and a refreshing feeling, but enhances the moist feeling after washing. The oil content here refers to, for example, hydrocarbons, higher alcohols, higher fatty acids, higher alcohol higher fatty acid esters, animal and vegetable oils and fats, cholesterol fatty acid esters, silicones, and the like. Specifically, liquid paraffin, polyisobutene , Isostearyl cholesteryl ester, 2-ethylhexanoic acid triglyceride, 2-ethylhexanoic acid hexadecyl, myristate octadecyl, olive oil,
A chain or cyclic methylpolysiloxane may, for example, be mentioned.

The weakly acidic skin cleansing composition of the present invention contains water and an organic acid such as citric acid to make the pH weakly acidic, in addition to the above-mentioned components. The amounts of water and organic acid are determined appropriately according to the dosage form of the skin cleanser.

The skin cleansing composition of the present invention is usually used in combination with other ingredients such as a thickener, an ionic surfactant, a medicinal agent, and a moisturizing agent as long as the effects of the present invention are not impaired. Ingredients, anti-inflammatory agents, bactericides, preservatives, ultraviolet absorbers, antioxidants, organic and inorganic powders, pigments, fragrances, etc. are added as necessary and manufactured according to the desired dosage form according to the conventional method. You.

[0028]

Next, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples. In the following examples, the compounding amount represents% by weight.

<Example 1> Paste detergent N-acylglycine sodium salt 20 coconut oil fatty acid amidopropyl betaine 2 glycerin 30 propylene glycol 5 thickener proper amount citric acid proper amount preservative proper amount water residue

<Comparative Example 1> Paste detergent N-acylglycine sodium salt 20 glycerin 30 propylene glycol 5 thickener proper amount citric acid proper amount preservative proper amount water residue

<Example 2> Paste detergent N-acylglutamic acid sodium salt 30 coconut oil fatty acid amidopropyl betaine 5 glycerin 5 propylene glycol 5 polyethylene glycol 1 citric acid proper amount water residue

Comparative Example 2 Paste-like detergent N-acylglutamic acid sodium salt 30 glycerin 5 propylene glycol 5 polyethylene glycol 1 citric acid proper amount water residue

<Example 3> Paste detergent N-acylalanine sodium salt 30 coconut oil fatty acid amidopropyl betaine 5 glycerin 5 propylene glycol 5 polyethylene glycol 1 citric acid proper amount water residue

Comparative Example 3 Paste detergent N-acylalanine sodium salt 30 glycerin 5 propylene glycol 5 polyethylene glycol 1 citric acid proper amount water residue

Example 4 Pasty detergent N-acylglycine sodium salt 30 alkyldimethylaminoacetate betaine 10 glycerin 30 propylene glycol 5 polyethylene glycol 1 citric acid suitable amount water residue

<Comparative Example 4> Paste detergent N-acylglycine sodium salt 30 glycerin 30 propylene glycol 5 polyethylene glycol 1 citric acid proper amount water residue

<Example 5> Pasty detergent N-acylglycine potassium salt 30 alkyl imidazolinium betaine 3 glycerin 30 propylene glycol 5 polyethylene glycol 1 citric acid appropriate amount water residue

<Example 6> Paste detergent N-acylglycine sodium salt 20 coconut oil fatty acid amidopropyl betaine 3 glycerin 30 propylene glycol 5 thickener proper amount citric acid proper amount preservative proper amount water residue

<Example 7> Paste detergent N-acyl-glycine sodium salt 30 stearyl dimethyl betaine 8 glycerin 30 propylene glycol 5 polyethylene glycol 1 citric acid proper amount water residue

[Preparation method] The above components were added to a main kettle,
Mix uniformly with a high-speed mixer under heating conditions of up to 80 ° C. After defoaming, filtering and cooling, it is used as a weakly acidic skin cleanser.

[Measurement of change with time in hardness] Comparative Example 1 (betaine surfactant: 0% by weight), Example 6 (betaine surfactant: 1% by weight), Example 1 (betaine surfactant: 2) % By weight), Example 7 (betaine-based surfactant: 3)
(% By weight) in a thermostat at 25 ° C. and 0 ° C., and a change in hardness over time (immediately after, 1, 2, 3, 4 weeks) was measured. The hardness is measured by applying a load that increases at a constant speed with a card tension meter (load: 200 g, pressure-sensitive shaft: 8Φ), presses a needle (pressure-sensitive shaft: 8Φ) with a fixed area, and determines the point at which the pressure-sensitive shaft comes to rest. Hardness.

[Measurement of Temporal Hardness Change] FIG. 1 shows the temporal hardness change of each sample. As is clear from FIG. 1, in Comparative Example 1 (coconut oil fatty acid amide propyl betaine: 0% by weight), the hardness increases with time at 0 ° C. An increase in hardness over time was suppressed (Examples 1, 6).
Even at room temperature, in Examples 1 and 6 in which the coconut oil fatty acid amidopropyl betaine was blended, the increase in hardness over time was suppressed.

[Evaluation Method and Evaluation Criteria] After washing and drying the bare skin of 18 healthy female panels (20 to 45 years old), 0.5 g of petrolatum was uniformly applied to the face, and 30 minutes later, 0 g
℃, 25 ° C. was washed in a constant temperature layer for one week using the examples and comparative examples, easy to get out of the tube, fast foaming,
Foaming, foamy creaminess, ease of rinsing, refreshing feeling,
The moist feeling after washing the face was evaluated. In each evaluation, the evaluation was made based on the following criteria based on an average score of 18 persons, with the evaluation score being 100 points. The results are shown in Table 1.

[Ease of taking out of tube] A: 75 or more evaluation points (very soft and easy to get out) O: 50 to 74 points (soft and easy to get out) Δ: 25 to 49 points (somewhat) ×: Less than 25 evaluation points (too hard and not at all) [Fast foaming property] ；: 75 points or more (bubbles very quickly) ○: 50 to 74 points (bubbles quickly) ): Evaluation point 25 to 49 points (slow foaming) ×: Less than 25 points (slow foaming) [Bubbling] ；: 75 points or more (very good foaming) ○: Evaluation Points 50 to 74 points (bubble well) Δ: Evaluation points 25 to 49 (slightly poor bubbling) ×: Less than 25 points (bad bubbling) [Creamy of foam] ◎: 75 points (Very creamy) ○: 50 to 74 evaluation points ( Reamy.) Δ: Evaluation point 25 to 49 points (slightly creamy) ×: Evaluation point less than 25 points (not creamy at all) [Easy rinsing] ；: Evaluation point 75 points or more (very easy to rinse) ○ Evaluation point: 50 to 74 points (easy to rinse) Δ: Evaluation point: 25 to 49 points (easy to rinse) ×: Less than 25 points (very difficult to rinse) [Refreshing feeling] ；: Evaluation point of 75 points or more (Very refreshed.) ○: 50 to 74 evaluation points (refreshed) Δ: 25 to 49 evaluation points (feeling a little left behind) ×: Less than 25 evaluation points (very much later) Feel the rest.) [Moist feeling after face washing]: Evaluation point of 75 points or more (very moist) ○: Evaluation point of 50 to 74 points (moist) Δ: Evaluation point of 25 to 49 points (slightly moist) No; ×; Point less than 25 points (all not moist.)

[0045]

[Table 1]

In Table 1, Comparative Example 1, Comparative Example 2,
In Comparative Examples 3 and 4, in each of Comparative Examples, there is a fatal problem in the ease of taking out of the tube at a low temperature (0 ° C.), whereas Examples 1, 2, and 3 are problematic. In Example 4, there is no problem at all, and the ease of taking out of the tube at room temperature (25 ° C.) and the quick foaming property are also improved. Further, in Examples 1 to 4, since the hardness of each paste-like cleaning agent was improved, the solubility in water was also improved, and the quick foaming property and foaming were also improved.

These effects are observed in any of the examples using the N-acylamino acid salt. In particular, in the examples using the N-acylcriricine salt (Examples 1 and 4), 0% was obtained. Extremely easy to get out of the tube at 25 ° C and 25 ° C. In addition, fast foaming, foaming, creaminess,
Excellent effects are also exhibited in items such as ease of rinsing, refreshing feeling, and moist feeling after washing.

[0048]

According to the present invention, there is no increase in hardness over time at room temperature and low temperature, and even when a paste-like skin cleanser is filled in a tube, it is difficult to remove the contents from the tube at room temperature and low temperature. It is possible to provide a weakly acidic skin cleansing agent which can solve a fatal problem and has a quick bubbling, a creamy and rich bubbling, a quick bubbling, a refreshing feeling of use of skin washing, and a moist skin feel after washing.

[Brief description of the drawings]

BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is a diagram illustrating a change in hardness over time of an example and a comparative example at 0 ° C. and 25 ° C.

 ──────────────────────────────────────────────────の Continued on the front page (72) Shin Nakamura, Inventor 1050 Nippa-cho, Kohoku-ku, Yokohama, Kanagawa Prefecture Inside Shiseido Daiichi Research Center Co., Ltd. (72) Yumiko Fujiwara 1050 Nippa-cho, Kohoku-ku, Yokohama, Kanagawa F-term in Shiseido Daiichi Research Center Co., Ltd.

Claims (4)

[Claims] 1. A weakly acidic skin cleanser comprising an alkali salt of N-acylamino acid, a betaine-based amphoteric surfactant, water and an organic acid. 2. The method according to claim 2, wherein the alkali salt of the N-acylamino acid is
2. An N-acylglycine salt,
The weakly acidic skin cleanser according to the above. 3. The betaine-based amphoteric surfactant is one or more of the following chemical formulas (1), (2), (3) and (4). The weakly acidic skin cleanser according to claim 1. (1) (2) (3) (4) (In the formula, R ₁ is an alkyl group or alkenyl group having about 8 to 21 carbon atoms, R ₂ and R ₃ are alkyl groups having 1 to ₃ carbon atoms, and n is an integer of 1 to 4.) 4. A paste containing 5 to 50% by weight of an alkali salt of N-acylamino acid and 0.1 to 30% by weight of a betaine-based amphoteric active agent based on the total amount of the weakly acidic skin cleanser. The weakly acidic skin cleanser according to claim 1, 2, or 3.