JPS588007A - Cosmetic for making skin soft - Google Patents

Abstract

PURPOSE:A cosmetic for making the skin soft having weak acidity of pH of the skin, safe in skin science, having improved preserving properties of corneum, flexibility, capable of keeping softening effect for extremely long time, comprising a specific hydroxy acid and a basic amino acid. CONSTITUTION:The titled cosmetic obtained by blending a hydroxy acid having 2-18C in the molecule with a basic amino acid in a molar ratio of (1:0.5)- (0.5:1), preferably (1:0.7)-(0.7:1). The concentration of a mixture of the hydroxy acid and the basic amino acid in the cosmetic is 1-10wt%. Glycolic acid, lactic acid, hydroxybutyric acid, hydroxyvaleric acid, hydroxycaproic acid, hydroxycaprylic acid, citric acid, tartaric acid, etc. may be cited as the hydroxy acid. Lysine, alginine, histidine, ornithine, etc. may be cited as the basic amino acid.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a skin softening cosmetic containing an oxyacid having a hydroxyl group and a carboxyl group in its molecule and a basic amino acid.

The outermost layer of the skin, the stratum corneum, often becomes dry and rough during harsh weather conditions such as winter, low temperature, and low humidity. This can also occur with excessive use of detergents and solvents. This skin change is caused by the loss of a hygroscopic, water-soluble component called NMF (natural moisturizing factor) in the stratum corneum, resulting in a decrease in moisture in the stratum corneum and loss of flexibility of the stratum corneum. It is believed that this is for the purpose of Therefore, conventional cosmetics for softening the skin have been formulated with various moisturizing agents in order to provide as much moisture as possible to the stratum corneum and retain it for a long time. Furthermore, a method utilizing the stratum corneum softening effect of α-oxyacid has also been proposed. (Japanese Patent Publication No. 55-19291) However, when a moisturizer is applied to the skin, its effect is temporary and not permanent. Also,
The application of α-oxyacids has many drawbacks, such as the effect is only expressed in a low pH range (PH2-4) that inhibits normal skin physiology.To compensate for this drawback, sodium hydroxide and hydroxide There have been cases where strong alkalis such as potassium or amines such as triethanolamine were added to achieve a neutral pH range, but these strong alkalis tend to be unstable when added in large amounts, and may affect the pH of the skin. It is difficult to adjust the quality to the target area, and it is difficult to obtain a certain level of quality. Furthermore, as seen in the literature, it is known that long-term use of amines can cause allergies in some people, so it is preferable to use other neutralizing agents.

In order to solve these drawbacks, the present inventors have conducted extensive research and have discovered that NM
By incorporating basic amino acid, which exists as a free amino acid in F and is dermatologically proven to be safe,
It is weakly acidic (PH4.5-7), which is the pH of the skin, and is dermatologically extremely safe compared to conventional cosmetics.It has excellent retention and flexibility of the stratum corneum, and has an extremely long-lasting softening effect. They have discovered and completed a cosmetic that can last for a long time.

That is, the present invention provides a skin softening cosmetic characterized by containing an oxyacid having 2 to 3 carbon atoms in the molecule and a basic amino acid.

According to the present invention, by combining a basic amino acid with an oxyacid, the hygroscopicity is significantly improved compared to the oxyacid alone, and the amount of moisture imparted to the stratum corneum is increased.As a result, the stratum corneum of the skin is softened and , can exhibit the effect of supporting the normal replacement of corneocytes.

Next, the configuration of the present invention will be described. The oxyacids used in the present invention include, for example, glyfuric acid, lactic acid, oxybutyric acid, oxyvaleric acid, oxycaproic acid/oxyundic acid, oxycaprylic acid, oxycapric acid, oxyundecic acid, oxylauric acid, oxytridecanoic acid, These are oxyacids having 2 to 3 carbon atoms in the molecule, such as oxytradecanoic acid, oxypentadecanoic acid, oxybalmicinic acid, oxycapric acid, oxystearic acid, mandelic acid, citric acid, tartaric acid, and malic acid.

The basic amino acids used in the present invention include, for example, lysine, arginine, histidine, ordigane, canavanine, and the like.

The ratio of oxyacid to basic amino acid is molar ratio]: α5
~α5:1, but preferably a ratio close to equivalence such as l;α7 to α7;1. The concentration of the mixture of oxyacid and basic amino acid contained in cosmetics ranges from 0.1 to 0.01 by weight.
%, preferably 1N1D%.

In the present invention, the oxyacid and the basic amino acid may be blended as a salt.

In addition to the above-mentioned essential ingredients, the skin softening cosmetic composition of the present invention may optionally contain bases commonly used in cosmetic compositions, such as surfactants, oils, humectants, and water.

Next, the present invention will be explained in more detail with reference to Examples. In addition, the blending amounts are weight % unless otherwise specified.

Example 1 α-oxycaprylic acid 0.15M α249 Lysine O, 15M 21.99 Water
ets
4.1 (i Comparative Example 1 α-oxycaprylic acid α15M 24.□i7 Water 9
76.09 Manufacturing method Dissolve α-oxycaprylic acid and lysine 21.9 in water, and add water so that the total amount is xooo 9.

Aqueous solution containing oxycarginic acid and basic amino acids (
Moisturizing properties of the pH 1 stratum corneum of Example 1) and an aqueous solution containing only oxycarboxylic acid (Comparative Example 1) - After sufficient immersion, the stratum corneum was left to stand in the measurement humidity, and when a constant weight was reached, the stratum corneum The amount of water (■) in 100 Wui was expressed as the amount of moisture absorbed.

The softening effect was measured by applying 2 μm of the test aqueous solution to a 2) a x 5m811 piece of the stratum corneum, and measuring the elastic modulus using a dynamic viscoelasticity measuring device manufactured by Toyo Seiki.

The flexibility effect is determined by the elastic modulus (E) of the stratum corneum measured as a blank.
), the elastic modulus (Ict
) is expressed as the ratio E/Et.

The results are shown in Table 1 and Figure 1.2.

Table 1, pH of Example 1 and Comparative Example 1 pH Example 1 6.58 Comparative Example 12-40 As is clear from Table 1, Example 1 is compared to Comparative Example 1.The pH is neutral. It's nearby. This indicates that the addition of basic amino acids increased the physiological safety of the skin. Furthermore, the amount of moisture absorbed by the stratum corneum after each of the aqueous solutions of Example 1 and Comparative Example 2 was applied to the stratum corneum was greatly improved by the addition of the basic amino acid, as is clear from FIG.

On the other hand, it is clear from FIG. 2 that the softening effect on the stratum corneum is also significantly increased by the addition of basic amino acids.

(Left below) Example 2 Soft lotion citric acid 2-8 lysine a2 glycerin
3.0 propylene glycol
40 dipropylene glycol
40 polyoxyethylene (pressure/I/) sorbitan monolaurate
15 ethyl alcohol
lα0 distilled water '13
Fragrance αl preservative
αl (Production method) Add citric acid, lysine-glycerin, propylene glycol, and dipropylene glycol to distilled water and dissolve at room temperature (Suito). Add polyoxyethylene sorbitan monolaurate fragrance and preservative to ethyl alcohol and dissolve at room temperature (alcohol part). Add an alcohol part to Suito to obtain a softening lotion.

The obtained softening lotion has an excellent moisturizing effect on the stratum corneum,
It showed a softening effect.

Example 3 W10 type emulsion microphone 4 crystalline wax 1
．． 0 beeswax zO silanone 20 liquid paraffin
30.0 Sorbitan sesquioleate 40 Polyoxyethylene sorbitan monooleitate (20EQ) 1.0 Aluminum stearate 0
．． 2 Lactic acid 1.7 Fulgiene 2.6 Distilled water
55.4 Fragrance
α4 preservative
0.4 (Production method) Add lactic acid and arginine to distilled water, heat and maintain at 70°C (aqueous phase). Mix other ingredients and heat to dissolve and maintain at 70'C (oil phase). While stirring the oil phase, gradually add the water phase to it and uniformly emulsify with a homomixer. After emulsification, cool to 30'C while stirring.

The obtained emulsion exhibited excellent moisturizing and softening effects on the stratum corneum.

Example Beef Q/W type mulberry cream wax lα0 cetyl alcohol 50 hydrogenated/phosphorus
aO squalane
37.5 Glyceryl monostearate zO polyoxymorsi (2
0 mol) Sorbitan monolaurate
2.0 Propylene Glycol 5.0 Oxystearic Acid 47 Lysine
z2 distilled water
259 fragrance ・
α5 preservative
α5 (Production method) Distilled water, propylene glycol, oxystearic acid,
Add lysine, heat and keep at 70°C (water phase). Mix other ingredients, heat and dissolve and keep at 70°C (oil phase).

Pre-emulsify by adding the oil phase to the water phase. Uniformly emulsify with a homomixer, and after emulsification, stir while cooling.

The obtained emulsion exhibited excellent moisturizing and softening effects on the stratum corneum.

[Brief explanation of drawings]

FIG. 1 is a graph showing the moisturizing properties of the stratum corneum treated with Example 1, Comparative Example 1, and distilled water. FIG. 2 is a graph showing the softening effect on the stratum corneum of Example 1 and Comparative Example 1. Patent applicant Shiseido Co., Ltd.

Claims (1)

[Claims] (1) A skin softening cosmetic characterized by containing an oxyacid having 2 to 3 carbon atoms in its molecule and a basic amino acid.