JPH06157237A - Humectant and cosmetic, skin external agent containing the same - Google Patents

Abstract

PURPOSE:To provide the highly safe humectant excellent in the moisture-holding force and in the moisture-absorbing force, and giving the cosmetic and the cosmetic external agent good in the using touch when coated, giving a wet touch to skin and hair but not giving a sticky, slimy and tensive touch. CONSTITUTION:The humectant contains the metal salt, alkanolamine salt or same salt of polyaspartic acid produced by polymerizing L-aspartic acid, D- aspartic acid or their mixture through alpha or beta bonds and preferably having an average mol.wt. of 5000-50000. The humectant is added to various products usually in amounts of 0.01-50wt.%, preferably 0.05-10wt.%.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a moisturizing agent containing a polyaspartic acid salt, and the object of the present invention is to provide a highly safe moisturizing agent and cosmetic having excellent moisturizing power and hygroscopic power, An object is to provide a skin external preparation.

[0002]

2. Description of the Related Art Moisturizers have the ability to prevent evaporation of moisture (moisture retaining power) and the ability to absorb moisture (moisture absorbing ability), and it is required to combine these properties at the same time. However, few moisturizers generally used have satisfactory moisturizing power and hygroscopic power, and in many cases, they are used in combination.

Low molecular weight moisturizers such as sodium lactate, sodium pyrrolidonecarboxylate (PCA-Na), glycerin, and sorbitol have high hygroscopicity as a whole, but have a drawback that they are inferior in moisturizing effect. Further, sodium lactate, PCA-Na, etc. are electrolytes and therefore have properties such as an emulsification-inhibiting action and are not suitable for emulsification systems. Polyol-based moisturizers such as glycerin, sorbitol, propylene glycol, butylene glycol are apt to cause stickiness and sliminess in products, and have difficulty in use when used in cosmetics.

Among high molecular weight moisturizers such as sodium hyaluronate and polyglutamates (Japanese Patent Laid-Open No. 59-209635), although the mucopolysaccharide sodium hyaluronate has a low hygroscopicity, it has a good feeling of use. It has recently attracted attention as an agent. However, since the raw materials are extremely expensive and the viscosity tends to be high when added in a small amount, it is difficult to prepare an aqueous solution, and its use is limited by itself. Further, polyglutamate also has a hygroscopic ability equal to or superior to that of sodium hyaluronate, but has a drawback that its moisturizing ability is slightly inferior.

[0005]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a moisturizer having both moisturizing power and hygroscopic power, a good feeling during use and a high safety.

[0006]

Means for Solving the Problems As a result of intensive studies to solve the above-mentioned problems, the present inventors have found that polyaspartate has superior hygroscopicity and moisturizing power as compared with conventionally known polyglutamates. The present invention has been completed by finding out that it has strength and is easy to use.

The present invention will be described in detail below. The polyaspartic acid salt used in the humectant of the present invention is L-aspartic acid, D-aspartic acid or a mixture thereof polymerized by α or β bonds. The average molecular weight is 1,000 to 100,000, but from the functional point of view, those of 5,000 to 50,000 are more excellent.

Polyaspartate is a polybasic acid,
The degree of neutralization of the salt used in the present invention is such that the pH of the aqueous solution is 3 to 13.
It can be arbitrarily selected within the range according to the purpose. As the salt, metal salts such as sodium, potassium, lithium and magnesium, ammonia salt, ethanolamine salt,
Alkanolamine salts such as diethanolamine salt and triethanolamine salt, and organic weak base salts such as basic amino acid salt are used.

As a method for obtaining the polyaspartate used in the present invention, a conventionally known method may be used. A solid-state polymerization method in which an amino acid is directly heated and condensed (for example, The Journal of the American Chemical Socie
ty, Vol. 82, p. 3745, 1960) has been known for a long time, and a mixture of α-bond and β-bond is obtained by the solid-state polymerization method. As a method for obtaining α-polyaspartate, ring opening of N-carboxylic acid anhydride of amino acid,
A method of decarboxylation polymerization (for example, Journal of Polymer Sci
ence, A14, 2065, 1976; JP-A-46
No. 27828), a method of polymerizing an active amino acid ester (JP-A-54-47799), and N-
A method of heat-polymerizing dithiocarbonylalkoxycarbonylamino acid (Japanese Patent Publication No. 45-9391) is known.

The moisturizing agent of the present invention exhibits excellent hygroscopicity and moisturizing ability as shown in Examples below, and also has excellent solubility in water, and after application due to the film forming ability derived from the polymer structure, Gives a moist feeling without stickiness,
Does not give a feeling of tightness. Therefore, the addition of the moisturizer of the present invention to a cosmetic or an external preparation for skin not only helps maintain and improve the quality, but also has the effect of imparting appropriate moisturizing and smoothness to the skin or hair after use.

Cosmetics containing the moisturizer of the present invention include face-wash cream, face-wash foam, cleansing cream, cleansing milk, cleansing lotion, massage cream, cold cream, moisture cream, lotion, lotion, pack, after-shaving cream. , Sunblock, suntan oil, body shampoo, hair shampoo, hair rinse, hair treatment, hair restorer, hair restorer, tic, hair cream, balm, hair liquid, set lotion, hair spray, hair dye, hair bleach, color rinse, Color spray, permanent wave liquid, press powder,
Loose powders, eye shadows, hand creams can be mentioned, and lotion agents, aerosol agents, jelly agents, liniment agents, pasta agents and the like can be applied regardless of the form of the product.

When the moisturizing agent of the present invention is added to various products, the moisturizing effect can be imparted depending on the amount added, but it is usually 0.01 to 50% by weight, preferably 0.05.
It may be used in an amount of 10 to 10% by weight.

The cosmetic or external preparation for skin of the present invention may contain, in addition to the polyaspartic acid salt, other moisturizing agents within a range not impairing the effect thereof.

The medicines to be added to the skin external preparation of the present invention include all the medicines to be added to the external medicines, such as analgesics, disinfectants, bactericides, antifungal agents, keratin softening / exfoliating agents, skin bleaching agents, and skin agents. Colorants, granulation agents, epidermal forming agents, dead tissue removers, corrosives, hair growth agents, dehydrating agents, sunscreens, antiperspirants, deodorants, hormones, vitamins and the like.

[0015]

EXAMPLES Next, the present invention will be described in more detail by way of examples. The blending amount in this example is% by weight.

Production Example 1 Synthesis of poly-α, β-L-sodium aspartate L-aspartic acid was placed in a flask, dispersed in liquid paraffin, heated to 180 to 200 ° C. and azeotropically dehydrated to give anhydrous poly. After obtaining aspartic acid, hydrolysis was performed in an aqueous sodium hydroxide solution to obtain the title compound. This compound had a molecular weight of about 30,000 by GPC method and an optical rotation [α] of −9.64 degrees.

Production Example 2 Synthesis of sodium poly-α, β-D, L-aspartate L-aspartic acid was placed in a flask, and 180-2 was added.
After heating at 50 ° C to obtain anhydropolyaspartic acid, hydrolysis was performed in an aqueous sodium hydroxide solution to obtain the title compound. This compound had a molecular weight of about 40,000 by GPC method and was not optically active.

Example 1 The humectant shown in Table 1 was dried under reduced pressure sufficiently and then at 25 ° C. for 35 minutes.
It was allowed to stand until the weight became constant in a thermo-hygrostat of relative humidity (RH), and the moisture absorption rate was measured. The results are shown in Table 1.
It can be seen that the humectant of the present invention has a higher hygroscopic power than sodium polyglutamate and sodium hyaluronate.

[0019]

[Table 1]

Example 2 The moisturizing agents shown in Table 2 were dried under reduced pressure at 25 ° C. and 65 ° C.
% RH for 7 days, then at 25 ℃ ・ 35% RH for 7 days.
The sample was allowed to stand for a day to measure the moisture retention rate. The results are shown in Table 2. Although the moisturizer of the present invention is slightly inferior to sodium hyaluronate, it is understood that it has superior moisturizing power to sodium lactate, low molecular weight wetting agents such as glycerin and sorbitol, sodium polyglutamate, and carboxymethyl chitin. .

[0021]

[Table 2]

Example 3 The feeling of use of the aqueous solution containing the moisturizer shown in Table 3 was evaluated. The results are shown in Table 3. The feeling of use was determined by the following method.

After applying 0.2 ml of the moisturizer aqueous solution to the forearms of 8 male and female panelists, stickiness, tightness and sliminess were evaluated by sensory evaluation. As for the evaluation criteria, a score of 2 when the feeling is favorable and a score of 1 when the feeling is slightly favorable,
The average was 0 points, the slightly unfavorable points were -1 points, and the unfavorable points were -2 points. The average of 5 grades was calculated and the result was displayed as follows. ◯: 1.0 to 2.0 Δ: −0.5 to 0.9 ×: −2.0 to −0.6

[0024]

[Table 3]

Example 7 The feeling of use of the composition containing the components shown in Table 4 was evaluated. The results are shown in Table 4. The feeling of use was determined by the following method.

The composition was applied to the forearms of 8 male and 8 female panelists.
After applying 2 ml, stickiness, tightness, and sliminess were evaluated by sensory evaluation. The evaluation criteria are as follows: 2 points when the feeling is favorable, 1 point when the feeling is preferable, 0 point when the feeling is normal, -1 point when the feeling is not preferable, and -2 when the feeling is not preferable.
It was a point. The average of 5 grades was calculated and the result was displayed as follows. ⊚: 1.5 to 2.0 ∘: 0.5 to 1.4 Δ: −0.5 to 0.4 ×: −2.0 to −0.6

[0027]

[Table 4]

USE EXAMPLE 1 Lotion A lotion was obtained by mixing and dissolving the component B shown in Table 5 at room temperature, adding the component A mixed and dissolved at room temperature with stirring, and filtering. This product had good storage stability, gave a smooth and moist feeling to the skin, and had no slimy, sticky, or tight feeling and was excellent in usability.

[0029]

[Table 5]

Use Example 2 O / W Moisture Cream Component D shown in Table 6 was dissolved by stirring, and component C was added and dissolved by heating at 75 ° C. Ingredient A which was heated and dissolved at 75 ° C in advance
Was added and pre-stirred. Emulsify with a homogenizer 40
The mixture was cooled to 0 ° C., component B was added, and the mixture was stirred and cooled to obtain an O / W type moisture cream. This product had good storage stability, gave a soft and moist feeling to the skin, and had no feeling of sliminess, stickiness, or tightness, and was excellent in usability.

[0031]

[Table 6]

Use Example 3 O / W Lotion The components (A) and (B) shown in Table 7 were each heated and stirred at 80 ° C. (B) was gradually added into the stirring component (A). The solution was stirred to 40 ° C. and cooled to room temperature. This product had a supple and moisturizing feel on the skin, good spreadability, no stickiness and no tightness, and was excellent in usability.

[0033]

[Table 7]

Use Example 4 Hair shampoo All the ingredients shown in Table 8 were added and heated and dissolved at 75 ° C. After washing, this product imparted a moisturizing feeling to the hair, and was excellent in texture as compared with the product to which the moisturizing agent used in the present invention was not added.

[0035]

[Table 8]

Use Example 5 Hair Brushing Ingredient (A) shown in Table 9 was thoroughly stirred in advance, and then ingredient (B) was added, and the mixture was heated to 70 to 80 ° C. and stirred. After cooling the solution to 50 ° C., the component (C) was added and the mixture was stirred and cooled to room temperature. This product imparted a moisturizing feeling to the hair, gave a firmness and firmness, and was superior in texture to the hair of the present invention to which no moisturizing agent was added.

[0037]

[Table 9]

Use Example 6 Lipstick (A) shown in Table 10 was dissolved by heating at 70 to 80 ° C. and stirred, then (B) was added and kneaded with a roll mill to uniformly disperse. After defoaming, it was poured into a mold and rapidly cooled to solidify. After the solidified product was taken out of the mold and loaded into a container, the appearance of the stick was adjusted and then passed through a flame to make the surface uniform. This product can be easily applied to the lips, has a uniform color, has no bleeding, gives the lips a moist feeling and moisture, and has an appropriate moisturizing effect.

[0039]

[Table 10]

[0040]

EFFECT OF THE INVENTION The moisturizing agent of the present invention is excellent in both moisturizing power and hygroscopic power, and is highly safe. Further, cosmetics and external preparations for skin containing the moisturizer have a good feeling in use when applied, and give a smooth and moisturizing feel to the skin and hair, and have no stickiness, slimyness or tightness.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display area A61K 37/02 8314-4C

Claims (2)

[Claims] 1. A moisturizer containing polyaspartate. 2. A cosmetic or an external preparation for skin containing the moisturizing agent according to claim 1.