JP2003012442A - Cosmetic having moisture-retaining property - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cosmetic which is not sticky, when used, has good affinity to skins and hair, has a good moisture-retaining effect, and has a good moist touch. SOLUTION: This cosmetic is characterized by containing a poly-γ-glutamic acid cross linked product having a gel rate of 20 to 100% as a moisturizing agent. The cosmetic is widely used in a cosmetic field such as skin cosmetics, hair cosmetics and makeup cosmetics and in a toiletry field such as a bath article.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to cosmetics such as skin cosmetics, hair cosmetics and makeup cosmetics, and cosmetics used in the field of toiletries such as bath salts, and more particularly to cosmetics having excellent moisturizing properties.

[0002]

BACKGROUND OF THE INVENTION Skin cosmetics such as lotions, emulsions, creams and packs, hair cosmetics such as shampoos, rinses, hair creams and hair sets, makeup cosmetics such as foundations, lipsticks and eye shadows and bath agents. Etc. need a moisturizing effect. Lotion, makeup cream,
It is widely practiced to add a moisturizer to the skin and hair of hair creams, hair rinses, bath agents and the like. Also,
Various moisturizers are used for skin and hair cosmetics such as skin lotions, creams, hair shampoos, rinses, etc. in order to give a moist feeling while suppressing the feeling of dryness and dryness while retaining water. Has been.

There are a great variety of substances having a high hygroscopic ability, including organic substances and inorganic substances, but the moisture retaining agent actually used is required because of its safety and low influence on the morphological stability of the product. The types of agents are limited. Furthermore, the properties that the moisturizer should have are required to have the ability to absorb water and at the same time prevent evaporation of water. Moisturizers commonly used are often used in combination to achieve these properties. However, since a substance having a high hygroscopic property such as sodium lactate is an electrolyte, it has an unfavorable property in terms of product formulation such as an emulsification-inhibiting action, and the amount used and the application are limited. On the other hand, polyols such as glycerin, sorbitol, and propylene glycol have relatively good moisturizing properties, but stickiness tends to occur in the product, and when used in cosmetics and the like, there is a difficulty in feeling when used. Method of blending polyaspartic acid or amino acid ester with cosmetics (Japanese Patent Laid-Open No. 61-33107, Japanese Patent Laid-Open No. 10-33107)
No. 251402) has a moisturizing effect, but the moist feeling cannot be said to be sufficient, and it has a greasy feeling.

[0004]

SUMMARY OF THE INVENTION Under the circumstances described above, the object of the present invention is to provide a cosmetic which is not sticky during use, has a good moisturizing effect on skin and hair, and has a moisturizing effect. To provide.

[0005]

The inventors of the present invention have conducted extensive studies to achieve the above objects, and as a result, have found that the gelation rate is 2
It was found that by adding a small amount of 0 to 100% poly-γ-glutamic acid cross-linked product as a moisturizer, a cosmetic having good moisturizing effect can be obtained without stickiness during use,
The present invention has been reached. That is, the present invention provides the following cosmetics. [1] Poly-γ having a gelation rate of 20 to 100% as a moisturizing agent
-A cosmetic characterized by containing 0.001 to 5 mass% of a glutamic acid crosslinked product. [2] The crosslinked poly-γ-glutamic acid is produced by radiation-crosslinking a solution of poly-γ-glutamic acid dissolved in at least one solvent selected from water, methyl alcohol and ethyl alcohol. [1] Cosmetics. [3] The cosmetic of [2], wherein the radiation is an electron beam.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION The poly-γ-glutamic acid used as the raw material of the moisturizing agent in the present invention is not particularly limited, and various production methods can be used. For example,
There are a culturing method using a microorganism, that is, a culturing method using Bacillus subtilis, a culturing method using a genetically modified microorganism, a method of preparing from natto, and a chemical synthesis method. When poly-γ-glutamic acid is produced by a culture method using a microorganism, poly-γ-
Any strain can be used as long as it is a strain that produces glutamic acid outside the cells, but Bacillus species is particularly preferable. Specific examples include Bacillus subtilis, Bacillus
Anthracis, Bacillus natto, etc. are used.
Particularly, those produced by microorganisms such as Bacillus subtilis and having a molecular weight of several million or more are preferable (JP-A-1-174397).

In the method for culturing microorganisms, any strain, medium, etc. may be used so long as it can produce poly-γ-glutamic acid. For example, as the medium, either a synthetic medium or a natural medium can be used as long as it appropriately contains a carbon source, a nitrogen source, an inorganic substance and other nutrients. As the added amino acid, L-glutamic acid, aspartic acid, alanine, leucine, phenylalanine, histidine, or the like, or a salt thereof can be used, and preferably L-glutamic acid is 2 to 12%, preferably 3 to 10%. is there.

As carbon sources, glucose and sucrose
Sodium, citric acid or xylose can be used, but citric acid or glucose is preferable. As the nitrogen source, organic nutrient sources such as peptone or yeast extract and inorganic nutrient sources such as ammonium sulfate can be used. The culture is performed under aerobic conditions such as shaking culture or stirring culture, and the culture temperature is 25 to 45 ° C, preferably 30 to 40 ° C. The pH during culturing is 5 to 9, preferably 6 to 8, and the pH during culturing is adjusted with sodium hydroxide, potassium hydroxide or the like.

The culture time is usually 48 to 72 hours and poly-γ
-Glutamic acid accumulates outside the cells. The poly-γ-glutamic acid in the culture medium after the completion of the culture can be recovered by a method that has been conventionally performed. That is, cells are removed by centrifugation, a filter aid or a filter having fine pores, and ultrafiltration is performed to remove poly-γ.
-Glutamic acid can be recovered. Also, 3-4
Poly-γ-glutamic acid is precipitated by adding a double amount of ethanol or the like. Dissolve the precipitate in water to remove insolubles, remove low molecular weight substances by dialysis or ultrafiltration,
Poly-γ-glutamic acid can be recovered by repeating reprecipitation with ethanol or the like.

The poly-γ-glutamic acid cross-linked product used in the moisturizing agent of the present invention is a poly-γ-glutamic acid obtained by culturing the microorganism as described above or a chemical synthesis method in a solvent. Of 2 to 20% by mass, preferably 5 to 15% by mass, the solution is irradiated with radiation, and the resulting crosslinked product is separated and purified. Water, alcohol as a solvent,
Acetone, methyl acetate, ethyl acetate, etc. are used,
Water, methyl alcohol and ethyl alcohol are preferred, with water being especially preferred.

As the solution in which poly-γ-glutamic acid is dissolved, a radiation permeable container such as a glass vial is used. The radiation is not particularly limited, and examples thereof include α-ray, β-ray, γ-ray, electron beam, neutron beam, X-ray, and the like, and the electron beam is preferable. The irradiation dose of the electron beam to be irradiated is somewhat different depending on the conditions such as the water absorption rate to be obtained, but usually the irradiation dose is preferably 20 kGy or more. If the irradiation time is less than 1 second, the crosslinked product may not be sufficiently formed, so it is preferable to perform the irradiation for at least 1 second or longer.

By such a method using electron beam irradiation, a poly-γ-glutamic acid crosslinked product having a desired gelation rate can be obtained. The gelation rate of the crosslinked poly-γ-glutamic acid used in the moisturizer of the present invention is 20 to 100%, preferably 40 to 100%, more preferably 60 to 100%.
Is. If the gelation rate is lower than 20%, the moisture retention is insufficient and the productivity is also reduced. The gelation rate used in the present invention is a numerical value obtained by dividing the dry mass of a moisturizing agent consisting of a crosslinked poly-γ-glutamic acid by the amount of poly-γ-glutamic acid used for electron beam irradiation, that is, the charged poly. −γ−
It means the percentage of the dry mass of the moisturizing agent consisting of the crosslinked poly-γ-glutamic acid relative to the amount of glutamic acid.

Thereafter, by removing water, a solid poly-γ-glutamic acid crosslinked product can be obtained. This poly-γ-glutamic acid crosslinked product is colorless and transparent, has excellent water absorption, and has biodegradability. The poly-γ-glutamic acid cross-linked product obtained by the above method may be granulated into a predetermined shape, and may be in an irregular crushed state,
It may be spherical or the like.

The poly-γ-glutamic acid cross-linked product used in the moisturizer of the present invention is a lotion, emulsion, cold cream, hand cream, lipstick, eye shadow, hair spray, hairnic, hair fixative, shampoo, rinse,
Widely used in perm solution, sweat remover, bath salts, etc. The amount of the poly-γ-glutamic acid crosslinked product added is usually 0.001.
˜5% by mass, preferably 0.05 to 2.5% by mass. If the addition amount is less than 0.001% by mass, the moisturizing effect is not sufficient, and if it is more than 5% by mass, a sticky feeling is likely to occur, which is not preferable.

The poly-γ-glutamic acid cross-linked product used as a moisturizing agent in the present invention does not lose its effect even if other moisturizing agents such as propylene glycol, sorbidol, aminic acid and sodium lactate are used in combination. . The poly-γ-glutamic acid cross-linked product used in the moisturizer of the present invention is an alkali metal salt such as sodium, potassium and lithium, an ammonium salt, an ethanolamine salt, a diethanolamine salt, a triethanolamine salt and a basic amine salt. Is also included.

[0016]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited thereto.

Production Example 1 A 10% by mass aqueous solution of Meiji γ-PGA (poly-γ-glutamic acid manufactured by Meiji Seika Co., Ltd.) was placed in a glass tray,
Irradiation distance 10cm, 2.5kGy / 1sec irradiation amount 30 with Cockcroft Walton type electron beam irradiation device
Irradiation was performed for a total of 12 seconds so as to give kGY, and the obtained treated product was immersed in water at 4 ° C. for 1 week to remove uncrosslinked poly-γ-glutamic acid. Poly-γ-swelled by absorbing water
The glutamic acid gel was filtered through a wire mesh of 80 mesh and then freeze-dried to obtain a poly-γ-glutamic acid crosslinked product having a gelation rate of 91%. The gelation rate is the ratio of the dry mass of the obtained poly-γ-glutamic acid gel to the mass of the charged poly-γ-glutamic acid.

Examples 1-2, Comparative Examples 1-2 Poly-γ-glutamic acid cross-linked product obtained in Production Example 1,
Water, ethyl alcohol and a fragrance were mixed in a predetermined mass ratio shown in Table 1 to produce a skin cosmetic agent. After applying the skin cosmetic agent to the skin and drying, the moist feeling and the refreshing feeling were evaluated according to the following evaluation criteria. The results are shown in Table 1. A: Moisturized and non-greasy. B: Moisturized and sticky. C: No moist feeling or stickiness.

Comparative Example 3 Meiji γ-PG was used instead of the poly-γ-glutamic acid crosslinked product.
A was carried out in the same manner as in Example 1. The results are shown in Table 1.

[0020]

[Table 1]

[0021]

As is apparent from the above examples, by using the crosslinked poly-γ-glutamic acid according to the present invention as a moisturizer, a cosmetic having a moist feeling and non-greasiness can be easily obtained. be able to. The cross-linked poly-γ-glutamic acid used in the moisturizer of the present invention has an excellent moisturizing effect when added in a small amount to cosmetics, is well adapted to the skin and hair, and is biodegradable, so that it can be used in cosmetics. water,
Emulsion, cold cream, hand cream, lipstick, eye shadow, hair spray, hair tonic, hair dressing,
Widely used in shampoo, conditioner, perm solution, sweat remover, bath salts, etc.

Claims (3)

[Claims] 1. A crosslinked poly-γ-glutamic acid having a gelation rate of 20 to 100% is used as a moisturizing agent in an amount of 0.001 to 5% by mass.
Cosmetics characterized by containing. 2. The poly-γ-glutamic acid crosslinked product is water,
The cosmetic according to claim 1, which is produced by radiation-crosslinking a solution in which poly-γ-glutamic acid is dissolved in at least one solvent selected from methyl alcohol and ethyl alcohol. 3. The cosmetic according to claim 2, wherein the radiation is an electron beam.