JP2003146830A - Cosmetic - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a cosmetic which is obtained by processing a single kind of a polyamino acid, develops both actions of moisture retaining property and elasticity, has a simple component composition and a reasonable cost. SOLUTION: This cosmetic comprises a radiation-crosslinked body of a polyamino acid or a polyamino acid salt. In the cosmetic, especially the polyamino acid is γ-polyglutamic acid and the polyamino acid salt is γ- polyglutamate. Since a great number of bag-like internal spaces are formed in the network structure by radiation crosslinking and a large amount of water can be absorbed and held in the internal spaces, a revolutionary cosmetic which has extremely increased moisture retaining property and can provide the surface of the skin with elasticity can be actualized. Furthermore, since both moisture retaining property and elasticity are provided by radiation crosslinking of a single kind of the polyamino acid, an excellent cosmetic can inexpensively be obtained.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a cosmetic composition containing a radiation-crosslinked product of a polyamino acid or a polyamino acid salt, and more particularly, γ-polyglutamic acid or γ-
The present invention relates to a cosmetic composition containing a radiation cross-linked product of polyglutamate to exert a moisturizing effect and an elastic effect on the skin and hair, thereby exhibiting a beautiful skin effect and a beautiful hair effect.

[0002]

2. Description of the Related Art In general, it is considered important to keep the skin and hair moisturized in order to keep the skin and hair youthful. Originally, in the stratum corneum of the skin, NMF
There is a hygroscopic substance called (Natural Moisturing Factor), and this NMF has a moisturizing effect on the skin. Similarly, the hair has a hair cell membrane complex called CMC (Cell Membrane Complex) between the cuticles to condition the hair. Also,
Sebum as a natural emollient component suppresses evaporation of water from the epidermis and enhances the action of the natural moisturizer.

Therefore, cosmetics such as skin cosmetics and hair cosmetics are designed by using these natural moisturizing mechanisms as models. That is, in cosmetics, a moisturizer that retains moisture in the epidermis and the stratum corneum and an emollient agent that suppresses evaporation of moisture in the stratum corneum play a large role.

As moisturizers that have been used conventionally, natural materials such as glycerin, sorbitol, hyaluronic acid salts and chondroitin sulfate as dermis components, and chemically synthesized substances such as polyethylene glycol and polypropylene glycol of several% to several tens% are used. It was blended in a quantity.

As the emollient agent, oil having a composition similar to that of sebum has been used, and lanolin, squalane, lecithin synthetic ester and the like have been used as oils and fats having water-holding property.

[0006]

However, in recent years, technological developments have been progressing in which amino acids are used as moisturizing ingredients in cosmetics. Amino acids are constituents of proteins that make up the body, and have a very good compatibility with skin and hair and are safe constituents.

[0007] For example, it has become known that when cells of the epidermis die to become the stratum corneum, intracellular proteins are decomposed into amino acids, and this amino acid functions as a moisturizing factor for the stratum corneum. It has also been found that amino acids act as a moisturizing component of hair cuticles.

Therefore, cosmetics containing amino acids have been developed. JP-A-8-217656 discloses a cosmetic containing a saccharide-bonded polyamino acid. JP-A-10-298058 discloses a bath agent containing a polyacidic amino acid. These are aimed at the moisturizing effect of skin, the effect of preventing rough skin, and the effect of smoothing the skin, focusing on the moisturizing property of polyamino acid.

Further, Japanese Patent Laid-Open No. 2001-34217 discloses a skin external preparation containing one or more amino acids and natto extract, and Japanese Patent Laid-Open No. 2000-34219 discloses a skin external preparation containing one or more mucopolysaccharides and natto extract. Is disclosed.
These inventions add the elasticity of natto extract in addition to the moisturizing action of amino acids and mucopolysaccharides.

Natto extract is a liquid obtained by extracting the viscous component of natto with ethanol and is a natural extract containing γ-polyglutamic acid as a main component. Glutamic acid is also a kind of amino acid, but it has a property of giving elasticity to the skin due to its viscosity, and is a very safe cosmetic because it is a natural ingredient.

As described above, in recent cosmetics, both the moisturizing effect and the elasticity effect are introduced into the cosmetic by using the polyamino acid and γ-polyglutamic acid in combination.

[0012] However, since γ-polyglutamic acid is a kind of polyamino acid, conventional cosmetics in which polyamino acid and natto extract are used in combination contain plural kinds of polyamino acids to keep skin and hair moisturizing and elastic. Both effects of sex will be given. It can be understood that different types of polyamino acids have different properties, but compounding a plurality of types of polyamino acids complicates the ingredients of cosmetics and causes a price increase.

[0013] Therefore, the object of the present invention is to provide a cosmetic composition which, by processing a single kind of polyamino acid, exhibits both moisturizing and elastic effects, has a simple component composition and is inexpensive. That is.

[0014]

The invention according to claim 1 is a cosmetic material comprising a radiation-crosslinked product of a polyamino acid or a polyamino acid salt.

In the invention of claim 2, the polyamino acid is γ
-Polyglutamic acid, wherein the polyamino acid salt is γ-
The cosmetic according to claim 1, which is a polyglutamate.

The invention of claim 3 is the cosmetic composition according to claim 2, wherein the γ-polyglutamic acid or γ-polyglutamic acid salt is a product of a γ-polyglutamic acid-producing bacterium.

According to a fourth aspect of the present invention, the radiation cross-linked product of the γ-polyglutamic acid or γ-polyglutamic acid salt is 10
The cosmetic according to claim 2, which has a molecular weight of, 000,000 or more.

The invention of claim 5 is the cosmetic composition according to claim 2, wherein the amount of the radiation-crosslinked product of γ-polyglutamic acid or γ-polyglutamic acid salt is 0.01 to 10% by weight.

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION The inventors of the present invention have earnestly studied to impart elasticity such as natto extract to polyamino acids having moisturizing properties, and as a result, radiation obtained by irradiating polyamino acids or polyamino acid salts with radiation. The present invention has been completed by discovering that the crosslinked body acquires elasticity.

Among the polyamino acids, it was discovered that radiation-crosslinking of γ-polyglutamic acid or γ-polyglutamic acid salt, in particular, drastically increases the moisturizing property as compared with that before crosslinking, and exhibits free elasticity. Then, the basis of the present invention is constructed.

Generally, the structural formula of an amino acid is NH ₂ (CO
OH) -CH-R. Polyamino acids include homopolymers in which the same amino acid is polymerized in a chain and heteropolymers in which a plurality of types of amino acids are polymerized in a chain. Since the hydrogen atom H and the oxygen atom O in the polyamino acid form hydrogen bonds with water, the polyamino acid has a moisturizing property of adsorbing water on the surface. Therefore, the moisturizing properties of polyamino acids having safety are also used as cosmetics.

When the chain-shaped polyamino acid is irradiated with radiation, for example, CH ₂ in the polyamino acid is converted to CH- by a dehydrogenation reaction, and CH- of two polyamino acids are bonded to CH-HC. To form a crosslinked body.
When a large number of polyamino acids are cross-linked by radiation, a network structure is formed, and a large number of bag-shaped spaces are formed therein. Of course, the crosslinking reaction may occur by a route other than the dehydrogenation reaction.

Crosslinking by radiation has the advantage that a polyamino acid radiation crosslinked product can be formed while maintaining the original properties of the amino acid, since the polyamino acid can be crosslinked without heating. The radiation crosslinking reaction is a low temperature crosslinking reaction and is characterized in that it is different from the crosslinking reaction by heating. The polyamino acid undergoes thermal denaturation upon heating, but the radiation crosslinking of the present invention is characterized in that it does not undergo thermal denaturation.

As described above, since the crosslinked polyamino acid radiation product has a large number of bag-shaped spaces inside, it has the ability to absorb and store water molecules in the bag-shaped spaces, and this action makes it possible to retain water larger than polyamino acids. Performance can be expressed. This water retention performance not only further improves the moisture retention performance as a cosmetic material, but also has the characteristic of exhibiting elasticity on the skin and hair surface by retaining water in the bag-shaped space. By radiation-crosslinking the polyamino acid in this manner, it becomes possible to simultaneously have both the moisturizing property and the elasticity.

Next, γ-polyglutamic acid will be described in order to make the above characteristics more concrete. γ- polyglutamic acid (-NH (COOH) CH-CH 2 -CH 2 -
CO-) _n is a chain molecule and the subscript n gives the degree of polymerization. As the starting material, γ-polyglutamic acid having a large molecular weight, particularly one having a molecular weight of several hundreds of thousands to several millions, is suitable, and these molecular weights are determined by the degree of polymerization n.

As the γ-polyglutamic acid according to the present invention, those produced by various production methods are used. Examples of the manufacturing method include a culturing method using a microorganism and a chemical synthesis method. Γ-Polyglutamic acid produced by microorganisms is a natural substance and is recommended from the viewpoint of safety.

In the microorganism culturing method, bacteria such as Bacillus subtilis, Bacillus anthracis, Bacillus megaterium, Bacillus natto and the like belonging to the genus Bacillus can be used, but the F-2-01 strain of Bacillus subtilis is particularly preferable in terms of production amount. Is. This strain produces γ-polyglutamic acid having a molecular weight of several hundreds of thousands to several millions, and its molecular weight is relatively large, so that a crosslinked product can be efficiently produced by radiation.

Γ-Polyglutamic acid produced by microorganisms is a natural product that is harmless to humans and animals and has a great feature that it is biodegradable, as it has been eaten as the main component of the viscous substance of natto since ancient times. That is, this γ-polyglutamic acid is not only simply biodegradable, but has no harm even if accidentally eaten, and is excellent in that it serves as a nutrient. Therefore, even if it is used as a cosmetic, it can be said to be an extremely safe cosmetic material without damaging the skin or hair.

The γ-polyglutamic acid produced by the microorganism is a linear γ-peptide without branching, which is a copolymer of L-glutamic acid and D-glutamic acid, that is, a heteropolymer. This γ-polyglutamic acid having a heteropolymer structure is the most suitable for use in the present invention.

Microorganism-produced γ-polyglutamic acid is obtained by inoculating a microorganism in a liquid medium containing necessary nutrients, culturing at the required temperature for the required time, and isolating γ-polyglutamic acid from the culture solution. A solid medium may be used in addition to the liquid medium. In the present invention, not only γ-polyglutamic acid alone, but also the culture solution itself or a culture containing γ-polyglutamic acid obtained by precipitation from the culture solution may be used.

The chemically synthesized γ-polyglutamic acid produces polymers having various structures such as a homopolymer of L-glutamic acid, a homopolymer of D-glutamic acid, and a mixture of both homopolymers. These chemically synthesized γ-polyglutamic acids can also be used in the present invention.

The γ-polyglutamic acid salt used in the present invention is produced as a salt by the neutralization reaction of γ-polyglutamic acid with a basic compound. It is efficiently produced by dissolving γ-polyglutamic acid and a basic compound in a solvent such as water at room temperature and stirring with heating. Examples of the basic compound include hydroxides of alkali metals and alkaline earth metals, such as sodium hydroxide, potassium hydroxide, magnesium hydroxide, calcium hydroxide, barium hydroxide, etc.
There are organic basic compounds such as ammonia and amine.

Under the reaction conditions of γ-polyglutamic acid and a basic compound, the heating temperature is preferably 5 to 100 ° C.
If the temperature is lower than 5 ° C, the reaction becomes slow, and if the temperature exceeds 100 ° C, water, which is a kind of solvent, may boil and the reaction may become unstable.
The pH is preferably weakly acidic to weakly basic, and particularly preferably 5 to 10. Further, the amounts of γ-polyglutamic acid and the basic compound are appropriately stoichiometric reaction amounts without excess or deficiency.

The γ-polyglutamic acid or γ-polyglutamic acid salt used in the present invention preferably has a molecular weight distributed in the range of several hundreds of thousands to several millions. It is distributed within that range. Even in the case of chemical synthesis, it is suitable to polymerize to several hundreds of thousands or more.

In the present invention, the above-mentioned γ-polyglutamic acid or γ-polyglutamic acid salt is crosslinked by radiation to form a crosslinked product having a molecular weight of 10 million or more.

When this γ-polyglutamic acid is irradiated with radiation, CH ₂ is converted to CH- by a dehydrogenation reaction, and the two straight chains of γ-polyglutamic acid are bonded via CH-HC to give [(-NH ( _{COOH) CH-CH-CH 2} -CO
-) It is believed to crosslink as _n ] ₂ . When this degree of cross-linking is further increased, [(-NH (COOH) CH-
A radiation-crosslinked product having a large molecular weight such as CH—CH ₂ —CO—) _n ] _m is produced. Here, m represents the degree of crosslinking, and gives the number of linear chains of γ-polyglutamic acid that are crosslinked.

By increasing the degree of crosslinking m, γ-
The molecular weight of the crosslinked polyglutamic acid is set to 10 million or more. Since γ-polyglutamic acid is a polypeptide chain, a network structure having a large number of bag-shaped spaces formed therein is formed by the linkage of —CH—HC—.

The present invention is directed to polyamino acids, of which γ-
It was made by discovering that a radiation-crosslinked product of polyglutamic acid has an extremely large water absorption capacity. Its water absorption rate reaches about 1000 times, which is incomparably higher than that of γ-polyglutamic acid before irradiation.
In other words, the increase of the water absorption rate is the increase of the moisturizing performance, and at the same time, the increase of the elastic performance is brought about. It should be reiterated that the water absorption of γ-polyglutamic acid is only hydration at the molecular surface, whereas the water absorption of γ-polyglutamic acid radiation crosslinked product is water absorption into the inner bag-like space due to the network structure. .

If the degree of cross-linking is too high, the bag-like space becomes small, so that the water retaining ability is lowered, and the moisture retaining ability and elasticity are also reduced.
Therefore, by appropriately adjusting the degree of crosslinking, it becomes possible to optimize the moisturizing property and elasticity.

The water-retaining power of the radiation-crosslinked product of γ-polyglutamic acid or γ-polyglutamic acid salt not only retains water but also traps fine particles of a cosmetic material that protects the skin in water, so that Can be protected for a long period of time, and the period of appearance of the cosmetic effect can be extended.

As described above, the present invention is characterized in that radiation is used to crosslink γ-polyglutamic acid. When crosslinking is carried out by a thermochemical reaction, a high temperature is required, so that the γ-polyglutamic acid or γ-polyglutamic acid salt as a raw material is susceptible to thermal modification. When radiation crosslinking is used, crosslinking can be performed at a low temperature, so that crosslinking can be realized without degrading γ-polyglutamic acid.
Therefore, a γ-polyglutamic acid crosslinked product containing no modified product can be obtained by radiation crosslinking.

In particular, γ-polyglutamic acid produced by microorganisms is a kind of polypeptide, and it is difficult to adopt the heat-crosslinking, judging from the weak heat of amino acids. Considering that the viscous substance of natto is γ-polyglutamic acid,
The situation of heat denaturation when natto is heated will be well understood. Therefore, the present invention is characterized in that radiation crosslinking is used to realize low temperature crosslinking.

Γ-Polyglutamic acid or γ-polyglutamate alone is not only irradiated, but also a culture solution or culture obtained by culturing a microorganism is irradiated, and γ-polyglutamic acid or γ-polyglutamic acid is irradiated. A radiation-crosslinked salt can be obtained.

Radiation for crosslinking includes α rays, β rays, γ
Rays, X-rays, electron rays, neutron rays, meson rays, ion rays, etc. can be used. Among these, γ-rays because of good operability,
X-rays and electron beams are suitable. Both X-ray tube and non-tube types of X-rays can be used, and radiant light emitted from an electron ring which has become widespread in recent years can also be used. A known electron beam irradiation apparatus can be used for the electron beam depending on the beam energy.

Gamma rays are excellent in that a radiation source can be used. Cobalt 60 and strontium 9 as γ-ray source
0, zirconium 95, cesium 137, cerium 14
1, ruthenium 177, etc., but cobalt 60 and cesium 137 are preferable from the viewpoint of half-life and energy.

In the present invention, γ-polyglutamic acid or γ
-By radiation-crosslinking polyglutamate,
A γ-polyglutamic acid radiation crosslinked product or a γ-polyglutamate radiation crosslinked product having a molecular weight of 10 million or more is produced. When the molecular weight is cross-linked to 10 million or more, the water absorption performance of the γ-polyglutamic acid cross-linked product is rapidly increased, and the moisturizing performance and elasticity performance of the cosmetic are improved.

To crosslink γ-polyglutamic acid or γ-polyglutamic acid salt to a molecular weight of 10 million or more, γ-
It is necessary to irradiate polyglutamic acid raw material with an absorbed dose of 1 to 500 kGy, and if it is less than 1 kGy, the crosslinking does not proceed easily, and if it exceeds 500 kGy, the crosslinking proceeds too much, so the internal space formed by the network structure of the crosslinked body. Becomes smaller, and conversely the water absorption becomes lower. From the viewpoint of crosslinkability and water absorption, the absorbed dose is 5-10.
0 kGy is more preferred.

Generally, γ-polyglutamic acid salt is soluble in water, but γ-polyglutamic acid is known to be insoluble in water. However, when radiation cross-linking is applied to both γ-polyglutamic acid and γ-polyglutamate, the surface of the radiation cross-linked product has an affinity for water and water-containing organic solvents such as water-containing alcohol and water-containing acetone. It was discovered that

The present invention was also made by paying attention to the property of surface modification of γ-polyglutamic acid and γ-polyglutamate radiation-crosslinked product by radiation crosslinking. That is, both the γ-polyglutamic acid and the γ-polyglutamic acid salt become hydrophilic by becoming a radiation cross-linked product.

This property means that the γ-polyglutamic acid and the γ-polyglutamate radiation crosslinked product are soluble in a large amount of water. However, in the intermediate state until dissolution, it also means that water is absorbed to maintain the gel state or sol state. According to the experiments conducted by the present inventor, it was found that the water absorption rate with respect to pure water kept the gel state up to about 1000 times, and when the amount of pure water was more than that, the state changed to the sol state and gradually changed to the solution. There is. Therefore, the radiation-crosslinked γ-polyglutamic acid and γ-polyglutamic acid salt have the ability to freely adjust the material form of cosmetics by the blending ratio with water.

The radiation-crosslinked γ-polyglutamic acid and γ-polyglutamate have an alcohol-containing ability due to their hydrophilicity. For example, when they are added to an unmodified alcohol aqueous solution of 0 to 50%, they are mixed uniformly. Can be gelled.

The γ-polyglutamic acid and γ-polyglutamate radiation cross-linked product can be mixed with many hydrophilic substances in water. For example, it can be gelled by being uniformly mixed with 0 to 50% of an aqueous solution of glycerin, butanediol, or polyethyleneimine.

Further, the γ-polyglutamic acid and γ-polyglutamate radiation cross-linked product can be mixed with many hydrophobic substances in an aqueous alcohol solution. For example, polypropylene glycol diol type 700 and diol type 3000 can be uniformly mixed with an alcohol-added aqueous solution to form a gel. Liquid paraffin exhibits similar properties.

Therefore, the radiation-crosslinked γ-polyglutamic acid and γ-polyglutamate can be uniformly mixed with other appropriately selected cosmetic materials to form the desired cosmetic. Therefore, for example, as a material for various cosmetics such as skin care products such as emulsions and beauty liquids, hair care products such as hair rinses and hair treatments, and makeup products such as foundations and lipsticks, γ
-Polyglutamic acid and γ-polyglutamate radiation cross-linked products can be used.

The blending amount of γ-polyglutamic acid and γ-polyglutamate radiation crosslinked product is appropriately in the range of 0.01 to 10% by weight, but it is limited to this value because it varies depending on the intended cosmetics. It is not something that will be done.

The above-mentioned properties of the γ-polyglutamic acid and γ-polyglutamate radiation crosslinked products can be similarly applied to the polyamino acid and polyamino acid salt radiation crosslinked product as a cosmetic, which is a superordinate concept.

[0057]

[Example] [Example 1: Production of radiation-crosslinked product of γ-polyglutamic acid] As a γ-polyglutamic acid-producing bacterium,
Bacillus subtilis F-2-01 was selected. The liquid medium was placed in a container of several 100 m ³ for mass production. The medium composition was constructed as follows.

The above strain was inoculated into this liquid medium, and p
The H was adjusted to 7.5 and the above was kept at a constant temperature of 37 ° C. When culturing is continued for 6 days with aeration and stirring, γ-polyglutamic acid and its salts are accumulated in the culture solution. The culture was centrifuged to separate the cells from the culture, and the γ-polyglutamic acids were isolated.

Although the production amount of γ-polyglutamic acid depends on the culture conditions, it is 5 to 50 (g / g) in the culture medium.
L) was reached, and it was proved that industrial mass production of γ-polyglutamic acid was possible. Also,
The molecular weight of γ-polyglutamic acid produced is 500,000 ~
It was found to be distributed over 2 million. Where γ-
The polyglutamic acids are collectively referred to as acids, salts or mixtures thereof.

To this 5% by weight aqueous solution of γ-polyglutamic acids, 20 gGy of gamma rays was applied by a cobalt 60 radiation source.
Irradiation with (2 Mrad) generated a γ-polyglutamic acid radiation crosslinked product. This irradiation causes the aqueous solution to gel and the crosslinked γ-polyglutamic acid has a molecular weight of about 1
It was estimated to be 5 million. Γ-
A powder of radiation-crosslinked polyglutamic acid was obtained. The powder was white. The gel-like substance or the dry powder can be used as the cosmetic raw material of the present invention. This dry powder was used in all subsequent examples.

[Example 2: Gelation of aqueous solution of polypropylene 700] A powder of γ-polyglutamic acid radiation crosslinked product having a radiation dose of 20 kGy was obtained. This powder (PG
1% by weight of A) was added and polypropylene 700 was mixed with pure water to gel polypropylene 700. The results are shown in Table 1.

[0062]

As can be seen from Table 1, when the amount of polypropylene was large, it became difficult to dissolve and a non-uniform gel was formed. However, it was found that when the amount of polypropylene became small, the gel became uniform but became an opaque gel and was not completely dissolved.

[Example 3: Gelation of aqueous alcohol solution of polypropylene 700] Ethyl alcohol was added to the aqueous solution of Example 2 to attempt gelation. Radiation dose is 20
A powder of γ-polyglutamic acid radiation-crosslinked product of kGy was obtained. 1% by weight of this powder (PGA) was added and polypropylene 700 was mixed with pure water and ethyl alcohol to gel polypropylene 700. The results are shown in Table 2.

[0065] <Table 2> Gel containing 1% PGA (unit: parts by weight) <Amount of polyproylene> <Pure water> <Ethyl alcohol> <Gel state>       20 80 50 Transparent uniform gel       30 70 50 Transparent uniform gel       40 60 50 Transparent uniform gel       50 50 50 Transparent uniform gel

As can be seen from Table 2, when 50 parts by weight of ethyl alcohol was added, it was uniformly dissolved regardless of the amount of polypropylene, and a transparent uniform gel was obtained.
Therefore, it was found that the gelation by PGA was greatly improved by adding alcohol.

Example 4 Gelation of Aqueous Solution of Polypropylene 3000 A powder of γ-polyglutamic acid radiation crosslinked product having a radiation dose of 20 kGy was obtained. This powder (PG
1% by weight of A) was added and polypropylene 3000 was mixed with pure water to gel polypropylene 3000. The results are shown in Table 3.

[0068]

As can be seen from Table 3, polypropylene 30
00 did not mix with water regardless of the amount, and even when gelled, only a non-uniform gel was formed. However, some affinity was observed.

Example 5 Gelation of Polypropylene 3000 Aqueous Alcohol Solution Gelation was tried by adding ethyl alcohol to the aqueous solution of Example 4. Radiation dose is 2
A powder of 0 kGy of γ-polyglutamic acid radiation-crosslinked product was obtained. 1% by weight of this powder (PGA) was added and polypropylene 300, pure water and ethyl alcohol were mixed to gel polypropylene 3000. The results are shown in Table 4.

[0071] <Table 4> Gel containing 1% PGA (unit: parts by weight) <Amount of polyproylene> <Pure water> <Ethyl alcohol> <Gel state>       20 80 40 Opaque gel       30 70 40 Opaque gel       40 60 40 Opaque gel       50 50 40 Opaque gel

As can be seen from Table 4, when 40 parts by weight of ethyl alcohol was added, the affinity was observed in the whole regardless of the amount of polypropylene, and an opaque gel was obtained. Although some improvement can be realized by adding alcohol to the aqueous solution, it was also found that a uniform sol can be prepared by further homogenizing this.

Example 6 Gelation of Liquid Paraffin Aqueous Solution A powder of γ-polyglutamic acid radiation crosslinked product having a radiation dose of 20 kGy was obtained. 1 of this powder (PGA)
Liquid paraffin and pure water were mixed in an amount of 1 wt% to gel the liquid paraffin. The results are shown in Table 5.

[0074]

As can be seen from Table 5, the liquid paraffin was not mixed with water and the gel produced by the addition of PGA was also completely separated from the liquid paraffin. Therefore, gelation of liquid paraffin was not possible.

[Example 7: Gelation of alcoholic aqueous solution of liquid paraffin] A radiation-crosslinked powder of γ-polyglutamic acid having a radiation dose of 20 kGy was obtained. This powder (P
GA) was added in an amount of 1% by weight, liquid paraffin, pure water, and 50 parts by weight of ethyl alcohol were mixed to gel the liquid paraffin. The results are shown in Table 6.

[0077] <Table 6> Gel containing 1% PGA (unit: parts by weight) <Flowing paraffin amount> <Pure water> <Ethyl alcohol> <Gelization status>       20 80 50 Heterogeneous gel with affinity       Heterogeneous gel with 30 70 50 affinity       40 60 50 Heterogeneous gel with affinity       Heterogeneous gel with 50 50 50 affinity

As can be seen from Table 6, when ethyl alcohol is added, liquid paraffin and water are heterogeneously mixed and gelled. In other words, it was found that a heterogeneous gel having an affinity for paraffin was completed. Therefore, it was found that more effective gelation can be achieved by performing gelation with PGA in a state where alcohol is added.

As can be seen from the above examples, the radiation-crosslinked product of γ-polyglutamic acid or γ-polyglutamic acid salt according to the present invention is mixed with other cosmetic ingredients in an aqueous solution or an alcohol-added aqueous solution to prepare a cosmetic composition. A uniform gel in which the ingredients are uniformly dispersed and dissolved can be formed. Therefore,
This uniform gel or sol can be used as a cosmetic product, or can be used as an intermediate product to reach a cosmetic product.

The cosmetics according to the present invention are not limited to the above-described embodiments and examples, and various modifications, design changes and the like within the technical scope of the present invention are within the technical scope thereof. It goes without saying that it is included within.

[0081]

According to the invention of claim 1, since a radiation-crosslinked product of polyamino acid or polyamino acid salt is blended as a cosmetic material, it is extremely safe because it is made from a component of our body, and radiation-crosslinked. Since the water absorption capacity is remarkably enhanced by the above, it is possible to provide an epoch-making skin cosmetic and hair cosmetic that exhibit extremely excellent moisturizing properties and elasticity.

According to the second aspect of the present invention, since the radiation-crosslinked product of γ-polyglutamic acid or γ-polyglutamic acid salt is used as a cosmetic material, any radiation-crosslinked product exhibits hydrophilicity, and particularly alcohol is added. In the state, even a hydrophobic substance can be uniformly gelled or sol-ized, so that cosmetics using various cosmetic materials can be manufactured.

According to the invention of claim 3, γ-polyglutamic acid or γ-produced by the γ-polyglutamic acid-producing bacterium.
Since polyglutamate is used, it is possible to manufacture a cosmetic material which is a very safe raw material as a natural material and is extremely safe even if it is accidentally eaten by humans.

According to the invention of claim 4, the molecular weight is 100.
Since the main component is a radiation-crosslinked product of γ-polyglutamic acid or γ-polyglutamic acid salt of at least 0,000, the water retention amount is remarkably increased, and it is possible to produce a cosmetic composition having remarkably enhanced moisturizing properties and elasticity.

According to the invention of claim 5, even if the blending amount of the radiation cross-linked product of γ-polyglutamic acid or γ-polyglutamic acid salt is as small as 0.01 to 10% by weight,
A cosmetic having a stable gel or sol state can be provided.

Claims (5)

[Claims] 1. A cosmetic comprising a radiation-crosslinked product of a polyamino acid or a polyamino acid salt. 2. The cosmetic according to claim 1, wherein the polyamino acid is γ-polyglutamic acid, and the polyamino acid salt is γ-polyglutamic acid salt. 3. The cosmetic according to claim 2, wherein the γ-polyglutamic acid or γ-polyglutamic acid salt is a product of a γ-polyglutamic acid-producing bacterium. 4. The cosmetic according to claim 2, wherein the radiation-crosslinked product of γ-polyglutamic acid or γ-polyglutamic acid salt has a molecular weight of 10 million or more. 5. The compounding amount of the radiation-crosslinked product of γ-polyglutamic acid or γ-polyglutamic acid salt is 0.01 to 1.
The cosmetic according to claim 2, which is 0% by weight.