JPH08175930A - Soluble keratin and cosmetic - Google Patents

Abstract

PURPOSE: To obtain a cosmetic containing a soluble keratin capable of providing moist feeling, gloss, smoothness, coherency, stiffness to hair and skin. CONSTITUTION: This soluble keratin is obtained by subjecting a keratin protein fiber having a cross-linked structure to reduction treatment in a liquid, removing an insoluble matter, adding an amphoteric surfactant to the resultant solution and removing a reducing agent or by previously bringing a keratin protein fiber having a cross-linked structure into contact with a liquid containing a reducing agent and an amphoteric surfactant and removing the reducing agent from the solution after removal of the insoluble matter.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high molecular weight soluble keratin protein having a free cysteine residue, a method for producing the same, and a skin or hair cosmetic containing the soluble keratin protein.

[0002]

2. Description of the Related Art Conventionally, attempts have been made to utilize keratin proteins present in hair, nails, animal hair, feathers, and horn tissues as a raw material for cosmetics.

The keratin protein in the tissue has a cysteine residue in the molecule which is disulfide-bonded with a cysteine residue of another keratin protein molecule, and is present in a fibrous form and insolubilized. In order to solubilize the keratin on the fiber, a method of cleaving the disulfide bond of keratin in the presence of a reducing agent has long been known.

However, when this reducing agent is removed, the cleaved disulfide bond is bonded again and becomes insoluble.
It was not possible to obtain solubilized keratin even after removing the reducing agent.

In general, the material of cosmetics needs to be water-soluble, and in order to make this fibrous keratin protein soluble in water even in the absence of a reducing agent, the following methods have been reported to date. Has been done.

[0006] As an example thereof, there is a method of lowering the molecular weight of keratin protein using an enzyme or the like. Further, a method for producing a keratin derivative which is soluble even after the disulfide bond in the keratin protein is cleaved with a reducing agent and the cysteine residue is chemically modified with monoiodoacetic acid or the like to remove the reducing agent. There is also.

However, the low-molecular-weight keratin protein has a problem that it has a low conditioning effect to give the hair firmness and elasticity and a low setting effect because of its small molecular weight.

Further, the keratin derivative in which the cysteine residue is chemically modified has a high molecular weight, but the disulfide bond characteristic of keratin is irreversibly modified.
There is a problem that exchange reaction with thiol group / disulfide bond in the hair and formation of cross-linking between keratin molecules on the hair cannot be expected, and the hair is easily separated from the hair.

Therefore, in recent years, in order to solve these problems, a reduced keratin protein is extracted from a keratin-containing substance by using a urea solution containing a reducing agent, and an anionic surfactant is added to the extracted solution. A method for obtaining a stable soluble keratin protein after removing the reducing agent has been proposed (Japanese Patent Laid-Open No. 63-301809).

In the above publication, the soluble keratin protein is shampoo, rinse, treatment, hair cream, set lotion, hair spray, hair liquid,
Although there is a description that it is added to a permanent wave intermediate treatment agent, etc., the obtained soluble keratin protein has an anionic surfactant having strong protein denaturing power, strong detergency, and poor sensory properties when left on hair. Since they coexist, there is a drawback that only cosmetics such as shampoo and face wash can withstand actual use.

[0011]

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a cosmetic composition containing soluble keratin, which has excellent organoleptic properties when left on hair or skin and is highly safe. .

[0012]

[Means for Solving the Problems] In order to achieve the above-mentioned object, claim 1 of the present invention provides a keratin protein fiber having a cross-linked structure, which is subjected to reduction treatment in a liquid, and then insoluble matter is removed,
When removing the reducing agent to obtain soluble keratin,
Soluble keratin obtained by adding an amphoteric surfactant during the reduction treatment or after removing the insoluble matter.

A second aspect of the present invention is a cosmetic containing the soluble keratin according to the first aspect.

The structure of the present invention will be described in detail below. As the keratin-containing substance used in the present invention, hair and nails of humans, sheep, goats, horses, pigs, cows, rabbits and the like and feathers of various birds are preferably used, but wool is preferable from the economical viewpoint.

The reducing agent may be a general reducing agent such as thioglycolic acid, mercaptoethanol or sodium bisulfite. The concentration of these reducing agents is
It is used in an amount of 0.05 to 0.5 mol per 10 g of keratin-containing substance. As the solvent used for the reduction treatment of the keratin-containing substance, water or a buffer solution is used because it is easy to use. The amount is such that the ratio of the keratin-containing substance to the solvent is 0.5.
About 10% by weight is preferable in operation.

Hair, nails, animal hair, feathers, horns, hoofs, etc. may not have sufficient solubility in a liquid medium due to hydrogen bonding even if the disulfide bond is cleaved. In such a case, the solubility of the reduced product was imparted to the liquid medium by adding a protein denaturing agent such as urea or thiourea, an alkali such as sodium hydroxide or ammonia, or an inorganic salt such as sodium chloride as a dissolution aid. It is better to use a solution. Such a solubilizing agent is more effective as the dose is larger, but an appropriate amount is determined in consideration of the solubility in a liquid medium and the efficiency of the subsequent removal operation of the reducing agent and the like.

The reductive solubilization reaction can give good results even if it is neutral, but it is preferably under alkaline conditions, more preferably under alkaline conditions.
It is preferable to carry out at pH 10-11. Further, the reaction temperature and the reaction time are appropriately combined so that the reduction reaction is completed. For example, it is sufficient to carry out the reaction at room temperature for 3 to 6 hours, at 5 ° C for 24 to 48 hours, and at 40 to 60 ° C for 30 to 120 minutes.

The obtained keratin solution contains a reducing agent, a solubilizing agent and the like and needs to be removed. However, before the removal treatment, the insoluble matter existing in the solution is centrifuged in advance. It must be removed by filtration or filtration.

As the amphoteric surfactant added to the keratin solution after removing the insoluble matter, alkyldiaminoethylglycine hydrochloride, 2-alkyl-N-carboxymethyl-N-hydroxyethylimidazolinium betaine, alkyldimethylaminoacetic acid betaine, Alkylamido dimethylamino acetic acid betaine, etc. are used. The amount of the amphoteric surfactant added is 0.1 to 1 in the solution in order to obtain the effect of solubilization.
It is preferably 0% by weight, more preferably 0.3 to 5% by weight, particularly preferably 0.5 to 2% by weight. The addition amount varies depending on the concentration of the keratin solution and the kind of the raw material keratin, but if it exceeds 10% by weight, it tends to be economically unfavorable. The amphoteric surfactant may be added in advance when the reducing agent is first added.

The reducing agent is removed by means of dialysis, gel filtration, membrane filtration, electrodialysis and the like. By this removal, the keratin solution can be obtained as a liquid having no turbidity or insoluble matter.

The resulting keratin solution can be concentrated by a membrane or dried, and further dried to obtain a dry powder. The keratin thus obtained has a very high water solubility. Further, it is a high molecular weight keratin containing 0.5 to 5 cysteines and 0.5 to 5 cystines per 100 amino acid residues in the keratin protein and having a molecular weight of 40,000 to 70,000.
Furthermore, the storage stability of this product was very high, and no insoluble matter was generated in the solution state for at least half a year.

By drying this keratin solution on a petri dish, a transparent film having appropriate strength can be prepared.

Such a keratin solution or powdered keratin can be incorporated into hair cosmetics such as shampoos, rinses, treatments and setting agents, and when human hair is treated with these hair cosmetics, a moist feeling, It can provide luster, smoothness, moderate curl holding power, firmness and elasticity.

Furthermore, when the cosmetics such as lotions, creams and milks containing the keratin solution or powdered keratin are applied to human skin, moisturizing feeling, luster, smoothness and firmness can be imparted.

The amount of the product of the present invention to be added to the cosmetic composition is within a range capable of imparting the above-mentioned effects of keratin, and the final keratin content is preferably 0.01 to 10% by weight, more preferably 0. It is 1 to 2.0% by weight.

[0026]

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

Example 1 20 g of wool (hybrid) was immersed in an 8 M urea aqueous solution (600 ml) containing 3% β-mercaptoethanol and 1 mM EDTA, and the pH was adjusted to 10.5 with 10% potassium hydroxide. Then, after degassing operation, it was sealed. After stirring at room temperature for 3 hours to carry out reduction, the pH was returned to neutral with 6N HCl, and centrifugation was carried out at 12,000 rpm and 4 ° C. for 30 minutes to obtain 740 ml of supernatant. To this solution was added amphoteric surfactant lauric acid amidopropyl betaine (Ampholex LB2, 30% by weight purity) to a final concentration of 3% by weight, and after homogenization, the reducing agent was removed. Using a dialysis membrane, dialysis operation was performed 3 times for 3 hours against 10 liters of ion-exchanged water. As a result, it was possible to obtain a transparent keratin solution containing no insoluble matter. The recovery rate of solubilized keratin protein from 20 g of wool is 76.
It was 5% by weight. The keratin concentration is 30.0 mg / ml (3
% Aqueous solution). Also, when the molecular weight was measured,
It was 40,000 to 70,000 when treated in the absence of a reducing agent. The molecular weight was measured by sodium dodecyl sulfate-polyacrylamide gel-electrophoresis (SDS-).
PAGE). Hereinafter, the molecular weight is measured by this method.

Comparative Example 1 A keratin solution was obtained in the same manner as in Example 1 except that sodium dodecyl sulfate (manufactured by Hanai Co., Ltd.) was used as the anionic surfactant instead of the amphoteric surfactant. As a result, the recovery rate of solubilized keratin protein was 70% by weight.
The molecular weight was 40,000 to 70,000.

Comparative Example 2 An attempt was made to obtain a keratin solution in the same manner as in Example 1 except that ion-exchanged water was used instead of the amphoteric surfactant. However, the transparent liquid as in Example 1 was not obtained, and most of the keratin was obtained as insolubilized liquid. As a result, the recovery rate of solubilized keratin protein was 0%.
Met.

Comparative Example 3 Instead of an amphoteric surfactant, polyoxyethylene (20) sorbitan monolaurate (Wa) was used as a nonionic surfactant.
An attempt was made to obtain a keratin solution in the same manner as in Example 1 except that the product manufactured by Ko was used. However, the transparent liquid as in Example 1 was not obtained, and most of the keratin was obtained as insolubilized liquid. As a result, the recovery rate of solubilized keratin protein was 0%.

Example 2 Example 1 except that the amphoteric surfactant is used from the first step.
A keratin solution was obtained in the same manner as in. As a result, the recovery rate of solubilized keratin protein was 70% by weight. The keratin concentration was 30.0 mg / ml (3% aqueous solution). The molecular weight was 40,000 to 70,000.

Test Example 1 Solubilized keratin solution obtained in Example 1 and Comparative Example 1
Human hair (2 g) was immersed in each of them (3% by weight) at room temperature for 5 minutes, and then washed in running water for 1 minute. The treated hair was dried with a dryer. After that, sensory evaluation was performed. The results are shown in Table 1.

[0033]

[Table 1]

As shown in Table 1, the hair treated with the solubilized keratin obtained in Example 1 gave good sensory evaluation.

Example 3 (Shampoo) The composition shown in Table 2 was prepared and used by 10 female panelists aged 20 to 27 to evaluate the feeling during and after shampooing.

[0036]

[Table 2]

The shampoo containing the product of the present invention was evaluated to have excellent squeakiness at the time of rinsing, smooth combing after drying, and excellent settability in all compositions. I got the result. No irritation to the skin was felt during and after use.

Example 4 (Rinse) The composition shown in Table 3 was prepared and used by 10 female panelists aged 20 to 27 to evaluate the condition of hair after rinsing.

[0039]

[Table 3]

The rinses containing the products of the present invention were smooth in combing after the dry finish in all the compositions, and imparted luster to the hair and were moisturized. In addition, it was evaluated as having excellent sustainability of setting property. In addition,
No irritation to the skin was felt during and after use.

Example 5 (Setting agent) The composition shown in Table 4 was prepared and used by 10 female panelists aged 20 to 27 to evaluate the condition of the hair after using the setting agent.

[0042]

[Table 4]

The setting agent containing the product of the present invention was smooth in combing after the dry finish in all the compositions, and imparted gloss to the hair and was moisturized. Furthermore, it was excellent in sustainability of setting. No irritation to the skin was felt during and after use.

Example 6 (Perm Agent) A perm intermediate treatment agent composition shown in Table 5 was prepared and used by 10 female panelists aged 20 to 27 who were treated with the first agent of perm. The hair condition was evaluated.

[0045]

[Table 5]

The perming agent containing the product of the present invention was smooth in combing after the dry finish in any of the compositions, and imparted gloss to the hair and was moisturized. In addition, the permanence of the style was excellent and the damage was minimal. No irritation to the skin was felt during and after use.

Example 7 (Lotion) A composition shown in Table 6 was prepared and used by 10 female panelists aged 20 to 27 to evaluate the skin condition after the use of the lotion.

[0048]

[Table 6]

The lotions containing the products of the present invention were moisturized, glossy, and
It was evaluated as having smoothness and firmness. No irritation to the skin was felt during and after use.

[0050]

Industrial Applicability As described above, the present invention can provide a cosmetic composition containing soluble keratin protein, which has excellent sensory properties when left on hair or skin and is highly safe.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI technical display location C07K 14/46 8318-4H

Claims (2)

[Claims] 1. When a keratin protein fiber having a crosslinked structure is subjected to reduction treatment in a liquid, insoluble matter is removed, and then a reducing agent is removed to obtain soluble keratin, an amphoteric surfactant is added during reduction treatment or insolubilization. Soluble keratin obtained by adding after removing the thing. 2. A cosmetic containing the soluble keratin according to claim 1.