JP7169622B2 - hair treatment method - Google Patents

Description

The present invention relates to a hair treatment method capable of simultaneously dyeing hair and repairing hair damage. More specifically, the present invention relates to a hair treatment method that provides high hair dyeability and levelness, excellent color durability, and repairs hair damage.

In recent years, the frequency of use of oxidative hair dyes has been increasing for the purpose of changing the nuances of hair color in order to enjoy fashion and to make gray hair less noticeable. Oxidative hair dyes are known to cause hair damage because they contain alkaline agents and oxidizing agents. Specifically, the oxidative hair dye cleaves the disulfide bond (-S-S-) of the keratin protein that forms the hair and oxidizes it to cysteic acid (-SO ₃ ^- ), thereby increasing hair strength and elongation. rate is known to decline. Furthermore, oxidative hair dyes sometimes contain dye intermediates such as paraphenylenediamine, and these dye intermediates are thought to have the potential to cause serious allergies, which is a problem. ing.

Hair dyes such as hair manicures using acid dyes (hereinafter referred to as "acidic hair dyes") have been marketed as hair dyeing means in place of oxidative hair dyes. Acidic hair dyes are said to have high hair-dyeing properties and cause relatively little hair damage. In addition, the potential for allergies is said to be low compared to oxidative hair dyes.

However, acidic hair dyes tend to stain the skin and scalp, and once dyed, they are very difficult to remove. A high level of skill is required to apply the acid hair dye to the base of the hairline without adhering it to the skin or scalp, and not all hairdressers can do it.

In addition, hair dyes such as color treatments using basic dyes (hereinafter referred to as "basic hair dyes") are on the market as alternatives to oxidative hair dyes. Basic hair dyes are relatively weak in dyeing to the skin, and hair dyes that can be used even with bare hands are on the market depending on the formulation, and are excellent in convenience.

However, basic hair dyes have weak dyeing properties on hair, and have problems with regard to hair dyeing properties and color durability. Further, the basic dye is a cationic substance and easily adsorbs to cysteic acid ₍ ^{--SO.sub.3.sup.-} ) generated by hair damage caused by chemical treatments such as oxidation hair dyes and permanent waving agents through ionic bonds. When hair with hair damage as described above is dyed with a basic hair dye, there is a possibility that the levelness of dyeing may be poor.

As a method for solving these problems, a hair dyeing method using a three-component hair dye has been proposed. Thereby, it is possible to provide a hair dyeing method which is excellent in hair dyeing property and color durability, and which causes less dyeing to the skin (Patent Document 1).

In addition, a cosmetic containing a conversion protein has been proposed as a cosmetic for improving properties of damaged hair. As a result, damaged parts of the hair can be repaired and the properties of the hair can be improved (Patent Document 2).

When analyzing the physical properties of hair, it is common to measure strength and extensibility and make a comprehensive judgment. By measuring the extensibility, the "suppleness" and "elasticity" of the hair can be determined. Healthy hair has a strength of about 1N and an elongation rate of about 50% (Non-Patent Document 1).

JP 2012-171952 A JP 2017-124983 A

Teruo Furuya, "Study on Tensile Strength and Extension Rate of Hair", Bulletin of Taisei Gakuin University Vol.9 (2007) p.151-156

When the hair is treated with the hair dyeing method of Patent Document 1, the hair may be damaged due to oxidation-reduction reaction. Furthermore, it may be difficult to uniformly dye hair that is electrically non-uniform due to damage by the hair dyeing method.

Patent Document 2 describes a method for improving properties of hair, but does not describe a method for dyeing hair at the same time as the method.

In order for hair salons and the like to make a profit, shortening the treatment time is one of the major challenges. Also, from the consumer's point of view, it is preferable for a treatment that provides a plurality of great effects in a short period of time, because the restraint time is short and it is easier for the consumer to feel a sense of satisfaction. On the other hand, the method of separately applying the treatment for improving the characteristics of the hair and the treatment for dyeing the hair with an oxidative hair dye or a hair dye requires a long time.

Accordingly, the present invention relates to a hair treatment method capable of performing hair dyeing and hair damage repair at the same time, which provides high hair dyeing and leveling properties, excellent color durability, and repairs hair damage. An object of the present invention is to provide a hair treatment method capable of

The hair treatment method of the present invention comprises (I) a thiol compound in which some or all of the disulfide bonds (-SS-) in keratin are selected from the group consisting of cysteamine, cysteine, and thioglycolic acid; A step of treating the hair with a composition (hereinafter referred to as "composition (I)") containing a keratin derivative or keratin hydrolyzate (hereinafter referred to as "converted keratin") converted with at least one of them ( hereinafter referred to as "step (I)"); and (II) a step of treating the hair with a composition containing one or more basic dyes (hereinafter referred to as "composition (II)") (hereinafter referred to as referred to as “step (II)”).

In the present invention, if necessary, (III) a step of treating the hair with a composition containing one or more reducing agents (hereinafter referred to as "composition (III)") (hereinafter referred to as "step (III) and (IV) a step of treating the hair with a composition containing one or more oxidizing agents (hereinafter referred to as "composition (IV)") (hereinafter referred to as "step (IV)". ) may be included.

Since the hair treatment method of the present invention treats with converted keratin, it is possible to restore the properties of damaged hair to a healthy state. In addition, since the hair is treated with a basic dye, the hair can be dyed. Furthermore, since the above two hair treatments are performed as one treatment in a hair salon or the like, it is possible to provide a treatment for repairing hair damage and dyeing hair in a short period of time.

The keratin is not limited in its origin and structure as long as it has a disulfide bond. Examples include keratin-containing human and bird and animal hair (human hair, wool, feathers, etc.), horns, and nails.

In the converted keratin, some or all of the disulfide bonds in the keratin are cysteamine, cysteine, and at least one of sulfite and thiol compounds selected from the group consisting of cysteamine, cysteine, and thioglycolic acid (hereinafter referred to as "thiol compounds, etc." ) is converted by Hair damage can be repaired by using converted keratin. By repairing hair damage, it is also possible to impart the original properties of hair.

Said transformation means that the disulfide bond in said keratin is cleaved and then a new bond is formed between the S atom at the cleaved point and the S atom in said thiol compound or the like. As described above, in the present invention, part of the disulfide bonds in the keratin may be converted with the thiol compound or the like. Therefore, the converted keratin may contain unconverted disulfide bonds or may contain thiol groups (--SH) formed by cleavage of disulfide bonds. The converted keratin may be used singly or in combination of two or more.

Furthermore, it is preferred that some or all of the disulfide bonds in the keratin are converted to aminoethyl disulfide groups (-S-S-CH ₂ -CHR-NH ₂ ) in terms of adhesion to hair. . As a result, it is particularly excellent in adhesiveness to the areas where hair damage has occurred. As a result, the hair damage can be efficiently repaired, the properties of the hair can be brought to a healthy state, and the hair dyeing property and leveling property of the basic hair dye can be improved. Color persistence can be improved. A part of the disulfide bond may be converted to an aminoethyl disulfide group. Therefore, in the converted keratin in which some or all of the disulfide bonds are converted to aminoethyl disulfide groups, unconverted disulfide bonds may remain, or thiol groups formed by cleavage of disulfide bonds may be may contain.

A specific method for converting the disulfide bond into an aminoethyl disulfide group is not particularly limited. The conversion is usually carried out by reacting the disulfide bond in the keratin with aminoethanethiols (H ₂ N--CHR--CH ₂ --SH). The conversion to the aminoethyl disulfide group may be carried out by directly reacting the disulfide bond with an aminoethanethiol, or the disulfide bond is reduced to a thiol group with a reducing agent, and then the thiol group and It may be carried out by reacting with aminoethanethiols. In this case, the reducing agent is not particularly limited. As the reducing agent, known reducing agents such as mercaptoalkylcarboxylic acids such as thioglycolic acid or salts thereof and salts thereof can be used.

Depending on the amount of the aminoethanethiols and other reaction conditions, one of the disulfide bonds is converted by the aminoethanethiols and the other is converted to a thiol group (the following formula (1)), or both It may be converted by aminoethanethiols (the following formula (2)). Conversion in the present invention includes both of these. In the following formulas (1) and (2), "Cys" means a cysteine residue contained in converted keratin.

Cys-SS-Csy + H ₂ N-CHR-CH ₂ -SH
→ Cys-SS-CH ₂ -CHR-NH ₂ + Cys-SH (1)
Cys-SS-Csy+2H2N-CHR- _{CH2 -} SH
→ 2Csy-SS-CH ₂ -CHR-NH ₂ (2)

In said aminoethyl disulfide group and said aminoethanethiols, "R" in the formula is H, COOH, OH, _NH2 or _CH3 . Preferably, R is H or COOH in terms of solubility. Also, the aminoethanethiols may be salts of H ₂ N--CHR--CH ₂ --SH.

The converted keratin may be subjected to other treatments as desired. For example, the converted keratin may be subjected to enzymatic, acid or alkaline hydrolysis to reduce molecular weight and size. Further, after obtaining converted keratin, other components or insoluble matter may be removed by performing purification, filtration, centrifugation, or the like.

The amount of converted keratin in composition (I) is not particularly limited as long as it is an effective amount. The blending amount of the converted keratin is usually preferably 0.01 to 10% by mass.

Composition (I) may optionally contain other ingredients than converted keratin as long as they do not inhibit the action of the present invention. Examples of the other ingredients include known ingredients conventionally added to cosmetics and other functional ingredients. Specific examples of other components include fats and oils, hydrocarbon oils, higher fatty acids, higher alcohols, ester oils, silicone oils, surfactants (nonionic, anionic, cationic, amphoteric), moisturizers, water functional polymers, film agents, ultraviolet absorbers, sequestering agents, lower alcohols, polyhydric alcohols, sugars, amino acids, pH adjusters, vitamins, antioxidants, pigments, preservatives, fragrances and the like.

There is no particular limitation on the dosage form and usage form of composition (I). The composition can be used, for example, in the form of lotion, emulsion, cream, gel, foam or mist.

Specific examples of composition (I) include shampoos, rinses, treatments, conditioners, and styling agents. A rinse, a treatment or a conditioner is preferable from the viewpoint of handling properties in hairdressing salons and the like.

The basic dye contained in the composition (II) is not particularly limited in kind as long as it is effective.具体的には、例えば、ＢａｓｉｃＢｌｕｅ３、Ｂａｓｉｃ Ｂｌｕｅ６、ＢａｓｉｃＢｌｕｅ７、Ｂａｓｉｃ Ｂｌｕｅ９、ＢａｓｉｃＢｌｕｅ２６、Ｂａｓｉｃ Ｂｌｕｅ４１、ＢａｓｉｃＢｌｕｅ４７、Ｂａｓｉｃ Ｂｌｕｅ７５、ＢａｓｉｃＢｌｕｅ９９、Ｂａｓｉｃ Ｂｒｏｗｎ４、ＢａｓｉｃＢｒｏｗｎ１６、Ｂａｓｉｃ Ｂｒｏｗｎ１７、ＢａｓｉｃＧｒｅｅｎ１、Ｂａｓｉｃ Ｇｒｅｅｎ４、ＢａｓｉｃＯｒａｎｇｅ１、Ｂａｓｉｃ Ｏｒａｎｇｅ２、ＢａｓｉｃＯｒａｎｇｅ３１、Ｂａｓｉｃ Ｒｅｄ１、ＢａｓｉｃＲｅｄ２、Ｂａｓｉｃ Ｒｅｄ２２、ＢａｓｉｃＲｅｄ４６、Ｂａｓｉｃ Ｒｅｄ５１、ＢａｓｉｃＲｅｄ７６、Ｂａｓｉｃ Ｒｅｄ１１８、ＢａｓｉｃＶｉｏｌｅｔ１、Ｂａｓｉｃ Ｖｉｏｌｅｔ３、ＢａｓｉｃＶｉｏｌｅｔ４、Ｂａｓｉｃ Ｖｉｏｌｅｔ１０、ＢａｓｉｃＶｉｏｌｅｔ１１、Ｂａｓｉｃ Ｖｉｏｌｅｔ１４、ＢａｓｉｃＶｉｏｌｅｔ１６、Ｂａｓｉｃ Ｙｅｌｌｏｗ１１、ＢａｓｉｃＹｅｌｌｏｗ２８、Ｂａｓｉｃ Ｙｅｌｌｏｗ５７、ＢａｓｉｃＹｅｌｌｏｗ８７等から選ばれる少なくとも１種Any of the above can be selected and used.

The amount of the basic dye to be incorporated in composition (II) is not particularly limited as long as it is an effective amount. The blending amount of the basic dyes is usually preferably 0.05 to 5% by mass as a total amount. If it is 0.05% by mass or more, it is preferable because the hair dyeing effect can be realized, and if it is 5% by mass or less, it is preferable because dyeing of the skin and scalp can be suppressed.

Direct dyes other than the basic dyes may be blended into the composition (II), if desired. Preferred direct dyes include HC dyes. As a result, it is possible to create a dyed hair color with a tone that cannot be obtained with the basic dye alone. In general, from the viewpoint of electrical compatibility, it is preferable to avoid blending an acid dye. However, an acid dye can be blended within a range that does not impair the effects of the present invention.

The HC dyes are not particularly limited, but for example, HC Blue2, HC Blue5, HC Blue6, HC Blue9, HC Blue10, HC Blue11, HC Blue12, HC Blue13, HC Orange1, HC Orange2, HC Orange3, HC Red1, HC Red 3, HC Red 7, HC Red 10, HC Red 11, HC Red 13, HC Red 14, HC Violet 1, HC Violet 2, HC Yellow 2, HC Yellow 4, HC Yellow 5, HC Yellow 9, HC Yellow 10, HC Yellow 11, HC Yellow 1, HC Yellow 1, HC Yellow 1, HC Yellow 3, Yellow yellow 12 HC Yellow 15 and the like. These can be arbitrarily selected and used.

The pH of composition (II) is not particularly limited as long as the action of the present invention is effective. Preferably, the pH is 6.0-8.0. When the pH is 6.0 or higher, hair dyeability can be improved, and when the pH is 8.0 or lower, hair damage can be suppressed, which is preferable.

Composition (II) may optionally contain other components than the basic dye as long as they do not inhibit the action of the present invention. Examples of the other ingredients include known ingredients conventionally added to cosmetics and other functional ingredients. Specific examples of other components include fats and oils, hydrocarbon oils, higher fatty acids, higher alcohols, ester oils, silicone oils, surfactants (nonionic, anionic, cationic, amphoteric), moisturizers, water functional polymers, film agents, ultraviolet absorbers, sequestering agents, lower alcohols, polyhydric alcohols, sugars, amino acids, pH adjusters, vitamins, antioxidants, pigments, preservatives, fragrances and the like.

There are no particular restrictions on the dosage form and usage form of composition (II). The composition can be used in the form of lotion, emulsion, cream, gel or foam, for example.

Specific examples of composition (II) include shampoos, rinses, treatments, conditioners, and styling agents. A rinse, a treatment or a conditioner is preferable from the viewpoint of handling properties in hairdressing salons and the like.

Compositions (I) and (II) may be a one-part formulation containing effective amounts of both the converted keratin and the basic dye. Compositions (I) and (II) may also be two-part formulations comprising a first part containing an effective amount of converted keratin and a second part containing an effective amount of the basic dye. In the case of a two-agent formulation, the specific compositions of the first agent and the second agent are not particularly limited. The compositions of the first agent and the second agent may be the same or different. In the case of a two-agent formulation, the converted keratin may be contained only in the first agent or may be contained in both the first agent and the second agent. The basic dye may be contained only in the second agent, or may be contained in both the first agent and the second agent. After treating the hair with the first agent, the hair may be treated with the second agent, or the hair may be treated with a mixture of the first agent and the second agent.

The order of steps (I) and (II) is not particularly limited as long as the action of the present invention is effective. For example, step (I) may be followed by step (II), or steps (I) and (II) may be performed simultaneously.

In the present invention, the hair can optionally be treated with a composition (composition (III)) containing one or more reducing agents (step (III)). The reducing agent can reduce the disulfide bonds contained in the converted keratin and/or the hair fibers to be treated and convert them into thiol groups. As a result, the converted keratin can be easily fixed inside the hair, and by loosening the hair tissue, the permeability of the basic dye can be improved.

The type of the reducing agent is not particularly limited as long as it can achieve the conversion to the thiol group. Specific examples of the reducing agent include thioglycolic acid, thiolactic acid, sulfurous acid, cysteamine, cysteine, spironolactone, and salts or derivatives thereof (eg, esters) of these reducing agents. The reducing agent may be used singly or in combination of two or more. Moreover, the content of the reducing agent in the composition (III) is not particularly limited as long as it is an effective amount.

Compositions (I) and (III) may be a one-part formula containing effective amounts of both the converted keratin and the reducing agent. Compositions (I) and (III) may also be two-agent formulations comprising a first agent containing an effective amount of converted keratin and a second agent containing an effective amount of the reducing agent. In the case of a two-agent formulation, the specific compositions of the first agent and the second agent are not particularly limited. The compositions of the first agent and the second agent may be the same or different. In the case of a two-agent formulation, the converted keratin may be contained only in the first agent, or may be contained in both the first agent and the second agent. The reducing agent may be contained only in the second agent, or may be contained in both the first agent and the second agent. After treating the hair with the first agent, the hair may be treated with the second agent, or after treating the hair with the second agent, the hair may be treated with the first agent. Furthermore, the hair may be treated with a mixture of the first agent and the second agent.

In the present invention, the hair can optionally be treated with a composition containing one or more oxidizing agents (composition (IV)) (step (IV)). This processing can further improve the effects of the present invention. The oxidizing agent is capable of forming disulfide bonds between thiol groups. Thereby, the converted keratin and the keratin protein contained in the hair can be bound via disulfide bonds. As a result, the hair tissue can be further strengthened, and the properties of the hair can be more effectively improved to a healthy state. In addition, by further strengthening the hair tissue, the retention property is improved, and the durability of the color of the basic dye that has permeated the inside of the hair can be further improved.

The type of the oxidizing agent is not particularly limited as long as it can form a disulfide bond between thiol groups. Specific examples of the oxidizing agent include hydrogen peroxide, bromic acid and salts thereof. The oxidizing agents may be used singly or in combination of two or more. The content of the oxidizing agent in composition (IV) is not particularly limited as long as it is an effective amount.

When performing steps (III) and (IV), there is no particular limitation on the order. In the present invention, step (IV) is preferably carried out after step (III). Moreover, it is preferable to carry out a step of washing away the composition (III) used in step (III) between step (III) and step (IV).

Also, the order of steps (I) to (IV) is not particularly limited. For example, after step (I), step (III) may be performed, or step (I) and step (III) may be performed simultaneously. Furthermore, steps (I) to (III) may be performed simultaneously. Moreover, step (IV) may be performed after step (II), or step (II) and step (IV) may be performed simultaneously.

A preferred embodiment is one in which step (I), step (III), step (II), and step (IV) are performed in this order. In this case, steps (I) and (III) may be performed simultaneously, steps (II) and (IV) may be performed simultaneously, and steps (I) to (III) may be performed simultaneously.

EXAMPLES The present invention will be specifically described below with reference to Examples. It should be noted that the present invention is not limited to the forms shown in the examples. The embodiments of the present invention can be variously modified within the scope of the present invention depending on the purpose and application. Moreover, it should be added that all considerations of the results in the examples are nothing more than the views of the inventors, and are not explanations for the purpose of defining the present invention.

Examples 1-2 and Comparative Examples 1-6

After performing steps (I) and (II) on highly damaged hair, evaluate the physical properties of the hair by a hair tensile test, and evaluate the hair dyeability, levelness, and color retention by a hair dyeing test. gone. Furthermore, after performing steps (I) to (IV) on highly damaged hair, evaluation of the physical properties of the hair by a hair tensile test, and hair dyeing, leveling, and color retention by a hair dyeing test made an evaluation.

(I) Preparation of Hair Treatment Composition Compositions of Formulation Examples 1 to 4 shown in Tables 1 and 2 were prepared according to a conventional method. The numerical values in Tables 1 and 2 indicate the contents of the components in the corresponding column, and the unit is % by mass. Formulation Example 1 is a composition containing converted keratin (composition (I)), and Formulation Example 4 is a composition containing a basic dye (composition (II)).

(II) Preparation of hair bundles for evaluation Highly damaged hair Bleaching agent 1 (“Lecee Powder Bleach EX” manufactured by Hoyu Co., Ltd.) and bleaching agent 2 (“Ordeve Addicthy Oxidan 6%” manufactured by Milbon Co., Ltd.) were combined in 1:1. A bleach mixture was obtained by uniformly mixing at a ratio of 2.5 (mass ratio). An equal amount of the bleaching mixture was applied to a hair bundle (“test hair bundle 1 g 10 cm human hair black” manufactured by Staffs Co., Ltd.), left at 25° C. for 30 minutes, and thoroughly washed with water. This bleaching process was performed twice. The hair tress was immersed in a 1.0 mass % sodium lauryl sulfate solution at 25°C for 5 minutes. The tresses were then washed with water and then dried. This hair bundle was used as a hair bundle for evaluation.

(III) Treatment with Compositions of Formulation Examples 1 to 4 1 g of each of the compositions of Formulation Examples 1 to 3 was evenly applied to one hair tress for evaluation and left at 25° C. for 10 minutes. After that, it was washed well with water and wiped off with a towel. Next, 1 g of the composition of Formulation Example 4 was evenly applied to one treated hair tress and left at 25° C. for 10 minutes. After that, it was thoroughly washed with water and dried.

(IV) Treatment with a composition containing a reducing agent and a composition containing an oxidizing agent The compositions of Formulation Examples 1 to 3 and a composition containing a reducing agent (“Likera Activator” manufactured by Little Scientist Co., Ltd.) were treated at 20: Mixed liquid 1 was prepared by uniformly mixing at a ratio of 1 (mass ratio). Then, 1 g of the mixture 1 was uniformly applied to one hair bundle for evaluation, and left at 25° C. for 10 minutes. After that, it was washed well with water and wiped off with a towel. Next, the composition of Formulation Example 4 and a composition containing an oxidizing agent (“Likera 3D Anchor Cream” manufactured by Little Scientist Co., Ltd.) are uniformly mixed at a ratio of 1:1 (mass ratio) to obtain a mixture 2. prepared. Next, 2 g of the mixed solution 2 was uniformly applied to one treated hair bundle, and left at 25° C. for 10 minutes. After that, the hair tress was thoroughly washed with water and dried. The reason why 2 g of the mixed liquid 2 was applied to one hair bundle is to match the application amount of the basic dye to one hair bundle with the method (III).

(A) Hair tensile test A universal tensile tester ("AG-20k NXDplus" manufactured by Shimadzu Corporation) is used on the hair bundles treated by the methods (III) and (IV) above at a speed of 50 mm / min. The tensile breaking strength (N) and elongation rate (%) per hair were measured (n=10), and the results were evaluated as an index of hair damage.

(B) Dyeability and levelness evaluation test The dyeability and levelness of the hair tresses treated by the methods (III) and (IV) were evaluated by 10 panelists. Dyeability was evaluated on a 5-point scale based on the color intensity of the basic hair dye on the tress. The levelness of dyeing was evaluated on a 5-point scale depending on whether or not the hair tresses were uniformly colored with the basic hair dye.
(B-1) Dyeability evaluation 5: Good dyeing 4: Slightly good dyeing 3: Dyed 2: Slightly poor dyeing 1: Poor dyeing (B-2) Level dyeing evaluation 5: Good and uniform dyeing 4: Slightly good and uniform dyeing 3: Uniform dyeing 2: Slightly non-uniform dyeing 1: Non-uniform dyeing

(C) Color Retention Evaluation Test The hair tresses treated by the methods (III) and (IV) were immersed in a 1.0% by mass sodium lauryl sulfate solution at 25° C. for 30 minutes. After that, it was thoroughly washed with water and dried. A panel of 10 people observed the degree of fading of the color of the hair tress, and evaluated the color durability in 5 stages.
(C-1) Fastness evaluation 5: Not faded 4: Slightly faded 3: Faded but within acceptable range 2: Faded 1: Very faded

The above test (A) was also performed on healthy hair and hair tresses for evaluation. As for healthy hair, a hair bundle (manufactured by Staffs Co., Ltd. "test hair bundle 1 g 10 cm human hair black") was immersed in a 1.0% by mass sodium lauryl sulfate solution at 25° C. for 5 minutes. It was then washed with water and dried. This hair bundle was used as a healthy hair bundle. Further, the above tests (B) and (C) were also performed on the hair tresses for evaluation. Comparative Example 5 was obtained by using these results as a standard for comparing the properties of healthy hair and untreated highly damaged hair. The degree of hair damage repair by the treatments (III) and (IV) was evaluated in comparison with these values.

Table 3 shows the average value of the above evaluation test results.

From Table 3, the hair treated with the composition containing aminoethyl disulfide keratin, which is converted keratin (Examples 1 and 2), exhibits physical properties very similar to those of healthy hair (Comparative Example 5). Furthermore, comparing Examples 1 and 2, the hair treated with the reducing agent and the oxidizing agent (Example 2) is more effective. This is because the disulfide bonds contained in aminoethyl disulfide keratin and the disulfide bonds in keratin in the hair are cleaved by a reducing agent and then treated with an oxidizing agent, so that the aminoethyl disulfide keratin and the keratin protein in the hair form disulfide bonds. It is presumed that the hair was fixed firmly through bonding, and the hair damage repairing effect was further enhanced. In this embodiment, the treatment method can be freely changed depending on the level of damage to the hair, so it is possible to deal with a wide range of hair types.

Furthermore, in Examples 1 and 2, the dyeability, level dyeability and color retention with basic hair dyes are greatly improved. This is because the aminoethyl disulfide keratin effectively repairs the hair tissue, thereby improving dyeability with basic hair dyes, compared to hair treated with hydrolyzed keratin (Comparative Examples 1 and 2). It shows what you can do. Specifically, since the aminoethyl disulfide keratin can efficiently adsorb cysteic acid (—SO ₃ ⁻ ) generated by hair damage, the hair can be dyed by adjusting the electrical balance of the hair. It is presumed that the dyeing property and level dyeing property were improved. Furthermore, it is presumed that aminoethyl disulfide keratin strengthens the hair tissue, thereby improving the lockability and making it difficult for the basic dye to flow out from the inside of the hair.

As described above, the above-mentioned hair treatment method capable of repairing damaged hair and dyeing hair at the same time is widely used and practical, and has a high utility value in the field of the beauty industry.

Claims (2)

(I) (A) some or all of the disulfide bonds (-SS-) in keratin have been converted with at least one of thiol compounds selected from the group consisting of cysteamine and thioglycolic acid and sulfite; A keratin derivative , or (B) some or all of the disulfide bonds (-SS-) in keratin are converted with at least one of a thiol compound selected from the group consisting of cysteamine and thioglycolic acid and sulfite. and (II) treating the hair with a composition containing one or more basic dyes;
A method of treating hair, comprising: (III) treating the hair with a composition containing one or more reducing agents; and (IV) treating the hair with a composition containing one or more oxidizing agents;
2. The method of treating hair according to claim 1, further comprising: