Hair shape imparting method

Abstract

A method for imparting a hair shape, which comprises the following steps in this order: step 1A: a step for applying an A1 agent, which contains a component (a1) a reducing agent and has a pH value of 8-11, to hair, and then applying a B1 agent, which contains a component (b1) 0.03-0.3 mass% of a melanin precursor and a component (b2) an alkaline agent and has a pH value of 8-11, to hair; or step (1B): a step for applying an agent A2 to the hair, said agent A2 containing 0.03-0.3 mass% of a component (a1) reducing agent and a component (a2) melanin precursor and having a pH value of 8-11; and step 2: a step for imparting a shape to the hair. The hair shape imparting method further comprises, in the following order: step 3: a step for applying an agent C containing an oxidizing agent to the hair; and step 4: a step for rinsing the hair.

Description

Technical Field

[0001] The present invention relates to a method for imparting shape to hair. Background Art

[0002] Conventional perming techniques have long been known, using reducing agents such as thioglycolic acid to break the disulfide bonds of the keratin that makes up hair, giving the hair a straight or curly shape, and then fixing it with hydrogen peroxide. However, existing perming techniques suffer from the problem of losing hair's elasticity, toughness, and resilience due to the weakening of hair's physical properties caused by the chemical treatments.

[0003] For example, the specification of Chinese Patent Application Publication No. 111920696 (Patent Document 1) sets as its subject the provision of a method for using a hair dye that can simultaneously dye and perm hair using a safe and non-toxic specified melanin precursor, thereby improving color fastness, shortening dyeing time, and reducing damage to hair. The method discloses the following: after preparing a reducing agent solution and a preparation containing cystine and a specified melanin precursor, the hair is applied within a specified temperature range to form the hair into an arbitrary shape; after a specified time, an oxidizing agent solution is evenly applied to the hair; after the specified time, the hair is shampooed; and a preparation containing a specified melanin precursor, a buffer solution, and an oxidizing agent is applied to the hair and maintained within a specified temperature range for a specified time.

[0004] In addition, recently, due to the development of hair heating devices such as hair irons, it is easy to give straight or curly shapes to hair in daily styling. However, the shape given by hair irons etc. generally returns to its original shape by washing the hair.

[0005] Therefore, Japanese Patent Application Laid-Open No. 2019-94328 (Patent Document 2) aims to provide a hair treatment method that imparts shape to hair without chemically modifying hair protein and maintains the shape even after shampooing. The method discloses a method comprising the steps of applying a composition containing a predetermined melanin precursor to the hair and imparting shape to the hair at a temperature within a predetermined range. Summary of the Invention

[0006] The present invention relates to the following [1].

[0007] [1] A method for imparting a shape to hair, wherein:

[0008] In order:

[0009] Step 1A: a step of applying Agent A1 to the hair and then applying Agent B1 to the hair; or Step 1B: a step of applying Agent A2 to the hair; and

[0010] Step 2: The step of giving shape to the hair.

[0011] Further in sequence:

[0012] Step 3: a step of applying agent C containing an oxidizing agent to the hair; and

[0013] Step 4: Rinse the hair.

[0014] The A1 agent contains the following ingredient (a1) and has a pH value of 8 to 11.

[0015] (a1) a reducing agent,

[0016] The B1 agent contains the following components (b1) and (b2), and has a pH value of 8 to 11.

[0017] (b1) a compound represented by the following general formula (1) or a salt thereof, wherein the content thereof is 0.03 to 0.3% by mass;

[0018]

[0019] (where the dashed line indicates the presence or absence of a π bond, R 1 represents a hydroxyl group or an acetoxy group, R 2 represents a hydrogen atom or -COOR (R represents a hydrogen atom, a methyl group or an ethyl group), R 3 represents a hydrogen atom, an acetyl group, a methyl group, or an ethyl group.)

[0020] (b2) alkali agents,

[0021] The A2 agent contains the following ingredients (a1) and (a2), and has a pH value of 8 to 11.

[0022] (a1) reducing agent;

[0023] (a2) A compound represented by the following general formula (1) or a salt thereof, wherein the content thereof is 0.03 to 0.3% by mass.

[0024]

[0025] (where the dashed line indicates the presence or absence of a π bond, R 1 represents a hydroxyl group or an acetoxy group, R 2 represents a hydrogen atom or -COOR (R represents a hydrogen atom, a methyl group or an ethyl group), R 3 represents a hydrogen atom, an acetyl group, a methyl group, or an ethyl group.) DETAILED DESCRIPTION

[0026] However, the method described in Patent Document 1 has the problem that it cannot simply give shape to the hair when dyeing is not desired. In addition, the method described in Patent Document 2 still has room for improvement in terms of the shampoo resistance of the hair shape given.

[0027] The present invention relates to a method for imparting a hair style having sufficient shampoo resistance without changing the hair color, without impairing the elasticity and toughness of the hair, and with excellent hair manageability.

[0028] The present inventors have discovered that the above-mentioned problems can be solved by a method for styling hair that sequentially comprises: applying an agent A1 containing a reducing agent to the hair, followed by applying an agent A2 containing a predetermined melanin precursor to the hair (step 1A); or applying an agent B1 containing a reducing agent and a predetermined melanin precursor to the hair (step 1B); and a step of styling the hair (step 2); and further sequentially comprises applying an agent C containing an oxidizing agent to the hair (step 3); and rinsing the hair (step 4). The present invention has been thus achieved.

[0029] According to the present invention, there can be provided a method for imparting a hair styling which is capable of imparting a sufficient shampoo-resistant hair styling without changing the hair color, without impairing the elasticity and toughness of the hair, and which provides an excellent sense of hair management.

[0030] [definition]

[0031] In the present specification, "no change in hair color" means that the absolute value of the change in L value before and after hair treatment is small, and specifically, it can be evaluated by the method described in the Examples.

[0032] In this specification, "having sufficient shampoo resistance" means that the hair maintains the given shape even after repeated shampooing treatments with a shampoo several times, and can be specifically evaluated by the method described in the Examples.

[0033] [Hair shaping method]

[0034] The hair styling method of the present invention (hereinafter also referred to as "the method of the present invention") comprises the following steps:

[0035] Step 1A: a step of applying Agent A1 to the hair and then applying Agent B1 to the hair; or Step 1B: a step of applying Agent A2 to the hair; and

[0036] Step 2: The step of giving shape to the hair.

[0037] Further in sequence:

[0038] Step 3: a step of applying agent C containing an oxidizing agent to the hair; and

[0039] Step 4: The step of rinsing the hair, wherein:

[0040] The above-mentioned A1 agent contains the following ingredient (a1) and has a pH value of 8 to 11.

[0041] (a1) a reducing agent,

[0042] The above-mentioned B1 agent contains the following components (b1) and (b2), and has a pH value of 8 to 11.

[0043] (b1) a compound represented by the following general formula (1) or a salt thereof, wherein the content thereof is 0.03 to 0.3% by mass;

[0044]

[0045] (where the dashed line indicates the presence or absence of a π bond, R 1 represents a hydroxyl group or an acetoxy group, R 2 represents a hydrogen atom or -COOR (R represents a hydrogen atom, a methyl group or an ethyl group), R 3 represents a hydrogen atom, an acetyl group, a methyl group, or an ethyl group.)

[0046] (b2) alkali agents,

[0047] The above-mentioned A2 agent contains the following components (a1) and (a2), and has a pH value of 8 to 11.

[0048] (a1) reducing agent;

[0049] (a2) A compound represented by the following general formula (1) or a salt thereof, wherein the content thereof is 0.03 to 0.3% by mass.

[0050]

[0051] (where the dashed line indicates the presence or absence of a π bond, R 1 represents a hydroxyl group or an acetoxy group, R 2 represents a hydrogen atom or -COOR (R represents a hydrogen atom, a methyl group or an ethyl group), R 3 represents a hydrogen atom, an acetyl group, a methyl group, or an ethyl group.)

[0052] The present invention, by employing the above-described structure, can impart sufficient shampoo-resistant hair shape without altering hair color, without compromising hair elasticity or toughness, and with excellent hair manageability. Specifically, in the method of the present invention, after treating hair with Agent A1 containing a reducing agent and then applying Agent B1 containing a predetermined melanin precursor, or applying Agent A2 containing a reducing agent and a predetermined melanin precursor, the shaped hair exhibits improved manageability while maintaining its elasticity or toughness compared to hair not treated with the predetermined melanin precursor. The detailed reason for this effect is unclear, but it is believed that the reducing agent breaks the disulfide bonds of the keratin proteins that constitute the hair, allowing the hair to come into contact with the melanin precursor, which then penetrates the hair. Subsequently, during the rinsing step, the melanin precursor forms polymers within the hair, thereby maintaining hair manageability while maintaining its elasticity or toughness. Furthermore, by controlling the content of the predetermined melanin precursor in Agent B1 or Agent A2 to be within a specific range, the hair color does not change before and after the treatment.

[0053] <Steps 1A and 1B>

[0054] Step 1A is the step of applying the following Agents A1 and B1 to the hair. Step 1B is the step of applying the following Agent A2 to the hair. The method of the present invention preferably includes Step 1A from the perspective of achieving good elasticity, firmness, and manageable hair. Furthermore, from the perspective of simplifying the process, it is preferably included with Step 1B.

[0055] (Dose A)

[0056] Agent A is Agent A1 containing the following component (a1) and having a pH of 8 to 11, or Agent A2 containing the following components (a1) and (a2) and having a pH of 8 to 11. Hereinafter, Agent A1 and Agent A2 are also referred to as Agent A.

[0057] (a1) reducing agent;

[0058] (a2) 0.03 to 0.3% by mass of a compound represented by the following general formula (1) or a salt thereof.

[0059]

[0060] (where the dashed line indicates the presence or absence of a π bond, R 1 represents a hydroxyl group or an acetoxy group, R 2 represents a hydrogen atom or -COOR (R represents a hydrogen atom, a methyl group or an ethyl group), R 3 represents a hydrogen atom, an acetyl group, a methyl group, or an ethyl group.)

[0061] <<Component (a1): Reducing Agent>>

[0062] Reducing agents can cleave disulfide bonds in the keratin that constitutes hair. Examples of reducing agents include thioglycolic acid and its derivatives, thiolactic acid and its derivatives, cysteine ​​and its derivatives, or salts thereof. Specific examples of reducing agents include thioglycolic acid, ammonium thioglycolate, thioglycolic acid glyceride, L-cysteine, D-cysteine, N-acetylcysteine, ammonium salts of these cysteines, ethanolamine salts such as monoethanolamine, diethanolamine, and triethanolamine, thioglyceryl alkyl ethers such as ethoxyhydroxypropyl mercaptan, methoxyethoxyhydroxypropyl mercaptan, and isopropoxyethoxyhydroxypropyl mercaptan, mercaptoethyl propionamide, and mercaptoethyl glucamide. Among these, it is preferred that it contains one or more selected from thioglycolic acid, ammonium thioglycolate, thioglycolic acid glyceride, L-cysteine, D-cysteine, N-acetylcysteine, and ammonium salts of these cysteines, and it is more preferred that it contains one or more selected from thioglycolic acid, ammonium thioglycolate, and thioglycolic acid glyceride.

[0063] From the perspective of imparting a shape with sufficient shampoo resistance, good elasticity, firmness, and a manageable feel to the hair, the content of the reducing agent in Agent A is preferably 0.1% by mass or greater, more preferably 1% by mass or greater, even more preferably 2% by mass or greater, and even more preferably 5% by mass or greater. Furthermore, it is preferably 40% by mass or less, more preferably 20% by mass or less, even more preferably 15% by mass or less, and even more preferably 10% by mass or less. From this perspective, the content of the reducing agent in Agent A is preferably 0.1 to 40% by mass, more preferably 1 to 20% by mass, even more preferably 2 to 15% by mass, and even more preferably 5 to 10% by mass.

[0064] <<Ingredient (a2): Melanin Precursor>>

[0065] The melanin precursor of component (a2) is an indole derivative or indoline derivative, or a salt thereof, which is a compound represented by general formula (1). In the present invention, one kind or a combination of two or more kinds can be used.

[0066] Examples of the compound represented by the general formula (1) include 5,6-dihydroxyindole, 5,6-dihydroxyindole-2-carboxylic acid, 5,6-dihydroxyindole-2-carboxylic acid methyl ester, 5,6-dihydroxyindole-2-carboxylic acid ethyl ester, N-methyl-5,6-dihydroxyindole, N-methyl-5,6-dihydroxyindole-2-carboxylic acid, N-ethyl-5,6-dihydroxyindole, N-ethyl-5,6-dihydroxyindole-2-carboxylic acid, N-acetyl-5,6-dihydroxyindole, N-acetyl-5,6-dihydroxyindole-2-carboxylic acid, 5-acetoxy-6-hydroxyindole, 5-acetoxy-6-hydroxyindole-2-carboxylic acid. -carboxylic acid, 5,6-dihydroxyindoline, 5,6-dihydroxyindoline-2-carboxylic acid, 5,6-dihydroxyindoline-2-carboxylic acid methyl ester, 5,6-dihydroxyindoline-2-carboxylic acid ethyl ester, N-methyl-5,6-dihydroxyindoline, N-methyl-5,6-dihydroxyindoline-2-carboxylic acid, N-ethyl-5,6-dihydroxyindoline, N-ethyl-5,6-dihydroxyindoline-2-carboxylic acid, N-acetyl-5,6-dihydroxyindoline, N-acetyl-5,6-dihydroxyindoline-2-carboxylic acid, 5-acetoxy-6-hydroxyindoline, 5-acetoxy-6-hydroxyindoline-2-carboxylic acid, etc.

[0067] Examples of salts of the compound represented by general formula (1) include hydrochlorides, hydrobromides, sulfates, phosphates, acetates, propionates, lactates, citrates, etc. Among these, hydrobromides of the compound are preferred from the viewpoint of availability.

[0068] In addition, in the general formula (1), R 2 When -COOH is present, examples of the salt of the compound represented by the general formula (1) include carboxylates thereof (R 2 -COO - X + (X + for Na + , K + Alkali metal ions, Ca + Mg + alkaline earth metal ions, ammonium ions and other cations)).

[0069] From the viewpoint of imparting a shape to hair having sufficient shampoo resistance and obtaining good elasticity, firmness, and manageability, component (a2) preferably contains one or more selected from 5,6-dihydroxyindole, 5,6-dihydroxyindoline, 5,6-dihydroxyindoline-2-carboxylic acid, and salts thereof. It is more preferred that the component (a2) contains one or more selected from 5,6-dihydroxyindole, 5,6-dihydroxyindoline, 5,6-dihydroxyindole-2-carboxylic acid, and 5,6-dihydroxyindoline hydrobromide. It is even more preferred that the component (a2) contains one or more selected from 5,6-dihydroxyindole and 5,6-dihydroxyindole-2-carboxylic acid. It is even more preferred that the component (a2) contains 5,6-dihydroxyindole and 5,6-dihydroxyindole-2-carboxylic acid.

[0070] When component (a2) contains 5,6-dihydroxyindole and 5,6-dihydroxyindole-2-carboxylic acid, the molar ratio of 5,6-dihydroxyindole to 5,6-dihydroxyindole-2-carboxylic acid is preferably in the range of 50:50 to 99:1, more preferably in the range of 80:20 to 99:1, and even more preferably in the range of 85:15 to 95:5, from the viewpoint of imparting a shape having sufficient shampoo resistance to the hair and obtaining good elasticity, firmness, and a manageable feel to the hair.

[0071] When component (a2) contains 5,6-dihydroxyindole and 5,6-dihydroxyindole-2-carboxylic acid, the molar ratio of 5,6-dihydroxyindole to 5,6-dihydroxyindole-2-carboxylic acid in component (a2) can be quantified by reverse phase HPLC.

[0072] When Agent A is Agent A2 containing Component (a2), the content of Component (a2) in Agent A2 is 0.03 to 0.3% by mass, preferably 0.05 to 0.25% by mass, more preferably 0.055 to 0.2% by mass, further preferably 0.06 to 0.1% by mass, and still more preferably 0.065 to 0.08% by mass, from the viewpoint of imparting a shape having sufficient shampoo resistance to the hair and obtaining good elasticity, firmness, and a manageable feel to the hair.

[0073] Here, when Agent A is Agent A2 and Agent A2 is applied to the hair, the ratio of the treatment amount of component (a1) to component (a2) per unit dry mass of hair [(a1) / (a2)] is preferably 20 or more, more preferably 65 or more, and even more preferably 80 or more, from the viewpoint of not changing the hair color. From the viewpoint of maintaining a sense of manageability, elasticity, and not changing the hair color, it is preferably 250 or less, more preferably 150 or less, and even more preferably 100 or less. Furthermore, it is preferably 20 to 250, more preferably 65 to 150, and even more preferably 80 to 100.

[0074] In this method, the ratio of the compounding amounts of the component (a1) and the component (a2) compounded in the Agent A2 is directly the same as the treatment amount ratio. Therefore, it is only necessary to prepare Agent A2 by compounding each component in such a way as to achieve the desired treatment amount ratio.

[0075] <<pH value>>

[0076] From the viewpoint of being able to endow a hair shape with sufficient wash resistance, and enabling the hair to obtain good elasticity or toughness and neatness, the pH value of Agent A is 8 to 11, more preferably 8.5 to 10.5. The pH value of Agent A can be adjusted by adding a known pH value regulator.

[0077] The above pH value is the measured value at 25°C. Specifically, it can be measured by the method described in the examples.

[0078] In addition to a reducing agent and a specified melanin precursor, Agent A may further contain components commonly used in cosmetic compositions, such as: aqueous media such as water, lower alcohols, low molecular weight diols, and triols; pH value regulators; surfactants; antioxidants; viscosity regulators; silicones; aromatic alcohols; coloring components other than the component (a2); polymers; oil agents; anti-dandruff agents; vitamin agents; bactericides; anti-inflammatory agents; preservatives; chelating agents; moisturizing agents; pearlescent agents; ceramides; fragrances; ultraviolet absorbers, etc.

[0079] There is no particular limitation on the dosage form of Agent A, and it can be made into any dosage form such as liquid, foam, paste, cream, solid, powder, etc. From the viewpoint of applying it to the hair by coating, impregnation, etc., the dosage form of Agent A is preferably liquid, paste or cream.

[0080] There is no particular limitation on the preparation method of Agent A. For example, it can be prepared by compounding the component (a1), the component (a2), and other components used as needed, and mixing them using a known stirring device, etc.

[0081] (Applying Agent A to the hair)

[0082] The hair when applying Agent A can be either in a dry state or a wet state. From the viewpoint of being able to endow a hair shape with sufficient wash resistance, and enabling the hair to obtain good elasticity or toughness and neatness, in terms of the bath ratio (dry mass of hair: mass of water), it is preferably 1:0.​​The method of applying Agent A to the hair may be any method that allows Agent A to come into contact with the hair, and examples thereof include a method of applying Agent A to the hair and a method of immersing the hair in Agent A.

[0084] From the perspective of achieving a balance between imparting a hair shape with sufficient shampoo resistance and economic efficiency, the amount of Agent A applied to the hair is preferably in the range of 1:0.2 to 1:20, more preferably 1:0.5 to 1:10, and even more preferably 1:1 to 1:5, in terms of bath ratio (dry hair mass: mass of Agent A).

[0085] The hair to be applied is preferably the head of the head, and may be at least a part of the head of the head.

[0086] The time during which Agent A is applied to the hair, i.e., the total time during which Agent A is applied to or immersed in the hair and the time during which the hair is left to stand, can be varied as appropriate. From the perspective of allowing the components of Agent A to penetrate the hair, it is preferably 3 minutes or longer, more preferably 5 minutes or longer, and even more preferably 10 minutes or longer. From the perspective of reducing the burden on the operator, it is preferably 90 minutes or shorter, more preferably 60 minutes or shorter, even more preferably 45 minutes or shorter, and even more preferably 30 minutes or shorter. From this perspective, the time during which Agent A is applied to the hair is preferably 3 to 90 minutes, more preferably 5 to 60 minutes, even more preferably 10 to 45 minutes, and even more preferably 10 to 30 minutes.

[0087] The temperature when applying Agent A to the hair is not particularly limited. However, from the perspective of the handleability of Agent A, it is preferably 40°C or lower, more preferably 35°C or lower. Furthermore, from the perspective of imparting a shape with sufficient shampoo resistance to the hair and achieving good elasticity, firmness, and a manageable feel to the hair, it is preferably 20°C or higher, more preferably 25°C or higher. From these perspectives, the temperature when applying Agent A to the hair is preferably 20-40°C, more preferably 25-35°C.

[0088] From the perspective of removing components of Agent A that have not penetrated the hair, the method of the present invention preferably includes a step of rinsing the hair (hereinafter referred to as a "rinsing step") after applying Agent A to the hair and, in the case of Agent A1, before applying Agent B1 described below; and, in the case of Agent A2, before applying Step 2 described below. The rinsing step can be performed, for example, by rinsing the applied Agent A with water.

[0089] (B1 dose)

[0090] Agent B1 contains the following ingredients (b1) and (b2), and has a pH of 8 to 11.

[0091] (b1) 0.03 to 0.3% by mass of a compound represented by the following general formula (1) or a salt thereof;

[0092]

[0093] (where the dashed line indicates the presence or absence of a π bond, R 1 represents a hydroxyl group or an acetoxy group, R 2 represents a hydrogen atom or -COOR (R represents a hydrogen atom, a methyl group or an ethyl group), R 3 represents a hydrogen atom, an acetyl group, a methyl group, or an ethyl group.)

[0094] (b2) Alkali agent.

[0095] <<Ingredient (b1): Melanin Precursor>>

[0096] The melanin precursor of component (b1) is an indole derivative or indoline derivative, or a salt thereof, which is a compound represented by general formula (1). In the present invention, one or more of these can be used in combination. As component (b1), the compounds and salts thereof exemplified in component (a2) above can be cited. From the viewpoint of imparting a shape to hair having sufficient shampoo resistance and obtaining good elasticity, firmness, and manageability, component (b1) preferably contains one or more selected from 5,6-dihydroxyindole, 5,6-dihydroxyindoline, 5,6-dihydroxyindoline-2-carboxylic acid, and salts thereof. It is more preferred that the component (b1) contains one or more selected from 5,6-dihydroxyindole, 5,6-dihydroxyindoline, 5,6-dihydroxyindole-2-carboxylic acid, and 5,6-dihydroxyindoline hydrobromide. It is even more preferred that the component (b1) contains one or more selected from 5,6-dihydroxyindole and 5,6-dihydroxyindole-2-carboxylic acid. It is even more preferred that the component (b1) contains 5,6-dihydroxyindole and 5,6-dihydroxyindole-2-carboxylic acid.

[0097] When component (b1) contains 5,6-dihydroxyindole and 5,6-dihydroxyindole-2-carboxylic acid, the molar ratio of 5,6-dihydroxyindole to 5,6-dihydroxyindole-2-carboxylic acid is preferably in the range of 50:50 to 99:1, more preferably in the range of 80:20 to 99:1, and even more preferably in the range of 85:15 to 95:5, from the viewpoint of imparting a shape having sufficient shampoo resistance to the hair and obtaining good elasticity, firmness, and a manageable feel to the hair.

[0098] When the component (b1) contains 5,6-dihydroxyindole and 5,6-dihydroxyindole-2-carboxylic acid, the molar ratio of 5,6-dihydroxyindole to 5,6-dihydroxyindole-2-carboxylic acid in the component (b1) can be quantified by reverse phase HPLC.

[0099] From the viewpoint of imparting a shape having sufficient shampoo resistance to hair and obtaining good elasticity, firmness, and manageability, the content of component (b1) in agent B1 is 0.03 to 0.3% by mass, preferably 0.05 to 0.25% by mass, more preferably 0.055 to 0.2% by mass, further preferably 0.06 to 0.15% by mass, and still more preferably 0.065 to 0.1% by mass.

[0100] <<Ingredient (b2): Alkaline agent>>

[0101] Examples of the alkaline agent include ammonia; alkanolamines such as monomethanolamine, dimethanolamine, trimethanolamine, monoethanolamine, diethanolamine, or triethanolamine; alkylamines such as methylamine, dimethylamine, ethylamine, diethylamine, N-methylethylamine, propylamine, and butylamine; arylalkylamines such as benzylamine; and inorganic alkaline compounds such as sodium hydroxide, potassium hydroxide, sodium carbonate, sodium bicarbonate, ammonium carbonate, and ammonium bicarbonate. One or more of these can be used. From the perspective of water solubility, the alkanolamine, alkylamine, or arylalkylamine preferably has 10 or fewer carbon atoms, more preferably 8 or fewer.

[0102] Among these, from the viewpoint of imparting a shape to hair having sufficient shampoo resistance and achieving good elasticity, toughness, and manageability, the alkaline agent preferably comprises at least one selected from ammonia, alkanolamines, alkylamines, arylalkylamines, sodium hydroxide, potassium hydroxide, sodium carbonate, sodium bicarbonate, ammonium carbonate, and ammonium bicarbonate. It is more preferred that the alkaline agent comprises at least one selected from ammonia and alkanolamines, further preferably comprises monoalkanolamine, and even more preferably comprises monoethanolamine.

[0103] From the viewpoint of imparting a shape with sufficient shampoo resistance to hair and obtaining good elasticity, firmness, and manageability, the content of component (b2) in agent B1 is preferably 0.1 to 10% by mass, more preferably 0.5 to 8% by mass, and even more preferably 1 to 5% by mass.

[0104] <<Ingredient (b3): ​​Antioxidant>>

[0105] From the viewpoint of improving the stability of the component (b1), the agent B1 preferably further contains (b3) an antioxidant.

[0106] Examples of antioxidants include sulfurous acid, pyrosulfurous acid, hydrogen sulfite, sulfur dioxide, L-ascorbic acid, thioglycolic acid, L-cysteine, N-acetyl-L-cysteine, and salts and derivatives thereof. Salts are preferably alkali metals such as sodium and potassium.

[0107] Among these, the antioxidant preferably contains one or more selected from L-ascorbic acid, sulfurous acid, metabisulfurous acid, sodium bisulfite, or salts thereof, glucosyl ascorbate, and sulfur dioxide; more preferably contains one or more selected from L-ascorbic acid, sodium ascorbate, and sodium sulfite; and still more preferably contains one or more selected from L-ascorbic acid and sodium ascorbate.

[0108] When the agent B1 contains the component (b3), from the viewpoint of enhancing the stability of the component (b1), the content of the component (b3) in the agent B1 is preferably 0.05% by mass or more, more preferably 0.1% by mass or more, still more preferably 0.3% by mass or more, and preferably 10% by mass or less, more preferably 5% by mass or less, still more preferably 2% by mass or less. From the above viewpoints, it is preferably 0.05 to 10% by mass, more preferably 0.1 to 5% by mass, and still more preferably 0.3 to 2% by mass.

[0109] <<pH value regulator>>

[0110] From the viewpoint of adjusting the pH value to the desired range described below and promoting the polymerization reaction of the component (b1) in the hair to fix it to the hair, the agent B1 preferably further contains a pH value regulator.

[0111] Since the agent B1 contains an alkali agent as the component (b1), as the pH value regulator for the agent B1, a protonating agent is preferred. The protonating agent can be either a monobasic acid or a polybasic acid, and can be either an organic acid (having 1 to 8 carbon atoms, excluding ascorbic acid) or an inorganic acid.

[0112] Examples of such protonating agents include one or more selected from hydrochloric acid, sulfuric acid, phosphoric acid, formic acid, acetic acid, and citric acid, and preferably one or more selected from phosphoric acid and citric acid.

[0113] When the agent B1 contains a pH value regulator, from the viewpoint of adjusting the pH value of the agent B1 to the range described below, the content of the pH value regulator in the agent B1 is preferably 0.05% by mass or more, more preferably 0.1% by mass or more, still more preferably 0.2% by mass or more, and preferably 5.0% by mass or less, more preferably 4.0% by mass or less, still more preferably 3.5% by mass or less, and still more preferably 2.5% by mass or less.

[0114] <<pH value>>

[0115] From the viewpoint of being able to impart a hair shape with sufficient wash resistance and enabling the hair to obtain good elasticity, toughness, and neatness, the pH value of the agent B1 is 8 to 11, and more preferably 8.5 to 10.5.

[0116] The pH value is a value measured at 25° C., and can be specifically measured by the method described in the Examples.

[0117] In addition to components (b1), (b2) and (b3), agent B1 may also contain ingredients commonly used in cosmetic compositions, for example: aqueous media such as water, lower alcohols, low molecular weight diols, and triols; surfactants such as higher alcohols, cationic surfactants, and nonionic surfactants; viscosity modifiers; silicones; aromatic alcohols; polymers; oils; anti-dandruff agents; vitamins; bactericides; anti-inflammatory agents; preservatives; chelating agents; moisturizers; pearlescent agents; ceramides; fragrances; ultraviolet absorbers, etc.

[0118] The dosage form of Agent B1 is not particularly limited and may be in any form, such as liquid, foam, paste, cream, solid, or powder. From the perspective of application to hair by coating, dipping, etc., Agent B1 is preferably in the form of a liquid, paste, or cream, more preferably a cream. From the perspective of improving the manageability of hair, a cream containing a cationic surfactant and a higher alcohol is even more preferred.

[0119] As the cationic surfactant, preferably one or more selected from monoalkyltrimethylammonium chloride, dialkyldimethylammonium chloride, monoalkoxyalkyltrimethylammonium chloride, and monoalkyltrimethylammonium bromide, preferably one or more selected from monoalkyltrimethylammonium chloride and monoalkoxyalkyltrimethylammonium chloride, among which more preferably one selected from behenyltrimethylammonium chloride, stearyltrimethylammonium chloride, cetyltrimethylammonium chloride, lauryltrimethylammonium chloride, dialkyl(C 12 ~C 18 ) one or more of dimethylammonium chloride and octadecyloxypropyltrimethylammonium chloride.

[0120] When the B1 agent contains a cationic surfactant, the content of the cationic surfactant in the B1 agent is preferably 0.1% by mass or more, more preferably 0.5% by mass or more, further preferably 1.0% by mass or more, and further more preferably 2.0% by mass or more, and is preferably 10% by mass or less, more preferably 5% by mass or less, and further preferably 4% by mass or less.

[0121] As the higher alcohol, the general formula R 4 -OH (where R 4 A higher alcohol represented by a linear or branched hydrocarbon group having 12 or more and 24 or less carbon atoms. 4Preferably, it is a straight-chain or branched aliphatic hydrocarbon group having 12 or more and 24 or less carbon atoms, more preferably a straight-chain or branched alkyl group having 12 or more and 24 or less carbon atoms, or a straight-chain or branched alkenyl group having 12 or more and 24 or less carbon atoms, further preferably a straight-chain alkyl group having 12 or more and 24 or less carbon atoms, or a straight-chain alkenyl group having 12 or more and 24 or less carbon atoms.

[0122] Examples of the higher alcohol include lauryl alcohol, myristyl alcohol, cetyl alcohol, stearyl alcohol, isostearyl alcohol, arachidyl alcohol, behenyl alcohol, lignoceryl alcohol, and oleyl alcohol. One or more alcohols selected from these alcohols may be used in combination.

[0123] When the B1 agent contains a higher alcohol, its content is preferably 2 mass% or more, more preferably 3 mass% or more, further preferably 4 mass% or more, and is preferably 10 mass% or less, more preferably 8 mass% or less, further preferably 7 mass% or less, and further more preferably 6 mass% or less.

[0124] Furthermore, from the viewpoint of the stability of the preparation, it is preferred to contain a nonionic surfactant.

[0125] As the nonionic surfactant, a polyoxyethylene addition type nonionic surfactant can be used.

[0126] Specific examples of polyoxyethylene addition-type nonionic surfactants include polyoxyethylene alkyl ethers, polyoxyethylene alkenyl ethers, polyoxyethylene monofatty acid esters, and polyoxyethylene sorbitan fatty acid esters. The alkyl and alkenyl groups in these may be straight or branched chains. Furthermore, the aliphatic chain in the fatty acid may be saturated or unsaturated, and may be straight or branched chains.

[0127] From the viewpoint of suppressing the formation of agglomerates, the number of carbon atoms in the aliphatic chain in the above-mentioned alkyl groups, alkenyl groups, and fatty acids is preferably 8 or more, more preferably 10 or more, and further preferably 12 or more. In addition, it is preferably 22 or less, more preferably 20 or less, and further preferably 18 or less.

[0128] When the B1 agent contains a nonionic surfactant, the content of the nonionic surfactant in the B1 agent is preferably 0.05 mass% or more, more preferably 0.3 mass% or more, further preferably 0.5 mass% or more, further more preferably 0.7 mass% or more, and is preferably 10 mass% or less, more preferably 7 mass% or less, further preferably 5.0 mass% or less, further more preferably 3.0 mass% or less.

[0129] The preparation method of Agent B1 is not particularly limited and can be prepared, for example, by blending Component (b1), Component (b2), and other components as needed, and mixing them using a known stirring apparatus or the like.

[0130] (Apply B1 to hair)

[0131] The hair may be in a dry or wet state when applying Agent B1, but is preferably in a wet state from the viewpoint of imparting a shape with sufficient shampoo resistance to the hair and providing good elasticity, firmness, and manageability to the hair.

[0132] The method of applying Agent B1 to the hair may be any method that allows Agent B1 to come into contact with the hair, and the above-mentioned method of applying Agent A to the hair may be employed.

[0133] From the perspective of achieving a balance between imparting a hair shape with sufficient shampoo resistance and economic efficiency, the amount of Agent B1 applied to the hair is preferably 1:0.1 to 1:20, more preferably 1:0.3 to 1:10, and even more preferably 1:0.5 to 1:5, in terms of bath ratio (dry mass of hair: mass of Agent B1).

[0134] When the agent B1 is applied to the hair, the ratio of the treatment amount of the reducing agent (a1) to the melanin precursor (b1) per unit dry mass of the hair [(a1) / (b1)] is preferably 45 or more, more preferably 80 or more, and even more preferably 150 or more, from the viewpoint of not changing the hair color. From the viewpoint of maintaining a neat feel, elasticity, and not changing the hair color, it is preferably 460 or less, more preferably 300 or less, and even more preferably 200 or less. Furthermore, it is preferably 45 to 460, more preferably 80 to 300, and even more preferably 150 to 200.

[0135] In this method, since Agent A1 and Agent B1 are applied to the hair in separate steps, the treatment amount ratio of component (a1) to component (b1) is determined by the content of component (a1) in Agent A1, the content of component (b1) in Agent B1, and the respective application amounts of Agent A1 and Agent B1 to the hair, and can be easily adjusted.

[0136] The time for applying Agent B1 to the hair, that is, the total time for applying or impregnating the hair with Agent B1 and the time the hair is left standing, can be varied as appropriate. From the perspective of allowing the components of Agent B1 to penetrate the hair, it is preferably 1 minute or longer, more preferably 3 minutes or longer, and even more preferably 4 minutes or longer. From the perspective of reducing the burden on the operator, it is preferably 60 minutes or shorter, more preferably 30 minutes or shorter, and even more preferably 15 minutes or shorter. From this perspective, the time for applying Agent B1 to the hair is preferably 1 to 60 minutes, more preferably 3 to 30 minutes, and even more preferably 4 to 15 minutes.

[0137] From the viewpoint of removing the components of the B1 agent that have not penetrated into the hair, the method of the present invention preferably includes a rinsing step of rinsing the hair after applying the B1 agent to the hair and before the following step 2.

[0138] Furthermore, the method of the present invention may suitably include a hair drying step (hereinafter also referred to as the "drying step") after the rinsing step. The hair drying step is a step for reducing the moisture content of the hair. To actively reduce the moisture content of the hair, this step may include, for example, one or more drying treatments selected from the group consisting of towel drying, hair dryer drying (with cold air or hot air), and air drying. Preferably, a combination of two or more of these drying treatments is performed.

[0139] <Step of Shaping Hair: Step 2>

[0140] The method of the present invention further comprises the step of imparting a shape to the hair (step 2). The shape imparted to the hair may be straight or curly, but is preferably straight.

[0141] Examples of methods for shaping the hair include: a method of giving a straight shape to the hair by combing the hair with a comb; a method of straightening the hair by holding a hair iron and sliding the hair from the roots to the tips thereof; and a method of giving a curly shape to the hair by holding and curling the hair with a hair iron.

[0142] Step 2 is preferably a step of drying the hair and heating the hair with a hair iron to give the hair a shape. Drying the hair in this step is performed after step 1 and before step 2 when the hair has not yet dried. If the drying step has already been performed in step 1, this step can be omitted.

[0143] In the above step 2, the method for drying the hair is not particularly limited, and the hair may be dried using a hair dryer or the like.

[0144] From the perspective of imparting a shape with sufficient shampoo resistance to the hair and achieving good elasticity, firmness, and a manageable feel to the hair, the heating temperature of the hair using a hair iron is preferably 100°C or higher, more preferably 120°C or higher, and even more preferably 140°C or higher. Furthermore, from the perspective of suppressing hair damage, the heating temperature is preferably 220°C or lower, and even more preferably 210°C or lower. From this perspective, the heating temperature of the hair is preferably 100-220°C, more preferably 120-220°C, and even more preferably 140-210°C.

[0145] <Step of applying agent C to hair: Step 3>

[0146] (Drug C)

[0147] Agent C contains an oxidizing agent. Examples of the oxidizing agent include potassium bromate, sodium bromate, sodium perborate, and hydrogen peroxide. These can be used alone or in combination of two or more. From the perspective of imparting a shape with sufficient shampoo resistance to hair and achieving good elasticity, toughness, and a manageable feel to the hair, the oxidizing agent preferably comprises one or more selected from sodium bromate and hydrogen peroxide, and more preferably sodium bromate.

[0148] From the viewpoint of sufficiently re-bonding the disulfide bonds of keratin constituting hair, the content of the oxidizing agent in Agent C is preferably 1 to 20% by mass, more preferably 2 to 10% by mass, and even more preferably 3 to 8% by mass.

[0149] In addition to the oxidizing agent, Agent C may also contain ingredients commonly used in cosmetic compositions, such as: aqueous media such as lower alcohols, low molecular weight diols, and triols; pH regulators; surfactants; viscosity regulators; silicones; aromatic alcohols; polymers; oils; anti-dandruff agents; vitamins; bactericides; anti-inflammatory agents; preservatives; chelating agents; moisturizers; pearlescent agents; ceramides; fragrances; ultraviolet absorbers, etc.

[0150] The agent C preferably contains an oxidizing agent and, if necessary, components generally used in cosmetic compositions, with the remainder being water.

[0151] The method for preparing Agent C is not particularly limited, and it can be prepared, for example, by blending an oxidizing agent, water, and other components as needed, and mixing them using a known stirring apparatus or the like.

[0152] (Apply Agent C to hair)

[0153] The hair can be applied with Agent C in either a dry or wet state. However, the dry state is preferred from the perspective of imparting a shape with sufficient shampoo resistance, and providing good elasticity, firmness, and a manageable feel to the hair. Application of Agent C to the hair is preferably performed after Step 2.

[0154] The method of applying Agent C to the hair may be any method that allows Agent C to come into contact with the hair, and the above-mentioned method of applying Agent A to the hair may be employed.

[0155] From the perspective of achieving a balance between imparting a hair shape with sufficient shampoo resistance and economic efficiency, the amount of Agent C applied to the hair is preferably 1:0.1 to 1:20, more preferably 1:0.5 to 1:10, and even more preferably 1:1 to 1:5, in terms of bath ratio (dry mass of hair: mass of Agent C).

[0156] The time during which Agent C is applied to the hair, that is, the total time during which Agent C is applied to or immersed in the hair and the time the hair is left to stand, can be varied as appropriate. From the perspective of allowing the components of Agent C to penetrate the hair, it is preferably 3 minutes or longer, more preferably 5 minutes or longer, and even more preferably 10 minutes or longer. From the perspective of reducing the burden on the operator, it is preferably 90 minutes or shorter, more preferably 60 minutes or shorter, even more preferably 45 minutes or shorter, and even more preferably 30 minutes or shorter. From this perspective, the time during which Agent C is applied to the hair is preferably 3 to 90 minutes, more preferably 5 to 60 minutes, even more preferably 10 to 45 minutes, and even more preferably 10 to 30 minutes.

[0157] <Hair Rinsing Step: Step 4>

[0158] From the viewpoint of removing the components of Agent C that have not penetrated into the hair, the method of the present invention includes, as Step 4, a step of rinsing the hair after applying Agent C to the hair.

[0159] The method of rinsing the hair is not particularly limited, and for example, the hair can be rinsed with water.

[0160] The method of the present invention imparts shape to the hair after application of Agent A or Agent B1, and after application of Agent C, the imparted shape to the hair is maintained even after rinsing, thereby imparting a shape to the hair that is sufficiently resistant to shampooing.

[0161] The method of the present invention can impart a straight or curly shape to hair by applying Agent A and Agent B1 to the hair and heating it with a hair iron. Furthermore, by applying Agent C to the hair, the shape imparted to the hair treated by the method of the present invention is maintained, resulting in sufficient shampoo resistance, no change in hair color, and excellent manageability without compromising hair elasticity or toughness.

[0162] [Hair styling kit]

[0163] The present invention also provides a hair styling kit comprising:

[0164] Agent A1 contains the following ingredient (a1) and has a pH value of 8 to 11.

[0165] (a1) reducing agent;

[0166] Agent B1, which contains the following components (b1) and (b2) and has a pH value of 8 to 11; and Agent C, which contains an oxidizing agent,

[0167] (b1) 0.03 to 0.3% by mass of a compound represented by the following general formula (1) or a salt thereof;

[0168]

[0169] (where the dashed line indicates the presence or absence of a π bond, R 1 represents a hydroxyl group or an acetoxy group, R 2 represents a hydrogen atom or -COOR (R represents a hydrogen atom, a methyl group or an ethyl group), R 3 represents a hydrogen atom, an acetyl group, a methyl group, or an ethyl group.)

[0170] (b2) Alkali agent.

[0171] Agent A1, Agent B1, Agent C and preferred embodiments thereof are the same as those described in the hair styling method.

[0172] The present invention also provides a hair styling kit comprising:

[0173] Agent A2, which contains the following ingredients (a1) and (a2) and has a pH of 8 to 11; and

[0174] Agent C, which contains an oxidizing agent,

[0175] (a1) reducing agent;

[0176] (a2) 0.03 to 0.3% by mass of a compound represented by the following general formula (1) or a salt thereof.

[0177]

[0178] (where the dashed line indicates the presence or absence of a π bond, R 1 represents a hydroxyl group or an acetoxy group, R 2 represents a hydrogen atom or -COOR (R represents a hydrogen atom, a methyl group or an ethyl group), R 3 represents a hydrogen atom, an acetyl group, a methyl group, or an ethyl group.)

[0179] Agent A2 and Agent C and their preferred embodiments are the same as those described in the hair styling method.

[0180] Hereinafter, the present invention further discloses the following contents with respect to the above-mentioned embodiment.

[0181] <1>

[0182] A method for imparting a hair shape, comprising:

[0183] Step 1A: a step of applying Agent A1 to the hair and then applying Agent B1 to the hair; or Step 1B: a step of applying Agent A2 to the hair; and

[0184] Step 2: The step of giving shape to the hair.

[0185] Further in sequence:

[0186] Step 3: a step of applying agent C containing an oxidizing agent to the hair; and

[0187] Step 4: Rinse the hair.

[0188] The A1 agent contains the following ingredient (a1) and has a pH value of 8 to 11.

[0189] (a1) a reducing agent,

[0190] The B1 agent contains the following components (b1) and (b2), and has a pH value of 8 to 11.

[0191] (b1) a compound represented by the following general formula (1) or a salt thereof, wherein the content thereof is 0.03 to 0.3% by mass;

[0192]

[0193] (where the dashed line indicates the presence or absence of a π bond, R 1 represents a hydroxyl group or an acetoxy group, R 2 represents a hydrogen atom or -COOR (R represents a hydrogen atom, a methyl group or an ethyl group), R 3 represents a hydrogen atom, an acetyl group, a methyl group, or an ethyl group.)

[0194] (b2) alkali agents,

[0195] The A2 agent contains the following ingredients (a1) and (a2), and has a pH value of 8 to 11.

[0196] (a1) reducing agent;

[0197] (a2) A compound represented by the following general formula (1) or a salt thereof, wherein the content thereof is 0.03 to 0.3% by mass.

[0198]

[0199] (where the dashed line indicates the presence or absence of a π bond, R 1 represents a hydroxyl group or an acetoxy group, R 2 represents a hydrogen atom or -COOR (R represents a hydrogen atom, a methyl group or an ethyl group), R 3 represents a hydrogen atom, an acetyl group, a methyl group, or an ethyl group.)

[0200] <2>

[0201] like <1> The method for imparting a shape to hair, wherein the component (a1) comprises one or more selected from thioglycolic acid and its derivatives, thiolactic acid and its derivatives, cysteine ​​and its derivatives, and salts thereof.

[0202] <3>

[0203] like <1> or <2> A method for imparting hair shape, wherein the component (a1) comprises one or more selected from thioglycolic acid, ammonium thioglycolate, glyceryl thioglycolate, L-cysteine, D-cysteine, N-acetylcysteine, ammonium salts of these cysteines, ethanolamine salts, thioglyceryl alkyl ethers, mercaptoethylpropionamide, and mercaptoethylglucamide, preferably comprises one or more selected from thioglycolic acid, ammonium thioglycolate, glyceryl thioglycolate, L-cysteine, D-cysteine, N-acetylcysteine, and ammonium salts of these cysteines, more preferably comprises one or more selected from thioglycolic acid, ammonium thioglycolate, and glyceryl thioglycolate.

[0204] <4>

[0205] like <1> to <3> The method for imparting hair style according to any one of the above, wherein the content of the reducing agent (component (a1)) in the agent A1 or the agent A2 is preferably 0.1 to 40% by mass, more preferably 1 to 20% by mass, even more preferably 2 to 15% by mass, and even more preferably 5 to 10% by mass.

[0206] <5>

[0207] like <1> to <4> The method for imparting hair shape according to any one of the preceding claims, wherein the component (a2) or the component (b1) is selected from 5,6-dihydroxyindole, 5,6-dihydroxyindole-2-carboxylic acid, 5,6-dihydroxyindole-2-carboxylic acid methyl ester, 5,6-dihydroxyindole-2-carboxylic acid ethyl ester, N-methyl-5,6-dihydroxyindole, N-methyl-5,6-dihydroxyindole-2-carboxylic acid, N-ethyl-5,6-dihydroxyindole, N-ethyl-5,6-dihydroxyindole-2-carboxylic acid, N-acetyl-5,6-dihydroxyindole, N-acetyl-5,6-dihydroxyindole-2-carboxylic acid, 5-acetoxy-6-hydroxyindole, 5-acetoxy-6-hydroxyindole-2-carboxylic acid, 5,6-dihydroxyindoline, 5,6-dihydroxyindole. Indoline-2-carboxylic acid, methyl 5,6-dihydroxyindoline-2-carboxylate, ethyl 5,6-dihydroxyindoline-2-carboxylate, N-methyl-5,6-dihydroxyindoline, N-methyl-5,6-dihydroxyindoline-2-carboxylic acid, N-ethyl-5,6-dihydroxyindoline, N-ethyl-5,6-dihydroxyindoline-2-carboxylic acid, N-acetyl-5,6-dihydroxyindoline, N-acetyl-5,6-dihydroxyindoline-2-carboxylic acid, 5-acetoxy-6-hydroxyindoline, and 5-acetoxy-6-hydroxyindoline-2-carboxylic acid; and at least one of the hydrochloride, hydrobromide, sulfate, phosphate, acetate, propionate, lactate, and citrate of these compounds, preferably the hydrobromide of these compounds.

[0208] <6>

[0209] like <1> to <5> The method for imparting hair style according to any one of the above, wherein the component (a2) or the component (b1) preferably comprises one or more selected from 5,6-dihydroxyindole, 5,6-dihydroxyindoline, 5,6-dihydroxyindoline-2-carboxylic acid, and salts thereof, more preferably comprises one or more selected from 5,6-dihydroxyindole, 5,6-dihydroxyindoline, 5,6-dihydroxyindole-2-carboxylic acid, and 5,6-dihydroxyindoline hydrobromide, further preferably comprises one or more selected from 5,6-dihydroxyindole and 5,6-dihydroxyindole-2-carboxylic acid, and even more preferably comprises a mixture of 5,6-dihydroxyindole and 5,6-dihydroxyindole-2-carboxylic acid.

[0210] <7>

[0211] like <1> to <6> The method for imparting a shape to hair according to any one of the above, wherein R in the general formula (1) of the component (a2) or the component (b1) is 2 When -COOH is present, the salt of the compound represented by the general formula (1) is its carboxylate (R 2 -COO - X + (X + is a cation)).

[0212] <8>

[0213] like <1> to <7> The method for imparting hair style according to any one of the above, wherein, when the component (a2) or the component (b1) contains 5,6-dihydroxyindole and 5,6-dihydroxyindole-2-carboxylic acid, the molar ratio of the 5,6-dihydroxyindole to the 5,6-dihydroxyindole-2-carboxylic acid is preferably in the range of 50:50 to 99:1, more preferably in the range of 80:20 to 99:1, and even more preferably in the range of 85:15 to 95:5.

[0214] <9>

[0215] like <1> to <8> The method for imparting hair styling according to any one of the above, wherein the content of the component (a2) in the agent A2 or the component (b1) in the agent B1 is 0.03 to 0.3% by mass, preferably 0.05 to 0.25% by mass, more preferably 0.055 to 0.2% by mass, further preferably 0.06 to 0.15% by mass, and even more preferably 0.065 to 0.1% by mass.

[0216] <10>

[0217] like <1> to <9> The hair styling method according to any one of the preceding claims, wherein in the step 1A, the ratio of the treatment amounts of the component (a1) to the component (b1) per unit dry weight of hair [(a1) / (b1)] is preferably 45 or more, more preferably 80 or more, even more preferably 150 or more, preferably 460 or less, more preferably 300 or less, even more preferably 200 or less, and preferably 45 to 460, more preferably 80 to 300, even more preferably 150 to 200; or in the step 1B, the ratio of the treatment amounts of the component (a1) to the component (a2) per unit dry weight of hair [(a1) / (a2)] is preferably 20 or more, more preferably 65 or more, even more preferably 80 or more, preferably 250 or less, more preferably 150 or less, even more preferably 100 or less, and preferably 25 to 250, more preferably 65 to 150, even more preferably 80 to 100.

[0218] <11>

[0219] like <1> to <10> The method for imparting hair style according to any one of the above, wherein the pH value of the agent A1 or the agent A2 at 25°C is 8 to 11, preferably 8.5 to 10.5.

[0220] <12>

[0221] like <1> to <11> The method for imparting hair style according to any one of the above, wherein the agent A1 or the agent A2 contains, in addition to the reducing agent and the compound represented by the general formula (1), at least one selected from the group consisting of an aqueous medium, a pH adjuster, a surfactant, an antioxidant, a viscosity adjuster, silicone, an aromatic alcohol, a coloring component other than the component (a2), a polymer, an oil, an antidandruff agent, a vitamin, a bactericide, an anti-inflammatory agent, a preservative, a chelating agent, a moisturizer, a pearlescent agent, a ceramide, a fragrance, and an ultraviolet absorber.

[0222] <13>

[0223] like <1> to <12> The method for imparting hair style according to any one of the above, wherein the formulation of the agent A1 or the agent A2 is liquid, foam, paste, cream, solid, or powder, preferably liquid, paste, or cream.

[0224] <14>

[0225] like <1> to <13> The method for imparting a style to hair according to any one of the above, wherein the hair is in a dry state or a wet state when the agent A1 or the agent A2 is applied.

[0226] <15>

[0227] like <1> to <14> The method for imparting hair style according to any one of the above, wherein the hair is wet with water when the agent A1 or the agent A2 is applied, and the bath ratio (dry mass of hair:mass of water) is preferably 1:0.1 to 1:10, more preferably 1:0.2 to 1:5, and even more preferably 1:0.3 to 1:3.

[0228] <16>

[0229] like <1> to <15> The method for imparting a shape to hair according to any one of the above, wherein the method of applying the agent A1 or the agent A2 to the hair is a method of bringing the agent A1 or the agent A2 into contact with the hair, preferably a method of applying the agent A1 or the agent A2 to the hair or a method of immersing the hair in the agent A1 or the agent A2.

[0230] <17>

[0231] like <1> to <16> The method for imparting hair shape according to any one of the above, wherein the amount of the agent A1 or the agent A2 applied to the hair is preferably 1:0.2 to 1:20, more preferably 1:0.5 to 1:10, and even more preferably 1:1 to 1:5, in terms of bath ratio (dry mass of hair: mass of the agent A1 or the agent A2).

[0232] <18>

[0233] like <1> to <17> The hair styling method according to any one of claims , wherein the time for applying the agent A1 or the agent A2 to the hair is preferably 3 to 90 minutes, more preferably 5 to 60 minutes, further preferably 10 to 45 minutes, and even more preferably 10 to 30 minutes.

[0234] <19>

[0235] like <1> to <18> The method for imparting hair style according to any one of the above, wherein the temperature when applying the agent A1 or the agent A2 to the hair is preferably 20 to 40°C, more preferably 25 to 35°C.

[0236] <20>

[0237] like <1> to <19> The hair styling method according to any one of the above, further comprising the step of rinsing the hair after applying the agent A1 or the agent A2 to the hair and before applying the agent B1 or the step 2.

[0238] <21>

[0239] like <1> to <20> The method for imparting hair style according to any one of claims 1 to 4, wherein the component (b2) is one or more selected from ammonia, alkanolamines, alkylamines, arylalkylamines, and inorganic base compounds, and the number of carbon atoms in the alkanolamines, alkylamines, or arylalkylamines is preferably 10 or less, more preferably 8 or less.

[0240] <22>

[0241] like <1> to <21> The method for imparting a style to hair according to any one of claims 1 to 5, wherein the component (b2) comprises at least one selected from the group consisting of ammonia, alkanolamines, alkylamines, arylalkylamines, sodium hydroxide, potassium hydroxide, sodium carbonate, sodium bicarbonate, ammonium carbonate, and ammonium bicarbonate.

[0242] <23>

[0243] like <1> to <22> The method for imparting hair style according to any one of the above, wherein the content of the component (b2) in the agent B1 is preferably 0.1 to 10% by mass, more preferably 0.5 to 8% by mass, and even more preferably 1 to 5% by mass.

[0244] <24>

[0245] like <1> to <23> The method for imparting hair style according to any one of the above, wherein the agent B1 further contains a component (b3) an antioxidant.

[0246] <25>

[0247] like <24> A method for imparting a shape to hair, wherein the component (b3) comprises at least one selected from sulfurous acid, pyrosulfous acid, hydrogensulfite, sulfur dioxide, L-ascorbic acid, thioglycolic acid, L-cysteine, N-acetyl-L-cysteine, salts thereof, and derivatives thereof, preferably comprises at least one selected from L-ascorbic acid, sulfurous acid, pyrosulfous acid, hydrogensulfite, salts thereof, ascorbyl glucoside, and sulfur dioxide, more preferably comprises at least one selected from L-ascorbic acid, sodium sulfite, and sodium ascorbate, and even more preferably comprises at least one selected from L-ascorbic acid and sodium ascorbate.

[0248] <26>

[0249] like <24> or <25> The method for imparting hair shape, wherein the content of the component (b3) in the agent B1 is preferably 0.05 to 10% by mass, more preferably 0.1 to 5% by mass, and further preferably 0.3 to 2% by mass.

[0250] <27>

[0251] like <1> to <26> The method for imparting hair style according to any one of the above, wherein the pH value of the agent B1 at 25°C is 8 to 11, more preferably 8.5 to 10.5.

[0252] <28>

[0253] like <1> to <27> The method for imparting hair shape according to any one of the above, wherein the agent B1 further contains a pH adjuster. Preferably, the pH adjuster is one or more protonating agents selected from monobasic acids and polybasic acids, or one or more protonating agents selected from organic acids (having 1 to 8 carbon atoms, excluding ascorbic acid) and inorganic acids. More preferably, the protonating agent is one or more selected from hydrochloric acid, sulfuric acid, phosphoric acid, formic acid, acetic acid, and citric acid, and even more preferably one or more selected from phosphoric acid and citric acid.

[0254] <29>

[0255] like <28> The method for imparting hair shape, wherein the content of the pH adjuster in the agent B1 is preferably 0.05% by mass or more, more preferably 0.1% by mass or more, even more preferably 0.2% by mass or more, and is preferably 5.0% by mass or less, more preferably 4.0% by mass or less, even more preferably 3.5% by mass or less, and even more preferably 2.5% by mass or less.

[0256] <30>

[0257] like <1> to <29> The method for imparting a style to hair according to any one of the above, wherein the agent B1 further contains at least one selected from the group consisting of an aqueous medium, a higher alcohol, a surfactant, a viscosity modifier, silicone, an aromatic alcohol, a polymer, an oil, an antidandruff agent, a vitamin, a bactericide, an anti-inflammatory agent, a preservative, a chelating agent, a moisturizer, a pearlescent agent, a ceramide, a fragrance, and a UV absorber.

[0258] <31>

[0259] like <30> The method for imparting hair shape according to any one of the above, wherein the surfactant comprises a cationic surfactant, and the cationic surfactant preferably comprises one or more selected from the group consisting of monoalkyltrimethylammonium chloride, dialkyldimethylammonium chloride, monoalkoxyalkyltrimethylammonium chloride, and monoalkyltrimethylammonium bromide, and more preferably comprises one or more selected from the group consisting of monoalkyltrimethylammonium chloride and monoalkoxyalkyltrimethylammonium chloride, wherein the cationic surfactant comprises one or more selected from the group consisting of behenyltrimethylammonium chloride, stearyltrimethylammonium chloride, cetyltrimethylammonium chloride, lauryltrimethylammonium chloride, dialkyl(C 12 ~C 18 ) one or more of dimethylammonium chloride and octadecyloxypropyltrimethylammonium chloride.

[0260] <32>

[0261] like <30> or <31> The method for imparting hair shape, wherein the content of the cationic surfactant in the agent B1 is preferably 0.1% by mass or more, more preferably 0.5% by mass or more, even more preferably 1.0% by mass or more, and even more preferably 2.0% by mass or more, and is preferably 10% by mass or less, more preferably 5% by mass or less, and even more preferably 4% by mass or less.

[0262] <33>

[0263] like <30> to <32> The method for imparting hair shape according to any one of claims 1 to 6, wherein the higher alcohol is a compound of the general formula R 4 -OH (where R 4 represents a linear or branched hydrocarbon group having 12 or more and 24 or less carbon atoms), wherein R 4 It preferably contains a straight-chain or branched aliphatic hydrocarbon group having 12 or more and 24 or less carbon atoms, more preferably contains a straight-chain or branched alkyl group having 12 or more and 24 or less carbon atoms, or a straight-chain or branched alkenyl group having 12 or more and 24 or less carbon atoms, and further preferably contains a straight-chain alkyl group having 12 or more and 24 or less carbon atoms, or a straight-chain alkenyl group having 12 or more and 24 or less carbon atoms.

[0264] <34>

[0265] like <30> to <33> The method for imparting hair style according to any one of the above, wherein the higher alcohol is at least one selected from the group consisting of lauryl alcohol, myristyl alcohol, cetyl alcohol, stearyl alcohol, isostearyl alcohol, arachidyl alcohol, behenyl alcohol, lignoceryl alcohol, and oleyl alcohol.

[0266] <35>

[0267] like <30> to <34> The hair styling method according to any one of claims 1 to 4, wherein the agent B1 contains the higher alcohol, and the content of the higher alcohol in the agent B1 is preferably 2% by mass or more, more preferably 3% by mass or more, even more preferably 4% by mass or more, and is preferably 10% by mass or less, more preferably 8% by mass or less, even more preferably 7% by mass or less, and even more preferably 6% by mass or less.

[0268] <36>

[0269] like <30> to <35> The method for imparting a style to hair according to any one of the above, wherein the agent B1 further contains a nonionic surfactant, preferably a polyoxyethylene addition type nonionic surfactant.

[0270] <37>

[0271] like <36> A method for imparting a shape to hair, wherein the polyoxyethylene addition-type nonionic surfactant comprises one or more selected from polyoxyethylene alkyl ethers, polyoxyethylene alkenyl ethers, polyoxyethylene monofatty acid esters, and polyoxyethylene sorbitan fatty acid esters; preferably, the alkyl and alkenyl groups are linear or branched, and the aliphatic chain in the fatty acid is saturated or unsaturated and is linear or branched.

[0272] <38>

[0273] like <37> The method for imparting hair shape, wherein the number of carbon atoms in the alkyl group, the alkenyl group and the aliphatic chain is preferably 8 or more, more preferably 10 or more, and even more preferably 12 or more, and is preferably 22 or less, more preferably 20 or less, and even more preferably 18 or less.

[0274] <39>

[0275] like <36> to <38> The hair styling method according to any one of the above, wherein the content of the nonionic surfactant in the agent B1 is preferably 0.05% by mass or more, more preferably 0.3% by mass or more, even more preferably 0.5% by mass or more, and still more preferably 0.7% by mass or more, and is preferably 10% by mass or less, more preferably 7% by mass or less, even more preferably 5.0% by mass or less, and still more preferably 3.0% or less.

[0276] <40>

[0277] like <1> to <39> The method for imparting hair style according to any one of the above, wherein the dosage form of the agent B1 is liquid, foam, paste, cream, solid, or powder, preferably liquid, paste, or cream.

[0278] <41>

[0279] like <1> to <40> The method for imparting a style to hair according to any one of claims 1 to 5, wherein the hair is in a dry state or a wet state when the agent B1 is applied.

[0280] <42>

[0281] like <1> to <41> The method for imparting hair style according to any one of the above, wherein the method of applying the agent B1 to the hair is a method of bringing the agent B1 into contact with the hair, preferably a method of applying the agent B1 to the hair or a method of immersing the hair in the agent B1.

[0282] <43>

[0283] like <1> to <42> The method for imparting hair style according to any one of the above, wherein the amount of the agent B1 applied to the hair is preferably 1:0.1 to 1:20, more preferably 1:0.3 to 1:10, and even more preferably 1:0.5 to 1:5, in terms of bath ratio (dry mass of hair:mass of agent B1).

[0284] <44>

[0285] like <1> to <43> The hair styling method according to any one of the above, wherein the time for applying the agent B1 to the hair is preferably 1 to 60 minutes, more preferably 3 to 30 minutes, and even more preferably 4 to 15 minutes.

[0286] <45>

[0287] like <1> to <44> The method for imparting hair style according to any one of the above methods further comprises the step of rinsing the hair after applying the agent B1 to the hair and before the step 2.

[0288] <46>

[0289] like <45> A method for imparting a style to hair, wherein, after the step of rinsing the hair, there is a drying step of drying the hair, preferably one or more drying treatments selected from the group consisting of towel drying, hair dryer drying (with cold air or hot air), and air drying, and more preferably a combination of two or more drying treatments.

[0290] <47>

[0291] like <1> to <46> The hair styling method according to any one of claims 1 to 5, wherein the step 2 is a step of drying the hair and heating the hair with a hair iron to give the hair a shape.

[0292] <48>

[0293] like <47> The method for imparting a shape to hair, wherein the heating temperature using the hair iron is preferably 100 to 220°C, more preferably 120 to 220°C, and further preferably 140 to 210°C.

[0294] <49>

[0295] like <1> to <48> The hair styling method according to any one of claims 1 to 4, wherein the oxidizing agent comprises one or more selected from potassium bromate, sodium bromate, sodium perborate, and hydrogen peroxide, preferably comprises one or more selected from sodium bromate and hydrogen peroxide, and more preferably sodium bromate or hydrogen peroxide.

[0296] <50>

[0297] like <1> to <49> In any one of the methods for imparting hair style, the content of the oxidizing agent is preferably 1 to 20% by mass, more preferably 2 to 10% by mass, and even more preferably 3 to 8% by mass.

[0298] <51>

[0299] like <1> to <50> The method for imparting a style to hair according to any one of the preceding claims, wherein the agent C further contains, in addition to the oxidizing agent, one or more selected from the group consisting of an aqueous medium, a pH adjuster, a surfactant, a viscosity adjuster, silicone, an aromatic alcohol, a polymer, an oil, an antidandruff agent, a vitamin, a bactericide, an anti-inflammatory agent, a preservative, a chelating agent, a moisturizer, a pearlescent agent, a ceramide, a fragrance, and a UV absorber.

[0300] <52>

[0301] like <1> to <51> The method for imparting a style to hair according to any one of the above, wherein the hair is in a dry state or a wet state when the agent C is applied.

[0302] <53>

[0303] like <1> to <52> The method for imparting a style to hair according to any one of the above, wherein the method of applying the agent C to the hair is a method of bringing the agent C into contact with the hair, preferably a method of applying the agent C to the hair or a method of immersing the hair in the agent C.

[0304] <54>

[0305] like <1> to <53> The method for imparting hair style according to any one of claims , wherein the amount of the agent C applied to the hair is preferably 1:0.1 to 1:20, more preferably 1:0.5 to 1:10, and even more preferably 1:1 to 1:5, in terms of bath ratio (dry mass of hair:mass of agent C).

[0306] <55>

[0307] like <1> to <54> The method for imparting hair style according to any one of claims , wherein the agent C is applied to the hair for a time period of preferably 3 to 90 minutes, more preferably 5 to 60 minutes, further preferably 10 to 45 minutes, and even more preferably 10 to 30 minutes.

[0308] <56>

[0309] like <1> to <55> The hair styling method according to any one of the preceding claims, wherein the step 4 is a step of applying the agent C to the hair and then rinsing the hair with water.

[0310] <57>

[0311] like <1> to <56> The method for imparting a shape to hair according to any one of claims 1 to 5, wherein the shape imparted to the hair is a straight or curly shape.

[0312] <58>

[0313] A hair styling kit comprising:

[0314] Agent A1 contains the following ingredient (a1) and has a pH value of 8 to 11.

[0315] (a1) reducing agent;

[0316] Agent B1, which contains the following components (b1) and (b2) and has a pH value of 8 to 11; and Agent C, which contains an oxidizing agent,

[0317] (b1) 0.03 to 0.3% by mass of a compound represented by the following general formula (1) or a salt thereof;

[0318]

[0319] (where the dashed line indicates the presence or absence of a π bond, R 1 represents a hydroxyl group or an acetoxy group, R 2 represents a hydrogen atom or -COOR (R represents a hydrogen atom, a methyl group or an ethyl group), R 3 represents a hydrogen atom, an acetyl group, a methyl group, or an ethyl group.)

[0320] (b2) Alkali agent.

[0321] <59>

[0322] like <58> A hair styling kit, wherein the A1 agent has <2> to <4> and <11> to <13> Any one of the above structures.

[0323] <60>

[0324] like <58> or <59> The hair shaping kit, wherein the B1 agent has <5> to <10> and <21> to <40> Any one of the above structures.

[0325] <61>

[0326] like <58> to <60> The hair styling kit according to any one of claims 1 to 6, wherein the agent C has <49> to <51> Any one of the above structures.

[0327] <62>

[0328] A hair styling kit comprising:

[0329] Agent A2, which contains the following components (a1) and (a2) and has a pH value of 8 to 11; and

[0330] Agent C, which contains an oxidizing agent,

[0331] (a1) A reducing agent;

[0332] (a2) 0.03 to 0.3% by mass of a compound represented by the following general formula (1) or a salt thereof.

[0333]

[0334] (In the formula, the dotted line indicates the presence or absence of a π bond, R 1 represents a hydroxyl group or an acetoxy group, R 2 represents a hydrogen atom or -COOR (R represents a hydrogen atom, a methyl group or an ethyl group), R 3 represents a hydrogen atom, an acetyl group, a methyl group or an ethyl group.)

[0335] <63>

[0336] A hair shape imparting kit as described in <62>, wherein the Agent A2 has the constitution described in any one of <2> to <13>.

[0337] <64>

[0338] A hair shape imparting kit as described in <62> or <63>, wherein the Agent C has the constitution described in any one of <49> to <51>.

[0339] Examples

[0340] Hereinafter, the present invention will be described by way of examples, but the present invention is not limited to the scope of the examples. Furthermore, in this example, various measurements and evaluations are carried out by the following methods.

[0341] <pH value measurement>

[0342] Using a pH meter (F-51, manufactured by HORIBA Ltd.), the pH values of Agent A and Agent B1 at 25 °C were measured.

[0343] <Straightening>

[0344] Regarding the shape change of the hair bundle after the following hair treatment, the number of professional evaluators who evaluated as "straightening was achieved through the treatment" by 5 professional evaluators was used as the evaluation value. The higher the evaluation value, the more excellent the hair shape imparting effect can be evaluated.

[0345] <Smoothness>

[0346] Regarding the grooming of hair after the following hair treatments, five professional evaluators evaluated the grooming of hair strands treated under various conditions and dried, with the number of evaluators evaluating whether the hair flow was neat and uniform from the roots to the tips. A higher evaluation value indicates a more excellent grooming.

[0347] <Stretchy and resilient>

[0348] Regarding the elasticity of hair after the following hair treatments, five panelists evaluated the elasticity of hair tresses treated under various conditions and dried. The number of panelists who felt "elasticity compared to untreated hair tresses" upon touching the hair was used as the evaluation value. A higher evaluation value indicates that the elasticity is not impaired.

[0349] <Changes in L Value after Treatment>

[0350] In order to evaluate the change in brightness of the hair before and after the treatment, the L value of the hair tress was measured.

[0351] L values ​​were measured using a colorimeter (CR-400, Konica Minolta Inc.) for the lightness (L*) of hair tresses before and after the treatment described below. Six measurements were taken per strand of hair, and the average value was calculated. Smaller absolute changes in L values ​​indicate less change in hair color. L* refers to the lightness L* defined by the CIE 1976 L*a*b* color system.

[0352] <Appearance color and brightness>

[0353] Regarding changes in hair color and brightness after treatment, five panelists evaluated the color and brightness of dried hair tresses after the following treatments as "no change in color or brightness compared to untreated hair tresses." The higher the evaluation value, the less likely the hair color has changed.

[0354] <Shampooing resistance>

[0355] Regarding the shampoo resistance of treated hair, five panelists evaluated the shape change of the hair bundle after seven shampooings using the following hair treatment and the following standard shampoo. The number of panelists who rated the hair shape as "maintained even after shampooing" was used as the evaluation value. The higher the evaluation value, the more shampoo-resistant the imparted hair shape was.

[0356] <Preparation of Hair Bundles for Evaluation>

[0357] Using untreated Japanese black curly hair (not for sale), hair tresses were prepared. When a light load was applied to the hair and the hair was stretched straight, the length was 30-35 cm and the mass was 10-15 g. The tresses were washed and rinsed with a shampoo of the following formulation, and excess water was wiped off with a towel. The tresses were then air-dried for 12 hours under laboratory conditions. The dried tresses were then used for evaluation.

[0358]

[0359] <Hair Treatment>

[0360] Examples 1 to 5, Comparative Examples 1 to 2 (Preparation and Application of Agents A, B1, and C)

[0361] The components shown in Table 1 were blended according to the mixing ratios described in Table 1 and mixed until uniform, thereby preparing Agent A, Agent B1, and Agent C.

[0362] Agent A was applied to the hair tresses in the state shown in Table 1 at the bath ratio (hair dry mass: mass of Agent A) shown in Table 1, maintained for the time shown in Table 1, and rinsed. For the hair tresses other than Example 4 and Comparative Example 1, Agent B1 was applied to the hair tresses in the state shown in Table 1 at the bath ratio (hair dry mass: mass of Agent B1) shown in Table 1, maintained for the time shown in Table 1, and rinsed (Step 1A or Step 1B). The hair tresses, which had been dried with a hair dryer, were heated using a hair iron under the conditions shown in Table 1 to impart a straight shape (Step 2). Subsequently, Agent C was applied to the hair tresses at the bath ratio (hair dry mass: mass of Agent C) shown in Table 1, maintained for the time shown in Table 1 (Step 3), and rinsed (Step 4). The treated hair tresses were evaluated using the above-described method. The results are shown in Table 1.

[0363] In addition, the compounding amounts (mass %) described in Table 1 are all amounts of active ingredients, and the total of Agent A and Agent B1 is 100 mass %.

[0364] [Table 1]

[0365]

[0366] *6: The components described in the hair bundle in a state where the bath ratio (hair bundle:water) is 1:0.5 are as follows.

[0367] (a2) and (b1): A mixture of 5,6-dihydroxyindole and 5,6-dihydroxyindole-2-carboxylic acid: These were prepared according to the method described in Japanese Patent No. 5570161. The molar ratio of 5,6-dihydroxyindole to 5,6-dihydroxyindole-2-carboxylic acid was 90:10. Separately, a 1% by mass solution of (a2) and (b1) in a 4 / 1 (wt / wt) ratio of H2O / ethanol was prepared and added to Agent A or Agent B1.

[0368] *1: Quartamin 86W (stearyltrimethylammonium chloride, active ingredient content: 28% by mass, Kao Corporation)

[0369] *2: NIKKOL BC-40TX (Nikko Chemicals Co.,Ltd.)

[0370] *3: NIKKOL BC-2 (Nikko Chemicals Co., Ltd.)

[0371] *4: KALCOL 8098 (Kao Corporation)

[0372] *5: KALCOL 220-80 (Kao Corporation)

[0373] Note that Agent B1 of Example 5 is a liquid aqueous composition (aqueous agent) not containing a cationic surfactant and a higher alcohol.

[0374] As shown in Table 1, the method of the present invention can impart a shape to hair having sufficient shampoo resistance without changing the hair color, and can provide excellent manageability without impairing the elasticity and toughness of the hair.

[0375] Industrial applicability

[0376] According to the present invention, a method for styling hair can be provided which can impart sufficient shampoo resistance to the hair without changing the hair color, and which does not impair the elasticity and toughness of the hair and provides an excellent manageable feel.

Claims

1. A method for imparting a shape to hair, comprising: In order: Step 1A: a step of applying Agent A1 to the hair and then applying Agent B1 to the hair; or Step 1B: a step of applying Agent A2 to the hair; and Step 2: The step of giving shape to the hair. Further in sequence: Step 3: a step of applying agent C containing an oxidizing agent to the hair; and Step 4: Rinse the hair. The A1 agent contains the following ingredient (a1) and has a pH value of 8 to 11. (a1) a reducing agent, The B1 agent contains the following components (b1) and (b2), and has a pH value of 8 to 11. (b1) a compound represented by the following general formula (1) or a salt thereof, wherein the content thereof is 0.03 to 0.3% by mass. In the formula, the dotted line indicates the presence or absence of a π bond, and R 1 represents a hydroxyl group or an acetoxy group, R 2 represents a hydrogen atom or -COOR, wherein R represents a hydrogen atom, a methyl group or an ethyl group, and R 3 represents a hydrogen atom, an acetyl group, a methyl group or an ethyl group; (b2) alkali agents, The A2 agent contains the following ingredients (a1) and (a2), and has a pH value of 8 to 11. (a1) reducing agent; (a2) a compound represented by the following general formula (1) or a salt thereof, wherein the content thereof is 0.03 to 0.3% by mass. In the formula, the dotted line indicates the presence or absence of a π bond, and R 1 represents a hydroxyl group or an acetoxy group, R 2 represents a hydrogen atom or -COOR, wherein R represents a hydrogen atom, a methyl group or an ethyl group, and R 3 represents a hydrogen atom, an acetyl group, a methyl group or an ethyl group.

2. The method for imparting hair shape according to claim 1, wherein: The step 2 is a step of drying the hair and heating the hair with a hair iron to give the hair a shape.

3. The method for imparting hair shape according to claim 1 or 2, wherein: The shape imparted to the hair is straight or curly.

4. The method for imparting hair shape according to any one of claims 1 to 3, wherein The component (a1) comprises one or more selected from thioglycolic acid, ammonium thioglycolate, thioglycolic acid glyceride, L-cysteine, D-cysteine, N-acetylcysteine, and ammonium salts of these cysteines.

5. The method for imparting hair shape according to any one of claims 1 to 4, wherein The component (b2) includes at least one selected from ammonia, alkanolamines, alkylamines, arylalkylamines, sodium hydroxide, potassium hydroxide, sodium carbonate, sodium bicarbonate, ammonium carbonate, and ammonium bicarbonate.

6. The method for imparting hair style according to any one of claims 1 to 5, wherein The oxidant is sodium bromate or hydrogen peroxide.

7. A hair styling kit, wherein: have: Agent A1 contains the following ingredient (a1) and has a pH value of 8 to 11. (a1) reducing agent; Agent B1, which contains the following ingredients (b1) and (b2) and has a pH of 8 to 11; and Agent C, which contains an oxidizing agent, (b1) a compound represented by the following general formula (1) or a salt thereof, wherein the content thereof is 0.03 to 0.3% by mass. In the formula, the dotted line indicates the presence or absence of a π bond, and R 1 represents a hydroxyl group or an acetoxy group, R 2 represents a hydrogen atom or -COOR, wherein R represents a hydrogen atom, a methyl group or an ethyl group, and R 3 represents a hydrogen atom, an acetyl group, a methyl group or an ethyl group; (b2) Alkali agent.

8. A hair styling kit, wherein: have: Agent A2, which contains the following ingredients (a1) and (a2) and has a pH of 8 to 11; and Agent C, which contains an oxidizing agent, (a1) reducing agent; (a2) a compound represented by the following general formula (1) or a salt thereof, wherein the content thereof is 0.03 to 0.3% by mass. In the formula, the dotted line indicates the presence or absence of a π bond, and R 1 represents a hydroxyl group or an acetoxy group, R 2 represents a hydrogen atom or -COOR, wherein R represents a hydrogen atom, a methyl group or an ethyl group, and R 3 represents a hydrogen atom, an acetyl group, a methyl group or an ethyl group.

Images