Oxidative hair dye, hair dyeing method, kit, and first agent for oxidative hair dye

Abstract

To provide oxidative hair dye and a hair dyeing method by which hair can be dyed in color including green.SOLUTION: Oxidative hair dye is used by mixing a first agent for oxidative hair dye and a second agent for oxidative hair dye. In the first agent for oxidative hair dye, a dye intermediate including paramethyl aminophenol or salt thereof, a coupler including 2,6-diaminopyridine, and alkali agent are compounded, the compounding amount of the paramethyl aminophenol or salt thereof is 90 mol% or more for the total compounding amount of the dye intermediate, the compounding amount of the 2,6-diaminopyridine is 50 mol% or more for the total compounding amount of the coupler. In the second agent for oxidative hair dye, oxidizer is compounded, and pH is 9.3 or more. Also, provided are a hair dyeing method using the oxidative hair dye, a kit including the first agent for oxidative hair dye and the second agent for oxidative hair dye, and the first agent for oxidative hair dye.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to an oxidation hair dye, a hair dyeing method, a kit, and a first agent for the oxidation hair dye. More specifically, the present invention relates to an oxidation hair dye, a hair dyeing method, a kit, and a first agent for the oxidation hair dye that can dye hair in colors including green. [Background technology]

[0002] Oxidative hair dyes used to color hair work by dyeing the hair with an oxidative dye that has been absorbed into the hair through oxidative polymerization, and achieve longer-lasting hair color than other hair coloring agents such as acidic hair dyes.

[0003] As an example of an oxidation hair dye, Patent Document 1 discloses an oxidation hair dye characterized by containing (a) a porous cellulose powder having an average particle size of 1 to 20 μm and (b) at least one selected from ammonia and monoethanolamine. It is proposed that the oxidation hair dye of Patent Document 1 can reduce unpleasant odors derived from ammonia and monoethanolamine. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2019-167298 A Summary of the Invention [Problem to be solved by the invention]

[0005] Oxidative hair dyes can dye hair in a variety of colors by selecting the type of dye (oxidative dye, direct dye, etc.) that is added.

[0006] When a direct dye is used as a dye to be mixed in an oxidation hair dye, the hair tends to fade after dyeing, and the color of the hair may change over time. Therefore, by using an oxidation dye as a dye to be mixed in an oxidation hair dye, it is possible to dye hair in various colors while suppressing the change over time in the color of the dyed hair.

[0007] However, there are cases where the oxidation hair dye does not adequately dye hair to a desired color. In particular, there are cases where the oxidation hair dye containing an oxidation dye does not adequately dye hair to a color including green, and therefore there is a demand for an oxidation hair dye that can dye hair to a color including green.

[0008] In view of the above, an object of the present invention is to provide an oxidation hair dye capable of dyeing hair in a color including green, and a hair dyeing method using the oxidation hair dye. Another object of the present invention is to provide a kit for preparing the oxidation hair dye capable of dyeing hair in a color including green, and a first agent for the oxidation hair dye. [Means for solving the problem]

[0009] The present inventors conducted extensive research to solve the above problems and discovered that, when dyeing is performed at a pH of 9.3 or higher using an oxidation hair dye containing paramethylaminophenol or a salt thereof as a dye intermediate and 2,6-diaminopyridine as a coupler, hair can be dyed in a color including green, thereby completing the present invention.

[0010] That is, the present invention includes the following inventions. [1] An oxidation hair dye in which a first agent for an oxidation hair dye and a second agent for an oxidation hair dye are mixed together, The first agent for the oxidation hair dye contains a dye intermediate containing paramethylaminophenol or a salt thereof, a coupler containing 2,6-diaminopyridine, and an alkali agent, the amount of said paramethylaminophenol or a salt thereof is 90 mol % or more based on the total amount of said dye intermediate; the amount of the 2,6-diaminopyridine blended is 50 mol % or more based on the total amount of the couplers blended, The second agent for the oxidation hair dye contains an oxidizing agent, An oxidative hair dye with a pH of 9.3 or higher.

[0011] [2] The oxidative hair dye according to [1], wherein the pH is 9.5 or more and 11.0 or less. [3] The oxidation hair dye according to [1] or [2], wherein the molar ratio of the dye intermediate to the coupler is 1:0.4 to 2. [4] The oxidation hair dye according to any one of [1] to [3], wherein the first and second agents are in cream form. [5] A hair dyeing method using the oxidative hair dye composition according to any one of [1] to [4].

[0012] [6] A kit including a first agent for an oxidation hair dye and a second agent for an oxidation hair dye, The first agent for the oxidation hair dye contains a dye intermediate containing paramethylaminophenol or a salt thereof, a coupler containing 2,6-diaminopyridine, and an alkali agent, the amount of said paramethylaminophenol or a salt thereof is 90 mol % or more based on the total amount of said dye intermediate; the amount of the 2,6-diaminopyridine blended is 50 mol % or more based on the total amount of the couplers blended, The second agent for the oxidation hair dye contains an oxidizing agent, A kit for preparing an oxidation hair dye having a pH of 9.3 or higher by mixing the first agent for the oxidation hair dye and the second agent for the oxidation hair dye.

[0013] [7] The kit described in [6], wherein the pH is 9.5 or higher and 11.0 or lower. [8] The kit according to [6] or [7], wherein a molar ratio of the dye intermediate to the coupler is 1:0.4 to 2. [9] The oxidation hair dye according to any one of [6] to [8], wherein the first and second agents are in cream form.

[0014]

[10] A first agent for an oxidation hair dye, comprising a dye intermediate containing paramethylaminophenol or a salt thereof, a coupler containing 2,6-diaminopyridine, and an alkali agent, the amount of said paramethylaminophenol or a salt thereof is 90 mol % or more based on the total amount of said dye intermediate; The first agent for an oxidation hair dye, wherein the amount of the 2,6-diaminopyridine blended is 50 mol % or more based on the total amount of the coupler blended.

[0015]

[11] A first agent for an oxidative hair dye as described in

[10] , which is mixed with a second agent for an oxidative hair dye containing an oxidizing agent to prepare an oxidative hair dye having a pH of 9.3 or higher.

[12] The first agent for an oxidative hair dye according to

[10] or

[11] , wherein the pH is 9.5 or more and 11.0 or less.

[13] The first agent for an oxidation hair dye according to any one of

[10] to

[12] , wherein the molar ratio of the dye intermediate to the coupler is 1:0.4 to 2.

[14] The first agent for an oxidative hair dye according to any one of

[10] to

[13] , which is in a cream form. Effect of the Invention

[0016] The oxidation hair dye and hair dyeing method of the present invention can dye hair in colors including green. By using the kit of the present invention and the first agent for the oxidative hair dye and practicing the oxidative hair dye and hair dyeing method of the present invention, it is possible to dye hair in colors including green. [Brief description of the drawings]

[0017] [Figure 1] 1 is a photograph of an untreated hair strand and a hair strand dyed with the first agent of Example 1 and Comparative Examples 1 to 11. [Diagram 2] 1 is a photograph of a hair strand dyed using the first agents of Examples 2 and 3 and Comparative Examples 12 to 15. [Diagram 3] Photographs of hair strands dyed using the first agents of Examples 1, 4 and 5 and Comparative Examples 16 and 17. [Figure 4]1 is a photograph of a hair strand dyed using the first agents of Examples 1, 6 to 8, and Comparative Example 18. [Diagram 5] 1 is a photograph of a hair strand dyed using the first agent of Example 9. [Figure 6] FIG. 1 is a diagram summarizing the saturation C* and hue angle h of hair strands dyed using the first agents of the Examples and Comparative Examples. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] The present invention will be described below based on an embodiment of the present invention (hereinafter, referred to as "the present embodiment").

[0019] 1. Oxidative hair dye The oxidative hair dye of this embodiment is a mixture of a first agent for oxidative hair dye and a second agent for oxidative hair dye, the first agent for oxidative hair dye contains a dye intermediate containing paramethylaminophenol or its salt, a coupler containing 2,6-diaminopyridine, and an alkali agent, the amount of paramethylaminophenol or its salt is 90 mol % or more based on the total amount of the dye intermediate, the amount of 2,6-diaminopyridine is 50 mol % or more based on the total amount of the coupler, the second agent for oxidative hair dye contains an oxidizing agent, and the pH of the oxidative hair dye obtained by mixing the first agent for oxidative hair dye and the second agent for oxidative hair dye is 9.3 or more. The oxidative hair dye of this embodiment can dye hair in a color including green.

[0020] In the description of this specification, "a color containing green" means L * C * h color space (L * represents lightness, and C represents lightness. * In the color system (wherein h represents saturation and h represents hue angle), this refers to a color with a hue angle h of 130 to 230°. When a color closer to green is desired, the hue angle h is preferably 150 to 210°, and more preferably 160 to 200°.

[0021] Saturation C *The chroma C varies depending on the desired color tone, but is, for example, 5 to 50. When a more vivid color tone including green is desired, the chroma C * is preferably 10 or more, more preferably 17 or more. * Although it varies depending on the lightness of the desired color, it is, for example, 20 or more and 90 or less. When it is desired that the color containing green has a higher lightness, the lightness L * is preferably 45 or more, more preferably 50 or more, and even more preferably 55 or more.

[0022] Hereinafter, the first agent for the oxidative hair dye in the oxidative hair dye of this embodiment may be referred to as the "first agent," and the second agent for the oxidative hair dye in the oxidative hair dye of this embodiment may be referred to as the "second agent."

[0023] <First agent for oxidation hair dye> The first agent for the oxidative hair dye in the oxidative hair dye of this embodiment contains a dye intermediate containing paramethylaminophenol or a salt thereof, a coupler containing 2,6-diaminopyridine, and an alkaline agent, and the amount of paramethylaminophenol or a salt thereof is 90 mol % or more relative to the total amount of the dye intermediate, and the amount of 2,6-diaminopyridine is 50 mol % or more relative to the total amount of the coupler.

[0024] The first agent contains paramethylaminophenol or its salt (e.g., sulfate, hydrochloride, etc.) as a dye intermediate, and 2,6-diaminopyridine as a coupler. By using paramethylaminophenol or its salt and 2,6-diaminopyridine, hair can be dyed in a color including green.

[0025] (dye intermediates) The first agent may further contain one or more dye intermediates other than paramethylaminophenol or its salt. In this case, the amount of paramethylaminophenol or its salt in the first agent is 90 mol% or more with respect to the total amount of all dye intermediates contained in the first agent. When the amount of dye intermediates other than paramethylaminophenol or its salt is less than 10 mol%, hair can be dyed in various hues including green. From the viewpoint of dyeing hair in a color closer to green, the amount of paramethylaminophenol or its salt in the first agent is preferably 93 mol% or more with respect to the total amount of all dye intermediates contained in the first agent, more preferably 97 mol% or more, even more preferably 99 mol% or more, and even more preferably 100 mol%.

[0026] Examples of dye intermediates other than paramethylaminophenol or its salts include paraphenylenediamine or its salts (e.g., hydrochloride, sulfate, etc.), N-phenylparaphenylenediamine or its salts (e.g., hydrochloride, acetate, etc.), orthochloroparaphenylenediamine or its salts (e.g., sulfate, etc.), orthoaminophenol or its salts (e.g., sulfate, hydrochloride, etc.), paraaminophenol or its salts (e.g., sulfate, hydrochloride, etc.), toluene-2,5-diamine or its salts (e.g., hydrochloride, sulfate, etc.), toluene-3,4-diamine or its salts (e.g., Examples of the dye intermediate include paramethylaminophenol or a salt thereof (e.g., hydrochloride, sulfate, etc.), 1-amino-4-methylaminoanthraquinone, 1,4-diaminoanthraquinone, 1-hydroxyethyl-4,5-diaminopyrazole or a salt thereof (e.g., sulfate, etc.), 2,2'-[(4-aminophenyl)imino]bisethanol or a salt thereof (e.g., sulfate, etc.), 2,4-diaminophenol or a salt thereof (e.g., hydrochloride, sulfate, etc.), 4,4'-diaminodiphenylamine or a salt thereof (e.g., sulfate, etc.), and N,N'-bis(4-aminophenyl)-2,5-diamino-1,4-quinone diimine. According to the desired hue including a green tint, one or more dye intermediates other than paramethylaminophenol or a salt thereof can be selected, and the amount of the dye intermediates can be appropriately adjusted.

[0027] The amount of paramethylaminophenol or a salt thereof blended in the first agent is, for example, from 0.01% by mass to 6% by mass. In addition, in terms of dyeing hair in colors including green and achieving a brighter color, the amount of paramethylaminophenol or a salt thereof in the first agent is preferably 0.01% by mass or more and 2.5% by mass or less, and more preferably 0.01% by mass or more and 1.5% by mass or less.

[0028] The amount of the dye intermediate containing paramethylaminophenol or a salt thereof blended in the first agent is, for example, from 0.01% by mass to 2.5% by mass.

[0029] (coupler) The first agent may further contain one or more couplers other than 2,6-diaminopyridine. In this case, the amount of 2,6-diaminopyridine in the first agent is 50 mol% or more based on the total amount of all couplers contained in the first agent. When the amount of couplers other than 2,6-diaminopyridine is less than 50 mol%, hair can be dyed in various hues including green. From the viewpoint of dyeing hair in a color closer to green, the amount of 2,6-diaminopyridine in the first agent is preferably 60 mol% or more based on the total amount of all couplers contained in the first agent, more preferably 70 mol% or more, even more preferably 80 mol% or more, even more preferably 90 mol% or more, particularly preferably 95 mol% or more, and most preferably 100 mol%.

[0030] Examples of couplers other than 2,6-diaminopyridine include resorcin, 2-methylresorcin, 2-chlororesorcin, 4-chlororesorcin, 5-aminoorthocresol or its salts (e.g., sulfate, etc.), metaaminophenol or its salts (e.g., sulfate, etc.), metaphenylenediamine or its salts (e.g., hydrochloride, etc.), 1,5-dihydroxynaphthalene, 2,4-diaminophenoxyethanol or its salts (e.g., hydrochloride, etc.), 3,3'-iminodiphenol, 5-(2-hydroxyethylamino)-2-methylphenol, α-naphthol, etc. Depending on the desired hue containing a green tint, one or more couplers other than 2,6-diaminopyridine can be selected and the amount of the couplers blended can be appropriately adjusted.

[0031] The amount of 2,6-diaminopyridine blended in the first agent is, for example, from 0.01% by mass to 3% by mass. In addition, in terms of dyeing hair in colors including green and achieving a brighter color, the amount of 2,6-diaminopyridine contained in the first agent is preferably 0.01% by mass or more and 2.5% by mass or less, and more preferably 0.01% by mass or more and 1.5% by mass or less.

[0032] The amount of the coupler containing 2,6-diaminopyridine blended in the first agent is, for example, from 0.01% by mass to 2.5% by mass.

[0033] The molar ratio of the total amount of dye intermediates to the total amount of couplers is, for example, 1:0.5-2, and from the viewpoint of more sufficiently carrying out the oxidative polymerization of the dye intermediates and the couplers, is preferably 1:0.7-1.5, and more preferably 1:0.8-1.2.

[0034] The total blend amount of the dye intermediates and the couplers in the first agent may be, for example, 0.1% by mass or more and 9% by mass or less, or 0.1% by mass or more and 5% by mass or less.

[0035] (Alkaline agent) The first agent is a mixture of one or more alkaline agents. The alkaline agent promotes the action of the oxidizing agent contained in the oxidation hair dye, and improves the dyeability by swelling the hair and improving the penetration of the dye into the hair. Examples of the alkaline agent include metal hydroxides such as sodium hydroxide and potassium hydroxide; metal carbonates such as sodium carbonate and potassium carbonate; metal phosphates such as sodium phosphate; ammonia; ammonium salts such as ammonium carbonate and ammonium sulfate; alkanolamines such as monoethanolamine, triethanolamine, and isopropanolamine; and basic amino acids such as arginine.

[0036] The amount of the alkaline agent in the first agent is, for example, from 0.1% by mass to 5% by mass.

[0037] (pH) The pH of the first agent may be appropriately set so that the pH of the oxidation hair dye obtained by mixing the first agent and the second agent is 9.3 or higher. The pH is a value measured at 25°C using a known pH meter (the same meaning is used for the pH below). The pH of the first agent is, for example, 9.5 or more. The pH of the first agent may be, for example, 9.5 or more and 11.0 or less, or 9.6 or more and 11.0 or less.

[0038] (optional ingredient) Various components can be optionally blended into the first agent. Optionally blended components include the same components as those optionally blended into known first agents for oxidation hair dyes. Optionally blended components include, for example, cationic surfactants, nonionic surfactants, higher alcohols, polyhydric alcohols, hydrocarbons, oils and fats, antioxidants, chelating agents, water, etc.

[0039] The first agent is preferably a blend of a nonionic surfactant, a higher alcohol, and water in order to form an emulsified formulation.

[0040] Examples of nonionic surfactants include polyoxyethylene alkyl ethers (polyoxyethylene cetyl ether, etc.), polyoxyethylene alkylene ethers (polyoxyethylene oleyl ether, etc.), polyoxyethylene polyoxypropylene alkyl ethers, polyoxyethylene polyoxypropylene alkylene ethers, polyoxypropylene alkyl ethers, polyoxypropylene alkylene ethers, glycerin fatty acid esters, polyoxyethylene glycerin fatty acid esters, polyglycerin fatty acid esters, sorbitol fatty acid esters, polyoxyethylene sorbitol fatty acid esters, polyethylene glycol derivatives of monoglycerides and diglycerides obtained from vegetable oils, sorbitan fatty acid esters, polyoxyethylene sorbitan fatty acid esters, polyoxyethylene hardened castor oil, etc., and one or more of these can be used. The blending concentration of the nonionic surfactant in the first agent can be appropriately set, and can be, for example, 0.1% by mass or more and 15% by mass or less.

[0041] Examples of higher alcohols include monohydric alcohols having 12 to 24 carbon atoms, specifically saturated or unsaturated linear higher alcohols (myristyl alcohol, cetanol, oleyl alcohol, cetostearyl alcohol, stearyl alcohol, behenyl alcohol, etc.), and branched higher alcohols (isocetyl alcohol, octyldodecanol, isostearyl alcohol, etc.), and one or more of these can be used. The blending concentration of the higher alcohol in the first agent can be appropriately set, and can be, for example, 2% by mass to 20% by mass.

[0042] The amount of water in the first agent can be appropriately set, but is, for example, from 40% by mass to 95% by mass.

[0043] (Dosage form) The dosage form of the first agent may be, for example, liquid, cream, gel, powder, etc., and from the viewpoint of increasing the viscosity of the oxidation hair dye and making it easier to apply to hair, a cream form is preferred.

[0044] (viscosity) The viscosity of the first part is, for example, 30,000 mPa·s or more and 60,000 mPa·s or less after 60 seconds when measured at 25° C. and 12 rpm using a Brookfield viscometer.

[0045] (Manufacturing method) The first agent can be produced by a known method for producing the first agent for oxidation hair dyes depending on the components to be blended. One example of the method for producing the first agent is a method of mixing a dye intermediate containing paramethylaminophenol or a salt thereof, a coupler containing 2,6-diaminopyridine, and an alkali agent.

[0046] <Second agent for oxidation hair dye> The second agent for the oxidation hair dye in the oxidation hair dye of the present embodiment contains an oxidizing agent.

[0047] (Oxidizing agent) The oxidizing agent to be added to the second agent may be an oxidizing agent that is generally used in the second agent of an oxidation hair dye. Examples of the oxidizing agent include hydrogen peroxide, bromate, percarbonate, and perborate, and it is preferable to use hydrogen peroxide in order to dye hair more deeply. The amount of the oxidizing agent to be added to the second agent is not particularly limited, but is, for example, 0.3% by mass or more and 7% by mass or less.

[0048] (optional ingredient) The second agent can further contain various optional components, including the same components as those optionally contained in known second agents, such as nonionic surfactants, cationic surfactants, higher alcohols, hydrocarbons, oils and fats, polyhydric alcohols, antioxidants, chelating agents, pH adjusters, and water.

[0049] In order to make the second agent into an emulsified formulation, it is preferable that a nonionic surfactant, a higher alcohol, and water are blended. The nonionic surfactant, higher alcohol, and water used in the second agent can be the same as the nonionic surfactant, higher alcohol, and water used in the first agent, and can be used in the same blending amounts.

[0050] Depending on the type of oxidizing agent to be blended, a pH adjuster may be added to the second agent for stabilization. For example, when hydrogen peroxide is used as the oxidizing agent, it can be stabilized by adding a pH adjuster such as an acid to make it weakly acidic (for example, pH 2 or more and less than 5).

[0051] The dosage form of the second agent may be, for example, liquid, cream, gel, powder, etc., and from the viewpoint of increasing the viscosity of the oxidation hair dye and making it easier to apply to hair, a cream form is preferred.

[0052] (viscosity) The viscosity of the second part is, for example, 1000 mPa·s or more and 10000 mPa·s or less after 60 seconds when measured at 25° C. and 12 rpm using a Brookfield viscometer.

[0053] (Manufacturing method) The second agent can be produced by a known method for producing a second agent for an oxidation hair dye, depending on the components to be blended.

[0054] <Oxidation hair dye> The oxidative hair dye of the present embodiment is used by mixing the first agent for oxidative hair dye and the second agent for oxidative hair dye. The mixing may be performed in the same manner as the mixing of the first agent and the second agent in known oxidative hair dyes.

[0055] In the oxidation hair dye of this embodiment, the mixing ratio of the first agent and the second agent can be appropriately set, for example, the first agent:second agent (weight ratio) is 1:0.5-2.

[0056] The oxidative hair dye of the present embodiment may be a mixture of other agents in addition to the first and second agents. When the oxidative hair dye of the present embodiment is a mixture of the first and second agents and other agents, the mixing ratio may be appropriately set.

[0057] (pH) The pH of the oxidative hair dye of the present embodiment is 9.3 or more. By adjusting the pH to 9.3 or more, hair can be dyed in a color including green. The pH is measured at 25° C. using a known pH meter.

[0058] The pH of the oxidative hair dye is preferably 9.5 or more, more preferably 9.6 or more, from the viewpoint of dyeing hair in a color including a darker green, and is preferably 11.0 or less, more preferably 10.5 or less, from the viewpoint of reducing the risk of damage to hair. From the above viewpoint, the pH is preferably 9.5 or more and 11.0 or less, and more preferably 9.6 or more and 10.5 or less.

[0059] The form of the oxidation hair dye of the present embodiment when used is not particularly limited, and examples thereof include liquid, cream, wax, gel, foam, etc. From the viewpoint of ease of application to hair, the cream form is preferable.

[0060] (Manufacturing method) The method for producing the oxidation hair dye of the present embodiment is not particularly limited, and examples thereof include a method in which the first and second agents are mixed prior to hair dyeing.

[0061] (How to use) The method of using the oxidative hair dye of the present embodiment is not particularly limited, and for example, a method of using a known oxidative hair dye can be used. One example of the method of use is a method in which an appropriate amount of the oxidative hair dye of the present embodiment is applied to hair, and the hair is dyed for a predetermined time (for example, 15 minutes or more and 30 minutes or less), and then the hair is washed and dried.

[0062] 2. Oxidation hair dye method The oxidation hair dyeing method of the present embodiment can dye hair in a color including green by applying an oxidation hair dye obtained by mixing the first agent for the oxidation hair dye and the second agent for the oxidation hair dye described above to hair. Mixing the first and second agents, applying it to the hair, and washing the hair can be carried out in the same manner as for known oxidation hair dyes.

[0063] 3. Kit The kit of this embodiment is a kit including a first agent for an oxidative hair dye and a second agent for an oxidative hair dye, the first agent for the oxidative hair dye containing a dye intermediate containing paramethylaminophenol or a salt thereof, a coupler containing 2,6-diaminopyridine, and an alkaline agent, the amount of the paramethylaminophenol or a salt thereof being 90 mol % or more relative to the total amount of the dye intermediate, the amount of the 2,6-diaminopyridine being 50 mol % or more relative to the total amount of the coupler, and the second agent for the oxidative hair dye containing an oxidizing agent, and the kit is for preparing an oxidative hair dye having a pH of 9.3 or more by mixing the first agent for the oxidative hair dye and the second agent for the oxidative hair dye.

[0064] The first agent for oxidative hair dye and the second agent for oxidative hair dye can be the same as those used in the oxidative hair dye of the present embodiment. The first agent for oxidative hair dye and the second agent for oxidative hair dye can be mixed using the kit of the present embodiment to be used as an oxidative hair dye. The kit of the present embodiment may further include other agents in addition to the first and second agents.

[0065] 4. First agent for oxidation hair dyes The first agent for an oxidative hair dye of this embodiment is a first agent for an oxidative hair dye containing a dye intermediate containing paramethylaminophenol or a salt thereof, a coupler containing 2,6-diaminopyridine, and an alkaline agent, in which the amount of the paramethylaminophenol or a salt thereof is 90 mol % or more relative to the total amount of the dye intermediate, and the amount of the 2,6-diaminopyridine is 50 mol % or more relative to the total amount of the coupler.

[0066] The first agent for the oxidative hair dye of the present embodiment can be used as the first agent for the oxidative hair dye of the present embodiment. The first agent for the oxidative hair dye of the present embodiment can be mixed with the second agent for the oxidative hair dye to be used as an oxidative hair dye. EXAMPLES

[0067] The present invention will be described below with reference to examples and comparative examples, but the present invention is not limited to these examples.

[0068] Preparation of the first agent The dye intermediates and couplers shown in Tables 2 to 7 were used in the amounts shown, and the other components shown in Table 1 were mixed in a conventional manner to prepare a first agent (cream-like). However, in the tests in Table 3, phosphoric acid was added in addition to the components in Table 1 to adjust the pH of the first agent. In the tests shown in Table 7, in addition to the components shown in Table 1, aqueous ammonia was added to adjust the pH of the first agent.

[0069] The molecular formulas and molecular weights of the dye intermediates and couplers shown in Tables 2 to 7 are as follows. [Dye intermediates] Paramethylaminophenol sulfate ((C7H9NO)2·H2SO4) (molecular weight: 344.38) Paraphenylenediamine (C6H8N2) (Molecular weight: 108.14) Toluene-2,5-diamine sulfate (CH 10 N2·H2SO4) (molecular weight: 220.25) Paraaminophenol (C6H7NO) (Molecular weight: 109.13) 2,2'-[(4-aminophenyl)imino]bisethanol sulfate (C 10 H 16 N2O2 H2SO4) (molecular weight: 294.32) [coupler] 2,6-Diaminopyridine (C5H7N3) (Molecular weight: 109.13) 2,4-Diaminophenoxyethanol hydrochloride (C8H 12 N2O2·2HCl) (molecular weight: 241.11) Resorcinol (C6H6O2) (Molecular weight: 110.11)

[0070] In addition, the molar concentration of paramethylaminophenol sulfate in Tables 2 to 7 is calculated as one molecule of the sulfate salt of paramethylaminophenol (C6H7NO·1 / 2H2SO4) (molecular weight: 172.19), since paramethylaminophenol sulfate is the sulfate salt of two molecules of paramethylaminophenol.

[0071] Test Method The pH of the first agent of each Example and Comparative Example prepared above was measured. Furthermore, 1 g of the first agent of each Example and Comparative Example was mixed with 1 g of the second agent (manufactured by Milbon Co., Ltd., "Enogu Oxidant 6.0"), and the pH was measured. 1 g of the oxidative hair dye, a mixture of 1 g of the first agent and 1 g of the second agent, was applied to a bundle of yak hair (manufactured by Beaulax, yak hair: product name BM-YK-A, length 10 cm) and left at room temperature for 20 minutes to dye the hair. The dyed bundle of hair was measured for color difference (lightness L * ,Saturation C * , hue angle h) were measured. The color difference of the untreated hair bundle was also measured. * :84.5, Saturation C * :9.8, hue angle h:89.6°.

[0072] Evaluation of hair dyeability to colors including green Measured color difference saturation C * Based on the hue angle h, the dyeability of hair to colors including green was evaluated according to the following criteria. ○○○○: Hue angle h=160~200, and saturation C * = 17 or more ○○○: Hue angle h=160~200, and saturation C * = Less than 17 ○○ :Hue angle h=150~210 ○ :Hue angle h=130~230 × : Hue angle h = outside the range of 130 to 230

[0073] [Table 1]

[0074] Example 1 and Comparative Examples 1 to 11 Preparation of the first agent using various dye intermediates and couplers The oxidative hair dye compositions of Example 1 and Comparative Examples 1 to 11 were prepared using the first and second agents containing the dye intermediates and couplers in the amounts shown in Table 2, and were evaluated for their dyeing properties in colors including green using the above test methods. The results are shown in Table 2. A photograph of the dyed hair bundle is shown in Figure 1.

[0075] [Table 2]

[0076] The first agents of Comparative Examples 1 to 11, which used various dye intermediates other than paramethylaminophenol sulfate and / or various couplers other than 2,6-diaminopyridine, were unable to dye hair in colors including green. In contrast, the first agent of Example 1, which used the dye intermediate paramethylaminophenol sulfate and the coupler 2,6-diaminopyridine, was able to dye hair in colors including green. In addition, even though the same 2,6-diaminopyridine was used as the coupler, when paraaminophenol (Comparative Example 3) was used as the dye intermediate, the hair was dyed blue, whereas when paramethylaminophenol (Example 1) was used, the hair was dyed green, as described above.

[0077] Here, in the Journal of the Japanese Society of Cosmetic Science, Vol. 45, No. 1, pp. 9-15 (2021), it is reported that when the dye intermediate N-methyl-4-aminophenol sulfate and the coupler m-aminophenol were oxidized with air, the color changed from purple to blue-purple to blue (p. 11, right column). In addition, the report also reports that the absorbance of the product obtained by the above air oxidation matched the absorbance of the product when the dye intermediate 4-aminophenol hydrochloride was used, and therefore it is presumed that the Me group of the methylamino group was eliminated at the oxidative coupling reaction stage, resulting in the exact same product (p. 12, left column; p. 14, left column). However, in Table 2, para-aminophenol and para-methylaminophenol were used to dye hair in different colors, which was a result different from that reported above.

[0078] Examples 2 and 3 and Comparative Examples 12 to 15 Preparation of first agent with different pH First preparations with different pH values ​​were prepared as shown in Table 3. Each first preparation was evaluated for dyeability in colors including green using the above test method, and the results are shown in Table 3. A photograph of the dyed hair bundle is shown in Figure 2.

[0079] [Table 3]

[0080] In the first agents of Examples 2 and 3, in which the pH of the first agent was 9.62 or more and the pH after mixing of the first agent and the second agent was 9.57 or more, it was possible to dye hair in a color including green. However, in Comparative Examples 12 to 15, in which the pH of the first agent was 9.51 or less and the pH after mixing of the first agent and the second agent was 9.17 or less, it was not possible to dye hair in a color including green. As described above, it is found that in order to dye hair in a color including green, it is necessary for the pH of the first agent to be 9.6 or more, or for the pH after mixing of the first agent and the second agent to be 9.3 or more.

[0081] Examples 1, 4 and 5 and Comparative Examples 16 and 17 Variation in paramethylaminophenol / dye intermediate mole % and 2,6-diaminopyridine / coupler mole % First agents were prepared with different molar percentages of paramethylaminophenol / dye intermediate and 2,6-diaminopyridine / coupler as shown in Table 4. The first agents obtained were evaluated for their dyeing properties in colors including green using the above test methods, and the results are shown in Table 4. A photograph of the dyed hair bundle is shown in Figure 3.

[0082] [Table 4]

[0083] In Comparative Examples 16 and 17, in which the paramethylaminophenol / dye intermediate was 75 mol % or less, it was not possible to dye the hair in a color including green. In Examples 1, 4 and 5, in which the 2,6-diaminopyridine / coupler ratio was 50 mol % or more, hair could be dyed in a color including green. Therefore, it is found that in order to dye hair in a color including green, the blending amount of 2,6-diaminopyridine needs to be 50 mol % or more relative to the total blending amount of coupler.

[0084] Examples 1, 6 to 8 and Comparative Example 18 Change in mole percent of paramethylaminophenol / dye intermediate First agents were prepared with varying molar percentages of paramethylaminophenol / dye intermediate as shown in Table 5. The first agents obtained were evaluated for their dyeing properties in colors including green using the above test methods, and the results are shown in Table 5. A photograph of the dyed hair bundle is shown in Figure 4.

[0085] In Example 1 (reprinted) and Comparative Example 18 in Table 5, the pH of the first agent was 10.5 and 10.52, respectively, and the pH after mixing the first agent and the second agent was 9.98 and 9.97, respectively. In addition, the pH of the first agent in Examples 6, 7, and 8 was all 10 or more, and the pH after mixing the first agent and the second agent was all 9.9 or more.

[0086] [Table 5]

[0087] In Comparative Example 18, where the paramethylaminophenol / dye intermediate was 75 mol % or less, it was not possible to dye the hair a color including green. However, in the first agents of Example 1 and Examples 6 to 8, where the paramethylaminophenol / dye intermediate was 90 mol % or more, it was possible to dye the hair a color including green. Therefore, it is found that in order to dye the hair a color including green, the blending amount of paramethylaminophenol or a salt thereof needs to be 90 mol % or more relative to the total blending amount of the dye intermediate.

[0088] Example 9 Preparation of the first agent using high concentrations of paramethylaminophenol and 2,6-diaminopyridine The amounts of paramethylaminophenol sulfate and 2,6-diaminopyridine were increased to the upper limit of the hair dye manufacturing and sales approval standards to prepare the first agent. The first agent obtained was evaluated using the above test methods and for its dyeing properties in colors including green, and the results are shown in Table 6. A photograph of the dyed hair bundle is shown in Figure 5.

[0089] [Table 6]

[0090] Even when high concentrations of paramethylaminophenol and 2,6-diaminopyridine were used, hair could be dyed in shades including green. Furthermore, the saturation C of the hair bundle dyed using the first agent of the examples and the comparative examples * Figure 6 shows a summary of the hue angle h and the

[0091] The embodiments and examples disclosed herein are illustrative in all respects and are not restrictive. The scope of the present invention is defined by the claims, not the above description, and includes all modifications within the meaning and scope of the claims.

Claims

1. An oxidation hair dye comprising a mixture of a first agent for an oxidation hair dye and a second agent for an oxidation hair dye, The first agent for the oxidation hair dye contains a dye intermediate containing paramethylaminophenol or a salt thereof, a coupler containing 2,6-diaminopyridine, and an alkali agent, the amount of the paramethylaminophenol or a salt thereof is 90 mol % or more based on the total amount of the dye intermediate; the amount of the 2,6-diaminopyridine blended is 50 mol % or more based on the total amount of the coupler blended, The second agent for the oxidation hair dye contains an oxidizing agent, An oxidation hair dye having a pH of 9.3 or more.

2. The oxidative hair dye according to claim 1, wherein the pH is 9.5 or more and 11.0 or less.

3. 3. The oxidation hair dye according to claim 1, wherein a molar ratio of the dye intermediate to the coupler is 1:0.4 to 1:

2.

4. A hair dyeing method using the oxidative hair dye composition according to claim 1 or 2.

5. A kit including a first agent for an oxidation hair dye and a second agent for an oxidation hair dye, The first agent for the oxidation hair dye contains a dye intermediate containing paramethylaminophenol or a salt thereof, a coupler containing 2,6-diaminopyridine, and an alkali agent, the amount of the paramethylaminophenol or a salt thereof is 90 mol % or more based on the total amount of the dye intermediate; the amount of the 2,6-diaminopyridine blended is 50 mol % or more based on the total amount of the coupler blended, The second agent for the oxidation hair dye contains an oxidizing agent, A kit for preparing an oxidation hair dye having a pH of 9.3 or more by mixing the first agent for the oxidation hair dye and the second agent for the oxidation hair dye.

6. The kit of claim 5 , wherein the pH is 9.5 or more and 11.0 or less.

7. 7. The kit according to claim 5 or 6, wherein a molar ratio of the dye intermediate to the coupler is 1:0.4-2.

8. A first agent for an oxidation hair dye, comprising a dye intermediate containing paramethylaminophenol or a salt thereof, a coupler containing 2,6-diaminopyridine, and an alkali agent, the amount of the paramethylaminophenol or a salt thereof is 90 mol % or more based on the total amount of the dye intermediate; The first agent for an oxidation hair dye, wherein the blending amount of the 2,6-diaminopyridine is 50 mol % or more based on the total blending amount of the coupler.

9. 9. The first agent for an oxidation hair dye according to claim 8, wherein the molar ratio of said dye intermediate to said coupler is 1:0.4-2.

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