Oxidative hair dye

Abstract

To provide: an oxidative hair dye that can suppress hair damage caused by alkaline agents during oxidative dyeing and that does not require repeated dyeing; and an oxidative hair dye that is free of ammonia and monoethanolamine but has color development and color retention performance comparable to conventional hair dyes.SOLUTION: The inventors have discovered that exclusion of both ammonia and monoethanolamine from an oxidative hair dye enables the pH to be between 6 and 8.5 when it is mixed with a second agent containing an oxidizing agent, while still achieving dyeing performance comparable to conventional oxidative hair dyes. The present invention provides an oxidative hair dye obtained by mixing a first agent containing an oxidative dye but free of ammonia and monoethanolamine with a second agent containing an oxidizing agent.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to an oxidation hair dye, more particularly to an oxidation hair dye that does not contain ammonia and monoethanolamine. [Background technology]

[0002] Among the many types of hair color, oxidation hair dyes are widely used worldwide because they have a relatively long color retention and excellent dyeing power. In the two-component oxidation hair dyes that are common as ingredients of oxidation hair dyes, oxidation hair dyes are known that are composed of a first component containing an alkaline agent such as ammonia or monoethanolamine, and a second component containing an oxidizing agent such as hydrogen peroxide. The alkaline agent is generally an essential component of oxidation hair dyes, and promotes the action of the oxidizing agent contained in the second component. In addition, the alkaline agent has the effect of opening the cuticle, which causes the hair to swell and improves the penetration of the dye into the hair. Since the action of such an alkaline agent is required in oxidation hair dyes, there are no products that do not contain both ammonia and monoethanolamine.

[0003] However, the alkaline agent contained in the oxidative hair dye is one of the causes of hair damage during hair dyeing. From the viewpoint of suppressing hair damage during hair dyeing, it can be said that an oxidative hair dye that does not contain an alkaline agent is preferable.

[0004] However, while it is desirable for an oxidative hair dye to penetrate deep into the hair in terms of color development and fading, an oxidative hair dye that does not contain an alkaline agent has the problem that the ingredients do not penetrate the hair easily. There are also neutral oxidative hair dyes that do not contain an alkaline agent, but they cannot obtain the same hair dyeing power as an oxidative hair dye that contains an alkaline agent by one dyeing, and require cumulative dyeing. For example, Patent Document 1 and Patent Document 2 disclose a gray hair dye that does not contain an alkaline agent other than the oxidative dye, and is a two-component type consisting of a first agent with a pH of 6 to 9 and a second agent with a pH of 1 to 7 containing hydrogen peroxide as an essential component, and the pH of the first agent and the second agent when mixed is 6 to 6.5. The gray hair dyes disclosed in these documents are also gray hair dyes for the cumulative hair dyeing method that gradually makes gray hair less noticeable without damaging the hair. The fact that cumulative dyeing is not required means that a single treatment with the hair dye can obtain the same hair dyeing power as a normal non-accumulation type oxidation hair dye. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 62-42916 [Patent Document 2] Japanese Patent Application Publication No. 61-78714 Summary of the Invention [Problem to be solved by the invention]

[0006] As mentioned above, conventional oxidative hair dyes contain alkaline agents such as ammonia and monoethanolamine as ingredients, which causes damage to hair. In addition, although there are neutral oxidative hair dyes that do not contain alkaline agents from the viewpoint of preventing hair damage, they cannot achieve the same dyeing power as oxidative hair dyes that contain alkaline agents in a single dyeing, and require cumulative dyeing.

[0007] The present invention aims to provide an oxidation hair dye that can suppress hair damage caused by an alkaline agent during oxidation hair dyeing and does not require cumulative hair dyeing. It also aims to provide an oxidation hair dye that does not contain an alkaline agent but has high hair dyeing power that is comparable to conventional hair colorants in terms of color development and fading performance. [Means for solving the problem]

[0008] The present inventors have investigated various ingredients in order to solve the above problems. The present inventors have found that by not containing ammonia and monoethanolamine in the first agent of an oxidation hair dye, and more preferably not containing any other alkaline agent, when the first agent and the second agent containing an oxidizing agent are mixed, the pH can be adjusted to 6 to 8.5, preventing damage to the dyed hair during dyeing, and providing hair dyeing power that is comparable to that of conventional oxidation hair dyes without the need for cumulative dyeing.

[0009] The inventors also found that by not containing both ammonia and monoethanolamine in the oxidative hair dye, hair damage can be suppressed and hair dyeing power comparable to that of conventional oxidative hair dyes can be obtained. Furthermore, the inventors found that by containing an oily component in the second agent, the oxidative hair dye efficiently penetrates the hair surface during dyeing.

[0010] That is, the present invention provides an oxidation hair dye obtained by mixing a first agent containing an oxidation dye and not containing ammonia and monoethanolamine with a second agent containing an oxidizing agent.

[0011] The present invention also provides the above-mentioned oxidative hair dye, characterized in that the first agent does not contain an alkaline agent, the pH of the mixture becomes 6 to 8.5 when the first agent and the second agent are mixed, and the oxidative hair dye is not a cumulative type hair dye.

[0012] The present invention also provides the above-mentioned oxidation hair dye, which, when applied to hair, unevenly dyes the hair surface.

[0013] The present invention also provides the above-mentioned oxidative hair dye, wherein the second agent contains 4% by mass or more of an oily component in the second agent. Effect of the Invention

[0014] According to the oxidative hair dye of the present invention, hair damage caused by ammonia and monoethanolamine during oxidative hair dyeing can be suppressed, and cumulative hair dyeing is not required. Furthermore, according to the oxidative hair dye of the present invention, even though it does not contain ammonia and monoethanolamine, the coloring performance and fading performance are not inferior to conventional hair colors, and it has high hair dyeing power. Furthermore, according to the oxidative hair dye of the present invention, since it does not contain an alkaline agent, the melanin pigment in the hair is not destroyed to the inside during hair dyeing, and hair damage can be further suppressed. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] The oxidation hair dye of the present invention is obtained by mixing a first agent containing an oxidation dye and not containing ammonia or monoethanolamine with a second agent containing an oxidizing agent.

[0016] The first agent containing an oxidation dye and not containing ammonia and monoethanolamine, and the second agent containing an oxidizing agent will be described in detail below. The oxidation hair dye described below is merely exemplified to explain the present invention, and is not limited thereto. In addition, in this specification, unless otherwise specified, the numerical values ​​specifying the content of the components indicate the content of each of the first agent and the second agent in the oxidation hair dye, and are not the content in the oxidation hair dye which is a mixture of the first agent and the second agent. The numerical values ​​in mass% indicating the content of the components are the numerical values ​​in the formulation including a solubilizing agent such as water, when such a solubilizing agent is used.

[0017] The two-component oxidative hair dye of the present invention is composed of a first agent containing an oxidative dye and a second agent containing an oxidizing agent, and the first and second agents are mixed together when used. The oxidative hair dye of the present invention refers to the state of a mixture of, for example, the first and second agents of a multi-component oxidative hair dye, and its composition refers to, for example, the composition of the mixture of the first and second agents. When the first or second agent is specifically mentioned, the composition of only the first or second agent is indicated.

[0018] <Oxidation dyes> In the oxidation hair dye of the present invention, the first agent contains an oxidation dye. The oxidation dye blended in the first agent of the present invention is a dye that develops color by oxidative polymerization with an oxidizing agent. It is usually divided into a dye intermediate and a coupler. The dye intermediate is not particularly limited, but examples thereof include phenylenediamines, aminophenols, diaminopyridines, and salts thereof. Examples of salts include hydrochlorides, sulfates, and acetates. One or more of these can be used in appropriate combination. Examples of dye intermediates include p-phenylenediamine, toluene-2,5-diamine, p-aminophenol, N,N-bis(β-hydroxyethyl)-p-phenylenediamine, N-(β-hydroxyethyl)-N-ethyl-p-phenylenediamine, 2-(β-hydroxyethyl)-p-phenylenediamine, and salts thereof. The content of the dye intermediate is not particularly limited, but is preferably 0.1% by mass to 10% by mass, more preferably 0.5% by mass to 7.5% by mass, and even more preferably 1.0% by mass to 5.0% by mass, for example, to obtain an excellent hair dyeing effect.

[0019] The coupler is not particularly limited, but examples thereof include m-diamines, aminophenols, and diphenols. Specifically, the coupler may be one or more of resorcin, pyrogallol, catechol, m-aminophenol, m-phenylenediamine, o-aminophenol, 2,4-diaminophenol, 1,2,4-benzenetriol, toluene-3,4-diamine, toluene-2,4-diamine, hydroquinone, α-naphthol, 2,6-diaminopyridine, 1,5-dihydroxynaphthalene, 5-amino-o-cresol, diphenylamine, p-methylaminophenol, phloroglucin, 2,4-diaminophenoxyethanol, 2,4-diaminophenoxyethanol hydrochloride, gallic acid, tannic acid, ethyl gallate, methyl gallate, propyl gallate, quinella, 1-methoxy-2-amino-4-(2-hydroxyethyl)aminobenzene, 5-(2-hydroxyethylamino)-2-methylphenol, and salts thereof, which may be used in appropriate combination. The content of the coupler in the oxidation hair dye is not particularly limited, but is, for example, 0.01% by mass to 15% by mass. The lower limit is preferably 0.05% by mass or more, and more preferably 0.1% by mass or more. The upper limit is preferably 10% by mass or less, and more preferably 5% by mass or less. This allows for excellent hair dyeing effects.

[0020] <Alkaline agent> In the oxidative hair dye of the present invention, the first agent does not contain ammonia and monoethanolamine which are usually used as an alkaline agent. In this specification, "not containing" includes not containing the component at all and substantially not containing it. In the present invention, "substantially not containing" means containing the component in an amount that does not exhibit the effect of the component even if it contains the component. For example, "substantially not containing" ammonia and monoethanolamine in the first agent means that ammonia and monoethanolamine in the first agent do not act as an alkaline agent to change the pH of the oxidative hair dye, and when the oxidative hair dye is applied to the hair, it does not have the effect of opening the cuticle of the hair, for example, it contains 0.01% or less.

[0021] The alkaline agent is usually blended in the first agent, and has the effect of expanding the hair and promoting the penetration of the dye and oxidizing agent, imparting brightness to the hair, and adjusting the pH of the oxidation hair dye. In the oxidation hair dye of the present invention, the first agent does not contain ammonia and monoethanolamine, but may contain other alkaline agents. It has been revealed that alkaline agents other than ammonia and monoethanolamine affect the hair penetration of the dye and oxidizing agent, but do not affect the finger-feel as much as ammonia and monoethanolamine do. Therefore, in the oxidation hair dye of the present invention, the first agent may contain alkaline agents other than ammonia and monoethanolamine. In this specification, the alkaline agent refers to a component that has the effect of raising the pH of the oxidation hair dye to the alkaline side and opening the hair cuticle when the oxidation hair dye is applied to the hair. Specific examples of the alkaline agent include, but are not limited to, ammonia, alkanolamine, ammonium salt, silicate, metasilicate, phosphate, organic amines (2-amino-2-methyl-1,3-propanediol, guanidine, etc.), inorganic alkali (sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, etc.), basic amino acids (arginine, lysine, etc.) and their salts. Specific examples of alkanolamine include monoethanolamine, diethanolamine, triethanolamine, monopropanolamine, isopropanolamine, dipropanolamine, tripropanolamine, 2-amino-2-methyl-1,3-propanediol, 2-amino-2-methyl-1-propanol, 2-amino-2-hydroxymethyl-1,3-propanediol, etc. Specific examples of ammonium salts include ammonium halides, inorganic ammonium salts, organic ammonium salts, etc. Examples of ammonium halides include ammonium chloride, etc., examples of inorganic ammonium salts include ammonium carbonate, ammonium hydrogen carbonate, ammonium sulfate, ammonium phosphate, ammonium hydrogen phosphate, etc., and examples of organic ammonium salts include ammonium lactate, ammonium citrate, ammonium glycolate, etc. Specific examples of silicates include sodium silicate, potassium silicate, etc.Specific examples of metasilicates include sodium metasilicate, potassium metasilicate, etc. Specific examples of phosphates include ammonium diphosphate, ammonium diphosphate, disodium hydrogen phosphate, trisodium phosphate, etc. The amount of alkali agents other than ammonia and monoethanolamine is not particularly limited, but is preferably 10% by mass or less, more preferably 8% by mass or less.

[0022] By not containing an alkaline agent, the oxidative hair dye does not open the hair cuticle when applied to hair, and is therefore extremely effective in preventing hair damage. By not containing an alkaline agent in the first agent, the pH of the mixture becomes 6 to 8.5 when mixed with the second agent. On the other hand, conventional oxidative hair dyes containing an alkaline agent have a pH of 9.0 or higher.

[0023] The oxidation hair dye of the present invention may contain any component known in the art. In the oxidation hair dye of the present invention, the first and second agents may contain, for example, a direct dye, an oily component, a surfactant, a solvent, a hair protectant, an ultraviolet absorbing agent, and a fragrance. In addition to the above-mentioned components, the oxidative hair dye of the present invention may contain further components as necessary, for example, antioxidants such as anhydrous sodium sulfite, preservatives such as phenoxyethanol and sodium benzoate, sugars such as sorbitol and maltose, chelating agents such as ethylenediaminehydroxyethyltriacetate trisodium dihydrate and hydroxyethanediphosphonic acid tetrasodium solution, water-soluble polymers such as hydroxyethylcellulose and carboxyvinyl polymer, cationic water-soluble polymers such as polychlorinated dimethyldimethylene piperidinium solution (polychlorinated dimethyldimethylenepyrrolidinium solution) and diallyldimethylammonium chloride-hydroxyethylcellulose, acids such as citric acid, tartaric acid, lactic acid, malic acid, succinic acid, fumaric acid, maleic acid, pyrophosphoric acid, gluconic acid, glucuronic acid, hair growth components, plant extracts, herbal extracts, amino acids and peptides, urea, and vitamins.

[0024] <Direct dye> In the oxidation hair dye of the present invention, the first agent may contain a direct dye. The direct dye may be any dye known in the art, such as a basic dye, an acid dye, a nitro dye, or a disperse dye.

[0025] The basic dyes include, for example, basic blue 124, basic blue 75, basic purple 2, basic yellow 87, basic orange 31, Red No. 213, Red No. 214, basic blue 3, basic blue 6, basic blue 7, basic blue 9, basic blue 26, basic blue 41, basic brown 1, basic brown 4, basic brown 16, basic brown 17, basic orange 1, basic orange 2, basic red 1, basic red 2, basic red 22, basic red 46, basic red 51, basic red 76, basic red 118, basic purple 10, basic purple 11:1, basic purple 16, basic yellow 11, basic yellow 28, basic yellow 57, and basic yellow 87, and preferably basic blue 124, basic blue 75, basic purple 2, basic yellow 87, and basic orange 31. The basic dyes may be used alone or in combination.

[0026] Examples of acid dyes include Red No. 2, Red No. 3, Red No. 102, Red No. 104(1), Red No. 105(1), Red No. 106, Red No. 201, Red No. 227, Red No. 230(1), Red No. 230(2), Red No. 231, Red No. 232, Red No. 401, Red No. 502, Red No. 503, Red No. 504, Red No. 506, Yellow No. 4, Yellow No. 5, Yellow No. 202(1), Yellow No. 202(2), Yellow No. 203, Yellow No. 402, Yellow No. 403(1), Yellow No. 406, Yellow No. 407, Orange No. 205, Orange No. 20 No. 7, Orange No. 402, Green No. 3, Green No. 204, Green No. 205, Green No. 401, Green No. 402, Purple No. 401, Blue No. 1, Blue No. 2, Blue No. 202, Blue No. 203, Blue No. 205, Brown No. 201, Black No. 401, Acid Blue 1, Acid Blue 3, Acid Blue 62, Acid Black 52, Acid Brown 13, Acid Green 50, Acid Orange 6, Acid Red 14, Acid Red 35, Acid Red 73, Acid Red 184, and Brilliant Black 1.

[0027] Examples of nitro dyes include 4-nitro-o-phenylenediamine, 2-nitro-p-phenylenediamine, 2-amino-4-nitrophenol, 2-amino-5-nitrophenol, N,N'-bis(2-hydroxyethyl)-2-nitro-p-phenylenediamine, hydroxyethyl-2-nitro-p-toluidine, 2-amino-6-chloro-4-nitrophenol, 3-nitro-p-hydroxyethylaminophenol, 4-amino-3-nitrophenol, 4-hydroxypropylamino-3-nitrophenol, picramic acid, picric acid, and salts thereof, HC Blue 2, HC Blue 4, HC Blue 5, HC Blue 6, HC Blue 8, HC Blue 9, HC Blue 10, HC Blue 11, HC Blue 12, HC Blue 13, HC Blue 14, HC Blue 18, HC Blue 19, H C brown 1, HC brown 2, HC green 1, HC orange 1, HC orange 2, HC orange 3, HC orange 5, HC orange 7, HC red 1, HC red 3, HC red 7, HC red 8, HC red 9, HC Red 10, HC Red 11, HC Red 13, HC Red 14, HC Red 18, HC Purple 1, HC Purple 2, HC Purple 3, HC Yellow 2, HC Yellow 4, HC Yellow 5, HC Yellow 6, HC Yellow 7, HC Yellow 8, HC Yellow 9, HC Yellow 10, HC Yellow 11, HC Yellow 12, HC Yellow 13, HC Yellow 14, HC Yellow 15, HC Yellow 16, HC Yellow 18, etc.

[0028] Examples of disperse dyes include disperse black 9, disperse blue 1, disperse blue 3, disperse blue 7, disperse brown 4, disperse orange 3, disperse red 11, disperse red 15, disperse red 17, disperse purple 1, disperse purple 4, and disperse purple 15.

[0029] Other direct dyes that may be used include, for example, 1-amino-4-methylanthraquinone, 1,4-diaminoanthraquinone, and salts thereof, as well as direct dyes specified in the "Ministry Ordinance Specifying Tar Dyes That Can Be Used in Pharmaceuticals, etc." (Notification of 1966, Ministry of Health and Welfare).

[0030] Only one of these direct dyes may be contained alone, or two or more may be contained in combination. In addition, as the direct dye, in order to express a desired color, two or more direct dyes having complementary colors may be selected in combination.

[0031] The direct dye can be contained in any amount. For example, the direct dye can be contained in an amount of 0.001% by mass or more, preferably 0.005% by mass or more, more preferably 0.009% by mass or more, and 1% by mass or less, preferably 0.8% by mass or less, more preferably 0.7% by mass or less, of the total amount of the oxidation hair dye.

[0032] <Oily ingredients> The oxidation hair dye of the present invention may contain an oil component. The oil component may be any oil component known in the art, such as fats and oils, waxes, hydrocarbons, higher alcohols, higher fatty acids, alkyl glyceryl ethers, ester oils, silicones, and fluorine oils. One or more of these oil components may be selected and used.

[0033] In the oxidation hair dye of the present invention, the first agent may contain any of the oily components described above.

[0034] Fats and oils are triglycerides, i.e., triesters of fatty acids and glycerin. Specific examples of fats and oils include, for example, olive oil, rose hip oil, camellia oil, shea butter, macadamia nut oil, almond oil, tea seed oil, southernwood oil, safflower oil, sunflower oil, soybean oil, cottonseed oil, sesame oil, beef tallow, cocoa butter, corn oil, peanut oil, rapeseed oil, rice bran oil, rice germ oil, wheat germ oil, adzuki bean oil, grape seed oil, avocado oil, carrot oil, castor oil, linseed oil, palm oil, mink oil, egg yolk oil, evening primrose oil, and the like. Preferred fats and oils are olive oil, camellia oil, shea butter, grape seed oil, and evening primrose oil. The lower limit of the content of fats and oils in the oxidative hair dye is appropriately set, but is preferably 0.001% by mass or more, more preferably 0.005% by mass or more, and still more preferably 0.009% by mass or more. In particular, when the fat or oil is solid at 25°C, the lower limit of the content of the fat or oil in the first agent is preferably 1.0% by mass or more. The upper limit of the content of fats and oils in the oxidative hair dye is appropriately set, but is preferably 5% by mass or less, more preferably 2% by mass or less, and still more preferably 1% by mass or less. In particular, when the fat or oil is liquid at 25°C, the upper limit of the content of the fat or oil in the first agent is preferably 2% by mass or less.

[0035] Waxes are esters of higher fatty acids and higher alcohols. Specific examples of waxes include beeswax, candelilla wax, carnauba wax, jojoba oil, lanolin, whale wax, rice bran wax, sugarcane wax, palm wax, montan wax, cotton wax, bayberry wax, ivota wax, kapok wax, and shellac wax. Preferred waxes are beeswax, jojoba oil, and lanolin. The lower limit of the wax content in the oxidation hair dye is set appropriately, but is preferably 0.1 mass% or more, more preferably 0.15 mass% or more, and even more preferably 0.2 mass% or more. The lower limit of the wax content in the first agent is set appropriately, but is preferably 0.2 mass% or more, more preferably 0.3 mass% or more, and even more preferably 0.4 mass% or more. The upper limit of the wax content in the oxidation hair dye is set appropriately, but is preferably 5 mass% or less, more preferably 2 mass% or less, and even more preferably 1 mass% or less. The removal rate of the wax content in the first agent may be appropriately set, but is preferably 10% by mass or less, more preferably 4% by mass or less, and even more preferably 2% by mass or less.

[0036] Hydrocarbons are compounds consisting of carbon and hydrogen. Specific examples of hydrocarbon oils include liquid paraffin, paraffin, olefin oligomer, polyisobutene, hydrogenated polyisobutene, synthetic squalane, hydrogenated squalane, squalane, polybutene, polyethylene, microcrystalline wax, petrolatum, ozokerite, ceresin, limonene, and turpentine. Preferred hydrocarbons are liquid paraffin, paraffin, olefin oligomer, polyisobutene, hydrogenated polyisobutene, microcrystalline wax, and petrolatum. Among these, liquid paraffin, petrolatum, and microcrystalline wax are particularly preferred from the viewpoint of emulsion stability and operability. In addition, examples of isoparaffins include liquid isoparaffin and light liquid isoparaffin. Light liquid isoparaffin is generally a mixture of branched carbon compounds having 8 to 18 carbon atoms, and since it has a unique odor when it contains low molecular weight hydrocarbons, liquid isoparaffin is preferred among isoparaffins. The shape of the hydrocarbon is not particularly limited, but from the viewpoint of the ease of handling the oxidation hair dye on hair and the mixability of the oxidation hair dye, a liquid hydrocarbon at 25°C is preferred. The lower limit of the content of the hydrocarbon in the oxidation hair dye is appropriately set, but is preferably 0.5% by mass or more, more preferably 1.0% by mass or more, and even more preferably 1.8% by mass or more. The upper limit of the content of the hydrocarbon in the oxidation hair dye is appropriately set, but is 10% by mass or less, more preferably 8% by mass or less. When the content of the hydrocarbon is 0.5% by mass or more, the feel of the hair during rinsing and drying can be sufficiently improved. When the content of the hydrocarbon is 10% by mass or less, the ease of handling the oxidation hair dye on hair and the mixability can be further improved. The lower limit of the content of the hydrocarbon in the first agent is appropriately set, but is preferably 0.3% by mass or more, more preferably 0.6% by mass or more, and even more preferably 0.9% by mass or more.

[0037] The higher fatty acid is an aliphatic carboxylic acid having 6 or more carbon atoms. The number of carbon atoms of the higher fatty acid is not particularly limited, and is, for example, 6 or more and 24 or less. The lower limit is preferably 8 or more, more preferably 10 or more, and even more preferably 12 or more. On the other hand, the upper limit is preferably 22 or less, more preferably 20 or less, and even more preferably 18 or less. The carbon chain of the higher fatty acid may be saturated or unsaturated.

[0038] Specific examples of higher fatty acids include lauric acid, myristic acid, palmitic acid, stearic acid, behenic acid, isostearic acid, hydroxystearic acid, 12-hydroxystearic acid, undecylenic acid, oleic acid, linoleic acid, ricinoleic acid, lanolin fatty acid, etc. Preferred higher fatty acids are stearic acid and oleic acid.

[0039] The form of the higher fatty acid is not particularly limited, but it is preferably solid at 25°C. The content of the higher fatty acid in the oxidation hair dye is appropriately set, but from the viewpoint of improving the feel of the hair during rinsing and after drying, the lower limit of the content is preferably 0.1% by mass or more, more preferably 0.15% by mass or more, and even more preferably 0.25% by mass or more. The lower limit of the content of the higher fatty acid in the first agent is appropriately set, but is preferably 0.2% by mass or more, more preferably 0.3% by mass or more, and even more preferably 0.5% by mass or more. The upper limit of the content of the higher fatty acid in the oxidation hair dye is appropriately set, but is preferably 8% by mass or less, more preferably 4% by mass or less. The upper limit of the content of the higher fatty acid in the first agent is appropriately set, but is preferably 8% by mass or less.

[0040] The higher alcohol is not particularly limited, but is a compound having a hydroxyl group as a substituent on a linear, branched or cyclic hydrocarbon having 6 or more carbon atoms. A preferred higher alcohol is a linear higher alcohol. The number of hydroxyl groups in the higher alcohol is not particularly limited, and it may be a polyhydric alcohol having multiple hydroxyl groups, but is preferably a monohydric alcohol. The hydrocarbon of the higher alcohol may be either a saturated hydrocarbon or an unsaturated hydrocarbon. The higher alcohol may have a substituent other than a hydroxyl group. Examples of the higher alcohol used in the present invention include higher alcohols having less than 20 carbon atoms and higher alcohols having 20 or more carbon atoms. These higher alcohols may be blended alone or in combination of two or more. A preferred higher alcohol is a combination of higher alcohols having less than 20 carbon atoms and higher alcohols having 20 or more carbon atoms.

[0041] Specific examples of higher alcohols having less than 20 carbon atoms include lauryl alcohol, myristyl alcohol, cetyl alcohol (cetanol), stearyl alcohol, isostearyl alcohol, cetostearyl alcohol, decyl alcohol, oleyl alcohol, linoleyl alcohol, linolenyl alcohol, and 2-hexyldecanol. Preferred components are cetanol, stearyl alcohol, and cetostearyl alcohol. These higher alcohols having less than 20 carbon atoms may be blended alone or in combination of two or more.

[0042] Specific examples of higher alcohols having 20 or more carbon atoms include arachyl alcohol, behenyl alcohol, lanolin alcohol, 2-octyldodecanol, decyltetradecanol, phytosterol, cholesterol, etc. Preferred components are arachyl alcohol and behenyl alcohol. These higher alcohols having 20 or more carbon atoms may be blended alone or in combination of two or more.

[0043] The content of higher alcohol in the oxidation hair dye is appropriately set, for example, 0.1% by mass or more and 8.5% by mass or less. The lower limit is preferably 0.4% by mass or more, more preferably 0.6% by mass or more, even more preferably 0.8% by mass or more, and particularly preferably 1.0% by mass or more. On the other hand, the upper limit is preferably 8.2% by mass or less, more preferably 7.9% by mass or less, even more preferably 7.6% by mass or less, and particularly preferably 7.3% by mass or less.

[0044] The alkyl glyceryl ether is not particularly limited, and examples thereof include batyl alcohol, chimyl alcohol, selachyl alcohol, and isostearyl glyceryl ether. A preferred alkyl glyceryl ether is batyl alcohol. From the viewpoints of emulsion stability and operability, batyl alcohol is preferred. The content of the alkyl glyceryl ether in the oxidation hair dye is appropriately set, but from the viewpoint of improving the feel of the hair during rinsing and after drying, the lower limit of the content is 0.1% by mass or more, more preferably 0.15% by mass or more, and even more preferably 0.25% by mass or more. The upper limit of the content is preferably 8% by mass or less, and more preferably 4% by mass or less. The content of the alkyl glyceryl ether in the first agent is appropriately set, but the lower limit of the content is preferably 0.2% by mass or more, more preferably 0.3% by mass or more, and even more preferably 0.5% by mass or more. The upper limit of the content is preferably 16% by mass or less, and more preferably 8% by mass or less.

[0045] Ester oils are compounds obtained by the dehydration reaction of fatty acids and alcohols. Specific examples of ester oils include diisopropyl adipate, 2-hexyldecyl adipate, isopropyl myristate, myristyl myristate, octyldodecyl myristate, myristyl myristate, isotridecyl myristate, cetyl octanoate, cetyl isooctanoate, isononyl isononanoate, diisopropyl sebacate, isopropyl palmitate, 2-ethylhexyl palmitate, cetyl ethylhexanoate, butyl stearate, stearyl stearate, isostearyl ester, and ethylhexyl ester. Examples of the ester oil include isocetyl ester, hexyl laurate, decyl oleate, fatty acid (C10-30) (cholesteryl / lanosteryl), lauryl lactate, octyldodecyl lactate, octyldodecyl ricinoleate, cetyl lactate, lanolin acetate, pentaerythritol fatty acid ester, dipentaerythritol fatty acid ester, N-alkyl glycol monoisostearate, cetyl caprate, glyceryl tricaprylate, diisostearyl malate, dioctyl succinate, and hydrogenated castor oil isostearate. A preferred ester oil is cetyl ethylhexanoate. The form of the ester oil is not particularly limited, but from the viewpoint of improving the operability and mixability of the oxidation hair dye on hair, an ester oil that is liquid at 25°C is preferred. The content of the ester oil in the oxidation hair dye is appropriately set, but from the viewpoint of improving the feel of the hair, the lower limit of the content is preferably 0.1% by mass or more, more preferably 0.2% by mass or more, and even more preferably 0.5% by mass or more. The upper limit of the content is preferably 5% by mass or less, more preferably 4% by mass or less, and even more preferably 3% by mass or less. The lower limit of the content of the ester oil in the first agent is appropriately set, but is preferably 0.1% by mass or more. The upper limit of the content of the ester oil in the first agent is preferably 6% by mass or less.

[0046] Silicone is a synthetic polymer in which silicon with an organic group and oxygen are alternately linked by chemical bonds. Specific examples of silicone oils include dimethylpolysiloxane (dimethicone), dimethylpolysiloxane (dimethiconol) with a hydroxyl end group, methylphenylpolysiloxane, decamethylcyclopentasiloxane, dodecamethylcyclohexasiloxane, polyether-modified silicone, highly polymerized silicone with an average degree of polymerization of 650 to 10,000, amino-modified silicone, betaine-modified silicone, alkyl-modified silicone, alkoxy-modified silicone, mercapto-modified silicone, carboxy-modified silicone, and fluorine-modified silicone. Preferred silicone oils are dimethylpolysiloxane and amino-modified silicone.

[0047] Specific examples of the above amino-modified silicones include aminopropylmethylsiloxane-dimethylsiloxane copolymer (aminopropyl dimethicone), aminoethylaminopropylsiloxane-dimethylsiloxane copolymer (amodimethicone), aminoethylaminopropylmethylsiloxane-dimethylsiloxane copolymer (trimethylsilylamodimethicone), etc.

[0048] The content of silicone in the oxidation hair dye is appropriately set, but from the viewpoint of improving the feel of hair during rinsing and after drying, the lower limit of the content is preferably 0.2% by mass or more, more preferably 0.4% by mass or more, and even more preferably 0.8% by mass or more. The upper limit of the content is preferably 3% by mass or less, more preferably 2% by mass or less, and even more preferably 1% by mass or less. The lower limit of the content of silicone in the first agent is appropriately set, but is preferably 0.5% by mass or more. The upper limit of the content of silicone in the first agent is appropriately set, but is preferably 6% by mass or less, more preferably 4% by mass or less, and even more preferably 2% by mass or less.

[0049] In the oxidation hair dye, the content of the oily component in the first agent is not particularly limited, but is preferably 0.1% by mass to 20% by mass. The lower limit is more preferably 0.2% by mass or more, even more preferably 0.5% by mass or more, even more preferably 1% by mass or more, and particularly preferably 2% by mass or more. The upper limit is more preferably 18% by mass or less, even more preferably 16% by mass or less, even more preferably 14% by mass or less, and particularly preferably 12% by mass or less.

[0050] In the oxidation hair dye of the present invention, the second agent may contain an oil component that is liquid, pasty or solid at room temperature (25°C) except for higher alcohols. The liquid, pasty or solid oil component except for higher alcohols is not particularly limited, but specific examples include hydrocarbon oils, oils and fats, higher fatty acids, waxes, alkyl glyceryl ethers, ester oils, silicone oils, etc., which are exemplified as the oil components contained in the first agent above. From the viewpoint of more effectively exerting the effects of the present invention, preferred oil components are hydrocarbon oils and oils and fats. Particularly preferred are liquid paraffin, paraffin, petrolatum, and microcrystalline wax. Moreover, these oil components may be blended alone or in combination of two or more.

[0051] In the oxidative hair dye of the present invention, the second agent may contain 4% by mass or more of oily components excluding higher alcohols. The lower limit is more preferably 4.3% by mass or more, and even more preferably 4.6% by mass or more. The upper limit is preferably 20% by mass or less, more preferably 18% by mass or less, even more preferably 16% by mass or less, even more preferably 14% by mass or less, and particularly preferably 12% by mass or less. By containing 4% by mass or more of oily components excluding higher alcohols in the second agent, when the oxidative hair dye is applied to hair, the oxidative hair dye can have sufficient hair dyeing performance even if the oxidative hair dye is biased to the hair surface. Although the oxidative hair dye of the present invention does not dye the inside of the hair by biasing the hair surface, the hair dyeing power such as color development and fading performance is not inferior to that of conventional oxidative hair dyes containing an alkaline agent. In addition, the oxidative hair dye of the present invention does not destroy the melanin pigment of the hair to the inside by biasing the hair surface, so hair damage can be suppressed. In terms of color development and fading, it is desirable for the hair dye to penetrate deep into the hair; however, this does not normally occur when no alkaline agent is used. However, by including 4% by mass or more of an oily component in the second agent, even if the dye is concentrated on the surface of the hair, the dyeing power is not inferior to that of conventional oxidative hair dyes that contain alkaline agents.

[0052] In the oxidation hair dye of the present invention, the second agent may contain a higher alcohol. The lower limit of the content of the higher alcohol in the second agent is appropriately set, but is preferably 0.2% by mass or more, more preferably 0.3% by mass or more, and even more preferably 0.5% by mass or more. The upper limit of the content of the higher alcohol in the second agent is appropriately set, but is preferably 8% by mass or less.

[0053] <Oxidizing agent> In the oxidation hair dye of the present invention, the second agent contains an oxidizing agent. The oxidizing agent has the function of oxidizing the oxidation dye to develop color and decomposing melanin inside the hair. The oxidizing agent to be mixed in the second agent of the present invention may be any substance having oxidizing power, and is not particularly limited, but examples thereof include hydrogen peroxide, urea peroxide, melamine peroxide, sodium percarbonate, potassium percarbonate, sodium perborate, potassium perborate, ammonium persulfate, potassium persulfate, and other persulfates, sodium peroxide, potassium peroxide, magnesium peroxide, barium peroxide, calcium peroxide, strontium peroxide, hydrogen peroxide adducts of sulfates, hydrogen peroxide adducts of phosphates, hydrogen peroxide adducts of pyrophosphates, peracetic acid and its salts, performic acid and its salts, permanganates, and bromates. These oxidizing agents can be used alone or in combination of two or more. Among these oxidizing agents, hydrogen peroxide is preferred because of its excellent decolorizing power for melanin. In addition, persulfates such as ammonium persulfate, potassium persulfate, and sodium persulfate may be contained as an oxidation promoter.

[0054] The oxidation hair dye of the present invention does not contain ammonia and monoethanolamine in the first agent, and more preferably does not contain any other alkaline agent. Therefore, when the first agent is mixed with the second agent, which essentially contains hydrogen peroxide, the pH can be adjusted to 6 to 8.5. Therefore, damage to dyed hair can be prevented during dyeing.

[0055] The content of the oxidizing agent in the second agent is not particularly limited, but is preferably 0.1% by mass to 30% by mass, more preferably 1% by mass to 20% by mass. The content of the oxidizing agent in the oxidation hair dye is not particularly limited, but is, for example, 0.1% by mass to 15% by mass, more preferably 1% by mass to 9% by mass. It is preferable to contain hydrogen peroxide as the oxidizing agent, and the content of hydrogen peroxide in the second agent is not particularly limited, but is preferably 0.1% by mass to 30% by mass, more preferably 1% by mass to 20% by mass.

[0056] <Surfactant> In the oxidation hair dye of the present invention, the surfactant may be contained in both the first and second agents, or may be contained in either the first or second agent. Examples of the surfactant include anionic surfactants, cationic surfactants, nonionic surfactants, and amphoteric surfactants. In the following description, POE indicates a polyoxyethylene chain, POP indicates a polyoxypropylene chain, and the number in parentheses following it indicates the number of moles added. In addition, the number in parentheses following the alkyl indicates the number of carbon atoms in the fatty acid chain.

[0057] Examples of anionic surfactants include alkyl ether sulfates, POE alkyl ether sulfates, alkyl sulfates, alkenyl ether sulfates, alkenyl sulfates, olefin sulfonates, alkanesulfonates, saturated or unsaturated fatty acid salts, alkyl or alkenyl ether carboxylates, α-sulfonic acid salts, N-acylamino acid surfactants, phosphoric acid mono- or diester surfactants, and sulfosuccinic acid esters. The counter ion of the anionic group of these surfactants may be, for example, any of sodium ion, potassium ion, and triethanolamine.

[0058] More specifically, examples include sodium lauryl sulfate, sodium myristyl sulfate, potassium lauryl sulfate, ammonium lauryl sulfate, triethanolamine lauryl sulfate, sodium cetyl sulfate, sodium stearyl sulfate, sodium POE lauryl ether sulfate, triethanolamine POE lauryl ether sulfate, ammonium POE lauryl ether sulfate, sodium POE stearyl ether sulfate, sodium stearoyl methyl taurine, triethanolamine dodecylbenzenesulfonate, sodium tetradecenesulfonate, sodium lauryl phosphate, POE lauryl ether phosphate and its salts, N-lauroyl glutamate salts (sodium lauroyl glutamate, etc.), N-lauroyl methyl-β-alanine salt, N-acyl glycine salt, N-acyl glutamate salt, higher fatty acid lauric acid, myristic acid, and the salts of these higher fatty acids. One or more of these anionic surfactants can be used.

[0059] The content of the anionic surfactant in the oxidation hair dye is not particularly limited, but is preferably 0.01% by mass to 5% by mass. The lower limit is more preferably 0.03% by mass or more, even more preferably 0.05% by mass or more, even more preferably 0.07% by mass or more, and particularly preferably 0.1% by mass or more. The upper limit is more preferably 4% by mass or less, even more preferably 3% by mass or less, even more preferably 2.5% by mass or less, and particularly preferably 2% by mass or less. By setting the content of the anionic surfactant within the above range, the emulsion stability can be further improved.

[0060] Examples of cationic surfactants include alkyl quaternary ammonium salts such as monoalkyl-type quaternary ammonium salts, dialkyl-type quaternary ammonium salts, trialkyl-type quaternary ammonium salts, benzalkonium-type quaternary ammonium salts, and monoalkyl ether-type quaternary ammonium salts; amine salts such as alkylamine salts, fatty acid amide amine salts, ester-containing tertiary amine salts, and arcobel-type tertiary amine salts; cyclic quaternary ammonium salts such as alkylpyridinium salts and alkylisoquinolium salts; and benzethonium chloride.

[0061] Preferred are alkyl quaternary ammonium salts, more preferred are monoalkyl-type quaternary ammonium salts and dialkyl-type quaternary ammonium salts, and particularly preferred are monoalkyl-type quaternary ammonium salts.

[0062] Examples of monoalkyl quaternary ammonium salts include lauryl trimethyl ammonium chloride, lauryl trimethyl ammonium bromide, alkyl (16,18) trimethyl ammonium chloride, cetyl trimethyl ammonium chloride, cetyl trimethyl ammonium bromide, cetyl trimethyl ammonium saccharin, stearyl trimethyl ammonium chloride, stearyl trimethyl ammonium bromide, behenyl trimethyl ammonium chloride, stearyl trimethyl ammonium saccharin, alkyl (28) trimethyl ammonium chloride, diPOE (2) oleyl methyl ammonium chloride, diPOE stearyl methyl ammonium chloride, POE (1) POP (25) diethyl methyl ammonium chloride, POP methyl diethyl ammonium chloride, methacryloyloxyethyl trimethyl ammonium chloride, behenyl trimethyl ammonium methyl sulfate, etc. Particularly preferred are stearyl trimethyl ammonium chloride, alkyl (16,18) trimethyl ammonium chloride, and cetyl trimethyl ammonium chloride.

[0063] Examples of dialkyl-type quaternary ammonium salts include dialkyl(12-15)dimethylammonium chloride, dialkyl(12-18)dimethylammonium chloride, dialkyl(14-18)dimethylammonium chloride, dicocoyl dimethylammonium chloride, dicetyl dimethylammonium chloride, distearyl dimethylammonium chloride, and isostearyl lauryl dimethylammonium chloride.

[0064] The content of the cationic surfactant in the oxidation hair dye is not particularly limited, but is preferably 0.01 to 10% by mass. The lower limit is more preferably 0.03% by mass or more, even more preferably 0.05% by mass or more, even more preferably 0.07% by mass or more, and particularly preferably 0.1% by mass or more. The upper limit is more preferably 7.5% by mass or less, even more preferably 5% by mass or less, even more preferably 3% by mass or less, and particularly preferably 1.5% by mass or less. By setting the content of the cationic surfactant within the above range, it is possible to further improve the emulsion stability.

[0065] Examples of nonionic surfactants include POE alkyl ethers, POE alkyl phenyl ethers, POE·POP alkyl ethers, POE sorbitan fatty acid esters, POE mono fatty acid esters, POE glycerin fatty acid esters, polyglycerin fatty acid esters, monoglycerin fatty acid esters, sorbitan fatty acid esters, sucrose fatty acid esters, alkyl polyglucosides, etc. Specific examples of POE alkyl ethers include POE lauryl ether, POE cetyl ether, POE stearyl ether, POE behenyl ether, POE lanolin, POE phytosterol, etc. The number of repeating units of POE and POP is, for example, 2 to 100, and any one that exhibits a surface active effect can be used.

[0066] The content of the nonionic surfactant in the oxidation hair dye is not particularly limited, but is preferably 0.001% by mass to 30% by mass. The lower limit is more preferably 0.01% by mass or more, even more preferably 0.05% by mass or more, even more preferably 0.1% by mass or more, and particularly preferably 0.2% by mass or more. The upper limit is more preferably 20% by mass or less, even more preferably 10% by mass or less, even more preferably 7% by mass or less, and particularly preferably 5% by mass or less. By setting the content of the nonionic surfactant within the above range, the emulsion stability can be further improved.

[0067] Examples of the amphoteric surfactant include amino acid type amphoteric surfactants and betaine type amphoteric surfactants.

[0068] Specific examples of the amino acid type amphoteric surfactant include sodium N-lauroyl-N'-carboxymethyl-N'-hydroxyethyl ethylenediamine (sodium lauroamphoacetate), 2-alkyl-N-carboxymethyl-N-hydroxyethyl imidazolinium betaine, sodium undecyl hydroxyethyl imidazolinium betaine, alkyl diaminoethyl glycine hydrochloride, sodium N-coconut oil fatty acid acyl-N'-carboxyethyl-N'-hydroxyethyl ethylenediamine, sodium N-coconut oil fatty acid acyl-N'-carboxyethoxyethyl-N glycine type amphoteric surfactants such as N-coconut oil fatty acid acyl-N'-carboxymethoxyethyl-N'-carboxymethylethylenediamine disodium, sodium lauryl diaminoethyl glycine, and palm oil fatty acid acyl-N-carboxyethyl-N-hydroxyethylethylenediamine sodium; aminopropionic acid type amphoteric surfactants such as sodium lauryl aminopropionate, sodium lauryl aminodipropionate, and triethanolamine lauryl aminopropionate; and the like.

[0069] Specific examples of betaine-type amphoteric surfactants include aminoacetic acid betaine-type amphoteric surfactants such as coconut oil alkyl betaine, lauryl dimethylaminoacetic acid betaine, myristyl dimethylaminoacetic acid betaine, stearyl dimethylaminoacetic acid betaine, sodium stearyl dimethyl betaine, coconut oil fatty acid amidopropyl betaine, palm oil fatty acid amidopropyl betaine, lauric acid amidopropyl betaine, ricinoleic acid amidopropyl betaine, and stearyl dihydroxyethyl betaine; and sulfobetaine-type amphoteric surfactants such as lauryl hydroxysulfobetaine.

[0070] The content of the amphoteric surfactant in the oxidation hair dye is not particularly limited, but is preferably 0.001% by mass to 5% by mass. The lower limit is more preferably 0.005% by mass or more, even more preferably 0.01% by mass or more, still more preferably 0.05% by mass or more, and particularly preferably 0.1% by mass or more. The upper limit is more preferably 3% by mass or less, and even more preferably 2.5% by mass or less. By setting the content of the amphoteric surfactant within the above range, it is possible to further improve the emulsion stability.

[0071] The total content of all surfactants in the oxidation hair dye is not particularly limited, but is preferably 0.01% by mass to 50% by mass. The lower limit is more preferably 0.05% by mass or more, and even more preferably 0.1% by mass or more. The upper limit is more preferably 40% by mass or less, and even more preferably 30% by mass or less.

[0072] <Solvent> The oxidation hair dye of the present invention may contain a solvent such as water, such as purified water, ethanol, or a polyhydric alcohol. Specific examples of polyhydric alcohols include glycol and glycerin. These polyhydric alcohols may be used alone or in combination of two or more. Specific examples of glycols include ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, polyethylene glycol (for example, PEG400, PEG1000, PEG1500, PEG1540, etc.), polypropylene glycol, isoprene glycol, and 1,3-butylene glycol. Specific examples of glycerin include glycerin, diglycerin, and polyglycerin. These solvents may be used alone or in combination of two or more.

[0073] <Chelating agent> Chelating agents include, but are not limited to, ethylenediaminetetraacetic acid (EDTA, edetic acid), hydroxyethylethylenediaminetriacetic acid (HEDTA) and its salts, diethylenetriaminepentaacetic acid and its salts, and hydroxyethanediphosphonic acid (HEDP, etidronic acid) and its salts.

[0074] <Dosage form> The dosage forms of the first and second agents are not particularly limited and can be any dosage form known in the art. Specific examples of the dosage forms of the first and second agents at 25°C include liquids such as aqueous solutions and emulsions, gels, foams, creams, and solids. The dosage forms of the first and second agents can be aerosols, non-aerosols, and other dosage forms, and in the case of non-aerosols, they can take various forms such as squeeze foamers and pump foamers. In the case of aerosols, known propellants and foaming agents can be applied. In the case of solid dosage forms, a dispersant may be added.

[0075] The mixing ratio of the first agent and the second agent of the two-agent type oxidation hair dye is appropriately set in consideration of the concentration, mixability, application method, etc. of each component in the mixture of the oxidation hair dye, but is preferably 0.1 to 10:1, more preferably 0.5 to 2:1. The formulation of the oxidation hair dye is not particularly limited as long as it is a formulation that can be applied to hair, and specific examples of the formulation at 25°C include liquids such as aqueous solutions and emulsions, gels, foams, and creams. From the viewpoint of ease of application with a brush, improved spreadability and adhesion to hair, and excellent application operability, it is preferable to make it cream or paste-like. In addition, the oxidation hair dye may be further made into a foam or mist. When making it into the foam mentioned above, it may be formed by self-foaming by mixing the oxidation hair dye in a mixing container and a mixing tool, or the oxidation hair dye may be filled into a shaking container and foamed by shaking, or a known foaming device such as a non-aerosol foamer or an aerosol foamer may be used.

[0076] The oxidation hair dye may be applied to hair using an applicator such as a comb, brush, paintbrush, applicator, etc. Alternatively, the oxidation hair dye may be applied to hair using gloved hands.

[0077] The oxidation hair dye is not limited to a two-component type, and may be configured as a three-component type or more by configuring some of the components contained in the first and second components as separate components. For example, the first component of a two-component type may be divided into two components: one containing the oxidation dye and an optional alkaline agent, and the other component having the other components, to configure a three-component oxidation hair dye. In this case, the emulsion stability is further improved.

[0078] Even if the oxidation hair dye is a composition of three or more components or a composition containing a powdered agent, it is still included in the present invention as long as it exhibits the effects of the present invention.

[0079] As described above, in the oxidative hair dye of the present invention, the second agent may contain 4% by mass or more of an oily component other than higher alcohol. In the oxidative hair dye of the present invention, even when the second agent does not contain 4% by mass or more of an oily component other than higher alcohol, the hair surface is dyed unevenly, but by containing 4% by mass or more of an oily component other than higher alcohol in the second agent, the hair dyeing performance is improved. Although the oxidative hair dye of the present invention dyes the hair surface unevenly, and the inside of the hair is not dyed, the hair dyeing power such as color development and fading performance is not inferior to that of conventional oxidative hair dyes containing an alkaline agent. In addition, the oxidative hair dye of the present invention can have sufficient hair dyeing performance even if the hair surface is dyed unevenly. By dyeing the hair surface unevenly, the melanin pigment of the hair is not destroyed to the inside, and hair damage can be suppressed. By including 4% by weight or more of oily ingredients other than higher alcohols in the second agent, the hair dye becomes superior to oxidative hair dyes that contain less than 4% by weight of oily ingredients other than higher alcohols in evaluations including hair dyeing power, color fading prevention performance, color transfer (towel transfer), and hair damage (fingers running through the hair).

[0080] The present invention also provides a hair dyeing method, comprising the steps of: preparing an oxidative hair dye by mixing a first agent containing an oxidative dye and not containing ammonia and monoethanolamine with a second agent containing an oxidizing agent; applying the oxidative hair dye to hair; and rinsing the oxidative hair dye after dyeing the hair.

[0081] In the present invention, applying the hair dye to hair includes painting, spraying, applying, and treating the hair with the hair dye, and includes any means for contacting the hair with the hair dye.

[0082] The first agent containing an oxidation dye and not containing ammonia or monoethanolamine, and the second agent containing an oxidizing agent are each prepared to contain the above-mentioned components. When used, the first agent and the second agent are mixed to prepare the oxidation hair dye.

[0083] The oxidative hair dye is applied to the hair immediately after mixing the first and second agents. The oxidative hair dye can be applied to the hair by any means. For example, the oxidative hair dye may be applied to the hair by hand using a gloved hand, or may be applied to the hair using a comb or the like. The first and second agents may be simultaneously discharged and applied to the hair without mixing, so that the two agents are mixed on the hair. After application, the hair is left for a predetermined time. The time for leaving the hair after application can be appropriately adjusted, and can be, for example, 5 minutes or more, 15 minutes or more, or 20 minutes or more, and is preferably 10 minutes or more. Also, the time can be, for example, 60 minutes or less, 55 minutes or less, or 50 minutes or less, and is preferably 55 minutes or less.

[0084] The oxidative hair dye may also be washed after dyeing by any means, for example by rinsing the hair with water.

[0085] According to the hair dyeing method of the present invention, by applying an oxidative hair dye agent that does not contain an alkaline agent to hair, the pH of the oxidative hair dye agent can be adjusted to 6 to 8.5, and hair damage can be suppressed while obtaining hair dyeing power that is not inferior to conventional oxidative hair dye agents. Furthermore, by containing 4% by mass or more of an oily component other than higher alcohol in the second agent, the hair dyeing power can be further improved. EXAMPLES

[0086] The present invention will be described in more detail below with reference to examples and comparative examples relating to the oxidation hair dye of the present invention, but the present invention is not limited to these examples and comparative examples.

[0087] <How to measure pH of oxidation hair dye> The method for measuring the pH of the oxidative hair dye is as follows. Measurements were made using a glass electrode type hydrogen ion concentration indicator (type: SS056, model: F-52) manufactured by Horiba Estech Co., Ltd. The pH was measured 2 minutes after the start of mixing the first and second agents as the pH immediately after mixing. Specifically, the first and second agents were quickly mixed, the mixture was transferred to a measuring device, and the detector was immersed in the mixture to measure the pH 2 minutes after the start of mixing. All of the oxidative hair dyes in Examples 1 to 4 and Comparative Examples 1 and 2 were in a cream formulation, and the first and second agents were mixed using a brush or the like.

[0088] <Production of oxidation hair dye> The first and second agents were prepared by mixing the components shown in the following Tables 1, 2, and 3. Table 1 shows the names and amounts of each component in the base part of the first agent. The same composition of the base part of the first agent was used for all of the components in Examples 1 to 4 and Comparative Examples 1 and 2.

[0089] [Table 1]

[0090] Table 2 shows the names and amounts of the components of the dye part, alkali part and second part used in the first pack for each of Examples 1 and 2 and Comparative Examples 1 and 2.

[0091] For the first agents of Examples 1 and 2 and Comparative Examples 1 and 2, the column for "total of first agent" shows the sum of the blending amount of each component of the base part of the first agent in Table 1 and the blending amount of each component shown in Table 2 as the total of the first agent (100%). The column for "total of second agent" shows the sum of the blending amount of each component shown in Table 2 as the total of the second agent (100%). The column for "mixed pH" shows the pH when the first agent and the second agent are mixed at a ratio of 1:1. The column for "evaluation" shows the evaluation of each of the hair dyeing power, browning inhibition performance, dye transfer, finger smoothness, and hair penetration (surface, interior), and the numerical values ​​shown in each row show the evaluation by a specialist panelist.

[0092] [Table 2]

[0093] In Table 3, for the first agents of Examples 3 and 4 and Comparative Examples 1 and 2, the column for "total of first agent" lists the total of the blending amount of each component of the base part of the first agent in Table 1 and the blending amount of each component shown in Table 3 as the total of the first agent (100%). In addition, the column for "total of second agent" lists the total of the blending amount of each component shown in Table 3 as the total of the second agent (100%). In addition, the column for "mixed pH" lists the pH when the first agent and the second agent are mixed. In addition, the column for "evaluation" lists the evaluation of each of the hair dyeing power, browning inhibition performance, dye transfer, finger run, and hair penetration (surface, interior), and the numerical values ​​shown in each row indicate the evaluation by a specialist panelist.

[0094] [Table 3]

[0095] The oxidation hair dye compositions produced in Examples 1 to 4 and Comparative Examples 1 and 2 were subjected to a hair dyeing process according to the following procedure, and the hair dyeing power, browning inhibition performance, dye transfer (towel transfer), hair damage (finger run), and hair penetration (surface, interior) were evaluated.

[0096] (Hair dye treatment) For the oxidation hair dyes of Examples 1 to 4 and Comparative Examples 1 and 2, the first and second agents were mixed in a mass ratio of 1:1 to prepare a mixture of the oxidation hair dyes of each example. 3 g of the mixture obtained was applied to 1 g of a 10 cm long white hair bundle sample (manufactured by Bealux) for evaluation (hereinafter simply referred to as a hair bundle) using a brush. After the mixture was applied to the hair bundle, it was left at 30°C, and after 10 minutes, the mixture attached to the hair bundle was washed off with water, and the hair bundle was shampooed twice (Bigen Treatment Shampoo manufactured by Hoyu Co., Ltd.) and rinsed once (Bigen Treatment Rinse manufactured by Hoyu Co., Ltd.). The hair bundle was then dried with hot air to obtain a dyed hair bundle of each example.

[0097] (Method for evaluating hair dyeing power) The dyeing ability of each dyed hair bundle was evaluated the day after the dyeing process according to the method described below. Ten expert panelists visually evaluated the degree of color development of each dyed hair bundle under a standard light source and judged whether the color development was good or not according to the following criteria. (Evaluation criteria for hair dyeing ability) 5: Very well dyed 4: Well dyed 3: Dyed 2: Not very dyed 1: Almost no dye The scores were scored on a 5-point scale. The average of the scores from each expert panelist was calculated, and the evaluation results were determined as follows: 4.6 points or more was "excellent: 5", 3.6 points or more but less than 4.6 points was "good: 4", 2.6 points or more but less than 3.6 points was "fair: 3", 1.6 points or more but less than 2.6 points was "slightly poor: 2", and less than 1.6 points was "poor: 1". The results are shown in the "Hair dyeing power" column in Tables 2 and 3.

[0098] (Method for evaluating anti-fading performance) In the above-mentioned method for evaluating hair dyeing power, the dyed hair bundles were washed 10 times with shampoo after treatment with the oxidative hair dye, and then 10 expert panelists visually evaluated the fading inhibition effect (color retention) under a standard light source. The fading inhibition effect was evaluated according to the following criteria. The results are shown in the "fading inhibition performance" column in Tables 2 and 3. (Evaluation criteria for anti-fading performance) 5: Excellent anti-fading effect 4. Excellent anti-fading effect 3: Good anti-fading effect 2: Poor anti-fading effect 1: Very poor anti-fading effect The scores of each expert panelist were averaged, and the evaluation results were determined as follows: 4.6 points or more was "excellent: 5", 3.6 points or more but less than 4.6 points was "good: 4", 2.6 points or more but less than 3.6 points was "fair: 3", 1.6 points or more but less than 2.6 points was "slightly poor: 2", and less than 1.6 points was "poor: 1".

[0099] (Method of evaluating dye transferability) For the oxidation hair dyes of Examples 1 to 4 and Comparative Examples 1 and 2, the first and second agents were mixed at a mass ratio of 1:1 to prepare a mixture of the oxidation hair dyes of each example. 3 g of the mixture obtained was applied to 1 g of a 10 cm long white hair bundle sample (manufactured by Bealux) for evaluation (hereinafter simply referred to as a hair bundle) using a brush and left for 10 minutes at 30°C. Thereafter, the mixture attached to the hair bundle was washed off with water, and the hair bundle was shampooed twice (Bigen Treatment Shampoo manufactured by Hoyu Co., Ltd.) and rinsed once (Bigen Treatment Rinse manufactured by Hoyu Co., Ltd.).

[0100] The treated hair bundle was then sandwiched between white cotton cloth for JIS dye fastness testing (JIS L0803 compliant) and a load of 5 kg was applied to the cotton cloth. One minute after the load was applied, the degree of staining on the cotton cloth was visually observed by 10 panelists and evaluated according to the following criteria. The average of the scores of the 10 panelists was rounded off to the nearest whole number and used as the evaluation score for the oxidation hair dye used in each example. The results are shown in the "Dye transfer (towel transfer)" column in Tables 2 and 3. (Evaluation criteria for dye transfer) 5: Dirt is very hard to see 4: Dirt is not noticeable 3: Dirt is barely noticeable 2: Dirt is noticeable 1: Dirt is very noticeable.

[0101] (Evaluation method for hair damage (fingers running through)) For the oxidation hair dye compositions produced in Examples 1 to 4 and Comparative Examples 1 and 2, dyed hair strands were obtained according to the procedure described in (Hair dyeing treatment).

[0102] Ten panelists performed a sensory evaluation of the combability of each dyed hair bundle. The control was an undyed hair bundle that had been shampooed twice (Bigen Treatment Shampoo, manufactured by Hoyu Co., Ltd.) and rinsed once (Bigen Treatment Rinse, manufactured by Hoyu Co., Ltd.) (undyed hair control). Each panelist compared each evaluation sample with the undyed hair control and scored it on a five-point scale: "very good combability: 5 points," "good combability: 4 points," "same combability: 3 points," "poor combability: 2 points," and "very bad combability: 1 point." The average score of each panelist's scores was calculated. This was used as the evaluation result. The results are shown in the "Hair Damage (Comfortability)" column in Tables 2 and 3. (evaluation) 5: Average score is 3.5 or higher 4: Average score is between 3.0 and 3.5 3: Average score is between 2.5 and 3.0 2: Average score is between 2.0 and 2.5 1: Average score below 2.0

[0103] (Evaluation method for hair permeability (surface, interior)) For the oxidation hair dye compositions produced in Examples 1 to 4 and Comparative Examples 1 and 2, dyed hair strands were obtained according to the procedure described in (Hair dyeing treatment).

[0104] For each dyed hair bundle, the hair was cut into 20 μm thick pieces using a microtome, and the cross sections were observed under a microscope. As a result of the observation, each panelist scored the results according to the following criteria. ○: Hair is dyed to a depth of 10% to less than 50% from the outside to the inside △: Hair is dyed to a depth of 50% to 75% from the outside to the inside ×: Hair is dyed to a depth of 75% or more from the outside to the inside The results are shown in the "Hair Penetration (Surface, Interior)" column in Tables 2 and 3. Note that depth refers to the depth range % measured from the surface to the center of the hair along the major axis passing through the center of the cross section of the hair, with the surface being 0% and the center being 100%.

[0105] As shown in Table 2, the first agents of the oxidation hair dyes of Example 1 and Example 2 both do not contain ammonia and monoethanolamine. On the other hand, the first agents of the oxidation hair dyes shown in Comparative Example 1 and Comparative Example 2 contain ammonia and monoethanolamine, respectively. The oxidation hair dyes of Example 1 and 2 were both good in terms of the evaluation of hair dyeing power, brown color suppression performance, migration property, and hair damage.

[0106] On the other hand, the oxidation hair dyes of Comparative Example 1 and 2 received the lowest evaluation in terms of the evaluation as described. From the components of the oxidation hair dyes of Example 1 and 2 and Comparative Example 1 and 2, it can be seen that when ammonia and monoethanolamine are not contained, the feel is significantly improved, and when no alkali agent other than ammonia and monoethanolamine is contained, the feel is further improved.

[0107] Although the oxidation hair dyes of Example 1 and 2 according to the present invention do not contain ammonia and monoethanolamine, they were able to suppress hair damage without affecting the hair dyeing power, brown color suppression performance, and migration property. In addition, the oxidation hair dye of Example 1 was evaluated to be dyed by 10% or more and less than 50% from the outside to the inside of the hair after hair dyeing, indicating that the hair dye remained on the surface of the hair. That is, the oxidation hair dye of Example 1 is unevenly dyed on the hair surface, so it does not destroy the melanin pigment inside the hair, and thus can suppress hair damage.

[0108] As shown in Table 3, the first agents of the oxidation hair dyes of Example 3 and Example 4 both do not contain ammonia and monoethanolamine. On the other hand, the first agents of the oxidation hair dyes shown in Comparative Example 1 and Comparative Example 2 contain ammonia and monoethanolamine, respectively.

[0109] The oxidative hair dyes of Examples 3 and 4 according to the present invention, although not containing ammonia and monoethanolamine, were able to suppress hair damage without affecting hair dyeing power, browning inhibition performance, and dye transferability. In addition, the oxidative hair dyes of Examples 3 and 4 were evaluated as dyeing 10% or more but less than 50% of the hair from the outside to the inside after dyeing, and it can be seen that the hair dye remains on the surface of the hair. That is, the oxidative hair dyes of Examples 3 and 4 are unevenly dyed on the hair surface, and do not destroy the melanin pigment of the hair to the inside, so that hair damage can be suppressed. In addition, when Examples 3 and 4 are compared, it can be seen that the hair dyeing power is further improved by containing 4% or more of liquid paraffin (oil-based component other than higher alcohol) as the second agent component as in Example 3. Furthermore, Example 3 was evaluated as being superior to Example 4, which contains only 3% liquid paraffin, in all evaluations including fading inhibition performance, dye transferability (towel transfer), and hair damage (fingers). Therefore, it can be seen that all evaluations improve when the second agent contains 4% or more of oily ingredients other than higher alcohols. [Industrial Applicability]

[0110] The oxidative hair dye of the present invention can be used as a hair dye for dyeing human body hair such as head hair, beard, eyebrows, and leg hair. The oxidative hair dye of the present invention may also be used for dyeing body hair of animals such as pets. The oxidative hair dye of the present invention can be used as a hair dye for coloring in beauty salons, barber shops, etc., and as a hair dye for self-coloring.

Claims

1. An oxidation hair dye obtained by mixing a first agent containing an oxidation dye but not containing ammonia or monoethanolamine with a second agent containing an oxidizing agent.

2. The oxidation hair dye according to claim 1, characterized in that the first agent does not contain an alkaline agent, the pH of the mixture becomes 6 to 8.5 when the first agent and the second agent are mixed, and the oxidation hair dye is not a cumulative type hair dye.

3. The oxidative hair dye according to claim 1 or 2, wherein the oxidative hair dye is applied to hair so that the hair surface is unevenly dyed.

4. 4. The oxidation hair dye according to claim 3, wherein the second agent contains 4% by mass or more of an oil component excluding higher alcohols in the second agent.

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