Acid dyeing composition

Abstract

To provide an acidic hair dye composition capable of imparting uniform dyeing properties to gray hair.SOLUTION: An acidic hair dye composition of the present invention comprises at least one kind of an acid dye (A) selected from Yellow No. 4, Yellow No. 203, and Orange No. 205, and is applied to gray hair.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to an acidic hair dye composition applied to gray hair.

Background Art

[0002] Generally, an acidic hair dye composition containing an acidic dye as a hair cosmetic composition is known. The acidic hair dye composition causes the dye to be ionically bonded to a very shallow portion of the cortex from the cuticle of the hair under acidic conditions to develop color. Therefore, the acidic hair dye composition has the merit that it can suppress damage to the hair compared to oxidative hair dyes.

[0003] By the way, a new trend of calling the natural color tone gray hair without dyeing white hair is increasing. Gray hair is completed by becoming white hair from which hair pigments have completely fallen out, but due to the accumulation of damage such as ultraviolet rays and heat, discoloration such as yellowing of the hair tips occurs, and there has been a problem that the hair color looks uneven and impairs the aesthetics. It has not been easy to give aesthetics to gray hair having an uneven hair color by dyeing it light with an acidic hair dye composition.

[0004] Conventionally, an acidic hair dye composition disclosed in Patent Document 1 has been known. Patent Document 1 discloses a hair whitening agent containing a water-soluble compound exhibiting a purple color such as Violet No. 401 as a main pigment and used for color correction of yellowed white hair.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

[0007] This invention is based on the discovery that, in an acidic hair dye composition applicable to gray hair, uniform dyeing properties can be imparted to gray hair by using a predetermined type of acidic dye. Note that the mass percentage values ​​indicating the content of the components include the solubilizer such as water in the dosage form.

[0008] The following describes various methods for solving the above problems. The acidic hair dye composition of Embodiment 1 contains at least one acidic dye (A) selected from Yellow No. 4, Yellow No. 203, and Orange No. 205, and is intended for use on gray hair.

[0009] Embodiment 2 is an acidic hair dye composition according to Embodiment 1, wherein the mass ratio of the total content of acidic dyes (A) Yellow No. 4, Yellow No. 203, and Orange No. 205 to the total content of all acidic dyes in the acidic hair dye composition is 0.1 or more.

[0010] Embodiment 3 is an acidic hair dye composition according to Embodiment 1 or 2, wherein the total content of all acidic dyes in the acidic hair dye composition is 0.005% by mass or more and 0.05% by mass or less. [Effects of the Invention]

[0011] According to the present invention, it is possible to impart uniform dyeing properties to gray hair. [Modes for carrying out the invention]

[0012] The following describes one embodiment of the acidic hair dye composition of the present invention. The acidic hair dye composition of this embodiment comprises at least one acidic dye (A) selected from Yellow No. 4, Yellow No. 203, and Orange No. 205, and is applied to gray hair.

[0013] (Acid dye (A)) Acid dyes (A) are formulated to color hair. Acid dyes are non-reactive and capable of developing color on their own. In this invention, at least one acid dye selected from Yellow No. 4, Yellow No. 203, and Orange No. 205 is included as an essential dye. By including these yellow-based acid dyes, uniform coloring can be provided to gray hair. These acid dyes (A) may be used individually or in combination of two or more types.

[0014] The acidic hair dye composition of this embodiment may also contain acidic dyes other than those listed above. Specific examples of other acidic dyes include, for example, 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. 5, Yellow No. 202 (1), Yellow No. 202 (2), Yellow No. 402, Yellow No. 403 (1), Yellow No. 406, Yellow No. 407, Orange No. 207, Orange No. 40 Examples include No. 2, 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, Brilliant Black 1, etc. Among these, it is preferable to include at least one acid dye selected from Black No. 401, Purple No. 401, and Red No. 227 as other acid dyes, and it is more preferable to include Red No. 227. By combining black No. 401, purple No. 401, or red No. 227 with the essential acid dyes yellow No. 4, yellow No. 203, or orange No. 205, more uniform dyeing properties can be achieved for gray hair.

[0015] These acid dyes may be used individually or in combination of two or more types. The final color of the dyed hair is not particularly limited, but yellow, silver, and pink tones are preferred, with yellow tones being more preferred. The dye can color the roots to mid-lengths of the hair, blending in yellowish gray hair and creating a uniform hair color. This results in a natural-looking finish for the entire hair, enhancing its aesthetic appeal. Yellow tones include shades such as yellow, ochre, gold, grayish-yellow, and beige.

[0016] The lower limit of the mass ratio of the total acid dye content of Yellow No. 4, Yellow No. 203, and Orange No. 205 to the total acid dye content in the acidic hair dye composition is set as appropriate, but is preferably 0.1 or higher, more preferably 0.3 or higher, and even more preferably 0.5 or higher. When such a mass ratio is 0.1 or higher, the color derived from Yellow No. 4, Yellow No. 203, or Orange No. 205 can be effectively imparted to the hair, and gray hair can be given a more uniform dyeing effect.

[0017] The upper limit of the total mass ratio of the acidic dyes Yellow No. 4, Yellow No. 203, and Orange No. 205 to the total acidic dye content in the acidic hair dye composition is set as appropriate, but is preferably 0.95 or less, more preferably 0.9 or less, and even more preferably 0.8 or less. When such a mass ratio is 0.95 or less, it reduces excessively yellowish tones, thereby creating an aesthetically pleasing appearance for gray hair.

[0018] The lower limit of the total acid dye content in the acidic hair dye composition is set as appropriate, but is preferably 0.005% by mass or more, more preferably 0.01% by mass or more. When the total acid dye content is 0.005% by mass or more, the dyeing power can be further improved. On the other hand, the upper limit of the total acid dye content is set as appropriate, but is preferably 0.05% by mass or less, more preferably 0.047% by mass or less, and even more preferably 0.045% by mass or less. When the total acid dye content is 0.05% by mass or less, appropriate dyeing properties can be imparted to gray hair.

[0019] (Aromatic alcohol) The acid hair dye composition may contain an aromatic alcohol if necessary from the viewpoint of improving the hair dyeing power. Specific examples of the aromatic alcohol include, for example, benzyl alcohol, 2-phenylethyl alcohol, cinnamyl alcohol, phenylpropanol, 1-phenoxy-2-propanol, phenyldiglycol, α-methylbenzyl alcohol, dimethylbenzyl carbinol, benzyloxyethanol, phenoxyethanol, phenoxyisopropanol, p-anisyl alcohol and the like. These aromatic alcohols may be used alone or in combination of two or more. From the viewpoint of better hair dyeing power, benzyl alcohol and benzyloxyethanol are preferred among these.

[0020] The lower limit of the content of the aromatic alcohol in the acid hair dye composition is appropriately set, but is preferably 0.1% by mass or more, more preferably 1% by mass or more. When the content of the aromatic alcohol is 0.1% by mass or more, the hair dyeing power can be further improved. On the other hand, the upper limit of the content of the aromatic alcohol is appropriately set, but is preferably 30% by mass or less, more preferably 20% by mass or less. When the content of the aromatic alcohol is 30% by mass or less, the effect of preventing the ground fabric from being soiled by the acid hair dye composition can be improved.

[0021] (pH adjuster) The pH adjuster may be formulated to adjust the pH of the acid hair dye composition. Examples of the pH adjuster include, in addition to alkaline agents, inorganic acids, organic acids, salts thereof and the like. Specific examples of the alkaline agent include, for example, ammonia, alkanolamine, silicate, carbonate, hydrogen carbonate, metasilicate, sulfate, chloride, phosphate, organic amine, basic amino acid, hydroxide of an alkali metal or an alkaline earth metal and the like.

[0022] Specific examples of inorganic acids include, for example, phosphoric acid, hydrochloric acid, nitric acid, sulfuric acid, boric acid, etc. Further specific examples of phosphoric acid include, for example, orthophosphoric acid, polyphosphoric acid, pyrophosphoric acid, metaphosphoric acid, etc. Specific examples of organic acids include, for example, pyrrolidone carboxylic acid, citric acid, glycolic acid, tartaric acid, lactic acid, malic acid, levulinic acid, succinic acid, fumaric acid, oxalic acid, maleic acid, gluconic acid, mandelic acid, glucuronic acid, acetic acid, butyric acid, valeric acid, benzoic acid, etc. Specific examples of salts include, for example, sodium salts, potassium salts, ammonium salts, etc. These pH adjusters may be only one type, or two or more types may be used in combination.

[0023] The content of the pH adjuster in the acid hair dye composition is preferably an amount such that the pH of the acid hair dye composition is in the range of 2 or more and 8 or less, more preferably in the range of 3 or more and 7 or less, and even more preferably in the range of more than 3 and 5 or less. When the pH of the acid hair dye composition is 2 or more, it can improve the dye stability and reduce the color tone change due to long-term storage even when the amount of the acid dye in the acid hair dye composition is small. When the pH is 8 or less, it can improve the hair dyeing power. The pH of the acid hair dye composition is measured at 25 °C when the acid hair dye composition is dissolved in water at a concentration of 10% by mass.

[0024] (Other components) The acid hair dye composition may further contain, if necessary, components other than the aforementioned components, for example, solubilizers other than the above, penetration promoters other than the above, water-soluble polymers, oily components, surfactants, chelating agents, sugars, preservatives, stabilizers, plant extracts, crude drug extracts, vitamins, fragrances, antioxidants, ultraviolet absorbers, etc.

[0025] Other solubilizers are added, for example, to adjust the properties of the acidic hair dye composition. Examples of solubilizers used include water and organic solvents. Organic solvents may also be added to further improve the dyeing power of the acidic dye. Specific examples of organic solvents include monohydric lower alcohols, glycols and glycerins as polyhydric alcohols, and diethylene glycol lower alkyl ethers. Specific examples of monohydric lower alcohols include methanol, ethanol, propanol, isopropanol, etc. Specific examples of glycols include diethylene glycol, triethylene glycol, dipropylene glycol, isoprene glycol, hexylene glycol, 1,3-butylene glycol, etc. Specific examples of glycerins include glycerin, diglycerin, polyglycerin, etc. Specific examples of diethylene glycol lower alkyl ethers include diethylene glycol monoethyl ether (ethyl carbitol), etc. Only one of these solubilizers may be included alone, or two or more may be included in combination. Among these, water is preferred because it has excellent ability to dissolve other components in the acidic hair dye composition. When water is used as the solvent, the water content in the acidic hair dye composition (content at the time of use) is preferably 40% by mass or more, and more preferably 50% by mass or more.

[0026] Other penetration enhancers may be added to improve the hair dyeing power of acid dyes. Examples of penetration enhancers include monohydric alcohols with 4 to 8 carbon atoms, ethylene glycol alkyl ethers, and cyclic alcohols. Specific examples of monohydric alcohols with 4 to 8 carbon atoms include n-butanol, isobutanol, n-pentanol, n-hexanol, n-heptanol, and n-octanol. Specific examples of ethylene glycol alkyl ethers include ethylene glycol mono-n-butyl ether. Specific examples of cyclic alcohols include cyclohexanol. These may be used individually or in combination of two or more.

[0027] Water-soluble polymer compounds provide an appropriate viscosity to the acidic hair dye composition. Therefore, the acidic hair dye composition may contain water-soluble polymer compounds within a range that does not hinder the effects of the present invention. Examples of water-soluble polymer compounds include natural polymers, semi-synthetic polymers, synthetic polymers, and inorganic polymers. Specific examples of natural water-soluble polymer compounds include guar gum, locust bean gum, quince seed, carrageenan, galactan, gum arabic, tragacanth gum, pectin, mannan, xanthan gum, dextran, succinoglucan, curdlan, hyaluronic acid, gelatin, casein, albumin, collagen, and dextrin.

[0028] Specific examples of semi-synthetic water-soluble polymer compounds include, for example, methylcellulose, ethylcellulose, hydroxyethylcellulose, hydroxyethylcellulose dimethyldiallylammonium chloride, hydroxypropylcellulose, carboxymethylcellulose, carboxymethylcellulose sodium, hydroxypropylmethylcellulose, cationized cellulose, cationized guar gum, starch phosphate esters, propylene glycol alginate esters, and alginates.

[0029] Specific examples of synthetic water-soluble polymer compounds include, for example, polyvinyl caprolactam, polyvinyl alcohol (PVA), polyvinylpyrrolidone (PVP), vinylpyrrolidone-vinyl acetate (VP / VA) copolymer, polyvinyl butyral, polyvinyl methyl ether, carboxyvinyl polymer, sodium polyacrylate, polyacrylamide, polyethylene oxide, ethylene oxide-propylene oxide block copolymer, acrylic acid / alkyl acrylate copolymer, polydimethylmethylenepiperidinium chloride, polyethylene glycol, and high-polymer polyethylene glycol. Specific examples of synthetic polymers include, for example, a semi-ester of itaconic acid and polyoxyethylene (hereinafter referred to as "POE") alkyl ether, or a copolymer consisting of an ester of methacrylic acid and POE alkyl ether and at least one monomer selected from acrylic acid, methacrylic acid, and their alkyl esters. Only one of these water-soluble polymer compounds may be included individually, or two or more may be included in combination.

[0030] Oily components provide moisture to the hair. Therefore, the acidic hair dye composition may contain oily components to the extent that it does not hinder the effects of the present invention. Examples of oily components include oils and fats, waxes, higher alcohols, hydrocarbons, higher fatty acids, alkyl glyceryl ethers, esters, and silicones.

[0031] Specific examples of fats and oils include, for example, argania spinosa kernel oil, lanolin, olive oil, camellia oil, shea butter, almond oil, safflower oil, sunflower oil, soybean oil, cottonseed oil, sesame oil, corn oil, rapeseed oil, rice bran oil, rice germ oil, grape seed oil, avocado oil, macadamia nut oil, castor oil, coconut oil, evening primrose oil, etc. Specific examples of waxes include, for example, beeswax, candelilla wax, carnauba wax, jojoba oil, lanolin wax, etc. Specific examples of higher alcohols include, for example, cetyl alcohol (cetanol), 2-hexyldecanol, stearyl alcohol, isostearyl alcohol, cetostearyl alcohol, oleyl alcohol, arachidodecanol, behenyl alcohol, 2-octyldodecanol, lauryl alcohol, myristyl alcohol, decyltetradecanol, lanolin alcohol, etc.

[0032] Specific examples of hydrocarbons include paraffin, olefin oligomers, polyisobutene, hydrogenated polyisobutene, mineral oil, squalane, polybutene, polyethylene, microcrystalline wax, and petrolatum. Specific examples of higher fatty acids include lauric acid, myristic acid, palmitic acid, stearic acid, behenic acid, isostearic acid, 12-hydroxystearic acid, oleic acid, and lanolin fatty acids. Specific examples of alkyl glyceryl ethers include batyl alcohol, chymyl alcohol, ceracyl alcohol, and isostearyl glyceryl ether.

[0033] Specific examples of esters include, for example, diisopropyl adipate, isopropyl myristate, cetyl octanoate, isononyl isononanoate, octyldodecyl myristate, isopropyl palmitate, stearyl stearate, myristyl myristate, isotridecyl myristate, 2-ethylhexyl palmitate, octyldodecyl ricinoleate, cholesteryl / lanosteryl fatty acids with 10 to 30 carbon atoms, cetyl lactate, lanolin acetate, ethylene glycol di-2-ethylhexanoate, pentaerythritol fatty acid esters, dipentaerythritol fatty acid esters, cetyl caprate, glyceryl tricaprylate, diisostearyl malate, dioctyl succinate, and cetyl 2-ethylhexanoate.

[0034] Specific examples of silicones include, for example, dimethylpolysiloxane (dimethicone), methylphenylpolysiloxane, decamethylcyclopentasiloxane, dodecamethylcyclohexasiloxane, hydroxyl-terminated dimethylpolysiloxane, highly polymerized silicones, polyether-modified silicones (e.g., (PEG / PPG / butylene / dimethicone) copolymer), amino-modified silicones, betaine-modified silicones, alkyl-modified silicones, alkoxy-modified silicones, mercapto-modified silicones, carboxy-modified silicones, and fluorine-modified silicones. Of these oily components, only one may be included individually, or two or more may be included in combination.

[0035] Surfactants, acting as emulsifiers or solubilizers for each component, emulsify or solubilize the acidic hair dye composition at the time of use, thereby adjusting viscosity or improving viscosity stability. Therefore, the acidic hair dye composition may contain surfactants within a range that does not hinder the effects of the present invention. Examples of surfactants include anionic surfactants, cationic surfactants, amphoteric surfactants, and nonionic surfactants.

[0036] Specific examples of anionic surfactants include alkyl ether sulfates, alkyl sulfates, alkyl ether sulfate esters, alkenyl ether sulfates, alkenyl sulfates, olefin sulfonates, alkanesulfonates, saturated or unsaturated fatty acid salts, alkyl or alkenyl ether carboxylates, α-sulfone fatty acid salts, N-acyl amino acid type surfactants, phosphate mono or diester type surfactants, sulfosuccinate esters, and their derivatives. Specific examples of counterions for the anionic groups of these surfactants include sodium ions, potassium ions, and triethanolamine. More specifically, an example of alkyl ether sulfate ester is sodium POE lauryl ether sulfate. Specific examples of alkyl sulfates include sodium lauryl sulfate and sodium cetyl sulfate. Specific examples of alkyl sulfate derivatives include sodium POE lauryl sulfate. Specific examples of sulfosuccinate esters include disodium lauryl sulfosuccinate.

[0037] Specific examples of cationic surfactants include, for example, lauryltrimethylammonium chloride, cetyltrimethylammonium chloride, stearyltrimethylammonium chloride, alkyltrimethylammonium chloride, distearyldimethylammonium chloride, cetyltrimethylammonium bromide, stearyltrimethylammonium bromide, lanolin fatty acid aminopropylethyldimethylammonium ethyl sulfate, stearyltrimethylammonium saccharin, cetyltrimethylammonium saccharin, methacryloyloxyethyltrimethylammonium chloride, and behenyltrimethylammonium methyl sulfate.

[0038] Specific examples of amphoteric surfactants include, for example, cocobetaine, lauramidopropyl betaine, cocamidopropyl betaine, sodium lauroamphoacetate, sodium cocoamphoacetate, coconut oil fatty acid amidopropyl betaine, and lauryl betaine (lauryldimethylaminoacetate betaine).

[0039] Specific examples of nonionic surfactants include ether-type nonionic surfactants, ester-type nonionic surfactants, and alkyl glucosides. Specific examples of ether-type nonionic surfactants include POE cetyl ether (ceteth), POE stearyl ether (steareth), POE behenyl ether, POE oleyl ether (oleth), POE lauryl ether (laureth), POE octyldodecyl ether, POE hexyldecyl ether, POE isostearyl ether, POE nonylphenyl ether, and POE octylphenyl ether.

[0040] Specific examples of ester-type nonionic surfactants include, for example, POE sorbitan monooleate, POE sorbitan monostearate, POE sorbitan monopalmitate, POE sorbitan monolaurate, POE sorbitan trioleate, POE glycerin monostearate, POE glycerin monomyristate, POE sorbitan tetraoleate, POE sorbitan hexastearate, POE sorbitan monolaurate, POE sorbitan beeswax, polyethylene glycol monooleate, and polyethylene monostearate. Examples include polyethylene glycol, polyethylene glycol monolaurate, lipophilic glyceryl monooleate, lipophilic glyceryl monostearate, self-emulsifying glyceryl monostearate, sorbitan monooleate, sorbitan sesquioleate, sorbitan trioleate, sorbitan monostearate, sorbitan monopalmitate, sorbitan monolaurate, sucrose fatty acid esters, decaglyceryl monolaurate, decaglyceryl monostearate, decaglyceryl monooleate, decaglyceryl monomyristate, and the like.

[0041] Specific examples of alkyl glucosides include alkyl (8-16 carbon atoms) glucoside, POE methyl glucoside, and POE dioleate methyl glucoside. Of these specific examples of surfactants, only one may be included individually, or two or more may be included in combination.

[0042] Chelating agents may be added to further improve hair dyeing power. Specific examples of chelating agents include, for example, edetate (ethylenediaminetetraacetic acid (EDTA)), disodium edetate, tetrasodium edetate, diethylenetriaminepentaacetic acid and its salts, hydroxyethylethylenediaminetriacetic acid and its salts, and hydroxyethanediphosphonic acid (HEDP) and its salts. These may be used individually or in combination of two or more.

[0043] Specific examples of sugars include monosaccharides such as glucose and galactose, disaccharides such as maltose, sucrose, fructose, and trehalose, and sugar alcohols. Specific examples of preservatives include parabens, methylparaben, and sodium benzoate. Specific examples of stabilizers include phenacetin, 8-hydroxyquinoline, acetanilide, sodium pyrophosphate, barbiturates, uric acid, and tannic acid. Specific examples of antioxidants include ascorbic acid and sulfites.

[0044] The dosage form of the acidic hair dye composition is not particularly limited, and specific examples include liquid, gel, foam, and cream. Examples of liquid forms include aqueous solutions, dispersions, and emulsions. Furthermore, from the viewpoint of improving storage stability, the acidic hair dye composition may be configured to be stored separately as a solid component and a liquid component, and mixed immediately before use.

[0045] (Gray hair) The acidic hair dye composition of this embodiment is applied to gray hair. Gray hair refers to hair that is a mixture of gray and black hair, and does not use hair dye that completely hides the gray hair, but rather a style that uses hair color that makes use of the gray hair and adds a light tint to the gray hair. The degree of gray hair is known to range from a "first gray" state where gray hair is visible to the naked eye (less than 10%) to a state where 90% of the hair is gray and it looks almost entirely gray.

[0046] The acidic hair dye composition of this embodiment can improve the appearance of gray hair, particularly gray hair that has discolored, such as yellowing at the ends, due to the accumulation of damage from ultraviolet rays and heat, by dyeing it a light color without over-dyeing it. From the viewpoint of effectively exhibiting this effect, it is preferably applied to gray hair with a degree of grayness of 10% or more, more preferably 20% or more, and even more preferably 30% or more.

[0047] The effects of the acidic hair dye composition of this embodiment will now be explained. (1) The acidic hair dye composition of this embodiment is applied to gray hair and is configured to contain at least one acidic dye (A) selected from Yellow No. 4, Yellow No. 203, and Orange No. 205. Therefore, it can provide uniform dyeing properties, especially to gray hair where discoloration such as yellowing has occurred at the ends due to the accumulation of damage such as ultraviolet rays and heat.

[0048] In particular, when dyeing hair with yellow, silver, or pink tones, dyeing the roots to mid-lengths of the hair helps to blend in yellowed gray hairs and create a uniform hair color. This results in a natural-looking color throughout the hair, enhancing its aesthetic appeal.

[0049] The above embodiment may be modified as follows. The above embodiment and the following modifications can be combined and implemented to the extent that they do not contradict each other technically. In the above embodiment, the acidic hair dye composition was formulated as a single-component formula containing all of its components. However, the components may be separated and formulated into multiple components, which are then mixed immediately before use.

[0050] The acidic hair dye composition of the above embodiment is configured as a semi-permanent hair dye composition containing an acidic dye (A). The product form of the semi-permanent hair dye composition is not particularly limited and may be, for example, a hair manicure, color treatment, color rinse, or acidic color. Hair manicures or acidic colors are hair dyes that dye the hair to the desired color in a single dyeing process. On the other hand, color treatments and color rinses are decolorizing hair dyes that are applied to the hair through daily hair care, etc., and as a result of repeated dyeing treatments, gradually dye the hair to the desired color. The acidic hair dye composition of the above embodiment can give an aesthetic appearance by dyeing gray hair to a light color that does not dye it too dark, so it is preferable to apply it as a decolorizing hair dye as a color treatment or color rinse. [Examples]

[0051] Next, the embodiments described above will be explained in more detail with reference to examples and comparative examples. It should be noted that the present invention is not limited to the configurations described in the Examples section. Acidic hair dye compositions for each example and comparative example were prepared by mixing the components shown in Tables 1 and 2. Next, white hair bundles (G goat hair, 10 cm long, manufactured by Staffs Co., Ltd., hereinafter simply referred to as hair bundles) were prepared. Hair bundles for dyeing tests were prepared by applying a hair iron heated to 220°C to the ends of the hair bundles for 10 seconds to cause discoloration such as yellowing at the ends of the hair bundles.

[0052] Each acidic hair dye composition was applied to the hair strands with a brush, left at 30°C for 5 minutes, and then treated twice with regular shampoo (Hoyu Co., Ltd.: Bigen Treatment Shampoo). The hair strands were then dried to obtain the first dyed hair strands. The same process was repeated two more times to obtain a total of three dyed hair strands.

[0053] The uniformity and aesthetic appearance of the dyed hair strands were evaluated. The evaluation results are shown in Tables 1 and 2. The units of the numerical values ​​indicating the composition of each component in the tables are in mass percent. In addition, the notation (A) in the "Component" column of the tables indicates the compound corresponding to the component described in the claim of this application.

[0054] (uniformity) Ten panelists visually observed hair strands from each case after dyeing under a standard light source to determine whether uniform dyeing was achieved in hair strands where discoloration such as yellowing of the ends occurred due to the acidic hair dye composition of each case. A five-point scale was used to evaluate the uniformity of dyeing: "Excellent: 5" if eight or more panelists responded that the uniformity of dyeing was good, "Good: 4" if six to seven people, "Acceptable: 3" if four to five people, "Somewhat Poor: 2" if two to three people, and "Poor: 1" if one or fewer people. The results of this evaluation are shown in the "Uniformity" column of Tables 1 and 2.

[0055] (Aesthetics) Ten panelists visually observed hair strands from each case after dyeing under a standard light source to determine whether the hair strands, which had discolored at the ends due to the acidic hair dye composition in each case, had achieved a natural overall color and aesthetically pleasing results. A five-point scale was used to evaluate the results: "Excellent: 5" if eight or more panelists considered the results aesthetically pleasing, "Good: 4" if six to seven panelists, "Acceptable: 3" if four to five panelists, "Somewhat Poor: 2" if two to three panelists, and "Poor: 1" if one or fewer panelists considered the results aesthetically pleasing. The evaluation results are shown in the "Aesthetic Appearance" column in Tables 1 and 2.

[0056] [Table 1]

[0057] [Table 2] As shown in Table 1, each example was confirmed to have a result of "acceptable" or better in terms of uniformity and aesthetics. In Example 2, the content ratio of acid dye (A) in the total acid dye was slightly high, resulting in a tendency for the yellowness to be slightly stronger and the aesthetics to be slightly lower. In Examples 3, 6-8, the content ratio of acid dye (A) in the total acid dye was slightly low, resulting in a tendency for the yellowness to be slightly weaker and the uniformity and aesthetics to be slightly lower. In Example 4, the total acid dye content was slightly low, resulting in a tendency for the color to be slightly lighter and the uniformity and aesthetics to be slightly lower. In Example 5, the total acid dye content was slightly high, resulting in a tendency for the color to be slightly darker and the aesthetics to be slightly lower.

[0058] As shown in Table 2, Comparative Example 1, which did not contain acid dye (A) but contained Red 227 and Black 401, resulted in poor uniformity as the color was applied to the yellowed areas. In addition, the uneven application of Red 227 and Black 401 resulted in a reduced aesthetic appearance. Comparative Example 2, which did not contain acid dye (A) but contained Violet 401, resulted in poor uniformity as the color was applied to the yellowed areas. Comparative Example 3, which did not contain acid dye (A) but contained Red 227, resulted in poor uniformity and aesthetic appearance as the color was applied to the yellowed areas. Comparative Example 4, which did not contain acid dye (A) but contained Black 401, resulted in poor uniformity as the color was applied to the yellowed areas. In addition, the color mixed with the damaged, yellowed ends of the hair, causing the ends to turn green and reducing the aesthetic appearance. Comparative Example 5, which did not contain acid dye (A) but contained Blue 1, resulted in poor uniformity as the color was applied to the yellowed areas. Furthermore, the damaged, yellowed ends of the hair mixed with the color, resulting in the ends turning green and a reduced aesthetic appearance. Comparative Example 6, which did not contain acid dye (A) but contained Green No. 204, showed that the yellowing was colored, resulting in poor uniformity and aesthetic appearance.

[0059] Next, the technical ideas that can be understood from the above embodiments and alternative examples are added below: (a) The acidic hair dye composition applied as a color treatment or color rinse. (b) The acidic hair dye composition that dyes hair to a yellow, silver, or pink color.

Claims

1. An acidic hair dye composition of the rinse-off type, comprising at least one acidic dye (A) selected from Yellow No. 4, Yellow No. 203, and Orange No. 205, and an aromatic alcohol, wherein the total content of all acidic dyes in the acidic hair dye composition is 0.005% by mass or more and 0.05% by mass or less, and is an acidic hair dye composition for use on gray hair to dye it a light color.

2. The acidic hair dye composition according to claim 1, wherein the mass ratio of the total content of acidic dyes (A) Yellow No. 4, Yellow No. 203, and Orange No. 205 to the total content of all acidic dyes in the acidic hair dye composition is 0.1 or more.

3. An acidic hair dye composition comprising at least one acidic dye (A) selected from Yellow No. 203 and Orange No. 205, and an aromatic alcohol, wherein the total content of all acidic dyes in the acidic hair dye composition is 0.005% by mass or more and 0.05% by mass or less, and is a rinse-off type acidic hair dye composition that is applied to gray hair.

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