Non-oxidative hair dye

Abstract

To provide a non-oxidative hair dye that can be readily applied, allows stable preparation of a second agent containing a metal salt, and does not show a deterioration of its dyeing effect even when mixed before use.SOLUTION: A non-oxidative hair dye at least contains: an acidic first agent containing at least laccaic acid out of the substances that react with metal salts for coloring; and an acidic second agent containing a metal salt. The hair dye has been mixed before use. The second agent contains an organic acid and carrageenan.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a non-oxidative hair dye, and more specifically to a non-oxidative hair dye that includes at least a first agent and a second agent, which are mixed before use. [Background technology]

[0002] Hair dyes used to dye hair include temporary hair dyes, semi-permanent hair dyes, and permanent hair dyes. Of these, permanent hair dyes are the most widely used due to their high dyeing properties and ability to prevent color fading after dyeing. A common permanent hair dye is an oxidation hair dye, which consists of a first agent containing an oxidation dye and an alkaline agent, and a second agent containing an oxidizing agent. These oxidation hair dyes are easy to use because the first and second agents are mixed together before use.

[0003] However, oxidative hair dyes are said to have safety issues, not only because they damage hair due to the effects of alkaline and oxidizing agents, but also because some oxidative dyes may cause allergic reactions. Therefore, non-oxidative hair dyes, which utilize the reaction of polyphenols such as tannin, gallic acid, and laccaic acid with metal salts, have been proposed as highly safe hair dyeing methods that cause less damage to hair and do not cause allergic reactions (see, for example, Patent Documents 1 to 5).

[0004] Many of these non-oxidative hair dyes have a mechanism for developing color by reacting on the hair between polyphenols contained in a first agent, which is prepared mainly in the neutral range, and metal salts contained in a second agent, which is prepared mainly in the acidic range. That is, to achieve better dyeing effects, a treatment method using separate application of agents is adopted, in which the first agent containing polyphenols is applied to the hair, and after leaving it for a certain period of time, the second agent containing metal salts is applied to the hair to promote the reaction and dye the hair.

[0005] Therefore, conventional non-oxidative hair dyes have the disadvantage of being less convenient in the application process than oxidative hair dyes. Furthermore, due to the unique color-developing mechanism described above, when pre-mixed as with oxidative hair dyes, the polyphenols and metal salts react with each other and develop color immediately upon mixing, resulting in poor dyeing effects on the hair. Therefore, it has been very difficult to pre-mix conventional non-oxidative hair dyes before use. In addition, to pre-mix and use, the pH of the second agent containing the metal salt must be in the acidic range, similar to that of the first agent. However, in the acidic range, color development is poor, making it difficult to achieve the desired hair color. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Publication No. 05-170629 [Patent Document 2] Japanese Patent Application Publication No. 07-069850 [Patent Document 3] Japanese Patent Application Laid-Open No. 2004-353150 [Patent Document 4] Japanese Patent Application Laid-Open No. 2005-029550 [Patent Document 5] Japanese Patent Application Laid-Open No. 2014-009160 Summary of the Invention [Problem to be solved by the invention]

[0007] The present invention has been made in consideration of the above-mentioned conventional technology, and aims to provide a non-oxidizing hair dye that is easy to use, has a second agent containing a metal salt with good formulation stability, and does not adversely affect the dyeing effect even when mixed in advance for use. [Means for solving the problem]

[0008] That is, the present invention provides a non-oxidative hair dye that comprises at least an acidic first agent containing at least laccaic acid among substances that react with metal salts to produce color, and an acidic second agent containing a metal salt, which are mixed at the time of use, and the second agent is characterized in that it contains an organic acid and carrageenan.

[0009] The content of the laccaic acid is preferably 0.5 to 4% by mass.

[0010] It is preferable that the pH of the first agent is in the range of 1.8 to 5, and the pH of the second agent is in the range of 1.8 to 5.

[0011] The non-oxidative hair dye of the present invention is preferably used to conceal gray hair. [Effects of the Invention]

[0012] Unlike conventional non-oxidative hair dye application methods, the non-oxidative hair dye of the present invention does not require each agent to be left for a certain period of time after application, but is mixed in advance for use, thereby shortening the application time and reducing the time and effort required for the application itself, thereby demonstrating significantly superior effects in terms of simplicity.

[0013] Furthermore, the non-oxidative hair dye of the present invention is formulated so that the metal salt contained in the second agent reacts gently with the substance that reacts with the metal salt contained in the first agent to produce color, even when mixed in advance, and therefore has the effect of not adversely affecting the dyeing and providing a good dyeing effect. DETAILED DESCRIPTION OF THE INVENTION

[0014] The non-oxidative hair dye of the present invention is a non-oxidative hair dye that comprises at least an acidic first agent containing at least laccaic acid among substances that react with metal salts to produce color, and an acidic second agent containing metal salts, and is mixed at the time of use, and is characterized in that the second agent contains an organic acid and carrageenan.

[0015] Each component used in the non-oxidative hair dye of the present invention will be described in detail below.

[0016] The first agent of the non-oxidative hair dye of the present invention contains a substance that reacts with a metal salt to develop color. By using these substances, hair can be dyed safely without damaging it.

[0017] The present invention is characterized by using laccaic acid, among the above substances, as an essential component. Laccaic acid is very useful as a component for dyeing gray hair brown to black depending on the amount of laccaic acid added. However, depending on the pH range to be adjusted, it has the drawback of being poor in dyeing properties and not being able to achieve the desired dyeing effect.

[0018] The laccaic acid may be a commercially available product, such as Neo Red F (trade name, manufactured by Nippon Shellac Kogyo Co., Ltd.).

[0019] The content of laccaic acid in the first agent of the non-oxidative hair dye of the present invention is not particularly limited as long as the desired effect is sufficiently exhibited. However, to exhibit a good dyeing effect, it is preferably 0.5% by mass or more, more preferably 1% by mass or more, based on 100% by mass of the first agent. A content of less than 0.5% by mass is not preferred because it results in inferior dyeing effect. Furthermore, to suppress precipitation of laccaic acid itself and maintain the stability of the formulation, it is preferably 4% by mass or less, more preferably 3% by mass or less, based on 100% by mass of the first agent. No difference in color development effect is observed even if more than 4% by mass is incorporated. Note that the content of laccaic acid mentioned above is the amount converted to pure content.

[0020] Examples of the components other than laccaic acid include organic compounds that react with metal salts to develop color, plant extracts that react with metal salts to develop color, etc. These substances that react with metal salts to develop color may be used alone or in combination of two or more.

[0021] Specific examples of the organic compounds include tannic acid, gallic acid, octyl gallate, propyl gallate, alizarin, isoquercetin, persimmon tannin, catechol, gallotannin, quercetin, curcumin, getidine, tetrahydropalmatine, palmatine, 2-hydroxy-1,4-naphthoquinone, 5-hydroxy-1,4-naphthoquinone, pyrogallol, phenanthraquinone, brazilin, phloroglucin, hematein, berberine, etc. These organic compounds may be used alone or in appropriate combination of two or more.

[0022] Specific examples of the plant extract include red grape, Mallotus japonicus, madder root, Acacia oleracea, oolong tea, turmeric, pitcher plant, Uva-ursi, Scutellaria root, Phellodendron bark, Coptis chinensis, giant knotweed, St. John's wort, Phellodendron amurense, walnut, cinnamon bark, gentian, German herb, black tea, watercress, Scutellaria baicalensis, Oriental jasmine, Chinese gallnut, pomegranate, hawthorn, ash, peony, yew, honeysuckle, Sappan, yarrow, senna, clove, Houttuynia cordata, elderberry, holly tree, terrestris, betel nut, coltsfoot, Brazilwood, henna, tree peony, mulberry, balsam tree, angelica tree, melissa, bayberry, saxifrage, green tea, astragalus, rosemary, and logwood. These plant extracts may be used singly or in appropriate combination of two or more.

[0023] In the present invention, in order to achieve a good dyeing effect, it is preferable to use an organic compound among the substances that react with the above-mentioned metal salts to produce color, in addition to the above-mentioned laccaic acid, and in order to enhance the dyeing effect, it is more preferable to use at least one selected from tannic acid, gallic acid, curcumin, and hematein among these organic compounds.

[0024] Commercially available products can be used as the substance that reacts with the metal salt to develop a color. Commercially available tannic acid products include, for example, Tannic Acid (trade name, manufactured by Fuji Chemical Industry Co., Ltd.). Commercially available gallic acid products include, for example, Gallic Acid (trade name, manufactured by DSS Co., Ltd.). Commercially available curcumin products include, for example, S-Color Yellow UI (trade name, manufactured by Maruzen Pharmaceutical Co., Ltd.). Commercially available hematein products include, for example, Hematein Ichimaru (trade name, manufactured by Ichimaru Pharcos Co., Ltd.).

[0025] The content of the substance that reacts with the metal salt other than laccaic acid to develop color in the first agent of the non-oxidative hair dye of the present invention is not particularly limited as long as the desired effect is sufficiently achieved. However, to achieve a good dyeing effect, it is preferably 0.05% by mass or more, more preferably 0.1% by mass or more, based on 100% by mass of the first agent. Furthermore, to ensure safety, it is preferably 2% by mass or less, more preferably 1.5% by mass or less, based on 100% by mass of the first agent. The content of the substance that reacts with the metal salt to develop color is the amount converted to a pure content. It also refers to the total content of the substance that reacts with the metal salt other than laccaic acid to develop color, which is blended in the first agent of the non-oxidative hair dye of the present invention.

[0026] It is preferable that the first agent of the non-oxidative hair dye of the present invention contains a penetrating agent, from the viewpoint of allowing the substance that reacts with the metal salt to develop color to penetrate into the interior of the hair and exerting an excellent dyeing effect.

[0027] Examples of the penetrating agent that can be used include monohydric alcohols having 3 to 8 carbon atoms, aromatic alcohols, cyclic alcohols, N-alkylpyrrolidones, alkylene carbonates, etc. These penetrating agents may be used alone or in appropriate combination of two or more.

[0028] Specific examples of the penetrant include monohydric alcohols having 2 to 8 carbon atoms, such as butanol, isobutanol, pentanol, hexanol, and octanol; aromatic alcohols, such as benzyl alcohol, cinnamyl alcohol, 1-phenoxy-2-propanol, phenyldiglycol, α-methylbenzyl alcohol, dimethylbenzylcarbinol, benzyloxyethanol, phenoxyethanol, phenoxyisopropanol, p-anisyl alcohol, diethylene glycol monophenyl ether, phenethyl alcohol, and POE(2) benzyl alcohol ether; cyclic alcohols, such as cyclohexanol; N-alkylpyrrolidones, such as N-methylpyrrolidone, N-ethylpyrrolidone, and N-octylpyrrolidone; and alkylene carbonates, such as ethylene carbonate and propylene carbonate. The term "POE" refers to ethylene oxide, and the integer in parentheses indicates the number of moles of ethylene oxide added.

[0029] In the present invention, among the above penetrating agents, it is preferable to use an aromatic alcohol in order to enhance the penetration into the hair of the substance that reacts with the above metal salt to develop color. Among these, it is more preferable to use at least one selected from benzyl alcohol, benzyloxyethanol, phenethyl alcohol, and POE(2) benzyl ether in order to achieve a significantly superior penetration effect.

[0030] The content of the penetrating agent in the first agent of the non-oxidative hair dye of the present invention is not particularly limited as long as the desired effect is sufficiently exhibited. However, in order to enhance the penetration of the substance that reacts with the metal salt to develop color, the content is preferably 0.5% by mass or more, and more preferably 1% by mass or more, based on 100% by mass of the first agent. Furthermore, in order to maintain the stability of the formulation and ensure safety, the content is preferably 15% by mass or less, and more preferably 10% by mass or less, based on 100% by mass of the first agent. Note that the content of the penetrating agent is the amount converted to a pure content. It also refers to the total content of the penetrating agent blended in the first agent of the non-oxidative hair dye of the present invention.

[0031] In addition to the above-mentioned components, the first agent of the non-oxidative hair dye of the present invention may contain, as appropriate depending on the purpose, anionic surfactants, amphoteric surfactants, nonionic surfactants, polyhydric alcohols, higher alcohols, fatty acid ester oils, viscosity modifiers, film-forming agents, preservatives, fragrances, ethanol, etc., as long as the effects of the present invention are not impaired. The balance of the first agent of the non-oxidative hair dye of the present invention is purified water.

[0032] The pH of the first agent of the non-oxidative hair dye of the present invention is adjusted to an acidic range in order to moderate the color-developing reaction when mixed with the second agent described below, and to promote the excellent color-developing effect of the laccaic acid and to achieve an excellent dyeing effect in the hair. In the present invention, a pH adjuster may or may not be used as long as the pH of the first agent can be adjusted to an acidic range. When the pH adjuster is used, its content is not particularly limited as long as it is an amount that can adjust the pH to the desired level.

[0033] When a pH adjuster is used, examples thereof include sodium hydroxide, potassium hydroxide, hydrochloric acid, phosphoric acid, citric acid, lactic acid, arginine, glyoxylic acid, etc., and these may be used as buffer solutions. Of these components, sodium hydroxide, lactic acid, and glyoxylic acid are preferably used.

[0034] In the present invention, the preferred pH range, which allows the metal salt and the substance that reacts with the metal salt to develop color to react gently during mixing, promotes the excellent color-developing effect of laccaic acid, and enables excellent dyeing effects in the hair, is preferably a pH range of 1.8 to 5, and more preferably a pH range of 2 to 4. In the present invention, it is not preferable for the pH of the first agent to be outside the above pH range, particularly a pH < 1.6 range or a pH ≥ 6 range, because it makes it impossible to dye hair to the color expected from laccaic acid. Furthermore, the reaction proceeds too quickly during mixing, causing color development, resulting in poor dyeing effects in the hair, making it difficult to dye the hair to the desired color.

[0035] The formulation of the first agent of the non-oxidative hair dye of the present invention is not particularly limited as long as it sufficiently exhibits the desired effect, but examples include liquid, gel, emulsion, cream, etc.

[0036] The method for producing the first agent of the non-oxidative hair dye of the present invention is not particularly limited, but it can be produced by, for example, a known method. Specifically, for example, the above-mentioned components are mixed and stirred by a known method, such as a disper mixer, a homomixer, or a disper mill, but the present invention is not limited to these production methods.

[0037] Next, the second agent of the non-oxidative hair dye of the present invention will be described.

[0038] The second agent of the non-oxidative hair dye of the present invention contains a metal salt. In the present invention, the metal salt is a component that reacts with the metal salt contained in the first agent to cause a color-developing substance to develop color. The use of the metal salt allows for safe dyeing without damaging the hair.

[0039] Examples of the metal salts that can be used include iron salts, zinc salts, and copper salts. These metal salts may be used alone or in combination of two or more. In the present invention, from the viewpoint of achieving a good dyeing effect, it is preferable to use iron salts among the above metal salts.

[0040] Specific examples of the iron salt include ferrous sulfate, ferric sulfate, ferrous chloride, ferric chloride, ferrous acetate, ferric acetate, ferrous gluconate, ferrous nitrate, and ferrous lactate. These iron salts may be used alone or in combination of two or more. In the present invention, among the above iron salts, ferrous sulfate, ferric sulfate, ferrous chloride, and ferric chloride are more preferably used to achieve significantly superior dyeing effects, and ferrous sulfate, which is highly versatile, is most preferably used.

[0041] The metal salts may be commercially available. Examples of commercially available ferrous sulfate include Ferrous Sulfate (trade name, manufactured by Fuji Chemical Industry Co., Ltd.).

[0042] The content of metal salt in the second agent of the non-oxidative hair dye of the present invention is not particularly limited as long as the desired effect is sufficiently exhibited. However, to exhibit a good dyeing effect, it is preferably 0.5% by mass or more, more preferably 1% by mass or more, based on 100% by mass of the second agent. Furthermore, from the viewpoint of storage stability of the preparation, it is preferably 25% by mass or less, more preferably 20% by mass or less, based on 100% by mass of the second agent. The content of the metal salt is the amount converted to a pure content. It is also the total amount of the metal salt blended in the second agent of the non-oxidative hair dye of the present invention.

[0043] The second agent of the non-oxidative hair dye of the present invention contains an organic acid. In the present invention, the stability of the second agent itself can be improved by adjusting the pH to the acidic range using an organic acid. In addition, by mitigating color development due to the reaction with the metal salt during mixing, the excellent color development effect of the laccaic acid contained in the first agent can be exerted.

[0044] Specific examples of the organic acid include dicarboxylic acids such as oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, fumaric acid, and maleic acid; straight-chain fatty acids such as formic acid, acetic acid, propionic acid, butyric acid, and valeric acid; acidic amino acids such as glutamic acid and aspartic acid; and oxyacids such as glycolic acid, lactic acid, hydroxyacrylic acid, α-oxybutyric acid, glyceric acid, tartronic acid, malic acid, tartaric acid, and citric acid. These organic acids may be used alone or in appropriate combination of two or more.

[0045] In the present invention, among the above organic acids, it is preferable to use an oxyacid, which increases the formulation stability of the second agent itself, moderates the color development due to the reaction with the metal salt during mixing, and allows laccaic acid to exert its excellent dyeing effect. It is more preferable to use at least one selected from malic acid, tartaric acid, and citric acid, and it is most preferable to use citric acid and / or malic acid.

[0046] In the present invention, the preferred pH range of the second agent is from 1.8 to 5, and more preferably from 2 to 4. In the present invention, if the pH of the second agent is outside the above pH range, particularly in the region of pH 7 or higher, a reaction will proceed upon mixing, causing color development, resulting in poor dyeability within the hair, making it difficult to dye the hair to the desired color.

[0047] The content of organic acid in the second agent of the non-oxidative hair dye of the present invention is not particularly limited as long as it is an amount that can adjust the pH to the above-mentioned range and sufficiently exhibits the desired effect. However, in order to improve the formulation stability of the second agent itself, to moderate color development due to the reaction with the metal salt when the first agent and the second agent are mixed, and to exhibit excellent dyeing effects on hair, the content is preferably 0.05% by mass or more, more preferably 0.1% by mass or more, based on 100% by mass of the second agent. Furthermore, in order to improve safety during use and dyeability, the content is preferably 5% by mass or less, more preferably 4% by mass or less, based on 100% by mass of the second agent. Note that the content of the organic acid is the amount converted to a pure content. Furthermore, it is the total content of organic acid blended in the second agent of the non-oxidative hair dye of the present invention.

[0048] The second agent of the non-oxidative hair dye of the present invention contains carrageenan. The use of carrageenan not only improves the formulation stability of the second agent itself, but also contributes to mitigating the reaction between the metal salt and the substance that reacts with the metal salt to develop color after mixing the first and second agents. It also prevents the agent from dripping from the hair during application, contributing to achieving significantly better dyeing effects.

[0049] The carrageenan includes isomers such as mu, kappa, neu, iota, lambda, xi, and theta types. These carrageenans may be used alone or in combination of two or more types. In the present invention, it is preferable to use kappa or iota carrageenans in order to improve the formulation stability.

[0050] Commercially available carrageenans can be used. Commercially available kappa-type carrageenans include, for example, Carrageenan CSK-1 (trade name, manufactured by San-ei Gen SFI), Carrageenan CS-1 (trade name, manufactured by Ina Food Industry Co., Ltd.), Genugel WG, and Genugel WR (trade names, all manufactured by Copenhagen Pectin Factory). Commercially available iota-type carrageenans include, for example, Carrageenan CSI-1 (trade name, manufactured by San-ei Gen SFI), Lageenan CS-2 (trade name, manufactured by Ina Food Industry Co., Ltd.), Genuvisco JJ, Genugel CJ, and Genuvisco PJ-JPE (trade names, all manufactured by Copenhagen Pectin Factory).

[0051] The content of carrageenan in the second agent of the non-oxidative hair dye of the present invention is not particularly limited as long as the desired effect is sufficiently exhibited, but in order to improve the formulation stability of the second agent itself and to prevent dripping during application, it is preferably 0.3% by mass or more, more preferably 0.5% by mass or more, based on 100% by mass of the second agent. Furthermore, in order to improve mixability with the first agent, it is preferably 4% by mass or less, more preferably 3% by mass or less, based on 100% by mass of the second agent. Note that the content of carrageenan is the amount converted to a pure content. It also refers to the total content of carrageenan blended in the second agent of the non-oxidative hair dye of the present invention.

[0052] In addition, it is preferable to further blend a stabilizer such as ascorbic acid and / or its derivatives, or cysteine ​​and / or its derivatives in the second agent of the non-oxidative hair dye of the present invention in order to prevent oxidation during mixing and to control the degree of color development due to the reaction with the metal salt.

[0053] The content of the stabilizer in the second part of the non-oxidative hair dye of the present invention is not particularly limited as long as the desired effect is sufficiently exhibited. However, to prevent oxidation during mixing, the content is preferably 0.01% by mass or more, more preferably 0.05% by mass or more, based on 100% by mass of the second part. Furthermore, to prevent discoloration and precipitation of the stabilizer itself and to prevent a decrease in dyeability due to an excessively mild color-developing reaction, the content is preferably 3% by mass or less, more preferably 2% by mass or less, based on 100% by mass of the second part. The above stabilizer content is the amount converted to a pure content. It also refers to the total content of stabilizers blended in the second part of the non-oxidative hair dye of the present invention.

[0054] In addition to the above-mentioned components, the second agent of the hair treatment agent of the present invention may contain, as appropriate depending on the purpose, other ingredients such as anionic surfactants, cationic surfactants, amphoteric surfactants, nonionic surfactants, polyhydric alcohols, higher alcohols, fatty acid ester oils, film-forming agents, viscosity modifiers other than the above-mentioned carrageenans, preservatives, fragrances, etc., so long as the effects of the present invention are not impaired. Furthermore, purified water is used as the balance of the second agent of the non-oxidative hair dye of the present invention.

[0055] The dosage form of the second agent of the non-oxidative hair dye of the present invention is not particularly limited as long as it sufficiently exhibits the desired effect, but examples include liquid, gel, emulsion, and cream.

[0056] The method for producing the second agent of the non-oxidative hair dye of the present invention is not particularly limited, but it can be produced by, for example, a known method. Specifically, for example, the above-mentioned components are mixed and stirred by a known method, such as a disper mixer, a homomixer, or a disper mill, but the present invention is not limited to these production methods.

[0057] In the non-oxidative hair dye of the present invention described above, the mixing ratio of the first agent and the second agent is not particularly limited as long as the desired effect is sufficiently exhibited, but from the viewpoint of exhibiting a good dyeing effect, the mass ratio (first agent:second agent) is preferably 1:2 to 12:1, and more preferably 1:1 to 10:1.

[0058] The non-oxidative hair dye of the present invention is characterized by comprising at least the first agent and the second agent. That is, the non-oxidative hair dye of the present invention is a non-oxidative hair dye kit comprising at least the first agent and the second agent. The non-oxidative hair dye of the present invention may further comprise a third agent in addition to the first agent and the second agent. Examples of the third agent include hair shampoo, hair rinse, hair treatment agent, and hair conditioner.

[0059] The non-oxidative hair dye of the present invention contains at least the first and second agents, which allows mixing at the time of use, eliminating the labor required during application that was not possible with conventional non-oxidative hair dyes, and can be said to be a hair dye that exhibits excellent effects and is easier to use. Another feature of the non-oxidative hair dye of the present invention is that it can exhibit the same dyeing effect as conventional non-oxidative hair dyes even when mixed in advance.

[0060] Next, a method for treating hair using the non-oxidative hair dye of the present invention will be described.

[0061] The non-oxidative hair dye of the present invention is characterized by comprising at least the first agent and the second agent, which are mixed before use. In the present invention, from the viewpoint of suppressing color development during mixing and achieving excellent dyeing effects in the hair, it is desirable to mix the first agent and the second agent just before treatment and apply the mixture to the hair.

[0062] The method of application using the non-oxidative hair dye of the present invention is not particularly limited as long as it can fully achieve the desired effect, but an example is a method in which the non-oxidative hair dye is mixed with dry hair and applied to the hair in order to more effectively penetrate the hair. The time for which the non-oxidative hair dye is allowed to soak into the hair is not particularly limited, but it is preferable to leave it on for 10 to 40 minutes in order to enhance penetration of the substance that reacts with the metal salt to develop color into the hair and to achieve a good dyeing effect. After leaving it on, it is preferable to rinse it off with warm water.

[0063] The non-oxidative hair dye of the present invention has the advantage of requiring fewer treatment steps and shortening treatment time compared to conventional non-oxidative hair dye application methods, in which a first agent is applied to the hair and left for a certain period of time, followed by a second agent and then left for another certain period of time. In other words, the non-oxidative hair dye of the present invention exhibits an especially remarkable effect in terms of ease of application. [Example]

[0064] The present invention will be described in more detail below based on examples, but the present invention is not limited to these examples. Unless otherwise specified, the blending amounts are expressed in "% by mass," and all evaluations were carried out at a constant temperature (25±2°C).

[0065] (Sample preparation 1) The first agent of the non-oxidative hair dye of the present invention was prepared in a conventional manner according to the compositions shown in Tables 1 and 2, and was subjected to the following evaluations. Note that the blending amounts in the tables are all pure values ​​unless otherwise specified.

[0066] Test Example 1: Evaluation of formulation stability of first agent Each of the prepared first formulations was sealed in a 50 mL transparent glass container and stored at a constant temperature of 25±2°C for 4 weeks, after which the condition of the formulation was visually evaluated according to the following evaluation criteria. The evaluation was carried out by five expert evaluators, and the results were determined by combining the evaluations of each evaluator.

[0067] <Evaluation criteria for formulation stability of first drug> ○ (Good): Almost no sediment, precipitates, or discoloration is observed, and the product remains in the same condition as immediately after preparation. △ (Insufficient): Some sediment, precipitates, or discoloration is observed, but the condition is maintained × (bad): Obvious sediment or precipitates or significant discoloration are observed

[0068] [Table 1]

[0069] [Table 2]

[0070] (Sample preparation 2) The second part of the non-oxidative hair dye of the present invention was prepared in a conventional manner according to the compositions shown in Tables 3 to 6, and two-part non-oxidative hair dyes were prepared using the first part (1-1) or (1-2) shown in Table 1, and were subjected to the following evaluations. Note that the blending amounts in the tables are all pure values ​​unless otherwise specified.

[0071] (Sample preparation 3) According to the composition shown in Table 7, a second agent that does not satisfy the constitution of the non-oxidative hair dye of the present invention was prepared in a conventional manner and evaluated in the same manner.

[0072] Test Example 2: Evaluation of formulation stability of second agent Each of the prepared second agents (second agents of Examples 1 to 16 and second agents of Comparative Examples 1 to 4) was sealed in a 50 mL transparent glass container and stored in a constant temperature bath at 45°C for 4 weeks, after which the condition of the agent was visually evaluated according to the following evaluation criteria. The evaluation was carried out by five expert evaluators, and the results were determined by combining the evaluations of each evaluator.

[0073] <Evaluation criteria for formulation stability of second drug> ○ (Good): Almost no sediment, precipitates, or discoloration is observed, and the product remains in the same condition as immediately after preparation. △ (Insufficient): Some sediment, precipitates, or discoloration is observed, but the condition is maintained × (bad): Obvious sediment or precipitates or significant discoloration are observed

[0074] (Test Example 3: Evaluation of color change after mixing) The first and second parts of Examples 1 to 12 in Tables 3 and 4 and Examples 17 to 20 in Table 6 were mixed, and the color change (darkening) of the mixed composition was evaluated 1 minute, 5 minutes, 10 minutes, 20 minutes, and 30 minutes after mixing, and scored according to the following evaluation criteria. The scoring was carried out by five expert evaluators, and the score was determined from the score given by each evaluator.

[0075] <Score criteria> 1: Bright red 2: Slightly dark red 3: dark red 4:Dark brown 5: Dark brown to black

[0076] (Test Example 4: Evaluation of dyeability) The first and second agents of Examples 1 to 12 in Tables 3 and 4 and Examples 17 to 20 in Table 6 were mixed, and 0.8 g of the composition immediately after mixing was applied to 0.4 g of a human gray hair bundle (manufactured by Beaulux), which was then spread and allowed to blend in, and left at a constant temperature (25±2°C) for 30 minutes. The hair was then rinsed with lukewarm water and air-dried. Regarding the "dyeability" of the hair, the brightness of the dyed hair and that of a bundle of untreated human gray hair (manufactured by Beaulux) were measured using a color reader (manufactured by Konica Minolta), and the evaluation was based on the ΔL value and Δa value, which indicate the difference in brightness from the untreated gray hair.

[0077] Incidentally, the greater the difference in brightness, the higher the dyeing effect, and the higher the Δa value, the stronger the reddish color, making it unsuitable for dyeing gray hair. Therefore, in the present invention, a ΔL value greater than 20 (ΔL value > 20) and a Δa value less than 20 (Δa value < 20) was determined to have excellent dyeing power for gray hair dye.

[0078] [Table 3]

[0079] [Table 4]

[0080] [Table 5]

[0081] [Table 6]

[0082] [Table 7]

[0083] Since the non-oxidative hair dye of the present invention is mixed in advance before use, there is no need to leave each agent for a certain period of time after application as with conventional non-oxidative hair dyes, which shortens the treatment time and reduces the time required for the treatment itself, demonstrating significantly superior convenience.

[0084] Furthermore, it can be seen that the non-oxidative hair dye of the present invention, even when premixed, does not adversely affect the dyeing and exhibits excellent dyeing effects, because the metal salt contained in the second agent reacts gently with the substance that reacts with the metal salt contained in the first agent to develop color. In contrast, it can be seen that the formulation stability of the second agent is significantly inferior in the comparative examples that do not satisfy the constitution of the non-oxidative hair dye of the present invention. It is clear that a second agent with such poor formulation stability cannot cause a gentle reaction even when mixed, and therefore adversely affects the dyeing and fails to exhibit excellent dyeing effects.

Claims

1. A non-oxidative hair dye comprising at least an acidic first agent containing at least laccaic acid among substances that react with metal salts to develop color, and an acidic second agent containing metal salts, which are mixed together before use, the second agent contains an organic acid and carrageenan, A non-oxidative hair dye characterized in that citric acid and / or malic acid is used as the organic acid.

2. 2. The non-oxidative hair dye according to claim 1, wherein the content of laccaic acid in the first agent is 0.5 to 4% by mass.

3. 3. The non-oxidative hair dye according to claim 1, wherein the pH of the first agent is in the range of 1.8 to 5, and the pH of the second agent is in the range of 1.8 to 5.

4. 4. The non-oxidative hair dye according to claim 1, which is used to hide gray hair.

Images