Composition for dyeing hair

Abstract

The present invention relates to a composition for dyeing hair. The composition for dyeing hair of the present invention can be used as a single formulation or applied as a two-formulation system comprising a dyeing part and a base part, and comprises tannic acid, gallic acid, and a ferrous salt in an optimal ratio, thereby realizing excellent dyeability compared to conventional chemical hair dyes. In addition, the particle size distribution of a mixture in the dyeing part of the composition for dyeing hair of the present invention enables uniform dispersion on the surface of hair and provides effective penetration into the hair in an aqueous environment, and the composition provides a stable dyeing effect under various conditions including high-temperature storage.

Description

Hair dyeing composition

[0001] This patent application claims priority to Korean Patent Application No. 10-2024-0174749 filed with the Korean Intellectual Property Office on November 29, 2024, the disclosures of said patent application are incorporated herein by reference.

[0002] The present invention relates to a composition for dyeing hair.

[0003] Hair dyes used for dyeing hair can generally be classified into oxidative hair dyes, which are permanent hair dyes; non-oxidative hair dyes, which are semi-permanent hair dyes; and temporary hair dyes.

[0004] Oxidative hair dyes are the most widely used hair dyes because they achieve excellent dyeing power through an oxidation reaction between an alkaline agent and an oxidizing agent, which is an oxidizing dye. During this oxidation reaction, a colorant penetrates the interior of the hair, making the dye difficult to remove. Oxidative hair dyes contain compositions such as alkaline agents and oxidizing agents along with pigment precursors for dyeing; however, the harmful effects of such compositions on the human body have been revealed, raising concerns.

[0005] In particular, ammonia, used as an alkaline agent, is an irritating substance that irritates the scalp, eyes, and skin, causing allergic reactions; monoethanolamine causes scalp irritation and damages the hair itself by destroying disulfide bonds; and para-phenylenediamine (p-phenylenediamine, PPD) is partially oxidized to cause contact allergies such as rashes, itching, and swelling on the scalp, and in severe cases, side effects such as permanent vision loss and hair loss exist.

[0006] Non-oxidizing hair dyes do not use oxidizing agents but have problems with low dyeing power and short duration, while temporary hair dyes produce a dyeing effect by temporarily coloring the cuticle (the surface of the hair) with pigment, but the effect disappears with shampooing, resulting in a very short duration.

[0007] Recently, shampoo products utilizing the principle of polyphenol enzymes that cause apples to brown using 1,2,4-trihydroxybenzene (1,2,4-THD) have been marketed, but 1,2,4-THD is controversial as it is a metabolite of benzene, a carcinogen, and has the potential to cause genotoxicity.

[0008] Accordingly, there is a need to develop a stable hair dye that replaces the aforementioned artificial oxidative dyes while possessing excellent dyeing power and durability, and being free from skin irritation.

[0009] [Prior Art Literature]

[0010] [Non-patent literature]

[0011] (Non-patent Document 0001) Sang Yeong Han, Eunhye K. Kang, Insung S. Choi (2021). Iron Gall Ink Revisited: A Surfactant-Free Emulsion. Technology for Black Hair-Dyeing Formulation. Cosmetics 8, no.1.

[0012] The objective of the present invention is to provide a hair dyeing composition that minimizes scalp irritation by replacing artificial pigments with naturally derived ingredients, enables uniform dispersion on the hair surface and internal penetration through optimized ingredient ratios and particle size distribution, and provides a stable dyeing effect even under various conditions including high-temperature storage.

[0013] According to one aspect of the present invention, the present invention comprises a dyeing part comprising polydihydroxyindole; and a mixture containing tannic acid, gallic acid, and a divalent iron salt, and

[0014] The present invention aims to provide a hair dyeing composition in which tannic acid, gallic acid, and divalent iron salt are mixed in a weight ratio of 1:1:1 to 1:5:1 in the above mixture.

[0015] According to another aspect of the present invention, the present invention aims to provide a hair dyeing kit comprising a dyeing part comprising polydihydroxyindole; and a mixture containing tannic acid, gallic acid, and a divalent iron salt, wherein the tannic acid, gallic acid, and the divalent iron salt in the mixture are mixed in a weight ratio of 1:1:1 to 1:5:1.

[0016] According to another aspect of the present invention, the present invention aims to provide a cosmetic product for hair dyeing comprising the hair dyeing composition of the present invention.

[0017] The hair dyeing composition of the present invention can be used as a single formulation or applied as a two-formulation system including a dyeing part and a base part, and is composed of tannic acid, gallic acid, and divalent iron salt in an optimal ratio to achieve superior dyeing power compared to conventional chemical hair dyes.

[0018] Figure 1 is a figure showing the dyeing results according to the mixing ratio of gallic acid, tannic acid, and divalent iron salt according to one embodiment of the present invention.

[0019] FIG. 2 is a figure showing the appearance immediately after mixing the dyeing part and the base part according to the mixing ratio of the dyeing part and the base part of a two-part system according to one embodiment of the present invention.

[0020] Figure 3 is a figure showing the results of a comparative evaluation of dyeing efficacy according to the mixing ratio of the dyeing part and the base part of a two-part system according to one embodiment of the present invention.

[0021] FIGS. 4a to 4c are figures showing the results of measuring the particle size of a mixture of gallic acid, tannic acid, and divalent iron salt of a two-dose system according to one embodiment of the present invention three times.

[0022] The present invention relates to a hair dyeing composition comprising a dyeing part comprising polydihydroxyindole; and a mixture containing tannic acid, gallic acid, and a divalent iron salt, wherein the tannic acid, gallic acid, and the divalent iron salt in the mixture are mixed in a weight ratio of 1:1:1 to 1:5:1.

[0023] Hereinafter, the present invention will be described in detail with reference to embodiments and drawings of the present invention.

[0024] The present invention comprises a dyeing part comprising polydihydroxyindole; and a mixture containing tannic acid, gallic acid, and a divalent iron salt, and

[0025] The present invention relates to a hair dyeing composition in which tannic acid, gallic acid, and divalent iron salt are mixed in a weight ratio of 1:1:1 to 1:5:1 in the above mixture.

[0026] The hair dyeing composition of the present invention comprises a dyeing part, wherein the dyeing part comprises polydihydroxyindole; and a mixture containing tannic acid, gallic acid, and a divalent iron salt. The 'dyeing part' may refer to a composition comprising components for dyeing hair.

[0027] According to one embodiment of the present invention, the tannic acid, the gallic acid, and the divalent iron salt in the mixture may be included in a weight ratio of 1:1:1 to 1:5:1, for example, 1:2:1, but are not limited thereto. In the above weight ratio, the tannic acid, gallic acid, and divalent iron salt combine to maintain hair dyeing power. If the weight ratio of the gallic acid is 1 or less compared to the tannic acid, the mixture of tannic acid, gallic acid, and divalent iron salt may not be sufficiently attached to the polydihydroxyindole, resulting in a decrease in hair dyeing power. If the weight ratio of the gallic acid exceeds 5 times compared to the tannic acid, a problem may occur in which the dyeing efficiency decreases relative to the gallic acid content. According to Experimental Example 1 of the present invention, when tannic acid, gallic acid, and divalent iron salt were mixed in a weight ratio of 1:2:1, the lowest L value was observed, demonstrating excellent dyeing power. These results suggest that the components in the mixture form effective bonds at the corresponding weight ratio and attach to polydihydroxyindole to exhibit an optimal dyeing effect.

[0028] The above 'Polydihydroxyindole' is a polymer of 5,6-dihydroxyindole, a polymer of a compound having a structure as shown in the following chemical formula. 5,6-dihydroxyindole is a precursor of blackish-brown melanin, is harmless to the human body, can provide a clearer black color than existing natural pigments, and has high oxidative reactivity, so it is used as a hair dye in combination with antioxidants.

[0029] [Chemical Formula 1]

[0030]

[0031] The above polydihydroxyindole is present in an amount of 0.001 to 10 wt%, 0.001 to 5 wt%, 0.001 to 1 wt%, 0.001 to 0.5 wt%, 0.001 to 0.2 wt%, 0.005 to 10 wt%, 0.005 to 5 wt%, 0.005 to 1 wt%, 0.005 to 0.5 wt%, 0.005 to 0.2 wt%, 0.005 to 0.15 wt%, 0.01 to 10 wt%, 0.01 to 5 wt%, 0.01 to 1 wt%, 0.01 to 0.5 wt%, 0.01 to 0.2 wt%, 0.01 to 0.15 wt%, 0.05 to 10 wt% based on the total weight of the composition. It may contain 0.05 to 5 weight%, 0.05 to 1 weight%, 0.05 to 0.5 weight%, 0.05 to 0.2 weight%, 0.05 to 0.15 weight%, 0.1 to 10 weight%, 0.1 to 5 weight%, 0.1 to 1 weight%, 0.1 to 0.5 weight%, 0.1 to 0.2 weight%, for example, 0.13 weight%, but is not limited thereto.

[0032] The above 'mixture containing tannic acid, gallic acid, and divalent iron salt' refers to a composition in which two or more of the components contained in the mixture can form a complex with each other. The complex can act as a coating agent and can also interact with polydihydroxyindole within the composition. In one embodiment, the mixture may be a mixture of tannic acid, gallic acid, and divalent iron salt. Specifically, the tannic acid, gallic acid, and divalent iron salt can interact with each other and attach to form a complex, and the complex thus formed can also attach to polydihydroxyindole.

[0033] The above 'tannic acid' refers to a type of polyphenol compound that has a structure in which multiple galloyl groups are connected to a glucose molecule by ester bonds.

[0034] The above gallic acid may be gallic acid or a derivative of gallic acid.

[0035] The above 'gallic acid' refers to 3,4,5-trihydroxybenzoic acid, which is a phenolic compound having three hydroxyl groups (-OH) and one carboxyl group (-COOH) on a benzene ring. The above 'derivative of gallic acid' may be an alkyl ester in which, based on the structure of gallic acid, the three hydroxyl groups contained in gallic acid are each independently substituted with an alkyl, alkoxy, polyoxyethylene group, polyoxypropylene group, monosaccharide, disaccharide, or oligosaccharide, and the alkyl group is substituted with the carboxyl group of gallic acid. For example, the alkyl ester of gallic acid may be a straight-chain or branched alkyl ester having 1 to 10 carbon atoms, preferably 2 to 5 carbon atoms, but is not limited thereto.

[0036] The above 'derivative of gallic acid' may be diglucosyl gallic acid, propyl gallate, dodecyl gallate, butyl gallate, ethyl gallate, and mixtures thereof, but is not limited thereto.

[0037] The above 'divalent iron salt' refers to a compound formed by combining an iron (Fe) atom with an anion, having an oxidation state of +2.

[0038] The above divalent iron salt may be one or more selected from the group consisting of ferrous acetate, ferrous lactate, ferrous propionate, ferrous fumarate, ferrous citrate, and ferrous gluconic acid, for example, ferrous gluconic acid, but is not limited thereto.

[0039] According to one embodiment of the present invention, the mixture of tannic acid, gallic acid, and divalent iron salt may be included in an amount of 0.01 to 10 wt%, 0.01 to 8 wt%, 0.01 to 4 wt%, 0.01 to 2 wt%, 0.1 to 10 wt%, 0.1 to 8 wt%, 0.1 to 4 wt%, 0.1 to 2 wt%, 0.5 to 10 wt%, 0.5 to 8 wt%, 0.5 to 4 wt%, 0.5 to 2 wt%, for example, 1 wt% based on the total weight of the composition, but is not limited thereto.

[0040] The particle size of the above mixture may be 10 to 50 μm, 10 to 45 μm, 10 to 40 μm, 10 to 35 μm, 10 to 30 μm, 15 to 50 μm, 15 to 45 μm, 15 to 40 μm, 15 to 35 μm, 15 to 30 μm, 20 to 50 μm, 20 to 45 μm, 20 to 40 μm, 20 to 35 μm, for example, 20 to 30 μm.

[0041] Dyeing power and color stability are maintained within the above particle size range, and if the particle size of the mixture is below or exceeds the above range, the dyeing power or durability may be reduced. On the other hand, if the particle size of the mixture exceeds the above range, it may result in stained dyeing.

[0042] The above dyeing part may further include polyol and pomegranate extract.

[0043] The above 'polyol' refers to a polyhydric alcohol compound containing two or more hydroxyl groups (-OH) within a molecule. In the dyeing composition of the present invention, the polyol can play a role in improving the moisturizing properties of the hair and facilitating the penetration of polydihydroxyindole and the mixture into the hair. According to Experimental Example 2 of the present invention, the dyeing composition containing the polyol exhibited excellent dyeing power and color stability for hair.

[0044] The above polyol may be one or more selected from the group consisting of glycerin, propanediol (1,3-propanediol), 1,2-hexanediol, propylene glycol (1,2-propanediol), and butylene glycol (1,3-butylene glycol), and for example, it may be glycerin, but is not limited thereto.

[0045] The above polyol may comprise 1 to 30 wt%, 1 to 28 wt%, 1 to 26 wt%, 12 to 30 wt%, 12 to 28 wt%, 12 to 26 wt%, 18 to 30 wt%, 18 to 28 wt%, 18 to 26 wt%, 22 to 30 wt%, 22 to 28 wt%, for example, 22 to 26 wt% based on the total weight of the composition, but is not limited thereto.

[0046] The above 'pomegranate extract' refers to a component extracted from the peel, pulp, seeds, or a mixture thereof of the pomegranate tree (Punica granatum L.). The pomegranate extract contains bioactive substances such as polyphenol compounds, ellagic acid, punicalagin, and anthocyanin, and can serve as a natural pigment auxiliary in the dyeing composition of the present invention. The polyphenol compounds contained in the pomegranate extract form bonds with divalent iron salts and tannic acid to improve the stability of the dye, while the anthocyanin component enhances the color development of the complex to impart a natural color. Furthermore, the antioxidant components of the pomegranate extract can prevent oxidative damage to the hair that may occur during the dyeing process, protect the hair cuticle layer, and reduce protein damage, thereby contributing to maintaining the health of the hair after dyeing.

[0047] The above pomegranate extract may be included in an amount of 0.0001 to 0.01 wt%, 0.0001 to 0.005 wt%, 0.0005 to 0.01 wt%, 0.0005 to 0.005 wt%, 0.0008 to 0.01 wt%, 0.0008 to 0.005 wt%, for example, 0.0009 to 0.002 wt% based on the total weight of the composition, and preferably 0.001 wt%, but is not limited thereto.

[0048] The above dyeing part may not contain water. If the above dyeing part does not contain water, it may help improve the stability of the dyeing composition and the duration of the dyeing effect.

[0049] The dyeing composition may further include a base part in addition to the dyeing part. When both the dyeing part and the base part are included in the hair dyeing composition of the present invention, the dyeing part is used as the first agent in the hair dyeing composition of the present invention, and can be mixed with the base part (second agent) immediately before use and applied to the hair. This two-component system ensures the stability of each component and can achieve an optimal dyeing effect at the time of use.

[0050] The above 'two-part system' may refer to a system in which a hair dyeing composition is composed of a dyeing part, which is a first part, and a base part, which is a second part, each independent, and is mixed immediately before use and applied to the hair.

[0051] The above base part may include water, a stabilizer, a conditioning agent, and ethanol.

[0052] The above 'base part' can improve color stability and durability in hair dyed through the dyeing part, and in this case, water included in the base part may affect color stability and dye durability.

[0053] The above 'water' can act as a medium to enhance the dyeing effect by providing a moist environment at the time of mixing with the dyeing part. When the hair dyeing composition of the present invention is applied as a two-formulation system, the base part may contain water and the dyeing part may not contain water, thereby improving the stability of each formulation of the dyeing part and the base part. In addition, the water in the base part provides appropriate viscosity and solubility when mixed with the dyeing part at the time of use, making it easy to apply the composition to the hair during hair dyeing.

[0054] The water in the base part of the present invention may be 50 to 70 wt%, 50 to 68 wt%, 50 to 65 wt%, 52 to 70 wt%, 52 to 68 wt%, 52 to 65 wt%, 55 to 70 wt%, 55 to 68 wt%, 55 to 65 wt%, 58 to 70 wt%, 58 to 68 wt%, 58 to 65 wt%, 60 to 70 wt%, 60 to 68 wt%, 60 to 65 wt%, for example, 61 to 63 wt% based on the total weight of the composition. In one embodiment, the water in the base part of the present invention may be 62.77 wt% based on the total weight of the composition.

[0055] The above 'stabilizer' may refer to a compound capable of improving the storage stability of the composition and maintaining the chemical stability of each component. In the hair dyeing composition of the present invention, the stabilizer may be included in one or more of the dyeing part or the base part, which may affect the overall stability and usability of the composition. Additionally, the stabilizer may function to maintain the uniform dispersion of the components within the dyeing composition and reduce phase separation between the components. For example, if the stabilizer is included in the dyeing part, which is the first component, it may help maintain the dispersion state of a mixture of tannic acid, gallic acid, and divalent iron salt; and if the stabilizer is included in the base part, which is the second component, it may contribute to maintaining a stable mixture state between water and other components within the base part, thereby improving storage stability.

[0056] The above stabilizer may be one or more selected from the group consisting of carbomer, xanthan gum, bentonite, silica silylate, cellulose, hydroxyethylcellulose, sodium polyacryloyl dimethyl taurate, ammonium acryloyl dimethyl taurate / VP copolymer, hydroxyethyl acrylate / sodium acryloyl dimethyl taurate copolymer, sodium acrylate / sodium acryloyl dimethyl taurate copolymer, sodium acryloyl dimethyl taurate / acrylamide / VP copolymer, hydroxypropylmethylcellulose stearoxyether, acrylate / C10-30 alkyl acrylate crosspolymer, polyacrylate crosspolymer-4, polyacrylate crosspolymer-6, and polyacrylate crosspolymer-11, for example, It may be polyacrylate crosspolymer-6, but is not limited thereto.

[0057] The above stabilizer may be included in an amount of 0.01 to 1 wt%, 0.01 to 0.5 wt%, 0.01 to 0.1 wt%, 0.01 to 0.05 wt%, 0.02 to 1 wt%, 0.02 to 0.5 wt%, 0.02 to 0.1 wt%, 0.02 to 0.05 wt%, for example, 0.03 wt% based on the total weight of the composition, but is not limited thereto.

[0058] The above 'conditioning agent' may refer to an ingredient that can affect the reduction of hair damage, shine, softness, and prevention of static electricity. In the dyeing composition of the present invention, the conditioning agent acts on the hair cuticle layer during the dyeing process to reduce physical and chemical effects, thereby reducing hair damage that may occur during the dyeing process. Additionally, by forming a film on the hair surface, it can affect the reduction of pigment loss after dyeing and the durability of the dye. Furthermore, the conditioning agent can reduce static electricity on the hair surface, contributing to improved combability and the formation of a soft texture.

[0059] The above conditioning agent may be one or more selected from the group consisting of behenyl alcohol, caprylyl glycol, cetearimonium chloride, dicaprylyl carbonate, panthenyl ethyl ether, pentylene glycol, stearyl alcohol, amodimethicone, dimethiconol, and cetearyl alcohol, for example, it may be caprylyl glycol, but is not limited thereto.

[0060] The above conditioning agent may be included in an amount of 0.01 to 1 wt%, 0.01 to 0.8 wt%, 0.01 to 0.6 wt%, 0.01 to 0.4 wt%, 0.05 to 1 wt%, 0.05 to 0.8 wt%, 0.05 to 0.6 wt%, 0.1 to 1 wt%, 0.1 to 0.8 wt%, 0.1 to 0.6 wt%, 0.1 to 0.4 wt%, for example, 0.2 wt% based on the total weight of the composition, but is not limited thereto.

[0061] The above 'ethanol' can act as a solvent together with water in the base part. Specifically, in the dyeing composition of the present invention, the ethanol can affect the dissolution of components included in the base part, and when the dyeing composition of the present invention is applied as a two-part system containing both a dyeing part and a base part, it can contribute to the dispersion of a mixture containing tannic acid, gallic acid, and divalent iron salt.

[0062] The above ethanol may be 5 to 30 wt%, 5 to 28 wt%, 5 to 24 wt%, 5 to 20 wt%, 5 to 18 wt%, 5 to 15 wt%, 10 to 30 wt%, 10 to 28 wt%, 10 to 24 wt%, 10 to 20 wt%, 10 to 18 wt%, 10 to 15 wt%, for example, 12 wt%, based on the total weight of the composition.

[0063] The above dyeing part:base part may have a weight ratio of 1:3 to 1:20. Specifically, the weight ratio may be 1:3 to 1:18, 1:3 to 1:15, 1:3 to 1:12, 1:5 to 1:20, 1:5 to 1:18, 1:5 to 1:15, 1:5 to 1:12, 1:8 to 1:20, 1:8 to 1:18, 1:8 to 1:15, or 1:8 to 1:12. In one embodiment, the dyeing part:base part may have a weight ratio of 1:10 to 1:20. Compared to the case where the dyeing part:base part is 1:3, the stability of the formulation may be improved at a weight ratio of 1:10 to 1:20, and transfer or residue may be reduced when applied to hair.

[0064] The hair dyeing composition of the present invention may have a formulation selected from one or more of the group consisting of a cream type, a liquid type, a powder type, a jelly type, and an aerosol type. Specifically, the hair dyeing composition formulation of the present invention may be a liquid type, but is not limited thereto.

[0065] In addition to the above components of the base part, the above composition may appropriately include components used in conventional dyeing compositions, such as preservatives, pH adjusters, antioxidants, chelating agents, surfactants, fragrances, and conditioning agents, in the base part to a extent that does not impair the effects of the present invention.

[0066] The above preservative may be one or more selected from the group consisting of 1,2-hexanediol, ethylhexylglycerin, benzyl glycol, chlorphenesin, phenoxyethanol, pentylene glycol, and caprylyl glycol, for example, it may be caprylyl glycol.

[0067] The above pH adjuster may be one or more selected from the group consisting of sodium hydroxide, potassium hydroxide, tromethamine, triethanolamine, arginine, aminomethylpropanol, isopropanolamine, and amino acids.

[0068] The above antioxidant may be one or more selected from the group consisting of ascorbic acid, erythorbic acid, cysteine ​​hydrochloride, sodium sulfite, and thioglycolic acid.

[0069] The above chelating agent may be one or more selected from the group consisting of EDTA, disodium EDTA, trisodium EDTA, tetrasodium EDTA, etidronic acid, and salts thereof.

[0070] The above surfactant may be one or more selected from the group consisting of cationic surfactants, anionic surfactants, and nonionic surfactants.

[0071] In addition, the present invention relates to a hair dyeing kit comprising a dyeing part comprising polydihydroxyindole; and a mixture containing tannic acid, gallic acid, and a divalent iron salt, wherein the tannic acid, gallic acid, and the divalent iron salt in the mixture are mixed in a weight ratio of 1:1:1 to 1:5:1.

[0072] The above kit may further include a base part in addition to the dyeing part, and may contain the same components and content as the aforementioned hair dyeing composition within each part.

[0073] In the case where the hair dyeing kit of the present invention includes both a dyeing part and a base part, just like the hair dyeing composition of the present invention, the dyeing part is used as the first agent in the hair dyeing composition of the present invention, and this can be applied as a two-drug system that is mixed with the base part, which is the second agent, immediately before use and applied to the hair. Therefore, when the hair dyeing composition of the present invention is applied as a two-drug system, it can also be provided in the form of a hair dyeing kit.

[0074] The above kit may have one or more formulations selected from the group consisting of cream type, liquid type, powder type, jelly type, and aerosol type. Specifically, the hair dyeing composition formulation of the present invention may be formulated as a liquid type, but is not limited thereto.

[0075] For the respective components, content, and resulting effects of the dyeing part and base part included in the above kit, refer to the corresponding description of the hair dyeing composition described above.

[0076] Furthermore, the present invention relates to a hair dyeing cosmetic comprising the hair dyeing composition of the present invention. The respective components, contents, and resulting effects of the dyeing part and base part included in the cosmetic can be described by referring to the corresponding descriptions of the aforementioned hair dyeing composition and kit.

[0077] The present invention will be explained in more detail below through the following examples and experimental examples. However, these examples and experimental examples are intended only to aid in understanding the present invention and do not limit the scope of the present invention in any way.

[0078]

[0079] Experimental Example 1. Evaluation of dyeing power according to the mixing ratio of tannic acid, gallic acid, and divalent iron salt

[0080] To prepare the hair dyeing composition of the present invention, the dyeing power according to the mixing ratio of each component of the mixture of tannic acid, gallic acid, and divalent iron salt in the dyeing part was first confirmed. To derive the mixing ratio, the mixtures of Example 1 and Comparative Examples (1-5) were first prepared with the compositions shown in Table 1 below, and an experiment was conducted using a composition of 1:2:1, which is the mixing ratio of tannic acid, gallic acid, and divalent iron salt, as Example 1. Ferrous gluconate was used as the divalent iron salt.

[0081] The above mixture was prepared as follows. First, purified water was heated to 75°C, and then tannic acid was added to the heated purified water and completely dissolved. Next, gallic acid was added and mixed uniformly, and finally, ferrous gluconate, a divalent iron salt, was slowly added while stirring. The mixture was continuously stirred at 75°C for 30 minutes to obtain a uniform solution. Subsequently, the solution was slowly cooled to lower the temperature to 30°C to prepare the final mixture.

[0082] Weight % (Weight Ratio) Example 1 Comparative Example 1 Comparative Example 2 Comparative Example 2 Comparative Example 4 Comparative Example 5 Tannic Acid 0.3 0.0 9 0.1 1 0.1 1 0.0 4 0.0 5 Gallic Acid 0.6 0.6 3 0.5 6 0.2 8 0.6 0.6 Ferrous Gluconate 0.3 0.2 8 0.3 3 0.6 0.3 5 0.0 5 Water To 100 To 100 To 100 To 100 To 100 To 100

[0083] Using Example 1 and Comparative Example (1-5) prepared according to the above manufacturing method, the dyeing power according to the mixing ratio of tannic acid, gallic acid, and divalent iron salt was evaluated as follows.

[0084] Each composition of Example 1 and Comparative Examples (1-5) was applied to a bleached hair sample (length 20 cm) in an amount of 1.5 to 2 times the weight of the hair. The applied hair was left at room temperature (25℃) for 10 minutes, and then dried using a hair dryer for 10 minutes.

[0085] Dry hair samples were placed in a photo box and photographed using a digital camera under constant illumination. The captured images were analyzed using the image analysis program ImageJ (National Institutes of Health, USA), and the L (lightness), R (redness), G (greenness), and B (blueness) values ​​of each sample were measured. Measurements were repeated three times for each sample, and the average value was calculated.

[0086] Example 1 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 Brightness (L*) 102115117111124119

[0087] (L*: Colorimeter lightness value, where a lower value indicates darker lightness)

[0088] According to the experimental results in Table 2, Example 1, in which tannic acid, gallic acid, and divalent iron salt were mixed in a weight ratio of 1:2:1, showed the lowest L value compared to Comparative Examples 1 to 5, which applied different mixing ratios. Here, the L value is an objective indicator of hair lightness, and a lower L value means that the hair has been dyed darker.

[0089] Specifically, Example 1 showed a statistically significant decrease in L value compared to Comparative Examples 1 to 5. Example 1 had significantly superior dyeing power compared to Comparative Examples 1 to 5.

[0090] Experimental Example 2. Evaluation of dyeing power and color stability of dyed parts according to solvent

[0091] To select the optimal solvent for the dyeing part, the dyeing effect and color stability of each solvent were evaluated as follows.

[0092] Propylene glycol (PG), butylene glycol (BG), ethanol, and glycerin were used as evaluation solvents. Samples were prepared using each solvent, and for the experiment, samples containing each solvent were applied to bleached hair at a ratio of 1.5 to 2 times the hair weight, and evaluations were conducted at the following measurement points:

[0093] 1) Immediate Dyeing Power: Evaluates the dyed state of the hair immediately after application.

[0094] 2) Color stability: Evaluate color retention after one week at 50℃ following application.

[0095] At each time point, images were taken in a photo box in the same manner as in Experimental Example 1 above, and L, R, G, and B values ​​were measured using the ImageJ program. The average value was calculated by repeating the measurement three times for each sample.

[0096] Solvent Lightness (L*) Before Hair Application PGBG Ethanol Glycerin Immediately After Application 178 125 128 124 118 1 Week After - 139 143 146 117

[0097] (L*: Colorimeter lightness value, where a lower value indicates darker lightness)

[0098] According to the results in Table 3, the dyeing effect was confirmed relative to the L value (178) before hair application under all solvent conditions used in the experiment. In the case of propylene glycol (PG), the L value was 125 immediately after application, showing good initial dyeing power, but it was observed that the color stability was somewhat low as it increased to 139 after one week. For butylene glycol (BG), the L value increased from 128 immediately after application to 143 after one week, and for ethanol, the L value increased from 124 immediately after application to 146 after one week.

[0099] Meanwhile, when glycerin was used as a solvent, the L value immediately after application was 118, indicating the best initial dyeing power, and the L value was maintained at 117 even after one week, indicating excellent color stability. Thus, it was experimentally confirmed that when glycerin is included as a solvent for the dyeing part of the present invention, it possesses excellent characteristics in terms of initial dyeing power and color stability.

[0100] Experimental Example 3. Evaluation of color stability according to water content

[0101] Apart from dyeing power, to evaluate color stability according to water content, various hair dyeing compositions of different formulations were prepared containing dyeing part compositions with similar content based on the total weight of the composition, including the water content shown in Table 4 below. Table 4 below shows only the content of water, glycerin, and ethanol.

[0102] Content (Weight%) Example 2 Comparative Example 6 Comparative Example 7 Comparative Example 8 Comparative Example 9 Comparative Example 10 Water 62.77 1510 50 70 Glycerin 23.86 95 590 60 52 Ethanol 122 011 11

[0103] In order to confirm whether the hair dyeing composition achieves color stability even at high temperatures, specifically, the composition was stored for one week at 50°C, and then hair was dyed and dried as in Experimental Example 2, and an image was obtained by taking a picture. The captured image was then analyzed using ImageJ (National Institutes of Health, USA) to derive L, R, G, and B values, and the results are shown in Table 5 below.

[0104] Lightness (L*) Example 2 Comparative Example 6 Comparative Example 7 Comparative Example 8 Comparative Example 9 Comparative Example 10 Immediately after dyeing 10 8 17 9 18 6 17 6 ​​12 49 61 One week later 9 8 17 7 19 2 17 5 12 7 170

[0105] (L*: Colorimeter lightness value, where a lower value indicates darker lightness)

[0106] According to the results in Table 5, differences in dyeing effects were observed under various water content conditions used in the experiment. Specifically, Example 2 showed an L value of 108 immediately after dyeing, which was lower than Comparative Examples 6 to 10. In addition, when measured after storage for one week under high temperature (50℃) conditions, the L value of Example 2 was 98, maintaining the lowest value compared to Comparative Examples 6 to 10.

[0107] The experimental results of Experimental Example 3 above experimentally demonstrated that both initial dyeing power and color stability are excellent under the water content conditions presented in the present invention, and a person skilled in the art can set an appropriate water content when preparing a hair dyeing composition based on the results of Experimental Example 3.

[0108] Experimental Example 4. Preparation of a hair dyeing composition

[0109] A hair dyeing composition was prepared based on the results of Experimental Examples 1 to 3. Specifically, in Experimental Example 1, dyeing power was evaluated by varying the mixing ratios of tannic acid, gallic acid, and divalent iron salt; as a result, the lowest L value was observed at a weight ratio of 1:2:1, confirming excellent dyeing power. According to the results of Experimental Example 2, when glycerin was used as the solvent for the dyeing part, both the initial dyeing power immediately after application (L value: 118) and the color stability after one week (L value: 117) were excellent. In Experimental Example 3, when the water content of the base part was set to 62.77%, it was confirmed that a stable L value was maintained immediately after dyeing and even after one week of storage at a high temperature (50℃).

[0110] Based on the above experimental results, a hair dyeing composition was prepared using a two-part system consisting of a dyeing part (Part 1) and a base part (Part 2) as shown in Table 6 below. All raw materials used in this experiment were purchased from raw material suppliers, and in particular, tannic acid, gallic acid, ferrous gluconate, and pomegranate extract were all purchased from Hyundai Bioland.

[0111] Specifically, the manufacturing method is as follows:

[0112] For the dyeing part (Part 1), all components of the dyeing part (including pomegranate extract prepared by the method below) were placed in a mixing container and wetted, then homogenized using a high-speed homogenizer (HOMO) at a temperature of 75°C or higher for 30 minutes at a speed of 5,000 rpm, and then the mixture was cooled to room temperature (20-25°C). For the base part (Part 2), the stabilizer was first homogenized in water at room temperature using a homogenizer at a speed of 5,000 rpm for 30 minutes, then separately dissolved ethanol and preservatives were added to the stabilizer dispersion and homogenized using a homogenizer at a speed of 5,000 rpm.

[0113] The pomegranate extract used in the dyeing part above is prepared by adding 150g of raw material powder, prepared by crushing a whole pomegranate tree plant containing 90% by weight or more of pomegranate tree flowers, to a 70% aqueous ethanol solution and extracting at 60°C for 5 hours. Subsequently, the extract is filtered once using a 250 mesh filter and then filtered a second time using a 5㎛ filter. The filtered extract is concentrated to 20% by weight relative to the initially added raw material powder, and then 1,3-butylene glycol is added to dilute it so that the ellagic acid content in the final extract is 400 ppm or more, thereby preparing the final pomegranate extract, which is then used in the dyeing part.

[0114] Classification | Composition | Weight % Dyeing Part | Polydihydroxyindole 0.13 | Mixture | Tannic Acid 0.25 | Gallic Acid 0.5 | Ferrous Gluconate 0.25 | Pomegranate Extract 0.001 | Glycerin 23.869 Base Part | Polyacrylate Crosspolymer-6 (Stabilizer) 0.03 | Caprylyl Glycol 0.2 | Ethanol 12 | Water 62.77 | Total 100

[0115] Experimental Example 5. Evaluation of physical properties and dyeing efficacy according to the ratio of dyed part and base part

[0116] When applying a two-part system using the dyeing part and base part of the hair dyeing composition prepared through Experimental Example 4, dyeing power and color stability were evaluated according to the ratio to select the optimal mixing ratio of the dyeing part and base part.

[0117] Specifically, the remainder was prepared in the same manner as in Experimental Example 4, and each sample was prepared by mixing the dyeing part and the base part in weight ratios of 1:20, 1:10, and 1:5. For each sample, the immediate dyeing power immediately after application and the color stability after storage at 50°C for one week were measured in the same manner as in Experimental Example 3, and the results are shown in Table 7.

[0118] Lightness (L*) Dye Part:Base Part 1:20 1:10 1:5 Immediately after dyeing 13 110 39 71 One week later 15 214 8136

[0119] Additionally, dyeing effect, transfer to hands, residue, formulation stability, and color stability were comprehensively compared and evaluated for each ratio, and the results are shown in Table 8 below (dyeing effect refers to the evaluation based on a comparison of the L values ​​in Table 7). For evaluation items in Table 8, being located further to the left indicates that the characteristic corresponding to the item is more strongly (higher) (e.g., in the case of transfer to hands, being located further to the left indicates a more severe degree of transfer).

[0120] Evaluation Criteria Rating High ← Medium → Low Dyeing Effect (Dyeing Power) (1:5) > (1:10) > (1:20) Smudge on Hands (1:5) > (1:10) > (1:20) Residue (1:5) > (1:10) > (1:20) Formulation Stability (1:20) > (1:10) > (1:5) Color Stability (1:20) > (1:10) > (1:5)

[0121] According to the experimental results in Tables 7 and 8, the 1:5 ratio showed excellent dyeing power, with an L value of 97 immediately after dyeing and 136 after storage at 50°C for one week, which was the lowest compared to other ratios. However, in terms of formulation stability, it was confirmed that residue was present on the hands even after a single use, and a noticeable residue was observed in terms of user experience.

[0122] On the other hand, for the 1:20 and 1:10 ratios, the L values ​​immediately after dyeing and after high-temperature storage were slightly higher compared to the 1:5 ratio, resulting in a relatively lower dyeing effect, but excellent results were observed in terms of formulation stability. In particular, at the 1:20 ratio, the degree of transfer to the hands was minimized, there was no clumping during mixing, and there was almost no residue, resulting in excellent usability. In the case of the 1:10 ratio, hand contamination was minimal with a single use, but transfer to the hands showed a noticeable tendency to increase with repeated use (Figs. 4a to 4c).

[0123] The hair dyeing composition of the present invention prepared in Experimental Example 4 can be used as a dyeing part alone or as a two-part system in which a dyeing part (first part) and a base part (second part) are mixed. To confirm the physical properties of the mixture of tannic acid, gallic acid, and ferrous gluconate in the dyeing part used in the two-part system, particle size analysis was performed using a laser particle size analyzer (LA-960 / LA-960V2 (A,S,D), Hriba, Ltd., Japan). Particle size analysis was performed three times per lot to calculate the average value, and the results are shown in Figures 4a to 4c.

[0124] Analysis using a laser particle size analyzer showed that a 1:2:1 mixture of tannic acid, gallic acid, and ferrous gluconate, which are the main components of the dyeing part, exhibited a particle size distribution of 10 to 50 μm. While this particle size range may appear relatively large compared to the total thickness of the hair cuticle (approx. 3–5 μm) ("Hair and Hair Care", Dale H. Johnson, Marcel Dekker, 1997), it is determined that the mixture is reconfigured to a size that can effectively penetrate into the hair when exposed to an aqueous environment during the actual hair dyeing process.

[0125] Those skilled in the art will be able to easily understand and implement, through the results of the above experimental example, that a stable and reproducible dyeing effect can be obtained by applying the particle size range (10 to 50 μm) of the mixture in the dyeing part, the weight ratio (1:2:1) of tannic acid, gallic acid, and divalent iron salt, and the optimal mixing conditions with the base part.

[0126] The hair dyeing composition of the present invention can be used as a single formulation or applied as a two-formulation system including a dyeing part and a base part, and is composed of tannic acid, gallic acid, and divalent iron salt in an optimal ratio to achieve superior dyeing power compared to conventional chemical hair dyes.

Claims

1. A dyeing part comprising polydihydroxyindole; and a mixture containing tannic acid, gallic acid, and a divalent iron salt; and A hair dyeing composition in which tannic acid, gallic acid, and divalent iron salt are mixed in a weight ratio of 1:1:1 to 1:5:1 in the above mixture.

2. In Paragraph 1, A hair dyeing composition comprising 0.001 to 10 weight percent of the polydihydroxyindole based on the total weight of the composition.

3. In Paragraph 1, A hair dyeing composition in which the above gallic acid is gallic acid or a derivative of gallic acid.

4. In Paragraph 1, A hair dyeing composition wherein the above-mentioned divalent iron salt is one or more selected from the group consisting of ferrous acetate, ferrous lactate, ferrous propionicate, ferrous fumarate, ferrous citrate, and ferrous gluconicate.

5. In Paragraph 1, A hair dyeing composition wherein the dyeing part further comprises polyol and pomegranate extract.

6. In Paragraph 5, A hair dyeing composition wherein the above polyol is one or more selected from the group consisting of glycerin, propanediol, 1,2-hexanediol, propylene glycol, and butylene glycol.

7. In Paragraph 1, A hair dyeing composition in which the dyeing part above does not contain water.

8. In Paragraph 1, A hair dyeing composition comprising a base part in addition to a dyeing part.

9. In Paragraph 8, A hair dyeing composition in which the dyeing part and base part have a weight ratio of 1:3 to 1:

20.

10. In Paragraph 1, The above composition is a hair dyeing composition in which the formulation is one or more selected from the group consisting of cream type, liquid type, powder type, jelly type, and aerosol type.

11. A dyeing part comprising polydihydroxyindole; and a mixture containing tannic acid, gallic acid, and a divalent iron salt; and A hair dyeing kit in which tannic acid, gallic acid, and divalent iron salt are mixed in a weight ratio of 1:1:1 to 1:5:1 in the above mixture.

12. In Paragraph 11, The above kit is a hair dyeing kit that includes a base part in addition to the dyeing part.

13. A cosmetic for hair dyeing comprising a composition of any one of claims 1 to 10.

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