Dyeing and protecting integrated hair dye and preparation method thereof

Abstract

The invention discloses a dyeing and protecting integrated hair dye and a preparation method thereof.The hair dye comprises an agent A, an agent B, an agent C and an agent D. The agent A comprises a reducing agent; the agent B comprises sulfydryl modified hyaluronic acid; the agent C comprises a melanin precursor; the agent D comprises an oxidizing agent; the sulfydryl modified hyaluronic acid is obtained by introducing a sulfydryl functional group on a hyaluronic acid molecular chain. The hair dye provided by the invention has good coloring efficiency and color fastness, the strength of dyed hair is remarkably improved, and the technical effect of synchronously performing hair dyeing and hair care is achieved.

Description

Technical Field

[0001] This invention relates to the field of cosmetic technology, and more specifically, to a hair dye that combines coloring and conditioning, and its preparation method. Background Technology

[0002] Traditional oxidative hair dyes primarily rely on phenylenediamine derivatives such as p-phenylenediamine (PPD) as dye intermediates, which react with oxidants to color the hair. However, these ingredients pose a high risk of sensitization, and their long-term safety is a major concern. Furthermore, the traditional hair dyeing process causes irreversible damage to hair, resulting in dryness, brittleness, and loss of shine.

[0003] While a few products claiming to combine coloring and conditioning in one technology exist, most simply add some conditioning ingredients (such as silicone oil and plant extracts) as a "post-treatment remedy," failing to fundamentally solve the problem of synergy between the coloring and conditioning processes. The coloring and conditioning ingredients operate independently, making it difficult to achieve true repair and protection during the critical window period when hair cuticles are open.

[0004] In view of this, the present invention is proposed. Summary of the Invention

[0005] This invention provides a hair dye that combines dyeing and conditioning, and its preparation method. The aim is to provide a novel hair dye that simultaneously repairs hair cuticles and strengthens hair structure during the dyeing process.

[0006] This invention is implemented as follows: In a first aspect, the present invention provides a hair dye that combines dyeing and conditioning, the hair dye comprising agent A, agent B, agent C and agent D, wherein agent A comprises a reducing agent; agent B comprises thiol-modified hyaluronic acid; agent C comprises a melanin precursor; and agent D comprises an oxidizing agent; wherein the thiol-modified hyaluronic acid refers to hyaluronic acid by introducing thiol functional groups onto the hyaluronic acid molecular chain.

[0007] The hair dye provided by this invention has good coloring efficiency and color fastness, and the strength of the dyed hair is significantly improved, with the breaking strength increased by 12% to 22%. In this process, Agent A opens the disulfide bonds of keratin on the hair surface, reversibly opening the hair cuticle structure and providing a time window for the targeted penetration of thiol-modified hyaluronic acid in Agent B and the dynamic recombination of disulfide bonds in hair keratin. Utilizing the good affinity between hyaluronic acid segments and hair, Agent B is efficiently adsorbed and anchored to the keratin surface of the hair in the open cuticle state. The thiol groups undergo a dynamic exchange reaction with the free thiol groups / disulfide bonds of keratin, resulting in the chemical bonding of thiol-modified hyaluronic acid to the keratin surface. Then, the melanin precursor in Agent C undergoes an in-situ polymerization reaction on the hair surface under the alkaline oxidizing environment provided by Agent D, generating melanin-like pigments. The free thiol groups (-SH) on the thiol-modified hyaluronic acid participate in the polymerization reaction of the melanin precursor through an addition reaction with the quinone groups of the melanin precursor, thereby enhancing the binding strength of melanin-like pigments to hair. In other words, thiol-modified hyaluronic acid acts as a medium to link hair keratin and melanin-like pigments, thereby improving the color fastness and coloring efficiency of melanin-like pigments. Furthermore, hyaluronic acid itself possesses excellent moisturizing, film-forming, and biocompatibility properties, forming a flexible protective film on the hair surface to physically block external damaging factors. Additionally, the multi-thiol molecular chain structure of thiol-modified hyaluronic acid reversibly participates in disulfide bond recombination, repairing disulfide bonds damaged by oxidants through multi-site dynamic cross-linking, thus rebuilding the mechanical strength of the hair from within and significantly improving its tensile strength. Through the above process, the hair dye provided by this invention can achieve a one-stop solution for coloring and conditioning, and improves coloring efficiency and color fastness.

[0008] In some embodiments, the grafting rate of thiol groups in the thiol-modified hyaluronic acid is 0.35~0.7 mmol / g. This grafting rate is beneficial for achieving high efficiency and controllability of the dynamic exchange reaction of thiol groups. Excessive thiol density leads to excessive cross-linking between hyaluronic acid segments, reducing its permeability and flexible film-forming ability. Conversely, a grafting rate below 0.35 mmol / g is insufficient to support the dynamic recombination of multi-site disulfide bonds and the effective anchoring of melanin precursors, resulting in insufficient improvement in color fastness and a decreased increase in elongation at break. Maintaining a thiol grafting rate of 0.35~0.7 mmol / g facilitates targeted penetration, dynamic anchoring, and initial cross-linking, providing a structural basis and reaction interface for subsequent in-situ polymerization of the C agent.

[0009] In some embodiments, the molecular weight of the thiol-modified hyaluronic acid is 5-2000 kDa; preferably 50-500 kDa. If the molecular weight is too low, the film-forming properties and steric hindrance protection are insufficient; if it is too high, the permeability decreases and it is difficult to penetrate deep into the hair cortex. This molecular weight range, combined with a grafting rate of 0.35-0.7 mmol / g, ensures a moderate thiol density and sufficient chain segment flexibility, meeting the needs of multi-point dynamic cross-linking repair while maintaining good water solubility and keratin interface adsorption kinetics.

[0010] In some embodiments, the pH of agent A is 8.5-9.5; the pH of agent B is 6-7; the pH of agent C is 6-7; and the pH of agent D is 5-9. The pH of agent A, B, C, or D is adjusted using a pH adjuster or a pH buffer. The pH adjuster is at least one of ammonia, triethanolamine, diethanolamine, monoethanolamine, sodium hydroxide, sodium carbonate, citric acid, acetic acid, hydrochloric acid, and sodium citrate. The pH buffer is a citric acid / sodium citrate buffer or a phosphate buffer.

[0011] In some embodiments, agent B and / or agent C further include melanin precursor-modified keratin polypeptides, wherein the melanin precursor-modified keratin polypeptides refer to keratin polypeptides whose chains are chemically modified with melanin precursors. Preferably, the method for preparing the melanin precursor-modified keratin polypeptide includes the following steps: dispersing hydrolyzed keratin in a pH buffer, adding carbodiimide hydrochloride and N-hydroxysuccinimide, reacting at pH 5.0-6.5 and 37°C for 24 h, dialysis purification, and lyophilizing to obtain the melanin precursor-grafted keratin polypeptide; more preferably, the keratin polypeptide has a molecular weight of less than or equal to 2500 Da and is obtained by enzymatic hydrolysis from wool keratin and purification. Melanin precursor modified keratin peptides can penetrate deep into the hair cortex based on the principle of like dissolves like, and embed themselves into the gaps between damaged keratin through hydrophobic interactions. The grafted melanin precursors simultaneously participate in the in-situ polymerization of C-agent melanin precursors, enabling the repair sites and coloring sites to be spatially co-located, thereby synchronizing structural repair and pigment deposition and improving the tensile strength and flexibility of hair.

[0012] In some embodiments, the reducing agent is thioglycolate or cysteine ​​hydrochloride; And / or, the melanin precursor is selected from one or more combinations of tyrosine, L-DOPA, acetyltyrosine, oleyltyrosine, dopaquinone, dopachrome, 5,6-dihydroxyindole, 5,6-dihydroxyindole-2-carboxylic acid, dopamine hydrochloride and cysteine ​​dopa. And / or, the oxidant is selected from sodium bromate, periodate, persulfate or hydrogen peroxide.

[0013] In some embodiments, agent C further includes a plant-derived melanin precursor selected from one or more combinations of walnut husk extract, black sesame extract, mulberry extract, black soybean seed coat extract, black goji berry anthocyanin, and purple sweet potato anthocyanin.

[0014] In some embodiments, the preparation method of the thiol-modified hyaluronic acid is as follows: sodium hyaluronate is dissolved in water, carbodiimide hydrochloride and N-hydroxysuccinimide are added, and the reaction is carried out at 25°C for 0.5-1 h under nitrogen protection. Then cysteine ​​is added, and the pH is adjusted to 7-8. The reaction is continued to be stirred for 4-12 h. The resulting reaction solution is dialyzed through a dialysis bag with a molecular weight cutoff of 3.5 kDa for 48 h, and then freeze-dried to obtain thiol-modified hyaluronic acid. The thiol grafting rate is determined by the Ellman method to be 0.35-0.7 mmol / g. The molecular weight of the sodium hyaluronate is 5-2000 kDa, preferably 50-500 kDa, which has both film-forming and permeability properties.

[0015] In some embodiments, agent A comprises 6 wt% to 10 wt% reducing agent, 3 wt% to 6 wt% thickener, 0.5 wt% to 1 wt% antioxidant, 0.1 wt% to 0.5 wt% chelating agent and 3 wt% to 5 wt% humectant; And / or, the agent B comprises: 1wt%~3wt% mercapto-modified hyaluronic acid, 0wt%~3wt% melanin precursor modified keratin peptide, 1wt%~5wt% penetration enhancer, 5wt%~10wt% moisturizer, 0.5wt%~1.5wt% thickener and 0.5wt%~1.5wt% antioxidant; And / or, the C agent comprises: 1wt%~3wt% melanin precursor, 0~3wt% plant-derived melanin precursor, 0~3wt% melanin precursor modified keratin polypeptide, 0.5wt%~1wt% antioxidant, 0.3wt%~1.5wt% surfactant, 3wt%~8wt% humectant, 0.5wt%~1.5wt% thickener and 0.1wt%~0.2wt% chelating agent; And / or, the D agent comprises: 0.15wt%~15wt% oxidant, 0~0.5wt% surfactant, 4wt%~8wt% thickener, 0~1.5wt% stabilizer and 0~3wt% conditioning agent.

[0016] In some embodiments, the thickener is selected from at least one of cetyl alcohol, stearyl alcohol, emulsifying wax, hydroxyethyl cellulose, xanthan gum, and carbomer; the addition of a thickener facilitates the coating and retention of active ingredients on the hair surface, thereby improving the hair dyeing effect.

[0017] In some embodiments, the stabilizer is selected from sodium stannate or sodium pyrophosphate; the stabilizer can improve the stability of the oxidant and prevent its decomposition.

[0018] In some embodiments, the chelating agent is selected from at least one of disodium EDTA, tetrasodium EDTA, sodium citrate, and sodium gluconate; the chelating agent can chelate metal ions in water to prevent them from affecting the stability of the reducing agent and the subsequent staining effect.

[0019] In some embodiments, the humectant is selected from at least one of glycerin, propylene glycol, butylene glycol, panthenol, sorbitol, and trehalose; the humectant acts to retain moisture and reduce the dryness damage to the hair caused by the reducing agent.

[0020] In some embodiments, the surfactant is selected from at least one of cetearyl alcohol polyether-25, PEG-40 hydrogenated castor oil, and alkyl glycosides (such as APG0810 and APG1214). And / or, the antioxidant is selected from at least one of ascorbic acid or its derivatives and sodium sulfite; And / or, the penetration enhancer is selected from at least one of azone or its derivatives and propylene glycol; And / or, the conditioning agent is selected from at least one of cationic guar gum, polyquaternium-10, polyquaternium-7, silicone oil, hydrolyzed protein, and phytosterol esters.

[0021] Secondly, the present invention provides a method for preparing any of the above-mentioned hair dyes, comprising the following steps: preparing agent A: dissolving a reducing agent in water, adding a pH adjuster to adjust to 8.5-9.5 to obtain agent A; preparing agent B: dissolving thiol-modified hyaluronic acid in a pH buffer solution of pH=6-7, stirring to dissolve to obtain agent B; preparing agent C: dissolving a melanin precursor in a pH buffer solution of pH=6-7, stirring to dissolve to obtain agent C; preparing agent D: mixing an oxidizing agent with water evenly, adding a pH adjuster to adjust to pH 5-9 to obtain agent D.

[0022] In some embodiments, the preparation of Agent A includes the following steps: premixing a thickener with water and heating it to 60-70°C to allow it to swell fully; cooling it to below 40°C and then adding a reducing agent, an antioxidant, a chelating agent, and a humectant; stirring to dissolve the mixture; adding a pH adjuster to adjust it to 8.5-9.5; and then ultrasonically degassing the mixture to obtain Agent A.

[0023] In some embodiments, the preparation of Agent B includes the following steps: premixing a thickener with a pH buffer and heating it to 60-70°C to allow it to swell fully; cooling it to below 40°C and then adding thiol-modified hyaluronic acid, a penetration enhancer, a humectant, and an antioxidant; stirring to dissolve the mixture; adding a melanin precursor-modified keratin peptide and stirring until homogeneous; and then ultrasonically degassing the mixture to obtain Agent B.

[0024] In some embodiments, the preparation of Agent C includes the following steps: premixing a thickener with a pH buffer and heating it to 60-70°C to allow it to swell fully; cooling it to below 40°C and then adding a melanin precursor, a plant-derived melanin precursor, and a surfactant; homogenizing the mixture and then adding a humectant, a chelating agent, and an antioxidant; stirring to dissolve the mixture; then adding a melanin precursor-modified keratin peptide and stirring until homogeneous; and finally ultrasonically degassing the mixture to obtain Agent C.

[0025] In some embodiments, the preparation of Agent D includes the following steps: premixing a thickener with water and heating it to 60-70°C to allow it to swell fully; cooling it to below 40°C and then adding a stabilizer, surfactant, and conditioning agent; homogenizing the mixture and then adding an oxidant and a pH adjuster to adjust the pH to 5-9; and finally degassing the mixture using ultrasound to obtain Agent D.

[0026] Thirdly, the present invention provides the application of any of the above-mentioned hair dyes, comprising the following steps: (1) after washing the hair, applying agent A to the hair at 25~40°C and letting it stand for 10~30 minutes; (2) applying agent B to the hair at 25~40°C and letting it stand for 5~15 minutes, then rinsing the hair with clean water; (3) mixing agent C and agent D at a mass ratio of 1:1, applying the mixture to the hair and maintaining it at 25~50°C for 30~90 minutes; rinsing the hair with clean water, drying it, and then completing the hair dyeing process.

[0027] The present invention has the following beneficial effects: The hair dye provided by this invention has good coloring efficiency and color fastness, and the strength of the dyed hair is significantly improved, achieving the technical effect of simultaneous hair dyeing and hair care. Attached Figure Description

[0028] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0029] Figure 1 The UV absorption spectra of hydrolyzed keratin, pDA-1 (left), and pDA-2 (right); Figure 2 SEM images of gray hair before dyeing, and hair dyed samples from Example 1 and Comparative Examples 1-4. Detailed Implementation

[0030] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall apply. Reagents or instruments whose manufacturers are not specified are all conventional products that can be purchased commercially.

[0031] In the description of the embodiments of this application, the technical terms "first" and "second" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly indicating the number, specific order, or primary and secondary relationship of the indicated technical features.

[0032] The term "embodiment" in this document means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment that is mutually exclusive with other embodiments.

[0033] In the embodiments of this application, the term "or / and" is only a description of the relationship between related objects, indicating that there can be three kinds of relationships. For example, A or / and B can represent three situations: A exists alone, A and B exist at the same time, and B exists alone.

[0034] Additionally, the character " / " in this article generally indicates that the objects before and after it are in an "or" relationship.

[0035] In the embodiments of this application, "multiple" means two or more (including two), similarly, "multiple groups" means two or more (including two groups), and "multiple layers" means two or more (including two layers), unless otherwise explicitly specified and limited.

[0036] In the embodiments of this application, "at least one" means one or more.

[0037] In the embodiments of this application, "wt%" means mass percentage content, and "%" means mass percentage content unless otherwise specified.

[0038] Those skilled in the art can understand the specific meaning of the above terms in the embodiments of this application according to the specific circumstances.

[0039] The features and performance of the present invention will be further described in detail below with reference to embodiments.

[0040] [Thiol-modified hyaluronic acid] Thiol-modified hyaluronic acid refers to hyaluronic acid compounds that introduce thiol (-SH) functional groups into the hyaluronic acid molecular chain. This compound utilizes the good affinity of hyaluronic acid for hair to promote its adsorption on the hair surface, thereby promoting the dynamic exchange reaction of thiol-keratin disulfide bonds between the modified thiol groups and hair keratin, achieving anchoring and multi-point repair. Hair treated with thiol-modified hyaluronic acid serves as a base, allowing melanin precursors to grow in situ on its surface, improving coloring efficiency and color fastness.

[0041] In some embodiments, thiol-modified hyaluronic acid can be obtained by esterification reaction of hyaluronic acid with thioglycolic acid or thiopropionic acid.

[0042] In some embodiments, thiol-modified hyaluronic acid can be obtained by acylation of cysteine ​​with hyaluronic acid.

[0043] In one embodiment, the preparation method of thiol-modified hyaluronic acid is as follows: Sodium hyaluronate is dissolved in water, and EDC (1-ethyl-3-(3-dimethylaminopropyl)carbodiimide) and NHS (N-hydroxysuccinimide) are added. The mixture is stirred at 25°C for 0.5 h under nitrogen protection. Then, cysteine ​​and sodium hydroxide solution are added to adjust the pH to 7.2, and the reaction is continued to be stirred for 6 h. The resulting reaction solution is concentrated and dialyzed through a dialysis bag with a molecular weight cutoff of 3.5 kDa for 48 h. The solution is then freeze-dried to obtain thiol-modified hyaluronic acid. The reaction conditions and structural information of thiol-modified hyaluronic acid with different molecular structures are shown in Table 1.

[0044] Table 1

[0045] Sodium hyaluronate was purchased from Bloomage Biotechnology; the thiol grafting rate was determined by the Ellman method.

[0046] [Melanin precursor modified keratin peptide] Melanin precursor modified keratin peptides refer to keratin peptides whose chains are chemically modified with melanin precursors. This is usually achieved through covalent coupling by condensation reactions between the carboxyl, amino, and hydroxyl groups on the melanin precursor and the amino, carboxyl, and hydroxyl groups on the amino acid residues of the keratin peptide.

[0047] Melanin precursor modified keratin peptides can penetrate deep into the hair cortex based on the principle of like dissolves like, and embed themselves into the gaps between damaged keratin through hydrophobic interactions. The grafted melanin precursors simultaneously participate in the in-situ polymerization of C-agent melanin precursors, enabling the repair sites and coloring sites to be spatially co-located, thereby synchronizing structural repair and pigment deposition and improving the tensile strength and flexibility of hair.

[0048] Melanin precursors are selected from one or more combinations of tyrosine, L-DOPA, acetyltyrosine, oleotyrosine, dopaquinone, dopachrome, 5,6-dihydroxyindole, 5,6-dihydroxyindole-2-carboxylic acid, dopamine hydrochloride, and cysteine-dopa.

[0049] Keratin polypeptides, also known as hydrolyzed keratin, have a molecular weight of ≤2500 Da. They are obtained by hydrolyzing animal hair, preferably by extracting and purifying wool keratin using enzymatic hydrolysis.

[0050] In some embodiments, the preparation method of melanin precursor-modified keratin peptides includes the following steps: hydrolyzed keratin and melanin precursor are dissolved in 2-morpholinoethanesulfonic acid (MES) buffer (pH=5.8), EDC and NHS are added, and the reaction is stirred at 25°C under a nitrogen atmosphere for 24 h. The resulting reaction solution is concentrated, dialyzed through a dialysis bag for 48 h, and freeze-dried to obtain melanin precursor-grafted keratin peptides. The reaction conditions for melanin precursor-modified keratin peptides with different molecular structures are shown in Table 2.

[0051] Table 2

[0052] Keratin polypeptide (hydrolyzed keratin) was purchased from Wuhan Pushida Biotechnology Co., Ltd.

[0053] The UV absorption spectra of hydrolyzed keratin, pDA-1, and pDA-2 are attached. Figure 1 As shown in the figure, both the modified and unmodified products exhibit characteristic absorption peaks around 280 nm, which are attributed to the absorption of the conjugated structure of the aromatic ring. Furthermore, the absorption peak intensity of the modified product is significantly enhanced, indicating that the melanin precursor has been successfully grafted onto the keratin polypeptide backbone.

[0054] Examples 1-5 provide a hair dye that combines coloring and conditioning, prepared using HAS-1, HAS-2, HAS-3, HAS-4, and HAS-5 as thiol-modified hyaluronic acid. The hair dye that combines coloring and conditioning includes agent A, agent B, agent C, and agent D, and the preparation method is as follows: Preparation of Agent A: Dissolve ammonium thioacetate in water, add monoethanolamine to adjust the pH to 9, and obtain Agent A with an ammonium thioacetate concentration of 8 wt%; Preparation of Agent B: Dissolve thiol-modified hyaluronic acid in a citric acid-sodium citrate buffer solution at pH=6, and stir to dissolve to obtain Agent B with a thiol-modified hyaluronic acid concentration of 2wt%. Preparation of Agent C: Dopamine hydrochloride was dissolved in a citrate-sodium citrate buffer solution at pH=6, and after stirring and dissolving, Agent C with a concentration of 3% dopamine hydrochloride was obtained; Preparation of Agent D: Add 30 wt% hydrogen peroxide to Tris-HCl buffer solution at pH=8 to make the final concentration of hydrogen peroxide 0.15 wt%, and then adjust the pH to 8 to obtain Agent D.

[0055] Comparative Example 1 The difference from Example 1 is that the hair dye does not contain Agent B, and step (2) is omitted in the method of use.

[0056] Comparative Example 2 The difference from Example 1 is that in Agent B of the hair dye, dopamine-modified hyaluronic acid is used instead of thiol-modified hyaluronic acid.

[0057] The preparation method of dopamine-modified hyaluronic acid is as follows: Sodium hyaluronate is dissolved in water, and EDC (1-ethyl-3-(3-dimethylaminopropyl)carbodiimide) and NHS (N-hydroxysuccinimide) are added. The mixture is stirred at 25°C for 0.5 h under nitrogen protection. Then, dopamine hydrochloride and sodium hydroxide solution are added to adjust the pH to 7.5, and the reaction is continued to be stirred for 6 h. The resulting reaction solution is concentrated and dialyzed through a dialysis bag with a molecular weight cutoff of 3.5 kDa for 48 h. The resulting hyaluronic acid is freeze-dried to obtain dopamine-modified hyaluronic acid. The mass ratio of sodium hyaluronate, EDC, NHS, and dopamine hydrochloride is 1:0.15:0.11:0.1; the molecular weight of sodium hyaluronate is 100 kDa.

[0058] Comparative Example 3 The difference from Example 1 is that in Agent B of the hair dye, a mixture of equal mass of cysteine ​​and sodium hyaluronate is used to replace thiol-modified hyaluronic acid, and the molar ratio of the added cysteine ​​to the molar ratio of thiol in the thiol-modified hyaluronic acid of Example 1 is 1:1.

[0059] Comparative Example 4 The difference from Example 1 is that in Agent B of the hair dye, a coupling compound of cystine and dopamine is used instead of thiol-modified hyaluronic acid, and the coupling compound of cystine and dopamine is added in a ratio of 1:1 to the sulfur element of the thiol-modified hyaluronic acid in Example 1.

[0060] The hair dyes prepared in Examples 1-5 and Comparative Examples 1-4 were used for hair dyeing. The white hair to be dyed (white hair before dyeing) was artificially bleached hair. The method of use is as follows: (1) Wash the white hair to be dyed with 5wt% SDS solution 3 times, and then rinse with deionized water to remove sebum from the hair surface; then soak the hair sample in agent A at 25℃, let it stand for 20 minutes, take it out and use non-woven fabric to absorb excess water so that the hair no longer drips. (2) At 25°C, soak the hair obtained in step (1) in agent B, let it stand for 10 minutes, rinse with water, and use non-woven fabric to absorb excess water so that the hair no longer drips. (3) At 25°C, mix agent C and agent D at a mass ratio of 1:1, immerse the hair obtained in step (2) in the mixture and keep it for 60 minutes, take it out and rinse it with water, and then air dry it indoors to complete the hair dyeing process.

[0061] The following tests were conducted on the hair dye: (1) Scanning electron microscope (SEM) SEM images of undyed gray hair, hair dyed samples from Example 1, and comparative examples 1-4 are attached. Figure 2 As shown in the figure, it can be seen that the hair cuticles of Comparative Examples 1, 3, and 4, and the hair dyeing of pre-dye white hair (artificial bleaching) are significantly damaged. This indicates that the addition of thiol-modified hyaluronic acid in this invention has a significant effect on repairing hair cuticles.

[0062] (2) Hair color The color coordinates, including L, a, and b, were measured using an NR60CP colorimeter, and the hair dye color was analyzed using the Lab color model. L represents the brightness value within the range [0, 100], indicating a color change from pure black to pure white; a represents the chromaticity from red (positive) to green (negative), with a value range of [127, -128]; b represents the chromaticity from yellow (positive) to blue (negative), with a value range of [127, -128]. The color difference ΔE = [(L*-L] 2 +(a*-a) 2 +(b*-b) 2 ] 1 / 2 Where L, a, and b are the values ​​of gray hair before dyeing, and L*, a*, and b* are the values ​​of the sample to be tested. Measurements were taken at 5 locations for each sample, and the average values ​​were calculated. The results are shown in Table 3.

[0063] Table 3

[0064] As shown in Table 3, the hair dye provided by this invention can effectively dye gray hair, and the dyeing efficiency is higher than that of Comparative Example 1. A comparison of Examples 1-5 shows that the higher the thiol content of the thiol-modified hyaluronic acid, the greater the color difference, i.e., the higher the dyeing efficiency. This is because more thiol groups are more conducive to the thiol-dopamine reaction, increasing the adsorption of melanin precursors on the hair surface. Conversely, the smaller the molecular weight of the thiol-modified hyaluronic acid, the greater the color difference, i.e., the higher the dyeing efficiency. This is because a lower molecular weight facilitates molecular penetration and adsorption onto hair keratin.

[0065] (3) Color fastness The hair dyed sample was immersed in a 5% (v / v) commercially available shampoo solution. The test tube was shaken with a vortex mixer for 1 minute. The hair sample was then rinsed with tap water and dried with cold air. The color difference value (∆E) was measured every 10 washes, for a total of 30 washes. The results are shown in Table 4.

[0066] Table 4

[0067] As shown in Table 4, the hair dye provided by this invention has higher color fastness compared to Comparative Examples 1-3. After 10 washes, the average color difference retention rate of the examples was 96.136%, compared to 90.42% for Comparative Example 1, 92.16% for Comparative Example 2, and 93.06% for Comparative Example 3. Comparative Example 2 used dopamine-modified hyaluronic acid instead of thiol-modified hyaluronic acid, which could not chemically bond to the hair surface, and the melanin-like pigments were only physically adsorbed, resulting in a significant decrease in color fastness. Comparative Example 3 used a mixture of cystine and hyaluronic acid instead of thiol-modified hyaluronic acid. The hyaluronic acid was not chemically bonded to the hair surface and had good water solubility, so it was easily washed out after washing, resulting in the loss of the protective film effect.

[0068] (4) Hair tensile strength: The tensile properties of hair were tested using a single fiber strength tester, and the hair diameter was measured using a microscope. The clamping distance and stretching rate were 30 mm and 20 mm / min, respectively. Thirty sets of parallel data were tested for each sample, and the average value was calculated. The test results are shown in Table 5.

[0069] Table 5

[0070] As shown in Table 5, the tensile strength of the dyed hair in all embodiments of the present invention was significantly higher than that of the undyed gray hair and all comparative examples. Example 3 showed the most significant increase, reaching 238 MPa, a 22.1% improvement compared to the undyed hair. In contrast, the increases in comparative examples 1-4 were only 6.7%-10.3%, indicating that the thiol-modified hyaluronic acid forms stable covalent bonds with the hair surface, effectively repairing and strengthening the keratin structure. This result is consistent with... Figure 2 The test results are consistent.

[0071] Examples 6-8 provide a hair dye that combines coloring and conditioning. The hair dye is prepared using HAS-2 as a thiol-modified hyaluronic acid, and pDA-1, pDA-2, and pDA-3 as melanin precursors modified keratin peptides, respectively. The hair dye that combines coloring and conditioning includes agents A, B, C, and D, and is prepared using the following method: Preparation of Agent A: Dissolve ammonium thioacetate in water, add monoethanolamine to adjust the pH to 9, and obtain Agent A with an ammonium thioacetate concentration of 8 wt%; Preparation of Agent B: HAS-2 was dissolved in a citrate-sodium citrate buffer solution at pH=6, and after stirring and dissolving, Agent B with a concentration of 2wt% thiol-modified hyaluronic acid was obtained. Preparation of Agent C: Dopamine hydrochloride and melanin precursor modified keratin peptides were dissolved in citrate-sodium citrate buffer at pH=6. After stirring and dissolving, Agent C with a concentration of 3% dopamine hydrochloride and a concentration of 1.2 wt% melanin precursor modified keratin peptides was obtained. Preparation of Agent D: Add 30 wt% hydrogen peroxide to Tris-HCl buffer solution at pH=8 to make the final concentration of hydrogen peroxide 0.15 wt%, and then adjust the pH to 8 to obtain Agent D.

[0072] The hair dyes from Examples 6-8 were used in the same dyeing method to obtain hair dyes, and the performance of the dyes was tested. The results are shown in Table 6.

[0073] Table 6

[0074] As can be seen from Table 6, the performance of hair dyes is improved in all aspects after the addition of melanin precursor modified keratin peptides. Among them, pDA-1 has the best effect, because pDA-2 and pDA-3 have poor penetration and adsorption effects.

[0075] Example 9

[0076] This embodiment provides a hair dye that combines coloring and conditioning, including agent A, agent B, agent C, and agent D; the preparation method is as follows: Preparation of Agent A: Hydroxyethyl cellulose was premixed with water and heated to 60°C to allow it to swell fully. After cooling to below 40°C, ammonium thioglycolate, ascorbic acid, disodium EDTA, and glycerol were added. After stirring to dissolve, monoethanolamine was added to adjust the pH to 9. After ultrasonic degassing, Agent A was obtained. In the obtained Agent A, the mass percentages of hydroxyethyl cellulose, ammonium thioglycolate, ascorbic acid, disodium EDTA, and glycerol were 3%, 6%, 0.5%, 0.5%, and 5%, respectively.

[0077] Preparation of Agent B: Prepare a citrate-sodium citrate buffer solution with pH=6, add hydroxyethyl cellulose and heat to 60℃ to allow it to swell fully, cool to below 40℃ and then add mercapto-modified hyaluronic acid (HAS-2), propylene glycol, panthenol, glycerol and ascorbic acid, stir to dissolve and then sonicate to remove bubbles to obtain Agent B; In the obtained Agent B, the mass percentages of hydroxyethyl cellulose, HAS-2, propylene glycol, panthenol, glycerol and ascorbic acid are 0.5%, 3%, 5%, 1%, 4% and 1.5%, respectively.

[0078] Preparation of Agent C: A citrate-sodium citrate buffer solution with pH=6 was prepared. Hydroxyethyl cellulose was added and heated to 60°C to allow it to fully swell. After cooling to below 40°C, melanin precursor, black sesame extract, and cetearyl alcohol polyether-25 were added. After homogenization, glycerol, disodium EDTA, and ascorbic acid were added and stirred to dissolve. Then, pDA-1 was added and stirred evenly. After ultrasonic degassing, Agent C was obtained. The melanin precursor was a mixture of levodopa and dopamine hydrochloride in a mass ratio of 1:1. In the obtained Agent C, the mass percentages of hydroxyethyl cellulose, melanin precursor, black sesame extract, cetearyl alcohol polyether-25, glycerol, disodium EDTA, ascorbic acid, and pDA-1 were 1.5%, 3%, 1%, 1.5%, 5%, 0.2%, 1%, and 1%, respectively.

[0079] Preparation of Agent D: Hydroxyethyl cellulose was premixed with water and heated to 60°C to allow it to swell fully. After cooling to below 40°C, sodium stannate and polyquaternium-10 were added. After homogenization, sodium bromate and citric acid were added to adjust the pH to 6. After ultrasonic degassing, Agent D was obtained. In the obtained Agent D, the mass percentages of hydroxyethyl cellulose, sodium stannate, polyquaternium-10, and sodium bromate were 4%, 0.5%, 1%, and 8%, respectively.

[0080] Example 10

[0081] This embodiment provides a hair dye that combines coloring and conditioning, including agent A, agent B, agent C, and agent D; the preparation method is as follows: Preparation of Agent A: Carbomer 1342 was premixed with water and heated to 60°C to allow it to swell fully. After cooling to below 40°C, ammonium thioglycolate, ascorbic acid, disodium EDTA, and glycerol were added. After stirring to dissolve, triethanolamine was added to adjust the pH to 9. After ultrasonic degassing, Agent A was obtained. In the obtained Agent A, the mass percentages of carbomer 1342, ammonium thioglycolate, ascorbic acid, disodium EDTA, and glycerol were 6%, 10%, 1%, 0.1%, and 3%, respectively.

[0082] Preparation of Agent B: Prepare a citrate-sodium citrate buffer solution with pH=6, add carbomer 1342 and heat to 60℃ to allow it to swell fully. After cooling to below 40℃, add mercapto-modified hyaluronic acid (HAS-2), propylene glycol, panthenol, glycerol and ascorbic acid. Stir to dissolve and then sonicate to remove bubbles to obtain Agent B. In the obtained Agent B, the mass percentages of carbomer 1342, HAS-2, propylene glycol, panthenol, glycerol and ascorbic acid are 1.5%, 1%, 1%, 2%, 8% and 0.5%, respectively.

[0083] Preparation of Agent C: A citrate-sodium citrate buffer solution with pH=6 was prepared. Carbomer 1342 was added and heated to 60℃ to allow it to swell fully. After cooling to below 40℃, melanin precursor, walnut husk extract, mulberry extract, and cetearyl alcohol polyether-25 were added. After homogenization, glycerol, disodium EDTA, and ascorbic acid were added and stirred to dissolve. Then, pDA-1 was added and stirred evenly. After ultrasonic degassing, Agent C was obtained. The melanin precursor was a mixture of levodopa and dopamine hydrochloride in a mass ratio of 1:1. In the obtained Agent C, the mass percentages of carbomer 1342, melanin precursor, walnut husk extract, mulberry extract, cetearyl alcohol polyether-25, glycerol, disodium EDTA, ascorbic acid, and pDA-1 were 0.5%, 1%, 1%, 2%, 0.3%, 3%, 0.1%, 0.5%, and 3%, respectively.

[0084] Preparation of Agent D: Carbomer 1342 was premixed with water and heated to 60°C to allow it to swell fully. After cooling to below 40°C, sodium stannate, hydrolyzed silk fibroin (Wuhan Pushida Biotechnology Co., Ltd.), and polyquaternium-10 were added. After homogenization, sodium bromate and citric acid were added to adjust the pH to 6. After ultrasonic degassing, Agent D was obtained. In the obtained Agent D, the mass percentages of carbomer 1342, sodium stannate, hydrolyzed silk fibroin, polyquaternium-10, and sodium bromate were 8%, 1.5%, 1%, 1%, and 8%, respectively.

[0085] The hair dyes from Examples 9 and 10 were used in the same dyeing method to obtain hair dyes, and the performance of the dyes was tested. The results are shown in Table 7.

[0086] Table 7

[0087] As can be seen from Table 7, the hair dye provided by the present invention has good color fastness and coloring efficiency, and also has hair care effects, which can improve the mechanical strength of hair.

[0088] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A hair dye that combines coloring and conditioning, characterized in that, It includes Agent A, Agent B, Agent C, and Agent D, wherein Agent A includes a reducing agent; Agent B includes thiol-modified hyaluronic acid; Agent C includes a melanin precursor; and Agent D includes an oxidizing agent; wherein the thiol-modified hyaluronic acid refers to hyaluronic acid by introducing thiol functional groups onto the hyaluronic acid molecular chain.

2. The hair dye that combines coloring and conditioning according to claim 1, characterized in that, The grafting rate of thiol groups in the thiol-modified hyaluronic acid is 0.35~0.7 mmol / g; And / or, the molecular weight of the thiol-modified hyaluronic acid is 5~2000 kDa; And / or, the pH of agent A is 8.5-9.5; the pH of agent B is 6-7; the pH of agent C is 6-7; the pH of agent D is 5-9; the pH of agent A, agent B, agent C, or agent D is adjusted using a pH adjuster or a pH buffer, wherein the pH adjuster is at least one of ammonia, triethanolamine, diethanolamine, monoethanolamine, sodium hydroxide, sodium carbonate, citric acid, acetic acid, hydrochloric acid, and sodium citrate; and the pH buffer is a citric acid / sodium citrate buffer or a phosphate buffer.

3. The hair dye that combines coloring and conditioning according to claim 1, characterized in that, The B agent and / or C agent further includes melanin precursor modified keratin polypeptide, wherein the melanin precursor modified keratin polypeptide refers to the keratin polypeptide chain segment chemically modified with melanin precursor.

4. The hair dye that combines coloring and conditioning according to claim 1, characterized in that, The reducing agent is thioglycolate or cysteine ​​hydrochloride; And / or, the melanin precursor is selected from one or more combinations of tyrosine, L-DOPA, acetyltyrosine, oleyltyrosine, dopaquinone, dopachrome, 5,6-dihydroxyindole, 5,6-dihydroxyindole-2-carboxylic acid, dopamine hydrochloride and cysteine ​​dopa. And / or, the oxidant is selected from sodium bromate, periodate, persulfate or hydrogen peroxide.

5. A hair dye that combines coloring and conditioning according to claim 1, characterized in that, Agent C also includes plant-derived melanin precursors selected from one or more combinations of walnut husk extract, black sesame extract, mulberry extract, black soybean seed coat extract, black goji berry anthocyanin, and purple sweet potato anthocyanin.

6. A hair dye that combines coloring and conditioning according to claim 1, characterized in that, The A agent comprises 6wt%~10wt% reducing agent, 3wt%~6wt% thickener, 0.5wt%~1wt% antioxidant, 0.1wt%~0.5wt% chelating agent and 3wt%~5wt% humectant; And / or, the agent B comprises: 1wt%~3wt% mercapto-modified hyaluronic acid, 0wt%~3wt% melanin precursor modified keratin peptide, 1wt%~5wt% penetration enhancer, 5wt%~10wt% moisturizer, 0.5wt%~1.5wt% thickener and 0.5wt%~1.5wt% antioxidant; And / or, the C agent comprises: 1wt%~3wt% melanin precursor, 0~3wt% plant-derived melanin precursor, 0~3wt% melanin precursor modified keratin polypeptide, 0.5wt%~1wt% antioxidant, 0.3wt%~1.5wt% surfactant, 3wt%~8wt% humectant, 0.5wt%~1.5wt% thickener and 0.1wt%~0.2wt% chelating agent; And / or, the D agent comprises: 0.15wt%~15wt% oxidant, 0~0.5wt% surfactant, 4wt%~8wt% thickener, 0~1.5wt% stabilizer and 0~3wt% conditioning agent.

7. A hair dye that combines coloring and conditioning according to claim 6, characterized in that, The thickener is selected from at least one of cetyl alcohol, stearyl alcohol, emulsifying wax, hydroxyethyl cellulose, xanthan gum, and carbomer; And / or, the stabilizer is selected from sodium stannate or sodium pyrophosphate; And / or, the chelating agent is selected from at least one of disodium EDTA, tetrasodium EDTA, sodium citrate, and sodium gluconate; And / or, the moisturizer is selected from at least one of glycerin, propylene glycol, butylene glycol, panthenol, sorbitol and trehalose; And / or, the surfactant is selected from at least one of cetearyl alcohol polyether-25, PEG-40 hydrogenated castor oil, and alkyl glycosides; And / or, the antioxidant is selected from at least one of ascorbic acid or its derivatives and sodium sulfite; And / or, the penetration enhancer is selected from at least one of azone or its derivatives and propylene glycol; And / or, the conditioning agent is selected from at least one of cationic guar gum, polyquaternium-10, polyquaternium-7, silicone oil, hydrolyzed protein, and phytosterol esters.

8. The method for preparing a hair dye that combines coloring and conditioning according to claim 1, characterized in that, Includes the following steps: Preparation of Agent A: Dissolve the reducing agent in water, add a pH adjuster to adjust to 8.5-9.5 to obtain Agent A; Preparation of Agent B: Dissolve thiol-modified hyaluronic acid in a pH buffer solution of pH 6-7, stir to dissolve and obtain Agent B; Preparation of Agent C: Dissolve the melanin precursor in a pH buffer solution of pH 6-7, stir to dissolve and obtain Agent C; Preparation of Agent D: Mix the oxidizing agent with water evenly, add a pH adjuster to adjust to pH 5-9 to obtain Agent D.

9. A method for preparing a hair dye that combines coloring and conditioning according to claim 6 or 8, characterized in that, Includes the following steps: Preparation of Agent A: The thickener is premixed with water and heated to 60~70℃ to allow it to swell fully. After cooling to below 40℃, the reducing agent, antioxidant, chelating agent and humectant are added. After stirring to dissolve, the pH adjuster is added to adjust to 8.5~9.

5. Agent A is obtained after ultrasonic degassing. Preparation of Agent B: The thickener and pH buffer are premixed and heated to 60-70℃ to allow it to swell fully. After cooling to below 40℃, thiol-modified hyaluronic acid, penetration enhancer, moisturizer and antioxidant are added. After stirring to dissolve, melanin precursor modified keratin peptide is added and stirred evenly. After ultrasonic degassing, Agent B is obtained. Preparation of Agent C: The thickener and pH buffer are premixed and heated to 60-70℃ to allow it to swell fully. After cooling to below 40℃, melanin precursor, plant-derived melanin precursor and surfactant are added. After homogenization, humectant, chelating agent and antioxidant are added. After stirring to dissolve, melanin precursor modified keratin peptide is added and stirred evenly. After ultrasonic degassing, Agent C is obtained. Preparation of Agent D: The thickener is premixed with water and heated to 60~70℃ to allow it to swell fully. After cooling to below 40℃, stabilizers, surfactants and conditioning agents are added. After homogenization, oxidants and pH adjusters are added to adjust the pH to 5~9. Agent D is obtained after ultrasonic degassing.

10. The application of a hair dye that combines coloring and conditioning according to any one of claims 1 to 9, characterized in that, The method of using the hair dye includes the following steps: (1) After washing the hair, apply agent A to the hair at 25~40℃ and let it stand for 10~30 minutes; (2) Apply agent B to the hair at 25~40℃ and let it stand for 5~15 minutes, then rinse the hair with water; (3) Mix agent C and agent D at a mass ratio of 1:1, apply the mixture to the hair and keep it at 25~50℃ for 30~90 minutes; rinse the hair with water, and after drying, the hair dyeing is complete.

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