阅读说明：本技术 一种基于金属-多酚网络结构的循环染发方法 (Cyclic hair dyeing method based on metal-polyphenol network structure ) 是由 崔基炜 耿慧敏 于 2019-12-14 设计创作，主要内容包括：本发明涉及一种基于金属-多酚网络结构的循环染发方法,该方法采用小分子植物多酚在头发内部与金属离子形成金属-多酚网络结构进而显色。本发明的染色方法采用小分子作为原料,可以在不损害头发毛鳞片的情况下,渗透进皮质层并且在头发表面形成较强的粘附显色涂层,更好的保护头发,避免头发再次受损。金属离子与多酚在头发内部发生聚合,大分子的物质不易扩散,染色牢固,具有耐洗涤,遇水及室温条件下不易脱色的优势。(The invention relates to a circulating hair dyeing method based on a metal-polyphenol network structure. The dyeing method adopts micromolecules as raw materials, can permeate into the cortical layer and form a stronger adhesive color-developing coating on the hair surface under the condition of not damaging hair scales, better protects the hair and avoids the hair from being damaged again. The metal ions and the polyphenol are polymerized in the hair, macromolecular substances are not easy to diffuse, the dyeing is firm, and the hair dye has the advantages of washing resistance and difficult decolorization under the conditions of water and room temperature.)

1. A circular hair dyeing method based on a metal-polyphenol network structure comprises the following steps:

adding micromolecular plant polyphenol into a buffer solution for dissolving to obtain a polyphenol buffer solution, adding a metal salt solution into the polyphenol buffer solution, and adjusting the pH value to obtain a hair dye solution; adding the primary white hair into the hair dyeing liquid, stirring, uniformly mixing and standing; taking out, washing with clear water and drying in the air; the polyphenol and metal ions are utilized to form a metal-polyphenol network structure on the hair in situ through the scales, so that the hair is dyed.

2. The method for dyeing hair cyclically according to claim 1, further comprising a decoloring treatment of decoloring the dyed hair with an acid solution, and after the coloring is removed, rinsing the hair with clear water to remove the excess acid solution from the hair to thereby decolor the hair, and further, dyeing the hair for the next time to thereby realize multiple times of dyeing hair cyclically.

3. The method for dyeing hair cyclically according to claim 1, wherein the size of the small-molecule plant polyphenol molecule is less than or equal to 1.4 nm.

4. The method for dyeing hair cyclically according to claim 1, wherein the small-molecule plant polyphenol is any one or a mixture of two or more of pyrogallol, catechol, gallic acid, protocatechuic aldehyde, ethyl gallate, epicatechin, catechin, caffeic acid and o-methyl salicylic acid; preferably, the small-molecule plant polyphenol is gallic acid, protocatechuic aldehyde, pyrogallol and catechol.

5. The loop of claim 1The ring hair dyeing method is characterized in that the polyphenol buffer solution takes polyphenol as solute, and the concentration of the polyphenol is 0.1-100 mg mL^-1(ii) a More preferably, the concentration of the polyphenol is 1-50 mg mL^-1。

6. The method for circularly dyeing hair according to claim 1, wherein the metal salt solution is added in an amount such that the molar ratio of metal ions to polyphenol molecules is 1:1 to 10:1, and more preferably, the metal salt solution is added in an amount such that the molar ratio of metal ions to polyphenol molecules is 3:1 to 7: 1.

7. The method for dyeing hair cyclically according to claim 1, wherein the metal salt of the metal salt solution is any one of ferric ion salt, ferrous ion salt, titanium ammonium salt, copper ion salt, cobalt ion salt and vanadium ion salt; the metal salt solution takes water as a solvent and metal salt as a solute, and the concentration of the metal salt in the metal salt solution is as follows: 1 to 100mgmL^-1Preferably, the concentration of the metal salt in the metal salt solution is 1-50 mg mL^-1(ii) a When black hair dyeing is carried out, the metal salt solution is a ferrous ion salt solution; when the brown hair dyeing is carried out, the metal salt solution is a copper ion salt solution, a cobalt ion salt solution and a ferric ion salt solution; when the green hair dyeing is carried out, the metal salt solution is vanadium ion salt solution.

8. The method for dyeing hair cyclically according to claim 1, wherein the buffer solution is tris-hcl buffer solution, 3-morpholinopropanesulfonic acid-sodium hydroxide buffer solution, disodium hydrogen phosphate-sodium dihydrogen phosphate buffer solution; further preferably, the buffer solution is tris-hydroxymethyl aminomethane-hydrochloric acid buffer solution or 3-morpholinopropanesulfonic acid-sodium hydroxide buffer solution.

9. The method for dyeing hair cyclically according to claim 2, wherein in the step (2), the acid solution for decoloring is any one of hydrochloric acid, oxalic acid, acetic acid or household white vinegar, and the pH value is 0-3.

10. The method for dyeing hair cyclically according to claim 1, wherein in the step (2), the decoloring method is any one of a spraying method, a soaking method and a wiping method, and the treatment time is 1 minute to 1.5 hours.

The technical field is as follows:

the invention relates to a circulating hair dyeing method based on a metal-polyphenol network structure, and belongs to the technical field of cosmetics.

Background art:

with the improvement of living standard of people, hair dyeing not only becomes a main means for covering white hair for the old, but also gradually becomes a trend that young people chase fashion. The hair dye sold on the market at present is mainly an oxidation type hair dye and has the characteristics of wide color spectrum, long dyeing effect and the like. Oxidative hair dyes generally contain two components, one of which is an oxidizing substance such as hydrogen peroxide, ammonia, etc., for opening hair scales; the other component is aromatic amine compound for hair dyeing. The disadvantages of such hair dyes are: the oxidizing substance has strong irritation to skin and seriously damages hair. The aromatic amine compound-p-Phenylenediamine (PDD) is identified as a strong allergen and a suspected carcinogen of animals, and the PDD is forbidden in European Union, and the domestic addition content is not allowed to exceed 5%. Therefore, in view of the health and environmental awareness of consumers, the development of natural plant hair dyes which are non-toxic, efficient and do not damage hair quality becomes a development direction in the field of hair dyeing.

The plant polyphenol is the general term of polyhydroxy phenol compounds, widely exists in plants such as tea leaves, vegetables, fruits and the like, and has good biocompatibility and degradability. A remarkable characteristic of the polyphenol compound is that the polyphenol compound has adhesion to various substrates, and the polyphenol structure not only can form non-covalent bond acting force (such as hydrogen bond, pi-pi accumulation effect and cation-pi effect) with the substrates, but also can form covalent bonds with substrates containing amino or thiol groups through Michael addition or Schiff base reaction to improve the adhesion strength. Another characteristic of polyphenols is that they can coordinate with Metal ions to form Metal-polyphenol networks (MPNs) of different colors to enhance adhesion to substrates. Therefore, the natural plant polyphenol is used in the field of hair dyeing by utilizing self adhesion of the natural plant polyphenol and metal ion chelating coordination, and the defects of the existing hair dye are hopefully overcome.

Chinese patent document CN 109925205 a discloses a multicolor nontoxic hair dye, a preparation method thereof and a hair dyeing method, wherein the hair dye utilizes catecholamine substances to be oxidized by an oxidizing agent to form melanin analogues with strong surface adhesion, and pigments are added to change the surface color of hair. However, strong oxidizing substances such as hydrogen peroxide and sodium periodate are also used. Taiwan patent (certificate No. 040224) discloses the preparation of a two-component hair dye using vanilla tannin and a water soluble iron salt. Chinese patent document CN 102397170 a discloses a method for dyeing hair by coordination of tannic acid or hematoxylin and ferric ions. Both of the above patents belong to two-component hair dyes, one component being a water-soluble iron salt and the other component being a plant polyphenol. And reducing agents such as L-cysteine compounds, mercaptoethanol and the like are added in the formula to break disulfide bonds in the hair protein, so that dye molecules can enter a hair cortex layer for dyeing conveniently. However, the use of the reducing agent can damage and fall off hair scales, so that the hair becomes dry, hairy and lack of moisture; and has the defects of complex operation, difficult storage and the like.

The hair is composed of scales, cortex and medulla, and is a heterogeneous porous medium. The eumelanin and pheomelanin in the cortex determine the apparent color of the hair. The current rapid hair dyeing is undoubtedly the process of opening hair scales and promoting dye molecules to enter the cortex. In 2008, Morel proposed that the size and shape of pores between hair scales can affect the permeability of dye molecules, and the critical molecular size capable of penetrating into hair is measured to be 0.95-1.4 nm. The inventor utilizes tannic acid and water-soluble iron salt to dye and bleach white hair, and can well achieve the purpose of blackening the white hair. However, when the same conditions are used for primary white hair dyeing, the effect is poor; the reason for this is probably that scales of damaged hair are broken and the pore size is enlarged after the bleaching treatment, and the complex of tannic acid and iron ion can penetrate the inside of hair to successfully achieve blackening. While the scales of the original white hair are intact, the molecular size of the tannic acid is 2.4nm, and the tannic acid cannot permeate into the hair to dye.

Therefore, the development of hair dye which can protect the hair quality, is safe, efficient and sustainable in development is still a scientific problem and a technical bottleneck which need to be overcome.

The invention content is as follows:

aiming at the defects of the prior art, the invention provides a circular hair dyeing method based on a metal-polyphenol network structure, which is safe, nontoxic, convenient to use, low in cost, diversified in color, and capable of circularly dyeing and decoloring, and the hair quality is not damaged.

In order to solve the practical problems, the invention is realized by the following technical scheme:

a circular hair dyeing method based on a metal-polyphenol network structure comprises the following steps:

adding micromolecular plant polyphenol into a buffer solution for dissolving to obtain a polyphenol buffer solution, adding a metal salt solution into the polyphenol buffer solution, and adjusting the pH value to obtain a hair dye solution; adding the primary white hair into the hair dyeing liquid, stirring, uniformly mixing and standing; taking out, washing with clear water and drying in the air; the polyphenol and metal ions are utilized to form a metal-polyphenol network structure on the hair in situ through the scales, so that the hair is dyed.

According to the invention, the method also comprises a decolorization treatment, wherein the dyed hair is decolorized by using an acid solution, after color development is eliminated, the hair is washed by using clear water, excessive acid solution on the hair is removed, the decolorization treatment of the hair is realized, and the next dyeing can be carried out, so that multiple times of circular dyeing can be realized.

Preferably, according to the present invention, the hair dye can be used in the form of a solution directly or added into shampoo or added with excipient to form a hair dye cream.

Preferably, according to the invention, the size of the small-molecule plant polyphenol molecule is less than or equal to 1.4nm aiming at the problem that the macromolecular dye cannot permeate hair.

According to the invention, the small molecular plant polyphenol is preferably any one or a mixture of two or more of pyrogallol, catechol, gallic acid, protocatechualdehyde, ethyl gallate, epicatechin, catechin, caffeic acid and o-methyl salicylic acid.

Further preferably, the small-molecule plant polyphenol is gallic acid, protocatechuic aldehyde, pyrogallol and catechol.

According to the preferable polyphenol buffer solution, polyphenol is used as a solute, and the concentration of the polyphenol is 0.1-100 mgmL < -1 >; more preferably, the concentration of the polyphenol is 1-50 mg mL^-1。

According to the invention, preferably, the polyphenol solution, the metal salt solution and the primary white hair can be added at one time or added step by step; the dyeing method is any one of a spraying method, a soaking method and a wiping method, and can also carry out dyeing for many times.

According to the invention, the metal salt solution is preferably added in an amount such that the molar ratio of the metal ions to the polyphenol molecules is 1: 1-10: 1, and more preferably, the metal salt solution is added in an amount such that the molar ratio of the metal ions to the polyphenol molecules is 3: 1-7: 1.

According to the present invention, preferably, the metal salt of the metal salt solution is any one of a ferric ion salt, a ferrous ion salt, a titanium ammonium salt, a copper ion salt, a cobalt ion salt and a vanadium ion salt.

According to the present invention, preferably, the metal salt solution uses water as a solvent, uses a metal salt as a solute, and has a metal salt concentration of: 1 to 100mgmL^-1Preferably, the concentration of the metal salt in the metal salt solution is 1-50 mg mL^-1。

Preferably, according to the present invention, when black dyeing is performed, the metal salt solution is a divalent iron ion salt solution; when the brown hair dyeing is carried out, the metal salt solution is a copper ion salt solution, a cobalt ion salt solution and a ferric ion salt solution; when the green hair dyeing is carried out, the metal salt solution is vanadium ion salt solution.

According to the invention, the buffer solution is preferably tris (hydroxymethyl) aminomethane-hydrochloric acid buffer solution, 3-morpholine propanesulfonic acid-sodium hydroxide buffer solution, disodium hydrogen phosphate-sodium dihydrogen phosphate buffer solution; further preferably, the buffer solution is tris-hydroxymethyl aminomethane-hydrochloric acid buffer solution or 3-morpholinopropanesulfonic acid-sodium hydroxide buffer solution.

According to the present invention, the pH is preferably adjusted to a range of 4 to 10, more preferably 4 to 6.

According to the invention, the acid solution for decolorization is preferably any one of hydrochloric acid, oxalic acid, acetic acid or household white vinegar, and the pH value is 0-3.

According to the present invention, the decoloring method is preferably any one of a spray method, a dipping method and a wiping method, and the treatment time is 1 minute to 1.5 hours.

The invention is based on a metal-polyphenol network structure color development and decoloration mechanism: because the polyphenol is rich in catechol and catechol functional groups and is very easy to generate non-covalent bond or covalent bond acting force with protein in hair, the size of the selected micromolecule plant polyphenol molecule is less than or equal to 1.4nm, and the micromolecule plant polyphenol molecule is micromolecule, can permeate into a cortex layer under the condition of not damaging hair scales, and forms a metal-polyphenol network structure with metal ions in the hair to develop color. The metal-polyphenol network structure is shown as the following formula (I), and the structure formed by coordination is a network structure, has larger molecular weight and is firmly locked in the hair, so the metal-polyphenol network structure is used for dyeing and developing hair firmly, and is not easy to decolor under the conditions of water and room temperature.

But the metal-polyphenol network structure formed by the coordination of the metal ions and the catechol group has higher sensitivity to the pH value of the environment. With the change of pH, the conversion of one coordination, two coordination and three coordination between polyphenol and metal ion can be realized. Because the stronger acidity can inhibit the coordination of metal ions and polyphenol compounds, thereby destroying the metal-polyphenol network structure, the invention can easily realize the decolorization of hair by using an acid solution with the pH value less than 3, and the decolorization is simple and convenient.

The basic formula of the recyclable dyeing hair based on the metal-polyphenol network structure has the following advantages:

1. the invention aims at the dyeing of the original white hair, but not the white hair damaged by decoloration treatment, and has higher use value.

2. The dyeing method does not need to add reducing agents such as hydrogen peroxide, mercaptoethylamine, cysteine and the like, so that the hair scales do not need to be damaged. Is helpful for protecting hair quality and preventing frizziness and injury.

3. The dyeing method of the invention adopts natural plant polyphenol and metal ions contained in human body, takes water as solvent, has safe materials, no other additives, no toxicity and harm, and is environment-friendly.

4. The dyeing method adopts small molecules as raw materials, can permeate into the cortical layer and form a stronger adhesive color-developing coating on the hair surface under the condition of not damaging the hair scales, better protects the hair and avoids the hair from being damaged again.

5. After the method disclosed by the invention is used for dyeing, the metal ions and the polyphenol are polymerized in the hair, macromolecular substances are not easy to diffuse, the dyeing is firm, and the hair dye has the characteristic of washing resistance.

6. The dyeing of the invention can be sprayed, soaked and wiped for dyeing, and shampoo cream can also be added, and the invention has the characteristics of diverse using methods, simple and easy operation and easy preservation.

7. After the hair dyeing and color development, the invention can use the common household oxalic acid, white vinegar and other conventional decolorants to carry out quick decoloration, can easily realize the color erasure after color development, can circularly dye, and better meets the multicolor requirement.

Description of the drawings:

FIG. 1 is a photograph of the polyphenol of examples 1-5 after dyeing hair with different metal ions.

Fig. 2 is the integrated hue difference Δ Ε after dyeing of hair with polyphenols and different metal ions of examples 6-10.

FIG. 3 is a photograph of examples 11-13 after dyeing hair with different ratios of polyphenols and metal ions.

FIG. 4 is the SEM photographs of the primary white hair and the dyed white hair of example 14, wherein a is the primary white hair; b is dyed hair;

FIG. 5 is a photograph of experimental example 1 after 25 and 50 washes of polyphenol and metal ion dyed hair.

Fig. 6 is the integrated hue difference Δ Ε after 25 and 50 washes after dyeing of polyphenols and metal ions of experimental example 1.

FIG. 7 is a photograph showing cyclic dyeing-decoloring of polyphenol with metal ions in Experimental example 2.

FIG. 8 is a tissue section of experimental example 3 after the contact of polyphenol with a metal ion solution on the skin of a mouse for 21 days.

The specific implementation mode is as follows:

for a better understanding of the present invention, reference is made to the following detailed description and accompanying drawings.