CH672729A5 - - Google Patents

Description

DESCRIPTION

The dyeing of human keratin fibers, and in particular human hair, using 5,6-dihydroxyindole, is well known and has been the subject of various French patents of the holder Nos 1133 594, 1 166 172, 2390 158 and French patent application 2536993.

Among the hair dyeing processes described in these various documents, it has been mentioned the possibility of using, as oxidation catalyst, different metal salts such as manganese, cobalt, iron, copper salts , silver. The latest patent application recommends the use of cupric ions in alkaline solution, but also of metal ions such as those of iron, cobalt, manganese, silver, titanium, zirconium, tantalum, chromium,

nickel, palladium, platinum, gold, mercury, cadmium, zinc, tin, antimony, lead and bismuth.

These different processes use metal cations used as "melanogenesis promoters" or "oxidation catalysts".

The use of potassium permanganate or sodium dichromate has already been recommended in hair dyeing, but under conditions such that these derivatives could only react in the hair in their reduced form, ie ie metal cations.

The licensee discovered, which is the subject of the invention, that it was possible to significantly improve the dyeing power of 5,6-dihydroxyindole or certain of its derivatives by pretreating the keratin fibers with an anion metal having a good affinity for keratin and having a redox potential greater than that of 5,6-dihydroxyindole or its derivatives.

The advantages of this pretreatment are manifested in particular during repeated dyeing treatments or for the dyeing of keratin fibers such as the hair such as "unnatural" hair, that is to say already sensitized by a cosmetic treatment such as the discoloration or perm.

Without this explanation being limiting, the licensee believes that the anion, once fixed on the fiber, acts as an oxidant vis-à-vis 5,6-dihydroxyindole or its derivatives.

5

10

15

20

25

30

35

40

45

50

55

60

65

3

672,729

The subject of the invention is therefore a process for dyeing keratin fibers, in particular human hair, using a pretreatment with a metal anion having a good affinity for keratin, this pretreatment being followed by the application of 5.6 -dihydroxyindole or some of its derivatives.

Another object of the invention is constituted by a device with several compartments, or dyeing kit, allowing the implementation of the method according to the invention.

Other objects of the invention will appear on reading the description and the examples which follow.

The process for dyeing keratin fibers, and in particular human hair, in accordance with the invention is essentially characterized by the fact that successively:

a) a composition containing, in a medium suitable for dyeing, at a pH between 2 and 10, an anion of a metal having an affinity for keratin and having an oxidoreduction potential greater than that of 5, 6-dihydroxyindole or its derivatives of formula I:

in which R, and R2, independently of one another, denote hydrogen, methyl or ethyl,

b) a composition containing, in a medium suitable for dyeing, at a pH of between 7 and 10, a dye of formula I.

For example, the redox potential, extrapolated to pH 0, of the 5,6-dihydroxyindole being +0.25 volt / H2, the anions used in accordance with the invention must therefore have a higher redox potential, under these conditions, to that of the dye.

The method is preferably applied to dyeing hair and in particular living human hair. The medium suitable for the dye is in this case cosmetically acceptable.

The preferred dyes of formula I are 5,6-dihydroxyindole, 2-methyl 5,6-dihydroxyindole, 3-methyl 5,6-dihydroxyindole and 2,3-dimethyl 5,6-dihydroxyindole.

The particularly preferred anions consist of the permanganate (MnO 4 T) and bichromate (Cr 2 072 ~) anions and deriving more particularly from potassium permanganate and sodium bichromate.

The composition containing the metal anions preferably has an anion molality greater than 10 ~ 3 mole / 1000 g, and preferably situated between 10 ~ 2 mole / 1000 g and 10- 'mole / 1000 g. This corresponds, for Mn04 ", to a concentration greater than 0.012 g% and preferably comprised between 0.12 and 1.18 g% and, for Cr2072-, to a concentration greater than 0.022 g% and preferably comprised between 0, 22 and 2.16 g%.

The pH of the composition containing the anion is adjusted with acidifying or basifying agents having no reducing effect on the anions.

In a particularly preferred embodiment, the composition used for the pretreatment is acidic and has a pH preferably between 2 and 5 and in particular close to 3. An inorganic acid which can be used can for example be sulfuric acid.

The pretreatment composition may also contain other inorganic adjuvants. By way of example, mention may be made of silicas or clays, making it possible in particular to thicken or swell this composition. It does not contain adjuvants that can reduce the anion.

This composition preferably has a viscosity sufficient for application to the head.

The composition containing 5,6-dihydroxyindole or a derivative of formula I is preferably adjusted to a pH of between 7 and 10 using an alkalizing agent, inorganic or organic, known in itself. For this purpose, there may be mentioned as basifying agents ammonia or amines such as monoethanolamine, diethanolamine, triethanolamine, morpholine, diethylamine, hy-droxylamine.

The concentration of 5,6-dihydroxyindole or its derivatives, of formula I, can vary between 0.5 and 2% by weight, and preferably between 1 and 1.5% by weight relative to the total weight of the composition used. implemented in the second stage of the process.

This composition can contain, in addition to water, various solvents among which mention may be made of lower Cx-C4 alkanols such as ethanol, isopropanol, propanol, tert-butyl alcohol, ethylene glycol, monomethyl ethers , monoethyl or monobutyl of ethylene glycol and ethylene glycol monoethyl ether acetate, propylene glycol, monomethyl ethers of propylene glycol or dipropylene glycol and methyl lactate. The solvents are used in proportions preferably between 1 and 30% by weight, and more particularly between 3 and 20%.

This composition can also contain other adjuvants such as surfactants, electrolytes, antioxidants, buffers, perfumes, fatty amides, keratinous fiber swelling agents such as urea, sequestrants, film-forming agents, preservatives, etc. These compositions can also be thickened, in particular with agents chosen from sodium alginate, gum arabic, guar gum, biopolymers such as xanthan gum or scleroglu-canes, cellulose derivatives such as methylcellulose, hydroxyethylcellulose, hydroxypropylmethylcellulose, carboxymethylcellulose and various polymers having thickening functions such as derivatives of acrylic acid. These compositions can also be thickened with mineral thickening agents such as bentonite. The thickening agents are preferably present in proportions of between 0.1 and 5% by weight, and in particular of between 0.5 and 3% by weight relative to the total weight of the composition.

An embodiment of the invention may also consist in storing the dye in an anhydrous medium as described in French patent No. 2,390,158 of the holder and in mixing, just before use, this composition with an aqueous medium suitable for the dye. The anhydrous medium can consist of the solvents defined above containing less than 1% of water.

The process according to the invention consists essentially in applying, firstly and for a period of 3 to 30 minutes, preferably from 5 to 20 minutes, the composition containing the anion defined above, at room temperature of around 25 to 35 ° C. It is possible, if necessary, to accelerate the treatment by a slight heating to about 40 ° C.

The fibers are rinsed. After this treatment, the dye composition is applied for a period of 2 to 10 minutes, rinsing with water and optionally shampooing and rinsing again.

This process can be used to dye natural or already dyed hair, permed or not, or straightened, or strongly or slightly discolored and possibly permed hair.

It is also possible to use it to dye furs.

Another object of the invention is constituted by a device with several compartments, or kit, for dyeing, comprising in a single presentation a plurality of containers, one of which contains the coloring composition, the other the anion, and optionally a third containing the aqueous medium when the dye is stored in anhydrous form.

The pretreatment composition can be packaged in two parts, one containing the anion in the form of an aqueous solution, the other containing a thickened aqueous solution. It is understood that these different compartments are intended to be mixed just before use.

When the dyeing process according to the invention applies to hair dyeing, it can optionally still be

5

10

15

20

25

30

35

40

45

50

55

60

65

672,729

4

preceded or followed by other cosmetic treatments known in themselves.

The following examples are intended to illustrate the invention without, however, being limiting in nature.

Example 1

A stock solution of stable potassium permanganate is prepared by dissolving 1.58 g of KMnO4 in 100 ml of water (final volume) adjusted to pH 3 with H2SO4. This solution is kept in a bottle protected from light.

Into a gel prepared by mixing 7 g of silica, Aerosil 200 (Degussa), with 85 g of water brought to pH 3 with H2SO4, 9 g of the mother solution of potassium permanganate are intimately incorporated, with stirring.

The hair is covered with the gel thus prepared using a spatula or a brush.

The pose lasts 10 minutes.

The hair is rinsed with water to remove the gel.

Before use, a thickened solution containing:

- NH4C1 5.0 g

- Cellosize WP03H 5.0 g

- NH4OH q.s. pH 9.0

- Water q.s. 80g

1 g of 5,6-dihydroxyindole, dissolved beforehand in 20 g of anhydrous ethanol, is incorporated just before use and very quickly.

The pretreated hair is covered with this solution.

The pose lasts 5 minutes.

The hair is abundantly rinsed with water. A sodium lauryl sulfate shampoo is applied to the head.

The initially gray hair, 90% white, has become black.

Example 2

The pretreatment is identical to that of Example 1.

Before use, a thickened solution is prepared containing:

- Dipotassium hydrogen phosphate 5.6 g

- Potassium dihydrogen phosphate 2.2 g

- Cellosize WP03H 5.0 g

- HCl or NaOH q.s. pH 7.0

- Water q.s. 80g

1 g of 5,6-dihydroxyindole, dissolved beforehand in 20 g of anhydrous ethanol, is incorporated just before use and very quickly.

The pretreated and rinsed hair is covered with this solution. The pose lasts 5 minutes.

The hair is abundantly rinsed with water. A sodium lauryl sulfate shampoo is applied to the head.

The initially gray hair, 90% white, has taken on a very intense gray hue.

Example 3

The mother solution of potassium permanganate is that described in Example 1.

A gel is prepared by kneading 7 g of silica, Aerosil 200 (Degussa), with 76 g of water brought to pH 3 with H2SO4; 18 g of the potassium permanganate stock solution are incorporated intimately with stirring.

The hair is covered with gel and the installation lasts 5 minutes. The hair is rinsed with water.

The same dye composition and the same process as those described in Example 1 are used to dye this hair.

The initially gray hair, 90% white, has become black.

Example 4

The mother solution of potassium permanganate is that described in Example 1.

A thickened solution is prepared by mixing 15 g of Gel White H / USP clay with 70 g of water. The pH is adjusted to 3 with a minimum of sulfuric acid. 11.5 g of potassium permanganate stock solution are then incorporated.

The final weight is adjusted to 100 g with a little water at pH 3 (H2SO4).

The hair is covered with this thickened solution.

The pose lasts 5 minutes.

The hair is rinsed with water.

Before use, a thickened solution is prepared containing:

- NH4C1 5.0 g

- Carbopol 940 0.7 g

- NH4OH q.s. pH 9.0

- Water q.s. 80g

1.2 g of 5,6-dihydroxyindole, previously dissolved in 20 g of ethanol, are incorporated just before use and very quickly.

The pretreated hair is covered with this solution.

The pose lasts 5 minutes.

The hair is abundantly rinsed with water. A sodium lauryl sulfate shampoo is applied to the head.

The initially gray hair, 90% white, has become black.

Example 5

A solution of potassium dichromate is prepared by dissolving 2.94 g of K2Cr207 in 100 ml of water (final volume), adjusted to pH 3 with H2SO4. This solution is kept in a bottle protected from light.

A thickened solution is prepared by mixing 15 g of Gel White H / USP clay with 50 g of water. The pH is adjusted to 3 with sulfuric acid. 30 g of potassium dichromate stock solution are then incorporated.

The final weight is adjusted to 100 g with a little water at pH 3 with H2SO4.

The hair is covered with this thickened solution.

The pose lasts 10 minutes.

The hair is rinsed with water.

A thickened solution of 5,6-dihydroxyindole is prepared before use, as in Example 4.

The pretreated hair is covered with this solution.

The pose lasts 5 minutes.

The hair is abundantly rinsed with water. A sodium lauryl sulfate shampoo is applied.

The initially gray hair, 90% white, has become black.

Example 6

A permanganate gel is prepared as described in Example 1.

A lock of bleached hair is treated with the above-mentioned gel for 10 minutes at room temperature, then the hair is rinsed with water to remove the gel.

1.2 g of 5,6-dihydroxyindole are incorporated, just before use, in a thickened solution containing:

- Glycoside alkyl ether (Triton CG 110) 5.0 g

- Guar gum (Jaguar HP 60) 1.0 g

- Ammonium chloride 5.0 g

- Ammonia q.s.p. pH 9

- Water q.s.p. 80g

This thickened solution is applied to this lock for 10 minutes, rinsed with water, washed and dried. The hair is dyed in raven black.

Example 7

The same solutions are prepared as in Example 6, but by replacing the 5,6-dihydroxyindole:

- either with 1.3 g of 2-methyl 5,6-dihydroxyindole,

- either with 1.4 g of 2,3-dimethyl 5,6-dihydroxyindole,

5

10

15

20

25

30

35

40

45

50

55

60

65

5

672,729

- either with 1.2 g of 3-methyl 5,6-dihydroxyindole,

and also replacing the lock of bleached hair with a lock of 90% natural gray hair.

The following colors are obtained respectively:

- dark gray-brown,

- dark gray-green,

- dark gray-blue.

Example 8

Example 1 is repeated and the natural hair is replaced by 5 permed hair and an intense black coloring is obtained.

R

Claims (16)

672,729 CLAIMS 1. Process for dyeing keratin fibers, characterized in that the following are applied successively to these fibers: a) a composition containing, in a medium suitable for dyeing, at a pH between 2 and 10, an anion of a metal having a good affinity for keratin and having an oxidoreduction potential greater than that of 5 , 6-dihydroxyindole or its derivatives, of formula I: HOHO in which R, and R2, independently of one another, denote hydrogen, methyl or ethyl, b) a composition containing, in a medium suitable for dyeing, at a pH of between 7 and 10, a dye of formula I. 2. Method according to claim 1, characterized in that the dyes are chosen from 5,6-dihydroxyindole, 2-methyl 5,6-dihydroxyindole, 3-methyl 5,6-dihydroxyindole, 2,3- dimethyl 5,6-dihydroxyindole. 3. Method according to claim 1 or 2, characterized in that the pennant is a permanganate or a dichromate. 4. Method according to claim 3, characterized in that one uses potassium permanganate or sodium dichromate. 5. Method according to one of claims 1 to 4, characterized in that the anion is present at a molality greater than 10-3 mole / 1000 g and preferably comprises between 10 ~ 2 mole / 1000 g and 10 " 1 mole / 1000 g. 6. Method according to one of claims 1 to 5, characterized in that the pH of the composition containing the anion is acidic and preferably between 2 and 5, and that it is adjusted with inorganic acids. 7. Method according to one of claims 1 to 6, characterized in that the composition containing the anion is in the form of an aqueous composition containing inorganic adjuvants capable of giving it a viscosity allowing application to the head. 8. Method according to one of claims 1 to 7, characterized in that the compounds of formula I are present in proportions of between 0.5 and 2% and preferably between 1 and 1.5% by weight relative to the total weight of the composition used in the second step. 9. Method according to one of claims 1 to 8, characterized in that the composition containing the dye is aqueous and additionally contains a solvent chosen from lower alkanols in QQ, ethylene glycol, monomethyl, monoethyl and mo ethers -nobutyl ethylene glycol or ethylene glycol monoethyl ether acetate, propylene glycol, monomethyl ethers of propylene glycol or dipropylene glycol and methyl lactate. 10. Method according to one of claims 1 to 9, characterized in that the composition containing the dyes of formula I also contains adjuvants chosen from antioxidants, buffers, perfumes, surfactants, fatty amides, fiber blowing agents, sequestrants, preservatives, film-forming agents and thickeners. 11. Method according to one of claims 1 to 10, characterized in that an anhydrous solution of 5,6-di-hydroxyindole or its derivatives of formula I is prepared beforehand in an organic solvent and that, at at the time of application, an aqueous medium suitable for dyeing is mixed with said solution. 12. Method according to one of claims 1 to 11, characterized in that the composition applied at first is kept in contact with the fibers for a period of 3 to 30 minutes, that its application is followed by rinsing at water and that the composition applied in the second step is kept in contact with the fibers for a period of 2 to 10 minutes, application followed by rinsing with water and optionally washing and rinsing again. 13. Device with several compartments or kit for dyeing keratin fibers, for implementing the method according to claim 1, characterized in that one of the compartments comprises at least one composition containing, in a medium suitable for dyeing , the anion as defined in one of claims 1, 3 and 4, that the other compartment contains the composition containing 5,6-dihydroxyindole or its derivatives of formula I, as defined in one of claims 1, 2 and 8 to 12, compositions intended to be applied successively to keratin fibers. 14. Device with several compartments according to claim 13, characterized in that one of the compartments contains the composition containing, in a medium suitable for dyeing, the anion as defined in one of claims 1, 3 and 4, that the other compartment contains 5,6-dihydroxyindole or its derivatives, of formula I, in an anhydrous solvent medium, and that the third compartment contains an aqueous medium, the contents of the second and of the third being intended to be mixed just before the 'employment. 15. Device with several compartments according to claim 13 or 14, characterized in that one of the compartments contains the solution of the anion as defined in one of claims 1, 3 and 4, that the other compartment contains a thickened aqueous solution, that the third compartment contains 5,6-dihydroxyindole or its derivatives in an anhydrous solvent medium, and that the fourth compartment contains an aqueous medium, the contents of the first two compartments and the contents of the last two compartments being intended to be mixed just before use. 16. Application of the method according to one of claims 1 to 12 to dyeing human hair.