LU87270A1 - PROCESS FOR DYEING KERATINIC FIBERS WITH 5,6-DIHYDROXYINDOLE ASSOCIATED WITH A NITRITE AND COMPOSITION FOR USE - Google Patents

Description

Description filed in support of an invention patent application for: "Process for dyeing keratin fibers with 5,6-dihydroxyindole combined with a nitrite and composition for use"

L'OREAL 14, rue Royale 75008 PARIS FRANCE

Process for dyeing keratin fibers with 5.6-dihydroxyindole combined with a nitrite and composition for carrying out the process.

The present invention relates to a new dyeing process using 5.6-dihydroxyindole combined with a nitrite and to the compositions used in this process.

It is well known that the natural biosynthesis of eumelanins from tyrosine takes place in several stages. One of them consists in the formation of 5,6-dihydroxyindole which oxidizes to form a pigment which is one of the main constituents of eumelanin.

Dyeing processes using 5,6-dihydroxyindole and comprising two stages of application have already been proposed in the past. This is how the French patents of the applicant No. 1,133,594, 1,166,172, 2,390,158 and the French patent application 2,536,993 propose methods comprising the application of a metal cation playing the role of promoter. melanogenesis in a separate step from that of 5,6-dihydroxyindole.

French patent application No. 2,594,331 of the applicant uses either manganese in the form of permanganate or a dichromate.

In the case of copper and when it is applied in the first stage, the impregnation of the hair takes place in an alkaline medium, whereas it takes place with permanganate in an acidic or neutral medium. Generally, the hair pretreated with the metal cation is impregnated in a second step with an alkaline or neutral solution of 5.6-dihydroxyindole. The use of metal cations in dyeing processes, however, poses a certain number of problems insofar as the removal of these metal cations from the hair is relatively difficult.

After the two treatments and despite the rinses, there are still traces of metals on the hair which can have drawbacks when the hair has to undergo subsequent treatments such as bleaching or perms. This is more particularly the case for copper and manganese.

The Applicant has also also described, in particular in its French patent application No. 2,593,061, a dyeing process with 5.6-dihydroxyindole using, instead of a metal cation, a mineral anion and more particularly an iodide .

This process is also carried out in two stages. During the first stage, the hair is impregnated with a solution of potassium iodide and 5.6-dihydroxyindole. In the second step, the hair is treated by applying hydrogen peroxide. This last necessary step, which uses hydrogen peroxide, has the well-known drawback of being degrading for the hair and is similar to conventional oxidation dyeing processes.

The Applicant has now surprisingly discovered that it is possible to dye with 5,6-dihydroxyindole without using hydrogen peroxide, ammonia or a metal cation, first impregnating the keratin fibers and in particular the hair with 5,6-dihydroxyindole and secondly, with an acid composition, at least one of the compositions containing a nitrite.

The Applicant has discovered that it is easy to dye natural hair in shades ranging from gray through brown to intense black. The subject of the invention is therefore a new dyeing process using 5,6-dihydroxy-indole and a nitrite.

Another object of the invention consists of compositions or devices with several compartments used in the context of this process. 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 hair, in accordance with the invention, is essentially characterized in that at least one composition (A) is applied to these fibers containing, in a medium suitable for dyeing, at least 5,6-dihydroxyindole, the application of the composition (A) being followed by the application of an acidic aqueous composition (B), the composition (A) or the composition (B) containing at least one nitrite .

The nitrites which can be more particularly used in accordance with the invention are: nitrites of alkali metals, alkaline earth metals or of ammonium or of any other cosmetically acceptable cation when it is used for dyeing living human hair: organic derivatives of nitrites such as for example amyl nitrite; - or nitrite vectors, that is to say compounds which, by transformation, generate a nitrite.

Particularly preferred nitrites are sodium, potassium or ammonium nitrites.

The 5,6-dihydroxyindole is used in the composition (A) in sufficient quantities to dye, after association with the nitrite, the keratin fibers according to the desired shade. This concentration is between 0.01 and 0.3 mole / liter. The nitrite anion expressed in the form of NO2 "is present in sufficient quantities to develop with the 5,6-dihydroxyindole applied in the first step, a coloration. Its concentration is preferably between 0.02 to 1 mole / liter.

The pH of the composition (A) is preferably between 2 and 10.

The pH of the composition (B) is acidic and makes it possible to regulate the coloring.

In an acid medium, the nitrite is sufficiently oxidizing to react with the 5,6-dihydroxyindole according to the following reaction scheme:

The orthoquinone obtained can then, by polymerization, lead to the formation of the pigment.

In an alkaline medium, nitrite is no longer sufficiently oxidizing to oxidize 5,6-dihydroxyindole.

The pH, according to the invention, of composition (B) is therefore between 2 and 6 and preferably is adjusted to around 3 for short contact times and for the darkest shades.

A preferred embodiment of the invention consists in first applying the composition (A) containing 5,6-dihydroxyindole and secondly the composition (B) containing, in aqueous and acidic medium, a nitrite.

Another embodiment of the invention may consist in applying, as a first step, a composition (A1) containing, in a medium suitable for dyeing, 5,6-dihydroxyindole in neutral or alkaline medium and a nitrite. In this case, the hair is dyed by applying, in a second step, a composition comprising an aqueous medium suitable for dyeing, adjusted to an acidic pH and preferably between 2 and 6.

Another object of the invention therefore consists of such a dye composition (A1) simultaneously containing 5,6-dihydroxyindole and nitrite. The proportions of 5,6-dihydroxyindole and of nitrite as well as the nature of the nitrites are those indicated above.

The compositions (A) or (B) as well as the composition (A ′) containing the 5,6-dihydroxyindole and the nitrite may contain adjuvants usually used in dyeing keratin fibers and more particularly in addition to water, a solvent which , in the case where the composition is applied to the hair, is cosmetically acceptable.

The solvents are chosen from organic solvents, such as C1-C5 lower alcohols such as ethyl alcohol, propyl or isopropyl alcohol, tert-butyl alcohol, ethyleneglycol, propylene glycol, monomethyl, monoethyl or monobutyl ethers ethylene glycol, acetate of ethylene glycol monoethyl ether, monomethyl ethers of propylene glycol and dipropylene glycol, methyl lactate.

Particularly preferred solvents are ethyl alcohol and propylene glycol.

The solvents are used more particularly in concentrations of between 10 and 20% for lower alcohols when the concentration of 5,6-dihydroxyindole exceeds 1% by weight relative to the total weight of the composition.

The compositions which can be used in the process according to the invention may also contain anionic, cationic, nonionic, amphoteric surfactants or their mixtures, preferably present in proportions of between 0.1 and 50%, thickening agents, perfumes, sequestering agents, film-forming agents, treatment agents, dispersing agents, conditioning agents, preserving agents, opacifying agents, agents for blowing keratin fibers.

The thickeners can be chosen more particularly from sodium alginate, gum arabic, guar gum, biopolymers such as xanthan gum or scleroglucans, cellulose derivatives such as methylcellulose, hydroxyethyl cellulose, 1 hydroxypropyl methylcellulose, the sodium salt of carboxymethylcellulose and polymers of acrylic acid. It is also possible to use mineral thickening agents such as bentonite.

These thickeners / used alone or as a mixture, are preferably present in proportions of between 0.1 and 5% by weight relative to the total weight of the composition and advantageously between 0.5 and 3% by weight.

The acidifying agents which can be used are more particularly chosen from lactic acid, acetic acid, tartaric acid, phosphoric acid, hydrochloric acid, citric acid.

The basifying agents are more particularly chosen from amines, such as alkanolamines, alkylamines or then alkali or ammonium hydroxides or carbonates.

The compositions (A), (A ') and / or (B) which can be used in the process according to the invention may contain other dyes usually used for dyeing keratin fibers and in particular direct dyes such as nitro derivatives benzene, oxidation dyes such as para or ortho type oxidation dye precursors, couplers or oxidation dyes known as "fast", that is to say molecules with a benzene structure, precursors of dyes, capable of generating the colored compounds by simple oxidation in air, during the exposure time on the hair, generally less than 1 hour and in the absence of another oxidizing agent.

These compositions can be formulated in various, cosmetically acceptable forms, when they are applied to the hair, such as more or less thickened or gelled liquid, creams, emulsions, foams or other forms suitable for producing the dye.

With a view to implementing the process according to the invention, the various compositions can be packaged in a device with several compartments also called a "kit" or dye kit, comprising all the components intended to be applied for the same dye on keratin fibers and in particular the hair, in successive application with or without premix.

Such devices are known in themselves and may comprise a first compartment containing the composition (A) containing the 5,6-dihydroxyindole in a medium suitable for dyeing, in a second compartment, the composition (B) containing in a medium suitable for dyeing an nitrite as defined above at an acid pH.

Another embodiment consists in providing a device with several compartments or "kit" comprising in a first compartment the composition (A1) containing in a medium suitable for dyeing and having a neutral or alkaline pH, 5,6-dihydroxy- indole and a nitrite and in a second compartment, an aqueous solution having an acidic pH preferably between 2 and 6.

The process according to the invention as well as the compositions defined above can be used to dye natural or already dyed hair, permed or not or straightened, or strongly or slightly discolored hair, possibly permed. In this case, the composition (A) is applied at a temperature which is that of the head, that is to say between 25 and 35 ° C., for 5 to 30 minutes and followed, with or without rinsing. intermediate, this application by applying the composition (B) containing the nitrite which is maintained in contact with the hair for 5 to 30 minutes. The dyeing temperature is also that of the head and is between 25 and 35oC.

In the embodiment using 5,6-dihydroxyindole and nitrite in the same composition in neutral or alkaline medium, the first composition (A1) is kept in contact with the hair for 5 to 30 minutes and after any rinsing, the acidic aqueous composition is applied.

It is also possible to use these compositions for dyeing furs or wool.

The following examples are intended to illustrate the invention without, however, being limiting in nature. EXAMPLE 1

A lock of 1 g of gray natural hair containing 90% white is impregnated with a composition (A) below:

Composition- (A) - 5,6-dihydroxyindole 2.5 g - Ethanol 10.0 g - CARBOPOL 940 (crosslinked polyacrylic acid, sold by the company GOODRICH) 2.0 g - Water qs 100.0 g

Spontaneous pH is around 5.5

The composition is kept in contact with the hair for 15 minutes, followed by rinsing with running water and spinning.

The composition (B) is then applied to the wick 5 ml:

Composition (B) - Sodium nitrite 2.5 g - Polyacrylamidomethylpropane sulfonic acid (20% solution of active material) 25 g sold by the company HENKEL under the name COSMEDIA POLYMER HSP 1180 - Hydrochloric acid qs pH = 3 - Water qs 100 0.0g

This composition is maintained in contact with the hair for 10 minutes.

The wick is then rinsed and washed with a shampoo containing 5% sodium lauryl sulfate. We obtain in this way a wick whose color is black chestnut. EXAMPLE 2

A wick of 1 g of hair per 5 ml is impregnated with a composition (A) below:

Composition (A) - 5,6-dihydroxyindole 2.5 g - Ethanol 10.0 g "Water qs 100.0 g

The composition is maintained in contact with the hair for 15 minutes.

Then rinse the wick, wring it out.

The wick is then impregnated with 5 ml of a composition (B):

Composition (B) - Sodium nitrite 0.2 g - Citric acid qs pH = 3 "Water qs 100.0 g

This composition is maintained in contact with the hair for 10 minutes, then rinsed.

Wash with shampoo with a 5% solution of sodium lauryl sulfate. Rinse again and dry.

We get a gray color. EXAMPLE 3

The following composition is prepared: - 5,6-dihydroxyindole 2.5 g - Sodium nitrite 2.5 g - Ethanol 10.0 g - Water qs 100.0 g

Spontaneous pH is 5.5

First, 5 ml of this composition is applied to a lock of 1 g of bleached hair.

The mixture is left in contact for 15 minutes at room temperature, then rinsed with water and the wick is wrung.

In a second step, the wick is impregnated with 5 ml of an aqueous solution of a buffer allowing the pH of the composition to be adjusted to 2 (citric acid / HCl) for 10 minutes.

Rinse, wash the wick with shampoo, rinse again and dry.

We obtain a medium brown color. EXAMPLE 4

10 g of the composition (A) defined in Example 1 are applied to a lock of 1 g of gray hair containing 90% white hairs. This composition is kept in contact with the hair for 15 minutes at room temperature.

Rinse and spin the wick.

This wick is again impregnated with 10 g of the following composition (B):

Composition (B) - Sodium nitrite 2.5 g - Polyacrylamido methyl propane sulfonic acid (20% active ingredient) 25 g - Buffer (acetic acid / sodium acetate) qs pH 4.7 - Water qs 100.0 g

This composition (B) is maintained for 10 minutes in contact with the hair.

Rinse, wash with shampoo, rinse again and dry.

We obtain a medium chestnut color with light purplish reflections. EXAMPLE 5

The following composition is prepared: - 5.6-dihydroxyindole 2.0 g - Ethanol 10.0 g - Hydroxyethyl cellulose sold by UNION CARBIDE under the name CELLOSIZE WP 3 3.0 g - Monoethanolamine qs pH = 8.5 - Water qs 100.0 g

10 g of this composition are applied to a lock of 1 g of natural hair containing 90% white hairs. Leave for 15 minutes, rinse with running water and spin.

Then applied for ten minutes to the wick 10 g of the following composition: - Sodium nitrite 2.0 g - Polyacrylamidomethyl propane sulfonic acid 20% in water 25.0 g - Hcl qs pH = 3 ~ Water qs 100.0 g

Rinse, wash the wick with shampoo, rinse again, then dry.

The wick has a dark chestnut color. EXAMPLE 6

A strand of 1 g of natural hair containing 90% white hairs is impregnated with 10 g of the following composition: - 5.6-dihydroxyindole 2.0 g - Ethanol 10.0 g - CARBOPOL 940 2.0 g - Buffer qs pH = 3 (citric acid / HCl) "Water qs 100.0 g

It is left in contact with the hair for 15 minutes at room temperature. Rinse with running water, then spin.

The wick is again impregnated with the composition containing nitrite and described in Example 5.

Leave for ten minutes, rinse, wash with shampoo, rinse again, then dry the wick.

We get a dark chestnut. EXAMPLE 7

10 g of the composition (A) defined in Example 1 are applied to a lock of 1 g of gray hair containing 90% white hairs. It is left for ten minutes at room temperature.

The gel is removed with a paper or cloth. The wick is again impregnated with 10 g of a composition (B) defined in Example 1. It is left for ten minutes at room temperature. Rinse with water, then wash with shampoo, rinse again and dry.

A black chestnut color is obtained. EXAMPLE 8

10 g of the composition (A) defined in Example 1 are applied to a lock of 1 g of bleached hair. This composition is kept in contact with the hair for fifteen minutes at room temperature. Rinse and spin the wick.

This wick is again impregnated with 10 g of the following composition: - Amyl nitrite 4.5 g - Ethanol 20.0 g - Polyacrylamidomethyl propane sulfonic acid 20% in water 25.0 g - Water qs 100, 0 g

This composition is maintained for ten minutes in contact with the hair. Rinse, wash with shampoo, rinse and dry.

A brown / black coloration is obtained. EXAMPLE 9

10 g of the following composition are applied to a lock of 1 g of natural hair containing 90% permanent whites: - 5,6-dihydroxyindole 2.0 g - Ethanol 10.0 g - CARBOPOL 940 2.0 g - Water qs 100.0 g

The spontaneous pH is around 5.5.

It is left in contact with the hair for 15 minutes at room temperature. We wash and spin the wick.

10 g of composition (B) from Example 1 are then applied to this same lock.

It is left for 10 minutes at room temperature, rinsed, washed with shampoo, rinsed again and the wick is dried.

A black chestnut color is obtained. EXAMPLE 10

Apply to a lock of 1 g of bleached hair, 10 g of the following composition: - 5.6-dihydroxyindole 1.0 g - Ethanol 10.0 g - CELLOSIZE WP 3 (hydroxyethyl cellulose) 2.5 g - pH buffer = 10 10.0 g - Water qs 100.0 g

Leave for 15 minutes, rinse and wring out the wick.

The wick is again impregnated with 10 g of the following composition: - Sodium nitrite 1.5 g - Polyacrylamidomethyl propane sulfonic acid 20% in water 25.0 g - HCl qs pH = 3 - Water qs 100.0 g

This composition is left for 10 minutes in contact with the hair. Rinse, wash with shampoo, rinse again and dry.

A black coloration is obtained. EXAMPLE 11

10 g of the following composition are applied to a lock of 1 g of natural hair containing 90% white hairs: - 5,6-dihydroxyindole 1.0 g - Paraphenylene diamine 1.0 g - Ethanol 20.0 g - Carbopol 940 2 0.0 g - Water qs 100.0 g

This composition is left for fifteen minutes in contact with the hair. Rinse and then wring out the wick.

10 g of the following composition are then applied to the lock: - Sodium nitrite 2.0 g - Polyacrylamidomethyl propane sulfonic acid 20% in water 25.0 g - HCl qs pH: 3 - Water qs 100.0 g

Leave for ten minutes, rinse, wash with shampoo, rinse again and dry.

We get a medium brown. EXAMPLE 12

10 g of the following composition are applied to a lock of 1 g of natural hair containing 90% white hairs - 5,6-dihydroxyindole 2.0 g - Paraphenylene diamine 1.0 g - Resorcin 1.0 g - Ethanol 20.0 g - CARBOPOL 940 2.0 g - Water qs 100.0 g spontaneous pH of around 6.

The wick is then rinsed with running water, wrung out and again impregnated with 10 g of the composition (B) described in Example 1.

It is left in contact for 10 minutes, rinsed with water, then washed with shampoo, rinsed again and dried.

We get a dark brown wick. EXAMPLE 13

A lock of 1 g of natural hair containing 90% white hairs is impregnated for 15 minutes with the following composition: - 5,6-dihydroxyindole 1.0 g - 1-N, N '- (ß-dihydroxyethyl) amino 3-nitro 4- (ß-hydroxyethyl) amino benzene 0.5 g - Ethanol 20.0 g - CELLOSIZE WP 3 4.0 g - Monoethanolamine qs pH = 9 - Water qs 100.0 g

After 15 minutes of contact, wash, then spin the wick. The wick is again impregnated for 10 minutes with the following composition: - Sodium nitrite 2.0 g - Polyacrylamidomethyl propane sulfonic acid (20% solution in water) 25.0 g - HCl qs pH = 3 - Water qs 100.0 g

After contact, the wick is washed with running water, a 5% sodium lauryl sulphate shampoo is carried out, rinsed again and dried.

A wick is obtained, the coloring of which is golden brown. EXAMPLE 14

Apply for fifteen minutes to a lock of 1 g of natural hair containing 90% white hair, the following composition: - 5,6-dihydroxyindole 4.5 g - Ethanol 20.0 g - Carbopol 940 2.0 g - Water qs 100, 0 g

After the fifteen minutes of exposure time, rinse the wick under running water and then wring it out. impregnate this wick again for ten minutes with the following composition: - Sodium nitrite 0.15 g - Polyacrylamidomethyl propane sulfonic acid 20% in water 25.0 g - HCl qs pH: 3 - Water qs 100.0 g

After ten minutes of contact, rinse the wick under running water, shampoo with sodium lauryl sulfate at 5%, rinse again and dry.

We obtain a wick whose color is dark gray.

Claims (17)

1. Process for dyeing keratin fibers, characterized in that at least one composition (A) is applied to these fibers (A) containing, in a medium suitable for dyeing at least 5.6-dihydroxyindole, the application of the composition ( A) being followed by the application of a composition (B) consisting of an aqueous composition having an acidic pH, the composition (A) or (B) containing at least one nitrite. 2. Dyeing method according to claim 1, characterized in that the nitrite is chosen from nitrites of alkali metals, alkaline earth metals or of ammonium or of another cosmetically acceptable cation, as well as organic derivatives of nitrites or nitrite vectors generating by transformation a nitrite. 3. Method according to claim 1 or 2, characterized in that the nitrite is chosen from sodium, potassium or ammonium nitrites. 4. Method according to any one of claims 1 to 3, characterized in that 5.6-dihydroxyindole is used in concentrations between 0.01 and 0.3 mole / liter. 5. Method according to any one of claims 1 to 3, characterized in that the nitrite is used in proportions of between 0.02 and 1 mole / liter. 6. Method according to any one of claims 1 to 5, characterized in that the pH of the composition (A) is between 2 and 10. 7. Method according to any one of claims 1 to 5, characterized in that the pH of the composition (B) is between 2 and 6. 8. Method according to any one of claims 1 to 7, characterized in that the composition (A) or (B) contains in addition to water at least one or more organic solvent (s) cosmetically acceptable (s). 9. Method according to any one of claims 1 to 8, characterized in that composition A, A 'or B additionally contains a direct dye, an oxidation dye, a coupler or a fast oxidation dye. 10. A process for dyeing keratin fibers according to any one of claims 1 to 9, characterized in that a composition (A) is first applied, in a medium suitable for dyeing, 5, 6-dihydroxy-indole and in a second step a composition (B) containing, in an aqueous medium adjusted to an acidic pH, a nitrite. 11. Method according to any one of claims 1 to 8, characterized in that a composition (A1) is first applied, in a medium suitable for dyeing and having a neutral or alkaline pH, of 5,6-dihydroxy-indole and a nitrite, and in a second step, an aqueous composition is applied adjusted to an acidic pH. 12. Method according to any one of claims 1 to 11, characterized in that the first step is followed by a rinsing step. 13. Method according to any one of claims 1 to 12, characterized in that the composition applied in the first time is maintained in contact with the hair for a period of 5 to 30 minutes and that the composition applied in the second time is maintained in contact with the hair for a period also of 5 to 30 minutes. 14. Application of the method as defined in any one of claims 1 to 13, to the dyeing of human hair. 15. Composition intended to be used for dyeing keratin fibers and in particular human hair, characterized in that it contains in an aqueous medium at neutral or alkaline pH, suitable for dyeing, at least 5,6- dihydroxyindole and at least one nitrite. 16. Multi-compartment device or "kit" intended for use in the dyeing of keratin fibers and in particular human hair, characterized in that it comprises in a first compartment a composition (A) containing in a medium suitable for dyeing 5,6-dihydroxyindole and in a compartment (B) an aqueous composition having an acidic pH containing a nitrite. 17. Multi-compartment device or "kit" intended for use in the dyeing of keratin fibers and in particular human hair, characterized in that it comprises in a first compartment a composition (A ') as defined in claim 14 and in a second compartment an acidic aqueous composition.