GB2187210A

GB2187210A - Process for dyeing keratinous fibres with 5,6-dihydroxyindole or its derivatives and a metal-containing anion

Info

Publication number: GB2187210A
Application number: GB08703842A
Authority: GB
Inventors: Jean Claude Arnaud; Pierre Bore
Original assignee: LOreal SA
Current assignee: LOreal SA
Priority date: 1986-02-20
Filing date: 1987-02-19
Publication date: 1987-09-03
Anticipated expiration: 2007-02-19
Also published as: IT1207356B; BE1000115A3; ES2003225A6; FR2594331B1; IT8767119A0; FR2594331A1; GB2187210B; LU86314A1; CH672729A5; GB8703842D0; DE3705453A1; CA1298042C; JPS62246510A

Abstract

A process for dyeing keratinous fibres wherein a composition (a) having a pH from 2 to 10 comprising, in a medium suitable for dyeing, a metal-containing anion (e.g. MnO4<-> or Cr2O7<2->) exhibiting good affinity for keratin and having a redox potential higher than that of a compound of formula (I) defined below; and a composition (b) having a pH of from 7 to 10 comprising, in a medium suitable for dyeing, a compound of formula (I> <IMAGE> in which R1 and R2, independently of each other, are hydrogen, methyl or ethyl are sequentially applied to the fibres.

Description

SPECIFICATION Process for dyeing keratinous fibres with 5,6-dihydroxyindole or its derivatives and a metal anion The present invention relates to a process for dyeing keratinous fibres, especially human hair, using compositions containing 5,6-dihydroxyindole or its derivatives and metal anions as well as to kits containing such anions.

The dyeing of human keratinousfibres, in particular human hair, using 5,6-dihydroxyindole is well known from French Patent Nos.1,133,594, 1,166,172 and 2,390,158 and from French PatentApplication Publication No.2,536,993.

Processes for dyeing hair which are described in these documents include the use, as an oxidation catalyst, of metal salts such as manganese, cobalt, iron, copper and silver salts. FR-A-2,536,933 describes the use of cuprous ions in an alkaline solution, and also metal ions such as iron, cobalt, manganese, silver, titanium, zirconium, tantalum, chromium, nickel, palladium, platinum, gold, mercury, cadmium, zinc, tin, antimony, lead or bismuth ions.

These processes make use of metal cations as "melanogenesis promoters" or "oxidation catalysts".

The use of potassium permanganate or sodium dichromate in hair dyeing has already been recommended, but only under conditions such that they react witch hair in their reduced form,that is to say in the form of metal cations.

We have surprisinglyfound that it is possibleto improve considerablythe dyeing powerof 5,6-dihydroxyindole or some of its derivatives by pretreating keratinousfibreswith a metal containing anion having good affinity for keratin and having a redox potential higherthan that of 5,6-dihydroxyindole orofits derivatives.

The advantages ofthis pretreatment can especially be seen when repeated dyeing treatments are carried out on keratinous fibres such as untreated hair or "unnatural" hair, that is to say, hair already sensitized by a cosmetic treatment such as bleaching or permanent-waving.

Without any limitation being implied by this explanation, it is presently thought that, once attached to the fibres, the anion could act as an oxidizing agenttowards 5,6-dihydroxyindole or certain of its derivatives.

The subject of the invention is consequently a process for dyeing keratinous fibres, in particular human hair, which employs a pretreatment with a metal anion having good affinity for keratin, this pretreatment being followed by the application of 5,6-dihydroxyindole or some of its derivatives.

Another subject of the invention is a device with a number of compartments, or a dyeing "kit", which enables the process according to the invention to be putto use.

Accordingly the present invention provides a process for dyeing keratinous fibres wherein a composition (a) having a pH of from 2 to 10 comprising, in a medium suitable dor dyeing, a metal containing anion exhibiting good affinityforkeratin and having a redoxpotential higherthanthatofa compound offormula (I) defined below; and a composition (b) having a pH offrom 7to 10 comprising, in a medium suitablefordyeing, a compound of formula (I).

in which R1 and R2 independently of each other are hydrogen, methyl or ethyl; are sequentially applied to the fibres.

By way of example, since the redox potential of 5,6-dihydroxyindole, extrapolated to pH 0, is +0.25 volts/H2, the anions used according to the invention need to have a higher redox potential than that ofthe dye offormula (I) under these conditions.

The process is preferably applied to hair, in particularto living human hair. In this case the medium suitable for dyeing is a cosmetically acceptable medium.

The preferred compounds offormula I are 5,6-dihydroxyindole, 2-methyl-5,6-dihydroxyindole, 3-methyl-5,6-dihydroxyindole and 2,3-di methyl-5,6-dihydroxyindole.

The anions which are particularly preferred are permanganate (MnOj) and dichromate (cur2072~) anions.

These anions are preferably derived from potassium permanganate and sodium dichromate.

Composition (a) preferably has molality of said anion higher than 10-3 mole/1000 g, more preferablyfrom 10-2 mole/1000 g to 10-1 mole/1000 g. In the case of MnOdthis corresponds to a concentration higherthan 0.012 g % and preferably from 0.12 to 1.18 g %, and in the case of Cur2072~, a concentration higher than 0.022 g %, and preferably from 0.22 to 2.16 g %.

Composition (a) has a pH of from 2 to 10. The pH may be adjusted with an acidifying or alkalifying agent which preferably has no reducing effect on the anions.

In a particularly preferred embodiment, composition (a) is acidic, preferably having a pH of from 2 to 5, most preferably approximately 3. An inorganic acid such as sulphuric acid can be employed as acidifying agent.

Composition (a) may also comprise other inorganic adjuvants, such as silicas or clays to thicken our expand the composition. The latter contains no adjuvants which are capable of reducing the anion.

Composition (a) preferably has sufficient viscosity for application to the human head.

Composition (b) has a pH offrom 7 to 10. The pH can be adjusted with a known inorganic or organic alkalifying agent such as aqueous ammonia or an amine such as monoethanolamine, diethanolamine, triethanolamine, morpholine, diethylamine or hydroxylamine.

The concentration of the compound offormula (I) is generallyfrom 0.5 to 2% by weight, preferably from 1 to 1.5% by weight, relative to the total weight of composition (b).

In addition to water, composition (b) may contain solvents, for example C1C4 aikanols such as ethanol, isopropanol, propanol,tert-butyl alcohol, ethylene glycol and ethylene glycol monomethyl, monoethyl or monobutyl ethers and ethylene glycol monoethyl ether acetate, propylene glycol, the monomethyl ethers of propylene glycol or of dipropylene glycol and methyl lactate. The solvents are generally used in a proportion offrom 1 to 30% by weight, more particularly from 3 to 20%, relative to the total weight of the composition.

Composition (b) may also contain other adjuvants such as surface-active agents, electrolytes, antioxidants, buffers, perfumes, fatty amides, agents for swelling the keratinous fibres such as urea, sequestrants, film-forming agents or preservatives. These compositions may also be thickened, especially using agents such as sodium alginate, gum arabic, guargum, biopolymerssuch asxanthane gum orscleroglucans, cellulose derivatives such as methylcellulose, hydroxyethylcellulose, hydroxypropylmethylcellulose, carboxymethylcellulose, or polymers functioning as thickeners such as acrylic acid derivatives our mineral thickening agents such as benton ite. The thickening agents are preferably present in a proportion of from 0.1 to 5% by weight, and in particular from 0.5 to 3% by weight, relative to the total weight ofthecomposition.

The adjuvants are preferably cosmetically acceptable.

The present invention also provides a device with several compartments or a two- or more component pack, wherein at least one of the compartments contains or components comprises, in a medium suitable for dyeing, an anion as defined above and at least one of the compartments contains or components comprises a compound offormula (I) as defined above.

The dye may be stored in an anhydrous medium, as, for example, described in French Patent No.2,390,158 and this composition may be mixed just before use with an aqueous medium suitable for dyeing. The anhydrous medium may, for example, comprise at least one of the solvents defined above but contain less than 1%water.

Thus the present invention also provides a device with several compartments or a two- or more component pack, wherein at least one of the compartments contains or components comprises, in a medium suitable for dyeing, an anion as defined above, at least one other compartment contains or component comprises a compound of formula (I) as defined above in an anhydroussolvent medium and at least one additional compartment contains or component comprises an aqueous medium. The contents of the second and third compartments or components are intended to be mixed just before use. The pack or device may be provided with an additional compartment or component which contains or comprises a thickened aqueous solution intended to be mixed with composition (a) just before use.

The process according to the present invention preferably comprises in applying, in a first step, a composition (a) as defined above to the fibres for from 3to 30 minutes, preferably from 5to 20 minutes, generally at an ambient temperature of the order offrom 25 to 35"C. If desired, the treatment may be accelerated by gentle heating to about40 C.

The fibres are then rinsed. Afterthis treatment, composition (b) is applied, preferablyforfrom 2 to 10 minutes, and this is followed by rinsing with water and, if desired, shampooing and rinsing again.

This process can be used for dyeing natural or already dyed hair, which may be permanently-waved or uncurled and/orstrongly or lightly bleached. It can equally be used for dyeing fur orwool.

When the dyeing process according to the present invention is carried out on hair it may, if desired, be preceded or followed by other known cosmetictreatments.

The following Examples further illustrate the invention.

Example 1 A stable master solution of 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 flask in the absence oflight.

9 g ofthe potassium permanganate master solution are thoroughly mixed, with stirring,with a gel prepared by milling 7 g of silica, Aerosil 200 (Degussa) with 85 grams of water adjusted to pH 3 with H2S04.

Hair is covered with the gel prepared in this manner using a spatula or a brush.

The application period lasts 10 minutes.

The hair is rinsed with waterto removed the gel.

Athicksolution containing the following is prepared before use: NH4CI 5.0 g Cellulosize WPO3H 5.0g NH40H q.s. pH 9.0 Water q.s. 80 g 1 g of 5,6-dihydroxyindole, dissolved beforehand in 20 g of anhydrous ethanol, is incorporated very quickly just before use.

The pretreated hair is covered with this solution.

The application period lasts 5 minutes.

The hair is copiously rinsed with water. A shampoo containing sodium lauryl sulphate is applied to the head.

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

Example 2 The pretreatment is identical with that of Example 1.

A thickened solution containing the foilowing is prepared before use: Dipotassium hydrogen phosphate 5.6 g Potassium dihydrogen phosphate 2.2 g CellosizeWPO3H 5.0g HCI 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 very quickly just before use.

The pretreated and rinsed hair is covered with this solution.

The application period lasts 5 minutes.

The intially grey, 90% white, hair has acquired a very intense grey tint.

Example3 The potassium permanganate master solution is that described in Example 1.

A gel is prepared by milling 7 g of silica, Aerosil 200 (Degussa) with 76 g of water adjusted to pH 3with H2S04; 18 g of the potassium permanganate master solution are incorporated thoroughly with stirring.

The hair is covered with the gel and the application period lasts 5 minutes.

The hair is rinsed with water.

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

The intially grey, 90% white, hair has become black.

Example 4 The potassium permanganate master solution is that described in Example 1.

Athickened solution is prepared by mixing 15 g of clay Gel White H/USP with 70 g of water. The pH is adjusted to 3 with a minimum quantity of sulphuric acid. 11.5 g of potassium permanganate master 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 application period lasts 5 minutes.

The hair is rinsed with water.

Athickened solution containing the following is prepared before use: NH4CI 5.0 g Carbopol 940 0.79 NH40H q.s. pH 9.0 Water q.s. 80 g 1.2 g of 5,6-dihydroxyindole, dissolved beforehand in 20-g of ethanol, are incorporated very quickly just before use.

The pretreated hair is covered with this solution.

The application period lasts 5 minutes.

The hair is copiously rinsed with water. Ashampoo containing sodium lauryl sulphate is applied tothe head.

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

Example5 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 flask in the absence of light.

Athickened solution is prepared by mixing 15 g of clay Gel White H/USP, with 50 g of water. The pH is adjusted to 3 with sulphuric acid. 30 g of potassium dichromate master solution arethen incorporated.

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

The hair is covered with this thickened solution.

The application period lasts 10 minutes.

The hair is rinsed with water.

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

The pretreated hair is covered with this solution.

The application period lasts 5 minutes.

The hair is copiously rinsed with water. A sodium lauryl sulphate shampoo is applied.

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

Example 6 A permanganate gel is prepared as described in Example 1.

A lockof bleached hair is treated for 10 minutes at ambienttemperature by the abovementioned gel and the hair is then rinsed with water to remove the gel.

Just before use, 1.29 of 5,6-dihydroxyindole is incorporated in a thick solution containing: Glycosidealkylether(Triton CG 110) 5g Guargum (JaguarHP60) 1g Ammonium chloride 5g Aqueous ammonia q.s. pH9 Water q.s. 80g This thick solution is applied for 10 minutes to the lock, which is rinsed with water, washed and dried. The hair is tinted black.

Example 7 The same solutions as in Example 6 are prepared but replacing 5,6-dihydroxyindolewith: 1.3g 2-methyl-5,6-dihydroxyindole, or 1 .4g 2,3-dimethyl-5,6-dihydroxyindole, or 1.2g 3-methyl-5,6-dihydroxyindole.

and equally replacing the lock of bleached hair by a lock of natural grey, 90% white, hair.

The following colourations are obtained: dark chestnut grey dark green grey dark blue grey Example 8 Example 1 is repeated but replacing the natural hair by permanent-waved hair and an intense black colour is obtained.

Example 9 A solution of potassium permanganate is prepared by dissolving 1 .58g KMnO4 in 1000ml water (final volume) adjusted to pH 3 using sulphuric acid. Awoven ribbon of 1g of wool is dipped into30ml ofthe Kin04 solution for 10 minutes at 30"C and is then rinsed with water.

Another solution is prepared bydissolving 1 .2g 5,6-dihydroxyindole in 20ml anhydrous ethanol. 80ml of a solution buffered at pH 9 containing 62.5g NH4CI in 1000ml water adjusted to pH 9 by aqueous ammonia is added.

The woven ribbon is colourwashed with 1 Oml of this composition and then keptfor 10 minutes at 30C in a "parafilm". The ribbon isthen rinsed with water, washed in 10% sodium laurylsulphate and dried.

The woven wool is tinted black.

The commercial names employed in the examples denote the following products: Carbopol 940 : acrylic acid homopolymer crosslinked with a polyfunctional agent sold by the Goodrich Company Cellosize WPO3H : hydroxyethylcellulose sold by the Union Carbide Company Gel White H/USP : montmorillonite sold by the Georgia Kaolin Company.

Claims

1. A process for dyeing keratinousfibres wherein a composition (a) having a pH from 2to 10 comprising, in a medium suitable for dyeing, a metal containing anion exhibiting good affinity for keratin and having a redox potential higherthanthatof a compound of formula (I) defined below; and a composition (b) having a pH of from 7 to 10 comprising, in a medium suitable for dyeing, a compound of formula (I)

in which R1 and R2, independently of each other, are hydrogen, methyl or ethyl are sequentially applied to the fibres.

2. A process according to claim 1 wherein the compound of formula (I) is 5,6-dihydroxyindole, 2-methyl-5,6-di hydroxyindole, 3-methyl-5,6-dihydroxyindole or 2,3,-dimethyl-5,6-dihydroxyindole.

3. A process according to claim 1 or 2 wherein the anion is a permanganate or dichromate anion.

4. A process according to claim 3 wherein potassium permanganate or sodium dichromate is used as the source ofofthe anion.

5. Aprocess according to anyone of claims 1 to4wherein the anion is present in a molality higherthan 10-3 mole/1000 g.

6. A process according to claim 5 wherein the anion is present in a molality offrom 10-2 mole/1000 g to 10- mole/1000 g.

7. A process according to any one of claims 1 to 6 wherein composition (a) comprises an inorganic acid to provide it with an acidicpH.

8. A process according to claim 7 wherein the pH of composition (a) is from 2 to 5.

9. A process according to any one of claims 1 to 8 wherein composition (a) is in the form of an aqueous composition containing at least one inorganic adjuvantcapable of imparting to it a viscosity permitting application to the human head.

10. A process according to any one of claims 1 to 9wherein the compound offormula (I) is present in composition (b) in an amount of from 0.5 to 2% by weight relative to the total weight of composition (b).

11. A process according to claim 10 wherein the compound offormula (I) is present in an amount of from 1 to 1.5% by weight relative to the total weight of composition (b).

12. A process according to anyone of claims 1 toil wherein the medium suitablefordyeing in composition (b) comprises water and, as a further solvent, a C1-C4 alkanol, ethylene glycol, an ethylene glycol monomethyl, monoethyl or monobutyl ether or ethylene glycol monoethyl ether acetate, propylene glycol, a monomethyl ether of propylene glycol orof dipropylene glycol or methyl lactate.

13. A process according to any one of claims 1 to 12 wherein composition (b) additionally comprises an antioxidant, buffer, perfume, surface-active agent, electrolyte, fatty amide, agentforswelling the keratinous fibres, sequestrant, film-forming agent or preservative.

14. A process according to any one of claims 1 to 13 wherein composition (a) is prepared by mixing an anhydroussolution of the compound offormula (I) as defined in claim 1 in an organicsolventwith an aqueous medium suitable for dyeing shortly before or at the time of application of the composition to the keratinousfibres.

15. A process according to anyone of claims 1 to 14wherein composition (a) is applied to the fibres and is kept in contact therewith for3 to 30 minutes, the fibres are rinsed with water, composition (b) is applied to the fibres and is kept in contact therewith for 2 to 10 minutes, and the fibres are then rinsed with water and, if desired, washed and rinsed again.

16. A process according to any one of the preceding claims wherein the keratinousfibres are human hair.

17. A process according to claim 1 substantially as hereinbefore described with reference to any one of the Examples.

18. A device with several compartments or a two-or more component pack, wherein at least one ofthe compartments contains or components comprises, in a medium suitable for dyeing, an anion as defined in any one of claims 1,3 or4and at least one ofthe compartments contains or components comprisesa compound offormula (I) as defined in anyone of claims 1,2 or lotto 13.

19. A device with several compartments or a two- or more component pack, wherein at least one ofthe compartments contains or components comprises, in a medium suitable for dyeing, an anion as defined in any one of claims 1,3 or4, at least one other compartment contains or component comprises a compound of formula (I) in an anhydrous solvent medium and at least one additional compartment contains or component comprises an aqueous medium.

20. A device or pack according to claim 19 wherein an additional compartment contains or component comprises a thickened aqueous solution.