METHOD FOR LIGHTENING OR DYEING IN THE PRESENCE OF AMMONIUM (BI)CARBONATE AND A BASE, AND DEVICE

A subject matter of the present invention is a method for lightening or dyeing keratinous fibers, comprising the use of a formulation obtained by mixing an anhydrous cosmetic composition (A) comprising one or more fatty substances and one or more surfactants, a cosmetic composition (B) comprising the combination of ammonium (bi)carbonate and at least one organic or inorganic base, and a cosmetic composition (C) comprising one or more oxidizing agents and one or more fatty substances, the content of fatty substances in the formulation representing at least 35% by weight.

The present invention also relates to a multicompartment device appropriate for the implementation of the method.

Many people have sought for a long time to modify the color of their hair and in particular to conceal their white hair. In order to do this, there essentially exist two types of dyeing operations which have been developed.

The first type of dyeing operation is "permanent" or "oxidation" dyeing, which employs dyeing compositions comprising oxidation dye precursors, generally known as oxidation bases. These oxidation bases are colorless or weakly colored compounds which, in combination with oxidizing products, can give rise, by an oxidative condensation process, to colored compounds.

It is also known that it is possible to vary the shades obtained with these oxidation bases by combining them with couplers or coloring modifiers, the latter being chosen in particular from aromatic meta-diamines, meta-aminophenols, meta-diphenols and certain heterocyclic compounds, such as indole compounds. The variety of the molecules involved as oxidation bases and couplers makes it possible to obtain a rich palette of colors.

The second type of dyeing operation is "semipermanent" dyeing or direct dyeing, which consists in applying direct dyes to the keratinous fibers, direct dyes being colored and coloring molecules having affinity for the fibers, and being able to stand, in order to allow the molecules to penetrate, by diffusion, inside the fiber, and in then rinsing them.

In order to carry out these dyeing operations, direct dyes generally employed are chosen from nitrobenzene, anthraquinone, nitropyridine, azo, xanthene, acridine, azine or triarylmethane direct dyes.

This type of method does not require the use of an oxidizing agent in order to develop the coloring. However, the use thereof, in order to obtain a lightening effect with the dyeing operation, is not ruled out. Reference is then made to a direct or semipermanent dyeing operation under lightening conditions.

Permanent or also semipermanent dyeing methods under lightening conditions thus consist in employing, with the dye composition, an aqueous composition comprising at least one oxidizing agent, under alkaline pH conditions in the great majority of cases. The role of this oxidizing agent, at least in part, is to decompose the melanin of the hair, which, depending on the nature of the oxidizing agent present, results in a more or less pronounced lightening of the fibers. Thus, for a relatively slight lightening, the oxidizing agent is generally hydrogen peroxide. When greater lightening is desired, use is normally made of peroxygenated salts, such as persulfates, for example, in the presence of hydrogen peroxide.

In the case of the methods for lightening human keratinous fibers, use is also made of an aqueous composition comprising at least one oxidizing agent, under alkaline pH conditions in the great majority of cases. In this case, the role of the agent is also to decompose the melanin with, depending on the nature of the oxidizing agent present (hydrogen peroxide, peroxygenated salts), a more or less pronounced lightening of the fibers.

One of the difficulties encountered during the use of the lightening or dyeing/lightening method of the prior art comes from the fact that they are employed under alkaline conditions and that the most commonly used alkaline agent is aqueous ammonia. The use of aqueous ammonia is particularly advantageous in methods of this type. This is because it makes it possible to adjust the pH of the composition to an alkaline pH in order to make possible the activation of the oxidizing agent. In addition, this alkaline agent brings about swelling of the keratinous fiber, with raising of the scales, which promotes the penetration of the oxidizing agent, and also of the dyes, if they are present, essentially oxidation dyes, inside the fiber and thus increases the effectiveness of the dyeing or lightening reaction.

In point of fact, this basifying agent is very volatile, which causes annoyance to the user as a result of the strong and rather unpleasant odor characteristic of ammonia which is given off during the method.

Furthermore, the amount of ammonia given off makes it necessary to apply this agent in a greater amount than the amount necessary to carry out the method, in order to compensate for this loss. This is not without consequence for the user, who remains not only bothered by the odor but who may also be confronted by greater risks of intolerance, such as, for example, irritation of the scalp, which is reflected in particular by stinging sensations.

With regard to the option of purely and simply replacing aqueous ammonia, in all or in part, with one or more other conventional basifying agents, this does not result in compositions which are as effective as those based on aqueous ammonia, in particular because these basifying agents do not result in sufficient lightening of the pigmented fibers in the presence of the oxidizing agent.

One of the objectives of the present invention is to provide methods for lightening or dyeing human keratinous fibers carried out in the presence of an oxidizing agent which do not have the disadvantages of the existing methods, disadvantages due to the presence of high contents of aqueous ammonia, but which remain at least as effective. The lightening methods have to be effective at the level of the quality and of the homogeneity of the lightening and the dyeing methods have to be effective at the level of the power of the coloration obtained and that of the chromaticity and of the homogeneity of the coloration along the fiber.

In addition, the method according to the invention makes it possible to result in high degrees of lightening, even without employing persalts.

These aims and others are achieved by the present invention, a subject matter of which is thus a method for lightening or dyeing keratinous fibers, in particular human keratinous fibers, in the presence of an oxidizing agent, in which a formulation obtained after mixing the following compositions (A), (B) and (C):

(a) an anhydrous cosmetic composition (A) comprising one or more fatty substances and one or more surfactants,

(b) a cosmetic composition (B) comprising the combination of ammonium (bi)carbonate and one or more organic or inorganic bases or one of their salts, and

(c) a cosmetic composition (C) comprising one or more fatty substances and one or more oxidizing agents;

the content of fatty substances in the formulation being at least 35% by weight, with respect to the total weight of this formulation (mixture of the compositions (A), (B) and (C)),

is applied to said fibers.

Thus, the use of the lightening method according to the invention makes it possible to obtain compositions which have lightening performances which are equivalent, indeed even superior, to those obtained with the existing compositions, in particular with the compositions based on aqueous ammonia at a high concentration.

The dyeing method according to the invention results in powerful and relatively unselective colorations, that is to say colorations which are homogeneous along the fiber.

Furthermore, the methods according to the invention employ formulations which do not give off an aggressive odor when they are applied to the hair or when they are prepared.

The present invention also relates to a multicompartment device comprising, in a first compartment, an anhydrous cosmetic composition (A) comprising one or more fatty substances and one or more surfactants, in a second compartment, a cosmetic composition (B) comprising the combination of ammonium (bi)carbonate and at least one organic or inorganic base or one of its salts and also optionally one or more oxidation dyes and/or one or more direct dyes and, in a third compartment, a cosmetic composition (C) comprising one or more oxidizing agents.

Finally a subject matter of the present invention is a four-compartment device comprising a first compartment including the anhydrous cosmetic composition (A) comprising one or more fatty substances and one or more surfactants, a second compartment including a cosmetic composition (B) comprising a combination of ammonium (bi)carbonate and at least one organic or inorganic base or one of its salts, a third compartment including one or more oxidation dyes, one or more direct dyes or their mixtures and a fourth compartment including a cosmetic composition (C) comprising one or more oxidizing agents, the compositions of the compartments being intended to be mixed before application in order to give the formulation according to the invention.

Other characteristics and advantages of the invention will become more clearly apparent on reading the description and examples which follow.

In that which will follow and unless otherwise indicated, the limits of a range of values are included within this range.

The human keratinous fibers treated by the method according to the invention are preferably the hair.

In the case of lightening without dyeing, the method according to the invention is carried out with compositions not comprising direct dye or oxidation dye precursor (bases and couplers) which are normally used for the dyeing of human keratinous fibers or else, if they are present, their total content does not exceed 0.005% by weight, with respect to the weight of each composition. This is because, at such a content, only the composition would be dyed, that is to say that an effect of dyeing keratinous fibers would not be observed. Preferably, this lightening method is employed without an oxidation base or coupler or direct dye. Anhydrous composition (A)

As indicated above, the dyeing method is employed starting from an anhydrous cosmetic composition (A).

More particularly, the term "anhydrous cosmetic composition" is understood to mean, within the meaning of the invention, a cosmetic composition exhibiting a water content of less than 5% by weight, preferably of less than 2% by weight and more preferably still of less than 1 % by weight, with respect to the weight of said composition. It should be noted that the water present in the composition is more particularly "bound water", such as the water of crystallization of the salts, or traces of water absorbed by the starting materials used in the preparation of the compositions according to the invention.

Fatty substances

As has been mentioned, the anhydrous cosmetic composition (A) comprises one or more fatty substances.

Fatty substance is understood to mean an organic compound which is insoluble in water at ordinary temperature (25°C) and at atmospheric pressure (760 mmHg) (solubility of less than 5% by weight, preferably than 1 % by weight and more preferably still than 0.1 % by weight). They exhibit, in their structure, at least one hydrocarbon chain comprising at least 6 carbon atoms or a sequence of at least two siloxane groups.

In addition, the fatty substances are generally soluble in organic solvents under the same temperature and pressure conditions, such as, for example, chloroform, ethanol, benzene, liquid petrolatum or decamethylpentacyclosiloxane.

Preferably, the fatty substances of the invention do not comprise salified or nonsalified carboxylic acid groups (COOH or COO ^" ).

More particularly, the fatty substances are chosen from C ₆ -Ci ₆ alkanes, nonsilicone oils of animal, vegetable, mineral or synthetic origin, fatty alcohols, fatty acid and/or fatty alcohol esters, nonsilicone waxes or silicones.

It should be remembered that, within the meaning of the invention, fatty alcohols, fatty esters and fatty acids more particularly exhibit at least one saturated or unsaturated and linear or branched hydrocarbon group comprising from 6 to 30 carbon atoms which is optionally substituted, in particular by one or more hydroxyl groups (in particular from 1 to 4). If they are unsaturated, these compounds can comprise from one to three conjugated or nonconjugated carbon-carbon double bonds.

As regards the C ₆ -Ci ₆ alkanes, the latter are linear, branched and optionally cyclic. Mention may be made, by way of example, of hexane, dodecane or isoparaffins, such as isohexadecane or isodecane.

Mention may be made, as oils of animal, vegetable, mineral or synthetic origin which can be used in the composition of the invention, of, for example:

- hydrocarbon oils of animal origin, such as perhydrosqualene,

- triglyceride oils of vegetable or synthetic origin, such as liquid triglycerides of fatty acids comprising from 6 to 30 carbon atoms, such as triglycerides of heptanoic or octanoic acids, or also, for example, sunflower, corn, soybean, cucumber, grape seed, sesame, hazelnut, apricot, macadamia, arara, castor or avocado oils, triglycerides of caprylic/capric acids, such as those sold by Stearineries Dubois or those sold under the names Miglyol ^® 810, 812 and 818 by Dynamit Nobel, jojoba oil or shea butter oil,

- linear or branched hydrocarbons of mineral or synthetic origin of more than 16 carbon atoms, such as liquid paraffins, which may or may not be volatile, and their derivatives, petrolatum, liquid petrolatum, polydecenes or hydrogenated polyisobutene, such as Parleam ^® ,

- fluorinated oils, such as perfluoromethylcyclopentane and perfluoro-1 ,3- dimethylcyclohexane, sold under the names of "Flutec ^® PC1 " and "Flutec ^® PC3" by BNFL Fluorochemicals: perfluoro-1 ,2-dimethylcyclobutane; perfluoroalkanes, such as dodecafluoropentane and tetradecafluorohexane, sold under the names of "PF 5050 ^® " and "PF 5060 ^® " by 3M, or bromoperfluorooctyl, sold under the name "Foralkyl ^® by Atochem; nonafluoromethoxybutane and nonafluoroethoxyisobutane; or perfluoromorpholine derivatives, such as 4-(trifluoromethyl)perfluoromorpholine, sold under the name "PF 5052 ^® " by 3M. The fatty alcohols suitable for the implementation of the invention are more particularly chosen from saturated or unsaturated and linear or branched alcohols comprising from 6 to 30 carbon atoms, preferably from 8 to 30 carbon atoms. Mention may be made, for example, of cetyl alcohol, stearyl alcohol and their mixture (cetearyl alcohol), octyldodecanol, 2-butyloctanol, 2-hexyldecanol, 2-undecylpentadecanol, oleyl alcohol or linoleyl alcohol.

As regards the fatty acid and/or fatty alcohol esters, which are advantageously different from the triglycerides mentioned above, mention may in particular be made of esters of saturated or unsaturated and linear or branched Ci-C ₂ 6 aliphatic mono- or polyacids and of saturated or unsaturated and linear or branched Ci-C ₂ 6 aliphatic mono- or polyalcohols, the total carbon number of the esters being greater than or equal to 6, more advantageously greater than or equal to 10.

Mention may be made, among the monoesters, of dihydroabietyl behenate; octyldodecyl behenate; isocetyl behenate; cetyl lactate; Ci ₂ -Ci ₅ alkyl lactate; isostearyl lactate; lauryl lactate; linoleyl lactate; oleyl lactate; (iso)stearyl octanoate; isocetyl octanoate; octyl octanoate; cetyl octanoate; decyl oleate; isocetyl isostearate; isocetyl laurate; isocetyl stearate; isodecyl octanoate; isodecyl oleate; isononyl isononanoate; isostearyl palmitate; methyl acetyl ricinoleate; myristyl stearate; octyl isononanoate; 2-ethylhexyl isononanoate; octyl palmitate; octyl pelargonate; octyl stearate; octyldodecyl erucate; oleyl erucate; ethyl and isopropyl palmitate; 2-ethylhexyl palmitate; 2-octyldecyl palmitate; alkyl myristates, such as isopropyl, butyl, cetyl, 2-octyldodecyl, myristyl or stearyl myristate, hexyl stearate, butyl stearate, isobutyl stearate; dioctyl malate, hexyl laurate or 2-hexyldecyl laurate.

Still in the context of this alternative form, use may also be made of esters of C4-C22 di- or tricarboxylic acids and of C1-C22 alcohols and esters of mono-, di- or tricarboxylic acids and of di-, tri-, tetra- or pentahydroxy C ₂ -C ₂ 6 alcohols.

Mention may in particular be made of: diethyl sebacate; diisopropyl sebacate; diisopropyl adipate; di(n-propyl) adipate; dioctyl adipate; diisostearyl adipate; dioctyl maleate; glyceryl undecylenate; octyldodecyl stearoyl stearate; pentaerythrityl monoricinoleate; pentraerythrityl tetraisononanoate; pentaerythrityl tetrapelargonate; pentraerythrityl tetraisostearate; pentaerythrityl tetraoctanoate; propylene glycol dicaprylate; propylene glycol dicaprate; tridecyl erucate; triisopropyl citrate; triisostearyl citrate; glyceryl trilactate; glyceryl trioctanoate; trioctyldodecyl citrate; trioleyl citrate; propylene glycol dioctanoate; neopentyl glycol diheptanoate; diethylene glycol diisononanoate; and polyethylene glycol distearates. Preference is given, among the abovementioned esters, to the use of ethyl, isopropyl, myristyl, cetyl or stearyl palmitate, 2-ethylhexyl palmitate, 2-octyldecyl palmitate, alkyl myristates, such as isopropyl, butyl, cetyl or 2-octyldodecyl myristate, hexyl stearate, butyl stearate, isobutyl stearate; dioctyl malate, hexyl laurate, 2-hexyldecyl laurate, isononyl isononanoate or cetyl octanoate.

The composition can also comprise, as fatty ester, esters and diesters of sugars and of C ₆ -C ₃ o, preferably C12-C22, fatty acids. It should be remembered that "sugar" is understood to mean oxygen-comprising hydrocarbon compounds which have several alcohol functional groups, with or without an aldehyde or ketone functional group, and which comprise at least 4 carbon atoms. These sugars can be monosaccharides, oligosaccharides or polysaccharides.

Mention may be made, as suitable sugars, for example, of sucrose (or saccharose), glucose, galactose, ribose, fucose, maltose, fructose, mannose, arabinose, xylose, lactose and their derivatives, in particular alkyl derivatives, such as methyl derivatives, for example methylglucose.

The esters of sugars and of fatty acids can be chosen in particular from the group consisting of the esters or mixtures of esters of sugars described above and of saturated or unsaturated and linear or branched C ₆ -C ₃ o, preferably C12-C22, fatty acids. If they are unsaturated, these compounds can comprise from one to three conjugated or non- conjugated carbon-carbon double bonds.

The esters according to this alternative form can also be chosen from mono-, di-, tri- and tetraesters, polyesters and their mixtures.

These esters can be, for example, oleates, laurates, palmitates, myristates, behenates, cocoates, stearates, linoleates, linolenates, caprates, arachidonates or their mixtures, such as, in particular, mixed oleate/palmitate, oleate/stearate or palmitate/stearate esters.

More particularly, use is made of mono- and diesters and in particular of sucrose, glucose or methylglucose mono- or dioleates, -stearates, -behenates, -oleate/palmitates, -linoleates, -linolenates or -oleate/stearates.

Mention may be made, by way of example, of the product sold under the name

Glucate ^® DO by Amerchol, which is a methylglucose dioleate.

Mention may also be made, as examples of esters or of mixtures of esters of sugars and of fatty acids, of:

- the products sold under the names F160, F140, F1 10, F90, F70 and SL40 by Crodesta, respectively denoting sucrose palmitate/stearates formed of 73% monoester and 27% di- and triester, of 61 % monoester and 39% di-, tri- and tetraester, of 52% monoester and 48% di-, tri- and tetraester, of 45% monoester and 55% di-, tri- and tetraester and of 39% monoester and 61 % di-, tri- and tetraester, and sucrose monolaurate;

- the products sold under the name Ryoto Sugar Esters, for example referenced B370 and corresponding to sucrose behenate formed of 20% monoester and 80% diester, triester and polyester;

- the sucrose mono- and dipalmitate/stearate sold by Goldschmidt under the name Tegosoft ^® PSE.

The nonsilicone wax or waxes are chosen in particular from carnauba wax, candelilla wax, esparto wax, paraffin wax, ozokerite, vegetable waxes, such as olive tree wax, rice wax, hydrogenated jojoba wax or absolute flower waxes, such as the blackcurrant flower essential wax sold by Bertin (France), or animal waxes, such as beeswaxes or modified beeswaxes (cerabellina); other waxes or waxy raw materials which can be used according to the invention are in particular marine waxes, such as that sold by Sophim under the reference M82, polyethylene waxes or polyolefin waxes in general. The silicones which can be used in the cosmetic compositions of the present invention are volatile or nonvolatile and cyclic, linear or branched silicones which may or may not be modified by organic groups and which have a viscosity from 5 x 10 ^"6 to 2.5 m ² /s at 25°C and preferably from 1 ^χ 10 ^"5 to 1 m ² /s.

The silicones which can be used in accordance with the invention can be provided in the form of oils, waxes, resins or gums.

Preferably, the silicone is chosen from polydialkylsiloxanes, in particular polydimethylsiloxanes (PDMS), and polysiloxanes which are organomodified, comprising at least one functional group chosen from poly(oxyalkylene) groups, aminated groups and alkoxy groups.

Organopolysiloxanes are defined in more detail in the work by Walter Noll,

"Chemistry and Technology of Silicones" (1968), Academic Press. They can be volatile or non-volatile.

When they are volatile, the silicones are chosen more particularly from those having a boiling point of between 60°C and 260°C and more particularly still from:

(i) cyclic polydialkylsiloxanes comprising from 3 to 7, preferably from 4 to 5, silicon atoms. They are, for example, octamethylcyclotetrasiloxane, sold in particular under the name of Volatile Silicone ^® 7207 by Union Carbide or Silbione ^® 70045 V2 by Rhodia, decamethylcyclopentasiloxane, sold under the name of Volatile Silicone ^® 7158 by Union Carbide and Silbione ^® 70045 V5 by Rhodia, and their mixtures.

Mention may also be made of cyclocopolymers of the dimethylsiloxanes/methylalkylsiloxane type, such as Silicone Volatile ^® FZ 3109, sold by Union Carbide, of formula: D" - D'— ^■ D"— D'—

CH, ' ' CH ₃

i I

Wlth D" : —Si - O— Wlth D' : - Si - O—

CH ₃ C _e H ₁₇

Mention may also be made of mixtures of cyclic polydialkylsiloxanes with silicon- derived organic compounds, such as the mixture of octamethylcyclotetrasiloxane and of tetratrimethylsilylpentaerythritol (50/50) and the mixture of octamethylcyclotetrasiloxane and of 1 ,1 '-oxy(2,2,2',2',3,3'-hexatrimethylsilyloxy)bisneopentane;

(ii) the linear volatile polydialkylsiloxanes having from 2 to 9 silicon atoms and exhibiting a viscosity of less than or equal to 5 x 10 ^"6 m ² /s at 25°C. They are, for example, decamethyltetrasiloxane, sold in particular under the name "SH 200" by Toray Silicone. Silicones coming within this category are also described in the article published in Cosmetics and Toiletries, Vol. 91 , Jan. 76, pp. 27-32, Todd & Byers, "Volatile silicone fluids for cosmetics".

Use is preferably made of nonvolatile polydialkylsiloxanes, polydialkylsiloxane gums and resins, polyorganosiloxanes modified by the organofunctional groups above, and their mixtures.

These silicones are chosen more particularly from polydialkylsiloxanes, among which may be mainly mentioned polydimethylsiloxanes comprising trimethylsilyl end groups. The viscosity of the silicones is measured at 25°C according to the standard ASTM 445, Appendix C.

Mention may be made, among these polydialkylsiloxanes, without implied limitation, of the following commercial products:

- Silbione ^® oils of the 47 and 70 047 series or Mirasil ^® oils sold by Rhodia, such as, for example, the 70 047 V 500 000 oil;

- oils of the Mirasil ^® series sold by Rhodia;

- oils of the 200 series from Dow Corning, such as DC200 with a viscosity of 60 000 mm ² /s;

- Viscasil ^® oils from General Electric and some oils of the SF series (SF 96, SF 18) from General Electric.

Mention may also be made of polydimethylsiloxanes comprising dimethylsilanol end groups, known under the name of dimethiconol (CTFA), such as the oils of the 48 series from Rhodia.

In this category of polydialkylsiloxanes, mention may also be made of the products sold under the names "Abil Wax ^® 9800" and "9801 " by Goldschmidt, which are polydi(Ci- C ₂ o)alkylsiloxanes.

The silicone gums which can be used in accordance with the invention are in particular polydialkylsiloxanes, preferably polydimethylsiloxanes, having high number- average molecular weights of between 200 000 and 1 000 000, used alone or as a mixture in a solvent. This solvent can be chosen from volatile silicones, polydimethylsiloxane (PDMS) oils, polyphenylmethylsiloxane (PPMS) oils, isoparaffins, polyisobutylenes, methylene chloride, pentane, dodecane, tridecane or their mixtures.

Products which can more particularly be used in accordance with the invention are mixtures, such as:

- the mixtures formed from a polydimethylsiloxane hydroxylated at the chain end or dimethiconol (CTFA) and from a cyclic polydimethylsiloxane, also known as cyclomethicone (CTFA), such as the product Q2 1401 sold by Dow Corning;

- the mixtures of a polydimethylsiloxane gum and of a cyclic silicone, such as the product SF 1214 Silicone Fluid from General Electric; this product is a gum SF 30, corresponding to a dimethicone, having a number-average molecular weight of 500 000, dissolved in the oil SF 1202 Silicone Fluid, corresponding to the decamethylcyclopentasiloxane;

- the mixtures of two PDMSs with different viscosities and more particularly of a PDMS gum and of a PDMS oil, such as the product SF 1236 from General Electric. The product SF 1236 is the mixture of an SE 30 gum defined above, having a viscosity of 20 m ² /s, and of an SF 96 oil, with a viscosity of 5 x 10 ^"6 m ² /s. This product preferably comprises 15% of SE 30 gum and 85% of an SF 96 oil.

The organopolysiloxane resins which can be used in accordance with the invention are crosslinked siloxane systems including the units:

R ₂ Si0 ₂ / ₂ , R3S1O1/2, RS1O3/2 and Si0 _4/2 ,

in which R represents an alkyl having from 1 to 16 carbon atoms. Those which are particularly preferred among these products are those in which R denotes a lower d-C ₄ alkyl group, more particularly methyl.

Mention may be made, among these resins, of the product sold under the name

"Dow Corning 593" or those sold under the names "Silicone Fluid SS 4230" and "SS 4267" by General Electric and which are silicones with a dimethyl/trimethylsiloxane structure.

Mention may also be made of resins of the trimethylsiloxysilicate type, sold in particular under the names X22-4914, X21 -5034 and X21 -5037 by Shin-Etsu.

The organomodified silicones which can be used in accordance with the invention are silicones as defined above which comprise, in their structure, one or more organofunctional groups attached via a hydrocarbon group.

In addition to the silicones described above, the organomodified silicones can be polydiarylsiloxanes, in particular polydiphenylsiloxanes, and polyalkylarylsiloxanes functionalized by the abovementioned organofunctional groups.

The polyalkylarylsiloxanes are chosen in particular from polydimethyl/methylphenylsiloxanes or polydimethyl/diphenylsiloxanes, linear and/or branched, with a viscosity ranging from 1 x 10 ^"5 to 5 x 10 ^"2 m ² /s at 25°C.

Mention may be made, among these polyalkylarylsiloxanes, by way of examples, of the products sold under the following names:

. Silbione ^® oils of the 70 641 series from Rhodia;

. oils of the Rhodorsil ^® 70 633 and 763 series from Rhodia;

. the oil Dow Corning 556 Cosmetic Grade Fluid from Dow Corning;

. silicones of the PK series from Bayer, such as the product PK20;

. silicones of the PN and PH series from Bayer, such as the products PN 1000 and PH 1000;

. certain oils of the SF series from General Electric, such as SF 1023, SF 1 154, SF 1250 and SF 1265.

Mention may be made, among organomodified silicones, of the polyorganosiloxanes comprising:

- polyethyleneoxy and/or polypropyleneoxy groups optionally comprising C ₆ -C ₂ 4 alkyl groups, such that the products known as dimethicone copolyol, sold by Dow Corning under the name DC 1248, or the Silwet ^® L 722, L 7500, L 77 and L 71 1 oils from Union Carbide and Ci ₂ alkyl methicone copolyol, sold by Dow Corning under the name Q2 5200;

- substituted or unsubstituted aminated groups, such as the products sold under the names GP 4 Silicone Fluid and GP 7100 by Genesee or the products sold under the names Q2 8220 and Dow Corning 929 or 939 by Dow Corning. The substituted aminated groups are in particular amino(Ci-C ₄ alkyl) groups;

- alkoxylated groups, such as the products sold under the names "Silicone Copolymer F-755" by SWS Silicones and Abil Wax ^® 2428, 2434 and 2440 by Goldschmidt. Preferably, the fatty substances do not comprise a C ₂ -C ₃ oxyalkylene unit or a glycerol unit.

More particularly, the fatty substances are chosen from compounds which are liquid or pasty at ambient temperature and at atmospheric pressure.

Preferably, the fatty substance is a compound which is liquid at a temperature of 25°C and at atmospheric pressure.

The fatty substances are advantageously chosen from C ₆ -Ci ₆ alkanes, nonsilicone oils of vegetable, mineral or synthetic origin, fatty alcohols, fatty acid and/or fatty alcohol esters, silicones or their mixtures.

Preferably, the fatty substance is chosen from liquid petrolatum, C ₆ -Ci ₆ alkanes, polydecenes, liquid fatty acid and/or fatty alcohol esters, or their mixtures.

Better still, the fatty substance is chosen from liquid petrolatum, C ₆ -Ci ₆ alkanes and polydecenes.

The anhydrous composition (A) according to the invention advantageously comprises at least 25% by weight of fatty substance. The anhydrous composition (A) according to the invention in particular exhibits a content of fatty substances ranging from 25 to 80% by weight, preferably from 50 to 80% by weight and more advantageously still from 60 to 80% by weight, with respect to the weight of the composition (A).

Surfactants

The anhydrous cosmetic composition (A) also comprises one or more surfactants. Preferably, the surfactant or surfactants are chosen from nonionic surfactants or from anionic surfactants.

The term "anionic surface-active agent" is understood to mean a surfactant comprising only anionic groups as ionic or ionizable groups. These anionic groups are preferably chosen from C0 ₂ H, C0 ₂ ^" , S0 ₃ H, S0 ₃ ^" , OS0 ₃ H, OS0 ₃ ^" , H ₂ P0 ₃ , HP0 ₃ ^" , P0 ₃ ^2" , H ₂ P0 ₂ , HP0 ₂ , HP0 ₂ ^" , P0 ₂ ^" , POH or PO ^" groups.

Mention may be made, as examples of anionic surface-active agents which can be used in the composition according to the invention, of alkyl sulfates, alkyl ether sulfates, alkylamido ether sulfates, alkylaryl polyether sulfates, monoglyceride sulfates, alkylsulfonates, alkylamidesulfonates, alkylarylsulfonates, oc-olefinsulfonates, paraffinsulfonates, alkyl sulfosuccinates, alkyl ether sulfosuccinates, alkylamide sulfosuccinates, alkyl sulfoacetates, acylsarcosinates, acylglutamates, alkyl sulfosuccinamates, acylisethionates and N-acyltaurates, salts of alkyl monoesters of polyglycosidepolycarboxylic acids, acyl lactylates, salts of D-galactosideuronic acids, salts of alkyl ether carboxylic acids, salts of alkylaryl ether carboxylic acids, salts of alkylamido ether carboxylic acids; and the corresponding nonsalified forms of all these compounds; the alkyl and acyl groups of all these compounds comprising from 6 to 24 carbon atoms and the aryl group denoting a phenyl group.

These compounds can be oxyethylenated and then preferably comprise from 1 to 50 ethylene oxide units. The salts of C ₆ -C ₂₄ alkyl monoesters of polyglycosidepolycarboxylic acids can be chosen from polyglycoside-(C ₆ -C ₂₄ alkyl citrates), polyglycoside-(C ₆ -C ₂₄ alkyl tartrates) and polyglycoside-(C ₆ -C ₂₄ alkyl sulfosuccinates).

When the anionic surface-active agent or agents (ii) are in the salt form, it (they) can be chosen from salts of alkali metals, such as the sodium or potassium salt and preferably the sodium salt, ammonium salts, salts of amines, in particular of aminoalcohols, or salts of alkaline earth metals, such as the magnesium salt.

Mention may in particular be made, as example of salts of aminoalcohols, of mono-, di- and triethanolamine salts, mono-, di- or triisopropanolamine salts, 2-amino-2-methyl- 1 -propanol salts, 2-amino-2-methyl-1 ,3-propanediol salts

tris(hydroxymethyl)aminomethane salts.

Use is preferably made of salts of alkali metals or alkaline earth metals and in particular the sodium or magnesium salts.

Preference is given, among anionic surfactants, to the use according to the invention of salts of alkyl sulfates and of alkyl ether sulfates and their mixtures. The nonionic surfactants are more particularly chosen from mono- or polyoxyalkylenated or mono- or polyglycerolated nonionic surfactants. The oxyalkylenated units are more particularly oxyethylenated or oxypropylenated units, or their combination, preferably oxyethylenated units. Mention may be made, as examples of oxyalkylenated nonionic surfactants, of:

• oxyalkylenated (C ₈ -C ₂ 4 alkyl)phenols,

• oxyalkylenated, saturated or unsaturated, linear or branched, C ₈ -C ₃ o alcohols,

• oxyalkylenated, saturated or unsaturated, linear or branched, C ₈ -C ₃ o amides,

• esters of saturated or unsaturated and linear or branched C ₈ -C ₃ o acids and of polyethylene glycols,

• esters of saturated or unsaturated and linear or branched C ₈ -C ₃ o acids and of sorbitol which are polyoxyethylenated,

• oxyethylenated, saturated or unsaturated, vegetable oils,

• condensates of ethylene oxide and/or of propylene oxide, inter alia, alone or as mixtures.

The surfactants exhibit a number of moles of ethylene oxide and/or of propylene oxide of between 1 and 100, more particularly between 2 and 50, preferably between 2 and 30. Advantageously, the nonionic surfactants do not comprise oxypropylenated units.

In accordance with a preferred embodiment of the invention, the oxyalkylenated nonionic surfactants are chosen from oxyethylenated, saturated or unsaturated, C ₈ -C ₃₀ alcohols comprising from 1 to 100 mol of ethylene oxide or esters of saturated or unsaturated and linear or branched C ₈ -C ₃₀ acids and of sorbitol which are polyoxyethylenated and which comprise from 1 to 100 mol of ethylene oxide.

Use is preferably made, as examples of mono- or polyglycerolated nonionic surfactants, of mono- or polyglycerolated, saturated or unsaturated, C ₈ -C ₄ o alcohols.

In particular, the mono- or polyglycerolated C ₈ -C ₄ o alcohols correspond to the following formula:

RO-[CH ₂ -CH(CH ₂ OH)-0] _m -H

in which R represents a linear or branched C ₈ -C ₄₀ , preferably C ₈ -C ₃₀ , alkyl or alkenyl radical and m represents a number ranging from 1 to 30 and preferably from 1 to 10. Mention may be made, as examples of compounds suitable in the context of the invention, of lauryl alcohol comprising 4 mol of glycerol (INCI name: Polyglyceryl-4 Lauryl Ether), lauryl alcohol comprising 1.5 mol of glycerol, oleyl alcohol comprising 4 mol of glycerol (INCI name: Polyglyceryl-4 Oleyl Ether), oleyl alcohol comprising 2 mol of glycerol (INCI name: Polyglyceryl-2 Oleyl Ether), cetearyl alcohol comprising 2 mol of glycerol, cetearyl alcohol comprising 6 mol of glycerol, oleyl/cetyl alcohol comprising 6 mol of glycerol and octadecanol comprising 6 mol of glycerol.

The alcohol can represent a mixture of alcohols in the same way as the value of m represents a statistical value, which means that, in a commercial product, several types of polyglycerolated fatty alcohols can coexist in the form of a mixture.

Preference is more particularly given, among mono- or polyglycerolated alcohols, to the use of C ₈ /Ci ₀ alcohol comprising one mol of glycerol, C ₁₀ /C ₁₂ alcohol comprising 1 mol of glycerol and C ₁₂ alcohol comprising 1.5 mol of glycerol. Preferably, the surfactant or surfactants present in the composition are chosen from nonionic surfactants.

More preferably still, the nonionic surfactants are chosen from polyoxyethylenated sorbitol esters, polyoxyethylenated fatty alcohols and their mixtures. The content of surfactant(s) in the composition more particularly represents from

0.1 to 50% by weight, preferably from 0.5 to 30% by weight, with respect to the weight of the composition.

Additives

The anhydrous composition (A) can also include various adjuvants conventionally used in compositions for lightening or dyeing the hair, such as anionic, cationic, nonionic, amphoteric or zwitterionic polymers or their mixtures; inorganic thickening agents, in particular fillers, such as clays or talc; organic thickening agents, with in particular anionic, cationic, nonionic and amphoteric polymeric associative thickeners; antioxidants; penetration agents; sequestering agents; fragrances; dispersing agents; film-forming agents; ceramides; preservatives; or opacifying agents.

The above adjuvants are generally present in an amount of, for each of them, between 0.01 and 20% by weight, with respect to the weight of the composition (A).

The composition can in particular comprise one or more inorganic thickening agents chosen from organophilic clays, pyrogenic silicas or their mixtures.

The organophilic clay can be chosen from montmorillonite, bentonite, hectorite, attapulgite, sepiolite, and their mixtures. The clay is preferably a bentonite or a hectorite.

These clays can be modified with a chemical compound chosen from quaternary amines, tertiary amines, amine acetates, imidazolines, amine soaps, fatty sulfates, alkylarylsulfonates, amine oxides, and their mixtures. Mention may be made, as organophilic clays, of quaternium-18 bentonites, such as those sold under the names Bentone 3, Bentone 38 or Bentone 38V by Rheox, Tixogel VP by United Catalyst or Claytone 34, Claytone 40 or Claytone XL by Southern Clay; stearalkonium bentonites, such as those sold under the names Bentone 27 by Rheox, Tixogel LG by United Catalyst or Claytone AF or Claytone APA by Southern Clay; or quaternium-18/benzalkonium bentonite, such as those sold under the names Claytone HT or Claytone PS by Southern Clay.

Pyrogenic silicas can be obtained by high-temperature hydrolysis of a volatile silicon compound in an oxyhydrogen flame, producing a finely divided silica. This process makes it possible in particular to obtain hydrophilic silicas which exhibit a large number of silanol groups at their surfaces. Such hydrophilic silicas are sold, for example, under the names "Aerosil 130 ^® ", "Aerosil 200 ^® ", "Aerosil 255 ^® ", "Aerosil 300 ^® " or "Aerosil 380 ^® " by Degussa or "Cab-O-Sil HS-5 ^® ", "Cab-O-Sil EH-5 ^® ", "Cab-O-Sil LM-130 ^® ", "Cab-O-Sil MS- 55 ^® " or "Cab-O-Sil M-5 ^® " by Cabot.

It is possible to chemically modify the surface of the silica by a chemical reaction for the purpose of decreasing the number of silanol groups. It is possible in particular to substitute silanol groups by hydrophobic groups: a hydrophobic silica is then obtained.

The hydrophobic groups can be:

- trimethylsiloxyl groups, which are obtained in particular by treatment of pyrogenic silica in the presence of hexamethyldisilazane. Silicas thus treated are named "Silica silylate" according to the CTFA (6th edition, 1995). They are sold, for example, under the references "Aerosil R812 ^® " by Degussa or "Cab-O-Sil TS-530 ^® " by Cabot.

- dimethylsilyloxyl or polydimethylsiloxane groups, which are obtained in particular by treatment of pyrogenic silica in the presence of polydimethylsiloxane or of dimethyldichlorosilane. Silicas thus treated are named "Silica dimethyl silylate" according to the CTFA (6th edition, 1995). They are sold, for example, under the references "Aerosil R972 ^® " or "Aerosil R974 ^® " by Degussa or "Cab-O-Sil TS-610 ^® " or "Cab-O-Sil TS- 720 ^® " by Cabot.

The pyrogenic silica preferably exhibits a particle size which can be nanometric to micrometric, for example ranging from approximately 5 to 200 nm.

Preferably, the composition comprises a hectorite, an organomodified bentonite or an optionally modified pyrogenic silica.

When it is present, the inorganic thickening agent represents from 1 to 30% by weight, with respect to the weight of the composition.

The composition can also comprise one or more organic thickening agents.

These thickening agents can be chosen from amides of fatty acids (coconut oil diethanolamides or monoethanolamide, oxyethylenated alkyl ether carboxylic acid monoethanolamide), polymeric thickeners, such as cellulose thickeners (hydroxyethylcellulose, hydroxypropylcellulose, carboxymethylcellulose), guar gum and its derivatives (hydroxypropyl guar), gums of microbial origin (xanthan gum, scleroglucan gum), crosslinked homopolymers of acrylic acid or of acrylamidopropanesulfonic acid and associative polymers (polymers comprising hydrophilic regions and hydrophobic regions having a fatty chain (alkyl or alkenyl chain comprising at least 10 carbon atoms) which are capable, in an aqueous medium, of reversibly associating with one another or with other molecules).

According to a specific embodiment, the organic thickening agent is chosen from cellulose thickeners (hydroxyethylcellulose, hydroxypropylcellulose, carboxymethylcellulose), guar gum and its derivatives (hydroxypropyl guar), gums of microbial origin (xanthan gum, scleroglucan gum) or crosslinked homopolymers of acrylic acid or of acrylamidopropanesulfonic acid, preferably from cellulose thickeners with in particular hydroxyethylcellulose.

The content of organic thickening agent(s), if they are present, usually varies from 0.01 % to 20% by weight, with respect to the weight of the composition, preferably from 0.1 % to 5% by weight.

Advantageously, the composition (A) is provided in the form of a gel or of a cream.

Cosmetic composition (B)

The cosmetic composition (B) comprises the combination of ammonium (bi)carbonate and one or more organic bases or their salts. Preferably, the cosmetic composition (B) comprises a combination of ammonium carbonate and one or more organic bases or their salts.

Ammonium (bi)carbonate and organic or inorganic base(s)

As regards the organic bases or their salts, the latter are more particularly chosen from amines and preferably from organic amines having a pK _b at 25°C of less than 12, preferably of less than 10 and more advantageously still of less than 6. It should be noted that this is the pK _b corresponding to the functional group of highest basicity.

According to a first alternative form of the invention, the organic phase comprises a primary, secondary or tertiary amine functional group and one or more linear or branched Ci-C ₈ alkyl groups carrying one or more hydroxyl radicals.

The organic bases chosen from alkanolamines, such as mono-, di- or trialkanolamines, comprising from one to three identical or different CrC ₄ hydroxyalkyl radicals, are suitable in particular for the implementation of the invention.

Mention may be made, among compounds of this type, of monoethanolamine, diethanolamine, triethanolamine, monoisopropanolamine, diisopropanolamine, N-dimethylaminoethanolamine (Ν,Ν-dimethylethanolamine), 2-amino-2-methyl-1 - propanol, triisopropanolamine, 2-amino-2-methyl-1 ,3-propanediol, 3-amino-1 ,2- propanediol, 3-dimethylamino-1 ,2-propanediol or tris(hydroxymethyl)aminomethane.

The organic bases of the following formula: Rx Rz

\ /

N W - N

_ / \

Ry Rt

in which W is a Ci-C ₆ alkylene residue optionally substituted by a hydroxyl group or a Ci-C ₆ alkyl radical and Rx, Ry, Rz and Rt, which are identical or different, represent a hydrogen atom or a CrC ₆ alkyl, CrC ₆ hydroxyalkyl or CrC ₆ aminoalkyl radical, are also suitable.

Mention may be made, as example of such amines, of 1 ,3-diaminopropane, 1 ,3-diamino-2-propanol, spermine or spermidine.

According to another alternative form of the invention, the organic base is chosen from amino acids.

More particularly, the amino acids which can be used are of natural or synthetic origin, in the L, D or racemic form, and comprise at least one acid functional group chosen more particularly from carboxylic acid, sulfonic acid, phosphonic acid or phosphoric acid functional groups. The amino acids can occur in a neutral or ionic form.

Advantageously, the amino acids are basic amino acids comprising an additional amine functional group, optionally included in a ring or in a ureido functional group.

Such basic amino acids are preferably chosen from those corresponding to the following formula (I):

NH ₂

R— CH ₂ — CH (I)

C0 ₂ H

in which R denotes a group chosen from: N ^H -(CH ₂ ) ₃ NH ₂ -(CH ₂ ) ₂ NH ₂ -(CH ₂ ) ₂ NHCONH ₂ ....

The compounds corresponding to the formula (I) are histidine, lysine, arginine, ornithine or citrulline.

Mention may in particular be made, as amino acids which can be used in the present invention, of aspartic acid, glutamic acid, alanine, arginine, ornithine, citrulline, asparagine, carnitine, cysteine, glutamine, glycine, histidine, lysine, isoleucine, leucine, methionine, N-phenylalanine, proline, serine, taurine, threonine, tryptophan, tyrosine and valine.

The amino acids which are particularly preferred are arginine, lysine, histidine or their mixtures.

According to another alternative form of the invention, the organic base is chosen from amines of heterocyclic type. Mention may in particular be made, in addition to the histidine already mentioned in the amino acids, of pyridine, piperidine, imidazole, triazole, tetrazole or benzimidazole. According to another alternative form of the invention, the organic base is chosen from amino acid dipeptides. Mention may in particular be made, as amino acid dipeptides which can be used in the present invention, of carnosine, anserine and baleine.

According to another alternative form of the invention, the organic base is chosen from compounds comprising a guanidine functional group. Mention may in particular be made, as amines of this type which can be used in the present invention, in addition to the arginine already mentioned as an amino acid, of creatine, creatinine, 1 ,1 -dimethylguanidine, 1 ,1 -diethylguanidine, glycocyamine, metformin, agmatine, N-amidinoalanine, 3-guanidinopropionic acid, 4-guanidinobutyric acid and 2-([amino(imino)methyl]amino)ethane-1 -sulfonic acid.

As regards the salts of the abovementioned amines, the latter can be organic or inorganic.

More particularly, the organic salts are chosen from the salts of organic acids, such as citrates, lactates, glycolates, gluconates, acetates, propionates, fumarates, oxalates and tartrates.

More particularly, the inorganic salts are chosen from hydrohalides (for example hydrochlorides), carbonates, hydrogencarbonates, sulfates, hydrogenphosphates and phosphates.

Preferably, the organic base is an alkanolamine. More preferably, the organic base is chosen from 2-amino-2-methyl-1 -propanol, monoethanolamine or their mixtures. More preferably still, the organic base is monoethanolamine. Preferably, when the method is a dyeing-free lightening method, the composition

(B) does not comprise persalts.

When the method is a dyeing-free lightening method, the ammonium (bi)carbonate and the organic base or bases can be employed as a mixture with one or more solid or pasty adjuvants and preferably pulverulent adjuvants. The adjuvants can then be chosen from clays, salts other than the ammonium (bi)carbonate or amine salts mentioned above, if they are present, anionic, nonionic, cationic or zwitterionic surfactants, natural or synthetic thickeners, optionally modified starch, glass beads, silica, nylon, alumina, titanium dioxide, zeolites, poly(methyl methacrylate) (PMMA), chitosan, maltodextrin, cyclodextrin, mono- or disaccharides, such as glucose, sucrose, sorbitol or fructose, zinc oxide, zirconium oxide, silica beads, talc, borosilicates, in particular calcium borosilicate, polyethylene, polytetrafluoroethylene (PTFE), cellulose and its derivatives, superabsorbent compounds, magnesium carbonate, calcium carbonate, polyacrylamide, porous hydroxyapatite, sawdust, focus powder, crosslinked polyvinylpyrrolidone, calcium alginate, active charcoal, poly(vinylidene chloride/acrylonitrile) particles, in particular those sold under the general name of "Expancel ^® " by Akzo Nobel and under the specific references "Expancel ^® WE" or "Expancel ^® DE", and their mixtures. Inorganic bases are understood to mean, within the meaning of the present invention, aqueous ammonia and any compound having, in its structure, one or more elements from Groups 1 to 13 of the Periodic Table of the Elements other than hydrogen.

According to a first specific embodiment of the invention, the inorganic base is aqueous ammonia.

According to second specific embodiment of the invention, the inorganic base or bases comprise one or more elements from Groups 1 and 2 of the Periodic Table of the Elements other than hydrogen.

In a preferred alternative form, the inorganic base or bases exhibit the following structure (T):

(Z ₁ ^x -) _m (Z ₂ ^y+ ) _n (T)

in which:

Z ₂ denotes a metal from Groups 1 to 13 of the Periodic Table of the Elements, preferably 1 or 2, such as sodium or potassium;

Zi* denotes an anion chosen from the C0 ₃ ^2" , OH ^" , HC0 ₃ ^" , Si0 ₃ ^2" , HP0 ₄ ^2" , P0 ₄ ^3" or

B ₄ 0 ₇ ^2" ions, preferably from the C0 ₃ ^2" , OH ^" or Si0 ₃ ^2" ions;

x denotes 1 , 2 or 3;

y denotes 1 , 2, 3 or 4;

m and n denote, independently of one another, 1 , 2, 3 or 4;

with n x y = m x x.

Preferably, the inorganic base or bases correspond to the following formula (Z ₁ ^x" ) _m (Z ₂ ^y+ ) _n , in which Z ₂ denotes a metal from Groups 1 and 2 of the Periodic Table of the Elements, Zi ^x" denotes an anion chosen from the C0 ₃ ^2" , OH ^" or Si0 ₃ ^2" ions, x has a value of 1 , y denotes 1 or 2, and m and n denote, independently of one another, 1 or 2 with n x y = m x x.

Mention may be made, as inorganic base (T) which can be used according to the invention, of sodium carbonate, potassium carbonate, sodium hydroxide, potassium hydroxide, sodium metasilicate or potassium metasilicate. Advantageously, the content of ammonium (bi)carbonate ranges from 0.1 to 40% by weight, preferably from 0.1 to 20% by weight and more preferably from 0.5 to 20% by weight, with respect to the weight of the composition (B).

Furthermore, the content of organic or inorganic base(s) or of salt(s) more particularly ranges from 0.5 to 50% by weight, with respect to the weight of the composition (B).

Preferably, the content of organic base(s) or of salt(s) ranges from 10 to 45% by weight, with respect to the weight of the composition (B).

Preferably, the content of inorganic base(s) or of salt(s) ranges from 2 to 35% by weight, with respect to the weight of the composition (B).

It should be noted that, preferably, the organic base(s)/ammonium (bi)carbonate molar ratio ranges from 0.1 to 50 and preferably from 1 to 20.

Furthermore, and preferably, the inorganic base(s)/ammonium (bi)carbonate molar ratio ranges from 0.1 to 100 and preferably from 1 to 50.

Solvents

The composition (B) can be an anhydrous or aqueous composition.

Aqueous composition is understood to mean a composition comprising more than 5% by weight of water, preferably more than 10% by weight of water and advantageously still more than 20% by weight of water.

Preferably, the cosmetic composition (B) is an aqueous composition.

Preferably, the composition (B) comprises water. More preferably still, the concentration of water can range from 10 to 90%, better still from 20 to 80%, of the total weight of the composition.

The cosmetic composition (B) can optionally comprise one or more solvents.

Mention may for example be made, as an organic solvent, of linear or branched C ₂ -C ₄ alkanols, such as ethanol and isopropanol, glycerol, polyols and polyol ethers, such as 2-butoxyethanol, propylene glycol, dipropylene glycol, propylene glycol monomethyl ether, diethylene glycol monoethyl ether and diethylene glycol monomethyl ether, aromatic alcohols or ethers, such as benzyl alcohol or phenoxyethanol, and their mixtures.

The solvent or solvents, if they are present, represent a content normally ranging from 1 to 40% by weight, with respect to the weight of the cosmetic composition (B), preferably ranging from 5 to 30% by weight.

The cosmetic composition (B) may also comprise conventional additives, such as those which were listed above and to which reference may be made.

The pH of the cosmetic composition (B), if it is aqueous, is between 8 and 1 1. The pH is adjusted by using acidifying agents.

Mention may be made, among acidifying agents, by way of example, of inorganic or organic acids, such as hydrochloric acid, orthophosphoric acid, sulfuric acid, carboxylic acids, such as acetic acid, tartaric acid, citric acid or lactic acid, or sulfonic acids.

The use is not excluded, in order to adjust the pH, in addition to the organic base or bases and ammonium (bi)carbonate, of aqueous ammonium, although the latter compound is not preferred. If, however, aqueous ammonia is also employed as basifying agent in the composition (B), then the aqueous ammonia content of the composition (B) will preferably not exceed 0.03% by weight (expressed as NH ₃ ) and better still will not exceed 0.01 % by weight, with respect to the weight of the formulation obtained by mixing the compositions (A), (B) and (C).

Dyes

The dyeing method according to the invention is carried out in the presence of a cosmetic composition (B) comprising one or more oxidation dyes, one or more direct dyes or their mixtures.

The oxidation dyes are generally chosen from oxidation bases, optionally in combination with one or more couplers.

By way of example, the oxidation bases are chosen from para-phenylenediamines, bisphenylalkylenediamines, para-aminophenols, ortho-aminophenols, heterocyclic bases and their addition salts.

Mention may be made, among para-phenylenediamines, by way of example, of para-phenylenediamine, para-toluylenediamine, 2-chloro-para-phenylenediamine, 2,3-dimethyl-para-phenylenediamine, 2,6-dimethyl-para-phenylenediamine, 2,6-diethyl- para-phenylenediamine, 2,5-dimethyl-para-phenylenediamine, N,N-dimethyl-para- phenylenediamine, Ν,Ν-diethyl-para-phenylenediamine, N,N-dipropyl-para- phenylenediamine, 4-amino-N,N-diethyl-3-methylaniline, N,N-bis( -hydroxyethyl)-para- phenylenediamine, 4-N,N-bis( -hydroxyethyl)amino-2-methylaniline, 4-N,N-bis( - hydroxyethyl)amino-2-chloroaniline, 2-( -hydroxyethyl)-para-phenylenediamine, 2-fluoro- para-phenylenediamine, 2-isopropyl-para-phenylenediamine, N-( -hydroxypropyl)-para- phenylenediamine, 2-hydroxymethyl-para-phenylenediamine, N,N-dimethyl-3-methyl- para-phenylenediamine, N,N-(ethyl, -hydroxyethyl)-para-phenylenediamine,

N-( ,y-dihydroxypropyl)-para-phenylenediamine, N-(4'-aminophenyl)-para- phenylenediamine, N-phenyl-para-phenylenediamine, 2-( -hydroxyethyloxy)-para- phenylenediamine, 2-( -acetylaminoethyloxy)-para-phenylenediamine, N-( -methoxyethyl)-para-phenylenediamine, 4-aminophenylpyrrolidine, 2-thienyl-para- phenylenediamine, 2-( -hydroxyethylamino)-5-aminotoluene, 3-hydroxy-1 -(4'- aminophenyl)pyrrolidine and their addition salts with an acid.

Among the para-phenylenediamines mentioned above, para-phenylenediamine, para-toluylenediamine, 2-isopropyl-para-phenylenediamine, 2-( -hydroxyethyl)-para- phenylenediamine, 2-( -hydroxyethyloxy)-para-phenylenediamine, 2,6-dimethyl-para- phenylenediamine, 2,6-diethyl-para-phenylenediamine, 2,3-dimethyl-para- phenylenediamine, N,N-bis( -hydroxyethyl)-para-phenylenediamine, 2-chloro-para- phenylenediamine, 2-( -acetylaminoethyloxy)-para-phenylenediamine and their addition salts with an acid are particularly preferred.

Mention may be made, among bisphenylalkylenediamines, by way of example, of N,N'-bis( -hydroxyethyl)-N,N'-bis(4'-aminophenyl)-1 ,3-diaminopropanol, N,N'-bis(P- hydroxyethyl)-N,N'-bis(4'-aminophenyl)ethylenediamine, N,N'-bis(4-aminophenyl)- tetramethylenediamine, N,N'-bis( -hydroxyethyl)-N,N'-bis(4-aminophenyl)tetramethylene- diamine, N,N'-bis(4-methylaminophenyl)tetramethylenediamine, N,N'-bis(ethyl)-N,N'- bis(4'-amino-3'-methylphenyl)ethylenediamine, 1 ,8-bis(2,5-diaminophenoxy)-3,6- dioxaoctane and their addition salts.

Mention may be made, among para-aminophenols, by way of example, of para- aminophenol, 4-amino-3-methylphenol, 4-amino-3-fluorophenol, 4-amino-3-chlorophenol,

4- amino-3-(hydroxymethyl)phenol, 4-amino-2-methylphenol, 4-amino-2- (hydroxymethyl)phenol, 4-amino-2-(methoxymethyl)phenol, 4-amino-2-(amino- methyl)phenol, 4-amino-2-[( -hydroxyethyl)aminomethyl]phenol, 4-amino-2-fluorophenol and their addition salts with an acid.

Mention may be made, among ortho-aminophenols, by way of example, of

2- aminophenol, 2-amino-5-methylphenol, 2-amino-6-methylphenol, 5-acetamido- 2-aminophenol and their addition salts.

Mention may be made, among heterocyclic bases, by way of example, of pyridine derivatives, pyrimidine derivatives and pyrazole derivatives.

Mention may be made, among pyridine derivatives, of the compounds described, for example, in patents GB 1 026 978 and GB 1 153 196, such as 2,5-diaminopyridine, 2-[(4-methoxyphenyl)amino]-3-aminopyridine, 3,4-diaminopyridine and their addition salts.

Other pyridine oxidation bases of use in the dyeing method according to the invention are the 3-aminopyrazolo[1 ,5-a]pyridine oxidation bases or their addition salts described, for example, in patent application FR 2 801 308. Mention may be made, by way of example, of pyrazolo[1 ,5-a]pyridin-3-ylamine; 2-(acetylamino)pyrazolo[1 ,5- a]pyridin-3-ylamine; 2-(morpholin-4-yl)pyrazolo[1 ,5-a]pyridin-3-ylamine; 3-aminopyrazolo- [1 ,5-a]pyridine-2-carboxylic acid; 2-methoxypyrazolo[1 ,5-a]pyridin-3-ylamine; (3-aminopyrazolo[1 ,5-a]pyridin-7-yl)methanol; 2-(3-aminopyrazolo[1 ,5-a]pyridin-

5- yl)ethanol; 2-(3-aminopyrazolo[1 ,5-a]pyridin-7-yl)ethanol; (3-aminopyrazolo[1 ,5- a]pyridin-2-yl)methanol; 3,6-diaminopyrazolo[1 ,5-a]pyridine; 3,4-diaminopyrazolo[1 ,5- a]pyridine; pyrazolo[1 ,5-a]pyridine-3,7-diamine; 7-(morpholin-4-yl)pyrazolo[1 ,5-a]pyridin-

3- ylamine; pyrazolo[1 ,5-a]pyridine-3,5-diamine; 5-(morpholin-4-yl)pyrazolo[1 ,5-a]pyridin- 3-ylamine; 2-[(3-aminopyrazolo[1 ,5-a]pyridin-5-yl)(2-hydroxyethyl)amino]ethanol; 2-[(3-aminopyrazolo[1 ,5-a]pyridin-7-yl)(2-hydroxyethyl)amino]ethanol; 3-amino- pyrazolo[1 ,5-a]pyridin-5-ol; 3-aminopyrazolo[1 ,5-a]pyridin-4-ol; 3-aminopyrazolo[1 ,5- a]pyridin-6-ol; 3-aminopyrazolo[1 ,5-a]pyridin-7-ol; and their addition salts.

Mention may be made, among pyrimidine derivatives, of the compounds described, for example, in patents DE 2 359 399; JP 88-169571 ; JP 05-63124; EP 0 770 375 or patent application WO 96/15765, such as 2,4,5,6-tetraaminopyrimidine, 4-hydroxy-2,5,6- triaminopyrimidine, 2-hydroxy-4,5,6-triaminopyrimidine, 2,4-dihydroxy-5,6- diaminopyrimidine, 2,5,6-triaminopyrimidine and their addition salts and their tautomeric forms, when a tautomeric equilibrium exists.

Mention may be made, among pyrazole derivatives, of the compounds described in patents DE 3 843 892 and DE 4 133 957 and patent applications WO 94/08969, WO 94/08970, FR-A-2 733 749 and DE 195 43 988, such as 4,5-diamino- 1 -methylpyrazole, 4,5-diamino-1 -( -hydroxyethyl)pyrazole, 3,4-diaminopyrazole, 4,5-diamino-1 -(4'-chlorobenzyl)pyrazole, 4,5-diamino-1 ,3-dimethylpyrazole, 4,5-diamino- 3-methyl-1 -phenylpyrazole, 4,5-diamino-1 -methyl-3-phenylpyrazole, 4-amino-1 ,3- dimethyl-5-hydrazinopyrazole, 1 -benzyl-4,5-diamino-3-methylpyrazole, 4,5-diamino-3- (tert-butyl)-l -methylpyrazole, 4,5-diamino-1 -(tert-butyl)-3-methylpyrazole, 4,5-diamino-1 - ( -hydroxyethyl)-3-methylpyrazole, 4,5-diamino-1 -ethyl-3-methylpyrazole, 4,5-diamino-1 - ethyl-3-(4'-methoxyphenyl)pyrazole, 4,5-diamino-1 -ethyl-3-(hydroxymethyl)pyrazole, 4,5-diamino-3-hydroxymethyl-1 -methylpyrazole, 4,5-diamino-3-hydroxymethyl-1 - isopropylpyrazole, 4,5-diamino-3-methyl-1 -isopropylpyrazole, 4-amino-5-(2'- aminoethyl)amino-1 ,3-dimethylpyrazole, 3,4,5-triaminopyrazole, 1 -methyl-3,4,5- triaminopyrazole, 3,5-diamino-1 -methyl-4-(methylamino)pyrazole, 3,5-diamino-4-( - hydroxyethyl)amino-1 -methylpyrazole and their addition salts. Use may also be made of 4,5-diamino-1-( -methoxyethyl)pyrazole.

Use will preferably be made of a 4,5-diaminopyrazole and more preferably still of 4,5-diamino-1-(3-hydroxyethyl)pyrazole and/or one of its salts.

Mention may also be made, as pyrazole derivatives, of diamino-N,N- dihydropyrazolopyrazolones, in particular those described in application FR-A-2 886 136, such as the following compounds and their addition salts: 2,3-diamino-6,7-dihydro-1 H,5H- pyrazolo[1 ,2-a]pyrazol-1 -one, 2-amino-3-ethylamino-6,7-dihydro-1 H,5H-pyrazolo[1 ,2- a]pyrazol-1 -one, 2-amino-3-isopropylamino-6,7-dihydro-1 H,5H-pyrazolo[1 ,2-a]pyrazol-1 - one, 2-amino-3-(pyrrolidin-1 -yl)-6,7-dihydro-1 H,5H-pyrazolo[1 ,2-a]pyrazol-1 -one, 4,5- diamino-1 ,2-dimethyl-1 ,2-dihydropyrazol-3-one, 4,5-diamino-1 ,2-diethyl-1 ,2- dihydropyrazol-3-one, 4,5-diamino-1 ,2-di(2-hydroxyethyl)-1 ,2-dihydropyrazol-3-one, 2-amino-3-(2-hydroxyethyl)amino-6,7-dihydro-1 H,5H-pyrazolo[1 ,2-a]pyrazol-1 -one, 2-amino-3-dimethylamino-6,7-dihydro-1 H,5H-pyrazolo[1 ,2-a]pyrazol-1 -one, 2,3-diamino- 5,6,7,8-tetrahydro-1 H,6H-pyridazino[1 ,2-a]pyrazol-1 -one, 4-amino-1 ,2-diethyl-5- (pyrrolidin-1 -yl)-1 ,2-dihydropyrazol-3-one, 4-amino-5-[3-(dimethylamino)pyrrolidin-1 -yl]- 1 ,2-diethyl-1 ,2-dihydropyrazol-3-one or 2,3-diamino-6-hydroxy-6,7-dihydro-1 H,5H- pyrazolo[1 ,2-a]pyrazol-1 -one.

It will be preferable to use 2,3-diamino-6,7-dihydro-1 H,5H-pyrazolo[1 ,2-a]pyrazol-

1 -one and/or one of its salts.

Use will preferably be made, as heterocyclic bases, of 4,5-diamino-1 - (3-hydroxyethyl)pyrazole and/or 2,3-diamino-6,7-dihydro-1 H,5H-pyrazolo[1 ,2-a]pyrazol- 1 -one and/or one of their salts.

The cosmetic composition (B) used in the dyeing method according to the invention can optionally comprise one or more couplers advantageously chosen from those conventionally used for dyeing keratinous fibres.

Mention may in particular be made, among these couplers, of meta- phenylenediamines, meta-aminophenols, meta-diphenols, naphthalene couplers or heterocyclic couplers and their addition salts.

Mention may be made, by way of example, of 1 ,3-dihydroxybenzene,

1 ,3-dihydroxy-2-methylbenzene, 4-chloro-1 ,3-dihydroxybenzene, 2,4-diamino-1 -

( -hydroxyethyloxy)benzene, 2-amino-4-( -hydroxyethylamino)-1 -methoxybenzene,

1 ,3-diaminobenzene, 1 ,3-bis(2,4-diaminophenoxy)propane, 3-ureidoaniline, 3-ureido- 1 -dimethylaminobenzene, sesamol, 1 - -hydroxyethylamino-3,4-methylenedioxybenzene, oc-naphthol, 2-methyl-1 -naphthol, 6-hydroxyindole, 4-hydroxyindole, 4-hydroxy-N- methylindole, 2-amino-3-hydroxypyridine, 6-hydroxybenzomorpholine, 3,5-diamino-2,6- dimethoxypyridine, 1 -N-( -hydroxyethyl)amino-3,4-methylenedioxybenzene, 2,6-bis( - hydroxyethylamino)toluene, 6-hydroxyindoline, 2,6-dihydroxy-4-methylpyridine, 1 H-3- methylpyrazol-5-one, 1 -phenyl-3-methylpyrazol-5-one, 2,6-dimethylpyrazolo[1 ,5- b][1 ,2,4]triazole, 2,6-dimethyl[3,2-c][1 ,2,4]triazole, 6-methylpyrazolo[1 ,5-a]benzimidazole, their addition salts with an acid and their mixtures.

Generally, the addition salts of the oxidation bases and couplers which can be used in the context of the invention are chosen in particular from the addition salts with an acid, such as hydrochlorides, hydrobromides, sulfates, citrates, succinates, tartrates, lactates, tosylates, benzenesulfonates, phosphates and acetates.

The oxidation base or bases each advantageously represent from 0.0001 to 10% by weight, with respect to the total weight of the composition, and preferably from 0.005 to 5% by weight, with respect to the total weight of the composition.

The content of coupler(s), if it (they) is (are) present, each advantageously represents from 0.0001 to 10% by weight, with respect to the total weight of the composition, and preferably from 0.005 to 5% by weight, with respect to the total weight of the cosmetic composition (B).

As regards the direct dyes, the latter are more particularly chosen from ionic or nonionic entities, preferably cationic or nonionic entities. These direct dyes can be synthetic or of natural origin.

Mention may be made, as examples of suitable direct dyes, of azo, methine, carbonyl, azine, nitro(hetero)aryl or tri(hetero)arylmethane direct dyes, porphyrins, phthalocyanines and natural direct dyes, alone or as mixtures.

More particularly, azo dyes comprise an -N=N-functional group, the two nitrogen atoms of which are not simultaneously participants in a ring. However, it is not out of the question for one of the two nitrogen atoms of the -N=N- sequence to be a participant in a ring.

Dyes of the family of the methines are more particularly compounds comprising at least one sequence chosen from >C=C< and -N=C<, the two atoms of which are not simultaneously participants in a ring. However, it is specified that one of the nitrogen or carbon atoms of the sequences can be a participant in a ring. More particularly, the dyes of this family result from compounds of the following types: methine, azomethine, mono- and diarylmethane, indoamines (or diphenylamines), indophenols, indoanilines, carbocyanines, azacarbocyanines and their isomers, diazacarbocyanines and their isomers, tetraazacarbocyanines or hemicyanines.

As regards dyes of the family of the carbonyls, mention may be made, for example, of dyes chosen from acridone, benzoquinone, anthraquinone, naphthoquinone, benzanthrone, anthranthrone, pyranthrone, pyrazolanthrone, pyrimidinoanthrone, flavanthrone, indanthrone, flavone, (iso)violanthrone, isoindolinone, benzimidazolone, isoquinolinone, anthrapyridone, pyrazoloquinazolone, perinone, quinacridone, quinophthalone, indigoid, thioindigo, naphthalimide, anthrapyrimidine, diketopyrrolopyrrole or coumarin dyes.

As regards dyes of the family of the cyclic azines, mention may in particular be made of azine, xanthene, thioxanthene, fluorindine, acridine, (di)oxazine, (di)thiazine or pyronine dyes.

The nitro(hetero)aromatic dyes are more particularly nitrobenzene or nitropyridine direct dyes.

As regards the dyes of porphyrin or phthalocyanine type, use may be made of cationic or noncationic compounds optionally comprising one or more metals or metal ions, such as, for example, alkali and alkaline earth metals, zinc and silicon.

Mention may be made, as examples of direct dyes which are particularly suitable, of nitrobenzene dyes, azo, azomethine or methine direct dyes, azacarbocyanines, such as tetraazacarbocyanines (tetraazapentamethines), quinone and in particular anthraquinone, naphthoquinone or benzoquinone direct dyes, azine, xanthene, triarylmethane, indoamine or indigoid direct dyes, phthalocyanines, porphyrins and natural direct dyes, alone or as mixtures.

Mention may be made, among natural direct dyes which can be used according to the invention, of lawsone, juglone, alizarin, purpurin, carminic acid, kermesic acid, purpurogallin, protocatecuhaldehyde, indigo, isatin, curcumin, spinulosin, apigenidin or orceins. Use may also be made of extracts or decoctions comprising these natural dyes and in particular cataplasms or henna-based extracts.

When they are present, the direct dye or dyes more particularly represent from 0.0001 % to 10% by weight of the total weight of the composition and preferably from 0.005% to 5% by weight.

The cosmetic composition (B) employed in the dyeing method according to the invention can comprise dyes of one and/or other type(s). It can also result from the mixing of two dyeing compositions, one comprising the oxidation dye or dyes and the other the direct dye or dyes. Composition C

Finally, the method is carried out starting from a composition (C) comprising one or more oxidizing agents and one or more fatty substances. Oxidizing agent

More particularly, the oxidizing agent or agents are chosen from hydrogen peroxide, urea hydrogen peroxide, alkali metal bromates, peroxygenated salts, such as, for example, alkali metal or alkaline earth metal persulfates, perborates and percarbonates, or peracids and their precursors.

This oxidizing agent is advantageously composed of hydrogen peroxide, in particular in aqueous solution (aqueous hydrogen peroxide solution), the concentration of which can vary more particularly from 0.1 to 50% by weight, more preferably still from 0.5 to 20% by weight and better still from 1 to 15% by weight, with respect to the oxidizing composition (C).

Preferably, the formulation (mixture of the compositions (A), (B) and (C)) does not comprise peroxygenated salts.

The oxidizing composition (C) may or may not be aqueous. The aqueous composition is understood to mean a composition comprising more than 5% by weight of water, preferably with more than 10% by weight of water and more advantageously still more than 20% by weight of water.

Fatty substance

The cosmetic composition (C) comprises one or more fatty substances as described in the context of the anhydrous cosmetic composition (A).

Reference may thus be made to the corresponding passage of the description as regards the definitions and lists of the compounds which can be used in the context of the invention, and also for the preferred compounds which can be used as fatty substances. As regards the content of fatty substances in the cosmetic composition (C), this can advantageously represent at least 20% by weight and preferably from 20 to 70% by weight of the composition (C).

It should also be noted that the total content of fatty substances in the formulation, that is to say in the final ready-for-use formulation which is obtained after mixing the compositions (A), (B) and (C), represents at least 35% by weight of said formulation.

Preferably, the content of fatty substances in said formulation represents from 40 to 60% by weight. Solvent

Preferably, the oxidizing composition (C) is an aqueous composition.

It can also comprise one or more organic solvents.

Mention may for example be made, as organic solvent, of linear or branched C ₂ -C ₄ alkanols, such as ethanol and isopropanol, glycerol, polyols and polyol ethers, such as 2-butoxyethanol, propylene glycol, dipropylene glycol, propylene glycol monomethyl ether, diethylene glycol monoethyl ether and diethylene glycol monomethyl ether, aromatic alcohols or ethers, such as benzyl alcohol or phenoxyethanol, and their mixtures.

The solvent or solvents, if they are present, represent a content normally ranging from 1 to 40% by weight, with respect to the weight of the oxidizing composition (C), preferably from 5 to 30% by weight.

The oxidizing composition (C) can comprise one or more acidifying agents chosen in particular from those described above.

Normally, the pH of the oxidizing composition (C), when it is aqueous, is less than

7.

The oxidizing composition (C) can also include other ingredients conventionally employed in the field, such as, in particular, those described in detail above in the context of the compositions (A) and (B).

Finally, the oxidizing composition (C) is provided in various forms, such as, for example, a solution, an emulsion or a gel. Advantageously, the ratios by weight R1 of the amounts of compositions

[(A)+(B)]/(C) and R2 of the amounts of compositions (A)/(B) vary from 0.1 to 10 and preferably from 0.3 to 3, with the condition that the amount of fatty substances in the formulation represents at least 35% by weight, with respect to the weight of the formulation, preferably between 40 and 60% by weight.

The formulation resulting from the mixing of the abovementioned compositions (A), (B) and (C) is left in place on the fibers for a period of time generally of the order of from 1 minute to 1 hour, preferably from 5 minutes to 30 minutes.

The temperature during the method is conventionally between ambient temperature (from 15 to 25°C) and 80°C, preferably between ambient temperature and 60°C.

On conclusion of the treatment, human keratinous fibers are optionally rinsed with water and are optionally subjected to washing with a shampoo, followed by rinsing with water, before being dried or allowed to dry. Finally, the invention relates to a multicompartment device comprising a first compartment including the anhydrous cosmetic composition (A) comprising one or more fatty substances and one or more surfactants, a second compartment including a cosmetic composition (B) including the combination of the ammonium (bi)carbonate and the organic or inorganic base or bases or one of its/their salts and optionally one or more oxidation dyes, one or more direct dyes or their mixtures, and a third compartment including a cosmetic composition (C) comprising one or more oxidizing agents, the compositions of the compartments being intended to be mixed before application in order to give the formulation after mixing according to the invention, with the condition that the amount of fatty substances in this formulation represents at least 35% by weight, with respect to the weight of the formulation.

It is also possible to envisage a four-compartment device comprising a first compartment including the abovementioned anhydrous cosmetic composition (A), a second compartment including a cosmetic composition (B) including the combination of the ammonium (bi)carbonate and the organic or inorganic base or bases or one of its/their salts, a third compartment including one or more oxidation dyes, one or more direct dyes or their mixtures, and a fourth compartment including an anhydrous cosmetic composition (C), the compositions of the compartments being intended to be mixed before application in order to give the formulation after mixing according to the invention, with the condition that the amount of fatty substances in this formulation represents at least 35% by weight, with respect to the weight of the formulation.

The following examples serve to illustrate the invention without, however, exhibiting a limiting nature.

EXAMPLES

Example 1 : Lightening methods

The following compositions, in which the amounts are expressed in grams, are prepared.

Composition A (anhydrous gel)

A

Liquid petrolatum 64.5

2-Octyldodecanol 1 1.5

Distearyldimethylammonium-modified hectorite 3

Propylene carbonate 1

Oxyethylenated sorbitan monolaurate (4 EO) 1 1

Glycol distearate 8

Oxyethylenated lauryl alcohol 1 Composition B

Compositions C1 and C2 (oxidizing)

At the time of use, the following are mixed (by weight):

10 parts of the composition A

4 parts of the composition B

15 parts of either of the compositions C1 and C2.

The mixtures obtained (pH = 9.3) are subsequently applied to locks of natural Caucasian hair, height of tone 4.

The "mixture/lock" bath ratio is respectively 10/1 (g/g).

The leave-in time is 50 minutes at 27°C. At the end of this time, the locks are rinsed and then washed with Inoa Post shampoo (pH = 5.3 ± 0.3).

The color of the locks was evaluated in the CI E L* a* b* system using a Minolta Spectrophotometer CM2600D colorimeter.

As is shown in the table below, the mixture of the invention results in a better lightening than that of the prior art.

Calculation of the variation in the color (AEg _h *)

The rise in the coloration (AE _ab *) was evaluated in the CIE L* a* b* system. In this L* a* b* system, L* represents the intensity of the color, a* indicates the green/red color axis and b* indicates the blue/yellow color axis. The lower the value L*, the darker or more intense the color.

The value of AE _ab * was calculated from the L* a* b* values according to the following equation (i):

Δ E _ab * = (L* -L ₀ *) ² + (a* -a ₀ *) ² +(b*-b ₀ *) ² _(i)

The rise in the coloration (AE _ab *) was calculated on the locks of untreated hair (L ₀ *, a ₀ * and b ₀ *) and on locks of treated hair (L*, a* and b*).

The greater the value of AE _ab *, the better the variation in the color of the treated fibers.

Example 2: Dyeing method

The following dyeing composition, in which the amounts are expressed in grams, is prepared: Composition D

At the time of use, the following are mixed:

10 parts (by weight) of the composition A of example 1

4 parts of the composition D

15 parts of the composition C1 of example 1.

The mixture obtained (pH = 9) is subsequently applied to a lock of natural Caucasian hair comprising 90% of white hairs (NW).

The "mixture/lock" bath ratio is 10/1 (g/g).

The leave-in time is 50 minutes at 27°C.

At the end of this time, the lock is rinsed and then washed with Inoa Post shampoo (pH = 5.3 ± 0.3).

A light chestnut is obtained with good coverage of the white hairs.

The results are collated in the table below and are evaluated/calculated as in the case of example 1 .

L* a* b* AE*ab

Untreated NW hair 58.63 0.26 14.6 -

NW hair treated with a mixture of the

42.37 4.78 13.15 16.94 invention Example 3: Lightening methods

The following compositions, in which the amounts are expressed in grams, are prepared.

Composition A (anhydrous gel)

Composition B

Compositions C1 and C2 (oxidizing)

C1 C2

(Invention) (Comparative)

Oxyethylenated behenyl alcohol (10 EO) 6 6

Sorbitol 5 5

Liquid petrolatum 44 -

Distearyl ether 5 -

Sodium salicylate 0.035 0.035

Tetrasodium pyrophosphate hexahydrate 0.04 0.04 Etidronic acid, tetrasodium salt, as a 30%

0.2 0.2

aqueous solution

Phosphoric acid 0.1 0.1

Hydrogen peroxide as a 50% aqueous

solution (200-vol aqueous hydrogen 24 24

peroxide solution)

Water q.s. for 100 g q.s. for 100 g

At the time of use, the following are mixed (by weight):

10 parts of the composition A

4 parts of the composition B

- 15 parts of either of the compositions C1 and C2.

The mixtures obtained (pH = 9.2) are subsequently applied to locks of natural Caucasian hair, height of tone 4.

The "mixture/lock" bath ratio is respectively 10/1 (g/g).

The leave-in time is 50 minutes at 27°C.

At the end of this time, the locks are rinsed and then washed with Inoa Post shampoo (pH = 5.3 ± 0.3).

The color of the locks was evaluated in the CIE L ^* a ^* b ^* system using a Minolta Spectrophotometer CM2600D colorimeter.

As is shown in the table below, the mixture of the invention results in a better lightening than that of the prior art.

Example 4: Dyeing method

The following dyeing composition, in which the amounts are expressed in grams, is prepared: Composition D

At the time of use, the following are mixed:

10 parts (by weight) of the composition A of example 1

4 parts of the composition D

15 parts of the composition C1 of example 1.

The mixture obtained (pH = 9) is subsequently applied to a lock of natural Caucasian hair comprising 90% of white hairs (NW).

The "mixture/lock" bath ratio is 10/1 (g/g).

The leave-in time is 50 minutes at 27°C.

At the end of this time, the lock is rinsed and then washed with Inoa Post shampoo (pH = 5.3 ± 0.3).

A light chestnut is obtained with good coverage of the white hairs.

The results are collated in the table below and are evaluated/calculated as in the case of example 1 .

L* a* b* AE*ab

Untreated NW hair 58.63 0.26 14.6 -

NW hair treated with a mixture of the

34.63 4.57 16.09 24.43 invention