WO2011076646A2 - Agent for dyeing and/or bleaching keratin fibres, comprising an inverse emulsion comprising an oxidizing agent - Google Patents

Abstract

The present invention relates to an agent for dyeing and/or bleaching keratin fibres, comprising: -an oil-in-water direct emulsion (A1) or a water-in-oil inverse emulsion (A2) comprising one or more oils not containing any carboxylic acid functions; one or more surfactants; one or more basifying agents, and -a water-in-oil inverse emulsion (B) comprising from 20% to 70% by weight of one or more oils not containing any carboxylic acid functions; one or more surfactants. The invention also relates to a dyeing or lightening process using the said agent. Another subject of the invention is two-compartment devices containing, in one, a direct emulsion (A1) or inverse emulsion (A2), and, in the other, an inverse emulsion (B) comprising one or more oxidizing agents.

Description

Agent for dyeing and/or bleaching keratin fibres, comprising an inverse emulsion comprising an oxidizing agent

The present invention relates to an agent in two or more parts, intended for dyeing and/or bleaching keratin fibres, in particular human keratin fibres such as the hair.

Among the methods for dyeing human keratin fibres, such as the hair, mention may be made of oxidation dyeing or permanent dyeing. More particularly, this dyeing method uses one or more oxidation dye precursors, usually one or more oxidation bases optionally combined with one or more couplers.

In general, oxidation bases are chosen from ortho- or para- phenylenediamines, ortho- or para-aminophenols and heterocyclic compounds. These oxidation bases are colourless or weakly coloured compounds, which, when combined with oxidizing products, can give access to coloured species via a process of oxidative condensation.

The shades obtained with these oxidation bases are often varied by combining them with one or more couplers, these couplers being chosen especially from aromatic meta-diamines, meta-aminophenols, meta- diphenols and certain heterocyclic compounds, such as indole compounds.

The variety of molecules used as oxidation bases and couplers allows a wide range of colours to be obtained.

Direct dyeing or semi-permanent dyeing is also known. The process conventionally used in direct dyeing consists in applying to the keratin fibres direct dyes, which are coloured and colouring molecules that have affinity for the fibres, in leaving them on for a time to allow the molecules to penetrate, by diffusion, into the fibre, and then in rinsing them off.

The direct dyes generally used are chosen from nitrobenzene, anthraquinone, nitropyridine, azo, methine, azomethine, xanthene, acridine, azine and triarylmethane direct dyes.

This type of process does not require the use of an oxidizing agent to develop the colouration. However, it is not excluded to use one in order to obtain, along with the colouration, a lightening effect. Such a process is then referred to as direct dyeing or semi-permanent dyeing under lightening conditions.

Processes of permanent or semi-permanent dyeing under lightening conditions thus consist in using, along with the dye composition, an aqueous composition comprising at least one oxidizing agent, under alkaline pH conditions in the vast majority of cases. The role of this oxidizing agent is to degrade the melanin of the hair, which, depending on the nature of the oxidizing agent present, leads to more or less pronounced lightening of the fibres. Thus, for relatively weak lightening, the oxidizing agent is generally hydrogen peroxide. When more substantial lightening is desired, peroxygenated salts, for instance persulfates, are usually used in the presence of hydrogen peroxide.

In order to improve the performance of processes for dyeing and/or bleaching human keratin fibres, and to limit the inconveniences associated with the use of alkaline agents and oxidizing agents, it has been proposed to use in dye compositions a substantial amount of one or more fatty substances especially such as oils.

However, the incorporation into these compositions of a sufficient amount of oil proves to be problematic in terms of stability. These formulations are thermodynannically unstable, heat-sensitive and their viscosity changes over time, all the more so when it is sought to increase their oil content.

There is a need to have satisfactory efficacy for lightening and dyeing products, especially in terms of lightening power or dyeing strength and/or selectivity, while at the same time reducing the harmful effects associated with the simultaneous presence of alkaline agents and oxidizing agents such as hydrogen peroxide, especially while reducing the degradation of the keratin fibres and reducing the inconveniences associated with the odour of the alkaline agents used, such as ammonia and amines.

It is thus sought to improve the effects of the alkaline agents and/or oxidizing agents while at the same time having maximum dyeing or lightening efficacy on keratin fibres.

This aim and others are achieved by the present invention, one subject of which is thus an agent for bleaching/dyeing the hair, comprising (a) an oil-in-water O/W direct emulsion (A1 ) comprising from 5% to 40% by weight, relative to the weight of the direct emulsion, of one or more oils not containing any carboxylic acid functions; one or more surfactants; one or more basifying agents, and (b) a water-in-oil inverse emulsion (B) comprising one or more oxidizing agents, from 20% to 70% by weight, relative to the weight of the inverse emulsion, of one or more oils not containing any carboxylic acid functions; one or more surfactants; the total amount of oil(s) in the agent after mixing the direct emulsion (A) and the inverse emulsion (B) being greater than 20% by weight relative to the weight of the mixture.

A subject of the present invention is also an agent for dyeing and/or bleaching keratin fibres, comprising:

- a first water-in-oil emulsion (A2) comprising one or more basifying agents, water, one or more surfactants, and from 30% to 70% by weight, relative to the total weight of emulsion (A), of one or more oils not containing any carboxylic acid functions, and

- a second water-in-oil emulsion (B) comprising one or more oxidizing agents, water, one or more surfactants, and from 30% to 70% by weight, relative to the total weight of the emulsion (B), of one or more oils not containing any carboxylic acid functions.

The invention also relates to a process for treating human keratin fibres using the agent of the invention.

A subject of the invention is similarly a multi-compartment device comprising, in a first compartment, the direct emulsion (A1 ) or inverse emulsion (A2), and, in a second compartment, the inverse emulsion (B) containing one or more oxidizing agents.

When the agent according to the invention is intended for dyeing keratin fibres, the direct emulsion (A1 ) or inverse emulsion (A2) also comprises one or more oxidation dyes and/or one or more direct dyes.

Conversely, when the agent according to the invention is intended solely for bleaching keratin fibres, emulsions (A1 ), (A2) and (B) do not comprise any direct dyes or any oxidation dyes (bases and couplers) or, if they are present, their total content does not exceed 0.005% by weight relative to the weight of each composition. Specifically, at such a content, only the composition would be dyed, i.e. no dyeing effect would be observed on the keratin fibres.

Emulsions (A1 ), respectively (A2), and (B) of the dyeing and/or bleaching agent according to the invention are stable, and their viscosity changes little or not at all over time.

In addition, when it is intended for dyeing keratin fibres, the agent according to the invention is particularly effective especially as regards the uptake of the dyes onto the fibres, the power and chromaticity of the dyeing obtained, and also as regards the dyeing selectivity along the same fibre or between fibres that are differently sensitized.

When it is intended for bleaching keratin fibres, the agent according to the invention has lightening performance equivalent to or even greater than that obtained with the existing compositions, especially with those based on ammonium hydroxide.

The agent according to the invention also has the advantage of limiting the aggressive odours during its preparation or its application to the fibres.

Other characteristics and advantages of the invention will emerge more clearly on reading the description and the examples that follow.

In the text hereinbelow, and unless otherwise indicated, the limits of a range of values are included in that limit.

The human keratin fibres treated via the process according to the invention are preferably the hair.

The inverse emulsion (water-in-oil) and direct emulsion (oil-in-water) according to the invention are true emulsions, and should be distinguished from microemulsions, which are thermodynamically stable systems, unlike true emulsions.

Emulsions (A1 ), (A2) and (B) may be prepared via standard processes for preparing inverse or direct emulsions, which are well known to those skilled in the art.

The direct emulsion (A1 ) is an oil-in-water emulsion that preferably contains from 10% to 30% of one or more oils not containing any carboxylic acid functions.

The emulsion (A2) contains from 40% to 65% by weight of one or more oils not containing any carboxylic acid functions, relative to the total weight of the emulsion (A).

The emulsion (B) is in the form of an inverse emulsion of water-in-oil type comprising an aqueous phase and an oily phase, the amount of water possibly ranging from 5% to 70% and better still from 10% to 50% relative to the total weight of the emulsion. In another variant, the aqueous phase comprising water and the compounds that are soluble in water at room temperature and atmospheric pressure represents from 10% to 70% and better still from 15% to 50% of the total weight of the emulsion (B).

The inverse emulsion (B) is a water-in-oil emulsion that preferably comprises from 30% to 65% and preferably 40% to 65% of one or more oils not containing any carboxylic acid functions.

In the direct emulsion (A1 ), the inverse emulsion (A2) and the inverse emulsion (B) that are useful in the agent of the invention, the size of the droplets of the dispersed phase of the emulsion is preferably between 10 nm and 100 μιτι and more preferentially between 200 nm and 50 μιτι.

The term "size of the droplets of the dispersed phase" denotes the mean diameter D(3.2) of the droplets, which may be measured especially using a laser granulometer.

For the purposes of the present invention, the term "oils" means an organic compound that is insoluble in water at ordinary temperature (25°C) and at atmospheric pressure (760 mmHg; i.e. 1013.105 Pa), i.e. it has a water solubility of less than 5% by weight, preferably 1 % and even more preferentially 0.1 %. These compounds have in their structure at least one hydrocarbon-based chain comprising at least six carbon atoms or a sequence of at least two siloxane groups. In addition, oils are soluble in organic solvents under the same temperature and pressure conditions, for instance chloroform, ethanol or benzene. Furthermore, oils are liquid at ordinary temperature (25°C) and at atmospheric pressure (760 mmHg; i.e. 1013.105 Pa).

"Oil not containing any carboxylic acid functions" means an oil containing no -COOH groups and no -COO- groups.

The oil(s) not containing any carboxylic acid functions used in the direct emulsion (A1 ), the inverse emulsion (A2) and/or the inverse emulsion (B) may be identical or different, and may be chosen especially from hydrocarbons, non-silicone oils of animal, plant, mineral or synthetic origin, fatty alcohols, fatty acid esters and/or fatty alcohol esters, and silicones, and mixtures thereof.

It is pointed out that, for the purposes of the present invention, the fatty alcohols more particularly contain one or more linear or branched, saturated or unsaturated hydrocarbon-based groups, comprising 6 to 30 carbon atoms, which are optionally substituted, in particular with one or more (in particular 1 to 4) hydroxyl groups. If they are unsaturated, these compounds may comprise one to three conjugated or unconjugated carbon-carbon double bonds.

More particularly, the liquid hydrocarbons are chosen from:

- linear or branched, optionally cyclic, C6-C16 lower alkanes. Examples that may be mentioned include hexane, undecane, dodecane, tridecane, and isoparaffins, for instance isohexadecane, isododecane and isodecane, - linear or branched hydrocarbons of mineral, animal or synthetic origin, containing more than 16 carbon atoms, such as liquid paraffins, petroleum jelly, liquid petroleum jelly, polydecenes and hydrogenated polyisobutenes such as Parleam®, and squalane.

In one preferred variant, the liquid hydrocarbon(s) are chosen from liquid paraffins and liquid petroleum jelly.

Preferably, the silicones are chosen from liquid polydialkylsiloxanes, especially liquid polydimethylsiloxanes (PDMS) and liquid polyorganosiloxanes comprising at least one aryl group.

These silicones may also be organomodified. The organomodified silicones that may be used in accordance with the invention are liquid silicones as defined previously, comprising in their structure one or more organofunctional groups attached via a hydrocarbon-based group.

Organopolysiloxanes are defined in greater detail in Walter Noll's Chemistry and Technology of Silicones (1968), Academic Press. They may be volatile or non-volatile.

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

(i) cyclic polydialkylsiloxanes containing from 3 to 7 and preferably 4 to 5 silicon atoms. These are, for example, octamethylcyclotetrasiloxane sold in particular under the name Volatile Silicone® 7207 by Union Carbide or Silbione® 70045 V2 by Rhodia, decamethylcyclopentasiloxane sold under the name Volatile Silicone® 7158 by Union Carbide, Silbione® 70045 V5 by Rhodia, and dodecamethylcyclopentasiloxane sold under the name Silsoft 1217 by Momentive Performance Materials, and mixtures thereof.

Mention may also be made of cyclocopolymers of the dimethylsiloxane/methylalkylsiloxane type, such as Volatile Silicone® FZ 3109 sold by the company Union Carbide, of formula:

D" - D' D" - D'—

CH₃ ' ' CH₃

with D'': — Si - O— with D': - Si - O—

I I

CH₃ C₈H₁₇

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

(ii) linear volatile polydialkylsiloxanes containing 2 to 9 silicon atoms and having a viscosity of less than or equal to 5x10^"6 m²/s at 25°C. An example is decamethyltetrasiloxane sold in particular under the name SH 200 by the company Toray Silicone. Silicones belonging to 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. The viscosity of the silicones is measured, for example, at 25°C according to ASTM standard 445 Appendix C.

Non-volatile polydialkylsiloxanes may also be used.

These silicones are more particularly chosen from polydialkylsiloxanes, among which mention may be made mainly of polydimethylsiloxanes containing trimethylsilyl end groups.

Among these polydialkylsiloxanes, mention may be made, in a nonlimiting manner, of the following commercial products:

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

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

- the oils of the 200 series from the company Dow Corning, such as DC200 with a viscosity of 60 000 mm²/s;

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

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

Among the silicones containing aryl groups are polydiarylsiloxanes, especially polydiphenylsiloxanes and polyalkylarylsiloxanes. Examples that may be mentioned include the products sold under the following names:

• the Silbione® oils of the 70 641 series from Rhodia;

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

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

· the silicones of the PK series from Bayer, such as the product

PK20; • certain oils of the SF series from General Electric, such as SF 1023, SF 1 154, SF 1250 and SF 1265.

The liquid fatty esters are preferably liquid esters of saturated or unsaturated, linear or branched C1-C26 aliphatic mono- or polyacids and of saturated or unsaturated, linear or branched C1-C26 mono- or polyalcohols, the total number of carbon atoms in the esters being greater than or equal to 10.

Preferably, for the esters of monoalcohols, at least one from among the alcohol and the acid from which the esters of the invention are derived is branched.

Among the monoesters of monoacids and of monoalcohols, mention may be made of ethyl palmitate, isopropyl palmitate, alkyl myristates such as isopropyl myristate or ethyl myristate, isocetyl stearate, 2-ethylhexyl isononanoate, isodecyl neopentanoate and isostearyl neopentanoate.

Esters of C₄-C22 dicarboxylic or tricarboxylic acids and of C1-C22 alcohols and esters of mono-, di- or tricarboxylic acids and of C₄-C26 di-, tri- , tetra- or pentahydroxy alcohols may also be used.

The following may especially be mentioned: diethyl sebacate; diisopropyl sebacate; bis(2-ethylhexyl) sebacate; diisopropyl adipate; di-n- propyl adipate; dioctyl adipate; bis(2-ethylhexyl) adipate; diisostearyl adipate; bis(2-ethylhexyl) maleate; triisopropyl citrate; triisocetyl citrate; triisostearyl citrate; glyceryl trilactate; glyceryl trioctanoate; trioctyldodecyl citrate; trioleyl citrate; neopentyl glycol diheptanoate; diethylene glycol diisononanoate.

The emulsion may also comprise, as liquid fatty ester, C6-C30 and preferably C12-C22 fatty acid esters and diesters of sugars. It is recalled that the term "sugar" means oxygenous hydrocarbon-based compounds that contain several alcohol functions, with or without aldehyde or ketone functions, and that comprise at least 4 carbon atoms. These sugars may be monosaccharides, oligosaccharides or polysaccharides.

Examples of suitable sugars that may be mentioned include sucrose (or saccharose), glucose, galactose, ribose, fucose, maltose, fructose, mannose, arabinose, xylose and lactose, and derivatives thereof, especially alkyl derivatives, such as methyl derivatives, for instance methylglucose.

The sugar esters of fatty acids may be chosen especially from the group comprising the esters or mixtures of esters of sugars described previously and of linear or branched, saturated or unsaturated C6-C30 and preferably C12-C22 fatty acids. If they are unsaturated, these compounds may comprise one to three conjugated or non-conjugated carbon-carbon double bonds.

The esters according to this variant may also be chosen from mono-, di- , tri-, tetraesters and polyesters, and mixtures thereof.

These esters may be chosen, for example, from oleates, laurates, palmitates, myristates, behenates, cocoates, stearates, linoleates, linolenates, caprates and arachidonates, or mixtures thereof such as, especially, oleo-palmitate, oleo-stearate and palmito-stearate mixed esters.

Monoesters and diesters and especially sucrose, glucose or methyl- glucose mono- or dioleates, stearates, behenates, oleopalmitates, linoleates, linolenates and oleostearates are more particularly used.

An example that may be mentioned is the product sold under the name Glucate® DO by the company Amerchol, which is a methylglucose dioleate.

Finally, natural or synthetic esters of mono-, di- or triacids with glycerol may also be used.

Among these, mention may be made of plant oils.

As oils of plant origin or synthetic triglycerides that may be used in the emulsions (A1 ), (A2) or (B), examples that may be mentioned include:

- triglyceride oils of plant or synthetic origin, such as liquid fatty acid triglycerides containing from 6 to 30 carbon atoms, for instance heptanoic or octanoic acid triglycerides, or alternatively, for example, sunflower oil, corn oil, soybean oil, marrow oil, grapeseed oil, sesame seed oil, hazelnut oil, apricot oil, macadamia oil, arara oil, castor oil, avocado oil, caprylic/capric acid triglycerides, for instance those sold by the company Stearineries Dubois or those sold under the names Miglyol® 810, 812 and 818 by the company Dynamit Nobel, jojoba oil and shea butter oil.

Liquid fatty esters derived from monoalcohols will preferably be used as esters according to the invention. These fatty alcohols may be unsaturated.

Isopropyl myristate and isopropyl palmitate are particularly preferred.

Preferably, the liquid fatty alcohols of the invention comprise from 8 to 30 carbon atoms.

These liquid unsaturated fatty alcohols contain in their structure at least one double or triple bond. Preferably, the fatty alcohols bear in their structure one or more double bonds. When several double bonds are present, there are preferably 2 or 3 of them, and they may be conjugated or unconjugated.

These fatty alcohols may be linear or branched.

They may optionally comprise in their structure at least one aromatic or non-aromatic ring. They are preferably acyclic.

More particularly, the liquid unsaturated fatty alcohols are chosen from oleyl alcohol, linolenyl alcohol, linolenyl alcohol and undecylenyl alcohol.

Oleyl alcohol is most particularly preferred.

The liquid fatty alcohols may also be branched saturated fatty alcohols. More particularly, the liquid branched saturated fatty alcohols of the invention are chosen from isostearyl alcohol and octyldodecanol.

Preferably, the oil(s) used in the direct emulsion (A1 ), the inverse emulsion (A2) and/or the inverse emulsion (B) do not comprise any oxyalkylene units or any glycerol units.

Preferably, the oil(s) used in the emulsions (A1 ), (A2) and/or (B) are non-silicone.

According to one particular embodiment, the oil(s) used in the direct emulsion (A1 ), the inverse emulsion (A2) and/or the inverse emulsion (B), which may be identical or different, are chosen from liquid paraffins, liquid petroleum jelly, polydecenes, liquid fatty acid esters and/or liquid fatty alcohol esters, and liquid fatty alcohols, and mixtures thereof, and even more preferably from liquid paraffins, liquid petroleum jelly, polydecenes and liquid fatty alcohols. Preferably, the oil(s) are chosen from liquid paraffins and liquid petroleum jelly, and also mixtures thereof. The total amount of oil(s) not containing any carboxylic acid functions in the mixture of the direct emulsion (A1 ), the inverse emulsion (A2) and the inverse emulsion (B) represents at least 25% by weight and preferably at least 30% by weight relative to the total weight of the mixture of these two emulsions. The direct emulsion (A1 ) or inverse emulsion (A2) that is useful in the invention comprises a basifying agent. This agent may be chosen from mineral or organic or hybrid alkaline agents, or mixtures thereof.

The mineral basifying agent(s) are preferably chosen from aqueous ammonia, alkali metal carbonates or bicarbonates such as sodium or potassium carbonates or bicarbonates, sodium hydroxide and potassium hydroxide, and mixtures thereof.

The organic basifying agent(s) are preferably chosen from organic amines whose pKb at 25°C is less than 12, preferably less than 10 and even more advantageously less than 6. It should be noted that it is the pKb corresponding to the function of highest basicity.

Hybrid compounds that may be mentioned include the salts of the amines mentioned previously with acids such as carbonic acid or hydrochloric acid.

The organic basifying agent(s) are chosen, for example, from alkanolamines, oxyethylenated and/or oxypropylenated ethylenediamines, amino acids and the compounds of formula (I) below:

Rx Rz

W - N

Ry ^x Rt _(|) in which W is a C1 -C6 alkylene residue optionally substituted with a hydroxyl group or a C1 -C6 alkyl radical; Rx, Ry, Rz and Rt, which may be identical or different, represent a hydrogen atom or a C1 -C6 alkyl, C1 -C6 hydroxyalkyl or C1 -C6 aminoalkyl radical.

Examples of such amines that may be mentioned include 1 ,3- diaminopropane, 1 ,3-diamino-2-propanol, spermine and spermidine.

The term "alkanolamine" means an organic amine comprising a primary, secondary or tertiary amine function, and one or more linear or branched Ci -Cs alkyl groups bearing one or more hydroxyl radicals.

Alkanolamines such as mono-, di- or tri- alkanolamines comprising from one to three identical or different Ci -C₄ hydroxyalkyl radicals are in particular suitable for performing the invention.

Examples that may be mentioned include monoethanolamine, diethanolamine, triethanolamine, monoisopropanolamine, diisopropanol- amine, N-dimethylaminoethanolamine, 2-amino-2-methyl-1 -propanol, triiso- propanolamine, 2-amino-2-methyl-1 ,3-propanediol, 3-amino-1 ,2- propanediol, 3-dimethylamino-1 ,2-propanediol and tris(hydroxymethylamino)methane.

More particularly, the amino acids that may be used are of natural or synthetic origin, in L, D or racemic form, and comprise at least one acid function chosen more particularly from carboxylic acid, sulfonic acid, phosphonic acid and phosphoric acid functions. The amino acids may be in their neutral or ionic form.

As amino acids that may be used in the present invention, mention may be made especially 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.

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

Such basic amino acids are preferably chosen from those corresponding to formula (II) below:

NH₀

/

R— CH₂— CH\

C C0₂H in which R denotes a roup chosen from:

i₂NH₂ ; -(CH₂)₂NHCONH₂

-(CH₂)₂NH C— NH₂

NH

The compounds corresponding to formula (II) are histidine, lysine, arginine, ornithine and citrulline.

The organic amine may also be chosen from organic amines of heterocyclic type. Besides histidine that has already been mentioned in the amino acids, mention may be made in particular of pyridine, piperidine, imidazole, triazole, tetrazole and benzimidazole.

The organic amine may also be chosen from amino acid dipeptides. As amino acid dipeptides that may be used in the present invention, mention may be made especially of carnosine, anserine and baleine.

The organic amine may also be chosen from compounds comprising a guanidine function. As amines of this type that may be used in the present invention, besides arginine that has already been mentioned as an amino acid, mention may be made especially 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.

Mention may be made in particular of the use of guanidine carbonate or monoethanolamine hydrochloride as hybrid compounds.

The emulsion of the invention preferably contains one or more alkanolamines and/or one or more basic amino acids.

According to one particular embodiment, the direct emulsion (A1 ) or inverse emulsion (A2) contains as alkaline agents at least one organic amine, preferably at least one alkanolamine. When the emulsion contains several alkaline agents including an alkanolamine and aqueous ammonia or a salt thereof, the organic amine(s) are preferably in weight majority relative to the amount of ammonia.

According to one preferred embodiment of the present invention, when the direct emulsion (A1 ) or inverse emulsion (A2) contains aqueous ammonia, it also contains one or more alkanolamines, and the weight amount of alkanolamine(s) in the direct emulsion (A1 ) or inverse emulsion (A2) is greater than the weight amount of ammonia in this same composition.

According to another preferred embodiment of the present invention, the direct emulsion (A1 ) or inverse emulsion (A2) does not contain any aqueous ammonia.

Generally, the direct emulsion (A1 ) or inverse emulsion (A2) has a content of basifying agent(s) ranging from 0.1 % to 40% by weight and preferably from 0.5% to 20% by weight relative to the total weight of this composition.

Preferably, the direct emulsion (A1 ) and/or the aqueous phase of the direct emulsion (A1 ) has a pH of greater than or equal to 8 and more preferentially pH ranging from 8.5 to 1 1 .5.

This pH may also be adjusted to the desired value by using, in addition to the basifying agent(s), one or more acidifying agents.

Among the acidifying agents, examples that may be mentioned include mineral or organic acids, for instance hydrochloric acid, orthophosphoric acid or sulfuric acid, carboxylic acids, for instance acetic acid, tartaric acid, citric acid or lactic acid, and sulfonic acids.

According to one variant, the direct emulsion that is useful in the present invention comprises one or more oxidation dyes and/or one or more direct dyes.

The oxidation dyes are generally chosen from oxidation bases and couplers. By way of example, the oxidation bases are chosen from para- phenylenediamines, bis(phenyl)alkylenediamines, para-aminophenols, ortho-aminophenols and heterocyclic bases, and the addition salts thereof.

Among the para-phenylenediamines, examples that may be mentioned include para-phenylenediamine, para-tolylenediamine, 2-chloro-para- phenylenediamine, 2,3-dimethyl-para-phenylenediamine, 2,6-dimethyl- para-phenylenediamine, 2,6-diethyl-para-phenylenediamine, 2,5-dimethyl- para-phenylenediamine, Ν,Ν-dimethyl-para-phenylenediamine, N,N- 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-ethyl-N-( -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 and 3-hydroxy-1 -(4'-aminophenyl)pyrrolidine, and the addition salts thereof with an acid.

Among the para-phenylenediamines mentioned above, para- phenylenediamine, para-tolylenediamine, 2-isopropyl-para-phenyl- enediamine, 2- -hydroxyethyl-para-phenylenediamine, 2- -hydroxy- ethyloxy-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 and 2- -acetylaminoethyloxy-para-phenylenediamine, and the addition salts thereof with an acid, are particularly preferred.

Among the bis(phenyl)alkylenediamines that may be mentioned, for example, are N,N'-bis( -hydroxyethyl)-N,N'-bis(4'-aminophenyl)-1 ,3- diaminopropanol, N,N'-bis( -hydroxyethyl)-N,N'-bis(4'-aminophenyl)- ethylenediamine, N,N'-bis(4-aminophenyl)tetramethylenediamine, Ν,Ν'- bis( -hydroxyethyl)-N,N'-bis(4-aminophenyl)tetramethylenediamine, Ν,Ν'- bis(4-methylaminophenyl)tetramethylenediamine, N,N'-bis(ethyl)-N,N'- bis(4'-amino-3'-methylphenyl)ethylenediamine and 1 ,8-bis(2,5-diamino- phenoxy)-3,6-dioxaoctane, and the addition salts thereof.

Among the para-aminophenols that may be mentioned, for example, are para-aminophenol, 4-amino-3-methylphenol, 4-amino-3-fluorophenol, 4-amino-3-chlorophenol, 4-amino-3-hydroxymethylphenol, 4-amino-2- methylphenol, 4-amino-2-hydroxymethylphenol, 4-amino-2-methoxymethyl- phenol, 4-amino-2-aminomethylphenol, 4-amino-2-( -hydroxyethylamino- methyl)phenol and 4-amino-2-fluorophenol, and the addition salts thereof with an acid.

Among the ortho-aminophenols that may be mentioned, for example, are 2-aminophenol, 2-amino-5-methylphenol, 2-amino-6-methylphenol and 5-acetamido-2-aminophenol, and the addition salts thereof.

Among the heterocyclic bases that may be mentioned, for example, are pyridine derivatives, pyrimidine derivatives and pyrazole derivatives.

Among the pyridine derivatives that may be mentioned are the compounds described, for example, in patents GB 1 026 978 and GB 1 153 196, for instance 2,5-diaminopyridine, 2-(4-methoxyphenyl)- amino-3-aminopyridine and 3,4-diaminopyridine, and the addition salts thereof.

Other pyridine oxidation bases that are useful in the present invention are the 3-aminopyrazolo[1 ,5-a]pyridine oxidation bases or addition salts thereof described, for example, in patent application FR 2 801 308. Examples that may be mentioned include pyrazolo[1 ,5-a]pyrid-3-ylamine, 2-acetylaminopyrazolo[1 ,5-a]pyrid-3-ylamine, 2-morpholin-4-ylpyrazolo[1 ,5- a]pyrid-3-ylamine, 3-aminopyrazolo[1 ,5-a]pyridine-2-carboxylic acid,

2- methoxypyrazolo[1 ,5-a]pyrid-3-ylamine, (3-aminopyrazolo[1 ,5-a]pyrid-7- yl)methanol, 2-(3-aminopyrazolo[1 ,5-a]pyrid-5-yl)ethanol, 2-(3-amino- pyrazolo[1 ,5-a]pyrid-7-yl)ethanol, (3-aminopyrazolo[1 ,5-a]pyrid-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-ylpyrazolo-

[1 ,5-a]pyrid-3-ylamine, pyrazolo[1 ,5-a]pyridine-3,5-diamine, 5-morpholin-4- ylpyrazolo[1 ,5-a]pyrid-3-ylamine, 2-[(3-aminopyrazolo[1 ,5-a]pyrid-5-yl)(2- hydroxyethyl)amino]ethanol, 2-[(3-aminopyrazolo[1 ,5-a]pyrid-7-yl)(2- hydroxyethyl)amino]ethanol, 3-aminopyrazolo[1 ,5-a]pyridin-5-ol, 3-amino- pyrazolo[1 ,5-a]pyridin-4-ol, 3-aminopyrazolo[1 ,5-a]pyridin-6-ol and

3- aminopyrazolo[1 ,5-a]pyridin-7-ol, and the addition salts thereof.

Among the pyrimidine derivatives that may be mentioned are the compounds described, for example, in patents DE 2 359 399; JP 88-169 571 ; JP 05-63124; EP 0 770 375 or patent application WO 96/15765, for instance 2,4,5,6-tetraaminopyrimidine, 4-hydroxy-2,5,6-triaminopyrimidine, 2-hydroxy-4,5,6-triaminopyrimidine, 2,4-dihydroxy-5,6-diaminopyrimidine and 2,5,6-triaminopyrimidine, and the addition salts thereof, and the tautomeric forms thereof, when a tautomeric equilibrium exists.

Among the pyrazole derivatives that may be mentioned are 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, for instance 4,5-diamino-1 -methylpyrazole, 4,5-diamino-1 - ( -hydroxyethyl)pyrazole, 3,4-diaminopyrazole, 4,5-diamino-1 -(4'-chloro- benzyl)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-1 -methylpyrazole, 4,5-diamino-1 -tert-butyl-3-methyl- pyrazole, 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-hydroxymethylpyrazole, 4,5-diamino-3-hydroxy- methyl-1 -methylpyrazole, 4,5-diamino-3-hydroxymethyl-1 -isopropyl- pyrazole, 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-methylaminopyrazole and 3, 5-diamino-4-( -hydroxyethyl)amino-1 -methylpyrazole, and the addition salts thereof. 4,5-Diamino-1-( -methoxyethyl)pyrazole may also be used.

A 4,5-diaminopyrazole will preferably be used, and even more preferentially 4,5-diamino-1-( -hydroxyethyl)pyrazole and/or a salt thereof.

Pyrazoles that may also be mentioned include diamino-N,N- dihydropyrazolopyrazolones and especially those described in patent application FR-A-2 886 136, such as the following compounds and the addition salts thereof: 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-dimethylannino-pyrrolidin-1 -yl)-1 ,2-diethyl-1 ,2-dihydropyrazol-3-one, 2,3- diamino-6-hydroxy-6,7-dihydro-1 H,5H-pyrazolo[1 ,2-a]pyrazol-1 -one.

2,3-Diamino-6,7-dihydro-1 H,5H-pyrazolo[1 ,2-a]pyrazol-1 -one and/or a salt thereof will preferably be used.

4,5-Diamino-1-( -hydroxyethyl)pyrazole and/or 2,3-diamino-6,7- dihydro-1 H,5H-pyrazolo[1 ,2-a]pyrazol-1 -one and/or a salt thereof will preferentially be used as heterocyclic bases.

Among the couplers that may be used, mention may be made especially of meta-phenylenediamines, meta-aminophenols, meta- diphenols, naphthalene-based couplers and heterocyclic couplers, and also the addition salts thereof.

Mention may be made, for 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-diamino- phenoxy)propane, 3-ureidoaniline, 3-ureido-1 -dimethylaminobenzene, sesamol, 1 - -hydroxyethylamino-3,4-methylenedioxybenzene, a-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 and 6-methylpyrazolo[1 ,5-a]- benzimidazole, the addition salts thereof with an acid, and mixtures thereof.

The addition salts of the oxidation bases and couplers are especially chosen from the addition salts with an acid such as the hydrochlorides, hydrobromides, sulfates, citrates, succinates, tartrates, lactates, tosylates, benzenesulfonates, phosphates and acetates.

The oxidation base(s) each advantageously represent from 0.0001 % to 10% by weight relative to the total weight of the composition, and preferably from 0.005% to 5% by weight relative to the total weight of the emulsion.

The content of coupler(s), if they are present, each advantageously represent from 0.0001 % to 10% by weight relative to the total weight of the emulsion, and preferably from 0.005% to 5% by weight relative to the total weight of the emulsion.

The direct dyes that may be used are, for example, synthetic or natural dyes, chosen from ionic or nonionic species, preferably cationic or nonionic species.

Examples of particularly suitable direct dyes that may be mentioned include nitrobenzene dyes; azo direct dyes; azomethine direct dyes; methine direct dyes; azacarbocyanin direct dyes, for instance tetraazacarbocyanins (tetraazapentamethines); quinone and in particular anthraquinone, naphthoquinone or benzoquinone direct dyes; azine; xanthene; triarylmethane; indoamine; indigoid; phthalocyanins, porphyrins and natural direct dyes, alone or as mixtures. In particular, mention may be made of direct dyes from among: azo; methine; carbonyl; azine; nitro (hetero)aryl; tri(hetero)arylmethane; porphyrin; phthalocyanin, and natural direct dyes, alone or as mixtures.

Among the benzenic direct dyes that may be used according to the invention, mention may be made in a non-limiting manner of the following compounds:

- 1 ,4-diamino-2-nitrobenzene,

- 1 -amino-2-nitro-4- -hydroxyethylaminobenzene

- 1 -amino-2-nitro-4-bis( -hydroxyethyl)aminobenzene

- 1 ,4-bis( -hydroxyethylamino)-2-nitrobenzene

- 1 - -hydroxyethylamino-2-nitro-4-bis( -hydroxyethylamino)benzene - 1 - -hydroxyethylamino-2-nitro-4-aminobenzene

- 1 - -hydroxyethylamino-2-nitro-4-(ethyl)( -hydroxy- ethyl)aminobenzene

- 1 -amino-3-methyl-4- -hydroxyethylamino-6-nitrobenzene

- 1 -amino-2-nitro-4- -hydroxyethylamino-5-chlorobenzene

- 1 ,2-diamino-4-nitrobenzene

- 1 -amino-2- -hydroxyethylamino-5-nitrobenzene

- 1 ,2-bis( -hydroxyethylamino)-4-nitrobenzene

- 1 -amino-2-tris(hydroxymethyl)methylamino-5-nitrobenzene

- 1 -hydroxy-2-amino-5-nitrobenzene

- 1 -hydroxy-2-amino-4-nitrobenzene

- 1 -hydroxy-3-nitro-4-aminobenzene

- 1 -hydroxy-2-amino-4,6-dinitrobenzene - 1 - -hydroxyethyloxy-2- -hydroxyethylannino-5-nitrobenzene

- 1 -methoxy-2- -hydroxyethylannino-5-nitrobenzene

- 1 - -hydroxyethyloxy-3-methylamino-4-nitrobenzene

- 1 - ,y-dihydroxypropyloxy-3-nnethylannino-4-nitrobenzene

- 1 - -hydroxyethylannino-4- ,Y-dihydroxypropyloxy-2-nitrobenzene

- 1 - ,Y-dihydroxypropylamino-4-trifluoronnethyl-2-nitrobenzene

- 1 - -hydroxyethylamino-4-trifluoromethyl-2-nitrobenzene

- 1 - -hydroxyethylamino-3-methyl-2-nitrobenzene

- 1 - -aminoethylamino-5-methoxy-2-nitrobenzene

- 1 -hydroxy-2-chloro-6-ethylamino-4-nitrobenzene

- 1 -hydroxy-2-chloro-6-amino-4-nitrobenzene

- 1 -hydroxy-6-bis( -hydroxyethyl)annino-3-nitrobenzene

- 1 - -hydroxyethylamino-2-nitrobenzene

- 1 -hydroxy-4- -hydroxyethylannino-3-nitrobenzene.

Among the azo, azomethine, methine and tetraazapentamethine direct dyes that may be used according to the invention, mention may be made of the cationic dyes described in patent applications WO 95/15144, WO 95/01772 and EP 714 954; FR 2 189 006, FR 2 285 851 , FR 2 140 205, EP 1 378 544 and EP 1 674 073.

Among these dyes, the following compounds are preferred:

Among the azo direct dyes that may also be mentioned are the following dyes, described in the Colour Index International, 3rd edition:

- Disperse Red 17

- Basic Red 22 - Basic Red 76

- Basic Yellow 57

- Basic Brown 16

- Basic Brown 17

- Disperse Black 9.

Mention may also be made of 1 -(4'-aminodiphenylazo)-2-methyl-4- bis( -hydroxyethyl)aminobenzene.

Among the quinone direct dyes that may be mentioned are the following dyes:

- Disperse Red 15

- Solvent Violet 13

- Disperse Violet 1

- Disperse Violet 4

- Disperse Blue 1

- Disperse Violet 8

- Disperse Blue 3

- Disperse Red 1 1

- Disperse Blue 7

- Basic Blue 22

- Disperse Violet 15

- Basic Blue 99

and also the following compounds:

- 1 -N-methylmorpholiniumpropylamino-4-hydroxyanthraquinone

- 1 -aminopropylamino-4-methylaminoanthraquinone

- 1 -aminopropylaminoanthraquinone

- δ-β-hydroxyethyl-l ,4-diaminoanthraquinone

- 2-aminoethylaminoanthraquinone

- 1 ,4-bis( ,Y-dihydroxypropylamino)anthraquinone.

Among the azine dyes that may be mentioned are the following compounds:

- Basic Blue 17

- Basic Red 2.

Among the triarylmethane dyes that may be used according to the invention, mention may be made of the following compounds:

- Basic Green 1

- Basic Violet 3

- Basic Violet 14 - Basic Blue 7

- Basic Blue 26.

Among the indoamine dyes that may be used according to the invention, mention may be made of the following compounds:

2- -hydroxyethylamino-5-[bis( -4'-hydroxyethyl)amino]anilino-1 ,4- benzoquinone

2- -hydroxyethylamino-5-(2'-methoxy-4'-amino)anilino-1 ,4- benzoquinone

3- N-(2'-chloro-4'-hydroxy)phenylacetylamino-6-methoxy-1 ,4- benzoquinone imine

3-N-(3'-chloro-4'-methylamino)phenylureido-6-methyl-1 ,4- benzoquinone imine

3-[4'-N-(ethyl,carbamylmethyl)amino]phenylureido-6-methyl-1 ,4- benzoquinone imine.

Among the dyes of tetraazapentamethine type that may be used according to the invention, mention may be made of the following

X^" represents an anion preferably chosen from chloride, iodide, methyl sulfate, ethyl sulfate, acetate and perchlorate.

Among the natural direct dyes that may be used according to the invention, mention may be made of lawsone, juglone, alizarin, purpurin, carminic acid, kermesic acid, purpurogallin, protocatechaldehyde, indigo, isatin, curcumin, spinulosin, apigenidin, haematoxylin, haematin, brasilin, brasilein and orceins. It is also possible to use extracts or decoctions containing these natural dyes and especially henna-based poultices or extracts.

The direct dyes may be monochromophoric dyes (i.e. comprising only one dye) or polychromophoric, preferably di- or trichromophoric; the chromophores possibly being identical or different, and from the same or different chemical families. It should be noted that a polychromophoric dye comprises several radicals each derived from a molecule that absorbs in the visible region between 400 and 800 nm. Furthermore, this absorbance of the dye does not require any prior oxidation thereof, or combination with any other chemical species.

As examples of such dyes, reference may be made especially to patent applications EP 1 637 566, EP 1 619 221 , EP 1 634 926, EP 1 619 220, EP 1 672 033, EP 1 671 954, EP 1 671 955, EP 1 679 312, EP 1 671 951 , EP 167 952, EP 167 971 , WO 06/063 866, WO 06/063 867, WO 06/063 868, WO 06/063 869, EP 1 408 919, EP 1 377 264, EP 1 377 262, EP 1 377 261 , EP 1 377 263, EP 1 399 425, EP 1 399 1 17, EP 1 416 909, EP 1 399 1 16 and EP 1 671 560.

It is also possible to use the cationic direct dyes mentioned in patent applications: EP 1 006 153, which describes dyes comprising two chromophores of anthraquinone type connected via a linker of cationic type; EP 1 433 472, EP 1 433 474, EP 1 433 471 and EP 1 433 473, which describe identical or different dichromophoric dyes, connected via a cationic or non-cationic linker, and also EP 6 291 333, which especially describes dyes comprising three chromophores, one of them being an anthraquinone chromophore, to which are attached two chromophores of azo or diazacarbocyanin type or an isomer thereof.

When they are present, the direct dye(s) more particularly represent from 0.0001 % to 10% by weight and preferably from 0.005% to 5% by weight relative to the total weight of the emulsion.

The direct emulsion (A1 ) or inverse emulsion (A2) and the inverse emulsion (B) comprise one or more surfactants. The surfactants that are useful may be anionic, cationic, amphoteric or nonionic.

The surfactant(s) that may be used in each of the direct (A1 ) or inverse (A2) and (B) emulsions are preferably chosen from nonionic surfactants and anionic surfactants, and preferably from nonionic surfactants.

The anionic surfactants are more especially chosen from the salts (in particular alkali metal salts, especially sodium salts, ammonium salts, amino salts such as amino alcohol salts or alkaline-earth metal salts such as magnesium salts) of the following compounds:

- alkyl sulfates, alkyl ether sulfates, alkylamido ether sulfates, alkylaryl polyether sulfates, monoglyceride sulfates;

- alkylsulfonates, alkylamidesulfonates, alkylarylsulfonates, a-olefin sulfonates, paraffin sulfonates;

- alkyl phosphates, alkyl ether phosphates;

- alkylsulfosuccinates, alkyl ether sulfosuccinates, alkylamidesulfosuccinat.es; alkylsulfosuccinates;

- alkylsulfoacetates;

- acylsarcosinates; acylisethionates and N-acyltaurates;

- salts of fatty acids such as oleic acid, ricinoleic acid, palmitic acid or stearic acid, coconut oil acid or hydrogenated coconut oil acid;

- alkyl-D-galactoside uronic acid salts;

- acyllactylates;

- salts of polyoxyalkylenated alkyl ether carboxylic acids, of polyoxyalkylenated alkylaryl ether carboxylic acids or of polyoxyalkylenated alkylamido ether carboxylic acids, in particular those containing from 2 to 50 ethylene oxide groups;

- and mixtures thereof.

It should be noted that the alkyl or acyl radical of these various compounds advantageously contains from 6 to 24 carbon atoms and preferably from 8 to 24 carbon atoms, and the aryl radical preferably denotes a phenyl or benzyl group.

The nonionic surfactants are more particularly chosen from monooxyalkylenated or polyoxyalkylenated, monoglycerolated or polyglycerolated nonionic surfactants. The oxyalkylene units are more particularly oxyethylene or oxypropylene units, or a combination thereof, preferably oxyethylene units.

Examples of oxyalkylenated nonionic surfactants that may be mentioned include:

- oxyalkylenated (C8-C2₄)alkylphenols,

- saturated or unsaturated, linear or branched, oxyalkylenated C8-C30 alcohols,

- saturated or unsaturated, linear or branched, oxyalkylenated C8-C30 amides,

- esters of saturated or unsaturated, linear or branched, C8-C30 acids and of polyethylene glycols,

- polyoxyethylenated esters of saturated or unsaturated, linear or branched, C8-C30 acids and of sorbitol,

- saturated or unsaturated, oxyethylenated plant oils,

- condensates of ethylene oxide and/or of propylene oxide,

- and mixtures thereof.

These surfactants contain a number of moles of ethylene oxide and/or of propylene oxide of between 1 and 100 and preferably between 2 and 50.

Advantageously, the nonionic surfactants do not comprise any oxypropylene units.

In accordance with one preferred embodiment of the invention, the oxyalkylenated nonionic surfactants are chosen from oxyethylenated Cs- C30 alcohols, and esters of C8-C30 acids and of polyethylene glycols.

As examples of monoglycerolated or polyglycerolated nonionic surfactants, monoglycerolated or polyglycerolated Cs-C₄o alcohols are preferably used.

In particular, the monoglycerolated or polyglycerolated Cs-C₄o alcohols correspond to the following formula:

RO-[CH₂-CH(CH₂OH)-O]_m-H

in which R represents a linear or branched Cs-C₄o and preferably C8-C30 alkyl or alkenyl radical, and m represents a number ranging from 1 to 30 and preferably from 1 to 10.

As examples of compounds that are suitable in the context of the invention, mention may be made of lauryl alcohol containing 4 mol of glycerol (INCI name: Polyglyceryl-4 Lauryl Ether), lauryl alcohol containing 1 .5 mol of glycerol, oleyl alcohol containing 4 mol of glycerol (INCI name: Polyglyceryl-4 Oleyl Ether), oleyl alcohol containing 2 mol of glycerol (INCI name: Polyglyceryl-2 Oleyl Ether), cetearyl alcohol containing 2 mol of glycerol, cetearyl alcohol containing 6 mol of glycerol, oleocetyl alcohol containing 6 mol of glycerol, and octadecanol containing 6 mol of glycerol.

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

Among the monoglycerolated or polyglycerolated alcohols, it is more particularly preferred to use the Cs Cio alcohol containing 1 mol of glycerol, the C10 C12 alcohol containing 1 mol of glycerol and the C12 alcohol containing 1 .5 mol of glycerol.

According to one preferred embodiment of the present invention, the direct emulsion (A1 ) or inverse emulsion (A2) contains one or more nonionic surfactants.

In one variant of this embodiment, emulsion (A1 ) contains one or more nonionic surfactants with an HLB of greater than or equal to 8.

According to an embodiment that is also preferred, the emulsion (B) contains one or more nonionic surfactants.

In one variant of this embodiment, the emulsion (B) contains one or more nonionic surfactants with an HLB of less than 8.

According to the invention, the direct emulsion (A1 ) or inverse emulsion (A2) preferably contains from 1 % to 20% by weight, more preferentially from 1 % to 15% by weight and better still from 2% to 10% by weight of surfactant(s), relative to the total weight of the emulsion (A).

Similarly, the inverse emulsion (B) preferably contains from 1 % to 20% by weight, more preferentially from 1 % to 15% by weight and better still from 2% to 10% by weight of surfactant(s) relative to the total weight of the emulsion (B).

According to the present invention, the inverse emulsion (B) comprises one or more oxidizing agents.

This oxidizing agent may be chosen from the oxidizing agents conventionally used for the bleaching and oxidation dyeing of keratin fibres, and among which mention may be made of hydrogen peroxide, urea peroxide, alkali metal bromates or ferricyanides, and peroxygenated salts, for instance persulfates, perborates and percarbonates of alkali metals or alkaline-earth metals such as sodium, potassium or magnesium. One or more redox enzymes such as laccases, peroxidases and 2-electron oxidoreductases (such as uricase), optionally in the presence of the respective donor or cofactor thereof, may also be used as oxidizing agent.

The use of hydrogen peroxide is particularly preferred. This agent may advantageously be employed as an aqueous solution (aqueous hydrogen peroxide solution) whose concentration may range, more particularly, from 0.1 % to 50% by weight, even more preferentially from 0.5% to 20% by weight and better still from 1 % to 15% by weight relative to the total weight of the emulsion (B).

Depending on the desired degree of bleaching, the oxidizing agent may also comprise one or more compounds preferably chosen from peroxygenated salts.

Preferably, the pH of the inverse emulsion (B) and/or of the aqueous phase of the inverse emulsion (B) is less than 7. This pH may be adjusted to the desired value by using one or more basifying agents, which may be chosen especially from those described previously.

The direct emulsion (A1 ) or inverse emulsions (A2) and (B) that are useful in the invention may comprise one or more fumed silicas.

Fumed silicas may be obtained by high-temperature hydrolysis of a volatile silicon compound in an oxhydric flame, producing a finely divided silica. This process makes it possible especially to obtain hydrophilic silicas having a large number of silanol groups at their surface. Such hydrophilic silicas are sold, for example, under the names Aerosil 130®, Aerosil 200®, Aerosil 255®, Aerosil 300® and Aerosil 380® by the company Degussa, and Cab-O-Sil HS-5®, Cab-O-Sil EH-5®, Cab-O-Sil LM-130®, Cab-O-Sil MS-55® and Cab-O-Sil M-5® by the company Cabot.

It is possible to chemically modify the surface of the silica via chemical reaction in order to reduce the number of silanol groups. Silanol groups may especially be substituted with hydrophobic groups: a hydrophobic silica is then obtained.

The hydrophobic groups may be:

- trimethylsiloxyl groups, which are obtained especially by treating fumed silica in the presence of hexamethyldisilazane. Silicas thus treated are known as "Silica silylate" according to the CTFA (6th edition, 1995). They are sold, for example, under the references Aerosil R812® by the company Degussa and Cab-O-Sil TS-530® by the company Cabot. - dimethylsilyloxyl or polydimethylsiloxane groups, which are especially obtained by treating fumed silica in the presence of polydimethylsiloxane or dimethyldichlorosilane. Silicas thus treated are known as "Silica dimethyl silylate" according to the CTFA (6th edition, 1995). They are sold, for example, under the references Aerosil R972® and Aerosil R974® by the company Degussa, and Cab-O-Sil TS-610® and Cab-O-Sil TS-720® by the company Cabot.

The fumed silica preferably has a particle size that may be nanometric to micrometric, for example ranging from about 5 to 200 nanometres.

When it is present, the fumed silica represents from 1 % to 30% by weight relative to the weight of each of the emulsions.

The emulsions that are useful in the present invention may also comprise one or more thickeners.

These thickeners may be chosen from fatty acid amides (coconut acid diethanolamide or monoethanolamide, oxyethylenated alkyi ether carboxylic acid monoethanolamide), polymeric thickeners such as cellulose-based thickeners (hydroxyethylcellulose, hydroxypropylcellulose, carboxymethylcellulose), guar gum and derivatives thereof (hydroxypropylguar), and clays, and especially bentonites and hectorites, and derivatives thereof.

The content of thickener(s), if they are present, usually ranges from 0.01 % to 20% by weight and preferably from 0.1 % to 5% by weight relative to the weight of each of the emulsions.

The emulsions optionally comprise one or more organic solvents.

Examples of organic solvents that may be mentioned include linear or branched and preferably saturated monoalcohols, comprising 2 to 6 carbon atoms, such as ethanol or isopropanol; aromatic alcohols such as benzyl alcohol or phenylethyl alcohol; polyols containing more than two hydroxyl functions, such as glycerol; polyol ethers, for instance ethylene glycol monomethyl, monoethyl or monobutyl ether, propylene glycol or ethers thereof, for instance propylene glycol monomethyl ether; and also diethylene glycol alkyi ethers, especially Ci-C₄ alkyi ethers, for instance diethylene glycol monoethyl ether or monobutyl ether, alone or as a mixture.

The organic solvents, when they are present, generally represent between 1 % and 40% by weight relative to the total weight of each of the emulsions, and preferably between 5% and 30% by weight relative to the total weight of each of the emulsions.

The emulsions may be in various forms, such as in the form of liquids, milks or creams, or in any other form that is suitable for dyeing keratin fibres, and especially human hair.

Preferably, they are in the form of a milk or a cream.

In one variant of the invention, the agent of the invention is formed only from the two emulsions (A1 ) and (B) or (A2) and (B).

A subject of the present invention is also a process for dyeing and/or bleaching keratin fibres, comprising the application to the said keratin fibres of the agent as described above.

According to the invention, the agent applied to keratin fibres results from the mixing of the direct emulsion (A1 ) or inverse emulsion (A2) and the inverse emulsion (B), this mixing being performed either before application to keratin fibres (extemporaneous preparation) or directly on the keratin fibres (successive application to the fibres of the direct emulsion (A1 ) or inverse emulsion (A2) and of the inverse emulsion (B) without intermediate rinsing).

Thus, according to a first variant of the process according to the invention, the direct emulsion (A1 ) or inverse emulsion (A2) and the inverse emulsion (B) are applied to the wet or dry keratin fibres, successively and without intermediate rinsing.

According to a second variant of the process according to the invention, a composition obtained by extemporaneously mixing, before application, the direct emulsion (A1 ) or inverse emulsion (A2) and the inverse emulsion (B) is applied to the wet or dry keratin fibres.

In this case, the interval between the mixing of the direct emulsion (A1 ) or inverse emulsion (A2) and of the inverse emulsion (B) and the application of the mixture to the hair preferably does not exceed 30 minutes, preferably 10 minutes and even more preferably five minutes.

Independently of the variant used, the weight ratio of the amount of the direct emulsion (A1 ) or inverse emulsion (A2) used to the amount of the inverse emulsion (B) used may range from 0.2 to 3 and preferably from 0.3 to 1 .

In addition, independently of the variant used, the mixture present on the fibres (resulting either from the extemporaneous mixing of the direct emulsion (A1 ) or inverse emulsion (A2) and of the inverse emulsion (B) or from the successive application thereof) is left on for a time generally from about one minute to one hour and preferably from five minutes to 30 minutes.

The temperature during the process is, conventionally, preferably between room temperature (between 15 and 25°C) and 80°C and preferably between room temperature and 60°C.

After the treatment, the keratin fibres are optionally rinsed with water, optionally undergo washing with a shampoo followed by rinsing with water, and are then dried or left to dry.

Finally, a subject of the invention is also a multi-compartment dyeing and/or bleaching device or "kit", comprising a first compartment containing a direct emulsion (A1 ) or inverse emulsion (A2), and also a second compartment containing an inverse emulsion (B), the direct emulsion (A1 ) or inverse emulsion (A2) and the inverse emulsion and (B) being as described above.

This device may also comprise one or more compositions for washing and/or conditioning keratin fibres, which are intended to be applied before and/or after the dyeing and/or bleaching treatment according to the invention.

The examples that follow serve to illustrate the invention without, however, being limiting in nature.

EXAMPLES

EXAMPLE 1

The following dye composition was prepared (in the table below, amounts are expressed in grams):

The dye composition A1 in the form of a direct emulsion corresponds to a dye composition in accordance with the present invention.

Dye composition (g%) A1

Ascorbic acid 0.25

1 -Methyl-2,5-diaminobenzene 0.17

1 -Hydroxy-4-aminobenzene 0.2

Resorcinol 0.1

1 -Methyl-2-hydroxy-4- -hydroxyethylaminobenzene 0.25

1 -Methyl-2-hydroxy-4-aminobenzene 0.28

Liquid paraffin 20

C16 C18 cetylstearyl alcohol (30/70) 8

Cetylstearyl alcohol 33 OE 3

Sodium stannate hexahydrate 0.04

Oxyethylenated rapeseed acid amide (4 OE) 1 .5

Vitamin E 0.1

Glycerol 1

Monoethanolamine 4

Demineralized water qs 100

The oxidizing composition C2 corresponds to a composition (B) in the form of an inverse emulsion in accordance with the present invention.

Oxidizing composition (g%) C2

Liquid petroleum jelly 51 .5

Octyldodecanol 9

Distearyldimethylammonium-modified hectorite 1 .3

Propylene carbonate 0.45

Oleth-3 ^{(1 )} 6

Propylene glycol 2

Ethanol 3

Hexylene glycol 1

Dipropylene glycol 1

POE/POP/POE (Poloxamer 184) 13 Hydrogen peroxide 6

Sodium stannate hexahydrate 0.04

Diethylenetriaminepentaacetic acid 0.015

Tetrasodium pyrophosphate decahydrate 0.03

Phosphoric acid qs pH = 3

Water qs 100

At the time of use, one part by weight of composition A1 is mixed with one part by weight of composition C2.

The mixture is then applied to locks of natural hair containing 90% white hairs. After a leave-on time of 30 minutes at room temperature (23°C), the hair is rinsed, washed with a standard shampoo and then dried. A mahogany blonde coloration is obtained.

EXAMPLE 2

The oxidation dyeing agent below was prepared (in tables below, the amounts are expressed in grams):

Inverse emulsion (A2), comprising a basifyinq agent and oxidation dyes

Ingredients Amount (g)

Liquid petroleum jelly 51 .5

Octyldodecanol 9

Distearyldimethylammonium-modified hectorite 1 .3

Propylene carbonate 0.45

Oleth-10 4.3

Propylene glycol 2

Ethanol 3

Hexylene glycol 1

Dipropylene glycol 1

Monoethanolamine 4

POE/POP/POE (Poloxamer 184) 13

Ascorbic acid 0.25 para-Phenylenediamine 0.03

Resorcinol 0.04

1 -Hydroxy-3-aminobenzene 0.002

1- -Hydroxyethyloxy-2,4-diaminobenzene

0.0003 dihydrochloride

N,N-Bis(2-hydroxyethyl)-p-phenylenediamine sulfate

0.006 monohydrate Water qs 100

Inverse emulsion (B) comprising an oxidizing agent:

At the time of use, one part by weight of the inverse emulsion (A2) is mixed with one part by weight of composition (B).

The mixture is then applied to locks of natural hair containing 90% white hairs. After a leave-on time of 30 minutes at room temperature (23°C), the hair is rinsed, washed with a standard shampoo and then dried. An ash- golden very light blonde coloration is obtained.

Claims

1. Agent for dyeing and/or bleaching keratin fibres, comprising:

- an oil-in-water direct emulsion (A1 ) comprising from 5% to 40% by weight, relative to the weight of the direct emulsion, of one or more oils not containing any carboxylic acid functions; one or more surfactants; one or more basifying agents, and

- a water-in-oil inverse emulsion (B) comprising one or more oxidizing agents, from 20% to 70% by weight, relative to the total weight of the inverse emulsion, of one or more oils not containing any carboxylic acid functions; one or more surfactants;

the total amount of oil(s) in the agent after mixing the direct emulsion (A1 ) and the inverse emulsion (B) being greater than 20% by weight relative to the weight of the mixture.

2. Agent for dyeing and/or bleaching keratin fibres, comprising:

- a water-in-oil inverse emulsion (A2) comprising one or more basifying agents, water, one or more surfactants, and from 30% to 70% by weight, relative to the total weight of emulsion (A2), of one or more oils not containing any carboxylic acid functions, and

- a water-in-oil inverse emulsion (B) comprising one or more oxidizing agents, water, one or more surfactants, and from 30% to 70% by weight, relative to the total weight of the emulsion (B), of one or more oils not containing any carboxylic acid functions.

3. Agent according to Claim 1 or 2, characterized in that the basifying agent is chosen from aqueous ammonia, alkali metal carbonates, alkanolamines and derivatives thereof, sodium hydroxide, potassium hydroxide, and the compounds of formula (I) below:

Rx Rz

W N

Ry ^x Rt

(I) in which W is a C1-C6 alkylene residue optionally substituted with a hydroxyl group or a C1-C6 alkyl radical; Rx, Ry, Rz and Rt, which may be identical or different, represent a hydrogen atom or a C1-C6 alkyl, C1-C6 hydroxyalkyl or C1-C6 aminoalkyl radical, and is preferably chosen from alkanolamines.

4. Agent according to any one of the preceding claims, characterized in that the oxidizing agent is chosen from hydrogen peroxide, urea peroxide, alkali metal bromates or ferricyanides, peroxygenated salts, for instance alkali metal or alkaline-earth metal persulfates, perborates and percarbonates, and redox enzymes such as laccases, peroxidases and 2-electron oxidoreductases, optionally in the presence of the respective donor or cofactor thereof; and is preferably hydrogen peroxide.

5. Agent according to any one of the preceding Claims 1 , 3 and 4, characterized in that the emulsion (A1 ) contains from 10% to 30% by weight of one or more oils not containing any carboxylic acid functions, relative to the total weight of the emulsion (A1 ).

6. Agent according to any one of the preceding Claims 2, 3 and 4, characterized in that the inverse emulsion (A2) contains from 40% to 65% by weight of one or more oils not containing any carboxylic acid functions, relative to the total weight of the emulsion (A2).

7. Agent according to any one of the preceding claims, characterized in that the emulsion (B) contains from 30% to 65% and preferably 40% to 65% by weight of one or more oils not containing any carboxylic acid functions, relative to the total weight of the emulsion (B).

8. Agent according to any one of the preceding Claims 1 and 3 to 7, characterized in that the total amount of oil(s) not containing any carboxylic acid functions in the mixture of the direct emulsion (A1 ) and of the inverse emulsion (B) represents at least 25% by weight and preferably at least 30% by weight relative to the total weight of the mixture of these two emulsions.

9. Agent according to any one of the preceding claims, characterized in that the oil(s) not containing any carboxylic acid functions are chosen from hydrocarbons, non-silicone oils of animal, plant, mineral or synthetic origin, fatty alcohols, fatty acid esters and/or fatty alcohol esters, and silicones, and mixtures thereof; preferably from liquid paraffins, liquid petroleum jelly, polydecenes, liquid fatty acid esters and/or liquid fatty alcohol esters, and liquid fatty alcohols, and mixtures thereof; and more preferably from liquid petroleum jelly, polydecenes and liquid fatty alcohols, and better still from liquid paraffin and liquid petroleum jelly, and also mixtures thereof.

10. Agent according to any one of the preceding claims, characterized in that the direct emulsion (A1 ) or inverse emulsion (A2) and the emulsion (B) contain from 1 % to 20% by weight of one or more surfactants relative to the total weight of each emulsion.

11. Agent according to the preceding claim, characterized in that the said surfactants are chosen from oxyalkylenated nonionic surfactants.

12. Agent according to any one of the preceding claims, characterized in that the direct emulsion (A1 ) or inverse emulsion (A2) comprises one or more oxidation dyes chosen from oxidation bases, optionally combined with one or more couplers and/or one or more direct dyes.

13. Agent according to any one of the preceding Claims 1 to 1 1 , characterized in that the direct emulsion (A1 ) or inverse emulsion (A2) and the inverse emulsion (B) do not comprise any direct dyes or any oxidation dyes (bases and couplers), or, if they are present, the total content does not exceed 0.005% by weight relative to the total weight of each emulsion.

14. Process for dyeing and/or bleaching keratin fibres, comprising the application to the wet or dry fibres, successively and without intermediate rinsing, of the direct emulsion (A1 ) or inverse emulsion (A2) and the inverse emulsion (B) as defined in any one of the preceding claims.

15. Process for dyeing and/or bleaching keratin fibres, comprising the application to the wet or dry fibres of a composition obtained by extemporaneous mixing of the direct emulsion (A1 ) or inverse emulsion (A2) and the inverse emulsion (B) as defined in any one of Claims 1 to 13.

16. Multi-compartment device or "kit" for dyeing and/or bleaching, comprising a first compartment containing a direct emulsion (A1 ) or inverse emulsion (A2), and also a second compartment containing an inverse emulsion (B), the direct emulsion (A1 ) or inverse emulsion (A2) and the inverse emulsion (B) being as defined in any one of Claims 1 to 13.