WO2016097126A1

WO2016097126A1 - Composition for dyeing or lightening keratin fibres, in the form of a microemulsion based on particular oil(s), hydrotropic solvents and surfactant(s)

Info

Publication number: WO2016097126A1
Application number: PCT/EP2015/080194
Authority: WO
Inventors: Boris Lalleman; Alain Lagrange
Original assignee: L'oreal
Priority date: 2014-12-18
Filing date: 2015-12-17
Publication date: 2016-06-23
Also published as: FR3030228A1; FR3030228B1

Abstract

The present invention relates to a composition (A) for dyeing or lightening keratin fibres, in the form of a microemulsion comprising: i) at least water; ii) at least one non-carbonyl-based oil; iii) at least one solvent with a Hansen parameter δH of greater than 0 and less than 16 MPa^½, the total content of solvents(s) with a Hansen parameter δH of greater than 0 and less than 16 MPa^½ being less than or equal to 35% by weight relative to the weight of the composition; iv) at least one surfactant; and v) at least one compound chosen from: a. colouring agents chosen from direct dyes and oxidation dyes, and/or mixtures thereof; and b. oxidizing agents, c. basifying agents, d. and mixtures thereof. The present invention also relates to a process for dyeing or lightening keratin fibres, comprising the application of a composition A, optionally preceded by mixing with a composition B comprising at least one oxidizing agent, and also to a multi-compartment device and to a ready-to-use composition resulting from the mixing of compositions (A) and (B). The composition according to the invention makes it possible to lighten or to dye keratin fibres strongly, efficiently and homogeneously while at the same time being stable and easy to apply.

Description

COMPOSITION FOR DYEING OR LIGHTENING KERATIN FIBRES, IN THE FORM OF A MICROEMULSION BASED ON PARTICULAR OIL(S), HYDROTROPIC SOLVENTS AND SURFACTANT(S)

The present invention relates to a composition (A) for dyeing or lightening keratin fibres, such as the hair, in the form of a microemulsion comprising i) at least water; ii) at least one non-carbonyl-based oil iii) at least one liquid organic compound with a Hansen solubility parameter value δΗ of greater than 0 and less than 16 MPa½, the total content of liquid organic compound(s) with a Hansen solubility parameter value δΗ of greater than 0 and less than 16 MPa½ ranging from 0.5% to 35% by weight relative to the weight of the composition; iv) at least one surfactant; and v) at least one compound chosen from:

a) colouring agents chosen from direct dyes and oxidation dyes, and/or mixtures thereof;

b) chemical oxidizing agents;

c) basifying agents;

d) and mixtures thereof. A subject of this invention is also a process for dyeing or lightening keratin fibres using such a composition, and also a multi-compartment device comprising said composition.

Two major methods for dyeing human keratin fibres, and in particular the hair, are known.

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 compositions comprising one or more oxidation dyes, or 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 rise via a process of oxidative condensation to coloured species, which remain trapped within the fibre.

Oxidation dyeing processes thus consist in using with these dye compositions a composition comprising at least one oxidizing agent, generally hydrogen peroxide, under alkaline pH conditions in the vast majority of cases. The role of this oxidizing agent is to reveal the colouring, via an oxidative condensation reaction between the oxidation dyes.

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.

These bases and couplers are colourless or weakly coloured compounds, which, when combined with oxidizing products, may give rise to coloured compounds by a process of oxidative condensation. The variety of molecules used as oxidation bases and couplers allows a wide range of colours to be obtained.

This type of oxidation dyeing makes it possible to obtain permanent colourings.

The majority of the oxidation dyes used have sufficient solubility in aqueous medium, and numerous dye supports suitable for receiving them now exist. However, the existing oxidation dye supports are not entirely satisfactory, especially as regards the power or intensity of the colourings obtained or of their chromaticity or selectivity (difference in colouring obtained between the more or less sensitized regions of a head of hair).

The second dyeing method, known as direct or semi-permanent dyeing, comprises the application of direct dyes, which are coloured and colouring molecules of natural or synthetic origin, which have affinity for fibres. Given the nature of the molecules used, they tend rather to remain on the surface of the fibre and penetrate relatively little into the fibre, when compared with the small molecules of oxidation dye precursors.

The direct dyes generally used are chosen from nitrobenzene, anthraquinone, nitropyridine, azo, methine, azomethine, xanthene, acridine, azine and triarylmethane direct dyes. The chemical species used may be nonionic, anionic (acidic dyes) or cationic (basic dyes). The majority of the direct dyes used have sufficient solubility in aqueous medium, and numerous dye supports suitable for receiving them now exist. These compositions containing one or more direct dyes are applied to keratin fibres for a time necessary to obtain the desired colouring, and are then rinsed out.

However, the colourings resulting therefrom are particularly chromatic colourings, but are, however, only temporary or semi-permanent since the nature of the interactions that bind the direct dyes to the keratin fibre and their desorption from the surface and/or the core of the fibre are responsible for their weak dyeing power and their poor persistence with respect to washing.

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

Permanent or semi-permanent dyeing processes under lightening conditions therefore need to use, with the dye composition, an aqueous composition comprising at least one oxidizing agent, under alkaline pH dyeing conditions in the vast majority of cases. The conventional processes for bleaching human keratin fibres consist in using an aqueous composition comprising at least one oxidizing agent. The role of this oxidizing agent is to degrade the melanin of the hair, which, depending on the nature of the oxidizing agent and of the pH conditions, leads to more or less pronounced lightening of the fibres.

Thus, for relatively mild lightening, the oxidizing agent is generally hydrogen peroxide. When greater lightening is desired, peroxygenated salts, for instance persulfates, are usually used in the presence of hydrogen peroxide.

Conventionally, lightening or dyeing compositions may be in the form of emulsions or nanoemulsions. However, these architectures may have instability problems, in particular phase separation, i.e. separation into two visually distinct phases with the oily phase on one side and the aqueous phase on the other. This problem of instability of the emulsion is increased in the case of oil-rich emulsions (or nanoemulsions). One solution for improving the stability of these compositions may be to increase the concentration of emulsifier(s). However, a high concentration of emulsifiers (especially of surfactants) may lead to a coarse, adhesive or tacky feel, and result in certain cases in irritation, or even stinging of the skin, the eyes and the scalp. Furthermore, in dyeing, a large content of surfactants may curb the dyeing on account of the possible interactions between the dyes and these surfactants.

In addition, nanoemulsions, which are thermodynamically unstable systems, generally require an appreciable input of energy in order to be obtained.

It is thus sought to formulate compositions that have improved properties, in particular working qualities, especially in terms of texture, ease of mixing and/or ease of application and spreading onto the hair.

It is also sought to obtain compositions that are stable over time, in particular which remain homogeneous and do not have any problem of phase separation, for example after at least 1 or even 2 months at 45°C, and which may be readily prepared.

It is also sought to obtain transparent or translucent compositions, which are pleasant to use, in particular which do not have discomfort and/or harmfulness problems, in particular such as those mentioned previously, and associated with the presence of a high content of surfactants. Finally, it is sought to obtain compositions whose dyeing and/or lightening efficacy is improved, in particular making it possible to reduce the amount of active agents and/or of composition required and/or of the application time of the composition on the fibres to dye or bleach them. Finally, it is sought to obtain compositions that make it possible to obtain better performance as regards the properties of lightening and/or dyeing of keratin fibres, especially in terms of power, resistance to external attacking factors, intensity and homogeneity, and which are sparingly selective.

The Applicant has found, surprisingly, that it is possible to overcome the problems mentioned previously by proposing a composition in the form of a microemulsion comprising a surfactant or a mixture of surfactants and at least one particular solvent chosen from solvents with a Hansen parameter δΗ of greater than 0 and less than 16 MPa^½ and an oily phase comprising at least one non-carbonyl oil.

More precisely, one subject of the present invention is thus a composition (A) for dyeing or lightening keratin fibres, such as the hair, in the form of a microemulsion comprising:

i) at least water;

H) at least one non-carbonyl-based oil;

Hi) at least one liquid organic compound with a Hansen solubility parameter value δΗ of greater than 0 and less than 16 MPa^½, the total content of liquid organic compound(s) with a Hansen solubility parameter value δΗ of greater than 0 and less than 16 MPa^½ ranging from 0.5% to 35% by weight relative to the weight of the composition;

iv) at least one surfactant;

v) at least one compound chosen from:

a. colouring agents chosen from direct dyes and oxidation dyes, and/or mixtures thereof;

b. chemical oxidizing agents;

c. basifying agents;

and mixtures thereof.

Preferably, the invention relates to a composition (A) for dyeing or lightening keratin fibres, such as the hair, in the form of a microemulsion comprising:

i) at least water;

ii) at least one non-carbonyl-based oil;

iii) at least one liquid organic compound with a Hansen solubility parameter value δΗ of greater than 0 and less than 16 MPa^½, the total content of liquid organic compound(s) with a Hansen solubility parameter value δΗ of greater than 0 and less than 16 MPa^½ ranging from 0.5% to 35% by weight relative to the weight of the composition;

iv) at least one surfactant; and

v) at least one compound chosen from:

a. colouring agents chosen from direct dyes and oxidation dyes, and/or mixtures thereof; and

b. chemical oxidizing agents;

and mixtures thereof vi) said composition possibly comprising at least one basifying agent.

In a particularly preferred manner, when said compound v) is chosen from one or more oxidation dyes a) (optionally as a mixture with one or more direct dyes), then the composition according to the invention also comprises at least one basifying agent c).

A first subject of the invention is a composition (Α') for lightening keratin fibres, in the form of a microemulsion comprising:

i) at least water;

ii) at least one non-carbonyl-based oil;

iv) at least one surfactant; and

v) at least one compound chosen from chemical oxidizing agents;

vi) and optionally at least one basifying agent.

A second subject of the invention is a composition (A") for dyeing keratin fibres, in the form of a microemulsion comprising:

i) at least water;

ii) at least one non-carbonyl-based, preferably apolar, oil;

iv) at least one surfactant;

v) at least one compound chosen from oxidation dyes; vi) and optionally at least one basifying agent. A third subject of the invention is a composition (A'") for dyeing keratin fibres, in the form of a microemulsion comprising:

i) at least water;

ii) at least one non-carbonyl-based, preferably apolar, oil;

iv) at least one surfactant; and

v) at least one compound chosen from direct dyes; vi) said composition possibly comprising at least one oxidizing agent and/or at least one basifying agent.

A fourth subject of the invention is a composition (A"") for dyeing and/or lightening keratin fibres, in the form of a microemulsion comprising:

i) at least water;

ii) at least one non-carbonyl-based, preferably apolar, oil;

iii) at least one liquid organic compound with a Hansen solubility parameter value δΗ for the solvent of greater than 0 and less than 16 MPa^½, the total content of liquid organic compound(s) with a Hansen solubility parameter value δΗ for the solvent of greater than 0 and less than 16 MPa^½ ranging from

0.5% being less than or equal to 35% by weight relative to the weight of the composition;

iv) at least one surfactant;

v) at least one compound chosen from basifying agents;

vi) said composition possibly comprising at least one oxidation dye.

A subject of the present invention is also a process for dyeing and/or lightening keratin fibres, which consists in applying at least one composition (A) to the keratin fibres.

In particular, another subject of the invention is a process for lightening keratin fibres, which consists in applying to the keratin fibres at least one composition (A) as defined previously, in which compound v) comprises at least one oxidizing agent b). In particular, a subject of the invention is a process for lightening keratin fibres, which consists in applying at least one composition (A) to the keratin fibres.

In a particularly preferred manner, when said compound v) is chosen from oxidation dyes, then the dyeing process according to the invention uses at least one oxidizing agent, which may itself optionally be included in a second composition (B) comprising at least one oxidizing agent.

Another subject of the invention is a process for dyeing keratin fibres, which consists in extemporaneously mixing at the time of use two compositions (A) and (B) and in applying said mixture to said fibres;

• composition (A) representing a composition in the form of a microemulsion comprising:

i) at least water;

ii) at least one non-carbonyl-based oil;

iv) at least one surfactant;

v) at least one compound chosen from basifying agents;

vi) said composition possibly comprising at least one oxidation dye.

A subject of the present invention is also a process for dyeing and/or lightening keratin fibres, which consists in applying to the keratin fibres at least one composition (A). In particular, another subject of the invention is a process for lightening keratin fibres, which consists in applying to the keratin fibres at least one composition (A) as defined previously, in which compound v) comprises at least one oxidizing agent b). In particular, a subject of the invention is a process for lightening keratin fibres, which consists in applying to the keratin fibres at least one composition (Α').

In a particularly preferred manner, when said compound v) is chosen from oxidation dyes, then the dyeing process according to the invention uses at least one oxidizing agent, which may optionally be included in a second composition (B) comprising at least one oxidizing agent. Another subject of the invention is a process for dyeing keratin fibres, which consists in extemporaneously mixing at the time of use two compositions (A) and (B) and in applying said mixture to said fibres;

^■ composition (A) representing a composition in the form of a microemulsion comprising:

i) at least water;

ii) at least one non-carbonyl-based oil;

iii) at least one liquid organic compound with a Hansen solubility parameter value δΗ of greater than 0 and less than 16 MPa^½, the total content of liquid organic compound(s) with a Hansen solubility parameter value δΗ of greater than 0 and less than 16 MPa^½ ranging from 0.5% to 35% by weight relative to the weight of the composition; iv) at least one surfactant;

v) at least one compound chosen from oxidation dyes;

vi) at least one basifying agent;

■ composition (B) representing a composition comprising at least one oxidizing agent.

Preferably, according to this embodiment, the second composition (B) is also in the form of a microemulsion.

Preferably, according to this embodiment, composition B comprises: at least water, at least one non-carbonyl-based, preferably apolar, oil, at least one liquid organic compound with a Hansen solubility parameter value δΗ of greater than 0 and less than 16 MPa^½, the total content of liquid organic compound(s) with a Hansen solubility parameter value δΗ of greater than 0 and less than 16 MPa^½ ranging from 0.5% to 35% by weight relative to the weight of the composition, at least one surfactant and at least one oxidizing agent.

According to this embodiment, in particular, composition B may correspond to the definition of composition (A) as defined previously, this composition also being in the form of a microemulsion and comprising at least one oxidizing agent.

According to one embodiment, the microemulsion according to the invention results from the mixing of several compositions, these compositions optionally being in the form of microemulsions. In an advantageous variant, the microemulsion according to the invention results from the mixing of several compositions, preferably two compositions, these compositions being in the form of microemulsions.

In particular, a subject of the invention is a process for dyeing keratin fibres, which consists in applying to the keratin fibres at least one composition (A").

Yet another subject of the invention is a process for dyeing keratin fibres, which consists in applying to the keratin fibres at least one composition (A) as defined previously, in which compound v) is a direct dye (optionally as a mixture with one or more chemical oxidizing agents and/or one or more basifying agents). In particular, a subject of the invention is a process for dyeing keratin fibres, which consists in applying to the keratin fibres at least one composition (A'").

A subject of this invention is also a multi-compartment device comprising at least one composition (A) in the form of a microemulsion as defined previously and at least one composition B.

A subject of this invention is also a multi-compartment device comprising a plurality of compositions, the mixing of which leads to a composition (A) in the form of a microemulsion as described previously.

The composition according to the invention is stable and the process according to the invention makes it possible to dye and/or lighten keratin fibres efficiently, homogeneously and/or intensely.

In addition, the colourings obtained are strong and/or resistant to external attacking factors and/or sparingly selective.

In addition, the composition according to the present invention has very good working qualities, and especially a particularly pleasant texture.

The composition according to the invention is generally transparent or translucent. Furthermore, it is easy to apply and to spread on the locks of hair, in particular on the roots.

In addition, it does not run and remains well located at the points of application and spreads easily from the roots to the ends.

The term "microemulsion" means a thermodynamically stable, microscopically heterogeneous and macroscopically homogeneous mixture of two mutually immiscible liquid substances, such as an oily phase and an aqueous phase. Microemulsions may be of oil-in-water type (O/W), i.e. droplets of oil dissolved in the form of direct micelles swollen in an aqueous continuous phase, or of water-in-oil type (W/O), i.e. droplets of water dissolved in the form of reverse micelles swollen in an oily continuous phase, or alternatively of bicontinuous type, i.e. in the form of structures in which the water and the oil are codissolved, the water and the oil being able to be considered simultaneously as being the continuous phase or the dispersed phase.

Microemulsions are to be distinguished from nanoemulsions, which are thermodynamically unstable dispersions of oil or water droplets in a continuous aqueous or oily phase.

Microemulsions are formed by simple mixing of the various constituents, without the need for a large energy input.

The microemulsion according to the invention has the advantage of being able to be prepared without heating, without a large energy input, which facilitates its industrial manufacture and, moreover, of being able to use heat-sensitive active agents which it may be difficult to incorporate into standard emulsions or nanoemulsions when the manufacturing process requires a heating step liable to degrade them.

In addition, microemulsions generally have a particular microstructure formed from microdroplets whose size is such that light passes through them without being scattered, and as such the appearance of this composition is transparent or translucent, whereas the appearance of a standard emulsion is opaque.

Furthermore, the microemulsion according to the invention has the advantage of being stable, even when the amount of oil present is high, in particular when it is greater than 5% or 10% or even 20% by weight relative to the weight of the composition, especially when it is desired to limit the content of surfactants.

Furthermore, relative to a standard emulsion or a nanoemulsion, the microemulsion according to the invention has the advantage of allowing better penetration of the active agents into the keratin fibre due to the small size of its microdroplets and thus of constituting a better vector for the active agents. Furthermore, a microemulsion according to the invention may contain a larger amount of active agents, and in particular of active agents that are difficult to dissolve. In particular, this makes it possible to reduce the amount of active agents and/or of dye composition required and/or the application time of the composition on the fibres to dye or bleach them.

In the case where the microemulsion according to the invention is in the form of droplets dispersed in a continuous phase, the numerical mean size of the droplets of the dispersed phase of the microemulsions of the invention is preferably less than 100 nm, even more preferentially less than 50 nm and better still between 1 and 50 nm.

The numerical mean size of the particles may be determined in particular according to the known method of quasi-elastic light scattering. As a machine that may be used for this determination, mention may be made of the Brookhaven brand machine equipped with an SX 200 optical bed (with a 532 nm laser) and a Bl 9000 correlator. This machine gives a measurement of the mean diameter by photon correlation spectroscopy (PCS), which makes it possible to determine the numerical mean diameter from the polydispersity factor, which is also measured by the machine.

The microemulsion may be prepared via standard processes for preparing microemulsions, which are well known to those skilled in the art, in particular following the production of phase diagrams for determining the formation domain of the microemulsion.

According to a particular embodiment of the invention, the microemulsion according to the invention has the advantage of being able to comprise a limited content of emulsifiers, especially of surfactants, while at the same time remaining stable. Specifically, even after treating in a centrifuge, the microemulsion according to the invention spontaneously returns to its initial thermodynamic equilibrium at a given temperature. Moreover, the microemulsion remains stable even after 2 months of storage at 45°C. Such a composition has the advantage of limiting the abovementioned drawbacks associated with a very high concentration of emulsifiers.

Preferably, the composition according to the invention comprises a total content of surfactants of between 0.1 % and 30% by weight, preferably between 1 % and 25% by weight and better still between 5% and 19% by weight relative to the total weight of the composition. 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 within that range.

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

The term "at least one" is equivalent to "one or more". The composition according to the invention comprises at least one compound v) chosen from:

a) colouring agents chosen from direct dyes and oxidation dyes, and/or mixtures thereof; and

b) chemical oxidizing agents;

c) chemical basifying agents;

d) and mixtures thereof. DYES:

According to a first embodiment, the composition according to the invention comprises at least one compound v) a) chosen from colouring agents chosen from direct dyes and oxidation dyes, and/or mixtures thereof.

In particular, according to this embodiment, the composition according to the invention comprises at least one colouring agent chosen from oxidation dyes and/or direct dyes, and mixtures thereof.

The colouring agent(s) used in the composition according to the invention may be oxidation dyes (also known as oxidation dye precursors) and/or direct dyes, which may be of synthetic or natural origin.

Oxidation dyes

According to a particular embodiment of the invention, the composition comprises at least one oxidation dye.

For the purposes of the invention, the term "oxidation dye", also referred to as an "oxidation dye precursor", means a species that is capable of generating a coloured molecule via a process of oxidative condensation with itself or with one or more other compounds.

The oxidation dye precursors are chosen from oxidation bases and couplers, and mixtures thereof.

Preferably, the oxidation dyes comprise an oxidation base or a mixture.

The oxidation bases may be chosen from para-phenylenediamines, bis(phenyl)alkylenediamines, para-aminophenols, ortho-aminophenols and heterocyclic bases, and the addition salts thereof.

Preferentially, the oxidation base(s) of the invention are chosen from para- phenylenediamines and heterocyclic bases.

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, 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(p-hydroxyethyl)- para-phenylenediamine, 4-N,N-bis(P-hydroxyethyl)amino-2-methylaniline, 4-N,N- bis(p-hydroxyethyl)amino-2-chloroaniline, 2-p-hydroxyethyl-para-phenylenediamine, 2-fluoro-para-phenylenediamine, 2-isopropyl-para-phenylenediamine, Ν-(β- hydroxypropyl)-para-phenylenediamine, 2-hydroxymethyl-para-p enylenediamine, 2- methoxymethyl-para-phenylenediamine, N,N-dimethyl-3-methyl-para- phenylenediamine, N-ethyl-N-(p-hydroxyethyl)-para-phenylenediamine, Ν-(β,γ- dihydroxypropyl)-para-phenylenediamine, N-(4'-aminophenyl)-para- phenylenediamine, N-phenyl-para-phenylenediamine, 2-p-hydroxyethyloxy-para- phenylenediamine, 2-p-acetylaminoethyloxy-para-phenylenediamine, Ν-(β- methoxyethyl)-para-phenylenediamine, 4-aminophenylpyrrolidine, 2-thienyl-para- phenylenediamine, 2-p-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-phenylenediamine, 2- -hydroxyethyl-para- phenylenediamine, 2-p-hydroxyethyloxy-para-phenylenediamine, 2,6-dimethyl-para- phenylenediamine, 2,6-diethyl-para-phenylenediamine, 2,3-dimethyl-para- phenylenediamine, N,N-bis(p-hydroxyethyl)-para-phenylenediamine, 2-chloro-para- phenylenediamine, 2-p-acetylaminoethyloxy-para-phenylenediamine and 2- methoxymethyl-para-phenylenediamine, and the addition salts thereof with an acid, are particularly preferred.

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

Among the para-aminophenols, examples that may be mentioned include 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-methoxymethylphenol, 4-amino-2- aminomethylphenol, 4-amino-2-(p-hydroxyethyl-aminomethyl)phenol and 4-amino-2- fluorophenol, and the addition salts thereof with an acid.

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

Among the heterocyclic bases, mention may be made in particular of pyridine derivatives, pyrimidine derivatives and pyrazole derivatives.

Among the pyridine derivatives, mention may be made of 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 the 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-yl)pyrazolo[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-aminopyrazolo[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- yl)pyrazolo[1 ,5-a]pyrid-3-ylamine, pyrazolo[1 ,5-a]pyridine-3,5-diamine, 5-(morpholin- 4-yl)pyrazolo[1 ,5-a]pyrid-3-ylamine, 2-[(3-aminopyrazolo[1 , 5-a] py rid-5-y I )(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-aminopyrazolo[1 ,5- a]pyridin-4-ol, 3-aminopyrazolo[1 ,5-a]pyridin-6-ol, 3-aminopyrazolo[1 ,5-a]pyridin-7-ol, 2-p-hydroxyethoxy-3-aminopyrazolo[1 ,5-a]pyridine and 2-(4-dimethylpiperazinium-1- yl)-3-aminopyrazolo[1 ,5-a]pyridine, and also the addition salts thereof.

More particularly, the oxidation bases according to the invention are chosen from 3-aminopyrazolo[1 ,5-a]pyridines preferably substituted in position 2 with:

a) a (di)(Ci-C₃)(alkyl)amino group, the alkyl groups possibly being substituted with one or more hydroxyl, amino or imidazolium groups;

b) a cationic or non-cationic 5- to 7-membered heterocycloalkyl group comprising from 1 to 3 heteroatoms, optionally substituted with one or more (Ci-

C₆)alkyl groups such as di(Ci-C₄)alkylpiperazinium;

c) a (Ci-Ce)alkoxy group optionally substituted with one or more hydroxyl groups, such as β-hydroxyalkoxy, and also the addition salts thereof.

Among the pyrimidine derivatives, mention may be made of the compounds described, for example, in patents DE 2359399, JP 88169571 , JP 05-63124 and 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 the addition salts thereof, and the tautomeric forms thereof, when a tautomeric equilibrium exists.

Among the pyrazole derivatives mention may be made of the compounds described in patents DE 3843892 and DE 4133957 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 -(p-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-1 -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-hydroxymethylpyrazole, 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- methylaminopyrazole and 3, 5-diamino-4-(p-hydroxyethyl)amino-1 -methylpyrazole, and the addition salts thereof. Preferably, the heterocyclic oxidation bases of the invention are chosen from 4,5-diaminopyrazoles such as 4,5-diamino-1-( - hydroxyethyl)pyrazole. Use may also be made of 4,5-diamino-1-(P- methoxyethyl)pyrazole.

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

Pyrazole derivatives 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-bis(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-dimethylaminopyrrolidin-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.

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

Heterocyclic bases that will preferentially be used include 4,5-diamino-1-(p- 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.

Preferably, the total content of oxidation bases used in the context of the invention is between 0.001% to 10% by weight and preferably ranging from 0.005% to 5%, relative to the total weight of the composition.

The couplers that are conventionally used for the dyeing of keratin fibres may be chosen from the meta-phenylenediamines, meta-aminophenols, meta-diphenols, naphthalene-based couplers and heterocyclic couplers, and also the addition salts thereof. Examples that may be mentioned include 1 ,3-dihydroxybenzene, 1 ,3-dihydroxy- 2-methylbenzene, 4-chloro-1 ,3-dihydroxybenzene, 1 -hydroxy-3-aminobenzene, 2- methyl-5-aminophenol, 3-amino-2-chloro-6-methylphenol, 2-methyl-5- hydroxyethylaminophenol, 2,4-diamino-1 -(3-hydroxyethyloxy)benzene, 2-amino-4-(P- hydroxyethylamino)-1 -methoxybenzene, 1 ,3-diaminobenzene, 1 ,3-bis(2,4- diaminophenoxy)propane, 3-ureidoaniline, 3-ureido-1 -dimethylaminobenzene, sesamol, thymol, 1-β-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-(3-hydroxyethyl)amino-3,4-methylenedioxybenzene, 2,6- bis(3-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.

In general, the addition salts of the oxidation bases and couplers that may be used within the context of the invention 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.

In the context of the present invention, when they are present, the coupler(s) are generally each present in a total amount ranging from 0.001% to 10% by weight approximately of the total weight of the dye composition, and preferably ranging from 0.005% to 5% by weight relative to the total weight of the dye composition.

Preferably, the total content of oxidation couplers used in the context of the invention is between 0.001 % to 10% by weight relative to the total weight of the dye composition.

According to a preferred embodiment, the colouring agent is an oxidation dye, preferably chosen from oxidation bases such as para-phenylenediamines, bis(phenyl)alkylenediamines, para-aminophenols, ortho-aminophenols and heterocyclic bases, and the addition salts thereof, and couplers, chosen from meta- phenylenediamines, meta-aminophenols, meta-diphenols, naphthalene-based couplers and heterocyclic couplers, and also the addition salts thereof; and mixtures thereof.

In the context of the present invention, when they are present, the colouring agent(s) are present in a total amount ranging from 0.001 % to 10% by weight relative to the total weight of the dye composition.

DIRECT DYES

According to another particular embodiment of the invention, the composition comprises at least one direct dye.

The direct dye(s) may be chosen from synthetic direct dyes and natural direct dyes. The term "synthetic direct dye" means any direct dye that does not exist in the natural state, including dyes obtained semi-synthetically.

Examples of suitable synthetic direct dyes that may be mentioned include azo, methine, carbonyl, azine, xanthene, nitro(hetero)aryl, tri(hetero)arylmethane, (metallo)porphyrin and phthalocyanine direct dyes, alone or as mixtures.

More particularly, the synthetic azo direct dyes include an -N=N- function in which the two nitrogen atoms are not simultaneously part of a ring. However, it is not excluded for one of the two nitrogen atoms of the sequence -N=N- to be part of a ring.

Examples of azo direct dyes that may be mentioned include the following dyes, described in 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.

The direct dyes of the methine family are more particularly compounds comprising at least one sequence chosen from >C=C< and -N=C< in which the two atoms are not simultaneously part of a ring. However, it is pointed out that one of the nitrogen or carbon atoms of the sequences may be part of a ring.

More particularly, the methine dyes are derived from methine, azomethine, hydrazono, mono- and diarylmethane, indoamine (or diphenylamine), indophenol, indoaniline and (hemi)cyanine compounds, such as styryl, streptocyanine, carbocyanine, azacarbocyanine, diazacarbocyanine and tetraazacarbocyanine, such as tetraazapentamethine, dyes, and optical and geometric isomers thereof.

Among the azo, azomethine, methine or 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 714954; FR 2189006, FR 2285851 , FR 2140205, EP 1378544, EP 1674073.

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

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

- 2-p-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 compounds given in the table below:

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

As regards the synthetic direct dyes of the carbonyl family, examples that may be mentioned include dyes chosen from quinone, acridone, benzoquinone, anthraquinone, naphthoquinone, benzanthrone, anthranthrone, pyranthrone, pyrazolanthrone, pyrimidinoanthrone, flavanthrone, idanthrone, flavone, (iso)violanthrone, isoindolinone, benzimidazolone, isoquinolinone, anthrapyridone, pyrazoloquinazolone, perinone, quinacridone, quinophthalone, indigoid, thioindigo, naphthalimide, anthrapyrimidine, diketopyrrolopyrrole and coumarin dyes.

Among the quinone direct dyes, mention may be made of 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;

- 5-p-hydroxyethyl-1 ,4-diaminoanthraquinone;

- 2-aminoethylaminoanthraquinone;

- 1 ,4-bis(p,y-dihydroxypropylamino)anthraquinone.

As regards the synthetic direct dyes of the azine family, mention may be made especially of azine, fluorindine, acridine, (di)oxazine and (di)thiazine dyes.

Examples of azine dyes that may be mentioned include the following compounds:

- Basic Blue 17

- Basic Red 2.

As regards the synthetic direct dyes of the xanthene family, mention may be made especially of xanthene, thioxanthene and pyronine dyes.

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

Among the nitrobenzene 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-4-3-hydroxyethylaminobenzene

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

- 1 ,4-bis(3-hydroxyethylamino)-2-nitrobenzene

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

- 1-3-hydroxyethylamino-2-nitro-4-aminobenzene

- 1-p-hydroxyethylamino-2-nitro-4-(ethyl)( -hydroxyethyl)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-p-hydroxyethylamino-5-nitrobenzene

- 1 ,2-bis(p-hydroxyethylamino)-4-nitrobenzene - 1-amino-2-tris(hydroxymGthyl)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 -p-hydroxyethyloxy-2-p-hydroxyethylamino-5-nitrobenzene

- 1-methoxy-2- -hydroxyethylamino-5-nitrobenzene

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

- 1-p,y-dihydroxypropyloxy-3-methylamino-4-nitrobenzene

- 1-p-hydroxyethylamino-4-p,y-dihydroxypropyloxy-2-nitrobenzene

- 1-p,y-dihydroxypropylamino-4-trifluoromethyl-2-nitrobenzene

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

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

- 1-p-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(p-hydroxyethyl)amino-3-nitrobenzene

- 1-p-hydroxyethylamino-2-nitrobenzene

- 1-hydroxy-4-p-hydroxyethylamino-3-nitrobenzene.

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

As regards the (metallo)porphyrin or phthalocyanine synthetic direct dyes, use may be made of cationic or non-cationic compounds, optionally comprising one or more metals or metal ions, for instance alkali metals and alkaline-earth metals, zinc and silicon.

Examples of particularly suitable synthetic direct dyes that may be mentioned include nitrobenzene dyes; azo, methine, azomethine, hydrazono or styryl direct dyes; azacarbocyanines such as tetraazacarbocyanines (tetraazapentamethines); quinone direct dyes, and in particular anthraquinone, naphthoquinone or benzoquinone direct dyes; azine direct dyes; xanthene direct dyes; triarylmethane direct dyes; indoamine direct dyes, indigoid direct dyes, phthalocyanine direct dyes and porphyrin direct dyes, alone or as mixtures.

These 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 chemical family or otherwise. It should be noted that a polychromophoric dye comprises a plurality of groups 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.

In the case of polychromophoric dyes, the chromophores are connected together by means of at least one linker L, which may be cationic or non-cationic.

The linker L is preferably a linear, branched or cyclic C1-C20 alkyl chain which is optionally interrupted and/or terminated with at least i) a heteroatom (such as nitrogen N(R), N⁺R, R', Q^", oxygen or sulfur), ii) a group C(O), C(S), S(O), or S(0)₂ or iii) a combination thereof, optionally interrupted with at least one heterocycle which may or may not be fused to a phenyl nucleus, and which comprises at least one quaternized nitrogen atom forming part of said ring system, and optionally at least one other heteroatom (such as oxygen, nitrogen or sulfur), optionally interrupted with at least one substituted or unsubstituted phenyl or naphthyl, optionally at least one quaternary ammonium group substituted with two C-i-Ci₅ alkyl groups which are optionally substituted; the linker does not contain a nitro, nitroso or peroxo group, and R and R', which may be identical or different, represent a hydrogen atom or a Ci-C₆ alkyl group which is optionally substituted, preferably with at least one hydroxyl group, and Q^" represents an organic or mineral anionic counterion such as a halide or an alkyl sulfate.

If the heterocycles or aromatic nuclei are substituted, they are substituted, for example, with one or more Ci-Cs alkyl groups optionally substituted with a hydroxyl, C1-C2 alkoxy, C₂-C₄ hydroxyalkoxy, acetylamino or amino group substituted with one or two C1-C4 alkyl groups, optionally bearing at least one hydroxyl group, or the two groups possibly forming, with the nitrogen atom to which they are attached, a 5- or 6- membered heterocycle, optionally comprising another nitrogen or non-nitrogen heteroatom; a halogen atom; a hydroxyl group; a C1-C2 alkoxy group; a C₂-C₄ hydroxyalkoxy group; an amino group; an amino group substituted with one or two identical or different C1-C4 alkyl groups, optionally bearing at least one hydroxyl group.

According to a particularly advantageous embodiment of the invention, the dye(s) are chosen from (poly)azo dyes such as (di)azo dyes; hydrazono dyes; (poly)methine dyes such as styryl dyes; anthraquinone dyes and naphthalimide dyes. Preferably, these dyes are (poly)cationic.

According to an even more preferred embodiment of the invention, the dyes are chosen from cationic dyes known as "basic dyes".

Mention may be made of the cationic hydrazono dyes of formulae (I) and (Γ), the azo dyes (II) and (Ι ) and the diazo dyes (III) below:

Het⁺-C(R^a)=N-N(R^b)- Het⁺-N(R^a)-N=C(R^b)- Het⁺-N=N-Ar,

Ar, Q-(l) Ar, Q-(l') Q-(ll)

Ar⁺-N=N-Ar", Q^" and Het⁺-N=N-Ar'

(II') -N=N-Ar, Q^"

(III) in which formulae (I), (Ι'), (II), (H')and (II I):

Het⁺ represents a cationic heteroaryl group, preferably bearing an endocyclic cationic charge, such as imidazolium, indolium or pyridinium, optionally substituted preferentially with one or more Ci-C₈ alkyl groups such as methyl; Ar⁺ represents an aryl group, such as phenyl or naphthyl, bearing an exocyclic cationic charge, preferentially ammonium, particularly tri(d-C₈ alkyl)ammonium such as trimethylammonium;

- Ar represents an aryl group, especially phenyl, which is optionally substituted, preferably with one or more electron-donating groups such as i) optionally substituted Ci-C₈ alkyl, ii) optionally substituted Ci-C₈ alkoxy, iii) (di)(Ci-C₈ alkyl)amino optionally substituted on the alkyl group(s) with a hydroxyl group, iv) aryl(CrC₈ alkyl)amino, or v) optionally substituted N-(Ci-C₈ alkyl)-N-aryl(Ci-C₈ alkyl)amino, or alternatively Ar represents a julolidine group;

Ar' is an optionally substituted divalent (hetero)arylene group such as phenylene, particularly para-phenylene, or naphthalene, which are optionally substituted, preferably with one or more Ci-C₈ alkyl, hydroxyl or Ci-C₈ alkoxy groups;

- Ar" is an optionally substituted (hetero)aryl group such as phenyl or pyrazolyl, which are optionally substituted, preferably with one or more Ci-C₈ alkyl, hydroxyl,

(di)(Ci-C₈ alkyl)amino, Ci-C₈ alkoxy or phenyl groups;

R^a and R^b, which may be identical or different, represent a hydrogen atom or a Ci- C₈ alkyl group, which is optionally substituted, preferentially with a hydroxyl group; or alternatively the substituent R^a with a substituent of Het⁺ and/or R^b with a substituent of Ar form, together with the atoms that bear them, a (hetero)cycloalkyl; particularly, R^a and R^b represent a hydrogen atom or a C₁-C4 alkyl group, which is optionally substituted with a hydroxyl group;

Q^" represents an organic or mineral anionic counterion, such as a halide or an alkyl sulfate.

In particular, the dyes of the invention are cationically charged, endocyclic, azo and hydrazono dyes of formulae (I), (Ι') and (II) as defined previously. The dyes of formulae (I), (Γ) and (II) described in patent applications WO 95/15144, WO 95/01772 and EP 714954 are more particularly preferred.

Dyes of the invention are preferentially chosen from the following compounds:

in which formulae (1-1 ) and (11-1 ):

R¹ represents a C₁-C4 alkyl group such as methyl;

R² and R³, which may be identical or different, represent a hydrogen atom or a Ci- C₄ alkyl group such as methyl; and

- R⁴ represents a hydrogen atom or an electron-donating group such as optionally substituted Ci-C₈ alkyl, optionally substituted Ci-C₈ alkoxy, or (di)(Ci-C₈ alkyl)amino optionally substituted on the alkyl group(s) with a hydroxyl group; particularly, R⁴ is a hydrogen atom;

- Z represents a CH group or a nitrogen atom, preferably CH;

- Q^" is as defined previously.

In particular, the dyes of formulae (1-1 ) and (11-1 ) are chosen from Basic Red 51 , Basic Yellow 87 and Basic Orange 31 or their derivatives:

where Q^" is as defined previously, and represents in particular a halide such as a chloride, or an alkyl sulfate such as methyl sulfate or mesityl.

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

Among the polychromophoric dyes, mention may be made more particularly of the symmetrical or non-symmetrical di- or trichromophoric azo and/or azomethine (hydrazone) dyes, comprising on the one hand at least one 5- or 6-membered aromatic heterocycle, optionally fused, which comprises at least one quaternized nitrogen atom forming part of said heterocycle, and optionally at least one other heteroatom (such as nitrogen, sulfur or oxygen), and, on the other hand, at least one optionally substituted phenyl or naphthyl group optionally bearing at least one group OR in which R represents a hydrogen atom, an optionally substituted CrC₆ alkyl group, an optionally substituted phenyl nucleus, or at least one group N(R')₂ with R', which may be identical or different, representing a hydrogen atom, an optionally substituted Ci-C₆ alkyl group or an optionally substituted phenyl nucleus; the groups R' possibly forming, with the nitrogen atom to which they are attached, a saturated, 5- or 6-membered heterocycle, or else one and/or both of the groups R' may each form a saturated, 5- or 6-membered heterocycle with the carbon atom of the aromatic ring that is ortho to the nitrogen atom.

Aromatic cationic heterocycles that may preferably be mentioned include 5- or 6-membered rings containing 1 to 3 nitrogen atoms and preferably 1 or 2 nitrogen atoms, one being quaternized; said heterocycle moreover being optionally fused to a benzene nucleus. It should similarly be noted that the heterocycle may optionally comprise another heteroatom other than nitrogen, for instance sulfur or oxygen.

If the heterocycles or phenyl or naphthyl groups are substituted, they are substituted, for example, with one or more C Cs alkyl groups optionally substituted with a hydroxyl, CrC₂ alkoxy, C₂-C₄ hydroxyalkoxy, acetylamino or amino group substituted with one or two Ci-C₄ alkyl groups, optionally bearing at least one hydroxyl group, or the two groups possibly forming, with the nitrogen atom to which they are attached, a 5- or 6-membered heterocycle, optionally comprising another nitrogen or non-nitrogen heteroatom; a halogen atom; a hydroxyl group; a C₁-C₂ alkoxy group; a C₂-C₄ hydroxyalkoxy group; an amino group; an amino group substituted with one or two identical or different C₁-C4 alkyl groups, optionally bearing at least one hydroxyl group.

These polychromophores are connected together via at least one linker L as defined previously.

The bonding between the linker L and each chromophore generally takes place via a heteroatom substituent on the phenyl or naphthyl nucleus or via the quaternized nitrogen atom of the cationic heterocycle.

The dye may comprise identical or different chromophores.

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 1 399 117, EP 1 416 909, EP 1 399 1 16 and EP 1 671 560.

It is equally possible to use cationic synthetic direct dyes which are mentioned in the following patent applications: EP 1 006 153, which describes dyes comprising two chromophores of anthraquinone type connected via a cationic linker; 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 diazacarbocyanine type or an isomer thereof.

The term "natural dyes" means any dye or dye precursor that is naturally occurring and that is produced either by extraction (and possibly purification) from a plant or animal matrix, optionally in the presence of natural compounds such as ash or ammonia, or by chemical synthesis. Natural dyes that may be mentioned include lawsone, henna, curcumin, chlorophyllin, alizarin, kermesic acid, purpurin, purpurogallin, indigo, Tyrian purple, sorghum, carminic acid, catechin, epicatechin, juglone, bixin, betanin, quercetin, chromene dyes and chroman dyes, including haematein and brazilein, and laccaic acids, alone or as a mixture.

Preferably, the natural dyes used in the invention are chosen from curcumin, chlorophylline, chromene dyes, chroman dyes and laccaic acids.

According to the invention, the terms "chromene dye" and "chroman dye" mean dyes which comprise in their structure at least one bicycle of formula (IV) below:

the endocyclic bond representing a carbon-carbon single bond or a carbon-carbon double bond, as illustrated by formula IV-1 denoting the chromene family :

IV-1 IV-2

More particularly, the dyes having in their structure a bicycle of formula (IV) chosen from the dyes having the following formulae:

ula IV-2,

in which: i) represents a carbon-carbon single bond or a carbon-carbon double bond, the sequence of these bonds denoting two carbon-carbon single bonds and two carbon-carbon double bonds, said bonds being conjugated,

ii) X represents a group:

// /

HO— C or 0=C

\ \

iii) R¹ , R², R³, R⁴, R⁵ and R^s, which may be identical or different, represent, independently of each other, a hydrogen atom, a hydroxyl group, an optionally substituted alkyl group, an optionally substituted alkoxy group or an optionally substituted acyloxy group,

and also the tautomeric and/or mesomeric forms thereof, the stereoisomers thereof, the addition salts thereof with a cosmetically acceptable acid or base, and the hydrates thereof, and

- formula (VI), comprising in its structure the bicycle of formula IV-1 :

in which:

- Ri i , R-I 2, Ri3, Ri6, Ri9 and R₂o, which may be identical or different, represent, independently of each other, a hydrogen atom or a Ci-C₄ alkyl group,

- Ri4, R-I5, Ri7 and R-is, which may be identical or different, represent, independently of each other, a hydrogen atom, a hydroxyl group or a CrC₄ alkoxy group,

and also the tautomeric and/or mesomeric forms thereof, the stereoisomers thereof, the addition salts thereof with a cosmetically acceptable acid or base, and the hydrates thereof.

As regards the dyes of formula (V) as defined previously, they may be in two tautomeric forms noted (Va) and (Vb):

The alkyl groups mentioned in the preceding definitions of the substituents are linear or branched, saturated hydrocarbon groups, generally C1-C20, particularly d- C10 and preferably Ci-C₃, such as methyl, ethyl, propyl, butyl, pentyl and hexyl.

The alkoxy groups are alkyl-oxy groups with alkyl groups as defined previously and preferably the alkoxy groups are C1-C10, such as methoxy, ethoxy, propoxy and butoxy.

The alkyl or alkoxy groups, when they are substituted, may be substituted with at least one substituent borne by at least one carbon atom, chosen from:

a halogen atom;

- a hydroxyl group;

- a C1-C2 alkoxy group;

a C1-C10 alkoxycarbonyl group;

- a C2-C4 (poly)hydroxyalkoxy group;

an amino group;

- a 5- or 6-membered heterocycloalkyl group;

an optionally cationic 5- or 6-membered heteroaryl group, preferentially imidazolium, optionally substituted with a (CrC4)alkyl group, preferentially methyl;

an amino group substituted with one or two identical or different C1-C6 alkyl groups, optionally bearing at least:

^* a hydroxyl group,

^* an amino group optionally substituted with one or two optionally substituted C1-C3 alkyl groups, it being possible for said alkyl groups to form, with the nitrogen atom to which they are attached, a saturated or unsaturated and optionally substituted 5- to 7-membered heterocycle, optionally comprising at least one other nitrogen or non-nitrogen heteroatom,

^* a quaternary ammonium group -N⁺R'R"R"', M^" for which R', R" and R"\ which may be identical or different, represent a hydrogen atom or a C1-C4 alkyl group; and

M^" represents the counterion of the corresponding organic or mineral acid or of the corresponding halide; ^* or an optionally cationic 5- or 6-membered heteroaryl group, preferentially imidazolium, optionally substituted with a (Ci-C₄) alkyl group, preferentially methyl;

an acylamino group (-N -CO ') in which the group R is a hydrogen atom or a C C₄ alkyl group optionally bearing at least one hydroxyl group and the group R' is a Ci-C₂ alkyl group;

a carbamoyl group ((R)₂N-CO-) in which the groups R, which may be identical or different, represent a hydrogen atom or a C1-C4 alkyl group optionally bearing at least one hydroxyl group;

an alkylsulfonylamino group (R'S0₂-NR-) in which the group R represents a hydrogen atom or a C1-C4 alkyl group optionally bearing at least one hydroxyl group and the group R' represents a C1-C4 alkyl group, or a phenyl group;

an aminosulfonyl group ((R)₂N-S0₂-) in which the groups R, which may be identical or different, represent a hydrogen atom or a C1-C4 alkyl group optionally bearing at least one hydroxyl group;

a carboxylic group in acid or salified form (preferably with an alkali metal or a substituted or unsubstituted ammonium);

a cyano group;

- a nitro group;

- a carboxyl or glycosylcarbonyl group;

a phenylcarbonyloxy group optionally substituted with one or more hydroxyl groups;

- a glycosyloxy group; and

a phenyl group optionally substituted with one or more hydroxyl groups. The term "glycosyl group" means a group originating from a mono- or polysaccharide.

Preferably, the alkyl or alkoxy groups of formula (V) are unsubstituted.

According to one particular embodiment of the invention, the dyes of formula (V) comprise a group R^s which represents a hydroxyl group.

In one preferred variant, X represents a group 0=C.

Another particular embodiment of the invention relates to the dyes of formula (V), for which the group R¹ represents a hydrogen atom or a hydroxyl group.

More particularly, the dyes of formula (V) are chosen from haematein and brazilein.

Brazilein is a conjugated form of a chroman compound of formula IV-2. The tautomeric structures (Va) and (Vb) illustrated above are found in the scheme below.

Brazilein and haematein or the haematoxylin/haematein and brazilin/brazilein pairings may be obtained synthetically or by extraction of plants known to be rich in these dyes.

The dyes of formula (V) may be used in the form of extracts. Use may be made of the following plant extracts (genus and species): Haematoxylon campechianum, Haematoxylon brasiletto, Caesalpinia echinata, Caesalpinia sappan, Caesalpinia spinosa and Caesalpinia brasiliensis.

The extracts are obtained by extracting various plant parts, for instance the root, the wood, the bark or the leaves.

According to one particular embodiment of the invention, the natural dyes of formula (V) are obtained from logwood, pernambuco wood, sappan wood and Brazil wood.

The salts of the dyes of formulae (V) and (VI) of the invention may be salts of cosmetically acceptable acids or bases.

The acids may be mineral or organic. Preferably, the acid is hydrochloric acid, which results in chlorides.

The bases may be mineral or organic. In particular, the bases are alkali metal hydroxides such as sodium hydroxide which leads to sodium salts.

Preferably, the dye(s) of formulae (V) and (VI) included in the composition according to the invention are derived from plant extracts. Use may also be made of mixtures of plant extracts.

The natural extracts of the dyes according to the invention may be in the form of powders or liquids. Preferably, the extracts are provided in powder form.

In another variant of the invention, the natural dyes are chosen from laccaic acids.

For the purposes of the present invention, the term "laccaic acid" means a compound having in its structure a unit of the type:

Preferably, the laccaic acids of the invention are of formula (VII) below:

(VII)

with R-i denoting a phenyl group substituted with at least one hydroxyl group, and preferably with a hydroxyl group that is advantageously in the ortho position relative to the bond attaching it to the fused nuclei.

In particular, the phenyl group Ri comprises, besides a hydroxyl group, at least one group -CH₂R₂, R₂ denoting an acetamidomethyl (CH₃CONHCH₂-), hydroxymethyl (HOCH₂-) or 2-aminoacetic acid group (H0₂C(NH₂)CH-).

Preferentially, the laccaic acids of the invention are chosen from laccaic acids A, B, C and D, or mixtures thereof, and more particularly chosen from A, B and C, or mixtures thereof.

A laccaic acid according to the invention that may especially be used is the dye CI Natural Red 25, CI 75450, CAS - 60687-93-6, which is often referred to as laccaic acid. This is a dye of natural origin originating from the secretions of an insect, Coccus laccae (Lacifer Lacca Kerr), which is generally found on the twigs of certain trees native to South-East Asia.

CI Natural Red 25 generally contains two major constituents in its composition: laccaic acid A and laccaic acid B. It may also contain a small amount of laccaic acid C.

It is obviously also possible to use the purified forms of the laccaic acids of formula (VII).

Even more preferentially, the natural direct dyes are chosen from haematein and brazilein.

The direct dye(s) may be present in a total content ranging from 0.001 % to 10% by weight, preferably from 0.01 % to 5% by weight and more preferentially from 0.1 % to 2% by weight, relative to the total weight of the composition.

OXIDIZING AGENT

The composition of the invention may comprise one or more oxidizing agents, preferably one or more chemical oxidizing agents.

The term "chemical oxidizing agent" means an oxidizing agent other than atmospheric oxygen.

More particularly, the oxidizing agent(s) are 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 also peracids and precursors thereof.

Advantageously, the oxidizing agent is hydrogen peroxide.

The content of oxidizing agent(s) more particularly represents from 0.1 % to 50% by weight, preferably from 0.5% to 20% by weight and better still from 1 % to 15% by weight relative to the weight of composition A (and/or of composition B when it is present, or even of the ready-to-use composition).

When composition A comprises a colouring agent, in particular an oxidation dye, the oxidizing agent is added to the composition at the time of use and is preferably provided by an oxidizing composition B.

Preferably, the oxidizing agent is hydrogen peroxide, the concentration of which ranges, more particularly, from 0.1 % to 50% by weight, more particularly between 0.5% and 20% by weight and even more preferentially between 1 % and 15% by weight relative to the weight of the oxidizing composition.

Preferably, the composition of the invention does not contain any peroxygenated salts.

BASIFYING AGENTS: The composition (A) (and/or composition (B) when it is present) according to the invention may comprise one or more basifying agents.

I n particular, when the composition according to the invention comprises at least one oxidation dye, it also comprises at least one basifying agent.

The basifying agent(s) may be mineral or organic or hybrid.

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

The organic basifying agent(s) are preferably chosen from organic amines with a pK_b at 25°C of less than 12, preferably less than 10 and even more advantageously less than 6. It should be noted that it concerns the pK_b corresponding to the functional group having the highest basicity. In addition, the organic amines do not comprise any alkyl or alkenyl fatty chain comprising more than ten carbon atoms.

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:

N - W - N

|)

in which formula (I) W is a divalent Ci-C₆ alkylene radical optionally substituted with one or more hydroxyl groups or a C1-C6 alkyl radical, and/or optionally interrupted with one or more heteroatoms such as O, or N R_U; R_x, R_y, R_z, R_t and R_u, which may be identical or different, represent a hydrogen atom or a C1-C6 alkyl, C1-C6 hydroxyalkyl or Ci-C₆ aminoalkyl radical.

Examples of amines of formula (I) 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 d-Cs alkyl groups bearing one or more hydroxyl radicals.

Organic amines chosen from alkanolamines such as monoalkanolamines, dialkanolamines or trialkanolamines comprising one to three identical or different Ci- C4 hydroxyalkyl radicals are in particular suitable for performing the invention .

Among the compounds of this type, mention may be made of monoethanolamine (MEA), diethanolamine, triethanolamine, monoisopropanolamine, diisopropanolamine, N-dimethylaminoethanolamine, 2-amino-2-methyl-1 -propanol, triisopropanolamine, 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 can be used are of natural or synthetic origin, in their L, D or racemic form, and comprise at least one acid function chosen more particularly from carboxylic acid, sulfonic acid, phosphonic acid or phosphoric acid functions. The amino acids may be in neutral or ionic form. As amino acids that may be used in the present invention, mention may be made in particular 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, and also the salts thereof:

NH,

_ / ²

R CH₂ CH _^

C°2^H (II)

in whi II) R represents a group chosen from:

(CH₂)₃NH₂

-(CH₂)₂NH₂; -(CH₂)₂NHCONH₂; and

-(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 in particular be made 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 in particular of carnosine, anserine and balenine.

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, which 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.

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

Guanidine carbonate or monoethanolamine hydrochloride may be used in particular.

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

Preferably, the organic basifying agent(s) present in the composition of the invention are chosen from alkanolamines, amino acids in neutral or ionic form, in particular basic amino acids, and preferably corresponding to those of formula (II). Even more preferentially, the organic basifying agent(s) are chosen from monoethanolamine (MEA) and basic amino acids in neutral or ionic form. Better still, the organic basifying agent(s) are chosen from alkanolamines such as monoethanolamine.

Advantageously, the composition according to the invention has a content of basifying agent(s) ranging from 0.01 % to 30% by weight and preferably from 0.1 % to 20% by weight relative to the weight of the composition.

According to a first embodiment, the basifying agent is ammonia or a salt thereof.

According to a second particular embodiment, the composition according to the invention or the process according to the invention does not use ammonia, or a salt thereof, as basifying agent.

According to a third embodiment, the composition according to the invention comprises a mixture of basifying agents.

According to another particular embodiment, the basifying agent is chosen from alkanolamines, preferably monoethanolamine.

Liquid organic compounds with a Hansen solubility parameter 5H of greater than 0 and less than 16 MPa^{1 2}:

The composition of the invention comprises from 0.5% to 35% by weight of at least one liquid organic compound with a Hansen solubility parameter 5H of greater than 0 and less than 16 MPa^1/2.

Such a compound is different from the oils, and also from the surfactants described hereafter.

Such a compound is also known as a hydrotropic compound.

For the purposes of the present invention, the term "hydrotropic compound" means a compound that is capable of increasing the solubility of hydrophobic compounds in aqueous phases.

Said liquid compounds more preferentially have a Hansen solubility parameter 5H of between 5 and 15.8 MPa^1/2, even more preferentially between 8 and 15.8 MPa^{1 2} and better still between 8 and and 15 MPa^1/2.

These compounds are liquid at a temperature of 25°C and at atmospheric pressure (760 mmHg; i.e. 1 .013 * 10⁵ Pa).

The compound(s) with a Hansen solubility parameter value δΗ as defined previously are, for example, described in the reference publication Hansen solubility parameters: A User's Handbook by Charles M. Hansen, CRC Press, 2000, pages 167 to 185, or in the publication Handbook of Solubility Parameters and Other Cohesion Parameters, CRC Press, pages 95 to 121 and pages 177 to 185.

This solubility parameter value δΗ is associated with the formation of hydrogen bonds. It may be recalled that there are three major types of interaction in organic compounds: non-polar interactions, permanent dipole-dipole interactions and interactions of hydrogen bonding type, the latter forming the subject of the parameter defining the hydrotropic compound present in the composition used in accordance with the invention.

In particular, the book Handbook of Solubility Parameters and Other Cohesion Parameters, CRC Press, pages 95 to 121 and pages 177 to 185, gives the equation δΗ = (∑-^zU_h/V)^1/2

in which

zUh (in J.mol^"1) describes the contributions of the functional group considered in the solubility parameters associated with the hydrogen bonds (values in Table 14, page 183), this parameter ^zU_h also being described in the book The relation between surface tension and solubility parameter in liquids, Bagda, E, Farbe Lack, 84, 212, 1978;

and V is the volume of the molecule.

It should be noted that the solubility parameter value δΗ is usually given for a temperature of 25°C and at atmospheric pressure (760 mmHg, i.e. 1.013 10⁵ Pa).

In particular, the liquid organic compounds with a Hansen solubility parameter value 5H of greater than 0 and less than 16 MPa¹'² are nonionic compounds.

Said liquid organic compound(s) with a Hansen solubility parameter value δΗ of greater than 0 and less than 16 MPa^1/2 may be chosen from:

• alcohol ethers, in particular C1-C4 ethers of C₅-C₃o alcohols, which are preferably saturated, linear or branched, optionally interrupted with one or more non-adjacent ether functions;

• aliphatic esters of Ci-C₄ carboxylic acids and of C₃-Ci₀ monoalcohols or polyhydroxylated, interrupted with one or more non-adjacent ether functions;

• aromatic ethers, in particular of C₆-Ci₀, of a Ci-C₆ alkyl optionally bearing a hydroxyl group,

• (C₆-Cio)aryl(Ci-C₆) alkyl ethers, of a Ci-C₆ alkyl optionally bearing a hydroxyl group,

• alkanols bearing an aryl substituent, preferably for which the aryl part is C6- Cio, advantageously C₆, and the alkyl part of the alkanol is C C₄, this alkyl part possibly ending or being interrupted with a heteroatom, advantageously oxygen or a hydroxyl group, preferably such as benzyl alcohol;

• lactones preferably of formula (iii), and also mixtures thereof, with:

in which R' represents a hydrogen, a linear or branched Ci-C₈ alkyl, a linear or branched Ci-C₄ hydroxyalkyl, n being equal to 1 , 2 or 3, and preferably R' represents a hydrogen, a linear or branched C₁-C6 alkyl or a linear or branched C₁-C₂ hydroxyalkyl.

A particularly advantageous example of lactones that may be mentioned is γ- butyrolactone.

Mention may also be made of certain liquid alkanols, for instance 1-pentanol.

Preferably, said liquid organic compound(s) with a Hansen solubility parameter value δΗ of greater than 0 and less than 16 MPa^1/2 are chosen from alcohol ethers, aliphatic esters, aromatic ethers and alkanols bearing aryl substituents, and mixtures thereof.

Even more preferentially, said liquid organic compound(s) according to the invention are chosen from dipropylene glycol monomethyl ether acetate, dipropylene glycol methyl ether, dipropylene glycol mono-n-butyl ether (the INCI name of which is PPG-2 butyl ether), tripropylene glycol methyl ether, propylene glycol n-butyl ether, propylene glycol n-propyl ether, propylene glycol monomethyl ether, diethylene glycol monomethyl ether and monoethyl ether, 3-phenyl-1- propanol, 2-phenyl-1 -propanol, benzyl alcohol, benzyloxyethanol and phenoxyethanol, and mixtures of these compounds.

The liquid organic compound(s) with a Hansen solubility parameter value δΗ of greater than 0 and less than 16 MPa^1/2 are even more preferentially chosen from alkanols bearing aryl substituents and even more preferentially benzyl alcohol.

The liquid organic compound(s) with a Hansen solubility parameter value δΗ of greater than 0 and less than 16 MPa^{1 2} represent from 0.5% to 35% by weight, preferably from 1 % to 35% by weight, more particularly from 3% to 30% by weight and better still 5% to 25% by weight relative to the total weight of the composition.

Preferably, these preferences concerning the content and nature of the liquid organic compound(s) with a Hansen solubility parameter value δΗ of greater than 0 and less than 16 MPa¹ⁱ² are also preferred, in the case of a ready-to-use oxidation dye composition comprising a mixture of a composition A and of a composition B comprising at least one oxidizing agent.

OILS The composition according to the invention comprises at least one oil, i.e. at least one liquid fatty substance. In particular, the oil(s) are different from the liquid organic compound(s) with a Hansen solubility parameter value δΗ of greater than 0 and less than 16 MPa^1/2 described above.

The term "fatty substance" means an organic compound that is insoluble in water at ordinary temperature (25°C) and at atmospheric pressure (760 mmHg) (solubility of less than 5%, preferably less than 1 % and even more preferentially less than 0.1 %). They bear in their structure at least one hydrocarbon-based 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, for instance chloroform, dichloromethane, carbon tetrachloride, ethanol, benzene, toluene, tetrahydrofuran (THF), liquid petroleum jelly or decamethylcyclopentasiloxane.

The term "ο/Γ means a "fatty substance" that is liquid at room temperature (25°C) and at atmospheric pressure (760 mmHg). In particular, the term "oil" means a non-aqueous, water-immiscible compound, which is liquid at room temperature (25°C) and atmospheric pressure (760 mmHg).

In particular, the oil may be chosen from hydrocarbon-based oils, silicone oils and/or fluoro oils.

In particular, the composition according to the invention comprises at least one non-carbonyl-based oil, i.e. an oil not comprising any carbonyl groups (CO). In particular, the non-carbonyl-based oil therefore does not comprise any carbonyl, carboxylic acid (or salts), ester or amide functions.

The term "hydrocarbon-based oil" means an oil formed essentially from, or even constituted of, carbon and hydrogen atoms, and optionally oxygen and nitrogen atoms, and not containing any silicon or fluorine atoms. It may contain alcohol, ester, ether, carboxylic acid, amine and/or amide groups.

The hydrocarbon-based oil may be chosen in particular from liquid hydrocarbons, oils of animal origin, oils of plant origin, liquid fatty alcohols and liquid fatty ethers.

The term "silicone oif means an oil comprising at least one silicon atom. The term "non-silicone oif means an oil not containing any silicon (Si) atoms.

The term "fluoro oil" means an oil containing at least one fluorine atom.

Preferably, the viscosity at a temperature of 25°C and at a shear rate of 1 s^"1 of the oil is between 10^~3 Pa.s and 2 Pa.s. It may be measured using a Thermo Haake RS600 rheometer with cone-plate geometry or an equivalent machine.

According to a particularly preferred embodiment, the composition (A) according to the invention comprises a total content of non-carbonyl-based oil(s) of between 5% and 70% by weight relative to the total weight of the composition.

Preferably, the composition according to the invention has a total content of non-carbonyl-based oil(s) of between 10% and 40% by weight and better still between 15% and 35% by weight relative to the total weight of the composition. Preferably, the non-carbonyl-based oil(s) according to the invention are chosen from:

- oils with a polarity £ of less than 2.5 with £ corresponding to the dielectric constant at 25°C of the oil, preferably chosen from:

o linear or branched hydrocarbons, of mineral, animal or synthetic origin, which are optionally halogenated, comprising between 6 and 16 carbon atoms, preferably chosen from hexane, cyclohexane, undecane, dodecane, isododecane, tridecane, perfluorohexane and isohexadecane, and mixtures thereof;

o linear or branched hydrocarbons, of mineral or synthetic origin, which are optionally halogenated, comprising more than 16 carbon atoms, preferably chosen from liquid petroleum jelly, polydecene, liquid paraffin or derivatives thereof, squalane, isoeicosane, naphthalene oil, polybutylenes and hydrogenated polyisobutylenes, and mixtures thereof;

o and mixtures thereof;

- saturated or unsaturated, linear or branched liquid fatty alcohols, preferably comprising 6 to 30 carbon atoms, preferably of formula C_nH_2n+iOH with n being an integer between 6 and 30 inclusive; preferably chosen from oleyl alcohol, linolenyl alcohol, linoleyl alcohol, ricinoleyl alcohol, undecylenyl alcohol, isostearyl alcohol and octyldodecanol; and mixtures thereof;

- linear or branched, saturated or unsaturated liquid ethers preferably comprising from 12 to 60 carbon atoms in total, preferably of formula [C_nH_2n+i]20 with n being an integer between 6 and 30 inclusive, for instance distearyl ether;

- and mixtures thereof.

Preferably, the oil(s) are chosen from liquid hydrocarbons, in particular liquid petroleum jelly or isododecane, or from fatty alcohols, in particular octyldodecanol or isostearyl alcohol or mixtures thereof, or alternatively from fatty ethers, such as distearyl ether.

According to a particularly preferred embodiment, the composition according to the invention comprises at least one oil with a polarity £ of less than 2.5, with £ corresponding to the dielectric constant at 25°C of the oil. In particular, oils with a polarity £ of less than 2.5 are conventionally apolar oils.

Preferably, the oil(s) used in the composition according to the invention are non- silicone oils. In a particularly preferred manner, the oil with a polarity £ of less than 2.5 is a linear or branched hydrocarbon, of mineral or synthetic origin, and is preferably chosen from:

- liquid hydrocarbon oils containing from 8 to 16 carbon atoms, and especially: i) branched C₈-Ci₆ alkanes, for instance C₈-Ci₆ isoalkanes of petroleum origin (also known as isoparaffins), for instance isododecane (also known as 2,2,4,4,6-pentamethylheptane), isohexadecane and isodecane and, for example, the oils sold under the trade name Isopar or Permethyl,

ii) linear alkanes, for instance n-dodecane (C12) and n-tetradecane

(C14) sold by Sasol under the respective references Parafol 12-97 and Parafol 14-97, and also mixtures thereof, the undecane-tridecane mixture, the mixtures of n-undecane (C1 1 ) and

of n-tridecane (C13) obtained in Examples 1 and 2 of patent application WO 2008/155 059 from the company Cognis, iii) and mixtures thereof,

linear or branched hydrocarbons, of mineral or synthetic origin, comprising more than 16 carbon atoms, and especially

o liquid paraffin or derivatives thereof,

o squalane,

o isoeicosane,

o liquid petroleum jelly,

o naphthalene oil,

o polybutylenes such as Indopol H-100 (molar mass or MW = 965 g/mol), Indopol H-300 (MW = 1340 g/mol) and Indopol H-1500 (MW

= 2160 g/mol) sold or manufactured by the company Amoco, o hydrogenated polyisobutylenes such as Parleam^® sold by the company Nippon Oil Fats, Panalane H-300 E sold or manufactured by the company Amoco (MW = 1340 g/mol), Viseal 20000 sold or manufactured by the company Synteal (MW = 6000 g/mol) and

Rewopal PIB 1000 sold or manufactured by the company Witco (MW = 1000 g/mol),

o decene/butene copolymers, polybutene/polyisobutene copolymers, especially Indopol L-14,

o polydecenes and hydrogenated polydecenes such as: Puresyn 10

(MW = 723 g/mol) and Puresyn 150 (MW = 9200 g/mol) sold or manufactured by the company Mobil Chemicals,

- and mixtures thereof. Preferably, the oil(s) are liquid hydrocarbons with a polarity £ of less than 2.5 preferably chosen from: C₅-Ci5 alkanes and isoalkanes, preferably such as isododecane, - liquid paraffin or derivatives thereof,

squalane,

isoeicosane,

- liquid petroleum jelly,

naphthalene oil,

polybutylenes,

hydrogenated polyisobutylenes,

decene/butene copolymers and polybutene/polyisobutene copolymers, and

polydecenes and hydrogenated polydecenes,

- and mixtures thereof.

Preferably, the oil(s) used in the composition according to the invention are hydrocarbon-based oils. In a particularly preferred manner, the oil with a polarity £ of less than 2.5 is a hydrocarbon-based oil, preferably a liquid hydrocarbon.

Preferably, the oil with a polarity £ of less than 2.5 is chosen from isododecane and liquid petroleum jelly, and mixtures thereof.

According to an advantageous embodiment of the invention, the composition comprises at least one apolar oil, which is preferably hydrocarbon-based, better still a liquid hydrocarbon.

For the purposes of the present invention, the term "apolar oil" means an oil whose solubility parameter at 25°C, 5_a, is equal to 0 (J/cm³)¹'².

The definition and calculation of the solubility parameters in the Hansen three- dimensional solubility space are described in the article by CM. Hansen: "The three dimensional solubility parameters", J. Paint Technol. 39, 105 (1967).

According to this Hansen space:

- 8_D characterizes the London dispersion forces derived from the formation of dipoles induced during molecular impacts;

- δ_ρ characterizes the Debye interaction forces between permanent dipoles and also the Keesom interaction forces between induced dipoles and permanent dipoles;

- 5_h characterizes the specific interaction forces (such as hydrogen bonding, acid/base, donor/acceptor, etc.); and

- δ₃ is determined by the equation: δ₃ = (δ_ρ ² + 8_h ²)^½.

The parameters δ_ρ, 8_h, 5_D and δ₉ are expressed in MPa^{1 2} or (J/cm³)^½.

Preferably, the apolar hydrocarbon-based oil is free of oxygen atoms.

In a particularly preferred manner, the apolar oil is a liquid hydrocarbon.

According to another embodiment, the non-carbonyl-based oil is chosen from linear or branched, saturated or unsaturated liquid fatty alcohols preferably comprising 6 to 30 carbon atoms, preferably of formula C_nH_2n+iOH with n being an integer between 6 and 30 inclusive, or linear or branched, saturated or unsaturated liquid ethers, preferably comprising 12 to 60 carbon atoms in total, preferably of formula [C_nH_2n+i]₂0 with n being an integer between 6 and 30 inclusive.

These oils generally have a dielectric constant £ of greater than or equal to 2.5.

They are different from the liquid organic compound with a Hansen solubility parameter value δΗ of greater than 0 and less than 16 MPa¹'² described above.

Preferably, according to this embodiment, the non-carbonyl-based oil with a polarity £ of greater than or equal to 2.5 is chosen from:

- alcohols of formula C_nH_2n+iOH with n being an integer between 6 and 20 inclusive, preferably chosen from oleyl alcohol, linolenyl alcohol, linoleyl alcohol, ricinoleyl alcohol, undecylenyl alcohol, isostearyl alcohol and octyldodecanol, and mixtures thereof;

- alcohols of formula C_nH_2n+iOH with n being an integer between 20 and 30 inclusive, which is optionally substituted, in particular with one or more hydroxyl groups (in particular 1 to 4), preferably chosen from benzyl alcohol (1-docosanol), arachidonyl alcohol, arachidyl alcohol (1-eicosanol), erucyl alcohol (cis-13-docosen-1 -ol), n-heneicosanyl alcohol (C21 sat), tricosanyl alcohol (C23sat), lignoceryl alcohol (1 -tetracosanol) (C24sat), pentacosanyl alcohol (C25sat), ceryl alcohol (1 -hexacosanol) (C26 sat lin), montanyl alcohol (1-octacosanol) (C28sat lin), n-nonacosanyl alcohol (C29sat) and n- triacontanyl alcohol (C30sat), and mixtures thereof;

- linear or branched, saturated or unsaturated liquid ethers preferably comprising from 12 to 60 carbon atoms in total, preferably of formula [C_nH_2n+1]₂0 with n being an integer between 6 and 30 inclusive, for instance distearyl ether;

- and mixtures thereof.

According to one embodiment, the non-carbonyl-based oil is chosen from linear or branched, saturated or unsaturated liquid fatty alcohols preferably comprising from 6 to 20 carbon atoms, preferably of formula C_nH .iOH with n being an integer between 6 and 20 inclusive; preferably chosen from oleyl alcohol, linoleyl alcohol, linolenyl alcohol, ricinoleyl alcohol, undecylenyl alcohol, isostearyl alcohol and octyldodecanol; and mixtures thereof.

According to another embodiment, the non-carbonyl-based oil is chosen from linear or branched, saturated or unsaturated liquid ethers preferably comprising from 12 to 60 carbon atoms in total, preferably of formula [C_nH_2n+i]₂0 with n being an integer between 6 and 30 inclusive, in particular distearyl ether;

ADDITIONAL OILS The composition according to the invention may also comprise at least one additional oil, other than the non-carbonyl-based oils mentioned previously.

In particular, the composition according to the invention may also comprise at least one carbonyl-based oil.

Preferably, said carbonyl-based oil is an ester oil (i.e. an oil comprising at least one ester function).

Preferably, the non-carbonyl-based oil is chosen from:

^■ ester oils chosen from triglycerides of plant or synthetic origin; preferably chosen from liquid fatty acid triglycerides comprising from 6 to 30 carbon atoms, for instance heptanoic or octanoic acid triglycerides, or alternatively, for example, sunflower oil, corn oil, soybean oil, pumpkin 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 ester oils other than triglycerides, for instance liquid esters of fatty acids and/or of fatty alcohols;

^■ and mixtures thereof.

The term "ester oil" means an oil comprising at least one ester function.

Preferably, said ester oil is chosen from triglycerides of plant or synthetic origin; preferably chosen from liquid fatty acid triglycerides comprising from 6 to 30 carbon atoms, for instance heptanoic or octanoic acid triglycerides, or alternatively, for example, sunflower oil, corn oil, soybean oil, pumpkin 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.

These esters are preferably liquid esters of saturated or unsaturated, linear or branched Ci-C₂6 aliphatic monoacids or polyacids and of saturated or unsaturated, linear or branched C₁-C26 aliphatic monoalcohols or polyalcohols, the total number of carbon atoms of 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 monocarboxylic, dicarboxylic or tricarboxylic acids and of non-sugar C₄- C₂6 dihydroxy, trihydroxy, tetrahydroxy or pentahydroxy alcohols may also be used.

Mention may be made in particular of: diethyl sebacate; diisopropyl sebacate; diisopropyl adipate; di-n-propyl adipate; dioctyl adipate; diisostearyl adipate; dioctyl maleate; glyceryl undecylenate; octyldodecyl stearoyl stearate; pentaerythrityl monoricinoleate; pentaerythrityl tetraisononanoate; pentaerythrityl tetrapelargonate; pentaerythrityl 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.

Among the esters mentioned above, it is preferred to use 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, propylene glycol dicaprylate, butyl stearate, isobutyl stearate; dioctyl malate, hexyl laurate, 2-hexyldecyl laurate, isononyl isononanoate or cetyl octanoate.

The composition may also comprise, as liquid fatty ester, sugar esters and diesters of C₆-C₃o and preferably C12-C22 fatty acids. It is recalled that the term "sugar" means oxygen-bearing hydrocarbon-based compounds containing several alcohol functions, with or without aldehyde or ketone functions, and which comprise at least 4 carbon atoms. These sugars may be monosaccharides, oligosaccharides or polysaccharides.

Examples of suitable sugars that may be mentioned include sucrose, 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 and fatty acid esters may be chosen in particular from the group comprising the esters or mixtures of sugar esters described previously and of linear or branched, saturated or unsaturated C₆-C₃o and preferably C12-C22 fatty acids. If they are unsaturated, these compounds may comprise one to three conjugated or unconjugated carbon-carbon double bonds.

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

These esters may be, for example, oleates, laurates, palmitates, myristates, behenates, cocoates, stearates, linoleates, linolenates, caprates or arachidonates, or mixtures thereof, such as, especially, oleopalmitate, oleostearate or palmitostearate mixed esters. More particularly, use is made of monoesters and diesters and especially of sucrose, glucose or methylglucose mono- or dioleates, stearates, behenates, oleopalmitates, linoleates, linolenates or oleostearates.

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

The carbonyl-based oil, if it is present, may be present in a content of less than 50% by weight, preferably less than 30% by weight and better still less than 10% by weight relative to the total weight of the composition.

The carbonyl-based oil, if it is present, is preferably present in a content of less than 5% by weight, relative to the total weight of the composition.

According to a particular embodiment, the composition according to the invention does not comprise any additional oils. In particular, preferably, the composition according to the invention does not comprise any carbonyl-based oil. ADDITIONAL SOLVENTS

The composition according to the invention may also comprise one or more additional organic solvents other than oils and liquid organic compounds with a Hansen solubility parameter value δΗ of greater than 0 and less than 16 MPa¹'².

Examples of additional organic solvents that may be mentioned include linear or branched C₂-C₄ alkanols, such as ethanol and propanol; glycerol; short-chain polyols such as propylene glycol and dipropylene glycol, and mixtures thereof.

The additional solvent(s), if they are present, represent a content usually ranging from 1 % to 40% by weight and preferably from 5% to 30% by weight relative to the total weight of the composition.

Composition (A) according to the invention comprises water. In the case of an oxidation dye composition, the ready-to-use composition according to the invention mixture of composition (A) and of a composition (B) also comprises water.

These compositions optionally comprise one or more cosmetically acceptable organic solvents.

Preferably, the composition according to the invention comprises at least 5% by weight of water, relative to the weight of this composition. Preferably, the ready-to-use composition, if it is different from the composition according to the invention, comprises at least 5% by weight of water, relative to the weight of this composition.

Preferably, the composition according to the invention comprises at least 10% by weight of water and even more advantageously at least 20% by weight of water, relative to the weight of this composition. Preferably, composition (A) and composition (B) (when it exists), and/or the ready-to-use oxidation dye composition (mixture of compositions A and B) contain water in a content ranging from 10% to 70% and better still from 20% to 55% of the total weight of the composition, relative to the total weight of each composition.

Preferably, according to this embodiment, compositions A and/or B, and/or the mixture of compositions A and B, are all in the form of a microemulsion.

THE SURFACTANTS:

The composition according to the invention uses one or more surfactants.

In particular, the surfactant(s) are chosen from nonionic surfactants or from anionic, amphoteric, zwitterionic, cationic or nonionic surfactants, and preferentially nonionic surfactants.

The term "anionic surfactant' means a surfactant comprising, as ionic or ionizable groups, only anionic groups. These anionic groups are preferably chosen from the groups -C(0)OH, -C(0)0^", -S0₃H, -S(0)₂0^", -OS(0)₂OH, -OS(0)₂0^_, - P(0)OH₂, -P(0)₂0^", -P(0)0₂ ^", -P(OH)₂, =P(0)OH, -P(OH)0^", =P(0)0^" and =POH, =PO^", the anionic parts comprising a cationic counterion such as an alkali metal, an alkaline-earth metal or an ammonium.

According to a first embodiment, the surfactant(s) are chosen from anionic surfactants.

Preferably, the anionic surfactant is chosen from alkyl sulfates, alkyl ether sulfates, alkylamido ether sulfates, alkylaryl polyether sulfates, monoglyceride sulfates, alkyl sulfonates, alkylamide sulfonates, alkylaryl sulfonates, alpha-olefin sulfonates, paraffin sulfonates, alkyl sulfosuccinates, alkyl ether sulfosucci nates, alkylamide sulfosuccinates, alkyl sulfoacetates, acyl sarcosinates, acyl glutamates, alkyl sulfosuccinamates, acyl isothionates and N-acyl taurates; salts of alkyl monoesters of polyglycoside-polycarboxylic acids, acyl lactylates, salts of D- galactosiduronic acids, salts of alkyl ether carboxylic acids, salts of alkylaryl ether carboxylic acids, salts of alkylamido ether carboxylic acids; and the corresponding non-salified 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 and mixtures thereof.

These compounds can be oxyethylenated and then preferably comprise from 1 to 50 ethylene oxide units.

The salts of C₆-C₂₄ alkyl monoesters of polyglycoside-polycarboxylic acids may be chosen from C₆-C₂₄ alkyl polyglycoside-citrates, C₆-C₂₄ alkyl polyglycoside- tartrates and C₆-C₂₄ alkyl polyglycoside-sulfosuccinates.

When the anionic surfactant(s) are in salt form, they may be chosen from alkali metal salts such as the sodium or potassium salt and preferably the sodium salt, ammonium salts, amine salts and in particular amino alcohol salts or alkaline-earth metal salts such as the magnesium salts. Examples of amino alcohol salts that may especially be mentioned include monoethanolamine, diethanolamine and triethanolamine salts, monoisopropanolamine, diisopropanolamine or triisopropanolamine salts, 2-amino-2- methyl-1 -propanol salts, 2-amino-2-methyl-1 ,3-propanediol salts and tris(hydroxymethyl)aminomethane salts.

Alkali metal or alkaline-earth metal salts and in particular the sodium or magnesium salts are preferably used.

Among the anionic surfactants mentioned, use is preferably made of (C₆- C24)alkyl sulfates, (C6-C24)alkyl ether sulfates comprising from 2 to 50 ethylene oxide units, especially in the form of alkali metal, ammonium, amino alcohol and alkaline- earth metal salts, or a mixture of these compounds.

In particular, it is preferred to use (Ci₂-C₂o)alkyl sulfates, (Ci₂-C₂o)alkyl ether sulfates comprising from 2 to 20 ethylene oxide units, especially in the form of alkali metal, ammonium, amino alcohol and alkaline-earth metal salts, or a mixture of these compounds. Better still, it is preferred to use sodium lauryl ether sulfate containing 2.2 mol of ethylene oxide.

Preferably, the anionic surfactant(s) are chosen from alkyl sulfates, alkyl ether sulfates and mixtures thereof; and mixtures thereof.

The amphoteric or zwitterionic surfactant(s), which are preferably non-silicone, which can be used in the present invention may especially be derivatives of optionally quaternized aliphatic secondary or tertiary amines, in which derivatives the aliphatic group is a linear or branched chain comprising from 8 to 22 carbon atoms, said amine derivatives containing at least one anionic group, for instance a carboxylate, sulfonate, sulfate, phosphate or phosphonate group. Mention may be made in particular of (C₈-C₂o)alkyl betaines, sulfobetaines, (C₈-C2o)alkylamido(C3-C₈)alkyl betaines and (C₈-C₂o)alkylamido(C₆-C8)alkyl sulfobetaines.

Among the optionally quaternized secondary or tertiary aliphatic amine derivatives that may be used, as defined above, mention may also be made of the compounds of respective structures (A1) and (A2) below:

R_a-C(0)-NH-CH₂-CH₂-N⁺(R_b)(R_c)-CH₂C(0)0-, M⁺

(A1 ) in which formula (A1):

^■ R_a represents a Ci₀-C₃₀ alkyl or alkenyl group derived from an acid R_a-

COOH preferably present in hydrolysed copra oil, or a heptyl, nonyl or undecyl group;

■ R_b represents a β-hydroxyethyl group; and

^■ R_c represents a carboxymethyl group; ^■ M⁺ represents a cationic counterion derived from an alkali metal or alkaline-earth metal, such as sodium, an ammonium ion or an ion derived from an organic amine, and R_a-C(0)-NH-CH₂-CH₂-N(B)(B') (A2) in which formula (A2):

^■ B represents the group -CH₂-CH₂-0-X';

^■ B' represents the group -(CH₂)_ZY', with z = 1 or 2;

- X" represents the group -CH₂-C(0)OH, -CH₂-C(0)OZ\ -CH₂-CH₂-C(0)OH or

-CH₂-CH₂-C(0)OZ', or a hydrogen atom;

■ V represents the group -C(0)OH, -C(0)OZ', -CH₂-CH(OH)-S0₃H or the group -CH₂-CH(OH)-S0₃-Z';

^■ Z' represents a cationic counterion derived from an alkali metal or alkaline- earth metal, such as sodium, an ammonium ion or an ion derived from an organic amine;

^■ R_a' represents a Cio-C₃₀ alkyl or alkenyl group of an acid R_a-C(0)OH preferably present in copra oil or in hydrolysed linseed oil, an alkyl group, especially of d₇ and its iso form, or an unsaturated Ci₇ group.

These compounds are classified in the CTFA dictionary, 5th edition, 1993, under the names disodium cocoamphodiacetate, disodium lauroamphodiacetate, disodium caprylamphodiacetate, disodium capryloamphodiacetate, disodium cocoamphodipropionate, disodium lauroamphodipropionate, disodium caprylamphodipropionate, disodium capryloamphodipropionate, lauroamphodipropionic acid and cocoamphodipropionic acid.

By way of example, mention may be made of the cocoamphodiacetate sold by the company Rhodia under the trade name Miranol^® C2M Concentrate.

Among the amphoteric or zwitterionic surfactants mentioned above, use is preferably made of (C₈-C₂o)alkylbetaines such as cocoylbetaine, and (C₈- C₂o)alkylamido(C₃-C8)alkylbetaines such as cocamidopropylbetaine, and mixtures thereof. More preferentially, the amphoteric or zwitterionic surfactant(s) are chosen from cocamidopropylbetaine and cocoylbetaine.

The cationic surfactant(s) that may be used in the composition according to the invention comprise, for example, optionally polyoxyalkylenated primary, secondary or tertiary fatty amine salts, quaternary ammonium salts, and mixtures thereof.

Examples of quaternary ammonium salts that may especially be mentioned include:

- those corresponding to general formula (I) below: R,

X

R,

(I)

in which formula (I) the groups R₈ to Rn, which may be identical or different, each represent a linear or branched aliphatic group comprising from 1 to 30 carbon atoms or an aromatic group such as aryl or alkylaryl, at least one of the groups s to n comprising from 8 to 30 carbon atoms and preferably from 12 to 24 carbon atoms. The aliphatic groups may comprise heteroatoms such as, in particular, oxygen, nitrogen, sulfur and halogens.

The aliphatic groups are chosen, for example, from CrC₃₀ alkyl, Ci-C₃₀ alkoxy, polyoxy(C₂-C₆)alkylene, C1-C30 alkylamide, (Ci2-C22)alkylamido(C₂-C₆)alkyl, (Ci₂- C₂2)alkyl acetate, and Ci-C₃₀ hydroxyalkyl groups, X^" is an anionic counterion chosen from halides, phosphates, acetates, lactates, (CrC₄)alkyl sulfates, and (CrC₄)alkyl- or (Ci-C₄)alkylarylsulfonates.

Among the quaternary ammonium salts of formula (I), preference is given firstly to tetraalkylammonium chlorides, for instance dialkyldimethylammonium or alkyltrimethylammonium chlorides in which the alkyl group contains approximately from 12 to 22 carbon atoms, in particular behenyltrimethylammonium chloride, distearyldimethylammonium chloride, cetyltnmethylammonium chloride, benzyldimethylstearylammonium chloride, or else, secondly, distearoylethylhydroxyethylmethylammonium methosulfate, dipalmitoylethylhydroxyethylammonium methosulfate or distearoylethylhydroxyethylammonium methosulfate, or else, lastly, palmitylamidopropyltrimethylammonium chloride or stearamidopropyldimethyl(myristyl acetate)ammonium chloride, sold under the name Ceraphyl® 70 by the company Van Dyk;

- quaternary ammonium salts of imidazoline, for instance those of formula (II) below:

(ll)

in which formula (II) Ri₂ represents an alkenyl or alkyl group containing from 8 to 30 carbon atoms, for example tallow fatty acid derivatives, R_i3 represents a hydrogen atom, a C1-C4 alkyl group or an alkenyl or alkyl group containing from 8 to 30 carbon atoms, R_i represents a CrC₄ alkyl group, Ri₅ represents a hydrogen atom or a C C₄ alkyl group, and X^" represents an anionic counterion chosen from halides, phosphates, acetates, lactates, (CrC₄)alkyl sulfates, and (Ci-C₄)alkyl- or (Ci-C₄)alkylarylsulfonates. Preferably, Ri₂ and Ri₃ denote a mixture of alkenyl or alkyl groups comprising from 12 to 21 carbon atoms, for example derived from tallow fatty acids, R_M denotes a methyl group and Ri₅ denotes a hydrogen atom. Such a product is sold, for example, under the name Rewoquat® W 75 by the company Rewo;

quaternary diammonium or triammonium salts, particularly of formula (IV) below:

(III)

in which formula (III) R₁₆ denotes an alkyl group containing approximately from 16 to 30 carbon atoms, which is optionally hydroxylated and/or interrupted with one or more oxygen atoms; R17 is chosen from hydrogen, an alkyl group containing from 1 to 4 carbon atoms or a group -(CH₂)3-N⁺( i6a)(Ri7a)( i8a); R16a, Ri_7a, Rise, R-I8, i9, R20 and R₂i , which may be identical or different, are chosen from hydrogen and an alkyl group containing from 1 to 4 carbon atoms, and X^" represents an anionic counterion chosen from halides, acetates, phosphates, nitrates, (CrC₄)alkyl sulfates, and (CrC₄)alkyl- or (d- C₄)alkylarylsulfonates, in particular methyl sulfate and ethyl sulfate. Such compounds are, for example, Finquat CT-P, sold by the company Finetex (Quaternium 89), and Finquat CT, sold by the company Finetex (Quaternium 75);

- quaternary ammonium salts comprising one or more ester functions, such as those of formula (IV) below:

O

/

+

R 24 0-C_rH_r2(OH), C_tH_t2(OH)_t-0- R '2. 3

R 22

(IV)

in which formula (IV):

■ R₂2 is chosen from Ci-C₆ alkyl groups and Ci-C₆ hydroxyalkyl or Ci-C₆ dihydroxyalkyl groups; R23 is chosen from:

- the group

- saturated or unsaturated and linear or branched C1-C22 hydrocarbon- based groups R27,

- a hydrogen atom,

R25 is chosen from:

- the group

- saturated or unsaturated and linear or branched Ci-C₆ hydrocarbon- based groups R₂g,

- a hydrogen atom,

^■ R24, R26 and R28, which may be identical or different, are chosen from linear or branched, saturated or unsaturated C7-C21 hydrocarbon-based groups,

^■ r, s and t, which may be identical or different, are integers ranging from 2 to 6,

^■ r1 and t1 , which may be identical or different, are equal to 0 or 1 , with r2+r1 =2r and t1 +t2=2t,

^■ y is an integer ranging from 1 to 10,

^■ x and z, which may be identical or different, are integers ranging from 0 to

10,

^■ X^" represents an organic or mineral anionic counterion,

with the proviso that the sum x + y + z is from 1 to 15, that when x is 0 then R₂3 denotes R27, and that when z is 0 then R25 denotes R₂g.

The alkyl groups R22 may be linear or branched, and more particularly linear.

Preferably, R₂₂ denotes a methyl, ethyl, hydroxyethyl or dihydroxypropyl group, and more particularly a methyl or ethyl group.

Advantageously, the sum x + y + z is from 1 to 10.

When R23 is a hydrocarbon-based group R27, it may be long and contain from 12 to 22 carbon atoms, or may be short and contain from 1 to 3 carbon atoms.

When R₂₅ is a hydrocarbon-based group R29, it preferably contains 1 to 3 carbon atoms.

Advantageously, R24, R₂6 and R₂8, which may be identical or different, are chosen from linear or branched, saturated or unsaturated C11-C21 hydrocarbon- based groups, and more particularly from linear or branched, saturated or unsaturated Cn-C₂i alkyl and alkenyl groups.

Preferably, x and z, which may be identical or different, have the value 0 or 1.

Advantageously, y is equal to 1 . Preferably, r, s and t, which may be identical or different, are equal to 2 or 3, and even more particularly are equal to 2.

The anionic counterion X^' is preferably a halide, preferably such as chloride, bromide or iodide; a (Ci-C₄)alkyl sulfate or a (CrC₄)alkyl- or (Ci- C4)alkylarylsulfonate. However, use may be made of methanesulfonate, phosphate, nitrate, tosylate, an anion derived from an organic acid, such as acetate or lactate, or any other anion that is compatible with the ammonium bearing an ester functional group.

The anionic counterion X^" is even more particularly chloride, methyl sulfate or ethyl sulfate.

Use is made more particularly, in the composition according to the invention, of the ammonium salts of formula (IV) in which:

- R₂2 denotes a methyl or ethyl group,

- x and y are equal to 1 ,

- z is equal to 0 or 1 ,

- r, s and t are equal to 2,

- R23 is chosen from: the group

• methyl, ethyl or C14-C₂₂ hydrocarbon-based groups,

• a hydrogen atom,

- R25 is chosen from:

O

· the group J]

• a hydrogen atom,

- R24, 26 and R₂e, which may be identical or different, are chosen from linear or branched, saturated or unsaturated C13-C17 hydrocarbon- based groups, and preferably from linear or branched, saturated or unsaturated C13-C17 alkyl and alkenyl groups.

Advantageously, the hydrocarbon-based radicals are linear. Among the compounds of formula (V), examples that may be mentioned include salts, especially the chloride or methyl sulfate, of diacyloxyethyldimethylammonium, diacyloxyethylhydroxyethylmethylammonium, monoacyloxyethyldihydroxyethylmethylammonium, triacyloxyethylmethylammonium or monoacyloxyethylhydroxyethyldimethylammonium, and mixtures thereof. The acyl groups preferably contain 14 to 18 carbon atoms and are obtained more particularly from a plant oil such as palm oil or sunflower oil. When the compound comprises several acyl groups, the latter can be identical or different.

These products are obtained, for example, by direct esterification of triethanolamine, triisopropanolamine, an alkyldiethanolamine or an alkyldiisopropanolamine, which are optionally oxyalkylenated, with fatty acids or with fatty acid mixtures of plant or animal origin, or by transesterification of the methyl esters thereof. This esterification is followed by a quaternization by means of an alkylating agent such as an alkyl halide, preferably methyl or ethyl halide, a dialkyl sulfate, preferably dimethyl or diethyl sulfate, methyl methanesulfonate, methyl para-toluenesulfonate, glycol chlorohydrin or glycerol chlorohydrin.

Such compounds are sold, for example, under the names Dehyquart® by the company Henkel, Stepanquat® by the company Stepan, Noxamium® by the company Ceca or Rewoquat® WE 18 by the company Rewo-Witco.

The composition according to the invention may contain, for example, a mixture of quaternary ammonium monoester, diester and triester salts with a weight majority of diester salts.

It is also possible to use the ammonium salts containing at least one ester function that are described in patents US-A-4 874 554 and US-A-4 137 180.

Use may be made of behenoylhydroxypropyltrimethylammonium chloride sold by KAO under the name Quatarmin BTC 131.

Preferably, the ammonium salts comprising at least one ester functional group comprise two ester functional groups.

Among the cationic surfactants that may be present in the composition according to the invention, it is more particularly preferred to choose cetyltrimethylammonium, behenyltrimethylammonium and dipalmitoylethyl- hydroxyethylmethylammonium salts, and mixtures thereof, and more particularly behenyltrimethylammonium chloride, cetyltrimethylammonium chloride, and dipalmitoylethylhydroxyethylammonium methosulfate, and mixtures thereof.

Examples of nonionic surfactants that may be used in the composition used according to the invention are described, for example, in the Handbook of Surfactants by M.R. Porter, published by Blackie & Son (Glasgow and London), 1991 , pp. 1 16-178.

Examples of nonionic surfactants that may be mentioned include the following nonionic surfactants:

- oxyalkylenated (C₈-C₂4)alkylphenols;

- saturated or unsaturated, linear or branched, oxyalkylenated or glycerolated C8-C40 alcohols, comprising one or two fatty chains; - saturated or unsaturated, linear or branched, oxyalkylenated C₈-C₃o fatty acid amides;

- esters of saturated or unsaturated, linear or branched, C₈-C₃o acids and of polyethylene glycols;

- preferably oxyethylenated esters of saturated or unsaturated, linear or branched, C₈-C₃o acids and of sorbitol;

- fatty acid esters of sucrose;

- (C₆-C₃o)alkyl(poly)glucosides, (C₈-C₃₀)alkenyl(poly)glucosides, which are optionally oxyalkylenated (0 to 10 oxyalkylene units) and comprising from 1 to 15 glucose units, (C₈-C₃₀)alkyl (poly)glucoside esters;

- saturated or unsaturated, oxyethylenated plant oils;

- condensates of ethylene oxide and/or of propylene oxide, inter alia, alone or as mixtures;

N-(C₈-C₃₀)alkylglucamine and N-(C₈-C₃₀)acylmethylglucamine derivatives;

- aldobionamides;

- amine oxides;

- oxyethylenated and/or oxypropylenated silicones;

- and mixtures thereof.

The oxyalkylene units are more particularly oxyethylene or oxypropylene units, or a combination thereof, preferably oxyethylene units.

The number of moles of ethylene oxide and/or propylene oxide preferably ranges from 1 to 250, more particularly from 2 to 100 and better still from 2 to 50; the number of moles of glycerol ranges especially from 1 to 50 and better still from 1 to 10.

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

As examples of glycerolated nonionic surfactants, use is preferably made of monoglycerolated or polyglycerolated C₈-C₄₀ alcohols, comprising from 1 to 50 mol of glycerol and preferably from 1 to 10 mol of glycerol.

As examples of compounds of this type, 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. Among the glycerolated alcohols, it is more particularly preferred to use the C₈/Cio alcohol containing 1 mol of glycerol, the Ci₀/Ci₂ alcohol containing 1 mol of glycerol and the C-|₂ alcohol containing 1 .5 mol of glycerol.

The nonionic surfactant(s) according to the invention are preferentially chosen from:

- oxyethylenated C₈-C₄o alcohols comprising from 1 to 100 mol of ethylene oxide, preferably from 2 to 50 and more particularly from 2 to 40 mol of ethylene oxide and comprising one or two fatty chains;

- (C₆-C₃₀)alkyl(poly)glucosides, which are optionally oxyalkylenated (0 to 10 OE) and comprising 1 to 15 glucose units;

- and mixtures thereof.

Even more preferentially, the nonionic surfactant(s) according to the invention are chosen from:

- saturated or unsaturated, linear or branched, oxyalkylenated C₈-C₄o alcohols comprising one or two fatty chains, especially saturated or unsaturated, linear or branched C₈-C₄o alcohols, comprising from 1 to 10 oxyethylene (OE), especially such as stearyl alcohol comprising from 1 to 10 OE;

- (C₆-C₃o)alkyl(poly)glucosides, especially cocoyl glucoside;

- and mixtures thereof.

Preferably, the composition according to the invention comprises at least one anionic surfactant and at least one nonionic surfactant.

Preferably, according to this embodiment, the nonionic surfactant is chosen from saturated or unsaturated, linear or branched C₈-C₄₀ alcohols, comprising from 1 to 10 oxyethylene (OE) and (C₆-C₃₀) alkyl(poly)glucosides, and mixtures thereof. Preferably, according to this embodiment, the anionic surfactant is chosen from alkyl sulfates and alkyl ether sulfates, and mixtures thereof.

Preferably, in the composition (A) according to the invention, the total content of surfactant(s) preferably ranges from 0.1 % to 50% by weight, even better still from 1 % to 30% by weight and better still from 5% to 19% by weight, relative to the total weight of the composition under consideration.

Particularly preferably, the compositon according to the invention comprises at least one nonionic surfactant and at least one anionic surfactant.

Preferably, these preferences concerning the content and nature of the surfactants are also preferred, in the case of a ready-to-use oxidation dye composition comprising a mixture of a composition A and of a composition B comprising at least one oxidizing agent. In the case where composition A comprises at least one oxidation dye, then the dyeing process according to the invention uses at least one composition (B) comprising at least one oxidizing agent. In this case, composition (B) may optionally comprise at least one surfactant. If it contains at least one surfactant, their total content in composition (B) may range from 0.1 % to 50% by weight, better still from 1 % to 30% by weight and more preferentially 5% to 20% by weight relative to the total weight of composition B.

Thus, according to a particular embodiment of the invention, the microemulsion according to the invention has the advantage of comprising a limited content of emulsifiers, and especially of surfactants, while at the same time remaining stable over time.

Such a composition thus has the advantage of limiting the abovementioned drawbacks associated with a very high concentration of emulsifiers.

The composition according to the invention comprises water. Preferably, the composition according to the invention comprises a total water content of between 5% and 90% by weight, more particularly from 10% to 80% by weight and better still from 20% to 70% by weight, relative to the weight of the composition.

Preferably, the composition according to the invention comprises:

- a total content of surfactant(s) of between 0.1 % and 50% by weight, relative to the total weight of the composition;

- a total content of oil(s) of between 5% and 70% by weight, relative to the weight of the composition;

- a total content of water of between 5% and 90% by weight, relative to the total weight of the composition; and

- a total content of liquid organic compound(s) with a Hansen solubility parameter value δΗ of greater than 0 and less than 16 MPa^1/2 of between 1 % and 35% by weight, relative to the weight of the composition.

More preferably, the composition according to the invention comprises:

- a total content of surfactant(s) of between 1 % and 18% by weight, relative to the total weight of the composition;

- a total content of oil(s) of between 10% and 40% by weight, relative to the total weight of the composition;

- a total content of water of between 10% and 80% by weight, relative to the total weight of the composition; and

- a total content of liquid organic compound(s) with a Hansen solubility parameter value δΗ of greater than 0 and less than 16 MPa^1/2 of between 3% and 30% by weight, relative to the weight of the composition.

In a particularly preferred manner, the composition according to the invention comprises:

- a total content of surfactant(s) of between 5% and 19% by weight, relative to the total weight of the composition;

- a total content of oil(s) of between 15% and 35% by weight, relative to the total weight of the composition;

- a total content of water of between 20% and 70% by weight, relative to the total weight of the composition; and

- a total content of liquid organic compound(s) with a Hansen solubility parameter value δΗ of greater than 0 and less than 16 MPa^1/2 of between 5% and 25% by weight, relative to the weight of the composition.

Other additives:

The composition according to the invention may also contain various adjuvants conventionally used in compositions for dyeing the hair, such as anionic, cationic, nonionic, amphoteric or zwitterionic polymers or mixtures thereof; antioxidants; penetrants; sequestrants; fragrances; dispersants; film-forming agents; ceramides; preserving agents; opacifiers.

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

The composition according to the invention may be in various forms, in particular in the form of a liquid, a cream or a gel.

(I) PROCESS A subject of the invention is also a process for dyeing or lightening keratin fibres using a composition (A) as defined above.

The dyeing or lightening process according to the invention thus consists in applying a composition A to wet or dry keratin fibres.

According to a first embodiment, the invention relates to a direct dyeing process comprising the application of a dye composition A'" to keratin fibres.

According to a second embodiment, the invention relates to a lightening process comprising the application of a dye composition A' to keratin fibres.

According to a third embodiment, the invention relates to an oxidation dyeing process, comprising a first step of mixing a composition A" and a composition B, followed by a step of applying to wet or dry human keratin fibres, the mixture of the two compositions (A) and (B) being prepared just before use, particularly between 1 second and 15 minutes before use, preferentially 5 minutes before use.

According to a fourth embodiment, the invention relates to a lightening and/or dyeing process comprising the application of an alkaline composition A"" to keratin fibres.

When the process according to the invention is solely a lightening process, it does not incorporate a direct dye or an oxidation dye precursor (bases and couplers) usually used for the dyeing of human keratin fibres, or alternatively, if it does use direct dyes, the total content of said dyes does not exceed 0.001 % by weight relative to the weight of the composition once the mixing of (A) and (B) has been performed. Specifically, at such a content, only the composition derived from the mixing of (A) and (B) would possibly be dyed, i.e. no dyeing effect would be observed on the keratin fibres.

Preferentially, composition (A) does not contain any oxidation bases, coupler or direct dye when the process of the invention is solely a process for lightening keratin fibres.

According to another particular embodiment of the invention, the process is a process for dyeing keratin fibres using the mixture of parts (A) and (B) as defined previously. When the process according to the invention is a process for dyeing keratin fibres, this process comprises the application of a composition A as defined previously comprising at least one colouring agent, more particularly chosen from direct dyes or oxidation dye precursors, to the keratin fibres. Preferably, such a process uses at least one colouring agent and more particularly direct dyes or oxidation dye precursors on the keratin fibres.

In this embodiment, composition A may be applied in the presence of an oxidizing agent as defined above, which may be provided by an oxidizing composition B.

Preferably, a subject of the invention is a process for dyeing keratin fibres, comprising the application of a composition A as defined previously, comprising at least one colouring agent, in the presence of an oxidizing agent.

Preferentially, composition (A) contains at least one compound chosen from oxidation bases, couplers and/or direct dyes. Thus, according to one embodiment, the invention relates to a dyeing process comprising the application to keratin fibres of a composition (A) comprising at least one direct dye (composition (A'")), optionally in the presence of an oxidizing agent. According to another embodiment, the invention relates to a dyeing process comprising the application to keratin fibres of a composition (A) comprising at least one oxidation dye (composition (A")), in the presence of an oxidizing agent.

In particular, the oxidizing agent is provided by a composition B comprising an oxidizing agent.

Thus, according to a specific embodiment, the process according to the invention comprises a first step of mixing a composition A" and a composition B, followed by a step of applying to wet or dry human keratin fibres, the mixture of the two compositions (A") and (B) being prepared just before use, particularly between 1 second and 15 minutes before use, preferentially 5 minutes before use.

In particular, according to this embodiment, a composition (A) as defined previously, in which compound v) is at least one oxidation dye, and a composition (B) comprising at least one oxidizing agent are mixed.

Preferably, the composition resulting from the mixing of composition (A) and composition (B) is also in the form of a microemulsion.

Even more preferentially, compositions (A) and (B) are in the form of microemulsions, and the composition resulting from the mixing of composition (A) and composition (B) is also in the form of a microemulsion.

Preferably, composition (A) is a bicontinuous microemulsion.

In this variant, compositions (A) and (B) are preferably mixed together in a weight ratio (A)/(B) ranging from 0.2 to 10 and better still from 0.5 to 2.

Composition A or the composition derived from the mixing of (A) and (B) may be applied to wet or dry keratin fibres. Composition (A) or the composition derived from the mixing of (A) and (B) according to the invention is then left in place for a time usually ranging from one minute to one hour and preferably from 5 minutes to 30 minutes.

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

After the treatment, the human keratin fibres are optionally rinsed with water. They may optionally be washed with a shampoo, followed by rinsing with water, before being dried or left to dry. Compositions (A), (Α'), (A"), (A""), (A"") and/or (B) according to the invention and the ready-to-use composition of the oxidation dyeing process (mixture of A" and B) may be in various forms, such as in the form of liquids, creams or gels, or in any other form that is suitable for dyeing keratin fibres, and especially human hair.

Advantageously, compositions (A) and/or (B) and the ready-to-use composition of the process according to the invention are in the form of a gel or cream.

Preferably, the ready-to-use composition resulting from the mixing of compositions (A) and (B) is in the form of a microemulsion.

The pH of the composition after mixing compositions (A) and (B) of the process according to the invention is advantageously between 3 and 12, preferably between 5 and 1 1 and preferentially between 7 and 1 1 , limits inclusive.

It may be adjusted to the desired value by means of acidifying or basifying agents usually used in the dyeing of keratin fibres, or alternatively using standard buffer systems.

The alkaline agents are, for example, those described previously.

Examples of acidifying agents that may be mentioned include mineral or organic acids, for instance hydrochloric acid, orthophosphoric acid, carboxylic acids, for instance tartaric acid, citric acid or lactic acid, or sulfonic acids.

Method for preparing the composition according to the invention and, if it is different, the readv-to-use composition derived from the mixing of (A) and (B)

The ingredients of composition (A) according to the invention or of the abovementioned compositions (A) and (B) and the contents thereof are determined as a function of the characteristics detailed previously for the composition derived from the final mixture of (A) and (B) according to the invention.

Composition (A) according to the invention is in the form of a microemulsion.

Preferably, the composition according to the invention is transparent. Composition (A) according to the invention is obtained by mixing using a magnetic bar.

When it is different from the composition (A), the ready-to-use composition is also in the form of a microemulsion. According to this embodiment, composition (B) intended to be mixed with composition A" just before use is preferably also in the form of a microemulsion.

Composition (A") and composition B, if it is also in the form of a microemulsion, are also prepared by mixing using a magnetic bar. The microemulsions obtained are also stable (i.e. they remain homogeneous for at least 2 months at 45°C).

Preferably, the mixtures of compositions (A") and (B) are in the form of a microemulsion.

The composition (A")/composition (B) weight ratio in the mixture preferably ranges from 0.2 to 2, better still from 0.3 to 1 and even better still from 0.5 to 1.

According to a particular embodiment of the invention, the mixture of (A") and (B) is prepared by placing composition (A") and composition (B) together in a container and mixing them, preferentially vigorously, for a few seconds to a few minutes, before application to the keratin fibres. This mixing may be performed using a multi-compartment device or kit as defined below, one of the compartments of which is devoted to the mixing of compositions (A") and (B) and may be shaken in a closed vessel entirely safely, until a homogeneous emulsion is obtained. Another subject of the invention is represented by a ready-to-use composition for dyeing or lightening human keratin fibres, which may be obtained by extemporaneous mixing, at the time of use, of a composition (A") with a composition (B); the resulting mixture comprising between 0.5% and 35% by weight of liquid organic compound with a Hansen solubility parameter value δΗ for the solvent of greater than 0 and less than 16 MPa^½, relative to the total weight of the mixture of compositions (Α') and (B); compositions (Α') and (B) being defined previously.

//- The multi-compartment devices: The invention also relates to a device containing two or more compartments, comprising:

• in a first compartment, a composition (A) as defined previously, said composition (A) comprising at least one oxidation dye, and optionally at least one basifying agent,

· in another compartment, a composition (B) comprising at least one oxidizing agent.

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

EXAMPLE 1 : OXIDATION DYEING

The compositions below were prepared (the amounts are expressed on a weight basis, i.e. as g% of starting material in unmodified form).

They are oxidation dye compositions, in particular:

a composition D_base according to the invention comprising water, at least one oil, at least one surfactant, an oxidation dye and at least 0.5% of an organic compound with a Hansen solubility parameter δΗ of less than 16 MPa^½; which is in the form of a microemulsion, - a composition D_0Xi_dizin_g agent according to the invention comprising water, at least one oil, at least one surfactant, an oxidizing agent and at least 0.5% of an organic compound with a Hansen solubility parameter δΗ of less than 16 MPa^½, which is in the form of a microemulsion, a comparative composition E_baSe outside the invention, comprising water, at least one oil, at least one surfactant, an oxidation dye and at least 0.5% of an organic compound with a Hansen solubility parameter δΗ of less than 16 MPa^½, but which is not in the form of a microemulsion;

a comparative composition E_oxidizing agent outside the invention, comprising water, at least one oil, at least one surfactant, an oxidizing agent and at least 0.5% of an organic compound with a Hansen solubility parameter δΗ of less than 16 MPa^½, but which is not in the form of a microemulsion.

Each of the compositions according to the invention D_0Xi_di_Zirig _agent (according to the invention) and D _aSe according to the invention is in the form of a microemulsion and is transparent.

Each of the comparative compositions E_OXidizin_g agent (comparative) and E_base (comparative) is not in the form of a microemulsion and is opaque.

Each final composition (i.e. ready-to-use) is composed of a mixture of 1 gram of an oxidizing composition + 1 gram of a base composition. An oxidation dye composition D according to the invention which is in the form of a microemulsion and which is translucent, and a comparative oxidation dye composition E which is not a microemulsion and which is opaque, are thus prepared.

The compositions prepared are the following: (the amounts are expressed in g% of starting material in unmodified form)

Cognis

a er qs

The microemulsions of compositions D_base and D_oxidi_Zing _agent of the invention formed virtually spontaneously, i.e. by simple homogenization using a magnetic bar, and are in the form of transparent, translucent, stable and homogeneous microemulsions, unlike the comparative compositions E_baSe and E_oxidizing agent which are not in microemulsion form. Specifically, they were also prepared by simple homogenization using a magnetic bar, but the compositions obtained are not transparent.

As indicated previously, the compositions are mixed at a rate of 1 gram of base composition per 1 gram of oxidizing composition, just before use, i.e. just before applying them to the keratin fibres.

The final ready-to-use composition D according to the invention (mixture of D_baSe + Doxidizing agent) remains translucent and in the form of a microemulsion.

In contrast, the comparative ready-to-use composition E (mixture of E_base ⁺ oxidizing agent) is not transparent. Dyeing process

Locks of natural Caucasian hair (NG) containing 90% white hairs were treated in the first case with the dye composition (D_base + D_0Xi_di_{Zing ag}ent) and in the second case with the dye composition (E_baSe + E_oxidizing agent) at a rate of 2.5 g of base for 2.5 g of oxidizing agent per gram of lock, and were each left to stand for 30 minutes at room temperature.

After this leave-on time, the locks were washed with Elvive Multivitamin shampoo, rinsed and then dried under a hood. The colouring obtained was measured using a Minolta CM-3600D spectrocolori meter.

The results obtained are as follows:

It was found that when the composition applied is in the form of a microemulsion (final composition D (Db_ase ⁺ D_oxidizing agent)), the colourings obtained are more intense than when the composition is not in microemulsion form (comparative composition E (E _ase + E_oxidiZing agent)), as attested by the colorimetric build-up values in dE^*ab (calculated as the difference between the dyed lock and the undyed lock) and which are significantly higher in favour of the colouring performed with composition D according to the invention.

Example 2: Lightening composition The following lightening compositions were prepared (the amounts are expressed on a weight basis, i.e. in g% of starting material in unmodified form).

The following compositions were prepared (the amounts are expressed on a weight basis, i.e. in g% of starting material in unmodified form).

They are oxidation dye compositions, in particular:

— a composition D_baSe according to the invention comprising water, at least one oil, at least one surfactant, an oxidation dye and at least 35% of an organic compound with a Hansen solubility parameter δΗ of less than 16 MPa^½; which is in the form of a microemulsion, — a composition D_0Xi_di_{Zing agent} according to the invention comprising water, at least one oil, at least one surfactant, an oxidizing agent and at least 35% of an organic compound with a Hansen solubility parameter δΗ of less than 16 MPa^½, which is in the form of a microemulsion,

— a comparative composition F _aSe outside the invention, which is in the form of a microemulsion comprising water, at least one oil, at least one surfactant and an oxidizing agent, but comprising more than 35% of an organic compound with a Hansen solubility parameter δΗ of less than 16 MPa^½,

— a comparative composition F_0Xidizing agent outside the invention, which is in the form of a microemulsion and comprising water, at least one oil, at least one surfactant and an oxidizing agent, but comprising more than 35% of an organic compound with a Hansen solubility parameter δΗ of less than 16 MPa^½.

Each of the compositions according to the invention D_0Xi_di_Zing _agenl (according to the invention) and D_base according to the invention is in the form of a microemulsion and is transparent.

Each of the comparative compositions F_0Xi_di_Zing _agent (according to the invention) and F_base is also in the form of a microemulsion and is transparent. However, compositions F_0Xj_dj_Zj_{ng agen}t and F_baSe each comprise more than 35% of liquid organic compound with a Hansen solubility parameter value δΗ of less than 16 MPa^½ and are thus outside the invention.

Each final composition (i.e. ready-to-use) is composed of a mixture of 1 gram of an oxidizing composition + 1 gram of a base composition.

A lightening composition D according to the invention, which is in microemulsion form, was thus prepared. It is moreover noted that the dye composition D is homogeneous and translucent, as is conventionally the case for a microemulsion. The lightening composition D according to the invention, and the compositions Doxidizing agent and D_base, each comprise less than 35% of liquid organic compound with a Hansen solubility parameter value δΗ of less than 16 MPa^½.

Similarly, a comparative lightening composition F, which corresponds to point F which is also in microemulsion form, was prepared. It is moreover noted that the comparative composition F is homogeneous and translucent. However, the comparative composition, and also the comparative compositions F_0Xidizing agent and base, each comprise more than 35% of liquid organic compound with a Hansen solubility parameter value δΗ of less than 16 MPa^½ and are therefore outside the invention. The compositions prepared are the following: (the amounts are expressed in g% of starting material in unmodified form)

Plantacare 818 UP

by Cognis)

Laureth-2 sold under 6.66 6.66 - - the name Dehydol

LS 2 DEO N by

Cognis

Sodium lauryl - - 20 20

sulfate

Monoethanolamine 4 4

50% aqueous - 12 - 12

hydrogen peroxide

solution

Water qs 100 qs 100 qs 100 qs 100

Lightening performance

Locks of natural pigmented chestnut-brown hair were treated independently with the ready-to-use lightening composition D (mixture of compositions D _ase + Denizing agent) and with the ready-to-use lightening composition F (mixture of compositions F _ase + F_0Xi_di_Zing _agent) at a rate of 2.5 g of Base for 2.5 g of Oxidizing agent per gram of locks and were left to stand for 40 minutes at 27°C.

After this leave-on time, the locks were washed with Elvive multivitamin shampoo, rinsed and then dried under a hood. The lightening obtained was measured using a Minolta CM-3600D spectrocolori meter.

The results obtained are as follows:

Description Colour L^*(D65) a^*(D65) b^*(D65) dE^*ab (D65) difference

Undyed reference Chestnut- 26.08 5.05 7.5 - brown

Colouring microemulsions of the invention Composition D (D_base + Coppery 35.9 9.24 17.84 14.86

Doxidizing agent) golden

Non-microemulsion comparative dye composition

Composition F (F_baSe + Coppery 33.52 9.29 16.8 12.64

Foxidizing agent) golden

We observed that the lightening composition D according to the invention makes it possible to achieve more extensive lightening when compared with the comparative lightening composition F outside the invention. This is also visible on the colorimetric measurements of dE^*ab (calculated as the difference between the pigmented lock and the lightened lock) which are significantly higher in favour of the lightening performed with the lightening composition according to the invention. Example 3:

The compositions Denizing agent (composition according to the invention) and Foxidizing _agent (comparative composition outside the invention) prepared in Example 2 were each mixed separately with each of the two commercial dyeing shades Preference P67 (L'Oreal Paris) and Inoa 6.66 (L'Oreal Professionnel).

The compositions were then applied to locks of natural Caucasian hair containing 90% white hairs, at a rate of 2.5 g of oxidizing agent for 2.5 g of dye composition per gram of hair, and were left to stand for 30 minutes at 27°C.

After this leave-on time, the locks were washed with Elvive multivitamin shampoo, rinsed and then dried under a hood. The colouring obtained is measured using a Minolta CM-3600D spectrocolori meter.

The following results were obtained:

Description Colour L^*(D65) a^*(D65) b^*(D65) dE^*ab (D65) build-up

Undyed reference, 90% - 64.21 0.45 15.88

white

Microemulsions of the invention Inoa 6.66 + D_0Xidizing agent Bright 28.64 18.76 10.24 40.4

red

Preference P67 + D₀xidizin_g Dark red 29.1 1 30.05 16.96 45.92 aqent

Comparative microemulsions (outside the invention)

Inoa 6.66 + F_oxidizing aqent Red 36.13 19.7 13.51 34.12

Preference P67 + F_0Xidi ing Red 32.87 30.19 19.12 43.32 aqent

It was found that the locks dyed using the oxidizing agent of the invention (Doxidizing agent) are intense and more coloured than those obtained using the microemulsion of the prior art (F_oxidizing agent), which is reflected on hair containing 90% white hairs by significantly larger DE build-up values.

Example 4: Lightening composition

The following ready-to-use composition G according to the invention was prepared: (the amounts are expressed in g% of starting material in unmodified form)

re erence an acare y ogn s Laureth-2 sold under the name Dehydol LS 2 DEO N by 6.3

Cognis

Monoethanolamine 4

50% hydrogen peroxide solution 20

Water 100

The microemulsion G obtained forms virtually spontaneously by simple stirring with a magnetic bar and is transparent.

Locks of natural pigmented Caucasian hair with a tone depth of 5 and Chinese hair with a tone depth of 4 were treated with composition G and were left in place for 30 minutes at 27°C.

After this leave-on time, the locks were washed with Elvive Multivitamin shampoo, rinsed and then dried under a hood. The lightening was measured using a Minolta CM-3600D spectrocolorimeter in comparison with untreated control locks.

The results obtained are as follows:

letters "TD" mean tone depth. As shown by the colorimetric measurements, locks with a very good level of lightening were obtained.

Example 5: Direct dye compositions comprising a synthetic direct dye

Two direct dye compositions comprising a synthetic direct dye were prepared. In particular, a composition D according to the invention, which is in the form of a microemulsion, and a comparative composition A outside the invention, which is not in the form of a microemulsion, were prepared.

Composition D is indeed in the form of a microemulsion; it is moreover noted that the dye composition D is indeed homogeneous and transparent. On the other hand, the comparative composition A outside the invention is not in the form of a microemulsion; specifically, although homogeneous, it is opaque. The following compositions were prepared (the amounts are expressed in g% of starting material in unmodified form):

The colouring microemulsion D forms virtually spontaneously, by simple homogenization with a magnetic bar, and is in the form of a transparent, stable, homogeneous microemulsion in comparison with comparative composition A, which is not in the form of a microemulsion.

Dyeing process

Locks of permanent-waved grey (PWG) Caucasian hair containing 90% white hairs were treated with the dye compositions A or D and were left in place for 30 minutes at 27°C.

After this leave-on time, the locks were washed with Elvive Multivitamin shampoo, rinsed and then dried under a hood.

The colourings obtained were measured using a Minolta CM-3600D spectrocolorimeter. The results obtained are as follows:

It was found that very good levels of colouring were obtained with composition D according to the invention which is in the form of a microemulsion, in particular better than those obtained with the comparative composition which is not in the form of a microemulsion (composition A); as attested by the dE^*ab build-up values.

Claims

1. Composition (A) for dyeing or lightening keratin fibres, in the form of a microemulsion comprising:

i) at least water;

ii) at least one non-carbonyl-based oil;

iii) at least one liquid organic compound with a Hansen solubility parameter value δΗ of greater than 0 and less than 16 MPa^½, the total content of liquid organic compound(s) with a Hansen solubility parameter value δΗ of less than 16 MPa^½ ranging from 0.5% to 35% by weight relative to the weight of the composition;

iv) at least one surfactant; and

v) at least one compound chosen from:

b. chemical oxidizing agents;

c. basifying agents;

d. and mixtures thereof.

2. Composition according to the preceding claim, comprising at least one oxidizing agent preferably 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 peracids and precursors thereof; preferentially hydrogen peroxide.

3. Composition according to Claim 1 or according to Claim 2, comprising at least one colouring agent chosen from oxidation dyes, preferably chosen from oxidation bases such as para-phenylenediamines, bis(phenyl)alkylenediamines, para- aminophenols, ortho-aminophenols and heterocyclic bases, and the addition salts thereof, and couplers, chosen from meta-phenylenediamines, meta-aminophenols, meta-diphenols, naphthalene-based couplers and heterocyclic couplers, and also the addition salts thereof; and mixtures thereof.

4. Composition according to any one of the preceding claims, comprising at least one basifying agent, preferably chosen from ammonia, alkali metal carbonates or bicarbonates such as sodium carbonate or bicarbonate and potassium carbonate or bicarbonate, sodium hydroxide, potassium hydroxide, and alkanolamines, or mixtures thereof; preferably, the basifying agent is chosen from ammonia and organic amines, particularly alkanolamines such as monoethanolamine, and mixtures thereof.

5. Composition according to any one of the preceding claims, comprising at least one colouring agent chosen from direct dyes, preferably chosen from:

- synthetic direct dyes preferably chosen from nitrobenzene dyes; azo, methine, azomethine, hydrazono or styryl direct dyes; azacarbocyanines such as tetraazacarbocyanines (tetraazapentamethines); quinone direct dyes, and in particular anthraquinone, naphthoquinone or benzoquinone direct dyes; azine direct dyes; xanthene direct dyes; triarylmethane direct dyes; indoamine direct dyes, indigoid direct dyes, phthalocyanine direct dyes and porphyrin direct dyes, alone or as mixtures;

- natural dyes preferably chosen from lawsone, henna, curcumin, chlorophyllin, alizarin, kermesic acid, purpurin, purpurogallin, indigo, Tyrian purple, sorghum, carminic acid, catechin, epicatechin, juglone, bixin, betanin, quercetin, chromene dyes and chroman dyes, including haematein and brazilein, and laccaic acids, alone or as mixtures;

- and mixtures thereof.

6. Composition according to any one of the preceding claims, in which the non- carbonyl-based oil is chosen from:

- oils with a polarity £ of less than 2.5; with £ corresponding to the dielectric constant at 25°C of the oil, preferably chosen from:

o linear or branched hydrocarbons, of mineral or synthetic origin, which are optionally halogenated, comprising between 6 and 16 carbon atoms, preferably chosen from hexane, cyclohexane, undecane, dodecane, isododecane, tridecane, perfluorohexane and isohexadecane, and mixtures thereof;

o and mixtures thereof;

saturated or unsaturated, linear or branched liquid fatty alcohols, preferably comprising 6 to 30 carbon atoms, preferably of formula C_nH_2n+iOI-l with n being an integer between 6 and 30 inclusive; preferably chosen from oleyl alcohol, linolenyl alcohol, linoleyl alcohol, ricinoleyl alcohol, undecylenyl alcohol, isostearyl alcohol and octyldodecanol; and mixtures thereof;

linear or branched, saturated or unsaturated liquid ethers preferably comprising from 12 to 60 carbon atoms in total, preferably of formula [C_nH_2n+i]₂0 with n being an integer between 6 and 30 inclusive, for instance distearyl ether;

and mixtures thereof.

7. Composition according to any one of the preceding claims, in which the non- carbonyl-based oil is an oil with a polarity £ of less than 2.5, preferably a hydrocarbon-based oil, better still a liquid hydrocarbon.

8. Composition according to any one of the preceding claims, in which the non- carbonyl-based oil is an oil with a polarity £ of less than 2.5, chosen from:

Cs-Cis alkanes and isoalkanes, preferably such as isododecane;

liquid paraffin or derivatives thereof,

squalane,

isoeicosane,

- liquid petroleum jelly,

naphthalene oil,

polybutylenes,

hydrogenated polyisobutylenes,

decene/butene copolymers and polybutene/polyisobutene copolymers, and

polydecenes and hydrogenated polydecenes,

and mixtures thereof,

preferably chosen from isododecane and liquid petroleum jelly, and mixtures thereof.

9. Composition according to any one of the preceding claims, in which the composition (A) comprises a total value of non-carbonyl-based oil(s) of between 5% and 70% by weight relative to the weight of composition (A), preferably between 10% and 40% by weight and better still between 15% and 35% by weight relative to the total weight of the composition.

10. Composition according to any one of the preceding claims, in which said liquid organic compound(s) with a Hansen solubility parameter value δΗ of greater than 0 and less than 16 MPa¹'² are chosen from:

• alcohol ethers, in particular C₁-C4 ethers of C5-C30 alcohols, which are preferably saturated, linear or branched, optionally interrupted with one or more non-adjacent ether functions;

• aliphatic esters of C₁-C4 carboxylic acids and of C3-C₁₀ monoalcohols or polyhydroxylated, interrupted with one or more non-adjacent ether functions;

• aromatic ethers, in particular of C₆-Ci₀, of a Ci-C₆ alkyl optionally bearing a hydroxyl group, • (C₆-Cio)aryl(Ci-C₆) alkyl ethers, of a Ci-C₆ alkyl optionally bearing a hydroxyl group,

• alkanols bearing an aryl substituent, preferably for which the aryl part is C₆- Cio, advantageously C₆, and the alkyl part of the alkanol is C C₄, this alkyl part possibly ending or being interrupted with a heteroatom, advantageously oxygen or a hydroxyl group, preferably such as benzyl alcohol;

• lactones preferably of formula (iii), and also mixtures thereof, with:

in which R' represents a hydrogen, a linear or branched C-i-Cs alkyl, a linear or branched CrC₄ hydroxyalkyl, n being equal to 1 , 2 or 3, and preferably R' represents a hydrogen, a linear or branched C1-C6 alkyl or a linear or branched C1-C2 hydroxyalkyl;

• and mixtures thereof.

11. Composition according to the preceding claim, in which said liquid organic compound(s) with a Hansen solubility parameter value δΗ of greater than 0 and less than 16 MPa¹ⁱ² are chosen from alcohol ethers, aliphatic esters, aromatic ethers and alkanols bearing aryl substituents, and mixtures thereof, preferably chosen from alkanols bearing aryl substituents, such as benzyl alcohol.

12. Composition according to the preceding claim, in which said liquid organic compound(s) with a Hansen solubility parameter value δΗ of greater than 0 and less than 16 MPa^1/2 are chosen from dipropylene glycol monomethyl ether acetate, dipropylene glycol methyl ether, dipropylene glycol mono-n-butyl ether, tripropylene glycol methyl ether, propylene glycol n-butyl ether, propylene glycol n-propyl ether, propylene glycol monomethyl ether, diethylene glycol monomethyl ether and monoethyl ether, 3-phenyl-1 -propanol, 2-phenyl-1 -propanol, benzyl alcohol, benzyloxyethanol and phenoxyethanol, and mixtures of these compounds.

13. Composition according to any one of the preceding claims, in which the liquid organic compound(s) with a Hansen solubility parameter value δΗ of greater than 0 and less than 16 MPa^1/2 generally represent from 0.5% to 35% by weight, preferably from 1% to 35% by weight, more particularly from 3% to 30% by weight and better still 5% to 25% by weight relative to the total weight of the composition.

14. Composition according to any one of the preceding claims, in which the surfactant(s) are chosen from nonionic surfactants, preferably chosen from:

- oxyalkylenated (C₈-C24)alkylphenols; - saturated or unsaturated, linear or branched, oxyalkylenated or glycerolated C₈-C₄₀ alcohols, comprising one or two fatty chains;

- saturated or unsaturated, linear or branched, oxyalkylenated C₈-C₃o fatty acid amides;

- fatty acid esters of sucrose;

- (C₅-C₃o)alkyl(poly)glycosides, (C₈-C₃₀)alkenyl(poly)glycosides, which are optionally oxyalkylenated (0 to 10 oxyalkylene units) and comprising from 1 to 15 glucose units, (C₈-C₃₀)alkyl(poly)glucoside esters;

- saturated or unsaturated, oxyethylenated plant oils;

- aldobionamides;

- amine oxides;

- oxyethylenated and/or oxypropylenated silicones;

- and mixtures thereof;

preferably, said nonionic surfactant(s) are chosen from:

- saturated or unsaturated, linear or branched C₈-C4o, alcohols, comprising from 1 to 10 oxyethylene (OE) and (C₆-C₃₀) alkyl(poly)glucosides, and mixtures thereof.

15. Composition according to any one of the total preceding claims, in which the surfactant(s) are chosen from: anionic surfactants, better still chosen from:

- alkyl sulfates, alkyl ether sulfates, alkylamido ether sulfates, alkylaryl polyether sulfates, monoglyceride sulfates, alkyl sulfonates, alkylamide sulfonates, alkylaryl sulfonates, alpha-olefin sulfonates, paraffin sulfonates, alkyl sulfosuccinates, alkyl ether sulfosuccinates, alkylamide sulfosuccinates, alkyl sulfoacetates, acyl sarcosinates, acyl glutamates, alkyl sulfosuccinamates, acyl isothionates and N-acyl taurates; salts of alkyl monoesters of polyglycoside-polycarboxylic acids, acyl lactylates, salts of D-galactosiduronic acids, salts of alkyl ether carboxylic acids, salts of alkylaryl ether carboxylic acids, salts of alkylamido ether carboxylic acids; and the corresponding non-salified 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 and mixtures thereof;

preferably, the anionic surfactant(s) are chosen from alkyl sulfates and alkyl ether sulfates, and mixtures thereof.

16. Composition according to any one of the preceding claims, in which the total content of surfactant(s) ranges from 0.1 % to 50% by weight, preferably from 1 % to 30% by weight and even better still from 5% to 20% by weight relative to the total weight of the composition.

17. Composition according to any one of the preceding claims, comprising:

- a total content of surfactant(s) of between 1 % and 30% by weight, relative to the total weight of the composition;

a total content of liquid organic compound(s) with a Hansen solubility parameter value δΗ of greater than 0 and less than 16 MPa^½ of between 3% and 30% by weight, relative to the weight of the composition.

18. Process for dyeing or lightening keratin fibres, which consists in applying to the keratin fibres at least one composition (A) according to any one of the preceding claims.

19. Process for dyeing keratin fibres, comprising the application of a composition A as defined previously, comprising at least one colouring agent, optionally in the presence of an oxidizing agent.

20. Device comprising at least two compartments, containing:

• in a first compartment, a composition corresponding to composition (A) as defined in any one of Claims 1 to 17; and

• in another compartment, a composition corresponding to composition (B), which comprises at least one oxidizing agent, preferably hydrogen peroxide.