FR3015894A1 - LIGHTENING COLORING PROCESS USING A SUBSTRATE CARRYING AT LEAST ONE OXIDIZING AGENT AND AN AQUEOUS COMPOSITION COMPRISING ONE OR MORE DIRECT COLORS - Google Patents

Abstract

The present invention relates to the field of dyeing keratinous fibers, and more particularly to the field of hair dyeing. The present invention relates to a lightening dyeing process for keratinous fibers, in particular human keratinous fibers such as the hair, consisting in using on said fibers i) a substrate comprising at its surface one or more oxidizing agents preferably under solid form, and ii) an aqueous composition comprising one or more direct dyes.

Description

The present invention relates to the field of dyeing of keratinous fibers, and more particularly to the field of hair dyeing. The present invention relates to a lightening dyeing process for keratinous fibers, in particular human keratinous fibers such as the hair, consisting in using on said fibers i) a substrate comprising at its surface one or more chemical oxidizing agents, and ii) an aqueous composition comprising one or more direct dyes. Since a long time, many people seek to change the color of their hair and in particular to hide their white hair. To do this, there are essentially two types of staining that have been developed. The first type of staining is the so-called permanent staining or oxidation which uses dye compositions containing oxidation dye precursors, generally called oxidation bases. These oxidation bases are colorless or weakly colored compounds which, when combined with oxidizing products, can give rise to colored compounds by a process of oxidative condensation.

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

The second type of staining is so-called semipermanent staining, or direct staining, which consists of applying to the keratin fibers direct dyes which are colored and coloring molecules, having an affinity for the fibers, to be allowed to pausate to allow the molecules to penetrate, through diffusion inside the fiber, then rinse them. In order to perform these stains, the direct dyes generally employed are chosen from nitrobenzene, anthraquinone, nitropyridine, azo, xanthene, acridine, azine or triarylmethane direct dyes. This type of process does not require the use of an oxidizing agent to develop the coloring. However, it is not excluded to implement in order to obtain a lightening effect with the coloring. We then speak of a direct or semi-permanent coloration in lightening conditions. The permanent or semipermanent coloring processes in lightening conditions therefore consist in using, with the dyeing composition, an aqueous composition comprising at least one oxidizing agent, under alkaline pH conditions in the vast majority of cases. This oxidizing agent has the role, at least in part, of degrading the melanin of the hair, which, depending on the nature of the oxidizing agent present, leads to a more or less pronounced lightening of the fibers. Thus, for relatively low lightening, the oxidizing agent is generally hydrogen peroxide.

When greater lightening is desired, it is customary to use peroxygenated salts, such as persulfates for example, in the presence of hydrogen peroxide. However, it has been found that it is often difficult or impossible to obtain lightening dyes having original visual results by implementing the lightening dyeing methods described above. In particular, these methods often have the defect of not satisfactorily obtaining colored patterns, which can lead to original optical effects on the whole of the hair, which are both sharp and precise.

In addition, these methods often have the disadvantage of staining the hands of the user or the hairdresser when applying hair dye compositions and oxidizing compositions. In the same way, these methods can also cause unwanted spots on the scalp, facial contour and / or clothing of the user that may be due to application errors and / or run-off problems. compositions used. These methods also include the risk of not leading to the final lightening coloration desired by the user because of an error that may occur during the handling of the oxidizing or dyeing compositions or resulting in the wrong choice of the dyeing compositions of the present invention. departure. It has also been found that the storage of the oxidizing compositions and dyeing compositions can pose congestion and / or storage problems over time, particularly in hairdressing salons. Furthermore, it has been found that the permanent coloring processes in lightening conditions can be limited, in particular because of the range of colors attainable. In particular, it is often difficult to achieve very chromatic colorations. The semi-permanent coloring processes in lightening conditions pose a problem of compatibility between the direct dyes and the oxidizing agents, especially in the case of peroxygenated salts. Indeed, during mixing between the direct dyes and the oxidizing agent, the latter can alter them by losing their coloring activity which decreases the efficiency of the process. Since such alteration proceeds progressively, the coloring result can vary significantly from the first lock to the last lock. It can thus be seen that areas of the hair treated first can be stained satisfactorily while the areas of the hair treated last can be more discolored than stained because of the alteration of the direct dyes by the oxidizing agent. It is already known from FR2984087 to carry out a staining or bleaching process comprising contacting the keratinous fibers with a substrate carrying a coloring or bleaching composition having a formulation that varies according to the position on said substrate in order to get a color or faded color. However, this document does not describe a process capable of producing precise patterns and / or of producing solid colorations. There is therefore a real need to implement a lightening dyeing process for keratinous fibers, in particular human keratinous fibers such as the hair, which does not have the drawbacks mentioned above, that is to say which is in particular capable of to conduct on said fibers to lightening colors that can be united and / or present original visual results, in particular precise patterns, to reduce the problems of size and / or conservation of the compositions used, to minimize the risks of contact that can occur between the compositions used and the hands, the scalp and / or the clothing of the user and the risk of not obtaining the desired color. This object is achieved by the present invention which has for object a method of lightening dyeing keratinous fibers, in particular human keratinous fibers such as the hair consisting in using on said fibers i) a substrate comprising at its surface one or more chemical oxidizing agents, preferably in solid form, and ii) an aqueous composition comprising one or more direct dyes. The lightening dyeing process of keratinous fibers thus uses a substrate on which one or more chemical oxidizing agents have been deposited, preferably in solid form. In other words, the substrate has been pretreated at its surface by an oxidizing composition containing one or more chemical oxidizing agents. Thus, during the contacting of the keratinous fibers with the pretreated substrate and the aqueous composition, the oxidizing agents present on the surface of the substrate and the dyes resulting from the aqueous composition dissolve, in contact with said fibers, to lead to lightening colorings that can be united and / or colored patterns. In particular, the oxidizing agent or agents are deposited on the surface of the substrate and may be located at certain locations on said surface so as to represent one or more geometrical shapes in order to then produce one or more colored patterns on the keratin fibers after contact between said fibers, the pretreated substrate and the aqueous dye composition. In other words, the substrate may be pretreated in places with an oxidizing composition containing one or more oxidizing agents so that one or more colored patterns can then be produced on the fibers. The dyeing process according to the invention thus makes it possible to produce, with great precision, colored patterns, which are visually clear, on the keratinous fibers. In particular, this method makes it possible to produce millimeter-sized colored patterns having all types of shapes, such as dots or waves, which are easily reproducible. These patterns can thus lead to original optical effects when they are then repeated throughout the hair. In other words, the method according to the invention makes it possible to obtain patterns, in particular of millimeter size, in a homogeneous manner over the whole of the hair, or in a localized manner on a part of the hair. These patterns may be whimsical from an aesthetic point of view or serve to mask an irregularity in the color or appearance of keratin fibers, especially in the case of regrowth or sharpening tips. The method according to the invention advantageously makes it possible to lead to thinned keratinous fibers having clear and precise colored patterns, in particular in the implementation of an aqueous composition containing one or more direct dyes. The method according to the invention makes it possible in particular to obtain keratinous fibers that are thinned from root to tip with colored patterns that can be located at several points on the fiber. Indeed, the dyeing process makes it possible to lighten and more visibly color the keratinous fibers where the substrate comprises at its surface the oxidizing agent (s) and to color them without lightening effect at the site. wherein the substrate does not have at its surface said oxidizing agents. For example, when the substrate comprises at its surface two strips spaced from one another containing one or more chemical oxidizing agents and the aqueous composition comprises one or more direct dyes, the two bands give the keratin fibers an effect. lightening and pronounced coloration, and the other areas are colored without lightening effect by the direct dyes. This results in a relief effect at the level of color significantly contrasted. The method thus makes it possible to obtain lightening effects and coloring effects that can be alternated along the keratin fiber. The alternation between the lightening effects and the coloring effects is advantageously obtained in the case where the aqueous composition contains a direct dye sensitive to the presence of an oxidizing agent. Indeed, in this case, the activity of the direct dye will be altered by the oxidizing agent at the place where it is deposited on the substrate. Moreover, thanks to the use of substrates comprising one or more oxidizing agents, that is to say substrates previously treated with a composition containing such oxidizing agents, this process makes it possible to reduce the risk of stains on the hands, the scalp, face and / or clothing of the user. This method also makes it possible to avoid run-off problems and / or application errors of the compositions.

In the same way, thanks to the application of such previously treated substrates, this process makes it possible to reduce the storage problem of the oxidizing compositions and dyeing compositions usually used in conventional coloring processes, which makes it possible to reduce significantly congestion problems. In particular, the user may have at his disposal a larger number of substrates previously treated with oxidizing agents while having a saving of space in hairdressing salons.

Furthermore, the process according to the invention has the advantage of using previously treated substrates which are stored satisfactorily over a period of time which can range, for example, from a few days to several months. The method according to the invention also has the advantage of minimizing the risk of errors that may occur during the handling of the compositions or in the choice of starting compositions in order to obtain the desired coloration. The method according to the invention also has the advantage of minimizing the risk of alteration of the direct dyes relative to the oxidizing agent since they are not formulated within the same composition. Other objects and features, aspects and advantages of the invention will emerge even more clearly on reading the description and examples which follow.

As indicated above, the lightening dyeing method uses on said fibers a substrate which has been previously treated at its surface with a composition containing one or more chemical oxidizing agents. The substrate may be in the form of a sheet element or another embodiment. According to a preferred embodiment, the substrate is a sheet element. The sheet element may be made of plastic, in particular thermoplastic, paper, metal, especially aluminum, woven, non-woven non-absorbent fibers, especially cellulose or one of its derivatives, or polyamide 6 6. Preferably, the sheet element is a sheet of plastic material, especially thermoplastic, or nonwoven material of non-absorbent fibers, in particular a nonwoven based on cellulose or a derivative thereof. In particular, the sheet element used in the coloring process is a plastic sheet. The sheet element may consist of a water-soluble material, which allows, for example, to be removed by washing the hair. The sheet member preferably comprises an assembly of a layer of a water-soluble material and a layer of a water-insoluble material, for example an aluminum foil.

The substrate can be arranged to be closed around a lock of hair. In this case, such a substrate is for example provided with a fixing means for maintaining it in such a state, for example an adhesive disposed near an edge or a mechanical attachment relief.

Preferably, the sheet element has a basis weight ranging from 20 to 300 g / m 2, more preferably from 30 to 200 g / m 2. The sheet element has in particular a thickness ranging from 40 to 1000 micrometers, preferably a thickness ranging from 40 to 400 micrometers, better still from 60 to 200 micrometers. The sheet element can be opaque or transparent. Preferably, the sheet element is transparent which facilitates its positioning on the hair, especially when one wants to make one or more patterns at a specific location of the lock or hair. In other words, the transparency of the sheet element facilitates the implementation of the lightening process, especially in the production of discolored patterns, and improves its accuracy.

The sheet element used in the coloring process according to the invention is preferably flexible and resistant. Preferably, the resistance of the sheet is greater than 300 kPa (TAPPIT403 standard).

Preferably, the sheet member is water resistant. In particular, the water absorption of said element is measured by the COBB test 60 which corresponds to the ability of said element to absorb water during a contact of 60 seconds (whose procedure is given by the ISO 535 standard, measure TAPPI-T411).

Thus the sheet element absorbs less than 100 g / m2, and preferably less than 40 g / m2 of water. Preferably, the sheet member is resistant to oily compounds. Thus, it is possible to use a so-called "food" paper, that is to say a complex of paper and polyethylene-type polymeric compound or paper and paraffin, capable of being a barrier to water and oils. The sheet element may optionally be covered with a deposit of an adhesive composition. This adhesive layer makes it possible to improve the adhesion of the chemical oxidizing agent (s) at the surface of the sheet element. According to a preferred embodiment, the sheet element, after treatment with the composition containing one or more oxidizing agents, may be covered by a protective means whose function is to protect the surface of said element of the outer elements.

Thus the sheet element comprises one or more oxidizing agents that can be coated with a protective layer. Such a protective layer makes it possible to minimize the deterioration of the oxidizing agent or agents related to humidity, light or oxygen in the air. Thus, the sheet element can be protected by implementing processes used in paper varnishing techniques (fatty varnish, acrylic, etc.), and in particular by using an aqueous or organic acrylic varnish composition.

In this way, the sheet element containing one or more oxidizing agents can be surface-protected with a layer of acrylic lacquer. According to this embodiment, the sheet element contains one or more oxidizing agents and is covered by a layer of acrylic lacquer. In other words, the sheet element contains a layer containing one or more oxidizing agents and a layer of acrylic varnish, the two layers being juxtaposed one on the other.

The weight per unit area of the acrylic lacquer layer varies from 1 to 10 g / m 2, and more particularly from 2 to 5 g / m 2. According to one variant, the sheet element is covered with a protective and detachable sheet. To do this, the edges of the sheet element and the protective sheet are glued together by means of a fixing means, in particular an adhesive, which can be produced by any type of method, in particular by heat sealing. Thus a good cohesion is ensured between the protective sheet and the sheet element. Advantageously, the protective sheet is opaque to UV for better protection. According to another variant, the sheet element may be covered by another means of protection, namely a hermetic package, defining above the element a space without oxygen (under vacuum or inert atmosphere).

As indicated above, the substrate comprises at its surface one or more chemical oxidizing agents. The oxidizing agent (s) may be present on all or part of the surface of the substrate. Thus the surface of the substrate may be completely or partially covered by a layer containing one or more oxidizing agents. This layer represents a surface treatment layer of the substrate. By chemical oxidizing agent is meant an oxidizing agent different from the oxygen of the air.

The chemical oxidizing agent (s) may be chosen from hydrogen peroxide, urea peroxide, alkali metal bromates or ferricyanides, peroxygenated salts such as, for example, persulfates, perborates and alkali metal or alkaline metal percarbonates. earthy, as well as peracids and their precursors. Preferably, the chemical oxidizing agent or agents are chosen from solid chemical oxidizing agents, and more preferably from urea peroxide, alkali metal bromates or ferricyanides, peroxygenated salts such as, for example, persulfates, perborates and percarbonates. of alkali or alkaline earth metals. More preferably, the oxidizing agent (s) is (are) chosen from hydrogen peroxide, peroxygenated salts, for example persulfates, and mixtures thereof. The chemical oxidizing agent (s) may be present advantageously in a content ranging from 0.01 to 100% by weight, preferably in a content ranging from 10 to 90% by weight, better still from 20 to 80% by weight relative to the weight. of the substrate treatment layer. The oxidizing agent (s) may be present on all or preferably on a part of the surface of the substrate. Thus, the surface of the substrate may be completely or partially covered by a layer containing one or more chemical oxidizing agents.

Preferably, the chemical oxidizing agent (s) are deposited on a part of the surface of the substrate and represent patterns which, after contact with the keratinous fibers and the aqueous composition containing the direct dye (s), will make it possible to produce the colored patterns on said fibers. In other words, the oxidizing agent (s) are deposited in the form of patterns on the surface of the substrate. Thus, the surface of the substrate comprises one or more oxidizing agents arranged in one or more particular geometrical shapes, called patterns, which, after contact with the aqueous composition containing the direct dye (s), lead to obtaining colored patterns on said fibers.

The pattern or patterns have a shape that can be arbitrary and in particular geometric. Thus, the oxidizing agent (s) are present on a portion of the surface of the substrate and represent patterns having the desired shape. The substrate may comprise on the face opposite the face carrying the oxidizing agent or agents a copy of the pattern or patterns having the desired shape. The realization of these patterns on the opposite face makes it possible to indicate the place where the oxidizing agent (s) can then be deposited on the surface of the substrate. Such an embodiment subsequently makes it easier to place the substrate on the keratinous fibers where the pattern is to be made. Alternatively, such patterns are made on the surface of the substrate prior to pretreatment so as to subsequently deposit the oxidizing agent (s) directly onto the patterns. In other words, the patterns that one wishes to obtain on the keratinous fibers can be made in advance on the surface of the substrate to be pretreated. In both cases, the production of patterns on the surface of the substrate to be pretreated or on the surface opposite the pretreated surface is all the more advantageous when the substrate used is transparent. In particular, the patterns can be printed in advance on the substrate. The substrate may further comprise at its surface one or more alkaline agents. In other words, the substrate may be pretreated with an oxidizing composition comprising one or more chemical oxidizing agents and one or more alkaline agents. The alkaline agents may be chosen from carbonates, alkanolamines such as mono-, di- and triethanolamines and their derivatives, oxyethylenated and / or oxypropylenated ethylenediamines, mineral or organic hydroxides, and alkali metal silicates such as metasilicates. sodium, amino acids of basic preferences such as arginine, lysine, ornithine, citruline and hystidine, and the compounds of formula (I) below: a \ Rb N - W - NRRC d (j) in which: - W is a divalent (C 1 -C 8) alkylene group, preferably propylene, optionally substituted in particular with a hydroxyl group or a C 1 -C 4 alkyl radical; Ra, Rb, R, and Rd, which are identical or different, represent a hydrogen atom, a Ci-C4 alkyl radical or a hydroxyalkyl radical. The inorganic or organic hydroxides, particularly the mineral or organic hydroxides, are preferably chosen from: the hydroxides of an alkali metal, ii) the hydroxides of an alkaline earth metal, such as sodium or potassium hydroxides, iii) the hydroxides of a transition metal, such as the hydroxides of Group III metals, IV, V and VI, iv) hydroxides of lanthanides or actinides, quaternary ammonium hydroxides and guanidinium hydroxide.

The hydroxide may be formed in situ such as, for example, guanidine hydroxide by reaction of calcium hydroxide and guanidine carbonate. In particular, the alkaline agents used are solid in the dry state.

In a first variant of the invention, the alkaline agents are solid before use in the oxidizing composition, and are preferably chosen from carbonates, mineral hydroxides such as hydroxides or soluble silicates of sodium or potassium.

In another variant of the invention, the alkaline agents are chosen from alkanolamines, in particular mono-, di- and triethanolamines.

The agent (s) alkali (s) may be present in a content ranging from 0.01 to 20% by weight, relative to the total weight of the treatment layer of the surface of the substrate. The alkaline agent (s) may be present in a content ranging from 0.01 to 20% by weight, relative to the total weight of the oxidizing treatment composition of the surface of the substrate. The oxidizing composition may be aqueous or anhydrous. When the oxidizing composition is aqueous and contains one or more alkaline agents, the pH is preferably from 7.5 to 13, better still from 8 to 12, and still more preferably from 8 to 11. The substrate may also comprise one or more compounds such as acids, and in particular citric acid. The active agent (s) may be present in a content ranging from 1 to 20% by weight relative to the weight of the chemical oxidizing agents both with respect to the treatment composition and with respect to the surface layer after pretreatment. The oxidizing composition may contain one or more organic solvents. As organic solvent, mention may be made of monoalcohols or diols, linear or branched, preferably saturated, comprising 2 to 6 carbon atoms, such as ethyl alcohol, isopropyl alcohol, hexylene glycol (2- methyl 2,4-pentanediol), neopentyl glycol and 3-methyl-1,5-pentanediol, butylene glycol, dipropylene glycol and propylene glycol; aromatic alcohols such as benzyl alcohol, phenylethyl alcohol; polyols with more than two hydroxyl functions such as glycerol; polyol ethers such as, for example, monomethyl, monoethyl and monobutyl ethers of ethylene glycol or propylene glycol; and the alkyl ethers of diethylene glycol, especially C1-C4, such as, for example, monoethyl ether or diethylene glycol monobutyl ether. The element may also include at the surface of the substrate a deposit of one or more activators or catalysts. In particular, the substrate comprises a deposit of one or more metal salts in a content ranging from 1 to 20% by weight relative to the weight of the chemical oxidizing agents. The substrate used in the process according to the invention is pretreated with an oxidizing composition containing one or more oxidizing agents. Preferably, the substrate is pretreated with an oxidizing composition containing one or more oxidizing agents and one or more alkaline agents. The oxidizing composition may be liquid or in powder form, preferably in powder form. The oxidizing composition deposited on the surface of the substrate may possibly result from successive treatments of the substrate with one or more oxidizing agents on the one hand, one or more alkaline agents on the other hand, and optionally one or more active agents as described above. As indicated above, the dyeing process uses an aqueous composition comprising one or more direct dyes which interacts with the substrate comprising at its surface one or more oxidizing agents.

By "direct dye" is meant natural and / or synthetic dyes, different from oxidation dyes. These are dyes that will diffuse superficially on the fiber. Direct dyes can be anionic, nonionic or cationic. They are preferably cationic or nonionic, either as a mixture or as sole dyes. As direct dye according to the invention include acridine dyes; acridones; anthranthrones; anthrapyrimidines; anthraquinones; azines; (poly) azo, hydrazono or hydrazones, especially arylhydrazones; azomethines; benzanthrones; benzimidazoles; benzimidazolones; benzindoles; benzoxazoles; benzopyrans; benzothiazoles; benzoquinones; bisazines; bis isoindolines; carboxanilides; coumarins; cyanines such as azacarbocyanines, diazacarbocyanines, diazahemicyanines, hemicyanines, or tetraazacarbocyanines; diazines; diketopyrrolopyrroles; dioxazines; diphenylamines; diphenylmethanes; dithiazines; flavonoids such as flavanthrones and flavones; fluorines; formazans; indamines; indanthrones; indigoides and pseudoindigoids; indophenols; indoanilines; isoindolines; isoindolinones; isoviolanthrones; lactones; (poly) methines such as dimethines of stilbene or styryl types; naphthalimides; naphthanilides; naphtholactams; naphthoquinones; nitro, especially nitro (hetero) aromatic; oxadiazoles; oxazines; perilones; perinones; perylenes; phenazines; phenoxazine; phenothiazines; phthalocyanine; polyenes / carotenoids; porphyrins; pyranthrones; pyrazolanthrones; pyrazolones; pyrimidinoanthrones; pyronines; quinacridones; quinolines; quinophthalones; squaranes; tetrazoliums; thiazines, thioindigo; thiopyronines; triarylmethanes, or xanthenes. More particularly, the direct dyes of the invention are chosen from neutral, acidic or cationic nitro-benzene direct dyes, neutral azo, acidic or cationic direct dyes, tetraazapentamethine dyes, quinone dyes, and in particular neutral, acidic or cationic anthraquinone dyes. azine direct dyes, triarylmethane direct dyes, azomethine direct dyes and natural direct dyes. According to one embodiment, the direct dyes of the invention are anionic. The latter are dyes commonly known as "acid dyes" or "acid dyes" for their affinity for alkaline substances (see for example "Industrial Dyes, Chemistry, Properties, Application", Klaus Hunger Ed. WileyVCH Verlag GmbH & CoKGaA, Weinheim 2003 ). Acidic or anionic dyes are known in the literature (see for example "Ullman's Encyclopedia of Industrial Chemistry", Azo Dyes, 2005 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim 10.1002 / 14356007.a03 245, item 3.2, ibid, Textile Auxiliaries, 2002 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim 10.1002 / 14356007.a26 227 and "Ashford's Dictionary of Industrial Chemicals, Second Edition, 14-p.39, 2001). By direct anionic dyes is meant any direct dye comprising in its structure at least one sulphonate group SO 3 - and / or at least one carboxylate group C (O) O- and optionally one or more anionic groups G- with G-, which may be identical or different. , representing an anionic group selected from 0-alkoxide, thiolate S-, carboxylate and thiocarboxylate: C (Q) Q'- with Q, Q 'identical or different representing an oxygen or sulfur atom; preferably G- represents a carboxylate i.e. Q and Q 'represents an oxygen atom. Preferred anionic dyes are selected from acidic nitro dyes, acidic azo dyes, acidic azine dyes, acidic triarylmethane dyes, acidic indoamine dyes, acidic anthraquinone dyes, indigoids and acidic natural dyes; each of these dyes having at least one sulfonate or carboxylate group. As anionic dyes according to the invention, mention may be made of the dyes of formulas (II), (II '), (III), (III'), (IV), (IV '), (V), (V' ), (VI), (VII), (VIII) and (IX): a) the diaryl anionic azo dyes of formula (II) or (II '): R'9 R9 R10 formula (II) and (II) in which: R7, R8, R9, R10, R'7, R'8, R'9 and R'10, which may be identical or different, represent a hydrogen atom or a group chosen from: alkyl; alkoxy, alkylthio; hydroxy, mercapto; - nitro, - R ° -C (X) -X'-, R ° -X'-C (X) -, R ° -X'-C (X) -X "- with R ° representing an atom of hydrogen, an alkyl or aryl group; X, X 'and X ", which may be identical or different, representing an oxygen, sulfur or NR atom with R representing a hydrogen atom or an alkyl group; - (0) 2S (0 -) -, M + with M + representing a cationic counterion such as alkali metal (Na, K) or alkaline earth metal (Ca); - (0) C0--, M + with M + as previously defined; - R "-S (O) 2-, with R" representing a hydrogen atom, an alkyl group, an aryl group, (di) (alkyl) amino, aryl (alkyl) amino; preferentially a phenylamino or phenyl group; - R "'- S (O) 2 -X'- with R"' representing an alkyl group, optionally substituted aryl, X 'as defined above; (di) (alkyl) amino; aryl (alkyl) amino optionally substituted with one or more groups selected from i) nitro; ii) nitroso; iii) (O) 2 S (O -) -, M + and iv) alkoxy with M + as previously defined; optionally substituted heteroaryl; preferentially a benzothiazolyl group; cycloalkyl; in particular cyclohexyl, - Ar-N = N- with Ar representing an optionally substituted aryl group; preferably a phenyl optionally substituted by one or more alkyl groups, (0) 2S (O -) -, M + or phenylamino; or two contiguous groups R7 with R8 or R8 with R9 or R9 with R10 together form a fused group benzo A '; and R'7 with R'8 or R'8 with R'9 or R'9 with R'10 together form a fused group benzo B '; with A 'and B' optionally substituted with one or more groups selected from i) nitro; ii) nitroso; iii) (0) 2S (0 -) -, M +; iv) hydroxy; (v) mercapto; vi) (di) (alkyl) amino; vii) R ° -C (X) -X'-; viii) R ° - X'-C (X) -; ix) R °-X'-C (X) -X "-; x) Ar-N = N- and xi) aryl (alkyl) amino optionally substituted, with M +, R °, X, X ', X" and Ar as defined previously; W represents a sigma bond s, an oxygen atom, sulfur, or a divalent radical i) -NR- with R as defined above, or ii) methylene-C (Ra) (Rb) - with Ra and Rb identical or different, representing a hydrogen atom or an aryl group, or else Ra and Rb together with the carbon atom carrying them a cycloalkyl spiro; preferentially W represents a sulfur atom or Ra and Rb together form a cyclohexyl; it being understood that the formulas (II) and (II ') comprise at least one (O) 2S (O -) -, M + or carboxylate (O) C (O -) -, M + sulphonate radical on one of the rings A, A ', B, B' or C with M + as defined above; Examples of dyestuffs of formula (II) that may be mentioned are Acid Red 1, Acid Red 4, Acid Red 13, Acid Red 14, Acid Red 18, Acid Red 27, Acid Red 32, Acid Red 33, Acid Red 35. , Red Acid Red 37, Acid Red 40, Acid Red 41, Acid Red 42, Acid Red 44, Acid Red 68, Red Acid Red 135, Acid Red 138, Acid Red 138 Orange 6, Acid Orange 7, Acid Orange 10, Acid Orange 19, Acid Orange 20, Acid Orange 24, Acid Yellow 9, Acid Yellow 36, Acid Yellow 199, Food Yellow 3; Acid Violet 7, Acid Violet 14, Acid Blue 113, Acid Blue 117, Acid Black 1, Acid Brown 4, Acid Brown 20, Acid Black 26, Acid Black 52, Food Black 1, Food Black 2; and by way of example of dyes of formula (II '), mention may be made of Acid Red 111, Acid Red 134 and Acid yellow 38; b) the azo anionic pyrrazolone dyes of formula (III) and (III '): R16 R15 R18 (III) R'20 R'20 R19 R13 R13 formulas (III) and (III') in which: R11, R12 and R13, which may be identical or different, represent a hydrogen atom, a halogen atom, an alkyl group or - (O) 2S (O-), M + with M + as defined previously; R14 represents a hydrogen atom, an alkyl group or a -C (O) O-, M + group with M + as defined above; - R15 represents a hydrogen atom; - R16 represents an oxo group in which case R'16 is absent, or else R15 with R16 together form a double bond; - R17 and R18, identical or different, represent a hydrogen atom, or a group selected from: - (0) 2S (0 -) -, M + with M + as defined above; - Ar-O-S (O) 2- with Ar representing an optionally substituted aryl group; preferentially a phenyl optionally substituted with one or more alkyl groups; R19 and R20 together form either a double bond or an optionally substituted benzo D 'group; - R'16, R'19 and R'20, identical or different, represent a hydrogen atom or an alkyl group, or hydroxy; - R21 represents a hydrogen atom, an alkyl group, or alkoxy; - Ra and Rb, identical or different, are as defined above, preferably Ra represents a hydrogen atom and Rb represents an aryl group; Y represents either a hydroxy group or an oxo group; _ _ represents a single bond when Y is oxo group; and represents a double bond when Y represents a hydroxy group; it being understood that the formulas (III) and (III ') comprise at least one sulfonate group (O) 2S (O -) -, M + on one of the rings D or E, or the formulas (III) and (III') comprise at least minus a carboxylate group (O) C (O -) -, M + with M + as defined above; ; By way of example of dyes of formula (III) mention may be made of Acid Red 195, Acid Yellow 23, Acid Yellow 27 and Acid Yellow 76, and by way of example of dyes of formula (III '), mention may be made of salt Ammonium derivative derived from: Acid Yellow 17; c) the anthraquinone dyes of formula (IV) and (IV '): wherein R22, R24, R25, hydrogen, halogen, or a group selected from: alkyl; hydroxy, mercapto; alkoxy, alkylthio; optionally substituted aryloxy or arylthio, preferably substituted by one or more groups selected from alkyl and (0) 2S (O -) -, M + with M + as defined above; aryl (alkyl) amino optionally substituted by one or more groups selected from alkyl and (0) 2S (O -) -, M + with M + as defined above; - (di) (alkyl) amino; - (di) (hydroxyalkyl) amino - (O) 2S (O -) -, M + with M + as defined above; Z 'represents a hydrogen atom or a group NR28R29 with R28 and R29, which are identical or different, represent a hydrogen atom or a group chosen from: - alkyl; polyhydroxyalkyl such as hydroxyethyl; aryl optionally substituted by one or more groups especially i) alkyl such as methyl, n-dodecyl, n-butyl; ii) (0) 2S (0 -) -, M + with M + as previously defined; iii) R ° -C (X) -X'-, R ° -X'-C (X) -, R ° -X'-C (X) -X "- with R °, X, X 'and X as defined above, preferably R ° represents an alkyl group; cycloalkyl; in particular cyclohexyl; - Z, represents a group selected from hydroxy and NR'28R'29 with R'28 and R'29, identical or different, represent the same atoms or groups as R28 and R29 as defined above; it being understood that the formulas (IV) and (IV ') comprise at least one sulfonate group (O) 2S (O -) -, M + with as defined above; By way of example of dyes of formula (IV), mention may be made of Acid Blue 25, Acid Blue 43, Acid Blue 62, Acid Blue 78, Acid Blue 129, Acid Blue 138, Acid Blue 140, Acid Blue 251 and Acid Green 25. , Acid Green 41, Acid Violet 42, Acid Violet 43, Mordant Red 3; and by way of example of dyes of formula (IV '), mention may be made of the ammonium salt derived from Acid Black 48; NO2 formulas (V) and (V') in which: R30, R3 and R32, which may be identical or different, represent a hydrogen or halogen atom, or a group chosen from: alkyl; alkoxy optionally substituted with one or more hydroxyl groups, alkylthio optionally substituted with one or more hydroxyl groups; hydroxy, mercapto; nitro, nitroso; - (poly) haloalkyl; - R ° -C (X) -X'-, R ° -X'-C (X) -, R ° -X'-C (X) -X "- with R ° X, X 'and X" as defined above; - (0) 2S (0 -) -, M + with M + as defined above; - (0) C0--, M + with M + as previously defined; - (di) (alkyl) amino; - (di) (hydroxyalkyl) amino; heterocycloalkyl such as piperidino, piperazino or morpholino; particularly R 30, R 31 and R 32 represent a hydrogen atom; - Rc and Rd, identical or different, represent a hydrogen atom or an alkyl group; D) the dyes corresponding to the following formulas (V ° and (V '): (R 3 (V) W-ALK-SO 3] u (V) -W is as defined above, W is particularly -NH-; ALK represents a divalent linear or branched C 1 -C 6 alkylene group, especially ALK represents a -CH 2 -CH 2 - group; n is 1 or 2; p represents an integer between 1 and 5 inclusive; an integer inclusively between 1 and 4; u is 0 or 1; when n is 1, J is a nitro or nitroso group; particularly nitro; when n is 2, J represents an oxygen or sulfur atom; or a divalent radical -S (O) m- with m representing an integer 1 or 2, preferentially J represents a radical -SO 2 -; M 'is as defined previously for M +, present or absent represents an optionally substituted benzo group by one or more groups R 30 as defined above, it being understood that the formulas (V) and (V ') co comprise at least one sulfonate group (O) 2 S (O -) -, M + or carboxylate (O) C (O -) -, M + with M + as defined above; By way of example of dyes of formula (V), mention may be made of: Acid Brown 13; Orange Acid 3; by way of example of dyes of formula (V '), mention may be made of: Acid Yellow 1, sodium salt of 2,4-dinitro-1-naphtho-7-sulfonic acid, 2-piperidino acid 5-nitro benzene sulfonic acid, 2 (4'-N, N (2 "-hydroxyethyl) amino-2'-nitro) aniline ethanesulfonic acid, 4-P-hydroxyethylamino-3-nitrobenzene sulfonic acid, e) triarylmethane dyes of formula (VI) (VI) wherein R 43, R 34, R 35 and R 36, which may be identical or different, represent a hydrogen atom or a group chosen from alkyl, optionally substituted aryl and optionally substituted arylalkyl; alkyl and benzyl optionally substituted with a group (O) mS (O -) -, M + with M + and m as defined above; - R37, R38, R39, R40, R41, R42, R43 and R44, which may be identical or different, represent a hydrogen atom or a group selected from: - alkyl; - alkoxy, alkylthio; - (di) (alkyl) amino; - hydroxy, mercapto; - nitro, nitroso; - R ° -C (X) -X'-, R °-X'-C (X) -, R °-X'-C (X) -X "- with R ° representing a hydrogen atom, an alkyl or aryl group; X, X 'and X ", identical or different, representing an oxygen atom, sulfur or NR with R representing a hydrogen atom or an alkyl group; - (0) 2S (0 -) -, M + with M + representing a hydrogen atom or a cationic counterion; - (O) C0--, M + with M + as defined above; - or two contiguous groups R41 with R42 or R42 with R43 or R43 with R44 together form a group fused benzo: I 'with I' optionally substituted with one or more groups selected from i) nitro; ii) nitroso; iii) (0) 2S (0 -) -, M +; iv) hydroxy; v) mercapto; vi) (di) (alkyl) amino; vii) R ° -C (X) -X'-; viii) R °-X'-C (X) -; ix) R °-X'-C (X) -X "-; with M +, R 0, X, X ', X "as defined above, especially R 37 to R 40 represent a hydrogen atom, and R 41 to R 44, which are identical or different, represent a hydroxyl or (O) 2 S (O-) group; -, M +, and when R43 with R44 together form a benzo group, it is preferably substituted by a (O) 2S (O-) - group, it being understood that at least one of the G, H, I or I 'rings comprises at least one sulfonate group (O) 2S (O -) -, M + or carboxylate (O) C (O -) -, M + with M + as defined above: By way of example of dyestuffs of formula (VI) it is possible to mention: Acid Blue 1, Acid Blue 3, Acid Blue 7, Acid Blue 9, Acid Violet 49, Acid Green 50, and f) Derivatives derived from xanthene of formula (VII): R 45 R 47 R 46 48 R 49 Q '- m + 50 5 R51 formula (VII) in which: R45, R46, R47 and R48, identical or a hydrogen atom or a halogen atom; R49, R50, R51 and R52, identical or a hydrogen atom, halogen, or an alkyl, alkoxy, alkylthio group; hydroxy, mercapto, nitro, nitroso; - (0) 2S (0 -) -, M + with M + representing a different hydrogen atom, represent different, represent chosen from: or a cationic counterion; - (0) C0--, M + with M + as previously defined; especially R53 R54, R55 and R48 represent a hydrogen or halogen atom; - G represents an oxygen atom, sulfur or a NRe group with Re as defined above; especially G represents an oxygen atom; L represents an alcoholate O-, M +; a S-, M + thioalcoholate or an NRf group, with Rf representing a hydrogen atom or an alkyl group, and M + as defined above; M + is particularly sodium; L 'represents an oxygen atom, sulfur atom or an ammonium group: N + RfRg, with Rf and Rg, identical or different, representing a hydrogen atom, an optionally substituted alkyl or aryl group; L 'is particularly an oxygen atom or a phenylamino group optionally substituted by one or more alkyl groups or (0) mS (0 -) -, M + with m and M + as defined above; Q and Q ', which may be identical or different, represent an oxygen or sulfur atom; particularly Q and Q 'represent an oxygen atom; M + is as defined above; it being understood that the formula (VII) comprises at least one sulfonate group (O) 2S (O -) -, M + or carboxylate (O) C (O -) -, M + with M + as defined previously; By way of example of dyes of formula (VII), mention may be made of: Acid Yellow 73; Acid Red 51; Acid Red 87; Acid Red 92; Acid Red 95; Purple Acid 9; g) the indole-derived dyes of formula (VIII): (VIII) -R53, R54, R55, R56, R57, R58, R59 and R60, which may be identical or different, represent a hydrogen atom or a group chosen from: alkyl; alkoxy, alkylthio; hydroxy, mercapto; nitro, nitroso; - R ° -C (X) -X'-, R ° -X'-C (X) -, R ° -X'-C (X) -X "- with R ° representing a hydrogen atom, a alkyl or aryl group X, X 'and X ", which may be identical or different, representing an oxygen, sulfur or NR atom with R representing a hydrogen atom or an alkyl group; - (0) 2S (0 -) -, M + with M + as defined above; - (0) C0--, M + with M + as previously defined; - G represents an oxygen atom, sulfur or a NRe group with Re as defined above; especially G represents an oxygen atom; - Ri and Rh, identical or different, represent a hydrogen atom or an alkyl group; it being understood that formula (VIII) comprises at least one sulfonate group (O) 2S (O -) -, M + or carboxylate (O) C (O -) -, M + with M + as defined previously; By way of example of dyes of formula (VIII), mention may be made of the ammonium salt derived from: Acid Blue 74; h) the quinoline-derived dyestuffs of the formula (IX): R 64 R 61 R 61 HO (IX) -R 61 represents a hydrogen atom, a halogen atom or an alkyl group; - R62, R63, and R64, identical or different, represent a hydrogen atom or a group (0) 2S (0 -) -, M + with M + as defined above; - or else R61 with R62, or R61 with R64, together form a benzo group optionally substituted with one or more (0) 2S (O -) - group, M + with M + representing a hydrogen atom or a cationic counterion; it being understood that the formula (IX) comprises at least one sulfonate group (O) 2S (O -) -, M + with M + as defined above; By way of example of dyes of formula (IX), mention may be made of: Acid Yellow 2, Acid Yellow 3 and Acid Yellow 5. More particularly, the anionic direct dyes useful in the invention may be chosen from the following dyes: 45380) Acid Red 87 belonging to the formula (VII) (Cl. 10316) salts of 2,4-dinitro-1-naphtho-7-sulphonic acid belonging to the formula (V ') (Cl 10383) Acid Orange 3 belonging to the formula (V) (Cl. 13015) Acid Yellow 9 / Food Yellow 2 belonging to the formula (II) (Cl, 14780) Direct Red 45 / Food Red 13 belonging to the formula (II) (Cl. 13711) Acid Black 52 belonging to the formula (II) (Cl. 13065) Acid Yellow 36 belonging to the formula (II) (Cl, 14700) 1-hydroxy-2- acid salt (2 ', 4'- xyly1-5-sufonatoazo) -naphthalene-4-sulfonic acid / Food Red 1 belonging to the formula (II) (Cl. 14720) Acid Red 14 / Food Red 3 / Mordant Blue 79 belonging to the formula (II) (C.I. 14805) salt of 4-hydroxy-3 - [(2-methoxy-5-nitrophenyl) l) diaza] -6- (phenylamino) naphthalene-2-sulfonic acid / Acid Brown 4 belonging to the formula (II) (Cl. 15510) Acid Orange 7 / Pigment Orange 17 / Solvent Orange 49 belonging to the formula (II) (Cl, 15985) Food Yellow 3 / Pigment Yellow 104 belonging to the formula (II) (Cl, 16185) Acid Red 27 / Food Red 9 belonging to the formula (II) (Cl, 16230) Acid Orange 10 / Food Orange 4 belonging to the formula (II) (C.1 16250) Acid Red 44 belonging to the formula (II) (C.1 17200 ) Acid Red 33 / Food Red 12 belonging to the formula (II) (C.1 15685) Acid Red 184 belonging to the formula (II) (C.1 19125) Acid Violet 3 belonging to the formula (II) ( CI 18055) salt of 1-hydroxy-2- (4'-acetamido phenylazo) -8-acetamido-naphthalene-3,6-disulfonic acid / Acid Violet 7 / Food Red 11 of formula (II) ( C.1, 18130) Acid Red 135 belonging to the formula (II) (C.1 19130) Acid Yellow 27 belonging to the formula (III) (C.1 19140) Acid Yellow 23 / Food Yellow 4 belonging to the Formula (III) (C.1, 20170) 4 '- (Sulfonato-2 ", 4" -dimethyl) -bis- (2,6-phenylazo) -1,3-dihydroxybenzyl ene / Orange Acid 24 of the formula (II) (C.1. 20470) 1-amino-2- (4'-nitrophenylazo) -7-phenylazo-8-hydroxy-naphthalene-3,6-di-sulfonic acid / Acid Black 1 (II) salt (C.1 23266) (4 - ((4-Methylphenyl) sulfonyloxy) -phenylazo) 2,2'-dimethyl-4 - ((2-hydroxy-5,8-disulfonato) naphthylazo) biphenyl / Acid Red 111 belonging to the formula (II ') (C.1 27755) Food Black 2 belonging to the formula (II) (C.1 25440) 1- (4'-sulfonatophenylazo) -4 - ((2 "-hydroxy-3" -acetylamino-6 ", 8 "-disulfonato) naphthylazo) -6-sulfonatonaphthalene (tetrasodium salt) / Food Black 1 belonging to the formula (II) (CI 42090) Acid Blue 9 belonging to the formula (VI) (CI 60730) Acid Violet 43 belonging with the formula (IV) (Cl 61570) Acid Green of formula (IV) (Cl 62045) salt of 1-amino-4-cyclohexylamino-9,10-anthraquinone 2-sulphonic acid / Acid Blue 62 belonging to the formula (IV) (C.I. 62105) Acid Blue 78 belonging to the formula (IV) (C.1.14710) 4-hydroxy-3 ((2-methoxyphenyl) -azo) salt -1- naphthalene sulfon ique / Acid Red 4 belonging to the formula (II) 2-piperidino-5-nitro benzene sulfonic acid belonging to the formula (V ') Acid 2 (4'-N, N (2 "-hydroxyethyl) amino-2'-nitro ) aniline ethanesulfonic acid of the formula (V ') 4-3-hydroxyethylamino-3-nitrobenzene sulphonic acid belonging to the formula (V') (CI. 42640) Acid Violet 49 belonging to the formula (VI) (CI 42080) Acid Blue 7 belonging to the formula (VI) (C.I. 58005) ammonium salts of 1,2-dihydroxy-3-sulfo-anthraquinone / Mordant Red 3 belonging to the formula (IV) (Cl 62055) salt of 1-amino-9,10-dihydro-9,10-dioxo-4- (phenylamino) 2-anthracene sulfonic acid / Acid Blue 25 belonging to Formula (IV) (IC 14710) 4-hydroxy-3 - ((2-methoxyphenyl) azo) -1-naphthalenesulfonic acid / Acid Red 4 salt of formula (II) Most of these Colorants are described in particular in the Color Index published by The Society of Dyers and Colorists, PO Box 244, Perkin House, 82 Grattan Road, Bradford, Yorkshire, BD1 2JBN England.

The more particularly preferred anionic dyes are the dyes designated in the Color Index under the code CI 58005 (monosodium salt of 1,2-dihydroxy-9,10-anthraquinone-3-sulfonic acid), CI 60730 (monosodium salt of the 2 - [(9,10-dihydro-4-hydroxy-9,10-dioxo-1-anthracenyl) -amino] -5-methyl-benzenesulfonic acid), CI 15510 (monosodium salt of 4 - [(2 1-hydroxy-1-naphthalenyl) -azo] -benzene sulfonic acid), CI 15985 (disodium salt of 6-hydroxy-5 - [(4-sulfophenyl) azo] -2-naphthalenesulfonic acid), CI 17200 (salt disodium 5-amino-4-hydroxy-3- (phenylazo) -2,7-naphthalene disulfonic acid), CI 20470 (disodium salt of 1-amino-2- (4'-nitrophenylazo) -7 phenylazo-8-hydroxy-3,6-naphthalenesulfonic acid), CI 42090 (disodium salt of N-ethyl-N- [44 [4- [ethyl [3-sulfophenyl] methyl] amino] phenyl] (2-sulfophenyl) methylene] -2,5-cyclohexadi-1-ylidene] -3-sulfobenzene-methanaminium hydroxide, internal salt), CI 61570 (disodium salt) 2,2'-[(9,10-dihydro-9,10-dioxo-1,4-anthracenediyl) -diimino] -bis- [5-methyl] -benzene sulfonic acid. Compounds corresponding to the mesomeric, tautomeric forms of structures (II) to (IX) can also be used. More preferentially, the anionic dyes of formula (I) according to the invention are chosen from those of formula (II), (III) and (IV).

According to a particular embodiment of the invention, the direct dyes of the invention are chosen from those corresponding to the following formulas (IIa), (Ma) and (IVa): RI 10 (11a) R'8 R9 R10 Formula (Ha in which: R7, R8, R9, R10, R'7, R'8, R'9 and R'10, which are identical or different, represent a hydrogen atom or a group chosen from: - hydroxy, - nitro , nitroso; - (di) (alkyl) amino; - (0) 2S (0 -) -, M + with M + representing a hydrogen atom, a cationic counterion as defined above; and - Ar-N = N- with Ar representing an optionally substituted aryl group; preferably a phenyl optionally substituted with one or more alkyl groups, (0) 2S (O-) -; M +; or two contiguous groups R7 with R8 or R8 with R9 or R9 with R10 together form a fused group benzo A '; and R'7 with R'8 or R'8 with R'9 or R'9 with R'10 together form a fused group benzo B '; with A 'and B' optionally substituted with one or more groups selected from a) (0) 2S (O -) -, M +; b) hydroxy; c) Ar-N = N-; with M +, and Ar as defined previously; (111a) R13 formula (Ma) in which: - R11, R12 and R13, identical or different, represent a hydrogen atom, halogen, an alkyl group or - (0) 2S (O-), M + with M + as defined previously; R14 represents a hydrogen atom, an alkyl group or a -C (O) O-, M + group with M + as defined above; - R16, R17, R18, R19 and R20, identical or different, represent a hydrogen atom, or an alkyl group, hydroxy or (0) 2S (O -) -, M + with M + as defined above; Y represents either a hydroxy group or an oxo group; _ _ represents a single bond when Y is oxo group; and represents a double bond when Y represents a hydroxy group; it being understood that the formula (IIIa) comprises at least one sulfonate group (O) 2S (O -) -, M + on one of the rings D or E or carboxylate (O) C (O -) -, M +; (1Va) formula (IVa) in which: - Z 'represents a group NR28R29 with R28 representing a hydrogen atom or an alkyl group and R29, representing an aryl group optionally substituted especially by one or more groups chosen from i) alkyl such that methyl and ii) (0) 2S (0 -) -, M + with M + as defined above; - Z, represents a group selected from hydroxy and NR'28R'29 with R'28 and R'29, identical or different, represent the same atoms or groups as R28 and R29 as defined above; it being understood that the formula (IVa) comprises at least one sulfonate group (O) 2S (O -) -, M +; By way of example, mention may be made of the following anionic dyes: Trade name Corresponding structure Acid orange 7 HO el 0, el NI = N IVI ± 'S \\ 0 0 (belongs to formula (II) and (IIa)) Acid ## STR1 ## ## STR1 ## ## STR2 ## + o_ rvi + 0- 0, / S 0- / e igo `s ô '0 \\ - o 1 \ JN- gb HO (belongs to the formula (II) and (lia)) Acid yellow 23 MO-, ps 0 n = N 40, -0 iMi + N 0 Il 0 m + 0 (belongs to the formula (III) and (IIIa)) Acid violet 43 0 OH lable. 0 HN M + O- the S, // .. O O (belongs to the formula (IV) and (IVa)) With M +, identical or different, against cationic ion as defined above According to a particular embodiment of the invention, the invention direct dyes are benzene dyes most often neutral. More preferably, the benzene direct dyes of the invention are chosen from the compounds of formula (X) below: R20 Formula (X) in which: R18 represents an amino radical; an amino radical monosubstituted or disubstituted with a C1-C4 alkyl, C1-C4 monohydroxyalkyl, C2-C4 polyhydroxyalkyl, C1-C4 aminoalkyl, C1-C4 monoalkyl (C1-C4) aminoalkyl, dialkyl (C1- C4) C1-C4 aminoalkyl, C1-C4 ureidoalkyl, aryl, aryl of which the aryl ring is substituted by one or more hydroxyl, carboxyl, amino or dialkyl (C1-C4) amino radicals, - R19 represents an atom of hydrogen; an amino radical; hydroxyl; C1-C4 alkyl; C1-C4 alkoxy; C1-C4 monohydroxyalkyl; C2-C4 polyhydroxyalkyl; C 1 -C 4 monohydroxyalkoxy; C2-C4 polyhydroxyalkoxy; C1-C4 aminoalkoxy; an amino radical monosubstituted or disubstituted with a C 1 -C 4 alkyl, C 1 -C 4 monohydroxyalkyl, C 2 -C 4 polyhydroxyalkyl, C 1 -C 4 aminoalkyl, C 1 -C 4 monoalkyl (C 1 -C 4) alkylamino, dialkyl (C 1 -C 4) alkyl radicals; -C4) amino-C1-C4 alkyl, ureido-C1-C4 alkyl, aryl, aryl whose aryl ring is substituted with one or more hydroxyl, carboxyl, amino or dialkyl (C1-C4) amino radicals; - R20 represents a hydrogen or halogen atom, a C1-C4 alkyl radical, or a nitro group. Among the nitrobenzene dyes of formula (X) above, there may be mentioned in particular: 2-amino-4-methyl-N- (13-hydroxyethypamino-nitrobenzene; 4-N- (13-ureidoethyl) amino nitrobenzene; 4- (N-ethyl N-13-hydroxyethypamino) -N- (13-hydroxyethyl) amino nitrobenzene; 2-N- (13-hydroxyethypamino-5-methyl-nitrobenzene; 5-chloro-3-N- (ethyl) amino); 4-hydroxy nitrobenzene, 5-amino-3-chloro-4-hydroxy-nitrobenzene, 2-N- (7-hydroxypropyl) amino 5-N, N-bis- (13-hydroxyethyl) amino nitrobenzene, 5-hydroxy-2- N- (7-hydroxypropyl) amino nitrobenzene, 1,3-bis- (13-hydroxyethypamino-4-chloro-6-nitro-benzene, 2,4-diamino-nitrobenzene, 3,4-diamino-nitrobenzene, 2,5-diamino nitrobenzene, 3-amino-4-hydroxy-nitrobenzene, 4-amino-3-hydroxy-nitrobenzene, 5-amino-2-hydroxy-nitrobenzene, 2-amino-5-hydroxy-nitrobenzene, 4-amino-3-hydroxy-nitrobenzene; amino 2-hydroxy nitrobenzene, 2-amino-3-hydroxy nitro benzene; 2-amino-5-N- (13-hydroxyethyl) amino nitrobenzene; 2-amino-5-N, N-bis- (13-hydroxyethyl) amino nitrobenzene; 2,5-N, NL (3-hydroxyethyl) amino nitrobenzene; 2-N- (13-hydroxyethypamino) -N, N-bis (13-hydroxyethyl) amino nitrobenzene, 2-amino-5-N- (methyl) amino nitrobenzene, 2-N (methyl) amino 5-N N-bis- (13-hydroxyethyl) amino nitrobenzene, 2- N- (methyl) amino 5- (N-methyl N-13-hydroxyethypamino nitrobenzene) 2,5-N, NL (3-hydroxyethyl) amino nitrobenzene 2-N- (13-hydroxyethyl) amino 5-hydroxy nitrobenzene, 3-methoxy-4-N- (13-hydroxyethyl) -amino-nitrobenzene, 2-N- (methyl) amino-4-hydroxyethyloxy nitrobenzene; 2-amino-3-methyl-nitrobenzene, 2-amino-4- (5-hydroxyethyl) amino-5-amino-nitrobenzene, 2-amino-4-chloro-5-N- (13-hydroxyethyl) amino nitrobenzene, 2-amino-4- methyl 5-N- (13-hydroxyethyl) amino nitrobenzene, 2-amino-4-methyl-N- (methyl) amino nitrobenzene, 2-N- (13-hydroxyethyl) amino-5-methoxy-nitrobenzene; amino 5-13-hydroxyethyloxy nitrobenzene, 2-N- (13-hydroxyethyl) amino nitrobenzene, 3-amino-4-N- (13-hydroxyethypamino nitrobenzene; hydroxyethyloxy 4-N- (13-hydroxyethyl) amino nitrobenzene; 2-N- (methyl) amino 4-13,7-dihydroxypropyloxy nitrobenzene; 2-N- (13-hydroxyethyl) amino 5-13-hydroxyethyloxy nitrobenzene; 2-N- (13-hydroxyethyl) amino 5-13,7-dihydroxypropyloxy nitrobenzene; 2-hydroxy-4-N- (13-hydroxyethyl) amino nitro-benzene; 2-N- (methyl) amino-4-methyl-5-amino nitrobenzene; 2-amino-4-isopropyl 5-N- (methyl) amino nitrobenzene; 2-N- (methyl) amino-5- (N-methyl-N-13,7-dihydroxypropyl) -amino-nitrobenzene; 3-N- (13-hydroxyethyl) amino 4-N- (13-hydroxyethypamino-nitro-benzene; 2-amino-4-methyl-5-N- (13,7-dihydroxypropyl) amino nitrobenzene; methyl 5-hydroxy nitrobenzene, 2-N- (13-hydroxyethyl) amino 4-N- (13-hydroxyethyl) amino nitrobenzene, 2-amino 5-N- (13-aminoethyl) amino nitrobenzene, 2-N - (13-aminoethyl) amino 5-methoxy nitrobenzene, 2-N- (methyl) amino-N- (13-aminoethyl) amino nitrobenzene, 2-N- (13-aminoethyl) amino-N, N- (dimethyl) amino nitrobenzene, 3-amino-4-N- (13-aminoethyl) amino nitrobenzene, 2-amino-4-methyl-5-N- (13-aminoethyl) amino nitrobenzene, 2-N- (13-aminoethyl) ) amino 5-N, Nbis- (13-hydroxyethyl) amino nitrobenzene, 3-3-aminoethyloxy-4-amino nitrobenzene, 2-N- (methyl) amino 5- (N-8-amino-n-butyl) amino nitrobenzene 2-N- (7-amino-n-propyl) amino 5-N, N- (dimethyl) amino nitrobenzene, 3-methoxy-4-N- (13-aminoethyl) amino nitrobenzene; -aminoethyl) amino 5-amino nitrobenz no; 2-amino-4-chloro-5-N- (13-aminoethyl) amino nitrobenzene; 2-N- (13-aminoethyl) amino-4-methoxy nitrobenzene; 2-N- (13-aminoethyl) amino nitrobenzene; 2-N- (13-aminoethyl) amino 5-N- (13-aminoethyl) amino nitrobenzene; 2-N- (13-aminoethyl) amino-3-hydroxyethyloxy nitrobenzene; 3-13-hydroxyethyloxy 4-N- (13-aminoethyl) amino nitrobenzene: 2-amino-5-aminoethyloxy nitrobenzene; 3-hydroxy-4-N- (13-aminoethyl) amino nitrobenzene; 2-N- (13-aminoethyl) amino 5-3-hydroxyethyloxy nitrobenzene; 2-N- (13-aminoethyl) amino-4-hydroxy nitrobenzene; [2-hydroxy-N- (13-hydroxyethyl) amino-3-nitro-6] benzyloxy] -2-ethylamine, and [2-hydroxy-N- (13-hydroxypropyl) amino-3-nitro-6] benzyloxy] -2-ethylamine. . Of the nitrobenzene dyes of formula (X) above, 2-amino-4-methyl-5-N- (13-hydroxyethyl) amino nitrobenzene is particularly preferred; 4-N- (13-ureidoethyl) amino nitrobenzene; 4- (N-ethyl N-13-hydroxyethypamino) -N- (13-hydroxyethyl) amino nitrobenzene; 2-N- (13-hydroxyethypamino-5-methyl-nitrobenzene; 5-chloro-3-N- (ethyl) amino); 4-hydroxy nitrobenzene, 5-amino-3-chloro-4-hydroxy-nitrobenzene, 2-N- (γ-hydroxypropyl) amino 5-N, N-bis (3-hydroxyethyl) amino-nitrobenzene, 5-hydroxy 2-N- (γ-hydroxypropyl) amino nitrobenzene, 1,3-bis- (13-hydroxyethypamino-4-chloro-6-nitro-benzene: 3,4-diamino-nitrobenzene, 2-amino-5-hydroxy-nitrobenzene; amino-3-hydroxy nitrobenzene, 2-amino 5-N- (13-hydroxyethyl) amino nitrobenzene, 2-amino-5-N, N-bis (13-hydroxyethyl) amino nitrobenzene, 2-N- (13-hydroxyethyl) amino nitrobenzene; 5-hydroxyethypamino-N, N-bis (13-hydroxyethyl) amino nitro-benzene, 2-N- (13-hydroxyethyl) amino-5-hydroxy-nitrobenzene, 2-N- (13-hydroxyethyl) -amino amino nitrobenzene, 2-N- (13-aminoethyl) amino 4-methoxy nitrobenzene, and 2-N- (13-aminoethyl) amino 5-13-hydroxyethyloxy nitrobenzene. In a particular embodiment, the direct dye (s) are chosen from porphyrins; phthalocyanines alone or in mixtures. According to a particular embodiment, the direct dye (s) of the invention are cationic. As examples of suitable direct dyes, mention may be made of azo direct dyes; (poly) methine dyes such as cyanines, hemicyanins, and styryl dyes; carbonyls; azinic; nitro (hetero) aryl; tri (hetero) aryl methanes; porphyrins; phthalocyanines and natural direct dyes, alone or in mixtures.

Preferentially, the direct dye (s) contain at least one quaternized cationic chromophore or at least one chromophore carrying a quaternized or quaternizable cationic group. According to a particular embodiment of the invention, the direct dyes comprise at least one quaternized cationic chromophore. For cationic azo dyes, mention may be made especially of those derived from the cationic dyes described in the Kirk Othmer encyclopedia Encyclopedia of Chemical Technology, "Dyes, Azo", J. Wiley & sons, updated on 19/04/2010. Among the azo dyes that may be used according to the invention, mention may be made of the cationic azo dyes described in patent applications WO 95/15144, WO 95/01772 and EP-714954. According to a preferred embodiment of the invention, the direct dye (s) are chosen from cationic dyes called "basic dyes". Mention may be made, among the azo dyes described in the Color Index International 3rd edition, and in particular the following compounds: Basic Red 22, Basic Red 76, Basic Yellow 57, Basic Brown 16, Basic Brown 17. Among the cationic quinone dyes those mentioned in the above-mentioned Color Index International are suitable, and among these, mention may be made, inter alia, of the following dyes: Basic Blue 22, Basic Blue 99 Among the suitable azine dyes, mention may be made of those listed in the Color Index International and, for example, the following dyes: Basic Blue 17, Basic Red 2. Amongst the cationic triarylmethane dyes that may be used according to the invention, mention may be made, in addition to those listed in the Color Index, of the following colorants: Basic Green 1, Basic Violet 3, Basic Violet 14, Basic Blue 7, Basic Blue 26. Cationic dyes may also be mentioned in US 5888252, EP 1133975, WO 03/029359, EP 860636, WO 95/01772, WO 95/15144, EP 71495 4. We can also mention those listed in the encyclopedia "The chemistry of synthetic dye" by K. VENKATARAMAN, 1952, Academic press vol 1 to 7, in the encyclopedia "Kirk Othmer" "Chemical technology", chapter "dyes and Dye Intermediate ", 1993, Wiley and Sons, and in various chapters of the encyclopedia" ULLMANN's ENCYCLOPEDIA of Industrial Chemistry "7th edition, Wiley and Sons. Preferably, the cationic direct dyes are chosen from those derived from azo-type dyes, and hydrazono. According to a particular embodiment, the direct dyes are cationic azo, described in EP 850636, FR 2788433, EP 920856, WO 9948465, FR 2757385, EP 850637, EP 918053, WO 9744004, FR 2570946, FR 2285851, DE 2538363, FR. 2189006, FR 1560664, FR 1540423, FR 1567219, FR 1516943, FR 1221122, DE 4220388, DE 4137005, WO 0166646, US 5708151, WO 9501772, WO 515144, GB 1195386, US 3524842, US 5879413, EP 1062940, EP 1133976, GB 738585, DE 2527638, FR 2275462, GB 1974-27645, Acta Histochem. (1978), 61 (1), 48-52; Tsitologiya (1968), 10 (3), 403-5; Zh. Obshch. Khim. (1970), 40 (1), 195-202; Ann. Chim. (Rome) (1975), 65 (5-6), 305-14; J. Chinese Chem. Soc. (Taipei) (1998), 45 (1), 209-211; Rev. Roum. Chim. (1988), 33 (4), 377-83; Text. Res. J. (1984), 54 (2), 105-7; Chim. Ind. (Milan) (1974), 56 (9), 600-3; Khim. Tekhnol. (1979), 22 (5), 548-53; Ger. Monatsh. Chem. (1975), 106 (3), 643-8; MRL Bull. Res. Dey. (1992), 6 (2), 21-7; Lihua Jianyan, Huaxue Fence (1993), 29 (4), 233-4; Dyes Pigm. (1992), 19 (1), 69-79; Dyes Pigm. (1989), 11 (3), 163-72. Preferably, the cationic direct dye (s) comprise a quaternary ammonium group, more preferably the cationic charge is endocyclic. These cationic radicals are for example a cationic radical: - with an exocyclic charge (di / tri) (C1-C8) alkylammonium, or - with an endocyclic charge such as comprising a cationic heteroaryl group chosen from: acridinium, benzimidazolium, benzobi striazolium, benzopyrazolium, benzopyri dazinium, benzoquinolium, benzothiazolium, benzotriazolium, benzoxazolium, bi- pyridinium bis-tetrazolium dihydrothiazolium, imidazopyridinium, imidazolium, indolium, isoquinolium, naphthoimidazolium, naphthooxazolium, naphthopyrazolium, oxadiazolium, oxazolium, oxazolopyridinium, oxonium, phenazinium, phénooxazolium, pyrazinium, pyrazolium, pyrazoyltriazolium, pyridinium, pyridinoimidazolium, pyrrolium, pyrylium, quinolium, tetrazolium, thiadiazolium, thiazolium, thiazolopyridinium, thiazoylimidazolium, thiopyrylium, triazolium or xanthylium. Mention may be made of the hydrazono cationic dyes of formula (XII) and (XIII), the azo compounds of formulas (XIV) and (XV) below: Het + -C (Ra) = NN (Rb) -Ar, Het + -N (Ra) ) -N = C (Rb) -Ar, Q- (XII) Het + -N = N-Ar, Q-Ar + -N = N-Ar ", Q- (XIV) (XV) formulas (XII) to (XV) in which: - Het + represents a cationic heteroaryl radical, preferably with endocyclic cationic charge such as imidazolium, indolium, or pyridinium, optionally substituted preferably by at least one (C1-C8) alkyl group such as methyl; - Ar + represents an aryl radical; , such as phenyl or naphthyl, with an exocyclic cationic charge preferably ammonium, particularly tri (C 1 -C 8) alkylammonium, such as trimethylammonium, - Ar represents an aryl group, in particular phenyl, which is optionally substituted, preferably with one or more electron-donating groups such as i) (C1-C8) optionally substituted alkyl, ii) (C1-C8) optionally substituted alkoxy, iii) (di) (C1-C8) (alkyl) amino optionally substituted on the one or more alkyl groups by a hydroxyl group, iv) aryl (C1-C8) alkylamino, v) N- (C1-C8) alkyl-N-aryl ( C1-C8) optionally substituted alkylamino or Ar represents a julolidine group; Ar "represents an optionally substituted (hetero) aryl group such as phenyl or pyrazolyl which may be substituted, preferably by one or more (C1-C8) alkyl, hydroxyl or (di) (C1-C8) (alkyl) amino groups, (C1 -C8) alkoxy or phenyl; - Ra and Rb, identical or different, representing a hydrogen atom or a group (C1-C8) alkyl optionally substituted, preferably with a hydroxyl group; - or the substituent Ra with a substituent of Het + and / or Rb with a substituent of Ar together with the atoms bearing them a (hetero) cycloalkyl, especially Ra and Rb, representing a hydrogen atom or a (C1-C4) alkyl group optionally substituted with a hydroxyl group Q - represents an organic or inorganic anionic counterion such as a halide or an alkyl sulphate, especially the azo endocyclic cationic and hydrazone cationic direct dyes; e (XII) to (XV) as defined above. More particularly, the cationic direct dyes of formula (XII) to (XV) with endocyclic cationic charges described in the patent applications WO 95/15144, WO 95/01772 and EP-714954. Preferentially, the following direct dyes: R 4 R-N R 2 R 3 (XIV-1) formulas (XII-1) and (XIV-1) in which: R 1 represents a (C 1 -C 4) alkyl group such as methyl; - R2 and R3, identical or different, represent a hydrogen atom or a group (C1-C4) alkyl such as methyl; and - R4 represents a hydrogen atom or an electron-donor group such as (C1-C8) alkyl optionally substituted, (C1-C8) alkoxy optionally substituted, (di) (C1-C8) (alkyl) amino optionally substituted on the or the alkyl groups with a hydroxyl group; in particular R 4 is a hydrogen atom, - Z is a CH group or a nitrogen atom, preferentially CH 2 - Q- is an anionic counterion as defined above particularly halide such as chloride or an alkylsulfate such as methylsulfate or mesytyl .

In particular, the dyes of formula (XII-1) and (XIV-1) are chosen from Basic Red 51, Basic Yellow 87 and Basic Orange 31 or their derivatives:, CH3 '+ H3C, N-2 H3C + N, ## STR2 ## Basic Red 51 Basic Orange 31 Basic Yellow 87 with anionic counter ion as defined above, especially halide such as chloride or an alkylsulfate such as methylsulfate or mesytyl. According to a particular embodiment of the invention, the direct dyes are fluorescent i.e. they contain at least one fluorescent chromophore as defined above. As fluorescent dyes, mention may be made of the radicals derived from acridine dyes, acridones, benzanthrones, benzimidazoles, benzimidazolones, benzindoles, benzoxazoles, benzopyrans, benzothiazoles, coumarines, difluoro {2 - [(2H-pyrrol-2-ylidene-kN) methyl] -1H-pyrrolato-kNIbores (BODIPY®), diketopyrrolo-pyrroles, fluorindines, (poly) methines (especially cyanines and styryls / hemicyanines), naphthalimides, naphthhanilides, naphthylamine (such as dansyls), oxadiazoles, oxazines, perilones, perinones , perylenes, polyenes / carotenoids, squaranes, stilbenes, xanthenes.

The fluorescent dyes described in documents EP 1133975, WO 03/029359, EP 860636, WO 95/01772, WO 95/15144, EP 714954 and those listed in K's encyclopedia VENKATARAMAN, 1952, Academic press vol 1 to 7, in the encyclopedia "Kirk Othmer" "Chemical technology", chapter "dyes and intermediate Dye", 1993, Wiley and sons, and in various chapters of the encyclopedia "ULLMANN's ENCYCLOPEDIA of Industrial Chemistry "7th edition, Wiley and sounds, in The Handbook - A Guide to Fluorescent Probes and Labeling Technologies, 10th ed. Molecular Probes / Invitrogen - Oregon 2005 distributed over the Internet or in previous print editions. According to a preferred variant of the invention, the fluorescent dye (s) are cationic and comprise at least one quaternary ammonium radical such as those of formula (XV) below: W + - [C (Rc) = C (Rd)] me Ar, Q- (XV) formula (XV) in which: - W + represents a heterocyclic or cationic heteroaryl group, particularly comprising a quaternary ammonium optionally substituted with one or more (C 1 -C 8) alkyl groups optionally substituted, in particular with one or more hydroxyl group; - Ar representing an aryl group such as phenyl or naphthyl, optionally substituted preferably with i) one or more halogen atoms, such as chlorine, fluorine; ii) one or more (C1-C8) alkyl, preferably C1-C4, groups such as methyl; iii) one or more hydroxyl groups; iv) one or more (C1-C8) alkoxy groups such as methoxy; v) one or more hydroxy (C1-C8) alkyl groups such as hydroxyethyl, vi) one or more amino or (di) (C1-C8) alkylamino groups, preferably with the C1-C4 alkyl part optionally substituted with one or several hydroxyl such as (di) hydroxyethylamino, vii) with one or more acylamino groups; viii) one or more heterocycloalkyl groups such as 5- or 6-membered piperazinyl, piperidinyl or heteroaryl such as pyrrolidinyl, pyridinyl and imidazolinyl; - m 'represents an integer inclusive between 1 and 4, particularly m is 1 or 2; more preferably 1; - Rc, Rd, identical or different, represent a hydrogen atom or a group (C1-C8) alkyl optionally substituted, preferably C1-C4, or Rc contiguous with W + and / or Rd contiguous with Ar form with the atoms which bears them a (hetero) cycloalkyl, especially Rc is contiguous with W + and form a (hetero) cycloalkyl such as cyclohexyl; Q - is an organic or inorganic anionic counterion as defined previously. According to a particular embodiment of the invention the direct dyes are natural. These include lawsone, juglone, alizarin, purpurin, carminic acid, kermesic acid, purpurogalline, protocatechaldehyde, indigo, isatin, curcumin, spinulosin, apigenidine , orceines. It is also possible to use extracts or decoctions containing these natural dyes and in particular henna-based poultices or extracts. Preferably, the direct dye (s) are chosen from ionic direct dyes, and in particular from anionic or cationic direct dyes. Even more preferentially, the direct dye (s) are among the cationic direct dyes of formulas (XII) to (XV). The direct dye (s) may represent from 0.001 to 100% by weight, preferably from 0.1 to 50% by weight, better still from 0.1 to 40% by weight relative to the total weight of the aqueous composition.

The direct dye (s) may advantageously represent from 0.001 to 100% by weight, preferably from 0.1 to 50% by weight, better still from 0.1 to 40% by weight relative to the total weight of the aqueous composition.

The aqueous composition may optionally contain one or more chemical oxidizing agents. Preferably, the chemical oxidizing agent (s) are (are) chosen from those described above. Even more preferably, the oxidizing agent is hydrogen peroxide.

This oxidizing agent is advantageously constituted by hydrogen peroxide and especially in aqueous solution (hydrogen peroxide) whose concentration may vary, more particularly from 0.1 to 50% by weight, and even more preferably from 0.5 to 20% by weight. by weight, better from 1 to 15% by weight relative to the oxidizing composition. Preferably, the aqueous composition also contains one or more alkaline agents, especially the alkaline agents as described above. The aqueous oxidizing composition may further comprise one or more thickening agents. According to one embodiment, the dyeing method according to the invention consists in using on said fibers i) a substrate comprising at its surface one or more chemical oxidizing agents, preferably in solid form chosen from peroxygenated salts, such as persulfates, and ii) an aqueous composition comprising one or more direct dyes. According to this embodiment, the direct dye (s) are preferably chosen from anionic or cationic direct dyes and even more preferably from cationic direct dyes of formulas (XII) to (XV). According to a variant of this embodiment, the dyeing method according to the invention consists in using on said fibers i) a substrate comprising at its surface one or more chemical oxidizing agents, preferably in solid form, chosen from peroxygenated salts, such as persulfates, and ii) an aqueous composition comprising (a) one or more direct dyes chosen from cationic direct dyes and even more preferably from cationic direct dyes of formulas (XII) to (XV), ( b) one or more alkaline agents and (c) one or more chemical oxidizing agents, especially hydrogen peroxide. According to another variant of this embodiment, the dyeing process according to the invention consists in using on said fibers i) a substrate comprising one or more chemical oxidizing agents, preferably in solid form, partially covering the surface of said substrate, and ii) an aqueous composition comprising one or more anionic direct dyes. According to these embodiments, the keratinous fibers thus treated are stained with a lightening effect and a coloring effect. More precisely, according to one embodiment, the dyeing method according to the invention consists in bringing the keratinous fibers into contact with the substrate comprising at its surface one or more chemical oxidizing agents, preferably in solid form, and then to be applied on said fibers the aqueous composition containing one or more direct dyes. According to a variant of this embodiment, the dyeing method according to the invention consists in bringing the keratin fibers into contact with the substrate comprising at its surface one or more chemical oxidizing agents preferably in solid form chosen from peroxygenated salts. , such as persulfates, and then applying to said fibers the aqueous composition containing one or more direct dyes. According to this embodiment, the aqueous composition preferably comprises one or more direct dyes, one or more alkaline agents and one or more chemical oxidizing agents. In particular, the keratinous fibers are placed on the surface of the substrate carrying the oxidizing agent (s), that is to say at the place where the surface of the substrate is covered by the oxidizing agent (s), and the aqueous dyeing composition. is then applied to said fibers. The keratinous fibers are thus colored with a lightening effect and a coloring effect. The aqueous composition can be applied using an applicator, in particular a brush, or with the hands. According to this embodiment, after the application of the composition, the locks of hair thus treated can be protected by a paper to protect the other locks that are not treated. According to another embodiment, the dyeing process consists in applying an aqueous composition comprising one or more direct dyes to the keratinous fibers and then in applying to said fibers a substrate comprising at its surface one or more oxidizing agents. In this mode, the order of application between the pretreated substrate and the aqueous composition is therefore reversed with respect to the previous embodiment.

In this embodiment, the keratin fibers are in particular placed on a support, for example the upper surface of a sheet of paper, the aqueous composition is applied to said fibers, and then the substrate pretreated with one or more oxidizing agents is then applied to said fibers. The oxidizing agents present on the substrate surface are thus dissolved to lighten the keratin fibers while the dyes color the coated keratinous fibers. According to this embodiment, the substrate pretreated with one or more oxidizing agents is applied to the keratin fibers treated with the aqueous composition in such a way that the surface containing the oxidizing agent or agents is in contact with the fibers.

The substrate pretreated with one or more oxidizing agents may be applied to the keratinous fibers for a time ranging from 5 to 60 minutes, preferably from 150 to 60 minutes. The aqueous composition containing the direct dye (s) may be applied to the keratin fibers for a time ranging from 5 to 60 minutes, preferably from 15 to 60 minutes. The substrate and the aqueous composition can be applied at ambient temperature (25 ° C.), possibly with a temperature rise of up to 60 ° C.

At the end of the treatment, the human keratin fibers are optionally rinsed with water, optionally washed with a shampoo followed by rinsing with water, before being dried or allowed to dry. Preferably, the substrate is pretreated with an oxidizing composition containing one or more oxidizing agents and one or more alkaline agents and the aqueous composition contains one or more direct dyes, one or more oxidizing agents and optionally one or more alkaline agents. The process for preparing the substrate as described above consists in particular in depositing, by a printing method, an oxidizing composition containing one or more oxidizing agents on the surface of a substrate. In other words, the oxidizing composition is deposited on the surface of a substrate to obtain a substrate containing at its surface one or more chemical oxidizing agents. Preferably, the oxidizing composition comprises one or more oxidizing agents in a content ranging from 0.01 to 100% by weight, preferably from 1 to 50% by weight, better still from 5 to 40% by weight relative to the total weight of said composition.

More preferably, the oxidizing composition comprises one or more alkaline agents. According to one embodiment, the process for preparing the substrate consists in depositing the composition containing the oxidizing agent (s) on the surface of a substrate covered with a deposit of an adhesive composition. This adhesive layer may cover all or part of the substrate. In particular, the adhesive layer may represent a pattern. According to one embodiment, the process for preparing the substrate as described above consists in partially depositing on the surface of a substrate, by a printing method, an oxidizing composition containing one or more oxidizing agents. According to this embodiment, the oxidizing agent (s) are deposited in the form of one or more patterns on the surface of a substrate. In particular, the patterns may be squares, circles, ovals, ellipses, triangles in the form of solid patterns or lines surrounding these patterns. They can also be thick or thin lines, straight, curved, line crossings, representing letters, stylized designs or geometric patterns. They can also be dashed lines or dots. The printing method for depositing the composition on the surface of a substrate may be a screen printing method, a flexographic method, an offset process, or a printing method using an ink jet printer or a printer. laser. The oxidizing composition to be printed on the surface of the substrate may be liquid or in powder form, preferably in powder form. According to a preferred embodiment, the oxidizing composition containing one or more oxidizing agents is printed on the surface of the substrate by means of a laser printer or ink jet. According to this preferred embodiment, the oxidizing composition is in the form of a powder. According to one embodiment, the method for preparing the substrate consists in depositing on the surface of a substrate a composition containing the oxidizing agent (s) and then heating said surface to fix the powder.

In particular, the oxidizing composition is printed by means of a printing process using a laser or ink jet printer on the entire surface of the substrate and then the surface of the substrate is selectively heated to produce one or more patterns on said surface. Preferably, the surface of the substrate is partially heated to create one or more patterns on the surface. According to another embodiment, the process for preparing the substrate consists of depositing the composition containing the oxidizing agent (s) on the surface of a substrate, then removing or rendering ineffective in some parts all or part of the oxidizing agents. In this way, this method makes it possible to lead to the production of one or more patterns on the surface of the substrate. The step of partially removing the oxidizing agent (s) may be accomplished by scraping, buffering, blowing, vacuuming or using an adhesive or wet surface at the locations where it is desired to remove the oxidizing agent (s). The step of rendering all or part of the oxidizing agents on the surface of the substrate ineffective can be carried out by means of a chemical conversion, for example a reduction, or by covering a protective compound. Furthermore, the method of preparing the substrate may further comprise a step of applying a starch film to enhance the strength of the substrate and improve the deposition of the oxidation dye (s) on the surface of the substrate. The starch film may be thin, of the order of 2 g / m 2, or thick, of the order of 70 g / m 2. The substrate thus pretreated according to the preparation method according to the invention preferably dries in a period ranging from 5 minutes to 120 minutes, preferably from 5 minutes to 90 minutes, more preferably from 1 minute to 60 minutes, and more preferably 5 minutes. at 60 minutes.

Advantageously, in this embodiment by printing the substrate is a sheet element as described above. The sheet member is pretreated at its surface by a composition comprising one or more chemical oxidizing agents such as those previously described. The sheet element is thus completely or partially covered at its surface by one or more chemical oxidizing agents. In particular, the chemical oxidizing agent (s) in solid form are preferably printed on the sheet element. The sheet member may be made from a nonwoven material of fibers, especially a cellulose nonwoven or a derivative thereof. In particular, the sheet element may be a kraft type paper which has the advantage of being well printed and leading to precise patterns. Indeed, the colored patterns obtained on the keratinous fibers do not drool following the application of the aqueous composition. The sheet element may be a plastic sheet which has the particular advantage of restoring the power of the coloration which leads to patterns whose coloring is powerful. In addition, the plastic sheet does not absorb the water present in the aqueous composition which makes it possible not to create dry areas under the keratinous fibers during the application of said composition.

According to a first advantageous embodiment, the sheet element is a plastic sheet covered with a thin layer of paper, and in particular with a thickness of less than 50 μm, and more preferably less than 30 μm, paper type. cigarette or a layer of paper that can disintegrate in the presence of water, toilet paper type, a thin layer of hydrophilic material such as cellulose or a hydrophilic silica. According to this embodiment, the thin paper layer allows rapid drying and prevents the coloration from drooling following the application of the aqueous composition which leads to sharp colored patterns. In the case where a support formed of a layer of hydrophilic material is used: the layer of hydrophilic material is typically 5 to 2001.1m thick, which allows rapid drying and prevents the color from drooling following the application of the aqueous composition. This results in particular sharp colored patterns. According to a second advantageous embodiment, the sheet element is a microalveolar sheet, that is to say perforated by holes which are spaced from each other by a plastic material. Thus the oxidizing composition is housed in the holes of the substrate which will better restore the power of direct dyes on keratin fibers after application of the aqueous composition.

The holes are at the surface of the sheet element to a thickness of 10 to 90% of the thickness of the sheet. According to this embodiment, the sheet element also has the advantage of being well printed, better rendering the coloring by leading in particular to patterns colored in a powerful way, not to absorb too much water from the aqueous composition and to minimize the risk that the color does not drool which leads to precisely colored patterns on the keratin fibers.

The following examples serve to illustrate the invention without being limiting in nature.

EXAMPLE Example 1: 1. Preparation of the substrate A sheet of aluminum foil (30 cm × 10 cm) is provided, the surface of which is entirely covered by a double-sided adhesive layer. The entire surface is dusted with a mixture of peroxygenated salts / alkaline agent (mixture of sodium persulphate (10) and potassium (40) / sodium metasilicate (2.5)) which is shaken subsequently to remove loose powder. The amount of powder deposited is about 5 mg / cm 2 on the sheet of aluminum foil. 2. Preparation of the aqueous composition An alkaline aqueous oxidizing composition is prepared from a weight-for-weight mixture, at the time of use, of a composition sold under the name Oxydant Rich INOA 20 volumes based on hydrogen peroxide (6% hydrogen peroxide) and an alkaline composition based on 5% by weight of ammonia at 20% ammonia and 0.5% by weight of a Basic Red 51 cationic direct dye. Procedure A lock of brown hair is applied to the sheet and the lock is wetted with the aqueous composition. After 50 minutes of installation, we clear the wick and rinse. It is found that the treated lock is well colored with a lightening effect and a coloring effect. On the other hand, when all the compounds (peroxygenated salts, hydrogen peroxide, alkaline agents and direct dye) are mixed in the same composition, a slightly colored result is obtained on the lock of hair. EXAMPLE 2 1. Preparation of the substrate A sheet of aluminum foil (30 cm × 10 cm) is placed on which an adhesive tape about 5 cm high is placed. A mixture of peroxygenated salts / alkaline agent (mixture of sodium persulphate (10) and potassium (40) / sodium metasilicate (2.5)) is dusted and shaken subsequently to remove the loose powder. The amount of powder deposited is about 5 mg / cm 2 where the adhesive tape is located on the paper sheet. 2. Preparation of the aqueous composition An alkaline aqueous oxidizing composition is prepared from a weight-for-weight mixture, at the time of use, of a composition sold under the name Oxydant Rich INOA 20 volumes based on hydrogen peroxide and an alkaline composition based on 5% by weight of ammonia at 20% of ammonia and 0.5% by weight of an anionic direct dye Acid Red 52. 3. Procedure A lock of brown hair is applied on the sheet and the wick is wafted with the aqueous composition. After 50 minutes of installation, we clear the wick and rinse. It is noted that treated lock is essentially discolored on its central part, that is to say at the level of the zone which carried the peroxygenated salts, and colored in red on the two other parts (with regard to the two zones which did not bear peroxygenated salts).

Claims (17)

REVENDICATIONS1. A process for lightening the keratinous fibers, in particular human keratinous fibers such as the hair, consisting in using on said fibers i) a substrate comprising at its surface one or more chemical oxidizing agents, and ii) an aqueous composition comprising one or more direct dyes. 2. Method according to claim 1, characterized in that the substrate is a sheet element. 3. Method according to claim 2, characterized in that the sheet element is made of plastic material, in particular thermoplastic, paper, metal, especially aluminum, woven, non-woven non-absorbent fibers, especially cellulose or a derivative thereof, or polyamide 6,6. 4. Method according to claim 2 or 3, characterized in that the sheet element comprises an adhesive layer on which is or are deposited one or more direct dyes. 5. Process according to any one of Claims 1 to 4, characterized in that the chemical oxidizing agent (s) is (are) chosen from chemical oxidants in solid form, preferably urea peroxide, alkali metal bromates or ferricyanides, peroxygenated salts such as, for example, persulfates, perborates and percarbonates of alkali or alkaline earth metals. 6. Process according to any one of claims 1 to 5, characterized in that the oxidizing agent (s) is (are) chosen from peroxygenated salts and even more preferably from persulfates. 7. Method according to any one of claims 1 to 6, characterized in that the oxidizing agent (s) are present on a part of the surface of the substrate and represent patterns having the desired shape. 8. A method according to any one of claims 1 to 7, characterized in that the substrate comprises on the face opposite the side carrying the oxidizing agents or agents a copy of the desired pattern or patterns. 9. Method according to any one of claims 1 to 8, characterized in that the surface of the substrate comprises prior to the deposition of the oxidizing agents or agents one or more patterns. 10. Method according to any one of claims 1 to 9, characterized in that the substrate is transparent. 11. Method according to any one of the preceding claims, characterized in that the substrate further comprises at its surface one or more alkaline agents. 12. Method according to any one of claims 1 to 11, characterized in that the direct dyes are chosen from acridin direct dyes; acridones; anthranthrones; anthrapyrimidines; anthraquinones; azines; (poly) azo, hydrazono or hydrazones, especially arylhydrazones azomethines; benzanthrones; benzimidazoles; benzimidazolones; benzindoles; benzoxazoles; benzopyrans; benzothiazoles; benzoquinones; bisazines; bis isoindolines; carboxanilides; coumarins; cyanines such as azacarbocyanines, diazacarbocyanines, diazahemicyanines, hemicyanines, or tetraazacarbocyanines; diazines; diketopyrrolopyrroles; dioxazines; diphenylamines; diphenylmethanes; dithiazines; flavonoids such as flavanthrones and flavones; fluorines; formazans; indamines; indanthrones; indigoides and pseudoindigoids; indophenols; indoanilines; isoindolines; isoindolinones; isoviolanthrones; lactones; (poly) methines such as dimethines of stilbene or styryl types; naphthalimides; naphthanilides; naphtholactams naphthoquinones; nitro, especially nitro (hetero) aromatic oxadiazoles; oxazines; perilones; perinones; phenazine perylenes; phenoxazine; phenothiazines; phthalocyanine; polyenes / carotenoids; porphyrins; pyranthrones; pyrazolanthrones; pyrazolones; pyrimidinoanthrones; pyronines; quinacridones; quinolines; quinophthalones; squarans; tetrazoliums; thiazines, thioindigo; thiopyronines; triarylmethanes, or xanthenes. 13. Method according to any one of claims 1 to 11, characterized in that the direct dyes are chosen from ionic direct dyes, preferably cationic or anionic. 14. Process according to any one of Claims 1 to 13, characterized in that the direct dyes are chosen from dyes of formula hydrazono of formula (XII) and (XIII), azoids of formulas (XIV), and (XV ): Het + -C (Ra) = NN (Rb) - Het + -N (Ra) -N = C (Rb) -Ar, Q-Ar, Q- (XII) (XIII) Het + -N = N-Ar , Q- Ar + -N = N-Ar ", Q- (XIV) (XV) formulas (XII) to (XV) in which: Het + represents a cationic heteroaryl radical, preferably with an endocyclic cationic charge such as imidazolium, indolium, or pyridinium, optionally substituted with at least one (C 1 -C 8) alkyl group such as methyl; Ar + represents an aryl radical, such as phenyl or naphthyl, with an exocyclic cationic charge, preferably ammonium, particularly a tri (C 1 -C 8) alkylammonium salt; trimethylammonium, Ar represents an aryl group, in particular phenyl, optionally substituted, preferably with one or more groups electrodonorers such as i) (C1-C8) optionally substituted alkyl, ii) (C1-C8) optionally substituted alkoxy, iii) (di) (C1-C8) (alkyl) amino optionally substituted on the alkyl group (s) by a group hydroxyl, iv) optionally substituted aryl (C1-C8) alkylamino, v) N- (C1-C8) alkyl-N-aryl (C1-C8) alkylamino or Ar represents a julolidine group; Ar "represents a (hetero) group optionally substituted aryl such as optionally substituted phenyl or pyrazolyl, preferentially with one or more (C1-C8) alkyl, hydroxyl, (di) (C1-C8) (alkyl) amino, (C1-C8) alkoxy or phenyl groups; Ra and Rb, identical or different, representing a hydrogen atom or a group (C1-C8) alkyl optionally substituted, preferably with a hydroxyl group; or alternatively, the substituent Ra with a substituent of Het + and / or Rb with a substituent of Ar together with the atoms bearing them a (hetero) cycloalkyl; particularly Ra and Rb, representing a hydrogen atom or a (C1-C4) alkyl group optionally substituted by a hydroxyl group; Q- represents an organic or inorganic anionic counterion such as a halide or an alkyl sulphate. 15. Method according to any one of the preceding claims, characterized in that the aqueous composition further comprises one or more oxidizing agents, the oxidizing agent preferably being hydrogen peroxide. 16. Process according to any one of the preceding claims, characterized in that the aqueous composition further comprises one or more alkaline agents. 17. Method according to any one of the preceding claims, characterized in that it consists in applying to said fibers a substrate comprising at its surface one or more oxidizing agents and an aqueous composition comprising one or more direct dyes.