Process for lightening keratin fibers using a peroxygenated salt, an osmolyte and a hydroxylated polycarboxylic acid.

Abstract

Process for lightening keratin fibres using a peroxygenated salt, an osmolyte and a hydroxylated polycarboxylic acid. The invention relates to a process for lightening keratin fibres, preferably human, in particular hair, in which said fibres are treated, in one or more steps, with one or more compositions containing, together or separately: (a) one or more peroxygenated salts; (b) one or more osmolytes; (c) one or more hydroxylated polycarboxylic acids, one of their salts or their mixtures, and (d) optionally, one or more additional oxidising agent(s), other than the peroxygenated salts.

Description

Title of the invention: Process for lightening keratin fibers using a peroxygenated salt, an osmolyte and a hydroxylated polycarboxylic acid.

[0001] The subject of the present invention is a process for lightening keratin fibers, and in particular human keratin fibers such as hair, using one or more peroxygenated salts, one or more osmolytes and one or more hydroxylated polycarboxylic acids, one of their salts or their mixtures.

[0002] In the field of hair lightening, tone height is generally used to characterize the degree or level of lightening. The concept of "tone" is based on the classification of natural shades, a tone separating each shade from the one that immediately follows or precedes it. This definition and classification of natural shades is well known to hairdressing professionals and published in the book "Sciences of Hair Treatments" by Charles ZVIAK 1988, Ed. Masson, pp.215 and 278.

[0003] Tone heights range from 1 (black) to 10 (light blond), with one unit corresponding to one tone; the higher the number, the lighter the shade.

[0004] Lightening thus makes it possible to provide a lighter tone height than the initial natural tone height of the hair.

[0005] The processes used to lighten hair generally consist of using an aqueous composition comprising at least one oxidizing agent, in alkaline pH conditions in the vast majority of cases.

[0006] This oxidizing agent has the role of degrading the melanin in 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 a more significant lightening is desired, in particular a lightening of at least 5 tones, peroxygenated salts, such as persulfates for example, are usually used in the presence of hydrogen peroxide. These peroxygenated salts are contained in compositions which, at the time of use, are mixed with an aqueous composition comprising hydrogen peroxide.

[0007] In order to adjust the pH of the compositions to an alkaline pH to allow the activation of the oxidizing agent, an alkaline agent is used. This alkaline agent also causes swelling of the keratin fiber, with an opening of the scales, which promotes the penetration of the oxidizing agent inside the fiber, and therefore increases the efficiency of the reaction.

[0008] However, the use of alkaline agents and peroxygenated salts can lead to a deterioration in the quality of the hair. The main causes of this deterioration in the quality of the hair are a reduction in its cosmetic properties, such as its shine, and a degradation of its mechanical properties, more particularly a degradation of its mechanical resistance which can also result in an increase in its porosity. The hair is weakened and can become brittle during subsequent treatments such as blow-drying.

[0009] Lightening dark hair is therefore particularly delicate because it requires the use of a significant quantity of peroxygen salts if you want to lighten it significantly, which can weaken or even damage it and lead in particular to hair discipline problems.

[0010] Thus, one of the objectives of the present invention is to provide a method for lightening keratin fibers, preferably human keratin fibers such as hair, which does not have the drawbacks mentioned above, that is to say which is capable of reducing damage to the hair while leading to very good lightening performance.

[0011] This aim and others are achieved by the present invention which therefore has as its subject a process for lightening keratin fibres, preferably human, in particular hair, in which said fibres are treated, in one or more steps, with one or more compositions containing, together or separately: (a) one or more peroxygen salts; (b) one or more osmolytes; (c) one or more hydroxylated polycarboxylic acids, one of their salts or their mixtures, and (d) optionally, one or more additional oxidizing agent(s), other than the peroxygen salts.

[0012] The invention also relates to a composition comprising: (a) one or more peroxygen salts; (b) one or more osmolytes; (c) one or more hydroxylated polycarboxylic acids, one of their salts or their mixtures, and (d) optionally, one or more additional oxidizing agent(s), other than peroxygenated salts, as well as the use of this composition for lightening keratin fibers, and in particular hair.

[0013] The invention also relates to a device with at least two compartments, for lightening keratin fibers, comprising at least a first compartment containing a composition comprising (a) one or more peroxygenated salts, (b) one or more osmolytes and (c) one or more polycarboxylic acids. hydroxylated carboxylic acids, one of their salts or their mixtures, and at least one second compartment containing an oxidizing composition comprising one or more additional oxidizing agent(s), different from the peroxygenated salts.

[0014] The invention also relates to a device with at least two compartments, for lightening keratin fibers, comprising at least a first compartment containing a composition comprising (a) one or more peroxygenated salts, a second compartment comprising (b) one or more osmolytes and (c) one or more hydroxylated polycarboxylic acids, one of their salts or their mixtures, and optionally at least a third compartment containing an oxidizing composition comprising one or more additional oxidizing agent(s), other than the peroxygenated salts.

[0015] The method according to the invention makes it possible to reduce hair damage without impacting the lightening performance. In particular, it makes it possible to obtain a significant level of lightening, up to 9 tones, while reducing hair discipline problems.

[0016] Other objects, characteristics, aspects and advantages of the invention will appear even more clearly on reading the description and examples which follow and on examining the attached drawing, in which:

[0017] [Fig-1] represents the structure of some examples of osmolytes which can be used in the method according to the invention.

[0018] In what follows, and unless otherwise indicated, the limits of a domain of values ​​are included in this domain, in particular in the expressions “between” and “ranging from ... to ...”.

[0019] Furthermore, the expression “at least one” used in the present description is equivalent to the expression “one or more”.

[0020] The terms "lightening" and "bleaching" are synonymous and can be used interchangeably. 1. Compounds

[0021] The process for lightening keratin fibers according to the invention uses the compounds (a), (b), (c) and optionally (d) described below. (a) Peroxygen salts

[0022] The method according to the invention uses one or more peroxygenated salts.

[0023] Preferably, the peroxygenated salts are chosen from persulfates; perborates; percarbonates of alkali metals, alkaline earth metals, or ammonium; magnesium peroxide; and mixtures thereof.

[0024] More preferably, the method according to the invention comprises the use of at least one persulfate.

[0025] Persulfates, also called peroxysulfates, correspond, in the sense of the invention, to the unions (807 peroxomonosulfute union) or S2O82 (peroxo-disulfute union) or to the compounds comprising at least one of these unions.

[0026] Preferably, the persulfutes according to the invention are chosen from peroxodisulfutes.

[0027] According to a preferred embodiment of the invention, the method according to the invention comprises the use of at least one peroxygenated salt chosen from persulfutes; preferably from mollusc persulfutes, mollusc-earth metal persulfutes, ammonium persulfutes, and mixtures thereof; more preferably from (bis)tetrabutylammonium persulfute, buryum persulfute, magnesium persulfute, mollusc persulfute, sodium persulfute, potassium persulfute, ammonium persulfute, and mixtures thereof; even more preferably from sodium persulfute, potassium persulfute, ammonium persulfute, and mixtures thereof; even better among potassium persulfate, ammonium persulfate and their mixtures.

[0028] According to the invention, the peroxygenated salt(s) used as compound (u) in one or more composition(s) useful in the process according to the invention preferably represent(s) from 1 to 70% by weight, more preferably from 5 to 65% by weight, more preferably still from 10 to 60% by weight, and even better from 20 to 55%, or even from 30 to 55% by weight, pure ratio of the total weight of the composition to the total weight of the composition(s) containing them.

[0029] Preferably, the persulfute(s) used as compound (u) in one or more composition(s) useful in the process according to the invention preferably represents from 1 to 70% by weight, more preferably from 5 to 65% by weight, more preferably still from 10 to 60% by weight, and even better from 20 to 55%, or even from 30 to 55% by weight, pure ratio of the total weight of the composition to the total weight of the composition(s) containing them. (b) Osmolytes

[0030] The method according to the invention uses one or more osmolytes.

[0031] Osmolytes are organic molecules, generally of low molecular weight.

[0032] Within the scope of the present invention, the term "osmolyte" does not include carboxylic umin acids, sulfonic umin acids or their salts.

[0033] Osmolytes can be chosen from: (i) curbohydrides, (ii) polyumines, and / or (iii) compounds of formula (I): (R1)(R2)(R3)m-A+-CR4R5-(X)nY (I) in which: - Rb R2 and R3, identical or different, represent a C1-C4 alkyl group, preferably a C1-C2 alkyl group, preferably methyl; - A is N or S; - m is 0 or 1; - n is 0 or 1; - X is a divalent, linear or branched, saturated or unsaturated alkyl group having from 1 to 6 carbon atoms, preferably 1 to 4 carbon atoms, optionally substituted by one or more groups chosen from a hydroxyl (-OH), an amino (-NH2); and - Y is -COO or -OSO3; it being understood that, - when A is S, then m=0 and R4 and R5, identical or different, represent a hydrogen atom or a saturated, unsaturated, linear, branched and / or cyclic hydrocarbon chain, in C1-C10, preferably in C1-C6, more preferably in C1-C4; optionally interrupted by one or more heteroatoms or groups chosen from - S-, -N=, -NH- or -C(NH)- and / or optionally substituted by one or more groups chosen from a hydroxyl (-OH), an amino (-NH2), -SH, -COOH, or -CONH2; - when A is N and m = 0, then R4 represents a hydrogen atom or a saturated, linear or branched C1-C8 alkyl group, preferably a C1-C4 alkyl group; and R5 forms, with the nitrogen atom, a saturated heterocycle comprising from 5 to 8 members, preferably from 5 to 6 members, optionally substituted by one or more groups chosen from hydroxyls or C1-C4 alkyls; and - when A is N and m = 1, then R4 and R5, identical or different, represent a hydrogen atom or a saturated, unsaturated, linear, branched and / or cyclic hydrocarbon chain in C1-C10, preferably in C1-C6, more preferably in C1-C4; optionally interrupted by one or more heteroatoms or groups chosen from -S-, -N=, -NH- or -C(NH)- and / or optionally substituted by one or more groups chosen from a hydroxyl (-OH), an amino (-NH2), -SH, -COOH or -CONH2.

[0034] The carbohydrates which can be used in the process according to the invention include polyols and sugars.

[0035] For example, the polyols may be selected from C2-C16 polyols, such as C2-C12 or C2-C8 polyols. Useful polyols may optionally be selected from diols and triols, and may optionally be linear or branched, saturated or unsaturated, and substituted or unsubstituted. Any stereoisomer of the polyols may be used. In some preferred embodiments, the polyols may be selected from glycols such as ethylene glycol, propylene glycol, butylene glycol, hexylene glycol, pentylene glycol, 1,3-propanediol, diethylene glycol, triethylene glycol, tetraethylene glycol, pentaethylene glycol, dipropylene glycol, caprylyl glycol, glycerin, di-glycerin, ethylhexylglycerin or mixtures of two or more of these. According to other preferred embodiments, the polyols may be selected from propanediol, butanediol, pentanediol, hexanediol, heptanediol, octanediol, 1,2,6-hexanetriol, 1,2,4-butanetriol, trimethylolpropane, 2-butene-1,4-diol, 2-ethyl-1,3-hexanediol, 2-methyl-2,4-pentanediol, caprylyl glycol, 1,2-hexanediol, 1,2-pentanediol, 2-ethyl-2-methyl-1,3-propanediol, 3,3-dimethyl-1,2-butanediol, 2,2-diethyl-1,3-propanediol, 2-methyl-2-propyl-1,3-propanediol, 2,4-Dimethyl-2,4-pentanediol, 2,5-dimethyl-2,5-hexanediol, 5-hexene-1,2-diol, 2-ethyl-1,3-hexanediol, 4-methyl-1,2-pentanediol, or mixtures of two or more of these.

[0036] Preferably, the polyols are chosen from glycerin, mannitol, xylitol, ribitol, pinitol, myoinositol, sorbitol and mixtures thereof.

[0037] For example, the sugars may be selected from C3-C6 monosaccharides, for example pentoses and / or their derivatives. For example, the sugars may optionally be selected from xylose, arabinose, ribose, 2-deoxy-ribose, ribulose, deoxy-ribulose, arabinose, xylulose, allose, altrose, glucose (including dextrose), glucosamine, mannose, gulose, idose, galactose, talose, sorbose, psicose, fructose, tagatose or combinations of two or more of these sugars. According to one embodiment, the sugars may be chosen from disaccharides, for example sucrose (also saccharose), maltose, lactose, cellobiose, trehalose, dextran, or from polysaccharides, for example maltotriose, starch, dextrins, cellulose, glycogen or combinations of two or more of them.

[0038] Preferably, the sugars are chosen from trehalose, glucose, sucrose, fructose, fructans, and mixtures thereof.

[0039] The polyamines which can be used in the process according to the invention can constitute functional groups of primary and / or secondary and / or tertiary and / or quaternary amines. By way of example, the polyamines can be chosen from diamines, triamines, tetramines, pentamines and polymeric polyamines or polyimines, such as, for example, hexamethylenediamine, diethylenetramine, diethylenetriamine, polyethyleneimine (PEI), polyvinylamine, polyetheramine, polylysine, ethylenediamine, 1,3-diaminopropane, ca-daverine, spermidine, spermine, putrescine, tetraethylmethylenediamine, triethylenetetramine, or combinations of two or more of these elements.

[0040] Preferably, the polyamines are chosen from putrescine, spermidine, spermine and mixtures thereof.

[0041] Preferably, the method according to the invention uses at least one osmolyte chosen from the compounds of formula (I).

[0042] Preferably, the method according to the invention uses at least one osmolyte chosen from the compounds of formula (I) which are derivatives of zwitterionic amino acids carrying a quaternary ammonium group and comprising in total from 1 to 12 carbon atoms, better still from 2 to 10 carbon atoms, better still from 3 to 8 carbon atoms.

[0043] Preferably, the process according to the invention uses at least one compound of formula (I) in which R 1 and R 2 are identical and represent a methyl.

[0044] Preferably, the method according to the invention uses at least one compound of formula (I) in which A is N.

[0045] Preferably, the method according to the invention uses at least one compound of formula (I) in which Y is -COO.

[0046] More preferably, the process according to the invention uses at least one compound of formula (I) in which R 1 and R 2 are identical and represent a methyl, A is N and Y is -COO.

[0047] Preferably, the process according to the invention uses at least one compound of formula (I) in which R3 is a methyl.

[0048] Preferably, X is a divalent, linear or branched, saturated or unsaturated alkyl group having from 1 to 6 carbon atoms, preferably 1 to 4 carbon atoms, preferably 1 to 2 carbon atoms.

[0049] Preferably, the process according to the invention uses at least one compound of formula (I) in which X is a divalent, linear or branched, preferably saturated alkyl group having from 1 to 6 carbon atoms, preferably 1 to 4 carbon atoms, optionally substituted by a group chosen from a hydroxyl or an amino.

[0050] In a particularly preferred manner, the process according to the invention uses at least one compound of formula (I) in which X is a divalent, linear or branched, preferably saturated alkyl group having from 1 to 6 carbon atoms, preferably 1 to 4 carbon atoms, preferably 1 to 2 carbon atoms (unsubstituted), such as methylene or ethylene.

[0051] Preferably, the method according to the invention uses at least one compound of formula (I) in which R4 and R5, which may be identical or different, may be chosen from a hydrogen atom, a saturated, linear or branched alkyl group, C1-C10, preferably C1-C6, more preferably C1-C4; a phenyl group; a benzyl group; an alkyl group substituted by a cyclic group (saturated or not, mono or bicyclic); a cyclic group (saturated or not, mono or bicyclic) substituted by an alkyl group; all these groups being optionally in interrupted by one or more heteroatoms or groups chosen from -S-, -N=, -NH- or -C(NH)- and / or optionally substituted by one or more groups chosen from hydroxyl (-OH), amino (-NH2), -SH, -COOH, -CONH2.

[0052] Preferably, the process according to the invention uses at least one compound of formula (I) in which R4 and R5 can be chosen from a hydrogen atom, a saturated, linear or branched C1-C6, preferably C1-C4 alkyl; optionally substituted by a group chosen from hydroxyl (-OH), amino (-NH2), -COOH or -CONH2.

[0053] In a particularly preferred manner, when A is N and m = 0, R5 forms, with the nitrogen atom, a saturated heterocycle comprising from 5 to 8 members, preferably 5 to 6 members, optionally substituted by a hydroxyl group.

[0054] Preferably again, the process according to the invention uses at least one compound of formula (I) in which Ri = R2 = methyl, A is N, Y is COO, and X, if present, is a divalent alkyl group which may be linear or branched, saturated or unsaturated, having from 1 to 6 carbon atoms, preferably from 1 to 4 carbon atoms, more preferably from 1 to 2 carbon atoms.

[0055] Preferably, the process according to the invention uses at least one compound of formula (I) in which R4 represents a hydrogen atom.

[0056] Preferably, the process according to the invention uses at least one compound of formula (I) in which R5 represents a hydrogen atom or a saturated, linear or branched C1-C6, preferably C1-C4, hydrocarbon chain, optionally substituted by one or more groups chosen from a hydroxyl (-OH), an amino (-NH2), -SH, -COOH or -CONH2.

[0057] Preferably, the process according to the invention uses at least one compound of formula (I) in which R1 = R2 = R3 = methyl; A is N; Y is COO; X is a divalent, linear or branched, preferably saturated alkyl group having from 1 to 4 carbon atoms, optionally substituted by a group chosen from a hydroxyl or an amino, preferably 1 to 2 carbon atoms (unsubstituted), such as methylene or ethylene; R4 is hydrogen; and R5 forms, with the nitrogen atom, a saturated heterocycle comprising from 5 to 8 members, preferably 5 to 6 members, optionally substituted by a hydroxyl group.

[0058] Preferably, the compounds of formula (I) are chosen from one of the compounds indicated in [Fig.l].

[0059] Preferably, the compounds of formula (I) are chosen from valine betaine, glutamic acid betaine, glutamine betaine, trimethyllysine, glycine betaine (trimethylglycine), histidine betaine, alanine betaine, choline sulfate, pipecolic acid betaine, proline betaine, hydroxyproline betaine, tyrosine betaine, phenylalanine betaine, tryptophan betaine, leucine betaine, isoleucine betaine, dimethylsulfoniopropionate and mixtures thereof.

[0060] In a particularly preferred manner, the method according to the invention uses trimethylglycine (also called here glycine betaine or "betaine"), optionally in combination with at least one additional osmolyte, for example at least one additional compound of formula (I), preferably chosen from the compounds indicated in [Fig.l].

[0061] According to the invention, the osmolyte(s) used as compound (b) in one or more composition(s) useful in the process according to the invention preferably represents from 0.05 to 20% by weight, preferably from 0.1 to 10% by weight, more preferably from 0.5 to 8% by weight, more preferably still from 0.8 to 5% by weight, better still from 1.0 to 3% by weight, relative to the total weight of the composition(s) containing them.

[0062] Preferably, the trimethylglycine used as compound (b) in one or more composition(s) useful in the process according to the invention preferably represents from 0.05 to 20% by weight, preferably from 0.1 to 10% by weight, more preferably from 0.5 to 8% by weight, more preferably still from 0.8 to 5% by weight, better still from 1.0 to 3% by weight, relative to the total weight of the composition(s) containing them. (c) Hydroxylated polycarboxylic acids

[0063] The method according to the invention uses one or more hydroxylated polycarboxylic acids.

[0064] Preferably, the hydroxylated polycarboxylic acid(s) is(are) chosen from the hydroxylated polycarboxylic acids of the following formula (II): r OH® ] HO LO

[0065] Formula (II) in which: - n is an integer between 1 and 5, better between 1 and 3, preferably n=1 or 2, more preferably n=2; - A is a multivalent, saturated or unsaturated, linear, branched, cyclic, or even aromatic hydrocarbon group, comprising from 1 to 6 carbon atoms, preferably from 1 to 4 carbon atoms, substituted by one or more hydroxyl (OH) groups.

[0066] Preferably, A is a multivalent (C1-C6)alkylene, better (C2-C4)alkylene, or phenylene group, substituted by one or more hydroxy groups.

[0067] Preferably, the hydroxylated polycarboxylic acids of formula (II) are alpha-hydroxy acids, for which A is a (C1-C6)alkylene group, better (C2-C4)alkylene, or phenylene, substituted by 1 or 2 hydroxy groups, preferably 1 hydroxy group; and n = 1 to 2.

[0068] Mention may in particular be made of the hydroxylated polycarboxylic acids of formula (II) in which n = 1 or 2, and A is a di- or trivalent (Cl-C6)alkyl group, better still (C2-C4)alkyl, substituted by one or more hydroxyl groups, in particular 1 or 2 OH, preferably 1 OH.

[0069] Preferably, the hydroxylated polycarboxylic acids can be chosen from: - citric acid (n=2 and trivalent A = -CH2-CHOH-CH2- ); - malic acid (n=1 and divalent A = -CH2-CH(OH)-); and - tartaric acid (n=1 and divalent A = -CH(OH)-CH(OH)-).

[0070] Even more preferably, the hydroxylated polycarboxylic acid, one of its salts or their mixtures is chosen from citric acid, one of its salts and their mixtures.

[0071] According to the invention, the hydroxylated polycarboxylic acid(s), one of their salts or their mixtures used as compound (c) in one or more composition(s) useful in the process according to the invention preferably represents from 0.05 to 20% by weight, preferably from 0.1 to 10% by weight, more preferably from 0.5 to 8% by weight, even more preferably from 0.8 to 5% by weight, better still from 1.0 to 3% by weight, relative to the total weight of the composition(s) containing them.

[0072] Preferably, the citric acid, one of its salts or their mixtures used as compound (c) in one or more composition(s) useful in the process according to the invention represents from 0.05 to 20% by weight, preferably from 0.1 to 10% by weight, more preferably from 0.5 to 8% by weight, more preferably still from 0.8 to 5% by weight, better still from 1.0 to 3% by weight, relative to the total weight of the composition(s) containing them.

[0073] Preferably, the citric acid used as compound (c) in one or more composition(s) useful in the process according to the invention represents from 0.05 to 20% by weight, preferably from 0.1 to 10% by weight, more preferably from 0.5 to 8% by weight, more preferably still from 0.8 to 5% by weight, better still from 1.0 to 3% by weight, relative to the total weight of the composition(s) containing them. (d) Chemical oxidizing agents

[0074] According to the present invention, the method can use one or more chemical oxidizing agents other than peroxygenated salts.

[0075] Preferably, the method according to the invention uses one or more chemical oxidizing agents other than peroxygenated salts.

[0076] Preferably, the chemical oxidizing agent(s) are chosen from hydrogen peroxide, hydrogen peroxide generating systems other than peroxygenated salts and mixtures thereof.

[0077] Hydrogen peroxide generating systems other than peroxygen salts may be chosen from urea peroxide, polymeric complexes capable of releasing hydrogen peroxide, oxidases and mixtures thereof.

[0078] As an example of polymer complexes capable of releasing hydrogen peroxide, mention may be made of polyvinylpyrrolidone / H2O2, in particular in powder form, and the other polymer complexes described in US 5,008,093; US 3,376,110 and US 5,183,901.

[0079] Oxidases can produce hydrogen peroxide in the presence of a suitable substrate, such as glucose in the case of glucose oxidase or uric acid with uricase.

[0080] Preferably, the method uses hydrogen peroxide as the chemical oxidizing agent.

[0081] Furthermore, the composition(s) comprising hydrogen peroxide or hydrogen peroxide generating system may also contain various adjuvants conventionally used in compositions for dyeing keratin fibres as defined below.

[0082] According to a particular embodiment of the invention, the chemical oxidizing agent(s) other than the peroxygenated salts preferably represent from 0.01% to 30% by weight, preferentially from 0.1 to 20% by weight, better still from 1 to 15% by weight relative to the total weight of the composition or compositions containing it or them.

[0083] According to a particular embodiment of the invention, the hydrogen peroxide preferably represents from 0.01% to 30% by weight, preferentially from 0.1 to 20% by weight, better still from 1 to 15% by weight relative to the total weight of the composition or compositions containing it or them.

[0084] The method according to the invention can also use one or more of the following compounds. Amino acid compound(s)

[0085] The method according to the invention can optionally use one or more amino acid type compound(s).

[0086] By amino acid type compound, is meant in the sense of the present invention an organic compound comprising one or more carboxylic acid and / or sulfonic acid functions, and one or more amine functions, the amine function(s) possibly being intra-cyclic, optionally in salt form.

[0087] Amino acid type compounds are different from the osmolytes described previously.

[0088] Preferably, the amino acid type compound(s) are chosen from amino acid type compounds comprising only one or more carboxylic acid functions (therefore not comprising a sulfonic acid function) and / or their salts. Said compounds are also called amino acid type compounds car- carboxylic and are particularly preferred.

[0089] When the method according to the invention uses one or more amino acid type compound(s), the method according to the invention preferably uses one or more amino acid type compounds chosen from the compounds corresponding to the formula (HD below and / or their salts.

[0090] Amino acid type compounds can therefore correspond to the formula (III): COOH (IH) H....... C ....... N(H)P R in which p is an integer equal to 1 or 2, it being understood that: - when p = 1, R forms with the nitrogen atom a saturated heterocycle comprising from 5 to 8 members, preferably 5 members, this cycle possibly being substituted by one or more groups chosen from hydroxyl or (Cl-C4)alkyl; - when p = 2, R represents a hydrogen atom or a (Cl-C12)alkyl group, preferably (Cl-C4)alkyl, linear or branched, saturated, optionally interrupted by one or more heteroatoms or groups chosen from -S-, -NH- or -C(NH)- and / or optionally substituted by one or more groups chosen from hydroxyl (OH), amino (NH2), -SH, -COOH, -CONH2 or -NH-C(NH)-NH2.

[0091] Preferably, when p = 1, R forms with the nitrogen atom a saturated heterocycle comprising 5 members, this cycle not being substituted.

[0092] Preferably, p=2.

[0093] Preferably, when p = 2, R represents a hydrogen atom or a (Cl-C4)alkyl group, linear or branched, saturated, optionally interrupted by a heteroatom -S- and / or optionally substituted by one or two groups chosen from hydroxyl, amino or -NH-C(NH)-NH2.

[0094] Preferably, p=2 and R represents a hydrogen atom.

[0095] The amino acid type compounds may also be a salt of a compound of formula (III).

[0096] These salts include salts with organic or mineral bases, for example alkali metal salts, such as lithium, sodium, potassium salts; alkaline earth metal salts such as magnesium, calcium salts and zinc salts.

[0097] The amino acid compounds may be in the form of an optical isomer of L, D or DL ​​configuration, preferably of L configuration.

[0098] As examples according to the present invention of compounds in the form of an optical isomer of L configuration, mention may be made of L-proline, L-methionine, L- serine, L-arginine and L-lysine.

[0099] Preferably, the amino acid compound(s) according to the invention are chosen from glycine, proline, methionine, serine, arginine, lysine, their salts (in particular of alkali or alkaline-earth metals, or of zinc) and their mixtures.

[0100] Preferably, the amino acid type compound(s) according to the invention are chosen from glycine, proline, methionine, serine, arginine, their salts and their mixtures.

[0101] Even better, the amino acid type compound is chosen from glycine, arginine, their salts (in particular of alkali or alkaline-earth metals, or of zinc) and their mixtures.

[0102] Preferably, the amino acid compound is arginine.

[0103] When they are present, the compound(s) of amino acid type, preferably of carboxylic amino acid type, used in one or more composition(s) useful in the process according to the invention preferably represent(s), from 0.01% to 20% by weight, preferably from 0.05 to 10% by weight, more preferably from 0.1 to 5% by weight, better still from 0.2 to 2% by weight, relative to the total weight of the composition(s) containing them.

[0104] In particular, when they are present, the amino acid compound(s) chosen from glycine, proline, methionine, serine, arginine, lysine, their salts and their mixtures, used in one or more composition(s) useful in the process according to the invention preferably represent(s) from 0.01% to 20% by weight, preferably from 0.05 to 10% by weight, more preferably from 0.1 to 5% by weight, better still from 0.2 to 2% by weight, relative to the total weight of the composition(s) containing them. Alkaline agent

[0105] The method according to the invention can also use one or more alkaline, mineral, organic or hybrid agent(s).

[0106] The alkaline agents according to the invention are different from the osmolytes and amino acids previously described.

[0107] Preferably, the method according to the invention uses one or more alkaline agents.

[0108] For the purposes of the present invention, the terms “alkaline agent” or “alkalizing agent” are used interchangeably.

[0109] The mineral alkalizing agent(s) are preferably chosen from ammonia, alkali carbonates or bicarbonates such as sodium (hydrogen)carbonate and potassium (hydrogen)carbonate, ammonium (hydrogen)carbonate, alkali or alkaline earth metal phosphates such as sodium phosphates or potassium phosphates, hy sodium or potassium oxides, silicates or metasilicates of alkali or alkaline earth metals such as sodium silicate, sodium metasilicate and their mixtures.

[0110] The organic alkalizing agent(s) are preferably chosen from alkanolamines, organic amines other than alkanolamines, oxyethylenated and / or oxypropylenated ethylenediamines, 1,3 diaminopropane, spermine, spermidine and mixtures thereof.

[0111] By alkanolamine is meant an organic amine comprising a primary, secondary or tertiary amine function, and one or more linear or branched C1-C8 alkyl groups carrying one or more hydroxyl radicals.

[0112] Particularly suitable for carrying out the invention are organic amines chosen from alkanolamines such as mono-, di- or tri-alkanolamines, comprising one to three hydroxyalkyl radicals, identical or not, in C1-C4.

[0113] In particular, the alkanolamine(s) are chosen from monoethanolamine (MEA), diethanolamine, triethanolamine, monoisopropanolamine, diisopropanolamine, N,N-dimethylethanolamine, 2-amino-2-methyl-1-propanol, triisopropanolamine, 2-amino-2-methyl-1,3-propanediol, 3-amino-1,2-propanediol, 3-dimethylamino-1,2-propanediol, tris-hydroxymethylaminomethane and mixtures thereof.

[0114] The organic amine may also be chosen from heterocyclic organic amines. In particular, in addition to histidine already mentioned in the amino acids, mention may be made of pyridine, piperidine, imidazole, triazole, tetrazole, benzimidazole. The organic amine may also be chosen from amino acid dipeptides. As amino acid dipeptides which may be used in the present invention, mention may in particular be made of carnosine, anserine and balenine. The organic amine may also be chosen from compounds comprising a guanidine function. As amines of this type other than arginine which may be used in the present invention, mention may in particular be made of creatine, creatinine, 1,1-dimethylguanidine, 1,1-diethylguanidine, glycocyamine, metformin, agmatine, n-amidinoalanine, 3-guanidinopropionic acid, 4-guanidinobutyric acid and 2-([amino(imino)methyl]amino)ethane-1-sulfonic acid.)

[0115] As hybrid compounds, it is possible in particular to use guanidine carbonate or monoethanolamine hydrochloride.

[0116] The alkaline agent(s) useful according to the invention is (are) preferably chosen from alkanolamines such as monoethanolamine, diethanolamine, triethanolamine; ammonia, carbonates or bicarbonates such as sodium (hydrogen)carbonate, potassium (hydrogen)carbonate, ammonium (hydrogen)carbonate, silicates or metasilicates of alkali or alkaline earth metals such as silicate and sodium metasilicate and mixtures thereof, more preferably among silicates or metasilicates of alkali or alkaline earth metals, such as sodium silicate and metasilicate, and carbonates or bicarbonates such as ammonium (hydrogen)carbonate, and mixtures thereof, better still among silicates or metasilicates of alkali or alkaline earth metals, such as sodium silicate and metasilicate.

[0117] When they are present, the alkaline agent(s) used in one or more composition(s) useful in the process according to the invention preferably represent(s) from 0.1 to 50% by weight, more preferably from 1 to 40% by weight, better still from 5 to 35% by weight, better still from 10 to 30% by weight, relative to the total weight of the composition(s) containing them.

[0118] When present, the alkaline agent(s) chosen from alkali or alkaline earth metal silicates or metasilicates used in one or more composition(s) useful in the process according to the invention preferably represent(s) from 0.1 to 50% by weight, more preferably from 1 to 40% by weight, better still from 5 to 35% by weight, better still from 10 to 30% by weight, relative to the total weight of the composition(s) containing them. Direct dyes

[0119] The method according to the invention can optionally use one or more direct dye(s).

[0120] By "direct dyes" is meant natural and / or synthetic dyes, different from oxidation dyes. These are dyes which will diffuse superficially on the fiber. They can be ionic, for example cationic or anionic, or non-ionic.

[0121] Examples of suitable direct dyes that may be mentioned include azo direct dyes; (poly)methine dyes such as cyanines, hemicyanines and styryls; carbonyl dyes; azine dyes; nitro(hetero)aryl dyes; tri(hetero)arylmethane dyes; porphyrin dyes; phthalocyanine dyes and natural direct dyes, alone or in mixtures.

[0122] The direct dyes can be selected from cationic direct dyes.

[0123] Among the cationic direct dyes, mention may be made of dyes with endocyclic azo ethydrazono cationic charges, including: Basic Red 51, Basic Yellow 87 and Basic Orange 31 or their derivatives. Mention may also be made of anthraquinone cationic direct dyes, in particular HC Blue 16 and HC Blue 17.

[0124] The direct dyes can be selected from anionic direct dyes. Anionic direct dyes are dyes commonly referred to as "acid" direct dyes due to their affinity for alkaline substances. Anionic direct dyes are understood to mean any direct dye comprising in its structure at least one CO2 R or SO3 R substituent, where R denotes a hydrogen atom or a cation of a metal or an amine, or an ammonium ion. Anionic dyes may be chosen from acid nitrate direct dyes, acid azo dyes, acid azine dyes, acid triarylmethane dyes, acid indoamine dyes, acid anthraquinone dyes, indigoids and natural acid dyes.

[0125] For example, we can cite:

[0126] a) diaryl anionic azo dyes;

[0127] À titre d’exemple, on peut citer : Acid Red 1, Acid Red 4, Acid Red 13, Acid Red 14, Acid Red 18, Acid Red 27, Acid Red 28, Acid Red 32, Acid Red 33, Acid Red 35, Acid Red 37, Acid Red 40, Acid Red 41, Acid Red 42, Acid Red 44, Pigment Red 57, Acid Red 68, Acid Red 73, Acid Red 135, Acid Red 138, Acid Red 184, Food Red 1, Food Red 13, Acid Orange 6, Acid Orange 7, Acid Orange 10, Acid Orange 19, Acid Orange 20, Acid Orange 24, Acid Yellow 6, 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 ; Food Yellow 3 ou sunset yellow ; ou Acid Red 111, Acid Red 134, Acid yellow 38 ;

[0128] b) les colorants azoïques anioniques pyrrazolone, y compris : Acid Red 195, Acid yellow 23, Acid Yellow 27, Acid Yellow 76 ou Acid Yellow 17 ;

[0129] c) anthraquinone dyes, including: Acid Blue 25, Acid Blue 43, Acid Blue 62, Acid Blue 78, Acid Blue 129, Acid Blue 138, Acid Blue 140, Acid Blue 251, Acid Green 25, Acid Green 41, Acid Violet 42, Acid Violet 43, Mordant Red 3; EXT Violet No. 2; and Acid Black 48;

[0130] d) Nitro dyes, including: Acid Brown 13; Acid Orange 3; Acid Yellow 1, 2,4-dinitro-1-naphthol-7-sulfonic acid sodium salt, 2-piperidino 5-nitrobenzene sulfonic acid, 2-(4'-N,N(2''-hydroxyethyl)amino-2'-nitro)aniline ethane sulfonic acid, 4-[3-hydroxyethylamino-3-nitrobenzene sulfonic acid; EXT D&C Yellow 7;

[0131] e) triarylmethane dyes, including: Acid Blue 1; Acid Blue 3; Acid Blue 7, Acid Blue 9; Acid Violet 49; Acid Green 3; Acid Green 5; Acid Green 50; Tetra-bromophenol Blue.

[0132] f) xanthene-derived dyes, including: Acid Yellow 73; Acid Red 51; Acid Red 52, Acid Red 87; Acid Red 92; Acid Red 95; Acid Violet 9;

[0133] g) indole-derived dyes, including: Acid Blue 74;

[0134] h) quinoline-derived dyes, including: Acid Yellow 2, Acid Yellow 3 and Acid Yellow 5.

[0135] Among the natural direct dyes used according to the invention are lawsone, juglone, alizarin, purpurin, carminic acid, kermesic acid, purpu-rogalline, protocatechaldehyde, indigo, isatin, curcumin, spinulosin, apigenin, orceins. Extracts or decoctions containing these natural dyes can also be used, including poultices or henna-based extracts.

[0136] Preferably, the direct dyes are chosen from anionic direct dyes.

[0137] More preferably, the direct dye(s) are chosen from blue or violet dyes such as Acid Violet 7, Acid Violet 14, Acid Blue 113, Acid Blue 117, Acid Blue 25, Acid Blue 43, Acid Blue 62, Acid Blue 78 Acid Blue 129, Acid Blue 138, Acid Blue 140, Acid Blue 251, Acid Violet 42, Acid Violet 43 (also called Violet EXT No. 2), Acid Blue 1; Acid Blue 3; Acid Blue 7; Acid Blue 9; Acid Violet 49, Acid Violet 9, Acid Blue 74, Basic Blue 6, Basic Blue 7, Basic Blue 9, Basic Blue 26, Basic Blue 41, Basic Blue 77 (or HC Blue 15), Basic Blue 99, Basic Violet 1, Basic Violet 2, Basic Violet 3, Basic Violet 10, Basic Violet 14, HC Blue 16, HC Blue 17.

[0138] The preferred direct dyes are Violet EXT No. 2, Acid Blue 62, Acid Blue 9, Basic Violet 2, HC Blue 16, HC Blue 17 and Tetrabromophenol Blue, more preferably Violet EXT No. 2, Acid Blue 62, Acid Blue 9, HC Blue 16, HC Blue 17 and Tetrabromophenol Blue.

[0139] When present, the direct dye(s) used in one or more composition(s) useful in the process according to the invention preferably represent(s) from 0.001 to 10% by weight, preferably from 0.005 to 5% by weight, more preferably from 0.001% to 3% by weight, relative to the total weight of the composition(s) containing them. Surfactants

[0140] The method according to the invention can also use one or more surfactants.

[0141] These may preferably be chosen from anionic surfactants, amphoteric surfactants, non-ionic surfactants, cationic surfactants and / or mixtures thereof.

[0142] Preferably, the method according to the invention uses one or more surfactants.

[0143] Preferably, the method according to the invention uses one or more anionic surfactants.

[0144] The term “anionic surfactant” means a surfactant comprising only anionic groups as ionic or ionizable groups. These anionic groups are preferably chosen from the groups CO2H, CO2, SO3H, SO3, OSO3H, OSO3, H2PO3, HPO3, PO32, H2PO2, HPO2, PO22, POH and PO.

[0145] As examples of anionic surfactants that can be used in the process according to the invention, mention may be made of alkyl sulfates, alkyl ether sulfates, alkylamidoether sulfates, alkylarylpolyether sulfates, monoglyceride sulfates, alkylsulfonates, alkylamidesulfonates, alkylarylsulfonates, alpha-olefin sulfonates, paraffin sulfonates, alkylsulfosuccinates, alkylethersulfosuccinates, alkylamidesulfosuccinates, alkylsulfoacetates, acylsarcosinates, acylglutamates, alkylsulfosuccinamates, acyl isethionates and N-alkyl(Cl-C4)-N-acyltaurates, salts of alkyl monoesters and acids polyglycoside-polycarboxylic acids, acyllactylates, salts of D-galactoside-uronic acids, salts of alkyl ether-carboxylic acids, salts of alkyl aryl ether-carboxylic acids, salts of alkyl amidoether-carboxylic acids; and the corresponding unsalified forms of all these compounds;the alkyl and acyl groups of all these compounds (unless otherwise stated) generally having from 6 to 24 carbon atoms and the aryl group generally denoting a phenyl group.;

[0146] Among the anionic surfactants, mention may also be made of fatty acid salts, in particular C8-C24, preferably C12-C20, different from the (poly)carboxylic acids previously described.

[0147] These compounds can be oxyethylenated and then preferably comprise from 1 to 50 ethylene oxide units.

[0148] The salts of C6-C24 alkyl monoesters and polyglycoside-polycarboxylic acids may be chosen from C6-C24 alkyl polyglycoside-citrates, C6-C24 alkyl polyglycoside-tartrates and C6-C24 alkyl polyglycoside-sulfosuccinates.

[0149] When the anionic surfactant(s) are in salt form, they may be chosen from alkali metal salts such as the sodium or potassium salt and preferably the sodium salt, ammonium salts, amine salts and in particular amino alcohol salts or alkaline earth metal salts such as the magnesium salt.

[0150] As examples of amino alcohol salts, mention may be made in particular of mono-, di- and triethanolamine salts, mono-, di- or tri-isopropanolamine salts, 2-amino 2-methyl 1-propanol, 2-amino 2-methyl 1,3-propanediol and tris(hydroxymethyl)amino methane salts.

[0151] Preferably, alkali or alkaline earth metal salts are used, and in particular sodium or magnesium salts.

[0152] The anionic surfactants possibly present may be surfactants soft anionic, i.e. without sulfate function.

[0153] As regards mild anionic surfactants, mention may be made in particular of the following compounds and their salts, as well as their mixtures: polyoxyalkylenated alkyl ether carboxylic acids; polyoxyalkylenated alkylaryl ether carboxylic acids; polyoxyalkylenated alkylamido ether carboxylic acids, in particular those comprising 2 to 50 ethylene oxide groups; alkyl D-galactoside uronic acids; acylsarcosinates, acylglutamates; and alkylpolyglycoside carboxylic esters.

[0154] In particular, it is possible to use polyoxyalkylenated alkyl ether carboxylic acids such as, for example, lauryl ether carboxylic acid (4,5 EO) marketed, for example, under the name AKYPO RLM 45 CA from KAO.

[0155] Among the anionic surfactants mentioned above, use is preferably made of sulfated surfactants such as alkyl sulfates or alkyl ether sulfates, and acylglutamates, C12-C20 fatty acid salts, more preferably alkyl sulfates and C12-C20 fatty acid salts.

[0156] According to a preferred embodiment, the method according to the invention uses one or more surfactants chosen from alkyl sulfates.

[0157] When they are present, the surfactant(s), preferably anionic, used in one or more composition(s) useful in the process according to the invention preferably represent from 0.01 to 15% by weight, more preferably from 0.1 to 10% by weight, better still from 0.3 to 5% by weight, and better still from 0.5 to 3% by weight of the composition(s) containing them. Fatty body

[0158] The method according to the invention can also use one or more fatty substances.

[0159] Preferably, the method according to the invention uses one or more fatty substances.

[0160] For the purposes of the present invention, the term "fatty substance" means an organic compound insoluble in water at ordinary room temperature (20-25°C) and at atmospheric pressure (760 mm Hg, or 1,013.105 Pa), having a solubility in water of less than 5%, preferably less than 1%, and even more preferably less than 0.1%. Fatty substances generally have in their structure a hydrocarbon chain comprising at least 6 carbon atoms. In addition, fatty substances are generally soluble in organic solvents under the same temperature and pressure conditions, such as, for example, chloroform, ethanol, benzene, vaseline oil or decamethylcyclopentasiloxane.

[0161] The fatty substances are also non-(poly)oxyalkylenated and non-(poly)glycerolated. In other words, the fatty substances do not contain in their structure an ethylene (poly)oxide or (poly)glycerol or (poly)propylene glycol unit.

[0162] The fatty substance(s) may be chosen from solid fatty substances and / or liquid fatty substances (also called “oil”), and mixtures thereof.

[0163] By "oil" is meant a "fatty substance" which is liquid, that is to say which is capable of flowing under the action of its own weight at room temperature (25°C), and at atmospheric pressure (760 mm Hg, or 1,013.105 Pa). Preferably the viscosity at a temperature of 25°C and at a shear rate of 1s 1 of the oil is between 10-3 Pa.s and 2 Pa.s. It can be measured with a Thermo Haake RS600 rheometer with cone-plane geometry or an equivalent device.

[0164] For the purposes of the present invention, the term "solid fatty body" means a fatty body that is not liquid at room temperature (20-25°C) and at atmospheric pressure (760 mm Hg, or 1,013.105 Pa), in particular a solid compound or a compound having a viscosity greater than 2 Pa.s at a shear rate of 1 s-1 under the conditions mentioned above.

[0165] Preferably, the fatty substance(s) are chosen from liquid fatty substances.

[0166] Advantageously, the liquid fatty substances are chosen from: - fatty alcohols which are liquid at room temperature with a branched and / or unsaturated carbon chain having from 12 to 26 carbon atoms such as cetanol, octyl dodecanol, linoleic or linolenic alcohol, isostearyl alcohol, oleic alcohol, 2-hexyldecanol, 2-butyloctanol, 2-undecylpentadecanol; - C6-C16 hydrocarbons; - hydrocarbons containing more than 16 carbon atoms; - silicones and their mixtures.

[0167] Preferably, the fatty substance(s) are chosen from hydrocarbons comprising more than 16 carbon atoms.

[0168] Preferably, the method according to the invention uses one or more fatty substances, preferentially chosen from liquid fatty substances, better still from hydrocarbons comprising more than 16 carbon atoms.

[0169] When present, the fatty substance(s), preferably liquid, used in one or more composition(s) useful in the process according to the invention preferably represent from 0.01 to 20% by weight, preferably from 0.1 to 15% by weight, preferentially from 0.2 to 5% by weight of the composition(s) containing them. Associative polymers

[0170] The method according to the present invention can also use one or more associative polymers.

[0171] Preferably, the method according to the invention uses one or more associative polymers.

[0172] It is recalled that “associative polymers” are polymers capable, in a aqueous medium, to reversibly associate with each other or with other molecules.

[0173] Their chemical structure more particularly comprises at least one hydrophilic zone and at least one hydrophobic zone.

[0174] By “hydrophobic group” is meant a radical or polymer with a hydrocarbon chain, saturated or not, linear or branched, comprising at least 10 carbon atoms, preferably from 10 to 30 carbon atoms, in particular from 12 to 30 carbon atoms and more preferably from 18 to 30 carbon atoms.

[0175] Preferably, the hydrocarbon group originates from a monofunctional compound. For example, the hydrophobic group may originate from a fatty alcohol such as stearyl alcohol, dodecyl alcohol, decyl alcohol. It may also designate a hydrocarbon polymer such as, for example, polybutadiene.

[0176] The associative polymer may be anionic, cationic, amphoteric or non-ionic.

[0177] Among the anionic type associative polymers, we can cite:

[0178] - (a) those comprising at least one hydrophilic unit, and at least one ether unit of fatty chain allyl, more particularly those whose hydrophilic unit is constituted by an ethylenically unsaturated anionic monomer, more particularly still by a vinyl carboxylic acid and very particularly by an acrylic acid or a methacrylic acid or mixtures thereof.

[0179] Among these anionic associative polymers, polymers formed from 20 to 60% by weight of acrylic acid and / or methacrylic acid, from 5 to 60% by weight of lower alkyl (meth)acrylates, from 2 to 50% by weight of fatty chain allyl ether, and from 0 to 1% by weight of a crosslinking agent which is a well-known copolymerizable polyethylene unsaturated monomer, such as diallyl phthalate, allyl (meth)acrylate, divinylbenzene, (poly)ethylene glycol dimethacrylate, and methylene-bis-acrylamide are particularly preferred according to the invention.

[0180] Among the latter, particularly preferred are crosslinked terpolymers of methacrylic acid, ethyl acrylate, polyethylene glycol (10 EO) stearyl alcohol ether (Steareth 10), in particular those sold by the company CIBA under the names SALCARE SC80® and SALCARE SC90® which are 30% aqueous emulsions of a crosslinked terpolymer of methacrylic acid, ethyl acrylate and steareth-10-allyl ether (40 / 50 / 10).

[0181] - (b) those comprising i) at least one hydrophilic unit of carboxylic acid type olefinically unsaturated, and ii) at least one hydrophobic unit of the unsaturated carboxylic acid (C10-C30) alkyl ester type.

[0182] Alkyl esters (C10-C30) of unsaturated carboxylic acids useful in the invention include, for example, lauryl acrylate, stearyl acrylate, decyl acrylate, isodecyl acrylate, dodecyl acrylate, and the corresponding methacrylates, lauryl methacrylate, stearyl methacrylate, decyl, isodecyl methacrylate, and dodecyl methacrylate.

[0183] Anionic polymers of this type are for example described and prepared, according to US patents 3,915,921 and 4,509,949.

[0184] Among this type of anionic associative polymers, those consisting of 95 to 60% by weight of acrylic acid (hydrophilic unit), 4 to 40% by weight of C10-C30 alkyl acrylate (hydrophobic unit), and 0 to 6% by weight of crosslinking polymerizable monomer, or those consisting of 98 to 96% by weight of acrylic acid (hydrophilic unit), 1 to 4% by weight of C10-C30 alkyl acrylate (hydrophobic unit), and 0.1 to 0.6% by weight of crosslinking polymerizable monomer such as those described above, will be used more particularly.

[0185] Among the above polymers, the products sold by the company GOODRICH under the trade names PEMULEN TRI®, PEMULEN TR2®, CARBOPOL 1382®, the product sold by the company LUBRIZOL under the trade name CARBOPOL ETD 2020 POLYMER® (INCI name: ACRYLATES / C10-30 ALKYL ACRYLATE CROSSPOLYMER), the product sold by the company SEPC under the name COATEX SX®, and even more preferably CARBOPOL ETD 2020 POLYMER® are particularly preferred according to the present invention.

[0186] Mention may also be made of the acrylic acid / lauryl methacrylate / vinylpyrrolidone terpolymer marketed under the name Acrylidone LM by the ISP Company.

[0187] - (c) maleic anhydride / C30-C38 α-olefin / alkyl maleate terpolymers such as the product (maleic anhydride / C30-C38 a-olefin / isopropyl maleate copolymer) sold under the name PERFORMA V 1608® by the company NEWPHASE TECHNOLOGIES.

[0188] - (d) acrylic terpolymers comprising: (i) about 20 to 70% by weight of an α,[3-monoethylenically unsaturated carboxylic acid [A], ii) about 20 to 80% by weight of a non-surfactant α,[3-monoethylenic] unsaturated monomer different from [A], iii) about 0.5 to 60% by weight of a non-ionic mono-urethane which is the reaction product of a monohydric surfactant with a monoethylenically unsaturated monoisocyanate, such as those described in patent application EP-A-0173109 and more particularly that described in example 3, namely, a methacrylic acid / methyl acrylate / ethoxylated behenyl alcohol dimethyl metaisopropenyl benzyl isocyanate terpolymer (40EO) in 25% aqueous dispersion.

[0189] - (e) copolymers comprising among their monomers a carboxylic acid with saturation a,[3-monoethylenic and an unsaturated carboxylic acid ester a,p-monoethylenic and an oxyalkylenated fatty alcohol.

[0190] Preferably, these compounds also comprise as monomer an ester of carboxylic acid with α,[3-monoethylenic unsaturation and C1-C4 alcohol.

[0191] As an example of this type of compound, mention may be made of ACULYN 22® sold by the company ROHM and HAAS, which is a methacrylic acid / ethyl acrylate / oxyalkylenated stearyl methacrylate terpolymer, as well as ACULYN 88 also sold by the company ROHM and HAAS, or even ACULYN 28® sold by the company ROHM and HAAS, which is a methacrylic acid / ethyl acrylate / oxyalkylenated behenyl methacrylate terpolymer (INCI name Acrylates / Beheneth-25 Methacrylate Copolymer), as well as NOVETHIX L-10 POLYMER® sold by Lubrizol.

[0192] - (f) Amphiphilic polymers comprising at least one unsaturated monomer ethylenic with a sulfonic group, in free or partially or totally neutralized form and comprising at least one hydrophobic part. These polymers can be crosslinked or non-crosslinked. They are preferably crosslinked.

[0193] The ethylenically unsaturated monomers with a sulfonic group are chosen in particular from vinylsulfonic acid, styrenesulfonic acid, (meth)acrylamido(Cl-C22)alkylsulfonic acids, N-(Cl-C22)alkyl(meth)acrylamido-(C1-C22)alkylsulfonic acids such as undecyl-acrylamido-methane-sulfonic acid as well as their partially or totally neutralized forms.

[0194] More preferably, (meth)acrylamido(Cl-C22) alkylsulfonic acids will be used, such as, for example, acrylamido-methanesulfonic acid, acrylamido-ethanesulfonic acid, acrylamido-propanesulfonic acid, 2-acrylamido-2-methylpropanesulfonic acid, methacrylamido-2-methylpropanesulfonic acid, 2-acrylamido-n-butanesulfonic acid, 2-acrylamido-2,4,4-trimethylpentanesulfonic acid, 2-methacrylamido-dodecylsulfonic acid, 2-acrylamido-2,6-dimethyl-3-heptanesulfonic acid, as well as their partially or totally neutralized forms.

[0195] More particularly, 2-acrylamido-2-methylpropanesulfonic acid (AMPS) and its partially or totally neutralized forms will be used.

[0196] The polymers of this family may in particular be chosen from random amphiphilic polymers of AMPS modified by reaction with a C6-C22 n-monoalkylamine or di-n-alkylamine, and such as those described in patent application WO 00 / 31154 (forming an integral part of the content of the description). These polymers may also contain other ethylenically unsaturated hydrophilic monomers chosen for example from (meth)acrylic acids, their alkyl derivatives substituted in [3 or their esters obtained with monoalcohols or mono- or poly-alkylene glycols, (meth)acrylamides, vinylpyrrolidone, maleic anhydride, itaconic acid or maleic acid or mixtures of these compounds.

[0197] The preferred polymers of this family are chosen from amphiphilic copolymers of AMPS and at least one hydrophobic monomer with ethylenic unsaturation.

[0198] These same copolymers may also contain one or more ethylenically unsaturated monomers not comprising a fatty chain such as (meth)acrylic acids, their alkyl derivatives substituted in [3] or their esters obtained with monoalcohols or mono- or polyalkylene glycols, (meth)acrylamides, vinylpyrrolidone, maleic anhydride, itaconic acid or maleic acid or mixtures of these compounds.

[0199] These copolymers are described in particular in patent application EP-A-750899, patent US 5089578 and in the following publications by Yotaro Morishima: - “Self-assembly amphiphilic polyelectrolytes and their nanostructures - Chinese Journal of Polymer Science Vol. 18, No. 40, (2000), 323-336. » ; - « Miscelle formation of random copolymers of sodium 2-(acrylamido)-2-methylpropanesulfonate and a non-ionic surfactant macromonomer in water as studied by fluorescence and dynamic light scattering - Macromolecules, Vol. 33, N° 10 (2000), 3694-3704 » ; - « Solution properties of miscelle networks formed by non-ionic moieties covalently bound to an polyelectrolyte : sait effects on rheological behavior - Langmuir,, Vol. 16, N°12, (2000) 5324-5332» ; - « Stimuli responsive amphiphilic copolymers of sodium 2-(acrylamido)-2-methylpropanesulfonate and associative macromonomers - Polym. Preprint, Div. Polym. Chem., 40(2), (1999), 220-221».

[0200] Parmi ces polymères, on peut citer : - crosslinked or non-crosslinked copolymers, neutralized or not, comprising from 15 to 60% by weight of AMPS units and from 40 to 85% by weight of (C8-C16)alkyl(meth)acrylamide units or (C8-C16)alkyl(meth)acrylate units relative to the polymer, such as those described in application EP-A750 899; - terpolymers comprising from 10 to 90 mol% of acrylamide units, from 0.1 to 10 mol% of AMPS units and from 5 to 80 mol% of n-(C6-C18)alkylacrylamide units, such as those described in patent US-5089578.

[0201] Mention may also be made of copolymers of fully neutralized AMPS and dodecyl methacrylate as well as non-crosslinked and crosslinked copolymers of AMPS and n-dodecylmethacrylamide, such as those described in the Morishima articles cited above.

[0202] Among the anionic associative polymers according to the invention, the following are preferred: polymers comprising i) at least one hydrophilic unit of olefinic unsaturated carboxylic acid type, and ii) at least one hydrophobic unit of alkyl ester (C10-C30) of unsaturated carboxylic acid type (family b)), and copolymers comprising among their monomers an α,[3-monoethylenically unsaturated carboxylic acid and an ester of α,[3-monoethylenically unsaturated carboxylic acid and an oxyalkylenated fatty alcohol (family e)).

[0203] Among the cationic associative polymers we can cite:

[0204] (a) cationic associative polyurethanes;

[0205] (b) the compound marketed by the company NOVEON under the name AQUA CC and which corresponds to the INCI name POLYACRYLATE-1 CROSSPOLYMER.

[0206] POLYACRYLATE-1 CROSSPOLYMER is the product of the polymerization of a mixture of monomers comprising: a di(C1-C4 alkyl)amino(C1-C6 alkyl)methacrylate, one or more C1-C30 alkyl esters of (meth)acrylic acid, a polyethoxylated C10-C30 alkyl methacrylate (20-25 moles of ethylene oxide unit), a polyethylene glycol / polypropylene glycol 30 / 5 allyl ether, a hydroxy(C2-C6)alkyl methacrylate, and an ethylene glycol dimethacrylate.

[0207] (c) quaternized (poly)hydroxyethylcelluloses modified by groups comprising at least one fatty chain, such as alkyl, arylalkyl, al-kylaryl groups comprising at least 8 carbon atoms, or mixtures thereof. The alkyl radicals carried by the above quaternized celluloses or hydroxyethylcelluloses preferably comprise from 8 to 30 carbon atoms. The aryl radicals preferably denote phenyl, benzyl, naphthyl or anthryl groups. Examples of quaternized alkylhydroxyethylcelluloses with C8-C30 fatty chains include the products QUATRISOFT LM 200®, QUATRISOFT LM-X 529-18-A®, QUATRISOFT LM-X 529-18-B® (C12 alkyl) and QUATRISOFT LM-X 529-8® (C18 alkyl) sold by AQUALON, the products CRODACEL QM®, CRODACEL QL® (C12 alkyl) and CRODACEL QS® (C18 alkyl) sold by CRODA and the product SOFTCAT SL 100® sold by AQUALON.

[0208] (d) cationic polyvinyllactam polymers.

[0209] Such polymers are for example described in patent application WO-00 / 68282.

[0210] As cationic poly(vinyllactam) polymers according to the invention, vinylpyrrolidone / dimethylaminopropylmethacrylamide / terpolymers are used in particular. dodecyldimethylmethacrylamidopropylammonium tosylate, vinylpyrrolidone / dimethylaminopropylmethacrylamide / cocoyldimethylmethacrylamidopropylammonium tosylate terpolymers, vinylpyrrolidone / dimethylaminopropylmethacrylamide / tosylate terpolymers or lauryldimethylmethacrylamidopropylammonium chloride.

[0211] The amphoteric associative polymers are preferably chosen from those comprising at least one non-cyclic cationic unit. More particularly still, those prepared from or comprising 1 to 20 mol% of monomer comprising a fatty chain, and preferably 1.5 to 15 mol% and more particularly still 1.5 to 6 mol%, relative to the total number of moles of monomers, are preferred.

[0212] Amphoteric associative polymers which can be used in the invention are for example described and prepared in patent application WO 9844012.

[0213] Among the amphoteric associative polymers, acrylic acid / (meth)acrylamidopropyl trimethyl ammonium chloride / stearyl methacrylate terpolymers are preferred.

[0214] The non-ionic type associative polymers which can be used according to the invention are preferably chosen from:

[0215] (a) copolymers of vinyl pyrrolidone and hydrophobic chain monomers fat, of which we can cite as examples: - ANTARON V216® or GANEX V216® products (vinylpyrrolidone / hexadecene copolymer) sold by the company LS.P. - ANTARON V220® or GANEX V220® products (vinylpyrrolidone / eicosene copolymer) sold by the company LS.P.

[0216] (b) copolymers of C1-C6 alkyl methacrylates or acrylates and amphiphilic monomers comprising at least one fatty chain such as, for example, the methyl acrylate / oxyethylenated stearyl acrylate copolymer sold by the company GOLDSCHMIDT under the name ANTIL 208®. Or the copolymer with the INCI name “acrylates / beheneth-25 methacrylate copolymer” such as the product Novethix L-10 polymer from Lubrizol.

[0217] (c) copolymers of hydrophilic methacrylates or acrylates and monomers hydrophobic comprising at least one fatty chain such as for example the polyethylene glycol methacrylate / lauryl methacrylate copolymer.

[0218] (d) polyether polyurethanes comprising in their chain, both sequences hydrophilic, most often polyoxyethylenated in nature, and hydrophobic sequences which can be aliphatic chains alone and / or cycloaliphatic and / or aromatic chains.

[0219] (e) polymers with an aminoplast ether skeleton having at least one chain fatty, such as the PURE THIX® compounds offered by the company SUD-CHEMIE.

[0220] (f) celluloses or their derivatives, modified by groups comprising at least less than one fatty chain such as alkyl, arylalkyl, alkylaryl groups or their mixtures where the alkyl groups are C8- and in particular: * non-ionic alkylhydroxyethylcelluloses such as NATROSOL PLUS GRADE 330 CS and POLYSURF 67 (Cl6 alkyl) products sold by AQUALON * non-ionic nonoxynylhydroxyethylcelluloses such as the product AMERCELL HM-1500 sold by the company AMERCHOL; * non-ionic alkylcelluloses such as the product BERMOCOLL EHM 100 sold by the company BEROL NOBEL;

[0221] (g) associative guar derivatives such as hydroxypropyl guars modified with a fatty chain such as the product ESAFLOR HM 22 (modified by a C22 alkyl chain) sold by the company LAMBERTI; the product MIRACARE XC 95-3 (modified by a Cl4 alkyl chain) and the product RE 205-146 (modified by a C20 alkyl chain) sold by RHODIA CHIMIE.

[0222] Preferably, the polyurethane polyethers comprise at least two lipophilic hydrocarbon chains, having from 6 to 30 carbon atoms, separated by a hydrophilic sequence, the hydrocarbon chains possibly being pendant chains or chains at the end of a hydrophilic sequence. In particular, it is possible for one or more pendant chains to be provided. In addition, the polymer may comprise a hydrocarbon chain at one end or at both ends of a hydrophilic sequence.

[0223] Polyether polyurethanes can be multi-block, in particular in triblock form. The hydrophobic blocks can be at each end of the chain (for example: triblock copolymer with hydrophilic central block) or distributed both at the ends and in the chain (multi-block copolymer for example). These same polymers can also be in graft or star form.

[0224] Non-ionic fatty chain polyurethane polyethers may be triblock copolymers whose hydrophilic sequence is a polyoxyethylenated chain comprising from 50 to 1000 oxyethylenated groups. Non-ionic polyurethane polyethers comprise a urethane bond between the hydrophilic sequences, hence the origin of the name.

[0225] By extension, non-ionic fatty chain polyurethane polyethers also include those whose hydrophilic sequences are linked to the lipophilic sequences by other chemical bonds.

[0226] As examples of non-ionic fatty chain polyurethane polyethers which can be used in the invention, it is also possible to use Rhéolate 205® with urea function sold by the company RHEOX or even Rhéolates® 208, 204 or 212, as well as Acrysol RM 184®.

[0227] Mention may also be made of the ELFACOS T210® product with a C12-14 alkyl chain and the ELFACOS T212® product with a C18 alkyl chain from AKZO.

[0228] ROHM & HAAS's DW 1206B® product with a C20 alkyl chain and a urethane bond, offered at 20% dry matter in water, can also be used.

[0229] It is also possible to use solutions or dispersions of these polymers, in particular in water or in a hydroalcoholic medium. By way of example, such polymers include RHEOLATE® 255, RHEOLATE® 278 and RHEOLATE® 244 sold by the company RHEOX. It is also possible to use the product DW 1206F and DW 1206J offered by the company ROHM & HAAS.

[0230] The polyether polyurethanes which can be used according to the invention are in particular those described in the article by G. Fonnum, J. Bakke and Fk. Hansen - Colloid Polym. Sci 271, 380.389 (1993).

[0231] More particularly still, it is preferred to use a polyether polyurethane capable of being obtained by polycondensation of at least three compounds comprising (i) at least one polyethylene glycol comprising from 150 to 180 moles of ethylene oxide, (ii) stearyl alcohol or decyl alcohol and (iii) at least one diisocyanate.

[0232] Such polyether polyurethanes are sold in particular by the company ROHM & HAAS under the names ACULYN 46® and ACULYN 44® [ACULYN 46® is a polycondensate of polyethylene glycol with 150 or 180 moles of ethylene oxide, stearyl alcohol and methylene bis(4-cyclohexylisocyanate) (SMDI), at 15% by weight in a matrix of maltodextrin (4%) and water (81%); ACULYN 44® is a polycondensate of polyethylene glycol with 150 or 180 moles of ethylene oxide, decyl alcohol and methylene bis(4-cyclohexylisocyanate) (SMDI), at 35% by weight in a mixture of propylene glycol (39%) and water (26%)].

[0233] Preferably, the associative polymer(s) are chosen from anionic associative polymers.

[0234] Preferably, the associative polymer(s) are chosen from homopolymers or copolymers of acrylic or methacrylic acid.

[0235] More preferably, the associative polymer(s) are chosen from polymers comprising i) at least one hydrophilic unit of olefinic unsaturated carboxylic acid type, and ii) at least one hydrophobic unit of (C10-C30) alkyl ester of unsaturated carboxylic acid type, the copolymers comprising among their monomers an α,[3-monoethylenically unsaturated carboxylic acid and an ester of an α,[3-monoethylenically unsaturated carboxylic acid and an oxyalkylenated fatty alcohol, and mixtures thereof.

[0236] Preferably, the method according to the invention uses one or more associative polymer(s), preferentially chosen from anionic associative polymers, preferably from homopolymers or copolymers of acrylic acid. or methacrylic.

[0237] When they are present, the associative polymer(s) used in one or more composition(s) useful in the process according to the invention preferably represent(s) from 0.05 to 10% by weight, better still from 0.1 to 8% by weight, even better still from 0.2 to 5% by weight of the composition(s) containing them. Non-associative polysaccharides

[0238] The method according to the present invention can also use one or more non-associative polysaccharides, which are therefore different from the associative polymers above.

[0239] Preferably, the method according to the invention uses one or more non-associative polysaccharides.

[0240] In the present invention, the term "polysaccharide" means a polymer consisting of sugar units. The term "sugar unit" means an oxygenated hydrocarbon compound which has several alcohol functions, with or without an aldehyde or ketone function, and which comprises at least 4 carbon atoms. The sugar units may optionally be modified by substitution, and / or by oxidation and / or by dehydration.

[0241] The sugar units which may be included in the composition of the polysaccharides of the invention are preferably derived from the following sugars: glucose; galactose; arabinose; rhamnose; mannose; xylose; fucose; anhydrogalactose; galacturonic acid; glucuronic acid; mannuronic acid; galactose sulfate; anhydrogalactose sulfate and fructose.

[0242] In particular, non-associative polysaccharides may include the following polymers, alone or as a mixture: (a) exudates from trees or shrubs including: - gum arabic (branched polymer of galactose, arabinose, rhamnose and glucuronic acid); - gum ghatti (polymer derived from arabinose, galactose, mannose, xylose and glucuronic acid); - karaya gum (polymer from galacturonic acid, galactose, rhamnose and glucuronic acid); - gum tragacanth (or tragacanth) (polymer of galacturonic acid, galactose, fucose, xylose and arabinose); b) gums derived from algae including: - agar (polymer made from galactose and anhydrogalactose); - alginates (polymers of mannuronic acid and glucuronic acid); - carrageenans and furcellerans (polymers of galactose sulfate and anhydrogalactose sulfate); (c) gums from seeds or tubers of which: - guar gum (polymer of mannose and galactose); - carob gum (polymer of mannose and galactose); - fenugreek gum (polymer of mannose and galactose); - tamarind gum (polymer of galactose, xylose and glucose); - konjac gum (polymer of glucose and mannose); (d) microbial gums including: - xanthan gum (polymer of glucose, mannose acetate, mannose / pyruvic acid and glucuronic acid); - gellan gum (polymer of partially acylated glucose, rhamnose and glucuronic acid); - scleroglucan gum (glucose polymer); (e) polymers extracted from plants including: - celluloses (glucose polymers); - starches (glucose polymers) and - inulin.

[0243] These polymers can be modified physically or chemically. As a physical treatment, mention may be made in particular of a heat treatment. As chemical treatments, mention may be made of esterification, etherification, amidation and oxidation reactions. These treatments make it possible to produce polymers which may be, in particular, non-ionic, anionic or amphoteric.

[0244] In particular, guar gums, carob gums, starches and celluloses can be modified / treated.

[0245] The guar gums that can be used according to the invention can be modified by C1-C6 (poly)hydroxyalkyl groups. Among the C1-C6 (poly)hydroxyalkyl groups, mention may be made, by way of example, of the hydroxymethyl, hydroxyethyl, hydroxypropyl and hydroxybutyl groups. These guar gums are well known in the state of the art and can, for example, be prepared by reacting corresponding alkene oxides such as, for example, propylene oxides with guar gum so as to obtain a guar gum modified by hydroxypropyl groups. The hydroxyalkylation rate preferably varies from 0.4 to 1.2 and corresponds to the number of alkylene oxide molecules consumed by the number of free hydroxyl functions present on the guar gum.

[0246] Such guar gums, optionally modified by hydroxyalkyl groups, are for example sold under the trade names JAGUAR HP8, JAGUAR HP60 and JAGUAR HP120 by the company RHODIA CHIMIE.

[0247] The starches that can be used in the present invention may have cereals or tubers as botanical origin. Thus, the starches are, for example, chosen from corn, rice, oat, cassava, barley, potato, wheat, sorghum, peas, tapioca. Hydrolysates of the starches mentioned above can also be used. The starch is preferably derived from potatoes.

[0248] Preferably, starch phosphates will be used, in particular distarch phosphates or compounds rich in distarch phosphate such as the product proposed under the references PREJEL VA-70-T AGGL (gelatinized hydroxypropyl cassava distarch phosphate) or PREJEL TK1 (gelatinized cassava distarch phosphate) or PREJEL 200 (gelatinized acetylated cassava distarch phosphate) by the company AVEBE or STRUCTURE ZEA from NATIONAL STARCH (gelatinized corn distarch phosphate).

[0249] According to the invention, amphoteric starches can also be used, these amphoteric starches comprise one or more anionic groups and one or more cationic groups. The anionic and cationic groups can be linked to the same reactive site of the starch molecule or to different reactive sites; preferably they are linked to the same reactive site. The anionic groups can be of the carboxylic, phosphate or sulfate type and preferably carboxylic. The cationic groups can be of the primary, secondary, tertiary or quaternary amine type.

[0250] The polysaccharides that can be used according to the invention can be cellulose polymers.

[0251] According to the invention, the term “cellulosic” polymer means any polysaccharide compound having in its structure chains of glucose residues joined by [3-1,4] bonds; in addition to unsubstituted celluloses, cellulose derivatives can be anionic, cationic, amphoteric or non-ionic.

[0252] Cellulosic polymers are also called celluloses.

[0253] Thus, the cellulose polymers which can be used according to the invention can be chosen from unsubstituted celluloses including in a microcrystalline form and cellulose ethers.

[0254] Among these cellulose polymers, we distinguish cellulose ethers, cellulose esters and cellulose ether esters.

[0255] Among the cellulose esters, there are inorganic cellulose esters (nitrates, sulfates or phosphates of cellulose, etc.), organic cellulose esters (monoacetates, triacetates, amidopropionates, acetatebutyrates, acetatepropionates or acetatetrimellitates of cellulose) and mixed organic / inorganic cellulose esters such as cellulose acetatebutyratesulfates and acetatepropionatesulfates. Among the cellulose ether esters, there may be mentioned hydroxypropylmethylcellulose phthalates and ethylcellulose sulfates.

[0256] Among the cellulose ethers, mention may be made of (Cl-C4)alkylcelluloses such as methylcelluloses and ethylcelluloses (for example Ethocel standard 100 Premium from DOW CHEMICAL); (poly)hydroxy(Cl-C4)alkylcelluloses such as hydroxymethylcelluloses, hydroxyethylcelluloses (e.g. Natrosol 250 HHR offered by ASHLAND) and hydroxypropylcelluloses (e.g. Klucel EF from AQUALON); mixed celluloses (poly)hydroxy(Cl-C4)alkyl-(Cl-C4)alkylcelluloses such as hydroxypropylmethylcelluloses (e.g. Methocel E4M from DOW CHEMICAL), hydroxyethylmethylcelluloses, hydroxyethylethylcelluloses (e.g. Bermocoll E 481 FQ from AKZO NOBEL) and hydroxybutylmethylcelluloses.

[0257] Among the anionic cellulose ethers, mention may be made of (poly)carboxy(Cl-C4)alkylcelluloses and their salts. By way of example, mention may be made of carboxymethylcelluloses, carboxymethylmethylcelluloses (for example Blanose 7M from the company AQUALON) and carboxymethylhydroxyethylcelluloses and their sodium salts.

[0258] Among the cationic cellulose ethers, mention may be made of cationic cellulose derivatives such as cellulose copolymers or cellulose derivatives grafted with a water-soluble quaternary ammonium monomer, and described in particular in US patent 4,131,576, such as (poly)hydroxy(Cl-C4)alkyl celluloses, such as hydroxymethyl-, hydroxyethyl- or hydroxypropyl celluloses grafted in particular with a methacryloylethyl trimethylammonium salt, methacrylmidopropyl trimethylammonium salt, dimethyldiallylammonium salt. The marketed products meeting this definition are more particularly the products sold under the name "Celquat® L 200" and "Celquat® H 100" by the National Starch Company.

[0259] Preferably, the non-associative polysaccharide(s) are chosen from, alone or as a mixture, celluloses, guar gums, starches, preferentially from celluloses.

[0260] Better still, the non-associative polysaccharides are chosen from, alone or as a mixture, cellulose ethers, cellulose esters, cellulose ether esters and guar gums, and preferably from cellulose ethers.

[0261] In a particularly preferred manner, the non-associative polysaccharide(s) are chosen from (Cl-C4)alkylcelluloses such as methylcelluloses and ethylcelluloses; (poly)hydroxy(Cl-C4)alkylcelluloses such as hydroxymethylcelluloses, hydroxyethylcelluloses and hydroxypropylcelluloses; mixed celluloses (poly)hydroxy(Cl-C4)alkyl-(Cl-C4)alkylcelluloses such as hydroxypropylmethylcelluloses, hydroxyethylmethylcelluloses, hydroxyethylethylcelluloses and hydroxybutylmethylcelluloses.

[0262] Preferably, the method according to the invention uses one or more non-associative polysaccharides, preferentially chosen from celluloses, guar gums, starches, and mixtures thereof.

[0263] When they are present, the non-associative polysaccharide(s) used in one or more composition(s) useful in the process according to the invention preferably represent(s) from 0.05 to 10% by weight, better still from 0.1 to 8% by weight, even better still from 0.2 to 5% by weight of the composition(s) containing them. Additives

[0264] The composition(s) of the lightening process according to the invention may also comprise one or more additives, among which may be mentioned mineral thickening agents, anti-dandruff agents, anti-seborrhoeic agents, anti-hair loss and / or regrowth agents, vitamins and provitamins including panthenol, sunscreens, mineral or organic pigments, plasticizing agents, solubilizing agents, opacifying or pearlescent agents, antioxidant agents, sequestering agents, perfumes, preservatives.

[0265] Of course, those skilled in the art will take care to choose this or these possible complementary compounds in such a way that the advantageous properties intrinsically attached to the composition(s) of the process according to the invention are not, or not substantially, altered by the addition(s) envisaged.

[0266] The above additives may generally be present in an amount of between 0 and 20% by weight for each of them, relative to the total weight of the composition(s) containing them. 2 Process

[0267] According to the lightening process of the invention, the keratin fibers can be treated with the compounds described above in one or more application steps.

[0268] According to the process of the invention, the keratin fibers can be treated with one or more compositions which contain, together or separately, the compounds described above.

[0269] According to a preferred embodiment, compounds (b) and (c), i.e. the osmolyte(s) (b) and the hydroxylated polycarboxylic acid(s), one of their salts or their mixtures (c) are applied together to the keratin fibers. Preferably, compounds (b) and (c) are contained in the same composition.

[0270] According to a preferred embodiment, the keratin fibers are treated in one application step, all compounds (a), (b) and (c) being applied together to the fibers.

[0271] According to this embodiment, the method comprises a step of applying to the keratin fibers a composition (C) comprising the compounds (a), (b), (c), and optionally (d) as defined previously.

[0272] The method according to the invention may comprise, before the step of applying the composition (C), a step of mixing a composition (Cl) comprising the compounds (a), (b) and (c), and an oxidizing composition (O) comprising the compound(s) (d).

[0273] This mixing step is preferably carried out at the time of use, just before applying the composition (C) resulting from the mixture to the hair.

[0274] Preferably, the compositions (Cl) and (O) are mixed in a weight ratio (Cl) / (O) ranging from 0.1 to 2, preferably from 0.3 to 1.5, better still from 0.5 to 1.

[0275] Alternatively, the method according to the invention may comprise, before the step of applying the composition (C), a step of mixing the compounds (b) and (c) with a composition (C2) comprising the compound(s) (a), and optionally with an oxidizing composition (O) comprising the compound(s) (d).

[0276] Preferably, composition (C) can be applied to dry or wet keratin fibers.

[0277] It is left in place on the fibers for a duration generally ranging from 1 minute to 1 hour, preferably from 5 minutes to 55 minutes.

[0278] The temperature during the lightening process typically ranges from room temperature (between 15 and 25°C) to 80°C, preferably from room temperature to 60°C.

[0279] At the end of the treatment, the keratin fibers are optionally rinsed with water, optionally undergo washing with shampoo followed by rinsing with water, before being dried or left to dry.

[0280] According to another preferred embodiment, the keratin fibers are treated in several application steps, the process using the compounds (a), (b), (c) and optionally (d) described previously from at least two compositions applied separately to the keratin fibers.

[0281] According to this embodiment, the method of the invention may comprise: (i) the application to the keratin fibers of a composition (C3) comprising the compounds (a), and optionally (d), and (ii) the application to the keratin fibers of a composition (C4) comprising compounds (b) and (c).

[0282] According to this embodiment, step (ii) can be implemented before or after step (i). Preferably, step (ii) is implemented after step (i).

[0283] Step (ii) of applying the composition (C4) can be repeated several times, with or without rinsing between applications.

[0284] Preferably, the method comprises, before step (i), a step of mixing a composition (C2) comprising the compound(s) (a) with an oxidizing composition (O) comprising the compound(s) (d).

[0285] Preferably, compositions (C3) and (C4) can be applied to dry or wet keratin fibers.

[0286] The composition (C3) is left in place on the fibers for a duration ranging, in generally 1 minute to 1 hour, preferably 5 minutes to 55 minutes.

[0287] The composition (C4) is left in place on the fibers for a duration generally ranging from 1 minute to 30 minutes, better still from 5 to 15 minutes.

[0288] Composition (C4) can be applied before or after composition (C3).

[0289] Preferably, the method comprises a step of rinsing the keratin fibers. between steps (i) and (ii).

[0290] The temperature during the lightening process typically ranges from room temperature (between 15 and 25°C) to 80°C, preferably from room temperature to 60°C.

[0291] At the end of the treatment, the keratin fibers are optionally rinsed with water, optionally undergo washing with shampoo followed by rinsing with water, before being dried or left to dry. 3 Compositions

[0292] Another subject of the invention is a composition (C) comprising the compounds (a), (b), (c), and optionally (d) as defined previously.

[0293] As indicated previously, according to a first preferred embodiment of the invention, the method can implement the compounds (a), (b), (c) and optionally (d) described previously in a single step of applying a composition (C) to the keratin fibers.

[0294] Preferably, the composition (C) comprises one or more additional oxidizing agent(s) (d), different from the peroxygenated salts, the composition (C) then being a ready-to-use composition.

[0295] Preferably, the composition (C) is aqueous. Preferably, the pH of the composition (C), when it is aqueous, ranges from 8 to 13, preferably from 9 to 12.

[0296] Preferably, composition (C) is derived from the mixture of a composition (Cl) comprising (a), (b) and (c) and an oxidizing composition (O) which comprises a chemical oxidizing agent (d) different from the peroxygenated salts (a).

[0297] Preferably, the composition (Cl) comprises one or more alkaline agent(s) as described previously.

[0298] Preferably, the composition (Cl) comprises one or more surfactants as described previously.

[0299] Preferably, the composition (Cl) comprises one or more fatty substances as described previously.

[0300] Preferably, the composition (Cl) comprises one or more thickening polymer(s) as described previously.

[0301] The composition (Cl) may optionally comprise one or more amino acid type compound(s) described previously.

[0302] The composition (Cl) may optionally comprise one or more colorant(s) direct(s) described previously.

[0303] Preferably, the composition (Cl) is anhydrous. By anhydrous composition is meant a composition which does not comprise, or comprises little water, in particular less than 0.5% water, better still less than 0.1% water, even better still less than 0.05%, relative to the total weight of the composition. In particular, the composition (Cl) does not comprise any water added during its preparation, any water which may be present being provided by the raw materials used during its preparation.

[0304] Preferably, the composition (Cl) is a powdery composition.

[0305] According to a particular embodiment, the composition (Cl) may be derived from the mixture of compounds (b) and (c) with a composition (C2) comprising the other compounds of composition (Cl) described above.

[0306] According to this embodiment, the composition (C2) is preferably anhydrous, and is preferably a powdery composition.

[0307] The oxidizing composition (O) which comprises a chemical oxidizing agent (d) other than the peroxygenated salts (a) is preferably an aqueous composition. In particular, it comprises more than 10% by weight of water, preferably more than 30% by weight of water, and even more advantageously more than 50% by weight of water relative to the total weight of the oxidizing composition (O). Preferably the oxidizing composition (O) comprises water in a content ranging from 10% to 95% by weight, preferably from 30% to 90% by weight, better still from 50 to 80% by weight relative to the total weight of the oxidizing composition (O).

[0308] The pH of the oxidizing composition (O), when it is aqueous, is preferably less than 7, preferably between 1 and 5, preferentially between 1.5 and 4.5. This pH can be adjusted to the desired value by the use of one or more acidifying agents, which can in particular be chosen from those described above.

[0309] As indicated previously, according to a second preferred embodiment of the invention, the method can use the compounds (a), (b), (c) and optionally (d) described previously from two compositions (C3) and (C4) applied separately to the keratin fibers.

[0310] According to this embodiment, the composition (C3) comprises one or more compound(s) (a) and optionally one or more additional oxidizing agent(s) (d), different from the peroxygenated salts.

[0311] Preferably, the composition (C3) comprises one or more additional oxidizing agent(s) (d), different from the peroxygenated salts, the composition (C3) then being a ready-to-use composition.

[0312] Preferably, the composition (C3) is aqueous. Preferably, the pH of the composition (C3), when it is aqueous, ranges from 8 to 13, preferably from 9 to 12.

[0313] Preferably, composition (C3) is derived from the mixture of a composition (C2) comprising the compound(s) (a) and an oxidizing composition (O) as defined above.

[0314] Preferably, the composition (C2) comprises one or more alkaline agent(s) as described previously.

[0315] Preferably, the composition (C2) comprises one or more surfactants as described previously.

[0316] Preferably, the composition (C2) comprises one or more fatty substances as described previously.

[0317] Preferably, the composition (C2) comprises one or more thickening polymer(s) as described previously.

[0318] Composition (C2) may optionally comprise one or more amino acid type compound(s) described previously.

[0319] Composition (C2) may optionally comprise one or more direct dye(s) described previously.

[0320] Preferably, composition (C2) is anhydrous in the sense defined above.

[0321] Composition (C4) comprises compounds (b) and (c) as described previously.

[0322] Preferably, the composition (C4) comprises one or more surfactants as described previously.

[0323] Preferably, the composition (C4) comprises one or more fatty substances as described previously.

[0324] Preferably, the composition (C4) comprises one or more thickening polymer(s) as described previously, and in particular one or more polysaccharide(s), preferably one or more cationic polysaccharide(s).

[0325] Composition (C4) may optionally comprise one or more amino acid type compound(s) described previously.

[0326] Composition (C4) may optionally comprise one or more direct dye(s) described previously.

[0327] Preferably, composition (C4) is aqueous.

[0328] The invention also relates to the use of a composition comprising compounds (a), (b), (c), and optionally (d) as defined above, for lightening keratin fibers, and in particular hair. 4 Multi-compartment kit / device

[0329] Another subject of the invention is a device with at least two compartments, for lightening keratin fibers, comprising at least a first compartment containing a composition (Cl) comprising compounds (a), (b) and (c) as described previously, and at least a second compartment containing an oxidizing composition (O) comprising one or more compounds (d) such that described previously.

[0330] Another subject of the invention is a device with at least two compartments, for lightening keratin fibers, comprising at least a first compartment containing a composition (C2) comprising the compound(s) (a) as described above, at least a second compartment containing a composition (C4) comprising the compounds (b) and (c) as described above, and optionally at least a third compartment containing an oxidizing composition (O) comprising one or more compounds (d) as described above.

[0331] The compositions of the device according to the invention are packaged in separate compartments, accompanied, optionally, by appropriate application means, identical or different, such as brushes, brushes or sponges.

[0332] The device mentioned above can also be equipped with a means for delivering the desired mixture to the hair, for example such as the devices described in patent FR 2586913.

[0333] The following examples serve to illustrate the invention without, however, being limiting in nature. Examples

[0334] In the following examples, all quantities are indicated as a percentage by mass of active ingredient (AI) relative to the total weight of the composition (unless otherwise stated).

[0335] Compositions

[0336] Compositions A, A1 and A2 were prepared from the compounds whose contents are indicated in the table below:

[0337] [Tables 1] A Al A2 POTASSIUM PERSULFATE 41.6 41.6 41.6 AMMONIUM PERSULFATE 11.5 11.5 11.5 SODIUM SILICATE 28 28 16.7 SODIUM METASILICATE - - 5.6 HYDROXYETHYLCELLULOSE 0.7 0.7 0.7 ACRYLATES / C10-30 ALKYL ACRYLATE CROSSPOLYMER 0.7 0.7 0.7 SODIUM LAURYL SULFATE 1.0 1.0 1.0 MINERAL OIL / PARAFFINUM LIQUIDUM 2.0 0.7 2.0 ULTRAMARINES 0.6 0.6 0.5 BETAINE (trimethylglycine) - 2.5 2.5 CITRIC ACID - 2.5 2.5 Sequestrant(s), load(s) QS 100 QS 100 QS 100

[0338] We then added:

[0339] - 0.1g of trimethylglycine (glycine betaine) and 0.1g of citric acid at 4g of com position A to obtain a composition A', and

[0340] - 0.1g of trimethylglycine (glycine betaine) to 4g of composition A to obtain a composition A”.

[0341] At the time of use, compositions A' and A” were respectively mixed with an oxidizing composition O comprising 9% hydrogen peroxide according to the weight ratio 1+1.5.

[0342] Each of the mixtures A'+O and A' '+O was then applied to a strand of natural brown hair (tone height 4) at a rate of 10g of mixture per 1g of strand of hair.

[0343] After a setting time of 50 min at 33°C under an occlusive system of the aluminum papillote type, the strands were rinsed, then washed and dried at 60°C in an oven.

[0344] Calorimetric evaluation

[0345] Hair lightening was assessed in the L*a*b* system, with a KONICA MINOLTA CM-3600A spectro-colorimeter (illuminant D65, angle 10°, specular component included) in the CIELab system.

[0346] In this system, L* represents the color intensity, a* represents the red / green and b* the yellow / blue axis. The higher the L* value, the lighter the color.

[0347] Hair condition assessment

[0348] Hair integrity was assessed based on several parameters:

[0349] - tensile strength: the strength of the hair which can be measured by the tensile test. traction. This measurement of determining the mechanical properties of the hair in traction is carried out using a commercial tool, the MTT600 (mini Tensile Tester) from the company Dia Stron. The elastic modulus and breaking strength of the hair are measured: the higher their values, the more resistant the hair is;

[0350] - the quantitative evaluation of cysteic acid and free proteins on the surface of the hair: these compounds are released during hair oxidation; the higher the content of cysteic acid and free proteins, the more damaged the hair is.

[0351] The dosage of cysteic acid present in the hair is carried out using a Hitachi L8900 amino acid autoanalyzer, 20 mg of finely cut hair are transferred into a culture tube (DURAN). 2.5 mL of 9N hydrochloric acid are added to the tube under magnetic stirring and under nitrogen for 1 min at 2 bars.

[0352] The solution is heated in the tube in an oil bath at 110°C for 16 hours. The pH is adjusted between 1.6 and 1.8, and diluted with ultrapure water to 50 mL. The solution is then filtered and analyzed using the autoanalyzer.

[0353] The quantitative analysis of labile proteins (i.e. free proteins) is carried out with the same apparatus as for the determination of cysteic acid.

[0354] 20mg of finely cut hair is transferred into a 1.5ml Eppendorf tube. 400pl of 0.2M Tris (hydroxymethyl) aminomethane “TRIZMA base” and 400pl of 0.2M 2-mercaptoethanol are added to the tube and stirred in a thermo-mixer set at 37°C for 16 hours at 700rev / min. After 16h of extraction, the residual contents are transferred into a DURAN tube using a liquid dispenser and concentrated under compressed air for 4 hours until complete evaporation of the solvent.

[0355] 1ml of 9N hydrochloric acid is added to each tube and then heated for 16 hours at 110°C. The hydrolyzed solution is concentrated under compressed air for 12 hours until complete evaporation, 1ml of pH2 buffer is added, then vortexed, then filtered and analyzed on a Hitachi autoanalyzer. Results

[0356] [Tables2] L*(D65) Modulus of elasticity (MPa) Tensile strength (MPa) Cysteic acid (g / 100g amino acids) Labile proteins (g / 100g hair) Hair treated with A' + 0 69.9 737 114 10.7 14.5 Hair treated with A” + 0 70.7 607 90 11.8 18.1

[0357] The results show that a composition according to the invention makes it possible, with equivalent lightening performances, to maintain better integrity of the hair (significant increase in the modulus of elasticity and resistance to breakage and lower quantities of cysteic acid and labile proteins) compared to the comparative composition.

Claims

Claims

1. Process for lightening keratin fibres, preferably human, in particular hair, in which said fibres are treated, in one or more steps, with one or more compositions containing, together or separately: (a) one or more peroxygenated salts; (b) one or more osmolytes; (c) one or more hydroxylated polycarboxylic acids, one of their salts or their mixtures, and (d) optionally, one or more additional oxidising agent(s), other than the peroxygenated salts.

2. Process according to the preceding claim, in which the peroxygenated salt(s) (a) are chosen from persulfates, perborates, percarbonates of alkali metals, alkaline earth metals, or ammonium, magnesium peroxide and mixtures thereof, preferably from alkali metal persulfates, alkaline earth metal persulfates, ammonium persulfates, and mixtures thereof; more preferably from (bis)tetrabutylammonium persulfate, barium persulfate, magnesium persulfate, calcium persulfate, sodium persulfate, potassium persulfate, ammonium persulfate, and mixtures thereof; even more preferably from sodium persulfate, potassium persulfate, ammonium persulfate, and mixtures thereof; even better among potassium persulfate, ammonium persulfate, and their mixtures.

3. Process according to any one of the preceding claims, in which the osmolyte(s) (b) are chosen from carbohydrates, polyamines and compounds of formula (I): (R1)(R2)(R3)m-A+-CR4R5-(X)nY (I) in which: - Rb R2 and R3, identical or different, represent a C1-C4 alkyl group, preferably a C1-C2 alkyl group, preferably methyl; - A is N or S; - m is 0 or 1; - n is 0 or 1; - X is a divalent, linear or branched, saturated or unsaturated alkyl group having from 1 to 6 carbon atoms, preferably 1 to 4 carbon atoms; carbon, optionally substituted by one or more groups chosen from a hydroxyl (-OH), an amino (-NH2); and - Y is -COO or -OSO3; it being understood that, - when A is S, then m=0 and R4 and R5, identical or different, represent a hydrogen atom or a saturated, unsaturated, linear, branched and / or cyclic hydrocarbon chain, in Cl-CIO, preferably in C1-C6, more preferably in C1-C4; optionally interrupted by one or more heteroatoms or groups chosen from -S-, -N=, -NH- or -C(NH)- and / or optionally substituted by one or more groups chosen from a hydroxyl (-OH), an amino (~NH2), -SH, -COOH, or -CONH2; - when A is N and m = 0, then R4 represents a hydrogen atom or a saturated, linear or branched C1-C8 alkyl group, preferably a C1-C4 alkyl group;and R5 forms, with the nitrogen atom, a saturated heterocycle comprising from 5 to 8 members, preferably from 5 to 6 members, optionally substituted by one or more groups chosen from hydroxyls or C1-C4 alkyls; and - when A is N and m = 1, then R4 and R5, identical or different, represent a hydrogen atom or a saturated, unsaturated, linear, branched and / or cyclic C1-C10, preferably C1-C6, more preferably C1-C4 hydrocarbon chain; optionally interrupted by one or more heteroatoms or groups chosen from -S-, -N=, -NH- or -C(NH)- and / or optionally substituted by one or more groups chosen from a hydroxyl (-OH), an amino (-NH2), -SH, -COOH or -CONH2.;

4. Process according to the preceding claim, in which the osmolyte(s) (b) are chosen from the compounds of formula (I), preferably from the compounds of formula (I) in which Riet R2 are identical and represent a methyl, A is N, Y is -COO, and X, when present, is a divalent, linear or branched, saturated or unsaturated alkyl group having from 1 to 6 carbon atoms, preferably 1 to 4 carbon atoms, preferably 1 to 2 carbon atoms.

5. Process according to the preceding claim, in which R4 represents a hydrogen atom and R5 represents a hydrogen atom or a saturated, linear or branched C1-C6, preferably C1-C4, hydrocarbon chain, optionally substituted by one or more groups chosen from a hydroxyl (-OH), an amino (-NH2), -SH, -COOH or -CONH

6. 2* A method according to any one of the preceding claims, wherein the osmolyte(s) (b) are selected from valine betaine, glutamic acid betaine, glutamine betaine, trimethyllysine, glycine betaine (trimethylglycine), histidine betaine, alanine betaine, choline sulfate, pipecolic acid betaine, proline betaine, hydroxyproline betaine, tyrosine betaine, phenylalanine betaine, tryptophan betaine, leucine betaine, isoleucine betaine, dimethylsulfoniopropionate and mixtures thereof, preferably glycine betaine (trimethylglycine).

7. Process according to any one of the preceding claims, in which the hydroxylated polycarboxylic acid(s), one of their salts or their mixtures (c) are chosen from the compounds corresponding to the formula (II) below: r . (II) I q 1 oh iq ] / 1 L Js o in which: - n is an integer between 1 and 5, better between 1 and 3, preferably n=1 or 2, more preferably n=2; - A is a multivalent, saturated or unsaturated, linear, branched, cyclic, or even aromatic hydrocarbon group, comprising from 1 to 6 carbon atoms, preferably from 1 to 4 carbon atoms, substituted by one or more hydroxyl groups (OH); preferably, A being a multivalent (Cl-C6)alkylene, better (C2-C4)alkylene, or phenylene group, substituted by one or more hydroxyl groups.

8. Process according to any one of the preceding claims, in which the hydroxylated polycarboxylic acid(s), one of their salts or their mixtures (c) are chosen from the compounds corresponding to formula (II) in which A is a (Cl-C6)alkylene group, better still (C2-C4)alkylene, or phenylene group, substituted by 1 or 2 hydroxy groups, preferably 1 hydroxy group; and n = 1 or 2; preferably chosen from the compounds corresponding to formula (II) in which n = 1 or 2, and A is a di- or trivalent (Cl-C6)alkyl group, better still (C2-C4)alkyl, substituted by one or more hydroxy groups, in particular 1 or 2 OH, preferably 1 OH; better, chosen from citric acid, malic acid, tartaric acid, their salts and their mixtures; more preferably, chosen from citric acid, its salts and their mixtures, better citric acid.

9. Method according to any one of the preceding claims, in which the lightening method uses one or more additional oxidizing agent(s) (d), other than the peroxygenated salts, preferably chosen from hydrogen peroxide, hydrogen peroxide generating systems other than the peroxygenated salts and their mixtures, preferably hydrogen peroxide.

10. A method according to any one of the preceding claims, wherein the lightening method uses one or more direct dye(s), preferably chosen from non-ionic direct dyes, anionic direct dyes, cationic direct dyes and mixtures thereof, preferably from azo direct dyes; (poly)methine dyes such as cyanines, hemicyanines and styryls; carbonyl dyes; azine dyes; nitro(hetero)aryl dyes; tri(hetero)arylmethane dyes; porphyrin dyes; phthalocyanine-based dyes and natural direct dyes, alone or in mixtures.

11. Method according to any one of the preceding claims, in which the lightening method uses one or more alkaline agent(s), preferably chosen from ammonia, alkali carbonates or bicarbonates such as sodium (hydrogen)carbonate and potassium (hydrogen)carbonate, ammonium (hydrogen)carbonate, alkali or alkaline earth metal phosphates such as sodium phosphates or potassium phosphates, sodium or potassium hydroxides, alkali or alkaline earth metal silicates or metasilicates such as sodium metasilicate and sodium silicate, and mixtures thereof, preferably from alkali or alkaline earth metal silicates or metasilicates, such as sodium silicate and metasilicate, and carbonates or bicarbonates and mixtures thereof, better still from alkali or alkaline earth metal silicates or metasilicates. earthy,such as sodium silicate and metasilicate, and mixtures thereof.,

12. Method according to any one of the preceding claims, which comprises a step of applying to the keratin fibres a composition (C) comprising compounds (a), (b) and (c), and optionally (d) as defined in any one of the preceding claims, preferably a composition (C) comprising compounds (a), (b), (c) and (d).

13. Method according to claim 12 which comprises, before the step of applying the composition (C), a step of mixing - a composition (Cl) comprising the compounds (a), (b) and (c), and - an oxidizing composition (0) comprising the compound(s) (d).

14. Method according to claim 12 which comprises, before the step of applying the composition (C), a step of mixing the compounds (b) and (c) with a composition (C2) comprising the compound(s) (a), and optionally with an oxidizing composition (0) comprising the compound(s) (d).

15. Process according to any one of claims 1 to 11, which comprises: (i) the application to the keratin fibres of a composition (C3) comprising the compound(s) (a), and optionally (d), preferably of a composition (C3) comprising the compounds (a) and (d), (ii) the application to the keratin fibres of a composition (C4) comprising the compounds (b) and (c), step (ii) being carried out before or after step (i), preferably after.

16. Method according to the preceding claim which comprises, before step (i), a step of mixing a composition (C2) comprising the compound(s) (a) with an oxidizing composition (0) comprising the compound(s) (d).

17. A composition comprising compounds (a), (b), (c), and optionally (d) as defined in any one of claims 1 to 11, preferably compounds (a), (b), (c) and (d).

18. Use of a composition (C) as defined in the preceding claim, for lightening keratin fibers, and in particular hair.

19. Device with at least two compartments, for lightening keratin fibers, comprising at least a first compartment containing a composition (Cl) comprising the compounds (a), (b), (c) as defined in any one of claims 1 to 11, and at least a second compartment containing an oxidizing composition (0) comprising one or more compounds (d) as defined in claim 9.

20. Device with at least two compartments, for lightening keratin fibers, comprising at least a first compartment containing a composition (C2) comprising the compound(s) (a) as defined in any one of claims 1 to 11, at least a second compartment containing a composition (C4) comprising the compounds (b) and (c) as defined in any one of claims 1 to 11, and optionally at least a third compartment containing an oxidizing composition (O) comprising one or more compounds (d) as defined in claim 9.