WO2025051764A1

WO2025051764A1 - Cosmetic treatment process

Info

Publication number: WO2025051764A1
Application number: PCT/EP2024/074650
Authority: WO
Inventors: Thomas Fondin; Lyna ABDAT-VINDEL
Original assignee: LOreal SA
Current assignee: LOreal SA
Priority date: 2023-09-04
Filing date: 2024-09-04
Publication date: 2025-03-13
Anticipated expiration: 2026-03-04
Also published as: FR3152399A1

Abstract

The present invention relates to a cosmetic treatment process, preferably hair treatment process, for keratin fibres, in particular the hair, comprising: - a step of applying a cosmetic composition comprising organosilanes and at least 0.5% by weight of one or more hydroxylated polycarboxylic acids, comprising 2 to 8 carbon atoms, and/or salts thereof, then - a washing step comprising the application of a cosmetic composition comprising anionic and/or amphoteric surfactants, then - a step of applying a cosmetic composition comprising amino acids and hydroxylated (poly)carboxylic acids, comprising 2 to 8 carbon atoms, and/or salts thereof.

Description

Cosmetic treatment process

The present invention relates to a cosmetic hair treatment process, which consists in applying, in a sequential manner, a cosmetic pre-shampoo composition, then a cleansing cosmetic composition of shampoo type, and finally a composition of conditioner type.

Hair may be damaged or embrittled by the action of external atmospheric agents such as light and bad weather, or by mechanical or chemical treatments, such as brushing, combing, dyeing, bleaching, permanent-waving and/or relaxing. To overcome these drawbacks, it is common practice to make use of hair treatments which can condition the hair. These haircare compositions may be conditioning shampoos or hair conditioners, which may be in the form of hair gels or lotions or more or less thick creams.

To improve the cosmetic properties of these compositions, it is known practice to introduce therein conditioning agents, which are intended mainly to repair or limit the harmful or undesirable effects brought about by the various treatments or attacking factors to which hair fibres are more or less repeatedly subjected.

With this aim, it has already been proposed to use, inter alia, organosilanes in cosmetic care compositions, to give hair satisfactory conditioning properties. Such compositions are described, for example, in patent applications FR 2910276, EP 2343042 and EP 2111848.

However, the care compositions described in these documents afford conditioning and disentangling properties that are not sufficiently long-lasting. Specifically, these properties generally do not sufficiently resist washing and tend to diminish from the first shampoo wash. In other words, even though these haircare compositions make it possible to obtain suitable results during and just after their use, it was found that these effects had a tendency to disappear gradually with hair washes; it was thus necessary to regularly renew the application of hair treatments to maintain adequate conditioning effects.

Application WO 2016/083578 has therefore proposed a hair composition for caring for the hair, capable of affording conditioning properties that are not only satisfactory, but also persistent with respect to washing, for example persistent at least after three shampoo washes. This care composition comprises the combination of organosilanes, cationic polymers of high charge density and cationic surfactants.

A hair treatment process comprising the sequential application of a composition comprising organosilanes and of a composition for caring for or washing the hair has also been proposed, for example by EP 2 111 849. This document describes in particular the use of a composition comprising an organosilane as a pre-shampoo, that is to say applied to the hair before washing with a shampoo comprising at least one anionic surfactant and an amphoteric surfactant. This process makes it possible in particular to obtain supple, smooth hair which disentangles well.

However, it is still possible to improve the performance results provided by such compositions, in particular in terms of providing strength (denser, more rigid hair), while at the same time retaining a certain lightness thereof (invigorated and tangle-free hair) and also in terms of cosmetic properties such as disentangling and smooth feel; this being immediately, at the time of application of the composition to the hair (at T0), but also persistently, that is to say after several shampoo washes, for example persistence after 2 to 4 shampoo washes.

That is the objective sought by the present invention.

The subject of the present invention is therefore a cosmetic treatment process, preferably hair treatment process, for keratin fibres, in particular the hair, in particular human hair, comprising:

- a step (i) of applying, to said keratin fibres, a cosmetic composition A comprising one or more organosilanes and at least 0.5% by weight of one or more hydroxylated polycarboxylic acids, comprising 2 to 8 carbon atoms, and/or salts thereof, then

- a step (ii) of washing said keratin fibres, comprising the application of a cleansing cosmetic composition B comprising one or more anionic surfactants and/or one or more amphoteric surfactants, then

- a step (iii) of applying, to said keratin fibres, a cosmetic composition C comprising one or more compounds of amino acid type and one or more hydroxylated (poly)carboxylic acids, comprising from 2 to 8 carbon atoms, and/or salts thereof.

The process according to the invention makes it possible to give the hair strength and resistance, hence a visible reinforcement of the fibre, thus resulting in particular in reducing breaking of the hair during subsequent styling or blow drying operations and/or in reducing the presence of split ends of the hair.

In addition, the cosmetic properties of the fibre, such as disentangling, smooth feel and elasticity, are improved.

These properties may be persistent with respect to subsequent shampoo washes, for example persistent up to at least 3 shampoo washes.

The cosmetic treatment process according to the invention therefore comprises a step (i) comprising the application to the hair of a cosmetic composition A as defined below. This composition A is used as a pre-shampoo (before using a shampoo).

This step may or may not be followed by a leave-on step, for example a leave-on time of from 1 to 15 minutes, in particular from 2 to 5 minutes.

This step can also be optionally followed by a rinsing step, for example a step of rinsing with water, before carrying out step (ii). Preferably, said step (i) is not followed by a rinsing step.

The cosmetic treatment process, in particular hair treatment process, according to the invention also comprises a washing step (ii), consisting in applying to the hair a washing cosmetic composition B as defined below.

This step may or may not be followed by a leave-on step, for example a leave-on time of from 1 to 15 minutes, in particular from 2 to 5 minutes. It can also be followed by a rinsing step, for example rinsing with water.

Preferably, the process according to the invention comprises an intermediate rinsing step between steps (ii) and (iii).

The cosmetic treatment process, in particular hair treatment process, according to the invention also comprises a step (iii) consisting in applying to the hair a cosmetic composition C as defined below, and comprising one or more compounds of amino acid type and one or more hydroxylated (poly)carboxylic acids, having 2 to 8 carbon atoms, and/or salts thereof.

This step may or may not be followed by a leave-on step, for example a leave-on time of from 1 to 15 minutes, in particular from 2 to 5 minutes. It can also be followed by a rinsing step, for example rinsing with water, and/or a drying step, for example with a hair dryer or in the open air.

Preferably, the process according to the invention comprises a rinsing step and a drying step, after step (iii).

Step (i) of applying the composition A and step (ii) of washing with the composition B are carried out successively, or sequentially, which means that the application step (i) is carried out before the washing step (ii), it being possible for intermediate steps, for example leave-on and/or rinsing steps, to be present between these two steps.

The time separating said step (i) of applying the composition A (or pre-shampoo composition) from step (ii) of washing the hair is at most 60 minutes; it can, for example, be of between 30 seconds and 60 minutes, in particular between 1 and 30 minutes, or even between 2 and 20 minutes, even better still between 3 and 15 minutes and very particularly between 4 and 10 minutes.

The washing step (ii) and step (iii) of applying the composition C are carried out successively, or sequentially, which means that the washing step (ii) is carried out before the application step (iii), it being possible for intermediate steps, for example leave-on and/or rinsing steps, to be present between these two steps.

The time separating said washing step (ii) from the step (iii) of applying the composition C is at most 60 minutes; it may for example be between 30 seconds and 60 minutes, in particular between 1 and 30 minutes, or even between 2 and 20 minutes, even better still between 3 and 15 minutes, and most particularly between 4 and 10 minutes.

The process according to the invention advantageously makes it possible to provide visible reinforcement of the fibre (= provision of force) and instantaneous disentangling, in particular on wet hair, and in a manner that is persistent with respect to subsequent shampoo washes, for example persistent up to at least 3 shampoo washes.

Another subject of the invention is therefore the use of said process for the visible reinforcement of the fibre (= provision of force) and/or for improving disentangling, in particular on wet hair, and advantageously in a manner that is persistent with respect to subsequent shampoo washes, for example persistent up to at least 3 shampoo washes.

In the present description, the expression "at least one" is equivalent to the expression "one or more" and can be substituted for said expression; the expression "between x and y" is equivalent to the expression "ranging from x to y" and can be substituted for said expression, and implies that the limits are included.

A/ Application step (i)

The cosmetic treatment process according to the invention therefore comprises a step (i) of applying to said keratin fibres a cosmetic composition A comprising one or more organosilanes and at least 0.5% by weight of one or more hydroxylated polycarboxylic acids, comprising 2 to 8 carbon atoms, and/or salts thereof.

This cosmetic composition, or even hair composition, may be described as a pre-shampoo composition.

1/ Organosilanes

The composition A used according to the process of the invention comprises one or more organosilanes.

The organosilane(s) are preferably chosen from the compounds of formula (I) and/or oligomers thereof and/or hydrolysis products thereof:

R₁Si(OR₂)z(R₃)x(OH)y (I)

in which:

- R₁ is a cyclic or acyclic, linear or branched, saturated or unsaturated C₁-C₂₂, in particular C₂-C₂₀, hydrocarbon chain, which may be substituted with a group chosen from amine groups NH₂ or NHR (R being a linear or branched C₁-C₂₀, in particular C₁-C₆, alkyl, a C₃-C₄₀ cycloalkyl or a C₆-C₃₀ aromatic radical); the hydroxyl group (OH), a thiol group, an aryl group (more particularly benzyl), which is possibly substituted with an NH₂ or NHR group; it being possible for R₁ to be interrupted with a heteroatom (O, S or NH) or a carbonyl group (CO),

- R₂ and R₃, which may be identical or different, represent a linear or branched alkyl group comprising from 1 to 6 carbon atoms,

- y denotes an integer ranging from 0 to 3,

- z denotes an integer ranging from 0 to 3, and

- x denotes an integer ranging from 0 to 2, with z + x + y = 3.

The term "oligomer" is intended to mean the polymerization products of the compounds of formula (I) comprising from 2 to 10 silicon atoms.

Preferably, R₁ is a linear or branched, preferably linear, saturated C₁-C₂₂, in particular C₁-C₁₂, hydrocarbon chain, which may be substituted with an amine group NH₂ or NHR (R = C₁-C₂₀, in particular C₁-C₆, alkyl).

Better still, R₁ is a saturated linear or branched C₁-C₁₂, in particular C₂-C₆, hydrocarbon chain substituted with an amine group NH₂. Preferentially, R₁ represents a C₂-C₆, preferably C₂-C₄, aminoalkyl group.

Preferably, R₂ represents an alkyl group comprising from 1 to 4 carbon atoms, better still a linear alkyl group comprising from 1 to 4 carbon atoms, and preferably the ethyl group.

Preferably, z ranges from 1 to 3. Preferably, y = 0. Preferentially, z = 3, and therefore x = y = 0.

Preferably, the organosilanes used in the context of the invention correspond to formula (I) in which R₁ is a saturated linear or branched C₁-C₁₂, in particular C₂-C₆, hydrocarbon chain substituted with an amine group NH₂, R₂ represents an alkyl group comprising from 1 to 4 carbon atoms, and z = 3 (and therefore x = y = 0).

Preferably, the composition A according to the invention comprises one or more organosilanes chosen from methyltriethoxysilane (MTES), octyltriethoxysilane (OTES), dodecyltriethoxysilane, octadecyltriethoxysilane, hexadecyltriethoxysilane, 3-aminopropyltriethoxysilane (APTES), 2-aminoethyltriethoxysilane (AETES), 3-aminopropylmethyldiethoxysilane, N-(2-aminoethyl)-3-aminopropyltriethoxysilane, 3-(m-aminophenoxy)propyltrimethoxysilane, p-aminophenyltrimethoxysilane, N-(2-aminoethylaminomethyl)phenethyltrimethoxysilane, and oligomers thereof, and/or mixtures thereof; and more particularly chosen from methyltriethoxysilane (MTES) and 3-aminopropyltriethoxysilane (APTES), oligomers thereof, hydrolysis products thereof and/or mixtures thereof; and even better still chosen from 3-aminopropyltriethoxysilane (APTES), oligomers thereof and/or hydrolysis products thereof.

Preferably, the organosilane(s) are present in the composition A according to the invention in a total content of at least 6% by weight relative to the total weight of the composition, preferably in a total content ranging from 6% to 20% by weight, preferentially from 7% to 15% by weight and better still from 8% to 13% by weight, relative to the total weight of the composition.

Preferably, the organosilane(s) corresponding to formula (I) in which R₁ is a saturated linear or branched C₁-C₁₂, in particular C₂-C₆, hydrocarbon chain substituted with an amine group NH₂, R₂ represents an alkyl group comprising from 1 to 4 carbon atoms, and z = 3 (and thus x = y = 0) are present in the composition A according to the invention in a total content of at least 6% by weight relative to the total weight of the composition, preferably in a total content ranging from 6% to 20% by weight, preferentially from 7% to 15% by weight, better still from 8% to 13% by weight, relative to the total weight of the composition.

Preferably, the organosilane(s) chosen from 3-aminopropyltriethoxysilane (APTES), oligomers thereof and/or hydrolysis products thereof are present in the composition A according to the invention in a total content of at least 6% by weight relative to the total weight of the composition, preferably in a total content ranging from 6% to 20% by weight, preferentially from 7% to 15% by weight and better still from 8% to 13% by weight, relative to the total weight of the composition.

2/ Cationic polymers

The cosmetic composition A used in step (i) may advantageously comprise one or more cationic polymers.

The term “cationic polymer” denotes any non-silicone (not comprising any silicon atoms) polymer containing cationic groups and/or groups that can be ionized into cationic groups and not containing any anionic groups and/or groups that can be ionized into anionic groups.

The cationic polymers that can be used preferably have a cationic charge density greater than or equal to 4 milliequivalents/gram (meq/g), better still greater than or equal to 5 meq/g, or even ranging from 5 to 20 meq/g.

The cationic charge density of a polymer corresponds to the number of moles of cationic charges per unit mass of polymer under the conditions in which the latter is completely ionized. It may be determined by calculation if the structure of the polymer is known, i.e. the structure of the monomers constituting the polymer and their molar proportion or weight proportion. It may also be determined experimentally by the Kjeldahl method.

The cationic polymers that may be used preferably have a weight-average molar mass (Mw) of between 500 and 5×10⁶ approximately and preferably between 10³ and 3×10⁶ approximately.

The cationic polymers that can be used may optionally be associative, preferably non-associative.

The term "associative polymer" refers to an amphiphilic polymer that is capable, in an aqueous medium, of reversibly combining with itself or with other molecules. It generally includes, in its chemical structure, at least one hydrophilic region or group and at least one hydrophobic region or group. In particular, the hydrophobic group may be a fatty hydrocarbon chain such as a linear or branched alkyl, linear or branched arylalkyl or linear or branched alkylaryl group comprising at least 8 carbon atoms, preferably 8 to 30 carbon atoms, better still from 12 to 24 carbon atoms.

Among the cationic polymers, mention may be made of:

(1) homopolymers or copolymers derived from acrylic or methacrylic esters or amides and comprising at least one of the units having the following formula:

in which:

- R₃, which may be identical or different, denote a hydrogen atom or a CH₃ radical;

- A, which may be identical or different, represent a linear or branched divalent alkyl group of 1 to 6 carbon atoms, preferably 2 or 3 carbon atoms, or a hydroxyalkyl group of 1 to 4 carbon atoms;

- R₄, R₅ and R₆, which may be identical or different, represent an alkyl group having from 1 to 18 carbon atoms or a benzyl radical, preferably an alkyl group having from 1 to 6 carbon atoms;

- R₁ and R₂, which may be identical or different, represent a hydrogen atom or an alkyl group having from 1 to 6 carbon atoms, preferably methyl or ethyl;

- X denotes an anion derived from a mineral or organic acid, such as a methosulfate anion or a halide such as chloride or bromide.

The copolymers of family (1) may also contain one or more units derived from comonomers that may be chosen from the family of acrylamides, methacrylamides, diacetone acrylamides, acrylamides and methacrylamides substituted on the nitrogen with lower (C₁-C₄) alkyls, acrylic or methacrylic acid esters, vinyllactams such as vinylpyrrolidone or vinylcaprolactam, and vinyl esters.

Among these copolymers of family (1), mention may be made of:

- copolymers of acrylamide and of dimethylaminoethyl methacrylate quaternized with dimethyl sulfate or with a dimethyl halide, such as the product sold under the name Hercofloc by Hercules,

- copolymers of acrylamide and of methacryloyloxyethyltrimethylammonium chloride, such as the products sold under the name Bina Quat P 100 by Ciba Geigy,

- the copolymer of acrylamide and of methacryloyloxyethyltrimethylammonium methosulfate, such as the product sold under the name Reten by Hercules,

- quaternized or non-quaternized vinylpyrrolidone/dialkylaminoalkyl acrylate or methacrylate copolymers, such as the products sold under the name Gafquat by ISP, for instance Gafquat 734 or Gafquat 755, or alternatively the products known as Copolymer 845, 958 and 937,

- dimethylaminoethyl methacrylate/vinylcaprolactam/vinylpyrrolidone terpolymers, such as the product sold under the name Gaffix VC 713 by ISP,

- vinylpyrrolidone/methacrylamidopropyldimethylamine copolymers, such as the products sold under the name Styleze CC 10 by ISP;

- quaternized vinylpyrrolidone/dimethylaminopropylmethacrylamide copolymers such as the product sold under the name Gafquat HS 100 by ISP;

- preferably crosslinked polymers of methacryloyloxy(C₁-C₄)alkyltri(C₁-C₄)alkylammonium salts, such as the polymers obtained by homopolymerization of dimethylaminoethyl methacrylate quaternized with methyl chloride, or by copolymerization of acrylamide with dimethylaminoethyl methacrylate quaternized with methyl chloride, the homopolymerization or copolymerization being followed by crosslinking with an olefinically unsaturated compound, in particular methylenebisacrylamide. Use may be made more particularly of a crosslinked acrylamide/methacryloyloxyethyltrimethylammonium chloride copolymer (20/80 by weight) in the form of a dispersion comprising 50% by weight of said copolymer in mineral oil. This dispersion is sold under the name Salcare® SC 92 by Ciba. Use may also be made of a crosslinked methacryloyloxyethyltrimethylammonium chloride homopolymer comprising approximately 50% by weight of the homopolymer in mineral oil or in a liquid ester. These dispersions are sold under the names Salcare® SC 95 and Salcare® SC 96 by Ciba;

(2) cationic polysaccharides, particularly cationic celluloses and galactomannan gums. Among the cationic polysaccharides, mention may be made more particularly of cellulose ether derivatives including quaternary ammonium groups, cationic cellulose copolymers or cellulose derivatives grafted with a water-soluble quaternary ammonium monomer and cationic galactomannan gums.

The cellulose ether derivatives including quaternary ammonium groups are in particular described in FR 1 492 597, and mention may be made of the polymers sold under the name Ucare Polymer JR (JR 400 LT, JR 125 and JR 30M) or LR (LR 400 and LR 30M) by Amerchol. These polymers are also defined in the CTFA dictionary as quaternary ammoniums of hydroxyethylcellulose that have reacted with an epoxide substituted with a trimethylammonium group.

Cationic cellulose copolymers or cellulose derivatives grafted with a water-soluble quaternary ammonium monomer are described in particular in patent US 4 131 576, and mention may be made of hydroxyalkyl celluloses, for instance hydroxymethyl, hydroxyethyl or hydroxypropyl celluloses in particular grafted with a methacryloylethyltrimethylammonium, methacrylamidopropyltrimethylammonium or dimethyldiallylammonium salt. The commercial products corresponding to this definition are more particularly the products sold under the names Celquat L 200 and Celquat H 100 by National Starch.

Cationic galactomannan gums are described more particularly in patents US 3 589 578 and US 4 031 307, and mention may be made of guar gums comprising cationic trialkylammonium groups. Use is made, for example, of guar gums modified with a 2,3-epoxypropyltrimethylammonium salt (for example a chloride). Such products are in particular sold under the names Jaguar C13 S, Jaguar C 15, Jaguar C 17 and Jaguar C162 by Rhodia;

(3) polymers formed from piperazinyl units and divalent alkylene or hydroxyalkylene radicals containing linear or branched chains, optionally interrupted with oxygen, sulfur or nitrogen atoms or with aromatic or heterocyclic rings, and also the oxidation and/or quaternization products of these polymers;

(4) water-soluble polyaminoamides prepared in particular by polycondensation of an acidic compound with a polyamine; these polyaminoamides can be crosslinked with an epihalohydrin, a diepoxide, a dianhydride, an unsaturated dianhydride, a bis-unsaturated derivative, a bis-halohydrin, a bis-azetidinium, a bis-haloacyldiamine, a bis-alkyl halide or alternatively with an oligomer resulting from the reaction of a difunctional compound which is reactive with a bis-halohydrin, a bis-azetidinium, a bis-haloacyldiamine, a bis-alkyl halide, an epihalohydrin, a diepoxide or a bis-unsaturated derivative; the crosslinking agent being used in proportions ranging from 0.025 to 0.35 mol per amine group of the polyaminoamide; these polyaminoamides can be alkylated or, if they include one or more tertiary amine functions, they can be quaternized;

(5) polyaminoamide derivatives resulting from the condensation of polyalkylene polyamines with polycarboxylic acids followed by alkylation with difunctional agents. Mention may be made, for example, of adipic acid/dialkylaminohydroxyalkyldialkylenetriamine polymers in which the alkyl radical includes from 1 to 4 carbon atoms and preferably denotes methyl, ethyl or propyl. Among these derivatives, mention may be made more particularly of the adipic acid/dimethylaminohydroxypropyl/diethylenetriamine polymers sold under the name Cartaretine F, F4 or F8 by Sandoz;

(6) polymers obtained by reacting a polyalkylene polyamine including two primary amine groups and at least one secondary amine group with a dicarboxylic acid chosen from diglycolic acid and saturated aliphatic dicarboxylic acids containing from 3 to 8 carbon atoms; the mole ratio between the polyalkylene polyamine and the dicarboxylic acid preferably being between 0.8:1 and 1.4:1; the resulting polyaminoamide being reacted with epichlorohydrin in a mole ratio of epichlorohydrin relative to the secondary amine group of the polyaminoamide preferably of between 0.5:1 and 1.8:1. Polymers of this type are sold in particular under the name Hercosett 57 by Hercules Inc. or under the name PD 170 or Delsette 101 by Hercules in the case of the adipic acid/epoxy-propyl/diethylenetriamine copolymer;

(7) cyclopolymers of alkyldiallylamine or of dialkyldiallylammonium, such as the homopolymers or copolymers including, as main constituent of the chain, units corresponding to formula (I) or (II):

in which

- k and t are equal to 0 or 1, the sum k + t being equal to 1;

- R₁₂ denotes a hydrogen atom or a methyl radical;

- R₁₀ and R₁₁, independently of one another, denote a C₁-C₆ alkyl group, a C₁-C₅ hydroxyalkyl group, a C₁-C₄ amidoalkyl group; or alternatively R₁₀ and R₁₁ may denote, together with the nitrogen atom to which they are attached, a heterocyclic group such as piperidinyl or morpholinyl; R₁₀ and R₁₁, independently of one another, preferably denote a C₁-C₄ alkyl group;

- Y^- is an anion such as bromide, chloride, acetate, borate, citrate, tartrate, bisulfate, bisulfite, sulfate or phosphate.

Mention may be made more particularly of the homopolymer of dimethyldiallylammonium salts (for example chloride) for example sold under the name Merquat 100 by Nalco and the copolymers of diallyldimethylammonium salts (for example chloride) and of acrylamide, in particular sold under the name Merquat 550 or Merquat 7SPR;

(8) quaternary diammonium polymers comprising repeating units of formula:

in which:

- R₁₃, R₁₄, R₁₅ and R₁₆, which may be identical or different, represent aliphatic, alicyclic or arylaliphatic radicals comprising from 1 to 20 carbon atoms or C₁-C₁₂ hydroxyalkyl aliphatic radicals;

or else R₁₃, R₁₄, R₁₅ and R₁₆, together or separately, form, with the nitrogen atoms to which they are attached, heterocycles optionally comprising a second non-nitrogen heteroatom;

or else R₁₃, R₁₄, R₁₅ and R₁₆ represent a linear or branched C₁-C₆ alkyl radical substituted with a nitrile, ester, acyl, amide or -CO-O-R₁₇-D or -CO-NH-R₁₇-D group, where R₁₇ is an alkylene and D is a quaternary ammonium group;

- A₁ and B₁ represent linear or branched, saturated or unsaturated, divalent polymethylene groups comprising from 2 to 20 carbon atoms, which may contain, linked to or intercalated in the main chain, one or more aromatic rings or one or more oxygen or sulfur atoms or sulfoxide, sulfone, disulfide, amino, alkylamino, hydroxyl, quaternary ammonium, ureido, amide or ester groups, and

- X^- denotes an anion derived from a mineral or organic acid;

it being understood that A₁, R₁₃ and R₁₅ can form, with the two nitrogen atoms to which they are attached, a piperazine ring;

in addition, if A₁ denotes a linear or branched, saturated or unsaturated alkylene or hydroxyalkylene radical, B₁ may also denote a group (CH₂)_n-CO-D-OC-(CH₂)_p- with n and p, which may be identical or different, being integers ranging from 2 to 20, and D denoting:

a) a glycol residue of formula -O-Z-O-, in which Z denotes a linear or branched hydrocarbon radical or a group corresponding to one of the following formulae: -(CH₂CH₂O)_x-CH₂CH₂- and -[CH₂CH(CH₃)O]_y-CH₂CH(CH₃)-, in which x and y denote an integer from 1 to 4, representing a defined and unique degree of polymerization or any number from 1 to 4 representing an average degree of polymerization;

b) a bis-secondary diamine residue, such as a piperazine derivative;

c) a bis-primary diamine residue of formula -NH-Y-NH-, where Y denotes a linear or branched hydrocarbon radical, or else the divalent radical -CH₂-CH₂-S-S-CH₂-CH₂-;

d) a ureylene group of formula -NH-CO-NH-.

Preferably, X^- is an anion such as chloride or bromide. These polymers have a number-average molar mass (Mn) generally of between 1000 and 100 000.

Mention may be made more particularly of polymers which are constituted of repeating units corresponding to the formula:

in which R₁, R₂, R₃ and R₄, which may be identical or different, denote an alkyl or hydroxyalkyl radical containing from 1 to 4 carbon atoms, n and p are integers ranging from 2 to 20, and X^- is an anion derived from a mineral or organic acid.

A particularly preferred compound of formula (IV) is the one for which R₁, R₂, R₃ and R₄ represent a methyl radical, n = 3, p = 6 and X = Cl, known as Hexadimethrine chloride according to the INCI (CTFA) nomenclature;

(9) polyquaternary ammonium polymers comprising units of formula (V):

in which:

- R₁₈, R₁₉, R₂₀ and R₂₁, which may be identical or different, represent a hydrogen atom or a methyl, ethyl, propyl, β-hydroxyethyl, β-hydroxypropyl or -CH₂CH₂(OCH₂CH₂)_pOH radical, in which p is equal to 0 or to an integer between 1 and 6, with the proviso that R₁₈, R₁₉, R₂₀ and R₂₁ do not simultaneously represent a hydrogen atom,

- r and s, which may be identical or different, are integers between 1 and 6,

- q is equal to 0 or to an integer between 1 and 34,

- X^- denotes an anion such as a halide,

- A denotes a divalent dihalide radical or preferably represents -CH₂-CH₂-O-CH₂-CH₂-.

Examples that may be mentioned include the products Mirapol® A 15, Mirapol® AD1, Mirapol® AZ1 and Mirapol® 175 sold by Miranol;

(10) quaternary polymers of vinylpyrrolidone and of vinylimidazole, such as, for example, the products sold under the names Luviquat® FC 905, FC 550 and FC 370 by BASF;

(11) polyamines, such as Polyquart® H sold by Cognis, which is referenced under the name Polyethylene Glycol (15) Tallow Polyamine in the CTFA dictionary;

(12) polymers including in their structure:

(a) one or more units corresponding to formula (A) below:

(b) optionally one or more units corresponding to formula (B) below:

In other words, these polymers may be particularly chosen from homopolymers or copolymers including one or more units derived from vinylamine and optionally one or more units derived from vinylformamide.

Preferably, these cationic polymers are chosen from polymers including, in their structure, from 5 mol% to 100 mol% of units corresponding to formula (A) and from 0 to 95 mol% of units corresponding to formula (B), preferentially from 10 mol% to 100 mol% of units corresponding to formula (A) and from 0 to 90 mol% of units corresponding to formula (B).

These polymers may be obtained, for example, by partial hydrolysis of polyvinylformamide. This hydrolysis may take place in acidic or basic medium.

The weight-average molecular mass of said polymer, measured by light scattering, may range from 1000 to 3 000 000 g/mol, preferably from 10 000 to 1 000 000 and more particularly from 100 000 to 500 000 g/mol.

The polymers including units of formula (A) and optionally units of formula (B) are in particular sold under the name Lupamin by BASF, for instance, in a non-limiting manner, the products sold under the names Lupamin 9095, Lupamin 5095, Lupamin 1095, Lupamin 9030 (or Luviquat 9030) and Lupamin 9010.

Cationic polymers chosen from those of families (1), (2), (7) and (10) mentioned above are most particularly preferred, better still those of families (1), (2) and (7).

Among the associative cationic polymers which can be used, mention may be made, alone or as a mixture, of:

- (A) cationic associative polyurethanes, which can be represented by general formula (Ia) below: R-X-(P)n-[L-(Y)m]r-L'-(P')p-X'-R'

in which:

R and R’, which may be identical or different, represent a hydrophobic group or a hydrogen atom;

X and X', which may be identical or different, represent a group comprising an amine function optionally bearing a hydrophobic group, or alternatively a group L'';

L, L’ and L”, which may be identical or different, represent a group derived from a diisocyanate;

P and P’, which may be identical or different, represent a group including an amine function optionally bearing a hydrophobic group;

Y represents a hydrophilic group;

r is an integer between 1 and 100 inclusive, preferably between 1 and 50 inclusive and in particular between 1 and 25 inclusive;

n, m and p are each, independently of one another, between 0 and 1000 inclusive;

the molecule containing at least one protonated or quaternized amine function and at least one hydrophobic group.

Preferably, the only hydrophobic groups are the groups R and R' at the chain ends.

One preferred family of cationic associative polyurethanes is the one corresponding to formula (Ia) described above, in which:

R and R’ both independently represent a hydrophobic group,

X and X’ each represent a group L”,

n and p are integers which are inclusively between 1 and 1000 and L, L’, L’’, P, P’, Y and m have the meaning indicated above.

Another preferred family of cationic associative polyurethanes is the one corresponding to formula (Ia) above in which:

- n = p = 0 (the polymers do not include any units derived from a monomer containing an amine function, incorporated into the polymer during the polycondensation),

- the protonated amine functions result from the hydrolysis of excess isocyanate functions, at the chain end, followed by alkylation of the primary amine functions formed with alkylating agents containing a hydrophobic group, i.e. compounds of the type RQ or R'Q, in which R and R' are as defined above and Q denotes a leaving group such as a halide or a sulfate.

Yet another preferred family of cationic associative polyurethanes is the one corresponding to formula (Ia) above in which:

R and R’ both independently represent a hydrophobic group,

X and X’ both independently represent a group including a quaternary amine,

n = p = 0, and

L, L’, Y and m have the meaning indicated above.

The number-average molecular mass (Mn) of the cationic associative polyurethanes is preferably between 400 and 500 000 inclusive, in particular between 1000 and 400 000 inclusive and ideally between 1000 and 300 000 inclusive.

The term “hydrophobic group” is intended to mean a radical or polymer containing a saturated or unsaturated, linear or branched hydrocarbon chain, which may contain one or more heteroatoms such as P, O, N or S, or a radical containing a perfluoro or silicone chain. When the hydrophobic group denotes a hydrocarbon radical, it includes at least 10 carbon atoms, preferably from 10 to 30 carbon atoms, in particular from 12 to 30 carbon atoms and more preferentially from 18 to 30 carbon atoms.

Preferentially, the hydrocarbon group originates from a monofunctional compound.

By way of example, the hydrophobic group may be derived from a fatty alcohol such as stearyl alcohol, dodecyl alcohol or decyl alcohol. It may also denote a hydrocarbon polymer, for instance polybutadiene.

When X and/or X’ denote(s) a group including a tertiary or quaternary amine, X and/or X’ may represent one of the following formulae:

in which:

R₂ represents a linear or branched alkylene radical containing from 1 to 20 carbon atoms, optionally comprising a saturated or unsaturated ring, or an arylene radical, one or more of the carbon atoms possibly being replaced with a heteroatom chosen from N, S, O and P;

R₁ and R₃, which may be identical or different, denote a linear or branched C₁-C₃₀ alkyl or alkenyl radical or an aryl radical, at least one of the carbon atoms possibly being replaced with a heteroatom chosen from N, S, O and P;

A^- is a physiologically acceptable anionic counterion such as a halide, for instance a chloride or bromide, or a mesylate.

The groups L, L’ and L” represent a group of formula:

in which:

Z represents -O-, -S- or -NH-; and

R₄ represents a linear or branched alkylene radical containing from 1 to 20 carbon atoms, optionally comprising a saturated or unsaturated ring, or an arylene radical, one or more of the carbon atoms possibly being replaced with a heteroatom chosen from N, S, O and P.

The groups P and P’ comprising an amine function may represent at least one of the following formulae:

in which:

R₅ and R₇ have the same meanings as R₂ defined above;

R₆, R₈ and R₉ have the same meanings as R₁ and R₃ defined above;

R₁₀ represents a linear or branched, optionally unsaturated alkylene group possibly containing one or more heteroatoms chosen from N, O, S and P;

and A^- is a physiologically acceptable anionic counterion such as a halide, for instance chloride or bromide, or mesylate.

As regards the meaning of Y, the term “hydrophilic group” means a polymeric or non-polymeric water-soluble group.

By way of example, when it is not a polymer, mention may be made of ethylene glycol, diethylene glycol and propylene glycol.

When it is a hydrophilic polymer, in accordance with one preferred embodiment, mention may be made, for example, of polyethers, sulfonated polyesters, sulfonated polyamides or a mixture of these polymers. The hydrophilic compound is preferentially a polyether and in particular a poly(ethylene oxide) or poly(propylene oxide).

The cationic associative polyurethanes of formula (Ia) according to the invention are formed from diisocyanates and from various compounds bearing functions containing labile hydrogen. The functions containing labile hydrogen may be alcohol, primary or secondary amine, or thiol functions, giving, after reaction with the diisocyanate functions, polyurethanes, polyureas and polythioureas, respectively. In the present invention, the term “polyurethanes” encompasses these three types of polymer, namely polyurethanes per se, polyureas and polythioureas, and also copolymers thereof.

A first type of compound involved in the preparation of the polyurethane of formula (Ia) is a compound including at least one unit bearing an amine function. This compound may be multifunctional, but the compound is preferentially difunctional, that is to say that, according to a preferential embodiment, this compound includes two labile hydrogen atoms borne, for example, by a hydroxyl, primary amine, secondary amine or thiol function. A mixture of multifunctional and difunctional compounds in which the percentage of multifunctional compounds is low may also be used.

As mentioned above, this compound may include more than one unit containing an amine function. In this case, it is a polymer bearing a repetition of the unit containing an amine function.

Compounds of this type may be represented by one of the following formulae:

HZ-(P)_n-ZH, or HZ-(P')_p-ZH, in which Z, P, P', n and p are as defined above.

Examples that may be mentioned include N-methyldiethanolamine, N-tert-butyldiethanolamine and N-sulfoethyldiethanolamine.

The second compound involved in the preparation of the polyurethane of formula (Ia) is a diisocyanate corresponding to the formula:

O=C=N-R₄-N=C=O in which R₄ is defined above.

By way of example, mention may be made of methylenediphenyl diisocyanate, methylenecyclohexane diisocyanate, isophorone diisocyanate, tolylene diisocyanate, naphthalene diisocyanate, butane diisocyanate and hexane diisocyanate.

A third compound involved in the preparation of the polyurethane of formula (Ia) is a hydrophobic compound intended to form the hydrophobic end groups of the polymer of formula (Ia).

This compound is constituted of a hydrophobic group and a function containing labile hydrogen, for example a hydroxyl, primary or secondary amine, or thiol function.

By way of example, this compound may be a fatty alcohol such as stearyl alcohol, dodecyl alcohol or decyl alcohol. When this compound includes a polymeric chain, it may be, for example, α-hydroxylated hydrogenated polybutadiene.

The hydrophobic group of the polyurethane of formula (Ia) may also result from the quaternization reaction of the tertiary amine of the compound including at least one tertiary amine unit. Thus, the hydrophobic group is introduced via the quaternizing agent. This quaternizing agent is a compound of the type RQ or R'Q, in which R and R' are as defined above and Q denotes a leaving group such as a halide, a sulfate, etc.

The cationic associative polyurethane may also comprise a hydrophilic block. This block is provided by a fourth type of compound involved in the preparation of the polymer. This compound may be multifunctional. It is preferably difunctional. It is also possible to have a mixture in which the percentage of multifunctional compound is low.

The functions containing labile hydrogen are alcohol, primary or secondary amine, or thiol functions. This compound may be a polymer terminated at the chain ends with one of these functions containing labile hydrogen.

When it is a hydrophilic polymer, mention may be made, for example, of polyethers, sulfonated polyesters and sulfonated polyamides, or a mixture of these polymers. Preferentially, the hydrophilic compound is a polyether and in particular a poly(ethylene oxide) or poly(propylene oxide).

The hydrophilic group termed Y in the formula (Ia) is optional. Specifically, the units containing a quaternary or protonated amine function may be sufficient to provide the solubility or water-dispersibility required for this type of polymer in an aqueous solution.

Although the presence of a hydrophilic group Y is optional, cationic associative polyurethanes including such a group are, however, preferred.

- (B) quaternized cellulose derivatives, and in particular quaternized celluloses modified with groups comprising at least one fatty chain, such as linear or branched alkyl groups, linear or branched arylalkyl groups, or linear or branched alkylaryl groups, preferably linear or branched alkyl groups, these groups comprising at least 8 carbon atoms, in particular from 8 to 30 carbon atoms, better still from 10 to 24, or even from 10 to 14, carbon atoms; or mixtures thereof.

Preferably, mention may be made of quaternized hydroxyethylcelluloses modified with groups comprising at least one fatty chain, such as linear or branched alkyl groups, linear or branched arylalkyl groups, or linear or branched alkylaryl groups, preferably linear or branched alkyl groups, these groups comprising at least 8 carbon atoms, in particular from 8 to 30 carbon atoms, better still from 10 to 24, or even from 10 to 14, carbon atoms; or mixtures thereof.

Preferentially, mention may be made of the hydroxyethylcelluloses of formula (Ib):

in which:

- R represents an ammonium group RaRbRcN⁺-, Q^- in which Ra, Rb and Rc, which may be identical or different, represent a hydrogen atom or a linear or branched C₁-C₃₀ alkyl, and Q^- represents an anionic counterion such as a halide, for instance a chloride or bromide; preferably an alkyl;

- R' represents an ammonium group R'aR'bR'cN⁺-, Q'^- in which R'a, R'b and R'c, which may be identical or different, represent a hydrogen atom or a linear or branched C₁-C₃₀ alkyl, and Q'^- represents an anionic counterion such as a halide, for instance a chloride or bromide; preferably an alkyl;

it being understood that at least one of the radicals Ra, Rb, Rc, R'a, R'b and R'c represents a linear or branched C₈-C₃₀ alkyl;

- n, x and y, which may be identical or different, represent an integer of between 1 and 10 000.

Preferably, in formula (Ib), at least one of the radicals Ra, Rb, Rc, R'a, R'b and R'c represents a linear or branched C₈-C₃₀, better still C₁₀-C₂₄, or even C₁₀-C₁₄, alkyl; mention may be made in particular of the dodecyl radical (C12). Preferably, the other radical(s) represent a linear or branched C₁-C₄ alkyl, in particular methyl.

Preferably, in formula (Ib), only one of the radicals Ra, Rb, Rc, R'a, R'b and R'c represents a linear or branched C₈-C₃₀, better still C₁₀-C₂₄, or even C₁₀-C₁₄, alkyl; mention may be made in particular of the dodecyl radical (C12). Preferably, the other radicals represent a linear or branched C₁-C₄ alkyl, in particular methyl.

Even better still, R may be a group chosen from –N⁺(CH₃)₃, Q’^- and –N⁺(C₁₂H₂₅)(CH₃)₂, Q’^-, preferably a group –N⁺(CH₃)₃, Q’^-.

Even better still, R' may be a group –N⁺(C₁₂H₂₅)(CH₃)₂, Q'^-.

The aryl radicals preferably denote phenyl, benzyl, naphthyl or anthryl groups.

Mention may in particular be made of the polymers having the following INCI names:

- Polyquaternium-24, such as the product Quatrisoft LM 200®, sold by Amerchol/Dow Chemical;

- PG-Hydroxyethylcellulose Cocodimonium Chloride, such as the product Crodacel QM®;

- PG-Hydroxyethylcellulose Lauryldimonium Chloride (C12 alkyl), such as the product Crodacel QL®; and

- PG-Hydroxyethylcellulose Stearyldimonium Chloride (C18 alkyl), such as the product Crodacel QS®, sold by Croda.

Mention may also be made of the hydroxyethylcelluloses of formula (Ib) in which R represents trimethylammonium halide and R' represents dimethyldodecylammonium halide; preferentially, R represents trimethylammonium chloride (CH₃)3N⁺-, Cl^- and R' represents dimethyldodecylammonium chloride (CH₃)₂(C₁₂H₂₅)N⁺-, Cl^-. This type of polymer is known under the INCI name Polyquaternium-67; as commercial products, mention may be made of the Softcat Polymer SL® polymers, such as SL-100, SL-60, SL-30 and SL-5, from Amerchol/Dow Chemical.

More particularly, the polymers of formula (Ib) are those of which the viscosity is between 2000 and 3000 cPs inclusive, preferentially between 2700 and 2800 cPs. Typically, Softcat Polymer SL-5 has a viscosity of 2500 cPs, Softcat Polymer SL-30 has a viscosity of 2700 cPs, Softcat Polymer SL-60 has a viscosity of 2700 cPs and Softcat Polymer SL-100 has a viscosity of 2800 cPs.

- (C) cationic polyvinyllactams, in particular those comprising:

-a) at least one monomer of vinyllactam or alkylvinyllactam type;

-b) at least one monomer of structure (Ic) or (IIc) below:

in which:

- X denotes an oxygen atom or an NR6 radical,

- R₁ and R₆ denote, independently of one another, a hydrogen atom or a linear or branched C₁-C₅ alkyl radical,

- R₂ denotes a linear or branched C₁-C₄ alkyl radical,

- R₃, R₄ and R₅ denote, independently of one another, a hydrogen atom, a linear or branched C₁-C₃₀ alkyl radical or a radical of formula (IIIc):

- Y, Y₁ and Y₂ denote, independently of one another, a linear or branched C₂-C₁₆ alkylene radical,

- R₇ denotes a hydrogen atom, or a linear or branched C₁-C₄ alkyl radical or a linear or branched C₁-C₄ hydroxyalkyl radical,

- R₈ denotes a hydrogen atom or a linear or branched C₁-C₃₀ alkyl radical,

- p, q and r denote, independently of one another, 0 or 1,

- m and n denote, independently of one another, an integer ranging from 0 to 100 inclusive,

- x denotes an integer ranging from 1 to 100 inclusive,

- Z denotes an anionic counterion of an organic or mineral acid, such as a halide, for instance chloride or bromide, or mesylate;

with the proviso that:

- at least one of the substituents R₃, R₄, R₅ or R₈ denotes a linear or branched C₉-C₃₀ alkyl radical,

- if m and/or n is other than zero, then q is equal to 1,

- if m = n = 0, then p or q is equal to 0.

The cationic poly(vinyllactam) polymers according to the invention may be crosslinked or non-crosslinked and may also be block polymers.

Preferably, the counterion Z^- of the monomers of formula (Ic) is chosen from halide ions, phosphate ions, the methosulfate ion and the tosylate ion.

Preferably, R₃, R₄ and R₅ denote, independently of one another, a hydrogen atom or a linear or branched C₁-C₃₀ alkyl radical.

More preferentially, the monomer b) is a monomer of formula (Ic) for which, preferentially, m and n are equal to 0.

The vinyllactam or alkylvinyllactam monomer is preferably a compound of structure (IVc):

in which:

- s denotes an integer ranging from 3 to 6,

- R₉ denotes a hydrogen atom or a linear or branched C₁-C₅ alkyl radical,

- R₁₀ denotes a hydrogen atom or a linear or branched C₁-C₅ alkyl radical,

with the proviso that at least one of the radicals R₉ and R₁₀ denotes a hydrogen atom.

Even more preferentially, the monomer (IVc) is vinylpyrrolidone.

The cationic poly(vinyllactam) polymers according to the invention may also contain one or more additional monomers, preferably cationic or non-ionic monomers.

As compounds that are particularly preferred, mention may be made of the following terpolymers comprising at least:

a) a monomer of formula (IVc),

b) a monomer of formula (Ic) in which p = 1, m = n = q = 0, R₃ and R₄ denote, independently of one another, a hydrogen atom or a C₁-C₅ alkyl radical and R₅ denotes a linear or branched C₉-C₂₄ alkyl radical, and

c) a monomer of formula (IIc) in which p = 1, m = n = q = 0, and R₃ and R₄ denote, independently of one another, a hydrogen atom or a linear or branched C₁-C₅ alkyl radical.

Even more preferentially, terpolymers comprising, by weight, 40% to 95% of monomer (a), 0.1% to 55% of monomer (c) and 0.25% to 50% of monomer (b) will be used. Such polymers are particularly described in patent application WO-00/68282.

As cationic poly(vinyllactam) polymers according to the invention, use is in particular made of:

- vinylpyrrolidone/dimethylaminopropylmethacrylamide/dodecyldimethylmethacrylamidopropylammonium tosylate terpolymers,

- vinylpyrrolidone/dimethylaminopropylmethacrylamide/cocoyldimethylmethacrylamidopropylammonium tosylate terpolymers,

- vinylpyrrolidone/dimethylaminopropylmethacrylamide/lauryldimethylmethacrylamidopropylammonium tosylate or chloride terpolymers.

The vinylpyrrolidone / dimethylaminopropylmethacrylamide / lauryldimethylmethylacrylamidopropylammonium chloride terpolymer is in particular sold by ISP under the names Styleze W10® and Styleze W20L® (INCI name: Polyquaternium-55).

The weight-average molecular mass (Mw) of the cationic poly(vinyllactam) polymers is preferably between 500 and 20 000 000, more particularly between 200 000 and 2 000 000 and preferentially between 400 000 and 800 000.

- (D) the cationic polymers obtained by polymerization of a mixture of monomers comprising one or more vinyl monomers substituted with one or more amino groups, one or more hydrophobic non-ionic vinyl monomers and one or more associative vinyl monomers, such as described in patent application WO 2004/024779.

Among these polymers, mention will more particularly be made of the products from the polymerization of a monomer mixture 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 mol of ethylene oxide units),

- a 30/5 polyethylene glycol/polypropylene glycol allyl ether,

- a hydroxy(C₂-C₆ alkyl) methacrylate, and

- an ethylene glycol dimethacrylate.

Such a polymer is, for example, the compound sold by Lubrizol under the name Carbopol Aqua CC® and which corresponds to the INCI name Polyacrylate-1 Crosspolymer.

Preferably, the cationic polymers that can be used in the context of the invention are chosen, alone or as a mixture, from:

- alkyldiallylamine or dialkyldiallylammonium cyclopolymers, and in particular homopolymers or copolymers of dimethyldiallylammonium salts (for example chloride),

- optionally crosslinked homopolymers or copolymers of methacryloyloxy(C₁-C₄)alkyltri(C₁-C₄)alkylammonium salts;

- celluloses and galactomannan gums that are cationic.

Mention may in particular be made of the polymers having the INCI name: Polyquaternium-6, Polyquaternium-7, Polyquaternium-37, Polyquaternium-10, Guar Hydroxypropyltrimonium Chloride, Hydroxypropyl Guar Hydroxypropyltrimonium Chloride, alone or in mixtures.

Better still, the cationic polymers that may be present in the composition A according to the invention are chosen from dimethyldiallylammonium halides, in particular chlorides (Polyquaternium-6).

Preferably, the composition A according to the invention comprises one or more cationic polymers, preferentially chosen from dimethyldiallylammonium halides, in particular chlorides (Polyquaternium-6).

The composition A used in step (i) according to the invention may comprise the cationic polymer(s) in a total amount of between 0.01% and 8% by weight, in particular from 0.05% to 5% by weight, preferentially from 0.1% to 3% by weight and even better still from 0.5% to 2% by weight, relative to the total weight of the composition.

In particular, the composition A used in step (i) according to the invention may comprise the cationic polymer(s) chosen from, alone or as a mixture:

- quaternary polymers of vinylpyrrolidone and of vinylimidazole;

in a total amount of between 0.01% and 8% by weight, in particular from 0.05% to 5% by weight, preferentially from 0.1% to 3% by weight and even better still from 0.5% to 2% by weight, relative to the total weight of the composition.

3/ Compounds of amino acid type

Advantageously, the composition A used in the context of step (i) according to the present invention may comprise one or more compounds of amino acid type.

For the purposes of the present invention, “compound of amino acid type” means an organic compound comprising one or more carboxylic acid and/or sulfonic acid functions and one or more amine functions, it being possible for the amine function(s) to be intracyclic, optionally in salt form; said amine function(s) being primary or secondary amine functions.

Preferably, the compound(s) of amino acid type are chosen from compounds of amino acid type comprising only one or more carboxylic acid functions (thus not comprising any sulfonic acid functions) and/or salts thereof. Said compounds are also called compounds of aminocarboxylic acid type and are particularly preferred.

Preferably, the composition A comprises one or more compounds of amino acid type chosen from the compounds corresponding to formula (I) below and/or salts thereof.

The compounds of amino acid type may thus correspond to formula (II):

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 ring members, preferably 5 ring members, it being possible for this ring to be optionally substituted with one or more groups chosen from hydroxyl or (C₁-C₄)alkyl;

- when p = 2, R represents a hydrogen atom or else a saturated, linear or branched, (C₁-C₁₂)alkyl, preferably (C₁-C₄)alkyl, group, optionally interrupted with one or more heteroatoms or groups chosen from –S–, –NH– or –C(NH)– and/or optionally substituted with one or more groups chosen from hydroxyl (-OH), amino (-NH₂), -SH, -COOH, -CONH₂ or –NH–C(NH)–NH₂ or a C₅-C₇ aryl group, in particular phenyl, itself optionally substituted with one or more OH.

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

Preferably, p = 2.

Preferably, when p = 2, R represents a hydrogen atom or a saturated, linear or branched, (C₁-C₄)alkyl group, optionally interrupted with a –S– heteroatom and/or optionally substituted with one or two groups chosen from hydroxyl, amino or –NH–C(NH)–NH₂.

Preferentially, p = 2 and R represents a hydrogen atom.

The compounds of amino acid type may also be a salt of a compound of formula (II).

These salts comprise salts with organic or mineral bases, for example the salts of alkali metals, for instance lithium, sodium or potassium salts; the salts of alkaline-earth metals, for instance magnesium or calcium salts, and zinc salts.

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

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-methionine, L-serine, L-arginine and L-lysine.

Preferably, the compound(s) of amino acid type according to the invention are chosen from glycine, arginine, tyrosine, methionine, serine, glutamic acid, lysine, salts thereof (particularly alkali metal, alkaline-earth metal or zinc salts) and mixtures thereof.

Preferably, the compound(s) of amino acid type according to the invention are chosen from glycine, arginine, tyrosine, glutamic acid, serine, salts thereof and mixtures thereof.

Better still, the compound of amino acid type is chosen from glycine, salts thereof (particularly alkali metal, alkaline-earth metal or zinc salts) and mixtures thereof.

As glycine salts according to the present invention, mention may be made of sodium glycinate, zinc glycinate, calcium glycinate, magnesium glycinate, manganese glycinate and potassium glycinate, preferably sodium glycinate and potassium glycinate.

Preferably, the compound of amino acid type is glycine.

According to a preferred embodiment of the invention, the composition A may comprise at least 2 different compounds of amino acid type, better still at least 3 different compounds of amino acid type.

In particular, the composition A according to the invention may comprise at least 2 different compounds corresponding to formula (II) and/or salts thereof, better still at least 3 different compounds corresponding to formula (II) and/or salts thereof.

Preferably, the composition A according to the invention may comprise at least 2 different compounds chosen from glycine, arginine, tyrosine, glutamic acid, serine, salts thereof and mixtures thereof; better still at least 3 different compounds chosen from glycine, arginine, tyrosine, glutamic acid, serine, salts thereof and mixtures thereof.

Even better still, the composition A according to the invention may comprise:

- glycine and/or a salt thereof, and

- glutamic acid and/or a salt thereof,

- optionally arginine and/or a salt thereof,

- optionally serine and/or a salt thereof.

Very preferentially, the composition according to the invention may comprise glycine and/or a salt thereof, glutamic acid and/or a salt thereof, arginine and/or a salt thereof, and serine and/or a salt thereof.

The total content of compound(s) of amino acid type present in the composition A according to the invention is at least 0.5% by weight, relative to the total weight of the composition. This content may range from 0.5% to 10% by weight, in particular from 0.8% to 8% by weight, better still from 1% to 7% by weight and even better still from 1.3% to 5% by weight, relative to the total weight of the composition.

In particular, the total content of compound(s) of amino acid type of formula (II) in the composition A according to the invention is at least 0.5% by weight relative to the total weight of the composition. This content may range from 0.5% to 10% by weight, in particular from 0.8% to 8% by weight, better still from 1% to 7% by weight and even better still from 1.3% to 5% by weight, relative to the total weight of the composition.

Better still, the total content of compound(s) of amino acid type chosen from glycine, serine, glutamic acid, arginine, tyrosine, salts thereof and mixtures thereof, in the composition according to the invention, is at least 0.5% by weight relative to the total weight of the composition. This content may range from 0.5% to 10% by weight, in particular from 0.8% to 8% by weight, better still from 1% to 7% by weight and even better still from 1.3% to 5% by weight, relative to the total weight of the composition.

Most particularly, the total content of compound(s) of amino acid type chosen from glycine, salts thereof and mixtures thereof, in the composition according to the invention is at least 0.5% by weight relative to the total weight of the composition. This content may range from 0.5% to 10% by weight, in particular from 0.7% to 8% by weight, better still from 0.8% to 5% by weight, relative to the total weight of the composition.

4/ Hydroxy(poly)carboxylic acids

The composition according to the invention also comprises at least 0.5% by weight of one or more hydroxylated polycarboxylic acids, comprising 2 to 8 carbon atoms, and/or salts thereof.

These polyacids are different from the compounds of amino acid type described above.

Said hydroxylated polycarboxylic acids comprise several, in particular at least 2, COOH groups (in acid or salified form), better still 2 or 3 COOH groups (in acid or salified form). This is referred to as hydroxylated polycarboxylic acids.

The hydroxylated polycarboxylic acids according to the invention also comprise at least one OH group, but may comprise several of them, in particular from 2 to 3 OH groups.

Preferably, said hydroxylated polycarboxylic acids comprise in total from 4 to 6 carbon atoms.

The hydrocarbon chain of said hydroxylated polycarboxylic acids may be linear or branched, and saturated or unsaturated, and is preferably saturated and linear.

The salts of the polyacids comprise the salts with organic or mineral bases, for example the salts of alkali metals, such as the lithium, sodium or potassium salts; the salts of alkaline-earth metals, such as the magnesium or calcium salts, and the zinc salts. The alkali metal or alkaline-earth metal salts are preferred and in particular the sodium salts.

Advantageously, the hydroxylated polycarboxylic acids and/or salts thereof comprise in total from four to six carbon atoms, from one to three OH groups and from two to three COOH groups (in acid or salified form).

Preferably, the hydroxylated polycarboxylic acids or salts thereof are chosen from tartaric acid or citric acid, and salts thereof, in particular alkali metal or alkaline-earth metal salts thereof; most particularly sodium citrate and/or sodium tartrate; even better still citric acid or salts thereof, in particular of alkali or alkaline-earth metal salts thereof, such as sodium citrate.

Preferably, the composition A according to the invention comprises one or more hydroxylated polycarboxylic acids chosen from tartaric acid or citric acid, and salts thereof, in particular alkali metal or alkaline-earth metal salts thereof, such as sodium citrate and/or sodium tartrate; even better still chosen from citric acid and sodium citrate, and mixtures thereof.

The total content of hydroxylated polycarboxylic acids comprising in total 2 to 8 carbon atoms, and/or salts thereof, present in the composition A according to the invention is at least 0.5% by weight, in particular at least 1% by weight, relative to the total weight of the composition. This content may preferably range from 0.5% to 12% by weight, better still from 1% to 10% by weight, even better still from 1.5% to 8% by weight or even from 2% to 7% by weight, relative to the total weight of the composition.

In particular, the total content of hydroxylated polycarboxylic acids comprising in total from 4 to 6 carbon atoms, from 1 to 3 OH groups and 2 or 3 COOH groups, or salts thereof, present in the composition according to the invention may range from 0.5% to 12% by weight, better still from 1% to 10% by weight, even better still from 1.5% to 8% by weight, or even from 2% to 7% by weight, relative to the total weight of the composition.

Most particularly, the total content of hydroxylated polycarboxylic acids chosen from tartaric acid or citric acid, and salts thereof, in particular alkali metal or alkaline-earth metal salts thereof, in the composition according to the invention may range from 0.5% to 12% by weight, better still from 1% to 10% by weight, even better still from 1.5% to 8% by weight, or even from 2% to 7% by weight, relative to the total weight of the composition.

Even better still, the content of citric acid and/or salts thereof in the composition according to the invention may range from 0.5% to 12% by weight, better still from 1% to 10% by weight, even better still from 1.5% to 8% by weight, or even from 2% to 7% by weight, relative to the total weight of the composition.

5/ Other ingredients

The composition A may comprise a cosmetically acceptable medium, that is to say a medium compatible with topical application to keratin fibres, in particular the hair.

The composition A according to the invention may comprise water or a mixture of water and one or more cosmetically acceptable solvents chosen from C₁-C₄ alcohols, such as ethanol, isopropanol, tert-butanol or n-butanol; polyols such as glycerol, propylene glycol, hexylene glycol and polyethylene glycols; and mixtures thereof.

Preferably, the composition A according to the invention comprises a total water content of between 50% and 98%, preferentially between 60% and 95% by weight, even better still between 65% and 90% by weight, or even between 70% and 85% by weight, relative to the total weight of the composition.

The pH of the composition A according to the invention generally ranges from 3 to 8, preferentially from 3.5 to 7, and better still from 4 to 6, or even from 4.5 to 5.5.

The cosmetic composition A may further comprise at least one standard cosmetic ingredient, in particular chosen from plant, mineral, animal or synthetic oils; liquid fatty alcohols; liquid fatty esters; solid fatty substances and in particular waxes, solid fatty esters, solid alcohols; anionic, cationic, amphoteric and non-ionic surfactants; sunscreens; moisturizers; anti-dandruff agents; antioxidants; nacreous agents and opacifiers; plasticizers or coalescence agents; preserving agents; sequestrants (EDTA and salts thereof); dyestuffs. Advantageously, it further comprises at least one non-ionic surfactant. The composition can, of course, comprise several cosmetic ingredients appearing in the above list. A person skilled in the art will take care to choose the ingredients participating in the composition, and also their amounts, in such a way that the advantageous properties of the composition according to the invention are not, or not substantially, detrimentally affected by the envisaged addition.

B/ Washing step (ii)

The cosmetic treatment process, in particular hair treatment process, according to the invention also comprises a step (ii) referred to as step of washing said keratin fibres, comprising the application of a washing cosmetic composition B comprising one or more anionic surfactants and/or one or more amphoteric surfactants.

1/ Anionic surfactants

The washing cosmetic composition B can comprise one or more anionic surfactants.

The term “anionic surfactant” means a surfactant including, as ionic or ionizable groups, only anionic groups.

In the present description, a species is termed as being “anionic” when it bears at least one permanent negative charge or when it can be ionized to a negatively charged species, under the conditions of use of the composition of the invention (for example the medium or the pH) and not comprising any cationic charge.

The anionic surfactants may be sulfate, sulfonate and/or carboxylic (or carboxylate) surfactants. Needless to say, a mixture of these surfactants may be used.

It is understood in the present description that:

- the carboxylate anionic surfactants comprise at least one carboxylic or carboxylate function (-COOH or -COO^-) and may optionally also comprise one or more sulfate and/or sulfonate functions;

- the sulfonate anionic surfactants comprise at least one sulfonate function (-SO₃H or -SO₃ ^–) and may optionally also comprise one or more sulfate functions, but do not comprise any carboxylate functions; and

- the sulfate anionic surfactants comprise at least one sulfate function but do not comprise any carboxylate or sulfonate functions.

The carboxylic anionic surfactants that may be used thus include at least one carboxylic or carboxylate function (-COOH or -COO^-).

They may be chosen from the following compounds: acylglycinates, acyllactylates, acylsarcosinates, acylglutamates; alkyl ether carboxylic acids, alkyl(C₆-₃₀ aryl)ether carboxylic acids, alkyl-D-galactosideuronic acids, alkylamido ether carboxylic acids; and also the salts of these compounds; the alkyl and/or acyl groups of these compounds including from 6 to 30 carbon atoms, in particular from 12 to 28, even better still from 14 to 24 or even from 16 to 22 carbon atoms; the aryl group preferably denoting a phenyl or benzyl group; it being possible for these compounds to be polyoxyalkylenated, in particular polyoxyethylenated, and then preferably including from 1 to 50 ethylene oxide units, better still from 2 to 10 ethylene oxide units.

Use may also be made of the C₆-C₂₄ alkyl monoesters of polyglycoside-polycarboxylic acids, such as C₆-C₂₄ alkyl polyglycoside-citrates, C₆-C₂₄ alkyl polyglycoside-tartrates and C₆-C₂₄ alkyl polyglycoside-sulfosuccinates, and salts thereof.

Mention may very particularly be made, among the above carboxylic surfactants, of polyoxyalkylenated alkyl(amido) ether carboxylic acids and salts thereof, in particular those comprising from 2 to 50 alkylene oxide groups, in particular ethylene oxide groups, such as the compounds provided by Kao under the Akypo names.

The polyoxyalkylenated alkyl(amido) ether carboxylic acids capable of being used are preferably chosen from those of formula (1):

R_1’–(OC₂H₄)_n’–OCH₂COOA (1)

in which:

- R_1' represents a linear or branched C₆-C₂₄ alkyl or alkenyl radical, a (C₈-C₉)alkylphenyl radical, an R_2’CONH-CH₂-CH₂- radical with R_2’ denoting a linear or branched C₉-C₂₁ alkyl or alkenyl radical; preferably R_1’ is a C₈-C₂₀, preferably C₈-C₁₈, alkyl radical;

- n’ is an integer or decimal number (average value) ranging from 2 to 24 and preferably from 2 to 10,

- A denotes H, ammonium, Na, K, Li, Mg or a monoethanolamine or triethanolamine residue.

It is also possible to use mixtures of compounds of formula (1), in particular mixtures of compounds containing different R_1’ groups.

The polyoxyalkylenated alkyl(amido) ether carboxylic acids that are particularly preferred are those of formula (1) in which:

- R_1' denotes a linear or branched C₈-C₂₂, in particular C₁₀-C₁₆, or even C₁₂-C₁₄, alkyl radical, or else a (C₈-C₉)alkylphenyl radical;

- A denotes a hydrogen or sodium atom, and

- n’ ranges from 2 to 20, preferably from 2 to 10.

More preferentially still, use is made of compounds of formula (1) in which R_1' denotes a C₁₂-C₁₄ alkyl radical or cocoyl, oleyl, nonylphenyl or octylphenyl radical, A denotes a hydrogen or sodium atom and n’ ranges from 2 to 10.

Among the commercial products that may preferably be used are the products sold by Kao under the names:

Akypo® NP 70 (R₁ = nonylphenyl, n = 7, A = H)

Akypo® NP 40 (R₁ = nonylphenyl, n = 4, A = H)

Akypo® OP 40 (R₁ = octylphenyl, n = 4, A = H)

Akypo® OP 80 (R₁ = octylphenyl, n = 8, A = H)

Akypo® OP 190 (R₁ = octylphenyl, n = 19, A = H)

Akypo® RLM 38 (R₁ = (C₁₂-C₁₄)alkyl, n = 4, A = H)

Akypo® RLM 38 NV (R₁ = (C₁₂-C₁₄)alkyl, n = 4, A = Na)

Akypo® RLM 45 CA (R₁ = (C₁₂-C₁₄)alkyl, n = 4.5, A = H)

Akypo® RLM 45 NV (R₁ = (C₁₂-C₁₄)alkyl, n = 4.5, A = Na)

Akypo® RLM 100 (R₁ = (C₁₂-C₁₄)alkyl, n = 10, A = H)

Akypo® RLM 100 NV (R₁ = (C₁₂-C₁₄)alkyl, n = 10, A = Na)

Akypo® RLM 130 (R₁ = (C₁₂-C₁₄)alkyl, n = 13, A = H)

Akypo® RLM 160 NV (R₁ = (C₁₂-C₁₄)alkyl, n = 16, A = Na),

or by Sandoz under the names:

Sandopan DTC-Acid (R₁ = (C₁₃)alkyl, n = 6, A = H)

Sandopan DTC (R₁ = (C₁₃)alkyl, n = 6, A = Na)

Sandopan LS 24 (R₁ = (C₁₂-C₁₄)alkyl, n = 12, A = Na)

Sandopan JA 36 (R₁ = (C₁₃)alkyl, n = 18, A = H),

and more particularly the products sold under the following names:

Akypo® RLM 45 (INCI: Laureth-5 carboxylic acid)

Akypo® RLM 100

Akypo® RLM 38.

Preferentially, the carboxylic anionic surfactants are chosen, alone or as a mixture, from:

- in particular C₆-C₂₄ or even C₁₂-C₂₀ acylglutamates, such as stearoylglutamates, and in particular disodium stearoylglutamate;

- in particular C₆-C₂₄ or even C₁₂-C₂₀ acylsarcosinates, such as palmitoylsarcosinates, and in particular sodium palmitoylsarcosinate;

- in particular C₁₂-C₂₈ or even C₁₄-C₂₄ acyllactylates, such as behenoyllactylates, and in particular sodium behenoyllactylate;

- C₆-C₂₄ and in particular C₁₂-C₂₀ acylglycinates;

- (C₆-C₂₄)alkyl ether carboxylates, and particularly (C₁₂-C₂₀)alkyl ether carboxylates; in particular those including from 2 to 50 ethylene oxide groups;

- polyoxyalkylenated (C₆-C₂₄)alkylamido ether carboxylic acids, in particular those including from 2 to 50 ethylene oxide groups;

in particular in acid form or in the form of alkali metal or alkaline-earth metal, ammonium or amino alcohol salts.

Preferably, the composition comprises one or more acylsarcosinates, in particular C₆-C₂₄, or even C₁₂-C₂₀ acylsarcosinates, such as palmitoylsarcosinates and lauroylsarcosinates, and also salts thereof; and in particular sodium palmitoylsarcosinate and/or sodium lauroylsarcosinate.

The sulfonate anionic surfactants that may be used include at least one sulfonate function (-SO₃H or -SO₃ ^–). They may be chosen from the following compounds: alkylsulfonates, alkyl ether sulfonates, alkylamidesulfonates, alkylarylsulfonates, α-olefin sulfonates, paraffin sulfonates, alkyl sulfosuccinates, alkyl ether sulfosuccinates, alkylamidesulfosuccinates, alkylsulfoacetates, N-acyltaurates, acylisethionates; alkylsulfolaurates; and also the salts of these compounds;

the alkyl groups of these compounds including from 6 to 30 carbon atoms, particularly from 12 to 28, even better still from 14 to 24 or even from 16 to 22 carbon atoms; the aryl group preferably denoting a phenyl or benzyl group;

it being possible for these compounds to be polyoxyalkylenated, particularly polyoxyethylenated, and then preferably including from 1 to 50 ethylene oxide units and better still from 2 to 10 ethylene oxide units.

Preferentially, the sulfonate anionic surfactants are chosen, alone or as a mixture, from:

- C₆-C₂₄ and in particular C₁₂-C₂₀ olefin sulfonates,

- C₆-C₂₄ and in particular C₁₂-C₂₀ alkylsulfosuccinates, in particular laurylsulfosuccinates;

- C₆-C₂₄ and in particular C₁₂-C₂₀ alkyl ether sulfosuccinates;

- (C₆-C₂₄)acylisethionates and preferably (C₁₂-C₁₈)acylisethionates;

- C₆-C₂₄ alkyl sulfoacetates, in particular C₁₂-C₂₀ alkyl sulfoacetates,

in particular in the form of alkali metal or alkaline-earth metal, ammonium or amino alcohol salts.

The sulfate anionic surfactants that may be used include at least one sulfate function (-OSO₃H or -OSO₃ ^-).

They may be chosen from the following compounds: alkyl sulfates, alkyl ether sulfates, alkylamido ether sulfates, alkylaryl polyether sulfates, monoglyceride sulfates; and the salts of these compounds;

Preferentially, the sulfate anionic surfactants are chosen, alone or as a mixture, from:

- in particular C₆-C₂₄ or even C₁₂-C₂₀ alkyl sulfates, and

- in particular C₆-C₂₄ or even C₁₂-C₂₀ alkyl ether sulfates, preferably comprising from 2 to 20 ethylene oxide units;

When the anionic surfactant is in salt form, said salt may be chosen from alkali metal salts, such as the sodium or potassium salt, ammonium salts, amine salts and in particular amino alcohol salts, and alkaline-earth metal salts, such as the magnesium salt.

Examples of amino alcohol salts that may be mentioned include monoethanolamine, diethanolamine and triethanolamine salts, monoisopropanolamine, diisopropanolamine or triisopropanolamine salts, 2-amino-2-methyl-1-propanol salts, 2-amino-2-methyl-1,3-propanediol salts and tris(hydroxymethyl)aminomethane salts.

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

Preferentially, the anionic surfactants are chosen, alone or as a mixture, from:

- C₆-C₂₄ and in particular C₁₂-C₂₀ alkyl sulfates;

- C₆-C₂₄ and in particular C₁₂-C₂₀ alkyl ether sulfates; preferably comprising from 2 to 20 ethylene oxide units;

- C₆-C₂₄ and in particular C₁₂-C₂₀ olefin sulfonates,

- C₆-C₂₄ and in particular C₁₂-C₂₀ alkyl ether sulfosuccinates;

- C₆-C₂₄ acylsarcosinates, in particular C₁₂-C₂₀ acylsarcosinates; in particular palmitoylsarcosinates and lauroylsarcosinates;

- (C₆-C₂₄)alkyl ether carboxylates, preferably (C₁₂-C₂₀)alkyl ether carboxylates; in particular those including from 2 to 50 ethylene oxide groups;

- polyoxyalkylenated (C₆-C₂₄)alkylamido ether carboxylic acids and salts thereof, in particular those including from 2 to 50 alkylene oxide and in particular ethylene oxide groups;

- C₆-C₂₄ and in particular C₁₂-C₂₀ acylglutamates;

- C₆-C₂₄ and in particular C₁₂-C₂₀ acylglycinates;

Preferentially, the composition B comprises one or more anionic sulfonate surfactants and/or carboxylic (or carboxylate) surfactants, preferably chosen from C₆-C₂₄, especially C₁₂-C₂₀, alkyl ether sulfosuccinates, (C₆-C₂₄)acylisethionates, preferably (C₁₂-C₁₈)acylisethionates, C₆-C₂₄, especially C₁₂-C₂₀, acylsarcosinates, C₆-C₂₄, especially C₁₂-C₂₀, alkyl sulfoacetates, and mixtures thereof, and also salts thereof, particularly in the form of alkali metal or alkaline-earth metal, ammonium or amino alcohol salts.

Preferably, the composition B does not comprise any anionic sulfate surfactant (0%).

The anionic surfactant(s) are preferably present in the washing composition B according to the invention in a total amount ranging from 2% to 40% by weight, in particular from 5% to 35% by weight, better still from 10% to 30% by weight, even better still from 15% to 25% by weight, relative to the total weight of the composition.

The anionic surfactant(s) chosen from sulfonate surfactants and/or carboxylic (or carboxylate) surfactants are preferably present in the washing composition B according to the invention in a total amount ranging from 2% to 40% by weight, in particular from 5% to 35% by weight, better still from 10% to 30% by weight, even better still from 15% to 25% by weight, relative to the total weight of the composition

2/ Amphoteric surfactants

The washing composition B may also comprise one or more amphoteric surfactants. The term “amphoteric surfactant” is understood to mean amphoteric or zwiterrionic surfactant.

In particular, the amphoteric surfactant(s) are non-silicone. They may in particular be optionally quaternized secondary or tertiary aliphatic amine derivatives, in which the aliphatic group is a linear or branched chain including from 8 to 22 carbon atoms, said amine derivatives containing at least one anionic group, for instance a carboxylate, sulfonate, sulfate, phosphate or phosphonate group.

Mention may in particular be made of (C₈-C₂₀)alkylbetaines, (C₈-C₂₀)alkylsulfobetaines, (C₈-C₂₀)alkylamido(C₃-C₈)alkylbetaines and (C₈-C₂₀)alkylamido(C₆-C₈)alkylsulfobetaines.

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

R_a-CONHCH₂CH₂-N⁺(R_b)(R_c)-CH₂COO^-, M⁺, X^- (II)

in which:

- R_a represents a C₁₀ to C₃₀ alkyl or alkenyl group derived from an acid R_aCOOH preferably present in hydrolysed coconut kernel oil, or a heptyl, nonyl or undecyl group;

- R_b represents a β-hydroxyethyl group; and

- R_c represents a carboxymethyl group;

- M⁺ represents a cationic counterion derived from an alkali metal or alkaline-earth metal, such as sodium, an ammonium ion or an ion derived from an organic amine, and

- X^- represents an organic or inorganic anionic counterion, such as that chosen from halides, acetates, phosphates, nitrates, (C₁-C₄)alkyl sulfates, (C₁-C₄)alkyl- or (C₁-C₄)alkylaryl-sulfonates, in particular methyl sulfate and ethyl sulfate; or alternatively M⁺ and X^- are absent;

R_a’-CONHCH₂CH₂-N(B)(B’) (III)

in which:

- B represents the group -CH₂CH₂OX’;

- B’ represents the group -(CH₂)_zY’, with z = 1 or 2;

- X’ represents the group -CH₂COOH, -CH₂-COOZ’, -CH₂CH₂COOH or CH₂CH₂-COOZ’, or a hydrogen atom;

- Y’ represents the group -COOH, -COOZ’ or -CH₂CH(OH)SO₃H or the group CH₂CH(OH)SO₃-Z’;

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

- R_a’ represents a C₁₀ to C₃₀ alkyl or alkenyl group of an acid R_a’-COOH which is preferably present in hydrolysed linseed oil or coconut kernel oil, an alkyl group, particularly a C₁₇ alkyl group, and its iso form, or an unsaturated C₁₇ group.

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

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

Use may also be made of compounds of formula (IV):

R_a’’-NHCH(Y’’)-(CH₂)_nCONH(CH₂)_n’-N(R_d)(R_e) (IV)

in which:

- Y’’ represents the group -COOH, -COOZ’’ or -CH₂CH(OH)SO₃H or the group CH₂CH(OH)SO₃-Z’’;

- R_d and R_e, independently of one another, represent a C₁ to C₄ alkyl or hydroxyalkyl radical;

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

- R_a'' represents a C₁₀ to C₃₀ alkyl or alkenyl group of an acid R_a''-COOH which is preferably present in hydrolysed linseed oil or coconut kernel oil;

- n and n’ denote, independently of one another, an integer ranging from 1 to 3.

Among the compounds of formula (II), mention may be made of the compound classified in the CTFA dictionary under the name sodium diethylaminopropyl cocoaspartamide and sold by Chimex under the name Chimexane HB.

These compounds may be used alone or as mixtures.

Among the amphoteric surfactants, use is preferably made of (C₈-C₂₀)alkylbetaines such as cocoylbetaine, (C₈-C₂₀)alkylamido(C₃-C₈)alkylbetaines such as cocamidopropylbetaine, and mixtures thereof, and the compounds of formula (IV) such as the sodium salt of diethylaminopropyl laurylaminosuccinamate (INCI name: sodium diethylaminopropyl cocoaspartamide).

Preferentially, the amphoteric surfactants are chosen from (C₈-C₂₀)alkylbetaines such as cocobetaine, (C₈-C₂₀)alkylamido(C₃-C₈)alkylbetaines such as cocamidopropylbetaine, and mixtures thereof; better still from (C₈-C₂₀)alkylamido(C₃-C₈)alkylbetaines such as cocamidopropylbetaine.

Preferably, the amphoteric surfactant(s) are present in the composition B in a total content ranging from 0.1% to 20% by weight, preferentially in a content ranging from 0.5% to 10% by weight and even better still from 1% to 5% by weight, relative to the total weight of the composition B.

Preferably, the amphoteric surfactant(s) chosen from (C₈-C₂₀)alkylbetaines such as cocobetaine, (C₈-C₂₀)alkylamido(C₃-C₈)alkylbetaines such as cocamidopropylbetaine, and mixtures thereof are present in the composition B in a total content ranging from 0.1% to 20% by weight, preferentially in a content ranging from 0.5% to 10% by weight, even better still from 1% to 5% by weight, relative to the total weight of the composition B.

Preferably, the composition B used in step (ii) of the process according to the invention comprises one or more anionic surfactants and one or more amphoteric surfactants.

3/ Non-ionic surfactants

The cosmetic composition B may optionally comprise one or more non-ionic surfactants, in particular such as those described in "Handbook of surfactants" by M. R. Porter, published by Blackie & Son (Glasgow and London), 1991, pages 116-178.

Examples of non-ionic surfactants that may be mentioned include the following compounds, alone or as a mixture:

- oxyalkylenated (C₈-C₂₄)alkylphenols;

- saturated or unsaturated, linear or branched, oxyalkylenated or glycerolated C₈-C₄₀ alcohols, preferably including one or two fatty chains;

- saturated or unsaturated, linear or branched, oxyalkylenated C₈ to C₃₀ fatty acid amides;

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

- preferably oxyethylenated esters of saturated or unsaturated, linear or branched, C₈ to C₃₀ acids and of sorbitol;

- fatty acid esters of sucrose;

- (C₈-C₃₀)alkyl (poly)glucosides, (C₈-C₃₀)alkenyl (poly)glucosides, which are optionally oxyalkylenated and which comprise from 1 to 15 glucose units, (C₈-C₃₀)alkyl (poly)glucoside esters;

- saturated or unsaturated plant oils which are oxyethylenated;

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

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

- amine oxides.

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

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

Advantageously, the non-ionic surfactants according to the invention do not comprise oxypropylene units.

Preferably, they comprise a number of moles of ethylene oxide ranging from 1 to 250, in particular from 2 to 100, better still from 2 to 50.

Use is preferably made, by way of example of glycerolated non-ionic surfactants, of mono- or polyglycerolated C₈ to C₄₀ alcohols comprising from 1 to 50 mol of glycerol, preferably from 1 to 10 mol of glycerol.

Mention may be made, as examples of compounds of this type, of lauryl alcohol having 4 mol of glycerol (INCI name: Polyglyceryl-4 Lauryl Ether), lauryl alcohol containing 1.5 mol of glycerol, oleyl alcohol containing 4 mol of glycerol (INCI name: Polyglyceryl-4 Oleyl Ether), oleyl alcohol containing 2 mol of glycerol (INCI name: Polyglyceryl-2 Oleyl Ether), cetearyl alcohol containing 2 mol of glycerol, cetearyl alcohol containing 6 mol of glycerol, oleocetyl alcohol containing 6 mol of glycerol, and octadecanol containing 6 mol of glycerol.

Use is more preferably made, among the glycerolated alcohols, of the C₈ to C₁₀ alcohol having 1 mol of glycerol, the C₁₀ to C₁₂ alcohol having 1 mol of glycerol and the C₁₂ alcohol having 1.5 mol of glycerol.

The non-ionic surfactant(s) capable of being used in the washing composition according to the invention are preferentially chosen, alone or as a mixture, from:

- saturated or unsaturated, linear or branched, oxyethylenated C₈ to C₄₀ alcohols comprising from 1 to 100 mol of ethylene oxide, preferably from 2 to 50 and more particularly from 2 to 40 mol of ethylene oxide and preferably including one or two fatty chains;

- saturated or unsaturated oxyethylenated plant oils comprising from 1 to 100 and preferably from 2 to 50 mol of ethylene oxide;

- (C₈-C₃₀)alkyl (poly)glucosides which are optionally oxyalkylenated, preferably with from 0 to 10 mol of ethylene oxide, and which comprise from 1 to 15 glucose units;

- mono- or polyglycerolated C₈ to C₄₀ alcohols comprising from 1 to 50 mol of glycerol, preferably from 1 to 10 mol of glycerol;

More preferentially, the non-ionic surfactant(s) are chosen, alone or as a mixture, from:

- saturated or unsaturated, linear or branched, oxyethylenated C₈ to C₄₀ alcohols comprising from 1 to 100 mol of ethylene oxide, preferably from 2 to 50 mol of ethylene oxide and more particularly from 2 to 40 mol of ethylene oxide and comprising one or two fatty chains, in particular at least one C₈-C₂₀, in particular C₁₀-C₁₈, alkyl chain;

- preferably oxyethylenated esters of saturated or unsaturated, linear or branched, C₈ to C₃₀ acids and of sorbitol, and

- (C₈-C₃₀)alkyl(poly)glucosides, which are optionally oxyalkylenated, preferably comprising from 1 to 10 mol of ethylene oxide and comprising 1 to 15 glucose units.

In particular, the washing composition B can comprise one or more non-ionic surfactants of alkyl (poly)glycosides type of general formula:

R₁O-(R₂O)_t-(G)_v

in which:

- R₁ represents a linear or branched alkyl or alkenyl radical comprising from 6 to 24 carbon atoms, in particular from 8 to 18 carbon atoms, or an alkylphenyl radical, the linear or branched alkyl radical of which comprises from 6 to 24 carbon atoms, in particular from 8 to 18 carbon atoms; preferably a saturated or unsaturated and linear or branched alkyl radical comprising from 8 to 18 carbon atoms;

- R₂ represents an alkylene radical including 2 to 4 carbon atoms;

- G represents a sugar unit comprising from 5 to 6 carbon atoms, preferably glucose, fructose or galactose, better still glucose;

- t denotes a value ranging from 0 to 10, preferably from 0 to 4, better still from 0 to 3, even better still 0;

- v denotes a value ranging from 1 to 15, preferably from 1 to 4, the mean degree of polymerization (v) more particularly being of between 1 and 2.

The glucoside bonds between the sugar units are generally of 1-6 or 1-4 type, preferably of 1-4 type.

Preferably, the alkyl (poly)glycoside surfactant is an alkyl (poly)glucoside surfactant.

Preferably, the washing composition B comprises the non-ionic surfactant(s), when they are present, in a total content ranging from 0.05% to 15% by weight, preferably from 0.1% to 10% by weight, preferentially from 0.2% to 5% by weight, relative to the total weight of the washing composition.

4/ Other ingredients

The washing composition B may comprise water or a mixture of water and one or more cosmetically acceptable solvents chosen from C₁-C₄ alcohols, such as ethanol, isopropanol, tert-butanol or n-butanol; polyols such as glycerol, propylene glycol and polyethylene glycols; and mixtures thereof.

Preferably, the washing composition B according to the invention has a total water content of between 20% and 95% by weight, preferably between 30% and 90% by weight, preferentially between 40% and 85% by weight and better still between 50% and 80% by weight, relative to the total weight of the composition.

The pH of the washing composition according to the invention generally ranges from 3 to 9, preferably from 3.5 to 7, preferentially from 4 to 6 and better still from 5 to 6.

The cleansing cosmetic composition according to the invention may also comprise at least one usual cosmetic ingredient, chosen in particular from polymeric or non-polymeric conditioning agents; mention may be made in particular of organomodified or non-organomodified silicones, such as aminated silicones; plant, mineral or synthetic oils; liquid fatty alcohols; liquid fatty esters; solid fatty substances and in particular waxes, solid fatty esters, solid alcohols, ceramides; sunscreens; moisturizers; anti-dandruff agents, antioxidants; nacreous agents and opacifiers; plasticizers or coalescence agents; preserving agents; sequestering agents (EDTA and salts thereof); dyestuffs. The composition can, of course, comprise several cosmetic ingredients appearing in the above list. A person skilled in the art will take care to choose the ingredients participating in the composition, and also their amounts, in such a way that the advantageous properties of the composition according to the invention are not, or not substantially, detrimentally affected by the envisaged addition.

C/ Step (iii) of applying a composition C

The cosmetic treatment process, in particular hair treatment process, according to the invention also comprises a step (iii) of applying to said keratin fibres a cosmetic composition C comprising one or more compounds of amino acid type and one or more hydroxylated (poly)carboxylic acids comprising 2 to 8 carbon atoms, and/or salts thereof.

1/ Compounds of amino acid type

The composition C used in the context of step (iii) according to the present invention comprises one or more compounds of amino acid type.

Preferably, the composition C comprises one or more compounds of amino acid type chosen from the compounds corresponding to formula (I) below and/or salts thereof.

The compounds of amino acid type may thus correspond to formula (II):

in which p is an integer equal to 1 or 2, it being understood that:

Preferably, p = 2.

Preferentially, p = 2 and R represents a hydrogen atom.

Preferably, the compound of amino acid type is glycine.

According to a preferred embodiment of the invention, the composition C may comprise at least 2 different compounds of amino acid type, better still at least 3 different compounds of amino acid type.

In particular, the composition C according to the invention may comprise at least 2 different compounds corresponding to formula (II) and/or salts thereof, better still at least 3 different compounds corresponding to formula (II) and/or salts thereof.

Preferably, the composition C according to the invention may comprise at least 2 different compounds chosen from glycine, arginine, tyrosine, glutamic acid, serine, salts thereof and mixtures thereof; better still at least 3 different compounds chosen from glycine, arginine, tyrosine, glutamic acid, serine, salts thereof and mixtures thereof.

Even better still, the composition C according to the invention may comprise:

- glycine and/or a salt thereof, and

- glutamic acid and/or a salt thereof,

- optionally arginine and/or a salt thereof,

- optionally serine and/or a salt thereof.

The total content of compound(s) of amino acid type present in the composition C according to the invention is at least 0.5% by weight, relative to the total weight of the composition. This content may range from 0.5% to 12% by weight, in particular from 1% to 10% by weight, better still from 2% to 8% by weight and even better still from 3% to 7% by weight, relative to the total weight of the composition.

In particular, the total content of compound(s) of amino acid type of formula (II) in the composition C according to the invention is at least 0.5% by weight relative to the total weight of the composition. This content may range from 0.5% to 12% by weight, in particular from 1% to 10% by weight, better still from 2% to 8% by weight and even better still from 3% to 7% by weight, relative to the total weight of the composition.

Better still, the total content of compound(s) of amino acid type chosen from glycine, methionine, serine, glutamic acid, arginine, lysine, salts thereof and mixtures thereof, in the composition C according to the invention, is at least 0.5% by weight relative to the total weight of the composition. This content may range from 0.5% to 12% by weight, in particular from 1% to 10% by weight, better still from 2% to 8% by weight and even better still from 3% to 7% by weight, relative to the total weight of the composition.

Most particularly, the total content of compound(s) of amino acid type chosen from glycine, salts thereof and mixtures thereof, in the composition C according to the invention is at least 0.5% by weight relative to the total weight of the composition. This content may range from 0.5% to 12% by weight, in particular from 1% to 10% by weight, better still from 2% to 8% by weight and even better still from 3% to 7% by weight, relative to the total weight of the composition.

2/ Hydroxy(poly)carboxylic acids

The composition C according to the invention also comprises one or more hydroxylated (poly)carboxylic acids comprising 2 to 8 carbon atoms, and/or salts thereof.

These (poly)acids are different from the compounds of amino acid type described above.

Said hydroxylated (poly)carboxylic acids may comprise several, in particular at least 2, COOH groups (in acid or salified form), better still 2 or 3 COOH groups (in acid or salified form). This is referred to as hydroxylated polycarboxylic acids.

Said (poly)acids may also comprise a single COOH group; these are then referred to as hydroxylated monocarboxylic acids.

The (poly)acids according to the invention include monoacids and polyacids.

The hydroxylated (poly)carboxylic acids according to the invention also comprise at least one OH group, but may comprise several of them, in particular from 2 to 3 OH groups.

Preferably, said hydroxylated (poly)carboxylic acids comprise in total from 4 to 6 carbon atoms.

The hydrocarbon chain of said hydroxylated (poly)carboxylic acids may be linear or branched, and saturated or unsaturated, and is preferably saturated and linear.

The salts of the (poly)acids comprise the salts with organic or mineral bases, for example the salts of alkali metals, such as the lithium, sodium or potassium salts; the salts of alkaline-earth metals, such as the magnesium or calcium salts, and the zinc salts. The alkali metal or alkaline-earth metal salts are preferred and in particular the sodium salts.

Advantageously, the hydroxylated monocarboxylic acids and/or salts thereof comprise in total from 4 to 6 carbon atoms, from 1 to 3 OH groups and 1 COOH group (in acid or salified form), and their hydrocarbon chain is saturated and linear.

Preferably, the hydroxylated monocarboxylic acids or salts thereof are chosen from alpha-hydroxy acids and salts thereof, and in particular from lactic or glycolic acids, and salts thereof, in particular alkali metal or alkaline-earth metal salts thereof.

Preferably, the composition C according to the invention comprises one or more hydroxylated polycarboxylic acids comprising in total 2 to 8 carbon atoms, and/or salts thereof; preferentially chosen from tartaric acid or citric acid, and salts thereof, in particular alkali metal or alkaline-earth metal salts thereof, such as sodium citrate and/or sodium tartrate; even better still chosen from citric acid, sodium citrate and mixtures thereof.

Preferably, the total content of hydroxylated (poly)carboxylic acids comprising in total 2 to 8 carbon atoms, and/or salts thereof, present in the composition C according to the invention is at least 0.5% by weight, in particular at least 1% by weight, relative to the total weight of the composition. This content may preferably range from 0.5% to 12% by weight, better still from 1% to 10% by weight, even better still from 1.5% to 8% by weight or even from 2% to 7% by weight, relative to the total weight of the composition.

In particular, the total content of hydroxylated polycarboxylic acids comprising in total from 4 to 6 carbon atoms, from 1 to 3 OH groups and 2 or 3 COOH groups, or salts thereof, present in the composition C according to the invention may range from 0.5% to 12% by weight, better still from 1% to 10% by weight, even better still from 1.5% to 8% by weight, or even from 2% to 7% by weight, relative to the total weight of the composition.

Most particularly, the total content of hydroxylated polycarboxylic acids chosen from tartaric acid or citric acid, and salts thereof, in particular alkali metal or alkaline-earth metal salts thereof, in the composition C according to the invention may range from 0.5% to 12% by weight, better still from 1% to 10% by weight, even better still from 1.5% to 8% by weight, or even from 2% to 7% by weight, relative to the total weight of the composition.

Even better still, the content of citric acid and/or salts thereof in the composition C according to the invention may range from 0.5% to 12% by weight, better still from 1% to 10% by weight, even better still from 1.5% to 8% by weight, or even from 2% to 7% by weight, relative to the total weight of the composition.

3/ Polyols

The composition C may advantageously comprise one or more polyols.

The term “polyol” means an organic compound constituted of a hydrocarbon chain optionally interrupted with one or more oxygen atoms and bearing at least two free hydroxyl groups (-OH), preferably borne by different carbon atoms, it being possible for this compound to be cyclic or acyclic, linear or branched, and saturated or unsaturated.

More particularly, the polyol(s) comprise from 2 to 30 hydroxyl groups, better still from 2 to 10 hydroxyl groups, preferentially from 2 to 3 hydroxyl groups. They preferably comprise from 2 to 10 carbon atoms, particularly from 2 to 8 carbon atoms and better still from 2 to 6 carbon atoms.

Advantageously, the polyol(s) are chosen from diols and/or triols comprising from 2 to 10 carbon atoms.

Mention may in particular be made of diglycerol, glycerol, propylene glycol, propane-1,3-diol, 1,3-butylene glycol, pentane-1,2-diol, octane-1,2-diol, dipropylene glycol, hexylene glycol, ethylene glycol, polyethylene glycols, sorbitol, sugars such as glucose and mixtures thereof; preferably from glycerol, propylene glycol, propane-1,3-diol, 1,3-butylene glycol, pentane-1,2-diol, octane-1,2-diol, dipropylene glycol, hexylene glycol, ethylene glycol, sorbitol and mixtures thereof; and even better still from glycerol, propylene glycol, propane-1,3-diol, and mixtures thereof.

Preferably, the polyol(s) may be present in the composition C in a total content ranging from 0.1% to 40% by weight, better still ranging from 1% to 35% by weight, even better still ranging from 5% to 30% by weight, and preferentially ranging from 10% to 25% by weight, relative to the total weight of the composition.

Preferably, the polyol(s) chosen from glycerol, propylene glycol, propane-1,3-diol, 1,3-butylene glycol, pentane-1,2-diol, octane-1,2-diol, dipropylene glycol, hexylene glycol, ethylene glycol, sorbitol and mixtures thereof may be present in the composition C in a total content ranging from 0.1% to 40% by weight, better still ranging from 1% to 35% by weight, even better still from 5% to 30% by weight, preferentially ranging from 10% to 25% by weight, relative to the total weight of the composition.

4/ Non-ionic surfactants

The composition C used in the process according to the invention may optionally comprise one or more non-ionic surfactants.

- oxyalkylenated (C₈-C₂₄)alkylphenols;

- fatty acid esters of sucrose;

- optionally oxyalkylenated alkyl (poly)glycosides (0 to 10 oxyalkylene units) which may comprise from 1 to 15 glucose units;

- saturated or unsaturated plant oils which are oxyethylenated;

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

- amine oxides.

Advantageously, the non-ionic surfactants according to the invention do not comprise any oxypropylene units.

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

Mention may be made of lauryl alcohol containing 4 mol of glycerol (INCI name: Polyglyceryl-4 Lauryl Ether), lauryl alcohol containing 1.5 mol of glycerol, oleyl alcohol containing 4 mol of glycerol (INCI name: Polyglyceryl-4 Oleyl Ether), oleyl alcohol containing 2 mol of glycerol (INCI name: Polyglyceryl-2 Oleyl Ether), cetearyl alcohol containing 2 mol of glycerol, cetearyl alcohol containing 6 mol of glycerol, oleocetyl alcohol containing 6 mol of glycerol, and octadecanol containing 6 mol of glycerol.

Non-ionic surfactants of alkyl (poly)glycoside type may in particular be represented by the following general formula: R₁O-(R₂O)_t-(G)_v, in which:

- R₁ represents a linear or branched alkyl or alkenyl radical including 6 to 24 carbon atoms and particularly 8 to 18 carbon atoms, or an alkylphenyl radical of which the linear or branched alkyl radical includes 6 to 24 carbon atoms and particularly 8 to 18 carbon atoms;

- R₂ represents an alkylene radical including 2 to 4 carbon atoms;

- G represents a sugar unit including 5 to 6 carbon atoms;

- t denotes a value ranging from 0 to 10 and preferably from 0 to 4;

- v denotes a value ranging from 1 to 15 and preferably from 1 to 4.

Preferably, the alkyl (poly)glycoside surfactants are compounds of the formula described above in which:

- R₁ denotes a linear or branched, saturated or unsaturated alkyl radical including from 8 to 18 carbon atoms;

- R₂ represents an alkylene radical including 2 to 4 carbon atoms;

- t denotes a value ranging from 0 to 3 and preferably equal to 0;

- G denotes glucose, fructose or galactose, preferably glucose;

- it being possible for the degree of polymerization, i.e. the value of v, to range from 1 to 15 and preferably from 1 to 4; the mean degree of polymerization more particularly being between 1 and 2.

The glucoside bonds between the sugar units are generally of 1-6 or 1-4 type, preferably of 1-4 type. Preferably, the alkyl (poly)glycoside surfactant is an alkyl (poly)glucoside surfactant. C8/C16 alkyl (poly)glucosides of 1-4 type, and in particular decyl glucosides and caprylyl/capryl glucosides, are most particularly preferred.

Among the commercial products, mention may be made of the products sold by Cognis under the names Plantaren® (600 CS/U, 1200 and 2000) or Plantacare® (818, 1200 and 2000); the products sold by SEPPIC under the names Oramix CG 110 and Oramix® NS 10; the products sold by BASF under the name Lutensol GD 70, or the products sold by Chem Y under the name AG10 LK.

Preferably, use is made of C₈/C₁₆ alkyl (poly)glycosides of 1-4 type, in particular as a 53% aqueous solution, such as those sold by Cognis under the reference Plantacare® 818 UP.

The non-ionic surfactant(s) used in the composition C according to the invention are preferentially chosen, alone or as a mixture, from:

- (C₈-C₃₀)alkyl (poly)glycosides which are optionally oxyalkylenated, preferably with from 0 to 10 mol of ethylene oxide, and which comprise from 1 to 15 glucose units;

More preferentially, the non-ionic surfactant(s) used in the composition C according to the invention are chosen, alone or as a mixture, from:

- (C₈-C₃₀)alkyl(poly)glucosides, which are optionally oxyalkylenated, preferably comprising from 0 to 10 mol of ethylene oxide and comprising 1 to 15 glucose units;

- saturated or unsaturated oxyethylenated plant oils comprising from 1 to 100 and preferably from 2 to 50 mol of ethylene oxide.

Preferably, the composition C according to the invention comprises the non-ionic surfactant(s) in a total content ranging from 0.1% to 10% by weight, preferably from 0.2% to 7% by weight, preferentially from 0.5% to 4% by weight, relative to the total weight of the composition according to the invention.

Additional compounds

The composition C according to the invention advantageously comprises water, in particular in a concentration preferably ranging from 40% to 95% by weight, for example from 45% to 90% by weight, in particular from 50% to 85% by weight, better still from 60% to 85% by weight, relative to the total weight of the composition.

The pH of the composition may be between 2.5 and 8, preferentially between 3 and 7, or even between 3.5 and 5.

The composition C used according to the invention may optionally comprise one or more preferably hydrophilic (water-soluble or water-miscible) organic solvents which are liquid at 25°C, 1 atm, which may be chosen from C₁-C₆ aliphatic or aromatic monoalcohols, C₂-C₈ polyols and C₃-C₇ polyol ethers. Advantageously, the organic solvent is chosen from C₂-C₄ mono-, di- or tri-diols. It may advantageously be chosen from ethanol, isopropanol, benzyl alcohol, glycerol, 1,2-propanediol (propylene glycol) and mixtures thereof.

The composition C according to the invention may also comprise at least one or more usual cosmetic ingredients chosen in particular from surfactants, in particular cationic surfactants; silicones; non-silicone liquid and/or solid fatty substances; thickeners and gelling agents; sunscreens; anti-dandruff agents; antioxidants; chelating agents; reducing agents; oxidation bases, couplers, oxidizing agents, direct dyes; straighteners; nacreous agents and opacifiers; micas, nacres, flakes; pigments; fillers; fragrances; pH modifiers. A person skilled in the art will take care to select the ingredients included in the composition, and also the amounts thereof, so that they do not harm the properties of the compositions of the present invention.

In particular, the composition C may advantageously comprise one or more thickeners, preferably chosen from thickening polymers and even better still from thickening polysaccharides, which may be of natural or synthetic origin.

The polysaccharides may be anionic, non-ionic, cationic or amphoteric; they are preferably anionic or non-ionic.

The base units of the polysaccharides may be mono- or disaccharides. The units that may be included in the composition of the polysaccharides are preferably derived from the following sugars: glucose, galactose, arabinose, rhamnose, mannose, xylose, fucose, fructose, anhydrogalactose.

Mention may in particular be made, as thickening polysaccharides, of the following polymers, and also derivatives thereof:

- guar gum (polymer of mannose and galactose),

- locust bean 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),

- scleroglucan gum (glucose polymer),

- cellulose (glucose polymer),

- starch (glucose polymer);

- inulin (polymer of fructose and glucose).

These polymers can be physically or chemically modified. A physical treatment that may in particular be mentioned is the temperature. As chemical treatment, mention may be made of esterification, etherification, amidation and oxidation reactions. These treatments make it possible to obtain polymers which can be non-ionic, cationic or amphoteric.

The non-ionic guar gums that may be used according to the invention may be modified with C₁-C₆ hydroxyalkyl groups. Among the hydroxyalkyl groups, mention may be made of hydroxymethyl, hydroxyethyl, hydroxypropyl and hydroxybutyl groups. These guar gums are well known in the prior art and may be prepared, for example, by reacting corresponding alkene oxides, for instance propylene oxides, with the guar gum so as to obtain a guar gum modified with hydroxypropyl groups. The degree of hydroxyalkylation preferably ranges 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. Such non-ionic guar gums optionally modified with hydroxyalkyl groups are sold, for example, under the trade names Jaguar HP8, Jaguar HP60 and Jaguar HP120 by Rhodia Chimie.

The guar gums modified with cationic groups that may more particularly be used according to the invention are guar gums including trialkylammonium cationic groups. Preferably, 2% to 30% by number of the hydroxyl functions of these guar gums bear cationic trialkylammonium groups. Even more preferentially, 5% to 20% by number of the hydroxyl functions of these guar gums are branched with cationic trialkylammonium groups. Among these trialkylammonium groups, mention may most particularly be made of the trimethylammonium and triethylammonium groups. Even more preferentially, these groups represent from 5% to 20% by weight relative to the total weight of the modified guar gum. According to the invention, guar gums modified with 2,3-epoxypropyltrimethylammonium chloride may be used. These guar gums modified with cationic groups are products already known per se and are for example described in patents US 3 589 578 and US 4 0131 307. Such products are sold particularly under the trade names Jaguar C13 S, Jaguar C 15 and Jaguar C 17 by Rhodia Chimie.

As modified locust bean gum, use may be made of cationic locust bean gum containing hydroxypropyltrimonium groups, such as Catinal CLB 200 sold by Toho.

The starch molecules used in the present invention may originate from any plant source of starch, in particular cereals and tubers; more particularly, they may be starches from corn, rice, cassava, barley, potato, wheat, sorghum, pea, oat or tapioca. Use may also be made of the starch hydrolysates mentioned above or other starch derivatives. The starch is preferably derived from potato. The starches may be chemically or physically modified, in particular by one or more of the following reactions: pregelatinization, oxidation, crosslinking, esterification, etherification, amidation, heat treatments.

More particularly, these reactions may be performed in the following manner:

- pregelatinization by splitting the starch granules (for example drying and cooking in a drying drum);

- oxidation by strong oxidants leading to the introduction of carboxyl groups into the starch molecule and to the depolymerization of the starch molecule (for example by treating an aqueous starch solution with sodium hypochlorite);

- crosslinking with functional agents that are able to react with the hydroxyl groups of the starch molecules, which will thus be bonded together (for example with glyceryl and/or phosphate groups);

- esterification in alkaline medium for the grafting of functional groups, particularly C₁-C₆ acyl (acetyl), C₁-C₆ hydroxyalkyl (hydroxyethyl or hydroxypropyl), carboxymethyl or octenylsuccinic.

Among the starch derivatives, mention may particularly be made of dextrins.

According to the invention, use may also be made of amphoteric starches comprising one or more anionic groups and one or more cationic groups. The anionic and cationic groups may be bonded to the same reactive site of the starch molecule or to different reactive sites; they are preferably bonded to the same reactive site. The anionic groups can be of carboxylic, phosphate or sulfate type, preferably of carboxylic type. The cationic groups may be of primary, secondary, tertiary or quaternary amine type.

The amphoteric starches are particularly chosen from the compounds of the following formulae:

in which:

St-O represents a starch molecule,

R, which is identical or different, represents a hydrogen atom or a methyl radical;

R', which is identical or different, represents a hydrogen atom, a methyl radical or a -COOH group;

n is an integer equal to 2 or 3,

M, which is identical or different, denotes a hydrogen atom, an alkali metal or alkaline-earth metal such as Na, K, Li or NH₄, a quaternary ammonium or an organic amine,

R" represents a hydrogen atom or a C₁-C₁₈ alkyl radical.

Use is in particular made of the starches of formulae (IIa) or (IIIa); and preferentially starches modified with 2-chloroethylaminodipropionic acid, i.e. the starches of formulae (IIa) or (IIIa) in which R, R', R'' and M represent a hydrogen atom and n is equal to 2. The preferred amphoteric starch is a starch chloroethylamidodipropionate.

The celluloses and cellulose derivatives may be anionic, cationic, amphoteric or non-ionic. Among these derivatives, mention may be made of cellulose ethers, cellulose esters and cellulose ester ethers.

Among the non-ionic cellulose ethers, mention may be made of alkyl celluloses such as methyl celluloses and ethyl celluloses (for example Ethocel Standard 100 Premium from Dow Chemical); hydroxyalkyl celluloses such as hydroxymethyl celluloses and hydroxyethyl celluloses (for example Natrosol 250 HHR sold by Aqualon) and hydroxypropyl celluloses (for example Klucel EF from Aqualon); mixed hydroxyalkyl alkyl celluloses such as hydroxypropyl methyl celluloses (for example Methocel E4M from Dow Chemical), hydroxyethyl methyl celluloses, hydroxyethyl ethyl celluloses (for example Bermocoll E 481 FQ from Akzo Nobel) and hydroxybutyl methyl celluloses.

Among the cationic cellulose ethers, mention may be made of crosslinked or non-crosslinked quaternized hydroxyethylcelluloses. The quaternizing agent may particularly be diallyldimethylammonium chloride (for example Celquat L200 from National Starch). Another cationic cellulose ether that may be mentioned is hydroxypropyltrimethylammonium hydroxyethyl cellulose (for example Ucare Polymer JR 400 from Amerchol).

Preferably, the composition comprises one or more thickeners chosen from, alone or as a mixture, non-ionic polysaccharides, better still chosen from, alone or as a mixture, non-ionic guar gums modified with C₁-C₆ hydroxyalkyl groups.

The composition according to the invention can comprise the thickener(s) in a total amount ranging from 0.05% to 10% by weight, in particular from 0.1% to 5% by weight and preferentially from 0.15% to 3% by weight, relative to the total weight of the composition.

In particular, the composition according to the invention may comprise one or more non-ionic polysaccharides in a total amount ranging from 0.05% to 10% by weight, in particular from 0.1% to 5% by weight, preferentially from 0.15% to 3% by weight, relative to the total weight of the composition.

The present invention is illustrated in greater detail in the examples that follow (AM = active material).

Example 1

The following compositions used in the context of the invention are prepared (% by weight of active material):

INCI NAME	Composition A step (i)
Aminopropyltriethoxysilane	10
Polyquaternium-6	1
Amino acids (glycine, arginine, serine, glutamic acid)	1.8
Citric acid	4.4
PEG-40 hydrogenated castor oil	2
Preserving agents	qs
Water	qs 100%

INCI NAME	Composition C step (iii)
Glycerol	15
Propylene glycol	5
Amino acids (glycine, arginine, glutamic acid, serine)	5.8
Citric acid	3
Non-ionic surfactant	2.5
Cationic polymer	1.2
Cationic surfactant	1
Thickener	0.2
Preserving agents	qs
Water	qs 100%

The composition A above is applied to previously wetted hair and left on for a few minutes (0 to 5 minutes).

A standard shampoo composition (comprising anionic and amphoteric surfactants) is then applied to unrinsed hair, which is washed in the usual way, and then rinsed with water.

The composition C is then applied, and left on for a few minutes before rinsing the hair with water, then the hair is dried with a hair dryer or the hair is left to dry in the open air.

Before drying, it is observed that wet hair disentangles very easily.

After drying, it is found that the hair appears as repaired from the inside and visibly strengthened; the disentangling, smooth feel and elasticity of the hair are improved. The hair repair is uniform from root to tip.

The process according to the invention makes it possible to obtain the combination of a repair at the heart of the fibre with instant disentangling, especially on wet hair, and the provision of force, in a persistent manner.

Example 2

The denaturation temperature of locks treated according to the invention is compared with that of comparative locks.

P1: Protocol according to the invention

Step 1: The composition A of Example 1 is applied to locks of moderately sensitized hair (AS20) in a proportion of 0.4 g of composition per gram of lock. The composition is left on the hair for a leave-on time of 5 minutes.

Step 2: A shampoo composition is applied in a proportion of 0.4 g of composition per gram of lock. The locks are then rinsed with water.

Step 3: the composition C of Example 1 is applied in a proportion of 0.4 g of composition per gram of lock, followed by rinsing with water after a leave-on time of 5 minutes.

Steps 2 and 3 are repeated 4 times.

P2: Comparative protocol

Step 1: The shampoo composition is applied to locks of moderately sensitized hair (AS20) in a proportion of 0.4 g of composition per gram of lock. The locks are then rinsed with water.

Step 2: the composition C is applied in a proportion of 0.4 g of composition per gram of lock, followed by rinsing with water after a leave-on time of 5 minutes.

Steps 1 and 2 are repeated 4 times.

The integrity (i.e. repair) of the keratin fibres of the locks is then evaluated by differential scanning calorimetry (also called DSC).

The principle of the test consists in measuring the protein denaturing temperature. The higher the protein denaturing temperature, the better the integrity of the proteins in the cortex, which reflects a greater strength of the fibres.

The following results are obtained:

	Untreated control	Protocol 1 invention	Protocol 2 comparative
Denaturing temperature (°C)	141.3	156.9	154

It is noted that the protocol P1 according to the invention makes it possible to significantly increase the fibre protein denaturing temperature compared to the comparative protocol P2.

The protocol according to the invention therefore makes it possible to improve the strengthening/repair of the hair.

Example 3

The compositions A, A2 and C1 are prepared from the ingredients the contents of which are indicated in the table below (in % of active material per 100 g of composition)

Pre-shampoo: compositions A/A2

	A invention	A2 comparative
AMINOPROPYL TRIETHOXYSILANE	10	10
POLYQUATERNIUM-6	1	1
Arginine	1.8	1.8
Citric acid	4.4	-
Lactic acid	-	4.4
PEG-40 HYDROGENATED CASTOR OIL	2	2
Preservatives (phenoxyethanol)	q.s.	q.s.
Water	q.s. for 100%	q.s. for 100%

Post-shampoo: composition C1

	C1
Glycerol	15
Propylene glycol	5
Glycine	5.8
Citric acid	3
POLYSORBATE 20	0.8
POLYSORBATE 80	0.8
PEG-40 HYDROGENATED CASTOR OIL	1
Quaternium 80	0.3825
HYDROXYPROPYL GUAR HYDROXYPROPYLTRIMONIUM Cl	0.2
HYDROXYPROPYLTRIMONIUM HYDROLYZED WHEAT PROTEIN	1
CETRIMONIUM CHLORIDE	1
HYDROXYPROPYL GUAR	0.2
Preservatives	q.s.
Water	q.s. for 100%

Application protocol

Step 1: Composition A or A2

Composition A or A2 above is applied to pre-wetted, highly sensitized (AS 50, alkaline solubility = 50%) locks of hair weighing 5.4 g, in a proportion of 2.5 g of composition per lock. The mixture is left on for 5 minutes before rinsing.

Step 2: Shampoo

A standard shampoo composition (comprising anionic and amphoteric surfactants) is then applied, washing is performed in the usual way, and then the hair is rinsed with water.

Step 3: comp C1

Composition C1 is then applied in a proportion of 2.5 g per lock, left on for 5 minutes before rinsing the hair with water, and then the hair is dried with a hair dryer.

Results:

The performance qualities in terms of body/strength were evaluated blind on locks of dry hair by 6 experts, on a scale ranging from 0 (poor) to 5 (very good).

The evaluation of body is tactile: the expert takes the lock in their hand, exerting lateral pressure on the lock. They evaluate the resistance and the density of the lock. The more dense and resistant to pressure (rigid) the lock, the more body/strength it has.

The scores and averages obtained are presented below:

	Method A + shampoo + C1 according to the invention	Method A2 + shampoo + C1 comparative
Expert 1	3.5	3.5
Expert 2	3.5	2.5
Expert 3	4	3
Expert 4	4	3
Expert 5	4	3
Expert 6	4.5	3
Average	3.9	3.0
Standard deviation	0.4	0.3

The experts considered that the hair treated with the compositions A + shampoo + C1 according to the method of the invention exhibited more body/strength than the hair treated with the compositions A2 + shampoo + C1 according to the comparative method.

These results are significant in view of the standard deviations.

The invention made it possible to improve the provision of body/strength to the hair.

Claims

Cosmetic treatment process, preferably hair treatment process, for keratin fibres, in particular the hair, comprising:
- a step (i) of applying, to said keratin fibres, a cosmetic composition A comprising one or more organosilanes and at least 0.5% by weight of one or more hydroxylated polycarboxylic acids, comprising 2 to 8 carbon atoms, and/or salts thereof, then
- a step (ii) of washing said keratin fibres, comprising the application of a cleansing cosmetic composition B comprising one or more anionic surfactants and/or one or more amphoteric surfactants, then
- a step (iii) of applying, to said keratin fibres, a cosmetic composition C comprising one or more compounds of amino acid type and one or more hydroxylated (poly)carboxylic acids, comprising from 2 to 8 carbon atoms, and/or salts thereof.
Process according to Claim 1, in which the composition A comprises one or more organosilanes chosen from compounds of formula (I) and/or oligomers thereof and/or hydrolysis products thereof:
R₁Si(OR₂)z(R₃)x(OH)y (I)
in which:
- R₁ is a cyclic or acyclic, linear or branched, saturated or unsaturated C₁-C₂₂, in particular C₂-C₂₀, hydrocarbon chain, which may be substituted with a group chosen from amine groups NH₂ or NHR (R being a linear or branched C₁-C₂₀, in particular C₁-C₆, alkyl, a C₃-C₄₀ cycloalkyl or a C₆-C₃₀ aromatic radical); the hydroxyl group (OH), a thiol group, an aryl group (more particularly benzyl), which is possibly substituted with an NH₂ or NHR group; it being possible for R₁to be interrupted with a heteroatom (O, S or NH) or a carbonyl group (CO),
- R₂ and R₃, which may be identical or different, represent a linear or branched alkyl group comprising from 1 to 6 carbon atoms,
- y denotes an integer ranging from 0 to 3,
- z denotes an integer ranging from 0 to 3, and
- x denotes an integer ranging from 0 to 2, with z + x + y = 3;
preferably, R₁ is a linear or branched, saturated C₁-C₁₂, in particular C₂-C₆, hydrocarbon chain substituted with an NH₂ amine group, R₂ represents an alkyl group comprising from 1 to 4 carbon atoms, and z = 3 (and therefore x = y = 0); better still, the organosilane(s) are chosen from methyltriethoxysilane (MTES), octyltriethoxysilane (OTES), dodecyltriethoxysilane, octadecyltriethoxysilane, hexadecyltriethoxysilane, 3-aminopropyltriethoxysilane (APTES), 2-aminoethyltriethoxysilane (AETES), 3-aminopropylmethyldiethoxysilane, N-(2-aminoethyl)-3-aminopropyltriethoxysilane, 3-(m-aminophenoxy)propyltrimethoxysilane, p-aminophenyltrimethoxysilane, N-(2-aminoethylaminomethyl)phenethyltrimethoxysilane, and oligomers thereof, and/or mixtures thereof; and more particularly chosen from methyltriethoxysilane (MTES) and 3-aminopropyltriethoxysilane (APTES), oligomers thereof, hydrolysis products thereof and/or mixtures thereof; and even better still chosen from 3-aminopropyltriethoxysilane (APTES), oligomers thereof and/or hydrolysis products thereof.
Process according to either of the preceding claims, in which the organosilane(s) are present in the composition A according to the invention in a total content of at least 6% by weight relative to the total weight of the composition, preferably in a total content ranging from 6% to 20% by weight, preferentially from 7% to 15% by weight, better still from 8% to 13% by weight, relative to the total weight of the composition.
Process according to one of the preceding claims, in which the cosmetic composition A used in step (i) comprises one or more cationic polymers; preferably chosen from, alone or as a mixture:
- alkyldiallylamine or dialkyldiallylammonium cyclopolymers, and in particular homopolymers or copolymers of dimethyldiallylammonium salts (for example chloride);
- optionally crosslinked homopolymers or copolymers of methacryloyloxy(C₁-C₄)alkyltri(C₁-C₄)alkylammonium salts;
- celluloses and galactomannan gums that are cationic.
Process according to one of the preceding claims, in which the cosmetic composition A used in step (i) comprises one or more compounds of the amino acid type; preferably chosen from the compounds corresponding to formula (I) below and/or salts thereof:

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 ring members, preferably 5 ring members, it being possible for this ring to be optionally substituted with one or more groups chosen from hydroxyl or (C₁-C₄)alkyl;
- when p = 2, R represents a hydrogen atom or else a saturated, linear or branched, (C₁-C₁₂)alkyl, preferably (C₁-C₄)alkyl, group, optionally interrupted with one or more heteroatoms or groups chosen from –S–, –NH– or –C(NH)– and/or optionally substituted with one or more groups chosen from hydroxyl (-OH), amino (-NH₂), -SH, -COOH, -CONH₂ or –NH–C(NH)–NH₂ or a C₅-C₇ aryl group, in particular phenyl, itself optionally substituted with one or more OH;
preferably chosen from glycine, arginine, tyrosine, methionine, serine, glutamic acid, lysine, salts thereof (particularly alkali metal, alkaline-earth metal or zinc salts) and mixtures thereof.
Process according to one of the preceding claims, in which the cosmetic composition A used in step (i) comprises at least 0.5% of one or more hydroxylated polycarboxylic acids and/or salts thereof comprising in total from 4 to 6 carbon atoms, from 1 to 3 OH groups and 2 to 3 COOH groups (in acid or salified form); in particular chosen from tartaric acid or citric acid, and salts thereof, in particular alkali metal or alkaline-earth metal salts.
Process according to one of the preceding claims, in which the washing cosmetic composition B used in step (ii) comprises one or more anionic surfactants chosen from, alone or as a mixture:
- C₆-C₂₄ and in particular C₁₂-C₂₀ alkyl sulfates;
- C₆-C₂₄ and in particular C₁₂-C₂₀ alkyl ether sulfates; preferably comprising from 2 to 20 ethylene oxide units;
- C₆-C₂₄ and in particular C₁₂-C₂₀ alkylsulfosuccinates, in particular laurylsulfosuccinates;
- C₆-C₂₄ and in particular C₁₂-C₂₀ olefin sulfonates;
- C₆-C₂₄ and in particular C₁₂-C₂₀ alkyl ether sulfosuccinates;
- (C₆-C₂₄)acylisethionates and preferably (C₁₂-C₁₈)acylisethionates;
- C₆-C₂₄ acylsarcosinates, in particular C₁₂-C₂₀ acylsarcosinates; in particular palmitoylsarcosinates and lauroylsarcosinates;
- (C₆-C₂₄)alkyl ether carboxylates, preferably (C₁₂-C₂₀)alkyl ether carboxylates; in particular those including from 2 to 50 ethylene oxide groups;
- polyoxyalkylenated (C₆-C₂₄)alkylamido ether carboxylic acids and salts thereof, in particular those including from 2 to 50 alkylene oxide and in particular ethylene oxide groups;
- C₆-C₂₄ and in particular C₁₂-C₂₀ acylglutamates;
- C₆-C₂₄ and in particular C₁₂-C₂₀ acylglycinates;
- C₆-C₂₄ alkyl sulfoacetates, in particular C₁₂-C₂₀ alkyl sulfoacetates,
in particular in acid form or in the form of alkali metal or alkaline-earth metal, ammonium or amino alcohol salts.
Process according to one of the preceding claims, in which the cosmetic composition B used in step (ii) comprises one or more amphoteric surfactants chosen from (C₈-C₂₀)alkylbetaines, (C₈-C₂₀)alkylsulfobetaines, (C₈-C₂₀)alkylamido(C₃-C₈)alkylbetaines and (C₈-C₂₀)alkylamido(C₆-C₈)alkylsulfobetaines, and the compounds having the respective structures (II), (III) and (IV) below:
R_a-CONHCH₂CH₂-N⁺(R_b)(R_c)-CH₂COO^-, M⁺, X^- (II)
in which:
- R_a represents a C₁₀ to C₃₀ alkyl or alkenyl group derived from an acid R_aCOOH preferably present in hydrolysed coconut kernel oil, or a heptyl, nonyl or undecyl group;
- R_b represents a β-hydroxyethyl group; and
- R_c represents a carboxymethyl group;
- M⁺ represents a cationic counterion derived from an alkali metal or alkaline-earth metal, such as sodium, an ammonium ion or an ion derived from an organic amine, and
- X^- represents an organic or inorganic anionic counterion, such as that chosen from halides, acetates, phosphates, nitrates, (C₁-C₄)alkyl sulfates, (C₁-C₄)alkyl- or (C₁-C₄)alkylaryl-sulfonates, in particular methyl sulfate and ethyl sulfate; or alternatively M⁺ and X^- are absent;
R_a’-CONHCH₂CH₂-N(B)(B’) (III)
in which:
- B represents the group -CH₂CH₂OX’;
- B’ represents the group -(CH₂)_zY’, with z = 1 or 2;
- X’ represents the group -CH₂COOH, -CH₂-COOZ’, -CH₂CH₂COOH or CH₂CH₂-COOZ’, or a hydrogen atom;
- Y’ represents the group -COOH, -COOZ’ or -CH₂CH(OH)SO₃H or the group CH₂CH(OH)SO₃-Z’;
- Z’ represents a cationic counterion derived from an alkali metal or alkaline-earth metal, such as sodium, an ammonium ion or an ion derived from an organic amine;
- R_a’ represents a C₁₀ to C₃₀ alkyl or alkenyl group of an acid R_a’-COOH which is preferably present in hydrolysed linseed oil or coconut kernel oil, an alkyl group, particularly a C₁₇ alkyl group, and its iso form, or an unsaturated C₁₇ group.
R_a’’-NHCH(Y’’)-(CH₂)_nCONH(CH₂)_n’-N(R_d)(R_e) (IV)
in which:
- Y’’ represents the group -COOH, -COOZ’’ or -CH₂CH(OH)SO₃H or the group CH₂CH(OH)SO₃-Z’’;
- R_d and R_e, independently of one another, represent a C₁ to C₄ alkyl or hydroxyalkyl radical;
- Z’’ represents a cationic counterion derived from an alkali metal or alkaline-earth metal, such as sodium, an ammonium ion or an ion derived from an organic amine;
- R_a'' represents a C₁₀ to C₃₀ alkyl or alkenyl group of an acid R_a''-COOH which is preferably present in hydrolysed linseed oil or coconut kernel oil;
- n and n' denote, independently of one another, an integer ranging from 1 to 3;
preferentially chosen from (C₈-C₂₀)alkylbetaines such as cocobetaine, (C₈-C₂₀)alkylamido(C₃-C₈)alkylbetaines such as cocamidopropylbetaine, and mixtures thereof.
Process according to one of the preceding claims, in which the cosmetic composition C used in step (iii) comprises one or more compounds of amino acid type chosen from the compounds corresponding to formula (I) below and/or salts thereof:

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 ring members, preferably 5 ring members, it being possible for this ring to be optionally substituted with one or more groups chosen from hydroxyl or (C₁-C₄)alkyl;
- when p = 2, R represents a hydrogen atom or else a saturated, linear or branched, (C₁-C₁₂)alkyl, preferably (C₁-C₄)alkyl, group, optionally interrupted with one or more heteroatoms or groups chosen from –S–, –NH– or –C(NH)– and/or optionally substituted with one or more groups chosen from hydroxyl (-OH), amino (-NH₂), -SH, -COOH, -CONH₂ or –NH–C(NH)–NH₂ or a C₅-C₇ aryl group, in particular phenyl, itself optionally substituted with one or more OH;
preferably, p = 2 and R represents a hydrogen atom or a saturated, linear or branched, (C₁-C₄)alkyl group, optionally interrupted with a –S– heteroatom and/or optionally substituted with one or two groups chosen from hydroxyl, amino or –NH–C(NH)–NH₂; better still R represents a hydrogen atom;
preferentially chosen from glycine, arginine, tyrosine, methionine, serine, glutamic acid, lysine, salts thereof (particularly alkali metal, alkaline-earth metal or zinc salts) and mixtures thereof.
Process according to one of the preceding claims, in which the cosmetic composition C used in step (iii) comprises one or more compounds of amino acid type in a total content of at least 0.5% by weight relative to the total weight of the composition, better still ranging from 0.5% to 12% by weight, in particular from 1% to 10% by weight, better still from 2% to 8% by weight, even better still from 3% to 7% by weight, relative to the total weight of the composition.
Process according to one of the preceding claims, in which the cosmetic composition C used in step (iii) comprises one or more hydroxylated (poly)carboxylic acids comprising 2 to 8 carbon atoms, and/or salts thereof chosen from hydroxylated polycarboxylic acids and/or salts thereof comprising in total from 4 to 6 carbon atoms, from 1 to 3 OH groups and from 2 to 3 COOH groups (in acid or salified form); better still chosen from tartaric acid or citric acid, and salts thereof, in particular alkali metal or alkaline-earth metal salts; most particularly sodium citrate and/or sodium tartrate; even better still citric acid or salts thereof, in particular alkali metal or alkaline-earth metal salts, such as sodium citrate.
Process according to one of the preceding claims, in which the cosmetic composition C used in step (iii) comprises one or more hydroxylated (poly)carboxylic acids comprising in total 2 to 8 carbon atoms, and/or salts thereof, in a total content of at least 0.5% by weight, in particular at least 1% by weight, relative to the total weight of the composition; better still ranging from 0.5% to 12% by weight, better still from 1% to 10% by weight, even better still from 1.5% to 8% by weight, or even from 2% to 7% by weight, relative to the total weight of the composition.
Process according to one of the preceding claims, in which the cosmetic composition C used in step (iii) comprises one or more polyols, preferably chosen from diols and/or triols, comprising from 2 to 10 carbon atoms; in particular chosen from diglycerol, glycerol, propylene glycol, propane-1,3-diol, 1,3-butylene glycol, pentane-1,2-diol, octane-1,2-diol, dipropylene glycol, hexylene glycol, ethylene glycol, polyethylene glycols, sorbitol, sugars such as glucose and mixtures thereof; preferably from glycerol, propylene glycol, propane-1,3-diol, 1,3-butylene glycol, pentane-1,2-diol, octane-1,2-diol, dipropylene glycol, hexylene glycol, ethylene glycol, sorbitol and mixtures thereof; and even better still from glycerol, propylene glycol, propane-1,3-diol, and mixtures thereof.
Process according to one of the preceding claims, in which the cosmetic composition C used in step (iii) comprises one or more non-ionic surfactants; preferably chosen from, alone or as a mixture:
- saturated or unsaturated, linear or branched, oxyethylenated C₈ to C₄₀ alcohols comprising from 1 to 100 mol of ethylene oxide, preferably from 2 to 50 mol of ethylene oxide and more particularly from 2 to 40 mol of ethylene oxide and comprising one or two fatty chains, in particular at least one C₈-C₂₀, in particular C₁₀-C₁₈, alkyl chain;
- preferably oxyethylenated esters of saturated or unsaturated, linear or branched, C₈ to C₃₀ acids and of sorbitol, and
- (C₈-C₃₀)alkyl(poly)glucosides, which are optionally oxyalkylenated, preferably comprising from 0 to 10 mol of ethylene oxide and comprising 1 to 15 glucose units;
- saturated or unsaturated oxyethylenated plant oils comprising from 1 to 100 and preferably from 2 to 50 mol of ethylene oxide.
Process according to one of the preceding claims, in which the cosmetic composition C used in step (iii) comprises one or more thickeners, preferably chosen from thickening polymers, and even better still from thickening polysaccharides, that are preferably preferably anionic or non-ionic.
Process according to one of the preceding claims, for visibly reinforcing the fibre and/or for improving the disentangling, advantageously in a persistent manner.