surfactants

The present invention relates to a reducing composition comprising one or more sulfur-containing reducing agents, preferably thio l agents, one or more fatty substances solid at room temperature, one or more cationic surfactants and two or more than two nonionic surfactants selected from polyoxyalkylenated fatty alcoho ls having an ethylene oxide number of greater than or equal to 10, with the proviso that at least two of said nonionic surfactants have a difference in HLB of greater than or equal to 2.

The invention also relates to a method for permanent deformation o f keratinous fibres, more particularly of human keratinous fibres such as the hair, which comprises the use on said fibres of the reducing composition defined above and, optionally, of an oxidizing composition.

Many people are dissatisfied with the appearance of their hair, especially those people who have curly hair and usually wish to acquire smooth hair, and, conversely, those people who have straight hair and wish to have curly hair.

One o f the techniques commonly used in order to obtain permanent deformation o f the hair invo lves a two-step procedure, the first step of which is to reduce the disulfide bridges present in the keratinous fibre, using a composition containing a suitable reducing agent (reduction step) . Once these disulfide bridges have been reduced, the hair is then shaped in the desired manner. This shaping step may invo lve frizzing the hair or else smoothing it, the result being dependent on the means employed to tension the hair and on the nature of the original keratinous fibres . This tensioning operation may be carried out before, during or after the application o f the reducing composition to the hair. Once this first step has been performed, an oxidation step is necessary in order to recreate the disulfide bridges and to stabilize the shape obtained. This operation is commonly carried out using an oxidizing composition (in a step also called the setting step).

This technique therefore allows the hair to be waved (perming procedure) and/or smoothed (straightening). The new shape imposed on the hair by a chemical treatment as stated above is durable over time and resistant particularly to the action of washing with water or using shampoos, as opposed to simple, conventional techniques o f temporary deformation, such as setting.

The reducing compositions intended for smoothing or perming of the hair generally include reducing agents in the form of sulfites, bisulfites, alkylphosphines or, preferably, thio ls . These reducing compositions are generally in the form of a thickened or unthickened lotion, a cream or a gel.

The majority o f the cream vehicles used for manufacturing reducing compositions are formulated on the basis o f crystallizable compounds, such as fatty alcoho ls, for example, especially cetylstearyl alcoho l, or fatty acid esters, for example cetyl palmitate. These compounds, which are solid at room temperature, are generally melted and then introduced in aqueous phase and emulsified in the hot state . The emulsion is subsequently cooled, thus causing crystallization of these compounds in the form of so lid particles o f micro-scale size, in other words in the form o f crystals . In order to realize the emulsifying step, ionic and/or nonionic surfactants are generally introduced into the formulations . The role o f these surfactants is to make the emulsion finer and to produce a smooth and creamy dispersion with no lumps .

Generally speaking, subsequent to the addition o f the reducing agents and other compounds, especially fragrances, it is found that these vehicles may have an unsatisfactory texture. More specifically, a significant drop in viscosity is observed fo llowing the addition o f these compounds, and especially of fragrance, and this leads generally to the creams obtained having an excessively fluid texture, possibly resembling that of a milk, or having a disparate and flo cculated appearance which is unacceptable in terms of product quality.

In other words, the resulting reducing compositions do not have satisfactory texture fo llowing the addition o f reducing agents and of other compounds, and especially after the addition o f fragrances.

Moreover, vehicles of this kind may have uncertain stability in preservation tests, with problems of lo ss o f viscosity or of phase separation/bodying.

There is therefore a real need to employ reducing compositions, intended for use during a method for permanent deformation o f keratinous fibres, which are devoid o f all of the drawbacks described above, in other words having satisfactory texture, without the need to increase the level of non-oxyalkylenated fatty substances, and which are stable in storage.

The applicant has found, surprisingly, that it was possible for the desired properties to be obtained by combination, in a reducing composition, of one or more sulfur-containing reducing agents, one or more fatty substances solid at room temperature, one or more cationic surfactants and two or more than two polyoxyalkylenated nonionic surfactants of particular chemical kind, and having an ethylene oxide unit number of greater than or equal to 10; with the proviso that at least two of said nonionic surfactants have a difference in HLB o f greater than or equal to 2.

The combination defined above, indeed, allows reducing compositions to be obtained that have a satisfactory texture and are homogeneous throughout the manufacturing process . It is found especially that the reducing compositions exhibit a smooth and uniform texture throughout their manufacture, including at the end, after the addition o f reducing agents and of fragrances.

More particularly it is found that the viscosity o f the compositions remains constant during the manufacturing process and does not vary significantly with the introduction o f fragrances, which are generally responsible for triggering a substantial fall in the viscosity in the prior-art reducing compositions . Accordingly, the final reducing composition has a thick, uniform and smooth texture.

Furthermore, the above-defined combination also allows the reducing compositions obtained to be stable on the shelf, in the presence o f reducing agents or fragrances, these compositions being more particularly those which are stable on storage at room temperature (25 °C) or at temperatures of up to 45 ° C .

By "stable" in the sense o f the present invention is meant that the visual appearance, the texture and the viscosity o f the reducing compositions does not change substantially over the course o f time under conditions o f storage at room temperature or at temperatures less than or equal to 45 °C , for a number of days after their manufacture.

In other words, it is found that the viscosity and texture of the reducing compositions is not adversely affected over time, and that the problems o f phase separation or of bodying are minimized, or even suppressed, in a satisfactory way.

The reducing compositions may be used in a permanent deformation process, especially for smoothing or perming keratinous fibres, in a satisfactory way, while endowing said fibres with good cosmetic properties.

Accordingly, the reducing compositions have enhanced physicochemical properties and do not adversely affect the performance characteristics of the methods for permanent deformation of keratinous fibres.

The present invention accordingly provides in particular a reducing cosmetic composition comprising one or more sulfur- containing reducing agents, one or more fatty substances solid at room temperature, one or more cationic surfactants and two or more than two nonionic surfactants selected from polyoxyalkylenated fatty alcoho ls having an ethylene oxide unit number o f greater than or equal to 10, with the proviso that at least two of said polyoxyalkylenated fatty alcohols having an ethylene oxide unit number of greater than or equal to 10 have a difference in HLB of greater than or equal to 2. The reducing composition according to the invention spreads easily over the keratinous fibres, thereby facilitating its application in the course of a method for permanent deformation o f the keratinous fibres, and can be rinsed o ff easily.

The reducing composition according to the invention is present preferably in the form of a cream for the treatment of keratinous fibres, more particularly o f human keratinous fibres such as the hair.

The invention further, accordingly, provides a method for permanent deformation o f keratinous fibres, more particularly o f human keratinous fibres such as the hair, which comprises :

- a step of applying to said fibres a reducing composition as defined above, and the time sufficient for shaping is allowed to elapse, and

- optionally, a step of app lying to said fibres an oxidizing composition for a time sufficient for the fixing o f the shape.

The method for permanent deformation allows the keratinous fibres to be smoothed or waved, while endowing them with good cosmetic properties.

Further obj ects, features, aspects and advantages of the invention will emerge more clearly from the reading o f the description and examples which fo llow.

As indicated above, the reducing composition comprises one or more sulfur-containing reducing agents, preferably selected from the reducing agents of formula:

H(X' ) _q (R' ) _r in which X' represents S or S0 ₂ , q is 1 , r is 1 or 2 or 3 and R' is a saturated or unsaturated, linear or branched hydrocarbon radical (C ₁ -C ₂₀ ) which is optionally interrupted by a heteroatom, and optionally comprises substituents selected from a hydroxyl group, a halogen group, an amine group or a salified or non-salified carboxyl group, a ((C i - C3 o)alkoxy)carbonyl group, an amido group , a ((C i - C3 o)alkyl)amino carbonyl group, a ((C i - C3 o)acyl)amino group, a mono- or dialkylamino group, a mono- or dihydroxyamino group, or one of its salts in combination with a base.

The sulfur-containing reducing agent or agents used in the reducing composition are selected from thio l or non-thio l reducing agents .

Thio l reducing agents which can be used in the reducing composition include thio l reducing agents selected from thioglycolic acid, thio lactic acid, cysteine, cysteamine, homocystine, glutathione, thioglycerol, thiomalic acid, 2-mercaptopropionic acid, 3 -mercaptopropionic acid, thio diglyco l, 2-mercaptoethanol, dithiothreito l, thioxanthine, thio salicylic acid, thiopropionic acid, lipoic acid, N-acetylcysteine and salts thereof.

Non-thio l reducing agents which can be used in the reducing composition include in particular alkali metal or alkaline-earth metal sulfites .

The sulfur-containing reducing agent or agents used in the reducing composition are preferably thio l reducing agents, more particularly thioglyco lic acid and thiolactic acid or salts thereof, especially alkali metal, alkaline-earth metal or ammonium salts, cysteine, and mixtures thereof.

The sulfur-containing reducing agent used in the reducing composition is preferably thioglyco lic acid and its salts, especially ammonium thioglyco late.

The sulfur-containing reducing agent or agents may be present in the composition according to the invention in an amount of from 0. 1 to 50 wt%, preferably in an amount of from 1 to 20 wt%, relative to the total weight of the reducing composition.

As indicated above, the reducing composition comprises one or more fatty substances solid at room temperature.

A fatty substance in the sense of the present invention is an organic compound which is inso luble in water at ordinary room temperature (20-25 °C) and at atmospheric pressure (760 mm Hg, or 1 .013 x 10 ⁵ Pa), having a solubility in water of less than 5 %, preferably of less than 1 % and even more preferably of less than 0. 1 %. The fatty substances generally include in their structure a hydrocarbon chain containing at least 6 carbon atoms. In addition, the fatty substances are generally soluble in organic solvents under the same temperature and pressure conditions, for instance chloroform, ethanol, benzene, liquid petrolatum or decamethylcyclopentasiloxane .

The fatty substances, furthermore, are not (poly)oxyalkylenated and not (poly)glycerolated. In other words, the fatty substances do not include in their structure an ethylene oxide or glycerol or propylene glycol unit.

By so lid fatty substance is meant, in the sense o f the present invention, a fatty substance which is not liquid at room temperature (20-25 °C) and at atmospheric pressure (760 mm Hg, or 1 .013 x 10 ⁵ Pa), more particularly a compound which is solid or a compound which has a viscosity o f greater than 2 Pa. s at a shear rate of I s ^{" 1} under the aforementioned conditions .

The so lid fatty substances used in the reducing composition in accordance with the invention have a melting temperature of greater than room temperature, preferably a melting temperature of greater than or equal to 40°C, more preferably from 46 to 95 °C .

The fatty substances so lid at room temperature may be selected from fatty alcoho ls, fatty acid esters and/or fatty alcohol esters, mineral, vegetable or animal waxes, fatty amides, silicones, solid fatty ethers and mixtures thereof.

Solid fatty alcoho ls suitable for the implementation o f the invention are selected more particularly from alcoho ls conforming to the formula (I) below.

where R ¹ denotes a saturated linear C 16 - C 30 alkyl radical.

Examples include cetyl alcohol, stearyl alcoho l and a mixture thereo f (cetylstearyl alcoho l) . More particularly, the non-liquid fatty alcoho l is cetylstearyl alcoho l.

The non-liquid fatty acid esters and/or fatty alcoho l esters include, in particular, so lid esters obtained from C9 - C26 fatty acids and from C9 - C26 fatty alcoho ls. These esters include octyldodecyl behenate, isocetyl behenate, cetyl lactate, stearyl octanoate, octyl octanoate, cetyl octanoate, decyl oleate, myristyl stearate, octyl palmitate, cetyl palmitate, octyl pelargonate, octyl stearate, alkyl myristates such as cetyl, myristyl or stearyl myristate, and hexyl stearate.

The wax or waxes are preferably non-silicone waxes and are selected in particular from mineral waxes such as paraffin wax, ozokerite, vegetable waxes such as olive wax, rice wax, hydrogenated jojoba wax, carnauba wax, candelilla wax and alfa wax, or absolute flower waxes such as essential wax of blackcurrant flower, sold by Bertin (France), and animal waxes such as beeswax or modified beeswaxes (cerabellina).

Solid amides that may be mentioned include ceramides. Ceramides or ceramide analogues, such as the glycoceramides which can be used in the compositions according to the invention, are known per se and are natural or synthetic mo lecules which may conform to the general formula (II) below:

R ₃ CHOH— CH— CH ₂ OR ₂

NH

C =O

^Rl (Π)

wherein:

- Ri denotes a saturated or unsaturated, linear or branched akyl radical derived from C 14 - C30 fatty acids, it being possible for this radical to be substituted by a hydroxyl group in alpha position, or a hydroxyl group in omega position esterified by a saturated or unsaturated C 16 - C30 fatty acid;

- R ₂ denotes a hydrogen atom or a (glycosyl)n, (galactosyl)m or sulfogalactosyl radical, in which n is an integer from 1 to 4 and m is an integer from 1 to 8 ; - R ₃ denotes a C15-C26 hydrocarbon radical which is saturated or unsaturated in alpha position, it being possible for this radical to be substituted by one or more C1-C14 alkyl radicals;

with the proviso that in the case of natural ceramides or glycoceramides, R ₃ may also denote a C15-C26 alpha-hydroxyalkyl radical, the hydroxyl group being optionally esterified by a C16-C30 alpha-hydroxy acid.

Ceramides preferred in the context of the present invention are those described by Downing in Arch. Dermatol., Vol. 123, 1381-1384, 1987, or those described in French patent FR 2673 179.

The ceramide or ceramides more particularly preferred according to the invention are the compounds for which Ri denotes a saturated or unsaturated alkyl derived from C16-C22 fatty acids, R2 denotes a hydrogen atom, and R ₃ denotes a saturated C ₁₅ linear radical.

Such compounds are, for example:

- N-linoleoyldihydrosphingosine,

- N-oleoyldihydrosphingosine,

- N-palmitoyldihydrosphingosine,

- N-stearoyldihydrosphingosine,

- N-behenoyldihydrosphingosine,

or mixtures of these compounds.

More preferably still, ceramides are used for which Ri denotes a saturated or unsaturated alkyl radical derived from fatty acids, R2 denotes a galactosyl or sulfogalactosyl radical, and R3 denotes a -CH=CH-(CH ₂ )i2-CH ₃ group.

Other waxes or waxy raw materials that can be used according to the invention are, in particular, polyethylene waxes or polyolefin waxes in general.

The solid silicones in accordance with the invention may take the form of waxes or of resins. They may be organically modified.

The organopolysiloxane resins which can be used in accordance with the invention are crosslinked siloxane systems containing the following units: R ₂ Si0 ₂ /2 , Rs SiO i/2 , RSi0 _3/2 and Si0 _4/2

in which R represents an alkyl possessing 1 to 16 carbon atoms. Among these products, those that are particularly preferred are those in which R denotes a C i -C ₄ lower alkyl group , more particularly methyl.

Mention may be made, among these resins, of the product sold under the name Dow Corning 593 or those sold under the names Silicone Fluid S S 4230 and S S 4267 by the company General Electric, which are silicones of dimethyl/trimethylsiloxane structure.

Mention may also be made o f the resins of the trimethylsiloxysilicate type, sold in particular under the names X22- 4914, X21 -5034 and X21 -5037 by the company Shin-Etsu.

Organically mo dified silicones include polyorganosiloxanes containing alkoxy groups, such as the product sold under the name Abil Wax® 2428 , 2434 and 2440 by the company Go ldschmidt.

The non-liquid fatty ethers are selected from dialkyl ethers and in particular dicetyl ether and distearyl ether, alone or as a mixture.

The fatty substances solid at room temperature that are used in the cosmetic composition according to the invention are preferably selected from fatty alcoho ls, esters o f fatty acids and o f fatty alcoho ls, and mixtures thereo f.

The fatty substances are more preferably selected from cetyl alcoho l, stearyl alcohol, cetylstearyl alcohol, cetyl palmitate, and mixtures thereof.

More preferably still, the so lid fatty substances are selected from linear, saturated fatty alcoho ls containing from 12 to 30 carbon atoms, and more particularly from cetyl alcoho l, stearyl alcohol and mixtures thereof.

The fatty substance or substances solid at room temperature may be present in the reducing composition in accordance with the present invention in a total amount of from 0. 1 to 30 wt%, preferably in a total amount of from 1 to 20 wt%, and more preferably in a total amount of from 2 to 15 wt%, relative to the total weight of the composition. According to one preferred embodiment, the fatty substance or substances solid at room temperature may be present in the reducing composition in accordance with the present invention in a total amount of from 4 to 30 wt% and more preferably in a total amount of from 4.5 wt% to 20 wt%, relative to the total weight of the reducing composition.

As indicated above, the reducing composition further comprises one or more cationic surfactants.

Cationic surfactants used in the reducing composition may be selected from salts o f optionally polyoxyalkylenated primary, secondary or tertiary fatty amines, quaternary ammonium salts, and mixtures thereof.

The cationic surfactants used in the reducing composition are preferably quaternary ammonium salts .

Quaternary ammonium salts include especially, for examp le :

- those corresponding to the general formula (III) below :

in which the radicals Rs to Rn , which may be identical or different, represent a linear or branched aliphatic radical comprising from 1 to 30 carbon atoms, or an aromatic radical such as aryl or alkylaryl, with at least one of the radicals Rs to Rn denoting a linear or branched alkyl radical comprising from 10 to 30 carbon atoms, and X- denoting an organic or inorganic anion. The aliphatic radicals may include heteroatoms such as, in particular, oxygen, nitrogen, sulfur and halogens. The aliphatic radicals are selected for example from C i _3 o alkyl, C i _3 o alkoxy, polyoxyalkylene (C ₂ -C ₆ ), C i _3 o alkylamide, alkyl(C i 2-C22)amidoalkyl(C2- C6) and C i _3 o hydroxyalkyl radicals; X is an anion selected from the group of halides, phosphates, acetates, lactates, alkyl(C ₂ -Ce)sulfates and alkyl- or alkylaryl-sulfonates . Among the quaternary ammonium salts of formula (III), preference is firstly given to tetraalkylammonium chlorides such as, for example, dialkyldimethylammonium or alkyltrimethylammonium chlorides in which the alkyl radical comprises approximately from 12 to 22 carbon atoms, more particularly behenyltrimethylammonium, distearyldimethylammonium, cetyltrimethylammonium, and benzyl- dimethylstearylammonium chlorides, or else, secondly, to palmitylamidopropyltrimethylammonium chloride or stearamidopropyldimethyl(myristyl acetate)-ammonium chloride, which is sold under the name Ceraphyl ^® 70 by the company Van Dyk.

- quaternary ammonium salts of imidazoline, such as, for example, those of formula (IV) below:

in which Ri ₂ represents an alkenyl or alkyl radical comprising from 8 to 30 carbon atoms, derived for example from tallow fatty acids, R13 represents a hydrogen atom, a C ₁ -C ₄ alkyl radical or an alkenyl or alkyl radical comprising from 8 to 30 carbon atoms, R14 represents a C ₁ -C ₄ alkyl radical, R15 represents a hydrogen atom or a C ₁ -C ₄ alkyl radical, X ^" is an anion selected from the group of halides, phosphates, acetates, lactates, alkyl sulfates and alkyl- or alkylaryl-sulfonates. Preferably, Ri ₂ and R13 denote a mixture of alkenyl or alkyl radicals comprising from 12 to 21 carbon atoms, for example derived from tallow fatty acids, R14 denotes a methyl radical and R15 denotes a hydrogen atom. A product of this kind is sold for example under the name Rewoquat ^® W 75 by the company Rewo;

- quaternary diammonium or triammonium salts, particularly of formula (V) below: 2+

R I

R ₁₆ — N- (CH ₂ ) ₃ — N— R 21 2X ^"

R, R 20

(V)

in which formula (V):

Ri6 denotes an alkyl group comprising approximately from 16 to 30 carbon atoms, which is optionally hydroxylated and/or interrupted with one or more oxygen atoms;

Ri7 is selected from hydrogen, an alkyl group comprising from 1 to 4 carbon atoms or a group -(CH ₂ )3-N ⁺ (Ri6a)(Ri7a)(Ri8a), X ^" ;

Ri6a, Ri7a, Ri8a, Ri8, Ri9, R ₂ o and R ₂ 1 , which may be identical or different, are selected from hydrogen and an alkyl group comprising from 1 to 4 carbon atoms; and

X ^" , which may be identical or different, represent an organic or inorganic anionic counterion, such as that selected from halides, acetates, phosphates, nitrates, alkyl(Ci-C4) sulfates, alkyl(Ci-C4)- or alkyl(Ci-C ₄ )aryl-sulfonates, more particularly methyl sulfate and ethyl sulfate.

Compounds of this kind are, for example, Finquat CT-P, available from the company Finetex (Quaternium 89), and Finquat CT, available from the company Finetex (Quaternium 75);

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

in which formula (VI):

R ₂₂ is selected from Ci-C ₆ alkyl groups and Ci-Cc hydroxyalkyl or Ci-C ₆ dihydroxyalkyl groups, R23 is selected from:

O

- the group ²⁶ ,

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

- hydrogen atom,

R25 is selected from:

O

R

the group 28 linear or branched, saturated or unsaturated Ci-C ₆ hydrocarbon groups R29,

- hydrogen atom,

R24, R26 and R28, which are identical or different, are selected from linear or branched, saturated or unsaturated C7-C21 hydrocarbon groups;

r, s and t, which are identical or different, are integers from 2 to 6,

rl and tl, which are identical or different, are equal to 0 or 1, with r2+rl=2r and tl+t2=2t,

y is an integer ranging from 1 to 10,

x and z, which are identical or different, are integers from 0 to 10,

X ^" represents an organic or inorganic anionic counterion, with the proviso that the sum x + y + z equals from 1 to 15, that, when x is 0, then R ₂₃ denotes R27 and that, when z is 0, then R ₂₅ denotes R29.

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

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

Advantageously, the sum x + y + z has a value from 1 to 10. When R23 is an R27 hydrocarbon group, it may be long and may have from 12 to 22 carbon atoms, or may be short and may have from 1 to 3 carbon atoms.

When R ₂ 5 is an R ₂ hydrocarbon group, it preferably has 1 to 3 carbon atoms .

Advantageously, R ₂₄ , R26 and R ₂ 8 , which are identical or different, are selected from linear or branched, saturated or unsaturated C n -C _{2 1} hydrocarbon groups, and more particularly from linear or branched, saturated or unsaturated C n -C _{2 1} alkyl and alkenyl groups .

Preferably, x and z, which are identical or different, are equal to 0 or 1 .

Advantageously, y is 1 .

Preferably, r, s and t, which are identical or different, are 2 or 3 , and more particularly they are 2.

The anionic counterion X ^" is preferably a halide, such as chloride, bromide or iodide; a alkyl(C i -C ₄ ) sulfate or a alkyl(C i -C ₄ )- or alkyl(C i -C ₄ )aryl-sulfonate . It is possible, however, to use methanesulfonate, phosphate, nitrate or tosylate, an anion derived from organic acid such as acetate or lactate, or any other anion compatible with the ester-functional ammonium.

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

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

- R ₂₂ denotes a methyl or ethyl group,

- x and y are equal to 1 ,

- z is equal to 0 or 1 ,

- r, s and t are equal to 2,

- R ₂ 3 is selected from:

O

p

the group ²⁶

methyl, ethyl or C i ₄ -C ₂₂ hydrocarbon groups, a hydrogen atom,

- R25 is selected from:

O the group ^R28 ^

a hydrogen atom,

- R ₂ 4 , R26 and R ₂ 8 , which may be identical or different, are selected from linear or branched, saturated or unsaturated C _{1 3} -C _{1 7} hydrocarbon groups, and preferably from linear or branched, saturated or unsaturated C _{1 3} -C _{1 7} alkyl and alkenyl groups .

Advantageously, the hydrocarbon radicals are linear.

Mention may be made, for examp le, among the compounds o f formula (VI), of diacyloxyethyldimethylammonium, diacyloxyethylhydroxyethylmethylammonium,

monoacyloxyethyldihydroxyethylmethylammonium,

triacyloxyethylmethylammonium and monoacyloxyethylhydroxyethyldimethylammonium salts, especially the chloride or the methyl sulfate, and mixtures of these compounds. The acyl groups preferably have 14 to 1 8 carbon atoms and originate more particularly from a vegetable oil such as palm oil or sunflower oil. When the compound contains a plurality o f acyl groups, these groups may be identical or different.

These products are obtained, for example, by direct esterification o f triethano lamine, triisopropanolamine, an alkyldiethano lamine or an alkyldiisopropanolamine, which are optionally oxyalkylenated, with fatty acids or with fatty acid mixtures of plant or animal origin, or by transesterification of the methyl esters thereo f. This esterification is fo llowed by quaternization by means o f an alkylating agent such as an alkyl halide, preferably methyl or ethyl halide, a dialkyl sulfate, preferably dimethyl or diethyl sulfate, methyl methanesulfonate, methyl para-toluenesulfonate, glycol chlorohydrin or glycerol chlorohydrin. Such compounds are so ld, for example, under the names Dehyquart® by the company Henkel, Stepanquat® by the company Stepan, Noxamium® by the company Ceca, Rewoquat® WE 1 8 by the company Rewo-Witco .

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

It is also possible to use the ammonium salts containing at least one ester function that are described in patents US-A-4874554 and US-A-4137 1 80.

Use may be made o f the behenoyl- hydroxypropyltrimethylammonium chloride available from Kao under the name Quatarmin BTC 13 1 .

Preferably, the ammonium salts containing at least one ester function contain two ester functions.

Among the quaternary ammonium salts containing at least one ester function that can be used, it is preferred to use dipalmitoylethylhydroxyethylmethylammonium salts.

The cationic surfactants used in the reducing composition are preferably selected from quaternary ammonium salts o f formula (III) and quaternary ammonium salts comprising at least one ester function, especially those selected from those corresponding to the formula (VI) .

The cationic surfactants used in the composition are preferably selected from behenyltrimethylammonium, distearyldimethylammonium, cetyltrimethylammonium and benzyldimethylstearylammonium salts, and especially the chlorides, or else, alternatively, from palmitylamidopropyltrimethylammonium or stearamidopropyldimethyl(myristyl acetate)-ammonium salts and especially the chlorides .

The cationic surfactant used in the reducing composition is more preferably selected from the salts of formula (III) . More preferably still, the cationic surfactant is cetyltrimethylammonium chloride or behenyltrimethylammonium chloride.

The cationic surfactants used in the reducing composition of the present invention may be present in the reducing composition in an amount of from 0. 1 wt% to 30 wt%, more preferably from 0.5 % to 20%, preferably from 1 wt% to 10 wt%, relative to the total weight of the reducing composition.

According to one preferred embodiment of the invention, the weight ratio o f the total amount of fatty substance(s) so lid at room temperature, on the one hand, to the total amount of cationic surfactant(s), on the other, is less than or equal to 2.5 , the weight ratio preferably being between 0. 1 and 2.5 and more preferably being between 1 and 2.5.

As indicated above, the reducing composition further comprises two or more than two nonionic surfactants selected from polyoxyalkylenated fatty alcoho ls having an ethylene oxide unit number of greater than or equal to 10 and a difference in HLB (hydrophilic-lipophilic balance) of greater than or equal to 2 for at least two of them.

In other words, the polyoxyalkylenated fatty alcohols having an ethylene oxide unit number of greater than or equal to 10 are selected such that in the reducing composition there are at least two compounds o f this type, exhibiting a difference in HLB of greater than or equal to 2.

The HLB (hydrophilic-lipophilic balance) in the sense o f Griffin is defined in the scientific article J. Soc. Cosm. Chem. 1954 (vo lume 5), pages 249-256.

The po lyoxyalkylenated nonionic surfactants present in the reducing composition are selected from (poly)oxyalkylenated fatty alcoho ls comprising at least 10 oxyethylene groups, preferably a number of oxyethylene groups of from 10 to 200, more preferably a number of oxyethylene groups o f from 10 to 150. The fatty chain o f the fatty alcoho l is acyclic and comprises at least 6 carbon atoms in its structure.

In other words, the fatty alcoho l o f the po lyoxyalkylenated nonionic surfactant used in the composition according to the invention is an acyclic alcoho l comprising at least 6 carbon atoms in its structure.

The nonionic surfactants are preferably selected from oxyethylenated fatty alcoho ls in which the fatty chain of the fatty alcoho l is C 8 - C30 , preferably C 1 0 - C22 , more preferably C 1 6 - C22 , more particularly C _{1 8} , which are saturated or unsaturated, linear or branched and comprise at least 10 oxyethylene groups, such as, for example, the adducts of ethylene oxide with lauryl alcohol, especially those comprising from 10 to 100 oxyethylene groups and more particularly those comprising from 10 to 50 oxyethylene groups (Laureth- 10 to Laureth-50 in CTFA nomenclature); the adducts of ethylene oxide with behenyl alcoho l, especially those comprising from 10 to 100 oxyethylene groups and more particularly those comprising from 10 to 30 oxyethylene groups (Beheneth- 10 to Beheneth-30 in CTFA nomenclature); the adducts of ethylene oxide with cetearyl alcohol (mixture of cetyl alcoho l and stearyl alcoho l), especially those comprising from 1 0 to 1 00 oxyethylene groups (Ceteareth- 10 to Ceteareth- 100 in CTFA nomenclature); the adducts of ethylene oxide with cetyl alcohol, especially those comprising from 10 to 100 oxyethylene groups and more particularly those comprising from 10 to 45 oxyethylene groups (Ceteth- 10 to Ceteth-45 in CTFA nomenclature); the adducts of ethylene oxide with stearyl alcohol, especially those comprising from 10 to 100 oxyethylene groups (Steareth- 10 to Steareth- 100 in CTFA nomenclature); the adducts of ethylene oxide with isostearyl alcoho l, especially those comprising from 10 to 50 oxyethylene groups (Isosteareth- 10 to Isosteareth-50 in CTFA nomenclature); the adducts of ethylene oxide with decyl alcoho l, especially that comprising 10 oxyethylene groups (Deceth- 1 0 in CTFA nomenclature); the adducts of ethylene oxide with o leyl alcoho l, especially those comprising from 10 to 150 oxyethylene groups and more particularly those comprising from 10 to 106 oxyethylene groups (Oleth-10 to Oleth-106 in CTFA nomenclature); adducts of ethylene oxide with isocetyl alcohol comprising from 10 to 30 oxyethylene groups (for example Isoceteth- 10, Isoceteth-15, Isoceteth-20 and Isoceteth-25) and mixtures thereof.

In one embodiment of the invention the oxyethylenated fatty alcohol is saturated.

In another embodiment of the invention the oxyethylenated fatty alcohol is linear.

According to one embodiment, use is made more particularly of the adducts of ethylene oxide with stearyl alcohol, especially those comprising from 10 to 100 oxyethylene groups (Steareth-10 to Steareth-100 in CTFA nomenclature).

The reducing composition preferably comprises at least two oxyethylenated C8-C30, preferably C12-C22, more particularly C16-C22, especially C ₁₈ , fatty alcohols, having a difference in HLB of greater than or equal to 2, with an ethylene oxide unit number of from 10 to 100.

According to one embodiment, the reducing composition comprises two oxyethylenated C8-C30 fatty alcohols comprising at least 10 oxyethylene groups and having a difference in HLB of greater than or equal to 2.

According to a further embodiment, the reducing composition comprises three oxyethylenated C8-C30 fatty alcohols comprising at least 10 oxyethylene groups, subject to the proviso that at least 2 of said nonionic surfactants exhibit a difference in HLB of greater than or equal to 2.

Fatty alcohols comprising at least 10 oxyethylene groups may be present in the reducing composition in a total amount of from 0.1 to 30 wt%, preferably in an amount from 0.3 to 20%, more preferably from 1 to 10 wt%, relative to the total weight of the reducing composition.

According to one preferred embodiment of the invention, the fatty alcohols comprising at least 10 oxyethylene groups may be present in a total amount of greater than or equal to 1 .5 wt%, ranging preferably from 1 .5 wt% to 30 wt%, more preferably from 1 .5 wt% to 20 wt%, more preferably from 1 .5 wt% to 10 wt%, relative to the total weight of the reducing composition.

According to a first embodiment, the reducing composition comprises one or more thio l reducing agents, one or more fatty substances solid at room temperature and selected from fatty alcoho ls, one or more cationic surfactants, two or more than two nonionic surfactants selected from polyoxyalkylenated fatty alcoho ls having an ethylene oxide unit number of greater than or equal to 10 , with the proviso that at least two of said polyoxyalkylenated fatty alcohols having an ethylene oxide unit number of greater than or equal to 1 0 exhibit a difference in HLB of greater than or equal to 2.

The cationic surfactants are preferably selected from those of formula (III) .

According to a further embodiment, the reducing composition comprises one or more thio l reducing agents, one or more fatty substances solid at room temperature and selected from fatty alcoho ls, fatty acid esters and/or fatty alcohol esters, mineral, vegetable or animal waxes, fatty amides, silicones, solid fatty ethers and mixtures thereo f, one or more cationic surfactants selected from quaternary ammonium salts o f formula (III) , two or more than two nonionic surfactants selected from polyoxyalkylenated fatty alcoho ls having an ethylene oxide unit number of greater than or equal to 10 , with the proviso that at least two of said polyoxyalkylenated fatty alcohols having an ethylene oxide unit number of greater than or equal to 10 exhibit a difference in HLB of greater than or equal to 2.

The fatty substances are preferably selected from fatty alcoho ls.

The cationic surfactants are preferably selected from quaternary ammonium salts and preferably from the compounds o f formula (III) .

According to yet another embodiment, the reducing composition comprises one or more thio l reducing agents, one or more fatty substances solid at room temperature and selected from fatty alcoho ls, one or more cationic surfactants selected from quaternary ammonium salts, especially those of formula (II), two or more than two nonionic surfactants selected from oxyethylenated fatty alcoho ls having an ethylene oxide unit number of greater than or equal to 1 0, with the proviso that at least two of said polyoxyalkylenated fatty alcoho ls having an ethylene oxide unit number o f greater than or equal to 1 0 exhibit a difference in HLB of greater than or equal to 2.

In accordance with this embodiment, the oxyethylenated fatty alcoho ls are preferably selected from adducts of ethylene oxide with C 8 - C 30 fatty alcoho ls having from 10 to 100 oxyethylene groups .

In accordance with the aforementioned embodiments, the reducing composition preferably comprises one or more fragrances, these being an odorant compound or a mixture of odorant compounds . Odorant compounds and fragrances include those described in the article "Perfumes" by William L. Schreiber on pp . 171 -201 in Volume 1 8 of the fourth edition o f Encyclopedia of chemical techno logy, Kirk Othmer, 1996.

The reducing composition o f the invention generally comprises water or a mixture of water and one or more customary organic so lvents .

The suitable organic solvents include more particularly non- aromatic monoalcoho ls such as ethyl alcoho l and isopropyl alcoho l, or polyo ls or polyo l ethers such as, for example, ethylene glyco l monomethyl, monoethyl and monobutyl ethers, propylene glycol or its ethers such as, for example, propylene glycol monomethyl ether, butylene glyco l, dipropylene glyco l and also diethylene glycol alkyl ethers such as, for example, diethylene glycol monoethyl ether or monobutyl ether, or else po lyo ls such as glycero l. Polyethylene glyco ls and po lypropylene glycols, and mixtures of all these compounds, can also be used as so lvent.

The above-described organic solvents, if present, represent commonly from 0. 1 to 15 wt%, more preferably from 0.5 to 5 wt%, relative to the total weight of the composition. The H o f the reducing composition according to the invention is generally from 7 to 10 and preferably from 7.5 to 9.5. It may be adjusted by addition either of alkaline agents such as aqueous ammonia, monoethanolamine, diethanolamine, triethanolamine, isopropanolamine, 2-methyl-2-amino- 1 -propanol, propane- 1 ,3 - diamine, guanidine, arginine, an ammonium or alkali metal carbonate or bicarbonate, an organic carbonate such as guanidine carbonate, or else an alkali metal hydroxide, or of acidifying agents such as hydrochloric acid, acetic acid, lactic acid, boric acid, citric acid and phosphoric acid.

The composition according to the invention preferably comprises at least one alkaline agent.

The reducing composition may more particularly comprise aqueous ammonia, ammonium bicarbonate or one or more alkano lamines, especially monoethano lamine.

The cosmetic composition in accordance with the invention may further comprise one or more additional cosmetic agents.

The additional cosmetic agent or agents may be selected from anionic, cationic, nonionic, amphoteric and zwitterionic polymers or mixtures thereof; anionic surfactants, nonionic surfactants different from the nonionic surfactants of the invention, or amphoteric surfactants; pigments; thickeners; antioxidants; penetrants; sequestrants; fragrances; buffers; dispersants; reduction regulators such as dithio acids, such as dithiodiglycolic acid and salts thereo f; film-formers; preservatives; stabilizers; and opacifiers .

The reducing composition according to the invention preferably comprises one or more fragrances .

Of course, those skilled in the art will take care to select this or these optional additional compound(s) such that the advantageous properties intrinsically associated with the composition in accordance with the invention are not, or are not substantially, adversely affected by the envisaged addition(s) . The above adjuvants are generally present in an amount, for each o f them, of between 0 and 20 wt%, relative to the total weight of the composition.

The reducing composition may preferably comprise one or more thickeners, which may be selected from associative or non- associative, nonionic or cationic, zwitterionic, amphoteric, or anionic, natural or synthetic polymeric thickeners, and from non-polymeric thickeners such as, for example, an electrolyte or a sugar.

Polymeric thickeners include, for example, cellulosic thickeners, for example hydroxyethyl cellulose, hydroxypropyl cellulo se and carboxymethyl cellulose, guar gum and its derivatives, for example hydroxypropyl guar, sold by the company Rhodia under the name Jaguar HP 105 , gums of microbial origin, such as xanthan gum and scleroglucan gum, synthetic polymeric thickeners such as crosslinked homopolymers of acrylic acid or of acryl- amidopropanesulfonic acid, for example Carbomer, nonionic, anionic or amphoteric associative po lymers, such as the po lymers so ld under the names Pemulen TR1 or TR2 by the company Goodrich, Salcare SC90 by the company Allied Co lloids, Aculyn 22, 28 , 33 , 44 or 46 by the company Rohm & Haas, and Elfacos T210 and T212 by the company Akzo .

The cosmetic composition preferably comprises one or more additional thickeners selected from nonionic thickeners, more particularly polysaccharides .

The reducing composition is preferably present in the form of a cream.

The reducing composition according to the invention may advantageously have a viscosity at 25 °C of from 2 to 20 Pa. s, more preferably of from 2 to 15 Pa.s and more preferably still of from 2.5 to 10 Pa. s.

The viscosity o f the reducing composition is determined at 25 °C by means o f a Rheomat 1 80 rotary viscometer (Jean Lamy SA) equipped with a spindle 3 (MS r3) or spindle 4 (MS r4) anchor/bucket geometer with a rotary speed of 200 revolutions/minute, with use of the calibration plots supplied by the viscometer supplier.

The present invention likewise relates to a method for permanent deformation treatment of keratinous fibres, more particularly of human keratinous fibres such as the hair, which comprises performing the fo llowing steps :

(i) a reducing composition according to the invention is applied to said fibres, and the time sufficient for shaping is allowed to elapse, and

(ii) optionally, an oxidizing composition is applied to said fibres for a time sufficient to fix the shape.

The waiting time allowed to elapse fo llowing application o f the reducing composition is generally from 5 to 60 minutes, in particular from 3 to 30 minutes.

The oxidizing composition used in step (ii) of the permanent deformation method conventionally comprises one or more oxidizing agents, in general aqueous hydrogen peroxide solution, an alkali metal bromate, a persalt or a polythionate, and even more preferentially aqueous hydrogen peroxide solution.

The pH of the oxidizing composition is generally from 2 to 10, preferably from 2 to 8 , more preferably from 2 to 4.

The waiting time for the oxidizing composition is generally from 2 to 30 minutes, preferably from 5 to 15 minutes.

In particular, the reducing composition according to the invention is applied in order to reduce the disulfide links in the keratin, with the keratinous fibres being placed under mechanical tension before, during or after said application.

When a perming operation is desired, preference is given to using mechanical means such as curlers in order to place the keratinous fibres under tension, with the reducing composition according to the invention being applied before, during or after the hair-shaping means, preferably after.

The reducing composition in accordance with the present invention may be applied to wetted hair which has been wound beforehand onto rollers with a diameter of from 2 to 30 mm. The reducing composition may also be applied in line with the winding o f the hair. Generally speaking, the reducing composition is then allowed to act for a time o f 5 to 60 minutes.

Fo llowing app lication of the reducing composition according to the invention, it is also possible to subj ect the who le hair to a heat treatment by heating at a temperature of between 30 and 250°C for all or part of the leave-on time. In practice, this operation may be performed using a hairstyling hood, a hairdryer, a round or flat iron, an infrared ray dispenser and other heating appliances.

In particular it is possible, both as heating means and as hair- shaping means, to use heating tongs at a temperature of between 60 and 230°C, and preferably between 120 and 230°C, the heating tongs being used after the step of interim rinsing following the application of the reducing composition.

The curler itself may be a heating means.

The oxidizing composition for reforming the keratin disulfide bonds is then applied to the rolled-up or unrolled hair, generally for a leave-on time o f from 2 to 30 minutes .

In the case of a hair relaxing or straightening process, the reducing composition is app lied to the hair, and the hair is then subj ected to mechanical deformation for fixing the hair in its new shape, by means o f a hair straightening operation, with a wide-toothed comb, with the back o f a comb, by hand or with a brush. The leave-on time is generally from 5 to 60 minutes.

This application may also be fo llowed with a heating treatment, especially using an iron.

The straightening of the hair may also be performed, totally or partly, using a heating iron at between 60 and 230°C and preferably between 120 and 230° C .

The oxidizing composition as defined above is then applied, and is left to act generally for around 2 to 30 minutes, after which the hair is optionally rinsed thoroughly, generally with water. After the permanent deformation treatment method has been performed, the keratinous fibres are optionally rinsed.

Preferably, the keratinous fibres impregnated with the oxidizing composition are rinsed thoroughly with water. The keratinous fibres may optionally be separated, before or after, from the means needed to keep them under tension.

The keratinous fibres may then be washed with a shampoo, rinsed and dried or left to dry.

The permanent deformation treatment method is preferably a method for smoothing of keratinous fibres, more particularly of human keratinous fibres such as the hair.

The example that follows serves to illustrate the invention without, however, being limiting in nature.

EXAMPLE

I . Reducing compositions The reducing compositions (A), (B) and (C) are prepared from the ingredients indicated as a weight percentage of product as it is in the table below:

Cationic surfactant sold under the name Genamin CTAC 25 by C lariant ' Fatty alcohol sold under the name Ecorol 68/50P by Ecogreen Oleochemicals

^ Nonionic surfactant sold under the name Brij S20-SO-(AP) by Croda, HLB = 15.3

^ Nonionic surfactant sold under the name Brij SIOO-PA-(SG) by Croda, HLB = 18.5

⁽⁵⁾ Nonionic surfactant sold under the name Brij SIO-SO-(SG) by Croda, HLB = 12.4

^ Nonionic surfactant sold under the name Brij C2-SO-(AP) by Croda, HLB = 5.3

⁽⁷⁾ Reducing agent sold by Bruno Bock

^ Chelating agent sold under the name Versenex 80 by Dow Chemical II. Physicochemical properties

The viscosity of reducing compositions (A), (B) and (C) is measured at 25°C using a Rheomat 180 rotary viscometer equipped with a spindle 3 (MS r3) or spindle 4 (MS r4) anchor/bucket geometer. The value read at the rotary speed of 200 revolutions/minute and after a time of 10 minutes is expressed in deviation units (DU) and converted to Cps (mPa.s) on the basis of supplier data.

The results are collated in the following table: Table A: Viscosity of reducing compositions after addition of fragrances, in Cps (mPa.s)

A B C

comparative comparative inventive

Viscosity 1060 1535 5725 with fragrance Table B : Viscosity o f reducing compositions before addition o f fragrances, in Cps (mPa. s)

Comparative compositions (A) and (B) are found to have a final viscosity which is lower than that of composition (C), and the viscosity o f composition (C) is found to vary less during the manufacturing process than the viscosity of compositions (A) and (B) . III . Permanent deformation method

The reducing composition (C) is applied to hair which has been washed beforehand, over the entirety o f the hair.

After a waiting time o f 30 minutes, the hair is rinsed with water. The oxidizing composition "Fixateur X Tenso Moisturist" from L ' Oreal is then applied to the whole of the hair. After a waiting time of 10 minutes, the hair is rinsed.

The hair is observed to have a very smooth appearance and a very pleasant feel.