EP2236053B2 - Method for the steam treatment of hair - Google Patents

Description

The present invention relates to a new process for treating hair fibers, in particular hair.

It is known to smooth hair fibers with straightening tweezers. These tweezers make it possible to smooth the keratin fibers at high temperature without pulling on the hair, unlike brushings. However, to obtain a good smooth appearance, it is necessary to perform several passes of the clamp, which considerably lengthens the treatment time of the hair. Furthermore, the repeated application of the flat straightening pliers can cause degradation of the hair fibers due to the application temperature of the smoothing pliers.

It is also known practice to use steam for treating the hair, this steam treatment being able to be combined with various cosmetic hair treatments. In particular, it is known in the field of styling (non-permanent shaping) a method of treating the hair which comprises the application of steam for a time of less than 2 minutes at a temperature of at least 75 ° C on keratin fibers maintained under mechanical tension and to which a particular cosmetic composition has been applied beforehand, comprising, for example, an oil, a silicone, oxidation dyes, natural dyes, direct dyes and others. We can cite as examples the documents EP 659 395 , EP 659 393 , EP 659,396 , EP 659 397 , US 2004/0000319 .

It is also known practice to treat the hair with hair straighteners delivering water vapor. However, these tweezers do not make it possible to obtain a satisfactory cosmetic effect because the heat dispensed by these tweezers is less than that dispensed by conventional smoothing tweezers. We can cite in particular the document WO 2004/002262 which describes a process using such a process, the vapor dispensed further comprising a non-volatile cosmetic shaping product.

These processes, although improving the cosmetic and visual properties of hair fibers, are long and often difficult to implement. The cosmetic effect obtained is also non-persistent on washing.

Thus, the aim of the present invention is to develop a new process for the treatment of keratin fibers which makes it possible to obtain an improvement in the cosmetic and visual properties of hair fibers with processes that are easy and quick to implement, and which are persistent. minus a wash.

This aim is achieved by the present invention, which relates to a process for treating hair fibers according to claim 1.

For a treated lock of hair fibers, the steam application step and the shaping step are not carried out simultaneously on the same portion of hair fibers, these two steps can nevertheless be implemented with the same device. configured to successively implement these two steps. Alternatively, two separate devices can be used to implement these separate steps.

The process of the present invention makes it possible in particular to obtain rapid shaping of the hair fibers while improving their cosmetic properties. Furthermore, the process of the present invention makes it possible to obtain an improvement in the cosmetic properties which is persistent after at least one wash and in the ease of application for the user.

The hair fibers treated by the process of the invention thus exhibit improved smoothness with a brighter appearance than that obtained with the process of the technique and this even in the absence of additional cosmetic active ingredients.

In the context of the present invention, the term “hair fibers” means keratin fibers such as the hair or synthetic fibers called “extensions” which are intended to be attached to the hair of a person by various means, in particular by gluing. and this in order to modify the appearance of a person's natural hair, for example, by modifying the volume, color or appearance of the hair.

The application of steam can be carried out before or after the step of shaping the hair fibers. According to a particular embodiment, the shaping of the hair fibers is carried out after the steam treatment of these hair fibers.

It is possible to obtain a very good cosmetic result after a single application of steam.

According to a particular embodiment of the invention, the quantity of steam is between 1 and 4 g / min.

According to one particular embodiment, the water vapor which is applied to the hair contains one or more cosmetic ingredients and / or active ingredients such as a perfume, a shaping or conditioning active, etc.

The application of the steam can be carried out using any apparatus known per se to generate the quantity of steam useful in the process of the invention. According to a particular embodiment, this device is portable, that is to say that the reservoir making it possible to generate the steam is in contact with the part of the device comprising the orifices for distributing the steam.

The step of shaping the hair fibers can be carried out with any type of means known in the art making it possible to obtain a temperature on the fibers of at least 50 ° C. The means for shaping the hair fibers are, for example, devices having a heating surface capable of coming into contact with the hair fibers and of applying to these fibers a tension, even slight, making it possible to smooth, style and disentangle the fibers. capillaries.

According to a particular embodiment of the process of the invention, the forming temperature is greater than 90 ° C, preferably between 90 ° C and 230 ° C, in particular between 150 and 200 ° C.

According to one variant, the shaping step is carried out by means of smoothing pliers. In particular, mention may be made of the flat smoothing pliers described in the patents. US5957140 , US5046516 , US7044139 , US5223694 , US5091629 .

Although the shaping, in particular the smoothing of the hair fibers, can be carried out several times, already very satisfactory results are obtained with a single pass of the smoothing tongs.

The process of the present invention makes it possible in particular when the application of steam is carried out before shaping, to sufficiently hydrate the fibers to reduce the degradation of the latter during the implementation of the shaping. at a temperature above 50 ° C.

When the application of steam takes place after shaping, the steam rehydrates the fibers similarly reducing the degradation of hair fibers.

Preferably, the shaping step is carried out after the steam treatment.

According to a particular embodiment, the method of the invention further comprises a step of cosmetic treatment of the hair fibers by means of a composition comprising one or more cosmetic active ingredients.

This cosmetic treatment step can be carried out before or after the application of the steam and / or before or after the shaping of the hair fibers. It should in particular be noted that this cosmetic treatment step is not carried out simultaneously with the application of the steam.

According to a first variant, the method of the invention comprises, in order, the cosmetic treatment step, followed by the application of steam and then by shaping the hair fibers.

According to a second variant, the method of the invention comprises in order the application of steam, followed by the shaping of the hair fibers, then by the cosmetic treatment step.

According to a third variant, the method of the invention comprises in order the application of steam, followed by the step of cosmetic treatment then by the step of shaping the hair fibers.

According to these two variants, the process of the invention can comprise a second stage of post-treatment or pre-treatment of the hair fibers, identical to or different from the first stage of cosmetic treatment.

The cosmetic treatment step may be a step for caring for the hair fibers, which may or may not be followed by rinsing, a step of washing the fibers, a step of shaping or controlling the shape, for example using by means of a fixing gel, a shaping mousse, a lacquer, a leave-in conditioner in the form of a cream, a permanent, semi-permanent or temporary coloring step, a permanent deformation step with by means of a reducing agent and optionally of a fixing agent, an alkaline straightening step with soda or with guanidine carbonate.

Mention may be made, as active cosmetic agents, of coloring precursors, direct dyes, silicone polymers or not, fixing or not, mineral, vegetable or synthetic oils, waxes, reducing agents, oxidants, UV filters, conditioning agents, anti-free radical agents, sequestering or stabilizing agents, antioxidants, preservatives, acidifiers, alkaline agents, perfumes, volatile or non-volatile silicones, reactive or chemically inert polymers, pigments, solid organic or mineral particles, thickeners, vitamins, plant extracts, pro-penetrating or fiber swelling agents.

By way of example, mention may in particular be made of non-polymeric, non-coloring cationic cosmetic agents containing one or more cationic units and having one or more fatty chains.

The term “non-coloring” is understood to mean not exhibiting in its structure a chromophore exhibiting absorption maximums in the visible range.

For the purposes of the present invention, the term “fatty chain” is understood to mean any hydrocarbon chain comprising at least 8 carbon atoms, preferably from 8 to 30 carbon atoms.

The cationic cosmetic agent (s) defined above can be chosen from primary, secondary, tertiary and quaternary, aliphatic or cyclic amine groups. Preferably, the amine groups are quaternary.

Thus, the cationic cosmetic agent (s) used according to the invention are generally chosen from cationic surfactants.

By way of example, mention may be made of the salts of primary, secondary or tertiary fatty amines, optionally polyoxyalkylenated; quaternary ammonium salts with a charge not included in a ring and without an ester function; quaternary imidazoline derivatives; quaternary diammonium salts; quaternary ammonium salts with ester function (s); and / or one of their mixtures.

• ceux qui présentent la formule générale (I) suivante :
  
  dans laquelle les radicaux R₁ à R₄, qui peuvent être identiques ou différents, représentent un radical aliphatique, linéaire ou ramifié, comportant de 1 à 30 atomes de carbone, ou un radical aromatique tel que aryle en C₆-C₃₀ ou alkyl(C₁-C₆)aryle(C₆-C₃₀). Les radicaux aliphatiques peuvent comporter des hétéroatomes tels que notamment l'oxygène, l'azote, le soufre, les halogènes. Les radicaux aliphatiques sont par exemple choisis parmi les radicaux alkyle, alcoxy, polyoxyalkylène(C₂-C₆), alkylamide, alkyl(C₁₂-C₂₂)amido alkyle(C₂-C₆), alkyl(C₁₂-C₂₂)acétate, hydroxyalkyle, comportant environ de 1 à 30 atomes de carbone; X est un anion choisi dans le groupe des halogénures, phosphates, acétates, lactates, alkyl(C₁-C₆)sulfates, alkyl(C₁-C₆)- ou alkyl(C₁-C₆)aryl(C₆-C₃₀)-sulfonates, De préférence R₁ et R₂ désignent un alkyle en C₁-C₄, ou un hydroxyalkyle en C₁-C₄.
• les sels d'ammonium quaternaire de l'imidazoline, comme par exemple celui de formule (II) suivante :
  
  dans laquelle R₆ représente un radical alcényle ou alkyle comportant de 8 à 30 atomes de carbone, R₇ représente un radical alkyle en C₁-C₆ ou hydroxyalkyle en C₁-C₆, X- est un anion choisi dans le groupe des halogénures, phosphates, acétates, lactates, alkyl (C₁-C₆)sulfates, alkyl(C₁-C₆)- ou alkyl(C₁-C₆)aryl(C₆-C₃₀)Sulfonates, x désignant un entier allant de 0 à 100, de préférence de 0 à 20. Comme composé de formule (II), on peut citer le Quatemium-56.
• les sels de diammonium quaternaire de formule (III) :
  
  dans laquelle R₉ désigne un radical aliphatique comportant environ de 16 à 30 atomes de carbone, R₁₀, R₁₁, R₁₂, R₁₃ et R₁₄, identiques ou différents sont choisis parmi l'hydrogène ou un radical alkyle comportant de 1 à 4 atomes de carbone, et X-est un anion choisi dans le groupe des halogénures, acétates, phosphates, nitrates et méthylsulfates. Des sels de diammonium quaternaire de formule (III) convenant à l'invention comprennent notamment le chlorure de propanesuif diammonium.
• les sels d'ammonium quaternaire contenant au moins une fonction ester, par exemple ceux de formule (IV) suivante :
  
  dans laquelle :
  • R₁₅ est choisi parmi les radicaux alkyles en C₁-C₆ et les radicaux hydroxyalkyles ou dihydroxyalkyles en C₁-C₆ ;
  • R₁₆ est choisi parmi :
  • le radical
    
  • les radicaux R₂₀ hydrocarbonés en C₁-C₂₂ linéaires ou ramifiés, saturés ou insaturés,
  • l'atome d'hydrogène,
  • R₁₈ est choisi parmi :
  • le radical
    
  • les radicaux R₂₂ hydrocarbonés en C₁-C₆ linéaires ou ramifiés, saturés ou insaturés,
  • l'atome d'hydrogène,
  • R₁₇, R₁₉ et R₂₁, identiques ou différents, sont choisis parmi les radicaux hydrocarbonés en C₇-C₂₁, linéaires ou ramifiés, saturés ou insaturés;
  • n, p et r, identiques ou différents, sont des entiers valant de 2 à 6 ;
  • y est un entier valant de 1 à 10 ;
  • x et z, identiques ou différents, sont des entiers valant de 0 à 10 ;
  • X- est un anion simple ou complexe, organique ou inorganique.

Quaternary ammonium salts with a charge not included in a cycle and without an ester function are for example:

• those which have the following general formula (I):
  
  in which the radicals R ₁ to R ₄ , which may be identical or different, represent an aliphatic radical, linear or branched, comprising from 1 to 30 carbon atoms, or an aromatic radical such as C ₆ -C ₃₀ aryl or alkyl (C ₁ -C ₆ ) aryl (C ₆ -C ₃₀ ). The aliphatic radicals can contain heteroatoms such as in particular oxygen, nitrogen, sulfur and halogens. The aliphatic radicals are for example chosen from alkyl, alkoxy, polyoxy (C ₂ -C ₆₎ alkylene, alkylamide, (C ₁₂ -C ₂₂₎ alkyl amido (C ₂ -C ₆₎ alkyl (C ₁₂ -C ₂₂ ) acetate, hydroxyalkyl, having about 1 to 30 carbon atoms; X is an anion selected from the group of halides, phosphates, acetates, lactates, alkyl (C ₁ -C ₆ ) sulfates, alkyl (C ₁ -C ₆ ) - or alkyl (C ₁ -C ₆ ) aryl (C ₆ - C ₃₀ ) -sulfonates, Preferably R ₁ and R ₂ denote a C ₁ -C ₄ alkyl, or a C ₁ -C ₄ hydroxyalkyl.
• quaternary ammonium salts of imidazoline, such as, for example, that of the following formula (II):
  
  wherein R ₆ represents an alkenyl or alkyl radical comprising from 8 to 30 carbon atoms, R ₇ represents an alkyl radical C ₁ -C ₆ alkyl or hydroxy C ₁ -C ₆ alkyl, X- is an anion selected from the group of halides, phosphates, acetates, lactates, alkyl (C ₁ -C ₆ ) sulphates, alkyl (C ₁ -C ₆ ) - or alkyl (C ₁ -C ₆ ) aryl (C ₆ -C ₃₀ ) sulphonates, x denoting an integer ranging from 0 to 100, preferably from 0 to 20. As compound of formula (II), mention may be made of Quatemium-56.
• quaternary diammonium salts of formula (III):
  
  in which R ₉ denotes an aliphatic radical comprising approximately from 16 to 30 carbon atoms, R ₁₀ , R ₁₁ , R ₁₂ , R ₁₃ and R ₁₄ , which are identical or different, are chosen from hydrogen or an alkyl radical comprising from 1 to 4 carbon atoms, and X- is an anion selected from the group of halides, acetates, phosphates, nitrates and methylsulphates. Quaternary diammonium salts of formula (III) suitable for the invention include in particular propanesulfdiammonium chloride.
• quaternary ammonium salts containing at least one ester function, for example those of the following formula (IV):
  
  in which :
  • R ₁₅ is selected from alkyl C ₁ -C ₆ hydroxyalkyl or dihydroxyalkyl radicals C ₁ -C ₆ alkyl;
  • R ₁₆ is chosen from:
  • The radical
    
  • linear or branched, saturated or unsaturated C ₁ -C ₂₂ hydrocarbon radicals R _20,
  • the hydrogen atom,
  • R ₁₈ is chosen from:
  • The radical
    
  • linear or branched, saturated or unsaturated _{C 1} -C ₆ hydrocarbon-based radicals R _22,
  • the hydrogen atom,
  • R ₁₇ , R ₁₉ and R ₂₁ , identical or different, are chosen from C ₇ -C ₂₁ hydrocarbon radicals, linear or branched, saturated or unsaturated;
  • n, p and r, identical or different, are integers having a value from 2 to 6;
  • y is an integer from 1 to 10;
  • x and z, identical or different, are integers having a value from 0 to 10;
  • X- is a simple or complex, organic or inorganic anion.

The R ₁₅ alkyl radicals can be linear or branched and more particularly linear.

Preferably, R ₁₅ denotes a methyl, ethyl, hydroxyethyl or dihydroxypropyl radical and more particularly a methyl or ethyl radical.

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

When R ₁₆ , is a _{hydrocarbon radical R 20} , it may be long and have 12 to 22 carbon atoms or short and have 1 to 3 carbon atoms.

When R ₁₈ is an R ₂₂ hydrocarbon radical, it preferably has 1 to 3 carbon atoms.

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

Advantageously, y is equal to 1.

Preferably, n, p and r, which are identical or different, are equal to 2 or 3 and even more particularly are equal to 2.

The anion is preferably a halide. (chloride, bromide or iodide) or an alkylsulphate more particularly methylsulphate. However, it is possible to use methanesulfonate, phosphate, nitrate, tosylate, an anion derived from organic acid such as acetate or lactate or any other anion compatible with the ammonium containing an ester function.

The anion X- is even more particularly chloride or methylsulphate.

Advantageously, the hydrocarbon radicals are linear.

Among the quaternary ammonium salts of formula (I), preference is given, on the one hand, to tetraalkylammonium chlorides such as, for example, alkyltrimethylammonium chlorides, in which the alkyl radical contains approximately from 12 to 22 carbon atoms, in particular behenyl-trimethylammonium, cetyltrimethylammonium, benzyldimethylstearyl ammonium chlorides or, on the other hand, palmitylamidopropyltrimethylammonium chloride or stearamido-propyldimethyl (myristyl acetate) ammonium chloride marketed under the name "CERAPHYL 70 "by the company VAN DYK.

It is also possible to use the ammonium salts containing at least one ester function described in the patent. US-A-4874554 .

Quaternary ammonium salts of formula (IV) suitable for the invention include in particular dipalmitoylethyl hydroxyethylmmonium methosulfate, sold by the company STEPAN under the reference STEPANQUAT GA 90.

The preferred cationic molecules which can be used in the composition according to the invention are the compounds of formula (I) or of formula (IV).

Cetyl trimethyl ammonium chloride will be preferred.

As explained previously, the cationic molecule (s) can also be chosen from cationic proteins.

The cationic cosmetic agent (s) advantageously represent from 0.1% to 10% by weight of the total weight of the composition, with the proviso that if the cationic cosmetic agent is a tetraalkylammonium salt containing only one fatty chain, it either present in a content greater than or equal to 1% by weight relative to the total weight of the composition. Preferably, the cationic cosmetic agent (s) used in the invention, whatever their nature, represent from 1 to 10%, better still from 1 to 5%, by weight of the total weight of the composition.

According to a particular embodiment, when the cationic cosmetic agent (s) comprises two fatty chains, it does not contain any amide function.

By way of example, mention may be made, as cosmetic agent useful in the process of the invention, of non-coloring cationic polymers, not derived from a sugar or from a silicone, having a cationic charge density greater than 1.5. meq / g.

The charge density can be determined according to the Kjedahl method. It is generally measured at a pH of the order of 3 to 9.

Preferably, the cationic polymers used in the present invention exhibit a cationic charge density of less than 10 meq / g.

The term “cationic polymer” is understood to mean any polymer containing cationic groups and / or groups which can be ionized into cationic groups.

The term “non-coloring” is understood to mean not having in its structure a chromophore exhibiting a maximum absorption in the visible range.

The term “non-derivative of a sugar or a silicone” is understood to mean not comprising in its structure a sugar unit (mono, oligo or polysaccharide) or a unit containing one or more silicon atoms.

The cationic polymers which can be used in accordance with the present invention can be chosen from all those already known per se as improving the cosmetic properties of hair treated with detergent compositions, namely in particular those described in the patent application. EP-A-0337354 and in French patent applications FR-A-2270846 , 2383660 , 2598611 , 2470596 and 2519863 .

The preferred cationic polymers are chosen from those which contain units comprising primary, secondary, tertiary and / or quaternary amine groups which can either form part of the main polymer chain, or be carried by a side substituent directly linked thereto.

The cationic polymers used have a weight average molecular mass greater than 10 ⁵ , preferably greater than 10 ⁶ and better still between 10 ⁶ and 10 ⁸ .

Preferably, the cationic polymers are not polyurethanes.

Among the cationic polymers which can be used according to the invention, there may be mentioned more particularly polymers of the polyamine, polyaminoamide and polyquaternary ammonium type. These are known products.

1. (1) les homopolymères ou copolymères dérivés d'esters ou d'amides acryliques ou méthacryliques et comportant au moins un des motifs de formules suivantes:
   
   
   dans lesquelles:
   • R₁ et R₂, identiques ou différents, représentent un atome d'hydrogène ou un groupe alkyle ayant de 1 à 6 atomes de carbone, et de préférence un groupe méthyle ou éthyle ;
   • R₃, identiques ou différents, désignent un atome d'hydrogène ou un groupe CH₃ ;
   • les symboles A, identiques ou différents, représentent un groupe alkyle, linéaire ou ramifié, comportant de 1 à 6 atomes de carbone, de préférence 2 ou 3 atomes de carbone, ou un groupe hydroxyalkyle comportant de 1 à 4 atomes de carbone ;
   • R₄, R₅, R₆, identiques ou différents, représentent un groupe alkyle ayant de 1 à 18 atomes de carbone ou un groupe benzyle, et de préférence un groupe alkyle ayant de 1 à 6 atomes de carbone ;
   • X désigne un anion dérivé d'un acide minéral ou organique tel qu'un anion méthosulfate ou un halogénure comme le chlorure ou le bromure.
     Les copolymères de la famille (1) peuvent contenir en outre un ou plusieurs motifs dérivant de comonomères pouvant être choisis dans la famille des acrylamides, méthacrylamides, diacétone-acrylamides, acrylamides et méthacrylamides substitués sur l'atome d'azote par des groupes alkyle inférieur (C₁-C₄), des groupes dérivés des acides acryliques ou méthacryliques ou de leurs esters, de vinyllactames tels que la vinylpyrrolidone ou le vinylcaprolactame, d'esters vinyliques.
     Ainsi, parmi ces copolymères de la famille (1), on peut citer :
     • les copolymères d'acrylamide et de méthacrylate de diméthylaminoéthyle quaternisé au sulfate de diméthyle ou avec un halogénure de diméthyle,
     • les copolymères d'acrylamide et de chlorure de méthacryloyloxyéthyltriméthyl-ammonium décrits, par exemple, dans la demande de brevet EP-A-080976 ,
     • les copolymères d'acrylamide et de méthosulfate de méthacryloyloxyéthyl-triméthylammonium,
     • les copolymères vinylpyrrolidone/acrylate ou méthacrylate de dialkylaminoalkyle quaternisés ou non. Ces polymères sont décrits en détail dans les brevets français 2077143 et 2393573 ,
     • les terpolymères méthacrylate de diméthylaminoéthyle/ vinylcaprolactame/vinylpyrrolidone,
     • les copolymères vinylpyrrolidone/méthacrylamidopropyl-di-méthylamine,
     • les copolymères vinylpyrrolidone/méthacrylamide de diméthylaminopropyle quaternisé, et
     • les polymères réticulés de sels de méthacryloyloxyalkyl(C₁-C₄) trialkyl(C₁-C₄)ammonium tels que les polymères obtenus par homopolymérisation du diméthylaminoéthylméthacrylate quaternisé par le chlorure de méthyle, ou par copolymérisation de l'acrylamide avec le diméthylaminoéthylméthacrylate quaternisé par le chlorure de méthyle, l'homo ou la copolymérisation étant suivie d'une réticulation par un composé à insaturation oléfinique, en particulier le méthylène bis acrylamide. On peut plus particulièrement utiliser un copolymère réticulé acrylamide/chlorure de méthacryloyloxyéthyl triméthylammonium (20/80 en poids) sous forme de dispersion contenant 50% en poids dudit copolymère dans de l'huile minérale. Cette dispersion est commercialisée sous le nom de « SALCARE^® SC 92 » par la Société CIBA. On peut également utiliser un homopolymère réticulé du chlorure de méthacryloyloxyéthyl triméthylammonium contenant environ 50 % en poids de l'homopolymère dans de l'huile minérale ou dans un ester liquide. Ces dispersions sont commercialisées sous les noms de « SALCARE^® SC 95 » et « SALCARE^® SC 96 » par la Société CIBA.
2. (2) Les polymères constitués de motifs pipérazinyle et de groupes divalents alkylène ou hydroxyalkylène à chaînes droites ou ramifiées, éventuellement interrompues par des atomes d'oxygène, de soufre, d'azote ou par des cycles aromatiques ou hétérocycliques, ainsi que les produits d'oxydation et/ou de quaternisation de ces polymères. De tels polymères sont notamment décrits dans les brevets français 2 162 025 et 2 280 361 .
3. (3) Les polyaminoamides solubles dans l'eau, préparés en particulier par polycondensation d'un composé acide avec une polyamine ; ces polyaminoamides peuvent être réticulés par une épihalohydrine, un diépoxyde, un dianhydride, un dianhydride non saturé, un dérivé bis-insaturé, une bis-halohydrine, un bis-azétidinium, une bis-haloacyldiamine, un bis-halogénure d'alkyle ou encore par un oligomère résultant de la réaction d'un composé bifonctionnel réactif vis-à-vis d'une bis-halohydrine, d'un bis-azétidinium, d'une bis-haloacyldiamine, d'un bis-halogénure d'alkyle, d'une épilhalohydrine, d'un diépoxyde ou d'un dérivé bis-insaturé ; l'agent réticulant étant utilisé dans des proportions allant de 0,025 à 0,35 mole par groupement amine du polyaminoamide ; ces polyaminoamides peuvent être alkylés ou s'ils comportent une ou plusieurs fonctions amines tertiaires, quaternisées. De tels polymères sont notamment décrits dans les brevets français 2252840 et 2368508 .
4. (4) Les dérivés de polyaminoamides résultant de la condensation de polyalkylènes-polyamines avec des acides polycarboxyliques, suivie d'une alkylation par des agents bifonctionnels. On peut citer, par exemple, les polymères acide adipique/dialkylaminohydroxyalkyl-dialkylènetriamine dans lesquels le groupe alkyle comporte de 1 à 4 atomes de carbone et désigne de préférence un groupe méthyle, éthyle, propyle, et le groupe alkylène comporte de 1 à 4 atomes de carbone, et désigne de préférence le groupe éthylène. De tels polymères sont notamment décrits dans le brevet français 1 583 363 .
   Parmi ces dérivés, on peut citer plus particulièrement les polymères acide adipique/diméthylaminohydroxypropyl-diéthylène-triamine.
5. (5) Les polymères obtenus par réaction d'une polyalkylène-polyamine comportant deux groupements amine primaire et au moins un groupement amine secondaire, avec un acide dicarboxylique choisi parmi l'acide diglycolique et les acides dicarboxyliques aliphatiques saturés ayant de 3 à 8 atomes de carbone. Le rapport molaire entre la polyalkylène-polylamine et l'acide dicarboxylique étant compris entre 0,8 : 1 et 1,4 : 1 ; le polyaminoamide en résultant étant amené à réagir avec l'épichlorhydrine dans un rapport molaire d'épichlorhydrine par rapport au groupement amine secondaire du polyaminoamide, compris entre 0,5 : 1 et 1,8 : 1. De tels polymères sont notamment décrits dans les brevets américains 3 227 615 et 2 961 347.
6. (6) Les cyclopolymères d'alkyldiallylamine ou de dialkyldiallylammonium tels que les homopolymères ou copolymères comportant, comme constituant principal de la chaîne, des motifs répondant aux formules (Ia) ou (Ib) :
   
   
   • dans lesquelles k et t sont égaux à 0 ou 1, la somme k + t étant égale à 1 ; R₁₂ désigne un atome drhydrogène ou un groupe méthyle ; R₁₀ et R₁₁ indépendamment l'un de l'autre, désignent un groupement alkyle ayant de 1 à 6 atomes de carbone, un groupement hydroxyalkyle dans lequel le groupement alkyle a de préférence 1 à 5 atomes de carbone, un groupement amidoalkyle inférieur (C₁-C₄), ou alors R₁₀ et R₁₁ peuvent désigner conjointement avec l'atome d'azote auquel ils sont rattachés, des groupements hétérocycliques, tels que pipéridinyle ou morpholinyle ; Y^- est un anion tel que bromure, chlorure, acétate, borate, citrate, tartrate, bisulfate, bisulfite, sulfate, phosphate. Ces polymères sont notamment décrits dans le brevet français 2 080 759 et dans son certificat d'addition 2 190 406 .
   • R₁₀ et R₁₁, indépendamment l'un de l'autre, désignent de préférence un groupement alkyle ayant de 1 à 4 atomes de carbone.
     Parmi les polymères définis ci-dessus, on peut citer plus particulièrement l'homopolymère de diméthyldiallyl-ammonium notamment le chlorure de diméthyldiallylammonium vendu sous la dénomination "MERQUAT^® 100" par la société NALCO (et ses homologues de faibles masses moléculaires moyenne en poids), les copolymères de chlorure de diallyldiméthylammonium et d'acrylamide commercialisés sous la dénomination "MERQUAT^® 550" et les copolymères de diallyldiméthylammonium et d'acide acrylique tels que le "MERQUAT^® 295" commercialisé par la société NALCO.
7. (7) Les polymères de diammonium quaternaire par exemple ceux contenant des motifs récurrents répondant à la formule (II) suivant:
   
   dans laquelle :
   • R₁₃, R₁₄, R₁₅ et R₁₆, identiques ou différents, représentent des groupes aliphatiques, alicycliques ou arylaliphatiques contenant de 1 à 20 atomes de carbone ou des groupes hydroxyalkylaliphatiques inférieurs, ou bien R₁₃, R₁₄, R₁₅ et R₁₆, ensemble ou séparément, constituent avec les atomes d'azote auxquels ils sont rattachés des hétérocycles contenant éventuellement un second hétéroatome autre que l'azote, ou bien R₁₃, R₁₄, R₁₅ et R₁₆ représentent un groupe alkyle en C₁-C₆, linéaire ou ramifié, substitué par un groupement nitrile, ester, acyle, amide ou -CO-O-R₁₇-E ou -CO-NH-R₁₇-E où R₁₇ est un groupe alkylène et E un groupement ammonium quaternaire ;
   • A₁ et B₁ représentent des groupements polyméthyléniques contenant de 2 à 20 atomes de carbone, pouvant être linéaires ou ramifiés, saturés ou insaturés, et pouvant contenir, liés à ou intercalés dans la chaîne principale, un ou plusieurs cycles aromatiques, ou un ou plusieurs atomes d'oxygène, de soufre ou des groupements sulfoxyde, sulfone, disulfure, amino, alkylamino, hydroxyle; ammonium quaternaire, uréido, amide ou ester, et X^- désigne un anion dérivé d'un acide minéral ou organique tel que acétate, borate, citrate, tartrate, bisulfate, bisulfite, sulfate, phosphate, méthosulfate ou un halogénure comme le chlorure ou le bromure,
   • A₁, R₁₃ et R₁₅ peuvent former avec les deux atomes d'azote auxquels ils sont rattachés un cycle pipérazinique ; en outre, si A₁ désigne un groupe alkylène ou hydroxyalkylène linéaire ou ramifié, saturé ou insaturé, B₁ peut également désigner un groupement :
     
             -(CH₂)_n-CO-E'-OC-(CH₂)_n-
     
     dans lequel E' désigne :
     1. a) un reste de glycol de formule -O-Z-O-, où Z désigne un groupe hydrocarboné linéaire ou ramifié, ou un groupement répondant à l'une des formules suivantes :
        
                -(CH₂-CH₂-O)_x-CH₂-CH₂-
        
                -[CH₂-CH(CH₃)-O]_y-CH₂CH(CH₃)-
        
        où x et y désignent un nombre entier de 1 à 4, représentant un degré de polymérisation défini et unique ou un nombre quelconque de 1 à 4 représentant un degré de polymérisation moyen ;
     2. b) un reste de diamine bis-secondaire tel qu'un dérivé de pipérazine ;
     3. c) un reste de diamine bis-primaire de formule -NH-Y-NH-, où Y désigne un groupe hydrocarboné linéaire ou ramifié, ou bien le groupe divalent -CH₂-CH₂-S-S-CH₂-CH₂- ;
     4. d) un groupement uréylène de formule -NH-CO-NH-.
   
   De préférence, X^- est un anion tel que halogénure et notamment le chlorure ou le bromure.
   Des polymères de ce type sont notamment décrits dans les brevets français 2 320 330 , 2 270 846 , 2 316 271 , 2 336 434 et 2 413 907 et les brevets US 2 273 780 , 2 375 853 , 2 388 614 , 2 454 547 , 3 206 462 , 2 261 002 , 2 271 378 , 3 874 870 , 4 001 432 , 3 929 990 , 3 966 904 , 4 005 193 , 4 025 617 , 4 025 627 , 4 025 653 , 4 026 945 et 4 027 020 . On peut utiliser plus particulièrement les polymères qui sont constitués de motifs récurrents répondant à la formule :
   
   dans laquelle R₁₃, R₁₄, R₁₅ et R₁₆, identiques ou différents, désignent un groupe alkyle ou hydroxyalkyle ayant de 1 à 4 atomes de carbone environ, n et p sont des nombres entiers variant de 2 à 20 environ et, X^- est un anion dérivé d'un acide minéral ou organique tel que défini ci-dessus.
   Un composé de formule (III) particulièrement préféré est celui pour lequel R₁₃, R₁₄, R₁₅ et R₁₆, représentent un radical méthyle et n = 3, p = 6 et X = Cl, dénommé Hexadimethrine chloride selon la nomenclature INCl (CTFA).
8. (8) Les polymères de polyammonium quaternaire constitués de motifs de formule (IV) :
   
   dans laquelle :
   • R₁₈, R₁₉, R₂₀ et R₂₁, identiques ou différents, représentent un atome d'hydrogène ou un groupe méthyle, éthyle, propyle, β-hydroxyéthyle, β-hydroxypropyle ou -CH₂CH₂(OCH₂CH₂)_pOH, où p est égal à 0 ou à un nombre entier compris entre 1 et 6, sous réserve que R₁₈, R₁₉, R₂₀ et R₂₁ ne représentent pas simultanément un atome d'hydrogène,
   • r et s, identiques ou différents, sont des nombres entiers compris entre 1 et 6,
   • q est égal à 0 ou à un nombre entier compris entre 1 et 34,
   • X^- désigne un anion tel qu'un halogénure,
   • A désigne un radical d'un dihalogénure ou représente de préférence -CH₂-CH₂-O-CH₂-CH₂-.
     De tels composés sont notamment décrits dans la demande de brevet EP-A-122 324 .
9. (9) Les polymères quaternaires de vinylpyrrolidone et de vinylimidazole tels que par exemple les produits commercialisés sous les dénominations Luviquat^® FC 905, FC 550 et FC 370 par la société B.A.S.F.

The polymers of the polyamine, polyaminoamide, polyquaternary ammonium type, which can be used in the composition of the present invention, are those described in French patents nos ^. 2505348 and 2542997 . Among these polymers, mention may be made of:

1. (1) homopolymers or copolymers derived from acrylic or methacrylic esters or amides and comprising at least one of the units of the following formulas:
   
   
   in which:
   • R ₁ and R ₂ , identical or different, represent a hydrogen atom or an alkyl group having from 1 to 6 carbon atoms, and preferably a methyl or ethyl group;
   • R ₃ , identical or different, denote a hydrogen atom or a CH ₃ group;
   • the symbols A, which are identical or different, represent an alkyl group, linear or branched, comprising from 1 to 6 carbon atoms, preferably 2 or 3 carbon atoms, or a hydroxyalkyl group comprising from 1 to 4 carbon atoms;
   • R ₄ , R ₅ , R ₆ , identical or different, represent an alkyl group having from 1 to 18 carbon atoms or a benzyl group, and preferably an alkyl group having from 1 to 6 carbon atoms;
   • X denotes an anion derived from an inorganic 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 which can be chosen from the family of acrylamides, methacrylamides, diacetone-acrylamides, acrylamides and methacrylamides substituted on the nitrogen atom by lower alkyl groups. (C ₁ -C ₄ ), groups derived from acrylic or methacrylic acids or their esters, from vinyllactams such as vinylpyrrolidone or vinylcaprolactam, from vinyl esters.
     Thus, among these copolymers of family (1), there may be mentioned:
     • copolymers of acrylamide and of dimethylaminoethyl methacrylate quaternized with dimethyl sulfate or with a dimethyl halide,
     • the copolymers of acrylamide and of methacryloyloxyethyltrimethyl-ammonium chloride described, for example, in the patent application EP-A-080976 ,
     • copolymers of acrylamide and methacryloyloxyethyl-trimethylammonium methosulfate,
     • vinylpyrrolidone / dialkylaminoalkyl acrylate or methacrylate copolymers which may or may not be quaternized. These polymers are described in detail in French patents 2077143 and 2393573 ,
     • dimethylaminoethyl methacrylate / vinylcaprolactam / vinylpyrrolidone terpolymers,
     • vinylpyrrolidone / methacrylamidopropyl-di-methylamine copolymers,
     • quaternized vinylpyrrolidone / methacrylamide copolymers of dimethylaminopropyl, and
     • crosslinked polymers of methacryloyloxyalkyl (C ₁ -C ₄ ) trialkyl (C ₁ -C ₄ ) ammonium salts such as polymers obtained by homopolymerization of dimethylaminoethyl methacrylate quaternized with methyl chloride, or by copolymerization of acrylamide with quaternized dimethylaminoethyl methacrylate with methyl chloride, homo or copolymerization being followed by crosslinking with a compound containing olefinically unsaturated, in particular methylene bis acrylamide. It is more particularly possible to use a crosslinked acrylamide / methacryloyloxyethyl trimethylammonium chloride (20/80 by weight) copolymer in the form of a dispersion containing 50% by weight of said copolymer in mineral oil. This dispersion is sold under the name "Salcare ^® SC 92" by the company Ciba. It is also possible to use a crosslinked homopolymer of methacryloyloxyethyl trimethylammonium chloride containing about 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 the company Ciba.
2. (2) Polymers consisting of piperazinyl units and divalent alkylene or hydroxyalkylene groups with straight or branched chains, optionally interrupted by oxygen, sulfur or nitrogen atoms or by aromatic or heterocyclic rings, as well as the products of oxidation and / or quaternization of these polymers. Such polymers are in particular described in French patents. 2,162,025 and 2,280,361 .
3. (3) 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, an alkyl bis-halide or else by an oligomer resulting from the reaction of a bifunctional compound reactive with a bis-halohydrin, a bis-azetidinium, a bis-haloacyldiamine, an alkyl bis-halide, d an epilhalohydrin, 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 contain one or more tertiary amine functions, quaternized. Such polymers are in particular described in French patents. 2252840 and 2368508 .
4. (4) Polyaminoamide derivatives resulting from the condensation of polyalkylene polyamines with polycarboxylic acids, followed by alkylation with bifunctional agents. Mention may be made, for example, of adipic acid / dialkylaminohydroxyalkyl-dialkylenetriamine polymers in which the alkyl group contains from 1 to 4 carbon atoms and preferably denotes a methyl, ethyl or propyl group, and the alkylene group contains from 1 to 4 atoms. of carbon, and preferably denotes the ethylene group. Such polymers are in particular described in the French patent 1,583,363 .
   Among these derivatives, there may be mentioned more particularly the adipic acid / dimethylaminohydroxypropyl-diethylene-triamine polymers.
5. (5) Polymers obtained by reacting a polyalkylene polyamine comprising two primary amine groups and at least one secondary amine group, with a dicarboxylic acid chosen from diglycolic acid and saturated aliphatic dicarboxylic acids having from 3 to 8 carbon atoms. carbon. The molar ratio between the polyalkylene polylamine and the dicarboxylic acid being between 0.8: 1 and 1.4: 1; the resulting polyaminoamide being reacted with epichlorohydrin in a molar ratio of epichlorohydrin relative to the secondary amine group of the polyaminoamide, of between 0.5: 1 and 1.8: 1. Such polymers are in particular described in the U.S. patents 3,227,615 and 2,961,347.
6. (6) Alkyldiallylamine or dialkyldiallylammonium cyclopolymers such as homopolymers or copolymers comprising, as main constituent of the chain, units corresponding to formulas (Ia) or (Ib):
   
   
   • in which k and t are equal to 0 or 1, the sum k + t being equal to 1; R ₁₂ denotes a hydrogen atom or a methyl group; R ₁₀ and R _11, independently of one another, denote an alkyl group having 1 to 6 carbon atoms, a hydroxyalkyl group in which the alkyl group preferably has 1 to 5 carbon atoms, a lower amidoalkyl group ( C ₁ -C ₄ ), or else R ₁₀ and R ₁₁ can designate, together with the nitrogen atom to which they are attached, heterocyclic groups, such as piperidinyl or morpholinyl; Y ^- is an anion such as bromide, chloride, acetate, borate, citrate, tartrate, bisulfate, bisulfite, sulfate, phosphate. These polymers are in particular described in the French patent 2,080,759 and in its certificate of addition 2 190 406 .
   • R ₁₀ and R ₁₁ , independently of one another, preferably denote an alkyl group having from 1 to 4 carbon atoms.
     Among the polymers defined above, there may be mentioned more particularly the homopolymer of dimethyldiallyl-ammonium, in particular dimethyldiallylammonium chloride sold under the name "MERQUAT ^® 100" by the company NALCO (and its homologues of low average molecular masses by weight) , diallyldimethylammonium chloride copolymers and acrylamide sold under the name "Merquat ^® 550" and copolymers of diallyldimethylammonium and acrylic acid such as "Merquat ^® 295" sold by the company Nalco.
7. (7) Quaternary diammonium polymers, for example those containing repeating units corresponding to the following formula (II):
   
   in which :
   • R ₁₃ , R ₁₄ , R ₁₅ and R ₁₆ , identical or different, represent aliphatic, alicyclic or arylaliphatic groups containing from 1 to 20 carbon atoms or lower hydroxyalkylaliphatic groups, or alternatively R ₁₃ , R ₁₄ , R ₁₅ and R ₁₆ , together or separately, together with the nitrogen atoms to which they are attached, constitute heterocycles optionally containing a second heteroatom other than nitrogen, or else R ₁₃ , R ₁₄ , R ₁₅ and R ₁₆ represent a C _{1 alkyl group} -C ₆ , linear or branched, substituted by a nitrile, ester, acyl, amide or -CO-OR ₁₇ -E or -CO-NH-R ₁₇ -E group where R ₁₇ is an alkylene group and E a quaternary ammonium group ;
   • A ₁ and B ₁ represent polymethylene groups containing from 2 to 20 carbon atoms, which may be linear or branched, saturated or unsaturated, and which may contain, linked to or intercalated in the main chain, one or more aromatic rings, or one or more several oxygen or sulfur atoms or sulfoxide, sulfone, disulfide, amino, alkylamino, hydroxyl groups; quaternary ammonium, ureido, amide or ester, and X ^- denotes an anion derived from a mineral or organic acid such as acetate, borate, citrate, tartrate, bisulfate, bisulfite, sulfate, phosphate, methosulfate or a halide such as chloride or bromide,
   • A ₁ , R ₁₃ and R ₁₅ can form with the two nitrogen atoms to which they are attached a piperazine ring; furthermore, if A ₁ denotes a linear or branched, saturated or unsaturated alkylene or hydroxyalkylene group, B ₁ may also designate a group:
     
     - (CH ₂ ) _n -CO-E'-OC- (CH ₂ ) _n -
     
     in which E 'denotes:
     1. a) a glycol residue of formula -OZO-, where Z denotes a linear or branched hydrocarbon group, or a group corresponding to one of the following formulas:
        
        - (CH ₂ -CH ₂ -O) _x -CH ₂ -CH ₂ -
        
        - [CH ₂ -CH (CH ₃ ) -O] _y -CH ₂ CH (CH ₃ ) -
        
        where 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;
     2. b) a bis-secondary diamine residue such as a piperazine derivative;
     3. c) a bis-primary diamine residue of formula -NH-Y-NH-, where Y denotes a linear or branched hydrocarbon group, or else the divalent group -CH ₂ -CH ₂ -SS-CH ₂ -CH ₂ -;
     4. d) a ureylene group of formula -NH-CO-NH-.
   
   Preferably, X ^- is an anion such as halide and in particular chloride or bromide.
   Polymers of this type are described in particular in French patents. 2,320,330 , 2,270,846 , 2,316,271 , 2 336 434 and 2 413 907 and patents US 2,273,780 , 2,375,853 , 2 388 614 , 2 454 547 , 3,206,462 , 2 261 002 , 2 271 378 , 3,874,870 , 4,001,432 , 3 929 990 , 3 966 904 , 4,005,193 , 4,025,617 , 4,025,627 , 4,025,653 , 4,026,945 and 4,027,020 . It is possible to use more particularly polymers which consist of repeating units corresponding to the formula:
   
   in which R ₁₃ , R ₁₄ , R ₁₅ and R ₁₆ , identical or different, denote an alkyl or hydroxyalkyl group having from 1 to 4 carbon atoms approximately, n and p are whole numbers varying from 2 to 20 approximately and, X ^- is an anion derived from an inorganic or organic acid as defined above.
   A particularly preferred compound of formula (III) is that for which R ₁₃ , R ₁₄ , R ₁₅ and R ₁₆ represent a methyl radical and n = 3, p = 6 and X = Cl, called Hexadimethrine chloride according to the INCl nomenclature ( CTFA).
8. (8) Polymers of quaternary polyammonium consisting of units of formula (IV):
   
   in which :
   • R ₁₈ , R ₁₉ , R ₂₀ and R ₂₁ , identical or different, represent a hydrogen atom or a methyl, ethyl, propyl, β-hydroxyethyl, β-hydroxypropyl or -CH ₂ CH ₂ (OCH ₂ CH ₂ ) group _p OH, where p is 0 or an integer between 1 and 6, with the proviso that R ₁₈ , R ₁₉ , R ₂₀ and R ₂₁ do not simultaneously represent a hydrogen atom,
   • r and s, 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 radical of a dihalide or preferably represents -CH ₂ -CH ₂ -O-CH ₂ -CH ₂ -.
     Such compounds are in particular described in the patent application EP-A-122 324 .
9. (9) 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

Other cationic polymers which can be used in the context of the invention are polyalkyleneimines, in particular polyethyleneimines, polymers containing vinylpyridine or vinylpyridinium units, condensates of polyamines and epichlorohydrin, and quaternary polyureylenes.

According to a preferred variant, the cationic polymers which can be used according to the invention exhibit a permanent cationic charge corresponding to the presence of units comprising quaternary amine groups.

Preferably, the cationic polymers of the invention are chosen from dialkyldiallylammonium cyclopolymers and quaternary diammonium polymers of formula (II).

The cationic polymer (s) advantageously represent from 0.1 to 10%, better still from 0.2 to 8%, by weight of the total weight of the composition.

The cosmetic treatment step can be implemented from a composition in the form of a lotion, thickened or not, of a cream, of a gel, or of any other suitable form.

The compositions used are generally aqueous compositions which may contain ingredients usually used in cosmetic compositions, such as solvents, surfactants, thickeners, preservatives, perfumes or any other additive used in this type of composition.

According to a particular embodiment, the method of the invention can comprise an additional final shaping step, for example a smoothing step, in particular if the previous step is a cosmetic treatment step.

The examples which follow illustrate the process of the invention used in several cosmetic hair applications.

EXAMPLE 1

Strands of hair are washed and wrung out. Pre-drying of the hair is then carried out until about 80% drying is obtained.

On these pre-dried locks, steam is applied with a flow rate of the order of 3 g / min, this application of steam being followed by the shaping / smoothing step by means of a straightening forceps heated to minus 100 ° C. This treatment is carried out strand by strand over the entire hair.

A permanent oxidation coloring of shade 5.64 (light brown copper red from the Majirouge range) is then applied which consists in applying to the hair fibers one or more oxidation bases and one or more well-known couplers, from the field of coloring. permanent, in the presence of an oxidizing agent (hydrogen peroxide).

At the same time, the above test is carried out again but without implementing the steam application step or the shaping step under the previous conditions but by performing a smoothing with a conventional heated smoothing pliers.

It is observed that the hair treated with steam is shinier and smoother than that treated only with the conventional heated straightening clip.

After several shampoos, there is a better tenacity of the color on the hair treated with the steam.

EXAMPLE 2

To locks of washed and towel-dried hair, a reducing cream is applied with a brush comprising thioglycolic acid salts. After the exposure time, the locks are rinsed again then wrung out and pre-dried to 80% with a hair dryer.

On these pre-dried fibers, steam is applied under the conditions defined above, this application of steam being followed by the shaping / smoothing step by means of a straightening forceps heated to at least 100 ° C. This treatment is carried out strand by strand over the entire hair.

The fixative is then applied to the entire hair. After an exposure time, the locks are rinsed, drained and dried.

At the same time, the above test is carried out again but without implementing the steam application step or the shaping step under the previous conditions but by performing a smoothing with a conventional heated smoothing pliers.

It is observed that the hair treated with the process of the invention is shinier and smoother to the touch and visually. The hair is moreover markedly better straightened with the process of the invention.

After several shampoos, it is observed that the smoothing effect persists when it has been obtained with the process of the invention.

EXAMPLE 3

On washed and towel-dried locks of hair, the “thermal cement” treatment from Kerastase is applied, which is a leave-on care product comprising silicones and cationic surfactants. Pre-drying of the locks is then carried out until about 80% drying is obtained.

Steam is applied to these pre-dried locks under the conditions defined above, this application of steam being followed by the shaping / smoothing step by means of a straightening forceps heated to at least 100 ° C.

At the same time, the above test is carried out again but without implementing the steam application step or the shaping step under the previous conditions but by performing a smoothing with a conventional heated smoothing pliers.

It is observed that the locks treated according to the process of the present invention are brighter and smoother to the touch and visually. The hair is much better straightened.

After several shampoos, it is observed that the smoothing effect persists when it has been obtained with the process of the invention.

EXAMPLE 4

On washed and wrung locks of hair, a conditioner "Nutricéramide" of the brand Elsève is applied. After the exposure time, the locks are rinsed then wrung out and pre-dried to 80% with a hair dryer.

On these pre-dried locks, steam is applied under the conditions defined above, this application of steam being followed by the shaping / smoothing step by means of a straightening forceps heated to at least 100 ° C.

At the same time, the above test is carried out again but without implementing the steam application step or the shaping step under the previous conditions but by performing a smoothing with a conventional heated smoothing pliers.

It is observed that the locks treated with the process of the present invention are brighter and smoother to the touch and visually. The strands are much better smoothed.

After several shampoos, it is observed that the smoothing effect persists when it has been obtained with the process of the invention.

EXAMPLE 5

Strands of hair are washed and wrung out. Pre-drying of the hair is then carried out until about 80% drying is obtained.

On these pre-dried locks, steam is applied under the conditions defined in the present invention, this application of steam being followed by the shaping / smoothing step by means of a straightening forceps heated to at least 100 ° vs. This treatment is carried out strand by strand over the entire hair.

At the same time, the above test is carried out again but without implementing the step of applying steam by smoothing with a conventional heated smoothing pliers without applying steam.

It is observed that the hair treated with steam is shinier and smoother than that treated only with the conventional heated straightening clip.

Claims (9)

1. Method for treating hair fibres which comprises:

   the application to hair fibres of steam in an amount of less than 5 g/min,

   the shaping with a smoothing iron of these hair fibres at a temperature of between 90°C and 230°C,

   the shaping being carried out after the stage of application of steam, the method comprising a single application of steam per lock of treated hair fibres.
2. Method according to Claim 1, in which the amount of steam used is of the quantity of steam is between 1 and 4 g/min.
3. Method according to Claim 1, in which the smoothing is carried out in a single pass per treated lock of hair fibres.
4. Method according to any one of the preceding claims, in which the steam comprises one or more cosmetic active principles and/or ingredients.
5. Method according to any one of the preceding claims, additionally comprising a stage of cosmetic treatment of the hair fibres using a composition comprising one or more cosmetic active principles.
6. Method according to Claim 5, comprising, in order, the cosmetic treatment stage, followed by the stage of application of steam and then by the stage of shaping the hair fibres.
7. Method according to Claim 5, comprising, in order, the stage of application of steam, followed by the stage of shaping the hair fibres and then by the cosmetic treatment stage.
8. Method according to Claim 5, comprising, in order, the application of the steam, followed by the cosmetic treatment stage and then by the stage of shaping the hair fibres.
9. Method according to either one of Claims 5 and 6, in which the cosmetic treatment stage is selected from a stage of caring for the hair fibres, a stage of washing the fibres, a stage of shaping, a stage of permanent, semipermanent or temporary dyeing, a stage of permanent deformation using a reducing agent and optionally a fixative, and a stage of alkaline straightening with sodium hydroxide or with guanidine carbonate.