Keratin fiber straightening process

Abstract

The present invention relates to a process for straightening / straightening keratin fibres, in particular hair, comprising i) the application to the keratin fibres of a composition comprising at least one alkanolamine, at least one compound chosen from amino acids and their derivatives, and at least one alkali metal, alkaline earth metal or ammonium hydroxide, ii) a rinsing step, iii) optionally a drying step, and iv) a straightening / straightening step.

Description

Title of the invention: Process for straightening keratin fibres

[0001] The present invention relates to a process for straightening / straightening keratin fibres, in particular hair, comprising i) the application to the keratin fibres of a composition comprising at least one alkanolamine, at least one compound chosen from amino acids and their derivatives, and at least one alkali metal, alkaline earth metal or ammonium hydroxide, ii) a rinsing step, iii) optionally a drying step, and iv) a straightening / straightening step.

[0002] In the hair care field, consumers want to have compositions that allow them to make a temporary change to their hair, while aiming for a good hold of the effect achieved. In general, it is desired that the change persists after shampooing for at least 15 days, or even more depending on the nature of the said change.

[0003] Heat treatments are generally used to modify the shape of the hair, in a lasting way. These treatments allow a visual modification of the appearance of the hairstyle, combining a reduction in the degree of frizz, a reduction in the overall volume of the hair, a reduction in frizz, a gain in discipline, a smoother visual appearance, a substantial gain in shine, resistance to humidity and heat to maintain the hairstyle all day long.

[0004] Furthermore, this type of treatment has the advantage of facilitating daily hair care, with the use of fewer care products, in particular rinse-off treatments such as conditioners or masks, or leave-in treatments such as serums, treatment creams or balms, disciplining mousses. Hair drying is made easier, with a significantly shorter blow-drying time and a reduction in the daily use of flat clips, both in time and intensity. This thus makes it possible to limit the risks of damage to the hair by combined factors of mechanical and thermal stress.

[0005] Several technologies are combined with these heat treatments. A first technology is based on the use of compositions based on thiolated reducers. These technologies require strict compliance with the application conditions recommended by the suppliers, particularly in terms of quantity and pause time. In addition, they may be contraindicated on overly sensitized hair and may not be compatible with the application on the same day of other treatments such as coloring or bleaching. They are also malodorous.

[0006] Another technology is based on the use of acid-based compositions, and in particular on the use of glyoxylic acid. Thus, application WO2011 / 104282 has proposed a new process for smoothing in a semi- permanent hair treatment, consisting of applying an alpha-ketoacid solution to the hair for 15 to 120 minutes, then drying and finally straightening the hair with an iron at a temperature of around 200°C. The alpha-ketoacid used is preferably glyoxylic acid.

[0007] However, it has been found that glyoxylic acid may not be well tolerated, particularly when the scalp is sensitive and / or irritated. Its volatility, amplified by the use of heat from the iron, may also be problematic. Furthermore, the compositions of the prior art may damage the hair and / or alter its color.

[0008] Treatments have also been proposed using a composition comprising a base combined with a heat treatment to straighten the hair. Such treatments make it possible to obtain good relaxation of the curls but can lead to alterations of the hair fiber. Document EP1837010 describes in particular a straightening / straightening method using a composition comprising soda and a heat treatment. Document WO2007 / 144707 describes a straightening / straightening method using a composition comprising a non-hydroxylated base such as monoethanolamine, ethylenediamine, combined with a heat treatment. Document WO2009 / 117344 also describes a straightening / straightening method using a composition comprising a non-hydroxylated base and a protein denaturant combined with a heat treatment.

[0009] To limit the alterations of hair fibers, it has also been proposed to use compositions comprising weak acids at alkaline pH combined with a heat treatment. Document WO2010 / 049434 describes, for example, a straightening / straightening process in which a composition comprising a dicarboxylic acid such as maleic acid and a heat treatment is applied. Such treatments are not always satisfactory in terms of results and / or persistence.

[0010] There is still a need to develop a hair treatment method, in particular a straightening / straightening method which makes it possible to straighten / straighten and / or reduce the frizz of the hair in an effective and lasting manner while limiting the damage to the hair.

[0011] Thus, the present invention relates to a process for smoothing and / or straightening keratin fibers, in particular human keratin fibers such as hair, comprising successively: i) a step of applying to said keratin fibres at least one composition comprising at least one alkanolamine, at least one compound chosen from amino acids and their derivatives and at least one alkali metal, alkaline earth metal or ammonium hydroxide, ii) at least one step of rinsing the keratin fibres, iii) optionally a step of drying said keratin fibers, iv) a step of smoothing / straightening the keratin fibers during which at least one heat treatment is applied to said fibers.

[0012] Such a process makes it possible to obtain rapid smoothing of keratin fibers from a single composition and is persistent after several shampoos. The process of the invention is therefore both simple to implement and its effect is long-lasting over time.

[0013] The method of the invention makes it possible to minimize the risks of degradation or sensitization of keratin fibers.

[0014] The method of the invention also allows modulation of the relaxation of the loops as a function of the heat input.

[0015] The method of the invention can also be implemented on all types of hair, even very sensitized hair, while retaining, or even improving, the cosmetic qualities of the fiber, such as shine, smooth feel, and ease of styling (reduction in volume and frizz) as well as their natural appearance with loose, individualized and light hair, as well as a natural feel.

[0016] The method according to the invention makes it possible in particular to improve the cosmetic feel of the hair, in particular by making it smoother to the touch. In addition, the method does not release any unpleasant odor during the application of heat during the straightening / straightening step.

[0017] In the context of the present invention, the term "straightening / straightening" means a process which makes it possible to reduce the level of frizz in the hair; it also generally makes it possible to reduce the volume of the hair. The reduction in the level of frizz can go as far as completely straightening the hair.

[0018] Other characteristics and advantages of the invention will appear more clearly on reading the description and examples which follow.

[0019] In the following the expression “at least one” is equivalent to the expression “one or more”.

[0020] Alkanolamine The composition used in the process of the invention comprises at least one alkanolamine.

[0021] By alkanolamine is meant an organic amine comprising a primary, secondary or tertiary amine function, and one or more linear or branched C1-C8 alkyl groups carrying one or more hydroxyl radicals.

[0022] Particularly suitable for carrying out the invention are alkanolamines chosen from mono-, di- or tri-alkanolamines, comprising 1 to 3 hydroxyalkyl radicals, identical or not, in C1-C4.

[0023] In particular, the alkanolamine(s) are chosen from monoethanolamine (MEA), diethanolamine, triethanolamine, monoisopropanolamine, diisopro- panolamine, N,N-dimethylethanolamine, 2-amino-2-methyl-l-propanol, triiso-propanol-amine, 2-amino-2-methyl-l,3-propanediol, 3-amino-l,2-propanediol, 3-dimethylamino-l,2-propanediol, tris-hydroxymethylamino-methane and mixtures thereof.

[0024] Preferably, the alkanolamine is monoethanolamine.

[0025] Preferably, the alkanolamine(s) are present in a total content ranging from 0.5 to 15% by weight, preferably from 1 to 10% by weight, preferentially from 2 to 8% by weight, better still from 3 to 7% by weight relative to the total weight of the composition used in the process of the invention.

[0026] Preferably, the alkanolamine(s) chosen from monoethanolamine (MEA), diethanolamine, triethanolamine, monoisopropanolamine, diisopropanolamine, N,N-dimethylethanolamine, 2-amino-2-methyl-1-propanol, triisopropanolamine, 2-amino-2-methyl-1,3-propanediol, 3-amino-1,2-propanediol, 3-dimethylamino-1,2-propanediol, tris-hydroxymethylaminomethane and mixtures thereof are present in a total content ranging from 0.5 to 15% by weight, preferably from 1 to 10% by weight, more preferably from 2 to 8% by weight, better still from 3 to 7% by weight, relative to the total weight of the composition used in the process of the invention.

[0027] Preferably, the monoethanolamine is present in a total content ranging from 0.5 to 15% by weight, preferably from 1 to 10% by weight, preferentially from 2 to 8% by weight, better still from 3 to 7% by weight, relative to the total weight of the composition used in the process of the invention.

[0028] Amino acids and their derivatives The composition used in the method of the invention further comprises at least one compound chosen from amino acids and their derivatives.

[0029] The amino acid derivatives can be chosen from their betaine forms, their optical isomers, their solvates such as hydrates, and their salts, of acid or base, organic or mineral, and their mixtures.

[0030] The amino acid may be chosen from the following amino acids of formula (I) and (II), as well as their betaine forms, their optical isomers, their solvates such as hydrates, and their salts, of acid or base, organic or mineral: 0 o Q RR (I) :H) Formulas (I) and (II) in which: - R represents a hydrogen atom, a linear or branched C1-C5 alkyl group, preferably linear, said alkyl group being optionally substituted by at least one group chosen from hydroxyl, amino, -C(O)-OH, -S(O)2-OH, -C(O)-O, M+, -S(O)2-O, M+, with M+ representing a cationic counterion such as alkali metal, alkaline earth metal, or ammonium, - n is 0 or 1.

[0031] In the composition containing them, the amino acid(s) may be found in their non-ionized form (I), (II) or in their ionized or betaine form (I') or (II'): Formulas in which R represents a hydrogen atom, a linear or branched C1-C5 alkyl group, optionally substituted by a hydroxyl, amino, or carboxylate group, n is 0 or 1.

[0032] The amino acid(s) or their salt(s) may be chosen from aspartic acid, glutamic acid, asparagine, carnitine, glutamine, histidine, leucine, isoleucine, methionine, N-phenylalanine, proline, hydroxyproline, threonine, tryptophan, tyrosine, valine, glycine, alanine, serine, beta alanine, taurine, lysine, arginine and their salts, in particular sodium glycinate, sodium alanilate, sodium serinate, lithium beta alaninate, sodium taurate.

[0033] Preferably the amino acids are chosen from sulfonic amino acids, preferentially from those of formula (II), more preferentially taurine.

[0034] In particular, the composition according to the invention comprises at least one compound chosen from taurine, as well as its betaine forms, its optical isomers, its solvates such as hydrates, and its salts, of acid or base, organic or mineral, and their mixtures.

[0035] Taurine, or 2-aminoethanesulfonic acid, is an amino acid with the formula NH2-CH2-CH2-SO3H.

[0036] Taurine may be present in non-ionized form (II') or in ionized form (II”), as defined above.

[0037] Preferably, the compound(s) chosen from taurine and its derivatives are chosen from taurine and its salts, in particular sodium taurate, potassium taurate, magnesium taurate, and their mixtures, more preferably taurine.

[0038] Preferably, the compound(s) chosen from amino acids and their derivatives are present in a total content ranging from 0.5 to 15% by weight, preferably from 0.75 to 10% by weight, preferentially from 1 to 6% by weight, better still from 2 to 5% by weight relative to the total weight of the composition used in the process of the invention.

[0039] Preferably, the compound(s) chosen from sulfonic amino acids and their derivatives are present in a total content ranging from 0.5 to 15% by weight, preferably from 0.75 to 10% by weight, preferentially from 1 to 6% by weight, better still from 2 to 5% by weight relative to the total weight of the composition used in the process of the invention.

[0040] Preferably, the compound(s) chosen from taurine and its derivatives are present in a total content ranging from 0.5 to 15% by weight, preferably from 0.75 to 10% by weight, preferentially from 1 to 6% by weight, better still from 2 to 5% by weight relative to the total weight of the composition used in the process of the invention.

[0041] Preferably, taurine, its betaine forms, its optical isomers, its solvates such as hydrates, and its salts, of acid or base, organic or mineral, and their mixtures are present in a total content ranging from 0.5 to 15% by weight, preferably from 0.75 to 10% by weight, preferentially from 1 to 6% by weight, better still from 2 to 5% by weight relative to the total weight of the composition used in the process of the invention.

[0042] Preferably, potassium taurate, sodium taurate, magnesium taurate and taurine, and preferentially taurine, are present in a total content ranging from 0.5 to 15% by weight, preferably from 0.75 to 10% by weight, preferentially from 1 to 6% by weight, better still from 2 to 5% by weight, relative to the total weight of the composition used in the process of the invention.

[0043] Preferably, the weight ratio between the total content of alkanolamine(s) and the total content of compounds chosen from amino acids and their derivatives is greater than 1, preferably it is between 1.1 and 3, and more preferably between 1.2 and 2.

[0044] Preferably, the weight ratio between the total content of alkanolamine(s) and the total content of compounds chosen from sulfonic amino acids and their derivatives is greater than 1, preferably it is between 1.1 and 3, and more preferably between 1.2 and 2.

[0045] Preferably, the weight ratio between the total content of alkanolamine(s) and the total content of compounds chosen from taurine and its derivatives is greater than 1, preferably it is between 1.1 and 3, and more preferably between 1.2 and 2.

[0046] Preferably, the weight ratio between the total content of monoethanolamine and the total content of potassium taurate, sodium taurate, magnesium taurate, taurine and their mixtures is greater than 1, preferably it is between 1.1 and 3, and more preferably between 1.2 and 2.

[0047] Preferably, the weight ratio between the total monoethanolamine content and the total taurine content is greater than 1, preferably it is between 1.1 and 3, and more preferably between 1.2 and 2.

[0048] Alkali metal, alkaline earth metal or ammonium hydroxides The composition used in the method of the invention further comprises one or more alkali metal, alkaline earth metal, or ammonium hydroxides.

[0049] By alkali or alkaline earth metal hydroxide is meant a compound of formula M(OH)X in which M is a metal chosen from alkali or alkaline earth metals and x is equal to 1 or 2.

[0050] The alkali metal hydroxides may in particular be chosen from sodium hydroxide, potassium hydroxide, and mixtures thereof.

[0051] The alkaline earth metal hydroxides may in particular be chosen from magnesium hydroxide, calcium hydroxide, and mixtures thereof.

[0052] Ammonium hydroxide is the compound with the formula NH4OH.

[0053] Preferably, the alkali metal or alkaline earth metal hydroxide(s) will be used.

[0054] Preferably, the alkali metal or alkaline earth metal hydroxide(s) are chosen from alkali metal hydroxides, and mixtures thereof, preferably from sodium hydroxide, potassium hydroxide, and mixtures thereof, more preferably the alkali or alkaline earth metal hydroxide is sodium hydroxide.

[0055] Preferably, the alkali metal, alkaline earth metal or ammonium hydroxide(s) are present in a total content ranging from 0.05 to 10% by weight, preferably from 0.1 to 5% by weight, preferentially from 0.5 to 3% by weight, better still from 0.6 to 2% by weight, relative to the total weight of the composition used in the process of the invention.

[0056] Preferably, the alkali or alkaline earth metal hydroxide(s) are present in a total content ranging from 0.05 to 10% by weight, preferably from 0.1 to 5% by weight, preferentially from 0.5 to 3% by weight, better still from 0.6 to 2% by weight, relative to the total weight of the composition used in the process of the invention.

[0057] Preferably, the composition according to the invention comprises at least one alkali metal hydroxide which may be present in a total content ranging from 0.05 to 10% by weight. weight, preferably from 0.1 to 5% by weight, preferentially from 0.5 to 3% by weight, better still from 0.6 to 2% by weight, relative to the total weight of said composition used in the process of the invention.

[0058] Preferably, sodium hydroxide, potassium hydroxide, and their mixtures are present in a total content ranging from 0.05 to 10% by weight, preferably from 0.1 to 5% by weight, preferentially from 0.5 to 3% by weight, better still from 0.6 to 2% by weight, relative to the total weight of the composition used in the process of the invention.

[0059] Preferably, the weight ratio between the total alkanolamine(s) content and the total content of alkali metal, alkaline earth metal or ammonium hydroxides is greater than 1, preferably between 2 and 10, more preferably between 4 and 8.

[0060] Preferably, the weight ratio between the total alkanolamine(s) content and the total content of alkali metal and alkaline earth metal hydroxides is greater than 1, preferably between 2 and 10, more preferably between 4 and 8.

[0061] Preferably, the weight ratio between the total content of monoethanolamine and the total content of alkali metal hydroxides is greater than 1, preferably between 2 and 10, more preferably between 4 and 8.

[0062] Preferably, the weight ratio between the total content of monoethanolamine and the total content of sodium hydroxide and / or potassium hydroxide is greater than 1, preferably between 2 and 10, more preferably between 4 and 8.

[0063] Preferably, the smoothing composition, i.e. the composition used in step i) of the process of the invention, is an aqueous composition. It may in particular comprise water or water and one or more solvents.

[0064] Preferably, the water content generally ranges from 10 to 99% by weight, preferably from 30 to 95% by weight, preferentially from 40 to 90% by weight relative to the total weight of the composition.

[0065] As solvents, organic solvents are preferred. Mention may in particular be made of water-soluble solvents such as C1-C7 alcohols; mention may in particular be made of C1-C7 aliphatic monoalcohols, such as for example ethanol, or C6-C7 aromatic monoalcohols, or C2-C6 polyols, such as for example glycerin, pentylene glycol, which may be used alone or in a mixture with water.

[0066] Thickening agents The composition used in the process of the invention may also comprise one or more thickening agents.

[0067] For the purposes of the present invention, the term “thickening agent” means an agent which, by its presence in the composition, makes it possible to increase the viscosity of said composition by at least 10 cPs, preferably by at least 200 cPs, at 25°C and at a shear rate of ls-1. This viscosity can be measured using a cone / tube viscometer. plan (Haake R600 Rheometer or similar).

[0068] The thickening agent(s) may be chosen from fatty acid amides obtained from C10-C30 carboxylic acid (monoisopropanol-, diethanol- or monoethanol-amide of coconut acids, monoethanolamide of oxyethylenated alkyl ether carboxylic acid), polymeric thickeners and in particular polysaccharides, in particular cellulose polymers as described below, guar gums, gum arabic, gums of microbial origin (scleroglucan gum), crosslinked or non-crosslinked homo- and copolymers based on acrylic acid, methacrylic acid or acrylamidopropanesulfonic acid, and mixtures thereof.

[0069] According to one variant, the thickening polymer is a polysaccharide of natural or synthetic origin.

[0070] The polysaccharide polymers useful in the invention are cationic, non-ionic, anionic or amphoteric polymers, preferably non-ionic.

[0071] The term “polysaccharide polymers” means polymers with sugar units.

[0072] By sugar unit is meant, within the meaning of the present invention, a unit derived from a carbohydrate of formula CdfLO),, । or (CH2O)n which may optionally be modified by substitution, and / or by oxidation and / or by dehydration.

[0073] As sugar units, polymers useful in the invention are preferably derived from the following sugars: glucose; galactose; arabinose; rhamnose; mannose; xylose; fucose; anhydrogalactose; galacturonic acid; glucuronic acid; mannuronic acid; galactose sulfate; anhydrogalactose sulfate and fructose.

[0074] We can notably cite as polysaccharide polymers those derived from native gums such as:

[0075] a) exudates from trees or shrubs including: - gum arabic (branched polymer of galactose, arabinose, rhamnose and glucuronic acid); - gum ghatti (polymer derived from arabinose, galactose, mannose, xylose and glucuronic acid); - karaya gum (polymer derived from galacturonic acid, galactose, rhamnose and glucuronic acid); - gum tragacanth (or tragacanth) (polymer of galacturonic acid, galactose, fucose, xylose and arabinose);

[0076] b) gums derived from algae including: - agar (polymer made from galactose and anhydrogalactose); - alginates (polymers of mannuronic acid and glucuronic acid); - carrageenans and furcellerans (polymers of galactose sulfate and anhydrogalactose sulfate);

[0077] c) gums from seeds or tubers of which: - guar gum (polymer of mannose and galactose); - carob gum (polymer of mannose and galactose); - fenugreek gum (polymer of mannose and galactose); - tamarind gum (polymer of galactose, xylose and glucose); - konjac gum (polymer of glucose and mannose);

[0078] d) microbial gums including: - xanthan gum (polymer of glucose, mannose acetate, mannose / pyruvic acid and glucuronic acid); - gellan gum (polymer of partially acylated glucose, rhamnose and glucuronic acid); - scleroglucan gum (glucose polymer);

[0079] e) plant extracts including: - cellulose (glucose polymer); - starch (glucose polymer) and - inulin.

[0080] These polymers can be modified physically or chemically. Physical treatment includes, in particular, temperature.

[0081] As chemical treatments, mention may be made of esterification, etherification, amidation and oxidation reactions. These treatments make it possible to produce polymers which may in particular be non-ionic, anionic or amphoteric.

[0082] Preferably these chemical or physical treatments are applied to guar gums, carob gums, starches and celluloses.

[0083] Such non-ionic guar gums optionally modified by hydroxyalkyl groups are for example sold under the trade names JAGUAR HP8, JAGUAR HP60, JAGUAR HP 105 and JAGUAR HP120 by the company RHODIA CHIMIE.

[0084] The polysaccharide polymers may be cellulosic polymers.

[0085] Thus, the cellulose polymers can be chosen from unsubstituted celluloses including in microcrystalline form and cellulose ethers.

[0086] Among these cellulose polymers, we distinguish cellulose ethers, cellulose esters and cellulose ether esters.

[0087] Among the cellulose esters, we find inorganic cellulose esters (nitrates, sulfates or phosphates of cellulose...), organic cellulose esters (monoacetates, triacetates, amidopropionates, acetatebutyrates, acetatepropionates or acetatetrimellitates of cellulose...) and mixed organic / inorganic cellulose esters such as acetatebutyratesulfates and acetatepropionatesulfates of cellulose. Among the cellulose ether esters, we can mention phthalates hydroxypropylmethylcellulose and ethylcellulose sulfates.

[0088] Among the non-ionic cellulose ethers without a C10-C30 fatty chain, i.e. "non-associative", mention may be made of (Cl-C4)alkylcelluloses such as methylcelluloses and ethylcelluloses (for example Ethocel standard 100 Premium from DOW CHEMICAL); (poly)hydroxy(Cl-C4)alkylcelluloses such as hydroxymethylcelluloses, hydroxyethylcelluloses (for example Natrosol 250 HHR offered by AQUALON) and hydroxypropylcelluloses (for example Klucel EF from AQUALON); mixed celluloses (poly)hydroxy(Cl-C4)alkyl-(Cl-C4)alkylcelluloses such as hydroxypropylmethylcelluloses (e.g. Methocel E4M from DOW CHEMICAL), hydroxyethylmethylcelluloses, hydroxyethylethylcelluloses (e.g. Bermocoll E 481 FQ from AKZO NOBEL) and hydroxybutylmethylcelluloses.

[0089] The polysaccharide(s) according to the invention may be chosen from microbial gums.

[0090] The microbial gums may be selected from scleroglucan gums, gellan gums, pullulan gums, Curdlar gums, xanthan gums, grifolan gums, lentinan gums, Schizophyllan gums, spirulinan gums and krestin gums.

[0091] Mention may in particular be made of scleroglucan gums produced by Sclerotium rolfsii, gellan gums produced by Pseudomonas elodea or Sphingomonias, pullulan gums produced by Aureobacidium pullulens, Curdlar gums produced by alcaligenes of the Faecalis myxogenes type, xanthan gums produced by numerous organisms including Leuconostoc mesenteroides and Leuconostoc dextrantum, grifolan gums produced by Grifola frondara, lentinan gums produced by Lentinus edodes, Schizophyllan gums produced by Schizophyllum commine, spirulina gums produced by Spirulina sybsyla and krestin gums produced by Coriates versicolor.

[0092] Preferably, the thickening agent(s) are chosen from polysaccharides, preferentially from guar gums, better still from non-ionic guar gums optionally modified by hydroxyalkyl groups.

[0093] When they are present, the thickening agent(s) is or are generally present in a content ranging from 0.1 to 10% by weight and preferably from 0.5 to 5% by weight, better still from 1 to 3% by weight, relative to the total weight of the composition used in the process of the invention.

[0094] When they are present, the polysaccharide polymer(s) is or are generally present in a content ranging from 0.1 to 10% by weight and preferably from 0.5 to 5% by weight, better still from 1 to 3% by weight, relative to the total weight of the composition used in the process of the invention.

[0095] Cationic polymers The composition used in the process of the invention may also comprise one or more cationic polymers, preferably non-silicone, different from the thickening agents previously described.

[0096] The cationic polymer(s) that can be used may be chosen from associative cationic polymers, non-associative cationic polymers and mixtures thereof.

[0097] For the purposes of the present invention, the term "cationic polymer" means any polymer comprising cationic groups and / or groups which can be ionized into cationic groups. 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 to it.

[0098] The cationic polymers possibly present in the composition according to the invention can be chosen from all those already known per se as improving the cosmetic properties of the hair, namely in particular those described in patent application EP-A-337 354 and in French patents FR-2 270 846, 2 383 660, 2 598 611, 2 470 596 and 2 519 863.

[0099] The polymer(s) are chosen from non-silicone polymers.

[0100] The preferred cationic polymers are chosen from those which contain units comprising primary, secondary, tertiary and / or quaternary amine groups which can either be part of the main polymer chain or be carried by a side substituent directly linked to it.

[0101] Among the cationic polymers, mention may be made more particularly of polymers of the polyamine, polyaminoamide and polyquaternary ammonium type.

[0102] These are known products. They are notably described in French patents No. 2,505,348 or 2,542,997.

[0103] Preferably, the cationic polymer(s) used in the smoothing composition is or are chosen from the homopolymer of dimethyldiallylammonium chloride, with the INCI name Polyquaternium-6, such as the product sold under the name "Merquat 100" by the company NALCO (and its counterparts with a low weight-average molecular mass) and the copolymers of diallyldimethylammonium chloride and acrylamide, with the INCI name Polyquaternium-7, such as the products sold under the name "MERQUAT 550", "MERQUAT 7SPR".

[0104] The cationic polymer(s) used in the composition implemented according to the process of the invention may be present in a content ranging from 0.05 to 10% by weight, preferably in a content ranging from 0.1 to 5% by weight, preferentially from 0.2 to 3% by weight relative to the total weight of the composition implemented in the process of the invention.

[0105] According to a variant, the composition implemented according to the process of the invention comprises at least one thickening agent chosen from polysaccharides and at least one cationic polymer as defined previously.

[0106] Surfactants The composition used in the process of the invention may optionally also comprise one or more surfactants, preferably chosen from non-ionic surfactants and cationic surfactants.

[0107] Preferably, the composition comprises one or more surfactants, preferentially chosen from non-ionic surfactants.

[0108] Among the non-ionic surfactants, it is possible to use oxyalkylenated fatty alcohols, in particular oxyethylenated, preferably C8-C24 fatty alcohols comprising 1 to 50 moles of ethylene oxide.

[0109] When it(they) is(are) present, the total content of surfactant(s) can range from 0.1 to 20% by weight, preferably from 1 to 15% by weight, preferentially from 2 to 10% by weight relative to the total weight of the composition used in the process of the invention.

[0110] Fatty substances The composition used in the method according to the invention may also comprise one or more fatty substances.

[0111] The fatty substance(s) are preferably chosen from liquid hydrocarbons comprising more than 6 carbon atoms, C8-C30 fatty alcohols, silicones and mixtures thereof.

[0112] By way of example, liquid hydrocarbons comprising more than 6 carbon atoms may be chosen from C6 to C16 liquid hydrocarbons, the latter may be linear, branched, optionally cyclic, and preferably saturated. Mention may be made of hexane, cyclohexane, undecane, dodecane, isododecane, tridecane, isoparaffins such as isohexadecane, isodecane, and mixtures thereof.

[0113] The liquid hydrocarbons comprising more than 6 carbon atoms may also be chosen from liquid hydrocarbons comprising more than 16 carbon atoms, linear or branched, of mineral or synthetic origin, and are preferably chosen from paraffin or vaseline oils (or mineral oil), polydecenes, hydrogenated polyisobutene such as Parléam®, and mixtures thereof.

[0114] Liquid hydrocarbons comprising more than 6 carbon atoms may also be chosen from mixtures of alkanes having from 8 to 28 carbon atoms, more particularly from 15 to 28 carbon atoms, we may cite the mixtures whose INCI names are for example the following: C15-19 Alkane, C18-C21 Alkane, C21-C28 Alkane, such as for example the products Gemseal 40, Gemseal 60, Gemseal 120 marketed by Total, Emogreen L19 marketed by SEPPIC, Emogreen L15 marketed by SEPPIC, more particularly Emogreen L19 com sold by SEPPIC.

[0115] The C8-C30 fatty alcohols are preferably chosen from C8-C24 fatty alcohols, preferentially C12-C22.

[0116] The fatty alcohols can be chosen from cetyl alcohol, stearic alcohol, and their mixtures such as cetearyl alcohol.

[0117] Preferably, the composition according to the invention comprises one or more fatty substances, preferably chosen from liquid hydrocarbons comprising more than 6 carbon atoms, C8-C30 fatty alcohols, silicones and mixtures thereof, preferentially from liquid hydrocarbons comprising more than 6 carbon atoms, C8-C30 fatty alcohols, and mixtures thereof.

[0118] When it(they) is(are) present, the total fatty substance content can range from 0.1 to 20% by weight, preferably from 1 to 15% by weight, preferentially from 5 to 10% by weight relative to the total weight of the composition used in the process of the invention.

[0119] The composition used in the process according to the invention may be presented in all the galenic forms conventionally used, and in particular in the form of an aqueous, alcoholic or hydroalcoholic, or oily solution or suspension; of a solution or dispersion of the lotion or serum type; of an emulsion, in particular of liquid or semi-liquid consistency, of the O / W, W / O or multiple type; of a suspension or emulsion of soft consistency of the cream (O / W) or (W / O) type; of an aqueous or anhydrous gel, of a cream or of any other cosmetic form.

[0120] When the composition is aqueous, the pH preferably varies from 7 to 13, preferentially from 8 to 12.5, better still from 9 to 12, better still from 10 to 11.5.

[0121] Method The present invention relates to a process for smoothing and / or straightening keratin fibers, in particular hair, comprising: i) a step of applying to said keratin fibres at least one composition comprising at least one alkanolamine, at least one compound chosen from amino acids and their derivatives and at least one alkali metal, alkaline earth metal or ammonium hydroxide, ii) at least one step of rinsing said keratin fibers, iii) optionally a step of drying said keratin fibers, and iv) a step of smoothing / straightening the keratin fibers during which at least one heat treatment is applied to said fibers.

[0122] Preferably, the straightening / smoothing step is carried out at a temperature above 50°C, preferably between 80 and 250°C.

[0123] The composition according to the invention can be applied to dry or wet keratin fibers, preferably to wet fibers, said fibers having been able to be previously shampooed and / or rinsed, in particular with water, before applying said composition according to the invention.

[0124] Preferably, the composition according to the invention is applied to dry or damp hair, more preferably damp, said hair having been previously shampooed and / or rinsed, in particular with water, before application of said composition according to the invention.

[0125] Step i) may optionally be preceded by a washing step with a shampoo and / or a rinsing step, preferably with water.

[0126] The method of the invention is preferably carried out on wet keratin fibers, preferably on wet hair.

[0127] The application of the composition in step i) can be carried out by any means, such as by means of a brush or a comb or even with the fingers.

[0128] Preferably, the exposure time of the composition on the keratin fibers in step i) ranges from 5 to 90 minutes, preferably from 10 to 60 minutes, more preferably from 15 to 45 minutes.

[0129] For the purposes of the present invention, the exposure time is the contact time of the composition on the keratin fibers.

[0130] Preferably, the composition according to the invention is left to remain on the keratin fibers at room temperature.

[0131] For the purposes of the present invention, ambient temperature means a temperature varying from 20°C to 37°C.

[0132] Preferably, rinsing step ii) is a water rinse.

[0133] The rinsing step ii) can be carried out one or more times.

[0134] Preferably, the method according to the invention comprises a step of drying the keratin fibers carried out after the rinsing step ii) and before the straightening / straightening step iv).

[0135] Drying step iii) may be carried out by air drying or using at least one conventional drying means such as a hair dryer or a hood.

[0136] Preferably, the drying step iii) is carried out at a temperature below 100°C, preferably at a temperature ranging from 40 to 95°.

[0137] The straightening / straightening step iv) comprises at least one heat treatment applied to said keratin fibers. That is to say, heat is applied to said keratin fibers during the implementation of the straightening / straightening step at a temperature preferably greater than or equal to 110°C, preferably at a temperature ranging from 110°C to 280°C, more preferably ranging from 110°C to 250°C, simultaneously or sequentially with a mechanical action.

[0138] In other words, such a device may be a heating device imposing a mechanical action on the keratin fibers to produce smoothing / straightening, this mechanical action that can be implemented simultaneously or sequentially with the application of heat.

[0139] The smoothing / straightening step iv) may be implemented by at least one device imposing a mechanical action on the keratin fibers to produce the smoothing / straightening. By way of example, mention may be made of blow-drying using a brush and a hair dryer, a hair straightener, a hair straightener capable of generating steam at the time of treatment such as the Steampod© smoothing tool which makes it possible to apply steam to the fibers and then smooth them, and heating polyester films.

[0140] Preferably, the smoothing / straightening step iv) is carried out with at least one hair straightener or a hair straightener capable of generating steam on the keratin fibers, at a temperature greater than or equal to 110°C.

[0141] The heat treatment of the fibers can also be carried out using a hair dryer or a heating helmet, for example of the Climazon® blower type or an infrared heating helmet, the flattening of the fibers to obtain the smoothing being then carried out manually, for example with a comb or a brush.

[0142] Preferably, the heat treatment of step iv) is carried out at a temperature greater than or equal to 110°C, preferably at a temperature ranging from 110°C to 280°C, more preferably ranging from 110°C to 250°C.

[0143] The application of heat may vary, for example, from 5 to 30 minutes, preferably from 10 to 20 minutes.

[0144] The implementation of the method of the invention may be followed by a step of shaping the keratin fibers, for example brushing. That is to say that step iv) may be followed by a step of shaping the keratin fibers, for example brushing.

[0145] When the smoothing / straightening step is carried out using a hair straightener, it may be necessary to make several passes of the hair straightener, generally between 1 and 10 passes, preferably between 3 and 5 passes, each pass being carried out between 5 and 40 seconds. According to a particular embodiment with the hair straightener, the duration of the treatment of the lock of hair is at most 1 minute.

[0146] The method according to the invention can be implemented on sensitized or non-sensitized keratin fibers.

[0147] Preferably, the process for straightening and / or relaxing keratin fibers, in particular human keratin fibers such as hair, successively comprises: i) a step of applying to wet keratin fibres at least one composition comprising at least one alkanolamine, at least one compound chosen from taurine and its derivatives and at least one alkali or alkaline-earth metal hydroxide; the weight ratio between the total content of alkanolamine(s) and the total content of compound(s) chosen from taurine and its derivatives is greater than 1; preferably, the application time of the composition varies from 5 to 90 minutes, ii) at least one step of rinsing the keratin fibers, iii) optionally a step of drying the keratin fibers, iv) a step of smoothing / straightening the keratin fibers during which at least one heat treatment is applied to said fibers.

[0148] Preferably, in accordance with this preferred embodiment, the heat treatment varies from 110°C to 280°C, more preferably ranging from 110°C to 250°C.

[0149] Preferably, in accordance with this preferred embodiment, the alkanolamine is chosen from mono-, di- or trialkanolmines, in particular monoethanolamine.

[0150] Preferably, in accordance with this embodiment, the weight ratio between the monoethanolamine content and the total content of compound(s) chosen from taurine and its derivatives is greater than 1, preferably greater than 1.1.

[0151] The following examples serve to illustrate the invention without, however, being limiting in nature.

[0152] Examples In the following examples, all quantities are indicated as a percentage by mass of active ingredient (AI) relative to the total weight of the composition (unless otherwise stated). Example 1

[0153] a) Composition The following composition A was made from the ingredients indicated in the table below:

[0154] [Tables 1] Composition A Taurine 3.75 Monoethanolamine 5.625 Sodium hydroxide 0.875 Water Qsp 100

[0155] b) Protocol Strands of Curi Type V curly hair (2.7g) are pre-washed with shampoo. Composition A is then applied to damp hair at a rate of 1g of composition per gram of strand. A setting time of 30 minutes for the composition to remain on the strands in the open air and at room temperature is observed. The strands are rinsed with water by passing the fingers 20 times under water (method according to the invention) or not rinsed (comparative method). The strands are dried with a hairdryer and then straightened using a straightening iron at a temperature of 230°C (5 passes).

[0156] A sensory evaluation (smooth touch, ease of passage of the straightener and an evaluation of the reduction of curls are carried out at the time of straightening (tO), after 1 shampoo and after 5 shampoos.

[0157] c) Results The results are presented in the table below:

[0158] [Tables2] Evaluation Process according to the invention (with rinsing) Comparative process (without rinsing) tO Sensory evaluation Smooth touch, loose hair, easy passages with the straightener Heavy touch, significant transfer to the fingers, difficult and jerky passages with the straightener After 1 shampoo Reduction of curls Straightened hair, without curls Presence of curls and / or waves Sensory evaluation Individualized hair, smooth touch Presence of hair in clumps (the hair is less individualized) After 5 shampoos Reduction of curls Straightened hair, without curls -

[0159] The method according to the invention comprising a rinsing step between the steps of applying composition A and straightening makes it possible to obtain better relaxation of the curls, with easier passage of the straightening iron and better cosmeticity, in particular concerning the individualization of the hair, compared to the comparative method.

[0160] After 5 shampoos, the curl relaxation is maintained with the method of the invention.

[0161] The method of the invention therefore makes it possible to obtain better smoothing which is more durable over time, in particular resistant to shampooing, compared to the comparative method.

[0162] Example 2 Composition B according to the invention was produced from the ingredients indicated in the table below:

[0163] [Tables3] Composition B Quantity (% in MA) Taurine 3.75 Monoethanolamine 5.625 Sodium hydroxide 0.875 Cl3-16 isoalkane 5 Fatty alcohol 2.5 Dimethicone 0.1 Hydroxypropyl guar 1.5 Non-ionic surfactants 4 Organic solvents 10 Water Qs 100

[0164] Composition B has a pH of 10.7.

[0165] When composition B is applied according to the application protocol described above, long-lasting, odorless smoothing is obtained during the application of composition B. After 15 shampoos, the hair is still smooth, disciplined, individualized and easy to style.

Claims

Claims

1. Process for straightening and / or relaxing human keratin fibers, such as hair, comprising successively: i) a step of applying to said keratin fibers at least one composition comprising at least one alkanolamine, at least one compound chosen from amino acids and their derivatives and at least one alkali metal, alkaline earth metal or ammonium hydroxide ii) at least one step of rinsing the keratin fibers, iii) optionally a step of drying said keratin fibers, iv) a step of straightening / relaxing the keratin fibers during which at least one heat treatment is applied to said fibers.

2. Method according to the preceding claim, characterized in that the alkanolamine(s) are chosen from monoethanolamine (MEA), diethanolamine, triethanolamine, monoisopropanolamine, diisopropanolamine, N,N-dimethylethanolamine, 2-amino-2-methyl-1-propanol, triisopropanolamine, 2-amino-2-methyl-1,3-propanediol, 3-amino-1,2-propanediol, 3-dimethylamino-1,2-propanediol, tris-hydroxymethylaminomethane and mixtures thereof, preferably the alkanolamine is monoethanolamine.

3. Process according to any one of the preceding claims, characterized in that the alkanolamine(s) are present in a total content ranging from 0.5 to 15% by weight, preferably from 1 to 10% by weight, preferentially from 2 to 8% by weight, better still from 3 to 7% by weight relative to the total weight of the composition used in the process of the invention.

4. Method according to any one of the preceding claims, characterized in that the compound(s) chosen from amino acids and their derivatives are chosen from sulfonic amino acids and their derivatives, preferably from taurine and its derivatives, preferentially from taurine and its salts, better still from taurine, sodium taurate, potassium taurate, magnesium taurate, and their mixtures, more preferentially the compound chosen from amino acids and their derivatives is taurine.

5. Method according to any one of the preceding claims, characterized in that the compound(s) chosen from amino acids and their derivatives are present in a total content ranging from 0.5 to 15% by weight, preferably from 0.75 to 10% by weight, preferentially from 1 to 6% by weight, better still 2 to 5% by weight relative to the total weight of the composition used in the process of the invention.

6. Method according to any one of the preceding claims, characterized in that the alkali metal, alkaline earth metal or ammonium hydroxide(s) are chosen from alkali metal hydroxides, and mixtures thereof, preferably from sodium hydroxide, potassium hydroxide, and mixtures thereof, more preferably the alkali metal, alkaline earth metal or ammonium hydroxide is sodium hydroxide.

7. Process according to any one of the preceding claims, characterized in that the alkali metal, alkaline earth metal or ammonium hydroxide(s) are present in a total content ranging from 0.05 to 10% by weight, preferably from 0.1 to 5% by weight, preferentially from 0.5 to 3% by weight, better still from 0.6 to 2% by weight, relative to the total weight of the composition used in the process of the invention.

8. Process according to any one of the preceding claims, characterized in that the weight ratio between the total content of alkanolamine(s) and the total content of compounds chosen from amino acids and their derivatives is greater than 1, preferably between 1.1 and 3, preferentially between 1.2 and 2.

9. Method according to any one of the preceding claims, characterized in that the exposure time of the composition on the keratin fibers in step i) ranges from 5 to 90 minutes, preferably from 10 to 60 minutes, more preferably from 15 to 45 minutes.

10. Method according to any one of the preceding claims, characterized in that it comprises a step iii) of drying said keratin fibers.

11. Method according to any one of the preceding claims, characterized in that the heat treatment of step iv) is carried out at a temperature greater than or equal to 110°C, preferably at a temperature ranging from 110°C to 280°C, more preferably ranging from 110°C to 250°C.

12. Method according to any one of the preceding claims, characterized in that the heat treatment of step iv) is carried out with a hair straightener, a hair straightener capable of generating steam at the time treatment, heating polyester films, a hair dryer, a heating helmet or an infrared heating helmet.

13. Method according to any one of the preceding claims, characterized in that step i) is preceded by a washing step with a shampoo and / or a rinsing step, preferably with water.