A process for treating keratin fibers using a basic pH composition comprising one or more specific polyamine compounds

Abstract

The present invention relates to a process for treating keratin fibers using a basic pH composition comprising one or more specific polyamine compounds.

Description

Title of the invention: A process for treating keratin fibers using a basic pH composition comprising one or more specific polyamine compounds Technical field of the invention

[0001] The present invention relates to a process for treating keratin fibers using a basic pH composition comprising one or more specific polyamine compounds. Context of the invention

[0002] Many people are not satisfied with the appearance of their hair, especially people with curly hair who most often seek to obtain straight hair and, conversely, those with straight hair wish to have curly hair.

[0003] In order to change the shape of hair permanently, three main types of techniques can be used.

[0004] A first technique consists, initially, of opening the disulfide bonds (-SS-) of keratin (keratocystin) using a composition containing a suitable reducing agent (reduction step). Then, after rinsing the treated hair, generally with water, the disulfide bonds are reconstituted in a second step by applying an oxidizing composition to the hair, which has been previously held under tension, for example, with curlers (oxidation step, also called fixing step), in order to ultimately give the hair the desired shape. This technique thus makes it possible to create waves (perming process) and / or straighten (or relax) hair.

[0005] The new shape imposed on the hair by such a chemical treatment is eminently durable over time and resists in particular the action of washing with water or shampoos, in contrast to simple classic techniques of temporary deformation, such as setting.

[0006] The reducing compositions for carrying out the first step generally contain, as reducing agents, sulfites, bisulfites, alkylphosphines or preferably thiols. Among the latter, particular examples include cysteine ​​and its various derivatives, cysteamine and its derivatives, thiolactic acid or thioglycolic acid, their salts as well as their esters, in particular glycerol thioglycolate.

[0007] The oxidizing compositions required for the implementation of the fixation step are most often hydrogen peroxide-based compositions.

[0008] However, such a technique is not yet entirely satisfactory. Indeed, although it proves very effective in modifying the shape of hair, it remains damaging to hair fibers, mainly due to the high levels of reducing agents used in the reducing compositions as well as the varying application times that can occur during such a process.

[0009] This technique can thus, in the long term, lead to an alteration in hair quality resulting in a decrease in its cosmetic properties, such as its vitality and shine, and a degradation of its mechanical properties, particularly its mechanical resistance, due to swelling of the hair during rinsing between the reduction and oxidation stages, which can also result in an increase in its porosity, particularly when the treated hair is already weakened, such as colored or bleached hair.

[0010] Furthermore, the use of reducing agents can lead to unsatisfactory durability for hair straightening, particularly for relaxing or backcombing hair. Finally, odor problems are very common, both with the reducing compositions used, especially those containing thiols, and with the reduced hair itself.

[0011] The second technique commonly used to achieve hair straightening or smoothing involves performing a so-called lanthionization operation, using a composition containing a base belonging to the hydroxide family. This results in the replacement of disulfide bonds (-CH2-SS-CH2-) by lanthione bonds (-CH2-S-CH2-).

[0012] Compared to the first technique described above using a reducing agent, this lanthionization technique does not require a fixation step, since the formation of lanthione bridges is irreversible.

[0013] It is therefore carried out in a single step and allows for the creation of either waves, styling, backcombing, or straightening of the hair. This technique is primarily used for styling naturally curly hair.

[0014] However, the hydroxides used in this process have the major drawback of being caustic. This causticity can, in some cases, affect the scalp, sometimes causing irritation, and also affect the condition of the hair, making it rough to the touch and much more brittle. The use of hydroxides can also, in some cases, cause discoloration of the natural hair color.

[0015] Finally, the third technique commonly used consists of combining heat and an alpha-keto acid such as glyoxylic acid. Such The process is described, for example, in application WO2011 / 104282. However, alpha keto acids, especially at high concentrations, may not be well tolerated, particularly when the scalp is sensitive and / or irritated. Their volatility, amplified by the use of heat, for example, with a curling or straightening iron, can also be problematic. Furthermore, cosmetic formulations with an acidic pH can damage hair and / or alter its color.

[0016] All these reasons, and in particular the impact of these types of treatment on the quality of the hair, represent a deterrent for users, especially for those who might be tempted to repeat such treatments at more regular intervals in order to explore the level of hair styling that suits them best.

[0017] There is therefore a real need to develop a process for the permanent deformation of keratin fibers that provides good shaping performance, including a substantial reduction in hair volume and, when the hair is curly, improved curl relaxation and / or definition. The effect obtained must be long-lasting after one or more shampoos and allow the user greater control over the desired level of styling, making it possible to repeat the process while preserving the quality and integrity of the treated keratin fibers. Ideally, such a process should eliminate the need for a flat iron. Furthermore, such a process should also use less malodorous compositions, particularly without reducing agents such as thiols.Finally, the formulation of environmentally friendly cosmetic products—that is, products whose design and development take environmental issues into account—is becoming a major concern in order to help address global challenges. It is therefore essential to offer more sustainable cosmetic processing methods that can thus respond to these environmental challenges.

[0018] The applicant has surprisingly discovered that all or part of these objectives can be achieved by the process according to the present invention. Summary of the invention

[0019] According to a first aspect, the present invention relates to a process for treating keratin fibers comprising a) the application to the keratin fibers of a composition (A) having a pH between 8 and 12.5 and comprising one or more polyamine compounds selected from the compounds of formula (I), their optical isomers, their geometric isomers, their salts, their solvates such as hydrates, and their mixtures: H2N—T—NH2 (I) Formula (I) in which T represents a divalent hydrocarbon group, linear or branched, saturated or unsaturated, preferably saturated, comprising from 4 to 22 carbon atoms, optionally substituted by an -NH2 group, the group T being substituted by one or more hydroxyl (-OH) groups and / or interrupted by one or more groups selected from -C(O)-, -NRa- or their combinations such as -NRa-C(O)- or -C(O)-NRa-, with Ra representing a hydrogen atom or a (Ci-C4)alkyl group.

[0020] According to a second aspect, the present invention relates to the composition (A) as defined above.

[0021] According to a third aspect, the present invention relates to a polyamine compound selected from the following compounds (1) and (2), their optical isomers, their salts, their solvates such as hydrates, and their mixtures: (2).

[0022] According to a fourth aspect, the present invention relates to the use of the polyamine compound(s) as defined above or of composition (A) as defined above, for the relaxation of curls and / or the smoothing of keratin fibers. Detailed description of the invention

[0023] For the purposes of the present invention, and unless otherwise indicated:

[0024] ■ By "keratin fibers" we mean fibers of human or animal origin such as such as hair, body hair, eyelashes, eyebrows, wool, angora, cashmere or fur. According to the present invention, the keratin fibers are preferably human keratin fibers, more preferably hair;

[0025] ■ By "alkyl group", we mean a monovalent, linear hydrocarbon radical or branched, saturated;

[0026] ■ By "(Cx-Cy)alkyl group" is meant an alkyl group comprising from x to y atoms of carbon;

[0027] ■ By "alkylene group", we mean a divalent, linear hydrocarbon radical or branched, saturated;

[0028] ■ By "(Cx-Cy)alkylene group" is meant an alkylene group comprising from x' to y' carbon atoms;

[0029] ■ the "solvates" represent the hydrates as well as the association with alcohols linear or branched in linear or branched Ci-C4 such as ethanol, isopropanol, n-propanol;

[0030] ■ By "reducing agent" is meant an agent capable of reducing disulfide bonds hair, such as compounds selected from thiols, alkali sulfites, hydrides and phosphines.

[0031] The expressions "at least one" and "one or more" are synonymous and can be used interchangeably.

[0032] The expressions "between ... and ...", "includes from ... to ...", "made up of ... to ...", and "ranging from ... to ..." should be understood inclusive of bounds, unless otherwise specified. Keratin fiber processing method

[0033] According to a first aspect, the present invention relates to a process for treating keratin fibers as defined above.

[0034] The process according to the present invention is preferably a process for relaxing loops and / or smoothing keratin fibers.

[0035] The applicant found, surprisingly, that the process according to the invention made it possible to obtain a smoothing of the keratin fibers of good quality and lasting at least one shampoo while preserving the quality and integrity of the keratin fibers, in particular of weakened hair.

[0036] It has also been observed that the process according to the invention makes it possible to transform the shape of the hair by making successive applications without causing significant damage to the hair fiber. The process can be repeated to increase the effects, until the desired level of straightening is achieved. However, and this constitutes an advantage of the present invention, from the very first application of the process according to the invention, even without putting tension on the hair, a substantial reduction in hair volume is observed. When the hair is curly, a loosening of the curls and / or a better definition of them are also observed. The process according to the invention also makes it possible to avoid using a flat iron.

[0037] Finally, unpleasant odors such as the odor of thiols that are released during conventional straightening processes, or that remain on straightened hair depending on the Prior art processes are much less marked or even absent when implementing the process according to the invention. Polyamine compounds

[0038] Composition (A) comprises a pH between 8 and 12.5 and comprises one or more polyamine compounds selected from compounds of formula (I), their optical isomers, their geometric isomers, their salts, their solvates such as hydrates, and their mixtures: H2N—T—NH2 (I) Formula (I) in which T represents a divalent hydrocarbon group, linear or branched, saturated or unsaturated, preferably saturated, comprising from 4 to 22 carbon atoms, optionally substituted by an -NH2 group, the group T being substituted by one or more hydroxyl (-OH) groups and / or interrupted by one or more groups selected from -C(O)-, -NRa- or their combinations such as -NRa-C(O)- or -C(O)-NRa-, with Ra representing a hydrogen atom or a (Ci-C4)alkyl group.

[0039] According to a first variant, T represents a divalent, linear or branched, saturated hydrocarbon group comprising from 4 to 22 carbon atoms, preferably from 10 to 22 carbon atoms, more preferably from 15 to 20 carbon atoms, optionally substituted by an -NH2 group, the group T being interrupted by one or more groups selected from -C(O)-, -NRa- or their combinations such as -NRa-(CO)- or -(CO)-NRa-, Ra being as defined above, preferably interrupted by one or more groups selected from -NRa-C(O)- or -C(O)-NRa-, Ra being as defined above and the group T being optionally substituted by one or more hydroxyl groups (-OH).

[0040] Preferably, according to this first variant, T represents a divalent, linear or branched, saturated hydrocarbon group comprising from 10 to 22 carbon atoms, preferably from 15 to 20 carbon atoms, optionally substituted by an -NH2 group, the T group being interrupted by 2 or 3 groups chosen from -NH-(CO)- or -(CO)-NH- and the T group being optionally substituted by one or more hydroxyl groups (-OH), in particular a hydroxyl group (-OH).

[0041] According to this first variant, the polyamine compound(s) are preferably chosen from the following compounds (1) and (2), their optical isomers, their salts, their solvates such as hydrates, and their mixtures:

[0042] According to a second variant, T represents a divalent, linear or branched, saturated hydrocarbon group comprising from 4 to 22 carbon atoms, preferably from 4 to 15 carbon atoms, more preferably from 4 to 10 carbon atoms, substituted by one or more hydroxyl groups (-OH).

[0043] According to this second variant, T is preferably uninterrupted by one or more groups chosen from -C(O)-, -NRa- or their combinations such as -NRa -C(O)- or -C(O)-NRa-, Ra being as defined previously.

[0044] Preferably, according to this second variant, T represents a branched, saturated divalent hydrocarbon group comprising 4 to 15 carbon atoms, preferably 4 to 10 carbon atoms, substituted by one or more hydroxyl groups (-OH), preferably by a hydroxyl group (-OH).

[0045] According to this second variant, the polyamine compound(s) are preferably chosen from the following compound (3), its optical isomers, its salts, its solvates such as hydrates, and mixtures thereof:

[0046] The compound of formula (3) is marketed by BLD Pharmatech Ltd. (CAS: 25441-01-4).

[0047] Preferably, the polyamine compound(s) are chosen from the following compounds (1), (2) and (3), their optical isomers, their salts, their solvates such as hydrates, and their mixtures:

[0048] More preferably, the polyamine compound(s) are chosen from compounds (1) and (2), their optical isomers, their salts, their solvates such as hydrates, and their mixtures. Polyamine compound content

[0049] Preferably, the polyamine compound(s) are present in composition (A) in a total content of at least 5% by weight, preferably from 5% to 50% by weight, more preferably from 5% to 30% by weight, relative to the total weight of composition (A). pH of the composition (A)

[0050] The pH of composition (A) is between 8 and 12.5. Preferably, the pH of composition (A) is between 8.5 and 12.5.

[0051] The pH of the composition (A) can be adjusted to the desired value by means of alkalizing agents or acidifying agents commonly used or by means of conventional buffer systems.

[0052] Acidifying agents can be chosen from mineral or organic acids such as hydrochloric acid, orthophosphoric acid, sulfuric acid, carboxylic acids such as acetic acid, tartaric acid, citric acid, lactic acid, sulfonic acids.

[0053] The alkalizing agents may be chosen from organic or mineral bases, preferably chosen from: a) ammonia or one of its salts such as ammonium chloride; b) alkanolamines in particular mono-, di- or tri-(Ci-C6)alkanolamines such as mono-, di- and triethanolamines, isopropanolamine, 2-amino-2-methyl-l-propanol (AMP), 2-amino-2-methyl-l,3-propanediol (AMPD) and 2-amino-l,3-propanediol and their derivatives; c) oxyethylenated and / or oxypropylenated (Ci-C6)alkylenediamines; d) mineral or organic hydroxides; e) basic amino acids such as arginine, lysine, omithine, citrulline and histidine; (f) silicates or metasilicates of alkali or alkaline earth metals such as sodium metasilicates; (g) carbonates and bicarbonates, particularly of primary, secondary or tertiary amine, alkali metal or alkaline earth, or ammonium; and

[0054] h) compounds other than polyamine compounds as defined above selected from the compounds of the following formula (III): Formula (HD in which:) - W represents a (Ci-C6)alkylene group possibly substituted by at least one hydroxyl group or a (Ci-C6)alkyl group and / or possibly interrupted by at least one heteroatom such as O or NRU; - Rx, Ry, Rz, Rt and Ru, identical or different, represent a hydrogen atom, or a group chosen from: (Ci-C6)alkyl, hydroxyalkyl in Ci-C6, or aminoalkyl in Cr C6.

[0055] Examples of such compounds of formula (III) include 1,3-diaminopropane, 1,3-diamino-2-propanol, spermine, spermidine.

[0056] Mineral or organic hydroxides are preferably chosen from among the hydroxides of an alkali metal, the hydroxides of an alkaline earth metal, such as sodium or potassium hydroxides, the hydroxides of a transition metal, such as the hydroxides of metals in groups III, IV, V and VI of the periodic table of elements, the hydroxides of lanthanides or actinides, quaternary ammonium hydroxides, and guanidinium hydroxide.

[0057] The hydroxide can be formed in situ such as guanidine hydroxide, formed by reaction of calcium hydroxide and guanidine carbonate.

[0058] Preferably, the organic or mineral bases are chosen from ammonia or one of its salts such as ammonium chloride, carbonates or bicarbonates such as ammonium or sodium carbonate, ammonium or sodium bicarbonate, basic amino acids such as arginine, alkanolamines such as monoethanolamine (MEA), 2-amino-2-methyl-l-propanol (AMP), 2-amino-2-methyl-l,3-propanediol (AMPD) and 2-amino-l,3-propanediol.

[0059] Preferably, the pH of composition (A) is adjusted using an alkaline buffer system.

[0060] An alkaline buffer system is typically obtained by mixing a weak base and one of its salts.

[0061] The formulation of alkaline buffer systems is well known to those skilled in the art.

[0062] More preferably, the pH of the composition (A) is adjusted using a NH4OH / NH4C1 alkaline buffer system.

[0063] Composition (A) is a cosmetic composition, i.e. which includes a cosmetically acceptable medium, i.e. a medium compatible with human keratin fibers.

[0064] According to a preferred embodiment, the composition (A) comprises water and optionally one or more polar and / or protic solvents, preferably chosen from monoalcohols having 2 to 6 carbon atoms, more preferably chosen from ethanol, propanol, n-butanol, isopropanol, isobutanol, tert-butanol, pentanol, hexanol, and mixtures thereof, even more preferably chosen from n-butanol, ethanol, and mixtures thereof, most preferably ethanol.

[0065] According to a more preferred embodiment, the composition (A) comprises water and one or more polar and / or protic solvents, preferably chosen from monoalcohols having 2 to 6 carbon atoms, more preferably chosen from ethanol, propanol, n-butanol, isopropanol, isobutanol, tert-butanol, pentanol, hexanol, and mixtures thereof, even more preferably chosen from n-butanol, ethanol, and mixtures thereof, most preferably from ethanol.

[0066] Preferably, the composition (A) comprises water in a total weight content of 5% to 95% by weight, preferably of 40% to 95% by weight, relative to the total weight of the composition (A).

[0067] When present, the polar and / or protic solvent(s) are present in composition (A) in a total weight content ranging from 0.01% to 90% by weight, preferably ranging from 0.01% to 50% by weight, relative to the total weight of composition (A).

[0068] Composition (A) preferably comprises a total content of reducing agents of less than 0.1% by weight, more preferably less than 0.01% by weight, even more preferably less than 0.001% by weight relative to the total weight of composition (A).

[0069] According to a preferred embodiment, composition (A) is free of reducing agents.

[0070] Composition (A) preferably comprises a total content of colouring agents of less than 0.1% by weight, more preferably less than 0.01% by weight, even more preferably less than 0.001% by weight relative to the total weight of composition (A).

[0071] According to a preferred embodiment, composition (A) is free of coloring agents.

[0072] By "coloring agent" is meant an oxidation dye, a direct dye or a pigment.

[0073] The term "oxidation dye" refers to an oxidation dye precursor selected from oxidation bases and couplers. Oxidation bases and couplers are slightly colored or colorless compounds which, through a condensation reaction in the presence of an oxidizing agent, give a colored species.

[0074] By "direct dye" is meant a natural and / or synthetic dye, including in the form of extract(s), distinct from oxidation dyes. These are colored compounds that diffuse superficially onto the fiber. They can be ionic or non-ionic, i.e., anionic, cationic, neutral, or non-ionic.

[0075] Composition (A) may contain additives selected from surfactants, thickeners, propellants; oils; solid fats, particularly C8-C40 esters; C8-C40 acids; C8-C40 alcohols; sunscreens; moisturizing agents; anti-dandruff agents; antioxidants; pearlescent and opacifying agents; plasticizers or coalescing agents; fillers; emulsifiers; polymers, particularly conditioning or styling polymers; perfumes; and silanes. Composition (A) may, of course, include several cosmetic ingredients listed above.

[0076] The composition (A) can thus be in any form compatible with application to keratin fibers, for example in the form of wax, paste, cream more or less fluid or thick, gel, foam, spray, lotion.

[0077] Additional features concerning the process

[0078] Composition (A) can be applied to dry or moist keratin fibers, preferably moist.

[0079] The process according to the invention can be implemented on natural keratin fibers, in particular natural hair.

[0080] The process according to the invention can also be implemented on damaged and / or sensitized keratin fibers, in particular damaged and / or sensitized hair.

[0081] By "damaged keratin fibers" is meant dry, rough, brittle, split and / or soft keratin fibers.

[0082] By "sensitized keratin fibers" is meant bleached, artificially colored, straightened and / or permed keratin fibers.

[0083] The process according to the invention can advantageously be implemented on curly, frizzy or kinky keratin fibers, in particular curly, frizzy or kinky hair.

[0084] The bath ratio of the composition (A) applied to the keratin fibers can range from 0.01 to 10. By bath ratio, we mean the ratio between the total weight of the composition (A) applied and the total weight of keratin fibers to be treated.

[0085] The process according to the invention may include at least one additional step a') of washing the keratin fibers prior to or simultaneous with step a), preferably prior to step a) and / or at least one additional step successive to step a) chosen from the following steps b) to d): b) a step of applying the composition (A) to the keratin fibers, preferably lasting at least 10 seconds, said application step possibly being carried out under a hermetic film such as a foil packet or plastic film; c) a rinsing and / or washing step of the keratin fibers; d) a step of drying the keratin fibers in ambient air or using a heating device.

[0086] Preferably, the process includes step a') as described above and additional steps b), c) and d) as described above and carried out in that order.

[0087] The composition application step (A) can last from 1 minute to 5 hours, preferably from 3 minutes to 1 hour, more preferably from 15 minutes to 40 minutes.

[0088] The washing step a') or c) can for example be carried out using a shampoo.

[0089] The temperature of the heating device can range from 45°C to 230°C, preferably from 45°C to 100°C, more preferably from 50°C to 80°C. A hair dryer, a heated helmet, a hair straightener or a heated brush can be used as a heating device.

[0090] Step d) of drying can also be a combination of air drying or drying with a heating device at a temperature ranging from 50°C to 80°C such as a hair dryer or a heated helmet, possibly followed by a step of passing through the iron, preferably a straightening iron.

[0091] Steps a') and a) to c) or steps a') and a) to d) may be repeated as many times as necessary, and each cycle of steps a) to c) or a) to d) may be separated from the next by a few minutes to a few days or weeks. Different hair treatments of the invention can be carried out between different application cycles, before or after.

[0092] In the case where the process does not include a step c) of rinsing and / or washing the keratin fibers, the composition may, for example, include a volatile mixture of solvents such as a water / ethanol mixture comprising at least 10% by weight, preferably at least 20% by weight, more preferably at least 30% by weight, and even more preferably at least 50% by weight of ethanol. The use of such a mixture makes it possible, in particular, to facilitate the evaporation of the vehicle of the composition. Composition (A)

[0093] According to a second aspect, the present invention relates to the composition (A) as defined above. Polyamine compounds

[0094] According to a third aspect, the present invention relates to a polyamine compound selected from compounds (1) and (2) as defined above, their optical isomers, their salts, their solvates such as hydrates, and their mixtures. Use

[0095] According to a fourth aspect, the present invention relates to the use of the polyamine compound(s) as defined above or of composition (A) as defined above, for the relaxation of curls and / or the smoothing of keratin fibers. Examples

[0096] The following examples serve to illustrate the invention without, however, being limiting in nature.

[0097] In the following examples, unless otherwise indicated, when compositions are implemented, the contents are indicated as a mass percentage in relation to the total weight of the composition considered. Synthesis of compound (1)

[0098] Compound (1) was synthesized according to the following scheme: oo . © © . z 5 s; js , xa H a ------------- H ■' HH 7 H A 8 comaasé {1 i

[0099] A solution of azelaic acid dichloride (11.9 mL, 59.2 mmol, 1 equiv.) in anhydrous CH2Cl2 (148 mL) is added dropwise to a solution of N-(tert-Butoxycarbonyl)-1,5-diaminopentane (Compound A) (24.7 g, 118 mmol, 2 equiv.) and N,N-Diisopropylethylamine (DIPEA) (21.9 mL, 124 mmol, 2.10 equiv.)

[0100]

[0101]

[0102]

[0103] in CH2Cl2 (148 mL) at 0°C. The ice bath is removed and the mixture is stirred at room temperature for 2 h. Water (200 mL) is added to the mixture and the volatiles are removed under reduced pressure. The resulting white solid is filtered and washed successively with water, a 10% aqueous solution of KHSO4, water, an aqueous solution of saturated NaHCO3, and finally water. The resulting white solid is dried in a desiccator under reduced pressure over P2O5 for approximately 24 h to yield the crude product as a white solid. The solid is triturated in diethyl ether, filtered, and washed twice with diethyl ether before being dried under reduced pressure to give compound B as a white solid (35.4 g). The solid proceeds to the next step without further purification. HCl (4N in 1,4-dioxane, 296 mL, 1.18 mol, 20 equiv.) is added dropwise to a suspension of compound B (35.4 g, 59.2 mmol, 1 equiv.) in dioxane (592 mL), and the mixture is stirred at room temperature for 22 h. The solid is filtered and washed with diethyl ether (2 x 70 mL). This solid is resuspended in water (200 mL), and Amberlite IR78 (OH form) resin is added until pH 10-11 is reached. The resin is removed by filtration, and the filtrate is concentrated under reduced pressure to give a white solid. The solid is resuspended in ethanol, and the suspension is stirred for 1 h at 50°C before being filtered. The filtrate is concentrated to give a white solid. The resulting white solid is dissolved in water (approx. 100 mL) and passed through an Amberlite IR78 (OH form) resin column. The product-containing fractions are collected and concentrated under reduced pressure, then co-evaporated twice with ethanol to give a white solid. Compound (1) is obtained in 90% yield in two steps. Synthesis of compound (2) Compound (2) was synthesized according to the following scheme: Bm U compound)

[0104] N,N-Düsopropylethylamine (DIPEA) (544 mL, 3.12 mol, 6.00 eq.) is added to a citric acid solution (100.00 g, 0.51 mol, 1.00 eq.) in tetrahydrofuran (1041 mL) in a 4 L double-jacketed glass reactor with mechanical stirring. Acetonitrile (1050 mL) is then added to the gelatinous mixture. To the resulting homogeneous solution, 1,(3-Dimethylaminopropyl)-3-Ethylcarbodiimide hydrochloride (EDCI) (399.1 g, 2.08 mol, 4.00 eq.) and then 2-Hydroxypyridine 1-oxide (HOPO) (231.3 g, 2.08 mol, 4.00 eq.) are added. The reaction mixture is stirred at room temperature for 10 minutes, then a solution of N-(tert-Butoxycarbonyl)-1,5-diaminopentane (368.5 g, 1.82 mol, 3.50 eq.) in acetonitrile (200 mL) is added. The reaction mixture is heated at 50°C for 3 h. The reaction mixture is concentrated under vacuum. The resulting oil is reconstituted in ethyl acetate (1400 mL) and water (800 mL).The phases are separated and the organic phase is washed with water (800 mL), HCl IN (2 x 800 mL), NaHCO3 sat (2 x 800 mL) and brine (1 x 1600 mL). The organic phase is then dried over Na2SO4, filtered and concentrated under vacuum to obtain compound C (390 g, 96%) as a brown oil.

[0105] Hydrogen chloride (4M in dioxane) (1.70 L, 6.96 mol, 14.0 eq.) is added to a solution in 1,4-dioxane (1.30 L, 0.36 M) of compound C (390.0 g, 0.497 mol, 1.00 eq.) previously obtained in a 4 L double-jacketed glass reactor with mechanical stirring. The reaction mixture is stirred at 25 °C overnight. The supernatant is then removed by aspiration, and the remaining solid is dissolved in a methanol / water mixture (1.40 L, 9:1). The solution is filtered through Amberlite IRN-78 (-2 kg), and the resin is washed before use with 2 L of 2M NaOH, 3 L of water, and 3 L of methanol. The resulting filtrate is concentrated under vacuum and then resuspended in water (1.0 L). The solution is treated with activated carbon (100 g, until no further discoloration is observed) and then filtered through Celite buffer. The resulting filtrate is concentrated under vacuum to reduce the volume to approximately µL, and the solution is lyophilized for 3 days.The gum obtained is then dried under high vacuum at 50°C for 2 days to obtain compound (2) with a yield of 86% in the form of a yellow gum.

[0106] The following compositions Al to A5 were prepared and then tested according to the procedure described below.

[0107] [Tables] Ingredients A1 (Invention) A2 (Comparative) A3 (Comparative) A4 (Comparative) A5 (Comparative) Compound (1) 10 10 - - - pH 1.0 buffer: 10% NH4OH / NH4Cl in Water / Ethanol (50 / 50) q.s. 100 q.s. 100 Water / Ethanol (50 / 50) solvent at pH 1.0 (pH adjusted by adding NH4OH) q.s. 100 Water / Ethanol (50 / 50) solvent at natural pH 7.5 q.s. 100 q.s. 100 Operating procedure

[0108] Strands of 2.7 g of natural hair, 27 cm in length and exhibiting a type IV curl pattern, were used. The strands were washed with two successive DOP shampoos (0.4 g / g of hair) before application of the compositions to be tested. 405 mg of each of the compositions A1 to A5 to be tested were then applied to separate damp strands of hair, previously towel-dried and blotted on absorbent paper. This application was carried out with the fingers while massaging the hair fiber. After a processing time of 30 minutes, the hair strands were combed and hung to dry at room temperature.

[0109] For each of the strands treated with compositions A1 to A5, measurements of the width at half-height and the length of the strand were taken after shampooing, drying at room temperature and combing and compared with the value obtained for a control hair strand that had only been washed with two successive DOP shampoos (0.4 g / g of hair). Results#:

[0110] [Tableaux2] Treatment type; Width at mid-height of 1 strand (cm); Strand length (cm) Control (Untreated hair) 10 23 Composition A1 (Invention) 8 26 Composition A2 (Comparative) 10 24.5 Composition A3 (Comparative) 9.5 24 Composition A4 (Comparative) 10.5 24 Composition A5 (Comparative) 10 24

[0111] The full width at half maximum (FWHM) of the strand treated with composition A1 according to the process of the invention is less than that measured on the strands treated with the comparative compositions A2 to A5 and on the control strand, and the length of the strand treated with composition A1 according to the process of the invention is greater than that measured on the strands treated with the comparative compositions A2 to A5 or on the control strand. The process according to the present invention therefore makes it possible to obtain good quality straightening, notably reducing the volume of the hair thus treated, without the use of a flat iron.

Claims

Demands

1. A process for treating keratin fibers comprising a) applying to the keratin fibers a composition (A) having a pH between 8 and 12.5 and comprising one or more polyamine compounds selected from the compounds of formula (I), their optical isomers, their geometric isomers, their salts, their solvates such as hydrates, and mixtures thereof: H2N—T—NH2 (I) Formula (I) in which T represents a divalent hydrocarbon group, linear or branched, saturated or unsaturated, preferably saturated, comprising from 4 to 22 carbon atoms, optionally substituted by an -NH2 group, the T group being substituted by one or more hydroxyl (-OH) groups and / or interrupted by one or more groups selected from -C(O)-, -NRa- or their combinations such as -NRa-C(O)- or -C(O)-NRa-, with Ra representing a hydrogen atom or a (Ci-C4)alkyl group.

2. A method according to the preceding claim, wherein T represents a divalent, linear or branched, saturated hydrocarbon group comprising from 4 to 22 carbon atoms, preferably from 10 to 22 carbon atoms, more preferably from 15 to 20 carbon atoms, optionally substituted by an -NH2 group, the group T being interrupted by one or more groups selected from -C(O)-, -NRa- or their combinations such as -NRa-C(O)- or -C(O)-NRa-, Ra being as defined in the preceding claim, preferably interrupted by one or more groups selected from -NRa-C(O)- or -C(O)-NRa-, Ra being as defined in the preceding claim and the group T being optionally substituted by one or more hydroxyl groups (-OH);preferably T represents a divalent, linear or branched, saturated hydrocarbon group comprising 10 to 22 carbon atoms, preferably 15 to 20 carbon atoms, optionally substituted by an -NH2 group, the T group being interrupted by 2 or 3 groups selected from -NH-(CO)- or -(CO)-NH- and the T group being optionally substituted by one or more hydroxyl groups (-OH), in particular a hydroxyl group (-OH).;

3.

4. A method according to claim 1, wherein T represents a divalent, linear or branched, saturated hydrocarbon group comprising from 4 to 22 carbon atoms, preferably from 4 to 15 carbon atoms, more preferably from 4 to 10 carbon atoms, substituted by one or more hydroxyl groups (-OH); preferably T represents a branched, saturated divalent hydrocarbon group comprising from 4 to 15 carbon atoms, preferably from 4 to 10 carbon atoms, substituted by one or more hydroxyl groups (-OH), preferably by a hydroxyl group (-OH). A process according to claim 1, wherein the polyamine compound(s) are selected from the following compounds (1), (2) and (3), their optical isomers, their salts, their solvates such as hydrates, and mixtures thereof:

5. compounds (1) and (2), their optical isomers, their salts, their solvates such as hydrates, and their mixtures. A process according to any one of the preceding claims, wherein the polyamine compound(s) are present in the composition (A) in a total content of at least 5% by weight, preferably from 5% to 50% by weight, more preferably from 5% to 30% by weight, relative to the total weight of the composition (A).

6. A method according to any one of the preceding claims, wherein the pH of the composition (A) is between 8.5 and 12.

5.

7. A method according to any one of the preceding claims, wherein the pH of the composition (A) is adjusted using an alkaline buffer system, preferably using an NH4OH / NH4Cl alkaline buffer system.

8. A process according to any one of the preceding claims, wherein the composition (A) comprises water and optionally one or more polar and / or protic solvents, preferably selected from monoalcohols having 2 to 6 carbon atoms, more preferably selected from ethanol, propanol, n-butanol, isopropanol, isobutanol, tert-butanol, pentanol, hexanol, and mixtures thereof, even more preferably selected from n-butanol, ethanol, and mixtures thereof, most preferably ethanol.

9. A method according to any one of the preceding claims, wherein the keratin fibers are curly, crimped, or frizzy keratin fibers.

10. A method according to any one of the preceding claims, wherein the method comprises at least one additional step a') of washing the keratin fibers prior to or simultaneous with step a), preferably prior to step a) and / or at least one additional step subsequent to step a) selected from the following steps b) to d): b) a step of applying the composition (A) to the keratin fibers, preferably of a duration of at least 10 seconds, said application step being optionally carried out under an airtight film such as foil or plastic film; c) a step of rinsing and / or washing the keratin fibers; d) a step of drying the keratin fibers in ambient air or with the aid of a heating device.

11. A method according to any one of the preceding claims, wherein the method is a method for relaxing loops and / or smoothing keratin fibers.

12. Composition (A) as defined in any one of claims 1 to 8.

13. A polyamine compound selected from the following compounds (1) and (2), their optical isomers, their salts, their solvates such as hydrates, and their mixtures:

14. Use of the polyamine compound(s) as defined in any one of claims 1 to 4 or of composition (A) as defined in any one of claims 1 to 8, for the relaxation of loops and / or the smoothing of keratin fibers.