A process for treating keratin fibers employing a composition comprising glycerol and at least one specific alkane-diol, the composition having a low water content

Abstract

The present invention relates to a process for treating keratin fibers using a composition comprising glycerol, at least one particular alkane-diol, the composition having a low water content.

Description

Title of the invention: A process for treating keratin fibers using a composition comprising glycerol and at least one specific alkane-diol, the composition having a low water content. Technical field of the invention

[0001] The present invention relates to a process for treating keratin fibers using a composition comprising glycerol, at least one particular alkane-diol, the composition having a low water content. 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] To remedy this problem, it is possible to permanently modify the shape of hair using a process comprising a reduction step employing one or more reducing agents chosen particularly from among sulfites, bisulfites, alkylphosphines, or preferably thiols, and a so-called fixing step employing one or more oxidizing agents, particularly hydrogen peroxide. However, this type of process can, 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 / or a degradation of its mechanical properties, particularly when the treated hair is already weakened, for example, colored or bleached hair. Furthermore, odor problems are very common with both the reducing compositions used, especially those containing thiols, and with the reduced hair.

[0004] It is also possible to permanently modify the shape of hair using a single-step process called lanthionization, which employs a composition comprising a base belonging to the hydroxide family. This type of process irreversibly replaces disulfide bonds (-CH2-SS-CH2-) with lanthionein bonds (-CH2-S-CH2-). This technique is primarily used for styling naturally curly hair. 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 affecting the condition of the hair, making it, on the one hand, rough to the touch and, on the other hand, much more fragile.

[0005] These classic techniques of permanent deformation of keratin fibers do not meet the needs of people wishing to temporarily change the shape of their hair, without risk of weakening it.

[0006] It is possible to temporarily deform hair by saturating it with water. However, the curl-relaxing or straightening effect observed is not lasting, and the curly hair treated in this way returns to its initial state. To improve the durability of the curl-relaxing or straightening effect, humectants such as glycerol can be used. However, the concentration of glycerol that can be used in hair formulations remains very limited due to the sticky effect it can produce. Indeed, the higher the glycerol concentration, the stickier, tackier, and / or more difficult the hair can be to style.

[0007] There is therefore a real need to develop a process for treating keratin fibers that leads to a temporary deformation of the keratin fibers, in order to smooth them and, when the hair is curly, to obtain better curl relaxation and / or better curl definition. The effect obtained must, in particular, be more durable and still observable for at least 6 hours, or even at least 24 or 48 hours after application of the process, without compromising the cosmetic properties, particularly regarding the stickiness of the compositions used in the process.

[0008] Such a process must also make it possible to preserve the quality and integrity of the treated fibers, making it possible to repeat the process, including on damaged and / or sensitized keratin fibers.

[0009] Furthermore, such a process must also employ 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 contribute to meeting global challenges. It is therefore essential to offer more sustainable cosmetic processing methods that address these environmental issues, notably by reducing the use of petrochemical-based compounds such as silicone raw materials.

[0010] 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

[0011] According to a first aspect, the present invention relates to a method for treating keratin fibers comprising a) applying to the keratin fibers a composition (C) comprising: (i) at least 5% by weight, relative to the total weight of composition (C), of glycerol; (ii) at least 5% by weight, relative to the total weight of composition (C), of one or more compounds A selected from the (C2-C6)alkane-diols; and iii) less than 5% by weight, relative to the total weight of the composition (C), of water.

[0012] According to a second aspect, the present invention relates to the composition (C) as defined above.

[0013] According to a third aspect, the present invention relates to the use of composition (C) as defined above, for the relaxation of curls and / or the smoothing of keratin fibers. Detailed description of the invention

[0014] For the purposes of the present invention, and unless otherwise indicated:

[0015] ■ By "keratin fibers" we mean fibers of human or animal origin such as hair, body hair, eyelashes, eyebrows, wool, angora, cashmere or fur.

[0016] According to the present invention, the keratin fibers are preferably human keratin fibers, more preferably hair.

[0017] ■ by "butylene glycol" means butane-1,3-diol.

[0018] The expressions "at least one" and "one or more" are synonymous and can be used interchangeably.

[0019] 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

[0020] According to a first aspect, the present invention relates to a process for treating keratin fibers as defined above.

[0021] The process according to the present invention is preferably a process for relaxing loops and / or smoothing keratin fibers.

[0022] The applicant has found, surprisingly, that the process according to the invention makes it possible to obtain a good quality smoothing of the keratin fibers and, when the hair is curly, better relaxation of the curls and / or better definition thereof, the effect observed being more lasting over time, in particular still observable for at least 6 hours, or even at least 24 or 48 hours after implementation of the process, without compromising with regard to the cosmetic quality of the composition used. work in the process according to the invention with in particular a slightly sticky and slightly tacky feel. Composition (C)

[0023] Composition (C) comprises: (i) at least 5% by weight, relative to the total weight of composition (C), of glycerol; (ii) at least 5% by weight, relative to the total weight of composition (C), of one or more compounds A selected from the (C2-C6)alkane-diols; and iii) less than 5% by weight, relative to the total weight of composition (C), of water. Glycerol content

[0024] Composition (C) comprises i) at least 5% by weight, relative to the total weight of composition (C), of glycerol.

[0025] Preferably, composition (C) comprises a total glycerol content of at least 8% by weight, preferably from 10% to 60% by weight, more preferably from 10% to 55% by weight, relative to the total weight of composition (C). Compounds A

[0026] Composition (C) further comprises ii) at least 5% by weight, relative to the total weight of composition (C), of one or more compounds A selected from the (C2-C6)alkane-diols.

[0027] Preferably, compound(s) A are chosen from the compounds of the following formula (I): HO-R-OH (I) Formula (I) in which R represents a divalent hydrocarbon radical, linear or branched, comprising from 2 to 6 carbon atoms.

[0028] According to a particular embodiment, the compound(s) A are selected from the compounds of formula (I) as defined above, in which R represents a linear divalent hydrocarbon radical comprising from 2 to 6 carbon atoms. According to this particular embodiment, the compound(s) A are preferably selected from propane-1,3-diol, butane-1,4-diol, pentane-1,5-diol, hexane-1,6-diol, ethylene glycol, their optical isomers, and mixtures thereof.

[0029] According to a particular embodiment, the compound(s) A are selected from compounds of formula (I) as defined above, in which R represents a divalent hydrocarbon radical, linear or branched, comprising from 3 to 5 carbon atoms. According to this particular embodiment, the compound(s) A are preferably selected from butylene glycol, propane-1,3-diol, butane-1,4-diol, 2-methyl-1,3-propanediol, pentane-1,5-diol, butane-1,2-diol, and their isomers. optical, and mixtures thereof, preferably from butylene glycol, propane-1,3-diol, their optical isomers, and mixtures thereof.

[0030] More preferably, the compound(s) A are selected from butylene glycol, propane-1,3-diol, butane-1,4-diol, 2-methyl-1,3-propanediol, pentane-1,5-diol, hexane-1,6-diol, butane-1,2-diol, ethylene glycol, their optical isomers, and mixtures thereof.

[0031] Even more preferably, the compound(s) A are chosen from butylene glycol, propane-1,3-diol, their optical isomers, and their mixtures.

[0032] Most preferably, the compound(s) A are chosen from mixtures of butylene glycol and propane-1,3-diol, the mass ratio of total quantity of butylene glycol / total quantity of propane-1,3-diol in composition (C) preferably ranging from 2 / 3 to 3 / 2.

[0033] Preferably, composition (C) comprises a total content of compounds A selected from (C2-C6)alkane-diols of at least 10% by weight, preferably from 10% to 95% by weight, more preferably from 40% to 90% by weight, relative to the total weight of composition (C).

[0034] More preferably, the composition (C) comprises a total content of compounds A selected from butylene glycol, propane-1,3-diol, butane-1,4-diol, 2-methyl-1,3-propanediol, pentane-1,5-diol, hexane-1,6-diol, butane-1,2-diol, ethylene glycol, their optical isomers, and mixtures thereof, of at least 5% by weight, preferably at least 10% by weight, more preferably from 10% to 95% by weight, even more preferably from 40% to 90% by weight, relative to the total weight of the composition (C).

[0035] Even more preferably, composition (C) comprises a total content of compounds A selected from butylene glycol, propane-1,3-diol, their optical isomers, and mixtures thereof, of at least 5% by weight, preferably of at least 10% by weight, more preferably from 10% to 95% by weight, even more preferably from 40% to 90% by weight, relative to the total weight of composition (C).

[0036] Most preferably, composition (C) comprises a total content of compounds A selected from mixtures of butylene glycol and propane-1,3-diol, of at least 5% by weight, preferably at least 10% by weight, more preferably from 10% to 95% by weight, even more preferably from 40% to 90% by weight, relative to the total weight of composition (C). Water

[0037] Composition (C) further comprises iii) less than 5% by weight, relative to the total weight of composition (C) of water.

[0038] Preferably, composition (C) comprises a total water content of less than 1% by weight, preferably less than 0.1% by weight, more preferably less than 0.01% by weight, relative to the total weight of composition (C), and even better composition (C) is anhydrous.

[0039] Where applicable, such small quantities of water may be introduced, in particular, by ingredients in the composition that may contain residual amounts. Other characteristics of the composition (C)

[0040] Composition (C) is preferably liquid, possibly thickened.

[0041] For the purposes of this invention, "liquid composition" refers, on a macroscopic scale, to a product that does not have a fixed shape and cannot be grasped, unlike a solid. It is a fluid that conforms to the shape of the container in which it is placed at room temperature (25°C). When transferred to another container, a liquid still retains its volume. A liquid therefore possesses a fixed volume. At rest, the free surface of a liquid is generally flat and horizontal.

[0042] By "thickened composition" in the context of the present invention is meant a liquid composition with a viscosity greater than 900 mPa.s at 25°C, or even a gel.

[0043] Preferably, composition (C) comprises a total ethanol content of less than 5% by weight, preferably less than 2% by weight, more preferably less than 1% by weight, even more preferably less than 0.1% by weight, most preferably less than 0.01% by weight, and better still less than 0.001% by weight, relative to the total weight of composition (C), and even better, composition (C) is free of ethanol.

[0044] Preferably, composition (C) comprises a total isopropanol content of less than 5% by weight, preferably less than 2% by weight, more preferably less than 1% by weight, even more preferably less than 0.1% by weight, most preferably less than 0.01% by weight, and better still less than 0.001% by weight, relative to the total weight of composition (C), and even better, composition (C) is free of isopropanol.

[0045] Preferably, composition (C) comprises a total Ci-C6 monoalcohol content of less than 5% by weight, preferably less than 2% by weight, more preferably less than 1% by weight, even more preferably less than 0.1% by weight, most preferably less than 0.01% by weight, and better still less than 0.001% by weight, relative to the total weight of composition (C), and even better, composition (C) is free of Ci-C6 monoalcohols. By "Ci-C6 monoalcohol" is meant a compound comprising only one hydroxyl group (-OH) of formula R-OH in which R represents a chain saturated hydrocarbon in Ci-C6, linear or branched, the hydroxyl group (-OH) can be carried by a primary, secondary or tertiary carbon atom.

[0046] Preferably, the composition (C) comprises a total silicone content of less than 5% by weight, preferably less than 2% by weight, more preferably less than 1% by weight, even more preferably less than 0.1% by weight, most preferably less than 0.01% by weight, and better less than 0.001% by weight relative to the total weight of the composition (C).

[0047] By "silicone" is meant all organosilicon polymers or oligomers with linear or cyclic, branched or cross-linked structure, of variable molecular weight, obtained by polymerization and / or polycondensation of suitably functionalized silanes, and consisting essentially of a repetition of principal motifs in which the silicon atoms are linked together by oxygen atoms (siloxane bond -Si-O-Si-), with hydrocarbon radicals possibly substituted, being directly linked via a carbon atom to said silicon atoms.

[0048] Preferably, composition (C) comprises a total cationic polymer content of less than 5% by weight, preferably less than 2% by weight, more preferably less than 1% by weight, even more preferably less than 0.1% by weight, most preferably less than 0.01% by weight, and better less than 0.001% by weight, relative to the total weight of composition (C), and even better composition (C) is free of cationic polymers.

[0049] By "cationic polymer" is meant any non-siliconized polymer (not comprising silicon atoms) containing cationic groups and / or groups ionizable into cationic groups, and not containing anionic groups and / or groups ionizable into anionic groups.

[0050] Preferably, composition (C) comprises a total cationic surfactant content of less than 5% by weight, preferably less than 2% by weight, more preferably less than 1% by weight, even more preferably less than 0.1% by weight, most preferably less than 0.01% by weight, and better still less than 0.001% by weight relative to the total weight of composition (C), and even better composition (C) is free of cationic surfactants.

[0051] Preferably, composition (C) comprises a total content of poly(oxyethylenated) compounds of less than 5% by weight, preferably less than 2% by weight, more preferably less than 1% by weight, even more preferably less than 0.1% by weight, most preferably less than 0.01% by weight, and better still less than 0.001% by weight relative to the total weight of composition (C), and even better composition (C) is free of poly(oxyethylenated) compounds.

[0052] The composition (C) may further comprise at least one cosmetic ingredient selected from non-ionic, anionic, amphoteric surfactants, vitamins and pro-vitamins other than vitamin B1 including panthenol, fillers, coloring materials, pearlescent agents, opacifying agents, sequestering agents, film-forming polymers, anionic or neutral, associative polymers, plasticizing agents, oils, antifoaming agents, moisturizing agents, emollients, penetration agents, perfumes, preservatives, and mixtures thereof.

[0053] The composition (C) may further include at least one cosmetic ingredient selected from sequestering agents, oils, moisturizing agents, emollients, penetration agents, perfumes, preservatives, and mixtures thereof.

[0054] These common cosmetic ingredients may be present in the composition in typical quantities, easily determinable by those skilled in the art, and which may range, for each ingredient, from 0.01% to 20% by weight relative to the total weight of the composition. Those skilled in the art shall ensure that the ingredients included in the composition, as well as their quantities, are chosen in such a way that they do not impair the properties of the composition.

[0055] Composition (C) is a cosmetic composition, i.e. which includes a cosmetically acceptable medium, i.e. a medium compatible with human keratin fibers.

[0056] Preferably, composition (C) comprises a total content of colouring agents of less than 0.1% by weight, preferably less than 0.01% by weight, more preferably less than 0.001% by weight, relative to the total weight of composition (C).

[0057] Even more preferably, composition (C) is free of coloring agents.

[0058] By "coloring agent" is meant an oxidation dye, a direct dye or a pigment.

[0059] The term "oxidation dye" refers to an oxidation dye precursor selected from oxidation bases and couplers. Oxidation bases and couplers are compounds that are slightly colored or colorless and which, through a condensation reaction in the presence of an oxidizing agent, give a colored species.

[0060] By "direct dye" is meant a natural and / or synthetic dye, including in the form of extract(s), other than 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.

[0061] The composition (C) 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.

[0062] Additional features concerning the process

[0063] Composition (C) can be applied to dry or moist keratin fibers.

[0064] The process according to the invention can be implemented on natural keratin fibers, in particular natural hair.

[0065] The process according to the invention can also be implemented on damaged and / or sensitized keratin fibers, in particular damaged and / or sensitized hair.

[0066] By "damaged keratin fibers" we mean dry, rough, brittle, split and / or soft keratin fibers.

[0067] By "sensitized keratin fibers" is meant bleached, artificially colored, straightened and / or permed keratin fibers.

[0068] The process according to the invention can advantageously be implemented on curly, frizzy or kinky keratin fibers, in particular curly, frizzy or kinky hair.

[0069] The bath ratio of the composition (C) 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 (C) applied and the total weight of keratin fibers to be treated.

[0070] The process according to the invention may include at least one additional step a') of washing the keratin fibers, preferably prior to step a) and / or at least one additional step following step a) chosen from the following steps b) and / or c): b) a step of applying the composition (C) to the keratin fibers, preferably lasting at least 10 seconds, said application step possibly being carried out under an airtight film such as a papillote or plastic film; c) a drying step of the keratin fibers in ambient air or with the aid of a heating device, preferably in ambient air.

[0071] Preferably, the process includes step a') as described above and additional steps b) and c) as described above and carried out in that order.

[0072] The washing step a') can for example be carried out using shampoo.

[0073] 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, an iron, or a heated brush can be used as a heating device, for example. Composition (C)

[0074] According to a second aspect, the present invention relates to the composition (C) as defined above.

[0075]

[0076]

[0077] Use According to a third aspect, the present invention relates to the use of composition (C) as defined above, for the relaxation of curls and / or the smoothing of keratin fibers. Examples The following examples serve to illustrate the invention without being limiting. In the examples that follow, unless otherwise indicated, where compositions are used, the contents are given as mass percentages relative to the total weight of the composition in question. The following Cl to C3 and DI to D4 compositions were prepared and tested according to protocol 1 or 2 described below. Compositions Cl to C3

[0078] [Table 1] Ingredients Cl (Comparative) C2 (Comparative) C3 (Comparative) Butylene glycol 100 - - Propane-1,3-diol - 100 - Glycerol - - 100 Compositions DI to D4

[0079] [Tables 2] Ingredients DI (Invention) D2 (Invention) D3 (Invention) D4 (Invention) Butylene glycol 50 - 42 34 Propane-1,3-diol - 50 43 33 Glycerol 50 50 15 33

[0080] Protocol 1 (application on dry hair) Strands of 2.7 g of natural hair, type 2C according to the André Walker classification, are used. The strands are washed with two successive DOP shampoos (0.4 g / g of hair), then towel-dried and finally left to air dry before application of the compositions to be tested. 0.15g of each of the compositions to be tested are then applied to dry strands. This application is done with the fingers while massaging the hair fiber. The hair strands are then suspended at ambient temperature and humidity set at 22°C and 45% relative humidity. Protocol 2 (application on damp hair)

[0081] Strands of 2.7 g of natural hair, type 2C according to the André Walker classification, are used. The strands are washed with two successive DOP shampoos (0.4 g / g of hair) and then towel-dried before application of the compositions to be tested. 0.15 g of each of the compositions to be tested are then applied to the damp strands. This application is done with the fingers while massaging the hair fiber. The hair strands are then suspended at ambient temperature and humidity set at 22°C and 45% relative humidity.

[0082] For each of the treated strands, the calculation of the percentage of strand elongation was carried out 6h or 48h after application, in order to evaluate the effectiveness of the treatment.

[0083] The percentage of elongation of the wick 6h or 48h after application is calculated according to the following formula: (L - Lj •- x 100 in which L represents the length of the strand 6h or 48h after application and Lo represents the length of the initial strand before application of the composition to be tested. Results:

[0084] Percentage of strand elongation 6 hours after application

[0085] [Tables3] Treatment Type Protocol Percentage of Elongation 6h Post Application Cl (Comparative) 1 4.69 C2 (Comparative) 1 1.96 C3 (Comparative) 1 0.51 D3 (Invention) 1 6.24 D3 (Invention) 2 14.57

[0086] Strands treated with composition D3 according to the invention exhibit a higher percentage of elongation 6 hours after application than strands treated with comparative compositions C1 to C3. The process according to the present invention therefore makes it possible to obtain good quality straightening with better curl relaxation 6 hours after application of composition D3. Furthermore, the sticky appearance The stickiness of hair strands treated with composition D3 according to the invention is not prohibitive, unlike the stickiness of hair strands treated with the comparative composition C3.

[0087] Percentage of strand elongation 48 h after application

[0088] [Tables4] Treatment Type Protocol Percentage of Elongation 48 h after application Cl (Comparative) 1 0.82 C2 (Comparative) 1 -2.53 C3 (Comparative) 1 -1.44 DI (Invention) 1 2.67 D2 (Invention) 1 2.05 D3 (Invention) 1 5.13 D4 (Invention) 1 3.84

[0089] Strands treated with compositions DI to D4 according to the invention exhibit a higher percentage of elongation 48 hours after application than strands treated with comparative compositions C1 to C3. The process according to the present invention therefore makes it possible to obtain good quality straightening with better curl relaxation 48 hours after application of compositions DI to D4. Furthermore, the sticky appearance of the hair strand treated with compositions DI to D4 according to the invention is not a drawback, unlike the sticky appearance of the hair strand treated with comparative composition C3.

Claims

Demands

1. A process for treating keratin fibers comprising a) applying to the keratin fibers a composition (C) comprising: i) at least 5% by weight, relative to the total weight of the composition (C), of glycerol; ii) at least 5% by weight, relative to the total weight of the composition (C), of one or more compounds A selected from the (C2-C6)alkane-diols; and iii) less than 5% by weight, relative to the total weight of the composition (C), of water.

2. A method according to any one of the preceding claims, wherein the composition (C) comprises a total glycerol content of at least 8% by weight, preferably from 10% to 60% by weight, more preferably from 10% to 55% by weight, relative to the total weight of the composition (C).

3. A method according to any one of the preceding claims, wherein the composition (C) comprises a total content of compounds A of at least 10% by weight, preferably from 10% to 95% by weight, more preferably from 40% to 90% by weight, relative to the total weight of the composition (C).

4. A method according to the preceding claim, wherein the compound(s) A are selected from the compounds of the following formula (I): HO-R-OH (I) Formula (I) in which R represents a divalent hydrocarbon radical, linear or branched, comprising from 2 to 6 carbon atoms; preferably from butylene glycol, propane-1,3-diol, butane-1,4-diol, 2-methyl-1,3-propanediol, pentane-1,5-diol, hexane-1,6-diol, butane-1,2-diol, ethylene glycol, their optical isomers, and mixtures thereof; more preferably from butylene glycol, propane-1,3-diol, their optical isomers, and mixtures thereof; even more preferentially among the mixtures of butylene glycol and propane-1,3-diol, the mass ratio of total quantity of butylene glycol / total quantity of propane-1,3-diol in the composition (C) preferably ranging from 2 / 3 to 3 / 2.

5. A method according to any one of the preceding claims, wherein the composition (C) comprises a total water content of less than 1% by weight, preferably less than 0.1% by weight, more preferably less than 0.01% by weight, relative to the total weight of the composition (C), and even better the composition (C) is anhydrous.

6. A method according to any one of the preceding claims, wherein the composition (C) is liquid, optionally thickened.

7. A method according to any one of the preceding claims, wherein the composition (C) comprises a total ethanol content of less than 5% by weight, preferably less than 2% by weight, more preferably less than 1% by weight, even more preferably less than 0.1% by weight, most preferably less than 0.01% by weight, and better still less than 0.001% by weight, relative to the total weight of the composition (C), and even better, the composition (C) is free of ethanol.

8. A method according to any one of the preceding claims, wherein the composition (C) comprises a total isopropanol content of less than 5% by weight, preferably less than 2% by weight, more preferably less than 1% by weight, even more preferably less than 0.1% by weight, most preferably less than 0.01% by weight, and better still less than 0.001% by weight, relative to the total weight of the composition (C), and even better, the composition (C) is isopropanol-free.

9. A method according to any one of the preceding claims, wherein the composition (C) comprises a total silicone content of less than 5% by weight, preferably less than 2% by weight, more preferably less than 1% by weight, even more preferably less than 0.1% by weight, most preferably less than 0.01% by weight, and better yet less than 0.001% by weight, relative to the total weight of the composition (C).

10. A method according to any one of the preceding claims, wherein the composition (C) comprises a total cationic polymer content of less than 5% by weight, preferably less than 2% by weight, more preferably less than 1% by weight, even more preferably less than 0.1% by weight, most preferably less than 0.01% by weight, and better still less than 0.001% by weight, relative to the total weight of the composition (C), and even better, composition (C) is free of cationic polymers.

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

12. 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, preferably prior to step a) and / or at least one additional step subsequent to step a) selected from the following steps b) and / or c): b) a step of applying the composition (C) 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 drying the keratin fibers in ambient air or with the aid of a heating device, preferably in ambient air.

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

14. Composition (C) as defined in any one of claims 1 to 10.

15. Use of composition (C) as defined in any one of claims 1 to 10, for the relaxation of curls and / or the smoothing of keratin fibers.