A cosmetic process for strengthening straightened hair with a composition including cysteine ​​and a specific fatty acid triglyceride.

Abstract

Cosmetic process for strengthening straightened hair with a composition comprising cysteine ​​and a particular fatty acid triglyceride. The application relates to a cosmetic process for treating straightened keratin fibers, comprising the application to said keratin fibers of a cosmetic composition comprising: (i) cysteine ​​and / or one of its derivatives and salts, (ii) one or more fatty acid triglycerides containing 6 to 16 carbon atoms in a total amount greater than or equal to 1% by weight, relative to the total weight of the composition, and (iii) optionally one or more additional reducing agents other than cysteine ​​and / or one of its derivatives (i) in a total amount less than or equal to 1% by weight, relative to the total weight of the composition; the pH of said composition ranging from 7.5 to 10. Figure for abstract: none

Description

Title of the invention: Cosmetic process for strengthening straightened hair with a composition comprising cysteine ​​and a particular fatty acid triglyceride

[0001] The invention relates to a cosmetic process for treating smoothed keratin fibers, in particular human keratin fibers such as hair, comprising the application of a cosmetic composition comprising cysteine ​​and a particular fatty acid triglyceride.

[0002] Many people are dissatisfied with the appearance of their hair and find it difficult to style. Curly hair is particularly difficult to comb and detangle, requiring considerable time and effort to achieve a result that is often disappointing. Aligning the hair fibers is challenging, the result contradicts the hair's natural inclination, and the hair becomes tangled as it reorganizes itself in its lowest energy state. Others wish to transition more easily from one hairstyle to another and achieve these hairstyles effortlessly.

[0003] People with curly or frizzy hair often use relaxers (or straighteners) to help them overcome these manageability challenges.

[0004] Relaxing (or smoothing) treatments require the use of alkaline products. These products can be aggressive, especially when used repeatedly, and damage the hair, thus compromising its integrity.

[0005] Furthermore, this already sensitized hair is also damaged and weakened by the action of external atmospheric agents such as light and inclement weather, as well as by mechanical or chemical treatments, such as brushing, combing, dyeing, bleaching, and perming. The hair is therefore damaged by these various factors and can, over time, become dry, rough, or dull, particularly in fragile areas.

[0006] Consequently, curly hair is subject to much damage, especially when straightened, and requires special treatment to restore its integrity.

[0007] Currently available treatments generally aim to improve the conditioning properties of hair, namely softness, shine, smoothness, suppleness, lightness, natural feel and good detangling properties.

[0008] However, these improvements are cosmetic and these treatments do not address the integrity of the hair, i.e. the mechanical properties of the hair.

[0009] It is therefore truly necessary to develop a process for restoring the integrity of hair, in particular straightened hair, such as curly or frizzy hair. This process must strengthen previously straightened hair, especially in terms of its mechanical properties, such as resistance to breakage and elasticity.

[0010] The process must also improve the combing, styling and detangling properties of hair, in particular, curly hair to frizzy hair that has been previously straightened.

[0011] It has now been discovered that a cosmetic process for treating smoothed keratin fibers, in particular human keratin fibers such as hair, comprising the application of a composition comprising the combination of cysteine, and / or one of its derivatives, and a particular fatty acid triglyceride makes it possible to achieve at least one of the above objectives, in particular in terms of restoring hair and improving the mechanical properties of hair.

[0012] Thus, the object of the invention is a cosmetic process for treating smoothed keratin fibers, in particular, human keratin fibers such as hair, preferably straightened curly or frizzy hair, comprising the application to said keratin fibers of a cosmetic composition comprising:

[0013] (i) of cysteine ​​and / or one of its derivatives such as N-acetylcysteine, N- alcanoylcysteine ​​and alkyl esters of cysteine ​​and their salts,

[0014] (ii) one or more fatty acid triglycerides containing 6 to 16 carbon atoms in a total amount greater than or equal to 1% by weight, relative to the total weight of the composition and

[0015] (lii) optionally one or more additional reducing agents other than cysteine ​​and / or one of its derivatives (i) in a total quantity less than or equal to 1% by weight, relative to the total weight of the composition;

[0016] the pH of said composition ranging from 7.5 to 10.

[0017] The process of the present invention is capable of improving the integrity and mechanical properties of hair that has already undergone a straightening treatment, in particular, curly or frizzy hair.

[0018] Furthermore, the process of the invention is also capable of improving the conditioning properties of smoothed keratin fibers, in particular human keratin fibers such as hair, in particular, in terms of shine, softness, smoothness and suppleness, while giving the hair a good wet and dry combing and hydration effect.

[0019] People with curly or frizzy hair who experience styling difficulties and wish to use a smoothing treatment now have access to a a process that restores the integrity and improves the mechanical properties of the hair fiber.

[0020] Hair, especially curly hair, treated with the process of the present invention is strengthened, healthier, easier to style and allows the consumer to obtain the desired hairstyle.

[0021] Other subjects, features, aspects and advantages of the invention will become even clearer upon reading the description and example that follows.

[0022] The term “smoothed keratin fibers” refers to keratin fibers that have undergone a straightening, relaxing, or smoothing treatment using a reducing agent or a hydroxide. When the smoothing treatment uses a reducing agent, the term “smoothed keratin fibers” is intended to refer to keratin fibers that have undergone the entire smoothing treatment, namely the reduction step and the oxidation step using an oxidizing composition (fixative). Preferably, the smoothed keratin fibers of the invention are fibers that have undergone a smoothing treatment with a hydroxide such as an alkali or alkaline earth hydroxide, in particular, sodium hydroxide, lithium hydroxide, potassium hydroxide, calcium hydroxide, and / or guanidine hydroxide.

[0023] In what follows and unless otherwise indicated, the limits of a range of values ​​are included in that range, in particular, in the expressions "between" and "from... to...".

[0024] Furthermore, the expression "at least one" used in this description is equivalent to the expression "one or more". (i) Cysteine

[0025] The process according to the present invention comprises the application to smoothed keratin fibers, in particular to human keratin fibers such as hair, of a composition comprising cysteine ​​and / or one of its derivatives such as N-acetylcysteine, N-alcanoylcysteine ​​and alkyl esters of cysteine ​​and their salts.

[0026] The total amount of cysteine ​​and / or one of its derivatives such as N-acetylcysteine, N-alcanoylcysteine ​​and alkyl esters of cysteine, present in the composition according to the present invention, is preferably less than or equal to 1% by weight, better still this total amount is from 0.05 to 1% by weight, better still from 0.1 to 1% by weight, and better still from 0.5 to 0.8% by weight, relative to the total weight of the composition. (ii) Fatty acid triglyceride

[0027] The composition applied in the process according to the present invention further comprises one or more fatty acid triglycerides (ii) containing 6 to 16 carbon atoms.

[0028] In particular, the fatty acid triglycerides (ii) of the invention have the following general formula: 1X1 ___q__$2 --O—R3

[0029] In which RI, R2 and R3, which may be identical or different, denote linear or branched, saturated or unsaturated C6-Ci6 alkyl groups, preferably C6-CM alkyl groups and, even better, C6-Ci2 alkyl groups.

[0030] The useful fatty acid triglyceride(s) according to the present invention can (may) be derived from triglycerides of vegetable origin, such as vegetable oils, or from triglycerides of synthetic origin.

[0031] Preferably, the fatty acid triglyceride(s) contain 6 to 14 carbon atoms and, even better, 6 to 12 carbon atoms.

[0032] Preferably, the vegetable oils that can be used according to the invention comprise more than 50% by weight of fatty acid triglycerides containing 6 to 16 carbon atoms, preferably 6 to 14, better still 6 to 12 carbon atoms.

[0033] Advantageously, the fatty acid triglyceride(s) are selected from coconut oil, caprylic / capric acid triglycerides, palm kernel oil, babassu oil, cuphea oil and mixtures thereof, in particular coconut oil.

[0034] The total amount of fatty acid triglycerides (ii) containing 6 to 16 carbon atoms, which are present in the composition according to the present invention, is greater than or equal to 1% by weight, relative to the total weight of the composition. Preferably, the total amount of fatty acid triglycerides (ii) containing 6 to 16 carbon atoms ranges from 1 to 15% by weight and, even better, from 2 to 10% by weight, relative to the total weight of the composition.

[0035] The weight ratio (R) between the total quantity of fatty acid triglycerides (ii) containing 6 to 16 and the total quantity of cysteine ​​and / or one of its derivatives (i), present in the composition according to the present invention, is preferably greater than or equal to 1. Better still, this weight ratio (R) is from 1 to 20, and even better still from 2 to 15. (iii) Additional reducing agents

[0036] The composition applied in the process according to the present invention further optionally comprises one or more additional reducing agents other than cysteine ​​and / or one of its derivatives (i) in a total quantity less than or equal to 1% by weight, relative to the total weight of the composition. In other words, the total quantity of additional reducing agents (iii) other than cysteine ​​and / or one of its derivatives (i), when present in the composition of the invention, is less than or equal to 1% by weight, relative to the total weight of the composition.

[0037] In a particularly preferred manner, the composition applied in the process according to the present invention further comprises one or more additional reducing agents other than cysteine ​​and / or one of its derivatives (i).

[0038] Additional reducing agents (iii) other than cysteine ​​and / or one of its derivatives (i) are chosen, preferably, from thiol-based reducing agents, other than cysteine ​​or its derivatives (i), non-thiol-based reducing agents and mixtures thereof.

[0039] A "thiol-based reducing agent" is understood to mean a reducing agent containing at least one thiol group. Examples of thiol-based reducing agent(s) other than cysteine ​​or its derivatives (i) include thioglycolic acid and its derivatives, in particular its esters such as glycerol or glycol monothioglycolate; thiolactic acid and its derivatives, in particular its esters such as glycerol monothiolactate; 3-mercaptopropionic acid and its derivatives, in particular its esters such as glycerol 3-mercaptopropionate and ethylene glycol 3-mercaptopropionate; cysteamine and its derivatives, in particular its CrC4 acylated derivatives such as N-acetylcysteamine and N-propionylcysteamine; mono-thioglycerol and its derivatives, in particular its esters; and their salts.

[0040] A "non-thiol-based reducing agent" means a reducing agent not containing a thiol group. Examples of non-thiol-based reducing agent(s) include sulfites, sulfite derivatives, sulfinates, phosphines, sugars, dihydroxybenzene derivatives, reductones, hydrides, ascorbic acid, ascorbic acid derivatives, tocopherols, tocopherol derivatives, EDTA, panthenol, selenium sulfide, zinc formosulfoxylate and mixtures thereof.

[0041] Additional reducing agents (iii) other than cysteine ​​and / or one of its derivatives (i) are preferably chosen from non-thiol-based reducing agents and mixtures thereof, better still, from sulfites, sulfite derivatives, ascorbic acid, ascorbic acid derivatives, tocopherols, tocopherol derivatives and mixtures thereof.

[0042] The term "sulfite derivatives" essentially refers to bisulfites and sulfite diesters of formula RO-SO2-R', R and R' designating the alkyl groups Ci-Cio.

[0043] The term "ascorbic acid derivatives" essentially refers to erythorbic acid, isoascorbic acid, magnesium ascorbyl phosphate and ascorbyl glucoside.

[0044] The tocopherols that can be used in the present invention include, for example, alpha-tocopherol, beta-tocopherol, gamma-tocopherol and delta-tocopherol, while the term "tocopherol derivatives" essentially refers to tocopherol esters, such as tocopheryl acetate.

[0045] Additional reducing agents (iii) may be used, in particular in the form of salts, especially alkali metal salts such as sodium and potassium salts, alkaline earth metal salts, for example magnesium and calcium salts, ammonium salts, amine salts and amino alcohol salts.

[0046] Particularly preferred, the additional reducing agents (iii), other than cysteine ​​and / or one of its derivatives (i), are selected from alkali metal sulfites, alkali metal bisulfites, precursors of these sulfites or bisulfites, and mixtures thereof. More preferably, the additional reducing agents (iii) are selected from sodium sulfite, sodium bisulfite, sodium metabisulfite, and mixtures thereof.

[0047] According to another particularly preferred embodiment, the additional reducing agents (iii) other than cysteine ​​and / or one of its derivatives (i) are selected from sulfites, sulfite derivatives, ascorbic acid, ascorbic acid derivatives, tocopherols, tocopherol derivatives, and mixtures thereof. Preferably, the additional reducing agents (iii) according to this embodiment correspond to a mixture of at least two distinct non-thiol-based reducing agents, in which preferably: - at least one is chosen from among sulfites, sulfite derivatives and mixtures thereof, or better still, from among alkali metal sulfites, alkali metal bisulfites, precursors of these sulfites or bisulfites, and mixtures thereof, or better still, from sodium sulfite, sodium bisulfite, sodium metabisulfite and mixtures thereof and - the other is chosen from ascorbic acid, ascorbic acid derivatives and mixtures thereof, and better still, from ascorbic acid, alpha-tocopherol, tocopheryl acetate, erythorbic acid, isoascorbic acid, magnesium ascorbyl phosphate, ascorbyl glucoside and mixtures thereof.

[0048] The total quantity of additional reducing agents (iii) other than cysteine ​​and / or one of its derivatives (i), when present in the composition according to the invention, is less than or equal to 1% by weight, preferably from 0.05 to 1% by weight, better still from 0.1 to 0.8% by weight, even better still from 0.1 to 0.5% by weight, and even better still from 0.15 to 0.3% by weight, relative to the total weight of the composition.

[0049] In a preferred embodiment, the additional reducing agents (iii) other than cysteine ​​and / or one of its derivatives (i) are selected from sulfites, sulfite derivatives, ascorbic acid, ascorbic acid derivatives and mixtures thereof, and the total amount of sulfites, sulfite derivatives, ascorbic acid and ascorbic acid derivatives present in the composition according to the invention is less than or equal to 1% by weight, and preferably ranges from 0.05 to 1% by weight, better still from 0.1 to 0.8% by weight, better still from 0.1 to 0.5% by weight, and better still from 0.15 to 0.3% by weight, relative to the total weight of the composition.

[0050] The weight ratio (Ra) between the total quantity of cysteine ​​and / or one of its derivatives (i) and the total quantity of additional reducing agents (iii) other than cysteine ​​and / or one of its derivatives (i), when present in the composition according to the present invention, is preferably greater than or equal to 1. Better still, this weight ratio (R) goes from 1 to 15, and even better still from 2 to 10. Additional fatty substances

[0051] The composition applied in the process according to the present invention may, in addition, comprise one or more additional fatty substances, different from the fatty acid triglycerides (ii) described above.

[0052] The term "fatty substance" means an organic compound that is insoluble in water at room temperature (25°C) and atmospheric pressure (760 mmHg) (solubility less than 5%, preferably 1%, and even better 0.1%). Fatty substances have in their structure at least one hydrocarbon chain comprising at least 6 carbon atoms or a sequence of at least two siloxane groups. In addition, fatty substances are generally soluble in organic solvents under the same conditions of temperature and pressure, for example, chloroform, dichloromethane, carbon tetrachloride, ethanol, benzene, toluene, tetrahydrofuran (THF), petrolatum, or decamethylcyclopentasiloxane.

[0053] Preferably, the fatty substances of the invention do not contain any salified or unsalified carboxylic acid group (-C(O)OH or -C(O)O). In particular, the fatty substances of the invention are neither polyoxyalkylated nor polyglycerolated.

[0054] The expression "non-siliconized fatty substance" refers to a fatty substance not containing silicon (Si) atoms and the expression "siliconized fatty substance" refers to a fatty substance containing at least one silicon atom.

[0055] More particularly, the additional fatty substance(s), other than the fatty acid triglyceride(s) containing 6 to 16 carbon atoms, are chosen from among C6 to C11 hydrocarbons, hydrocarbons containing more than 16 carbon atoms, non-siliconized oils of animal origin, triglycerides other than the fatty acid triglycerides (ii) described above, fluorinated oils, alcohols non-polyoxyalkylated fats, esters of fatty acids and / or fatty alcohols other than triglycerides, vegetable waxes, non-siliconized waxes, silicones and their mixtures.

[0056] It is recalled that, for the purposes of the invention, fatty alcohols, fatty esters and fatty acids more particularly contain one or more linear or branched, saturated or unsaturated hydrocarbon groups comprising 6 to 30 carbon atoms, which are optionally substituted, in particular by one or more hydroxyl groups (in particular 1 to 4). If they are unsaturated, these compounds may comprise one to three conjugated or non-conjugated carbon-carbon double bonds.

[0057] As regards hydrocarbons in the C6 to C16 range, they are linear, branched, or possibly cyclic, and are preferably alkanes. Examples that can be mentioned include hexane, dodecane, and isoparaffins such as isohexadecane and isodecane.

[0058] One hydrocarbon oil of animal origin that can be mentioned is perhydrosqualene.

[0059] The triglyceride other than the fatty acid triglyceride (ii) containing 6 to 16 carbon atoms is preferably selected from the liquid fatty acid triglycerides containing 18 to 30 carbon atoms, for example sunflower oil, corn oil, soybean oil, pumpkin oil, rapeseed oil, grapeseed oil, sesame oil, hazelnut oil, apricot oil, macadamia oil, ara oil, castor oil, avocado oil, jojoba oil and mixtures thereof.

[0060] Linear or branched hydrocarbons of mineral or synthetic origin, containing more than 16 carbon atoms, are preferably selected from liquid paraffins, petrolatum, petrolatum oil, polydecenes and hydrogenated polyisobutene such as Parleam®;

[0061] Fluorinated oils can be selected from perfluoromethylcyclopentane and perfluoro-1,3-dimethylcyclohexane, marketed under the names Flutec® PCI and Flutec® PC3 by BNFL Fluorochemicals; perfluoro-1,2-dimethylcyclobutane; perfluoroalkanes such as dodecafluoropentane and tetrafluorohexane, marketed under the names PF 5050® and PF 5060® by 3M, or bromoperfluorooctyl marketed under the name Foralkyl® by Atochem; nonafluoromethoxybutane and nonafluoroethoxyisobutane; perfluoromorpholine derivatives such as 4-trifluoromethyl perfluoromorpholine marketed under the name PF 5052® by 3M.

[0062] The non-polyoxyalkylated fatty alcohols that can be used in the composition according to the invention are saturated or unsaturated, and linear or branched, and comprise from 8 to 30 carbon atoms and, more particularly, from 10 to 24 carbon atoms. Examples include cetyl alcohol, stearyl alcohol, and mixtures thereof. (cetylstearyl alcohol), octyldodecanol, 2-butyloctanol, 2-hexyldecanol, 2-undecylpentadecanol, oleyl alcohol or linoleyl alcohol.

[0063] The wax or waxes that can be used in the composition according to the invention are chosen, in particular, from carnauba wax, candelilla wax, esparto grass wax, paraffin wax, ozokerite, vegetable waxes, for example olive wax, rice wax, hydrogenated jojoba wax or absolute flower waxes such as blackcurrant flower essential wax marketed by the Bertin company (France), animal waxes, for example beeswax, or modified beeswax (cerabelline); other waxes or waxy starting materials that can be used according to the invention are, in particular, marine waxes such as the product marketed by the Sophim company under reference M82, and polyethylene or polyolefin waxes in general.

[0064] With regard to fatty acid and / or fatty alcohol esters, which are advantageously different from the triglycerides mentioned above, one may cite, in particular, the esters of saturated or unsaturated, linear or branched aliphatic mono- or polyacids from C1 to C2 and of saturated or unsaturated, linear or branched aliphatic mono- or polyalcohols from C1 to C2, the total number of carbons of the esters being more particularly greater than or equal to 10.

[0065] Among the monoesters, the following may be mentioned, without limitation: dihydroabietyl behenate, octyldodecyl behenate, isocetyl behenate, cetyl lactate, C12-C15 alkyl lactate, isostearyl lactate, lauryl lactate, linoleyl lactate, oleyl lactate; (iso)stearyl octanoate; isocetyl octanoate; octyl octanoate; cetyl octanoate; decyl oleate; isocetyl isostearate; isocetyl laurate; isocetyl stearate; isodecyl octanoate; isodecyl oleate; isononyl isononanoate; isostearyl palmitate; acetyl methyl ricinoleate; myristyle stearate; octyl isononanoate; 2-ethylhexyl isononate; octyl palmitate; octyl pelargonate; octyl stearate; octyldodecyl erucate; oleyl erucate;ethyl and isopropyl palmitates, 2-ethylhexyl palmitate, 2-octyldecyl palmitate, alkyl myristates such as isopropyl, butyl, cetyl, 2-octyldodecyl, myristyle, stearyl myristate, hexyl stearate, butyl stearate, isobutyl stearate; dioctyl malate, hexyl laurate, 2-hexyldecyl laurate.

[0066] Still within the context of this variant, esters of dicarboxylic or tricarboxylic acids in C4 to C22 and of alcohols in C1 to C22 and esters of mono-, di- or tricarboxylic acids and di-, tri-, tetra- or hydroxy alcohols in C2 to C26 can also be used.

[0067] In particular, mention may also be made of: diethyl sebacate; diisopropyl sebacate; diisopropyl adipate; di(n-propyl) adipate; adipate dioctyl; dusostearyl adipate; dioctyl maleate; glyceryl undecyleneate; octyldodecyl stearoyl stearate; pentaerythrityl monoricinoleate; pentaerythrityl tetrapelargonate; pentaerythrityl tetraisostearate; pentaerythrityl tetraoctanoate; pentaerythrityl dicaprylate glycol; propylene glycol dicaprate; tridecyl erucate; triisopropyl citrate; triisostearyl citrate; glyceryl trilactate; glyceryl trioctanoate; trioctyldodecyl citrate; trioleyl citrate; propylene glycol dioctanoate; neopentyl glycol diheptanoate; diethylene glycol diisononanoate and polyethylene glycol distearates

[0068] Among the esters mentioned above, it is preferable to use ethyl, isopropyl, myristyle, cetyl or stearyl palmitate, 2-ethylhexyl palmitate, 2-octyldecyl palmitate, alkyl myristates such as isopropyl, butyl, cetyl or 2-octyldodecyl myristate, hexyl stearate, butyl stearate, isobutyl stearate; dioctyl malate, hexyl laurate, 2-hexyldecyl laurate, isononyl isonanoate or cetyl octanoate.

[0069] The composition applied in the process according to the present invention may also include, as a fatty acid ester, sugar esters and C6 to C30 fatty acid diesters, and preferably C2 to C22. It should be noted that the term "sugar" refers to oxygenated hydrocarbon compounds containing several alcohol functional groups, with or without aldehyde or ketone functional groups, and comprising at least four carbon atoms. These sugars may be monosaccharides, oligosaccharides, or polysaccharides.

[0070] Examples of suitable sugars that can be mentioned include sucrose, glucose, galactose, ribose, fucose, maltose, fructose, mannose, arabinose, xylose and lactose, and their derivatives, in particular alkylated derivatives, such as methyl derivatives, for example methylglucose.

[0071] Sugar esters of fatty acids can be selected, in particular, from the group comprising the esters or mixtures of esters of sugars described above and of linear or branched fatty acids, saturated or unsaturated in C6 to C30 and preferably in Ci2 to C22. If they are unsaturated, these compounds may comprise one to three conjugated or non-conjugated carbon-carbon double bonds.

[0072] Esters according to this alternative form can also be chosen from mono-, di-, tri- and tetraesters and polyesters, and their mixtures.

[0073] These esters may be, for example, oleates, laurates, palmitates, myristates, behenates, cocoates, stearates, linoleates, linolenates, caprates or arachidonates, or mixtures thereof such as, in particular, mixed oleate / palmitate, oleate / stearate or palmitate / stearate esters.

[0074] More particularly, mono- and diesters are used and, in particular, mono- or di-oleate, -stearate, -behenate, -oleate / palmitate, -linoleate, -linolenate or -oleate / stearate of sucrose, glucose or methylglucose.

[0075] An example can be cited as the product marketed under the name Glucate® DO by the company Amerchol, which is a methylglucose dioleate.

[0076] Examples of esters or mixtures of sugar esters of fatty acids that may also be mentioned:

[0077] - the products marketed as F160, F140, Fl 10, F90, F70 and SL40 by Crodesta, designating respectively sucrose palmitate / stearate consisting of 73% monoester and 27% di- and triester, 61% monoester and 39% di-, tri- and tetraester, 52% monoester and 48% di-, tri- and tetraester, 45% monoester and 55% di-, tri- and tetraester, and 39% monoester and 61% di-, tri- and tetraester, and sucrose monolaurate;

[0078] - products marketed in the form of Ryoto sugar esters, for example referenced B370 and corresponding to sucrose behenate formed of 20% monoester and 80% diester, triester and polyester;

[0079] - sucrose monodipalmitate / stearate marketed by the company Goldschmidt under the name Tegosoft® PSE.

[0080] The silicones that can be used according to the invention can be in the form of oils, waxes, resins or gums.

[0081] Preferably, the silicone is chosen from polydialkylsiloxanes, in particular polydimethylsiloxanes (PDMS), and organomodified polysiloxanes comprising at least one functional group chosen from amino groups, aryl groups and alkoxy groups.

[0082] Organopolysiloxanes are defined in more detail in Chemistry and Technology of Silicones (1968) by Walter Noll, Academy Press. They can be volatile or non-volatile.

[0083] When volatile, silicones are particularly chosen from those having a boiling point between 60 °C and 260 °C, and, more particularly, from:

[0084] (i) cyclic polydialkylsiloxanes comprising 3 to 7 and preferably, of 4 to 5 silicon atoms. This includes, for example, octamethylcyclotetrasiloxane marketed in particular under the name Volatile Silicone® 7207 by Unioncarbure or Silbione® 70045 V2 by Rhodia, decamethylcyclopentasiloxane marketed under the name Volatile Silicone® 7158 by Unioncarbure, Silbione®70045 V5 by Rhodia and their mixtures.

[0085] We can also mention dimethylsiloxane / methylalkylsiloxane type cyclocopolymers, such as Silicone® Volatile FZ 3109 marketed by Unioncarbure, having the formula: CH3 -If “O““

[0086] Other examples include mixtures of cyclic polydialkylsiloxanes with organosilicon compounds, such as the mixture of octamethylcyclotetrasiloxane and tetramethylsilylpentaerythritol (50 / 50) and the mixture of octamethylcyclotetrasiloxane and oxy-1,r-bis(2,2',2',2',3,3'-hexatrimethylsilyloxy)neopentane; and

[0087] (ii) linear volatile polydialkylsiloxanes containing 2 to 9 silicon atoms and having a viscosity less than or equal to 5 x 10⁶ m² / s at 25 °C. An example is decamethyltetrasiloxane, marketed notably under the name SH 200 by Toray Silicone. Silicones belonging to this category are also described in the article published in Cosmetics and Toiletries, Vol. 91, Jan. 1976, pp. 27–32, Todd & Byers, “Volatile Silicone Fluids for Cosmetics”.

[0088] It is preferable to use non-volatile polydialkylsiloxanes, polydialkylsiloxane gums and resins, polyorganosiloxanes modified with the above organofunctional groups and mixtures thereof.

[0089] These silicones are more particularly selected from among the polydialkylsiloxanes, among which the main examples are polydimethylsiloxanes containing trimethylsilyl terminal groups. The viscosity of the silicones is measured at 25 °C in accordance with ASTM 445 Annex C.

[0090] Among these polydialkylsiloxanes, the following commercial products may be cited, without limitation:

[0091] - Silbione oils from ranges 47 and 70 047 or Mirasil oils marketed by Rhodia, for example oil 70 047 V 500 000;

[0092] - the oils from the Mirasil range marketed by the company Rhodia;

[0093] - oils from the 200 series of Dow Corning, such as DC200 with a viscosity of 60,000 mm² / s

[0094] - Viscasil® oils from General Electric and certain oils from the SF range (SF 96, SF 18) from General Electric.

[0095] We can also mention polydimethylsiloxanes having dimethylsilanol terminal groups known as dimethiconol (CTFA), such as the oils in the Rhodia 48 range.

[0096] In this category of polydialkylsiloxanes, we can also mention the products marketed under the names Abil Wax® 9800 and 9801 by the company Goldschmidt, which are poly(Ci-C2o) dialkylsiloxanes.

[0097] The silicone gums that can be used according to the invention are, in particular, polydialkylsiloxanes and preferably polydimethylsiloxanes having high number-average molecular weights between 200,000 and 1,000,000, used alone or in a mixture in a solvent. This solvent can be selected from volatile silicones, polydimethylsiloxane oils (PDMS), polyphenylmethylsiloxane oils (PPMS), isoparaffins, polyisobutylenes, methylene chloride, pentane, dodecane and tridecane or mixtures thereof.

[0098] Products that can be used more particularly in accordance with the invention are mixtures such as:

[0099] - mixtures formed from a polydimethylsiloxane or a dimethiconol (CTFA) hydroxy-terminated and a cyclic polydimethylsiloxane, also known as cyclomethicone (CTFA), such as the Q2 1401 product marketed by Dow Corning;

[0100] - mixtures of polydimethylsiloxane gum and cyclic silicone, such as the product SF 1214 Silicone Fluid from the company General Electric; this product is an SF 30 gum corresponding to a dimethicone, having a number average molecular weight of 500,000, dissolved in oil SF 1202 Silicone Fluid corresponding to decamethylcyclopentasilane;

[0101] - mixtures of two PDMS of different viscosities and, more particularly, of a PDMS rubber and a PDMS oil, such as General Electric's SF 1236. SF 1236 is a mixture of SE 30 rubber, as defined above, with a viscosity of 20 m² / s, and SF 96 oil with a viscosity of 5 x 10⁻⁶ m² / s. This product preferably contains 15% SE 30 rubber and 85% SF 96 oil.

[0102] The organopolysiloxane resins that can be used according to the invention are cross-linked siloxane systems containing the following units:

[0103] R2SiO2 / 2, RjSiOiÆ, RSiO2 / 2 and SiO4 / 2,

[0104] in which R represents an alkyl containing 1 to 16 carbon atoms. Among these products, those that are particularly preferred are those in which R designates a lower alkyl group in CrC4, more particularly the methyl.

[0105] Mention may be made, among these resins, of the product marketed under the name Dow Corning 593 or of those marketed under the name Silicone Fluid SS 4230 and SS 4267 by General Electric, which are silicones having a dimethyl / trimethylsiloxane structure.

[0106] We can also mention trimethylsiloxysilicate type resins, marketed in particular under the references X22-4914, X21-5034 and X21-5037 by Shin-Etsu.

[0107] The organo-modified silicones that can be used in accordance with the present invention are silicones as defined above and comprise in their structure one or more organofunctional groups attached via a hydrocarbon group.

[0108] Organomodified silicones can be polydiarylsiloxanes, in particular polydiphenylsiloxanes, and polyalkylarylsiloxanes functionalized with the organofunctional groups mentioned above.

[0109] Polyalkylarylsiloxanes are particularly chosen from linear and / or branched polydimethyl / methylphenylsiloxanes and polydimethyl / diphenylsiloxanes with a viscosity ranging from 1x105 to 5x102 m2 / s at 25 °C.

[0110] Among these polyalkylarylsiloxanes, the products marketed under the following names are examples that can be cited:

[0111] - Silbione® oils from the 70 641 range of Rhodia;

[0112] - The oils from the Rhodorsil® 70 633 and 763 ranges from Rhodia;

[0113] - Dow Corning 556 Cosmetic Grade Fluid oil from Dow Corning;

[0114] - silicones from the PK range of Bayer, such as product PK20;

[0115] - silicones from the PK range of Bayer, such as the product PH1000;

[0116] - certain oils in the General Electric SF range, such as SF 1023, SF 1154, SF 1250 and SF 1265.

[0117] Among organomodified silicones, we can also mention polyorganosiloxanes, in particular:

[0118] - substituted or unsubstituted amino groups, such as products marketed under the names GP 4 Silicone Fluid and GP 7100 by the Genesee company or the products marketed under the names Q2 8220 and Dow Corning 929 or 939 by the Dow Corning company. The substituted amino groups are, in particular, the Ci-C4 aminoalkyl groups;

[0119] - alkoxylated groups, such as the product marketed under the name Silicone Copolymer F-755 by SWS Silicones and Abil Wax® 2428, 2434 and 2440 by Goldschmidt.

[0120] The silicones that can be used in the composition of the present invention can also be chosen from amino silicones.

[0121] The term “aminosilicone” means any silicone including at least one primary, secondary or tertiary amine or a quaternary ammonium group.

[0122] The weight-average molecular masses of these aminosilicones can be measured by gel permeation chromatography (GPC) at room temperature (25 °C), in polystyrene equivalents. The columns used are Styragel q columns. The eluent is THF and the flow rate is 1 ml / min. 200 ql of a 0.5% silicone solution % by weight in THF are injected. Detection is performed by refractometry and UV.

[0123] Throughout the text below, the term "silicone" is intended to designate, in accordance with generally accepted usage, any organosilicon polymer or oligomer of linear or cyclic, branched or cross-linked structure, of variable molecular weight, obtained by polymerization and / or polycondensation of properly functionalized silanes, and formed essentially from a repetition of principal units in which silicon atoms are linked together via oxygen atoms (siloxane bond -Si-O-Si-), optionally substituted hydrocarbon groups being linked by a carbon atom to said silicon atoms. The most common hydrocarbon groups are alkyl groups, in particular alkyl groups in the form of Ci-Cio and, in particular, methyl and fluoroalkyl groups, the alkyl portion of which is in the form of Ci-Cio, and aryl groups and, in particular, phenyl groups.

[0124] Suitable aminosilicones that can be used in accordance with the present invention include, but are not limited to, volatile and non-volatile, cyclic, linear and branched aminosilicones, with a viscosity ranging from 5x106 to 2.5 m2 / s at 25 °C, for example from 1x105 to 1 m2 / s.

[0125] Preferably, the aminosilicones are chosen from:

[0126] a) polysiloxanes corresponding to formula (I):

[0127] in which x' and y' are integers such that the average molecular mass by weight (Mw) is between 5000 and 500,000 g / mol;

[0128] b) aminosilicones corresponding to formula (ii):

[0129] R'aG3 a-Si(OSiG2)n-(OSiGbR'2b)mO-SiG3 a-R'a (II)

[0130] in which:

[0131] - G, which may be the same or different, designates a hydrogen atom or a phenyl, OH, alkyl in C1-C8> for example a methyl group, or alkoxy in C1-C8> for example methoxy,

[0132] - a and a', which may be identical or different, denote 0 or an integer from 1 to 3, in particular 0, provided that at least one of a and a' is equal to zero,

[0133] - b denotes 0 or 1, in particular, 1,

[0134] - m and n are numbers such that the sum (n + m) ranges from 1 to 2000 and, in particular, from 50 to 150, n possibly denoting a number from 0 to 1999 and in particular from 49 to 149, and m possibly denoting a number from 1 to 2000 and in particular from 1 to 10 and

[0135] - R', which may be identical or different, denotes a monovalent radical of formula -CqH2qL where q is a number from 2 to 8 and L is an optionally quaternized amine group chosen from the following groups:

[0136] • -NR"-QN(R") 2,

[0137] • -N(R") 2

[0138] . -N+(R") 3 A,

[0139] . -N+H(R")2 A,

[0140] . -N+H2(R") A ,

[0141] . -NR"-Q-N+(R")H2 A,

[0142] . -NR"-Q-N+(R")2H A and

[0143] . -NR"-Q-N+(R") 3 A ,

[0144] wherein R", which may be the same or different, denotes hydrogen, phenyl, benzyl or a saturated monovalent hydrocarbon radical, for example a Cr C20 alkyl radical; Q denotes a linear or branched group of formula CrH2r, r being an integer from 2 to 6, preferably from 2 to 4; and A represents a cosmetically acceptable anion, in particular a halide such as fluorine, chloride, bromide or iodide.

[0145] According to a first embodiment, the aminosilicones corresponding to formula (ii) are chosen from the silicones called "trimethylsilyl amodimethicone", corresponding to formula (III):

[0146]

[0147] in which m and n are numbers such that the sum (n + m) goes from 1 to 2000 and, in particular, from 50 to 150, n possibly designating a number from 0 to 1999 and in particular from 49 to 149, and m possibly designating a number from 1 to 2000 and in particular from 1 to 10. According to a second embodiment, the aminosilicones corresponding to formula (ii) are chosen from the silicones of formula (IV) below:

[0148]

[0149]

[0150]

[0151]

[0152]

[0153]

[0154] Or : - m and n are numbers such that the sum (n + m) ranges from 1 to 1000, specifically from 50 to 250 and, more particularly, from 100 to 200; n denotes a number from 0 to 999, specifically from 49 to 249 and, more particularly, from 125 to 175, and m denotes a number from 1 to 1000, specifically from 1 to 10 and, more particularly, from 1 to 5 and - Ri, R2 and R3, which may be identical or different, represent a hydroxyl or alkoxy radical in Ci-C4, at least one of the radicals Ri to R3 designating an alkoxy radical. Preferably, the alkoxy radical is a methoxy radical. The hydroxy / alkoxy molar ratio varies preferably from 0.2:1 to 0.4:1, preferably from 0.25:1 to 0.35:1 and is most particularly equal to 0.3:1. The average molecular mass by weight (Mw) of these silicones is preferably from 2000 to 1,000,000 g / mol and, more particularly, from 3500 to 200,000 g / mol. According to a third embodiment, the aminosilicones corresponding to formula (ii) are chosen from the silicones of formula (V) below:

[0155] where:

[0156] - p and q are numbers such that the sum (p + q) goes from 1 to 1000, in particular, from 50 to 350 and, more particularly, from 150 to 250; p denotes a number from 0 to 999, in particular, from 49 to 349 and, more particularly, from 159 to 239, and q denotes a number from 1 to 1000, in particular, from 1 to 10 and, more particularly, from 1 to 5 and

[0157] - Ri and R2, which are different, represent an alkoxy or hydroxyl radical or a Cr C4> at least one of the radicals Ri or R2 designating an alkoxy radical.

[0158] Preferably, the alkoxy radical is a methoxy radical.

[0159] The hydroxy / alkoxy molar ratio generally varies from 1:0.8 to 1:1.1, preferably from 1:0.9 to 1:1 and, more particularly, is equal to 1:0.95.

[0160] The average molecular mass by weight (Mw) of silicone is preferably from 2000 to 200,000 g / mol, better still from 5000 to 100,000 g / mol and, in particular, from 10,000 to 50,000 g / mol.

[0161] Commercial products comprising structural silicones (IV) or (V) may include in their composition one or more other aminosilicones, the structure of which is different from that of formula (IV) or (V).

[0162] A product containing structural (IV) aminosilicones is marketed by the company Wacker under the name Belsil® ADM 652.

[0163] A product containing structural aminosilicones (V) is marketed by Wacker under the name Fluid WR 1300®. Another product containing structural aminosilicones (IV) is marketed by Wacker under the name Belsil ADM LOG 1®.

[0164] When these aminosilicones are used, a particularly advantageous embodiment is to use them in the form of an oil-in-water emulsion. The oil-in-water emulsion may comprise one or more surfactants. The surfactants may be of any nature, but are preferably cationic and / or nonionic. The number-average size of the silicone particles in the emulsion generally ranges from 3 nm to 500 nanometers. Preferably, in particular, in the form of aminosilicones of Formula (V) uses microemulsions with an average particle size ranging from 5 nm to 60 nm (inclusive) and, more specifically, from 10 nm to 50 nm (inclusive). Thus, aminosilicone microemulsions of formula (V), marketed under the names Finish CT 96 E® or SLM 28020® by Wacker, can be used according to the invention.

[0165] According to a fourth embodiment, the aminosilicones corresponding to formula (ii) are chosen from the silicones of formula (VI) below:

[0166] where:

[0167] - m and n are numbers such that the sum (n + m) ranges from 1 to 2000 and, in particular, from 50 to 150, where n represents a number from 0 to 1999, and in particular from 49 to 149, and m represents a number from 1 to 2000, and in particular from 1 to 10 and

[0168] - A denotes a linear or branched alkylene radical containing 4 to 8 atoms of carbon and preferably 4 carbon atoms. This radical is preferably linear.

[0169] The average molecular mass by weight (Mw) of these aminosilicones will preferably be from 2000 to 1,000,000 g / mol and, more particularly, from 3500 to 200,000 g / mol.

[0170] A silicone corresponding to this formula is, for example, Dow Corning's Xiameter MEM 8299 emulsion.

[0171] According to a fifth embodiment, the aminosilicones corresponding to formula (ii) are chosen from the silicones of formula (VII) below:

[0172] where:

[0173] - m and n are numbers such that the sum (n + m) ranges from 1 to 2000 and, in particular, from 50 to 150, n possibly denoting a number from 0 to 1999 and in particular from 49 to 149, and m possibly denoting a number from 1 to 2000 and in particular from 1 to 10 and

[0174] - A denotes a linear or branched alkylene radical containing 4 to 8 atoms of carbon and preferably 4 carbon atoms. This radical is preferably branched.

[0175] The average molecular mass by weight (Mw) of these aminosilicones will preferably be from 500 to 1,000,000 g / mol and, more particularly, from 1,000 to 200,000 g / mol.

[0176] A silicone corresponding to this formula is, for example, Dow Corning's DC2-8566 Amino Fluid;

[0177] c) aminosilicones corresponding to formula (VIII):

[0178] where:

[0179] - R5 represents a monovalent hydrocarbon radical containing from 1 to 18 atoms of carbon, and, in particular, an alkyl radical in Ci-Ci8 or alkenyl in C2-Ci8> for example methyl;

[0180] - R6 represents a divalent hydrocarbon radical, in particular an alkylene radical in C1-C18 or a divalent alkylene radical in CrCi8, for example CrC8, linked to Si by a SiC bond;

[0181] - Q is an anion such as a halide ion, in particular chloride, or an acid salt organic, in particular acetate;

[0182] - r represents an average statistical value ranging from 2 to 20 and, in particular, from 2 to 8 and

[0183] - s represents an average statistical value ranging from 20 to 200 and, in particular, from 20 to 50.

[0184] These aminosilicones are described in particular in US patent 4,185,087.

[0185] d) quaternary ammonium silicones of formula (IX): (DC)

[0186] where:

[0187] - R7, which may be identical or different, represent a hydrocarbon radical monovalent containing from 1 to 18 carbon atoms, and, in particular, an alkyl radical in Ci-Cig, an alkenyl radical in C2-Ci8 or a ring comprising 5 or 6 carbon atoms, for example methyl;

[0188] - R6 represents a divalent hydrocarbon radical, in particular an alkylene radical in C1-C18 or a divalent Ci-Ci8 alkylene radical, for example Ci-C8, linked to Si by a SiC bond;

[0189] - R8, which may be identical or different, represent a hydrogen atom, a monovalent hydrocarbon radical containing from 1 to 18 carbon atoms, and, in particular, a Ci-Ci8 alkyl radical, a C2-Ci8 alkenyl substituent or a -R6-NHCOR7 radical;

[0190] - X is an anion such as a halide ion, in particular chloride, or an acid salt organic, including acetate and

[0191] - r represents an average statistical value ranging from 2 to 200 and, in particular, from 5 at 100.

[0192] These aminosilicones are described in particular in patent application EP-A 0 530 974.

[0193] e) aminosilicones of formula (X): (X)

[0194] where:

[0195] - Rb R2, R3 and R4, which may be identical or different, designate a radical alkyl group in C1-C4 or a phenyl group,

[0196] - R5 designates an alkyl radical in CrC4 or a hydroxyl group,

[0197] - n is an integer in the range of 1 to 5.

[0198] - m is an integer in the range of 1 to 5 and

[0199] - x is chosen such that the amine index is from 0.01 to 1 meq / g;

[0200] f) multiblock polyoxyalkylated aminosilicones, of the type (AB)n, A being a block of polysiloxane and B being a polyoxyalkylated block comprising at least one amine group.

[0201] Said silicones are preferably formed from repeating units having the following general formulas:

[0202] [-(SiMe2O)xSiMe2-RN(R")-R'-O(C2H4O)a(C3H6O)b-R'-N(H)-R-]

[0203] or

[0204] [-(SiMe2O)xSiMe2-RN(R")-R'-O(C2H4O)a(C3H6O)b-]

[0205] where:

[0206] - a is an integer greater than or equal to 1, preferably from 5 to 200 and, more particularly, from 10 to 100;

[0207] - b is an integer between 0 and 200, preferably from 4 to 100 and, more specifically, between 5 and 30;

[0208] - x is an integer ranging from 1 to 10,000 and, more particularly, from 10 to 5,000;

[0209] - R" is a hydrogen atom or a methyl;

[0210] - R, which may be identical or different, represents a hydrocarbon radical linear or branched divalent C2-Ci2> optionally comprising one or more heteroatoms such as oxygen; preferably, R, which may be identical or different, denote an ethylene radical, a linear or branched propylene radical, a linear or branched butylene radical, or a CH2CH2Och2CH(OH) CH2-CH radical; preferably, R denotes a CH2CH2CH2OCH2CH(OH) CH2-CH radical; and

[0211] - R, which may be identical or different, represents a hydrocarbon radical linear or branched divalent C2-Ci2> optionally comprising one or more heteroatoms such as oxygen; preferably, R, which may be identical or different, denote an ethylene radical, a linear or branched propylene radical, a linear or branched butylene radical or a CH2CH2CH2OCH2CH(OH)CH2 radical; preferably, R denote a -CH(CH3)-CH2- radical.

[0212] The siloxane blocks preferably represent 50% by moles and 95% by moles of the total weight of the silicone, more particularly from 70% by moles to 85% by moles.

[0213] The amine content is preferably between 0.02 and 0.5 meq / g of copolymer in a 30% dipropylene glycol solution, more particularly between 0.05 and 0.2.

[0214] The average molecular mass by weight (Mw) of silicone is preferably between 5000 and 1,000,000 g / mol and, more particularly, between 10,000 and 200,000 g / mol.

[0215] Reference may in particular be made to silicones marketed under the name Silsoft A-843 or Silsoft A+ by Momentive.

[0216] g) aminosilicones of formulas (XI) and (XII): N* (XI)

[0217] where:

[0218] - R, R' and R", which may be identical or different, denote an alkyl group in C1-C4 or a hydroxyl group,

[0219] - A denotes a C3 alkylene radical and

[0220] - m and n are numbers such that the average molecular mass in weight of the The compound value is between 5000 and 500,000 (XII)

[0221] where:

[0222] - x and y are numbers ranging from 1 to 5000; preferably, x ranges from 10 to 2000 and Better still, from 100 to 1000; preferably, from 1 to 100;

[0223] - Ri and R2, which may be identical or different, preferably identical, denote a linear or branched, saturated or unsaturated alkyl group comprising from 6 to 30 carbon atoms, preferably from 8 to 24 carbon atoms and, even better, from 12 to 20 carbon atoms; and

[0224] - A denotes a linear or branched alkylene radical containing 2 to 8 atoms of carbon.

[0225] Preferably, A comprises from 3 to 6 carbon atoms, better still, 4 carbon atoms; preferably, A is branched.

[0226] In particular, the following divalent groups may be mentioned:

[0227] -CH2CH2CH2- and -CH2CH(CH3)CH2-,

[0228] Preferably, Ri and R2 are independent saturated linear alkyl groups comprising 6 to 30 carbon atoms, preferably 8 to 24 carbon atoms and, in particular, 12 to 20 carbon atoms; examples include, in particular, dodecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl, nonadecyl and eicosyl groups; and, preferably, Ri and R, which may be identical or different, are selected from the hexadecyl (cetyl) and octadecyl (stearyl) groups.

[0229] Aminosilicones are preferably of formula (XII) with:

[0230] - x ranging from 10 to 2000 and, in particular, from 100 to 1000;

[0231] - ranging from 1 to 100;

[0232] - A comprising from 3 to 6 carbon atoms and, in particular, 4 carbon atoms; Preferably, A is branched; more particularly, A is chosen from the following divalent groups: -CH2CH2CH2- and -CH2CH(CH3) CH2- and

[0233] - Ri and R2 being independently saturated linear alkyl groups comprising 6 to 30 carbon atoms, preferably 8 to 24 carbon atoms and, in particular, 12 to 20 carbon atoms; chosen especially from the dodecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl, nonadecyl and eicosyl groups; preferably, Ri and R, which may be identical or different, are chosen from the hexadecyl (cetyl) and octadecyl (stearyl) groups.

[0234] A preferred silicone of formula (XII) is bis-cetearyl amodimethicone. In particular, aminosilicone marketed under the name Silsoft AX by Momentive may be mentioned.

[0235] h) polysiloxanes and, in particular, polydimethylsiloxanes, including primary amine groups at one end of a chain or on side chains, such as those of formula (XIV), (XV) or (XVI):

[0236] or (XV)

[0237] or

[0238] In formula (XIV), the values ​​of n and m are such that the average molecular mass by weight of aminosilicon is between 1000 and 55,000.

[0239] Examples of amines of formula (XIV) include the products marketed under the names AMS-132, AMS-152, AMS-162, AMS-163, AMS-191 and AMS-1203 by Gelest and KF-8015 by Shin-Etsu.

[0240] In formula (XV), the values ​​of n and m are such that the average molecular mass by weight of the aminosilicon is between 500 and 3000.

[0241] As examples of amines of formula (XV), mention may be made of the products marketed under the names MCR-A11 and MCR-A12 by the company Gelest.

[0242] In formula (XVI), the values ​​of n and m are such that the average molecular mass by weight of aminosilicon is between 500 and 50,000.

[0243] Examples of amines of formula (XVI) include aminopropyl phenyl trimethicone marketed under the name DC 2-2078 Fluid by Dow Corning.

[0244] I) and mixtures of the latter.

[0245] Preferably, the aminosilicones are selected from aminosilicones of formulas (II), (XII) and (XVI) and mixtures thereof, or even better, selected from aminosilicones of formula (XII) and their mixtures, and even better raminosilicone (b) is bis-cetearyl-amodimethicone.

[0246] Preferably, the additional fatty substance(s), other than fatty acid triglycerides (ii) containing 6 to 16 carbon atoms, are selected from fatty alcohols, fatty esters, triglyceride-type vegetable oils other than fatty acid triglycerides (ii), aminosilicones and mixtures thereof.

[0247] The total amount of the additional fatty substance(s), other than fatty acid triglycerides (ii) containing 6 to 16 carbon atoms, when present in the composition according to the invention, is preferably from 0.5 to 20% by weight, and better still, from 1 to 15% by weight, even better still, from 1.5 to 10% by weight relative to the total weight of the composition.

[0248] The total quantity of fatty substances (i.e. the sum of the total quantity of fatty acid triglycerides) (ii) containing 6 to 16 carbon atoms and the total quantity of the optional additional fatty substance(s) present in the composition according to the present invention, preferably ranges from 1 to 35% by weight, and better still, from 5 to 25% by weight, relative to the total weight of the composition.

[0249] The weight ratio (Rb) between the total amount of the additional fatty substance(s), difference between the triglycerides of fatty acids (ii) containing 6 to 16 carbon atoms, and the total amount of triglycerides of fatty acids (ii) containing 6 to 16 carbon atoms is preferably greater than or equal to 1, better still, greater than or equal to 1.5, and better still greater than or equal to 2. Cationic surfactants

[0250] The composition applied in the process according to the present invention may further comprise one or more cationic surfactants.

[0251] The term "cationic surfactant" refers to a surfactant that can be positively charged when contained in the compositions as disclosed. This surfactant may carry one or more permanent positive charges or may contain one or more functional groups that are cationizable in the composition as disclosed.

[0252] The cationic surfactant(s) is / are preferably chosen from primary, secondary or tertiary fatty amines, which are optionally polyoxyalkylated, or their salts, and quaternary ammonium salts, and mixtures thereof.

[0253] Fatty amines generally comprise at least one C8-to-C3o hydrocarbon chain.

[0254] The cationic surfactant(s) that can be used in the composition of the present invention are preferably chosen from the following quaternary ammonium salts and mixtures thereof:

[0255] - quaternary ammonium salts corresponding to the general formula (XVII) below- below:

[0256] wherein the groups R28 to Rn, which may be identical or different, represent an aliphatic group, linear or branched, comprising from 1 to 30 carbon atoms, or an aromatic group such as aryl or alkylaryl, at least of the groups R28 to R3i designating a group comprising from 8 to 30 carbon atoms, preferably from 12 to 24 carbon atoms, the aliphatic groups being able to include heteroatoms such as oxygen, nitrogen, sulfur and halogens. The aliphatic groups are chosen, for example, from the following: alkyl Ci to C30, alkoxy Ci to C30, polyoxy alkylene (C2-C6), alkylamide Ci to C30, alkylamido (Ci2-C22) alkyl (C2-C6), alkyl acetate (Ci2-C22), and hydroxyalkyl groups in Ci to C30; X is an anion chosen from the group of halides, phosphates, acetates, lactates, alkylsulfonates (C1-C4) and alkyl (C1-C4) - or alkylalkylsulfonates (Ci-C).

[0257] Among quaternary ammonium salts of formula (XVII), preference is given, on the one hand, to tetraalkylammonium salts, for example, dialkyldimethylammonium or alkyltrimethylammonium salts whose alkyl group contains approximately 12 to 22 carbon atoms, in particular, behenyltrimethylammonium, distearyldimethylammonium, cetyltrimethylammonium or benzyldimethylstearylammonium salts, or, on the other hand, to palmitylamidopropyltrimethylammonium salt, stearamidopropyltrimethylammonium salt, stearamidopropyldimethylcetearylammonium salts or stearamidopropyldimethyl(myristyle acetate)ammonium salts marketed under the name Ceraphy® 70 by the Van Dyk company. It is preferable, in particular, to use the chloride salts of these compounds;

[0258] - quaternary ammonium salts of imidazoline, for example those of formula (XVIII) below: (XVIII)

[0259] where:

[0260] - R32 represents an alkenyl or alkyl group comprising 8 to 30 atoms of carbon, for example, derivatives of tallow fatty acids,

[0261] - R33 represents a hydrogen atom, a C1 to C4 alkyl group or a group alkenyl or alkyl comprising 8 to 30 carbon atoms,

[0262] - R34 represents an alkyl group in the C4 to C1 position,

[0263] - R35 represents a hydrogen atom or an alkyl group in C1 to C4,

[0264] - X is an anion chosen from the group of halides, phosphates, acetates, lactates, alkyl sulfates and alkyl- or alkylarylsulfonates, the alkyl and aryl groups of which preferably comprise, respectively, from 1 to 20 carbon atoms and from 6 to 30 carbon atoms.

[0265] Preferably, R32 and R33 denote a mixture of alkenyl or alkyl groups comprising 12 to 21 carbon atoms, for example, tallow fatty acid derivatives, R34 denotes a methyl group and R35 denotes a hydrogen atom. Such a product is marketed, for example, under the name Rewoquat® W 75 by the company Rewo;

[0266] - di- or tri-quaternary ammonium salts, in particular, of formula (XIX):

[0267] where:

[0268] - R36 designates an alkyl group comprising approximately 16 to 30 atoms of carbon, which is optionally hydroxylated and / or interrupted by one or more oxygen atoms;

[0269] - R37 is selected from hydrogen, an alkyl radical comprising 1 to 4 atoms of carbon or a group (R36a) (Rsva) IR",") N-(CH2) 3,

[0270] - R36a, R37a, R38a, R38, R39, R40 and R41, which may be identical or different, are chosen from hydrogen and an alkyl radical comprising 1 to 4 carbon atoms and

[0271] - X is an anion selected from the group of halides, acetates, phosphates, nitrates and methyl sulfates.

[0272] Such compounds are, for example, Finquat CT-P, marketed by Finetex (Quaternium 89), and Finquat CT, marketed by Finetex (Quaternium 75),

[0273] - quaternary ammonium salts containing at least one ester function, such as those with formula (XX) below: ii L x" Kh—C-— N- r42 XX

[0274] where:

[0275] - R42 is selected from the alkyl groups in C1 to C6 and the hydroxyalkyl groups or dihydroxyalkyl in C1 to C6;

[0276] - R43 is chosen from the following elements:

[0277] - the O group r4—c—

[0278] - the R47 groups which are linear or branched hydrocarbon groups, saturated or unsaturated in C22 at Ci

[0279] a) a hydrogen atom;

[0280] - R45 is chosen from the following elements:

[0281] - the Q group

[0282] - the R^ groups which are linear or branched hydrocarbon groups, saturated or unsaturated in C1 to C6>

[0283] a) a hydrogen atom;

[0284] - R44, R46 and Rk, which may be identical or different, are chosen from the linear or branched hydrocarbon groups, saturated or unsaturated in C7 to C21;

[0285] - r, s and t, which may be identical or different, are integers ranging from 2 to 6;

[0286] - y is an integer between 1 and 10;

[0287] - x and z, which can be identical or different, are integers ranging from 0 to 10;

[0288] - X is a simple or complex anion and organic or inorganic;

[0289] provided that the sum x + y + z is between 1 and 15, in this case when x is equal to 0, R4Î denotes R47 and when z is equal to 0, R45 denotes R47.

[0290] The alkyl groups in R42 can be linear or branched and, more particularly, linear.

[0291] Preferably, R42 designates a methyl, ethyl, hydroxyethyl or dihydroxypropyl group, and, more particularly, a methyl or ethyl group.

[0292] Advantageously, the sum x + y + z goes from 1 to 10.

[0293] When R43 is a hydrocarbon group in R47, it may be long and contain from 12 to 22 carbon atoms, or it may be short and contain from 1 to 3 carbon atoms.

[0294] When R^ is a hydrocarbon group in R49, it preferably contains 1 to 3 carbon atoms.

[0295] Advantageously, R44, R46 and Rts, which may be identical or different, are chosen from linear or branched hydrocarbon groups, saturated or unsaturated in Ch to C21 and, more particularly, from linear or branched alkyl and alkenyl groups, saturated or unsaturated in Ci 1 to C2i.

[0296] Preferably, x and z, which may be identical or different, are equal to 0 or 1.

[0297] Advantageously, y is equal to 1.

[0298] Preferably, r, s and t, which may be identical or different, are equal to 2 or 3, and even more particularly equal to 2.

[0299] The anion X⁻ is preferably a halide (chloride, bromide or iodide) or an alkyl sulfate, more particularly methyl. However, methanesulfonate, phosphate, nitrate, tosylate, an anion derived from an organic acid, such as acetate or lactate, or any other ammonium-compatible anion having an ester function may be used.

[0300] The anion X - is even more particularly methyl chloride or methyl sulfate.

[0301] The use is made more particularly in the composition of the colorant according to the invention of ammonium salts of formula (XX) where:

[0302] R42 designates a methyl or ethyl group;

[0303] x and y are equal to 1;

[0304] z is equal to 0 or 1;

[0305] r, s and t are equal to 2;

[0306] R4î is chosen from the following elements:

[0307] - the O group

[0308] - methyl, ethyl or hydrocarbon groups in CM to C22,

[0309] a) a hydrogen atom;

[0310] R45 is selected from the following elements:

[0311] - the O group c —

[0312] a) a hydrogen atom;

[0313] R44, R46 and R48, which may be identical or different, are chosen from the saturated or unsaturated and linear or branched hydrocarbon groups in Cn to Cp and preferably among saturated or unsaturated and linear or branched alkyl and alkenyl groups in Cn to Cp.

[0314] Advantageously, hydrocarbon groups are linear.

[0315] Examples that may be mentioned include compounds of formula (XX) such as salts of diiacyloxyethyldimethylammonium, diiacyloxyethylhydroxyethylmethylammonium, monoacyloxyethyldihydroxyethylmethylammonium, triacyloxyethylmethylammonium, and monoacyloxyethylhydroxyethyldimethylammonium (chloride or methyl sulfate in particular), and mixtures thereof. The acyl groups preferably contain 14 to 18 carbon atoms and are obtained most particularly from a vegetable oil such as palm oil or sunflower oil. When the compound contains several acyl groups, these groups may be identical or different.

[0316] These products are obtained, for example, by direct esterification of triethanolamine, triisopropanolamine, alkyldiethanolamine, or alkyldiisopropanolamine, which are optionally oxyalkylated, with C30 fatty acids or with mixtures of C30 fatty acids of vegetable or animal origin, or by transesterification of their methyl esters. This esterification is followed by quaternization with an alkylating agent such as an alkyl halide (preferably a methyl or ethyl halide), a dialkyl sulfate (preferably a methyl or ethylethyl sulfate), methyl methanesulfonate, methyl para-toluenesulfonate, glycol chlorohydrin, or glycerol chlorohydrin.

[0317] These compounds are marketed, for example, under the names Dehyquart® by Henkel, Stepanquat® by Stepan, Noxamium® by CECA or Rewoquat® WE 18 by Rewo-Witco.

[0318] Among these compounds, we can cite, in particular, dipalmitoylethylhydroxyethylmethylammonium methosulfate.

[0319] The composition applied in the process according to the present invention may contain, for example, a mixture of quaternary ammonium monoester, diester and triester salts, with a weight majority of diester salts.

[0320] Ammonium salts containing at least one ester functional group, as described in US-A-4 874 554 and US-A-4 137 180 patents, can also be used.

[0321] Behenoylhydroxypropyltrimethylammonium chloride marketed by KAO under the name Quatarmin BTC 131 can be used.

[0322] Preferably, ammonium salts containing at least one ester function contain two ester functions.

[0323] Among the quaternary ammonium salts containing at least one ester function, which can be used, it is preferable to use dipalmitoylethylhydroxyethylmethylammonium salts.

[0324] The cationic surfactants that may be present in the composition of the invention are preferably chosen from those of formula (XVII) and their mixtures, and even better, from behenyltrimethylammonium chloride and cetrimonium chloride.

[0325] The total quantity of the cationic surfactant(s), when present in the composition according to the invention, preferably ranges from 0.5 to 15% by weight and, even better, from 1 to 10% by weight, relative to the total weight of the composition.

[0326] The weight ratio (Rc) between the total quantity of fatty acid triglycerides (ii) containing 6 to 16 carbon atoms and the total quantity of cationic surfactant(s), when present in the composition according to the invention, is preferably greater than or equal to 1, better still, this weight ratio (Rc) is from 1 to 10, and better still from 1 to 5. Organic solvents

[0327] The composition applied in the process according to the present invention may further comprise one or more organic solvent(s).

[0328] Preferably, the organic solvent(s) is / are chosen from linear or branched monoalcohols comprising 1 to 8 carbon atoms and, even better, 1 to 4 carbon atoms, polyols, polyethylene glycols, aromatic alcohols and mixtures thereof.

[0329] Reference may in particular be made, by way of examples of organic solvents which may be used according to the invention, to the following: ethanol, propanol, butanol, isopropanol, isobutanol, propylene glycol, dipropylene glycol, isoprene glycol, butylene glycol, pentylene glycol, hexylene glycol, glycerol, sorbitol, benzyl alcohol, phenoxyethanol and mixtures thereof.

[0330] The total quantity of organic solvent(s), when present in the composition according to the invention, preferably ranges from 0.005 to 1% by weight, relative to the total weight of the composition. Water

[0331] The composition applied in the process according to the present invention may further comprise water.

[0332] The total quantity of water, which may be present in the composition according to the present invention, preferably ranges from 50 to 99% by weight, better still, from 55 to 95% by weight, and better still from 60 to 80% by weight, relative to the total weight of the composition. Additives

[0333] The composition used in the process according to the present invention may further comprise one or more additive(s) other than the compounds of the invention.

[0334] As additives that can be used in accordance with the invention, mention may be made of anionic, non-ionic or amphoteric surfactants, cationic, amphoteric, anionic or non-ionic polymers, anti-dandruff agents, anti-seborrheic agents, agents to prevent hair loss and / or to promote hair regrowth, vitamins and provitamins other than tocopherol, sunscreens, mineral or organic pigments, sequestering agents, plasticizers, solubilizers, mineral or organic thickeners, in particular polymeric thickeners, opacifiers or pearlescent agents, antioxidants, hydroxy acids, perfumes and preservatives.

[0335] It goes without saying that a person skilled in the art will take care to select this or these optional additional compound(s) in such a way that the advantageous properties intrinsically associated with the composition according to the invention are not, or not substantially, negatively affected by the envisaged addition(s).

[0336] The above additives can generally be present in an amount, for each of them, of between 0.001% and 20% by weight, relative to the total weight of the composition.

[0337] The pH of the composition according to the invention ranges from 7.5 to 10, preferably from 8 to 9.5, better still, from 8.5 to 9.

[0338] The pH of the composition can be adjusted to the desired value by means of commonly used alkalizing or acidifying agents. Examples of alkalizing agents are ammonia, alkanolamines, and mineral or organic hydroxides. Examples of acidifying agents are mineral or organic acids such as hydrochloric acid, orthophosphoric acid, sulfuric acid, carboxylic acids such as acetic acid, tartaric acid, citric acid, lactic acid, and sulfonic acids.

[0339] According to a preferred embodiment, the composition of the present invention further comprises one or more alkaline agents.

[0340] Among the alkaline agents that can be used in the present invention, mention may be made of aqueous ammonia, alkali metal, alkaline earth metal or Guanidine (bi)carbonates, alkanolamines, such as mono-, di- and triethanolamines and their derivatives, alkali metal or alkaline earth metal silicates, alkali metal or alkaline earth metal hydroxides, such as sodium or potassium hydroxide, and compounds of the following formula (XXI): z R / xx D N WN h / R,

[0341] in this formula (XXI) W is a linear or branched (Ci-C6) alkylene group, in particular propylene, optionally substituted by one or more hydroxyl groups; R6, R7, R8 and R9, which may be identical or different, represent a hydrogen atom or an alkyl radical in Ci-C or a hydroxyalkyl radical in C1-C4.

[0342] The organic alkali metal(s) are preferably selected from organic amines with a pKb at 25 °C of less than 12, preferably less than 10, and even better, less than 6. It should be noted that this is the pKb corresponding to the highest basicity functional group. Furthermore, the organic amines do not include any alkyl or alkenyl fatty chain comprising more than ten carbon atoms.

[0343] Preferably, the alkali agent(s) are chosen from aqueous ammonia, alkanolamines such as monoethanolamine or ethanolamine, carbonates, in particular guanidine carbonate, silicates, such as sodium silicate, and mixtures thereof. Process

[0344] The cosmetic process for treating smoothed keratin fibers, in particular human keratin fibers such as hair, preferably curly or frizzy hair, according to the present invention comprises the application of a cosmetic composition as defined above to the smoothed keratin fibers, in particular to the smoothed keratin fibers.

[0345] In the present invention, the term "keratin fibers" refers to human keratin fibers, and, in particular, human hair.

[0346] The cosmetic process of the invention is, in particular, a process for treating straightened hair, namely: hair previously straightened by any straightening method known to a person skilled in the art.

[0347] The cosmetic process of the invention includes a hair smoothing step, carried out prior to the application of a cosmetic composition as defined above.

[0348] Smoothing methods include a chemical method, such as opening the disulfide bonds -SS- of keratin by applying a reducing agent or by performing an anthionization operation, preferably anthionization.

[0349] The opening of the disulfide-SS bonds of keratin (keratocystin) is carried out 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 (oxidation step, also known as the fixing step) to the hair, which has been previously held under tension (for example, with rollers), so as to finally give the hair the desired shape. The new shape given to the hair by a chemical treatment such as the one described above is permanent and, in particular, resistant to washing with water or shampooing.

[0350] Lanthionization uses a composition containing a base belonging to the hydroxide family. It results in the replacement of disulfide bonds (-CH2-SS-CH2-) by lanthione bonds (-CH2-S-CH2-). This lanthionization operation involves two consecutive chemical reactions:

[0351] The first reaction consists of a beta elimination on cystine caused by a hydroxide ion, resulting in the breaking of this bond and the formation of dehydroalanine, as shown in the following reaction scheme. ''NH H^'^OQ<;"' ''NH HbC' II 0H I » I H—C—OH-S—S-CH—GH --------------------------G=CH, + fSl + S—GH—G—H i ' _ j. Cf" SNH Cf" O"" "NH ü''" 'NH cystine dehydroaiamne

[0352] The second reaction is a reaction of dehydroalanine with a thiol group. More specifically, the double bond formed in dehydroalanine is a reactive double bond. It can react with the thiol group of the released cysteine ​​residue to form a new bond known as a lanthionine bridge, bond, or residue. This second reaction is illustrated by the following reaction scheme. dehydroaSanine ianthionisw

[0353] Compositions that could be used to smooth keratin fibers preferably include a hydroxide, such as alkali metal hydroxide or alkaline earths, in particular, sodium hydroxide, lithium hydroxide, potassium hydroxide, calcium hydroxide and / or guanidine hydroxide.

[0354] Preferably, the pH of these compositions is equal to or greater than 10, better still, equal to or greater than 12.

[0355] Better still, the pH of said compositions ranges from 10 to 14, even better still, from 12 to 14.

[0356] The cosmetic process of the invention is, in particular, a process for strengthening smoothed keratin fibers, in particular, human keratin fibers such as hair.

[0357] The cosmetic process of the invention is, in particular, a process for improving the mechanical properties of smoothed keratin fibers, in particular, human keratin fibers such as hair.

[0358] The cosmetic process of the invention is, in particular, a process for improving the elasticity of smoothed keratin fibers, in particular, human keratin fibers such as hair.

[0359] The cosmetic process of the invention is, in particular, a process for improving the resistance to breakage of smoothed keratin fibers, in particular, human keratin fibers such as hair.

[0360] The process of the invention can be applied to wet or dry hair, preferably to wet hair.

[0361] The process according to the invention can be followed by a rinsing step. Preferably, the process according to the invention is followed by a rinsing step. The composition can preferably be left on the keratin fibers for a period of 1 to 30 minutes, and even better, for a period of 5 to 20 minutes before rinsing. The application time is preferably carried out at a high temperature, preferably between 25 and 40 °C. A person skilled in the art can use any known means, such as a hot plate.

[0362] The keratin fibres can then be dried or left to dry.

[0363] The process according to the invention may also include a step of shaping keratin fibers and, in particular, hair.

[0364] The process of the invention can be repeated several times. In particular, the process of treating smoothed keratin fibers such as hair, comprising the application of a cosmetic composition as defined above to the smoothed keratin fibers, in particular, to the smoothed keratin fibers, can be repeated several times.

[0365] Preferably, the process of the invention is repeated weekly. In particular, the process for treating smoothed keratin fibers such as hair includes applying a cosmetic composition as defined above to the smoothed keratin fibers, in particular, on smoothed keratin fibers, can be repeated weekly.

[0366] In a particular embodiment, the hair is straightened and the cosmetic composition as defined above is applied several times over time before the hair is straightened again.

[0367] The following example serves to illustrate the invention without, however, being limiting in nature. Examples

[0368] In the following example, and unless otherwise indicated, quantities are given as mass percentages of active material (ma) relative to the total weight of the composition. a) Compositions

[0369] The following compositions Al (invention) and B1 and B2 (comparative) were prepared from the ingredients indicated in Table 1 below (% by weight of active ingredient (AI)):

[0370] [Tables 1] Al (invention) B1 (comparative) B2 (comparative) Cocos nucifera (coconut) oil 5 - 5 HCl Cysteine ​​0.75 0.75 - Tocopherol 0.1 0.1 0.1 Cetearyl alcohol 5 5 5 Isononyl isononanoate 2.5 2.5 2.5 Behentrimonium chloride 5 5 5 Decetyl esters (and) cetyl esters 2.5 2.5 2.5 Bis-cetearyl-amodimethicone 1 1 1 Hydroxyethylcellulose 0.4 0.4 0.4 Perfume 1 1 1 Ethanolamine Qs pH9 Qs pH9 - Water Qs 100 Qs 100 Qs 100

[0371] pH of the formula = 9 b) Application of compositions

[0372] The routines, both for the control and compositions A, B1 and B2, are performed on African hair (curl type 7-8).

[0373] • Routine for straightened hair (control):

[0374] 1. Application of Relaxer (Dark&Lovely Superior Moisture Plus Kit (cream and activator) ) (4 g / g of hair) in which 3.70 g of relaxing cream are mixed with 0.36 g of activator

[0375] 2. Exposure time: 22 minutes at 31 °C

[0376] 3. Rinse off the relaxant after 22 minutes

[0377] 4. Application of 0.40 g of neutralizing shampoo (neutralizing shampoo) Dark & ​​Lovely Superior Moisture Plus) and rinse (x2)

[0378] 5. Air drying of the wick overnight

[0379] • Routine for composition A, B1 and B2:

[0380] 1. Application of Relaxer (Dark&Lovely Superior Moisture Plus Kit (cream and activator) ) (4 g / g of hair) in which 3.70 g of relaxing cream are mixed with 0.36 g of activator

[0381] 2. Exposure time: 22 minutes at 31 °C

[0382] 3. Rinse off the relaxant after 22 minutes

[0383] 4. Application of 0.40 g of neutralizing shampoo (neutralizing shampoo) Dark & ​​Lovely Superior Moisture Plus) and rinse (x2)

[0384] 5. Application of 1 g of composition A, B1 or B2 to a 1 g strand of hair wet

[0385] 6. Leave the treated hair on a heated plate at 31 degrees Celsius for 15 minutes

[0386] 7. Rinse off the treatment after 15 minutes

[0387] 8. Air drying of the wick overnight

[0388] - Repeat steps 5-8 5 times

[0389] c) Hair strengthening assessment protocol

[0390] To assess hair strengthening, the MTT assessment method was used. This assessment method provides an indication of the breaking strength and modulus of elasticity of the hair fiber. A higher breaking strength and / or modulus of elasticity means that the hair is stronger.

[0391] • Tensile strength and modulus of elasticity:

[0392] The tensile test is a unique method of mechanical evaluation of fibers which measures the tensile force during elongation until breakage of the hair.

[0393] The evaluation is carried out using a miniature tensile test (MTT675, Dia-stron) and can be performed under dry conditions (45% relative humidity) or In humid conditions (80% relative humidity), the method was performed in a dry environment. An extension rate of 12.5 mm / min and a gauge force of 0.5 g were used to elongate the capillary fiber to breakage. Cross-sectional measurements were taken using a fiber dimensional analysis system (FDAS, Dias-tron) and used to calculate the stress, which in turn allowed for the determination of additional properties such as the breaking stress and Young's modulus.

[0394] Breaking stress: a measure of the pressure that the particles of a material exert on each other and indicates the strength of a material; a higher breaking stress resonates with increased mechanical integrity when comparing the same material (i.e., hair) to itself, but with varying conditions such as treatment with a product.

[0395] Young's modulus: The characteristic stiffness of a material. The stiffness of the capillary fibers alone was measured with respect to a certain stress. Elasticity is the relationship with the applied stress to deform the sample within the elastic range. High elasticity indicates high resistance to deformation.

[0396] The results are presented in Table 2 below.

[0397] [Tables2] Sample Composition A Composition B1 Composition B2 Tensile strength (MPa) 98.1 131 135 106 Modulus of elasticity (MPa) 1794 2998 2436 1674

[0398] Straightened hair treated 5 times with composition A can withstand a higher force before breaking compared to the control (untreated straightened hair).

[0399] Straightened hair treated 5 times with composition A showed a higher modulus of elasticity than untreated straightened hair. Composition A improves the elasticity of straightened hair under dry conditions.

[0400] Furthermore, composition A (comprising a combination of cysteine ​​and coconut oil) offers better results than composition B1 (comprising only cysteine) and composition B2 (comprising only coconut oil).

[0401] Therefore, composition 1 (according to the invention) strengthens straightened hair.

[0402] • Cyclic fatigue test:

[0403] In this mechanical evaluation method, the hair fibers are subjected to repeated low-amplitude extension cycles until the fiber breaks or the maximum number of cycles set by the operator is reached. At the end of the fatigue test, the fiber lifetime is measured. This corresponds to the number of extension cycles the fiber withstood without breaking.

[0404] The mechanical tensile stress applied to the fiber can be a constant strain, a constant force, or a constant stress. For this analysis, cyclic fatigue tests were performed at a constant stress of 144 MPa using a Diastron CYC 801 cyclic fatigue testing machine. Cross-sectional area measurements were taken using a fiber dimensional analysis system (FDAS, Diastron) and used to arrive at the correct target stress.

[0405] The results are presented in Table 3 below.

[0406] [Tables3] Control Composition A Median cycles until rupture 145 597

[0407] We observe a statistically significant improvement in the mechanical properties of hair after 5 applications of composition A compared to untreated straightened hair (control).

Claims

Demands

1. A cosmetic process for treating smoothed keratin fibers, comprising the application to said keratin fibers of a cosmetic composition comprising: (i) 0.5 to 1% by weight, relative to the total weight of the composition, of cysteine ​​and / or one of its derivatives and salts, (ii) one or more fatty acid triglycerides selected from coconut oil, caprylic / capric acid triglycerides, palm kernel oil, babassu oil, cuphea oil and mixtures thereof in a total quantity of 2 to 10% by weight, relative to the total weight of the composition and (lii) optionally one or more additional reducing agents other than cysteine ​​and / or one of its derivatives (i) in a total quantity less than or equal to 1% by weight, relative to the total weight of the composition; the pH of said composition ranging from 7.5 to 10.

2. A method according to claim 1, wherein the weight ratio between the total amount of fatty acid triglycerides (ii) and the total amount of cysteine ​​and / or one of its derivatives (i) is greater than or equal to 1, preferably from 1 to 20, more particularly from 2 to 15.

3. A method according to any one of the preceding claims, wherein the composition further comprises one or more additional fatty substances other than fatty acid triglycerides (ii), preferably additional fatty substances are selected from fatty alcohols, fatty esters, triglyceride-type vegetable oils other than fatty acid triglycerides (ii), aminosilicones and mixtures thereof.

4. A method according to claim 3, wherein the total quantity of fatty substances ranges from 1 to 35% by weight, preferably from 5 to 25% by weight, relative to the total weight of the composition.

5. A method according to any one of claims 3 or 4, wherein the weight ratio between the total amount of the additional fatty substance(s), other than fatty acid triglycerides (ii) and the total amount of fatty acid triglycerides (ii) is greater than or equal to 1, preferably greater than or equal to 1.5, even better is greater than or equal to 2.

6. A method according to any one of the preceding claims, wherein the method is a method for strengthening smoothed keratin fibers.

7. A method according to any one of the preceding claims, wherein the method is a method for improving the mechanical properties of smoothed keratin fibers, in particular, the elasticity of smoothed keratin fibers and / or for improving the breaking strength of smoothed keratin fibers, preferably human hair.