Use of a composition comprising at least 80% by weight of vegetal oils and / or derivatives thereof as scalp protector before relaxer treatment

Abstract

The present invention relates to the use of a composition A comprising at least 80% by weight of vegetal oils and / or derivatives thereof as scalp protector before relaxer treatment. The invention also relates to a cosmetic treatment process for straightening keratin fibres using this composition A as a pre-treatment, and a relaxer kit.

Description

[0001] DESCRIPTION

[0002] TITLE : Use of a composition comprising at least 80% by weight of vegetal oils and / or derivatives thereof as scalp protector before relaxer treatment

[0003] The present invention relates to the use of a composition comprising at least 80% by weight of vegetal oils and / or derivatives thereof relative to the total weight of the composition, as scalp protector before relaxer treatment.

[0004] The invention also relates to a cosmetic treatment process for straightening keratin fibers using this composition as a pre-treatment. Another object of the invention is a relaxer kit comprising this composition, a relaxing composition and / or a neutralizing shampoo.

[0005] Many chemical treatments are available for changing the appearance of hair. In particular, chemical relaxer compositions are often used on curly hair. The chemical relaxer compositions make hair easier to straighten by chemically "relaxing" the natural curls. The active agent is often a strong alkali, although some formulations are based on ammonium thioglycolate instead. Hair relaxer compositions are applied to hair at a salon by a professional or in the home by the individual consumer. Hair fiber is a keratinous material, which is comprised of proteins (polypeptides). Many of the polypeptides in hair fibers are bonded together by disulfide bonds (-S-S-). A disulfide bond may be formed from the reaction of the two sulfhydryl groups (-SH), one on each of two cysteine residues, which results in the formation of a cystine residue. While there may be other types of bonds between the polypeptides in hair fibers, such as ionic salt bonds, the permanent curling and shape of the hair is essentially dependent on the disulfide bonds of cystine residues.

[0006] Chemical relaxing processes alter the aforementioned disulfide bonds between polypeptides in hair fibers to form lanthionine [S(CH2 CHNH2 COOH)2 ]. Thus, the term "lanthionizing" is often used when referring to the relaxing or straightening of keratin fibers by hydroxide ions. Hair fibers may be relaxed or straightened by disrupting the disulfide bonds of the hair fibers with an alkaline agent or with a reducing agent. The chemical disruption of disulfide bonds with an alkaline agent is generally combined with mechanical straightening of the hair, such as combing, and straight- ening generally occurs due to changes in the relative positions of opposing polypeptide chains within the hair fiber. This reaction is generally terminated by rinsing and / or application of a neutralizing composition.

[0007] The reaction with the alkaline agent is normally initiated by hydroxide ions. Hair relaxing processes proceed via the release of the hydroxide ions, which penetrate the hair fiber and transform cystine residues to lanthionine residues. Chemical relaxer compositions often contain varying proportions of strong water-soluble bases, such as sodium hydroxide (NaOH), or include slightly-soluble metal hydroxides, such as calcium hydroxide (Ca(OH)2), which can be converted in situ to soluble bases, such as guanidine hydroxide. Sodium hydroxide is extremely effective in straightening hair fibers but often causes a decrease in the strength of the hair fibers. Chemical relaxer compositions often damage the fiber quality to an extent that substantial breakage during combing of the hair may occur, notably when these compositions are applied to sensitized hair. Furthermore, the relaxed hair loses some of its desirable cosmetic properties such as shine, strength, smoothness. Last, hair relaxing treatments can be detrimental to the scalp and can cause irritation, redness, inflammation, or even bums if not applied properly or if the individual has a sensitivity to the chemicals used. Thus, consumers generally used anhydrous formula comprising a high content of petrochemicals such as petrolatum and / or mineral oil as scalp protector.

[0008] The formulation of environmentally-friendly cosmetic products, which are designed and developed considering environmental issues, is becoming a major goal in an effort to meet global challenges. It is therefore essential to propose more sustainable compositions, preparation processes and ingredients to address these environmental concerns.

[0009] In this context, it is important to develop new cosmetic compositions with a better carbon footprint, particularly by promoting the use of renewable raw materials and I or materials with a good index of naturalness and I or materials of natural origin and, more particularly, materials of plant origin while reducing the use of compounds of petrochemical origin.

[0010] However, replacing petrochemicals with mixture of vegetable substance derived from plants is challenging due to alkalinity and some stability issue; in particular, vegetable oils are unstable at high pH. Another concern is the saponification reaction where these waxes and oils of high ester content react with the active hydroxide ions and convert to acids and then salts, thus significantly reducing the alkalinity of the relaxer, thus possibly impacting its straightening performance.

[0011] There thus exists a real need to have available compositions with limited content of petrolatum jelly and mineral oil, which make it possible to protect the scalp from the aforementioned disagreements whilst preserving the straightening performances of the relaxing composition. In addition, the composition needs to be easy to apply specifically on the scalp without spreading on the length of the hair so as not to affect the efficacy of the hair relaxer during the subsequent relaxing step.

[0012] This goal may be achieved by using the composition according to the present invention as a pre-treatment before the relaxing step. More particularly, the aim is to provide a composition to be applied to the scalp that can undergo hydrolysis at a high pH to decrease locally the amount of hydroxides in contact with the scalp, and also form a hydrophobic barrier to prevent the actives from the relaxer from interacting with the scalp. Furthermore, the composition according to the invention needs to have a light paste texture that may transform in to an oily phase on application.

[0013] Thus, the subject of the invention is the use of a composition A comprising at least 80% by weight of vegetal oils and / or derivatives thereof as scalp protector before relaxer treatment. This composition, when applied on scalp, provides a protective barrier that uses both a physical and chemical mechanism to avoid scalp bum, irritation and itchiness during the hair relaxing process. It may also allow to retain moisture of the scalp barrier function. Furthermore, the application of the composition A as a pre-treatment before relaxer does not significantly alter the high performances of the relaxing composition in terms of the straightening of hair.

[0014] The invention also relates to a cosmetic treatment process for straightening keratin fibers using this composition A as a pre-treatment. The keratin fiber treatment process according to the invention thus comprises:

[0015] - a step (i) of applying to the scalp of a cosmetic composition A as defined below; then - a step (ii) of applying to the keratin fibers of a relaxing composition; then

[0016] - a step (iii) of rinsing with water, and / or a washing step.

[0017] For sake of clarity, the cosmetic composition A is not rinsed before the application of the relaxing composition to the keratin fibers.

[0018] The step (ii) may optionally be followed by a leave-on time, for example of from 5 to 60 minutes, notably from 10 to 40 minutes, preferably from 10 to 30 minutes, better from 15 to 25 minutes. This step is followed by a rinsing step, for example a step of rinsing with water, and / or a washing step, for example a step of washing with a neutralizing shampoo. Preferably, step (ii) is followed by a rinsing step and a washing step. Even more preferably, step (ii) is followed by a rinsing step and a washing step with a neutralizing shampoo.

[0019] Steps (i) and (ii) are performed in succession or sequentially, meaning that step (ii) is subsequent to the step (i); step (i) is thus referred to as a pre-treatment step.

[0020] Last, the invention also relates to a relaxer kit comprising:

[0021] (i) a first compartment containing a composition A comprising at least 80% by weight of vegetal oils and / or derivatives thereof, more preferably one or more vegetal oils and caprylic / capric triglycerides, better a mixture of coconut oil, castor oil, sunflower seed oil and caprylic / capric triglyceride; and

[0022] (ii) a second compartment containing a relaxing composition, more preferably a a “no-mix” relaxer, more preferably a composition C comprising: a) at least one alkali metal carbonate; b) calcium hydroxide; c) sodium or potassium metasilicate; and d) one or more fatty substance(s); and / or

[0023] (iii) a third compartment containing a neutralizing shampoo.

[0024] In the text hereinbelow, unless otherwise indicated, the limits of a range of values are included in that range, notably in the expressions “between” and “ranging from ... to ...”.

[0025] Moreover, the expression “at least one” used in the present description is equivalent to the expression “one or more” and may be replaced therewith. The term “clarifying shampoo” corresponds to a hair care product that has the purpose of removing of build up, eg. excess of sebum, impurities, and residues of hair products that spread on the scalp and lengths. It contains a high concentration of surfactants.

[0026] The term “neutralizing shampoo” corresponds to a hair care product that is designed to balance the pH levels of the hair and scalp after undergoing chemical treatments such as hair coloring, perming, straightening or relaxing. For instance, it may have the purpose of indicating the removal of the relaxer from the hair through the use of a colour indicator dye found in the shampoo. Neutralizing shampoos have a lower concentration of surfactants compared to clarifying shampoos.

[0027] AZ Composition A

[0028] The composition A used as scalp protector according to the present invention comprises at least 80% by weight of vegetal oils and / or derivatives thereof relative to the total weight of the composition.

[0029] Preferably, the composition A used according to the present invention does not comprise mineral oil, nor petrolatum jelly.

[0030] Vegetal oils and / or derivatives thereof

[0031] The term "oil" is understood to mean a fatty substance which is liquid at ambient temperature (25°C) and atmospheric pressure (760 mmHg, i.e. 105 Pa). The oil can be volatile or nonvolatile.

[0032] Preferably, the vegetal oils and / or derivatives thereof used in the composition A of the invention are non-volatile.

[0033] Vegetal oils can be natural or further modified via chemical reactions such as hydrogenation to yield some derivatives of vegetal oils.

[0034] Vegetal oils (or oils of vegetal origin) comprise mixtures of triglycerides of vegetal origin, i.e., esters of glycerol and fatty acids, or mixtures of esters of fatty alcohol and fatty acids (such as jojoba oil). Among the vegetal oils that may be used in the compositions A according to the invention, mention may be made of olive oil, avocado oil, argan oil; camellia oil, cottonseed oil, rice bran oil, corn germ oil, wheat germ oil, passionflower oil, soybean oil, peanut oil, copra oil, pumpkin seed oil, sesame oil, babassu oil, coconut oil, rapeseed oil, sweet almond oil, walnut oil, evening primrose oil, flaxseed oil, castor oil, safflower oil, sunflower seed oil, coffee oil, borage oil, apricot kernel oil, bambara pea oil, mango oil, rose oil, kiwi seed oil, sea buckthorn pulp oil, bilberry seed oil, poppy seed oil, orange seed oil, palm oil, vernonia oil, marjoram oil, baobab oil, ximenia oil, pracaxi oil, alfalfa oil, cucumber oil, millet oil, barley oil, quinoa oil, rye oil, candlenut oil, musk rose oil, maize oil, marrow oil, grapeseed oil, hazelnut oil, macadamia oil, arara oil, jojoba oil, liquid butters at 25°C such as shea butter, as well as mixtures thereof.

[0035] Derivatives of vegetal oils such as hydrogenated vegetal oil can also be used in the composition A according to the invention. Specific mixtures of triglycerides extracted from the aforementioned vegetal oils can be mentioned. They are preferably chosen from liquid fatty acid triglycerides including from 6 to 30 carbon atoms, for instance heptanoic or octanoic acid triglycerides. Caprylic / capric triglycerides derived from coconut oil are particularly preferred, for instance those sold by the company Stearinerie Dubois or those sold under the names Miglyol® 810, 812 and 818 by the company Dynamit Nobel.

[0036] In a preferred embodiment, the composition A used according to the invention comprises one or more vegetal oils and derivatives thereof, more particularly one or more vegetal oils and caprylic / capric triglycerides, better a mixture of coconut oil, castor oil, sunflower seed oil and caprylic / capric triglyceride.

[0037] The total content of vegetal oil(s) and / or derivatives thereof in the composition A used according to the invention preferably ranges from 80 to 95% by weight, more preferably 85 to 95% by weight, even more preferably from 90 to 95% by weight, relative to the total weight of the composition.

[0038] The total content of vegetal oil(s) in the composition A used according to the invention preferably ranges from 70 to 85% by weight, more preferably 75 to 85% by weight, even more preferably from 80 to 85% by weight, relative to the total weight of the composition. The total content of derivatives of vegetal oils, particularly liquid fatty acid triglycerides, in the composition A used according to the invention preferably ranges from 5 to 15% by weight, more preferably from 7 to 12% by weight, relative to the total weight of the composition.

[0039] Advantageously, the total content of caprylic / capric triglycerides in the composition A used according to the invention preferably ranges from 5 to 15% by weight, more preferably from 7 to 12% by weight, relative to the total weight of the composition.

[0040] Waxes

[0041] The composition A used as scalp protector according to the present invention can optionally comprise one or more waxes.

[0042] For the purposes of the present invention, a wax is a lipophilic compound, which is solid at 25°C and atmospheric pressure, with a reversible solid / liquid change of state, having a melting point greater than or equal to 45°C. The melting point may be up to 200°C, The waxes have in the solid state anisotropic crystal organization. In general, the size of the wax crystals is such that the crystals diffract and / or scatter light, giving the composition that comprises them a more or less opaque cloudy appearance. By bringing the wax to its melting point, it is possible to make it miscible with oils and to form a microscopically homogeneous mixture, but on returning the temperature of the mixture to room temperature, recrystallization of the wax, which is microscopically and macroscopically detectable (opalescence), is obtained.

[0043] The melting point of the waxes preferably ranges from 50°C to 150°C, more particularly from 60°C to 110°C.

[0044] In particular, the waxes that are suitable for use in the invention may be chosen from waxes of animal, plant or mineral origin, nonsilicone synthetic waxes, and mixtures thereof.

[0045] Mention may notably be made of hydrocarbon waxes, for instance beeswax or modified beeswaxes (cera bellina), lanolin wax and lanolin derivatives, spermaceti; cork fibre or sugarcane waxes, olive tree wax, rice bran waxes, carnauba waxes, candelilla waxes, ouricury wax, esparto grass wax, berry wax, shellac wax, Japan wax and sumac wax, absolute waxes of flowers; montan wax, orange wax, lemon wax, microcrystalline waxes, paraffins, petroleum jelly, lignite and ozokerite; polyethylene waxes, the waxes obtained by Fischer-Tropsch synthesis and waxy copolymers, and also esters thereof.

[0046] Mention may also be made of C2 to C60 microcrystalline waxes, such as Microwax HW.

[0047] Mention may also be made of the polyethylene waxes sold under the reference Permalen 50-L Polyethylene or under the reference Performa SW 100 Synthetic Wax by the company Nucera Solutions.

[0048] Mention may also be made of the waxes obtained by catalytic hydrogenation of animal or plant oils containing linear or branched C8 to C32 fatty chains. Among these waxes, mention may notably be made of isomerized jojoba oil such as trans-isom- erized partially hydrogenated jojoba oil, notably the product manufactured or sold by the company Desert Whale under the commercial reference Iso-Jojoba-50®, hydrogenated sunflower oil, hydrogenated castor oil, hydrogenated coconut kernel oil, hydrogenated lanolin oil and bis(1 , 1 ,1 -trimethylolpropane) tetrastearate, notably the product sold under the name Hest 2T-4S® by the company Heterene.

[0049] The waxes obtained by hydrogenation of castor oil esterified with cetyl alcohol, such as those sold under the names Phytowax Castor 16L64® and 22L73® by the company Sophim, may also be used.

[0050] A wax that may be also used is a C20 to C40 alkyl (hydroxystearyloxy)stearate (the alkyl group comprising from 20 to 40 carbon atoms), alone or as a mixture. Such a wax is notably sold under the names Kester Wax K 82 P®, Hydroxypolyester K 82 P® and Kester Wax K 80 P® by the company Koster Keunen.

[0051] It is also possible to use microwaxes in the compositions of the invention; mention may notably be made of carnauba microwaxes, such as the product sold under the name MicroCare 350® by the company Micro Powders, synthetic-wax microwaxes, such as the product sold under the name MicroEase 114S® by the company Micro Powders, microwaxes constituted of a mixture of carnauba wax and polyethylene wax, such as the products sold under the names Micro Care 300® and 310® by the company Micro Powders, microwaxes constituted of a mixture of carnauba wax and of synthetic wax, such as the product sold under the name Micro Care 325® by the company Micro Powders, polyethylene microwaxes, such as the products sold under the names Micropoly 200®, 220®, 220L® and 250S® by the company Micro Powders, and polytetrafluoroethylene microwaxes, such as the products sold under the names Microslip 519® and 519 L® by the company Micro Powders. The wax(es) can be chosen from mineral waxes, for instance paraffin, petroleum jelly, lignite or ozokerite wax; plant waxes, for instance cork fibre or sugar cane waxes, olive tree wax, rice bran waxes, hydrogenated jojoba wax, ouricury wax, carnauba waxes, candelilla waxes, esparto grass wax, or absolute waxes of flowers, such as the essential wax of blackcurrant blossom sold by the company Bertin (France); waxes of animal origin, for instance beeswaxes or modified beeswaxes (cera bellina), spermaceti, lanolin wax and lanolin derivatives; polyethylene waxes; microcrystalline waxes; and mixtures thereof.

[0052] Preferentially, the wax(es) are chosen from plant waxes, particularly carnauba wax, candelilla wax and mixtures thereof, more preferably candelilla wax.

[0053] Preferably, the composition A used according to the invention comprises one or more waxes, more preferably chosen from plant waxes, particularly carnauba wax, candelilla wax and mixtures thereof, even better candelilla wax.

[0054] When it (they) is (are) present, the total content of the wax(es) preferably ranges from 1 % to 20% by weight, more preferably from 2% to 18% by weight and better still from 4% to 10% by weight, relative to the total weight of the composition.

[0055] When it (they) is (are) present, the total content of plant waxes, particularly carnauba wax, candelilla wax and mixtures thereof, preferably ranges from 1 % to 20% by weight, more preferentially from 2% to 18% by weight and better still from 4% to 10% by weight, relative to the total weight of the composition.

[0056] When it is present, the total content of candelilla wax ranges from 1 % to 20% by weight, more preferentially from 2% to 18% by weight and better still from 4% to 10% by weight, relative to the total weight of the composition.

[0057] Ceramide

[0058] The composition A used as scalp protector according to the present invention can optionally comprise one or more ceramides or ceramides analogues.

[0059] Ceramides or ceramide analogues, such as glycoceramides, that can be used in the compositions A according to the invention are known; in particular, ceramides of classes I, II, III, and V according to the DAWNING classification can be mentioned.

[0060] The ceramides or their analogues that can be used preferably correspond to the following formula: in which:

[0061] R1 represents a linear or branched, saturated or unsaturated alkyl group derived from C14-C30 fatty acids, this group may be substituted by a hydroxyl group in the alpha position, or a hydroxyl roup in the omega position esterified by a saturated or unsaturated C16-C30 fatty acid;

[0062] R2 represents a hydrogen atom, a (glycosyl)n group, a (galactosyl)m group, or a sulfogalactosyl group, where n is an integer ranging from 1 to 4 and m is an integer ranging from 1 to 8;

[0063] R3 represents a C15-C26 hydrocarbon group, saturated or unsaturated in the alpha position, this group may be substituted by one or more C1 -C14 alkyl groups; it being understood that in the case of natural ceramides or glycoceramides, R3 may also represent a C15-C26 alpha-hydroxyalkyl group, the hydroxyl group optionally being esterified by a C16-C30 alpha-hydroxy acid. Preferably, ceramides are used for which R1 represents a saturated or unsaturated alkyl group derived from C14-C30 fatty acids; R2 represents a galactosyl or sulfogalactosyl group; and R3 represents a -CH=CH-(CH2)12-CH3 group. The more particularly preferred ceramides are the compounds for which R1 represents a saturated or unsaturated alkyl derived from C16-C22 fatty acids; R2 represents a hydrogen atom; and R3 represents a saturated or unsaturated linear C15 group. Compounds for which R1 represents a saturated or unsaturated alkyl radical derived from C12-C22 fatty acids may also be used; R2 represents a galactosyl or sulfogalactosyl radical; and R3 represents a saturated or unsaturated C12-C22 hydrocarbon radical, and preferably a -CH=CH- (CH2)12-CH3 group. As particularly preferred compounds, mention may also be made of 2-N-linoleoylamino-octadecane-1 ,3-diol; 2-N-oleoylamino-octadecane-1 ,3- diol; 2-N-palmitoylamino-octadecane-1 ,3-diol; 2-N-stearoylamino-octadecane-1 ,3- diol; 2-N-behenoylamino-octadecane-1 ,3-diol; 2-N-[2-hydroxy-palmitoyl]-amino-oc- tadecane-1 ,3-diol; 2-N-stearoylamino-octadecane-1 ,3,4-triol and in particular N- stearoylphytosphingosine; 2-N-palmitoylamino-hexadecane-1 ,3-diol, N-linoleoyldi- hydrosphingosine, N-oleoyldihydrosphingosine, N-palmitoyldihydrosphingosine, N- stearoyldihydrosphingosine, and N-behenoyldihydrosphingosine, N-docosanoyl N- methyl-D-glucamine, N-(2-hydroxyethyl)-N-(3-cetyloxy-2-hydroxypropyl) cetylamide and bis-(N-hydroxyethyl-N-cetyl) malonamide; and mixtures thereof.

[0064] Antioxidant agent

[0065] The composition A used as scalp protector according to the present invention can optionally comprise one or more antioxidant agents chosen from tocopherol, its derivatives, salts thereof, and their mixtures.

[0066] "Antioxidant agent," as understood in the present invention, refers to an agent that slows or prevents the oxidation of other chemical substances upon contact.

[0067] Tocopherol preferably corresponds to a-tocopherol, or vitamin E. It has the following structure of formula (IV):

[0068] "Tocopherol derivative" preferably refers to tocopherol esters and ethers, tocotri- enols and their optical and geometric isomers, preferably esters of C1-C24 carboxylic acid and ethers of C1 -C24 alcohol, more preferably esters of C1 -C24 carboxylic acid.

[0069] Among the tocopherol esters of C1 -C24 carboxylic acid that may be used in the compositions A, mention may be made of tocopherol esters of (C1-C22)alkylcar- boxylic acid, better (C1-C4)alkylcarboxylic acid; (C2-C22)alkenyl carboxylic acid; (hetero)arylcarboxylic acid such as pyridinecarboxylic acids. More preferably, esters of tocopherol and carboxylic acids are chosen from tocopheryl acetate, to- copheryl palmitate, tocopheryl linoleate, or tocopheryl nicotinate, or mixtures thereof. An example is the product DL Alpha Tocopheryl Acetate® marketed by the company EISAI. Among the tocopherol ethers that may be used in the compositions A, mention may be made of ethers derived from (C1 -C22)alkanols or (C2-C22)alkenols.

[0070] Advantageously, the antioxidant agent(s) is / are chosen from tocopherol and its C1 -C4 acid esters, particularly tocopherol, tocopheryl acetate and mixtures thereof, more preferably tocopheryl acetate.

[0071] Advantageously, the total content of tocopherol and / or its esters of C1 -C24 carboxylic acid, preferably its esters of C1 -C4 alkylcarboxylic acid, ranges from 0.1 to 5% by weight, preferably from 0.2 to 3% by weight, better from 0.3 to 1 % by weight, relative to the total weight of the composition.

[0072] Advantageously, the total content of tocopheryl acetate ranges from 0.1 to 5% by weight, preferably from 0.2 to 3% by weight, better from 0.3 to 1 % by weight, relative to the total weight of the composition.

[0073] According to a preferred embodiment, the composition A used as scalp protector according to the invention comprises: a) at least 80% by weight of vegetal oils and / or derivatives thereof relative to the total weight of the composition, preferably one or more vegetal oils and caprylic / capric triglycerides, better a mixture of coconut oil, castor oil, sunflower seed oil and caprylic / capric triglyceride, more preferably in a total amount of 80 to 95% by weight, better from 85 to 95% by weight, better still from 90 to 95% by weight, relative to the total weight of the composition.

[0074] In another preferred embodiment, the composition A further comprises: b) one or more waxes, preferably chosen from plant waxes, better carnauba wax, candelilla wax and mixtures thereof, even better candelilla wax, more preferably in a total amount of 1 % to 20% by weight, better from 2% to 18% by weight, better still from 4% to 10% by weight, relative to the total weight of the composition; and / or c) one or more ceramides or ceramides analogues such as glycoceramides, preferably chosen from the compounds having the following formula: wherein Ri , R2 and R3 are as defined previously. d) one or more antioxidant agents chosen from tocopherol, its derivatives, salts thereof and their mixtures, preferably tocopherol and / or its esters of C1 -C24 carboxylic acid, more preferably its esters of C1 -C4 alkylcarboxylic acid, better tocopherol acetate, more preferably in a total amount of 0.1 to 5% by weight, better from 0.2 to 3% by weight, better still from 0.3 to 1 % by weight, relative to the total weight of the composition.

[0075] Bl Keratin fiber relaxer used in the step (ii)

[0076] The process according to the invention comprises a step (ii) known as relaxing step, comprising the application to the keratin fibers of a relaxing composition.

[0077] Hair relaxers generally fall into two categories: mix and no-mix. "Mix" relaxers generally require a two-component system of a cream base and an activator, which are combined prior to use. Darkwaet al.; U.S. Patent No. 5,679,327, which issued October 21 , 1997, describes a highly alkaline hair straightening emulsion of this variety. The emulsion described employs a combination of a strong nitrogenous organic base and an alkali metal hydroxide in the presence of an alkaline earth metal cation. Such combination is effective for achieving permanent straightening of hair with a treatment time not more than about 30 minutes. By way of example, chemical relaxer compositions may include slightly-soluble metal hydroxides, such as calcium hydroxide (Ca(OH)2), which can be converted in situ to soluble bases, such as guanidine hydroxide.

[0078] In a certain embodiment, "mix" relaxer may be prepared and applied according to the following steps:

[0079] (I) one step of extemporaneous mixing of at least: a. a composition B1 comprising guanidine carbonate, and b. a composition B2 comprising at least one hydroxide chosen from alkali metal hydroxides, alkaline-earth metal hydroxides and mixtures thereof, preferably calcium hydroxide, and wherein said composition B1 and / or said composition B2 comprise at least one (C6- C16) fatty acid triglyceride, preferably composition B1 comprises at least one (C6- C16) fatty acid triglyceride; and then

[0080] (II) one step of applying onto said keratin fibers the composition (M), resulting from the extemporaneous mixing of composition B1 and composition B2 according to step (I).

[0081] Exemplary « mix » relaxers that can be used in the process according to the invention are described in FR3145092.

[0082] So-called "no-mix" relaxers on the other hand are ready to use. They generally are in the form of a liquid, cream, gel, paste or emulsion which can be directly applied to a subject's hair without first, as the term implies, mixing of two or more separate components. Some hair relaxers rely on strong organic and / or inorganic bases such as sodium hydroxide (also referred to as lye) to break the disulfide bonds found in hair's structure. In the concentrations used, these strong bases generally exist at a pH of greater than 13.2. Other strong inorganic bases have been used in place of sodium hydroxide. One of the most popular is lithium hydroxide. Lithium hydroxide, at appropriate concentrations, results in a lower pH and therefore is more comfortable and can be applied for longer periods of time.

[0083] In a certain embodiment, the "no-mix" relaxer is a composition C comprising: a) at least one alkali metal carbonate; b) calcium hydroxide; c) sodium or potassium metasilicate; and d) one or more fatty substance(s).

[0084] In a preferred embodiment, the keratin fiber relaxer used in step (i) of the process according to the invention is a "no-mix" relaxer, preferably a composition C comprising: a) at least one alkali metal carbonate; b) calcium hydroxide; c) sodium or potassium metasilicate; and d) one or more fatty substance(s).

[0085] Preferably, the fatty substances contained in the composition C include optionally up to 30% by weight of mineral oil and / or petrolatum jelly relative to the total weight of the composition.

[0086] In a preferred embodiment, the total amount of mineral oil and / or petrolatum jelly is below 30% by weight, preferably below 20% by weight, more preferably below 10% by weight, better below 5% by weight, better still below 1 % by weight.

[0087] Preferably, the fatty substance(s) does (do) not include mineral oil, nor petrolatum jelly in the composition C according to the invention.

[0088] According to a preferred embodiment, the amount of calcium hydroxide b) is of at least 1 .4% by weight, relative to the total weight of the composition. Preferably, the total amount of calcium hydroxide b) ranges from 1 .4 to 30% by weight, more preferably from 1 .4 to 20% by weight, even more preferably from 1 .4 to 15% by weight, better from 1 .4 to 10% by weight, better still from 1 .4 to 5% by weight, even better still from 1 .4 to 3% by weight, relative to the total weight of the composition.

[0089] According to a preferred embodiment, the total amount of alkali metal carbonate(s) a) and sodium or potassium metasilicate c) is of at least 2.6% by weight, relative to the total weight of the composition. In other words, the sum of the amount of alkali metal carbonate(s) a) and of the amount of sodium or potassium metasilicate c) is of at least 2.6% by weight, relative to the total weight of the composition. Preferably, the total amount of alkali metal carbonate(s) a) and sodium or potassium metasilicate c) ranges from 2.6 to 30% by weight, preferably from 2.6 to 20% by weight, more preferably from 2.6 to 15% by weight, better from 2.6 to 10% by weight, better still from 2.6 to 5% by weight, even better still from 3 to 4.5% by weight, relative to the total weight of the composition.

[0090] Advantageously, the total amount of alkali metal carbonate(s) a) ranges from 0.1 to 30% by weight, preferably from 0.5 to 20% by weight, more preferably from 0.8 to 15% by weight, better from 0.8 to 10% by weight, better still from 1 to 5% by weight, even better still from 2 to 4% by weight, relative to the total weight of the composition.

[0091] According to a preferred embodiment, the total amount of sodium or potassium metasilicate c) ranges from 0.1 to 30% by weight, preferably from 0.5 to 20% by weight, more preferably from 0.8 to 15% by weight, better from 0.8 to 10% by weight, better still from 0.8 to 5% by weight, relative to the total weight of the composition. According to one embodiment, the at least one alkali metal carbonate a) and calcium hydroxide b) can be present at a weight ratio (sodium carbonate a) I calcium hydroxide b)) ranging from 0.003 to 25, preferably from 0.01 to 20, more preferably from 0.1 to 10, better from 0.2 to 5, better still from 0.5 to 2, even better still from 1 to 1.5.

[0092] Advantageously, sodium or potassium metasilicate c) and calcium hydroxide b) can be present at a weight ratio (sodium or potassium metasilicate c) I calcium hydroxide b)) ranging from 0.003 to 25, preferably from 0.01 to 20, more preferably from 0.1 to 10, better from 0.2 to 5, better still from 0.5 to 1 .5.

[0093] According to one embodiment, the at least one alkali metal carbonate a) and sodium or potassium metasilicate c) can be present at a weight ratio (alkali metal carbonate a) I sodium or potassium metasilicate c)) ranging from 0.003 to 25, preferably from 0.01 to 20, more preferably from 0.1 to 10, better from 0.2 to 5, better still from 0.4 to 3, even better still from 1 to 2.5.

[0094] Preferably, the alkali metal carbonate a) is chosen from sodium carbonate, potassium carbonate, and mixture thereof.

[0095] More preferably, the alkali metal carbonate a) is sodium carbonate.

[0096] Preferably, sodium or potassium metasilicate c) is sodium metasilicate.

[0097] According to one preferred embodiment, the composition C according to the invention does not comprise lithium hydroxide.

[0098] According to one preferred embodiment, the composition C according to the invention does not comprise sodium hydroxide.

[0099] According to a particularly preferred embodiment, the composition C according to the invention does not comprise lithium hydroxide nor sodium hydroxide.

[0100] Preferably, the composition C according to the invention comprises some fatty substances selected from solid fatty substances, liquid fatty substances, and mixtures thereof, wherein:

[0101] (i) the solid fatty substances are preferably chosen from solid fatty acids, solid fatty alcohols, solid esters of fatty acids and / or of fatty alcohols, waxes, butters, ceramides, solid monoglycerides, diglycerides or triglycerides, and mixtures thereof, more preferably from solid fatty alcohols, butters, ceramides and mixtures thereof, even more preferably from solid fatty alcohols and butters, better still from cetearyl alcohol, cetyl alcohol, stearyl alcohol, shea butter (Butyrospermum parkii), and mixtures thereof;

[0102] (ii) the liquid fatty substances are preferably chosen from liquid hydrocarbons, non- silicone oils of animal origin, oils of triglyceride type of plant or synthetic origin, fluoro oils, liquid fatty alcohols, liquid esters of fatty acid and / or fatty alcohol different from triglycerides, and mixtures thereof, preferably chosen from liquid hydrocarbons, liquid fatty alcohols, and mixtures thereof, more preferably C15-C19 alkanes, squalane, octyldodecanol and mixture thereof, even more preferably C15-C19 alkanes and octyldodecanol.

[0103] In a preferred embodiment, the solid fatty substances do not include solid fatty acids, nor solid esters of fatty acid and / or fatty alcohol different from triglycerides and / or the liquid fatty substances do not include liquid esters of fatty acid and / or fatty alcohol different from triglycerides.

[0104] The total amount of the solid fatty substance(s) in the composition C ranges preferably from 1 to 80% by weight, preferably from 5 to 60% by weight, more preferably from 10 to 30% by weight, better from 10 to 20% by weight, relative to the total weight of the composition.

[0105] Preferably, the composition C according to the invention comprises at least one liquid fatty alcohol, preferably octyldodecanol, more preferably in an amount ranging from 0.1 to 10% by weight, preferably 0.2 to 5% by weight, more preferably 0.3 to 4% by weight, relative to the total weight of the composition.

[0106] The total amount of the liquid fatty substance(s) ranges preferably from 1 to 80% by weight, preferably from 5 to 60% by weight, more preferably from 10 to 40% by weight, better from 20 to 30% by weight, relative to the total weight of the composition.

[0107] In a preferred embodiment, the composition C comprises at least one solid fatty substance and at least one liquid fatty substance, preferably selected from liquid fatty alcohol, liquid hydrocarbon and mixtures thereof, wherein the (solid fatty alcohol I liquid fatty substance) weight ratio is higher than or equal to 0.2, preferably ranging from 0.2 to 2, more preferably from 0.3 to 1 .

[0108] In a particular embodiment, the composition C according to the invention further comprises one or more surfactants, wherein said surfactant(s) is (are) preferably chosen from nonionic surfactants, amphoteric or zwitterionic surfactants, cationic surfactants, and mixtures thereof, more preferably chosen from steareth-20, stea- reth-21 , cocam idopropyl betaine, behentrimonium methosulfate and mixtures thereof.

[0109] When they are present, the total amount of said surfactant(s) range(s) preferably from 0.1 to 20% by weight, more preferably from 0.5 to 10% by weight, even more preferably from 0.5 to 10%, better from 1 to 5% by weight, relative to the total weight of the composition.

[0110] Preferably, the composition C comprises cationic surfactants, preferably behentri- monium methosulfate, more preferably in an amount ranging from 0.01 to 10% by weight, preferably 0.1 to 5% by weight, more preferably 0.4 to 2% by weight, better 1 .5 to 2% by weight, relative to the total weight of the composition.

[0111] In another embodiment, the composition C according to the invention further comprises one or more polyols, wherein said polyol(s) preferably comprise two -OH groups (diols) and 2 to 6 carbon atoms, and are linear and saturated, preferably selected from propylene glycol (propane-1 ,2-diol), propane-1 ,3-diol, butylene glycol (butane-1 ,3-diol), butane-2,3-diol, hexylene glycol, pentylene glycol (pentane-1 ,2- diol), and mixtures thereof, more preferably selected from propylene glycol, hexylene glycol, butylene glycol or mixtures thereof, even more preferentially propylene glycol.

[0112] When they are present, the total amount of said polyol(s) range(s) preferably from 0.1 % to 20% by weight, better still from 0.5% to 10% by weight, or even from 1 % to 5% by weight, preferentially from 1 % to 3% by weight, relative to the total weight of the composition.

[0113] The composition C can comprise water in an amount ranging from 10 to 70% by weight, preferably from 20 to 60% by weight, more preferably from 30 to 60% by weight, relative to the total weight of the composition.

[0114] The pH of the composition C may range from 10 to 14, preferably from 11 to 14, more preferably from 12 to 13,6.

[0115] The following examples serve to illustrate the invention without, however, exhibiting a limiting nature.

[0116] Examples

[0117] In the examples that follow and unless otherwise indicated, the amounts are given as weight percentages of active material (AM) relative to the total weight of the composition.

[0118] Example 1 The compositions A1 , A2, A3 and A4 according to the invention were prepared from the ingredients indicated in Table 1 below:

[0119] [Table 1 ]

[0120] « sq » means « sufficient quantity ». The compositions according to the invention showed good performances in terms of scalp protection before applying a relaxer. Example 2

[0121] The following hair relaxing composition (hair relaxer) were used: [Table 2] Example 3: Scalp protection during relaxing treatment The composition A1 according to the invention was used as a pre-treatment before applying the commercial relaxer Dark&Lovely Precise Diamond (sodium based relaxer). The scalp comfort experienced by the users was evaluated when using the pre-treatment versus when they do not.

[0122] Protocol:

[0123] The composition A1 was applied on the scalp of a half head, whilst the other half head will not receive any pre-treatment. The quantity per half head was between 2.5 g and 5 g depending on the size of models scalp and the sensitivity of the scalp. For clarity, only the scalp and the root of the associated hair will be in contact with the composition A1 , avoiding any contact with the length of the hair to be relaxed.

[0124] Then, the commercial relaxer Dark&Lovely Precise Diamond was applied on fine- to-medium or medium-to-coarse hair, curl type 7+ with an applicator brush and then twice smoothed with the back of a tail comb. A quantity of ~120 g of composition was used per half head. The half head was then left for up to 22 minutes.

[0125] The half head was then rinsed under tap water. A neutralizing shampoo was then applied to the hair. A quantity of 10 g of shampoo was used per half head.

[0126] Each half head was then finally blow dried.

[0127] Scalp comfort assessment as reported by the user

[0128] The users reported more significant scalp discomfort such as dryness, tightness and itching during the relaxing process without the application of the scalp protector.

[0129] In conclusion, the scalp protector according to the invention provides a protective barrier to avoid scalp burn, irritation and itchiness during the hair relaxing process, whilst preserving the straightening performances of the relaxing composition. Similar observations and results were obtained during a relaxing treatment process comprising the application of composition A1 as scalp protector, then followed by the application of the hair relaxer of formula C4.

[0130] Although a slight impact on straightness, particularly on coarse hair, was observed when using the scalp protector according to the invention, the resulting hair felt slightly smoother in both wet and dry stages.

[0131] Besides, it was observed that upon application, composition A1 changed texture - transitioning from its original viscous form to an oil-like consistency. This indicates an interesting transformation that aids with application and scalp coverage. Example 4: Moizturinq

[0132] Protocol

[0133] The composition A1 was applied on the scalp of a half head, whilst the other half head will not receive any pre-treatment. The quantity per half head was between 2.5 g and 5 g depending on the size of models scalp and the sensitivity of the scalp. For clarity, only the scalp and the roots of the associated hair will be in contact with the composition A1 , avoiding any contact with the length of the hair to be relaxed.

[0134] Then, the commercial relaxer Dark&Lovely Precise Diamond was applied on fine- to-medium or medium-to-coarse hair, curl type 7+ with an applicator brush and then twice smoothed with the back of a tail comb. A quantity of ~120 g of composition was used per half head. The half head was then left for up to 22 minutes.

[0135] The half head was then rinsed under tap water. A neutralizing shampoo was then applied to the hair. A quantity of 10 g of shampoo was used per half head.

[0136] Each half head was then finally blow dried.

[0137] Instrumental method and touch points:

[0138] This study was done using a nanotewameter that allows to measure the Transepidermal Water Loss (TEWL) in g / h / m2on small, or difficult to reach sites such as scalp. TEWL was measured at different time (TO, Timm and T24) on the left and right side of the treated head.

[0139] TO: Before relaxer application

[0140] Timm: Post relaxer application

[0141] T24: 24-hour recall

[0142] [Table 3]

[0143] The baseline TEWL is of approximately 27 g / m2 / h in the centre part of the head before relaxer application. This TO value was taken as a representation of the overall scalp. An immediate increase up to 32 g / m2 / h is observed after the relaxer application. Then, the TEWL decreased decreases to approximately 24 g / m2 / h after 24 hours in this centre part of head.

[0144] The side of the head with scalp protector demonstrated lower TEWL at approximately 29 g / m2 / h after the application of the relaxer, whilst higher TEWL at approximately 39 g / m2 / h were measured on the side of the head without scalp protector.

[0145] On day 2 (T24), TEWL further reduced to approximately 25 g / m2 / h on the side of the head with scalp protector, whilst TEWL at approximately 29 g / m2 / h was measured.

[0146] In conclusion, the scalp protector retains moisture of the scalp barrier function and reduces scalp irritation as evidenced by lower TEWL values measured on the side of the head with scalp protector after relaxer application. The application of composition A1 according to the invention afforded a barrier protection to the scalp against the relaxing composition and allowed a fast recovery in terms of moisturizing properties. Globally, scalp irritation and discomfort are reduced during and after treatment.

[0147] The device used to conduct this study is an auto-titrator and the parameter measured is alkalinity - the concentration of hydroxide ions. More specifically, an auto-titrator is an automated instrument that performs titrations, a chemical technique used to determine the concentration of a substance. It precisely delivers a titrant (solution of known concentration) to a sample and detects the reaction endpoint, allowing for accurate calculation of the unknown concentration. In the context of alkalinity, an auto-titrator can measure the concentration of hydroxide ions (OH-) in a solution, providing a quantitative assessment of its alkalinity. The scalp protector incorporated into a relaxer formulation is hypothesized to reduce the alkalinity reading (concentration on OH ions) compared to that of the relaxer on its own.

[0148] Methodology for Scalp Protector Chemical Function Measure i) Mix 5 g of hair relaxer of formula C3 or C4 and 0.8 g of scalp protector of formula A1. ii) Allow mixture to stand for 30 minutes. iii) Add 60 ml of hot water to the mixture. iv) Titrate using method of the relaxer (alkalinity readings were triplicated).

[0149] Relaxer Alkalinity Measure:

[0150] [Table 4]

[0151] Interaction between the hair relaxer and the scalp protector showed a slight drop in the alkalinity readings suggesting that the straightening performances of the hair relaxer should not be significantly affected in presence of the scalp protector. The above results also supported the fact that scalp comfort, which lies in minimizing the presence of hydroxide ions in contact to the scalp, may be improved. Potentially, fewer hydroxide ions penetrate the scalp in the presence of the scalp protector, ultimately leading to a more comfortable experience.

Claims

CLAIMS1 . Use of a composition A comprising at least 80% by weight of vegetal oils and / or derivatives thereof, as scalp protector before relaxer treatment.

2. Use according to claim 1 wherein the composition A comprises one or more vegetal oils and derivatives thereof, more particularly one or more vegetal oils and caprylic / capric triglycerides, better a mixture of coconut oil, castor oil, sunflower seed oil and caprylic / capric triglyceride.

3. Use according to claim 2 wherein the total content of caprylic / capric triglycerides in the composition A ranges from 5 to 15% by weight, more preferably from 7 to 12% by weight, relative to the total weight of the composition.

4. Use according to one of the preceding claims wherein the total content of vegetal oil(s) and / or derivatives thereof in the composition A ranges from 80 to 95% by weight, more preferably 85 to 95% by weight, even more preferably from 90 to 95% by weight, relative to the total weight of the composition.

5. Use according to one of the preceding claims wherein the composition A comprises one or more waxes, preferably chosen from waxes of animal, plant or mineral origin, nonsilicone synthetic waxes, and mixtures thereof, more preferably plant waxes, better carnauba wax, candelilla wax and mixtures thereof, even better candelilla wax.

6. Use according to claim 5 wherein the total content of the wax(es) in the composition A ranges from 1 % to 20% by weight, more preferably from 2% to 18% by weight and better still from 4% to 10% by weight, relative to the total weight of the composition.

7. Use according to one of the preceding claims wherein the composition A comprises one or more ceramides or ceramides analogues such as glycoceramides, preferably chosen from the compounds having the following formula:in which:- R1 represents a linear or branched, saturated or unsaturated alkyl group derived from C14-C30 fatty acids, this group may be substituted by a hydroxyl group in the alpha position, or a hydroxyl roup in the omega position esterified by a saturated or unsaturated C16-C30 fatty acid;- R2 represents a hydrogen atom, a (glycosyl)n group, a (galactosyl)m group, or a sulfogalactosyl group, where n is an integer ranging from 1 to 4 and m is an integer ranging from 1 to 8;- R3 represents a C15-C26 hydrocarbon group, saturated or unsaturated in the alpha position, this group may be substituted by one or more C1 -C14 alkyl groups; it being understood that in the case of natural ceramides or glycoceramides, R3 may also represent a C15-C26 alpha-hydroxyalkyl group, the hydroxyl group optionally being esterified by a C16-C30 alpha-hydroxy acid.

8. Use according to one of the preceding claims wherein the composition A does not comprise mineral oil, nor petrolatum jelly.

9. Use according to one of the preceding claims wherein the composition A comprises at least one antioxidant agent chosen from tocopherol, its derivatives, salts thereof and their mixtures, preferably tocopherol and / or its esters of C1 -C24 carboxylic acid, more preferably its esters of C1 -C4 alkylcarboxylic acid, better to- copheryl acetate, more preferably in a total amount of 0.1 to 5% by weight, better from 0.2 to 3% by weight, better still from 0.3 to 1 % by weight, relative to the total weight of the composition.

10. Process for straightening keratin fibers comprising:- a step (i) of applying to the scalp of a composition A as defined in one of claims 1 to 9; then- a step (ii) of applying to the keratin fibers of a relaxing composition; then- a step (iii) of rinsing with water, and / or a washing step.11 . Process according to claim 10, in which the relaxing composition applied in step(ii ) is a “no-mix” relaxer, more preferably a composition C comprising: a) at least one alkali metal carbonate; b) calcium hydroxide; c) sodium or potassium metasilicate; and d) one or more fatty substance(s).

12. Process according to claim 11 , in which the fatty substances of the relaxing composition do not contain mineral oil, nor petrolatum jelly.

13. Relaxer kit comprising:(i) a first compartment containing a composition A as defined in one of claims 1 to 9; and(ii) a second compartment containing a relaxing composition, more preferably a “nomix” relaxer, more preferably a composition C comprising: a) at least one alkali metal carbonate; b) calcium hydroxide; c) sodium or potassium metasilicate; and d) one or more fatty substance(s); and / or(iii) a neutralizing shampoo.

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