Method for the preparation of a volatile mixture of alkanes and a cosmetic composition

Abstract

The invention relates to a method for the preparation of a cosmetic composition, the method being characterised in that it comprises a step of mixing the volatile mixture of alkanes obtained by a method according to any one of claims 1 to 13 with at least one compound selected from among non-volatile oils, glossy oils, pasty fatty substances, gelling agents, film-forming polymers, waxes, antioxidants, pigments, surfactants, an aqueous phase and mixtures thereof. The invention further relates to a method for the preparation of a cosmetic composition, the method comprising a step of mixing the volatile mixture of alkanes obtained by the above-mentioned method with at least one compound selected from among non-volatile oils, glossy oils, pasty fatty substances, gelling agents, film-forming polymers, waxes, antioxidants, pigments, surfactants, an aqueous phase and mixtures thereof.

Description

PROCESS FOR PREPARING A VOLATILE MIXTURE OF ALKANES AND COSMETIC COMPOSITION

[0001] The present application relates to a process for preparing a volatile mixture of alkanes.

[0002] The present application also relates to a process for preparing a cosmetic composition comprising this volatile mixture of alkanes.

[0003] The invention also relates to the resulting cosmetic composition.

[0004] As part of this request, a number of definitions must be given.

[0005] An "alkane" is a saturated hydrocarbon consisting solely of carbon and hydrogen atoms linked together by simple covalent bonds, the general formula of which is C n H2n+2.

[0006] A "linear alkane" is an alkane in which each carbon atom is linked to a maximum of two carbon atoms.

[0007] A "branched alkane" is an alkane in which some carbon atoms are linked to three or even four carbon atoms.

[0008] We call "C alkane" x » an alkane consisting of x carbon atoms, said alkane being able to be linear or branched. For example, dodecane is a C12 alkane.

[0009] A C>x alkane is an alkane consisting of at least x+1 carbon atoms, and the alkane can be linear or branched. For example, dodecane is a C>10 linear alkane or C12 alkane.

[0010] We call "C alkane" <x» un alcane constitué d'au plus x atomes de carbone ou de moins de x atomes de carbone, ledit alcane pouvant être linéaire ou ramifié, Par exemple le 2,3,6-triméthylheptane (CAS 4032-93-3) est un alcane en C< 10.

[0011] We call "C alkane" x -C y» an alkane consisting of x to y carbon atoms, said alkane being able to be linear or branched. For example, C1-C2 alkanes are methane and ethane.

[0012] An "isoalkane" is a branched alkane containing at least one carbon atom linked to at least three carbon atoms including a methyl group.

[0013] An "alcohol" is an organic compound in which one of the carbon atoms (this being tetrahedral) is linked to a hydroxyl group (-OH).

[0014] A "primary alcohol" is an alcohol whose carbon containing the hydroxyl group is linked to at least two hydrogen atoms and an organic radical R: R-CH2-OH. A "secondary alcohol" is an alcohol whose carbon containing the hydroxyl group is linked to a hydrogen atom and two organic radicals R and R': R(R')-CH-OH. We call "C alcohol" x» an alcohol consisting of x carbon atoms, said alcohol being able to be linear or branched, primary or secondary. For example, n-dodecanol (CAS 123-51-3) is a C12 alcohol.

[0015] We call "C alcohol" <x» un alcool constitué d'au plus x atomes de carbone ou moins de x atomes de carbone, ledit alcool pouvant être linéaire ou ramifié, primaire ou secondaire. Par exemple l'alcool isoamylique (CAS 123-51-3) est un alcool en C< 10.

[0016] A "C>10 alcohol" is an alcohol consisting of at least x+1 carbon atoms, said alcohol being able to be linear or branched, primary or secondary. For example, n-dodecanol (CAS 123-51-3) is a C>10 alcohol, or a C12 alcohol.

[0017] Commonly, a "volatile mixture of alkanes" is a mixture of alkanes having a flash point less than or equal to 95°C measured according to the ATSM D93 standard.

[0018] For the purposes of the present invention, the term “volatile mixture of alkanes” means a mixture of alkanes having a flash point less than or equal to 55°C measured according to the ATSM D93 standard.

[0019] The flash point is the flash point measured according to ASTM D93. The unit of the flash point measured according to ASTM D93 is degrees Celsius (°C). It can also be an average of values, each of which is obtained by means of a measurement according to ASTM D93.

[0020] The term "mass percentage" refers to the ratio of the mass of a first compound to the total mass of a mixture of compounds or composition, reduced to a percentage. For example, if 10 grams of a compound y are present in a mixture z having a total mass of 100 grams, then the mass percentage of y in z is 10%.

[0021] A "bio-sourced" compound or organic composition is defined as one in which the organic carbon present in the compound or composition is 100% of plant origin, i.e. the ratios 14 C / 12 Neck 14 C / 13 determined by radiocarbon analysis according to one of the following standards ASTM D6866, EN 16640 or EN 16785-1 correspond to the ratios of living plant products.

[0022] For the purposes of the present invention, the OECD 301F method makes it possible to assess the biodegradability of a substance by means of a manometric respirometry test.

[0023] The Guerbet synthesis is an organic condensation reaction, in which a primary or secondary alcohol bearing an adjacent methylene group to the carbon bearing the alcohol function condenses with itself or with another alcohol, with the release of water. This reaction leads to what are commonly called Guerbet alcohols.

[0024] For the purposes of the present invention, the term "Guerbet alcohol" refers to the product obtained by a Guerbet synthesis resulting from the condensation or dimerization with itself of an alcohol compound. In the context of the present invention, the Guerbet synthesis is carried out from a single alcohol compound.

[0025] The use of volatile silicone oils in cosmetic products is set to disappear, in particular the use of cyclomethicones which are short-chain cyclic silicone compounds of formula [Si(CH3)2-O] n with n between 3 and 7 (limits included). Indeed, their potential harmful effects on the environment, and even on human health, have recently been highlighted.

[0026] Research was then carried out to identify compounds likely to offer a satisfactory alternative, these compounds having to have similar volatility characteristics and provide similar properties to the formulation, in terms of viscosity and sensory properties in particular.

[0027] This research has highlighted the potential of alkane mixtures to reduce the use of volatile silicones in cosmetic products, or even potentially eliminate them. The alkane mixtures of interest can be complex, including several compounds and several types of alkanes, linear alkanes and branched alkanes. For example, patent application WO2009 / 064790A1 uses a mixture of three alkane fractions: a C12-C14 isoalkane fraction, a C13-C15 isoalkane fraction and a so-called C13-C15 alkane mixture fraction in very specific proportions. Obtaining properties at least similar to those obtained using volatile silicones is a real challenge and requires fine optimization of the composition of the mixture both in terms of proportions and structures of the alkanes used.

[0028] To date, the alkanes used as volatile solvents in cosmetic formulations, mainly isododecane, are mainly derived from petrochemicals. However, with limited oil resources and the oil market being volatile and polluting, meeting the demand for volatile alkanes for cosmetic formulations represents a strategic challenge for the cosmetics industry.

[0029] Branched alkanes are generally obtained as mixtures by polymerization or copolymerization reactions of unsaturated monomers, isobutene or isobutene / butene mixtures. Linear C>6 alkanes come from the cracking of heavy alkanes, a process leading in particular to the formation of unsaturated by-products of the alkene type.

[0030] The processes for producing alkanes from petrochemicals require the development of complex and costly purification processes due to the many by-products. Indeed, even in trace amounts, these impurities can significantly impact the quality of the alkanes obtained and severely limit their use.

[0031] The presence of alkene-type impurities has a deleterious effect on the storage stability of cosmetic formulations. Indeed, the oxidation of unsaturated bonds in the presence of oxygen leads in particular to accelerated degradation of the components of the composition.

[0032] In addition, alkenes and degradation products that appear during storage have an unpleasant odor that must be masked. The fact that this nauseating odor evolves between the time of production of the composition and the time of use of the product represents a real challenge for the formulator. This greatly complicates the development of a cosmetic composition that is acceptable to the sensitive nose of the consumer. In particular, such development may require the use of several fragrances or fragrances in larger quantities, which notably increases the risk of skin irritation.

[0033] Thus, there remains a need for highly pure volatile alkane mixtures with a well-defined and modular composition obtained from bio-sourced materials to develop their use as substitutes for volatile petrochemical products in cosmetic compositions.

[0034] Surprisingly, the Applicant has developed a process for producing a volatile mixture of alkanes having the following characteristics.

[0035] The process for producing a volatile mixture of alkanes according to the invention also makes it possible to produce volatile mixtures of alkanes having a biodegradability of at least 50% according to the OECD 301F method.

[0036] Advantageously, the process for producing a volatile mixture of alkanes according to the invention can be implemented under improved safety conditions, in particular avoiding the operator having to handle low flash point alkanes to produce a mixture of the latter.

[0037] Furthermore, the process for preparing the volatile mixture of alkanes according to the invention allows the preparation of cosmetic compositions which can have a naturalness index greater than or equal to 90%, more advantageously greater than or equal to 95%.

[0038] The invention relates to a process for preparing a volatile mixture of alkanes comprising the following steps: Step 1: production of a Guerbet alcohol by Guerbet synthesis from a bio-sourced linear or branched alcohol, Step 2: Add to the Guerbet alcohol formed in step 1 at least one bio-sourced linear or branched alcohol to form a mixture of bio-sourced alcohols, Step 3: obtaining a volatile mixture of alkanes consisting of the branched alkane derived from Guerbet alcohol and at least one alkane derived from the at least one bio-sourced alcohol added in step 2 by a dehydration reaction followed by a hydrogenation reaction of the mixture of bio-sourced alcohols formed in step 2.

[0039] In one embodiment, the invention relates to a method for preparing a volatile mixture of alkanes comprising the following steps: Step 1: the production of a Guerbet alcohol by Guerbet synthesis from a bio-sourced linear or branched alcohol with a mass purity greater than or equal to 80%, Step 2: Add to the Guerbet alcohol formed in step 1 at least one bio-sourced linear or branched alcohol to form a mixture of bio-sourced alcohols, Step 3: obtaining a volatile mixture of alkanes consisting of the branched alkane derived from Guerbet alcohol and at least one alkane derived from the at least one bio-sourced alcohol added in step 2 by a dehydration reaction followed by a hydrogenation reaction of the mixture of bio-sourced alcohols formed in step 2.

[0040] The invention also relates to a process for preparing a volatile mixture of alkanes comprising the following steps: Step 1: the production of a Guerbet alcohol by a Guerbet synthesis from a linear or branched biosourced alcohol in C< 10, Step 2: Add to the Guerbet alcohol formed in step 1 at least one linear or branched biosourced alcohol in C> 10 to form a mixture of biosourced alcohols, Step 3: obtaining a volatile mixture of alkanes consisting of the branched alkane derived from Guerbet alcohol and at least one alkane derived from the at least one bio-sourced alcohol added in step 2 by a dehydration reaction followed by a hydrogenation reaction of the mixture of bio-sourced alcohols formed in step 2.

[0041] The invention also relates to a process for preparing a volatile mixture of alkanes comprising the following steps: Step 1: Production of a Guerbet alcohol by Guerbet synthesis from a linear or branched biosourced C<10 alcohol with a mass purity greater than or equal to 80% Step 2: Add to the Guerbet alcohol formed in step 1 at least one linear or branched biosourced C>10 alcohol to form a mixture of biosourced alcohols Step 3: obtaining a volatile mixture of alkanes consisting of the branched alkane derived from Guerbet alcohol and at least one alkane derived from the at least one bio-sourced alcohol added in step 2 by a dehydration reaction followed by a hydrogenation reaction of the mixture of bio-sourced alcohols formed in step 2.

[0042] In particular, the invention relates to a process for preparing a volatile mixture of alkanes comprising the following steps: Step 1: production of a Guerbet alcohol by Guerbet synthesis from a biosourced branched alcohol in C< 10, Step 2: Add to the Guerbet alcohol formed in step 1 at least one linear or branched bio-sourced alcohol in C> 10 to form a mixture of bio-sourced alcohols Step 3: obtaining a volatile mixture of alkanes consisting of the branched alkane derived from Guerbet alcohol and at least one linear or branched alkane derived from the at least one biosourced alcohol added in step 2 by a dehydration reaction followed by a hydrogenation reaction of the mixture of biosourced alcohols formed in step 2.

[0043] More particularly, the invention relates to a process for preparing a volatile mixture of alkanes comprising the following steps: Step 1: Production of a Guerbet alcohol by Guerbet synthesis from a bio-sourced branched alcohol in C<10 with a mass purity greater than or equal to 80% Step 2: Add to the Guerbet alcohol formed in step 1 at least one linear or branched bio-sourced alcohol in C>10 to form a mixture of bio-sourced alcohols Step 3: obtaining a volatile mixture of alkanes consisting of the branched alkane derived from Guerbet alcohol and at least one linear or branched alkane derived from the at least one biosourced alcohol added in step 2 by a dehydration reaction followed by a hydrogenation reaction of the mixture of biosourced alcohols formed in step 2.

[0044] The invention relates more particularly to a process for preparing a volatile mixture of alkanes comprising the following steps: Step 1: Production of a Guerbet alcohol in CIO, 2-isopropyl-5-methylhexan-l-ol (CAS 2051-33-4), by synthesis from Guerbet from isoamyl alcohol (CAS 123-51-3) with a mass purity greater than or equal to 80% Step 2: Add to the 2-isopropyl-5-methylhexan-l-ol (CAS 2051-33-4) formed in step 1 at least one linear or branched biosourced C> 10 alcohol to form a mixture of biosourced alcohols Step 3: obtaining a volatile mixture of alkanes consisting of 2,3,6-trimethylheptane (CAS 4032-93-3) and at least one linear or branched C> 10 alkane by a dehydration reaction followed by a hydrogenation reaction of the mixture of biosourced alcohols formed in step 2

[0045] Advantageously, the volatile mixture of alkanes obtained by the process according to the invention has a biodegradability of at least 50% according to the OECD 301F method.

[0046] Step 1 of the process for preparing a volatile mixture of alkanes according to the invention consists of the production of a Guerbet alcohol by Guerbet synthesis from a bio-sourced linear or branched alcohol with a mass purity greater than or equal to 80%.

[0047] In one embodiment, the process for preparing a volatile mixture of alkanes according to the invention is characterized in that the Guerbet alcohol obtained during step 1 of the process is a compound of formula R-CH2-CH2-CH(R)-CH2-OH resulting from a Guerbet synthesis from a biosourced linear or branched alcohol of formula R-CH2-CH2-OH, R being a linear or branched alkyl chain comprising from 1 to 6 carbon atoms.

[0048] In one embodiment, the process for preparing a volatile mixture of alkanes according to the invention is characterized in that the Guerbet alcohol obtained during step 1 of the process is a compound of formula R'-CH2-CH(R")-CH(R')-CH(R")- OH resulting from a Guerbet synthesis from a biosourced branched alcohol of formula R'- CH2-CH(R")-OH, R' and R" being identical or different, linear or branched alkyl chains, comprising from 1 to 6 carbon atoms.

[0049] In one embodiment, the process for preparing a volatile mixture of alkanes according to the invention is characterized in that step 1 of the process is carried out from an alcohol of plant, bacterial or animal origin.

[0050] In one embodiment, the process for preparing a volatile mixture of alkanes according to the invention is characterized in that step 1 of the process is carried out from an alcohol of plant origin.

[0051] In one embodiment, the process for preparing a volatile mixture of alkanes according to the invention is characterized in that step 1 of the process is carried out from a biosourced linear or branched alcohol in C<10.

[0052] In one embodiment, the process for preparing a volatile mixture of alkanes according to the invention is characterized in that step 1 of the process is carried out from a biosourced linear or branched alcohol in C<10 chosen from the group consisting of isoamyl alcohol (CAS 123-51-3), isobutyl alcohol (CAS 78-83-1), 1-hexanol (CAS 111-27-3) and 1-heptanol (CAS 111-70-6).

[0053] In one embodiment, the process for preparing a volatile mixture of alkanes according to the invention is characterized in that step 1 of the process is carried out from isoamyl alcohol (CAS 123-51-3).

[0054] In one embodiment, the process for preparing a volatile mixture of alkanes according to the invention is characterized in that step 1 of the process is carried out from 1-hexanol (CAS 111-27-3).

[0055] In one embodiment, the process for preparing a volatile mixture of alkanes according to the invention is characterized in that step 1 of the process is carried out using at least one base and at least one catalyst.

[0056] In one embodiment, the process for preparing a volatile mixture of alkanes according to the invention is characterized in that step 1 of the process is carried out using at least one base chosen from the group consisting of KOH, NaOH, NaOCH3 and KOCH3.

[0057] In one embodiment, the process for preparing a volatile mixture of alkanes according to the invention is characterized in that step 1 of the process is carried out using at least one catalyst chosen from the group consisting of copper derivatives such as PriCat Cu 50 / 8, a group VIII metal such as nickel, palladium, platinum, their derivatives and their mixtures.

[0058] In one embodiment, the process for preparing a volatile mixture of alkanes according to the invention is characterized in that step 1 of the process is carried out using at least the PriCat Cu 50 / 8 catalyst.

[0059] In one embodiment, the process for preparing a volatile mixture of alkanes according to the invention is characterized in that step 1 of the process is carried out at temperatures between 150 and 300°C.

[0060] In one embodiment, the process for preparing a volatile mixture of alkanes according to the invention is characterized in that step 1 of the process is carried out at temperatures between 170 and 260°C.

[0061] In one embodiment, the process for preparing a volatile mixture of alkanes according to the invention is characterized in that step 1 of the process is carried out at temperatures between 180 and 230°C.

[0062] In one embodiment, the process for preparing a volatile mixture of alkanes according to the invention is characterized in that step 1 of the process is carried out at pressures between 1 and 15 bars.

[0063] In one embodiment, the process for preparing a volatile mixture of alkanes according to the invention is characterized in that step 1 of the process is carried out at atmospheric pressure.

[0064] In one embodiment, the process for preparing a volatile mixture of alkanes according to the invention is characterized in that step 1 of the process is carried out for a period of between 10 and 24 hours.

[0065] In one embodiment, the process for preparing a volatile mixture of alkanes according to the invention is characterized in that step 1 of the process is carried out for a period of 24 hours.

[0066] In one embodiment, the process for preparing a volatile mixture of alkanes according to the invention is characterized in that step 1 of the process further comprises a step of purification by distillation to remove impurities.

[0067] In one embodiment, the process for preparing a volatile mixture of alkanes according to the invention is characterized in that step 1 of the process can be carried out according to the conditions described in patent applications EP2913319A1, WO02 / 24616A1, WO2011 / 054483A1, WO2017 / 093473A1 and W02020 / 093127A1 in particular.

[0068] In one embodiment, the process for preparing a volatile mixture of alkanes according to the invention is characterized in that step 1 of the process makes it possible to obtain a mass percentage of Guerbet alcohol greater than or equal to 75%.

[0069] In one embodiment, the process for preparing a volatile mixture of alkanes according to the invention is characterized in that step 1 of the process makes it possible to obtain a mass percentage of Guerbet alcohol greater than or equal to 90%.

[0070] In one embodiment, the process for preparing a volatile mixture of alkanes according to the invention is characterized in that step 1 of the process makes it possible to obtain a branched alcohol whose percentage of carbon 14 ( 14 C) is greater than or equal to 75% determined according to one of the following standards ASTM D6866, EN 16640 or EN 16785-1.

[0071] In one embodiment, the process for preparing a volatile mixture of alkanes according to the invention is characterized in that step 1 of the process makes it possible to obtain a branched alcohol whose percentage of carbon 14 ( 14 C) is greater than or equal to 90% determined according to one of the following standards ASTM D6866, EN 16640 or EN 16785-1.

[0072] In one embodiment, the process for preparing a volatile mixture of alkanes according to the invention is characterized in that step 1 of the process makes it possible to obtain a branched alcohol whose percentage of carbon 14 ( 14C) is 100% determined according to one of the following standards ASTM D6866, EN 16640 or EN 16785-1.

[0073] In one embodiment, the process for preparing a volatile mixture of alkanes according to the invention is characterized in that the Guerbet alcohol obtained during step 1 of the process is 2-isopropyl-5-methylhexan-1-ol.

[0074] In one embodiment, the process for preparing a volatile mixture of alkanes according to the invention is characterized in that the Guerbet alcohol obtained during step 1 of the process is 2-butyloctan-1-ol.

[0075] Step 2 of the process for preparing a volatile mixture of alkanes according to the invention consists of adding to the Guerbet alcohol obtained during step 1 at least one bio-sourced linear or branched alcohol to form a mixture of bio-sourced alcohols.

[0076] In one embodiment, the process for preparing a volatile mixture of alkanes according to the invention is characterized in that the at least one alcohol added to the Guerbet alcohol during step 2 of the process is a bio-sourced linear alcohol.

[0077] In one embodiment, the process for preparing a volatile mixture of alkanes according to the invention is characterized in that the at least one alcohol added to the Guerbet alcohol during step 2 of the process is a biosourced linear alcohol in C> 10.

[0078] In one embodiment, the process for preparing a volatile mixture of alkanes according to the invention is characterized in that the at least one alcohol added to the Guerbet alcohol during step 2 of the process is a biosourced linear alcohol in C> 10 chosen from the group consisting of n-decanol, n-dodecanol and n-tetradecanol.

[0079] In one embodiment, the process for preparing a volatile mixture of alkanes according to the invention is characterized in that the at least one alcohol added to the Guerbet alcohol during step 2 of the process is n-decanol.

[0080] In one embodiment, the process for preparing a volatile mixture of alkanes according to the invention is characterized in that the at least one alcohol added to the Guerbet alcohol during step 2 of the process is n-dodecanol.

[0081] In one embodiment, the process for preparing a volatile mixture of alkanes according to the invention is characterized in that the at least one alcohol added to the Guerbet alcohol during step 2 of the process is n-tetradecanol.

[0082] In one embodiment, the process for preparing a volatile mixture of alkanes according to the invention is characterized in that the alcohol used in step 1 and the alcohol added to the Guerbet alcohol in step 2 are of plant origin.

[0083] In one embodiment, the process for preparing a volatile mixture of alkanes according to the invention is characterized in that the alcohol used in step 1 is isoamyl alcohol and the at least one alcohol added to the Guerbet alcohol in step 2 is n-dodecanol.

[0084] In one embodiment, the process for preparing a volatile mixture of alkanes according to the invention is characterized in that the alcohol used in step 1 is 1-hexanol and the at least one alcohol added to the Guerbet alcohol in step 2 is n-dodecanol.

[0085] In one embodiment, the process for preparing a volatile mixture of alkanes according to the invention is characterized in that the at least one alcohol added to the Guerbet alcohol during step 2 of the process is a bio-sourced branched alcohol.

[0086] In one embodiment, the process for preparing a volatile mixture of alkanes according to the invention is characterized in that the at least one alcohol added to the Guerbet alcohol during step 2 of the process is a bio-sourced branched alcohol resulting from a Guerbet synthesis.

[0087] In one embodiment, the process for preparing a volatile mixture of alkanes according to the invention is characterized in that the at least one alcohol added to the Guerbet alcohol during step 2 of the process is a biosourced branched alcohol resulting from a Guerbet synthesis chosen from the group consisting of 2-butyloctan-1-ol and 2-isopropyl-5-methylhexan-1-ol.

[0088] In one embodiment, the process for preparing a volatile mixture of alkanes according to the invention is characterized in that the at least one alcohol resulting from a Guerbet synthesis added to the Guerbet alcohol during step 2 of the process is 2-butyloctan-1-ol.

[0089] In one embodiment, the process for preparing a volatile mixture of alkanes according to the invention is characterized in that the at least one alcohol resulting from a Guerbet synthesis added to the Guerbet alcohol during step 2 of the process is 2-isopropyl-5-methylhexan-1-ol.

[0090] In one embodiment, the process for preparing a volatile mixture of alkanes according to the invention is characterized in that the at least one alcohol added to the Guerbet alcohol during step 2 of the process is a biosourced branched alcohol in C> 10.

[0091] In one embodiment, the process for preparing a volatile mixture of alkanes according to the invention is characterized in that two bio-sourced alcohols are added to the Guerbet alcohol during step 2 of the process.

[0092] In one embodiment, the process for preparing a volatile mixture of alkanes according to the invention is characterized in that two bio-sourced linear alcohols are added to the Guerbet alcohol during step 2 of the process.

[0093] In one embodiment, the process for preparing a volatile mixture of alkanes according to the invention is characterized in that two bio-sourced branched alcohols are added to the Guerbet alcohol during step 2 of the process.

[0094] In one embodiment, the process for preparing a volatile mixture of alkanes according to the invention is characterized in that a bio-sourced linear alcohol and a bio-sourced branched alcohol are added to the Guerbet alcohol during step 2 of the process.

[0095] In one embodiment, the process for preparing a volatile mixture of alkanes according to the invention is characterized in that 1-dodecanol and 2-butyloctan-1-ol are added to the Guerbet alcohol during step 2 of the process.

[0096] In one embodiment, the process for preparing a volatile mixture of alkanes according to the invention is characterized in that the mixture of biosourced alcohols formed during step 2 of the process comprises at least 20% by mass of the Guerbet alcohol obtained during step 1 relative to the total mass of the mixture.

[0097] In one embodiment, the process for preparing a volatile mixture of alkanes according to the invention is characterized in that the mixture of biosourced alcohols formed during step 2 of the process comprises at least 50% by mass of Guerbet alcohol relative to the total mass of the mixture.

[0098] In one embodiment, the process for preparing a volatile mixture of alkanes according to the invention is characterized in that the mass percentage of Guerbet alcohol is between 20% and 95% relative to the total mass of the mixture of biosourced alcohols.

[0099] In one embodiment, the process for preparing a volatile mixture of alkanes according to the invention is characterized in that the mass percentage of Guerbet alcohol is between 20% and 70% relative to the total mass of the mixture of biosourced alcohols. [000100] In one embodiment, the process for preparing a volatile mixture of alkanes according to the invention is characterized in that the mass percentage of Guerbet alcohol is between 51% and 95% relative to the total mass of the mixture of biosourced alcohols. [000101] In one embodiment, the process for preparing a volatile mixture of alkanes according to the invention is characterized in that the mass percentage of Guerbet alcohol is between 30% and 60% relative to the total mass of the mixture of biosourced alcohols. [000102] In one embodiment, the process for preparing a volatile mixture of alkanes according to the invention is characterized in that the mass percentage of Guerbet alcohol is between 40% and 70% relative to the total mass of the mixture of biosourced alcohols. [000103] In one embodiment, the process for preparing a volatile mixture of alkanes according to the invention is characterized in that the mass percentage of Guerbet alcohol is between 50% and 80% of the total mass of the bio-sourced alcohol mixture. [000104] In one embodiment, the process for preparing a volatile mixture of alkanes according to the invention is characterized in that the mass percentage of Guerbet alcohol is between 30% and 50% relative to the total mass of the mixture of biosourced alcohols. [000105] In one embodiment, the process for preparing a volatile mixture of alkanes according to the invention is characterized in that the mass percentage of Guerbet alcohol is between 40% and 60% relative to the total mass of the mixture of biosourced alcohols. [000106] In one embodiment, the process for preparing a volatile mixture of alkanes according to the invention is characterized in that the mass percentage of Guerbet alcohol is between 50% and 70% relative to the total mass of the mixture of biosourced alcohols. [000107] In one embodiment, the process for preparing a volatile mixture of alkanes according to the invention is characterized in that the mass percentage of Guerbet alcohol is between 60% and 80% relative to the total mass of the mixture of biosourced alcohols. [000108] In one embodiment, the process for preparing a volatile mixture of alkanes according to the invention is characterized in that the mass percentage of Guerbet alcohol is between 70% and 90% relative to the total mass of the mixture of biosourced alcohols. [000109] Step 3 of the process for preparing a volatile mixture of alkanes according to the invention consists of obtaining a volatile mixture of alkanes consisting of the branched alkane derived from the Guerbet alcohol obtained during step 1 and at least one alkane derived from the at least one biosourced alcohol added in step 2 by a dehydration reaction followed by a hydrogenation reaction of the mixture of biosourced alcohols formed in step 2. [000110] In one embodiment, the process for preparing a volatile mixture of alkanes according to the invention is characterized in that the dehydration reaction of step 3 of the process is carried out using a catalyst. [000111] In one embodiment, the process for preparing a volatile mixture of alkanes according to the invention is characterized in that the dehydration reaction of step 3 of the process is carried out using a catalyst chosen from the group consisting of alumina and its derivatives. [000112] In one embodiment, the process for preparing a volatile mixture of alkanes according to the invention is characterized in that the dehydration reaction of step 3 of the process is carried out using a supported catalyst. [000113] In one embodiment, the process for preparing a volatile mixture of alkanes according to the invention is characterized in that the dehydration reaction of step 3 of the process is carried out using a catalytic support chosen from the group consisting of silica wool and its derivatives. [000114] In one embodiment, the process for preparing a volatile mixture of alkanes according to the invention is characterized in that the dehydration reaction of step 3 of the process is carried out at temperatures of between 200 and 380°C. [000115] In one embodiment, the process for preparing a volatile mixture of alkanes according to the invention is characterized in that the dehydration reaction of step 3 of the process is carried out at temperatures of between 250 and 350°C. [000116] In one embodiment, the process for preparing a volatile mixture of alkanes according to the invention is characterized in that the dehydration reaction of step 3 of the process is carried out at approximately 330°C. [000117] In one embodiment, the process for preparing a volatile mixture of alkanes according to the invention is characterized in that the dehydration reaction of step 3 of the process is carried out under an inert atmosphere. [000118] In one embodiment, the process for preparing a volatile mixture of alkanes according to the invention is characterized in that the dehydration reaction of step 3 of the process makes it possible to obtain a conversion into alkenes greater than or equal to 95%. [000119] In one embodiment, the process for preparing a volatile mixture of alkanes according to the invention is characterized in that the dehydration reaction of step 3 of the process makes it possible to obtain a conversion into alkenes greater than or equal to 99%. [000120] In one embodiment, the process for preparing a volatile mixture of alkanes according to the invention is characterized in that the dehydration reaction of step 3 of the process is carried out continuously. [000121] In one embodiment, the process for preparing a volatile mixture of alkanes according to the invention is characterized in that the dehydration reaction of step 3 of the process does not comprise a purification step. [000122] In one embodiment, the process for preparing a volatile mixture of alkanes according to the invention is characterized in that the hydrogenation reaction of step 3 of the process is carried out using a catalyst. [000123] In one embodiment, the process for preparing a volatile mixture of alkanes according to the invention is characterized in that the hydrogenation reaction of step 3 of the process is carried out using a catalyst comprising at least one metal from group VIII such as palladium, nickel, platinum, their derivatives and their mixtures. [000124] In one embodiment, the process for preparing a volatile mixture of alkanes according to the invention is characterized in that the hydrogenation reaction of step 3 of the process is carried out using a supported catalyst. [000125] In one embodiment, the process for preparing a volatile mixture of alkanes according to the invention is characterized in that the hydrogenation reaction of step 3 of the process is carried out using a catalytic support chosen from the group consisting of silica wool and its derivatives. [000126] In one embodiment, the process for preparing a volatile mixture of alkanes according to the invention is characterized in that the hydrogenation reaction of step 3 of the process is carried out at temperatures between 100 and 250°C. [000127] In one embodiment, the process for preparing a volatile mixture of alkanes according to the invention is characterized in that the hydrogenation reaction of step 3 of the process is carried out at temperatures between 150 and 250°C. [000128] In one embodiment, the process for preparing a volatile mixture of alkanes according to the invention is characterized in that the hydrogenation reaction of step 3 of the process is carried out at temperatures between 170 and 220°C.[000129] In one embodiment, the process for preparing a volatile mixture of alkanes according to the invention is characterized in that the hydrogenation reaction of step 3 of the process is carried out by heating at at least one temperature level. [000130] In one embodiment, the process for preparing a volatile mixture of alkanes according to the invention is characterized in that the hydrogenation reaction of step 3 of the process is carried out by heating at two different temperature levels. [000131] In one embodiment, the process for preparing a volatile mixture of alkanes according to the invention is characterized in that the hydrogenation reaction of step 3 of the process is carried out by heating to a temperature level of approximately 180°C and a temperature level of approximately 200°C. [000132] In one embodiment, the process for preparing a volatile mixture of alkanes according to the invention is characterized in that the hydrogenation reaction of step 3 of the process is carried out under an inert atmosphere. [000133] In one embodiment, the process for preparing a volatile mixture of alkanes according to the invention is characterized in that the hydrogenation reaction of step 3 of the process is carried out under an inert nitrogen atmosphere. [000134] In one embodiment, the process for preparing a volatile mixture of alkanes according to the invention is characterized in that the hydrogenation reaction of step 3 of the process is preceded by at least one nitrogen inerting cycle in the reactor. [000135] In one embodiment, the process for preparing a volatile mixture of alkanes according to the invention is characterized in that the hydrogenation reaction of step 3 of the process is preceded by inerting with 15 bars of nitrogen in the reactor. [000136] In one embodiment, the process for preparing a volatile mixture of alkanes according to the invention is characterized in that the hydrogenation reaction of step 3 of the process is preceded by several cycles of inerting with nitrogen in the reactor. [000137] In one embodiment, the process for preparing a volatile mixture of alkanes according to the invention is characterized in that the hydrogenation reaction of step 3 of the process is preceded by three cycles of inerting with nitrogen in the reactor. [000138] In one embodiment, the process for preparing a volatile mixture of alkanes according to the invention is characterized in that the hydrogenation reaction of step 3 of the process is preceded by three cycles of inerting with 5 bars of nitrogen in the reactor. [000139] In one embodiment, the process for preparing a volatile mixture of alkanes according to the invention is characterized in that the hydrogenation reaction of step 3 of the process is carried out by at least one addition of hydrogen to the reactor. [000140] In one embodiment, the process for preparing a volatile mixture of alkanes according to the invention is characterized in that the hydrogenation reaction of step 3 of the process is carried out by the addition of 2 to 15 bars of hydrogen to the reactor. [000141] In one embodiment, the process for preparing a volatile mixture of alkanes according to the invention is characterized in that the hydrogenation reaction of step 3 of the process is carried out by adding at least 5 bars of hydrogen to the reactor. [000142] In one embodiment, the process for preparing a volatile mixture of alkanes according to the invention is characterized in that the hydrogenation reaction of step 3 of the process is carried out by adding at least 10 bars of hydrogen to the reactor. [000143] In one embodiment, the process for preparing a volatile mixture of alkanes according to the invention is characterized in that the hydrogenation reaction of step 3 of the process is carried out for a period of 3 to 12 hours. [000144] In one embodiment, the process for preparing a volatile mixture of alkanes according to the invention is characterized in that the hydrogenation reaction of step 3 of the process is carried out for a period of 4 to 8 hours. [000145] In one embodiment, the process for preparing a volatile mixture of alkanes according to the invention is characterized in that the hydrogenation reaction of step 3 of the process is carried out for a period of 5 hours. [000146] In one embodiment, the process for preparing a volatile mixture of alkanes according to the invention is characterized in that the hydrogenation reaction of step 3 of the process makes it possible to obtain a conversion into a volatile mixture of alkanes greater than or equal to 95%. [000147] In one embodiment, the process for preparing a volatile mixture of alkanes according to the invention is characterized in that the hydrogenation reaction of step 3 of the process makes it possible to obtain a conversion into a volatile mixture of alkanes greater than or equal to 99%. [000148] In one embodiment, the process for preparing a volatile mixture of alkanes according to the invention is characterized in that the volatile mixture of alkanes obtained in step 3 contains at least 20% by mass of the branched alkane derived from Guerbet alcohol and at least 20% by mass of at least one alkane derived from the at least one biosourced alcohol added in step 2, relative to the total mass of the volatile mixture of alkanes. [000149] In one embodiment, the process for preparing a volatile mixture of alkanes according to the invention is characterized in that the volatile mixture of alkanes obtained in step 3 comprises at least 20% by mass of the branched alkane derived from Guerbet alcohol relative to the total mass of the mixture. [000150] In one embodiment, the process for preparing a volatile mixture of alkanes according to the invention is characterized in that the volatile mixture of alkanes obtained in step 3 comprises at least 50% by mass of the branched alkane derived from Guerbet alcohol relative to the total mass of the mixture. [000151] In one embodiment, the process for preparing a volatile mixture of alkanes according to the invention is characterized in that the mass percentage of the branched alkane derived from Guerbet alcohol is between 20% and 95% relative to the total mass of the volatile mixture of alkanes. [000152] In one embodiment, the process for preparing a volatile mixture of alkanes according to the invention is characterized in that the mass percentage of the branched alkane derived from Guerbet alcohol is between 20% and 70% relative to the total mass of the volatile mixture of alkanes. [000153] In one embodiment, the process for preparing a volatile mixture of alkanes according to the invention is characterized in that the mass percentage of the branched alkane derived from Guerbet alcohol is between 51% and 95% relative to the total mass of the volatile mixture of alkanes. [000154] In one embodiment, the process for preparing a volatile mixture of alkanes according to the invention is characterized in that the mass percentage of the branched alkane derived from Guerbet alcohol is between 30% and 60% relative to the total mass of the volatile mixture of alkanes. [000155] In one embodiment, the process for preparing a volatile mixture of alkanes according to the invention is characterized in that the mass percentage of the branched alkane derived from Guerbet alcohol is between 40% and 70% relative to the total mass of the volatile mixture of alkanes. [000156] In one embodiment, the process for preparing a volatile mixture of alkanes according to the invention is characterized in that the mass percentage of the branched alkane derived from Guerbet alcohol is between 50% and 80% relative to the total mass of the volatile mixture of alkanes. [000157] In one embodiment, the process for preparing a volatile mixture of alkanes according to the invention is characterized in that the mass percentage of the branched alkane derived from Guerbet alcohol is between 30% and 50% relative to the total mass of the volatile mixture of alkanes. [000158] In one embodiment, the process for preparing a volatile mixture of alkanes according to the invention is characterized in that the mass percentage of the branched alkane derived from Guerbet alcohol is between 40% and 60% relative to the total mass of the volatile mixture of alkanes. [000159] In one embodiment, the process for preparing a volatile mixture of alkanes according to the invention is characterized in that the mass percentage of the branched alkane derived from Guerbet alcohol is between 50% and 70% relative to the total mass of the volatile mixture of alkanes. [000160] In one embodiment, the process for preparing a volatile mixture of alkanes according to the invention is characterized in that the mass percentage of the branched alkane derived from Guerbet alcohol is between 60% and 80% relative to the total mass of the volatile mixture of alkanes. [000161] In one embodiment, the process for preparing a volatile mixture of alkanes according to the invention is characterized in that the mass percentage of the branched alkane derived from Guerbet alcohol is between 70% and 90% relative to the total mass of the volatile mixture of alkanes. [000162] In one embodiment, the process for preparing a volatile mixture of alkanes according to the invention is characterized in that the volatile mixture of alkanes obtained in step 3 contains at least 5-methylundecane. [000163] In one embodiment, the process for preparing a volatile mixture of alkanes according to the invention is characterized in that the volatile mixture of alkanes obtained in step 3 contains 5-methylundecane and at least one alkane chosen from the group consisting of n-decane, n-dodecane and n-tetradecane. [000164] In one embodiment, the process for preparing a volatile mixture of alkanes according to the invention is characterized in that the volatile mixture of alkanes obtained in step 3 consists of: - 50% 5-methylundecane (CAS 1632-70-8) - 50% n-dodecane (CAS 112-40-3). [000165] In one embodiment, the process for preparing a volatile mixture of alkanes according to the invention is characterized in that the volatile mixture of alkanes obtained in step 3 contains at least 2,3,6-trimethylheptane. [000166] In one embodiment, the process for preparing a volatile mixture of alkanes according to the invention is characterized in that the volatile mixture of alkanes obtained in step 3 contains 2,3,6-trimethylheptane and at least one alkane chosen from the group consisting of n-decane, n-dodecane and n-tetradecane. [000167] In one embodiment, the process for preparing a volatile mixture of alkanes according to the invention is characterized in that the volatile mixture of alkanes obtained in step 3 consists of 2,3,6-trimethylheptane and n-decane. [000168] In one embodiment, the process for preparing a volatile mixture of alkanes according to the invention is characterized in that the volatile mixture of alkanes obtained in step 3 consists of 2,3,6-trimethylheptane and n-dodecane. [000169] In one embodiment, the process for preparing a volatile mixture of alkanes according to the invention is characterized in that the volatile mixture of alkanes obtained in step 3 contains at least 20% by mass of 2,3,6-trimethylheptane and at least 20% by mass of at least one linear alkane chosen from the group consisting of n-decane, n-dodecane and n-tetradecane, relative to the total mass of the volatile mixture of alkanes. [000170] In one embodiment, the process for preparing a volatile mixture of alkanes according to the invention is characterized in that the volatile mixture of alkanes obtained in step 3 contains at least 20% by mass of 2,3,6-trimethylheptane and at least 20% by mass of n-dodecane, relative to the total mass of the volatile mixture of alkanes. [000171] In one embodiment, the process for preparing a volatile mixture of alkanes according to the invention is characterized in that the volatile mixture of alkanes obtained in step 3 consists of: - 20 to 80% of 2,3,6-trimethylheptane (CAS 4032-93-3) - 20 to 80% n-dodecane (CAS 112-40-3). [000172] In one embodiment, the process for preparing a volatile mixture of alkanes according to the invention is characterized in that the volatile mixture of alkanes obtained in step 3 consists of: - 20 to 70% of 2,3,6-trimethylheptane (CAS 4032-93-3) - 30 to 80% n-dodecane (CAS 112-40-3). [000173] In one embodiment, the process for preparing a volatile mixture of alkanes according to the invention is characterized in that the volatile mixture of alkanes obtained in step 3 consists of: - 30% 2,3,6-trimethylheptane (CAS 4032-93-3) - 70% n-dodecane (CAS 112-40-3). [000174] In one embodiment, the process for preparing a volatile mixture of alkanes according to the invention is characterized in that the volatile mixture of alkanes obtained in step 3 consists of: - 35% 2,3,6-trimethylheptane (CAS 4032-93-3) - 65% n-dodecane (CAS 112-40-3). [000175] In one embodiment, the process for preparing a volatile mixture of alkanes according to the invention is characterized in that the volatile mixture of alkanes obtained in step 3 consists of: - 40% 2,3,6-trimethylheptane (CAS 4032-93-3) - 60% n-dodecane (CAS 112-40-3). [000176] In one embodiment, the process for preparing a volatile mixture of alkanes according to the invention is characterized in that the volatile mixture of alkanes obtained in step 3 consists of: - 45% 2,3,6-trimethylheptane (CAS 4032-93-3) - 55% n-dodecane (CAS 112-40-3). [000177] In one embodiment, the process for preparing a volatile mixture of alkanes according to the invention is characterized in that the volatile mixture of alkanes obtained in step 3 consists of: - 60% 2,3,6-trimethylheptane (CAS 4032-93-3) - 40% n-dodecane (CAS 112-40-3). [000178] In one embodiment, the process for preparing a volatile mixture of alkanes according to the invention is characterized in that the volatile mixture of alkanes obtained in step 3 consists of: - 70% 2,3,6-trimethylheptane (CAS 4032-93-3) - 30% n-dodecane (CAS 112-40-3). [000179] In one embodiment, the process for preparing a volatile mixture of alkanes according to the invention is characterized in that the volatile mixture of alkanes obtained in step 3 consists of: - 90% 2,3,6-trimethylheptane (CAS 4032-93-3) - 10% n-dodecane (CAS 112-40-3). [000180] In one embodiment, the process for preparing a volatile mixture of alkanes according to the invention is characterized in that the volatile mixture of alkanes obtained in step 3 consists of 2,3,6-trimethylheptane and n-tetradecane. [000181] In one embodiment, the process for preparing a volatile mixture of alkanes according to the invention is characterized in that the volatile mixture of alkanes obtained in step 3 consists of a branched alkane derived from the Guerbet alcohol obtained in step 1 and at least one branched alkane derived from the at least one biosourced alcohol added in step 2. [000182] In one embodiment, the process for preparing a volatile mixture of alkanes according to the invention is characterized in that the volatile mixture of alkanes obtained in step 3 consists of 2,3,6-trimethylheptane and 5-methylundecane. [000183] In one embodiment, the process for preparing a volatile mixture of alkanes according to the invention is characterized in that the volatile mixture of alkanes obtained in step 3 consists of a branched alkane derived from the Guerbet alcohol obtained in step 1 and at least one branched alkane and one linear alkane derived from at least two biosourced alcohols added in step 2. [000184] In one embodiment, the process for preparing a volatile mixture of alkanes according to the invention is characterized in that the volatile mixture of alkanes obtained in step 3 consists of 2,3,6-trimethylheptane, 5-methylundecane and n-dodecane. [000185] In one embodiment, the process for preparing a volatile mixture of alkanes according to the invention is characterized in that the volatile mixture of alkanes obtained in step 3 consists of: - 30% 2,3,6-trimethylheptane (CAS 4032-93-3) - 30% 5-methylundecane (CAS 1632-70-8) - 40% n-dodecane (CAS 112-40-3). [000186] In one embodiment, the process for preparing a volatile mixture of alkanes according to the invention is characterized in that the flash point of the volatile mixture of alkanes obtained in step 3 is less than or equal to 50°C. [000187] In one embodiment, the process for preparing a volatile mixture of alkanes according to the invention is characterized in that the flash point of the volatile mixture of alkanes obtained in step 3 is between 45°C and 50°C. [000188] In one embodiment, the process for preparing a volatile mixture of alkanes according to the invention is characterized in that the flash point of the volatile mixture of alkanes obtained in step 3 is less than or equal to 45°C. [000189] In one embodiment, the process for preparing a volatile mixture of alkanes according to the invention is characterized in that the flash point of the volatile mixture of alkanes obtained in step 3 is between 40°C and 45°C. [000190] In one embodiment, the process for preparing a volatile mixture of alkanes according to the invention is characterized in that the flash point of the volatile mixture of alkanes obtained in step 3 is less than or equal to 40°C. [000191] In one embodiment, the process for preparing a volatile mixture of alkanes according to the invention is characterized in that the flash point of the volatile mixture of alkanes obtained in step 3 is between 35°C and 40°C. [000192] In one embodiment, the process for preparing a volatile mixture of alkanes according to the invention is characterized in that the volatile mixture of alkanes obtained in step 3 has a percentage of carbon 14 ( 14 C) greater than or equal to 75% determined according to one of the following standards ASTM D6866, EN 16640 or EN 16785-1. [000193] In one embodiment, the process for preparing a volatile mixture of alkanes according to the invention is characterized in that the volatile mixture of alkanes obtained in step 3 has a percentage of carbon 14 ( 14 C) greater than or equal to 90% determined according to one of the following standards ASTM D6866, EN 16640 or EN 16785-1. [000194] In one embodiment, the process for preparing a volatile mixture of alkanes according to the invention is characterized in that the volatile mixture of alkanes obtained in step 3 has a percentage of carbon 14 ( 14C) 100% determined according to one of the following standards ASTM D6866, EN 16640 or EN 16785-1. [000195] In one embodiment, the process for preparing a volatile mixture of alkanes according to the invention is characterized in that the volatile mixture of alkanes obtained in step 3 has a biodegradability of at least 50% according to the OECD 301F method. [000196] In one embodiment, the process for preparing a volatile mixture of alkanes according to the invention is characterized in that the volatile mixture of alkanes obtained in step 3 has a biodegradability of at least 60% according to the OECD 301F method. [000197] In one embodiment, the process for preparing a volatile mixture of alkanes according to the invention is characterized in that the volatile mixture of alkanes obtained in step 3 has a biodegradability of between 50 and 80% according to the OECD 301F method. [000198] In one embodiment, the process for preparing a volatile mixture of alkanes according to the invention is characterized in that the volatile mixture of alkanes obtained in step 3 has a biodegradability of between 50 and 70% according to the OECD 301F method. [000199] In one embodiment, the process for preparing a volatile mixture of alkanes according to the invention is characterized in that the volatile mixture of alkanes obtained in step 3 has a biodegradability of between 50 and 60% according to the OECD 301F method. [000200] In one embodiment, the process for preparing a volatile mixture of alkanes according to the invention is characterized in that the volatile mixture of alkanes obtained in step 3 has a biodegradability of between 60 and 70% according to the OECD 301F method. [000201] In one embodiment, the process for preparing a volatile mixture of alkanes according to the invention is characterized in that the volatile mixture of alkanes obtained in step 3 has a biodegradability of between 70 and 80% according to the OECD 301F method. [000202] Surprisingly, the process for preparing a volatile mixture of alkanes according to the invention is characterized in that the volatile mixture of alkanes obtained in step 3 is deodorized or odorless. [000203] The invention also relates to a process for preparing a cosmetic composition further comprising a step of mixing a volatile mixture of alkanes obtained by the process according to the invention with at least one compound chosen from non-volatile oils, glossy oils, pasty fatty substances, gelling agents, film-forming polymers, waxes, antioxidants, pigments, dyes, surfactants, an aqueous phase, and mixtures thereof. [000204] In one embodiment, the process for preparing a cosmetic composition according to the invention is characterized in that it further comprises a step of mixing a volatile mixture of alkanes obtained by the process according to the invention with at least one non-volatile oil. [000205] For the purposes of the present invention, the term “non-volatile oil” means an oil having a flash point above 110°C measured according to the ATSM D93 standard. [000206] These oils can be of vegetable, mineral or synthetic origin. [000207] These non-volatile oils can be hydrocarbon, silicone, fluorinated or fluorosilicone oils. [000208] For the purposes of the present invention, the term “hydrocarbon oil” means an oil essentially consisting of carbon atoms, hydrogen atoms and possibly oxygen and / or nitrogen atoms. [000209] Among these hydrocarbon oils, mention may be made of linear or branched alkanes of mineral or synthetic origin such as linear or branched alkanes of 17 to 40 carbon atoms, (poly)esters and (poly)ethers, and in particular (poly)esters of C2-C24 acids (preferably C6-C20), triglycerides of C6-C20 fatty acids, vegetable oils, di-alkyl carbonates, branched and / or unsaturated fatty acids, branched and / or unsaturated fatty alcohols. [000210] Concerning non-volatile silicone oils, they are notably chosen from the group comprising phenylated silicone oils, non-volatile polydimethylsiloxanes, or derivatives of non-volatile polydimethylsiloxanes and their mixtures. [000211] In a particularly preferred embodiment, the process for preparing a cosmetic composition according to the invention is characterized in that the non-volatile oil is chosen from the group consisting of non-volatile linear or branched alkanes. [000212] Preferably, the non-volatile oil is chosen from the group consisting of linear or branched alkanes of 17 to 40 carbon atoms. [000213] Preferably, the non-volatile oils are of plant origin. [000214] In a preferred embodiment, the process for preparing a cosmetic composition according to the invention is characterized in that the non-volatile oil is a vegetable hydrocarbon oil. [000215] The vegetable hydrocarbon oils are in particular chosen from the group comprising wheat germ, sunflower, grape seed, sesame, coconut, apricot, castor, corn, avocado, soybean, shea, olive, sweet almond, cotton, palm, macadamia, rapeseed, jojoba, hazelnut, poppy, alfalfa, pumpkin, blackcurrant, squash, evening primrose, barley oils, and mixtures thereof. [000216] In one embodiment, the process for preparing a cosmetic composition according to the invention is characterized in that the mass percentage of the non-volatile oil is at least 5% relative to the total mass of the cosmetic composition. [000217] In one embodiment, the process for preparing a cosmetic composition according to the invention is characterized in that the mass percentage of the non-volatile oil is at least 10% relative to the total mass of the cosmetic composition. [000218] In one embodiment, the process for preparing a cosmetic composition according to the invention is characterized in that the mass percentage of the non-volatile oil is between 5% and 25% relative to the total mass of the cosmetic composition. [000219] In one embodiment, the process for preparing a cosmetic composition according to the invention is characterized in that the mass percentage of the non-volatile oil is between 5% and 15% relative to the total mass of the cosmetic composition. [000220] In one embodiment, the process for preparing a cosmetic composition according to the invention is characterized in that the mass percentage of the non-volatile oil is between 10% and 25% relative to the total mass of the cosmetic composition. [000221] In one embodiment, the process for preparing a cosmetic composition according to the invention is characterized in that it further comprises a step of mixture of a volatile mixture of alkanes obtained by the process according to the invention with at least one glossy oil. [000222] For the purposes of the present invention, the term "shiny oil" means an oil having intrinsic shine properties. "Shiny oils" are frequently used in cosmetics to ensure a "shiny effect" when applying cosmetic compositions to keratin materials, for example. [000223] In one embodiment, the process for preparing a cosmetic composition according to the invention is characterized in that the shiny oil is a non-volatile oil. [000224] In one embodiment, the process for preparing a cosmetic composition according to the invention is characterized in that the shiny oil is chosen from the group comprising: - polymers such as: polybutylenes, in particular POLYBUTENE® marketed or manufactured by the company ATAMAN, hydrogenated polyisobutylenes, polydecenes and hydrogenated polydecenes, polyfarnesenes, vinylpyrrolidone copolymers, in particular the vinylpyrrolidone / eicosene copolymer, ANTARON V 220 ® marketed or manufactured by the company ISP. - esters such as esters of linear fatty acids having a total number of carbons greater than 30, aromatic esters, esters of fatty alcohols or branched fatty acids having from 20 to 30 carbon atoms. - ester copolymers such as: dimer dilinoleyl dimer dilinoleate (LUSPLAN DD-DA5 ® and LUSPLAN DD-DA7 ®), dilinoleic acid / butanediol copolymer (VISCOPLAST 14436H®), dilinoleic acid / propanediol copolymer and mixtures thereof. [000225] Preferably, the process for preparing a cosmetic composition according to the invention is characterized in that the glossy oil is of plant origin. [000226] In one embodiment, the process for preparing a cosmetic composition according to the invention is characterized in that the mass percentage of the glossy oil is at least 2% relative to the total mass of the cosmetic composition. [000227] In one embodiment, the process for preparing a cosmetic composition according to the invention is characterized in that the mass percentage of the glossy oil is at least 5% relative to the total mass of the cosmetic composition. [000228] In one embodiment, the process for preparing a cosmetic composition according to the invention is characterized in that the mass percentage of the glossy oil is between 2% and 20% relative to the total mass of the cosmetic composition. [000229] In one embodiment, the process for preparing a cosmetic composition according to the invention is characterized in that the mass percentage of the shiny oil is between 5% and 15% relative to the total mass of the cosmetic composition. [000230] In one embodiment, the process for preparing a cosmetic composition according to the invention is characterized in that the mass percentage of the shiny oil is between 10% and 20% relative to the total mass of the cosmetic composition. [000231] In one embodiment, the process for preparing a cosmetic composition according to the invention is characterized in that the mass percentage of the shiny oil is between 2% and 10% relative to the total mass of the cosmetic composition. [000232] In one embodiment, the process for preparing a cosmetic composition according to the invention is characterized in that the mass percentage of the shiny oil is between 5% and 10% relative to the total mass of the cosmetic composition. [000233] In one embodiment, the process for preparing a cosmetic composition according to the invention is characterized in that it further comprises a step of mixing a volatile mixture of alkanes obtained by the process according to the invention with at least one pasty fatty substance. [000234] For the purposes of the present invention, the term "pasty fatty body" means a lipophilic fatty compound with a reversible solid / liquid state change, having at room temperature (25°C) a liquid fraction and a solid fraction. [000235] In other words, the melting temperature of the pasty fatty substance is less than or equal to 25°C. [000236] In one embodiment, the process for preparing a cosmetic composition according to the invention is characterized in that the pasty fatty substance is chosen from the group comprising synthetic pasty fatty substances, animal pasty fatty substances, vegetable pasty fatty substances and mixtures thereof. [000237] In one embodiment, the process for preparing a cosmetic composition according to the invention is characterized in that the pasty fatty substance is a synthetic pasty fatty substance chosen from the group comprising: polyol ethers, petroleum jelly, vinyl polymers, pentaerythritol esters, polyesters and mixtures thereof. [000238] In one embodiment, the process for preparing a cosmetic composition according to the invention is characterized in that the animal pasty fatty substance is lanolin. [000239] Preferably, the process for preparing a cosmetic composition according to the invention is characterized in that the pasty fatty substance is a vegetable pasty fatty substance. [000240] In one embodiment, the process for preparing a cosmetic composition according to the invention is characterized in that the vegetable pasty fatty body is chosen from the group including: vegetable butters (avocado butter, shea butter), fatty acid triglycerides and their derivatives, and their mixtures. [000241] In one embodiment, the process for preparing a cosmetic composition according to the invention is characterized in that the mass percentage of the pasty fatty substance is between 0% and 20% relative to the total mass of the cosmetic composition. [000242] In one embodiment, the process for preparing a cosmetic composition according to the invention is characterized in that the mass percentage of the pasty fatty substance is between 0% and 15% relative to the total mass of the cosmetic composition. [000243] In one embodiment, the process for preparing a cosmetic composition according to the invention is characterized in that the mass percentage of the pasty fatty substance is between 0% and 10% relative to the total mass of the cosmetic composition. [000244] In one embodiment, the process for preparing a cosmetic composition according to the invention is characterized in that the mass percentage of the pasty fatty substance is between 0% and 5% relative to the total mass of the cosmetic composition. [000245] In one embodiment, the process for preparing a cosmetic composition according to the invention is characterized in that it further comprises a step of mixing a volatile mixture of alkanes obtained by the process according to the invention with at least one gelling agent. [000246] For the purposes of the present invention, the term gelling agent means compounds which constitute excellent texturizing agents for balancing formulations in terms of smoothness and stickiness. [000247] Furthermore, certain glossy oils such as VISCOPLAST 14436H®, and the compounds marketed under the names LUSPLAN DD-DA5® and LUSPLAN DD-DA7® can also be used as gelling agents. [000248] In one embodiment, the process for preparing a cosmetic composition according to the invention is characterized in that the gelling agent is chosen from the group comprising: organic gelling agents, mineral gelling agents, polymeric gelling agents, and mixtures thereof. [000249] Preferably, the process for preparing a cosmetic composition according to the invention is characterized in that the gelling agent is of plant origin. [000250] In one embodiment, the process for preparing a cosmetic composition according to the invention is characterized in that the gelling agent is an organic gelling agent chosen from the group comprising: ethylcellulose and its derivatives, resins rosin derivatives, dextrin esters, fatty acid esters, and mixtures thereof. [000251] In one embodiment, the process for preparing a cosmetic composition according to the invention is characterized in that the gelling agent is a mineral gelling agent chosen from the group comprising: hectorite and its derivatives, pyrogenic silica and its derivatives, and mixtures thereof. [000252] In one embodiment, the process for preparing a cosmetic composition according to the invention is characterized in that the gelling agent is a polymeric gelling agent chosen from the group comprising: organopolysiloxanes and their derivatives, dimethicone copolymers and their derivatives, polystyrene / polyisoprene copolymers, polystyrene / polybutadiene copolymers, polystyrene / copoly(ethylene-propylene) copolymers, polystyrene / copoly(ethylene-butylene) copolymers, mixtures of copolymers in isododecane such as ethylene / propylene copolymer or butylene / ethylene / styrene copolymer, polyesters and their derivatives, polyamide resins, and mixtures thereof. [000253] In one embodiment, the process for preparing a cosmetic composition according to the invention is characterized in that the gelling agent is dextrin palmitate or one of its derivatives. [000254] In one embodiment, the process for preparing a cosmetic composition according to the invention is characterized in that the gelling agent is a modified hectorite of the BENTONE GEL ISD V® type or one of its equivalents. [000255] In one embodiment, the process for preparing a cosmetic composition according to the invention is characterized in that the gelling agent is a modified hectorite of the VEGELIGHT BENTONE SILK SB® type or one of its equivalents. [000256] In one embodiment, the process for preparing a cosmetic composition according to the invention is characterized in that the gelling agent is a modified hectorite of the disteardimonium hectorite type associated with triethyl citrate prepared in the volatile mixture of alkanes obtained in step 3 of the process according to the invention. [000257] In one embodiment, the process for preparing a cosmetic composition according to the invention is characterized in that the gelling agent is a mixture of copolymer in isododecane such as ethylene / propylene copolymer. [000258] In one embodiment, the process for preparing a cosmetic composition according to the invention is characterized in that the gelling agent is the combination of a dimethicone polymer and a mixture of alkanes marketed under the name VEGELIGHT SILK SI 118 ® by BIOSYNTHIS, or one of its equivalents. [000259] In one embodiment, the process for preparing a cosmetic composition according to the invention is characterized in that the mass percentage of the gelling agent is at least 5% relative to the total mass of the cosmetic composition. [000260] In one embodiment, the process for preparing a cosmetic composition according to the invention is characterized in that the mass percentage of the gelling agent is at least 15% relative to the total mass of the cosmetic composition. [000261] In one embodiment, the process for preparing a cosmetic composition according to the invention is characterized in that the mass percentage of the gelling agent is between 5% and 30% relative to the total mass of the cosmetic composition. [000262] In one embodiment, the process for preparing a cosmetic composition according to the invention is characterized in that the mass percentage of the gelling agent is between 5% and 20% relative to the total mass of the cosmetic composition. [000263] In one embodiment, the process for preparing a cosmetic composition according to the invention is characterized in that the mass percentage of the gelling agent is between 15% and 30% relative to the total mass of the cosmetic composition. [000264] In one embodiment, the process for preparing a cosmetic composition according to the invention is characterized in that the mass percentage of the gelling agent is between 5% and 15% relative to the total mass of the cosmetic composition. [000265] In one embodiment, the process for preparing a cosmetic composition according to the invention is characterized in that the mass percentage of the gelling agent is between 15% and 25% relative to the total mass of the cosmetic composition. [000266] In one embodiment, the process for preparing a cosmetic composition according to the invention is characterized in that the mass percentage of the gelling agent is between 20% and 30% relative to the total mass of the cosmetic composition. [000267] In one embodiment, the process for preparing a cosmetic composition according to the invention is characterized in that it further comprises a step of mixing a volatile mixture of alkanes obtained by the process according to the invention with at least one film-forming polymer. [000268] For the purposes of the present invention, the term film-forming polymer means a polymer capable of forming a macroscopically continuous film, in particular on the lips within the scope of our invention. [000269] In one embodiment, the process for preparing a cosmetic composition according to the invention is characterized in that the film-forming polymer is chosen from the group comprising: acrylic polymers, polyurethanes, polyesters, polyamides, silicone polymers. [000270] In one embodiment, the process for preparing a cosmetic composition according to the invention is characterized in that the film-forming polymer is trimethylsilloxysilicate marketed under the name TMS 803. [000271] In one embodiment, the process for preparing a cosmetic composition according to the invention is characterized in that the mass percentage of the film-forming polymer is at least 1% relative to the total mass of the cosmetic composition. [000272] In one embodiment, the process for preparing a cosmetic composition according to the invention is characterized in that the mass percentage of the film-forming polymer is at least 10% relative to the total mass of the cosmetic composition. [000273] In one embodiment, the process for preparing a cosmetic composition according to the invention is characterized in that the mass percentage of the film-forming polymer is between 1% and 25% relative to the total mass of the cosmetic composition. [000274] In one embodiment, the process for preparing a cosmetic composition according to the invention is characterized in that the mass percentage of the film-forming polymer is between 10% and 25% relative to the total mass of the cosmetic composition. [000275] In one embodiment, the process for preparing a cosmetic composition according to the invention is characterized in that the mass percentage of the film-forming polymer is between 1% and 10% relative to the total mass of the cosmetic composition. [000276] In one embodiment, the process for preparing a cosmetic composition according to the invention is characterized in that the mass percentage of the film-forming polymer is between 10% and 20% relative to the total mass of the cosmetic composition. [000277] In one embodiment, the process for preparing a cosmetic composition according to the invention is characterized in that it further comprises a step of mixing a volatile mixture of alkanes obtained by the process according to the invention with at least one wax. [000278] Waxes play an important role in the design of cosmetic products, particularly lipsticks, because they influence certain essential criteria such as the texture, appearance and / or solidity of the product. [000279] In the context of the present invention, the term "wax" means a lipophilic compound having a reversible solid / liquid state change. In other words, the compound is solid at room temperature (at 25°C) and has a melting point greater than or equal to [000280] Preferably, within the meaning of the present invention, the waxes used have a melting point greater than or equal to 50°C. [000281] In one embodiment, the process for preparing a cosmetic composition according to the invention is characterized in that the at least one wax is chosen from the group consisting of synthetic waxes, mineral waxes, vegetable waxes and animal waxes. [000282] In one embodiment, the process for preparing a cosmetic composition according to the invention is characterized in that the wax is a mineral wax or a synthetic wax chosen from the group comprising: microcrystalline waxes, paraffins, ozokerite, polyethylene waxes, silicone waxes, fluorinated waxes. [000283] By "vegetable wax" is meant a composition comprising at least one partially or completely hydrogenated oil. These vegetable waxes may comprise esters of fatty acids and fatty alcohols, and may further comprise fatty acids, free fatty alcohols, long-chain linear alkanes and / or unsaponifiables. [000284] Preferably, within the meaning of the present invention, the waxes used are vegetable waxes. [000285] In one embodiment, the process for preparing a cosmetic composition according to the invention is characterized in that the wax is a vegetable or animal wax chosen from the group comprising: lanolin wax, rice bran wax, carnauba wax, candelilla wax, berry wax, beeswax, sunflower wax, mimosa wax, jojoba wax, castor wax, olive wax. [000286] In one embodiment, the process for preparing a cosmetic composition according to the invention is characterized in that the mass percentage of the wax is at least 2% relative to the total mass of the cosmetic composition. [000287] In one embodiment, the process for preparing a cosmetic composition according to the invention is characterized in that the mass percentage of the wax is at least 5% relative to the total mass of the cosmetic composition. [000288] In one embodiment, the process for preparing a cosmetic composition according to the invention is characterized in that the mass percentage of the wax is between 2% and 20% relative to the total mass of the cosmetic composition. [000289] In one embodiment, the process for preparing a cosmetic composition according to the invention is characterized in that the mass percentage of the wax is between 5% and 15% relative to the total mass of the cosmetic composition. [000290] In one embodiment, the process for preparing a cosmetic composition according to the invention is characterized in that the mass percentage of the wax is between 2% and 10% relative to the total mass of the cosmetic composition. [000291] In one embodiment, the process for preparing a cosmetic composition according to the invention is characterized in that the mass percentage of the wax is between 5% and 10% relative to the total mass of the cosmetic composition. [000292] In one embodiment, the process for preparing a cosmetic composition according to the invention is characterized in that it further comprises a step of mixing a volatile mixture of alkanes obtained by the process according to the invention with at least one antioxidant. [000293] In one embodiment, the process for preparing a cosmetic composition according to the invention is characterized in that the antioxidant is chosen from the group comprising: phenolic antioxidants of the BHA, BHT, DBPC, gallate type, so-called natural antioxidants such as dl-alpha-tocopherol or its derivatives, plant extracts, dibasic lipopeptides such as lysine or arginine, and mixtures thereof. [000294] In one embodiment, the process for preparing a cosmetic composition according to the invention is characterized in that the mass percentage of the antioxidant is at least 0.01% relative to the total mass of the cosmetic composition. [000295] In one embodiment, the process for preparing a cosmetic composition according to the invention is characterized in that the mass percentage of the antioxidant is at least 0.1% relative to the total mass of the cosmetic composition. [000296] In one embodiment, the process for preparing a cosmetic composition according to the invention is characterized in that the mass percentage of the antioxidant is between 0.01% and 2% relative to the total mass of the cosmetic composition. [000297] In one embodiment, the process for preparing a cosmetic composition according to the invention is characterized in that the mass percentage of the antioxidant is between 0.01% and 1% relative to the total mass of the cosmetic composition. [000298] In one embodiment, the process for preparing a cosmetic composition according to the invention is characterized in that the mass percentage of the antioxidant is between 0.1% and 1% relative to the total mass of the cosmetic composition. [000299] In one embodiment, the process for preparing a cosmetic composition according to the invention is characterized in that the mass percentage of the anti- oxidant is between 0.01% and 0.1% relative to the total mass of the cosmetic composition. [000300] In one embodiment, the process for preparing a cosmetic composition according to the invention is characterized in that it further comprises a step of mixing a volatile mixture of alkanes obtained by the process according to the invention with at least one pigmentary part. [000301] This pigmentary part allows to obtain a coloring of the cosmetic composition. The pigments used are of synthetic, mineral or vegetable origin. Their dosage is also subtle. [000302] In one embodiment, the process for preparing a cosmetic composition according to the invention is characterized in that the pigmentary part is chosen from the group comprising: water-soluble dyes, liposoluble dyes, pigments, pearlescent agents, glitter and mixtures thereof. [000303] In one embodiment, the process for preparing a cosmetic composition according to the invention is characterized in that the pigmentary part is chosen from the group comprising: organic pigments such as fixed pigments or precipitated pigments, mineral pigments such as titanium dioxide or iron oxides, sodium aluminosilicate thiosulfates, chromium oxides, bismuth oxychloride, copper phthalocyanine, metal-free phthalocyanine, chlorinated copper phthalocyanine. [000304] Thus, the titanium oxide level determines the coverage and opacity of the film. [000305] The use of lakes or precipitated pigments determines the color and chrominance. [000306] By way of illustration, other types of pigments can be used such as titanium mica, borosilicates and their derivatives, mica, silica. [000307] Mineral pigments are used to nuance the shades while compounds such as bismuth oxychloride can be used to confer particular effects (metallic, shimmering effects, etc.). [000308] In one embodiment, the process for preparing a cosmetic composition according to the invention is characterized in that the pigmentary part comprises a synthetic colorant chosen from the group comprising: CI100006, CI12010, CI12085, CI12120, CI12370, CI12420, CI12490, CI14270, CI14700, CI14720, CI14815, CI15525, CI15580, CI15620, CI15630, CI15850, CI15865, CI15880, CI15980, CI15985, CI1035, CI16255, CI16290, CI17200, CI18050, CI45100, CI45220, CI45380, CI45430. [000309] In one embodiment, the process for preparing a cosmetic composition according to the invention is characterized in that the pigmentary part comprises a synthetic dye chosen from the group comprising: CI77499, CI77267, CI77268, CI77499 CI77266, CI50420, CI27755, CI28440, CI20470 and mixtures thereof. [000310] In one embodiment, the process for preparing a cosmetic composition according to the invention is characterized in that the pigmentary part comprises a dye of plant origin chosen from fruit and / or plant extracts containing dyes. [000311] In one embodiment, the process for preparing a cosmetic composition according to the invention is characterized in that the mass percentage of the pigmentary part is at least 0.01% relative to the total mass of the cosmetic composition. [000312] In one embodiment, the process for preparing a cosmetic composition according to the invention is characterized in that the mass percentage of the pigmentary part is at least 1% relative to the total mass of the cosmetic composition. [000313] In one embodiment, the process for preparing a cosmetic composition according to the invention is characterized in that the mass percentage of the pigmentary part is at least 5% relative to the total mass of the cosmetic composition. [000314] In one embodiment, the process for preparing a cosmetic composition according to the invention is characterized in that the mass percentage of the pigmentary part is between 0.01% and 20% relative to the total mass of the cosmetic composition. [000315] In one embodiment, the process for preparing a cosmetic composition according to the invention is characterized in that the mass percentage of the pigmentary part is between 1% and 20% relative to the total mass of the cosmetic composition. [000316] In one embodiment, the process for preparing a cosmetic composition according to the invention is characterized in that the mass percentage of the pigmentary part is between 5% and 20% relative to the total mass of the cosmetic composition. [000317] In one embodiment, the process for preparing a cosmetic composition according to the invention is characterized in that the mass percentage of the pigmentary part is between 1% and 15% relative to the total mass of the cosmetic composition. [000318] In one embodiment, the process for preparing a cosmetic composition according to the invention is characterized in that the mass percentage of the pigmentary part is between 5% and 15% relative to the total mass of the cosmetic composition. [000319] In one embodiment, the process for preparing a cosmetic composition according to the invention is characterized in that the mass percentage of the pigmentary part is between 0.01% and 5% relative to the total mass of the cosmetic composition. [000320] In one embodiment, the process for preparing a cosmetic composition according to the invention is characterized in that the mass percentage of the pigmentary part is between 5% and 10% relative to the total mass of the cosmetic composition. [000321] In one embodiment, the process for preparing a cosmetic composition according to the invention is characterized in that the mass percentage of the pigmentary part is between 10% and 15% relative to the total mass of the cosmetic composition. [000322] In one embodiment, the process for preparing a cosmetic composition according to the invention is characterized in that it further comprises a step of mixing a volatile mixture of alkanes obtained by the process according to the invention with at least one surfactant. [000323] For the purposes of the present invention, the term "surfactant" means a compound which modifies the surface tension between two surfaces, phases. Generally speaking, these compounds are amphiphilic molecules and make it possible to solubilize two immiscible phases of a composition. [000324] In one embodiment, the process for preparing a cosmetic composition according to the invention is characterized in that the at least one surfactant is chosen from the group comprising non-ionic, anionic and amphoteric surfactants. [000325] In one embodiment, the process for preparing a cosmetic composition according to the invention is characterized in that the at least one surfactant is a non-ionic surfactant. [000326] In one embodiment, the process for preparing a cosmetic composition according to the invention is characterized in that the at least one surfactant is chosen from the group of non-ionic surfactants consisting of: polyoxyalkylene alkyl ethers, glycerin alkyl ethers, glycerin fatty acid esters, polyglycerin fatty acid esters, sorbitan fatty acid esters, their derivatives, and their mixtures. [000327] In one embodiment, the process for preparing a cosmetic composition according to the invention is characterized in that the at least one surfactant is an anionic surfactant. [000328] In one embodiment, the process for preparing a cosmetic composition according to the invention is characterized in that the at least one surfactant is an anionic surfactant chosen from the group consisting of: alkyl phosphates, polyoxyalkylene alkyl ether phosphates, sulfonates, alkyl sulfates, polyaspartates, their derivatives and mixtures thereof. [000329] In one embodiment, the process for preparing a cosmetic composition according to the invention is characterized in that the at least one surfactant is an amphoteric surfactant. [000330] In one embodiment, the process for preparing a cosmetic composition according to the invention is characterized in that the mass percentage of the at least one surfactant is at least 0.1% relative to the total mass of the cosmetic composition. [000331] In one embodiment, the process for preparing a cosmetic composition according to the invention is characterized in that the mass percentage of the at least one surfactant is at least 5% relative to the total mass of the cosmetic composition. [000332] In one embodiment, the process for preparing a cosmetic composition according to the invention is characterized in that the mass percentage of the at least one surfactant is between 0.1% and 30% relative to the total mass of the cosmetic composition. [000333] In one embodiment, the process for preparing a cosmetic composition according to the invention is characterized in that the mass percentage of the at least one surfactant is between 5% and 15% relative to the total mass of the cosmetic composition. [000334] In one embodiment, the process for preparing a cosmetic composition according to the invention is characterized in that it further comprises a step of mixing a volatile mixture of alkanes obtained by the process according to the invention with at least one aqueous phase. [000335] In one embodiment, the process for preparing a cosmetic composition according to the invention is characterized in that the aqueous phase consists of water. [000336] In one embodiment, the process for preparing a cosmetic composition according to the invention is characterized in that the aqueous phase comprises water and at least one water-miscible organic solvent. [000337] In one embodiment, the process for preparing a cosmetic composition according to the invention is characterized in that the aqueous phase comprises at least one water-miscible organic solvent chosen from the group consisting of lower alcohols such as ethanol, isopropanol, butanol, isoamyl alcohol, glycols such as ethylene glycol, propylene glycol, 1,3-butylene glycol, ketones and short-chain aldehydes in C2 to C4. [000338] In one embodiment, the process for preparing a cosmetic composition according to the invention is characterized in that the mass percentage of the aqueous phase is between 1 and 95% relative to the total mass of the cosmetic composition. [000339] In one embodiment, the process for preparing a cosmetic composition according to the invention is characterized in that the mass percentage of the aqueous phase is between 5 and 80% relative to the total mass of the cosmetic composition. [000340] In one embodiment, the process for preparing a cosmetic composition according to the invention is characterized in that the mass percentage of the aqueous phase is between 5 and 60% relative to the total mass of the cosmetic composition. [000341] In one embodiment, the process for preparing a cosmetic composition according to the invention is characterized in that the mass percentage of the aqueous phase is between 1 and 50% relative to the total mass of the cosmetic composition. [000342] In one embodiment, the process for preparing a cosmetic composition according to the invention is characterized in that the mass percentage of the aqueous phase is between 1 and 30% relative to the total mass of the cosmetic composition. [000343] In one embodiment, the process for preparing a cosmetic composition according to the invention is characterized in that the mass percentage of the aqueous phase is between 10 and 40% relative to the total mass of the cosmetic composition. [000344] In one embodiment, the process for preparing a cosmetic composition according to the invention is characterized in that the mass percentage of the aqueous phase is between 1 and 20% relative to the total mass of the cosmetic composition. [000345] In one embodiment, the process for preparing a cosmetic composition according to the invention is characterized in that the cosmetic composition obtained has a naturalness index greater than or equal to 80% carbon 14 ( 14 C) determined according to one of the following standards ASTM D6866, EN 16640 or EN 16785-1. [000346] In one embodiment, the process for preparing a cosmetic composition according to the invention is characterized in that the cosmetic composition obtained has a naturalness index greater than or equal to 85% carbon 14 ( 14 C) determined according to one of the following standards ASTM D6866, EN 16640 or EN 16785-1. [000347] In one embodiment, the process for preparing a cosmetic composition according to the invention is characterized in that the cosmetic composition obtained has a naturalness index greater than or equal to 90% carbon 14 ( 14 C) determined according to one of the following standards ASTM D6866, EN 16640 or EN 16785-1. [000348] In one embodiment, the process for preparing a cosmetic composition according to the invention is characterized in that the cosmetic composition obtained has a naturalness index greater than or equal to 95% of carbon 14 ( 14 C) determined according to one of the following standards ASTM D6866, EN 16640 or EN 16785-1. [000349] In one embodiment, the process for preparing a cosmetic composition according to the invention is characterized in that at least 85% by mass of its ingredients is biosourced relative to the total mass of the composition. [000350] In one embodiment, the process for preparing a cosmetic composition according to the invention is characterized in that at least 50% by mass of the ingredients of the cosmetic composition obtained is of natural origin relative to the total mass of the composition. [000351] In one embodiment, the process for preparing a cosmetic composition according to the invention is characterized in that at least 75% by mass of the ingredients of the cosmetic composition obtained is of natural origin relative to the total mass of the composition. [000352] In one embodiment, the process for preparing a cosmetic composition according to the invention is characterized in that at least 90% by mass of the ingredients of the cosmetic composition obtained is of natural origin relative to the total mass of the composition. [000353] In one embodiment, the process for preparing a cosmetic composition according to the invention is characterized in that 50% by mass of the ingredients of the cosmetic composition obtained is of natural origin relative to the total mass of the composition. [000354] In one embodiment, the process for preparing a cosmetic composition according to the invention is characterized in that 75% by mass of the ingredients of the cosmetic composition obtained is of natural origin relative to the total mass of the composition. [000355] In one embodiment, the process for preparing a cosmetic composition according to the invention is characterized in that 90% by mass of the ingredients of the cosmetic composition obtained is of natural origin relative to the total mass of the composition. [000356] The invention also relates to the use of the volatile mixture of alkanes obtained by the process according to the invention for the preparation of a cosmetic composition for lipstick, long-lasting lipstick or lip gloss. [000357] For the purposes of the present invention, the term “long-lasting” lipstick, or also called “non-transfer” lipstick, means a lipstick that does not leave marks, is water-resistant and sometimes oil-resistant. [000358] Similarly, "lip gloss" or "lip gloss" refers to a makeup product that gives a shiny and / or wet appearance to the lips, and sometimes, colors or even glitters them. Some of these lip glosses are transparent and can be applied over a classic lipstick to add a shiny effect. [000359] Classically, according to the book Conception des produits cosmétiques : la formulation, by Anne-Marie PENSE-LHERITIER published in 2014 by LAVOISIER, the composition of a lipstick is based on a pair: Base or support Pigmentary part [000360] The base contains different types of ingredients selected essentially on their organoleptic properties: volatile solvents to facilitate application and hold; oils to provide slip and ease of application; waxes, to fix the consistency and hardness; fatty substances such as pasty fatty substances or gelling agents to adjust the smoothness and ease of use. [000361] Obtaining a lipstick is done by finding a subtle balance between these different ingredients. [000362] Various additives providing specific properties can be added to these ingredients: polymers, absorbent powders, stabilizing additives (antioxidants, preservatives, etc.), perfume and active ingredients where appropriate. [000363] In one embodiment, the cosmetic compositions for long-lasting lipstick, or lip glosses comprising the volatile mixture of alkanes obtained by the process according to the invention have excellent stability and remarkable cosmetic qualities such as ease of application, water resistance, good hold, more intense and luminous color. [000364] The invention also relates to the use of the volatile mixture of alkanes obtained by the process according to the invention for the preparation of a cosmetic makeup composition for the eyes. [000365] In one embodiment, the volatile mixture of alkanes obtained by the process according to the invention is used for the preparation of a cosmetic composition of mascara or eyeliner. [000366] Traditionally, according to the book Conception des produits cosmétiques : la formulation, by Anne-Marie PENSE-LHERITIER published in 2014 by LAVOISIER, there are mainly two types of mascara formulations: Continuous water-based mascaras are also called “water-based mascara”. Oil-based mascaras are also called "waterproof mascara" [000367] In one embodiment, the volatile mixture of alkanes obtained by the process according to the invention is used for the preparation of cosmetic compositions of mascaras with a continuous oily phase. [000368] Continuous oil-phase mascaras are mainly based on the use of wax or continuous oil-phase emulsion. The aim is to form a continuous film on the surface of the eyelash, a film that is perfectly water-resistant. [000369] To do this, the mascara composition comprises in particular a fatty phase and a pigmentary part and this composition may optionally comprise an aqueous phase. [000370] In one embodiment, the mascara composition comprising the volatile mixture of alkanes obtained by the process according to the invention comprises a mass percentage of less than or equal to 10% of water relative to the total mass of the composition. [000371] In a preferred embodiment, the mascara composition comprising the volatile mixture of alkanes obtained by the process according to the invention is free of an aqueous phase. [000372] The fatty phase includes in particular volatile solvents, oils, surfactants, waxes, gelling agents, film-forming polymers, and preservatives. [000373] The pigmentary part includes water-soluble dyes, fat-soluble dyes, pigments, pearlescent agents and glitter. [000374] Obtaining a mascara is done by finding a subtle balance between these different ingredients. [000375] Various additives providing specific properties can be added to these ingredients: polymers, absorbent powders, stabilizing additives such as antioxidants, perfume and active ingredients where appropriate. [000376] Concerning eyeliners, their composition is similar to that of the mascaras developed above. [000377] In one embodiment, the cosmetic compositions for the eyes, such as those of mascara or eyeliner, comprising the volatile mixture of alkanes obtained by the process according to the invention have excellent stability and remarkable cosmetic qualities such as ease of application, water resistance, good hold and more intense color. [000378] The invention also relates to the use of the volatile mixture of alkanes obtained by the process according to the invention for the preparation of a cosmetic composition applicable to the skin. [000379] In one embodiment, the volatile mixture of alkanes obtained by the process according to the invention is particularly used for the preparation of cosmetic compositions such as a makeup primer or base, a blush, an eyeshadow, a foundation or a makeup remover formulation. [000380] Foundation is a formulation intended to unify the skin and lightly color it. It must be applied in a uniform layer but also allow blending, on the face and part of the neck. [000381] Similarly, we understand by base, primer or makeup base a cosmetic composition which allows to fade the imperfections of the skin and prevents the makeup from settling in wrinkles, pores throughout the day. Thus, this formulation allows to perfect the skin before applying a foundation, a blush, etc. [000382] Blush, or commonly called “blush,” is a cosmetic formulation intended to mimic or reinforce a “pink cheek” appearance. [000383] Similarly, eye shadow or commonly called "eye-shadow" means cosmetic formulations applicable to the eyelid in order to highlight the eyes by creating color contrasts. [000384] By makeup remover formulation we mean a makeup remover oil but also a biphasic makeup remover formulation which allows the face to be cleaned of makeup while respecting the skin of its user. [000385] As stated above, these make-up removing formulations can be in the form of a make-up removing oil made up of oils and various fatty substances. [000386] They can also be presented in the form of a two-phase formulation comprising an aqueous phase and an oily phase. [000387] Conventionally, the volatile mixture of alkanes obtained by the process according to the invention is used for the preparation of cosmetic compositions applicable to the skin, in particular foundation and / or base compositions which can be formulated in a fluid or solid form of powder type, loose compact or cast. [000388] These compositions can in particular, independently of one another, be in an anhydrous form or in the form of an emulsion. [000389] These emulsions can be presented in different forms, namely in the form of an oil-in-water emulsion, water-in-oil but also in certain conditions in the form of multiple emulsion W / O / W (water / oil / water) or O / W / O (oil / water / oil) combining at least one aqueous phase and one fatty phase. [000390] In one embodiment, the volatile mixture of alkanes obtained by the process according to the invention is used for the preparation of a cosmetic composition applicable to the skin comprising at least one aqueous phase and one fatty phase. [000391] The aqueous phase consists essentially of water. [000392] The fatty phase contains different types of ingredients selected essentially on their organoleptic properties: volatile solvents to facilitate the application and hold of oils to give slip and ease of application to waxes, to fix the consistency and hardness of fatty substances such as pasty fatty substances or gelling agents to adjust the smoothness and ease of use. [000393] Generally, the volatile mixture of alkanes obtained by the process according to the invention is used for the preparation of a cosmetic composition applicable to the skin comprising a pigmentary part. [000394] Obtaining a satisfactory cosmetic composition applicable to the skin is achieved by seeking a subtle balance between these different ingredients. [000395] Different additives providing specific properties can be added to these ingredients: polymers, absorbent powders, stabilizing additives (antioxidants, preservatives, etc.), perfume and active ingredients where appropriate. [000396] In one embodiment, the cosmetic compositions applicable to the skin such as bases or primers, foundations or powders, comprising the volatile mixture of alkanes obtained by the process according to the invention have excellent stability and remarkable cosmetic properties such as ease of application, water resistance, good hold, more intense and luminous color. [000397] The invention also relates to the use of the volatile mixture of alkanes obtained by the process according to the invention for the preparation of a cosmetic composition for the treatment of keratin fibers, in particular hair. [000398] In one embodiment, the volatile mixture of alkanes obtained by the process according to the invention is used for the preparation of cosmetic compositions for the treatment of keratin fibers in the form of solution, dispersion, oil / water emulsion, water / oil emulsion, water / oil / water emulsion, powder, talc, capsules, sponge, mousse, lacquer and gel. [000399] In one embodiment, the volatile mixture of alkanes obtained by the process according to the invention is used for the preparation of cosmetic compositions for the treatment of keratin fibers such as hair toners, hair dyes, hair styling products, shampoos, hair conditioners, conditioners, conditioning shampoos, hair treatment products, hair sprays, hair masks, hair care products, hair treatment products, permanent wave fixing solutions, hair shaping products, shampoos for colored hair, hair fixatives, hair holding products, hair styling preparations, leave-in hair products, curling iron lotions, fixing mousses, hair gels, hair waxes or combinations thereof. [000400] In one embodiment, the cosmetic compositions for the treatment of keratin fibers, in particular hair, comprising the volatile mixture of alkanes obtained by the process according to the invention have excellent stability and remarkable cosmetic properties such as ease of application, good hold, luminous color and more intense shine. EXAMPLES: [000401] The following examples are given to illustrate the invention. [000402] Gas chromatography method used for the determination of purity [000403] The purity of the compounds was determined by gas chromatography (GC) using a GC FID 8860 apparatus (Agilent) equipped with a ZB5HT Inferno column (Phenomenex) with dimensions of 15m x 0.32mm x 0.10mm, a split injector heated to 325°C and an FID detector heated to 350°C. [000404] The sample to be analyzed was prepared by a standard pre-injection silylation method (1 pL) using the BSTFA / TMCS derivatization mixture (Sigma Aldrich). [000405] The injection was carried out between 300 and 330°C depending on the type of sample and was followed by a heating gradient between 100 and 400°C. [000406] Squalane was used as an internal standard for the analysis of Guerbet alcohols while 1-hexanol was used as an internal standard for the analysis of alkene mixtures and volatile alkane mixtures. [000407] Method for determining the iodine value [000408] The iodine number of the volatile mixtures of alkanes obtained by the process according to the invention was determined according to the NF EN ISO 3961 method. Example 1: Process for the preparation of a volatile mixture of 2,3,6-trimethylheptane and n-dodecane according to the invention [000409] Step 1: Synthesis of 2-isopropyl-5-methylhexan-l-ol from isoamyl alcohol (CAS 123-51-3) by a Guerbet synthesis [000410] Bio-sourced isoamyl alcohol (Sigma Aldrich) has a minimum mass purity of 85% in 3-methylbutanol. [000411] The synthesis is carried out under the following conditions: Reagents used: Table 1 Operating conditions: Table 2 Composition of the crude product obtained by the Guerbet synthesis (GC analysis): Table 3 [000412] Heavy products are in particular compounds resulting from a trimerization of the reactive alcohol. [000413] The crude product is purified by vacuum distillation. [000414] Topping allows the elimination of traces of isoamyl alcohol. [000415] Tailing then allows the elimination of heavy products. [000416] The Guerbet alcohol 2-isopropyl-5-methylhexan-l-ol obtained has a purity greater than 94% by CPG analysis. [000417] Step 2: [000418] 70 g of bio-sourced 1-dodecanol (purity 99%, BASF) are added to 30 g of Guerbet alcohol 2-isopropyl-5-methylhexan-l-ol to form a mixture of bio-sourced alcohols. [000419] Step 3: [000420] Dehydration of the alcohol mixture l-dodecanol / 2-isopropyl-5-methylhexan-1-ol [000421] A catalyst bed is placed at the mid-height of the reactor containing the alcohol mixture. A thermocouple is placed at the heart of this bed. The latter is held by a grid on which silica wool (VWR) is placed. Above the bed, silica wool is added to block the alumina catalyst bed (Johnson Matthey). [000422] The LHSV (Liquid Hourly Space Velocity) corresponds to the flow rate of alcohol passed through the reactor expressed in mL / min / mL of catalyst. [000423] The characteristic parameters of the continuous dehydration process are as follows: Table 4 [000424] The mixture of alkenes obtained is a liquid with a purity greater than 99.5% (GC analysis). [000425] Hydrogenation of the mixture of alkenes obtained during the dehydration reaction [000426] The hydrogenation reaction takes place in a batch reactor with a capacity of one liter. [000427] The mixture of alkenes (100 g) and a Nysosel type Raney nickel catalyst (BASF) (0.5 g) are introduced into the reactor at room temperature. The reactor is inerted with 3X5 bars of nitrogen and the temperature is raised to a temperature of 180°C. 5 bars of hydrogen are then introduced. After 2 hours, the temperature is raised to 200°C and the hydrogen pressure to 10 bars. The reaction is then continued for a further 3 hours. [000428] A volatile alkane mixture consisting of 2,3,6-trimethylheptane and n-dodecane is obtained. The composition of the volatile alkane mixture is 30% by mass of 2,3,6-trimethylheptane and 70% by mass of n-dodecane. [000429] The volatile mixture of alkanes has a purity of 99.7% (GC analysis), is odorless and the iodine value of the volatile mixture of alkanes is less than 1 g of iodine per 100 g of mixture. Example 2: Process for the preparation of a volatile mixture of 5-methylundecane and n-dodecane according to the invention [000430] Step 1: Synthesis of 2-butyloctan-l-ol from plant 1-hexanol by Guerbet synthesis [000431] Vegetable 1-hexanol (Sigma Aldrich) has a mass purity of 99%. [000432] The synthesis is carried out under the following conditions: Reagents used: Table 5 Operating conditions: Table 6 Composition of the crude product obtained by the Guerbet synthesis (analysis by GC): Table 7 [000433] Heavy products are in particular compounds resulting from a trimerization of 1-hexanol. [000434] The crude product is purified by vacuum distillation. [000435] Topping allows the elimination of traces of 1-hexanol. [000436] Tailing then allows the elimination of heavy products. [000437] The Guerbet alcohol 2-butyloctan-l-ol obtained has a purity greater than 94% by CPG analysis. [000438] Step 2: [000439] 50 g of bio-sourced 1-dodecanol (purity 99%, BASF) are added to 50 g of Guerbet alcohol 2-butyloctan-l-ol to form a mixture of bio-sourced alcohols. [000440] Step 3: [000441] Dehydration of the alcohol mixture l-dodecanol / 2-butyloctan-l-ol [000442] The dehydration reaction of the alcohol mixture l-dodecanol / 2-butyloctanol of step 2 is carried out by a method similar to that described in step 3 of example 1. [000443] The mixture of alkenes obtained is a liquid with a purity greater than 99.5% (GC analysis). [000444] Hydrogenation of the mixture of alkenes obtained during the dehydration reaction [000445] By a process similar to that described for step 3 of example 1, the mixture of alkenes (100 g) obtained by dehydration is hydrogenated in the presence of a Raney nickel catalyst of the Nysosel type (BASF) (0.5 g). [000446] A volatile alkane mixture consisting of 5-methylundecane and n-dodecane is obtained. The composition of the volatile alkane mixture is 50% by mass of 5-methylundecane and 50% by mass of n-dodecane. [000447] The volatile alkane mixture has a purity of 99.7% (GC analysis), is odorless and the iodine value of the volatile alkane mixture is less than 1 g of iodine per 100 g of mixture. Example 3: Process for the preparation of a volatile mixture of 2,3,6-trimethylheptane, 5-methylundecane and n-dodecane according to the invention [000448] Step 1: [000449] Guerbet alcohol 2-isopropyl-5-methylhexan-1-ol is obtained by the process described in Example 1 from isoamyl alcohol. [000450] Guerbet alcohol 2-butyloctan-1-ol is obtained by the process described in Example 2 from 1-hexanol. [000451] Step 2: [000452] 40 g of bio-sourced 1-dodecanol (purity 99%, BASF) are added to 30 g of 2-butyloctan-l-ol and 30 g of 2-isopropyl-5-methylhexan-l-ol to form a mixture of bio-sourced alcohols. [000453] Step 3: [000454] Dehydration of the alcohol mixture l-dodecanol / 2-butyloctan-l-ol / 2-isopropyl-5-methylhexan-l-ol [000455] The dehydration reaction of the alcohol mixture l-dodecanol / 2-butyloctan-l-ol / 2-isopropyl-5-methylhexan-l-ol of step 2 is carried out by a method similar to that described in step 3 of example 1. [000456] The mixture of alkenes obtained is a liquid with a purity greater than 99.5% (analysis by GC). [000457] Hydrogenation of the mixture of alkenes obtained during the dehydration reaction [000458] By a process similar to that described in step 3 of example 1, the mixture of alkenes (100 g) obtained by dehydration is hydrogenated in the presence of a Nysosel type Raney nickel catalyst (BASF) (0.5 g). [000459] A volatile alkane mixture consisting of 2,3,6-trimethylheptane, 5-methylundecane and n-dodecane is obtained. The composition of the volatile alkane mixture is 30% by mass of 2,3,6-trimethylheptane, 30% of 5-methylundecane and 40% by mass of n-dodecane. [000460] The volatile alkane mixture has a purity of 99.7% (GC analysis), is odorless and the iodine value of the volatile alkane mixture is less than 1 g of iodine per 100 g of mixture. Example 4: preparation of a long-lasting cosmetic lipstick composition. [000461] A long-lasting cosmetic lipstick composition is prepared from the volatile mixture of alkanes prepared in Example 1. [000462] The detailed composition of this long-lasting lipstick formulation is given in Table 8 below: Table 8 [000463] In order to prepare the long-lasting lipstick cosmetic composition, AEROSIL is dispersed in the volatile alkane mixture to form phase 1 of the lipstick formulation. [000464] Once phase 1 has dispersed, phase 2 is weighed in parallel in another container. The same operation is carried out for phase 3 and then phases 2 and 3 are mixed under magnetic stirring. [000465] The mixture of phases 2 and 3 is then placed on a heating plate until the RHEOPEARL KL2 is completely dispersed. The dispersed phase 1 is then added to the mixture of phases 2 and 3. [000466] Finally, phase 4 is heated alone on a hot plate until the wax has completely melted, then phase 4 is cooled in a cold water bath to 40°C and added to the mixture of dispersed phases 1, 2 and 3. [000467] This gives a homogeneous cosmetic composition of long-lasting lipstick. [000468] Example 5: Preparation of a cosmetic lip gloss composition [000469] A cosmetic lip gloss composition is prepared from a volatile mixture of alkanes consisting of 20% by mass of 2,3,6-trimethylheptane and 80% by mass of n-dodecane. This volatile mixture of alkanes is prepared by a process similar to that described in Example 1. [000470] The detailed composition of this lip gloss formulation is given in Table 10 below: Table 9 [000471] In order to prepare the cosmetic lip gloss composition, the pigments of phase 1 are mixed with octyldodecanol to obtain a paste. Then, the bentone gel obtained by combining the volatile mixture of alkanes obtained by the process according to the invention, a stearalkonium bentonite and triethyl citrate is added. Finally, all of phase 1 is dispersed. [000472] In this example, the volatile mixture of alkanes constitutes more than 80% by mass relative to the total mass of the bentone gel composition. [000473] In a second step, phase 2 is placed in a water bath at a temperature of 80°C until the waxes are in a liquid state. [000474] Phase 2 is allowed to cool to 40°C and then mixed with phase 1. [000475] The cosmetic composition of lip gloss has a satisfactory glossy effect. Example 6: preparation of a cosmetic mascara composition [000476] A cosmetic mascara composition is prepared from a volatile mixture of alkanes consisting of 20% by mass of 2,3,6-trimethylheptane and 80% by mass of n-dodecane. This volatile mixture of alkanes is prepared by a process similar to that described in Example 1. [000477] The detailed composition of this mascara formulation is given in Table 10 below: Table 10 [000478] In order to prepare the cosmetic mascara composition, phase 1 is weighed and heated to a maximum temperature of 35°C. [000479] Separately, phase 2 is weighed into another container and then phase 2 is heated to a temperature of 60°C. Then, phase 2 is added to phase 1, as well as phase 3 in a second step. [000480] Phase 4 is then added with vigorous magnetic stirring to obtain an emulsion. [000481] The texture of the mascara cosmetic composition is correct. Example 7: preparation of a cosmetic composition of an eyeliner [000482] A cosmetic composition of an eyeliner is prepared from a volatile mixture of alkanes consisting of 40% by mass of 2,3,6-trimethylheptane and 60% by mass of n-dodecane. This volatile mixture of alkanes is prepared by a process similar to that described in Example 1. [000483] The detailed composition of this formulation of an eyeliner is given in Table 11 below: Table 11 [000484] In order to prepare the cosmetic composition of an eyeliner of example 6, phase 1 is weighed and heated to a maximum temperature of 40°C. [000485] Separately, phase 2 is weighed into another container and then phase 2 is heated to a temperature of 60°C. Then, after cooling, phase 2 is added to phase 1, as well as phase 3 in a second step. [000486] Phase 4 is then added gradually with vigorous magnetic stirring to obtain an emulsion. [000487] Finally, the powders from phase 5 are added to the mixture. [000488] This cosmetic composition of an eyeliner has a naturalness index equal to 90% according to the ASTM D6866 standard. [000489] In other words, this cosmetic composition is made up of 90% ingredients of natural origin. Example 8: preparation of a cosmetic composition of a foundation [000490] A cosmetic composition of a foundation is prepared from a volatile mixture of alkanes consisting of 45% by mass of 2,3,6-trimethylheptane and 55% by mass of n-dodecane. This volatile mixture of alkanes is prepared by a process similar to that described in Example 1. [000491] The detailed composition of this cosmetic formulation of a foundation is given in Table 12 below: Table 12 [000492] In order to prepare the cosmetic composition of a foundation of example 7, phase 2 is dispersed in phase 1 with progressive stirring using a Turrax™ up to 12000 rpm for 2 minutes. Then, phase 3 is added to phases 1 and 2. Finally, phase 4 is added to the mixture of phases 1, 2 and 3. [000493] The mixture of phases 1, 2, 3 and 4 constitutes the oily phase of the cosmetic composition. [000494] Phases 5 and 6 (aqueous phase) are then added to the mixture of phases 1, 2, 3 and 4 to make the emulsion. The resulting mixture is gradually stirred with the Turrax™ up to 12000 rpm for 2 minutes. [000495] Finally, phase 7 is dispersed in the emulsion by progressive stirring with the Turrax™ up to 12000 rpm for 2 minutes. [000496] The cosmetic composition of a foundation has satisfactory drying time, water resistance and color. Example 9: Preparation of a cosmetic hair serum composition [000497] A cosmetic hair serum composition is prepared from a volatile mixture of alkanes consisting of 45% by mass of 2,3,6-trimethylheptane and 55% by mass of n-dodecane. This volatile mixture of alkanes is prepared by a process similar to that described in Example 1. [000498] The detailed composition of this cosmetic hair serum formulation is given in Table 13 below: Table 13 [000499] The ingredients of phase 1 are dispersed in Itra-Turrax™. [000500] Phases 1, 2 and 3 are then mixed to obtain a hair serum. [000501] Example 10: Biodegradability of a volatile mixture of alkanes prepared by the process according to the invention [000502] The biodegradability of a volatile mixture of alkanes consisting of 35% by mass of 2,3,6-trimethylheptane and 65% by mass of n-dodecane prepared by a process similar to that described in Example 1 was measured according to the OECD 301F method. [000503] The OECD 301F method allows the ease of biodegradation of a substance to be characterized by a manometric respirometry test. [000504] The volatile mixture of alkanes tested has a biodegradability of 58% according to the OECD 301F method.

Claims

DEMANDS

1. A process for preparing a volatile mixture of alkanes comprising the following steps: Step 1: the production of a Guerbet alcohol by a Guerbet synthesis from a bio-based linear or branched alcohol with a mass purity greater than or equal to 80%, Step 2: Add to the Guerbet alcohol obtained in step 1 at least one bio-based linear or branched alcohol to form a mixture of bio-based alcohols, Step 3: obtaining a volatile mixture of alkanes consisting of the branched alkane from the Guerbet alcohol and at least one alkane from the at least one bio-based alcohol added in step 2 by a dehydration reaction followed by a hydrogenation reaction of the mixture of bio-based alcohols formed in step 2.

2. A process according to claim 1, characterized in that the bio-based linear or branched alcohol has a mass purity greater than or equal to 80%.

3. A process according to any one of the preceding claims, characterized in that step 1 is carried out from a bio-based linear or branched alcohol in C< 10.

4. A process according to any one of the preceding claims, characterized in that step 1 is carried out using isoamyl alcohol.

5. A process according to any one of the preceding claims, characterized in that the alcohol used in step 1 and the alcohol added to the Guerbet alcohol in step 2 are of vegetable origin.

6. A process according to any one of the preceding claims, characterized in that at least one alcohol added to the Guerbet alcohol in step 2 is a linear or branched bio-based alcohol in C> 10.

7. A process according to claim 6, characterized in that at least one bio-based linear or branched alcohol in C>10 is a linear alcohol selected from the group consisting of n-decanol, n-dodecanol and n-tetradecanol.

8. A process according to any one of the preceding claims, characterized in that the volatile mixture of alkanes obtained in step 3 contains at least 20% by mass of the branched alkane from Guerbet alcohol and at least 20% by mass of at least one alkane from at least one bio-based alcohol added in step 2, relative to the total mass of the volatile mixture of alkanes.

9. A process according to any one of the preceding claims, characterized in that the volatile mixture of alkanes obtained in step 3 contains 20 to 80% by mass of 2,3,6-trimethylheptane and 20 to 80% by mass of at least one alkane linear chosen from the group composed of n-decane, n-dodecane and n-tetradecane, relative to the total mass of the volatile mixture of alkanes.

10. A process according to any one of the preceding claims, characterized in that the volatile mixture of alkanes obtained in step 3 contains 20 to 80% by mass of 2,3,6-trimethylheptane and 20 to 80% by mass of n-dodecane relative to the total mass of the volatile mixture of alkanes.

11. A process according to any one of the preceding claims, characterized in that the volatile mixture of alkanes obtained in step 3 has a flash point below 55°C according to ASTM D93. [0001] A process according to any one of the preceding claims, characterized in that the organic carbon present in the volatile mixture of alkanes obtained in step 3 has ratios 14 C / 12 Neck 14 C / 13determined by radiocarbon analysis according to one of the following standards ASTM D6866, EN 16640 or EN 16785-1 which correspond to the ratios of live plant products.

12. A process according to any one of the preceding claims, characterized in that the volatile mixture of alkanes obtained in step 3 exhibits a biodegradability of at least 50% according to OECD method 301F.

13. A process for preparing a cosmetic composition characterized in that it comprises a step of mixing the volatile mixture of alkanes obtained by a process according to any one of claims 1 to 13 with at least one compound selected from non-volatile oils, shiny oils, pasty fats, gelling agents, film-forming polymers, waxes, antioxidants, pigments, colorants, surfactants, an aqueous phase, and mixtures thereof.

14. A method for preparing a cosmetic composition according to claim 14 characterized in that the mass percentage of the volatile mixture of alkanes is greater than or equal to 5% relative to the total mass of the composition.

15. A method for preparing a cosmetic composition according to any one of claims 14 to 15, characterized in that the cosmetic composition has a percentage greater than or equal to 80% of carbon 14 ( 14 C) determined according to one of the following standards ASTM D6866, EN 16640 or EN 16785-1.

16. Use of the volatile mixture of alkanes obtained by the process according to any one of claims 1 to 13, for the preparation of a cosmetic composition for lipstick, long-lasting lipstick or lip gloss.

17. Use of the volatile mixture of alkanes obtained by the process according to any one of claims 1 to 13, for the preparation of a cosmetic eye makeup composition.

18. Use of the volatile mixture of alkanes obtained by the process according to any one of claims 1 to 13, for the preparation of a cosmetic composition applicable to the skin.

19. Use of the volatile mixture of alkanes obtained by the process according to any one of claims 1 to 20, for the preparation of a cosmetic composition for the treatment of keratin fibers.

Images