Cosmetic compositions comprising a DHA-derived polymer, a process for applying this polymer, and a synthesis process

Abstract

Cosmetic compositions comprising a DHA-derived polymer, a method for applying this polymer, and a synthesis method. The present invention relates to the use in cosmetics of a polymer obtained from 1,3-dihydroxyacetone (DHA). The invention also relates to a method for synthesizing this copolymer and to a monomer used as a reagent in this method. Finally, the invention relates to a method for applying this polymer to the skin. Figure for the abstract: Fig. 1.

Description

Title of the invention: Cosmetic compositions comprising a DHA-derived polymer, a method for applying this polymer, and a synthesis method technical field

[0001] The present invention relates to a cosmetic composition comprising a polymer obtained from 1,3-dihydroxyacetone (DHA). The invention also relates to a method for synthesizing this polymer and to a monomer used for the synthesis of the polymer. Finally, the invention relates to a method for applying this polymer to the skin, hair, or nails. Previous art

[0002] Polymers used in cosmetic products are often derived from synthetic raw materials. It is therefore desirable to have polymers synthesized from bio-based compounds.

[0003] Polymers formulated in cosmetics fulfill very diverse functions and can in particular serve as film-forming agents, thickeners, surfactants or emollients.

[0004] The need therefore remains to synthesize new bio-based polymers that can be formulated in a cosmetic product, and which in particular have film-forming properties. Description of the invention

[0005] The present invention meets this need by proposing a cosmetic composition comprising a polymer obtained from 1,3-dihydroxyacetone (DHA), a bio-based compound which is produced on a large scale by moderate oxidation of glycerol, and which is also a by-product of the mass production of biofuels.

[0006] The inventors have indeed found, surprisingly, that it is possible to synthesize a polymer with cosmetic properties from DHA. The polymer can be soluble or dispersible in cosmetic solvents and can advantageously be endowed with film-forming properties on keratinous materials.

[0007] Furthermore, the inventors have developed a process for synthesizing this polymer from a particular monomer, which can be copolymerized with comonomers whose intrinsic properties allow the cosmetic properties of the copolymer thus synthesized to be modulated. Brief description of the drawings

[0008] [Fig.1] Fig.1 represents the tensile curve of a copolymer according to the invention in the form of a film. Description of the implementation methods

[0009] A first object of the invention therefore relates to a cosmetic composition comprising a polymer obtained from 1,3-dihydroxyacetone, and at least one cosmetically acceptable ingredient.

[0010] In a particular embodiment, the polymer bears a 3-acyloxy-2-oxopropyl side group. "Acyloxy" is understood to mean a group of formula RCOO, in which R comprises oxygen, carbon, hydrogen, and nitrogen atoms. R is preferably an alkyl group having from 1 to 6 carbon atoms.

[0011] According to one embodiment, the polymer can be obtained from a monomer bearing a 3-hydroxy-2-oxopropyl group, the hydroxy function being able to be protected by esterification with an anhydride.

[0012] A particular polymer of the invention bearing a 3-acyloxy-2-oxopropyl side group can be selected from poly(vinylpyrrolidone) and vinylpyrrolidone copolymers, poly(vinyl acetate), polyvinyl alcohols, poly(N-vinyl caprolactam), polyamides, poly(hydroxyurethane), polyethers, silicone polymers, acrylic polymers, acrylate / octylacrylamide copolymers and polysaccharides.

[0013] In a particular case, the polymer is a (meth)acrylic polymer bearing a 3-acyloxy-2-oxopropyl side group.

[0014] According to one embodiment, the polymer can be obtained from a monomer bearing a 3-acyloxy-2-oxopropyl or 3-hydroxy-2-oxopropyl group. The monomer can be selected from (meth)acrylate monomers, styrenic monomers, and acrylamide monomers.

[0015] Thus the polymer can be a copolymer comprising at least one first formula repeating motif (Al)

[0016] [Chem.l] (Al)

[0017] in which Ri represents H or CH3, and R2 represents a saturated or unsaturated, linear or branched alkyl group having from 1 to 6 carbon atoms, or a -CH2=CH-R group, R representing an alkyl group having from 1 to 4 carbon atoms,

[0018] at least a second repeating unit, different from the first repeating unit.

[0019] The R2 group represents, for example, an alkyl group having from 1 to 3 carbon atoms.

[0020] In a particular embodiment, Riet R2 each represent a methyl group. The monomer with formula (Al) is in this case 3-acetoxy-2-oxopropyl methacrylate.

[0021] A spacer group -X- can be inserted between the -COO-CH2- group and the ketone function, with -X- being a linear, branched, cycloaliphatic or aromatic aliphatic chain, bearing heteroatoms.

[0022] The copolymer may further comprise at least one second repeating unit derived from a monomer selected from (meth)acrylic monomers and their esters, (meth)acrylamides monomers, and styrenic monomers. In one embodiment, the second repeating unit has the formula (Bl)

[0023] [Chem.2] (Bl)

[0024] in which R3 represents H or CH3 and R4 represents H or an alkyl group, linear or branched, saturated or unsaturated, having from 1 to 20 carbon atoms, for example a saturated linear alkyl group having from 4 to 18 carbon atoms.

[0025] In a particular embodiment, R3 represents H or methyl, and R4 represents H, methyl, butyl, octyl or stearyl.

[0026] A particular copolymer comprises at least three repeating motifs (Bl), different from each other, the first being such that R3 represents methyl and R4 represents methyl, the second being such that R3 represents H and R4 represents butyl, and the third being such that R3 represents H and R4 represents H. In this case, the copolymer is likely to be obtained from methyl methacrylate, butyl acrylate and acrylic acid.

[0027] The cosmetic composition of the invention may include at least one cosmetically acceptable solvent. According to a particular embodiment, this solvent is different from butyl acetate and ethyl lactate. The polymer can be advantageously solubilized or dispersed in this solvent.

[0028] A cosmetically acceptable solvent is understood to be an organic compound, advantageously liquid at room temperature, in which the polymer of the invention is at least partially soluble.

[0029] In particular, solvents may be cited as methyl oleate, dimethyl adipate, diethyl adipate, diisopropyl adipate, diisopropyl sebacate, butyl acetate, ethanol, isopropylidene glycerol, dimethyl isosorbide, neopentyl glycol dihepatanoate, esters of capric acid and caprylic acid with fatty alcohols, vegetable oils, volatile alkanes, tocopherol, and hydrophobic liquid UV filters such as ethylhexyl salicylate.

[0030] The composition according to the invention may include at least one gelling agent capable of gelling the solvent or mixture of solvents in which the polymer according to the invention has been solubilized or dispersed. The solvent or mixture of solvents is preferably chosen from oils, and the gelling agent is preferably a lipophilic gelling agent.

[0031] Said lipophilic gelling agent may advantageously be chosen from natural or synthetic clays such as hectorites and montmorillonites, and for example a hectorite modified with a quaternary alkylammonium chloride, such as disteardimonium hectorite in which the ammonium comprises two methyls and two stearyls; modified natural micas such as aluminum, magnesium and potassium fluorosilicate; esters of dextrin and fatty acids such as dextrin palmitate or dextrin myristate; C8-C30 fatty acid triesters and mono- or polyglyceryl such as glyceryl tri(hydroxystearate) (INCI name: Trihydroxystearin).

[0032] The cosmetic composition may include at least one pigment and / or at least one colorant.

[0033] The pigment can be selected from mineral pigments, organic pigments, pearlescent pigments, and mixtures thereof. Mineral pigments can be selected from iron oxides, in particular black, yellow, red, and brown iron oxides; manganese violet; ultramarine blue; chromium oxides, in particular hydrated chromium oxide, ferric blue, carbon black, and mixtures thereof.

[0034] Among the organic pigments, we can mention in particular the lakes obtained from dyes such as D&C Black No. 2, FD&C Blue No. 1, FD&C Green No. 3, D&C Green No. 5, D&C Orange No. 4, D&C Orange No. 5, D&C orange No. 10, D&C No. red 3, D&C Red No. 6, D&C Red No. 7, D&C red No. 9, D&C red No. 13, D&C red No. 19, D&C Red No. 21, D&C Red No. 22, D&C Red No. 27, D&C Red No. 28, D&C Red No. 30, D&C Red No. 33, D&C Red No. 36, FD&C Red No. 40, FD&C Yellow No. 5, FD&C Yellow No. 6, D&C Yellow No. 10 and cochineal carmine.

[0035] Pearlescent pigments are for example chosen from mica coated with titanium oxide, mica-titanium coated with iron oxide, mica-titanium coated with ferric blue, mica-titanium coated with chromium oxide, mica-titanium coated with an organic pigment as described above, as well as pigments based on bismuth oxychloride.

[0036] The composition of the invention may include any additive commonly used in cosmetics chosen from water, antioxidants, surfactants, aqueous gelling agents, thickeners, waxes, powder fillers whose particle shape (platelet, spherical or oblong) improves the feel upon application or the matte finish, preservatives, perfumes and cosmetic active agents.

[0037] Ingredients in powder form, particularly pigments and fillers, can be surface-treated with hydrophilic or hydrophobic agents to improve their dispersion within the composition. Examples of such treatments include hydrophobic surface treatments such as dextrin and fatty acid esters or acylated amino acids.

[0038] The cosmetic composition of the invention may be anhydrous or comprise water.

[0039] According to a first embodiment, the composition of the invention is an anhydrous product comprising at least one solvent selected from oils, in which the polymer is solubilized or dispersed.

[0040] According to another particular embodiment, the composition of the invention is a water-in-oil emulsion or an oil-in-water emulsion.

[0041] According to a particular method, the composition is in the form of a stick or a pencil. It may also be presented in a pot or a cup, applicable by finger, brush, sponge or with an applicator, to keratinous materials.

[0042] The cosmetic composition may be a perfume, a skincare product, or a makeup product, for the skin, eyelids, eyebrows, eyelashes, lips, hair or nails.

[0043] This will include, for example, a complexion corrector, an under-eye concealer, an eyeshadow, a lipstick.

[0044] The composition of the invention may also be a rinsed or non-rinsed hair product, such as a shampoo, conditioner or conditioning cream.

[0045] Finally, the composition of the invention may be a skincare product, for example a fluid or thick cream for the care of facial or lip skin.

[0046] A second object of the invention relates to a cosmetic process for applying to keratinous materials such as skin, eyelids, eyebrows, eyelashes, lips, nails or hair, a polymer obtained from 1,3- dihydroxyacetone or a cosmetic composition as described above. The polymer may conform to one of the polymers described above. The cosmetic process may be a skincare or makeup process.

[0047] According to said process, the polymer of the invention allows the formation of a film on the skin whose elasticity and resistance to wear related to skin movements makes it possible to improve the hold of the composition in which it is incorporated without loss of comfort.

[0048] The third object of the present invention relates to a process for synthesizing a polymer from a monomer, itself obtained from DHA. In a particular embodiment, the DHA is chemically modified by a series of protection-monomerization-deprotection followed by a protection-deprotection. For example, the ketone function of the DHA is protected by acetalization according to a method known to those skilled in the art, and then the protected DHA is grafted onto a monomer (or "monomerized"), for example by reacting an acyl function on a vinyl monomer with one of the two alcohol functions of the protected DHA.

[0049] The process for synthesizing a polymer of the invention may include a step i) of polymerizing a monomer of formula (I)

[0050] [Chem 3]

[0051] CH 2 =CR 4 -COO-CH 2 -C(OR a )(OR b )-CH 2 OR s (I) in which R4 represents H or CH3; R5 represents H or -OCR, R being a saturated or unsaturated, linear or branched alkyl group having from 1 to 6 carbon atoms; Ra and Rb each independently represent an alkyl group having from 1 to 3 carbon atoms, or Ra and Rb are linked to form a divalent hydrocarbon group comprising 2 or 3 carbon atoms,

[0052] to obtain an intermediate polymer bearing acetal functions -CH(ORa)(ORb)-, step i) being followed by a step ii) of transformation of the acetal functions of the intermediate polymer into ketone functions.

[0053] The monomer (I) can thus be prepared from 1,3-dihydroxyacetone in a step prior to step i) according to a process known to the person skilled in the art.

[0054] It may be necessary to protect the ketone function of 1,3-dihydroxyacetone before grafting it to a monomer. Thus, DHA can be reacted at room temperature with 2,2-dimethoxypropane in an alcoholic medium under acid catalysis. Acid catalysis can be provided by p-toluenesulfonic acid or an acid ion-exchange resin. Once the reaction is complete, the mixture reaction is advantageously filtered and then the solvent evaporated to obtain 2,2-dimethoxypropane-l,3-diol (protected DHA).

[0055] DHA can be grafted onto a monomer or "monomerized" by reacting, for example, a monomer precursor with an acyl group, such as an acyl chloride or an acid anhydride, with one of the two alcohol groups of DHA. For example, 2,2-dimethoxypropane-1,3-diol is reacted with methacrylic anhydride at room temperature, in the solvent phase, to obtain a monomer of formula (I).

[0056] In a first embodiment of the process of the invention, the monomer (I), where R2 represents H, is polymerized to obtain an intermediate polymer having side groups bearing a hydroxyl group and a protected ketone function. This hydroxyl group can then be protected, for example by esterification, before deprotecting the ketone function to obtain the final polymer. In this first embodiment, the monomer of formula (I) can be 3-hydroxy-2,2-dimethyloxypropyl (meth)acrylate.

[0057] In a second embodiment of the process of the invention, the monomer (I), such that R2 represents -COR, is polymerized to obtain an intermediate polymer having side groups bearing a -COR group. The acetal functions are then hydrolyzed to ketone functions to obtain the final polymer. In this second embodiment, the monomer of formula (I) can be 3-acyloxy-2,2-dimethyloxypropyl (meth)acrylate.

[0058] In step i), the monomer of formula (I) can be copolymerized with at least one comonomer, preferably a (meth)acrylic comonomer.

[0059] The (meth)acrylic comonomer can be chosen from methyl methacrylate, butyl acrylate and acrylic acid.

[0060] In one embodiment, the synthesis process uses at least two, or even at least three, (meth)acrylic comonomers. The proportion between the comonomers can advantageously be adjusted so that the glass transition temperature of the polymer is less than or equal to 30°C, preferably less than or equal to 0°C.

[0061] Step i) of copolymerization can be carried out by radical initiation, in a solvated or unsolvated medium, in the presence of a radical initiator. The polymer resulting from this reaction is purified by precipitation and dried at room temperature, then stored at 4°C before being used in a formulation.

[0062] A fourth object of the present invention relates to a chemical compound which can be used as a monomer in a polymerization process, in particular in the synthesis process described above.

[0063] This monomer has the formula (I)

[0064] [Chem 4] CH2=CR4-COO-CH2-C(ORa)(ORb)-CH2OR5 (I)

[0065] in which R4 represents H or CH3; R5 represents -OCR, R being a saturated or unsaturated, linear or branched alkyl group having from 1 to 6 carbon atoms; Ra and Rb each independently represent an alkyl group having from 1 to 3 carbon atoms, or Ra and Rb are linked to form a divalent hydrocarbon group comprising 2 or 3 carbon atoms.

[0066] The invention is illustrated by the following examples. Unless otherwise stated, the pressure is equal to atmospheric pressure and the temperature is between 20°C and 25°C.

[0067] Example 1: preparation of a monomer according to the invention We have completed the following series of steps.

[0068] 1. Protection by ketolization of the ketone of 1,3-dihydroxyacetone: In a suitably sized reaction flask, 1 mol eq. of DHA (or 0.5 mol eq. of DHA dimer) and 1.1 mol eq. of 2,2-dimethoxypropane are introduced into 25 mol eq. of MeOH under magnetic stirring. After the DHA is suspended in the medium, 0.002 mol eq. of p-toluenesulfonic acid is added, and the reaction is allowed to proceed under stirring for 24 h at room temperature. Alternatively, the synthesis was also successful using 0.002 mass eq. of an acid ion exchange resin (Amberlyst® 15) instead of p-toluenesulfonic acid. After 24 h of reaction, the mixture is neutralized by the addition of 0.01 mol eq. of anhydrous sodium carbonate or 0.01 eq. mass of a basic ion exchange resin (Amberlyst® 21 or 26). In the case of catalysis by acid ion exchange resin, the medium is not neutralized.The reaction mixture is then filtered and the solvent from the filtrate is evaporated under secondary vacuum with magnetic stirring; finally, the product is recrystallized in diethyl ether to obtain white crystals of 2,2-dimethoxypropane-1,3-diol (40-65%).

[0069] 2, Monomerization of 2,2-dimethoxypropane-L3-diol: In a suitably sized reaction flask, 1 mol eq. of 2,2-dimethoxypropane-1,3-diol is dissolved in 20 mol eq. of acetonitrile and 1.1 mol eq. of pyridine (or triethylamine) under magnetic stirring at room temperature. Once the solid has dissolved, 1 mol eq. of methacrylic anhydride is added dropwise to the reaction mixture, which is kept under stirring. After 16 hours of reaction, 2 mol eq. of sodium carbonate as a saturated aqueous solution are added to the reaction mixture, which is kept under stirring for 4 hours. The mixture is then filtered, and the solvent in the filtrate is evaporated under secondary vacuum. The resulting colored, viscous liquid is solubilized in a minimal amount of cyclohexane and then extracted. The aqueous phase is collected, saturated with sodium chloride under magnetic stirring at room temperature, and then extracted with an appropriate volume of ethyl acetate. The resulting organic phase is collected, dried over magnesium sulfate, and the solvent evaporated under secondary vacuum. The product obtained consists predominantly of 3-hydroxy-2,2-dimethoxypropyl methacrylate, with a yield of 65-75%.

[0070] 3. Protection of the hydroxyl group of 3-hydroxy-2,2-dimethoxypropyl methacrylate: In a suitably sized reaction flask, the following are sequentially introduced under magnetic stirring at room temperature: 1 mol eq. of 3-hydroxy-2,2-dimethoxypropyl methacrylate, 20 mol eq. of acetonitrile, 1.1 mol eq. of pyridine, and 2 mol eq. of acetic anhydride. The reaction is allowed to proceed under stirring for 16 h, after which 4 mol eq. of sodium carbonate are added as a saturated aqueous solution to the reaction mixture, which is then stirred for an additional 4 h. The mixture is then filtered, and the solvent in the filtrate is evaporated under secondary vacuum. The resulting colored liquid is dissolved in an appropriate volume of saturated aqueous sodium chloride solution and then extracted with an appropriate volume of ethyl acetate. The organic phase thus formed is collected, dried over magnesium sulfate, and the solvent is evaporated under secondary vacuum.The product obtained is predominantly composed of 3-acetoxy-2,2-dimethoxypropyl methacrylate with a yield of 85-95%.

[0071] 4. Deprotection of the ketone function of 3-acetoxy-2,2-dimethoxypropyl methacrylate: In a suitably sized reaction flask, the following are introduced sequentially under magnetic stirring at room temperature: 1 mol eq. of 3-acetoxy-2,2-dimethoxypropyl methacrylate, 80 mol eq. of acetonitrile, and 5 mol eq. of deionized water. 0.2 mol eq. of trifluoromethanesulfonic acid is then added dropwise, and the reaction is maintained under stirring for 15 minutes. After 15 minutes, the acid is neutralized by the addition of 1 mol eq. of sodium carbonate as a saturated aqueous solution, which is maintained under stirring for an additional 1 hour. The mixture is then filtered, and the solvent in the filtrate is evaporated under secondary vacuum. The resulting colored liquid is dissolved in an adequate volume of saturated aqueous sodium chloride solution and then extracted with an adequate volume of ethyl acetate. The organic phase thus formed is recovered, dried over magnesium sulfate, and then the solvent is evaporated under secondary vacuum.The product obtained is predominantly composed of 3-acetoxy-2-oxopropyl methacrylate with a yield of 85-95%.

[0072] Example 2: preparation of a copolymer according to the invention

[0073] A copolymer was prepared from a mixture of 3-acetoxy-2-oxopropyl methacrylate obtained according to Example 1 and butyl acetate in a molar ratio of 10 / 90. In a suitably sized reaction flask, 9 eq. of n-butyl acrylate and a sufficient quantity of toluene to achieve a final dry extract of 25 wt. are introduced under magnetic stirring at room temperature. The reaction mixture is heated to 40°C, and then 1 mol. eq. of 3-acetoxy-2-oxopropyl methacrylate and 0.1 mol. eq. of 2,2'-azobis(4-methoxy-2,4-dimethylvaleronitrile) are added gradually over 4 h and 6 h, respectively. The mixture is left under magnetic stirring at 40°C for a total of 18 h, including the time for the gradual addition of the two aforementioned reagents. After 18 h of reaction, the resulting viscous mixture is purified by precipitation in methanol at -50°C. The resulting precipitate is then filtered, collected, and dried under secondary vacuum. The purity of the copolymer obtained is controlled by NMR spectroscopy, and can be improved if it is not satisfactory by re-solubilizing 1 eq.mass of copolymer in 3 mass eq. of acetone and repeating the sequence of operations above. The final product is a white film-forming solid which is stored at +4°C before formulation.

[0074] Example 3: preparation of a copolymer according to the invention

[0075] A copolymer was prepared according to the invention by carrying out the following sequence of steps:

[0076] First step: polymerization A copolymer was prepared from a mixture of 3-acetoxy-2,2-dimethoxypropyl methacrylate obtained according to example 1 and butyl acetate in a molar ratio of 10 / 90. In a suitably sized reaction flask, 9 eq. of n-butyl acrylate and a sufficient quantity of toluene to achieve a final dry extract of 25 wt. are introduced under magnetic stirring at room temperature. The reaction mixture is heated to 40°C, and then 1 mol. eq. of 3-acetoxy-2,2-dimethoxypropyl methacrylate and 0.1 mol. eq. of 2,2'-azobis(4-methoxy-2,4-dimethylvaleronitrile) are added gradually over 4 h and 6 h, respectively. The mixture is left under magnetic stirring at 40°C for a total of 18 h, including the time for the gradual addition of the two aforementioned reagents. After 18 h of reaction, the resulting viscous mixture is purified by precipitation in methanol at -50°C. The resulting precipitate is then filtered, collected, and dried under secondary vacuum. The purity of the resulting copolymer is checked by NMR spectroscopy. It can be improved by re-solubilizing 1 mass eq. of copolymer in 3 mass eq. of acetone and repeating the sequence of operations above. The final product is a white, film-forming solid that is stored at +4°C before formulation.

[0077] 2, Second step: deprotection of the ketone function In a suitably sized reaction flask, the following are introduced sequentially under magnetic stirring at room temperature: 1 mol eq. of the copolymer obtained in the first step, 80 mol eq. of acetonitrile, and 5 mol eq. of deionized water. 0.2 mol eq. of trifluoromethanesulfonic acid is then added dropwise, and the reaction is maintained under stirring for 1 hour. After 1 hour, the acid is neutralized by the addition of 1 mol eq. of sodium carbonate as a saturated aqueous solution, which is maintained under stirring for a further 1 hour. The mixture is then filtered, and the solvent in the filtrate is evaporated under secondary vacuum. The colored liquid obtained is dissolved in an adequate volume of saturated sodium chloride solution, then extracted with an adequate volume of ethyl acetate. The resulting organic phase is collected, concentrated by partial evaporation of the organic solvent, and then purified by precipitation in methanol at -50°C. The precipitate formed is filtered, collected, and dried under secondary vacuum. The purity of the resulting copolymer is checked by NMR spectroscopy and can be improved by re-solubilizing 1 mass equivalent of the copolymer in 3 mass equivalents of acetone and repeating the above steps. The final product is a white, film-forming solid that is stored at +4°C before formulation.

[0078] Example 4: Solubility tests of the copolymer of the invention in different solvents

[0079] The solubility of the copolymer according to Example 2 was evaluated in different solvents. A mixture of each solvent and the copolymer according to Example 2 was prepared at room temperature in a 90 / 10 ratio, under magnetic stirring.

[0080] The mixture was poured into a 30 mL clear glass bottle (one bottle per solvent), and the bottle was then closed with its screw cap. The bottles were stored at room temperature, and a visual inspection of the filled bottles was performed at T4 hours, T18 hours, and T24 hours after filling. The copolymer is considered soluble in the solvent when the bottle, placed on a white background, is transparent to the naked eye at a distance of 20 cm, taking care to invert the bottle and carefully examine for the presence of polymer fragments in a swollen gel form, which would indicate an insoluble polymer network.

[0081] The results are presented in the following table 1.

[0082] [Tables 1] Solvent (10% wt. dry polymer solution) Solubilization time (hours) Butyl acetate 4h Absolute ethanol 18h Ethylhexyl salicylate 18h Dimethyl adipate 4h Isopropylideneglycerol 24h Methyl oleate 24h Dimethyl isosorbide 24h Neopentyl Glycol Diheptanoate 24h Coco-Caprylate / Caprate 24h Undecane (and) Tridecane (and) Tocopherol (and) Helianthus Annuus (Sunflower) Seed Oil 24h

[0083] Example 5: Characterization of the mechanical properties of a copolymer of the invention

[0084] Test specimens of films of the copolymer prepared in Example 2 were prepared. The polymer was solubilized at 30 wt% of dry polymer in ethyl acetate under magnetic stirring for 24 hours. After this time, the polymer was spread onto a suitable silicone-coated support using a calibrated spreading bar to obtain a film of controlled thickness, 200 µm thick. The film was then left to dry at room temperature for 24 hours. After this time, the film thickness was checked at 10 points evenly distributed across the support, and then a 50 x 10 mm test specimen was cut and used as a test sample.

[0085] Tensile tests were carried out with the reference TA.XTplusC Texture Analyser, using a 5 kg force sensor, at a fixed tensile speed of 1 mm / s. The Young's modulus of the copolymer film was observed to be less than 2 MPa. The recorded tensile curve can be viewed in [Fig. 1].

[0086] The copolymer of the invention is therefore very flexible, very easy to deform, and exhibits a certain degree of elasticity. It is thus able to follow the movements of the skin. Once formulated in a cosmetic product and applied to the skin of a user, the copolymer is therefore likely to provide both film-forming properties to the applied cosmetic product and a feeling of comfort to the user.

[0087] Example 6: Cosmetic composition according to the invention

[0088] Anhydrous lip balm [Tables 2] INGREDIENTS % SILICA 5.0 WAXES 8.5 POLYMER OF THE INVENTION (EXAMPLE 2) 2.0 SHEA BUTTER 1.5 INORGANIC PIGMENTS 8.0 ORGANIC PIGMENTS (LACKS) 2.0 OIL QSP100 The polymer according to the invention is solubilized in oil before being added to the anhydrous mixture. The composition is poured into a mold. The resulting product is applied to the lips and exhibits significantly improved hold.

[0089] Emulsion foundation [Tables 3] Ingredients (INCI Name) % by weight OILS ESTERS 6.5 MINERAL OIL 3.5 POLYMER OF INVENTION (EXAMPLE 3) 2 NON-SILICONE SURFACTANT 2 CAPRYLIC / CAPRIC TRIGLYCERIDES 2.2 BEESWAX 0.8 METHYL POLYMETHACRYLATE 1.1 INORGANIC PIGMENTS 15 SILICA 2 WATER q.s. The polymer is solubilized in the oils of the oil phase. The resulting emulsion is a water-in-oil emulsion. The foundation is applied to the skin and exhibits improved mechanical resistance (wear) and application comfort.

Claims

Demands

1. Cosmetic composition comprising a polymer obtained from 1,3-dihydroxyacetone, and at least one cosmetically acceptable ingredient other than butyl acetate and ethyl lactate, the polymer bearing a 3-acyloxy-2-oxopropyl side group.

2. Cosmetic composition according to claim 1, characterized in that the polymer is selected from poly(vinylpyrrolidone) and vinylpyrrolidone copolymers, poly(vinyl acetate), polyvinyl alcohols, poly(N-vinyl caprolactam), polyamides, poly(hydroxyurethane), polyethers, silicone polymers, acrylic polymers, acrylate / octylacrylamide copolymers and polysaccharides.

3. Cosmetic composition according to any one of the preceding claims, characterized in that the polymer is capable of being obtained from a monomer bearing a 3-hydroxy-2-oxopropyl or 3-acyloxy-2-oxopropyl group.

4. Cosmetic composition according to claim 3, characterized in that the polymer is a copolymer comprising at least one first repeating unit of formula (Al) . (Al) [Ri O^O in which Ri represents H or CH3, and R2 represents a saturated or unsaturated, linear or branched alkyl group having from 1 to 6 carbon atoms, or a -CH2=CH-R group, R representing an alkyl group having from 1 to 4 carbon atoms, and at least one second repeating unit, different from the first repeating unit.

5. Cosmetic composition according to claim 4, characterized in that Riet R2 each represent a methyl.

6. Cosmetic composition according to claim 4 or 5, characterized in that the at least second repeating motif corresponds to the formula (Bl) rr. ,(B1) i in which R3 represents H or CH3 and R4 represents H or a linear or branched alkyl group, saturated or unsaturated, having from 1 to 20 carbon atoms, for example a saturated linear alkyl group having from 4 to 18 carbon atoms.

7. Cosmetic composition according to claim 6, characterized in that R3 represents H or methyl, and R4 represents H, methyl, butyl, octyl or stearyl.

8. Cosmetic composition according to claim 7, characterized in that the copolymer comprises at least three repeating motifs (Bl) different from each other, the first being such that R3 represents methyl and R4 represents methyl, the second being such that R3 represents H and R4 represents butyl, and the third being such that R3 represents H and R4 represents H.

9. Method of applying to the skin, eyelids, eyelashes, lips, nails or hair, a polymer obtained from 1,3-dihydroxyacetone, the polymer having a 3-acyloxy-2-oxopropyl side group.

10. An application method according to claim 9, characterized in that the polymer conforms to the polymer of any one of claims 2 to R

11. d 0. A process for synthesizing a polymer bearing a 3-acyloxy-2-oxopropyl side group from 1,3-dihydroxyacetone, said process comprising a step (i) of polymerizing a monomer of formula (I) CH2=CR4-COO-CH2-C(ORa)(ORb)-CH2ORs (I) in which R4 represents H or CH3; R5 represents H or -OCR, R being a saturated or unsaturated, linear or branched alkyl group having from 1 to 6 carbon atoms; Ra and Rb each independently represent an alkyl group having 1 or 3 carbon atoms, or Ra and Rb are linked to form a divalent hydrocarbon group comprising 2 or 3 carbon atoms, to obtain an intermediate polymer bearing acetal functions -CH(ORa)(ORb)-, step i) being followed by a step ii) of transformation of the acetal functions of the intermediate polymer into ketone functions.

12. A synthesis process according to claim 11, characterized in that the monomer (I) is prepared from 1,3-dihydroxyacetone, in a step prior to step i).

13. A synthesis process according to claim 11 or 12, characterized in that the monomer of formula (I) is 3-hydroxy-2,2-dimethyloxypropyl (meth)acrylate or 3-acyloxy-2,2-dimethyloxypropyl (meth)acrylate.

14. A synthesis process according to any one of claims 11 to 13, characterized in that, in step i), the monomer of formula (I) is copolymerized with at least one comonomer, preferably a (meth)acrylic comonomer.

15. Synthesis process according to claim 14, characterized in that the comonomer is methyl methacrylate, butyl acrylate or acrylic acid.

16. Monomer of formula (I) CH2=CR4-COO-CH2-C(ORa)(ORb)-CH2ORs(I) in which R4 represents H or CH3; R5 represents -OCR, R being a saturated or unsaturated, linear or branched alkyl group having from 1 to 6 carbon atoms; Ra and Rb each independently represent an alkyl group having from 1 to 3 carbon atoms, or Ra and Rb are linked to form a divalent hydrocarbon group comprising 2 or 3 carbon atoms.