COSMETIC EMULSION CONTAINING A GEMINI SURFACTANT AND A LIPOPHILIC POLYMER

Abstract

Cosmetic emulsion containing a gemini surfactant and a lipophilic polymer The invention relates to a composition in the form of an emulsion, in particular in the form of an oil-in-water emulsion, comprising a gemini surfactant having a specific chemical structure with at least two fatty amide groups and at least one lipophilic polymer comprising at least hydroxyethyl acrylate units and acrylate units bearing a lipophilic group, wherein the weight ratio of the sum of all the hydroxyethyl acrylate units to the sum of all the acrylate units bearing a lipophilic group ranges from 1:30 to 1:1 and wherein the lipophilic polymer has a number-average molecular weight Mn ranging from 2000 to 9000 g/mol. The composition in accordance with the invention makes it possible to obtain a cosmetic emulsion having an increased sun protection factor, while at the same time having good cosmetic properties, such as a non-greasy and non-tacky feel, while at the same time being stable, in particular from the physicochemical viewpoint.

Claims

1. A composition in the form of an emulsion comprising at least one UV-screening agent, at least one gemini surfactant having the chemical formula below, and also the stereoisomers thereof: ##STR00008## in which: a) R.sub.1 denotes an alkyl radical having from 1 to 25 carbon atoms or a radical having the formula below:
—(CH.sub.2).sub.k1—CH[—NH—CO—(CH.sub.2).sub.l—CH.sub.3]—(CH.sub.2).sub.j1—Y′ b) R.sub.3 denotes an alkyl radical having from 1 to 25 carbon atoms or a radical having the formula below:
—(CH.sub.2).sub.k2—CH[—NH—CO—(CH.sub.2).sub.l—CH.sub.3]—(CH.sub.2).sub.j2—Y′ c) R.sub.2 denotes a spacer constituted of a linear or branched alkylene chain having from 1 to 12 carbon atoms or of a radical of formula —CH(Y′)—(CH.sub.2).sub.n′—; with: n′ representing an integer between 1 and 8; Y′ representing, independently of one another, a carboxylic acid group or an alkaline salt of a carboxylic acid group; j1, k1, j2 and k2 representing an integer such that (j1, k1, j2, k2)=(2, 0, 2, 0), (2, 0, 0, 2), (0, 2, 2, 0) or (0, 2, 0, 2); and l representing an integer from 6 to 16; and d) X and Y denote, independently of each other, a group —(C.sub.2H.sub.4O).sub.a—(C.sub.3H.sub.6O).sub.bZ, in which Z denotes a hydrogen atom or a radical —CH.sub.2—COOM, —SO.sub.3M, —P(O)(OM).sub.2, —C.sub.2H.sub.4—SO.sub.3M, —C.sub.3H.sub.6—SO.sub.3M or —CH.sub.2(CHOH).sub.4CH.sub.2OH, where M and M′ represent H or an alkali metal or alkaline-earth metal or ammonium or alkanolammonium ion, a ranges from 0 to 15, b ranges from 0 to 10, and the sum of a+b ranges from 1 to 25; and e) n ranges from 1 to 10; and at least one lipophilic polymer comprising monomeric units of formulae (A) and (B): ##STR00009## in which: R, independently of one another, are chosen from alkyl or alkylene radicals; with at least 60% by weight of the R groups being behenyl radicals, the percentage by weight relating to the sum of all the R groups present in the polymer; the weight ratio of the sum of all the hydroxyethyl acrylate units to the sum of all the acrylate units bearing the R group ranges from 1:30 to 1:1; and the sum of the total units A and B is at least 95% by weight of the total weight of the polymer; the polymer having a number-average molecular weight Mn ranging from 2000 to 9000 g/mol.

2. The composition according to claim 1, in which the at least one gemini surfactant is chosen from the compounds of formula (II), and also the stereoisomers thereof: ##STR00010## in which: R.sub.1 and R.sub.3 denote, independently of each other, an alkyl radical containing from 1 to 25 carbon atoms; R.sub.2 denotes a spacer constituted of a linear or branched alkylene chain containing from 1 to 12 carbon atoms; X and Y denote, independently of each other, a group —(C.sub.2H.sub.4O).sub.a—(C.sub.3H.sub.6O).sub.bZ, in which Z denotes a hydrogen atom or a radical —CH.sub.2—COOM, —SO.sub.3M, —P(O)(OM).sub.2, —C.sub.2H.sub.4—SO.sub.3M, —C.sub.3H.sub.6—SO.sub.3M or —CH.sub.2(CHOH).sub.4CH.sub.2OH, where M and M′ represent H or an alkali metal or alkaline-earth metal or ammonium or alkanolammonium ion, a ranges from 0 to 15, b ranges from 0 to 10, and the sum of a+b ranges from 1 to 25; and n ranges from 1 to 10.

3. The composition according to claim 2, in which, for the at least one gemini surfactant of formula (II), each of the R.sub.1—CO— and R.sub.3—CO— groups comprises from 8 to 20 carbon atoms.

4. The composition according to claim 2, in which, for the gemini surfactant of formula (II), each of the R.sub.1—CO— and R.sub.3—CO— groups denotes a coconut fatty acid residue.

5. The composition according to claim 2, in which, for the at least one gemini surfactant of formula (II), for each of the X and Y radicals, the sum of a and b has a mean value ranging from 10 to 20.

6. The composition according to claim 2, in which, for the at least one gemini surfactant of formula (II), Y is the —SO.sub.3M group, where M is an alkali metal ion.

7. The composition according to claim 2, in which, for the at least one gemini surfactant of formula (II), n is equal to 1.

8. The composition according to claim 2, in which the at least one gemini surfactant of formula (II) has the following structure: ##STR00011##

9. The composition according to claim 2, in which the at least one gemini surfactant is mixed with (a) a glyceryl ester of a C.sub.6-C.sub.22 fatty acid, (b) a diester of a C.sub.6-C.sub.22 fatty acid and of citric acid and of glycerol, and (c) a C.sub.10-C.sub.30 fatty alcohol.

10. The composition according to claim 1, in which the at least one gemini surfactant is chosen from the compounds of formula (III), and also the stereoisomers thereof: ##STR00012## in which: Y′ represent, independently of one another, a carboxylic acid group or an alkaline salt of a carboxylic acid group; j1, k1, j2 and k2 represent an integer such that (j1, k1, j2, k2)=(2, 0, 2, 0), (2, 0, 0, 2), (0, 2, 2, 0) or (0, 2, 0, 2); and l represents an integer from 6 to 16.

11. The composition according to claim 10, in which, in formula (III), 1 represents an integer ranging from 8 to 12, j1=j2=0, and k1=k2=2.

12. The composition according to claim 10, in which, in formula (III), Y′ represents —COONa, j1=j2=0, k1=k2=2; and l=10.

13. The composition according to claim 10, in which the at least one gemini surfactant of formula (III) are is chosen from sodium dilauramidoglutamide lysine, sodium dimyristoylglutamide lysine and sodium distearoylglutamide lysine.

14. The composition according to claim 1, in which, in the lipophilic polymer, R is constituted of alkyl radicals.

15. The composition according to claim 1, in which, in the lipophilic polymer, at least 70% by weight of the R groups are behenyl radicals.

16. The composition according to claim 1, in which, the lipophilic polymer, all the R groups are behenyl radicals.

17. The composition according to claim 1, in which, in the lipophilic polymer, the weight ratio of the sum of all the hydroxyethyl acrylate units to the sum of all the acrylate units bearing the R group ranges from 1:15 to 1:1.

18. The composition according to claim 1, in which the lipophilic polymer has a number-average molecular weight Mn ranging from 5000 to 9000 g/mol.

19. The composition according to claim 1, in which the lipophilic polymer has a melting point ranging from 60° C. to 69° C.

20. The composition according to claim 1, in which the least one lipophilic polymer is present in an amount of active material ranging from 0.1% 10% by weight relative to the total weight of the composition.

21. A process for caring for and/or removing makeup from and/or cleansing keratin materials which comprises applying to the keratin materials Cosmetic use a composition according to claim 1.

22. A cosmetic process for treating a keratin material, in which a composition as defined in claim 1 is applied to the keratin material.

Description

EXAMPLES

[0434] Example of Lipophilic Polymer Synthesis

[0435] Determination of the Molecular Weight by Gel Permeation Chromatography (GPC):

[0436] The sample is prepared by preparing a solution of the polymer at 10 mg/ml in tetrahydrofuran. The sample is placed in an oven at 54° C. for 10 minutes and then in an oscillating shaker for 60 minutes in order to assist with the dissolution. After visual inspection, the sample appears to be totally dissolved in the solvent.

[0437] The sample prepared was analysed using two polypore 300×7.5 mm columns (manufactured by Agilent Technologies), a Waters 2695 chromatographic system, a tetrahydrofuran mobile phase and detection by refractive index. The sample was filtered through a 0.45 μm nylon filter, before being injected into the liquid chromatograph. The standard used for the calibration are the Easi Vial narrow polystyrene (PS) standards from Agilent Technologies.

[0438] Polystyrene standards ranging from 2 520 000 to 162 Daltons were used for the calibration.

[0439] The system is equipped with a PSS SECcurity 1260 RI detector. The polystyrene calibration curve was used to determine the average molecular weight. The recording of the diagrams and the determination of the various molecular weights was carried out by the Win GPC Unichrom 81 program.

[0440] Determination of the Melting Point by Differential Scanning Calorimetry (or DSC):

[0441] This method describes the general procedure for determining the melting point of polymers by differential scanning calorimetry. This method is based on the standards ASTM E791 and ASTM D 34182 and the DSC calibration is carried out according to the standard ASTM E 9672.

[0442] Behenyl Acrylate/2-Hydroxyethyl Acrylate Copolymer (Polymer 1):

[0443] In a 4-necked flask equipped with side-blade mixer, an internal thermometer, two funnels, a reflux condenser, and an extension for two other necks, 175 g of behenyl acrylate, 25 g of 2-hydroxyethyl acrylate and 0.4 g of 2,2′-azobis(2-methylbutyronitrile) (AkzoNobel) were added, over the course of 60 minutes at 80° C., to 40 g of isopropanol, with stirring, after having removed the oxygen from the system by means of a nitrogen flush for 20 minutes.

[0444] The mixture was stirred at 80° C. for 3 hours. The solvent was then eliminated by vacuum distillation, then 1 g of dilauryl peroxide was added and the reaction was continued for 60 minutes at 110° C. The step was repeated. The mixture was then cooled to 90° C. and a jet of demineralized water was added, then the mixture was stirred. The water was eliminated by vacuum distillation.

[0445] Molecular weight: Mn=7300 g/mol, Mw=21000, Mw/Mn=2.8

[0446] Melting point: 65° C.

Formulation Examples

[0447] The compositions described in the examples below were prepared according to the following procedure:

[0448] 1—Prepare the oily phase by introducing the screening agents into said oily phase.

[0449] Dissolve the screening agents by heating to 70° C., add the fatty-phase structuring polymer and heat until the polymer has completely dissolved.

[0450] 2—Prepare the aqueous phase and add the gemini surfactant, heat the phase to the same temperature as the fatty phase.

[0451] 3—Emulsify the two phases together using a mixer of rotor/stator type at 70° C., then cool to 30° C., and add the thickeners and the alcohol.

[0452] For each composition, the viscosity was measured, then the sensory aspect was evaluated during and after application thereof to the skin; the in vitro SPF value was also measured.

[0453] Viscosity Measurement

[0454] The viscosity measurement is generally performed at 25° C., using a Rheomat RM180® viscometer equipped with a No. 2 or 3 spindle, the measurement being performed after 10 minutes of rotation of the spindle in the composition (after which time stabilization of the viscosity is observed) at a shear rate of 200 s.sup.−1.

[0455] Protocol for Evaluating the Tack and the Greasiness

[0456] The tack is evaluated by a panel of sensory experts made up of 5 individuals. Each composition is applied to the forearm at a dose of 2 mg/cm.sup.2. The product was spread by circular movements until it had penetrated (approximately 30 seconds). The tack is evaluated after 2 minutes of drying, by applying the back of the hand to the treated area, according to scale ranging from 1 to 15 in which 1 constitutes a reference that is not very tacky or not very greasy and 15 constitutes a reference that is very tacky or very greasy.

[0457] In Vitro SPF

[0458] The sun protection factor (SPF) is determined according to the “in vitro” method described by B. L. Diffey in J. Soc. Cosmet. Chem. 40, 127-133, (1989). The measurements were taken by means of a UV-2000 spectrophotometer from the company Labsphere. Each composition is applied to a rough plate of PMMA, in the form of a uniform and even deposit in a proportion of 1.3 mg/cm.sup.2.

Example 1 According to the Invention: Composition in the Form of a Direct Emulsion

[0459] The following composition was prepared:

TABLE-US-00001 Composition A (inven- tion) OCTOCRYLENE 7.00 (UVINUL N539 from BASF) ETHYLHEXYL SALICYLATE 5.00 (NEO HELIOPAN OS/H from SYMRISE) BUTYL METHOXYDIBENZOYLMETHANE 3.00 (CHEM 1789 from EMSPEC CHEMICALS) ISONONYL ISONONANOATE 4.00 (DUB ININ from STEARINERIES DUBOIS) DISODIUM ETHYLENEDIAMINE TETRAACETATE 0.1 DIHYDRATE POLYDIMETHYLSILOXANE (VISCOSITY: 5 cSt) 2.5 ALPHA-OMEGA DIHYDROXYL 2 POLYDIMETHYLSILOXANE/ POLYDIMETHYLSILOXANE MIXTURE 5 CST GLYCEROL 7.00 XANTHAN GUM 0.25 ETHOXYLATED (15 EO) SODIUM ETHYLDIAMIDO- 3.5 N-COCOYL SULFONATE/BEHENYL ALCOHOL/ GLYCERYL STEARATE/CITRATE MIXTURE (CERALUTION H from SASOL) POLYACRYLAMIDOMETHYLPROPANESULFONIC 0.5 ACID PARTIALLY NEUTRALIZED WITH AQUEOUS AMMONIA AND HIGHLY CROSSLINKED Polymer 1 as previously synthesized 2 PRESERVATIVE(S) 1 WATER qs 100

[0460] The composition A in accordance with the present invention has good sun protection factor, while at the same time having good cosmetic properties, such as anon-greasy and non-tacky feel, while at the same time being stable, in particular from the physicochemical viewpoint.

Comparative Example 2: Compositions in the Form of Direct Emulsions

[0461] The following compositions are prepared.

TABLE-US-00002 Composition B C D (inven- (inven- (compar- tion) tion) ative) BIS-ETHYLHEXYLOXYPHENOL 4.50 4.50 4.50 METHOXYPHENYL TRIAZINE (TlNOSORB S from BASF) ETHYLHEXYL SALICYLATE 5.00 5.00 5.00 (NEO HELIOPAN OS/H from SYMRISE) DIETHYLAMINO 5.50 5.50 5.50 HYDROXYBENZOYL HEXYL BENZOATE (UVINUL A PLUS GRANULAR from BASF) ETHYLHEXYL TRIAZONE 3.50 3.50 3.50 (UVINUL T 150 from BASF) DICAPRYLYL CARBONATE 10.00  10.00  10.00  DIISOPROPYL SEBACATE 7.00 7.00 7.00 CAPRYLIC/CAPRIC 5.00 5.00 5.00 TRIGLYCERIDE DEXTRIN PALMITATE 2.00 2.00 2.00 ETHOXYLATED (15 EO) 3.00 2.00 — SODIUM ETHYLDIAMIDO-N- COCOYL SULFONATE/ BEHENYL ALCOHOL/ GLYCERYL STEARATE/CITRATE MIXTURE (CERALUTION H from SASOL) STEARIC ACID — — 1.50 GLYCERYL — — 1.50 MONO/DISTEARATE/ POLYETHYLENE GLYCOL STEARATE (100 EO) MIXTURE (50/50) (ARLACEL 165 from CRODA) Polymer 1 as previously 2.00 3.00 2.00 synthesized GLYCEROL 3.00 3.00 3.00 pH ADJUSTER(S) 0.5  0.5  0.5  PROPANEDIOL 3.00 3.00 3.00 PRESERVATIVE(S) 0.50 0.50 0.50 LIGHTLY CROSSLINKED 1.50 1.50 1.50 ACRYLIC POLYMER IN EMULSION, in solution at 30% in water (CARBOPOL AQUA SF-1 from LUBRIZOL) DENAT. ALCOHOL 5.00 5.00 5.00 WATER qs 100 qs 100 qs 100

[0462] The following results were obtained.

TABLE-US-00003 Composition B C D (inven- (inven- (compar- tion) tion) ative) Viscosity (Pa .Math. s) at 24 h 1.23 1.17 0.94 Non-tacky finish (Score by 4.7 ± 0.2 4.1 ± 0.8 7.2 ± 1.8 sensory expert panel, out of 15; 1 = not very tacky; 15 = very tacky) Non-greasy finish (Score by 4.1 ± 0.2 4.4 ± 0.6 6.6 ± 1.0 sensory expert panel, out of 15; 1 = not very greasy; 15 = very greasy) in vitro SPF 79.1 ± 5.6  80.9 ± 6.1  58.9 ± 5.9 

[0463] These results show that the compositions B and C according to the invention comprising a gemini surfactant (Ceralution H from Sasol) make it possible to obtain a better sun protection factor than the composition D according to the prior art comprising a surfactant which is nota gemini surfactant and the same UV-screening agent at the same concentration, at the same time having a less tacky and less greasy skin finish.

Comparative Example 3: Compositions in the Form of Direct Emulsions

[0464] The following compositions were prepared.

TABLE-US-00004 Composition E F (inven- (compar- tion) ative) BUTYL METHOXYDIBENZOYLMETHANE 3.00 3.00 (EUSOLEX 9020 from MERCK) ETHYLHEXYL SALICYLATE 5.00 5.00 (NEO HELIOPAN OS/H from SYMRISE) ETHYLHEXYL TRIAZONE 2.50 2.50 (UVINUL T 150 from BASF) TEREPHTHALYLIDENE DICAMPHOR 0.9 0.9 SULFONIC ACID (MEXORYL SX from CHIMEX) DROMETRIZOLE TRISILOXANE 3.00 3.00 (SILATRIZOLE from RHODIA) BIS-ETHYLHEXYLOXYPHENOL 5.00 5.00 METHOXYPHENYL TRIAZINE (TlNOSORB S from BASF) DISODIUM 0.1 0.1 ETHYLENEDIAMINETETRAACETATE DIHYDRATE pH ADJUSTER(S) 0.41 0.41 DIISOPROPYL SEBACATE 8.00 8.00 ISOPROPYL N-LAUROYL 1.00 1.00 SARCOSINATE ETHOXYLATED (15 EO) SODIUM 2.00 2.00 ETHYLDIAMIDO-N-COCOYL SULFONATE/BEHENYL ALCOHOL/ GLYCERYL STEARATE/CITRATE MIXTURE (CERALUTION H from SASOL) LIGHTLY CROSSLINKED ACRYLIC 2.00 2.00 POLYMER IN EMULSION, in solution at 30% in water (CARBOPOL AQUA SF-1 from LUBRIZOL) Polymer 1 as previously synthesized 3.00 — POLY C10-30 ALKYL ACRYLATE — 3.00 (INTELIMER IPA 13-1 NG from AIR PRODUCTS AND CHEMICALS) DENAT. ALCOHOL 10.00 10.00 GLYCEROL 6.00 6.00 PRESERVATIVE(S) 0.50 0.50 Water qs 100 qs 100

[0465] The following results were obtained.

TABLE-US-00005 Composition E F (invention) (comparative) Viscosity (Pa .Math. s) at 24 h 0.12 0.15 Non-tacky finish (Score by sensory expert  2.6 ± 1.5  6.3 ± 0.3 panel, out of 15; 1 = not very tacky; 15 = very tacky) in vitro SPF 62.7 ± 1.5 50.1 ± 2.8

[0466] These results show that the composition E comprising a lipophilic polymer according to the invention (Polymer 1) makes it possible to obtain an in vitro SPF value much higher than that which is obtained with the composition F according to the prior art comprising another lipophilic polymer (Interlimer IPA 13-1 NG from Air Products and Chemicals) and the same UV-screening agent, at the same concentration, while at the same time having a less tacky skin finish.