COMPOSITION COMPRISING PHOTONIC PARTICLES, A UV-SCREENING AGENT AND AN ACRYLIC POLYMER

Abstract

The present invention relates to a composition, especially a photoprotective cosmetic composition, comprising at least: photonic particles having a mean size of from 0.5 m to 100 m, each including an ordered periodic arrangement of monodisperse nanoparticles or of empty spaces, leading to attenuation of the radiation in the wavelength range extending from 250 nm to 1800 nm, preferably from 250 nm to 400 nm, b) at least one UV-screening agent, and at least one particular acrylic polymer.

Claims

1. A composition, comprising at least: a) photonic particles having a mean size of from 0.5 m to 100 m, each including an ordered periodic arrangement of monodisperse nanoparticles or of empty spaces, leading to attenuation of the radiation in the wavelength range extending from 250 nm to 1800 nm, and b) at least one UV-screening agent, and c) at least one polymer comprising monomer units of formulae (A) and (B): ##STR00003## in which: R1, independently at each instance, is chosen from alkyl and alkylene radicals, and at least 60% by weight of the groups R1 are radicals chosen from stearyl and behenyl radicals, the weight percentage relating to the sum of all the groups R1 present in the polymer, and the weight ratio of the sum of all the hydroxyethyl acrylate units to the sum of all the acrylate units bearing the group R1 ranges from 1:30 to 1:1, and the sum of the total of units A and B is at least 95% by weight relative to 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 photonic particles including nanoparticles have no matrix.

3. The composition according to claim 1 either of claims 1 and 2, in which the nanoparticles comprise silica, at least one metal oxide, or a mixture of silica and at least one metal oxide.

4. The composition n according to claim 1, in which the nanoparticles are constituted of silica.

5. The composition according to claim 1, in which the mean size of the nanoparticles is from 100 nm to 500 nm.

6. The composition according to claim 1, in which the photonic particles are substantially spherical in shape.

7. The composition according to claim 1, in which the photonic particles have a mean size of from 1 m to 40 m.

8. The composition according to claim 1, in which the mass content of photonic particles is from 0.1% to 50% by weight relative to the total weight of the composition.

9. The composition according to claim 1, in which the at least one UV-screening agent is chosen from UV-screening agents that may be chosen from hydrophilic, lipophilic or insoluble organic UV-screening agents and inorganic UV-screening agents, and mixtures thereof.

10. The composition according to claim 1, in which the content of at least one UV-screening agent is from 0.01% to 60% by weight, relative to the total weight of said composition.

11. The composition according to claim 1, wherein, in polymer c), R1 consists of an alkyl radical.

12. The composition according to claim 1, wherein, in polymer c), at least 70% by weight of the groups R1 are behenyl or stearyl radicals.

13. The composition according to claim 1, wherein, in polymer c), all the groups R1 are stearyl or behenyl radicals.

14. The composition according to claim 1, wherein, in polymer c), said weight ratio ranges from 1:15 to 1:1.

15. The composition according to claim 1, wherein polymer c) has a number-average molecular weight Mn ranging from 5000 to 9000 g/mol.

16. The composition according to claim 1, wherein polymer c) has a melting point ranging from 40 C. to 70 C.

17. The composition according to claim 1, wherein, in polymer c), at least 60% by weight of the groups R1 are stearyl radicals, and polymer c) has a melting point ranging from 40 to 60 C.

18. The composition according to claim 1, wherein, in polymer c), at least 60% by weight of the groups R1 are behenyl radicals, and said polymer c) has a melting point ranging from 60 C. to 70 C.

19. The composition according to claim 1, wherein the content of polymer c) is from 0.01% to 15% by weight, relative to the total weight of said composition.

20. A non-therapeutic process for the photoprotection of keratin materials with respect to solar UV radiation, comprising a step of applying a cosmetic composition according to claim 1 to said keratin materials.

21. A non-therapeutic cosmetic process for limiting the darkening of the skin and/or improving the colour and/or uniformity of the complexion, comprising a step of applying a cosmetic composition according to claim 1 to the skin.

22. A non-therapeutic cosmetic process for preventing and/or treating the signs of ageing of a keratin material, comprising a step of applying a cosmetic composition according to claim 1 to the surface of said keratin material.

Description

EXAMPLES

Example 1Preparation of Photonic Particles in Accordance with the Invention

[0394] The aqueous dispersion of silica particles (Cosmo S-160NP from JGC) was atomized according to the following process.

[0395] The commercial dispersion is used as obtained, or is mixed with water to obtain a mass concentration of particles equal to about 18%.

[0396] The dispersion thus obtained was introduced into an atomizer (Niro Minor Production), the injection rate being set at 3800 g/h, the turbine speed being set at 37 800 rpm and the atomization temperature being set at 290 C.

[0397] The opals obtained are direct opals with a mean size (D 0.5) of 12.2 m, in the form of a dry powder.

Example 2 of Preparation of Polymer 1

[0398] Determination of the molecular weight by gel permeation chromatography (GPC):

[0399] 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 to aid dissolution. After visual inspection, the sample appears to be totally dissolved in the solvent.

[0400] The sample prepared was analysed using two polypore 3007.5 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 m nylon filter, before being injected into the liquid chromatograph. The standards used for the calibration are the Easi Vial narrow polystyrene (PS) standards from Agilent Technologies.

[0401] Polystyrene standards ranging from 2 520 000 to 162 daltons were used for the calibration.

[0402] 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 were performed by the Win GPC Unichrom 81 program.

[0403] Determination of the melting point by differential scanning calorimetry (or DSC):

[0404] 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 performed according to standard ASTM E 9672.

[0405] Behenyl Acrylate/2-Hydroxyethyl Acrylate Copolymer (Polymer 1):

[0406] 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) (Akzo Nobel) 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. The mixture was stirred at 80 C. for 3 hours. The solvent was then removed by vacuum distillation, 1 g of dilauryl peroxide was then added and the reaction was continued for 60 minutes at 110 C. The step was repeated. The mixture was then cooled to 90 C., a stream of demineralized water was added and the mixture was then stirred. The water was removed by vacuum distillation.

[0407] Molecular weight: Mn=7300 g/mol, Mw=21 000, Mw/Mn=2.8

[0408] Melting point: 65 C.

Example 3 of Preparation of Polymer 2

[0409] Stearyl Acrylate/2-Hydroxyethyl Acrylate Copolymer (Polymer 2)

[0410] 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, 155 g of behenyl acrylate, 45 g of 2-hydroxyethyl acrylate and 0.4 g of 2,2-azobis(2-methylbutyronitrile) (Akzo Nobel) were added, over the course of 90 minutes at 80 C., to 50 g of isopropanol, with stirring, after having removed the oxygen from the system by means of a nitrogen flush for 20 minutes. The mixture was stirred at 80 C. for 3 hours. The solvent was then removed by vacuum distillation, 1 g of dilauryl peroxide was then added and the reaction was continued for 60 minutes at 125 C. The step was repeated. The mixture was then cooled to 90 C., a stream of demineralized water was added and the mixture was then stirred. The water was removed by vacuum distillation.

[0411] Molecular weight: Mn=7500 g/mol, Mw=19 000, Mw/Mn=2.6

[0412] Melting point: 49 C.

Examples 4 to 6Preparation of a Composition in Accordance with the Invention

[0413] The following O/W emulsions were prepared:

TABLE-US-00001 4 Phase INCI name (invention) 5 6 A Bis(ethylhexyloxyphenol) 3.00 3.00 3.00 methoxyphenyltriazine Drometrizole trisiloxane 2.00 2.00 2.00 (Mexoryl XL) Homosalate 8.00 8.00 8.00 Octyl salicylate 5.00 5.00 5.00 Diethylamino hydroxybenzoyl 3.00 3.00 3.00 hexyl benzoate Octocrylene 1.50 1.50 1.50 Dicaprylyl carbonate 3.00 3.00 3.00 Diisopropyl sebacate 3.00 3.00 3.00 Isohexadecane 2.00 2.00 2.00 Isopropyl lauryl sarcosinate 4.00 4.00 4.00 Poly C10-30 alkyl acrylate 2.00 (Intelimer IPA-13.1) (polymer not in accordance with the invention) Behenyl alcohol (and) glyceryl 2.00 2.00 2.00 stearate (and) disodium ethylene dicocamide PEG-15 disulfate (and) glyceryl stearate citrate (Ceralution H from Sasol) Polymer 1 according 2.00 to Example 2 B Glycerol 5.00 5.00 5.00 Caprylyl glycol 0.50 0.50 0.50 Phenylbenzimidazolesulfonic 2.00 2.00 2.00 acid Tromethamine 1.80 1.80 1.80 Xanthan gum 0.50 0.50 0.50 Water qs 100 qs 100 qs 100 C Photonic compound 4.00 4.00 4.00 according to Example 1 D Denatured alcohol 5.00 5.00 5.00 in vitro SPF 61.1 4.1 37.4 2.5 31.7 1.2 Transparency on the skin (Score 10.8 2.8 10.8 2.7 11.1 2.1 from an expert sensory panel, out of 15: 1 = white/opaque; 15 = transparent) Softness on application (Score from 13.0 1.1 13.7 0.4 13.8 0.7 an expert sensory panel, out of 15: 1 = not very soft; 15 = soft)

[0414] Preparation Method [0415] The compositions described in Examples 2 to 4 below were prepared according to the following procedure: [0416] 1Prepare the oily phase (Phase A) by introducing the screening agents. [0417] Dissolve the screening agents by heating to 70 C., add the fatty-phase structuring polymer and heat until the polymer has completely dissolved. [0418] 2Prepare the aqueous phase (Phase B) and heat the phase to 70 C. [0419] 3Emulsify the two phases together using a rotor/stator mixer such as a Moritz blender at 70 C., then cool to 30 C. [0420] 4Introduce the photonic particles (Phase C) with slow stirring using a Rayneri blender. [0421] 5Add phase D with slow stirring using a Rayneri blender.

[0422] Compositions 4 to 6 are homogeneous and stable for 2 months at 4 C., at room temperature and at 45 C.

[0423] The addition of polymer c) according to the invention makes it possible to increase the SPF very significantly, in contrast with another acrylic polymer not in accordance with the invention.

[0424] Composition 4 has a high SPF while at the same time having excellent cosmetic properties. The transparency on the skin and the softness are markedly superior for composition 4 according to the invention.

[0425] Results of the same type will be obtained by replacing polymer 1 with polymer 2 in composition 4.