WATER-RESISTANT COSMETIC COMPOSITION

Abstract

The invention relates to a cosmetic composition in the form of an emulsion which is water-resistant due to the use of an emulsifying polymer. This polymer is prepared by polymerization of an anionic monomer and a C.sub.1-C.sub.7 unsaturated carboxylic acid ester. The cosmetic composition according to the invention is free of film-forming agent and surfactant compound. The invention also relates to the preparation and the use of this cosmetic composition.

Claims

1. A cosmetic composition in form of a water-resistant emulsion that is free of any film-forming agents and of surface-active compounds and comprising: particles of a lipophilic phase comprising at list one a lipophilic compound, dispersed in: a continuous hydrophilic phase with a pH greater than or equal to 6.5 and comprising: a hydrophilic compound and an emulsifying polymer (P) prepared by at least one polymerisation reaction: a monomer (a1) of at least one anionic monomer comprising a polymerisable olefinic unsaturation and a carboxylic acid group or one of its salts, and a monomer (a2) of at least one C.sub.1—C.sub.7 ester of a compound derived from an acid selected from the group consisting of acrylic acid, methacrylic acid, maleic acid, maleic anhydride, itaconic acid and crotonic acid.

2. The composition according to claim 1, comprising from 0.1 to 75% by weight, of dispersed lipophilic phase relative to a total amount by weight of continuous hydrophilic phase and of dispersed lipophilic phase.

3. The composition according to claim 1, wherein the lipophilic phase comprises a lipophilic compound selected from the group consisting of fatty acids, fatty alcohols, butters, waxes, oils).

4. The composition according to claim 1, wherein the hydrophilic compound is chosen among water alone or in combination with at least one compound selected from the group consisting of glycerol, polyglycerols, glycols moisteners, and sugar derivatives.

5. The composition according to claim 1, with: a pH greater than 4; a pH less than 13; or a pH ranging from 4 to 13.

6. The composition according to claim 1, wherein: the monomer (a1) is selected from the group consisting of acrylic acid, methacrylic acid, maleic acid, maleic anhydride, itaconic acid, crotonic acid, an acrylic acid salt, a methacrylic acid salt, a maleic acid salt, a maleic anhydride salt, an itaconic acid salt, a crotonic acid salt and combinations thereof or the monomer (a2) is a C.sub.1—C.sub.6 ester, a C.sub.1-C.sub.7 acrylic acid ester, or a C.sub.1-C.sub.7 methacrylic acid ester or the monomer (a1) is chosen among acrylic acid, methacrylic acid, maleic acid, maleic anhydride, itaconic acid, crotonic acid, an acrylic acid salt, a methacrylic acid salt, a maleic acid salt, a maleic anhydride salt, an itaconic acid salt, a crotonic acid salt and combinations thereof; and monomer (a2) is a C.sub.1—C.sub.6 ester, a C.sub.1—C.sub.7 acrylic acid ester, or a C.sub.1—C.sub.7 methacrylic acid ester or the polymerisation reaction uses: from 20 to 70 mol % of the monomer (a1) and from 30 to 80 mol % of the monomer (a2), relative to a total molar amount of the monomers (a1) and (a2).

7. The composition according to claim 1, wherein the hydrophilic phase comprises from 0.4 to 10% by weight of polymer (P) relative to an amount of hydrophilic phase.

8. The composition according to claim 1, wherein the emulsifying polymer (P) is prepared by polymerisation reaction which also uses: monomer (a3), which is at least one compound chosen among 2-acrylamido-2-methylpropane sulphonic acid, ethoxymethacrylate sulphonic acid, sodium methallyl sulphonate, styrene sulphonate, hydroxyethyl acrylate phosphate, hydroxypropyl acrylate phosphate, hydroxyethylhexyl acrylate phosphate, hydroxyethyl methacrylate phosphate, hydroxypropyl methacrylate phosphate, hydroxyethylhexyl methacrylate phosphate, their salts and combinations thereof; monomer (a4) which is at least one compound chosen among hydroxyethyl-acrylate, hydroxypropyl-acrylate, hydroxyethylhexyl-acrylate, hydroxyethyl-methacrylate, hydroxypropyl-methacrylate, hydroxyethylhexyl-methacrylate or monomer (a5) which is at least one cross-linking monomer or at least one monomer comprising at least two olefinic unsaturations.

9. The composition according to claim 1, wherein: the polymer (P) is fully or partially neutralised or the polymer (P) is fully or partially coacervated .sub.4.

10. The composition according to claim 1, further comprising mineral particles, coated mineral particles, an organic sunscreen, active lipophilic cosmetic molecules, or active water-soluble cosmetic molecules.

11. A formulation chosen among a sunscreen formulation, a makeup formulation, a skin care formulation and a hair care formulation, comprising at least one cosmetic composition according to claim 1.

12. A method of preparing a cosmetic composition in form of a water-resistant emulsion that is free of any film-forming agents and of surface-active compounds and comprising: preparing a continuous hydrophilic phase comprising: a hydrophilic compound with a pH greater than or equal to 6.5 and an emulsifying polymer (P) prepared by at least one polymerisation reaction: a monomer (a1) of at least one anionic monomer comprising a polymerisable olefinic unsaturation and a carboxylic acid group or one of its salts and a monomer (a2) of at least one C.sub.1-C.sub.7 ester of a compound derived from an acid selected from the group consisting of acrylic acid, methacrylic acid, maleic acid, maleic anhydride, itaconic acid and crotonic acid, preparing a continuous hydrophilic phase comprising a lipophilic compound, then adding under stirring and in an absence of a surface-active compound of a lipophilic phase in a hydrophilic phase.

13. The method of preparation according to claim 12: in which the adding is carried out at a temperature ranging from 10 to 90° C. or also comprising adjusting a final pH of the composition.

14. (canceled)

15. A method of improving the water resistance of a cosmetic composition in form of an emulsion, free of film-forming agents and of surface-active compounds, comprising adding in a cosmetic composition of at least one emulsifying polymer (P) prepared by at least one polymerisation reaction: monomer (a1) of at least one anionic monomer comprising a polymerisable olefinic unsaturation and a carboxylic acid group or one of its salts and monomer (a2) of at least one C.sub.1-c7 ester of a compound derived from an acid chosen among acrylic acid, methacrylic acid, maleic acid, maleic anhydride, itaconic acid and crotonic acid.

16. A method of cosmetic treatment, the method comprising applying the composition according to claim 1.

Description

EXAMPLES

[0093] The following examples illustrate the various aspects of the invention. The following abbreviations are used: [0094] MAA: Methacrylic Acid, [0095] EA: Ethyl Acrylate, [0096] DAP: Diallyl Phthalate, [0097] Clariant Polyglykol B11/50: propylene oxide ethylene oxide monobutyl ether, [0098] Huntsmann Empicol LXVN: sodium lauryl sulphate (SLS), [0099] BASF Texapon NS0: ammonium laureth sulphate in 28% solution or ammonium lauryl ether sulphate in 28% solution (SLES), [0100] sodium persulphate (NH.sub.4).sub.2S.sub.2O.sub.8, [0101] straight (C.sub.16—C.sub.18)-alkyl-(EO)25-methacrylate (monomer (x)).

Example 1

Preparation of Polymers (P1) according to the Invention and Comparative Polymer (CP1) according to a Semi-Batch Method

[0102] In a stirred 1L reactor heated using an oil bath, mixture 1 is prepared by introducing deionised water and a sodium lauryl sulphate (SLS) solution or an aqueous solution containing 28% by mass of sodium lauryl ether sulphate (SLES), and optionally propylene oxide ethylene oxide monobutyl ether (B11/50).

[0103] A mixture 2, called a monomer premixture, comprising deionised water, is prepared in a beaker: [0104] monomer (a1), methacrylic acid (MAA), [0105] monomer (a2), ethyl acrylate (EA), [0106] monomer (a5), diallyl phthalate, [0107] optionally monomer (x), [0108] optionally 28% solution of sodium lauryl ether sulphate (SLES) or sodium lauryl sulphate (SLS), [0109] optionally an associative monomer (x), straight (C.sub.16—C.sub.18)-alkyl-(EO)25-methacrylate.

[0110] This premixture is stirred to form a monomer mixture.

[0111] An initiator solution is prepared comprising ammonium persulphate and deionised water. All reagents and amounts used are shown in Table 1.

[0112] The initiator solution and the monomer premixture are injected in parallel, over two hours, into the reactor heated to 85° C.±1° C. This mixture is baked for 30 min at 85° C.±1° C. and then cooled to room temperature.

[0113] The polymers according to the invention and the comparative polymer were prepared under these conditions by varying the monomer compositions of the monomer premixtures. The compositions of the copolymers obtained are shown in Table 1.

TABLE-US-00001 TABLE 1 Polymer Quantity (g) P1 CP1 Mixture 1 deionised water 400 400 SLS 2.60 0 SLES 0 6.17 Polyglykol B11/50 1.10 0 Premixture deionised water 173.70 175.00 SLS 1.81 0 SLES 0 4.29 Polyglykol B11/50 1.04 0 MAA (a1) 105.69 88.15 EA (a2) 191.28 176.36 diallyl phthalate (a5) 2.75 0.88 monomer (x) 0 22.96 Initiator deionised water 54.32 62.85 ammonium persulphate 0.58 0.41 Composition monomer (a1) (mol %) 38.98 32.51 monomer (a2) (mol %) 60.67 55.93 monomer (a5) (mol %) 0.35 0.11 monomer (x) (mol %) 0 0.52 Characteristics final solids content (% by weight) 30 29 particle size (nm) 74 75

Example 2

Preparation and Evaluation of Cosmetic Compositions (C1 to C8) according to the Invention and Comparative Compositions (CC1 to CC8)

[0114] In a beaker, the hydrophilic phase is prepared by mixing, under stirring using an Ika or Rayneri blade stirrer and motor, deionised water and a polymer (P1) according to the invention or a comparative polymer (C1) or comparative polymers of the prior art. The pH is adjusted to 7 by adding a 20% sodium hydroxide solution in water (to pH 5.5 for compositions CC6 and CC8).

[0115] The hydrophilic phase of the compositions according to the invention and of the comparative compositions is prepared under stirring at 700-1,000 rpm (except composition CC8 at 1,600-2,000 rpm).

[0116] The comparative polymers are polymer (CP1) from example 1 and the comparative polymers of the following prior art: [0117] polymer (CP2): Pemulen TR1 (Lubrizol-INCI: Acrylates/C.sub.10-30 alkyl acrylate crosspolymer), [0118] polymer (CP3): Rheomer SC Plus (Solvay-INCI: acrylates/beheneth-25 methacrylate copolymer).

[0119] Comparative composition (CC1) comprises polymer (P1) according to the invention and a surface-active compound (Gattefossé Emulium Delta—INCI: cethyl alcohol (and) glyceryl stearate (and) PEG75 stearate (and) ceteth-20 (and) steareth-20) whereas comparative composition (CC8) does not comprise any polymer and comprises a surface-active compound (Gattefossé Emulium Delta).

[0120] The lipophilic compounds of the lipophilic phase are: [0121] Caprylis (INCI: caprylic/capric triglyceride), [0122] commercial hydrogenated sunflower oil (INCI: Helianthus annuus (sunflower) seed oil), [0123] commercial liquid paraffin (INCI: Paraffinum liquidum), [0124] Floramac 10 (Floratech-INCI: Ethyl macadamiate), [0125] Gran sil GMD-3 (Grant Industries-INCI: dimethicone & poly silicone-11).

[0126] The ingredients and amounts are shown in Tables 2 and 3 along with the characteristics and properties of the cosmetic compositions prepared. The compositions are stable after one month at 40° C. after being visually assessed by absence of partial separation of the lipophilic phase dispersed on the surface of the hydrophilic phase.

[0127] Brookfield viscosity is measured at 20 rpm and 25° C.

[0128] To measure the particle size distribution of the dispersed lipophilic phase (D50 in %) in the hydrophilic phase, a Malvern Mastersizer 2000 device is used. D50% is the size for which 50% of the particle volume has a size that is smaller than this particular value.

[0129] To evaluate the water resistance of the cosmetic compositions, a Leneta contrast chart is placed on the composition using a 300 μm wedge and allowed to dry for 24 hours. Then, a few drops of deionised water are deposited on the composition film. If the composition film turns whitish, a redispersion phenomenon is taking place, which shows that the cosmetic composition is not stable. On the other hand, the absence of any colour change demonstrates the stability of the cosmetic composition.

TABLE-US-00002 TABLE 2 Composition according to the invention (g) C1 C2 C3 C4 hydrophilic phase: 76 74 72 74 deionised water hydrophilic phase: 4 6 8 6 P1 at 30% in water lipophilic phase: 20 20 20 60 Caprylis Viscosity (mPa .Math. s) 5,570 11,900 20,400 20,800 D50% (μm) 16.4 11.0 9.2 9.8 water resistance yes yes yes yes Composition according to the invention (g) C5 C6 C7 C8 hydrophilic phase: 74 74 74 74 deionised water hydrophilic phase: 6 6 6 6 P1 at 30% in water lipophilic phase: 20 0 0 0 hydrogenated sunflower oil lipophilic phase: 0 20 0 0 liquid paraffin lipophilic phase: 0 0 20 0 Floramac 10 lipophilic phase: 0 0 0 20 Gransil GMD-3 Viscosity (mPa .Math. s) 48,090 18,660 1,950 24,300 D50% (μm) 17.3 17.2 5.0 52.7 water resistance yes yes yes yes

TABLE-US-00003 TABLE 3 Comparative composition (g) CC1 CC2 CC3 CC4 hydrophilic phase: 72 76 74 72 deionised water hydrophilic phase: 6 0 0 0 P1 at 30% in water hydrophilic phase: 0 4 6 8 CP1 at 30% in water hydrophilic phase: 2 0 0 0 Emulium Delta lipophilic phase: 20 20 20 20 Caprylis Viscosity (mPa .Math. s) 32,200 6,920 29,000 47,600 D50% (μm) 5.7 10.9 5.0 4.3 water resistance no no no no Comparative composition (g) CC5 CC6 CC7 CC8 hydrophilic phase: 74 79.6 74 74 deionised water hydrophilic phase: 6 0 0 0 CP1 at 29% in water hydrophilic phase: 0 0.4 0 0 CP2 hydrophilic phase: 0 0 6 0 CP3 at 28% in water hydrophilic phase: 0 0 0 6 Emulium Delta lipophilic phase: 60 20 20 20 Caprylis Viscosity (mPa .Math. s) 44,400 9,660 60,400 2,300 D50% (μm) 7.0 32.2 6.5 17.8 water resistance no no no no

[0130] Thus, polymer (P1) according to the invention makes it possible to prepare cosmetic compositions that are water-resistant after application.

[0131] On the other hand, comparative polymer (CP1) comprising monomer (x) does not make it possible to obtain a cosmetic composition that is water-resistant after application.

[0132] Likewise, known comparative polymers (CP2) and (CP3) do not make it possible to obtain a cosmetic composition that is water-resistant after application.

[0133] Lastly, the use of a surface-active compound in the comparative cosmetic compositions, with or without polymer (P1) according to the invention, does not make it possible to obtain a cosmetic composition that is water-resistant after application.

Example 3

Preparation and Evaluation of a Sunscreen Formulation (F1) according to the Invention

[0134] A mixture 1 is prepared comprising: [0135] 2,2′,2″,2′″-(ethane-1,2-diyldinitrilo)-tetra-acetic (EDTA) acid (0.2 g), [0136] potassium sorbate (0.1 g) and [0137] water (63.8 g).

[0138] A mixture 2 is prepared by adding to mixture 1, polymer (P1) according to the invention (1.2 g) and a commercial rheology modifying agent (Coatex Rheostyl 90 N) (0.7 g). The pH is adjusted by adding, under stirring (700-1,000 rpm), sodium hydroxide 10% by weight in water (1 g).

[0139] A mixture 3 is prepared comprising: [0140] a fat-soluble organic UVA filter (BASF Uvinul A Plus Granular) (2 g), [0141] a fat-soluble organic UVB filter (Merck Eusolex 2292 KGaA) (6 g), [0142] a broad-spectrum fat-soluble organic UV filter (BASF Tinosorb S) (3 g) and [0143] emollient (BASF Cetiol B) (4 g).

[0144] A mixture 4 is prepared comprising: [0145] a water-soluble organic UVB filter (DSM Parsol HS) (2.5 g) and [0146] deionised water (15 g).

[0147] Mixture 3 is added to mixture 2 while under stirring, followed by a preservative (phenoxyethanol) (0.5 g).

[0148] The sunscreen formulation (F1) according to the invention is obtained with a pH of 6.7. It has a sun protection factor of 30, evaluated using a simulator (BASF Sunscreen Simulator via www. suns cre ensimul ator. b asf. com).

[0149] Its water resistance is 91%.

[0150] This water resistance is determined in vitro by measuring the evolution of the sun protection factor according to a spectrophotometric method (Kontron UV spectrophotometer equipped with an integration sphere and monochromator, capable of delivering a UV energy flow of between 290 and 400 nm) by measuring the UV energy flow through the formulation, expressed in energy transmission, and comparing this flow to the initial flow. The source and substrate are also taken into consideration.

[0151] The formulation (F1) is spread on a substrate (PMMA Sunplate plates Helioscience) with plastic laboratory syringes or with a micro-pipette with capillary and piston (Gilson Microman 250 μL) to obtain a homogeneous film of about 1.3 mg/cm.sup.2.

[0152] When the formulation has dried, the substrate is placed under running water that is temperature-controlled (29° C.) by a double boiler equipped with an adjustable-flow water circulation pump (Ika). Water is run (3 L/min) over the substrate for 15 minutes.

[0153] Then, the substrate is dried and measurements are taken with the spectrophotometer.

[0154] The sun protection factor (PF in vitro) is expressed based on the full residual UVB and UVA spectrum that traverses the same layer of formulation as that spread on the skin and corrected according to a spectral sunlight characteristic of the skin's reactivity according to the wavelength.

[0155] The average protection factor for the studied preparation was obtained by calculating the arithmetical mean of the protection factors in several trials. Water resistance is the SPF ratio in vitro before and after bathing; it must be greater than or equal to 50% for the formulation to be considered water-resistant.

[0156] The resulting 91% clearly demonstrates the very high water resistance of this oil-in-water sunscreen formulation prepared using the emulsifying polymer (P 1) alone.