WO2008006677A1

WO2008006677A1 - Fluid cosmetic composition with a water-soluble heat-induced gelling polymer, a continuous aqueous phase, an oily phase and organic uv-screening agent

Info

Publication number: WO2008006677A1
Application number: PCT/EP2007/056136
Authority: WO
Inventors: Jean-Thierry Simonnet; Florence L'alloret
Original assignee: LOreal SA
Current assignee: LOreal SA
Priority date: 2006-07-13
Filing date: 2007-06-20
Publication date: 2008-01-17
Anticipated expiration: 2009-01-13

Abstract

The invention relates to a fluid cosmetic composition for protecting keratin materials, and more particularly the skin and the hair, against the harmful effects of UV radiation, comprising, in a physiologically acceptable medium: a) at least one water-soluble heat-induced gelling polymer; b) at least one continuous aqueous phase; c) at least one oily phase in a concentration ranging from 1% to 70% by weight relative to the total weight of the composition, and d) at least one organic UV-screening agent. The invention relates to the use of at least one water- soluble heat-induced gelling polymer in a cosmetic composition as defined above, for the purpose of improving the photoprotective efficacy. The invention relates to the use of at least one water- soluble heat-induced gelling polymer in a cosmetic composition as defined above, for the purpose of improving the homogeneity of spreading on keratin materials such as the skin, the lips, the hair, the scalp, the eyelashes, the eyebrows and the nails.

Description

FLUID COSMETIC COMPOSITION WITH A WATER-SOLUBLE HEAT-INDUCED GELLING POLYMER, A CONTINUOUS AQUEOUS PHASE , AN OILY PHASE AND AN ORGANIC UV-SCREENING AGENT

5 The invention relates to fluid cosmetic compositions for protecting keratin materials, and more particularly the skin and the hair, against the harmful effects of UV radiation, comprising, in a physiologically acceptable medium, at least one water-soluble heat- 10 induced gelling polymer, at least one continuous aqueous phase, at least one oily phase and at least one organic UV- screening agent.

The invention relates to the use of at least one heat-

15 induced gelling polymer in a fluid cosmetic composition comprising, in a physiologically acceptable medium, at least one continuous aqueous phase, at least one oily phase and at least one agent for absorbing UV radiation, for the purpose of improving the

20 photoprotective efficacy.

The invention relates to the use of at least one heat- induced gelling polymer in a fluid cosmetic composition comprising, in a physiologically acceptable medium, at

25 least one continuous aqueous phase, at least one oily phase and at least one agent for absorbing UV radiation, for the purpose of improving the homogeneity and the spreading on keratin materials such as the skin, the hair, the scalp, the eyelashes, the eyebrows

30 and the nails.

Light radiation with wavelengths of between 280 and 400 nm permits tanning of the human epidermis; rays with wavelengths of between 280 and 320 nm, which are 35 known as UVB rays, cause skin burns and erythema that may harm the development of a tan. Rays with wavelengths of between 320 and 400 nm, which are known as UVA rays, are liable to induce impairment in the skin, especially with loss of elasticity and the appearance of wrinkles, leading to premature ageing.

UVA and UVB rays should thus be screened out, and cosmetic compositions for protecting the human epidermis, containing UV- screening agents and having a fluid texture to allow easy application to the skin, currently exist. However, these fluid compositions have the aesthetic drawback of spreading non-uniformly on the skin, the hair or keratin materials in general, and the technical drawback of having limited screening efficacy. This is reflected by a significant increase in the content of screening species in the composition, which runs counter to improving the harmlessness, the cosmeticity, the environmental friendliness and to achieving an economic saving.

This problem is mainly due to poor spreading caused by poor wetting of the skin, which is hydrophobic, and/or to rapid dewetting of the skin.

It thus appears necessary to have available fluid compositions that spread uniformly on the skin and that ensure optimum screening efficacy.

The Applicant has discovered, surprisingly, that fluid aqueous antisun compositions containing at least one water-soluble heat-induced gelling polymer and at least one agent for absorbing UV radiation satisfy this need.

Thus, one subject of the present invention is a fluid composition comprising, in a physiologically acceptable medium: a) at least one water-soluble heat-induced gelling polymer; b) at least one oily phase in a concentration ranging from 1% to 70% by weight relative to the total weight of the composition; c) at least one continuous aqueous phase,- d) at least one organic UV- screening agent. A subject of the present invention is also the use of at least one water-soluble heat-induced gelling polymer in a fluid composition comprising, in a physiologically acceptable medium, at least one continuous aqueous phase, at least one oily phase and at least one agent for absorbing UV radiation, for the purpose of increasing the sun protection factor (SPF) .

The invention relates to the use of at least one water- soluble heat-induced gelling polymer in a cosmetic composition comprising, in a physiologically acceptable medium, at least one continuous aqueous phase, at least one oily phase and at least one agent for absorbing UV radiation, for the purpose of improving the homogeneity of spreading on keratin materials such as the skin, the lips, the hair, the scalp, the eyelashes, the eyebrows and the nails.

The sun protection factor (SPF) is expressed mathematically as the ratio of the dose of UV radiation necessary to reach the erythema- forming threshold with the UV- screening agent, to the dose of UV radiation necessary to reach the erythema- forming threshold without UV-screening agent.

The expression "agent for absorbing UV radiation" means any organic or mineral compound capable of screening out UV radiation via any physical phenomenon such as scattering, diffraction, reflection and absorption.

The term "fluid composition" preferably means that the viscosity of the composition, measured using a Rheomat 180 viscometer at 25⁰C and at a spin speed of 200 rpm, is less than or equal to 5 Pa . s .

The expression "composition comprising at least one continuous aqueous phase" means an oil-in-water or water-in-oil-in-water emulsion. These emulsions may be stabilized via any technique known to those skilled in the art: surfactants that do or do not form a lamellar phase at the surface of oil globules,- amphiphilic polymers (e.g.: AQ from Eastman (OA 97045) , Aristoflex from Clariant, Viscophobe DB 1000 from Dow Chemical, Pemulen from Noveon, and Aculyn 22, 28 and 88 from Rohm & Haas) ,- solid particles.

The term "physiologically acceptable medium" means a non-toxic medium that may be applied to the skin, the lips, the hair, the eyelashes, the eyebrows and the nails. The composition of the invention may especially constitute a cosmetic or dermatological composition.

Preferentially, the heat-induced gelling polymers according to the invention are water-soluble and comprise water-soluble units and units having in water a lower critical solution temperature, LCST, the heat- induced demixing temperature in aqueous solution of the said units with an LCST being from 5 to 4O⁰C for a mass concentration in water of 1% of the said units and the concentration of the said polymer in the said composition being such that its gel point is in the range from 5 to 4O⁰C.

The term "water-soluble polymer" generally means a polymer that is soluble in water, at a temperature of from 5 to 8O⁰C, to a proportion of at least 10 g/1 and preferably of at least 20 g/1. However, the term "water-soluble polymer" also means a polymer not necessarily having the solubility mentioned above, but which, in aqueous solution at 1% by weight, from 5 to 8O⁰C, allows the production of a macroscopically homogeneous and transparent solution, i.e. a solution with a maximum light transmittance value, irrespective of the wavelength between 400 and 800 nm, through a sample 1 cm thick, of at least 85% and preferably of at least 90 % .

The term "water-soluble units" generally means that these units are soluble in water, at a temperature of from 5 to 8O⁰C, to a proportion of at least 10 g/1 and preferably of at least 20 g/1. However, the term "water-soluble units" also means units not necessarily having the solubility mentioned above, but which, in aqueous solution at 1% by weight, from 5 to 8O⁰C, allow the production of a macroscopically homogeneous and transparent solution, i.e. a solution with a maximum light transmittance value, irrespective of the wavelength between 400 and 800 nm, through a sample 1 cm thick, of at least 85% and preferably of at least 90%. These water-soluble units have no heat-induced demixing temperature of LCST type .

In this respect, it is useful to recall that the expression "units with an LCST" preferably means units whose solubility in water is modified beyond a certain temperature. These are units with a heat-induced demixing temperature (or cloud point) defining their region of solubility in water. The minimum demixing temperature obtained as a function of the concentration of polymer consisting solely of units with an LCST is known as the "LCST" (Lower Critical Solution Temperature) . For each concentration of polymer with an LCST, a heat-induced solution temperature is observed. It is higher than the LCST, which is the minimum point of the curve. Below this temperature, the polymer is soluble in water, and above this temperature, the polymer loses its solubility in water.

These units with an LCST of the polymer preferably have, according to the invention, a heat-induced demixing temperature of from 5 to 4O⁰C for a mass concentration in water of 1% by weight of the said units with an LCST. More preferentially, the heat-induced demixing temperature in aqueous solution of the units with an LCST of the polymer is from 10 to 35⁰C for a mass concentration in water of 1% of the said units with an LCST.

More preferentially, the polymer concentration is such that the gel point is in the range from 10 to 35⁰C.

The polymer having the structure described above with water-soluble units and specific units with an LCST defined above has in aqueous solution gelation properties beyond a critical temperature, or heat- induced gelling properties.

These heat-induced gelling properties observed beyond the demixing temperature of the chains with an LCST are described especially in the following documents: [1] D. Hourdet et al . , Polymer, 1994, Vol. 35, No. 12, pages 2624-2630.

[2] F. L'Alloret et al . , Coll. Polym. Sci . , 1995, Vol.

273, No. 12, pages 1163-1173.

[3] F. L'Alloret, Revue de l'Institut Frangais du Petrole [Review of the French Petroleum Institute], 1997, Vol. 52, No. 2, pages 117-128.

They are due to the combination of the chains with an LCST within hydrophobic microdomains beyond their demixing temperature, thus forming crosslinking nodes between the main chains.

These gelling properties are observed when the polymer concentration is sufficient to allow interactions between units with an LCST borne by different macromolecules . The minimum concentration required, known as the "critical aggregation concentration" , or CAC, is evaluated by rheological measurements: it is the concentration at and above which the viscosity of an aqueous solution of the polymers of the invention becomes higher than the viscosity of a solution of the equivalent polymer not comprising chains with an LCST.

Beyond the CAC, the polymers of the invention have gelling properties when the temperature becomes higher than a critical value, known as the "gel point", or T_gei. According to the literature data, there is good agreement between T_gei and the demixing temperature of the chains with an LCST, under the same concentration conditions. The gel point of an aqueous solution of a polymer of the invention is determined by rheological measurements: it is the temperature at and above which the viscosity of a solution of a polymer of the invention becomes higher than the viscosity of a solution of the equivalent polymer not comprising chains with an LCST.

The polymers of the invention are preferably characterized by a specific gel point generally of from 5 to 4O⁰C and preferably from 10 to 35⁰C, for a concentration by mass in water equal to, for example, 2% by weight.

The polymers used in the invention may be block polymers or grafted polymers, which comprise, on the one hand, water-soluble units and, on the other hand, units with an LCST as defined above.

It is pointed out that, in the present text, the water- soluble units or the units with an LCST of the polymers used according to the invention are defined as not including the groups linking together, on the one hand, the said water-soluble units and, on the other hand, the said units with an LCST.

The said linking groups are derived from the reaction, during the preparation of the polymer, of the reactive sites borne, on the one hand, by the precursors of the said water-soluble units and, on the other hand, by the precursors of the said units with an LCST.

The polymers used in the context of the invention may thus be block polymers comprising, for example, blocks consisting of water-soluble units alternating with blocks with an LCST.

These polymers may also be in the form of grafted polymers whose backbone is formed from water-soluble units, the said backbone bearing grafts consisting of units with an LCST.

The said polymers may be partially crosslinked.

These water-soluble units may be totally or partially obtained by polymerization, especially free-radical polymerization, or by polycondensation, or may consist totally or partially of existing natural or modified natural polymers .

By way of example, the water-soluble units may be totally or partially obtained by polymerization, especially free-radical polymerization, of at least one monomer chosen from the following monomers: - (meth) acrylic acid;

- vinyl monomers of formula (I) below:

in which:

- R is chosen from H, -CH₃, -C₂H₅ and -C₃H₇, and - X is chosen from:

- alkyl oxides of -OR' type in which R' is a linear or branched, saturated or unsaturated hydrocarbon-based radical containing from 1 to 6 carbon atoms, optionally substituted with at least one halogen atom (iodine, bromine, chlorine or fluorine); a sulfonic (-SO₃ ^"), sulfate (-SO₄ ^"), phosphate (-PO₄H₂); hydroxyl (-0H); primary amine (-NH₂); secondary amine (-NHRi), tertiary amine (-NR₁R₂) or quaternary amine (-N⁺RiR₂R₃) group with Ri, R₂ and R₃ being, independently of each other, a linear or branched, saturated or unsaturated hydrocarbon-based radical containing 1 to 6 carbon atoms, with the proviso that the sum of the carbon atoms of R' + R₁ + R₂ + R₃ does not exceed 7; and

- -NH₂, -NHR₄ and -NR₄R₅ groups in which R₄ and R₅ are, independently of each other, linear or branched, saturated or unsaturated hydrocarbon-based radicals containing 1 to 6 carbon atoms, with the proviso that the total number of carbon atoms of R₄ + R₅ does not exceed 7, the said R₄ and R₅ optionally being substituted with a halogen atom (iodine, bromine, chlorine or fluorine); a hydroxyl (-0H); sulfonic (-SO₃ ^") ; sulfate (-SO₄ ^") ; phosphate (-PO₄H₂) ; primary amine (-NH₂); secondary amine (-NHR₁), tertiary amine (-NR₁R₂) and/or quaternary amine (-N⁺R₁R₂R₃) group with R₁, R₂ and R₃ being, independently of each other, a linear or branched, saturated or unsaturated hydrocarbon-based radical containing 1 to 6 carbon atoms, with the proviso that the sum of the carbon atoms of R₄ + R₅ + R₁ + R₂ + R₃ does not exceed 7;

- maleic anhydride;

- itaconic acid; - vinyl alcohol of formula CH₂=CHOH;

- vinyl acetate of formula CH₂=CH-OCOCH₃;

- N-vinyllactams such as N-vinylpyrrolidone, N-vinyl- caprolactam and N-butyrolactam;

- vinyl ethers of formula CH₂=CHOR₆ in which R₆ is a linear or branched, saturated or unsaturated hydrocarbon-based radical containing from 1 to 6 carbons ;

- water-soluble styrene derivatives, especially styrene sulfonate; - dimethyldiallylammonium chloride; and

- vinylacetamide.

The polycondensates and natural or modified natural polymers which may constitute all or part of the water- soluble units are chosen from one or more of the following components:

- water-soluble polyurethanes,

- xanthan gum, especially the product sold under the names Keltrol T and Keltrol SF by Kelco; or Rhodigel SM and Rhodigel 200 from Rhodia;

- alginates (Kelcosol from Monsanto) and derivatives thereof such as propylene glycol alginate (Kelcoloid LVF from Kelco) ; - cellulose derivatives and especially carboxymethyl- cellulose (Aquasorb A500, Hercules) , hydroxypropyl - cellulose, hydroxyethylcellulose and quaternized hydroxyethylcellulose; galactomannans and derivatives thereof, such as Konjac gum, guar gum, hydroxypropyl guar, hydroxypropyl guar modified with sodium methylcarboxylate groups (Jaguar XC97-1, Rhodia) , guar hydroxypropyl - trimethylammonium chloride.

Mention may also be made of polyethyleneimine .

The water-soluble units preferably have a molar mass ranging from 1000 g/mol to 5 000 000 g/mol when they constitute the water-soluble backbone of a grafted polymer.

These water-soluble units preferably have a molar mass ranging from 500 g/mol to 100 000 g/mol when they constitute a block of a multiblock polymer.

The units with an LCST of the polymers used in the invention may be defined as being units whose water solubility is modified beyond a certain temperature. They are units with a heat-induced demixing temperature (or cloud point) defining their region of solubility in water. The minimum demixing temperature obtained as a function of the polymer concentration is referred to as the "LCST" (Lower Critical Solution Temperature) . For each polymer concentration, a heat-induced demixing temperature is observed; it is higher than the LCST, which is the minimum point of the curve. Below this temperature, the polymer constituting the unit with an LCST is soluble in water; above this temperature, the polymer constituting the unit with an LCST loses its solubility in water.

Some of these polymers with an LCST are especially described in the following articles: - Taylor et al . , Journal of Polymer Science, part A: Polymer Chemistry, 1975, 13, 2551;

- J. Bailey et al . , Journal of Applied Polymer Science, 1959, 1,56;

- Heskins et al . , Journal of Macromolecular Science, Chemistry A2, 1968, Vol. 8, 1441.

The expression "soluble in water at a temperature T" means that the units have a solubility at T of at least 1 g/1 and preferably of at least 2 g/1.

The measurement of the LCST may be performed visually: the temperature at which the cloud point of the aqueous solution appears is determined; this cloud point is reflected by the opacification of the solution, or the loss of transparency.

In general, a transparent composition will have a maximum light transmittance value, irrespective of the wavelength between 400 and 800 nm, through a sample 1 cm thick, of at least 85% and preferably of at least 90%.

The transmittance may be measured by placing a sample 1 cm thick in the light beam of a spectrophotometer working at the wavelengths of the light spectrum.

The units with an LCST of the polymers used in the invention may consist of one or more polymers chosen from the following polymers: polyethers such as polypropylene oxide (PPO) or statistical copolymers of ethylene oxide (EO) and of propylene oxide (PO) ,

- polyvinyl methyl ethers, - polymeric and copolymeric N- substituted acrylamide derivatives containing units with an LCST, such as poly-N-isopropylacrylamide (NIPAM) and poly-N- ethylacrylamide,- and

- polyvinylcaprolactam and vinylcaprolactam copolymers.

Preferably, the units with an LCST consist of polypropylene oxide (PPO)_n where n is an integer from 10 to 70, or of statistical copolymers of ethylene oxide (EO) and of propylene oxide (PO) , represented by the formula:

(EO)_1n(PO)_n in which m is an integer ranging from 1 to 40 and preferably from 2 to 20, and n is an integer ranging from 10 to 60 and preferably from 20 to 50.

Preferably, the molar mass of these units with an LCST is from 500 to 5300 g/mol and more preferably from 1500 to 4000 g/mol.

It has been found that the random distribution of the EO and PO units is reflected by the existence of a lower critical solution temperature, beyond which a macroscopic phase separation is observed. This behaviour is different from that of block (EO) (PO) copolymers, which form micelles beyond a critical temperature known as the micellization temperature (microscopic aggregation) .

The units with an LCST may thus especially be polypropylene oxides such as the Polyglycols P3000 and P4000 from Dow Chemical, or amino, especially monoamine diamino or triamino, statistical copolymers of ethylene oxide and of propylene oxide. Before reaction, these polymers bear reactive sites, in this case amino groups, reacting with the reactive sites of the water-soluble polymers, for example carboxyl groups, to give the final polymer used in the invention. In the final polymer, the water-soluble units are linked to the units with an LCST via linking groups derived from the reaction of the reactive sites or groups borne, respectively, by the units with an LCST and the precursors of the water-soluble units. These linking groups will be, for example, amide, ester, ether or urethane groups.

Among these commercially available polymers with an LCST, mention may be made of the copolymers sold under the name Jeffamine by Huntsman, and especially Jeffamine XTJ-507 (M-2005) , Jeffamine D-2000 and Jeffamine XTJ-509 (or T-3000) .

The units with an LCST may also be derived from random EO/PO copolymers containing OH end groups, such as those sold under the name Polyglycols P41 and BIl by Clariant .

Polymeric and copolymeric N- substituted acrylamide derivatives containing units with an LCST, and also polyvinylcaprolactam and vinylcaprolactam copolymers, may also be used in the invention as units with an LCST.

As examples of polymeric and copolymeric N- substituted acrylamide derivatives containing units with an LCST, mention may be made of poly-N-isopropylacrylamide, poly-N-ethylacrylamide and copolymers of N- isopropylacrylamide (or of N-ethylacrylamide) and of a vinyl monomer chosen from the monomers having the formula (I) given above, maleic anhydride, itaconic acid, vinylpyrrolidone, styrene and its derivatives, dimethyldiallylammonium chloride, vinylacetamide, vinyl ethers and vinyl acetate derivatives. The molar mass of these polymers is preferably from 1000 g/mol to 500 000 g/mol and preferably from 2000 to 50 000 g/mol.

These polymers may be synthesized by free-radical polymerization using a pair of initiators such as aminoethanethiol hydrochloride, in the presence of potassium persulfate, so as to obtain precursor oligomers with a reactive amino end group.

As examples of vinylcaprolactam copolymers, mention may be made of copolymers of vinylcaprolactam and of a vinyl monomer of formula (I) given above, or of a monomer chosen from maleic anhydride, itaconic acid, vinylpyrrolidone, styrene and its derivatives, dimethyldiallylammonium chloride, vinylacetamide, vinyl alcohol, vinyl acetate, vinyl ethers and vinyl acetate derivatives .

The molar mass of these vinylcaprolactam polymers or copolymers is generally from 1000 g/mol to 500 000 g/mol and preferably from 2000 to 50 000 g/mol.

These compounds may be synthesized by free-radical polymerization using a pair of initiators such as aminoethanethiol hydrochloride, in the presence of potassium persulfate, so as to obtain units with an LCST containing a reactive amino end group.

The mass proportion of the units with an LCST in the final polymer is preferably from 5% to 70%, especially from 10% to 60% and particularly from 20% to 50% by weight relative to the final polymer.

It has been seen hereinabove that the heat-induced demixing temperature of the said units with an LCST of the polymer used in the invention is from 5 to 4O⁰C and preferably from 10 to 35⁰C, for a concentration by mass in water of 1% by weight of the said units with an LCST .

The polymers used in the context of the invention may be readily prepared by a person skilled in the art on the basis of his general knowledge, using grafting, copolymerization or coupling reaction processes.

When the final polymer is in the form of a grafted polymer, especially having a water-soluble backbone with side chains or grafts with an LCST, it is possible to prepare it by grafting units with an LCST containing at least one reactive end group or reactive site, especially an amino end group or site, onto a water- soluble polymer forming the backbone, bearing at least 10% (on a molar basis) of reactive groups such as carboxylic acid functions. This reaction may be carried out in the presence of a carbodiimide such as dicyclohexylcarbodiimide or 1- (3-dimethylaminopropyl) - 3-ethylcarbodiimide hydrochloride, in a solvent such as N-methylpyrrolidone or water.

Another possibility for preparing grafted polymers consists in copolymerizing, for example, a macromonomer with an LCST (chain with an LCST described above with a vinyl end group) and a water-soluble vinyl monomer such as acrylic acid or vinyl monomers of formula (I) .

When the final polymer is in the form of a block polymer, it is possible to prepare it by coupling between water-soluble units and units with an LCST, these units having complementary reactive sites at each end.

In the case of grafting processes and coupling processes, the reactive sites of the units with an LCST may be amine functions, especially monoamine, diamine or triamine functions, and OH functions. In this case, the reactive sites of the water-soluble units may be carboxylic acid functions. The groups linking the water-soluble units and the units with an LCST will thus be, for example, amide groups or ester groups.

The heat-induced gelling polymers in accordance with the invention may be chosen from those described in the following patents and patent applications: patent applications EP 1 307 501, EP 1 355 990, EP

1 355 625, FR 2 856 923, EP 1 493 774 and WO 04/006872, patents US 6 878 754 and US 6 689 856; patent applications EP 1 407 791, EP 1 416 044, FR 2 788 008, WO 03/008462, FR 2 694 939, EP 0 629 649, US 6 645 476, WO 97/00275, WO 98/06438, WO 98/29487, WO 98/48768, WO 98/50005, WO 00/07603, WO 02/076392, FR 2 820 976, WO 00/35961, WO 02/032560, EP 0 692 506, US 6 870 012, WO 03/106536, WO 00/38651, WO 00/00222, WO 01/41735, US2003/0099709, GB 2 408 510.

Heat-induced gelling polymers that are particularly advantageous may be chosen from:

(1) polyurethanes comprising polyethylene oxide/polypropylene oxide/polyethylene oxide (or PEO-PPO-PEO) groups such as those described in patent applications EP-I 407 791 (Example 1 describes a polyurethane derived from the polycondensation of Pluronic F-127 with hexamethylene diisocyanate) , EP-A-692 506, FR-A-

2 840 907, WO 03/106 536, US-A-2005/175 573 and US-A- 5 702 717.

Such polyurethanes are obtained in a known manner by polycondensation of diisocyanates and of heat-sensitive PEO-PPO-PEO triblock diols and are especially described in the abovementioned patent applications.

Diisocyanates that may be mentioned include aliphatic diisocyanates, for instance ethylene diisocyanate, hexamethylene diisocyanate, decamethylene diisocyanate, and also methylene-4 , 4 ' -bis (dicyclohexyl) diisocyanate, diphenylmethane 4 , 4 ' -diisocyanate, xylylene diiso- cyanate, phenylene diisocyanate, tolylene diisocyanate and dimethyl diphenylene diisocyanate.

PEO-PPO-PEO triblock diols used may correspond to formula (I) below:

HO- (CH₂-CH₂-O)_x- (CH₂-CH(CH₃) -0)_y_ (CH₂-CH₂-O)_x-H with 20<x<120 and 20<y<120 such as the Pluronic products, especially Pluronic F- 127.

The polyurethane may comprise urea and/or allophanate groups, as described in patent applications WO 03/106 536 and US-A-5 702 717.

The polycondensation may also be performed in the presence of other reactive compounds, for instance diols comprising one or more carboxylic acid groups or a tertiary amine group (especially aminomethyl) or alternatively such as monohydroxylated polyethylene oxides. The polycondensation may especially be performed in the presence of water.

The polyurethane may be linear or branched.

(2) multiblock copolymers comprising a poly-N- isopropylacrylamide block and n-butyl acrylate randomly distributed and a polyethylene glycol block, such as those described in patent application EP-A-I 407 791.

The product sold under the trade name TGP-20 by the company Mebiol may be used in particular.

(3) copolymers of acrylamidomethylpropanesulfonic acid (or AMPS) such as those described in patents US 6 645 476 and US 6 689 856, and also the salts thereof (in particular sodium or ammonium salts) and of a macromonomer of an ester of (meth) acrylic acid and of alkoxylated C₂-C₄ alkyl (in particular ethylene oxide (EO) and/or propylene oxide (PO) (especially containing 1 to 500, more preferentially from 3 to 50 and better still 7 to 30 alkoxylated alkyl units) .

Such macromonomers may also be derived from amino EO/PO statistical copolymers, especially mono-, di- or triamino copolymers of the Jeffamine type from Huntsman, and especially Jeffamine XTJ-507 (M-2005) , Jeffamine D-2000 and Jeffamine XTJ-509 (or T-3000) .

Such macromonomers may also be derived from EO/PO statistical copolymers with OH end groups, such as those sold under the name Polyglycols P41 and BIl by Clariant .

The copolymer of polyacrylamido-2-methylpropanesulfonic acid (AMPS) neutralized with aqueous ammonia (40% by weight relative to the total weight of the polymer) and of a polyether methacrylate macromonomer (60% by weight) in which the polyether is a PEO/PPO statistical copolymer comprising 5.5 mol of ethylene oxide (EO) units and 31 mol of propylene oxide units.

(4) copolymers such as those described in patent application EP 1 307 501, consisting of a polyacrylic acid (PAA) backbone bearing side chains or grafts consisting of units with an LCST chosen from: (i) those of the type such as statistical copolymers of ethylene oxide (EO) and of propylene oxide (PO) , represented by the formula: (EO)_1n(PO)_n in which m is an integer ranging from 1 to 40 and preferably from 2 to 20, and n is an integer ranging from 10 to 60 and preferably from 20 to 50; the molar mass of these units with an LCST preferably being from 500 to 5300 g/mol and more preferentially from 1500 to 4000 g/mol;

(ii) poly-N-isopropylacrylamide polymers whose molar mass is preferably from 1000 g/mol to 500 000 g/mol and more preferentially from 2000 to 50 000 g/mol. The content of heat-induced gelling polymer in the compositions according to the invention ranges preferably from 0.01% to 20% and better still from 0.1% to 10% relative to the total weight of the composition.

The organic UV- screening agents in accordance with the invention are chosen especially from cinnamic derivatives; anthranilates,- salicylic derivatives; dibenzoylmethane derivatives; camphor derivatives; benzophenone derivatives; diphenylacrylate derivatives; triazine derivatives; benzotriazole derivatives; benzalmalonate derivatives; benzimidazole derivatives; imidazolines; bis-benzazolyl derivatives as described in patents EP 669 323 and US 2 463 264; p-aminobenzoic acid (PABA) derivatives; methylenebis (hydroxyphenylbenzotriazole) derivatives as described in patent applications US 5 237 071, US 5 166 355, GB 2 303 549, DE 197 26 184 and EP 893 119; benzoxazole derivatives as described in patent applications EP 0 832 642, EP 1 027 883, EP 1 300 137 and DE 101 62 844; screening polymers and screening silicones such as those described especially in patent application WO 93/04665; α-alkylstyrene-based dimers, such as those described in patent application DE 198 55 649; 4 , 4 -diarylbutadienes such as those described in patent applications EP 0 967 200, DE 197 46 654, DE 197 55 649, EP-A-I 008 586, EP 1 133 980 and EP 133 981, and mixtures thereof.

As examples of additional organic photoprotective agents, mention may be made of those denoted hereinbelow under their INCI name:

Cinnamic derivatives:

Ethylhexyl methoxycinnamate sold in particular under the trade name Parsol MCX by Hoffmann LaRoche, Isopropyl methoxycinnamate, Isoamyl methoxycinnamate sold under the trade name Neo Heliopan E 1000 by Haarmann and Reimer, Cinoxate,

DEA methoxycinnamate, Diisopropyl methylcinnamate,

Glyceryl ethylhexanoate dimethoxycinnamate .

Dibenzoylmethane derivatives:

Butylmethoxydibenzoylmethane sold especially under the trade name Parsol 1789 by Hoffmann LaRoche, Isopropyldibenzoylmethane .

para-Aminobenzoic acid derivatives: PABA, Ethyl PABA,

Ethyl dihydroxypropyl PABA,

Ethylhexyl dimethyl PABA sold in particular under the name Escalol 507 by ISP,

Glyceryl PABA, PEG-25 PABA sold under the name Uvinul P25 by BASF.

Salicylic derivatives:

Homosalate sold under the name Eusolex HMS by Rona/EM Industries, Ethylhexyl salicylate sold under the name Neo Heliopan OS by Haarmann and Reimer,

Dipropylene glycol salicylate sold under the name Dipsal by Scher, TEA salicylate sold under the name Neo Heliopan TS by Haarmann and Reimer.

Diphenylacrylate derivatives:

Octocrylene sold in particular under the trade name Uvinul N539 by BASF, Etocrylene sold in particular under the trade name Uvinul N35 by BASF. Benzophenone derivatives:

Benzophenone-1 sold under the trade name Uvinul 400 by

BASF,

Benzophenone-2 sold under the trade name Uvinul D50 by BASF,

Benzophenone-3 or Oxybenzone sold under the trade name

Uvinul M40 by BASF,

Benzophenone-4 sold under the trade name Uvinul MS40 by

BASF, Benzophenone- 5 ,

Benzophenone-6 sold under the trade name HeIisorb 11 by

Norquay,

Benzophenone-8 sold under the trade name Spectra-Sorb

UV-24 by American Cyanamid, Benzophenone- 9 sold under the trade name Uvinul DS-49 by BASF,

Benzophenone- 12 n-hexyl 2- (4-diethylamino-2-hydroxybenzoyl) benzoate .

Benzylidenecamphor derivatives:

3-Benzylidenecamphor manufactured under the name Mexoryl SD by Chimex,

4 -Methylbenzylidenecamphor sold under the name Eusolex 6300 by Merck, Benzylidenecamphorsulfonic acid manufactured under the name Mexoryl SL by Chimex,

Camphor benzalkonium methosulfate manufactured under the name Mexoryl SO by Chimex, Terephthalylidenedicamphorsulfonic acid manufactured under the name Mexoryl SX by Chimex,

Polyacrylamidomethylbenzylidenecamphor manufactured under the name Mexoryl SW by Chimex.

Phenylbenzimidazole derivatives: Phenylbenzimidazolesulfonic acid sold in particular under the trade name Eusolex 232 by Merck, Disodium phenyl dibenzimidazole tetrasulfonate sold under the trade name Neo Heliopan AP by Haarmann and Reimer . Phenylbenzotriazole derivatives:

Drometrizole trisiloxane sold under the name Silatrizole by Rhodia Chimie, Methylenebis (benzotriazolyl) tetramethylbutylphenol sold in solid form under the trade name MIXXIM BB/100 by Fairmount Chemical, or in micronized form as an aqueous dispersion under the trade name Tinosorb M by Ciba Specialty Chemicals.

Triazine derivatives: bis-Ethylhexyloxyphenol Methoxyphenyl Triazine sold under the trade name Tinosorb S by Ciba Geigy, Ethylhexyl triazone sold in particular under the trade name Uvinul Tl50 by BASF,

Diethylhexyl butamido triazone sold under the trade name Uvasorb HEB by Sigma 3V,

2,4,6-tris (diisobutyl 4 ' -aminobenzalmalonate) -s- triazine the symmetrical triazine screening agents described in patent US 6 225 467, patent application WO 2004/085 412

(see compounds 6 and 9) or the document "Symmetrical

Triazine Derivatives" IP.COM Journal, IP.COM INC WEST

HENRIETTA, NY, US (20 September 2004) , especially 2, 4, 6-tris (biphenyl) -1, 3, 5-triazines (in particular 2 , 4 , 6-tris (biphenyl-4-yl-l , 3 , 5-triazine) and 2,4,6- tris (terphenyl) -1 , 3 , 5-triazine which is also mentioned in patent applications WO 06/035 000, WO 06/034 982, WO 06/034 991, WO 06/035 007, WO 2006/034 992 and WO 2006/034 985.

Anthranilic derivatives:

Menthyl anthranilate sold under the trade name Neo Heliopan MA by Haarmann and Reimer.

Imidazoline derivatives:

Ethylhexyldimethoxybenzylidenedioxoimidazoline propionate . Benzalmalonate derivatives:

Polyorganosiloxane containing benzalmalonate functions, for instance Polysilicone-15 , sold under the trade name Parsol SLX by Hoffmann LaRoche

4 , 4-Diarylbutadiene derivatives:

1, 1-Dicarboxy (2, 2' -dimethylpropyl) -4, 4-diphenyl- butadiene

Benzoxazole derivatives:

2 , 4-Bis [5- ( 1 -dimethylpropyl ) benzoxazol-2 -yl (4-phenyl) - imino] -6- (2-ethylhexyl) imino-1 , 3 , 5-triazine sold under the name Uvasorb K2A by Sigma 3V and mixtures thereof .

The preferential additional organic photoprotective agents are chosen from:

Ethylhexyl Methoxycinnamate,

Ethylhexyl salicylate, Homosalate,

Octocrylene,

Phenylbenzimidazolesulfonic acid,

Benzophenone-3 ,

Benzophenone-4 , Benzophenone- 5 , n-Hexyl 2- (4-diethylamino-2-hydroxybenzoyl) benzoate,

4-Methylbenzylidenecamphor,

Terephthalylidenedicamphorsulfonic acid,

Disodium phenyldibenzimidazoletetrasulfonate, Methylenebis (benzotriazolyl) tetramethylbutylphenol , bis-Ethylhexyloxyphenol Methoxyphenyl Triazine,

Ethylhexyl Triazone,

Diethylhexyl Butamido Triazone,

2,4,6-tris (biphenyl-4-yl) -1,3, 5-triazine, 2,4,6-tris (terphenyl) -1,3, 5-triazine,

Drometrizole trisiloxane,

Polysilicone-15 ,

1 , 1-Dicarboxy (2,2' -dimethylpropyl) -4 , 4-diphenyl- butadiene, 2 , 4-Bis [5-1 (dimethylpropyl) benzoxazol-2-yl (4- phenyl) imino] -6- (2-ethylhexyl) imino-1 ,3,5-triazine, and mixtures thereof .

The compositions according to the invention may also comprise inorganic UV-screening agents. These agents are chosen from pigments, with a mean primary particle size generally of between 5 nm and 100 nm and preferably between 10 nm and 50 nm, of coated or uncoated metal oxides, for instance titanium oxide (amorphous or crystallized in rutile and/or anatase form) , iron oxide, zinc oxide, zirconium oxide or cerium oxide pigments, which are all UV-photoprotective agents that are well known per se . Such standard coating agents are moreover alumina and/or aluminium stearate. Such coated or uncoated metal oxide pigments are described in particular in patent applications EP 518 772 and EP 518 773.

The pigments may be coated or uncoated.

The coated pigments are pigments that have undergone one or more surface treatments of chemical, electronic, mechanochemical and/or mechanical nature with compounds as described, for example, in Cosmetics & Toiletries, February 1990, Vol. 105, pp. 53-64, such as amino acids, beeswax, fatty acids, fatty alcohols, anionic surfactants, lecithins, sodium, potassium, zinc, iron or aluminium salts of fatty acids, metal alkoxides (of titanium or of aluminium), polyethylene, silicones, proteins (collagen, elastin) , alkanolamines, silicon oxides, metal oxides or sodium hexametaphosphate .

As is known, silicones are organosilicon polymers or oligomers of linear or cyclic, branched or crosslinked structure, of variable molecular weight, obtained by polymerization and/or polycondensation of suitably functionalized silanes, and consist essentially of a repetition of main units in which the silicon atoms are linked together via oxygen atoms (siloxane bond) , optionally substituted hydrocarbon-based radicals being directly attached via a carbon atom to the said silicon atoms .

The term "silicones" also includes the silanes required for their preparation, in particular alkyl silanes.

The silicones used for coating the pigments that are suitable for the present invention are preferably chosen from the group containing alkyl silanes, polydialkylsiloxanes and polyalkylhydrogenosiloxanes . Even more preferentially, the silicones are chosen from the group containing octyltrimethylsilane, polydimeth- ylsiloxanes and polymethylhydrogenosiloxanes .

Needless to say, before being treated with silicones, the metal oxide pigments may have been treated with other surface agents, in particular with cerium oxide, alumina, silica, aluminium compounds or silicon compounds, or mixtures thereof.

The coated pigments are more particularly titanium oxides that have been coated: - with silica, such as the product Sunveil from the company Ikeda,

- with silica and iron oxide, such as the product Sunveil F from the company Ikeda, with silica and alumina, such as the products Microtitanium Dioxide MT 500 SA and Microtitanium

Dioxide MT 100 SA from the company Tayca, Tioveil from the company Tioxide and Mirasun TiW 60 from the company

Rhodia,

- with alumina, such as the products Tipaque TTO-55 (B) and Tipaque TTO-55 (A) from the company Ishihara and

UVT 14/4 from the company Kemira, with alumina and aluminium stearate, such as the product Microtitanium Dioxide MT 100 T, MT 100 TX, MT 100 Z and MT-Ol from the company Tayca, and the products Solaveil CT-IO W and Solaveil CT 100 from the company Uniqema, and the product Eusolex T-AVO from the company Merck,

- with silica, alumina and alginic acid, such as the product MT-100 AQ from the company Tayca, with alumina and aluminium laurate, such as the product Microtitanium Dioxide MT 100 S from the company Tayca, with iron oxide and iron stearate, such as the product Microtitanium Dioxide MT 100 F from the company Tayca, with zinc oxide and zinc stearate, such as the product BR351 from the company Tayca,

- with silica and alumina and treated with a silicone, such as the products Microtitanium Dioxide MT 600 SAS,

Microtitanium Dioxide MT 500 SAS or Microtitanium Dioxide MT 100 SAS from the company Tayca, with silica, alumina and aluminium stearate and treated with a silicone, such as the product STT-30-DS from the company Titan Kogyo,

- with silica and treated with a silicone, such as the product UV-Titan X 195 from the company Kemira,

- with alumina and treated with a silicone, such as the products Tipaque TTO-55 (S) from the company Ishihara or UV Titan M 262 from the company Kemira,

- with triethanolamine, such as the product STT-65-S from the company Titan Kogyo,

- with stearic acid, such as the product Tipaque TTO-55 (C) from the company Ishihara, - with sodium hexametaphosphate, such as the product

Microtitanium Dioxide MT 150 W from the company Tayca.

Other titanium oxide pigments treated with a silicone are preferably TiO₂ treated with octyltrimethylsilane and for which the mean size of the elementary particles is between 25 and 40 nm, such as the product sold under the trade name T 805 by the company Degussa Silices, TiO₂ treated with a polydimethylsiloxane and for which the mean size of the elementary particles is 21 nm, such as the product sold under the trade name 70250 Cardre UF TiO2SI3 by the company Cardre, anatase/rutile TiO₂ treated with a polydimethylhydrogenosiloxane and for which the mean size of the elementary particles is 25 nm, such as the product sold under the trade name Microtitanium Dioxide USP Grade Hydrophobic by the company Color Techniques .

The uncoated titanium oxide pigments are sold, for example, by the company Tayca under the trade names

Microtitanium Dioxide MT 500 B or Microtitanium Dioxide

MT 600 B, by the company Degussa under the name P 25, by the company Wacker under the name Transparent

Titanium Oxide PW, by the company Miyoshi Kasei under the name UFTR, by the company Tomen under the name ITS and by the company Tioxide under the name Tioveil AQ.

The uncoated zinc oxide pigments are, for example: those sold under the name Z-Cote by the company Sunsmart ; those sold under the name Nanox by the company Elementis ;

- those sold under the name Nanogard WCD 2025 by the company Nanophase Technologies .

The coated zinc oxide pigments are, for example:

- those sold under the name Zinc Oxide CS-5 by the company Toshibi (ZnO coated with polymethyl- hydrogenosiloxane) ; - those sold under the name Nanogard Zinc Oxide FN by the company Nanophase Technologies (as a 40% dispersion in Finsolv TN, Ci₂-Ci₅ alkyl benzoate) ;

- those sold under the name Daitopersion ZN-30 and Daitopersion ZN-50 by the company Daito (dispersions in cyclopolymethylsiloxane/oxyethylenated polydimethyl- siloxane, containing 30% or 50% of nanozinc oxides coated with silica and polymethylhydrogenosiloxane) ;

- those sold under the name NFD Ultrafine ZnO by the company Daikin (ZnO coated with perfluoroalkyl phosphate and copolymer based on perfluoroalkylethyl as a dispersion in cyclopentasiloxane) ;

- those sold under the name SPD-Zl by the company Shin- Etsu (ZnO coated with silicone-grafted acrylic polymer, dispersed in cyclodimethylsiloxane) ;

- those sold under the name Escalol ZlOO by the company ISP (alumina-treated ZnO dispersed in an ethylhexyl methoxycinnamate/PVP-hexadecene/methicone copolymer mixture) ; - those sold under the name Fuji ZnO-SMS-10 by the company Fuji Pigment (ZnO coated with silica and polymethylsilsesquioxane) ;

- those sold under the name Nanox Gel TN by the company Elementis (ZnO dispersed at a concentration of 55% in Ci₂-Ci₅ alkyl benzoate with hydroxystearic acid polycondensate) .

The uncoated cerium oxide pigments are sold under the name Colloidal Cerium Oxide by the company Rhone- Poulenc.

The uncoated iron oxide pigments are sold, for example, by the company Arnaud under the names Nanogard WCD 2002 (FE 45B) , Nanogard Iron FE 45 BL AQ, Nanogard FE 45R AQ and Nanogard WCD 2006 (FE 45R) or by the company Mitsubishi under the name TY-220.

The coated iron oxide pigments are sold, for example, by the company Arnaud under the names Nanogard WCD 2008 (FE 45B FN) , Nanogard WCD 2009 (FE 45B 556) , Nanogard FE 45 BL 345 and Nanogard FE 45 BL or by the company BASF under the name Transparent Iron Oxide.

Mention may also be made of mixtures of metal oxides, especially of titanium dioxide and of cerium dioxide, including the silica-coated equal-weight mixture of titanium dioxide and of cerium dioxide, sold by the company Ikeda under the name Sunveil A, and also the alumina, silica and silicone-coated mixture of titanium dioxide and of zinc dioxide, such as the product M 261 sold by the company Kemira, or the alumina, silica and glycerol -coated mixture of titanium dioxide and of zinc dioxide, such as the product M 211 sold by the company Kemira.

According to one particularly preferred form, hydrophilic metal oxide pigments are used, and more particularly hydrophilic titanium oxide or zinc oxide pigments, or mixtures thereof.

The term "hydrophilic" preferably means particles which, when introduced into an aqueous phase at 25⁰C, to a mass concentration equal to 1%, allow the production of a solution that is macroscopically homogeneous to the naked eye .

Among the hydrophilic metal oxide particles that may be used according to the invention, mention may be made of:

(i) titanium oxide particles treated with at least one coating agent, such as: silica and alumina, such as the products Microtitanium Dioxide MT 500 SA and Microtitanium Dioxide MT 100 SA from the company Tayca, and the products Tioveil Fin, Tioveil OP, Tioveil MOTG and Tioveil IPM from the company Tioxide, the product Mirasun TIW 60 from the company Rhodia, the product Sunveil PW-6030A-20 from the company CCIC, and the product Solaveil CT-10 W from the company Uniqema,- sodium hexametaphosphate, such as the product Microtitanium Dioxide MT 150 W from the company Tayca; - alumina and glycerol, such as the product UVT-M212 from the company Kemira; - alumina, silica and alginic acid, for instance

Microtitanium Dioxide MT 100 AQ from the company Tayca;

(ii) untreated titanium oxide pigments, for instance those sold by the company Tayca under the trade names

Microtitanium Dioxide MT 500 B or Microtitanium Dioxide MT 600 B, by the company Degussa under the name P 25, by the company Wacker under the name Transparent Titanium Oxide PW, by the company Miyoshi Kasei under the name UFTR, by the company Tomen under the name ITS, and by the company Tioxide under the name Tioveil AQ; (iii) untreated zinc oxide particles, for instance those sold under the name Z-Cote by the company Sunsmart ; those sold under the name Nanox by the company Elementis;

- those sold under the name Nanogard WCD 2025 by the company Nanophase Technologies;

(iv) mixtures of coated titanium dioxide and zinc dioxide, such as the mixture coated with alumina, silica and glycerol, such as the product M 211 sold by the company Kemira.

Treated or untreated titanium oxide particles, which are amorphous or in crystalline form (rutile and/or anatase) , are most particularly preferred.

The organic and/or mineral agents for absorbing UV radiation are preferably present in the compositions according to the invention in proportions ranging from 0.01% to 20% by weight relative to the total weight of the composition, and preferably ranging from 0.1% to 10% by weight relative to the total weight of the composition.

According to one particular form of the invention, the compositions according to the invention also comprise at least one wetting agent whose function is to facilitate the wetting of the skin by significantly reducing the surface tension of the continuous phase of the said composition.

The term "wetting agent" preferably means any compound which, when introduced into an aqueous solution at 0.05% (by weight), makes it possible to reduce the surface tension of water to a value of less than 35 mN/m and preferably less than 30 mN/m.

The wetting agents in accordance with the invention are preferably chosen from water-soluble silicones comprising at least one terminal or pendent monovalent polyoxyalkylene group, and which, when introduced at

0.05% by weight into an aqueous solution, are able to reduce the surface tension of water to a value of less than 35 mN/m and preferably less than 30 mN/m.

The wetting agents in accordance with the invention are more preferentially chosen from water-soluble silicones comprising at least one polyoxyalkylene group of general formula (a) below

R² ₃SiO (R² ₂SiO) _p (R²PESiO) _qSiR² ₃ (a) in which

- the radicals R², which may be identical or different, denote a monovalent hydrocarbon-based radical chosen from alkyl, aryl and aralkyl radicals containing not more than 10 carbon atoms,- some of the radicals R² may also additionally contain an ethylcyclohexylene monoxide group of formula

and are in low proportion in the polysiloxane chain;

- p ranges from 0 to 150, preferably from 0 to 100 and more preferentially from 0 to 30;

- q ranges from 1 to 12, preferably from 1 to 10 and more preferentially from 1 to 8 , - the polyether group PE has the formula (b) below

-C_xH_2x (OC₂H₄) _y (OC₃Hs)₂OR³ (b) in which: x ranges from 1 to 8 and preferably from 2 to 4 and is more preferentially equal to 3; y is greater than 0; z is greater than or equal to 0; the values of y and z are such that the total molecular weight of the polyoxyalkylene portion of the polyether group PE ranges from 200 to 10 000 and more preferentially from 350 to 4000;

R³ denotes hydrogen, a Ci-C₈ alkyl group or a C₂-C₈ acyl group .

It should be noted that when z is other than 0, the polyoxyethylene and polyoxypropylene units may be randomly distributed along the polyether chain PE or distributed in blocks, or alternatively distributed both in blocks and randomly.

Preferably, the radicals R² are chosen from Ci-C₆ lower alkyls, for instance methyl, ethyl, butyl, hexyl , phenyl and benzyl. More particularly, the radicals R² are chosen from Ci-C₄ lower alkyls and even more particularly denote methyl.

Preferably, the radicals R³ are chosen from Ci-C₄ lower alkyls and even more particularly denote methyl.

The number of oxyethylene units in the group PE should be sufficient to produce a cloud point in water of between 25 and 9O⁰C and more preferentially from 40 to 7O⁰C.

The water-soluble silicones of formula (a) may be obtained according to the process described in document US-A-4 847 398.

Among the water-soluble silicones of formula (a) that are preferably used are those of formula (a') below:

MeSiO (MeSiO) _p (MePESiO) _qSiMe₃ (a' ) in which Me denotes methyl; PE denotes: - (CH₂) ₃O(OC₂H₄) _y (OC₃H_s)₂OR³ (b' ) in which y and z have the same values indicated above and R³ denotes hydrogen or a Ci-C₄ alkyl group, and more particularly methyl . As another family of water-soluble silicones that may be used according to the invention, mention may be made of the branched silicones of formula (c) below:

(MeSiO) _q_₂[ (SiOMe₂) _p/qOPE]_q (c) in which p and q have the same values indicated above in formula (a) ; Me means methyl; PE denotes the group of formula (d) below:

- (OC₂H₄)_y (OC₃H_s)₂R³ (d) in which y and z have the same values indicated above in formula (b) and R³ denotes a Ci-C₄ alkyl group and more particularly methyl .

Such silicones are sold, for example, by the company OSI under the trade names Silwet L-720^®, Silwet L-7002^®, Silwet L-7600^®, Silwet L-7604^®, Silwet L-7605^®, Silwet L-7607^®, Silwet 1614, Silwet L-7657^®, Silwet L-7200^®, Silwet L-7230, Silsoft 305, Silsoft 820 and Silsoft 880, or by the company Goldschmidt under tthhee ttrraaddee nnaammee;s Tegowet 260, Tegowet 500, Tegowet 505 and Tegowet 510 ®

The table below collates the surface tension values at 25⁰C of aqueous solutions comprising 0.05% (by weight) of various wetting agents.

According to the invention, the wetting agent (s) is

(are) present in concentrations ranging from 0.01% to

10% by weight, preferably from 0.05% to 5% by weight and more particularly from 0.1% to 3% by weight relative to the total weight of the final composition.

The aqueous compositions of the invention may especially be in the form of an oil-in-water emulsion (direct emulsion) or a water-in-oil-in-water emulsion (multiple emulsion) .

The compositions of the invention may contain any additive usually used in cosmetics and will find applications in the fields of care, makeup and antisun products .

The aqueous compositions in accordance with the present invention may also comprise standard cosmetic adjuvants chosen especially from fatty substances, organic solvents, ionic or nonionic, hydrophilic or lipophilic thickeners, softeners, humectants, opacifiers, stabilizers, emollients, silicones, antifoams, fragrances, preserving agents, anionic, cationic, nonionic, zwitterionic or amphoteric surfactants, active agents, fillers, polymers, propellants, acidifying or basifying agents or any other ingredient usually used in cosmetics and/or dermatology.

Hydrophilic thickeners that may be mentioned include carboxyvinyl polymers such as the Carbopol products (carbomers) and the Pemulen products (acrylate/C10-C30- alkylacrylate copolymer) ; the methacrylic acid/methyl acrylate/ethoxylated alkyl dimethyl -meta-isopropenyl benzyl isocyanate terpolymer (INCI name: Polyacrylate- 3), for instance the product sold by Amerchol under the name Viscophobe DB 1000; polyacrylamides, for instance the crosslinked copolymers sold under the names Sepigel 305 (CTFA name: polyacrylamide/C13-14 isoparaffin/ Laureth 7) or Simulgel 600 (CTFA name: acryl- amide/sodium acryloyldimethyltaurate copolymer/isohexa- decane/polysorbate 80) by the company SEPPIC; 2-acrylamido-2-methylpropanesulfonic acid polymers and copolymers, which are optionally crosslinked and/or neutralized, for instance the poly (2-acrylamido-2- methylpropanesulfonic acid) sold by the company Clariant under the trade name Hostacerin AMPS (CTFA name: ammonium polyacryldimethyltauramide) ; cellulose derivatives such as hydroxyethylcellulose,- polysaccharides and especially gums such as xanthan gum; and mixtures thereof .

Lipophilic thickeners that may be mentioned include synthetic polymers such as poly (Ci₀-C₃₀ alkyl acrylates) sold under the name Doresco IPA 13-1 by the company Landec, or modified clays such as hectorite and its derivatives, for instance the products sold under the name Bentone .

The organic solvents may be chosen from the group consisting of hydrophilic organic solvents, lipophilic organic solvents and amphiphilic solvents, or mixtures thereof .

Examples of hydrophilic organic solvents that may be mentioned include linear or branched monohydric alcohols containing from 1 to 8 carbon atoms, for instance ethanol, propanol, butanol, isopropanol or isobutanol; polyethylene glycols containing from 6 to 80 ethylene oxides,- polyols such as propylene glycol, isoprene glycol, butylene glycol, glycerol or sorbitol; monoalkyl or dialkyl isosorbides in which the alkyl groups containing from 1 to 5 carbon atoms, for instance dimethyl isosorbide,- glycol ethers, for instance diethylene glycol monomethyl ether or monoethyl ether and propylene glycol ethers, for instance dipropylene glycol methyl ether.

Amphiphilic organic solvents that may be mentioned include polypropylene glycol (PPG) derivatives such as fatty acid esters of polypropylene glycol, and derivatives of PPG and of fatty alcohols, for instance PPG-23 oleyl ether, and PPG-36 oleate.

Examples of lipophilic organic solvents that may be mentioned include fatty esters such as diisopropyl adipate, dioctyl adipate or alkyl benzoates .

Preserving agents that may be mentioned include para- hydroxybenzoic acid esters, also known as Parabens^® (in particular methyl paraben, ethyl paraben and propyl paraben) , phenoxyethanol , formaldehyde generators, for instance imidazolidinylurea or diazolidinylurea, chlorhexidine digluconate, sodium benzoate, caprylyl glycol, iodopropynyl butyl carbamate, pentylene glycol, alkyltrimethylammonium bromides such as myristyl- trimethylammonium bromide (CTFA name: myrtrimonium bromide) , dodecyltrimethylammonium bromide, hexadecyl- trimethylammonium bromide, and mixtures thereof such as the mixture sold under the name Cetrimide^® by the company FEF Chemicals. The preserving agent may be present in the composition according to the invention in a content ranging from 0.001% to 10% by weight, especially ranging from 0.1% to 5% by weight and in particular ranging from 0.2% to 3% by weight relative to the total weight of the composition.

As fillers that may be used in the composition of the invention, examples that may be mentioned include pigments; silica powder; talc,- polyamide particles and especially those sold under the name Orgasol by the company Atochem; polyethylene powders,- powders of natural organic materials such as starch powders, especially of crosslinked or non-crosslinked corn starch, wheat starch or rice starch, such as the starch powders crosslinked with octenylsuccinate anhydride sold under the name Dry-Flo by the company National Starch; microspheres based on acrylic copolymers, such as those made of ethylene glycol dimethacrylate/lauryl methacrylate copolymer sold by the company Dow Corning under the name Polytrap,- polymethyl methacrylate powders such as those sold under the name Micropearl M 100 by the company Matsumoto; expanded powders such as hollow microspheres and especially the microspheres sold under the name Expancel by the company Kemanord Plast or under the name Micropearl F 80 ED by the company Matsumoto; silicone resin microbeads such as those sold under the name Tospearl by the company Toshiba Silicone,- polyurethane powders such as the hexamethylene diisocyanate/trimethylol hexyl lactone copolymer powder sold under the name Plastic Powder D- 400 by the company Toshiba Pigment (CTFA name: HDI/Trimethylol Hexyllactone Crosspolymer) ; and mixtures thereof. When they are present, these fillers may be in amounts ranging from 0.001% to 20% by weight, preferably from 0.1% to 10% by weight and better still from 1% to 5% by weight relative to the total weight of the composition.

Needless to say, a person skilled in the art will take care to select the optional additional compound (s) mentioned above and/or the amounts thereof such that the advantageous properties intrinsically associated with the compositions in accordance with the invention are not, or are not substantially, adversely affected by the envisaged addition (s) .

The compositions in accordance with the invention are generally oil-in-water simple emulsions or water-in- oil-in-water triple emulsions.

The emulsifying surfactants are chosen in an appropriate manner depending on the chosen type of emulsion. When the emulsion is a triple emulsion, it generally comprises an emulsifier in the primary emulsion and an emulsifier in the outer phase into which the primary emulsion is introduced.

In the case of the oil-in-water simple emulsion, the dispersed oily phase may preferably range from 5% to 60% by weight and better still from 10% to 50% by weight relative to the total weight of the simple emulsion. In the case of the water-in-oil-in-water triple emulsion, the W/0 primary emulsion may represent, for example, from 5% to 70% by weight, preferably from 10% to 60% by weight and better still from 15% to 50% by weight relative to the total weight of the triple emulsion. The inner aqueous phase of the W/0 primary emulsion preferably represents from 5% to 90%, better still from 30% to 90% and even better still from 40% to 80% of the total weight of the primary emulsion.

The emulsifying surfactants are generally present in a minimum concentration of 0.5% by weight relative to the total weight of the composition.

They are preferably used in proportions ranging from 0.5% to 30% by weight, preferably from 0.5% to 20% by weight and better still from 0.5% to 15% by weight relative to the total weight of the composition.

As emulsifiers that may be used for the preparation of the 0/W emulsions, examples that may be mentioned include nonionic emulsifiers such as fatty acid esters of oxyalkylenated (more particularly polyoxyethylen- ated) polyols, for example polyethylene glycol stearates, for instance PEG-100 stearate, PEG-50 stearate and PEG-40 stearate; fatty acid esters of oxyalkylenated sorbitan comprising, for example, from 20 to 100 EO, for example those sold under the trade names Tween 20 or Tween 60 by the company Uniqema,- oxyalkylenated (oxyethylenated and/or oxypro- pylenated) fatty alkyl ethers,- alkoxylated or non- alkoxylated sugar esters, for instance sucrose stearate such as PEG-20 methylglucose sesquistearate,- sorbitan esters such as the sorbitan palmitate sold under the name Span 40 by the company Uniqema; diacid esters of fatty alcohols, for instance dimyristyl tartrate; mixtures of these emulsifiers, for instance the mixture of glyceryl stearate and of PEG-100 stearate (CTFA name: Glyceryl Stearate/PEG-100 Stearate) sold under the name Arlacel 165 by the company Uniqema and under the name Simulsol 165 by the company SEPPIC; or the mixture of dimyristyl tartrate, cetearyl alcohol, Pareth-7 and PEG-25 laureth-25, sold under the name Cosmacol PSE by the company Sasol (CTFA name: Dimyristyl tartrate/cetearyl alcohol/12-15 Pareth-7/PPG 25 laureth 25) .

Coemulsifiers such as, for example, fatty alcohols containing from 8 to 26 carbon atoms, for instance cetyl alcohol, stearyl alcohol and the mixture thereof (cetearyl alcohol), octyldodecanol , 2-butyloctanol , 2- hexyldecanol, 2-undecylpentadecanol or oleyl alcohol, or fatty acids, may be added to these emulsifiers.

In the W/O/W triple emulsions according to the invention, the W/0 primary emulsion advantageously comprises at least one emulsifier with an HLB of less than 10 (HLB = Hydrophilic Lipophilic Balance) . The emulsifiers may be chosen, for example, from the group comprising alkoxylated and especially ethoxylated fatty alcohols, alkoxylated and especially ethoxylated fatty esters, glycerolated esters or ethers (for instance polyglyceryl-4 isostearate) , fatty acid salts such as aluminium stearate, sugar-based surfactants such as methylglucose isostearate, polyolefin-based polymeric surfactants and silicone emulsifiers, and mixtures thereof .

For the polyolefin-based polymeric surfactants, the apolar part is chosen from polyolefins such as ethylene, propylene, 1-butene, isobutene, 1-pentene, 2- methyl-1-butene, 3 -methyl -1-butene, 1-hexene, 1- heptene, 1-octene, 1-decene, 1-undecene, 1-dodecene, 1- tridecene, 1-tetradecene, 1-pentadecene, 1-hexadecene, 1-heptadecene and 1-octadecene polymers and/or copolymers . The polymer chains may or may not be hydrogenated. They consist of at least 40 carbons and preferably from 60 to 700 carbons. The polar part of these polymeric surfactants may be anionic, cationic, nonionic, zwitterionic or amphoteric. It consists, for example, of acrylic, polyalkylene glycol or polyalkyleneimine derivatives. The polymeric surfactants containing a carboxylic acid polar part are derived, for example, from the reaction of a polyolefin with carboxylic acids such as maleic acid, maleic anhydride, fumaric acid, itaconic acid, citraconic acid, mesaconic acid and aconitic acid. Preferably, the polar part consists of succinic acid or anhydride, ester or amide derivatives thereof, the corresponding salts of alkali metal, alkaline-earth metal organic ions, or alternatively of polyoxyethylene.

The polyolefin-based polymeric surfactants are also chosen from the polyolefin derivatives of succinic acid described in patents US 4 234 435, US 4 708 753, US 5 129 972, US 4 931 110, GB 2 156 799 and US 4 919 179. The polyolefin part may consist of hydrogenated or non- hydrogenated polyisobutylene . The succinic acid or anhydride may be modified with alcohols, amines, alkanolamines or polyols, or alternatively may be in the form of alkali metal or alkaline-earth metal ions or organic ions, for instance diethanolammonium or triethanolammonium ions. Mention may be made especially of polyisobutylenes containing modified succinic end groups, such as the products sold under the names L2724, L2721, L2722, OS156565 and Lubrizol 5603 by the company Lubrizol, or Chemcinnate 2000 sold by the company Chemron. Another example of a polymeric surfactant that may be used in the invention is the product of the reaction of maleic anhydride with polyisobutylene, such as Glissopal SA sold by BASF.

The silicone emulsifiers may be chosen, for example, from the group comprising dimethicone copolyols, alkyldimethicone copolyols possibly comprising heteroatoms such as fluorine, and mixtures containing them, for example the mixture of polyglyceryl-4 isostearate/cetyl dimethicone copolyol/hexyl laurate sold under the name Abil WE 09 by the company Goldschmidt, cetyl dimethicone copolyol sold under the name Abil EM 90 by the company Goldschmidt and the mixture of cyclomethicone/dimethicone copolyol sold under the name Q2-3225C by the company Dow Corning. The emulsifier content in the primary emulsion generally ranges from 0.1% to 10% by weight and preferably from 0.5% to 5% by weight of active material relative to the total weight of the primary emulsion.

The compositions in accordance with the invention generally comprise at least one oily phase that contains at least one oil, especially a cosmetic oil. The term "oil" means a fatty substance that is liquid at room temperature (25⁰C) .

As oils that may be used in the composition of the invention, it is possible to use, for example, hydrocarbon-based oils of animal origin, such as perhydrosqualene (or squalane) ; hydrocarbon-based oils of plant origin, such as caprylic/capric acid triglycerides, for instance those sold by the company Stearineries Dubois or those sold under the names Miglyol 810, 812 and 818 by the company Dynamit Nobel, or alternatively oils of plant origin, for instance sunflower oil, corn oil, soybean oil, marrow oil, grapeseed oil, sesameseed oil, hazelnut oil, apricot oil, macadamia oil, arara oil, coriander oil, castor oil, avocado oil, jojoba oil and shea butter oil; synthetic oils,- silicone oils, for instance volatile or non-volatile polymethylsiloxanes (PDMS) containing a linear or cyclic silicone chain, which are liquid or pasty at room temperature; fluoro oils, such as partially hydrocarbon-based and/or silicone-based fluoro oils, for instance those described in document JP-A-2 295 912; ethers, such as dicaprylyl ether (CTFA name: Dicaprylyl ether); esters, for instance Ci₂-Ci₅ fatty alkyl benzoates (Finsolv TN from Finetex) ; arylalkyl benzoates, for instance 2-phenylethyl benzoate (X-Tend 226 from ISP); and amidated oils, for instance isopropyl N-lauroylsarcosinate (Eldew SL-205 from Ajimoto); mixtures thereof.

The oily phase may also comprise one or more fatty substances chosen, for example, from fatty alcohols (cetyl alcohol, stearyl alcohol or cetearyl alcohol), fatty acids (stearic acid) or waxes (paraffin, polyethylene wax, carnauba wax or beeswax) . The oily phase may contain lipophilic gelling agents, surfactants or organic or mineral particles. The oily phase may preferably represent from 2% to 70% by weight of oil relative to the total weight of the composition.

When it is an emulsion, the aqueous phase of the said emulsion may comprise a nonionic vesicular dispersion prepared according to known processes (Bangham, Standish and Watkins, J. MoI. Biol. 13, 238 (1965), FR 2 315 991 and FR 2 416 008) .

According to one particular embodiment of the invention, the oil-in-water emulsions may comprise only 1% by weight or less of emulsifying surfactants, and may even be free of emulsifying surfactants, while at the same time being stable on storage. In this case, they may be stabilized via various techniques such as the use of the hydrophilic or lipophilic thickeners such as those of patent EP 864 320, amphiphilic polymers such as those mentioned in patent EP 1 093 796 or in patent application WO 02/44231, and solid particles (Pickering-type emulsions) such as the emulsions mentioned in patent applications WO 98/42300, WO 98/42301, EP 98/7001, EP 98/7002, EP 98/7003, EP 98/7004, EP 98/7005, EP 98/7006, EP 98/7007, EP 98/7008, WO 2000/07548, WO 2000/07549 and EP 99/2233. Among the emulsion stabilizers that will be used more particularly are isophthalic acid or sulfoisophthalic acid polymers, and in particular phthalate/sulfoiso- phthalate/glycol copolymers (for example diethylene glycol/phthalate/isophthalate/1, 4-cyclohexanedimethanol) sold under the name Eastman AQ Polymer (AQ35S, AQ38S, AQ55S and AQ48 Ultra) by the company Eastman Chemical.

Another subject of the present invention consists of the use of the compositions according to the invention as defined above for the manufacture of cosmetic products for treating the skin, the lips, the nails, the hair, the eyelashes, the eyebrows and/or the scalp, especially care products, antisun products and makeup products .

The composition according to the invention may constitute a skincare product, especially for the face, the neck, the contour of the eyes or the body,- or a makeup product such as a complexion product (especially a foundation), a concealer product, an antisun product or a skin-cleansing product. The composition according to the invention will preferentially be an antisun product .

The cosmetic compositions according to the invention may be used, for example, as care and/or antisun products for the face and/or the body. They may optionally be conditioned in aerosol form and may be in the form of mousse or spray.

The compositions according to the invention in the form of vaporizable fluid lotions in accordance with the invention are applied to the skin or the hair in the form of fine particles by means of pressurization devices. The devices in accordance with the invention are well known to those skilled in the art and comprise non-aerosol pumps or "atomizers", aerosol containers comprising a propellant and also aerosol pumps using compressed air as propellant. The latter devices are described in patents US 4 077 441 and US 4 850 517 (which form an integral part of the content of the description) .

The compositions conditioned in aerosol form in accordance with the invention generally contain conventional propellants, for instance hydrofluoro compounds, dichlorodifluoromethane, difluoroethane, dimethyl ether, isobutane, n-butane, propane or trichlorofluoromethane . They are preferably present in amounts ranging from 15% to 50% by weight relative to the total weight of the composition.

The invention will now be described with reference to the examples that follow, which are given as non- limiting illustrations. In these examples, unless otherwise indicated, the amounts are expressed as weight percentages. The following antisun formulations were prepared; the amounts are indicated as weight percentages:

A simple test consists in drawing a 30 μm film of the fluid composition, at 35⁰C, over a quartz plate, leaving it to dry and observing it by microscopy, under UV. The compositions of the invention, containing at least one water-soluble heat-induced gelling polymer, are characterized by a perfectly homogeneous film. This homogeneity is reflected by the uniformity of UV absorption materialized by a dark image, without defects (holes (white) in the film or concentrated areas (black) of UV-screening agents) . Examples

Examples 1 and 2

Examples 3 and 4: water-soluble heat-induced gelling polymer based on poly (N-isopropylacrylamide)

The composition below comprises a water-soluble heat- induced gelling polymer with a block structure composed of a block based on randomly distributed N- isopropylacrylamide and n-butyl acrylate and of a 0 polyethylene glycol block. This polymer has at 5% in water a gel point equal to 15⁰C, and gives a transparent gel above this temperature.

This water-soluble heat-induced gelling polymer was 5 formulated in a fluid screening oil-in-water emulsion.

Introducing this water-soluble heat-induced gelling polymer into a fluid screening emulsion allows its photoprotective properties to be amplified.

Examples 5 and 6: water-soluble heat- induced gelling polymer based on a copolymer of AMPS and of a methacrylic acid ester macromonomer and a statistical EO/PO copolymer

The heat-induced gelling polymer used in this example is a copolymer of polyacrylamido-2-methylpropane- sulfonic acid (AMPS) neutralized with aqueous ammonia (40% by weight) and of a polyether methacrylate macromonomer (60%) in which the polyether is a PEO/PPO statistical copolymer comprising 5.5 mol of ethylene oxide (EO) units and 31 mol of propylene oxide units. The polyether methacrylate macromonomer is obtained according to the Standard techniques by esterification of methacrylic acid and of the polyether as defined above manufactured by the company Laporte under the trade name A286.

This copolymer is obtained by precipitation polymerization in tert-butanol of AMPS and of the "polyether methacrylate" macromonomer described above according to the synthetic process described in patent application EP 1 069 142.

This polymer has at 5% in water a gel point equal to 15⁰C, and gives a transparent gel above this temperature. This water-soluble heat-induced gelling polymer was formulated in a fluid screening oil-in- water emulsion.

- 4 !

Introducing this heat-induced gelling polymer into a fluid screening emulsion allows its photoprotective properties to be amplified. It is clearly seen that the use of a heat-induced gelling polymer in a sunscreen- based fluid composition very significantly improves the efficacy of these sunscreens.

Claims

1. Fluid screening cosmetic composition comprising, in a physiologically acceptable medium: a) at least one water-soluble heat-induced gelling polymer; b) at least one continuous aqueous phase,- c) at least one oily phase in a concentration ranging from 1% to 70% by weight relative to the total weight of the composition, and d) at least one organic UV- screening agent.

2. Composition according to Claim 1, in which the heat-induced gelling polymer is water-soluble and comprises water-soluble units and units having in water a lower critical solution temperature, LCST, the heat- induced demixing temperature in aqueous solution of the said units with an LCST being from 5 to 4O⁰C for a mass concentration in water of 1% of the said units and the concentration of the said polymer in the said composition being such that its gel point is in the range from 5 to 4O⁰C.

3. Composition according to Claim 2, in which the units with an LCST of the polymer have a heat -induced demixing temperature of from 5 to 4O⁰C for a mass concentration in water of 1% by weight of the said units with an LCST.

4. Composition according to Claim 3, in which the heat -induced demixing temperature in aqueous solution of the units with an LCST of the polymer is from 10 to 35⁰C for a mass concentration in water of 1% of the said units with an LCST.

5. Composition according to any one of Claims 2 to 4 , in which the polymer concentration is such that the gel point is in the range from 10 to 35⁰C.

6. Composition according to any one of Claims 2 to 5 , in which the polymer is in the form of a block polymer comprising blocks consisting of water-soluble units alternating with blocks consisting of units with an LCST, or in the form of a grafted polymer whose backbone is formed from water-soluble units, the said backbone bearing grafts consisting of units with an LCST, the said polymers possibly being partially crosslinked.

7. Composition according to any one of Claims 2 to 6 , in which the water-soluble units may be totally or partially obtained by polymerization, especially free- radical polymerization, or by polycondensation, or alternatively consist totally or partially of existing natural or modified natural polymers.

8. Composition according to Claim 7, in which the water-soluble units may be totally or partially obtained by polymerization, especially free-radical polymerization, of at least one monomer chosen from the following monomers:

- (meth) acrylic acid;

- vinyl monomers of formula (I) below:

H₂C-CR _(|j CO

in which:

- R is chosen from H, -CH₃, -C₂H₅ and -C₃H₇, and

- X is chosen from:

- alkyl oxides of -OR' type in which R' is a linear or branched, saturated or unsaturated hydrocarbon-based radical containing from 1 to 6 carbon atoms, optionally substituted with at least one halogen atom (iodine, bromine, chlorine or fluorine); a sulfonic (-SO₃ ^"), sulfate (-SO₄ ^"), phosphate (-PO₄H₂); hydroxyl (-0H); primary amine (-NH₂); secondary amine (-NHRi), tertiary amine (-NRiR₂) or quaternary amine (-N⁺RiR₂R₃) group with Ri, R₂ and R₃ being, independently of each other, a linear or branched, saturated or unsaturated hydrocarbon-based radical containing 1 to 6 carbon atoms, with the proviso that the sum of the carbon atoms of R' + Ri + R₂ + R₃ does not exceed 7; and - -NH₂, -NHR₄ and -NR₄R₅ groups in which R₄ and R₅ are, independently of each other, linear or branched, saturated or unsaturated hydrocarbon-based radicals containing 1 to 6 carbon atoms, with the proviso that the total number of carbon atoms of R₄ + R₅ does not exceed 7, the said R₄ and R₅ optionally being substituted with a halogen atom (iodine, bromine, chlorine or fluorine); a hydroxyl (-0H); sulfonic (-SO₃ ^"); sulfate (-SO₄ ^"); phosphate (-PO₄H₂); primary amine (-NH₂) ; secondary amine (-NHRi) , tertiary amine (-NRiR₂) and/or quaternary amine (-N⁺RiR₂R₃) group with Ri, R₂ and R₃ being, independently of each other, a linear or branched, saturated or unsaturated hydrocarbon-based radical containing 1 to 6 carbon atoms, with the proviso that the sum of the carbon atoms of R₄ + R₅ + Ri + R₂ + R₃ does not exceed 7;

- maleic anhydride;

- itaconic acid;

- vinyl alcohol of formula CH₂=CHOH;

- vinyl acetate of formula CH₂=CH-OCOCH₃; - N-vinyllactams such as N-vinylpyrrolidone, N-vinyl- caprolactam and N-butyrolactam;

- vinyl ethers of formula CH₂=CHOR₆ in which R₆ is a linear or branched, saturated or unsaturated hydrocarbon-based radical containing from 1 to 6 carbons;

- water-soluble styrene derivatives, especially styrene sulfonate;

- dimethyldiallylammonium chloride; and

- vinylacetamide .

9. Composition according to Claim 7, in which the water-soluble units of the polymer consist totally or partially of polycondensates or of natural or modified natural polymers chosen from one or more of the following components:

- water-soluble polyurethanes,-

- xanthan gum;

- alginates and derivatives thereof such as propylene glycol alginate; cellulose derivatives and especially carboxy- methylcellulose, hydroxypropylcellulose, hydroxyethyl- cellulose and quaternized hydroxyethylcellulose,- galactomannans and derivatives thereof, such as konjac gum, guar gum, hydroxypropyl guar, hydroxypropyl guar modified with sodium methylcarboxylate groups, and guar hydroxypropyltrimethylammonium chloride; and

- polyethyleneimine .

10. Composition according to either of Claims 8 and 9, in which the water-soluble units of the polymer have a molar mass ranging from 1000 g/mol to 5 000 000 g/mol when they constitute the water-soluble backbone of a grafted polymer, or a molar mass ranging from 500 g/mol to 100 000 g/mol when they constitute a block of a multiblock polymer.

11. Composition according to any one of Claims 2 to

10, in which the units with an LCST of the water- soluble heat-induced gelling polymer consist of one or more polymers chosen from the following polymers: polyethers such as polypropylene oxide (PPO) , and statistical copolymers of ethylene oxide (EO) and of propylene oxide (PO) , - polyvinyl methyl ethers,

- N- substituted polymeric and copolymeric derivatives of acrylamide with an LCST, and

- polyvinylcaprolactam and vinylcaprolactam copolymers .

12. Composition according to Claim 11, in which the units with an LCST consist of polypropylene oxide

(PPO)_n in which n is an integer from 10 to 70, or of statistical copolymers of ethylene oxide (EO) and of propylene oxide (PO) represented by the formula: ( EO) _1n ( PO) _n in which m is an integer ranging from 1 to 40 and preferably from 2 to 20, and n is an integer ranging from 10 to 60 and preferably from 20 to 50.

13. Composition according to Claim 12, in which the units with an LCST consisting of polypropylene oxide

(PPO)_n or of statistical copolymers of ethylene oxide (EO) and of propylene oxide (PO) have a molar mass ranging from 500 to 5300 g/mol and more preferentially from 1500 to 4000 g/mol.

14. Composition according to any one of Claims 2 to 11 in which the units with an LCST of the water-soluble heat-induced gelling polymer consist of a polymer chosen from poly-N-isopropylacrylamide, poly-N- ethylacrylamide and copolymers of N-isopropylacrylamide or of N-ethylacrylamide and of a vinyl monomer chosen from the monomers having the formula (I) given in Claim 8, maleic anhydride, itaconic acid, vinylpyrrolidone, styrene and derivatives thereof, dimethyldiallyl- ammonium chloride, vinylacetamide, vinyl alcohol, vinyl acetate, vinyl ethers and vinyl acetate derivatives.

15. Composition according to Claim 14, in which the molar mass of the units with an LCST of the polymer is from 1000 g/mol to 500 000 g/mol and preferably from 2000 to 50 000 g/mol.

16. Composition according to any one of Claims 2 to

15, in which the mass proportion of the units with an LCST in the final polymer is preferably from 5% to 70%, especially from 10% to 60% and particularly from 20% to 50% by weight relative to the final polymer.

17. Composition according to any one of Claims 1 to

16, in which the heat-induced gelling polymer is chosen from:

(1) polyurethanes comprising polyethylene oxide/poly- oxypropylene/polyethylene oxide (or PEO-PPO-PEO) groups ;

(2) multiblock copolymers comprising a poly-N- isopropylacrylamide block and n-butyl acrylate randomly distributed and a polyethylene glycol block;

(3) copolymers of acrylamidomethylpropanesulfonic acid (or AMPS) or the salts thereof and of macromonomers of an ester of (meth) acrylic acid and of ethoxylated and/or propoxylated alkyl ;

(4) copolymers consisting of a polyacrylic acid (PAA) backbone bearing side chains or grafts consisting of units with an LCST chosen from:

(i) those of the type such as statistical copolymers of ethylene oxide (EO) and of propylene oxide (PO) , represented by the formula:

(EO)_1n(PO)_n in which m is an integer ranging from 1 to 40 and preferably from 2 to 20, and n is an integer ranging from 10 to 60 and preferably from 20 to 50; the molar mass of these units with an LCST preferably being from 500 to 5300 g/mol and more preferentially from 1500 to 4000 g/mol;

(ii) poly-N- isopropylacrylamide polymers whose molar mass is preferably from 1000 g/mol to 500 000 g/mol and more preferentially from 2000 to 50 000 g/mol.

18. Composition according to any one of Claims 1 to

17, in which the content of water-soluble heat-induced gelling polymer ranges from 0.01% to 20% and better still from 1% to 10% relative to the total weight of the composition.

19. Composition according to any one of Claims 1 to

18, in which the organic UV-screening agent (s) is (are) chosen from cinnamic derivatives; anthranilates ; salicylic derivatives, dibenzoylmethane derivatives, camphor derivatives; benzophenone derivatives; diphenylacrylate derivatives; triazine derivatives; benzotriazole derivatives; benzalmalonate derivatives; benzimidazole derivatives; imidazolines; bis-benzazolyl derivatives; p-aminobenzoic acid (PABA) derivatives; methylenebis (hydroxyphenylbenzotriazole) derivatives; benzoxazole derivatives; screening polymers and screening silicones; alkylstyrene-based dimers; 4,4- diarylbutadiene derivatives; and mixtures thereof.

20. Composition according to Claim 19, in which the organic UV-screening agent (s) is (are) chosen from: Ethylhexyl Methoxycinnamate,

Ethylhexyl salicylate, Homosalate, Octocrylene,

Phenylbenzimidazolesulfonic acid, Benzophenone-3 , Benzophenone-4 , Benzophenone- 5 , n-Hexyl 2- (4-diethylamino-2-hydroxybenzoyl) benzoate, 4-Methylbenzylidenecamphor, Terephthalylidenedicamphorsulfonic acid, Disodium phenyldibenzimidazoletetrasulfonate, Methylenebis (benzotriazolyl) tetramethylbutylphenol , bis-Ethylhexyloxyphenol Methoxyphenyl Triazine, Ethylhexyl Triazone, Diethylhexyl Butamido Triazone, 2,4,6-tris (biphenyl-4-yl) -1,3,5-triazine, 2,4, 6-tris (terphenyl) -1,3, 5 -triazine,

Drometrizole trisiloxane, Polysilicone- 15 ,

1 , 1-Dicarboxy (2,2' -dimethylpropyl) -4 , 4-diphenyl- butadiene, 2 , 4-Bis [5-1 (dimethylpropyl) benzoxazol-2 -yl (4- phenyl) imino] -6- (2 -ethylhexyl) imino-1, 3, 5-triazine, and mixtures thereof .

21. Composition according to any one of Claims 1 to 20, also comprising mineral screening agents chosen from coated or uncoated metal oxide pigments whose mean primary particle size ranges between 5 nm and 100 nm and preferably between 10 nm and 50 nm.

22. Composition according to Claim 21, in which the mineral screening agents are chosen from coated or uncoated titanium oxide, iron oxide, zinc oxide, zirconium oxide or cerium oxide pigments.

23. Composition according to either of Claims 21 and 22, in which the mineral screening agents are chosen from coated or uncoated hydrophilic metal oxide pigments .

24. Composition according to Claim 23, in which the hydrophilic mineral screening agents are chosen from hydrophilic titanium oxide or zinc oxide pigments, or mixtures thereof .

25. Composition according to any one of Claims 21 to

24, in which the mineral screening agents are chosen from treated or untreated titanium oxide particles, in amorphous form or in crystalline form (rutile and/or anatase) .

26. Composition according to any one of Claims 1 to

25, in which the organic and/or mineral agent (s) for absorbing UV radiation is (are) present in proportions ranging from 0.01% to 20% by weight relative to the total weight of the composition, and preferably ranging from 0.1% to 10% by weight relative to the total weight of the composition.

27. Composition according to any one of Claims 1 to

26, also comprising at least one wetting agent.

28. Composition according to Claim 27, in which the wetting agent is chosen from water-soluble silicones comprising at least one terminal or pendent monovalent polyoxyalkylene group.

29. Composition according to Claim 28, in which the wetting agent is chosen from water-soluble silicones comprising at least one polyoxyalkylene group of general formula (a) below:

R² ₃SiO (R² ₂SiO) p (R²PESiO) _qSiR² ₃ (a) in which - the radicals R², which may be identical or different, denote a monovalent hydrocarbon-based radical chosen from alkyl, aryl and aralkyl radicals containing not more than 10 carbon atoms,- some of the radicals R² may also additionally contain an ethylcyclohexylene monoxide group of formula

and are in low proportion in the polysiloxane chain;

- p ranges from 0 to 150, preferably from 0 to 100 and more preferentially from 0 to 30; - q ranges from 1 to 12, preferably from 1 to 10 and more preferentially from 1 to 8 ,

- the polyether group PE has the formula (b) below

-C_xH_2x (OC₂H₄) _y (OC₃Hs)₂OR³ (b) in which: x ranges from 1 to 8 and preferably from 2 to 4 and is more preferentially equal to 3; y is greater than 0; z is greater than or equal to 0; the values of y and z are such that the total molecular weight of the polyoxyalkylene portion of the polyether group PE ranges from 200 to 10 000 and more preferentially from

350 to 4000;

R³ denotes hydrogen , a Ci - C₈ alkyl group or a C₂ - C₈ acyl group .

30. Composition according to Claim 29, in which the radicals R² are chosen from Ci-C₆ lower alkyls; phenyl and benzyl .

31. Composition according to Claim 30, in which the radicals R² are chosen from Ci-C₄ lower alkyls and even more particularly denote methyl .

32. Composition according to any one of Claims 29 to

31, in which the radicals R³ are chosen from Ci-C₄ lower alkyls and even more particularly denote methyl.

33. Composition according to any one of Claims 28 to

32, in which the water-soluble silicones of formula (a) are chosen from those of formula (a') below:

MeSiO (MeSiO) _p (MePESiO) _qSiMe₃ (a' ) in which Me denotes methyl; PE denotes the group of formula (b' ) :

-(CH₂)₃0 (OC₂H₄)_y (OC₃Hs)₂OR³ (b' ) in which y and z have the same values indicated in Claim 29 and R³ denotes hydrogen or a Ci-C₄ alkyl group, and more particularly methyl.

34. Composition according to Claim 28, in which the water-soluble silicone is chosen from the branched silicones of formula (c) below: (MeSiO) _q-2 [ (SiOMe₂) _p/qOPE] _q (c) in which

- q ranges from 1 to 12, preferably from 1 to 10 and more preferentially from 1 to 8 ,

- Me means methyl ;

- PE denotes the group of formula (d) below:

- (OC₂H₄)_y (OC₃H_s)₂R³ (d) in which - y is greater than 0;

- z is greater than or equal to 0; the values of y and z are such that the total molecular weight of the polyoxyalkylene portion of the polyether group PE ranges from 200 to 10 000 and more preferentially from 350 to 4000 ;

- R³ denotes a Ci-C₄ alkyl group.

35. Composition according to any one of Claims 27 to 34, in which the wetting agent (s) is (are) present in concentrations ranging from 0.01% to 10% by weight, preferably from 0.05% to 5% by weight and more particularly from 0.1% to 3% by weight relative to the total weight of the final composition.

36. Composition according to any one of Claims 1 to

35, also comprising at least one cosmetic adjuvant chosen from fatty substances, organic solvents, ionic or nonionic, hydrophilic or lipophilic thickeners, softeners, humectants, opacifiers, stabilizers, emollients, silicones, antifoams, fragrances, preserving agents, anionic, cationic, nonionic, zwitterionic or amphoteric surfactants, active agents, fillers, polymers, propellants and acidifying or basifying agents.

37. Composition according to any one of Claims 1 to

36, characterized in that it is in the form of an oil- in-water or water-in-oil-in-water emulsion.

38. Use of at least one water-soluble heat-induced gelling polymer as defined according to any one of the preceding claims, in a composition as defined according to any one of the preceding claims, for the purpose of improving the photoprotective efficacy.

39. Use of at least one water-soluble heat-induced gelling polymer as defined according to any one of the preceding claims, in a composition as defined according to any one of the preceding claims, for the purpose of improving the homogeneity of spreading on keratin materials .