EP2908795A1

EP2908795A1 - Sun protection composition comprising a (meth)acrylic copolymer and pigmentary particles

Info

Publication number: EP2908795A1
Application number: EP13786296.7A
Authority: EP
Inventors: Renaud Souzy; Jean-Marc Suau; Olivier Guerret
Original assignee: Coatex SAS
Current assignee: Coatex SAS
Priority date: 2012-10-18
Filing date: 2013-10-11
Publication date: 2015-08-26
Also published as: CN104736129B; US20150283057A1; US9700505B2; CN104736129A; WO2014060688A1; BR112015007288A2; MX2015004427A

Abstract

The present invention relates to the use, in a sun protection formulation comprising pigmentary particles as inorganic UV-screening agents, of novel additives as agents for improving the UV-absorbing capacities of said formulations, and also to the sun protection formulations comprising such agents.

Description

SOLAR PRODUCTION COMPOSITION COMPRISING A (METH) ACRYLIC COPOLYMER AND

The present invention relates to the technical field of cosmetics, in particular that of cosmetic sunscreen compositions. More particularly, the present invention relates to the use, in cosmetic compositions comprising pigment particles, as ultraviolet filtering agents, of novel additives as agents improving the UV-absorbing capacities of said compositions. The present invention also relates to sunscreen compositions comprising such agents.

It is known that UV-B rays, with wavelengths between 280 nm and 320 nm, cause erythema and skin burns. It is also known that UV-A rays, of wavelengths between 320 nm and 400 nm, which are responsible for the browning of the skin, are also likely to induce a skin. alteration of the latter, especially in the case of sensitive skin or skin continuously exposed to solar radiation. It is therefore desirable that the cosmetic sunscreen compositions are capable of filtering UV-A and UV-B radiation.

Numerous cosmetic compositions intended for the UV-A and / or UV-B photoprotection of the skin have been proposed to date. Such compositions typically comprise a UV radiation filtering agent. There are mainly two categories of filtering agents UV radiation: organic filters and pigment type filters, such as metal oxides, for example titanium dioxide and zinc oxide.

In this technical context, a number of documents of the prior art describe the use of additives in order to promote the cosmetic properties of sunscreen compositions containing them. There may be mentioned, for example, the use of crosslinked emulsifying emulsions of acrylic acid / C 1 -C 30 alkyl acrylate type, such as those known under the name Pemulen® or Carbopol®, the use of which is now widespread.

Nevertheless, it turns out that with certain copolymers of the prior art, the improvement of the cosmetic properties of the compositions is to the detriment of UV-performance. absorbent of these compositions. Thus, another part of the prior art describes the use of additives whose object is, besides obtaining advantageous cosmetic properties, obtaining sun protection compositions having protection indices higher than those which can be obtained. with the same filtering system, mention may be made in this regard of EP 0 685 227 (L'Oréal) which describes the use of particular polymers to improve the photoprotective properties of these compositions. The polymers referred to herein are of the methacrylic acid / ethyl acrylate / steareth-1G allyl ether crosslinked terpolymer type and the acrylic acid / vinyl acetate copolymer.

EP 1 142 564 (L'Oréal), which describes the combination in an oil-in-water emulsion cosmetic composition of a particular polyethylen mixture with an organic photoprotective system, is also mentioned. Other documents of the prior art describe the use of composite particles whose object is both to obtain a better protection against radiation and to obtain a composition having particular textural properties. Among these, one can quote the patent application EP 1 388 550 (Kao Corp) relating to the use of particles consisting of a metal oxide particle coated with a silicone or fluorinated compound. Reference may also be made to FR 2 970 172 (L'Oréal) in which the composite particles comprise a matrix and an inorganic UV filter. Such particles are formulated in the presence of a hydrophilic dispersing surfactant. Nevertheless, it should be noted that inorganic pigment type filters, for example titanium dioxide (TiO ₂ ), zinc oxide (ZnO), cerium oxide (CeOa) and / or iron oxides (Fe ₃ O ₄ , Fe ₂ O ₃ ) or composite mineral pigments, for example particles of titanium dioxide coated or having undergone one or more surface treatments of a chemical, electronic, mechanochemical and / or mechanical nature, are products whose availability becomes more and more limited because they rely on a natural resource. This leads to an increase in their price, which is a problem for formulators of sunscreen compositions.

The inventors have therefore sought a solution to this problem of the availability of pigment particles, mineral pigments type and coated mineral pigment type. More specifically, the inventors have sought a solution to reduced amounts of pigment particles are used in cosmetic sunscreen compositions without reducing the expected properties of said compositions. A number of documents of the prior art describe the use of dispersing agents which have the capacity to improve the state of dispersion of the pigments in cosmetic products. Nevertheless, despite the use of dispersing agents in cosmetic formulations intended for sun protection, the phenomenon of particle flocculation, in particular during the storage of the cosmetic composition and during the formation of the film on the skin, reduces the filtering efficiency of the agents. such as T1O2 and / or ZnO.

A solution to the technical problem of the availability of pigment particles, such as TiO 2 and / or ZnO, coated or not, is provided surprisingly by the use of a particular copolymer, of molecular weight and of specific structure . The inventors demonstrate, in fact, _" advantageously that it is possible to significantly reduce the quantity of pigment particles in the cosmetic sunscreen composition without reducing the UV-absorbing performance of said composition. There is a technical prejudice in the field of sunscreen compositions according to which, logically, a composition in which the amount of UV-filtering agents would be reduced would no longer provide adequate solar radiation protection. This technical prejudice is in particular incorporated in the introduction of the patent application FR 2 970 172. The inventors furthermore demonstrate that the copolymers according to the invention have no intrinsic UV-absorbing property. The present invention is therefore based on a particular combination of a UV radiation filtering agent, more particularly the pigment particles according to the invention, and a copolymer. The inventors demonstrate, in fact, the increase in UV absorbance of a cosmetic composition which combines the copolymers according to the invention, of specific structure and molecular weight, and pigment particles as filtering agents, in comparison with a cosmetic composition which does not comprise the copolymers according to the invention, this also when the content of pigment particles of said composition has been reduced (for example by 20 or 40% by weight relative to the reference). An object of the present invention is to improve the state of dispersion of the pigment particles in the cosmetic composition, by means of a particular copolymer, in order to increase the UV absorbing performances of the sunscreen compositions,

Another object of the present invention is to promote the filtering properties of pigment particles, such as in particular ΤiO ₂ and / or ZnO, coated or not, while minimizing the necessary quantities of these pigments in sunscreen compositions. container.

Another object of the present invention is to reduce the amount of pigment particles, such as TiO ₂ and / or ZnO, coated or not, without necessarily having to compensate for this decrease by adding another pigment in the composition.

Another object of the present invention is to enable a reduction in the amount of pigment particles, such as Ti0 ₂ and / or ZnO _s coated (s) or not, in the cosmetic compositions of sunscreen without substantial modification of the cosmetic properties of those for example without changing the organoleptic, sensory or textural characteristics.

Another object of the present invention is to provide a copolymer which makes it possible to increase, compensate or improve the UV-absorbing performance of sunscreens prepared by reducing the dose of pigment particles, such as TiO ₂ and / or ZnO, coated ( s) or not, without changing the organoleptic properties with good stability over time.

The present invention therefore relates to the use, in a sunscreen composition comprising pigment particles, such as titanium dioxide or zinc oxide, coated or not, as an agent improving the UV-absorbing capacities of said composition of a water-soluble comb-type copolymer having a (meth) acrylic acid backbone and poly (alkylene glycol) side chains. The present invention is based on the combination of a UV-filtering agent, namely the pigment particles such as TiO ₂ and / or ZnO, coated or not, and a particular (meth) acrylic copolymer. The present invention also relates to a sunscreen composition comprising, in a cosmetically acceptable support, from 0.1 to 50% by weight, relative to the total weight of the composition, of pigment particles, such as TiO 2 and / or ZnO UV radiation and at least one water-soluble comb-type copolymer having an acid (meth) acrylic backbone and poly (alkylene glycol) side chains as the filtering agent,

By "pignientary particle" is meant a mineral compound, for example titanium dioxide (TiO ₂ ), zinc oxide (ZnO), cerium oxide (CeO ₂ ) and iron oxides (FesO ₄ , Fe ₂ 0 ₃ ), coated or not, or a mixture of these compounds. These pigment particles may, for example, have undergone one or more surface treatments of chemical, electronic, mechanochemical and / or mechanical nature. These particles may have undergone a surface treatment with substances, for example of hydrophobic nature. hydrophilic or mineral. For example, for the surface treatment of pigment particles, one or more of the following compounds are used: amino acids, beeswax, fatty acids, fatty alcohols, anionic surfactants, lecithins, sodium salts, potassium, zinc, iron or aluminum fatty acids, metal alkoxides (titanium or aluminum), polyethylene, silicones, proteins (collagen, elastin), alkanolamines, silicon oxides, metal oxides or sodium hexarnetaphosphate. The pigment particles according to the invention possess UV radiation filtration properties and thus constitute a UV-A filter and / or a UV-B filter. These particles are therefore characterized by their photoprotective activity. They may be in the form of micrometric and / or submicron and / or nanometric particles. The structures of these particles may be amorphous and / or crystallized and in rutile and / or anatase form for TiO ₂ . TiO ₂ particles are conventionally obtained by conventional industrial processes from ore, for example by a sulphate process or by a chloride process. According to the invention, the pigment particles are in predispersed form (for example suspensions or dispersions in a liquid) or in powder form. Such particles are commercially available.

By "poly (alkylene glycol)" is meant a polymer of an alkylene glycol derived from an olefinic oxide. The poly (alkylene glycol) according to the present invention is, for example, poly (ethylene glycol), poly (propylene glycol), poly (butylene glycol) or a poly (alkylene glycol) containing a proportion of ethylene-oxy group and / or a proportion of propylene-oxy group and / or a proportion of butylene-oxy group. The poly (alkylene glycol) according to the present invention may for example comprise a major proportion of ethyleneoxy group in combination with a secondary proportion of propyleneoxy group. Specific examples of the alkylene glycol polymer include: polyalkylene glycols having an average molecular weight of 1,000, 4,000, 6,000, 10,000 and 20,000 g / mol (in the case of polyethylene glycol) 1000 ₅ PEG-4 QQ0 ₅ PEG-6000, PEG 10,000 PEG ₅ 20 000); polyethylene polypropylene glycols having a percentage of ethylene oxide of between 20 and 80% by weight and a percentage of propylene oxide of between 20 and 80% by weight,

More particularly, the copolymer according to the invention consists of:

a) at least one acrylic acid monomer and / or a methacrylic acid monomer and / or any of their salt,

b) at least one monomer of formula (I):

according to which:

R represents a polymerizable unsaturated functional group, in particular acrylate, methacrylate, methacrylurethane, vinyl or allyl,

R ⁵ denotes hydrogen or an alkyl group having 1 to 4 carbon atoms, X represents a structure comprising n unit (s) of ethylene oxide EO and m unit (s) of propylene oxide OP, arranged alternatively or statistically, m and n are 2 integers, between 0 and 150, at least one of which is non-zero, said copolymer having a molecular weight of between 25,000 g / mol and 50,000 000 g / mol, as detonated by size exclusion chromatography (CES) or in English "Gel Permeation Chromatography" (GPC).

Some (meth) acrylic comb copolymers are described in the technical field of cosmetic compositions. In particular, the patent application FR 2 973 241 (Coatex) describes shampoos in which they are incorporated and confer a styling effect and rinse elimination more marked. This patent application does not, however, describe the effect associated with the use of a particular (meth) acrylic copolymer as an agent improving the UV-absorbing performance of sunscreen compositions incorporating pigment particles. This application does not describe either sunscreen compositions having such characteristics. Patent application FR 2 974 502 for its part describes the use of certain (meth) acrylic copolymers as a color developing agent in a cosmetic composition for make-up, such copolymers having a molecular mass of between 20,000 and 250 000 g / mol. This patent application does not, however, describe the effect associated with the use of a particular (nitreth) acrylic copolymer as a UV-absorbing performance enhancing agent for sunscreen compositions incorporating titanium dioxide particles and / or zinc oxide, the patent application 12/02617 filed October 2, 2012 not yet published (Coatex) describes the use of certain (meth) acrylic copolymers comb to homogenize the cosmetic compositions of the mascara type comprising a film-forming polymer and a mineral dye pigment of the iron oxide type. The cosmetic compositions of the mascara type do not contain TiO ₂ and / or ZnO.

According to one embodiment of the present invention, the copolymer does not comprise any hydrophobic monomer, such as, for example, selected from the group consisting of styrene, para-tert-butylstyrene, (meth) acrylic esters having from 1 to 4 carbon atoms on the ester group.

The compositions according to the present invention are sunscreen compositions. These compositions are also called sunscreen compositions or photoprotective compositions for filtering, blocking or absorbing UV radiation (in English "UV blocker", "UV filter" or "UV absorber"),

By "agent improving the UV-absorbing capacities of the sunscreen composition" is meant an agent that makes it possible to obtain a cosmetic product whose absorption capacities for UV-A and / or UV-B radiation are improved. Equivalently, the terms "UV-absorbent capacity developer agent" are used. In the context of the present invention, the terms "improve", "enhancer" or "developer" mean to increase or respectively imply an increase in the absorbance values of the UV spectrum on wavelengths at least between 310 and 340 nm, for example between 290 and 400 nm, compared to those obtained for the same formulation of sunscreen which comprises the same determined quantity of pigment particles, but no agent according to the invention.

Without wishing to be bound by any theory, with regard to the results obtained, the inventors are of the opinion that the copolymers according to the invention have properties which make it possible to space the pigment particles in the formulations, but also to maintain the separation of these particles during the step of forming the film on the surface of the skin and thus to improve the optical path of the light. The UV absorbance of the sunscreen compositions is measured by means of a spectrometer from a sample of the compositions diluted in isopropanol.

The pigment particles according to the invention preferably have an average particle size greater than 5 nm and less than 100 nm. According to a particularly preferred embodiment of the invention, this size preferably varies from 10 nm to 50 nm. .

As indicated above, the pigment particles may be coated or uncoated.

The coated pigment particles are pigments which have undergone one or more surface treatments of a chemical, electronic, mechanochemical and / or mechanical nature with compounds, such as amino acids, beeswax, fatty acids, fatty alcohols , aniomic surfactants, lecitines, sodium, potassium, zinc, iron or aluminum salts of fatty acids, metal alkoxides (of titanium or aluminum), polyethylene, silicones, proteins (collagen, elastin), alkanolamines, silicon oxides, metal oxides or sodium hexametaphosphate. The silicones used for coating the pigment particles according to the invention are for example chosen from the group containing alkyl silanes, polydialkylsiloxanes, and polyalkylhydrogensiloxanes. For example, the silicones are selected from the group containing octyl trimethyl silane, polydimethylsiloxanes and polymethylhydro-genosiloxanes. The pigment particles according to the invention may have undergone several treatments. For example, before their treatment with silicones, they may have been treated with other surfactants, in particular with cerium oxide, alumina, silica, aluminum compounds, silicon compounds, or mixtures thereof. Examples of pigment particles according to the invention which are commercially available are, for example, coated titanium dioxide particles.

silica, and possibly iron oxide,

silica and / or alumina, and optionally aluminum stearate,

alumina,

silica, alumina and alginic acid,

- Alumina and aluminum laurate.

- iron oxide and iron stearate,

zinc oxide and zinc stearate,

of silica and alumina and treated with a silicone,

silica, alumina, aluminum stearate and treated with a silicone,

silica and treated with a silicone,

of alumina and treated with a silicone,

- triethanolamine,

polydimethylsiloxane (PDMS)

- stearic acid, or

sodium hexametaphosphate.

Examples of commercially available coated titanium dioxide particles are:

- the products of the SUNVEIL range (Ikeda Corporation),

- the products of the MICROTITANRJM DIOXIDE range (Tayca),

- the products of the TIOVEIL ™ or SOLAVEIL ™ range (Croda),

- the products of the EUSOLEX® range (Merck),

- the products of the range TIPÂQUE (Ishihara),

- the products of the TTO range (Miyoshi Kasei),

- the products of the UV-ΉΤΑΝ range (Sachtleben),

~ the products of the TRIsbield range (Tri-K),

- the products of the DAITOPERSION range (Daito Kasei),

- STT products (Kobo). Examples of pigment particles according to the invention and commercially available are, for example, uncoated titanium dioxide particles sold under the trade names;

MICROTITANIUM DIOXIDE (Tayca),

- P25 (Degussa),

- UFTR ((Miyoshï Kasei),

- MiRASUN (Rhodia),

the products of the TIOVEIL ™ (Croda) range. Examples of pigment particles according to the invention that are commercially available are, for example, uncoated zinc oxide particles sold under the trade names:

- Z-COTE (BASF),

- NANOX (Elementis),

- NANOGUARD® and NANGTEK® (Nanophase Technologies Corporation).

Examples of pigment particles according to the invention and commercially available are, for example, zinc oxide particles;

- coated with po! yme & ylhydrogenesiloxane,

- coated with perfluoroalkyl phosphate and copolymer based on perfluoroalkylethyl as a dispersion in cyelopentasiloxane ₅

~ coated with silicone-grafted acrylic polymer, dispersed in cyclodimethylsiloxane,

- coated with silica and polymethylsilsesquioxane,

treated with alumina and dispersed in the ethylhexyl methoxycinnamate / PVP ~ hexadecene / methicone copolymer mixture,

- 55% dispersed in C12-C15 alcohols benzoate with hydroxystearic acid polycondensate,

in a 40% dispersion in Finsolv TN, benzoate of C12-C15 alcohols, in dispersion in oxyethylenated cyclopolymethylsiloxane / polydimethylsiloxane, containing 30% or 50% of zinc nano-oxides coated with silica and polymethylhydrogensiloxane.

Examples of commercially available coated zinc oxide particles are: the products of the OXIDE ZINC CS range (Toshibi),

- the products of the NANOGUARD® and NANOTEK® range (Nanophase Technologies Corporation),

- the products of the DAITOPERSION range (Daito Kasei),

- the products of the NANOX GEL range (Elementis),

- the products of the ESCALOL range or Z range (ISP),

- the products of the SPD range (Shin-Etsu).

Examples of pigment particles according to the invention and commercially available are, for example, uncoated iron oxide particles sold under the trade names:

- NANOGUARD® and NANOTEK® (Nanophase Technologies Corporation),

TY-220 (Mitsubishi) Examples of commercially coated iron oxide particles available are:

- NANOGUARD® and NANOTEK® (Nanophase Technologies Corporation).

Formulations which contain mixtures of pigment particles, in particular of titanium dioxide and of cerium dioxide, of which the titanium dioxide / cerium dioxide dioxide mixture is coated with silica, as well as the mixture of titanium dioxide and zinc dioxide, may also be mentioned. coated with alumina, silica and silicone or titanium dioxide / zinc dioxide mixture coated with alumina, silica and glycerine.

The sunscreen composition according to the invention also comprises a water-soluble copolymer which, according to one aspect of the present invention, has a molecular mass of between 300 000 and 50 000 000 g / mol, for example between 300 000 and 20 000 000 g. As an aspect of the present invention, the water-soluble copolymer has a molecular weight of between 300,000 and 300,000. 000 000 g / mol, as determined by size exclusion chromatography (CES).

According to another aspect of the present invention, the water-soluble copolymer has a molecular weight of between 1,000,000 and 15,000,000 g / mol. The sunscreen composition according to the invention also comprises a water-soluble copolymer which, according to another aspect of the present invention, has a molecular mass of between 25,000 and 15,000,000 g / mol, for example between 25,000 and 1,000,000. g / mol, as determined by steric exclusion chromatography (CES),

According to one aspect of the present invention, the water-soluble copolymer has a molecular weight of between 25,000 and 500,000 g / mol, as determined by size exclusion chromatography (CES).

According to another aspect of the present invention, the water-soluble copolymer has a molecular weight of between 25,000 and 400,000 g / mol.

According to one aspect of the invention, said water-soluble copolymer is such that n is a non-zero integer less than 150 and m is an integer between 0 and 150. According to this aspect of the invention, m optionally takes the value of zero, which means that the poly (alkylene glycol) side chains of the copolymer, according to this. aspect of the invention, include only ethylene oxide units; in other words, according to this aspect of the invention, they are poly (ethylene glycol) side chains,

According to one aspect of the invention, said water-soluble copolymer is such that n is an integer between 15 and 150 εΐ m is an integer between 0 and 150.

According to one aspect of the invention, said water-soluble copolymer is such that n and m are two integers of which at least one is non-zero and n + m> 17.

According to another aspect of the invention, said water-soluble copolymer is such that n and m are two integers of which at least one is non-zero and n + m> 50. According to another aspect of the invention, the R function of monomer of formula (I) represents the methacrylate function.

According to another aspect of the invention, the function R 'è & monomer of formula (I) represents H or Q な.

According to another aspect, the R function of the monomer of formula (I) represents the methacrylate function and the R ^s function of the monomer of formula (I) represents H, According to an aspect of the present invention, said copolymer consists, based on the total weight of the copolymer, of;

a) 5 to 19% by weight of monomers of acrylic acid and / or methacrylic acid and / or any of their salt, and

b) 81 to 95% by weight of at least one monomer of formula (I).

According to another aspect, said copolymer consists, relative to the total weight of the copolymer, of:

Al) 5 to 10% by weight of acrylic acid monomers and / or any of its salt,

A2) 5 to 9% by weight of methacrylic acid monomers and / or any of its salt, and

B) 85 to 95% by weight of at least one monomer of formula (I), According to one aspect of the invention, said composition comprises from 0.05 to 5% by weight of active ingredient of said copolymer, relative to the weight total of the composition.

According to one aspect of the invention, said composition comprises from 0.1 to 3% by weight of active material of said copolymer, relative to the total weight of the composition. According to one aspect of the invention, said composition comprises from 0.2 to 50% by weight of pigment particles as described above. According to another aspect of the invention, said composition comprises from 0.4 to 40% by weight of particles of these pigment particles, for example from 0.4 to 30% by weight. According to one aspect of the invention, said formulation comprises at least titanium dioxide and / or zinc oxide and / or cerium oxide and / or coated or non-coated iron oxides.

According to another aspect of the invention, said formulation further comprises another pigmentary inorganic filler selected from the group consisting of calcium carbonate, zinc oxide, kaolin and a silicate.

In yet another aspect, the pigment mineral fillers of the sunscreen formulation of the present invention comprise:

from 30 to 90% by weight of particles of titanium dioxide and / or zinc oxide, coated or not, and from 10 to 70% by weight of at least one other inorganic filler pigment coated or not _s _s selected from the group consisting of calcium carbonate, zinc oxide, kaolin and silicates. The sunscreen formulations of the present invention potentially comprise other complementary organic photoprotective agents, UV-A and / or UV-B active, hydrophilic, lipophilic, or insoluble in commonly used cosmetic solvents.

Said other additional hydrophilic or lipophilic organic photoprotective agents are for example selected from anthranilates; dibenzoylmethane derivatives; cinnamic derivatives; salicylic derivatives, camphor derivatives; benzophenone derivatives; diphenylacrylate derivatives; triazine derivatives; benzotriazole derivatives; benzalmalonate derivatives; benzimidazole derivatives; imidazolines; bis-benzoazolyl derivatives; p-aminobenzoic acid derivatives (PABA); methylene bis (hydroxyphenyl benzotriazole) derivatives; benzoxazole derivatives; filter polymers and silicone filters; dimers derived from alkylstyrene; 4,4-diarylbutadienes; and their mixtures.

The additional photoprotective agents may be present in the formulations according to the invention in proportions ranging from 0.01% to 20% by weight relative to the total weight of the composition, for example ranging from 0.1% to 10% by weight relative to to the total weight of the formulation.

The compositions in accordance with the present invention may also comprise conventional cosmetic adjuvants chosen from softeners, humectants, opacifiers, stabilizers, emollients, silicones, defoamers, perfumes, preservatives, anionic surfactants, cationiqueSj nonionic, zwitterionic or amphoteric ₅ loads _f propellants, basifying or acidifying agents or any other ingredient usually used in cosmetics and / or dermatological composition.

The medium of the sunscreen composition according to the present invention is a physiologically and / or cosmetically acceptable medium. It may for example be monophasic of aqueous or non-aqueous / anhydrous type, that is to say essentially consisting of one or more oils. The composition according to the present invention may also be multisphasic, that is to say comprise several phases. For example The composition according to the present invention may be biphasic and comprise at least one anhydrous phase containing at least one polar oil.

The compositions according to the invention may be in any form suitable for topical application, in particular in the form of aqueous gels, in the form of emulsions obtained by dispersing a fatty phase (also called oily phase) in an aqueous phase ( H / E) or conversely (W / O) or multiple emulsions (for example E / H / E or H7E / H or H7H / E), They can be more or less fluid and have the appearance of a cream white or colored, an ointment, a milk, _a!} ote a serum, a paste, powder, solid stick and may optionally be packaged as an aerosol and be in the form of foam or These compositions are prepared according to the usual methods,

Thus, according to one aspect of the present invention, the sunscreen composition comprises, based on the total weight of the composition, a) from 10% to 99.9% by weight of aqueous phase,

b) 0.1% to 90% by total weight of non-aqueous phase,

the sum a) + b) being equal to 100%.

According to another aspect of the present invention the sunscreen composition comprises, based on the total weight of the composition, a) from 15% to 99.5% by weight of aqueous phase,

b) 0.5% to 85% by total weight of non-aqueous phase,

the sum a) + b) being equal to 100%.

According to still another aspect of the present invention, the sun protection composition comprises, with respect to the total weight of the composition, of: a) 50% to 70% by weight of aqueous phase,

b) 30% to 50% by total weight of non-aqueous phase,

the sum a) 4- b) being equal to 100%. The aqueous phase of the composition may consist of a mixture of water and organic solvents miscible with water (miscibility in water greater than 50% by weight at 25 ° C). These solvents are, for example, chosen from lower monoalcoois comprising from 1 to 5 carbon atoms such as ethanol, isopropanol and glycols containing from 2 to 8 carbon atoms such as propylene glycol and ethylene glycol. 1,3-butylene glycol, dipropylene glycol, C3-C4 ketones, C2-C4 aldehydes and ethoxylated alcohols,

The non-aqueous phase (or fatty phase) of the cosmetic composition according to the present invention is capable of comprising natural or synthetic ingredients immiscible with water, liquid at room temperature (25 ° C.) and / or solid at room temperature. may in particular be selected from the group consisting of waxes, oils, pasty fatty substances, gums and mixtures thereof.

An object of the present invention also consists of a method for preparing a sunscreen composition, consisting in implementing the copolymer according to the invention.

The sunscreen composition according to the present invention is generally not rinsed, but it can be rinsed if it constitutes a cleaning product including foaming.

The subject of the invention is also a process for the cosmetic treatment of a keratin material such as the skin, eyelashes, eyebrows, nails or mucous membranes, characterized in that a composition such as is applied to the keratin material defined above.

According to another aspect, the invention also relates to a cosmetic assembly comprising:

i) a container defining at least one compartment, said container being closed by a closure element; and

ii) a composition as described above and disposed within said compartment. The container can be in any suitable form. It may especially be in the form of a bottle, a tube, a pot, a case, a box, a bag or a case. Said copolymer according to the invention is obtained by known methods of conventional radical copolymerization in solution, in direct or inverse emulsion in bulk, in suspension or precipitation in appropriate solvents, in the presence of known initiators and transfer agents, or also by controlled radical polymerization processes such as the method called Reversible Addition Fragmentation Transfer (RAFT), the method called Atom Transfer Radical Polymerization (ATRP), the method called Nitroxide Mediated Polymerization (NMP) or the method called Cobaloxime Mediated Free Radical Polymerization.

The examples which follow make it possible to better understand the present invention without limiting its scope.

EXAMPLES

In each of the following examples, the molecular weight of the copolymers according to the invention is determined by size exclusion chromatography (CES).

Such a technique implements a WATERS ™ brand liquid chromatography apparatus with two detectors. One of these detectors combines the static dynamic scattering of light at an angle of 90 ° C to the viscometry measured by a VIESCOK ™ MALVERN ™ detector viscometer. The other of these detectors is a WATERS ™ brand refractometric concentration detector

This liquid chromatography apparatus is provided with steric exclusion columns appropriately selected by the trade in order to separate the different molecular weights of the polymers studied. The liquid phase of elution is an aqueous phase containing 1% of KNO ₃ .

In a detailed manner, according to a first step, the polymerization solution in the eluent of the CES, which is a 1% solution of KNO ₃ , is diluted to 0.9% by weight. Then filtered at 0.2 μχη. 100 μΐ _^ are then injected into the chromatograph (eluent: a 1% solution of KN0 _3).

The liquid chromatography apparatus contains an isocratic pump (WATERS ™ 515) whose flow rate is set at 0.8 ml / min. The chromatography apparatus also comprises an oven which itself comprises in series the column system. next: "no precolumn type GUARD COLUMN ULTRAHYDROGEL WATERS ™ 6 cm long and 40 mm internal diameter, a linear column type ULTRAHYDROGEL WATERS ™ 30 cm long and 7.8 mm inner diameter and two columns ULTRAHYDROGEL 120 ANGSTROM WATERS ™ 30 cm long and 7.8 mm inside diameter. The detection system consists on the one hand of a RI WATERS ™ 410 type refractometric detector and on the other side of a double viscometer detector and light diffusion at a 270 ° angle of 90 °. DUAL DETECTOR MALVERN ™. The oven is heated to a temperature of 55 ° C. and the refractometer is heated to a temperature of 45 ° C.

The chromatography apparatus is calibrated with a single standard of PEO 19k PoiyCAL ™ MALVERN ™.

In the following examples, the measurement of the ultraviolet absorbance (UVA & UVB) is as follows:

The measurements are performed on a Genesys UV UV ™ Spectrometer (Cole Parmer), equipped with Rotilabo-Einmal Kuvetten PS vats, 4.5 mL. In a practical manner, the apparatus is preheated 10 minutes before use. A first measurement is first made using a vessel filled with 3.8 ml of isopropanol (the "white"). The measurement is then carried out with a vat filled with 3.8 ml of the homogeneous solution to be tested, that is to say 0.05 g of the solar formulation to be tested, diluted in 40 g of isopropanol. The absorbance is then measured at each wavelength between 290 nm and 400 nm.

The organoleptic properties of various solar compositions formulated at t = 1 month are also evaluated. The evaluation is performed at room temperature.

The following criteria are taken into account:

Spreading (Coverage), Texture (smooth, presence of lumps, grains, "flannel" or spinning appearance), Odor (appearance or not of odor), Color (variation of homogeneity), Surface (smooth or not smooth) ).

The viscosity of said formulations is measured using a Brookfield viscometer, model RVT. Before measuring the viscosity, each of the formulations is allowed to stand for 24 hours at 25.degree. The mobile must be centered with respect to the opening of the bottle. The viscosity is then measured at 20 rpm using the appropriate module. The viscometer is allowed to rotate until the viscosity is stable. Finally, the viscoelasticity (or consistency) of different formulations is carried out using a Haake-RheoStress RS 150 rheometer. The variation of the modulus G * (Pa) as a function of the stress τ (scan of 0 at 800 Pa) is measured at 25 ° C, thanks to the cone-plane module (1 °).

In addition, a stability test of different sun protection formulas is carried out:

- at t = 3 months - Sample conditioned at 45 ° C

~ to t =! week - Sample conditioned at 60 ° C

- Sample having undergone a number of freeze / thaw cycles.

The following potential instabilities are observed: phase shift, creaming, exudation, release, deposition / sedimentation.

Example 1 - Sunscreen

This example illustrates the use of an agent according to the invention in an SPF 25 sunscreen formulation, from the following ingredients (the figures in the last column indicate the percentages by weight relative to the total weight of the composition):

Tables .1 Protocol for preparing the formulation:

Phase A: the various ingredients are introduced with stirring and the medium is heated to 65 ° C .;

- Phase B: in another beaker, all the ingredients except B-12 and B-13 are mixed, and heated to 65 ° C with stirring;

After obtaining a homogeneous phase B, ingredient B-12 as well as ring ingredient B-13 are dispersed with stirring;

the phases A and B are mixed so as to obtain a viscous emulsion; - Phase C: adding with moderate stirring the polymer C-15 (if present) and titanium dioxide C-14 (in the form of a powder);

- The formulation is finished by adding ingredient D-16; - The pH is measured and verified to be between 6.7 and 7.0.

Table 2 summarizes all of the polymers that were used as ingredient C-15 in the tests of this Example 1.

It is noted that the amount of titanium dioxide indicated in the table is expressed as a quantity Y, that is to say a percentage by weight relative to the total weight of the composition. By way of example, if Y is 5%, 5 g of C-15 is added for a formulation of 100 g of finished product.

Also, to the extent that the amount of titanium dioxide is varied in the formulations, the table indicates this variation by indicating a percentage relative to the amount of T1O ₂ used in the reference formulation (test 1-1) . By way of example, Test 1-2 employs a quantity of titanium dioxide reduced by 20% relative to the reference (test 1-1), ie 80% of the amount of TiO 2 of the reference formulation.

REF: Reference / AA: Previous Art / INV: Invention / HINV: Without Invention / CONT: Control / NA: not applicable

Test 1-3: The ingredient C-15 is here a dispersant for TiO ₂ of the type Polyglyceryl-10 Decaoleate

The UVA and UVB absorbance spectra are shown in Figures I and 2.

Figure 1 demonstrates that: - by decreasing the amount of titanium dioxide by 20% by weight in the formulation, the UV absorbance of the formulation is reduced (test 1-2 of test 1); and

the polymers according to the invention are not UV filters (tests 1-13 and 1-14). that is, they are not substances capable of filtering UV radiation.

Figure 2 shows that:

the polymers of tests 1-3 and 1-4 do not make it possible to compensate for the reduction of 20% of TiO 2, their UV absorbance spectrum being generally lower than that of test 1-2 (reference - 20% TiO ₂ );

the polymers of tests 1-5 to 1-12 make it possible to compensate, at least in part, for the loss of TiO 2, their UV absorbance spectrum being generally greater than that of test 1 -2 (reference - 20% TiO ₂ ) ;

the test polymer 1-5 makes it possible to completely compensate for the 20% loss of TiO 2 relative to the reference (test 1-1), its UV absorbance spectrum being generally equivalent to that of test 1-1 ( reference);

the polymers of the tests 1-11 and 1-12 make it possible not only to compensate, but, moreover, to improve the UV absorbance of the formulation, their UV absorbance spectrum being greater than that of the test 1-1 (reference with 100% TiO2). Thus, it is demonstrated that despite the decrease in the amount of Tii¼ in sunscreen, the addition of one of the polymers according to the invention makes it possible to compensate, at least in part, the UV absorbance of sunscreens. Organoleptic properties. Brookfield viscosity & consistency:

Evaluation of the stability of the formulations:

The stability test at t = 1 week and at t = 3 months carried out on a formulation comprising the polymer of test 1-1 (reference) and in parallel on a formulation comprising the polymer of test 1-9 does not show no significant difference on the set of criteria considered, namely no phase shift, crérnage, release and no exudation or sedimentation.

In addition, the two formulations have a number of freeze-thaw cycles before identical destabilization, namely five.

Example 2 - Sprayable Solar Lotion

This example relates to the implementation of a polymer according to the invention in a sprayable sunscreen formulation, which is characterized by a particular rheological profile, from the following ingredients (the figures in the last column indicate the percentages by weight relative to to the total weight of the composition):

Protocol for preparing the formulation:

- Phase A: all the ingredients of Phase A are mixed;

Phase B: In another beaker, B-3 is introduced, then B-4 and then B-5 are successively dispersed. Ingredients B-6, B-7, optionally B-8 and finally B-9 are then added. - Phase B is then introduced into phase A.

- Phase C: dilute C-11 in C-10. This mixture is introduced into the mixture Phase A / Phase B.

- The formula is homogenized for 1 minute.

the formulation is neutralized with D-12 (pH = 5.7 at 6.2). Finally, it is added to the mixture E-13. Table 5 summarizes all the polymers that were used as ingredient B-8 in the tests of this Example 2.

It is noted that the amount of titanium dioxide indicated in the table is expressed as a quantity Y, that is to say a percentage by weight relative to the total weight of the composition. By way of example, if Y is 0.5%, 0.5 g of B-8 is added for a formulation of 100 g of finished product. Also, since the amount of titanium dioxide in the formulations is varied, the table indicates this variation by indicating a percentage with respect to the amount of TiO ₂ used in the reference formulation (test 2-1). .

By way of example, test 2-5 implements a quantity of titanium dioxide reduced by 20% relative to the reference (test 2-1), ie 80% of the amount of TiO ₂ of the formulation of reference.

The additive of the prior art used is dispersant of the Polyglyceryl-10 Decaoleate type.

The UVA and UVB absorbance spectra are shown in Figure 3.

Figure 3 demonstrates that:

- by reducing the amount of titanium dioxide by 20% or 40% by weight in the formulation, the absorbance of the formulation is significantly reduced (test 2-2 and test 2-3 vs test 2-1); and

the polymer of test 2-4 (prior art) does not make it possible to compensate for the 20% reduction in TiO ₂ , its UV absorbance spectrum being generally lower than that of test 2-2 (reference 20 % TI02);

the polymers of tests 2-5 to 2-8 make it possible to compensate, at least in part, for the loss of Ti0 ₂ , its UV absorbance spectrum being generally greater than that of test 2-2 (reference - 20% TiO2);

the polymers of tests 2-5, 2-6 and 2-8 make it possible not only to compensate for the 20% loss of TiO ₂ , but also to improve the absorbance of the formulation on the UV spectrum, their spectrum of UV absorbance being higher than that of test 2-1 (reference with 100% T102).

Organoleptic properties. Brookfield Viscosity & Consistence:

Evaluation of the stability of the formulations:

The t-1 week stability test carried out on a formulation comprising the polymer of test 2-1 (reference) and in parallel on a formulation comprising the polymer of test 2-6 (invention) shows no significant differences. on the set of criteria considered, namely no phase shift, creaming, release and no exudation or sedimentation.

The stability test at t = 3 months carried out on a formulation comprising the polymer of test 2-1 (reference) and in parallel on a formulation comprising the polymer of test 2-6 (invention) shows a difference concerning exudation criterion: while the formulation comprising the reference polymer shows a slight exudation at t = 3 months, this instability is not observed for the formulation comprising a polymer according to the invention.

It is thus demonstrated that the additives according to the invention are effective not only in formulations of the cream type (Example 1), but also in sprayable lotions (Example 2). Despite a reduction of 20% or even 40% by weight of the initial amount of UV filters of the TiCh type, the addition of the additives according to the invention makes it possible to maintain at least in part, or even to increase significantly the performances UV absorptive solar compositions (cream or lotion for example), Example 3 - Sunscreen

This example illustrates the use of an agent according to the invention in an SPF 25 sunscreen formulation, from the following ingredients (the figures in the last column indicate the masses in grams relative to the total weight of the composition):

Protocol for preparing the formulation:

- Phase B: In another beaker, all the ingredients are mixed, except B-12 and B-1 3, and heated to 65 ° C with stirring;

After obtaining a homogeneous phase B, ingredient B-12 and ingredient B-13 are dispersed with stirring;

Phase A and B are mixed in order to obtain a viscous emulsion;

Phase C: C-15, if present, is added under very moderate stirring, followed by ingredient C-14, which is titanium dioxide marketed by Croda, and is in a form dispersed in an oil. cosmetic;

- the formulation is finished by adding ingredient D-16; and

the pH is measured and it is verified that it is in the range 6.7 to 7.0.

Table 8 summarizes all the polymers used as ingredient C-15.

It is noted that the amount of titanium dioxide indicated in the table is expressed as a quantity Y, that is to say a percentage by weight relative to the total weight of the composition. By way of example, if Y is equal to 15%, 15 g of C-14 are added for a formulation of 100 g of finished product.

Also, since the amount of titanium dioxide is varied in the formulations, the table indicates this variation by indicating a percentage with respect to the amount of TiO ₂ used in the reference formulation (test 3-1). .

By way of example, test 3-3 implements a quantity of titanium dioxide reduced by 20% relative to the reference (test 3-1), ie 80% of the amount of TiO ₂ of the formulation of reference.

The UVA and UVB absorbance spectra are shown in Figure 4.

FIG. 4 demonstrates that the polymers of tests 3-3 and 3-4 make it possible not only to compensate for the 20% loss of TiO _2, but also to improve the UV absorbance of the formulation (its absorbance spectrum being higher than that of test 3-2, reference).

Example 4 - Sunscreen with Zinc Oxide

This example illustrates the use of an agent according to the invention in a sunscreen formulation, from the following ingredients (the figures in the last column indicate the masses in grams relative to the total weight of the composition):

The preparation protocol of the formulation is identical to that of Example 1. The titanium dioxide is replaced by zinc oxide (commercially available) in a powder form.

Table 10 summarizes all the polymers used as ingredient C-15.

The absorbance spectra UVA and UVB are shown in FIG. 5,

FIG. 5 demonstrates that the polymer of tests 4-3 and 4-4 not only compensates for the 20% loss of ZnO, but also improves the absorbance of the formulation (its absorbance spectrum being greater than that of the formulation). test ₅ 4-2 reference).

It is thus demonstrated that the additives according to the invention are effective in formulations of the sunscreen type (Examples 1, 3 and 4) irrespective of the form in which the particles of titanium dioxide (powder or dispersed in an oil) occur. or zinc oxide particles (powder) as UV-absorbing filters, or cosmetic compositions of the sprayable type (Example 2).

Claims

1. Use of a water-soluble copolymer as an agent improving the UV~absorbing capacities of sun protection compositions comprising particles of titanium dioxide and/or zinc oxide, _said copolymer being made up of;

a) at least one monomer of acrylic acid and/or one monomer of methacrylic acid and/or any of their salts,

b) at least one monomer of formula (I):

according to which:

R represents a polymerizable unsaturated function, in particular acrylate, methacrylate, methacrylurea, vinyl or allyl,

R' designates hydrogen or an alkyl group having 1 to 4 carbon atoms, randomly or regularly,

m and n are 2 integers, between 0 and 100, at least one of which is non-zero, said copolymer having a molecular mass of between 25,000 g/mol and 50,000,000 g/mol, as determined by CES,

2. Sun protection composition, comprising, in a cosmetically acceptable support, from 0.1 to 50% by weight, relative to the total weight of the composition, of titanium dioxide and/or zinc oxide as UV radiation filtering agents and at least one copolymer consisting of: a) at least one acrylic acid monomer and/or one methacrylic acid monomer and/or any of their salts,

b) at least one monomer of formula (I):

according to which:

R represents a polymerizable unsaturated function, in particular acrylate, methacrylate, methacrylurethane, vinyl or allyl,

R' denotes hydrogen or an alkyl group having! with 4 carbon atoms,

m and n are 2 integers, between 0 and 100, at least one of which is non-zero, said copolymer having a molecular mass of between 25,000 g/mol and 50,000 g/mol, as determined by CES.

3. Composition according to claim 2, according to which said water-soluble copolymer has a molecular mass of between 300,000 and

1,000,000 g/mol.

4. Composition according to claim 2, wherein said water-soluble copolymer has a molecular mass of between 25,000 and 500,000 g/mol.

5. Composition according to any one of claims 2-4, according to which said water-soluble copolymer is such that n and m are two integers, at least one of which is non-zero and n+m > 17.

6. Composition according to any one of claims 2-5 ₃ according to which the R function of the monomer of formula (I) represents the methacrylate function.

7. Composition according to any one of claims 2-6, according to which the function R' of the monomer of formula (ï) represents H or C¾.

8. Composition according to any one of claims 2-7, according to which said copolymer consists of: a) 5 to 19% by weight of monomers of acrylic acid and/or nithacrylic acid and/or any of their salts, and

b) 81 to 95% by weight of at least one monomer of formula (I).

9. Composition according to any one of claims 2-8, according to which said copolymer consists of:

Al) 5 to 10% by weight of acrylic acid monomers and/or any of its salt,

A2) 5 to 9% by weight of methacrylic acid monomers and/or any of its salts, and

B) 85 to 95% by weight of at least one monomer of formula (I).

10, Composition according to any one of claims 2-9, according to which said composition comprises from 0.05 to 5% by weight of active material of said copolymer, relative to the total weight of the composition.

11. Composition according to any one of claims 2-10, according to which said composition comprises from 0.2 to 50% by weight of pigment particles.

12. Composition according to any one of claims 2-11, according to which said composition comprises other complementary organic photoprotective agents, UV-A and/or UV-B active, hydrophilic, _lipophilic or insoluble in commonly used cosmetic solvents.

13. Composition according to any one of claims 2-12, according to which said composition comprises at least one cosmetic adjuvant chosen from the group consisting of softeners, humectants, opacifiers, stabilizers, emollients, silicones, agents anti-foam, perfumes, preservatives, anionic, cationic, non-ionic, zwitterionic or amphoteric surfactants, fillers, propellants, alkalizing or acidifying agents or any other ingredient usually used in the cosmetic and/or dermatological field.