SAFOUANE MAHASSINE (FR)
MAGNAN ANNE (FR)
PORTAL JULIEN (FR)
WO2008097223A1 | 2008-08-14 | |||
WO2000071084A1 | 2000-11-30 | |||
WO2016097274A1 | 2016-06-23 |
US20110293543A1 | 2011-12-01 | |||
FR3014875A1 | 2015-06-19 |
CLAIMS 1. Composition, especially a cosmetic composition, comprising: (a) at least one organic anti-UV screening agent present in an encapsulated form; and (b) at least one dispersion, in a non-aqueous medium containing at least one hydrocarbon-based oil, of particles of at least one polymer, the particles being surface- stabilized by a stabilizer; the polymer of the particles: (i) being a G-C4 alkyl (meth)acrylate polymer or copolymer, (ii) being present in the composition in a content ranging from 1% to 10% by weight relative to the total weight of the composition; and (iii) having a glass transition temperature of less than 150°C; the stabilizer being an isobornyl (meth)acrylate polymer chosen from isobornyl (meth)acrylate homopolymer and statistical copolymers of isobornyl (meth)acrylate and of Ci-C4 alkyl (meth)acrylate present in an isobornyl (meth)acrylate/Ci-C4 alkyl (meth)acrylate weight ratio of greater than 4. 2. Composition according to Claim 1, characterized in that it comprises, as organic anti-UV screening agent present in an encapsulated form, at least one organic UVA screening agent and/or at least one organic UVB screening agent, preferably at least one organic UVA screening agent and at least one organic UVB screening agent. 3. Composition according to Claim 2, in which the organic UVA screening agent is chosen from water-soluble dibenzoylmethane derivatives, water-soluble camphor derivatives and mixtures thereof in any proportions, preferably from butyl methoxydibenzoylmethane, terephthalylidene dicamphor sulfonic acid and mixtures thereof in any proportions, and is in particular butyl methoxydibenzoylmethane. 4. Composition according to Claim 2, in which the organic UVB screening agent is chosen from salicylic derivatives, cinnamates, β,β'-diphenylacrylate derivatives, triazine derivatives and mixtures thereof in any proportions, preferably from ethylhexyl salicylate, ethylhexyl methoxycinnamate, octocrylene, ethylhexyl triazone and mixtures thereof in any proportions, and is preferably octocrylene. 5. Composition according to any one of the preceding claims, in which the content of organic anti-UV screening agent present in an encapsulated form is between 0.5% and 50% by weight, preferably between 1% and 40% by weight, more particularly between 5% and 30% by weight relative to the total weight of the composition. 6. Composition according to any one of the preceding claims, in which the polymer of the particles has a glass transition temperature of between 8°C and 150°C, preferably between 8°C and 120°C, more preferentially between 8°C and 110°C. 7. Composition according to any one of the preceding claims, in which the particles of polymer and of stabilizer of the dispersion are present in a content ranging from 0.2% to 20% by weight, preferably ranging from 0.5% to 10% by weight relative to the total weight of the composition. 8. Composition according to any one of the preceding claims, in which the polymer of the particles is chosen from copolymers of C1-C4 alkyl (meth)acrylate and (meth)acrylic acid or maleic anhydride. 9. Composition according to any one of the preceding claims, in which the stabilizer is chosen from statistical copolymers of isobornyl acrylate/methyl acrylate; statistical copolymers of isobornyl acrylate/ methyl acrylate/ ethyl acrylate; and statistical copolymers of isobornyl acrylate and methyl me hacrylate. 10. Composition according to any one of the preceding claims, in which the hydrocarbon-based oil is apolar and preferably chosen from apolar hydrocarbon-based oils having from 8 to 14 carbon atoms. 11. Composition according to any one of the preceding claims, characterized in that it is in the form of an oil-in-water or water-in-oil emulsion, preferably an oil-in- water emulsion. 12. Composition according to any one of the preceding claims, characterized in that it comprises a water content of between 20% and 75% by weight, preferably between 30% and 70% by weight, more particularly between 40% and 60% by weight, relative to the total weight of the composition. 13. Cosmetic use of a composition as defined according to any one of Claims 1 to 12, for preventing the appearance on the skin, in particular on the face, the neckline, the arms, the hands and/or the shoulders, of darker and/or more coloured marks which give the skin non-uniform colour. 14. Cosmetic use of a composition as defined according to any one of Claims 1 to 12, for preventing premature ageing of the skin, especially on the face, the neckline, the arms, the hands and/or the shoulders. 15. Cosmetic use according to Claim 14, in order to prevent a loss of firmness and/or elasticity and/or tonicity and/or suppleness of the skin, the formation of wrinkles and fine lines, a dull complexion, and/or a wizened appearance of the skin. 16. Cosmetic use of at least one dispersion, in a non-aqueous medium containing at least one hydrocarbon-based oil, of particles of at least one polymer, the particles being surface- stabilized by a stabilizer; the polymer of the particles: (i) being a Ci-C4 alkyl (meth)acrylate polymer or copolymer; (ii) being present in the composition in a content ranging from 1% to 10% by weight relative to the total weight of the composition; and (iii) having a glass transition temperature of less than 150°C; the stabilizer being an isobornyl (mefh)acrylate polymer chosen from isobornyl (meth)acrylate homopolymer and statistical copolymers of isobornyl (meth)acrylate and C1-C4 alkyl (meth)acrylate present in an isobornyl (meth)acrylate/Ci-C4 alkyl (me h)acrylate weight ratio of greater than 4; in order to increase the Sun Protection Factor of a composition, especially a cosmetic composition, comprising at least one organic UV radiation screening agent present in an encapsulated form. |
The present invention relates to the field of photoprotective cosmetic compositions, also referred to as antisun products or photoprotective products, and also to the corresponding cosmetic treatment processes.
Keratin materials, and in particular the skin, are exposed daily to sunlight.
The term "skin" is intended to mean all of the skin of the body, including the scalp, the mucous membranes, the semi-mucous membranes, and the skin appendages.
The term "skin appendages" is intended to mean the body hair, the eyelashes, the hair and the nails. More particularly, in the present invention, the skin of the neckline, of the neck and of the face, and especially the skin of the face, are considered.
As it happens, it is known that prolonged exposure of the skin to this polychromatic light is capable of inducing skin disorders or else superficial damage.
Due to this exposure, some people will especially see on the skin, and more specifically on the face, the neckline, the arms, the hands and the shoulders, the appearance of darker and/or more coloured marks, giving the skin a lack of uniformity, which for obvious reasons poses aesthetic problems.
To counter these undesirable effects, it is common practice to use photoprotective compositions in which organic or inorganic anti-UV screening agents are formulated.
They generally contain organic UV screening agents and/or inorganic UV screening agents, which function according to their own chemical nature and according to their own properties by absorption, reflection or scattering of the UV radiation. They generally contain mixtures of liposoluble organic screening agents and/or water-soluble UV screening agents.
UVA screening agents advantageously make it possible to screen UV-A radiation, with wavelengths between 320 and 400 nm, which causes tanning of the skin and is liable to induce adverse changes therein, especially in the case of sensitive skin or skin that is continually exposed to solar radiation. UV-A radiation causes in particular a loss of elasticity of the skin and the appearance of wrinkles, thereby leading to premature ageing of the skin.
As for UVB screening agents, they make it possible to screen UV-B radiation, with wavelengths between 280 and 320 nm, which also enables tanning of the epidermis but is liable to cause erythemas and superficial skin burns which may be harmful to natural tanning.
It is thus common to introduce UVA and/or UVB screening agents, in particular organic UVA screening agents and/or organic UVB screening agents, into compositions intended to provide antisun protection.
However, the presence of these screening agents in compositions has cosmetic drawbacks on application, such as a greasy and tacky sensation.
In order to overcome this problem, it has been proposed to use these organic screening agents in an encapsulated form within the composition comprising them. This encapsulation advantageously makes it possible to reduce the tacky and greasy feeling of the composition.
Other than these UVA and UVB screening agents, a composition intended to provide antisun protection also comprises additional agents intended to increase the Sun Protection Factor (SPF) provided by this composition.
However, when UVA or UVB screening agents are present in the composition in an encapsulated form, these additional agents do not make it possible to increase the SPF.
Within the meaning of the invention, sun protection factor (SPF) is intended to mean the ratio between the minimum time necessary to obtain sunburn with an antisun composition and the minimum time without product.
It is expressed mathematically by the ratio of the UV radiation dose necessary to reach the erythemogenic threshold with the anti-UV screening agent to the UV radiation dose necessary to reach the erythemogenic threshold without the anti-UV screening agent.
Thus, the higher the SPF of a composition, the higher the antisun protection afforded by this composition.
Within the meaning of the invention, the terns "UV screening agent" and
"anti-UV screening agent" have the same meaning, and denote screening agents which screen out ultraviolet radiation. Similarly, the terms "anti-UVA screening agent" and "UVA screening agent" have the same meaning, and denote screening agents which screen out UVA radiation. The same applies to the terms in the application related to UVB screening agents.
Thus, there is a need for a photoprotective composition, especially a cosmetic composition, which is neither tacky nor greasy, while having a satisfactory Sun Protection Factor (SPF).
To improve the effectiveness of the screening of the UVB and UVA radiation by the organic screening agents used, it is commonly accepted to use particles referred to as "boosters", making it possible to potentiate the effectiveness of the screening of the UV radiation.
However, these particles are ineffective in the presence of organic screening agents in encapsulated form.
There therefore remains a need to find novel systems making it possible to reinforce the effectiveness of the screening of the UVA and UVB radiation by organic encapsulated UV screening agents.
There is also a need for a means to increase the Sun Protection Factor (SPF) of a photoprotective composition comprising organic anti-UV screening agents present in an encapsulated form.
The aim of the present invention is to satisfy these needs.
Thus, according to a first aspect, the present invention targets a composition, especially a cosmetic composition, comprising:
(a) at least one organic anti-UV screening agent present in an encapsulated form; and
(b) at least one dispersion, in a non-aqueous medium containing at least one hydrocarbon-based oil, of particles of at least one polymer, the particles being surface- stabilized by a stabilizer;
the polymer of the particles:
(i) being a C1-C4 alkyl (meth)acrylate polymer or copolymer;
(ii) being present in the composition in a content ranging from 1% to 10% by weight relative to the total weight of the composition; and
(iii) having a glass transition temperature of less than 150°C; the stabilizer being an isobornyl (meth)acrylate polymer chosen from isobornyl (meth)acrylate homopolymer and statistical copolymers of isobornyl (meth)acrylate and of C1-C4 alkyl (meth)acrylate present in an isobornyl (meth)acrylate/Ci-C4 alkyl (meth)acrylate weight ratio of greater than 4.
The inventors have discovered, unexpectedly and surprisingly, that using a dispersion of particles according to the invention in a composition comprising at least one organic anti-UV screening agent present in an encapsulated form advantageously makes it possible to increase the Sun Protection Factor (SPF).
The use of a dispersion of particles according to the invention in a composition comprising at least one organic anti-UV screening agent present in an encapsulated form advantageously makes it possible to potentiate the effectiveness of the screening of the UV radiation.
Thus, the present invention also relates to the cosmetic use of a composition according to the invention, for preventing the appearance on the skin, in particular on the face, the neckline, the arms, the hands and/or the shoulders, of darker and/or more coloured marks which give the skin non-uniform colour.
Within the meaning of the present invention, the term "preventing" is intended to mean reducing, at least in part, the risk of a given phenomenon occurring, i.e. in the present invention the appearance on the skin of darker and/or more coloured marks which give the skin non-uniform colour, and/or premature ageing of the skin.
The present invention also targets the cosmetic use of a composition according to the invention for preventing premature ageing of the skin, especially the skin of the face, the neckline, the arms, the hands and/or the shoulders, more particularly in order to prevent a loss of firmness and/or elasticity and/or tonicity and/or suppleness of the skin, the formation of wrinkles and fine lines, a dull complexion, and/or a wizened appearance of the skin.
The present invention also targets a non-therapeutic cosmetic process for limiting the darkening of the skin and/or improving the colour and/or uniformity of the complexion, comprising the application, to the surface of the keratin material, of at least one composition according to the invention. It also relates to a non-therapeutic cosmetic process for preventing and/or treating the signs of ageing of a keratin material, comprising the application, to the surface of the keratin material, of at least one composition according to the invention.
The present invention also relates to the cosmetic use of at least one dispersion, in a non-aqueous medium containing at least one hydrocarbon-based oil, of particles of at least one polymer, the particles being surface-stabilized by a stabilizer;
the polymer of the particles:
(i) being a C1-C4 alkyl (meth)acrylate polymer or copolymer;
(ii) being present in the composition in a content ranging from 1% to 10% by weight relative to the total weight of the composition; and
(iii) having a glass transition temperature of less than 150°C;
the stabilizer being an isobornyl (meth)acrylate polymer chosen from isobornyl (meth)acrylate homopolymer and statistical copolymers of isobornyl (meth)acrylate and of C1-C 4 alkyl (meth)acrylate present in an isobornyl (meth)acrylate/Ci-C4 alkyl (meth)acrylate weight ratio of greater than 4;
in order to increase the Sun Protection Factor (SPF) of a composition, especially a cosmetic composition, comprising at least one organic UV radiation screening agent present in an encapsulated form. Organic UV radiation screening agents in encapsulated form
Organic encapsulated screening agents according to the invention, and also the preparation thereof, are for example described in the application WO2004/105712.
A composition according to the invention preferably comprises, as organic anti-UV screening agent present in an encapsulated form, organic UVA screening agents and/or organic UVB screening agents.
Numerous organic UVA and/or UVB screening agents are known to those skilled in the art and may be used in an encapsulated form in the context of the present invention.
An organic UVA screening agent suitable for the invention may in particular be chosen from water-soluble dibenzoylmethane derivatives, water-soluble camphor derivatives and mixtures thereof in any proportions. As water-soluble dibenzoylmethane derivatives, mention may for example be made of 2-methyldibenzoylmethane, 4-methyldibenzoylmethane,
4-isopropyldibenzoylmethane, 4-tert-butyldibenzoylmethane, 2,4-dimethyldibenzoylmethane, 2,5-dimethyldibenzoylmethane, 4,4'-diisopropyldibenzoylmethane, 4,4'-dimethyldibenzoylmethane, butyl methoxydibenzoylmethane, 2-methyl-5-isopropyl-4'-methoxydibenzoyl-methane, 2-methyl-5-tert-butyl-4'-methoxydibenzoylmethane,
2,4-dimethyl-4'-methoxydibenzoylmethane and 2,6-dimethyl-4-tert-butyl-4'-methoxydibenzoylmethane.
More particularly, the organic UVA screening agent may be chosen from butyl methoxydibenzoylmethane, terephthalylidene dicamphor sulfonic acid, and mixtures thereof in any proportions.
According to a preferred embodiment, the organic UVA screening agent used according to the invention is butyl methoxydibenzoylmethane.
An organic UVB screening agent suitable for the invention may in particular be chosen from salicylic derivatives, cinnamates, β,β'-diphenylacrylate derivatives, triazine derivatives, and mixtures thereof in any proportions.
More particularly, the organic UVB screening agent may be chosen from ethylhexyl salicylate, ethylhexyl methoxycinnamate, octocrylene, ethylhexyl triazone, and mixtures thereof in any proportions.
According to a preferred embodiment, the organic UVA screening agent used in an encapsulated form according to the invention is octocrylene. According to one embodiment, a composition according to the invention comprises at least one organic UVA screening agent in an encapsulated form and does not contain any organic UVB screening agents in encapsulated form, in particular does not contain organic UVB screening agents, more particularly does not contain UVB screening agents.
According to another embodiment, a composition according to the invention comprises only one or more UVB screening agent(s) in an encapsulated form and does not contain any organic UVA screening agents in encapsulated form, in particular does not contain organic UVA screening agents, more particularly does not contain UVA screening agents.
According to a preferred embodiment, a composition according to the invention comprises, as organic anti-UV screening agent present in an encapsulated form, at least one organic UVA screening agent and at least one organic UVB screening agent. In this situation, the organic UVA screening agent and the organic UVB screening agent are encapsulated in accordance with the present invention.
The organic UVA and/or UVB screening agents used in the compositions of the invention are to more than 80%, in particular to more than 85%, especially to more than 90%, more particularly to more than 95%, and preferentially to 100%, in an encapsulated form according to the invention.
According to this embodiment, the organic UVA screening agent and the organic UVB screening agent are present in a composition according to the invention within the same capsules or within separate capsules. The organic UVA screening agent and the organic UVB screening agent according to the invention are preferably present in a composition of the invention within the same capsules, that is to say that the capsules of the composition comprise both at least one organic UVA screening agent and at least one organic UVB screening agent. According to a particular embodiment, a composition according to the invention comprises at least one organic UVA screening agent chosen from water-soluble dibenzoylmethane derivatives, water-soluble camphor derivatives and mixtures thereof in any proportions and at least one organic UVB screening agent chosen from salicylic derivatives, cinnamates, β,β'-diphenylacrylate derivatives, triazine derivatives, and mixtures thereof in any proportions, these screening agents being encapsulated, preferably within the same capsules.
According to this embodiment, a composition according to the invention preferably comprises at least one organic UVA screening agent chosen from butyl methoxydibenzoylmethane, terephthalylidene dicamphor sulfonic acid, and mixtures thereof in any proportions, in particular butyl methoxydibenzoylmethane, and at least one organic UVB screening agent chosen from ethylhexyl salicylate, ethylhexyl methoxycinnamate, octocrylene, ethylhexyl triazone, and mixtures thereof in any proportions, in particular octocrylene, these screening agents being encapsulated, preferably within the same capsules.
According to a particularly preferred embodiment, a composition according to the invention comprises at least butyl methoxydibenzoylmethane and octocrylene, these screening agents being encapsulates, preferably within the same capsules.
It may in particular be the commercial product sold under the name Eusolex® UV-Pearls® OB-S by the company Merck.
The content of organic anti-UV screening agent(s) present in an encapsulated form in a composition according to the invention may be between 0.5% and 50% by weight, preferably between 1% and 40% by weight, more particularly between 5% and 30% by weight relative to the total weight of the composition.
In particular, the content of organic anti-UV screening agent(s) present in an encapsulated form in a composition according to the invention may be between 0.5% and 25% by weight, preferably between 1% and 20% by weight, more particularly between 5% and 15% by weight relative to the total weight of the composition.
In particular, the content of organic anti-UVA screening agent(s) present in an encapsulated form in a composition according to the invention may be between 0.1% and 15% by weight, preferably between 0.5% and 10% by weight, more particularly between 1% and 5% by weight relative to the total weight of the composition.
Also, the content of organic anti-UVB screening agent(s) present in an encapsulated form in a composition according to the invention may be between 1% and 25% by weight, preferably between 2% and 20% by weight, more particularly between 5% and 15% by weight relative to the total weight of the composition. Capsules encapsulating the organic screening agents suitable for the invention may have walls produced from organic or inorganic polymers. For example, patent US6242099B1 describes the preparation of capsules suitable for the invention from chitin, chitin derivatives or polyhydroxylated polyamines.
According to one embodiment, the capsules used according to the invention are prepared by means of a sol-gel process, as described in WO00/09652, WO00/72806 and WO00/71084. In particular, according to this embodiment, the capsules may be formed of silica gel. The preparation of corresponding capsules is known to those skilled in the art, such as, for example, in the documents indicated above.
According to another embodiment, the wall of the capsules used according to the invention is mainly composed of organ opolysiloxane. Methods making it possible to produce such capsules are described, for example, in US6337089 and in US6252313.
The organopolysiloxane is preferably synthesized by polycondensation of one or more compounds represented by the general formula (I):
in which m represents an integer between 1 and 4 and n represents an integer between 0 and 3, with the proviso that m+n<4; R represents an organic group in which a carbon atom is directly bonded to the silicon atom, and when n is greater than 1, each of the groups R may be identical or different; and Y represents at least one group chosen from the group constituted by an alkoxy group, a hydrogen and a siloxy group, and when (4-m- n) is greater than 1, each of the groups Y may be different or identical.
The formation of the capsule comprising the organic UV screening agent according to the invention mainly consists of the preparation of a mixture comprising said UV screening agent in combination with a precursor element of the capsule wall, followed by the formation of this wall by condensation of the precursor, as is described for example in application WO2004/105712.
In particular, according to one particular embodiment, the condensation carried out during the preparation of the anti-UV screening agents in an encapsulated form consists of a polycondensation taking place in a sol-gel process.
According to one embodiment, the precursor element used in the formation of the capsules according to the invention is a polysiloxane prepolymer.
A composition according to the invention may also comprise, in addition to the organic anti-UV screening agents encapsulated according to the invention, at least one inorganic anti-UVA screening agent and/or at least one inorganic anti-UVB screening agent. Dispersions of particles according to the invention
A composition according to the invention comprises at least one dispersion of particles as defined below.
Thus, a dispersion of particles according to the invention is a dispersion, in a non-aqueous medium containing at least one hydrocarbon-based oil, of particles of at least one polymer, the particles being surface- stabilized by a stabilizer;
the polymer of the particles:
(i) being a C1-C4 alkyl (meth)acrylate polymer or copolymer;
(ii) being present in the composition in a content ranging from 1% to 10% by weight relative to the total weight of the composition; and
(iii) having a glass transition temperature of less than 150°C;
the stabilizer being an isobornyl (meth)acrylate polymer chosen from isobornyl (me h)acrylate homopolymer and statistical copolymers of isobomyl (me h)acrylate and of C1-C4 alkyl (meth)acrylate present in an isobornyl (meth)acrylate/Ci-C 4 alkyl (me h)acrylate weight ratio of greater than 4.
Preferably, the polymer of the particles has a glass transition temperature of between 8°C and 150°C, preferably between 8°C and 120°C, more preferentially between 8°C and 110°C.
According to a particular embodiment, the polymer of the particles has a glass transition temperature of between 8°C and 110°C, preferably between 8°C and 50°C, more preferentially between 8°C and 30°C.
The dispersions according to the invention are thus constituted of surface- stabilized particles, which are generally spherical, of at least one polymer in a non-aqueous medium.
The polymer of the particles is a C1-C4 alkyl (meth)acrylate polymer or copolymer;
The C 1 -C 4 alkyl (meth)acrylate monomers may be chosen from methyl (me h)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (me h)acrylate, n- butyl (me h)acrylate, and tert-butyl (me h)acrylate.
Preferentially, the polymer of the particles is a methyl acrylate and/or ethyl acrylate polymer. The polymer of the particles may also comprise an ethylenically unsaturated acid monomer or the anhydride thereof, chosen especially from ethylenically unsaturated acid monomers comprising at least one carboxylic, phosphoric or sulfonic acid function, such as crotonic acid, itaconic acid, fumaric acid, maleic acid, maleic anhydride, styrenesulfonic acid, vinylbenzoic acid, vinylphosphoric acid, acrylic acid, methacrylic acid, acrylamidopropanesulfonic acid or acrylamidoglycolic acid, and salts thereof.
The salts may be chosen from salts of alkali metals, for example sodium or potassium; salts of alkaline-earth metals, for example calcium, magnesium or strontium; metal salts, for example zinc, aluminium, manganese or copper; ammonium salts of formula NH 4 + ; quaternary ammonium salts; salts of organic amines, such as, for example, salts of methylamine, dimethylamine, trimethylamine, triethylamine, ethylamine, 2- hydroxyethylamine, bis(2-hydroxyethyl)amine or tris(2-hydroxyethyl)amine; lysine or arginine salts.
The ethylenically unsaturated acid monomer is preferably chosen from
(meth)acrylic acid, maleic acid and maleic anhydride.
According to one embodiment, the ethylenically unsaturated acid monomer included in the polymer of the particles is acrylic acid.
The polymer of the particles may thus comprise or consist essentially of, from 80% to 100% by weight of Ci-C 4 alkyl (meth)acrylate and from 0 to 20% by weight of ethylenically unsaturated acid monomer, relative to the total weight of the polymer.
According to a first embodiment of the invention, the polymer consists essentially of a polymer of one or more Ci-C 4 alkyl (meth)acrylate monomers.
According to a second embodiment of the invention, the polymer is essentially constituted of a copolymer of Ci-C 4 alkyl (meth)acrylate and of (meth)acrylic acid or maleic anhydride.
The polymer of the particles of the invention may in particular be chosen from: methyl acrylate homopolymers;
ethyl acrylate homopolymers;
methyl acrylate/ethyl acrylate copolymers; methyl acrylate/ethyl acryl ate/acrylic acid copolymers;
methyl acrylate/ethyl acrylate/maleic anhydride copolymers;
methyl acrylate/acrylic acid copolymers;
ethyl acrylate/acrylic acid copolymers;
methyl acrylate/maleic anhydride copolymers;
ethyl acrylate/maleic anhydride copolymers; and
the methyl methacrylate homopolymer.
More particularly, a polymer of the particles of the invention may be chosen from C 1 -C4 alkyl (meth)acrylate polymers or copolymers of C1-C4 alkyl (meth)acrylate and (me h)acrylic acid or maleic anhydride, preferably from copolymers of C1-C4 alkyl (mefh)acrylate and (meth)acrylic acid or maleic anhydride.
According to a preferred embodiment, the polymer of the particles is a polyacrylate of methyl-co-ethyl acrylate-acrylic acid.
According to another preferred embodiment, the polymer of the particles is chosen from the group constituted by a methyl acrylate, a methyl methacrylate, and a methyl acrylate/ethyl acrylate copolymer.
Advantageously, the polymer of the particles is a non-crosslinked polymer. The polymer of the particles of the dispersion preferably has a number-average molecular weight ranging from 2000 to 10 000 000 and preferably ranging from 150 000 to 500 000.
The polymer of the particles may be present in the dispersion in a content ranging from 21% to 58.5% by weight and preferably ranging from 36% to 42% by weight, relative to the total weight of the dispersion.
In particular, the polymer of the particles may be present in the dispersion in a content ranging from 0.5% to 5% by weight, relative to the total weight of the composition.
The stabilizer is an isobornyl (meth)acrylate polymer or copolymer chosen from isobornyl (me h)acrylate homopolymer and statistical copolymers of isobornyl (me h)acrylate and C1-C4 alkyl (meth)acrylate present in an isobornyl (meth)acrylate/Ci-C4 alkyl (me th) acrylate weight ratio of greater than 4. Advantageously, the said weight ratio ranges from 4.5 to 19. Advantageously, the stabilizer is chosen from:
- isobomyl acrylate homopolymers;
- statistical copolymers of isobomyl acrylate/methyl acrylate;
- statistical copolymers of isobomyl acrylate/methyl acrylate/ethyl acrylate; and
- statistical copolymers of isobomyl methacrylate/methyl acrylate;
- statistical copolymers of isobomyl acrylate and methyl methacrylate; in the weight ratio described previously.
Preferably, the stabilizer is chosen from statistical copolymers of isobomyl acrylate/methyl acrylate; statistical copolymers of isobomyl acrylate/ methyl acrylate/ ethyl acrylate; and statistical copolymers of isobomyl acrylate and methyl methacrylate.
The stabilizing polymer preferably has a number- average molecular weight ranging from 10 000 to 400 000 and preferably ranging from 20 000 to 200 000.
The stabilizer is in contact with the surface of the polymer particles and thus makes it possible to stabilize these particles at the surface in order to keep these particles in dispersion in the non-aqueous medium of the dispersion.
Advantageously, the combination of stabilizer + polymer of the particles present in the dispersion comprises from 10% to 50% by weight of polymerized isobomyl (meth)acrylate and from 50% to 90% by weight of polymerized C1-C4 alkyl (meth)acrylate, relative to the total weight of the combination of stabilizer + polymer of the particles.
Preferentially, the combination of stabilizer + polymer of the particles present in the dispersion comprises from 15% to 30% by weight of polymerized isobomyl (meth)acrylate and from 70% to 85% by weight of polymerized C1-C4 alkyl (meth)acrylate, relative to the total weight of the combination of stabilizer + polymer of the particles.
The oily medium of the polymer dispersion comprises a hydrocarbon-based oil. The hydrocarbon-based oil is an oil that is liquid at room temperature (25 °C). The term "hydrocarbon-based oil" means an oil formed essentially from, or even constituted of, carbon and hydrogen atoms, and optionally oxygen and nitrogen atoms, and not containing any silicon or fluorine atoms. It may contain alcohol, ester, ether, carboxylic acid, amine and/or amide groups.
The hydrocarbon-based oil may be chosen from:
- hydrocarbon-based oils having from 8 to 14 carbon atoms, and especially: (i) C8-C14 branched alkanes such as C 8 -Ci 4 isoalkanes of petroleum origin (also referred to as isoparaffins) such as isododecane (also referred to as 2,2,4,4,6- pentamethylheptane), isodecane and, for example, the oils sold under the trade names Isopar or Permethyl, and
(ii) linear alkanes, for instance n-dodecane (C 12 ) and n-tetradecane (C 14 ) sold by Sasol under the respective references Parafol 12-97 and Parafol 14-97, and also mixtures thereof, the undecane-tridecane mixture, the mixtures of n-undecane (Cii) and of n-tridecane (C 13 ) obtained in Examples 1 and 2 of application WO 2008/155 059 from the company Cognis, and mixtures thereof;
- short-chain esters (having from 3 to 8 carbon atoms in total) such as ethyl acetate, methyl acetate, propyl acetate or n-butyl acetate;
- hydrocarbon-based oils of plant origin such as triglycerides constituted by fatty acid esters of glycerol, the fatty acids of which may have chain lengths varying from C 4 to C 2 4, these chains possibly being linear or branched, and saturated or unsaturated; these oils are in particular heptanoic or octanoic acid triglycerides, or alternatively wheatgerm oil, sunflower oil, grapeseed oil, sesame seed oil, corn oil, apricot oil, castor oil, shea oil, avocado oil, olive oil, soybean oil, sweet almond oil, palm oil, rapeseed oil, cottonseed oil, hazelnut oil, macadamia oil, jojoba oil, alfalfa oil, poppy oil, pumpkin oil, marrow oil, blackcurrant oil, evening primrose oil, millet oil, barley oil, quinoa oil, rye oil, safflower oil, candlenut oil, passion-flower oil and musk rose oil; shea butter; or else caprylic/capric acid triglycerides, such as those sold by the company Stearineries Dubois or those sold under the names Miglyol 810®, 812® and 818® by the company Dynamit Nobel;
- synthetic ethers having from 10 to 40 carbon atoms;
- linear or branched hydrocarbons of mineral or synthetic origin, such as petroleum jelly, polydecenes, hydrogenated polyisobutene such as Parleam®, squalane and liquid paraffins, and mixtures thereof; - synthetic esters such as oils of formula R1COOR2 in which Ri represents a linear or branched fatty acid residue comprising from 1 to 40 carbon atoms and R 2 represents an especially branched hydrocarbon-based chain containing from 1 to 40 carbon atoms, with the proviso that Ri + R 2 > 10, for instance purcellin oil (cetostearyl octanoate), isopropyl myristate, isopropyl palmitate, C 12 to C15 alkyl benzoates, hexyl laurate, diisopropyl adipate, isononyl isononanoate, 2-ethylhexyl palmitate, isostearyl isostearate, 2-hexyldecyl laurate, 2-octyldecyl palmitate, 2-octyldodecyl myristate, alkyl or polyalkyl heptanoates, octanoates, decanoates or ricinoleates such as propylene glycol dioctanoate; hydroxylated esters such as isostearyl lactate, diisostearyl malate and 2-octyldodecyl lactate; polyol esters and pentaerythritol esters; and
- fatty alcohols that are liquid at room temperature, with a branched and/or unsaturated carbon-based chain having from 12 to 26 carbon atoms, such as octyldodecanol, isostearyl alcohol, oleyl alcohol, 2-hexyldecanol, 2-butyloctanol and 2- undecylpentadecanol.
Advantageously, the hydrocarbon-based oil is apolar (thus formed solely from carbon and hydrogen atoms).
The hydrocarbon-based oil is preferably chosen from hydrocarbon-based oils having from 8 to 14 carbon atoms, in particular from apolar hydrocarbon-based oils having from 8 to 14 carbon atoms, and preferably the apolar oils described above.
Preferentially, the hydrocarbon-based oil is isododecane.
The polymer particles of the dispersion preferably have an average size, in particular a number- average size, ranging from 50 to 500 nm, especially ranging from 75 to 400 nm and better still ranging from 100 to 250 nm.
In general, the dispersion according to the invention may be prepared in the following manner, which is given as an example.
The polymerization may be performed in dispersion, i.e. by precipitation of the polymer during formation, with protection of the formed particles with a stabilizer.
In a first step, the stabilizing polymer is prepared by mixing the constituent monomer(s) of the stabilizing polymer, with a free-radical initiator, in a solvent known as the synthesis solvent, and by polymerizing these monomers. In a second step, the constituent monomer(s) of the polymer of the particles are added to the stabilizing polymer formed and polymerization of these added monomers is performed in the presence of the free-radical initiator.
When the non-aqueous medium is a non-volatile hydrocarbon-based oil, the polymerization may be performed in an apolar organic solvent (synthesis solvent), followed by adding the non-volatile hydrocarbon-based oil (which should be miscible with said synthesis solvent) and selectively distilling off the synthesis solvent.
A synthesis solvent which is such that the monomers of the stabilizing polymer and the radical initiator are soluble therein, and the polymer particles obtained are insoluble therein, so that they precipitate therein during their formation, is thus chosen.
In particular, the synthesis solvent may be chosen from alkanes such as heptane or cyclohexane.
When the non-aqueous medium is a volatile hydrocarbon-based oil, the polymerization may be performed directly in said oil, which thus also acts as synthesis solvent. The monomers should also be soluble therein, as should the free-radical initiator, and the polymer of the particles which is obtained should be insoluble therein.
The monomers are preferably present in the synthesis solvent, before polymerization, in a proportion of 5%-20 by weight. The total amount of the monomers may be present in the solvent before the start of the reaction, or part of the monomers may be added gradually as the polymerization reaction proceeds.
The radical initiator may especially be azobisisobutyronitrile or tert-butyl peroxy-2-ethylhexanoate.
The polymerization may be performed at a temperature ranging from 70 to
110°C.
The polymer particles are surface- stabilized, when they are formed during the polymerization, by means of the stabilizer.
The stabilization may be performed by any known means, and in particular by direct addition of the stabilizer, during the polymerization.
The stabilizer is preferably also present in the mixture before polymerization of the monomers of the polymer of the particles. However, it is also possible to add it continuously, especially when the monomers of the polymer of the particles are also added continuously. From 10% to 30% by weight and preferably from 15% to 25% by weight of stabilizer may be used relative to the total weight of monomers used (stabilizer + polymer of the particles).
The dispersion of polymer particles advantageously comprises from 30% to 65% by weight and preferably from 40% to 60% by weight of solids, relative to the total weight of the dispersion.
Advantageously, the oily dispersion may comprise a plasticizer chosen from tri-n-butyl citrate, tripropylene glycol monomethyl ether (INCI name: PPG-3 methyl ether) and trimethyl pentaphenyl trisiloxane (sold under the name Dow Corning PH-1555 HRI Cosmetic Fluid by the company Dow Coming). These plasticizers make it possible to improve the mechanical strength of the polymer film.
The plasticizer may be present in the oily dispersion in a content ranging from 5% to 50% by weight, relative to the total weight of the polymer of the particles.
The composition according to the invention may comprise the polymer particles and stabilizer of the dispersion in a content ranging from 0.2% to 20% by weight and preferably ranging from 0.5% to 10% by weight relative to the total weight of the composition.
Composition according to the invention
The compositions, especially the cosmetic compositions, according to the invention comprise a physiologically acceptable medium.
Within the meaning of the present invention, the term "physiologically acceptable medium" is intended to denote a medium that is suitable for the topical administration of a composition.
A physiologically acceptable medium generally has no unpleasant odour or appearance, and is perfectly compatible with topical administration. In the present case, where the composition is intended for topical administration, i.e. by application at the surface of the keratin material under consideration, such a medium is considered in particular to be physiologically acceptable when it does not cause stinging, tightness or redness that is unacceptable to the user.
In particular, the composition is suited to topical application, that is to say application on the surface of the skin, the scalp and/or the mucous membrane under consideration. Thus, the physiologically acceptable medium is preferentially a cosmetically or dermatologically acceptable medium, that is to say a medium that has no unpleasant odour, colour or appearance, and that does not cause the user any unacceptable stinging, tightness or redness.
The composition may then comprise any constituent usually used in the envisaged application.
The composition according to the invention may also comprise at least one additional element chosen from water, solvents, pigments, fragrances, preserving agents, fillers, colorants, inorganic UV screening agents, oils of mineral, animal and/or vegetable origin, waxes, surfactants, moisturizers, vitamins, ceramides, antioxidants, free-radical scavengers, polymers and thickeners.
Needless to say, those skilled in the art will take care to select this or these optional additional compound(s), and/or the amount thereof, such that the advantageous properties of the compounds according to the invention are not, or are not substantially, adversely affected by the envisaged addition.
According to one preferred embodiment, a composition according to the invention comprises a water content of between 20% and 75% by weight, preferably between 30% and 70% by weight, and more particularly between 40% and 60% by weight of water relative to the total weight of the composition.
Preferably, a composition according to the invention is in the form of an oil-in- water or water-in-oil emulsion, and is preferably an oil-in-water emulsion.
This composition may be more or less fluid and may have the appearance of a white or coloured cream, an ointment, a milk, a lotion, a serum, a paste or a foam. It may optionally be applied to the skin in aerosol form. It may also be in solid form, for example in the form of a stick.
The compositions according to the invention may be in the form of products for caring for the skin or semi-mucous membranes, such as a protective or cosmetic care composition for the face, for the lips, for the hands, for the feet, for the anatomical folds or for the body (for example, day creams, night cream, day serum, night serum, makeup- removing cream, makeup base, antisun composition, protective or care body milk, aftersun milk, skincare or scalp-care lotion, gel or foam, serum, mask, or aftershave composition). In one advantageous aspect of the invention, the compositions used may also comprise at least one desquamating agent, and/or at least one calmative, and/or at least one mineral photoprotective agent and/or a depigmenting agent.
Such compositions as defined above may especially be employed for a cosmetic use, and in a cosmetic process, according to the invention, as described above.
Use of a composition according to the invention
As specified above, and as demonstrated in the examples of the present text, a composition in accordance with the invention advantageously makes it possible to increase the Sun Protection Factor (SPF) in the presence of UV screening agents in encapsulated form.
Thus, as indicated above, the present invention targets the cosmetic use of a composition as defined above for preventing the darkening of the skin and/or improving the colour and/or uniformity of the complexion, comprising the application, to the surface of the keratin material, of at least one composition as defined above.
A composition according to the invention also makes it possible to prevent the appearance on the skin, in particular on the face, the neckline, the arms, the hands and/or the shoulders, of darker and/or more coloured marks which give the skin non-uniform colour.
In addition, the present invention targets the cosmetic use of a composition as defined above, for preventing premature ageing of the skin, especially on the face, the neckline, the arms, the hands and/or the shoulders, in particular the signs of skin ageing of actinic origin, such as photoageing.
The present invention also targets the cosmetic use of a composition as defined above to prevent a loss of firmness and/or elasticity and/or tonicity and/or suppleness of the skin, the formation of wrinkles and fine lines, a dull complexion, and/or a wizened appearance of the skin.
More particularly, the present invention targets the use of a dispersion of particles of at least one polymer as defined above, in order to increase the Sun Protection Factor of a composition, especially a cosmetic composition, comprising at least one organic UV radiation screening agent present in an encapsulated form. Advantageously, the composition according to the invention is a makeup composition, in particular a lip makeup, mascara, eyeliner, eyeshadow or foundation composition.
In the description and in the examples that follow, unless otherwise mentioned, the percentages are weight percentages and the ranges of values given in the form "between... and..." include the stated lower and upper limits.
Throughout the description, including the claims, the term "comprising a" should be understood as being synonymous with "comprising at least one", unless otherwise specified.
The examples that follow are given as nonlimiting illustrations of the invention.
EXAMPLES
Example 1 - Preparation of an emulsion according to the invention:
The aqueous and oily phases are prepared by mixing, with magnetic stirring at 80°C, until the starting materials of the oily phase (behenyl alcohol (and) glyceryl stearate (and) disodium ethylene dicoamide PEG- 15 disulfate (and) glyceryl stearate citrate, cetyl alcohol, caprylyl alcohol) were completely dissolved. The solutions obtained are macroscopically homogeneous.
The emulsion is prepared by slow introduction of the oily phase into the aqueous phase with stirring by means of a Moritz-type homogenizer, at a stirring speed of 4000 rpm for 15 minutes at 80°C and at atmospheric pressure. The emulsion obtained is cooled, with stirring, to 40°C, then the oily phase is added thereto with gentle stirring.
The emulsion obtained is cooled to 40°C to introduce the gelling agents phase then to room temperature to add the encapsulated screening agents then the alcohol.
The emulsion is characterized by drops of between 1 mm and 10 mm in size.
Example 2: evaluation of the screening effectiveness
Different compositions, in accordance or not in accordance with the invention and described in more detail below, were prepared on the basis of the protocol described in example 1. The screening effectiveness (SPF) of each of these compositions was evaluated in vitro according to the protocol defined below.
The Sun Protection Factor (SPF) is determined in vitro according to the method described by B. L. Diffey and J. Robson in J. Soc. Cosmet. Chem. 40, 127-133 (1989).
The measurements were made by means of a UV-1000S spectrophotometer from the company Labsphere.
Each composition is applied to a rough plate of poly(methyl methacrylate) (PMMA), in the form of a uniform and even deposit in a proportion of 1 mg/cm 2 .
Example 3: Evaluation of the stability of the compositions
Similarly, the stability of the compositions described below was also evaluated according to the protocol described below. The stability was thus evaluated by microscopic observations of the appearance of the compositions, and more particularly the state of the dispersion of particles. A composition is judged to be stable when its microscopic appearence at TO and its viscosity are stable and for 1 month at room temperature.
Example 4: Comparisons between compositions of the invention and outside the invention
The values are indicated as percentage by weight, relative to the total weight of the composition.
Composition 1 Composition 2 Composition 3
Commercial
INCI (EU) (According to (According to (Outside the references
the invention) the invention) invention)
Potassium hydroxide 0.21 % 0.21% 0.21 %
Disodium EDTA 0.05% 0.05% 0.05%
Sodium hyaluronate Cristalhyal LO 0.02% 0.02% 0.02%
Menthoxypropanediol Coolact 10 0.25% 0.25% 0.25%
Preserving agent Sepicide LD 0.5% 0.5% 0.5%
Cetyl alcohol Lanette 16 0.5% 0.5% 0.5%
Diisopropyl sebacate Dub dis 7% 7% 7%
Isopropyl lauroyl sarcosinate Eldew SL-205 5% 5% 5%
Water (and) octocrylene (and) Eusolex® UV- butyl methoxydibenzoylmethane Pearls® OB-S 30% 30% 30%
(and) PVP from MERCK
Acrylates/Cio-30 alkyl acrylate Pemulen TR-2
0.25% 0.25% 0.25% crosspolymer Polymer
Rheopearl KL2
Dextrin palmitate 0.25% 0.25% 0.25%
OR
Ammonium Hostacerin
0.18% 0.18% 0.18% polyacryloyldimethyl taurate AMPS
Methyl methacrylate Tech-polymer
1.5% 1.5% 1.5% crosspolymer MBP-8
Compositions 1 and 2 are in accordance with the invention in that they comprise an organic UV radiation screening agent present in an encapsulated form (Eusolex® UV-Pearls® OB-S from MERCK) and an oily dispersion as defined above in accordance with the invention, the polymers of which have a glass transition temperature of 23°C (composition 1) or of between 8 and 10°C (composition 2).
The content of C1-C4 alkyl (meth) acrylate polymers + stabilizer of the oily dispersion according to the invention is 4% by weight relative to the total weight of the composition for compositions 1 and 2. A composition outside the invention was also produced, namely composition 3.
The latter only differs from compositions 1 and 2 according to the invention in that it does not contain an oily dispersion of polymers according to the invention.
It is observed that the measurements of SPF carried out in vitro on 5 plates are significantly higher for the compositions in accordance with the invention compared to composition 3 outside the invention.
The presence of an oily dispersion of polymers according to the invention consequently advantageously makes it possible to improve the SPF of a composition comprising organic UV radiation screening agents in an encapsulated form.
Example 5: Comparisons between compositions of the invention and outside the invention
The values are indicated as percentage by weight, relative to the total weight of the composition.
Compoun Compoun Compoun Compoun Compoun d 4 d 5 d 6 d 7 d 8
INCI (EU) Com. ref. (Accordin (Accordin (Accordin (Outside (Outside g to the g to the g to the the the invention) invention) invention) invention) invention)
Potassium hydroxide 0.21 % 0.21 % 0.21 % 0.21 % 0.21 %
Disodium EDTA 0.05% 0.05% 0.05% 0.05% 0.05%
Cristalhyal
Sodium hyaluronate 0.02% 0.02% 0.02% 0.02% 0.02%
LO
Menthoxypropanediol Coolact 10 0.25% 0.25% 0.25% 0.25% 0.25%
Preserving agent 0.5% 0.5% 0.5% 0.5% 0.5%
Cetyl alcohol Lanette 16 0.5% 0.5% 0.5% 0.5% 0.5%
Diisopropyl sebacate Dub dis 7% 7% 7% 7% 7% Isopropyl lauroyl Eldew
5% 5% 5% 5% 5% sarcosinate SL-205
Water (and) Eusolex®
octocrylene (and) UV- butyl Pearls® 30% 30% 30% 30% 30% methoxydibenzoylmet OB-S from
hane (and) PVP MERCK
Pemulen
Acrylates/Cio-30 alkyl
TR-2 0.25% 0.25% 0.25% 0.25% 0.25% acrylate crosspolymer
Polymer
Rheopearl
Dextrin palmitate 0.25% 0.25% 0.25% 0.25% 0.25%
KL2 OR
Ammonium
Hostacerin
polyacryloyl-dimethyl 0. 18%. 0.18% 0.18% 0.18% 0. 18%
AMPS
taurate
Tech-
Methyl methacrylate
polymer 1.5% 1.5% 1.5% 1.5% 1.5% crosspolymer
MBP-8
Styrene/acrylates
Sunsphere 0 0 0 0 2% copolymers
(methyl acrylate)-co- (isobornyl acrylate)
(80.7/19.3) copolymer
dissolved in
isododecane
3.87%
(Tg 23°C)
0 0 (2% AM in 0 0 Stabilizins arm:
polymers)
Poly(isobornyl
aery late -co-methyl
acrvlate and Core of
the particles:
Poly(methyl acrylate)
(methyl methacrylate) - co-(isobomyl acrylate)
copolymer (21/79)
dispersed in
isododecane (Tg
5.13% (2%
104°C): Stabilizins
AM in 0 0 0 0 arm: Poly(isobornyl
polymers)
acrylate -co-methyl
methacrylate) and
Core of the particles:
Poly(methyl
methacrylate)
1 month at RT
Compositions 4, 5 and 6 are in accordance with the invention in that they comprise an organic UV radiation screening agent present in an encapsulated form (Eusolex® UV-Pearls® OB-S from MERCK) and an oily dispersion as defined above in accordance with the invention, the polymers of which have a glass transition temperature of 140°C (composition 4), of between 8 and 10°C (composition 5) or of 23°C (composition 6).
The content of C1-C4 alkyl (meth)acrylate polymers + stabilizer of the oily dispersion according to the invention is 2% by weight relative to the total weight of the composition for compositions 4, 5 and 6.
Two compositions outside the invention were also produced, namely compositions 7 and 8.
Composition 7 outside the invention differs from compositions 4 to 6 according to the invention in that it does not contain an oily dispersion of polymers according to the invention.
For its part, composition 8 outside the invention differs from compositions 4 to 6 according to the invention in that it comprises a styrene/acrylates copolymer instead of an oily dispersion of polymers according to the invention.
It is observed that the measurements of SPF carried out in vitro are higher for the compositions in accordance with the invention compared to compositions 7 and 8 outside the invention.
Thus, it is demonstrated again that the presence of an oily dispersion of polymers according to the invention advantageously makes it possible to improve the SPF of a composition comprising organic UV radiation screening agents in an encapsulated form.