Composition comprising a dibenzoylmethane screening agent and a merocyanine dicyano or cyanoacetate derivative; method for the photostabilization of the dibenzoylmethane screening agent

1. Composition comprising, in a cosmetically acceptable vehicle, at least one UV screening system, characterized in that it comprises:

(1) at least one dibenzoylmethane derivative and

(2) an amount effective for photostabilizing the composition of at least one merocyanine dicyano or cyanoacetate derivative chosen from the group consisting of:

(i) those corresponding to the following general formula (I):

in which:

A is the —C≡N or —(C═O)OR 3 group,

R 1 and R 2 , which are identical or different, denote a linear or branched C 1 -C 3 alkyl radical, the hydroxyethyl group or a C 5 -C 6 cycloalkyl,

R 3 denotes a linear or branched C 1 -C 8 alkyl radical,

n is 1 or 2;

with the proviso that, when n=2, R 1 , R 2 or R 3 is a C 2 -C 16 alkyl diradical or else R 1 and R 2 form, with 2 nitrogen atoms, a cyclic divalent —(CH 2 ) m — radical with m being an integer ranging from 3 to 7;

(ii) the compound (a):

(iii) the compound (b):

(iv) the compound (c):

(v) the compound (l):

(vi) the compound (p):

(vii) the compound (v):

(viii) the compound (w):

(ix) the compound (x):

(x) the compound (aa)

(xi) the compound (bb)

and their E,E-, E,Z- or Z,Z-geometrical isomeric forms.

2. Composition according to claim 1 , where the compound or compounds of formula (I) are chosen from those of the following formulae and their E,E-, E,Z- or Z,Z-isomers:

3. Composition according to claim 1 , where the merocyanine dicyano or cyanoacetate derivative or derivatives are chosen from the following compounds or their isomeric forms:

4. Composition according to claim 1 , where the dibenzoylmethane derivative is 4-(tert-butyl)-4′-methoxydibenzoylmethane or Butyl Methoxy Dibenzoylmethane or avobenzone in the following formula:

5. Composition according to claim 1 , wherein it additionally comprises other additional organic or inorganic screening agents which are active in the UV-A and/or UV-B regions and which are water-soluble or fat-soluble or else insoluble in the cosmetic solvents commonly used.

6. Composition according to claim 5 , where the additional organic screening agents are chosen from anthranilics; cinnamic derivatives; salicylic derivatives, benzylidenecamphor derivatives; benzophenone derivatives; β,β-diphenylacrylate derivatives; triazine derivatives; phenylbenzotriazole derivatives; benzalmalonate derivatives; phenylbenzimidazole derivatives; imidazolines; bis-benzazolyl derivatives; p-aminobenzoic acid (PABA) derivatives; methylenebis(hydroxyphenylbenzotriazole) derivatives; benzoxazole derivatives; screening polymers and screening silicones; dimers derived from α-alkylstyrene; 4,4-diarylbutadienes; merocyanine derivatives other than those of formula (I), (a), (b), (c), (l), (p), (v), (w), (x), (aa) and (bb); and their mixtures.

7. Composition according to claim 5 , wherein the organic UV screening agent or agents are chosen from the following compounds:

Ethylhexyl Methoxycinnamate,

Homosalate,

Ethylhexyl Salicylate,

Octocrylene,

Phenylbenzimidazole Sulfonic Acid,

Benzophenone-3,

Benzophenone-4,

Benzophenone-5,

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

1,1′-(1,4-Piperazinediyl)bis[1-[2-[4-(diethylamino)-2-hydroxybenzoyl]phenyl]-methanone]

4-Methylbenzylidene Camphor,

Terephthalylidene Dicamphor Sulfonic Acid,

Disodium Phenyl Dibenzimidazole Tetrasulfonate,

Ethylhexyl Triazone,

Bis-Ethylhexyloxyphenol Methoxyphenyl Triazine,

Diethylhexyl Butamido Triazone,

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

2,4,6-Tris(dineopentyl 4′-aminobenzalmalonate)-s-triazine,

2,4,6-Tris-(diisobutyl 4′-aminobenzalmalonate)-s-triazine,

2,4-Bis(dineopentyl 4′-aminobenzalmalonate)-6-(n-butyl 4′-aminobenzoate)-s-triazine,

2,4-Bis(n-butyl 4′-aminobenzoate)-6-[(3-{1,3,3,3-tetramethyl-1-[(trimethylsilyl)-oxy]disiloxanyl}propyl)amino]-s-triazine,

Methylene Bis-Benzotriazolyl Tetramethylbutylphenol,

Drometrizole Trisiloxane,

Polysilicone-15,

Dineopentyl 4′-methoxybenzalmalonate,

1,1-Dicarboxy(2,2′-dimethylpropyl)-4,4-diphenylbutadiene,

2,4-Bis[5-1(dimethylpropyl)benzoxazol-2-yl-(4-phenyl)imino]-6-(2-ethylhexyl)imino-1,3,5-triazine,

and their mixtures.

8. Composition according to claim 5 , wherein the additional inorganic screening agents are coated or uncoated metal oxide pigments.

9. Composition according to claim 1 , wherein it is provided in the form of an oil-in-water or water-in-oil emulsion.

10. Method for improving the chemical stability with regard to UV radiation of at least one dibenzoylmethane derivative as defined in any one of the preceding claims, characterized in that the said dibenzoylmethane derivative is combined with an effective amount of at least one merocyanine dicyano or cyanoacetate derivative or one of its E,E-, E,Z- or Z,Z-isomeric forms as defined in claim 1 .

11. Composition according to claim 2 , where the merocyanine dicyano or cyanoacetate derivative or derivatives are chosen from the following compounds or their isomeric forms:

12. Composition according to claim 2 , where the dibenzoylmethane derivative is 4-(tert-butyl)-4′-methoxydibenzoylmethane or Butyl Methoxy Dibenzoylmethane or avobenzone in the following formula:

13. Composition according to claim 3 , where the dibenzoylmethane derivative is 4-(tert-butyl)-4′-methoxydibenzoylmethane or Butyl Methoxy Dibenzoylmethane or avobenzone in the following formula:

14. Composition according to claim 2 , wherein it additionally comprises other additional organic or inorganic screening agents which are active in the UV-A and/or UV-B regions and which are water-soluble or fat-soluble or else insoluble in the cosmetic solvents commonly used.

15. Composition according to claim 3 , wherein it additionally comprises other additional organic or inorganic screening agents which are active in the UV-A and/or UV-B regions and which are water-soluble or fat-soluble or else insoluble in the cosmetic solvents commonly used.

16. Composition according to claim 4 , wherein it additionally comprises other additional organic or inorganic screening agents which are active in the UV-A and/or UV-B regions and which are water-soluble or fat-soluble or else insoluble in the cosmetic solvents commonly used.

17. Composition according to claim 6 , wherein the organic UV screening agent or agents are chosen from the following compounds:

Ethylhexyl Methoxycinnamate,

Homosalate,

Ethylhexyl Salicylate,

Octocrylene,

Phenylbenzimidazole Sulfonic Acid,

Benzophenone-3,

Benzophenone-4,

Benzophenone-5,

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

1,1′-(1,4-Piperazinediyl)bis[1-[2-[4-(diethylamino)-2-hydroxybenzoyl]phenyl]-methanone]

4-Methylbenzylidene Camphor,

Terephthalylidene Dicamphor Sulfonic Acid,

Disodium Phenyl Dibenzimidazole Tetrasulfonate,

Ethylhexyl Triazone,

Bis-Ethylhexyloxyphenol Methoxyphenyl Triazine,

Diethylhexyl Butamido Triazone,

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

2,4,6-Tris(dineopentyl 4′-aminobenzalmalonate)-s-triazine,

2,4,6-Tris-(diisobutyl 4′-aminobenzalmalonate)-s-triazine,

2,4-Bis(dineopentyl 4′-aminobenzalmalonate)-6-(n-butyl 4′-aminobenzoate)-s-triazine,

2,4-Bis(n-butyl 4′-aminobenzoate)-6-[(3-{1,3,3,3-tetramethyl-1-[(trimethylsilyl)-oxy]disiloxanyl}propyl)amino]-s-triazine,

Methylene Bis-Benzotriazolyl Tetramethylbutylphenol,

Drometrizole Trisiloxane,

Polysilicone-15,

Dineopentyl 4′-methoxybenzalmalonate,

1,1-Dicarboxy(2,2′-dimethylpropyl)-4,4-diphenylbutadiene,

2,4-Bis[5-1(dimethylpropyl)benzoxazol-2-yl-(4-phenyl)imino]-6-(2-ethylhexyl)imino-1,3,5-triazine,

and their mixtures.

18. The composition according to claim 1 , where the at least one dibenzoylmethane derivative is present in an amount of 0.01 to 20% by weight based upon the total weight of the composition and the at least one merocyanine dicyano or cyanoacetate derivative is present in an amount of 0.1 to 10% by weight based upon the total weight of the composition.

19. The composition according to claim 1 , where the at least one dibenzoylmethane derivative is present in an amount of 0.1 to 10% by weight based upon the total weight of the composition and the at least one merocyanine dicyano or cyanoacetate derivative is present in an amount of 0.2 to 5% by weight based upon the total weight of the composition.

20. The composition according to claim 1 , where the at least one dibenzoylmethane derivative is present in an amount of 0.1 to 6% by weight based upon the total weight of the composition and the at least one merocyanine dicyano or cyanoacetate derivative is present in an amount of 0.2 to 5% by weight based upon the total weight of the composition.