Process for photostabilizing of dibenzoylmethan derivatives of sunscreen agent, the photostable cosmetic sunscreen compositions and their use

摘要

Dibenzoyl-amine derivs. (I) are stabilised against degradation by UV light using amide cpds. (II). (I) is pref. 4-isopropyl-dibenzoylamine or esp. 4-t-butyl-4'-methoxy-dibenzoylamine (Ia). (II) are pref. cpds. of formula R2R3NC(O)R1 (where R1-R3 = H or opt. substd. 1-30C aliphatic or alicyclic hydrocarbyl, or R1+R2, R1+R3 or R2+R3 forms a 5-18C ring), esp. N,N-diethyl-3-methylbenzamide (IIa) or ethyl N-butyl-N-acetyl-aminopropionate (IIb). The compsns. contain 0.01-10 (esp. 0.1-6) wt.% (I) and 0.01-50 (esp. 0.1-30) wt.% (II).