Compounds of formula I:
wherein R, R1 and R2 are independently straight or branched (C1-18)alkyl; (C5-12)cycloalkyl, optionally substituted with 1 to 3 straight or branched (C1-4)alkyl groups; an ammonium group optionally substituted with 1 to 4 straight or branched (C1-4)-alkyl groups; or a group of formula II
in which A is straigth or branched (C1-8)alkyl, (C5-8)cycloalkyl, or phenyl, optionally substituted with 1 to 3 straight or branched (C1-4)-alkyl groups, R3 is hydrogen or methyl and n is an integer from 1 to 10;
X1 and X2 are independently oxygen or the group NH; with the proviso that the two CO-X1-R1 and Co-X2-R2 groups cannot simultaneously be at the para position, the use thereof as protecting agents from UV-B radiations and as agents useful in the photostabilization of synthetic polymers.
式 I 的化合物
其中 R、R1 和 R2 独立地是直链或支链(C1-18)烷基;(C5-12)环烷基,任选被 1 至 3 个直链或支链(C1-4)烷基取代;
铵基,任选被 1 至 4 个直链或支链(C1-4)烷基取代;或式 II 的基团
其中 A 是直链或支链 (C1-8)烷基、(C5-8)环烷基或苯基,任选被 1 至 3 个直链或支链 (C1-4) 烷基取代,R3 是氢或甲基,n 是 1 至 10 的整数;
X1和X2独立地为氧或基团NH;但两个CO-X1-R1和Co-X2-R2基团不能同时位于对位,其用途是防止紫外线-B辐射,以及用作合成聚合物的
光稳定剂。