Novel light stabilizers for polymers

Claim 1

An oligomer of the formula (I) ##STR9## wherein X and X 1 , which are the same or different, represent hydrogen, C 1 -C 20 alkyl, or the radical (II) ##STR10## wherein R 1 represents hydrogen, C 2 -C 3 hydroxyalkyl, C 1 -C 8 alkyl, hydroxyl, or oxyl; R 2 represents hydrogen, C 1 -C 8 alkyl, or benzyl; R 3 and R 4 , which are the same or different, represent C 1 -C 8 alkyl, benzyl, or phenethyl, or together with the carbon to which they are attached form a C 5 -C 10 cycloalkyl; Z represents C 2 -C 20 alkylene, either straight-chained or branched, wherein the alkylene chain is optionally interrupted by oxy, thio, or ##STR11## radicals, wherein R 5 represents hydrogen, C 1 -C 20 alkyl, or the radical (II); C 5 -C 10 cycloalkylene, ##STR12## C 6 -C 12 arylene, or C 8 -C 14 aralkylene; n is an integer greater than 1; and, Y represents a halogen atom, C 1 -C 8 alkylamino, di(C 1 -C 8 )alkylamino, pyrrolidyl, morpholino, or ##STR13## wherein X, X 1 , and Z are as previously defined; with the proviso that at least one piperidinyl moiety of formula (II) is present in the repeating unit.