Use of hals compounds

Abstract

A compound of formula I for use in stabilizing polymeric material against effects such as light and heat ##STR1## in which R is hydrogen; oxygen; --OH; C.sub.1-24 alkyl; --O--CO--C.sub.1-24 alkyl; --O--CO--C.sub.1-24 alkyl; --O--CO-phenyl or --COR.sub.5 ; where R.sub.5 is --C(R.sub.3).dbd.CH.sub.2, C.sub.1-6 alkyl, phenyl, CO--C.sub.1-24 alkyl, --CO--phenyl, --NR.sub.7 R.sub.8, --CH.sub.2 --C.sub.6 H.sub.5, --CO--OC.sub.1-12 alkyl or --COOH; where R.sub.3 is hydrogen or C.sub.1-4 alkyl; R.sub.7 is hydrogen, C.sub.1-12 alkyl, C.sub.5-6 cycloalkyl, phenyl, phenyl-C.sub.1-4 alkyl or C.sub.1-12 alkylphenyl and R.sub.8 is C.sub.1-12 alkyl or hydrogen, each R.sub.1, independently, is --CH.sub.3 or --CH.sub.2 (C.sub.1-4 alkyl) or both groups R.sub.1 form a group --(CH.sub.2).sub.5 --; and each R.sub.2, independently, is --CH.sub.3 or --CH.sub.2 (C.sub.1-4 alkyl) or both groups R.sub.2 form a group --(CH.sub.2).sub.5 --. A is --O-- or --N(C.sub.1-4 alkyl)-- or --NH-- R.sub.9 is hydrogen or methyl, and R.sub.10 is an aromatic single ring or an aromatic fused 2 to 3 ring group or a heteroaromatic single ring or a a heteroaromatic fused 2 or 3 ring group.