| abstract |
Compounds of formula I. wherein R₁ is C₁-C₄-n-alkyl, isopropyl, s-butyl, cyclopentyl, cyclohexyl or α-methylbenzyl, R₂ is C₄-C₁₈-tert-alkyl or α, α-dimethylbenzyl, R₃ is C₁-C₂₈-alkyl and R₄ is methyl or ethyl, with the proviso that the group -CHR₃R₄ contains at least 4 carbon atoms, are suitable for stabilizing organic material which is sensitive to thermal, oxidative or actinic degradation. |