Reactive hindered amine light stabilizers

Abstract From the Canadian patent

N-(2,2,6,6-tetraalkyl-4-piperidinyl)amide-hydrazides of dicarboxylic acids contain a light stabilizing group a heat, stabilizing group, and a reactive hydrazide functionality in the same molecule. The reactive stabilizers are prepared by reacting 4-amino-2,2,6,6-tetraalkylpiperidines with diesters (or mono ester acid chlorides) of dicarboxylic acids followed by hydrazinolysis of the ester group of the intermediate mono ester-amide. The compounds are useful for introducing permanent heat and light stability to coreactive polymers or copolymers.