Stabilization of synthetic polymers

Claim 1

A process for stabilizing a synthetic polymer which comprises adding to the polymer a stabilizing amount of a compound of the formula: ##STR15## or a tautomer thereof wherein X is of the formula: ##STR16## wherein A is hydrogen, alkyl having 1 to 20 carbon atoms, alkenyl or alkinyl having 3 to 12 carbon atoms, aralkyl having 7 to 12 carbon atoms or --CH 2 --CHR 4 --OH wherein R 4 is hydrogen, methyl or phenyl; R 1 and R 2 are the same or different and are each alkyl having 1 to 12 carbon atoms or R 1 and R 2 together with the ring carbon atom to which they are attached form a cycloalkyl ring with 5 to 12 ring carbon atoms; R 3 is hydrogen, alkyl having b 1 to 20 carbon atoms, cycloalkyl having 5 to 12 carbon atoms, aralkyl having 7 to 12 carbon atoms, β-cyanoethyl, β-alkoxy carbonyl ethyl having 1 to 3 carbon atoms in the alkoxy moiety, aryl having 6 to 14 carbon atoms, --CH 2 --CHR 4 --OH wherein R 4 is hydrogen, methyl or phenyl, or ##STR17## wherein A, R 1 and R 2 are as defined above; Z has the same meaning as X or is --NUV wherein U and V are the same or different and are each hydrogen, alkyl having 1 to 20 carbon atoms, cycloalkyl having 5 to 12 carbon atoms, aralkyl having 7 to 12 carbon atoms or aryl having 6 to 14 carbon atoms, or said aryl substituted by alkyl having 1 to 8 carbon atoms, alkoxy having 1 to 4 carbon atoms, hydroxy, nitro, chlorine or by bromine and wherein the radical U may also be R 5 -W wherein R 5 is aryl having 6 or 10 ring carbon atoms, said aryl substituted by chlorine, bromine, methyl or by methoxy, alkyl having 1 to 8 carbon atoms or aralkyl having 7 to 12 carbon atoms; W is --CO or --SO 2 and R 6 is hydrogen, alkyl having 1 to 20 carbon atoms, cycloalkyl having 5 to 7 carbon atoms, aralkyl having 7 to 12 carbon atoms, aryl having 6 to 14 carbon atoms or said aryl substituted by alkyl having 1 to 8 carbon atoms, alkoxy having 1 to 4 carbon atoms, hydroxy, nitro, chlorine or by bromine.