Antioxidant combination of esters and amines

Claim 1

A synergistic antioxidant system comprising an ester having the following structural formula ##STR5## and an amine antioxidant selected from the group consisting of polymerized and non-polymerized derivatives of 2,2,4-trimethyl-1,2-dihydroquinoline, N,N'-di-substituted-p-phenylenediamines having the following structural formula ##STR6## diphenyl amines having the following structural formula ##STR7## and amides having the following structural formula ##STR8## wherein n is an integer from 1 to 4, wherein R is selected from the group consisting of hydrogen and methyl, wherein when n is 1, R 1 is selected from the group consisting of alkyl radicals having 1 to 18 carbon atoms, aryl radicals having 6 to 12 carbon atoms, aralkyl radicals having 7 to 12 carbon atoms and cycloalkyl radicals having 5 to 12 carbon atoms wherein when n is 2, R 1 is selected from the group consisting of alkylene radicals having 2 to 18 carbon atoms, cycloalkylene radicals having 5 to 12 carbon atoms, arylene radicals having 6 to 12 carbon atoms, ##STR9## polyalkyl glycol ether radicals having the following structure -- CH.sub.2 -- CH.sub.2 -- O).sub.n 1 CH.sub.2 -- CH.sub.2 -- wherein n 1 is an integer from 1 to 7, a thioether radical having the following structure -- CH.sub.2 -- CH.sub.2 -- S -- CH.sub.2 -- CH.sub.2 -- wherein when n is 3 or 4, R 1 is an aliphatic hydrocarbon radical having the formula CyH2y+2-n, wherein y is an integer from 3 to 6 and wherein R 2 is selected from the group consisting of alkyl radicals having 1 to 24 carbon atoms, aryl radicals having 6 to 12 carbon atoms and aralkyl radicals having 7 to 12 carbon atoms, wherein R 3 and R 4 are selected from the group consisting of alkyl radicals having 3 to 12 carbon atoms, aryl radicals having 6 to 12 carbon atoms and aralkyl radicals having 7 to 12 carbon atoms, wherein R 5 , R 6 , R 7 and R 8 are selected from the group consisting of hydrogen, alkyl radicals having 1 to 20 carbon atoms and aralkyl radicals having 7 to 12 carbon atoms, wherein R 12 is an arylene radical having 6 to 12 carbon atoms, R 9 and R 10 are selected from the group consisting of hydrogen, alkyl radicals having 1 to 4 carbon atoms and alkoxy radicals having 1 to 4 carbon atoms, R11 is selected from the group consisting of hydrogen, alkyl radicals having 1 to 4 carbon atoms and alkoxy radicals having 1 to 4 carbon atoms and wherein R 13 and R 14 are selected from the group consisting of hydrogen and alkyl radicals having 1 to 4 carbon atoms and R 15 is selected from the group consisting of hydrogen, alkyl radicals having from 1 to 4 carbon atoms and aryl radicals having 6 to 12 carbon atoms.