Patent ID: 7025904

Claim:
A heavy metal-free stabilizer for a poly(vinyl chloride) resin consisting essentially of from about 40% to about 80% by weight of a blocked mercaptan having the formula: wherein a is 1, m is 0, and n is 0 or 1; y=1 to 4; R 1 is R′C(O)OH wherein R′ is an alkylene radical having 2 or 3 carbon atoms, or R 1 is an alkyl, pentaerythrityl, alkylene, cycloalkyl, cycloalkylene, aryl, alkaryl, aralkyl, aralkylene, hydroxyalkyl, dihydroxyalkyl, alkoxyalkyl, acyloxyalkyl, hydroxy(polyalkoxy)alkyl, hydroxy(polyalkoxy)carbonylalkyl, acyloxy(hydroxyalkyl), acyloxy(alkoxyalkyl), acyloxy(polyalkoxy)alkyl, acyloxy(polyalkoxy)carbonlalkyl, alkoxycarbonylalkyl, oxy[bis(alkoxycarbonylalkyl)], oxy[bis(polyalkoxycarbonylalkyl)], benzoyloxy(polyalkloxy)alkyl, benzoyloxy(polyalkoxy)carbonylalkyl, alkylene bis-(acyloxyalkyl), thio-bis-[alkoxycarbonylalkyl], dithio-bis-[alkoxycarbonylalkyl], alkoxy(polyalkoxy)carbonylalkyl, hydroxyalkoxyalkyl, alkoxy(hydroxyalkyl), alkoxy(polyalkoxy)alkyl, mercaptoalkyl, mercaptoalkylene, mercaptoalkoxycarbonylalkyl, tetrahydropyranyloxy(polyalkoxy)carbonylalkyl, tetrahydropyranyloxyalkyl, hydroxyaryl, or mercaptoaryl radical, said alkyl, alkylene, alkoxy, and acyl radicals having from 1 to 22 carbon atoms; R 2 , R 3 , R 4 , R 5 , R 6 , and R 7 are independently hydrogen, a hydroxyl, mercapto, alkyl, alkylene, acyl, aryl, haloaryl, alkaryl, aralkyl, hydroxyalkyl, alkenyloxyalkoxy, alkoxy, aryloxy, alkaryloxy, mercaptoalkyl, hydroxyalkylmercaptoalkyl, mercaptoalkylene, hydroxyaryl, alkoxyaryl, alkoxyhydroxyaryl, arylcarbonyl, or mercaptoaryl radical having from 1 to 22 carbon atoms; X is a heteroatom selected from the group consisting of oxygen and sulfur, and one or both of the R 3 and R 5 alkylene radicals joins with R 7 and X to form a heterocyclic moiety with X as the heteroatom; and a zinc ionomer.