Patent ID: 7265185

Claim:
A process for selectively hydrogenating carbon-carbon double bonds of a polymer of a conjugated diene, an unsaturated nitrile and an unsaturated carboxylic acid, which comprises the steps of dissolving the polymer in a solution which consists of an organic solvent and then subjecting the polymer to hydrogenation in the presence of a rhodium-containing compound as catalyst and a co-catalyst ligand, wherein the weight ratio of the rhodium-containing compound to the co-catalyst ligand is from 1:3 to 1:55, wherein the polymer comprises from about 50 to about 85% conjugated diene, from about 15 to 50% of unsaturated nitrile and from about 0.1 to 10% unsaturated carboxylic acid, and wherein an insignificant amount of nitrile and carboxylic acids groups are reduced during hydrogenation.