BigPatents India

A radiation curable composition comprising a urethane oligomer with a polyester backbone which composition, when cured, has improved hydrolytic stability. The composition comprises a urethane oligomer, having a polyester backbone with a number average molecular weight of less than about 1000, wherein the polyester backbone is at least in part based on a diol component wherein at least one carbon at the b-position with respect to a hydroxyl group bears two carbon-containing substituents having a total of at least three carbon atoms. Alternatively,when the composition comprises a urethane oligomer with a number average molecular weight of less than about 2000, having a polyester polyol backbone with a number average molecular weight of less than about 1000, the polyester backbone is at least in part based on a diol component wherein at least one carbon at the b- position with respect to a hydroxyl group bears at least one carbon -containing substituent.