Patent ID: 6951898

Claim:
A cycloolefin copolymer resin having a Hunter b color value of less than 1.0, which resin comprises: a) first cycloolefin copolymer having a glass transition temperature of from about 100° C. to about 220° C., an intrinsic viscosity of from about 5 to about 1000 ml/g as measured in decalin at 135° C., and a molar-mass distribution (M w /M n ) of less than 2, b) from about 0.5 to about 10% by weight, based on the total weight of the resin, of a second cycloolefin copolymer, said second cycloolefin copolymer having a glass transition temperature of greater than about 50° C. and an intrinsic viscosity of from about 1 to about 500 ml/g as measured in decalin at 135° C., and c) from about 0.01% to about 3%, based on the total weight of the resin, of at least one lubricant selected from the group consisting of fatty acid esters of aliphatic polyhydric alcohols, with the proviso that the glass temperature of the second cycloolefin copolymer is at least 25° C. lower than the glass transition temperature of the first cycloolefin copolymer and wherein the resin is substantially free of zinc stearate.