Patent ID: 6127509
Filing Date: 2000-10-03
Classification: B32B,C08G,Y10S,Y10T

Abstract:
A polyimide polymer having a glass transition temperature of greater than about 300 degrees Centigrade comprising structural units derived from 3,4,3',4'-benzophenonetetracarboxylic dianhydride, 3,4,3',4'-biphenyltetracarboxylic dianhydride and one or more aromatic diamines, wherein the mole ratio of the structural units derived from 3,4,3',4'-benzophenonetetracarboxylic dianhydride to the structural units derived from 3,4,3',4'-biphenyltetracarboxylic dianhydride is in the range of from more than about 3.0/7.0 and up to about 4.0/1.0.