| 摘要 |
Provided is a solvent soluble polyimide copolymer that satisfies a high level of storage stability and heat resistance and that has superior utility. The polyimide copolymer has a glass transition temperature not observed below 500°C and results from the copolymerization of 3,3',4,4'-biphenyltetracarbonxylic acid dianhydride and (B) a diamine and/or a diisocyanate. Preferably, component (B) is at least one diamine and/or diisocyanate represented by general formulae (1) to (3) (in the formulae: X is an amino group or an isocyanate group; R1 to R8 are each individually a hydrogen atom, an alkyl group having 1-4 carbon atoms, an alkenyl group having 2-4 carbon atoms, or an alkoxy group having 1-4 carbon atoms; and of R1 to R8, at least one is not a hydrogen atom). |
