Patent ID: 7790836

Claim:
A polyamic acid, comprising: a diamine compound according to either of Formula 1 or Formula 2; wherein, A and A′ are each, independently, a single bond, or are selected from the group consisting of —O—, —COO—, —OCO—, and —NHCO—; B is a single bond or a divalent benzene ring m is 1 to 3; n is 2 or 3; G is a single bond (when m is 1), a trivalent benzene ring when m is 2), or a tetravalent benzene ring when m is 3); and R is a linear, branched, or cyclic alkyl or fluoroalkyl group having 1 to 30 carbons an aliphatic cyclic acid dianhydride; an aromatic cyclic acid dianhydride; and optionally an aromatic cyclic diamine; wherein the diamine compound, the aliphatic cyclic acid dianhydride, the aromatic cyclic acid dianhydride, and optionally the aromatic cyclic diamine are copolymerized, thereby producing the polyamic acid.