Patent ID: 6710160
Filing Date: 2004-03-23
Classification: C08G,G01N

Abstract:
A polyamic acid having repeating units represented by the formula (1): wherein the norbornane skeleton of comprises four components of and their contents satisfy the following:1%&lE;2,5-[diexo]&lE;90%, 1%&lE;2,5-[exo,endo]&lE;90%, 1%&lE;2,6-[diexo]&lE;90%, 1%&lE;2,6-[exo,endo]&lE;90%, provided that(2,5-[diexo])+(2,5-[exo,endo])+(2,6-[diexo])+(2,6-[exo,endo])=100%. R represents a tetravalent group having from 4 to 27 carbon atoms and selected from the group consisting of an aliphatic group, a monocyclic aliphatic group, a condensed polycyclic aliphatic group, a monocyclic aromatic group, a condensed polycyclic aromatic group, and a non-condensed polycyclic aliphatic or aromatic group which is composed of cycloaliphatic or aromatic groups mutually bonded to each other either directly or via a crosslinking member, wherein the polyamic acid has an inherent viscosity measured in a solvent of N-methyl-2-pyrrolidone having an acid concentration of 0.5 g/dl at 35Â° C. that falls between 0.1 and 3.0 dl/g.