Abstract: In a step of polymerizing polyamic acid by mixing tetracarboxylic acid dianhydride and diamine and polycondensating the tetracarboxylic acid dianhydride and diamine under the presence of a polymerization-use solvent, a tetracarboxylic acid dianhydride slurry in which a tetracarboxylic acid dianhydride is dispersed in a dispersion medium is used. According to this, it is possible to directly manufacture a polyamic acid solution having a high concentration of polyamic acid more than or equal to 10% by weight. Especially, even if a tetracarboxylic acid dianhydride having low solubility in the polymerization-use solvent, it is possible to effectively manufacture a polyamic acid solution having high solids content, by a simple process and in a short time.
Type:
Grant
Filed:
December 19, 2002
Date of Patent:
February 8, 2005
Assignee:
Kanera Corporation
Inventors:
Kan Fujihara, Kazuhiro Ono, Kiyokazu Akahori