PRODUCTION OF POLYIMIDE FILM

摘要

PURPOSE:To produce a polyimide film having a high imidation ratio at low temperature while keeping a shape of a film of a polyamic acid. CONSTITUTION:A film of a polyamic acid containing 7-30wt.% good solvent is immersed in an immersing liquid containing an acid anhydride, ethers and/or ketones to imidate the polyamic acid. The polyamic acid can be obtained by reaction of an tetracarboxylic acid dianhydride with an aromatic diamine. The film of the polyamic acid can be obtained by a casting method. The imidation ratio of the objective polyimide film can be further increased by immersing a film of polyamic acid in the immersing liquid and then subjecting the film to heat treatment at lower temperature than a glass transition temperature of a polyimide.