| abstract |
(57) Abstract: A polyamic acid copolymer and a polyimide copolymer that provide useful and excellent properties to an electrically insulating material, an optical waveguide, and a proton conductive membrane such as a membrane for a polymer electrolyte fuel cell. And a method for producing a polyimide film. A polyfunctional component containing three or more amino groups, tetracarboxylic dianhydride or a derivative thereof, and / or Or, it contains a diamine as a main component and has a solid concentration of 1 It is achieved by a method for producing a polyamic acid copolymer, a polyimide copolymer and a polyimide film, characterized by reacting in an organic solvent solution adjusted to be 0% by weight or less. |