PRODUCTION OF POLYIMIDE POWDER

摘要

PROBLEM TO BE SOLVED: To provide a process for producing a polyimide powder having a low content of a residual monomer or oligomer and being desirably used for molding a polyimide. SOLUTION: This process comprises: adding an aromatic tetracarboxylic acid or its diester derivative and an aromatic diamine to a solvent; heating the mixture under agitation to 80 deg.C or above to form a homogeneous solution; continuing the heating; separating polyimide particles precipitated at 120-250 deg.C by filtration to obtain a polyimide cake composed of flocked polyimide particles and containing the solvent; adding the solvent-containing polyimide cake to water to disperse the polyimide particles in the water to effect washing therewith; and separating the polyimide particles.