| 摘要 |
PURPOSE:To obtain the titled powder excellent in the flow of the resin component, by adding fine particles and/or a fibrous filler to the reaction system during a specified period of thermal polymerization of an aromatic tetracarboxylic acid dianhydride and an aromatic polyisocyanate. CONSTITUTION:5-80wt% mixture of an aromatic tetracarboxylic acid anhydride (A) (e.g., 3,3',4,4'-biphenyltetracarboxylic acid dianhydride), 1mol, per mol of component a, of an aromatic polyisocyanate (B) and, optionally, a catalyst is polymerized by heating at 100-200 deg.C in an organic polar solvent (e.g., N- methyl-2-pyrrolidone). During a period before polyimide particles are deposited, fine-particulate filler of an average particle diameter <=1mum and a bulk density <=0.15g/cc and/or a fibrous filler of a mean length of <=300mum and a bulk specific gravity of 0.01-0.5g/cc (e.g., graphite) (C) dispersed in an organic polar solvent are added to the reaction system to obtain a polyimide powder containing 1-50wt% component C as nuclei.
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