PREPARING METHOD OF POLYIMIDE POWDER, POLYIMIDE POWDER, POLYIMIDE-POWDER MOLDED ARTICLE AND ITS MANUFACTURING METHOD

摘要

PROBLEM TO BE SOLVED: To provide a polyimide powder whose particle diameter can be controlled and that has a superior filtrability and anti-adherence between particles, and provide a polyimide-powder molded article that has a superior heat resistance and mechanical properties, and provide their manufacturing methods. SOLUTION: The preparing method of the polyimide powder is such that a polyimide's precursor prepared by a reaction in the presence of 5-100% imidazole toward the carboxylic acid quantity of the polyimide's precursor is deposited in a water soluble ketone solvent containing an amide solvent of 3-30 wt.% and is heated until the imidation rate has exceeded 90%. The polyimide-powder molded article of a biphenyltetracarboxylic acid having a density exceeding 1.3 g/mm3, a tensile strength exceeding 800 kg/cm2 and a tensile break-elongation exceeding 10% and the polyimide powder and their manufacturing methods are provided.