A process for producing polyimide microfine particles which is amenable to free control of particle morphology and particle diameter distribution is provided. A polyamic acid and a polyimide, each in the form of microfine particles with good monodispersibility, are also provided. There is also provided a process for producing polyimide microfine particles from a tetracarboxylic anhydride and a diamine compound which comprises (a) a first step of preparing a first solution containing the tetracarboxylic anhydride and a second solution containing the diamine compound, (b) a second step of mixing the first and second solutions and causing a polyamic acid to precipitate in the form of microfine particles from the mixed solution under ultrasonic agitation, and (c) a third step of imidating the polyamic acid particles to provide the objection polyimide in the form of microfine particles.
本发明提供了一种生产聚
酰亚胺微细颗粒的工艺,可自由控制颗粒形态和颗粒直径分布。本发明还提供了一种聚酰胺酸和一种聚
酰亚胺,它们都是具有良好单分散性的微细颗粒形式。还提供了一种用四
羧酸酐和二胺化合物生产聚
酰亚胺微细颗粒的工艺,该工艺包括 (a) 第一步,制备含有四
羧酸酐的第一溶液和含有二胺化合物的第二溶液、(b) 第二步,将第一和第二溶液混合,并在超声波搅拌下使聚酰胺以微细颗粒的形 式从混合溶液中析出,以及 (c) 第三步,将聚酰胺颗粒
酰亚胺化,以微细颗粒的形式提供反对聚
酰亚胺。