PURPOSE: To obtain the subject powder having high bulk density and particle diameters advantageous for drying without using a specific device by grinding a precipitate while concentrating a solution of an aromatic polycarbonate obtained by interfacial polymerization method in an organic solvent.
CONSTITUTION: A solution of an aromatic polycarbonate which is obtained by interfacial polymerization method in an organic solvent (preferably dichloromethane) and has ≤500ppm water content is condensed in a device having a kneading mechanism at ≤ the boiling point of the solution of the polycarbonate in the organic solvent preferably by dehydrating and condensing the solution in the organic solvent by azeotropic distillation of water and the organic solvent and the precipitate is ground to give the objective powder.
OBUCHI SEIJI
OTA MASAHIRO
