Process for production of polymer particles

摘要

An efficient method of obtaining polymer particles by evaporating an organic solvent while maintaining a solution of a polymer in the organic solvent in contact with polymer particles, using a simple apparatus and a simple procedure. The polymer particles (powder) produced by the method have a small particle diameter, a high bulk density, a small amount of residual solvent, and are thus excellent in quality. The method includes introducing the organic solvent solution of the polymer into a particle producing zone which does not substantially contain steam, wherein an atmosphere is maintained in which the organic solvent is vaporizable and the particles are stirred. The organic solvent is evaporated, while maintaining the solution in contact with the polymer particles. Additionally a breaker is used in combination with a mixer; a poor solvent is employed; polymer particles are recycled; or a horizontal particle producing vessel is utilized.