METHOD FOR REMOVING ORGANIC SOLVENT REMAINING IN FINE PARTICLE

摘要

PROBLEM TO BE SOLVED: To efficiently and almost completely remove an organic solvent remaining in fine particles in a short time by heating the fine particles in which an organic solvent having a lower boiling point than water is contained in a water phase at a temperature higher than the boiling point of the organic solvent. SOLUTION: An organic solvent (preferably an organic solvent having a boiling point >=10 deg.C less than that of water, e.g. a halogenated aliphatic hydrocarbon-based solvent) remaining in fine particles consisting of an agent and a polymer (e.g. the polyester of a hydroxyfatty acid) hardly soluble in water is removed by heating the fine particles in a water phase at a temperature higher than the boiling point of the organic solvent (preferably at a temperature >=5 deg.C higher than the boiling point). The initial residual amount of the organic solvent in the fine particles is preferably <=40 wt.%. The ratio of the fine particles to the water phase is preferably 0.1-1000 g per 1 litter of the water phase without containing the fine particles. Thus, highly safe fine particle formulations are easily provided.