| 摘要 |
PURPOSE:To narrow the particle size distribution of a granular substance, by a method wherein a solvent solution of a core substance containing a substance charged positively or negatively in a charging system is dispersed in a liquid of a substance charged so as to have polarity inverse to that of the core substance to be emulsified therewith before a solvent is removed. CONSTITUTION:A solvent solution of a core substance containing one or more kinds of substances charged positively or negatively in a charging system is dispersed in and emulsified with a liquid having a substance not compatible with said solvent solution and charged so as to have polarity inverse to that of the core substance dispersed or dissolved therein. Subsequently, the solvent dissolving the core substance is removed to prepare a granular substance. The granular substance can be also formed by forming a wall film after the solvent dissolving the core substance is removed. As the substance having positive charge, there are ethyl cellulose, polyacrylic ester, etc., and, as the substance having negative charge, there are carboxy methyl cellulose, gum arabic, polystyrene, etc. |
