| 摘要 |
<p>PROBLEM TO BE SOLVED: To obtain the subject granular material, suitable as a raw material for the solid-phase polymerization, having a high rate of reaction of the solid- phase polymerization and excellent in handleability without causing the mutual fusion of a polycarbonate oligomer in the polymerization by thermally dissolving the oligomer in a solvent, then cooling the resultant solution, crystallizing the oligomer and molding the formed crystal into a granular shape. SOLUTION: (A) A polycarbonate oligomer is dissolved in (B) a solvent [e.g. an aromatic solvent or a mixed solvent of a poor solvent for the component (A) with the aromatic solvent] to provide, e.g. a solution of the component (A) at 20-90wt.% concentration. The resultant solution is then passed through a cooling pipe, deposited and taken out as a stringy crystallized material or droplets of the solution are brought into contact with a cooling gas and crystallized, etc., to cool the solution. Thereby, the solution is crystallized, then cut in the case of the stringy crystallized material, etc., and molded into a granular shape. Furthermore, the specific surface area and the mixing ratio of fine powder of the granular material are preferably respectively regulated to >=1m/g and <=5wt.%.</p> |
