| 摘要 |
Provided are a method for preparing fine round powdery polycarbonate and a method for preparing a high molecular weight polycarbonate resin using the same. More specifically, provided are a method for preparing fine round powdery polycarbonate, comprising (A) polymerizing non-phosgene polycarbonate, (B) extruding the polycarbonate into fine round powdery amorphous polycarbonate, (C) surface-crystallizing the fine round powdery amorphous polycarbonate in the presence of a solvent or dispersion medium, and (D) drying the surface-crystallized fine round powdery polycarbonate, and a method for preparing high molecular weight polycarbonate resin capable of obtaining polycarbonates with various molecular weights ranging from low molecular weights to high molecular weights by continuously using the obtained fine round powdery polycarbonate via a solid state polymerization step. In accordance with the methods, it is possible to remarkably simplify crystallization of amorphous polycarbonate and thus to realize process continuousness and economical efficiency enabling commercial mass-production, and to overcome production of high molecular weight polycarbonate, the most serious problem of conventional non-phosgene melt polymerization processes. |
