| 摘要 |
PURPOSE:To facilitate handling, drying, transportation and the like and simplify the process of granulation by a method wherein undried and solid polycarbonate is supplied to an extruder provided externally with a die having a multitude of fine holes and is extruded under a temperature lower than the melting point thereof, thereafter, is cut into a desired length. CONSTITUTION:Aromatic polycarbonate, employed in this method, is obtained by liquid solution method wherein the dihydric phenol is polymerized by reacting with phosgene or dichloroformate by a normal method under the existence of methylene chloride. The undried and solid polycarbonate is supplied to an extruder provided externally with a die having a multitude of fine holes to extrude it under a temperature lower than the melting point thereof, thereafter, is cut into a desired length to obtain granular products. When the internal temperature of the extruder becomes higher than the melting point of the polycarbonate in this case, the polycarbonate comes into liquidous state and drips down from the die and the rolling of the undried and solid polycarbonate becomes unstable. This solid carbonate is granulated into grains with a high bulk density and equal size, therefore, handling may be facilitated thereafter, process may be simplified and the device therefor may be miniaturized and simplified. |
