| 摘要 |
PROBLEM TO BE SOLVED: To provide a process for efficiently producing an aromatic polycarbonate (PC) resin, which can, when producing different grade PC resins by switching operation by changing reaction conditions, shorten the term till reaching to the steady state after performing the switching operation. SOLUTION: Provided is a method for producing PC resin A having viscosity-average molecular weight Ma and then, by using the same production system, producing PC resin B having viscosity-average molecular weight Mb smaller than the Ma, wherein the method comprises at least a purification step removing foreign bodies by passing the molten state PC resin, obtained by ester exchange reaction, through a polymer filter (P/F) by using a melter extruder, and, as the P/F, a P/F having large aperture is used in production of the PC resin A and a P/F having smaller aperture is used in production of the PC resin B. When switching from the PC resin A to the PC resin B, the P/F is switched to one having small aperture and the difference between the fish eye (FI) number of 2 hr before switching and the FI number of 1 hr after switching is 10 or less. COPYRIGHT: (C)2009,JPO&INPIT
|
