| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for manufacturing a polycarbonate resin capable of largely improving the stability of molecular weight of the polymer. SOLUTION: A method for continuously manufacturing a polycarbonate through an ester interchange reaction by placing two or more reactors in series. In the method, the molecular weight of the polymer at the discharging side of a reactor is continuously measured by placing a metering pump directly behind one or more reactors, and further placing a pressure difference meter and a thermometer on the downstream side of the metering pump. The deviation and the speed of changing to be held are measured at an interval of 1 to 120 min, a PID action controller is actuated according to the measurements to control vacuum automatically, and the vacuum-keeping operation is repeated at an interval of 1 to 120 min so that the molecular weight is kept constant.
|
