Method for re-starting a continuous process for preparing polyether polyol

摘要

The invention relates to a method for re-starting a continuous process for preparing a polyether polyol by polymerizing an alkylene oxide in the presence of a double metal cyanide (DMC) catalyst, wherein the continuous process for preparing a polyether polyol comprises continuously adding a feedstream comprising the alkylene oxide and a feedstream comprising the DMC catalyst or a feedstream comprising the alkylene oxide and the DMC catalyst to a reactor and maintaining the temperature of the reaction mixture in the reactor at a value which is high enough to effect the polymerization; and the method for re-starting the continuous process for preparing a polyether polyol is a method for re-starting said process after stopping the addition of said feedstream or feedstreams to the reactor, which re-start method comprises starting addition of a feedstream comprising the alkylene oxide and a feedstream comprising the DMC catalyst or a feedstream comprising the alkylene oxide and the DMC catalyst to the reactor at a time point which is at most 300 hours after the time point at which the addition of said feedstream or feedstreams to the reactor is stopped.