Patent attributes
A method for stably producing an aromatic polycarbonate, which comprises continuously reacting an aromatic dihydroxy compound with a diaryl carbonate in a closed, reactor-pipeline system, the closed, reactor-pipeline system comprising: a plurality of reactors which are liquid-tightly connected through a pipeline toward an outlet for a final aromatic polycarbonate product, the pipeline comprising one or more pipes, wherein the plurality of reactors include at least two reactors connected in series, and at least one filter secured in the pipe or pipes of the reactor-pipeline system, wherein the or each filter is simultaneously or separately taken out to the outside of the reactor-pipeline system and subjected to washing in the outside of the reactor-pipeline system, followed by returning of the resultant washed filter into the inside of the pipe or pipes of the reactor-pipeline system, the washing being performed with the below-mentioned washing agents used in the following order: an aqueous solution of a basic compound, an aromatic monohydroxy compound, and a molten mixture of an aromatic dihydroxy compound and a diaryl carbonate, the molten mixture containing a basic compound.
