VERFAHREN ZUR HERSTELLUNG VON POLYCARBONATEN

摘要

A method of making polycarbonates comprises melt-polymerizing an aromatic dihydroxy compound and a carbonic acid diester in a presence of a polymerization catalyst in a reactor system producing a byproduct stream, wherein the polymerization catalyst comprises a quaternary phosphonium compound; and purifying the byproduct stream to separate phenol, wherein the separated phenol has a phosphorus concentration of less than or equal to about 3 part per million, based upon the total weight of the phenol separated.