Abstract: A process for the manufacture of a crystallized polycarbonate resin prepared via the transesterification of a diaryl carbonate and a dihydric phenol comprising adding to the polycarbonate resin a minor amount of a lithium compound nucleating agent.

Abstract: A process for the production of a substantially clear and colorless, or at most slightly tinted, polyarylcarbonates useful to form molded structural and engineering articles suitable to replace metal parts, or for use in electrical appliances to form lenses, safety shields, instrument windows and the like is disclosed.The tendency of color formation in polycarbonates and polyarylates prepared by transesterification and polycondensation is reduced or inhibited by carrying out the transesterification reaction while the reaction mixture contacts only metal surfaces of selective metals, or glass. The metal surfaces are provided by such metals as tantalum, nickel, or chromium or mixtures thereof. The reaction is carried out in reactors or systems which are substantially totally made of such metals, or reactors or systems clad or lined with a layer of such metals or glass.