公开(公告)号：AT364652T

公开(公告)日：2007-07-15

申请号：AT03749032

申请日：2003-08-11

Applicant: GEN ELECTRIC

Inventor： SILVA JAMES ,  BUI PIERRE-ANDRE ,  FYVIE THOMAS ,  DARDARIS DAVID

IPC: C08G64/28

Abstract: A new method of converting oligomeric chloroformates to high molecular weight polycarbonate is presented. By carefully controlling the relative concentrations and amounts of hydroxyl and chloroformate groups present in the oligomeric polycarbonate, the method of the invention provides for the efficient preparation of polycarbonate while minimizing phosgene usage. The product polycarbonates prepared by the method of the invention are fully capped with no additional phosgene required beyond that needed to prepare the oligomeric chloroformate starting material. The method of the present invention provides polycarbonates having non-detectable levels (

公开(公告)号：AT368699T

公开(公告)日：2007-08-15

申请号：AT03714026

申请日：2003-03-11

Applicant: GEN ELECTRIC

Inventor： SILVA JAMES ,  DARDARIS DAVID ,  O'NEIL GREGORY ,  SYBERT PAUL ,  SU ZHAOHUI

IPC: C08G63/64 ,  C08G64/22

Abstract: Thermally stable block copolyestercarbonates comprising chain members derived from at least one dihydroxy-substituted aromatic hydrocarbon moiety and at least one aromatic dicarboxylic acid moiety, said polymer being substantially free of anhydride linkages linking at least two mers of the polyester chain segments, are prepared by a method comprising the steps of: (a) preparing a hydroxy-terminated polyester intermediate comprising structural units derived from at least one dihydroxy-substituted aromatic hydrocarbon moiety and at least one aromatic dicarboxylic acid moiety; and (b) conducting a reaction of the polyester intermediate with phosgene in a reaction mixture comprising water, a substantially water-immiscible organic solvent, and a base, wherein base and phosgene are added simultaneously to the reaction mixture at a substantially constant molar ratio of base to phosgene for a time period of at least about 60% of the total amount of phosgene added.