公开(公告)号：US06646099B2

公开(公告)日：2003-11-11

申请号：US10180351

申请日：2002-06-26

申请人： Silke Kratschmer ,  Lothar Bunzel ,  Wolfgang Alewelt ,  Renate Wilms

发明人： Silke Kratschmer ,  Lothar Bunzel ,  Wolfgang Alewelt ,  Renate Wilms

IPC分类号： C08G6400

CPC分类号： C08G63/64

摘要： A transesterification process for producing polyester is disclosed. In a first stage of the process there is heated, in an inert gas atmosphere, a first mixture containing at least one dihydroxy compound and at least one diaryl carbonate to form an oligocondensate. In a second stage there is added to the oligocondensate at least one dicarboxylic acid to form a second mixture. The second mixture is heated to a temperature not higher than 290° C. in the presence of a quaternary onium compound as catalyst to form polyester carbonate. Hydroxyaryl formed throughout the process is distilled-off under reduced pressure.