| 摘要 |
The invention relates to a continuous process for preparing a high molecular weight heteroaromatic polyester or copolyester, in which a) at least one heteroaromatic dicarboxylic acid or the diester or an acid anhydride thereof, a heteroaromatic dicarboxylic acid having 2-12 carbon atoms and at least one alcohol having 2 to 12 carbon atoms and at least two hydroxyl functionalities are processed by mixing to give a paste or by mixing at elevated temperature to give a homogeneous solution, b) the paste or solution obtained in step a) is converted to an esterification product comprising at least one diester and/or at least one oligoester, and c) the reaction product obtained from stage b) is polycondensed or copolycondensed under reduced pressure compared to standard conditions, the poly- or copolycondensation stage c) being performed in two stages. |
