| 摘要 |
Continuously or discontinuously preparing high molecular weight polyester or copolyester, comprises (a) processing at least 50 wt.% monomers or oligomers by mixing to form a paste, (b) reacting the paste by increasing the temperature and distilling condensation products or transesterification products, and (c) polycondensing or copolycondensing the obtained esterification- or transesterification product under reduced pressure compared with normal conditions, to obtain the polyester or copolyester having a molecular weight of 100000-150000 g/mole and a relative viscosity of 1.5-2. Continuously or discontinuously preparing high molecular weight polyester or copolyester, comprises (a) processing at least 50 wt.% monomers or oligomers comprising at least one (hetero)aromatic 4-12C dicarboxylic acid or its diesters, at least one aliphatic 2-12C dicarboxylic acid or its diesters or at least one 2-12C alkanol having at least two hydroxy groups, suitable for condensation reactions, by mixing to form a paste, and adding at least one catalyst which is stable for hydrolysis, during the preparation of the paste or into the ready-made paste, (b) reacting the paste by increasing the temperature and distilling condensation products or transesterification products to obtain an esterification- or transesterification product, and (c) polycondensing or copolycondensing the esterification- or transesterification product under reduced pressure compared with normal conditions, to obtain the polyester or copolyester having a molecular weight of 100000-150000 g/mole and a relative viscosity of 1.5-2. |
