Manufacturing polyesters

摘要

The present invention provides a continuous process of manufacturing polyester comprising introducing a polyol (7) and a polycarboxylic acid (9) into a pre-reactor (1) and allowing the polyol and the polycarboxylic acid to react to obtain a pre-polymer mixture including a polyfunctional ester; introducing the pre-polymer mixture (10) into the inlet section (13) of a distillation column (5) having a stripping section (15) and a rectifying section (16); supplying stripping gas (20) into the bottom of the distillation column (5); allowing the polyfunctional ester to polymerize in the stripping section (15) so as to form polyester and a gaseous mixture including water and unreacted reactants; removing polyester (30) from the distillation column (15); and allowing the gaseous mixture to pass through the rectifying section (16), removing from the top of the distillation column (5) a gaseous phase (35), at least partially condensing the gaseous phase and returning (46) part of the condensed gaseous phase as reflux into the distillation column (5).