Process for producing polyester ether copolymer

Abstract

The present invention provides a process for producing a polyester ether copolymer which comprises conducting polycondensation after or while melting and mixing a polyester, of 0.3 (dl/g) or more in intrinsic viscosity, and a polyether having hydroxy groups or their derivatives at its terminals and having a molecular weight of 200 or more. The present invention can dispense with the steps of esterification, transesterification, etc., because of the use of the preformed polyester. Moreover, it shortens the reaction time so that only a small quantity of polyester is produced as a by-product. In addition, since the thermal history of the polyesterh is so small, deterioration of the polymer during production is suppressed. Furthermore, this process enables continuous production of products with good quality, which serves to markedly improve productivity.

Dependencies are inferred from the claim text.