Patent ID: 6274696
Filing Date: 2001-08-14
Classification: C08G

Abstract:
Process for the continuous production of segmented elastomer polyester copolymers composed of hard and soft segments, comprising a first reaction step in which, in a transesterification or esterification reaction, a segmented copolyester with a low molecular weight is formed from oligomer or polymer fed to the first reactor, which oligomer or polymer consists of units corresponding to the units of which the hard segments are composed, and polymer glycols yielding the units for the soft segments, and the low-molecular segmented polyester copolymer obtained in the first reaction step is in a second reaction step condensed to a desired degree of polymerisation, wherein the oligomer or polymer compound yielding the hard segments that is fed to the first reaction step has been obtained as part of a product stream in the synthesis of a polyester consisting entirely of ester units that form the hard segments of the segmented elastomer polyester copolymer, the remaining part of the product stream of the polyester yielding the hard segments being further polymerised to a desired degree of polymerisation in at least one further process step.