公开(公告)号：US3859257A

公开(公告)日：1975-01-07

申请号：US17065471

申请日：1971-08-10

Applicant: DYNAMIT NOBEL AG

Inventor： SCHADE GERHART ,  MELIN HANS

IPC: C08G63/181 ,  C08G63/78 ,  C08G17/013

CPC classification number: C08G63/181 ,  C08G63/78

Abstract: Improvements in the production of polyesters of dicarboxylic acid moieties and 1,4-butanediol moieties, where at least some of the acid moieties are aromatic, by catalytic direct or transesterification of the acids or esters thereof with a molar excess of 1,4- butanediol, whereby reducing the amount of excess 1,4-butanediol required to produce commercially acceptible polyesters, which comprises reacting the 1,4-butanediol with the dicarboxylic acid or an ester thereof in a mole ratio of 1.05 to 1.25:1 respectively at temperatures of less than 200*C while distilling off the volatile cleavage products including the 1,4butanediol until the flow of butanediol has been reduced to less than about 10 percent of its initial removal rate, and then polycondensing this product at temperatures above 200*C in the usual manner.