Patent · US Expired

Method for the preparation of oligomeric alkylene terephthalates

US4289895A · kind A · utility

76Cited by

4References

13Claims

0Family size

Assignee

Dynamit Nobel GmbH · DE

Inventors

Rudolf Burkhardt · Troisdorf, DE
Gunther Meyer · Selb, DE
Reinhard Schmidt
Klaus Thewalt · Witten, DE

Key dates

Filing date	Aug 13, 1979
Grant date	Sep 15, 1981
Priority date	—
Expiry date	Aug 13, 1999

Classification

Technology area (CPC B)Performing Operations; Transporting
CPC primaryB01J2219/00182
WIPO fieldMacromolecular chemistry, polymers
WIPO sectorChemistry

Abstract

Oligomeric alkylene terephthalates having an average degree of condensation of 4 to 7 are produced by passing dimethylterephthalate and diol having at least 3 carbon atoms downwardly through a series of reaction chambers, each outfitted with stirring and heating means employed so that the temperature increases from stage to stage. Thereby transeterification is effected. The chambers are interconnected so that the methanol evolved in each chamber is vented without being admixed with the material undergoing transesterification in any of the other chambers. The transesterification product is then condensed at elevated temperature and under vacuum to produce the oligomer. The oligomers are high reactivity so that the further condensation thereof to polyesters is simplified.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.