The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Sep. 15, 1981
Filed:
Aug. 13, 1979
Rudolf Burkhardt, Troisdorf, DE;
Gunther Meyer, Troisdorf-Sieglar, DE;
Reinhard Schmidt, Witten, DE;
Klaus Thewalt, Witten-Bommern, DE;
Dynamit Nobel Aktiengesellschaft, Troisdorf, DE;
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.