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:
Mar. 07, 1978
Filed:
Apr. 18, 1977
Helmut Heinze, Frankfurt am Main, DT;
Eberhard Hackel, Hochstadt, DT;
Zimmer Aktiengesellschaft, , DT;
Abstract
A batch process for esterifying ethylene glycol and terephthalic acid at elevated temperature and pressure in which a part of the ethylene glycol required for the complete esterification reaction is placed in an autoclave and heated under pressure, and the remainder of the glycol is added to said heated glycol in the form of a paste with terephthalic acid. Preferably the glycol initially present in the autoclave amounts to 0.3 to 0.8 moles per mole of terephthalic acid while the glycol added as a paste amounts to 1.4 to 0.9 moles per mole of terephthalic acid. The glycol initially in the autoclave may be glycol reclaimed from the mixture volatilized during the reaction and may contain up to 20% water, preferably 2-6% water.