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:
Dec. 02, 2003
Filed:
Dec. 19, 2001
Applicant:
Inventors:
Assignee:
BASF Aktiengesellschaft, Ludwigshafen, DE;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C08G 6/378 ;
U.S. Cl.
CPC ...
C08G 6/378 ;
Abstract
The invention relates to a method for the continuous production of polybutylene terephthalate from terephthal acid and 1,4-butane diole, comprising the following stages: a) direct esterification of terephthal acid with 1,4-butane diole in a reactor cascade of at least two reactors b) pre-condensation of the esterification product obtained in stage a), c) polycondensation of the pre-condensate obtained in stage b), whereby the temperature of the reactor cascade in stage a) is progressively decreased during its operation.