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:
Apr. 12, 2005
Filed:
Aug. 20, 2002
Jürgen Ciprian, Ludwigshafen, DE;
Wulfrich Friedemann Beer, Neustadt, DE;
Volkmar Menger, Neustadt, DE;
Jürgen Ciprian, Ludwigshafen, DE;
Wulfrich Friedemann Beer, Neustadt, DE;
Volkmar Menger, Neustadt, DE;
BASF Aktiengesellschaft, Ludwigshafen, DE;
Abstract
In a process for preparing polytetrahydrofuran having terminal OH groups (PTHF) from the corresponding polytetramethylene ether having acyloxy end groups by transesterification with alcohols in the presence of a sodium-containing catalyst followed by passing the alcoholic PTHF solution in the presence of a catalytic amount of water directly through at least one ion exchanger to remove the sodium ions, the removal of the sodium ions is carried out in a fully continuous ion exchange unit which comprises: