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. 14, 2000
Filed:
Dec. 28, 1998
Wulfrich Friedemann Beer, Frankenthal, DE;
Klaus Beiser, Eppelsheim, DE;
Jurgen Ciprian, Ludwigshafen, DE;
Lothar Franz, Mutterstadt, DE;
Wolfgang Franzischka, Frankenthal, DE;
Christof Palm, Ludwigshafen, DE;
Frank-Friedrich Pape, Kleinniedesheim, DE;
Axel Paul, Lampertheim, DE;
Ulrich-Dieter Pessel, Heidelberg, DE;
Alexander Weck, Buhlertal, DE;
BASF Aktiengesellschaft, Ludwigshafen, DE;
Abstract
The invention relates to a process for preparing hydroxyl-containing polymers, in particular for preparing polytetrahydrofuran with terminal hydroxyl groups, from the corresponding acyloxy-containing polymers by transesterification with alcohols in the presence of a sodium-containing catalyst. In this process the polytetrahydrofuiran solution is passed in the presence of a catalytic amount of water directly through at least one ion exchanger following the transesterification in order to remove the sodium cations. The novel process makes it possible to remove the sodium cations from the sodium-containing catalyst in an economic manner and with little complexity. The residual sodium content can be reduced to values of less than 0.5 ppm.