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. 26, 2002
Filed:
Apr. 10, 2000
Applicant:
Inventors:
Karsten Eller, Ludwigshafen, DE;
Heinz Rütter, Hochdorf-Assenheim, DE;
Michael Hesse, Worms, DE;
Rainer Becker, Bad Dürkheim, DE;
Assignee:
BASF Aktiengesellschaft, Ludwigshafen, DE;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C07C 4/311 ; C07C 6/724 ; C08G 5/968 ;
U.S. Cl.
CPC ...
C07C 4/311 ; C07C 6/724 ; C08G 5/968 ;
Abstract
In a process for preparing polytetrahydrofuran, polytetrahydrofuran copolymers or diesters or monoesters thereof comprises polymerizing tetrahydrofuran in the presence of at least one telogen and/or comonomer over an acid-activated calcium montmorillonite as catalyst, the calcium montmorillonite has a BET surface area of at least 300 m /g, an acidity of at least 0.02 mmol/g at pK <−3 and a pore volume of at least 0.40 cm /g for pore sizes in the range from 30 to 200 Å.