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:
Oct. 01, 2013
Filed:
Sep. 05, 2006
Matthias Kloetzer, Kroppen, DE;
Eckhard Stroefer, Mannheim, DE;
Volker Krase, Lauchhammer, DE;
Andreas Schmidt, Schwarzheide, DE;
Peter Scherbel, Schwarzheide, DE;
Matthias Kloetzer, Kroppen, DE;
Eckhard Stroefer, Mannheim, DE;
Volker Krase, Lauchhammer, DE;
Andreas Schmidt, Schwarzheide, DE;
Peter Scherbel, Schwarzheide, DE;
BASF Aktiengesellschaft, Ludwigshafen, DE;
Abstract
The invention provides a multistage process for continuously preparing organic, distillable polyisocyanates, preferably diisocyanates, more preferably aliphatic or cycloaliphatic diisocyanates, by reacting the corresponding organic polyamines with carbonic acid derivatives and alcohols to low molecular mass monomeric polyurethanes, and thermally cleaving said polyurethanes, in which at defined reaction stages the polyisocyanates prepared and unusable residues are separated off, and reusable by products and intermediates are recycled to upstream stages.