Process for preparing isocyanates

US8859805B2 · kind B2 · utility

Assignee

• BASF SE

Inventors

• Torsten Mattke · Ludwigshafen am Rhein, DE
• Matthias Kloetzer · Kröppen, DE
• Eckhard Stroefer · Mannheim, DE
• Bernhard Geissler · Schwarzenbruck, DE
• Peter Zehner · Ludwigshafen, DE

Key dates

• Filing date: Sep 9, 2010
• Grant date: Oct 14, 2014
• Expiry date: Dec 15, 2030

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C07C263/06
• WIPO field: Organic fine chemistry
• WIPO sector: Chemistry

Abstract

The invention relates to a multistage process for the continuous preparation of organic, distillable polyisocyanates, preferably diisocyanates, particularly preferably aliphatic or cycloaliphatic diisocyanates, by reaction of the corresponding organic polyamines with carbonic acid derivatives and alcohols to form low molecular weight monomeric polyurethanes and thermal dissociation of the latter, in which the polyisocyanates produced and unusable residues are separated off at particular stages of the reaction and reusable by-products and intermediates are recirculated to preceding stages.