Process for the production of isocyanates, preferably diisocyanates and polyisocyanates with solvent recirculation

US8759569B2 · kind B2 · utility

Assignee

• BASF SE

Inventors

• Heiner Schelling · Ludwigshafen, DE
• Ulrich Penzel · Lauscha, DE
• Eckhard Stroefer · Mannheim, DE
• Matthias Eiermann · Schifferstadt, DE
• Jon S. Speier · Baton Rouge, US
• Kai Thiele · Ekeren, BE
• Michael Bock · Ruppertsberg, DE

Key dates

• Filing date: Jun 16, 2010
• Grant date: Jun 24, 2014
• Expiry date: Dec 3, 2030

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C07C263/10
• WIPO field: Organic fine chemistry
• WIPO sector: Chemistry

Abstract

The present invention relates to a process for the production of isocyanates, preferably diisocyanates and polyisocyanates of the diphenylmethane series (MDI), by reacting an amine with phosgene in the liquid phase or in the gas phase to form the corresponding isocyanates, subsequent removal of the solvent in at least two steps to obtain at least two solvent streams, individual treatment of the at least two solvent streams, and recirculation of at least a portion of the solvent streams.