Process for preparing isocyanates

US9796669B2 · kind B2 · utility

Assignee

• Covestro Deutschland AG · DE

Inventors

• Thomas Knauf · Dormagen, DE
• Andreas Rausch · Regensburg, DE
• Charles Bjoerndahl · Hohenwestedt, DE
• Matthias Ehlers · Marne, DE
• Peter Plathen · Krefeld, DE
• Carlos Alvarez Herrero · Tarragona, ES
• Francisco Munoz Velasco · Tarragona, ES

Key dates

• Filing date: Mar 24, 2015
• Grant date: Oct 24, 2017
• Expiry date: Mar 24, 2035

Classification

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

Abstract

The invention relates to a method for preparing isocyanates by the phosgenation of the corresponding amines in which problems resulting from the formation of deposits in apparatuses of the reaction segment during activation (starting) and deactivation (termination) of the method can be prevented by processing measures, in particular ensuring that there is a surplus of phosgene relative to the phosgenating amine during the critical starting and termination steps of the method.