Process for preparing an isocyanate by partly adiabatic phosgenation of the corresponding amine

US10875827B2 · kind B2 · utility

Assignee

• Covestro Deutschland AG · DE

Inventors

• Thomas Knauf · Dormagen, DE
• Juergen Spriewald · Kölln-Reisiek, DE
• Anke Hielscher · Cologne, DE
• Volker Michele · Cologne, DE
• Dietmar Wastian · Dormagen, DE
• Christian Steffens

Key dates

• Filing date: Nov 8, 2019
• Grant date: Dec 29, 2020
• Expiry date: Nov 8, 2039

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 preparing an isocyanate by reacting a primary amine with phosgene, comprising I) providing an amine solution, II) providing a phosgene solution, III) mixing the amine solution with the phosgene solution in a mixing unit, followed by IV) further conversion in an adiabatically operated reaction zone and the removing of the gas phase formed as a result of the chemical reaction in a separation zone, V) expanding the remaining liquid phase in two or three stages, VI) further conversion of the liquid phase remaining after the last expansion stage in an indirectly heated reaction zone and VII) isolating the isocyanate from the reaction solution obtained therein.