Method of producing diamines and polyamines of the diphenylmethane series at different production capacities

US10626078B2 · kind B2 · utility

Assignee

• Covestro Deutschland AG · DE

Inventors

• Thomas Knauf · Dormagen, DE
• Stefan Wershofen · Mönchengladbach, DE
• Klaus-Gerd Gruner · Duisburg, DE
• Volker Hartjes · Duisburg, DE

Key dates

• Filing date: Dec 18, 2017
• Grant date: Apr 21, 2020
• Expiry date: Dec 18, 2037

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C07C211/50
• WIPO field: Organic fine chemistry
• WIPO sector: Chemistry

Abstract

The invention relates to a method for producing diamines and polyamines of the diphenylmethane series, by condensing aniline and formaldehyde followed by an acid-catalysed rearrangement at different production capacities. By adapting the temperatures in the acid-catalysed rearrangement step, the rearrangement reaction can be fully completed despite the change in dwell time inevitably associated with changed production capacity, with no undesired changes occurring in the product composition.