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

US10633327B1 · kind B1 · utility

Assignee

• Covestro Duetschland 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 28, 2020
• Expiry date: Dec 18, 2037

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C07C209/84
• 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. Adapting the respective molar ratios of the total used aniline to the total used formaldehyde and of the total used acid catalyst to the total used aniline allows the rearrangement reaction to be fully completed despite the change in dwell time inevitably associated with a change in production capacity and ensures that no undesired fundamental changes occur in the product composition.