Process for preparation of di- and polyamines of the diphenylmethane series

US10125091B2 · 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: Jun 22, 2015
• Grant date: Nov 13, 2018
• Expiry date: Jun 22, 2035

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C07C209/78
• WIPO field: Organic fine chemistry
• WIPO sector: Chemistry

Abstract

The invention relates to a method for the preparation of di- and polyamines of the diphenylmethane series (MDA) from aniline and formaldehyde, care being taken during the start up that a sufficient excess of aniline with respect to formaldehyde is ensured, said excess amounting to at least 105% of the desired molar ratio of aniline to formaldehyde for the target recipe of the MDA to be produced.