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

US7205439B2 · kind B2 · utility

Assignee

• Bayer MaterialScience AG · DE

Inventors

• Torsten Hagen · Essen, DE
• Stefan Peter Grabowski · Neuss, DE
• Richard Adamson · Leichlingen, DE
• Daniel Koch · Shanghai, CN
• Stefan Wershofen · Mönchengladbach, DE

Key dates

• Filing date: Mar 28, 2006
• Grant date: Apr 17, 2007
• Expiry date: Mar 28, 2026

Classification

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

Abstract

Di- and polyamines of the diphenylmethane series are prepared by a) mixing a first portion of aniline with an acid catalyst, b) mixing a second portion of aniline with formaldehyde, and c) mixing and reacting the mixtures prepared in each of steps a) and b). The diamines produced by this process may then be phosgenated to produce the corresponding di-/polyisocyanate.