Process for the production of polyamines

US4025557A · kind A · utility

Assignee

• BAYER HEALTHCARE LLC · DE

Inventors

• Willi Eifler · Bensberg, DE
• Hartmut Knofel · Odenthal, DE

Key dates

• Filing date: Nov 27, 1974
• Grant date: May 24, 1977
• Expiry date: Nov 27, 1994

Classification

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

Abstract

A process for condensing aromatic amines with formaldehyde in the presence of water is disclosed whereby an inhomogeneous mixture of a reaction product containing a large amount of 4,4'-diamino diphenylmethane is obtained which inhomogenity is due to a large quantity of water which is either present at the beginning of the condensation reaction or which if the reaction is carried out in the presence of relatively small amounts of water is obtained by the subsequent addition of water. The two phases are separated into an organic phase which is directly worked up by distillation without the necessity of an alkaline treatment. The aqueous phase is recycled to the beginning of the process. The process has the advantage of elimination of a salt free effluent, no consumption of acid catalyst and elimination of the need for alkaline reagents.