Patent ID: 9309184
Filing Date: 2016-04-12
CPC Classification: B01D,C07C

Claim Text:
1. A process for the preparation of di- and polyamines of the diphenylmethane series, comprising: a) converting aniline and formaldehyde in the absence of an acidic catalyst to a reaction mixture comprising aminal and water, b) removing water at least in part from the reaction mixture obtained in step a), giving an organic phase (1) comprising the aminal, c) converting the organic aminal-comprising phase (1) obtained in step b) in the presence of an acidic catalyst, giving a reaction mixture comprising di- and polyamines of the diphenylmethane series, and d) neutralizing the reaction mixture comprising di- and polyamines of the diphenylmethane series obtained in step c) and then subjecting the neutralized reaction mixture to a work-up involving washing and distillation, wherein the separation of the water from the reaction mixture obtained in step a) comprises b.1) separating the reaction mixture obtained in step a) in a separating container into an aqueous and an organic phase (1a), and then b.2) passing the aqueous phase obtained in step b.1) b.3) combining the organic phase (1b) obtained in step b.2) with the organic phase (1a) obtained in step b.1) to give the organic phase (1).