PROCESS FOR THE PREPARATION OF DI- AND POLYAMINES OF THE DIPHENYLMETHANE SERIES

摘要

The invention relates to a method for producing diamines and polyamines of the diphenylmethane series, wherein first aniline and formaldehyde are reacted in the absence of an acidic catalyst to form a reaction mixture containing aminal and water and, after the water has been separated, the aminal is reacted by acid catalysis to form a reaction mixture containing diamines and polyamines of the dephenylmethane series, wherein the separation of the water and aminal is supported by the use of a coalescence aid. According to the invention, a filter bed made of coalescence fiber material is used as coalescence aid.

主权项

1. A process for the preparation of di- and polyamines of the diphenylmethane series, comprising:
a) reacting aniline and formaldehyde in the presence of an acidic catalyst to give a reaction mixture comprising di- and polyamines of the diphenylmethane series, b) neutralizing the reaction mixture comprising di- and polyamines of the diphenylmethane series, c) separating the neutralized reaction mixture comprising di- and polyamines of the diphenylmethane series in a separation container into an organic phase (1) comprising di- and polyamines of the diphenylmethane series and an aqueous phase, d) further purifying the organic phase (1) comprising di- and polyamines of the diphenylmethane series in a washing container with washing liquid, e) freeing the mixture obtained in step d) from aqueous constituents, giving an organic phase (2) comprising di- and polyamines of the diphenylmethane series, and freeing the organic phase (2) comprising di- and polyamines of the diphenylmethane series distillatively from water and aniline, wherein the separation off of the aqueous constituents in step e), comprises: e.1) separating the mixture obtained in step (d) in a separating container into an aqueous and an organic phase (2a), and then e.2) passing the organic phase (2a) obtained in step e.1) through a filter bed made of coalescence fiber material and then separating the organic phase obtained thereby into an aqueous phase and the organic phase (2).