METHOD FOR PRODUCING METHYLENE DIPHENYL DIAMINE (MDA) VIA THE AMINAL STAGE

摘要

The invention relates to a method for producing methylene diphenyl diamine (MDA) comprising the following steps a) to c): a) converting formaldehyde and aniline to an aminal, (b) removing water from the aminal obtained in step a), wherein a water content of 0 to 5 wt. % relative to the aminal is set, and c) adding an acid catalyst to the aminal with a water content of 0 to 5 wt. %, characterized in that in step a) formaldehyde is used as a highly concentrated formaldehyde with a CH2O content > 50 wt. % and the formaldehyde is produced by the oxidative dehydrogenation of methanol.