PROCESS FOR PREPARING DIAMINES AND POLYAMINES FROM THE DIPHENYLMETHANE SERIES

摘要

Provided is a method for preparing diphenylmethane-based diamine and polyamine from aniline and formaldehyde to improve color value. A method comprises the step of reacting aniline and formaldehyde in the presence of an acid catalyst to prepare diphenylmethane-based diamine and polyamine, wherein the used aniline contains diphenylmethane-based diamine and polyamine in an amount less than about 3 wt%. Preferably the content of diphenylmethane-based diamine and polyamine in the used aniline is about 0.01-1 wt% based on the weight of aniline.