| abstract |
The invention relates to a process for the preparation of polyamines of the diphenylmethane series, comprising n a) reacting aniline and formaldehyde in the presence of an acid catalyst to form polyamines, and n b) neutralizing the reaction mixture formed in a) with a base, n wherein at least one alcohol is present during and/or after the neutralization step. The molar ratio of the alcohol to the formaldehyde is at least 0.02:1. n In addition, the present invention relates to a process for the preparation of polyisocyanates of the diphenylmethane series, according to the process as described above, additionally comprising: n c) phosgenating the resultant polyamines into the corresponding polyisocyanates of the diphenylmethane series. |