Process for the preparation of polyaryl amines having methylene bridges

In a process for the preparation of polyaryl amines having methylene bridges from arylamines and formaldehyde in the presence of acids wherein 0.25-1.3 mol of formaldehyde per mol of arylamine is added in a first mixing step in the presence of 0.85-1.01 mol of acid, the improvement which comprises adding at least 0.1 mol of free arylamine before the formed compounds of the anhydroformaldehyde aniline type are noticeably rearranged into benzyl anilines, then reacting the reaction mixture at temperatures between 30.degree. and 70.degree. C. to form benzyl anilines and, finally, converting the resulting precondensate at temperatures between 70.degree. and 120.degree. C. into polyamines having methylene bridges.