| 摘要 |
Di(aminophenyl)methanes having a high proportion of o,p'-isomer (15-25 percent) are obtained by condensing aniline and formaldehyde in the presence of mineral acid, neutralizing the intermediate mixture of aminobenzylamines and, optionally, removing excess aniline and heating the aminobenzylamines in the presence of an aromatic primary amine (e.g., aniline) to produce the corresponding di(aminophenyl)methanes in admixture with polyfunctional polymethylene polyphenyl polyamines. The process has advantages over currently used methods of obtaining such amines in that it is readily adaptable to continuous operation and, in at least the heating step, is free from acid corrosion problems. |
