Abstract: A process for preparing 4-aminodiphenylamine having the steps of reacting nitrobenzene and aniline in the presence of a complex base catalyst, hydrogenating the reaction mixture with hydrogen, a powdery composite catalyst, and a hydrogenation solvent; separating, recovering, and reusing the complex base catalyst and the powdery composite catalyst from the reaction mixture; separating, recovering, and reusing aniline, and optionally water, from the the reaction mixture; refining the reaction mixture to obtain 4-aminodiphenylamine. The complex base catalyst comprises tetraalkyl ammonium hydroxide, and tetraalkyl ammonium salt.

Abstract: A process for preparing 4-aminodiphenylamine using nitrobenzene and aniline as raw materials, a complex base catalyst as the condensation catalyst, and a powdery composite catalyst as the hydrogenation catalyst. The process has 5 process stages including condensation, hydrogenation, separation I, separation II, and refining.

Abstract: A process for preparing 4-aminodiphenylamine using nitrobenzene and aniline as raw materials, a complex base catalyst as the condensation catalyst, and a powdery composite catalyst as the hydrogenation catalyst. The process has 5 process stages including condensation, hydrogenation, separation I, separation II, and refining.

Abstract: The present invention discloses a process for preparing 4-aminodiphenylamine, which process uses nitrobenzene and aniline as raw materials, a complex base catalyst as condensation catalyst and a powdery composite catalyst as hydrogenation catalyst, and comprises five process stages: condensation; separation I; hydrogenation; separation II; and refining. The process can be continuously carried out. By selecting a complex base catalyst to catalyze the condensation reaction and separating it prior to the hydrogenation, the problem that the complex base catalysts thermally decompose in the hydrogenation reaction is avoided, the selectable range of hydrogenation catalysts is largely enlarged so that it is possible to select cheaper hydrogenation catalyst, and the selection of production process and equipment is easier and further industrialization is easier. The complex base catalysts used in the present invention are inexpensive and have higher catalytic activity.