Patents Assigned to Sinorgchem Company, Shandong
  • Patent number: 7176333
    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.
    Type: Grant
    Filed: July 2, 2004
    Date of Patent: February 13, 2007
    Assignee: Sinorgchem Company, Shandong
    Inventors: Nongyue Wang, Ruibiao Yu, Xiaohui Mao, Xiaogen Feng, Qianwen Cheng