Patents Assigned to Duslo, A.S. Sala
  • Method of preparation of 4-aminodiphenylamine
    Patent number: 6388136
    Abstract: A method of preparing 4-aminodiphylamine through an intermediate preparation of 4-nitrodiphenylamine and/or 4-nitrosodiphenylamine and/or their salts by reaction of aniline with nitobenzene in a liquid medium at a temperature of 50 to 130° C., under normal or reduced pressure, in an inert atmosphere or in the presence of air oxygen, with subsequent hydrogenation of an intermediate of 4-nitrodiphenylamine and/or nitrosodiphenylamine and side products, and by isolation of 4-aminodiphenylamine and the side products of unconverted raw materials.
    Type: Grant
    Filed: June 8, 2001
    Date of Patent: May 14, 2002
    Assignee: Duslo, A.S. Sala
    Inventors: Emanuel Be{haeck over (s)}ka, Peter Toman, Karol Fiedler, Milan Hronec, Jozef Pint{dot over (e)}r