Patents by Inventor Karol Fiedler

Karol Fiedler has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • 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
  • Method of preparation of 4-aminodiphenylamine
    Publication number: 20020045779
    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.
    Type: Application
    Filed: June 8, 2001
    Publication date: April 18, 2002
    Inventors: Emanuel Beska, Peter Toman, Karol Fiedler, Milan Hronec, Jozef Pinter