Patents by Inventor Clemens Linden

Clemens Linden 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).

  • Patent number: 4185023
    Abstract: A process for the manufacture of anthraquinone, in which o-benzyl-toluene is oxidized with air or an oxygen-containing gas in an acetic acid solution in the presence of cobalt, manganese and bromine salts as catalysts, to which solution sufficient acetic anhydride is added to bind the reaction water, thereby keeping the acid concentration constant. The crude o-benzoyl-benzoic acid is then esterified with methanol, the methyl ester distilled from the reaction mixture and heated with concentrated sulfuric acid to yield anthraquinone in good yield and of a high degree of purity.
    Type: Grant
    Filed: February 1, 1979
    Date of Patent: January 22, 1980
    Assignee: Bergwerksverband GmbH
    Inventors: Kurt Handrick, Georg Kolling, Clemens Linden, Gunter Droll, Jr.
  • Patent number: 4185024
    Abstract: A process for the manufacture of anthraquinones in which o-benzyl-toluene is first oxidized with 25 to 50 weight-% nitric acid at atmospheric pressure and moderate temperatures, and then further oxidized with a more dilute nitric acid at elevated temperatures and pressures to yield crude o-benzoyl-benzoic acid. The crude product is then esterified with methanol, the methyl ester distilled and, when necessary, recrystallized, and heated with concentrated sulfuric acid to yield anthraquinone in high yield and of a high degree of purity.
    Type: Grant
    Filed: February 1, 1979
    Date of Patent: January 22, 1980
    Assignee: Bergwerksverband GmbH
    Inventors: Kurt Handrick, Georg Kolling, Clemens Linden