Patents by Inventor Peter Donath

Peter Donath 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: 4171300
    Abstract: A process for the manufacture of metal complex dyes, wherein a metallisable dye is reacted with a metal compound in a solvent and in the presence of a hydroxycarboxylate.
    Type: Grant
    Filed: April 3, 1978
    Date of Patent: October 16, 1979
    Assignee: Ciba-Geigy AG
    Inventors: Peter Donath, Gerhard Back
  • Patent number: 4085097
    Abstract: A process is described for the manufacture of chromium complexes of metallizable dyes in the form of solid dyestuff powders of low salt to salt-free content, or of concentrated solutions of low salt or salt-free content in which a metallizable dye, or a mixture of metallizable dyes, in an organic solvent which is immiscible or sparingly miscible with water, or reacted with a chromium compound, in the course of which any water which is liberated is removed by azeotropic distillation, and the resulting chromium complex, provided it is a 1:1 complex, is then optionally reacted in the presence of a base with a further mol of a metallizable dye, or of a colorless, complexforming compound, then isolated from undissolved constituents, and the resulting dye solution of low salt or salt-free content is optionally concentrated or evaporated to dryness, whereby it is possible the manufacture of 1:1 or 1:2 chromium complexes without the handicap of effluent pollution, and to isolate the dyes without using salt.
    Type: Grant
    Filed: January 7, 1976
    Date of Patent: April 18, 1978
    Assignee: Ciba-Geigy AG
    Inventors: Fabio Beffa, Arthur Buhler, Peter Donath, Hans Ulrich Schutz, Gerhard Back