Patents by Inventor Hansjorg Buser

Hansjorg Buser 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).

  • Process for the preparation of a solid adduct of sulfuric acid and urea
    Patent number: 4879413
    Abstract: A method for processing exposed and developed photographic silver dye-bleach materials, in which the exposed and developed material is treated with aqueous bleaching preparations which contain (a) an acid component, (b) a silver complexing agent, (c) one or more bleach catalysts, (d) optionally an antioxidant, (e) optionally a water-soluble oxidizing agent and (f) optionally a bleaching accelerator.A water-soluble and as a rule solid adduct of an acid amide or a lactam and a strong mineral acid is used as acid component (a).
    Type: Grant
    Filed: September 12, 1988
    Date of Patent: November 7, 1989
    Assignee: Ciba-Geigy AG
    Inventors: Hansjorg Buser, Adolf Morand
  • Method for processing photographic silver dye-bleach materials and suitable preparations
    Patent number: 4366232
    Abstract: A method for processing exposed and developed photographic silver dye-bleach materials, in which the exposed and developed material is treated with aqueous bleaching preparations which contain (a) an acid component, (b) a silver complexing agent, (c) one or more bleach catalysts, (d) optionally an antioxidant, (e) optionally a water-soluble oxidizing agent and (f) optionally a bleaching accelerator.A water-soluble and as a rule solid adduct of an acid amide or a lactam and a strong mineral acid is used as acid component (a).
    Type: Grant
    Filed: February 17, 1981
    Date of Patent: December 28, 1982
    Assignee: Ciba-Geigy Ltd.
    Inventors: Hansjorg Buser, Adolf Morand