Patents by Inventor Howell A. Hammond

Howell A. Hammond 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).

  • Silver halide elements containing blocked pyrazolone magenta dye-forming couplers
    Patent number: 4283472
    Abstract: Novel 5-pyrazolone magenta dye-forming couplers are blocked with a coupler moiety which yields an alkali-soluble or colorless reaction product. The coupler moiety is joined via its coupling position to the enol oxygen of the 5-pyrazolone and is displaced therefrom during processing as a result of reaction by means of oxidized color developing agent to thereby activate the 5-pyrazolone coupler. These couplers have good reactivity and good resistance to aerial contaminants, such a formaldehyde, and can be incorporated in photographic emulsions and elements.
    Type: Grant
    Filed: February 26, 1980
    Date of Patent: August 11, 1981
    Assignee: Eastman Kodak Company
    Inventors: Thomas E. Gompf, Howell A. Hammond, Jared B. Mooberry
  • Blocked pyrazolone magenta dye-forming couplers
    Patent number: T101004
    Abstract: Novel 5-pyrazolone magenta dye-forming couplers are blocked with a coupler moiety which yields an alkali-soluble or colorless reaction product. The coupler moiety is joined via its coupling position to the enol oxygen of the 5-pyrazolone and is displaced therefrom during processing as a result of reaction by means of oxidized color developing agent to thereby activate the 5-pyrazolone coupler. These couplers have good reactivity and good resistance to aerial contaminants, such as formaldehyde, and can be incorporated in photographic emulsions and elements.
    Type: Grant
    Filed: December 29, 1980
    Date of Patent: September 1, 1981
    Inventors: Thomas E. Gompf, Howell A. Hammond, Jared B. Mooberry