Patents Represented by Attorney Thomas H. Kirchoff

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  • Silver halide photosensitive materials containing thiourea and analogue derivatives
    Patent number: 4749646
    Abstract: A photographic silver halide emulsion comprising a 1,1,3,3-tetrasubstituted middle chalcogen urea compound is described wherein at least one substituent comprises an acid function. The urea compound is an effective silver halide grain growth-modifying agent. A process for modifying the grain growth of silver halide is also described.
    Type: Grant
    Filed: March 23, 1987
    Date of Patent: June 7, 1988
    Assignee: Eastman Kodak Company
    Inventors: Arthur H. Herz, George J. Burgmaier