Patents by Inventor Bernard Arthur J. Clark

Bernard Arthur J. Clark 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: 5350667
    Abstract: A photographic element contains a light-sensitive silver halide layer having associated therewith a coupler which is a pyrazolone compound with a coupling-off substituent at the -4-position, said compound having the formula: ##STR1## wherein each R.sup.1 is independently a substituted or unsubstituted alkylsulfonyl or arylsulfonyl group; each R.sup.2 and R.sup.3 is independently a substituent; R.sup.4, R.sup.5, and R.sup.6 are independently hydrogen or substituted or unsubstituted alkyl groups; m and n are independently 0 or 1 but both are not 0; x1 and x2 are independently 0 to 5; and y is 0 to 3; provided that each of R.sup.3, R.sup.4, R.sup.5, and R.sup.6 is selected such that the calculated log P of the thiophenol corresponding to the substituent at the 4-position of the pyrazolone is at least 4. The photographic element provides an improved combination of low continued coupling together with a magenta hue exhibiting a long wavelength of maximum absorption.
    Type: Grant
    Filed: June 17, 1993
    Date of Patent: September 27, 1994
    Assignee: Eastman Kodak Company
    Inventors: Stephen P. Singer, Paul B. Merkel, Bernard Arthur J. Clark, Paul Louis R. Stanley