Silver halide elements containing blocked pyrazolone magenta dye-forming couplers
AssigneeEastman Kodak Company
InventorsThomas E. Gompf, Howell A. Hammond, Jared B. Mooberry
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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.
Claims18
A photographic element comprising a support and a photosensitive silver halide emulsion having associated therewith a nondiffusible magenta dye-forming coupler having the structure:
- ##STR22## wherein:
- Q represents the atoms to complete a 5-pyrazolone magenta dye-forming coupler moiety;
- n is 1 or 2;
- R is a ballast group when n is 1 or a divalent organic group when n is 2;
- R.sup.1 is hydrogen or a coupling-off group;
- and
- Cp is a coupler moiety which upon reaction by means of oxidized color developing agent yields a colorless or alkali soluble reaction product and is attached at its coupling position to the enol oxygen of the pyrazolone coupler moiety.
A photographic silver halide emulsion containing a nondiffusible magenta dye-forming coupler having the structure:
- ##STR26## wherein:
- Q represents the atoms to complete a 5-pyrazolone magenta dye-forming coupler moiety;
- n is 1 or 2;
- R is a ballast group when n is 1 or a divalent organic group when n is 2;
- R.sup.1 is hydrogen or a coupling-off group;
- and
- Cp is a coupler moiety which upon reaction by means of oxidized color developing agent yields a colorless or alkali soluble reaction product and is attached at its coupling position to the enol oxygen of the pyrazolone coupler moiety.
A process of forming a magenta dye image in a photographic element comprising a support and a silver halide emulsion, comprising the step of developing the element with a silver halide color developing agent in the presence of a nondiffusible magenta dye-forming coupler having the structure:
- ##STR29## wherein:
- Q represents the atoms to complete a 5-pyrazolone magenta dye-forming coupler moiety;
- n is 1 or 2;
- R is a ballast group when n is 1 or a divalent organic group when n is 2;
- R.sup.1 is hydrogen or a coupling-off group;
- and
- Cp is a coupler moiety which upon reaction by means of oxidized color developing agent yields a colorless or alkali soluble reaction product and is attached at its coupling position to the enol oxygen of the pyrazolone coupler moiety.
A processed photographic element containing a magenta dye image comprised of a magenta dye obtained by coupling of oxidized silver halide color developing agent and a nondiffusible magenta dye-forming coupler having the structure:
- ##STR30## wherein:
- Q represents the atoms to complete a 5-pyrazolone magenta dye-forming coupler moiety;
- n is 1 or 2;
- R is a ballast group when n is 1 or a divalent organic group when n is 2;
- R.sup.1 is hydrogen or a coupling-off group;
- and
- Cp is a coupler moiety which upon reaction by means of oxidized color developing agent yields a colorless or alkali soluble reaction product and is attached at its coupling position to the enol oxygen of the pyrazolone coupler moiety;
- there remaining in areas where magenta dye has not been formed, the blocked magenta dye forming coupler.
Dependencies are inferred from the claim text.