Sterically hindered phenolic ester photographic coupler dispersion addenda and photographic elements employing same
AssigneeEastman Kodak Company
InventorSundaram Krishnamurthy
Life of this patent
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Abstract
Photographic coupler dispersion addenda comprising phenolic esters of di-, tri- and tetra-carboxybenzene derivatives having bulky ortho substituents are described for incorporation in photographic emulsions and elements. The solvents are preferably employed in the cyan layer to protect the cyan dye against ferrous ion reduction. The solvents also provide improvements in yellow dye stability to light and cyan dye stability to light, heat and humidity.
Claims9
A photographic element comprising a support having thereon at least one silver halide emulsion layer having associated therewith a dye-forming coupler dispersed in a coupler solvent therefor together with a dispersion addendum having the formula:
- ##STR26## wherein A is CH or N;
- each X.sup.1, X.sup.2 and X.sup.3 can independently be --H, halogen, --R, --CH.dbd.NOR, --COR, --SO.sub.2 R, --YR, --YCOR, --COYR, --YSO.sub.2 R or --SO.sub.2 YR, wherein Y is O, S or NR' and R' is H or R;
- or two X groups can join together to form a heterocyclic ring;
- R can be a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group or a substituted or unsubstituted heterocyclic group;
- n is 2, 3 or 4 and
- each m is 1, 2 or 3;
- with the proviso that at least one pair of X.sup.1 and X.sup.2 substituents attached to the same benzene ring must contain a total of two or more non-hydrogen atoms, and with the further proviso that only one of X.sup.1, X.sup.2 and X.sup.3 substituents attached to the same benzene ring may be hydrogen.
Dependencies are inferred from the claim text.