Photographic silver halide material containing 2-equivalent yellow couplers
AssigneeAgfa-Gevaert
InventorsImmo Boie, Dieter Lowski
Life of this patent
Estimating the term…
Abstract
Desirable 2-equivalent yellow couplers carry at the coupling position a monocyclic pyrrole, diazole or triazole ring attached to the coupling position of the yellow coupler by a nitrogen atom, which ring can be split off in the coupling reaction. Photographic 2-equivalent yellow couplers with nitrogen-containing heterocyclic splittable groups having such nitrogen bonded to the coupling position of the couplers, are prepared by reacting a corresponding 2-equivalent yellow coupler containing a halogen such as chlorine in the coupling position with the nitrogen-containing heterocyclic compound that supplies the splittable group, in the presence of base and in the further presence of hexamethylphosphoric acid triamide as solvent.
Claims4
In a light sensitive color photographic material containing at least one silver halide emulsion layer and a 2-equivalent yellow coupler having an activated open-chain ketomethylene coupler structure in which one hydrogen of the methylene group is substituted by a nitrogen of a heterocyclic group which group is photographically relatively inert except that it is split off during chromogenic development, the improvement according to which the splittable group is a monocyclic pyrrole, 1,2-diazole, 1,3-diazole or 1,2,3-triazole group attached to the coupling position of the yellow coupler.
Dependencies are inferred from the claim text.