Patent ID: 6228573
Filing Date: 2001-05-08
Classification: G03C

Abstract:
A process for preparing an ultrathin high bromide {111} tabular grain silver halide emulsion in a reaction vessel comprising the steps of(a) forming in the presence of a dispersing medium a population of silver halide grain nuclei containing twin planes, and(b) growing the silver halide grain nuclei containing twin planes in the reaction vessel to form high bromide {111} tabular silver halide grains by the addition of silver and halide ions to the reaction vessel, WHEREIN the majority of the silver added to the reaction vessel during growth step (b) is added at a pBr of less than 2.6 and in the presence of a triaminopyrimidine grain growth modifier containing mutually independent 4, 5 and 6 ring position amino substituents, the 4 and 6 ring position substituents being hydroamino substituents.