Process for the stabilization of high-chloride crystals with modified crystal habit using bromide shells

摘要

Process for stabilizing the crystalline grain morphology of silver halide grain cores prepared in the presence of a dispersing medium and an aminoazapyridine compound at a pH of 2.5 to 9 and pCl of 0 to 3, at least 50% of the total projected area of the total grain population being noncubic silver halide grain cores and the halide content being at least 50 mole percent chloride, based on total moles of silver precipitated, the improvement wherein after 60% of aqueous silver salt solution based on the total moles of silver precipitated is introduced a second halide salt, e.g., bromide, is added thereby forming on the grain cores a shell of 0.5 to 20 mole % based on the total moles of silver precipitated. The emulsions are useful in X-ray, color separation, inverse transfer films, and "dry-silver" applications, etc.