摘要:
A novel process for the preparation, for example of gelatino silver chloride and silver bromochloride grains with modified tabular crystal habit is described. These grains are prepared using standard single jet (SJ) or balanced double jet (BDJ) techniques, said preparation occurring in the presence of a modifying amount of an aminoazapyridine as defined and a suitable binder to form well-developed, sensitive tabular elements with a median grain volume in the range of 0.005 to 0.50 .mu.m.sup.3.
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.
摘要:
Process for preparing photographic emulsion comprising bringing aqueous silver and chloride-containing halide salt solutions into contact in the presence of a dispersing medium to form octahedral silver halide grains having a halide content of at least 50 mole percent chloride, based on total moles of silver present, the improvement forming the grains in the presence of a crystal modifying amount of an aminoazapyridine as described in pH range of 2.5 to 9, pCl range of 0 to 3, the aminoazapyridine compound being added after at least about 6% to about 45% of the silver salt solution has been added.The photographic emulsion is useful in x-ray, laser scanner films, as color separation elements and inverse transfer systems, etc.