Process for the preparation of a grain stabilized high chloride tabular grain photographic emulsion (II)

A process of preparing an emulsion for photographic use comprising

• (1) forming an emulsion comprised of silver halide grains and a gelatino-peptizer dispersing medium in which morphologically unstable tabular grains having {111} major faces account for greater than 50 percent of total grain projected area and contain at least 50 mole percent chloride, based on silver, the emulsion additionally containing at least one grain growth modifier adsorbed to an morphologically stabilizing the tabular grains, and
• (2) adsorbing to surfaces of the tabular grains a photographically useful compound,
• CHARACTERIZED IN THAT
• the emulsion is formed in the presence of a stoichiometric excess of chloride ion having a chloride ion concentration of less than 0.5M, the morphological stabilizer being in an amount sufficient to provide a monomolecular layer adsorbed to at least 25 percent of the surface area of the emulsion grains,
• the grain growth modifier is a xanthinoid which satisfies the formula:
• ##STR13## where Z.sup.8 is --C(R.sup.8).dbd. or --N.dbd.;
• R.sup.8 is H, NH.sub.2 or CH.sub.3 ;
• and
• R.sup.1 is hydrogen or a hydrocarbon containing from 1 to 7 carbon atoms;
• the pH of the dispersing medium is reduced below 3.0 to inactivate xanthinoid as a morphological stabilizer, and
• the inactivated xanthinoid is replaced on the tabular grain surfaces by adsorption of the photographically useful compound, the photographically useful compound being selected from among those containing at least one divalent sulfur atom, thereby concurrently morphologically stabilizing the tabular grains and enhancing their photographic utility.