Process for preparing silver halide emulsions

摘要

Improved process for preparing silver chlorobromide or silver chloroiodobromide emulsion wherein first silver ion solution and second halide ion solution are mixed by double jet method and mole % of silver bromide, silver chloride and silver iodide are in specified range, characterized in that molar ratio of Br-:Cl-:I- in second solution is within specified range and further step is included to produce silver halide with control of silver ion concentration by using third solution containing Br- and Cl-. Such emulsions have sufficiently narrow grain diameter distribution and silver halide composition distribution, with constant productivity.