Patent ID: 6524782
Filing Date: 2003-02-25
Classification: G03C

Abstract:
A method of preparing a silver halide emulsion, wherein said silver halide emulsion comprises tabular grains exhibiting a mean equivalent circle diameter of 0.1 to 10.0 &mgr;m, a mean grain thickness of 0.01 to 0.3 &mgr;m and an aspect ratio of 1.5 to 300, the method comprising:(a) reacting a silver salt solution and a halide salt solution to perform silver halide grain nucleation, followed by silver halide grain growth to form the tabular grains, wherein the tabular grains are formed in the presence of fine silver halide grains containing at least one selected from the group of gallium, indium and metals in Groups 8, 9 and 10 of the periodical table; and (b) removing a solution containing soluble salts from a reaction mixture solution by ultrafiltration during the silver halide grain growth to reduce the volume of the reaction mixture solution in a reaction vessel; wherein in (b), the volume of the reaction mixture solution is so controlled that a mean intergrain distance as defined below in the reaction mixture solution in the reaction vessel is maintained within not less than 0.60 and not more than 1.15 times that at the start of the grain growth over a period of from start of growing silver halide grains to completion thereof: mean intergrain distance=(Volume of the reaction mixture solution/number of grains in the reaction mixture solution)1/3.