| 摘要 |
PURPOSE:To enhance sensitivity and to improve graininess sharpness by incorporating a core/shell type silver halide obtained by reacting a water-soluble silver salt soln. with a water-soluble halide soln. in the presence of a silver halide solvent and growing the obtained seed crystals to a specified range of grain diameter. CONSTITUTION:A water-soluble silver salt soln. is reacted with a water-soluble halide soln. in the presence of a silver halide (AgX) solvent and the obtained AgX seed crystals are grown, and the obtained core/shell type AgX having <=0.5m average grain diameter is incorporated in an emulsion. The core/shell type emulsion obtained by growing the AgX seed crystals in an AgX solvent is extremely high in sensitizing effect. As the grain diameter ratio of emulsion grains to seed crystals, a ratio of >= about 1.1:1 is found to be effective, and the upper limit of the growth ratio is about 10:1. Such an emulsion is good in graininess and sharpness, and yet, restrains occurrence of fog, and enhances sensitivity extremely. |
