| 摘要 |
PURPOSE:To rapidly form an image high in contrast with high sensitivity by fogging the surface of the core of each silver halide grain with a reducing agent and simultaneously adding an aqueous solution of a halide and an aqueous solution of a silver compound to prepare an internally fogged core/shell type silver halide emulsion contacting a specified compound. CONSTITUTION:The internally fogged core/shell type silver halide emulsion is prepared by fogging the surface of the core of each silver halide grain with a reducing agent, preferably, in an amount of 1X10<-4>-5mmol per mol of silver halide in the core, preferably, in a pH of 6.5-10.0, and then, adding an aqueous solution of a halide and an aqueous solution of a silver compound at the same time. Said emulsion contains the compound represented by the formula shown on the right in which X is S or =N-R<4>; and each of R<1>-R<4> is alkyl, aryl, or a heterocyclic group each optionally substituted. |
