Silver halide emulsion and silver halide light sensitive photographic material
AssigneeKonica Corporation
InventorsTomoyuki Nakayama, Tadahiro Nagasawa, Rieko Ren
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Abstract
A silver halide emulsion comprising silver halide grains is disclosed, in which at least 50% of total grain projected area is accounted for by silver halide regular crystal grains exhibiting a proportion of a (100) face per grain of not less than 50% and having an average iodide content of not more than 5 mol %; the silver halide grains having an internal high iodide phase having an average iodide content of not less than 7 mol % and accounting for 0.1 to 15% of the grain volume; the high iodide phase being in the region at a depth of from 7 to 27% from the (100) face, based on the distance between the center of a grain and the (100) face.
Claims13
A silver halide emulsion comprising silver halide grains, wherein at least 50% of total grain projected area is accounted for by silver halide regular crystal grains exhibiting a proportion of a (100) face per grain of 70% to 95% and having an average iodide content of not more than 5 mol %;
- said silver halide grains having an internal high iodide phase having an average iodide content of not less than 7 mol % and accounting for 0.1 to 15% of the grain volume and an outermost surface layer having an iodide content of not more than 10 mol %;
- said high iodide phase being in the region at a depth of from 7 to 27% from the (100) face, based on the distance between the center of a grain and the (100) face.
A method of preparing a silver halide emulsion comprising silver halide regular grains exhibiting a proportion of a (100) face per grain of 70% to 95% accounting for at least 50% of total grain projected area and having an average iodide content of not more than 5 mol %, the silver halide grains having an internal high iodide phase having an average iodide content of not less than 7 mol % and accounting for 0.1 to 15% of the grain volume and an outermost surface layer having an iodide content of not more than 10 mol %, the method comprising:
- (i) forming nuclear grains by adding a silver salt and a halide salt to a mother liquor,
- (ii) ripening the nuclear grains, and
- (iii) growing the nuclear grains to form final grains by adding a silver salt and a halide salt, wherein in (iii), fine silver iodide grains, an aqueous soluble iodide salt or an iodide ion releasing compound is added at a time after adding of 40% of the silver salt to be added and before adding of 80% of the silver salt to be added.
Dependencies are inferred from the claim text.