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(11) | EP 0 670 515 A3 |
| (12) | EUROPEAN PATENT APPLICATION |
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| (54) | Process for the preparation of silver halide emulsion |
| (57) A process for the preparation of a silver halide emulsion comprising silver halide
grains dispersed in a dispersing medium. The process comprises the steps of (1) forming
host silver halide nuclei in the dispersing medium, (2) adding a halide solution to
the silver halide nuclei to form a crystal defect which gives rise the formation of
tabular grain, by forming at least one gap interface of halide composition in the
nuclei by a halogen conversion reaction and (3) growing silver halide grains preferentially
along the direction of edges of the grains to form tabular grains having an aspect
ratio (diameter per thickness) of not less than 1.5 and {100} major faces. A difference
in chloride content or bromide content between the halide composition of the host
silver halide nuclei and the halide composition of the halide solution is in the range
of 10 to 100 mol % or a difference in iodide content between the halide composition
of the host silver halide nuclei and the halide composition of the halide solution
is in the range of 5 to 100 mol %. |