Process for the preparation of silver halide emulsions

摘要

A silver halide emulsion is made by continuous conversion of a more soluble silver halide into a less soluble silver halide. From a first part of up to 50% of the total amount of silver nitrate by reaction with a first water soluble halide a silver halide is precipitated consisting at least partly of a more readily soluble silver halide, e.g. silver chloride. In the presence of this more readily soluble silver halide the remaining silver nitrate is reacted with a second water soluble halide composition to form the residual silver halide (main precipitation). The amount of total halide in the precipitation is slightly more than equivalent to the amount of silver ions. However the amount of halide that forms the less readily soluble silver halide is less by at least 5 mol% than equivalent to the amount of silver ions in the precipitation medium.