Silver halide precipitation process with deletion of materials through the reaction vessel

Abstract

An improved silver halide precipitation process of preparing a dispersion of silver halide grains is disclosed. The process comprises forming a radiation-sensitive silver halide dispersion by reacting silver and halide salts in solution within a dispersing medium to form silver halide grain nuclei within the dispersing medium and allowing silver halide grain growth to occur in a reaction vessel in which the silver halide grain nuclei and the dispersing medium are present. The improvement comprises, during silver halide grain growth, withdrawing a portion of the dispersing medium from the reaction vessel through an ultrafiltration membrane while retaining the silver halide grains within the dispersing medium remaining within the reaction vessel.

Dependencies are inferred from the claim text.