Polaroid Corporation

Martin L Falxa

Richard S Himmelwright

Leo D Corben

Kenneth J Meara

A method for preparing a narrow-grain size distribution silver iodobromide emulsion which comprises precipitating silver iodobromide grains by simultaneously introducing an ammoniacal solution of silver nitrate and a solution of ammonium bromide into an ammoniacal solution consisting essentially of gelatin and a water-soluble iodide salt under conditions where silver ions are not in excess during said precipitation.

Method for preparing photosensitive silver halide emulsions

Photosensitive silver halide grains are disclosed comprising a shell of silver halide substantially surrounding a water-soluble, non-silver containing grain as a core. Methods for forming silver halide grains having a water-soluble, non-silver containing core are also disclosed.

Photosensitive silver halide emulsion

Monodisperse, negative working photosensitive silver halide emulsions comprising grains having a uniform habit and relatively high degree of crystal disorder are prepared by precipitating silver halide in the presence of a seed emulsion which is predominantly silver chloride under conditions whereby substantially none of the silver chloride of said seed emulsion is redissolved and substantially no additional grains are formed.

Novel photosensitive silver halide emulsion and method of preparing same

The present invention is directed to a method for preparing a photosensitive silver halide emulsion comprising silver halide grains prepared by simultaneously introducing a solution of ammoniacal silver nitrate and a solution of an ammonium halide into a solution of gelatin and a second ammonium halide. The invention is also directed to photographic elements employing such silver halide emulsions.

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Cambridge, MA, United States of America

Martin L Falxa