Photographic silver halide emulsions

Claim 1

A METHOD OF PREPARING A LIGHT-SENSITIVE PHOTOGRAPHIC EMULSION IN THE FORM OF A THERMALREVERSIBLE GEL, SUITABLE FOR SENSITIZING PHOTOGRAPHIC MATERIALS AND ADAPTED TO FORM A FILM OF TOUGH, TRANSPARENT COLLOID HAVING A LIGHT-SENSITIVE SILVER HALIDE DISPERSED THEREIN, WHICH CONSISTS IN PREPARING A DISPERSION OF A LIGHT-SENSITIVE SILVER HALIDE IN AN AQUEOUS SOLUTION OF A POLYVINYL ALCOHOL WHICH CONTAINS, AS THE SOLE GELLING AGENT THEREFOR, A GELLING AMOUNT FROM ABOUT 1% TO ABOUT 20% BY WEIGHT OF THE AMOUNT OF POLYVINYL ALCOHOL, OF A WATER-SOLUBLE NITROGENOUS COMPOUND SELECTED FROM THE GROUP CONSISTING OF PROTEINS, PROTEIN DEGRATION PRODUCTS, ALPHA-AMINO ACIDS AND THEIR CONDENSATION PRODUCTS, EVAPORATING THE RESULTING DISPERSION TO DRYNESS AND SWELLING THE DRIED COMPOSITION THUS OBTAINED IN COLD WATER, WHEREBY THE PRODUCT IS CONVERTED TO A GEL AND ANY WATER-SOLUBLE SALTS CONTAINED THEREIN ARE WASHED OUT.

Claim 2

A METHOD OF PREPARING A LIGHT-SENSITIVE PHOTOGRAPHIC EMULSION IN THE FORM OF A THERMALREVERSIBLE GEL, SUITABLE FOR SENSITIZING PHOTOGRAPHIC MATERIALS AND ADAPTED TO FORM A FILM OF TOUGH, TRANSPARENT COLLOID HAVING A LIGHT-SENSITIVE SILVER HALIDE DISPERSED THEREIN, WHICH CONSISTS IN PREPARING A DISPERSION OF A LIGHT-SENSITIVE SILVER HALIDE IN AN AQUEOUS SOLUTION OF A POLYVINYL ALCOHOL WHICH CONTAINS, AS THE SOLE GELLING AGENT THEREFOR, A GELLING AMOUNT FROM ABOUT 1% TO ABOUT 20% BY WEIGHT OF THE AMOUNT OF POLYVINYL ALCOHOL, OF A WATER-SOLUBLE NITROGENOUS COMPOUND SELECTED FROM THE GROUP CONSISTING OF PROTEINS, PROTEIN DEGRATION PRODUCTS, ALPHA-AMINO ACIDS AND THEIR CONDENSATION PRODUCTS, EVAPORATING THE RESULTING DISPERSION TO DRYNESS AND SWELLING THE DRIED COMPOSITION THUS OBTAINED IN COLD WATER, WHEREBY THE PRODUCT IS CONVERTED TO A GEL AND ANY WATER-SOLUBLE SALTS CONTAINED THEREIN ARE WASHED OUT.