Abstract: Thermally developable materials such as thermographic and photo-thermographic materials include a co-precipitate comprising first and second organic silver salts, the first organic silver salt comprising a silver salt of a nitrogen-containing heterocyclic compound containing an imino group, and the second organic silver salt comprising a silver salt of a mercaptotriazole. The first organic silver salt can be used in the imaging process as a source of reducible silver ions, and the second organic silver salt can be a source of a toning agent. The co-precipitate can be prepared using double-jet precipitation techniques to provide an aqueous dispersion that can be used in imaging formulations.

Abstract: Thermally developable materials such as thermographic and photo-thermographic materials include a novel non-photosensitive source of reducible silver ions that are predominantly provided as rod-shaped particles of silver salt of a nitrogen-containing heterocyclic compound containing an imino group. The rod-shaped particles have an average aspect ratio of at least 3:1 and a width index for particle diameter of 1.25 or less, and provide improved imaging properties. These particles can be prepared using double jet precipitation procedures in which vAg is kept constant at a value of equal to or greater than ?50 mV.

Abstract: A process for the preparation of a radiation-sensitive silver halide emulsion comprised of high bromide cubical silver halide grains, the process comprising: (a) providing in a stirred reaction vessel a dispersing medium and high bromide silver halide grain cores, the grain cores comprising at least 5 mole % of the final emulsion silver and the contents of the vessel being maintained at a temperature of at least about 65° C., and (b) precipitating a high bromide silver halide shell which comprises at least 5 mole % of the final emulsion silver onto the grain cores by introducing at least a silver salt solution into the dispersing medium at a specified high rate, wherein a minor percentage of chloride ions, relative to bromide, is introduced into the reaction vessel prior to or concurrent with precipitation of the high bromide shell, and wherein the concentration of silver halide grains in the reaction vessel at the end of the precipitation of the shell is at least 0.5 mole/L.