Radiation sensitive thermally developable imaging elements comprise: a) photosensitive silver halide, b) light insensitive silver salt oxidizing agent, c) reducing agent for silver ions, and d) an antifoggant or speed enhancing compound comprising hydrobromic acid salts of nitrogen-containing heterocyclic ring compounds which are further associated with a pair of bromine atoms. The antifoggants are effective in reducing spurious background image densities.

A production process for a photothermographic recording material thermally developable under substantially water-free conditions comprising the steps of: (i) providing a support; (ii) producing one or more aqueous dispersions or solutions containing together a substantially light-insensitive organic silver salt, photosensitive ex-situ silver halide in catalytic association with the substantially light-insensitive organic silver salt, a reducing agent in thermal working relationship with the substantially light-insensitive organic silver salt and a binder; (iii) coating the one or more aqueous dispersions or solutions onto the support to form layers which upon drying become a photo-addressable thermally developable element; and (iv) drying the layers, wherein the photo-addressable thermally developable element contains between 0.2 and 2.5 moles of in-situ photosensitive silver iodide per mole of ex-situ photosensitive silver halide produced by reacting particles of the substantially light-insensitive organic silver salt in an aqueous dispersion with a source of iodide ion; and a recording process therefor.

Radiation sensitive thermally developable imaging elements comprise: (a) photosensitive silver halide, (b) light insensitive silver salt oxidizing agent, (c) reducing agent for silver ions, and (d) an antifoggant or speed enhancing compound comprising iodophthalazinone compounds. The antifoggants are effective in reducing spurious background image densities.

A process for producing a suspension of particles containing a substantially light-insensitive organic silver salt of an organic carboxylic acid, comprising simultaneous metered addition of an aqueous solution or suspension of an organic carboxylic acid or its salt; and an aqueous solution of a silver salt to an aqueous liquid, wherein the metered addition of the aqueous solution or suspension of the organic carboxylic acid or its salt; and/or the aqueous solution of the silver salt is regulated by the concentration of silver ions or the concentration of anions of the silver salt in the aqueous liquid; for use in the production of (photo)thermographic materials.

A dry process silver salt photosensitive material has a support and provided thereon a photosensitive layer containing at least an organic silver salt, a reducing agent and a photosensitive silver halide or a photosensitive silver halide forming component. The photosensitive layer is incorporated with a compound selected from the compounds (i), (ii) and (iii).