Eastman-Kodak Company

John W Reeves

Edward L Dedio

A method of making a photothermographic silver halide element comprises the combination of (I) adding an alkyl carboxylic acid containing 8 to 22 carbon atoms to a layer of the element comprising photosensitive silver halide and (II) after preparation of the layer comprising silver halide and before exposure of the element to light heating the element uniformly at a temperature and for a time sufficient to enable the photothermographic element to exhibit increased latent image stability upon imagewise exposure to light. The photothermographic element includes photosensitive silver halide and an oxidation-reduction image forming combination in a polmeric binder. A developed visible image is provided in such a photothermographic element after exposure to light by uniformly heating the exposed photothermographic element to moderately elevated temperatures.

Photothermographic element and process

Photosensitive silver halide grains that are thin tabular grains having an average grain thickness of less than 0.3 microns provide advantages, including improved spectral sensitization and image tone, in a photothermographic material comprising photosensitive silver halide and a photosensitive silver halide processing agent. An image is developed in such an exposed photothermographic material by heating the material, such as to a temperature within the range of about 90.degree. C. to about 180.degree. C.

Photothermographic silver halide material and process

In a photothermographic silver halide composition capable of being coated on a support comprising a hydrophilic photosensitive silver halide emulsion containing a gelatino peptizer with an organic solvent mixture, a hydrophobic binder and an oxidation-reduction image-forming composition comprising (i) a silver salt of a long-chain fatty acid with (ii) an organic reducing agent, improvements are provided by a solvent mixture comprising a combination of (A) an alcohol photographic speed-increasing solvent which is a compound selected from the group consisting of benzyl alcohol photographic speed-increasing solvents and 2-phenoxyethanol speed-increasing solvents with (B) an aromatic hydrocarbon solvent that is compatible with the alcohol solvent and (C) 0 to 10% by weight of the solvent mixture of such hydrophobic binder. The described photothermographic composition can be prepared by very thoroughly mixing, such as ultrasonic wave mixing, (I) a hydrophilic photosensitive silver halide emulsion with (II) an organic solvent mixture comprising described (A), (B) and (C), and then very thoroughly mixing the resulting product with (III) comprising (a) a hydrophobic binder and (b) an oxidation-reduction image-forming composition comprising (i) a silver salt of a long-chain fatty acid with (ii) an organic reducing agent, typically in an organic solvent. The photothermographic composition can be coated on a suitable support to provide a photothermographic element.

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Rochester, NY, United States of America

John W Reeves