Spectrally sensitized photothermographic elements
AssigneeEastman Kodak Company
InventorHeidi E. Dankosh
Life of this patent
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Abstract
Improved photothermographic elements are spectrally sensitized with cyanine dyes that provide efficient sensitization together with excellent keeping stability and low dye stain. The photothermographic elements comprise a photosensitive silver halide, an organic silver salt, such as silver behenate, and a reducing agent. The cyanine dye utilized as a spectral sensitizer for the silver halide is an anionic cyanine dye comprising two thiazole nuclei each of which is substituted with an N-sulfoalkyl group wherein at least one of the thiazole nuclei is a 5,6-dihalobenzothiazole nucleus.
Claims18
A photothermographic element comprised of a support bearing one or more layers comprising:
- (a) a photosensitive silver halide, prepared in situ or ex situ,
- (b) an organic silver salt;
- and
- (c) a reducing agent;
- in concentrations such that imagewise exposure to actinic radiation generates from the silver halide a catalyst which accelerates an image-forming reaction between the organic silver salt and the reducing agent;
- wherein the photosensitive silver halide is spectrally sensitized with an anionic cyanine dye comprising two thiazole nuclei each of which is substituted with an N-sulfoalkyl group, with the proviso that at least one of said thiazole nuclei is a 5,6-dihalobenzothiazole nucleus.
Dependencies are inferred from the claim text.