Thermally processable element comprising an overcoat layer containing poly(silicic acid)
AssigneeEastman Kodak Company
InventorWojciech M. Przezdziecki
Life of this patent
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Abstract
A overcoat layer comprising poly(silicic acid) ##STR1## on a thermally processable element enables reduced release of volatile components from the element during thermal processing. The overcoat layer also can optionally comprise other water soluble polymers. A developed visible image is provided in an exposed silver halide photothermographic element comprising such an overcoat by uniformly heating the photothermographic element to moderately elevated temperatures without release of volatile components. The described overcoat is also useful on thermographic elements.
Claims12
In a photothermographic or thermographic imaging element comprising a support, bearing a photothermographic or thermographic imaging layer and an overcoat layer, the improvement wherein the overcoat layer comprises 50% to 90% by weight poly(silicic acid) represented by the formula:
- ##STR7## wherein x is an integer within the range of at least 3 to about 600 and comprises a water soluble hydroxyl containing polymer or monomer that is compatible with poly(silicic acid).
A photothermographic element comprising a support bearing a photothermographic silver halide emulsion layer and an overcoat layer comprising 50% to 90% by weight poly(silicic acid) represented by the formula:
- ##STR8## wherein x is an integer within the range of at least 3 to about 600 and comprising a water soluble hydroxyl containing polymer or monomer that is compatible with poly(silicic acid).
A photothermographic element comprising a support bearing in reactive association, in a binder,
- (a) photographic silver halide,
- (b) an image-forming combination comprising
- (i) an organic silver salt oxidizing agent, with
- (ii) a reducing agent for the organic silver salt oxidizing agent,
- (c) a toning agent;
- and having an overcoat layer comprising 50% to 90% by weight poly(silicic acid) represented by the formula:
- ##STR9## wherein x is an integer within the range of at least 3 to about 600 and comprising a water soluble hydroxyl containing polymer or monomer that is compatible with poly(silicic acid).
In a thermographic element comprising a support bearing a thermographic layer and an overcoat layer, the improvement wherein the overcoat layer comprises 50% to 90% by weight poly(silicic acid) represented by the formula:
- ##STR11## wherein x is an integer within the range of at least 3 to about 600 and comprises a water soluble hydroxyl containing polymer or monomer that is compatible with poly(silicic acid).
Dependencies are inferred from the claim text.