Eastman-kodak Company

Rowland G Mowrey

Richard C Sutton

Richard P Henzel

Eugene A Armour

Wilbert J Humphlett

Edwin N Oftedahl

Photographic assemblages are described employing positive-working redox dye-releasers and a cover sheet containing an oxidant having an electrode potential of from about -200 mV up to about 1000 mV versus a saturated calomel electrode at a pH of about 5 to about 6. The oxidant is capable of oxidizing electron transfer agent in the system. The reduced form of the oxidant is incapable of reducing the positive-working redox dye-releaser. After processing, the oxidant reacts with the electron transfer agent to prevent it from reacting with the dye releaser which would otherwise cause further dye release. D.sub.min stability is thereby improved.

Reducing post-process D.sub.min increase in positive redox dye-releasing

A dry, activator sheet for a dry, thermal silver dye bleach process comprises a support having thereon a non-volatile, diffusible acid, a substituted heterocyclic thiazoline, oxazoline, imidazoline or imidazolidine silver halide complexing agent and a non-hydrolyzable polymer vehicle having an effective pH up to 6.0 and a melting point lower than 200.degree. C. The activating sheet is useful to bleach a silver image containing a bleachable dye.

Dry heat-activated bleaching of silver images

A dry, activator sheet for a dry, thermal silver dye-bleach process, in the absence of a silver dye-bleach catalyst, comprises a support having thereon a nonvolatile, diffusible acid and a non-hydrolyzable polymeric vehicle having an effective pH up to 4.0 and a melting point lower than 200.degree. C. The activator sheet is useful to bleach a silver image containing a bleachable dye.

Photographic elements are described which comprise a support having thereon at least one image dye-providing layer unit and at least one layer containing an immobile anionic organic acid having an equivalent weight based on acid groups of at least 70 and less than 800. In one embodiment, photographic elements of this invention can be contacted with a transition metal-ion complex such as a cobalt(III) ion complex before contact with a fixing bath and sufficient transition metal ion will be retained in the photographic element to bleach the silver in said element.

Photographic elements containing anionic organic acids

Photographic elements are described which comprise a support having thereon at least one image dye-providing layer unit and at least one layer containing an immobile anionic organic acid having an equivalent weight based on acid groups of at least 70 and less than 800. In one embodiment of this invention, photographic elements can be contacted with a transition metal-ion complex such as a cobalt(III) ion complex before contact with a fixing bath and sufficient transition metal ion will be retained in the photographic element to bleach the silver in said element.

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Rochester, NY, United States of America

Rowland G Mowrey