Eastman-kodak Company

Ktrom Industries, Inc.

James R King

Hyman L Cohen

Samuel J Ciurca

David A Pupo

Grant M Haist

Lewis M Minsk

A first metal is removed from solutions such as polluted water by contacting the solution with a metallic exchange medium. The metallic exchange medium comprises a plurality of buoyant elements, each comprising a substrate coated with a second metal sufficiently reactive to undergo an electrochemical exchange reaction with the first metal. The substrate can be expanded polystyrene beads and the metal can be iron such as sponge iron of small particle size.

Metal removal apparatus and method

Silver is recovered from solutions such as photographic fixer solutions by contacting the solution with a metallic exchange medium. The metallic exchange medium comprises a plurality of buoyant elements, each comprising a substrate coated with iron. The substrate can be expanded polystyrene beads and the iron can be sponge iron of small particle size.

Silver removal apparatus and method

Photographic elements for providing black-and-white images contain a silver halide emulsion having associated therewith a non-diffusible resorcinol coupler and a color developing agent or a precursor of a color developing agent. The elements can be processed by simple alkaline activation. Since image density is derived at least in part from the resorcinol coupler, lower silver halide coverages can be employed or the silver can be recovered, or both.

Black-and-white photographic elements and processes

A radiation-sensitive element in which silver halide is the sole source of image-forming silver containing incorporated processing chemicals is processed in a fluid activator which does not cause the processed element to be tacky. The element includes a fluid-impermeable support having thereon a radiation-sensitive material in a hydrophobic binder which is impermeable to water. Activation of the exposed radiation-sensitive material by the fluid activating agent results in a processed element which is dry to the touch and is substantially free from tackiness when removed from contact with the fluid activator. If a stabilizer precursor is incorporated in the element, the image is unaffected by further exposure to radiation.

Photographic element and process for developing

Polymers comprising quaternary nitrogen atoms and at least two aromatic nuclei in the polymer cation for each quaternary nitrogen atom are described. In one embodiment at least 1/3 of the units of said polymer comprise quaternary nitrogen atoms. In another embodiment polymers comprising at least two aromatic nuclei in the polymer cation, such as aryl groups, for each quaternary nitrogen atom can be used in photograhic elements to provide excellent mordants for dyes.

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Rochester, NY, United States of America

James R King