Ciba-geigy Ag

Christoph Chylewski

Matthias Schellenberg

Max Meier

Gerald Jan

Max Marthaler

Roland Kurzen

Herbert Mollet

Leslie F Mason

Robert Stanley Cook

Alfred Oetiker

David Kilcast

A method of processing photographic silver dye bleach materials which have been exposed imagewise is provided. The process steps are (1) silver developing, (2) dye bleaching, (3) silver bleaching and (4) fixing. The treatment baths for the process steps (2), (3) and (4), or the combined treatment baths useful for process step (3) with at least one the process steps (2) or (4) contain water-soluble tertiary phosphines as silver ligands. These phosphines effect an acceleration of the dye and silver bleaching and they are further suitable stabilizers and optionally antioxidants which yield stable treatment baths.

Use of tertiary phosphines in photographic silver dye bleach materials

A new method to produce photographic images is provided which comprises

Process for producing photographic images

The present invention provides a new process for the production of masked subtractive positive color images by the silver dye bleach process, which comprises the steps of exposure, silver developing, dye-bleaching, silver-bleaching and fixing. The photographic material used contains, in at least two layers, one image-wise bleachable dye per layer, the absorption maximum of the dye corresponding in each case to one of the three primary colors red, green and blue and a silver halide emulsion layer sensitive in a specific spectral region being allocated to each dye, wherein this material (a) in at least one layer contains a dye, the undesired secondary color density of which is to be compensated, and a silver halide emulsion containing silver iodide is allocated to this dye, in the same layer and/or an adjacent layer, (b) in at least one further layer contains at least one further dye, the main color density of which corresponds to a secondary color density, which is to be compensated, of the first dye, and also a silver halide emulsion free from iodide ions, (c) contains a further layer which is adjacent to layer (b) and contains colloidal nuclei which are able, under reducing conditions, to deposit metallic silver from soluble silver complexes, and also contains an insensitive iodide-free silver halide emulsion which is not spectrally sensitized, and optionally a stabilizer, and (d) containing a separating layer, which does not contain any of the dyes of the layer or layers (a), between the layer or layers (a) and the layer (c). The silver developing bath with which the material is treated contains ligands which form water-soluble and diffusible silver complexes with silver.

Process for the production of masked positive color images by the silver

Method of processing photographic silver dye bleach materials

The present invention relates to an oil-in-water emulsion which is suitable for processing photographic material. There is present or produced during the processing a substance which exerts its action on the photographic material from the aqueous phase. Contingent on the consumption the active substance is replenished or regenerated from the oily phase. The active substance is more readily soluble in the oily phase than in the aqueous one. The active substance may be, e.g., a dye bleach catalyst for silver dye bleach material or an alkylmercaptan, the latter acting as an antioxidant.

Preparation for the processing of photographic materials

The present invention relates to a simplified method for processing silver dye bleach material by (1) silver developing, (2) dye and silver bleaching (3) silver fixing and (4) soaking. The sequence (1), (2), (3), (4) is followed and the bleaching bath (2) contains (a) a strong acid, (b) a water-soluble iodide, (c) a water-soluble oxidizing agent (d) an antioxidant and (e) a dye bleach catalyst.

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Marly, Switzerland

Christoph Chylewski