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AssigneeAgfa-Gevaert
InventorsHugo Zorn, Karl Kuffner, Hans Glockner, Jozef Frans Willems, Robrecht Julius Thiers
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Heterocyclic mercapto compounds are added to a binder layer containing colloidal silver which is comprised in a color photographic multilayer material. The colloidal silver layer may be a yellow filter layer to prevent exposure of the green, and red recording layers to blue light, or an antihalation layer arranged between the layer support and the lowermost light sensitive silver halide emulsion layer. The heterocyclic mercapto compounds reduce the contact fog produced in the (first) developer and increase color density in reversal processing. Additionally there can be present in the colloidal silver layer a sensitizer for the blue, green or red spectral region.
A color photographic multi-layer material having compounds that produce an image by image-wise exposure followed by developing treatment producing an image comprising at least two spectrally sensitized silver halide emulsion layers each containing a color coupler and at least one other layer containing a binder and colloidal silver, wherein the improvement comprises the binder and colloidal silver layer contains a non-diffusible heterocyclic mercapto compound carrying a substituent consisting of an aliphatic hydrocarbon group having 8 to 20 carbon atoms and a mercapto group on a ring carbon atom of a 5- or 6- membered heterocyclic ring, said heterocyclic mercapto compound being in an amount of 0.1 to 1 g per g of colloidal silver.
Dependencies are inferred from the claim text.