Photograhic silver halide material and process for preparing silver images
AssigneeAgfa-Gevaert
InventorsFrancois Varescon, Reinhold Ruger
Life of this patent
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Abstract
It was found that good sensitizing activity in the red spectral region and without residual stain can be obtained with dyes of the general formula (I) ##STR1## wherein R.sub.1 is an alkyl group having 1 to 6 carbon atoms or a heterocyclic ring, R.sub.2 and R.sub.3 are hydrogen, methyl, or methoxy, but at least one of the groups R.sub.2 and R.sub.3 is not hydrogen, R.sub.4 and R.sub.5 are alkyl groups having 1 to 6 carbon atoms that can be substituted with hydroxyl groups, and X.sup.- is an anion. The invention can be used for preparing silver images, for example, for reproduction in preprint operations for black and white or multicolor printing.
Claims8
A photographic silver halide material comprising at least one photosensitive, silver halide emulsion layer on a support, the emulsion layer containing at least one sensitizing dye that sensitizes the silver halide for light in 600 to 690 nm spectral range, said sensitizing dye having the formula (I) ##STR7## wherein R.sub.1 is an alkyl group having 1 to 6 carbon atoms or a heterocyclic ring, R.sub.2 and R.sub.3 are hydrogen, methyl, or methoxy, but at least one of the groups R.sub.2 and R.sub.3 is not hydrogen, R.sub.4 and R.sub.5 are alkyl groups having 1 to 6 carbon atoms that can be substituted with hydroxyl groups and X.sup.- is an anion;
- wherein said sensitizing dye does not contain a sulfonic acid group or a carboxyl group in its molecule.
A process for preparing a silver image, comprising exposing and processing the photographic recording material of one of the preceding claims.
Dependencies are inferred from the claim text.