Photographic developing process
AssigneeCiba-Geiby Corporation
InventorsJohn Lenoir, Max Marthaler
Life of this patent
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Abstract
A process for developing photographic silver halide material, which has been exposed image-wise is provided. The aqueous developer preparation used contains a developer compound for the silver halide, a water-soluble solvent for the silver halide and an aliphatic, cycloaliphatic, aromatic or heterocyclic di- or trisulphide. These preparations remain clear over a long period of time during which they do not lose their effectiveness by becoming turbid or by sedimentation of silver. They are of special advantage in continuously operated photographic developing processes.
Claims18
Process for developing a photographic material, which contains a silver halide and has been exposed image-wise, using an aqueous preparation which contains (a) a developer for the silver halide, (b) a water-soluble solvent for the silver halide selected from the group consisting of thioethers, thioamides and salts of thiocyanic, sulphurous and thiosulphuric acid or mixtures of these compounds containing as one component a salt of sulphurous acid and (c) as a compounds which avoids the deposition of metallic silver, a compound of divalent sulphur in solution, wherein this sulphur compound corresponds to the formula ##STR46## in which B.sub.1 and D.sub.1 each denote ##STR47## wherein R.sub.1 is hydrogen, alkyl or hydroxyalkyl with 1 to 6 carbon atoms, phenyl, tolyl, cycloalkyl of 5 to 6 carbon atoms, or a five-membered to six-membered hetero-ring which contains 1 to 3 nitrogen atoms or 1 oxygen atom or 1 sulphur atom, or is a carboxylic acid group, R.sub.2 is a direct bond or alkylene of 1 to 4 carbon atoms or phenylene, R.sub.3 is hydrogen or alkyl of 1 to 2 carbon atoms or B.sub.1 and D.sub.1 each denote a cycloaliphatic radical of 5 to 6 carbon atoms, phenylene or a heterocyclic 5-membered or 6-membered ring and such ring fused with a further benzene ring, and the hetero-ring contains 1 to 3 nitrogen atoms, an oxygen atom or a sulphur atom, m.sub.1 and n.sub.1 each represent one of the numbers 1, 2 and 3, p represents 1 or 2 and A.sub.2 and E.sub.2 independently of one another each represent a radical of the formulae ##STR48## in which X and Y in each case are hydrogen or alkyl of at most 8 carbon atoms and is optionally substituted by hydroxyl groups, carboxylic acid groups or sulphonic acid groups and Y also represents a phenylsulphonic acid group, a lower alkylsulphonyl group or a phenylsulphonyl group and M represents a monovalent cation and Z has the meaning of X and Y with the exception of hydrogen.
Process according to claim 3, wherein the developer preparation contains a sulphur compound of the formula ##STR51## in which m.sub.2 and A.sub.3 have the meanings indicated in claim 5, R.sub.4 is a direct bond or alkylene of 1 to 4 carbon atoms, R.sub.5 is hydrogen, --CH.sub.3, --CH.sub.2 OH, --COOH, --CH.sub.2 COOH, cyclopentyl, cyclohexyl, phenyl, tolyl, furyl or thienyl and R.sub.6 is hydrogen, methyl or ethyl.
Preparation for developing a silver halide photographic material which has been exposed image-wise, which preparation contains (a) a developer substance for the silver halide, (b) a water-soluble solvent for the silver halide and (c) a compound of divalent sulphur in solution, wherein this sulphur compound corresponds to the formula ##STR64## in which B.sub.1 and D.sub.1 each denote ##STR65## wherein R.sub.1 is hydrogen, alkyl or hydroxyalkyl with 1 to 6 carbon atoms, phenyl, tolyl, cycloalkyl of 5 to 6 carbon atoms or a five-membered to six-membered hetero-ring which contains 1 to 3 nitrogen atoms or 1 oxygen atom or 1 sulphur atom, or is a carboxylic acid group, R.sub.2 is a direct bond or alkylene of 1 to 4 carbon atoms or phenylene, R.sub.3 is hydrogen or alkyl of 1 to 2 carbon atoms or B.sub.1 and D.sub.1 each denote a cycloaliphatic radical of 5 to 6 carbon atoms, phenylene or a heterocyclic 5-membered or 6-membered ring and such ring fused with a further benzene ring, and the hetero-ring contains 1 to 3 nitrogen atoms, an oxygen atom or a sulphur atom, m.sub.1 and n.sub.1 each represents one of the numbers 1, 2 and 3, p represents 1 or 2 and A.sub.2 and E.sub.2 independently of one another each represent a radical of the formulae ##STR66## in which X and y in each case are hydrogen or alkyl of at most 8 carbon atoms and is optionally substituted by hydroxyl groups, carboxylic acid groups or sulphonic acid groups and Y also represents a phenylsulphonic acid group, a lower alkylsulphonyl group or a phenylsulphonyl group and M represents a monovalent cation and Z has the the meaning of X and Y with the exception of the hydrogen.
Dependencies are inferred from the claim text.