GB1265061A - - Google Patents

Abstract

1,265,061. Processing photo-developable silver halide materials; monobaths. EASTMAN KODAK CO. May 1, 1969 (May 7, 1968], No. 22250/69. Heading G2C. A method of developing an internal latent image or intensifying a photo-developed image in the sensitive layer of a photo-developable silver halide material and stabilizing the resulting image comprises treating the layer with an aqueous solution in the presence of a photographic silver halide developing agent, a thiocyanate silver halide solvent and a weak silver-complexing agent (i.e. a silver ion complexing agent which inhibits the retarding effect of a stabilization retarding addendum, and which is neither a silver halide reducing agent nor a compound of which the normal or a tantomeric, form contains a mercapto group-the addendum referred to above is one which reduces the rate of dissolution of the silver halide in an aqueous stabilizing or fixing solution). The developing agent may be a 3-pyrazolidone, hydroquinone or an ascorbic acid developing agent. The weak silver-complexing agent may be an organic compound having a double bond, a halogen-substituted hydrocarbon or an organic compound containing at least one S atom having an unshared electron pair in a grouping -C-S-C-, -C-S-O-C-, or -O-CH 2 CH 2 -S- which forms part of an open chain or a ring. The weak silver-complexing agent is preferably an acyclic or cyclic ethylenic compound, an aromatic compound, an unsaturated heterocyclic compound, a halomethane, a dihaloethylene, a halobenzene, a sulphide, a sulphoxide or a sultone and may be an organic thioether silver halide solvent. The stabilization retarding addendum (see above) may be a halogen acceptor in a photo-developable emulsion e.g. 1-n-butyl-1, 2, 5, 6, -tetra-hydro- 1,3,5-triazine-4-thiol, 2, 2, 4-trimethyl-6- mercaptometadiazine, 5-methyl-2-mercaptooxazoline, phenylthiosemicarbazide or dithiomalonamide. The invention also comprises a photographic monobath composition containing a photographic silver halide developing agent, a thiocyanate silver halide solvent and a weak silver-complexing agent (as defined above).