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US 4,229,521 AGranted
Method of processing photographic materials
AssigneeAgfa-Gevaert
InventorsKarl Frank, Hans-Dieter Block
Life of this patent
Estimating the term…
Abstract
A new bath composition for processing photographic materials with at least one silver halide layer is provided in which discolorations caused by Fe III-bleaching agents are prevented by an after-treatment bath comprising phosphoric acid or a phosphonic acid as hereinafter described.
Claims6
A process for producing color photographic images by imagewise exposure of a color photographic material containing at least one silver halide emulsion layer, color development, bleaching, after-treatment with an acid compound capable of discoloration prevention, in a bath and fixing,
- wherein the improvement comprises the photographic material is first treated with a bleaching bath containing an iron III salt and then is treated with a bath which contains an effective amount of an acid discoloration preventative compound corresponding to the following general formula:
- A--PO.sub.3 H.sub.2
- wherein A denotes hydroxyl or an alkyl group having from 1 to 6 C atoms which is substituted with at least one carboxyl group.
Dependencies are inferred from the claim text.