GB739202A - Improvements in or relating to the production of photographic colour images - Google Patents

Abstract

739,202. Colour photography. AGFA AKT.- GES. FUR PHOTOFABRIKATION; June 5, 1953 [June 7, 1952], No. 15591/53. Class 98 (2). In the process for introducing colourcorrecting azo dye masks into multilayer silverhalide colour former materials, the material is exposed, colour developed, treated in a combined bleaching and fixing bath, and then treated with a stabilized diazonium compound which is preferably derived from aniline substituted only by halogen or alkyl groups. Reversal procedure by black and white development and re-exposure before colour development may be conducted. A preferred bleaching-fixing bath, use of which together with the preferred diazonium compounds avoids undesirable image formation in the bluesensitive layer, comprises a ferric or cobaltic complex salt of an organic acid of constitution (1) HOOC-R 1 -X-R 2 -COOH or (II) in which X is CH 2 , O, S, or N-R 3 and R 1 , R 2 and R 3 are hydrocarbon radicals which may be substituted, in which case R 3 may also be H, in formula (I) ; and X is N and R 1 , R 2 and R 4 are divalent hydrocarbon radicals which may be substituted in formula (II). Ferric complex salts of amino carboxylic acids containing more than one carboxylic end group per amino nitrogen atom as of Specification 474,082, [Group IV], are especially suitable. In example 1 an exposed silver halide multilayer colour film having a blue-sensitive layer containing 4 - stearoylamino - benzoylacetanilide - 3<SP>1</SP> - 51- dicarboxylic acid, a green sensitized layer containing 1 - (4<SP>1</SP> - phenoxy - 3<SP>1</SP> - 5<SP>1</SP> - sulpho)- phenyl-3-stearyl-5-pyrazolone and a red-sensitized layer containing the 2-methyloctadecylamino - 5<SP>1</SP> - sulphoanilide of 1 - hydroxy - 2- naphthoic acid is colour developed in a specified bath containing N-ethyl-N-#,hydroxyethyl-paminoaniline sulphate, bleached and fixed in a bath containing the sodium salt of ethylenediamine tetracetic acid, ferric chloride and sodium carbonate, sulphite and thiosulphite, and then treated in a bath containing the addition product of diazotized 5-chloro-2- toluidine and naphthalene- 1,5-disulphonic acid to produce a yellow masking image in the magenta colour image layer and an orange masking image in the blue-green colour image layer. In example 2 the coupler in the redsensitized layer is replaced by 21-methyloctadecylamino - 5<SP>1</SP> - sulphoanilide of 1- hydroxy - 4 - sulpho 2 - naphthoic acid, whereby the magenta colour image layer only contains a mask. Example 3 describes reversal processing of the film of example 1 and replaces the diazo compound with the addition product of diazotized 4-chloro-2-toluidine and acetamido-p-sulphonic acid. False colour procedure is indicated. Specifications 602,881, 645,170, 652,953, 665,657 and 701,039.also are referred to.