Patent GB-695876-A (GB)
Title: Photographic process
Inventor: GANGUIN KARL OTTO
IPC: G03C1/83
Filed: 1950-06-15
Abstract: 695,876. Colour photography. IMPERIAL CHEMICAL INDUSTRIES, Ltd. June 15, 1951 [June 15, 1950], No. 14947/50. Class 98 (ii). An exposed multilayer colour photographic material comprising differently colour sensitized silver halide emulsion layers and at least one filter layer containing a yellow non-diffusible styryl dye (including one rendered non-diffusible by the method of forming the coating composition) is treated with an aqueous solution of a substituted or unsubstituted arylenediamine, under more severe conditions than those normally used for colour development, in order to colour develop the latent image and also to discharge the styryl dye in the filter layer. The material may first be normally colour developed and then further treated with a substituted or unsubstituted arylene diamine during or after the fixing step to discharge the styryl dye. A surface-active agent may be added to the arylene diamine solution used to effect dyedischarge, and the material may be subsequently treated with dilute alkali solution, or where the arylene diamine solution used for colour development is used to effect dyedischarge, the surface-active agent is added to any subsequent processing bath, e.g. the stopbath. The surface-active agent may be a condensation product of a phenol or alkylphenol with ethylene oxide, a condensation product of an aliphatic alcohol, e.g. cetyl alcohol, with ethylene oxide, an alkylated sulphonated hydrocarbon, or a quaternary ammonium salt containing a long alkyl chain, e.g. cetyltrimethylammonium bromide. The arylene diamine may be N: N - diethyl -p - phenylenediamine, 5 - diethylamino - 2 - aminotoluene, or 5 - amino - 2 - N - ethyl: N -#-hydroxyethylaminotoluene. The free diamine may be formed in situ from a salt of the diamine and an alkali. The styryl dye may be one formed by condensing a reactive methylene compound with an anil of a substituted benzaldehyde, preferably containing solubilizing groups. Numerous substituted benzaldehydes are specified, and the reactive methylene compound may be 1-#-octadecenylsuccinamido - 4 - # - cyanoacetobenzene, a thioindoxyl, 1 - (4<SP>1</SP> - phenoxy - 31 - sulphophenyl) - 3 - heptadecyl - 5 - pyrazolone, 3 - heptadecyl - 5-pyrazolone, or 1-(3<SP>1</SP>-carboxyphenyl)-3-p-stearamidophenyl - 5 - pyrazolone. A soluble salt of the dye may be incorporated in a gelatine solution and the composition coated as a filter layer. Diffusible dyes may be precipitated, e.g. with a high molecular weight base, in the gelatine, or may be dissolved together with a water-insoluble water-permeable resin, e.g. polyvinyl acetate, in a volatile organic watermiscible solvent, and the solution dispersed in the gelatine and the solvent evaporated off. In example 1, a support is successively coated with a red-sensitive emulsion layer containing the sodium salt of 1-hydroxy-4-sulpho-2-naphthoyloctadecylamide, a green-sensitive emulsion containing the sodium salt of 1-(4<SP>1</SP>-phenoxy-3<SP>1</SP>- sulphophenyl) - 3 - heptadecyl - 5 - pyrazolone, a yellow gelatine filter layer containing the sodium salt of 1-(41-phenoxy-31-sulphophenyl) 3 - heptadecyl - 4 - (p - N - methyl: N - # . sulphoethylaminobenzylidene) - 5 - pyrazolone, and a blue-sensitive emulsion containing the sodium salt of 3-(p-anisoylacetamino)-4-(N- methyl: N-octadecylamino)-benzoic acid. After exposure, the material is colour developed, with simultaneous decolorization of the filter layer, in a solution including 5-diethylamino-2-aminotoluene hydrochloride, hydroxylamine hydrochloride, and sodium carbonate, rinsed, treated in an aqueous stop bath containing sodium acetate, acetic acid, and the condensation product of octyl-cresol with 10 molecular proportions of ethylene oxide, washed, the silver removed, washed, fixed, and dried. In example 2, the material is similar, and after exposure is colour developed, rinsed, treated in an aqueous sodium acetate-acetic acid stop bath, washed, silver removed, washed, fixed, rinsed, treated in a filter-decolorizing solution including 6-amino- 3-N-ethyl: N-#-hydroxyethylaminotoluene sulphate, hydroxylamine hydrochloride, sodium carbonate, ethanol, and the condensation product of octyl-cresol with about 10 molecular proportions of ethylene oxide.