Patent GB-552009-A (GB)
Title: Improvements in or relating to processes of colour photography
IPC: G03C7/32
Filed: 1941-02-28
Abstract: 552,009. Dyes ; acid amides and chlorides. DU PONT DE NEMOURS & CO., E. I., HANFORD, W. E., KIRBY, J. E., and WOODWARD, D. W. Feb. 28,1941, No. 2736. [Class 2 (iii)] [Also in Group XX] A photographic element containing an image in a developable silver salt is developed to a coloured image with an aromatic amino colour-developing agent in the presence of a colour former which is a compound of the general formula Ar-NH-CO-R-CO-X, wherein Ar represents a monovalent organic radicle of the kind suitable for the production of an indoaniline, indophenol, indamine or azomethine dyestuff, R represents an aliphatic or cycloaliphatic radicle containing at least 4 carbon atoms, and X represents amino, hydroxyl, halogen or OR<SP>I</SP>, wherein R<SP>1</SP> represents the residue of an organic compound R<SP>1</SP>-OH esterifiable by acids. In examples (4), (6) and (12) a photographic film bearing a latent silver image is developed in a solution of p-aminodiethylaniline containing (4) N-mhydroxyphenyladipamic acid, (6) N-m- (3-methyl-5-ketopyrazyl) phenyladipamic acid, (12) N-p-acetoacetylaminophenyladipamic acid, washed and treated with Farmer's reducer to obtain a blue indophenol, a magenta and a yellow azomethine dye image respectively. Other specified developers are 1:4-diaminobenzene, p-aminodimethylaniline, p-aminodibutylaniline, p-methylaminoaniline, p-ethylaminoaniline, p-aminophenol, o-aminodimethylaniline, chloro-1:4-diaminobenzene, 1:2:5- toluylenediamine, 2 - amino - 5 - diethylamino - toluene and N - p - amino - phenylpiperidine. Amides of the above general formula are obtainable by condensation of a monochloride of the formula C1-CO-R-CO-OR<SP>1</SP> with an amine of the formula Ar-NH 2  and conversion, if necessary, of the ester group-CO-OR<SP>1</SP> to the free acid, amide or acid halide. Examples are given of the production of colour-formers by the condensation of the chloride of monomethyladipate with (1) o-aminophenol in ether containing sodium hydroxide; (2) m-aminophenol in ether containing sodium hydroxide; (3)-0- or m-aminophenol in pyridine ; (5) 1-(mamino) phenyl-3-methyl-5-pyrazolone in pyridine ; (7) and (8) p-nitroaniliine in ether containing sodium hydroxide, with subsequent reduction of the nitro group to amino ; (9) paminoazobenzene in pyridine, with subsequent reduction to replace the p-aminophenylazo group by the amino group ; (11) p-aminoacetoacetanilide hydrochloride in pyridine ; (13) 1:5-aminonaphthol in benzene containing pyridine, and by the condensation of (14) and (15) the chlorides of monomethylsebacate and monomethyltetradecanedioate respectively with m-aminophenol in pyridine. When the residue Ar-NH- in the product carries a nuclear primary amino group, other colour formers are obtainable by (a) condensation with a #- ketonic ester, e.g. ethylacetoacetate, (b) conversion of the primary amino group into a hydrazino group and condensation of the product with a #-ketonic ester to obtain a pyrazolone, (c) diazotization and hydrolysis to replace the primary amino group by a phenolic hydroxyl group, (d) alkylation of the primary amino group. In a further example (10), N-p-aminophenyladipamic acid is condensed with ethylacetoacetate. The chlorides of monomethyladipate, monomethylsebacate and tetradecanedioate are obtained by treating the monomethyl esters with thionyl chloride.