Patent GB-683064-A (GB)
Title: Azo dyes for color photography
IPC: G03C1/83
Filed: 1949-03-29
Abstract: Dyes, particularly for dyeing gelatin in photographic layers, have the formul  A-N=N-B-N=N-A1, <FORM:0683064/IV (c)/1> , or <FORM:0683064/IV (c)/2> wherein B is a monocyclic or polycyclic aromatic residue in which the azo bonds stand in the 1, 4 position of one ring, A and A1 are residues of azo coupling components carrying a substituent consisting of hydroxy, amino, monoalkylamino or arylamino radicals in position 2 or 4 with respect to the azo group; wherein at least one of e, f and g represent external linkages such as -CO-, -CS-, -, (linkage, valence), -CH2 where X is hydrogen, alkyl or aryl, -SO2-, -S-, -NX-, -O-, -R- where R is a bivalent hydrocarbon residue, -NH-CO-NH-, -NH-CS-NH-, -NH-R-NH-, -NH-SO2-R-SO2-NH-, -NH-CO-R-CO-NH-, -O-P(OH)-O-, -SO2NH-, -R-O- or -NH-CO- and the remainder stand for hydrogen and Z stands for a whole number greater than one; and wherein a and a1 are in position 2 or 4 with respect to the azo groups and are hydroxy, amino, monoalkylamino or arylamino radicals; b, c, b1 and c1 are hydrogen, carboxyl or sulphonic radicals or salts thereof and d, d1 are in positions other than the 2 and 4 positions with respect to the azo groups and are hydrogen, hydroxy, alkoxy, amino, halogen, alkylamino, arylamino, acylamino or arylazo radicals.  In the first of the above formul  A and A1 may be naphthalene radicals with the stated substituents; A1 may be a naphthalene radical with an OH group in the ortho position to the azo bond and having also NH- acyl or sulphonic acid substituents; or B may be represented by <FORM:0683064/IV (c)/3> wherein a, b, c and d consist of hydrogen, halogen, alkoxy, carboxyl or sulphonic groups or members of a ring; alternatively B may carry at least one ether residue in which the O is linked directly to the aromatic residue and in this case A and A1 are residues of an aminonaphthol sulphonic acid containing up to and including two sulphonic groups the amino group of at least one of the residues A and A1 being acylated with a carboxylic or sulphonic acid.  These dyes dye gelatin to cyan, blue, violet or magenta colours.  Some of them do not diffuse from the gelatin, others which do diffuse can be transformed into insoluble salts by addition to the gelatin of organic bases according to Specifications 415,756, [Group XX], 516,883 and 520,579.  The dyes may be made by (1) coupling one mol. of a para-tetrazo-compound with two mols. of an azo coupler, (2) coupling one mol. of a paraamino diazo compound with one mol. of an azo coupler, diazotizing and coupling with the same or a different coupler, (3) coupling one mol. of a para-acylamino diazo compound with an azo coupler, hydrolysing to give an amino azo dye which is diazotized and again coupled.  If the monomeric dye has two or more reactive terminal groups any desired number of dye units may be connected together in the manner described in Specification 682,665.  Lists of amino compounds and couplers are provided.  Example 1 describes the blue-green dye N-ethyl-r-acid \sM-p-nitraniline-o-sulphonic acid (reduced)--> N-ethyl-r-acid, which is purified as by repeated salting out and the sodium salt of which is water soluble, and describes also numerous other dyes based on diazotized p-nitraniline-o-sulphonic acid. Example 2 indicates acetyl-H-acid\sM-2- amino - 5 - nitrohydroquinone dimethyl ether (reduced)-->(pyridine) 1-(4-sulphophenyl) - pyrazolone - (5) - 3 - carbonic acid, and numerous alternatives as regards the couplers.  Example 3 provides extensive lists of groups corresponding to the constituent parts A-N=N-, B, and -N=N-A1 of the above formula. Example 4 is concerned with the dye p - toluenesulfo - H - acid\sM-2 - oxalylamino - 5 - amino - hydroquinone (hydrolysed) -->acetyl-K-acid and innumerable variations thereof.  Specifications 397,159 and 490,451, [Group XX], also are referred to.