Patent GB-588103-A (GB)
Title: Manufacture of trisazo-dyestuffs
IPC: C09B43/16
Filed: 1944-06-22
Abstract: Trisazo dyes, capable of being after-coppered on the fibre, are made by condensing 1 mol. of J-acid and 2 mols. of unsulphonated 4-amino-41-hydroxy-1 : 11-azobenzene-31-carboxylic acids with 1 mol. of cyanuric chloride or bromide, and coupling the product with 1 mol. of a diazotized unsulphonated o-aminobenzoic acid, or by condensing 1 mol. of cyanuric chloride or bromide with 2 mols. of unsulphonated 4-amino-41 - hydroxy - 1 : 11 - azobenzene - 3 - carboxylic acids and 1 mol. of the dyestuff obtained by coupling in an alkaline medium 1 mol. of a diazotized unsulphonated o-aminobenzene carboxylic acid with 1 mol. of J-acid.  Alternatively, 1 or 2 mols. of the azo compounds may be replaced by 1 or 2 mols. respectively of an unsulphonated 1-aminobenzene containing in the 4-position a second amino group or a nitro or acylamino group, when, after the condensation and, if necessary, after conversion of the nitro or acylamino group, the product is diazotized or tetrazotized and coupled with 1 or 2 mols. of an unsulphonated o-hydroxybenzoic acid or acids capable of coupling in the p-position to the hydroxy group, these operations being performed either before the condensation of the cyanuric halide with the J-acid or with the azo-dyestuff formed therefrom or after the coupling with the diazotized aminobenzoic acid or the condensation of the cyanuric halide with the said azo-dyestuff.  In examples: (1) anthranilic acid --> the condensation product from 1 mol. of cyanuric chloride or bromide, 1 mol. of J-acid, 1 mol. of 4-amino-41-hydroxy - 1.11 - azobenzene - 31 - carboxylic acid and 1 mol. of 4-amino-3-methoxy-5-methyl-41-hydroxy-1 : 11-azobenzene-31-carboxylic acid; the same dye is made by condensing 1 mol. of anthranilic acid --> (alkaline) J-acid and 1 mol. of each of the above azo dyes with 1 mol. of cyanuric chloride; 4-amino-41-hydroxy-1 : 11-azobenzene-31-carboxylic acid may replace the 4-amino-3-methoxy-5-methyl-41-hydroxy-1 : 11-azobenzene-31-carboxylic acid used above and the same dye is made by condensing 1 mol. of anthranilic acid --> (alkaline) J-acid and 2 mols. of 1-amino-4-acetylaminobenzene with 1 mol. of cyanuric chloride, removing the acetyl groups by saponification, tetrazotizing and coupling with 2 mols. of salicylic acid; (2) the last dye is also made by condensing 1 mol. of anthranilic acid --> (alkaline) J-acid and 2 mols. of 4-amino-41-hydroxy-1 : 11-azobenzene-31-carboxylic acid with 1 mol. of cyanuric chloride; (3) cotton is dyed with the first dyestuff of (1) above, copper sulphate and tartaric acid being added to the bath towards the end of the dyeing.  The following additional components are specified: 3- or 4-chloro-, 3 : 5-dichloro-, 4-nitro-, -acetylamino-, -benzoylamino-, -bromo-, -methoxy- or -ethoxy- or 4 : 6 - dibromo - 1 - aminobenzene - 2 - carboxylic acid; 4-amino-41-hydroxy-51-, -21-or-2-methyl-1 : 11-azobenzene-31-carboxylic acid, 4-amino-2-chloro- or -methoxy-41-hydroxy-1 : 11-azobenzene-31-carboxylic acid and 4-amino-2-methyl-5-methoxy-21-methyl-41-hydroxy-1 : 11-azobenzene-31-carboxylic acid.  For the alternative process the following intermediates may also be used: p-nitraniline, 2-methyl- or -methoxy - 4 - nitraniline, and 2 - methoxy - 5 - methyl - 4 - nitraniline; 5- or 6-methylphenol-2-carboxylic acid.  The dyes may be used for dyeing cotton, ramie, jute, viscose or cuprammonium artificial silk, or staple fibres of regenerated cellulose, which may be matted with titanium dioxide, and for dyeing mixtures thereof with animal fibres such as wool or silk.  In the latter case, the dyeing may be effected in a neutral both in presence of sodium or potassium chromate.  Specifications 209,723 and 315,665, [both in Class 2 (iii)], are referred to.  1 - Amino - 4 : 6 - dichlorobenzene - 2 - carboxylic acid is obtainable from o-toluidine by chlorination, acetylation, oxidation and hydrolysis. 1-Amino-4-benzoylaminobenzene-2-carboxylic acid is obtainable by carefully treating 1 : 4-diaminobenzene-2-carboxylic acid with an equimolecular proportion of benzoyl chloride in an aqueous medium.