Patent GB-817871-A (GB)
Title: Improvements relating to tetrakisazo dyestuffs and their use
IPC: C09B43/12
Filed: 1956-05-16
Abstract: The invention comprises tetrakisazo dyestuffs of formula R1-N=N-R2-N=N-R3-NH-Ar-CO-NH -R13-N=N-R12-N=N-R11\t wherein R1 and R11 are benzene or naphthalene radicals, R2 and R12 are benzene or naphthalene radicals in which the azo groups are in p-position, R3, R13 and Ar are p-phenylen radicals, whilst of R2 and R3 and R12 and R13 at least one is a 1 : 4-phenylene-2-acylamino radical and each of the pairs of radicals R1 and R2 and R11 and R12, together contain two or three water-solubilizing groups which dissociate acid in neutral water.  The dyes are prepared by condensing two idential or different molecules of an aminodisazo dye of formula R1-N=N-R2-N=N-R3-NH2 wherein R1, R2 and R3 are defined above, with a terephthaloyl halide. The aminodisazo dyes may be prepared by coupling a diazotized phenyl- or naphthyl-amine (first component) with a benzene or naphthalene compound (second component) coupling para to an amino group, preferably a 1-amino-3-acylamino-benzene. The first and second components must together contain two or three water-solubilizing groups and may be further substituted by halogenatoms, or alkyl, alkoxy, acylamino, alkyl or arylsulphonyl or sulphonamide groups. Alternatively a 4-nitro- or -acylamino-1-amino-benzene sulphonic acid is diazotized, coupled with an o-hydroxybenzoic acid and the nitro or acylamino group converted to an amino group.  The p-aminoazo dyes so obtained are diazotized and coupled with a benzene azo component (third component) coupling para to an amino group.  The condensation of the aminodisazo dye with a terephthaloyl halide is carried out in an aqueous solution of an alkali metal salt of the dye and in the presence of an acid-binding agent such as sodium acetate, carbonate, hydroxide or di- or tri-phosphate, magnesium oxide and pyridine.  The dyes give yellow, orange to brown dyeings on cellulose fibres.  In examples: (1) 2 mols. of an aminodisazo dye obtained from the following components are condensed with 1 mol. of terephthaloyl chloride or its 2 : 5-di-methyl, -methoxy or -chloro derivative; first component: 2 - aminonaphthalene - 3 : 6 - or - 4 : 8 - or -5 : 7- or -6 : 8-disulphonic acid, 1-aminonaphthalene-3 : 6- or - 3 : 8-disulphonic acid 1 - amino - 2 - methylbenzene - 4 - sulphonic acid, 1-aminobenzene-3- or -4-sulphonic acid, 1-amino - 3 - carboxy - 4 - hydroxybenzene - 5 - sulphonic acid, 1 - aminobenzene - 2 : 5 - disulphonic acid, 1 - amino - 2 : 4 - dimethylbenzene - 6 - sulphonic acid, 1 - aminobenzene-3 - carboxylic acid, 1 - amino - 4 - nitrobenzene-3 - carboxylic acid, 1 - amino - 2 - carboxybenzene - 4 - sulphonic acid; a second component: m - toluidine, 1 - amino - 2 - methoxy-5 - methylbenzene, 1 - amino - 2 - methyl - or methoxy - 5 - acetylaminobenzene, 1 - amino - 3 - acetylamino -, - formylamino -, - carbomethoxyamino -, butyroylamino -, or - sulphoacetylamino - benzene, 1 - aminophenyl - (3) - oxamic acid; 1-amino-2 : 5-dimethylbenzene, sulphonic acid, 1 - amino - 2 - methylbenzene-6-sulphonic acid; third component: aniline, m - toluidine, m - anisidine, 1 - amino - 3 - acetylamino-, -formylamino-, -carbomethoxyamino-, -carboethoxyamino-, or -carbomethoxyethoxyamino-benzene and 1-amino-2-methoxy-5-methylbenzene; (2) equimolar proportions of the aminodisazo dyes 2-aminonaphthalene - 6 : 8 - disulphonic acid --> m - toludine --> 1 - amino - 3 - acetylaminobenzene and 1 - aminobenzene - 2 : 5 - disulphonic acid --> 1 - amino - 3 - acetylaminobenzene --> m-toluidine are condensed with terephthaloyl chloride.