GB820199A - New trisazo dyestuffs - Google Patents

Abstract

The invention comprises trisazo dyestuffs obtainable by combining a diazo-monoazo dyestuff of general formula <FORM:0820199/IV(c)/1> where D is a radical of an aromatic diamino compound and Z is an acid radical, in a neutral to alkaline medium with a diazo aryl sulphamide of general formula <FORM:0820199/IV(c)/2> where Ar is a benzene or naphthalene radical, X is hydrogen or a C1-C6 hydrocarbon radical, in which the aryl nucleus may be substituted by chlorine, methyl or methoxy, to form a diazo disazo dyestuff which is subsequently reacted with a 1-amino-3-hydroxybenzene or a nuclear substitution product thereof. Components specified for D are p-phenylene diamine and benzidine and their nuclear substitution products containing methyl or methoxy. Disulphonic acids specified are 1-amino-8-hydroxynaphthalene-3,5-, -3,6-, and -4,6-disulphonic acids, and amino aryl sulphamides mentioned are 1-aminobenzene-3- or -4-sulphamide, 1-amino - 3 - sulphanilide, 1 - aminobenzene - 3 - sulpho - cyclohexylamide, 1 - aminobenzene - 3 - sulpho - n - butylamide, 1 - amino - 2 - methyl - benzene - 5 - sulphamide, 1 - amino - 2 - methoxy - benzene - 4 - or - 5 - sulphamide, 1 - amino - 4 - methoxy - benzene - 3 - sulphamide, 1 - amino - 4 - methoxy - benzene - 2 - or - 3 - sulpho - methylamide, 1 - amino - 4 - methoxy - benzene - 3 - sulpho - iso - propylamide, 1 - amino - 4 - chloro - benzene - 3 - sulpho - ethylamide, 1 - amino - 2 - chloro - benzene - 5 - sulphamide, 1 - amino - naphthalene - 5 - sulphamide, and 1 - aminonaphthalene - 5 - sulphomethylamide. The 1 - amino - 3 - hydroxybenzene present as end component may be substituted for example with chlorine or methyl groups, those specified being 1-amino-3-hydroxy-4- or -6-chlorobenzene and 1-amino-3-hydroxy-4- or -6methylbenzene. An example is given of the preparation of a trisazo dye by combining 4,41-diamino-diphenyl in mineral acid medium with 1-amino-8-hydroxy naphthalene-3,6-disulphonic acid and adding diazotized 1-aminobenzene-3-sulphamide to the diazomonoazo dyestuff so formed. An aqueous solution of 1-amino-3-hydroxy benzene is then run in after the solution formed is made alkaline with sodium carbonate. The final coupling may be performed in an acetic acid or neutral medium, e.g. in the presence of sodium acetate or sodium bicarbonate. The dyestuffs may be used to dye vegetable or animal fibres, especially leather, in reddish, bluish or greenish-black shades.