GB743957A - Tetrakisazo dyestuffs - Google Patents

Abstract

The invention comprises dyes of the formula:-<FORM:0743957/IV(c)/1> wherein one R1 means H, and the other SO3H, one R2 means H, the other H, alkyl, alkoxy, carboxy, or sulpho, R3 means H or hydroxyalkyl, and R4 means H, alkyl, or alkoxy. They and other dyes are made by coupling tetrazo compounds of disazo dyes of the formula:- <FORM:0743957/IV(c)/2> (where A means the residue of a 4.41-diamino-diphenylamine-2-sulphonic acid which may contain further substituents in the benzene nuclei, B1 is the residue of 1-amino -5- hydroxynaphthalene -7- sulphonic acid. B2 is the residue of the same or another amino - hydroxy - naphthalene-sulphonic acid capable of coupling and diazotizing) with 2 moles of a 1.3-diamine of the benzene series, which contains no solubilizing groups. In examples the disazo dyes from 1 mol 4.41-diamino-diphenylamine-2-sulphonic acid and (1) 2 mols 1-amino -5- hydroxynaphthalene -7- sulphonic acid, (2) a mixture of 2-amino-8 -hydroxynaphthalene-6-sulphonic acid and 1- amino -5- hydroxynaphthalene -7- sulphonic acid and (3) successively 1-amino-5-hydroxynaphthalene -7- sulphonic acid and 1 - amino -8- hydroxynaphthalene-4-sulphonic acid, are each tetrazotized and coupled with 2 mols. 1.3-diaminobenzene. Other reactants are specified. The products dye cellulose fibres black shades. Specifications 470,407 and 703,446 are referred to.