GB798545A - Manufacture of trisazo dyestuffs - Google Patents

Abstract

The invention comprises dyestuffs obtainable by combining a compound of formula <FORM:0798545/IV (b)/1> where D is the residue of a tetrazotizable diamine of the benzene or diphenyl series, n is 1 or 2 and Z an acid residue, in a neutral to alkaline medium with a diazo benzene sulphonic acid containing at least one methyl- or alkoxy-group as nuclear substituent to form a diazo disazo dyestuff which is treated with 1-amino-3-hydroxybenzene which may be substituted in the nucleus or in the amino group. Benzidine and its substitution products are indicated as tetrazotizable diamines. Specified benzene sulphonic acids are aniline-2-methyl- and -methoxy-4- and -5-, -3-methyl-4- and -6-, -4-methyl- and -methoxy-2- and -3-, -2,4 - dimethyl- and -dimethoxy - 6-, -2,6 - dimethyl - 4-, -2,5 - dimethoxy - 4- and -2-methoxy - 5 - methyl - 4 - sulphonic acids. 1-Amino-8-naphthol-3,5-, -3,6- and -4,6-di- and -4- and -5-mono-sulphonic acids are specified middle components. Indicated as end components are m-aminophenol which may contain chlorine or methyl nuclear substituents or N-alkyl, -hydroxy-alkyl, -aralkyl, or aryl substituents. The dyestuffs dye leather in bluish or black shades. Examples are provided illustrating the preparation of the dyestuffs from certain of the components specified above and their use as leather dyes. Specification 763,064 is referred to.