GB820472A - Copper-containing polyazo dyestuffs - Google Patents

Abstract

The invention comprises the copper complexes of polyazo dyestuffs of formula <FORM:0820472/IV(c)/1> wherein R and R1 are radicals, the same or different, of a coupling component bearing the hydroxyl group in ortho-position to -N=N-, Z is an azo or azoxy group and X is hydrogen or a sulphonic acid group. The copper complexes are obtained by diazotizing aminonitronaphthalenes of formula <FORM:0820472/IV(c)/2> coupling with azo components coupling ortho to an hydroxy group, oxidizing coppering the azo dyes thus obtained (e.g. by treatment with copper sulphate and hydrogen peroxide) and then reducing the coppered nitrogen compounds in known manner (e.g. with glucose in aqueous caustic soda) so that 2 molecules are linked by an azo or azoxy group. Alternatively the complexes may be prepared by linking the uncoppered nitrogen compounds by reduction and oxidizing coppering the polyazo dye thus obtained. Finally the copper complexes may be obtained by tetrazotizing compounds of formula <FORM:0820472/IV(c)/3> wherein Z and X are as defined above, coupling with the same or different azo components which couple ortho to an hydroxy group and oxidizing coppering the polyazo dye so obtained. The copper complexes dye cellulose fibres in blue or grey shades. Specified p coupling components include acetoacetanilide, phenols, naphthols, naphthol-sulphonic acids, aminonaphtholsulphonic acids, 1-(sulphophenyl or -naphthyl)-3-methyl-5-pyrazolones, 1-phenyl-3-carboxy-5-pyrazolone, 4-hydroxy-azobenzene-41-sulphonic acid and 1-hydroxy-3-sulpho-5-chloronaphthalene - [6 : 11] - azo - 21 - naphthol - 31 : 61 - disulphonic acid. Specifications 660,447 and 721,495 are referred to.