GB469562A - Process for the manufacture of polyazodyestuffs - Google Patents

Abstract

Polyazo dyes are made by coupling a diazo or diazoazo compound with a p-coupling amine, and if the amine is of the naphthalene series, free from hydroxy or substituted hydroxy groups, further diazotizing, coupling with an aminoaroylaminonaphthol mono or disulphonic acid, further diazotizing and coupling with an aminoaryl pyrazolone. They may be further diazotized and coupled in substance or the fibre or after-treated on the fibre with diazo compounds. Brown shades of good dischargeability are obtained. In examples, the following dyes are described: (1) m-xylidine-o-sulphonic acid --> cresidine --> N-p-aminobenzoyl J-acid --> 1-m-aminophenyl-5-pyrazolone-3-carboxylic acid or 1-p-aminophenyl-3-methyl-5-pyrazolone; the former when diazotized on the fibre and developed with b -naphthol or m-phenylenediamine or treated on the fibre with diazotized p-nitraniline gives brown shades and the latter when diazotized on the fibre and developed with m-phenylenediamine gives reddish brown shades; (2) Cleves' acid is used instead of cresidine; (3) and (4) p-aminobenzoyl-2 : 8 : 6- or 1 : 5 : 7-acid is used instead of the J-acid derivative; (5) 2-naphthylamine-4 : 8-disulphonic acid --> m-toluidine --> o-toluidine --> N-p-aminobenzoyl J-acid --> 1 - m - aminophenyl - 5 - pyrazolone - 3 - carboxylic acid --> (on the fibre) m-phenylenediamine; (6) N-p-aminobenzoyl H-acid is used instead of the J-acid compound in (5); (7) 2-naphthylamine-4 : 8-disulphonic acid --> p-xylidine --> cresidine --> N-p-aminobenzoyl J-acid --> 1-m-aminophenyl-5-pyrazolone-3-carboxylic acid --> (on the fibre) m-phenylenediamine; (8) 2-naphthylamine-8-sulphonic acid --> cresidine --> N-p-aminobenzoyl J-acid --> 1-m-aminophenylpyrazolone-3-carboxylic acid --> (on the fibre) m-phenylene diamine. Specifications 28718/09, 8996/15, 259,970, and 320,030, [all in Class 2 (iii)], are referred to.