GB216527A - Manufacture of azo-dyestuffs - Google Patents

Abstract

Insoluble azo dyes are produced, in substance or upon substrata, by coupling arylides of 2 : 3-oxynaphthoic acid with tetrazo compounds of certain diaminoazo dyestuffs not containing sulphonic groups; such diaminoazo compounds are obtainable by coupling a tetrazo compound with a diazotizable amine such as m-aminoacetanilide, acetyltoluylenediamine, m-toluidine, p-cresidine, p-xylidine, or a -naphthylamine or a derivative coupling in the 4-position; two different amines may be employed. The following examples are given:-(1) tetrazotized dianisidine is coupled with a -naphthylamine, again tetrazotized, and coupled with 2 : 3-oxynaphthoic anilide; the product yields black lakes: (2) fibre impregnated with 2 : 3-oxynaphthoic-a -naphthalide is dyed bluish- or greenish-black by developing with the tetrazo compound of the dyestuff from tetrazotized tolidine, a -naphthylamine, and p-cresidine or that from tetrazotized p : p1-diaminodiphenylamine and p-cresidine: (3) fibre impregnated as in (2) is developed with the tetrazo compound of the dyestuff made by coupling p-cresidine with tetrazotized 4 : 41-diamino-2 : 31-dimethoxy-21-methyl-azobenzene (made by coupling diazotized 1-amino-2-methoxy-4-nitro- or 4-acetylaminobenzene with p-cresidine and reducing or hydrolyzing): (4) goods impregnated with 2 : 3-oxynaphthoic anilide are printed with a thickened tetrazo solution of the dyestuff from tetrazotized tolidine and p-cresidine. 4-Amino-3-methoxy-acetanilide is obtained by reduction of the corresponding nitro compound.ALSO:Insoluble azo dyes are produced, upon the fibre, by coupling arylides of 2 : 3-oxynaphthoic acid with tetrazo compounds of certain diamino-azo dyestuffs not containing sulphonic groups; such diamino-azo compounds are obtainable by coupling a tetrazo compound with a diazotizable amine such as m-aminoacetanilide, acetyltoluylene-diamine, m-toluidine, p-cresidine, p-xylidine, or a -naphthylamine or a derivative coupling in the 4-position; two different amines may be employed. The following examples are given:-(1) fibre impregnated with 2 : 3-oxynaphthoic-a -naphthalide is dyed bluish-or greenish-black by developing with the tetrazo compound of the dyestuff from tetrazotized tolidine, a -naphthylamine, and p-cresidine or that from tetrazotized p : p1-diaminodiphenylamine and p-cresidine: (2) fibre impregnated as in (1) is developed with the tetrazo compound of the dyestuff made by coupling p-cresidine with tetrazotized 4 : 41-diamino-2 : 31-dimethoxy-21-methyl-azobenzene (made by coupling diazotized 1-amino-2-methoxy-4-nitro- or 4-acetylamino benzene with p-cresidine and reducing or hydrolyzing: (3) goods impregnated with 2 : 3-oxynaphthoic anilide are printed with a thickened tetrazo solution of the dyestuff from tetrazotized tolidine and p-cresidine.