GB329014A - Improvements in the dyeing of regenerated cellulose materials - Google Patents

Abstract

329,014. Imperial Chemical Industries, Ltd., and Brightman, R. Feb. 7, 1929. Azo dyes. - Regenerated cellulose materials, e.g. viscose silks, are dyed in level violet-blue to blue shades by the application of disazo dyes obtained by coupling with a 1: 8- or 2 : 8-aminonaphthol mono- or di-sulphonic acid, a diazoazo compound produced by diazotizing the aminoazo compounds resulting from reduction of the nitro group or hydrolysis of the acetyl group of the mono-azo dyes of the type p-nitraniline, p-aminoacetanilide, or a nuclear substitution derivative thereof, other than an alkoxy derivative # a naphthol, a naphtholsulphonic acid, or an N- substituted 2 : 8-aminonaphtholsulphonic acid. In an example the nitro group of the dyestuff 4- nitraniline # (alkaline) 8-oxy-2 : 2<1>-dinaphthylamine-3 : 6-disulphonic acid is reduced with alkaline sodium sulphide, and the aminoazo product is diazotized and coupled (alkaline) with H-acid; the product dyes viscose silk blue. In a further example, a regenerated cellulose silk is dyed a bright blue in a dyebath containing Glauber's salt, soap, soda ash, and the dyestuff obtained by coupling (alkaline) with 1 : 8-aminonaphthol- 2 : 4-disulphonic acid, the diazo compound from the aminoazo product of reduction of the dyestuff 4-nitraniline # 1 : 4-naphtholsulphonic acid. A table is also given showing the shades obtained on viscose silk with the following dyestuffs : 4-nitraniline or 2-chloro-4-nitraniline # 1 :4-naphtholsulphonic acid (reduced) # (alkaline) 1: 8-aminonaphthol-2 : 4-disulphonic acid; 4-nitraniline-2-sulphonic acid # 2-naphthol (reduced), 4-nitramline # (alkaline) benzoyl- 2 : 8 : 6-acid (reduced), 2-chloro-4-nitraniline # (alkaline) 8-oxy-2-2<1>-dinaphthylamine-3: 6-disulphonic acid (reduced), or 5-nitro-2-toluidine # 2: 7-naphtholsulphonic acid (reduced) # (alkaline) H-acid; 4-nitraniline-2-sulphonic acid # 1 : 4-naphtholsulphonic acid (reduced), or 4- nitraniline # 1: 5- or 1 3-nitraniline-2-sulphonic acid # 2-naphthol (reduced) # (alkaline) 1 : 8 : 4-acid; 4-aminoacetanilide # 2 : 6-naphtholsulphonic acid (hydrolyzed) # (alkalme) 1: 8: 4-acid; 4-nitraniline # 1: 4- naphtholsulphonic acid (reduced) # (alkaline) 2 : 8-aminonaphthol-3 : 6-disulphonic acid. A similar table in the Provisional Specification shows the shades obtained on viscose silk with the following additional dyestuffs :-4-aminoacetanilide # 8-oxy-2: 2<1>-dinaphthylamine- 3 :6-disulphonic acid (hydrolyzed) # H-acid; 4-aminoacetanilide-2-sulphonic acid # 8-oxy- 2: 2<1>-dinaphthylamine-3 : 6-disulphonic acid or phenyl-2 : 8 : 6-acid (hydrolyzed) # H-acid; 4- nitraniline # 1 : 4-naphtholsulphonic acid (reduced) # 2 : 8 : 6-acid; 4-nitraniline-2-sulphonic acid # 2-naphthol (reduced) # 1 : 8-aminonaphthol-2 : 4-disulphonic acid; 4- nitraniline-2-sulphonic acid # phenyl-2 : 8 : 6- acid (reduced) # H-acid.