GB445032A - Manufacture of azo-dyestuffs containing chromium - Google Patents

Abstract

Azo dyes containing chromium are made by treating with an agent yielding chromium an azo dye containing at least one sulphonic acid group and obtainable by coupling a diazotized 3-halogen-2-aminobenzene-1-carboxylic acid or a nuclear substitution product thereof containing no sulphonamide group with a 3-methyl-5-pyrazolone containing no salicylic sulphone group. They yield fast level yellow shades on animal fibres. In examples, chromium compounds of dyes from the following components are described: 2-amino-3-chloro-5-sulphobenzoic acid, 2-amino-3-chlorobenzoic acid; 1-(4<1>-or 3<1>-sulpho)-, 1-(2<1>-chloro-5<1>-sulpho)-, 1-(2<1> : 5<1>-dichloro-4<1>-sulpho)-, 1 - (2<1> : 5<1>- or 2<1> : 4<1>- or 3<1> : 4<1>-disulpho)-, 1 - (2<1>-p-sulphophenoxy - 5<1>-sulpho)-, 1 - (2<1>-phenylsulphone - 5<1>-sulpho)-and 1-(2<1>-phenoxy-5<1>-sulpho)-phenyl-3-methyl-5-pyrazolone, 3-methyl-5-pyrazolone. Chroming agents specified are chromium chloride, fluoride, formate and acetate. Specification 408,491 is referred to. The Specification as open to inspection under Sect. 91 comprises the manufacture of chromium compounds of the azo dyes from a diazotized 3-halogen-2-aminobenzoic acid and a 3-methyl-5-pyrazolone and containing at least one sulpho group. The following pyrazolones are also specified: 1 - (2<1> - sulpho)-, 1 - (4<1> - chloro - 2<1> - sulpho)-, 1 - (2<1> : 4<1> - dimethyl - 6<1> - sulpho) and 1 - (4<1> - methyl - 2<1> - sulpho) - phenyl - 3 - methyl - 5 - pyrazolone. This subject-matter does not appear in the Specification as accepted.