GB613939A - Manufacture of cupriferous disazo-dyestuffs - Google Patents

Abstract

Cupriferous disazo dyestuffs are manufactured by the action of an agent yielding copper on an asymmetrical disazo-dyestuff of the general formula <FORM:0613939/IV (c)/1> wherein R represents the residue of a dihydroxynaphthalene monosulphonic acid bound to the azo group in a position vicinal to a hydroxy group, and R1 represents the residue of a monohydroxynaphthalenesulphonic acid bound to the azo group in a position vicinal to the hydroxy group and free from amino and substituted amino groups. The treatment may be carried out under relatively mild or relatively intense conditions depending on whether it is desired to hydrolyse the methoxy groups. The products dye cellulose (e.g. cotton or regenerated cellulose) in blue tints. Suitable components for the preparation of the starting materials are, on the one hand (corresponding to R), 1 : 3 : 6-, 1 : 6 : 3-, 1 : 6 : 4-, 1 : 8 : 4-, 2 - 6 : 4-, 2 : 7 : 3- and especially 1 : 7 : 4-and 2 : 8 : 6- dihydroxynaphthalenesulphonic acids, and, on the other hand (corresponding to R1), 1 : 3-, 1 : 4-, 1 : 5-, 2 : 4-, 2 : 5-, 2 : 6-, 2 - 7- and 2 : 8- naphtholsulphonic acids and corresponding di- and tri-sulphonic acids. Examples describe the treatment of dyestuffs from certain of these components with ammoniacal copper solution at 85-90 DEG C., and the dyeing of cotton reddish-blue with the copper compound of the dyestuff 2 : 8-dihydroxynaphthalene - 6 - sulphonic acid \sM dianisidine --> 2 - naphthol - 6 - sulphonic acid, from a bath containing sodium carbonate and, in the later stages, sodium sulphate. The Specification as open to inspection under Sect. 91 comprises also the coppering of dyestuffs of the general formula above in which R1 may contain a second hydroxy group (iu which case it may be identical with R) or an amino or substituted amino group. A further example describes the action of ammoniacal copper solution at 85 DEG -95 DEG C. or at 50 DEG C. on the symmetrical dyestuff dianisidine --> 2 : - dihydroxynaphthalene - 6 sulphonic acid (2 mols.), and additional R1 components specified are 2 : 5 : 7 -, 1 : 8 : 4 - and 2 : 8 : 6-aminonaphtholsulphonic acids, N-methyl, N-hydroxyethyl-, N-phenyl, N-(p- and m-sulphophenyl)-, N-(p-methoxyphenyl- and N-(41-hydroxy - 31 - carboxyphenyl) - 2 : 5 : 7 - acid, 1 : 8 - aminonaphthol - 3 : 6 - and 2 : 4 - disulphonic acids and 1 : 8 - dihydroxynaphthalene - 3 : 6 - disulphonic acid. This subject-matter does not appear in the Specification as accepted.