GB342807A - The manufacture of acid disazodyestuffs - Google Patents

Abstract

Disazodyes are made by combining the tetrazo compound of p-p1-diaminodiphenylmethane, p-p1-diaminotriphenylmethane, p-p1-diaminodiphenyldimethylmethane or their derivatives substituted in the aryl residues with two molecular proportions of combining components of which one at least is 2 : 8-dihydroxynaphthalene-6-sulphonic acid or a monoarylsulphonic acid ester of this acid. When the acid is used the dyestuff may further be esterified with an arylsulphochloride. In examples, (1) 4-41-diaminodiphenylmethane \sQ (in alkaline solution) 2 - 8 - dihydroxynaphthalene - 6 - sulphonic acid to give a dyestuff dyeing wool red shades; the dyestuff may further be esterified with p-toluenesulphochloride to give a dye which dyes wool yellowish-red shades; a similar product is obtained by using as a coupling component the monobenzenesulphonic acid ester of 2 : 8-dihydroxynaphthalene-6-sulphonic acid; (2) 4-41-diamino-3-31-dimethoxydiphenyldimethylmethane is tetrazotized and coupled in alkaline solution with one molecular proportion of 1-p-toluenesulphamino-8-hydroxynaphthalene-3-6-disulphonic acid and then with 2-8-dihydroxynaphthalene-6-sulphonic acid to give a bright claret red dyestuff; (3) 4-41-diaminodiphenylmethane \sQ 2,8-dihydroxynaphthalene-6-sulphonic acid to give a dyestuff dyeing wool red shades; the dyestuff may be further esterified to give a dyestuff of a brighter shade; (4) 4-41-diaminotriphenylmethane replaces the 4-41-diaminodiphenylmethane used in the previous example to give a red dyestuff which when esterified is brighter and yellower. Specifications 9642/89, [Class 2, Acids and salts, Organic &c.], 204,722 and 335,893, [both in Class 2 (iii), Dyes &c.], are referred to. Reference has been directed by the Comptroller to Specifications 206,831 and 244,782, [both in Class 2 (iii), Dyes &c.].