WATER-SOLUBLE DISAZO DYESTUFFS AND THEIR COMPLEX METAL COMPOUNDS

The invention comprises water-soluble disazo dyes of the general formula wherein D1 and D2 are benzene or naphthalene radicals; R is H or an aliphatic or araliphatic radical; X is a sulphonyl or carbonyl group; Y is halogen or hydroxy or an inorganic polybasic acid radical; Ar is a benzene or naphthalene radical containing at least one sulphonic acid group; R1 is H; R2 is an alkyl, aryl, carboxyl or carboxylic acid ester radical; n is 1 or 2; m1, m2, m3 and m4 are 0, 1 or 2 and the sums m1 + m2 and m3 + m4 being at most 2; the sum m1 + m2 + m3 + m4 being at least 1 and their copper, cobalt, chromium, nickel and iron complexes. They are prepared by coupling two mols of the same or different benzene or naphthalene diazo component, at least one of which contains at least once the group and R being as above, simultaneously or consecutively with 1 mol of a pyrazolone of the formula Ar and R2 being as above and R1 is H or a radical of an organic acid, the second mol of diazo component being reacted only after organic acid radical R1 has been hydrolysed. When Y in the product dyes is -OH this group may be esterified with a polybasic acid or a monoamide or mono-chloride thereof. The ester groups may be hydrolysed to form vinyl groups using alkali. The dyes may be metallized and if the dyes contain groups capable of being converted into metallizable groups oxidizing conditions are used. The dyes give brown and red shades on cellulosic, wool, silk and polyamides.