GB745641A - Manufacture of cobaltiferous and chromiferous azo-dyestuffs - Google Patents

Abstract

The invention comprises chromium and cobalt complexes containing one or more o:o1 - dihydroxymonoazo dyestuffs so bound in complex union that the ratio of the number of chromium or cobalt atoms to the number of dyestuff molecules is smaller than 1:1 (preferably 1:2), the dyestuff or dyestuffs being of the benzeneazo-naphthalene series and free from sulphonic and carboxylic acid groups, and corresponding (or at least one of them corresponding) to the general formula:- <FORM:0745641/IV(c)/1> (wherein X represents hydrogen, halogen or a nitro, alkyl or acylamino group, Y represents a sulphonic acid amide group, and Z represents hydrogen, halogen or an alkyl, alkoxy or sulphonic acid ester group, at most one of X and Z representing hydrogen when Y represents an unsubstituted sulphonic acid amide group), and the manufacture thereof by (a) treating the appropriate dyestuff or mixture of dyestuffs with an agent yielding chromium or cobalt in such manner that the resulting complex contains less than one atom of chromium or cobalt per molecule of dyestuff, or (b) reacting a complex, containing one atom of chromium combined with one molecule of an o : o1-dihydroxymonoazo dyestuff of the benzene-azo-naphthalene series free from sulphonic and carboxylic acid groups, with a metal-free dyestuff of the said type, at least one of the reactants being, or being derived from a dyestuff of formula (I). Process (a) may be carried out by using less than one atomic proportion of metal for each molecular proportion of dyestuff, and/or by working in a weakly acid to alkaline medium, advantageously with the use of complex chromium or cobalt compounds of aliphatic hydroxycarboxylic or dicarboxylic acids or chromium compounds of aromatic o - hydroxycarboxylic acids, though simple bivalent cobalt compounds are also suitable. The dyestuffs of formula (I) are obtainable by coupling, advantageously in alkaline medium, of appropriate components, of which many are listed. When the complex contains a dyestuff not of formula (1), this preferably corresponds to one of the general formula:- <FORM:0745641/IV(c)/2> (wherein R represents a residue of the benzene series bound to the azo linkage in ortho-position to a hydroxy group). Components for making these dyestuffs are also listed. The metalliferous products are suitable for dyeing silk, leather, wool and synthetic superpolyamide or superpolyurethane fibres, with reservation of viscose and cellulose acetate effect threads, advantageously from weakly alkaline, neutral or weakly acid baths. In examples :(1) and (2) the dyestuff 2-aminophenol-4- or -5-sulphonic acid amide --> 6-bromo-2-naphthol is heated with cobalt sulphate in aqueous caustic soda; (3) the dyestuff 2-aminophenol-4-sulphonic acid methylamide --> b -naphthol is boiled with a solution of potassium sodium chromosalicylate; (4) the dyestuff of (3) is treated as in (1); a table gives the properties of the chromium complex of the dyestuff of (2) and the chromium and cobalt complexes from the following further dyestuffs: 2 - aminophenol - 5 - sulphonic acid amide --> 6 - methoxy - and 6 - methyl - 2 - naphthol; 2 - aminophenol - 4 - sulphonic acid isopropylamide, dimethylamide, mono - and di - (b - hydroxmethyl) - amide, anilide and pyrrolidide, 4 - chloro - 2 - aminophenol - 5 - and - 6 - sulphonic acid amide, 6 - chloro - and 6 - nitro - 2 - aminophenol - 4 - sulphonic acid amide, 4 - methyl - 2 - aminophenol - 5 - sulphonic acid amide, 2 - aminophenol - 5- sulphonic acid methylamide, and 4 - nitro - 2 - aminophenol 6 - sulphonic acid amide --> b - naphthol; and 2 - aminophenol - 4 - sulphonic acid amide --> 2 - naphthol - 6 - and - 7 - sulphonic acid phenyl ester; (5) an equimolecular mixture of the dyestuffs 2 - aminophenol - 4 - sulphonic acid methylamide and anilide --> b - naphthol is boiled with a solution of sodium chromosalicylate, or converted to a cobalt complex as in (1); the properties of further mixed complexes are tabulated; (6) a mixture of two molecular proportions of the dyestuff of (3) and one each of the dyestuffs 4 - and 5 - nitro - 2 - aminophenol --> 1 - acetylamino - 7 - naphthol is chromed as in (5); (7) wool or nylon is dyed with the product of (2), with or without the addition of acetic acid to the bath. The products of Specification 687,253 are disclaimed, whilst Specifications 126,460 [Class 15(ii)] 343,014, 637,404, 693,245 and 709,495 and U.S.A. Specification 1,984,096 also are referred to.