Transition metal complex formazan dyestuffs containing at least one phosphonic acid group

Abstract

1. Metal complex formazan dyestuffs which in the acid form are represented by the formula: ##STR1## wherein A and B are each selected from phenylene, naphthalene, substituted phenylene or substituted naphthalene groups, said substituted phenylene or substituted naphthalene groups containing at least one group selected from SO.sub.3 H, PO.sub.3 H.sub.2, CO.sub.2 H, CN, NO.sub.2, NH.sub.2, acetylamino, benzoylamino, OH, F, Cl, Br, C.sub.1-4 alkyl, C.sub.1-4 alkoxy, sulphonamido, ##STR2## wherein Y = CO or SO.sub.2 and n=0 or 1 or H.sub.2 O.sub.3 P--CH.sub.2 CH.sub.2 --NH--Y-- wherein Y = CO or SO.sub.2 ; D is NO.sub.2, CN, COOH, SO.sub.3 H, C.sub.1-4 alkyl, C.sub.1-4 alkyl substituted by PO.sub.3 H.sub.2 ; C.sub.1-4 alkenyl, styryl, pyridyl, furyl, COCH.sub.3, CO.sub.6 H.sub.5, naphthyl, phenyl or phenyl substituted by at least one group selected from COOH, NH.sub.2, CN, F, Cl, Br, acetylamino, benzoylamino, OH, methyl, methoxy, SO.sub.3 H and PO.sub.3 H.sub.2 ; X.sup.1 and X.sup.2 are both 0 or one is 0 and the other is COO; and M is Ni, Co, Cr and Cu; at least one of A and B and D if an aliphatic or aromatic radical, bears one or more phosphonic acid groups. The dyestuffs are useful for coloring cellulose by heating in the presence of carbodiimides.

Dependencies are inferred from the claim text.