| abstract |
1. Metal complex formazan dyestuffs which in the acid form are represented by the formula: <IMAGE> (1) 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 SO3H, PO3H2, CO2H, CN, NO2, NH2, acetylamino, benzoylamino, OH, F, Cl, Br, C1-4 alkyl, C1-4 alkoxy, sulphonamido, <IMAGE> wherein Y = CO or SO2 and n=0 or 1 or H2O3P-CH2CH2-NH-Y- wherein Y = CO or SO2; D is NO2, CN, COOH, SO3H, C1-4 alkyl, C1-4 alkyl substituted by PO3H2; C1-4 alkenyl, styryl, pyridyl, furyl, COCH3, CO6H5, naphthyl, phenyl or phenyl substituted by at least one group selected from COOH, NH2, CN, F, Cl, Br, acetylamino, benzoylamino, OH, methyl, methoxy, SO3H and PO3H2; X1 and X2 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. |