A compound represented by a free acid of the formula, ##STR90## wherein A.sub.1 and A.sub.2 are independently phenylene unsubstituted or substituted with one substituent selected from the group consisting of chlorine, bromine, nitro, methyl ethyl, methoxy, ethoxy sulfonyl, N,N-dimethylsulfamoyl, B is phenyl unsubstituted or substituted with one or two members selected from the group consisting of chlorine, methyl ethyl, methoxy, ethoxy, carbomethoxy, carboethoxy, and nitro, Me is a copper ion, X is --O--, or ##STR91## Y is fluorine or chlorine, Z is sulfonic acid, carboxylic acid or phorphoric acid, each of l, m and and n is 0 or an integer of 1 to 3, provided that the sum of I, m and n is from 2 to 3, D is phenylene unsubstituted or substituted with one or two members selected from the group consisting of methyl, ethyl, methoxy, ethoxy, chlorine and bromine, or nephthylene unsubstituted or substituted with sulfonic acid group, R is lower alkyl unsubstituted or substituted with hydroxy, carboxy, sulfo, carbamoyl, cyano or methoxycarbonyl, and Q is --SO.sub.23 CH.dbd.CH.sub.2 or --SO.sub.2 CH.sub.2 CH.sub.2 OSO.sub.3 H.