. . . "wherein R7 is hydrogen, fluorine, methyl or trifluoromethyl; R8 is a single bond or a straight, branched or cyclic C1-C4 alkylene group which may have an ether group; R9 and R11 each are hydrogen or methyl; R10 is a C1-C10 alkylene group; R12 is a single bond or a straight, branched or cyclic C1-C4 alkylene group; X is a carboxyl or sulfo group; Y is ???O??? or ???NH??? ; m is an integer of 0 to 1" .