ms, or phenyl radicals and the radicals represented by R11 and R12 may be identical to or different from each other, X is a hydrogen or halogen atom, Y is an amino group, maleimido group, glycidylamino group, or alkylamino group of from 1 to 5 carbon atoms and m1, m2, and m3 are positive integers and the sum of m1 +m2 +m3 has a value of 5.