. "10 hydrocarbon group, a substituted or unsubstituted monovalent aromatic group, an alkenyl group, a carboxyl group, an acyloxy group, an alkoxycarbonyl group, a nitrile group, a pyridyl group, an amide group or a glycidoxy group, and an ethylenically unsaturated compound of the formula: ##STR7## wherein R4, X, a, b and m are the same as defined above and R5 is an organic group having a ethylenical" . . .