. . . "The acrylic acid derivative can be selected from a carboxylic acid represented by CH2???CH(R4)CO2H, an acid halide represented by CH2???CH(R4)COX1 (in which X1 is a halogen atom, such as a fluorine atom, a chlorine atom, a bromine atom, or iodine atom, preferably a chlorine atom; and R4 is as defined in formula (VI)), or an acid anhydride represented by [(CH2???CH(R4)CO)2]O (R4 is as defined in fo" . . .