. . "(wherein X represents an alkenyl group; A represents a linear or branched alkylene group having a carbon atom number of 1 to 15, which may be substituted; m represents an integer of 0 to 30, if m is a plural number, each A may be different; B represents a single bond or an alkylene group which may be substituted; D represents an aromatic ring structure which may be substituted; n represents an int" . .