. . "Here, the bivalent phenol of the formula (7) is a bivalent phenol in which R1, R2, R7 and R8 may be the same or different and are a halogen atom, an alkyl group having 6 or less carbon atoms or a phenyl group, R3, R4, R5 and R6 may be the same or different and are a hydrogen atom, a halogen atom, an alkyl group having 6 or less carbon atoms or a phenyl group and A is a linear, branched or cyclic h" . . . . . . . . .