. "PC is preferably a compound which can be easily prepared by reaction of a dihydric phenol represented by the general formula (IX): ##STR13## wherein R11 and R12 are, respectively, a halogen atom, such as a chlorine atom, a bromine atom, a fluorine atom and a iodine atom, or an alkyl group having 1 to 8 carbon atoms and may be the same or different from each other, f and g are, respectively, an int" . . . . . .