. . "The hydrazone compound may be represented by the formula II!: ##STR3## wherein R1, R2, R3, and R4 are groups selected from an alkyl group, an aralkyl group, and an aryl group, respectively, which may be substituted; and R5 is an atom or a group selected from a hydrogen atom, a halogen atom, an alkyl group, and an alkoxy group, and R1 and R2 may be bound together to form a ring, and also R1 or R2 m" . .