R2, R3, R4 and R5) each independently are a hydrogen atom, a chlorine atom, a hydroxyl group, an alkyl group having a carbon number of 1-25, a phenylalkyl group having a carbon number of 7-9, an unsubstituted or an (alkyl having a carbon number of 1-4)-substituted phenyl group, an unsubstituted or an (alkyl having a carbon number of 1-4)-substituted cycloalkyl group having a carbon number of 5-8,