e where m=n=1 and Ar1 and Ar2 are symmetrically bonded to the benzene rings, Ar1 and Ar2 are not the same, and in the case where m or n is an integer of 2 to 4, m is different from n, R31 to R40 are independently a hydrogen atom, a substituted or unsubstituted aromatic ring group having 6 to 50 nucleus carbon atoms, a substituted or unsubstituted aromatic hetrocyclic group having 5 to 50 nucleus a