ormula (1): wherein R1 and R2 each represent an organic group or a halogen atom, and m and n each represent an integer of 0 to 4, and when m or n is an integer of 2 to 4, R1 and R2 may be the same or different, and/or an organophosphorus compound represented by General Formula (2): wherein R1 and R2 each represent an organic group or a halogen atom, and m and n each represent an integer of 0 to 4,