R1???{(O???R2)k???OCONH???R3[???NHCOO???(R4???O)n???R5]h}m???(1) wherein R1, R2 and R4 each is a hydrocarbon group, which may be the same or different each other, R3 is a hydrocarbon group, which may have urethane bond; R5 is a straight chain hydrocarbon group, m is an integer of 2 or more; h is an integer of 1 or more; and k and n each is an integer within the range of 0 to 1000, respectively.