CH2O)l??? or (CH2CH(CH3)O)m???, the sum of l and m is 8 or less when R3 represents the combination of ???(CH2CH2O)l??? and ???(CH2CH(CH3)O)m???, and X1 represents a carboxy group or a sulfone group, R4-Z-Y1???X2???(2) R4-Z-X2???(3) in general formulas (2) and (3), R4 represents an alkyl group having 8 to 16 carbon atoms, Z is a functional group represented by chemical formula (i) or (ii), Y repres