R3O(CH2CH2O)kCH2COO???M+ wherein R3 is a C10 to C15 alkyl or alkenyl group, preferably a C11-C15, more preferably a C12-C14 alkyl or C12-C13 alkyl group, k is an average value of ethoxylation ranging from 2 to about 7, preferably from about 3 to about 6, more preferably from about 3.5 to about 5.5, especially from about 4 to about 5, most preferably from about 4 to about 4.5, ??? and M is a water-