Patent ID: 6858573

Claim:
An anionic surfactant of the formula (1): R 2 —Y—(O)C—(HR)C—C(HR 1 )—C(O)—(OA) n —X (I)* wherein one of R and R 1 is a C 6 to C 22 linear or branched alkyl or alkenyl, and the other is hydrogen; Y is O, or NH, or —NH—CH 2 —C(═CH 2 )—, or —N(CH 2 —CR 3 (═CH 2 ))—CH 2 —C(═CH 2 )— where R 3 is hydrogen or methyl; when Y is O, R 2 is hydrogen, or a salt, or a C 1 to C 6 linear or branched alkyl, or an optionally substituted C 3 to C 10 linear or branched alkenyl; when Y is NH, or —NH—CH 2 —C(═CH 2 )—, or —N(CH 2 —CR 3 (═CH 2 ))—CH 2 —C(═CH 2 )— where R 3 is hydrogen or methyl, R 2 is hydrogen or methyl; OA is an oxyalkylene group; n is 2 to 100; and X is a group comprising at least one acidic H atom, or a salt thereof.