Patent ID: 7981932

Claim:
A compound consisting of a salt of a mono- and/or di-2-propylheptyl ester of a sulfonated dicarboxylic acid corresponding to formula (I): R 1 O 2 C—CH 2 —CH(SO 3 M 1 )—CO 2 R 2 (I) wherein M 1 is a cation, and R 1 and R 2 independently have the same meaning as M 1 , or represent an alkyl group selected from the group consisting of n-C 5 H 11 CH(C 3 H 7 )CH 2 —, C 2 H 5 CH(CH 3 )CH 2 CH(C 3 H 7 )CH 2 —, and CH 3 CH(CH 3 )CH 2 CH 2 CH(C 3 H 7 )CH 2 —, wherein not more than one of the substituents R 1 and R 2 may be M 1 .