| abstract |
A carboxylic acid or sulfonic acid salt containing a plurality of carbonyl groups, and a surfactant represented by the following formula:n nR 1 —C(═O)—R 2 —C(═O)—R 3 -An nwherein R 1 , R 2 and R 3 are as defined herein, and A is —COOX or —SO 3 X, wherein X is H, a metal atom, NR 4 4 , imidazolium optionally containing a substituent, pyridinium optionally containing a substituent, or phosphonium optionally containing a substituent, where R 4 s are each H or an organic group and are the same as or different from each other; and any two of R 1 , R 2 , and R 3 optionally bind to each other to form a ring. |