Patent ID: 6841655

Claim:
A surfactant represented by the following formula (1): wherein R 1 represents a branched aliphatic hydrocarbon group, or a branched aliphatic acyl group, which branched aliphatic hydrocarbon group or branched aliphatic acyl group has 8 to 36 carbon atoms and contains at least three methyl groups, AO and AO′ each independently represents an oxyalkylene group having 2 to 4 carbon atoms, L represents a group represented by formula (2) to be described below, z stands for a number of from 1 to 10, X represents a hydrogen atom or an ionic hydrophilic group, m stands for a number of from 0 to 1,000, and n stands for a number of from 0 to 1,000; wherein R 2 and R 3 each independently represents a hydrogen atom or a methyl group, x stands for a number of from 0 to 12, and y stands for a number of 0 or 1.