Patent ID: 8361215

Claim:
An emulsifier comprising, as an active ingredient, a polyfluoroalkylphosphonic acid salt represented by the general formula: C n F 2n+1 (CH 2 CF 2 ) a (CF 2 CF 2 ) b (CH 2 CH 2 ) c P(O)(OM 1 )(OM 2 ) [I] wherein M 1 is a hydrogen atom, an alkali metal, an ammonium base, or an organic amine base, M 2 is an alkali metal, an ammonium base, or an organic amine base, n is an integer of 1 to 6, a is an integer of 1 to 4, b is an integer of 1 to 3, and c is an integer of 1 to 3.