Patent ID: 7683199

Claim:
A fluorine-containing polyether phosphonic acid ester compound, represented by the following general formula: (R 2 O)(R 1 O)P(O)(CH 2 ) a CF(CF 3 )[OCF 2 CF(CF 3 )] b O(CF 2 ) C O[CF(CF 3 )CF 2 O] d CF(CF 3 )(CH 2 ) e P(O)(OR 3 )(OR 4 ), where R 1 , R 2 , R 3 and R 4 are hydrogen atoms, alkyl groups, cycloalkyl groups, aryl groups, alkylaryl groups, aralkyl groups or any of the foregoing groups, some or whole of whose hydrogen atoms are substituted with halogen atoms, and subscripts a, b, c, d, and e are integers satisfying conditions of 2≦a+e≦8, b+d≦28 and 1≦c≦10, and the subscripts b and d may be 0).