Patent ID: 7214470

Claim:
A fluorine-containing ethylenic monomer having hydroxyl represented by the formula (1a): wherein X 1 and X 2 are the same or different and each is H or F; X 3 is H, F, Cl or CF 3 (at least one of X 1 , X 2 and X 3 is H and X 1 , X 2 and X 3 are not H at the same time); Rf 1 and Rf 2 are the same or different and each is a perfluoroalkyl group having 1 to 20 carbon atoms; Rf 3 is a fluorine-containing alkylene group having 1 to 40 carbon atoms or a fluorine-containing alkylene group having ether bond which has 1 to 100 carbon atoms and the sum of carbon atom and oxygen atom of two or more; a is 1.