| abstract |
A fluorine-containing polyether of the formula: n n A--X--A' n n wherein A and A' are the same or different and are each --COF, --COCl or --COOH, and X is --CF 2 CF 2 --R f --O--C m F 2m --O--R f 'CF 2 CF 2 -- in which R f and R f ' are the same or different and are each a group containing a perfluoroalkylpolyether group, and m is a number of from 1 to 6, and a fluorine-containing polyether of the formula: n n Z--X.sub.n --Z' n n wherein X is the same as defined above, Z and Z' are the same or different and are each --COF, --COCl, --COOH or --CF 2 CF 2 --R f --B in which R f is the same as defined above and B is a fluorine atom or a C 1 -C 5 perfluoroalkyl group, and n is a number of from 0 to 100 provided that when n is 1, Z and Z' are each --CF 2 CF 2 R f B, provided that when n is 0, both Z and Z' are each --CF 2 CF 2 R f B or when n is 1, at least one of Z and Z' is --CF 2 CF 2 R f B. |