High performance water and oil repellant

A high performance water and oil repellant having a molecular weight of from 800 to 20,000 of the formula:

• ##STR31## wherein R.sub.f is a perfluoroalkyl group of the formula C.sub.n F.sub.2n+1, X is --R--, --CON(R.sup.1)--Q-- or --SO.sub.2 N(R.sup.1)--Q--, each of A, A.sup.1 and A.sup.2 is --O--, --S-- or --N(R.sup.2)--, [Z] Z--A.sup.1 is a monovalent alcohol, thioalcohol or primary or secondary amine residue, a is an integer of from 1 to 5, b is an integer of from 0 to 4, a +b is an integer of from 1 to 5, W is a t-valent organic residue obtained by removing the t --NCO groups from a t-functional aliphatic, cycloaliphatic, aromatic or heterocyclic isocyanate compound having t --NCO groups, wherein t is an integer of a +b +1, B is a bivalent organic residue obtained by removing the two --A.sup.2 --H groups from a bifunctional polyvalent active hydrogen compound, and wherein B may have another organic group bonded by A.sup.2, Y is a bivalent organic residue obtained by removing the two --NCO groups from a bifunctional aliphatic, cycloaliphatic, aromatic or heterocyclic isocyanate compound, and wherein Y may have another organic group bonded by a --NHCO-- group, m is an integer of from 1 to 50, R is a bivalent alkylene group, R.sup.1 is a hydrogen atom or a lower alkyl group, Q is a bivalent alkylene group, R.sup.2 is a hydrogen atom or a monovalent aliphatic, cycloaliphatic, aromatic or heterocyclic group, or Z and R.sup.2 may form a ring.