Patent ID: 6923921

Claim:
A fluorochemical composition comprising a fluorinated polyether having a molecular weight between about 750 g/mol and about 4000 g/mol, said fluorinated polyether being substantially free of fluorinated polyethers having a molecular weight of less than 750 g/mol and greater than 4000 g/mol, and wherein said fluorinated polyether is of the formula: R f 1 —[O—[CF(CF 3 )—CF 2 O] n —CF(CF 3 )-Q-T k ] y wherein R f 1 represents a perfluorinated alkyl or alkylene group, n is an integer of 3 to 23, Q is an organic divalent or trivalent linking group selected from the group consisting of alkylene, oxyalkylene, aminoalkylene, and carboxyalkylene and T is selected from the group consisting of —OH, —SH, NH 2 , —C(O)F, —CO 2 R 3 , where R 3 is hydrogen, lower alkyl, cycloalkyl or alkanol, and —C(O)N(R 1 )(R 2 ), where R 1 and R 2 are independently lower alkyl, cycloalkyl or alkanol; k is 1 or 2, and y is 1 or 2.