Fluorochemical composition for treatment of a fibrous substrate

A fluorochemical composition comprising a dispersion or a solution of a fluorinated compound, wherein said fluorinated compound comprises the reaction product of a combination of reactants comprising:

• (i) one or more fluorinated polyethers according to the formula:
• RfQTk (I)
• wherein Rf represents a monovalent perfluorinated polyether group having a number average molecular weight of at least 750 g/mol, Q represents a chemical bond or a divalent or trivalent organic linking group, T represents a functional group capable of reacting with an isocyanate, and k is 1 or 2;
• (ii) one or more polyoxyalkylene diols;
• (iii) one or more short chain perfluoroalkyl alcohols;
• (iv) one or more isocyanate component selected from a polyisocyanate compound that has at least 3 isocyanate groups or a mixture of polyisocyanate compounds wherein the average number of isocyanate groups per molecule is more than 2;
• (v) optionally one or more isocyanate blocking group;
• and
• (vi) optionally one or more co-reactants capable of reacting with an isocyanate group;
• wherein less than about 15% of the isocyanate groups are reacted with said fluorinated polyether, at least about 5% of the isocyanate groups are reacted with said polyoxyalkylene diol, at least about 35% of the isocyanate groups are reacted with said short chain perfluoroalkyl alcohol, and less than about 15% of the isocyanate groups are reacted with said isocyanate blocking group.