Fluorochemical composition comprising a polyurethane having fluorochemical oligomer and a hydrophilic segment to impart stain release properties to a substrate

摘要

The present invention provides a method for preparing a fluorochemical composition comprising polyurethane by reacting: (A) fluorochemical oligomer of formula (I): MfmMn-Q1-T1 wherein: MfmMn represents flurochemical oligomer comprising m units derived from fluorinated monomer and n units derived from fluorine-free monomer and wherein the fluorinated monomers and fluorine-free monomers may be the same or different; m represents a value of 2 to 40; n represents a value of 0 to 20; T1 is -OH or -NH2; Q1 and T1 together represent an organic residue obtained by removing a hydrogen atom from a chain transfer agent that is functionalized with T1; and (B) difunctional compound capable of reacting with an isocyanate and comprising a poly(oxyalkylene) group having 18 to 280 oxyalkylene moieties with (C) diisocyanate or triisocyanate. Substrates treated with the fluorochemical composition prepared according to the method described above, have good stain release properties in particular for oily stains and water based stains such as wine, tea and coffee.