Substrate having high initial water repellency and a laundry durable water repellency

A fibrous substrate having high initial water repellency and laundry-durable water repellency comprising a fibrous material and a treatment, wherein the treatment is applied to the substrate at an amount of no more than about 0.4 weight percent, based on the weight of the substrate without treatment, and the treatment of a composition comprises:

• (A) a fluorochemical oil- and water-repellent agent selected from the group consisting of Rf-containing polyisocyanates with one or more blocked isocyanate groups, Rf-containing carbodiimides, Rf-containing melamines, and copolymers of fluorochemical acrylates or methacrylates with copolymerizable, fluorine-containing or hydrophobic, fluorine-free comonomers;
• (B) a copolymer extender comprising:
• (i) polymerized units derived from a monomer of formula:
• CR1R2═CR3R4
• wherein each of R1, R2, R3, and R4 independently represents hydrogen, halogen, or an organic group;
• and
• (ii) polymerized units derived from a monomer of formula:
• CH2═CR5X
• wherein R5 represents a hydrogen atom or a methyl group, and X represents a moiety comprising a functional group that can interact with a fibrous substrate;
• and
• (C) a blocked isocyanate extender.