A need has existed for fibrous polyamide and wool articles having properties of stain resistance to natural and artificial acid colorants and light-fastness that are more durable against alkaline washing than those currently available in the art. Several processes are known to impart stain resistance and lightfastness. For example, Olson et al., U.S. Pat. No. 4,822,373 (whose disclosure is incorporated herein by reference) describes treating polyamide fibers with an aqueous solution of a) a partially sulfonated Novolak resin and b) polymethacrylic acid, copolymers of methacrylic acid, or combinations of polymethacrylic acid and the copolymers of methacrylic acid. Such a treatment imparts stain resistance and lightfastness to the fibrous polyamide material. However, there remains a need to increase the durability of these stain resistance and lightfastness properties against the effects of aqueous alkaline solutions to which those materails are subjected during laundering.
USPTO Backgrounds
USPTO Backgrounds