Process for fixing dyes in textile materials

A fine-dimensional yarn fabric made from the group consisting of a polyamide-containing substrate, a segmented polyester-polyurethane substrate, and combinations thereof treated with a dye and an aqueous dye-fixative composition comprising

• (a) polymethacrylic acid or
• copolymers of methacrylic acid comprising from about 20% to about 30 weight percent methacrylic acid, or combinations thereof, and wherein the lower 90 weight percent of the polymethacrylic acid, or copolymers of methacrylic acid, or combinations thereof have a weight average molecular weight in the range of about 2500 to 250,000 and a number average molecular weight in the range of about 500 to 20,000, and
• (b) 3% to 5% by weight of sulfamic acid,
• and wherein said aqueous dye-fixative composition is provided in a sufficient amount and has a solubility such that said dye is fixed to said substrate, said substrate having a colorfastness value of at least about 4.0 obtained according to AATCC Test Method 107-1991, and a stain resistance value of less than 5 obtained according to AATCC Test Method 175-1993.

A process for fixing a dye to a dyed fine-dimensional yarn fabric made from the group consisting of a polyamide-containing substrate, segmented polyester-polyurethane substrate, and combinations thereof, comprising contacting said fabric with an aqueous solution comprising a dye-fixative composition substantially free of phenol and formaldehyde residues, said dye-fixative composition comprising (1) a copolymer of:

• a) about 1 to about 20 percent by weight of vinyl sulfonic acid residues,
• b) about 5 to about 20 percent by weight of nonpolar or hydrophobic monomer residues, and
• c) about 60 to about 94 percent by weight of hydrophilic ethylenically unsaturated carboxylic acid residues, the copolymers having a weight average molecular weight of from about 1,500 to about 15,000;
• and (2) about 4% to about 10% by weight of sulfamic acid, said contacting step being for a time sufficient so that said dye-fixative composition is absorbed by said fabric.