Production of dyed cotton fibers

Abstract

In a method of dyeing and finishing cotton fibers, emulsion copolymer treated cotton fibers are prepared by contacting the fibers with an emulsion copolymer and curing the copolymer under conditions to chemically anchor the emulsion copolymer to the cotton and thereby form copolymer-treated cotton fibers. The copolymer-treated cotton fibers are then contacted with a dye material under conditions sufficient to affix at least a portion of the dye material to the copolymer component of the copolymer-treated cotton fibers and produce dyed cotton fibers. Thereafter, the dyed cotton fibers are treated with a surfactant-stabilized aqueous acrylic polymer dispersion to give the fibers a worn or vintage character.

1 . A method of dyeing and finishing cotton fibers, which method comprises:
 (a) preparing emulsion copolymer treated cotton fibers by contacting the fibers with an emulsion copolymer and curing the copolymer under conditions to chemically anchor the emulsion copolymer to the cotton and thereby form copolymer-treated cotton fibers;   b) contacting said copolymer-treated cotton fibers with a dye material under conditions sufficient to affix at least a portion of said dye material to the copolymer component of said copolymer-treated cotton fibers and produce dyed cotton fibers; and   then   (c) treating the dyed cotton fibers with a surfactant-stabilized aqueous acrylic polymer dispersion.   
     
     
         2 . The method according to  claim 1 , wherein the treating (c) is conducted at a temperature of 25° C. to 80° C. for a period of at least 5 minutes. 
     
     
         3 . The method according to  claim 1 , wherein the treating (c) is conducted at a temperature of 30° C. to 60° C. for a period of 15 to 45 minutes. 
     
     
         4 . The method according to  claim 1 , wherein the acrylic polymer dispersion employed in (c) is diluted to about 0.05 to about 0.3% solids. 
     
     
         5 . The method according to  claim 1 , wherein the acrylic polymer employed in (c) is produced from a monomer composition comprising one or more (meth)alkyl acrylate monomers wherein the alkyl group has from 1 to 12 carbon atoms. 
     
     
         6 . The method according to  claim 5 , wherein the monomer composition comprises butyl acrylate, methyl methacrylate, ethyl acrylate or a mixture thereof. 
     
     
         7 . The method according to  claim 5 , wherein the monomer composition further comprises from 5 to 20% by weight, such as from 5 to 10% by weight, of acrylonitrile based on the total weight of monomers in the composition. 
     
     
         8 . The method according to  claim 1 , wherein the surfactant stabilizer for the acrylic polymer comprises an anionic surfactant. 
     
     
         9 . The method according to  claim 1  and further comprising:
 (d) stone washing the dyed cotton fibers at a temperature of 10° C. to 80° C. for a period of less than 30 minutes. 
 
     
     
         10 . The method according to  claim 9 , wherein the stone washing is conducted at a temperature of 25° C. to 50° C. for a period of 15 minutes to 30 minutes. 
     
     
         11 . The method according to  claim 1 , wherein the dye material is a disperse or vat dye. 
     
     
         12 . The method according to  claim 1 , wherein the emulsion copolymer employed in (a) is selected from vinyl ester-based, acrylic-based, styrene/acrylic-based and styrene/butadiene-based emulsion copolymers and mixtures thereof. 
     
     
         13 . The method according to  claim 1 , wherein emulsion copolymer employed in (a) is a vinyl ester-based copolymer selected from vinyl acetate-ethylene copolymers, vinyl acetate-vinyl versatate; vinyl acetate-acrylic copolymers, and combinations of said copolymer types. 
     
     
         14 . The method according to  claim 1 , wherein the emulsion copolymer employed in (a) is a vinyl acetate-ethylene copolymer comprising from 60 wt % to 95 wt % of vinyl acetate and from 5 wt % to 40 wt % of ethylene, based on total monomers therein. 
     
     
         15 . The method according to  claim 1 , wherein the emulsion copolymer employed in (a) is an acrylic emulsion copolymer which comprises at least two different types of (meth)acrylate co-monomers. 
     
     
         16 . The method according to  claim 1 , wherein the emulsion copolymer employed in (a) is an acrylic emulsion copolymer comprising ethyl acrylate and butyl acrylate co-monomers. 
     
     
         17 . The method according to  claim 1 , wherein the emulsion copolymer employed in (a) comprises from 0.1 wt % to 10 wt %, based on total monomers in the copolymer, of one or more ethylenically unsaturated cross-linking co-monomers having at least one amide, epoxy, or alkoxysilane group. 
     
     
         18 . The method according to  claim 1 , wherein the emulsion copolymer employed in (a) comprises from 0.1 wt % to 10 wt %, based on total monomers in the copolymer, of one of more multifunctional external cross-linking co-monomers selected from diallyl adipate, triallyl cyanurate, butanediol diacrylate, allyl methacrylate, and combinations of said cross-linking co-monomers.