Thickeners for paper dye compositions

Abstract

The present invention is a thickened dye composition and method of applying same to a paper web that produces colored or patterned paper having good bleed resistance. The dye composition of the invention includes a binder; a dye; a thickener selected from the group consisting of polyvinylpyrrolidone homopolymers, polyvinylpyrrolidone copolymers, and mixtures thereof; and water. The present invention also includes colored or patterned papers prepared using this dye composition.

That which is claimed:  
     
         1 . A dye composition for dyeing a paper web, comprising: 
 a binder;    a dye;    a thickener selected from the group consisting of polyvinylpyrrolidone homopolymers, polyvinylpyrrolidone copolymers, and mixtures thereof; and    water.    
     
     
         2 . The dye composition according to  claim 1 , wherein the thickener is a polyvinylpyrrolidone homopolymer.  
     
     
         3 . The dye composition according to  claim 1 , wherein the thickener is a poly(vinylpyrrolidone-vinyl acetate) copolymer.  
     
     
         4 . The dye composition according to  claim 1 , further comprising at least one additional thickener formed of an acrylic acid/alkyl acrylate copolymer.  
     
     
         5 . The dye composition according to  claim 1 , further comprising at least one additional thickener selected from the group consisting of guar gum, jaguar, carrageenan, xanthan, acetan, konjac mannan, xyloglucan, CMC, HEMC, urethanes and mixtures thereof.  
     
     
         6 . The dye composition according to  claim 1 , wherein the binder is selected from the group consisting of starches, acrylic ester/styrene copolymers, acrylic ester/acrylonitrile copolymers, carboxylated styrene/butadiene copolymers, polyvinyl alcohol, polyvinyl acetate, casein, soybean protein, carboxymethylcellulose (CMC), hydroxyethylmethyl cellulose (HEMC), polyesters, polyethers, alkyd resins, and mixtures thereof.  
     
     
         7 . The dye composition according to  claim 1 , wherein the binder includes at least one of a starch and an acrylic ester/styrene copolymer.  
     
     
         8 . The dye composition according to  claim 1 , further comprising a crosslinker.  
     
     
         9 . The dye composition according to  claim 8 , wherein the crosslinker is selected from the group consisting of blocked and straight or unblocked glyoxal-based insolubilizers, aliphatic epoxy resins, ammonium zirconium carbonate, potassium zirconium carbonate, melamine, melamine formaldehyde, blocked isocyanates, and mixtures thereof.  
     
     
         10 . The dye composition according to  claim 8 , wherein the crosslinker is a blocked glyoxal-based insolubilizer.  
     
     
         11 . The dye composition according to  claim 1 , wherein the dye is selected from the group consisting of basic dyes, acid dyes, anionic direct dyes, cationic direct dyes, anionic pigment dispersions, and cationic pigment dispersions.  
     
     
         12 . The dye composition according to  claim 11 , wherein the dye is an anionic direct dye or a cationic direct dye.  
     
     
         13 . The dye composition according to  claim 1 , further comprising a filler.  
     
     
         14 . The dye composition according to  claim 13 , wherein the filler is selected from the group consisting of silica, silica gel, calcium carbonate, calcium sulfite, pyrophilite, kaolin, clay, titanium oxide, aluminum hydroxide, aluminum trihydrate, satine white, barium sulfate, magnesium oxide, talc, colloidal silica, plastic pigments, and white urea resin pigments.  
     
     
         15 . The dye composition according to  claim 13 , wherein the filler is silica.  
     
     
         16 . A method of dyeing a paper web, comprising the step of: 
 applying a dye composition to a paper web, the dye composition comprising a binder; a dye; a thickener selected from the group consisting of polyvinylpyrrolidone homopolymers, polyvinylpyrrolidone copolymers, and mixtures thereof; and water.    
     
     
         17 . The method according to  claim 16 , wherein the applying step comprises applying a dye composition wherein the thickener is a polyvinylpyrrolidone homopolymer.  
     
     
         18 . The method according to  claim 16 , wherein the applying step comprises applying a dye composition wherein the thickener is a poly(vinylpyrrolidone-vinyl acetate) copolymer.  
     
     
         19 . The method according to  claim 16 , wherein the applying step comprises applying a dye composition having an additional thickener formed of an acrylic acid/alkyl acrylate copolymer.  
     
     
         20 . The method according to  claim 16 , wherein the applying step comprises applying a dye composition wherein the binder is selected from the group consisting of starches, acrylic ester/styrene copolymers, acrylic ester/acrylonitrile copolymers, carboxylated styrene/butadiene copolymers, and mixtures thereof.  
     
     
         21 . The method according to  claim 16 , wherein the applying step comprises applying a dye composition further comprising a crosslinker.  
     
     
         22 . The method according to  claim 21 , wherein the applying step comprises applying a dye composition wherein the crosslinker is selected from the group consisting of blocked and straight or unblocked glyoxal-based insolubilizers, aliphatic epoxy resins, ammonium zirconium carbonate, potassium zirconium carbonate, melamine, melamine formaldehyde, blocked isocyanates, and mixtures thereof.  
     
     
         23 . The method according to  claim 21 , wherein the applying step comprises applying a dye composition wherein the crosslinker is a blocked glyoxal-based insolubilizer.  
     
     
         24 . The method according to  claim 16 , wherein the applying step comprises applying a dye composition wherein the dye is selected from the group consisting of basic dyes, acid dyes, anionic direct dyes, cationic direct dyes, anionic pigment dispersions, and cationic pigment dispersions.  
     
     
         25 . The method according to  claim 16 , wherein the applying step comprises applying a dye composition further comprising a filler.  
     
     
         26 . The method according to  claim 25 , wherein the applying step comprises applying a dye composition wherein the filler is selected from the group consisting of silica, silica gel, calcium carbonate, calcium sulfite, pyrophilite, kaolin, clay, titanium oxide, aluminum hydroxide, aluminum trihydrate, satine white, barium sulfate, magnesium oxide, talc, colloidal silica, plastic pigments, and white urea resin pigments.  
     
     
         27 . The method according to  claim 16 , wherein said applying step comprises applying the dye composition to the paper web in a sizing press.  
     
     
         28 . The method according to  claim 16 , wherein said applying step comprises spraying the dye composition onto the paper or paper web.  
     
     
         29 . The method according to  claim 16 , further comprising the step of coating a paper web with a dye fixing agent and drying the paper web prior to said treating step.  
     
     
         30 . The method according to  claim 29 , wherein said coating step comprises coating a paper web with a dye fixing agent selected from the group consisting of polyethyleneimines, polyethyleneimine derivatives, sodium chloride, magnesium chloride, potassium chloride, alum, diallyl dimethyl ammonium chloride (DADMAC) and polymers thereof, optical brightening agents (OBA's), silicas, and mixtures thereof  
     
     
         31 . The method according to  claim 29 , wherein said coating step comprises coating a paper web with a polyethyleneimine or polyethyleneimine derivative solution.  
     
     
         32 . The method according to  claim 16 , further comprising the step of preparing the dye composition by mixing a binder solution or dispersion; a dye powder, solution or dispersion; a thickener powder, solution or dispersion; and water.  
     
     
         33 . The method according to  claim 16 , wherein said applying step comprises applying the dye composition to a paper web and drying the paper web after said applying step.  
     
     
         34 . In a method for dyeing a paper web using a dye composition comprising a binder, a dye, and water, the improvement comprising adding a thickener selected from the group consisting of polyvinylpyrrolidone homopolymers, polyvinylpyrrolidone copolymers, and mixtures thereof, to the dye composition.  
     
     
         35 . The method according to  claim 34 , wherein the thickener is a polyvinylpyrrolidone homopolymer.  
     
     
         36 . The method according to  claim 34 , wherein the thickener is a poly(vinylpyrrolidone-vinyl acetate) copolymer.  
     
     
         37 . The method according to  claim 34 , wherein the improvement further comprises adding an additional thickener formed of an acrylic acid/alkyl acrylate copolymer.  
     
     
         38 . A colored or patterned paper, comprising a sheet of cellulose fibers, the sheet having coated thereon a dye composition comprising a binder, a dye, and a thickener selected from the group consisting of polyvinylpyrrolidone homopolymers, polyvinylpyrrolidone copolymers, and mixtures thereof.  
     
     
         39 . The colored or patterned paper according to  claim 38 , wherein the sheet further has coated thereon a dye fixing agent.  
     
     
         40 . The colored or patterned paper according to  claim 39 , wherein the dye fixing agent is polyethyleneimine or a polyethyleneimine derivative.  
     
     
         41 . A colored or patterned paper prepared by a process, comprising the steps of: 
 coating a paper web with a polyethyleneimine solution;    drying the paper web; and    applying a dye composition to the coated paper web, the dye composition comprising a binder; a dye; a thickener selected from the group consisting of polyvinylpyrrolidone homopolymers, polyvinylpyrrolidone copolymers, and mixtures thereof; and water.