Waterfast dye fixative compositions for ink jet recording sheets

Abstract

A coating composition comprising a blend of at least two dye fixatives, at least one of which is a cationic polymer, and at least one of the other dye fixatives is a polyvalent metal salt, to form a water-insoluble complex. The ink recording sheets comprise a composition that is absorbed into the surface of the substrate as a sizing material, or alternatively, forms a continuous layer on the substrate. The present invention also encompasses methods for making the ink jet recording sheets.

1 . A coating composition comprising a blend of at least two dye fixatives, wherein at least one of said dye fixatives is a cationic polymer and at least one of said other dye fixatives is a polyvalent metal salt, wherein said blend forms a water-insoluble complex.  
     
     
         2 . The composition according to  claim 1 , wherein the cationic polymer is selected from the group consisting of dicyandiamide-formaldehyde resin, polyethylenimine-epichlorohydrin, polydiallyldimethylammonium chloride, and cationic polymers which contain primary, secondary, tertiary or quaternary amine functionalities.  
     
     
         3 . The composition according to  claim 2 , wherein said cationic polymers containing amine functionalities are selected from the group consisting of cationic starches, cationic polyvinyl alcohols, cationic vinyl polymers, cationic styrene-containing polymers, cationic polyurethanes, and quaternary amine salts.  
     
     
         4 . The composition according to  claim 1 , wherein the polyvalent metal salt is a water-soluble salt containing an element selected from the group consisting of aluminum, magnesium, zinc, manganese, copper, cobalt, tin, nickel, chromium, zirconium, and iron.  
     
     
         5 . The composition according to  claim 4 , wherein the polyvalent metal salt is a polyaluminum chloride.  
     
     
         6 . The composition according to  claim 5 , wherein the polyaluminum chloride is aluminum chlorohydrate.  
     
     
         7 . The composition according to  claim 1 , wherein the cationic polymer is dicyandiamide-formaldehyde resin and the polyvalent metal salt is aluminum chlorohydrate.  
     
     
         8 . The composition according to  claim 7 , wherein the ratio of aluminum chlorohydrate to dicyandiamide-formaldehyde resin is in the range of 1:20 to 1:1.  
     
     
         9 . The composition according to  claim 8 , wherein the ratio of aluminum chlorohydrate to dicyandiamide-formaldehyde resin is 1:2.  
     
     
         10 . An ink jet recording sheet comprising a substrate coated on at least one surface with a composition comprising a blend of at least two dye fixatives; wherein said blend forms a water-insoluble complex.  
     
     
         11 . The ink recording sheet according to  claim 10 , wherein said substrate is selected from the group consisting of paper, textile and plastic film.  
     
     
         12 . The recording sheet according to  claim 10 , wherein said composition forms a continuous film on said substrate surface.  
     
     
         13 . The recording sheet according to  claim 10 , wherein said composition is absorbed into the surface of said substrate as a sizing material.  
     
     
         14 . The recording sheet according to  claim 12 , wherein said continuous film is an ink receiving layer which further comprises a material selected from the group consisting of binders, pigments, defoamers, surfactants, thickeners, and a combination of at least two of the materials.  
     
     
         15 . The recording sheet according to  claim 13 , wherein said composition further comprises a material selected from the group consisting of pore volume regulators, defoamers, surfactants, thickeners, and a combination of at least two of the materials.  
     
     
         16 . The recording sheet according to  claim 14 , wherein said binders are selected from the group consisting of starch, derivatives of starch, cross-linked polyvinyl alcohol, cross-linked derivatives of polyvinyl alcohol, modified polyvinyl alcohol, modified cellulosics, proteins, vinyl polymers, styrene-containing polymers, and polyurethanes.  
     
     
         17 . The recording sheet according to  claim 14 , wherein said pigment is selected from the group consisting of silica, alumina, clay, and calcium carbonate.  
     
     
         18 . A method for making an ink jet recording sheet comprising: 
 providing a composition comprising a blend of at least two dye fixatives;    adjusting the pH of said blend to between 6 and 8 to form a water-insoluble complex;    providing a substrate; and    coating said composition on at least one surface of said substrate.    
     
     
         19 . The method according to  claim 18 , wherein said composition forms a continuous film on said substrate surface.  
     
     
         20 . The method according to  claim 18 , wherein said composition is absorbed into the surface of said substrate as a sizing material.  
     
     
         21 . The method according to  claim 18 , wherein prior to said pH adjustment said composition further comprises a material selected from the group consisting of binders, pore volume regulators, pigments, defoamers, surfactants, thickeners, and a combination of at least two of the materials.  
     
     
         22 . The method of  claim 18  wherein after said pH adjustment and prior to said coating said composition further comprises a material selected from the group consisting of binder, pore volume regulator, pigment, defoamer, surfactant, thickener, and a combination of at least two of the materials.