Pigments for colored paper

Abstract

Compositions and methods of producing colored paper products and agents for making such products are disclosed. Surface-modified pigments can be manufactured to provide selected coloring in a paper product. The pigment can include filler particles that are bound to one or more dye components with a coupling agent, such as a silane coupling agent or a polymer such as a polycation. The pigment can also be formulated to produce a paper product with better particulate and/or fines retention, and/or higher strength by including components that can interact favorably with the fibers of a paper material. The surface-modified pigments can also be utilized to make coloring formulations such as inks for printers and other applications.

1 . A colored paper product, comprising:
 pulp comprising a plurality of fibers; and   surface-modified pigment particles imparting color to the paper product, the surface-modified pigment particles comprising:   (i) a filler particle embedded within the pulp,   (ii) at least one dye component adapted to provide a selected color to the paper product, and   (iii) a coupling agent binding the at least one dye component and the filler particle together.   
     
     
         2 . The colored paper product of  claim 1 , wherein the coupling agent is directly bound to the filler particle by at least one of covalent bonding, non-covalent bonding, electrostatic forces, Van der Waals forces, hydrogen bonding, and intermolecular forces. 
     
     
         3 . The colored paper product of  claim 1 , wherein the pulp comprises cellulosic-based fibers. 
     
     
         4 . The colored paper product of  claim 1 , wherein the filler particle of the surface-modified pigment particles comprises at least one of a biopolymer, a bio-oligomer, metal oxide, silaceous material, and calcium carbonate. 
     
     
         5 . The colored paper product of  claim 1 , wherein the filler particle of the surface-modified pigment particles comprises an inorganic surface. 
     
     
         6 . The colored paper product of  claim 5 , wherein the inorganic surface comprises at least one of calcium carbonate, kaolin, and titanium dioxide. 
     
     
         7 . The colored paper product of  claim 5 , wherein the inorganic surface of the surface-modified pigment particles comprises sites attached to the coupling agent by reaction of a hydroxide group of the inorganic surface. 
     
     
         8 . The colored paper product of  claim 1 , wherein the coupling agent comprises a silane group reacted to attach the coupling agent and the filler particle together. 
     
     
         9 . The colored paper product of  claim 8 , wherein the coupling agent further comprises a reactive group including at least one of an acrylate, an amine, an amino, a carboxyl, a thiol, an epoxy, an isocyano group, and a hydroxyl, the reactive group reacted to bind the reactive group and the filler particle together. 
     
     
         10 . The colored paper product of  claim 1 , wherein the coupling agent comprises a polyelectrolyte. 
     
     
         11 . The colored paper product of  claim 10 , wherein the polyelectrolyte comprises a polycationic polymer. 
     
     
         12 . The colored paper product of  claim 11 , wherein the polycationic polymer comprises at least one of an amine-containing polymer and a cationic starch. 
     
     
         13 . The colored paper product of  claim 12 , wherein the amine-containing polymer comprises at least one of chitosan, polyalkyleneimine, polyvinyl amine, and polyallyl amine. 
     
     
         14 . The colored paper product of  claim 11 , further comprising:
 an anionic component adapted to couple the anionic component and the polycationic polymer together.   
     
     
         15 . The colored paper product of  claim 14 , wherein the anionic component is adapted to bind the at least one dye component and the polycationic polymer together. 
     
     
         16 . The colored paper product of  claim 15 , wherein the anionic component is a polyanion. 
     
     
         17 . The colored paper product of  claim 15 , wherein the anionic component comprises another coupling agent including a silane group. 
     
     
         18 . The colored paper product of  claim 1 , wherein the at least one dye component comprises at least one of halogenotrizine, carboxypyridinium-substituted triazine, trihalogenopyrimidine, dichloroquinoxaline, vinyl sulfone, halotriazine, anthraquinone-like structure, azo dye, triaryl dye, and metal complex. 
     
     
         19 . The colored paper product of  claim 1 , wherein the at least one dye component comprises at least one of a fluorescent dye, a phosphorescent dye, a photochromic dye, a thermochromic dye, a FD&C dye, a whitener, a brightener, a light stabilizer, and an ultraviolet light stabilizer. 
     
     
         20 . The colored paper product of  claim 1 , wherein the surface-modified pigment particles are adapted so that at least one surface-modified pigment particle and at least one fiber of the pulp are bound together. 
     
     
         21 . The colored paper product of  claim 20 , wherein the surface-modified pigment particles include coupling agent binding the filler particle and at least one fiber of the pulp together. 
     
     
         22 . The colored paper product of  claim 20 , wherein the surface-modified pigment particles further comprise a functionalizing polymer binding the filler particle and at least one fiber of the pulp together. 
     
     
         23 . The colored paper product of  claim 22 , wherein the functionalizing polymer and the coupling agent are attached together. 
     
     
         24 . The colored paper product of  claim 23 , wherein the functionalizing polymer and the coupling agent are directly attached together. 
     
     
         25 . The colored paper product of  claim 22 , wherein the functionalizing polymer and the filler particle are bound together by at least one of covalent bonding, non-covalent bonding, electrostatic forces, Van der Waals forces, hydrogen bonding, and intermolecular forces. 
     
     
         26 . The colored paper product of  claim 22 , wherein the functionalizing polymer comprises at least one of an amine-containing polymer, a glycoaminoglycan, an amino-containing polymer, and an imine-containing polymer. 
     
     
         27 . The colored paper product of  claim 1 , wherein the surface-modified pigment particles further comprise an intermediary component binding the coupling agent and filler particle together. 
     
     
         28 . The colored paper product of  claim 1 , wherein the surface-modified pigment particles further comprise an intermediary component binding the coupling agent and the at least one dye component together. 
     
     
         29 - 54 . (canceled) 
     
     
         55 . A method of producing a colored paper product, comprising:
 producing a surface-modified pigment by binding filler particles and at least one dye component together using a coupling agent;   mixing the surface-modified pigment with pulp comprising a plurality of fibers to produce a papermaking dispersion; and   forming the colored paper product using the papermaking dispersion.   
     
     
         56 . The method of  claim 55 , further comprising:
 binding the filler particles and at least one fiber of the pulp together.   
     
     
         57 . The method of  claim 55 , wherein the step of producing the surface-modified pigment begins before the step of mixing the surface-modified pigment with pulp. 
     
     
         58 . The method of  claim 55 , wherein the steps of producing the surface-modified pigment and mixing the surface-modified pigment with pulp occur substantially simultaneously. 
     
     
         59 . The method of  claim 55 , wherein the step of producing the surface-modified pigment comprises adjusting color of the paper product by selecting the amount of coupling agent relative to the at least one dye component. 
     
     
         60 . The method of  claim 55 , wherein the step of producing the surface-modified pigment comprises encapsulating the filler particles with a polycation. 
     
     
         61 . The method of  claim 60 , wherein the step of encapsulating the filler particles comprises attaching the polycation and the filler particles together with the coupling agent. 
     
     
         62 . The method of  claim 60 , wherein the polycation is the coupling agent. 
     
     
         63 . The method of  claim 62 , further comprising:
 coupling the at least one dye component and the polycation together before encapsulating the filler particles with the polycation.   
     
     
         64 . The method of  claim 60 , wherein the step of encapsulating the filler particles comprises self assembling the polycation on a surface of the filler particles. 
     
     
         65 . The method of  claim 60 , further comprising:
 binding an anionic component to the polycation.   
     
     
         66 . The method of  claim 55 , wherein the coupling agent comprises a silane group. 
     
     
         67 - 76 . (canceled)