Composition for increasing cellulosic product strength and method of increasing cellulosic product strength

Abstract

A composition includes water; at least one hydrophilic polymer containing at least two groups which are independently the same or different a primary amine group or a secondary amine group and at least one saccharide containing a reducible function as described above. The hydrophilic polymer and the saccharide are mixed to form a reaction mixture and reacted to increase the viscosity of the reaction mixture. The reaction is then substantially terminated by reducing the pH of the composition.

1 . A composition comprising: water; at least one hydrophilic polymer containing at least two groups which are independently the same or different a primary amine group or a secondary amine group and at least one saccharide containing a reducible function, the hydrophilic polymer and the saccharide being mixed to form a reaction mixture and reacted until to increase the viscosity of the reaction mixture, the reaction then being substantially terminated by reducing the pH of the composition. 
     
     
         2 . The composition of  claim 1  wherein the predetermined viscosity of the composition is at least 20 cp at 80° C. when the reaction is substantially terminated. 
     
     
         3 . The composition of  claim 1  wherein the predetermined viscosity of the composition is in the range of approximately 20 cp to 100 cp at 80° C. when the reaction is substantially terminated. 
     
     
         4 . The composition of  claim 1  wherein the predetermined viscosity of the composition is in the range of approximately 20 cp to 60 cp at 80° C. when the reaction is substantially terminated. 
     
     
         5 . The composition of  claim 1  wherein the predetermined viscosity of the composition is in the range of approximately 20 cp to 40 cp at 80° C. when the reaction is substantially terminated. 
     
     
         6 . The composition of  claim 2  wherein the predetermined viscosity of the composition at reduced pH is no greater than 80 cp at 23° C. 
     
     
         7 . The composition of  claim 1  wherein the pH of the composition is greater than 7 during reaction and reduced to less than 7 to substantially terminate the reaction. 
     
     
         8 . The composition of  claim 1  wherein the pH of the composition is greater in the range of approximately 10 to 12 during reaction and reduced to 6 or less to substantially terminate the reaction. 
     
     
         9 . The composition of  claim 8  wherein the pH of the composition is reduced to a pH in the range of approximately 4 to 6 to substantially terminate the reaction. 
     
     
         10 . The composition of  claim 8  wherein the pH of the composition is reduced to a pH in the range of approximately 5 to 6 to substantially terminate the reaction. 
     
     
         11 . The composition of  claim 1  wherein the reducing saccharide is a monosaccharide, a disaccharide or a polysaccharide. 
     
     
         12 . The composition of  claim 1  wherein the polymer is partially hydrolyzed poly(N-vinylformamide), partially hydrolyzed vinyl acetate/N-vinylformamide copolymer, hydrolyzed acrylonitrile/N-vinylformamide copolymer, amine functional polyacrylamide, acrylic acid/vinylamine copolymer, maleic anhydride/maleic acid copolymers with N-vinylformamide/vinylamine, N-vinylformamide/vinylamine polymers with vinyl sulfonate comonomer units, NVF/vinylamine copolymers with at least one cationic monomer, allylamine polymer, diallylamine polymer, allylamine/diallylamine copolymer, urea/formaldehyde condensation polymers, melamine/formaldehyde condensation polymers, amidoamine polymers, amine/epichlorohydrin polymers, poly(ethyleneimine), hydrolyzed poly(2-alkyl-2-oxazoline) or partially hydrolyzed poly(2-alkyl-2-oxazoline). 
     
     
         13 . The composition of  claim 1  wherein the polymer is a copolymer of vinyl amine and vinyl alcohol. 
     
     
         14 . The composition of  claim 1  wherein the saccharide is at least one of glucose, lactose, or 2-deoxy-D-ribose 
     
     
         15 . The composition of  claim 1  wherein the water, the hydrophilic polymer and the reducing saccharide are contacted at approximately a temperature of approximately 25° C. or below and subsequently heated to induce a crosslinking reaction of the hydrophilic polymer and the reducing saccharide. 
     
     
         16 . The composition of  claim 15  wherein the pH of the composition is at least 10 during the reaction. 
     
     
         17 . The composition of  claim 12  wherein the polymer is an NVF/vinylamine copolymer with diallyldimethylammonium chloride or with a cationic acrylate comonomer.