Granular polysaccharide having enhanced surface charge

Abstract

A modified polysaccharide having enhanced surface charge. The polysaccharide is modified to include a cationic polymer, preferably a polyquaternary amine, and has a surface charge from about +5 to about +20 mV. The modified polysaccharide can be advantageous incorporated into a papermaking furnish with enhanced retention.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:  
     
         1 . A composition comprising a polysaccharide particle and a cationic additive, wherein the cationic additive is adhered to the polysaccharide particle to provide a polysaccharide particle having a positive surface charge.  
     
     
         2 . The composition of  claim 1  wherein the cationic additive comprises a cationic polymer.  
     
     
         3 . The composition of  claim 2  wherein the cationic polymer comprises a polyquaternary amine.  
     
     
         4 . The composition of  claim 3  wherein the polyquaternary amine has a molecular weight in the range from about 1 million to about 5 million grams per mole.  
     
     
         5 . The composition of  claim 3  wherein the polyquaternary amine has about 3 meq quaternary amine per gram.  
     
     
         6 . The composition of  claim 1  wherein the cationic additive is present in the composition in an amount from about 1 to about 15 pounds per ton polysaccharide.  
     
     
         7 . The composition of  claim 1  wherein the surface charge is in the range from about +1 mV to about +100 mV.  
     
     
         8 . The composition of  claim 1  wherein the polysaccharide is selected from the group consisting of corn, potato, tapioca, pea, and wheat starches.  
     
     
         9 . A pulp furnish comprising a polysaccharide particle having a positive surface charge, wherein the polysaccharide particle having a positive surface charge comprises a cationic additive adhered to the polysaccharide particle.  
     
     
         10 . The furnish of  claim 9  wherein the cationic additive comprises a cationic polymer.  
     
     
         11 . The furnish of  claim 10  wherein the cationic polymer comprises a polyquaternary amine.  
     
     
         12 . The furnish of  claim 9  wherein the polysaccharide particle has a surface charge in the range from about +1 mV to about +100 mV.  
     
     
         13 . The furnish of  claim 9  further comprising an anionic retention aid.  
     
     
         14 . The furnish of  claim 9  further comprising a cationic retention aid.  
     
     
         15 . The furnish of  claim 13  further comprising a cationic retention aid.  
     
     
         16 . The furnish of  claim 13  wherein the anionic retention aid comprises an anionic polyacrylamide.  
     
     
         17 . The furnish of  claim 16  wherein the anionic polyacrylamide comprises a copolymer of acrylic acid and acrylamide.  
     
     
         18 . The furnish of  claim 17  wherein the copolymer comprises about 30 mole percent acrylic acid and about 70 mole percent acrylamide.  
     
     
         19 . The furnish of  claim 17  wherein the copolymer has a molecular weight in the range from about 8 to about 15 million grams per mole.  
     
     
         20 . The furnish of  claim 13  wherein the anionic retention aid is present in the furnish in an amount from about 0.1 to about 3.0 pounds per ton fiber.  
     
     
         21 . The furnish of  claim 14  wherein the cationic retention aid comprises a cationic polyacrylamide.  
     
     
         22 . The furnish of  claim 21  wherein the cationic polyacrylamide comprises a copolymer of acrylamide and a quaternary amine monomer.  
     
     
         23 . The furnish of  claim 22  wherein the copolymer comprises about 90 mole percent acrylamide and about 10 mole percent quaternary amine monomer.  
     
     
         24 . The furnish of  claim 22  wherein the copolymer has a molecular weight in the range from about 8 to about 15 million grams per mole.  
     
     
         25 . The furnish of  claim 14  wherein the cationic retention aid is present in the furnish in an amount from about 0.1 to about 12 pounds per ton fiber.  
     
     
         26 . A paper product comprising a polysaccharide particle having a positive surface charge, wherein the polysaccharide particle having a positive surface charge comprises a cationic additive adhered to the polysaccharide particle.  
     
     
         27 . The paper product of  claim 26  wherein the cationic additive comprises a cationic polymer.  
     
     
         28 . The paper product of  claim 27  wherein the cationic polymer comprises a polyquaternary amine.  
     
     
         29 . The paper product of  claim 26  wherein the polysaccharide particle has a surface charge in the range from about +1 mV to about +100 mV.  
     
     
         30 . The paper product of  claim 26  further comprising an anionic retention aid.  
     
     
         31 . The paper product of  claim 26  further comprising a cationic retention aid.  
     
     
         32 . The paper product of  claim 30  further comprising a cationic retention aid.  
     
     
         33 . The paper product of  claim 30  where in the anionic retention aid comprises an anionic polyacrylamide.  
     
     
         34 . The paper product of  claim 31  wherein the cationic retention aid comprises a cationic polyacrylamide.  
     
     
         35 . The paper product of  claim 26  wherein the paper product is selected from the group consisting of fine paper, newsprint, bleached board, liner board, medium board, and old corrugated cardboard.  
     
     
         36 . A method for forming a paper product comprising: 
 adding a polysaccharide particle having a positive surface charge to a first pulp furnish to provide a second pulp furnish, wherein the polysaccharide particle having a positive surface charge comprises a cationic additive adhered to the polysaccharide particle;    depositing the second pulp furnish onto a forarinous support to provide a wet web; and    dewatering and drying the wet web to provide the paper product.    
     
     
         37 . The method of  claim 36  wherein the cationic additive comprises a cationic polymer.  
     
     
         38 . The method of  claim 37  wherein the cationic polymer comprises a polyquaternary amine.  
     
     
         39 . The method of  claim 36  wherein the starch particle has a surface charge in the range from about +1 mV to about +100 mV.  
     
     
         40 . The method of  claim 36  further comprising adding an anionic retention aid to the first pulp furnish.  
     
     
         41 . The method of  claim 36  further comprising adding a cationic retention aid to the first pulp furnish.  
     
     
         42 . The method of  claim 40  further comprising adding a cationic retention aid to the first pulp furnish.  
     
     
         43 . The method of  claim 40  wherein the anionic retention aid comprises an anionic polyacrylamide.  
     
     
         44 . The method of  claim 41  wherein the cationic retention aid comprises a cationic polyacrylamide.  
     
     
         45 . The method of  claim 36  wherein the paper product is selected from the group consisting of fine paper, newsprint, bleached board, liner board, medium board, and old corrugated cardboard.  
     
     
         46 . A method for increasing the strength of a paper product comprising: 
 adding a polysaccharide particle having a positive surface charge to a first pulp furnish to provide a second pulp furnish, wherein the polysaccharide particle having a positive surface charge comprises a cationic additive adhered to the polysaccharide particle;    depositing the second pulp furnish onto a foraminous support to provide a wet web; and    dewatering and drying the wet web to provide the paper product having increased strength compared to a similarly constituted paper lacking a polysaccharide particle having a positive surface charge.    
     
     
         47 . The method of  claim 46  wherein the cationic additive comprises a cationic polymer.  
     
     
         48 . The method of  claim 47  wherein the cationic polymer comprises a polyquaternary amine.  
     
     
         49 . The method of  claim 47  wherein the polysaccharide particle has a surface charge in the range from about +1 mV to about +100 mV.  
     
     
         50 . The method of  claim 47  further comprising adding an anionic retention aid to the first pulp furnish.  
     
     
         51 . The method of  claim 47  further comprising adding a cationic retention aid to the first pulp furnish.  
     
     
         52 . The method of  claim 50  further comprising adding a cationic retention aid to the first pulp furnish.  
     
     
         53 . The method of  claim 50  wherein the anionic retention aid comprises an anionic polyacrylamide.  
     
     
         54 . The method of  claim 52  wherein the cationic retention aid comprises a cationic polyacrylamide.  
     
     
         55 . The method of  claim 46  wherein the paper product is selected from the group consisting of fine paper, newsprint, bleached board, liner board, medium board, and old corrugated cardboard.