Modified filler composition, method for making same, pulp and paper using same

Abstract

A modified filler composition used in papermaking is provided. The modified filler composition contains nanofibrillated cellulose having a carboxyl content of about 0.05 to about 1.5 mmol/g, and filler having positive charge.

1 . A modified filler composition, comprising:
 filler having positive charge; and   nanofibrillated cellulose, the nanofibrillated cellulose having a dry weight of about 0.1% to about 20% of that of the filler, the nanofibrillated cellulose having a carboxyl content of about 0.05 to about 1.5 mmol/g.   
     
     
         2 . The modified filler composition as claimed in  claim 1 , wherein the nanofibrillated cellulose has a dry weight of about 0.1% to about 10% of that of the filler. 
     
     
         3 . The modified filler composition as claimed in  claim 1 , wherein nanofibrillated cellulose has a carboxyl content of about 0.1 to about 1.0 mmol/g. 
     
     
         4 . The modified filler composition as claimed in  claim 1 , wherein the filler is selected from precipitated calcium carbonate, ground calcium carbonate, kaolin, and talc. 
     
     
         5 . The modified filler composition as claimed in  claim 1 , wherein the modified filler composition further comprises water. 
     
     
         6 . A method for making a modified filler composition, comprising:
 providing nanofibrillated cellulose having a carboxyl content of about 0.05 to about 1.5 mmol/g;   mixing filler and water together to make a filler slurry, the filler having positive charge;   adding the nanofibrillated cellulose to the filler slurry and stirring, the dry weight of the nanofibrillated cellulose being about 0.1% to about 20% of that of the filler.   
     
     
         7 . The method for making a modified filler composition as claimed in  claim 6 , wherein the nanofibrillated cellulose has a carboxyl content of about 0.1 to about 1.0 mmol/g. 
     
     
         8 . The method for making a modified filler composition as claimed in  claim 6 , wherein the dry weight of the nanofibrillated cellulose is about 0.1% to about 10% of that of the filler. 
     
     
         9 . The method for making a modified filler composition as claimed in  claim 6 , wherein the filler is selected from precipitated calcium carbonate, ground calcium carbonate, kaolin, and talc. 
     
     
         10 . The method for making a modified filler composition as claimed in  claim 6 , wherein the filler slurry has a concentration of about 10% to about 50%. 
     
     
         11 . A paper pulp, comprising:
 pulp fiber;   modified filler composition having a dry weight of 5% to 100% of that of the pulp fiber; and   cationic polyelectrolyte, the cationic polyelectrolyte having a dry weight of 0.01% to 1% of that of the pulp fiber,   wherein the modified filler composition comprises nanofibrillated cellulose having a carboxyl content of about 0.05 to about 1.5 mmol/g; and filler having positive charge, and the dry weight of the nanofibrillated cellulose is about 0.1% to about 20% of that of the filler.   
     
     
         12 . The paper pulp as claimed in  claim 11 , wherein the dry weight of the nanofibrillated cellulose is about 0.1% to about 10% of that of the filler. 
     
     
         13 . The paper pulp as claimed in  claim 11 , wherein the nanofibrillated cellulose has a carboxyl content of about 0.1 to about 1.0 mmol/g. 
     
     
         14 . The paper pulp as claimed in  claim 11 , wherein the filler is selected from precipitated calcium carbonate, ground calcium carbonate, kaolin, and talc. 
     
     
         15 . The paper pulp as claimed in  claim 11 , wherein the cationic polyelectrolyte is cationic starch or cationic polyacrylamide. 
     
     
         16 . A paper, comprising:
 paper fiber;   modified filler composition; and   cationic polyelectrolyte,   wherein the modified filler composition comprises nanofibrillated cellulose having a carboxyl content of about 0.05 to about 1.5 mmol/g; and filler having positive charge, and the dry weight of the nanofibrillated cellulose is about 0.1% to about 20% of that of the filler.   
     
     
         17 . The paper as claimed in  claim 16 , wherein the dry weight of the nanofibrillated cellulose is about 0.1% to about 10% of that of the filler. 
     
     
         18 . The paper as claimed in  claim 16 , wherein the nanofibrillated cellulose has a carboxyl content of about 0.1 to about 1.0 mmol/g. 
     
     
         19 . The paper as claimed in  claim 16 , wherein the cationic polyelectrolyte is cationic starch or cationic polyacrylamide.