Modified filler composition and papermaking process using the same

Abstract

A modified filler composition used in papermaking is provided. The modified filler composition contains microfibrillated cellulose, filler, and latex having a glass transition temperature of less than 20° C. The dry weight of the microfibrillated cellulose is about 0.1% to about 10% that of the filler; the dry weight of the latex is about 0.1% to about 15% that of the filler.

1 . A modified filler composition, comprising:
 microfibrillated cellulose,   filler, and   latex having a glass transition temperature of less than 20° C.,   wherein the dry weight of the microfibrillated cellulose is about 0.1% to about 10% of that of the filler, the dry weight of the latex is about 0.1% to about 15% of that of the filler.   
     
     
         2 . The modified filler composition as claimed in  claim 1 , wherein the microfibrillated cellulose has negative charge and comprises carboxyl groups, the content of carboxyl groups of the microfibrillated cellulose is in the range from about 0.06 to about 1.7 mmol/g. 
     
     
         3 . The modified filler composition as claimed in  claim 2 , wherein the microfibrillated cellulose comprises water-soluble cellulose having a mass percentage of about 0.1% to about 50% and water-insoluble cellulose having a mass percentage of about 10% to about 99.9%. 
     
     
         4 . The modified filler composition as claimed in  claim 3 , wherein the water-soluble celluloses comprises nanocrystalline cellulose, nanofibrillated cellulose, and oligosaccharide. 
     
     
         5 . The modified filler composition as claimed in  claim 1 , wherein the latex has a glass transition temperature of less than 10° C. 
     
     
         6 . The modified filler composition as claimed in  claim 1 , wherein the latex is selected from the group consisting of polybutadiene latex, styrene-butadiene latex, carboxylic butadiene-styrene latex, cationic butadiene-styrene latex, polyvinyl acetate latex, and any combination thereof. 
     
     
         7 . The modified filler composition as claimed in  claim 1 , wherein the filler adsorbing on the surface of the microfibrillated cellulose has a size uniformity of less than 10. 
     
     
         8 . The modified filler composition as claimed in  claim 1 , wherein more than 50% of the filler has a particle diameter of less than or equal to 2 μm. 
     
     
         9 . The modified filler composition as claimed in  claim 1 , wherein the modified filler composition further comprises a cross-linking agent. 
     
     
         10 . The modified filler composition as claimed in  claim 9 , wherein the cross-linking agent is borate, borax, glutaric dialdehyde, or oxaldehyde; the dry weight of the cross-linking agent is about 0.1% to about 15% of that of the latex. 
     
     
         11 . A papermaking process, comprising:
 providing a modified filler composition, the modified filler composition comprising microfibrillated cellulose, filler, and latex having a glass transition temperature of less than 20° C., the dry weight of the microfibrillated cellulose being about 0.1% to about 10% of that of the filler, the dry weight of the latex being about 0.1% to about 15% of that of the filler.   providing a paper pulp;   adding the modified filler composition into the paper pulp;   employing the paper pulp to make paper.   
     
     
         12 . The papermaking process as claimed in  claim 11 , wherein the modified filler composition is prepared by mixing the microfibrillated cellulose, filler, and latex together. 
     
     
         13 . The papermaking process as claimed in  claim 11 , wherein the process further comprises a step of adding unmodified filler to the paper pulp prior to employing the paper pulp to make paper. 
     
     
         14 . The papermaking process as claimed in  claim 13 , wherein the total weight of the filler in the modified filler composition and the unmodified filler in paper pulp is about 10% to about 300% of the dry weight of the pulp fiber, the weight of filler in the modified filler composition is about 80% to about 100% of the total weight of the filler in the modified filler composition and the unmodified filler. 
     
     
         15 . The papermaking process as claimed in  claim 11 , wherein the microfibrillated cellulose has negative charge and comprises carboxyl groups, the content of carboxyl groups of the microfibrillated cellulose is in the range from about 0.06 to about 1.7 mmol/g. 
     
     
         16 . The papermaking process as claimed in  claim 11 , wherein the microfibrillated cellulose comprises water-soluble cellulose having a mass percentage of about 0.1% to about 50% and water-insoluble cellulose having a mass percentage of about 10% to about 99.9%, the water-soluble celluloses comprises nanocrystalline cellulose, nanofibrillated cellulose, and oligosaccharide. 
     
     
         17 . The papermaking process as claimed in  claim 11 , wherein the latex has a glass transition temperature of less than 10° C. 
     
     
         18 . The papermaking process as claimed in  claim 11 , wherein the latex is selected from the group consisting of polybutadiene latex, styrene-butadiene latex, carboxylic butadiene-styrene latex, cationic butadiene-styrene latex, polyvinyl acetate latex, and any combination thereof. 
     
     
         19 . The papermaking process as claimed in  claim 11 , wherein the filler adsorbed on the surface of the microfibrillated cellulose has a size uniformity of less than 10. 
     
     
         20 . The papermaking process as claimed in  claim 11 , wherein more than 50% of the filler has a particle diameter of less than or equal to 2 μm. 
     
     
         21 . The papermaking process as claimed in  claim 11 , wherein the modified filler composition further comprises a cross-linking agent, the cross-linking agent is borate, borax, glutaric dialdehyde, or oxaldehyde; the weight of the cross-linking agent is 0.1% to 15% of that of the latex. 
     
     
         22 . The papermaking process as claimed in  claim 11 , wherein the process further comprises a step of adding auxiliary additive to the paper pulp prior to employing the paper pulp to make paper.