Retention and drainage in the manufacture of paper

Abstract

A method of improving retention and drainage in a papermaking process is disclosed. The method provides for the addition of a water soluble copolymer prepared under certain conditions, and a siliceous material to the papermaking slurry. Additionally, a composition comprising a water soluble copolymer, prepared under certain conditions, and a siliceous material and optionally further comprising cellulose fiber is disclosed.

1 . A method of improving retention and drainage in a papermaking process wherein the improvement comprising adding to the papermaking slurry a water soluble copolymer and a siliceous material, wherein the water soluble copolymer comprising the formula: 
         B-co-F   (I) 
     wherein B is a nonionic polymer segment formed from the polymerization of one or more ethylenically unsaturated nonionic monomers; F is an anionic, cationic or a combination of anionic and cationic polymer segment(s) formed from polymerization of one or more ethylenically unsaturated anionic or cationic monomers; and the water-soluble copolymer is prepared via a water-in-oil emulsion polymerization technique that employs at least one emulsification surfactant comprising at least one diblock or triblock polymeric surfactant wherein the amount of the at least one diblock or triblock surfactant to monomer is at least about 3:100 and wherein the water-in-oil emulsion polymerization technique comprises the steps: 
 (a) preparing an aqueous solution of monomers,  
 (b) adding the aqueous solution to a hydrocarbon liquid containing surfactant or surfactant mixture to form an inverse emulsion,  
 (c) causing the monomer in the emulsion to polymerize by free radical polymerization at a pH range of from about 2 to less than 7.  
 
   
   
       2 . The method of  claim 1  wherein the siliceous material is selected from the group consisting of silica based particles, colloidal silica, silica sols, silica gels, polysilicates, cationic silica, aluminosilicates, polyaluminosilicates, borosilicates, polyborosilicates, zeolites and combinations thereof.  
   
   
       3 . The method of  claim 1  wherein the siliceous material is a swellable clay.  
   
   
       4 . The method of  claim 3  wherein the swellable clay is a bentonite type clay.  
   
   
       5 . The method of  claim 3  wherein the swellable clay is a smectite.  
   
   
       6 . The method of  claim 3  wherein the swellable clay is selected from the group consisting of hectorite, montmorillonites, nontronites, saponite, sauconite, hormites, attapulgites and sepiolites and combinations thereof.  
   
   
       7 . The method of  claim 1  wherein the siliceous material and water soluble copolymer are added to the cellulosic suspension as a blend or simultaneously.  
   
   
       8 . The method of  claim 1  wherein the siliceous material is added to the cellulosic suspension prior to the addition of the water soluble copolymer.  
   
   
       9 . The method of  claim 1  wherein the water soluble copolymer is anionic.  
   
   
       10 . The method of  claim 1  wherein non-ionic monomer comprises acrylamide and the anionic monomer comprises a salt of acrylic acid.  
   
   
       11 . The method of  claim 1  wherein the water soluble copolymer is cationic.  
   
   
       12 . The method of  claim 1  wherein the water soluble copolymer comprises both anionic and cationic monomers.  
   
   
       13 . The method of  claim 1  wherein the system comprises an additional component wherein the additional component comprises a conventional flocculant.  
   
   
       14 . The method of  claim 1  wherein the system comprises an additional component wherein the additional component comprises an aluminum source.  
   
   
       15 . The method of  claim 1  wherein the amount of water soluble copolymer is from about 0.01 lb/ton to about lb/ton based on the dry weight of pulp.  
   
   
       16 . The method of  claim 1  wherein the amount of siliceous material is from about 0.01 to about 100 lb/ton based on the dry weight of pulp.  
   
   
       17 . A composition comprising a water soluble copolymer and a siliceous material wherein the water soluble copolymer comprising the formula: 
         B-co-F   (I) 
     wherein B is a nonionic polymer segment formed from the polymerization of one or more ethylenically unsaturated nonionic monomers; F is an anionic, cationic or a combination of anionic and cationic polymer segment(s) formed from polymerization of one or more ethylenically unsaturated anionic or cationic monomers; and the water-soluble copolymer is prepared via a water-in-oil emulsion polymerization technique that employs at least one emulsification surfactant comprising at least one diblock or triblock polymeric surfactant wherein the amount of the at least one diblock or triblock surfactant to monomer is at least about 3:100 and wherein the water-in-oil emulsion polymerization technique comprises the steps: 
 (a) preparing an aqueous solution of monomers,  
 (b) adding the aqueous solution to a hydrocarbon liquid containing surfactant or surfactant mixture to form an inverse emulsion,  
 (c) causing the monomer in the emulsion to polymerize by free radical polymerization at a pH range of from about 2 to less than 7.  
 
   
   
       18 . The composition of  claim 17  further comprising cellulosic fiber.  
   
   
       19 . The composition of  claim 17  wherein the water soluble copolymer is anionic.  
   
   
       20 . The composition of  claim 17  wherein the water soluble copolymer is cationic or amphoteric.