Ex parte DICKERSON et al. - Page 2




          Appeal No. 1997-3118                                                        
          Application No. 08/372,083                                                  





               1.  A process for preparing an aqueous papermaking                     
          suspension containing pulp fibers and a polyelectrolyte                     
          complex, comprising:                                                        
               a)   providing an aqueous suspension comprised of pulp                 
          fibers and surface active carboxyl compounds;                               
               b)   adding to the aqueous suspension a water-soluble                  
          cationic polymer and a water-soluble anionic polymer that are               
          reactable in the aqueous suspension to form the                             
          polyelectrolyte complex, and a compound containing a                        
          multivalent cation having at least a +3 charge; and                         
               c) forming the polyelectrolyte complex;                                
               wherein said compound containing a multivalent cation is               
          added at a level such as to provide an amount of cation                     
          equivalent on a molar basis to the amount of aluminum present               
          in alum added at a level of from about 1.5% to about 6% based               
          on the dry weight of pulp fibers.                                           
                                   THE REFERENCES                                     
          Economou                    3,660,338               May   2,                
          1972                                                                        
          Strazdins                   4,002,588               Jan. 11,                
          1977                                                                        
          Smith                       0 362 770               Apr. 11,                
          1990                                                                        
               (European patent application)                                          






                                          2                                           





Page:  Previous  1  2  3  4  5  6  7  8  9  10  11  12  13  14  Next 

Last modified: November 3, 2007