Stable colloidal silica aquasols

Abstract

A stable aquasol comprising colloidal silica having a surface area of from about 700 m 2 /g to about 1100 m 2 /g, and an S- value of from about 20 to about 50; wherein said colloidal silica is not surface treated; wherein the molar ratio of SiO 2 /Na 2 O in said colloidal silica is greater than about 13.0:1 and is less than about 17.0:1; and wherein said aquasols have a percent by weight SiO 2 solids level of from about 7.00 percent to about 16.80 percent is described and claimed. These stable colloidal silica aquasols demonstrate advantageously improved performance over art-known colloidal silica sols in applications such as in drainage and retention in papermaking processes.

What is claimed is:  
     
         1 . A stable aquasol comprising colloidal silica having a surface area of from about 700 m 2 /g to about 1100 m 2 /g, and an S-value of from about 20 to about 50; 
 wherein said colloidal silica is not surface treated; wherein the molar ratio of SiO 2 /Na 2 O in said colloidal silica is greater than about 13.0:1 and is less than about 17.0:1; and wherein said aquasols have a percent by weight SiO 2  solids level of from about 7.00 percent to about 16.80 percent.    
     
     
         2 . A stable aquasol of  claim 1  comprising colloidal silica having a surface area of from about 790 m 2 /g to about 1100 m 2 /g.  
     
     
         3 . A stable aquasol of  claim 1  comprising colloidal silica having a surface area of from about 857 m 2 /g to about 1100 m 2 /g.  
     
     
         4 . A stable aquasol of  claim 1  comprising colloidal silica having a surface area of from about 970 m 2 /g to about 1100 m 2 /g.  
     
     
         5 . A stable aquasol of  claim 1  comprising colloidal silica wherein said colloidal silica has an S-value of from about 22.5 to about 50.  
     
     
         6 . A stable aquasol of  claim 1  having a percent by weight solids content based on SiO 2  of from about 7.00 percent to about 14.00 percent.