Heat Treated Precipitated Silica

Abstract

Process for heat treating precipitated silica to improve stability. Oral care compositions comprising such heat treated precipitated silica abrasives and a stannous ion source.

We claim: 
     
         1 . An oral care composition comprising:
 (a) from about 5 wt % to about 50 wt % of heat treated precipitated silica particles by weight of the composition; and   (b) from about 0.1 wt % to about 5 wt % of a stannous ion source, by weight of the composition.   
     
     
         2 . The composition of  claim 1 , wherein the heat treated precipitated silica particles have a stannous compatibility of greater than about 64%. 
     
     
         3 . The composition of  claim 1 , wherein the heat treated precipitated silica particles have a stannous compatibility of greater than about 75%. 
     
     
         4 . The composition of  claim 1 , wherein the heat treated precipitated silica particles have a Q4 normalized integral value of Q2 greater than about 4000. 
     
     
         5 . The composition of  claim 1 , wherein the heat treated precipitated silica particles have a Q4 normalized integral value of Q2 greater than about 5000. 
     
     
         6 . The composition of  claim 1 , wherein the heat treated precipitated silica particles have a Q4 normalized integral value of Q2 greater than about 5489. 
     
     
         7 . The composition of  claim 1 , wherein the heat treated precipitated silica particles were subjected to a temperature of about 800° C. to about 1050° C. for a time period of less than about 5 minutes. 
     
     
         8 . The composition of  claim 7 , wherein the heat treated precipitated silica particles were subjected to a temperature of about 800° C. to about 1050° C. for a time period of less than about 3 minutes. 
     
     
         9 . The composition of  claim 1 , wherein the composition comprises from about 5 wt % to about 35 wt % of heat treated precipitated silica particles by weight of the composition. 
     
     
         10 . The composition of  claim 1 , wherein the composition comprises from about 1.5 wt % to about 3 wt % of a stannous ion source, by weight of the composition. 
     
     
         11 . The composition of  claim 1 , wherein the stannous ion source comprises stannous fluoride. 
     
     
         12 . The composition of  claim 1 , further comprising a gel network, wherein the gel network comprises at least one fatty amphiphile, a surfactant, and a solvent and wherein said gel network suspends said heat treated silica particles in the dentifrice and keeps said particles suspended when the composition is diluted in-use by water in the mouth. 
     
     
         13 . An oral care composition comprising:
 (a) from about 5 wt % to about 50 wt % of heat treated precipitated silica particles by weight of the composition;   (b) from about 0.1 wt % to about 5 wt % of a stannous ion source, by weight of the composition, and   wherein the said heat treated precipitated silica particles were heat treated by subjecting the precipitated silica particles to a temperature of about 800° C. to about 1050° C. for a time period of less than about 5 minutes.   
     
     
         14 . The oral care composition of  claim 13 , wherein the heat treated precipitated silica particles have a Q4 normalized integral value of Q2 greater than about 4000. 
     
     
         15 . The oral care composition of  claim 13 , wherein the heat treated precipitated silica particles have a Q4 normalized integral value of Q2 greater than about 5000. 
     
     
         16 . The oral care composition of  claim 13 , wherein the heat treated precipitated silica particles have a Q4 normalized integral value of Q2 greater than about 5489. 
     
     
         17 . The oral care composition of  claim 13 , wherein the heat treated precipitated silica particles have a stannous compatibility of greater than about 64%. 
     
     
         18 . The oral care composition of  claim 13 , wherein the heat treated precipitated silica particles have a stannous compatibility of greater than about 75%. 
     
     
         19 . The composition of  claim 13 , wherein the stannous ion source comprises stannous fluoride. 
     
     
         20 . An oral care composition comprising:
 (a) from about 5 wt % to about 50 wt % of heat treated precipitated silica particles by weight of the composition;   (b) from about 1.5 wt % to about 3 wt % of stannous fluoride, by weight of the composition,   wherein the said heat treated precipitated silica particles were heat treated by subjecting the precipitated silica particles to a temperature of about 800° C. to about 1050° C. for a time period of less than about 5 minutes;   wherein the heat treated precipitated silica particles have a Q4 normalized integral value of Q2 greater than about 5489; and   wherein the oral care composition is a dentifrice.