Stannous compatible silica
Silica particles having a BET surface area from 0.1 to 7 m 2 /g, a pack density from 35 to 55 lb/ft 3 , an Einlehner abrasion value from 8 to 25 mg lost/100,000 revolutions, a total mercury intrusion pore volume from 0.7 to 1.2 cc/g, and a stannous compatibility from 70 to 99%, are disclosed, as well as methods for making these silica particles.
1. Silica particles having:
(i) a BET surface area in a range from 0.1 to 7 m 2 /g;
(ii) a pack density in a range from 40 to 55 lb/ft 3 ;
(iii) an Einlehner abrasion value in a range from 8 to 25 mg lost/100,000 revolutions;
(iv) a total mercury intrusion pore volume in a range from 0.7 to 1.2 cc/g;
(v) a stannous compatibility in a range from 70 to 99%;
(vi) a CPC (cetylpyridinium chloride) compatibility in a range from 70 to 95%; and
(vii) wherein the silica particles are precipitated silica particles.
2. The silica particles of claim 1 , wherein the silica particles have the BET surface area in the range from 1.5 to m 2 /g.
3. The silica particles of claim 1 , wherein the silica particles have the pack density in the range from 40 to 50 lb/ft 3 .
4. The silica particles of claim 1 , wherein the silica particles have the Einlehner abrasion value in the range from 10 to 20 mg lost/100,000 revolutions.
5. The silica particles of claim 1 , wherein:
(i) the BET surface area is in the range from 1 to 7 m 2 g;
iii) the Einlehner abrasion value is in the range from 8 to 20 mg lost/100,000 revolutions;
(iii) the total mercury intrusion pore volume is in the range from 0.75 to 1.05 cc/g; and
(iv) the stannous compatibility is in the range from 70 to 95%.
6. The silica particles of claim 1 , wherein:
(i) the BET surface area is in the range from 3 to 6 m 2 g;
(ii) the pack density is in the range from 40 to 50 lb/ft 3 ;
the Einlehner abrasion value is in the range from 10 to 20 mg lost/100,000 revolutions;
(iv) the total mercury intrusion pore volume is in the range from 0.9 to 1.1 cc/g; and
(v) the stannous compatibility is in the range from 70 to 90%.
7. The silica particles of claim 1 , wherein the silica particles have the CPC compatibility in the range from 80 to 95%.
8. The silica particles of claim 1 , wherein the silica particles have a median particle size (d50) in a range from 4 to 10 μm.
9. The silica particles of claim 1 , wherein the silica particles have a water absorption in a range from 75 to 105 cc/100 g.