US 12,215,034 B2
Spherical stannous compatible silica particles for reduced RDA
Karl W. Gallis, Perryville, MD (US); William J. Hagar, Perryville, MD (US); Terry W. Nassivera, Gambrills, MD (US); Lawrence Edward Dolan, Cincinnati, OH (US); Sanjeev Midha, Mason, OH (US); and Eva Schneiderman, Mason, OH (US)
Assigned to Evonik Operations GmbH, Essen (DE)
Appl. No. 17/251,334
Filed by Evonik Operations GmbH, Essen (DE)
PCT Filed Jun. 12, 2019, PCT No. PCT/EP2019/065389
§ 371(c)(1), (2) Date Dec. 11, 2020,
PCT Pub. No. WO2019/238777, PCT Pub. Date Dec. 19, 2019.
Claims priority of provisional application 62/684,073, filed on Jun. 12, 2018.
Prior Publication US 2021/0309529 A1, Oct. 7, 2021
This patent is subject to a terminal disclaimer.
Int. Cl. C01B 33/187 (2006.01)
CPC C01B 33/187 (2013.01) [C01P 2004/32 (2013.01); C01P 2004/61 (2013.01); C01P 2006/10 (2013.01); C01P 2006/12 (2013.01); C01P 2006/14 (2013.01)] 18 Claims
OG exemplary drawing
 
1. Silica particles, characterized by:
(i) a d50 median particle size in a range of from 8 to 20 μm;
(ii) a sphericity factor (S80) of greater than or equal to 0.9;
(iii) a BET surface area in a range of from 0.1 to 8 m2/g;
(iv) a total mercury intrusion pore volume in a range of from 0.35 to 0.7 cc/g; and
(v) a loss on ignition (LOI) in a range from 3 to 7 wt. %,
wherein the silica particles have a pack density in a range of from 61 to 68 lb/ft3, and
wherein the silica particles have an Einlehner abrasion value in a range of from 11 to 17 mg lost/100,000 revolutions, and
wherein the silica particles have a ratio of (d90−d10)/d50 in a range of from 1.1 to 2.2.