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US 5,512,271 AGranted
Silicas for use in transparent toothpaste compositions
AssigneeUnilever Patent Holdings B.V.
InventorsIan P. McKeown, Peter W. Stanier
Life of this patent
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Abstract
Amorphous silicas suitable for use as abrasives in transparent toothpastes can be prepared by a precipitation route. These silicas are distinguished by having a BET surface area of 100 to 450 m.sup.2 /g, a weight mean particle size of 5 to 15 microns, a plastics abrasion value of 16 to 26, a mean pore diameter from 2 to 12 nm, a transmission of at least 70% in the refractive index range from 1.430 to 1.443 and an oil absorption in the range from about 70 to about 130 cm.sup.3 /g.
Claims11
An amorphous precipitated silica having
- i) a BET surface area in the range from about 100 to 262 m.sup.2 /g,
- ii) a weight mean particle size in the range 5 microns to 15 microns, with less than 10% of the weight particle size distribution greater than 20 microns,
- iii) a plastics abrasion value in the range from 16 to 26,
- iv) a mean pore diameter in the range from 2 nm to 12 nm,
- v) a transmission of at least about 70% in the refractive index range of 1.430 to 1.443, and
- vi) an oil absorption in the range from 70 to 130 cm.sup.3 /100 g, said silica being suitable for use as an abrasive in a transparent toothpaste.
3 more elements
Dependencies are inferred from the claim text.