Silicas
US4992251A · kind A · utility
25Cited by
3References
9Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Sep 15, 1988 |
| Grant date | Feb 12, 1991 |
| Priority date | — |
| Expiry date | Sep 15, 2008 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC01P2006/90
- WIPO fieldPharmaceuticals
- WIPO sectorChemistry
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 420 to 550 m.sup.2 /g, a weight mean particle size of 5 to 20 micron, a perspex abrasion value of 15 to 28, a mean pore diameter from 3 to 8 nm and a transmission of at least 70% in the R1 range from 1.444 to 1.460.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.