Precipitated silicas having improved dentifrice performance characteristics and methods of preparation
US5891421A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 22, 1996 |
| Grant date | Apr 6, 1999 |
| Priority date | — |
| Expiry date | Mar 22, 2016 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC01P2006/90
- WIPO fieldPharmaceuticals
- WIPO sectorChemistry
Abstract
Precipitated silica compositions, and methods for making the same, with improved dentifrice performance characteristics. In particular, precipitated silica compositions of the present invention have a 40% slurry viscosity build of less than approximately 20,000 centipoise and a 10% Brass Einlehner abrasion value of approximately 2.5 to 20.0 mg loss/100,000 rev. Precipitated silica compositions of the present invention also have reactor slurry average particle sizes (50%) of approximately 10 to 50 .mu.m. Methods for preparing precipitated silicas of the present invention include the steps of: (a) adding sodium silicate and a mineral acid to a reactor, thereby initiating a precipitation reaction between the reactor contents; and (b) subjecting the reactor contents to shearing forces as the reaction proceeds.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.