Silica capable of being used in toothpaste compositions
US6187292A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 19, 1999 |
| Grant date | Feb 13, 2001 |
| Priority date | — |
| Expiry date | Feb 19, 2019 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC01P2006/19
- WIPO fieldPharmaceuticals
- WIPO sectorChemistry
Abstract
The invention discloses an abrasive precipitation silica useable in toothpaste compositions, said silica having a BET specific surface ranging from 15 to 300 m.sup.2 /g, a DOP oil absorption ranging from 40 to 160 ml/g, a median particle diameter of at least 10 .mu.m, generally ranging from 12 to 30 .mu.m, a particle cohesion factor of at least 85% about for a median particle diameter ranging from 12 to 20 .mu.m. Method for preparing silica by reacting an alkaline metal silicate with an acidifying agent, to form a silica slurry, separating and optionally drying the recuperated silica suspension, the operation for forming the slurry being effected according to the following steps: a first step consisting in using one initial heel solution constituted of water, an electrolyte salt of the alkaline or alkaline-earth metal group and optionally of one acidobasic agent; a second step consisting in introducing the silicate and the acidifying agent, the reaction medium pH remaining constant from 4 to 7 and particularly from 5.8 to 6.7; and a third optional step, consisting in acidifying the reaction medium until a silica slurry with a pH of less than 6 and particularly of 4 is obtained. The…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.