Method of preparing high-purity aqueous silica sol
US5100581A · kind A · utility
51Cited by
6References
11Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Mar 20, 1990 |
| Grant date | Mar 31, 1992 |
| Priority date | — |
| Expiry date | Mar 20, 2010 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC01B33/148
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
A high-purity stable aqueous silica sol is prepared which has an SiO.sub.2 concentration of from 30 to 50% by weight and which is substantially free from any other polyvalent metal oxides than silica and in which the colloidal silica has a mean particle size falling within the range of from 10 to 30 millimicrons. The silica sol obtained by the method of the present invention has an extremely low content of oxides of polyvalent metals such as iron or aluminum and may therefore be employed for uses which require the absence of such metals in the silica sol, for example, as an abrasive for semiconductors.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.