Method for making low sodium hollow glass microspheres
US5176732A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 10, 1991 |
| Grant date | Jan 5, 1993 |
| Priority date | — |
| Expiry date | Sep 10, 2011 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC03B19/1065
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
Low sodium hollow glass microspheres containing less than about 3 wt. % Na.sub.2 O are produced from aqueous precursors. The method comprises PA0 a) forming an aqueous glass precursor solution or slurry by combining sources of cations contained in the glass, the solution or slurry comprising all of the glass cations in proportions substantially identical to those in the glass, PA0 b) forming the solution or slurry into droplets, and PA0 c) heating the droplets to form the microspheres. The precursor may also contain surfactants, blowing agents or other known expedients. Nonionic fluorocarbon surfactants are preferred. The droplets may be formed by spraying or any other known technique. The droplets may be spray dried prior to heating step c).
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.