Hollow ceramic microspheres by sol-gel dehydration with improved control over size and morphology
US5492870A · kind A · utility
44Cited by
2References
25Claims
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Key dates
| Filing date | Apr 13, 1994 |
| Grant date | Feb 20, 1996 |
| Priority date | — |
| Expiry date | Apr 13, 2014 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/2984
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
Hollow microspheres of ceramic material are formed by a sol-gel technique involving forming and stabilizing an emulsion of an aqueous sol of the ceramic material in an organic phase, followed by dehydration of the stabilized emulsion droplets by extraction using a water-absorbing organic liquid, to form hollow gelled spheres, and finally recovery, drying and calcination of the spheres to the final product. The separation of the emulsion formation and dehydration steps into two distinct stages results in the ultimate formation of microspheres with improved uniformity and size distribution.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.