Porous glass membrane tubes
US4780369A · kind A · utility
6Cited by
8References
14Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Apr 12, 1984 |
| Grant date | Oct 25, 1988 |
| Priority date | — |
| Expiry date | Apr 12, 2004 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/2975
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
The invention relates to a process for producing a tubular glass membrane with wall thicknesses between 5 and 30 microns and reproducible pore sizes between 11 A and 50 A. Alkali borosilicate glass is drawn into discrete hollow tubes and immediately cooled. The tubes are thermally treated to effect a phase separation into a coherent silicon dioxide phase and a boron oxide phase rich in alkali borate. The boron oxide phase is leached out with mineral acid. The tubes can be subsequently treated to give enlarged or reduced pores, asymmetric pores and coated surfaces.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.