US4941893B1
Expired / Lapsed
US
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Gas separation by semi-permeable membranes
Assignee: Advanced Silicon Materials Inc A Corp Of De
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Filing: 1989-09-19
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Granted: 1996-07-30
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Expires: 2009-09-19
Abstract
No abstract record available.
Inventors
- 👤 Shan-Tao Hsieh
- 👤 George E Ii Keller
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 12:10
CPC Classifications
C; C01; C01B; C01B3/00; C01B3/50; C30; C30B; C30B29/00; C30B29/02; C30B29/06; B; B01; B01D; B01D53/00; B01D53/22; B01D53/228; B01D69/00; B01D69/12; B01D69/1213; C01B3/501; C01B3/503; C01B33/00; C01B33/02; C01B33/021; C01B33/027; C01B33/029; C01B33/03; C01B33/035; C01B33/04; C01B33/043; C01B33/08; C01B33/107; C01B33/1071; C01B33/10742; C01B33/10757; C01B33/10763; C01B7/00; C30B25/00; C30B25/02; C01B2203/00; C01B2203/04; C01B2203/0405; C01B2203/0465
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1999-07-30 | 2000-01-29 | 2000-07-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2003-07-30 | 2004-01-29 | 2004-07-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2007-07-30 | 2008-01-29 | 2008-07-30 | $7700.00 | Window Closed / Lapsed |