Patent US3494780A successfully refreshed from Google Patents.
US3494780A
Expired / Lapsed
US
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Method for enhancing permeability of separatory membranes
Assignee: Dow Chemical Co
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Filing: 1966-11-04
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Granted: 1970-02-10
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Expires: 1986-11-04
Abstract
No abstract record available.
Inventors
- 👤 William Eugene Skiens
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 18:10
CPC Classifications
B; B01; B01D; B01D71/00; B01D71/06; B01D71/08; B01D71/12; B01D71/14; B01D71/16; B01D2323/00; B01D2323/12; B01D2323/15; B01D2323/20
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US2279339A
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US2460233A
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US2861039A
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US3086835A
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US2894289A
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US3140256A
Cited
US3133132A
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US3283042A
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US3344214A
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US3250701A
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US3285765A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1973-02-09 | 1973-08-11 | 1974-02-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1977-02-09 | 1977-08-11 | 1978-02-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1981-02-09 | 1981-08-11 | 1982-02-10 | $7700.00 | Window Closed / Lapsed |