Patent US3775344A successfully refreshed from Google Patents.
US3775344A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Active carbon having a hollow microspherical structure
Assignee: Kureha Corp
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Filing: 1971-09-16
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Granted: 1973-11-27
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Expires: 1991-09-16
Abstract
Abstract ACTIVE CARBON HAVING A HOLLOW MICROSPHERICAL STRUCTURE IS PROVIDED BY SUBJECTING CARBON HAVING A HOLLOW MICROSPHERICAL STRUCTURE TO ACTIVATION CONDUCTED AT 400-1000* C. IN AN ATMOSPHERE OF AIR, STEAM OR CARBON DIOXIDE.
Inventors
- 👤 Y Amagi
- 👤 R Takahashi
- 👤 M Wagu
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 18:54
CPC Classifications
C; C01; C01B; C01B32/00; C01B32/30; C01B32/354; C01B32/382
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) | 1976-11-26 | 1977-05-28 | 1977-11-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-11-26 | 1981-05-28 | 1981-11-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-11-26 | 1985-05-28 | 1985-11-27 | $7700.00 | Window Closed / Lapsed |