Patent US3743709A successfully refreshed from Google Patents.
US3743709A
Expired / Lapsed
US
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Preparation of highly porous alumina
Assignee: Canadian Patents and Development Ltd
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Filing: 1971-07-12
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Granted: 1973-07-03
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Expires: 1991-07-12
Abstract
Abstract PREPARATION OF LOW DENSITY HIGHLY POROUS ALUMINAS HAING LARGE PORES BY INITIALLY DRYING A NEUTRAL (CARBONATE) GEL OF ALUMINUM HYDROXIDE WITH THE GEL TEMPERATURE NOT EXCEEDING ABOUT 100*C. UNTIL AT LEAST ABOUT 25% BY WT. OF THE WATER HAS BEEN REMOVED, FOLLOWED BY FURTHER DRYING AND CALCINING.
Inventors
- 👤 G Shaw
- 👤 B Parsons
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 14:51
CPC Classifications
B; B01; B01J; B01J35/00; B01J35/60; B01J37/00; B01J37/08; C; C01; C01F; C01F7/00; C01F7/02; C01F7/34; B01J35/63; B01J35/638; B01J35/64; B01J35/651; C01P; C01P2006/00; C01P2006/14
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) | 1976-07-02 | 1977-01-01 | 1977-07-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-07-02 | 1981-01-01 | 1981-07-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-07-02 | 1985-01-01 | 1985-07-03 | $7700.00 | Window Closed / Lapsed |