Patent US3790495A successfully refreshed from Google Patents.
US3790495A
Expired / Lapsed
US
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Process for the manufacture of colloidal fibrous boehmite
Assignee: Bayer AG
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Filing: 1972-01-31
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Granted: 1974-02-05
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Expires: 1992-01-31
Abstract
Abstract THE PRESENT INVENTION RELATES TO A PROCESS FOR THE PRODUCTION OF COLLOIDAL FIBROUS BOEHMITE (ALO(OH)) WHEREIN ACTIVE ALUMINUM OXIDE HAVING A RESIDUAL WATER CONTENT OF FROM 2 TO 15% BY WEIGHT OBTAINED BY INCOMPLETE DEHYDRATION OF HYDRARGILLITE IS REACTED IN AN AQUEOUS SLURRY WITH A MONOBASIC ORGANIC ACID TO GIVE THE CORRESPONDING BASIC AL-SALT AND SUBSEQUENTLY SAID BASIC AL-SALT IS SUBJECTED TO HYDROTHERMAL TREATMENT AT 120-200*C. AND 215 ATMOSPHERE PRESSURE IN AN AQUEOUS SUSPENSION HAVING A CONCENTRATION OF FROM 2 TO 20% BY WEIGHT OF AL2O3 UNTIL A COLLOIDAL FIBROUS BOEHMITE SOLUTION HAS BEEN FORMED.
Inventors
- 👤 E Podschus
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 07:57
CPC Classifications
C; C01; C01F; C01F7/00; C01F7/02; C01F7/34; C01F7/36; C01P; C01P2004/00; C01P2004/10; C01P2006/00; C01P2006/12
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) | 1977-02-04 | 1977-08-06 | 1978-02-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-02-04 | 1981-08-06 | 1982-02-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-02-04 | 1985-08-06 | 1986-02-05 | $7700.00 | Window Closed / Lapsed |