US3672833A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of preparing inorganic aerogels
Assignee: Direction Générale de l'Armement
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Filing: 1971-02-08
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Granted: 1972-06-27
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Expires: 1991-02-08
Abstract
Abstract SILICA AEROGELS ARE PREAPRED BY HYDROLYZING A LOWER ALKYL ORTHOSILICATE IN AN ALIPHATIC ALCOHOL HAVING 1-4 CARBON ATOMS WITH ONE TO FIVE TIMES THE STOICHIOMETRIC QUANTITY OF WATER REQUIRED TO EFFECT HYDROLYZATION. IN A SEPARATE VESSEL, A SUPPLEMENTARY AMOUNT OF THE SAME ALCOHOL IS ADDED AND THE CONTENTS OF BOTH VESSELS ARE GRADUALLY HEATED TO A TEMPERATURE ABOVE THE CRITICAL POINT. THE PRESSURE IS GRADUALLY RELEASED AND WATER AND ALCOHOL VAPORS ARE WASHED OUT WITH DRY INERT GAS. THE AUTOCLAVE IS THEN RESEALED AND COOLED TO ROOM TEMPERATURE AND THE RESULTING AEROGEL IS COLLECTED.
Inventors
- 👤 Stanislas Jean Teichner
- 👤 Gilbert Andre Nicolaon
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 18:33
CPC Classifications
B; B01; B01J; B01J13/00; B01J13/0091; C; C01; C01B; C01B33/00; C01B33/113; C01B33/12; C01B33/14; C01B33/157; C01B33/158; C01B33/1585
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-06-27 | 1975-12-27 | 1976-06-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-06-27 | 1979-12-27 | 1980-06-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-06-27 | 1983-12-27 | 1984-06-27 | $7700.00 | Window Closed / Lapsed |