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US3682828A
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Silica gel-containing magnesia insulating composition
Assignee: Dynamit Nobel AG
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Filing: 1970-06-22
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Granted: 1972-08-08
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Expires: 1990-06-22
Abstract
Abstract AN ELECTRICAL INSULATING MATERIAL CONSISTS ESSENTIALLY OF: (1) A SINTERED MAGNESIA OF AT LEAST 94 WEIGHT PERCENT PURITY, AND (2) 0.1 TO 7 WEIGHT PERCENT OF A SILICA GEL HAVING A SPECIFIC SURFACE AREA IN THE RANGE OF 50 TO 1100 M.2/G., AND A SIZE LESS THAN 370U, PREFERABLY LESS THAN 70U. THIS INSULATING MATERIAL IS PARTICULARLY USEFUL IN THE MANUFACTURE OF TUBULAR HEATING COILS AND INSULATORS.
Inventors
- 👤 Heinrich Keddeinis
- 👤 Arnold Lenz
- 👤 Otto Bleh
- 👤 Erich Termin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 12:56
CPC Classifications
H; H05; H05B; H05B3/00; H05B3/10; H05B3/18; C; C04; C04B; C04B35/00; C04B35/01; C04B35/03; H01; H01B; H01B3/00; H01B3/002; H01B3/006; H01B3/02; H01B3/025
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) | 1975-08-08 | 1976-02-07 | 1976-08-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-08-08 | 1980-02-07 | 1980-08-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-08-08 | 1984-02-07 | 1984-08-08 | $7700.00 | Window Closed / Lapsed |