US3681017A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Platelet silica,its production and uses
Assignee: WR Grace and Co
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Filing: 1970-07-06
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Granted: 1972-08-01
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Expires: 1990-07-06
Abstract
Abstract MICROPOROUS PLATLET SILICA IS PREPARED FROM THE AMMONIUM FORM OF SODIUM SILICATE (I) BY FREEZE-DRYING AND FILTRATION OR (II) BY FREEZING AND THAWING AND FILTRATION, OR (III) BY LOWERING THE PH AND REPEATING (II). THE RESULTANT UNITARY, POLYMERIC, MICROPOROUS SILICA PLATELETS CAN BE USED AS FILLERS IN HIGH GLOSS FILMS.
Inventors
- 👤 Howard J Butcher
- 👤 Edgar Alan Simpson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 21:15
CPC Classifications
C; C01; C01B; C01B33/00; C01B33/113; C01B33/12; C01B33/14; C01B33/141; C01B33/142; C01B33/143; C01B33/1435; C01B33/152; C09; C09C; C09C1/00; C09C1/0015; C09C1/0018; C09C1/28; C09C1/30; C01P; C01P2004/00; C01P2004/20
Claims Analysis
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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) | 1975-08-01 | 1976-01-31 | 1976-08-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-08-01 | 1980-01-31 | 1980-08-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-08-01 | 1984-01-31 | 1984-08-01 | $7700.00 | Window Closed / Lapsed |