Patent US3787561A successfully refreshed from Google Patents.
US3787561A
Expired / Lapsed
US
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Loosely aggregated 100 millimicron micellular silica
Assignee: WR Grace and Co Conn
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Filing: 1971-05-05
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Granted: 1974-01-22
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Expires: 1991-05-05
Abstract
Abstract ULTRAFINE SILICA MATERIALS ARE PRODUCED BY FIRST FORMING A LOSSELY AGGREGATED APPROXIMATELY 100 MILLIMICRON MICELLULAR SILICA AND FLUID ENERGY MILLING THIS SILICA TO AND ULTRAFINE SILICA. THE LOOSELY AGGREGATED 100 MILLIMICRON MICELLULAR SILICA IS PRODUCED BY ACID NEUTRALIZING A CONCENTRATED SILICATE SOLUTION IN A TWO STEP PROCEDURE FOLLOWED BY A HOT AGING AT ABOUT 70 TO 100*C. FOR 1/4 TO 5 HOURS TO YIELD THE SILICA PRODUCT. THIS SILICA IS WASHED AND THEN MAY BE DRIED OR DIRECTLY FED TO A FLUID ENERGY MILL FOR DEAGGREGATION AND DRYING TO FORM THE ULTRAFINE SIZE SILICA.
Inventors
- 👤 E Acker
- 👤 M Winyall
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 09:51
CPC Classifications
C; C01; C01B; C01B33/00; C01B33/113; C01B33/12; C01B33/18; C01B33/187; C01B33/193; C01P; C01P2004/00; C01P2004/50; C01P2004/60; C01P2004/61; C01P2006/00; C01P2006/12; C01P2006/14
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) | 1977-01-21 | 1977-07-23 | 1978-01-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-01-21 | 1981-07-23 | 1982-01-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-01-21 | 1985-07-23 | 1986-01-22 | $7700.00 | Window Closed / Lapsed |