US3798174A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of preparing thickening grade silica composition
Assignee: WR Grace and Co Conn
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Filing: 1972-04-21
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Granted: 1974-03-19
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Expires: 1992-04-21
Abstract
Abstract THICKENING GRADES OF SILICA ARE PRODUCED BY AN INSOLUBILIZATION TECHNIQUE. THE PROCESS COMPRISES FORMING AN AMMONIATED ALKALI SILICATE SOLUTION, ACIDULATING THIS SOLUTION TO A PH OF ABOUT 10.4 TO 11 TO FORM A SILICA HYDROSOL, AND THEN PRIOR TO THE SETTING OF THIS HYDROSOL TO A HYDROGEL, RAPIDLY ADMIXING THIS HYDROSOL WITH AN AMMONIUM SALT SOLUTION. THIS ADMIXING TENDS TO FURTHER ISOLUBILIZED THE SILICA WHICH THEN FORMS AS SOFT LOOSELY AGGREGATED PARTICLES. THIS SILICA CAN THEN BE CONCURRENTLY DEAGGREGATED, AND DRIED, DRIED AND DEAGGREGATED OR DEWATERED AND DEAGGREGATED. THIS FINAL PROCESSING WILL DEPEND ON THE CHARACTISTICS OF THE SILICA TO BE PRODUCED.
Inventors
- 👤 E Acker
- 👤 R Glemza
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 02:31
CPC Classifications
C; C01; C01B; C01B33/00; C01B33/113; C01B33/12; C01B33/18; C01B33/187; C01B33/193; C08; C08K; C08K3/00; C08K3/34; C08K3/36; C01P; C01P2004/00; C01P2004/60; C01P2004/61; C01P2006/00; C01P2006/22; C01P2006/80
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) | 1977-03-18 | 1977-09-17 | 1978-03-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-03-18 | 1981-09-17 | 1982-03-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-03-18 | 1985-09-17 | 1986-03-19 | $7700.00 | Window Closed / Lapsed |