US3673104A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of preparing silica sols containing large particle size silica
Assignee: ChampionX LLC
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Filing: 1969-04-28
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Granted: 1972-06-27
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Expires: 1989-04-28
Abstract
Abstract Method for preparing aqueous stable silica sols containing at least 40 percent by weight of silica in the form of large, discrete, spherical particles having a weight-average particle diameter of from 45 to 100 millimicrons. An aqueous acid silica sol feed is added at a critical maximum feed rate to an aqueous alkaline silica sol containing particles having a weight-average diameter of from about 10 to 30 millimicrons while the aqueous liquid phase thereof is continuously evaporated. The pH of the alkaline sol during the whole of the addition is maintained at a value of at least 7.0.
Inventors
- 👤 William L Albrecht
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 05:04
CPC Classifications
C; C01; C01B; C01B33/00; C01B33/113; C01B33/12; C01B33/14; C01B33/146; C01B33/151
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
19 words
The method of claim 1 where the aqueous stable silica sols prepared contain 40-70 percent by weight silica particles.
Claim 2
Dependent Claim
17 words
The method of claim 1 where the aqueous stable silica sols are prepared through constant volume evaporation.
References Cited (Backward Citations)
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 |