Patent US3828782A successfully refreshed from Google Patents.
US2724701A
Expired / Lapsed
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Preparation of silicic acid sols
Assignee: WR Grace and Co
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Filing: 1951-10-25
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Granted: 1955-11-22
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Expires: 1971-10-25
Abstract
No abstract record available.
Inventors
- 👤 Jr Casimer C Legal
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 07:41
CPC Classifications
C; C01; C01B; C01B33/00; C01B33/113; C01B33/12; C01B33/14; C01B33/141
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
53 words
THE METHOD OF PREPARING A SILICIC ACID SOL COMPRISING FORMING A SILICA HYDROGEL BY REACTING AN ACID WITH A WATER SOLUBLE SILICATE AT A PH ABOVE 7, WASHING SAID HYDROGEL TO REMOVE SOLUBLE CONSTITUENTS AND WITHOUT FURTHER TREATMENT THEREOF HEATING THE WASHED HYDROGEL ALONE UNDER NON-EVAPORATIVE CONDITIONS TO FORM A SILICIC ACID SOL.
Claim 2
Independent Claim
53 words
THE METHOD OF PREPARING A SILICIC ACID SOL COMPRISING FORMING A SILICA HYDROGEL BY REACTING AN ACID WITH A WATER SOLUBLE SILICATE AT A PH ABOVE 7, WASHING SAID HYDROGEL TO REMOVE SOLUBLE CONSTITUENTS AND WITHOUT FURTHER TREATMENT THEREOF HEATING THE WASHED HYDROGEL ALONE UNDER NON-EVAPORATIVE CONDITIONS TO FORM A SILICIC ACID SOL.
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) | 1958-11-21 | 1959-05-23 | 1959-11-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1962-11-21 | 1963-05-23 | 1963-11-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1966-11-21 | 1967-05-23 | 1967-11-22 | $7700.00 | Window Closed / Lapsed |