Patent US6502093B1 successfully refreshed from Google Patents.
US3236594A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Manufacture of finely divided silica
Assignee: Imperial Chemical Industries Ltd
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Filing: 1963-01-24
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Granted: 1966-02-22
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Expires: 1983-01-24
Abstract
No abstract record available.
Inventors
- 👤 Ray Neil Hunter
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 11:55
CPC Classifications
C; C01; C01B; C01B33/00; C01B33/113; C01B33/12; C01B33/18; C01P; C01P2006/00; C01P2006/80; C01P2006/82
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
77 words
A PROCESS FOR MAKING FINELY DIVIDED SILICA COMPRISING ABSORBING SILICON TETRAFLUORIDE IN A LOWER ALIPHATIC ALCOHOL TO FORM A SOLUTION OF A STABLE COMPLEX, REACTING SAID SOLUTION WITH AN INORGANIC BASE CHOSEN FROM THE GROUP CONSISTING OF OXIDES AND HYDROXIDES OF ALKALI METALS AND OF ALKALINE EARTH METALS AND AMMONIUM HYDROXIDE, AND WITH AT LEAST THE STOICHIOMETRIC WEIGHT OF WATER REQUIRED TO HYDROLYSE THE SILICON TETRAFLUORIDE, AND SEPARATING SILICA FROM THE MIXTURE OF SILICA AND FLUORIDE COFORMED.
Claim 2
Dependent Claim
77 words
A PROCESS FOR MAKING FINELY DIVIDED SILICA COMPRISING ABSORBING SILICON TETRAFLUORIDE IN A LOWER ALIPHATIC ALCOHOL TO FORM A SOLUTION OF A STABLE COMPLEX, REACTING SAID SOLUTION WITH AN INORGANIC BASE CHOSEN FROM THE GROUP CONSISTING OF OXIDES AND HYDROXIDES OF ALKALI METALS AND OF ALKALINE EARTH METALS AND AMMONIUM HYDROXIDE, AND WITH AT LEAST THE STOICHIOMETRIC WEIGHT OF WATER REQUIRED TO HYDROLYSE THE SILICON TETRAFLUORIDE, AND SEPARATING SILICA FROM THE MIXTURE OF SILICA AND FLUORIDE COFORMED.
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) | 1969-02-21 | 1969-08-23 | 1970-02-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1973-02-21 | 1973-08-23 | 1974-02-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1977-02-21 | 1977-08-23 | 1978-02-22 | $7700.00 | Window Closed / Lapsed |