US3208953A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Particulate silica and method of production
Assignee: Pure Oil Co
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Filing: 1962-03-05
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Granted: 1965-09-28
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Expires: 1982-03-05
Abstract
No abstract record available.
Inventors
- 👤 Donald L Klass
- 👤 Thomas W Martinek
- 👤 Charles T O'malley
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 15:25
CPC Classifications
C; C01; C01B; C01B33/00; C01B33/113
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
193 words
THE METHOD OF PRODUCING PARTICULATE SILICA HAVING A SURFACE MONO-LAYER COMPRISING ACID SULFATE RADICALS WHICH COMPRISES CONTACTING PARTICULATE SILICA AT A TEMPERATURE UP TO ABOUT 100*C. WITH AN ATMOSPHERE CONTAINING WATER VAPOR HAVING A PARTIAL PRESSURE GREATER THAN THE PARTIAL PRESSURE OF WATER PRESENT ON THE PARTICULATE SILICA UNTIL THE WATER CONTENT OF SAID SILICA IS AT LEAST ABOUT 12 MOLECULES OF WATER PER SQUARE MILLIMICRON OF SILICA SURFACE AREA, AGING THE RESULTANT HYDRATED SILICA TO PROMOTE THE FORMATION OF SILANOL GROUPS ON THE SURFACE THEREOF, DEHYDRATING THE RESULTANT HYDRATED SILCIA BY HEATING SAME TO TEMPERATUE OF ABOUT 100*C. TO 120*C. IN THE PRESENCE OF AN ATMOSPHERE CONTAINING WATER VAPOR AT A VAPOR PRESSURE IN EXCESS OF THE WATER VAPOR PRESSURE OF SILICA HAVING 6 TO 8 SILANOL GROUPS PER SQUARE MILIMICRON OF SURFACE AND REACTING THE RESULTANT SILANOL SILICA HAVING ABOUT 6 TO 8 SILANOL GROUPS PER SQUARE MILLIMICRON OF SURFACE AREA AND LESS THAN ABOUT 2 MOLECULES OF FREE WATER PER SQUARE MILLIMICRON OF SURFACE AREA WITH SULFUR TRIOXIDE AT A TEMPERATURE IN THE RANGE OF AMBIENT TEMPERATURE TO ABOUT 200%C. UNTIL UNREACTED SULFUR TRIOXIDE IS DETECTED IN THE EFFLUENT ATMOSPHERE.
Claim 2
Independent Claim
193 words
THE METHOD OF PRODUCING PARTICULATE SILICA HAVING A SURFACE MONO-LAYER COMPRISING ACID SULFATE RADICALS WHICH COMPRISES CONTACTING PARTICULATE SILICA AT A TEMPERATURE UP TO ABOUT 100*C. WITH AN ATMOSPHERE CONTAINING WATER VAPOR HAVING A PARTIAL PRESSURE GREATER THAN THE PARTIAL PRESSURE OF WATER PRESENT ON THE PARTICULATE SILICA UNTIL THE WATER CONTENT OF SAID SILICA IS AT LEAST ABOUT 12 MOLECULES OF WATER PER SQUARE MILLIMICRON OF SILICA SURFACE AREA, AGING THE RESULTANT HYDRATED SILICA TO PROMOTE THE FORMATION OF SILANOL GROUPS ON THE SURFACE THEREOF, DEHYDRATING THE RESULTANT HYDRATED SILCIA BY HEATING SAME TO TEMPERATUE OF ABOUT 100*C. TO 120*C. IN THE PRESENCE OF AN ATMOSPHERE CONTAINING WATER VAPOR AT A VAPOR PRESSURE IN EXCESS OF THE WATER VAPOR PRESSURE OF SILICA HAVING 6 TO 8 SILANOL GROUPS PER SQUARE MILIMICRON OF SURFACE AND REACTING THE RESULTANT SILANOL SILICA HAVING ABOUT 6 TO 8 SILANOL GROUPS PER SQUARE MILLIMICRON OF SURFACE AREA AND LESS THAN ABOUT 2 MOLECULES OF FREE WATER PER SQUARE MILLIMICRON OF SURFACE AREA WITH SULFUR TRIOXIDE AT A TEMPERATURE IN THE RANGE OF AMBIENT TEMPERATURE TO ABOUT 200%C. UNTIL UNREACTED SULFUR TRIOXIDE IS DETECTED IN THE EFFLUENT ATMOSPHERE.
References Cited (Backward Citations)
US2657149A
Cited
US2848422A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1968-09-27 | 1969-03-29 | 1969-09-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1972-09-27 | 1973-03-29 | 1973-09-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1976-09-27 | 1977-03-29 | 1977-09-28 | $7700.00 | Window Closed / Lapsed |