US2865779A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Silica pigment and preparation thereof
Assignee: Columbia Southern Chemical Corp
•
Filing: 1955-06-24
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Granted: 1958-12-23
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Expires: 1975-06-24
Abstract
No abstract record available.
Inventors
- 👤 Edward M Allen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 16:50
CPC Classifications
C; C09; C09C; C09C1/00; C09C1/0081; B; B82; B82Y; B82Y30/00; C01; C01B; C01B33/00; C01B33/113; C08; C08K; C08K3/00; C08K3/30; C08K3/34; C08K9/00; C08K9/02; C01P; C01P2004/00; C01P2004/50; C01P2004/60; C01P2004/61; C01P2004/62; C01P2004/64; C01P2004/80; C01P2006/00; C01P2006/12; C01P2006/22
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
73 words
A METHOD OF PREPARING A FINELY-DIVIDED SILICA-ALKALINE EARTH METAL SULFITE PIGMENT WHICH COMPRISES FORMING AN AQUEOUS SLURRY OF FINELY-DIVIDED, PRECIPITATED SILICA HAVING AN AVERAGE ULTIMATE PARTICLE SIZE BELOW 0.1 MICRON HAVING DISSOLVED AND DISPERSED THEREIN ALKALINE EARTH METAL IONS AND SULFITE IONS, THE SLURRY HAVING A PH FROM ABOUT 1.5 TO ABOUT 6, AND REDUCING THE ACIDITY OF THE SLURRY TO A PH ABOVE 6.5 TO PRECIPITATE A FINELY-DIVIDED, SILICA-ALKALINE EARTH METAL SULFITE.
Claim 2
Independent Claim
73 words
A METHOD OF PREPARING A FINELY-DIVIDED SILICA-ALKALINE EARTH METAL SULFITE PIGMENT WHICH COMPRISES FORMING AN AQUEOUS SLURRY OF FINELY-DIVIDED, PRECIPITATED SILICA HAVING AN AVERAGE ULTIMATE PARTICLE SIZE BELOW 0.1 MICRON HAVING DISSOLVED AND DISPERSED THEREIN ALKALINE EARTH METAL IONS AND SULFITE IONS, THE SLURRY HAVING A PH FROM ABOUT 1.5 TO ABOUT 6, AND REDUCING THE ACIDITY OF THE SLURRY TO A PH ABOVE 6.5 TO PRECIPITATE A FINELY-DIVIDED, SILICA-ALKALINE EARTH METAL SULFITE.
References Cited (Backward Citations)
US1984188A
Cited
US2189832A
Cited
US2413321A
Cited
US2310693A
Cited
US2686731A
Cited
US2679463A
Cited
US2698256A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1961-12-22 | 1962-06-23 | 1962-12-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1965-12-22 | 1966-06-23 | 1966-12-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1969-12-22 | 1970-06-23 | 1970-12-23 | $7700.00 | Window Closed / Lapsed |