Patent US2198223A successfully refreshed from Google Patents.
US2198223A
Expired / Lapsed
US
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Preparation of calcium carbonate
Assignee: PPG Industries Inc
•
Filing: 1938-08-10
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Granted: 1940-04-23
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Expires: 1958-08-10
Abstract
No abstract record available.
Inventors
- 👤 Irving E Muskat
- 👤 Gage Frederick
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 15:58
CPC Classifications
C; C01; C01F; C01F11/00; C01F11/18; C01F11/185; C09; C09C; C09C1/00; C09C1/02; C09C1/021; C09C1/022; C01P; C01P2004/00; C01P2004/60; C01P2004/62
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1943-04-23 | 1943-10-23 | 1944-04-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1947-04-23 | 1947-10-23 | 1948-04-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1951-04-23 | 1951-10-23 | 1952-04-23 | $7700.00 | Window Closed / Lapsed |