US2178694A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of purifying caustic soda
Assignee: PPG Industries Inc
•
Filing: 1937-10-28
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Granted: 1939-11-07
•
Expires: 1957-10-28
Abstract
No abstract record available.
Inventors
- 👤 Irving E Muskat
- 👤 William F Waldeck
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 20:16
CPC Classifications
C; C01; C01D; C01D1/00; C01D1/04; C01D1/28; C01D1/30
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) | 1942-11-06 | 1943-05-08 | 1943-11-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1946-11-06 | 1947-05-08 | 1947-11-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1950-11-06 | 1951-05-08 | 1951-11-07 | $7700.00 | Window Closed / Lapsed |