Patent US2425398A successfully refreshed from Google Patents.
US2425398A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Manufacture of phthalic anhydride
Assignee: Sherwin Williams Co
•
Filing: 1942-04-17
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Granted: 1947-08-12
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Expires: 1962-04-17
Abstract
No abstract record available.
Inventors
- 👤 Robert F Ruthruff
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 14:18
CPC Classifications
C; C07; C07C; C07C51/00; C07C51/16; C07C51/31; C07C51/313
Claims Analysis
Total Claims: 0
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1950-08-11 | 1951-02-10 | 1951-08-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1954-08-11 | 1955-02-10 | 1955-08-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1958-08-11 | 1959-02-10 | 1959-08-12 | $7700.00 | Window Closed / Lapsed |