Patent US3493639A successfully refreshed from Google Patents.
US3493639A
Expired / Lapsed
US
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Process for producing pentavalent phosphorus derivatives
Assignee: Shell USA Inc
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Filing: 1966-08-30
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Granted: 1970-02-03
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Expires: 1986-08-30
Abstract
No abstract record available.
Inventors
- 👤 Peter Tavs
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 19:23
CPC Classifications
C; C07; C07F; C07F9/00; C07F9/02; C07F9/28; C07F9/50; C07F9/53; C07F9/30; C07F9/32; C07F9/38; C07F9/40
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1973-02-02 | 1973-08-04 | 1974-02-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1977-02-02 | 1977-08-04 | 1978-02-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1981-02-02 | 1981-08-04 | 1982-02-03 | $7700.00 | Window Closed / Lapsed |