US3428423A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for the removal and recovery of promoter from crude phthalic anhydride made by the vapor phase oxidation of orthoxylene in the presence of promoter
Assignee: CHEM PROCESS CORP
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Filing: 1966-06-07
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Granted: 1969-02-18
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Expires: 1986-06-07
Abstract
No abstract record available.
Inventors
- 👤 Robert B Egbert
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 14:04
CPC Classifications
C; C07; C07C; C07C51/00; C07C51/16; C07C51/21; C07C51/255; C07C51/265; C01; C01B; C01B7/00; C01B7/09; C01B7/093; C07C51/54; C07C51/573
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) | 1972-02-18 | 1972-08-19 | 1973-02-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1976-02-18 | 1976-08-19 | 1977-02-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1980-02-18 | 1980-08-19 | 1981-02-18 | $7700.00 | Window Closed / Lapsed |