US3538122A
Expired / Lapsed
US
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Catalytic production of maleic anhydride
Assignee: BASF SE
•
Filing: 1969-03-12
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Granted: 1970-11-03
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Expires: 1989-03-12
Abstract
No abstract record available.
Inventors
- 👤 Wilhelm Friedrichsen
- 👤 Hans Joachim Stephan
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 05:22
CPC Classifications
C; C07; C07C; C07C51/00; C07C51/16; C07C51/31; C07C51/313; B; B01; B01J; B01J23/00; B01J23/002; B01J23/16; B01J23/24; B01J23/30; B01J27/00; B01J27/14; B01J27/186; B01J27/195; B01J27/198; B01J27/199; C07C51/21; C07C51/215; C07C51/25; C07C51/252; B01J2523/00
Claims Analysis
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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) | 1973-11-02 | 1974-05-04 | 1974-11-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1977-11-02 | 1978-05-04 | 1978-11-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1981-11-02 | 1982-05-04 | 1982-11-03 | $7700.00 | Window Closed / Lapsed |