Patent US2210059A successfully refreshed from Google Patents.
US2815352A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Production of phthalic anhydride
Assignee: —
•
Filing: —
•
Granted: 1957-12-03
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Expires: 1974-12-03
Abstract
No abstract record available.
Inventors
No inventors recorded.
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 04:48
CPC Classifications
B; B01; B01J; B01J23/00; B01J23/002; C; C07; C07C; C07C51/00; C07C51/16; C07C51/21; C07C51/255; C07C51/265; C07C51/31; C07C51/313; C07C63/00; C07C63/14; C07C63/15; C07C63/16; C07D; C07D307/00; C07D307/77; C07D307/87; C07D307/89
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
68 words
IN A PROCESS OF MANUFACTURING PHTHALIC ANHYDRIDE WHEREIN NAPHTHALENE IS OXIDIZED IN VAPOR PHASE WITH AIR IN A FLUIDIZED SOLID CATALYST REACTION ZONE TO PRODUCE A VAPOROUS-GASEOUS REACTION MIXTURE CONTAINING PHTHALIC ANHYDRIDE THE IMPROVEMENT WHICH COMPRISES PARTLY SELARATING PHTHALIC ANHYCLING FROM THE VAPOROUS-GASEOUS REACTION MIXTURE, RECYCLING THE REDIDUAL PORTION OF SAID REACTION MIXTURE OF SAID REACTION ZONE, AND SUPPLYING A FRESH AMOUNT OF NAPHTHALENE TO SAID RESIDUAL PORTION.
Claim 2
Dependent Claim
68 words
IN A PROCESS OF MANUFACTURING PHTHALIC ANHYDRIDE WHEREIN NAPHTHALENE IS OXIDIZED IN VAPOR PHASE WITH AIR IN A FLUIDIZED SOLID CATALYST REACTION ZONE TO PRODUCE A VAPOROUS-GASEOUS REACTION MIXTURE CONTAINING PHTHALIC ANHYDRIDE THE IMPROVEMENT WHICH COMPRISES PARTLY SELARATING PHTHALIC ANHYCLING FROM THE VAPOROUS-GASEOUS REACTION MIXTURE, RECYCLING THE REDIDUAL PORTION OF SAID REACTION MIXTURE OF SAID REACTION ZONE, AND SUPPLYING A FRESH AMOUNT OF NAPHTHALENE TO SAID RESIDUAL PORTION.
References Cited (Backward Citations)
US1321959A
Cited
US2489347A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1960-12-02 | 1961-06-03 | 1961-12-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1964-12-02 | 1965-06-03 | 1965-12-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1968-12-02 | 1969-06-03 | 1969-12-03 | $7700.00 | Window Closed / Lapsed |