US2698330A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Production of phthalic anhydride and abrasion-resistant fluid catalyst therefor
Assignee: Wyeth Holdings LLC
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Filing: 1950-12-08
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Granted: 1954-12-28
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Expires: 1970-12-08
Abstract
No abstract record available.
Inventors
- 👤 Wesley O Fugate
- 👤 Samuel W Tribit
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 11:38
CPC Classifications
B; B01; B01J; B01J23/00; B01J23/38; B01J23/54; B01J23/66; B01J23/68; B01J23/682; B01J23/16; B01J23/20; B01J23/22; B01J8/00; B01J8/18; B01J8/24; C; C07; C07C; C07C51/00; C07C51/16; C07C51/31; C07C51/313
Claims Analysis
Total Claims: 1
Claim 1
Independent Claim
114 words
A METHOD FOR THE VAPOR PHASE CATALYTIC OXIDATION OF NAPHTHALENE OF PHTHALIC ANHYDRIDE WHICH COMPRISES PASSING A MIXTURE OF NAPHTHALENE VAPOR AND AIR HAVING A RATIO OF ABOUT 1 TO 2 MOL PERCENT OF NAPHTHALENE IN AIR THROUGH A FLUIDIZED MASS OF PARTICLES OF FINELY DIVIDED VANADIUM OXIDE CATALYST MAINTAINED AT A TEMPERATURE BETWEEN 330* AND 370* C., SAID CATALYST BEING COMPOSED OF ABOUT 40% TO 75% BY WEIGHT OF A CALCINED GEL OF SILICA IMPREGNATED UNIFORMLY WITH ABOUT 20% TO 50% OF A POTASSIUM SULFATE, ABOUT 3% TO 25% OF A VANADIUM OXIDE AND FROM 0.05% TO ABOUT 5% OF AN OXIDE OF A METAL SELECTED FROM THE GROUP CONSISTING OF SILVER AND
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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) | 1957-12-27 | 1958-06-28 | 1958-12-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1961-12-27 | 1962-06-28 | 1962-12-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1965-12-27 | 1966-06-28 | 1966-12-28 | $7700.00 | Window Closed / Lapsed |