US2477638A
Expired / Lapsed
US
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Silica-zirconia catalysts and preparation thereof
Assignee: Houdry Process Corp
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Filing: 1947-03-11
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Granted: 1949-08-02
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Expires: 1967-03-11
Abstract
No abstract record available.
Inventors
- 👤 Jr Thomas H Milliken
- 👤 Mills George Alexander
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 13:07
CPC Classifications
B; B01; B01J; B01J21/00; B01J21/06; B01J21/08
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) | 1952-08-01 | 1953-01-31 | 1953-08-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1956-08-01 | 1957-01-31 | 1957-08-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1960-08-01 | 1961-01-31 | 1961-08-02 | $7700.00 | Window Closed / Lapsed |