Patent US3813381A successfully refreshed from Google Patents.
US3813381A
Expired / Lapsed
US
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Ethylene polymerization with ammonia modified catalyst
Assignee: Union Carbide Corp
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Filing: 1972-07-17
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Granted: 1974-05-28
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Expires: 1992-07-17
Abstract
Abstract SUPPORT BIS-CYCLOPENTADIENYL CHROMIUM (II) CATALYST ARE MODIFIED BY TREATMENT WITH AMMONIA IN ORDER; TO IMPROVE THE TOUGHNESS AND IMPACT STRENGTH OF THE RESULTING ETHYLENE POLYMERS MADE THEREWITH.
Inventors
- 👤 F Karol
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 20:44
CPC Classifications
C; C08; C08F; C08F10/00
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-05-27 | 1977-11-26 | 1978-05-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-05-27 | 1981-11-26 | 1982-05-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-05-27 | 1985-11-26 | 1986-05-28 | $7700.00 | Window Closed / Lapsed |