Patent US2602341A successfully refreshed from Google Patents.
Patent US2938890A successfully refreshed from Google Patents.
US2938890A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Polyethylene process
Assignee: WR Grace and Co
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Filing: 1957-10-30
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Granted: 1960-05-31
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Expires: 1977-10-30
Abstract
No abstract record available.
Inventors
- 👤 Alelio Gaetano F D
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 07:22
CPC Classifications
C; C08; C08F; C08F10/00
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
86 words
THE METHOD OF PREPARING A NORMALLY SOLID POLYETHYLENE COMPRISING SUBJECTING ETHYLENE AT A TEMPERATURE IN THE RANGE OF 20-250*C. AT SUPERATMOSPHERIC PRESSURE IN AN INERT SOLVENT TO THE ACTION OF A CATALYST FORMED BY HEATING TOGETHER, AS THE SOLE CATALYST-FORMING REACTANTS, CR AND TICL4 AT A TEMPERATURE OF AT LEAST ABOUT 130*C., SAID CATALYST REACTION PRODUCT CONSISTING ESSENTIALLY OF A MIXTURE OF CHROMIUM AND CHLORIDES OF TITANIUM AND CHROMIUM, WHICH MIXTURE PRIOR TO USE IS WASHED SUBSTANTIALLY FREE OF HYDROCARBON-SOLUBLE CHLORIDES WITH AN INERT HYDROCARBON SOLVENT.
Claim 2
Independent Claim
86 words
THE METHOD OF PREPARING A NORMALLY SOLID POLYETHYLENE COMPRISING SUBJECTING ETHYLENE AT A TEMPERATURE IN THE RANGE OF 20-250*C. AT SUPERATMOSPHERIC PRESSURE IN AN INERT SOLVENT TO THE ACTION OF A CATALYST FORMED BY HEATING TOGETHER, AS THE SOLE CATALYST-FORMING REACTANTS, CR AND TICL4 AT A TEMPERATURE OF AT LEAST ABOUT 130*C., SAID CATALYST REACTION PRODUCT CONSISTING ESSENTIALLY OF A MIXTURE OF CHROMIUM AND CHLORIDES OF TITANIUM AND CHROMIUM, WHICH MIXTURE PRIOR TO USE IS WASHED SUBSTANTIALLY FREE OF HYDROCARBON-SOLUBLE CHLORIDES WITH AN INERT HYDROCARBON SOLVENT.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1963-05-31 | 1963-11-30 | 1964-05-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1967-05-31 | 1967-11-30 | 1968-05-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1971-05-31 | 1971-11-30 | 1972-05-31 | $7700.00 | Window Closed / Lapsed |