US3634548A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Polystyrene-ethylene graft copolymer
Assignee: Gulf Research and Development Co
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Filing: 1969-08-11
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Granted: 1972-01-11
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Expires: 1989-08-11
Abstract
Abstract A GRAFT COPOLYMER OF ETHYLENE ONTO THE ALIPHATIC CARBON BACKBONE PORTION OF POLYSTYRENE IS FORMED BY CONTACTING POLYSTYRENE IN AN INERT HYDROCARBON MEDIUM WITH A COMPLEX OF AN ALKYL LITHIUM WITH A CHELATING DITERTIARY AMINE, THEN CONTACTING THE POLYSTYRENE CONTAINING REACTIVE SITES WITH ETHYLENE.
Inventors
- 👤 Kenneth E Harwell
- 👤 Francis R Galiano
- 👤 Prairie Village
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 20:03
CPC Classifications
C; C08; C08F; C08F257/00; C08F257/02
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) | 1975-01-10 | 1975-07-12 | 1976-01-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-01-10 | 1979-07-12 | 1980-01-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-01-10 | 1983-07-12 | 1984-01-11 | $7700.00 | Window Closed / Lapsed |