Patent US3781247A successfully refreshed from Google Patents.
US3781247A
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US
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Pyrolytic polymerization catalyst
Assignee: Northrop Grumman Space and Mission Systems Corp
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Filing: 1972-02-01
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Granted: 1973-12-25
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Expires: 1992-02-01
Abstract
Abstract POLYMERIZATION TIMES AND TEMPERATURES FOR ALICYCLIC ENDO CAPPED PREPOLYMERS ARE REDUCED BY THE INCLUSION OF A LEWIS ACID-TYPE CATALYST. EFFECTIVE AMOUNTS RANGING PREFERABLY 1% TO 3% BY WEIGHT OF A LEWIS ACID SELECTED FROM ANY OF THE ALKYL DERIVATIVES OF OR THE HALIDE SALTS OF TIN, ALUMINUM, ZIRCONIUM, ZINC, VANADIUM, ANTIMONY, GERMANIUM, OR TITANIUM MAY BE ADDED TO THE PREPOLYMER.
Inventors
- 👤 E Burns
- 👤 P Peninsula
- 👤 R Jones
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 23:02
CPC Classifications
C; C08; C08G; C08G73/00; C08G73/06; C08G73/10; C08G73/1003; C08G73/1007; C08G73/1021; C08G85/00
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) | 1976-12-24 | 1977-06-25 | 1977-12-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-12-24 | 1981-06-25 | 1981-12-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-12-24 | 1985-06-25 | 1985-12-25 | $7700.00 | Window Closed / Lapsed |