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US3681284A
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Aromatic-heterocyclic polymers,prepolymers thereof and process for preparation thereof
Assignee: Centre National d'Études Spatiales
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Filing: 1970-11-30
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Granted: 1972-08-01
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Expires: 1990-11-30
Abstract
Abstract AN AROMATIC-HETEROCYCLIC, THERMALLY STABLE, LADDER TYPE POLYMER WHICH CONTAINS, IN ITS HIGH MOLECULAR WEIGHT MAIN CHAIN, A LINK HAVING DIBENZODIOXINE AS ONE OF ITS CONSTITUENTS. THE INVENTION ALSO RELATES TO A PROCESS OF PREPARING SAID POLYMER AND A PREPOLYMER FORMED DURING SAID PROCESS.
Inventors
- 👤 Friedrich Grundschober
- 👤 John Harry Arendt
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 15:02
CPC Classifications
C; C08; C08G; C08G73/00; C08G73/06; C08G73/20
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) | 1975-08-01 | 1976-01-31 | 1976-08-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-08-01 | 1980-01-31 | 1980-08-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-08-01 | 1984-01-31 | 1984-08-01 | $7700.00 | Window Closed / Lapsed |