US3772418A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Molding process for imidazopyrrolone polymers
Assignee: National Aeronautics and Space Administration
•
Filing: 1971-10-29
•
Granted: 1973-11-13
•
Expires: 1991-10-29
Abstract
Abstract A PROCESS FOR PRODUCING SHAPED ARTICLES OF IMIDAZOPYRROLONE POLYMERS COMPRISING MOLDING IMIDAZOPYRROLONE POLYMER MOLDING POWDER UNDER PRESSURE AND AT A TEMPERATURE GREATER THAN 475*C. MODERATE PRESSURES MAY BE EMPLOYED. PREFERABLY, PRIOR TO MOLDING, A PREFORM IS PREPARED BY ISOSTATIC COMPRESSION. THE PREFORM MAY BE MOLDED AT A RELATIVELY LOW INITIAL PRESSURE AND TEMPERATURE; AS THE TEMPERATURE IS INCREASED TO A VALUE GREATER THAN 475* C., THE PRESSURE IS ALSO INCREASED.
Inventors
- 👤 C Johnson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 10:02
CPC Classifications
C; C08; C08G; C08G73/00; C08G73/06; C08G73/20; B; B29; B29C; B29C43/00; B29C43/003; B29K; B29K2105/00; B29K2105/25; B29K2105/251
Claims Analysis
Total Claims: 0
No claims parsed yet. Click Sync Now above to re-index claims from Google Patents.
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) | 1976-11-12 | 1977-05-14 | 1977-11-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-11-12 | 1981-05-14 | 1981-11-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-11-12 | 1985-05-14 | 1985-11-13 | $7700.00 | Window Closed / Lapsed |