US3822202A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Heat treatment of membranes of selected polyimides,polyesters and polyamides
Assignee: EIDP Inc
•
Filing: 1972-11-02
•
Granted: 1974-07-02
•
Expires: 1992-11-02
Abstract
Abstract CERTAIN POLYMERIC MEMBRANES ARE HEATED AT ELEVATED TEMPERATURES TO IMPROVE THEIR GAS SEPARATION ABILITIES.
Inventors
- 👤 H Hoehn
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 17:29
CPC Classifications
B; B01; B01D; B01D67/00; B01D67/0081; B01D67/0083; B01D71/00; B01D71/06; B01D71/48; B01D71/56; B01D71/58; B01D71/62; B01D71/64; C; C08; C08G; C08G63/00; C08G63/68; C08G63/682; C08G63/6824; C08G63/6826; C08G69/00; C08G69/02; C08G69/26; C08G69/32; C08G73/00; C08G73/06; C08G73/10; C08G73/1067
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) | 1977-07-01 | 1977-12-31 | 1978-07-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-07-01 | 1981-12-31 | 1982-07-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-07-01 | 1985-12-31 | 1986-07-02 | $7700.00 | Window Closed / Lapsed |