US3660281A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Permeation separation membranes
Assignee: EIDP Inc
•
Filing: 1970-05-06
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Granted: 1972-05-02
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Expires: 1990-05-06
Abstract
Abstract A MEMBRANE FOR THE SELECTIVE PERMEATION SEPARATION OF AQUEOUS MIXTURES, WHICH IS A THIN FILM OR HOLLOW FILAMENT OF A LINEAR ALIPHATIC POLYAMIDE RESIN CONTAINING A HYDROLYZABLE TANNIN.
Inventors
- 👤 Frank William Tober
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 06:32
CPC Classifications
B; B01; B01D; B01D67/00; B01D67/0081; B01D67/0088; B01D71/00; B01D71/06; B01D71/56
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) | 1975-05-02 | 1975-11-01 | 1976-05-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-05-02 | 1979-11-01 | 1980-05-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-05-02 | 1983-11-01 | 1984-05-02 | $7700.00 | Window Closed / Lapsed |