US3767737A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for production casting of ultrathin polymer membranes
Assignee: General Electric Co
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Filing: 1971-09-07
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Granted: 1973-10-23
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Expires: 1991-09-07
Abstract
Abstract ULTRATHIN POLYMER MEMBRANES, WHICH ARE NON-POROUS BUT PERMEABLE, ARE PROVIDED BY CONTINUOUSLY TRANSFERRING A POLYMER-CONTAINING CASTING SOLUTION UPWARDLY THROUGH A FLOATING SUPPORT LIQUID AND REMOVING THE SOLVENT FROM THE SOLUTION TO FORM THE MEMBRANES ON THE SURFACE OF THE SUPPORT LIQUID.
Inventors
- 👤 J Lundstrom
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 01:30
CPC Classifications
B; B01; B01D; B01D71/00; B01D71/06; B01D71/76; B01D71/80; B01D69/00; B01D69/12; B01D69/122; B29; B29C; B29C48/00; B29C48/03; B29C48/07; B29C48/08; B29C48/25; B29C48/88; B29C48/91; B29C48/911; B29C48/9135; B05; B05D; B05D1/00; B05D1/18; B05D1/20; B05D2252/00; B05D2252/02
Claims Analysis
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References Cited (Backward Citations)
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-10-22 | 1977-04-23 | 1977-10-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-10-22 | 1981-04-23 | 1981-10-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-10-22 | 1985-04-23 | 1985-10-23 | $7700.00 | Window Closed / Lapsed |