US3662046A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of making reverse osmosis membranes for desalination of water
Assignee: United States Department of the Interior
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Filing: 1970-06-03
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Granted: 1972-05-09
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Expires: 1990-06-03
Abstract
Abstract REVERSE OSMOSIS MEMBRANES ARE PRODUCED BY SPRAYING A FILM-FORMING SOLUTION ONTO A SUBSTRATE IN A ZONE INTO WHICH IS INJECTED, THROUGHOUT SPRAYING, AN INERT GAS SATURATED WITH POLYMER SOLVENT VAPOR. SOLVENT IS THEN EVAPORATED FROM THE FILM BY REDUCING THE DEGREE OF SOLVENT SATURATION OF THE INERT GAS IN THE EVAPORATION ZONE BY INTRODUCING GAS THAT IS LESS THAN SATURATED WITH SOLVENT, BY LOWERING THE ATMOSPHERIC PRESSURE IN THE ZONE OR BY HEATING THE ATMOSPHERE. THE FILM IS THEN CURED IN THE PRIOR ART MANNER BY QUENCHING AND ANNEALING. ELECTROSTATIC SPRAYING IS MOST EFFECTIVE.
Inventors
- 👤 Jung Woo Woo
- 👤 Paul F Waters
- 👤 Raymond H Horowitz
- 👤 Albert F Hadermann
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 10:55
CPC Classifications
B; B01; B01D; B01D69/00; B01D69/06; B29; B29C; B29C41/00; B29C41/24; B29C41/28; B29C41/34; B29C41/36; B29C41/365
Claims Analysis
Total Claims: 0
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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) | 1975-05-09 | 1975-11-08 | 1976-05-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-05-09 | 1979-11-08 | 1980-05-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-05-09 | 1983-11-08 | 1984-05-09 | $7700.00 | Window Closed / Lapsed |