US3830733A
Expired / Lapsed
US
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Diffusion membranes of controlled permeability,apparatus and process
Assignee: Union Carbide Corp
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Filing: 1972-03-09
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Granted: 1974-08-20
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Expires: 1992-03-09
Abstract
Abstract DIFFUSION MEMBRANES OF LINEAR PARA-XYLYLENE POLYMERS HAVING CONTROLLED PERMEABILITY PROPERITIES ARE PREPARED BY CONDENSING VAPOROUS POLYMER FORMING DIRADICALS WITH VAPOUOUS NON-POLYMERIZABLE FILLER MATERIALS, AND THEN REMOVING THE CONDENSED FILLER MATERIALS FROM THE RESULTING MEMBRANES TO PROVIDE THE DESIRED DEGREE OF PERMEABILITY. THE MEMBRANES ARE USED IN APPARATUS AND PROCESS FOR THE SEPARATION OF SOLIDS, LIQUIDS, GASES AND IONS.
Inventors
- 👤 M Spivack
- 👤 D Stewart
- 👤 F Tittmann
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 18:16
CPC Classifications
C; C08; C08L; C08L65/00; C08L65/04; B; B01; B01D; B01D67/00; B01D67/0002; B01D67/0023; B01D67/003; B01D69/00; B01D69/12; B01D69/125; B01D71/00; B01D71/06; B01D71/72; C08G; C08G61/00; C08G61/02; C08G61/025; B01D2325/00; B01D2325/20; C08G2261/00; C08G2261/30; C08G2261/34; C08G2261/342; C08G2261/3424
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) | 1977-08-19 | 1978-02-18 | 1978-08-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-08-19 | 1982-02-18 | 1982-08-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-08-19 | 1986-02-18 | 1986-08-20 | $7700.00 | Window Closed / Lapsed |