US4906377A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Fluorocarbon membranes and process for making fluorocarbon membranes
Assignee: Entegris Inc
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Filing: 1989-05-03
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Granted: 1990-03-06
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Expires: 2009-05-03
Abstract
Abstract Microporous poly (tetrafluoroethylene-co-perfluoro (alkyl vinyl ether)) (PFA) or poly(tetrafluoroethylene-co-hexafluoropropylene) (FEP) membrane or hollow fibers are formed from a melt blend of 10 to 35 weight percent of PFA or FEP and a chlorotrifluoroethylene oligomer solvent. The melt blend is shaped and cooled to effect phase separation of the PFA or FEP from the blend. The solvent is removed from the PFA or FEP by extraction and the porous PFA or FEP is dried under restraint to prevent shrinkage.
Inventors
- 👤 Larry Y. Yen
- 👤 George Lopatin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 14:57
CPC Classifications
D; D01; D01D; D01D5/00; D01D5/24; B; B01; B01D; B01D67/00; B01D67/0002; B01D67/0023; B01D67/003; B01D67/0081; B01D67/0083; B01D67/0095; B01D71/00; B01D71/06; B01D71/30; B01D71/32; B01D71/36; C; C08; C08J; C08J9/00; C08J9/28; B01D2323/00; B01D2323/08; B01D2323/081; C08J2327/00; C08J2327/02; C08J2327/12
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
45 words
A permeable microporous fluorocarbon membrane comprising a fluorocarbon polymer selected from the group consisting of poly(tetrafluoroethylene-co-perfluoro(alkyl vinyl ether)) and poly(tetrafluoroethylene-co-hexafluoropropylene) having a mean pore size between 0.05 and 5 microns as defined by a mean isopropyl alcohol bubble point pressure between 1 and 150 psi.
Claim 2
Dependent Claim
45 words
A permeable microporous fluorocarbon membrane comprising a fluorocarbon polymer selected from the group consisting of poly(tetrafluoroethylene-co-perfluoro(alkyl vinyl ether)) and poly(tetrafluoroethylene-co-hexafluoropropylene) having a mean pore size between 0.05 and 5 microns as defined by a mean isopropyl alcohol bubble point pressure between 1 and 150 psi.
Claim 3
Dependent Claim
25 words
A microporous polymeric fluorocarbon membrane comprising a fluorocarbon polymer selected from the group consisting of poly(tetrafluoroethylene-co-perfluoro(alkyl vinylether)) and poly(tetrafluoroethylene-co-hexafluoropropylene)having a porosity between 40 and 90%.
Claim 4
Dependent Claim
25 words
A microporous polymeric fluorocarbon membrane comprising a fluorocarbon polymer selected from the group consisting of poly(tetrafluoroethylene-co-perfluoro(alkyl vinylether)) and poly(tetrafluoroethylene-co-hexafluoropropylene)having a porosity between 40 and 90%.
Claim 5
Dependent Claim
17 words
The membrane of any one of claims 1 or 2 wherein said polymer is poly(tetrafluoroethylene-co-perfluoro(alkyl vinyl ether)).
Claim 6
Dependent Claim
15 words
The membrane of any one of claims 1 or 2 wherein said lymer is poly(tetrafluoroethylene-co-hexafluoropropylene).
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) | 1993-03-05 | 1993-09-04 | 1994-03-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-03-05 | 1997-09-04 | 1998-03-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-03-05 | 2001-09-04 | 2002-03-06 | $7700.00 | Window Closed / Lapsed |