US5209850A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Hydrophilic membranes
Assignee: W.L. Gore and Associates Inc
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Filing: 1992-06-19
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Granted: 1993-05-11
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Expires: 2012-06-19
Abstract
Abstract Normally hydrophobic fluoropolymer porous membranes having continuous pores are rendered hydrophilic by coating the pore interior with a mixture of at least one fluoroaliphatic surfactant and at least one hydrophilic but substantially water-insoluble polyurethane.
Inventors
- 👤 Dilip R. Abayasekara
- 👤 Robert L. Henn
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 17:35
CPC Classifications
B; B01; B01D; B01D67/00; B01D67/0081; B01D67/0088; C; C08; C08J; C08J9/00; C08J9/36; C08J9/40; C08J9/42; C08J2327/00; C08J2327/02; C08J2327/12; C08J2475/00; Y; Y10; Y10S; Y10S264/00; Y10S264/48; Y10S264/62
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
39 words
A water-permeable hydrophilic membrane comprising a porous fluoropolymeric membrane having continuous pores from one side to the other, in which the membrane interior is coated with a mixture of a fluoroaliphatic surfactant and a hydrophilic, substantially water insoluble polyurethane.
Claim 2
Dependent Claim
39 words
A water-permeable hydrophilic membrane comprising a porous fluoropolymeric membrane having continuous pores from one side to the other, in which the membrane interior is coated with a mixture of a fluoroaliphatic surfactant and a hydrophilic, substantially water insoluble polyurethane.
Claim 3
Dependent Claim
15 words
The hydrophilic membrane of claim 1 wherein the membrane is liquid water-resistant but water vapor-permeable.
Claim 4
Dependent Claim
13 words
The hydrophilic membrane of claim 2 wherein the membrane is expanded porous polytetrafluoroethylene.
Claim 5
Dependent Claim
61 words
The hydrophilic membrane of claim 1, 2 or 3 wherein the fluoroaliphalic surfactant has an end group of the formula H 3 C(CF 2 ) m wherein m is an integer of 3 through 8, imparts a surface tension to water of less than 30 dynes per cm, and is an alcohol, an ester, an organic acid or an organic salt.
Claim 6
Dependent Claim
32 words
The hydrophilic membrane of claim 1, 2 or 3 wherein the hydrophilic polyurethane is the reaction product of a diisocyanate, a poly(oxyalkylene) glycol having predominately oxyethylene groups, and optionally a chain extender.
Claim 7
Dependent Claim
29 words
The hydrophilic membrane of claim 4 wherein the hydrophilic polyurethane is the reaction product of a diisocyanate, a poly(oxyalkylene) glycol having predominately oxyethylene groups, and optionally a chain extender.
Claim 8
Dependent Claim
48 words
Process for preparing a hydrophilic membrane which comprises subjecting a hydrophilic fluoropolymeric membrane having continuous pores from one side to the other to a solution of a fluoroaliphatic surfactant and a hydrophilic, substantially waterinsoluble polyurethane in an organic solvent and then drying the resulting membrane to remove solvent.
Claim 9
Dependent Claim
48 words
Process for preparing a hydrophilic membrane which comprises subjecting a hydrophilic fluoropolymeric membrane having continuous pores from one side to the other to a solution of a fluoroaliphatic surfactant and a hydrophilic, substantially waterinsoluble polyurethane in an organic solvent and then drying the resulting membrane to remove solvent.
References Cited (Backward Citations)
US5037457A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1996-05-10 | 1996-11-09 | 1997-05-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-05-10 | 2000-11-09 | 2001-05-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-05-10 | 2004-11-09 | 2005-05-11 | $7700.00 | Window Closed / Lapsed |