Patent US4954256A successfully refreshed from Google Patents.
US4954256A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Hydrophobic membranes
Assignee: Pall Corp
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Filing: 1989-05-15
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Granted: 1990-09-04
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Expires: 2009-05-15
Abstract
Abstract A hydrophobic polymeric microporous membrane having a CWST of less than about 28 dynes/cm is obtained by forming a (co)polymer of a fluorine-containing ethylenically unsaturated monomer that is permanently chemically bonded to a microporous membrane substrate.
Inventors
- 👤 Peter J. Degen
- 👤 Isaac Rothman
- 👤 Thomas C. Gsell
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 11:59
CPC Classifications
B; B01; B01D; B01D67/00; B01D67/0081; B01D67/0093; B01D67/00931; B01D19/00; B01D19/0031; C; C08; C08J; C08J9/00; C08J9/36; C08J9/40; C08J9/405
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
55 words
A microporous polymeric membrane having pores with diameters of about 0.05 μm or greater and a CWST less than about 28 dynes/cm comprising a microporous polymeric membrane substrate and, permanently chemically bonded to all portions of the surface thereof, a superstrate fluoropolymer formed from a monomer containing an ethylenically unsaturated group and a fluoroalkyl group.
Claim 2
Dependent Claim
55 words
A microporous polymeric membrane having pores with diameters of about 0.05 μm or greater and a CWST less than about 28 dynes/cm comprising a microporous polymeric membrane substrate and, permanently chemically bonded to all portions of the surface thereof, a superstrate fluoropolymer formed from a monomer containing an ethylenically unsaturated group and a fluoroalkyl group.
Claim 3
Dependent Claim
16 words
A microporous polymeric membrane according to claim 1 in which the monomer comprises a perfluoroalkyl group.
Claim 4
Dependent Claim
24 words
A microporous polymeric membrane according to claim 2 in which the monomer is selected from the group consisting of perfluoroalkanesulfonamidoethyl acrylates and perfluoroalkanesulfonamidoethyl methacrylates.
Claim 5
Dependent Claim
31 words
A microporous polymeric membrane according to claim 1 in which the polymer from which the substrate membrane is made is selected from the group consisting of polyamides, polyolefins, and fluorine-containing polymers.
Claim 6
Dependent Claim
18 words
A microporous polymeric membrane according to claim 4 in which the substrate membrane is made from a polyamide.
Claim 7
Dependent Claim
18 words
A microporous polymeric membrane according to claim 4 in which the substrate membrane is made from poly(vinylidene fluoride).
Claim 8
Dependent Claim
32 words
A microporous polymeric membrane according to claim 1 in which the superstrate fluoropolymer is a copolymer of a non-fluorine-containing monomer and the monomer containing an ethylenically unsaturated group and a fluoroalkyl group.
Claim 9
Dependent Claim
24 words
A microporous polymeric membrane according to claim 7 in which the non-fluorine-containing monomer is an ethylenically unsaturated monomer which contains a polar functional group.
Claim 10
Dependent Claim
28 words
A microporous polymeric membrane according to claim 8 in which the ethylenically unsaturated monomer is selected from the group consisting of unsaturated acids and esters of such acids.
Claim 11
Dependent Claim
30 words
A microporous polymeric membrane according to claim 9 in which the ethylenically unsaturated monomer is selected from esters of acrylic and methacrylic acids with a C 1 -C 18 alcohol.
Claim 12
Dependent Claim
63 words
A microporous polymeric membrane having pores with diameters of about 0.05 μm or greater and a CWST less than about 28 dynes/cm comprising a microporous, fluoropolymeric membrane substrate and, permanently chemically bonded to all portions of the surface thereof, a superstrate which is a copolymer of a non-fluorine-containing ethylenically unsaturated monomer and a monomer having an ethylenically unsaturated group and a perfluoroalkyl group.
Claim 13
Dependent Claim
63 words
A microporous polymeric membrane having pores with diameters of about 0.05 μm or greater and a CWST less than about 28 dynes/cm comprising a microporous, fluoropolymeric membrane substrate and, permanently chemically bonded to all portions of the surface thereof, a superstrate which is a copolymer of a non-fluorine-containing ethylenically unsaturated monomer and a monomer having an ethylenically unsaturated group and a perfluoroalkyl group.
Claim 14
Dependent Claim
75 words
A microporous polymeric membrane having pores with diameters of about 0.05 μm or greater and a CWST less than about 28 dynes/cm comprising a microporous polymeric membrane substrate and, permanently chemically bonded to all surfaces thereof, a fluoropolymer formed from a monomer containing an ethylenically unsaturated group and a fluoroalkyl group, said membrane having an air flow resistance that does not differ significantly from the air flow resistance of the ungrafted microporous polymeric membrane substrate.
Claim 15
Dependent Claim
75 words
A microporous polymeric membrane having pores with diameters of about 0.05 μm or greater and a CWST less than about 28 dynes/cm comprising a microporous polymeric membrane substrate and, permanently chemically bonded to all surfaces thereof, a fluoropolymer formed from a monomer containing an ethylenically unsaturated group and a fluoroalkyl group, said membrane having an air flow resistance that does not differ significantly from the air flow resistance of the ungrafted microporous polymeric membrane substrate.
Claim 16
Dependent Claim
65 words
A microporous polymeric membrane having pores with diameters of about 0.05 μm or greater and a CWST less than about 28 dynes/cm comprising a microporous polymeric membrane substrate and, permanently chemically bonded to all surfaces thereof, a fluoropolymer formed from a monomer containing an ethylenically unsaturated group and a fluoroalkyl group, said microporous polymeric membrane retaining from an essentially unchanged CWST after exposure to trichlorotrifluoroethane.
Claim 17
Dependent Claim
65 words
A microporous polymeric membrane having pores with diameters of about 0.05 μm or greater and a CWST less than about 28 dynes/cm comprising a microporous polymeric membrane substrate and, permanently chemically bonded to all surfaces thereof, a fluoropolymer formed from a monomer containing an ethylenically unsaturated group and a fluoroalkyl group, said microporous polymeric membrane retaining from an essentially unchanged CWST after exposure to trichlorotrifluoroethane.
Claim 18
Dependent Claim
22 words
The membrane of claim 1 wherein the monomer is selected from the group consisting of perfluoroalkyl acrylates, perfluoroalkyl methacrylates, and polyfluoroalkyl acrylamides.
Claim 19
Dependent Claim
24 words
The membrane of claim 14 wherein the monomer contains a perfluoroalkyl group having a carbon chain from about 4 to about 13 atoms long.
Claim 20
Dependent Claim
13 words
The membrane of claim 14 wherein the perfluoroalkyl acrylate is a fluoroalkanesulfonamidoethyl acrylate.
Claim 21
Dependent Claim
14 words
The membrane of claim 16 wherein the fluoroalkanesulfonamido ethyl acrylate is 2-(N-ethylperfluorooctanesulfonamido) ethyl acrylate.
Claim 22
Dependent Claim
13 words
The membrane of claim 14 wherein the perfluoroalkyl methacrylate is a fluoroalkanesulfonamidoethyl methacrylate.
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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) | 1993-09-03 | 1994-03-05 | 1994-09-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-09-03 | 1998-03-05 | 1998-09-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-09-03 | 2002-03-05 | 2002-09-04 | $7700.00 | Window Closed / Lapsed |