US5425865A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Polymer membrane
Assignee: Freudenberg Nonwovens Ltd
•
Filing: 1991-09-19
•
Granted: 1995-06-20
•
Expires: 2011-09-19
Abstract
Abstract Composite polymer membranes are disclosed comprising a first polymeric material which defines a porous matrix, and a second polymeric material which at least partially fills, and thereby blocks, the pores of the matrix, and in which preferably each of the first and second materials are crosslinked. The membrane preferably includes a layer of an ethylenically unsaturated carboxylic acid which is graft-polymerized with the first polymeric material of the porous matrix on one of its surfaces. Crosslinking has been found to improve the transport characteristics of species through the membrane, such as the barrier performance of the membrane towards species dissolved in solution.
Inventors
- 👤 Raymond W. Singleton
- 👤 John A. Cook
- 👤 Kenneth Gargan
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 01:37
CPC Classifications
B; B01; B01D; B01D67/00; B01D67/0081; B01D67/0088; B01D67/0093; B01D67/00931; B01D69/00; B01D69/14; B01D69/141; C; C08; C08J; C08J9/00; C08J9/36; C08J9/40; C08J9/42; H; H01; H01M; H01M50/00; H01M50/40; H01M50/409; H01M50/411; H01M50/414; H01M50/417; H01M50/489; H01M50/491; H01M50/494; B01D2323/00; B01D2323/30; B01D2323/34; B01D2323/345; B01D2323/38; C08J2433/00; Y; Y02; Y02E; Y02E60/00; Y02E60/10
Claims Analysis
Total Claims: 33
Claim 1
Independent Claim
42 words
A composite polymer membrane comprising a first polymeric material which defines a microporous matrix, and a second polymeric material which at least partially fills, and thereby blocks, the pores of the matrix, and wherein at least said first polymeric material is crosslinked.
Claim 2
Dependent Claim
42 words
A composite polymer membrane comprising a first polymeric material which defines a microporous matrix, and a second polymeric material which at least partially fills, and thereby blocks, the pores of the matrix, and wherein at least said first polymeric material is crosslinked.
Claim 3
Dependent Claim
40 words
A membrane as claimed in claim 1, in which said second polymeric material formed from a vinyl monomer reacts directly or indirectly with an acid or a base to form a salt which is graft-polymerized with said first polymeric material.
Claim 4
Dependent Claim
25 words
A membrane as claimed in claim 2, in which the second polymeric material comprises a polymer of an ethylenically unsaturated acid or an ester thereof.
Claim 5
Dependent Claim
37 words
A membrane as claimed in claim 2, in which the second polymeric material in the pores of the microporous matrix and the vinyl monomer on the surface of the matrix are derived from the same monomer material.
Claim 6
Dependent Claim
16 words
A membrane as claimed in claim 1, in which said first polymeric material is a polyolefin.
Claim 7
Dependent Claim
48 words
A membrane as claimed in claim 1, said microporous matrix having a structure resulting from the formation of a film from a blend of the first polymeric material and a pore forming material which defines the pores followed by removal of said pore forming material from the film.
Claim 8
Dependent Claim
23 words
A membrane as claimed in claim 1, in which the volume of the membrane occupied by said pores is at least about 10%.
Claim 9
Dependent Claim
23 words
A membrane as claimed in claim 7, in which the volume of the membrane occupied by the pores is at least about 30%.
Claim 10
Dependent Claim
39 words
A membrane as claimed in claim 1, in which the proportion of the volume of said pores within the microporous matrix of the first polymeric material which is filled by the second polymeric material is at least about 20%.
Claim 11
Dependent Claim
38 words
A membrane as claimed in claim 9, wherein the proportion of the volume of the pores within the microporous matrix of the first polymeric material which is filled by said second polymeric material is at least about 75%.
Claim 12
Dependent Claim
38 words
A membrane as claimed in claim 9, wherein the proportion of the volume of the pores within the microporous matrix of the first polymeric material which is filled by said second polymeric material is at least about 95%.
Claim 13
Dependent Claim
15 words
A membrane as claimed in claim 1, having a thickness of less than 250 μm.
Claim 14
Dependent Claim
14 words
A membrane as claimed claim 12 having a thickness of less than 200 μm.
Claim 15
Dependent Claim
14 words
A membrane as claimed claim 12 having a thickness of less than 100 μm.
Claim 16
Dependent Claim
17 words
A membrane as claimed in claim 1 wherein both said first and second polymeric materials are crosslinked.
Claim 17
Independent Claim
63 words
A method of making a composite polymer membrane, which comprises: (a) providing a microporous matrix comprising a first polymeric material impregnated with a first reagent which is capable of crosslinking said first polymeric material; (b) causing the first polymeric material and the first reagent to react to crosslink the first polymeric material; and (c) impregnating the microporous matrix with a curable second material.
Claim 18
Independent Claim
63 words
A method of making a composite polymer membrane, which comprises: (a) providing a microporous matrix comprising a first polymeric material impregnated with a first reagent which is capable of crosslinking said first polymeric material; (b) causing the first polymeric material and the first reagent to react to crosslink the first polymeric material; and (c) impregnating the microporous matrix with a curable second material.
Claim 19
Dependent Claim
57 words
A method as claimed in claim 16, wherein said impregnating of said second material into the microporous matrix as a component of a mixture with a second reagent which is capable of crosslinking said second material, said method including the step of causing the second material to react with the second reagent to crosslink said second material.
Claim 20
Dependent Claim
24 words
A method as claimed in claim 17, wherein said crosslinking of at least one of said first and second materials is initiated by irradiation.
Claim 21
Dependent Claim
13 words
A method as claimed in claim 18, wherein said irradiation comprises ultraviolet irradiation.
Claim 22
Dependent Claim
28 words
A method as claimed in claim 16, wherein said second material is impregnated in the pores of the microporous matrix of the first polymeric material in a solution.
Claim 23
Dependent Claim
27 words
A method as claimed in claim 16, including the step of forming the microporous matrix of the first polymeric material by removing a pore forming material therefrom.
Claim 24
Dependent Claim
43 words
A method as claimed in claim 16, including the step of graft copolymerizing a vinyl monomer which reacts directly or indirectly, with an acid or a base to form a salt with said first polymeric material on the surface of the microporous matrix.
Claim 25
Dependent Claim
35 words
A method as claimed in claim 22, wherein said vinyl monomer is applied to the surface of the microporous matrix in a solution, the solution including a component for inhibiting the homopolymerization of said monomer.
Claim 26
Dependent Claim
27 words
A method as claimed in claim 23, wherein said component for inhibiting the homopolymerization of said monomer is an iron (II) salt or a copper (II) salt.
Claim 27
Dependent Claim
15 words
A method as claimed in claim 24 wherein said homopolymerization inhibitor comprises iron (II) sulphate.
Claim 28
Independent Claim
57 words
A method of crosslinking a polymeric material in the form of a microporous matrix, said polymeric material comprising a polyolefin, which comprises: (a) impregnating the matrix with a solution of reagent in a solvent which is capable crosslinking said polymeric material; (b) volatilizing said solvent in which the reagent is dissolved; and (c) crosslinking said polymeric material.
Claim 29
Independent Claim
57 words
A method of crosslinking a polymeric material in the form of a microporous matrix, said polymeric material comprising a polyolefin, which comprises: (a) impregnating the matrix with a solution of reagent in a solvent which is capable crosslinking said polymeric material; (b) volatilizing said solvent in which the reagent is dissolved; and (c) crosslinking said polymeric material.
Claim 30
Dependent Claim
22 words
A method as claimed in claim 26, including initiating said crosslinking reaction by exposure of the impregnated microporous matrix to ultraviolet radiation.
Claim 31
Dependent Claim
20 words
A method as claimed in claim 26 or claim 27, in which the material of the polymer matrix is polyethylene.
Claim 32
Dependent Claim
59 words
An electrochemical device which comprises an anode, a cathode, a liquid electrolyte, and an electrode separator comprising a composite polymer membrane comprising a first polymeric material which defines a microporous matrix, and a second polymeric material which at least partially fills, and thereby blocks, the pores of said matrix, and wherein at least said first polymeric material is crosslinked.
Claim 33
Dependent Claim
59 words
An electrochemical device which comprises an anode, a cathode, a liquid electrolyte, and an electrode separator comprising a composite polymer membrane comprising a first polymeric material which defines a microporous matrix, and a second polymeric material which at least partially fills, and thereby blocks, the pores of said matrix, and wherein at least said first polymeric material is crosslinked.
References Cited (Backward Citations)
US2965697A
Cited
US3376168A
Cited
GB1039444A
Cited
US3427206A
Cited
GB1303897A
Cited
GB1372225A
Cited
GB1449814A
Cited
GB1493654A
Cited
GB1512553A
Cited
GB1538810A
Cited
JPS53106134A
Cited
USRE31824E
Cited
US4230463A
Cited
US4547411A
Cited
US4346142A
Cited
GB2098628A
Cited
US4468441A
Cited
EP0160473A2
Cited
US4613544A
Cited
WO1987006395A1
Cited
US4804598A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1998-06-19 | 1998-12-19 | 1999-06-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2002-06-19 | 2002-12-19 | 2003-06-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2006-06-19 | 2006-12-19 | 2007-06-20 | $7700.00 | Window Closed / Lapsed |