Patent US4872888A successfully refreshed from Google Patents.
US4872888A
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Microporous membrane filter and method of producing same
Assignee: Karlsruher Institut für Technologie
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Filing: 1988-02-11
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Granted: 1989-10-10
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Expires: 2008-02-11
Abstract
Abstract A process for producing a filter including a microporous membrane and a supporting structure connected thereto, including producing a mold for the membrane and the supporting structure, filling the mold with a molding material whose solubility can be changed by high energy radiation, and forming the micropores by partial irradiation of the membrane with high energy radiation and removal of the regions having increased solubility. The filter produced according to the above method is a unitary structure with the supporting structure integrally connected to the membrane.
Inventors
- 👤 Wolfgang Ehrfeld
- 👤 Peter Hagmann
- 👤 Jurgen Mohr
- 👤 Dietrich Munchmeyer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 17:51
CPC Classifications
G; G03; G03F; G03F7/00; G03F7/004; G03F7/039; B; B01; B01D; B01D67/00; B01D67/0039; B01D67/0053; B01D67/0058; B01D69/00; B01D69/10; G03F7/0015; Y; Y10; Y10S; Y10S264/00; Y10S264/48; Y10S55/00; Y10S55/42
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
76 words
A microporous membrane filter comprising: an integrally molded body of a material whose solubility can be changed by high energy radiation and including a first flat membrane portion and a plurality of supporting elements for said membrane portion extending from one surface of said membrane portion; and a plurality of micropores provided in selected regions of said membrane portion and formed by high energy irradiation of the membrane and removal of the regions of increased solubility.
Claim 2
Dependent Claim
76 words
A microporous membrane filter comprising: an integrally molded body of a material whose solubility can be changed by high energy radiation and including a first flat membrane portion and a plurality of supporting elements for said membrane portion extending from one surface of said membrane portion; and a plurality of micropores provided in selected regions of said membrane portion and formed by high energy irradiation of the membrane and removal of the regions of increased solubility.
Claim 3
Independent Claim
133 words
A method of producing a filter including a microporous membrane having a supporting structure integrally connected to some portions of one surface of the membrane, comprising the steps of: (a) producing a mold corresponding to the desired size and shape of said membrane and said supporting structure; (b) forming the membrane and the integrally connected supporting structure by filling the mold with a molding material whose solubility can be changed by high energy radiation, and solidify the molding material; (c) removing the formed membrane and supporting structure from the mold; and (d) forming micropores in the membrane by: irradiating with high energy radiation parts of the membrane at which corresponding portions of the one surface are not connected to the supporting structure, and subsequently removing the regions of the membrane having higher solubility.
Claim 4
Independent Claim
133 words
A method of producing a filter including a microporous membrane having a supporting structure integrally connected to some portions of one surface of the membrane, comprising the steps of: (a) producing a mold corresponding to the desired size and shape of said membrane and said supporting structure; (b) forming the membrane and the integrally connected supporting structure by filling the mold with a molding material whose solubility can be changed by high energy radiation, and solidify the molding material; (c) removing the formed membrane and supporting structure from the mold; and (d) forming micropores in the membrane by: irradiating with high energy radiation parts of the membrane at which corresponding portions of the one surface are not connected to the supporting structure, and subsequently removing the regions of the membrane having higher solubility.
Claim 5
Dependent Claim
42 words
A method as defined in claim 1, wherein: said molding material is a positive resist material; and the irradiating of parts of the membrane is effected according to a pattern which corresponds to a given distribution and cross-sectional configuration of the micropores.
Claim 6
Dependent Claim
10 words
A filter produced according to the process defined claim 1.
Claim 7
Dependent Claim
55 words
A filter according to claim 4, wherein: the supporting structure includes a plurality of supporting elements extending substantially perpendicular from one surface of the porous membrane; and the supporting elements of the supporting structure have a mutual spacing of more than 20 μm with a pore width of the microporous membrane down to 0.2 μm.
Claim 8
Dependent Claim
23 words
A filter as defined in claim 5, wherein the height of the supporting elements is a multiple of the thickness of the membrane.
Claim 9
Dependent Claim
14 words
A filter as defined in claim 6, wherein the supporting elements have different heights.
Claim 10
Dependent Claim
18 words
A filter as defined in claim 6, wherein the supporting structure has a laminar or a honeycomb configuration.
Claim 11
Dependent Claim
17 words
A filter as defined in claim 5, wherein the supporting structure have a laminar or honeycomb configuration.
References Cited (Backward Citations)
US3438504A
Cited
US3846521A
Cited
US4330406A
Cited
US3992495A
Cited
US4356215A
Cited
DE2440081A1
Cited
US4046843A
Cited
US4457817A
Cited
US4147745A
Cited
US4107049A
Cited
US4163725A
Cited
US4353799A
Cited
US4265959A
Cited
US4268662A
Cited
US4283359A
Cited
US4347139A
Cited
US4517142A
Cited
US4430278A
Cited
US4548769A
Cited
US4514345A
Cited
DE3332345A1
Cited
US4655797A
Cited
DE3546328A1
Cited
DD238467A1
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-10-09 | 1993-04-10 | 1993-10-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-10-09 | 1997-04-10 | 1997-10-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-10-09 | 2001-04-10 | 2001-10-10 | $7700.00 | Window Closed / Lapsed |