Patent US622124A successfully refreshed from Google Patents.
US4874516A
Expired / Lapsed
US
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A ceramic filter for semi-ultrafiltration
Assignee: NGK Insulators Ltd
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Filing: 1985-12-23
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Granted: 1989-10-17
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Expires: 2005-12-23
Abstract
Abstract This invention relates to a filter which includes a substrate of a ceramic porous material of a high strength, which serves as a support, covered with a microporous membrane of a polymer, typically a fluorocarbon polymer, partly permeating the surface layer of the substrate and acting as a filter for fine particles. The filter exhibits excellent corrosion-resistance, durableness and heat-resistance and is used for semi-ultrafiltration such as filtration for sterilization, purification of crystals and the like.
Inventors
- 👤 Kuniharu Kondo
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 08:22
CPC Classifications
B; B01; B01D; B01D69/00; B01D69/10; B01D69/108; B01D2325/00; B01D2325/02; B01D2325/0283
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
118 words
A filter comprising: a substrate consisting essentially of a ceramic porous material, said ceramic porous material having an average pore diameter of between about 0.5 microns and about 10 microns and having a pore volume of 30-50% based on an apparent volume of the substrate; and a microporous membrane consisting essentially of a high polymeric resin having an average pore diameter of about 0.1 microns to about 1 micron, said membrane covering at least one surface of said ceramic porous material to a thickness of about 30-500 microns above said at least one surface and said membrane partly permeating into said ceramic porous material, thereby forming an intermediary layer between said ceramic porous material and said microporous membrane.
Claim 2
Dependent Claim
118 words
A filter comprising: a substrate consisting essentially of a ceramic porous material, said ceramic porous material having an average pore diameter of between about 0.5 microns and about 10 microns and having a pore volume of 30-50% based on an apparent volume of the substrate; and a microporous membrane consisting essentially of a high polymeric resin having an average pore diameter of about 0.1 microns to about 1 micron, said membrane covering at least one surface of said ceramic porous material to a thickness of about 30-500 microns above said at least one surface and said membrane partly permeating into said ceramic porous material, thereby forming an intermediary layer between said ceramic porous material and said microporous membrane.
Claim 3
Dependent Claim
28 words
The filter of claim 1, wherein said high polymeric resin comprises at least one resin selected from the group consisting of fluorocarbon resin, polypropylene resin and polyvinylchloride resin.
Claim 4
Dependent Claim
14 words
The filter of claim 1, wherein said ceramic porous material comprises a sintered material.
Claim 5
Dependent Claim
14 words
The filter of claim 1, wherein said ceramic porous material comprises a foamed material.
Claim 6
Dependent Claim
19 words
The filter of claim 1, wherein the average pore diameter of the microporous membrane does not exceed 0.5 microns.
Claim 7
Dependent Claim
29 words
The filter of claim 1, wherein said substrate comprises a cylinder having an inner surface and an outer surface, and said inner surface is covered by said microporous membrane.
Claim 8
Dependent Claim
29 words
The filter of claim 1, wherein said substrate comprises a cylinder having an inner surface and an outer surface, and said outer surface is covered by said microporous membrane.
Claim 9
Dependent Claim
32 words
The filter of claim 1, wherein said substrate comprises a cylinder having an inner surface and outer surface, and each of said inner and outer surfaces are covered with said microporous membrane.
Claim 10
Dependent Claim
12 words
The filter of claim 1, wherein said ceramic porous material comprises alumina.
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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) | 1992-10-16 | 1993-04-17 | 1993-10-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-10-16 | 1997-04-17 | 1997-10-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-10-16 | 2001-04-17 | 2001-10-17 | $7700.00 | Window Closed / Lapsed |