US4935139A
Expired / Lapsed
US
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Composite membranes
Assignee: Societe des Ceramiques Techniques SA
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Filing: 1989-05-22
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Granted: 1990-06-19
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Expires: 2009-05-22
Abstract
Abstract A composite membrane comprises a porous metal support and at least one porous inorganic film of sintered non-metallic particles carried by the support and overlying a surface thereof. The film is in longitudinal compression at ambient temperature, such that any cracks tend not to propagate. The composite membranes are mechanically robust and chemically inert and useful as filters e.g. in the food industry. They may be made by applying a sol or suspension of particles to form a layer on the porous metal support and heating the coated support to partly sinter the particles of the layer.
Inventors
- 👤 Alexander P. Davidson
- 👤 Michael P. Thomas
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 22:50
CPC Classifications
B; B01; B01D; B01D67/00; B01D67/0039; B01D67/0048; B01D67/0041; B01D67/00411; B01D67/0046; B01D69/00; B01D69/12; B01D71/00; B01D71/02; B01D71/05; B01D2323/00; B01D2323/06; B01D2325/00; B01D2325/02; B01D2325/0283; B01D2325/04; B01D2325/24
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
37 words
A composite membrane comprising a porous metal support and at least one porous inorganic film of sintered non-metallic particles carried by the support and overlying a surface thereof, the film being in biaxial compression at ambient temperature.
Claim 2
Dependent Claim
37 words
A composite membrane comprising a porous metal support and at least one porous inorganic film of sintered non-metallic particles carried by the support and overlying a surface thereof, the film being in biaxial compression at ambient temperature.
Claim 3
Dependent Claim
14 words
A composite membrane as claimed in claim 1, which is plastically deformable without cracking.
Claim 4
Dependent Claim
18 words
A composite membrane as claimed in claim 1, wherein the inorganic film is formed by a sol-gel technique.
Claim 5
Dependent Claim
19 words
A composite membrane as claimed in claim 1, wherein the film has a thickness of 0.05 to 10 microns.
Claim 6
Dependent Claim
25 words
A composite membrane as claimed in claim 1, wherein the support comprises sintered metal having an average pore size of from 1 to 10 microns.
Claim 7
Dependent Claim
27 words
A composite membrane as claimed in claim 1, wherein the film has an average pore size of 0.5 nm to 5 microns but less than the support.
Claim 8
Dependent Claim
13 words
A composite membrane as claimed claim 1, wherein the film is of alumina.
Claim 9
Dependent Claim
60 words
A method of making the composite membrane claimed in any claim 1, which method comprises providing a porous metal support membrane, applying to a surface thereof a sol or suspension of particles to form thereon a layer that does not substantially penetrate the pores of the support, and heating the coated support to partly sinter the particles of the layer.
Claim 10
Dependent Claim
40 words
A method as claimed in claim 8, wherein oxide or hydrated oxide sol is applied to a surface of the membrane and there converted to a gel which is dried and heated to convert it to the porous inorganic film.
Claim 11
Dependent Claim
35 words
A method as claimed in claim 8, wherein there is used a suspension of 60-955 by weight of relatively larger particles, and correspondingly from 40-5% of relatively smaller particles to act as a sintering aid.
Claim 12
Dependent Claim
26 words
A method as claimed in claim 8, wherein the support is formed or profiled into a desired shape prior to application of the sol or suspension.
References Cited (Backward Citations)
US4711719A
Cited
US4762619A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-06-18 | 1993-12-18 | 1994-06-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-06-18 | 1997-12-18 | 1998-06-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-06-18 | 2001-12-18 | 2002-06-19 | $7700.00 | Window Closed / Lapsed |