US4946592A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Membrane filter
Assignee: Societe des Ceramiques Techniques SA
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Filing: 1989-11-15
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Granted: 1990-08-07
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Expires: 2009-11-15
Abstract
Abstract The filter membrane comprises a porous structure made of a material selected from sintered ceramics, sintered metals, microporous carbon, and microporous glass, and is characterized by the fact that its entire external surface, including the inside surface of the pores in the structure, is covered with a thin and continuous film of carbon or of an oxide. In a sintered aluminum membrane, the surfaces of pores are coated with a dense and continuous thin layer of zirconia which prevents the surfaces from being degraded in service. In the figure, curve 3 shows how the throughput of a membrane without a zirconia layer falls off over time, while curve 4 shows little change in the same membrane having such a layer.
Inventors
- 👤 Stanislas Galaj
- 👤 Marie-Paule Besland
- 👤 Alain Wicker
- 👤 Jacques Gillot
- 👤 Raymond Soria
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 00:01
CPC Classifications
C; C04; C04B; C04B41/00; C04B41/80; C04B41/81; C04B41/85; C04B41/87; B; B01; B01D; B01D67/00; B01D67/0039; B01D67/0067; B01D67/0072; B01D71/00; B01D71/02; B01D71/0215; C04B41/009; C04B41/45; C04B41/50; C04B41/5025; C04B41/5042; B01D2323/00; B01D2323/08; B01D2323/081; B01D2323/082; B01D2325/00; B01D2325/04
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
237 words
A filter membrane comprising a porous structure made of a material selected from sintered ceramics and sintered metals, and formed by grains which are fixed one to another by bonded portions of their surfaces leaving pores therebetween delimited by the remaining exposed portions of the surfaces of the said grains, wherein the entire exposed portions of the surfaces of the grains including the surface inside the pores of the porous structure are covered with a thin and continuous film of an oxide selected from the group consisting of ZrO 2 , MgO, Al 2 O 3 , SiO 2 , TiO 2 , Cr 2 O 3 , MnO, Fe 2 O 3 , CoO, NiO, CuO, ZnO, Ga 2 O 3 , GeO 2 , TlO 2 , Nb 2 O 5 , MoO 3 , RuO 2 , PdO, CdO, SnO 2 , La 2 O 3 , HfO 2 , Ta 2 O 5 , WO 3 , PbO 2 , Ce 2 O 3 , and Bi 2 O 3 , alone or in combination, or in mixture with B 2 O 3 , BaO or CaO, wherein the thickness of said film lies between 2 nm and 1000 nm, wherein the average pore diameter of the surface layer of said structure lies between 0.02 microns and 15 microns, the porosity of the membrane being then substantially that of the initial porous structure.
Claim 2
Dependent Claim
237 words
A filter membrane comprising a porous structure made of a material selected from sintered ceramics and sintered metals, and formed by grains which are fixed one to another by bonded portions of their surfaces leaving pores therebetween delimited by the remaining exposed portions of the surfaces of the said grains, wherein the entire exposed portions of the surfaces of the grains including the surface inside the pores of the porous structure are covered with a thin and continuous film of an oxide selected from the group consisting of ZrO 2 , MgO, Al 2 O 3 , SiO 2 , TiO 2 , Cr 2 O 3 , MnO, Fe 2 O 3 , CoO, NiO, CuO, ZnO, Ga 2 O 3 , GeO 2 , TlO 2 , Nb 2 O 5 , MoO 3 , RuO 2 , PdO, CdO, SnO 2 , La 2 O 3 , HfO 2 , Ta 2 O 5 , WO 3 , PbO 2 , Ce 2 O 3 , and Bi 2 O 3 , alone or in combination, or in mixture with B 2 O 3 , BaO or CaO, wherein the thickness of said film lies between 2 nm and 1000 nm, wherein the average pore diameter of the surface layer of said structure lies between 0.02 microns and 15 microns, the porosity of the membrane being then substantially that of the initial porous structure.
Claim 3
Dependent Claim
35 words
A membrane according to claim 1, wherein the thickness of said film lies between 0.1% of 10% of the average diameter of the pores in the layer of said structure having the smallest diameter pores.
References Cited (Backward Citations)
US32603A
Cited
US3022187A
Cited
FR1517389A
Cited
US3751271A
Cited
US4085048A
Cited
JPS5176188A
Cited
CA1140003A
Cited
US4242159A
Cited
US4278544A
Cited
US4473476A
Cited
EP0040282A1
Cited
US4619767A
Cited
GB2097777A
Cited
US4698157A
Cited
EP0135069A2
Cited
WO1985000758A1
Cited
US4711719A
Cited
US4562021A
Cited
EP0136937A1
Cited
US4724078A
Cited
EP0141388A2
Cited
USRE32603E
Cited
US4689150A
Cited
US4719058A
Cited
US4865742A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-08-06 | 1994-02-05 | 1994-08-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-08-06 | 1998-02-05 | 1998-08-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-08-06 | 2002-02-05 | 2002-08-07 | $7700.00 | Window Closed / Lapsed |