US4981590A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Composite ceramic micropermeable membrane, process and apparatus for producing such membrane
Assignee: HOLLAND INDUSTRIAL CERAMICS
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Filing: 1988-11-16
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Granted: 1991-01-01
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Expires: 2008-11-16
Abstract
Abstract A microporous ceramic membrane comprising a porous support and a microporous layer firmly bound to each other, with a sharp geometric transition between the support and the microporous layer, the microporous layer being free of pin-holes. The microporous membrane has a predetermined average pore diameter and it is suitable for microfiltration. The membrane can comprise further microporous layers making it suitable for ultrafiltration and hyperfiltration. The membrane can be prepared by suspension coating of a support, whereby the support and/or the suspension are pretreated in order to lower temporarily the affinity between the support and the suspension.
Inventors
- 👤 Willem H. Van 'T Veen
- 👤 Albertus J. G. Engel
- 👤 Benedictus C. Bonekamp
- 👤 Hubertus J. Veringa
- 👤 Rinse A. Terpstra
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 05:45
CPC Classifications
B; B01; B01D; B01D67/00; B01D67/0039; B01D67/0048; B01D69/00; B01D69/04; B01D69/10; B01D69/105; B01D69/12; B01D69/1216; B05; B05C; B05C3/00; B05C3/18; B05C7/00; B05C7/04; C; C04; C04B; C04B41/00; C04B41/009; C04B41/45; C04B41/50; C04B41/5025; C04B41/5031; C04B41/52; C04B41/80; C04B41/81; C04B41/85; C04B41/87; C04B41/89; B01D2323/00; B01D2323/42
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
86 words
A two layer microporous membrane consisting of a porous ceramic support having pore sizes between 0.1 μm and 50 μm and only one microporous sintered inorganic layer, wherein the microporous layer is bonded directly to the geometric outer surface of the porous support, thereby substantially spanning the pores of the support, with a sharp transition in permeability between the microporous layer and the porous support, the microporous layer having a predetermined average pore diameter between 20 nm and 1 μm, and being essentially free of pin-holes.
Claim 2
Dependent Claim
86 words
A two layer microporous membrane consisting of a porous ceramic support having pore sizes between 0.1 μm and 50 μm and only one microporous sintered inorganic layer, wherein the microporous layer is bonded directly to the geometric outer surface of the porous support, thereby substantially spanning the pores of the support, with a sharp transition in permeability between the microporous layer and the porous support, the microporous layer having a predetermined average pore diameter between 20 nm and 1 μm, and being essentially free of pin-holes.
Claim 3
Dependent Claim
19 words
The membrane of claim 1, characterized by a thickness of the microporous layer of 10-100 μm, preferably 15-30 μm.
Claim 4
Dependent Claim
18 words
The membrane of claim 1, characterized by an average pore diameter of the microporous layer of 100-500 nm.
Claim 5
Dependent Claim
17 words
The membrane of claim 1, characterized in that the microporous layer consists essentially of a metal oxide.
Claim 6
Dependent Claim
13 words
The membrane of claim 4, characterized in that the metal oxide is alumina.
Claim 7
Dependent Claim
16 words
The membrane of claim 1, characterized in that the porous support consists essentially of alpha alumina.
References Cited (Backward Citations)
FR1531810A
Cited
FR1506402A
Cited
FR2150390A1
Cited
FR2527092A1
Cited
FR2230601A1
Cited
US4042359A
Cited
US4077885A
Cited
FR2336360A1
Cited
FR2359804A1
Cited
FR2418007A1
Cited
EP0040282A1
Cited
FR2502508A1
Cited
EP0075962A1
Cited
US4423700A
Cited
EP0092840A1
Cited
EP0144097A1
Cited
EP0136937A1
Cited
EP0184926A1
Cited
EP0188950A1
Cited
US4689150A
Cited
FR2580517A1
Cited
JPS6274409A
Cited
EP0242208A1
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-12-31 | 1994-07-02 | 1995-01-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-12-31 | 1998-07-02 | 1999-01-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-12-31 | 2002-07-02 | 2003-01-01 | $7700.00 | Window Closed / Lapsed |