US5629186A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Porous matrix and method of its production
Assignee: ECESIS LLC
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Filing: 1994-04-28
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Granted: 1997-05-13
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Expires: 2014-04-28
Abstract
Abstract Low density fused fibrous ceramic composites are prepared from amorphous silica and/or alumina fibers with 2 to 12% boron nitride by weight of fibers, used as a fluxing agent to reduce the melting temperature of the fibers and allow the fibers to fuse at their intersections creating a three dimensional rigid matrix. The matrix is useful as a cell-culture substrate, as an implant material, and for chromatographic separation of blood cells.
Inventors
- 👤 Robert D. Yasukawa
- 👤 Loretta J. Cordrey
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 22:18
CPC Classifications
A; A61; A61L; A61L27/00; A61L27/50; A61L27/56; A61L27/02; A61L27/10; A61L27/105; C; C12; C12N; C12N5/00; C12N5/0068; A61F; A61F2310/00; A61F2310/00005; A61F2310/00179; A61F2310/00185; A61F2310/00203; C12N2533/00; C12N2533/10; C12N2533/14; Y; Y10; Y10S; Y10S435/00; Y10S435/814; Y10S435/815; Y10S530/00; Y10S530/81; Y10S530/811; Y10T; Y10T428/00; Y10T428/25; Y10T428/252
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
57 words
A porous matrix composed of fused fibers of silica, alumina, or silica and alumina and characterized by: (a) a rigid, three-dimensionally continuous network of open, intercommunicating voids formed randomly in all directions, (b) a density of between about 3.5 and 5.5 pounds/ft3; and (c) a volume occupied by the matrix fibers of between about 2-10 volume percent.
Claim 2
Dependent Claim
57 words
A porous matrix composed of fused fibers of silica, alumina, or silica and alumina and characterized by: (a) a rigid, three-dimensionally continuous network of open, intercommunicating voids formed randomly in all directions, (b) a density of between about 3.5 and 5.5 pounds/ft3; and (c) a volume occupied by the matrix fibers of between about 2-10 volume percent.
Claim 3
Dependent Claim
29 words
The matrix of claim 1, wherein the matrix is formed of silica fibers having fiber diameters between about 0.5 to 20 μm, and fiber lengths between about 1-10 mm.
Claim 4
Dependent Claim
29 words
The matrix of claim 1, wherein the matrix is formed of alumina fibers having fiber diameters between about 1 to 20 μm, and fiber lengths between about 1-10 mm.
Claim 5
Dependent Claim
31 words
The matrix of claim 1, wherein the matrix is formed of silica and alumina fibers, and the alumina fibers constitute between about 5-95 percent of the total weight of the fibers.
Claim 6
Dependent Claim
17 words
The matrix of claim 1, which further includes between about 1-5 percent by weight silicon carbide particles.
Claim 7
Dependent Claim
51 words
The matrix of claim 1, which is prepared by heating a fiber block composed of unfused fibers and having a density between about 3.3 and 5.3 pounds/cubic feet, in the presence of boron nitride to a temperature of at least about 2200° F. for a period sufficient to cause fiber fusion.
Claim 8
Dependent Claim
34 words
The matrix of claim 1 having, in one matrix dimension, a gradient of fiber diameters progressing between a selected fiber size 1-3 μm in diameter to a selected fiber size 5-20 μm in diameter.
Claim 9
Dependent Claim
31 words
The matrix of claim 1 having, in one matrix dimension, a matrix gradient progressing between a selected density 3.5-5.0 pounds/ft 3 to a selected density 5.5 to 12 pounds/ft 3 .
Claim 10
Dependent Claim
41 words
The matrix of claim 1, for use as a support for cells in a culture medium, which further includes a lattice of internal channels formed in the lattice through which liquid medium can be supplied to internal regions of the matrix.
Claim 11
Dependent Claim
39 words
The matrix of claim 1, for use as a support for cells in a culture medium, wherein the matrix is composed of a series of porous-matrix plates separated by voids through which medium can be supplied to plate surfaces.
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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) | 2000-05-12 | 2000-11-11 | 2001-05-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2004-05-12 | 2004-11-11 | 2005-05-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2008-05-12 | 2008-11-11 | 2009-05-13 | $7700.00 | Window Closed / Lapsed |