Patent US4060488A successfully refreshed from Google Patents.
US4060488A
Expired / Lapsed
US
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Particulate membrane ultrafiltration device
Assignee: EIDP Inc
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Filing: 1975-11-20
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Granted: 1977-11-29
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Expires: 1995-11-20
Abstract
Abstract An ultrafiltration device which includes a porous support, one surface of which is coated with a membrane comprising at least two sizes of particles, one size being capable of passing through the pores and another size capable of passing into but not through the pores.
Inventors
- 👤 Fred Wayne Hoover
- 👤 Ralph K. Iler
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 19:50
CPC Classifications
B; B01; B01D; B01D67/00; B01D67/0081; B01D67/0088; B01D67/0093; B01D67/00931; B01D69/00; B01D69/14; B01D69/141; B01D69/148; B01D71/00; B01D71/02; B01D2323/00; B01D2323/08; B01D2323/081; B01D61/00; B01D61/14; B01D61/145
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
137 words
In an ultrafiltration device of the type comprising an integral porous support having pores about from 0.5 to 45 microns in their smallest cross sectional dimension and a removable and renewable particulate membrane inert to feedstock coated onto at least a portion of the surface of the support, the improvement wherein the membrane comprises a. large inorganic particles about from 0.5 to 45 microns in average cross sectional dimension and of such size as will enter but not pass through the pores of the support and b. small inorganic particles about from 0.002 to 0.5 microns in average cross sectional dimension and of such size as will pass through the pores of the support, said particles being bonded together with silica particles formed by heating the membrane with an alkaline solution of silica at about 90°-100° C.
Claim 2
Dependent Claim
137 words
In an ultrafiltration device of the type comprising an integral porous support having pores about from 0.5 to 45 microns in their smallest cross sectional dimension and a removable and renewable particulate membrane inert to feedstock coated onto at least a portion of the surface of the support, the improvement wherein the membrane comprises a. large inorganic particles about from 0.5 to 45 microns in average cross sectional dimension and of such size as will enter but not pass through the pores of the support and b. small inorganic particles about from 0.002 to 0.5 microns in average cross sectional dimension and of such size as will pass through the pores of the support, said particles being bonded together with silica particles formed by heating the membrane with an alkaline solution of silica at about 90°-100° C.
Claim 3
Dependent Claim
42 words
An ultrafiltration device of claim 1 wherein the support has 2-20 micron pores, the size range of the large particles is about from 2 to 20 microns and the size range of the small particles is about from 0.004 to 0.4 microns.
Claim 4
Dependent Claim
43 words
An ultrafiltration device of claim 1 wherein the membrane further comprises inorganic particles intermediate in size between the large and the small particles, the size range of the intermediate-sized particles being substantially nonoverlapping with the size ranges of the large and small particles.
Claim 5
Dependent Claim
23 words
An ultrafiltration device of claim 3 wherein the intermediate size particles are about from 0.1 to 5.0 microns in average cross sectional dimensions.
Claim 6
Dependent Claim
38 words
An ultrafiltration device of claim 4 wherein the size range of the large particles is 3 to 10 microns, of the small particles is 0.004 to 0.4 microns and of the intermediate particles is 0.2 to 2 microns.
Claim 7
Dependent Claim
25 words
An ultrafiltration device of claim 1 in which the inorganic particles comprise at least one of alumina, silica, zirconia, thoria, titania, stannic oxide, and carbon.
Claim 8
Dependent Claim
18 words
An ultrafiltration device of claim 6 in which the small inorganic particles consist essentially of alumina or silica.
Claim 9
Dependent Claim
17 words
An ultrafiltration device of claim 1 in which the silica-treated membrane is further treated with sodium aluminate.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-11-28 | 1981-05-30 | 1981-11-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-11-28 | 1985-05-30 | 1985-11-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-11-28 | 1989-05-30 | 1989-11-29 | $7700.00 | Window Closed / Lapsed |