US3597350A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Gel filtration process
Assignee: Cytiva Sweden AB
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Filing: 1968-11-12
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Granted: 1971-08-03
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Expires: 1988-11-12
Abstract
Abstract A GEL FILTRATION SEPARATING MEDIUM OF GRAINS OF REGENERATED CELLULOSE AND A METHOD OF PREPARATION ARE PROVIDED. THE GRAINS OF REGENERATED CELLULOSE CONTAIN WATER OR A HIGHLY AQUEOUS LIQUID CONTAIN 2 TO 25 GMS. OF CELLULOSE PER DECILITER OF GRAIN VOLUME, AND HAVE PORES SIZES MAINLY IN THE RANGE OF FROM 2 TO 200 MILLIMICRONS.
Inventors
- 👤 Helmut Determann
- 👤 Theodor Wieland
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 19:35
CPC Classifications
B; B01; B01J; B01J20/00; B01J20/22; B01D; B01D37/00
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1974-08-02 | 1975-02-01 | 1975-08-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-08-02 | 1979-02-01 | 1979-08-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-08-02 | 1983-02-01 | 1983-08-03 | $7700.00 | Window Closed / Lapsed |