US3714010A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Preparation of anion exchange membranes from cellulosic sheets
Assignee: United States Department of the Interior
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Filing: 1972-01-06
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Granted: 1973-01-30
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Expires: 1992-01-06
Abstract
Abstract ANION EXCHANGE MEMBRANES CAN BE PREPARED FROM CELLULOSE SHEET MATERIALS SUCH AS CELLOPHASE, PARCHMENT PAPER, OR KRAFT PAPER BY IMPREGNATING THE SHEET WITH POLYETHYLENEIMINE. THE MEMBRANE IS CROSS-LINKED AT A TEMPERATURE FROM 10 TO 50*C., WITH A RREAGENT SELECTED FROM THE GROUP OF MONALDEHYDES, DIALDEHYDES, REACTIVE METHOLYOL COMPOUNDS AND MIXTURES THEREOF. THE MEMBRANE IS THEN QUATERNIZED. IT IS PARTICULARLY SUITED FOR USE IN THE ELECTRODIALYTIC PURIFICATION OF SALINE WATER.
Inventors
- 👤 A Sueszer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 07:49
CPC Classifications
B; B01; B01J; B01J41/00; B01J41/08; B01J41/12; B01J41/16; C; C08; C08J; C08J5/00; C08J5/20; C08J5/22; C08J5/2206; C08J5/2212; C08J2301/00
Claims Analysis
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References Cited (Backward Citations)
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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) | 1976-01-30 | 1976-07-31 | 1977-01-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-01-30 | 1980-07-31 | 1981-01-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-01-30 | 1984-07-31 | 1985-01-30 | $7700.00 | Window Closed / Lapsed |