Patent US3580891A successfully refreshed from Google Patents.
US3580891A
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US
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Water-insoluble,cross-linked polymeric reaction product of ethylene diamine and nitrilotriacetic acid or derivative
Assignee: Seekay Chemical Co
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Filing: 1968-04-16
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Granted: 1971-05-25
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Expires: 1988-04-16
Abstract
Abstract A SOLUTE IS REMOVED FROM AN AQUEOUS SOLUTION BY CONTACTING SAID SOLUTION WITH A CROSS LINKED POLYMER CONTAINING RECURRING NITROGEN ATOMS INTERCONNECTED AT EACH VALENCE BY RADICALS OF THE FORMULA -(CH2)A-CO-NH-X-NH-CO-(CH2)
Inventors
- 👤 Norman B Rainer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 23:09
CPC Classifications
B; B01; B01J; B01J20/00; B01J20/22; B01J45/00; C; C02; C02F; C02F5/00; C02F5/08; C02F5/10; C02F5/12; C08; C08G; C08G69/00; C08G69/02; C08G69/26
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) | 1974-05-24 | 1974-11-23 | 1975-05-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-05-24 | 1978-11-23 | 1979-05-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-05-24 | 1982-11-23 | 1983-05-25 | $7700.00 | Window Closed / Lapsed |