US2431251A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Anion exchange resin prepared with urea, paraformaldehyde, and aniline hydrochloride and process of removing acids from liquids therewith
Assignee: Permutit Co
•
Filing: 1944-02-02
•
Granted: 1947-11-18
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Expires: 1964-02-02
Abstract
No abstract record available.
Inventors
- 👤 Holmes Eric Leighton
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 22:05
CPC Classifications
C; C08; C08G; C08G12/00; C08G12/02; C08G12/04; B; B01; B01J; B01J41/00; B01J41/08; B01J41/12; B01J41/13
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US1536881A
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US1846853A
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US2228514A
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US2246526A
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US2246527A
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US2328901A
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US2251234A
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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) | 1950-11-17 | 1951-05-19 | 1951-11-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1954-11-17 | 1955-05-19 | 1955-11-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1958-11-17 | 1959-05-19 | 1959-11-18 | $7700.00 | Window Closed / Lapsed |