US2515581A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Regeneration of ion exchange materials
Assignee: Wyeth Holdings LLC
•
Filing: 1947-08-07
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Granted: 1950-07-18
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Expires: 1967-08-07
Abstract
No abstract record available.
Inventors
- 👤 Andren J Appelquest
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 19:26
CPC Classifications
B; B01; B01J; B01J49/00; B01J49/05; B01J49/09
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
44 words
A PROCESS OF ACTIVATING ANION AND CATION EXCHANGE RESINS IN THE PRESENCE OF EACH OTHER WHICH COMPRISES TREATING THE COMBINATION OF RESINS FIRST WITH ACID AND THEN WITH A REAGENT SELECTED FROM THE GROUP CONSISTING OF (1) HEXAMETHYLENETETRAMINE AND (2) AMMONIA FOLLOWED BY FORMALDEHYDE.
Claim 2
Dependent Claim
44 words
A PROCESS OF ACTIVATING ANION AND CATION EXCHANGE RESINS IN THE PRESENCE OF EACH OTHER WHICH COMPRISES TREATING THE COMBINATION OF RESINS FIRST WITH ACID AND THEN WITH A REAGENT SELECTED FROM THE GROUP CONSISTING OF (1) HEXAMETHYLENETETRAMINE AND (2) AMMONIA FOLLOWED BY FORMALDEHYDE.
References Cited (Backward Citations)
US2275210A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1953-07-17 | 1954-01-16 | 1954-07-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1957-07-17 | 1958-01-16 | 1958-07-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1961-07-17 | 1962-01-16 | 1962-07-18 | $7700.00 | Window Closed / Lapsed |