Patent US2640822A successfully refreshed from Google Patents.
US2640822A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Acxljlted
Assignee: —
•
Filing: —
•
Granted: 1953-06-02
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Expires: 1970-06-02
Abstract
No abstract record available.
Inventors
No inventors recorded.
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 18:02
CPC Classifications
C; C08; C08G; C08G73/00; C08G73/02; C08G73/028
Claims Analysis
Total Claims: 1
Claim 1
Independent Claim
21 words
AS A NEW COMPOSITION OF MATTER, AN N-ACYLSUBSTITUTED POLYMERIC OXYGEN-CONTAINING POLYAMINO MATERIAL, WHICH POLYMERIC OXYGEN-CONTAINING POLYAMINO MATERIAL IS PRODUCED BY CONDENS-
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1956-06-01 | 1956-12-01 | 1957-06-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1960-06-01 | 1960-12-01 | 1961-06-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1964-06-01 | 1964-12-01 | 1965-06-02 | $7700.00 | Window Closed / Lapsed |