Patent US2638463A successfully refreshed from Google Patents.
US2638463A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Polymers from pyrrolidone
Assignee: Arnold Hoffman & Co Inc
•
Filing: 1951-12-07
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Granted: 1953-05-12
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Expires: 1971-12-07
Abstract
No abstract record available.
Inventors
- 👤 Jr William O Ney
- 👤 William R Nummy
- 👤 Carl E Barnes
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 22:47
CPC Classifications
C; C08; C08G; C08G69/00; C08G69/02; C08G69/08; C08G69/14; C08G69/24
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
1 words
POLYPYRROLIDONE.
Claim 2
Dependent Claim
1 words
POLYPYRROLIDONE.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1956-05-11 | 1956-11-10 | 1957-05-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1960-05-11 | 1960-11-10 | 1961-05-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1964-05-11 | 1964-11-10 | 1965-05-12 | $7700.00 | Window Closed / Lapsed |