Patent US2228752A successfully refreshed from Google Patents.
US2228752A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for the separation of divinylacetylene and ethinylbutadiene and the preparation of the latter in purified form
Assignee: EIDP Inc
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Filing: 1939-07-04
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Granted: 1941-01-14
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Expires: 1959-07-04
Abstract
No abstract record available.
Inventors
- 👤 Carter Albert Smith
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 16:18
CPC Classifications
C; C07; C07C; C07C7/00; C07C7/148; C07C7/14833; C07C7/1485
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) | 1944-01-14 | 1944-07-15 | 1945-01-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1948-01-14 | 1948-07-15 | 1949-01-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1952-01-14 | 1952-07-15 | 1953-01-14 | $7700.00 | Window Closed / Lapsed |