Patent US2575440A successfully refreshed from Google Patents.
US2575440A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Crotonate esters of glyceryl polyethers of dihydric phenols
Assignee: Shell Development Co
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Filing: 1948-11-16
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Granted: 1951-11-20
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Expires: 1968-11-16
Abstract
No abstract record available.
Inventors
- 👤 Theodore F Bradley
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 10:11
CPC Classifications
C; C08; C08G; C08G59/00; C08G59/14; C08G59/1433; C08G59/1438; C08G59/1455; C08G59/1461
Claims Analysis
Total Claims: 1
Claim 1
Independent Claim
10 words
A POLYMER OF A CROTONIC ACID ESTER OF THE FORMULA
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) | 1954-11-19 | 1955-05-21 | 1955-11-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1958-11-19 | 1959-05-21 | 1959-11-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1962-11-19 | 1963-05-21 | 1963-11-20 | $7700.00 | Window Closed / Lapsed |