US2947760A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Chroman derivatives
Assignee: Shell USA Inc
•
Filing: 1957-05-16
•
Granted: 1960-08-02
•
Expires: 1977-05-16
Abstract
No abstract record available.
Inventors
- 👤 Bruin Pieter
- 👤 Klootwijk Arie
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 10:28
CPC Classifications
C; C07; C07D; C07D311/00; C07D311/02; C07D311/04; C07D311/58; C07D311/60
Claims Analysis
Total Claims: 1
Claim 1
Independent Claim
10 words
AS A NEW COMPOSITION OF MATTER, A COMPOUND THE FORMULA
References Cited (Backward Citations)
US2418458A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1963-08-02 | 1964-02-01 | 1964-08-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1967-08-02 | 1968-02-01 | 1968-08-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1971-08-02 | 1972-02-01 | 1972-08-02 | $7700.00 | Window Closed / Lapsed |