US3409599A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for improving color stability of polysulfones
Assignee: Shell USA Inc
•
Filing: 1966-07-29
•
Granted: 1968-11-05
•
Expires: 1986-07-29
Abstract
No abstract record available.
Inventors
- 👤 Ronald S Bauer
- 👤 Kenneth C Dewhirst
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 21:37
CPC Classifications
C; C08; C08G; C08G75/00; C08G75/20; C08G75/205; C08G75/22
Claims Analysis
Total Claims: 0
No claims parsed yet. Click Sync Now above to re-index claims from Google Patents.
References Cited (Backward Citations)
US2183830A
Cited
US3336273A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1971-11-05 | 1972-05-06 | 1972-11-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1975-11-05 | 1976-05-06 | 1976-11-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1979-11-05 | 1980-05-06 | 1980-11-05 | $7700.00 | Window Closed / Lapsed |