US2197809A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Photographic process and emulsion utilizing cation-active surface active agents
Assignee: DuPont Film Manufacturing Corp
•
Filing: 1938-01-03
•
Granted: 1940-04-23
•
Expires: 1958-01-03
Abstract
No abstract record available.
Inventors
- 👤 David M Mcqueen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 18:04
CPC Classifications
G; G03; G03C; G03C5/00; G03C5/26; G03C5/29; G03C5/305; G03C5/3053; G03C1/00; G03C1/005; G03C1/06; G03C1/38
Claims Analysis
Total Claims: 0
No claims parsed yet. Click Sync Now above to re-index claims from Google Patents.
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) | 1943-04-23 | 1943-10-23 | 1944-04-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1947-04-23 | 1947-10-23 | 1948-04-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1951-04-23 | 1951-10-23 | 1952-04-23 | $7700.00 | Window Closed / Lapsed |