US3994732A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Dry silver toners
Assignee: 3M Co
•
Filing: 1975-09-08
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Granted: 1976-11-30
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Expires: 1995-09-08
Abstract
Abstract A combination of phthalazine and certain aromatic acids or anhydrides thereof serves as a toner during heat development of exposed dry silver image forming sheet materials.
Inventors
No inventors recorded.
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 14:23
CPC Classifications
G; G03; G03C; G03C1/00; G03C1/494; G03C1/498; G03C1/49836; G03C1/49845; Y; Y10; Y10S; Y10S430/00; Y10S430/166
Claims Analysis
Total Claims: 0
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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) | 1979-11-30 | 1980-05-31 | 1980-11-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-11-30 | 1984-05-31 | 1984-11-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-11-30 | 1988-05-31 | 1988-11-30 | $7700.00 | Window Closed / Lapsed |