Patent US3265502A successfully refreshed from Google Patents.
US3265502A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Photographic developing compositions
Assignee: Gevert Photo Producten N V
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Filing: 1962-06-20
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Granted: 1966-08-09
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Expires: 1982-06-20
Abstract
No abstract record available.
Inventors
- 👤 Willems Jozef Frans
- 👤 George Frans Van Veclen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 02:30
CPC Classifications
G; G03; G03C; G03C5/00; G03C5/26; G03C5/29; G03C5/30
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
41 words
PHOTOGRAPHIC DEVELOPING SOLUTION COMPRISING HYDROQUINONE AND A DERIVATIVE OF P-PHENYLENE DIAMINE HAVING A POLAROGRAPHIC HALF-WAVE POTENTIAL WHICH IS AT LEAST 40 MV. MORE NEGATIVE THAN THAT OF N,N-DIETHYL-P-PHENYLENE DIAMINE AND CORRESPONDING TO A GENERAL FORMULA SELECTED FROM THE GROUP CONSISTING OF:
Claim 2
Dependent Claim
41 words
PHOTOGRAPHIC DEVELOPING SOLUTION COMPRISING HYDROQUINONE AND A DERIVATIVE OF P-PHENYLENE DIAMINE HAVING A POLAROGRAPHIC HALF-WAVE POTENTIAL WHICH IS AT LEAST 40 MV. MORE NEGATIVE THAN THAT OF N,N-DIETHYL-P-PHENYLENE DIAMINE AND CORRESPONDING TO A GENERAL FORMULA SELECTED FROM THE GROUP CONSISTING OF:
References Cited (Backward Citations)
DE969677C
Cited
US2848326A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1969-08-08 | 1970-02-07 | 1970-08-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1973-08-08 | 1974-02-07 | 1974-08-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1977-08-08 | 1978-02-07 | 1978-08-09 | $7700.00 | Window Closed / Lapsed |