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US3733335A Expired / Lapsed US ⏱️ 0.0 years remaining

Indazolone magenta couplers

Assignee: Ilford Imaging UK Ltd
•
Filing: 1971-01-06
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Granted: 1973-05-15
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Expires: 1991-01-06
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Abstract

Abstract THIS APPLICATION DESCRIBES AN INDAZOLONE MAGNETA COUPLER OF THE FORMULA: 3-(O=),Q-2,3-DIHYDRO-1H-INDAZOLE WHERE Q IS EITHER A GROUP -NH-R WHEREIN R IS AN ACYL GROUP CONTAINING A NITROGEN ATOM TO WHICH THERE IS ATTACHED EITHER DIRECTLY OR VIA A PHENYL GROUP AN ALKYL RESIDUE OF AT LEAST 10 CARBON ATOMS, TOGETHER WITH A FREE CARBOXYLIC ACID GROUP OR A GROUP WHICH CAN LIBERATE A FREE CARBOXYLIC ACID GROUP OR Q IS A GROUP -N<(T) WHEREIN T IS AN ACYL GROUP WHICH IS ATTACHED TO THE NITROGEN ATOM BY A CYCLIC IMIDE LINKAGE, THE GROUP T CONTAINING AN ALKYL RESIDUE OF AT LEAST 10 CARBON ATOMS, THE RING TO WHICH Q IS ATTACHED OPTIONALLY CONTAINING OTHER SUBSTITUENTS.

Inventors

  • 👤 B Anderson

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-27 06:10
CPC Classifications
G; G03; G03C; G03C7/00; G03C7/30; G03C7/32; G03C7/3231

Claims Analysis

Total Claims: 0
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References Cited (Backward Citations)

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USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1976-05-14 1976-11-13 1977-05-15 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1980-05-14 1980-11-13 1981-05-15 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1984-05-14 1984-11-13 1985-05-15 $7700.00 Window Closed / Lapsed

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