Patent US3738840A successfully refreshed from Google Patents.
US3738840A
Expired / Lapsed
US
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Colour couplers
Assignee: Ilford Imaging UK Ltd
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Filing: 1970-04-14
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Granted: 1973-06-12
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Expires: 1990-04-14
Abstract
Abstract THIS APPLICATION DESCRIBES A COLOUR COUPLER SELECTED FROM THE CLASS CONSISTING OF COMPOUNDS OF THE GENERAL FORMULA: (3-(R1-X-)PHENYL)-Q-B AND OF THE GENERAL FORMULA: (2-(R1-X-)PHENYL)-Q-B WHEREIN IN THE ABOVE TWO FORMULAE B REPRESENTS A COLOUR COUPLER RESIDUE, Q IS A GROUP CONTAINING AN ALKALI SOLUBILISING RADICAL, R1 IS AN ALKYL GROUP CONTAINING AT LEAST 12 CARBON ATOMS AND X IS A DIRECT LINK OR -O-, -CONH- -SO2- OR SO2NH-, CORRESPONDING COMPOUNDS IN WHICH THERE IS A LINKING GROUP BETWEEN B AND Q AND CORRESPONDING COMPOUNDS IN WHICH THERE IS A LINKING GROUP BETWEEN Q AND THE PHENYL GROUP.
Inventors
- 👤 B Anderson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 08:29
CPC Classifications
C; C07; C07D; C07D231/00; C07D231/02; C07D231/10; C07D231/14; C07D231/44; C07D231/52
Claims Analysis
Total Claims: 0
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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) | 1976-06-11 | 1976-12-11 | 1977-06-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-06-11 | 1980-12-11 | 1981-06-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-06-11 | 1984-12-11 | 1985-06-12 | $7700.00 | Window Closed / Lapsed |