US3723128A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Photographic material containing filter dyes
Assignee: Ilford Imaging UK Ltd
•
Filing: 1971-06-02
•
Granted: 1973-03-27
•
Expires: 1991-06-02
Abstract
Abstract This invention relates to new polymethinoxanol dye-stuffs. They correspond to the formula WHEREIN X is the residue of a heterocyclic ring system and R1 and R2 are hydrogen atoms or optionally substituted alkyl or aryl groups. They are useful for incorporation in photographic silver halide material and able to correct various deficiencies of such material.
Inventors
- 👤 Donald E Mac
- 👤 F Campbell
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 21:45
CPC Classifications
C; C09; C09B; C09B23/00; C09B23/02; C09B23/06; G; G03; G03C; G03C1/00; G03C1/76; G03C1/825; G03C1/83; G03C1/832
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
15 words
Photographic material as claimed in claim 1, which contains a polymethinoxanol dyestuff of the formula
Claim 2
Dependent Claim
15 words
Photographic material as claimed in claim 1 which contains a polymethinoxanol dyestuff of the formula
Claim 3
Dependent Claim
15 words
Photographic material as claimed in claim 1 which contains a polymethinoxanol dyestuff of the formula
References Cited (Backward Citations)
US2533472A
Cited
US2611696A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-03-26 | 1976-09-25 | 1977-03-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-03-26 | 1980-09-25 | 1981-03-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-03-26 | 1984-09-25 | 1985-03-27 | $7700.00 | Window Closed / Lapsed |