US2805158A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for colour photography
Assignee: Imperial Chemical Industries Ltd
•
Filing: 1953-10-01
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Granted: 1957-09-03
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Expires: 1973-10-01
Abstract
No abstract record available.
Inventors
- 👤 Ganguin Karl Otto
- 👤 Macdonald Eric
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 23:39
CPC Classifications
G; G03; G03C; G03C7/00; G03C7/18
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
133 words
A PROCESS FOR THE COLOUR CORRECTION OF A CYAN COLOURED COLOUR PHOTOGRAPHIC IMAGE LAYER FORMED BY EXPOSING A SILVER HALIDE LIGHT-SENSITIVE LAYER CONTAINING A COLOURLESS CYAN COLOUR FORMER SELECTED FROM THE GROUP CONSISTING OF PHENOLS AND NAPHTHOLAS UNSUBSTITUTED IN THE 4-POSITION TO THE HYDROXYL GROUP, TO THE LIGHT FROM A COLOURED OBJECT, COLOUR DEVELOPING TO FORM A CYAN IMAGE IN THE EXPOSED PARTS OF THE LAYER AND BLEACHING AND FIXING THE DEVELOPED SILVER, WHICH COMPRISES TREATING THE LAYER AT A STAGE SUBSEQUENT TO THE COLOUR DEVELOPMENT, WITH FORMALDRHYDE IN THE PRESENCE OF A PRIMARY AROMATIC AMINE TO FORM THE LEUCO DERIVATIVE OF A MASKING DYESTUFF BY REACTION WITH THE RESIDUAL COLOUR FORMER IN THE UNEXPOSED PARTS OF THE LAYER AND SUBSEQUENTLY OXIDISING THIS LEUCO DERIVATIVE TO FORM THE COLOUR CORRECTING MASKING DYESTUFF IMAGE.
Claim 2
Dependent Claim
133 words
A PROCESS FOR THE COLOUR CORRECTION OF A CYAN COLOURED COLOUR PHOTOGRAPHIC IMAGE LAYER FORMED BY EXPOSING A SILVER HALIDE LIGHT-SENSITIVE LAYER CONTAINING A COLOURLESS CYAN COLOUR FORMER SELECTED FROM THE GROUP CONSISTING OF PHENOLS AND NAPHTHOLAS UNSUBSTITUTED IN THE 4-POSITION TO THE HYDROXYL GROUP, TO THE LIGHT FROM A COLOURED OBJECT, COLOUR DEVELOPING TO FORM A CYAN IMAGE IN THE EXPOSED PARTS OF THE LAYER AND BLEACHING AND FIXING THE DEVELOPED SILVER, WHICH COMPRISES TREATING THE LAYER AT A STAGE SUBSEQUENT TO THE COLOUR DEVELOPMENT, WITH FORMALDRHYDE IN THE PRESENCE OF A PRIMARY AROMATIC AMINE TO FORM THE LEUCO DERIVATIVE OF A MASKING DYESTUFF BY REACTION WITH THE RESIDUAL COLOUR FORMER IN THE UNEXPOSED PARTS OF THE LAYER AND SUBSEQUENTLY OXIDISING THIS LEUCO DERIVATIVE TO FORM THE COLOUR CORRECTING MASKING DYESTUFF IMAGE.
References Cited (Backward Citations)
US2306410A
Cited
US2357388A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1960-09-02 | 1961-03-04 | 1961-09-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1964-09-02 | 1965-03-04 | 1965-09-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1968-09-02 | 1969-03-04 | 1969-09-03 | $7700.00 | Window Closed / Lapsed |