Silver halide elements containing blocked pyrazolone magenta dye-forming couplers
US4283472A · kind A · utility
15Cited by
8References
18Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Feb 26, 1980 |
| Grant date | Aug 11, 1981 |
| Priority date | — |
| Expiry date | Feb 26, 2000 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03C7/384
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
Novel 5-pyrazolone magenta dye-forming couplers are blocked with a coupler moiety which yields an alkali-soluble or colorless reaction product. The coupler moiety is joined via its coupling position to the enol oxygen of the 5-pyrazolone and is displaced therefrom during processing as a result of reaction by means of oxidized color developing agent to thereby activate the 5-pyrazolone coupler. These couplers have good reactivity and good resistance to aerial contaminants, such a formaldehyde, and can be incorporated in photographic emulsions and elements.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.