Photographic contrast enhancers
US4363873A · kind A · utility
5Cited by
4References
5Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Sep 14, 1981 |
| Grant date | Dec 14, 1982 |
| Priority date | — |
| Expiry date | Sep 14, 2001 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03C7/39236
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
As silver is the most expensive individual component in photographic film, it is desirable to reduce the quantities of silver in such materials. The addition of a certain class of phenolic derivatives has been found to enhance the contrast generated by dyes in color photographic emulsions. Emulsions containing these phenolic compounds can use less silver and produce the same optical density as emulsions with higher silver concentrations.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.