Novel sensitizers and their use in direct-positive photographic materials
US4311786A · kind A · utility
2Cited by
2References
14Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Jul 11, 1980 |
| Grant date | Jan 19, 1982 |
| Priority date | — |
| Expiry date | Jul 11, 2000 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03C1/4853
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
Direct-positive photographic material which has at least one layer which contains a silver halide emulsion surface-fogged by chemical means or by exposure and, as a sensitizer, a trinuclear tetramethinecyanine dye in which all or some of the methine hydrogen atoms have been replaced by fluorine, chlorine, bromine or iodine atoms. The novel trinuclear tetramethinecyanine dyes impart an excellent blue-sensitivity to the photographic materials. Furthermore, high maximum densities and very low minimum densities are achieved.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.