High chloride emulsions doped with iridium complexes
US6242172A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 30, 1999 |
| Grant date | Jun 5, 2001 |
| Priority date | — |
| Expiry date | Dec 30, 2019 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03C2200/39
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A radiation-sensitive emulsion is disclosed comprised of cubical silver halide grains containing from 0.05 to 3 mole percent iodide, based on total silver, and an iridium coordination complex dopant, wherein (i) the iodide is incorporated in the grains in a controlled, non-uniform distribution forming a core containing at least 50 percent of total silver, an iodide free surface shell having a thickness of greater than 50 .ANG., and a sub-surface shell that contains a maximum iodide concentration, and (ii) the iridium coordination complex dopant is incorporated into the sub-surface shell or into a region of the core extending up to 60% of the total silver into the grain from the sub-surface shell. Speed and reciprocity of iodochloride emulsions can be improved by localized addition of known in the art reciprocity-controlling iridium dopants in relation to high iodide region of the grain. By carefully incorporating reciprocity-controlling dopant within a well defined band within a grain the difficulties of the prior art can be overcome.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.