Silver halide emulsion containing iridium dopant
US6969582B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 16, 2004 |
| Grant date | Nov 29, 2005 |
| Priority date | — |
| Expiry date | May 26, 2024 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03C2001/093
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A silver halide emulsion comprising radiation sensitive silver halide grains exhibiting a face centered cubic crystal lattice structure containing a hexacoordination complex of an iridium ion in which at least half of the coordination sites in the hexacoordination complex are provided by halogen or pseudohalogen ligands, and at least one coordination site is provided by a ligand comprising a azole ring containing a chalcogen atom and a nitrogen atom, wherein the azole ring is substituted at the 5-position with a halide ion. The invention provides emulsions containing with a preferred class of iridium dopants which are especially useful for improving reciprocity performance in silver halide emulsions with minimal or no impact on other aspects of photographic performance. These dopants give a superior balance of reciprocity and other photographic properties compared to other iridium dopants exemplified in the prior art.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.