Emulsions with the highest speeds compatible with low granularity
US5558981A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | May 15, 1995 |
| Grant date | Sep 24, 1996 |
| Priority date | — |
| Expiry date | May 15, 2015 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03C2001/093
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A radiation-sensitive emulsion is disclosed capable of producing the highest attainable speed compatible with low granularity. The silver halide grains (a) have a mean equivalent circular diameter of less than 0.6 .mu.m; (b) have a face centered cubic crystal lattice structure of the rock salt type; (c) have six {100} faces; (d) contain from 95 to 99.5 mole percent bromide ions and from 0.5 to 5 mole percent iodide ions, based on silver; (e) contain in the face centered cubic crystal lattice structure from 5.times.10.sup.-8 to 1.times.10.sup.-6 mole per silver mole of an iridium dopant comprised of Ir.sup.+3 ions forming coordination bonds with at least five halide ions occupying adjacent crystal lattice positions; and (f) contain in the face centered cubic crystal lattice structure from 1.times.10.sup.-5 to 3.times.10.sup.-4 mole per silver mole of a speed enhancing dopant comprised of divalent Group 8 metal ion chosen from among Fe.sup.+2, Ru.sup.+2 and Os.sup.+2 and at least one coordination ligand more electron withdrawing than fluoride ion; (g) the speed enhancing dopant is located in at least a portion of an internal region of the grains formed after 70 percent and before 90 …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.