Tabular grain emulsions with selected site halide conversions and processes for their preparation
US5723278A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 31, 1996 |
| Grant date | Mar 3, 1998 |
| Priority date | — |
| Expiry date | May 31, 2016 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03C2200/03
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A radiation-sensitive photographic emulsion is disclosed containing a gelatino-vehicle and tabular grains accounting for at least 70 percent of total grain projected area comprised of, prior to house conversion, at least 90 mole percent bromide and, after house conversion, up to 12 mole percent iodide, based on total silver, having {111} major faces that form corners joined by linear edges, and containing halide conversion dislocations that are confined to corner regions. Superior performance and selected site halide conversion can be realized by maintaining a pBr of less than 3.5 and by employing for halide conversion an iodide ion source exhibiting a second order reaction rate constant with the gelatino-vehicle of less than 10.sup.-3 mole.sup.-1 sec.sup.-1.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.