Core/shell emulsions with enhanced photographic response
US6593073B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 20, 1999 |
| Grant date | Jul 15, 2003 |
| Priority date | — |
| Expiry date | Dec 20, 2019 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03C2200/24
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A silver halide photographic element comprises at least one silver halide emulsion layer comprising a silver halide emulsion comprising core/shell silver halide grains wherein the core region comprises silver bromide with from about 5 to about 20% silver iodide and the shell region comprises silver bromide with about 0.1 to about 10% silver iodide and said layer contains a fragmentable electron donor compound of the formula X—Y′ or a compound which contains a moiety of the formula —X—Y′;whereinX is an electron donor moiety, Y′ is a leaving proton H or a leaving group Y, with the proviso that if Y′ is a proton, a base, &bgr;−, is covalently linked directly or indirectly to X, and wherein:1) X—Y′ has an oxidation potential between 0 and about 1.4 V; and2) the oxidized form of X—Y′ undergoes a bond cleavage reaction to give the radical X• and the leaving fragment Y′;and, optionally,3) the radical X• has an oxidation potential≦−0.7V.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.