Method for chemically sensitizing silver halide photographic emulsion
US5679507A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 25, 1995 |
| Grant date | Oct 21, 1997 |
| Priority date | — |
| Expiry date | Aug 25, 2015 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03C2200/43
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A method for chemically sensitizing a silver halide photographic emulsion with a selenium compound is disclosed. The sensitizing method comprises the steps of PA1 preparing a dispersion of solid particles of a selenium compound in an aqueous medium by a process comprising the following steps of PA2 (1) dissolving a substantially water-insoluble organic selenium compound in a substantially water immiscible low-boiling organic solvent to prepare a selenium compound solution, PA2 (2) dispersing the selenium compound solution in water or an aqueous solution of a dispersing aid to form a oil-in-water type dispersion, and PA2 (3) removing the organic solvent from the oil-in-water type dispersion by stirring the dispersion under a decompressed condition to precipitate the selenium compound so as to form a dispersion of fine solid particles of the selenium compound having an average particle size of 10 nm to 3 .mu.m; PA1 adding the solid dispersion particles of the selenium compound to a silver halide emulsion, and PA1 ripening the silver halide emulsion in the presence of the solid dispersion particles of the selenium compound.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.