Robust method for the preparation of high bromide tabular grain emulsions
US6043019A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 22, 1998 |
| Grant date | Mar 28, 2000 |
| Priority date | — |
| Expiry date | Dec 22, 2018 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03C2200/43
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A method is disclosed of manufacturing a radiation-sensitive tabular grain emulsion comprised of (a) providing in a stirred reaction vessel a host tabular grain emulsion containing greater than 50 mole percent bromide, based on silver, and a speed enhancing amount of iodide and (b) then introducing a silver salt solution into the stirred reaction vessel, wherein (1) the silver salt solution is introduced into the stirred reaction vessel at a rate sufficient to create a new grain population, (2) halting introduction of the silver salt solution for a time sufficient to allow the new grain population to be ripened out, and (3) repeating steps (1) and (2) from 3 to 20 times until silver introduced in steps (1) and (2) amounts to from 5 to 50 percent of total silver forming the radiation-sensitive tabular grain emulsion.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.