Method for preparing a light-sensitive emulsion having (100) tabular grains rich in silver chloride
US6083678A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 9, 1998 |
| Grant date | Jul 4, 2000 |
| Priority date | — |
| Expiry date | Oct 9, 2018 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03C2200/01
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
A method has been described for preparing a light-sensitive silver halide photographic emulsion comprising performing at least three distinct precipitation steps in an aqueous medium into a reaction vessel, followed by desalting by means of flocculation and washing or by means of ultrafiltration, said emulsion comprising a colloidally stabilizing binder and {100} tabular silver halide grains containing at least 50 mole % of silver chloride, wherein at least 60% by number of all grains is provided by said tabular grains, and wherein said tabular grains exhibit an average aspect ratio of at least 2, an average thickness of at most 0.25 .mu.m with a variation coefficient of at most 0.25, and an average equivalent circular crystal diameter of 0.3 .mu.m or more with a variation coefficient of at most 0.20; PA0 said three distinct precipitation steps being a nucleation step and two growth steps, said method being further characterized by introducing after ending the said nucleation step one or more crystal dislocation(s) onto nuclei formed in the said nucleation step in order to provide anisotropic growth of the said nuclei into {100} tabular grains, PA0 wherein introducing said crystal …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.