Increased activity precipitated photographic materials
US5008179A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 22, 1989 |
| Grant date | Apr 16, 1991 |
| Priority date | — |
| Expiry date | Nov 22, 2009 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S430/136
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
The invention is accomplished by providing an aqueous dispersion of a photographic coupler by precipitation from a solvent solution by solvent and/or pH shift. A second aqueous dispersion of an activating permanent solvent for the photographic coupler is also provided. The dispersion of activating permanent solvent and photographic coupler are combined to form a combined dispersion which is mixed with a gelatin dispersion of silver halide particles to form a photographic emulsion suitable for casting as a photographic element. In a preferred method of the invention, the activating solvent is incorporated into a dispersion of latex particles prior to being combined with the dispersion of photographic coupler.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.