Methods of forming stable dispersions of photographic materials
US4990431A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 17, 1989 |
| Grant date | Feb 5, 1991 |
| Priority date | — |
| Expiry date | Jan 17, 2009 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03C1/005
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
The invention is performed by providing a first flow of water and surfactant, a second flow comprising solvent, base and photographic material, and mixing said first and second streams and either simultaneously or immediately following thereof neutralizing said streams to prevent hydrolysis of a hydrolyzable surfactant and/or premature precipitation of particles before neutralization. The streams then may be immediately treated for formation into photographic materials. In a preferred method the first and second stream may be brought together immediately prior to a mixer with addition of acid directly into the mixer to neutralize the dispersion of fine particles.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.