Silver halide precipitation process with deletion of materials through the reaction vessel
US4336328A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 11, 1981 |
| Grant date | Jun 22, 1982 |
| Priority date | — |
| Expiry date | Jun 11, 2001 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03C2200/09
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
An improved silver halide precipitation process of preparing a dispersion of silver halide grains is disclosed. The process comprises forming a radiation-sensitive silver halide dispersion by reacting silver and halide salts in solution within a dispersing medium to form silver halide grain nuclei within the dispersing medium and allowing silver halide grain growth to occur in a reaction vessel in which the silver halide grain nuclei and the dispersing medium are present. The improvement comprises, during silver halide grain growth, withdrawing a portion of the dispersing medium from the reaction vessel through an ultrafiltration membrane while retaining the silver halide grains within the dispersing medium remaining within the reaction vessel.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.