Process for the preparation of colloidal manganese dioxide
US5268408A · kind A · utility
5Cited by
6References
11Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Mar 20, 1991 |
| Grant date | Dec 7, 1993 |
| Priority date | — |
| Expiry date | Mar 20, 2011 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC01P2006/60
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
This invention relates to the preparation of antihalation layers for photographic film. The invention is an improved process for the preparation of colloidal manganese dioxide dispersions adapted for use in antihalation layers, the process comprising adding a reducing agent to an aqueous solution comprising a water soluble permanganate salt and a dispersing agent, the improvement wherein said dispersing agent is a water soluble polymer selected from the group consisting of water soluble carboxylated acrylic polymers, water soluble styrene/acrylic copolymers, and water soluble alpha-methyl styrene/acrylic copolymers.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.