Phosphoric acid ester surface modifiers for silver carboxylate nanoparticles
US6387611B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 18, 2001 |
| Grant date | May 14, 2002 |
| Priority date | — |
| Expiry date | Jan 18, 2021 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG03C1/4989
- WIPO fieldOptics
- WIPO sectorInstruments
Abstract
There is disclosed an oxidation-reduction imaging forming composition comprising an aqueous based dispersion of (i) nanoparticulate silver carboxylate particles having on the surface of the particles a surface modifier which is a phosphoric acid ester and (ii) an organic reducing agent. In particular, the surface modifiers can be mixtures of mono- and di-esters of orthophosphoric acid and hydroxyl-terminated, oxyethylated long-chain alcohols or oxyethylated alkyl phenols or derivatives thereof. Also disclosed are various compositions including the dispersions including oxidation-reduction imaging forming compositions, thermographic elements and photothermographic compositions and elements. The preferred carboxylate is a silver salt of a long chain fatty acid such as silver behenate. A media milling method and a controlled precipitation method of making the dispersions are also disclosed
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.