Method for preparing particles comprising a core and a silica shell
US6132773A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Oct 20, 1998 |
| Grant date | Oct 17, 2000 |
| Priority date | — |
| Expiry date | Oct 20, 2018 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/2989
- WIPO fieldBasic materials chemistry
- WIPO sectorChemistry
Abstract
The invention discloses a method for preparing particles comprising a dense silica shell and a core of another material, through rapid precipitation of active silica from a an aqueous alkaline metal silicate solution with pH adjustment by means of an acidifying agent, on a material support other than silica, separation of the silica slurry formed and drying of the recovered silica suspension. These composite particles consisting of a shell formed of dense silica and a non-polymer organic material core with biological, in particular phytosanitary, activity can be used for the slow release of the said solid non-polymer organic material with biological, in particular phytosanitary, activity, by slow diffusion through the silica shell.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.