Preparation of silica-coated calcium carbonates with increased surface area and mesoporosity
US11872294B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Dec 7, 2018 |
| Grant date | Jan 16, 2024 |
| Priority date | — |
| Expiry date | Mar 11, 2040 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08K2003/265
- WIPO fieldPharmaceuticals
- WIPO sectorChemistry
Abstract
This disclosure describes a process for preparing silica-coated calcium carbonate particles, involving the steps of preparing an aqueous carbonate slurry containing calcium carbonate particles, adding at least one silicate composition to the aqueous carbonate slurry to obtain a carbonate-silicate slurry, lowering a pH of the carbonate-silicate slurry by adding at least one acidic compound to obtain a pH-adjusted slurry containing the silica-coated calcium carbonate particles, and isolating the silica-coated calcium carbonate particles—in which at the adding of the acidic compound is controlled such that a final pH of the pH-adjusted slurry ranges from about 7 to about 10, and the silica-coated calcium carbonate particles include a porous coating having an average pore diameter ranging from 2 nm to 50 nm. This disclosure also describes articles and compositions containing the silica-coated calcium carbonate particles, as well as hollow silica spheres formed from the silica-coated calcium carbonate particles.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.