Two powder synthesis of hydrotalcite and hydrotalcite-like compounds
US5728363A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 28, 1996 |
| Grant date | Mar 17, 1998 |
| Priority date | — |
| Expiry date | Mar 28, 2016 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC01P2006/12
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
There is provided an improved method for making synthetic hydrotalcite by first reacting powdered magnesium oxide with a high surface area, transition alumina in a solution or suspension to form a meixnerite-like intermediate. This intermediate is then contacted with an anion source such as an acid, and most preferably carbon dioxide, to form the layered double hydroxide which is separated from the suspension by filtering, centrifugation, vacuum dehydration or other known means. On a preferred basis, the transition alumina combined with activated magnesia consists essentially of an rehydratable alumina powder having a surface area of 100 m.sup.2 /g or greater. To make related double hydroxide compounds, still other reactants such as bromides, chlorides, boric acids, or salts thereof, may be substituted for the carbon dioxide gas fed into this suspension.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.