Two powder synthesis of hydrotalcite and hydrotalcite like compounds
US5728364A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 9, 1996 |
| Grant date | Mar 17, 1998 |
| Priority date | — |
| Expiry date | Apr 9, 2016 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC01P2006/82
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
There is provided an improved method for making synthetic hydrotalcite by first reacting a divalent metal compound with a trivalent metal oxide powder in a carboxylic acid-free, aqueous solution or suspension to form an intermediate. This intermediate is then contacted with an anion source such as carbon dioxide; a carbonate-containing compound; an acid or an ammonium salt to form a layered double hydroxide having the formula: A.sub.1-x B.sub.x (OH).sub.2 C.sub.z.mH.sub.2 O, where A represents a divalent metal cation, B represents a trivalent metal cation, C represents a mono- to polyvalent anion, and x, z and m satisfy the following conditions: 0.09<x<0.67; z=x/n, where n=the charge on the anion; and 2>m>0.5. Said layered double hydroxide is typically separated from the suspension by filtering, centrifugation, vacuum dehydration or other known means.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.