Hydrotalcites having a hexagonal needle-like crystal structure and process for production thereof
US4351814A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 18, 1980 |
| Grant date | Sep 28, 1982 |
| Priority date | — |
| Expiry date | Dec 18, 2000 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC01P2004/11
- WIPO fieldMaterials, metallurgy
- WIPO sectorChemistry
Abstract
Fibrous hydrotalcites having a hexagonal needle-like crystal structure. The fibrous hydrotalcites are produced by contacting a basic magnesium compound having a needle-like crystal structure and expressed by the following formula (2) EQU Mg(OH).sub.2-n'x.sbsb.2 A.sub.x.sbsb.2.sup.n'.spsp.-.m.sub.2 H.sub.2 O (2) wherein A.sup.n'.spsp.- represents a monovalent or divalent anion, n' is 1 or 2, and x.sub.2 and m.sub.2 are numbers satisfying the following conditions, EQU 0.2.ltoreq.x.sub.2 .ltoreq.0.5, EQU O.ltoreq.m.sub.2 .ltoreq.2, with a compound capable of providing a trivalent metal cation and being soluble in a liquid reaction medium which is chemically inert and is a non-solvent for the basic magnesium compound, the contacting being carried out in said liquid reaction medium under conditions which do not cause a loss of the needle-like crystal form of the basic magnesium compound, while maintaining the ratio of M.sup.3+ to the sum of Mg and M.sup.3+ at O<M.sup.3+ /(Mg+M.sup.3+).ltoreq.0.6 and the pH of the contacting system at not less than 9.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.