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US 4,216,188 AGranted
Cross-linked montmorillonite molecular sieves
AssigneeYeda Research and Development Co. Ltd.
InventorsJoseph Shabtai, Noam Lahar
Life of this patent
Estimating the term…
Abstract
Novel molecular sieves, being montmorillonites cross-linked with aluminum hydroxide or with chromium hydroxide and a process for the production of same comprising interaction between montmorillonite, in the form of a colloidal solution containing fully separated unit layers (reactant A), and a cross-linking agent, consisting of an accurately buffered and aged colloidal solution of a metal hydroxide, dispersed in the form of low molecular weight oligomers (reactant B).
Claims15
A process for the production of molecular sieves with comprises
- reacting a colloidal solution of a monoionic montmorillonite having a concentration of 100 mg to 800 mg montmorillonite per liter, in the form of fully dispersed negatively charged unit layers at room temperature, with an aged sol of a metal hydroxide aged for at least 5 days at ambient temperature, said metal hydroxide being selected from the group consisting of aluminum hydroxide and chromium hydroxide, at a pH adjusted below the zero charge point having a residual net positive charge on the said metal hydroxide, under vigorous agitation, resulting in a rapid flocculation of the montmorillonite cross-linked with said metal hydroxide, separating the product from the liquid phase, and stabilizing the product by heat treatment.
Dependencies are inferred from the claim text.