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AssigneeRhodia Terres Rares
InventorJean-Yves Chane-Ching
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The invention relates to an aqueous colloidal dispersion of a compound of cerium and at least one other element M chosen from among the rare earths other than cerium; titanium, vanadium, chromium, manganese, iron, cobalt, nickel, copper, zinc, aluminium, gallium and zirconium. This dispersion is characterized in that it displays a conductivity of at most 5 mS/cm. It is obtained by a process in which there is reacted with a base a mixture of at least one salt of cerium with at least one salt of an element M mentioned above and in the presence of an acid in a quantity such that the atomic ratio H+/(Ce+M) is greater than 0.1, then the precipitate from the preceding reaction is re-dispersed in water. The dispersions of this type cane be used in catalysis, in lubrication, in ceramics, in the manufacture of luminophorous compounds, in cosmetics and as anticorrosion agents.
An aqueous colloidal dispersion of a compound of cerium and at least one other element M selected from the group consisting of rare earths other than cerium and titanium, vanadium, chromium, manganese, iron, cobalt, nickel, copper, zinc, aluminium, gallium and zirconium, which displays a conductivity of at most 5 mS/cm, and which has a pH of between 5 and 8.
A process for preparing a colloidal dispersion of a compound of cerium and at least one other element M selected from the group consisting of rare earths other than cerium and titanium, vanadium, chromium, manganese, iron, cobalt, nickel, copper, zinc, aluminium, gallium and zirconium, which displays a conductivity of at most 5 mS/cm, the process comprising reacting a base mixture of at least one salt of cerium with at least one salt of an element M in the presence of an acid in a quantity such that the atomic ratio H+/(Ce+M) is greater than 0.1;
Dependencies are inferred from the claim text.