Molybdate orange pigment with improved thermal stability
AssigneeE. I. Du Pont de Nemours and Company
InventorJames Francis Higgins
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Abstract
Molybdate orange pigment treated with from 0.1 to 30% of a boron compound. The boron-treated molybdate orange pigments when coated with dense, amorphous silica are particularly useful for coloring high temperature molding plastics.
Claims15
In a process for preparing molybdate orange pigment in aqueous medium by contacting an aqueous solution containing soluble salts of molybdate, sulfate and chromate with a salt of lead to form an aqueous slurry of precipitated pigment and applying porous silica and alumina to said precipitated pigment,
- wherein the improvement comprises adding from 0.1 to 30% by weight of a soluble boron compound, calculated as B.sub.2 O.sub.3, to said aqueous medium.
Molybdate orange pigment containing porous silica and alumina and from 0.015% to 0.1% by weight of boron, calculated as B.sub.2 O.sub.3.
Dependencies are inferred from the claim text.