PIGMENTS STABLE AT HIGH TEMPERATURES

摘要

PIGMENTS STABLE AT HIGH TEMPERATURES of the Invention A pigment capable of withstanding elevated temperatures such as 175.degree.C is provided by the formation of a spinel of iron and other metal, such as Cu, Ca, Cd, Co, Ba, Sr, Mg, Mn, and Li. The pigment is made by a method which does not involve a step of calcining at high temperature, such as 600.degree.C to 1100.degree.C, but rather involves precipitation from aqueous solution and subsequent exposure to elemental oxygen, as by aeration, to form submicron-sized particles of desired spinel. Colors other than yellow may be obtained, and the spinels of Fe-Ba and Fe-Sr have magnetic properties.