INFRARED REFLECTIVE COLOR PIGMENT
The present invention provides new solid solutions having a corundum-hematite crystalline structure which are useful as inorganic color pigments. Solid solutions according to the present invention include a host component having a corundum-hematite crystalline structure which contains as guest components one or more elements from the group consisting of aluminium, antimony, bismuth, boron, chrome, cobalt, gallium, indium, iron, lanthanum, lithium, magnesium, manganese, molybdenum, neodymium, nickel, niobium, silicon, tin, titanium, vanadium, and zinc. Solid solutions according to the present invention are formed by thoroughly mixing compounds, usually metal oxides or precursors thereof, which contain the host and guest components and then calcining the compounds to form the solid solutions having the corundum-hematite crystalline structure. Some of the new solid solutions according to the present invention exhibit relatively low Y CIE tri-stimulus values and relatively high near infrared reflectance.