摘要 |
A pigmentary material comprises silver in a lattice of crystalline zirconia, which material contains at least 0.4% weight of the silver. A process for preparing a pigmentary material comprising silver in a lattice of crystalline zirconia comprises calcining a zirconium component which yields the zirconia, and a silver component which yields the silver, forming a calcination mixture of the resultant zirconium and silver moieties and cooling the mixture, the weight of fluoride compound in the total weight of the components to be calcined being less than 6%. |