Colorants for Ceramics

Abstract

AbstractMany ceramic products such as tile, sanitary ware, glasses, porcelain enameled appliances, are improved by the use of color. There are a number of ways to obtain color in a ceramic product. Transition‐metals ions can be melted into the glass or dispersed in a ceramic body when it is made. Color can also be obtained by inducing the precipitation of a colored matrix into a transparent matrix. The principal way is dispersal of a ceramic pigment into a vitreous matrix. The addition of oxides and ceramics has been known since antiquity. Several colors in bulk glass can be produced by precipitation. Most of the crystals used for ceramic pigments are complex oxides owing to their great stability in molten silicate glasses. Blues, yellows, browns, pinks, blacks, and grays are available in high purity. Greens and purples are available in fair purity; the purity of orange and red is very poor. All of the pigment colors are discussed. The various factors that must be addressed before selecting a pigment include processing stability, uniformity and reproducibilty, particle size, dispersibility, and compatibility