Characterization and Reproduction of "Fukiya Bengara", Noble Red Color Pigment, by Fe2O3-Al2O3 System

Human beings have been using "bengara" (α-Fe2O3) as red pigment ever since ancient times. As for Japan, the first artificial "bengara" was manufactured at Fukiya town in 1707, and it was mainly used for red painting of porcelain and other objects for about 300 years. However this "Fukiya bengara" cannot be manufactured anymore because of the environment pollution in spite of eagerness of potters to use it for producing bright yellowish red. At first step, we characterized traditional "Fukiya bengara" and found that α-Al2O3 existed. It is probably due to the formation of Al substituted α-Fe2O3. Then next step, we prepared red pigment of Fe2O3-Al2O3 system to investigate the Al substitution effect, by using both solid-state and polymerized complex methods. The red tone color depended on the particle size; the yellowish red pigment had the smallest size. Al substitution seemed to suppress the grain growth of hematite. The red tone color was controllable with the amount of Al substitution. α-(Fe0.9Al0.1)2O3 prepared at 1000°C for 2 hours presented as bright yellowish red color as that of "Fukiya Bengara".