WANG Xia ¹, HU Shuyun ², WANG Qikun ², CHANG Qibing ², WANG Yongqing ², ZHOU Jian-er ²

(1. Science and Art collage of Jingdezhen Ceramic Institute, Jingdezhen 333001, iangxi, China; 2. School of Materials Science and Engineering of Jingdezhen Ceramic Institute, Jingdezhen 333403, Jiangxi, China)

Abstract: At present, inkjet printing is the mainstream technology of ceramic decoration. The performance of the ink is an important factor affecting the performance of the printing. In order to obtain the high stable ceramic ink,the ceramic pigment is required which has the small particle size and the narrow particle size distribution. However, the ultrafine pigment will change the light absorption and the light reflection, which has the influence on its stability of glaze and its chroma. In the present work, the ultrafine CoAl₂O₄ blue pigment was prepared by combustion method and was characterized by particle size analyzer and CIE colorimetric apparatus. The results show that the average particle size (d50) of the pigment can be reduced from 6.403 μm to 0.336 μm after 10 h. Accordingly, the chroma of CoAl₂O₄ pigment changes from L^* =49.82, a^*=0.05, b^*=-50.90 into L^*=56.42, a^*= -13.15, b^*= -28.02. This indicates that the brightness of color increase with the decrease of the particle size and generates the bright color. However, the b* value decreased, the blue pigment changes from the dark blue to light blue. The colorof CoAl₂O₄ in the transparent glaze is similar to the pigment itself. This rule is helpful to controlling the proportion of blue ink in the inkjet printing to obtain the color of the designed pattern.

Key words: CoAl₂O₄ pigment;Inkjet printing; Combustion; Particle size; Chroma