CoAl_2O_4蓝色的色料粒径对其色度的影响

Effect of the Particle Size of CoAl_2O_4 Blue Pigment on the Chroma of the Pigment

目前,喷墨打印成为陶瓷装饰的主流技术。墨水的性能是影响喷墨打印效果的重要影响因素。为获得高稳定性的陶瓷墨水,需求粒径小、粒径分布窄的陶瓷色料。但是,超细的色料会改变其对光的吸收和反射,影响其在釉中的稳定性,进而影响其呈色。本论文采用燃烧法制备的超细CoAl_2O_4蓝色色料,通过粒度分布仪和CIE色度仪表征其粒径和色度。结果表明:砂磨机球磨10 h,可使粉体的平均粒径(d_(50))从6.40μm减小到0.33μm。相应地,CoAl_2O_4色料的色度值从L*=49.82,a*=0.05,b*=-50.90转变为L*=56.42,a*=-13.15,b*=-28.02。这说明随着粒径的减小,色料的明度增加,呈色鲜艳。但是b*值降低,色料的蓝色由深蓝转变为浅蓝。CoAl_2O_4色料在透明釉中也呈现相似的粒径-色度规律,但其影响较小。这规律有助于调控喷墨打印中蓝色的比例,以获得既定图案的颜色。

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 CoAl_2O_4 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（d_（50）） of the pigment can be reduced from 6.403 μm to 0.336 μm after 10 h. Accordingly,the chroma of CoAl_2O_4 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 Co Al_2O_4 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.