镨黄色料粒径对其色度的影响

Effect of the Particle Size on the Chroma of Praseodymium Yellow Pigment

喷墨打印成为当前陶瓷装饰的主流技术,其技术关键是稳定的陶瓷墨水。为提高陶瓷墨水的稳定性,通常需求粒径分布窄的超细陶瓷色料。但是,色料的细化过程会改变色料的呈色及其在釉中的稳定性。为认识这种影响,本文以市售镨黄色料为研究对象,通过物理破碎改变色料的粒径。结果表明:当平均粒径(d50)从6.809μm减小到1.094μm时,镨黄色料的色度值从L*=82.49,a*=7.47,b*=72.70转变为L*=81.51,a*=-0.58,b*=56.41。镨黄色料在透明釉中也呈现相似的粒径-色度规律。这种变化是由于固相法合成的镨黄色料具有双层结构,黄色的Pr-ZrSiO_4在色料颗粒的表面,白色的ZrO_2在色料颗粒的核心。球磨导致的色料颗粒的破坏使得白色的ZrO_2核心裸露出来,降低了Pr-ZrSiO_4的浓度,减弱了色料的呈色。

At present, inkjet printing is the mainstream technology of ceramic decoration. The performance of ink is an important factor affecting the performance of the printing. In order to obtain highly stable ceramic ink, ultrafne ceramic pigment with narrow particle size distribution is required. However, the refning process of the ultrafne pigment will change the color stability of the pigment itself and in glaze. To understand this effect, the particle size of the commercially available praseodymium yellow pigment is changed through the physical crushing and then observed in the research. The results show that when the average particle diameter （d50） decreases from 6.809 μm to 1.094 μm, the chroma of the praseodymium yellow pigment changes from L^＊ =82.49, a^＊=7.47, b^＊=-72.70 into L^＊ =81.51, a^＊=-0.58, b^＊=-56.41. The similar tendency is shown in the praseodymium yellow pigment in transparent glaze. This change explains that the praseodymium yellow pigment prepared by solid phase synthesis method has double layer structure. Pr-ZrSiO4 is distributed on the surface of the pigment particles and white ZrO2 is in the core. The physical crushing induced by ball milling results in exposing white ZrO2 core, decreaseing Pr-ZrSiO4 concentration, and weakening coloration of the pigment.