熔盐法制备超细C@ZrSiO4色料及色度的研究

Synthesis and Chromaticity Properties of Superfine C@ZrSiO4 Pigment via Molten Salt Method

采用色素炭黑为碳源,无水四氯化锆和正硅酸乙酯分别为锆源和硅源,通过熔盐法制备了超细C@ZrSiO4色料。利用XRD分析了样品的晶体结构,同时采用SEM、TEM、CIE-L*a*b*色度仪和Zeta电位仪分别表征了C@ZrSiO4色料的显微形貌、呈色性能及分散稳定性。实验结果表明,相比于熔盐Na2MoO4、NaCl、LiCl和Na2SO4,Na2WO4熔盐的熔点与硅酸锆晶体的合成温度相近,同时两者具有优异的化学稳定性,有利于制备呈色优异的包裹色料。钨酸钠的引入提供了有利于传质的液相环境,抑制了色料颗粒间的团聚,制备出的C@ZrSiO4色料的粒度均匀细小(~500 nm)。随着熔盐用量的增加,C@ZrSiO4色料粒径逐渐减小,色度值随之升高。当Na2WO4/ZrSiO4摩尔比为0.2时,经900℃氮气气氛热处理2 h后,C@ZrSiO4色料的色度值L*=58.23,a*=0.10,b*=0.75。

Superfine C@ZrSiO4 pigment was synthesized by molten salt method,using carbon black as carbon source,zirconium tetrachloride(ZrCl4)and tetraethoxysilane(TEOS)as Zr and Si source,respectively.The phase composition of the sample was studied by means of X-ray diffraction patterns(XRD).Scanning electron microscopy(SEM),transmission electron microscopy(TEM),CIE-L*a*b*color system and zeta potentiometer were employed to study the morphology,chromatic and dispersion stability properties of the C@ZrSiO4 pigment,respectively.The experiment results indicated that the melting point of Na2WO4 closed to the synthesis temperature of ZrSiO4 compared with Na2MoO4,NaCl,LiCl and Na2SO4,and they both exhibited good chemical stability,which was more favorable to prepare inclusion pigment with excellent coloration.Moreover,it provided the liquid phase environment which preventing the agglomeration of pigment particles,resulting in the formation of nanoscale particles(~500 nm)with homogenous distribution.The particle size of C@ZrSiO4 pigment decreases gradually with increasing the amount of molten salt,while its chromatic value increases gradually.When the Na2WO4/ZrSiO4 ratio was 0.2,the optimal C@ZrSiO4 pigment calcined at 900℃for 2 h showed grey hue,as L*=58.23 a*=0.10,b*=0.75.