复合包裹法制备C@SiO_2@ZrSiO_4黑色色料的研究

C@SiO_2@ZrSiO_4 Black Pigment Prepared by Composite Coating Method

采用四氯化锆、正硅酸乙酯为前驱体,色素炭黑为着色剂,LiF为矿化剂,聚乙烯醇缩丁醛(PVB)为分散剂,通过复合包裹法制备了C@SiO_2@ZrSiO_4黑色包裹色料。运用FTIR、XRD、CIE-L*a*b*色度仪和TEM研究了ZrSiO_4用量、合成温度和保温时间对硅酸锆合成及色料色度的影响。实验结果表明,炭黑颗粒先后被SiO_2层和ZrSiO_4层包覆,SiO_2层有利于炭黑与ZrSiO_4的结合。ZrSiO_4/C摩尔比为0.85时最适合制备ZrSiO_4包覆层,较低的比率会影响硅酸锆的合成,导致杂质相ZrO_2和SiO_2出现;大于该比率则会导致ZrSiO_4包裹层过厚,同样不利于色料发色。此外,热处理制度对色度有明显影响,经氮气气氛1000℃热处理2 h,空气气氛800℃热处理2 h后,合成的C@SiO_2@ZrSiO_4黑色包裹色料的色度值为L*=52.37,a*=0.90,b*=2.77。

C@SiO_2@ZrSiO_4 black inclusion pigment was prepared by composite coating method, using zirconium tetrachloride and tetraethoxysilane as precursors, carbon black as colorant, LiF as mineralizer and polyvinyl butyral（PVB） as dispersant, respectively. The effects of ZrSiO_4/C ratios, heat treatment on the synthesis and chromatic value of the pigment were studied by using FTIR, XRD, TEM and CIE-L＊a＊b＊ color system. The results show that the carbon black particles can be well coated by SiO_2 and ZrSiO_4 layer, and the SiO_2 layer is beneficial to the connection between carbon black and ZrSiO_4 layer. The optimal ZrSiO_4/C ratio for the synthesis of ZrSiO_4 is 0.85. Too low ZrSiO_4/C ratio influences the synthesis of ZrSiO_4, resulting in the impurities of ZrO_2 and SiO_2. When the ratio is larger than 0.85, the ZrSiO_4 layer is too thick, causing the poor chromatic performance. Heat treatment has a significant effect on the chromaticity. Its CIE coordination is L＊=52.37, a＊=0.90, b＊=2.77, which can be obtained after being heat treated in nitrogen atmosphere at 1000 ℃ for 2 h and then in air at 800 ℃ for 2 h.