溶胶-凝胶法制备二氧化硅包覆水性C.I.P R 31

Synthesis of silica coated waterborne C.I.P R 31 by sol-gel method

摘要:

以3-氨基-4-甲氧基苯甲酰苯胺（红色基KD）和2-羟基-3-萘甲酰基间硝基苯胺（色酚AS-BS）为中间体，通过重氮化和偶合反应，制备了单偶氮红色系C.I.PR31，偶合过程中首先选用松香酸对其进行水性化改性处理，进而通过溶胶-凝胶法在颜料表面包覆了1～3层的SiO2颗粒层。经接触角、SEM、TEM、色光、热重分析测试，结果表明：经过松香酸处理的颜料样品晶体形貌可由长条状转变为圆片状，极性明显增强。松香酸用量为总反应物质量的3%时，颜料与水之间的接触角降至52.8°，粒径分布峰值和粒径分布宽度分别降至78nm和0.01~0.54μm，具有较佳的亲水性能。包覆2层及2层以上的SiO2可使颜料接触角降至0°，完全转为亲水性。松香酸的加入在一定程度上会导致颜料色样偏向红色和蓝色，而SiO2颗粒层则使颜料偏向绿色和蓝色。包覆2层SiO2的C.I.PR31*-2SiO2色差（ ΔE）为0.96，着色力可达105.09，氮气气氛中加热至290℃颜料晶体开始分解，达到了耐高温颜料的标准，可以用于水性分散介质。

Abstract:

Monoazo C.I.PR31 was prepared using 3-amino-4-methoxybenzanilide (red base KD) and 2-hydroxy-3-naphthoyl m-nitroaniline (naphthol AS-BS) as intermediates by diazotization and coupling reaction. Rosin acid was used as surface modification agent of the pigment in the coupling process, then silica dioxide particles with 1~3 layers were coated on the pigment surface by sol-gel method. The samples were characterized by contact angle measurement, SEM, TEM, color capability and thermogravimetric analysis. The results showed that after the pigment was treated by rosin acid, its crystal morphology changed from long strip to disk shapes, and its polarity was obviously enhanced. When the amount of rosin acid was 3% of the total mass of reactants, the contact angle between the obtained pigment and water was 52.8°, the mean particle size and the particle size distribution were 78 nm and 0.01~0.54 μm, respectively, and the pigment sample exhibited good hydrophilic property. The pigments coated with 2 layers and more than 2 layers of silica dioxide with contact angle values of 0° were completely hydrophilic. The introduction of rosin acid made the pigment hues convert into red and blue, while that of the silica dioxide layer made the pigment hues convert into green and blue. The color difference (ΔE) and tinting strength of the pigment sample with 2 layers of silica dioxide, C.I.PR31*-2SiO2, were 0.96 and 105.09, respectively. In nitrogen environment, the pigment crystals began to decompose at 290℃. It is obvious that the pigment reached the standard of high temperature resistant pigment and could be used in aqueous dispersion system.