纳米碳酸钙在外墙涂料中的应用研究

Study on Application of Nanometer Calcium Carbonate in Exterior Architectural Coatings

制备了纳米CaCO3复合外墙涂料,分别探讨了分散剂种类、分散剂用量、料浆浓度、分散时间和温度等因素对纳米CaCO3分散效果的影响,优化了操作工艺条件:纳米CaCO3料浆浓度为15%(质量分数),钛酸酯偶联剂用量为纳米CaCO3质量的3%,分散时间为1.0 h.考察了纳米CaCO3浆体加入量对外墙涂料耐沾污性、触变性、耐洗刷性、耐水性、耐碱性和耐老化性的影响,并用SEM对涂层进行了表征.结果表明:与传统建筑涂料相比,纳米复合外墙涂料的上述性能显著改善;当涂料中纳米CaCO3浆体的质量分数为3%～4%时,涂料性能的改善最为明显,其耐洗刷性达75 600次.

Nanometer calcium carbonate （abbreviated to nano-CaCO3） composite exterior architectural coatings were prepared. The influences of several factors, including the variety and dosage of dispersing agents, suspension concentration, dispersing time and temperature on the dispersion of nano-CaCO3, were investigated respectively. The technological conditions were optimized. It is concluded that the optimal technical parameters are： nano-CaCO3 suspension concentration is 15%（by mass）; titanate coupling agent dosage is 3%（by mass） of nano-CaCO3 ; dispersing time is 1.0 h. The influences of nano-CaCO3 content were studied upon the properties such as dirt resistance, thixotropy, scrub resistance, water resistance, alkali resistance and weathering resistance. The coatings were also characterized ,by SEM. The results show that, in comparison with traditional architectural coatings, the above mentioned properties of nano-CaCO3 composite coatings are remarkably improved. When nano-CaCO3 paste content in the coatings is 3%-4% （by mass）, the improvement appears to be perfectly noticeable, for example, with the scrub resistance reaching up to 75 600 times.