超细银粉的制备及其导电性研究

用化学还原法在醇水体系中制备出平均颗粒粒径为 0.8~1.2 μm、分散性好的超细球银。讨论了表面活性剂、还原剂的种类、温度、硝酸银含量及 pH 值对球银颗粒粒径和分散性的影响。将所得超细球银在水体系中高效率球磨得分散性好的光亮片状银粉,平均粒径<6 ìm,比表面积 0.7~1.3 m2/g。讨论了吸附在银粉表面的有机物的种类和比表面积对片银导电性能的影响,结果表明:比表面积越大,导电性越好。

Preparation of Ultrafine Silver Powder and Its Electrical Properties

In alcohol-water system, AgNO3 is reduced to ultrafine spherical silver powders with average particle size 0.8~1.2 ìm and excellent dispersity by chemical reduction method. The effect of reductant, the content of silver nitrate, reaction temperature and pH value on particle size and dispersity of spherical silver powder were analyzed. The ultrafine flake silver powder in excellent dispersity was prepared by milling above-mentioned ultrafine spherical silver powder in aqueous medium. Particle size of the flake silver powder is less than 6 ìm, and its specific surface area in the range from 0.9 to 1.3m2/g. The influences of the kind of surfactant and specific surface area on electrical properties of flake silver powder were investigated, and the results show that conductibility of flake silver powder increases with the increasing specific surface area.