| 摘要 |
PURPOSE: To produce a monodisperse silver grain and to easily control the grain diameter by reducing a silver salt, etc., with a soln. using hydroquinone as a reducing agent and a sulfite as a reduction assistant and specifying the temp. of the soln. CONSTITUTION: A fine silver powder as the material for a silver paste for the circuit in the electronic industry is produced by reducing a silver salt or a silver-ammonium complex. In this case, hydroquinone is used as a reducing agent and a sulfite as the reduction assistant, and the soln. is controlled to 25-60 deg.C in the reduction reaction. A fine silver powder having 1-5μm grain diameter is obtained since the hydroquinone is used, the generation of quinone hardly soluble in water caused when hydroquinone alone is used is suppressed by the addition of the sulfite, and the fine silver powder is easily separated from the reaction soln. Further, the grain diameter of the fine silver powder to be obtained is controlled by controlling the temp. of the soln. when reduction is conducted.
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