JP2015045064A5 - - Google Patents

Claims (6)

A silver solution containing a silver complex and a reducing agent solution are quantitatively and continuously supplied into the flow path, and the silver complex is mixed in the reaction solution in which the silver solution and the reducing agent solution are mixed in the flow path. In the method for producing silver powder, which quantitatively and continuously reduces to obtain silver powder,
The ratio of the flow rate of the reducing agent solution supplied in the same direction as the supply direction of the silver solution from a pipe provided coaxially in the pipe to the flow rate of the silver solution in the pipe forming the flow path A method for producing silver powder, characterized in that the mixing ratio of the solution and the reducing agent solution is 1.5 or more.   The method for producing silver powder according to claim 1, wherein the silver solution is obtained by dissolving silver chloride in aqueous ammonia. The reducing agent is ascorbic acid;
The mixing ratio in mixing the silver solution and the reducing agent solution is set to 0.25 to 0.50 mol of the reducing agent with respect to 1 mol of silver. Silver powder production method.   The at least one selected from polyvinyl alcohol, polyvinyl pyrrolidone, a modified silicone oil surfactant, and a polyether surfactant as a dispersant is added to the reducing agent solution. 4. The method for producing silver powder according to any one of 3 above. Run average particle diameter of primary particles measured by査型electron microscopy is that 0.3 to 2.0 .mu.m, wherein the value obtained by dividing the average value of the standard deviation of the particle size is 0.25 or less And silver powder.   The ratio of the average particle diameter (BET diameter) calculated from the specific surface area determined by the BET method to the average particle diameter (SEM diameter) of the primary particles is 0.9 to 1.5. Silver powder of description.