Patent ID: 7922938
Filing Date: 2011-04-12
Classification: B01J,B22F,B82Y

Abstract:
1. A process for producing a fine silver particle colloidal dispersion, which comprises: a reaction step of allowing an aqueous silver nitrate solution to react with a mixed solution of an aqueous iron(II) sulfate solution and an aqueous sodium citrate solution to form an agglomerate of fine silver particles; a ripening step of leaving the resultant reaction fluid containing the agglomerate of fine silver particles at a temperature of from 40° C. to 100° C. until the fine silver particles grow to an average diameter of from 20 nm to 200 nm thereby giving granular particles, to obtain an agglomerate of fine silver particles having grown to an average particle diameter of from 20 nm to 200 nm thereby giving granular particles; a filtration step of filtering the agglomerate of fine silver particles having grown to an average particle diameter of from 20 nm to 200 nm thereby giving granular particles, to obtain a cake of the agglomerate of fine silver particles; and a dispersion step of adding pure water to the cake to obtain the colloidal dispersion of the fine silver particles having an average particle diameter of from 20 to 200 nm.