Method of producing silver fine particles

Abstract

A method of producing silver fine particles includes continuously reducing silver ions contained in a silver compound to precipitate silver fine particles by introducing at least two fluids from separate flow paths and mixing the fluids, wherein one fluid of the at least two fluids contains the silver compound, and another fluid contains a reducing agent, and at least one fluid of the at least two fluids contains an amino acid. With this method, silver fine particles can be produced with sufficient continuous productivity and quality uniformity, without problems of deterioration of working environment and generation of explosive fulminating silver due to the use of a large amount of ammonia.

1 . A method of producing silver fine particles, comprising continuously reducing silver ions contained in a silver compound to precipitate silver fine particles by introducing at least two fluids from separate flow paths and mixing the fluids,
 wherein one fluid of the at least two fluids contains the silver compound, and another fluid contains a reducing agent, and   at least one fluid of the at least two fluids contains an amino acid.   
     
     
         2 . The method of producing silver fine particles according to  claim 1 , wherein formation of a silver mirror is suppressed by the amino acid. 
     
     
         3 . The method of producing silver fine particles according to  claim 1 , wherein the amino acid is contained in the fluid containing the silver compound. 
     
     
         4 . The method of producing silver fine particles according to  claim 1 , wherein 0.1 to 4 mol of the amino acid is used with respect to 1 mol of the silver ion. 
     
     
         5 . The method of producing silver fine particles according to  claim 1 , wherein a concentration of the silver ion in the fluid containing the silver compound is 0.1 to 5% by mass. 
     
     
         6 . The method of producing silver fine particles according to  claim 1 , wherein a dispersing agent is contained in at least one fluid of the at least two fluids. 
     
     
         7 . The method of producing silver fine particles according to  claim 1 , wherein the amino acid is glycine. 
     
     
         8 . The method of producing silver fine particles according to  claim 1 , wherein the at least two fluids are mixed between at least two processing surfaces arranged so as to be capable of approaching to and separating from each other, at least one of which rotates relative to the other. 
     
     
         9 . The method of producing silver fine particles according to  claim 1 , wherein ammonia is not used.