Method for manufacturing nano-scaled copper powder by wet reduction process

Abstract

The present invention relates to a method for manufacturing a nano-scaled copper powder by a wet reduction process, comprising adding appropriate amounts of sodium hydroxide (NaOH) and hydrazine (N 2 H 4 ) to an aqueous copper chloride (CuCl 2 ) solution to finally obtain a copper powder having a particle size of 100 nm (0.1 nm) grade via an intermediate product such as a copper complex.

1 . A method for manufacturing a nano-scaled copper powder by a wet reduction process, comprising the steps of: 
 adding sodium hydroxide (NaOH) to an aqueous copper chloride (CuCl 2 ) solution to give an aqueous solution containing copper oxide and copper hydroxide;    reducing the copper oxide and the copper hydroxide to obtain a nano-scaled copper powder as a precipitate by adding hydrazine (N 2 H 4 ) to the aqueous solution; and    filtering and drying the precipitated nano-scaled copper powder.    
     
     
         2 . The method as set forth in  claim 1 , wherein the sodium hydroxide (NaOH) is added in an amount of 2 to 33 moles per mole of the copper chloride (CuCl 2 ) when the aqueous copper chloride (CuCl 2 ) solution is kept within a temperature of 30 to 80° C., and the hydrazine (N 2 H 4 ) is added in an amount of 0.5 to 12 moles per mole of the copper chloride when the aqueous solution containing the copper oxide and the copper hydroxide is kept within a temperature of 40 to 80° C.  
     
     
         3 . The method as set forth in  claim 1 , wherein in the step of producing the copper oxide and the copper hydroxide, before the addition of NaOH, silver nitrate (AgNO 3 ) is added to the aqueous copper chloride (CuCl 2 ) solution in an amount of 1/1,000 to 1/10,000 moles per mole of the copper chloride.  
     
     
         4 . A method for manufacturing a nano-scaled copper powder by a wet reduction process, comprising the steps of: 
 adding hydrazine (N 2 H 4 ) to an aqueous copper chloride (CuCl 2 ) solution to give an aqueous solution containing a copper complex (Cu(N 2 H 4 ) m Cl n );    adding sodium hydroxide (NaOH) to the aqueous copper complex solution to obtain a nano-scaled copper powder; and    filtering and drying the nano-scaled copper powder.    
     
     
         5 . The method as set forth in  claim 4 , wherein the hydrazine (N 2 H 4 ) is added in an amount of 0.5 to 12 moles per mole of the copper chloride (CuCl 2 ) when the aqueous copper chloride (CuCl 2 ) solution is kept within a temperature of 20 to 70° C., and the sodium hydroxide (NaOH) is added in an amount of 2 to 33 moles per mole of the copper chloride when the aqueous solution containing the copper complex is kept within a temperature of 40 to 80° C.  
     
     
         6 . The method as set forth in  claim 4 , wherein in the step of producing the copper complex (Cu(N 2 H 4 ) m Cl n ), before the addition of hydrazine, silver nitrate (AgNO 3 ) is added to the aqueous copper chloride (CuCl 2 ) solution in an amount of 1/1,000 to 1/10,000 moles per mole of the copper chloride.