PRODUCTION OF COPPER POWDER

摘要

PROBLEM TO BE SOLVED: To produce a copper powder having a large grain diameter and a controlled grain diameter distribution by reducing a soln. of a cuprammonium complex with a solid L-ascorbic acid having a specified grain size. SOLUTION: The equimolar or more than the equivalent amt. of aq. ammonia is added to an aq. soln. of an inorg. copper compd. such as copper sulfate, copper nitrate, copper chloride and copper hydroxide or a copper compd. such as copper carboxylate to obtain a soln. of the cuprammonium complex such as copper ammonium sulfate, copper ammonium nitrate, copper ammonium chloride and copper ammonium acetate in water or aq. ammonia. A solid L- ascorbic acid having 0.1-10mm grain diameter is added to the soln. by 1-3mols per mol of the copper compd. when the cuprammonium complex is formed to bring about a reaction, and a copper powder having the optional grain diameter of 2-20μm and excellent in grain size distribution is obtained.