| 摘要 |
PURPOSE:To provide the titled compsn. which gives a coating film having excel lent electrical conductivity, oxidation resistance and durability, consisting of a silver-coated copper powder obtd. by depositing metallic silver on the surface of metallic coppr powder by using a silver complex salt soln. CONSTITUTION:A silver salt (e.g. AgNO3), ammonium carbonate [(NH4)2CO3] and aqueous ammonia are mixed together to prepare a silver complex salt soln. Metallic copper powder (e.g. electrolytic copper powder) having the desired shape is added to distilled water, and while stirring it, the silver complex salt soln. is added dropwise thereto to deposit metallic silver on the surface of metallic copper powder. The resulting silver-coated copper powder (A) is washed and dried. A binder (B) such as methyl methacrylate resin is dissolved in an org solvent (C) (e.g. a solvent mixture of toluene and butyl acetate), and option ally 0.5-5wt% (based on the quantity of component A) suspending agent (D) is added. Component A in a quantity of 1-6 times by weight as much as the binder is mixed with the above soln. to obtain the titled compsn. composed of 20-80wt% of th combined quantity of components A, B and D and 80-20wt% component C.
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