| 摘要 |
PURPOSE:To obtain powder uniformly plated with a noble metal in a high yield by treating powder to be plated or the powder and metallic powder for reduction with an org. acid and adding a noble metal-contg. soln. in two steps. CONSTITUTION:A water sol. acidic org. acid, pref. acetic acid is added to slightly sol. substance powder to be plated, e.g. metal or carbon powder, or the powder and metallic powder for reduction, e.g. copper or iron powder, and they are stirred for above 5 min to activate the surfaces of the powder and the reducing agent, thereby enhancing plating adherence and uniformity, and preventing formation of a noble metal film on the surface of the agent. A noble metal-contg. soln. is added to the above mixt. little by little in above 5 min in an amt. of 1/100-15/100 to the total amt., and the remainder is added rapidly. The soln. may be a silver nitrate soln. of arbitrary concn. The noble metal is thinly and uniformly coated onto the powder in the former addn., and then thickly and uniformly coated in the latter addn. They are stirred for several min, filtered, and dried to obtain uniformly plated powder. |
