| 摘要 |
PROBLEM TO BE SOLVED: To produce fine scaly silver powder suitable for a metallic paste material for a thick film process forming an electric circuit by mixing alkaline earth salt and silver oxide, roasting this mixture to produce metallic silver, subjecting the mixture to scaling treatment and dissolving away the alkaline earth metal salt with acid. SOLUTION: At least one kind of alkali earth metal salt (such as magnesium oxide, calcium oxide or the like) is mixed with silver oxide so as to regulate the weight of the silver oxide to 0.1 to 2 times that of the metallic silver produced by thermal decomposition. This mixture is roasted at 350 to 1200 deg.C in the air to form the silver oxide into metallic silver. The mixture is subjected to scaling treatment by a ball mill or the like, and after that, the alkaline earth salt is dissolved away with sulfuric acid or hydrochloric acid which do not dissolve the metallic silver. In this way, the fine scaly powder with 0.5 to 50μm average grain size suitable for a metallic paste material and a conductive coating material for a thick coating process forming an electric circuit in screen process printing or the like can easily be produced.
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