| 摘要 |
PROBLEM TO BE SOLVED: To easily and inexpensively produce silver powder in which each fine particle has a fine, flaky shape and high in uniformity by bringing an aq. soln. of silver nitrate into reaction with an. aq. soln. of L-ascorbic acid, furthermore adding ammonium polyacrylate thereto and precipitating silver particles. SOLUTION: The aq. solution of silver nitrate is brought into reaction with the aq. soln. of L-ascorbic acid as a reducer to precipitate silver particles. At this time, together with the L-ascorbic acid, ammonium polyacrylate is added thereto. As the ammonium polyacrylate, the one having about 10,000 to 400,000 molecular weight is preferable, and its amt. to be added is controlled to about 1.5 to 30 wt.% to silver. In this way, the lumping and spheroidizing of silver to be precipitated are prevented, and flaky silver powder of single piece suitable for producing silver paste is obtd. by a chemical one reaction system. Moreover, in the reaction, by allowing water soluble lower alcohol such as methanol to coexist, the more micronizing of the produced flaky silver powder can be attained.
|
