简介 |
PROBLEM TO BE SOLVED : To reduce the unevenness in varistor voltage among rough bodies in the same production lot and improve energy resistance by incorporating zinc oxide, specified subsidiary components and Ag. SOLUTION : Zinc oxide is wet-mixed with 0.1-5mol% oxide of a rare earth element, 0.01-1mol% oxide of an alkaline earth metal, 0.0001-0.6mol% oxide of a trivalent metal and 0.1-5mol% cobalt oxide as subsidiary components and 0.005-0.5mol% Ag and the resultant wet mixture is dried to form a powdery mixture. This mixture is mixed with a bonding resin, granulated and compacted to obtain a compact. The binder is removed from the compact by calcining at 700-1, 000 and then the compact is fired at 1, 100-1, 450 deg.C. |