| 摘要 |
PURPOSE:To markedly improve the characteristic of irregularity in varistor voltage by a method wherein the quantity of a specific metal within the range of solid solution is added and mixed to ZnO, they are sintered, the pulverized particle are mixed in a specific solution, and after they have been spray-dried while they are being stirred, the molded and calcined pulverized powder of sintered body is blended with glass and an organic vehicle. CONSTITUTION:The quantity within the range of solid solution of ZnO of at least one or more kinds selected from cobalt, manganese, chromium, and aluminum are added to ZnO, and after they have been mixed and calcined, they are reduced to powder. Then, a solution containing ions of bismuth, cobalt, manganese and zinc is formed, calcined pulverized grains of ZnO is mixed into said solution, and a spray drying operation is conducted while the mixture is being stirred up. After the ZnO varistor sintered body, obtained by molding and sintering the above-mentioned powder, has been pulverized into ultrafine powder using a jet mill and the like, the powder is classified in such a manner that they become the suitable range of grain diameter, and highly homogenous glaze varistor can be obtained by blending said ZnO varistor grains with glass and organic vehicles. |
