| 摘要 |
<p>PURPOSE:To make it possible to manufacture a varistor having stabilized surge resistivity by a method wherein, after Sb2O3 which is one of subsidiary ingrendients is mixed in the main composition ZnO and they are pulverized, other subsidiary ingredient raw materials are added, mixed and pulverized, and the obtained molded body of mixed material is sintered. CONSTITUTION:Against ZnO of the main component raw material, Sb2O3 which is one of subsidiary component raw materials is mixed and pulverized, other subsidiary component raw material is added, mixed and pulverized, and the obtained molded body of mixed raw material is sintered. For example, Sb2O3 of 0.7mol% is added to ZnO of 98.8mol%, they are wet-mixed and pulverized in a ball mill for one hour, and a mixed and pulverized material is obtained. Then, Bi2O3 of 0.7mol% is added to ZnO of 97.8mol%, they are wet-mixed and pulverized by a ball mill for one hour, and a mixed pulverized material is obtained. Then, Bi2O3 of 0.5mol%, MnO of 0.5mol%, and Co2O$3 of 0.5mol% are added to the above-mentioned mixed pulverized material, they are wet-mixed and pulverized in a ball mill for 10 hours, and a mixed raw material is obtained. Consequently, as Sb2O3 can be uniformly dispersed into ZnO, particle- size distribution becomes small as Zn7Sb2O12 is uniformly formed by the reaction of Sb2O3 and ZnO when sintering and the growth of grains is controlled, and the concentration of current can be prevented.</p> |
