| 摘要 |
PURPOSE: To decrease limited voltage and to reduce the protection level as a lightning arrester by a method wherein the reaction product, obtained by temporarily firing the mixture of ZnO, B2 O3 , SiO2 , Al(NO3 )3 and 9H2 O, is used as an additional component. CONSTITUTION: The second subsidiary additive component is obtained by mixing ZnO (40 to 80mol%), B2 O3 (10 to 40mol%), SiO2 (5 to 25mol%), and Al(NO3 )3 .9H2 O (0.003 to 0.006mol% in terms of Al) is added to the above-mentioned component. After this mixture has been wet-pulverized, the pulverized material is dried up, temporarily fired at 850 deg.C or higher, finely ground, and a reaction product is obtained. Besides, it is desirable that the blending ratio of the adding component is set at 0.05 to 0.5wt.% against the main raw material of zinc oxide. As a result, limited voltage is attenuated, and the protection level as a lightning arrester can be lowered. |
