Lateral high-resistance additive for zinc oxide varistor, zinc oxide varistor produced using the same, and process for producing the varistor

摘要

The invention aims at providing highly reliable zinc oxide varistors through simple production steps. The varistor is produced by dispersing a powdery raw material comprising 1-40 molar % (in terms of Fe. sub.2 O.sub. 3) iron, 0-20 molar % (in terms of Bi.sub.2 O.sub.3) bismuth, and the balance consisting of SiO.sub.2 in a solution of a water-soluble binder such as polyvinyl alcohol, and applying the formed dispersion to a molded or calcined zinc oxide varistor to form on the lateral face thereof a lateral high-resistance layer (2) containing Zn. sub.2 SiO.sub. 4 as the principal ingredient and a solid solution of iron in Zn.sub.7 Sb. sub.2 O. sub.12 as the auxiliary ingredient.