Metal oxide voltage-variable resistor composition

Abstract

A metal oxide resistor of the type consisting essentially of zinc oxide and containing significant amounts of the impurities bismuth trioxide, cobalt trioxide, manganese dioxide, antimony oxide, chromic oxide, and silicon dioxide contains also significant amounts of the impurities barium oxide and boron oxide.

We claim: .[.1. A voltage-variable sintered body resistor composition of the type consisting mostly of zinc oxide and comprising a significant amount of silicon dioxide, wherein the improvement comprises that said composition also contains significant amounts of at least one of the impurities chosen from the group consisting of barium oxide and boron 
     
        oxide..]. 2. The composition defined in claim .[.1.]. .Iadd.6 .Iaddend.wherein the barium oxide is present to a concentration of on the 
     
     
        order of 0.1 molar percent. 3. The composition defined in claim .[.1.]. .Iadd.8 .Iaddend.wherein the boron oxide is present to a concentration of 
     
     
        on the order of about 0.1 molar percent. 4. The composition defined in claim .[.1.]. .Iadd.6 .Iaddend.and comprising additionally at least one impurity chosen from the group consisting of bismuth trioxide, cobaltic 
     
     
        trioxide, manganese dioxide, antimony oxide, and chromic oxide. 5. The composition defined in claim 4 and comprising: about .Badd..[.96.55.]. .Iadd.96.55 .Iaddend.molar percent zinc oxide,   about 0.5 molar percent bismuth trioxide,   about 0.5 molar percent cobaltic trioxide,   about 0.5 molar percent manganese dioxide,   about 1.0 molar percent antimony trioxide,   about 0.5 molar percent chromic oxide,   about 0.1 molar percent barium oxide,   about 0.1 molar percent boron oxide, and   about 0.25 molar percent silicon, dioxide. .Iadd. 6. An improved zinc oxide varistor composition of the type containing silicon dioxide as an impurity the improvement which comprises:   the addition of an effective amount up to 0.3 molar percent each of barium oxide and boron oxide impurities. .Iaddend.