Ngk Insulators, Inc.

Masami Nakata

Osamu Imai

A voltage non-linear resistor having a voltage non-linear resistance element consisting mainly of zinc oxides and a high resistance layer including a zinc silicate phase consisting mainly of Zn.sub.2 SiO.sub.4 and a spinel phase consisting mainly of Zn.sub.7 Sb.sub.2 O.sub.12 has a continuous zinc silicate phase in which zinc silicate particles are arranged continuously. Therefore, in the voltage non-linear resistor according to the invention, a flashover can be preferably prevented, and thus a stable electric characteristics especially lightning discharge current withstanding capability can be obtained.

Voltage non-linear resistor

A voltage non-linear resistor excellent in varistor voltage characteristics, lightning discharge current withstanding capability and life performance against applied voltage comprises a disc-like voltage non-linear element and a thin insulating covering layer integrally provided on the side surface of said element. In the resistor according to the invention, said element comprises zinc oxides as main ingredient, 0.1-2.0% bismuth oxides, as Bi.sub.2 O.sub.3, 0.1-2.0% cobalt oxides, as CO.sub.2 O.sub.3, 0.1-2.0% manganese oxides, as MnO.sub.2, 0.1-2.0% antimony oxides, as Sb.sub.2 O.sub.3, 0.1-2.0% chromium oxides, as Cr.sub.2 O.sub.3, 0.1-2.0% nickel oxides, as NiO, 0.001-0.05% aluminum oxides, as Al.sub.2 O.sub.3, 0.005-0.1% boron oxides, as B.sub.2 O.sub.3, 0.001-0.05% silver oxides, as Ag.sub.2 O and 7-11% silicon oxides, as SiO.sub.2, and said layer comprises 45-60% silicon oxides, as SiO.sub.2, 30-50% zinc oxides, as ZnO, 1-5% bismuth oxides, as Bi.sub.2 O.sub.3 and antimony oxides for the remainder (% stands for mole %). The resistor of the invention preferably further comprises a thin glassy layer superimposed on the insulating covering layer. The resistors are advantageously adaptable to arrestors, surge absorbers used in high voltage power systems.

Voltage non-linear resistor and its manufacture

A voltage non-linear resistor excellent in lightning discharge current withstanding capability and electrical life performance against applied voltage comprises a disclike voltage non-linear element and a thin insulating covering layer integrally provided on the side surface of the element. In the resistor according to the invention, the element contains zinc oxides as main ingredient, 0.1-2.0% bismuth oxides, as Bi.sub.2 O.sub.3, 0.1-2.0% cobalt oxides, as Co.sub.2 O.sub.3, 0.1-2.0% manganese oxides, as MnO.sub.2, 0.1-2.0% antimony oxides, as Sb.sub.2 O.sub.3, 0.1-2.0% chromium oxides, as Cr.sub.2 O.sub.3, 0.1-2.0% nickel oxides, as NiO, 0.001-0.05% aluminum oxides, as Al.sub.2 O.sub.3, 0.005-0.1% boron oxides, as B.sub.2 O.sub.3, 0.001-0.05% silver oxides, as Ag.sub.2 O and 1-3% silicon oxides, as SiO.sub.2, and the layer contains 80-96% silicon oxides, as SiO.sub.2, 2-7% bismuth oxides, as Bi.sub.2 O.sub.3 and antimony oxides for the remainder (% stands for mole %). The resistor of the invention preferably further has a thin glassy layer superimposed on the insulating covering layer. The resistors are advantageously adaptable to arrestors, surge absorbers used in high voltage power systems.

A voltage non-linear resistor excellent in varistor voltage characteristics, lightning discharge current withstanding capability and life performance against applied voltage comprises a disclike voltage non-linear element and a thin insulating covering layer integrally provided on the side surface of said element. In the resistor according to the invention, said element comprises zinc oxides as main ingredient, 0.1-2.0% bismuth oxides, as Bi.sub.2 O.sub.3, 0.1-2.0% cobalt oxides, as Co.sub.2 O.sub.3, 0.1-2.0% manganese oxides, as MnO.sub.2, 0.1-2.0% antimony oxides, as Sb.sub.2 O.sub.3, 0.1-2.0% chromium oxides, as Cr.sub.2 O.sub.3, 0.1-2.0% nickel oxides, as NiO, 0.001,-0.05% aluminum oxides, as A1.sub.2 O.sub.3, 0.005-0.1% boron oxides, as B.sub.2 O.sub.3, 0.001-0.05% silver oxides, as Ag.sub.2 O and 7-11% silicon oxides, as SiO.sub.2, and said layer comprises 45-60% silicon oxides as SiO.sub.2, 30-50% zinc oxides, as ZnO, 1-5% bismuth oxides, as Bi.sub.2 O.sub.3 and antimony oxides for the remainder (% stands for mole %). The resistor of the invention preferably further comprises a thin glassy layer superimposed on the insulating covering layer. The resistors are advantageously adaptable to arrestors, surge absorbers used in high voltage power systems.

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Chita, Japan

Masami Nakata