| 摘要 |
<p>PURPOSE:To reduce influence at the time of sintering and to improve discharge withstand current rating characteristic by providing a high resistance layer formed of a ceramic coating layer and a low melting point glass layer having a predetermined softening temperature on the side face of a sintered material containing zinc oxide as a main ingredient. CONSTITUTION:Electrodes 2 are provided on a pair of end faces of a columnar element assembly 1, and high resistance layers 3, 4 are provided on the side faces. The element assembly 1 mainly contains zinc oxide, and has voltage nonlinearity. The layer 3 is formed of a ceramic coating layer, and the layer 4 is a glass film produced by low melting point glass frit having a softening temperature of 350-800 deg.C. In the element assembly 1, 0.5mol% of Bi2O3, MnO, SiO2, Cr2O3 and 1mol% of Co3O3, Sb2O3, NiO are added to ZnO, and mixed with binder. The mixture is granulated by spraying to 100 microns of particle size, pressurized, molded and baked to obtain the element assembly 1. The ceramic coating material is formed by coating with butanol solution of tributoxy aluminum.</p> |
