| 摘要 |
<p>PURPOSE:To reduce development of a void and to improve lightning surge discharge breakdown voltage by granulating, forming and calcinating a mixed material which is mainly composed of zinc oxide and contains one or more kinds of other metal oxides, by applying oxide paste to a side, by keeping it at a specified temperature range during main burning by temperature-up and by specifying relationship between a temperature holding time and a volume of a calcinated body. CONSTITUTION:A calcinated body is manufactured by granulating, forming and calcinating a mixed material which is mainly composed of zinc oxide and contains at least one or more kinds of other metal oxide. Oxide paste is applied to a side thereof and kept in a range of 820 to 1000 deg.C, preferably at an actually fixed temperature in an oxide atmosphere during temperature-up for main burning. A temperature holding time [t(time)] and a volume of a calcinated body [V (cm<3>)] has a relationship of (t)>=0.15V in the process. Meanwhile, a temperature does not need to be strictly fixed; the temperature may somewhat fluctuated inevitably in accordance with a device, various conditions, a scale, etc., of main burning and a temperature may be kept fluctuating intentionally.</p> |
