| 摘要 |
A dielectric material which is able to detect a sign of insulation breakdown before use or while in use, and thus is able to predict the insulation breakdown in advance is provided. Such a dielectric material is made of a composite sintered compact in which conductive particles are dispersed in an insulating material, in which in the conductive particles, a particle diameter D10 having a cumulative volume percentage of 10% by volume in a volume particle size distribution is 0.2 μm or less, a particle diameter D90 having a cumulative volume percentage of 90% by volume is 2 μm or less, a ratio (D90/D10) of the particle diameter D90 having a cumulative volume percentage of 90% by volume to the particle diameter D10 having a cumulative volume percentage of 10% by volume is 3.0 or more, and a ratio (D90/D50) of the particle diameter D90 having a cumulative volume percentage of 90% by volume to the particle diameter D50 having a cumulative volume percentage of 50% by volume is 1.4 or more. |
