Patent ID: 7867935

Claim:
A highly arc-resistant insulator that is disposed and used in a vicinity of arcing that is generated between electrodes, the insulator comprising: a prescribed fluororesin filled with 0.5 to 1 weight % of a non-black insulating pigment that has a heat resistance such that discoloration does not occur when the fluororesin is baked, wherein the fluororesin is a polytetrafluoroethylene resin, and wherein the non-black insulating pigment is a pigment whose main component is a TiO 2 —CoO—NiO—ZnO system green insulating pigment, and wherein a hue (absorption wavelength) and a color density (filling rate) of the insulating pigment are optimized as a result of carrying out an evaluation of a wear rate for different insulators which are filled with different insulating pigments at different filling rates, and an evaluation of an absorbance area thereof taking into consideration a wavelength region or regions that have no influence of the wear rate.