Fluorinated SnO2/ER as an antistatic coating for enhancing the surface insulating strength of epoxy insulators

The surface coating of epoxy resin has been widely used in the composite materials with micron scale fillers, but the related research on the composite coating filled with nanoparticles is still rare. SnO2 is a common antistatic additive in composite materials, and it is also a semiconductor material, capable of uniform voltage. In this paper, nano‐SnO2 powder was considered as the filler of coating materials. By analyzing the microscopic test results, the flashover voltage, surface charge dissipation, and surface conductivity of the coating sample, the effects of coating treatment and nano‐SnO2 fluorination on the surface insulation properties of epoxy insulators were studied. It is found that the flashover voltage and surface charge dissipation rate of the coating sample can be improved by both coating treatment and fluorination treatment, thus improving the surface insulation performance of epoxy insulators. The modification process and test results have guiding significance for improving the surface insulation performance of epoxy insulators. In this paper, the SnO2/ER composite coating material was prepared by fluorinating nano‐SnO2 powder. It was coated on the surface of Al2O3/ER composite sample by a spin coater, and its flashover voltage was tested. The experimental results show that the flashover voltage increases by 9% after coating treatment, and the flashover voltage increases by 15% after fluorination treatment.