Resin based reactive compounds used for electrical insulation - Part 3: Specifications for individual materials - Sheet 5: Unsaturated polyester based impregnating resins
This sheet 5 of IEC 60455-3 gives the requirements for unsaturated polyester based impregnating resins, and includes requirements for certain properties at elevated temperature.
Materials which conform to this specification meet established levels of performance. However, the selection of a material by a user for a specific application should be based on the actual requirements necessary for adequate performance in that application and not on this specification alone.