A Method for Preparing High Thermal Resistant Baking Type Insulating Varnish Based on Shellac

Varnishes can be used for coating of coils of electrical motors, transformers etc. Possess high dielectric strength 60-90 kV/mm, resistance to water, transformer oil and tracking, thermal rating (by TGA) 177-179 degree centigrade (approximately). Found satisfactory when applied on 6.6kv 330kw/ 6.6kv 750kw electric motor. Simple method of preparation.