New casting compositions of liquid rubbers for electrical insulation

A new class of castable rubber (MELQID) consisting of polyolefin polyol and modified polyisocyanate for electrical insulation has been developed. The properties of MELQID and its applicability to electrical apparatus, especially to current transformers , were studied. MELQID has good casting processability, thermal stability, water resistance, mechanical and electrical properties. The current transformers encapsulated with the modified MELQID are superior to those molded with solid EPT rubber in size, weight and some properties.