Method of producing resin and method of producing insulating structure

A method of producing an insulating structure formed on an outer peripheral portion of a conductor, the method comprising:

• a resin production step of producing a resin including a nanofiller;
• and
• a step of impregnating a non-conductive tape-shaped member wound around the outer peripheral portion of the conductor with the resin, wherein
• the resin production step includes:
• a filler mixing step of mixing the nanofiller at a ratio of 15 wt % or more with an epoxy resin to form a mixture;
• a shear mixing step of mixing the mixture to disperse the nanofiller in the mixture by shear mixing;
• a diluent mixing step of mixing a reactive diluent that reduces a viscosity of the epoxy resin, with the mixture after the shear mixing step, and
• a curing agent mixing step of mixing an acid anhydride curing agent with the mixture after the diluent mixing step,
• wherein the resin production step further comprising a dispersiveness evaluation step of evaluating dispersiveness of the nanofiller in the mixture after the diluent mixing step, and
• wherein the curing agent mixing step is performed when dispersiveness of the nanofiller is evaluated to satisfy a predetermined criterion in the dispersiveness evaluation step.