INSULATION FILM-EQUIPPED ELECTROMAGNETIC STEEL SHEET AND MANUFACTURING METHOD THEREFOR, TRANSFORMER IRON CORE FORMED BY USING ELECTROMAGNETIC STEEL SHEET, TRANSFORMER, AND METHOD FOR REDUCING DIELECTRIC LOSS OF TRANSFORMER

摘要

Provided is an insulation film-equipped electromagnetic steel sheet in which, when being used for an iron core of a transformer, dielectric loss of the transformer can be reduced. This insulation film-equipped electromagnetic steel sheet has, on at least one of the surfaces of the electromagnetic steel sheet, an insulation film having a dielectric constant at 1000Hz of 15.0 or less and a dielectric loss tangent of 20.0 or less.