| 摘要 |
PROBLEM TO BE SOLVED: To provide an electromagnetic steel sheet having an insulating coating excellent in insulation properties, tension pad resistance and punchability even without containing chromium in the insulation film.SOLUTION: An electromagnetic steel sheet having an insulation film of the present invention comprises an insulation film formed by applying a surface treatment agent containing: at least one selected from trialkoxysilane and dialkoxysilane with a substituent connected to Si comprising solely of at least one nonreactive substituent selected from hydrogen, alkyl group and phenyl group and tetraalkoxysilane (A); a silane coupling agent (B); silica particle (C); and water on at least one surface of the electromagnetic steel sheet, followed by drying, in which the content of the silica particle in the insulation film is 10 to 60% based on Si and the average maximum diameter of the particle aggregate on the surface of the insulation film is 3.50 μm or less. |
