| abstract |
An electromagnetic steel sheet which has an insulating coating film having excellent corrosion resistance and punchability without containing Cr can be obtained by applying a process liquid over the surface of the electromagnetic steel sheet and then baking the coated steel sheet. The process liquid contains 1-50 parts by weight in total of one or more crosslinking agents selected from the group consisting of melamine, isocyanates, silane coupling agents and oxadrin per 100 parts by weight of a polysiloxane polymer obtained by copolymerizing a polysiloxane and one ore more resins selected from the group consisting of acrylic resins, styrene resins, vinyl acetate resins, polyester resins, urethane resins, polyethylene resins, polypropylene resins, polyamide resins, polycarbonate resins, phenol resins, alkyd resins and epoxy resins. |