Electromagnetic steel sheet coated with insulating film, process for producing same, and coating material for forming insulating film

A coating material for forming an insulation coating, containing, in addition to a solvent:

• an aqueous carboxy group-containing resin as component (A) in an amount of 100 parts by mass in terms of solid content;
• an aluminum-containing oxide as component (B) in an amount of more than 40 parts by mass but less than 300 parts by mass in terms of solid content, based on the component (A) present in an amount of 100 parts by mass in terms of solid content;
• and
• at least one crosslinking agent as component (C) selected from the group consisting of melamine, isocyanate and oxazoline, in an amount of not less than 100 parts by mass but less than 300 parts by mass in terms of solid content, based on the component (A) present in an amount of 100 parts by mass in terms of solid content.

A manufacturing method for an electrical steel sheet with an insulation coating, comprising forming an insulation coating on one or both of sides of an electrical steel sheet by applying thereto a coating material containing, in addition to a solvent:

• an aqueous carboxy group-containing resin as component (A) in an amount of 100 parts by mass in terms of solid content;
• an aluminum-containing oxide as component (B) in an amount of more than 40 parts by mass but less than 300 parts by mass in terms of solid content, based on the component (A) present in an amount of 100 parts by mass in terms of solid content;
• and
• at least one crosslinking agent as component (C) selected from the group consisting of melamine, isocyanate and oxazoline, in an amount of not less than 100 parts by mass but less than 300 parts by mass in terms of solid content, based on the component (A) present in an amount of 100 parts by mass in terms of solid content.