Coating agent for electrical steel sheet, manufacturing method therefor and electrical steel sheet coating method using same

A method of manufacturing a coating agent for an electrical steel sheet comprising:

• preparing a metal phosphate derivative;
• and
• adding silica and chromium oxide to a solution including the metal phosphate derivative;
• wherein the metal phosphate derivative is prepared by a condensation reaction of metal phosphate and boric acid (H3BO3).

An electrical steel sheet comprising:

• a base steel sheet and a coating layer formed on the base steel sheet,
• wherein the coating layer includes a metal phosphate derivative, silica, and chromium oxide,
• the metal phosphate derivative is a single material of a magnesium phosphate derivative or a mixed material of an aluminum phosphate derivative and a magnesium phosphate derivative, and
• the amount of aluminum phosphate derivative is less than or equal to 10 wt % (not including 0%) in the mixed material.