SOLUTION FOR TREATMENT OF INSULATING COATING FILM FOR ORIENTED ELECTROMAGNETIC STEEL SHEET, AND METHOD FOR PRODUCTION OF ORIENTED ELECTROMAGNETIC STEEL SHEET HAVING INSULATING COATING FILM THEREON

摘要

Disclosed is a chromium-free solution for use in the treatment of an insulating coating film for an oriented electromagnetic steel sheet, which contains at least one phosphoric acid salt selected from phosphoric acid salts of Mg, Ca, Ba, Sr, Zn, Al and Mn, and which further contains colloidal silica in an amount of 0.5 to 10 mol in terms of SiO2 content and a titanium chelate compound in an amount of 0.01 to 4.0 mol in terms of Ti content, both relative to 1 mol of PO4 contained in the selected phosphoric acid salt. The solution enables to prevent the decrease in tension and moisture resistance of an insulating coating film which occurs significantly when a chromium-free solution is used for treating the insulating coating film, and enables to produce an oriented electromagnetic steel sheet having excellent insulating coating film properties, i.e., excellent coating film tension, moisture resistance, corrosion resistance and lamination factor.