COATING SOLUTION FOR FORMING INSULATING FILM WITH EXCELLENT CORROSION RESISTANCE PROPERTY AND FILM CLOSE ADHESION PROPERTY WITHOUT CR AND A METHOD FOR MAKING THE INSULATION FILM ON NON-ORIENTED ELECTRICAL STEEL SHEET BY USING IT

摘要

A chrome-free coating composition for forming a dielectric film is provided to allow formation of an eco-friendly coating layer on a non-oriented electric steel sheet, and to obtain improved anticorrosive property and adhesion of a coating layer after stress relief annealing(SRA). A chrome-free coating composition for forming a dielectric film having excellent anticorrosive property and adhesion after SRA comprises: a phosphate solution containing aluminum phosphate and zinc phosphate in a ratio of 1:1 and having a solid content of 60 wt%; and based on 100g of the phosphate solution, 0.5-5g of a solid material containing cobalt hydroxide and strontium hydroxide in a ratio of 1:1; 100-300g of a polyester emulsion resin having a solid content of 20 wt%; 3-10 g of aluminum silicate having a solid content of 20%; and 0.1-6g of a Ti-based chelating agent.