| 摘要 |
PURPOSE: An inorganic coating composition for forming an insulation film having superior roll coating property and film characteristics, and a method for forming an insulating film on non-oriented magnetic steel sheet using the inorganic coating composition are provided. CONSTITUTION: The inorganic coating composition for forming an insulating film having superior insulation coating characteristics after stress relief annealing is characterized in that the inorganic coating composition is prepared by adding 75 to 143 g of kaolin clay, 1.7 to 5.3 g of wetting and dispersing agent, 0.3 to 1.4 g of non-silicon based antifoaming agent and 8 to 22 g of saturated sodium molybdate solution per 100 g of phosphoric acid inside the aqueous solution to the mixture so that the additives are mixed with the mixture after preparing a mixture by adding 6 to 18 g of colloidal silica per 100 g of phosphoric acid to phosphate aqueous solution. The method for forming an insulation film on non-oriented magnetic steel sheet comprises the processes of coating the coating composition on the surface of the non-oriented magnetic steel sheet so that thickness of dried coating film is in the range of 0.8 to 2.8 μm per one surface of the steel sheet, wherein the coating composition is prepared by adding 75 to 143 g of kaolin clay, 1.7 to 5.3 g of wetting and dispersing agent, 0.3 to 1.4 g of non-silicon based antifoaming agent and 8 to 22 g of saturated sodium molybdate solution per 100 g of phosphoric acid inside the aqueous solution to the mixture so that the additives are mixed with the mixture after preparing a mixture by adding 6 to 18 g of colloidal silica per 100 g of phosphoric acid to phosphate aqueous solution; and heat treating the coating composition coated on the surface of the non-oriented magnetic steel sheet at a temperature of 450 to 900 deg.C for 8 to 50 seconds. |
