| 摘要 |
<p>PROBLEM TO BE SOLVED: To obtain a surface treating agent excellent in film performance and containing no chromium compound by containing one or more kinds of primary phosphates of Al, Mg, Ca and organic acid salts of Ca, Mn, Fe, Mg, Zn, Co, Ni, Cu, B, Al in specific of them based on colloidal silica. SOLUTION: This surface treating agent contains 100 pts. wt. expressed in tems of solid of the primary phosphates of Al, Mg, Ca and 0.1-5 pts.wt. as the metallic element of the organic acid salt of Ca, Mn, Fe, Mg, Zn, Co, Ni, Cu, B, Al based on 35-100 pts.wt. of the colloidal silica. The organic acid salt is desirable to be formate, acetate, oxalate, tartrate or the like. A silicon steel slab is hot-rolled and two or more of cold-rollings after one time annealing or inserting intermediate annealing, are applied to form the steel sheet to the finish-thickness, and a decarbourize-annealing is applied, and after coating annealing separator, the last finish annealing is applied, and successively, the surface treating agent as an insulating film agent is coated, and a baking treatment at >=350 deg.C and a heat flattening are applied. Environmental problem is dissolved and also, the defective problems to a wet-absorbing resistance and also, annealing resistance are dissolved.</p> |
