| abstract |
The insulating film comprised mainly of phosphate or chromate is improved in its insulation property required for the laminated core e.g., a transformer, the blanking property required for manufacturing the core sections from the electrical steel sheet, and the lamination weldability. The organic resin particles used for controlling the surface roughness of the film are preliminarily treated with adisper- sion improver, and then added to the emulsion resin, which Is then mixed with the phosphate or chromate. |