| 摘要 |
PURPOSE:To form an insulation coating film superior in punchability and weldability by coating a treating liquid in which a polyethylene resin powder suspension is combined with a mixed liquid of dichromate and organic resin emulsion to an electrical steel sheet, and baking said body under a specified condition. CONSTITUTION:Polyethylene powder resins having 5-80mum particle diameter are dispersed into water by using a surfactant. The suspension is combined with the mixed liquid of aqueous dichromate solution, organic resin emulsion of acryl- vinyl acetate, etc. and a reducing agent. The treating liquid is coated on the surface of the electrical steel sheet. In performing the baking successively, the temp. rising rate is controlled under the condition of 2-10 deg.C/s between 110- 150 deg.C steel sheet temp. The temp. is rised successively to finish the baking in 250-350 deg.C temp. range. By this method, insulation coating film superior in sticking property and satisfying both punchability and weldability can be formed on the electrical steel sheet. |
