Insulating coating compositions applied on electrical steel sheets
AssigneeNippon Steel Corporation
InventorsYoshitaka Hiromae, Kazuo Nakamura, Toshiya Wada, Hirotada Katoh
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Abstract
A coating composition including inorganic compounds dispersed in an organic material capable upon exposure to UV rays or electron beams of producing an adherent insulating film of high dielectric properties on the surfaces of electro-sheets of ferrous material. The coated electro-sheets are annealed after the forming, for example, cutting or punching operation in order to remove thereby imparted stresses without impairing the dielectric properties.
Claims6
An electrical steel sheet coated with an insulating coating film said film having a thickness less than 10 microns and comprising 40 to 70 percent by weight of an organic polymeric material curable by ultraviolet rays or electron beam and 30 to 60 percent by weight of an inorganic compound selected from the group consisting of silicates having a hardness in Mohs scale of not higher than 5 and 1 to 50 percent by weight based on the total weight of the inorganic compound of a compound selected from the group consisting of boric acids and borates.
Dependencies are inferred from the claim text.