| 摘要 |
PURPOSE:To improve the dispersibility, packing property, etc., of magnetic powder by using a vinyl chloride-vinyl acetate copolymer having groups and a specific polyurethane prepolymer in combination as binder components for a magnetic layer. CONSTITUTION:As binder components for a magnetic layer, a vinyl chloride- vinyl acetate copolymer having epoxy groups and a polyurethane prepolymer having <=10,000 molecular weight are used. The weight ratio of said copolymer to prepolymer is favorably 8:2-4:6. Further, amine and amide such as ethylene diamine and dicyandiamide may be used as binder components to further improve the heat resistance of the magnetic layer. |
