| 摘要 |
PURPOSE:To improve the dispersibility, packing property, etc., of magnetic powder by using a vinyl chloride-vinyl acetate copolymer having epoxy groups and a vinylidene chloride-acrylonitrile copolymer 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 vinylidene chloride-acrylonitrile copolymer are contained. The weight ratio of both said copolymers is 9:1-1:9, and favorably 7:3-3:7. Further, an isocyanate compound having low molecular weight such as 2,4-tolylenediisocyanate is further used as a binder component in combination with a polyurethane prepolymer having hydroxyl groups, etc., further improving the heat resistance. |
