| 摘要 |
PURPOSE:To obtain excellent durability and a high S/N characteristic by providing a magnetic layer via an undercoating layer for adhesion on a base and setting the ratio between ferromagnetic powder and binder resin component in the magnetic layer and the thickness of the magnetic layer in specific ranges. CONSTITUTION:The thickness of a magnetic coating film is decreases while the adequeately high packing of magnetic powder is realized in this invention. The ferromagnetic powder may be oxide powder and metallic powder. The combination of two or three components among vinyl chloride/vinyl acetate copolymer, poly acrylonitrile, etc. is usable for the binder resin component. The magnetic powder and the binder resin component are compounded to 6/1-9/1 by weight in the stage of preparing the magnetic coating. The thickness of the magnetic layer is so adjusted that the magnetic layer has 1.0-2.5mum thickness after surface preparation for the purpose of having the smoother surface. A polyurethance resin, polyester resin, etc. which are cured by polyisocyanate are usable for the binder as the undercoating layer. The thickness is 0.10.5mum and is usually enough with around 0.3mum. |
