| 摘要 |
PURPOSE:To improve erasing and transfer characteristic by obtaining a magnetic solution through mixing and dispersing of compositions consisting of magnetic oxide iron powder containing Co, binder, additive and solvent etc., applying it on non-magnetic base and drying the surface after orientation. CONSTITUTION:As a needle-shaped magnetic powder, the magnetic iron oxide or chromium dioxide is used. A binder and moreover a lubricant, dispersant, plasticizer, anti-static agent, polishing agent etc. which are added as required are added to such magnetic powder material and these are sufficiently mixed and dispersed with a solvent. Thereby a magnetic paint having the desired composition ratio. The magnetic paint thus obtained is applied to a base consisting of a polyester film. Thereafter, such film is caused to pass in the adequate field using a field orientation apparatus in order to obtain the orientation of magnetic powder in the applied film in one direction before such film is dried. Then, such film is dried and a solvent is separated. Thereafter the surface of magnetic layer of film is subjected to the surface treatment with a supercalender roll. Thereby, a recording medium having excellent erasing and transfer characteristic. |
