| 摘要 |
PURPOSE:To improve runnability, running durability, wear resistance, antistatic characteristic and electromagnetic conversion characteristic by coating a specific back coating material essentially consisting of a polyester resin on the rear face of a PET film on the front face of which a magnetic coated film is formed. CONSTITUTION:The back coating layer is formed on the rear face of the PET film formed with the magnetic coated film on the front face by coating the back coating material prepd. by dispersing carbon black and inorg. powder into the binder essentially consisting of the polyester resin. The above-mentioned carbon black powder is preferably the powder the surface of which is preliminarily subjected to an oxidation treatment. The inorg. powder on which a silicon film is formed may be used as well. Such carbon black has good dispersibility and enhances the wear resistance of the back coating layer and therefore, the packing degree of the magnetic powder is increased without necessitating incorporation of the carbon black into the magnetic coated film and the transfer of the back coating layer on the surface of the magnetic coated film at the time of lap winding is prevented. The magnetic recording medium having the good antistatic characteristic, wear resistance, running durability and electromagnetic characteristics is thereby obtd.
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