| 摘要 |
PURPOSE:To obtain a back coat layer which obviates the chipping of a back surface during continuous running, has a good electromagnetic conversion characteristic and does not induce an edge damage during loading and unloading by constituting the back coat layer of a prescribed binder contg. prescribed nonmagnetic powder and specific carbon black. CONSTITUTION:The nonmagnetic powder and the carbon black having 300-700m<2>/g specific surface area and <=6pH is incorporated into the back coat layer of a magnetic recording medium having a magnetic layer on one side face of a substrate and the back coat layer on the other side face. The nonmagnetic powder is preferably one of Ti2O3, ZnO, MgO, SiO, BaSO4, BaCO3, Mg(OH)2, Al(OH)3, and org. powder. The binder contains a cellulosic resin and polyurethane resin and is added with an isocyanate. The content of the carbon black is 1-60%, more preferably 10-55% of the weight of the total solid content.
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