MAGNETIC RECORDING MEDIUM

摘要

PURPOSE:To obtain a magnetic recording medium which has the improved surface roughness and wear resistance and has excellent running stability and electromagnetic conversion characteristic after running for a long period by providing a back coat layer contg. Si3N4 powder on a substrate surface on the side opposite from a magnetic layer. CONSTITUTION:The back coat layer formed by incorporating the Si3N4 powder having <=2.0mu average grain size alone or together with other inorg. fillers such as CaCO3 and BaSO4 into a binder resin in such a manner that the Si3N4 powder is incorporated at >=5wt% by the total weight of the inorg. filler is provided on the surface of the non-magnetic substrate on the side opposite from the surface on which the magnetic layer is formed. The surface roughness of the back coat layer is thus made adequate and the running stability and wear resistance are improved. The magnetic recording medium having the excellent electromagnetic converting characteristic after running for a long period and a less decrease in S/N is obtd.