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AssigneeFuji Photo Film Co., Ltd.
InventorsKatsumi Ryoke, Katsuhiko Meguro, Hiroaki Doushita, Masaki Suzuki, Toshiyuki Kitahara, Masami Sato
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A magnetic recording medium comprises a magnetic layer containing a ferromagnetic powder, a binder and an abrasive material having a Mohs hardness of 8 or more on a non-magnetic support, wherein the average protrusion height, which represents the length between the central line of the surface roughness of the sectional curve of the magnetic layer and the upper end of the abrasive material existing (i) above the central line of the surface roughness of the magnetic layer and (ii) in the surface layer of the magnetic layer, is 15 nm or less. A process for preparing the magnetic recording medium comprises coating on a non-magnetic support a magnetic layer containing a ferromagnetic powder, a binder and an abrasive material having a Mohs hardness of 8 or more, and then polishing the surface of the magnetic layer with an abrasive tape, wherein as the abrasive tape there is used one containing at least one abrasive material having a higher Mohs hardness than the abrasive material to be incorporated in the magnetic layer.
A magnetic recording medium comprising a magnetic layer containing a ferromagnetic powder, a binder and an abrasive material having a Mohs hardness of 8 or more on a non-magnetic support, wherein the average protrusion height, which represents the length between the central line of the surface roughness of the sectional curve of the magnetic layer and the upper end of the abrasive material existing (i) above the central line of the surface roughness of the magnetic layer and (ii) in the surface of the magnetic layer, is 12 nm or less, and wherein the surface of the magnetic layer has been polished with an abrasive tape which comprises an abrasive material having a higher Mohs hardness than the abrasive material incorporated in the magnetic material.
Dependencies are inferred from the claim text.