Magnetic recording medium
AssigneeFuji Photo Film Co., Ltd.
InventorsKenichi Masuyama, Kazuo Kato, Hiroaki Araki
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AssigneeFuji Photo Film Co., Ltd.
InventorsKenichi Masuyama, Kazuo Kato, Hiroaki Araki
Estimating the term…
A magnetic recording medium having two or more magnetic layers is disclosed, comprising a first magnetic layer and a second magnetic layer which-have been provided in this order on a surface of a nonmagnetic support, and which contain ferromagnetic particles and a binder, wherein said second magnetic layer (outermost layer) contains nonmagnetic particles having a pH of less than 7, and a Mohs' hardness of 6 or more, in an amount of from 1 to 20 parts by weight, per 100 parts by weight of the ferromagnetic particles in the second magnetic layer, and said first magnetic layer contains nonmagnetic particles having a pH of 7 or more, and a Mohs' hardness of 6 or more, in an amount of from 5 to 50 parts by weight, per 100 parts by weight of the ferromagnetic particles in the first magnetic layer.
A magnetic recording medium comprising a first magnetic layer and a second magnetic layer which have been provided in this order on a surface of a nonmagnetic support, and which contain ferromagnetic particles and a binder, wherein said second magnetic layer contains nonmagnetic particles selected from the group consisting of Cr.sub.2 O.sub.3, .alpha.-Fe.sub.2 O.sub.3, SiC, TiO.sub.2, ZrO.sub.2 and particles obtained by coating nonmagnetic powder particles having a Mohs' hardness of 6 or more with Cr.sub.2 O.sub.3, .alpha.-Fe.sub.2 O.sub.3, SiC or TiO.sub.2, having a pH of less than 7, and a Mohs' hardness of 6 or more, in an amount of from 1 to 20 parts by weight, per 100 parts by weight of the ferromagnetic particles in the second magnetic layer, and said first magnetic layer contains nonmagnetic particles selected from the group consisting of .alpha.-Al.sub.2 O.sub.3, SiO.sub.2 and particles obtained by coating nonmagnetic powder particles having a Mohs' hardness of 6 or more with .alpha.-Al.sub.2 O.sub.3 or SiO.sub.2 having a pH of 7 or more, and a Mohs' hardness of 6 or more, in an amount of from 5 to 50 parts by weight, per 100 parts by weight of the ferromagnetic particles in the first magnetic layer.
Dependencies are inferred from the claim text.