Sughrue, Mion, Zinn, Macpeak and Seas
Magnetic recording medium
 A magnetic recording medium which comprises a non-magnetic support having on the surface side thereof a magnetic recording layer and on the opposite side thereof a backing layer having a thickness of 2 .mu.m or less, which contains carbon black and a binder and optionally, an inorganic powder, in which the backing layer contains at least two kinds of carbon black, one being fine-grained carbon black having a mean grain size of 10 to 30 m.mu. and the other being coarse-grained carbon black having a mean grain size of 150 to 500 m.mu. such that the weight ratio (P/B) of the total amount of carbon black and inorganic powder (P) to binder (B) is from about 1/0.5 to 1/3.5. The recording medium described provided smooth and stable tape-running for an extended period and a high S/N ratio. 
Fuji Photo Film Co., Ltd.
G Y Y Y G Y Y
G11B Y10T Y10S Y10T G11B Y10T Y10T
inventional additional additional additional inventional additional additional
Masaaki Masahiro Toshimitu Kenichi Takahito
Fujiyama Utumi Okutu Masuyama Miyoshi