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 is disclosed. The backing layer contains carbon black and a binder and has a thickness of 2 .mu.m or less. The carbon black is composed of fine-grained carbon black having a mean grain size of 10 to 30 m.mu. and coarse-grained carbon black having a mean grain size of 100 to 150 m.mu.. In the backing layer the ratio of the content of carbon black to the binder ranges from 1:0.5 to 1:3.5 by weight. 
Fuji Photo Film Co., Ltd.
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Masahiro Takahito Masaaki Toshimitu Kenichi
Utumi Miyoshi Fujiyama Okutu Masuyama