Magnetic recording medium
AssigneeFuji Photo Film Co., Ltd.
InventorsNobutaka Yamaguchi, Shinobu Iida, Toshimitu Okutu, Takahito Miyoshi, Eiichi Tadokoro, Masaaki Fujiyama
Life of this patent
Estimating the term…
Abstract
A magnetic recording medium is disclosed. The medium is comprised of a non-magnetic support having coated thereon a magnetic recording layer and a backing layer on the surface opposite the magnetic recording layer. The backing layer contains carbon black and the surface treated calcium carbonate dispersed in a binder. The calcium carbonate is surface treated so as to make the particles hydrophobic. Including the carbon black and the calcium carbonate in the backing layer provides a recording medium with improved durability and a reduced amount of drop out.
Claims49
A magnetic recording medium comprising a nonmagnetic supporting having coated thereon a magnetic recording layer comprising a ferromagnetic powder and a binder and a backing layer on the surface opposite to the magnetic recording layer, said backing layer containing (1) carbon black having an average particle size in the range of about 10 m.mu. to about 150 m.mu. and (2) surface treated hydrophobic calcium carbonate.
A magnetic recording medium as claimed in claim 2, wherein the carbon black has an average has an average particle size in the range of 30 m.mu. to 120 m.mu..
Dependencies are inferred from the claim text.