Victor Company of Japan, Limited

Kumiko Ojima

Yukio Matsumoto

Hiroshi Togashi

Hiroshi Ogino

Tsunehide Naruse

A magnetic recording medium comprising a non-magnetic support, a magnetic recording layer formed on one side of the support, and a back coat layer formed on the other side. The back coat layer is formed of a composition which comprises a dispersion, in a resin binder, of carbon black having a pH of 2.0 to 8.5 and a coloring power not less than 90 as determined by the ASTM method. The dispersion may further comprise a specific type of aliphatic acid-modified, fluorinated organosilicone in order to improve the travellability and durability of the medium.

Magnetic recording medium having a back coat layer containing carbon

A magnetic recording medium which comprises a non-magnetic substrate, a magnetic recording layer formed on one side of said substrate, and a back coat layer formed on the other side of the substrate. The back coat layer is made of a composition which comprises particles of carbon black, titanium monoxide or a mixture thereof having an average size not larger than 1 micrometer and a resin binder dispersing the particles therein. The particles are individually precoated with an isocyanate compound. When coated titanium monoxide particles are used singly, non-coated carbon black is effectively used in combination.

Magnetic recording medium having an improved back coat layer

A magnetic recording medium comprises a back coat layer on one side of a non-magnetic support which is opposite to a side on which a magnetic recording layer has been formed. The back coat layer is made of a composition which comprises, in a resin binder, carbon black treated with a fatty acid of the formula, RCOOH, in which R represents a linear saturated or unsaturated hydrocarbon having from 13 to 17 carbon atoms. The medium is particularly suitable for high density recording.

A magnetic recording medium of the type which comprises a non-magnetic substrate and a magnetic recording layer formed on the substrate. The magnetic recording layer is made of a dispersion of magnetic powder in a binder and a lubricant which is a reaction product of a monobasic fatty acid and a monohydric alcohol in a molar ratio of 1:0.3 to 1:0.8.

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Mito, Japan

Kumiko Ojima