Victor Company of Japan, Limited

Hiroshi Togashi

Yukio Matsumoto

Kumiko Ojima

Hiroshi Ogino

Kuniharu Fujiki

Tsutomu Yashiro

Mutsumu Kurihara

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 has a magnetic layer which is made of a magnetic material constituted by a mixture of hexagonal system ferrite magnetic particles and acicular ferromagnetic particles.

Magnetic recording medium

A magnetic recording medium comprising a nonmagnetic support, and a magnetic recording layer formed on said support. The magnetic recording layer comprises a magnetic powder and an abrasive powder dispersed in a resin binder. The abrasive powder has a coating of an isocyanate compound having at least two isocyanate groups in one molecule thereof and is used in an amount of from 0.5 to 20 parts by weight per 100 parts by weight of the magnetic powder.

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Yamagata, Japan

Hiroshi Togashi