Fuji Photo Film Company, Limited

Masahiro Utsumi

Eiichi Tadokoro

Nobutaka Yamaguchi

Shinobu Iida

Masaaki Fujiyama

Katsumi Ryoke

Masami Suzuki

Toshimitu Okutu

Kenichi Masuyama

Sugihiko Tada

Norio Nasu

A magnetic recording medium comprised of a nonmagnetic support base having a magnetic recording layer on one surface thereof and a backing layer on the other surface thereof is disclosed. The backing layer is comprised of (1) carbon black having a particle size in the range of 10 to 150 m.mu., (2) graphite having a particle size of 3.mu. or less, and (3) a curing agent. By utilizing this particular backing layer the resulting recording medium has improved durability with respect to the backing layer and shows a decreased in the number of dropouts and scratches during use.

Magnetic recording medium

A magnetic recording material comprised of a non-magnetic support base having provided thereon a magnetic recording layer on one side and the back layer on the other side is disclosed. The magnetic recording layer is comprised of ferromagnetic particles dispersed in a binder in combination with carbon black particles having an average primary particle size of 30 .mu.m or less. The back layer is comprised of a binder having dispersed therein carbon black having an average primary particle size in the range of 50 to 150 m.mu.. The magnetic recording material has improved electromagnetic properties and improved durability, particularly with respect to video S/N and dropout.

Magnetic recording materials

A method for producing a magnetic recording medium is disclosed. The method involves providing a ferromagnetic coating layer on a non-magnetic support base to produce a coated base. The coated base is then subjected to an atmosphere having a RH of 60% or more, prior to or during a subsequent calendering treatment. The recording medium produced has excellent surface smoothness and improved electromagnetic properties. The method is advantageous in that a substantially long period of time may pass between the coating of the ferromagnetic layer on the support and the calendering treatment without having undesirable effects on the magnetic recording medium produced.

Method of preparing a magnetic recording medium with a calendering

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Kanagawa, Japan

Masahiro Utsumi