Sony Corporation

Masayoshi Sugiyama

Masakazu Muroyama

Yoshinobu Ninomiya

Akira Hashimoto

Koji Kaneda

A magnetic recording medium comprising a non-magnetic base and a magnetic layer attached thereto consisting essentially of magnetic powders and a binder. Included within the binder are spherical small sized particles of a benzoguanamine-formaldehyde resin or a benzoguanamine-melamine-formaldehyde resin which serve to improve the running characteristics, reduce the friction coefficient, and improve the strength of the layer.

Magnetic recording medium

A magnetic recording medium is disclosed, in which a magnetic layer is formed on one surface of the non-magnetizable substrate and a back coating layer consisting essentially of a binder and a non-magnetizable pigment is formed on the other surface of the substrate. In the back coating layer, more than 80 weight percent of the binder is a polyurethane resin or a polyester resin having hydrophilic polar groups. The back coating layer also contains carbon black for preventing electrostatic charging and pigments with Mohs hardness higher than 5 for improving durability. The carbon black to the pigments weight ratio is set to be in the range of 95:5 to 60:40.

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Miyagi, Japan

Masayoshi Sugiyama