Matsushita Electric Industrial Co., Ltd.

Tetuo Fuchi

Yukihiro Shimasaki

Fumio Echigo

Mikio Murai

Yukikazu Ohchi

Kazunori Kubota

Kenji Kuwahara

Kiyoshi Kobata

Takumi Haneda

Hirofumi Ito

A lubricant composition having excellent lubricity and comprising at least one compound selected among fluorine compounds each having a perfluoroalkyl or perfluoroether group and an alkyl or alkenyl group in the molecule and at least one compound selected among fluorine compounds each having a perfluoropolyether group in the molecule; and a magnetic recording medium excellent in running durability and still durability and comprising a nonmagnetic substrate (1) and, formed thereon in this order, a ferromagnetic thin metal film (2), a carbon film (3), and a lubricant layer (4), wherein the lubricant layer (4) contains the lubricant composition.

Lubricant composition magnetic recording medium, and process for producing magnetic recording medium

The present invention provides a thin multilayer magnetic recording medium having improved electromagnetic conversion property and durability, comprising coating layers of a lower non-magnetic layer and an upper magnetic layer. The non-magnetic layer of this magnetic recording medium comprises a non-magnetic needle body having an average major axis length of 0.25 to 1.0 .mu.m and an average minor axis length of 0.005 to 0.0151 .mu.m, a first binding resin having a glass transition temperature (Tg.sub.1) of 30 to 50.degree. C., and fatty acid ester. The content of the first binding resin is 15 to 30 wt % with respect to the non-magnetic needle body. The content of the fatty acid ester is 2 to 15 wt % with respect to the first binding resin. The magnetic layer having a dry thickness of 0.5 .mu.m or less comprises ferromagnetic powder and a second binding resin having a glass transition temperature (Tg.sub.2) of 40 to 70.degree. C. Tg.sub.1 is at least 5.degree. C. lower than Tg.sub.2, and the entire thickness comprising the layers and the film is 12 .mu.m or less.

Magnetic recording medium

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Osaka, Japan

Tetuo Fuchi