| 摘要 |
PURPOSE:To maintain a lubricating effect for a long period of time by depositing a boron extreme-pressure additive on a thin ferromagnetic metallic film. CONSTITUTION:The thin film 2 consisting of the ferromagnetic metal (e.g.: Co) formed by a thin film vacuum forming technique, etc., and a protective layer 3 contg. the boron extreme-pressure additive are provided on a nonmagnetic substrate. The borate expressed by the formula B(OR)n(OH)3-n (where R is an alkyl, alkenyl, aryl; n is 1, 2, 3) or more preferably the triborate expressed by the formula (RO)3B (e.g.: trioctadecyl borate) is used as the extreme-pressure additive. Other extreme-pressure additives, rust preventive agent, etc., may be incorporated into the layer 3. The lubricating effect is maintained for a long period of time and the magnetic recording medium having a small coefft. of friction, and excellent durability and running property is obtd. according to the above-mentioned constitution. |
