| 摘要 |
PROBLEM TO BE SOLVED: To improve travelling durability of a recording medium and to increase the practical reliability by forming a magnetic layer consisting of a ferromagnetic metal thin film on one face of a nonmagnetic substrate, forming a back coating layer consisting of a metal thin film on the other face of the substrate, forming a lubricant layer on the opposite face of the back coating layer to the nonmagnetic substrate, and incorporating one or more kinds of fluorine-contg. carboxylic acids into the lubricant layer. SOLUTION: The lubricant contains fluorine-contg. carboxylic acids expressed by formula I. In the formula, R1 is an aliphatic alkyl group or aliphatic alkenyl group, R2 is a fluoroalkyl group, fluoroether group or fluoropolyether group, (a) is 0 or 1, and (b) is 0 to 20. Practically, a compd. expressed by formula II or the like can be used. The lubricant layer on the back coat side of the magnetic recording medium may be formed from only the fluorine-contg. carboxylic acids of formula I, or other lubricants, rust preventive, extreme pressure additive or the like may be mixed. The fluorine-contg. carboxylic acids are preferably incorporated by >=40 wt.% of the total mixture, and the amt. of the acids is preferably 0.05 to 100 mg per 1 m2 of the surface of the lubricant layer. |
