| 摘要 |
PROBLEM TO BE SOLVED: To enable an excellent traveling property and durability by holding a lubricant mixture composed of an ester compd. of perfluoropolyether having a hydroxyl group at a terminal and long-chain carboxylic acid, and perfluoroalkyl carboxylate deriv. on the outermost layer. SOLUTION: The lubricant contg. the ester compd. of the perfluoropolyether having the hydroxyl group at the terminal expressed by formula I and the long-chain carboxylic acid and the perfluoroalkyl carboxylate deriv. expressed by formula II is used. In the formula I, Rf1 denotes a perfluoropolyether chain and R1 denotes a hydrocarbon group or fluorohydrocarbon group. In the formula II, R' denotes 7-21C alkyl group; (m), (n) denote an integer of m+m>=8. A magnetic layer 2 consisting of a ferromagnetic thin film of Fe, Co, Ni, etc., is formed on a nonmagnetic base 1 and the lubricant is held in a protective film 3 which is the outermost layer and consists of SiO2 , silicon nitride, carbon nitride, etc. |
