| 摘要 |
PROBLEM TO BE SOLVED: To improve storage property with weather resistance and durability in still operation by forming on a nonmagnetic substrate, a ferromagnetic metal thin film, carbon film and lubricant layer containing a compd. having perfluoroalkyl groups or perfluoropolyether groups and aliphatic alkyl groups or aliphatic alkenyl groups and a compd. having perfluoroalkyl groups and aliphatic alkyl groups. SOLUTION: The lubricant layer contains at least one compd. of compds. (A) expressed by formula I and compds.(B) expressed by formula II, and a compd. (C) expressed by formula III. In formulae, R1 , R3 are aliphatic alkyl groups or aliphatic alkenyl groups. R2 , R4 are perfluoroalkyl groups or perfluoropolyether groups, R5 is -O- or -S-; a and c are integers 0 to 20, b and d are 0 or 1. The mixing ratio of at least one of component (A) and component (B) to the component (C) is preferably 7:3 to 4:6 molar ratio. The lubricant layer is formed by wet coating method such as bar coating and gravure coating. |
