| 摘要 |
PURPOSE:To enhance effect as a lubricant and to ensure excellent CSS resistance. CONSTITUTION:A magnetic layer made of a thin ferromagnetic metal film is formed on a rigid substrate and a lubricant layer is formed on the surface of the magnetic layer with perfluoro-polyether having >=2,500 average mol.wt. as a lubricant. This perfluoro-polyether is prepd. by purifying a stock soln. of commercially available perfluoro-polyether by solvent extraction with at least one among ethnaol, methanol, butanol, isopropanol, acetone, methyl ethyl ketone and acetic acid. |
