PURPOSE: To obtain a lubricant for a magnetic recording medium having a semipermanent life by using a specified polyether contg. halogen and having repeating units as a principal component.
CONSTITUTION: A straight chain polyether contg. halogen is utilized as a lubricant. The polyether has lower vapor pressure than a branched perfluoropolyether and can be used nearly semipermanently. Especially a straight chain polyether contg. both Cl and F in the molecule such as F-(CCl2CF2O)n-CCl2CF3 or F-(CHClCF2CF2O)n-CHClCF3 has very low vapor pressure and also has high extreme-pressure and a low coefft. of friction because of the specific structure contg. both Cl and F in the molecule. The polyether is very effective in lubricating the surface of the film of a magnetic body.
SHIMAZAKI SHUHEI
TOTSUKA TAKASHI
