| 摘要 |
PURPOSE:To improve lubricity and wear resistance of a magnetic layer by using hydroxyalkyl ester of a specific fatty acid as a lubricating agent. CONSTITUTION:A magnetic recording medium holds the hydroxyalkyl ester of the fatty acid expressed by the formula I . The sum of the number of carbon atoms of R and the number of carbon atoms of the hydroxylalkyl group in the formula I is more particularly preferably >=10. If <10, the lubricating effect is poor. The amt. of the hydroxylalkyl ester of the fatty acid to be added is made 0.2-4wt% by the weight of magnetic powder in the case of incorporating the same into a magnetic layer and 0.2-20wt% by the weight of a binder in the case of incorporating the same into a back coating layer. The top coating layer consisting of the above-mentioned lubricating agent is made 1-1,000mg/m<2> at the amt. of coating in the case of forming the top coating layer or coating layer consisting of said lubricating agent by coating. The hydroxyalkyl ester of the fatty acid is obtd. by the esterification reaction of the fatty acid and alkylene glycol as shown by the formula II. |
