| 摘要 |
PURPOSE:To improve an electromagnetic conversion characteristic, magnetic characteristics and durability such as mu value under repetitive running under low temp. and low humidity conditions and mu value under low humidity conditions by incorporating a compd. of one kind among specific fatty acid deriv. compds. and long chain fatty acid as a lubricating agent into a titled medium. CONSTITUTION:The compd. of at least one kind among the fatty acid deriv. compds. expressed by the formula and the long chain fatty acid are incorporated as the lubricating agent into the medium. In the formula, R denotes a hydrocarbon group of 11-21 C, X denotes hydrogen or methyl group, R' denotes a hydrocarbon group of 1-8 C, n denotes 2-20 integer. The amt. of the fatty acid deriv. compd. and along chain fatty acid to be added at the time of using the same by adding the same internally to a magnetic coating liquid is specified to 0.05-6wt% by the weight of the fine ferromagnetic powder and the ratio (by weight) of using the fatty acid deriv. compd. and the long chain fatty acid is confined to 70:30-30:70. The recording medium which has the excellent electromagnetic conversion characteristic, obviates the clogging of a video head under the low humidity, is no longer increased in the coefft. of friction even after repetitive running and is extremely low in the increase of the mu value is thereby obtd. |
