| 摘要 |
PURPOSE:To eliminate blooming and to improve still durability, powder dislodging, etc. by incorporating >=1 kind of fatty acid ester and >=2 kinds of fatty acids into a prescribed layer such as a magnetic layer thereby providing synergistically the effect thereof as a lubricating agent. CONSTITUTION:At least 2 kinds of fatty acids having a m.p. exceeding 50 deg.C and at least one kind of fatty acid ester are incorporated into the prescribed layer on a base and at least one of said fatty aicd ester consists of the higher fatty acid ester expressed by the general formula: RCOOR' (where, R, R' are an aliphat. group and the carbon atom of R thereof is >=16). The usable fatty acid ester is exemplified by butyl caproate, butyl caprylate, butyl myristate, butyl laurate, etc., among which kind are used and the same time at least one among which having >=16 carbon atom of the above-mentioned R (for example, butyl stearate, propyl stearate) is used. The other fatty acid esters may be added in addition to these esters. |
