| 摘要 |
PURPOSE:To improve reproduced RF output, traveling durability, still durability and drop-out increase by incorporating respective specific carbon black and fatty acid ester into a 1st magnetic layer of a lower layer and a 2nd magnetic layer of an upper layer. CONSTITUTION:At least >=2 layers of the magnetic layers contg. ferromagnetic powder and binder are provided on the surface of a nonmagnetic base and the carbon black having 100 to 200ml/100g DBP oil absorption and the fatty acid ester expressed by formula I are incorporated into the 1st magnetic layer of the lower layer. The carbon black having 80ml/100g DBP oil absorption and the fatty acid ester expressed by formula II are incorporated into the 2nd magnetic layer of the upper layer. In the formulas I, II, R1, R2 denote 11 to 21C satd. or unsatd. hydrocarbon group; R2, R5 denote 1 to 18C satd. or unsat d. hydrocarbon group; R4 denotes 2 to 4C satd. bivalent hydrocarbon group; (n) denotes 1 to 7. The traveling durability, drop-out increase and reproduced RF output are improved in this way. |
