| 摘要 |
PROBLEM TO BE SOLVED: To inhibit the migration of the lubricant in each of the magnetic layers to the adjacent one of the undercoat layers, to surely retain the lubricant in the surface of each of the magnetic layers even at the time of preserving the recording medium for a long period and in particular, to sufficiently improve long-term preservation durability of the medium, in this recording medium consisting of a substrate, two magnetic layers each contg. a lubricant that comprises a fatty acid ester and two nonmagnetic undercoat layers each of which contains carbon black and the lubricant and is interposed between the substrate and one of the magnetic layers. SOLUTION: This recording medium consists of a substrate 1, two magnetic layers 3 placed one by one on both surface sides of the substrate 1 and two nonmagnetic undercoat layer 2 each of which contains carbon black and is interposed between the substrate 1 and one of the magnetic layers 3. Each of the undercoat layers 2 has pores for receiving a lubricant comprising a fatty acid ester and contains the lubricant and each of the magnetic layers 3 also contains the lubricant, wherein the total content of the lubricant comprising a fatty acid ester in each of the undercoat layers 2 and each of the magnetic layers 3 is >=30mg/cm<3> expressed in terms of concn. of the lubricant. |
