1. Field of the Invention
The present invention relates to a magnetic recording medium and to a method of manufacturing the same. More particularly, the present invention relates to a high-density recording magnetic recording medium with good electromagnetic characteristics, and to a method of manufacturing the same.
2. Discussion of the Background
In recent years, as microcomputers, personal computers, and office computers such as work stations have become increasingly widespread, considerable research has been conducted into external storage media in the form of magnetic tapes for recording computer data (known as “backup tapes”).
Products in the form of data backup tapes with high recording capacity have been developed in response to an increase in the diversity and quantity of information being recorded. To achieve tapes of high recording capacity, the spacing between the magnetic layer and the magnetic head should be reduced. For example, when large protrusions and indentations are present on the surface of the magnetic layer, output drops due to spacing loss, resulting in compromised electromagnetic characteristics such as heightened dropout, an increased error rate, and a drop in the S/N. Accordingly, the magnetic recording layer surface of a data backup tape of high recording capacity is required to be extremely smooth to achieve good electromagnetic characteristics. For example, as described in Japanese Patent No. 3,698,540 or English language family member U.S. Pat. No. 6,127,039, which are expressly incorporated herein by reference in their entirety, the use of a nonmagnetic layer in the form of a radiation-cured layer positioned beneath the magnetic layer is a known means of increasing the surface smoothness of the magnetic layer.
As described above, enhancing a surface smoothness of the magnetic layer is an effective means for improving electromagnetic characteristics. However, on the other hand, the smoother the magnetic layer surface is, the greater the coefficient of friction between the magnetic layer surface and a head becomes. This may cause generation of shavings from the magnetic layer surface during repeated running (pieces of damaged coating). The pieces of damaged coating may cause decreased output because these pieces adhere to the head. As a result, it becomes difficult to maintain good electromagnetic characteristics for an extended period.