| 摘要 |
PURPOSE:To obtain a magnetic tape, etc. containing a metallic magnetic layer having improved corrosion resistance, by exposing a ferromagnetic thin film formed on a polymer film substrate into an oxidative glow discharge atmosphere while holding the thin film under an AC-erased state and therefore forming a uniform corrosion resistant oxide film. CONSTITUTION:An original plate formed by vapor-depositing a magnetic layer on a polymer film substrate 1, for example, is shifted along a rotary roll 2 for production of a recording medium (disk, tape, etc.) using a metallic ferromagnetic thin film of Co, etc. to a magnetic layer. In this case, glow processing electrodes 3 and 4 are alternately insulated and connected so as to obtain the same potential. Then the electric power is supplied from a power supply 5, and a discharge gas of O2, etc. is introduced to oxidize the surface of the magnetic layer. An AC magnetic field of a commercial frequency of a frequency close to said commercial frequency is applied to the substrate when it comes out of a feed-out roll 6 by means of an electomagnetic 8. Thus it is possible to oxidize evenly the surface of the magnetic layer to improve the corrosion resistance as well as to eliminate clogging of the head. Furthermore, the output is never lowered since no special protecting film, etc. is applied for a magnetic tape, etc. |
