| 摘要 |
PURPOSE: To obtain a magnetic recording medium having superior durability even in an environment at high humidity by imparting ruggedness having two kinds of heights to the surface of a protective layer. CONSTITUTION: A Cr layer of 800Åthickness as an underlayer 2, a magnetic layer 3, an Si layer of 50Åthickness as a 1st protective layer 4, a protective layer 5 and a lubricative layer 9 are successively formed on a nonmagnetic substrate 1. The protective layer 5 consists of a metal oxide film 6 using Si oxide as the metal oxide and having 200Åthickness and two groups of particles different from each other in average particle diameter and dispersed in the oxide film 6. The groups of particles are a group 7 of silica particles having 100Åaverage particle diameter (the max. and min. particle diameters:±30Å) and a group 8 of silica particles having 350Åaverage particle diameter (the max. and min. particle diameters:±50Å). Since the surface of the resultant magnetic recording medium has ruggedness due to the groups 7, 8 of particles, the medium has superior durability even in an environment at high humidity, the interval between a magnetic head and the surface of the medium under rotation can be shortened and high recording density is attained.
|
