| 摘要 |
PURPOSE:To improve durability, wear resistance, weatherability, corrosion resistance, etc., and to prevent the attraction to a head by providing a thin magnetic metallic layer and carbon protective film on a nonmagnetic substrate and providing a specific top coat layer contg. a graft polymer of fluorine as a lubricating agent on said protective layer. CONSTITUTION:This magnetic recording medium 1 is provided with an underlying layer 3, nonmagnetic metallic intermediate layer 4, thin magnetic metallic film layer 5 and nonmagnetic metallic protective film 6 on the nonmagnetic substrate 2 and is further successively laminated with the carbon protective film 7 and the top coat layer 8 thereon. The top coat layer 8 contains the graft polymer of fluorine as the lubricating agent. The graft polymer is a graft polymer synthesized by using a reactive oligomer=high mol.wt. monomer having a polymerizable functional group at one terminal of the molecular chain. the synthetic graft polymer has preferably about 500-20,000 (mol.wt. of macromer) in the branch part and the mol.wt. of the graft polymer is preferably about 3,000-100,000. The durability, wear resistance, weatherability, corrosion resistance, etc., are thereby improved and the head attraction is decreased. |
