Magnetic recording medium

Abstract

The present invention provides a magnetic recording media made possible to improve reliability and durability of the magnetic recording media with an extremely thin overcoat. A magnetic recording media made by forming at least a magnetic coat and an overcoat on a substrate of non-magnetic magnetic disk on which surface a liquid lubricant having a structure of perfluoropolyether is coated, wherein average roughness of overcoat surface Ra is less than 0.8 nm, said overcoat being a diamond-like-carbon with a thickness in a range of 1.5-4.5 nm, and said lubricant on said carbon overcoat containing a lubricant component having a structure represented by chemical formula (1): (where, p=5-36, q=4-30, x=1-5)

What is claimed is  
     
         1 . A magnetic recording media made by forming at least a magnetic layer and an overcoat on a substrate of non-magnetic disk on which surface a liquid lubricant of a perfluoropolyether structure is coated, wherein surface of said overcoat having less than 0.8 nm average roughness Ra, said overcoat being a layer of diamond-like-carbon with less than 5 nm thickness, and said lubricant coat on said overcoat containing a lubricant component having a structure represented by following chemical formula (1):  
       
         
           
           
               
               
           
         
       
       (where, p=5-36, q=4-30, x=1-5)  
     
     
         2 . The magnetic recording media according to  claim 1 , wherein said lubricant coat on said overcoat contains more than 30% of a lubricant component having a structure represented by chemical formula (1).  
     
     
         3 . The magnetic recording media according to  claim 1 , wherein principal chain of said lubricant component having a structure represented by chemical formula (1) has an average molecular weight of 1500-2500.  
     
     
         4 . A magnetic recording media made by forming at least a magnetic layer and an overcoat on a substrate of non-magnetic magnetic disk on which surface a liquid lubricant of a perfluoropolyether structure is coated, wherein surface of said overcoat having less than 0.8 nm average roughness Ra, said overcoat being a layer of diamond-like-carbon with a thickness in a range of 1.5-4.5 nm, and said lubricant coat on said carbon overcoat containing a lubricant component having a structure represented by following chemical formula (1):  
       
         
           
           
               
               
           
         
       
       (where p=5-36, q=4-30, x=1-5)  
     
     
         5 . The magnetic recording media according to  claim 4 , wherein said lubricant coat on said carbon overcoat contains more than 30% of lubricant component having a structure represented by chemical formula (1).  
     
     
         6 . The magnetic recording media according to  claim 4 , wherein the principal chain of said lubricant having a structure represented by chemical formula (1) has an average molecular weight of 1500-2500.