Magnetic recording medium having a perfluoropolyether lubricant bonded to the surface of a carbon protective film
AssigneeNEC Corporation
InventorMasahiro Yanagisawa
Life of this patent
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Abstract
A magnetic storage medium includes a substrate, a protective film, and a lubricant film. The substrate includes a magnetic body. The protective film is formed on the substrate and constituted by a carbon thin film having dangling bonds formed on a surface thereof. The lubricant film is coated on the protective film and bonded to some of the dangling bonds. An adsorption site ratio (density of dangling bonds/density of functional groups of lubricant film) which is a ratio of the density of the dangling bonds to the density of functional groups of the lubricant film exceeds 1.
Claims5
A magnetic storage medium comprising:
- a substrate including a magnetic body deposited thereon;
- a protective film on said magnetic body of said substrate, said protective film constituted by a carbon film having dangling bonds formed on a surface thereof;
- and
- a lubricant film coated on said protective film, said lubricant film consisting of a perfluoropolyether containing functional groups having a functional group density, said functional groups bonded to said dangling bonds,
- wherein the adsorption site ratio, which is a ratio of the density of said dangling bonds present on a surface of the carbon film to the density of the functional groups present in a portion of said lubricant film which comes into contact with the surface of the carbon film exceeds 1;
- wherein the density of said dangling bonds is 10.sup.11 to 10.sup.15 bonds/cm.sup.2 ;
- and
- wherein the functional groups of said lubricant are selected from the group consisting of --OH and --COOH.
A magnetic storage medium comprising:
- a substrate including a magnetic body deposited thereon;
- a protective film formed on said magnetic body of said substrate, said protective film constituted by a carbon film having dangling bonds formed on a surface thereof;
- and
- a lubricant film coated on said protective film, said lubricant film containing functional groups selected from the group consisting of --OH and --COOH;
- wherein said functional groups have a functional group density and are bonded to said dangling bonds;
- and
- wherein the adsorption site ratio, which is a ratio of the density of said dangling bonds present on a surface of the carbon film to the density of the functional groups present in a portion of said lubricant film which comes into contact with the surface of the carbon film exceeds 1;
- wherein the density of said dangling bonds is 10.sup.11 to 10.sup.15 bonds/cm.sup.2.
Dependencies are inferred from the claim text.