Patent ID: 8492011

Claim:
A lubricant compound to be contained in a lubricating layer of a magnetic disk having at least a magnetic layer, a protective layer, and the lubricating layer formed in this order over a substrate, wherein said lubricant compound comprises a compound which has a perfluoropolyether main chain in a structure thereof, an aromatic group located at a position except each end of a molecule thereof, and a polar group at each end of the molecule, wherein the aromatic group is selected from the group consisting of phenyl group, naphthylene group, biphenylene group, phthalimidyl group, and aniline group, wherein said lubricant compound further contains polar groups located at both sides of and adjacent to the aromatic group, and wherein each of the polar groups in the compound is selected from the group consisting of an amino group, a carboxyl group, an aldehyde group, a carbonyl group and a sulfonic group.