Patent ID: 8920872

Claim:
A manufacturing method of a magnetic disk in which at least a magnetic layer, a carbon protective layer, and a lubrication layer are sequentially formed on a substrate, comprising the steps of: forming a film of a lubricant composition containing a lubricant compound having a perfluoropolyether main chain in the molecular structure and also an aromatic group or a phosphazene ring on the carbon protective layer to form the lubrication layer; and then subjecting the magnetic disk to ultraviolet irradiation under a nitrogen gas or an inert gas atmosphere having no oxygen and under an atmospheric temperature to a range of 90 to 140° C., wherein, in the subjecting step, a predetermined space region which contains the magnetic disk to be subjected to said ultraviolet irradiation is covered by a housing which is formed, at least on the ultraviolet irradiation side, of a transparent member transmitting the ultraviolet rays and while the nitrogen gas or the inert gas is made to flow into said housing, and the magnetic disk in the housing is subjected to the ultraviolet irradiation from the outside of said housing, wherein the atmospheric temperature inside the housing during the ultraviolet irradiation is adjusted to 90 to 140° C., wherein the predetermined space region is 8000 cm 3 or less, and wherein the lubricant compound is represented by one of the following formulas: wherein Rf represents and m and n each represent an integer of not less than 1.