Magnetic recording medium for thermally assisted recording
View Patent ↗A magnetic recording medium for use in a thermally assisted recording system is disclosed. The magnetic recording medium comprises at least a magnetic layer, a protective layer and a lubricant layer formed on a nonmagnetic substrate, wherein a lubricant of the lubricant layer exhibits such a heat resistance that an amount of volatilization when the magnetic layer is heated to a temperature not lower than a temperature Tw is less than 1% with respect to an initial amount of the lubricant in an unheated condition. The present invention addresses a problem of the heat resistance performance of the lubricant for use in magnetic recording media and provides a magnetic recording medium exhibiting high heat resistance.
1. A magnetic recording medium for use in a thermally assisted recording system comprising at least a magnetic layer, a protective layer and a lubricant layer formed on a nonmagnetic substrate, wherein a lubricant in the lubricant layer has a heat resistance such that an amount of volatilization when the magnetic layer is heated to a temperature not lower than a temperature Tw is less than 1% with respect to an initial amount of the lubricant in an unheated condition, wherein the lubricant composing the lubricant layer is a compound represented by formula (1) and has a molecular weight in a range of 500 to 10,000
wherein “Rf” represents CF 3 CF 2 CF 2 O—(CF 2 CF 2 CF 2 O) n —CF 2 CF 2 , and “n” is a positive integer.
2. The magnetic recording medium according to claim 1 , wherein the temperature Tw is in a range of 150° C. to 350° C.
3. A magnetic recording medium for use in thermally assisted recording system comprising at least a magnetic layer, a protective layer and a lubricant layer formed on a nonmagnetic substrate comprising a lubricant compound having a molecular weight in a range of 500 to 10,000 which lubricant compound is represented by formula (1)
wherein “Rf” represents CF 3 CF 2 CF 2 O—(CF 2 CF 2 CF 2 O) n —CF 2 CF 2 , and “n” is a positive integer,
wherein the lubricant compound has a heat resistance such that an amount of volatilization when the magnetic layer is heated to a temperature not lower than a temperature Tw is less than 1% with respect to an initial amount of the lubricant in an unheated condition, wherein Tw is in a range of 150° C. to 350° C.
4. A method of thermally assisted magnetic recording comprising:
providing a magnetic recording medium comprising at least a magnetic layer, a protective layer and a lubricant layer formed on a nonmagnetic substrate, wherein a lubricant in the lubricant layer has a heat resistance such that an amount of volatilization when the magnetic layer is heated to a temperature not lower than a temperature Tw is less than 1% with respect to an initial amount of the lubricant in an unheated condition, and
irradiating recording regions of the magnetic layer with a laser; and
applying a magnetic field to the irradiated regions of the magnetic layer with a magnetic head to record information,
wherein the lubricant composing the lubricant layer is a compound represented by formula (1) and has a molecular weight in a range of 500 to 10,000
wherein “Rf” represents CF 3 CF 2 CF 2 O—(CF 2 CF 2 CF 2 O) n —CF 2 CF 2 , and “n” is a positive integer.