Magnetic recording medium and magnetic recording/reproducing apparatus
View Patent ↗The present invention relates to a magnetic recording medium in which a lubricant layer contains a compound A represented by general formula (1) and a compound B represented by general formula (2), satisfying (A/B)=0.2 to 3.0, and has an average thickness of 0.8 nm to 2 nm. R 1 —C 6 H 4 OCH 2 CH(OH)CH 2 OCH 2 —R 2 —CH 2 OCH 2 CH(OH)CH 2 OH . . . (1) (R 1 is an alkoxy group having 1 to 4 carbon atoms. R 2 is —CF 2 O(CF 2 CF 2 O) x (CF 2 O) y CF 2 — (x, y=0 to 15), —CF 2 CF 2 O(CF 2 CF 2 CF 2 O) z CF 2 CF 2 — (z=1 to 15), —CF 2 CF 2 CF 2 O(CF 2 CF 2 CF 2 CF 2 O) n CF 2 CF 2 CF 2 — (n=0 to 4). HOCH 2 CF 2 CF 2 O(CF 2 CF 2 CF 2 O) m CF 2 CF 2 CH 2 OCH 2 CH(OH)CH 2 OH . . . (2) (m is an integer).
1. A magnetic recording medium comprising at least a magnetic layer, a protective layer and a lubricant layer in this order on a non-magnetic substrate, wherein
the protective layer is made of carbon or carbon nitride;
the lubricant layer which is formed on and in contact with the protective layer, comprises
a compound A represented by the following general formula (1):
R 1 —C 6 H 4 OCH 2 CH(OH)CH 2 OCH 2 —R 2 —CH 2 OCH 2 CH(OH)CH 2 OH (1)
wherein, R 1 is an alkoxy group having 1 to 4 carbon atoms,
R 2 is
—CF 2 O(CF 2 CF 2 O) x (CF 2 O) y CF 2 —
wherein in parentheses of x and y, connection in this order, in reverse, or randomly; and x, y are real numbers of 0 to 15, respectively,
—CF 2 CF 2 O(CF 2 CF 2 CF 2 O) z CF 2 CF 2 —
wherein z is a real number of 1 to 15, or
—CF 2 CF 2 CF 2 O(CF 2 CF 2 CF 2 CF 2 O) n CF 2 CF 2 CF 2 —
wherein n is a real number from 0 to 4, and
a compound B represented by the following general formula (2):
HOCH 2 CF 2 CF 2 O(CF 2 CF 2 CF 2 O) m CF 2 CF 2 CH 2 OCH 2 CH(OH)CH 2 OH (2)
wherein m is an integer;
a mass ratio (A/B) of the compound A with respect to the compound B is in the range of 0.2 to 3.0; and
an average film thickness of the lubricant layer is 0.8 nm to 2 nm.
2. The magnetic recording medium according to claim 1 , wherein the total surface energy on the surface of the magnetic recording medium is 25.5 mJ/m 2 or less.
3. The magnetic recording medium according to claim 1 , wherein the compound A has an average molecular weight in the range of 1,500 to 1,800.
4. The magnetic recording medium according to claim 1 , wherein the compound B has an average molecular weight in the range of 1,000 to 1,700.
5. A magnetic recording/reproducing apparatus comprising:
the magnetic recording medium according to claim 1 ,
a medium drive unit that drives the magnetic recording medium in a recording direction,
a magnetic head for recording/reproducing information on the magnetic recording medium,
a head driving unit for driving the magnetic head relative to the magnetic recording medium, and
a recording/reproducing signal processing unit for processing a recording/reproducing signal from the magnetic head.