US 11,749,305 B2
Magnetic recording medium, tape cartridge, and data processing method
Minoru Yamaga, Miyagi (JP); and Kazuya Hashimoto, Miyagi (JP)
Assigned to Sony Group Corporation, Tokyo (JP)
Appl. No. 16/649,206
Filed by Sony Group Corporation, Tokyo (JP)
PCT Filed Oct. 18, 2019, PCT No. PCT/JP2019/041188
§ 371(c)(1), (2) Date Mar. 20, 2020,
PCT Pub. No. WO2021/033340, PCT Pub. Date Feb. 25, 2021.
Claims priority of application No. 2019-149509 (JP), filed on Aug. 16, 2019.
Prior Publication US 2022/0165301 A1, May 26, 2022
Int. Cl. G11B 5/71 (2006.01); G11B 5/66 (2006.01); G11B 5/714 (2006.01)
CPC G11B 5/71 (2013.01) [G11B 5/674 (2021.05); G11B 5/714 (2013.01)] 14 Claims
OG exemplary drawing
 
1. A tape-shaped magnetic recording medium comprising:
a magnetic layer; an underlayer; a base layer; and a back layer, wherein
the underlayer has a thickness of 0.5 μm or more and 0.9 μm or less,
the magnetic recording medium has an average thickness tT of 5.6 μm or less,
the magnetic recording medium includes a lubricant,
the magnetic recording medium has pores, and the pores have an average diameter of 6 nm or more and 11 nm or less when the diameters of the pores are measured in a state where the lubricant has been removed from the magnetic recording medium and the magnetic recording medium has been dried, and
the magnetic recording medium has Young's modulus of 7.90 GPa or less in a longitudinal direction thereof;
having a friction coefficient ratio (μB/μA) of 1.0 to 2.0, wherein μA represents a coefficient of dynamic friction between a magnetic layer side surface of the magnetic recording medium and a magnetic head in a state where a tension of 0.4 N is applied to the magnetic recording medium in a longitudinal direction thereof, and μB represents a coefficient of dynamic friction between the magnetic layer side surface of the magnetic recording medium and the magnetic head in a state where a tension of 1.2 N is applied to the magnetic recording medium in the longitudinal direction,
wherein an amount of dimensional change of the magnetic recording medium in a width direction thereof between a state in which a tension of 0.5 N is applied to the magnetic recording medium in a longitudinal direction thereof and a state in which a tension of 1.0 N is applied to the magnetic recording medium in the longitudinal direction is 4.0 μm or more and 5.0 μm or less.