US 12,394,436 B2
Magnetic recording medium
Eiji Nakashio, Miyagi (JP); Futoshi Sasaki, Miyagi (JP); Yuuichi Masuzawa, Miyagi (JP); Masaru Terakawa, Miyagi (JP); Minoru Yamaga, Miyagi (JP); Yoichi Kanemaki, Miyagi (JP); Kazuya Hashimoto, Miyagi (JP); Tomoe Sato, Miyagi (JP); and Nobuyuki Sasaki, Miyagi (JP)
Assigned to Sony Corporation, Tokyo (JP)
Appl. No. 15/565,050
Filed by Sony Corporation, Tokyo (JP)
PCT Filed Mar. 8, 2016, PCT No. PCT/JP2016/001263
§ 371(c)(1), (2) Date Oct. 6, 2017,
PCT Pub. No. WO2016/166931, PCT Pub. Date Oct. 20, 2016.
Claims priority of application No. 2015-081849 (JP), filed on Apr. 13, 2015.
Prior Publication US 2018/0114541 A1, Apr. 26, 2018
Int. Cl. G11B 5/733 (2006.01); G11B 5/70 (2006.01)
CPC G11B 5/733 (2013.01) [G11B 5/70 (2013.01); G11B 5/7334 (2019.05)] 22 Claims
OG exemplary drawing
 
1. A magnetic recording medium comprising:
a strip-shaped support body;
a base layer containing a binder, carbon particle powder and metal-containing particle powder; and
a recording layer,
wherein in a recording surface, in a case that a maximum indentation depth and a ratio d of a permanent strain to an elastic recovery are measured by a nanoindenter having a dihedral angle of 142.3° and subject to a load that is continuously increased to a maximum load of 200 μN and then the load is removed, the maximum indentation depth h at the maximum load of 200 μN is 85 nm≤h≤140 nm, and the ratio d of the permanent strain to the elastic recovery (permanent strain/elastic recovery) is 0.95≤d≤1.23.