Magnetic recording medium

Patent metadata

Field	Value
Publication number	US-2018358046-A1
Application number	US-201815996622-A
Country	US
Kind code	A1
Filing date	Jun 4, 2018
Priority date	Jun 9, 2017
Publication date	Dec 13, 2018
Grant date	—

Abstract

Provided is a magnetic recording medium including: a non-magnetic support; and a magnetic layer including particles of at least one kind of epsilon type iron oxide-based compound selected from the group consisting of ε-Fe 2 O 3 and a compound represented by Formula (1), an abrasive, and a binding agent, at least on one surface of the non-magnetic support, in which an average equivalent circle diameter of the particles of the epsilon type iron oxide-based compound is 7 nm to 18 nm, an average equivalent circle diameter of the abrasive in a plan view of the magnetic layer is 20 nm to 1,000 nm, and a coefficient of variation of the equivalent circle diameter of the abrasive is 30% to 60%. In Formula (1), A represents at least one kind of metal element other than Fe and a satisfies a relationship of 0<a<2.
ε-A a Fe 2-a O 3   (1)

First claim

What is claimed is:

1 . A magnetic recording medium comprising:
a non-magnetic support; and a magnetic layer including particles of at least one kind of epsilon type iron oxide-based compound selected from the group consisting of ε-Fe 2 O 3 and a compound represented by Formula (1), an abrasive, and a binding agent, at least on one surface of the non-magnetic support, wherein an average equivalent circle diameter of the particles of the epsilon type iron oxide-based compound is 7 nm to 18 nm, an average equivalent circle diameter of the abrasive in a plan view of the magnetic layer is 20 nm to 1,000 nm, and a coefficient of variation of the equivalent circle diameter of the abrasive is 30% to 60%,
ε-A a Fe 2-a O 3   (1)

in Formula (1), A represents at least one kind of metal element other than Fe and a satisfies a relationship of 0<a<2.

2 . The magnetic recording medium according to claim 1 ,
wherein the epsilon type iron oxide-based compound includes the compound represented by Formula (1), and A in Formula (1) is at least one kind of metal element selected from the group consisting of Ga, Al, In, Co, Zn, Ti, and Nb.

3 . The magnetic recording medium according to claim 1 ,
wherein the average equivalent circle diameter of the abrasive in a plan view of the magnetic layer is 30 nm to 800 nm.

4 . The magnetic recording medium according to claim 3 ,
wherein the average equivalent circle diameter of the abrasive in a plan view of the magnetic layer is 110 nm to 200 nm.

5 . The magnetic recording medium according to claim 1 ,
wherein a recording system is a linear recording system.

6 . The magnetic recording medium according to claim 1 , which is used in electromagnetic wave assist recording.

Assignees

• Fujifilm Corp

Inventors

• Shirata Masashi
• Fujimoto Takashi

Classifications

• G11B5/70621

  containing Co metal or alloys · CPC title

• G11B5/78 Primary

  Tape carriers · CPC title

• G11B5/714

  characterised by the dimension of the magnetic particles · CPC title

• G11B5/70642

  iron oxides · CPC title

• G11B5/7085

  non-magnetic abrasive particles · CPC title