Particles of β-iron oxyhydroxide-based compound, manufacturing method of the same, manufacturing method of particles of ϵ-iron oxide-based compound, and manufacturing method of magnetic recording medium

Patent metadata

Field	Value
Publication number	US-11459244-B2
Application number	US-201916251097-A
Country	US
Kind code	B2
Filing date	Jan 18, 2019
Priority date	Mar 29, 2018
Publication date	Oct 4, 2022
Grant date	Oct 4, 2022

Abstract

Disclosed are a particle of a 13-iron oxyhydroxide-based compound represented by Formula (1), in which an average equivalent circle diameter of primary particles is 5 nm to 30 nm, and a coefficient of variation of equivalent circle diameters of the primary particles is 10% to 30% [In Formula (1), A represents at least one kind of metal element other than Fe, and a represents a number that satisfies a relationship of 0≤a<1.], and applications thereof.

β-A a Fe 1-a OOH   (1)

First claim

What is claimed is:

1. A particle of a β-iron oxyhydroxide-based compound represented by Formula (1),
wherein an average equivalent circle diameter of primary particles is 5 nm to 30 nm, and
a coefficient of variation of equivalent circle diameters of the primary particles is 10% to 30%,
β-A a Fe 1-a OOH   (1)

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

2. The particle of a β-iron oxyhydroxide-based compound according to claim 1 ,
wherein A in Formula (1) is at least one kind of metal element selected from the group consisting of Ga, Co, and Ti, and a represents a number that satisfies a relationship of 0<a<1.

3. The particle of a β-iron oxyhydroxide-based compound according to claim 1 ,
wherein the average equivalent circle diameter of the primary particles is 7 nm to 15 nm, and
the coefficient of variation of equivalent circle diameters of the primary particles is 10% to 20%.

4. The particle of a β-iron oxyhydroxide-based compound according to claim 1 which is used in formation of magnetic particles.

5. The particle of a β-iron oxyhydroxide-based compound according to claim 1 , wherein the average equivalent circle diameter of the primary particles is in a range of from 5.4 nm to 12.2 nm.

6. The particle of a β-iron oxyhydroxide-based compound according to claim 1 , wherein the compound represented by Formula (1) is a compound represented by Formula (6) below:
β-X x Y y Z z Fe 1-x-y-z OOH  (6)

wherein, in Formula (6): X represents at least one kind of divalent metal element selected from the group consisting of Co, Ni, Mn, and Zn; Y represents at least one kind of tetravalent metal element selected from Ti or Sn; Z represents at least one kind of trivalent metal element selected from the group consisting of Ga, Al, and In; x represents a number that satisfies a relationship of 0<x<0.5; y represents a number that satisfies a relationship of 0<y<0.5; z represents a number that satisfies a relationship of 0<z<0.5; and x+y+z<1.

7. The particle of a β-iron oxyhydroxide-based compound according to claim 6 , wherein, in Formula (6): X is Co; Y is Ti; and Z is Ga.

8. A manufacturing method of particles of a β-iron oxyhydroxide-based compound, the method comprising:
adding an alkali agent to an aqueous solution including a compound including trivalent ferrous ions to obtain a particle dispersion liquid of a β-iron oxyhydroxide-based compound represented by Formula (1); and
extracting particles of the β-iron oxyhydroxide-based compound represented by Formula (1), in which an average equivalent circle diameter of primary particles is 5 nm to 30 nm, and a coefficient of variation of equivalent circle diameters of the primary particles is 10% to 30%, from the particle dispersion liquid by classification means,
β-A a Fe 1-a OOH   (1)

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

9. A manufacturing method of particles of a ε-iron oxide-based compound, the method comprising:
adding a silane compound including a hydrolyzable group to a dispersion liquid of the particles of a β-iron oxyhydroxide-based compound according to claim 1 to obtain a precursor particle dispersion liquid;
extracting precursor particles from the precursor particle dispersion liquid;
performing heat treatment with respect to the precursor particles at a temperature of 800° C. to 1,400° C. to obtain heat-treated particles; and
adding the heat-treated particles to an alkali aqueous solution.

10. A manufacturing method of a magnetic recording medium, the method comprising:
preparing a magnetic layer forming composition using particles of a ε-iron oxide-based compound obtained by the manufacturing method according to claim 6 ;
applying the magnetic layer forming composition onto a non-magnetic support to form a magnetic layer forming composition layer;
performing an alignment in magnetic field with respect to the formed magnetic layer forming composition layer; and
drying the magnetic layer forming composition layer subjected to the alignment in magnetic field to form a magnetic layer.

Assignees

• Fujifilm Corp

Inventors

• Naoi Kenji
• Fujimoto Takashi
• Shirata Masashi

Classifications

• H01F1/11 Primary

  in the form of particles {(for magnetic record carriers G11B5/70626)} · CPC title

• C01G49/02 Primary

  Oxides; Hydroxides {(C01G49/0018 takes precedence)} · CPC title

• G11B5/70626

  containing non-metallic substances · CPC title

• G11B5/84

  Processes or apparatus specially adapted for manufacturing record carriers · CPC title

• C01P2002/70

  defined by measured X-ray, neutron or electron diffraction data · CPC title