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US 2023/0260683 A1Published application
Magnetic Beads, Magnetic Beads Dispersion Liquid, Method Of Manufacturing Magnetic Beads, And Method Of Manufacturing Magnetic Beads Dispersion Liquid
AssigneeSeiko Epson Corporation
InventorAkira ARAI
Life of this patent
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Abstract
Magnetic beads include: a magnetic metal powder; and a coating layer covering a surface of the magnetic metal powder. t/D50, which is a ratio of a thickness t of the coating layer to the magnetic beads diameter D50, is from 0.0001 to 0.05, and a Vickers hardness of the magnetic metal powder is 100 or more.
Claims8
Magnetic beads comprising:
- a magnetic metal powder;
- and
- a coating layer covering a surface of the magnetic metal powder, wherein
- D50, which is a 50% particle diameter on a volume basis in a particle size distribution of the magnetic beads, is from 0.5 μm to 50 μm, a ratio of an average thickness (t) of the coating layer to the D50, that is, t/D50, is from 0.0001 to 0.05, and a Vickers hardness of the magnetic metal powder is 100 or more.
1 more element
Magnetic beads dispersion liquid comprising:
- a magnetic bead including a magnetic metal powder and a coating layer covering a surface of the magnetic metal powder;
- and
- a dispersion medium being a remainder, that is an aqueous solution or an organic solvent, wherein
- D50, which is a 50% particle diameter on a volume basis in a particle size distribution of the magnetic beads, is from 0.5 μm to 50 μm, a ratio of an average thickness (t) of the coating layer to the D50, that is, t/D50, is from 0.0001 to 0.05, and a Vickers hardness of the magnetic metal powder is 100 or more.
1 more element
A method of manufacturing magnetic beads comprising:
- a magnetic metal powder manufacturing step of obtaining a magnetic metal powder;
- a coating step of forming a coating layer on the magnetic metal powder;
- a classifying step of classifying the magnetic metal powder or the magnetic metal powder on which the coating layer is formed, the classifying step being performed before or after the coating step;
- and
- a heat treatment step of performing a heat treatment on the magnetic metal powder on which the coating layer is formed, the heat treatment step being performed after the coating step, wherein
- in the classifying step, the classification is performed such that D50, which is a 50% particle diameter on a volume basis in a particle size distribution of the magnetic beads, is from 0.5 μm to 50 μm,
- in the coating step, the coating layer is formed such that a ratio of an average thickness (t) of the coating layer to the D50, that is, t/D50, is from 0.0001 to 0.05, and
- in the heat treatment step, the heat treatment is performed such that a Vickers hardness of the magnetic metal powder including the coating layer is 100 or more.
5 more elements
A method of manufacturing magnetic beads dispersion liquid comprising:
- manufacturing the magnetic beads by manufacturing a magnetic metal powder and forming a coating layer on the magnetic metal powder such that D50, which is a 50% particle diameter on a volume basis in a particle size distribution, is from 0.5 μm to 50 μm, a ratio of an average thickness (t) of the coating layer to the D50, that is, t/D50, is from 0.0001 to 0.05, and a Vickers hardness of the magnetic metal powder is 100 or more;
- and
- mixing and dispersing the magnetic beads in a dispersion medium composed of an aqueous solution or an organic solvent.
Dependencies are inferred from the claim text.