Method of producing magnetic powder

Patent metadata

Field	Value
Publication number	US-11594352-B2
Application number	US-202017033775-A
Country	US
Kind code	B2
Filing date	Sep 26, 2020
Priority date	Sep 27, 2019
Publication date	Feb 28, 2023
Grant date	Feb 28, 2023

Abstract

The present disclosure provides a method of producing a magnetic powder capable of providing a bonded magnet having a high remanence. The present disclosure relates to a method of producing a magnetic powder, including: 1) mixing an alkyl silicate with an acidic solution; 2) mixing the resultant alkyl silicate mixture with a SmFeLaN anisotropic magnetic powder; and 3) mixing the resultant magnetic powder mixture with an alkali solution.

First claim

What is claimed is:

1. A method of producing a magnetic powder, comprising:
1) mixing an alkyl silicate with an acidic solution;
2) mixing a resultant alkyl silicate mixture with a SmFeLaN anisotropic magnetic powder; and
3) mixing a resultant magnetic powder mixture with an alkali solution.

2. The method according to claim 1 ,
wherein the SmFeLaN anisotropic magnetic powder has an average particle size of at least 3.9 μm and not greater than 6 μm.

3. The method according to claim 1 ,
wherein the acidic solution has a pH of at least 3 and not higher than 4.

4. The method according to claim 1 ,
wherein an alcohol is mixed simultaneously with the acidic solution.

5. The method according to claim 1 , further comprising, before the step 2), subjecting the SmFeLaN anisotropic magnetic powder to phosphate treatment.

6. The method according to claim 1 , further comprising, after the step 3), treating with a silane coupling agent.

7. The method according to claim 1 ,
wherein the SmFeLaN anisotropic magnetic powder is formed from a precipitate containing Sm, Fe, and La.

8. A method of preparing a bonded magnet compound, comprising:
1) mixing an alkyl silicate with an acidic solution;
2) mixing a resultant alkyl silicate mixture with a SmFeLaN anisotropic magnetic powder;
3) mixing a resultant magnetic powder mixture with an alkali solution; and
4) mixing a resultant magnetic powder from 3) with a thermoplastic resin.

9. The method according to claim 8 ,
wherein the bonded magnet compound contains at least 62% by volume of the SmFeLaN anisotropic magnetic powder.

10. A method of producing a bonded magnet, comprising:
1) mixing an alkyl silicate with an acidic solution;
2) mixing a resultant alkyl silicate mixture with a SmFeLaN anisotropic magnetic powder;
3) mixing a resultant magnetic powder mixture with an alkali solution;
4) mixing a resultant magnetic powder from 3) with a thermoplastic resin; and
5) subjecting a resultant mixture from 4) to injection molding.

Assignees

• Nichia Corp

Inventors

• Maehara Hisashi

Classifications

• H01F41/026

  protecting methods against environmental influences, e.g. oxygen, by surface treatment (magnetic particles with skin H01F1/061, H01F1/09, H01F1/24, H01F1/33 and G11B5/706) · CPC title

• H01F41/0266 Primary

  Moulding; Pressing (H01F41/0273 takes precedence; hard magnetic particles H01F1/06, H01F1/11) · CPC title

• H01F1/0578 Primary

  bonded together · CPC title

• H01F1/059

  and Va elements, e.g. Sm2Fe17N2 · CPC title

• H01F1/0558

  bonded together · CPC title