Electrical steel sheet

Patent metadata

Field	Value
Publication number	US-11499059-B2
Application number	US-201816482663-A
Country	US
Kind code	B2
Filing date	Mar 23, 2018
Priority date	Mar 23, 2017
Publication date	Nov 15, 2022
Grant date	Nov 15, 2022

Abstract

An electrical steel sheet is described, which has an insulating coating on its surface. The insulating coating is free of chromium and comprises plate-like particles of inorganic compound and a metal phosphate. The plate-like particles of inorganic compound are in the form of secondary particles, which are formed by aggregating primary particles, and present in an amount of not less than 0.1 parts by mass and not greater than 20 parts by mass, with respect to 100 parts by mass of the metal phosphate. The secondary particles have an average particle diameter of no less than 0.05 μm and no greater than 5 μm, and have a specific surface area of 1 to 80 m2/g. The primary particles have an aspect ratio of 50 to 1000. The electrical steel sheet has excellent heat resistance, corrosion resistance, appearance, and insulating properties.

First claim

The invention claimed is:

1. An electrical steel sheet, comprising:
an insulating coating on a surface thereof,
wherein the insulating coating is free of chromium and comprises plate-like particles of an inorganic compound and a metal phosphate, and a content of the plate-like particles of the inorganic compound is no less than 0.1 parts by mass and no greater than 20 parts by mass with respect to 100 parts by mass of the metal phosphate, and
wherein the plate-like particles of the inorganic compound are in the form of secondary particles, wherein said secondary particles comprise aggregated primary particles, and
wherein the secondary particles have an average particle diameter of no less than 0.05 and no greater than 5 μm, and have a specific surface area of 1 to 80 m 2 /g, and the primary particles have an aspect ratio of 50 to 1000, and wherein in the secondary particles, the primary particles randomly overlap with each other to form a space in the secondary particles.

2. The electrical steel sheet according to claim 1 , wherein the metal phosphate is a salt of phosphoric acid with one or more metal elements selected from Al, Ba, Co, Fe, Mg, Mn, Ni and Zn.

3. The electrical steel sheet according to claim 2 , wherein the plate-like particles of the inorganic compound are an oxide, a hydroxide, a carbonate or a sulfate.

4. The electrical steel sheet according to claim 2 , wherein the plate-like particles of the inorganic compound are alumina, gibbsite, silica, talc, kaolin, smectite or mica.

5. The electrical steel sheet according to claim 2 , wherein the electrical steel sheet is a non-oriented electrical steel sheet.

6. The electrical steel sheet according to claim 1 , wherein the plate-like particles of the inorganic compound are an oxide, a hydroxide, a carbonate or a sulfate.

7. The electrical steel sheet according to claim 6 , wherein the plate-like particles of the inorganic compound are alumina, gibbsite, silica, talc, kaolin, smectite or mica.

8. The electrical steel sheet according to claim 6 , wherein the electrical steel sheet is a non-oriented electrical steel sheet.

9. The electrical steel sheet according to claim 1 , wherein the plate-like particles of the inorganic compound are alumina, gibbsite, silica, talc, kaolin, smectite or mica.

10. The electrical steel sheet according to claim 9 , wherein the electrical steel sheet is a non-oriented electrical steel sheet.

11. The electrical steel sheet according to claim 1 , wherein the electrical steel sheet is a non-oriented electrical steel sheet.

12. A coating liquid for an electrical steel sheet, wherein the coating liquid is free of chromium, the coating liquid comprising:
a solution of plate-like particles of an inorganic compound and a metal phosphate,
wherein a content of the plate-like particles of the inorganic compound is no less than 0.1 parts by mass and no greater than 20 parts by mass with respect to 100 parts by mass of the metal phosphate, and
wherein the plate-like particles of the inorganic compound are in the form of secondary particles, wherein said secondary particles comprise aggregated primary particles, and
wherein the secondary particles have an average particle diameter of no less than 0.05 μm and no greater than 5 μm, and have a specific surface area of 1 to 80 m 2 /g, and the primary particles have an aspect ratio of 50 to 1000.

13. The coating liquid according to claim 12 , wherein the metal phosphate is a salt of phosphoric acid with one or more metal elements selected from Al, Ba, Co, Fe, Mg, Mn, Ni and Zn.

14. The coating liquid according to claim 13 , wherein the plate-like particles of the inorganic compound are an oxide, a hydroxide, a carbonate or a sulfate.

15. The coating liquid according to claim 13 , wherein the plate-like particles of the inorganic compound are alumina, gibbsite, silica, talc, kaolin, smectite or mica.

16. The coating liquid according to claim 13 , wherein the coating liquid is for the electrical steel sheet that is a non-oriented electrical steel sheet.

17. The coating liquid according to claim 12 , wherein the plate-like particles of the inorganic compound are an oxide, a hydroxide, a carbonate or a sulfate.

18. The coating liquid according to claim 17 , wherein the plate-like particles of the inorganic compound are alumina, gibbsite, silica, talc, kaolin, smectite or mica.

19. The coating liquid according to claim 12 , wherein the plate-like particles of the inorganic compound are alumina, gibbsite, silica, talc, kaolin, smectite or mica.

20. The coating liquid according to claim 12 , wherein the coating liquid is for the electrical steel sheet that is a non-oriented electrical steel sheet.

Assignees

• Nippon Steel Corp

Inventors

• Takeda Kazutoshi
• Natori Yoshiaki
• Matsumoto Takuya
• Yashiki Hiroyoshi

Classifications

• C23C22/22

  containing alkaline earth metal cations · CPC title

• C09D7/70

  characterised by shape, e.g. fibres, flakes or microspheres · CPC title

• C22C38/02

  containing silicon · CPC title

• C08K2003/321

  Phosphates · CPC title

• C22C38/04

  containing manganese · CPC title