Electrical steel sheet and manufacturing method thereof

Patent metadata

Field	Value
Publication number	US-9984801-B2
Application number	US-200913128302-A
Country	US
Kind code	B2
Filing date	Nov 10, 2009
Priority date	Nov 27, 2008
Publication date	May 29, 2018
Grant date	May 29, 2018

Abstract

An electrical steel sheet is provided which is capable of improving heat conductivity. The electrical steel sheet includes: a steel strip ( 1 ) for an electrical steel sheet; and an insulating film ( 2 ) formed at a surface of the steel strip ( 1 ) and containing metal phosphate and organic resin. At least a part of the metal phosphate includes at least one kind of crystal structure selected from a group consisting of a cubic system, a tetragonal system, a hexagonal system, and an orthorhombic system. The organic resin contains at least one kind selected from a group consisting of an acryl-based resin, an epoxy-based resin, and a polyester resin having a carboxyl group or a hydroxyl group at a surface of an emulsion particle for one part by mass to 50 parts by mass relative to 100 parts by mass of the metal phosphate.

First claim

The invention claimed is:

1. An electrical steel sheet, comprising:
a steel strip for an electrical steel sheet; and
an insulating film formed at a surface of the steel strip and containing metal phosphate and organic resin,
wherein
at least a part of the metal phosphate includes at least one kind of crystal structure selected from the group consisting of a cubic system, a tetragonal system, a hexagonal system, and an orthorhombic system, and
the organic resin contains at least one kind selected from the group consisting of an acryl-based resin, an epoxy-based resin, and a polyester resin having a carboxyl group or a hydroxyl group at a surface of an emulsion particle for one part by mass to 50 parts by mass relative to 100 parts by mass of the metal phosphate.

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

3. The electrical steel sheet according to claim 1 , wherein 20 mass percent or more of the metal phosphate includes the at least one kind of crystal structure.

4. The electrical steel sheet according to claim 1 , wherein 50 mass percent or more of the metal phosphate includes the at least one kind of crystal structure.

5. The electrical steel sheet according to claim 1 , wherein at least a part of the metal phosphate includes a crystal structure of the cubic system or the orthorhombic system.

6. The electrical steel sheet according to claim 2 , wherein at least a part of the metal phosphate includes a crystal structure of the cubic system or the orthorhombic system.

7. The electrical steel sheet according to claim 3 , wherein at least a part of the metal phosphate includes a crystal structure of the cubic system or the orthorhombic system.

8. The electrical steel sheet according to claim 4 , wherein at least a part of the metal phosphate includes a crystal structure of the cubic system or the orthorhombic system.

9. The electrical steel sheet according to claim 1 , wherein the insulating film does not contain chromic acid.

10. The electrical steel sheet according to claim 1 , wherein the insulating film is formed by:
coating a treatment solution on the surface of the steel strip to form a coating film; and
baking the coating film,
wherein a solution of a mixture of the metal phosphate and the organic resin is manufactured;
a polyhydric alcohol compound is added to the solution of the mixture to form the treatment solution; and
the treatment solution containing the solution of the mixture and the polyhydric alcohol compound is manufactured.

11. The electrical steel sheet according to claim 1 , wherein the steel strip contains, in mass %:
Si: 0.1% or more and less than 4.0%;
Al: 0.05% or more and less than 3.0%;
Mn: 0%-1.0%;
S: less than 0.01%;
N: less than 0.01%; and
C: less than 0.01%.

12. The electrical steel sheet according to claim 10 , wherein the baking of the coating film is performed by:
heating the steel strip to which the treatment solution is coated up to 230° C. to 360° C. with a rate of 25° C./sec to 65° C./sec;
next retaining the steel strip at the temperature of 230° C. to 360° C. for 10 seconds to 30 seconds; and
next cooling the steel strip to 100° C. with a rate of 20° C./sec to 85° C./sec.

13. The electrical steel sheet according to claim 1 , wherein the insulating film is an organic film.

Assignees

• Takeda Kazutoshi
• Kosuge Kenji
• Takase Tatsuya
• Fujii Hiroyasu
• Nippon Steel & Sumitomo Metal Corp

Inventors

• Takeda Kazutoshi
• Kosuge Kenji
• Takase Tatsuya
• Fujii Hiroyasu

Classifications

• Y10T428/31681

  Next to polyester, polyamide or polyimide [e.g., alkyd, glue, or nylon, etc.] · CPC title

• C22C38/04

  containing manganese · CPC title

• C22C38/06

  containing aluminium · CPC title

• Y10T428/31678

  Of metal · CPC title

• C23C22/00 Primary

  Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals · CPC title