RU-2026111807-A - ELECTRICAL STEEL SHEET WITH ADHESIVE COATING ON THE SURFACE, LAMINATED CORE AND METHODS OF THEIR MANUFACTURING

Inventors

• ФУКУТИ, Минако
• Такеда, Кадзутоси
• ОГАВА, Хироаки
• ФУКУДА, Тацуки

Assignees

• НИППОН СТИЛ КОРПОРЕЙШН

Dates

Publication Date

20260505

Application Date

20240926

Priority Date

20230926

Claims (20)

1. 1. A sheet of electrical steel with an adhesive coating on the surface, containing:
2. electrical steel sheet; and
3. an adhesive coating provided on at least a portion of one surface or both surfaces of an electrical steel sheet,
4. at the same time
5. the adhesive coating comprises a particle A of a (meth)acrylic resin containing a structural unit derived from a monomer having a self-crosslinking group and a water-soluble (meth)acrylic resin B, and
6. The average molecular weight of the adhesive coating is 150,000-250,000.
7. 2. A sheet of electrical steel with an adhesive coating on the surface according to paragraph 1, wherein the average molecular weight of the sol fraction of the adhesive coating after heating the adhesive coating at 200°C for 5 minutes is 50,000-100,000.
8. 3. An electrical steel sheet with an adhesive coating on the surface according to claim 1, wherein the water-soluble (meth)acrylic resin B is a (meth)acrylic resin containing a structural unit derived from a monomer having a self-crosslinking group.
9. 4. A sheet of electrical steel with an adhesive coating on the surface according to paragraph 1, wherein the ratio of the mass of the particle A of the (meth)acrylic resin to the mass of the water-soluble (meth)acrylic resin B is from 95/5 to 85/15.
10. 5. An electrical steel sheet with an adhesive coating on the surface according to claim 1, wherein the self-crosslinking group of the (meth)acrylic resin particle A is at least one selected from the group consisting of an N-methylol group, an N-butylol group, and a glycidyl group.
11. 6. A laminated core comprising a plurality of sheets of electrical steel with an adhesive coating on the surface according to any one of paragraphs 1-5, wherein the sheets of electrical steel with an adhesive coating on the surface are laminated, wherein the sheets of electrical steel are glued together with a cured film of the adhesive coating.
12. 7. The laminated core according to item 6, wherein the laminated core has a filling factor of from 96% to 98%.
13. 8. A method for manufacturing a sheet of electrical steel with an adhesive coating on the surface according to paragraph 1, comprising:
14. a coating step of applying a coating liquid for forming an adhesive coating, comprising a (meth)acrylic resin particle A containing a structural unit derived from a monomer having a self-crosslinking group and a water-soluble (meth)acrylic resin B, to at least a part of one surface or both surfaces of the electrical steel sheet, to obtain a coated steel sheet; and
15. a coating formation step in which the coated steel sheet is heated to a drying temperature of 100°C to 200°C at a heating rate of 6.0°C/s or less, the coated steel sheet is kept within a temperature range of (drying temperature - 10°C) to the drying temperature for 10-90 seconds, and the coated steel sheet is dried to form an adhesive coating on one surface or each of both surfaces of the electrical steel sheet.
16. 9. A method for producing a sheet of electrical steel with an adhesive coating on the surface according to claim 8, wherein in the coating liquid for forming the adhesive coating, the ratio of the mass of the particle A of the (meth)acrylic resin to the mass of the water-soluble (meth)acrylic resin B is from 95/5 to 85/15.
17. 10. A method for manufacturing a laminated core according to paragraph 6, comprising:
18. a punching stage in which a sheet of electrical steel with an adhesive coating on the surface is punched, producing a cut blank;
19. a stacking stage, in which multiple cut-out blanks are layered to form a stack; and
20. a gluing stage in which the bag is heated to a crimping temperature within the temperature range from 200°C to 300°C, the bag is maintained within the range from (crimping temperature - 10°C) to the crimping temperature for 30-60 minutes while applying a crimping force of 0.5-10 MPa and the adhesive coating is cured, forming a cured coating.