ELECTRICAL STEEL SHEET COATING COMPOSITION, ELECTRICAL STEEL SHEET, LAMINATED CORE AND ROTATING ELECTRIC MACHINE Russian patent published in 2023 - IPC C09D163/00 C23C22/00 B32B15/92 H01F1/18 H02K1/04 H01F27/245 

FIELD: coating compositions.

SUBSTANCE: present invention relates to a coating composition for electrical steel sheet containing: epoxy resin; a first hardener consisting of a phenolic resin including a phenolic framework with either or both of an alkyl group and an alkoxy group; and one or more second hardeners selected from phenol-resol resin and phenol-novolac resin, wherein the amount of the first hardener is 5 parts by mass or more and 150 parts by mass or less per 100 parts by mass of epoxy resin. The invention also relates to an electrical steel sheet that has an insulating coating with such a coating composition on its surface, to a laminated core containing a plurality of such electrical steel sheets that are laminated and glued together, as well as to a rotating electrical machine containing such a laminated core.

EFFECT: providing both excellent magnetic characteristics and excellent heat resistance of the electrical steel sheet, high enough to maintain sufficient adhesive strength between the electrical steel sheets even in a high temperature state when laminated cores containing a plurality of such electrical steel sheets are in operation in a rotating electric machine.

7 cl, 7 dwg, 2 tbl, 16 ex