US 12,444,523 B2
Rare earth magnet assembly and preparation method
Yuta Kuribara, Echizen (JP); and Kazuhito Akada, Echizen (JP)
Assigned to SHIN-ETSU CHEMICAL CO., LTD., Tokyo (JP)
Filed by SHIN-ETSU CHEMICAL CO., LTD., Tokyo (JP)
Filed on Jan. 21, 2022, as Appl. No. 17/581,238.
Claims priority of application No. 2021-018902 (JP), filed on Feb. 9, 2021.
Prior Publication US 2022/0254552 A1, Aug. 11, 2022
Int. Cl. H01F 1/057 (2006.01); C22C 38/00 (2006.01); H01F 41/02 (2006.01)
CPC H01F 1/0577 (2013.01) [C22C 38/005 (2013.01); H01F 41/0293 (2013.01); C22C 2202/02 (2013.01)] 8 Claims
OG exemplary drawing
 
1. A method for preparing a rare earth magnet assembly, comprising the steps of:
placing two rare earth magnet pieces so that two rare earth magnet pieces are abutted at their side surfaces to define an abutment interface, and top surfaces of the magnet pieces are disposed adjacent to each other across the rim of the abutment interface;
applying a UV-curable resin composition on at least a portion of the adjacent top surfaces of the magnet pieces, so that the UV-curable resin composition continuously extends across the rim of the abutment interface and over the adjacent top surfaces; and
curing the UV-curable resin composition by irradiating UV radiation to the UV-curable resin composition to form a coating of cured resin to join the magnet pieces together so that the two rare earth magnet pieces are directly contacted to each other at the abutment interface, and the coating has a pencil hardness of at least 6H according to JIS K 5600.