US 12,230,438 B2
Compound for bonded magnet, bonded magnet, method of producing same, and resin composition for bonded magnets
Satoshi Yamanaka, Tokushima (JP); Takayuki Yano, Tokushima (JP); Shuichi Tada, Komatsushima (JP); Masahiro Abe, Tokushima (JP); and Kenta Iwai, Anan (JP)
Assigned to NICHIA CORPORATION, Anan (JP)
Filed by NICHIA CORPORATION, Anan (JP)
Filed on Nov. 16, 2021, as Appl. No. 17/455,155.
Claims priority of application No. 2020-191743 (JP), filed on Nov. 18, 2020; application No. 2020-192544 (JP), filed on Nov. 19, 2020; application No. 2020-201165 (JP), filed on Dec. 3, 2020; application No. 2021-008210 (JP), filed on Jan. 21, 2021; application No. 2021-008211 (JP), filed on Jan. 21, 2021; and application No. 2021-008212 (JP), filed on Jan. 21, 2021.
Prior Publication US 2022/0157520 A1, May 19, 2022
Int. Cl. B29C 45/00 (2006.01); B29B 7/88 (2006.01); H01F 1/057 (2006.01); H01F 41/02 (2006.01); B29K 77/00 (2006.01); B29K 505/00 (2006.01)
CPC H01F 41/0253 (2013.01) [B29B 7/88 (2013.01); B29C 45/0001 (2013.01); H01F 1/0571 (2013.01); B29K 2077/00 (2013.01); B29K 2505/00 (2013.01); B29K 2995/0008 (2013.01)] 17 Claims
 
1. A method of producing a compound for thermoplastic resin-containing bonded magnets, the method comprising:
heat-curing a thermosetting resin and a curing agent having a ratio of a number of reactive groups of the curing agent to a number of reactive groups of the thermosetting resin of at least 2 but not higher than 11 to obtain an additive for thermoplastic resin-containing bonded magnets,
wherein the additive for thermoplastic resin-containing bonded magnets is a cured product of the thermosetting resin and the curing agent; and
kneading the additive for thermoplastic resin-containing bonded magnets, magnetic powder, and a thermoplastic resin to obtain the compound for thermoplastic resin-containing bonded magnets in which a filling ratio of the magnetic powder is at least 91.5% by mass.