US 12,421,438 B2
Alumina powder, resin composition, and heat dissipation component
Takafumi Komaki, Tokyo (JP); Junya Nitta, Tokyo (JP); Yoshiaki Okamoto, Tokyo (JP); Masakazu Hirata, Tokyo (JP); and Genta Karino, Tokyo (JP)
Assigned to DENKA COMPANY LIMITED, Tokyo (JP)
Appl. No. 17/913,094
Filed by DENKA COMPANY LIMITED, Tokyo (JP)
PCT Filed Mar. 24, 2021, PCT No. PCT/JP2021/012309
§ 371(c)(1), (2) Date Sep. 20, 2022,
PCT Pub. No. WO2021/200491, PCT Pub. Date Oct. 7, 2021.
Claims priority of application No. 2020-063554 (JP), filed on Mar. 31, 2020.
Prior Publication US 2023/0193103 A1, Jun. 22, 2023
Int. Cl. C09K 5/14 (2006.01); C08K 3/08 (2006.01); C08K 7/18 (2006.01)
CPC C09K 5/14 (2013.01) [C08K 3/08 (2013.01); C08K 7/18 (2013.01); C08K 2003/0812 (2013.01); C08K 2201/003 (2013.01); C08K 2201/006 (2013.01)] 8 Claims
OG exemplary drawing
 
1. An alumina powder comprising:
a first alumina particle having an average particle diameter of 0.1 μm or more and less than 1 μm;
a second alumina particle having an average particle diameter of 1 μm or more and less than 10 μm; and
a third alumina particle having an average particle diameter of 10 μm or more and 100 μm or less, wherein
each of the average particle diameters is a particle diameter measured using a laser light diffraction scattering particle size distribution analyzer,
an average sphericity of the first alumina particle having a projected area equivalent circle diameter of 0.1 μm or more and 1 μm or less as determined by microscopy is 0.80 or more and 0.98 or less,
a specific surface area of the first alumina particle is 1.9 m2/g or more and 20.0 m2/g or less, and a content ratio of an αcrystal phase is 80% by mass or more.