	US 12,426,224 B2
	Radio wave absorbing composition and radio wave absorber
Yoshihiro Nakai, Minami-ashigara (JP); and Hirokazu Hashimoto, Minami-ashigara (JP)
Assigned to FUJIFILM Corporation, Tokyo (JP)
Filed by FUJIFILM Corporation, Tokyo (JP)
Filed on Feb. 8, 2022, as Appl. No. 17/666,894.
Application 17/666,894 is a continuation of application No. PCT/JP2020/029622, filed on Aug. 3, 2020.
Claims priority of application No. 2019-148183 (JP), filed on Aug. 9, 2019.
Prior Publication US 2022/0167535 A1, May 26, 2022
Int. Cl. H05K 9/00 (2006.01); C08K 9/04 (2006.01); C08K 9/06 (2006.01); H01F 1/113 (2006.01)

CPC H05K 9/0083 (2013.01) [C08K 9/04 (2013.01); C08K 9/06 (2013.01); H01F 1/113 (2013.01); H05K 9/0075 (2013.01)]

19 Claims

1. A radio wave absorbing composition comprising:

a magnetic powder; and

a binder,

wherein the magnetic powder is a powder of a substitution-type hexagonal ferrite subjected to surface treatment with a surface treatment agent,

the binder is a polyamide, and

the substitution-type hexagonal ferrite has a constitution represented by General Formula 1,

General Formula 1: AFe_(12-x)Al_xO₁₉

in General Formula 1, A represents one or more kinds of atoms selected from the group consisting of Sr, Ba, Ca, and Pb, and x satisfies 1.50≤x≤8.00.