US 12,306,578 B2
Hydrophobic silica powder and toner resin particle
Kazui Omokawa, Fukuchiyama (JP); Yuma Negishi, Fukuchiyama (JP); and Yasuhiro Fuma, Kawasaki (JP)
Assigned to FUSO CHEMICAL CO., LTD., Osaka (JP)
Appl. No. 17/436,143
Filed by FUSO CHEMICAL CO., LTD., Osaka (JP)
PCT Filed Feb. 26, 2020, PCT No. PCT/JP2020/007587
§ 371(c)(1), (2) Date Sep. 3, 2021,
PCT Pub. No. WO2020/179559, PCT Pub. Date Sep. 10, 2020.
Claims priority of application No. 2019-040722 (JP), filed on Mar. 6, 2019.
Prior Publication US 2022/0128914 A1, Apr. 28, 2022
Int. Cl. G03G 9/08 (2006.01)
CPC G03G 9/0819 (2013.01) 7 Claims
 
1. A hydrophobic silica powder having a particle size (D50) as measured by a laser diffraction method of 50 nm or more and 250 nm or less, a particle size distribution index (D90/D10) of 3.0 or less, a hydrophobicity of 60% by volume or more, and an organic acid content of 1 to 300 ppm.