US 12,351,467 B2
Silica particle and method for producing the same
Yuka Zenitani, Kanagawa (JP); Koji Sasaki, Kanagawa (JP); Sakae Takeuchi, Kanagawa (JP); Yoshifumi Eri, Kanagawa (JP); and Takahiro Mizuguchi, Kanagawa (JP)
Assigned to FUJIFILM Business Innovation Corp., Tokyo (JP)
Filed by FUJIFILM Business Innovation Corp., Tokyo (JP)
Filed on Nov. 21, 2023, as Appl. No. 18/515,697.
Application 18/515,697 is a division of application No. 16/997,541, filed on Aug. 19, 2020, granted, now 11,866,340.
Claims priority of application No. 2020-053001 (JP), filed on Mar. 24, 2020; and application No. 2020-053002 (JP), filed on Mar. 24, 2020.
Prior Publication US 2024/0092645 A1, Mar. 21, 2024
Int. Cl. C01B 33/18 (2006.01); C09C 1/30 (2006.01)
CPC C01B 33/18 (2013.01) [C09C 1/3054 (2013.01); C09C 1/3081 (2013.01); C01P 2004/64 (2013.01); C01P 2006/16 (2013.01)] 13 Claims
 
1. Silica particles containing a quaternary ammonium salt, wherein the silica particles satisfy the following expression
CAFTER/CBEFORE≤1.5,
as measured by:
adhering the silica particles, before or after washing, to surfaces of resin particles to obtain silica-adhered resin particles,
mixing the silica-adhered resin particles with a ferrite powder to form a mixture,
separating the silica-adhered resin particles from the mixture, and
measuring the electrostatic capacitance of the silica-adhered resin particles,
wherein:
CAFTER represents the measured electrostatic capacitance of the silica-adhered resin particles in which the silica particles after washing are adhered to the surfaces of the resin particles, and
CBEFORE represents the measured electrostatic capacitance of the silica-adhered resin particles in which the silica particles before washing are adhered to the surfaces of the resin particles.