US 12,459,827 B2
Method for producing spherical silica particles
Yusuke Watanabe, Miyoshi (JP)
Assigned to ADMATECHS CO., LTD., Miyoshi (JP)
Filed by ADMATECHS CO., LTD., Miyoshi (JP)
Filed on Feb. 26, 2025, as Appl. No. 19/063,744.
Application 19/063,744 is a continuation of application No. PCT/JP2022/032669, filed on Aug. 30, 2022.
Prior Publication US 2025/0197226 A1, Jun. 19, 2025
This patent is subject to a terminal disclaimer.
Int. Cl. C01B 33/18 (2006.01); C01B 33/187 (2006.01)
CPC C01B 33/18 (2013.01) [C01B 33/187 (2013.01); C01P 2004/03 (2013.01); C01P 2004/34 (2013.01)] 7 Claims
OG exemplary drawing
 
1. A method for producing spherical silica particles, the method comprising:
a raw material silica particle preparation step of preparing a liquid dispersion of raw material silica particles from a raw material solution obtained by dissolving silicic acid in a mixed solvent of water and an organic solvent in the presence of a basic substance formed from at least one of a quaternary ammonium and a base having a cyclic amidine structure; and
a heating step of heating the liquid dispersion or the raw material silica particles obtained from the liquid dispersion through solid-liquid separation so as to remove an organic substance contained in the liquid dispersion, thereby preparing spherical silica particles, wherein
the mixed solvent has a relative permittivity of 21 or higher and 40 or lower, and
the basic substance is blended in a blending ratio of 0.3 or higher and 0.8 or lower in terms of molar ratio with respect to a silicon element derived from the silicic acid.