US 12,286,356 B2
Colloidal silica and method for producing same
Yuma Negishi, Fukuchiyama (JP); Hideki Otsuki, Fukuchiyama (JP); Hiroaki Yamashita, Fukuchiyama (JP); and Toshiki Chiba, Fukuchiyama (JP)
Assigned to FUSO CHEMICAL CO., LTD., Osaka (JP)
Appl. No. 17/436,126
Filed by FUSO CHEMICAL CO., LTD., Osaka (JP)
PCT Filed Feb. 26, 2020, PCT No. PCT/JP2020/007579
§ 371(c)(1), (2) Date Sep. 3, 2021,
PCT Pub. No. WO2020/179556, PCT Pub. Date Sep. 10, 2020.
Claims priority of application No. 2019-040718 (JP), filed on Mar. 6, 2019.
Prior Publication US 2022/0144649 A1, May 12, 2022
This patent is subject to a terminal disclaimer.
Int. Cl. C01B 33/145 (2006.01)
CPC C01B 33/145 (2013.01) [C01P 2004/03 (2013.01); C01P 2004/64 (2013.01); C01P 2006/10 (2013.01)] 9 Claims
 
1. A colloidal silica comprising silica particles, wherein
the silica particles have an average primary particle size of 33 nm or more, an aggregation ratio of 1.2 or more, and a particle density of 1.95 or more,
the silica particles contain 1000 ppm by mass or more of alkoxy groups per gram of the silica particles,
the proportion of the number of silica particles having an equivalent circle diameter under 20 nm is less than 15%, and
the silica particles contain a primary amine in an amount of 5 μmol or more per gram of the silica particles.