BORON-CONTAINING SILICA DISPERSION, AND METHOD FOR PRODUCING SAME

    公开(公告)号:US20240002240A1

    公开(公告)日:2024-01-04

    申请号:US18247010

    申请日:2021-09-21

    IPC分类号: C01B33/141

    摘要: The present invention provides a boron-containing silica dispersion having better dispersion stability at a high concentration, and higher binding properties between boron and silica than conventional dispersions. The present invention is a boron-containing silica dispersion containing amorphous silica particles containing boron atoms and a dispersion medium; the boron-containing amorphous silica particles having an average particle size of 10 to 100 nm, as determined from 40 particles selected at random in a transmission electron micrograph; the boron-containing silica dispersion having a solids content of 5 to 30 mass %; and the boron-containing silica dispersion having a sedimentation rate of the particles of 4% or less, when the boron-containing silica dispersion is left standing for 1000 hours, and proportions of SiO2 and B2O3 of 90.0 to 99.8 mass % and 0.2 to 10.0 mass %, respectively, in 100 mass % of a total of SiO2 and B2O3, all terms of oxide, when the boron-containing silica dispersion is subjected to ultrafiltration by the following method and dried; washing is performed by sequentially adding pure water in an amount of 6 times the volume of the boron-containing silica dispersion at a flow rate of a liquid fed of 3660 ml/minute using an ultrafiltration membrane with a fraction molecular weight of 13,000.

    Method for producing barium titanate powder

    公开(公告)号:US09771274B2

    公开(公告)日:2017-09-26

    申请号:US15037250

    申请日:2014-08-22

    IPC分类号: C01G23/00 H01G4/12 H01G4/30

    摘要: The invention provides a method for producing barium titanate powder comprising the steps of: adding an aqueous slurry of anatase hydrous titanium oxide having a BET specific surface area in the range of 200 m2/g to 400 m2/g and a half width of diffraction peak of (101) plane in the range of 2.3° to 5.0° as measured by X-ray diffraction to an aqueous solution of barium hydroxide while maintaining the aqueous solution of barium hydroxide at a temperature in the range from 80° C. to the boiling point thereof under normal pressure to cause a reaction of the barium hydroxide with the hydrous titanium oxide to provide an aqueous slurry of barium titanate precursor; and subjecting the barium titanate precursor thus obtained to hydrothermal treatment over a period of not less than 24 hours to provide barium titanate particles.