BORON-CONTAINING SILICA DISPERSION, AND METHOD FOR PRODUCING SAME

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.