Spherical silica particles

Abstract

The present invention addresses the problem of providing a novel method for producing spherical silica particles having fine voids. The present invention has been completed on the basis of the insight that spherical silica particles having fine voids therein can be produced using an aqueous alkaline silicic acid solution as a starting material. Namely, the spherical silica particles according to the present invention have an average particle diameter of 0.1-10.0 [mu] m, a true specific gravity of 0.9-1.9 g / cm3 as measured by nitrogen gas, a pore volume of 0.1 mL / g or less, a Na content of 10 ppm or less, and a true specific gravity retention rate of 80% or more as measured by nitrogen gas before and after being pressurized at 300 MPa for 1 minute, and each particle has an average particle diameter of 0.1-10.0 [mu] m, a pore volume of 0.1 mL / g or less, and a Na content of 10 ppm or less as measured by nitrogen gas. The present ratio of particles in which the maximum value of the major diameter of internal voids is equal to or greater than half of the major diameter of the particles is 60% or less, and is mainly composed of silica.

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