| 摘要 |
Disclosed is a synthetic amorphous silica powder, which is obtained by subjecting a silica powder to spheroidizing treatment and then cleaning and drying the resulting silica powder, and which has an average particle diameter D50 of 10-2,000 µm. The synthetic amorphous silica powder is characterized by having a value, which is obtained by dividing the BET specific surface area by the theoretical specific surface area as calculated from the average particle diameter D50, of 1.00-1.35, a true density of 2.10-2.20 g/cm3, an intramolecular porosity of 0-0.05, a circularity of 0.75-1.00, and an undissolved ratio of 0.00-0.25. Since the amount of gas components adsorbed on the surface of the synthetic amorphous silica powder or contained in the powder is little, a synthetic silica glass product that is produced using the powder can be greatly reduced in generation or expansion of gas bubbles even when used in a high temperature and reduced pressure environment. |
