| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for manufacturing a silica sol capable of manufacturing a high-purity silica sol consisting of spherical particles having an average diameter of 5-100 nm according to the nitrogen adsorption method, accompanied by scarce internal micropores, and excellent in terms of hygroscopicity resistance.SOLUTION: Ammonia or an alkylamine having a boiling point of 100°C or less is used as a hydrolysis catalyst. The initial concentration of the hydrolysis catalyst with respect to 1 L of a reaction medium is confined to 0.02-1.0 mole. A silicon alkoxide is added to the reaction medium in a state where the water concentration of the reaction medium is being maintained at 80 mol% or above and where the molar ratio of the hydrolysis catalyst with respect to the total addition sum of silicon (hydrolysis catalyst/silicon) is 0.15 or above. The silicon alkoxide is hydrolyzed at 60°C or above and below the boiling point of the reaction medium. |
