To provide
colloidal silica in a single nano-size or a
small particle size close to the single nano-size, in which its agglomeration does not substantially occur, and a method of producing the same.SOLUTION: The
colloidal silica is characterized by being
surface modified, having a BET
diameter of not larger than 12 nm, and being not substantially agglomerated. The method of producing the
colloidal silica is characterized by including a
raw material preparation step of supplying easily decomposable organo-
silicate to a reaction liquid including a
hydrolysis catalyst consisting of an organic amine to make the organo-
silicate react with the reaction liquid, to prepare
raw material colloidal silica having a BET
diameter of not larger than 12 mn, a concentration adjustment step of adjusting the
solid content concentration of the
raw material colloidal silica to not greater than 13
mass% and adjusting the concentration of the
alcohol formed in the raw material preparation step to 1 to 25
mass%, a modification step of modifying the raw material colloidal silica of which concentration has been adjusted, and a concentration step of concentrating the content of residual
organic solvent in the colloidal silica which has been modified, to be not greater than 1
mass%.SELECTED DRAWING: Figure 1