Patent ID: 9550683
Date: 2017-01-24
CPC Classifications: C01B,C09K

Claim:
1. A method for producing a colloidal silica, comprising the steps of: 1) preparing a mother liquid comprising an alkali catalyst and water; 2) separately preparing a hydrolyzed liquid by hydrolyzing tetramethyl orthosilicate in the absence of a catalyst; and 3) after steps 1) and 2), adding, to the mother liquid, the hydrolyzed liquid to produce the colloidal silica wherein the hydrolyzed liquid is added to the mother liquid at a rate of not less than 0.7 g of silica/hour/kg of mother liquid and not greater than 41 g of silica/hour/kg of mother liquid; and a) with respect to a sample prepared by adding, as an internal standard, 1 wt. % of polydimethylsilane to a dried product of the colloidal silica, a peak area value calculated using a formula of a colloidal silica peak area/a polydimethylsilane peak area is 15 or less, the peak areas being determined by measuring a solid-state b) each amount of