METHOD FOR PREPARING SILICA SOLUTION, POLISHING LIQUID CONTAINING SILICA SOLUTION PREPARED BY THE METHOD FOR PREPARING SILICA SOLUTION, AND METHOD FOR MANUFACTURING GLASS SUBSTRATE FOR MAGNETIC RECORDING MEDIUM USING THE POLISHING LIQUID

摘要

PROBLEM TO BE SOLVED: To provide: a method for preparing a silica solution, which efficiently removes foreign matter from a silica solution containing silica particles whose primary particle diameter is 1-80 nm; a polishing liquid containing a silica solution freed of foreign matter; and a method for manufacturing a glass substrate for a magnetic recording medium, which includes a polishing step using the polishing liquid.;SOLUTION: This method for preparing a silica solution removes foreign matter from a silica solution containing silica particles whose primary particle diameter is 1-80 nm, wherein the particle diameter D_p of the foreign matter to be removed is confined to 0.1-1 μm by controlling centrifugal acceleration G, the ratio of settling distance to settling time, namely h/t, and the viscosity η of the solution. The polishing liquid used for polishing the principal plane of a glass substrate for a magnetic recording medium contains a silica solution prepared by the method for preparing a silica solution, wherein the particle diameter D_p of foreign matter to be removed is confined to 0.1-1 μm. The method for manufacturing a glass substrate for a magnetic recording medium includes a step of polishing the principal plane of a glass substrate using the polishing liquid.;COPYRIGHT: (C)2013,JPO&INPIT