METHOD FOR PRODUCING SILICA-BASED FINE PARTICLE-DISPERSED SOL, SILICA-BASED FINE PARTICLE-DISPERSED SOL, COATING COMPOSITION CONTAINING SILICA-BASED FINE PARTICLE-DISPERSED SOL, CURABLE COATING FILM, AND BASE WITH CURABLE COATING FILM

摘要

PPROBLEM TO BE SOLVED: To provide a silica-based fine particle-dispersed sol which is stable in the acidic region of pH 3.0-6.0, and has excellent stability and transparency in a coating composition and a coating film obtained by the coating composition. PSOLUTION: The method for producing the silica-based fine particle-dispersed sol comprises (1) a step in which an aqueous solution of an aluminate is mixed into an alkaline silica sol that contains water-dispersible silica fine particles and has a pH within the range of 9.0-11.5 at such a ratio that the molar ratio (AlSB2/SBOSB3/SB/SiOSB2/SB) is 0.005-0.050 when the silicon content contained in the silica sol is represented by SiOSB2/SBand the aluminum content contained in the aluminate is represented by AlSB2/SBOSB3/SB, (2) a step in which the liquid mixture obtained in the step (1) is heated to a temperature of 60-200C and stirred for 0.5-20 hours, and (3) a step in which the alkali metal ions contained in the liquid mixture are removed by ion exchange by bringing the liquid mixture obtained in the step (2) into contact with a cation-exchange resin, thereby adjusting the pH of the liquid mixture within the range of 3.0-6.0. PCOPYRIGHT: (C)2011,JPO&INPIT