PROCESS FOR PRODUCTION OF SILICA-ALUMINA SOL SILICA-ALUMINA SOL COATING AGENT FOR FORMATION OF TRANSPARENT COATING FILM WHICH COMPRISES THE SOL AND SUBSTRATE HAVING TRANSPARENT COATING FILM ATTACHED THERETO

摘要

A silica-alumina sol which is stable even at a high concentration and has good dispersibility into a matrix component, and a process for producing the same. Silica-alumina particles obtained by removing cations (alkali metal ions) present in the silica-alumina sol derived from the raw material for production and reducing the amount of boron ions and adjusting the surface negative charge amount to a predetermined range are used, The compound is preliminarily adsorbed on the surface of the particle, and the surface is hydrolyzed.