COATING FLUID APPLICABLE BY HAND FOR SOL-GEL FILM FORMATION

摘要

A coating fluid for obtaining sol-gel films which comprises a solid matter and a solvent. The solid matter includes a silicon oxide oligomer obtained by subjecting an alkoxysilane to hydrolysis and condensation polymerization in an acid aqueous solution. The solvent comprises an organic solvent having a boiling point of 100°C or higher and a viscosity of 3.5 mPa s or lower and the acid aqueous solution. The silicon oxide oligomer has a number-average molecular weight of 500-4,000 in terms of polystyrene. The content of the solid matter in the coating fluid is 8-30 wt.%. The content of the silicon oxide oligomer in the solid matter is 10 wt.% or higher. Even when applied by a coating technique necessitating no apparatus, such as hand application, the coating fluid can form a sol-gel film having satisfactory quality with respect to hardness, appearance including transparency, perspective distortion, film thickness, etc.