PROCESS FOR PRODUCING FUNCTIONAL COLLOIDAL SILICA SOLUTION, ULTRAVIOLET-CURABLE RESIN COMPOSITION FOR HARD COATS USING SAME, AND CURED PRODUCT THEREOF

摘要

The present invention provides a process for producing a functional colloidal silica capable of yielding a ultraviolet-curable hard coat material which combines hardness and low cure shrinkage and which ensures excellent scratch resistance, tight adhesion and economical efficiency. A process for producing a functional colloidal silica solution which is obtained by subjecting (A) 100 parts by weight (in terms of silica) of a water-dispersible colloidal silica that has a mean particle diameter of 1 to 30nm and a hydrogen ion concentration (pH) of 6 or less, (B) 20 to 30 parts by weight of a methacryloxy-containing alkoxysilane and (C) 50 to 500 parts by weight of a polar solvent having a dielectric constant of 10 or more to hydrolysis in the presence of (D) 0.001 to 1 part by weight of (D) a radical polymerization inhibitor, and then subjecting the resulting system to azeotropic dehydration/ solvent displacement using (E) 1-methoxy-2-propanol and which exhibits a mean particle diameter of 1 to 30nm and an at most 1.5-fold difference in the mean particle diameter of the silica between before and after the hydrolysis.