TRANSPARENT INORGANIC-ORGANIC HYBRID MATERIALS VIA AQUEOUS SOL-GEL PROCESSING

摘要

A sol to form an inorganic-organic hybrid coating having a thick highly transparent hard coating is described. The hybrid coating is formed from a combined aqueous sol with at least one hydrolyzable silane and at least one hydrolyzable metal oxide precursor where the only organic solvents present are those liberated upon hydrolysis of the silanes and metal oxide precursors. In one embodiment an inorganic-organic hybrid coating is formed by combination of a sol, prepared by the hydrolysis of tetraethoxysilane and ?-glycidoxypropyltrimethoxysilane with an excess of water, and a sol, prepared by the hydrolysis of titanium tetrabutoxide and ?-glycidoxypropyltrimethoxysilanc with a deficiency of water. A plastic substrate can be coated with the combined sol and the combined sol gelled to a thickness of at least 5 µm with heating to less than 150 °C.