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 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 γ-glycidoxypropyltrimethoxysilane with an excess of water, and a sol, prepared by the hydrolysis of titanium tetrabutoxide and γ-glycidoxypropyltrimethoxysilane 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.

主权项

1. A sol for the preparation of an inorganic-organic hybrid coating comprising:
a combined sol comprising:
a first sol comprising a partially condensed mixture of a hydrolyzable silane containing at least one polymerizable organic group and a hydrolyzable metal oxide precursor and less than a stoichiometric amount of water; anda second sol comprising at least one hydrolyzable silane, wherein one of the at least one hydrolyzable silanes is the hydrolyzable silane containing at least one polymerizable organic group and a greater than stoichiometric amount of water, wherein said combined sol is free of organic solvents in excess of those formed upon hydrolysis in the first sol and the second sol.