Water-repellent metal oxide film and method of forming same on glass substrate

摘要

The invention relates to a multilayered metal oxide film formed on a glass substrate by the sol-gel process. The film has a first metal oxide layer formed on the glass substrate and a second metal oxide layer formed on the first layer. To make the first layer minutely rough, at least two sols are respectively prepared from at least one compound selected from the group consisting of metal alkoxides and metal acetylacetonatos, such that polymers of the sols have different average molecular weights. Then, the at least two sols are mixed with a solvent so as to prepare a first coating solution. The first coating solution is applied to the glass substrate so as to form thereon a first sol film. The thus coated glass substrate is heated so as to transform the first sol film into the first metal oxide layer. To form a water-repellent metal oxide film on the first layer, a silane compound containing a fluorocarbon group is mixed with a solvent so as to prepare a second coating solution. After that, the second coating solution is applied to the first metal oxide layer so as to form thereon a second sol film. Then, the glass substrate is heated so as to transform the second sol film into the second metal oxide layer which is water-repellent.