Multilayered water-repellent film and method of forming same on glass

Abstract

The invention relates to a multilayered water-repellent film formed on a glass substrate by the sol-gel process. The film has a first metal oxide layer which is formed on the glass substrate by the sol-gel process and a second water-repellent layer formed on the first layer. As a first method for providing the film with superior durability of water repellency, mechanical strength and chemical resistance, the first layer is prepared by using a mixture of three specific sols which are respectively prepared from metal alkoxides or metal acetylacetonates. As a second method for providing the film with the above advantages, the second layer is prepared by using a coating mixture comprising a fluoroalkylsilane, tin oxide particles doped with antimony oxide, a silicon compound, water and an organic solvent. As a third method for providing the film with the above advantages, the second layer is prepared by using another coating mixture comprising a fluoroalkylsilane, tin oxide particles doped with antimony oxide, a silicon compound, water, an organic solvent and an acid.