Endurable water-repellent glass for automobiles

Endurable water-repellent coated layers have been formed on safety glasses for automobiles via a sol-gel based spray coating process. Coated films are composed of a silica underlayer( similar to 800 Angstrom) and a fluorocarbon layer in which the formed silica shows a definite surface roughness and acts as the enhancement factor for chemical and mechanical durability. Durability is a function of the degree of surface roughness, structural fineness and homogeneity. Dual stage aging in silica sol controls a nide range of surface roughness. Water-repellency is degraded gradually by a combination of sunlight (ultraviolet), water, and abrasion. Spray coating on large size and curved safety glasses was successfully carried out.