SURFACE TREATING AGENT AND FORMATION OF INORGANIC HYDROPHILIC FILM

摘要

PROBLEM TO BE SOLVED: To obtain an inorganic hydrophilic film having high hardness and excellent durability, by coating the surface of a substrate with a surface treating agent comprising a solution composed of P, Al, Si, water and a dihydric alcohol and heat-treating the substrate in a specific temperature range to form the inorganic hydrophilic film. ;SOLUTION: Phosphoric acid and Al(NO₃)₃.9H₂O in amounts of 0.02-2mol/L calculated as P₂O₅ and Al₂O₃, respectively and in the molar ratio of Al₂O₃/P₂O₅ of 2/8 to 8/2 are dissolved in water to give an aqueous solution, to which lithium silicate, etc., in an amount 0.05-4mol/L calculated as SiO₂ in the ratio of (Al₂ O₃+P₂O₅)/SiO₂=2/8 to 8/2 is added to give a mixture. The mixture is mixed with water and a 2-7C dihydric alcohol such as ethylene glycol in the volume ratio of the alcohol/water of 0.5-10 to prepare a hydrophilic surface treating agent. Then the surface treating agent is applied to a substrate such as a glass plate, which is predried and heat-treated at 200-700°C and a coated film is obtained to give the objective smooth surface-treated glass plate.;COPYRIGHT: (C)1998,JPO