Abstract: A method for forming a titanium oxide film that can be formed on a surface of a base material without a heating step. In Step 0, a surface of a molded product (base material) composed of a cyclic olefin-based resin is irradiated with ultraviolet light in an air atmosphere. In Step 1, the base material is immersed in a mixed liquid of an aqueous solution of titanium chloride and a nitrite ion-containing aqueous solution. A titanium oxide film grows by repeating oxidation of a titanium ion. In Step 2, the base material is pulled out from the mixed liquid, and then washed to stop the reaction. The film thickness can be controlled by controlling this immersion time. In Step 3, the base material after washing is dried at room temperature.

Abstract: In a method for forming a titanium oxide film, with which a titanium oxide film can be formed on a surface of a glass base material, a surface of a molded product composed of a glass is irradiated with ultraviolet light in an air atmosphere in step 0. In Step 1, the base material is immersed in a mixed liquid of an aqueous solution of titanium chloride and a nitrite ion-containing aqueous solution. As a result of the immersion, a titanium oxide film is grown by repeating oxidation of a titanium ion, binding of the oxidized titanium ion to oxygen, and binding of the bound oxygen to a titanium ion at the cleaved end of the glass molded product. In Step 2, the base material is pulled out from the mixed liquid, and then washed to stop the reaction. The film thickness can be controlled by controlling the immersion time.

Abstract: A method for forming a titanium oxide film that can be formed on a surface of a base material without a heating step. In Step 0, a surface of a molded product (base material) composed of a cyclic olefin-based resin is irradiated with ultraviolet light in an air atmosphere. In Step 1, the base material is immersed in a mixed liquid of an aqueous solution of titanium chloride and a nitrite ion-containing aqueous solution. A titanium oxide film grows by repeating oxidation of a titanium ion. In Step 2, the base material is pulled out from the mixed liquid, and then washed to stop the reaction. The film thickness can be controlled by controlling this immersion time. In Step 3, the base material after washing is dried at room temperature.