JPH0367978B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for producing glass coated with a titanium oxide film, and more particularly to a method for forming a titanium oxide film on a glass surface by utilizing a precipitation phenomenon in the liquid phase. BACKGROUND OF THE INVENTION Conventionally, glass has been coated with metal oxides to impart desired optical or electrical properties to the glass. Among them, titanium oxide film has a high optical reflectance due to its high refractive index, and its reflection color is a beautiful silver tone, so it has recently come to be widely used as heat ray reflective glass. Furthermore, utilizing the chemical stability of the titanium oxide film, it is also attracting attention to use it as a protective film or an insulating film for other films formed on the glass surface. The methods for producing glass coated with titanium oxide film include the spray method, in which a solution containing organic titanium compounds such as titanium acetylacetonate and titanium octylene glycol is sprayed onto the high-temperature glass surface to form a film; The CVD method, in which a film is formed by spraying titanium vapor, or the dip coating method, in which the glass is immersed in a solution containing titanium isopropoxide, etc., pulled up, and then heated to a high temperature to form a film, are known. It is being However, with these methods, it is difficult to uniformly form a titanium oxide film on a large area of glass. Although various efforts have been made to prevent ripples and other aspects, uneven thickness remains a major problem. Furthermore, ignition of vapors from organic solvents or titanium compounds and deterioration of the working environment were also serious problems. In view of this problem, the present invention provides a new method for producing glass coated with a titanium oxide film, in which 0.4 mole of boric acid is added to an aqueous solution saturated with zinc oxide containing 1.0 mole or less of titanium hydrofluoric acid.
When 1.0 mol to 1.0 mol of titanium oxide is added, the glass is immersed to produce titanium oxide film-coated glass. In the present invention, titanium hydrofluoric acid is diluted with water, and its concentration is adjusted to 1.0 mol/or less. When the concentration of titanium hydrofluoric acid exceeds 1.0 mol/cm, a titanium oxide film is not formed or
The disadvantage is that the formation speed is slow and the formation rate is slow. In particular, the concentration of titanium hydrofluoric acid should be adjusted from 0.3 to 1.0 mol/
If this is done, the titanium oxide film formed will be formed at a faster rate and will have a higher density. The titanium hydrofluoric acid aqueous solution suitably prepared as described above is saturated with zinc oxide and stored at a temperature below 40°C. In addition, in the present invention, the optimum amount of boric acid to be added to a saturated aqueous solution of zinc oxide containing titanium hydrofluoric acid changes depending on the concentration of titanium hydrofluoric acid, and if this amount is too small, the glass will be etched. If the amount is too large, fine crystals of titanium oxide will precipitate in the solution, making the solution cloudy, and in either case, no titanium oxide film will be formed on the glass surface. The concentration of titanium hydrofluoric acid is 1.0 mol/
In the following cases, the amount of boric acid added is 0.4 to 1.0 mol/
, particularly preferably from 0.4 to 0.75 mol/. A uniform titanium oxide film can be formed on the glass surface after 3 hours of contacting or immersing the glass in a saturated solution of zinc oxide containing titanium hydrofluoric acid and boric acid at the above concentrations. The titanium oxide film-coated glass produced in this way is usually heated at a temperature of 300 to 600°C, preferably 500 to 550°C.
The adhesion strength of the titanium oxide film is strengthened by heating and baking at ℃ for 10 minutes or more. Examples and comparative examples of the present invention will be described in detail below. Add 400 g of zinc oxide powder to aqueous solution 1 containing titanium hydrofluoric acid at a concentration of 3 mol/h and stir.

【table】

[Table] After that, remove undissolved zinc oxide using filter paper,
Divide the filtrate into four parts, add water to each part, and adjust the titanium hydrofluoric acid concentration to 3.0, 2.0, 1.0, and
Four solutions of 0.3 mol/ml were prepared. The concentration of this titanium hydrofluoric acid is 3.0, 2.0, 1.0 and
Divide 0.3 mol of each solution into 3 to 6 equal parts, immerse a glass with a thickness of 2 mm and a size of 20 mm x 50 mm in each solution, then add boric acid in the amount shown in Table 1 and maintain it at 40 ° C. After a period of time, the glass sample was removed from the immersion liquid. Thereafter, the glass sample was washed with water and dried in a hot air circulating dryer at 120°C. The thickness of the formed titanium oxide film was measured using Talysurf, and the results of observation of the solution are shown in Table 1. As is clear from Table 1, when using the comparative example, a titanium oxide film could not be formed on the glass surface or the glass surface was etched, but according to the present invention, a titanium oxide film with a uniform thickness was formed on the glass surface. It can be seen that a film can be formed.

Claims (1)

[Claims] 1 Into an aqueous solution saturated with zinc oxide containing 1.0 mol or less of titanium hydrofluoric acid (H ₂ TiF ₆ ),
A method for producing glass coated with a titanium oxide film by adding 0.4 to 1.0 mol of boric acid per unit and immersing the glass.