JPH04263080A - Production of ultraviolet cutoff filter - Google Patents

Abstract

PURPOSE:To produce a UV cutoff filter capable of selectively and efficiently cutting off only the UV of 300-400nm on a transparent substrate of glass, etc. CONSTITUTION:Water is added to a mixed soln. contg. an organotitanium compd., a cerium compd. and an org. compd. contg. at least one hydroxyl group and at least one ketonic group, and the soln. is converted to a sol. The liq. reactant is applied on a transparent substrate and sintered.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing an ultraviolet cut filter, particularly an ultraviolet cut filter formed on a transparent substrate such as glass.

0002

[Prior Art] Conventional methods for manufacturing ultraviolet cut filters include a method in which multiple layers of substances with different refractive indexes are alternately laminated on a transparent substrate such as glass, a method in which thin films are formed by vapor deposition of metals or metal oxides, etc. A method is known in which a UV absorber is dissolved or dispersed in some kind of binder and then applied.

[0003] Furthermore, JP-A-63-103083 discloses that an acid is added to a mixed solution of titanium alkoxide and a cerium compound to adjust the pH to 3.5 to 5, and the water content in the total solution is adjusted to 8% or less. A method is disclosed in which this mixed solution is applied to the surface of a substrate and then heated to 200° C. or higher to form a film of cerium-containing titanium oxide.

0004

[Problems to be Solved by the Invention] However, in such conventional methods, for example, those using vapor deposition, the throughput is small and the reaction chamber is small, so only a filter with a small area can be produced, resulting in high costs. There was a problem. Furthermore, the method of dissolving or dispersing an ultraviolet absorber in some kind of binder and applying the same has the problem that absorption at a preferable wavelength cannot be obtained depending on the type of binder or ultraviolet absorber.

Furthermore, the method disclosed in JP-A-63-103083 has absorption in the visible light range of 400 nm or more, and also cuts part of the visible range, making it impossible to cut only ultraviolet rays. There is a problem. Further, there are problems in that it is difficult to control pH and water content, the pot life of the mixed liquid is short, and the film devitrifies, making it impossible to form a transparent film.

[0006] The object of the present invention is to
An object of the present invention is to provide a method for manufacturing a filter that selectively and efficiently cuts only ultraviolet rays.

Still another object of the present invention is to provide a p
It is an object of the present invention to provide a method for manufacturing an inexpensive, large-area, transparent ultraviolet cut filter that does not require control of H or moisture content.

[0008]

[Means for Solving the Problems] The above objects of the present invention are as follows:
Water is added to a mixed solution containing an organometallic compound of titanium, a cerium compound, and an organic compound containing at least one hydroxyl group and at least one ketone group to form a sol, and this reaction solution is applied on a transparent substrate, This was achieved by a sintering method.

The present invention will be explained in detail below.

In the present invention, water is added to a mixed solution containing an organometallic compound of titanium, a cerium compound, and an organic compound containing at least one hydroxyl group and at least one ketone group to form a sol, and this reaction solution is It is characterized by being applied onto a glass substrate and sintered.

The method of adding water to such a mixed solution to solify metal ions is generally referred to as a sol-gel method.

A method for forming a thin film by the sol-gel method is described, for example, in "Glass/Ceramics Manufacturing Technology by the Sol-Gel Method and Its Applications" (edited by Masayuki Yamane, Oyo Gijutsu Shuppan, 1989), pages 108 to 140. For example, titanium tetramethoxide is dissolved in methanol. To this, an acid such as hydrochloric acid and a decomposing agent for titanium tetramethoxide such as water are added. Titanium tetramethoxide decomposes to form a sol having Ti-O-Ti bonds. By appropriately selecting the viscosity, it can be applied by any means to form a thin film. The coating method is selected from dipping, spin coating, spraying, and the like. Then, it is sintered.

The titanium organometallic compound used in the present invention is preferably titanium alkoxide. Titanium alkoxide is represented by the general formula Ti(OR)n. Here, n is an integer and represents the coordination number with respect to titanium. R is selected from any alkyl group. Examples of R include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, and the like.

As the cerium compound, inorganic cerium compounds such as cerium nitrate, cerium chloride, and cerium sulfate are preferably used.

The organic compound containing at least one hydroxyl group and at least one ketone group is generally referred to as hydroxyketone, and preferred are acetoalcohol, acetoin, diacetone alcohol, benzoin, and the like.

In the present invention, water is added to form a sol of metal ions, but the amount of water may be arbitrary. Preferably, the molar amount is 1 to 10 times that of the metal ion. Furthermore, an acid may be added when forming a sol. Preferred acids include nitric acid, hydrochloric acid, acetic acid, and sulfuric acid. Although the reaction temperature may be arbitrary, it is preferably 50 to 130°C. The solvent may be any solvent as long as these compounds can be dissolved therein, but alcohols such as ethyl alcohol, propyl alcohol, and butyl alcohol, and glycol ethers such as ethyl cellosolve and methyl cellosolve are preferably used. The mixing ratio of the titanium organometallic compound and the cerium compound is Ti:Ce=1 in molar ratio.
:5 to 100:1 is preferable. In addition, the organic compound containing at least one hydroxyl group and at least one ketone group should be used in an amount of 1/10 to 10 times the total number of moles of the organic metal compound of titanium and the cerium compound as titanium and cerium metal. It is preferable to add it, and it is more preferable to add it in moles equal to the above total number of moles. Sintering should be at a temperature that removes organic compounds, preferably 200° C. or higher. Further, the temperature should be such that the substrate does not deform or change in quality, and in the case of the present invention, the temperature is preferably 700° C. or less. Heating time may be 5 to 60 minutes.

The thin film used in the present invention must be laminated in at least one layer, and may be coated in two or more layers to increase absorbance. The lamination method may be to apply one layer and then apply another layer, or to apply another layer after sintering. The substrate to be coated may be any transparent substrate, but is preferably selected from glass substrates such as soda lime, quartz substrates, and plastic substrates such as polycarbonate.

[0018]

According to the present invention, a filter can be obtained which selectively and efficiently cuts only ultraviolet rays of 300 to 400 nm. Furthermore, it is possible to obtain a large-area filter at low cost.
It is easy to manufacture, does not require control of pH or water content, and provides a transparent filter.

[0019]

【Example】

The present invention will be further explained below with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples.

Comparative Example 1.26 g of cerium chloride was dissolved in 30 cc of ethanol. To this solution, 1 cc of titanium tetraisopropoxide was added at room temperature, and then 1 cc of 30% acetic acid was added.
H was set to 4. This solution was applied onto soda lime glass using a spinner. Spinner application conditions are 3000
rpm for 30 seconds. After drying the coated sample in the air, it was placed in an electric furnace and sintered at 500°C for 10 minutes. The yellow glass obtained was devitrified. The absorbance of this glass sample is shown on an arbitrary scale in FIG. 2, using glass as a reference. It had an absorption maximum at 440 nm and absorption in the visible range. Furthermore, this solution was added at room temperature for 1
When left for a week, it became cloudy and coating was impossible.

Example 1 1.26 g of cerium chloride was dissolved in 30 cc of ethanol. 1 cc of titanium tetraisopropoxide was added to this solution, and 0.8 cc of diacetalcohol was added.
ml was added, and the mixture was stirred and heated at 80°C for 1 hour. After cooling to room temperature, add 0.12 ml of water and 0.0 ml of 61% nitric acid.
4 ml was added, and the mixture was stirred and heated at 80°C for 1 hour. The pH at this time was 1. After cooling this solution to room temperature, it was applied onto soda lime glass using a spinner. The spinner coating conditions were 300 rpm and 30 seconds. After drying the coated sample in the air, it was placed in an electric furnace and heated for 50 minutes.
Sintering was performed at 0°C for 10 minutes. The obtained glass sample was colorless and transparent. The absorbance of this glass sample is shown in FIG. 1 in the same manner as in FIG. 2, using glass as a reference. It was found that the absorption maximum is at 330 nm and that it blocks ultraviolet rays of 300 to 400 nm.

[0023] Further, this reaction solution was left for one week at room temperature. The reaction solution was transparent and could be coated. The glass coated sample showed the same absorbance as above.

Example 2 1.47 g of cerium nitrate was used instead of cerium chloride in Example 1, and 1.1 g of titanium tetra-n-butoxide was used instead of titanium tetraisopropoxide.
A glass sample was prepared in the same manner as in Example 1, except that 0.53 ml of acetoin was used instead of diacetone alcohol. The absorbance of the obtained glass sample was similar to that of Example 1, and showed that ultraviolet rays of 300 to 400 nm were blocked.

Example 3 The amount of water in Example 1 was changed from 0.12 ml to 0.2 ml.
The amount was changed to 0.5, 0.6 ml. It was coated and sintered in the same manner as in Example 1. 300 to 400n as in Example 1
It was blocking ultraviolet rays. Further, this reaction solution was left at room temperature for one week. The solution was clear and coatable. The coated glass sample showed similar absorbance as above.

Example 4 Using 35% hydrochloric acid instead of nitric acid in Example 1,
The amount is 0.1, 0.3, 0.6, 0.8, 1.
The volume was changed to 0 ml. The pH of the solution at this time is 3.0
It was 0.1. A coated sample was prepared in the same manner as in Example 1. The absorbance of the obtained sample was the same as in Example 1, which blocked ultraviolet rays of 300 to 400 nm.

Example 5 Cerium acetate 1 was used instead of cerium chloride in Example 1.
．． Using 5 g of titanium tetraisopropoxide, 1.6 g of titanium tetraethoxide was used instead of titanium tetraisopropoxide, 1.3 ml of benzoin was used instead of diacetone alcohol, and the solvent was changed to ethanol and n-butanol 100
Coating was carried out in the same manner as in Example 1 except that the volume was changed to ml. The absorbance of the obtained sample was 300 to 400 as in Example 1.
It blocks ultraviolet rays of nanometers.

Example 6 A coated sample was prepared in the same manner as in Example 1 except that quartz glass was used instead of soda lime glass in Example 1. The absorbance of the obtained sample was such that ultraviolet rays of 300 to 400 nm were blocked.

Example 7 Instead of spinner coating in Example 2, a dip coating method was used, and the size of the glass substrate was 500 mm x 50 mm.
A glass coating sample was prepared in the same manner as in Example 2, except that the thickness was 0 mm x 3 mm. Application is uniform, 300
It blocks ultraviolet rays of ~400 nm.

(Effects of the Invention) As detailed above, according to the present invention, it is possible to provide a filter that selectively and efficiently cuts only ultraviolet rays of 300 to 400 nm. Furthermore, it is easy to manufacture and does not require control of pH or moisture content.
A method for producing a transparent film can be provided.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the absorbance curve of a glass coated sample of Example 1 of the present invention.

FIG. 2 is a diagram showing the absorbance curve of a comparative glass-coated sample.

Claims (1)

[Claims] Claim 1: Water is added to a mixed solution containing an organometallic compound of titanium, a cerium compound, and an organic compound containing at least one hydroxyl group and at least one ketone group, and the reaction solution is made transparent. A method for producing an ultraviolet cut filter, which is characterized by coating it on a substrate and sintering it.