JPH05173018A - Production of uv cut filter - Google Patents

Abstract

PURPOSE:To provide a UV cut filter which efficiently and selectively cut UV rays of 300-400nm wavelength. CONSTITUTION:A reaction liquid in a sol state is prepared by adding water to a mixture liquid of org. metal compd. of titanium. cerium compd., and elements of groups 3B, 4A and 4B except for carbon and titanium in the presence of an org. compd. having at least one hydroxyl group and at least one ether group, or an org. compd. having at least one hydroxyl group and at least one ketone group. This reaction liquid is applied on a transparent substrate and baked to form at least one layer of a thin film on the transparent substrate.

Description

Detailed Description of the Invention

[0001]

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

[0002]

2. Description of the Related Art As a conventional method of manufacturing an ultraviolet cut filter, a method of alternately laminating materials having different refractive indexes on a transparent substrate such as glass, a method of forming a thin film by vapor deposition of metal or metal oxide, It is known to dissolve or disperse an ultraviolet absorber in some kind of binder and apply it, or to make glass contain zinc sulfide or the like.

In Japanese Patent Laid-Open No. 63-103083, an acid is added to a mixed solution of titanium alkoxide and a cerium compound to adjust the pH to 3.5.
Disclosed is a method of forming a coating film of cerium-containing titanium oxide by adjusting the water content in the total solution to 8% or less, adhering this mixed solution to the surface of the substrate, and then heating it to 200 ° C. or higher. Has been done.

[0004]

However, in such a conventional method, for example, a method using a vapor deposition method has a small throughput and a small reaction chamber, so that only a small area of the filter can be formed and the cost is increased. There was a problem. The method of dissolving or dispersing the ultraviolet absorber in some kind of binder and applying the same has a problem that absorption at a preferable wavelength cannot be obtained depending on the kind of the binder and the ultraviolet absorber. The method of incorporating zinc sulfide or the like into glass has a problem that it is difficult to prepare glass and a large-area glass cannot be obtained.

The method disclosed in Japanese Patent Laid-Open No. 63-103083 has absorption even in the visible light region of 400 nm and below,
There is a problem that it also cuts part of the visible range and cannot cut only ultraviolet rays. Further, there are problems that it is difficult to control pH and water content, and the pot life of the mixed solution is short.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned conventional problems and to provide an ultraviolet cut filter which selectively and efficiently cuts only ultraviolet rays of 300 to 400 nm. Still another object of the present invention is to provide an inexpensive and large area filter.

[0007]

The above objects of the present invention are as follows.
An organometallic compound of titanium and cerium in the presence of an organic compound having at least one hydroxyl group and at least one ether group, or an organic compound having at least one hydroxyl group and at least one ketone group At least one layer is prepared by adding water to a mixed solution of a compound and a compound of elements belonging to Groups 3B, 4A, and 4B of the periodic table except carbon and titanium, coating the reaction solution on a transparent substrate, and baking the solution. It was achieved by forming a thin film of the above on a transparent substrate.

The present invention will be described in detail below. The present invention is
An organometallic compound of titanium and cerium in the presence of an organic compound having at least one hydroxyl group and at least one ether group, or an organic compound having at least one hydroxyl group and at least one ketone group Water is added to a mixed solution of a compound and a compound of elements belonging to groups 3B, 4A, and 4B of the periodic table except carbon and titanium to form a sol, which is applied on a transparent substrate and baked to make at least one thin film transparent. It is characterized in that it is formed on a substrate.

The method of adding water to such a mixed solution to form metal ions into a sol is generally called a sol-gel method. The method for forming a thin film by the sol-gel method is described in, for example, "Manufacturing Technology of Glass-Ceramics by the Sol-Gel Method and Its Applications" (edited by Masayuki Yamane, Applied Technology Publication, 1989), pages 108-140. 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 is hydrolyzed to form a sol having a Ti-O-Ti bond. By appropriately selecting the viscosity, the film is applied to the substrate by any means to form a thin film. The coating method is selected from a dip method, a spin coating method, a spray method and the like. Then, it is baked.

The organometallic compound of titanium used in the present invention is preferably titanium alkoxide. Titanium alkoxide is represented by the general formula Ti (OR) _m . Here, m is an integer and represents the coordination number of the alcoholate group, and is generally 1 to 4. R is selected from any alkyl group. Examples of R include a methyl group, an ethyl group, a propyl group, an isopropyl group, and a butyl group.

As the cerium compound, an inorganic compound of cerium, such as cerium nitrate, cerium chloride and cerium sulfate, is preferably used.

Any element other than carbon and titanium belonging to Groups 3B, 4A and 4B of the periodic table can be used, but preferably selected from the elements of the 1st to 5th periods. They are B, Al, Si, Ga, Ge, Zr, In and Sn, and any one of them is selected. The compounds of these elements may be used alone or in combination of a plurality of elements. As an inorganic compound as an elemental compound, a halide salt such as a chloride salt, a bromide salt,
Sulfates, perchlorates, etc. are preferably used. Moreover, an alkoxide is used as the organometallic compound. The alkoxides of these metals are represented by the general formula M (OR) _n . Here, M represents the above metal ion, and n
Is an integer and represents the coordination number of the alcoholate group, and is generally 1-8. R is selected from any alkyl group. Examples of R include a methyl group, an ethyl group, a propyl group, an isopropyl group, and a butyl group.

The organometallic compound of titanium and the cerium compound are mixed in a molar ratio of Ti: Ce = 1: 5 to 100:
It is preferably in the range of 1. Organometallic compounds and cerium compounds of titanium and 3B, 4A, 4B of the periodic table
The mixing ratio of the element (M) belonging to the group other than carbon and titanium is preferably in the range of (Ti + Ce): M = 1: 0.1 to 1:10.

The organic compound having at least one hydroxyl group and at least one ether group used in the present invention is preferably an ether form of glycol, specifically, 2- (2-methoxyethoxy) ethanol. , 2- (2-ethoxyethoxy) ethanol, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, triethylene glycol monomethyl ether, triethylene glycol dimethyl ether, triethylene glycol diethyl ether, triethylene glycol dimethyl ether, 2- (2-methoxypropyl) ethanol, 2- (2-Ethoxyethoxy) propanol and the like are preferably used. The organic compound containing at least one hydroxyl group and at least one ketone group is generally called hydroxyketone, and acetone alcohol, acetoin, diacetone alcohol, benzoin and the like are preferable. The addition amount of this organic compound to all metal ions is preferably in the range of 0.1 to 10 in terms of molar ratio.

In the present invention, water is added to convert the metal ions into a sol, but the amount of water may be arbitrary. Preferably, the molar amount is 1 to 10 times the metal ion. Further, an acid may be added when the sol is formed. As the acid, nitric acid, hydrochloric acid, acetic acid, sulfuric acid and the like are preferable. The reaction temperature may be arbitrary, but is preferably 50 to 80 ° C. Any solvent may be used as long as it can dissolve these compounds, but alcohols such as ethyl alcohol, propyl alcohol and butyl alcohol are preferably used. Sintering should be at a temperature at which organic compounds are removed, preferably above 100 ° C. Further, the temperature should be such that the substrate is not deformed or deteriorated, and in the case of the present invention, 900 ° C or lower is preferable. The heating time may be 5 to 60 minutes.

The thin film used in the present invention needs to be laminated in at least one layer, and two or more layers may be applied in order to increase the absorbance. As for the laminating method, one layer may be applied and then applied, or further applied after sintering. The substrate to be applied may be any transparent substrate,
Preferably glass substrate such as soda lime, quartz substrate,
It is selected from plastic substrates such as polycarbonate.

[0017]

According to the present invention, an organic compound having at least one or more hydroxyl group and at least one or more ether group, or at least one or more hydroxyl group and at least 1
In the presence of an organic compound having one or more ketone groups, water is added to a mixed liquid of an organometallic compound of titanium, a cerium compound, and a compound of elements belonging to Groups 3B, 4A, and 4B of the periodic table except carbon and titanium. Then, the reaction solution is applied to a transparent substrate and sintered to form at least one layer of thin film on the transparent substrate.
It is possible to provide an ultraviolet cut filter that selectively and efficiently cuts only ultraviolet light of nm. Further, it is possible to provide an inexpensive and large-area filter.

[0018]

EXAMPLES The present invention will be further described below with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples. Comparative Example 1.9 g of cerium chloride was dissolved in 30 cc of ethanol.
1.4 g of titanium tetraisopropoxide was added to this solution at room temperature.
Was added and 1 cc of 30% acetic acid was further added to adjust the pH to 4.
This solution was applied onto soda lime glass with a spinner. The spinner application condition was 3000 rpm for 30 seconds. After drying the coated sample in the atmosphere, put it in an electric furnace,
Sintered at 500 ° C for 10 minutes. The obtained yellow glass was devitrified. The absorbance curve of this glass is shown in FIG. 440
It had an absorption maximum at nm and an absorption in the visible region. Since the sample was devitrified, the transmittance was low in the visible range and the ultraviolet range, and a reliable transmittance curve could not be obtained. Furthermore, when this solution was left at room temperature for 1 week, it became cloudy,
It was impossible to apply.

Example 1 2.8 g of cerium chloride was added and dissolved in 35 cc of ethanol. To this solution, 1.7 g of titanium tetraisopropoxide was added, 0.9 g of silicon tetraethoxide was added, and 5.0 g of 2- (2-methoxyethoxy) ethanol was added, and the mixture was stirred and heated at 80 ° C. for 1 hour. After cooling to room temperature, 0.35 mL of water and 0.1 mL of 61% nitric acid were added, and the mixture was stirred and heated at 80 ° C for 1 hour. The pH at this time was 2. After this solution was cooled to room temperature, it was applied onto soda lime glass by a spinner. Spinner application condition is 1000 rpm
It was 30 seconds. After the coated sample was dried in the air, it was placed in an electric furnace and sintered at 500 ° C. for 10 minutes. The thickness of the obtained thin film sample was 0.4 μm. The absorbance curve of the thin film sample is shown in FIG. As shown in the figure, it has good absorption in the UV region of 300 to 400 nm and cuts UV rays well. The reaction solution was left at room temperature for 1 week. The reaction solution was transparent and could be applied. The glass coated sample showed the same absorbance as above.

Example 2 Cerium nitrate was used in place of cerium chloride in Example 1.
Using 2.8 g, and using 2.3 g of titanium tetra-n-butoxide instead of titanium tetraisopropoxide, 2- (2-
A thin film sample was prepared in the same manner as in Example 1 except that 2.0 g of triethylene glycol monomethyl ether was used instead of (methoxyethoxy) ethanol. The absorption curve of the obtained thin film sample was similar to that of Example 1, and had a good absorption in the ultraviolet region of 300 to 400 nm and had a good cut of ultraviolet rays.

Example 3 The amount of water in Example 1 was changed from 0.12 mL to 0.2, 0.5,
It was changed to 0.6 mL. It was applied and sintered in the same manner as in Example 1. The absorption curve of the obtained thin film sample was similar to that of Example 1, and had a good absorption in the ultraviolet region of 300 to 400 nm and had a good cut of ultraviolet rays. The reaction solution was left at room temperature for 1 week. The solution was transparent and could be applied. The coated thin film sample showed the same absorbance as above.

Example 4 Instead of silicon tetraethoxide in Example 1,
A thin film sample was prepared in the same manner as in Example 1 except that aluminum tetrabutoxide was used in an equimolar amount. The absorption curve of the obtained thin film sample was similar to that of Example 1, and had a good absorption in the ultraviolet region of 300 to 400 nm and had a good cut of ultraviolet rays.

EXAMPLE 5 Zirconium tetrabutoxide was used in place of silicon tetraethoxide in Example 1 in an equimolar amount, titanium tetraethoxide was used in place of titanium tetraethoxide in an equimolar amount, and 2- (2- It was coated in the same manner as in Example 1 except that triethylene glycol monomethyl ether was used in an equimolar amount in place of (methoxyethoxy) ethanol, and 50 mL of n-butanol was used in place of the solvent. The absorption curve of the obtained thin film sample was similar to that of Example 1, and had a good absorption in the ultraviolet region of 300 to 400 nm and had a good cut of ultraviolet rays.

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 absorption curve of the obtained thin film sample was similar to that of Example 1, and had a good absorption in the ultraviolet region of 300 to 400 nm and had a good cut of ultraviolet rays.

Example 7 Instead of the spinner coating in Example 2, a dip coating method was used and the size of the glass substrate was 500 mm × 500 mm × 3.
A glass-coated sample was prepared in the same manner as in Example 2 except that mmt was used. The coating was uniform, and the absorbance of the obtained thin film sample was the same as in Example 2.

Example 8 The thin film sample prepared in Example 1 was further added to Example 1
The solution prepared in 1. was applied and sintered in the same manner (sample applied twice). Further, coating and sintering were repeated in the same manner as above (3
Reapplied sample). The absorbance curve of the obtained thin film sample is shown in FIG. As a comparison, the absorbance curve of Example 1 is also shown.
The double-coated sample gives higher absorbance than the single-coated sample,
The three-time application sample gave higher absorbance than the two-time application sample, and the UV blocking effect was further improved.

[0027]

As described in detail above, according to the present invention,
An organometallic compound of titanium and cerium in the presence of an organic compound having at least one hydroxyl group and at least one ether group, or an organic compound having at least one hydroxyl group and at least one ketone group A thin film of at least one layer obtained by adding water to a mixed liquid of a compound and a compound of elements belonging to Groups 3B, 4A, and 4B of the periodic table except carbon and titanium, and coating and baking the mixture, 30 by forming on a transparent substrate
It is possible to provide an ultraviolet ray cut filter that selectively and efficiently cuts only ultraviolet rays of 0 to 400 nm. Further, it is possible to provide an inexpensive and large-area filter.

[Brief description of drawings]

FIG. 1 is a diagram showing an absorbance curve of a thin film sample of Example 1 of the present invention.

FIG. 2 is a diagram showing an absorbance curve of a thin film sample of Example 8 of the present invention.

FIG. 3 is a diagram showing an absorbance curve of a thin film sample of a comparative example.

Claims (1)

[Claims] 1. A titanium compound in the presence of an organic compound having at least one or more hydroxyl group and at least one or more ether group, or an organic compound having at least one or more hydroxyl group and at least one or more ketone group. Organometallic compounds and cerium compounds and 3B, 4A of the periodic table,
Water is added to a mixed solution of compounds of elements belonging to Group 4B except carbon and titanium to form a sol, and this reaction solution is applied onto a transparent substrate and baked to form at least one thin film on the transparent substrate. A method for producing an ultraviolet cut filter, characterized by: