JPH04130301A - Ultraviolet ray cut filter - Google Patents

Abstract

PURPOSE:To execute excellent UV cut by adding water to a liquid mixture composed of an org. compd. of Ti and a Ce compd. in the presence of an org. comp. contg. hydroxyl groups and ether groups to form a sol, applying the sol on a transparent substrate and sintering the coating, thereby imparting specific optical transparency thereto. CONSTITUTION:The UV cut thin film is obtd. by adding the water to the liquid mixture composed of the org. metal compd. of the titanium and the cerium compd. in the presence of the org. compd. having at least >=1 pieces of the hydroxyl groups and at least >=1 pieces of the ether groups to form the sol, applying the sol on the transparent substrate and sintering the coating. Then the water is added to the liquid mixture composed of the org. metal compd. of the titanium and the cerium compd. in the presence of the org. compd. having at least >=1 pieces of the hydroxyl groups and at least >=1 pieces of the ether groups to form the sol and this sol is applied on the transparent substrate, then the coating is sintered, by which the following UV cut thin film is obtd.: The point where the min. value of the transmissivity in terms of the transmitter per 0.1mum film thickness attains <=30% at <=(320 to 400nm) exists in this film and the point where the max. value attains >=90% exists at 401 to 500nm exists therein.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to an ultraviolet cut filter, and more particularly to an ultraviolet cut filter having an ultraviolet cut thin film on a transparent substrate such as glass.

(Prior art) Conventional ultraviolet cut filters include a method in which multiple layers of materials 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. There are known methods such as (1) dissolving or dispersing an ultraviolet absorber in some kind of binder and applying it, and (2) containing zinc sulfide or the like in glass.

Furthermore, in JP-A-63-103083, acid is added to a mixed solution of titanium alkoxide and a cerium compound to adjust the pn to 3.5 to 5, and the water content in the total solution is adjusted to 8% or less. After applying the liquid to the substrate surface, heat at 200°C.
A method is disclosed in which a cerium-containing titanium oxide film is formed by heating to the above temperature.

(Problem to be Solved by the Invention) However, in the case of ultraviolet cut filters obtained by such conventional methods, for example, those by vapor deposition have small throughputs and small reaction chambers, so they require a small area as a filter. The problem was that only one product could be produced, and the cost was high. Furthermore, methods in which the ultraviolet absorber is dissolved or dispersed in some kind of binder and then applied have the problem that absorption at a preferred wavelength may not be achieved depending on the type of binder or ultraviolet absorber. Furthermore, according to the method of incorporating zinc sulfide or the like into the glass, there are problems such as difficulty in preparing the glass, making it impossible to obtain a glass with a large area.

Further, according to the method disclosed in JP-A No. 63-103083, the obtained thin film is a film colored in shades of yellow to golden yellow, and has absorption in the visible light range of 400 nm and beyond. The problem is that it also cuts part of the visible range, making it impossible to cut only ultraviolet rays. moreover,
There are problems in that it is difficult to control the pH and the water content, and the pot life of the mixed liquid is short.

Therefore, an object of the present invention is to provide an ultraviolet cut filter that selectively and efficiently cuts only ultraviolet rays of 300 to 400 nm.

Furthermore, another object of the present invention is to provide a transparent ultraviolet cut filter that is inexpensive, has a large area, is easy to manufacture, and does not require control of pH or water content.

(Means for Solving the Problems) The ultraviolet filter of the present invention, which has achieved the above object, uses titanium in the presence of an organic compound having at least one hydroxyl group and at least one ether group. Water is added to a mixed solution of an organometallic compound and a cerium compound to form a sol, and the resulting film is coated on a transparent substrate and sintered.
There is a point where the minimum value is 30% or less at 0 to 400 nm or less, and the maximum value is 90% at 401 to 500 nm.
It is characterized by having an ultraviolet cut thin film that has the above points.

The present invention will be explained in detail below.

The above-mentioned ultraviolet cut thin film used in the present invention is produced by adding water to a mixed solution of an organometallic titanium compound and a cerium compound in the presence of an organic compound having at least one hydroxyl group and at least one ether group. It is obtained by converting it into a sol, coating it on a transparent substrate, and sintering it.

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

The method for forming thin films by the sol-gel method is described in, for example, "Manufacturing technology for glass and ceramics by the sol-gel method and its application" (edited by Masayuki Yamane, Applied Technology Publishing, 1989).
It is described on 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 Ti-0-Ti bonds. By appropriately selecting the viscosity, it can be applied by any means to form a thin film. Application methods include dimb method,
The method is selected from spin coating, spraying, etc. Then, it is sintered.

The titanium organometallic compound used in the present invention includes:
Titanium alkoxide is preferred.

Titanium alkoxide has the general formula Ti (OR). Here, n is an integer representing the coordination number of the alcoholade group, and is 1 to 4 for boat fishing. 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.

As a mixed side combination of a titanium organometallic compound and a cerium compound, the molar ratio is Ti:Ce=1:5 to 10.
A range of 0:1 is preferred.

In the present invention, in the presence of an organic compound having at least one hydroxyl group and at least one ether group, water is added to a mixture of a titanium organometallic compound and a cerium compound to form a sol, and the mixture is placed on a transparent substrate. By coating and sintering, the transmittance is reduced to 3 per film thickness of 0.1 μm.
There is a point where the minimum value is 30% or less at 20 to 400 nm or less, and the maximum value is 90 at 401 to 500 nm.
It was previously unimaginable to be able to obtain an ultraviolet ray-cutting thin film that has a point where the amount of UV rays exceeds %.

As the organic compound having at least one hydroxyl group and at least one ether group, an ether form of glycol is preferable, and 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)propertool, etc. are preferably used. The amount of this organic compound added to the total 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 solize the 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. The reaction temperature may be arbitrary, but preferably 50 to 80°C.

Any solvent may be used as long as these compounds can be dissolved therein, but alcohols such as ethyl alcohol, propyl alcohol, and phthyl alcohol are preferably used. Sintering should be performed at a temperature that removes organic compounds, preferably 100°C or higher. In addition, the temperature should be such that the substrate does not deform or deteriorate; in the case of the present invention, the temperature is 70°C.
The temperature is preferably 0°C or lower. Heating time may be 5 to 60 minutes.

The lamination method may be such that one layer is applied and then another layer is applied, or another layer is applied 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.

(Function) According to the present invention, the ultraviolet cut thin film deposited on the transparent substrate has a transmittance of 320 per film thickness of 0.1 μm.
There is a point where the minimum value is 30% or less at ~400 nm or less, and there is a point where the maximum value is 90% or more at 401-500 nm. Therefore, the UV power of the present invention is equipped with such a UV-canting thin film.

The filter can selectively and efficiently cant only ultraviolet rays of 300 to 400 r+m. Furthermore, according to the present invention, an inexpensive, large-area filter can be obtained, easy to manufacture, and p
There is no need to control H or water content, and a transparent filter can be obtained.

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

Soil Comparison 1.9 g of cerium chloride was dissolved in 30 cc of ethanol. Add 1 part of titanium tetraisopropoxide to this solution at room temperature.
．． 4 g, and then 1 cc of 30% acetic acid.
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 curve of this glass is shown in FIG.

It had an absorption maximum at 440 nwl and absorption in the visible range. Because the sample was devitrified, the transmittance was low in the visible and ultraviolet regions, and a reliable transmittance curve could not be obtained.

Furthermore, when this solution was left at room temperature for one week, it became cloudy and coating was impossible.

Implementation 1.9 g of cerium chloride was added to 30 cc of ethanol and dissolved. 1.4 g of titanium tetraisopropoxide was added to this solution, and further 1.5 g of 2-(2-methoxyethoxy)ethanol was added, and the mixture was stirred at 80°C for 1 hour.
Heated. After cooling to room temperature, 0.25 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 cooling this solution to room temperature, it was applied onto soda lime glass using a spinner. The spinner application conditions are 300 rpm and 3.
It was 0 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 thickness of the obtained thin film sample was 0.1 μm. The transmittance curve of the thin film sample is shown in FIG.

The transmittance is 30% or less below 350nm, and the transmittance is below 350nm.
A maximum transmittance of 96% was given to m.

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

Fushigo I 2.2g of cerium nitrate was used instead of cerium chloride in Example 1, 2.0g of titanium tetra-n-butoxide was used instead of titanium tetraisopropoxide, and 2-(2-methoxyethoxy)ethanol was used. A thin film sample was prepared in the same manner as in Example 1, except that 1.8 g of triethylene glycol monomethyl ether was used instead.

The transmittance of the obtained thin film sample was similar to Example 1.

Transmittance is 30% or less at 340nm or less, and at 460nm
A maximum transmittance of 93% was given to m.

Actual] IΔ1 The amount of water in Example 1 was changed from 0.12n+1 to 0.2.
The volume was changed to 0.5Q and 6ml. It was coated and sintered in the same manner as in Example 1. As in Example 1, the transmittance of the thin film sample is
The transmittance was 30% or less at 350 nm or less, and the maximum transmittance was 96% at 450 nm.

Further, this reaction solution was left at room temperature for one week. The solution was clear and coatable. The coated thin film sample showed similar transmittance as above.

In place of nitric acid in Backyard Masudo Example 1, 35% hydrochloric acid was used, and the amount was 0.1.0.3.0.6.0.8.1.0 ml
and changed it. The pH of the solution at this time is 3.0 to 0.1
Met. A coated sample was prepared in the same manner as in Example 1.

The transmittance of the obtained sample was 30% or less at 350 nm or less, as in Example 1, and the maximum transmittance was 9 at 450 nm.
gave 6%.

XUJIIU - Cerium acetate 1 instead of cerium chloride in Example 1
．． 7g, using 0.5g of titanium tetraethoxide in place of titanium tetraisopropoxide, 2-
Coating was carried out in the same manner as in Example 1, except that 4.5 g of diethylene glycol diethyl ether was used instead of (2-methoxyethoxy)ethanol, and 100 ml of n-butanol was used instead of ethanol as the solvent. The transmittance of the obtained thin film sample was similar to Example 1. Transmittance is 370n
The maximum transmittance was 92% at 480 nm.

A coated sample was prepared in the same manner as in Example 1, except that quartz glass was used in place of the soda lime glass in Example 1. The transmittance of the obtained sample was 30% or less at 350 nm or less, and the maximum transmittance was 96% at 450 nm.

Tip coating 1 Instead of the spinner coating in Example 2, a dip coating method was used, and the size of the glass substrate was 500mm x 500mm.
A glass coating sample was prepared in the same manner as in Example 2, except that the dimensions were mm x 3 mm t. The coating was uniform and the transmittance of the resulting thin film sample was similar to that of Example 2. In other words, the transmittance is 30% or less at 340 nm or less, and 46
A maximum transmittance of 93% was given at 0 nm.

It blocks ultraviolet rays of 300 to 400 nm.

In addition to the thin film sample prepared in Example 1, Example 1
The solution prepared above was applied and sintered in the same manner (two-time coating sample). Furthermore, coating and sintering were repeated in the same manner as above (3
2-time coating sample). The transmittance curve of the obtained thin film sample is shown in FIG. For comparison, the transmittance curve of Example 1 is also shown.

The twice-coated sample was less than 30% at 365 nm or less, and 3
The twice-coated sample had a wavelength of 380 nm or less and 30% or less. Further, both the two-time coating sample and the three-time coating sample gave a maximum transmittance of 96% at 450 nm, showing the same value as Example 1.

It can be seen that the thicker the film, the more effective it is at blocking UV rays.

(Effects of the Invention) As detailed above, the ultraviolet cut filter of the present invention uses an organic compound having at least one hydroxyl group and at least one ether group as an ultraviolet filter film provided on a transparent substrate. By adding water to a mixed solution of a titanium organometallic compound and a cerium compound to form a sol in the presence of There is a point where the minimum value is 30% or less when the transmittance is 320 to 400nrr1 or less when converted to .1 μm, and there is a point in the range of 401 to 500nm.
Since there is a point where the maximum value is 90% or more, it is possible to selectively and efficiently cant only ultraviolet rays of 300 to 400 nm. Furthermore, it is easy to manufacture, there is no need to control pH or water content, and it is possible to provide an ultraviolet cut filter that is a transparent film.

[Brief explanation of the drawing]

Fig. 1 is a diagram showing the absorbance curve of a thin film sample of a comparative example, Fig. 2 is a diagram showing a transmittance curve of a thin film sample of Example 1 of the present invention, and Fig. 3 is a diagram showing a transmittance curve of a thin film sample of Example 8 of the present invention. FIG. 2 is a diagram showing a transmittance curve of a thin film sample. Figure 1: wave l (η) Figure 2: long (n)

Claims (1)

[Claims] 1. In the presence of an organic compound having at least one hydroxyl group and at least one ether group, water is added to a mixed solution of a titanium organometallic compound and a cerium compound to form a sol, and the sol is applied onto a transparent substrate. The transmittance obtained by sintering is 320 to 400 per film thickness of 0.1 μm.
1. An ultraviolet cut filter comprising an ultraviolet cut thin film having a point where the minimum value is 30% or less in the range of nm or less and a point where the maximum value is 90% or more in the range from 401 to 500 nm.