JPH02225342A - Ultrafine particle-dispersed glass and production thereof - Google Patents

Abstract

PURPOSE:To obtain the title glass excellent in heat resistance, chemical durability, etc., dispersed with ultrafine particles of metal (metallic oxide) by heating a metallic compound-contg. silica gel to decompose the metallic compound into metal (metallic oxide) followed by baking. CONSTITUTION:An aqueous solution containing both a metallic compound (e.g. manganese nitrate) and an alkyl silicate (e.g. tetramethyl orthosilicate) and/or its hydrolyzate is hydrolyzed and put to dehydration condensation treatment to produce a metallic compound-contg. silica gel. This gel is then heated to decompose said metallic compound into metal and/or metallic oxide. Thence the resultant gel is sintered, thus obtaining the objective silica glass dispersed with ultrafine particles of metal (e.g. Mn) and/or metallic oxide (e.g. MnO) <=1mum in size, useful for infrared-transmissive filters, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to an ultrafine particle dispersed glass and a method for manufacturing the same. The ultrafine particle dispersion glass of the present invention can be used for infrared transmission filters and color filters used in optical equipment,
Furthermore, it is used for nonlinear optical materials and the like.

[Prior Art] Conventionally, ultrafine particle dispersed glass has been produced through the following three steps, including a melting step at a high temperature. That is, first, the metal or metal compound that will become the raw material for the ultrafine particles is added to multiple types of raw materials suitable for the glass composition that will become the matrix, melted with uniform stirring at a temperature of 1,300 degrees Celsius or higher, and solidified by cooling by - degrees. Obtain glass (melting process). Next, after processing this glass into an appropriate size, it is heated again to about 1100°C to ionize the elements that make up the ultrafine particles again, and then rapidly cooled to create a glass that does not contain ultrafine particles (colorless). process). Furthermore, this glass is heated to 500 to 800℃.
Ultrafine particles are precipitated within the glass body by heating for a certain period of time (coloring heat treatment process).

[Problems to be Solved by the Invention] Ultrafine particle dispersed glass is manufactured through the above three steps, but in this method, it is necessary to use a multicomponent glass as the matrix glass. The reason is,
This is because multi-component glass is easy to melt and also provides stability against crystallization. In other words, if the matrix is made of quartz single component glass, the melting temperature will exceed 1600°C, which will easily deteriorate the heating element and refractories that make up the electric furnace, and its characteristics will make mass production difficult.
The stability of the glass against crystallization is poor, making it easy to devitrify.
Furthermore, the amount of evaporation of the substance constituting the dispersed ultrafine particles increases, making it difficult to obtain desired glass properties and reducing productivity. For this reason, other components, such as modifying components such as alkali metal oxides, alkaline earth metal oxides, lead oxide, zinc oxide, etc., are added to lower the melting temperature and - improve the stability against crystallization.

However, compared to using quartz glass as a glass matrix, when using multi-component glass as a matrix, multi-component glass usually has a low glass transition temperature of about 560°C or less, so it has a disadvantage that it has low heat resistance and cannot be used at high temperatures. there were. It also had drawbacks such as reduced chemical durability and environmental resistance. Furthermore, since glass matrix components such as zinc and alkali metals may be mixed as impurities into the dispersed ultrafine particles, it is expected that they will not have a negative effect on optical nonlinearity.

Therefore, the first object of the present invention is to solve the drawbacks of conventional ultrafine particle dispersion glass, and to provide an ultrafine particle dispersion glass that has excellent heat resistance, chemical durability, environmental resistance, etc., and has less impurities in the ultrafine particles. Our goal is to provide glass.

A second object of the present invention is to make it possible to produce the above-mentioned ultrafine particle dispersed glass with high productivity, which has excellent heat resistance, chemical durability, environmental resistance, etc., and has few impurities in the ultrafine particles. The purpose is to provide a method.

[Means for Solving the Problems] A first object of the present invention is to provide an ultrafine particle-dispersed glass characterized in that ultrafine particles of metal and/or metal oxide having a particle size of 1 μm or less are dispersed in quartz glass. achieved by.

A second object of the present invention is to provide a first step of preparing an aqueous solution containing an alkyl silicate and/or a hydrolyzate thereof and a metal compound; a second step of forming silica gel; heating the gel to decompose the metal compound into metal and/or metal oxide; then sintering the gel to disperse ultrafine particles of metal and/or metal oxide; This was achieved by a method for producing ultrafine particle dispersed glass, which is characterized by comprising: a third step of obtaining quartz glass;

According to a preferred embodiment of the present invention, when a silane coupling agent and/or dimethylformamide is contained in the aqueous solution prepared in the first step of the method for producing ultrafine particle-dispersed glass, compared to a case where these are not contained, The dispersibility of ultrafine particles in the glass matrix is significantly improved.

The present invention will be explained in detail below.

Since the ultrafine particle dispersed glass of the present invention has quartz glass as a matrix, it has excellent heat resistance, chemical durability, environmental resistance, etc.

Furthermore, since the matrix consists of a single component of quartz, the ultrafine particles of metal and/or metal oxide dispersed in the quartz glass matrix contain fewer impurities than those made of multi-component glass. The particle size of the ultrafine particles of metal and/or metal oxide is limited to 1 μm or less. 1μm
The reason why the thickness is limited to the following is that when it exceeds 1 μm, light scattering occurs and the transmittance decreases.

The ultrafine particle-dispersed glass of the present invention is used for infrared transmission filters, color filters, and nonlinear optical materials, etc., and has excellent heat resistance, chemical durability, environmental resistance, etc. as described above. /Or it has the advantage of being usable even in humid conditions. Furthermore, since ultrafine particles of metal and/or safe oxide with little impurity are dispersed in the silica glass matrix, it becomes an excellent optical material.

As mentioned above, ultrafine particle-dispersed glass with a quartz glass matrix is difficult to manufacture using conventional melting methods.
It has become possible to manufacture it by the method of the present invention including the first, second, and third steps described above. Below, these three steps will be explained in order.

First, in the first step, an alkyl silicate and/or its hydrolyzate, which is a raw material for silica glass, and a metal compound, which is a raw material for ultrafine particles, are added to water to form a uniform aqueous solution.

As the alkyl silicate, those represented by the formula % (in the formula, R is an alkyl group having 1 to 4 carbon atoms such as methyl, ethyl, propyl, butyl group) are used.

Also, instead of or together with alkyl silicate, partial hydrolyzate of alkyl silicate, i.e. Si (OR)3 (OH) Si (OR) 2 (OH)t S t (OR) (OH)3 or complete hydrolyzate 5i(OH)a may also be used. It is preferable to use highly purified alkyl silicates and/or hydrolysates thereof.

Examples of metal compounds include nitrates, sulfates, acetates, and chlorides of metals such as manganese, copper, gold, and platinum, and HAu.
Chlorometallates such as Cl4 (general formula HxMyC1z:
M is a metal (r, Any metal and/or metal oxide can be used. In addition to the metal compounds exemplified above, acid solutions of metals are also included in the metal compounds used in the present invention. It is also preferable to use highly purified metal compounds.

Note that the solubility of the alkyl silicate or metal compound can be increased by using an alcohol solvent such as methanol or ethanol together with water.

The alkyl silicate and/or its hydrolyzate added to water or a water-alcoholic solvent, etc., and the metal compound are uniformly mixed so that the metal compound is not unevenly distributed in (.

In this first step, alkyl silica-1 and/or
Alternatively, a silane coupling agent and/or dimethylformamide can be used together with the hydrolyzate and the metal compound, and by using at least one of these substances, the ultrafine particle glass finally obtained can be dispersed in the glass matrix. The concentration distribution of the ultrafine particles can be made more uniform than when these substances are not used.

The silane coupling agent is soluble in water or a water-alcohol solvent, and has the effect of temporarily binding the metal compound or the metal and/or metal oxide generated from the matrix to the matrix, and Any glass can be used as long as it can complete the decomposition at a temperature below the sintering (making it non-porous) temperature of the gel in the third step and produce a glass with no remaining carbon or nitrogen, but amine-based Examples include silane coupling agents, alkylsilane coupling agents, titanium-based silane coupling agents, and the like.

Dimethylformamide, like the silane coupling agent, contributes to improving the uniformity of the concentration distribution of ultrafine particles dispersed in the glass matrix, but it also contributes to the occurrence of cracks due to drying during gel production in the second step described below. It also has the effect of preventing cracking and cracking.

The preferred amount of the silane coupling agent and/or dimethylformamide added is 0.5 per 11 moles of the metal compound.
~4 moles. If the amount is less than 0.5 mol, the effect of improving the uniformity of the concentration distribution of the ultrafine particles will be small, and if it exceeds 4 mol, the gelation time will be too short, which is not preferable.

Next, in the second step, the homogeneous solution obtained in the first step is gelated by hydrolysis and dehydration condensation treatment,
A metal compound-containing silica gel is obtained.

Note that when only a complete hydrolyzate of alkyl silicate is used as the raw material for the quartz glass matrix, the above-mentioned hydrolysis is not performed, and only dehydration condensation is performed. At this time, the metal compound exists in the fine pores of the gel obtained by hydrolysis and dehydration condensation of the alkyl silicate and/or its hydrolyzate. When a silane coupling agent and/or dimethylformamide is used in the first step, the alkyl silicate and/or its hydrolyzate and the metal compound can form hydrogen bonds etc. due to the presence of the silane coupling agent and/or dimethylformamide. Weaker binding results in more uniform dispersion and further immobilization.

Next, in the third step, the gel obtained in the second step is heated to decompose the metal compound into metal and/or metal oxide,
Next, the gel is sintered to obtain quartz glass in which ultrafine particles of metal and/or metal oxide are uniformly dispersed. In this third step, it is first necessary to heat the gel to completely decompose the metal compound into the desired metal and/or metal oxide. The reason is that if the decomposition of the metal compound into metal and/or metal oxide is insufficient, gas will be generated in the subsequent sintering step, causing closed pores and foaming. From this point of view, the temperature at the stage of decomposing metal compounds into metals and/or metal oxides is between 200 and 200℃.
Preferably, the temperature is 600°C and the time is 3 to 30 hours.

Further, in the sintering step, if the heating temperature or time for making the gel non-porous is insufficient, pores remain in the glass, which is undesirable because it causes light scattering. On the other hand, if the temperature is raised too much, quartz reacts with the metal and/or metal oxide, and crystals may precipitate, or the metal and/or metal oxide may become gigantic or devitrified. That is, it is necessary to select conditions under which the gel becomes non-porous and the ultrafine particles of metal and/or metal oxide are uniformly dispersed in the quartz glass matrix. From this point of view, it is preferable that the temperature of the sintering step is 800 to 1200°C and the time is 1 to 10 hours.

Furthermore, by adjusting the pH of the starting solution, it is also possible to change the pore size of the resulting gel and change the pore-free temperature.

In order to obtain quartz glass by the conventional melting method, 160
However, according to the method of the present invention, a melting temperature of 0°C or higher is required, which makes it difficult to mass-produce. It is possible to obtain quartz glass at a temperature of Glass can be obtained with high productivity.

Furthermore, the uniformity of the concentration distribution of the ultrafine particle-dispersed glass obtained by the method of the present invention is improved by using a silane coupling agent and/or dimethylformamide.

[Example] Hereinafter, the present invention will be explained in detail with reference to Examples.

Example 1 Commercially available tetramethyl orthosilicate (7
MO8), tetraethylorthosilicate) (TE01
), ethanol, manganese nitrate (all of the above are special grade reagents), and distilled water.

As the first step, first, 815.2 g of 7MO and 2 g of TE01 were placed in a 200 ml polypropylene container in a water bath at 15°C.
0.8 g and 46.0 g of ethanol were added. While stirring, 1.6 g of manganese nitrate was added dropwise together with 14.4 g of distilled water, and stirring was continued for an additional 10 minutes to obtain a homogeneous mixed solution.

Next, as the second step, spread this mixture into 8 cm long and 5 cm wide
, 30 m in a 2 cm high polypropylene container with a lid.
One portion at a time was taken out, sealed, and kept at 70° C. to cause a hydrolysis reaction and, at the same time, to cause dehydration condensation to form a gel. 1
After a day, the gel was dried by making four holes with a diameter of 1 mm in the lid of the container and maintaining the temperature at 70°C to obtain a dry gel. Manganese nitrate is uniformly dispersed in this dry gel.

Next, as a third step, the dried gel taken out from the container was placed in a heating furnace in an oxygen atmosphere, and the temperature was raised from room temperature to 150° C. over 2 hours while flowing oxygen at 100 cc/ml. Hold at 150°C for 5 hours to remove residual alcohol, followed by 450°C at a heating rate of 25°C/hr.
The temperature was raised to 100% and maintained at this temperature for 10 hours to cause combustion removal of residual organic matter and decomposition of manganese nitrate to manganese oxide. Next, the temperature was heated again at a temperature increase rate of 25°C/hr, and when the temperature reached 700°C, the atmosphere in the furnace was replaced with helium gas.
Heat with zero flow, and continue to raise the temperature to 950°C for 4 hours.
Holds time. The above temperature program sintered the gel and made it non-porous, thereby producing a quartz glass body, and ultrafine manganese oxide particles were precipitated in the quartz glass body.

After polishing the obtained ultrafine particle dispersed glass body, SEM (
As a result of observation using a scanning electron microscope (Y mirror), it was found that particles with a size of 0.5 μm or less were dispersed.

X-ray diffraction diagram of a sample obtained by crushing this glass body into powder (
(using alpha rays for Cu) is shown in Figure 1.

As a result, the d value was 3.84 people and 2.72 people.

2.35 people, 1.66 people, and 1.42 people were obtained, and by checking these with a JPCDS card, it was found that Mn2O3 crystals were precipitated.

The resulting glass body was polished to a thickness of 150 μm, and the transmittance of the sample to light having a wavelength in the range of 250 nm to 2000 nm was measured. The measurement results are shown in FIG. 2, and it was confirmed that the film exhibited a transmittance of more than about 50% at 800 nm and could be used as an infrared transmission filter or a color filter.

In addition, as a result of measuring the thermal properties and chemical durability of the obtained glass using a powder method, the glass transition point (Tg) was 850°C.
The water resistance (Dw) is 0.01% and the acid resistance (Da) is 0.
．． 03% (Tg, Dw, and Da were measured according to the Japan Optical Glass Industry Association standard JOGIS-1975), and it was revealed that the film had excellent heat resistance, chemical durability, and environmental resistance.

Example 2 A glass body containing ultrafine manganese oxide particles was obtained in the same manner as in Example 1, except that an amine-based silane coupling agent that was not used in Example 1 was used.

That is, starting materials include commercially available tetramethylorthosilicate-1-(7MO8), tetraethylorthosilicate (TE01), ethanol, manganese nitrate, and N-2.
-Aminoethylaminopropyltrimethoxysilane (amine-based silane coupling agent) (all of the above are special grade reagents) and distilled water were used.

In the first step, 815.2 g of 7MO was placed in a 200 ml polypropylene container in a water bath at 5°C.

20.8 g of TE01, 46.0 g of ethanol, and 0.81 g of an amine-based silane coupling agent were added. Add 1.6g of manganese nitrate to this while stirring and add 14.4g of distilled water.
The mixture was added dropwise, and stirring was continued for an additional 10 minutes to obtain a homogeneous mixture.

Next, in the second step, this mixed solution was divided into 20ml portions into polypropylene containers with a diameter of 6.5cm and a height of 9CIII, covered with a lid with a pinhole of 1ml in diameter, and kept at 70°C for hydrolysis. At the same time, dehydration condensation occurred to form a gel. The gel was further dried by maintaining the temperature at 70°C to obtain a dry gel. Manganese nitrate is uniformly distributed in this dry gel.

Next, as a third step, the dry gel taken out from the container is placed in a heating furnace in an oxygen atmosphere, and the temperature is increased from room temperature to 150°C/h for 50 minutes while flowing oxygen at 100ee/win.
The temperature was raised to 00°C and maintained at this temperature for 1 hour to burn off residual organic matter and decompose manganese nitrate into manganese oxide. Next, heating was continued at a temperature increase rate of 150°C/h and maintained at 1125°C for 3 hours. Due to the above temperature program, the gel is sintered and becomes non-porous, resulting in a diameter of approximately 3C.
I111 A quartz glass body with a thickness of 3 mm was produced, and ultrafine manganese oxide particles were uniformly precipitated in the quartz glass body.

After mirror polishing the obtained ultrafine particle dispersed glass body, SEM (
As a result of observation using a scanning electron microscope (SEM), it was found that particles with a size of 0.5 μm or less were dispersed.

When the transmittance of this glass body polished to a thickness of 150 μm was measured for wavelengths in the range of 250 nm to 2000 nm, the same transmittance as shown in Fig. 2 was obtained.
It was confirmed that it exceeds about 50% at 00 nm, and can be used as an infrared transmission filter or a color filter.

The concentration distribution of manganese oxide in the thickness direction and the lateral direction of this disc-shaped glass body was measured using
It was measured using an OBE mlcro-analyser). The results are shown in FIG. From the figure, it was found that the concentration distribution of manganese oxide was extremely uniform in the thickness direction and the lateral direction.

In addition, as a result of measuring the thermal properties and chemical durability of the obtained glass using a powder method, the glass transition point (Tg) was 850°C.
So, water resistance (D w ) is 0.01%, acid resistance (Da)
was 0.03% (Tg, Dw, and Da were measured according to Japan Optical Glass Industry Standard JOGIS-1975), and it was revealed that it has excellent heat resistance, chemical durability, and environmental resistance.

Example 3 A glass body containing ultrafine manganese oxide particles was obtained in the same manner as in Example 2, except that an alkylsilane coupling agent (methyltrimethoxysilane) was used instead of the amine-based silane coupling agent.

The ultrafine particle-dispersed glass body thus obtained has ultrafine manganese oxide particles uniformly dispersed in it, similar to the ultrafine particle-dispersed glass body obtained in Example 2, and the measured transmittance is higher than that of the ultrafine particle dispersion glass body obtained in Example 2. The transmittance was the same as that of the dispersed glass body, and the properties were similar to those of the ultrafine particle dispersed glass body of Example 2.

Example 4 Commercially available tetramethyl orthosilicate (7
MO3), tetraethylorthosilicate) (TE0
1) Ethanol, gold chloride (all of the above are special grade reagents), and distilled water were used.

As the first step, first, 33.04 g of 7MO was added to a 2QOIll container made of polypropylene in a water bath at 5°C.
4.16 g and 9.20 g of ethanol were added. A solution of 0.012 g of gold chloride dissolved in 2.26 g of distilled water was added dropwise to this while stirring, and stirring was continued for an additional 10 minutes to obtain a uniform mixed solution.

Next, in the second step, this mixed solution was placed in a polymethylpentene container with a diameter of 1.5 cm and a height of 10 cm, each IQi + 1 was placed, covered with a lid with a bottle hole of 1 mm in diameter, and kept at 70°C for hydrolysis. At the same time, dehydration condensation occurred to form a gel.

Further, the gel was dried by maintaining the temperature at 70° C. to obtain a drying power of 1 liter. Gold chloride is uniformly dispersed in this dried gel.

Next, as a third step, the dried gel taken out from the container is placed in a heating furnace with an oxygen atmosphere, and the temperature is raised from room temperature to 150°C over 2 hours while flowing 100Cc/win oxygen, and at this temperature for 5 hours. The remaining alcohol was removed. Subsequently, the temperature was increased at a heating rate of 12.5°C/h to 50°C.
The temperature was raised to 0°C and maintained at this temperature for 5 hours to burn off residual organic matter and decompose gold chloride into gold. Subsequently, the temperature was increased to 700°C at a rate of 12.5°C/h.

At this point, the atmosphere was replaced with helium gas and the temperature was increased to 100C.
,C,/rA1n, the temperature was raised to 1000°C at a rate of 12°5°C/h, and at this temperature 1
It was held for 0 hours. The gel was sintered by the above temperature program, and all the ultrafine particles were precipitated in the glass body.

The transmittance of a sample obtained by polishing this entire ultrafine particle-dispersed glass body to a thickness of 150 μm at wavelengths in the range of 250 nm to 2000 nm was measured. The measurement results are shown in FIG. 4. Since absorption occurred selectively in the wavelength range of 550 nm, it was confirmed that it can be used as an infrared transmission filter or a color filter.

Example 5 A glass body in which all ultrafine particles were dispersed was obtained in the same manner as in Example 4, except that dimethylformamide, which was not used in Example 4, was used.

That is, the starting materials include commercially available tetramethyl ortho silica-1- (TM01) and tetraethyl ortho silica-1- (TM01).
1.(TE01), ethanol, gold chloride, dimethylformamide (all of the above are special grade reagents), and distilled water.

In the first step, 3.04 g of TM01 was placed in a 200 ml polypropylene container in a water bath at 5°C.

TE01 4.16g, ethanol 9. ．． 20g.

3.2 g of dimethylformamide was added. A solution of 0.012 g of gold chloride dissolved in 2.66 g of distilled water was added dropwise to this while stirring, and stirring was continued for an additional 10 minutes to obtain a uniform mixed solution.

Next, in the second step, take IQml of this mixed solution into a polymethylpentene container with a diameter of 1.5 cm and a height of 10 cm, cover with a lid with a pinhole of 1 mm in diameter, and keep it at 70 °C and add water. Decomposition was accelerated and at the same time dehydration condensation occurred to form a gel.

The gel was further dried by maintaining the temperature at 70°C to obtain a dry gel. Gold chloride is uniformly distributed in this dried gel.

Next, as a third step, the dried gel taken out from the container is placed in a heating furnace with an oxygen atmosphere, and the temperature is raised from room temperature to 150°C over 2 hours while flowing 100cc/win oxygen, and at this temperature for 5 hours. The remaining alcohol was removed. Subsequently, the temperature was increased at a heating rate of 12.5°C/h to 50°C.
The temperature was raised to 0° C. and maintained at this temperature for 5 hours to allow combustion of residual organic matter and decomposition of gold chloride to gold. Subsequently, the temperature was increased to 700°C at a rate of 12.5°C/h. At this point, the atmosphere was replaced with helium gas, and from then on
C) 1 while flowing helium gas at ec/ll1n.
The temperature was raised to 1000° C. at a rate of 2.5° C./h and maintained at this temperature for 10 hours. The gel is sintered and made non-porous by the above temperature program, resulting in a diameter of 5III+! A quartz glass body with a height of 3 cm was produced, and all the ultrafine particles were uniformly precipitated in the glass body.

After polishing the obtained ultrafine particle-dispersed glass body, it was observed using a SEM (scanning electron microscope), and it was found that particles with a size of 0.5 μm or less were dispersed.

The transmittance of this glass body polished to a thickness of 150 μm was measured for wavelengths in the range of 250 nm to 2000 nm.
Since selective absorption occurred in the nm wavelength range, it was confirmed that it could be used as an infrared transmission filter or a color filter.

The concentration distribution of gold above and below this cylindrical glass body was measured using an E PMA (electron probe m).
1 cr.

analyzer). The results are shown in FIG. This revealed that the gold concentration distribution was horizontally uniform above and below the cylinder.

In addition, as a result of measuring the thermal properties and chemical durability of the obtained glass using a powder method, the glass transition point (Tg) was 850.
℃, water resistance (Dw) is 0.01%, acid resistance (Da) is 0.03% (Tg, Dw and Da are measured according to Japan Optical Glass Industry Standard JOGIS-1975), and heat resistance, chemical resistance It was found that the material has excellent physical durability and environmental resistance.

Example 6 Cupric chloride (CuC1g) instead of 0.012g of gold chloride
A copper oxide ultrafine particle dispersed glass body was prepared in the same manner as in Example 5 except that 0.14 g was used. The ultrafine particle-dispersed glass body thus obtained had ultrafine particles uniformly dispersed therein, similar to the ultrafine particle-dispersed glass body obtained in Example 5.

The transmittance of a sample obtained by polishing this glass body to a thickness of 150 μm with respect to wavelengths in the range of 250 nm to 2000 nm was measured. This measurement result is shown in Figure 6, 750n
Since absorption occurred selectively in a wavelength range shorter than m and 400 nm, it was confirmed that it can be used as a color filter.

Example 7 0.003 g of platinum hydrochloric acid solution instead of 0.012 g of gold chloride
A glass body containing ultrafine platinum particles was prepared in the same manner as in Example 5, except that an equivalent amount of platinum was used. The glass body thus obtained had ultrafine particles uniformly dispersed therein, similar to the glass body obtained in Example 5.

The transmittance of a sample obtained by polishing this glass body to a thickness of 150 μm with respect to wavelengths in the range of 25 Or+m to 11000 nm was measured. The results of this measurement are shown in Figure 7.
Since absorption occurred selectively in a wavelength range shorter than nm, it was confirmed that the material could be used as an infrared transmission filter or a color filter.

[Effects of the Invention] As described above, the ultrafine particle-dispersed glass of the present invention is made by dispersing ultrafine metal and/or metal oxide particles with a particle size of 1 μm or less in quartz glass, and therefore has excellent heat resistance and chemical durability. In addition to being excellent in environmental resistance, the ultrafine particles contain few impurities, so they are preferably used as infrared transmission filters and color filters that can be used even in high temperature and/or high humidity conditions.

Further, according to the method for producing ultrafine particle dispersed glass of the present invention,
Ultrafine particle-dispersed glass having the above-mentioned excellent properties can be obtained with high productivity without any equipment problems and with low energy consumption.

Further, according to a preferred embodiment of the method for producing ultrafine particle-dispersed glass of the present invention, the uniformity of the concentration distribution of ultrafine particles in the glass matrix can be particularly improved by using a silane coupling agent and/or dimethylformamide. can.

[Brief explanation of the drawing]

Fig. 1 is a diagram showing the X-ray diffraction peaks of the ultrafine manganese oxide particle dispersion glass obtained in Example 1 of the present invention, and Fig. 2 is a diagram showing the ultrafine manganese oxide particle dispersion obtained in Example 1 of the present invention. FIG. 3 shows the manganese oxide concentration distribution in the thickness direction and the lateral direction of the disc-shaped manganese oxide ultrafine particle-dispersed glass obtained in Example 2 of the present invention. Figure 4 is a diagram showing the transmittance curve of the ultrafine gold particle-dispersed glass obtained in Example 4 of the present invention, and Figure 5 is a diagram showing the transmittance curve of the ultrafine gold particle dispersed glass obtained in Example 5 of the present invention. FIG. 6 is a diagram showing the total concentration distribution above and below the dispersion glass. FIG. 6 is a diagram showing the transmittance curve of the copper oxide ultrafine particle dispersion glass obtained in Example 6 of the present invention. FIG. FIG. 7 is a diagram showing a transmittance curve of a platinum ultrafine particle-dispersed glass obtained in Example 7. Figure 3(b)

Claims (3)

[Claims] (1) An ultrafine particle-dispersed glass characterized by dispersing ultrafine particles of metal and/or metal oxide with a particle size of 1 μm or less in quartz glass. (2) A first step of preparing an aqueous solution containing an alkyl silicate and/or its hydrolyzate and a metal compound, and a second step of preparing a metal compound-containing silica gel by subjecting the aqueous solution to hydrolysis and dehydration condensation treatment. A third step of heating the gel to decompose the metal compound into metal and/or metal oxide, and then sintering the gel to obtain quartz glass in which ultrafine particles of metal and/or metal oxide are dispersed. The method for producing ultrafine particle dispersed glass according to claim (1), characterized by comprising the following steps. (3) The method for producing ultrafine particle-dispersed glass according to claim (2), wherein the aqueous solution prepared in the first step further contains a silane coupling agent and/or dimethylformamide.