JPH08283024A - Production of glass or ceramic and device therefor - Google Patents

Abstract

PURPOSE: To produce a glass or ceramic without any crack, with the shape of the metal distribution controlled precisely and having the distributed refractive index enhanced in the reproducibility and reliability of the optical characteristic in the method for producing the glass or ceramic by dipping a porous body in a soln. and then drying or calcining the body. CONSTITUTION: A gas jet device 6 is arranged on the lower face of a vessel 1 fitted with a soln. 2. The jet device is positioned below a porous body 3 and connected to a compressor 8 through a gas flow controller 7. Compressed air is delivered from the compressor 8, and the discharge of the compressed air is adjusted by the controller 7. Besides, the position of the jet device 6 is appropriately changed. The compressed air jetted from the jet device is bubbles in the soln. 2, the bubble is allowed to ascend in the soln. 2, and the soln. is agitated. The discharge and discharge position of the gas are changed with time to control the agitating speed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus capable of favorably treating a porous body which is a precursor of glass and ceramics.

[0002]

2. Description of the Related Art In order to prevent cracking of a gel porous body produced by the sol-gel method, the solution in the pores of the gel porous body is replaced with a solution having a small surface tension. In order to perform this substitution, in Japanese Patent Publication No. 2-39454, the gel porous body is immersed in a solution such as alcohol.

Further, Japanese Examined Patent Publication No. 5-277575, Japanese Unexamined Patent Publication No. 61-183136, and Japanese Examined Patent Publication No. 61-5661.
The publication discloses a method for producing a glass body having a refractive index distribution by the sol-gel method and the stuffing method.
Both methods have a step of imparting a concentration distribution to a metal component in a porous body produced by hydrolysis of a metal alkoxide, polycondensation, pH adjustment of an oxide fine particle dispersion solution, or leaching of a phase-separated glass. Then, the porous body having this concentration distribution is dried and fired to produce a glass body having a refractive index distribution. At this time, the step of introducing the metal component into the porous body, the step of imparting the concentration distribution, and the step of fixing the concentration distribution are all performed by immersing the porous body in the solution. On the other hand, JP-A-3-295818
The publication discloses that the solution is stirred when the porous body is dipped in the solution, but this stirring is performed using a stirrer chip or a stirring blade.

[0004]

When substituting the solution in the porous body, simply immersing the porous body in the dipping solution results in a slow exchange rate between the solution in the porous body and the dipping solution, which results in rapid replacement. It cannot be replaced and cannot be dipped efficiently. For this reason, the dipping solution is stirred with the stirrer tip or the blade as described above, but when the long porous body is subjected to the liquid immersion treatment in the elongated container, it is difficult to sufficiently stir the upper part and the lower part of the solution. Therefore, the liquid immersion process requires a long time. Further, in order to sufficiently stir, when the stirrer chip or the blade is vigorously moved, a strong water flow is generated, which causes a problem that the porous body vibrates more than necessary and is damaged and cracked.

On the other hand, when the porous body is dipped in the solution, the liquid immersion treatment can be completed by a long-time dipping when a homogeneous glass or ceramics is produced without efficient stirring. However, particularly when imparting a composition distribution, when the upper and lower portions are not efficiently stirred, for example, when a rod-shaped porous body is subjected to liquid immersion treatment using a slender container such as a test tube, Since the lower liquid is well agitated, the distribution is imparted even to the inside of the porous body, but the upper liquid is not well agitated, so that there is a problem that the distribution is limited to the outer peripheral portion. FIG.
Reference numeral 1 shows a two-dimensional refractive index measured when a glass body manufactured by such a method is cut along a plane including the optical axis in the optical axis direction, and shows a refractive index distribution represented by an isoptric index line. With such a distribution, the range in which it can be used as a lens is limited, and many lenses cannot be manufactured from one rod, but the yield is poor.

The present invention is used for the production of glass or ceramics in which such a porous body is dipped in a solution and then dried or fired, and its purpose is to provide a porous body which is a precursor of glass and ceramics. It is an object of the present invention to provide a method and an apparatus capable of efficiently manufacturing a body without cracking. Further, the present invention, the metal distribution in the porous body can be precisely controlled, thereby the refractive index, the refractive index difference,
It is an object of the present invention to provide an apparatus and a method for easily producing a porous body that is a precursor of glass or the like having a refractive index distribution with high reproducibility and reliability in optical characteristics such as dispersion characteristics.

[0007]

Means and Actions for Solving the Problems The method of the present invention for achieving the above-mentioned object is a method for producing glass or ceramics, which comprises subjecting a porous body to a dipping treatment in a solution, followed by drying or firing. It is characterized in that the solution in which is immersed is stirred by air bubbles. Further, in the present invention, the step of immersing the porous body in the solution is applied to the step of imparting the concentration distribution of the substance in the porous body. Further, as the porous body, one prepared by the sol-gel method is used.

FIG. 1 shows the basic structure of the present invention, in which a solution 2 is stored in a container 1 and a porous body is immersed in the solution 2. A gas outlet 4 is formed below the porous body 3 in the container 1. In FIG. 3A, the outlet 4 is arranged in the center of the bottom surface of the container 1, and in FIG. All of these outlets 4 are connected to a gas generator, a gas cylinder, a compressor, etc., and the gas is blown into the solution 2 as bubbles 5. As a result, gas bubbles are generated in the solution 2 in which the porous body 4 is immersed through the gas outlet provided in the lower portion of the porous body, and move upward in the solution 2. By this movement, the solution 2 moves as indicated by the arrow, and the solution 2 as a whole is stirred.

The stirring speed can be controlled by the amount of bubbles, the size of bubbles, the number of bubbles, and the like. For example, when the stirring speed is increased, it can be easily performed by increasing the amount, size and number of bubbles. The amount of bubbles can be controlled to be constant by supplying gas through a flow rate control device such as a mass flow controller, and the agitation speed can be changed by gradually changing the flow rate. You can also In addition, a concentration sensor for the solution and a plurality of gas outlets are provided, and the amount of gas blown out from each gas outlet is separately controlled by a flow rate control device via a CPU or the like to prevent uneven stirring. You can also

In the present invention, to ensure that the solutions are well mixed,
The gas outlet can be used as a nozzle, or the direction, number, and size of the nozzles can be switched for a certain period of time or randomly, and the gas outlet can move in the immersion liquid container. The speed and stirring efficiency can also be changed. The size of the bubble can be changed by the amount of gas, the viscosity of the liquid, the surface tension, etc., but since the liquid is usually determined for various treatments of the porous body,
To control the bubble size, it is effective to change the diameter of the gas outlet. The diameter may be a small hole of about 0.1 mm to 10 mm. The portion from which the gas is blown may have any shape, and small holes may be aggregated to have various shapes such as a plate shape, a disk shape, a donut shape, and a star shape as a whole. This is selected from the viewpoint of ease of molding and stirring efficiency.

When the immersion treatment is performed with the columnar or prismatic porous body standing upright, it is desirable to dispose a disk-shaped or donut-shaped gas outlet in the lower part of the porous body. When performing immersion treatment with a cylindrical, prismatic, or plate-shaped porous body laid sideways, place a plate-shaped gas outlet at the bottom of the porous body, and place a nozzle near the top of the porous body. By arranging the gas outlet in the shape of a bubble, the bubbles can make good contact with the porous body.

According to the present invention, a large amount of air bubbles are generated by such a structure, and thus, Japanese Patent Application No. Hei 6-31663.
It can also be used for liquid immersion treatment of a porous body such as No. 5, and versatility is improved.

With the above structure, when the porous body is immersed in liquid, the gas rises to the liquid surface while stirring the solution. Therefore, even when the container is elongated, the stirring is sufficiently performed, and the liquid immersion step can be efficiently performed. Further, since the mixture is vigorously stirred, even if a large amount of bubbles are generated, the porous body cannot be scratched and cracks do not occur. At this time, when producing a homogeneous glass, the gas used is inert to the porous body and the components contained in the porous body, for example,
Inert gases such as air, oxygen, carbon dioxide, etc., nitrogen, helium, etc., and mixed gas thereof are preferable. Further, these gases may include a liquid gas that is immersed. The stirring speed can be controlled by the amount of foam, the size of foam, and the like.

In the present invention, the step of immersing the porous body in the solution can be used in the step of imparting a concentration distribution of the substance in the porous body. The point of giving the composition distribution in this porous body will be described. In this step, a certain metal species is selectively eluted from the porous body, or a certain metal species in the porous body is exchanged with a certain metal species in the distribution providing liquid to give a composition distribution. At this time, in particular, unless the stirring is performed efficiently, the composition distribution varies depending on the porous body portion (for example, the rod-shaped upper portion and lower portion). For example, when a solution is filled in an elongated container such as a test tube and a rod-shaped porous body is immersed in this solution to give a composition distribution, the liquid at the bottom of the container is well agitated. However, since the liquid in the upper portion is not stirred well, the distribution is limited to the outer peripheral portion of the upper portion of the porous body. Therefore, the two-dimensional refractive index when the manufactured glass body is cut along a plane including the optical axis in the optical axis direction is measured, and the distribution is as shown in FIG.

From the above, efficient stirring is required to obtain the distribution of the same shape at any position and to obtain a distribution with good reproducibility. On the other hand, in the present invention, the gas is jetted into the solution, and the gas rises to the liquid surface by being blown into the solution. Therefore,
The stirring can be sufficiently performed, and the composition distribution can be efficiently provided. The gas to be blown is, for example, not only air, oxygen, nitrogen, helium, carbon dioxide, a gas of an immersion liquid or the like, or a mixed gas thereof, but one that dissolves the components in the porous body, for example, an acidic gas such as hydrogen chloride. Blowing in a basic gas such as gas or ammonia is also effective.

The porous material used in the present invention is a so-called gel obtained by gelling a sol obtained by hydrolyzing a silicon alkoxide or the like, a soot produced by the CVD method or the VAD method, a phase separation method, or the like. Porous glass can be used. In this case, since the porous body produced by the sol-gel method often has low mechanical strength and may be destroyed by vigorous stirring, the present invention in which the solution is stirred by gas is very effective. is there.

By fixing, drying, and baking the distribution of the porous material obtained by these operations, a refractive index distribution with high reproducibility and reliability in optical characteristics such as refractive index, refractive index difference, and dispersion characteristics can be obtained. It is possible to easily manufacture the glass body having the glass body. The porous body can be applied to a shape other than a simple rod shape such as an elliptical shape, and can also be applied to a thin film and a thick film such as an optical waveguide.

[0018]

【Example】

(Embodiment 1) FIG. 2 shows Embodiment 1 of the present invention. In this device, a gas ejecting body 6 is arranged on the lower surface of a container 1 filled with a solution 2. The jet body 6 is arranged so as to be located below the porous body 3, and is connected to the compressor 8 via the gas flow rate control device 7. The compressor 8 generates compressed air, and the gas flow rate control device 7 adjusts the amount of compressed air blown out. Also,
The position of the ejection body 6 can be changed appropriately.

With this structure, air is jetted from the jetting body 6, the air becomes bubbles in the solution 2, and the bubbles rise in the solution to stir the solution. This device can control the stirring speed by changing the amount of gas blown out and the position at which the gas is blown out with time. Further, the stirring speed can also be controlled by setting the size and number of ejection ports of the ejection body 6 in advance. The ejection body 6 in the present embodiment is a disk shape of 70 mm and has a size of about 1 mm.
The spouts of the size are arranged concentrically. Moreover, the number of ejection ports is set to about 500.

Next, the use of this embodiment will be described. Tetramethoxysilane 100 ml, tetraethoxysilane 100
ml was mixed, 84 ml of 1/100 N hydrochloric acid was added thereto, and the mixture was stirred at room temperature for 1 hour to carry out partial hydrolysis. To this solution, a 1.25 mol / l lead acetate aqueous solution 378 m
A solution in which 1 and 52 ml of acetic acid were mixed was added and vigorously stirred for 10 minutes to prepare a sol. After allowing this sol to stand for 5 minutes, it was dispensed into a Teflon container having an inner diameter of 50 mm and the temperature was 30 ° C.
The gelation was aged by leaving it to stand in the constant temperature bath for 3 days.

The obtained gel having a diameter of 30 mm was inserted into the apparatus shown in FIG. 2, and isopropanol: water = 8: 60 ° C.
2 (volume ratio, hereinafter solvent ratio will be referred to as volume ratio) mixed with 0.61 mol / l lead acetate solution, 21
Air was continuously blown at a flow rate of / min to remove acetic acid and age the gel. Further, for the apparatus shown in FIG. 2, isopropanol, isopropanol: acetone = 8:
The solutions were exchanged in the order of 2, 5: 5, and acetone, and while continuing to blow air into each solution, the gel was contacted for 24 hours each, thereby precipitating and fixing lead acetate microcrystals in the gel pores. . When this gel was dried and fired, a glass body having a diameter of about 20 mm and no cracks could be obtained.

Example 2 The sol prepared in the same manner as in Example 1 was allowed to stand for 5 minutes, then dispensed into a Teflon container having an inner diameter of 5 mm and allowed to stand in a constant temperature bath at 30 ° C. for 3 days. The gel was aged.

The obtained gel having a diameter of 3 mm was treated with a mixed solvent of isopropanol: water = 8: 2 at 60 ° C. for 0.6.
The solution was brought into contact with a 1 mol / l lead acetate solution to remove acetic acid and age the gel. In the apparatus shown in FIG. 2, this gel was subjected to isopropanol, isopropanol: acetone = 8:
The air was blown in the order of 2, 5: 5 and acetone for 24 hours each. In this case, air was blown while changing the position of the blowout port every 10 minutes, thereby precipitating and fixing lead acetate microcrystals in the gel pores.

Next, potassium acetate 0.305 mol / l
The obtained homogeneous gel was immersed for 20 minutes while continuously blowing air at a flow rate of 0.5 l / min into a solution obtained by mixing ethanol solution of 0.153 mol / l of acetic acid with each other to give a concentration distribution. As a result, it was possible to give the lead component a convex distribution and the potassium component a concave distribution. This gel was used for isopropanol and isopropanol: acetone = 8:
The distribution was fixed by contacting 2, 5: 5, and then acetone for 6 hours each.

After drying this gel at 30 ° C. for 3 days, 5
By heating to 70 ° C. and sintering, a colorless transparent glass body having a crack-free diameter of 1.8 mm was obtained. When the refractive index of this glass body was measured, it was found that the refractive index distribution was such that the refractive index monotonically decreased from the central portion toward the outer peripheral portion.

[0026] Similarly, 10 lots are treated as one lot and 20
When a lot production test was conducted, the difference in the refractive index distribution between the rods was practically no problem at any part of the glass body, and a glass body having the same refractive index distribution was used. I was able to get it.

(Comparative Example 1) A gel was prepared in the same manner as in Example 2, and the rod-shaped gel was put into an ethanol solution of potassium acetate 0.350 mol / l and acetic acid 0.153 mol / l, which was stirred with a stirrer tip. In a standing state, it was immersed for 20 minutes to give a convex distribution to the lead component and a concave distribution to the potassium component. This gel is used for isopropanol, isopropanol: acetone = 8: 2, 5: 5,
Acetone was contacted with each other for 6 hours to fix the distribution, and then fired.

When several flat lenses were cut out from this glass rod and the refractive index distribution was measured, there were variations in the refractive index difference and dispersion characteristics as shown in FIG. That is, as shown in (a) of the same figure, the interval of the iso-refractive index lines of the glass body cut out from the upper part during distribution is wide, and as shown in (b) of the same figure, the equal refraction index of the glass body cut out from the lower part The interval between the rate lines was narrow, and the optical characteristics differed depending on the cut out part.

(Embodiment 3) FIG. 4 shows an apparatus used in Embodiment 3 of the present invention, and the same portions as those in FIG. 2 are designated by the same reference numerals. This device is connected to a gas cylinder 9 via a gas ejecting body 6 and a gas flow rate control device 7. In this device, a plurality of gas cylinders 9 are provided so that they can be switched on the way. In this device, the stirring speed can be controlled by changing the ejection amount of gas and by changing the size and the number of ejection ports of the ejection body 6.

In this example, a gel was prepared in the same manner as in Example 2, the gel was set in the apparatus shown in FIG. 4, and an ethanol solution containing 0.5 mol / l potassium acetate and 0.2 mol / l acetic acid was mixed. The distribution-imparting solution had a flow rate of 0.51 / mol for the first 10 minutes, and 2 l / mol for the subsequent 10 minutes.
He gas was continuously blown in at a flow rate of min. As a result, the lead component was given a convex distribution and the potassium component was given a concave distribution.
By fixing the distribution of the obtained gel, drying, and sintering,
It was possible to obtain a colorless and transparent glass body having a diameter of 1.8 mm, which was all crack-free. Then, when the optical characteristics of the manufactured glass body were measured, it was found that the glass body had a refractive index distribution with good reproducibility.

Example 4 Silicon tetrachloride SiC was used as a raw material for silicon, zirconium, barium and sodium.
l ₄ , zirconium tetrachloride, barium nitrite Ba (NO
_{2) 2} · 2H ₂ O, it was used sodium acetate. Flame hydrolysis of silicon tetrachloride and zirconium tetrachloride was performed to prepare a soot of zirconia silica having an outer diameter of 2 mm. By contacting the obtained soot with a mixed solution of barium nitrite, ethanol, and water, after uniformly containing barium nitrite, contacted with a solution in which ethanol and lactic acid are dissolved,
Microcrystals of barium nitrite were fixed.

As a distribution-imparting solution, a solution prepared by dissolving sodium acetate in methanol was filled in the container 1 shown in FIG. As the gas cylinder 9, an air cylinder and a nitrogen gas cylinder were used. Then, soot is dipped in the solution 2 and 2 l / mi
Nitrogen gas was continuously blown for 15 minutes at a flow rate of n to give the barium component a convex distribution and the sodium component a concave distribution.
After that, the solution was replaced with a mixed solution of ethanol and lactic acid, the soot was immersed again while continuing to blow air, and the microcrystals of barium nitrite and sodium nitrate were fixed, dried and fired to give a diameter of 1. A 2 mm transparent glass body was obtained. The above steps were repeated, but the distribution in the radial direction of any glass body was similar.

(Embodiment 5) FIG. 5 shows an apparatus used in this embodiment, and the same elements as those of the apparatus of FIG. 4 are designated by the same reference numerals. This apparatus uses the stirring blade 10 in addition to the apparatus shown in FIG. 4, whereby the stirring efficiency is improved.

Tetraethoxysilane, ethanol and 2
Normal hydrochloric acid was mixed to partially hydrolyze the silicon alkoxide. Next, a solution of zirconium tetraisopropoxide dissolved in isopropanol was added and stirred. Then, a mixed solution of sodium nitrate, water, isopropanol, dimethylformamide, and ammonia water was dropped into this solution to prepare a sol. The obtained sol was dispensed into a Teflon container having an inner diameter of 4 mm and allowed to stand in a constant temperature bath at 30 ° C. for 3 days to mature the gelation.

The obtained gel was placed in a nitrogen gas in the apparatus shown in FIG.
While blowing in H of 3 specified concentration ₂SO_Four30 minutes in
I left it. In addition, do not blow nitrogen gas into the device in FIG.
It was dipped in isopropanol to fix the distribution. this
By fixing the distribution of the gel, drying, and sintering,
Crack-free transparent glass body with a diameter of 1.6 mm
I was able to get Measure the radial distribution of this glass body
As a result, both the zirconia and sodium components were the same.
It was a glass body with the same convex distribution. In this example
Had a refractive index distribution with the same optical characteristics with good reproducibility
A glass body could be obtained.

(Comparative Example 2) The gel produced in the same manner as in Example 5 was immersed in H ₂ SO ₄ having a concentration of 3N for 30 minutes, which was stirred only by the blade 10 to impart distribution. This was immersed in isopropanol to fix the distribution. By subjecting this gel to distribution fixing, drying and sintering, it was possible to obtain a colorless transparent glass body having a diameter of 1.6 mm, which was crack-free. However, when the radial distribution of each glass body was measured, the distribution shape was different for each lot for both the zirconia component and the sodium component, and it was not possible to obtain a glass body with optical characteristics having the same refractive index distribution. .

(Embodiment 6) FIG. 6 shows an apparatus used in this embodiment, and the same elements as those of the apparatus of FIG. 4 are designated by the same reference numerals. This device is equipped with an ethanol tank 11 for supplying ethanol to the container 1 in addition to the device of FIG. Further, a liquid level sensor 12 that detects the liquid level of the solution 2 and a concentration sensor 13 that detects the concentration of the solution 2 are provided. These sensors 12 and 13 are CPUs
The detected value is output to 14, and its operation is controlled by the CPU 14. Reference numeral 15 is a discharge pipe having a discharge valve 16, and the opening / closing of the discharge valve 16 is controlled by the CPU 14. Reference numeral 17 denotes a valve that opens and closes the ethanol tank 11 and is controlled by the CPU 14. The CPU 14 of this embodiment drives the liquid level sensor 12, the concentration sensor 13, and the discharge valve 16 to replace the immersion liquid of the porous body and control the amount. Further, the stirring speed can be controlled by changing the size and number of the ejection ports of the ejection body 6.

In this example, first, 15 mol% of Ti was used.
To 1 mol of Si (OCH ₃ ) ₄ containing ( OnC ₄ H ₉ ) ₄ , 4.5 mol of ethanol and 1/100 of 4 mol
A prescribed aqueous HCl solution was added to cause hydrolysis, and gelation was performed in a Teflon-coated container having an inner diameter of 2 mm to prepare a wet gel. Using the apparatus of FIG. 6, as the distribution imparting liquid,
While continuing to blow hydrogen chloride gas into pure water at a flow rate of 1 l / min, this gel was immersed, and after 20 minutes, the solution was neutralized by switching to NH ₃ gas and distribution was stopped. Then, this solution was exchanged with ethanol, and the gel having distribution was washed to remove ammonium chloride. And 10
Dry at 0 ℃, sinter up to 1030 ℃ in an electric furnace,
When vitrified, a glass rod having a diameter of about 0.7 mm was obtained. When this glass rod was cut at a right angle to the axis and the Ti concentration distribution in the radial direction was measured, it had a substantially parabolic concentration distribution. Furthermore, when the refractive index distribution of this glass rod was measured, the refractive index at the center was high,
It had a parabolic shape with a low refractive index in the peripheral portion. FIG. 7 shows the refractive index distribution of this example.

Example 7 A gel was prepared in the same manner as in Example 6, and hydrogen chloride gas was added to pure water as a distribution-imparting liquid for the first 10 minutes at a flow rate of 1 l / min using the apparatus shown in FIG.
While continuing to blow nitrogen gas at a flow rate of 3 l / min for the next 10 minutes, the gel was immersed, and after 20 minutes, the solution was neutralized by switching to NH ₃ gas and distribution was stopped. Then, this solution was exchanged with ethanol, and the gel having distribution was washed to remove ammonium chloride. And 1
When dried at 00 ° C., sintered to 1030 ° C. in an electric furnace and vitrified, a glass rod having a diameter of about 0.7 mm was obtained. FIG. 8 shows a characteristic diagram obtained by cutting the glass rod at right angles to the axis and measuring the refractive index distribution in the radial direction. Examples 6 and 7 described above show that the distribution shape can be controlled by controlling the gas flow rate.

(Embodiment 8) FIG. 9 shows an apparatus used in this embodiment, and the same elements as those of the apparatus of FIG. 2 are designated by the same reference numerals. In this device, ejecting bodies 6 for ejecting compressed air are arranged on both sides below the porous body 3 so that bubbles do not come into direct contact with the porous body 3. In this structure, the bubbles from the ejecting body 6 rise in the solution 2 along the inner wall of the container 1, so that the solution 2
From the outside to the inside.

Using this apparatus, a gel was prepared in the same manner as in Example 1 and was immersed in the same manner as in Example 1. When this gel was dried and fired, a glass body having a diameter of about 20 mm and no cracks was obtained.

(Embodiment 9) FIG. 10 shows an apparatus used in this embodiment, and the same elements as those shown in FIG. 9 are designated by the same reference numerals. In this device, in addition to the ejection body 6 of FIG. 9, a ejection body 19 is arranged on the side surface of the container 1.
The ejection body 19 is arranged laterally of the porous body 3,
The bubbles generated from the ejection body 19 and the ejection body 6 on the bottom surface rise along the inner wall of the container 1, and the rise causes the solution 2 to be stirred from the outside to the inside. Also in this example, the bubbles do not come into direct contact with the porous body 3.

Using the apparatus shown in FIG. 10, a gel was prepared in the same manner as in Example 1 and immersed in the same manner as in Example 1. When this gel was dried and fired, the diameter was about 20 mm.
A glass body without cracks was obtained.

[0044]

According to the present invention, bubbles are generated in the solution to stir the solution, so that a porous body without cracks can be easily manufactured. Further, the shape of the metal distribution in the porous body can be precisely controlled, and as a result, a precursor of a glass body having a refractive index distribution with high reproducibility and reliability in optical properties such as refractive index, refractive index difference, and dispersion property. It is possible to easily manufacture a porous body having a composition distribution that becomes a body.

[Brief description of drawings]

1A and 1B are cross-sectional views illustrating the operation of the present invention.

FIG. 2 is a sectional view of an apparatus used in an embodiment of the present invention.

3A and 3B are refractive index distributions of a glass rod manufactured in Comparative Example 1, where FIG. 3A is a sectional view of a lower portion and FIG. 3B is a sectional view of an upper portion.

FIG. 4 is a cross-sectional view of an apparatus used in Example 3.

5 is a sectional view of an apparatus used in Example 5. FIG.

FIG. 6 is a sectional view of an apparatus used in Example 6.

FIG. 7 is a cross-sectional view showing the refractive index of a glass rod manufactured according to Example 6.

FIG. 8 is a cross-sectional view showing the refractive index of the glass rod manufactured according to Example 7.

FIG. 9 is a sectional view of an apparatus used in Example 8.

FIG. 10 is a sectional view of an apparatus used in Example 9.

FIG. 11 is a cross-sectional view of a refractive index distribution of a glass body manufactured by a conventional method.

[Explanation of symbols]

 1 Container 2 Solution 3 Porous Body 4 Gas Outlet 5 Bubble 6,19 Ejector

Claims (4)

[Claims] 1. A method for producing glass or ceramics, which comprises immersing a porous body in a solution and then drying or firing the glass or ceramics, wherein the solution in which the porous body is immersed is stirred with bubbles. Method of manufacturing ceramics. 2. The method for producing glass or ceramics according to claim 1, wherein the step of immersing the porous body in a solution is a step of imparting a concentration distribution of a substance in the porous body. 3. The method for producing glass or ceramics according to claim 1, wherein a porous body prepared by a sol-gel method is used for the immersion. 4. An apparatus for producing glass or ceramics, comprising means for generating bubbles in a solution in which a porous body is immersed.