JPH04243505A - Porous glass coated inorganic body and preparation thereof - Google Patents

Abstract

PURPOSE:To prepare a porous glass coated inorg. body excellent in resistance to corrosion, abrasion and heat, having higher strength as compared with porous glass obtained by a conventional sol.gel method, having both of excellent contact efficiency and pressure loss resistance and capable of developing physiochemical function such as adsorbing function over a long period of time. CONSTITUTION:A porous glass coated inorg. body wherein a porous glass coating layer is provided to the surface of an inorg. support by a sol.gel method is prepared by a method wherein a mixture of an organometallic compound- containing solution and an org. polymer is applied to the surface of the inorg. support and the coated support is heated to 500-800 deg.C not only to vetrify the dried gel but also to remove the org. polymer in said gel to form a porous glass coating layer.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention relates to a porous glass-coated inorganic body and a method for producing the same, and more particularly, the present invention relates to a porous glass-coated inorganic body and a method for manufacturing the same. The present invention relates to a porous glass-coated inorganic body that exhibits such physicochemical functions as well as excellent corrosion resistance, abrasion resistance, and heat resistance and is suitable for use under severe conditions, and a method for producing the same.

0002

[Prior Art] Porous materials that exhibit physicochemical functions such as adsorption functions have fine pores, for example, pore radius: 5 to 10 Å.
It is necessary to have a large number of minute pores. Conventionally, such materials include organic porous materials made of organic resins,
Inorganic porous materials made of inorganic substances such as activated carbon, zeolite, and silica gel are also well known. Incidentally, since it is easy to manufacture these in the form of granules or small pieces, and it is difficult to manufacture them into complex shapes, many of these are in the form of granules or small pieces.

0003

[Problems to be Solved by the Invention] However, the conventional organic porous materials described above are inferior in corrosion resistance, abrasion resistance, and heat resistance, and therefore cannot be suitably used in industrial processes. On the other hand, the conventional inorganic porous materials have superior corrosion resistance, abrasion resistance, and heat resistance compared to the organic porous materials, but they have low strength and are made into powder or granular materials to increase contact efficiency with gases and liquids. When used as a body, it suffers from large pressure loss and is difficult to handle. Incidentally, if the material is made into a lump, it becomes difficult to cause pressure loss and becomes easier to handle, but there is a problem that the above-mentioned contact efficiency deteriorates and the function deteriorates.

Porous glass obtained by a phase separation method or a sol-gel method can be considered as a porous material capable of improving the above-mentioned difficulties. The former phase separation method heat-treats glasses containing various metal oxides at temperatures below their softening point for a long time to separate them into a skeleton metal oxide phase and a soluble metal oxide phase. Porous glass is produced by eluting the phase with acid. The latter sol-gel method is a method in which glass is synthesized by drying and gelling an organometallic compound-containing solution and then heating and baking the solution, and can produce porous glass. Note that if the heating and firing temperature is set too high, the glass becomes dense due to the sintering reaction and the pores disappear, so that porous glass cannot be obtained.

[0005] Such porous glass has better wear resistance and strength than the above-mentioned inorganic porous materials. However, contact efficiency and pressure loss resistance are still insufficient, and it is not possible to have excellent contact efficiency and pressure loss resistance at the same time. That is, if the powder or granular material has a high contact efficiency, the pressure loss resistance becomes insufficient, and if the particle size is increased to increase the pressure loss resistance, the contact efficiency becomes insufficient.

[0006] In addition, in the conventional phase separation method described above, the pore radius: 20
There is a problem in that it is not possible to manufacture products with micropores of Å or less. In the above conventional sol-gel method, pore radius: 1
It is not easy to manufacture products with micropores of about 0 Å, and the specific surface area of the pores is important (the surface area of the pores per unit weight of glass determined by the pore radius, pore size, number, etc.) There is a problem with the lack of reproducibility.

The present invention has been made in view of the above circumstances, and its purpose is to solve the problems of the prior art, provide excellent corrosion resistance, abrasion resistance, and heat resistance, and achieve the above-mentioned properties. The purpose of the present invention is to provide a porous glass-coated inorganic body that has higher strength than porous glass obtained by the conventional sol-gel method and can simultaneously have excellent contact efficiency and pressure loss resistance, and a method for producing the same. be.

[0008]

Means for Solving the Problems In order to achieve the above object, a porous glass-coated inorganic body and a method for producing the same according to the present invention have the following configuration.

That is, the porous glass-coated inorganic body according to claim 1 comprises an inorganic support and a porous glass coating layer formed by applying an organic metal compound-containing solution to the surface of the support and firing the coating. This is a porous glass-coated inorganic body characterized by the following. The porous glass-coated inorganic body according to claim 2 is the porous glass-coated inorganic body according to claim 1, wherein the radius of the pores of the porous glass coating layer is 10 Å or less.

The method for producing a porous glass-coated inorganic body according to claim 3 includes applying a mixture containing an organometallic compound-containing solution and an organic polymer to the surface of an inorganic support, drying and gelling the mixture, and then drying and gelling the mixture. A method for producing a porous glass-coated inorganic body, which comprises vitrifying it by heating at a temperature of 500 to 800°C and removing organic polymers in the dried gel to form a porous glass coating layer. .

[0011]

[Function] As described above, the porous glass-coated inorganic body of the present invention consists of an inorganic support and a porous glass coating layer formed by applying an organic metal compound-containing solution to the surface of the support and baking it. . In this way, the porous glass coating layer is
Since it is formed by coating and firing a solution containing an organic metal compound, it can have properties similar to porous glass obtained by the so-called sol-gel method. In addition, the inorganic support can be made of materials such as alumina, carbide, ceramics, glass, etc., so it can have excellent corrosion resistance and heat resistance, as well as high strength and hardness. It can have high pressure loss resistance.

[0012] Therefore, the porous glass-coated inorganic body according to the present invention has excellent corrosion resistance, abrasion resistance, and heat resistance similar to the porous glass obtained by the conventional sol-gel method, and also It has higher strength than porous glass obtained by the sol-gel method, and can have excellent contact efficiency and pressure loss resistance at the same time. In other words, since the porous glass coating layer is supported by an inorganic support with excellent pressure loss resistance, the overall pressure loss resistance is excellent, and therefore, even if the dimensions and shape have high contact efficiency, a sufficiently high level of pressure resistance can be achieved. It is possible to ensure loss resistance, and simultaneously have excellent contact efficiency and pressure loss resistance.

[0013] The radius of the pores in the porous glass coating layer is 10
When the thickness is less than Å, physicochemical functions are better exhibited, so that a higher level of excellent contact efficiency and pressure loss resistance can be achieved at the same time. On the other hand, if it exceeds 10 Å, the contact efficiency decreases as the specific surface area of the pores decreases. Therefore, it is desirable that the radius of the hole be 10 Å or less as described above.

[0014] The shape of the inorganic support is not limited, and may be in the form of particles or small pieces, as well as powder, beads, plates, nets, etc.
You can use grid-like or special-shaped ones. The constituent material of the inorganic support is not limited and may be any material as long as it has excellent corrosion resistance and heat resistance as well as high strength and hardness, such as alumina, carbides, nitrides, ceramics, glass, ceramic raw materials, inorganic pigments for ceramics, and inorganic materials. Fibrous materials, non-oxide-based inorganic materials, metals, carbon-based materials, or mixtures or composites thereof can be used.

[0015] Since the porous glass coating layer is obtained by coating and baking a solution containing an organic metal compound, it can be provided on the support with good adhesion regardless of its shape. Various shapes can be used, and therefore, the porous glass-coated inorganic body according to the present invention is not limited to the granular or flaky shape as in the case of conventional inorganic porous materials such as activated carbon, but can be used in various shapes. It has the advantage that it can be used as Furthermore, since the above-mentioned firing temperature is relatively low, there is also the advantage that production can be performed with less heating energy.

The above-mentioned organometallic compound-containing solution is a solution that necessarily contains an organometallic compound, and may further contain an inorganic salt. Alcohol and/or water can be used as a solvent. The organometallic compound is typically a metal alkoxide, but is not particularly limited. Examples of metal alkoxides include sodium ethoxide, calcium ethoxide, and silicon ethoxide.

In order to produce the porous glass-coated inorganic body according to the present invention, an organic metal compound-containing solution is applied to the surface of the inorganic support, dried and gelled, and then heated and baked to form a porous glass coating layer. Just let it form. At this time, the pore diameter of the porous glass coating layer can be changed by adjusting the heating and firing temperature, etc., but as mentioned above, it is relatively difficult to reduce the pore radius to 10 Å or less, and the specific surface area of the pores Reproducibility may be lacking.

Therefore, various studies were conducted to improve these points, and the method for producing a porous glass-coated inorganic body according to claim 3, that is, a method for producing a porous glass-coated inorganic body, in which an organic metal compound-containing solution and an organic polymer are coated on the surface of an inorganic support. After applying a mixture containing the above and drying it into a gel, heating it at a temperature of 500 to 800°C to vitrify it and removing the organic polymer in the dried gel to form a porous glass coating layer. The characteristic method for producing a porous glass-coated inorganic body is effective, and according to this method, the pore radius can be reliably and easily reduced to 10 Å or less, and the reproducibility of the specific surface area of the pores can be improved. It turned out to be like this. The reason for this will be described below.

[0019] The above organic polymer generally has a length of 5 to 20
It is an extremely small substance with an elongated shape on the order of Å, and can be uniformly dispersed in a solution containing an organometallic compound. Therefore, the above-mentioned mixture is an organometallic compound-containing solution containing such an organic polymer, and when this is applied and dried to form a gel, it becomes a dry gel in which the organic polymer is uniformly dispersed.

[0020] When the dried gel is vitrified by heating at a temperature of 500 to 800°C and the organic polymer in the dried gel is removed, micropores are formed. In other words, the dry gel is porous and contains organic polymers, and since the organic polymers coexist with the pores of the gel itself, the heating described above first removes the organic polymers from those near the pore surface of the gel. The organic polymer is gasified and discharged from the gel, and a gas passage is formed in the gel during the vitrification process, and through this, the organic polymer is sequentially discharged (removed) from the glass, and the removed part itself becomes an elongated, extremely small In addition to remaining as pores and forming elongated micropores,
The micropores of the dry gel itself remain without becoming porous, and more micropores are formed, so the pore radius is 5 to 10.
It can be about Å. Here, the heating temperature of the dry gel is 50
The reason why the temperature is 0 to 800°C is that if it is less than 500°C, vitrification will be insufficient and the strength and corrosion resistance will deteriorate.
This is because if the temperature exceeds 0°C, the micropores will be blocked after the organic polymer is removed, resulting in poor porosity.

Since the state of the micropores can be changed depending on the heating conditions of the dry gel and the amount and type of organic polymer, it is extremely easy to control and has excellent reproducibility. In particular, the diameter and number of pores can be easily controlled to be approximately constant by changing the amount of organic polymer added. Therefore, the reproducibility of the specific surface area of the pores can be greatly improved and improved. Therefore, claim 3
According to the method described in , hole radius: 10 can be reliably and easily
Å or less, and the reproducibility of the specific surface area of the pores can be improved.

[0022] As the organic polymer, for example, polypropylene glycol such as polyethylene glycol, polyacrylic acid, polyvinylpyrrolidone, polyvinyl alcohol, etc. may be used, and they can be uniformly mixed into a solution containing an organometallic compound and can be removed by heating. Various other materials can be used as long as they are easy to use, and there are no limitations.

[0023]

[Example] (Example 1) Silicon ethoxide: 25 gr
, 85% phosphoric acid: 1gr, ethanol: 20gr, water:
After stirring and mixing a solution containing 20 gr at 25° C. for 1 hour, a zirconia sphere having a diameter of 1 mm was immersed in this mixed solution. Next, after filtering this, the zirconia spheres to which the mixed solution had adhered were air-dried on a mesh to gel the mixed solution, thereby obtaining zirconia spheres covered with a dry gel. Next, this is heated at 500°C to turn the dry gel into porous vitrification, thereby producing a porous glass-coated inorganic body having a zirconia sphere as an inorganic support and a porous silica glass coating layer on its surface. I got it.

[0024] This porous glass-coated inorganic body had excellent moisture adsorption function and pressure loss resistance, and was also excellent in corrosion resistance, abrasion resistance, and heat resistance.

(Example 2) Silicon ethoxide: 10g
r, zirconium propoxide: 2gr, ethanol:
After stirring and mixing a solution containing 20gr of water and 0.1gr of water at 25°C for 1 hour, an alumina sphere having a diameter of 1.2mm was immersed in the solution. Next, it was filtered, air-dried, and heated in the same manner as in Example 1 to obtain a porous glass-coated inorganic body having a porous silica-zirconia glass coating layer on the surface of an alumina sphere (inorganic support). . However, the above heating temperature was 600°C. The pore size of the glass coating layer is 1
．． It was 3 nm.

The above-mentioned porous glass-coated inorganic body has particularly excellent crushing strength, and is entirely made of porous silica-zirconia glass without having an inorganic support.
The crushing strength was one order of magnitude higher than that of 2 mm 2 particles, and therefore it was possible to have extremely excellent contact efficiency and pressure loss resistance at the same time. In addition, when the above porous glass-coated inorganic material was packed in a Pyrex column and the n-butane and i-butane isomers were separated, it was found that the separation performance was good and it could be suitably used for such isomer separation. confirmed.

[0027]

Effects of the Invention The present invention has the structure and functions as described above, and the porous glass-coated inorganic body according to the present invention is similar to the porous glass obtained by the conventional sol-gel method. In addition to having excellent corrosion resistance, abrasion resistance, and heat resistance, it has higher strength than porous glass obtained by conventional sol-gel methods, and can also have excellent contact efficiency and pressure loss resistance. Therefore, the porous glass-coated inorganic body according to the present invention can be suitably used in industrial processes under harsh conditions, and has the advantage of being able to exhibit physicochemical functions such as adsorption functions over a long period of time in such processes. It is something that plays.

[0028] When the pore radius of the glass coating layer in the porous glass-coated inorganic body is set to 10 Å or less, the physicochemical function can be extremely improved, and the above-mentioned effects can be exhibited to a higher level. According to the method for producing a porous glass-coated inorganic body according to the present invention, the pore radius of the porous glass coating layer can be reliably and easily reduced to 10 Å or less, and the reproducibility of the specific surface area of the pores can be improved. Therefore, it is possible to reliably obtain a porous glass-coated inorganic body that can exhibit the above-mentioned effects to a higher level.

Claims (3)

[Claims] 1. A porous glass-coated inorganic body comprising an inorganic support and a porous glass coating layer formed by applying an organic metal compound-containing solution to the surface of the support and firing the coated layer. 2. The porous glass-coated inorganic body according to claim 1, wherein the pore radius of the porous glass coating layer is 10 Å or less. 3. A mixture containing an organometallic compound-containing solution and an organic polymer is applied to the surface of an inorganic support, dried and gelled, and then heated at a temperature of 500 to 800°C to vitrify and remove the organic polymer. 1. A method for producing a porous glass-coated inorganic body, which comprises forming a porous glass coating layer by removing an organic polymer in a dried gel.