JPH0648858A - Production of inorganic laminar porous body - Google Patents

Abstract

PURPOSE:To synthesize a sol in a large spherical shape and to obtain sufficient function of inorg. pillars by using metal alkoxide pillars treated with a basic catalyst in the production process to insert pillars among layers of swellable laminar compd. in a swollen state and to dry. CONSTITUTION:An inorg. laminar porous body is produced by inserting inorg. pillars 3 among layers of sweallable laminar compd. 1 in a swollen state and then drying. In this process, at least a part of inorg. pillars 3 is a metal alkoxide treated with a basic catalyst. Thereby, the sol to be inserted can be synthesized in a large and nearly spherical shape, which can be condensed into an extremely small size by drying. Therefore, the obtd. inorg. laminar porous body has a large void 2 and interlayer functions and functions of pillars can be sufficiently obtd.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing an inorganic layered porous body (or an inorganic porous body).

[0002]

2. Description of the Related Art Conventionally, as an inorganic layered compound having voids, that is, as an inorganic layered porous body, there is an intercalation substance in which a different substance such as a hydroxide is inserted and reacted between layers of a swellable layered compound (for example, a special layer is used). (See Japanese Laid-Open Patent Publication No. 54-5884 and Japanese Laid-Open Patent Publication No. 54-16386).

[0003]

However, the above-mentioned inorganic layered porous body is such that the size and shape of the sol to be inserted and the condensation in the drying process cause the interlayers to be small, and the functions of the different substances that are the interlayers and the pillars can be sufficiently brought out. I can't. According to the research conducted by the inventors, the conventional intercalation substance is, for example, as shown in FIG. 2, an inorganic pillar material 13 having a lateral width extremely wider than an interval between layers is used as an interlayer of the swellable layered compound 1. It was found that the void 12 was small because it was inserted into the.

An object of the present invention is to provide a method for producing an inorganic layered porous body in which the functions of interlayers and pillars are easily exhibited by synthesizing the sol to be inserted in a large and nearly spherical shape. The present invention also produces an inorganic layered porous body in which the sol to be inserted is synthesized in a large and nearly spherical shape, and the condensation in the drying process is extremely reduced to sufficiently bring out the functions of the interlayer and the pillar. The challenge is to provide a method.

[0005]

In order to solve the above-mentioned problems, the present invention provides a method for producing an inorganic layered porous body which comprises inserting an inorganic pillar between layers of a swelling layered compound in a swollen state and drying the layer. There is provided a method for producing an inorganic layered porous body, wherein at least a part of the inorganic pillar is a metal alkoxide treated with a basic catalyst.

In the present invention, as the above-mentioned inorganic pillar, a metal alkoxide treated with a basic catalyst is used.
It can be used with a cationic inorganic compound and / or a metal alkoxide treated with an acid catalyst. According to the present invention, as shown in FIG. 1, the swellable layered compound 1
What is treated with a basic catalyst with a metal alkoxide (hereinafter, may be referred to as a "treated product") is inserted between the layers and dried, and the treated product is an inorganic pillar material 3 which is a spherical polymer pillar. The width is smaller than that of the conventional inorganic pillar material 13. Therefore, the void 2 is larger than that shown in FIG.

In the present invention, the above-mentioned drying is preferably performed by supercritical drying (drying performed in a supercritical state) or carbon dioxide in a liquid state to obtain an inorganic layered porous body. Specific examples of the swellable inorganic layered compound used in the present invention include the following. Na
Montmorillonite, Ca montmorillonite, acid clay,
Synthetic smectite, Na teniolite, Li teniolite, Na hectorite, Li hectorite, synthetic mica, etc., but only if it is a swellable layered compound,
It is not limited to these. Metal alkoxide
For example, Si (OR) ₄ , Ti (OR) ₄ , Zr (O
R) ₄ , Ge (OR) ₄ , Al (OR) ₃ , B (OR) ₃ , PO
It is at least one of (OR) ₃ and Ga (OR) ₃ , but is not limited to these. Where R
Is, for example, an alkyl group. As the cationic inorganic compound, titanium compounds, zirconium compounds, hafnium compounds, aluminum compounds, gallium compounds, nickel compounds, iron compounds, cobalt compounds, copper compounds, zinc compounds, etc. However, the present invention is not limited to these.

Next, the method for producing the inorganic layered porous material of the present invention will be described more specifically step by step. First, the swelling layered compound (or the swelling inorganic layered compound) as the main material is dispersed in a solvent such as water. At this time, swelling of the swellable layered compound occurs. As the solvent to be used, for example, water, ethanol, methanol, DMF (dimethylformamide), DMSO (dimethylsulfoxide), acetone or the like may be used alone or in combination of two or more.

Then, a pillar compound to be inserted between the layers is synthesized. Dilute the metal alkoxide with alcohol etc.,
The basic catalyst is then added. As a basic catalyst,
Examples thereof include, but are not limited to, aqueous ammonia, piperidine, and aqueous sodium hydroxide solution. A basic catalyst was added, and the fully reacted solution was left as is,
Alternatively, after adding an acid catalyst, the acid catalyst is added to the swelling layered compound dispersed in the solvent to cause an intercalation reaction. The reaction temperature and time are not particularly limited, but one example is preferably 60 ° C. and 1.5 hours.

The intercalated inorganic layered compound thus obtained is solid-liquid separated and dried. The drying method may be ordinary heat drying or freeze drying, and preferably supercritical drying or liquid carbonic acid extraction drying can be used. However, the term "supercritical drying" as used herein also includes drying just at the critical point. When drying in a supercritical state, for example, the following is performed. There is a method of directly heating and pressurizing a solvent held in the inorganic stratiform compound such as water contained between layers to reach a state at a critical point or higher to remove the solvent and dry it. However, in this case, if a solvent having an extremely high critical point (critical temperature of water: 374.2 ° C., critical pressure: 217.6 atm) is used, such as water, a special autoclave or the like must be used. To avoid this, for example, after replacing the solvent contained in the inorganic layered compound with a solvent having a low critical point, supercritical drying is performed. For example, when the inorganic layered compound contains water, it is replaced with ethanol and then supercritically dried under supercritical conditions of ethanol, or after replacing water with ethanol, carbon dioxide is further added, and then gradually. The supercritical state may be realized by heating and pressurizing to a temperature and pressure above the critical point of the binary system of carbon dioxide and ethanol while replacing ethanol with carbon dioxide. After the ethanol has been extracted and removed, if the temperature is returned to normal temperature and normal pressure, the drying process is completed. When replacing ethanol with carbon dioxide, carbon dioxide at a critical point or higher can be fed into the system for replacement. The fluid that can be used as the solvent is not limited to the above. There are various substances that can be made into a supercritical fluid within a practical range, and examples thereof include ethanol, methanol, carbon dioxide, dichlorodifluoromethane, and ethylene. For reference, the critical conditions for major fluids are shown in Table 1.

[0011]

[Table 1]

When extracting and drying with liquid carbonic acid, the same method is used in terms of steps. For example, liquid carbon dioxide is brought into contact with the material to be dried, and the solvent contained in the material to be dried is extracted and dried. However, as shown in FIG. 3, the drying can be performed in a state where the temperature and pressure are lower than the supercritical state. In FIG. 3, Q is a gas region of carbon dioxide, a region R having a diagonal line rising to the right (including a boiling line, a triple point, and a melting line) is a liquid region of carbon dioxide, and a region S having a diagonal line rising to the left is It is the supercritical state region of carbon dioxide (including the critical point CP).

In this way, the obtained inorganic layered porous material has a larger interlayer and pores than the conventional porous material even when hot-air dried or freeze-dried, so that the interlayer and pillar functions can be sufficiently exhibited. It has a structure of. In the present invention, when supercritical drying and liquid carbonic acid extraction drying are performed,
Furthermore, it has a structure that makes it easy to utilize its functionality.

[0014]

In the present invention, the spherical pillars are inserted between the layers of the swelling layered compound, so that the layers are large and the volume of pores is large. In addition, by performing drying by supercritical drying or liquid carbonic acid extraction drying, condensation in the drying process is reduced, and a porous body with large layers and large pores is obtained, and the functions of the layers and pillars are sufficiently An inorganic layered porous body is obtained in a form that can be exhibited.

[0015]

EXAMPLES Specific examples and comparative examples of the present invention will be shown below, but the present invention is not limited to the following examples. (Example 1) As a swellable layered compound, Na montmorillonite (Kunipia F manufactured by Kunimine Industries Co., Ltd.) was used and swollen with water. Next, metal alkoxide tetraisopropyl titanate (Nacalai Tesque reagent)
Ethanol and 2M aqueous ammonia solution were added to the mixture to carry out hydrolysis and polymerization reaction. After the reaction, a 2M aqueous hydrochloric acid solution was further added, and then Na montmorillonite previously dispersed in water was added to carry out an intercalation reaction. Na
The mixing ratio of montmorillonite and titania was 1: 0.6 by weight. Regarding the reaction temperature, the intercalation reaction was carried out at 60 ° C., and the rest was carried out at room temperature. The liquid after the reaction was subjected to solid-liquid separation, and then repeatedly washed with ethanol. After washing with ethanol, while adding carbon dioxide (CO ₂ ) having a relatively low critical point,
Supercritical drying was performed at 80 atm for 8 hours. After drying
It was baked at 400 ° C. to obtain an inorganic layered porous body.

(Example 2) An inorganic layered porous body was obtained in the same manner as in Example 1 except that the drying was carried out by hot air drying (80 ° C, 5 hours). (Example 3) An inorganic layered porous body was obtained in the same manner as in Example 1 except that tetraisopropyl zirconate (a reagent manufactured by Nacalai Tesque) was used in place of tetraisopropyl titanate.

Example 4 N was used as the swellable layered compound.
a Montmorillonite (Kunipia F manufactured by Kunimine Industries Co., Ltd.) was used and swollen with water. Next, 2M ammonia water and ethanol were added to tetraethyl orthosilicate (reagent manufactured by Nacalai Tesque) to carry out hydrolysis and polymerization reaction. Then add 2M aqueous hydrochloric acid to this solution,
The pH was lowered to around 1. Then, a 2M aqueous hydrochloric acid solution was added to tetraisopropyl titanate, which was hydrolyzed and peptized to obtain a silica-titania sol. This silica-titania sol solution was added to the Na-montmorillonite aqueous solution previously dispersed in water to carry out an intercalation reaction. Na montmorillonite,
The ratio of each of silica and titania is 1: by weight.
It was 0.6: 0.06. Regarding the reaction temperature, hydrolysis of tetraethyl orthosilicate, polymerization reaction and intercalation reaction were carried out at 60 ° C., and other conditions were carried out at room temperature. After the reaction, this solution was subjected to solid-liquid separation, washed with ethanol several times, and then subjected to supercritical drying at 40 ° C. and 80 atm for 8 hours while adding carbon dioxide having a relatively low critical point. . After drying, it was baked at 400 ° C. to obtain an inorganic layered porous body.

(Example 5) Inorganic layered porous layer was prepared in the same manner as in Example 4 except that liquid carbonic acid extraction drying (extraction at 5 ° C and 60 atm) was used instead of supercritical drying. Got the body (Example 6) Na montmorillonite (Kunipia F manufactured by Kunimine Industries Co., Ltd.) was used as a swellable layered compound, and this was swollen with water. Next, 2M ammonia water and ethanol were added to tetraethyl orthosilicate (reagent manufactured by Nacalai Tesque) to carry out hydrolysis and polymerization reaction. Then,
A 2M aqueous hydrochloric acid solution was added to this solution to lower the pH to about 1. Then, a 2M aqueous hydrochloric acid solution was added to titanium tetrachloride, and a solution obtained by hydrolysis and peptization was added to synthesize silica-titania sol. This silica-titania sol solution was added to the Na-montmorillonite aqueous solution previously dispersed in water to carry out an intercalation reaction.
The weight ratio of Na-montmorillonite, silica, and titania was 1: 0.6: 0.06. Regarding the reaction temperature, hydrolysis of tetraethyl orthosilicate, polymerization reaction and intercalation reaction were carried out at 60 ° C., and other conditions were carried out at room temperature. After the reaction, this solution was subjected to solid-liquid separation, washed with ethanol several times, and then subjected to supercritical drying at 40 ° C. and 80 atm for 8 hours while adding carbon dioxide having a relatively low critical point. . After drying, it was baked at 400 ° C. to obtain an inorganic layered porous body.

Comparative Example 1 An inorganic layered porous body was obtained in the same manner as in Example 1 except that the basic catalyst was not used. The specific surface area and pore volume of the inorganic layered porous bodies of Examples 1 to 6 and Comparative Example 1 were measured. The specific surface area and pore volume were measured by the nitrogen adsorption method. The measurement results are shown in Table 2.

[0020]

[Table 2]

As can be seen from Table 2, the inorganic layered porous bodies of Examples 1 to 6 have a larger specific surface area and a smaller pore volume than those of Comparative Example 1 and have a small condensation upon drying, and have a high functionality. It has a structure that is easy to demonstrate.

[0022]

According to the method for producing an inorganic layered porous body of the present invention, a sol to be inserted between layers is synthesized in a nearly spherical shape to obtain a porous body having a large interlayer spacing and a large pore volume. The obtained porous body has a structure in which the functions of the interlayer and the pillar are easily exhibited. Further, by using the supercritical drying and the liquid carbonic acid extraction drying method, it is possible to reduce the condensation at the time of drying and obtain an inorganic layered porous body having a more ideal structure.

[Brief description of drawings]

FIG. 1 is a schematic explanatory view of an inorganic layered porous body obtained by the production method of the present invention.

FIG. 2 is a schematic explanatory view of an inorganic layered porous body obtained by the method shown in Comparative Example.

FIG. 3 is a state diagram of CO ₂ used in the manufacturing method of the present invention.

[Explanation of symbols]

 1 Swellable Layered Compound 2 Void 3 Inorganic Pillar Material

Claims (4)

[Claims] 1. In a method for producing an inorganic layered porous body, wherein an inorganic pillar is inserted between layers of a swellable layered compound in a swollen state and drying is performed, at least a part of the inorganic pillar is
A method for producing an inorganic layered porous body, which comprises treating a metal alkoxide with a basic catalyst. 2. The production of an inorganic layered porous body according to claim 1, wherein a metal alkoxide treated with a basic catalyst is used as the inorganic pillar together with a metal alkoxide treated with a cationic inorganic compound and / or an acid catalyst. Method. 3. The method for producing an inorganic layered porous body according to claim 1, wherein the drying is performed in a supercritical state or with liquid carbonic acid. 4. The metal alkoxide is Si (OR) ₄ , T
i (OR) ₄ , Zr (OR) ₄ , Ge (OR) ₄ , Al (O
The method for producing an inorganic layered porous body according to any one of claims 1 to 3, wherein at least one of R) ₃ , B (OR) ₃ , PO (OR) ₃ and Ga (OR) ₃ is used.