JP2002119855A - Method for manufacturing porous molding - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing a porous molding by which the molding of highly densified porous particles can be repeatedly obtained with good reproducibility while maintaining adsorbing characteristic of the porous particles at high level. SOLUTION: The method for manufacturing the porous molding is distinguished by containing a first process in which an aggregate of porous particles having plural fine pores is blended with an additive that is nonreactive with the porous particles and can enter inside the fine pores, thereby the additive is introduced inside the fine pores and into gaps between porous particles to obtain a mixture composed of the porous particles and the additive, a second process in which the molding is obtained by pressurizing the mixture and a third process in which the additive is removed from the molding.

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 a porous molded article, and more particularly, it is possible to sufficiently reduce collapse of pores of porous particles and gaps between porous particles due to pressure during molding. The present invention relates to a method for producing a porous molded article.

[0002]

2. Description of the Related Art Since the discovery of a silica-based porous material having a so-called mesopore having a diameter of about 1.5 to 50 nm arranged very regularly (hereinafter referred to as silica mesoporous material) (for example, CT Kresge et al. ., Nature, vol.359, p710, 19
92, S. Inagaki et al., J. Chem. Soc., Chem. Commu
n., 680, 1993, etc.), and its use has been actively developed. For example, silica mesoporous materials are used for adsorbents and catalysts utilizing their excellent adsorption characteristics,
Since the mesoporous silica material is usually provided as a powdery substance, when it is applied to such an application, it is general to increase the density by compacting.

[0003] Powder compaction of mesoporous silica is, for example,
It is disclosed in Japanese Patent Application Laid-Open No. Hei 9-178292. This publication describes that the mesoporous silica powder is compacted as it is and used as an adsorbent for an adsorption heat pump.

[0004]

However, when a mesoporous silica material is molded according to the method disclosed in the above-mentioned publication, a high density is achieved, but when the molded material is used as an adsorbent, a catalyst, or the like. In some cases, the adsorption performance and the catalyst performance were inferior to those of the mesoporous silica body before molding. In addition, there is a problem that the characteristics of the molded body vary widely and the reproducibility of the performance is low.

The present invention has been made in view of the above-mentioned problems of the prior art, and it is intended to repeatedly form a densified porous particle molded article while maintaining the adsorption characteristics of the porous particle at a high level. It is an object of the present invention to provide a method for producing a porous molded body that can be obtained with good reproducibility.

[0006]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies in order to achieve the above object, and as a result, the decrease in the adsorbing performance and the catalytic performance after molding in the above-mentioned prior art is due to the fact that the powdered powder is a porous material. It has been found that the pores of the particles and the gaps between the porous particles are crushed to reduce the specific surface area and the volume of the pores, or that the diffusion path of the adsorbed substance or the like is blocked.

As a result of further research based on this finding, it has been found that, after a specific additive is added to the porous particles, pressure is applied, and the additive is removed after the pressurization. Of the pores and the gaps between the porous particles can be sufficiently prevented, and it is possible to obtain a highly densified porous particle molded body with high reproducibility while maintaining the adsorption characteristics of the porous particles at a high level. And completed the present invention.

That is, the method for producing a porous molded article according to the present invention comprises: (1) an aggregate of porous particles having a plurality of pores; By mixing with an additive that can penetrate, the additive is introduced into the inside of the pores and the gap between the porous particles to obtain a first mixture of the porous particles and the additive. And (3) a second step of removing the additive from the molded article by pressing the mixture to obtain a molded article, and (3) a third step of removing the additive from the molded article.

In the present invention, it is preferable that, in the first step, 2 to 70 parts by weight of the additive is mixed with 100 parts by weight of the aggregate of the porous particles. It is preferable that the surface is hydrophilic porous particles and the additive is a polar additive.

In the present invention, the porous particles are mesoporous silica having a plurality of mesopores,
Further, it is preferable that the additive is at least one compound selected from the group consisting of a liquid having polarity and an ammonium salt represented by the following general formula (1).

Embedded image [Wherein, R ¹ , R ² and R ³ may be the same or different, and each may be a linear or branched monovalent organic group having 1 to 4 carbon atoms;
R ⁴ is a linear or branched monovalent organic group having 5 or more carbon atoms;
X represents a halogen atom or a hydroxyl group, respectively. ]

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION The method for producing a porous molded article according to the present invention comprises: (1) an aggregate of porous particles having a plurality of pores;
By mixing the porous particles with an additive that is non-reactive and can penetrate into the pores, the additive is introduced into the pores and the gaps between the porous particles. A first step of obtaining a mixture of porous particles and the additive, (2) a second step of pressing the mixture to obtain a molded body, and (3) removing the additive from the molded body And a third step.

First, the first step in the present invention will be described. The porous particles used in the first step may be a particulate substance in which a plurality of pores are formed by partitioning into pore walls, and the particle shape, particle size, pore shape, pore diameter, The composition and the like are not particularly limited. Examples of the shape of the porous particles include a spherical shape, a spindle shape, a polyhedral shape, and a fibrous shape, and a mixture of a plurality of shapes may be used. The average particle size of the porous particles is not particularly limited as long as a molded product can be obtained by applying pressure.

The pores formed by partitioning the pore walls may be independent pores in which the pores are not connected or continuous pores in which at least some of the pores are connected. . Examples of the shape of the pore include a spherical shape, a polyhedral shape, a cylindrical shape, a polygonal column shape, and the like, and a mixture of a plurality of shapes may be used. Although the pore diameter is not particularly limited, when the pore diameter is mesosize (1.5 to 50 nm),
The central pore diameter measured by the nitrogen adsorption method is 1.5 to
Preferably it is 5 nm. Here, the central pore diameter is defined as the pore diameter at the maximum peak of the pore diameter distribution curve of the porous particles. In the nitrogen adsorption method, the porous pore cooled to the liquid nitrogen temperature (-196 ° C) is used. From the adsorption isotherm obtained by adsorbing nitrogen gas to the particles at various pressures, a pore diameter distribution curve is obtained using the BJH method or the like. In the first step, porous particles containing organic components such as a surfactant used during the synthesis of the porous particles are used inside the pores having the above-mentioned shape, and mixed with the additive. I do.

The porous particles used in the first step preferably have a specific surface area and a pore volume of a certain amount or more from the viewpoint of adsorption characteristics when used as an adsorbent. That is, the specific surface area of the porous particles is 200 m ² / g when the organic component inside the pores is removed.
Or more, and more preferably 400 m ² / g or more. The pore volume is 0.1 mL /
g or more, more preferably 0.3 mL / g or more. The specific surface area and pore volume are determined by the nitrogen adsorption method described above. E. FIG. T. Apply the single point method.

The pores in the present invention may be randomly distributed in the porous particles or may be arranged with a certain regularity. The regularity of the arrangement of the pores can be examined, for example, by powder X-ray diffraction of the porous particles. That is, when a clear peak appears in the X-ray diffraction pattern, it can be determined that the pore arrangement structure is regular, and when a clear pattern does not appear, it is determined that the pores are randomly distributed. can do. As an embodiment of the regular pore array structure, a two-dimensional hexagonal (S. Inagaki, et al., J. Chem. Soc., Che
m. Commun., 680, 1993), three-dimensional hexagonal (see Q. Huo et al., Science, 268, 1324, 1995),
Cubic (JC Vartuli et al., Chem. Mater.,
6, 2317, 1994; Q. Huo et al., Nature, 368, 317, 19
94).

The component constituting the porous particles in the present invention is not particularly limited, but is preferably a component having a hydrophilic surface. Here, the surface means the surface of the porous particle including the surface of the pore wall inside the pore of the porous particle. In porous particles, since the surface area of the pore wall inside the pore is very large, it is preferable that the surface of the pore wall inside the pore is hydrophilic. By using a porous particle having a hydrophilic surface as an additive, the additive can be efficiently introduced into the pores and into the gaps between the porous particles.

In the present invention, the component constituting the porous particles is preferably silica. Even though silica is a silicon oxide, aluminum (Al), titanium (Ti), magnesium (Mg), zirconium (Z
r), gallium (Ga), beryllium (Be), yttrium (Y), lanthanum (La), tin (Sn), lead (Pb), vanadium (V), boron (B), etc. It may be. When the porous particles are made of the above silicon oxide or silicon double oxide, the surface becomes hydrophilic.

In the present invention, it is particularly preferable to use a mesoporous silica material having a plurality of mesopores as the porous particles. Here, the mesoporous silica material has a diameter of 1.
It means porous particles containing silica having pores (mesopores) of 5 to 50 nm as components, and the definition of silica is the same as above.

As such a mesoporous silica material,
(A) in an aqueous solution a surfactant has been dissolved, kanemite _{(NaHSi 2 O 5 · 3H 2} O) silica mesoporous material layered silicate by mixing the synthesis of such is available (T.
Yanagisawa et al., Bull. Chem. Soc. Jpn, 63, 988-
992, 1990, JP-A-8-67578, etc.). Alternatively, (b) a silica mesoporous material synthesized by mixing a non-layered silicate such as water glass, tetraorthosilicate, or amorphous silica in an aqueous solution in which a surfactant is dissolved can be used (CT Kresge). et al., Nature, 359,
710, 1992, and JP-A-8-67578).

In the present invention, it is preferable to use mesoporous silica synthesized by the method (a). In this case, as the layered silicate, in addition to kanemite, sodium disilicate crystals (α, β, γ, δ)
-Na ₂ Si ₂ O _5), makatite _{(Na 2 Si 4 O 9 ·} 5H
₂ O), Aia light _{(Na 2 Si 8 O 17 ·} xH 2 O), magadiite _{(Na 2 Si 14 O 17 ·} xH 2 O), using a kenyaite _{(Na 2 Si 20 O 41 ·} xH 2 O) , etc. You can also. Further, clay minerals such as sepiolite, montmorillonite, vermiculite, mica, kaolinite, smectite and the like, which are treated with an acidic aqueous solution to remove elements other than silica, can also be used as the layered silicate.

As the surfactant used in the above method (a) or (b), any of a cationic surfactant, an anionic surfactant and a nonionic surfactant can be applied. It is preferable to use an ammonium salt represented by the following general formula (1).

Embedded image [Wherein, R ¹ , R ² and R ³ may be the same or different, and each may be a linear or branched monovalent organic group having 1 to 4 carbon atoms;
R ⁴ is a linear or branched monovalent organic group having 5 or more carbon atoms;
X represents a halogen atom or a hydroxyl group, respectively. As the alkylammonium halide, an alkyltrimethylammonium halide in which R ¹ , R ² and R ³ are all methyl groups and R ⁴ is an alkyl group is particularly preferred.

In the first step, the aggregate of the porous particles described above and the additive are mixed. The additive is not particularly limited as long as it is non-reactive with the porous particles and at least a part of the additives can penetrate into the pores or the spaces between the particles in the porous particles. Here, that the additive is non-reactive means that the additive does not react with the porous particles (does not generate a chemical bond) under the condition that the additive and the porous particles are mixed. Inquiries by intermolecular forces such as hydrogen bonds and van der Waals forces are not included in the chemical bonds mentioned here. Also, that the additive can enter the inside of the pores of the porous particles,
It means that the additive can be taken into the pores due to adsorption, capillary action, and the like. Therefore, as long as the additive can penetrate into the pores, the additive may be solid or liquid, and the molecular size may be larger than the pore diameter.

The additive in the present invention is introduced into the inside of the pores of the porous particles and the gap between the porous particles by mixing with the porous particles, and a mixture of the porous particles and the additive is obtained. By introducing the additive into the inside of the pores of the porous particles and the gaps between the porous particles, even when the mixture is pressurized, the pores and the gaps between the porous particles are less likely to be crushed. In addition, it is possible to obtain a molded article of the porous particles having a high density while maintaining the adsorption characteristics of the porous particles at a high level.

In the present invention, it is preferable to use a polar additive for the porous particles having a hydrophilic surface. Since the polar additive has a high affinity for the hydrophilic surface, the additive tends to be easily introduced into the inside of the pores of the porous particles and the gap between the porous particles. When the porous particles are the above-mentioned mesoporous silica material, the additive is at least one selected from the group consisting of a polar liquid and an ammonium salt represented by the following general formula (1).
Preferably, it is one compound.

Embedded image [Wherein, R ¹ , R ² and R ³ may be the same or different, and each may be a linear or branched monovalent organic group having 1 to 4 carbon atoms;
R ⁴ is a linear or branched monovalent organic group having 5 or more carbon atoms;
X represents a halogen atom or a hydroxyl group, respectively. ]

Examples of the polar liquid include water and alcohol. The alcohol as an additive may be a monohydric alcohol or a polyhydric alcohol, and the molecular structure is not particularly limited, but in the present invention, an alcohol having 1 to 20 carbon atoms is preferable, and an alcohol having 1 to 10 carbon atoms is more preferable. . Such alcohols include methanol, ethanol, propanol, butanol, ethylene glycol, propylene glycol, glycerol,
Trimethylolpropane, hexanol, heptanol, octanol and the like.

When the additive is a compound represented by the above general formula (1), R ¹ , R ² and R ³ may be the same or different, and may be linear or branched having 1 to 4 carbon atoms. It is an alkyl group, and R ⁴ is preferably a linear or branched alkyl group having 5 or more carbon atoms. R ¹ , R ² , R
Preferably at least one of the ^three is a methyl group, and more preferably all of R ^1, R ^2, R ³ is a methyl group. Further, R ⁴ in the general formula (1) is preferably a linear or branched alkyl group having 5 to 30 carbon atoms, and more preferably the alkyl group has an even number of carbon atoms.

Accordingly, the additive represented by the general formula (1) is an alkyltrimethylammonium halide in which all of R ¹ , R ² and R ³ are methyl groups and R ⁴ is an alkyl group. The alkyltrimethylammonium halide is preferably octyltrimethylammonium halide, decyltrimethylammonium halide, dodecyltrimethylammonium halide, tetradecyltrimethylammonium halide, hexadecylammonium halide, or octadecylammonium halide. The halide in these alkyltrimethylammonium halides is preferably chloride or bromide.

The alkylammonium halide used as an additive has the same general formula as the surfactant used when synthesizing the porous particles (silica mesoporous material) by the method (a) or (b). expressed. That is, when the mesoporous silica body synthesized according to the above method (a) or (b) is molded by pressing, a surfactant that can be used in the method (a) or (b) is used as an additive. Can be used. In this case, the surfactant and the additive may be alkylammonium halides represented by the general formula (1), and do not have to have exactly the same chemical structure.

According to the above synthesis methods (a) and (b), the surfactant functions as a template for forming pores, and thus the resulting mesoporous silica material incorporates the surfactant into the pores. It will be. Since the content of the incorporated surfactant is not always the same even when the synthesis conditions are the same, when molding is performed by pressing under the same condition after the synthesis, if the content of the surfactant is large, the content is fine. When the crushing of the pores and the like is small and the content of the surfactant is small, the crushing of the pores and the like increases, and a molded article having uniform performance as a whole cannot be obtained. In addition, due to the influence of the humidity of the storage location of the mesoporous silica material after synthesis, different amounts of water penetrate into the inside of the pores, so that the surfactant content in the pores could be kept constant. Even in this case, the amount of the substance in the pores changes over time.

However, in the present invention, even when porous particles having a variable surfactant content are used, a predetermined amount of additive always penetrates into the pores. The number of collapsed pores is less likely to vary between porous particles, and the total number of collapsed pores is also reduced. This is the same even when the additive is added after removing the surfactant or the like in the pores by baking or the like.

In the first step of the present invention, it is preferable to mix 2 to 70 parts by weight of the additive with respect to 100 parts by weight of the porous particles. The amount of the additive based on 100 parts by weight of the porous particles is more preferably from 5 to 70 parts by weight, and even more preferably from 5 to 50 parts by weight. When the amount of the additive is less than 2 parts by weight, the amount of the additive introduced into the inside of the pores of the porous particles and the gap between the porous particles tends to be insufficient, and the pores and the porous The gap between the particles may be crushed. When the amount of the additive is 70
When the amount is more than the weight part, the solid additive is secondary-agglomerated to form a large mass, which may be sandwiched between the porous particles, and it tends to be difficult to obtain a uniform molded product. .

In the first step, the method of mixing the above-described aggregate of porous particles and the additive is as follows.
A method of shaking (vibrating) or stirring for about 30 minutes is exemplified. The temperature at the time of shaking or stirring is preferably lower than the melting point or boiling point of the additive, more preferably near room temperature.

Next, the second step in the present invention will be described. In the second step, the mixture of the porous particles and the additive obtained in the first step is pressurized to obtain a molded body. In this case, as a molding method, the mixture is introduced into a container, and the pressure is 200 to 10000 k by a press such as a roll press, a rubber press, an isostatic press, and tableting.
g / cm ² (preferably, 500 to 4000 kg / c)
m ² ). The temperature at the time of pressurization can be set at 0 to 100 ° C. (preferably, a temperature lower than the melting point or the boiling point of the additive), and the pressurization time can be determined by the type of the porous particles, the size of the pressurizer, and the like. is there. In addition, the compact obtained in the second step may be appropriately pulverized before moving to the third step.

Next, the third step in the present invention will be described. In the third step, the additive is removed from the compact obtained in the second step. Examples of the method for removing the additive include a method of extracting the additive with a good solvent, a method of heating and melting the additive, and a method of firing the additive. When the additive has polarity, extraction or calcination with a polar solvent is preferred.

When the alkylammonium halide represented by the general formula (1) is used as the additive, it is preferable to remove the additive by a calcination method, an extraction method using an organic solvent, an ion exchange method, or the like. In the firing method, the molded body is heated at 300 to 1000 ° C, preferably 400 to 700 ° C.
Heat with. The heating time may be about 30 minutes, but it is preferable to heat for 1 hour or more to completely remove the additive. Although calcination can be performed in the air, a large amount of combustion gas is generated, so that an inert gas such as nitrogen may be introduced.

When applying the extraction method using an organic solvent,
The porous body is immersed in a good solvent of the used alkyl ammonium halide for extraction. In the ion exchange method, the compact is immersed in an acidic solution (such as ethanol containing a small amount of hydrochloric acid) and stirred while heating at, for example, room temperature to 70 ° C. Thereby, the alkylammonium halide present in the pores of the compact is ion-exchanged with hydrogen ions and extracted.

The packing density of the porous molded article obtained in the third step can be determined from the values of the volume and weight of the porous molded article.
E. FIG. T. It can be determined by the one-point method. The pore volume can be calculated from the nitrogen adsorption isotherm. In the present invention, the packing density of the finally obtained porous molded body is 0.1%.
Preferably, the specific surface area is 2 g / mL or more.
It is preferably at least 00 m ² / g. Further, the pore volume is preferably 0.3 mL / g or more.

[0038]

Hereinafter, preferred embodiments of the present invention will be described in more detail, but the present invention is not limited to these embodiments.

[Synthesis of Mesoporous Silica] (Synthesis Example 1) 25.2 g of octyltrimethylammonium bromide (0.1 M) was added to 1000 mL of ion-exchanged water.
And 10 g of sodium disilicate was added thereto, and the temperature was raised to 70 ° C. After heating at 70 ° C. with stirring for 3 hours, 2N hydrochloric acid was added to adjust the pH of the sodium disilicate dispersion to 7.5. After further stirring for 3 hours, the mixture was allowed to cool to room temperature, and the product was separated by filtration. The obtained solid was dispersed in 1,000 mL of ion-exchanged water, washed, and filtered. The operation of washing and filtration was repeated three times, followed by drying in a dryer at 45 ° C. for 24 hours, and baking in air at 550 ° C. for 6 hours to remove organic substances in the pores to obtain a mesoporous silica material. As a result of X-ray diffraction, it was found that the obtained mesoporous silica material had a two-dimensional hexagonal pore array structure. The silica mesoporous material thus obtained was referred to below as FSM / 8-A
Call.

(Synthesis Examples 2 to 5) The weight of octyltrimethylammonium bromide was 3024 g, the capacity of ion exchange water was 120 L, and the weight of sodium disilicate was 1200.
g of Synthesis Example 1 except that g was used.
A total of four times mesoporous silica was synthesized on a double scale. As a result of X-ray diffraction, each of the mesoporous silica materials had a two-dimensional hexagonal pore array structure. The obtained mesoporous silica was subjected to FSM / 8-B, FSM / 8
-C, FSM / 8-D and FSM / 8-E.

(Synthesis Example 6) Mesoporous silica was prepared in the same manner as in Synthesis Example 1 except that 28.0 g of decyltrimethylammonium bromide was used instead of 25.2 g of octyltrimethylammonium bromide, and the weight of sodium disilicate was changed to 50 g. I got a body. As a result of X-ray diffraction, the product, mesoporous silica, had a two-dimensional hexagonal pore array structure. The resulting mesoporous silica material was
Called SM / 10.

(Synthesis Example 7) A mesoporous silica material was obtained in the same manner as in Synthesis Example 1 except that 30.8 g of dodecyltrimethylammonium bromide was used instead of 25.2 g of octyltrimethylammonium bromide. As a result of X-ray diffraction, the product, mesoporous silica, had a two-dimensional hexagonal pore array structure. The obtained mesoporous silica material is hereinafter referred to as FSM / 12.

Synthesis Example 8 A mesoporous silica material was obtained in the same manner as in Synthesis Example 1 except that 33.6 g of tetradecyltrimethylammonium bromide was used instead of 25.2 g of octyltrimethylammonium bromide. As a result of X-ray diffraction, the product, mesoporous silica, had a two-dimensional hexagonal pore array structure. The obtained mesoporous silica material is hereinafter referred to as FSM / 14.

(Synthesis Examples 9 to 11) In place of 25.2 g of octyltrimethylammonium bromide, 36.4 g
A mesoporous silica material was obtained in the same manner as in Synthesis Example 1 except that hexadecyltrimethylammonium bromide was used.
This synthesis was repeated three times in total. As a result of X-ray diffraction, all of the mesoporous silica products were found to have a two-dimensional hexagonal pore array structure. The obtained mesoporous silica was subjected to FSM / 16-A, FSM / 16-B, FS
Called M / 16-C.

[Ratio of Organic Component in Mesoporous Silica Before Firing] The ratio (% by weight) of the organic component in the mesoporous silica before firing in Synthesis Examples 1 to 11 was measured by the following method. That is, Rigaku Thermo
Using Plus TG8120, about 10 mg of the mesoporous silica body before calcination in Synthesis Examples 1 to 11 was heated at a rate of 10 ° C./min under a flow of nitrogen to perform thermogravimetry. In the thermogravimetry, the weight loss up to 150 ° C. was attributed to moisture, and the weight loss up to 600 ° C. was attributed to the organic components in the mesoporous silica material. The results are shown in Table 1 below.

[Proportion of Moisture in Mesoporous Silica Before Firing] In Synthesis Examples 2 to 6 and 11, the weight of the mesoporous silica before calcining dried for 24 hours with a drier at 45 ° C. was measured, and then 4 hours at 70 ° C. After vacuum drying, the weight was measured again. From this weight difference, the ratio (% by weight) of water in the mesoporous silica body before firing was calculated. The results are shown in Table 1 below.

[0047]

[Table 1]

Although the mesoporous silica bodies before calcination of Synthesis Examples 2 to 5 in Table 1 were synthesized under the same conditions, there was a maximum difference of 4% in the ratio of the organic component, and It was found that there was a difference of up to about 2%. In addition, it was found that although the mesoporous silica bodies before firing in Synthesis Examples 9 to 11 were synthesized under the same conditions, the ratio of the organic component had a difference of about 10% at the maximum.

[Characteristics of Mesoporous Silica Body After Firing] Table 2 shows properties of the mesoporous silica body obtained after firing obtained in Examples 1 to 11. In Table 2, the specific surface area (m ² /
g) and the pore volume (mL / g) are calculated by the nitrogen adsorption method described above.

[0050]

[Table 2]

[Production of Porous Molded Body] (Example 1) FSM / 8- before firing obtained in Synthesis Example 2
50 g of B (porous particles) was weighed into a thick vinyl chloride bag. 25 g of octyltrimethylammonium bromide (additive) was added into the bag, and the mixture was uniformly mixed by vibrating for 10 minutes or more until the lumps disappeared (the amount of the additive was 50 parts by weight based on 100 parts by weight of the porous particles). . This mixture was sealed in another bag made of vinyl chloride, and kept at a pressure of 200 kg / cm ² for 1 minute by a hydrostatic press. The obtained sample is crushed in a mortar and the particle size is 0.2 to 0.3 mm.
After baking in air at 550 ° C. for 6 hours, the additives were removed to obtain a porous molded body.

(Examples 2 to 4) The pressure of the hydrostatic press was set to 5
Except that the weight was set to 00, 1000, and 3000 kg / cm ² , the porous molded bodies of Examples 2, 3, and 4 were obtained in the same manner as in Example 1.

(Comparative Examples 1 to 4) Comparative Examples 1 to 3 were prepared in the same manner as in Examples 1, 2, 3, and 4 except that octyltrimethylammonium bromide (additive) was not used.
2, 3, and 4 porous molded articles were obtained.

[Evaluation of Porous Molded Article] The packing density (g / g) was measured by measuring the volume and weight of the porous molded articles obtained in Examples 1 to 4 and Comparative Examples 1 to 4 with a measuring cylinder and a weighing machine. mL). In addition, the specific surface area of these porous molded bodies was adjusted to B.I. by the adsorption of nitrogen gas under liquid nitrogen. E. FIG. T. Determined by the one-point method. Further, the water vapor adsorption isotherm of these porous molded bodies was measured using a water vapor adsorption device BELSORP18 manufactured by Bell Japan. Before the measurement of the water vapor adsorption isotherm, the porous molded body was subjected to ultrasonic treatment for 30 minutes and left as it was until the next day to sufficiently hydrate the surface. After filtration, the porous molded body was evacuated at 25 ° C. for 4 hours (10 ^−3). mmH
g) Pretreatment was performed.

Tables 3 and 4 below show the packing densities and specific surface areas of the porous compacts obtained in Examples 1 to 4 and Comparative Examples 1 to 4, respectively. FIG. 1 shows a third embodiment.
2 shows the water vapor adsorption isotherm of the porous molded article obtained in Comparative Example 1, and FIG. 2 shows the water vapor adsorption isotherm of the porous molded article obtained in Comparative Examples 1 and 2. Tables 3 and 4 and FIGS. 1 and 2 show the powder sample FSM / 8-B that was not pressed.
The data of (Synthesis Example 2) is also described for reference.

[0056]

[Table 3]

[0057]

[Table 4]

In Comparative Examples 1 to 4 in which octyltrimethylammonium bromide was not added at the time of molding, as shown in Table 4, the specific surface area was FSM / 8-B which was not subjected to pressure molding (Synthesis Example 2). It became a small value compared with the numerical value of. In addition, it was found that the packing density was improved by increasing the molding pressure, while the specific surface area was decreased. A decrease in the specific surface area means a decrease in the amount of adsorption when the porous molded body is used as an adsorbent. On the other hand, Example 1 in which octyltrimethylammonium bromide was added during molding
In Nos. To 4, as shown in Table 3, the specific surface area was maintained at substantially the same value as that of FSM / 8-B (Synthesis Example 2) not subjected to pressure molding. Also, the packing density was increased by increasing the molding pressure, and the specific surface area was kept almost constant.

Further, as shown in FIG. 1, the water vapor adsorption isotherm of the porous molded body obtained in Example 3 is the same as the vapor pressure of FSM / 8-B (Synthesis Example 2) which has not been pressed. It was almost equal to the adsorption isotherm, and it was found that the porous molded body obtained in Example 3 maintained the adsorption characteristics of FSM / 8-B (Synthesis Example 2). On the other hand, as shown in FIG. 2, the adsorption isotherms of the porous molded bodies obtained in Comparative Examples 1 and 2 are as follows:
This is different from the water vapor adsorption isotherm of FSM / 8-B (Synthesis Example 2) not subjected to pressure molding. As the molding pressure increases, the position of the inflection point of the curve (the value of the amount of water adsorption in the portion where the slope changes greatly) decreases. It was found that mesopores had collapsed. Further, in the region where the inclination is small after the inflection point in FIG. 2, the position of the curve decreases as the molding pressure increases, so that in the porous molded bodies obtained in Comparative Examples 1 and 2, It was found that the pore volume decreased due to the collapse of the pores or the gap between the porous particles.

[Production of Porous Molded Articles] (Examples 5A to 5E) 8.06 g of ion-exchanged water (additive) was used instead of 25 g of octyltrimethylammonium bromide (additive) (based on 100 parts by weight of porous particles). A porous molded body was obtained in the same manner as in Example 1 except that the amount of the additive was 16.12 parts by weight) and the pressing force of the hydrostatic press was set to 3000 kg / cm ² . In addition, FSM at the time of pressure molding
The water content in the pores of / 8-B (porous particles) was 20% by weight based on the total weight of the porous particles. This operation was repeated a total of five times, and each was performed in Examples 5A, 5B,
5C, 5D and 5E.

(Comparative Examples 5A to 5E) Porous molded articles were obtained in the same manner as in Examples 5A to 5E except that no ion-exchanged water was used. Each of Comparative Examples 5A, 5B, 5C and 5D
And 5E.

[Evaluation of porous molded body] Examples 5A to 5E
The specific surface area and the packing density of the porous molded bodies obtained in Comparative Examples 5A to 5E were measured in the same manner as described above. The variation of the specific surface area was evaluated by obtaining a value of a standard deviation (σ) from an average value. Table 5 shows the results of Examples 5A to 5E, and Table 6 shows the results of Comparative Examples 5A to 5E.

[0063]

[Table 5]

[0064]

[Table 6]

As is clear from comparison between Tables 5 and 6, Examples 5A to 5E in which ion-exchanged water was added at the time of pressure molding were comparative examples in which ion-exchanged water was not added at the time of pressure molding. The specific surface area was larger than 5A to 5E, and the value of the standard deviation (σ) representing the variation was smaller. Therefore, in Examples 5A to 5E, it was shown that a porous molded body having a large specific surface area was obtained with high reproducibility.

[Production of Porous Molded Body] (Example 6) 50 g of the porous particles before firing obtained in Synthesis Example 6 were weighed in a thick vinyl chloride bag. On the other hand, ion-exchanged water (additive) such that the water content in the pores is 5% by weight based on the total weight of the porous particles.
Was added (the amount of the additive was 2.38 parts by weight based on 100 parts by weight of the porous particles), and the mixture was uniformly mixed by vibrating for 10 minutes or more until the lumps disappeared. This mixture is sealed in another polyvinyl chloride bag and 3,000 kg in a hydrostatic press.
/ M ² for 1 minute. The obtained sample is crushed in a mortar to adjust the particle size to 0.2 to 0.3 mm, and then calcined in air at 550 ° C. for 6 hours to remove the substance in the pores to obtain a porous molded body. Obtained.

(Examples 7 to 10) The water content in the pores was 1
Except having become 0 weight%, 12 weight%, 15 weight%, and 20 weight%, it carried out similarly to Example 6, and obtained the porous molded object of Examples 7, 8, 9, and 10, respectively. When the amount of water in the pores is 10% by weight, 12% by weight, 15% by weight, and 20% by weight, the amount of the additive (ion-exchanged water) with respect to 100 parts by weight of the porous particles is 7.38% by weight. Department,
9.38 parts, 12.38 parts, and 17.38 parts by weight.

Comparative Example 6 A porous molded body was obtained in the same manner as in Example 6, except that no ion-exchanged water was used.

[Evaluation of Porous Molded Article] The specific surface area, packing density and pore volume of the porous molded articles obtained in Examples 6 to 10 and Comparative Example 6 were measured in the same manner as described above. Table 7 shows the results. Further, the water vapor adsorption isotherms of the porous molded bodies obtained in Examples 6, 8 to 10 and Comparative Example 6 were measured by the same method as described above. FIG. 3 shows the obtained water vapor adsorption isotherm. In Table 7 and FIG. 3, data of FSM / 10 (without pressure molding) obtained in Synthesis Example 6 are also shown for reference.

[0070]

[Table 7]

As shown in Table 7, Examples 6 to 10 and FS
M / 10 (without pressure molding) indicates almost the same specific surface area and pore volume, whereas the value of the specific surface area and pore volume of Comparative Example 6 is FSM / 10 (without pressure molding). Was significantly below the value of. When the amount of water added during pressure molding is within the above range, the specific surface area and the pore volume approach the value of FSM / 10 (no pressure molding) as the amount of water added increases. I understand.

[Production of Porous Molded Articles] (Examples 11A to 11E) In place of FSM / 8-B (porous particles) before firing obtained in Synthesis Example 2, the same amount of FSM / FSM before firing was used. Using 16-C (porous particles) and using 9.48 g of ion-exchanged water (additive) instead of 25 g of octyltrimethylammonium bromide (additive) (the amount of the additive is 18.1 g per 100 parts by weight of the porous particles). 96 parts by weight), and the pressing force of the hydrostatic press was 3000 kg / c.
A porous molded body was obtained in the same manner as in Example 1 except that m ² was used. The water content in the pores of the porous particles during the pressure molding was 20% by weight. This operation was repeated a total of five times, and the operations were performed in Examples 11A, 11B, 11C, and 11
D and 11E.

(Comparative Examples 7A to 7E) Porous molded articles were obtained in the same manner as in Examples 11A to 11E except that no ion-exchanged water was used. Each of Comparative Examples 7A, 7B, 7C,
7D and 7E.

[Evaluation of Porous Molded Body] Examples 11A to 1
The specific surface area and the packing density of the porous molded bodies obtained in 1E and Comparative Examples 7A to 7E were measured in the same manner as described above.
The variation of the specific surface area was evaluated by obtaining a value of a standard deviation (σ) from an average value. Tables 8 and 9 show the results of Examples 11A to 11E and Comparative Examples 7A to 7E, respectively.

[0075]

[Table 8]

[0076]

[Table 9]

As is clear from comparison between Tables 8 and 9, Examples 11A to 11 in which ion-exchanged water was added during pressure molding.
E had a larger specific surface area and a smaller value of the standard deviation (σ) representing variation than Comparative Examples 7A to 7E in which ion-exchanged water was not added at the time of pressure molding. Therefore,
In Examples 11A to 11E, it was shown that a porous molded body having a large specific surface area was obtained with high reproducibility.

[0078]

As described above, according to the present invention,
While maintaining the adsorption characteristics of the porous particles at a high level, repeatedly forming the densified porous particles, with good reproducibility,
It is possible to provide a method for producing a porous molded body that can be obtained.

[Brief description of the drawings]

FIG. 1 shows a porous molded article and FSM obtained in Example 3.
FIG. 9 is a diagram showing a water vapor adsorption isotherm of / 8-B.

FIG. 2 is a view showing a water vapor adsorption isotherm of the porous compacts and FSM / 8-B obtained in Comparative Examples 1 and 2.

FIG. 3 is a view showing water vapor adsorption isotherms of the porous molded products obtained in Examples 6, 8 to 10 and Comparative Example 6 and FSM / 10 (without pressure molding).

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Yuri Sasaki 41-cho, Yokomichi, Nagakute-cho, Aichi-gun, Aichi Prefecture Inside Toyota Central Research Laboratory Co., Ltd. (72) Inventor Kazuhisa Yano, Nagakute-cho, Nagakute-cho, Aichi-gun, Aichi Prefecture 41, Yokomichi, Toyota Central Research Laboratory Co., Ltd. (72) Inventor Mitsumasa Horii, 41, Chuchu Yokomichi, Nagakute-machi, Aichi-gun, Aichi Prefecture, Japan Toyota Motor Central Research Laboratory Co., Ltd. (72) Inventor Yoshiaki Fukushima Aichi 41, Chuo-ku, Yokomichi, Nagakute-cho, Aichi-gun, Aichi Prefecture Inside Toyota Central Research Laboratory Co., Ltd. (72) Inventor Hideaki Sato 1-1-1, Showa-cho, Kariya-shi, Aichi Prefecture Denso Corporation (72) Inventor Michiyoshi Sakurai Aichi 1-1-1 Showa-cho, Kariya-shi, Japan Inside Denso Co., Ltd. (72) Inventor Saya Yabuki 2-846 Kozoji-cho, Kasugai-shi, Aichi Address F-term in Fuji Silysia Chemical Co., Ltd. (reference) 4G066 AA22B AA30A AB09D AB21D BA26 BA31 BA36 BA38 FA05 FA22 FA37 4G073 BA63 CB06 CZ54 FC03 FC19 UA06

Claims (4)

[Claims] The fine particles are prepared by mixing an aggregate of porous particles having a plurality of pores and an additive which is non-reactive with the porous particles and can enter the inside of the pores. A first step of introducing the additive into the pores and gaps between the porous particles to obtain a mixture of the porous particles and the additive; and a second step of pressing the mixture to obtain a molded body And a third step of removing the additive from the molded article. A method for producing a porous molded article, comprising: 2. In the first step, the additives 2 to 70 are added to 100 parts by weight of the aggregate of the porous particles.
2. The method according to claim 1, wherein parts by weight are mixed. 3. The method according to claim 1, wherein the porous particles are porous particles having a hydrophilic surface, and the additive is a polar additive. 4. The porous particle is a mesoporous silica having a plurality of mesopores, and the additive comprises a polar liquid and an ammonium salt represented by the following general formula (1). The method according to any one of claims 1 to 3, wherein the method is at least one compound selected from the group. Embedded image [Wherein, R ¹ , R ² and R ³ may be the same or different, and each may be a linear or branched monovalent organic group having 1 to 4 carbon atoms;
R ⁴ is a linear or branched monovalent organic group having 5 or more carbon atoms;
X represents a halogen atom or a hydroxyl group, respectively. ]