JPH05105513A - Production of carbonaceous inorganic oxide composite - Google Patents

Abstract

PURPOSE:To safely and readily obtain a carbonaceous inorganic oxide composite excellent in mechanical strength and uniformity with good reproducibility by mixing an inorganic oxide having a porous structure with a phenolic resin and then heat-treating the resultant mixture. CONSTITUTION:A carbonaceous inorganic oxide composite is obtained by mixing an inorganic oxide having a porous structure with a phenolic resin and then heat-treating the resultant mixture. For example, silica, alumina, magnesia, titania and zirconia are cited as the inorganic oxide and the specific surface area is preferably 5-500m<2>/g or the pore volume is preferably about 0.1-1.3ml/g.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a carbonaceous inorganic oxide composite useful as a catalyst, a catalyst carrier, an adsorbent, an electrode material, a conductive filler, etc. in the organic chemical industry, the inorganic chemical industry or the electrochemical industry. Regarding how to make a body.

[0002]

2. Description of the Related Art Carbonaceous substances, typified by activated carbon, are often produced from natural raw materials, so that they contain impurities and a small amount of oxygen derived from hydroxyl groups remaining in the production process. In some cases, the component is substantially composed of carbon (for example, activated carbon industry, p. 51, Heavy Chemical Industry News Agency). Carbonaceous substances are widely used as catalysts, catalyst carriers, adsorbents, electrode materials, conductive fillers, etc. by taking advantage of their characteristics.

However, carbonaceous substances, such as activated carbon, have the drawback of lower mechanical strength than silica, alumina, and the like which are inorganic oxides. Therefore, in order to combine a carbonaceous substance with an inorganic oxide to improve its mechanical strength, it is necessary to produce a carbonaceous inorganic oxide complex having new physicochemical properties. Attempts are known.

For example, J. Catal. , 114, 29
1-302 (1988), alumina carrier 600-70.
A method for producing a carbonaceous inorganic oxide composite in which ethylene gas or cyclohexene vapor is supplied and carbonized to carry a carbonaceous material on alumina, which is maintained at a high temperature of 0 ° C., and US Pat. , Silica-alumina, etc. are kept at 605 ° C., and vapors of cyclohexane, pentane, cyclohexene, hexane, etc. are supplied thereto to carry a carbonaceous material on the surface.
A method of making a coated carbonaceous inorganic oxide composite is disclosed.

However, in the above-mentioned reference, in carrying or coating a carbonaceous material on an inorganic oxide, the kind of the raw material compound to be carbonized, the introduction conditions of the raw material gas or steam, and the temperature and time during the carbonization. It is described that such conditions greatly affect the properties of the obtained carbonaceous inorganic oxide composite and that composites having different properties can be obtained.

[0006]

According to the technique of the above cited reference, a carbonaceous inorganic oxide composite having improved mechanical strength, which is a weak point of conventional carbonaceous substances, is certainly obtained. However, the manufacturing method uses gas and vapor of organic compounds
It is necessary to introduce it onto an inorganic oxide kept at a high temperature of 0 to 700 ° C. and carbonize it. Considering an industrial manufacturing method, a complicated device is required and a safety measure is required. ..

Further, as described above, the various conditions at the time of manufacture are
Since it has a great influence on the physical and chemical properties of the obtained composite, it has a serious defect of lacking reproducibility, homogeneity and simplicity, which are the most important factors in industrial production methods.

Therefore, there has been a demand for a technique which is excellent in mechanical strength, excellent in reproducibility and uniformity, and which can easily produce a composite.

[0009]

Means for Solving the Problems The inventors of the present invention have made earnest studies in view of such a situation. As a result, surprisingly, when a phenol resin is used, the carbonaceous inorganic oxide composite is safe, convenient and reproducible. The inventors have found that the body can be manufactured, and have completed the present invention. That is, the present invention provides a carbonaceous inorganic oxide composite obtained by mixing an inorganic oxide having a pore structure with a phenol resin and then heat treating the mixture, and a method for producing the same.

The present invention will be described in more detail below.

According to the present invention, the carbonaceous inorganic oxide composite is produced by using an inorganic oxide having a pore structure and a phenol resin.

In the present invention, an inorganic oxide having a pore structure is used. Although it is difficult to uniquely define this pore structure, it can be defined by the specific surface area (surface area per unit weight of inorganic oxide) of the inorganic oxide or the pore volume. In the present invention, the specific surface area is usually 1 to 600 m
² / g, preferably 5 to 500 m ² / g, or the pore volume is usually 0.05 to 1.5 ml / g, preferably 0.1.
~ 1.3 ml / g of inorganic oxide is used. Specific surface area of less than 1 m ² / g or pore volume of 0.05 ml /
If it is less than g, when the obtained composite is used as a catalyst, an adsorbent or the like, the performance may be deteriorated, which is not preferable.

On the other hand, if the specific surface area exceeds 600 m ² / g, it may be difficult to prepare when mixed with the phenol resin and prepared. If the pore volume exceeds 1.5 ml / g, the mechanical strength may decrease.

As the inorganic oxide of the present invention, any inorganic oxide can be used regardless of the acid / base inherent in the oxide or the oxidizing / reducing property.
Examples of the inorganic oxides include single metal oxides such as silica, alumina, magnesia, titania, and zirconia, and oxides of two or more metals, which are so-called complex oxides. Then, silica-alumina, silica-titania, etc. can be mentioned. These inorganic oxides may be crystalline or amorphous and can be used. When the inorganic compound is crystalline, its crystal structure is not particularly limited, and may have a two-dimensional layered structure or a three-dimensional three-dimensional crystal structure. Furthermore, there is no particular limitation on the shape of these inorganic oxides, and they may be spherical, pelletized, honeycomb-shaped or the like, or may be non-molded powdery. Various shapes can be used.

The phenol used in the present invention
The resin does not have to be specially manufactured, and a commercially available resin can be used. It does not matter whether it is a powder or a liquid dissolved in a solvent. Generally, a phenol resin is produced from phenols and formaldehyde, but the phenols are not particularly limited, and phenol, cresol, xylenol, etc. may be used alone or in combination. A manufactured product can also be used. Further, the phenol resin is roughly classified into a resole-based phenol resin and a novolac-based phenol resin according to the production method thereof, and any of them can be used in the present invention. Further, the phenol resin is produced in various average molecular weights depending on the polymerization conditions, but the average molecular weight is not particularly limited.

In the present invention, the carbonaceous inorganic oxide composite is produced by mixing the phenol resin and the inorganic oxide and then heat-treating the mixture, but the mixing method is not particularly limited. For example, when using a powdery phenolic resin, the powdery phenolic resin and the inorganic oxide may be physically mixed. Alternatively, the powdery phenolic resin may be dissolved in a solvent, impregnated with an inorganic oxide, and then dried to remove the solvent, and the mixture may be mixed by a so-called impregnation method. In this case, the solvent is not particularly limited as long as it can dissolve the phenol resin, and for example, acetone, ethanol or methanol can be used. Of course, a liquid phenol resin dissolved in a commercially available solvent can be used as it is for impregnation.

Further, the heat treatment method is not particularly limited, and when a solvent is used for impregnating the phenol resin, the heat treatment may be carried out after removing the solvent in advance.

This heat treatment may be carried out while supplying gas or may be carried out without supplying gas. When the heat treatment is performed while supplying the gas, for example, at a low temperature, the heat treatment may be performed in an atmosphere containing oxygen, and the atmosphere may be switched to an inert gas such as nitrogen, or the atmosphere may be an inert gas atmosphere such as nitrogen from the beginning. You may heat-process with. During this heat treatment, the phenol resin is carbonized. However, if the phenol resin is exposed to an oxidizing atmosphere at too high a temperature, the carbonized phenol resin burns, so that the remaining effective carbon for the phenol resin used. The quality may be reduced.

The heat treatment may be performed while raising the temperature stepwise, or may be performed at a predetermined temperature at a constant rate of temperature increase. Generally, the processing temperature may be 150 ° C to 1200 ° C. If the temperature is lower than 150 ° C, the phenol resin may not be sufficiently cured. On the other hand, when the temperature exceeds 1200 ° C, the surface area of the inorganic oxide may be remarkably reduced, but the temperature may be higher than 1200 ° C as long as the inorganic oxide does not change structurally.

The heat treatment time is not particularly limited, and the temperature may be lowered immediately after reaching a predetermined temperature, or may be maintained at the predetermined temperature for a desired time.

Generally, the phenol resin is cured at a heat treatment temperature of up to about 200 ° C., and when the treatment temperature is further raised, the temperature is up to about 700 ° C. and almost no oxygen atoms derived from the phenol resin remain. Therefore, it is necessary to pay particular attention to the thermal change of the phenol resin during the heat treatment. That is, when it is preferable to leave oxygen atoms in the phenol resin depending on the intended use, the final treatment temperature should be determined by fully grasping the behavior of the raw phenol resin to heat. However, even if the oxygen atom disappears, it is possible to introduce a functional group containing oxygen again by a known method.

The ratio of the carbonaceous material to the carbonaceous inorganic oxide composite obtained by the present invention varies depending on the use. For example, when the carbonaceous inorganic oxide composite is used as a catalyst or a catalyst support, the carbonaceous material is used. In general, the loading rate of 0.1 to 15% is sufficient, and when used as an adsorbent, the loading rate can be changed in consideration of the adsorption amount, but for example, 0.5 to 25%. Can be used. When it is used as an electrode material or the like, a material having a supporting rate of 0.1 to 50% can be used. Generally, if the carbonaceous content is less than 0.1%, the original effect of carbonaceous material is small, and if it exceeds 50%, the effect of further increasing is small. When the ratio of contained carbonaceous matter is high, it may not be possible to prepare all at once, but at this time, it may be prepared by repeating mixing and heat treatment. In the present invention, the ratio of carbonaceous matter may include oxygen atoms depending on the heat treatment temperature as described above, so that all components supported on the inorganic oxide after the heat treatment. Should be construed as the ratio of to the carbonaceous inorganic oxide composite.

[0023]

EXAMPLES The present invention will be described below with reference to examples.
Needless to say, the present invention is not limited to these examples. Example 1 0.2 ml of powdered novolac-based phenol resin (HP-309NS, Hitachi Chemical Co., Ltd.) in 20 ml of ethanol
28 g was dissolved. To this, 10.0 g of spherical silica gel having a surface area of 70 m ² / g and a pore volume of 1.05 ml / g (Carrieract-50 manufactured by Fuji Devison Chemical Co., Ltd.) was added. The ethanol was evaporated to dryness on a 40 ° C. hot bath and then kept in an 80 ° C. thermostat for 16 hours. The dried sample was put in an electric furnace and heated to 180 ° C. at a rate of 5 ° C./min under a nitrogen gas flow. After the temperature was kept at 180 ° C. for 1 hour, the temperature was raised to 600 ° C. at a rate of 5 ° C./min, and heat treatment was performed at 600 ° C. for 4 hours. The obtained carbonaceous inorganic oxide composite had 1.2% carbonaceous matter. Examples 2 to 5 The weight of the phenol resin was 0.904 g and 1.0, respectively.
4.5%, 8.3%, 13.9%, and 2% in exactly the same manner as in Example 1 except that 8 g, 3.37 g, and 6.75 g were used.
A carbonaceous inorganic oxide composite having a carbonaceous content of 3.4% was obtained. The Fourier transform infrared spectroscopic spectrum of the carbonaceous inorganic oxide composite having 8.3% carbonaceous matter of Example 3 is shown in FIG. For comparison, the raw material phenol resin and the silica gel pellet are also shown in FIG.
Further, the X-ray diffraction pattern is shown in FIG. The surface area measured by the BET method was 135 m ² / g. Also,
The pore volume was 0.9 ml / g. The pore volume was 0.9 ml / g. Furthermore, it is 10 with a Kiya type hardness tester.
When the strength of each particle was measured, the average strength was 5.4 kg. For comparison, molded activated carbon (Takeda Yakuhin Co., Ltd., granular coconut shell activated carbon; trade name Shiraea C)
Was measured, and the average value of 10 was 3.9 kg (long axis direction) and 4.9 kg (diameter direction). Example 6 10.0 g of spherical silica gel having a surface area of 110 m ² / g and a pore volume of 1.05 ml / g (Carrieract-30 manufactured by Fuji Devison Chemical Co., Ltd.), a powdered novolac-based phenol resin (Hitachi Chemical Co., Ltd. Industry Co., Ltd., HP-309NS)
A carbonaceous inorganic oxide composite was prepared in exactly the same manner as in Example 1 except that 1.08 g was used. The resulting carbonaceous inorganic oxide composite had a carbonaceous content of 7.3%. B
The surface area measured by the ET method was 158 m ² / g. The pore volume was 0.9 ml / g. Example 7 Except that 10.0 g of spherical alumina (NKH1-24 manufactured by Sumitomo Chemical Co., Ltd.) having a surface area of 110 m ² / g and a pore volume of 0.90 ml / g was used as the inorganic oxide,
A carbonaceous inorganic oxide composite was prepared in exactly the same manner as in Example 1. The obtained carbonaceous inorganic oxide composite was 7.9%.
Had a carbonaceous content of. The surface area measured by the BET method was 138 m ² / g. The pore volume is 0.8m
It was 1 / g. Example 8 Example 1 was repeated except that 10.0 g of alumina pellets (DC-2382 manufactured by Dia Catalyst Co., Ltd.) having a surface area of 200 m ² / g and a pore volume of 0.95 ml / g was used as the inorganic oxide. A carbonaceous inorganic oxide composite was prepared in exactly the same manner as in 1. The obtained carbonaceous inorganic oxide composite,
It had 8.2% carbonaceous matter. The pore distribution measured by the mercury penetration method is shown in FIG. Example 9 As an inorganic oxide, a spherical titania having a surface area of 39.5 m ² / g and a pore volume of 0.33 ml / g (Sakai Chemical Industry Co., Ltd.)
A carbonaceous inorganic oxide composite was prepared in exactly the same manner as in Example 1 except that 10.0 g of the product was used, the final heat treatment temperature was 450 ° C., and mixing was performed 3 times. The obtained carbonaceous inorganic oxide composite had 5.5% carbonaceous matter. Example 10 A carbonaceous inorganic oxide composite was prepared in exactly the same manner as in Example 3 except that the final heat treatment temperature was 900 ° C. The obtained carbonaceous inorganic oxide composite had 7.5% carbonaceous matter. Example 11 Instead of a novolac phenolic resin, a resole phenolic resin (Showa Highpolymer Co., Ltd., BRM-421)
A carbonaceous inorganic oxide composite was prepared in exactly the same manner as in Example 3 except that 15 g was used and methanol was used instead of ethanol. The obtained carbonaceous inorganic oxide composite had a carbonaceous substance of 7.9%. Example 12 A carbonaceous inorganic oxide composite was prepared under exactly the same conditions as in Example 3 in order to examine the reproducibility of the method for preparing a carbonaceous inorganic oxide composite. Was.

[0024]

As described above, according to the present invention, it is possible to easily, safely and reproducibly produce a carbonaceous inorganic oxide composite having excellent mechanical strength.

[Brief description of drawings]

1 is a diagram showing a Fourier transform infrared spectroscopic spectrum of a carbonaceous inorganic oxide composite having 8.3% carbonaceous matter of Example 3. FIG.

FIG. 2 is a diagram showing a Fourier transform infrared spectroscopic spectrum of a powdery novolac-based phenol resin (Hitachi Chemical Co., Ltd., HP-309NS).

FIG. 3 is an X-ray diffraction pattern (measurement condition; 35K) of the carbonaceous inorganic oxide composite having 8.3% carbonaceous matter of Example 3.
v, 20mA, Cu Kα ray)

FIG. 4 is a diagram showing a pore distribution measured by a mercury intrusion method of a carbonaceous inorganic oxide composite having 8.2% carbonaceous matter of Example 8.

Claims (1)

[Claims] 1. A method for producing a carbonaceous inorganic oxide composite obtained by mixing an inorganic oxide having a pore structure and a phenol resin and then heat treating the mixture.