JP2005041748A - Carbon porous body and its manufacturing process - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a carbon porous body that has excellent properties using a resin foam as a template to realize a three dimensional network structure and utilizing a polyimide resin as a carbon source, and to provide a process for manufacturing the same. <P>SOLUTION: The carbon porous body is obtained by impregnating a thermosetting resin foam with a polyimide precursor resin, imidating the impregnated resin by dehydration, continuously charging the polyimide into an inner and outer space of the thermosetting resin foam and carbonizing the polyimide resin. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a carbon porous body and a method for producing the same, and more particularly, to a carbon porous body having high strength and faithful reproducibility with respect to a design shape, and a method for producing the same. .

  As is well known, a carbon porous body is a porous body in which carbon components form a three-dimensional network structure. This porous carbon material is lightweight because it is porous, and if the carbon density is increased, it can have high mechanical properties. Since carbon is a material, it has excellent heat resistance and chemical resistance. In addition, it is a material excellent in absorbability, adsorbability, and permeability to gases and liquids due to its porosity, and is expected to be widely used in industrial applications. The macro structure of carbon constituting this porous body is a three-dimensional network structure as described above, but the structure of the constituent carbon may be controlled to an amorphous structure or a highly crystalline structure (graphite structure). In addition, various applications are expected in the electrical and electronic industrial fields.

  Conventionally, as a method for producing such a carbon porous body, a method of baking and producing a resin foam (foam) such as phenol and urethane is an old knowledge. However, in these methods, the carbonization yield of the resin is generally low. Therefore, the obtained carbon porous body has a defect that the three-dimensional network structure which the starting material had by firing becomes a structure in which the volume contraction is extremely large, and the strength is not high. As a method for improving such drawbacks, a method of manufacturing a carbon porous body having a high carbon density by impregnating a resin such as furan into a resin foam such as urethane foam and firing it is proposed. (For example, Patent Document 1). However, in these methods, since the carbon skeleton shape and carbon density of the organic material used as the impregnation are insufficient, the strength after firing is weak and unusable, the firing shrinkage ratio is large, It had the disadvantage of being inferior in dimensional accuracy.

  In contrast, a composite carbon composition in which an inorganic substance such as carbon black is added in addition to a liquid organic substance such as furan resin is used as a carbon source to impregnate the resin foam, thereby increasing the carbon density of the impregnated resin foam, There has been proposed a method for obtaining a carbon porous body having excellent strength and good dimensional accuracy by curing an impregnated foam (impregnated composite) having an improved carbon density, followed by firing (Patent Documents 2 and 3). ). However, this method has a disadvantage that a process for adding carbon black to a liquid organic substance is required, and further, the cell of the resin foam (pore space: bubbles) rather than the particle size of the particulate matter made of carbon black. Must be open, thereby limiting the refinement of the pore diameter of the three-dimensional network structure, and the dense carbon porous body with a fine cell diameter (diameter size of each bubble) It is difficult to manufacture the carbon composition, and the carbon composition constituting the finished carbon porous body is biased to an amorphous structure, and the carbon composition cannot have crystallinity.

  Further, a method has been proposed in which a polycarbodiimide resin is used as a carbon source impregnated into a resin foam to obtain a carbon porous body excellent in both dimensional stability and strength (Patent Document 4). However, since the polycarbodiimide resin used as the carbon source is amorphous, the carbon structure obtained by firing the resin cannot obtain a crystalline material. Therefore, even if the carbon porous body of the present invention has excellent dimensional stability and strength, high crystallinity cannot be obtained, and its application can not be expanded.

  Thus, as a carbon source, when considering a suitable resin material that can be changed to an amorphous carbon structure or a crystalline carbon structure, a polyimide resin having an excellent orientation of the carbon skeleton is obtained. It is known to be powerful. For example, as described in Patent Document 5, it is possible to obtain a graphite sheet that is rich in flexibility and toughness and excellent in thermal conductivity by gradually heating and baking a polyimide film in an inert gas. it can. Therefore, it can be presumed that a carbon porous body having high crystallinity can be obtained by impregnating a resin foam with this polyimide resin and baking it. However, as is well known, polyimide is a resin that has a high glass transition temperature and is insoluble in any solvent, making it difficult to form a solution. Therefore, it is impossible to impregnate the resin foam with polyimide. If the resin foam cannot be impregnated, it cannot be formed into a three-dimensional network structure even if it can be baked to obtain a highly crystalline carbon structure. That is, in the prior art, it has been difficult to produce a porous carbon body by using a resin foam as a mold material for realizing a three-dimensional network structure and using a polyimide resin as a carbon source.

Japanese Patent Publication No.53-7536 JP 59-146717 A JP-A-8-48509 JP-A-6-32677 JP 2000-247619 A

  The present invention has been made in view of the above-described conventional circumstances, and uses a carbon foam having excellent characteristics obtained by using a resin foam as a mold material for realizing a three-dimensional network structure and using a polyimide resin as a carbon source, and An object of the present invention is to provide a method for producing a porous carbon body that can produce the porous carbon body.

  In order to solve the above-mentioned problems, the present inventors first made intensive studies on a method capable of coating a polyimide resin to every corner of a porous resin foam. As a result, it is difficult to impregnate the polyimide resin directly with the resin foam, as described above. Therefore, the resin precursor is impregnated with a polyimide precursor that is relatively easy to make a solution, and after the impregnation, dehydration is performed. As a result, it was possible to obtain a state in which polyimide resin was impregnated into a resin foam if polyimide was formed by reaction. However, when a prototype was actually manufactured, it was found that it was difficult to maintain a three-dimensional network structure in the subsequent polyimide formation step, although it was possible to impregnate the resin foam with the polyimide precursor. Therefore, the present inventors formed a resin foam impregnated with a polyimide precursor, set the heat treatment process for polyimidizing this impregnated resin foam under various conditions, and conducted careful experiments and examinations. As a result, the following findings were obtained.

  The graph of FIG. 1 shows the decomposition weight loss curves accompanying the respective temperature rise treatments of polyamic acid, which is a polyimide precursor, urethane foam used as a resin foam, polyimide-impregnated polyurethane foam, and polyimide. The horizontal axis of the graph is scaled from 0 ° C. to 700 ° C. as the heating temperature. On the other hand, on the vertical axis of the graph, the weight ratio indicating the abundance of each substance at the start of heating determined by thermogravimetric analysis (TGA) as 100% is graduated.

  As shown in FIG. 1, when the temperature of the polyamic acid is raised, dehydration imidization starts from about 100 ° C., imidization proceeds with further temperature rise, and imidation is completed at 200 to 250 ° C. On the other hand, the urethane resin used as the resin foam is stable up to about 200 ° C., half of the amount decomposes at about 350 ° C., and the entire amount of decomposition ends at around 540 ° C. As is apparent from the decomposition curve of this urethane resin, decomposition hardly proceeds at temperatures up to a little over 200 ° C. At the above-described imidization end temperature of polyamic acid of 235 ° C., the decomposition of the urethane resin proceeds to some extent. In addition, the polyimide begins to decompose at around 500 ° C., which is close to the temperature of 540 ° C. at which the above-described decomposition of the polyurethane ends, and ends at 620 ° C.

  Based on the above TGA measurement results, in order to obtain a polyimide-impregnated urethane resin foam in which all the inner and outer spaces of the urethane resin foam are filled with the polyimide resin while maintaining the original three-dimensional network structure, the temperature is increased at a constant rate. It turns out that it is not possible to go uniformly, and it is necessary to raise the temperature stepwise. More specifically, it is important to maintain the impregnated resin foam at an appropriate temperature in the range of 100 ° C. to 200 ° C. for a predetermined time after impregnating the urethane resin foam with polyamic acid. The temperature in the range of 100 ° C. to 200 ° C. means a temperature range suitable for imidization of the polyamic acid and a temperature range in which the decomposition of the urethane resin does not start in earnest. The predetermined time is a time required until almost the entire amount of the polyamic acid impregnated in the resin foam placed in the temperature range of 100 ° C. to 200 ° C. is imidized. By passing through such an imidization step in which the temperature and time are set, the polyimide resin is sufficiently impregnated without contracting or deforming the three-dimensional network structure that the original resin foam had for the first time. The resin foam is obtained.

  By the way, when the polyimide-impregnated resin foam is subjected to thermogravimetric analysis, it can be seen that, as shown in the graph of FIG. 1, it exhibits a weight reduction behavior intermediate between the curve of the polyimide alone and the curve of the urethane resin alone.

  As described above, if a urethane resin foam (foam / polyimide / composite) impregnated with a polyimide resin is obtained, it may be fired at a high temperature in a low oxygen inert atmosphere. As a result, the resin three-dimensional network structure is carbonized while maintaining the three-dimensional network structure. The carbon porous body obtained in this way has a structure with excellent carbon orientation reflecting the excellent orientation of the carbon skeleton of polyimide as a carbon source. Furthermore, it is possible to make the carbon structure amorphous by appropriately selecting the type of polyimide precursor to be used. That is, if a polyimide-impregnated resin foam (foam / polyimide / composite) can be obtained, it becomes possible to freely obtain a carbon porous body having a structure protruding into both crystalline and amorphous. Moreover, this carbon porous body can have high strength and excellent dimensional stability because the carbon source is a polyimide having excellent carbon density and carbon orientation.

  The present invention has been made on the basis of the above-mentioned knowledge, and the carbon porous body according to the present invention is obtained by carbonizing a polyimide resin continuously filled in the inner and outer spaces of an open-cell thermosetting resin foam. The obtained porous carbon material is characterized in that the polyimide resin is obtained by polyimidizing a polyimide precursor resin impregnated in the thermosetting resin foam.

  Also, the method for producing a porous carbon body according to the present invention comprises impregnating a polyimide precursor resin into an open-cell thermosetting resin foam, dehydrating and imidating the impregnated resin, and the inner and outer spaces of the thermosetting resin foam. It is characterized in that a porous carbon material is obtained by continuously filling a polyimide resin with carbon and carbonizing the polyimide resin.

  The open cell property of the thermosetting resin foam in the present invention does not mean that all the cells (bubbles) of the thermosetting resin foam are in communication, but at least a part of the cells is in communication. This means that closed cells may be present in the resin foam. Rather than being good, it is possible to variously set the air permeability of the carbon porous body finally obtained in the present invention by appropriately controlling the ratio of open cells and closed cells in the resin foam. Therefore, it can be said that a state in which open cells and closed cells are mixed is preferable. Of course, a thermosetting resin foam composed of open cells to the extent that it is almost completely is also a thermosetting resin foam useful in the present invention.

According to the present invention having the above-described configuration, the following effects can be obtained.
(I) The crystallinity of the polyimide resin can be controlled by selecting its raw material, and an amorphous carbon porous body and a graphite porous body can be made from different crystalline polyimides, respectively. Therefore, according to the present invention, a carbon porous body having high conductivity and high thermal conductivity can be easily obtained.
(Ii) Carbon obtained by varying the cell size and air permeability (depending on the proportion of open cells and closed cells in the resin foam) of the “open cell thermosetting resin foam” used as the resin foam The cell size and air permeability of the porous body can be controlled. By being able to control the pores of the carbon porous body manufactured in this way, when used in applications such as filters, catalyst carriers, and heat dissipation materials, it is possible to easily provide products having pores optimized for the application. .
(Iii) Moreover, since the polyimide used as a carbon source has small shrinkage | contraction by baking, it is excellent in the shape retainability of the three-dimensional network structure before and behind baking. Therefore, for example, a carbon product having a shape as designed can be easily provided by molding a resin foam in advance or cutting and molding and then impregnating with a polyimide precursor to obtain a carbon porous body. The actual benefit of obtaining a carbon molded product without processing a poorly workable carbon material by cutting, etc. is that, in providing the product, quality improvement, reduction of manufacturing cost, realization of high-mix low-volume production, etc. Can have a wide range of effects.
(Iv) By using melamine resin foam or polyester urethane foam as the resin foam in the present invention, the polyimide precursor impregnation step is easy, and the amount of carbide after firing is extremely small. Can be obtained almost purely.

Hereinafter, embodiments of the present invention will be described.
As the polyimide precursor resin used in the present invention, a polyamic acid obtained by a reaction between an aromatic acid anhydride and an aromatic diamine or an ester thereof is preferable. When such a polyimide composed of an aromatic dianhydride and an aromatic diamine is baked, it can provide a carbon material with extremely high carbon yield and good performance. Examples of the acid dianhydride include pyromellitic dianhydride (PMDA), biphenyltetracarboxylic dianhydride (BPDA), and benzophenone tetracarboxylic dianhydride (BTDA). Examples of the diamine include oxydianiline (ODA), paraphenylenediamine (PPD), and diaminobenzophenone (DAB). These acid dianhydrides and diamines are synthesized using a solvent such as dimethylacetamide (DMAC), N-methylpyrrolidone (NMP), dimethylformamide (DMF), dimethylsulfoxide (DMSO). The kind of polyimide precursor preferable for such carbonization and adjustment conditions are described in detail in Chemistry and Physics Carbon Vol. 26 Marcel Dekker, Inc. 1999 P. 245.

  As the “open cell thermosetting resin foam” of the present invention, polyurethane foam, rubber sponge, phenol resin foam, melamine resin foam, etc., and thermoplastics such as polyethylene resin foam, polypropylene resin foam, vinyl acetate resin foam, etc. Even a foam using an olefin resin can be used as long as the foam is crosslinked. These resin foams are preferably those that carbonize or disappear after firing. In particular, as a foam having a high rate of disappearing when fired, polyurethane foam, melamine resin foam, and olefin resin foam are preferable because air permeability and cell structure can be easily controlled. Among these, polyurethane foam and melamine resin foam are particularly preferable since they are thermosetting and do not dissolve or deform in the solvent in the polyimide precursor solution.

  Examples of the polyurethane foam include ether type, ester type, butadiene type, olefin type, castor oil type, and carbonate type depending on the type of polyol. Of these, ether type and ester type are preferable because they have a high degree of freedom in setting the cell diameter and foaming ratio of the foam. Furthermore, the ester type is preferable because it is not easily affected by the solvent used at the time of impregnation, the impregnation operation is easy to perform, and the disappearance ratio is high when baked.

  The melamine resin foam used here adds a foaming agent, acid catalyst, foam stabilizer, etc. to the reaction intermediate of melamine and formaldehyde, and heats it at a stretch using a microwave etc. Is an open-celled foam obtained by connecting the. Since this foam has a continuous foaming property, it has good impregnation properties when impregnated with a polyimide precursor solution and is difficult to swell in the solvent used in the solution, so impregnation work, drying work, firing work, etc. It is easy to handle and is easy to obtain the desired shape.

  Thus, by using a resin foam having high air permeability, the polyimide precursor solution can be sufficiently impregnated, and a carbon porous body having a three-dimensional network structure with a large amount of carbon per unit volume can be obtained. . However, in some cases, a resin foam having low air permeability may be used. For example, if urethane foam with extremely low air permeability is used for impregnation, the polyimide precursor solution may not be impregnated to the inside of the foam, and if this is fired, a carbon porous body floating in water with a hollow structure can be obtained. There is an advantage that carbon foams having various structures can be obtained by devising the resin foam as described above.

  What is important in the production of the carbon porous body of the present invention is that the dehydration imidation of the polyimide precursor resin is not more than the temperature at which the thermal decomposition of the thermosetting resin is promoted as described above with reference to FIG. Thus, it is necessary to carry out until imidization is completed. By treating in this way, it is possible to realize an impregnation state of polyimide in the resin foam without losing the three-dimensional network structure set by the resin foam.

  In order to impregnate a resin foam with the polyimide precursor resin, the foam body is immersed in a resin solution, compression and restoration are repeated, and the amount of impregnation is adjusted by the degree of compression. In addition, it is possible to easily impregnate the foam body by immersing the foam body in a resin solution and reducing the pressure. In this case, the foam body can be impregnated even if the foam body is not flexible. After impregnation, the solvent is removed by heating and a dehydration reaction is performed at a high temperature to obtain a foam / polyimide composite. As described above, the heating temperature in this imidization stage is preferably a temperature range in which imidization is possible and decomposition of the resin foam is not promoted, for example, 100 to 200 ° C. for polyurethane foam. The heat dehydration reaction is also preferably performed under reduced pressure. Moreover, a catalyst such as pyridine can be added, or a dehydrating agent can be used in combination.

  The foam-polyimide composite obtained by the imidization treatment as described above is subsequently subjected to a firing treatment to obtain a carbon porous body. The firing process is performed in an inert gas or in a vacuum. The baking temperature is 500 ° C. or higher. Preferably, the temperature is set to 1000 ° C. or higher, and high-temperature treatment may be performed up to about 3000 ° C. for graphitization. Furthermore, surface treatment can also be performed by activation with water vapor or carbon monoxide, or by treatment under oxidizing conditions. Furthermore, anatase-type titanium oxide is supported as a catalyst carrier on the obtained carbon porous material, and it becomes possible to effectively treat harmful substances by adsorption with carbon and a photocatalytic effect with titanium oxide. .

  Since the carbon porous body of the present invention is a three-dimensional structure having a large number of continuous fine pores made of carbon, it can be used for decomposing harmful gases such as catalyst carriers and filters, gas adsorbents, and heat insulating materials. It can be suitably used for radio wave absorbers, heat dissipation materials, and the like.

  Examples of the present invention will be described below. Examples described below are merely examples for suitably explaining the present invention, and do not limit the present invention in any way.

(Synthesis of polyimide precursor)
Pyromellitic anhydride purified by recrystallization and an equimolar amount of 4,4-diaminodiphenyl ether are dissolved in N, N′-dimethylacetamide, and this solution is passed through dry nitrogen in an environment of 20 ° C. for 3 hours. While continuing the reaction of the two components, a 10% solution (solution A) of polyamic acid was obtained.

(Open cell thermosetting resin foam used for impregnation)
(I) Urethane foam ES1
Using adipic acid-based polyester polyol obtained from adipic acid, diethylene glycol and a small amount of trimethylolpropane, diphenylmethane diisocyanate (MDI), water as a blowing agent, a small amount of catalyst, and a foam stabilizer, It is a urethane foam obtained by foaming. This urethane foam had a density of 0.13 g / cm ³ and an air permeability of 0.1 ml / cm ² / sec.
(Ii) Urethane foam ES2
Adipic acid-based polyester polyol and tolylene diisocyanate (TDI) similar to the urethane foam ES1, water as a blowing agent, a small amount of catalyst, and a foam stabilizer were synthesized and foamed. The cell membrane was removed from the urethane foam by an explosion method using hydrogen gas to obtain a highly breathable foam having a density of 0.06 g / cm ³ and an air permeability of 100 ml / cm ² / sec.
(Iii) Melamine foam MF
It is a melamine foam which is synthesized using methylolmelamine obtained from melamine and formaldehyde, a fluorine-based foaming agent, an acid catalyst and a foam stabilizer and foamed at a higher temperature. The density of this melamine foam was 0.008 g / cm ³ and the air permeability was 100 ml / cm ² / sec.
In addition, the measurement of the said air permeability was performed with respect to 10 mm of test piece thickness according to JISK6400 A method.

(Examples 1-3)
The impregnating resin foams ES1, ES2, and MF were immersed in the polyamic acid solution (solution A) and left for 1 hour. Thereafter, the three types of impregnated foams are taken out, dried at 60 ° C. for 10 hours, and then dehydrated and imidized at 200 ° C. for 20 hours, and the entire space inside and outside of the three-dimensional porous resin foam is filled with polyimide. Foam polyimide composite was obtained.

  Next, these foam-polyimide composites were baked in an argon atmosphere at 1000 ° C. for 1 hour to obtain three types of carbon foams (carbon porous bodies). The obtained carbon foam was completely similar to the foam used for impregnation and had air permeability, and the strength was extremely high as shown in [Table 1].

  FIG. 2 is a structure photograph taken with a scanning electron microscope (SEM) in which the impregnated foam (ES1), foam-polyimide composite, and carbon foam are arranged in this order from the left. From comparison of each SEM photograph, it can be seen that a carbon foam (carbon porous body) in which the cell state of the original resin foam (three-dimensional structure of each cell) is reflected fairly faithfully is obtained.

(Comparative Example 1)
A polyurethane foam was obtained from a bifunctional polyester polyol as an adipic acid-based polyester, MDI as an isocyanate, water as a blowing agent, other catalysts, and a foam stabilizer. The density of this polyurethane foam was 0.12 g / cm ³ and the air permeability was 0.1 ml / cm ² / sec.

  The polyurethane foam was impregnated with liquid A in the same manner as in Example 1, and drying and polyimide formation were attempted. However, the form of the foam-polyimide composite collapsed and decomposed during this process of polyimide formation. This was thought to be because the polyurethane foam was thermoplastic and could not form a composite body.

(Example 4)
Ether-based polyurethane foam was obtained from a polyether polyol having a molecular weight of 3000 obtained by adding propylene oxide to glycerin, toluene diisocyanate, water as a blowing agent, other catalysts, and a foam stabilizer. The density of this foam was 0.03 g / cm ³ and the air permeability was 30 ml / cm ² / sec. This resin foam was impregnated with the liquid A in the same manner as in Example 1. The obtained impregnated foam was dried, converted to polyimide at 180 ° C., and then fired at 1000 ° C. to obtain a carbon foam (carbon porous body). Obtained. The obtained carbon foam was slightly deformed in foam shape and weak in strength, but could be handled.

(Comparative Example 2)
A carbon foam was produced under the same conditions except that in the carbon foam production process of Example 4, the temperature of the polyimide formation was performed at 200 ° C. The resulting carbon foam was totally broken and ragd, and could not be handled.

(Example 5)
The carbon foam of Example 1 was treated in air at 400 ° C. for 1 hour to grow its pores. As shown in the graph of FIG. 3, the change in weight of the carbon foam after the pore growth treatment is measured by changing the weight when the temperature is changed between 200 ° C. and room temperature in an air atmosphere. As a result, it was found that the moisture adsorption / desorption response was extremely fast and reversible. That is, it was confirmed that the carbon foam (carbon porous body) of the present invention has high adsorptivity.

(Example 6)
The carbon foam of Example 1 was treated at 3000 ° C. for 20 minutes in an argon atmosphere. The grain size of the crystal grains constituting the carbon foam (carbon porous body) after the heat treatment is 30 nm, each crystal grain has a (002) lattice plane, and the plane spacing d002 is 0.336 nm. It was found by measurement. That is, it was confirmed that each crystal grain has a graphite structure. Therefore, the porous carbon body of this example can be suitably applied to uses that require electrical conductivity and uses that require heat resistance.

(Example 7)
A urethane foam having the same composition as the resin foam for impregnation ES1 described above, but impregnated with a liquid A into a resin foam with extremely low air permeability, fired in the same manner as in Example 1, and a carbon porous body floating in water. Obtained. Since this carbon porous body has a very low air permeability of the resin foam as the mold material, the liquid A can only penetrate into the surface and the shallow part from the surface, and as a result, a hollow carbon porous body is obtained. Was guessed. The dimension of this carbon porous body was 10 × 10 × 2 mm.
This carbon porous body is immersed in an aqueous solution (0.1 mol / L) of oxysulfate titanate (TiOSO ₄ ) and hydrothermally treated in a stainless steel container at 180 ° C. for 5 hours, thereby anatase. 3.2% of microcrystals were supported. FIG. 4 shows a structure photograph of this “carbon porous body supporting titanium oxide” by a scanning electron microscope. The anatase-supporting porous material was placed in an aqueous solution of methylene blue (2.94 × 10 ⁻⁵ mol / L), and the decomposition behavior under ultraviolet (10 W power) irradiation was followed. Changes in methylene blue concentration were followed by changes in absorbance at 650 nm. The result is shown in FIG. As can be seen from the figure, the methylene blue concentration hardly changes in the dark, and the adsorption is very small. Then, it can be seen that the absorbance of methylene blue is drastically decreased by irradiating ultraviolet rays, and the photolysis has progressed. Thus, it is understood that the carbon porous body of the present example can be applied to adsorption and decomposition of harmful substances in water.

  As described above, since the carbon porous body according to the present invention is a three-dimensional structure having a large number of continuous fine pores made of carbon, it can be used for decomposing harmful gases such as catalyst carriers and filters, It can be suitably used as a gas adsorbent, a heat insulating material, a radio wave absorber, a heat dissipation material, a use requiring conductivity, a use requiring heat resistance, and other various industrial materials.

It is a figure which shows the graph which plotted the thermogravimetric analysis result of the material substance used in order to obtain the carbon porous body of this invention. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a diagram for explaining Examples 1 to 3 of the present invention, each of a resin foam, a composite in which the resin foam is impregnated with polyimide, and a scanning electron microscope of a carbon porous body obtained by carbonizing the composite. It is the figure which arranged and showed the organization photograph by. It is a figure which shows the graph which plotted the result of having measured the water absorption and dehydration response characteristic of the carbon porous body obtained in Example 5 of this invention. It is the scanning electron micrograph of the carbon porous body which carry | supported the titanium oxide (anatase) obtained in Example 7 of this invention, and was the figure displayed side by side what was copied by three kinds of magnifications. It is a figure showing the graph which shows the adsorption | suction and decomposition | disassembly characteristic of methylene blue by the titanium oxide carrying | support carbon porous body obtained in Example 7 of this invention.

Claims (7)

A porous carbon material obtained by carbonizing a foam-polyimide composite in which a polyimide resin is filled in an open-cell thermosetting resin foam.   2. The porous carbon body according to claim 1, wherein the polyimide resin is obtained by polyimidizing a polyimide precursor resin impregnated in the thermosetting resin foam. 3.   The porous carbon body according to claim 2, wherein the polyimide precursor resin is a polyamic acid obtained by a reaction between an aromatic acid anhydride and an aromatic diamine.   An open-celled thermosetting resin foam is impregnated with a polyimide precursor resin, the impregnated resin is dehydrated and imidized, and the polyimide resin is continuously filled in the inner and outer spaces of the thermosetting resin foam. A method for producing a porous carbon material, wherein the carbon porous material is obtained by carbonization.   The dehydration imidation of the polyimide precursor resin is performed at a temperature below the temperature at which thermal decomposition of the thermosetting resin is promoted until imidization is completed, and then the process proceeds to carbonization treatment of the obtained polyimide resin. The manufacturing method of the carbon porous body of Claim 4 characterized by the above-mentioned.   6. The method for producing a porous carbon body according to claim 4, wherein a polyamic acid obtained by a reaction between an aromatic acid anhydride and an aromatic diamine is used as the polyimide precursor resin.   The method for producing a porous carbon body according to any one of claims 4 to 6, wherein a melamine resin foam or a polyester polyurethane foam is used as the thermosetting resin foam.

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