JP2020007694A - Functional porous material and method for production thereof - Google Patents

Abstract

To provide a functional porous material capable of expressing functionality for a long period even when be exposed to friction and the like and also capable of restraining a direct contact of a functional chemical substance with skin or the like even when contacting human bodies, and to provide a method for production of the above material.SOLUTION: A method for production of a functional porous material includes: a process of impregnating a reaction material solution in the hole of a porous material 110; a process of immersing the impregnated porous material with the reaction material solution in a solvent noncompatible with the reaction material solution to shift the solution existing on the surface of the porous material and/or in the vicinity thereof to the inside of the hole of the porous material or the inside of a material structure; and a process of working a chemical reaction to the reaction material solution shifted to the inside of the hole of the porous material or into the material structure.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a functional porous material and a method for producing the same.

As a functional porous material, a functional fiber having a fiber surface having conductivity or antibacterial property is known.
For example, a metal-coated fiber in which a metal plating film is provided on an organic fiber substrate made of a multifilament is disclosed (see Patent Document 1). The metal-coated fiber is a multifilament in which a metal plating film is formed on each monofilament (single yarn).
Also, a method for producing a conductive cellulosic fiber material is described (see Patent Document 2). In the production method, first, a cellulosic fiber material is swollen with an aqueous solution containing an alkali metal hydroxide (swelling step). Next, the outer periphery and the inside of the cellulosic fiber material are impregnated with copper ions with an aqueous solution in which a compound containing copper ions is dissolved (impregnation step). Then, the copper ions impregnated in the cellulosic fiber material are sulfided and reduced by an aqueous solution in which a compound containing a sulfide ion is dissolved, so that fine particles made of copper sulfide are generated on the outer periphery and inside of the cellulosic fiber material (sulfide). Reduction step). The copper sulfide imparts conductivity to the cellulosic fiber material.
Further, as an antibacterial fiber, a fiber in which an antibacterial deodorant containing a metal phthalocyanine derivative and a metal ammine complex as active ingredients is supported on the fiber is disclosed (see Patent Document 3).

JP 2014-055388 A JP 2014-167187 A JP 2012-095733 A

Many of the conventional conductive fibers are coated with metal on the surface of the fibers (see Patent Documents 1 and 2), so that performance is deteriorated due to peeling due to friction, abrasion, and the like. In addition, antibacterial fibers (see Patent Document 3) also have a short antibacterial life because the antibacterial functional material attached to the surface is easily detached by friction or washing. As described above, it is difficult for the existing functional porous material to maintain its functionality for a long period of time.
In addition, when the functional porous material is used in contact with a human body or the like, a chemical substance which bears functionality may directly contact the human body or the like, which may cause a skin disease or the like.

  INDUSTRIAL APPLICABILITY The present invention can exhibit functionality for a long time even when exposed to friction or the like, and can suppress direct contact of a functional chemical substance to skin or the like even when it comes into contact with a human body or the like. It is an object to provide a functional porous material and a method for producing the same.

The present inventors have conducted intensive studies in view of the above problems. As a result, the reaction raw material solution penetrates into the pores of the porous material, is immersed in a solvent that is incompatible with the reaction raw material solution, and does not penetrate to the inside of the pore, but at or near the surface of the porous material It has been found that the reaction raw material solution remaining in the hole can be transferred to the inside of the pore. Furthermore, it has been found that by causing a chemical reaction in the reaction raw material solution in this state, a functional chemical substance as a reaction product can be selectively disposed inside the pores of the porous material.
The present invention has been further studied based on these findings, and has been completed.

That is, the above object of the present invention is solved by the following means.
[1]
A step of penetrating the reaction raw material solution into the pores of the porous material,
The porous material impregnated with the reaction material solution is immersed in a solvent that is incompatible with the reaction material solution, and the reaction material solution existing on the surface of the porous material and / or in the vicinity thereof is removed. A step of moving the inside of the pores and the material structure of the porous material,
Causing a chemical reaction to occur in the reaction raw material solution transferred into the inside of the pores or the material structure of the porous material.
[2]
The method for producing a functional porous material according to [1], wherein the chemical reaction is caused by heating.
[3]
The method for producing a functional porous material according to [2], wherein the heating is heating by microwave irradiation.
[4]
The method for producing a functional porous material according to [3], wherein the microwave irradiation is a single-mode microwave irradiation.
[5]
The reaction raw material solution contains a metal precursor,
The method for producing a functional porous material according to any one of [1] to [4], wherein the chemical reaction is a reaction for depositing a metal from the metal precursor.
[6]
The reaction raw material solution contains an alkoxysilane compound,
The method for producing a functional porous material according to any one of [1] to [4], wherein the chemical reaction is a reaction that produces silica by hydrolysis of the alkoxysilane compound and subsequent condensation polymerization.
[7]
The method for producing a functional porous material according to any one of [1] to [4], wherein the chemical reaction is crystallization or precipitation of a chemical substance in the reaction raw material solution.
[8]
The reaction raw material solution contains a silica source, an alkali source and water,
Or, comprising a metal source capable of replacing silicon in addition to the silica source, the alkali source and the water,
The method for producing a functional porous material according to any one of [1] to [4], wherein the chemical reaction is a reaction that generates zeolite.
[9]
The reaction raw material solution contains a polyamic acid,
The method for producing a functional porous material according to any one of [1] to [4], wherein the chemical reaction is a reaction that generates a polyimide by a dehydration and ring closure reaction of the polyamic acid.
[10]
Any of [1] to [9], wherein the porous material is composed of a plant fiber, an animal fiber, a chemical fiber, a hollow fiber, or a hollow particle, or is composed of a composite material composed of two or more of these. A method for producing a functional porous material according to the above item.
[11]
The method for producing a functional porous material according to [10], wherein the plant fiber is cotton.
[12]
A functional porous material that contains a functional chemical substance in the pores of the porous material.
[13]
The functional porous material according to [12], wherein the functional chemical substance includes a metal.
[14]
The functional porous material according to [13], which has an antibacterial and / or antiviral function by the metal.
[15]
The functional porous material according to [13] or [14], wherein the functional porous material exhibits conductivity by the metal.
[16]
The porous material is a composite material containing a cotton material and silicon, and the silicon concentration in the inside and / or the cotton material tissue is higher than the outer surface of the cotton material [12] to [15]. Functional porous material.
[17]
The porous material according to any one of [12] to [15], wherein the porous material is a porous hollow fiber having carbon as a structure, and zeolite is held in a hollow portion and / or an inner surface of the porous hollow fiber. Functional porous material.

  The functional porous material of the present invention can exhibit functionality for a long period of time even when exposed to friction or the like, and also suppresses direct contact of functional chemicals to skin etc. even when it comes into contact with the human body can do. According to the method for producing a functional porous material of the present invention, the functional porous material of the present invention having the above characteristics can be obtained.

It is a cotton fiber used for a preferred embodiment of the method for producing a functional porous material of the present invention, and is a drawing substitute synthetic photograph showing a perspective view of a state in which each layer of the cotton fiber is partially peeled off. FIG. 2 is a partial cross-sectional perspective view schematically showing cotton fibers (two cotton fibers shown in FIG. 1) used in a preferred embodiment of the method for producing a functional porous material of the present invention. FIG. 3 is a partial cross-sectional perspective view schematically showing a permeation step of permeating a reaction fiber solution into the cotton fibers shown in FIG. 2 in a preferred embodiment of the method for producing a functional porous material of the present invention. FIG. 3 is a partial cross-sectional perspective view schematically showing a transfer step in which a reaction raw material solution is further transferred to the inside of the cotton fiber shown in FIG. 3 in a preferred embodiment of the method for producing a functional porous material of the present invention. It is. It is the partial cross-sectional perspective view which showed typically the heating and chemical reaction process of one preferable embodiment of the manufacturing method of the functional porous material of this invention. It is a cotton substitute used in a preferred embodiment of the method for producing a functional porous material of the present invention, and is a drawing substitute composite photograph showing a perspective view in a state where each layer of the cotton fiber is partially peeled off. (A) is a drawing substitute photograph taken by a scanning electron microscope (SEM) of a cross section of a cotton cloth of a sample on which silver was precipitated in Example 1. (B) is a graph showing the result of analyzing the composition of the cross section of the cotton cloth in the direction of arrow A in (A) using energy dispersive X-ray spectroscopy. The vertical axis represents the silver component and the carbon component. The spectrum intensity (Intensity) is shown, and the position (Point number) is shown on the horizontal axis. (A) is a drawing-substitute photograph taken with a scanning electron microscope of a cotton cloth of a sample on which silver was precipitated in Example 2. (B) is a graph showing the result of analyzing the composition of the cross section of the cotton cloth in the direction of arrow B in (A) using energy dispersive X-ray spectroscopy, and the vertical axis represents the silver component and the carbon component. The spectrum intensity (Intensity) is shown, and the position (Point number) is shown on the horizontal axis. (A) is a drawing-substituting photograph taken by a scanning electron microscope of a cross section of a cotton cloth of a sample in which the amorphous silica of Example 3 was precipitated. (B) is a graph showing the results of a composition analysis of the cross section of the cotton cloth in the direction of arrow A in (A) using energy dispersive X-ray spectroscopy, with the ordinate indicating the silicon component and the carbon component. Are shown, and the abscissa indicates the position (Position). (A) is a drawing-substitute photograph taken by a scanning electron microscope (SEM) of a cross section of a Kapok fiber used as a sample of Example 4. (B) is a drawing-substituting photograph taken by a scanning electron microscope of a cross section of a Kapok fiber of a sample in which the amorphous silica of Example 4 was precipitated. FIG. 10 (C) is a graph showing the results of a composition analysis of the cross section of the Kapok fiber in the direction of arrow A in FIG. 10 (B) using energy dispersive X-ray spectroscopy. The spectral intensity (Intensity) of the component and the carbon component are shown, and the position (Position) is shown on the horizontal axis. (A) is a drawing substitute photograph in which a cross section of a porous hollow fiber (MKC. MXJ (600L) manufactured by Toray Industries, Inc.) of a sample in which silica of Example 5 is precipitated is taken with a scanning electron microscope. . (B) is a graph showing the results of a composition analysis of the cross section of the fiber in the direction of arrow A in (A) using energy dispersive X-ray spectroscopy. Are shown, and the abscissa indicates the position (Position). (A) shows a cross section of a porous hollow fiber (manufactured by Sumitomo Electric Industries, Ltd., trade name: Poeflon (registered trademark) tube) of a sample in which zeolite is precipitated in Example 6, using a scanning electron microscope. It is a drawing substitute photograph taken. (B) shows the distribution state of the oxygen, sodium, silicon, and aluminum components obtained by analyzing the composition of the sample of Example 6 using energy dispersive X-ray spectroscopy and was photographed with a scanning electron microscope. It is a drawing substitute photograph. (C) is a drawing showing the diffraction pattern obtained by the X-ray diffraction measurement, and is a drawing showing the X-ray diffraction pattern of the zeolite in Example 6, wherein the vertical axis represents the diffraction X-ray intensity (Intensity). And the abscissa indicates the diffraction angle (2 Theta degree). 13 is a drawing-substituting photograph of a cross section of a porous hollow fiber (manufactured by Sumitomo Electric Industries, Ltd., trade name: Poeflon (registered trademark) tube) of a sample obtained by depositing the polyimide of Example 7 inside using a scanning electron microscope. . A drawing substitute photograph of a cross section of a porous hollow fiber (manufactured by Sumitomo Electric Industries, Ltd., trade name: Poreflon (registered trademark) tube) of a sample in which the hinokitiol crystal of Example 8 was precipitated was taken with a scanning electron microscope. is there. A drawing-substitute photograph taken by a scanning electron microscope of a cross section of a porous hollow fiber (manufactured by Sumitomo Electric Industries, Ltd., trade name: Poreflon (registered trademark) tube) of a sample in which the alum crystal of Example 9 was precipitated. is there. (A) is a drawing substitute photograph in which a cross section of a natural fiber (bamboo) of a sample in which the alum crystal of Example 10 was precipitated was taken with a scanning electron microscope. (B) is a drawing substitute for a photograph taken by a scanning electron microscope of the distribution state of carbon, sulfur and aluminum components obtained by analyzing the composition of the sample of Example 10 using energy dispersive X-ray spectroscopy. It is a photograph. (A) is a drawing substitute photograph in which a cross section of a natural fiber (cedar) of a sample in which the alum crystal of Example 11 was precipitated was taken with a scanning electron microscope. (B) Drawing substitutes the drawing which image | photographed the distribution state of the carbon, sulfur, and aluminum component obtained by composition analysis of the sample of Example 11 using the energy dispersive X-ray spectroscopy with a scanning electron microscope. It is a photograph. FIG. 21 is a schematic sectional view showing an example of a preferred configuration of a resonator-type microwave heating device used for heating in Example 12. It is the graph which showed the result of having performed the composition analysis of the cross section of the cotton fabric produced by Example 12 using the energy dispersive X-ray spectroscopy, and the vertical axis | shaft showed the spectral intensity (Intensity) of a silver component and a carbon component, The position (Position) is shown on the horizontal axis.

[Production method of functional porous material]
Hereinafter, a preferred embodiment of the method for producing a functional porous material of the present invention will be described with reference to the drawings.

  FIG. 1 shows a cotton fiber 111 as an example of a porous material 110 as a raw material. The cotton fibers 111 are formed of slender (for example, about 30 mm long) shaped cotton cells containing a large amount of cellulose (for example, 95% by mass or more). The cotton fiber 111 has, from the outside, a primary cell wall 115 having a cuticle layer 112, a network layer 113, and a winding layer 114, a secondary cell wall 116, and a lumen 117. Then, the primary cell wall 115 has a multilayer structure in which the secondary cell wall 116 is covered. Primary cell wall 115 and secondary cell wall 116 are aggregates of microfibrils. Microfibrils are formed by bundling a plurality of nanofibers (cellulose molecules). In the cotton fibers 111, the gaps between the microfibrils form pores as a porous material.

As the porous material, in addition to the above-mentioned cotton fibers, those composed of various plant fibers, animal fibers, mineral fibers, or chemical fibers can be used. When these fibers are single fibers, a fiber bundle (for example, yarn) obtained by bundling the short fibers can be used as the porous material. In this case, the gap between the single fibers becomes a hole of the porous material.
Plant fibers include various plant-derived fibers. As an example, cotton, linen, basho, kabok (commonly called panya cotton) and the like can be mentioned. Animal fibers include various animal-derived fibers. Examples include animal hair such as wool, cashmere, angora, alpaca, silk, feathers, and the like. As mineral fibers, asbestos, rock wool and the like can be mentioned. The chemical fibers include regenerated cellulose fibers, semi-synthetic fibers, synthetic fibers, high-performance fibers, and inorganic fibers. Examples of the regenerated cellulose fibers include rayon, cupra, lyocell, and the like. Examples of the semi-synthetic fibers include acetate and triacetate. Examples of the synthetic fibers include polyamide-based fibers and polyester-based fibers. Examples of the high-performance fiber include aramid fiber and polyimide fiber. Examples of the inorganic fibers include glass fibers and carbon fibers.
The chemical fiber may be a hollow fiber (a nylon hollow fiber, a polyester hollow fiber, or the like).
The porous material may be hollow particles (hollow polymethyl methacrylate particles, hollow silica particles, etc.) in addition to the above-mentioned fibers.
In addition, a microporous material, a mesoporous material, a macroporous material, or the like can be used as the porous material. Examples of the microporous material include activated carbon, zeolite, and silica gel. Examples of the mesoporous material include silicon dioxide (mesoporous silica) and aluminum oxide, and oxides such as niobium, tantalum, titanium, zirconium, cerium, and tin. Examples of the macroporous material include pumice and urethane sponge. According to the definition of IUPAC (International Union of Pure and Applied Chemistry), porous materials are classified by pore size distribution. Microporous materials having a pore size of less than 2 nm, mesoporous materials having a pore size of 2 to 50 nm, and macroporous materials having a pore size larger than 50 nm. It is prescribed. Pore size distribution, gas adsorption method (eg, _{N 2} adsorption -BJH (Barrett, Joyner, Hallender) method, _{N 2} adsorption -DFT (Density Functional Theory) method, etc.), can be determined by mercury intrusion method.
Examples of the porous material include a composite material containing at least a porous material. Examples of the composite material include a composite material containing a cotton material and silicon. For example, a form having a higher silicon concentration inside and / or in the tissue of the cotton material than the outer surface of the cotton material can be given. In addition, this composite material can also be used as it is as a functional porous material described later.
In addition, examples of the porous material include a porous hollow fiber having carbon as a structure. For example, a form in which zeolite is held in the hollow portion and / or the inner surface of the porous hollow fiber can be used as a functional porous material described later.

Next, a preferred example of the method for producing a porous material of the present invention will be described. FIGS. 2 to 5 schematically show a case where the cotton fiber 111 shown in FIG. 1 is used as the porous material 110. 2 and 3 schematically show two cotton fibers, and FIGS. 4 and 5 schematically show one cotton fiber.
First, as shown in FIG. 2, the reaction raw material solution is made to permeate the cotton fiber 111 (penetration step). Specifically, the cotton fiber 111 is immersed in a reaction material solution (not shown) placed in a container (not shown), and the reaction material solution is permeated into the cotton fiber 111. This infiltration step can be performed, for example, at a liquid temperature of 15 ° C. to 30 ° C. and atmospheric pressure (for example, atmospheric pressure on flat ground). As a result, as shown in FIG. 3, the capillary is formed in the hole of the cotton fiber 111 near the surface and / or in the cotton fiber structure (that is, in the hole of the cotton fiber 111 and / or in the cotton fiber structure). The reaction raw material solution permeates due to the phenomenon. The surface refers to the outermost outer surface 111S of the cotton fiber 111. The inside of the hole refers to the inside of the gap (not shown) between the microfibrils of the cotton fiber 111. In the drawing, the darker portion of the cross section of the cotton fiber 111 indicates the permeation area 121 of the reaction material solution. The permeation area 121 is distributed from the outer surface 111S of the cotton fiber 111 toward the inside. In this state, a larger amount of the reaction raw material solution permeates the surface side (the cuticle layer 112 side) than the radial bore 117 side of the cotton fiber 111. The permeation step may be performed under reduced pressure in order to promote the permeation of the reaction solution. For example, when the pressure is set at 0.01 to 1 atm, the discharge of the air retained in the cotton fiber / between the fibers is promoted, and the retained amount of the reaction raw material solution can be increased in that portion.
Here, since the cotton fiber has a polarity and is easily adapted to a polar solvent, it is preferable to use water, a water-soluble organic solvent, or a mixture thereof as a medium of the reaction raw material solution. When the porous material has relatively low polarity such as synthetic fiber and is hardly compatible with water, it is preferable to use a more hydrophobic solvent as a medium for the reaction raw material solution.

The reaction raw material solution can contain, for example, a metal precursor (metal salt). In this case, the reaction product can be a deposited metal.
As an example, when the metal precursor is a silver salt, a solution obtained by dissolving silver nitrate in a solvent (for example, alcohol or a mixed solvent of alcohol and water) exhibiting a reducing action on metal can be used as a reaction raw material solution. . Examples of the alcohol include methanol, ethanol, ethylene glycol, diethylene glycol, propylene glycol, tetraethylene glycol, glycerol, benzyl alcohol, dipropylene glycol and the like. Further, the metal precursor is not limited to a silver salt, and various metal salts such as copper, platinum, palladium, ruthenium, nickel, cobalt, iron, aluminum, titanium, gold, chromium, and zinc can be used.
As the combination of the reaction raw material solution and the reaction product, in addition to the above-described metal precursor and precipitated metal, for example, a combination of a metal hydroxide and an oxide, a combination of a metal alkoxide and a metal oxide, and a combination of an organic monomer and a high Examples include a combination of molecular polymers, a combination of a ligand (ligand) and a metal complex, and the like.

If necessary, an excess amount of the reaction material solution exceeding the amount of the reaction material solution that the cotton fiber 111 can hold is removed from the cotton fiber 111 in which the reaction material solution has penetrated. For example, excess reaction raw material solution can be removed by squeezing lightly. Next, as shown in FIG. 4, the cotton fiber 111 is immersed in a solvent 132 incompatible with the reaction raw material solution contained in the container 131. Then, it is preferable to cover the lid 133 so as to seal the inside of the container 131. To squeeze lightly means to squeeze the liquid so that it does not drip.
The fact that the solvent 132 is incompatible with the reaction raw material solution means that the solvent 132 is not substantially compatible with the solvent of the reaction raw material solution. That is, the relationship means that both solvents are not mixed at 25 ° C. and exist in independent phases. In this case, as long as the effects of the present invention are not impaired, the two solvents may not be completely phase-separated near the interface between the two solvents, and may form a region where they are mixed with each other. More specifically, the substantially incompatible relationship means that the solubility of the solvent of the reaction raw material solution in the solvent 132 at 25 ° C. is preferably 10 g / 100 g or less, more preferably 5 g / 100 g or less, and 1 g / 100 g or less. 100 g or less is more preferable.
For example, when cotton fiber is used as the porous material and water, a water-soluble organic solvent, or a mixture thereof (that is, a polar solvent (hydrophilic solvent)) is used as the reaction raw material solution, the solvent 132 is non-polar. A solvent (hydrophobic solvent) is used. For example, as the solvent 132, dodecane, decane, hexane, toluene, benzene, naphthalene, florinate (trade name), hydrofluoroolefin, silicone oil, linear alkanes, cyclic alkanes, linear unsaturated hydrocarbons, cyclic Unsaturated hydrocarbons, aromatics, fluorocarbons, mineral oils, vegetable oils and the like can be used. The temperature of the solvent 132 is not particularly limited, and is appropriately set according to the purpose. For example, the temperature can be set to -100 ° C to 300 ° C.

  In the embodiment of FIG. 4, the reaction raw material solution that is incompatible with the solvent 132 impregnated in the cotton fiber 111 passes through the gap (in the hole) between the microfibrils from the outer surface 111S side of the cotton fiber 111 due to the liquid pressure of the solvent 132. Further, the inside of the cotton fiber 111 and the inside of the cotton fiber (material) tissue, that is, the inside of the cotton fiber 111 and / or the inside of the cotton fiber (material) tissue are transferred (transition step). When the capillary force further acts, the reaction raw material solution that has penetrated into the cotton fibers 111 moves further into the interior through the gaps between the microfibrils. Therefore, the permeation region 121 of the reaction raw material solution moves from the outer surface 111S of the cotton fiber 111 toward the inside of the cotton fiber 111. As a result, a large amount of the reaction raw material solution exists from the outer surface 111S side of the cotton fiber 111 toward the inside of the cotton fiber 111.

  In the embodiment shown in FIG. 4, the pressure P is applied to the solvent 132 in which the cotton fibers 111 are immersed. As the pressure P, gas pressure or liquid pressure may be applied from outside the container. Further, a pressurizing cylinder may be provided in the container itself, and power may be applied to the cylinder to pressurize the cylinder. Alternatively, the container may be sealed, and the solution may be heated so that the solution is pressurized by volume expansion or generation of vapor pressure. Alternatively, it is also possible to add a solvent having a boiling point lower than that of the main solvent in addition to the main solvent, vaporize the mixture by heating, and pressurize the mixture. When a pressure higher than the atmospheric pressure is applied to the surface of the solvent 132, the reaction raw material solution passes through the gaps (in the holes) between the microfibrils of the cotton fibers 111 and is further pushed into the interior. As a result, the reaction raw material solution is transferred from the surface of the cotton fiber 111 to the inside by a stronger pressure, and the reaction raw material solution can be transferred to the inner surface of the lumen 117 of the cotton fiber 111 or the vicinity thereof. . In the production method of the present invention, the chemical reaction may be started after the pressure is applied before the chemical reaction is started, or the pressure may be applied while the chemical reaction occurs. The magnitude of the pressure can be appropriately set according to the type of the porous material and the like. For example, the pressure can be about 1.05 to 20 atm, or about 1.1 to 10 atm.

  Next, as shown in FIG. 5, a chemical reaction is caused in the reaction material solution therein by heating the permeation region 121 of the reaction material solution impregnated in the cotton fiber 111 to a predetermined reaction temperature. When the reaction raw material solution contains the above-described metal salt and a reducing agent, the metal salt can be reduced by heating to precipitate a metal.

As an example of the heating method, the microwave MW is applied to the cotton fibers 111 in the solvent 132 contained in the container 131. The permeation region 121 of the reaction raw material solution impregnated in the cotton fiber 111 is controlled to be heated to a predetermined reaction temperature, and a metal precursor (not shown) therein is heated. The predetermined reaction temperature is appropriately set depending on the type of the target reaction. That is, the temperature is preferably equal to or higher than the temperature at which the target reaction occurs, and lower than the boiling point of the solvent 132. The container 131 is made of, for example, polytetrafluoroethylene (for example, Teflon (registered trademark)), quartz, ceramic, aluminum oxide (alumina), polyetheretherketone (PEEK), which hardly absorbs the microwave MW. ), And acrylic (trade name) resin. For the microwave MW, generally, an S band having a microwave frequency of 2 to 4 GHz can be used. Alternatively, 900 to 930 MHz or 5.725 to 5.875 GHz can be used. Also, microwaves of other frequencies may be used.
Irradiation with the microwave MW as described above is preferable in that silver nitrate of the reaction raw material solution directly generates heat, so that heating can be performed in a short time and temperature unevenness due to heat conduction can be reduced. Further, it is preferable because it can be heated in a non-contact manner and can selectively heat silver nitrate having good absorption of microwave MW.
Microwave irradiation may be multi-mode or single-mode, and it is preferable to employ single-mode microwave irradiation from the viewpoint of efficiently and uniformly heating a target portion.
Note that heating is not limited to microwave heating. For example, light heating may be used. Heating by other heating means may be used. In addition, heating may be performed selectively on the reaction raw material solution, or cotton fiber or a solvent may be heated to indirectly heat the reaction raw material solution.
Further, reaction promotion by means other than heating means can be used. For example, in photopolymerization, irradiation with ultraviolet light or visible light may be used. Further, reaction promotion by irradiation with ultrasonic waves can also be used. Alternatively, pressure such as a shock wave can be used to start the reaction. Alternatively, in the case of a gentle reaction, simply standing still is an effective reaction control method. In a reaction promoted at a low temperature, such as crystallization or precipitation, maintaining a low temperature environment is also an effective reaction control method.

  By the heating, a chemical reaction is selectively caused in the permeation region 121 in the cotton fiber 111 to generate a chemical substance. For example, a metal is deposited from a metal precursor.

  After that, the cotton fiber 111 is taken out from the solvent 132, washed if necessary by dipping it in a desired solvent, and then dried to obtain a desired functional porous material. The washing is preferably performed by dipping in ethanol and washing with an ultrasonic washing machine. Drying can be performed by natural drying in the air or heating and drying in an electric furnace. Alternatively, it is also effective to dry by contacting with air or nitrogen. The washing may be performed by immersion in a liquid such as water or alcohol, or may be performed by contact with running water or a liquid in a flowing state.

  The cotton fiber 111 produced as described above has a functional chemical substance (metal or the like) between the microfibrils 118 of the secondary cell wall 116, as shown in FIG.

In the above embodiment, the description has been mainly focused on the case where the hydrophilic cotton fiber 111 is used as the porous material, but the porous material is not limited to the cotton fiber as described above.
That is, using a hydrophobic reaction raw material solution as the reaction raw material solution, the reaction raw material solution is permeated into the pores of the hydrophobic porous material, and the porous raw material is incompatible with the reaction raw material solution. By immersing the raw material in a soluble hydrophilic solvent, the reaction raw material solution can be transferred further inside the pores of the porous material. Then, by causing a chemical reaction in the reaction raw material solution transferred to the inside of the porous material, a chemical substance (for example, a metal) is generated more inside the porous material than on the surface of the porous material, like the cotton fiber. Can be.
The chemical reaction can be performed by heating as described above, but is not limited to heating. Depending on the type of the reaction raw material, light (radiation) irradiation, ultrasonic irradiation, shock wave irradiation, standing, cooling, etc. Means can also be used.
In the present invention, the term chemical reaction is used in a broad sense. That is, in addition to a chemical substance reacting and changing to another chemical substance, a change in the state of a chemical substance is also included in the chemical reaction in the present invention. For example, crystallization or precipitation that does not change the chemical substance itself is included in the chemical reaction in the present invention. Preferred examples of the chemical reaction to which the method for producing a functional porous material of the present invention is applied include an oxidation reaction, a reduction reaction, a polymerization reaction, a condensation reaction, a substitution reaction crystallization, and precipitation.
As a specific example, there can be mentioned a form in which the reaction raw material solution contains a metal precursor and the chemical reaction is a reaction for precipitating a metal from the metal precursor as described above.
The reaction raw material solution may include an alkoxysilane compound (preferably tetraalkoxysilane), and the chemical reaction may be a reaction that produces silica by hydrolysis of the alkoxysilane compound and subsequent condensation polymerization. .
Further, there may be mentioned a form in which the chemical reaction is crystallization or precipitation of a chemical substance in the reaction raw material solution.
Further, a form in which the reaction raw material solution contains a silica source, an alkali source and water, or a metal source capable of replacing silicon in addition to the silica source, the alkali source and water, and the chemical reaction is a reaction that generates zeolite. Can be mentioned. Examples of the silica source include colloidal silica and tetraethoxysilane (TEOS). Examples of the alkali source include an alkaline earth metal cation and an alkyl ammonium cation. Examples of the metal source capable of replacing silicon include alumina and titanium.
Further, there may be mentioned a form in which the reaction raw material solution contains a polyamic acid, and the chemical reaction is a reaction that produces a polyimide by a dehydration and ring closure reaction of the polyamic acid.

[Functional porous material]
The functional porous material of the present invention is a porous material as described above, which contains a functional chemical substance in its pores. The term “encapsulation” means that a larger amount of the functional chemical substance is present in the pores on the inner side than the outer surface of the porous material. The functional porous material of the present invention, by including a functional chemical substance in the pores, can exhibit functionality for a long time even if the functional porous material is exposed to friction or the like, Even when the functional chemical substance is brought into contact with the human body or the like, direct contact of the functional chemical substance with the skin or the like can be prevented or suppressed.
Functional chemicals are conductive, antibacterial, antiviral, antifungal, anti-mite, biological repellent, humidity-controlling, heat-retaining, heat-generating, heat-absorbing, cooling, deodorizing, and deodorizing. Function, fragrance, harmful substance capture function, harmful substance detoxification function, chemical sustained release function, coloring function, luminescence function, ultraviolet shielding function, electromagnetic wave shielding function, insulation function, dielectric, magnetism, electromagnetic wave reflection function, ultraviolet rays Visible light / infrared absorption function, ultraviolet / visible light / infrared reflection function, soundproof function, heat shield function, flameproof function, fireproof function, flame retardant, antifouling function, antistatic function, antistatic function, water repellent function, It preferably has at least one of a hydrophilic function, a shape memory function, a morphological stabilizing function, a shock absorbing function, an anti-cut wound function, and a sedative action. Specific examples include various metals such as silver, copper, platinum, palladium, tin, nickel, cobalt, and gold, or compounds containing those metals. In addition, conductive polymers, zeolites, layered compounds, clay, silica gel, inorganic crystals, organic crystals, amorphous particles, microcapsules, nanopore materials, semiconductor materials, dielectric materials, magnetic materials, piezoelectric materials, thermoelectric materials, photocatalysts , Luminescent material, Fluorescent material, Luminescent material, Titanium oxide, Water retention material, Water absorbing polymer, Activated carbon, Flame retardant, Fire extinguisher, Insulation material, Heat storage material, Heat retention fragrance, Impact absorber, Pigment, Ink, Sedative, Spirit Examples include stabilizers, pharmaceuticals, antibacterial materials, antiviral materials, and antifungal materials.

  Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention should not be construed as being limited thereto.

  A cotton cloth containing silver inside the fiber was manufactured by using the above-described synthesis method, and the details will be described.

[Example 1]
In Example 1, a sample was prepared as follows. A commercially available white cotton cloth (5 cm (length) × 17 cm (width) × 0.25 mm (thickness), weight 300 g / m ² ) was used as a measurement sample. The thickness of the cotton cloth is a thickness measured when a pressure of 100 g / cm ² is applied to the measurement area.
The measurement sample was immersed for 5 minutes in an ethylene glycol solution (3 ml) in which 1 M of silver nitrate as a reaction raw material solution was dissolved to absorb the entire amount.
This cotton cloth and dodecane (15 ml) are placed in a Teflon (registered trademark) container (capacity: 100 ml), and the cotton cloth is immersed in dodecane for 3 minutes, and the reaction raw material solution present on or near the surface of the cotton fiber is washed with the cotton cloth. Was transferred into the inside of the pores of the cotton fiber and into the cotton fiber tissue. Thereafter, a lid made of Teflon (registered trademark) was put on and sealed, and microwave heating was performed. Using MicroSYNTH (trade name) (manufactured by Milestone General Co., Ltd.) as a microwave heating apparatus, heating was performed for 5 minutes at a solvent temperature of 150 ° C. and a pressure in the vessel at the start of heating of 1 atm (101 kPa). . The pressure in the vessel when reaching 150 ° C. was 1.2 atm. This increase in the pressure in the container is presumed to be because the water contained in the silver nitrate solution became gas. For the temperature measurement, the temperature of dodecane was measured using an optical fiber thermometer. For the pressure measurement, the pressure in the container was measured using a pressure sensor attached to MicroSYNTH.
After the heating, the container was cooled to 50 ° C., and the cotton cloth was taken out of the container. Then, it was washed and dried. For washing, a cotton cloth was immersed in ethanol and washed with an ultrasonic cleaner for 3 minutes. The cotton cloth was dried naturally in the air at room temperature for 24 hours.
Then, using a scanning electron microscope (SEM) (S-4800 (trade name) manufactured by Hitachi High-Technologies Corporation) and an energy dispersive X-ray spectroscopy (EDX) (QUANTAX 400 (trade name) manufactured by BRUKER), a cotton cloth cross section is used. Was observed and the composition was analyzed.
The cotton cloth was cut using a cutter, and the cross section was observed by SEM. As shown in FIG. 7A, in the SEM cross-sectional image of the cotton cloth, the composition of the cross-section of the cotton fiber 111 was analyzed along the direction of arrow A shown near the center of the figure, and one cotton fiber was analyzed. The intensity distribution of the silver component and the carbon component in the diameter direction was examined. As shown in FIG. 7 (B), it was confirmed from the intensity distribution of the components that the surface of the cotton fiber was mainly composed of the carbon component and the silver component was hardly contained on the surface of the cotton fiber. Further, it is known that the cotton fiber has a hollow (lumen), and the silver component shows two peaks. Therefore, the cotton fiber is selectively formed in the gap between the microfibrils 118 (see FIG. 6) of the secondary cell wall 116. It can be said that it is distributed in.

[Example 2]
In Example 2, a sample was prepared as follows. Using a commercially available cotton cloth (2.5 cm (length) × 5 cm (width) × 0.25 mm (thickness), basis weight 300 g / m ² ) as a measurement sample, 0.4 M of silver acetate and 0.4% of tetrasodium ethylenediaminetetraacetate were used. It was immersed in an ethylene glycol solution (0.5 ml) in which 8 M was dissolved for 5 minutes to absorb the whole amount.
This cotton cloth, dodecane (15 ml) and hexane (5 ml) were placed in a Teflon (registered trademark) container (capacity: 100 ml), and the cotton cloth was immersed in a mixed solvent of dodecane and hexane for 3 minutes, and the surface of the cotton fiber or The reaction raw material solution existing in the vicinity was transferred to the inside of the pores of the cotton fibers of the cotton cloth and into the cotton fiber structure. Thereafter, a lid made of Teflon (registered trademark) was put on and sealed, and microwave heating was performed as in Example 1. The temperature of the solvent was set to 150 ° C., the pressure in the container at the start of heating was set to 1 atm, and heating was performed for 5 minutes. The pressure in the container when 150 ° C. was reached was 3.5 atm. This increase in the pressure in the container is presumed to be due to a part of hexane (boiling point: 69 ° C.) becoming gas.
After the heating, the container was cooled to 50 ° C., and the cotton cloth was taken out of the container. Then, it was washed and dried. For washing, the cotton cloth was immersed in ethanol and washed with an ultrasonic cleaner for 3 minutes. The cotton cloth was dried naturally in the air at room temperature for 24 hours.
Then, the cross section of the cotton cloth was observed and the composition was analyzed using SEM and EDX. As shown in FIG. 8 (A), in the SEM cross-sectional image of the cotton cloth, the composition of the cross section of the cotton fiber was analyzed along the direction of arrow B shown near the center of the figure. The intensity distribution of the silver component and the carbon component in the diameter direction was examined. As a result, as shown in FIG. 8B, it was confirmed from the intensity distribution of the components that the surface of the cotton fiber was mainly composed of the carbon component, and that the silver component was hardly contained on the surface of the cotton fiber. The silver component showed a peak near the hollow portion of the cotton fiber. This was because the pressure in the container was increased, so that the reaction raw material solution moved to the center of the cotton fiber as compared with Example 1, and silver was distributed at the center in the thickness direction of the cotton fiber.

[Example 3]
In Example 3, a cotton cloth containing amorphous silica (silica gel) inside the fiber was manufactured as an example of including the inorganic compound in the cotton cloth. The details will be described.
A reaction for hydrolyzing TEOS with dimethylamine was used for the synthesis reaction of amorphous silica.
The sample was produced as follows. 0.05 g of a commercially available cotton cloth was used as a measurement sample and immersed in a reaction raw material solution (0.2 ml) for 1 minute to absorb the entire amount. As the reaction raw material solution, 2-propanol (2.5 ml), pure water (0.5 ml), TEOS (0.16 ml), and a 50% by mass dimethylamine solution (0.02 ml) were mixed for 1 minute by stirring with a stirrer. Was used. When this solution was allowed to stand at 25 ° C., it was confirmed by a transmission electron microscope that the transparent solution gradually turned white after about 10 minutes, and that the synthesis reaction of amorphous silica was completed after about 3 hours. Confirmed from particle observation. A cotton cloth was immersed for 1 minute using the reaction raw material solution immediately after stirring by the stirrer. Thereafter, the cotton cloth was put into a quartz test tube (inner diameter 4 mm, outer diameter 6 mm) filled with Florinert (FC-43 manufactured by 3M). Then, one end of the test tube is connected to a plunger pump, and further pressurized to about 5 atm by sending florinate, and the reaction raw material solution existing on or near the surface of the cotton fabric fiber is filled into the inside of the fiber hole or inside. It migrated into the fibrous tissue. The pressurization was completed within 10 minutes from the start of the mixing of the reaction raw material solution, and the pressurized state at about 5 atm was maintained at 25 ° C. for 3 hours. Three hours after the start of pressurization, the cotton cloth was taken out of the test tube, washed and dried. For washing, a cotton cloth was immersed in ethanol and washed with an ultrasonic cleaner for 3 minutes. The cotton cloth was dried naturally in the air at room temperature for 24 hours.
Thereafter, the cross section of the fiber of the cotton cloth was observed and the composition was analyzed using SEM and EDX. The fibers of the cotton cloth were cut using a cutter, and the cross section was observed by SEM. As shown in FIG. 9A, in the SEM cross-sectional image of the fiber, the composition of the cross section of the fiber was analyzed along the direction of arrow A, and the strength of the silicon component and the carbon component in the diametric direction for one fiber. The distribution was examined. From the intensity distribution of the components shown in FIG. 9B, it was found that the silicon component and the carbon component were distributed in the same region, and the amorphous silica was distributed inside the fiber.

[Example 4]
Example 4 produced a fiber containing amorphous silica (silica gel) inside Kapok fiber (commonly known as panya cotton) as an example of inclusion of a functional substance in a natural fiber different from cotton cloth (cotton). . The details will be described.
The sample was produced as follows. A commercially available Kapok fiber (0.02 g) was used as a measurement sample, and immersed in a reaction raw material solution (0.5 ml) for 1 minute to absorb the entire amount. The same reaction raw material solution as in Example 3 was used. After immersion for 1 minute, the kapok fiber was put into a quartz test tube (inner diameter 4 mm, outer diameter 6 mm) filled with Fluorinert. Then, one end of the test tube is connected to a plunger pump, and further pressurized to about 5 atm by sending florinate, and the reaction raw material solution present on or near the surface of the kapok fiber is transferred into the inside of the kapok fiber. I let it. The pressurization was completed within 10 minutes from the start of the mixing of the reaction raw material solution, and the pressurized state at about 5 atm was maintained at 25 ° C. for 3 hours. Three hours after the start of pressurization, the Kapok fiber was taken out of the test tube, washed and dried. For washing, the Kapok fiber was immersed in ethanol, and washed with an ultrasonic cleaner for 3 minutes. For drying, the kapok fiber was naturally dried in the air at room temperature for 24 hours.
Thereafter, the Kapok fiber was cut using a cutter, and the cross section was observed by SEM. A cross-sectional image of the Kapok fiber before absorbing the reaction raw material solution shown in FIG. 10A and a cross-sectional image of the Kapok fiber after absorbing the reaction raw material solution shown in FIG. As shown in FIG. 10B, it was confirmed that a large amount of particles existed in the hollow portion of the fiber. Further, the intensity distribution of the silicon component and the carbon component in the diameter direction of one fiber was examined by EDX. As shown in FIG. 11C, it was confirmed that the silicon component was mainly distributed in the hollow portion of the fiber, and that the amorphous silica particles were mainly distributed in the hollow portion of the fiber.

[Example 5]
In Example 5, as an example of encapsulating an inorganic compound in a chemical fiber, a fiber containing silica inside a porous hollow fiber was produced. The details will be described.
The sample was produced as follows. A commercially available porous hollow fiber for a water purifier (MKC. MXJ (600 L) manufactured by Toray Industries, Inc.) is cut into a length of 3 cm to obtain a measurement sample, immersed in a reaction raw material solution, and degassed with an evaporator (about 0.8 mm). Pressure) to absorb the reaction raw material solution to the inside of the fiber of the porous hollow fiber. The same reaction raw material solution as in Example 3 was used. After absorbing the reaction raw material solution for about 1 minute, this fiber was put into a test tube (inner diameter 4 mm, outer diameter 6 mm) made of quartz filled with Fluorinert, and one end of the test tube was connected to a plunger pump. Was fed to the reactor to increase the pressure to about 5 atm, and the reaction raw material solution existing on or near the surface of the fiber was transferred into the fiber. The pressurization was completed within 10 minutes from the start of the mixing of the reaction raw material solution, and the pressurized state at about 5 atm was maintained at 25 ° C. for 3 hours. Three hours after the start of pressurization, the fibers of the porous hollow fiber were taken out of the test tube, and the taken out fibers were air-dried in the air at room temperature for 72 hours.
Then, the cross section of the fiber of the porous hollow fiber was observed and the composition was analyzed using SEM and EDX. The fiber was cut using a cutter, and the cross section was observed by SEM. As shown in FIG. 12A, in the SEM cross-sectional image of the fiber of the porous hollow fiber, the composition of the cross-section of the fiber was analyzed along the direction of arrow A shown near the center of the figure. The strength distribution of the silicon component and the carbon component in the diameter direction with respect to the fiber was examined. From the intensity distribution of the components shown in FIG. 12 (B), it was found that the silicon component and the carbon component were distributed in the same region, and the amorphous silica was distributed inside the fiber of the porous hollow fiber. .

[Example 6]
In Example 6, as an example of encapsulating an inorganic compound in a chemical fiber, a fiber containing zeolite inside a porous hollow fiber was produced. The details will be described.
The sample was produced as follows. A commercially available porous hollow fiber (manufactured by Sumitomo Electric Industries, Ltd., trade name: Poeflon (registered trademark) tube, (material: Teflon (registered trademark)), inner diameter 3 mm, outer diameter 4 mm) is cut into 4 cm lengths. Then, both ends of the fiber were fused and sealed by heating with a burner to obtain a measurement sample. Then, it was immersed in the reaction raw material solution and deaerated (about 0.8 atm) by an evaporator to absorb the reaction raw material solution to the inside of the fiber. The reaction raw material solution is obtained by dissolving sodium aluminate, a 30% by mass solution of colloidal silica, and sodium hydroxide in pure water, respectively, to obtain Na: Al: Si: H ₂ O = 4: 1: 1: 53. And then stirred at room temperature for 24 hours. After absorbing the reaction raw material solution for about 1 minute, the fiber, dodecane (15 ml) and hexane (5 ml) were placed in a Teflon (registered trademark) container (capacity: 100 ml), and Teflon (registered trademark) was added. A lid was put on and sealed, and microwave heating was performed in the same manner as in Example 1. The temperature of the solvent was set to 150 ° C., and the pressure in the container at the start of heating was set to 1 atm, and heating was performed for 10 minutes. The pressure in the container when 150 ° C. was reached was about 5 atm. This increase in the pressure in the container is presumed to be due to a part of hexane (boiling point: 69 ° C.) becoming gas. After heating, the container was cooled to 30 ° C., the fiber was taken out from the container, and air-dried in the air at room temperature for 72 hours.
Thereafter, when the fiber was cut, it was confirmed that a white inclusion was attached to the inner wall of the fiber. Observation and composition analysis were performed on this inclusion using the same SEM and EDX as in Example 1.
The fiber was cut using a cutter, and the cross section was observed by SEM. As can be seen from the SEM image shown in FIG. 13A, spherical particles having a particle diameter of 5 to 10 μm were confirmed. Further, from the result of the composition analysis by EDX shown in FIG. 14B, it was found that the oxygen, sodium, silicon, and aluminum components were homogeneously distributed. The composition ratio (atom%) determined from the energy spectrum of EDX was O: Na: Si: Al = 50.2: 29.1: 11.4: 9.3. Subsequently, X-ray diffraction measurement (apparatus: SmartLab, manufactured by Rigaku Corporation) was performed on the powder of the inclusions. As a result, the SOD type zeolite structure was confirmed from the diffraction pattern shown in FIG. 15 (C), and it was found that zeolite fine particles were contained in the inclusions of the fibers.

[Example 7]
In Example 7, as an example of encapsulating an organic compound in a chemical fiber, a fiber containing polyimide inside a porous hollow fiber was produced. The details will be described.
The sample was produced as follows. A commercially available porous hollow fiber (manufactured by Sumitomo Electric Industries, trade name: Poeflon (registered trademark) tube, inner diameter 1 mm, outer diameter 2 mm) is cut into a length of 4 cm to obtain a measurement sample, and both ends of the fiber are burner. And sealed by heating. Then, it was immersed in the reaction raw material solution and deaerated (about 0.8 atm) by an evaporator to absorb the reaction raw material solution to the inside of the fiber. As a reaction raw material solution, poly (4,4'-oxydiphenylene-pyromellitimide) (a copolymer of pyromellitic dianhydride and 4,4'-oxydianiline, and a typical polyimide, Kapton (registered trademark)) Was used, and an N, N-dimethylacetamide solution in which 2% by mass of acetic anhydride and 0.06% by mass of pyridine were dissolved was used. After allowing the fiber to absorb the reaction raw material solution for about 10 seconds, the fiber and hexane (15 ml) are placed in a Teflon (registered trademark) container (capacity: 100 ml), and a Teflon (registered trademark) lid is placed. Then, microwave heating was performed in the same manner as in Example 1. Heating was performed for 30 minutes at a solvent temperature of 90 ° C. and a pressure in the vessel at the start of heating of 1 atm. The pressure in the vessel when the temperature reached 90 ° C. was 3 atm. This increase in the pressure in the container is presumed to be due to a part of hexane (boiling point: 69 ° C.) becoming gas. After heating, the container was cooled to 25 ° C., the porous hollow fiber was taken out of the container, and was naturally dried in the air at room temperature for 24 hours.
The outer surface of the porous hollow fiber after drying had the same white color as before the experiment, but when the fiber was cut, as shown in the photograph shown in FIG. 16, a powdery yellow inclusion on the fiber inner wall was observed. Was adhered, and it was found that the polyimide powder was contained in the fiber.

Example 8
In Example 8, as an example of inclusion of an organic crystal in a chemical fiber, a fiber containing a hinokitiol crystal inside a porous hollow fiber was produced. The details will be described.
The present embodiment is an example in which a raw material is dissolved in a hydrophobic solvent and a pressure is applied with a hydrophilic solvent, which is a combination of incompatible solvents opposite to those in Examples 1 to 7.
The sample was produced as follows. A commercially available porous hollow fiber (manufactured by Sumitomo Electric Industries, Ltd., trade name: Poeflon (registered trademark) tube, inner diameter 3 mm, outer diameter 4 mm) is cut into a length of 4 cm, and both ends of the porous hollow fiber are burned. The sample was melted and sealed by heating in the above to prepare a measurement sample. Then, the reaction material solution was immersed in the reaction material solution and degassed (about 0.8 atm) by an evaporator to absorb the reaction material solution to the inside of the porous hollow fiber. A hexane solution in which 1% by mass of hinokitiol was dissolved was used as a reaction raw material solution. After absorbing the reaction material solution for about 1 minute, the porous hollow fiber and water are put into a 1 m long tube (inner diameter: 10 mm) sealed at one end, and the tube is placed vertically with the sealed portion down. And the porous hollow fiber was held near the sealed portion of the tube, so that the hydrostatic pressure of water was increased to about 1.1 atm. Thereafter, the vicinity of the sealed portion of the tube containing the porous hollow fibers was immersed in a water bath, and the temperature was raised from 25 ° C. The heating was stopped when the temperature reached 75 ° C. about 15 minutes after the start of heating, and the tube was taken out into the atmosphere and cooled. Ten minutes after the start of cooling, the tube surface temperature was 25 ° C., which is room temperature. At this time, the porous hollow fiber was taken out of the tube and air-dried in the air at room temperature for 24 hours.
Then, the porous hollow fiber was cut using a cutter, and the fiber cross section was observed with a laser microscope (VK-9510, manufactured by KEYENCE). As shown in FIG. 17, a transparent crystal having a diameter of about 50 μm was attached to the inner wall of the fiber, and it was found that the fiber contained hinokitiol crystal.

[Example 9]
In Example 9, a fiber containing an alum crystal inside a porous hollow fiber was manufactured as an example of inclusion of an inorganic crystal in a chemical fiber. The details will be described.
The sample was produced as follows. Cut a commercially available porous hollow fiber (manufactured by Sumitomo Electric Industries, Ltd., trade name: Poeflon (registered trademark) tube, inner diameter 3 mm, outer diameter 4 mm) into a length of 4 cm, and heat both ends of the fiber with a burner. And sealed to obtain a measurement sample. Then, the solution was immersed in a reaction raw material solution heated to 60 ° C. in a water bath and deaerated (0.5 to 0.9 atm) by an evaporator to absorb the solution to the inside of the fiber. As a reaction raw material solution, a solution prepared by dissolving 170 g of calcined alum (AlK (SO ₄ ) ₂ .12H ₂ O) in 1 L of water was used. After absorbing the reaction raw material solution for about 1 minute, the porous hollow fiber was quickly placed in a quartz test tube (inner diameter 4 mm, outer diameter 6 mm) filled with dodecane at 60 ° C. Then, one end of the test tube was connected to a plunger pump, and further pressurized to about 1.1 atm by feeding dodecane. After immersing this test tube in a water bath at 60 ° C. for 5 minutes, the test tube was gradually cooled. About 10 minutes after the start of the slow cooling, the temperature became 25 ° C., and the porous hollow fiber was taken out of the test tube and air-dried in the air at room temperature for 72 hours.
Thereafter, the porous hollow fiber was cut using a cutter, and the fiber cross section was observed with a laser microscope. As shown in FIG. 18, a transparent crystal having a diameter of several hundred μm was attached to the inner wall of the fiber, and it was found that the fiber contained alum crystals.

Example 10
In Example 10, as an example of inclusion of the inorganic crystal in the natural fiber, a fiber containing alum crystals in bamboo was manufactured. The details will be described.
The sample was produced as follows. A bamboo (diameter 2 mm, length 10 mm) is used as a measurement sample, immersed in a reaction raw material solution heated to 60 ° C. in a water bath, and deaerated (0.5 to 0.9 atm) with an evaporator to obtain a bamboo fiber. The solution was absorbed to the inside. As a reaction raw material solution, a solution prepared by dissolving 170 g of calcined alum (AlK (SO ₄ ) ₂ .12H ₂ O) in 1 L of water was used. After absorbing the reaction raw material solution for about 5 minutes, the bamboo fiber was quickly placed in a quartz test tube (inner diameter 4 mm, outer diameter 6 mm) filled with hexane at 60 ° C. Then, one end of the test tube was connected to a plunger pump, and hexane was further fed to increase the pressure to about 5 atm. While maintaining the pressure of about 5 atm, the test tube was immersed in a water bath at 60 ° C. for 10 minutes, and then the test tube was gradually cooled. About 10 minutes after the start of the slow cooling, the temperature reached 25 ° C., and the bamboo fiber was taken out of the test tube and air-dried in the air at room temperature for 72 hours.
Thereafter, the bamboo fiber was cut in parallel with the conduit direction, and the fiber cross section was observed and analyzed for composition using SEM and EDX. As can be seen in the portion surrounded by the dotted line in the SEM image shown in FIG. 19 (A), a crystalline material equivalent to the diameter of the conduit (about 50 μm) was confirmed in the conduit. From the result of the composition analysis by EDX shown in FIG. 20B, it was found that the alum crystals were contained in the fiber inclusions because the crystals contained sulfur and aluminum components.

[Example 11]
Example 11 produced a fiber containing alum crystals inside wood as an example of inclusion of inorganic crystals in natural fibers. The details will be described.
The sample was produced as follows. The same procedure was followed except that cedar (diameter 2 mm, length 8 mm) was used as a measurement sample instead of the bamboo of Example 10.
The produced fiber was cut in parallel with the direction of the conduit, and the fiber cross section was observed and analyzed for composition using SEM and EDX. As can be seen in the portion surrounded by the dotted line in the SEM image shown in FIG. 21A, a crystal having a diameter (about 30 μm) equivalent to that of the conduit was found in the conduit. The composition analysis by EDX centering on the portion surrounded by the dotted line in FIG. 21A shown in FIG. 22B shows that the crystal contains the sulfur component and the aluminum component, Was found to contain alum crystals.

[Example 12]
In Example 12, the silver component was included inside the cotton cloth using the resonator type microwave heating device. The details will be described.
The sample was produced as follows. Using 0.013 g of a cotton cloth as a measurement sample, it was immersed in an ethylene glycol solution (0.05 ml) in which 400 mM of silver nitrate as a reaction raw material solution was dissolved for 5 minutes to absorb the entire amount.
This cotton cloth was placed in a quartz test tube (inner diameter 4 mm, outer diameter 6 mm, length 100 mm) filled with dodecane, and one end of the test tube 21 was connected to the plunger pump 15 as shown in FIG. Then, the dodecane 41 is fed into the test tube 21 to pressurize it to about 3 atm, and the reaction raw material solution existing on or near the surface of the cotton cloth 31 is transferred into the inside of the pores of the cotton cloth and into the fiber structure. I let it. Thereafter, the cotton cloth 31 was heated using the resonator-type microwave heating device 10. The pressure in the test tube 21 was measured by a pressure gauge 16 (BA10-273-5000 manufactured by Nagano Keiki Co., Ltd.) provided at the inlet of the test tube 21.
As the cavity resonator 11 of the microwave heating device 10, a metal cavity resonator having a cylindrical microwave irradiation space 12 inside was used. The inside diameter of the microwave irradiation space 12 is set according to the frequency band of a microwave oscillator (not shown) so that a standing wave called _TM010 mode can be formed. The inner diameter of the microwave irradiation space 12 refers to a circular diameter that is a cross-sectional shape in a direction orthogonal to the central axis C of the cylindrical microwave irradiation space 12. In the _TM010 mode, a standing wave at which the electric field is maximized is formed on the central axis C of the cylinder. A VCO oscillator (Voltage Controlled Oscillator) whose frequency can be adjusted was used as a microwave oscillator provided with a microwave generator (not shown). A detection unit (not shown) for measuring the energy intensity inside the microwave irradiation space 12 such that the oscillation frequency of the microwave oscillator becomes a frequency at which the _TM010 mode standing wave can be maintained in the cavity resonator 11. ) Was controlled and adjusted.

A semiconductor-type microwave generator (895-935 MHz, maximum output 300 W) is used for the microwave generator (not shown), the cavity resonator 11 has an inner diameter of 239 mm, and the irradiation length on the test tube 21 is 40 mm. Cavity resonator was used. A portion including the cotton cloth 31 in the test tube 21 was set in the cavity resonator 11, and microwave heating was performed at a set temperature of 130 ° C. for 1 minute. The surface temperature of the test tube 21 was measured using a radiation thermometer (not shown) for temperature measurement.
After the heating, the cotton cloth 31 was immersed in ethanol, and washed with an ultrasonic cleaner for 3 minutes. Then, it was air-dried in the air at room temperature for 24 hours.
FIG. 24 shows the intensity distribution of the silver component and the carbon component on the cross section of one fiber obtained by SEM-EDX measurement. Since the silver component showed two peaks, it can be said that the silver component was selectively distributed in the gaps between the microfibrils 118 (see FIG. 6) of the secondary cell wall 116.

Reference Signs List 10 microwave heating device 11 cavity resonator 12 microwave irradiation space 15 plunger pump 16 pressure gauge 21 test tube 31 cotton cloth 41 dodecane 110 porous material 111 cotton fiber 111S outer surface 112 cuticle layer 113 network layer 114 winding layer 115 primary Cell wall 116 Secondary cell wall 117 Lumen
118 Microfibril 121 Permeation area of reaction raw material solution 131 Container 132 Solvent 133 Lid MW Microwave

Claims (17)

A step of penetrating the reaction raw material solution into the pores of the porous material,
The porous material impregnated with the reaction material solution is immersed in a solvent that is incompatible with the reaction material solution, and the reaction material solution existing on the surface of the porous material and / or in the vicinity thereof is removed. A step of moving the inside of the pores and the material structure of the porous material,
Causing a chemical reaction to occur in the reaction raw material solution transferred into the inside of the pores or the material structure of the porous material.   The method for producing a functional porous material according to claim 1, wherein the chemical reaction is caused by heating.   The method for producing a functional porous material according to claim 2, wherein the heating is heating by microwave irradiation.   The method for producing a functional porous material according to claim 3, wherein the microwave irradiation is a single mode microwave irradiation. The reaction raw material solution contains a metal precursor,
The method for producing a functional porous material according to any one of claims 1 to 4, wherein the chemical reaction is a reaction for depositing a metal from the metal precursor. The reaction raw material solution contains an alkoxysilane compound,
The method for producing a functional porous material according to any one of claims 1 to 4, wherein the chemical reaction is a reaction that produces silica by hydrolysis of the alkoxysilane compound and subsequent condensation polymerization.   The method for producing a functional porous material according to any one of claims 1 to 4, wherein the chemical reaction is crystallization or precipitation of a chemical substance in the reaction raw material solution. The reaction raw material solution contains a silica source, an alkali source and water,
Or, comprising a metal source capable of replacing silicon in addition to the silica source, the alkali source and the water,
The method for producing a functional porous material according to any one of claims 1 to 4, wherein the chemical reaction is a reaction that generates zeolite. The reaction raw material solution contains a polyamic acid,
The method for producing a functional porous material according to any one of claims 1 to 4, wherein the chemical reaction is a reaction that generates a polyimide by a dehydration and ring closure reaction of the polyamic acid.   The porous material according to any one of claims 1 to 9, wherein the porous material is composed of a plant fiber, an animal fiber, a chemical fiber, a hollow fiber, or a hollow particle, or a composite material composed of two or more of these. Item 14. The method for producing a functional porous material according to item 8.   The method for producing a functional porous material according to claim 10, wherein the plant fiber is cotton.   A functional porous material that contains a functional chemical substance in the pores of the porous material.   13. The functional porous material according to claim 12, wherein the functional chemical substance includes a metal.   14. The functional porous material according to claim 13, having an antibacterial and / or antiviral function by the metal.   The functional porous material according to claim 13, wherein the functional porous material exhibits conductivity due to the metal.   The said porous material is a composite material containing a cotton material and silicon, and the silicon concentration inside and / or in the cotton material tissue is higher than the outer surface of the cotton material, according to any one of claims 12 to 15. Functional porous material.   The porous material according to any one of claims 12 to 15, wherein the porous material is a porous hollow fiber having carbon as a structure, and zeolite is held in a hollow portion and / or an inner surface of the porous hollow fiber. Functional porous material.