JP2019044049A - Resin porous body and carbonized product of the same, adsorbent, and method for producing resin porous body - Google Patents

Abstract

To provide a resin porous body excellent in adsorption ability.SOLUTION: In a first embodiment, a resin porous body is provided which has a BET specific surface area of 300 m/g or more, preferably, 500 m/g or more, and in which a circular opening diameter showing a peak in a circular opening diameter distribution measured in the range of 0.1-400 nm is 2 or more and less than 50 nm. In a second embodiment, a resin porous body is provided which is identical to the resin porous body in the first embodiment except that the resin porous body includes a polycondensation body of a compound having a phenolic hydroxyl group and of aldehyde compound. In a third embodiment, a carbonized product is provided which is a carbonized product of the resin porous body, and has circular opening diameter showing a peak in a circular opening diameter size distribution measured in the range of 0.1-400 nm is 2 or more and less than 50 nm. An adsorbent is provided which includes the resin porous body.SELECTED DRAWING: None

Description

  The present invention relates to a resin porous body and its carbide, an adsorbent, and a method for producing the resin porous body.

  BACKGROUND ART Conventionally, porous materials having pores formed therein have excellent properties such as light weight, heat insulation and sound insulation, and are used in a very wide range of fields. In particular, these porous materials are used as adsorbents for adsorbing perfumes, drugs and the like.

  As widely used porous materials, for example, silica airgel as described in Patent Document 1, porous carbon material as described in Patent Document 2, as described in Patent Document 3 There is a controlled pore size organic porous resin.

JP, 2014-61457, A Unexamined-Japanese-Patent No. 2017-31042 Japanese Patent Application Publication No. 2003-166982

  However, the conventional porous materials described in Patent Documents 1 to 3 still have room for improvement in terms of adsorption capacity when used as an adsorbent.

  Then, an object of this invention is to provide the resin porous body excellent in adsorption capacity, its carbide, and the adsorption material containing the said resin porous body. Moreover, this invention aims at providing the manufacturing method of the resin porous body excellent in adsorption capacity.

  In order to solve the above problems, the inventors of the present invention have found that a resin porous body having an air hole diameter controlled to an arbitrary size and further having a BET specific surface area controlled to a predetermined range has excellent adsorption ability. The present invention has been completed.

In the present invention, as a first aspect, the BET specific surface area is 300 m ² / g or more, and the pore diameter distribution measured in the range of 0.1 to 400 nm shows a peak at 2 to 50 nm. And provide a resin porous body.

  Preferably, pores having communication properties are formed in the resin porous body.

  The resin porous body preferably contains a polycondensate of a compound having a phenolic hydroxyl group and an aldehyde compound.

  The present invention provides, as a second aspect, an adsorbent comprising the above-described resin porous body.

This invention is a carbide of a resin porous body as 3rd aspect, Comprising: BET specific surface area is 500 m < ² > / g or more, and the hole diameter distribution measured in the range of 0.1-400 nm shows a peak. Provided is a carbide having a pore diameter of 2 nm or more and less than 50 nm.

  The present invention provides, as a fourth aspect, a resin porous process comprising the steps of: polycondensation of a compound having a phenolic hydroxyl group with an aldehyde compound in a solvent to obtain a wet gel; and removing the solvent from the wet gel. Provided is a method of manufacturing a body.

  According to the present invention, it is possible to provide a resin porous body excellent in adsorption ability and its carbide, and an adsorbent containing the resin porous body. In addition, the present invention can provide a method for producing a resin porous body excellent in adsorption ability.

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

In the resin porous body according to one embodiment, the BET specific surface area is 300 m ² / g or more, and the pore size distribution measured in the range of 0.1 to 400 nm shows a peak at 2 to 50 nm. It is.

  The resin porous body is formed of a resin in which pores are formed. The resin porous body preferably contains a polycondensate of a compound having a phenolic hydroxyl group and an aldehyde compound.

  The compound having a phenolic hydroxyl group is not particularly limited, and examples thereof include hydroquinone, catechol, resorcinol, dihydroxynaphthalene, bisphenol A, bisphenol F, biphenol, bisphenol fluorene, biscresol fluorene, and hydroxymethyl compounds or alkoxymethyl compounds thereof. One or more selected from the above can be used.

  Examples of aldehyde compounds include, but are not limited to, formaldehyde, paraformaldehyde, acetaldehyde, propylaldehyde, butyraldehyde, isobutyraldehyde, pentylaldehyde, hexyl aldehyde, alkyl aldehydes such as glutaraldehyde, salicylaldehyde, 3-hydroxybenzaldehyde, 4- Hydroxybenzaldehyde such as hydroxybenzaldehyde, 2-hydroxy-4-methylbenzaldehyde, 2,4-dihydroxybenzaldehyde, 3,4-dihydroxybenzaldehyde, 2-hydroxy-3-methoxybenzaldehyde, 3-hydroxy-4-methoxybenzaldehyde, 4-hydroxybenzaldehyde Hydroxy-3-methoxybenzaldehyde, 3-ethoxy-4-hydroxybenzaldehyde, 4 Benzaldehyde having both a hydroxy group and an alkoxy group such as hydroxy-3,5-dimethoxybenzaldehyde, alkoxybenzaldehyde such as methoxybenzaldehyde and ethoxybenzaldehyde, 1-hydroxy-2-naphthaldehyde, 2-hydroxy-1-naphthaldehyde, 6 It is possible to use one or more selected from hydroxynaphthaldehyde such as -hydroxy-2-naphthaldehyde, halogenated benzaldehyde such as brom benzaldehyde, and furfural.

The BET specific surface area of the resin porous body is 300 m ² / g or more. The BET specific surface area is preferably 400 m ² / g or more, more preferably 500 m ² / g or more, and still more preferably 600 m ² / g or more, from the viewpoint of further improving the adsorption capacity of the resin porous body. . The BET specific surface area should be as large as possible, but may be, for example, 2500 m ² / g or less. The BET specific surface area refers to the specific surface area that can be calculated by the BET method.

  A plurality of pores are formed inside the resin porous body. By using the pore analyzer, the pore size distribution of the pores formed in the resin porous body can be obtained. About the resin porous body which concerns on this embodiment, the hole diameter which the hole diameter distribution measured in the range whose hole diameter is 0.1-400 nm shows a peak is 2 nm or more and less than 50 nm. Hereinafter, "a pore diameter whose pore diameter distribution measured in a range of 0.1 to 400 nm exhibits a peak" may be simply referred to as "a pore diameter peak". The pore diameter peak is preferably 2 nm or more and less than 40 nm, more preferably 3 nm or more and less than 30 nm, and still more preferably 10 nm or more and less than 30 nm.

  Regarding the pores of the resin porous body, the pores having a diameter of less than 2 nm are "micropores", the pores having a diameter of 2 nm or more and less than 50 nm are "mesospores", and the pores having a diameter of 50 nm or more are "macro" Sometimes called "hole". In the resin porous body according to the present embodiment, any of micropores, mesopores and macropores may be formed, but since the pore diameter peak is 2 nm or more and less than 50 nm, the mesopores are mainly It can be said that the resin porous body is formed.

  The pore volume can also be determined by using a pore analyzer. In the resin porous body, the volume of mesopores should be as large as possible, preferably 0.05 cc / g or more, more preferably 0.4 cc / g or more, and still more preferably 0.6 cc / g or more It is. The volume of mesopores (hereinafter also referred to as “mesopore volume ratio”) to the pore volume of 1 to 100 nm is preferably as large as possible, preferably 10% by volume or more, and more preferably 20 volumes. %, And more preferably 50% by volume or more.

  In the resin porous body, the micropore volume should be as small as possible, preferably 0.5 cc / g or less, more preferably 0.4 cc / g or less, and still more preferably 0.3 cc / g or less It is. The volume of micropores (hereinafter also referred to as “micropore volume ratio”) to the pore volume with a pore diameter of 1 to 100 nm is preferably as small as possible, preferably 50 volume% or less, more preferably 30 volumes % Or less, more preferably 20% by volume or less.

  It is preferable that pores having communication properties be formed in the resin porous body. The pores having the communication property in the present specification mean pores formed such that the resin porous body can pass a liquid (for example, water) by connecting the pores. In the resin porous body, it is not necessary for all the pores to be in communication, and some independent pores may be formed as long as a liquid can be allowed to pass as the whole resin porous body.

  The shape of the resin porous body is not particularly limited, but may be massive, plate-like, membrane-like, powder-like, or the like. From the viewpoint of increasing the specific surface area, it is preferably in the form of powder.

  The resin porous body is used, for example, in applications such as adsorbents, absorption materials, sound absorbing materials, heat insulating materials, radio wave absorbing materials, scaffolds for cell culture, buffer materials, template materials, catalysts, sensors, separators, or heat exchangers. It can be used suitably. When a resin porous body is used as an adsorbent, excellent adsorption ability can be obtained. An adsorbent according to one embodiment includes the above-described resin porous body. The adsorbent may be a resin porous body itself or may contain other raw materials.

  The target substance to which the adsorbent adsorbs is a group consisting of dyes such as riboflavin, methylene blue and copper phthalocyanine, flavors, pharmaceutical compounds, naturally derived compounds such as proteins, carbohydrates and lipids, metals, salts, and ionized products It may be one or more selected. The adsorbent is difficult to be recovered by the conventional adsorption method or precipitation method, and there is a possibility that it can efficiently adsorb an object which could only be recovered by ultrafiltration.

  Next, a method for producing a resin porous body will be described. The method for producing a resin porous body according to one embodiment comprises a first step of obtaining a wet gel by polycondensing a compound having a phenolic hydroxyl group and an aldehyde compound in a solvent, and removing the solvent from the wet gel And 2).

  The first step can be performed, for example, as follows. First, a compound having a phenolic hydroxyl group and an aldehyde compound are added to a solvent and stirred. Next, a catalyst is added and the mixture is heated to polycondense the compound having a phenolic hydroxyl group with the aldehyde compound to obtain a wet gel. Before heating, an acid may be added, if necessary, and the step of stirring may further be provided.

  The solvent is not particularly limited, but may be water, an organic solvent, or a mixed solvent thereof. As the solvent, preferably, a compound having a phenolic hydroxyl group, an aldehyde compound, and a solvent having high solubility of a catalyst can be optionally selected, whereby a wet gel with few unreacted raw materials can be produced in a short time. Can.

  Organic solvents used for the solvent include propanol, butanol, octanol, ethylene glycol, glycerin, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, alcohols such as ethylene glycol monobutyl ether, propylene glycol monomethyl ether, methyl ethyl ketone, methyl isobutyl ketone and the like Ketones, butyl acetate, ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, esters such as propylene glycol monomethyl ether acetate, and the like.

  Although the catalyst is not particularly limited, basic catalysts such as sodium carbonate, potassium carbonate, ammonium carbonate, lithium hydroxide, sodium hydroxide, potassium hydroxide, magnesium hydroxide, calcium hydroxide, barium hydroxide, ammonia, amines, etc. It may be. Among these, inorganic basic catalysts are more useful because they are inexpensive and easy to handle.

  The molar ratio (P / A) of the compound (P) having a phenolic hydroxyl group to the aldehyde compound (A) is preferably 0.1 to 2.0, and more preferably 0.2 to 1.5. More preferably, it is 0.2 to 1.0. Thereby, a wet gel having a low content of unreacted aldehyde compounds can be suitably obtained.

  The molar ratio (P / B) of the compound (P) having a phenolic hydroxyl group to the catalyst (B) is preferably 1 to 50,000, more preferably 10 to 30,000, and still more preferably 20 to 20,000. is there. Thereby, the wet gel with few unreacted materials can be obtained in a short time.

  The weight ratio (P / S) of the compound (P) having a phenolic hydroxyl group to the solvent (S) is preferably 0.01 to 4, more preferably 0.05 to 1, and still more preferably 0.1 to 0.8. Thereby, the wet gel with few unreacted materials can be obtained in a short time.

  In the first step, the compound having a phenolic hydroxyl group and the aldehyde compound can be polycondensed, for example, by heating. The heating conditions are preferably 4 hours to 480 hours under a temperature of 40 ° C. to 90 ° C., more preferably 5 hours to 300 hours under a temperature of 50 ° C. to 90 ° C., still more preferably 60 ° C. to 80 C. for 6 hours to 200 hours. Thereby, the wet gel with few unreacted materials can be suitably obtained in a short time.

  In the second step, the method of removing the solvent may be, for example, atmospheric pressure drying, pinhole drying, heat drying, reduced pressure drying, heat reduced pressure drying, vacuum freeze drying, supercritical drying and the like. Among these, vacuum lyophilization or supercritical drying is preferable because it can prevent volumetric shrinkage after drying and breakage of pores.

  From the viewpoint of being able to efficiently control the evaporation rate of the solvent, the method of removing the solvent is a solvent substitution step of replacing the solvent in the wet gel obtained in the first step with another solvent, and a solvent-substituted wet gel And evaporating the solvent after substitution.

  According to the manufacturing method of the present embodiment, since the resin porous body can be polymerized in an aqueous solution, an organic solvent, or a mixed solvent thereof, the porous structure such as the pore size or specific surface area can be easily controlled. It is.

  Next, carbides according to an embodiment of the present invention will be described. The carbide according to the present embodiment may be a carbide obtained by thermally decomposing the above-mentioned resin porous body. The thermal decomposition method is not particularly limited, but a simple method is to heat the resin porous body under an inert gas atmosphere using an electric muffle furnace.

  The thermal decomposition temperature of the resin porous body is not particularly limited, but is preferably 600 to 1200 ° C., more preferably 800 to 1000 ° C. By heating in this temperature range, the thermal decomposition reaction is promoted, and a carbide having a more uniform molecular structure is obtained.

The BET specific surface area of the carbide is preferably 500 m ² / g or more, more preferably 700 m ² / g or more, and still more preferably 900 m ² / g or more. The BET specific surface area should be as large as possible, but may be, for example, 2500 m ² / g or less.

  A plurality of pores are formed in the interior of the carbide obtained by the method of the present embodiment, as in the resin porous body. Among carbides, the pore diameter measured at a pore diameter in the range of 0.1 to 400 nm exhibits a peak. The pore diameter is the same as that of the resin porous body, and is 2 nm or more and less than 50 nm. The pore diameter peak is preferably 2 nm or more and less than 40 nm, more preferably 3 nm or more and less than 30 nm, and still more preferably 10 nm or more and less than 30 nm.

  Similar to the resin porous body, the carbide of the resin porous body may be, for example, an adsorbent, a storage material, a sound absorbing material, a heat insulating material, a radio wave absorber, a scaffold for cell culture, a buffer, a template, a catalyst, a sensor, It can be used suitably for uses, such as a separator or a heat exchanger. When a carbide is used as an adsorbent, excellent adsorption capacity can be obtained. Furthermore, the carbide has a low thermal conductivity, has heat resistance, and is excellent in electrical conductivity.

  Hereinafter, although the example which shows the composition and effect of the present invention concretely is described, the present invention is not limited to the following examples.

Example 1
A stirrer is placed in a 50 mL laboratory screw tube, 4.8 g of resorcinol (manufactured by Wako Pure Chemical Industries, Ltd.) and 13.76 g of ultrapure water are added and stirred at room temperature, and then a 35-38% aqueous formaldehyde solution7. 18 g (manufactured by Wako Pure Chemical Industries, Ltd.) was added and stirred again at room temperature. Further, 0.92 g of a 5% aqueous solution of sodium carbonate (manufactured by Wako Pure Chemical Industries, Ltd.) is added, stirred for 15 minutes, transferred to a polypropylene container and sealed, and heated at 60 ° C. for 120 hours while standing still. The After heating, the container was taken out of the container, immersed in 50 mL of tert-butyl alcohol (manufactured by Wako Pure Chemical Industries, Ltd.), allowed to stand at room temperature for 1 day, and the supernatant was removed by decantation three times in total. Thereafter, it is frozen in a freezer at -20 ° C for 1 hour, transferred to a desiccator, and vacuum dried with a diaphragm pump (manufactured by KNF) at room temperature for 3 days or more to remove tert-butyl alcohol to remove resin porous material I got

[Examples 2 to 5]
Example 2 was carried out in the same manner as in Example 1, except that the content of the other raw materials was changed as shown in Table 1 without changing the content of resorcinol. A resin porous body of 5 to 5 was produced. P / A is the molar ratio of the compound (P) having a phenolic hydroxyl group to the aldehyde compound (A), and P / B is the molar ratio of the compound (P) having a phenolic hydroxyl group to the catalyst (B) And P / S represent a weight ratio of the compound (P) having a phenolic hydroxyl group to the solvent (S).

[Example 6]
A stir bar is put into a 50 mL laboratory screw tube, 1 g of 1,5-dihydroxynaphthalene, 2.05 g of ultrapure water and 4.8 g of propylene glycol monomethyl ether are added and stirred at room temperature, then 1 g of 35-38% aqueous formaldehyde solution Was added and stirred again at room temperature. Further, 0.53 g of a 5% aqueous solution of sodium carbonate was added, transferred to a polypropylene container, sealed, and heated at 90 ° C. for 3 days in a state of standing still. After heating, vacuum drying was performed by the same method as in Example 1 to obtain a resin porous body.

[Example 7]
A stir bar is put into a 50 mL laboratory screw tube, 1 g of 1,5-dihydroxynaphthalene, 2.3 g of ultrapure water and 5.8 g of propylene glycol monomethyl ether are added and stirred at room temperature, then 1 g of 35-38% aqueous formaldehyde solution Was added and stirred again at room temperature. Further, 0.6 g of a 1 M nitric acid aqueous solution was added, transferred to a polypropylene container, sealed, and heated at 80 ° C. for 3 days in a state of standing still. After heating, vacuum drying was performed by the same method as in Example 1 to obtain a resin porous body.

[Example 8]
A stir bar is put into a 50 mL laboratory screw tube, 1 g of 1,5-dihydroxynaphthalene, 2.3 g of ultrapure water and 4.8 g of propylene glycol monomethyl ether are added and stirred at room temperature, then 1 g of 35-38% aqueous formaldehyde solution Was added and stirred again at room temperature. 0.26 g of 5% aqueous solution of sodium carbonate was added, and after stirring for 90 minutes, 1 g of 1 M aqueous solution of nitric acid was further added, and the solution was stirred for 60 minutes at room temperature. The container was transferred to a polypropylene container, sealed, and heated at 80 ° C. for 3 days in a state of standing still. After heating, vacuum drying was performed by the same method as in Example 1 to obtain a resin porous body.

[Examples 9 to 13]
The resin of Examples 9 to 13 was prepared in the same manner as in Example 9 except that the stirring time from the addition of the aqueous sodium carbonate solution to the addition of the aqueous nitric acid solution and the pH of the solution before heating were changed as shown in Table 1. A porous body was obtained.

[Examples 14 to 16]
About porous resin of Example 3, 4 and 11, using the table-top vacuum gas displacement furnace FUA 112 DB made by ADVANTEC Co., Ltd. and heating each to 250 ° C. after heating for 1 hour at 250 ° C. in nitrogen gas atmosphere It was thermally decomposed by heating for 4 hours. Thereafter, natural cooling to room temperature was performed to obtain a carbide of the resin porous body. The carbide of Example 3 is Example 14, the carbide of Example 4 is Example 15, and the carbide of Example 11 is Example 16.

[Measurement of pore size peak / BET specific surface area]
The specific surface area and pore size distribution of the resin porous bodies and the carbides of Examples 1 to 16 were measured using a pore analyzer (manufactured by Quantachrome, AutoSorb iQ). As pretreatment, a 50 mg sample was collected in a sample tube (φ 9 mm) and vacuum heat dried at 100 ° C. for 1.5 to 2 hours to remove the adsorbed substance on the sample surface. During the measurement, the sample was cooled using liquid nitrogen, and helium was used as an inert gas, and nitrogen was used as an adsorption gas. The single molecule adsorption amount Wm (g) was calculated from the BET plot obtained from the measurement result using a BET equation, and the total surface area S _total (m ² ) and the specific surface area S _BET (m ² / g) were determined. Further, the pore size distribution was determined using the Kelvin equation and the BJH method using a desorption isotherm, and the pore size _peak求 め_peak (nm) was determined. At the same time, micropore volume V _mic (cc / g) which is a volume of pores having a diameter of less than 2 nm, mesopore volume V _meso (cc / g) which is a volume of pores having a diameter of 2 nm or more and less than 50 nm The pore volume V (cc / g) of 100 nm or less was calculated, and the mesopore volume ratio V _meso / V (%) in the pore volume of 100 nm or less was calculated. The measurement results are shown in Table 1.

[Adsorption test]
20 mg of a copper phthalocyanine complex (manufactured by Wako Pure Chemical Industries, Ltd.) is dissolved in 50 g of methanol or toluene, filtered using a disk filter (PTFE, manufactured by Membrane Solutions, φ 0.22 μm), and the filtrate is an example 20 mg of the resin porous body concerning 4 was added, and it stirred at room temperature with the mix rotor for 1 hour. After standing overnight, the supernatant was filtered using a disk filter (PTFE, φ 0.22 μm), and the filtrate was recovered. The filtrate was diluted to an arbitrary concentration, and the absorbance was measured using a spectrophotometer. The absorbance of the copper phthalocyanine solution diluted to the same concentration was measured, and the adsorptivity of the resin porous body was evaluated by the following formula (1). As a result, the resin porous body of Example 4 had a decrease in absorbance of 20% or more. Therefore, as represented by Example 4, the BET specific surface area is 300 m ² / g or more, and the pore diameter distribution measured in the range of 0.1 to 400 nm shows a peak at a pore diameter of at least 2 nm and less than 50 nm. It was found that a certain resin porous body had excellent adsorption ability.
Decrement rate of absorbance (= {1-(filtrate absorbance ÷ dye solution absorbance)} × 100) (1)

  According to the resin porous body of the present invention, substances of molecular size or particle size which have been difficult to recover can be adsorbed and recovered efficiently. In industrial waste water in particular, it can be used for the removal of pigment, animal vegetable oil and other harmful substances, or recovery of valuables such as metals. In addition, the method for producing a resin porous body in the present invention can be produced at low cost without major changes from the conventional production method. In addition, since a substance such as an inorganic compound to be a mold is unnecessary as in the case of the conventional porous resin material, it can be expected to suppress the manufacturing cost and to reduce waste.

Claims (6)

BET specific surface area is 300 m ² / g or more,
The resin porous body whose pore diameter which the pore diameter distribution measured in the range of 0.1-400 nm shows a peak is 2 nm or more and less than 50 nm.   The resin porous body according to claim 1, wherein pores having communication properties are formed.   The resin porous body of Claim 1 or 2 containing the polycondensate of the compound which has a phenolic hydroxyl group, and an aldehyde compound.   An adsorbent comprising the resin porous body according to any one of claims 1 to 3. A carbide of a porous resin body,
BET specific surface area is 500 m ² / g or more,
Carbide, wherein the pore size distribution measured in the range of 0.1 to 400 nm shows a peak at a pore size of 2 nm or more and less than 50 nm. Polycondensing a compound having a phenolic hydroxyl group and an aldehyde compound in a solvent to obtain a wet gel;
And D. removing the solvent from the wet gel.