WO2015190459A1

WO2015190459A1 - Siloxane-removing agent and siloxane-removing filter using same

Info

Publication number: WO2015190459A1
Application number: PCT/JP2015/066563
Authority: WO
Inventors: 増森　忠雄
Original assignee: 東洋紡株式会社
Priority date: 2014-06-10
Filing date: 2015-06-09
Publication date: 2015-12-17

Abstract

[Problem] To provide: a siloxane-removing agent that is capable of efficiently removing siloxane gases, and that has very low desorption levels; and a siloxane-removing filter in which the siloxane-removing agent is used. [Solution] A siloxane-removing agent in which 0.1 to 20 wt% of an acidic compound or metal salt is supported by activated carbon, wherein said siloxane-removing agent is characterized in that the water adsorption ratio of the siloxane-removing agent, which is obtained by dividing the amount of water adsorption at 25°C and 40% relative humidity by the amount of water adsorption at 25°C and 90% relative humidity, is at least 0.10.

Description

Siloxane removal agent and siloxane removal filter using the same

The present invention relates to a siloxane remover excellent in siloxane gas removal performance and low desorption, and a siloxane removal filter using the remover. More specifically, a siloxane remover that can efficiently remove siloxane gases and has less problems that the removed siloxane gases are desorbed due to environmental changes such as concentration, temperature, and humidity, and the like are used. The present invention relates to a siloxane removal filter. The environmental changes such as concentration, temperature, and humidity are changes in the range of 0 to 10 vol% in concentration, −30 to 300 ° C. in temperature, and 0 to 100 RH% in humidity. The siloxane gas is a gaseous compound having a siloxane bond (Si—O bond), for example, a linear and cyclic gaseous compound having 1 to 40 siloxane bonds. More specifically, hexamethyldisiloxane (L2), octamethyltrisiloxane (L3), decamethyltetrasiloxane (L4), dodecamethylpentasiloxane (L5), hexamethylcyclotrisiloxane (D3), octamethylcyclo Examples include tetrasiloxane (D4), decamethylcyclopentasiloxane (D5), dodecamethylcyclohexasiloxane (D6), and the like. Moreover, the low desorption property said here refers to the ratio of adsorption capacity and desorption amount (adsorption capacity / desorption amount).

Concerning pollutants in the atmosphere, there are a wide variety of types, and they are composed of polar gases such as hydrogen sulfide, ammonia, aldehyde, and acetic acid, and low polarity gases such as benzene, toluene, styrene, and siloxane gases. In particular, siloxane gases are known to cause various harmful effects. For example, particulate silicon oxide produced by combustion adheres to a gas turbine or a gas engine, causing a power generation failure, or forming a silica film on the surface of the gas sensor, causing a false alarm.

Conventionally, porous materials such as activated carbon, silica gel, zeolite, activated alumina and the like are often used for the purpose of removing siloxane gases.

As an adsorbent for a siloxane compound, activated carbon having at least one surface selected from the group consisting of iodine oxoacid, bromine oxoacid, iodine oxide, and bromine oxide (for example, patents) Document 1), activated carbon carrying a resin having a sulfonic acid group (for example, Patent Document 2) and activated carbon impregnated with a sulfonic acid group-modified metal oxide sol are known (for example, Patent Documents 3 and 4). However, there is no specific description regarding activated carbon as a carrier. For example, there is a problem that even if a general activated carbon is loaded with iodic acid, a resin having a sulfonic acid group, and a sulfonic acid group-modified metal oxide sol, low detachability is not sufficient. In addition, when activated carbon is loaded with a resin having a sulfonic acid group and a sulfonic acid group-modified metal oxide sol, the resin having a sulfonic acid group and the sulfonic acid group-modified metal oxide sol have a large molecular weight and a large molecular size. Also, the pores of the activated carbon are blocked, and there is a problem that the siloxane gas cannot be removed efficiently.

Also, activated carbon carrying ferrous sulfate and / or ferric sulfate is known as an adsorbent for siloxane compounds (for example, Patent Document 5). However, there is no specific description regarding activated carbon as a carrier. For example, even when ferrous sulfate and / or ferric sulfate is supported on general activated carbon, there is a problem that low desorption is not sufficient.

As described above, the present situation is that there is no siloxane removal agent that can efficiently remove siloxane gases and has excellent low desorption and a siloxane removal filter using the siloxane removal agent.

JP 2002-58997 A JP 2011-212565 A JP 2013-103153 A JP2013-103154A JP 60-222144 A

The present invention has been made against the background of the above-described prior art, and can efficiently remove siloxane gases and has a low detachability and a siloxane removal using the siloxane remover. The purpose is to provide a filter.

As a result of intensive studies to solve the above problems, the present inventors have finally completed the present invention. That is, the present invention is as follows.
1. In a siloxane remover in which an active compound or metal salt is supported on activated carbon in an amount of 0.1 to 20% by weight, the water adsorption amount at a temperature of 25 ° C. and a relative humidity of 40% is 25 ° C. and a relative humidity is 90%. A siloxane removing agent, wherein a water adsorption amount ratio divided by an amount of water adsorption at the time is 0.10 or more.
2. 2. The siloxane remover according to 1 above, wherein the acidic compound is a compound having an acid dissociation index (pKa) of 2.2 or less.
3. 2. The metal salt according to 1, wherein the metal salt is a trivalent metal element having a third ionization energy of 30 to 35 eV or a metal salt containing a tetravalent or higher metal element having a fourth ionization energy of 30 to 55 eV. Siloxane remover.
4). A siloxane removal filter comprising the siloxane remover according to any one of 1 to 3 above.
The acid dissociation index (pKa) is calculated from the acid dissociation constant (Ka) according to the following formula. The acid dissociation constant (Ka) refers to the acid dissociation constant (Ka) in water under normal temperature and normal pressure (25 ° C., 1 atm) conditions. If there are a plurality of acid dissociation indices (pKa), It refers to the smallest acid dissociation index (pKa).
pKa = -log ₁₀ Ka

The siloxane remover according to the present invention is a siloxane remover in which an active compound or metal salt is supported on activated carbon in an amount of 0.1 to 20% by weight, and the water adsorption amount at a temperature of 25 ° C. and a relative humidity of 40%. The water adsorption amount ratio obtained by dividing the amount by the water adsorption amount at a temperature of 25 ° C. and a relative humidity of 90% is 0.10 or more. The acidic compound has an acid dissociation index (pKa) of 2.2 or less, or the metal salt has a trivalent metal element having a third ionization energy of 30 to 35 eV, or has a fourth ionization energy of 30. Since it contains a tetravalent or higher-valent metal element of 55 eV, the siloxane gas can be efficiently removed, and there is an advantage of excellent low desorption.

Hereinafter, the present invention will be described in detail.
In the siloxane remover of the present invention, 0.1 to 20% by weight of an acidic compound or metal salt is supported on activated carbon, and the water adsorption amount at a temperature of 25 ° C. and a relative humidity of 40% is 25 ° C. The water adsorption amount ratio divided by the water adsorption amount at a humidity of 90% is 0.10 or more. Activated charcoal is loaded with 0.1 to 20% by weight of acidic compound or metal salt, and the amount of moisture adsorption when the siloxane remover is 25 ° C and 40% relative humidity is 25 ° C and 90% relative humidity. The present inventor has found that when the water adsorption amount ratio divided by 0.10 is 0.10 or more, the siloxane gas can be efficiently removed, and furthermore, the low desorption property is excellent.

Although the mechanism of the present invention is not clear, it is presumed as follows. First, (1) siloxane gases and water molecules are adsorbed on the activated carbon. Next, (2) the adsorbed siloxane gas reacts with a nearby acidic compound or metal salt to activate the siloxane gas. (3) The activated state of the activated siloxane gas is maintained by water molecules present in the vicinity thereof. Furthermore, (4) the activated siloxane gases react with each other or the activated siloxane gases react with the newly activated siloxane gases adsorbed on the activated carbon, so that the siloxane gases have a higher molecular weight. Converted to siloxane compounds. Since siloxane compounds having a large molecular weight have a high boiling point, it is considered that low detachability is improved.

In the siloxane remover, if the acidic compound or metal salt supported on the activated carbon is less than 0.1% by weight, the progress of (2) is slowed down, so that the desorption of siloxane gases is sufficiently suppressed. It is not possible. Further, if the acidic compound or metal salt supported on the activated carbon is larger than 20% by weight, the pores of the activated carbon are blocked by the supported acidic compound or metal salt, and the progress of the above (1) is slowed down. It is not possible to remove the similar gases efficiently.

If the water adsorption amount ratio obtained by dividing the water adsorption amount at a temperature of 25 ° C. and a relative humidity of 40% by the water adsorption amount at a temperature of 25 ° C. and a relative humidity of 90% is less than 0.10, Since 3) to (4) do not proceed, the desorption of the siloxane gas cannot be sufficiently suppressed. The upper limit of the moisture adsorption amount ratio is not particularly limited, but is preferably 0.4 or less, and more preferably 0.35 or less. If it is larger than 0.4, the adsorption of siloxane is inhibited by water molecules, and the above (1) does not proceed.

The BET specific surface area of the siloxane remover in the present invention is not particularly limited, but is preferably 200 to 3000 m ² / g. More preferably 600 ~ 1800m ² / g, still more preferably 1000 ~ 1600m ² / g. If the BET specific surface area is smaller than 200 m ² / g, the contact area with the siloxane gas is small, so that it cannot be efficiently removed. If the BET specific surface area is larger than 3000 m ² / g, it becomes difficult to produce activated carbon.

The pore volume of the siloxane remover in the present invention is not particularly limited, but is preferably 0.3 to 2.0 cc / g. It is more preferably 0.4 to 1.0 cc / g, and further preferably 0.5 to 1.0 cc / g. If the pore volume is smaller than 0.3 cc / g, the adsorption capacity of the siloxane gas becomes small and cannot be efficiently removed. If the pore volume is larger than 2.0 cc / g, production becomes extremely difficult.

The activated carbon in the present invention is not particularly limited, but is preferably obtained by hydrophilizing general activated carbon such as coconut shell activated carbon, coal activated carbon, wood activated carbon, synthetic resin activated carbon. Specific methods for hydrophilizing activated carbon include a method in which activated carbon is brought into contact with an oxidizing liquid such as nitric acid, a sodium hypochlorite aqueous solution, and a hydrogen peroxide solution, and an oxidizing gas such as oxygen, ozone, and nitrogen oxide. The method of making it contact is preferable. A method of contacting with nitric acid or a sodium hypochlorite aqueous solution is more preferable.

The acid dissociation index (pKa) of the acidic compound in the present invention is preferably 2.2 or less. This is because if the acid dissociation index (pKa) is larger than 2.2, the reaction between the siloxane gas adsorbed on the activated carbon and the acidic compound becomes slow, and a sufficiently low desorption property cannot be obtained. The lower limit of the acid dissociation index (pKa) is not particularly defined, but is preferably −10 or more. If it is −10 or less, the activated carbon may be dissolved.

The molecular weight of the acidic compound in the present invention is preferably 1000 or less. It is more preferably 500 or less, and further preferably 400 or less. This is because if the molecular weight is larger than 1000, the reaction between the siloxane gas adsorbed on the activated carbon and the acidic compound becomes slow, and a sufficiently low desorption property cannot be obtained. Examples of acidic compounds include oxalic acid (pKa = 1.23, molecular weight 90), maleic acid (pKa = 1.93, molecular weight 116), benzenehexacarboxylic acid (pKa = 1.40, molecular weight 342), benzenepenta Carboxylic acids such as carboxylic acid (pKa = 1.80, molecular weight 298), pyromellitic acid (pKa = 1.92, molecular weight 254), sulfurous acid (pKa = 1.90, molecular weight 82), sulfuric acid (pKa = -3. 00, molecular weight 98), phosphoric acid (pKa = 2.12, molecular weight 98), phosphorous acid (pKa = 2.00, molecular weight 82), hypophosphorous acid (pKa = 1.1, molecular weight 66), etc. inorganic Phosphoric acids such as acids, methyl phosphate (pKa = 1.54, molecular weight 112), dimethyl phosphate (pKa = 1.29, molecular weight 126), inosinic acid (pKa = 2.4, molecular weight 348) Amino acids such as esters, cysteine (pKa = 1.71, molecular weight 121), histidine (pKa = 1.82, molecular weight 155), p-toluenesulfonic acid (pKa = -2.80, molecular weight 172), benzenesulfone Sulphonic acids such as acids (pKa = -2.80, molecular weight 158) and the like and mixtures containing them are preferred. More preferred are inorganic acids, sulfonic acids and mixtures containing these which are relatively easily available. Sulfuric acid, phosphoric acid, p-toluenesulfonic acid, benzenesulfonic acid, and mixtures containing these, which are available at low cost, are further preferred.

The type of acidic compound in the present invention is not particularly limited, but is preferably liquid or solid under normal temperature and normal pressure (25 ° C., 1 atm) conditions. This is because if it is a gas at room temperature and normal pressure, it becomes difficult to support the activated carbon.

The acidic compound in the present invention preferably has a solubility of 1 g or more. If the solubility is less than 1 g, it becomes difficult to support an acidic compound on the activated carbon surface, and the siloxane gas desorption cannot be sufficiently suppressed. In addition, solubility here refers to the mass of the solute which melt | dissolves in 100 g of water at the temperature of 20 degreeC.

The method of supporting the acidic compound on the activated carbon in the present invention is not particularly limited, but the method of impregnating the aqueous solution of the acidic compound with activated carbon and then drying, or spraying the aqueous solution of the acidic compound in the form of mist / mist on the activated carbon Then, a method of drying is preferable.

The metal salt in the present invention preferably contains a trivalent metal element having a third ionization energy of 30 to 35 eV or a tetravalent or higher metal element having a fourth ionization energy of 30 to 55 eV. The third ionization energy of the trivalent metal element contained in the metal salt is less than 30 eV, the fourth ionization energy of the tetravalent or more metal element contained in the metal salt is less than 30 eV, or the metal element is trivalent or more. If it is not contained, the reaction between the siloxane gas adsorbed on the activated carbon and the metal salt becomes slow, and a sufficiently low desorption property cannot be obtained. If the third ionization energy of the trivalent metal element is larger than 35 eV, or the fourth ionization energy of the tetravalent or higher metal element is larger than 55 eV, handling becomes difficult from the viewpoint of safety.

The metal element in the present invention is preferably Ti, V, Mn, Fe, Co, Ga, or Zr from the viewpoint of cost and environmental pollution. Ti, Fe, Ga, or Zr is more preferable.

The type of metal salt in the present invention is not particularly limited, but is preferably liquid or solid under normal temperature and normal pressure (25 ° C., 1 atm) conditions. This is because if it is a gas at room temperature and normal pressure, it becomes difficult to support the activated carbon. Specifically, common salts such as sulfates, nitrates, phosphates, carbonates, bicarbonates, citrates, acetates and chlorides can be used, but chlorides or sulfates are more preferred. preferable.

The metal salt in the present invention preferably has a solubility of 1 g or more. If the solubility is less than 1 g, it becomes difficult to support the metal salt on the activated carbon surface, and the siloxane gas desorption cannot be sufficiently suppressed. In addition, solubility here refers to the mass of the solute which melt | dissolves in 100 g of water at the temperature of 20 degreeC.

The method for supporting the metal salt on the activated carbon in the present invention is not particularly limited, but the method of impregnating the activated carbon in an aqueous solution of the metal salt and then drying, or spraying the activated carbon in the form of a mist / mist of the aqueous metal salt Then, a method of drying is preferable.

In the present invention, the supported amount of the acidic compound or metal salt supported on the activated carbon is 0.1 to 20% by weight. It is preferably 1 to 15% by weight, and more preferably 1 to 10% by weight. If the loading is less than 0.1% by weight, the content of the acidic compound or metal salt is small, so that the siloxane gas can not be sufficiently eliminated. If the loading amount is greater than 20% by weight, the loading amount of the acidic compound or metal salt is large, so that the pores of the activated carbon are blocked and cannot be adsorbed efficiently.

The siloxane removal filter in the present invention preferably contains a siloxane remover. The method for producing the siloxane removal filter is not particularly limited, but a production method in which the sheet-like siloxane removal agent is processed into a planar shape, a pleated shape, or a honeycomb shape is preferable. When using a pleated shape as a direct flow filter, or when using a honeycomb shape as a parallel flow filter, the contact area with the gas to be treated is increased to improve removal efficiency, and the deodorizing filter has a low pressure loss. Can be achieved simultaneously.

The method for forming the siloxane remover in the present invention into a sheet is not particularly limited, and a conventionally known processing method can be used. For example, (a) a wet sheeting method obtained by dispersing and dehydrating siloxane remover particles together with sheet constituting fibers in water, and (b) airlaid obtained by dispersing siloxane remover particles together with sheet constituting fibers in the air. (C) A method in which a siloxane remover is filled between two or more layers of a nonwoven fabric or woven fabric, a net-like material, a film, and a film by thermal bonding, (d) an emulsion adhesive, a solvent-based adhesive is used. (E) Nonwoven fabrics, woven fabrics, urethane foams, etc. by utilizing the thermoplasticity of the base material, hot melt adhesive, etc. Use such as a method of bonding and supporting a siloxane remover on a breathable material, and a method of (f) mixing and integrating a siloxane remover into a fiber or resin. Suitable methods according can be used. It is preferable to use the processing methods (b), (c), and (e) because there is no need to use a surfactant, a water-soluble polymer, etc., and the pores of the porous body itself can be prevented. .

The siloxane remover and the siloxane removal filter in the present invention can be widely used for the purpose of reducing siloxane gases in indoors, in vehicles, wallpaper, furniture, interior materials, resin moldings, electrical equipment, and the like. In particular, it is preferably used for the purpose of removing siloxane gases contained in the air. For example, it is preferable to fill a granular material in a container such as a breathable box, bag, or net, and leave or aeration.

Hereinafter, the effects of the present invention will be described more specifically by way of examples. The following examples are not intended to limit the method of the present invention, and any design changes in accordance with the gist of the preceding and following descriptions are included in the technical scope of the present invention. In addition, the evaluation method of the characteristic value measured in the Example is shown below.

[Measurement method of BET specific surface area and total pore volume]
About 100 mg of a sample was taken, vacuum-dried at 120 ° C. for 24 hours, and then weighed. Using an automatic specific surface area device Gemini 2375 (manufactured by Micromeritics), the adsorption amount of nitrogen gas at the boiling point of liquid nitrogen (-195.8 ° C.) is gradually increased in a relative pressure range of 0.02 to 0.95. The sample was measured at 40 points while raising it to obtain an adsorption isotherm of the sample. With the analysis software (GEMINI-PCW version 1.01) attached to the automatic specific surface area device Gemini 2375, the surface area analysis range is set to 0.01 to 0.15 under the BET condition, and the BET specific surface area [m ² / g ] Was requested. Further, the total pore volume [cc / g] was determined from the data of the relative pressure 0.95.

[Measurement method of moisture adsorption ratio]
A 10 g sample was taken and vacuum-dried at 80 ° C. for 72 hours, and then the starting point weight [g] was measured. The sample was uniformly packed in a fixed bed flow type glass column having a temperature of 25 ° C. ± 0.5 ° C., and a steam / nitrogen mixed gas having a temperature of 25 ° C. and a relative humidity of 40% was passed through the column at 2 L / min. The sample weight was measured every 30 minutes, and when the weight change within 30 minutes was within 5 mg, the end point was determined, and the weight at that time was defined as the end point weight [g]. By dividing the difference between the end point weight and the start point weight by the start point weight, the moisture adsorption amount [mg / g] at a temperature of 25 ° C. and a relative humidity of 40% was calculated. Change the water vapor / nitrogen mixed gas flowing through the column to a temperature of 25 ° C. and a relative humidity of 90%, measure in the same way as above, and calculate the amount of moisture adsorbed [mg / g] at a temperature of 25 ° C. and a relative humidity of 90% Further, the water adsorption amount ratio [−] was calculated by dividing the water adsorption amount at a temperature of 25 ° C. and a relative humidity of 40% by the water adsorption amount at a temperature of 25 ° C. and a relative humidity of 90%.

[Measurement method of siloxane adsorption / desorption]
The sample classified to a particle diameter of 355 to 500 μm was filled in a glass tube having an inner diameter of 15 mmφ so that the thickness of the sample layer was 0.32 cm. To this, air having a temperature of 25 ° C. and a humidity of 50% RH containing 15 ppm of octamethylcyclotetrasiloxane (cyclic siloxane D4) was continuously circulated at 10 L / min. The gas at the inlet and outlet sides of the sample was sampled every minute, and the siloxane concentration was measured on a gas chromatograph with FID (GC-2014, manufactured by Shimadzu Corporation), and the removal rate [%] was calculated from the ratio. Distribution and concentration measurement were continued until the removal rate was 5% or less. By calculating the removal amount from the gas concentration difference between the inlet side and the outlet side of the sample, the flow rate passed through, and the temperature at the time of measurement, and dividing the time and removal amount curve by time, dividing by the sample weight, Siloxane adsorption capacity [mg / g] was calculated.
Next, about the sample which continued distribution | circulation and density | concentration measurement until this removal rate became 5% or less, the air of the temperature 25 degreeC and humidity 50% RH which do not contain siloxane was continuously distribute | circulated at 10 L / min, The gas on the outlet side was sampled every minute, and the siloxane concentration was measured for 20 minutes on a gas chromatograph with FID (GC-2014, manufactured by Shimadzu Corporation). By calculating the desorption amount from the gas concentration at the outlet side of the sample, the flow rate at which it was circulated, and the temperature at the time of measurement, and dividing the curve of time and desorption amount over time (20 minutes) by the sample weight The amount of siloxane desorption [mg / g] was calculated. The low desorption [−] was calculated by dividing the siloxane adsorption capacity [mg / g] by the siloxane desorption amount [mg / g].

<Example 1>
A nitric acid aqueous solution was prepared by mixing 5 g of nitric acid (1.38) (manufactured by Nacalai Tesque) and 12 g of ion-exchanged water. 3 g of coal-based activated carbon (BET specific surface area: 1460 m ² / g, total pore volume: 0.92 cc / g, particle size: 355 to 500 μm) was added to the prepared nitric acid aqueous solution and heated to about 100 ° C. Reflux treatment for hours was performed. After cooling to room temperature, it was filtered, washed 10 times with 100 ml of ion exchange water, and dried at 80 ° C. overnight. Furthermore, hydrophilicized activated carbon was obtained by treatment at 350 ° C. for 4 hours in an air atmosphere.
25 mg of p-toluenesulfonic acid (manufactured by Wako Pure Chemical Industries, Ltd., molecular weight 172, pKa = −2.80, solubility 67 g) was dissolved in 650 mg of ion-exchanged water, and the aqueous solution and 475 mg of hydrophilized activated carbon were mixed with stirring. Thereafter, drying was performed at 80 ° C. for 6 hours, followed by classification to obtain a sample carrying 5% by weight of p-toluenesulfonic acid having a particle diameter of 355 to 500 μm. The obtained sample was subjected to BET specific surface area, total pore volume measurement, moisture adsorption amount ratio measurement, and siloxane adsorption / desorption measurement.

<Example 2>
A nitric acid aqueous solution was prepared by mixing 5 g of nitric acid (1.38) (manufactured by Nacalai Tesque) and 12 g of ion-exchanged water. 3 g of coconut shell activated carbon (BET specific surface area: 1880 m ² / g, total pore volume: 0.83 cc / g, particle size: 355 to 500 μm) was added to the prepared nitric acid aqueous solution and heated to about 100 ° C. Reflux treatment for hours was performed. After cooling to room temperature, it was filtered, washed 10 times with 100 ml of ion exchange water, and dried at 80 ° C. overnight. Furthermore, hydrophilicized activated carbon was obtained by treatment at 350 ° C. for 4 hours in an air atmosphere.
25 mg of p-toluenesulfonic acid (manufactured by Wako Pure Chemical Industries, Ltd., molecular weight 172, pKa = -2.80, solubility 67 g) was dissolved in 450 mg of ion-exchanged water, and the aqueous solution and 475 mg of hydrophilic activated carbon were mixed with stirring. Thereafter, drying was performed at 80 ° C. for 6 hours, followed by classification to obtain a sample carrying 5% by weight of p-toluenesulfonic acid having a particle diameter of 355 to 500 μm. The obtained sample was subjected to BET specific surface area, total pore volume measurement, moisture adsorption amount ratio measurement, and siloxane adsorption / desorption measurement.

<Example 3>
1 g of nitric acid (1.38) (manufactured by Nacalai Tesque) and 12 g of ion-exchanged water were mixed to prepare an aqueous nitric acid solution. 3 g of coconut shell activated carbon (BET specific surface area: 1880 m ² / g, total pore volume: 0.83 cc / g, particle size: 355 to 500 μm) was added to the prepared nitric acid aqueous solution and then treated at room temperature for 4 hours. . Thereafter, the mixture was filtered, washed 10 times with 100 ml of ion-exchanged water, and dried at 80 ° C. overnight. Furthermore, hydrophilicized activated carbon was obtained by treatment at 350 ° C. for 4 hours in an air atmosphere.
25 mg of p-toluenesulfonic acid (manufactured by Wako Pure Chemical Industries, Ltd., molecular weight 172, pKa = -2.80, solubility 67 g) was dissolved in 450 mg of ion-exchanged water, and the aqueous solution and 475 mg of hydrophilic activated carbon were mixed with stirring. Thereafter, drying was performed at 80 ° C. for 6 hours, followed by classification to obtain a sample carrying 5% by weight of p-toluenesulfonic acid having a particle diameter of 355 to 500 μm. The obtained sample was subjected to BET specific surface area, total pore volume measurement, moisture adsorption amount ratio measurement, and siloxane adsorption / desorption measurement.

<Example 4>
1 g of nitric acid (1.38) (manufactured by Nacalai Tesque) and 12 g of ion-exchanged water were mixed to prepare an aqueous nitric acid solution. 3 g of coconut shell activated carbon (BET specific surface area: 1880 m ² / g, total pore volume: 0.83 cc / g, particle size: 355 to 500 μm) was added to the prepared nitric acid aqueous solution and then treated at room temperature for 4 hours. . Thereafter, the mixture was filtered, washed 10 times with 100 ml of ion-exchanged water, and dried at 80 ° C. overnight. Furthermore, hydrophilicized activated carbon was obtained by treatment at 350 ° C. for 4 hours in an air atmosphere.
25 mg of concentrated sulfuric acid (manufactured by Wako Pure Chemical Industries, Ltd., molecular weight 98, pKa = −3.00, solubility 200 g or more) was dissolved in 450 mg of ion-exchanged water, and the aqueous solution and 475 mg of hydrophilized activated carbon were mixed with stirring. Thereafter, after drying at 80 ° C. for 6 hours, classification was carried out to obtain a 5% by weight sulfuric acid loaded sample having a particle diameter of 355 to 500 μm. The obtained sample was subjected to BET specific surface area, total pore volume measurement, moisture adsorption amount ratio measurement, and siloxane adsorption / desorption measurement.

<Example 5>
1 g of nitric acid (1.38) (manufactured by Nacalai Tesque) and 12 g of ion-exchanged water were mixed to prepare an aqueous nitric acid solution. 3 g of coconut shell activated carbon (BET specific surface area: 1880 m ² / g, total pore volume: 0.83 cc / g, particle size: 355 to 500 μm) was added to the prepared nitric acid aqueous solution and then treated at room temperature for 4 hours. . Thereafter, the mixture was filtered, washed 10 times with 100 ml of ion-exchanged water, and dried at 80 ° C. overnight. Furthermore, hydrophilicized activated carbon was obtained by treatment at 350 ° C. for 4 hours in an air atmosphere.
25 mg of oxalic acid (manufactured by Wako Pure Chemical Industries, molecular weight 90, pKa = 1.23, solubility 10.2 g) was dissolved in 450 mg of ion-exchanged water, and the aqueous solution and 475 mg of hydrophilic activated carbon were mixed with stirring. Thereafter, after drying at 80 ° C. for 6 hours, classification was performed to obtain a sample carrying 5% by weight of oxalic acid having a particle diameter of 355 to 500 μm. The obtained sample was subjected to BET specific surface area, total pore volume measurement, moisture adsorption amount ratio measurement, and siloxane adsorption / desorption measurement.

<Example 6>
1 g of nitric acid (1.38) (manufactured by Nacalai Tesque) and 12 g of ion-exchanged water were mixed to prepare an aqueous nitric acid solution. 3 g of coconut shell activated carbon (BET specific surface area: 1880 m ² / g, total pore volume: 0.83 cc / g, particle size: 355 to 500 μm) was added to the prepared nitric acid aqueous solution and then treated at room temperature for 4 hours. . Thereafter, the mixture was filtered, washed 10 times with 100 ml of ion-exchanged water, and dried at 80 ° C. overnight. Furthermore, hydrophilicized activated carbon was obtained by treatment at 350 ° C. for 4 hours in an air atmosphere.
25 mg of benzenehexacarboxylic acid (manufactured by Tokyo Chemical Industry, molecular weight 342, pKa = 1.40, solubility of 10 g or more) was dissolved in 450 mg of ion-exchanged water, and the aqueous solution and 475 mg of hydrophilicized activated carbon were mixed with stirring. Thereafter, drying was performed at 80 ° C. for 6 hours, followed by classification to obtain a sample carrying 5% by weight of benzenehexacarboxylic acid having a particle diameter of 355 to 500 μm. The obtained sample was subjected to BET specific surface area, total pore volume measurement, moisture adsorption amount ratio measurement, and siloxane adsorption / desorption measurement.

<Example 7>
1 g of nitric acid (1.38) (manufactured by Nacalai Tesque) and 12 g of ion-exchanged water were mixed to prepare an aqueous nitric acid solution. 3 g of coconut shell activated carbon (BET specific surface area: 1880 m ² / g, total pore volume: 0.83 cc / g, particle size: 355 to 500 μm) was added to the prepared nitric acid aqueous solution and then treated at room temperature for 4 hours. . Thereafter, the mixture was filtered, washed 10 times with 100 ml of ion-exchanged water, and dried at 80 ° C. overnight. Furthermore, hydrophilicized activated carbon was obtained by treatment at 350 ° C. for 4 hours in an air atmosphere.
25 mg of phosphoric acid (manufactured by Wako Pure Chemical Industries, molecular weight 98, pKa = 2.12, solubility of 200 g or more) was dissolved in 450 mg of ion-exchanged water, and the aqueous solution and 475 mg of hydrophilic activated carbon were mixed with stirring. Thereafter, the sample was dried at 80 ° C. for 6 hours and classified to obtain a sample carrying 5% by weight of phosphoric acid having a particle diameter of 355 to 500 μm. The obtained sample was subjected to BET specific surface area, total pore volume measurement, moisture adsorption amount ratio measurement, and siloxane adsorption / desorption measurement.

<Example 8>
A nitric acid aqueous solution was prepared by mixing 0.1 g of nitric acid (1.38) (manufactured by Nacalai Tesque) and 12 g of ion-exchanged water. 3 g of coconut shell activated carbon (BET specific surface area: 1880 m ² / g, total pore volume: 0.83 cc / g, particle size: 355 to 500 μm) was added to the prepared nitric acid aqueous solution and then treated at room temperature for 4 hours. . Thereafter, the resultant was filtered, washed 10 times with 100 ml of ion-exchanged water, and dried at 80 ° C. overnight to obtain hydrophilic activated carbon.
50 mg of p-toluenesulfonic acid (manufactured by Wako Pure Chemical Industries, Ltd., molecular weight 172, pKa = −2.80, solubility 67 g) was dissolved in 420 mg of ion-exchanged water, and the aqueous solution and 450 mg of hydrophilic activated carbon were mixed with stirring. Thereafter, after drying at 80 ° C. for 6 hours, classification was performed to obtain a sample carrying 10% by weight of p-toluenesulfonic acid having a particle diameter of 355 to 500 μm. The obtained sample was subjected to BET specific surface area, total pore volume measurement, moisture adsorption amount ratio measurement, and siloxane adsorption / desorption measurement.

<Example 9>
A sodium hypochlorite aqueous solution was prepared by mixing 1.4 g of sodium hypochlorite solution (manufactured by Wako Pure Chemical Industries) and 1.4 g of ion-exchanged water. 3 g of coconut shell activated carbon (BET specific surface area: 1880 m ² / g, total pore volume: 0.83 cc / g, particle size: 355 to 500 μm) and the prepared sodium hypochlorite aqueous solution were stirred and mixed. Then, the activated carbon hydrophilized by drying at 80 degreeC overnight was obtained.
50 mg of p-toluenesulfonic acid (manufactured by Wako Pure Chemical Industries, Ltd., molecular weight 172, pKa = −2.80, solubility 67 g) was dissolved in 420 mg of ion-exchanged water, and the aqueous solution and 450 mg of hydrophilic activated carbon were mixed with stirring. Thereafter, after drying at 80 ° C. for 6 hours, classification was performed to obtain a sample carrying 10% by weight of p-toluenesulfonic acid having a particle diameter of 355 to 500 μm. The obtained sample was subjected to BET specific surface area, total pore volume measurement, moisture adsorption amount ratio measurement, and siloxane adsorption / desorption measurement.

<Comparative Example 1>
Coal activated carbon (BET specific surface area: 1460 m ² / g, total pore volume: 0.92 cc / g, particle size: 355 to 500 μm) BET specific surface area, total pore volume measurement, moisture adsorption ratio measurement, siloxane adsorption / Desorption measurement was performed.

<Comparative example 2>
3 g of coal-based activated carbon (BET specific surface area: 1460 m ² / g, total pore volume: 0.92 cc / g, particle size: 355 to 500 μm) is put into 50 ml of 0.1 mol / L hydrochloric acid and stirred for 12 hours. It was. Thereafter, the mixture was filtered, washed 5 times with 100 ml of ion-exchanged water, and dried at 80 ° C. overnight. The obtained sample was subjected to BET specific surface area measurement, total pore volume measurement, moisture adsorption amount ratio measurement, and siloxane adsorption / desorption measurement.

<Comparative Example 3>
25 mg of p-toluenesulfonic acid (manufactured by Wako Pure Chemical Industries, Ltd., molecular weight 172, pKa = −2.80, solubility 67 g) is dissolved in 650 mg of ion-exchanged water, and the aqueous solution and coal-based activated carbon (BET specific surface area: 1460 m ² / g). 475 mg), the total pore volume: 0.92 cc / g, particle size: 355 to 500 μm). Thereafter, drying was performed at 80 ° C. for 6 hours, followed by classification to obtain a sample carrying 5% by weight of p-toluenesulfonic acid having a particle diameter of 355 to 500 μm. The obtained sample was subjected to BET specific surface area, total pore volume measurement, moisture adsorption amount ratio measurement, and siloxane adsorption / desorption measurement.

<Comparative example 4>
350 mg of Nafion 10% dispersion DE1021 (manufactured by Wako Pure Chemical Industries, Ltd., molecular weight 1000 to 10000, pKa = -3.10) was mixed with 300 mg of ion-exchanged water, and the mixed solution and coal-based activated carbon (BET specific surface area: 1460 m ² / g, total pore volume: 0.92 cc / g, particle size: 355 to 500 μm) and 475 mg were mixed with stirring. Thereafter, after drying at 80 ° C. for 6 hours, classification was carried out to obtain a sample carrying 5% by weight of Nafion having a particle diameter of 355 to 500 μm. The obtained sample was subjected to BET specific surface area, total pore volume measurement, moisture adsorption amount ratio measurement, and siloxane adsorption / desorption measurement.

Tables 1 and 2 show the results of BET specific surface area measurement, total pore volume measurement, moisture adsorption amount ratio measurement, and siloxane adsorption / desorption measurement for Examples 1 to 9 and Comparative Examples 1 to 4. As is clear from Tables 1 and 2, Examples 1 to 9 according to the present invention are less desorbable than the case where the water adsorption amount ratio is less than 0.10 (Comparative Examples 1 to 4). It turns out that it is excellent.

<Example 10>
A nitric acid aqueous solution was prepared by mixing 5 g of nitric acid (1.38) (manufactured by Nacalai Tesque) and 12 g of ion-exchanged water. 3 g of coal-based activated carbon (BET specific surface area: 1460 m ² / g, total pore volume: 0.92 cc / g, particle size: 355 to 500 μm) was added to the prepared nitric acid aqueous solution and heated to about 100 ° C. Reflux treatment for hours was performed. After cooling to room temperature, it was filtered, washed 10 times with 100 ml of ion exchange water, and dried at 80 ° C. overnight. Furthermore, hydrophilicized activated carbon was obtained by treatment at 350 ° C. for 4 hours in an air atmosphere.
2 mg of p-toluenesulfonic acid (manufactured by Wako Pure Chemical Industries, Ltd., molecular weight 172, pKa = −2.80, solubility 67 g) was dissolved in 1380 mg of ion-exchanged water, and the aqueous solution and 998 mg of hydrophilic activated carbon were mixed with stirring. Thereafter, drying was performed at 80 ° C. for 6 hours, followed by classification to obtain a 0.2% by weight p-toluenesulfonic acid carrying sample having a particle diameter of 355 to 500 μm. The obtained sample was subjected to BET specific surface area, total pore volume measurement, moisture adsorption amount ratio measurement, and siloxane adsorption / desorption measurement.

<Example 11>
A nitric acid aqueous solution was prepared by mixing 5 g of nitric acid (1.38) (manufactured by Nacalai Tesque) and 12 g of ion-exchanged water. 3 g of coal-based activated carbon (BET specific surface area: 1460 m ² / g, total pore volume: 0.92 cc / g, particle size: 355 to 500 μm) was added to the prepared nitric acid aqueous solution and heated to about 100 ° C. Reflux treatment for hours was performed. After cooling to room temperature, it was filtered, washed 10 times with 100 ml of ion exchange water, and dried at 80 ° C. overnight. Furthermore, hydrophilicized activated carbon was obtained by treatment at 350 ° C. for 4 hours in an air atmosphere.
20 mg of p-toluenesulfonic acid (manufactured by Wako Pure Chemical Industries, Ltd., molecular weight 172, pKa = -2.80, solubility 67 g) was dissolved in 1350 mg of ion-exchanged water, and the aqueous solution and 980 mg of hydrophilized activated carbon were mixed with stirring. Thereafter, after drying at 80 ° C. for 6 hours, classification was performed to obtain a sample carrying 2% by weight of p-toluenesulfonic acid having a particle diameter of 355 to 500 μm. The obtained sample was subjected to BET specific surface area, total pore volume measurement, moisture adsorption amount ratio measurement, and siloxane adsorption / desorption measurement.

<Example 12>
A nitric acid aqueous solution was prepared by mixing 5 g of nitric acid (1.38) (manufactured by Nacalai Tesque) and 12 g of ion-exchanged water. 3 g of coal-based activated carbon (BET specific surface area: 1460 m ² / g, total pore volume: 0.92 cc / g, particle size: 355 to 500 μm) was added to the prepared nitric acid aqueous solution and heated to about 100 ° C. Reflux treatment for hours was performed. After cooling to room temperature, it was filtered, washed 10 times with 100 ml of ion exchange water, and dried at 80 ° C. overnight. Furthermore, hydrophilicized activated carbon was obtained by treatment at 350 ° C. for 4 hours in an air atmosphere.
100 mg of p-toluenesulfonic acid (manufactured by Wako Pure Chemical Industries, Ltd., molecular weight 172, pKa = −2.80, solubility 67 g) was dissolved in 1240 mg of ion-exchanged water, and the aqueous solution and 900 mg of hydrophilic activated carbon were mixed with stirring. Thereafter, after drying at 80 ° C. for 6 hours, classification was performed to obtain a sample carrying 10% by weight of p-toluenesulfonic acid having a particle diameter of 355 to 500 μm. The obtained sample was subjected to BET specific surface area, total pore volume measurement, moisture adsorption amount ratio measurement, and siloxane adsorption / desorption measurement.

<Example 13>
A nitric acid aqueous solution was prepared by mixing 5 g of nitric acid (1.38) (manufactured by Nacalai Tesque) and 12 g of ion-exchanged water. 3 g of coal-based activated carbon (BET specific surface area: 1460 m ² / g, total pore volume: 0.92 cc / g, particle size: 355 to 500 μm) was added to the prepared nitric acid aqueous solution and heated to about 100 ° C. Reflux treatment for hours was performed. After cooling to room temperature, it was filtered, washed 10 times with 100 ml of ion exchange water, and dried at 80 ° C. overnight. Furthermore, hydrophilicized activated carbon was obtained by treatment at 350 ° C. for 4 hours in an air atmosphere.
150 mg of p-toluenesulfonic acid (manufactured by Wako Pure Chemical Industries, Ltd., molecular weight 172, pKa = -2.80, solubility 67 g) was dissolved in 1170 mg of ion-exchanged water, and the aqueous solution and 850 mg of hydrophilic activated carbon were mixed with stirring. Thereafter, after drying at 80 ° C. for 6 hours, classification was performed to obtain a sample carrying 15% by weight of p-toluenesulfonic acid having a particle diameter of 355 to 500 μm. The obtained sample was subjected to BET specific surface area, total pore volume measurement, moisture adsorption amount ratio measurement, and siloxane adsorption / desorption measurement.

<Example 14>
A nitric acid aqueous solution was prepared by mixing 5 g of nitric acid (1.38) (manufactured by Nacalai Tesque) and 12 g of ion-exchanged water. 3 g of coal-based activated carbon (BET specific surface area: 1460 m ² / g, total pore volume: 0.92 cc / g, particle size: 355 to 500 μm) was added to the prepared nitric acid aqueous solution and heated to about 100 ° C. Reflux treatment for hours was performed. After cooling to room temperature, it was filtered, washed 10 times with 100 ml of ion exchange water, and dried at 80 ° C. overnight. Furthermore, hydrophilicized activated carbon was obtained by treatment at 350 ° C. for 4 hours in an air atmosphere.
200 mg of p-toluenesulfonic acid (manufactured by Wako Pure Chemical Industries, Ltd., molecular weight 172, pKa = -2.80, solubility 67 g) was dissolved in 1100 mg of ion-exchanged water, and the aqueous solution and 800 mg of hydrophilized activated carbon were mixed with stirring. Thereafter, after drying at 80 ° C. for 6 hours, classification was performed to obtain a sample carrying 20% by weight of p-toluenesulfonic acid having a particle diameter of 355 to 500 μm. The obtained sample was subjected to BET specific surface area, total pore volume measurement, moisture adsorption amount ratio measurement, and siloxane adsorption / desorption measurement.

<Comparative Example 5>
Concentrated nitric acid (manufactured by Nacalai Tesque) 5 g and ion-exchanged water 12 g were mixed to prepare an aqueous nitric acid solution. 3 g of coal-based activated carbon (BET specific surface area: 1460 m ² / g, total pore volume: 0.92 cc / g, particle size: 355 to 500 μm) was added to the prepared nitric acid aqueous solution, then heated and refluxed for 4 hours. Went. After cooling to room temperature, it was filtered, washed 10 times with 100 ml of ion exchange water, and dried at 80 ° C. overnight. Furthermore, hydrophilicized activated carbon was obtained by treatment at 350 ° C. for 4 hours in an air atmosphere. The obtained sample was subjected to BET specific surface area, total pore volume measurement, moisture adsorption amount ratio measurement, and siloxane adsorption / desorption measurement.

<Comparative Example 6>
A nitric acid aqueous solution was prepared by mixing 5 g of nitric acid (1.38) (manufactured by Nacalai Tesque) and 12 g of ion-exchanged water. 3 g of coal-based activated carbon (BET specific surface area: 1460 m ² / g, total pore volume: 0.92 cc / g, particle size: 355 to 500 μm) was added to the prepared nitric acid aqueous solution and heated to about 100 ° C. Reflux treatment for hours was performed. After cooling to room temperature, it was filtered, washed 10 times with 100 ml of ion exchange water, and dried at 80 ° C. overnight. Furthermore, hydrophilicized activated carbon was obtained by treatment at 350 ° C. for 4 hours in an air atmosphere.
300 mg of p-toluenesulfonic acid (manufactured by Wako Pure Chemical Industries, Ltd., molecular weight 172, pKa = -2.80, solubility 67 g) was dissolved in 970 mg of ion-exchanged water, and the aqueous solution and 700 mg of hydrophilized activated carbon were mixed with stirring. Thereafter, after drying at 80 ° C. for 6 hours, classification was performed to obtain a sample carrying 30% by weight of p-toluenesulfonic acid having a particle diameter of 355 to 500 μm. The obtained sample was subjected to BET specific surface area, total pore volume measurement, moisture adsorption amount ratio measurement, and siloxane adsorption / desorption measurement.

Table 3 shows the results of BET specific surface area, total pore volume measurement, moisture adsorption amount ratio measurement, and siloxane adsorption / desorption measurement for Examples 1, 10 to 14, and Comparative Examples 5 to 6. As is apparent from Table 3, Example 1 and Examples 10 to 14 of the present invention have no acidic compound supported (Comparative Example 5), and the amount of acidic compound supported is 20% by weight. It can be seen that it is excellent in low detachability as compared with the case of larger than (Comparative Example 6).

<Example 15>
A nitric acid aqueous solution was prepared by mixing 5 g of nitric acid (1.38) (manufactured by Nacalai Tesque) and 12 g of ion-exchanged water. 3 g of coconut shell activated carbon (BET specific surface area: 1880 m ² / g, total pore volume: 0.83 cc / g, particle size: 355 to 500 μm) was added to the prepared nitric acid aqueous solution and heated to about 100 ° C. Reflux treatment for hours was performed. After cooling to room temperature, it was filtered, washed 10 times with 100 ml of ion exchange water, and dried at 80 ° C. overnight. Furthermore, hydrophilicized activated carbon was obtained by treatment at 350 ° C. for 4 hours in an air atmosphere.
25 mg of iron (III) sulfate n hydrate (manufactured by Wako Pure Chemical Industries, solubility of 246 g at 0 ° C.) was dissolved in 650 mg of ion-exchanged water, and the aqueous solution and 475 mg of hydrophilized activated carbon were mixed with stirring. Thereafter, drying was performed at 80 ° C. for 6 hours, followed by classification to obtain a 5% by weight iron (III) sulfate-supporting sample having a particle diameter of 355 to 500 μm. The obtained sample was subjected to BET specific surface area, total pore volume measurement, moisture adsorption amount ratio measurement, and siloxane adsorption / desorption measurement.

<Example 16>
A nitric acid aqueous solution was prepared by mixing 5 g of nitric acid (1.38) (manufactured by Nacalai Tesque) and 12 g of ion-exchanged water. 3 g of coal-based activated carbon (BET specific surface area: 1460 m ² / g, total pore volume: 0.92 cc / g, particle size: 355 to 500 μm) was added to the prepared nitric acid aqueous solution and heated to about 100 ° C. Reflux treatment for hours was performed. After cooling to room temperature, it was filtered, washed 10 times with 100 ml of ion exchange water, and dried at 80 ° C. overnight. Furthermore, hydrophilicized activated carbon was obtained by treatment at 350 ° C. for 4 hours in an air atmosphere.
25 mg of iron (III) sulfate n hydrate (manufactured by Wako Pure Chemical Industries, solubility of 246 g at 0 ° C.) was dissolved in 650 mg of ion-exchanged water, and the aqueous solution and 475 mg of hydrophilized activated carbon were mixed with stirring. Thereafter, the sample was dried at 80 ° C. for 6 hours and then classified to obtain a 5 wt% iron (III) sulfate loaded sample having a particle diameter of 355 to 500 μm. The obtained sample was subjected to BET specific surface area, total pore volume measurement, moisture adsorption amount ratio measurement, and siloxane adsorption / desorption measurement.

<Example 17>
A sodium hypochlorite aqueous solution was prepared by mixing 1.4 g of sodium hypochlorite solution (manufactured by Wako Pure Chemical Industries) and 1.4 g of ion-exchanged water. 3 g of coconut shell activated carbon (BET specific surface area: 1880 m ² / g, total pore volume: 0.83 cc / g, particle size: 355 to 500 μm) and the prepared sodium hypochlorite aqueous solution were stirred and mixed. Thereafter, washing was performed 5 times with 100 ml of ion-exchanged water, followed by drying at 80 ° C. overnight to obtain a hydrophilic activated carbon.
25 mg of iron (III) sulfate n hydrate (manufactured by Wako Pure Chemical Industries, solubility of 246 g at 0 ° C.) was dissolved in 650 mg of ion-exchanged water, and the aqueous solution and 475 mg of hydrophilized activated carbon were mixed with stirring. Thereafter, the sample was dried at 80 ° C. for 6 hours and then classified to obtain a 5 wt% iron (III) sulfate loaded sample having a particle diameter of 355 to 500 μm. The obtained sample was subjected to BET specific surface area, total pore volume measurement, moisture adsorption amount ratio measurement, and siloxane adsorption / desorption measurement.

<Example 18>
1 g of nitric acid (1.38) (manufactured by Nacalai Tesque) and 12 g of ion-exchanged water were mixed to prepare an aqueous nitric acid solution. After charging 3 g of coal-based activated carbon (BET specific surface area: 1460 m ² / g, total pore volume: 0.92 cc / g, particle size: 355 to 500 μm), the mixture was treated at room temperature for 4 hours. . Thereafter, the mixture was filtered, washed 10 times with 100 ml of ion-exchanged water, and dried at 80 ° C. overnight. Furthermore, hydrophilicized activated carbon was obtained by treatment at 350 ° C. for 4 hours in an air atmosphere.
25 mg of iron (III) sulfate n hydrate (manufactured by Wako Pure Chemical Industries, solubility of 246 g at 0 ° C.) was dissolved in 650 mg of ion-exchanged water, and the aqueous solution and 475 mg of hydrophilized activated carbon were mixed with stirring. Thereafter, drying was performed at 80 ° C. for 6 hours, followed by classification to obtain a 5% by weight iron (III) sulfate-supporting sample having a particle diameter of 355 to 500 μm. The obtained sample was subjected to BET specific surface area, total pore volume measurement, moisture adsorption amount ratio measurement, and siloxane adsorption / desorption measurement.

<Example 19>
1 g of nitric acid (1.38) (manufactured by Nacalai Tesque) and 12 g of ion-exchanged water were mixed to prepare an aqueous nitric acid solution. After charging 3 g of coal-based activated carbon (BET specific surface area: 1460 m ² / g, total pore volume: 0.92 cc / g, particle size: 355 to 500 μm), the mixture was treated at room temperature for 4 hours. . Thereafter, the mixture was filtered, washed 10 times with 100 ml of ion-exchanged water, and dried at 80 ° C. overnight. Furthermore, hydrophilicized activated carbon was obtained by treatment at 350 ° C. for 4 hours in an air atmosphere.
25 mg of hexaamminecobalt (III) chloride (manufactured by Wako Pure Chemical Industries, solubility 26 g or more) was dissolved in 650 mg of ion-exchanged water, and the aqueous solution and 475 mg of hydrophilic activated carbon were mixed with stirring. Thereafter, the sample was dried at 80 ° C. for 6 hours and then classified to obtain a sample containing 5% by weight of hexaamminecobalt (III) chloride having a particle diameter of 355 to 500 μm. The obtained sample was subjected to BET specific surface area, total pore volume measurement, moisture adsorption amount ratio measurement, and siloxane adsorption / desorption measurement.

<Example 20>
1 g of nitric acid (1.38) (manufactured by Nacalai Tesque) and 12 g of ion-exchanged water were mixed to prepare an aqueous nitric acid solution. After charging 3 g of coal-based activated carbon (BET specific surface area: 1460 m ² / g, total pore volume: 0.92 cc / g, particle size: 355 to 500 μm), the mixture was treated at room temperature for 4 hours. . Thereafter, the mixture was filtered, washed 10 times with 100 ml of ion-exchanged water, and dried at 80 ° C. overnight. Furthermore, hydrophilicized activated carbon was obtained by treatment at 350 ° C. for 4 hours in an air atmosphere.
25 mg of gallium sulfate (III) hydrate (manufactured by Wako Pure Chemical Industries, solubility of 18 g or more) was dissolved in 650 mg of ion-exchanged water, and the aqueous solution and 475 mg of hydrophilic activated carbon were mixed with stirring. Then, after drying at 80 ° C. for 6 hours, classification was performed to obtain a sample carrying 5% by weight of gallium (III) sulfate having a particle diameter of 355 to 500 μm. The obtained sample was subjected to BET specific surface area, total pore volume measurement, moisture adsorption amount ratio measurement, and siloxane adsorption / desorption measurement.

<Example 21>
1 g of nitric acid (1.38) (manufactured by Nacalai Tesque) and 12 g of ion-exchanged water were mixed to prepare an aqueous nitric acid solution. After charging 3 g of coal-based activated carbon (BET specific surface area: 1460 m ² / g, total pore volume: 0.92 cc / g, particle size: 355 to 500 μm), the mixture was treated at room temperature for 4 hours. . Thereafter, the mixture was filtered, washed 10 times with 100 ml of ion-exchanged water, and dried at 80 ° C. overnight. Furthermore, hydrophilicized activated carbon was obtained by treatment at 350 ° C. for 4 hours in an air atmosphere.
25 mg of zirconium sulfate (IV) tetrahydrate (manufactured by Wako Pure Chemical Industries, solubility of 52 g at 18 ° C.) was dissolved in 650 mg of ion-exchanged water, and the aqueous solution and 475 mg of hydrophilic activated carbon were mixed with stirring. Thereafter, drying was performed at 80 ° C. for 6 hours, followed by classification to obtain a sample carrying 5% by weight of zirconium (IV) sulfate having a particle diameter of 355 to 500 μm. The obtained sample was subjected to BET specific surface area, total pore volume measurement, moisture adsorption amount ratio measurement, and siloxane adsorption / desorption measurement.

<Example 22>
1 g of nitric acid (1.38) (manufactured by Nacalai Tesque) and 12 g of ion-exchanged water were mixed to prepare an aqueous nitric acid solution. After charging 3 g of coal-based activated carbon (BET specific surface area: 1460 m ² / g, total pore volume: 0.92 cc / g, particle size: 355 to 500 μm), the mixture was treated at room temperature for 4 hours. . Thereafter, the mixture was filtered, washed 10 times with 100 ml of ion-exchanged water, and dried at 80 ° C. overnight. Furthermore, hydrophilicized activated carbon was obtained by treatment at 350 ° C. for 4 hours in an air atmosphere.
25 mg of a solution containing 24% titanium sulfate (IV, manufactured by Kishida Chemical Co., Ltd., solubility of 10 g or more) was dissolved in 650 mg of ion-exchanged water, and the aqueous solution and 475 mg of hydrophilic activated carbon were mixed with stirring. Thereafter, the sample was dried at 80 ° C. for 6 hours, followed by classification to obtain a 5 wt% titanium (IV) sulfate loaded sample having a particle diameter of 355 to 500 μm. The obtained sample was subjected to BET specific surface area, total pore volume measurement, moisture adsorption amount ratio measurement, and siloxane adsorption / desorption measurement.

<Example 23>
1 g of nitric acid (1.38) (manufactured by Nacalai Tesque) and 12 g of ion-exchanged water were mixed to prepare an aqueous nitric acid solution. After charging 3 g of coal-based activated carbon (BET specific surface area: 1460 m ² / g, total pore volume: 0.92 cc / g, particle size: 355 to 500 μm), the mixture was treated at room temperature for 4 hours. . Thereafter, the mixture was filtered, washed 10 times with 100 ml of ion-exchanged water, and dried at 80 ° C. overnight. Furthermore, hydrophilicized activated carbon was obtained by treatment at 350 ° C. for 4 hours in an air atmosphere.
25 mg of potassium permanganate (manufactured by Wako Pure Chemical Industries, solubility: 7.5 g) was dissolved in 650 mg of ion-exchanged water, and the aqueous solution and 475 mg of hydrophilic activated carbon were mixed with stirring. Thereafter, the sample was dried at 80 ° C. for 6 hours and then classified to obtain a sample having 5% by weight of potassium permanganate having a particle diameter of 355 to 500 μm. The obtained sample was subjected to BET specific surface area, total pore volume measurement, moisture adsorption amount ratio measurement, and siloxane adsorption / desorption measurement.

<Comparative Example 7>
25 mg of iron (II) sulfate heptahydrate (manufactured by Wako Pure Chemical Industries, solubility 25 g) is dissolved in 650 mg of ion-exchanged water, and the aqueous solution and coal-based activated carbon (BET specific surface area: 1460 m ² / g, total pore volume: 475 mg) (0.92 cc / g, particle size: 355 to 500 μm) was stirred and mixed. Then, after drying for 6 hours under a nitrogen atmosphere at 80 ° C., classification was performed to obtain a 5 wt% iron (II) sulfate loaded sample having a particle diameter of 355 to 500 μm. The obtained sample was subjected to BET specific surface area, total pore volume measurement, moisture adsorption amount ratio measurement, and siloxane adsorption / desorption measurement.

<Comparative Example 8>
25 mg of aluminum sulfate (manufactured by Wako Pure Chemical Industries, solubility: 100 g) is dissolved in 650 mg of ion-exchanged water, and the aqueous solution and coal-based activated carbon (BET specific surface area: 1460 m ² / g, total pore volume: 0.92 cc / g, granules (Diameter: 355 to 500 μm) and 475 mg were mixed with stirring. Then, after drying at 80 ° C. for 6 hours, classification was performed to obtain a sample carrying 5 wt% aluminum sulfate having a particle diameter of 355 to 500 μm. The obtained sample was subjected to BET specific surface area, total pore volume measurement, moisture adsorption amount ratio measurement, and siloxane adsorption / desorption measurement.

<Comparative Example 9>
25 mg of ruthenium chloride n-hydrate (manufactured by Wako Pure Chemical Industries, solubility 5 g or more) is dissolved in 650 mg of ion-exchanged water, and the aqueous solution and coal-based activated carbon (BET specific surface area: 1460 m ² / g, total pore volume: 0. 92 cc / g, particle size: 355 to 500 μm) and 475 mg were mixed with stirring. Thereafter, the sample was dried at 80 ° C. for 6 hours and then classified to obtain a sample supporting 5% by weight of ruthenium chloride having a particle diameter of 355 to 500 μm. The obtained sample was subjected to BET specific surface area, total pore volume measurement, moisture adsorption amount ratio measurement, and siloxane adsorption / desorption measurement.

<Comparative Example 10>
25 mg of iron (III) sulfate n-hydrate (manufactured by Wako Pure Chemical Industries, solubility 246 g at 0 ° C.) is dissolved in 650 mg of ion-exchanged water, the aqueous solution and coal-based activated carbon (BET specific surface area: 1460 m ² / g, total 475 mg) (pore volume: 0.92 cc / g, particle size: 355 to 500 μm). Thereafter, drying was performed at 80 ° C. for 6 hours, followed by classification to obtain a 5% by weight iron (III) sulfate-supporting sample having a particle diameter of 355 to 500 μm. The obtained sample was subjected to BET specific surface area, total pore volume measurement, moisture adsorption amount ratio measurement, and siloxane adsorption / desorption measurement.

Tables 4 and 5 show the results of BET specific surface area, total pore volume measurement, moisture adsorption amount measurement, and siloxane adsorption / desorption measurement for Examples 15 to 23 and Comparative Examples 1 to 2 and 7 to 10. Show. As is apparent from Tables 4 and 5, Examples 15 to 23 according to the present invention are low in comparison with the cases where the water adsorption amount ratio is less than 0.10 (Comparative Examples 1 to 2 and 7 to 10). It turns out that it is excellent in detachability.

<Example 24>
A nitric acid aqueous solution was prepared by mixing 5 g of nitric acid (1.38) (manufactured by Nacalai Tesque) and 12 g of ion-exchanged water. 3 g of coal-based activated carbon (BET specific surface area: 1460 m ² / g, total pore volume: 0.92 cc / g, particle size: 355 to 500 μm) was added to the prepared nitric acid aqueous solution and heated to about 100 ° C. Reflux treatment for hours was performed. After cooling to room temperature, it was filtered, washed 10 times with 100 ml of ion exchange water, and dried at 80 ° C. overnight. Furthermore, hydrophilicized activated carbon was obtained by treatment at 350 ° C. for 4 hours in an air atmosphere.
2 mg of iron (III) sulfate n-hydrate (manufactured by Wako Pure Chemical Industries, solubility of 246 g at 0 ° C.) was dissolved in 1380 mg of ion-exchanged water, and the aqueous solution and 998 mg of hydrophilized activated carbon were mixed with stirring. Thereafter, drying was performed at 80 ° C. for 6 hours, followed by classification to obtain a 0.2 wt% iron (III) sulfate supporting sample having a particle diameter of 355 to 500 μm. The obtained sample was subjected to BET specific surface area, total pore volume measurement, moisture adsorption amount ratio measurement, and siloxane adsorption / desorption measurement.

<Example 25>
A nitric acid aqueous solution was prepared by mixing 5 g of nitric acid (1.38) (manufactured by Nacalai Tesque) and 12 g of ion-exchanged water. 3 g of coal-based activated carbon (BET specific surface area: 1460 m ² / g, total pore volume: 0.92 cc / g, particle size: 355 to 500 μm) was added to the prepared nitric acid aqueous solution and heated to about 100 ° C. Reflux treatment for hours was performed. After cooling to room temperature, it was filtered, washed 10 times with 100 ml of ion exchange water, and dried at 80 ° C. overnight. Furthermore, hydrophilicized activated carbon was obtained by treatment at 350 ° C. for 4 hours in an air atmosphere.
20 mg of iron (III) sulfate n hydrate (manufactured by Wako Pure Chemical Industries, solubility of 246 g at 0 ° C.) was dissolved in 1350 mg of ion-exchanged water, and the aqueous solution and 980 mg of hydrophilicized activated carbon were mixed with stirring. Thereafter, after drying at 80 ° C. for 6 hours, classification was carried out to obtain a sample supporting 2% by weight of iron (III) sulfate having a particle diameter of 355 to 500 μm. The obtained sample was subjected to BET specific surface area, total pore volume measurement, moisture adsorption amount ratio measurement, and siloxane adsorption / desorption measurement.

<Example 26>
A nitric acid aqueous solution was prepared by mixing 5 g of nitric acid (1.38) (manufactured by Nacalai Tesque) and 12 g of ion-exchanged water. 3 g of coal-based activated carbon (BET specific surface area: 1460 m ² / g, total pore volume: 0.92 cc / g, particle size: 355 to 500 μm) was added to the prepared nitric acid aqueous solution and heated to about 100 ° C. Reflux treatment for hours was performed. After cooling to room temperature, it was filtered, washed 10 times with 100 ml of ion exchange water, and dried at 80 ° C. overnight. Furthermore, hydrophilicized activated carbon was obtained by treatment at 350 ° C. for 4 hours in an air atmosphere.
100 mg of iron (III) sulfate n hydrate (manufactured by Wako Pure Chemical Industries, solubility of 246 g at 0 ° C.) was dissolved in 1240 mg of ion-exchanged water, and the aqueous solution and 900 mg of hydrophilized activated carbon were mixed with stirring. Thereafter, drying was performed at 80 ° C. for 6 hours, followed by classification to obtain a 10% by weight iron (III) sulfate supporting sample having a particle diameter of 355 to 500 μm. The obtained sample was subjected to BET specific surface area, total pore volume measurement, moisture adsorption amount ratio measurement, and siloxane adsorption / desorption measurement.

<Example 27>
A nitric acid aqueous solution was prepared by mixing 5 g of nitric acid (1.38) (manufactured by Nacalai Tesque) and 12 g of ion-exchanged water. 3 g of coal-based activated carbon (BET specific surface area: 1460 m ² / g, total pore volume: 0.92 cc / g, particle size: 355 to 500 μm) was added to the prepared nitric acid aqueous solution and heated to about 100 ° C. Reflux treatment for hours was performed. After cooling to room temperature, it was filtered, washed 10 times with 100 ml of ion exchange water, and dried at 80 ° C. overnight. Furthermore, hydrophilicized activated carbon was obtained by treatment at 350 ° C. for 4 hours in an air atmosphere.
150 mg of iron (III) sulfate n hydrate (manufactured by Wako Pure Chemical Industries, solubility 246 g at 0 ° C.) was dissolved in 1170 mg of ion-exchanged water, and the aqueous solution and 850 mg of hydrophilic activated carbon were mixed with stirring. Thereafter, the sample was dried at 80 ° C. for 6 hours and classified to obtain a sample carrying 15% by weight of iron (III) sulfate having a particle diameter of 355 to 500 μm. The obtained sample was subjected to BET specific surface area, total pore volume measurement, moisture adsorption amount ratio measurement, and siloxane adsorption / desorption measurement.

<Example 28>
A nitric acid aqueous solution was prepared by mixing 5 g of nitric acid (1.38) (manufactured by Nacalai Tesque) and 12 g of ion-exchanged water. 3 g of coal-based activated carbon (BET specific surface area: 1460 m ² / g, total pore volume: 0.92 cc / g, particle size: 355 to 500 μm) was added to the prepared nitric acid aqueous solution and heated to about 100 ° C. Reflux treatment for hours was performed. After cooling to room temperature, it was filtered, washed 10 times with 100 ml of ion exchange water, and dried at 80 ° C. overnight. Furthermore, hydrophilicized activated carbon was obtained by treatment at 350 ° C. for 4 hours in an air atmosphere.
200 mg of iron (III) sulfate n-hydrate (manufactured by Wako Pure Chemical Industries, solubility 246 g at 0 ° C.) was dissolved in 1100 mg of ion-exchanged water, and the aqueous solution and 800 mg of hydrophilic activated carbon were mixed with stirring. Thereafter, drying was performed at 80 ° C. for 6 hours, followed by classification to obtain a 20% by weight iron (III) sulfate-supporting sample having a particle diameter of 355 to 500 μm. The obtained sample was subjected to BET specific surface area, total pore volume measurement, moisture adsorption amount ratio measurement, and siloxane adsorption / desorption measurement.

<Comparative Example 11>
A nitric acid aqueous solution was prepared by mixing 5 g of nitric acid (1.38) (manufactured by Nacalai Tesque) and 12 g of ion-exchanged water. 3 g of coal-based activated carbon (BET specific surface area: 1460 m ² / g, total pore volume: 0.92 cc / g, particle size: 355 to 500 μm) was added to the prepared nitric acid aqueous solution and heated to about 100 ° C. Reflux treatment for hours was performed. After cooling to room temperature, it was filtered, washed 10 times with 100 ml of ion exchange water, and dried at 80 ° C. overnight. Furthermore, hydrophilicized activated carbon was obtained by treatment at 350 ° C. for 4 hours in an air atmosphere.
300 mg of iron (III) sulfate n hydrate (manufactured by Wako Pure Chemical Industries, solubility of 246 g at 0 ° C.) was dissolved in 970 mg of ion-exchanged water, and the aqueous solution and 700 mg of hydrophilized activated carbon were mixed with stirring. Thereafter, the sample was dried at 80 ° C. for 6 hours and classified to obtain a 30% by weight iron (III) sulfate loaded sample having a particle diameter of 355 to 500 μm. The obtained sample was subjected to BET specific surface area, total pore volume measurement, moisture adsorption amount ratio measurement, and siloxane adsorption / desorption measurement.

Table 6 shows the results of BET specific surface area, total pore volume measurement, moisture adsorption amount measurement, and siloxane adsorption / desorption measurement for Examples 16, 24 to 28, and Comparative Examples 5 and 11. As is apparent from Table 6, in Example 16 and Examples 24-28 of the present invention, when the metal salt was not supported (Comparative Example 5), the amount of the metal salt supported was 20% by weight. It can be seen that it is excellent in low detachability as compared with the case of larger than (Comparative Example 11).

According to the present invention, the siloxane gas can be efficiently removed, and since the siloxane gas once removed has few problems of desorption due to environmental changes, it can be expected to greatly contribute to the industry.

Claims

In a siloxane remover in which an active compound or metal salt is supported on activated carbon in an amount of 0.1 to 20% by weight, the water adsorption amount at a temperature of 25 ° C. and a relative humidity of 40% is 25 ° C. and a relative humidity is 90%. A siloxane removing agent, wherein a water adsorption amount ratio divided by an amount of water adsorption at the time is 0.10 or more.
The siloxane remover according to claim 1, wherein the acidic compound is a compound having an acid dissociation index (pKa) of 2.2 or less.
The metal salt is a metal salt containing a trivalent metal element having a third ionization energy of 30 to 35 eV or a tetravalent or higher metal element having a fourth ionization energy of 30 to 55 eV. Siloxane remover.
A siloxane removal filter comprising the siloxane remover according to any one of claims 1 to 3.