JP2023081478A - Gas adsorbent and fiber sheet comprising the same - Google Patents

Abstract

To provide a gas adsorbent having a great ability to remove low-molecular-weight aldehydse and high-molecular-weight aldehydes.SOLUTION: A gas adsorbent comprises a porous body having polyphenols supported thereon and a porous body having an aldehyde reaction agent supported thereon.SELECTED DRAWING: None

Description

TECHNICAL FIELD The present invention relates to a gas adsorbent having high removal performance for low-molecular-weight aldehydes and high-molecular-weight aldehydes.

In recent years, due to the growing desire to improve the living environment, there is a demand for a filter medium that is a deodorizing fiber sheet that can remove volatile organic compounds (VOCs) in addition to dust present in the air to purify the air. . In particular, in vehicles such as automobiles, there are many parts using binders and paints in a narrow space, so VOCs are present at a high concentration. In addition, high-molecular-weight aldehydes such as nonenal and nonadienal, which are thought to be caused by body odor, also pose a problem of unpleasant odors. Therefore, efficient removal of VOCs by air filter media is required.

In recent years, efforts have been made to reduce the amount of organic solvents generated, and the amount of organic solvents generated such as toluene and xylene has come to be kept below the guidelines set by the Ministry of Health, Labor and Welfare.

However, it is difficult to deal with low-molecular-weight aldehydes such as formaldehyde and acetaldehyde, which are VOCs derived from automobile parts, and high-molecular-weight aldehydes such as nonenal and nonadienal caused by body odor. There is a demand for the development of air filter media that can

In recent years, with regard to low-molecular-weight aldehydes such as formaldehyde and acetaldehyde, deodorant sheet filter media carrying acid hydrazides and compounds with amino groups have been used, and these have excellent adsorption performance for low-boiling-point aldehydes (for example, patent Reference 1).

JP 2009-28207 A

However, the amine compound supported by the low-molecular-weight aldehyde adsorbent may decompose to some extent over time, and it has been desired to reduce deterioration over time of the low-molecular-weight aldehyde removal performance by suppressing this decomposition. . In addition, high-molecular-weight aldehydes such as nonenal and nonadienal have the problem of being difficult to remove by chemical adsorption with an adsorbent carrying an amine-based chemical. SUMMARY OF THE INVENTION In view of the above problems, an object of the present invention is to provide a gas adsorbent that has high performance in removing low-molecular-weight aldehydes and high-molecular-weight aldehydes and has excellent durability.

The inventors of the present invention have made intensive studies to achieve the above object, and found that a gas adsorbent containing a polyphenol-supported porous body and an aldehyde-reactive agent-supported porous body has low molecular weight aldehyde and It was found to have high removal performance for high-molecular-weight aldehydes.

The present invention has been completed based on these findings, and the following inventions are provided according to the present invention.

That is, the present invention is a gas adsorbent containing a porous body supporting a polyphenol and a porous body supporting an aldehyde-reactive agent.

According to a preferred embodiment of the gas adsorbent of the present invention, the porous body supporting polyphenol is activated carbon.

According to a preferred embodiment of the gas adsorbent of the present invention, the porous material supporting the aldehyde-reactive agent is an inorganic porous material.

According to a preferred embodiment of the gas adsorbent of the present invention, the aldehyde reactive agent is an amine compound.

According to a preferred embodiment of the gas adsorbent of the present invention, the inorganic porous material has an average pore diameter of 0.5 to 100 nm.

According to a preferred embodiment of the gas adsorbent of the present invention, the polyphenol is at least one selected from catechin, anthocyanin, tannic acid, rutin, isobravone, poroanthocyanidin, and modifications thereof.

According to a preferred embodiment of the gas adsorbent of the present invention, the specific surface area of activated carbon measured by the nitrogen gas adsorption BET method is 200 to 1600 m ² /g.

According to a preferred embodiment of the gas adsorbent of the present invention, the content mass ratio of the polyphenol-supported activated carbon to the aldehyde-reactive agent-supported inorganic porous material (the aldehyde-reactive agent-supported inorganic porous material content mass/content mass of activated carbon on which polyphenol is supported) is 0.05 to 1.00.

Moreover, the fiber sheet of the present invention contains the gas adsorbent of the present invention.

According to a preferred embodiment of the fiber sheet of the present invention, the content of the gas adsorbent per unit area is 15-400 g/m ² .

According to the present invention, it is possible to provide a gas adsorbent that is excellent in removing low-molecular-weight aldehydes and high-molecular-weight aldehydes and effective in suppressing the decomposition of aldehyde-reactive agents.

The gas adsorbent of the present invention is a gas adsorbent containing a polyphenol-supported porous body and an aldehyde-reactive agent-supported porous body. Details of this will be described below.

The gas adsorbent of the present invention contains a polyphenol-supported porous body. Although the polyphenol used in the present invention is not particularly limited, catechin, anthocyanin, tannic acid, rutin, isobravone, poroanthocyanidin and modified products thereof are preferred, and tannic acid is particularly preferred.

The amount of polyphenol supported is preferably 2 to 40% by mass, more preferably 5 to 25% by mass, based on the entire porous body on which polyphenol is supported. By being in the above range, the contact efficiency of polyphenol with respect to high-molecular-weight aldehyde components in the air is excellent, which is preferable.

The polyphenol-supported porous body of the present invention is not particularly limited, and may be porous silicon dioxide (silica), zeolite, sepiolite, activated alumina, aluminum silicate, silica gel, alumina gel, activated clay, phosphorus. Depending on the purpose, it can be selected from among layered compounds such as zirconium oxide and ammonium polytriphosphate, porous clay minerals, and activated carbon, with activated carbon being preferred. Activated carbon can be arbitrarily selected from known materials such as coconut shells, coal pitch, and phenolic resin as a raw material, and can be obtained by adjusting the activation conditions to form pores by high-temperature treatment with steam or chemical treatment such as hydrochloric acid. Among them, it is more preferable to use coconut shells as a raw material and select the activation method with steam, because it is easy to obtain activated carbon with a smaller pore size.

The specific surface area of the activated carbon used in the present invention is preferably in the range of 200-1600 m ² /g, more preferably in the range of 900-1300 m ² /g. When the specific surface area of the activated carbon is within the above range, the physical adsorption performance of the pores of the activated carbon and the chemical adsorption performance of the polyphenol supported on the activated carbon can be more compatible, which is preferable. In addition, the specific surface area here is the BET multipoint method specified in JIS R 1626-1996 (constant volume method described in 6.1 Volume method, preheating treatment, N ₂ as adsorbate, constant volume method can be measured according to

In the activated carbon of the present invention, the ratio of the pore volume of pores with a pore diameter of 0.4 to 2 nm calculated by the MP method is 0.4 nm or more as calculated by the MP method and the BJH method. 75 to 100%, more preferably 80 to 100%, that is, the total pore volume of pores with a pore diameter of more than 2 nm, with a pore diameter of 0.4 nm or more When the ratio to the volume is less than 25%, more preferably less than 20%, the adsorbent having this activated carbon has excellent physical adsorption performance for organic gas components such as toluene, and further adsorbs gas components once adsorbed. Re-release from the agent is more suppressed.

The MP (MICROPORE) method is an analytical method capable of quantifying the distribution of pore diameters of pores in activated carbon. In general, methods for analyzing the pore diameter and pore volume of activated carbon include the MP (MICROPORE) method and the BJH (Barrett-Joyner-Halenda) method. In the present invention, the MP method was adopted for the analysis of micropores with a pore diameter of 0.4 to 2 nm, in which capillary condensation does not occur, among the pores of activated carbon. In addition, in the present invention, the BJH method was adopted for the analysis of macropores having a pore diameter of 2 nm or more among the pores of activated carbon. Here, the pore volume of pores having a pore diameter of 0.4 nm or more calculated by the MP method and the BJH method of activated carbon in the present invention means the value of the pore volume obtained by the MP method and the pore volume obtained by the BJH method. It refers to the total value of the pore volume values obtained.

The gas adsorbent of the present invention contains a porous body carrying an aldehyde-reactive agent. Amine compounds are preferred as the aldehyde reaction agent used in the present invention. More preferred are hydrazide compounds such as adipic acid dihydrazide, dodecanedioic acid dihydrazide and succinic acid dihydrazide, p-aminobenzenesulfonic acid, ethylene urea condensates and tris(hydroxymethyl)aminomethane. Among them, adipic acid dihydrazide is preferable in terms of adsorption performance of aldehydes.

The content of adipic acid dihydrazide in the present invention is preferably 7-200 mg, more preferably 35-150 mg, per 1 g of the porous material. By setting the content of adipic acid dihydrazide within the above range, it is possible to obtain a gas adsorbent that has an increased adsorption capacity for low-molecular-weight aldehydes and that does not hinder the adsorption rate for other gases.

The porous material used in the porous material supporting the aldehyde-reactive agent of the present invention is preferably an inorganic porous material. As the inorganic porous material, an inorganic porous material that reacts little with the supported aldehyde-reactive agent is preferable. Examples of the inorganic porous material used in the present invention include layered compounds such as porous silicon dioxide (silica), zeolite, sepiolite, activated alumina, aluminum silicate, silica gel, alumina gel, activated clay, zirconium phosphate and ammonium polytriphosphate, It can be selected from porous clay minerals according to the purpose, but inorganic porous materials that react less with aldehyde-reactive agents are preferable. A material having an appropriate pore volume can be procured at a low cost, which is preferable.

The specific surface area of the porous body used for the porous body supporting the aldehyde-reactive agent of the present invention is preferably 50 to 1200 m ² /g, more preferably 100 to 1000 m ² /g. By setting the specific surface area of the porous body to 50 to 1200 m ² /g, it is possible to obtain a contact area effective for contact between the supported aldehyde-reactive agent and the low-molecular-weight aldehyde gas, which has mechanical strength, and a reaction rate. It is preferable because it improves. The specific surface area is measured according to the BET multi-point method specified in JIS R 1626-1996 (constant volume method described in 6.1 Volume method, preheating, N ₂ as adsorbate, and measurement by the constant volume method). can.

The porous body preferably has a pore volume of 0.4 to 2.5 cc/g, more preferably 0.8 to 2.0 cc/g. By setting the pore volume of the porous body to 0.4 to 2.5 cc/g, the amount of the aldehyde-reactive agent supported is increased while retaining pores that are excellent in reacting with low-molecular-weight aldehyde gas in the air. It is preferable because it can increase the adsorption efficiency and adsorption capacity as an aldehyde adsorbent. The pore volume referred to here can be measured by the BJH method described above.

When an inorganic porous material is used as the porous material, it preferably has an average pore diameter of 0.5 to 100 nm, more preferably 2 to 50 nm. By setting the average pore diameter of the inorganic porous material to 0.5 to 100 nm, it is possible to secure a large specific surface area for supporting the aldehyde-reactive agent while ensuring the mechanical strength of the porous material. In addition, the aldehyde-reactive agent easily permeates into the pores, which is preferable.

In addition, pores with a diameter of 2 to 50 nm are called mesopores, and a porous material having mesopores is excellent in efficiently advancing the reaction between the supported aldehyde-reactive agent and acetaldehyde. The average pore diameter here can be calculated as the average pore diameter (D) from the above specific surface area (S) and the above pore volume (V) from the following equation. Note that the shape of the pores is assumed to be cylindrical.
D=4V/S
Amine compounds used in aldehyde-reactive agents are believed to be susceptible to decomposition. Therefore, in the present invention, the inclusion of a porous material supporting polyphenols having an antioxidant effect suppresses the decomposition of amine compounds, thereby suppressing the deterioration of the aldehyde removal performance over time and the odor thereof.

Also, the average particle size of each porous body is preferably 40 to 500 μm. In the present invention, a plurality of porous bodies are mixed and used, but the closer the average particle diameter of the porous bodies, the easier it is to disperse them uniformly, and the less likely they are to separate during subsequent handling. As for the relative relationship of the average particle diameters of the porous bodies to be mixed and used, the porous body having the smallest average particle diameter is preferably within 5 times, more preferably within 3 times.

In the gas adsorbent of the present invention, when activated carbon is used as the porous material supporting polyphenol, and inorganic porous material is used as the porous material supporting the aldehyde reaction agent, polyphenol The content mass ratio of the activated carbon supporting the is to the inorganic porous material supporting the aldehyde-reactive agent (the content mass of the inorganic porous material supporting the aldehyde-reacting agent/the content mass of the activated carbon supporting the polyphenol) is It is preferably 0.05 to 1.00, more preferably 0.10 to 0.50. By setting the content mass ratio of the activated carbon and the inorganic porous material to 0.05 to 1.00, the polyphenol-supported porous material and the aldehyde-reactive agent-supported porous material are efficiently brought into contact with each other, and the aldehyde is reacted. It is possible to enhance the effect of suppressing deterioration of the reactive chemical.

The gas adsorbent of the present invention is preferably particulate, and the shape can be arbitrarily selected from known shapes such as spherical, crushed, and molded shapes.

The fiber sheet of the present invention contains the gas adsorbent of the present invention. The fiber sheet of the present invention is a sheet formed by dispersing the gas adsorbent between the fibers of a fabric such as a woven fabric, a knitted fabric, or a nonwoven fabric, or a sheet formed by connecting the surface of the gas adsorbent with an adhesive or the like. things are mentioned.

The content (basis weight) of the gas adsorbent per unit area in the fiber sheet of the present invention is preferably in the range of 15 to 400 g/m ² . Further, the range of 30 to 300 g/m ² is more preferable because the gas adsorption capacity is high and the obtained fiber sheet is excellent in pleating (folding) workability when processed into an air filter.

The gas adsorbent of the present invention is suitably used for filter media, particularly filter media for air filters. This filter medium has the gas adsorbent of the present invention held in at least one between one or more layers formed by two or more layers of fabric.

The amount of the gas adsorbent used in the filter medium using the gas adsorbent of the present invention is preferably in the range of 15 to 400 g/m ² , more preferably 15 to 400 g/m 2 from the viewpoint of obtaining gas removal efficiency and adsorption capacity when used as a filter medium. is between 30 and 300 g/m ² .

As a specific manufacturing method of the filter medium, for example, a gas adsorbent and powdered thermal adhesive resin particles are uniformly dispersed on one fabric, and after heating and melting the thermal adhesive resin particles with a heater, the other fabric is applied. Examples include a method of integrating by stacking and pressure bonding, and a method of integrating by stacking and pressing the other fabric after spraying gas adsorbent particles onto one of the fabrics while spraying a heat-melted resin. However, it is not limited to these.

The form of the fabric is not particularly limited, and can be arbitrarily selected from woven fabric, knitted fabric, molded net, non-woven fabric, and the like. Among them, nonwoven fabrics are preferable because the desired physical properties can be easily obtained by arbitrarily selecting the fiber diameter, fiber length, etc. of the fibers to be used and combining them. Examples of nonwoven fabrics include chemical bond nonwoven fabrics, wet stamp nonwoven fabrics, spunbond nonwoven fabrics, meltblown nonwoven fabrics, spunlace nonwoven fabrics and air-laid nonwoven fabrics.

The nonwoven fabric included in the filter medium is preferably an electret nonwoven fabric. The electret nonwoven fabric is preferable because the filter medium can collect dust in the air with higher efficiency.

The thickness of the fabric is preferably 0.08 to 1.00 mm from the viewpoint of having a certain strength and increasing the area that can be accommodated in a certain volume when pleated, and the lower limit is 0.15 mm or more. More preferably, the upper limit is 0.60 mm or less. Although the filter medium has two or more layers of fabric, the thickness of these fabrics may be the same or different.

The air filter is constructed by fixing the four sides of the filter medium and the outer frame. Here, the fiber sheet and the filter medium may be used as they are in a sheet form, or may be pleated to form a three-dimensional shape having ridges and valleys.

EXAMPLES Hereinafter, the effects of the present invention will be shown more specifically by way of examples, but the present invention is not limited only to the following examples. The measurement method is as follows.

(1) BET specific surface area NOVA2200e manufactured by Yuasa Ionics Co., Ltd. is used for the specific surface area of activated carbon, and the specific surface area is measured by the BET multipoint method specified in JIS R 1626-1996 (constant volume method described in 6.1 volume method, before heating treated, _N2 as adsorbate, measurement by constant volume method.).

About 100 mg of the sample was collected, vacuum degassed at 100° C. for 4 hours, N ₂ was used as an adsorbate, and the measurement was carried out by the constant volume method. The specific surface area was measured to one decimal place and rounded off to one decimal place.

(2) Amount of polyphenols supported in activated carbon supporting polyphenol The amount was calculated and converted into the amount supported on activated carbon.

(3) Amount of Aldehyde-Reactive Agent Supported in Porous Body Supporting Aldehyde-Reactive Agent The mass of the gas adsorbent after impregnating the dispersion of the aldehyde-reactive agent into the inorganic porous material and drying, and the impregnation/drying The total supported amount was calculated from the difference from the mass of the previous porous body, and converted into the supported amount with respect to the porous body.

(4) Degradation test 10 g of the gas adsorbent obtained in each example was placed in a polyethylene cup and subjected to heat and moisture absorption treatment at 85°C and 85% for 3 days in a constant temperature and humidity machine (Espec Co., Ltd. PL-2J). , to obtain the gas adsorbent (after aging).

(5) Sieving method Put 5 g of the sample in a PE cup (50 mesh sieve machine manufactured by Kenis Co., Ltd.), and put it in a small particle size (average particle size 300 μm) tannic acid impregnated activated carbon and a large particle size (average particle size 400 μm). of adipic acid dihydrazide impregnated silica.

(6) Color identification Regarding the color of dihydrazide-adipate-impregnated silica obtained by sieving tannic acid-impregnated activated carbon and dihydrazide-adipate-impregnated silica by the method described in [Screening method], 1 point: white (no change), 2 points: either A panel of 5 well-trained healthy men and women scored according to 4 standards of white, 3 points: rather yellow, and 4 points: yellow, and the average value was calculated.

(7) Adsorbent odor intensity (point)
Tannic acid-impregnated activated carbon and dihydrazide adipic acid-impregnated silica were sieved by the method described in [Screening method]. 2 points: Weak odor that can be identified, 1 point: Barely perceivable odor. Scored by five well-trained panelists of healthy men and women, and the average value was calculated.

(8) Adsorbent pleasure/discomfort (point)
Tannic acid-impregnated activated carbon and dihydrazide adipic acid-impregnated silica were sieved by the method described in [Screening method]. -2 points: unpleasant, -1 points: somewhat unpleasant, 0 points: neither pleasant nor unpleasant , 1 point: moderately comfortable, and 2 points: comfortable. Five well-trained healthy male and female panelists scored and calculated the average value.

(9) Acetaldehyde saturated adsorption amount (g/m ² ), initial acetaldehyde removal efficiency (%)
A circular filter medium sample with a diameter of 6 cm (area: 28.3 cm ² ) was collected from the sheet-shaped filter medium using the gas adsorbent obtained in each example, and placed in a dryer heated to 80°C. It was taken out after time drying treatment. Next, two cylindrical wind tunnels having a ventilation diameter of 4 cm and a body length of 15 cm were prepared, and attached to one side and the other side of the filter medium sample, respectively.

Next, air containing acetaldehyde gas with a concentration of 10 ppm adjusted to a temperature of 20 ° C. and a relative humidity of 50% is passed from one side to the other side of the filter medium sample at a wind speed of 0.2 m / sec. let me 120 seconds after the acetaldehyde gas passed through the filter medium sample, the acetaldehyde concentration (ppm) in the air on the downstream side of the filter medium sample (the other side of the filter medium sample) was measured using an infrared absorption gas concentration meter (Nippon Thermo Co., Ltd. (manufactured by MIRAN SapphlRe) for 60 minutes at 10-second intervals until the acetaldehyde gas concentration on the downstream side of the sample reaches 9 ppm, that is, the acetaldehyde adsorption efficiency of the filter material reaches 10%. The cumulative adsorption amount (g/m ² ) of acetaldehyde per (1 m ² ) was calculated and taken as the saturated adsorption amount. Moreover, the removal efficiency was calculated by the following formula.
Removal efficiency (%) = [(C0-C)/C0] x 100
C0: Acetaldehyde concentration on the upstream side (= 10 ppm)
C: Acetaldehyde concentration on the downstream side (ppm)
The removal efficiency 120 seconds after the start of addition of acetaldehyde was defined as the initial removal efficiency.

(10) Initial removal performance of trans-2-nonenal by sensory evaluation (initial nonenal odor intensity, initial nonenal comfort and discomfort)
Trans-2-nonenal (manufactured by Fuji Film, Wako Pure Chemical Industries, Ltd.) was selected as the high-molecular-weight aldehyde. Gas was generated by sealing 10 ml of trans-2-nonenal solution. In addition, in the same manner as in (9) above, a circular filter medium sample with a diameter of 6 cm (area: 28.3 cm ² ) was collected from the sheet-like filter medium using the gas adsorbent obtained in each example, and heated at 80°C. It was placed in a dryer heated to 100°C and taken out after drying for 2 hours. Next, two cylindrical wind tunnels having a ventilation diameter of 4 cm and a body length of 15 cm were prepared, and attached to one side and the other side of the filter medium sample, respectively.

Next, air containing trans-2-nonenal gas adjusted to a temperature of 20 ° C. and a relative humidity of 50% was blown from one side of the filter medium sample to the other side at a wind speed of 0.2 m / sec. let it pass. The initial trans-2-nonenal gas removal property was measured by collecting air on the downstream side of the filter medium sample (the other side of the filter medium sample) in a sachet 120 seconds after passing trans-2-nonenal gas through the filter medium sample. Later, as an odor intensity measurement, 5 points: strong odor, 4 points: strong odor, 3 points: easily perceivable odor, 2 points: weak odor, 1 point: barely perceptible odor. In addition, as a measure of pleasure and discomfort, -2 points: unpleasant, -1 point: somewhat unpleasant, 0 points: neither pleasant nor unpleasant, 1 point: somewhat pleasant, 2 points: pleasant, well-trained healthy men and women Five panelists scored and the average value was calculated.

[Method for producing filter medium using gas adsorbent]
Gas adsorbent and polyethylene-based adhesive powder (hereinafter referred to as adhesive powder) are blended at a mass ratio of 2 gas adsorbent: 1 adhesive powder, and the aggregate nonwoven fabric made of spunbond (Toray Industries, Inc. Acstar (registered (trademark) H2070-1S, thickness 0.27 mm), and the adhesive powder was melted by heating to 120° C. in a heating furnace.

Next, an electret meltblown nonwoven fabric (18 g/m ² in basis weight, 0.25 mm in thickness) was layered on the sprinkling surface, and then pressed with nip rolls to obtain a sheet-like filter medium with a predetermined thickness.

Regarding the amount of the gas adsorbent and the adhesive powder supported, the total basis weight of the aggregate nonwoven fabric and the electret meltblown nonwoven fabric and the basis weight of the sheet-like filter material having the predetermined thickness were measured, and the difference was calculated. , and the difference was multiplied by the charged amount ratio of each component, and converted into the supported amount with respect to the entire filter medium.

[Example 1]
Granular activated carbon (“Kuraray Coal” (registered trademark) GG 30-60 mesh manufactured by Kuraray Co., Ltd., average particle size 300 μm according to JIS Z8815 method, specific surface area measured by BET multipoint method) was used as the polyphenol-supported porous material. 1000 m ² /g), supporting activated carbon supported so that tannic acid is 10% by mass of the whole, and porous silica particles (pores measured by BJH method) as a porous body supporting an aldehyde reaction agent Volume 1.0 cc/g, specific surface area 500 m ² /g measured by BET multipoint method, average particle size 400 μm by JISZ8815 method, average pore size 6 nm), adipic acid dihydrazide (manufactured by Nippon Kasei Co., Ltd.) was added to the entire surface. A supported silica that had been subjected to a supporting treatment so as to have a content of 7% by mass was used.

These were mixed at a mass ratio of porous material supporting polyphenol:porous material supporting aldehyde reaction agent=95:5 to obtain a gas adsorbent. Using the obtained gas adsorbent, the above evaluations (5) to (8) were performed.

The amount of this gas adsorbent is adjusted by the method described in [Production method of filter material using gas adsorbent] above so that the coating amount of the gas adsorbent is 150 g/m ² , and the gas adsorbent is A filter medium was manufactured using Since the gas adsorbent is 150 g/m ² , the porous body supporting tannic acid is 142.5 g/m ² , and the porous body supporting the aldehyde reaction agent is 7.5 g/m ² . The mass ratio of the supported porous body:the porous body supporting the aldehyde-reactive agent was 95:5. The thickness of this filter medium was 0.9 mm. The above evaluations (9) and (10) were performed using the filter medium using the obtained gas adsorbent.

[Example 2]
A gas adsorbent was obtained in the same manner as in Example 1, except that the mass ratio of the porous body supporting polyphenol:the porous body supporting the aldehyde reaction agent was 90:10. Using the obtained gas adsorbent, the above evaluations (5) to (8) were performed.

The amount of this gas adsorbent is adjusted by the method described in [Production method of filter material using gas adsorbent] above so that the coating amount of the gas adsorbent is 150 g/m ² , and the gas adsorbent is A filter medium was manufactured using Since the gas adsorbent is for 150 g/m ² , the polyphenol-supported porous body is 135 g/m ² , and the aldehyde reaction agent-supported porous body is 15 g/m ² , so the polyphenol-supported porous body is 15 g/m 2 . The mass ratio of body:porous body supporting the aldehyde-reactive agent was 90:10. The thickness of this filter medium was 0.9 mm.

The above evaluations (9) and (10) were performed using the filter medium using the obtained gas adsorbent.

[Example 3]
A gas adsorbent was obtained in the same manner as in Example 1, except that the mass ratio of porous body supporting polyphenol:porous body supporting aldehyde reaction agent was 50:50. Using the obtained gas adsorbent, the above evaluations (5) to (8) were performed.

The amount of this gas adsorbent is adjusted by the method described in [Production method of filter material using gas adsorbent] above so that the coating amount of the gas adsorbent is 150 g/m ² , and the gas adsorbent is A filter medium was manufactured using Since the gas adsorbent is for 150 g/m ² , the polyphenol-supported porous body is 75 g/m ² , and the aldehyde reaction agent-supported porous body is 75 g/m ² , so the polyphenol-supported porous body is 75 g/m 2 . The mass ratio of the body:the porous body supporting the aldehyde-reactive agent was 50:50. The thickness of this filter medium was 0.9 mm. The above evaluations (9) and (10) were performed using the filter medium using the obtained gas adsorbent.

[Example 4]
A gas adsorbent was obtained in the same manner as in Example 1, except that the mass ratio of porous body supporting polyphenol:porous body supporting aldehyde reaction agent was 40:60. Using the obtained gas adsorbent, the above evaluations (5) to (8) were performed.

The amount of this gas adsorbent is adjusted by the method described in [Production method of filter material using gas adsorbent] above so that the coating amount of the gas adsorbent is 150 g/m ² , and the gas adsorbent is A filter medium was manufactured using Since the gas adsorbent is for 150 g/m ² , the polyphenol-supported porous body is 60 g/m ² , and the aldehyde reaction agent-supported porous body is 90 g/m ² , so the polyphenol-supported porous body is 90 g/m 2 . The mass ratio of the body:the porous body supporting the aldehyde-reactive agent was 40:60. The thickness of this filter medium was 0.9 mm. The above evaluations (9) and (10) were performed using a filter medium using the obtained gas adsorbent (after deterioration).

[Example 5]
A gas adsorbent was obtained in the same manner as in Example 1. Using 10 g of the obtained gas adsorbent, the deterioration test described in (4) above was performed to obtain a gas adsorbent (after deterioration). Using this, the above evaluations (5) to (8) were performed.

This gas adsorbent (degraded) was applied by the method described in the above [Method for producing filter material using gas adsorbent], and the amount of spraying was such that the coating amount of the gas adsorbent (degraded) was 150 g/m ² . was adjusted to produce a filter medium using the gas adsorbent (degraded). Since the gas adsorbent (after deterioration) is for 150 g/m ² , the polyphenol-supported porous body is 142.5 g/m ² and the aldehyde-reactive agent-supported porous body is 7.5 g/m ² . , polyphenol-supported porous body: aldehyde-reactive agent-supported porous body=95:5 mass ratio. The thickness of this filter medium was 0.9 mm.

The above evaluations (9) and (10) were performed using a filter medium using the obtained gas adsorbent (after deterioration).

[Example 6]
A gas adsorbent was obtained in the same manner as in Example 2. Using 10 g of the obtained gas adsorbent, the deterioration test described in (4) above was performed to obtain a gas adsorbent (after deterioration). Using this, the above evaluations (5) to (8) were performed.

This gas adsorbent (degraded) was applied by the method described in the above [Method for producing filter material using gas adsorbent], and the amount of spraying was such that the coating amount of the gas adsorbent (degraded) was 150 g/m ² . was adjusted to produce a filter medium using the gas adsorbent (degraded). Since the gas adsorbent (after deterioration) is for 150 g/m ² , the polyphenol-supported porous body is 135 g/m ² , and the aldehyde reaction agent-supported porous body is 15 g/m ² , so the polyphenol is supported. The mass ratio of the porous material loaded:the porous material supporting the aldehyde-reactive agent was 90:10. The thickness of this filter medium was 0.9 mm.

The above evaluations (9) and (10) were performed using a filter medium using the obtained gas adsorbent (after deterioration).

[Example 7]
A gas adsorbent was obtained in the same manner as in Example 3. Using 10 g of the obtained gas adsorbent, the deterioration test described in (4) above was performed to obtain a gas adsorbent (after deterioration). Using this, the above evaluations (5) to (8) were performed.

This gas adsorbent (degraded) was applied by the method described in the above [Method for producing filter material using gas adsorbent], and the amount of spraying was such that the coating amount of the gas adsorbent (degraded) was 150 g/m ² . was adjusted to produce a filter medium using the gas adsorbent (degraded). Since the gas adsorbent (after deterioration) is for 150 g/m ² , the polyphenol-supported porous body is 75 g/m ² , and the aldehyde reaction agent-supported porous body is 75 g/m ² , so the polyphenol is supported. The mass ratio of the porous material loaded:the porous material supporting the aldehyde-reactive agent was 50:50. The thickness of this filter medium was 0.9 mm.

The above evaluations (9) and (10) were performed using a filter medium using the obtained gas adsorbent (after deterioration).

[Example 8]
A gas adsorbent was obtained in the same manner as in Example 4. Using 10 g of the obtained gas adsorbent, the deterioration test described in (4) above was performed to obtain a gas adsorbent (after deterioration). Using this, the above evaluations (5) to (8) were performed.

This gas adsorbent (degraded) was applied by the method described in the above [Method for producing filter material using gas adsorbent], and the amount of spraying was such that the coating amount of the gas adsorbent (degraded) was 150 g/m ² . was adjusted to produce a filter medium using the gas adsorbent (degraded). Since the gas adsorbent (after deterioration) is for 150 g/m ² , the polyphenol-supported porous body is 60 g/m ² , and the aldehyde reaction agent-supported porous body is 90 g/m ² , so the polyphenol is supported. The mass ratio of the porous body loaded: the porous body supporting the aldehyde-reactive agent was 40:60. The thickness of this filter medium was 0.9 mm.

The above evaluations (9) and (10) were performed using a filter medium using the obtained gas adsorbent (after deterioration).

[Comparative Example 1]
A gas adsorbent was obtained in the same manner as in Example 1, except that the mass ratio of porous body supporting polyphenol:porous body supporting aldehyde reaction agent=100:0. Using the obtained gas adsorbent, the above evaluations (5) to (8) were performed.

The amount of this gas adsorbent is adjusted by the method described in [Production method of filter material using gas adsorbent] above so that the coating amount of the gas adsorbent is 150 g/m ² , and the gas adsorbent is A filter medium was manufactured using Since the gas adsorbent is for 150 g/m ² , the polyphenol-supported porous body is 150 g/m ² , and the aldehyde reaction agent-supported porous body is 0 g/m ² , so the polyphenol-supported porous body is 150 g/m 2 . The mass ratio of body:porous body supporting the aldehyde-reactive agent was 100:0. The thickness of this filter medium was 0.9 mm.

The above evaluations (9) and (10) were performed using the filter medium using the obtained gas adsorbent.

[Comparative Example 2]
A gas adsorbent was obtained in the same manner as in Example 1, except that the mass ratio of porous body supporting polyphenol:porous body supporting aldehyde reaction agent=0:100. Using the obtained gas adsorbent, the above evaluations (5) to (8) were performed.

The amount of this gas adsorbent is adjusted by the method described in [Production method of filter material using gas adsorbent] above so that the coating amount of the gas adsorbent is 150 g/m ² , and the gas adsorbent is A filter medium was manufactured using Since the gas adsorbent is for 150 g/m ² , the polyphenol-supported porous body is 0 g/m ² , and the aldehyde reaction agent-supported porous body is 150 g/m ² , so the polyphenol-supported porous body is 0 g/m 2 . The mass ratio of the body:the porous body supporting the aldehyde-reactive agent was 0:100. The thickness of this filter medium was 0.9 mm.

The above evaluations (9) and (10) were performed using the filter medium using the obtained gas adsorbent.

[Comparative Example 3]
A gas adsorbent was obtained in the same manner as in Comparative Example 2. Using 10 g of the obtained gas adsorbent, the deterioration test described in (4) above was performed to obtain a gas adsorbent (after deterioration). Using this, the above evaluations (5) to (8) were performed.

This gas adsorbent (degraded) was applied by the method described in the above [Method for producing filter material using gas adsorbent], and the amount of spraying was such that the coating amount of the gas adsorbent (degraded) was 150 g/m ² . was adjusted to produce a filter medium using the gas adsorbent (degraded). Since the gas adsorbent (after deterioration) is for 150 g/m ² , the polyphenol-supported porous body is 0 g/m ² , and the aldehyde reaction agent-supported porous body is 150 g/m ² , so the polyphenol is supported. The mass ratio of the porous material loaded:the porous material supporting the aldehyde-reactive agent was 0:100. The thickness of this filter medium was 0.9 mm.

The above evaluations (9) and (10) were performed using a filter medium using the obtained gas adsorbent (after deterioration).

The use of tannic acid-impregnated activated carbon improved the initial removal performance of nonenal by sensory evaluation (Example 1-8). In addition, it was confirmed that the decomposition of aldehyde-reactive agents was suppressed by the antioxidant action of tannic acid, and that yellowing was less likely to occur as a result of color discrimination, and that amine decomposition odor was also suppressed as a result of sensory tests (Examples 5-8). It was confirmed that by mixing an aldehyde adsorbent (amine compound-supported silica) and polyphenol-supported activated carbon, the performance of removing high-molecular-weight aldehydes and low-molecular-weight aldehydes is excellent, and deterioration over time of the aldehyde adsorbent can be suppressed.

The filter media according to the present invention are air filters for purifying the air in the cabins of automobiles and railway vehicles, filters for air purifiers used in healthy homes, pet-friendly condominiums, nursing homes for the elderly, hospitals, offices, etc. It is preferably used as an air filter medium for air conditioner filters, air intake/exhaust filters for OA equipment, building air conditioning filters, industrial clean room filters, and the like.

Claims (10)

A gas adsorbent comprising a polyphenol-supported porous body and an aldehyde-reactive agent-supported porous body. 2. The gas adsorbent according to claim 1, wherein the porous body on which the polyphenol is supported is activated carbon. 3. The gas adsorbent according to claim 1, wherein the porous material supporting the aldehyde-reactive agent is an inorganic porous material. The gas adsorbent according to any one of claims 1 to 3, wherein the aldehyde-reactive agent is an amine compound. 5. The gas adsorbent according to claim 3, wherein the inorganic porous material has an average pore diameter of 0.5 to 100 nm. The gas adsorbent according to any one of claims 1 to 5, wherein said polyphenol is at least one selected from catechin, anthocyanin, tannic acid, rutin, isobravone, poroanthocyanidin and modified products thereof. The gas adsorbent according to any one of claims 2 to 6, wherein the activated carbon has a specific surface area measured by nitrogen gas adsorption BET method of 200 to 1600 m ² /g. Content mass ratio of the polyphenol-supported activated carbon to the aldehyde-reactive agent-supported inorganic porous material (Content mass of the aldehyde-reactive agent-supported inorganic porous material/Content mass of the polyphenol-supported activated carbon ) is 0.05 to 1.00, the gas adsorbent according to any one of claims 3 to 7. A fiber sheet containing the gas adsorbent according to any one of claims 1 to 8. 10. The fiber sheet according to claim 9, wherein the content of said gas adsorbent per unit area is 15-400 g/m ² .