JP2018015710A - Filter material, and air cleaner using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a filter material capable of removing effectively a chemical substance such as formaldehyde, and maintaining the effect stably for a long period; and to provide an air cleaner using the same.SOLUTION: In a filter material 15 containing a pre-stage layer, and a subsequent stage layer provided on the downstream side of an air flow relative to the pre-stage layer, and having a sheet shape formed by close contact of the pre-stage layer and the subsequent stage layer, the pre-stage layer contains a radical scavenger and a fiber bed 20, and the subsequent stage layer contains an absorbent containing an amine-based compound, and a base material layer 19, to be thereby able to collect formaldehyde stably for a long period. Further, an air cleaner including the filter material 15 is also provided.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a filter medium having a deodorizing action such as formaldehyde and an air cleaning device using the same.

  Conventionally, this type of filter medium and an air purifier using the filter medium have the following configurations.

  That is, as shown in FIG. 8, the air filter 101 is processed into a bellows shape so that an air filter medium comprising a base material and an amine compound for removing formaldehyde supported on the base material has a filter shape. The frame 102 is fixed. This air filter is installed in an air flow path in a main body 105 provided with a blower 103 that allows air to pass therethrough and an air supply grill 104.

  Since formaldehyde is released from wallpaper and furniture in a house and causes health problems even at low concentrations, it is desired to be removed as an indoor pollutant. It has been shown that the contact efficiency with air can be improved without increasing the pressure loss by imparting a formaldehyde removal function to the substrate (see, for example, Patent Document 1).

  In addition, resin fibers may cause discoloration when used for a long time, and a method of using a light stabilizer and an ultraviolet absorber has been known as means for improving the weather resistance. In other words, the weather resistance was improved by adding a suitable amount of a hindered amine light stabilizer and an ultraviolet absorber to polypropylene fibers, and melt-mixing them into a fiber composition by a known melt spinning method. A nonwoven fabric can be obtained. This nonwoven fabric can be used as a filter medium for an air cleaning device (see, for example, Patent Document 2).

JP 11-128632 A JP 2006-169273 A

  In such a conventional filter medium and an air purifier using the filter medium, formaldehyde can be removed with a low pressure loss, but it has been desired to further maintain the removal performance. In other words, an amine compound is required to remove formaldehyde, but the amine compound is a basic substance, causing a neutralization reaction when contacted with an acidic substance contained in air particles, resulting in a decrease in performance. was there. In addition, air contains active components such as ozone, OH radicals, and NO radicals generated by ultraviolet rays. In an air purifier that performs processing by sucking a large amount of air, these active components are not contained. There existed the subject that it reacted with an amine compound and performance deteriorated easily.

  Further, the conventional means for improving weather resistance only shows a method for preventing discoloration of the nonwoven fabric itself, and does not mention an effective method for removing formaldehyde. For example, it was not possible to obtain information on how to dispose polypropylene fibers, light stabilizers, ultraviolet absorbers, and amine compounds.

  Therefore, the present invention solves the above-described conventional problems, and provides a filter medium that can effectively remove chemical substances such as formaldehyde and can stably maintain the effect for a long period of time, and an air purifier using the filter medium. It is aimed.

  In order to achieve this object, the present invention provides a filter medium including a front layer and a rear layer provided downstream of the air flow with respect to the front layer, the front layer including a radical scavenger. A layer of fibers containing and capable of collecting particles, wherein the latter layer is a fiber layer containing an adsorbent containing an amine compound, and is a sheet in which the former layer and the latter layer are in close contact with each other In this way, the intended purpose is achieved.

  According to the present invention, the filter medium includes a pre-stage layer and a post-stage layer provided downstream of the air flow with respect to the pre-stage layer, and the pre-stage layer includes a radical scavenger and can collect particles. A fiber layer, and the latter layer is a fiber layer containing an adsorbent containing an amine-based compound, and the former layer and the latter layer are formed into a sheet-like form, thereby providing formaldehyde and the like. Thus, it is possible to provide a filter medium that can effectively remove the chemical substances and can maintain the effect stably for a long period of time, and an air cleaning device using the filter medium.

The perspective view which shows the installation state of the air purifying apparatus of Embodiment 1 of this invention. Cross section of the air cleaning device Perspective view of the air filter Configuration diagram of filter media used in the air filter Schematic sectional view of the filter media An enlarged schematic cross-sectional view of the filter medium The perspective view which shows the air filter of Embodiment 2 of this invention. A perspective view showing a conventional air cleaning device

  The filter medium according to claim 1 of the present invention is a filter medium including a front layer and a rear layer provided on the downstream side of the airflow with respect to the front layer, and the front layer includes a radical scavenger, And a layer of fibers capable of collecting particles, wherein the latter layer is a fiber layer containing an adsorbent containing an amine compound, and has a sheet shape in which the former layer and the latter layer are in close contact with each other. It is a thing.

  Thereby, after the acidic substance particles in the air are collected in the fiber layer in the upstream layer, the formaldehyde in the air comes into contact with the amine compound in the downstream layer. Therefore, the effect that the basic amine compound can maintain the effect stably for a long period of time can be obtained without causing a neutralization reaction to deteriorate the performance. In addition, the air contains active components such as ozone, OH radicals, and NO radicals generated by ultraviolet rays, but these active components are reduced by the radical scavenger contained in the fiber layer that is the previous layer. Therefore, the performance deterioration of the amine compound contained in the latter layer is suppressed, and an effect that the effect can be stably maintained for a long period of time can be obtained.

  In the filter medium according to claim 2, the amine compound is applied to the surface of the fibers constituting the latter layer.

  As a result, the applied amine compound is exposed over a wide range on the surface of the filter medium constituting the latter layer, so that the contact area with formaldehyde is improved, and the effect of removing chemical substances can be further improved. is there.

  In the filter medium according to claim 3, the radical scavenger contains one or more of hindered amines, hindered phenols, and benzotriazoles.

  Thereby, the effect which prevents discoloration of a fiber layer can be acquired with the effect which reduces the radicals contained in the air and suppresses the performance degradation of an amine compound.

  The filter medium according to claim 4 is such that the content of the amine compound in the latter layer is high on the side of the close contact surface with the front layer, and decreases as the distance from the close contact surface increases.

  As a result, there is only a small amount of amine compound on the surface exposed to the air far from the contact surface, and the rate at which the amine compound reacts and decreases during storage of the filter medium is reduced. be able to. Compared to the case of uniform application, the ratio of the remaining amine compound can be maintained at a predetermined level, and the initial performance can be maintained over a long period of time.

  An air cleaning device according to claim 5 includes a main body case having an intake port and an exhaust port, a blower provided in the main body case, an air filter provided between a suction side of the blower and the intake port, And the air filter is made of the filter medium according to any one of claims 1 to 4.

  Thereby, it is possible to provide an air purifier that can effectively remove indoor chemical substances such as formaldehyde and can maintain the effect stably for a long period of time.

  The air purifier according to claim 6 is the air purifier, wherein the air filter is disposed downstream of the base layer in addition to the pre-filter as the front layer and the base layer as the rear layer. The fiber layer is a fiber layer different from the arranged preceding layer, and includes a fiber layer containing a radical scavenger, and a frame portion, and the prefilter is a fiber different from the base layer and the preceding layer. It is characterized by being bonded together with the above layer through the frame portion and arranged on the air inlet side of the main body case.

  As a result, as viewed from the base material layer, there is a radical scavenger contained in the upstream layer on the upstream side, and a radical scavenger contained in a fiber layer different from the upstream layer on the downstream side. It is possible to obtain an air purifier that is less likely to deteriorate in performance even when the operation of the apparatus is stopped and that can stably maintain the collection performance for a long period of time.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(Embodiment 1)
As shown in FIG. 1, the air purification apparatus 1 shown in this Embodiment 1 is installed on the floor 3 of the room 2, and can perform an air purification operation. Formaldehyde is generated from the wallpaper 4 or the furniture 5 and has a higher specific gravity than air. Therefore, the formaldehyde is present in a high concentration near the floor 3 of the indoor air. When a person moves, outdoor air flows in by opening and closing the window 6, and acidic substance particles generated by the action of outdoor ultraviolet rays or active components such as ozone, OH radicals, and NO radicals enter the room.

  As shown in FIG. 2, the air cleaning device 1 of this embodiment includes a blower 8 and an air filter 9 in a main body case 7. The main body case 7 has a substantially vertically long box shape. The main body case 7 is provided with a substantially square-shaped air inlet 10 on the side surface on the front side thereof, and a substantially square-shaped air outlet 11 is provided on the top surface of the main body case 7. Yes.

  The air blowing means 8 is provided in an air passage between the air inlet 10 and the air outlet 11 of the main body case 7, a scroll-shaped casing 12, and a blade 13 that is a centrifugal air fan provided in the casing 12. And the electric motor 14 for rotating the blade 13.

  The air filter 9 is located near the air inlet 10 of the main body case 7. The indoor air containing formaldehyde sucked into the main body case 7 from the air inlet 10 by the air blowing means 8 is blown to the air outlet 11 through the air filter 9. That is, air containing formaldehyde in the room is cleaned by the air filter 9 and blown into the room.

  As shown in FIGS. 3 and 4, the air filter 9 includes a pleated filter medium 15 and a frame-shaped shape holding portion 16 provided on the outer periphery of the filter medium 15 to hold the filter medium 15 in a pleated shape. Formed from. The shape holding part 16 is formed from a square-shaped frame part 17 and an adhesive member 18 provided between the frame part 17 and the filter medium 15. That is, the frame portion 17 is located at the periphery of the pleated filter medium 15, and the pleated filter medium 15 is fixed to the frame portion 17 by the adhesive member 18.

  As shown in FIGS. 5 and 6, the filter medium 15 before pleating is provided with a base material layer 19 and a fiber layer 20 provided on the upstream side surface of the air flow blown to the base material layer 19. .

  The base material layer 19 is formed of fibers containing at least one of glass fiber, pulp fiber, resin fiber, carbon fiber, and inorganic fiber. As a manufacturing method of the base material layer 19, a spunbond method, a dry type or a wet type is used. Examples include a papermaking method, a melt blown method, a spunbond method, an airlaid method, and a thermal bond method. In particular, the wet papermaking method is preferable. With this manufacturing method, as shown in FIG. 6, the base material layer 19 has a density gradient so as to gradually decrease from dense to coarse when viewed from the fiber layer 20 side. You can have it. In the example of FIG. 6, the number of fibers in the dense base material layer 19 in which the base material layer 19 and the fiber layer 20 are in close contact with each other is 9, and the fibers in the loose base material layer 19 away from the fiber layer 20. The number is five. In the base material layer 19 having such a configuration, the adsorbent content on the surface where the base material layer 19 and the fiber layer 20 are in close contact can be easily obtained by applying an adsorbent containing an amine compound to the fibers. It is possible to make a configuration in which the content is relatively increased and the content decreases as the distance from the contact surface increases.

The basis weight of the base material layer 19 is preferably 10 to 100 g / m ² . When the basis weight is less than 10 g / m ² , the bending resistance of the base material layer 19 decreases, so that it becomes difficult to reduce the productivity of the pleating process and to maintain the filter shape. If it exceeds 100 g / m ² , the pressure loss of the base material layer 19 becomes large, so that the pressure loss of the air filter 9 becomes large, which is not preferable.

  The average fiber diameter of the fibers constituting the base material layer 19 is preferably 1 to 50 μm. When the average fiber diameter is less than 1 μm, the strength of the fiber is low and the strength as a reinforcing material is insufficient. When the average fiber diameter exceeds 50 μm, the thickness of the base material layer 19 is increased, resulting in structural pressure loss due to pleating. Since it becomes large, it is not preferable.

  The fiber layer 20 may be made of the same material as the base material layer 19. The fiber layer 20 and the base material layer 19 can be integrated using an adhesive. When a heat-meltable fiber is used for the fiber layer 20, the fiber layer 20 is melted by heating and bonded to the base material layer 19, so that the filter medium 15 can be integrated.

  The average fiber diameter of the fibers constituting the fiber layer 20 is preferably 1 to 10 μm. If the average fiber diameter is less than 1 μm, the self-supporting property is poor, and in order to form the fiber layer 20, it is necessary to increase the weight per unit area. As a result, the pressure loss increases, which is not preferable. On the other hand, if it exceeds 10 μm, the collection efficiency of the fiber layer 20 is lowered, which is not preferable. In particular, a preferable fiber diameter is 2 to 6 μm.

  The fiber diameter of the fiber layer 20 is preferably narrower than that of the base material layer 19, whereby a balanced filter medium with high dust collection efficiency and low pressure loss can be obtained. The filter medium 15 thus prepared has a pressure loss greater in the fiber layer 20 and smaller in the base material layer 19. For example, the pressure loss when air is flowed at a flow rate of 5.3 cm / s is about 40 Pa for the fiber layer 20 and about 3 Pa for the base material layer 19.

  For the base material layer 19 and the fiber layer 20, general resin materials and natural fiber materials can be used. For example, polyacrylonitrile (PAN), polypropylene (PP), polyethylene (PE), polyethylene oxide (PEO), polyethylene naphthalate (PEN), polyethylene terephthalate (PET), polyethersulfone (PES), polymethacrylic acid, polymethacrylic Methyl acid, polyvinylidene fluoride (FVDF), polyvinyl chloride (PVC), polytetrafluoroethylene, polyvinyl alcohol (PVA), polycarbonate (PC), polystyrene, polyamide, polyimide, polyamideimide, aramid, polyimide benzazole, polyglycol Examples include acid (PGA), polylactic acid (PLA), polyurethane (PU), cellulose compound, polypeptide, nylon and the like.

The adsorbent containing the amine compound of the present invention contains an amine compound in at least a part of the components. It is known that an amine compound and formaldehyde cause the following irreversible chemical reaction. For example,
R-ΝH ₂ + HCHO
→ RN = CH ₂ + H ₂ O (shiff base)
2H ₂ NCONH ₂ (urea) + HCHO
→ NN ₂ CONHCH ₂ NHCONH ₂ (dimethylol urea)
NH ₂ —NH ₂ (hydrazine) + 2HCΗO
→ CΗ ₂ = N-N = CΗ ₂
It reacts like this. Since these reactions occur similarly in gas components having an aldehyde group, they have reactivity with aldehyde compounds such as acetaldehyde and propionaldehyde in addition to formaldehyde. In general, aldehydes are unpleasant odor substances, and the filter medium of the present invention can also be applied to deodorization intended for aldehydes.

  Since the above reaction involves chemical reaction, it is called chemisorption and is distinguished from physical adsorption such as activated carbon. In the case of chemical adsorption, since the adsorbed aldehydes are not re-released, there is an advantage that aldehydes can be removed stably. On the other hand, the amine compound is a basic substance, and when it comes into contact with an acidic substance in the air, there is a problem that a neutralization reaction occurs and the performance deteriorates. The acidic component is a mist such as nitric acid / sulfuric acid or acetic acid, or suspended particles containing these components. In addition, air contains active components such as ozone, OH radicals, and NO radicals generated by ultraviolet rays. In an air purifier that performs processing by sucking a large amount of air, these active components are not contained. There existed the subject that it reacted with an amine compound and performance deteriorated easily. Therefore, in this invention, after removing active ingredients, such as an acidic substance and OH radical, from the air inhaled by the main body of the air purifying apparatus 1 with the fiber layer 20 containing a radical scavenger, it is contained in the base material layer 19. The filter medium 15 and the air purifier 1 using the filter medium 15 are configured to remove aldehydes such as formaldehyde with an adsorbent containing an amine compound, and to maintain the collection performance stably for a long period of time. is there.

  As the radical scavenger contained in the fiber layer 20 of the present invention, a general light stabilizer / antioxidant can be used. In particular, a hindered amine light stabilizer, a hindered phenol antioxidant, a benzotriazole light stabilizer, and the like can be used.

  An example of a light stabilizer / antioxidant that can be used as the radical scavenger of the present invention is given below. As a commercial item, for example, TINUVIN 111 (manufactured by BASF Japan; N, N ′, N ″, N ′ ″-tetrakis- (4,6-bis- (butyl- (N-methyl-2,2,6 , 6-Tetramethylpiperidin-4-yl) amino) -triazin-2-yl) -4,7-diazadecane-1,10-diamine (45%), dimethyl succinate and 4-hydroxy-2,2,6 , 6-tetramethyl-1-piperidineethanol polymer (55%)), Uvinul 5050H (manufactured by BASF Japan; sterically hindered amine oligomer), CHIMASSORB 2020 (manufactured by BASF Japan; dibutylamine-1,3) , 5-Triazine-N, N′-bis (2,2,6,6-tetra Polycondensation product of til-4-piperidyl-1,6-hexamethylenediamine and N- (2,2,6,6-tetramethyl-4-piperidyl) butylamine), CHIMASSORB 944 (manufactured by BASF Japan; poly [{6 -(1,1,3,3-tetramethylbutyl) amino-1,3,5-triazine-2,4-diyl} {(2,2,6,6-tetramethyl-4-piperidyl) imino] hexa Methylene {(2,2,6,6-tetramethyl-4-piperidyl) imino}], CYASORB UV-3346 (manufactured by Cytec; poly [(6-morpholino-s-triazine-2,4-diyl) [2 , 2,6,6-tetramethyl-4-piperidyl] imino] -hexamethylene [(2,2,6,6-tetramethyl-4-piperidyl) imino]), CYASO B UV-3529 (manufactured by Cytec; 1,6-hexanediamine-N, N′-bis (1,2,2,6,6-pentamethyl-4-piperidyl) and morpholine-2,4,6-trichloro -1,3,5-triazine methylated polymer), Hastabin N30 (manufactured by Glariant); 2,2,4,4-tetramethyl-7-oxa-3,20-diaza-20 (2,3-epoxy -Propyl) dispiro- [5,1,11,2] -heneicosan-21-one polymer), vin770 (manufactured by BASF Japan), Uvinul 4050 (manufactured by BASF Japan), TINUVIN234 (manufactured by BSAF Japan; 2 -(2H-benzotriazol-2-yl) -4-6-bis (1-methyl-1-phenylethyl) phenol), Uvinul 030 (manufactured by BASF Japan; 1,3-bis-{[(2′-cyano-3 ′, 3-diphenylacryloyl) oxy] -2,2-bis-[(2-cyano-3 ′, 3-diphenyl) Acryloyl) oxy] methyl} propane), TINUVIN 326 (manufactured by BASF Japan; 2- [5-chloro (2H) -benzotriazol-2-yl] -4-methyl-5- (tert-butyl) phenol), TINUVIN 329 (Manufactured by BASF Japan; 2- (2H) -benzotriazol-2-yl) -4- (1,1,3,3-tetramethylbutylphenol, TINUVIN 1577 (manufactured by BASF Japan; 2- (4,6- Diphenyl-1,3,5-triazin-2-yl) -5-[(hexyl) oxy] -phenol), CYASOR UV-531 (Cytec; manufactured by 2-hydroxy-4-n-octoxybenzophenone, IRGANOX 565 (BASF Japan Ltd.), Irganox 1035 (manufactured by BASF Japan Ltd.), and the like.

  As a means for including the adsorbent containing the amine compound in the base material layer 19, the adsorbent is dispersed in an aqueous solution, a small amount of a surfactant and a binder are added, and then the base material layer 19 is added to the aqueous solution. , A method of spraying an aqueous solution onto the base material layer 19, a method of applying the aqueous solution to the base material layer 19 with a brush or a roller, and the like. Similarly, the means for including the radical scavenger in the fiber layer 20 is also a method or solution in which the radical scavenger is dispersed in an organic solvent, an ultraviolet additive or the like is added, and the fiber layer 20 is immersed in this solution. And the like, and a method of applying an aqueous solution to the fiber layer 20 with a brush or a roller.

  By spraying only from one surface of the base material layer 19 and drying, the concentration of the adsorbent on the sprayed surface can be increased. By making the surface having a high adsorbent concentration of the base material layer 19 into a close contact surface with the fiber layer 20, the content of the amine compound on the close contact surface between the base material layer 19 and the fiber layer 20 is high, and from the close contact surface A filter medium 15 whose content decreases as the distance increases can be obtained.

  When the air filter 9 is installed in the air cleaning device 1, the fiber layer 20 and the base material layer 19 are set in order from the air inlet 10 side. That is, the air filter 9 includes a fiber layer that is a preceding layer, that is, a fiber layer 20, and a fiber layer that is a subsequent layer provided downstream of the air flow with respect to the preceding layer, that is, a base material layer 19. is there.

  Thus, after removing active components such as acidic substances and OH radicals from the air sucked into the main body of the air cleaning device 1 with the fiber layer 20 containing the radical scavenger, the amine system contained in the base material layer 19 The filter medium 15 and the air purifier 1 using the same can be provided that can remove aldehydes such as formaldehyde with an adsorbent containing a compound, and can stably maintain the collection performance for a long period of time.

(Embodiment 2)
Description of the same parts as those in Embodiment 1 is omitted. As shown in FIG. 7, the air filter 9 used in the air cleaning device shown in the second embodiment includes a base material layer 19 and a fiber layer 20 that are processed into a pleat shape, a frame portion 17, and a pre-filter. A filter 21 is provided.

  The pre-filter 21 is a non-woven fiber layer having a fiber diameter and openings necessary for collecting coarse dust, and is obtained by spraying and drying a radical scavenger. The pre-filter 21 can be made of a general nonwoven fabric or a net such as a net having a performance capable of collecting acidic substances contained in particles in the air, and preferably a static electricity capable of collecting particles using electric power. An electric filter may be used.

  By applying an adhesive to the pre-filter 21 so that no gap is generated in the frame portion 17 and bonding the pre-filter 21, the air filter 9 integrated with the pre-filter 21 can be obtained. Here, if there is a gap between the pre-filter 21 and the frame portion 17, when the air cleaning device 1 sucks air, air containing radicals comes into contact with the adsorbent through the gap with low pressure loss. The problem arises. The base material layer 19 contains an adsorbent containing at least an amine compound, and the fiber layer 20 contains a radical scavenger.

  When the air filter 9 is installed in the air cleaning device 1, the prefilter 21, the base material layer 19, and the fiber layer 20 are installed in order from the intake port 10 side. That is, here, the filter medium 15 includes a pre-filter 21 that is a fiber layer that contains a radical scavenger as a front layer and can collect particles, and a base material layer 19 as a back layer and the base material layer. The fiber layer 20 is a fiber layer different from the preceding layer disposed on the downstream side of the fiber, and is bonded together with the fiber layer 20 which is a fiber layer containing a radical scavenger via the frame portion 17. .

  Thereby, after removing active components, such as an acidic substance and OH radical, from the air inhaled by the main body of the air purifying apparatus 1 with the prefilter 21 containing a radical scavenger, the amine system contained in the base material layer 19 An adsorbent containing a compound can remove aldehydes such as formaldehyde, and can provide a filter medium that can stably maintain the collection performance for a long period of time and an air purifier using the filter medium.

  In particular, the pre-stage 21 includes a pre-filter 21 that includes a radical scavenger as a pre-stage layer and is capable of collecting particles, and is disposed on the downstream side of the base layer 19 as a post-stage layer and the base layer. The fiber layer 20, which is a fiber layer different from the layer and is a fiber layer containing a radical scavenger, is bonded together through the frame portion 17, so that the air passing through the air filter 9 can be integrated. All of the air that passes therethrough passes through the prefilter 21, the base material layer 19, and the fiber layer 20 in order without bypassing a specific layer where some pressure is high. That is, even when the opening of the pre-filter 21 is made smaller than that of the base material layer 19, the air that has passed through the pre-filter 21 can be passed through the base material layer 19 more reliably. An effect of removing aldehydes can be exhibited.

  In addition, as viewed from the base material layer 19, the upstream side contains the radical scavenger contained in the prefilter 21, and the downstream side contains the radical scavenger contained in the fiber layer 20, so it is contained in the base material layer 19. Amine-based compounds are not directly exposed to active components such as acidic substances and OH radicals not only from the upstream side but also from the downstream side, and the operation of the air purification device is unlikely to deteriorate even when the air purification device 1 is stopped. Sometimes, the performance of the adsorbent contained in the base material layer 19 is hardly deteriorated, and an effect that the collection performance can be stably maintained for a long period of time can be obtained.

  Note that the prefilter 21, that is, the fiber layer that can collect particles as the preceding layer may be the same as the fiber layer 20, but may have a larger opening of the filter medium than the fiber layer 20.

  A filter medium according to the present invention and an air cleaning device using the filter medium include a base material layer and a fiber layer capable of collecting particles, wherein the base material layer includes an adsorbent containing an amine compound. In addition, the fiber layer contains a radical scavenger, and the base material layer and the fiber layer are in a sheet-like form, thereby effectively removing chemical substances such as formaldehyde and having a long-term stable effect. It can be sustained and can be applied to ventilation devices that require similar functions.

DESCRIPTION OF SYMBOLS 1 Air purifier 2 Room 3 Floor 4 Wallpaper 5 Furniture 6 Window 7 Main body case 8 Air blower 9 Air filter 10 Intake port 11 Exhaust port 12 Casing 13 Blade 14 Electric motor 15 Filter medium 16 Shape holding part 17 Frame part 18 Adhesive member 19 Base Material layer 20 Fiber layer 21 Pre-filter 101 Air filter 102 Frame body 103 Blower 104 Air supply grill 105 Main body

Claims (6)

A filter medium including a front layer and a rear layer provided on the downstream side of the airflow with respect to the front layer,
The pre-stage layer is a fiber layer containing a radical scavenger and capable of trapping particles,
The filter layer, wherein the latter layer is a fiber layer containing an adsorbent containing an amine compound, and is formed into a sheet shape in which the former layer and the latter layer are in close contact with each other. The filter medium according to claim 1, wherein the amine compound is applied to a surface of a fiber constituting the latter layer. The filter medium according to claim 1 or 2, wherein the radical scavenger contains one or more of hindered amines, hindered phenols, and benzotriazoles. 4. The filter medium according to claim 1, wherein the content of the amine-based compound in the subsequent layer is high on a close contact surface side with the pre-stage layer and decreases as the distance from the close contact surface increases. 5. . A main body case having an intake port and an exhaust port, a blower provided in the main body case, and an air filter provided between a suction side of the blower and the intake port, wherein the air filter includes: 4. An air purifier comprising the filter medium according to any one of 4 above. 6. The air purifier according to claim 5, wherein the air filter includes a prefilter as the front layer and a base layer as the rear layer, and the front layer disposed on the downstream side of the base layer. Comprises a fiber layer containing a radical scavenger and a frame part, and the pre-filter includes the frame part together with a fiber layer different from the base layer and the previous layer. The air purifier is characterized in that it is bonded so as to be integrated with each other and disposed on the air inlet side of the main body case.