CN109475799B

CN109475799B - Filter medium and air cleaning device using the same

Info

Publication number: CN109475799B
Application number: CN201780045971.XA
Authority: CN
Inventors: 稻垣纯; 辻由浩; 小森大辅; 加藤港
Original assignee: Panasonic Intellectual Property Management Co Ltd
Current assignee: Panasonic Intellectual Property Management Co Ltd
Priority date: 2016-07-28
Filing date: 2017-06-27
Publication date: 2021-01-19
Anticipated expiration: 2037-06-27
Also published as: JP6738998B2; CN109475799A; JP2018015710A; WO2018020932A1

Abstract

The filter medium (15) according to the present invention is characterized by comprising: a front layer; and a rear-stage layer located downstream of the front-stage layer in the air flow, the front-stage layer being a layer containing fibers capable of trapping particles and containing a radical trapping agent, the rear-stage layer being a layer containing fibers containing an adsorbent containing an amine compound, the filter medium being formed in a sheet shape in which the front-stage layer and the rear-stage layer are in close contact with each other.

Description

Filter medium and air cleaning device using the same

Technical Field

The present invention relates to a filter material and an air cleaning device using the same.

Background

Conventionally, a filter medium having a deodorizing action and a removing action for formaldehyde and the like and an air cleaning apparatus using the filter medium have the following configurations.

Fig. 8 is a perspective view showing a conventional air cleaning device. That is, as shown in fig. 8, the filter medium 150 includes a base material and an amine compound supported on the base material for removing formaldehyde. The air filter 101 is a member in which the filter medium 150 is corrugated to have a filter shape and is fixed by the frame 102. The air cleaning device 100 is a device in which the air filter 101 is provided in an air flow path in a main body 105 having a blower 103 for passing air and an intake grill 104.

Formaldehyde is released from wallpaper, furniture, etc. in houses, and even in low concentrations, causes health problems, and therefore, it is desired to remove formaldehyde as an indoor pollutant. For example, it is shown that by providing a substrate formaldehyde removal function, the contact efficiency between the air filter 101 and the air can be improved without increasing the pressure loss of the air filter 101 (see, for example, patent document 1).

In addition, the resin fiber as a base material may be discolored after long-term use. In order to prevent discoloration of the resin fibers, that is, to improve the weather resistance thereof, a method of using a light stabilizer and an ultraviolet absorber is known. That is, a proper amount of hindered amine light stabilizer and ultraviolet absorber are added to polypropylene fibers as resin fibers, and melt-mixed to prepare a fibrous resin composition by a known melt spinning method, thereby obtaining a nonwoven fabric having improved weather resistance. The nonwoven fabric can be used as a filter medium of an air cleaning device (see, for example, patent document 2).

Documents of the prior art

Patent document

Patent document 1: japanese laid-open patent publication No. 11-128632

Patent document 2: japanese patent laid-open No. 2006 and 1699273

Disclosure of Invention

In such a conventional filter medium and an air cleaning apparatus using the filter medium, although formaldehyde can be removed at a low pressure loss, it is desired to maintain the removal performance more continuously. That is, the amine compound is necessary for removing formaldehyde, but the amine compound is a basic substance and causes a neutralization reaction when it comes into contact with an acidic substance contained in the particles in the air. Therefore, there is a problem that the amine compound in the filter medium is reduced, and the formaldehyde removal performance of the air cleaner is lowered. In addition, the air contains active components such as ozone, OH radicals, and NO radicals generated by ultraviolet rays. Therefore, in an air cleaning device which sucks and treats a large amount of air, these active ingredients react with amine compounds, and there is a problem that the formaldehyde removal performance is easily deteriorated.

In addition, the conventional weather resistance improving methods only show a method for preventing discoloration of the nonwoven fabric fiber itself, and do not relate to an effective use method for removing formaldehyde. For example, information on how to arrange polypropylene fibers, light stabilizers, ultraviolet absorbers, and amine compounds is not obtained.

The present invention is directed to solving the problems of the prior art described above, and an object of the present invention is to provide: provided are a filter medium which can effectively remove chemical substances such as formaldehyde and can stably maintain the effect in long-term use, and an air cleaning device using the filter medium.

In order to achieve the object, a filter medium according to the present invention includes: a front layer; and a rear layer located downstream of the front layer in the air flow, the front layer being a layer containing fibers capable of trapping particles and containing a radical trapping agent, the rear layer being a layer containing fibers containing an adsorbent containing an amine compound, the filter medium being formed in a sheet shape in which the front layer and the rear layer are closely combined. Whereby the desired object can be achieved.

According to the present invention, it is possible to provide a filter medium that can effectively remove chemical substances such as formaldehyde and can stably maintain the effect for a long period of use, and an air cleaning device using the filter medium.

Drawings

Fig. 1 is a perspective view showing an installation state of an air cleaning device according to embodiment 1 of the present invention.

Fig. 2 is a cross-sectional view of the air cleaning device.

Fig. 3 is a perspective view of the air filter.

Fig. 4 is a structural diagram of a filter medium used in the air filter.

Fig. 5 is a schematic cross-sectional view of the filter medium.

Fig. 6 is an enlarged view of fig. 5.

Fig. 7 is a perspective view showing an air filter according to embodiment 2 of the present invention.

Fig. 8 is a perspective view showing a conventional air cleaning device.

Detailed Description

A filter medium according to a first aspect of the present invention is a filter medium including a front-stage layer and a rear-stage layer located downstream of the front-stage layer in an air flow, the front-stage layer being a layer containing fibers capable of trapping particles and containing a radical trapping agent, the rear-stage layer being a layer containing fibers of an adsorbent containing an amine compound, the filter medium being formed into a sheet shape in which the front-stage layer and the rear-stage layer are bonded to each other.

Thus, the amine compound contained in the rear layer is less likely to react with active components in the air, such as oxidizing substances, ozone, OH radicals, and NO radicals. Therefore, the effect of stably maintaining the performance of removing formaldehyde and the like in long-term use can be obtained.

In the filter medium according to the second aspect, the amine compound is applied to the surface of the fibers constituting the rear-stage layer.

Thus, the amine compound to be applied is exposed over a wide range on the surface of the filter medium constituting the rear stage layer. Therefore, the contact area with formaldehyde can be increased, and the effect of removing chemicals such as formaldehyde can be further improved.

In the filter medium according to the third aspect, the radical scavenger contains at least one of a hindered amine, a hindered phenol, and a benzotriazole.

Thus, active components such as ozone and radical species can be removed in the front layer, and the air from which the radical species have been removed can be blown onto the rear layer. Therefore, the effect of reducing the radical species contained in the air to suppress the deterioration of the performance of the amine compound can be obtained. In addition, the effect of preventing discoloration of the fiber layer can also be obtained.

In the filter medium according to the fourth aspect, the content of the amine compound in the rear-stage layer is higher on the side of the bonding surface with the front-stage layer, and is lower as the distance from the bonding surface increases.

Thus, only a small amount of amine compound is present on the surface exposed to air away from the adhesion surface, and the proportion of amine compound that reacts with the radical species and decreases during storage of the filter medium can be reduced. Therefore, the ratio of the amine compound remaining can be kept at a predetermined value as compared with the case of uniform coating, and the initial performance can be maintained for a long period of time.

Further, an air cleaning device according to a fifth aspect includes: a main body housing having an air suction port and an air discharge port; a blower disposed within the main body case; and an air filter disposed between the suction side of the blower and the suction port. The air cleaning device is characterized in that: an air filter comprises a filter material according to the first aspect.

This makes it possible to provide an air cleaning device that can effectively remove chemical substances such as formaldehyde in a room and can stably maintain the effect over a long period of use.

In the air cleaning device according to the sixth aspect, the air filter includes: a prefilter as a front-end layer; a base material layer as a rear layer; and a fiber layer arranged on the downstream side of the base material layer and different from the preceding layer, the fiber layer containing a radical trapping agent; and a frame portion. The air cleaning device is characterized in that: the prefilter, the base material layer, and the layer of fibers different from the first stage layer are all integrally joined via the frame portion, and are disposed on the intake port side of the main body casing.

Accordingly, when viewed from the base material layer, the radical trapping agent contained in the front-stage layer is present on the upstream side, and the radical trapping agent contained in the fiber layer different from the front-stage layer is present on the downstream side, so that the performance is not easily deteriorated even when the air cleaning apparatus is stopped, and the air cleaning apparatus capable of stably maintaining the trapping performance in long-term use can be obtained.

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

(embodiment mode 1)

Fig. 1 is a perspective view showing an installation state of an air cleaning device according to embodiment 1. As shown in fig. 1, the air cleaning device 1 according to the present embodiment is installed on a floor 3 of a room 2, and is capable of performing an air cleaning operation. Formaldehyde is generated from wallpaper 4 or furniture 5, etc. The generated formaldehyde is heavier than air in specific gravity and thus exists in a high concentration state near the floor 3. The outdoor air contains active components such as acidic substance particles, ozone generated by the action of ultraviolet rays, OH radicals, NO radicals, and the like. Therefore, when a person enters or exits the room, the active components such as acidic substance particles, ozone, OH radicals, and NO radicals are taken into the room by the air flowing from the outside of the room through the opening and closing of the window 6.

Fig. 2 is a sectional view of an air cleaning device according to embodiment 1. As shown in fig. 2, the air cleaning device 1 of the present embodiment includes a blower unit 8 and an air filter 9 in a main body casing 7. The main body casing 7 is substantially vertically long box-shaped, and includes an intake port 10 and an exhaust port 11. The air inlet 10 is substantially rectangular and is provided in the front side surface of the main body casing 7. Further, the exhaust port 11 is provided in the top surface portion of the main body casing 7.

The blower 8 is provided in an air passage between the inlet 10 and the outlet 11 of the main body case 7. The blowing section 8 is formed of a volute-shaped casing 12, a blade 13 as a centrifugal blowing fan provided in the casing 12, and a motor 14 for rotating the blade 13.

The air filter 9 is located in the vicinity of the air inlet 10 of the main body casing 7. The air in the room containing formaldehyde sucked into the main body casing 7 through the air inlet 10 is blown to the air outlet 11 through the air filter 9 by the air blowing unit 8. That is, the air containing formaldehyde in the room is cleaned by the air filter 9 and then blown into the room by the blowing unit 8. The air filter 9 can remove formaldehyde and can also collect particles such as coarse dust. The details are as follows.

Fig. 3 is a perspective view of an air filter according to embodiment 1. Fig. 4 is a structural diagram of a filter medium used in the air filter according to embodiment 1. As shown in fig. 3 and 4, the air filter 9 is formed of a filter medium 15 having a pleated shape and a shape retaining portion 16, and the shape retaining portion 16 is a frame-shaped member provided on the outer periphery of the filter medium 15 to retain the filter medium 15 in the pleated shape. The shape retaining portion 16 is formed of a frame 17 shaped like a square and a joining member 18, and the joining member 18 is provided between the frame 17 and the filter medium 15. That is, the frame 17 is located around the filter medium 15 having a pleated shape, and the filter medium 15 is fixed to the frame 17 by the joining member 18.

Fig. 5 is a schematic cross-sectional view of a filter medium according to embodiment 1. Fig. 6 is an enlarged view of fig. 5. As shown in fig. 5 and 6, the filter medium 15 before the pleating process includes a base material layer 19 and a fiber layer 20. The fiber layer 20 is provided on the upstream side of the air flow blowing toward the base material layer 19. That is, the filter medium is disposed in the air cleaning device 1 so that the fiber layer 20 is on the upstream side with respect to the flow of the air.

The base material layer 19 is formed of fibers containing at least one of glass fibers, pulp fibers, resin fibers, carbon fibers, and inorganic fibers. Examples of the method for producing the substrate layer 19 include a spunbond method, a dry or wet paper making method, a melt blowing method, a spunbond method, an air-laid method, and a thermal bond method. The wet papermaking method is particularly preferable. According to this production method, as shown in fig. 6, the base material layer 19 can have a density gradient gradually decreasing from dense to sparse from the fiber layer 20 side when viewed in the thickness direction. That is, the density of the fibers constituting the base material layer 19 is the closest to the joint surface with the fiber layer 20, and gradually becomes thinner as the distance from the joint surface increases. In the example of fig. 6, the number of fibers in the dense substrate layer 19 in which the substrate layer 19 and the fiber layer 20 are in close contact with each other is 9. The number of fibers of the base material layer 19 away from the sparse portion of the fiber layer 20 is 5. In the substrate layer 19 configured as described above, when the adsorbent containing the amine compound is applied to the fibers, the adsorbent content of the surface of the substrate layer 19 in close contact with the fiber layer 20 can be easily increased relatively. That is, the content of the amine compound in the substrate layer 19 can be made higher on the side of the bonding surface with the fiber layer 20 and lower as the distance from the bonding surface increases.

Here, the weight per unit area of the base material layer 19 is preferably 10 to 100g/m². The weight per unit area is less than 10g/m²In this case, the rigidity and flexibility of the base material layer 19 are reduced, which causes a reduction in the productivity of the pleating process and makes it difficult to maintain the filter shape. On the other hand, the weight per unit area exceeds 100g/m²In this case, the pressure loss of the base material layer 19 increases, and therefore the pressure loss of the air filter 9 increases, which is not preferable.

The average fiber diameter of the fibers constituting the base material layer 19 is preferably 1 to 50 μm. If the average fiber diameter is less than 1 μm, the strength of the fibers is low, and the strength as a reinforcing material is insufficient. On the other hand, if the average fiber diameter exceeds 50 μm, the thickness of the base material layer 19 becomes large, and the structural pressure loss due to the crimping process becomes large, which is not preferable.

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

Here, the average fiber diameter of the fibers constituting the fiber layer 20 is preferably 1 to 10 μm. When the average fiber diameter is less than 1 μm, the weight per unit area needs to be increased because of poor self-supporting property. As a result, the pressure loss of the fiber layer 20 becomes large, which is not preferable. On the other hand, if the average fiber diameter exceeds 10 μm, the collection efficiency of the fiber layer 20 is undesirably lowered. Particularly preferred average fiber diameter is 2 to 6 μm.

The fiber diameter of the fiber layer 20 is preferably smaller than the fiber system of the base material layer 19. Thus, the filter medium 15 having high dust collection efficiency, low pressure loss, and good balance can be obtained. The filter medium 15 thus produced has a structure in which the pressure loss is large at the fiber layer 20 and small at the base material layer 19. For example, the pressure loss when air is blown at a flow rate of 5.3cm/s is about 40Pa at the fiber layer 20 and about 3Pa at the base material layer 19.

The base material layer 19 and the fiber layer 20 can be made of a common resin material or a natural fiber material. Examples of the material include Polyacrylonitrile (PAN), polypropylene (PP), Polyethylene (PE), polyethylene oxide (PEO), polyethylene naphthalate (PEN), polyethylene terephthalate (PET), Polyethersulfone (PEs), polymethacrylic acid, polymethylmethacrylate, polyvinylidene fluoride (PVDF), polyvinyl chloride (PVC), polytetrafluoroethylene, polyvinyl alcohol (PVA), Polycarbonate (PC), polystyrene, polyamide, polyimide, polyamideimide, aromatic polyamide, polyimidoindole, polyglycolic acid (PGA), polylactic acid (PLA), Polyurethane (PU), cellulose compounds, polypeptides, and nylon.

The amine compound-containing adsorbent of the present invention contains an amine compound at least in part of the components. Amine compounds are known to undergo irreversible chemical reactions with formaldehyde as follows. For example,

R－NH₂+HCHO

→R－N＝CH₂+H₂o (shiff base)

2H₂NCONH₂(Urea) + HCHO

→NN₂CONHCH₂NHCONH₂(Dimethylol urea)

NH₂－NH₂(hydrazine) +2HCHO

→CH₂＝N－N＝CH₂

And the like. These reactions also occur in gas components having aldehyde groups. Therefore, the amine compound is reactive not only with formaldehyde but also with aldehyde compounds such as acetaldehyde and propionaldehyde. Generally, aldehydes are substances having unpleasant odors, and the filter medium of the present invention can be suitably used for applications of deodorization for aldehydes.

The reaction is called chemisorption because it involves a chemical reaction, and is distinguished from physisorption of activated carbon or the like. In the case of chemical adsorption, there is an advantage that the aldehyde can be stably removed because the adsorbed aldehyde is not released again. On the other hand, amine compounds are basic substances, and have a problem that neutralization reaction occurs when the amine compounds are brought into contact with acidic substances in the air, and the removal performance of aldehydes is lowered. The acidic substance as used herein refers to mist of nitric acid, sulfuric acid, acetic acid, or the like, or floating particles containing these components. In addition, the air contains active components such as ozone, OH radicals, and NO radicals generated by ultraviolet rays. In the conventional air cleaning device, there is a problem that these active ingredients react with the amine compound and the performance is easily deteriorated. Therefore, in the present invention, the active components such as acidic substances and OH radicals are first removed from the air taken into the main body of the air cleaning device 1 by the fiber layer 20 containing the radical trapping agent. Then, aldehydes such as formaldehyde are removed by the adsorbent containing the amine compound contained in the base layer 19. With such a configuration, the filter medium 15 capable of stably maintaining the trapping performance after long-term use and the air cleaning apparatus 1 using the same can be provided.

In the present embodiment, in order to remove active components such as acidic substances and radicals from the fiber layer 20, the fiber layer 20 containing a light stabilizer or an antioxidant as a radical trapping agent is used. As the radical scavenger contained in the fiber layer 20 of the present invention, a general light stabilizer or antioxidant can be used. In particular, hindered amine light stabilizers, hindered phenol antioxidants, benzotriazole light stabilizers, and the like can be used.

Examples of the light stabilizer and the antioxidant which can be used as the radical scavenger of the present invention are mentioned. Examples of commercially available products include TINUVIN 111 (manufactured by BASF JAPAN; 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, polymer of 4-hydroxy-2, 2,6, 6-tetramethyl-1-piperidineethanol (55%)), Uvinul 5050H (manufactured by BASF JAPAN; hindered amine Oligomer (Stericalyhimede Oligomer)), CHIMASSOUND 2020 RB (manufactured by BASF JAPAN; polycondensate of dibutylamine-1, 3, 5-triazine-N, N' -bis (2,2,6, 6-tetramethyl-4-piperidinyl-1, 6-hexamethylenediamine and N- (2,2,6, 6-tetramethyl-4-piperidinyl)), CHIMASSORB944 (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 ] hexamethylene { (2,2,6, 6-tetramethyl-4-piperidyl) imino } ], CYASORB UV-3346 (manufactured by CYTEC; poly [ (6-morpholinyl-s-triazine-2, 4-diyl) [2,2,6, 6-tetramethyl-4-piperidyl ] imino ] -hexamethylene [ (2,2,6, 6-tetramethyl-4-piperidyl) imino ]), CYASORB UV-3529 (manufactured by CYTEC; 1, 6-hexanediamine-N, N' -bis (1,2,2,6, 6-pentamethyl-4-piperidyl) with morpholine-2, 4, 6-trichloro-1, 3, 5-triazine, methylated polymers, Hastavin N30 (manufactured by CLARIANT Co., Ltd.; Polymer of 2,2,4, 4-tetramethyl-7-oxa-3, 20-diaza-20 (2, 3-epoxy-propyl) dispiro- [5,1,11,2] -heneicosane-21-one), vin770 (manufactured by BASF JAPAN Co., Ltd.), Uvinul 4050 (manufactured by BASF JAPAN Co., Ltd.), TINUVIN234 (manufactured by BSAF JAPAN Co., Ltd.; 2- (2H-benzotriazol-2-yl) -4-6-bis (1-methyl-1-phenylethyl) phenol), Uvinul 3030 (manufactured by BASF PAN Co., Ltd.; 1, 3-bis- { [ (2 ' -cyano-3 ', 3-diphenylacryloyl) oxy ] -2, 2-bis- [ (2-cyano-3 ', 3-diphenylacryloyl) oxy ] methyl } propane), TINUVIN (manufactured by BASF JAPAN Co., 326; 2- [ 5-chloro (2H) -benzotriazol-2-yl ] -4-methyl- (5-tert-butyl) phenol), TINUVIN 329(BASF JAPAN; 2- (2H) -benzotriazol-2-yl) -4- (1,1,3, 3-tetramethylbutylphenol, TINUVIN 1577(BASF JAPAN; 2- (4, 6-diphenyl-1, 3, 5-triazin-2-yl) -5- [ (hexyl) oxy ] -phenol), CYASORB UV-531 (CYTEC; 2-hydroxy-4-n-octyloxybenzophenone, IRGANOX 565(BASF JAPAN), IRGANOX1035(BASF JAPAN), etc.

In the present embodiment, in order to remove aldehydes by the base layer 19, the base layer 19 including an adsorbent containing an amine compound is used. As a method for making the substrate layer 19 include an adsorbent containing an amine compound, there is a method in which the adsorbent is dispersed in an aqueous solution, a small amount of a surfactant and a binder are added, and then the substrate layer 19 is impregnated in the aqueous solution. In addition, as other methods, there may be mentioned: a method of spraying the aqueous solution on the substrate layer 19, a method of applying the aqueous solution on the substrate layer 19 with a brush or a roller, or the like. The method of including the radical trapping agent in the fiber layer 20 may also include the following methods: a method of dispersing the radical trapping agent in an organic solvent, adding an ultraviolet additive or the like, and then immersing the fiber layer 20 in the solution, a method of spraying the solution on the fiber layer 20, a method of applying the solution on the fiber layer 20 with a brush or a roller, or the like.

Here, by spraying and drying the aqueous solution from only one surface of the base material layer 19, the adsorbent concentration of the sprayed surface can also be increased. By using the face of the base material layer 19 having a high adsorbent concentration as the face of the base material layer 20 to be bonded, the filter material 15 having a high content of the amine compound on the face of the base material layer 19 to be bonded to the fiber layer 20 and a lower content on the face away from the face to be bonded can be obtained.

When the air cleaner 1 is provided with the air filter 9, the fiber layer 20 and the base material layer 19 are attached in this order from the air inlet 10 side. That is, the air filter 9 includes a fiber layer 20, which is a layer of fibers as a front-stage layer, and a base layer 19, which is a layer of fibers as a rear-stage layer located downstream of the front-stage layer in the air flow.

As a result, the active components such as acidic substances and OH radicals are first removed from the air taken into the main body of the air cleaning device 1 by the fiber layer 20 containing the radical trapping agent. Then, the aldehydes such as formaldehyde are removed by the adsorbent containing the amine compound included in the base material layer 19. With such a configuration, the amine compound contained in the rear layer is less likely to react with active components such as acidic substances and OH radicals in the air. Therefore, the filter medium 15 capable of stably maintaining the trapping performance in long-term use and the air cleaning apparatus 1 using the same can be provided.

(embodiment mode 2)

Next, embodiment 2 will be described with reference to fig. 7. The same components as those in embodiment 1 are denoted by the same reference numerals, and detailed description thereof will be omitted. Fig. 7 is a perspective view of an air filter according to embodiment 2. As shown in fig. 7, the air filter 29 used in the air cleaning device 1 according to the present embodiment includes the base material layer 19, the fiber layer 20, and the frame portion 17, which are processed into a pleated shape, and further includes the prefilter 21.

The prefilter 21 is a layer of nonwoven fabric-like fibers having a fiber diameter and openings necessary for collecting particles such as coarse dust, and is a layer obtained by spray-coating a radical scavenger and then drying it. The prefilter 21 can use a general nonwoven fabric, web, or other fiber having a performance of trapping acidic substances contained in particles in the air, and preferably uses an electrostatic filter capable of trapping particles using an electric force.

The prefilter 21 is bonded to the frame 17 with an adhesive or the like so as not to form a gap therebetween, whereby an air filter 29 integrated with the prefilter 21 can be obtained. Here, if a gap is formed between the prefilter 21 and the frame 17, when the air cleaning device 1 sucks air, the air containing radicals may come into contact with the adsorbent through the gap having a low pressure loss. Therefore, the substrate layer 19 is made to contain at least the adsorbent containing the amine compound in advance, and the fiber layer 20 is made to contain the radical trapping agent in advance.

When the air cleaner 1 is provided with the air filter 29, the prefilter 21, the base material layer 19, and the fiber layer 20 are arranged in this order from the air inlet 10 side. That is, here, the filter medium 15 includes a prefilter 21, a base material layer 19, and a fiber layer 20. The prefilter 21 is a layer containing a radical trapping agent as a front-stage layer and capable of trapping coarse dust fibers. The base material layer 19 is disposed downstream of the prefilter 21 as a rear-stage layer. The fiber layer 20 is disposed downstream of the base material layer 19. The fiber layer 20 is a layer different from the fibers of the prefilter 21, and is a layer of fibers containing a radical trapping agent. That is, the filter medium 15 in embodiment 2 is a member in which the prefilter 21, the base layer 19, and the fiber layer 20 are integrally joined to each other via the frame 17.

As a result, from the air sucked into the main body of the air cleaning device 1, first, the prefilter 21 containing the radical trapping agent removes the active components such as acidic substances and OH radicals, and particles such as coarse dust. After that, aldehydes such as formaldehyde can be removed by the adsorbent containing the amine compound included in the base layer 19. With such a configuration, it is possible to provide a filter medium that stably maintains trapping performance over a long period of use, and an air cleaning apparatus using the filter medium.

In particular, the air filter 29 according to the present embodiment includes the pre-filter 21 as a front stage layer, the base material layer 19 as a rear stage layer, and the fiber layer 20 located on the downstream side of the base material layer 19, and these are integrally joined via the frame portion 17. The prefilter 21 is a layer of fibers that contains a radical trapping agent and is capable of trapping particles. The base layer 19 is a layer of fibers containing a binder containing an amine compound. The fiber layer 20 is a layer different from the fibers of the prefilter 21, and is a layer of fibers containing a radical trapping agent. According to this configuration, since the prefilter 21, the base material layer 19, and the fiber layer 20 are integrally bonded via the frame 17, a part of the air passing through the air filter 29 is not split in a specific layer having a high pressure loss. Therefore, all the air passing through passes through the prefilter 21, the base material layer 19, and the fiber layer 20 in this order. That is, even when the opening of the pre-filter 21 is smaller than the base material layer 19, the air that has surely passed through the pre-filter 21 can be caused to pass through the base material layer 19, and the effect of removing the aldehydes in the base material layer 19 can be more surely exhibited.

Further, when viewed from the base material layer 19 side, the radical trapping agent contained in the prefilter 21 is present on the upstream side, and the radical trapping agent contained in the fiber layer 20 is present on the downstream side. Therefore, the amine compound contained in the base material layer 19 is not directly exposed to active components such as acidic substances and OH radicals on the upstream side, nor is it directly exposed to these components on the downstream side. With this configuration, even when the air cleaning device 1 is stopped, the performance of the adsorbent contained in the base material layer 19 is not easily deteriorated, and the effect of stably maintaining the trapping performance in long-term use can be obtained.

The prefilter 21, i.e., the layer of fibers capable of trapping particles, which is the front-stage layer, may be the same as the fiber layer 20, or may be a material having openings larger than those of the fiber layer 20 in the filter material.

Industrial applicability

The filter medium according to the present invention includes a base material layer containing an adsorbent containing an amine compound, and a fiber layer capable of trapping particles, the fiber layer containing a radical trapping agent, and the filter medium is in the form of a sheet in which the base material layer and the fiber layer are bonded to each other. This makes it possible to effectively remove chemical substances such as formaldehyde, stably maintain the effect over a long period of use, and be applied to ventilators and the like that require the same function.

Description of the symbols

1. 100 air cleaning device

2 indoors

3 floor

4 wallpaper

5 furniture

6 window

7 main body outer casing

8 blast part

9. 29 air filter

10 air inlet

11 exhaust port

12 casing

13 blade

14 motor

15. 150 filter material

16 shape holding part

17 frame part

18 joining member

19 base material layer

20 fiber layer

21 prefilter

101 air filter

102 frame body

103 blower

104 air inlet grille

105 main body

Claims

1. A filter material, comprising: a front layer; and a rear-stage layer located on a downstream side of the airflow with respect to the front-stage layer, wherein the filter medium is formed in a sheet shape in which the front-stage layer and the rear-stage layer are closely bonded to each other, and the filter medium is characterized in that:

the front layer is a layer of fibers containing a radical trapping agent and capable of trapping particles,

the back layer is a layer containing fibers of an adsorbent containing an amine compound.

2. The filter filtration material of claim 1, wherein:

the amine compound is applied to the surface of the fibers constituting the rear layer.

3. The filter filtration material of claim 1, wherein:

the radical trapping agent contains at least one of hindered amines, hindered phenols, and benzotriazoles.

4. The filter filtration material of claim 1, wherein:

the amine compound content in the rear layer is higher on the side of the bonding surface with the front layer, and is lower as the distance from the bonding surface increases.

5. An air cleaning device, comprising:

a main body housing having an air suction port and an air discharge port;

a blower disposed within the main body housing; and

an air filter disposed between a suction side of the blower and the suction port,

the air filter includes the filter material of claim 1.

6. An air cleaning device as claimed in claim 5, wherein:

the air filter has:

a prefilter as said front stage layer;

a substrate layer as the back layer; and

a fiber layer arranged on the downstream side of the base material layer and different from the former layer, the fiber layer containing a radical trapping agent; and

the frame part is provided with a plurality of frame parts,

the prefilter, the base layer, and the layer of fibers different from the front-stage layer are all integrally joined via the frame portion, and are disposed on the intake port side of the main body casing.