JP2018034082A - Filter medium and air cleaner using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a filter medium which effectively removes chemical substances such as formaldehyde, and can maintain effect stably for a long period of time, and provide an air cleaner using the same.SOLUTION: A filter medium includes a base material layer, and a fiber layer which can collect particles. The base material layer includes absorbent containing an amine compound. The fiber layer contains an aromatic amine compound. Formaldehyde can be stably collected for a long period of time by the sheet-like filter medium formed by the base material layer and the fiber layer closely adhering to each other. In addition, an air cleaner provided with the filter medium can be 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.

  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.

  Conventionally, this type of filter medium has the following configuration in order to prevent the adsorbent held on the filter medium from dropping and to suppress a decrease in the adsorption function. That is, as shown in FIG. 7, the air filter 101 was a fiber laminate composed of at least two layers of fiber structures of a base fabric layer 102 and a surface layer 103. More specifically, in the air filter 101, the base fabric layer 102 is made of fibers having an average fiber diameter of 10 μm or more in which activated carbon is held inside as an adsorbent for removing malodors and harmful gases, and the surface layer 103 is made of an average fiber It was a fiber laminate composed of fibers having a diameter of 10 to 1000 nm. Thus, it has been disclosed that the contact efficiency with air can be improved without increasing the pressure loss by making the average fiber diameters of the base fabric layer 102 and the surface layer 103 different. In this case, the surface layer 103 is preferably laminated on the base fabric layer 102 to form a fiber structure such as a fiber web, and a method of uniformly laminating by electrospinning has been disclosed (for example, see Patent Document 1). ).

  In addition, in order to obtain a resin composition made into a fiber by an electrospinning method, as a charge stabilizer, hindered amine, nitrogen-containing hindered phenol, metal salt hindered phenol, phenol, hindered phenol, phenol There has been known a method of using at least one selected from the group consisting of a sulfur-based weather resistance imparting agent and a fatty acid metal salt. This nonwoven fabric was able to improve the filter performance of resin fibers as a filter medium for an air cleaning device (see, for example, Patent Document 2).

JP 2009-190269 A JP 2008-221074 A

  In such a conventional filter medium and an air purifying apparatus using the same, it is possible to remove formaldehyde with a low pressure loss and to prevent the adsorbent from falling off. It has been desired to further maintain the removal performance.

  Then, when the use of an amine compound for removing formaldehyde was studied, the following problems were found. That is, an amine compound is a basic substance, and when it comes into contact with an acidic substance contained in air particles, it causes a neutralization reaction, resulting in a decrease in performance. 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. It means that the performance is easily deteriorated by reacting with an amine compound.

  In addition, in the conventional charge stabilizer, no mention is made of the antagonistic action when various additives are used. When various additives are used in combination, performance may be reduced due to their poor compatibility, and it is necessary to avoid increasing the types of additives used.

  SUMMARY OF THE INVENTION The present invention solves the above-described conventional problems, and an object thereof is to provide a filter medium that can stably maintain the effect of removing chemical substances such as formaldehyde for a long period of time, and an air purifier using the filter medium.

  In order to achieve this object, the present invention provides a filter medium having a base material layer and a fiber layer capable of collecting particles on the upstream side of the base material layer, wherein the base material layer is an amine. A filter medium in the form of a sheet containing an adsorbent containing an organic compound, an aromatic amine compound in the fiber layer, and the base material layer and the fiber layer being in close contact with each other, and an air cleaning device using the same. This achieves the intended purpose.

  According to the present invention, there is provided a filter medium including a fiber layer and a base material layer provided on the downstream side of the airflow with respect to the fiber layer, the fiber layer including an aromatic amine compound and collecting particles. It is a possible fiber layer, and the base material layer is a fiber layer containing an adsorbent containing an amine compound, and the fiber layer and the base material layer are formed into a sheet-like shape. Further, it is possible to provide a filter medium capable of stably maintaining the effect of removing chemical substances such as formaldehyde for a long period of time and an air purifying apparatus 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 A perspective view showing a conventional air cleaning device

  The filter medium according to claim 1 of the present invention is a filter medium having a base material layer and a fiber layer capable of collecting particles upstream of the base material layer, wherein the base material layer is an amine compound. The fiber layer contains an aromatic amine compound, and the base material layer and the fiber layer are in close contact with each other.

  Thereby, after the acidic substance particles in the air are collected in the fiber layer in the air sucked by the air cleaner, formaldehyde in the air comes into contact with the adsorbent in the base material layer. In this case, it is possible to obtain an effect that the effect can be stably maintained for a long period of time without causing the neutral amine reaction to deteriorate the performance. Furthermore, 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 aromatic amine compound contained in the fiber layer. The performance deterioration of the amine compound contained in the layer is suppressed, and the 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 a fiber constituting the base material layer.

  As a result, the applied amine compound is contained over a wide range of fibers constituting the base material layer, so the contact distribution with the passing formaldehyde is made uniform and the chemical removal effect is further improved. It can be done.

  In the filter medium according to claim 3, the content of the amine-based compound in the base material layer is high on the side of the close contact surface with the fiber 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 away from the adhesion surface, and the ratio of the amine compound reacting with the air when storing the filter medium is reduced. Can be reduced. Therefore, compared with the case where it apply | coats uniformly, the ratio which an amine compound remains can be kept high, and initial stage performance can be maintained over a long period of time.

  In the filter medium according to claim 4, the aromatic amine compound of the fiber layer is a primary amine.

  Thereby, in addition to the active component removal effect | action of an aromatic amine compound, a primary amine can also expect a formaldehyde adsorption effect similarly to an amine compound, and can strengthen the adsorption effect as a filter medium.

  The filter medium according to claim 5 is an electrospun nonwoven fabric in which the volume resistivity of the polymer forming the fiber layer is 1016 Ωcm or more and the dielectric loss tangent is 0.001 or less. .

  Thereby, the collection performance of particles in the fiber layer can be improved by the chargeability of the polymer charged during electrospinning, and the performance deterioration due to the acidic substance of the amine compound in the substrate layer can be suppressed.

    The filter medium according to claim 6 is a nonwoven fabric in which the side chain of the polymer forming the fiber layer has a nonpolar group.

  Thereby, the compatibility between the side chain of the polymer and the aromatic ring of the aromatic amine compound is improved, and the aromatic amine compound can be present in a wide range and uniformly without aggregation in the fiber of the polymer. Furthermore, the amino group, which is a polar group of the aromatic amine compound, can be positioned with directivity on the fiber surface (on the side of the fiber-air interface) while avoiding a nonpolar region in the fiber. Since the uniformly oriented polar group (amino group) improves the chargeability, the effect of improving the chargeability of the fiber layer can be further enhanced.

  An air cleaning device according to claim 7 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, the air purifier which can maintain the effect which removes chemical substances, such as indoor formaldehyde, stably for a long term can be provided.

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 the air. Also, when a person moves, outdoor air flows in by opening and closing the window 6, and active substance particles such as ozone, OH radicals, and NO radicals generated by the action of outdoor ultraviolet rays enter the room. is there. In this way, the air in the room 2 is in a state in which, in addition to formaldehyde, acidic substance particles or active components such as ozone, OH radicals, and NO radicals are included.

  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, and the front surface of the main body case 7 is provided with a substantially square-shaped air inlet 10 that surrounds the center panel at the edge portion. A rectangular exhaust port 11 is provided.

  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 inside 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 unit 16 includes a square-shaped frame portion 17 and an adhesive member 18 provided between the frame portion 17 and the filter medium 15. That is, the frame part 17 is located at the periphery of the filter medium 15, and the adhesive member 18 fixes the filter medium 15 and the pleated shape of the filter medium 15 to the frame part 17.

  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 including at least one of glass fibers, pulp fibers, resin fibers, carbon fibers, and inorganic fibers.

  Examples of the method for producing the base material layer 19 include a spunbond method, a dry or wet papermaking method, a melt blown method, a spunbond method, an airlaid method, and a thermal bond method.

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 is lowered, 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 average fiber diameter of the fibers constituting the fiber layer 20 is preferably as narrow as possible because a low-pressure loss can be achieved in principle when the fibers are charged. In general, it is preferably composed of fibers of 50 nm to 1500 nm. When the fiber diameter is thicker than 1500 nm, the ratio of the resin fiber volume when forming the pores of the fiber layer 20 increases, and the air resistance increases (increases the pressure loss), which is not preferable. A fiber diameter smaller than 50 nm is not preferable because fiber breakage and fluffing are likely to occur. More preferably, the fiber diameter is 100 nm or more and 200 nm or less.

  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 thus prepared has a pressure loss that is larger 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 fiber layer 20, a general resin material or a natural fiber material can be used. For example, polyacrylonitrile (PAN), polypropylene (PP), polyethylene (PE), polystyrene (PS), polyethylene oxide (PEO), polyphenyl ether (PPE), polyphenylene oxide (PPO), polytetrafluoroethylene (PTFE), Polyethylene naphthalate (PEN), polyethylene terephthalate (PET), polyethersulfone (PES), polymethacrylic acid, polymethyl methacrylate, polyvinylidene fluoride (FVDF), polyvinyl chloride (PVC), polytetrafluoroethylene, polyvinyl alcohol (PVA), polycarbonate (PC), polystyrene, polyamide, polyimide, polyamideimide, aramid, polyimide benzazole, polyglycolic acid (PGA), polymilk (PLA), polyurethane (PU), cellulose compound, a polypeptide, such as nylon, or the like things like mixtures thereof.

  The adsorbent contained in the base material layer 19 contains an amine compound as at least a part of the components. As a means for including the adsorbent containing the amine compound in the base material layer 19, the adsorbent is used as a spinning solution or a coating solution at the time of fiber spinning of the base material layer 19 or coating of the resin on the base fiber. A method of containing the solution, a method of dissolving and dispersing the adsorbent in an aqueous solution, adding a small amount of a surfactant and a binder, and then immersing the base material layer in the adsorbent solution, a method of spraying the adsorbent solution, The method of apply | coating aqueous solution with a brush or a roller etc. are mentioned. 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.

  The air contains active components such as ozone, OH radicals, and NO radicals generated by ultraviolet rays. In the air cleaning apparatus 1 that performs processing by sucking a large amount of air, these active components are used. However, there is a problem in that the reaction with the amine compound tends to deteriorate the performance. Therefore, in this Embodiment, after removing active substances, 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 an aromatic amine compound, the base material layer 19 It provides a filter medium that removes aldehydes such as formaldehyde with an adsorbent containing amine compounds contained in, and maintains the collection performance stably for a long period of time, and an air purifier using the same. is there.

  An example which can be applied as the aromatic amine compound of the present embodiment will be given. For example, aniline, N-methylaniline, N, N'-dimethylaniline, aminobenzoic acid, methylaminebenzoic acid, dimethylaminebenzoic acid, aminophenol, methylaminephenol, dimethylaminephenol, diaminobenzene, N-methyldiaminobenzene N, N′-diaminobenzene, methyldiaminobenzene and the like. The means for including the aromatic amine compound in the fiber layer 20 includes dispersing the aromatic amine compound in water or an organic solvent, immersing the fiber layer 20 in the dispersion, spraying the dispersion, and dispersing the dispersion. Examples thereof include a method of applying with a brush or a roller. Further, the aromatic amine compound can be mixed into the polymer liquid during fiber spinning.

  In the means for including the adsorbent containing the amine compound in the base material layer 19, by using a technique of impregnating or applying the adsorbent liquid after forming the fiber of the base material layer 19, the adsorbent is spread over the entire fiber surface. It will be in a state of being contained over. For this reason, the distribution of contact between the formaldehyde passing through the base material layer 19 and the amine compound contained in the fibers of the base material layer 19 becomes uniform, and the effect of removing formaldehyde can be further improved.

  Moreover, the adsorbent density | concentration of the sprayed surface can be raised by using the method of spraying and drying an adsorbent liquid only from the single side | surface of the base material layer 19. FIG. By making the surface of the base material layer 19 having a high adsorbent concentration a close contact surface with the fiber layer 20, the content of the amine compound on the close contact surface of the base material layer 19 and the fiber layer 20 is high, and the farther away from the close contact surface. A filter medium having a reduced content can be obtained. Therefore, there is only a small amount of amine compound on the surface exposed to air away from the close contact surface, and the rate at which the amine compound reacts on contact with air during storage of the filter media decreases. Can be made. That is, compared with the case where it apply | coats uniformly, the ratio which an amine compound remains can be kept high, and initial stage performance can be maintained over a long period of time.

  In addition, the adsorbent density | concentration gradient formation method to the thickness direction of the base material layer 19 by the said spray application is the fiber (containing means (immersion, spray, brush, roller) which once contained adsorbent) containing the adsorbent once. Even if it is the base material layer 19 formed in (There is no restriction | limiting), an effect is acquired. In this case, in addition to increasing the amount of adsorbent adhering to the base material layer 19, the adsorbent content on the adhesion surface of the base material layer 19 and the fiber layer 20 is increased. Can do. Thereby, at the time of storage of a filter medium, the ratio by which an amine compound reacts by contact with air and decreases can be reduced.

  When the primary amine is used as the aromatic amine compound contained in the fiber layer 20, the primary amine itself has an effect of adsorbing formaldehyde, and in addition, it is acidic from the air sucked into the main body of the air cleaning device 1. The effect of protecting the amine compound of the adsorbent contained in the substrate by removing the substance and the active ingredient can be obtained. Further, the primary amine adsorbing formaldehyde is finally changed into a secondary amine and a tertiary amine. Thereby, the radical scavenging effect is increased and the action of protecting the adsorbent amine compound of the base material layer 19 is enhanced. That is, by starting the use of the filter and the air purifying apparatus 1 using the filter, it is possible to enhance the scavenging effect of oxidizing substances and active components and protect the adsorbent amine compound even in the aromatic amine compound treated with formaldehyde. it can. This suppresses the reactivity of the aromatic amine compound until the start of use of the air cleaning device, and can enhance the reactivity to the oxidizing substance and the active component by performing formaldehyde adsorption when the use of the air cleaning device is started. An example which can be applied as the primary aromatic amine compound of the present invention will be given. For example, aniline, aminobenzoic acid, aminophenol, diaminobenzene, methyldiaminobenzene and the like.

  When the polymer species forming the fiber layer 20 is an electrospun fiber having a volume resistivity of 1016 Ωcm or more and a dielectric loss tangent of 0.001 or less, the aromatic amine compound is incorporated into the polymer solution during fiber spinning. By mixing it, electrospinning can be performed in a state where the aromatic amine compound is contained in the spun fiber. For this reason, the electrification property of the fiber polymer is improved by the property of being easily charged as the selected polymer property and the polar group (amino group) of the aromatic amine compound in the chargeable polymer. Dust performance can be improved. Therefore, the dust collection performance as a filter medium is improved. That is, it is possible to improve the dust collection performance by including at least one aromatic amine compound in the fiber layer 20 as an additive, and to prevent the performance of the adsorbent contained in the base material layer 19 from being lowered. It becomes. Since this can reduce the additive species used for the fiber layer 20, it also has an effect of suppressing the antagonistic action on the charging property that occurs when a plurality of types of additives for the fiber layer 20 are used. Examples of polymers having this effect include polyethylene (PE), polystyrene (PS), polypropylene (PP), polyphenyl ether (PPE), polyphenylene oxide (PPO), polytetrafluoroethylene (PTFE), and polyphenylsulfone (PPSU). Perfluoroalkoxyalkane (PFA), tetrafluoroethylene-hexafluoropropylene copolymer resin (FEP), tetrafluoroethylene-ethylene copolymer resin (ETFE), or a mixture thereof.

  Further, the side chain of the polymer species forming the fiber layer 20 is preferably made of only carbon or hydrogen and having high hydrophobicity. Examples thereof include polystyrene, polypropylene, polyphenyl ether, polyphenylene oxide and the like.

  Thereby, the compatibility between the side chain of the polymer and the aromatic ring of the aromatic amine compound is improved, and the aromatic amine compound can be present in a wide range and uniformly without aggregation in the fiber of the polymer. Furthermore, the amino group, which is a polar group of the aromatic amine compound, can be positioned with directivity on the fiber surface (on the side of the fiber-air interface) while avoiding a nonpolar region in the fiber. Since the uniformly oriented polar group (amino group) improves the chargeability, the effect of improving the chargeability of the fiber layer can be further enhanced.

  More preferably, the polymer resin species forming the fiber layer 20 has an aromatic ring in the side chain such as polystyrene. As a result, the π electrons in the aromatic ring of the polymer and the aromatic amine compound form a stacking bond, so that further improvement in compatibility can be expected.

  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 20 that is a front layer and a base material layer 19 that is a rear layer provided on the downstream side of the airflow with respect to the front layer. Thereby, 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 compound contained in the base material is removed. It becomes the structure which removes aldehydes, such as formaldehyde, with the adsorbent to contain, and can provide the filter medium which maintains the collection performance stably for a long period of time, and the air purifier using the same.

  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 an aromatic amine compound agent, and the base material layer and the fiber layer are in the form of a sheet that has a long-term stable effect of effectively removing chemical substances such as formaldehyde. And can be applied to a ventilator that requires the same function.

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 101 Air filter 102 Base fabric layer 103 Surface layer

Claims (7)

A filter medium having a base material layer and a fiber layer capable of collecting particles on the upstream side of the base material, wherein the base material layer includes an adsorbent containing an amine compound, and the fiber layer includes A filter medium comprising an aromatic amine compound, wherein the base material layer and the fiber 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 base material layer. 3. The filter medium according to claim 1, wherein the content of the amine compound in the base material layer is high on a close contact surface side with the fiber layer and decreases as the distance from the close contact surface increases. The filter medium according to any one of claims 1 to 3, wherein the aromatic amine compound of the fiber layer is a primary amine. The volume resistivity of the polymer forming the fiber layer is 1016 Ωcm or more and the dielectric loss tangent is 0.001 or less, and the nonwoven fabric is an electrospun nonwoven fabric according to any one of claims 1 to 4. Filter media. The filter medium according to any one of claims 1 to 5, wherein the side chain of the polymer forming the fiber layer has a nonpolar group. 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: 6. An air purifier comprising the filter medium according to any one of 6 above.