JP6290891B2 - Air cleaner - Google Patents

Description

  The present invention relates to an air purifier using an electric dust collecting filter in which a functional group having deodorizing properties is introduced on the surface of a fiber, and further, metal ions having bactericidal and antiviral properties are bonded to the functional group. is there.

  In recent years, deaths due to viral infections such as SARS (Severe Acute Respiratory Syndrome), Norovirus and avian influenza have been reported. Furthermore, health damage caused by air pollutants such as PM2.5 has become a problem, and there is a need for an air purifier with functions such as sterilization, antiviral properties, and deodorization as well as dust removal. It has been.

  In order to deal with such a situation, the dust that has passed between the charged wires is collected by the dust collecting unit carrying the photocatalyst and then irradiated with UV to inactivate bacteria and viruses. A cleaner, (Patent Document 1), and a functional filter (Patent Document 2) that can adsorb and remove gas components such as ammonia by introducing ion exchange groups onto the fiber surface by radiation graft polymerization have been developed.

JP 2001-79077 A JP-A-6-142439

  However, when bacteria and viruses are inactivated with a photocatalyst as in Patent Document 1, an ultraviolet irradiation unit is required, so that the apparatus becomes large, and the filter and the apparatus are deteriorated depending on the material constituting them. There's a problem. Furthermore, it takes time to inactivate bacteria and viruses with photocatalysts. Further, as disclosed in Patent Document 2, only relatively coarse particles can be removed with a filter made of ion-exchange fibers as in Patent Document 2, so that a high-performance filter in the latter stage is used for small dust such as viruses and bacteria. If it is not used together, removal is difficult. When a high performance filter is used, the pressure loss becomes high.

  Therefore, in order to solve the above problems, the present invention has a higher collection efficiency even with a structure having a low pressure loss, and further has a deodorizing function and an inactivation function of bacteria and viruses collected by a filter. It aims at providing the air cleaner which combines.

  That is, the first invention is a discharge electrode to which a voltage is applied, a ground electrode disposed opposite to the discharge electrode, and a fiber structure disposed between the discharge electrode and the ground electrode and having air permeability. A dust collection filter formed by a body, which binds to a functional group having a deodorizing property introduced into at least a part of fibers of the fiber structure and a part of functional groups of the introduced functional group An air cleaner comprising a dust collection filter having metal ions, and having both an inactivation function and a deodorization function of bacteria and / or viruses collected by the dust collection filter.

  According to a second invention, in the first invention, the metal ions are selected from at least one of copper, silver, zinc, gold, platinum, cobalt, nickel, tin, aluminum, and palladium. It is a purifier.

  Still further, a third invention is characterized in that, in the first or second invention, the deodorizing functional group introduced into the dust collecting filter is introduced by an electron beam graft polymerization method. It is a purifier.

  Furthermore, in a fourth invention according to any one of the first to third inventions, the deodorizing functional group introduced into the dust collecting filter is at least from a sulfonic acid group, a phosphoric acid group, and a carboxyl group. An air cleaner characterized in that it is an acidic functional group having a basic gas adsorption ability selected from one kind.

  Furthermore, a fifth invention is the basic of any one of the first to third inventions, wherein the functional group having a deodorizing property introduced into the dust collecting filter is an amino group and has an acid gas adsorption ability. It is an air cleaner characterized by being a functional group.

  Furthermore, a sixth invention is the method according to any one of the first to third inventions, wherein the functional group having a deodorizing property introduced into the dust collecting filter is at least from a sulfonic acid group, a phosphoric acid group, and a carboxyl group. An air cleaner characterized in that it is a basic functional group having an acidic gas adsorption ability comprising an acidic functional group and an amino group having one basic gas adsorption ability.

  Furthermore, a seventh invention is characterized in that, in any one of the first to seventh inventions, the dust collection filter contains inorganic fine particles having acidic gas adsorption characteristics and / or basic gas adsorption characteristics. It is an air purifier.

  According to the present invention, there is provided an air purifier having a higher collection efficiency even in a structure with low pressure loss, and further having a deodorizing property and a function of inactivating bacteria and viruses collected by a filter. Can be provided.

It is a schematic diagram of the air cleaner of this embodiment. It is a schematic diagram of the air cleaner of other embodiment. It is a schematic diagram of the air cleaner of other embodiment.

  Hereinafter, embodiments of the present invention will be described in detail with reference to FIGS.

  1 and 2 are schematic views of the air cleaner 100 of the present embodiment. The air cleaner 100 of the present embodiment is an electric dust collection type air cleaner that charges and collects minute substances such as dust containing bacteria and viruses. The air cleaner 100 according to the present embodiment includes a suction unit that sucks air, a dust collection unit A that collects and inactivates dust containing bacteria and viruses, a fan 50 as a blowing unit, and a discharge unit. . The dust collection part A has a discharge electrode 20, a ground electrode 30, a dust collection filter 10, and a power supply 40, and the dust collection filter 10 is sandwiched between the discharge electrode 20 and the ground electrode 30. Yes. In some cases, a prefilter for removing relatively large dust such as hair and lint may be provided between the discharge electrode 20 and the suction portion. In FIG. 1, the suction portion may be a portion described as the inlet side, or may be provided further upstream by connecting a duct or the like. Moreover, the discharge part is the same, and the part described as the exit side in FIG. 1 may be sufficient, and it may be provided further downstream. Further, in FIG. 1, the casing in which the discharge electrode 20 and the like are arranged and forms a space for collecting dust is described transparently so that the internal configuration can be understood. Further, in FIG. 1, the discharge electrode 20, the dust collection filter 10, and the ground electrode 30 are arranged apart from each other, but actually the dust collection filter 10 is connected to the discharge electrode 20 and the ground electrode 30. The electric field described later is more likely to occur when the dust collection filter 10 is sandwiched (clamped) in contact with the discharge electrode 20 and the ground electrode 30 because the dust collection filter 10 is disposed between the discharge electrode 20 and the ground electrode 30. The dust collection filter 10 is preferable because it is easily electretized.

  The air cleaner 100 of this embodiment takes in air from a suction part by operation | movement of the fan 50 etc., and the taken-in air is sent in in a main body. The discharge electrode 20 and the ground electrode 30 extend in a direction perpendicular to the air flow direction and are arranged in parallel to each other. A dust collection filter 10 is installed downstream of the discharge electrode 20 in the ventilation direction, and a ground electrode 30 is installed downstream of the ventilation direction.

  The dust collection part A adsorbs minute substances such as bacteria, viruses, and dust (hereinafter, “dust” in this embodiment includes those containing bacteria and viruses in addition to dust and dust). In addition, it can inactivate bacteria and viruses, and can adsorb and deodorize gases that cause odors.

  Specifically, an electric field is generated between the discharge electrode 20 and the ground electrode 30 by first applying a voltage to the discharge electrode 20 by the power source 40 (high voltage power source). By installing the dust collection filter 10 between the electrodes in which the electric field is generated, the fibers constituting the dust collection filter 10 are polarized and electretized, so that the passing dust is electrostatically adsorbed and collected. Note that the polarity of the DC high voltage applied from the high-voltage power supply 40 may be positive or negative.

  As will be described later, since metal ions are fixed on the surface of the dust collection filter 10, bacteria and viruses collected by the dust collection filter 10 are inactivated by the action of the metal ions. Further, since a functional group having a deodorizing property (hereinafter referred to as a “deodorizing functional group”) is introduced on the surface of the dust collection filter 10, it exists in the air sucked and introduced into the dust collecting part A. Malodorous components such as ammonia gas are adsorbed on the functional group and deodorized.

  As described above, since the dust collection filter 10 of the present embodiment is charged, even if it is not a small opening such as a HEPA filter, it is electrically collected even if it is very small such as bacteria or viruses. can do. In addition, in the dust collection part A of the said structure (the discharge electrode 20, the ground electrode 30, and the dust collection filter 10), at least the dust collection filter 10 may be pleated. Since the filter area is increased by the pleating process, the surface wind speed of the dust collecting portion is reduced, the dust collecting performance is improved, and the deodorizing property can be improved.

  The virus that can be inactivated in the dust collection filter 10 used in the air cleaner 100 of the present embodiment is not particularly limited, and it is possible to inactivate various viruses regardless of the type of genome or the presence or absence of an envelope. Can do. For example, rhinovirus, poliovirus, foot-and-mouth disease virus, rotavirus, norovirus, enterovirus, hepatovirus, astrovirus, sapovirus, hepatitis E virus, type A, type B, type C influenza virus, parainfluenza virus, mumps virus (mumps) ) · Measles virus · Human metapneumo virus · RS virus · Nipah virus · Hendra virus · Yellow fever virus · Dengue virus · Japanese encephalitis virus · West Nile virus · Type B, hepatitis C virus · Eastern and western equine encephalitis virus · Onion Nyon virus, rubella virus, Lassa virus, Funin virus, Machupo virus, Guanarito virus, Sabia virus, Crimea congo hemorrhagic fever virus, snubber fever, hantavirus, shin Umbre virus, rabies virus, ebola virus, marburg virus, bat lyssa virus, human T cell leukemia virus, human immunodeficiency virus, human coronavirus, SARS coronavirus, human porvovirus, polyomavirus, human papillomavirus, adenovirus Examples include herpes virus, varicella-zoster rash virus, EB virus, cytomegalovirus, smallpox virus, monkeypox virus, cowpox virus, molasipox virus, and parapox virus.

  Moreover, about the bacteria which can be inactivated in the dust collection filter 10 used for the air cleaner 100 of this embodiment, it can sterilize irrespective of Gram positive or negative. Examples thereof include Escherichia coli, Staphylococcus aureus, Staphylococcus aureus, Pseudomonas aeruginosa, and Klebsiella pneumoniae.

  The discharge electrode 20 used in the air cleaner 100 of the present embodiment is not particularly limited as long as it has air permeability and conductivity, but as an example, a mesh or nonwoven fabric formed from a metal wire or metal fiber, a wire , Lattice-like, saddle-like or protruding metal plates, punched metal plates and sheets, steel wool, expanded mesh, synthetic fiber knitted fabrics (including non-woven fabrics) coated with conductive materials such as plating It is done. In addition, as shown in FIG. 2, the discharge electrode 20 may be an electrode having a plurality of sharp edge portions like a saw blade like a needle electrode. By making the shape like a needle-like electrode, streamer discharge is generated and the gas that could not be adsorbed is decomposed, so that further deodorizing performance can be imparted.

  As in the case of the discharge electrode 20, the ground electrode 30 is not particularly limited in structure or material as long as it has air permeability and conductivity. However, for the purpose of generating an electric field uniformly on the entire surface of the dust collection filter 10, a metal mesh or an expanded electrode is used. A flat woven or knitted fabric (including non-woven fabric) coated with a conductive material by mesh, plating or the like is preferable.

  The dust collection filter 10 is a filter that is charged by the electric field formed by the ground electrode 30 and the discharge electrode 20 as described above and electrostatically adsorbs and collects dust. The dust collection filter 10 used in the air cleaner 100 of the present embodiment includes a fiber structure having air permeability, a deodorant functional group having a deodorizing property present on the surface of the fiber structure, and an ion bond with the functional group. And having fixed metal ions.

  As a material constituting the fiber structure, the fiber forming the fiber structure may be a fiber composed of a polymer or a fiber in which at least a part of the surface is a polymer. Specific examples include various resins, synthetic fibers, natural fibers such as cotton, hemp, and silk, and Japanese paper obtained from natural fibers.

  More specifically, polyethylene resin, polypropylene resin, polystyrene resin, ABS resin, AS resin, EVA resin, polymethylpentene resin, polyvinyl chloride resin, polyvinylidene chloride resin, polymethyl acrylate resin, polyvinyl acetate resin, Polyamide resin, polyimide resin, polycarbonate resin, polyethylene terephthalate resin, polybutylene terephthalate resin, polyacetal resin, polyarylate resin, polysulfone resin, polyvinylidene fluoride resin, Vectran (registered trademark), PTFE (polytetrafluoroethylene) and other thermoplastic resins, poly Lactic acid resin, polyhydroxybutyrate resin, modified starch resin, polycaprolacto resin, polybutylene succinate resin, polybutylene adipate terephthalate resin, polybutylene sac Biodegradable resins such as nitrate terephthalate resin and polyethylene succinate resin, phenol resin, urea resin, melamine resin, unsaturated polyester resin, diallyl phthalate resin, epoxy resin, epoxy acrylate resin, silicon resin, acrylic urethane resin, urethane resin, etc. And thermosetting resins, silicone resins, polystyrene elastomers, polyethylene elastomers, polypropylene elastomers, polyurethane elastomers, and other natural resins such as lacquer.

  The dust collection filter 10 of this embodiment is demonstrated more concretely. As an example of the fiber structure related to the dust collection filter 10, a sheet-like woven fabric, knitted fabric, non-woven fabric, or the like can be used. Moreover, collection efficiency can be raised more by making it into a pleat shape as shown in FIGS. A laminate of a woven fabric, a knitted fabric, or a nonwoven fabric may be used.

  Next, the deodorant functional group which the dust collection filter 10 has is demonstrated. The dust collection filter 10 includes a deodorizing functional group on at least a part of the fibers constituting the fiber structure. More specifically, at least a part of the fiber surface of the fiber of the fiber structure is provided with a deodorizing functional group having a deodorizing property. These deodorant functional groups are not particularly limited as long as they have ion exchange ability, but sulfonic acid groups, amino groups, phosphoric acid groups, carboxyl groups and the like are preferably used. These deodorant functional groups are roughly classified into two types: acidic functional groups that adsorb basic gas and basic functional groups that adsorb acidic gas. Examples of acidic functional groups that adsorb basic gas include sulfonic acid groups, phosphoric acid groups, and carboxyl groups. Examples of basic functional groups that adsorb acidic gas include amino groups.

  Examples of a method for introducing these deodorant functional groups into a fiber structure (base material) containing a polymer include a method of bringing a substance containing a deodorant functional group to be introduced into contact with the base material. For example, in the case of introducing a sulfonic acid group, it is brought into contact with sulfuric anhydride, concentrated sulfuric acid, chlorosulfonic acid, fuming sulfuric acid, sulfur trioxide, sulfamic acid, sodium sulfite, sodium bisulfite, or a combination thereof. In particular, fuming sulfuric acid, sodium sulfite and the like are preferably used. As for the contact method, a known method such as dipping or coating is used for the aqueous solution. However, for a material that is easily vaporized such as sulfuric anhydride, a method of bringing the vaporized gas into contact with the substrate can also be used.

  Further, as another method for introducing a deodorant functional group into a fiber structure, for example, as a monomer having a deodorant functional group, acrylic acid, methacrylic acid, sodium styrenesulfonate, sodium methallylsulfonate, allylsulfone By performing radiation graft polymerization using sodium acid, vinylbenzyltrimethylammonium chloride or the like, a deodorant functional group can be directly introduced into the fiber structure.

  Another method by radiation graft polymerization is to introduce a deodorant functional group into the graft chain by introducing a deodorizing functional group into the graft chain after introducing a graft chain by radiation graft polymerization. A functional group may be introduced. In this case, examples of the monomer used for graft polymerization include acrylonitrile, acrolein, vinylpyridine, styrene, chloromethylstyrene, and glycidyl methacrylate. For example, glycidyl methacrylate is introduced into a fiber structure (for example, a nonwoven fabric substrate) by radiation grafting, and then a sulfonating agent such as sodium sulfite is reacted to introduce a sulfonic acid group, thereby eliminating the basic gas. A fiber having odor properties can be obtained. In addition, a basic functional group capable of deodorizing acidic gases such as quaternary ammonium and tertiary amino groups can be introduced through glycidyl methacrylate with diethanolamine or the like.

  In addition, before contacting the fiber structure which comprises the dust collection filter 10 of this embodiment, and the substance containing a deodorant functional group, ie, as a pre-process of a deodorant functional group introduction process, (alpha), (gamma), Radicals may be generated in the polymer portion of the substrate surface by radiation such as β rays, electron beam, ultraviolet rays, corona discharge, plasma irradiation, or the like. By generating radicals, the deodorant functional group and the radical are chemically bonded, and the deodorant functional group can be easily introduced while suppressing the deterioration of the resin, which is difficult to introduce the deodorant functional group, and more robust. There are merits such that the deodorant functional group can be fixed to the surface, or the deodorant functional group can be introduced only into the portion where the deodorant functional group is desired to be introduced.

  At this time, the material that can be used as the fiber structure constituting the dust collection filter 10 of the present embodiment is not limited as long as it is the resin described above, but polyethylene, polypropylene, polystyrene, polycarbonate, polyester, polyamide, polyacetal, Examples include polyvinyl chloride, polyvinylidene chloride, polyvinylidene fluoride, polyacrylic acid, polymethyl methacrylate, polyurethane, ABS, SBC, and latex.

  Hereinafter, a method for generating radicals in the fiber structure will be described in detail.

  As a method for generating radicals in the fiber structure, a method of irradiating the substrate with α-rays, β-rays, γ-rays, or electron beams in an inert gas such as nitrogen, argon, or helium (radiation) Irradiation method), ultraviolet irradiation method (ultraviolet (UV) method), corona discharge irradiation method (corona discharge method), plasma discharge generated by glow discharge (plasma method), or The method which combined these etc. can be mentioned. In the present invention, a radiation irradiation method or a corona discharge method for irradiating an electron beam or a corona discharge is particularly suitable.

  As a method of generating radicals in the fiber structure, α-rays, β-rays, γ-rays, electron beams, and ultraviolet rays are used in a state where the base material is impregnated with an alcohol such as isopropyl alcohol (IPA). A method of irradiating the substrate, a method of irradiating corona discharge, or a method of irradiating plasma generated by glow discharge may be used.

  Examples of UV photoinitiators include benzophenone and anthraquinone. There are a case where the energy of light absorbed by the photoinitiator moves to the polymer to create a radical, and a case where the photoinitiator radical abstracts the hydrogen of the polymer to create a radical in the polymer. In the plasma method, there are a method in which electrons in plasma form radicals in the polymer and a method in which radicals are reacted with oxygen to form peroxide radicals. The characteristics of the UV method, the plasma method, and the corona discharge method are limited to the vicinity of the surface of the substrate.

  Methods for generating radicals on the substrate include chemical initiator methods in addition to the radiation irradiation method, ultraviolet method (UV method), corona discharge method, and plasma method described above. Examples of the chemical initiator method include a chain transfer method, an emulsion polymerization method, and a cerium salt method. In the chain transfer method, peroxides such as benzoyl peroxide, azoisobutyronitrile (AIBN), and the like are used as chemical initiators.

  The radiation irradiation method of the present embodiment includes a simultaneous irradiation method and a pre-irradiation method. The simultaneous irradiation method is a method of irradiating in the coexistence of a polymer and a reactant, and the pre-irradiation method is also called a trapping radical method, and is a method of contacting a reactant after generating a radical by irradiation with radiation. The characteristics of the radiation irradiation method include that it can be used for polymers of all shapes, radicals can be generated up to the inside of the polymer, no initiator remains, and mass production is possible.

  In the present embodiment, a radiation irradiation method, a UV method, a plasma method, and a corona discharge method may be appropriately selected as a radical generation method according to the purpose and application.

  In the method of irradiating the fiber structure constituting the dust collection filter 10 used in the air cleaner 100 of this embodiment, the irradiation dose of ionizing radiation is a radical sufficient to introduce a deodorant functional group. There is no particular limitation as long as it is an economical irradiation dose with which the amount produced is obtained and unnecessary crosslinking or partial decomposition does not occur. However, the radicals are uniformly generated, and the substrate constituting the dust collection filter of the present invention Since it has little influence on the rigidity and chemical resistance, it is preferably in the range of 1 kGy to 1000 kGy, more preferably in the range of 5 kGy to 500 kGy, and particularly preferably in the range of 10 kGy to 300 kGy.

  There are many reports on radicals generated by the above-described radical generation method in polyethylene, and alkyl, allyl, polyenyl, and peroxide radicals are generated by electron beam irradiation. Radicals are generated in the crystal part and the amorphous part, but in the amorphous part where the movement of the molecular chain is intense, it immediately disappears by a reaction such as recombination. Observed are radicals in the crystal part. Alkyl radicals are extremely reactive, move through the crystal part while extracting hydrogen, and are consumed by recombination (crosslinking), oxidation reaction, and graft reaction in the amorphous part.

  Since polymer radicals are generated by a direct primary action of radiation and a secondary action by electrons ejected by incident radiation, radicals form in groups along the track of incident radiation. The size of one group is about several nm, and radical recombination occurs in this group. In addition, the generated radicals move between molecules or inside molecules by addition and extraction reactions with hydrogen, and search for radicals as binding partners. The reaction is unlikely to occur in the crystal part because the movement of the polymer is limited, but the radicals generated in the crystal part move to the amorphous part where the molecular chain can move freely and participate in the reaction.

  In this embodiment, immediately after irradiation of radiation to the fiber structure, for example, in the case of introducing the deodorant functional group within 1 to 2 minutes, the temperature at the time of irradiation and the substrate after irradiation There is no particular limitation on the storage temperature. However, when a deodorant functional group is introduced after a period of time after generating radicals, it is desirable to perform irradiation and storage at a low temperature in order to preserve the radicals. If stored at a low temperature of about −5 ° C., a reaction using polymer radicals can be performed without any problem even after 20 days of irradiation.

  As described above, after generating radicals on the surface of the fiber structure, a substance containing a deodorant functional group is brought into contact, and again irradiated with radiation such as α, γ, β rays, ultraviolet rays, electron beams, etc. By this, a deodorant functional group will be introduce | transduced into the fiber surface which comprises a fiber structure via a monomer.

  The dust collection filter 10 used in the air cleaner 100 of the present embodiment further includes at least one metal ion as a component having at least one of a bactericidal effect and an antiviral effect. In the present embodiment, when the metal ion is the above-described acidic deodorant functional group (functional group having a deodorizing property that deodorizes basic gas), the ion exchange ability of the acidic deodorant functional group It is preferable that the metal ions can be bonded to each other, and the metal ions are bonded to some of the deodorant functional groups introduced into the fiber structure. In the case of a basic deodorant functional group (functional group having a deodorizing property for deodorizing acidic gas), an anionic metal complex (complex ion) such as chloroauric acid is used to form a metal ion. Can be ionically bonded. In this way, by introducing metal ions that inactivate at least one of bacteria and viruses into a part of the deodorant functional group introduced into the fiber structure, the dust collection filter 10 constituted by the fiber structure. Can have both a deodorizing function and a bacteria and / or virus inactivating function. Therefore, the air cleaner 100 of the present embodiment can efficiently realize both the inactivation function and the deodorization function of bacteria and / or viruses collected by the dust collection filter 10. As the introduction method, since the deodorizing functional group is introduced on the surface of the fiber constituting the fiber structure by the above-described method, it is only necessary to bring the compound containing the target metal ion into contact with the fiber structure. Specifically, by adjusting the concentration of the compound containing the target metal ion, the amount of metal ion that binds to the deodorant functional group can be freely controlled. The dust collection filter 10 provided with the property and bactericidal antiviral property can be provided.

  On the other hand, as a method of fixing metal ions to the base material, the metal ions are adsorbed and supported on an inorganic porous material such as zeolite or activated carbon, and then fixed to the base material, thereby exhibiting deodorant and bactericidal antiviral properties. And a method of applying a metal complex such as phthalocyanine to a substrate and imparting deodorizing properties have been developed. However, when an inorganic porous material is used, detachment from the substrate becomes a problem, and phthalocyanine is used. In such a case, problems such as coloring and problems such as a slow deodorizing speed occur compared to ion exchange. Moreover, since there is no bactericidal / antiviral effect, it is necessary to use another functional material in combination when it is desired to give both functions of deodorizing and bactericidal / antiviral effects. Furthermore, it is difficult to control the balance between the deodorizing property and the bactericidal / antiviral properties according to the application in the method using inorganic porous or the method using metal complex to bind metal ions as described above. However, by introducing a deodorant functional group into the fiber structure as in this embodiment, and further having a structure in which a metal ion is bonded to a part of the introduced deodorant functional group, the deodorization and sterilization The effect that both antiviral properties can be achieved efficiently is obtained. Furthermore, as described above, the metal ion can be bound to the fiber structure simply by bringing the deodorant functional group introduced into the fiber structure into contact with the metal ion, so the concentration of the metal ion to be contacted can be adjusted. Since the balance between deodorant and bactericidal / antiviral properties can be easily controlled, it is easy to design according to the application.

  Specific examples of the metal ion having a bactericidal effect or an antiviral effect include Ag, Zn, Cu, Co, Ni, Al, Pt, Au, Pd, and Sn. Two or more types can be used in combination. In particular, use of Zn is preferable because discoloration of the filter can be suppressed.

  The dust collection filter 10 used in the air cleaner 100 of the present embodiment may further include inorganic fine particles that adsorb basic gas and / or inorganic fine particles that adsorb acid gas. By fixing the inorganic fine particles to the dust collecting filter 10, the deodorizing effect can be further improved. For example, even when the above-described material that is difficult to introduce the deodorant functional group is used as the base material of the filter, sufficient deodorization performance can be secured by fixing inorganic fine particles having the necessary deodorization performance.

  Specifically, the inorganic fine particles that adsorb the basic gas include silica, and the inorganic fine particles that adsorb the acidic gas include titanium oxide, zirconium oxide, aluminum oxide, magnesium oxide, and the like. In addition, as described above, inorganic fine particles provided with a basic gas or acidic gas adsorbing ability by fixing a functional group capable of adsorbing basic gas or acidic gas on the surface of the inorganic fine particles can also be used. In the case of having a functional group, the inorganic fine particles themselves may or may not have a gas adsorbing ability. The inorganic fine particles having acidic gas / basic gas adsorption characteristics in the present embodiment are concepts including those in which a functional group that adsorbs acidic gas or basic gas is introduced on the surface of such inorganic fine particles.

  The inorganic fine particles of the present embodiment described above may be fixed before the deodorant functional group described above is introduced into the fiber structure of the dust collection filter 10, or the deodorant functional group is introduced into the fiber structure. However, when the deodorant functional group is covered with a binder for fixing, it is preferable to fix before introducing the deodorant functional group.

  The inorganic fine particles that adsorb the basic gas and the acid gas used in the dust filter 10 used in the air cleaner 100 of the present embodiment can be fixed using a known binder, but the contact efficiency with the gas is taken into consideration. Then, the fixing method by radiation graft polymerization using the silane monomer which has an unsaturated bond part which can be firmly fixed to a base material even in a small amount is most preferable. These silane monomers having an unsaturated bond portion are bonded by forming a chemical bond (covalent bond) on the surface of the inorganic fine particles by a dehydration condensation reaction between the silanol groups of the silane monomer and the surface of the fine inorganic particles by a method such as reflux. Furthermore, the unsaturated bond part and the reactive functional group of the silane monomer are fixed on the substrate by chemical bonding (covalent bonding) by graft polymerization.

Examples of the silane monomer having an unsaturated bond include those having an unsaturated bond or a reactive functional group such as a vinyl group, an epoxy group, a styryl group, a methacrylo group, an acryloxy group, an isocyanate group, and a thiol group. Specifically, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltriacetoxysilane, N-β- (N-vinylbenzylaminoethyl) -γ-aminopropyltrimethoxysilane, N- (vinylbenzyl) -2 -Hydrochloride of aminoethyl-3-aminopropyltrimethoxysilane, 2- (3,4 epoxy cyclohexyl) ethyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-glycidoxypropyltriethoxysilane, p-styryltrimethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, 3-methacryloxypropyl G An alkoxysilane compound represented by reethoxysilane, 3-acryloxypropyltrimethoxysilane, 3-isocyanatopropyltriethoxysilane, Si (OR1) ₄ (wherein R1 represents an alkyl group having 1 to 4 carbon atoms), for example, tetramethoxysilane, and _{tetraethoxysilane,} R2 X Si (oR @ _{3) n} (wherein R2 is a hydrocarbon group having 1 to 6 carbon atoms, R3 is an alkyl group having 1 to 4 carbon atoms, X is (4- n), where n represents an integer of 1 to 3, for example, methyltrimethoxysilane, methyltriethoxysilane, dimethyldiethoxysilane, phenyltriethoxysilane, hexyltrimethoxysilane, And hexamethyldisilazane.

  The inorganic fine particles that adsorb basic gas or acidic gas may be fixed not only on the surface of the fiber structure as a base material but also inside the fiber structure. For example, when using a nonwoven fabric for the fiber structure used as a base material, it may be entangled and fixed together with the yarn by spraying inorganic fine particles during the manufacturing process of the nonwoven fabric. By using a non-woven fabric in which inorganic fine particles that adsorb such basic gas or acid gas are fixed, it is not necessary to fix the inorganic fine particles on the surface portion of the non-woven fabric. Is more preferable in the surface portion of the nonwoven fabric.

  The dust collection filter 10 having deodorizing properties and sterilization / antiviral properties used in the air cleaner 100 of the present embodiment described above is used as a single layer or a plurality of (two or more layers) laminated bodies according to the purpose. You can also do things.

  When the dust collection filter 10 of this embodiment is used in a single layer, both the acidic deodorant functional group that adsorbs the basic gas to the dust collection filter 10 and the basic deodorant functional group that adsorbs the acidic gas. May be introduced. If deodorant functional groups of both acidic gas and basic gas are introduced, deodorization can be performed for both gases even if the filter is a single layer. When introducing both of the deodorizing functional groups, for example, an acidic deodorizing functional group that adsorbs a basic gas is introduced on one side of the filter, and a basic adsorbing acidic gas is adsorbed on the other side. Deodorant functional groups can be introduced. Or each deodorant functional group can also be introduce | transduced with respect to the one part area | region or several area | region of the surface and the back surface. For example, an acidic and basic deodorizing functional group may be introduced in a discontinuous state such as a linear shape, a sea island shape, or a stripe shape. ,

  As described above, when deodorizing functional groups of both acidic gas and basic gas are introduced, the metal ions having bactericidal and antiviral properties adsorb the functional group that adsorbs basic gas and acidic gas. It may be fixed to both deodorant functional groups of the functional group. When it is desired to deodorize more basic gas, metal ions may be fixed to the basic deodorant functional group. In order to deodorize more acidic gas, metal ions may be fixed to the acidic deodorant functional group. What is necessary is just to select suitably the functional group which couple | bonds a metal ion according to required deodorizing performance. At this time, the inorganic fine particles that adsorb basic gas or acid gas may be further fixed in accordance with the use environment in order to improve the deodorizing function.

  When the dust collection filter 10 of this embodiment is used as a laminate of two or more layers, a filter having an acidic deodorizing functional group that adsorbs a basic gas and a basic deodorizing functional group that adsorbs an acidic gas. Filters into which groups are introduced can be stacked. By stacking the filters corresponding to the deodorization of the acid gas and the basic gas, the dust collection filter 10 can deodorize both gases.

  Further, a fiber structure having air permeability such as a nonwoven fabric or a honeycomb as a core material and a filter having a single layer structure or a multilayer structure in which the above-described deodorant functional group is introduced may be laminated. Since the strength is improved by laminating with the core material, processing such as a pleated shape for increasing the surface area of the dust collecting filter 10 is facilitated. At this time, the inorganic fine particles that adsorb basic gas or acid gas may be further fixed in accordance with the use environment in order to improve the deodorizing function.

(Another embodiment of the air purifier)
FIG. 3 shows still another embodiment of the air cleaner 100 of the present embodiment. The air cleaner 100 of FIG. 3 includes a dust collection part A including a dust collection filter 10, a discharge electrode 20, a ground electrode 30, and a power supply 40, and an ionization part B including a discharge line 60, a ground electrode 70, and a power supply 80. It is the air cleaner 100 provided. This air cleaner 100 is an example of an air cleaner characterized in that an ionization unit B that ionizes air and charges dust on the wind of the dust collection unit A is provided. When passing through the ionization part B, microorganisms such as dust, bacteria, and viruses are charged by the action of ionized air (the action of ions generated by ionizing the gas around the ionization part B). Since dust or the like is sent to and collected in the dust collecting part A, dust collection performance can be improved.

  Next, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to only these examples.

<Preparation of dust collection filter>
Hereinafter, an electron curtain type electron beam irradiation apparatus (CB250 / 15 / 180L manufactured by Iwasaki Electric Co., Ltd.) was used for the electron beam irradiation in the examples. Examples and comparative examples of the dust collection filter were produced as follows.

(Sample 1)
As a base material of the dust collection filter, a PP (polypropylene) base material melt blown nonwoven fabric (EM05010 manufactured by Toray Fine Chemical Co., Ltd.) having an electret performance was irradiated with an electron beam at an acceleration voltage of 200 kV for 5 Mrad in a nitrogen atmosphere. . The nonwoven fabric was then exposed to 30% fuming sulfuric acid for 1 hour under a nitrogen atmosphere, washed with water and neutralized to effect sulfonation. The obtained sulfonated PP nonwoven fabric was immersed in a 1% zinc sulfate aqueous solution for 20 minutes, washed with water and dried to obtain a sulfonated nonwoven fabric carrying zinc ions.

(Sample 2)
The same PP nonwoven fabric as Sample 1 was irradiated with an electron beam at an acceleration voltage of 200 kV for 20 Mrad in a nitrogen atmosphere. Subsequently, this nonwoven fabric was immersed in a 10% glycidyl methacrylate solution to carry out a graft polymerization reaction, and further sulfonated with an aqueous sodium hydrogen sulfite solution. The obtained sulfonated PP nonwoven fabric was immersed in a 1% aqueous copper sulfate solution for 20 minutes, washed with water and dried to obtain a sulfonated nonwoven fabric carrying copper ions.

(Sample 3)
A graft polymerization reaction was performed on the same PP nonwoven fabric as Sample 1 in the same manner as in Example 2. Further, the nonwoven fabric subjected to the graft polymerization reaction was immersed in a diethylamine solution for amination. The obtained aminated PP nonwoven fabric was immersed in a 1% chloroauric acid aqueous solution for 20 minutes, washed with water and dried to obtain a gold complex-carrying aminated nonwoven fabric.

(Sample 4)
As a base material having no electret performance, a PP base spunbond nonwoven fabric (P01100 manufactured by Asahi Kasei Fibers Co., Ltd.) was subjected to sulfonation in the same manner as in Sample 1. The obtained sulfonated PP nonwoven fabric was immersed in a 1% silver nitrate aqueous solution for 20 minutes, washed with water and dried to obtain a sulfonated nonwoven fabric carrying silver ions.

(Sample 5)
As another base material having no electret performance, a PE (polyethylene) base material spunbonded nonwoven fabric (S1003WDO manufactured by Unitika Ltd.) was subjected to sulfonation in the same manner as in Sample 1. The obtained sulfonated PE nonwoven fabric was immersed in a 1% aqueous silver nitrate solution for 20 minutes, washed with water and dried to obtain a sulfonated nonwoven fabric carrying silver ions.

(Sample 6)
Commercially available zirconium oxide fine particles (Nippon Denko Corporation, PCS-60) are 10.0% by mass with respect to methanol, and 3-methacryloxypropyltrimethoxysilane (Shin-Etsu Chemical Co., Ltd., KBM-503) is oxidized as a silane monomer. After adding 5.0% by mass to the zirconium fine particles and adjusting the pH to 5.0 with hydrochloric acid, it was pulverized and dispersed to an average particle size of 18 nm by a bead mill. Thereafter, solid-liquid separation was performed using a freeze dryer, and the film was heated at 120 ° C. to chemically bond the silane monomer to the surface of the zirconium oxide fine particles by a dehydration condensation reaction to form a thin film. The obtained silane monomer-coated zirconium oxide fine particles were dispersed in 10.0% by mass in methanol and pulverized and dispersed again to an average particle size of 18 nm by a bead mill, and then methanol was added to adjust the solid content to 5.0% by mass to obtain a slurry. After that, the obtained slurry was applied to one side of the sulfonated nonwoven fabric carrying zinc ions of sample 1 by spraying, dried at 80 ° C. for 1 minute, and then irradiated with an electron beam at an acceleration voltage of 200 kV for 5 Mrad, whereby a silane monomer A thin film made of zirconium oxide fine particles coated with was bonded to a nonwoven fabric to obtain a nonwoven fabric of Sample 6.

(Sample 7)
A slurry prepared in the same manner except that the zirconium oxide fine particles in sample 6 were changed to silica fine particles was applied to one side of the gold complex-carrying aminated nonwoven fabric of sample 3 by spraying, dried at 80 ° C. for 1 minute, By irradiating the wire with 5 Mrad at an acceleration voltage of 200 kV, a thin film made of silica fine particles coated with a silane monomer was bonded to obtain a nonwoven fabric of Sample 7.

(Sample 8)
The sample 1 zinc ion-supported sulfonated non-woven fabric and the sample 3 gold complex-supported aminated non-woven fabric are discharged as a hot melt adhesive from Henkel Japan Co., Ltd. MP843 in a thread form from the Nordson Co., Ltd. ALTA 400 sigleture spray gun. The nonwoven fabric of Sample 8 was obtained by pasting together.

(Sample 9)
An unprocessed product of the same PP nonwoven fabric as Sample 1 was designated as Sample 9.

(Sample 10)
A sulfonated PP nonwoven fabric obtained by subjecting the same PP nonwoven fabric as Sample 1 to sulfonation by the same method as Sample 1 was designated as Sample 10.

(Sample 11)
Sample 11 was an aminated PP nonwoven fabric obtained by subjecting the same PP nonwoven fabric as Sample 1 to amination by the same method as Sample 3.

(Sample 12)
Zirconium oxide was fixed on one side of the same non-woven PP nonwoven fabric as sample 1 by the same method as sample 6 to obtain sample 12.

(Sample 13)
Sample 13 was prepared by fixing silica fine particles on one side of the same non-woven PP nonwoven fabric as sample 1 by the same method as sample 7.

(Sample 14)
Unprocessed glass fiber paper (H-510A, Hokuetsu Kishu Paper Co., Ltd.) was used as sample 14. Table 1 shows the configuration of each sample.

<Dust collection efficiency measurement>
Next, the dust collection efficiency was measured. As shown in FIG. 2, Samples 1 to 8 shown in Table 1 were respectively installed between the electrodes, and a voltage with a potential difference of 5 kV was applied. A metal plate punched out as a discharge electrode was used, and a metal mesh was used as the ground electrode. Examples 1 to 8 were measured for dust collection efficiency at a flow rate of 20 L / min with a collection efficiency tester (manufactured by Shibata Kagaku Co., Ltd., AP-632F type) using 0.1 μm NaCl particles as test particles. It was. Moreover, what measured dust collection efficiency without applying an application to Example 1, 4, 5 was set as Comparative Examples 1-3, and measured the dust collection efficiency without applying a voltage among samples 9, 10, and 12. Are Comparative Examples 5, 7, and 9, and those in which the dust collection efficiency was measured by applying a voltage were referred to as Comparative Examples 4, 6, and 8. The results are shown in Table 2.

<Measurement of ventilation resistance>
Each sample filter having a diameter of 36 mm was used as a test specimen, and the airflow resistance in each sample at a flow rate of 20 L / min was measured using a collection efficiency tester (AP-632F type manufactured by Shibata Kagaku Co., Ltd.). . The results are shown in Table 2. The ventilation resistance shown in Table 2 is a measured value of only the sample of the filter used in each example and comparative example.

  From the above results, in Examples 1 to 3, 6 to 8 and Comparative Examples 4, 6, and 8 to which a voltage was applied, the air resistance was about 1/10 that of the HEPA filter of Comparative Example 10, but the same dust collection It was confirmed that the effect was obtained. Examples 4 and 5 and Comparative Examples 2 and 3 are ordinary nonwoven fabrics that do not have electret capability, but by comparing Examples 4 and 5 with Comparative Examples 2 and 3, applying voltage is applied. It was confirmed that the dust collection efficiency was improved by about 4 times compared to when not. In addition, from the results of Comparative Examples 5 and 7, the dust collection efficiency of the electret nonwoven fabric decreases when a functional group is introduced, but it can also be confirmed that the dust collection efficiency can be improved again by applying a voltage as in the result of Comparative Example 6. It was. From the above, it was confirmed that an air cleaner having a high dust collecting ability can be provided by installing a dust collecting filter between the discharge electrode and the ground electrode.

<Evaluation of deodorizing properties>
Samples 1, 3, and 6-14 were cut to a size of 10cm x 10cm, placed in a sampling bag, and then air containing 60ppm of ammonia as basic gas and air containing 60ppm of acetic acid as acidic gas were sampled. 5 L was sealed in the bag, and the residual concentration of each gas in the sampling bag was measured with a detector tube every predetermined time. The measurement times were 5, 15, and 30 minutes after the gas-containing air was sealed. The results are shown in Table 3.

  From the above results, in ammonia gas, a very high deodorizing effect was observed in samples 1, 6, 8, and 10 in which sulfonic acid groups were introduced, and in basic gas, samples 3 and 7 in which amino groups were introduced. 8 and 11, very high deodorizing effect was recognized. In particular, since both deodorizing functional groups were introduced in Sample 8, the deodorizing properties of both acidic and basic gases could be confirmed. Moreover, the deodorizing property of each gas was confirmed also in the sample 12 which fixed the acidic gas adsorbing inorganic fine particle, and the sample 13 which fixed the basic gas adsorbing inorganic fine particle. Furthermore, the adsorption characteristics of both acidic and basic gases could be confirmed in Samples 6 and 7 in which the deodorant functional group and the deodorant inorganic fine particles were combined. It was confirmed that Samples 9 and 14 into which neither functional groups nor deodorant inorganic fine particles were introduced had no deodorizing effect.

<Evaluation of bactericidal properties>
Escherichia coli was used for the bactericidal evaluation of the samples 1 to 14. 100 μL of the Escherichia coli suspension was dropped onto a plastic petri dish, and each filter sample cut into 2 cm × 2 cm was placed thereon. The suspension was spread over the entire surface of the sample, and then allowed to act at room temperature for 60 minutes. After 60 minutes, 1900 μL of a 20 mg / mL bouillon protein solution (SCDLP medium) was added, the bacteria were washed out by pipetting, and the supernatant was collected. Then, a 10-fold serial dilution series of the collected supernatant was prepared using SCDLP medium, and 1 mL each of the collected supernatant and each diluted liquid was placed in a petri dish, and dissolved NB agar medium was added and mixed. did. After the agar medium solidified, it was cultured at 37 ° C. The number of colonies formed was counted and the number of viable bacteria (CFU / 0.1 mL, Log10); (CFU: colony-forming unit) was calculated to evaluate the bactericidal properties against each Escherichia coli. The results are shown in Table 4.

<Evaluation of antiviral properties>
For the antiviral evaluation of each sample 1-14, influenza virus (influenza A / Kitakyushu / 159/93 (H3N2)) cultured using MDCK cells was used. 100 μL of the virus suspension was dropped onto a plastic petri dish, each filter sample cut out 2 cm × 2 cm from the top was placed, the suspension was spread over the entire surface of the sample, and then allowed to act at room temperature for 60 minutes. After 60 minutes, 1900 μL of SCDLP medium was added, the virus was washed out by pipetting, and the supernatant was collected. Thereafter, a 10-fold serial dilution series of the collected supernatant was prepared using cell culture medium (MEM). The recovered supernatant and 0.1 mL of each diluted solution were inoculated into a 6-well cell culture plate in which MDCK cells were cultured. Plaque formed by adsorbing virus to cells by standing for 60 minutes, overlaying 0.7% agar medium, culturing in 34 ° C, 5% CO ₂ incubator for 48 hours, fixing with formalin and staining with methylene blue The number was counted, and the virus infectivity titer (PFU / 0.1 mL, Log 10); (PFU: plaque-forming units) was calculated. The test results are shown in Table 4.

  From the above results, sterilization and antiviral performance were confirmed in the nonwoven fabrics of samples 1 to 8 to which metal ions were bonded, whereas samples 9 to 14 that were not bonded to metal ions had sterilization and antiviral performance. I could not confirm.

<Evaluation of floating virus removal>
Next, using the samples 1, 9, and 10, a floating virus removal test was performed with an actual machine. First, an electric dust collector in which each sample was mounted on a filter unit as shown in FIG. 2 was installed in a 1 m ³ BOX, and a voltage with a potential difference of 5 kV was applied to the dust collecting means. Using a nebulizer, a suspension containing influenza virus (influenza A / Kitakyushu / 159/93 (H3N2), approximately 1 × 10 ¹⁰ cells) was sprayed into the BOX to float the virus. After that, the electrostatic precipitator was activated and the air in the BOX was circulated at a flow rate of 0.2 m ³ / min. Floating virus in the BOX 15 minutes after circulation was collected with a gelatin filter. The collected gelatin filter was taken in a petri dish, MEM was added and placed at 37 ° C. to dissolve the gelatin filter. Thereafter, a 10-fold serial dilution series of gelatin filter solution was prepared using MEM. Gelatin filter lysate and 0.1 mL of each dilution step solution were inoculated into a 6-well cell culture plate in which MDCK cells were cultured. Plaque formed by adsorbing virus to cells by standing for 60 minutes, overlaying 0.7% agar medium, culturing in 34 ° C, 5% CO ₂ incubator for 48 hours, fixing with formalin and staining with methylene blue The number was counted and the virus infectivity titer (PFU / 0.1 mL, Log10) was calculated. From the virus infection titer (natural decay) without a dust collector (P0) and the virus infection titer after circulation (Pm), calculate the floating virus removal rate P (%) in the BOX of each sample from the following equation (1). It was.
P (%) = (1-Pm / P0) x 100 (1)
Table 5 shows the results and the configurations of the examples and comparative examples.

  Subsequently, in order to confirm whether or not the virus actually collected was inactivated, the antiviral properties of each sample after the floating virus test were evaluated by the same antiviral evaluation method as described above. The results are shown in Table 5.

  From the above results, it was confirmed that in Example 9 and Comparative Examples 11 and 12 to which a voltage was applied, the virus collection efficiency was improved as compared with Comparative Examples 13 to 15. In Example 9 and Comparative Example 13 carrying metal ions, high antiviral properties could be confirmed. From these facts, it was confirmed that the present invention can provide an air purifier having a high dust collecting ability even when the pressure loss is low and having the ability to inactivate collected bacteria and viruses.

Claims (4)

A discharge electrode to which a voltage is applied;
A ground electrode disposed opposite the discharge electrode;
A dust collection filter disposed between the discharge electrode and the ground electrode and formed of a fiber structure having air permeability, and a sulfonic acid group introduced into at least some of the fibers of the fiber structure; A dust collection filter having a metal ion selected from at least one of copper ion, silver ion, zinc ion, and gold ion that binds to a part of the sulfonic acid group of the introduced sulfonic acid group ,
Air purifier, wherein the obtaining Bei a. The dust collection filter further includes an amino group introduced into at least a part of fibers of the fiber structure and a gold ion bonded to a part of the introduced amino group. The air cleaner according to claim 1. The air cleaner according to claim 1 or 2 , wherein the dust collection filter contains inorganic fine particles having acidic gas adsorption characteristics and / or basic gas adsorption characteristics. A discharge electrode to which a voltage is applied;
A ground electrode disposed opposite the discharge electrode;
A dust collection filter disposed between the discharge electrode and the ground electrode and formed of a fiber structure having air permeability, an amino group introduced into at least some of the fibers of the fiber structure; A dust collection filter having a gold ion bonded to a part of the amino groups of the introduced amino group,
An air purifier characterized by comprising: