JP2017051384A - Air purification filter, manufacturing method of air purification filter, air cleaning machine and cleaner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an air purification filter having function for removing contamination or the like and sterilization function in addition to function for adsorbing chemicals, a manufacturing method of the air purification filter, an air cleaning machine and a cleaner.SOLUTION: By an air purification filter having a laminate by laminating fibrous materials and a conductive fiber arranged in the laminate, sterilization activities are added while improving activities for adsorbing contamination by adsorbing the contamination and further forming an electrical field in addition to adsorption function of chemicals.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an air cleaning filter for cleaning air, a method for manufacturing the air cleaning filter, an air cleaner, and a vacuum cleaner.

  Conventionally, an air cleaning filter provided with carbon nanotubes has been used to remove unnecessary substances in the air. A characteristic air cleaning filter has been proposed by taking advantage of the advantages of carbon nanotubes. For example, Patent Document 1 discloses a technology for a compact air cleaning filter by employing carbon nanotubes that have high contaminant adsorption performance.

Japanese Patent Laid-Open No. 11-22214

  In the air cleaning filter described in Patent Document 1, the adsorption of chemical substances is improved because the carbon nanotubes have a very fine structure. However, since the carbon nanotubes are arranged together in the space between the HEPA filters, they are locally present in the space, and most of the air to be cleaned escapes without contacting the carbon nanotubes. End up. Furthermore, in the air cleaning filter, in addition to the removal of chemical substances, it is required to remove contaminants that are dust components floating in the air. In addition, since many bacteria are generated on the contaminants adsorbed on the air purification filter, a function of sterilization is also required.

  The present invention has been made in view of the above points. In addition to the function of adsorbing chemical substances, the present invention also provides an air cleaning filter having a function of removing contaminants and the like, and a function of sterilization, and production of the air cleaning filter. The object is to provide a method, an air cleaner and a vacuum cleaner.

  The above object is achieved by the invention described below.

  1. An air cleaning filter comprising: a laminate in which fibrous substances are laminated; and conductive fibers arranged in the laminate.

  2. 2. The air cleaning filter according to 1 above, further comprising an electrode for applying an electric field therein.

  3. 3. The air cleaning filter according to 1 or 2, wherein the conductive fiber includes any one of carbon fiber, carbon nanotube, and carbon nanohorn.

4). One or both of carbon nanotubes and carbon nanohorns are mixed into a liquid to produce a mixed solution,
Including the mixed solution in the laminate,
4. The air purification according to 3 above, wherein one or both of carbon nanotubes and carbon nanohorns are impregnated in the laminate by evaporating or volatilizing the liquid, and one or both of carbon nanotubes and carbon nanohorns are arranged in the laminate. A method for producing a filter.

  5. The air cleaner provided with the air purifying filter as described in any one of said 1 thru | or 3.

  6). The vacuum cleaner provided with the air purifying filter as described in any one of said 1 thru | or 3.

  To provide an air purifying filter having a function of removing contaminants, a function of sterilization, a method for producing an air purifying filter, an air purifier, and a vacuum cleaner in addition to the function of adsorbing chemical substances. Can do.

It is a schematic diagram of the air purification filter 1 which concerns on 1st embodiment. It is an enlarged view of the inside of the air purification filter 1. FIG. It is a schematic diagram of the fibrous material laminated body 17 which comprises the air purifying filter 1. FIG. 1 is a schematic view of carbon fiber 18. FIG. It is a schematic diagram showing the relationship of arrangement of fibrous substance 16 and carbon fiber 18. It is a figure which shows a mode that the air purifying filter 1 is adsorbing the contaminations 70 and 72. It is a schematic diagram of the air purification filter 100 which has a function to apply an electric field inside. It is the schematic which expanded a part in the air purification filter 100. FIG. It is a schematic diagram showing the behavior of ions in the bacteria 30 in the electric field 28. It is a schematic diagram explaining the mechanism in which the contamination 72 is electrically adsorbed by the air purification filter 100. It is an example of a pulse electric field. It is a schematic diagram of the air purification filter 100 at the time of arrange | positioning a point electrode diagonally according to positive / negative. It is a schematic diagram of air purification filter 100 at the time of arranging the electrode of the same pole and arranging a point electrode. It is a schematic diagram of air purification filter 40 at the time of arranging a plurality of air purification filters 100 in series. 1 is a schematic diagram of an air purifier 200 that employs an air purifying filter 100. FIG. FIG. 3 is an enlarged view of the inside of the air cleaning filter 11. 2 is a schematic diagram of a carbon nanotube 20. FIG. FIG. 3 is a schematic diagram showing the relationship between the arrangement of fibrous substances 16 and carbon nanotubes 20. It is a schematic diagram which shows a mode that the air purifying filter 11 is adsorbing the contaminants 70 and 72. It is the schematic which expanded a part in the air purification filter 101. FIG. It is a schematic diagram explaining the mechanism in which the contamination 72 is electrically adsorbed by the air purification filter 101. It is a schematic diagram of the experimental system used for experiment.

  Hereinafter, the first embodiment of the present invention will be described. FIG. 1 is a schematic diagram of an air purification filter 1 according to the first embodiment. FIG. 2 is an enlarged view of the inside of the air purification filter 1. The air cleaning filter 1 has a flat plate shape as shown in FIG. As shown in FIG. 2, the air purification filter 1 includes a fibrous material laminate 17 in which fibrous materials 16 are laminated, and conductive fibers 18. FIG. 3 is a schematic diagram of the fibrous material laminate 17 constituting the air cleaning filter 1. The fibrous substance 16 has a thickness of several μm or more and a length of several tens of μm or more. A large number of these fibrous substances 16 are entangled with the inside of the air cleaning filter 1. Specific examples of the fibrous material 16 include nylon fiber and polyester fiber, acrylic fiber, natural pulp, synthetic pulp, plain paper, western paper, Japanese paper, and the like.

  The fibrous material laminate 17 is formed of the above-described material and is stacked in a fibrous shape, so that it has countless minute ventilation holes, and is in the form of paper or nonwoven fabric as a whole. And can be used as a normal filter substrate. The diameter of the infinite number of minute ventilation holes is not particularly limited.

  FIG. 4 is a schematic view of the conductive fiber 18. The conductive fiber is a fiber having conductivity. Conductive fibers include those in which synthetic conductive metals and graphite are uniformly dispersed in synthetic fibers, metal fibers obtained by fiberizing metals such as stainless steel, and the surfaces of organic fibers coated with metal, There are carbon fibers and the like in which the surface of the organic fiber is coated with a resin containing a conductive substance. As an example of the thing which coat | covered the surface of the organic substance fiber with the metal, there exists the thing which made the metal nickel film | membrane deposit by performing electroless nickel plating processing to the fiber of paper, such as Japanese paper. In this embodiment, any conductive fiber may be used.

  The following description is based on carbon fiber as an example of conductive fiber. The raw material of the carbon fiber 18 is an acrylic long fiber that is a synthetic fiber, or coal tar or petroleum pitch. A product made from the former is called a PAN (pan) -based carbon fiber, and a product made from the latter is called a pitch-based carbon fiber. Either carbon fiber 18 may be employed in the present embodiment. First, a method for producing a PAN-based carbon fiber will be described. The raw fiber is first heat-treated in air at 200 to 300 ° C. By this treatment, the fiber becomes a flame resistant fiber having a structure resistant to fire and heat. The fiber that has been flame-resistant is then baked at a temperature of 1000 ° C. or higher in the absence of oxygen to become carbon fiber 18.

Next, a method for producing pitch-based carbon fibers will be described. The raw material is refined, heated and melted, and discharged from a die having a large number of pores to make pitch fibers. Subsequently, it heat-processes in the air at 150-400 degreeC. The fiber that has undergone such treatment becomes an infusible fiber that does not melt even at high temperatures.
Next, it is baked at a temperature of 800 to 1500 ° C. in the absence of oxygen to form carbon fibers 18. Furthermore, when making highly elastic carbon fiber, it bakes at the temperature of 1500-3000 degreeC in the state without oxygen further. The carbon fiber 18 thus produced reaches a length of 0.2 μm to 2000 μm and has a diameter of about 0.05 to 10 μm.

  FIG. 5 is a schematic diagram illustrating the relationship between the arrangement of the fibrous substance 16 and the carbon fiber 18. As shown in FIG. 5, the fibrous material 16 is formed in a complicated manner in the fibrous material laminate 17, and the carbon fibers 18 are arranged entangled with the fibrous materials 16. . The carbon fibers 18 extend three-dimensionally so as to sew a gap formed by the fibrous substances 16.

  Such a structure can be produced by laminating the carbon fibers 18 together when the fibrous substance 16 is laminated to produce the fibrous substance laminate 17. Alternatively, the fibrous material laminate 17 can be produced by immersing the fibrous material laminate 17 in a dispersion liquid in which the carbon fibers 18 are dispersed and then drying.

  FIG. 6 is a diagram illustrating a state in which the air cleaning filter 1 is adsorbing the contaminants 70 and 72. A gap generated by the intertwining of the fibrous substance 16 and the carbon fiber 18 serves as a sieve, and adsorbs chemical substances, contaminants, and bacteria. Since the carbon fiber 18 is arranged so as to extend into the space formed by the fibrous material 16, the space is reduced, so that contamination, fungi, and chemical substances are easily exposed to the carbon fiber 18, compared to the conventional case. Contaminants, fungi, and chemical substances can easily adsorb the carbon fiber 18.

  Further, as will be described later, when an electric field is applied to the inside of the air cleaning filter 1, the contaminants 70 and 72 are polarized by the electric field, and positive and negative charges are generated on the surfaces of the contaminants 70 and 72. Contaminations 70 and 72 charged with such electric charges move in accordance with the direction of the electric field, and are more easily adsorbed to the carbon fiber 18 than when there is no electric field. In addition, if the fibrous substance 16 is polarized by an electric field, the contaminants 70 and 72 are attracted to the polarization of the fibrous substance 16 by being pulled by the polarization charge. Thus, the air purification filter 1 of the present invention can be used as a filter material for ordinary air cleaners, masks and the like.

  In the air cleaning filter 1, in addition to adsorption of chemical substances, contaminants are adsorbed and fungi are also adsorbed. Examples of bacteria captured on the air cleaning filter include Escherichia coli and staphylococci. The size of E. coli is about 0.5 μm × 2 μm, and the size of staphylococci is about 0.8 μm × 1.0 μm. Other examples of bacteria that may occur include Mycobacterium tuberculosis 0.5 μm × 0.5 μm, Diphtheria bacteria size 0.6 μm × 5 μm, Shigella bacteria size 0.5 μm × 2 μm, typhoid The size of the bacteria is 0.6 μm × 2 μm, the size of Bordetella pertussis is 0.3 μm × 0.7 μm, and the size of Vibrio cholerae is 0.6 μm × 3 μm.

  Such germs should be sterilized because they will proliferate if left untreated and are dispersed to the outside in accordance with the flow of air flowing into the air cleaning filter 1 and adversely affect the human body and the like. Therefore, in the present invention, sterilization is performed using electric force.

  FIG. 7 is a schematic diagram of an air cleaning filter 100 having a function of applying an electric field therein. An electrode 5 and an electrode 6 are provided on the upper surface of the air cleaning filter 1. A voltage is applied between the electrode 5 and the electrode 6 using the power source 7. As the conductive material in the air cleaning filter 100, a silver thin film, a copper thin film, or the like can be adopted. In order to efficiently apply an electric field to the air cleaning filter 1, a conductive adhesive such as a conductive paste is used so that there is no air layer between the air cleaning filter 1 and the electrodes 5, 6. 6 is preferably fixed to the air cleaning filter 1.

  Next, a mechanism for electrically adsorbing or sterilizing contaminants will be described. First, a mechanism in which contaminants are sterilized by the air cleaning filter 100 will be described. FIG. 8 is an enlarged schematic view of a part of the air cleaning filter 100. An electric field 28 is formed around the fibrous material 16 and the carbon fiber 18. Although the electric field is incident on the surface of the carbon fiber 18 that is a conductive member substantially perpendicularly, it is assumed that the electric field is uniformly formed in the y direction in order to show the outline in the drawing. In the electric field 28, electrons move in the carbon fiber 18 that is a conductive member. The dotted line with the code | symbol 26 shows an electric current. Bacteria provide cells, and there are unicellular bacteria and multicellular bacteria. The cell surface is covered with a cell membrane, and the inside of the cell is mainly composed of cytoplasm. From an electrical viewpoint, the lipid bilayer of the cell membrane is an insulator, and the cytoplasm is a conductive fluid containing ions. Bacteria are close to insulators, but moisture that is a conductor is formed around the bacteria, and when current enters the moisture, Joule heat is generated based on the resistance value of the moisture and the magnitude of the current, The fungus is heated and killed.

  FIG. 9 is a schematic diagram showing the behavior of ions in the bacterium 30 in the electric field 28. When the electric field 28 is applied to the cell, a force that moves ions existing in the cytoplasm by electric force works. When ions move inside the cell, force is applied to the cell membrane 32 of the fungus. The cell membrane 32 is thinned by the force, and the cell membrane 32 is perforated. When the electric field is weak, even if the hole is small, the cell can self-repair and close the hole. However, if the force of the electric field is large, a large hole opens, so that the cell cannot self-repair and cell death occurs.

  As described above, bacteria are killed by the effect of Joule heat generated by current and the effect of opening a hole in the cell membrane by an electric field. Two effects are produced while applying the same voltage. Considering the waveform of the applied voltage, the following can be said. Since Joule heat is considered to be approximately proportional to the input power into the cell, it does not depend on the electric waveform generated by the power supply 7 input to the air purification filter 100. On the other hand, when a hole is opened in the cell membrane 32 by an electric field, it is considered that the higher the peak value of the electric field, the higher the effect of opening the hole in the cell membrane 32. Therefore, when the input power is the same, a pulse electric field is applied. Is desirable.

  Next, a mechanism in which contaminants and bacteria are electrically adsorbed by the air cleaning filter 100 will be described. FIG. 10 is a schematic diagram for explaining a mechanism in which the contamination 72 is electrically adsorbed by the air cleaning filter 100. The mechanism for adsorbing contaminants 72 and bacteria is substantially the same. Since an electric field is applied to the inside of the air cleaning filter 100, the contamination 72 is polarized by the electric field, and positive and negative charges are generated on the surface of the contamination 72. Contamination 72 charged with such electric charges moves in accordance with the direction of the electric field, and is more easily adsorbed to the carbon fiber 18 than when there is no electric field.

  In addition, as shown in FIG. 10, the carbon fiber 18 may be polarized by an electric field. If the carbon fiber 18 is polarized, it is pulled by the polarization charge, and the contaminants 70 and 72 are adsorbed to the polarization portion of the carbon fiber 18. In this way, the contamination 72 is polarized by the electric field and is electrically adsorbed by the air cleaning filter 100.

  FIG. 11 is an example of a pulse electric field. 11A is a partial pulse waveform of a sine wave, FIG. 11B is a square wave pulse waveform, FIG. 11C is a triangular pulse waveform, and FIG. 11D is a sine wave. AC waveform. (A), (b), and (c) of the same figure represent the shape of the pulse waveform, and (d) of the same figure represents alternating current using a sine wave. Each waveform has a bottom value of 0, but may have a bias, and the bias may be positive or negative. Although FIG. 11D shows an alternating current using a sine wave, an alternating current waveform using a square wave or a triangular wave may be used as shown in FIGS. The peak value is higher than the power value is a sine wave or a triangular wave. A sine wave is desirable in terms of easy waveform creation.

  About the position of the electrode in the air purification filter 100, the one surface of the air purification filter 100 may be sufficient, and you may use one each for front and back. The greater the applied voltage, the greater the effect of purifying air and the greater the effect of sterilization. An AC voltage of 100 V, which is a household voltage, may be used, or a transformer may be provided so that a larger voltage can be obtained. Moreover, although it does not specifically limit about the frequency of an applied voltage, 50-60Hz of household power supplies can be used.

  FIG. 12 is a schematic diagram of the air purification filter 100 when the point electrodes are arranged obliquely according to positive and negative. In FIG. 12, four electrodes 36 are arranged on the upper surface of the air cleaning filter 1, and there are two positive electrodes and two negative electrodes, which are arranged obliquely. Since the strength of the electric field between the adjacent electrodes is the largest, the closer to the periphery of the air cleaning filter 1, the higher the effect of contaminants being electrically adsorbed or sterilized.

  FIG. 13 is a schematic diagram of the air cleaning filter 100 when the point electrodes are arranged with the electrodes having the same poles aligned. In FIG. 13, four electrodes 36 are arranged on the upper surface of the air cleaning filter 1, so that there are two positive electrodes and two negative electrodes respectively, and two positive electrodes and two negative electrodes are aligned with one another. Has been placed. In the case of the electrode arrangement of FIG. 13, the strength of the electric field from the positive electrode to the negative electrode is close to that of the electrode arrangement shown in FIG. 7, so that contamination and bacteria are relatively uniformly distributed without depending on the location. The effect of being electrically adsorbed or sterilized can be obtained.

  As described above, the distribution of the electric field generated between the electrodes differs depending on the arrangement of the positive and negative electrodes, and a difference occurs in the electric charge applied to the fibrous substance 16 and the carbon fiber 18. The arrangement of the electrodes may be selected according to the design of the air cleaner.

  In addition, about an electrode, a silver thin film, a copper thin film, etc. are employable as an electroconductive material. In order to efficiently apply an electric field to the air cleaning filter 1, a conductive adhesive such as a conductive paste is used so that there is no air layer between the air cleaning filter 1 and the electrodes 5, 6. 6 is preferably fixed to the air cleaning filter 1.

  In the above description, the state where one air purification filter 1 is used is shown, but the function of air purification can be improved by arranging a plurality of air purification filters 1 in series. FIG. 14 is a schematic diagram of the air purification filter 40 when a plurality of air purification filters 100 are arranged in series. The air 42 sucked into the air cleaning filter 40 is purified as the number of the air cleaning filters 100 increases. However, if the number of the air cleaning filters 100 is too large, air is sucked into the air cleaning filter 40. Resistance increases, and the amount of air that can be processed by the air cleaning filter 40 decreases. Therefore, it is desirable to select an optimal number of air purification filters 100 according to circumstances.

  FIG. 15 is a schematic diagram of an air purifier 200 that employs the air purifying filter 100. The air cleaner 200 includes a housing 112, an air cleaning filter 100, and a fan 110. The power source 7 drives the air cleaning filter 100. The casing 112 is provided with an operation panel (not shown) and is set so that the fan 110 can be driven when the power source 7 is turned on / off. When the fan 110 is driven, external air is sucked from the vent hole 114, and the sucked air is sterilized while being contaminated through the air cleaning filter 100, and the purified air passes through the fan 110. It is sent to the outside through an air outlet (not shown) on the housing 112. It is also possible to employ the air cleaning filter 100 in a vacuum cleaner. The air hole 200 in the air purifier 200 according to FIG. 15 may have a circular shape, for example, and may have a structure in which a hose with a head for sucking dust is connected to the air hole 114.

  Next, a second embodiment will be described. The difference between the first embodiment and the second embodiment is that, in the second embodiment, carbon nanotubes or carbon nanohorns are used as the conductive fibers instead of the carbon fibers 18. Therefore, the difference between the first embodiment and the second embodiment will be mainly described. The air purification filter 11 which concerns on 2nd embodiment makes flat form similarly to the air purification filter 1 concerning 1st embodiment shown in FIG.

  FIG. 16 is an enlarged view of the inside of the air purification filter 11. The air cleaning filter 11 includes a fibrous material laminate 17 in which fibrous materials 16 are laminated and a carbon nanotube 20. The carbon nanohorn is similar to a carbon nanotube having a structure in which graphene is bent into a cylindrical shape and has similar characteristics. Therefore, in the following description, it is assumed that the carbon nanohorn is included in the carbon nanotube. The fibrous material laminated body 17 which comprises the air purification filter 1 is the same as that of what was shown in FIG. In order to make the explanation easy to understand, the dimensions are changed as shown in FIG. The fibrous substance 16 has a thickness of several μm or more and a length of several tens of μm or more. Many of these fibrous substances 16 are entangled with the inside of the air cleaning filter 11. Specific examples of the fibrous material 16 include nylon polyester fiber, acrylic fiber, natural pulp, synthetic pulp, plain paper, western paper, Japanese paper, and the like.

  The fibrous material laminate 17 is formed of the above-described material and is stacked in a fibrous shape, so that it has countless minute ventilation holes, and is in the form of paper or nonwoven fabric as a whole. And can be used as a normal filter substrate. The diameter of the innumerable minute ventilation holes is not particularly limited, but is preferably several μm or more because the length of carbon nanotubes described later is about 10 μm.

  FIG. 17 is a schematic view of the carbon nanotube 20. FIG. 18 is a schematic diagram showing the arrangement relationship between the fibrous substance 16 and the carbon nanotube 20. The fibrous substance 16 is formed in a complicated manner in the fibrous substance laminate 17, and the carbon nanotubes 20 are arranged so as to be entangled with the fibrous substances 16. The carbon nanotube 20 is preferably a porous carbon nanotube in which an infinite number of holes are formed.

  The carbon nanotubes 20 include single-walled carbon nanotubes and multi-walled carbon nanotubes. Single-walled carbon nanotubes are seamless cylindrical materials formed from single-layer graphene. Graphene is a sheet of sp2-bonded carbon atoms with a thickness of 1 atom, and has a hexagonal lattice structure like a honeycomb made of carbon atoms and their bonds.

  Multi-walled carbon nanotubes have a complicated and diverse structure compared to single-walled carbon nanotubes. Multi-walled carbon nanotubes have a structure in which a plurality of tubes of graphene are stacked concentrically, for example. In addition, there is a scroll type in which one piece of graphene sheet is wound, or a combination of them. As a typical size of the multi-walled carbon nanotube, the average diameter is 10 to 15 nm and the average length is about 10 μm. Multi-walled carbon nanotubes have the advantages of being easier to mass-produce than single-walled carbon nanotubes, lower cost per unit, and superior in thermal and chemical stability, and multi-walled carbon nanotubes are also desirable in the present invention.

  The carbon nanotube 20 can be produced by a known method. For example, it can be produced by patterning an Fe film on at least one surface of a silicon substrate by photolithography and subjecting this surface to a general chemical vapor deposition method (CVD method) using acetylene gas. In this method, the carbon nanotubes 20 can be formed to protrude vertically on the substrate with a multilayer structure. The plurality of carbon nanotubes 20 are preferably intertwined with each other. The plurality of carbon nanotubes 20 are entangled with each other, whereby the plurality of carbon nanotubes 20 are reinforced to increase rigidity. The tip of the carbon nanotube 20 may be either closed or open.

  In order to prepare the air purification filter 1 of the present invention, for example, the fibrous material laminate 17 is immersed in an aqueous dispersion impregnated with the carbon nanotubes 20. In order to prepare this aqueous dispersion, first, a mixed solution of distilled water and, for example, ethanol is prepared. Next, the carbon nanotube 20 powder is put into this mixed solution, stirred with a stirrer, heated with stirring, for example, heated for 0.5 hour to evaporate ethanol to obtain an aqueous dispersion.

  The aqueous dispersion of carbon nanotubes is included in the laminate of the fibrous material 16, and the aqueous dispersion is evaporated while being heated, so that the fibrous material laminate 17 is impregnated with the carbon nanotubes 20 and the fibrous material laminate 17. The carbon nanotubes 20 are placed inside. Thus, the carbon nanotubes 20 are arranged on the fibrous material laminate 17 to obtain the air cleaning filter 1. When the aqueous dispersion is evaporated, it is evaporated so as not to completely block the micro vent.

  FIG. 18 is a schematic diagram showing the arrangement relationship between the fibrous substance 16 and the carbon nanotube 20. As shown in FIG. 18, the fibrous substance 16 is formed in a complicated manner in the fibrous substance laminate 17, and the carbon nanotubes 20 are arranged entangled with the fibrous substances 16. .

  FIG. 19 is a schematic diagram illustrating a state in which the air cleaning filter 11 is adsorbing the contaminants 70 and 72. The mechanism for adsorbing bacteria is the same. A gap generated by the intertwining of the fibrous substances 16 serves as a sieve, and adsorbs contaminants and bacteria. Further, the carbon nanotubes 20 can fill the gaps and adsorb contaminants and bacteria. When the carbon nanotube 20 is a porous type, many small holes are opened on the surface of the carbon nanotube 20, and small contaminants are adsorbed in the holes in addition to chemical substances.

  The difference from the air purification filter 11 of the first embodiment is that the carbon nanotubes 20 are smaller than the carbon fibers 18, and the carbon nanotubes 20 are arranged so as to be entangled with the fibrous material 16. And since the carbon nanotube 20 enters into the space where the fibrous substances 16 are intermingled, the carbon nanotubes 20 can also adsorb contamination and bacteria that have passed through the space where the fibrous substances 16 are intermingled. . The carbon nanotubes 20 also have a large chemical substance adsorption effect.

  About the air purifying filter 101 of 2nd embodiment, the sterilization effect | action can be given by applying an electric field similarly to the air purifying filter 100 of 1st embodiment. A schematic diagram of the air cleaning filter 101 having a function of applying an electric field is the same as that of FIG. 7, FIG. 12, and FIG.

  FIG. 20 is a schematic diagram in which a part of the air cleaning filter 101 is enlarged. An electric field 28 is formed around the fibrous substance 16 and the carbon nanotube 20. Although the electric field is incident on the surface of the carbon nanotube 20 that is a conductive member substantially perpendicularly, it is assumed that the electric field is uniformly formed in the y direction in order to illustrate the outline. In the electric field 28, electrons move to the carbon nanotube 20 which is a conductive member. A plurality of the carbon nanotubes 20 are intertwined in a complicated manner, and are attached to the fibrous substance 16. Therefore, current flows through a bundle of carbon nanotubes 20 that are intertwined in a complicated manner. The dotted line with the code | symbol 26 shows an electric current.

  The mechanism by which the bacteria adsorbed in the air cleaning filter 101 are killed by applying an electric field is the same as described above. That is, there are a mechanism in which Joule heat is generated by an electric current and the bacterium is heated and killed, and a mechanism in which a force is applied to the cell membrane 32 of the bacterium by an electric field and the cell membrane 32 is destroyed to cause cell death.

  FIG. 21 is a schematic diagram for explaining a mechanism in which the contamination 72 is electrically adsorbed by the air cleaning filter 101. The mechanism for adsorbing bacteria is the same. Since an electric field is applied to the inside of the air cleaning filter 101, the contamination 72 is polarized by the electric field, and positive and negative charges are generated on the surface of the contamination 72. Contamination 72 charged to such a charge moves in accordance with the direction of the electric field, and is more easily adsorbed to the carbon nanotube 20 than when there is no electric field. The difference from the first embodiment is that the carbon nanotubes 20 are smaller and more numerous than the carbon fibers 18, so that the number of occurrences of polarized portions increases, and more fine contaminants and bacteria can be adsorbed.

Next, in order to confirm the effect of the present invention, an experiment was performed to confirm the effect of sterilization using the air cleaning filter 101 according to the second embodiment. FIG. 22 is a schematic diagram of an experimental system used in the experiment. The length of the electrodes 5 and 6 on the air cleaning filter 101 is 15 cm, and the distance between the electrodes 5 and 6 is also 15 cm. Pork 45 was placed on the air purification filter 101 for 1 week to propagate general viable bacteria. Thereafter, the pork 45 was removed, and a rectangular-wave voltage pulse having a period of 10 Hz, a pulse width of 1 ms, a bottom value of 0 V, and a peak value of 30 V was applied between the electrodes 5 and 6 for 10 minutes. Then, general viable bacteria propagated on the air purification filter 101 were collected with a cotton swab. The collected general viable bacteria were applied on an agar medium and cultured at a culture temperature of 35 degrees for 48 hours, and then the number of bacteria was counted. As a comparative example, the same experiment was performed without placing pork 45. Table 1 shows the experimental results.
From this result, the number of bacteria was suppressed to one tenth by the effect of the air purification filter 100 according to the present embodiment, and the effect of sterilization of the air purification filter 100 according to the present embodiment was confirmed. . The above voltage pulse conditions are only examples, and other conditions, for example, when the voltage value is lowered to 1V, when the pulse period is lowered to 1 Hz and the pulse interval is increased, or the pulse width is increased to 100 ms. In some cases, experiments were conducted in which various conditions were combined. As a result, when the voltage was applied, the result that the number of bacteria was suppressed to one tenth was the same as when the voltage was not applied. It was found that the number of bacteria can be suppressed in proportion to the increase in the voltage peak value. In addition, the number of bacteria was reduced in proportion to the duty ratio which is the ratio of the pulse width to the pulse interval.

  As described above, according to the present invention, the conductive fiber includes the fibrous material by including the laminated body in which the fibrous material is laminated and the conductive fiber disposed in the laminated body. Because it is arranged so as to extend into the space, the space becomes smaller, so contamination, fungi, and chemical substances are easily exposed to conductive fibers, and in addition to the function of adsorbing chemical substances, it is easier than before In addition, it becomes possible to adsorb contaminants and bacteria.

  Further, according to the present invention, by providing an electrode for applying an electric field inside the air purification filter, in addition to the function of adsorbing chemical substances, the function of removing contaminants and the like, It is possible to provide an air purifying filter having the above functions.

  In addition, according to the present invention, the conductive fiber includes any one of carbon fiber, carbon nanotube, and carbon nanohorn. Therefore, when the carbon fiber is used, the carbon fiber itself has the ability to adsorb contaminants and bacteria. Since it is high, a high-performance air purification filter can be provided. Moreover, since carbon fiber has high electrical conductivity, it becomes easy to adsorb contamination and bacteria when polarized.

  When carbon nanotubes or carbon nanohorns are used, the size is smaller than that of carbon fibers and the number of carbon nanohorns is larger, so that it is possible to adsorb smaller and more numerous contaminants and bacteria. In addition, the fact that the carbon nanotubes are smaller and larger in number than the carbon fibers increases the number of occurrences of small polarization parts, so that it is possible to adsorb more fine contaminants and bacteria.

  Further, according to the present invention, one or both of carbon nanotubes and carbon nanohorns are mixed with a liquid to produce a mixed liquid, the mixed liquid is included in the laminate, and the liquid is evaporated or volatilized to By impregnating one or both of carbon nanotubes and carbon nanohorns in the laminate and placing one or both of carbon nanotubes and carbon nanohorns in the laminate, one or both of carbon nanotubes and carbon nanohorns are placed in the air purification filter. Thus, it is possible to provide a manufacturing method capable of manufacturing an air cleaning filter in which the filter is uniformly arranged.

  Moreover, according to this invention, while providing an air purifying filter, while purifying air efficiently, the air cleaner which is hard to propagate a microbe can be provided.

  Moreover, according to this invention, while providing an air purifying filter, while being able to purify | clean air efficiently, the vacuum cleaner which is hard to propagate a microbe can be provided.

1, 11, 40, 100, 101 Air purification filter 5, 6, 36 Electrode 7 Power source 16 Fibrous material 17 Fibrous material laminate 18 Carbon fiber 20 Carbon nanotube 28 Electric field 32, 56 Cell membrane 45 Pork 70, 72 Contamination 110 Fan 112 Housing 114 Ventilation hole 200 Air purifier

Claims (6)

  An air cleaning filter comprising: a laminate in which fibrous substances are laminated; and conductive fibers arranged in the laminate.   The air purification filter according to claim 1, further comprising an electrode for applying an electric field therein.   The air cleaning filter according to claim 1, wherein the conductive fiber includes any one of carbon fiber, carbon nanotube, and carbon nanohorn. One or both of carbon nanotubes and carbon nanohorns are mixed into a liquid to produce a mixed solution,
Including the mixed solution in the laminate,
The air cleaning according to claim 3, wherein one or both of carbon nanotubes and carbon nanohorns are disposed in the laminate by impregnating the laminate with one or both of carbon nanotubes and carbon nanohorns by evaporating or volatilizing the liquid. Of producing a filter.   The air cleaner provided with the air purifying filter as described in any one of Claims 1 thru | or 3.   A vacuum cleaner comprising the air purification filter according to any one of claims 1 to 3.