JP2008114109A - Flame-retardant ozone/voc removing filter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a flame-retardant ozone/VOC removing filter which is excellent in fire retardance, ozone decomposition and VOC removal, and can exhibit excellent properties in various electronic apparatuses, air conditioners, etc. without inhibiting fire retardance especially applied according to design. <P>SOLUTION: The flame-retardant ozone/VOC removing filter is made by carrying activated carbon particles impregnated with potassium carbonate on a cover material containing a fire retardant and made of fabric. The amount of the impregnated potassium carbonate is 1-3 mass%. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

The present invention relates to a filter for removing ozone and VOC by being incorporated in electronic devices such as laser printers and various air conditioners, and in particular, without reducing the effectiveness of flame retardants. The present invention relates to a flame retardant ozone VOC removal filter having both functions of decomposing ozone and adsorbing volatile organic compounds.

  Conventionally, it has been regarded as a problem that ozone generated due to a discharge phenomenon or the like in an apparatus adversely affects a human body when the electronic apparatus is used. As a technique for decomposing and discharging such ozone in an electronic device, for example, in Japanese Patent Laid-Open No. 2006-119313 (hereinafter referred to as Patent Document 1), an exhaust discharge path for discharging the air inside the image forming apparatus main body to the outside An adsorption filter that is provided in the exhaust passage and can remove the compounds in the exhausted air by adsorption; and a catalyst filter that is provided in the exhaust exhaust passage and that decomposes and removes the compounds in the exhausted air with a catalyst; The above-described adsorption filter is disposed on the upstream side in the exhaust direction, and the catalyst filter is disposed on the downstream side, and an image forming apparatus including the exhaust device is proposed. Has been.

  According to this Patent Document 1, in a so-called image forming apparatus such as a printer, a copying machine, or a facsimile that heats and fixes a toner image on a recording material, a fine image of high-definition dots is obtained as in the case of using ink. It has been demanded. Under such a background, the use of coated paper coated with a chemical substance on the surface of high-quality paper and finished in a glossy or matte tone is expanding. For example, when the above-described toner image is heated and fixed at about 180 ° C. Volatile organic compounds (hereinafter referred to as VOC [Volatile Organic Compound]) were generated from the coated paper, and together with the ozone described above, the use environment of the apparatus was deteriorated. Therefore, in this document technique, an exhaust discharge path that discharges air inside the image forming apparatus main body to the outside, an adsorption filter that is provided in the exhaust discharge path and can remove compounds in the discharged air by adsorption, and the exhaust A catalyst filter that is provided in the discharge path and decomposes and removes the compounds in the discharged air with a catalyst, and the adsorption filter is disposed on the upstream side along the exhaust direction, and the catalyst described above is disposed on the downstream side. A configuration in which a filter is arranged is adopted. In addition, as a material constituting these filters, activated carbon is woven fabric, non-woven fabric, a material using a mechanical removal action carried on a thin plate, or a precious metal system such as platinum or palladium, or a base metal system such as manganese or iron. The thing using the chemical removal effect | action which carry | supported the oxidation catalyst with base materials, such as a woven fabric, a nonwoven fabric, and a thin plate, is disclosed.

  In addition, as a filter for decomposing ozone generated in such an image forming apparatus, Japanese Patent Laid-Open No. 2004-313880 (hereinafter referred to as Patent Document 2) has a toluene adsorption amount of 5 mg / cc or more on the exhaust path and upstream side. Has been proposed, and an ozone filter employing a configuration in which a metal oxide-carrying filter having an acetic acid adsorption amount of 2.5 mg / cc or more is arranged downstream is proposed. In this technology, for example, wood (charcoal), sawdust, fruit husk (coconut husk, rice husk, coffee beans, etc.), cellulose, lignin, pulp, and other plant materials such as lignite, lignite, peat, It is disclosed to employ activated carbon obtained by using mineral raw materials such as anthracite and petroleum sludge as raw materials, chemical activation using zinc chloride or gas activation using water vapor, etc. As a metal oxide-carrying filter, a single oxide or composite oxide such as manganese, copper, cobalt, nickel, iron, nickel, titanium or silver is used, and a single oxide or composite oxide of manganese is particularly preferable. Is disclosed to be adopted. As a more specific embodiment of each supported filter, there is a description that it is preferable to perform pleating or honeycomb processing using urethane or nonwoven fabric as a base material.

  Furthermore, as a technique similar to Patent Document 2 described above, Japanese Patent Application Laid-Open No. 2000-1557827 (hereinafter, Patent Document 3) is a gas adsorption sheet in which a gas adsorption layer is formed on both surfaces of a sheet base material. In addition, a gas adsorption sheet is disclosed in which the gas adsorption layer includes activated carbon, at least one of an alkali metal compound and an alkaline earth metal compound, and a hardly soluble flame retardant. In this publication, in order to improve the ozone removal performance itself by activated carbon, an activated carbon molded body in which potassium compound and sodium compound are mixed with activated carbon, or an alkali metal compound or alkaline earth metal compound is attached to a specific activated carbon and heat-treated. A technique using activated carbon is disclosed as a conventional background art. And in office equipment such as the above-described image forming apparatus, the standard “UL 94: Standard for Safety of Plastics of Plastics of the Standards for Flammability Test” issued by UL (Underwriters Laboratories Inc.). (Hereinafter referred to as Non-Patent Document 1), the alkali metal compound and alkaline earth metal added to the activated carbon to assist the ozonolysis function promote the flammability of the activated carbon, It is described as being impractical. In addition, the conventional technology containing water-soluble inorganic compounds such as ammonium phosphate has been mentioned, and although some achievements have been obtained from the viewpoint of flame retardancy, the ozonolysis active sites on activated carbon have been obtained by the inorganic compounds. It raises the problem of decreasing, and it is described that a flame retardant reacts with an alkali metal to form a substance such as sodium phosphate to coat an ozonolysis active site on activated carbon.

  Specific examples of the alkali metal compound and the alkaline earth metal compound applied to Patent Document 3 include alkali metal hydroxides such as sodium, potassium and lithium; oxides; carbonates and carbonates. Water-soluble salts such as hydrogen salt, acetate salt, oxalate salt, phosphate salt, sulfate salt, succinic acid, phthalic acid, hydrogen phthalate; halides, etc., and alkaline earth metal compounds include calcium, magnesium And alkaline earth metal hydroxides such as barium; oxides; water-soluble salts such as carbonates, acetates, oxalates and phosphates; halides and the like. It is recognized that the addition amount of these metal compounds is preferably 10 to 100 wt% with respect to the activated carbon in the gas adsorption layer.

  In addition, as a flame retardant used in the technology of Patent Document 3, from the need to avoid the coating on the ozonolysis active sites described above, it is a hardly soluble flame retardant, such as aluminum metaphosphate, melamine phosphate, magnesium phosphate, There is a disclosure that one or two or more inorganic flame retardants such as condensed phosphoric acid amides; inorganic flame retardants such as aluminum hydroxide and magnesium hydroxide may be used in combination.

  On the other hand, the present applicant, in Japanese Patent Laid-Open No. 11-57467 (hereinafter referred to as Patent Document 4), is composed of a plurality of laminated units, and this laminated unit is composed of a connecting portion made of hot-melt resin and a resin aggregating portion. A deodorized powder, comprising a deodorized powder granule formed by adhering a deodorized powder granule to one surface of a web through the resin agglomerated part and carrying two or more different types of deodorized powder granule. A multilayer deodorizing filter medium is proposed in which only one type of deodorized powder granule is supported in one laminating unit without using a binder that covers the granule. In this publication technique, for example, a chemical action of capturing odorous substances classified into acidic odor and alkaline odor using their charged state, that is, deodorizing by electrically neutralizing, is different from each other. With regard to a deodorizing filter medium having more than one type of deodorized powder particles, attention is paid to the fact that each deodorized powder particle is liable to be deactivated. Deodorant powder suitable for use in such a technique is not only a granule mainly composed of a chemical deodorant that directly acts on odor, but also a powder having a physical adsorption action such as activated carbon and zeolite. In other words, so-called impregnated charcoal, in which a chemical deodorant is attached to the surface, is described. Furthermore, for a more specific embodiment, as a chemical deodorant constituting the powder for acidic odor, alkali metal carbonates such as potassium carbonate, potassium bicarbonate, sodium carbonate, sodium bicarbonate, ethanolamine, hexamethylenediamine As chemical deodorizers constituting amine compounds such as piperazine and powders for alkaline odor, phosphoric acid, sulfuric acid, nitric acid, malic acid, citric acid, ascorbic acid and the like are disclosed.

  Furthermore, the present applicant, in Japanese Patent Application Laid-Open No. 2004-3070 (hereinafter referred to as Patent Document 5), while maintaining the surface characteristics of the solid particles having various functions effectively, the solid particle-supporting fibers that are uniformly fixed and A technology to provide fiber sheets is proposed. In this publication technique, at least the surface of a fiber mainly composed of a thermoplastic resin is brought into contact with heated solid particles maintained at a temperature higher than the melting point of the thermoplastic resin, and the solid-particle fused fiber is cooled. This includes a mode in which the solid particles are fixed to the fiber surface. As an aspect of such a fiber, there is a disclosure that the thermoplastic resin constituting the surface thereof may be a thermoplastic resin coated and formed as a sheath component on a fiber constituting a predetermined core component.

JP-A-2006-119313 ([Claims], [Background Art], [Best Mode for Carrying Out the Invention]) JP-A-2004-313880 ([Claims], [Embodiments of the Invention]) JP 2000-157827 A ([Claims], [0006] to [0008], [0014], [0022] to [0025]) UL 94 (International Standard Book Number: ISBN1-55989-150-5) JP-A-11-57467 ([Claims], [0003], [0006], [0013]) JP 2004-3070 A ([Claims], [0006], [0012] to [0016])

  As can be understood from the background art described above, a filter medium that uses both a catalytic action and an adsorbing action is known in order to eliminate ozone or VOC generated in the image forming apparatus by decomposing or adsorbing in the apparatus. And for the material responsible for the adsorption action, various chemical substances are added to add a chemical ozone treatment function to materials with a large specific surface area such as activated carbon which has been used mainly for VOC adsorption. The method of attaching has come to be taken. Furthermore, in practice, a proposal for expecting the desired flame retardancy to the filter medium by combining a flame retardant satisfying predetermined characteristics is also recognized. However, according to the conventional technique, even if a flame retardant is applied to the filter medium, the amount of chemical substances attached to the activated carbon must be limited, and as a result, the ozone treatment function cannot be satisfied. It was. For this reason, in the prior art, in order to improve the overall removal performance, a filter mainly focusing on VOC adsorption and a filter mainly focusing on ozonolysis are often separated. However, when two types of filter media are inserted, the pressure loss in the apparatus increases, and the apparatus design may be limited due to its bulk. In addition, the ozonolysis filter is mainly a honeycomb type with a metal oxide attached, but it is expensive and causes a cost increase.

  Therefore, the inventors of the present application combined such various materials, and as a result of extensive studies, found a filter configuration that can remove both VOC and ozone with high efficiency and that does not impair flame retardancy, The present invention has been completed.

  The present invention has been made in view of the above-mentioned problems of the prior art, and therefore, the object of the present invention is excellent in flame retardancy, ozonolysis and VOC removal, and particularly flame retardant applied according to the design. An object of the present invention is to provide a flame retardant ozone VOC removal filter capable of exhibiting excellent characteristics in various electronic devices, air conditioners and the like without impairing the properties.

In order to achieve this object, according to the configuration of the present invention, there is provided a flame retardant ozonolysis filter comprising activated carbon particles containing a flame retardant and having potassium carbonate attached to a cover material made of a fabric. The amount of potassium carbonate mentioned above is 1 to 3% by mass. The “adhesion amount” referred to here represents a value obtained by expressing the ratio of the addition mass of potassium carbonate to the mass of activated carbon before the attachment represented by the following formula as a percentage.
Amount of addition [%] = addition mass of potassium carbonate [g] / active carbon mass before addition [g] × 100
In carrying out the present invention, the cover material and the activated carbon particles described above are bonded via a resin agglomeration portion made of a hot melt resin, and the above-described flame retardant and activated carbon particles impregnated with potassium carbonate are spaced apart. It is preferable that

  Furthermore, it is preferable that the flame retardant described above is contained in a binder attached to the constituent fibers of the cover material described above. In addition, it is preferable that ozonolysis catalyst particles made of a metal oxide are supported on a binder attached to the constituent fibers of the cover material.

  By adopting the above-described configuration of the present invention, it is possible to realize a flame-retardant ozone VOC removal filter that is excellent in ozonolysis and VOC removal performance and that hardly inhibits the desired flame retardancy.

  Hereinafter, the best mode for carrying out the present invention will be described with reference to FIG. 1 showing a flame retardant ozone VOC removal filter as a preferred example in a schematic section, according to an example of its production process. In the figure, components having the same function are indicated by the same reference numerals and hatching, and the cross-sectional configuration and the like of some components are omitted.

  First, as a fabric constituting the cover material, a binder made of a thermoplastic resin containing a flame retardant for imparting desired flame retardancy to an arbitrary suitable breathable material made of nonwoven fabric, knitted fabric or woven fabric. Apply, dry and apply. Thereafter, for example, by applying the technique of Patent Document 5 described above, the ozone decomposition catalyst particles made of a metal oxide are brought into contact with a fabric having a surface made of the thermoplastic resin in a heated state, and the ozone decomposition catalyst The cover material 11 in a state where the particles are supported is produced. The cover material preferably carries ozonolysis catalyst particles (not shown), but the catalyst particles have an ozonolysis function of activated carbon particles to which potassium carbonate, which is an essential component of the present invention, is attached. It is used selectively as a component for assisting.

  Hereinafter, the manufacturing process and the various constituent materials used will be described in detail. As the fabric constituting the cover material described above, the air-permeable material having the various structures described above can be used, but when applied to an air conditioner, of course, when applied to an image forming apparatus, For example, for the purpose of collecting dust such as smoke generated at the time of heat-fixing on toner or a recording material, it can be arbitrarily selected in consideration of a physical filtering action. Further, the flame retardant applied to the present invention may be a fiber kneaded and spun into the fibers constituting such a fabric, but supports the ozone decomposition catalyst particles for effective ozone decomposition. It is desirable to adopt a configuration that employs the technique of Patent Document 5 described above as an aspect to perform.

  If this point is explained in detail, a binder having thermoplasticity at a temperature lower than the melting point or softening point of the fibers constituting the fabric is used as a thermoplastic resin as a base for supporting the heated ozone decomposition catalyst particles. The binder contains a flame retardant having the desired flame retardancy. Examples of such a binder include acrylate resin, SBR resin, NBR resin, urea resin, polyvinyl chloride, and polyvinylidene chloride. Among them, acrylic ester resins not containing halogen, SBR resins, NBR resins, urea resins, and the like are more preferable, and those made of conventionally known thermoplastic resins can be arbitrarily selected and used. good. These binders do not need to be attached to the entire surface of the constituent fibers of the fabric constituting the cover material, but the content of the flame retardant used and the ozone decomposition catalyst required when the technique of Patent Document 5 is adopted. Depending on the filter design, such as the amount of particles deposited, any suitable amount can be achieved.

  Further, for the flame retardant, well-known materials such as various phosphoric flame retardants and inorganic flame retardants disclosed in, for example, the above-mentioned Patent Document 3, can be used. These flame retardants are preferred. In addition, as a configuration of the present invention, since a filter is disposed so that the processing air containing ozone passes in the thickness direction of the cover material 11 described above, a dust collection effect is expected, so that suitable flame retardancy is achieved. As an index of the above, in the horizontal burning test (Horizontal Burning Foamed Material Test: hereinafter, abbreviated as a horizontal combustion test, and a specific test method will be described in detail later) It is desirable that the equivalent evaluation satisfies the criterion of “94HF-1”. Therefore, as a flame retardant satisfying such a standard, aluminum metaphosphate, melamine phosphate, magnesium phosphate, ammonium polyphosphate, aluminum hydroxide, magnesium hydroxide and the like are optimal.

  As the ozonolysis catalyst particles supported for imparting ozone resolution to the cover material in which the binder containing the flame retardant described above is applied to the fabric and dried, the above-mentioned Patent Document 1 and Patent Document 2 are used. However, the catalyst particles themselves are preferably made of a metal oxide having flame retardancy and excellent ozone decomposability, and particularly having a large specific surface area. What consists of manganese dioxide is suitable. In addition, as described above, in configuring the filter of the present invention, a flame retardant can be incorporated into the constituent fibers constituting the cover material without using the binder described above. It is preferable that the surface of the constituent fiber has thermoplasticity to which the technology of Patent Document 5 can be applied.

  Next, the activated carbon particles supported on such a cover material can be prepared by a conventionally known attachment technique, for example, by immersing the activated carbon particles in a potassium carbonate aqueous solution and drying. In the present invention, the amount of potassium carbonate attached to the activated carbon particles supported on the cover material containing a flame retardant is preferably 1 to 3% by mass, more preferably 1 to 2% by mass. This makes it possible to reliably expect flame retardancy even when filter lot variations occur due to variations in the particle size of the activated carbon used or potassium carbonate adhesion irregularities. When the amount of adhering is less than this range, it is difficult to expect ozone resolution, and when the amount of adhering potassium carbonate exceeding this preferred range is used, the flame retardancy of the filter is inhibited. There is.

  Also, commercially available activated carbon particles described above can be arbitrarily selected and supported by various techniques, but for the purpose of suppressing pressure loss in the thickness direction of the cover material on which the particles are supported, It is optimal to adopt the technique of Patent Document 4 described above. As a specific production process, for example, a hot melt such as a thermoplastic polyamide resin, a thermoplastic polyester resin, a thermoplastic urethane resin, a polyolefin resin, or an ethylene-vinyl acetate copolymer resin is applied to the cover material 11 in FIG. In the state where a hot melt nonwoven fabric prepared by a known spinning technique such as a melt blow method is laminated, for example, resin is singly or mixed, and the activated carbon particles 13 after the attachment are sprayed on the laminate. Thereafter, by heating the laminate in this state with dry heat or wet heat, the hot melt resin is plasticized, and a part thereof becomes the connecting portion 15 while leaving the fiber form, and the hot melt nonwoven fabric as the raw material is removed. The relatively thin fiber component that has been configured is melt-cut and aggregated at the contact portion with the activated carbon particles 13 to form the resin aggregation portion 17.

  When the above-described supporting technology is adopted, the arrangement relationship between the cover material 11 containing the flame retardant and the activated carbon particles 13 is a structure that is separated via the resin agglomeration portion 17. For this reason, the potassium carbonate attached to the activated carbon particles 13 and the flame retardant are separated from each other, and even when a flame retardant having hygroscopicity or water solubility is used, the ozone decomposing function for the activated carbon particles is reduced. It has the effect of avoiding the decrease.

  Further, when adopting the specific form of FIG. 1 in which the activated carbon particles 13 are supported in a state of being separated from the cover material 11 via the resin agglomeration part 17, in the heating step for forming the resin agglomeration part 17, Under the material conditions that the ozone decomposition catalyst particles carried on the produced cover material 11 do not fall off, that is, at the temperature corresponding to the melting point or softening point of each of the above-mentioned hot melt resins, it is derived from the binder applied to the cover material. It is necessary to adopt conditions that do not soften the resin component.

  By sequentially performing such a series of steps, in the form of FIG. 1, the two layers made of the activated carbon particles 13 are constituted by the resin agglomeration portion 17 and the connection portion while being sandwiched between the two cover materials 11. A flame retardant ozone VOC removal filter is obtained. In addition, this invention is not limited to such a form, For example, the filter of illustration can be folded in zigzag and it can incorporate in various apparatuses as a unit which attached the frame to the periphery. In the case of the folding process described above, the area of the filter medium can be efficiently improved by folding, and low pressure loss can be achieved even in a copying machine having a relatively high wind speed. Moreover, by forming the surface of the sheet-like filter with the cover material 11 as in the illustrated embodiment, it is possible to prevent the activated carbon particles from falling off during the above-described folding process. Further, in the above-described embodiment, the case where the cover material itself is expected to have a filtering function is exemplified, but various conventionally known filters may be separately laminated on the filter having the main configuration of the present invention. it can.

  Hereinafter, as an example of the present invention, results of test evaluation of a filter manufactured under specific conditions will be described. In the following description, specific shapes, arrangement relationships, and other numerical conditions will be described. However, these conditions are only suitable examples for understanding the present invention, and the present invention is not limited to the contents of these examples. However, the present invention is not limited thereto, and any suitable design changes and modifications can be made within the scope of the object of the present invention.

(Filter production)
First, in this evaluation test, the filter having the structure shown in FIG. 1 described above was manufactured under various material conditions. First, as a binder containing a flame retardant for adhering to the cover material 11, a commercially available phosphorus-based flame retardant liquid (a hardly soluble polyphosphoric acid that can be expected to meet the flame retardancy standard of “HF-1” described above) 37 parts by weight of an aqueous dispersion containing 54% by mass of ammonium as a solid content), 4.4 parts by weight of an acrylic resin emulsion type adhesive (an aqueous dispersion having a solid content of 45% by mass), and a known thickener 0 4 parts by weight and 58.2 parts by weight of water were mixed and prepared.

Next, a wet nonwoven fabric composed of polyolefin fibers having a surface density of 20 g / m ² was impregnated with the binder containing the above-mentioned flame retardant and dried to obtain a cover material serving as a base material having a surface density of 30 g / m ² . This cover material contained 29.7% by mass of a phosphorus-based flame retardant as a solid content in a thermoplastic resin component derived from a binder applied to the fiber surface of a wet nonwoven fabric as a fabric.

In the above-described cover material, commercially available manganese dioxide “CMD-K200” (manufactured by Chuo Denki Kogyo Co., Ltd., trade name: specific surface area 250 g / m ² , average particle diameter 4.8 μm) A cover material 11 of 34 g / m ² was finally prepared.

In addition, an aqueous potassium carbonate solution was added to “Kuraray Coal GW20 / 40” (trade name; particle size range: 0.35 to 0.85 mm, average particle size: 0.61 mm), which is a commercially available activated carbon. The activated carbon particles having various amounts of adhesion (described later) were separately prepared. Thereafter, a spider web-shaped hot melt nonwoven fabric (surface density 20 g / m ² ) made of a thermoplastic polyamide-based hot melt resin (melt index at 190 ° C. is about 80) was laminated on the cover material 11 described above. . In this state, activated carbon particles with various amounts of adhesion are dispersed by the technique of Patent Document 4 described above, steam treatment at about 5 Kg / cm ² is performed for about 7 seconds, and a connection made of hot melt resin is performed. By forming the part 15 and the resin aggregation part 17, the activated carbon particles 13 were fixedly supported on the cover material 11. Subsequently, components other than the fixed activated carbon particles are removed, and by repeating this step, the component having the second layer of activated carbon particles fixed and supported, and a separately prepared filter having the same configuration as described above constituting the other surface of the filter are prepared. By sequentially laminating and adhering the cover material 11, as shown in FIG. 1, a filter having a cross-sectional structure having a symmetrical layer structure in the thickness direction was obtained. Regarding the four types of filters prepared under substantially the same conditions except that the amount of the activated carbon particles added is different, the details of the main components and the potassium carbonate in each activated carbon particle described above are obtained. Table 1 shows the amount of adhesion, the pressure loss in a flat plate state (measured value at a surface wind speed of 0.5 m / sec), the surface density as a filter, and the thickness of the filter (measured value at 20 g / cm ² load). .

(Flame retardancy test evaluation)
Next, the results of the test evaluation of the above-described flame retardancy for each filter sample will be described. As described above, since the filter according to the present invention is preferably used by passing air to be processed in the thickness direction, the filter is evaluated by the horizontal combustion test defined in Non-Patent Document 1. did. In this horizontal combustion test, a supporting wire net that can place a test piece at a predetermined height is used, and absorbent cotton (referred to as labeled cotton) is placed under the wire net at a distance of 175 ± 25 mm. Keep it. This wire net was cut into strips having a length of 150 ± 1 mm and a width of 50 ± 1 mm, and a total of three marked lines were previously written at each of 25 mm, 60 mm and 125 mm from one end in the length direction. Place the specimen. In the combustion test, a flame is applied for 60 ± 1 second from below the wire mesh to the above-described end portion with the test piece placed horizontally, and then the flame is separated from the test piece. Timing from this point,
[A] Time when flame disappeared (residual flame) [b] Time when flame and red heat disappeared (residual dust) [c] Time when flame or red heat front reached 125 mm mark, or test specimen marked 125 mm Record three types of time, the time when combustion or red heat stopped before. According to the results of performing such evaluation tests five times, each flame retardant standard condition is classified and evaluated into two types of “94HF-1” or “94HF-2” as shown in Table 2 below. The

  The horizontal combustion test mentioned above was done about each test piece. As a result, it was confirmed that the filters according to Example 1, Example 2, and Comparative Example 1 were adapted to the standard conditions of “94HF-1” according to the characteristics of the flame retardant used. However, the filter according to Comparative Example 2 was only compatible with “94HF-2”. By combining these results, it can be understood that the effect of the flame retardant is hindered because the amount of potassium carbonate attached to the activated carbon particles was 9 mass%.

  Next, an evaluation method for each performance of ozonolysis and VOC removal will be described for each filter described above.

(Ozone decomposition performance evaluation method)
In this example, the four types of filters described in Table 1 were cut into a 30 mmφ disk shape and set in a cylindrical glass measurement holder. For this measurement holder, an ozone atmosphere was passed for 8 hours continuously with a commercially available ozone generator under the conditions of ozone concentration of 2.7 ppm, surface wind speed on the set filter surface of 17 cm / sec, and relative humidity of 35%. The ozone concentrations on the side and outflow side were measured over time. At this time, the ozone concentration was measured using “MODEL 1200” (trade name, manufactured by Directec Co., Ltd.), and the ozonolysis performance was calculated as the ozone removal rate (%) from Equation 1 below. The ozone removal rate 10 minutes after the start of the test was defined as the initial efficiency.

(VOC removal performance evaluation method)
In this example, based on “DIN 71460-II” as a gas adsorption filter test method, performance evaluation was performed using VOC as toluene. In this performance evaluation, the four types of filters in Table 1 are pleated filters with a folding height of 60 mm, and a well-known frame material has a frontage area; length 56 mm × width 112 mm × height 60 mm, filter medium area per frontage area; 1880 cm ² Units were manufactured under dimensional conditions, and the toluene flow was continued under the conditions of a rated air flow of 1.8 m / sec and a constant inflow side toluene concentration of 80 ppm. Over time, the concentration of toluene on the outflow side of the unit was measured for deodorizing filter gas removal performance. Measured with an apparatus. The performance evaluation of this VOC removal is based on the toluene adsorption capacity up to the breakthrough point where the toluene concentration on the outflow side becomes 95% on the inflow side (when the efficiency drops to 5%) as the value per frontage area. It calculated | required in the unit of (g / m < ² >). Furthermore, in this test, the measured value 1 minute after the start of the test was calculated as the initial efficiency.

  The performance evaluation results of these ozonolysis and VOC removal are shown in Table 3 below. In the table, the evaluation results of the flame retardancy test described above and the amount of potassium carbonate attached are also described.

  As can be understood from Table 3 above, in Example 1 and Example 2 in which the configuration of the present invention was applied and the amount of activated carbon particles applied was made in a predetermined range, “94HF, which is a flame retardance standard condition for a copier filter, is used. It was a filter medium having flame retardancy capable of clearing "-1", having a high ozone decomposing ability and a function of removing volatile organic compounds. Although the comparative example 1 was a filter medium which can clear "94HF-1", its ozonolysis ability was low. Further, Comparative Example 2 was determined to be “94HF-2” indicating that the flame retardance was inhibited due to the large amount of potassium carbonate adhering, and was further inferior in toluene adsorption capacity. From these results, it was confirmed that by adopting the configuration according to the present application, it is possible to realize a filter that is excellent in ozonolysis and VOC removal and that does not impair flame retardancy.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic sectional view for explaining a preferred embodiment of the present invention.

Explanation of symbols

11: Cover material
13: Activated carbon particles (impregnated with potassium carbonate),
15: connecting part (made of hot melt resin),
17: Resin aggregation part (consisting of hot melt resin).

Claims (4)

A flame-retardant ozone VOC removal filter comprising activated carbon particles loaded with potassium carbonate on a cover material comprising a flame retardant and comprising a fabric, wherein the amount of potassium carbonate added is 1 to 3% by mass A flame retardant ozone VOC removal filter characterized by the above. The cover material and the activated carbon particles are bonded via a resin agglomeration portion made of a hot melt resin, and the flame retardant and the activated carbon particles impregnated with the potassium carbonate are spaced apart. The flame-retardant ozone VOC removal filter according to 1. The flame retardant ozone VOC removal filter according to claim 1, wherein the flame retardant is contained in a binder attached to a constituent fiber of the cover material. The flame retardant ozone VOC removal filter according to claim 3, wherein ozone decomposition catalyst particles made of a metal oxide are supported on a binder adhered to the constituent fibers of the cover material.

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