Air filter and method for manufacturing an air filter

Abstract

The present application provides an air filter filter medium, which has a substrate, an enzyme-containing antibacterial material loaded on the substrate, an inorganic anti-allergen material, and a mold inhibitor.

Description

Technical Field

[0001] This invention relates to filter media for air filters and a method for manufacturing filter media for air filters. Background Technology

[0002] Harmful substances such as mites, pollen, and bacteria float in the air. In order to capture and deactivate these airborne harmful substances, air purifiers and ventilation devices are equipped with air filter media (e.g., Patent Document 1 and Patent Document 2).

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2005-7345

[0006] Patent Document 2: Japanese Patent Application Publication No. 2011-206683 Summary of the Invention

[0007] The problem that the invention aims to solve

[0008] However, it is known that if filter media for air filters manufactured according to existing technology is used, there is a risk that the antibacterial properties may be reduced depending on the circumstances.

[0009] The present invention was made in view of the above circumstances, and its object is to provide a filter material for air filters that exhibits excellent antibacterial properties. A further object of the present invention is to provide a method for manufacturing the filter material for air filters.

[0010] means for solving problems

[0011] This invention provides a filter material for an air filter, comprising a substrate, an enzyme-containing antibacterial material, an inorganic antiallergenic material, and a mold inhibitor loaded on the substrate. This invention may also include a colorant loaded on the substrate.

[0012] In addition, the present invention provides a method for manufacturing filter material for air filters, comprising: a first loading step in which a colorant is loaded onto a substrate; and a second loading step in which an enzyme-containing antibacterial material, an inorganic antiallergenic material, and a mold inhibitor are loaded onto a substrate loaded with the colorant.

[0013] In this invention, preferably, the inorganic anti-allergenic material contains at least one selected from the group consisting of inorganic solid acids and inorganic metal salts.

[0014] In this invention, preferably, the colorant contains organic pigments.

[0015] In this invention, preferably, the enzyme contains lysozyme.

[0016] In this invention, preferably, the loading of the anti-allergenic material is less than 3 g / m³. 2 .

[0017] In this invention, preferably, the loading of the anti-allergenic material is 0.05 g / m³. 2 above.

[0018] In this invention, preferably, the ratio of the loading amount of the antiallergenic material to the loading amount of the mold inhibitor (loading amount of antiallergenic material / loading amount of mold inhibitor) is less than 100.

[0019] In this invention, preferably, the mold inhibitor contains at least one selected from the group consisting of iodopropynyl butylcarbamate, polyaminopropyl biguanide, 2-methyl-4-isothiazolin-3-one, and sodium dehydroacetate.

[0020] Invention Effects

[0021] According to the present invention, an air filter material that exhibits excellent antibacterial properties (even under high temperature and high humidity conditions) can be provided. Furthermore, according to the present invention, a method for manufacturing the air filter material can be provided. Attached Figure Description

[0022] Figure 1 It is a graph showing the relationship between the load on the antiallergenic material and its antiallergenicity. Detailed Implementation

[0023] [Air filter media]

[0024] The air filter material of this embodiment includes a substrate, an enzyme-containing antibacterial material loaded on the substrate, an inorganic antiallergenic material, and a mold inhibitor.

[0025] In this embodiment, an inorganic antiallergenic material should be used in conjunction with the enzyme-containing antimicrobial material. According to the inventors' understanding, if an enzyme-containing antimicrobial material and an organic antiallergenic material are used together, the antimicrobial activity is significantly reduced, depending on the circumstances. The reason for this is uncertain, but it is speculated that it may be because the enzyme reacts or interacts with the organic antiallergenic material, causing the enzyme to be decomposed (inactivated) by the organic antiallergenic material.

[0026] (Substrate)

[0027] The substrate material can be either organic or inorganic fibers. Examples of organic fibers include cellulose, polypropylene, polyethylene, polyester, and polyamide fibers. Examples of inorganic fibers include glass, magnesium silicate, silica, alumina, aluminosilicate, and zirconium oxide fibers. The substrate can take the form of nonwoven fabric, filter paper, honeycomb, granules, or mesh, without any particular restrictions.

[0028] The substrate may contain flame retardants. Examples of flame retardants include bromine compounds such as pentabromodiphenyl ether, octabromodiphenyl ether, decabromodiphenyl ether, tetrabromobisphenol A, and hexabromocyclododecane; chlorine compounds; phosphoric acid compounds such as ammonium phosphate, guanidine phosphate, and melamine phosphate; and inorganic flame retardants such as antimony compounds, aluminum hydroxide, and magnesium hydroxide.

[0029] (Antibacterial materials)

[0030] Antibacterial materials can include inorganic compounds that dissolve metal ions such as silver, copper, and zinc; metal particles such as silver, copper, and zinc; iodine compounds; phenols; quaternary ammonium salts; imidazoles; benzoic acids; hydrogen peroxide; cresol; chlorhexidine; chloro[dichlorophenoxy]phenol (Irgasan); aldehydes; sorbic acid and other pharmaceuticals; enzymes; catechins; bamboo extracts; cypress extracts; wasabi extracts; mustard extracts; and other natural ingredient extracts. Among these, enzymes can be used as an essential component due to their bacteriolytic properties.

[0031] Examples of enzymes with preferred lysozyme activity include lysozyme, chitinase, protease, glucose oxidase, glucanase, endo-β-N-acetylglucosidase, and endosomalin. These enzymes can be used alone or in combination of two or more. Additionally, these enzymes can be combined with other materials such as proteins (excluding enzymes), peptides, or polysaccharides that have bactericidal activity. These other materials can be used alone or in combination of two or more.

[0032] Examples of proteins and peptides include protamine, lactoferrin, and polylysine.

[0033] Enzymes, especially lysozymes, effectively glycosylate and covalently bond with polysaccharides, thus exhibiting significant antibacterial effects. Examples of polysaccharides include glucan, dextran, mannan, galactomannan, laminarin, carrageenan, and agarose.

[0034] Examples of enzyme combinations with proteins and peptides include lysozyme and protamine, and lysozyme and lactoferrin. Examples of enzyme combinations with polysaccharides include lysozyme and dextran, and lysozyme and galactomannan.

[0035] (Allergen-resistant materials)

[0036] As an inorganic anti-allergenic material, examples include inorganic solid acids and inorganic metal salts. More specifically, examples include inorganic solid acids such as zirconium phosphate, titanium phosphate, and magnesium silicate; and inorganic metal salts such as zinc salts, zirconium salts, aluminum salts, alkaline earth metal salts, and rare earth salts. Among these, zirconium phosphate with a layered crystalline structure (layered zirconium phosphate) is preferred.

[0037] Furthermore, by combining antibacterial materials with inorganic antiallergenic materials, it is particularly effective in suppressing the decrease in antibacterial activity under high temperature and high humidity conditions. The reason for this is still uncertain, but it is speculated that the interaction between the antibacterial materials and the inorganic antiallergenic materials improves stability and durability.

[0038] (Mold inhibitor)

[0039] Examples of fungal inhibitors include organic iodine compounds, organic nitrogen compounds, organic nitrogen halogen compounds, organic sulfur compounds, organic acid esters, organic iodine imidazole compounds, benzoazole compounds, and pyranone compounds. More specifically, examples of fungal inhibitors include butylcarbamate iodopropynyl ester, polyaminopropyl biguanide, 2-methyl-4-isothiazolin-3-one, and sodium dehydroacetate.

[0040] Furthermore, the combined use of antimicrobial materials and mold inhibitors effectively suppresses the decrease in antimicrobial activity under high temperature and humidity conditions. The rationale is uncertain, but it is speculated that the interaction between the antimicrobial materials and mold inhibitors improves stability and durability.

[0041] (Other materials)

[0042] The substrate can also support materials other than those mentioned above. Examples of such materials include colorants.

[0043] Materials used as colorants include known pigments and dyes. Pigments include organic pigments such as azo, polyazo, anthraquinone, quinacridone, isoindoline, isoindolineone, phthalocyanine, perylene, DPP, and fluorescent pigments; and inorganic pigments such as carbon black, synthetic silica, chromium oxide, iron oxide, titanium oxide, calcined pigments, and zinc sulfide. Dyes include alcohol-soluble dyes, oil-soluble dyes, fluorescent dyes, and photochromic dyes. Among these colorants, organic pigments, oil-soluble dyes, and fluorescent dyes are particularly effective at inactivating lysozymes. Among them, preferred colorants include organic pigments, specifically, organometallic complexes such as metal phthalocyanine pigments, metal naphtholine pigments, metal porphyrin pigments, metal azaporphyrin pigments, bipyridine metal complexes, terpyridine metal complexes, phenanthroline metal complexes, dioctoctanic acid metal complexes, azo metal complexes, and hydroxyquinoline metal complexes.

[0044] (Load capacity of each material)

[0045] The preferred loading of antibacterial material is 0.01–1 g / m³. 2 Therefore, it can maintain its antibacterial properties well. From this point of view, a loading rate of 0.025–0.6 g / m³ is more preferable. 2 More preferably, it is 0.05–0.4 g / m 2 .

[0046] The preferred loading of the anti-allergenic material is less than 3 g / m³. 2 When antiallergenic materials and fungicide inhibitors are used together, there is a risk that the antiallergenic and fungicide properties may be reduced due to their interaction. However, if the loading amount is within the aforementioned range, the antiallergenic and fungicide properties can be maintained better. From this point of view, a loading amount of 2 g / m³ is more preferable. 2 The following is a further preferred value of 1.5 g / m 2 The following is an extremely preferred value: 1 g / m 2 the following.

[0047] In addition, the loading of the anti-allergenic material is preferably 0.05 g / m³. 2 That's all. Therefore, it's possible to maintain anti-allergenic properties better. From this perspective, a loading rate of 0.075 g / m³ is more preferable. 2 The above is further preferably 0.1 g / m 2 above.

[0048] The preferred loading of the mold inhibitor is 0.001–1 g / m³. 2 Therefore, it can maintain good anti-mildew properties. From this point of view, a loading rate of 0.005–0.5 g / m³ is more preferable.2 More preferably, it is 0.01–0.1 g / m 2 .

[0049] The ratio of the loading amount of the antiallergenic material to the loading amount of the mold inhibitor (loading amount of antiallergenic material / loading amount of mold inhibitor) is preferably less than 100. This ensures that both antiallergenic and antifungal properties are well maintained. Furthermore, when using both the mold inhibitor and the antiallergenic material, by keeping the loading ratio less than 100, the antiallergenic properties can be further improved compared to using only the antiallergenic material. The reason for this is not yet certain, but it is speculated that the mold inhibitor may activate the antiallergenic material. From the above perspective, the loading ratio is more preferably 75 or less, and more preferably 50 or less. Moreover, the lower limit of the loading ratio can be set to be greater than 0. The loading amounts of the mold inhibitor and the antiallergenic material can be appropriately adjusted according to the loading ratio.

[0050] As described above, the inventors have discovered that, in the aforementioned air filter media, by combining mold inhibitors and antiallergenic materials, the antiallergenic properties can sometimes be further improved compared to using only the antiallergenic material. This is particularly significant when the loading of the antiallergenic material is relatively low. Specifically, a method for improving antiallergenic properties has been discovered, which is a method for improving the antiallergenic properties of an air filter media comprising a substrate and at least an inorganic antiallergenic material and a mold inhibitor loaded on the substrate, wherein the loading of the antiallergenic material is less than 3 g / m³. 2 This makes the ratio of the above load amounts less than 100.

[0051] The preferred loading of the colorant is 0.01–10 g / m³. 2 Therefore, the substrate can be appropriately colored. From this point of view, a loading amount of 0.03 to 5 g / m² is more preferable. 2 More preferably 0.05~1g / m 2 .

[0052] [Manufacturing method for filter media for air filters]

[0053] Without using colorants, a method for manufacturing air filter media may include, for example, a treatment liquid preparation step in which a treatment liquid containing an antibacterial material including an enzyme, an inorganic antiallergenic material, a mold inhibitor, other materials as needed, and a liquid component is prepared; a contact step in which the prepared treatment liquid is brought into contact with a substrate; and a drying step in which the substrate with the treatment liquid attached is dried.

[0054] In the preparation process of the treatment solution, an enzyme-containing antibacterial material, an inorganic antiallergenic material, and a mold inhibitor are mixed with a liquid component. The liquid component can be an aqueous solution, a non-aqueous component such as an alcohol, acetone, or hexane, or a mixture thereof. However, from the viewpoint of dispersibility of each material, an aqueous solution is preferred. The amount of antibacterial material, etc., added to the liquid component can be appropriately adjusted to achieve the desired loading amount on the substrate.

[0055] In the contact process, methods such as immersion, spraying, and gravure printing are used to bring the obtained treatment solution into contact with the substrate. The method used can be appropriately selected based on the material, thickness, and surface wettability of the substrate.

[0056] In the drying process, the substrate coated with the treatment liquid is dried at 100–140°C to remove the liquid components from the treatment liquid. A multi-drum dryer or similar equipment can be used for drying.

[0057] When using a colorant, a method for manufacturing air filter media includes: a first loading step in which a colorant is loaded onto a substrate; and a second loading step in which an enzyme-containing antibacterial material, an inorganic antiallergenic material, and a mold inhibitor are loaded onto the substrate loaded with the colorant.

[0058] When using a colorant, the colorant and the enzyme-containing antimicrobial material are loaded onto the substrate in separate loading processes. According to the inventors' understanding, when the colorant and the enzyme-containing antimicrobial material are loaded through a single loading process, the antimicrobial activity is significantly reduced under high temperature and high humidity conditions. The reason for this is uncertain, but it is speculated that it is due to a reaction between the colorant and the enzyme during the preparation or drying of the treatment solution, causing the enzyme to be decomposed (inactivated) by the colorant.

[0059] More specifically, the first loading step may include: a first treatment liquid preparation step, in which a first treatment liquid containing a colorant, an adhesive resin, and liquid components is prepared; a first contact step, in which the prepared first treatment liquid is brought into contact with a substrate; and a first drying step, in which the substrate with the first treatment liquid attached is dried. There are no particular limitations on the adhesive resin, and examples include acrylic resin, polyurethane resin, vinyl acetate resin, SBR resin, epoxy resin, and polyvinyl alcohol resin.

[0060] More specifically, the second loading step may include: a second treatment liquid preparation step, in which a second treatment liquid containing an antibacterial material including an enzyme, an inorganic antiallergenic material, a mold inhibitor, other materials as needed, and liquid components is prepared; a second contact step, in which the prepared second treatment liquid is contacted with a substrate loaded with a colorant after the first loading step; and a second drying step, in which the substrate with the second treatment liquid attached is dried.

[0061] In the preparation process of the treatment liquid, the loading material is mixed with the liquid component. The liquid component can be an aqueous component, a non-aqueous component such as an alcohol, acetone, or hexane, or a mixture thereof. However, from the viewpoint of dispersibility of each material, an aqueous component is preferred. The amount of antibacterial material, etc., added to the liquid component can be appropriately adjusted so that the loading on the substrate is the desired amount.

[0062] The contact and drying processes can be performed in the same manner as in the case where no colorant is used.

[0063] Example

[0064] <Experiment 1: Antibacterial Test>

[0065] (Example 1)

[0066] A mixture is prepared by mixing FASTOGEN Green G-58 (manufactured by DIC Corporation) as a colorant (pigment), acrylic adhesive, and water. This mixture is then applied to a substrate with a surface area weight of 200 g / m². 2 The material is immersed in a 1mm thick polyester nonwoven fabric, then subjected to suction dehydration, and dried using a multi-cylinder dryer at 120℃. This yields a colored polyester nonwoven fabric.

[0067] Next, an enzyme antibacterial agent containing 1% by mass of lysozyme as an antibacterial material, a mold inhibitor solution containing 0.02% by mass of iodopropynyl butylcarbamate as a mold inhibitor, zirconium phosphate powder as an inorganic anti-allergenic material, and water were mixed to prepare a mixture. This mixture was then impregnated into the aforementioned colored polyester nonwoven fabric, followed by suction dehydration and drying using a multi-cylinder dryer at 120°C. The resulting filter material was thus obtained.

[0068] The loading rates of each component in the dried filter media are shown in Table 1. The binder loading rate is 5 g / m³. 2 The pigment content is 0.1 g / m 2 Lysozyme concentration: 0.1 g / m³ 2 The concentration of butylcarbamate iodopropynyl ester is 0.01 g / m³.2 Zirconium phosphate is 2 g / m 2 .

[0069] (Comparative Example 1)

[0070] The filter media was obtained in substantially the same manner as in Example 1, except that no mold inhibitor was used.

[0071] (Comparative Example 2)

[0072] The filter material was obtained in substantially the same manner as in Example 1, except that inorganic anti-allergenic materials were not used.

[0073] (Comparative Example 3)

[0074] The filter material was obtained in substantially the same manner as in Example 1, except that uncolored polyester nonwoven fabric was used instead of colored polyester nonwoven fabric, mold inhibitors were not used, and polyvinylphenol (product name: MARUKA LYNCUR M, manufactured by Maruzen Petrochemical Co., Ltd.) as an organic anti-allergenic material was used instead of zirconium phosphate powder as an inorganic anti-allergenic material.

[0075] (Comparative Example 4)

[0076] The filter material was obtained in substantially the same manner as in Example 1, except that polyvinylphenol, an organic anti-allergenic material, was used instead of zirconium phosphate powder, an inorganic anti-allergenic material.

[0077] (Comparative Example 5)

[0078] A mixture was prepared by mixing FASTOGEN Green G-58 (manufactured by DIC Corporation), acrylic adhesive, an enzyme antibacterial agent containing 1% by mass of lysozyme, a mold inhibitor containing 0.02% by mass of iodopropynyl butylcarbamate, zirconium phosphate powder, and water. This mixture was then used to impregnate a substrate with a surface area weight of 200 g / m². 2 The material is then immersed in a 1mm thick polyester nonwoven fabric, followed by suction dehydration and drying using a multi-cylinder dryer at 120℃. This yields the filter material.

[0079] (Refer to Example 1)

[0080] The filter material was obtained in substantially the same manner as in Example 1, except that uncolored polyester nonwoven fabric was used instead of colored polyester nonwoven fabric.

[0081] The following tests were conducted on the air filter media obtained in each example.

[0082] (Antibacterial test)

[0083] As an antibacterial test, the bacterial vapor-liquid drop test method was used. Specifically, an aqueous solution of *M. luteus* cells (concentration: 10) was prepared by culturing, centrifuging, and washing with a cardiac extract medium. 5 ~10 7 CFU / filter). 0.3 mL of the solution was added dropwise to all the required number of filter media for evaluation, and then left to stand naturally in a biosafety cabinet for the specified time (untreated filter media). Afterwards, using a vibratory mixer, the bacteria on the filter media were extracted into phosphate buffer solution. The extracted stock solution and dilution were transferred to Trypto-Soya agar solid medium and incubated at 30°C for 48 hours. Colony counts were measured and viable cell counts were calculated. The bacterial removal rate was also calculated as an indicator of antimicrobial activity. The results (untreated) are shown in Table 1.

[0084] After treating the untreated filter media under specified conditions, the sterilization rate was calculated in the same manner as above. The results are shown in Table 1. Furthermore, for Comparative Examples 3 and 4, the antibacterial activity was insufficient at the untreated state, therefore no environmental alteration experiments were conducted.

[0085] Table 1

[0086]

[0087] <Experiment 2: Allergenicity Test>

[0088] As shown in Table 2, the loading of the inorganic anti-allergenic material was changed. Otherwise, the air filter material was manufactured in the same manner as in Example 1.

[0089] In addition, the loading amount of the inorganic anti-allergenic material was changed as shown in Table 3. Otherwise, the air filter material was manufactured in the same manner as in Comparative Example 1.

[0090] The obtained air filter media were subjected to the following tests. The results are shown in Tables 2 and 3, respectively.

[0091] (Allergenicity test)

[0092] Randomly cut 25cm pieces from the obtained filter media. 2 The area of ​​the filter media was used as a test strip. The test strip was immersed in a 13 ng / ml solution of Cryj1 (a cedar pollen allergen) and then removed. Four hours after removal, the reduction rate of the allergen (Cryj1) adhering to the filter media was determined by enzyme-linked immunosorbent assay (ELISA). The following is a summary of the test method.

[0093] (1) Allergen assay (ELISA method)

[0094] The primary antibody is immobilized in each well of a 96-well microplate to capture the allergen. Subsequently, a pre-labeled secondary antibody is allowed to react, followed by sequential reactions with an enzyme and a substrate. The absorbance of each colored well is measured, and the antigen amount of the sample is determined from the standard curve.

[0095] (2) Reduction rate calculation method

[0096] The allergen concentration of the allergen solution after reacting with the sample is measured, and the reduction rate compared with the concentration of the allergen solution without reacting with the sample is calculated using the following formula.

[0097] Reduction rate (%) = (B - A) / B × 100

[0098] A: Allergen concentration in the allergen solution after reacting with the sample

[0099] B: Allergen concentration in the initial allergen solution

[0100] (Antibacterial test)

[0101] It is carried out in the same manner as in Experiment 1.

[0102] (Mildew-proof test)

[0103] As the mildew-proof test, Test Method A for Plastic Products in Appendix A of JIS 2911 (2010) is adopted. The case where no mildew is confirmed visually and microscopically is judged as qualified, and the case where mildew is confirmed is judged as unqualified.

[0104] Table 2

[0105]

[0106] Table 3

[0107]

[0108] Figure 1 is a graph showing the relationship between the loading amount of the anti-allergenic material and the anti-allergenicity. That is, the graph obtained by graphing the results of Table 2 and Table 3. According to Figure 1 It can be understood that there are differences in the change of anti-allergenicity depending on the presence or absence of the mildew inhibitor. Especially in the region where the loading amount of the anti-allergenic material is small, by using the mildew inhibitor and the anti-allergenic material in combination, the anti-allergenicity can be further improved compared with the case of using only the anti-allergenic material.

[0109] Industrial applicability

[0110] This invention can be effectively used as a filter material for air filters in hospitals, factories (pharmaceuticals, food), cabins, homes, etc., to capture and deactivate airborne bacteria, molds, allergens, etc.

Claims

1. A filter media for an air filter, characterized in that, The air filter media comprises a substrate, an enzyme-containing antibacterial material loaded on the substrate, an inorganic antiallergenic material, and a mold inhibitor. The ratio of the loading amount of the antiallergenic material to the loading amount of the mold inhibitor, i.e., the loading amount of the antiallergenic material / the loading amount of the mold inhibitor, is less than 100. The loading of the antiallergenic material is less than 3 g / m³. 2 .

2. The filter media for air filters according to claim 1, characterized in that, The inorganic anti-allergenic material contains at least one selected from the group consisting of inorganic solid acids and inorganic metal salts.

3. The filter media for air filters according to claim 1 or 2, characterized in that, The enzyme contains lysozyme.

4. The filter media for air filters according to claim 1 or 2, characterized in that, The loading of the antiallergenic material is 0.05 g / m³. 2 above.

5. The filter media for air filters according to claim 1 or 2, characterized in that, The mold inhibitor contains at least one selected from the group consisting of iodopropynyl butylcarbamate, polyaminopropyl biguanide, 2-methyl-4-isothiazolin-3-one, and sodium dehydroacetate.

6. The filter media for an air filter according to claim 1 or 2, characterized in that, The air filter material also includes a colorant loaded onto a substrate.

7. A method for manufacturing filter media for an air filter, characterized in that, The method for manufacturing the filter media for the air filter includes: A first loading step, in which a colorant is loaded onto a substrate; and In the second loading step, an enzyme-containing antibacterial material, an inorganic antiallergenic material, and a mold inhibitor are loaded onto the substrate loaded with a colorant. The ratio of the loading amount of the antiallergenic material to the loading amount of the mold inhibitor, i.e., the loading amount of the antiallergenic material / the loading amount of the mold inhibitor, is less than 100. The loading of the antiallergenic material is less than 3 g / m³. 2 .

8. The manufacturing method according to claim 7, characterized in that, The colorant contains organic pigments.

9. The manufacturing method according to claim 7 or 8, characterized in that, The enzyme contains lysozyme.

10. The manufacturing method according to claim 7 or 8, characterized in that, The loading of the antiallergenic material is 0.05 g / m³. 2 above.

11. The manufacturing method according to claim 7 or 8, characterized in that, The mold inhibitor contains at least one selected from the group consisting of iodopropynyl butylcarbamate, polyaminopropyl biguanide, 2-methyl-4-isothiazolin-3-one, and sodium dehydroacetate.

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