Deodorizing fiber structure, air filter media and air filter

Abstract

To provide a deodorizing fiber structure that is excellent in handling of inorganic particles and uses economic inorganic particles when a bad odor gas component are deodorized, in particular aldehyde such as acetaldehyde is efficiently removed, and inorganic particles are supported on a fiber structure, as well as an air filter medium and an air filter using the same.SOLUTION: Provided is a deodorizing fiber structure in which inorganic particles and a water-soluble amine compound are supported on a fiber structure, wherein the inorganic particles are porous particles and include one or more kinds selected from the group consisting of silicon dioxide, alumina, and titanium dioxide, an average particle diameter of the inorganic particles is 1 to 50 μm, a specific surface area of the inorganic particles is 100 m2 / g or more, a pore volume of the inorganic particles is 0.3 ml / g or more, and the pH of a 10 mass% dispersion liquid of the inorganic particles and water is 6.6 or higher. An air filter medium and an air filter using the deodorizing fiber structure are also provided.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a fiber structure, an air filter medium, and an air filter having deodorizing properties. [Background technology]

[0002] In recent years, due to the health impacts of dust (yellow sand) from the deserts and arid regions of inland East Asia, PM2.5, and pollen from cedar and cypress trees, as well as the spread of viral infectious diseases such as influenza, many living environments have seen the use of air purifiers and air conditioners to purify, regulate temperature, and control humidity indoors, instead of opening windows to ventilate the air. In particular, there is strong market demand for features to improve comfort in indoor spaces such as homes, workplaces, and automobiles, and as air purification devices become more widespread, there is also a demand for various high-performance air filter media to be attached to air purification devices.

[0003] The odorous gas components present in living environments such as homes, workplaces, and automobiles include aldehydes such as formaldehyde and acetaldehyde; amines such as ammonia and trimethylamine; lower fatty acids such as acetic acid and isovaleric acid; mercaptans such as methyl mercaptan; SO2, NO2; and aromatic hydrocarbons such as toluene and xylene.Among these are those classified as one of the 22 specific odorous substances specified in the Offensive Odor Prevention Act, as well as one of the 13 volatile organic compounds (VOCs) for which the Ministry of Health, Labour and Welfare has set concentration guideline values.

[0004] Given these circumstances, there is a growing need for air filter media with deodorizing properties that can quickly reduce the concentration of odorous gas components indoors, protect the health of people and pets, and make indoor spaces more comfortable.

[0005] For example, in order to provide a fiber sheet suitable for an air filter medium that selectively and efficiently removes only aldehydes without using activated carbon or impregnated activated carbon, a fiber sheet characterized by carrying specific inorganic particles and an acid hydrazide on at least the surface of the fiber has been proposed (see Patent Document 1). This proposal specifies a fiber sheet in which at least one type of inorganic particle is zeolite, and the zeolite has an SiO2 / Al2O3 molar ratio of 20 to 300. This fiber sheet has good aldehyde removal ability, but when carrying zeolite on the fiber sheet by impregnation coating or the like, it can be difficult to handle compared to other inorganic particles, and compared to silicon dioxide, alumina, and titanium dioxide, the material cost is generally high, making it less desirable from an economical standpoint.

[0006] Furthermore, with the objective of providing a deodorizing fiber structure that efficiently removes aldehydes and has an extremely low risk of secondary odor generation, the following are provided: (1) a deodorizing fiber structure comprising a fiber structure carrying inorganic particles and a water-soluble amine compound, the fiber structure having an equilibrium moisture regain of 15% by mass or less in an environment adjusted to a temperature of 25°C and a relative humidity of 75%, and a pH of 3.5 to 7 when immersed in water to a concentration of 3% by mass; (2) the deodorizing fiber structure according to (1), in which the inorganic particles have an equilibrium moisture regain of 10% by mass or less in an environment adjusted to a temperature of 25°C and a relative humidity of 75%; (3) the deodorizing fiber structure according to (1) or (2), in which the inorganic particles are hydrophobic porous particles; and (4) the deodorizing fiber structure according to (3), in which the hydrophobic porous particles have an average pore diameter of 2 to 50 nm. (5) The inorganic particles and the water-soluble amine compound form pores on the surface of the fiber, and the volume of pores with a pore diameter of 20 nm or less accounts for 40% or less of the total pore volume, and the specific surface area is 1 to 30 m 2 (6) The inorganic particles have a number average particle size of 1 μm or less and a specific surface area measured by the BET method of 15 to 250 m / g. 2 / g. (7) The deodorizing fiber structure according to any one of (1) to (5) above, wherein the inorganic particles contain at least one selected from the group consisting of silicon dioxide, alumina, and titanium dioxide. (8) The deodorizing fiber structure according to any one of (1) to (7) above, wherein the water-soluble amine compound contains an acid hydrazide compound. (9) The deodorizing fiber structure according to any one of (1) to (8) above, wherein a poorly water-soluble pH adjuster is contained. (10) The deodorizing fiber structure according to (9) above, wherein the poorly water-soluble pH adjuster is a flame retardant. (11) The deodorizing fiber structure according to any one of (1) to (10) above, wherein the inorganic particles and the water-soluble amine compound are supported on the fiber surface by a binder. (12) The deodorizing fiber structure according to any one of (1) to (10), wherein the inorganic particles have a number-average particle size of 50 to 2000 μm, and the water-soluble amine compound is attached to the inorganic particles and sandwiched between the fibers. (13) An air filter characterized by being constructed using the deodorizing fiber structure according to any one of (1) to (12) has been proposed (see Patent Document 2). However, when the number-average particle size of the inorganic particles is 1 μm or less, the inorganic particles are distributed evenly on the fiber sheet, filling the voids in the fiber structure, which can increase the pressure loss of the air filter, make it difficult to obtain a sufficient dust retention capacity, and cause difficulties in handling the inorganic particles, such as the generation of a lot of dust when preparing a fiber structure carrying the inorganic particles. The dust retention capacity is measured in accordance with JIS D1612, where test powder is introduced at a test air velocity of 2.7 m / sec, the test is stopped when the pressure loss reaches 200 Pa, and the dust retention capacity at that stage is measured; the higher the value, the better the dust collection ability.

[0007] In order to provide a filter medium with excellent VOC adsorption performance, a filter medium has been proposed that includes a nonwoven fabric carrying an adsorbent, which is a particle having an average particle diameter of 1 μm or less, supported by a binder, and the weight ratio of the adsorbent to the binder in the filter medium is within the range of 93% by mass:7% by mass to 99.5% by mass:0.5% by mass (see Patent Document 3). Air filter mediums in which an adsorbent is supported on a fiber sheet to deodorize specific gases are widely known, but when the adsorbent is a particle having an average particle diameter of 1 μm or less, the adsorbent particles are evenly distributed on the nonwoven fabric, filling the voids in the nonwoven fabric, which can increase the pressure loss of the filter medium, make it difficult to obtain sufficient dust retention, or cause a lot of dust flying when producing a nonwoven fabric carrying the adsorbent particles, which can make handling of the adsorbent difficult, and is therefore undesirable. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] Japanese Patent Application Laid-Open No. 2007-167632 [Patent Document 2] Patent No. 5428857 [Patent Document 3] Japanese Patent Application Laid-Open No. 2015-157250 Summary of the Invention [Problem to be solved by the invention]

[0009] The object of the present invention is to provide a deodorizing fiber structure using inorganic particles that efficiently deodorizes malodorous gas components, particularly aldehydes such as acetaldehyde, and that allows the inorganic particles to be easily handled and is economical when supported on the fiber structure, as well as an air filter medium and an air filter that use the same. [Means for solving the problem]

[0010] The object of the present invention can be achieved by the following means. (1) A deodorizing fiber structure comprising inorganic particles and a water-soluble amine compound supported on the fiber structure, the inorganic particles being porous particles and comprising one or more types of inorganic particles selected from the group consisting of silicon dioxide, alumina, and titanium dioxide, the inorganic particles having an average particle size of 1 to 50 μm, and a specific surface area of ​​100 m 2 / g or more, the pore volume of the inorganic particles is 0.3 ml / g or more, and a 10 mass % dispersion of the inorganic particles in water has a pH of 6.6 or more. (2) An air filter medium using the deodorizing fiber structure described in (1) above. (3) An air filter using the deodorizing fiber structure described in (1) above. [Effects of the Invention]

[0011] The present invention provides a deodorizing fiber structure that has good deodorizing performance for aldehydes such as acetaldehyde and allows easy handling of inorganic particles when the inorganic particles are supported on the fiber structure, as well as an air filter medium and an air filter that use the same. DETAILED DESCRIPTION OF THE INVENTION

[0012] The deodorizing fiber structure, air filter medium, and air filter of the present invention will be described in detail below.

[0013] The deodorizing fiber structure of the present invention is a deodorizing fiber structure in which inorganic particles and a water-soluble amine compound are supported on a fiber structure, and the air filter medium is a filter medium used in an air filter, and is a filter medium that uses the deodorizing fiber structure of the present invention.

[0014] The inorganic particles in the present invention are porous particles and are one or more inorganic particles selected from the group consisting of silicon dioxide, alumina, and titanium dioxide. Among these, silicon dioxide is preferred.

[0015] From the viewpoint of deodorizing performance and ease of handling, the average particle size of the inorganic particles is 1 to 50 μm, more preferably 2 to 40 μm, and even more preferably 3 to 30 μm. If the average particle size is less than 1 μm, the voids between the fibers of the fiber structure are filled with small particles, resulting in high pressure loss and insufficient dust retention. Furthermore, handling of the inorganic particles is difficult, as more dusting occurs. If the average particle size is more than 50 μm, the adhesion area between the fibers of the deodorizing fiber structure and the inorganic particles decreases, requiring an excessive amount of binder, which increases the area of ​​the inorganic particle surface covered with the binder, and may result in insufficient deodorizing performance.

[0016] The dust retention capacity is determined by performing a dust test (for example, JIS D 1612-1989 "Automotive Air Cleaner Test Method") on a sample of air filter media or air filter under certain conditions, and when the pressure loss of the sample reaches a certain level, the mass of test dust accumulated on the air filter media or air filter is calculated from the increase in sample mass, and the mass per unit area of ​​the air filter media or air filter is calculated. The higher the dust retention capacity value, the better the dust collection performance and lifespan of the air filter media or air filter.

[0017] From the perspective of deodorizing performance, the specific surface area of ​​inorganic particles is 100m 2 / g or more, and more preferably 120m 2 / g or more, more preferably 140m 2 / g or more. The specific surface area is 100m 2 If the specific surface area is less than 500 m / g, the deodorizing performance of the deodorizing fiber structure will be reduced, which is not preferred. 2 / g or less, more preferably 450m 2 / g or less, and more preferably 400m 2 / g or less. 2 / g, the average particle size often falls below 1 μm, which reduces the adhesion area between the fibers of the deodorizing fiber structure and the inorganic particles. As a result, an excess of the binder that is preferably used to support the inorganic particles is required, which increases the area of ​​the inorganic particle surface that is covered with the binder, and the deodorizing performance may not be fully achieved.

[0018] From the viewpoint of deodorizing performance, the pore volume of the inorganic particles is 0.3 ml / g or more, more preferably 0.4 ml / g or more, and even more preferably 0.5 ml / g or more. If the pore volume is less than 0.3 ml / g, the deodorizing performance of the inorganic particles and the water-soluble amine compound against aldehydes becomes insufficient, which is undesirable. The pore volume is preferably 4.0 ml / g or less, more preferably 3.5 ml / g or less, and even more preferably 3.0 ml / g or less. If the pore volume is more than 4 ml / g, the cost may be high, which may be disadvantageous from an economic standpoint, or the inorganic particles may be difficult to obtain.

[0019] The inorganic particles preferably have an average pore size of 0.08 nm or more. If the pore size is smaller than 0.08 nm, the deodorizing performance of the inorganic particles and the water-soluble amine compound against aldehydes may be insufficient.

[0020] To ensure the deodorizing performance of aldehydes, the pH of a 10% by mass dispersion of inorganic particles and water is 6.6 or higher. The pH is preferably 9.5 or lower. If the pH is lower than 6.6, the deodorizing performance of the inorganic particles and the water-soluble amine compound against aldehydes may be reduced. If the pH is higher than 9.5, the deodorizing performance of aldehydes may also be reduced.

[0021] Examples of the water-soluble amine compound include hydrazines, acid dihydrazides, aliphatic amines, aromatic amines, ureas, amino acids, etc. From the viewpoint of deodorizing performance of aldehydes, acid dihydrazides are more preferred as the water-soluble amine compound.

[0022] Examples of acid dihydrazides include carbodihydrazide, adipic acid dihydrazide, sebacic acid dihydrazide, dodecanediohydrazide, isophthalic acid dihydrazide, salicylic acid dihydrazide, succinic acid dihydrazide, and glutamic acid dihydrazide.

[0023] The amount of the water-soluble amine compound supported on the fiber structure is not particularly limited, but is preferably 3% by mass or more and 100% by mass or less relative to the mass of the inorganic particles. If the amount supported is less than 3% by mass, the deodorizing performance may be poor, and if the amount supported is more than 100% by mass, the deodorizing performance may reach a plateau.

[0024] Materials for the fiber structure of the present invention include synthetic fibers such as polyamide fibers, polyester fibers, polyalkylene paraoxybenzoate fibers, polyurethane fibers, polyvinyl alcohol fibers, polyvinylidene chloride fibers, polyvinyl chloride fibers, polyacrylonitrile fibers, polyolefin fibers, and phenolic fibers; inorganic fibers such as glass fibers, metal fibers, alumina fibers, carbon fibers, and activated carbon fibers; natural fibers such as wood pulp, bamboo pulp, hemp pulp, kenaf pulp, straw pulp, bagasse pulp, cotton linter pulp, cotton, wool, and silk; recycled pulp from waste paper; regenerated cellulose fibers such as rayon and cupra; and regenerated fibers made from proteins such as collagen, and polysaccharides such as alginic acid, chitin, chitosan, and starch. These fibers may also be modified to have properties such as hydrophilicity or flame retardancy. These fibers may be used in combination of one or more types.

[0025] The fiber structure of the present invention is not particularly limited and can be produced, depending on the purpose and use, by a method in which strength is imparted to a web obtained by a dry method, wet paper-making method, meltblown method, spunbonding method, flash spinning method, airlaid method, electrospinning method, etc., by a physical method such as hydroentangling method, needle punching method, stitchbonding method, thermal bonding method such as thermal bonding method, or chemical bonding method using an adhesive such as resin bonding. The fiber structure may be single-layered or multi-layered. In the case of a multi-layered structure, the methods for producing the webs of each layer may be the same or different.

[0026] The basis weight of the fiber structure is not particularly limited, but is preferably 30 to 150 g / m 2 The basis weight of the fiber structure is preferably 30 g / m 2 If the basis weight is less than 150 g / m, the inorganic particles cannot be sufficiently supported, and the deodorizing performance may be too low. 2 If it exceeds this, the pressure loss may become too high.

[0027] The deodorizing fiber structure of the present invention can be produced by supporting inorganic particles and a water-soluble amine compound, which are deodorizing agents, on a fiber structure. When supporting the inorganic particles and a water-soluble amine compound, it is preferable to use a binder.

[0028] The binder is not particularly limited and can be widely used, but a water-soluble or water-dispersible aqueous binder is preferred. Examples of water-soluble binders include polyvinyl alcohol and starch. Examples of water-dispersible binders include poly(meth)acrylic acid esters, polyvinyl acetate, polyvinyl chloride, styrene-acrylic resin, vinyl chloride-acrylic resin, silicone resin, and styrene-butadiene resin.

[0029] The amount of binder added is not particularly limited, but is preferably 5 to 40 mass % based on the solid mass of the total amount of inorganic particles and water-soluble amine compound supported. When the binder content is 5 to 40 mass %, the amounts of inorganic particles and water-soluble amine compound supported are stable, and it is easier to achieve both high deodorizing performance and low pressure loss.

[0030] The method for supporting inorganic particles and a water-soluble amine compound on a fiber structure is not particularly limited as long as it can adhere the inorganic particles and the water-soluble amine compound to the fiber structure as uniformly as possible. Examples of methods include applying a coating liquid containing a dispersion of inorganic particles and a water-soluble amine compound, and optionally a binder, to a fiber structure by a coating or printing method such as screen printing, roll coating, spraying, dipping, curtain coating, bar coating, air knife printing, hot melt coating, gravure coating, brush coating, or offset printing, and then removing the dispersion medium by drying or the like to support the inorganic particles and the water-soluble amine compound. Water is preferably used as the dispersion medium.

[0031] In the present invention, the total amount of the inorganic particles, the water-soluble amine compound, and optionally the binder, which is supported as a solid content, is not particularly limited, but is preferably 1 to 50 g / m 2 based on the fiber structure. 2 It is preferable that the amount of the solid content is 1 g / m 2 If the solid content is less than 50 g / m, the deodorizing performance may be too low. 2 If the amount exceeds 1000 mg / m, the deodorizing performance will reach a plateau and it may not be economically viable. A more preferable amount of solid content supported is 2 to 20 g / m 2 is.

[0032] If necessary, various functions such as antibacterial, antifungal, antiviral, insect repellent, insecticidal, deodorizing, fragrance, temperature-sensing, heat-retaining, heat-storing, heat-generating, heat-absorbing, waterproof, water-resistant, water-repellent, hydrophobic, hydrophilic, dehumidifying, humidity-regulating, moisture-absorbing, oil-repellent, lipophilic, adsorption of oil and the like, and evaporation or sustained release of water, volatile chemicals and the like can be added to the fiber structure for the purpose of adding other performance without departing from the spirit of the present invention.

[0033] The deodorizing fiber structure of the present invention, either alone or after being bonded with other fiber structures, can be attached as an air filter medium or air filter to an air treatment device that uses forced air intake and exhaust by machines such as air conditioners, air purifiers, vacuum cleaners, dehumidifiers, dryers, humidifiers, ventilation fans, electric fans, heat exchangers, etc., to provide a favorable effect in deodorizing malodorous gases in indoor spaces. Alternatively, the air filter medium of the present invention can be used in an outside air inlet (such as an air vent or window) for natural air intake and exhaust. [Example]

[0034] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples. In the examples, "%" and "parts" refer to "quantity" unless otherwise specified. "Volume %" and "Parts by mass" are shown.

[0035] [Average particle size] The average particle size of the inorganic particles was measured using a laser diffraction / scattering particle distribution measuring device LA-950S2 manufactured by Horiba, Ltd.

[0036] [Specific surface area] The specific surface area of ​​inorganic particles was measured as the BET specific surface area using a SORPTOMATIC 1900 manufactured by Carlo Erba. The BET method is a gas adsorption method in which gas molecules such as nitrogen (N2) are adsorbed onto solid particles and the surface area is measured from the amount adsorbed. Specifically, the specific surface area can be calculated by measuring the monomolecular adsorption amount VM using the BET equation (Brunauer, Emmet and Teller's equation) based on the relationship between pressure P and adsorption amount V.

[0037] [Pore volume] The pore volume of the inorganic particles was measured using an AUTOPORE II 9220 manufactured by Micromeritics.

[0038] [pH of inorganic particle dispersion] The pH of the inorganic particle dispersion was measured in accordance with the pH value - room temperature extraction method of the pigment testing method of JIS K 5101-17-2:2004.

[0039] Example 1 In 20g of pure water, inorganic particles with an average particle diameter of 7μm and a specific surface area of ​​150m 2 A coating solution was prepared by blending 12 g of silicon dioxide (Mizusawa Chemical Industry Co., Ltd., trade name: Mizukasil (registered trademark) P-526) with a pore volume of 0.6 ml / g and a pH of 7.0 for the inorganic particle dispersion, 3 g of adipic acid dihydrazide (a reagent manufactured by Tokyo Chemical Industry Co., Ltd.) as a water-soluble amine compound, and 7 g of an acrylic resin emulsion binder as a solid content, followed by mixing and stirring. A polyester spunbond nonwoven fabric (basis weight 50 g / m) was used as the fiber structure. 2 The coating solution was applied to a fiber structure (0.5 mm thick) by impregnation while controlling the amount of solids carried, and then dried at 120°C to produce a deodorizing fiber structure. The total amount of solids carried by the fiber structure, including the inorganic particles, water-soluble amine compound, and binder, was 20 g / m 2 It was.

[0040] Example 2 Inorganic particles with an average particle diameter of 2 μm and a specific surface area of ​​300 m 2 A deodorizing fiber structure was produced in the same manner as in Example 1, except that alumina (manufactured by Nippon Light Metal Co., Ltd., product name: AxSorb AA-101) with a molecular weight of 0.01g / g, a pore volume of 0.44ml / g, and a pH of 7.0 for the inorganic particle dispersion was used. The total solids loading of the inorganic particles, water-soluble amine compound, and binder on the fiber structure was 20g / m 2 It was.

[0041] Example 3 A deodorizing fiber structure was produced in the same manner as in Example 1, except that sebacate dihydrazide (a reagent manufactured by Tokyo Chemical Industry Co., Ltd.) was used as the water-soluble amine compound. The total solid content of the inorganic particles, water-soluble amine compound, and binder on the fiber structure was 20 g / m 2 It was.

[0042] Example 4 As inorganic particles, the average particle diameter is 6.6 μm and the specific surface area is 290 m 2 A deodorizing fiber structure was prepared in the same manner as in Example 1, except that silicon dioxide (trade name: Finesil X-60, manufactured by Maruo Calcium Co., Ltd.) having a molecular weight of 1.0 g / g, a pore volume of 1.4 ml / g, and a pH of 6.7 in the inorganic particle dispersion was used. The total solids loading of the inorganic particles, water-soluble amine compound, and binder on the fiber structure was 20 g / m. 2 It was.

[0043] Example 5 As inorganic particles, the average particle diameter is 2.4 μm and the specific surface area is 300 m 2 A deodorizing fiber structure was prepared in the same manner as in Example 1, except that silicon dioxide (manufactured by Tosoh Silica Corporation, product name: NIPGEL (registered trademark) AZ-200) was used, which had a molecular weight of 1.0g / g, a pore volume of 2.0ml / g, and a pH of 7.0 for the inorganic particle dispersion. The total solids loading of the inorganic particles, water-soluble amine compound, and binder on the fiber structure was 20g / m. 2 It was.

[0044] Example 6 20 parts by mass of titanium tetraisopropoxide (manufactured by Kojundo Chemical Laboratory, product name: Tetra-i-propoxytitanium) as a titanium dioxide precursor was added to 50.7 parts by mass of distilled water and 49.3 parts by mass of normal propanol and stirred for 2 hours. After stirring, the mixture was placed in a 200 ml fluororesin pressure vessel and left in a thermostatic chamber set to 100°C for 24 hours for hydrothermal treatment. The pressure vessel was then removed and allowed to cool. The reaction product in the pressure vessel was separated by suction filtration, dried for 6 hours in a dryer set to 80°C, and pulverized using a pulverizer to obtain a powder of titanium dioxide 1. The resulting titanium dioxide 1 had an average particle size of 15 μm and a specific surface area of ​​230 m. 2 / g, the pore volume was 0.33 ml / g, and the pH of the dispersion of titanium dioxide 1 was 6.9.

[0045] A deodorizing fiber structure was produced in the same manner as in Example 1, except that titanium dioxide 1 was used as the inorganic particles. The total solid content of the inorganic particles, water-soluble amine compound, and binder in the fiber structure was 20 g / m 2 It was.

[0046] Example 7 As inorganic particles, the average particle diameter is 50 μm and the specific surface area is 230 m 2 A deodorizing fiber structure was prepared in the same manner as in Example 1, except that silicon dioxide having a molecular weight of 0.6g / g, a pore volume of 0.6ml / g, and a pH of 7.4 in the inorganic particle dispersion was used. The total solids adhesion amount of the inorganic particles, water-soluble amine compound, and binder to the fiber structure was 20g / m 2 It was.

[0047] Example 8 Inorganic particles with an average particle diameter of 3 μm and a specific surface area of ​​100 m 2 A deodorizing fiber structure was prepared in the same manner as in Example 1, except that silicon dioxide having a pore volume of 0.4 ml / g, a pH of 7.2 in the inorganic particle dispersion was used. The total solids adhesion amount of the inorganic particles, water-soluble amine compound, and binder to the fiber structure was 20 g / m 2 It was.

[0048] Example 9 Inorganic particles with an average particle diameter of 5 μm and a specific surface area of ​​200 m 2 A deodorizing fiber structure was prepared in the same manner as in Example 1, except that silicon dioxide having a pore volume of 0.3 ml / g, a pH of 7.2 in the inorganic particle dispersion was used. The total solids adhesion amount of the inorganic particles, water-soluble amine compound, and binder to the fiber structure was 20 g / m 2 It was.

[0049] (Comparative Example 1) As inorganic particles, the average particle diameter is 2 μm and the specific surface area is 260 m 2A deodorizing fiber structure was prepared in the same manner as in Example 1, except that silicon dioxide (manufactured by EVONIK GmbH, Germany, product name: Carplex (registered trademark) FPS-101) having a surface area of ​​0.15 m / g, a pore volume of 0.89 ml / g, and a pH of 6.5 for the inorganic particle dispersion was used. The total solids loading of the inorganic particles, water-soluble amine compound, and binder on the fiber structure was 20 g / m. 2 It was.

[0050] (Comparative Example 2) As inorganic particles, the average particle diameter is 2 μm and the specific surface area is 55 m 2 A deodorizing fiber structure was produced in the same manner as in Example 1, except that silicon dioxide (manufactured by Mizusawa Industrial Chemicals, trade name: Mizukasil (registered trademark) P-527) having a molecular weight of 0.1g / g, a pore volume of 0.1ml / g, and a pH of 6.5 in the inorganic particle dispersion was used. The total solids loading of the inorganic particles, water-soluble amine compound, and binder on the fiber structure was 20g / m. 2 It was.

[0051] (Comparative Example 3) As inorganic particles, the average particle diameter is 105 μm and the specific surface area is 180 m 2 A deodorizing fiber structure was prepared in the same manner as in Example 1, except that silicon dioxide having a pore volume of 1.7 ml / g, a pH of 7.6 in the inorganic particle dispersion was used. The total solids adhesion amount of the inorganic particles, water-soluble amine compound, and binder to the fiber structure was 20 g / m 2 It was.

[0052] Comparative Example 4 As inorganic particles, the average particle size is 0.7 μm and the specific surface area is 250 m 2 A deodorizing fiber structure was produced in the same manner as in Example 1, except that silicon dioxide (manufactured by Nissan Chemical Industries, Ltd., trade name: Lightstar (registered trademark)) having a molecular weight of 1.0 g / g, a pore volume of 1.0 ml / g, and a pH of 7.0 in the inorganic particle dispersion was used. The total solids adhesion amount of the inorganic particles, water-soluble amine compound, and binder to the fiber structure was 20 g / m 2 It was.

[0053] (Comparative Example 5) Inorganic particles with an average particle size of 4 μm and a specific surface area of ​​600 m 2 A deodorizing fiber structure was produced in the same manner as in Example 1, except that a zeolite (manufactured by Tosoh Corporation, product name: Zeolite HSZ385HUA) having a molecular weight of 0.1 / g, a pore volume of 0.42 ml / g, and a pH of 7.3 in the inorganic particle dispersion was used. After the inorganic particles, water-soluble amine compound, and binder were applied to the fiber structure, the solid content of the fiber structure was 20 g / m 2 It was.

[0054] [Acetaldehyde deodorizing performance test] The prepared deodorizing fiber structures were cut into 5 cm x 5 cm pieces as air filter media samples and tested individually. The samples were placed in 10-liter odor bags and sealed, and 10 liters of 10 ppm acetaldehyde gas was injected. The acetaldehyde concentration in the odor bags after 30 minutes was measured using a gas detector tube. The acetaldehyde concentration in the odor bags after 30 minutes was evaluated on a three-point scale: "◎: 0 ppm or more but less than 1.5 ppm," "◯: 1.5 ppm or more but less than 3 ppm," and "×: 3 ppm or more." In the present invention, ◎ and ○ are the targets of the invention. A ◎ rating is preferable, as it can be said that the acetaldehyde deodorizing performance is better.

[0055] The evaluation results are shown in Table 1.

[0056] [Table 1]

[0057] As can be seen from Table 1, Examples 1 to 9 are deodorizing fiber structures using inorganic particles whose average particle diameter, specific surface area, pore volume, and pH of the inorganic particle dispersion are all specified properties of the present invention, and all of them had good acetaldehyde deodorizing performance.

[0058] However, the deodorizing fiber structure of Comparative Example 1, which used inorganic particles with a pH of less than 6.6 in the dispersion of inorganic particles, and the deodorizing fiber structure of Comparative Example 2, which used inorganic particles with a pH of less than 6.6 in the dispersion of inorganic particles and a specific surface area of ​​100 m 2The deodorizing fiber structure of Comparative Example 2, which used inorganic particles with a pore volume of less than 0.3 ml / g and a mean particle size of less than 1 μm, had poor acetaldehyde deodorizing performance. On the other hand, the deodorizing fiber structure of Comparative Example 4, which used inorganic particles with an average particle size of less than 1 μm, had good acetaldehyde deodorizing performance, but generated a lot of dust when handling the inorganic particles, which caused problems during the production of filter media and was undesirable. Furthermore, the deodorizing fiber structure of Comparative Example 3, which used inorganic particles with an average particle size of more than 50 μm, had a large average particle size of the inorganic particles, making it difficult to control the amount of solids carried when impregnating and coating the coating liquid, and therefore was undesirable because the deodorizing fiber structure could not be stably produced. Furthermore, the zeolite used in Comparative Example 5 is an inorganic particle that satisfies the specified physical properties of the present invention in terms of average particle diameter, specific surface area, pore volume, and pH of the inorganic particle dispersion, and the deodorizing fiber structure of Comparative Example 5 is a deodorizing fiber structure that uses this zeolite.However, compared to silicon dioxide, alumina, and titanium dioxide, the material cost is generally high and it is not very preferable from an economic standpoint.

[0059] From the above results, it can be seen that the deodorizing fiber structure of the present invention has good deodorizing performance for aldehydes such as acetaldehyde, and uses inorganic particles that are easy to handle when supporting the inorganic particles on the fiber structure, making them economical. [Industrial Applicability]

[0060] The deodorizing fiber structure of the present invention can be used as an air filter for air conditioners and air purifiers used in buildings, factories, automobiles, ordinary homes, etc.

Claims

1. A deodorizing fiber structure comprising inorganic particles and a water-soluble amine compound supported on the fiber structure, wherein the inorganic particles are porous particles and are one or more types of inorganic particles selected from the group consisting of silicon dioxide, alumina, and titanium dioxide, and the inorganic particles have an average particle size of 1 to 50 μm and a specific surface area of ​​100 m ２ / g or more, the pore volume of the inorganic particles is 0.3 ml / g or more, and a 10% by mass dispersion of the inorganic particles in water has a pH of 6.6 or more.

2. An air filter medium using the deodorizing fiber structure according to claim 1.

3. An air filter using the deodorizing fiber structure according to claim 1.

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