Deodorant material and its manufacturing method, and manufacturing method of coating liquid for deodorant layer

Abstract

To provide a deodorizing material and a method for manufacturing the same, while using activated carbon, which is effective against many odor gas components but does not have the effect of removing aldehyde, that also has an excellent aldehyde removal effect, and to provide a method for manufacturing coating liquid for deodorizer layer.SOLUTION: Provided is a deodorizing material 1 that includes a support 10 and a deodorizer layer 20 fixed to the support 10, and in which, characterized, the deodorizer layer 20 contains activated carbon, a functional material made of at least one of silica gel and zeolite, acid hydrazide, aminotriazole, and a binder.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a deodorizing material, a method for producing the same, and a method for producing a coating liquid for a deodorizing agent layer. [Background technology]

[0002] In recent years, due to changes in living environments and growing health consciousness, air conditioning equipment such as air conditioners, air purifiers, humidifiers, and dehumidifiers are widely used in various living spaces such as homes, offices, factories, and automobiles. These air conditioning equipment use various air filters to obtain purified air.

[0003] Air filters are required to remove malodorous gases present in living spaces such as homes, offices, factories, automobiles, etc. Components of malodorous gases include lower aldehydes such as formaldehyde and acetaldehyde, ammonia, amines such as 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. In particular, acetaldehyde falls under both the 22 types of specific odorous substances designated in the Offensive Odor Prevention Act and the 13 types of volatile organic compounds (VOCs) for which the Ministry of Health, Labour and Welfare has set concentration guideline values.

[0004] Activated carbon, which is generally used as a deodorizing agent, is effective against many odorous gas components, but has difficulty in adsorbing aldehydes (Patent Document 1). It is known that acid hydrazides are effective in removing aldehydes (Patent Document 2). However, acid hydrazides are almost ineffective against odorous gases other than aldehydes.

[0005] Therefore, it is considered to use activated carbon in combination with acid hydrazide, but it is known that when used in combination, activated carbon acts as a catalyst to oxidize the functional group (amine group) of the acid hydrazide, resulting in a decrease in performance against aldehydes (Non-Patent Document 1). The deodorizing material is obtained by applying a slurry containing a deodorizing agent to a support and drying the applied slurry. Activated carbon as a deodorizing agent must be dried so that the water inside the activated carbon is sufficiently removed. However, if the activated carbon is dried at a high temperature in consideration of production efficiency, the performance of the coexisting acid hydrazide will be significantly reduced.

[0006] Aminotriazole is also known to be effective in removing acetaldehyde (Patent Document 3). Therefore, it is conceivable to use activated carbon in combination with aminotriazole, but aminotriazole has a slower adsorption speed than acid hydrazide. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Japanese Patent Application Laid-Open No. 2010-58075 [Patent Document 2] International Publication No. 2009 / 122975 [Patent Document 3] Japanese Patent Application Laid-Open No. 2004-2523 [Non-patent literature]

[0008] [Non-Patent Document 1] Journal of Chemical Engineering, 2006, Vol. 32, No. 1, pp. 72-78 Summary of the Invention [Problem to be solved by the invention]

[0009] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a deodorizing material that is effective in removing aldehydes while using activated carbon that is effective against many odorous gas components but does not have the effect of removing aldehydes, a method for producing the same, and a method for producing a coating liquid for a deodorizing layer. [Means for solving the problem]

[0010] The present invention employs the following configuration. [1] A support and a deodorizing agent layer fixed to the support, The deodorizing material is characterized in that the deodorizing agent layer contains activated carbon, a functional material consisting of at least one of silica gel and zeolite, acid hydrazide, aminotriazole, and a binder. [2] The deodorizing material according to [1], wherein the aminotriazole is one or both of 3-amino-1,2,4-triazole and 4-amino-1,2,4-triazole. [3] The deodorizing material according to [1] or [2], wherein the material that accounts for the largest mass proportion of the materials constituting the support is inorganic fiber. [4] A method for producing a coating liquid for a deodorant layer, comprising dispersing a functional material consisting of at least one of silica gel and zeolite, an acid hydrazide, and aminotriazole in water, adding activated carbon, and then mixing in a binder. [5] The method for producing a coating liquid for a deodorant layer according to [4], wherein a thickener is further added when the activated carbon is added. [6] A step of producing a coating liquid for a deodorant layer by the method for producing a coating liquid for a deodorant layer according to [4] or [5]; a step of applying and impregnating the obtained coating liquid for the deodorant layer onto a support; a drying step of drying the support coated and impregnated with the coating liquid for the deodorant layer; A method for producing a deodorizing material, comprising: [Effects of the Invention]

[0011] The deodorizing material of the present invention is effective in removing aldehydes, while using activated carbon which is effective against many odorous gas components but does not have the effect of removing aldehydes. Furthermore, according to the method for producing a coating liquid for a deodorizing layer of the present invention, it is possible to produce a coating liquid for obtaining a deodorizing layer that is also excellent in removing aldehydes, while using activated carbon that is effective against many odorous gas components but does not have the effect of removing aldehydes. Furthermore, according to the method for producing a deodorizing material of the present invention, it is possible to produce a deodorizing material that is excellent in removing aldehydes while using activated carbon that does not have the effect of removing many odorous gas components and aldehydes. [Brief explanation of the drawings]

[0012] [Figure 1] 1 is a schematic partial cross-sectional view of a deodorizing material according to one embodiment of the present invention. [Figure 2] 1 is a plan view showing one embodiment of a support constituting a deodorizing material of the present invention. [Figure 3] FIG. 10 is a plan view showing another embodiment of the support constituting the deodorizing material of the present invention. [Figure 4] FIG. 10 is a diagram showing the results of an initial performance test. [Figure 5] FIG. 10 shows the results of an attenuation test. DETAILED DESCRIPTION OF THE INVENTION

[0013] In this specification, a numerical range expressed using "to" means a range that includes the numerical values ​​before and after "to" as the lower and upper limits.

[0014] <Deodorizing material> 1 is a schematic partial cross-sectional view of a deodorizing material 1 according to one embodiment of the present invention. The deodorizing material 1 of this embodiment includes a support 10 and deodorizing agent layers 20 fixed to both sides of the support 10.

[0015] [Support] The material constituting the support 10 is not particularly limited as long as it can adhere the material constituting the deodorant layer 20 and maintain its shape, and can be made of inorganic materials, organic materials, or a combination of these.

[0016] Furthermore, the material constituting the support 10 is preferably fibrous, since it can be easily made into a nonwoven fabric or a woven fabric and can easily absorb and retain the chemical solution by capillary action. In particular, a nonwoven fabric can be easily formed by wet papermaking. Examples of inorganic fibers include glass fibers, ceramic fibers, and carbon fibers. Among these, glass fibers are preferred in terms of safety to the human body and cost. Examples of organic fibers include pulp and resin fibers.

[0017] The support 10 preferably contains 30% by mass or more of inorganic fibers, more preferably 40% by mass or more, and even more preferably 50% by mass or more. By containing inorganic fibers, the support 10 can be provided with high heat resistance, high thermal insulation, non-flammability, etc. Of the materials constituting the support 10, the material that accounts for the largest mass ratio is preferably inorganic fiber. It is also preferable to use a combination of inorganic fibers and organic fibers in the support 10. By including organic fibers in addition to inorganic fibers, moldability is improved.

[0018] The basis weight of the support 10 is not particularly limited, but in the case of a nonwoven fabric, it is 10 to 100 g / m 2 It is preferable to set the thickness to 15 to 60 g / m 2 If the basis weight is equal to or greater than the lower limit of the preferred range, the strength of the nonwoven fabric and the support 10 obtained from the nonwoven fabric and molded into a corrugated shape or the like can be sufficiently obtained. If the basis weight is equal to or less than the upper limit of the preferred range, the thickness can be suppressed, and pressure loss can also be suppressed.

[0019] There is no particular limitation on the shape of the support 10, and a nonwoven fabric or the like may be used in a sheet form as is. In the case of a sheet form, it can be used as an air filter, as well as a deodorizing sheet or wallpaper for use in a room or car. When the deodorizing material 1 is used as an air filter, it is preferable to give it a corrugated shape like the cross section of cardboard or a pleated shape folded in a zigzag pattern, as this makes it easier to increase the contact area with air and maintain a stable shape.

[0020] Among these, the corrugated shape is preferred because it not only produces an air filter with low pressure loss, but also makes it easy to apply and impregnate the slurry to form the deodorizing agent layer 20 and dry it, allowing the deodorizing material 1 to be obtained with high productivity. As for the corrugated shape, for example, a laminate of a liner member 15 and a corrugated member 16 can be used as the support, as shown in the first sheet 11 of FIG. 2 and the second sheet 12 of FIG.

[0021] When used as an air filter, the pitch of the corrugated member 16 is preferably 2 to 8 mm, more preferably 4 to 6 mm, and the height of the corrugated member 16 is preferably 1 to 5 mm, more preferably 2 to 4 mm. The pitch and height of the corrugated members 16 do not need to be uniform, and for example, corrugated members 16 of different heights and pitches may be used for each stage. Furthermore, when corrugated members 16 of the same height and pitch are used for each stage, the phases may be the same or different.

[0022] When used as an air filter, the support 10 of the deodorizing material 1 may be formed by alternately stacking two or more layers of, for example, the first sheet 11 shown in Fig. 2 and the second sheet 12 shown in Fig. 3. In this case, it is preferable to stack the liner members 15 of the first sheet 11 and the liner members 15 of the second sheet 12 in a direction that intersects with each other in terms of contact efficiency with odorous gases.

[0023] [Deodorizing layer] The deodorizing agent layer 20 is a layer containing activated carbon, a functional material, an acid hydrazide, aminotriazole, and a binder. The functional material is at least one of silica gel and zeolite. Silica gel and zeolite do not impair the function of the acid hydrazide even when they coexist with the acid hydrazide. In the deodorant layer 20, the acid hydrazide and aminotriazole are considered to be present mainly supported by the functional material.

[0024] (activated carbon) Activated carbon has a large surface area and pore volume, and therefore has the effect of removing odorous substances from general air due to its physical adsorption ability. The activated carbon used in this embodiment is preferably in powder form. Average particle size D of activated carbon measured by laser diffraction and scattering method 50 It is preferable that the particle size is 5 to 150 μm. However, since the above particle size range is an average particle size, activated carbon powders having particle sizes around this range are also included.

[0025] The specific surface area of ​​activated carbon powder (calculated by the BET method based on the amount of nitrogen adsorption) is 500 to 2000 m 2 / g is preferred. By making the specific surface area equal to or greater than the preferred lower limit, the contact area with air increases, and the amount of malodorous components adsorbed can be increased sufficiently.By making the specific surface area equal to or less than the preferred upper limit, a balance between cost and performance can be achieved.

[0026] Examples of raw materials for activated carbon include coconut shells, coal, wood, resins such as phenolic resin, old tires, etc. Pores in the activated carbon can be developed by heating and burning these raw materials, and then appropriately activating them with chemicals or gases, or appropriately washing them with acidic chemicals. After calcination and activation, the product is pulverized using a pulverizer such as a ball mill or a jet mill to obtain activated carbon powder.

[0027] The proportion of activated carbon in the deodorant layer is preferably 10 to 40% by mass, more preferably 15 to 35% by mass, and even more preferably 20 to 30% by mass, in terms of dry solid content. By making the proportion of activated carbon lower than the proportion of functional material, it is possible to suppress a decrease in the performance of the acid hydrazide. By making the proportion of activated carbon in the deodorant layer equal to or less than the preferred upper limit, it is possible to suppress a decrease in the performance of the acid hydrazide. By making the proportion of activated carbon in the deodorant layer equal to or more than the preferred lower limit, it is possible to achieve an excellent deodorizing effect on many odorous gas components other than aldehydes.

[0028] (functional materials) The functional material selected from at least one of silica gel and zeolite is a porous powder. Silica gel is an aggregate of primary particles whose main component is silicon dioxide, and can be obtained by various methods such as the gas phase method, the wet method (precipitation method), the sol-gel method, etc. Silica gel obtained by any method can be used as long as it has the desired properties. The silica gel serves as a carrier for the acid hydrazide and aminotriazole.

[0029] Examples of zeolite include zeolite Y, zeolite X, and zeolite ZSM-5. Among these, zeolite Y is preferred because it has a high deodorizing effect per unit weight of acid hydrazide and aminotriazole carried. Zeolite functions as a carrier for acid hydrazide and aminotriazole, and also as a deodorizer for acetic acid, methyl mercaptan, etc. The use of zeolite can supplement the function of activated carbon.

[0030] As the functional material, silica gel is preferred because it is inexpensive. It is also preferred to use silica gel in combination with zeolite, which functions as a carrier for the acid hydrazide and aminotriazole, as well as to supplement the function of activated carbon. Volume-based average particle diameter D of functional materials measured by laser diffraction and scattering method 50It is preferable that the particle size is 5 to 150 μm. However, since the above particle size range is an average particle size, functional materials with particle sizes around this range are also included.

[0031] The specific surface area of ​​functional materials (calculated by the BET method based on the amount of nitrogen adsorption) is 50 to 700 m 2 / g is preferred, and 200 to 600m 2 / g is more preferred. When the specific surface area is equal to or greater than the preferred lower limit, the contact area between the supported acid hydrazide and aminotriazole and air increases, and the amount of aldehyde gas adsorbed can be sufficiently increased.When the specific surface area is equal to or less than the preferred upper limit, the pore size does not become too small, and the acid hydrazide and aminotriazole are not prevented from entering the pores.

[0032] The proportion of the functional material in the deodorant layer is preferably 40 to 80% by mass, more preferably 45 to 70% by mass, and even more preferably 50 to 60% by mass, in terms of dry solids. When the proportion of the functional material in the deodorant layer is equal to or greater than the preferred lower limit, the functional material functions as a carrier for the acid hydrazide. When the proportion of the functional material in the deodorant layer is equal to or less than the preferred upper limit, the proportion of activated carbon increases, enhancing the deodorizing effect on many odorous gas components other than aldehydes.

[0033] (Acid hydrazide) Acid hydrazides are used to deodorize aldehydes, and exhibit excellent chemical adsorption properties for acetaldehyde and the like. Examples of acid hydrazides include lauric acid hydrazide, salicylic acid hydrazide, formhydrazide, acetohydrazide, propionic acid hydrazide, p-hydroxybenzoic acid hydrazide, naphthoic acid hydrazide, 3-hydroxy-2-naphthoic acid hydrazide, oxalic acid dihydrazide, malonic acid dihydrazide, succinic acid dihydrazide, adipic acid dihydrazide, azelaic acid dihydrazide, sebacic acid dihydrazide, dodecanedioic acid dihydrazide, maleic acid dihydrazide, fumaric acid dihydrazide, diglycolic acid dihydrazide, tartaric acid dihydrazide, malic acid dihydrazide, isophthalic acid dihydrazide, terephthalic acid dihydrazide, dimer acid dihydrazide, and 2,6-naphthoic acid dihydrazide. Of these, acid dihydrazides are preferred, succinic acid dihydrazide, adipic acid dihydrazide, and isophthalic acid dihydrazide are more preferred, and adipic acid dihydrazide is particularly preferred. The acid hydrazides may be used alone or in combination of two or more.

[0034] The proportion of acid hydrazide in the deodorant layer is preferably 1.5 to 10 mass %, more preferably 2 to 8 mass %, and even more preferably 3 to 5 mass %, in terms of dry solids. When the proportion of acid hydrazide in the deodorant layer is equal to or greater than the preferred lower limit, the adsorption performance of aldehydes is improved. When the proportion of acid hydrazide in the coating liquid for the deodorant layer is equal to or less than the preferred upper limit, the deodorizing effect of many odorous gas components other than aldehydes is enhanced.

[0035] The content of acid hydrazide (dry solid content) in the deodorant layer is preferably 1 to 20% by mass, more preferably 3 to 10% by mass, of the content of the functional material (dry solid content). When the ratio of acid hydrazide to the content of the functional material in the deodorant layer is equal to or greater than the preferred lower limit, the effect of being supported on the functional material (improved adsorption rate) is exerted. When the ratio of acid hydrazide to the content of the functional material in the deodorant layer is equal to or less than the preferred upper limit, the amount of acid hydrazide relative to the functional material is optimized, which is economical.

[0036] (aminotriazole) Examples of aminotriazoles include 3-amino-1,2,4-triazole, 4-amino-1,2,4-triazole, 3,5-diamino-1,2,4-triazole, 5-amino-3-mercapto-1,2,4-triazole, and 3-amino-5-phenyl-1,2,4-triazole. Among these, one or both of 3-amino-1,2,4-triazole and 4-amino-1,2,4-triazole are preferred. The aminotriazoles may be used alone or in combination of two or more.

[0037] The proportion of aminotriazole in the deodorant layer is preferably 1.5 to 10 mass %, more preferably 2 to 8 mass %, and even more preferably 3 to 5 mass %, in terms of dry solid content. When the proportion of aminotriazole in the deodorant layer is equal to or greater than the preferred lower limit, the adsorption performance of aldehydes is improved. When the proportion of aminotriazole in the coating liquid for the deodorant layer is equal to or less than the preferred upper limit, the deodorizing effect of many odorous gas components other than aldehydes is enhanced.

[0038] The content (dry solid content) of aminotriazole in the coating liquid for the deodorant layer is preferably 1 to 20 mass %, more preferably 3 to 10 mass %, relative to the content (dry solid content) of the functional material. When the ratio of aminotriazole to the content of the functional material in the coating liquid for a deodorant layer is equal to or greater than the preferred lower limit, the effect of being supported on the functional material (improved adsorption rate) is exerted.When the ratio of aminotriazole to the content of the functional material in the coating liquid for a deodorant layer is equal to or less than the preferred upper limit, the amount of aminotriazole relative to the functional material is optimized, which is economical.

[0039] The content of aminotriazole (dry solid content) in the coating liquid for the deodorant layer is preferably 85 to 115 mass %, more preferably 90 to 110 mass %, relative to the content of acid hydrazide (dry solid content). By setting the adsorption amount within the above range, it is easy to achieve both the adsorption speed and the adsorption amount of aldehydes.

[0040] (binder) As the binder, known inorganic binders and organic binders can be used. Examples of inorganic binders include colloidal silica, water glass, calcium silicate, alumina sol, alkoxysilane, etc. Examples of organic binders include emulsion-based organic binders, and in particular, acrylic emulsions such as acrylic resin, styrene-acrylic resin, acrylic-silicone resin, acrylic-urethane resin, vinyl acetate-acrylic resin, and polysiloxane-acrylic resin, and latex emulsions such as butadiene resin can be used. Among these, binders that have excellent adhesion properties to activated carbon and are unlikely to remain in the pores of activated carbon, such as water-based acrylic resins, are preferred.

[0041] The proportion of the binder in the deodorant layer varies depending on the type of binder, but is preferably 2 to 15 mass % and more preferably 3 to 10 mass % in terms of dry solids. When the proportion of the binder in the deodorant layer is equal to or greater than the preferred lower limit, powder falling off is suppressed. When the proportion of the binder in the coating liquid for the deodorant layer is equal to or less than the preferred upper limit, a decrease in the deodorizing effect of the activated carbon can be prevented.

[0042] (thickener) The deodorant layer 20 may contain a thickener as a component contained in the slurry for forming the deodorant layer 20 . Examples of thickeners include sodium polyacrylate, acrylic copolymers, polyacrylic acid, carboxylic acid copolymers (ammonium salts), carboxylic acid copolymers (e.g., carboxylic acid copolymer sodium salts such as sodium carboxymethyl cellulose), cross-linked sodium polyacrylate, cross-linked acrylic polymers, and cross-linked polyacrylic acid.

[0043] When a thickener is used, the proportion of the thickener in the coating liquid for the deodorant layer is preferably 0.1 to 3 mass% in terms of dry solids, depending on the type of thickener. When the proportion is equal to or greater than the preferred lower limit, the dispersibility of the activated carbon and functional material during production is improved. When the proportion is equal to or less than the preferred upper limit, deterioration of dispersibility due to excessive thickening during production can be prevented.

[0044] (Other ingredients) The deodorizing agent layer 20 may contain, as needed, flame retardants, colorants, wetting agents, paper strength improvers, water-resistant agents, pH adjusters, antifoaming agents, preservatives, anti-fungal agents, etc. Examples of pH adjusters include organic acids and inorganic acids. Among these, organic acids are preferred because they are effective in deodorizing ammonia, trimethylamine, etc. Examples of organic acids include tartaric acid, malic acid, citric acid, lactic acid, succinic acid, maleic acid, phthalic acid, and nicotinic acid.

[0045] [Other aspects of deodorizing materials] The deodorizing material 1 shown in Figure 1 is in an embodiment in which the deodorizing layer 20 is formed on both sides of the support 10, but the deodorizing layer 20 may be formed on only one side of the support 10. The deodorant layer 20 is preferably formed entirely on one or both surfaces, but may be formed partially. In addition to the deodorant layer 20, other deodorant layers may be provided. When used as an air filter, the air filter may be made up of only the deodorizing material 1, but the air filter may also be made up of a combination of the deodorizing material 1 and another deodorizing material.

[0046] <Coating liquid for deodorant layer> The coating liquid for the deodorizing layer is a coating liquid for forming the deodorizing layer 20, and contains activated carbon, a functional material consisting of at least one of silica gel and zeolite, acid hydrazide, aminotriazole, and a binder. As the medium, an aqueous solvent is preferred from the viewpoint of safety and workability, and water is usually used.

[0047] The coating liquid for the deodorant layer may contain a thickener. A thickener is particularly preferably used when it is difficult to constantly stir the coating liquid when applying or impregnating the coating liquid for the deodorant layer onto the support 10, or when the coating liquid separates into an emulsion containing water and binder components, and the activated carbon and functional material.

[0048] The solids concentration of the coating liquid for the deodorant layer can be adjusted appropriately depending on the coating / impregnation method, and is preferably adjusted to about 10 to 50% by mass. When the solids concentration of the coating liquid for the deodorant layer is equal to or higher than the preferred lower limit, the effect of removing aldehydes and odorous components other than aldehydes is enhanced. When the solids concentration of the coating liquid for the deodorant layer is equal to or lower than the preferred upper limit, the amount of chemicals blended is optimized, making it economical.

[0049] <Method of manufacturing coating liquid for deodorant layer> There are no particular limitations on the method for producing the coating liquid for the deodorant layer, but it is preferable to disperse a functional material consisting of at least one of silica gel and zeolite, acid hydrazide, and aminotriazole in water, add activated carbon, and then mix in a binder.

[0050] By preparing an aqueous dispersion containing a functional material, an acid hydrazide, and an aminotriazole, and then adding activated carbon to the resulting aqueous dispersion, the functions of the acid hydrazide and aminotriazole can be more easily exhibited. This is thought to be because the acid hydrazide and aminotriazole are supported on the functional material before the activated carbon is added, thereby reducing contact between the acid hydrazide and the activated carbon. Furthermore, by mixing the binder last, it is possible to prevent the binder from penetrating into the pores of the activated carbon or functional material.

[0051] <Deodorizing material manufacturing method> The deodorant material of this embodiment can be produced by the steps of producing a support, producing a coating liquid for a deodorant layer, and forming a deodorant layer from the obtained coating liquid for a deodorant layer. The process of forming the deodorant layer includes a step of applying and impregnating a support with a coating liquid for the deodorant layer, and a drying step of drying the support coated and impregnated with the coating liquid for the deodorant layer. The step of producing the coating liquid for the deodorant layer is preferably carried out by the above-mentioned method for producing the coating liquid for the deodorant layer. A specific description will be given below using the deodorizing material 1 shown in FIG. 1 as an example.

[0052] [Manufacture of support] There are no particular limitations on the method for manufacturing the substrate 10 of the deodorizing material 1. When the substrate 10 is constructed by wet-laid papermaking to obtain a nonwoven fabric containing inorganic fibers, the weighted average fiber diameter of the inorganic fibers used is preferably 3 to 10 μm, more preferably 4 to 7 μm. If the weighted average fiber diameter is equal to or greater than the preferred lower limit, the substrate is safe for the human body. If the weighted average fiber diameter is equal to or less than the preferred upper limit, the resulting substrate has excellent strength. The weighted average fiber diameter is calculated by measuring the fiber diameters of 100 fibers by microscopic observation.

[0053] The weighted average fiber length of the inorganic fibers used is preferably 1 to 15 mm, more preferably 1 to 10 mm. If the weighted average fiber length is equal to or greater than the preferred lower limit, the strength of the resulting support is excellent. If the weighted average fiber length is equal to or less than the preferred upper limit, the formation of the resulting support is excellent. The length-weighted average fiber length is calculated by measuring the fiber lengths of 100 fibers by microscopic observation.

[0054] When the support 10 is constructed by obtaining a nonwoven fabric containing inorganic fibers and organic fibers by wet papermaking, the weighted average fiber diameter of the organic fibers used together with the inorganic fibers (excluding organic fibers that are used as binder components and do not retain their fibrous shape due to heating during production, etc.; the same applies below) is not particularly limited, but is preferably no more than three times, and more preferably no more than two times, the weighted average fiber diameter of the inorganic fibers.

[0055] When the weighted average fiber diameter of the organic fibers is three times or less the weighted average fiber diameter of the inorganic fibers, the effect of the organic fibers in reducing the rigidity of the support and the effect of improving the folding endurance tend to be improved. There is no particular lower limit for the weighted average fiber diameter of the organic fibers, but it is preferably 1 μm or more, more preferably 3 μm or more. The weighted average fiber diameter is calculated by measuring the fiber diameters of 100 fibers by microscopic observation.

[0056] The aspect ratio (ratio of weighted average fiber length to weighted average fiber diameter) of the organic fibers used together with the inorganic fibers is preferably 300 to 5000, more preferably 400 to 3000. If the aspect ratio is equal to or greater than the preferred lower limit, the effect of reducing rigidity is obtained and the folding strength is also increased, which tends to make the corrugated crests less likely to tear and to reduce the generation of paper dust. If the aspect ratio is equal to or less than the preferred upper limit, the fibers tend to be less likely to be bound.

[0057] The raw material slurry for obtaining a nonwoven fabric by wet papermaking contains inorganic fibers (mainly glass fibers) and, if necessary, organic fibers, and may optionally contain organic or inorganic binder components, auxiliaries, additives, fillers, etc. Water is usually used as the medium.

[0058] The organic binder component is a component that bonds fibers together. Examples of the organic binder component include thermoplastic resins that melt at least in part when heated during the production of the nonwoven fabric. The form of the organic binder component is not limited, and may be any of fibrous, particulate, emulsion, liquid, etc. Thermosetting resins can also be used as the organic binder component.

[0059] The inorganic binder component is not particularly limited, but examples thereof include colloidal silica, water glass, calcium silicate, silica sol, alumina sol, sepiolite, and alkoxysilane.

[0060] Wet papermaking can be carried out by preparing a raw material slurry containing the above-mentioned components and water (medium), and then making paper from the raw material slurry using a known papermaking machine. Examples of papermaking machines include cylinder papermaking machines, tilted papermaking machines, Fourdrinier papermaking machines, and short wire papermaking machines. Among these papermaking machines, multi-layer papermaking can be carried out using a combination of the same or different types of papermaking machines. There are also no particular limitations on the methods of dewatering and drying after papermaking.

[0061] In addition to adding the binder component to the raw material slurry, a liquid containing the binder component may be applied (external application) to the nonwoven fabric after papermaking by methods such as spray coating, curtain coating, impregnation coating, bar coating, roll coating, blade coating, etc. The nonwoven fabric to be externally applied may be a dried nonwoven fabric after drying, or a wet web before drying.

[0062] When the support 10 is to have a corrugated shape like the first sheet 11 and the second sheet 12, the obtained nonwoven fabric is subjected to a corrugating process to give it a wave shape (unevenness), thereby obtaining a corrugated member 16. Next, the obtained corrugated member 16 and a liner member 15 (non-corrugated nonwoven fabric) are bonded to produce a single corrugated body. Then, a plurality of single corrugated bodies can be stacked or formed into a cylindrical shape to form a corrugated shape.

[0063] To obtain a sheet-like support having a planar shape like the first sheet 11 in Figure 2 or the second sheet 12 in Figure 3 and a thickness in the thickness direction of the paper, the liner member 15 and the corrugated member 16 are laminated together, and then cut to a predetermined thickness in a plane perpendicular to the lamination direction. As described above, the first sheet 11 in FIG. 2 and the second sheet 12 in FIG. 3 may be alternately stacked in two or more layers and bonded to each other.

[0064] Examples of adhesives used for bonding the liner member 15 and the corrugated member 16, the first sheet 11 and the second sheet 12, etc. include inorganic adhesives such as colloidal silica, water glass, sepiolite, and alumina sol, and one or more of these can be used. Furthermore, organic adhesives such as ethylene-vinyl alcohol may also be used in combination as the adhesive. The support 10 may be used as is or may be fired before use.

[0065] [Deodorant layer formation] In the method for producing a deodorizing material of this embodiment, the formation of the deodorizing layer includes a step of applying and impregnating a support with a coating liquid for the deodorizing layer, and a drying step of drying the support coated and impregnated with the coating liquid for the deodorizing layer.

[0066] As a method for applying and impregnating the support 10 with the coating liquid for the deodorant layer, known coating methods and impregnation methods can be used, and are not particularly limited, but may be appropriately selected, such as immersing the support in a reservoir of the coating liquid for the deodorant layer, or submerging the support in a curtain of the coating liquid for the deodorant layer, etc. The application and impregnation steps may be carried out multiple times.

[0067] The coating liquid for the deodorant layer is such that the amount of activated carbon (dry solid content) per unit area of ​​the support 10 is 20 to 150 g / m 2 It is preferable to apply or impregnate the material so that the amount is 50 to 130 g / m 2 It is more preferable to apply or impregnate the material so that the above condition is satisfied. The coating liquid for the deodorant layer has a total amount (dry solid content) of acid hydrazide and aminotriazole per unit area of ​​the support 10 of 10 to 200 g / m 2 It is preferable to apply the coating so that the coating amount is 40 to 160 g / m 2 It is more preferable to apply or impregnate the material so that the above condition is satisfied.

[0068] By ensuring that the amount of coating / impregnation for the deodorant layer coating liquid is equal to or greater than the preferred lower limit, it is possible to obtain a sufficient effect of removing malodorous components. By ensuring that the amount of coating / impregnation for the deodorant layer coating liquid is equal to or less than the preferred upper limit, it is possible to easily remove excess liquid and ensure a stable coating film.

[0069] After the step of applying and impregnating the coating liquid for the deodorant layer, a drying step is carried out. The temperature in the drying step is preferably 105 to 120°C. By keeping the temperature in the drying step at or above the preferred lower limit, the drying step time can be shortened. By keeping the temperature in the drying step at or below the preferred upper limit, the risk of activated carbon ignition can be reduced, allowing for safe production. In addition, the deterioration of the function of the acid hydrazide can be suppressed. The drying method in the drying step is not particularly limited, and any known method can be used.

[0070] [Action and effect] The deodorizer of this embodiment uses activated carbon and is also excellent in the effect of removing aldehydes. When acid hydrazide is used together with activated carbon, the function of the acid hydrazide is reduced, and the amount of aldehyde adsorbed decreases. However, according to the present embodiment, by using aminotriazole, which is less susceptible to the influence of activated carbon, in combination, the decrease in the amount of aldehyde adsorbed can be suppressed.

[0071] Furthermore, although aminotriazole is slower in aldehyde adsorption speed, it was found that even when aminotriazole is used in combination, the adsorption speed is almost the same as when acid hydrazide is used alone as an aldehyde removal agent. This is thought to be because even if the amount of functional groups (amine groups) on the acid hydrazide is reduced by the effect of activated carbon, the adsorption speed depends on the remaining functional groups on the acid hydrazide. [Example]

[0072] The present invention will be described in detail below with reference to examples, but the present invention is not limited to the following description.

[0073] <Raw materials> The coating liquid for the deodorant layer in each example was prepared using the following raw materials. Acid hydrazide: Adipic acid hydrazide (ADH) Triazole: 4-amino-1,2,4-triazole

[0074] Silica gel: Mizukasil (registered trademark) P-758C, manufactured by Mizusawa Industrial Chemicals, Ltd. Zeolite 1: Y-type zeolite Zeolite 2: ZSM-5 type zeolite

[0075] Activated carbon: Powdered activated carbon SA1000, manufactured by Futamura Chemical Co., Ltd., moisture content 50% by mass Thickener: Carboxymethylcellulose pH adjuster: organic acid Binder: styrene-acrylic resin

[0076] <Preparation of coating liquid for deodorant layer> The coating liquid for the deodorant layer in each example was prepared using raw materials having the composition shown in Table 1 (unit: parts by mass of solid content) according to the following procedure. First, the aldehyde adsorbent and functional material were dispersed in water to obtain a dispersion. To this dispersion, activated carbon and a thickener were added in this order and mixed. Next, an organic acid and a binder were added to obtain a coating liquid for a deodorant layer of each example.

[0077] [Table 1]

[0078] <Initial performance test> The adsorption speed of the filter (adsorbent) using the coating liquid for the deodorant layer of each example was evaluated by the following initial performance test.

[0079] The support for the filter (adsorbent) was Oji F-Tex Glass Paper PHN-50G (a glass nonwoven fabric made from glass fiber and pulp, with a basis weight of 50 g / m). 2 ) was used, which had a corrugated shape equivalent to that of the first sheet 11 in Figure 2 (100 mm long x 100 mm wide, 10 mm thick, approximately 70 cells per square inch. The pitch of the corrugated member 16 was 5.9 mm, and the height was 3.5 mm).

[0080] The support was impregnated with 24 g (including water) of the coating liquid for the deodorant layer of each example, and then heated and dried at 105° C. for 30 minutes to obtain the filter of each example. Test vessel (internal volume 1m 3 An acrylic wind tunnel (with a fan) was set in an acrylic chamber, and the obtained filter was placed in the wind tunnel.

[0081] Then, acetaldehyde was injected into the test vessel so that the initial concentration of acetaldehyde in the gas (test gas) in the test vessel was approximately 20 ppm, and then the fan was operated to ventilate the test gas through the filter at a wind speed of 1.6 m / s for approximately 30 minutes, and the change in acetaldehyde concentration during that time was determined.

[0082] The initial acetaldehyde concentration and the acetaldehyde concentration after ventilating for t minutes after injecting acetaldehyde are both values ​​obtained by subtracting the acetaldehyde concentration (background concentration) in the test vessel before injecting acetaldehyde. The results are shown in Figure 4. In Figure 4, natural attenuation is the change in acetaldehyde concentration when no filter was installed in the wind tunnel of the test vessel.

[0083] As shown in FIG. 4, Comparative Example 2, in which aminotriazole was used without acid hydrazide, was inferior in adsorption speed to Comparative Example 1, in which acid hydrazide was used, and it was found that aminotriazole alone cannot ensure a sufficient adsorption speed. In contrast, Example 1, in which acid hydrazide and aminotriazole were used in combination, showed an adsorption speed that was almost comparable to that of Comparative Example 1, even though the amount of acid hydrazide used was half that of Comparative Example 1.

[0084] <Attenuation test> The adsorption amount of the filter (adsorbent) using the coating liquid for the deodorant layer of each example was evaluated by the following decay test.

[0085] The support for the filter (adsorbent) was Oji F-Tex Glass Paper PHN-50G (a glass nonwoven fabric made from glass fiber and pulp, with a basis weight of 50 g / m). 2 ) was used, which had a corrugated shape equivalent to that of the first sheet 11 in Figure 2 (50 mm long x 50 mm wide, 5 mm thick, approximately 70 cells per square inch. The pitch of the corrugated member 16 was 5.9 mm, and the height was 3.5 mm).

[0086] The support was impregnated with 4 g of the coating liquid for the deodorant layer (including water) of each example, and then heated and dried at 105° C. for 30 minutes to obtain the filter of each example. An acrylic wind tunnel (with a fan) was set in a test container (a flask with an internal volume of 5 L), and the obtained filter was placed in the wind tunnel.

[0087] Then, acetaldehyde was injected into the test vessel so that the initial concentration of acetaldehyde in the gas (test gas) in the test vessel was 500 to 1000 ppm, and then the fan was operated to blow the test gas through the filter at a wind speed of 1.0 m / s for 15 minutes. This test was repeated 4 to 7 times.

[0088] The amount of aldehyde adsorption for each ventilation was calculated from the difference in acetaldehyde concentration before and after ventilation. Figure 5 shows the relationship between the acetaldehyde concentration after each ventilation (final concentration) and the cumulative adsorption amount. In Figure 5, the portion where the rate of increase in the cumulative adsorption amount relative to the final concentration decreases indicates that the cumulative adsorption amount has approached the equilibrium adsorption amount of the filter.

[0089] As shown in FIG. 5, Comparative Example 1, in which acid hydrazide was used without aminotriazole, had a lower adsorption amount than Comparative Example 2, in which aminotriazole was used. This indicates that acid hydrazide alone cannot ensure a sufficient adsorption amount in the presence of activated carbon. In contrast to this, Example 1, which used acid hydrazide and aminotriazole in combination, showed an increased adsorption amount compared to Comparative Example 1, and it was found that a certain amount of adsorption could be ensured even in the presence of activated carbon. [Explanation of symbols]

[0090] 1. Deodorizing material 10 Support 11 Sheet 1 12 Second Sheet 15 Liner material 16 Corrugated material 20 Deodorizing layer

Claims

1. A support and a deodorant layer fixed to the support, The deodorizing material is characterized in that the deodorizing agent layer contains activated carbon, a functional material consisting of at least one of silica gel and zeolite, acid hydrazide and aminotriazole supported on the functional material, and a binder.

2. 2. The deodorizing material according to claim 1, wherein the aminotriazole is one or both of 3-amino-1,2,4-triazole and 4-amino-1,2,4-triazole.

3. 3. The deodorizing material according to claim 1, wherein the material that accounts for the largest mass proportion of the materials constituting the support is inorganic fiber.

4. A method for producing a coating liquid for a deodorant layer, comprising dispersing a functional material consisting of at least one of silica gel and zeolite, an acid hydrazide, and an aminotriazole in water, causing the acid hydrazide and aminotriazole to be supported on the functional material, adding activated carbon, and further mixing in a binder.

5. The method for producing a coating liquid for a deodorant layer according to claim 4, wherein a thickener is further added when the activated carbon is added.

6. a step of producing a coating liquid for a deodorant layer by the method for producing a coating liquid for a deodorant layer according to claim 4 or 5; a step of applying and impregnating the obtained coating liquid for the deodorant layer onto a support; a drying step of drying the support coated and impregnated with the coating liquid for the deodorant layer; A method for producing a deodorizing material, comprising:

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