WO2023182153A1

WO2023182153A1 - Deodorizing material, production method therefor, and production method for deodorizing agent layer coating liquid

Info

Publication number: WO2023182153A1
Application number: PCT/JP2023/010355
Authority: WO
Inventors: 良司高濱
Original assignee: 王子ホールディングス株式会社
Priority date: 2022-03-25
Filing date: 2023-03-16
Publication date: 2023-09-28
Also published as: JP2023142757A

Abstract

Provided is a deodorizing material 1 characterized by comprising a support 10 and a deodorizing agent layer 20 that is fixed to the support 10, wherein the deodorizing agent layer 20 contains activated carbon, a functional material that comprises silica gel and/or zeolite, acid hydrazide, aminotriazole, and a binder. The deodorizing agent 1 has an excellent effect of removing aldehyde, while using activated carbon, which is effective against many odorous gas components but does not provide an aldehyde removal effect.

Description

Deodorizing material and its manufacturing method, and manufacturing method of coating liquid for deodorizing layer

The present invention relates to a deodorizing material, a method for producing the same, and a method for producing a coating liquid for a deodorant layer.
This application claims priority based on Japanese Patent Application No. 2022-049817 filed in Japan on March 25, 2022, the contents of which are incorporated herein.

In recent years, due to changes in the living environment and increased health consciousness, air conditioning equipment such as air conditioners, air purifiers, humidifiers, and dehumidifiers have become widely used in various living spaces such as residences, offices, factories, and automobiles. These air conditioners use various air filters to obtain purified air.

Air filters are required to have the ability to remove foul-smelling gases that exist in living spaces such as residences, offices, factories, and automobiles. Components of malodorous gas include lower 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, These include SO ₂ , NO ₂ , and aromatic hydrocarbons such as toluene and xylene.
Among them, acetaldehyde falls under both the 22 types of specific malodorous substances specified by the Offensive Odor Prevention Law and the 13 types of volatile organic compounds (VOC) whose concentration guideline values are determined by the Ministry of Health, Labor and Welfare.

Activated carbon, which is generally used as a deodorizing agent, is effective against many odor gas components, but it is difficult to adsorb aldehydes (Patent Document 1).
It is known that acid hydrazide is effective for removing aldehydes (Patent Document 2). However, acid hydrazide has little effect on odor gases other than aldehydes.

Therefore, it is possible to use activated carbon and acid hydrazide together, but if they are used together, activated carbon acts as a catalyst and the functional group (amine group) of acid hydrazide is oxidized, resulting in a decrease in performance against aldehydes. is known (Non-patent Document 1).
The deodorizing material can be obtained by applying a slurry containing a deodorizing agent to a support and drying the slurry. Activated carbon, which is used as a deodorizing agent, needs to be dried to remove enough internal water. However, if it is dried at high temperatures in consideration of production efficiency, the deterioration in performance due to the coexisting acid hydrazide becomes more pronounced. .

Aminotriazole is also known to be effective in removing acetaldehyde (Patent Document 3).
Therefore, it is possible to use activated carbon and aminotriazole in combination, but aminotriazole has a lower adsorption speed than acid hydrazide.

Japanese Patent Application Publication No. 2010-58075 International Publication No. 2009/122975 Japanese Patent Application Publication No. 2004-2523

The present invention has been made in view of the above circumstances, and uses activated carbon, which is effective against many odor gas components but does not have an effect on removing aldehydes, and a deodorizing material that also has an excellent effect on removing aldehydes. An object of the present invention is to provide a method for producing the same and a method for producing a coating liquid for a deodorant layer.

The present invention employs the following configuration.
[1] Comprising a support and a deodorizing layer fixed to the support,
A deodorizing material, wherein the deodorizing layer contains activated carbon, a functional material made of at least one of silica gel and zeolite, an acid hydrazide, an 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 occupies the largest mass proportion of the materials constituting the support is inorganic fiber.
[4] A coating liquid for a deodorizing layer, in which a functional material consisting of at least one of silica gel and zeolite, an acid hydrazide, and an aminotriazole are dispersed in water, and then activated carbon is added and a binder is further mixed. Production method.
[5] The method for producing a coating liquid for a deodorizing layer according to [4], wherein a thickener is further added when adding the activated carbon.
[6] A step of producing a deodorant layer coating liquid by the method for producing a deodorant layer coating liquid according to [4] or [5],
a step of coating and impregnating the support with the obtained deodorizer layer coating liquid;
a drying step of drying the support coated and impregnated with the deodorizing agent layer coating liquid;
A method for producing a deodorizing material, comprising:

The deodorizing material of the present invention uses activated carbon, which is effective against many odor gas components but does not have an effect on removing aldehydes, and is also excellent in removing aldehydes.
In addition, according to the method for producing a coating liquid for a deodorizing layer of the present invention, activated carbon, which is effective against many odorous gas components but does not have an effect on removing aldehydes, is used, while a deodorizer that is also effective in removing aldehydes can be used. A coating liquid for obtaining a coating layer can be produced.
Further, according to the method for producing a deodorizing material of the present invention, it is possible to produce a deodorizing material that is also excellent in removing aldehydes while using activated carbon that does not have the effect of removing many odor gas components and aldehydes.

FIG. 1 is a schematic partial cross-sectional view of a deodorizing material according to an embodiment of the present invention. FIG. 2 is a plan view showing one embodiment of a support that constitutes the deodorizing material of the present invention. It is a top view which shows the other aspect of the support body which comprises the deodorizing material of this invention. FIG. 3 is a diagram showing the results of an initial performance test. It is a figure which shows the result of an attenuation test.

In this specification, a numerical range expressed using "-" means a range that includes the numerical values written before and after "-" as lower and upper limits.

<Deodorizing material>
FIG. 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 surfaces of the support 10, respectively.

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

Further, the material constituting the support body 10 is preferably fibrous because it can be easily made into a nonwoven fabric or a woven fabric, and it can easily absorb liquid by capillary phenomenon and retain the chemical liquid. In particular, nonwoven fabrics can be easily formed by wet papermaking.
Examples of inorganic fibers include glass fibers, ceramic fibers, carbon fibers, and the like. Among them, glass fiber is preferable from the viewpoint of safety for the human body and cost. Examples of organic fibers include pulp and resin fibers.

The support 10 preferably contains inorganic fibers in an amount of 30% by mass or more, more preferably 40% by mass or more, and still more preferably 50% by mass or more. By containing inorganic fibers, high heat resistance, high heat insulation properties, nonflammability, etc. can be provided.
Among the materials constituting the support body 10, it is preferable that the material occupying the largest mass proportion is inorganic fiber.
Moreover, it is also preferable that the support body 10 is constructed using a combination of inorganic fibers and organic fibers. By including organic fibers in addition to inorganic fibers, moldability is improved.

The basis weight of the support 10 is not particularly limited, but in the case of a nonwoven fabric, it is preferably 10 to 100 g/m ² , more preferably 15 to 60 g/m ² . If the basis weight is at least the lower limit of the preferred range, sufficient strength can be obtained for the nonwoven fabric and the support 10 formed from the nonwoven fabric into a corrugated shape or the like. If the basis weight is below the upper limit of the preferable range, the thickness can be suppressed and pressure loss can also be suppressed.

There is no particular limitation on the shape of the support 10, and nonwoven fabric or the like may be used as it is in the form of a sheet. In sheet form, in addition to being used as air filters, it can also be used as deodorizing sheets and wallpaper inside rooms and cars.
When using the deodorizing material 1 as an air filter, it is recommended to use a corrugated shape like a cross section of cardboard or a pleated shape folded in a zigzag shape because it is easy to increase the contact area with air, maintain a stable shape, and is cheap. It is preferable to do so.

Among them, the corrugated shape not only makes it possible to create an air filter with low pressure loss, but also makes it easy to apply and impregnate slurry to form the deodorizing agent layer 20 and dry it, making it possible to obtain the deodorizing material 1 with high productivity. This is preferable because it allows
As for the corrugated shape, for example, as shown in the first sheet 11 in FIG. 2 and the second sheet 12 in FIG. 3, a layered structure of a liner member 15 and a corrugated member 16 can be used as the support.

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. Further, 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; for example, corrugated members 16 having different heights and pitches may be used in each stage. Further, when corrugated members 16 having the same height and pitch are used in each stage, the phases may be the same or different.

When used as an air filter, the support 10 of the deodorizing material 1 may be, for example, two or more layers of the first sheet 11 in FIG. 2 and the second sheet 12 in FIG. 3 stacked alternately. In that case, it is preferable to overlap the liner member 15 of the first sheet 11 and the liner member 15 of the second sheet 12 in a direction that intersects with each other in terms of contact efficiency with odor gas.

[Deodorant layer]
The deodorizer layer 20 is a layer containing activated carbon, a functional material, an acid hydrazide, an aminotriazole, and a binder.
The functional material is at least one of silica gel and zeolite. Even when silica gel and zeolite coexist with acid hydrazide, they do not reduce the functionality of acid hydrazide. In the deodorant layer 20, the acid hydrazide and aminotriazole are considered to exist mainly in a state supported by the functional material.

(activated carbon)
Since activated carbon has a large surface area and pore volume, its physical adsorption ability is effective in removing common airborne odorous substances. The activated carbon used in this embodiment is preferably in powder form.
The volume-based average particle diameter D ₅₀ of activated carbon as determined by laser diffraction/scattering method is preferably 5 to 150 μm. However, since the above particle size range is the average particle size, it also includes activated carbon powder having particle sizes around that range.

The specific surface area of the activated carbon powder (calculated by the BET method based on the nitrogen adsorption amount) is preferably 500 to 2000 m ² /g.
When the specific surface area is at least the preferable lower limit, the contact area with air increases, and the amount of malodorous components adsorbed can be sufficiently increased. By setting the specific surface area to a preferable upper limit or less, cost and performance can be balanced.

Raw materials for activated carbon include coconut shells, coal, wood, resins such as phenolic resins, old tires, and the like. The pores of the activated carbon can be developed by heating and firing these raw materials and subjecting them to activation treatment with a chemical or gas, or washing treatment with an acidic chemical.
After firing and activation, activated carbon powder can be obtained by pulverizing using a pulverizer such as a ball mill or a jet mill.

The proportion of activated carbon in the deodorizer 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 ratio of activated carbon smaller than the ratio of functional material, it is possible to suppress the performance deterioration of acid hydrazide. When the ratio of activated carbon in the deodorizing agent layer is below the preferable upper limit, deterioration in the performance of acid hydrazide can be suppressed. When the proportion of activated carbon in the deodorizing agent layer is at least the preferable lower limit, the deodorizing effect of many odor gas components other than aldehydes is excellent.

(functional material)
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 mainly composed of silicon dioxide, and can be obtained by various methods such as a gas phase method, a wet method (sedimentation method), and a sol-gel method. Any silica gel obtained by any method can be used as long as the desired characteristics can be obtained.
Silica gel functions as a carrier for acid hydrazides and aminotriazoles.

Examples of the zeolite include zeolite Y type, zeolite X type, and zeolite ZSM-5 type. Among them, type Y is preferable because it has a high deodorizing effect per unit weight of acid hydrazide and aminotriazole supported.
Zeolite functions as a carrier for acid hydrazide and aminotriazole, and also as a deodorizing agent for acetic acid, methyl mercaptan, and the like. By using zeolite, it is possible to supplement the function of activated carbon.

As the functional material, silica gel is preferred because it is inexpensive. It is also preferable to use silica gel and zeolite in combination to function as a carrier for acid hydrazide and aminotriazole, as well as to supplement the function of activated carbon.
The volume-based average particle diameter D ₅₀ of the functional material determined by laser diffraction/scattering method is preferably 5 to 150 μm. However, since the above particle size range is the average particle size, it also includes functional materials having particle sizes before and after this range.

The specific surface area of the functional material (calculated by the BET method based on the nitrogen adsorption amount) is preferably 50 to 700 m ² /g, more preferably 200 to 600 m ² /g.
When the specific surface area is at least the preferable 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 below the preferable upper limit, the pore diameter does not become too small and entry of acid hydrazide and aminotriazole into the pores is not prevented.

The proportion of the functional material in the deodorizer 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 solid content. . When the proportion of the functional material in the deodorizing layer is at least the preferable lower limit, it functions as a carrier for acid hydrazide. When the proportion of the functional material in the deodorizing agent layer is below the preferable upper limit, the proportion of activated carbon increases and the deodorizing effect on many odor gas components other than aldehydes is enhanced.

(acid hydrazide)
Acid hydrazides are used to deodorize aldehydes. Acid hydrazide exhibits good chemical adsorption performance for acetaldehyde and the like.
Examples of acid hydrazides include lauric acid hydrazide, salicylic acid hydrazide, form hydrazide, acetohydrazide, propionic acid hydrazide, p-hydroxybenzoic acid hydrazide, naphthoic acid hydrazide, 3-hydroxy-2-naphthoic acid hydrazide, oxalic acid dihydrazide, and malonic acid hydrazide. , succinic acid dihydrazide, adipic acid dihydrazide, azelaic acid dihydrazide, sebacic acid dihydrazide, dodecanoic acid dihydrazide, maleic acid dihydrazide, fumaric acid dihydrazide, diglycolic acid dihydrazide, tartaric acid dihydrazide, malic acid dihydrazide, isophthalic acid dihydrazide, terephthalic acid dihydrazide, dimer Examples include acid dihydrazide and 2,6-naphthoic acid dihydrazide. Among these, acid dihydrazide is preferred, succinic acid dihydrazide, adipic acid dihydrazide, and isophthalic acid dihydrazide are more preferred, and adipic acid dihydrazide is particularly preferred.
The acid hydrazide may be used alone or in combination of two or more.

The proportion of acid hydrazide in the deodorizing agent layer is preferably 1.5 to 10% by mass, more preferably 2 to 8% by mass, and even more preferably 3 to 5% by mass, as a dry solid content. When the proportion of acid hydrazide in the deodorizing agent layer is at least the preferable lower limit, the adsorption performance of aldehydes is improved. When the proportion of the acid hydrazide in the coating liquid for the deodorant layer is below the preferable upper limit, the deodorizing effect of many odor gas components other than aldehydes is enhanced.

The content of acid hydrazide (dry solid content) in the deodorant layer is preferably 1 to 20% by mass, and preferably 3 to 10% by mass, based on the content of the functional material (dry solid content). More preferred. When the ratio of acid hydrazide to the content of the functional material in the deodorizing agent layer is at least the preferable lower limit, the effect of supporting the functional material (improvement of adsorption rate) is exhibited. By setting the ratio of acid hydrazide to the content of the functional material in the deodorant layer to be less than or equal to the preferable upper limit, the amount of acid hydrazide relative to the functional material is optimized and economical.

(Aminotriazole)
Examples of aminotriazole include 3-amino-1,2,4-triazole, 4-amino-1,2,4-triazole, 3,5-diamino-1,2,4-triazole, 5-amino-3 Examples include -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.
Aminotriazole may be used alone or in combination of two or more.

The proportion of aminotriazole in the deodorizing agent layer is preferably 1.5 to 10% by weight, more preferably 2 to 8% by weight, and even more preferably 3 to 5% by weight, as a dry solid content.
When the proportion of aminotriazole in the deodorizing agent layer is at least the preferable lower limit, the adsorption performance of aldehydes is improved. When the proportion of aminotriazole in the deodorizing agent layer coating liquid is below the preferable upper limit, the deodorizing effect of many odor gas components other than aldehydes is enhanced.

The content of aminotriazole (dry solid content) in the coating liquid for the deodorant layer is preferably 1 to 20% by mass, and preferably 3 to 10% by mass, based on the content of the functional material (dry solid content). It is more preferable that there be.
When the ratio of aminotriazole to the content of the functional material in the coating liquid for the deodorizing layer is at least the preferable lower limit, the effect of supporting the functional material (improvement of adsorption rate) is exhibited. By setting the ratio of aminotriazole to the content of the functional material in the deodorant layer coating liquid to be less than or equal to the preferable upper limit, the amount of aminotriazole relative to the functional material is optimized and economical.

The content of aminotriazole (dry solid content) in the coating liquid for the deodorant layer is preferably 85 to 115% by mass, and preferably 90 to 110% by mass, based on the content of acid hydrazide (dry solid content). It is more preferable that there be.
By setting it within the above range, it is easy to achieve both adsorption speed and adsorption amount of aldehydes.

(binder)
As the binder, known inorganic binders and organic binders can be used.
Examples of the inorganic binder include colloidal silica, water glass, calcium silicate, alumina sol, and alkoxylan. Examples of the organic binder include emulsion-based organic binders, particularly acrylic resins such as acrylic resin, styrene-acrylic resin, acrylic-silicon resin, acrylic-urethane resin, vinyl acetate-acrylic resin, and polysiloxane-acrylic resin. Emulsions, latex emulsions such as butadiene resins, etc. 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.

Although the proportion of the binder in the deodorizing agent layer depends on the type of binder, it is preferably 2 to 15% by mass, more preferably 3 to 10% by mass, in terms of dry solid content. When the proportion of the binder in the deodorizing agent layer is at least the preferable lower limit, powder falling is suppressed. When the proportion of the binder in the deodorizing agent layer coating liquid is at most the preferable upper limit, it is possible to prevent the deodorizing effect of activated carbon from decreasing.

(Thickener)
The deodorizer layer 20 may contain a thickener as a component contained in the slurry to form the deodorizer layer 20.
Examples of thickeners include sodium polyacrylate, acrylic copolymers, polyacrylic acid, carboxylic acid copolymers (ammonium salts), carboxylic acid copolymers (e.g. carboxylic acid copolymers such as sodium carboxymethyl cellulose) Examples include sodium copolymer salt), crosslinked sodium polyacrylate, crosslinked acrylic polymer, and crosslinked polyacrylic acid.

When using a thickener, the proportion of the thickener in the coating liquid for the deodorizing layer depends on the type of thickener, but is preferably 0.1 to 3% by mass as dry solid content. When the above ratio is at least the preferable lower limit, the dispersibility of activated carbon and functional material during production is improved. When the above-mentioned ratio is below the preferable upper limit, it is possible to prevent deterioration of dispersibility due to excessive thickening during production.

(Other ingredients)
The deodorizing agent layer 20 may contain a flame retardant, a coloring agent, a wetting agent, a paper strength improver, a waterproofing agent, a pH adjuster, an antifoaming agent, a preservative, an anti-mold agent, etc., as necessary. . Examples of the pH adjuster include organic acids and inorganic acids. Among them, organic acids are preferred because they are effective in deodorizing ammonia, trimethylamine, and the like. Examples of organic acids include tartaric acid, malic acid, citric acid, lactic acid, succinic acid, maleic acid, phthalic acid, and nicotinic acid.

[Other aspects of deodorizing material]
Although the deodorizing material 1 shown in FIG. 1 has a deodorizing agent layer 20 formed on both sides of the support 10, the deodorizing agent layer 20 may be formed only on one side of the support 10.
Moreover, although it is preferable that the deodorizing agent layer 20 is formed on the entire surface of one surface or both surfaces, it may be formed partially.
Further, in addition to the deodorant layer 20, another deodorant layer may be included.
Further, when used as an air filter, the air filter may be configured with only the deodorizing material 1, but the air filter may be configured with a combination of the deodorizing material 1 and other deodorizing materials.

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

The coating liquid for the deodorant layer may contain a thickener. Thickeners are used when it is difficult to constantly stir the coating liquid when coating and impregnating the support 10 with the coating liquid for the deodorizing layer, or when the coating liquid is an emulsion containing water or a binder component and activated carbon. It is particularly suitable for use in cases where the material is separated into functional materials.

The solid content concentration of the coating liquid for the deodorant layer can be adjusted as appropriate depending on the method of coating and impregnation, and is preferably adjusted to about 10 to 50% by mass. When the solid content concentration of the coating liquid for the deodorizing agent layer is at least the preferable lower limit, the effect of removing aldehydes and odor components other than aldehydes is enhanced. When the solid content concentration of the coating liquid for the deodorizing layer is below the preferable upper limit, the amount of chemicals to be blended is optimized and economical.

<Method for manufacturing coating liquid for deodorant layer>
There are no particular limitations on the method for producing the coating liquid for the deodorant layer, but after dispersing a functional material consisting of at least one of silica gel and zeolite, acid hydrazide, and aminotriazole in water, activated carbon is added, and then activated carbon is added. , a binder is preferably mixed.

By preparing an aqueous dispersion containing a functional material, an acid hydrazide, and an aminotriazole, and adding activated carbon later to the obtained aqueous dispersion, the functions of the acid hydrazide and the aminotriazole can be easily exhibited. This seems to be because the acid hydrazide and aminotriazole are supported on the functional material before the activated carbon is added, which reduces contact between the acid hydrazide and the activated carbon.
Furthermore, by mixing the binder last, it is possible to suppress the binder from penetrating into the pores of the activated carbon and the functional material.

<Method for manufacturing deodorizing material>
The deodorizing material of this embodiment can be manufactured by a step of manufacturing a support, a step of manufacturing a coating liquid for a deodorizing layer, and a step of forming a deodorizing agent layer using the obtained coating liquid for a deodorizing layer.
The step of forming the deodorizer layer includes a step of applying and impregnating the support with the deodorizer layer coating liquid, and a drying step of drying the support coated and impregnated with the deodorant layer coating liquid.
The step of producing a coating liquid for a deodorant layer is preferably performed by the method for producing a coating liquid for a deodorant layer described above.
The deodorizing material 1 shown in FIG. 1 will be specifically explained below by taking the example of the deodorizing material 1 shown in FIG.

[Manufacture of support]
There is no particular limitation on the manufacturing method of the support 10 of the deodorizing material 1, but when the support 10 is constructed by obtaining a nonwoven fabric containing inorganic fibers by wet papermaking, the weighted average fiber diameter of the inorganic fibers used is 3 to 3. The thickness is preferably 10 μm, more preferably 4 to 7 μm. If the weighted average fiber diameter is at least the preferable lower limit, it is safe for the human body. If the weighted average fiber diameter is less than or equal to the preferable upper limit, the resulting support will have excellent strength. Note that the weighted average fiber diameter is calculated by measuring the fiber diameters of 100 fibers by microscopic observation.

Furthermore, 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 at least the preferable lower limit, the resulting support will have excellent strength. When the weighted average fiber length is less than or equal to the preferable upper limit, the resulting support will have excellent texture. Note that the length-weighted average fiber length is calculated by measuring the fiber length of 100 fibers by microscopic observation.

When constructing the support 10 by obtaining a nonwoven fabric containing inorganic fibers and organic fibers by wet papermaking, the organic fibers used together with the inorganic fibers (however, the organic fibers used together with the inorganic fibers (however, they are used as a binder component and do not retain their fiber shape due to heating etc. during production) The weighted average fiber diameter of the fibers (excluding organic fibers (hereinafter the same)) is not particularly limited, but is preferably 3 times or less, more preferably 2 times or less, than the weighted average fiber diameter of the inorganic fibers. preferable.

When the weighted average fiber diameter of the organic fibers is three times or less than the weighted average fiber diameter of the inorganic fibers, the effect of reducing the rigidity of the support and improving the folding strength of the organic fibers tends to be improved. The lower limit of the weighted average fiber diameter of the organic fibers is not particularly limited, but is preferably 1 μm or more, more preferably 3 μm or more. Note that the weighted average fiber diameter of the fiber diameters is calculated by measuring the fiber diameters of 100 fibers by microscopic observation.

Further, the aspect ratio (ratio of weighted average fiber length to weighted average fiber diameter) of the organic fiber used together with the inorganic fiber is preferably 300 to 5000, more preferably 400 to 3000. When the aspect ratio is at least the preferable lower limit, the effect of reducing rigidity is obtained and the folding strength is also increased, so that the corrugated peaks are less likely to tear and paper dust is less likely to be generated. If the aspect ratio is below the preferable upper limit, the fibers tend to be difficult to bundle.

The raw material slurry for obtaining a nonwoven fabric by wet papermaking contains inorganic fibers (mainly glass fibers) and organic fibers as necessary, and optionally organic or inorganic binder components, auxiliaries, additives, fillers, etc. May include. Moreover, water is usually used as a medium.

The organic binder component is a component that bonds fibers together. Examples of the organic binder component include thermoplastic resins that are at least partially melted by heating during production of the nonwoven fabric. There is no restriction on the form of the organic binder component, and it may be in any form such as fibrous, particulate, emulsion, or liquid form. A thermosetting resin can also be used as the organic binder component.

The inorganic binder component is not particularly limited, and examples thereof include colloidal silica, water glass, calcium silicate, silica sol, alumina sol, sepiolite, alkoxylan, and the like.

Wet paper making can be carried out by preparing a raw material slurry containing each of the above-mentioned components and water (medium), and then making paper from the raw material slurry using a known paper machine. Examples of paper machines include cylinder paper machines, inclined paper machines, fourdrinier paper machines, and short wire paper machines. Among these paper machines, paper machines of the same type or different types may be combined to perform multilayer paper making. There are no particular restrictions on the dehydration and drying methods after papermaking.

In addition to adding the binder component to the raw material slurry, a liquid containing the binder component can be applied to the nonwoven fabric after papermaking by methods such as spray coating, curtain coating, impregnation coating, bar coating, roll coating, and blade coating. (External additive application) may also be used. The nonwoven fabric to which the external additive is applied may be a dry nonwoven fabric after drying, or a wet web before drying.

When the support body 10 has a corrugated shape like the first sheet 11 and the second sheet 12, the corrugated member 16 is formed by corrugating the obtained nonwoven fabric to give it a corrugated shape (irregularities). is obtained.
Next, the obtained corrugated member 16 and liner member 15 (non-woven fabric not subjected to corrugated processing) are bonded together to produce a single-wave molded body. A corrugated shape can be obtained by stacking a plurality of single-wave molded bodies or forming a cylindrical shape.

In order to obtain a sheet-like support having a shape like the first sheet 11 in FIG. 2 and the second sheet 12 in FIG. 16 and then cut to a predetermined thickness on a plane perpendicular to the lamination direction.
As described above, two or more layers of the first sheet 11 in FIG. 2 and the second sheet 12 in FIG. 3 may be alternately stacked and bonded to each other.

Examples of adhesives used for adhering the liner member 15 and the corrugated member 16, and for adhering the first sheet 11 and the second sheet 12 include inorganic glues such as colloidal silica, water glass, sepiolite, and alumina sol. One or more of these can be used. Further, as the adhesive, an organic glue such as ethylene-vinyl alcohol may be used in combination.
The support 10 may be used as is or after being fired.

[Formation of deodorizer layer]
In the method for producing a deodorizing material of the present embodiment, the formation of the deodorizing agent layer includes a step of applying and impregnating a support with a deodorizing agent layer coating liquid, and a step of applying and impregnating a support with the deodorizing agent layer coating liquid. A drying step is provided.

As a method for applying and impregnating the support 10 with the deodorant layer coating liquid, known coating methods and impregnation methods can be used, and there are no particular limitations. The method may be selected as appropriate, such as by immersing the support in a coating solution for the deodorizing agent layer, or by submerging the support in a curtain containing a coating liquid for the deodorizing layer. The coating/impregnating process may be performed multiple times.

The coating liquid for the deodorizing layer is preferably applied and impregnated so that the amount of activated carbon (dry solid content) per unit area of the support 10 is 20 to 150 g/ ^m2 , and is 50 to 130 g/ ^m2 . It is more preferable to apply and impregnate.
Further, the coating liquid for the deodorant layer is preferably applied so that the total amount of acid hydrazide and aminotriazole (dry solid content) per unit area of the support 10 is 10 to 200 g/m ² , and 40 g/m 2 . It is more preferable to apply and impregnate the coating so that the amount is 160 g/m ² .

By setting the coating/impregnating amount of the deodorizing agent layer coating liquid to a preferable lower limit or more, a sufficient effect of removing malodorous components can be obtained. By setting the coating/impregnating amount of the deodorizing agent layer coating liquid to a preferable upper limit or less, it is possible to easily remove excess liquid and to ensure a stable coating film.

After the process of applying and impregnating the deodorizer layer coating liquid, a drying process is performed.
The temperature in the drying step is preferably 105 to 120°C. By setting the temperature of the drying process to a preferable lower limit or higher, the time of the drying process can be shortened. By setting the temperature in the drying step to a preferable upper limit or lower, the risk of ignition of activated carbon can be reduced and production can be carried out safely. Further, it is possible to suppress the functional decline of acid hydrazide.
Note that the drying method in the drying step is not particularly limited, and any known method can be used.

[Effect]
According to the deodorizing agent of the present embodiment, activated carbon is used and the deodorizing agent is also excellent in the effect of removing aldehydes.
When acid hydrazide is used together with activated carbon, the function of acid hydrazide decreases and the amount of aldehyde adsorbed decreases, but according to this embodiment, by using aminotriazole, which is less affected by activated carbon, in combination, the amount of aldehyde adsorbed decreases. can be suppressed.

Furthermore, although aminotriazole is inferior in the adsorption speed of aldehydes, it was found that even when aminotriazole is used in combination, almost the same adsorption speed can be obtained compared to when using only acid hydrazide as an aldehyde removal agent. Ta. This is considered to be because even if the amount of functional groups (amine groups) in acid hydrazide is reduced due to the effect of activated carbon, the adsorption speed depends on the remaining functional groups in acid hydrazide.

Hereinafter, the present invention will be described in detail with reference to Examples, but the present invention is not limited to the following description.

<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

Silica gel: Mizukashiru (registered trademark) P-758C, manufactured by Mizusawa Chemical Industries Zeolite 1: Y type zeolite Zeolite 2: ZSM-5 type zeolite

Activated carbon: Powdered activated carbon SA1000, manufactured by Futamura Chemical Co., Ltd., water content 50% by mass
Thickener: Carboxymethyl cellulose pH adjuster: Organic acid Binder: Styrene-acrylic resin

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

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

As the support for the filter (adsorbent), glass paper PHN-50G manufactured by Oji F-Tex (glass nonwoven fabric using glass fiber and pulp, basis weight 50 g/m ² ) was used, equivalent to the first sheet 11 in FIG. (100 mm long x 100 mm wide, 10 mm thick, about 70 cells per square inch. The pitch of the corrugated members 16 was 5.9 mm, and the height was 3.5 mm.).

The above support was impregnated with 24 g (containing water) of the deodorant layer coating solution of each example. After impregnating, it was dried by heating at 105° C. for 30 minutes to obtain filters of each example.
An acrylic wind tunnel (with a fan) was set in a test container (an acrylic chamber with an internal volume of 1 m ³ ), and the obtained filter was placed in the wind tunnel.

After that, acetaldehyde was injected into the test container so that the initial concentration of acetaldehyde in the gas (test gas) in the test container was about 20 ppm, and then the fan was operated to blow the filter at a wind speed of 1.6 m/s. The test gas was passed through the chamber for about 30 minutes, and the change in acetaldehyde concentration during that period was determined.

Note that the initial acetaldehyde concentration and the acetaldehyde concentration after injecting acetaldehyde and allowing ventilation for t minutes are both values obtained by subtracting the acetaldehyde concentration (background concentration) in the test container before injecting acetaldehyde.
The results are shown in Figure 4. Note that in FIG. 4, natural attenuation is the change in acetaldehyde concentration when no filter was installed in the wind tunnel of the test container.

As shown in Figure 4, Comparative Example 2, which used aminotriazole without acid hydrazide, was inferior in adsorption speed to Comparative Example 1, which used acid hydrazide, and aminotriazole alone did not show sufficient adsorption speed. It turned out that it was not possible to secure it.
On the other hand, in Example 1, in which acid hydrazide and aminotriazole were used together, although the amount of acid hydrazide used was half that of Comparative Example 1, the adsorption speed was almost comparable to Comparative Example 1. Indicated.

<Attenuation test>
The adsorption amount of the filter (adsorbent) using the deodorizer layer coating liquid of each example was evaluated by the following attenuation test.

As the support for the filter (adsorbent), glass paper PHN-50G manufactured by Oji F-Tex (glass nonwoven fabric using glass fiber and pulp, basis weight 50 g/m ² ) was used, equivalent to the first sheet 11 in FIG. (50 mm long x 50 mm wide, 5 mm thick, about 70 cells per square inch. The pitch of the corrugated members 16 was 5.9 mm, and the height was 3.5 mm.) was used.

The above support was impregnated with 4 g (containing water) of the deodorant layer coating solution of each example. After impregnating, it was dried by heating at 105° C. for 30 minutes to obtain filters 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.

After that, acetaldehyde is injected into the test container so that the initial concentration of acetaldehyde in the gas (test gas) in the test container is 500 to 1000 ppm, and then the fan is operated to blow the air into the filter at a speed of 1.0 m/s. The test in which the test gas was passed through the tube for 15 minutes was repeated 4 to 7 times.

Based on the difference in the acetaldehyde concentration before and after each ventilation, the amount of aldehyde adsorbed at that time was determined. FIG. 5 shows the relationship between the acetaldehyde concentration (end concentration) after each round of ventilation and the cumulative adsorption amount. In FIG. 5, a portion where the rate of increase in the cumulative adsorption amount with respect to the final concentration decreased indicates that the cumulative adsorption amount approached the equilibrium adsorption amount of the filter.

As shown in Figure 5, Comparative Example 1 using acid hydrazide without using aminotriazole had a lower adsorption amount than Comparative Example 2 using aminotriazole, and acid hydrazide alone was insufficient in the presence of activated carbon. It was found that it was not possible to secure a sufficient amount of adsorption.
On the other hand, in Example 1, in which acid hydrazide and aminotriazole were used in combination, the amount of adsorption increased compared to Comparative Example 1, and it was found that a constant amount of adsorption could be ensured even in the presence of activated carbon. .

1 Deodorizing material 10 Support body 11 First sheet 12 Second sheet 15 Liner member 16 Corrugate member 20 Deodorizing agent layer

Claims

comprising a support and a deodorizer layer fixed to the support,
A deodorizing material, wherein the deodorizing layer contains activated carbon, a functional material made of at least one of silica gel and zeolite, an acid hydrazide, an aminotriazole, and a binder.
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.
The deodorizing material according to claim 1 or 2, wherein among the materials constituting the support, the material that occupies the largest mass proportion is inorganic fiber.
A method for producing a coating liquid for a deodorizing layer, which comprises dispersing a functional material consisting of at least one of silica gel and zeolite, acid hydrazide, and aminotriazole in water, then adding activated carbon, and further mixing a binder.
The method for producing a coating liquid for a deodorizing layer according to claim 4, wherein a thickener is further added when adding the activated carbon.
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 coating and impregnating the support with the obtained deodorizer layer coating liquid;
a drying step of drying the support coated and impregnated with the deodorizing agent layer coating liquid;
A method for producing a deodorizing material, comprising: