JP2015077536A - Adsorption sheet and method for producing the same, and air cleaner using the adsorption sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a new adsorption sheet that has excellent adsorption properties and can be particularly properly used when used as a filter of an air cleaner or the like.SOLUTION: An adsorption sheet (1) of the present invention includes a sheet-like air-permeable substrate (2), a porous adsorbent, and a binder that binds the air-permeable substrate (2) and the porous adsorbent. The sheet-like air-permeable substrate (2) has a plurality of openings (3) from one main surface to the other main surface.

Description

  The present invention relates to an adsorption sheet, a method for producing the same, and an air cleaner using the same.

  In the air, there are many chemical substances that can irritate various mucous membranes such as nasal mucosa, ocular mucosa, pharyngeal mucosa, and skin. Among them, volatile organic compounds (VOC) such as toluene, xylene, ethylbenzene, and styrene emanating from building materials, furniture, and daily necessities (Volatile Organic Compounds (VOC)), and highly volatile organic compounds such as formaldehyde and acetaldehyde (VVOOC) )) Is considered a cause of chemical sensitivity and sick house syndrome, and is therefore subject to emission regulations. VOC emissions have been declining year by year due to regulations, but health damage due to VOCs still exists, and regulations on VOC emissions have been further tightened around the world.

  According to the revised Building Standards Law enacted in July 2003, the amount of formaldehyde used in building materials was also restricted. However, the amount of acetaldehyde used as an alternative substance has been increasing rapidly in recent years. In April 2003, the Ministry of Health, Labor and Welfare issued VOC guidelines for 13 substances. Among 13 substances, the ratio of acetaldehyde exceeding the guideline value (0.03ppm) (about 40% over) (reference: 20% over toluene, over 11% over 11 other substances) is overwhelmingly large. It is a difficult substance to reduce.

  One of the means for removing these chemical substances is adsorption by a porous material such as activated carbon. For example, Patent Document 1 discloses a honeycomb-shaped activated carbon molded body obtained by combining activated carbon with a binder. Patent Document 2 discloses a filter using activated carbon fibers. However, these have a problem of high cost.

  Therefore, a sheet coated with activated carbon as an adsorbent is used to remove volatile organic compounds discharged from newly built houses, new appliances, and the like. However, when such an adsorbing sheet is used as a filter for an air purifier or the like, the pressure loss with respect to ventilation is high, so that when a sufficient amount of gas to be treated is to be ventilated, the power consumption of the fan increases. There is a problem. Such a problem is particularly remarkable when the basis weight of the base material of the sheet is large and when the amount of activated carbon to be coated is large.

  In this regard, for example, Patent Document 3 discloses a deodorizing filter using a net-like base material. Here, in order to reduce the pressure loss while increasing the amount of adsorbent retained, the filter is formed into a pleated shape. ing. Further, Patent Document 4 discloses a deodorizing filter using polyfoamed polyurethane as a base material. Here, in order to reduce the pressure loss while increasing the amount of adsorbent retained, the surface has a concavo-convex structure.

  In Patent Document 5, adsorbent particles and a thermoplastic resin are mixed and heated at a temperature equal to or higher than the melting point of the thermoplastic resin so that the thermoplastic resin particles are dissolved and adsorbent particles are bonded to each other. A method of manufacturing an adsorption filter having a vent by piercing a needle heated above the melting point of a thermoplastic resin is disclosed.

JP 2001-240405 A Japanese Patent Laid-Open No. 9-267015 JP 2003-1028 A JP-A-9-57050 JP 2010-46598 A

  Conventional adsorbing sheets are still insufficient in that the pressure loss is reduced while increasing the amount of adsorbent retained, and the adsorbing performance for the adsorbed components is not high.

  Therefore, an object of the present invention is to provide a novel adsorption sheet that has excellent adsorption characteristics and can be particularly preferably used when used as a filter for an air cleaner or the like.

The present inventors have found that the above problems can be solved by the following means.
[1]
An adsorbent sheet having a sheet-like breathable substrate, a porous adsorbent, and a binder that binds the porous adsorbent to the sheet-like breathable substrate,
The sheet-like breathable base material has a plurality of openings from one main surface to the other main surface.
Adsorption sheet.
[2]
The porous adsorbent is the adsorbent sheet according to [1], wherein the porous carrier carries a chemical adsorbent.
[3]
The adsorption sheet according to [2], wherein the porous carrier is selected from the group consisting of activated carbon, sepiolite, palygorskite, zeolite, activated carbon fiber, activated alumina, sepiolite mixed paper, silica gel, activated clay, permiculite, and diatomaceous earth. .
[4]
The adsorption sheet according to [2] or [3], wherein the chemical adsorbent is selected from the group if it is an azole compound, a hydrazide compound, and a combination thereof.
[5]
Area of one per the two openings 1 on the surface of the sheet-like breathable substrate ^is a 1 mm 2 to 20 mm ^2, the adsorption sheet according to any one of [1] to [4].
[6]
The suction sheet according to any one of [1] to [5], wherein a surface area ratio by the plurality of openings is in a range of 1.0 to 50%.
[7]
The adsorbent sheet according to any one of [1] to [6], wherein a holding amount of the porous adsorbent is 0.03 g / cm ³ or more per 1 cm ³ of the sheet-like breathable substrate.
[8]
[1] to [7] The difference between the pressure loss without the opening and the pressure loss with the plurality of openings is 0.20 mmAq or more with respect to the wind speed of 0.42 m / s. Adsorption sheet as described in any one of these.
[9]
The suction sheet according to any one of [1] to [8], wherein the plurality of openings are provided by mechanical means.
[10]
Any of [1] to [9], wherein the sheet-like breathable substrate is selected from the group consisting of a foamed resin, a net-like resin, a porous resin film, a knitted fabric, a woven fabric, a nonwoven fabric, paper, and inorganic fibers. The adsorption sheet according to one item.
[11]
[1] to [10], wherein the binder is selected from the group consisting of acrylic resin, acrylic-styrene resin, acrylic-silicon resin, acrylic-urethane resin, vinyl acetate-acrylic resin, polysiloxane-acrylic resin, and butadiene resin. ] The adsorption sheet as described in any one of.
[12]
The air cleaner which uses the adsorption sheet as described in any one of [1]-[11] as a filter.
[13]
Providing a porous adsorbent,
Providing a sheet-like breathable substrate having a plurality of openings from one main surface toward the other main surface; and binding the porous adsorbent to the sheet-like breathable substrate with a binder; The manufacturing method of the adsorption sheet containing this.
[14]
Providing a porous adsorbent,
Providing a sheet-like breathable substrate;
The porous adsorbent is bonded to the sheet-like breathable substrate by a binder, and the sheet-shaped breathable substrate to which the porous adsorbent is bonded is changed from one main surface to the other main surface. The manufacturing method of an adsorption sheet including forming the some opening part which goes to.

  The adsorption sheet of the present invention has excellent adsorption characteristics and can be particularly preferably used when used as a filter for an air cleaner or the like.

It is the schematic of the adsorption sheet of this invention. It is the schematic of the apparatus for evaluating an aldehyde adsorption | suction performance. It is the schematic of the manufacturing process of the adsorption sheet of Examples 1-4. It is a figure which shows how the relationship between activated carbon holding amount and a pressure loss changes with the case where there exists an opening part in an adsorption sheet, and a case where it does not exist. It is a figure which shows how the relationship between activated carbon holding amount and adsorption | suction performance changes with the case where an adsorption sheet has an opening part, and the case where there is no opening part.

<Adsorption sheet>
The adsorbent sheet of the present invention has a sheet-like breathable substrate, a porous adsorbent, and a binder that binds the porous adsorbent to the sheet-like breathable substrate. Here, in this adsorbing sheet, the plurality of openings from one main surface to the other main surface of the breathable base material are provided, so that the breathable base material has no openings. In comparison, the pressure loss with respect to the gas to be processed flowing through the adsorption sheet is low. Specifically, as shown schematically in FIG. 1, in the suction sheet 1 of the present invention, a plurality of openings 3 are provided in the sheet-like breathable base material 2. In addition, such an adsorption sheet of this invention can be manufactured by the method of this invention which manufactures an adsorption sheet, for example.

  In general, when an opening is provided in the breathable substrate of the adsorption sheet, the gas to be treated flows through the opening, and the adsorbed components in the gas to be treated and the adsorption held by the breathable substrate. It is considered that the chance of contact with the material is reduced, thereby reducing the adsorption performance for the adsorbed component. In contrast, the present inventors have found that an unexpectedly high adsorption performance can be obtained by providing a plurality of openings in the adsorption sheet holding the porous adsorbent. That is, the adsorption sheet of the present invention can provide unexpectedly high adsorption performance for an adsorbed component such as an aldehyde, although a plurality of openings are provided.

With respect to the present invention, for example, the adsorption performance for an adsorbed component such as an aldehyde is evaluated by the apparatus shown in FIG. 2 according to JEM1467 (Electrical Association of Japan: JEMA), Annex 1 deodorization performance test. be able to. Specifically, a gas to be treated containing an adsorbed component is caused to flow from a conduit 6 into a 1 m ³ space where an air purifier 4 and an agitation fan 5 using an adsorbing sheet as a filter are arranged. The adsorbed component concentration in the space before the operation of the cleaner 4 is measured by gas chromatography, and then the adsorbed component concentration in the space 30 minutes after the air cleaner 4 is operated, and the following formula is used: The adsorption performance for adsorbed components can be calculated:
Adsorption performance for adsorbed components [%]
= {1- (Adsorbed component concentration after 30 minutes) ÷ (Initial adsorbed component concentration)} × 100

(Porous adsorbent)
The porous adsorbent used in the adsorbing sheet of the present invention is not particularly limited as long as it can adsorb aldehydes. The porous adsorbent may be composed of the following porous materials, but preferably the porous adsorbent is a chemical adsorbent, that is, a chemical adsorbent, that is, a chemical adsorbent, between the porous adsorbent and the adsorbed component. An adsorbent that adsorbs a component to be adsorbed by generating a bond is supported. A physical adsorbent such as a porous carrier has a high adsorption rate, but has a property of easily desorbing an adsorption target, and a chemical adsorbent is difficult to desorb an adsorption target once adsorbed. On the other hand, the adsorption rate is low. In the adsorption sheet of the present invention, preferably, such a specific porous adsorbent is used in combination with a breathable base material having an opening to provide high adsorption performance.

  Although not limited to theory, the high adsorptive performance by the adsorbing sheet of the embodiment using the porous adsorbent carrying the chemical adsorbent is that the physical adsorbent of the porous adsorbent is a breathable substrate. The adsorbed components are rapidly adsorbed and removed not only from the gas to be treated flowing through the main body of the gas but also from the gas to be treated that passes through the opening of the breathable substrate, and the chemical adsorption of the porous adsorbent is performed. It is considered that the agent strongly adsorbs the adsorbed component that may be desorbed from the physical adsorbent.

(Porous adsorbent-porous carrier)
Any porous carrier having a large number of pores can be used as the porous carrier. For example, as the porous carrier, any one of an inorganic porous carrier and an organic porous carrier can be used.

  Specific examples of the inorganic porous carrier include activated carbon, sepiolite, palygorskite, zeolite, activated carbon fiber, activated alumina, sepiolite mixed paper, silica gel, activated clay, permiculite, and diatomaceous earth. Examples of the organic porous carrier include pulp, fiber, and polymer porous carrier. Among these porous carriers, activated carbon is preferable because it has excellent adsorption characteristics for various adsorbed components, particularly aldehydes. Here, as used herein, “adsorption property” means a property of adsorbing more components to be adsorbed and making it difficult to desorb the components to be adsorbed once adsorbed.

  The shape of the porous carrier is not particularly limited as long as the gas to be treated can be contacted. For example, a granular, powdery, or fibrous porous carrier can be used. When coating a porous carrier on a sheet-like breathable substrate, the porous carrier is preferably used in the form of a slurry. Therefore, in this case, a crushed and / or pulverized porous carrier may be selected. . Moreover, the kind and shape of the porous carrier used in the present invention can be selected according to the kind of the adsorbed component to be removed or the place where the adsorbing sheet is installed.

For example, the particle size (median diameter: D ₅₀ ) of the porous carrier is preferably small for slurry formation, and may be, for example, 150 μm or less, 50 μm or less, or 25 μm or less. In general, the BET specific surface area of the porous carrier is preferably as large as possible, and may be, for example, 400 m ² / g or more, 500 m ² / g or more, or 1000 m ² / g or more.

(Porous adsorbent-chemical adsorbent)
As the chemical adsorbent, any adsorbent capable of adsorbing the adsorbed component by forming a chemical bond with the intended adsorbed component can be used. As the chemical adsorbent, one kind or plural kinds of chemical adsorbents can be used.

  For example, when the intended adsorbed component is an aldehyde, one or a plurality of azole compounds and / or hydrazide compounds can be used as the chemical adsorbent. As used herein, an “azole compound” is a five-membered aromatic compound containing at least one heteroatom, wherein at least one of the heteroatoms is a nitrogen atom, particularly aldehydes. Meaning such compounds having the desired adsorption properties. Also, as used herein, “hydrazide compound” means a compound having one or more hydrazide groups, in particular such a compound having desired adsorption properties for aldehydes.

  The azole compound includes diazole, triazole, tetraazole and the like, specifically, 3-methyl-5-pyrazolone, 1,3-dimethyl-5-pyrazolone, 3-methyl-1-phenyl-5-razolone. Pyrazolone compounds such as 3-phenyl-6-pyrazolone and 3-methyl-1- (3-sulfophenyl) -5-pyrazolone; pyrazole, 3-methylpyrazole, 1,4-dimethylpyrazole, 3,5-dimethylzole 3,5-dimethyl-1-phenylpyrazole, 3-aminopyrazole, 5-amino-3-methylpyrazole, 3-methylpyrazole-5-carboxylic acid, 3-methylpyrazole-5-methyl carboxylate, 3-methyl Pyrazoles such as pyrazole-5-carboxylic acid ethyl ester and 3,5-methylpyrazole dicarboxylic acid Compound: 1,2,3-triazole, 1,2,4-triazole, 3-n-butyl-1,2,4-triazole, 3,5-dimethyl-1,2,4-triazole, 3,5 -Di-n-butyl-1,2,4-triazole, 3-mercapto-1,2,4-triazole, 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, 3-amino-5-phenyl-1,2,4-triazole, 3,5 -Diphenyl-1,2,4-triazole, 1,2,4-triazol-3-one, urazole (3,5-dioxy-1,2,4-triazole), 1,2,4-triazole-3- Carboxylic acid, 1-hydroxybenzo Triazole compounds such as riazole, 5-hydroxy-7-methyl-1,3,8-triazaindolizine, 1H-benzotriazole, 4-methyl-1H-benzotriazole, 5-methyl-1H-benzotriazole, 2- Amino-5-ethyl-1,3,4-thiadiazole, 5-amino-2-mercapto-1,3,4-thiadiazole, 2,5-dimercapto-1,3,4-thiadiazole, 5-t-butyl- Examples include thiadiazole compounds such as 2-methylamino-1,3,4-thiadiazole, 2-amino-5-methyl-1,3,4-thiadiazole, and 2-amino-1,3,4-thiadiazole.

  As the azole compound, in particular, 3-aminopyrazole, 5-amino-3-methylpyrazole, 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, 3-amino-5-phenyl-1,2,4-triazole 2-amino-5-ethyl-1,3 , 4-thiadiazole, 5-amino-2-mercapto-1,3,4-thiadiazole, 5-t-butyl-2-methylamino-1,3,4-thiadiazole, 2-amino-5-methyl-1, 3,4-thiadiazole and 2-amino-1,3,4-thiadiazole are preferred, and 4-amino-1,2,4-triazole is preferred.

  As the hydrazide compound, a monohydrazide compound, a dihydrazide compound, a trihydrazide compound, preferably a dibasic acid dihydrazide is preferable, and more preferably, adipic acid dihydrazide, sebacic acid dihydrazide, or the like can be used.

  The method for supporting the chemical adsorbent on the porous carrier is not particularly limited. For example, after the chemical adsorbent is dissolved in water or other solvent, the porous carrier is immersed in the obtained chemical solution. You may do it.

The loading amount of the chemical adsorbent can be appropriately determined according to the intended type and concentration of the adsorbed component. For example, the loading amount of the chemical adsorbent can be 0.04 μmol to 1 μmol or 0.06 μmol to 0.8 μmol per 1 m ² of the BET specific surface area of the porous carrier. That is, for example, 4 to 100 μmol or 6 to 80 μmol of a chemical adsorbent can be used for 100 g of a porous carrier having a BET specific surface area of 1000 m ² / g.

(Porous adsorbent-retained amount)
The adsorbing sheet of the present invention may hold a porous adsorbent in an arbitrary amount, and particularly may hold a relatively large amount of the porous adsorbent. If the air permeable substrate is not provided with openings, clogging of the air permeable substrate due to a large amount of porous adsorbent and an increase in pressure loss due to this will occur. It could not be retained. However, in the adsorption sheet of the present invention, even if an increase in the pressure loss of the main body (portion other than the opening) of the breathable substrate occurs due to the provision of a plurality of openings in the breathable substrate, Since the pressure loss at the opening of the breathable substrate is low, the increase in the pressure loss can be compensated. Thereby, the adsorption sheet of this invention can adsorb | suck a lot of to-be-adsorbed components over a long period of time.

Adsorption sheet of the present invention are, for example, 0.01 g / cm ³ or more, 0.02 g / cm ³ or more, 0.03 g / cm ³ or more, 0.04 g / cm ³ or more, 0.05 g / cm ³ or more, 0. 06g / cm ³ or more, or it may not hold the porous adsorbent with 0.07 g / cm ³ greater. The upper limit of the holding amount of the porous adsorbent is not particularly limited as long as the pressure loss of the adsorbing sheet does not become too high and can be manufactured. For example, the upper limit of the holding amount of the porous adsorbent may be 0.20 g / cm ³ or less, 0.15 g / cm ³ or less, or 0.10 g / cm ³ or less.

As used herein, “the amount of porous adsorbent retained” means the weight (g) of the porous adsorbent supported per 1 cm ³ of the sheet-like breathable base material. The weight of the material means the total weight of the porous carrier and the chemical adsorbent when the porous adsorbent includes a chemical adsorbent. When the porous adsorbent is coated on the air-permeable base material, the retained amount can be set to a desired value by adjusting the amount of use, concentration, etc. of the slurry containing the porous adsorbent.

(Sheet breathable substrate)
The sheet-like breathable substrate for the adsorbing sheet of the present invention is not particularly limited as long as it has breathability with respect to the gas to be treated. As the sheet-like air-permeable base material, those in which the slurry containing the porous adsorbent can penetrate into the base material in the production process are preferable. In addition, the breathable substrate is relatively rough, so that when the adsorption sheet of the present invention is used, the gas to be treated containing the adsorbed component reaches the inside of the sheet-like breathable substrate, It is preferable to promote contact between the adsorbed component and the porous adsorbent on the surface or inside of the substrate.

  Specific examples of the sheet-like breathable substrate include foamed resin, reticulated resin, porous resin film, knitted fabric, woven fabric, non-woven fabric, paper, and inorganic fiber. As the material, synthetic fibers such as polyethylene, polypropylene, polyurethane, nylon, polyester, polyvinyl chloride, polyvinylidene chloride, fluororesin, vinylon, polyacrylic polymer, cellulose acetate, and promix; semi-synthetic fibers; rayon, etc. Regenerated fibers; natural fibers such as cotton, hemp, silk, or inorganic fibers can be used. Further, the sheet-like breathable substrate may be a woven fabric woven with thin metal wires.

The basis weight of the sheet-like breathable substrate can be, for example, 50 to 500 g / m ² , 100 to 400 g / m ² , or 150 to 300 g / m ² . As used herein, “base weight of the substrate” means the weight of the sheet-like breathable substrate per 1 m ² .

  The thickness of the sheet-like breathable substrate, that is, the thickness of the adsorption sheet may be 0.5 mm or more, 1.0 mm or more, 3.0 mm or more, 5.0 mm or more, or 10 mm or more in consideration of the adsorption performance. . When the thickness is thick, the length of the opening is increased, and the adsorption target object is more likely to come into contact with the adsorbent. Moreover, this thickness may be 200 mm or less, 150 mm or less, 100 mm or less, 50 mm or less, or 30 mm or less, for example.

(Sheet breathable substrate-opening)
The opening provided in the sheet-like breathable substrate is an opening from one main surface to the other main surface, and passes through the sheet-like breathable substrate from one main surface to the other main surface. It may be an arbitrary opening that reduces the ventilation resistance to the gas to be processed. This opening may or may not penetrate from one main surface to the other main surface. In addition, with respect to the sheet-like breathable substrate, the “main surface” means two large surfaces facing each other.

  The shape of the opening is not particularly limited, but may have a cross-sectional shape such as a substantially circular shape, a circular shape, a substantially square shape, a square shape, a substantially rectangular shape, or a rectangular shape. The plurality of openings may be provided in a predetermined arrangement, for example, a 60 ° zigzag type, a square zigzag type, or a series type arrangement. The plurality of openings may be provided in an arrangement that forms a certain pattern, for example, a heart-shaped pattern. Moreover, the direction of the hole of the opening may be perpendicular to the main surface of the sheet-like breathable substrate or may be an oblique direction.

  The means for forming the opening in the sheet-like breathable substrate is not particularly limited, and for example, mechanical means, thermal means, and chemical means can be used. Preferably, the opening can be provided by mechanical means in which the opening does not deteriorate thermally or chemically, such as punching or drilling. Here, the term “mechanical” means that the substrate is opened by the shearing force of the tool without substantially melting the substrate. Further, the opening is formed simultaneously with the formation of the sheet-like breathable substrate, that is, for example, the formwork when forming the sheet-like breathable substrate has a shape corresponding to the opening. It may be.

The area per opening on one surface of the sheet-like breathable substrate is 0.5 mm ² or more, 1.0 mm ² or more, 3.0 mm ² or more, 7.0 mm ² or more, 12 mm ² or more, or 18 mm. It may be ² or more. The area per opening may be 300 mm ² or less, 100 mm ² or less, 50 mm ² or less, 30 mm ² or less, 20 mm ² or less, or 10 mm ² or less. Furthermore, the ratio of the opening area per unit area on one surface of the sheet-like breathable base material (surface open area ratio) may be 1% or more, 3% or more, and 5% or more. Further, the surface area ratio may be 50% or less, 40% or less, 30% or less, 20% or less, or 15% or less.

In the sheet-like breathable base material used in the adsorbing sheet of the present invention, the pressure loss is reduced due to the presence of the opening compared to the case where there is no opening. Specifically, for example, in a sheet-like breathable substrate containing a porous adsorbent at 0.07 g / cm ³ , the pressure loss when there is no opening and the pressure loss when there are a plurality of openings The difference may be 0.20 mmAq or more, 0.3 mmAq or more, 0.5 mmAq or more, 1.0 mmAq or more, or 2.0 mmAq or more with respect to a wind speed of 0.42 m / s. Further, this difference is 2.5 mmAq or less, 1.5 mmAq or less, 1.2 mmAq or less, 1.0 mmAq or less, 0.8 mmAq or less, or 0.5 mmAq or less with respect to a wind speed of 0.42 m / s. Good. In addition, the sheet-like breathable base material having no aperture is preferably 1.00 mmAq or less, 0.40 mAq or less with respect to a wind speed of 0.42 m / s in a state where the porous adsorbent is not bonded. It has a pressure loss of 50 mmAq or less, or 0.3 mmAq or less.

  Here, the pressure loss is as follows: an adsorption sheet cut to 50 mmφ is packed in a 50 mmφ column, a differential pressure gauge is set above and below the sheet in the column (inlet and outlet), and the flow rate is 50 L / min (wind velocity conversion 0.424 m / s) Is obtained by measuring the differential pressure between the inlet and the outlet caused by flowing air.

(binder)
As the binder, any binder that can bind the porous adsorbent and the sheet-like breathable substrate, for example, an inorganic binder such as colloidal silica, or an organic binder such as a polymer material can be used.

  In order to bond the porous adsorbent to the sheet-like breathable substrate using the binder, for example, the binder is added to the slurry containing the porous adsorbent, and the mixture is stirred for a predetermined time to be porous adsorbed. A slurry containing the material and binder can be obtained, and the substrate can be coated with such a slurry and dried. The coating can be performed, for example, by applying a slurry to the substrate.

  In the case where the porous adsorbent contains a chemical adsorbent, it is preferable to previously carry the chemical adsorbent on the porous carrier. In this case, even if the surface of the porous carrier is covered with the binder, the pores are mainly occupied by the chemical adsorbent, and thus the binder may theoretically block many of the pores. In addition, no binder is interposed between the carrier and the chemical adsorbent.

  Examples of organic binders include acrylic emulsions such as acrylic resins, acrylic-styrene resins, acrylic-silicon resins, acrylic-urethane resins, vinyl acetate-acrylic resins, polysiloxane-acrylic resins, and latex emulsions such as butadiene resins. Can be used. As the binder, a binder that hardly remains in the pores of the porous adsorbent, for example, an aqueous acrylic resin is preferable. The amount of the binder added can be, for example, 10 to 80% by weight with respect to the porous adsorbent, but is not limited to this range.

<Method for manufacturing adsorption sheet>
The method of the present invention for producing an adsorbent sheet provides a porous adsorbent, provides a sheet-like breathable substrate having a plurality of openings from one main surface to the other main surface, and a binder To bond the porous adsorbent material to the sheet-like breathable substrate. In a preferred embodiment, the porous adsorbent is obtained by supporting a chemical adsorbent on a porous carrier.

  In addition, another method of the present invention for producing an adsorbent sheet includes providing a porous adsorbent, providing a sheet-like breathable substrate, and converting the porous adsorbent into a sheet-like breathable substrate by using a binder. And forming a plurality of openings from one main surface to the other main surface in the sheet-like breathable substrate to which the porous adsorbent is bonded. In a preferred embodiment, the porous adsorbent is obtained by supporting a chemical adsorbent on a porous carrier.

  Regarding the sheet-like breathable substrate, the porous carrier, the chemical adsorbent and the like in these methods of the present invention, the above description regarding the adsorption sheet of the present invention can be referred to.

  FIG. 3 shows an example of a preferred method for producing the adsorption sheet of the present invention. Here, a chemical carrier obtained by dissolving a chemical adsorbent in water or other solvent is impregnated with a porous carrier, and the chemical adsorbent is attached to the porous carrier, thereby obtaining a porous adsorbent. Yes. Then, a binder is added to the slurry containing the porous adsorbent thus obtained and stirred for a predetermined time to obtain a slurry containing the porous adsorbent and the binder.

  By coating the substrate with the slurry thus obtained and drying it, the porous adsorbent is bonded to the sheet-like breathable substrate via a binder. The coating can be performed, for example, by applying the slurry to a substrate. The opening of the sheet-like breathable substrate may be provided before the porous adsorbent is held, or may be provided after the porous adsorbent is held.

  The slurry containing the porous adsorbent and the like can further contain a thickener. Such a thickener is particularly preferable when it is difficult to always stir the slurry during coating, or when the slurry separates into an emulsion containing water or a resin component and a porous adsorbent. .

  Examples of such a thickener include sodium polyacrylate, acrylic copolymer, polyacrylic acid, carboxylic acid copolymer (ammonium salt), and carboxylic acid copolymer (for example, sodium carboxymethyl cellulose). Carboxylic acid-based copolymer sodium salt), crosslinked sodium polyacrylate, crosslinked acrylic polymer, crosslinked polyacrylic acid and the like. The addition amount of the thickener can be, for example, 0.1 to 10% by weight, 0.3 to 5% by weight, or 0.5 to 3% by weight with respect to the porous carrier, but is limited to this range. Not.

  The breathable substrate coated with the slurry can be dried for a predetermined time after coating. Since the azole compound and the hydrazide compound, which are preferable chemical adsorbents, are organic substances, this drying step is preferably performed under drying conditions in which the chemical adsorbent is not thermally deteriorated. For example, this drying step can be performed at 150 ° C. or lower, 110 ° C. or lower, or 80 ° C. or lower.

"Air cleaner"
The air purifier of the present invention is an air purifier using the adsorbing sheet of the present invention as a filter, for example, a home or business air purifier, an in-vehicle air purifier mounted in a passenger compartment of an automobile, that is, a cabin filter. It is. Such an air purifier includes, in addition to the suction sheet of the present invention used as a filter, a fan for circulating the gas to be processed through the suction sheet, an inlet for sucking the gas to be processed, and a target through which the suction sheet has passed. It can have a blowout port for blowing out the processing gas, a housing housing these, and the like.

  The present invention will be described more specifically with reference to the following examples and comparative examples, but the present invention is not limited thereto.

1. Preparation of adsorption sheet (Example 1)
A chemical solution was prepared by adding 1 g (0.012 mol) of 4-amino-1,2,4-triazole as a chemical adsorbent to 200 g of water. Into this chemical solution, 100 g of coconut shell activated carbon (specific surface area 1000 m ² / g, median diameter (D50) 25 μm) as a porous carrier is added, stirred well, and a chemical adsorbent is supported on coconut shell activated carbon as the porous carrier. To obtain a porous adsorbent. In the slurry containing the porous adsorbent thus obtained, 131 g of a 2% solution of sodium carboxymethyl cellulose (manufactured by Nacalai Tesque) as a thickener and 74 g of an acrylic emulsion as a binder (bon coat AB-795 made by DIC) with a solid content of 57 %) And stirred for 30 minutes to prepare a slurry for supporting.

Opening 272 3mmφ punching holes (area 7mm ² ) at equal intervals in foamed polyurethane (Bridgestone, trade name HR-50) with a thickness of 10mm and a basis weight of 300g / m ² as a sheet-like breathable substrate This was coated with a supporting slurry and dried at 100 ° C. for 5 hours to produce the adsorption sheet of Example 1.

(Example 2)
An aperture adsorbing sheet of Example 2 was produced in the same manner as in Example 1 except that 578 3 mmφ punching holes were formed at equal intervals.

(Example 3)
Adsorption of Example 3 in the same manner as in Example 1 except that foamed polyurethane (Bridgestone, trade name HR-20) having a thickness of 10 mm and a basis weight of 150 g / m ² was used as the sheet-like breathable substrate. A sheet was produced.

Example 4
Except for using foamed polyurethane (Bridgestone, trade name HR-20) having a thickness of 10 mm and a basis weight of 150 g / m ² as a sheet-like breathable base material, and increasing the amount of slurry used for supporting. The adsorption sheet of Example 4 was produced in the same manner as Example 1.

(Example 5)
As a sheet-like breathable base material, ^two foamed polyurethanes (Bridgestone Corporation, trade name HR-20) having a thickness of 10 mm and a basis weight of 150 g / m ² are superposed, and a base having a thickness of 20 mm and a basis weight of 300 g / m ² is actually obtained. An adsorption sheet of Example 5 was produced in the same manner as Example 1 except that it was used as a material.

(Example 6)
As a sheet-like breathable base material, a foamed polyurethane (Bridgestone, trade name HR-20) having a thickness of 10 mm and a basis weight of 150 g / m ² was used as one sheet, and 3 mmφ holes were equally spaced by a heated metal needle. A suction sheet of Example 6 was produced in the same manner as Example 1 except that 272 were opened.

(Example 7)
As a sheet-like breathable substrate, a foamed polyurethane (Bridgestone, trade name HR-20) having a thickness of 10 mm and a basis weight of 150 g / m ² was used alone, and localized at the center of the sheet-like breathable substrate. In the same manner as in Example 1 except that 272 3 mmφ punching holes were opened, an adsorption sheet of Example 7 was produced.

(Example 8)
A foamed polyurethane (Bridgestone, trade name HR-20) having a thickness of 10 mm and a basis weight of 150 g / m ² was used as a sheet-like breathable substrate, and 4-amino-1,2,4 as a chemical adsorbent. -An adsorption sheet of Example 8 was produced in the same manner as in Example 1 except that triazole was not used.

(Comparative Example 1)
An adsorption sheet of Comparative Example 1 was produced in the same manner as in Example 1 except that no opening was formed.

(Comparative Example 2)
An adsorption sheet of Comparative Example 2 was produced in the same manner as in Example 1 except that no opening was formed and the amount of supporting slurry used was reduced.

(Comparative Example 3)
Example 1 except that a foamed polyurethane (Bridgestone, trade name HR-20) having a thickness of 10 mm and a basis weight of 150 g / m ² was used as the sheet-like breathable base material, and no opening was formed. In the same manner as described above, an adsorption sheet of Comparative Example 3 was produced.

(Comparative Example 4)
Use of foamed polyurethane (Bridgestone, trade name HR-20) having a thickness of 10 mm and a basis weight of 150 g / m ² as the sheet-like breathable base material, the opening was not formed, and the use of the supporting slurry An adsorption sheet of Comparative Example 4 was produced in the same manner as in Example 1 except that the amount was increased.

(Comparative Example 5)
Except that foamed polyurethane (Bridgestone, trade name HR-20) having a thickness of 10 mm and a basis weight of 150 g / m ² was used as a sheet-like breathable base material, and that activated carbon as a physical adsorbent was not used. In the same manner as in Example 1, a suction sheet of Comparative Example 5 was produced.

(Comparative Example 6)
Use of foamed polyurethane (Bridgestone, trade name HR-20) having a thickness of 10 mm and a basis weight of 150 g / m ² as a sheet-like breathable base material, no adsorbent was used, and an opening was formed A suction sheet of Comparative Example 6 was produced in the same manner as in Example 1 except that this was not done.

(Comparative Example 7)
As a sheet-like breathable substrate, a foamed polyurethane (Bridgestone, trade name HR-20) having a thickness of 10 mm and a basis weight of 150 g / m ² was used, an opening was not formed, and a chemical adsorbent was used. An adsorption sheet of Comparative Example 7 was produced in the same manner as in Example 1 except that 4-amino-1,2,4-triazole was not used.

(Comparative Example 8)
As a sheet-like breathable substrate, a foamed polyurethane (Bridgestone, trade name HR-20) having a thickness of 10 mm and a basis weight of 150 g / m ² was used, an opening was not formed, and a physical adsorbent was used. An adsorption sheet of Comparative Example 8 was produced in the same manner as in Example 1 except that activated carbon was not used.

2. Performance Evaluation Table 1 summarizes the characteristics of the adsorption sheets of Examples 1 to 7 and Comparative Examples 1 to 9 obtained as described above, the outline of the production method, and the aldehyde adsorption performance. In addition, about the pressure loss and the aldehyde adsorption | suction performance, it calculated | required as mentioned above.

  FIG. 4 shows the relationship between the amount of activated carbon retained in Examples 3 and 4 and Comparative Examples 2 to 4 and Comparative Example 6 and the pressure loss. When FIG. 4 is seen, when there is no opening part, when activated carbon retention amount is increased, pressure loss will increase drastically, and when it has an opening part, even if activated carbon retention amount is high, it turns out that pressure loss hardly changes. .

  FIG. 5 shows a comparison between the amount of activated carbon retained and the adsorption performance in Examples 3 and 4 and Comparative Examples 2 to 4. When FIG. 5 is referred, it turns out that adsorption | suction performance increases by increasing activated carbon holding amount, but the difference has come out in adsorption | suction performance by the presence or absence of an opening part. This result can also be confirmed by comparison between Example 1 and Comparative Example 1, and the sheet-like adsorbent has not only the pressure loss significantly reduced but also the adsorption performance is higher due to the opening portion. It has become.

  When Example 1 and Example 2 are compared, it can be seen that the pressure loss is greatly reduced while maintaining the adsorption performance equal to or higher due to the high surface area ratio. Furthermore, when Example 1 and Example 4 are compared, by reducing the basis weight of the base material, even if it contains a large amount of adsorbent, the pressure loss can be greatly reduced, and the adsorption performance is also improved. You can see that

  Comparing Example 4 and Example 5, it can be seen that the adsorption performance can be improved by increasing the thickness of the sheet-like adsorbent. Moreover, when Example 4 and Example 6 are compared, it turns out that the adsorption | suction performance improves the sheet-like adsorbent perforated by punching rather than the sheet-like adsorbent perforated by heating. Furthermore, when Example 4 is compared with Example 8, it turns out that adsorption | suction performance improves because the porous adsorbent carries the chemical adsorbent.

  When Example 4 and Example 7 are compared with each other, they have almost the same performance, and it can be seen that the position of the opening does not have a great influence on the adsorption performance.

  When Example 8 which does not use a chemical adsorbent is compared with Comparative Example 7, the adsorption performance of Example 8 having openings in the sheet-like adsorbent remains only slightly higher. This is a different result from the comparison between Examples 1 and 4 and Comparative Examples 1 and 4. In the present invention, the porous adsorbent carries a chemical adsorbent and the sheet adsorbent. It can be seen that the provision of the apertures in this has a synergistic effect.

DESCRIPTION OF SYMBOLS 1 Adsorption sheet 2 Sheet-like breathable base material containing porous adsorbent 3 Multiple openings 4 Air purifier 5 Stirring fan 6 Gas to be treated

Claims (14)

An adsorbent sheet having a sheet-like breathable substrate, a porous adsorbent, and a binder that binds the porous adsorbent to the sheet-like breathable substrate,
The sheet-like breathable base material has a plurality of openings from one main surface to the other main surface.
Adsorption sheet.   The adsorbent sheet according to claim 1, wherein the porous adsorbent comprises a porous carrier carrying a chemical adsorbent.   The adsorption sheet according to claim 2, wherein the porous carrier is selected from the group consisting of activated carbon, sepiolite, palygorskite, zeolite, activated carbon fiber, activated alumina, sepiolite mixed paper, silica gel, activated clay, permiculite, and diatomaceous earth. .   The adsorption sheet according to claim 2 or 3, wherein the chemical adsorbent is selected from the group consisting of an azole compound, a hydrazide compound, and a combination thereof. The area per the one opening 1 on one surface of the sheet-like breathable substrate is a 1 mm ² to 20 mm ^2, the adsorption sheet according to any one of claims 1-4.   The adsorption sheet according to any one of claims 1 to 5, wherein a surface area ratio by the plurality of openings is in a range of 1.0 to 50%. The holding amount of the porous adsorbent, the sheet-like breathable base material 1 cm ³ per is 0.03 g / cm ³ or more, the adsorption sheet according to any one of claims 1 to 6.   The difference between the pressure loss when there is no opening and the pressure loss when there are the plurality of openings is 0.20 mmAq or more with respect to a wind speed of 0.42 m / s. The adsorption sheet according to claim 1.   The adsorption sheet according to any one of claims 1 to 8, wherein the plurality of openings are provided by mechanical means.   The sheet-like breathable substrate is selected from the group consisting of a foamed resin, a net-like resin, a porous resin film, a knitted fabric, a woven fabric, a nonwoven fabric, paper, and inorganic fibers. Adsorption sheet as described in 1.   11. The binder of claim 1-10, wherein the binder is selected from the group consisting of acrylic resins, acrylic-styrene resins, acrylic-silicon resins, acrylic-urethane resins, vinyl acetate-acrylic resins, polysiloxane-acrylic resins, and butadiene resins. The adsorption sheet as described in any one of Claims.   The air cleaner which uses the adsorption sheet as described in any one of Claims 1-11 as a filter. Providing a porous adsorbent,
Providing a sheet-like breathable substrate having a plurality of openings from one main surface toward the other main surface; and binding the porous adsorbent to the sheet-like breathable substrate with a binder; The manufacturing method of the adsorption sheet containing this. Providing a porous adsorbent,
Providing a sheet-like breathable substrate;
The porous adsorbent is bonded to the sheet-like breathable substrate by a binder, and the sheet-shaped breathable substrate to which the porous adsorbent is bonded is changed from one main surface to the other main surface. The manufacturing method of an adsorption sheet including forming the some opening part which goes to.

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